Archaea, Prokarya, and Eukarya). The replicase (Rep) from these viruses is responsible for initiating rolling circle replication (RCR) of their genomes. Rep is a multifunctional enzyme responsible for nicking and ligating ssDNA and unwinding double-stranded DNA (dsDNA). We report the structure of porcine circovirus 2 (PCV2) Rep bound to ADP and single-stranded DNA (ssDNA), and Rep bound to ADP and double-stranded DNA (dsDNA). The structures demonstrate Rep to be a member of the superfamily 3 (SF3) of ATPases Associated with diverse cellular Activities (AAA+) superfamily clade 4. At the Rep N terminus is an endonuclease domain (ED) that is responsible for ssDNA nicking and ligation, in the center of Rep is an oligomerization domain (OD) responsible for hexamerization, and at the C terminus is an ATPase domain (AD) responsible for ssDNA/dsDNA interaction and translocation. The Rep AD binds to DNA such that the ED faces the replication fork. The six AD spiral around the DNA to interact with the backbone phosphates from four consecutive nucleotides. Three of the six AD are able to sense the backbone phosphates from the second strand of dsDNA. Heterogeneous classification of the data demonstrates the ED and AD to be mobile. Furthermore, we demonstrate that Rep exhibits basal nucleoside triphosphatase (NTPase) activity.Circular Rep-encoding single-stranded DNA (CRESS-DNA) viruses infect members from all three domains of life ( Archaea, Eubacteria, and Eukarya domains of life (–9–ori) to unwind the genome and generate a cruciform structure—a process that is possibly accompanied with ATP hydrolysis by Rep. Rep nicks the (+) strand of the cruciform at a sequence-specific site to generate a free 3′-OH end for leading-strand DNA synthesis, and itself becomes covalently attached to the 5′-PO4 of the (+) strand. Replication continues to generate a complete (+) strand with several nucleotides beyond the start site. A second round of cleavage by Rep liberates the 3′-OH of the same strand. Rep then ligates the ssDNA 5′-PO4 attached to itself to the recently generated 3′-OH of the same strand to generate a circular ssDNA (Circular replicase (Rep)-encoding single-stranded DNA (CRESS-DNA) viruses are a diverse and widely prevalent group of viruses that infect  of life –6. CRESSof life –, 8. Rep of life –. RCR is of life –, 9–17. W life –9–. CRESS-DED) , and ED from transposases suggests that these domains are evolutionarily related  superfamily (clade 4). The structures further demonstrate the ED to be mobile, Rep to form a hexamer with ss/dsDNA bound to its central channel, Rep to use an oligomerization domain (OD) for hexamerization, and the Rep’s ATPase domains (AD) to adopt a spiral staircase arrangement around ssDNA/dsDNA and demonstrate a sequential mode of ATP hydrolysis and direction of ssDNA translocation. We further demonstrate that Rep exhibits basal nucleoside triphosphatase (NTPase) activity.The nuclear magnetic resonance (NMR) and crystal structure of an N-terminal fragment of Rep identify this domain to be an HUH (His-hydrophobic-His motif) endonuclease domain (ED) , 19. ED  related , 20–22. s genera . Geneticentified . Members animals , 25. Porindustry –28. To uCryo-EM two-dimensional (2D) class averages identify top, tilted, and side views of Rep in ice . Top andAD may adopt distinct positions with respect to the OD . We. WeAD mao the OD  30). Th. ThAD mareported , 19. 3D reported . The amireported  to C. Th10.1128/mBio.00763-21.1FIG S1FIG S1, TIF file, 2.7 MB.Cryo-EM studies of PCV2 Rep. (A) Representative micrograph of collected data identifying different orientations of Rep. The image has been low pass filtered to 15-Å resolution to enhance the contrast. Scale bar at bottom left is 20 nm. (B) Fourier shell correlation curves reported by cryoSPARC. (C) Resolution heat maps of PCV2 Rep bound to ssDNA (top) and dsDNA (bottom). Multiple slices of the side view demonstrate the local resolution of the maps. Note that both the ssDNA and dsDNA have lower resolution than the protein. Scale bar on left identifies the resolution corresponding to the heat map. Download Copyright © 2021 Tarasova et al.2021Tarasova et al.https://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International license.This content is distributed under the terms of the 10.1128/mBio.00763-21.2FIG S2ED (pastel yellow), OD (pastel red), and AD (pastel cyan). The secondary structures of the ED crystal structure (PDB entry 5XOR), OD, and AD (this report) are shown inside the domain boxes. Absolutely conserved amino acids are white font in a red box with blue outline. Highly conserved amino acids are red font in a white box with blue outline. Amino acids absent in a sequence are indicated by periods. The black circles identify amino acids with large side chains  that were used for eliminating possible register errors due to the moderate resolution of the map. Download FIG S2, TIF file, 1.4 MB.Sequence alignment of circovirus Reps. Sequence alignment generated by Clustal Omega. Image generated using ESPript 3.0 with the % equivalent and normal coloring scheme. Boxes at the top identify Copyright © 2021 Tarasova et al.2021Tarasova et al.https://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International license.This content is distributed under the terms of the 10.1128/mBio.00763-21.3FIG S3ED. The ED, OD, and AD are colored as according to ED in the data. The low number of particles in each class did not allow for a high-resolution map to be determined. Download FIG S3, TIF file, 0.8 MB.3D variability analysis of the Copyright © 2021 Tarasova et al.2021Tarasova et al.https://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International license.This content is distributed under the terms of the OD (amino acids 119 to 157) and an AD (amino acids 158 to 301). The OD is a four-helix bundle with three of the helices nearly parallel to one another and the fourth perpendicular to them. Six OD oligomerize to generate a torus with a pore diameter of 12 Å. The pore is defined by the side chains of Arg145, Asn146, Tyr147, and Arg148. Segmentation of density pertaining to the OD hexamer followed by 60, 120, 180, 240, and 300° rotations through the center of the pore overlays onto the original density with correlation coefficient values between 0.95 and 1.0, suggesting that the OD hexamer follows C6 symmetry. Sequence comparison suggests that all circovirus Reps share a minimum of 30% sequence identity in this region; thus, it is likely that all circovirus Reps utilize a comparable OD for forming hexamers , the simian virus 40 (SV40) large T antigen , adeno-associated virus 2 (AAV2) Rep40 (PDB entry 1S9H), and bovine papillomavirus (BPV) E1 (PDB entry 2GXA), all members of SF3 from the AAA+ superfamily , 33OD isAD overlay with root mean square deviation (RMSD) values in the range of 0.7 to 1.1 Å. The arrangement of AD can be described by six rotation axes about which a rotation followed by a translation, parallel to the axis, will overlay two neighboring ADs (AD-AD interfaces. Between each of five neighboring AD (subunits A to E), there is 760 Å2 of buried surface area (BSA). An extensive seam between the subunits F and A diminishes their AD interaction to 80 Å2 of BSA , and sensor 3. Density not described by the Rep coordinates can be observed within four of the putative ATP binding sites (2+ for two reasons: (i) ATP-Mg2+ was added during purification, and (ii) Rep is an ATPase (see below) and likely to have hydrolyzed the ATP present in the buffer. Into each of the four densities could be modeled a Mg2+, two phosphates, and the ribose sugar of ADP  and the ADP β-phosphate, an H-bond between the Lys180 (WA) amine and ADP β-phosphate, electrostatic interaction between the Asp216 carboxylate (WB) and Mg2+, and electrostatic interaction between Mg2+ and the ADP phosphates. Also, the Asn256 (mC) amide is in proximity to position a water for nucleophilic attack on the ATP γ-phosphate  H-hosphate , and (iihosphate . In tota10.1128/mBio.00763-21.4FIG S4cis-subunit in yellow and trans-subunit in red. (Bottom) LigPlot+ images of Rep-ADP interaction. Residues involve in hydrophobic contacts are depicted as arcs with emanating lines, and hydrogen bonds are depicted as dashed lines. (A) Subunit interface AB; (B) subunit interface BC; (C) subunit interface CD; (D) subunit interface DE; (E) ATP state of SV40 LTag; (F) ADP state of SV40 LTag; (G) ATP-like state of BPV E1; (H) ADP state of BPV E1. The Mg2+ are shown as magenta spheres, and the Cl−1 of BPV E1 is shown as a larger pink sphere. Download FIG S4, TIF file, 1.2 MB.Nucleotide binding states of Rep. (A to D) (Top) Licorice models with the Copyright © 2021 Tarasova et al.2021Tarasova et al.https://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International license.This content is distributed under the terms of the cis-components (1SVM) and ADP-bound E1 (PDB entry 2GXA) structures. The Arg498 of LTag coordinates a water molecule to the ATP γ-phosphate and is proposed to act as a switch in sensing ATP binding and coordinating its hydrolysis to the neighboring subunit  and BPV E1 by overlaying subunits providing the mponents . LTag anmponents , 34. The EV71 2C .10.1128/mBio.00763-21.5FIG S51SVM); (B) EV71 2C bound to ATP-γ-S (5GRB); (C) AAV2 Rep40 bound to ADP (1U0J); (D) BPV E1 bound to ADP (2GXA); (E) PCV2 Rep bound to ADP (this report). The N and C termini are indicated by blue and red circles. Download FIG S5, TIF file, 1.1 MB.The lid-like domains of SF3 helicases. Cartoon ribbon model of the ATPase domains in red, C-terminal extension (lid-like domain) in yellow, and nucleotide in CPK. (A) SV40 LTag bound to ADP . Th. Th2+, t weak  is a generalized interpretation of the multiple ssDNA sequences bound to Rep.Density can be seen in the center of the Rep hexamer spiraling away from the OD . BiochemOD . We hypoOD . Indeed,OD , suggestOD  and manuOD . The docOD , 40. TheOD . The mod−1). Density for the ssDNA extends toward the center of the OD ring and terminates near the guanidium group of Arg148, suggesting that ssDNA is translocated through the pore. Rigid body fitting of a purine nucleotide into the pore suggests that its translocation requires either the dehydration of the nucleotide, rotation of the base, or expansion of the pore. The phosphates from ssDNA interact with amino acids located in two loops: pore loop 1 located between β2 and α2 (Trp202) and pore loop 2  located between α3 and β4 (Lys240 and Gly241) (The backbone phosphates from four consecutive nucleotides interact with the six subunits of Rep (1 nt subunit Gly241) . The ssDOD pore. The 5′ overhang agrees with the 3′-to-5′ directionality of Rep. In addition to the described interactions between Rep and the ssDNA, the guanidinium groups of Arg199 (pore loop 1) from subunits A to C are less than 7.5 Å from the first four nucleotide phosphates of the second strand of nucleic acid  Cryo-EM map with modeled regions colored in dark gray. (Center) Map shown as a chicken wire mesh with model as stick representation. (Right) Ninety-degree rotation of center orientation; arrow identifies direction of rotation. The dsDNA map (second from top) is low pass filtered to demonstrate the fit of the double helix. This region has a much lower resolution than the protein; see Copyright © 2021 Tarasova et al.2021Tarasova et al.https://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International license.This content is distributed under the terms of the ED in complex with a 10-mer ssDNA derived from the viral ori provides the first image of how ED binds to the loop of the predicted ori stem-loop hairpin for the nicking activity described above  an OD in the middle of the sequence, and (iii) an SF3 AD at the C terminus , and Rep with no DNA affects this property. Six ODs assemble to form a torus with a pore defined by a 12-Å diameter. The AD structure is homologous to the ATPase domains of SV40 LTag, the BPV E1, the AAV2 Rep40, and the EV71 2C helicase proteins.CRESS-DNA viruses are widely distributed in nature and utilize RCR for genome replication , 6. Whiled above . To proved above . The strterminus . The denin vivo conditions. Rep binds ssDNA in a 3′-to-5′ direction, such that the Rep N terminus is positioned near the dsDNA fork and ssDNA is pulled through the OD pore . ATP anabolism is the reverse of this process. The sequential model was adopted to describe the translocation of nucleic acid by the homohexameric T7 gp4 and Rho  the nucleotide states for the six ADs from the top to bottom of the staircase are ATP, ATP, ATP/ADP, ATP/ADP, ADP/empty, empty; (iii) only the central four ADs engage the substrate; (iv) the AD at the bottom of the staircase translocates to the top of the staircase upon binding ATP; (v) hydrolysis of ATP for the AD closest to the bottom of the staircase drives the remaining ADs to translocate toward the bottom of the staircase and pull the substrate; and (vi) ADP is released from the AD that is nearest to the bottom of the staircase. Consequently, each ATP binding and hydrolysis translocate the substrate one unit through the central channel of the translocase (Plasmodium translocon of exported proteins (PTEX), a 1.6-MDa complex that transports Plasmodium proteins into the host erythrocytes across the Plasmodium membrane  was codon optimized by GenScript (New Jersey) and cloned into a modified pET28a vector containing a small ubiquitin modifier (SUMO) following the start codon for expression in Escherichia coli BL21(DE3) cells. Cells were grown in terrific broth in the presence of 50 μg ml−1 kanamycin until mid-log phase and cooled to 20°C, protein expression was induced with 200 μM isopropyl-β-d-1-thigalactopyranoside (IPTG), and protein was expressed for less than 16 h at 20°C. Cells were centrifuged at 4,000 × g for 30 min. Cell pellet was resuspended in 35 ml of 20 mM HEPES (pH 8.2), 450 mM sodium chloride (NaCl), 25 mM imidazole (pH 8.2), 10 mM magnesium chloride (MgCl2), 0.5 mM Tris(2-carboxyethyl)phosphine hydrochloride (TCEP), 100 mM phenylmethylsulfonyl fluoride (PMSF), 0.5 μl salt-activated nuclease (Millipore Sigma), 1 mM ATP (Millipore Sigma) and lysed using a sonicator. The lysate was centrifuged at 32,000 × g for 40 min at 4°C. The supernatant was applied to 5 ml of Ni-NTA (nitrilotriacetic acid) chromatography resin (Gold Biotechnology), washed with 5 column volumes (CV) using the same buffer, eluted, and fractionated with 5 CV of the same buffer supplemented with 600 mM NaCl and 750 mM imidazole (pH 8.2). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis  was used to visualize the protein content of the fraction. Fractions with the greatest Rep content were pooled and digested with 100 μg of Ulp1 protease for 1 h at 4°C to hydrolyze the SUMO fusion at the N terminus, diluted to 300 mM NaCl using the same buffer, and processed using a 1-ml heparin-conjugated chromatography resin  connected to an Äkta Pure . Sample was washed with 3 CV of the same buffer and eluted using a salt gradient (0 to 2 M NaCl) in the same buffer. Fractions possessing Rep were concentrated using ultrafiltration and processed using size exclusion chromatography (Superose 6 10/300) connected to an Äkta Pure equilibrated in 20 mM HEPES (pH 8.2), 500 mM NaCl, 0.2 mM TCEP, 10 mM MgCl2 . Fractions possessing Rep were pooled, concentrated, flash frozen using N2(l), and stored at −80°C. Ulp1 was purified as previously described  was determined by comparing its band intensity to that of carbonic anhydrase  with known concentration.−1 (AU time−1) rate of NADH conversion to NAD+. AU was converted to concentration using a calibration curve of NADH concentration (known) versus absorbance (measured). Kinetic parameters (kcat and S0.5) were extracted using nonlinear fitting with the program Origin 2016 (OriginLab).The ATP/NADH-coupled spectrophotometric assay was performed using 66 nM Rep per reaction . Measure−1 (4 μl) were applied to the grids for 3 s; blotted using a blot force of 2, a blot time of 4 s, a drain time of 0 s, a relative humidity of 100%, and a temperature of 4°C; and plunge frozen into a bath of liquid ethane using an FEI Mark IV Vitrobot. Data were collected on a Thermo Fisher Scientific FEI Titan Krios operating at an acceleration voltage of 300 kV and a Cs  of 2.7 nm. Images were recorded with a Gatan Summit K2 direct electron detector operating in counting mode (Grids for cryo-EM were prepared by plasma cleaning UltrAuFoil Holey Gold films (Electron Microscopy Sciences) for 30 s using a Fischione Instruments model 1070 NanoClean. Samples at 0.4 mg mling mode . The micing mode .Ab initio structure determination, heterogeneous classification, 3D variability, nonuniform refinement, and 3D Fourier shell correlation (3DFSC) were performed with cryoSPARC to generate Rep bound to ssDNA and dsDNA , B-DNA , C-DNA , and RNA  were generated by the x3DNA server . These mMap segmentation was performed using UCSF Chimera with a 2.5-Å-radius color zone. Correlation coefficient values between maps were also calculated using UCSF Chimera .2, 1 mM CaCl2, and 50 mM EDTA for 2 h. A 1% agarose gel (40 ml) was cast in the presence of 1 μl of SYBR-Gold nucleic acid stain . For controls, a 1 μM concentration of a 12- and a 44-nt oligonucleotide (10 μl each) was also processed with the agarose gel. Gels were visualized using a UV-transilluminator at 302 nm.To determine the identity of nucleic acid bound to Rep, we independently treated the purified sample with DNase I or RNase I (Thermo Fisher) according to the manufacturer’s protocol. For each reaction, a total of 40 μM purified Rep (10 μl) was first denatured at 90°C for 15 min. The sample was cooled to room temperature and then digested with 10 U of RNase I in 20 mM Tris-acetate (pH 8.0), 100 mM NaCl, and 0.1 mM EDTA or with 1 U of DNase I in 100 mM Tris-HCl (pH 7.5), 25 mM MgCl7LAR, and Rep with dsDNA, 23250/7LAS, respectively.The cryo-EM map and atomic coordinates have been deposited into the EMDB and PDB, respectively. Accession codes (EMDB/PDB) are as follows: Rep with ssDNA, 23249/


Composite cylinders were cemented on the zirconia sample with Duo-Link Universal (Bisco). Eight specimens per group were subjected to 10,000 thermocycles and subsequently bond strength was tested with shear-bond strength test. ANOVA test showed that artificial aging significantly affected the bond strength to zirconia. Bonferroni test highlighted a significant influence of adhesive treatment (Signum) on bond strength after thermocycling. It was concluded that 10-MDP-based bonding systems showed no improvement in initial bond strength compared with tribochemical treatment. All chemical bonding techniques tested in this study were influenced by thermocycling.This study evaluated the effectiveness of chemical-based adhesive techniques on promoting immediate and aged bond strength between zirconia and luting cement. A total of 128 discs of zirconia were divided into 4 groups ( Continued development of dental ceramics has allowed the coupling of excellent esthetic qualities with improved mechanical properties, and these ceramics are now widely used to realize indirect metal-free restorations. Their major properties are hardness, a high coefficient of elasticity, resistance to heat and chemical attack, and high fragility ,2,3. Sev2), which include feldspathic, leucite-based, and lithium-disilicate materials, have well-established adhesive protocols due to the presence of silica. In contrast, alumina and zirconia, also called crystalline ceramics, do not contain silica or glass components. Their atoms are arranged in a regular pattern, which makes them denser and more resistant to fracture [Dental ceramics could be classified according to the silica content. The silica-based ceramics  monomer. The 10-MDP monomer has two functional groups, an acid group that bonds to hydroxyl groups on the zirconia surface and a methacrylate (carboxylic acid group) that can be light-cured with the composite monomers. The 10-MDP monomer is contained in specific primers designed for zirconia , but recn = 16 each), where the specimens were randomly allocated  considering:This study was designed in 8 study groups : tribochemical treatment, Signum Zirconia Bond ; Z-Prime Plus ; All-Bond Universal .“Artificial aging” in 2 levels: half of the specimens treated with an adhesive approach were thermocycled before shear-bond stress.A schematic representation of the study design is displayed in For this in vitro study, 128 square-shaped specimens 2 mm thick were prepared by sectioning CAD-CAM blocks of cubic zirconia with a diamond saw . After sectioning, all specimens were sintered and glazed according to the manufacturer instructions. The obtained slices were polished with #600, #1000 and #1200 paper grit to standardize zirconia surface.n = 32 per group) according to the adhesive treatment performed. Before adhesive application, all the ceramic surfaces were cleaned and dried.The so-obtained specimens were embedded in an acrylic resin base , repolished with paper grit to remove any residual resin that might have covered the zirconia surface. Specimens were the washed under copious deionized water and divided into 4 groups  at 3 bar pressure for 15 s at 10 mm distance using an intraoral microblasting unit (Kavo). After washing the specimen surface for 30 s with water, one coat of Silane Primer (3M ESPE) was applied and air-dried for 10 s before brushing the bonding resin  over the entire surface and light-cured for 20 s with a LED curing unit at 1400 mW/cmGroup 2: Signum Zirconia Bond I  was dispensed and applied with a microbrush to the entire surface for 20 s and air-dried for five seconds; Signum Zirconia Bond II was then applied, and light-cured as described in group 1.Group 3: The ceramic surface was coated with a single layer of Z-Prime Plus , which was applied through a microbrush for 1 min and gently air-dried.Group 4: A universal adhesive system  was brushed over the zirconia surface in two consecutive layers, 15 s each. After gentle air-drying, specimens were light-cured as described in group 1.A summary of the adhesives procedures in the different groups is displayed in 2 for 120 s. Then, the polyethylene mold was removed, and the cylinders were transferred to distilled water and stored in a dark box for 7 days at 37 °C. Then, after the various adhesive procedures were performed on the zirconia surfaces, the cylinders were cemented with a constant pressure on the center of the zirconia sample surface with Duo-Link Universal (Bisco), and light-cured after one minute on four sides for 20 s per side.Preformed polyethylene molds with a hole in the center were then used to produce composite cylinders . The nanohybrid composite resin  was placed into the mold and incrementally condensed to fill it; each cylinder was cured with a multi-LED lamp  at 1400 mW/cm2, which is calculated using the formula σ = L/A, where L is the force (expressed in N) at which there was the detachment of the cylinder, A = π × r2 (in mm2) was the bonding surface, and r is the radius of the cylinder.Next, the specimens were stored in deionized water for 24 h at 37 °C. After storage 16 specimens from each group were immediately subjected to the shear-bond strength test, while the remaining 16 specimens of each group were subjected to 10,000 thermal cycles in alternating water baths at 5 °C and 55 °C for 60 s each (5 s dwell time). The shear-bond test was performed fixing the resin base on a universal machine  with a notched blade that applied a force on the composite cylinder at a speed of 1 mm/min. This test provides bond strength expressed in MPa/mmFractured specimens were observed under optical microscopy  at 40× magnification to establish failure modes, which were classified as: ACO (adhesive detachment between composite and resin cement); ACE (adhesive detachment between ceramic and resin cement); AM (mixed adhesive detachment); CC (cohesive detachment within composite) and CM (cohesive detachment within ceramic).post hoc tests were performed to evaluate the effect of different adhesion technique (AT) and artificial aging (AA), and their interaction, on bond strength. Fracture modality was analyzed using the χ2 test. Differences were considered statistically significant at p < 0.05.Two-way ANOVA and Tukey Mean bond strengths (with standard deviations) and type of fracture (expressed as percentage) in each group before and after thermocycling are shown in p < 0.00001) and the artificial aging (p < 0.0001) significantly affected the bond strength on zirconia. The Tukey analysis highlighted a significant influence of adhesive treatment on bond strength after thermocycling. In particular, the bond strength obtained in group 2 was significantly higher than that for other adhesive procedures (p < 0.0001). In regard of the fracture mode, ACO was the mainly detected fracture in all groups, before and after thermocycling. The χ2 test revealed that AT and AA did not statistically influence the type of fracture between zirconia and dual-curing cement.The ANOVA test showed that adhesive treatment  with the hydroxyl groups on the zirconia surface. A recent in vitro study  confirmeRegarding the effectiveness of chemical bonding techniques, the results of the present study are consistent with those reported by Seabra et al. , who con2O3 particles, followed by silane application. The tribochemical treatment allows combining micro-mechanical retention created by sandblasting with the chemical retention achieved by silanization. In the present study, the tribochemical treatment did not increase the immediate bond strength of the resin cement to zirconia compared with ceramic primers and universal adhesives, and it was more susceptible to damage by thermocycling then some chemical bonding treatments. Several previous studies investigated the bond strength obtained between a silanized zirconia surface and resin-based cement, but there is still no consensus in the literature. Passos et al. [The tribochemical treatment consists of surface roughening with 30-µm silica modified with Als et al.  evaluates et al.  claimed s et al. ,39, surfs et al. . Thus, tTo better assess the long-term effectiveness of the adhesive treatments, samples were subjected to a thermocycling procedure entailing alternating baths of distilled water at 5 °C and 55 °C for 60 s each. In the present study, 10,000 thermal cycles were performed, after which some samples showed spontaneous debonding of the cylinders and they were consequently excluded from the study. Six cylinders had broken away: one from group 1, three from group 2, and two from group 4. Thermocycling is generally used to cause rapid aging of a composite; switching between high- and low-temperature baths produces expansion and contraction of the composite, which places stress on the adhesive interface, simulating the aging conditions of the mouth. Thus, thermocycling induces the hydrolytic degradation of the bonding because of the water diffusion into the interfacial layer of the resin composite and zirconia, decreasing the bond strength of resin luting agents to zirconia ,41,42. RThe results of the present study caused us to reject the second null hypothesis because thermocycling significantly influenced the bond strength for all adhesive techniques tested in this in vitro study. These results were partially supported by a previous study by Kim et al. , which eIn the present study the samples treated with specific primers for zirconia (Z-Prime Plus and Signum Zirconia Bond) showed similar bond strengths to other techniques. However, after thermocycling, Signum Zirconia Bond maintained significantly higher bond strength than other treatments. This outcome may be related to the primer composition. Signum Zirconia contained a mixture of organophosphate monomers that bind chemically to the zirconia on one side and to the composite resin on the other side. In particular, organophosphates monomers have an organofunctional component, often a methacrylate group, which can be co-polymerized with the monomers of the resin composite, and a phosphoric acid that binds with the metal oxides of zirconia. The other monomers cooperate in the development of the bond between the zirconia and resin cement. Moreover, the presence of acetone in Signum Zirconia Bond could increase the surface wettability of zirconia and thus promote bonding with methyl–methacrylate. Acetone can also remove impurities from the zirconia surface , thus inThe results obtained confirmed that there are currently adhesive strategies to be applied in the cementation of cubic zirconia. However, there is still a problem of stability of the adhesion values obtained, which prove to be susceptible to stresses such as thermocycling. Furthermore, the effect of the mechanical stresses on adhesion on zirconia should be evaluated in addition to thermal stress.Within the limitations of this in vitro study, it could be affirmed that all adhesive treatments tested showed significant reduction in the bond strength after thermocycling. Moreover, the use of specific zirconia primers such as Signum Zirconia Bond showed a significantly higher bond strength than that of other adhesive procedures after thermocycling. All-Bond Universal did not achieve any improvement in bond strength compared with tribochemical treatment or other specific primers.


Chitosan (CS)/poly(ethylene oxide) (PEO)-based nanofiber mats have attracted particular attention as advanced materials for medical and pharmaceutical applications. In the scope of present studies, solution blow spinning was applied to produce nanofibers from PEO and CS and physicochemical and biopharmaceutical studies were carried out to investigate their potential as wound nanomaterial for skin healing and regeneration. Additional coating with hydrophobic poly(dimethylsiloxane) was applied to favor removal of nanofibers from the wound surface. Unmodified nanofibers displayed highly porous structure with the presence of uniform, randomly aligned nanofibers, in contrast to coated materials in which almost all the free spaces were filled in with poly(dimethylsiloxane). Infrared spectroscopy indicated that solution blow technique did not influence the molecular nature of native polymers. Obtained nanofibers exhibited sufficient wound exudate absorbency, which appears beneficial to moisturize the wound bed during the healing process. Formulations displayed greater tensile strength as compared to commercial hydrofiber-like dressing materials comprised of carboxymethylcellulose sodium or calcium alginate, which points toward their protective function against mechanical stress. Coating with hydrophobic poly(dimethylsiloxane)  impacted porosity and decreased both mechanical properties and adherence to excised human skin, though the obtained values were comparable to those attained for commercial hydrofiber-like materials. In vitro cytotoxicity and irritancy studies showed biocompatibility and no skin irritant response of nanofibers in contact with a reconstituted three-dimensional human skin model, while scratch assay using human fibroblast cell line HDFa revealed the valuable potential of CS/PEO nanofibers to promote cell migration at an early stage of injury. Nanotechnology is a dynamically growing discipline with a large potential in the medical and pharmaceutical fields. Among a wide range of nanomaterials, including nanotubes, nanoparticles, and nanoflakes ,2, nanofElectrospinning has been the most widely explored method of polymer-based nanofibers preparation thus far . The proBasically, in SBS, a polymer solution is flown through the inner nozzle and stretched into fibers by a pressurized airflow, enabling their deposition on a collector in the direction of gas flow. It is a robust process with a relatively high production rate and low energy consumption which, in contrast to the electrospinning method, does not need the use of harsh organic solvents or high voltage .Among biopolymers used in spinning technologies, chitosan (CS) is a biocompatible polysaccharide composed of randomly ordered glucosamine and N-acetylglucosamine units linked with β (1 → 4) glycosidic bonds, and has attracted a particular attention . CS is cIt should be stated that CS is a relatively inhomogeneous material (particularly due to its origin and manufacturing process) and a wide range of CS types differing, e.g., in purity level, deacetylation degree, or molecular mass, are thus commercially available. These internal properties influence not only the final product characteristic or its applicability, but also may determine the suitability of a particular type of CS in a technological process. For instance, CS with higher molecular weight above 200–250 kDa) can be considered as a viscous agent for semi-solid preparations (including hydrogels or emulgels) 0–250 kDa, or micrPoly(ethylene oxide) (PEO) is a class of nonionic synthetic polymers also applied in spinning techniques solely or as additives to other polymers . PEO is To our best knowledge, there are only a limited number of studies focused on the use of CS in solution blow spinning ,30 and nw/w) polymer solutions (formulation CS/PEO 10%). Morphological properties of CS/PEO nanofibers were investigated by using scanning electron microscopy. Basically, SEM imaging  or 10%  compatibility, and the plausible effect of SBS process on the interaction between PEO and CS. ATR-FTIR spectra of unmodified CS/PEO nanofibers and poly(dimethylsiloxane) modified nanofibers CS/PEO-S with respect to pure PEO and CS are shown in −1 assigned to asymmetric stretching vibrations of -CH group and a prominent complex absorption intensity at around at 1050 and 1020 cm−1 attributed to C–O–C stretching mode  was purchased from Sigma and JC-1 MitoScreen kit was obtained from BD Biosciences . EpiDerm tissue (lot number 28690) was from MatTek In Vitro Life Science Laboratories . Simulant wound exudate fluid  for in vitro absorption capacity measurements and bioadhesive studies was prepared according to [Highly purified medical grade chitosan (Chitosciencerding to . Polyethrding to  with thew/w) CS and 6.4 and 8% (w/w) polyethylene oxide (PEO) were dissolved in 0.5% (v/v) acetic acid aqueous solution and left for continuous stirring for 24 h in room temperature. Overall concentration of polymers in the solution was 8 and 10% (w/w). Concentration below 8% had too low viscosity whereas concentration above 10% was found to clog nozzle during SBS process. According to [Suitable concentration and ratio of PEO and CS for the fiber formation process were selected upon preliminary studies. Solutions with blend of polymers containing 1.6 and 2% ) to 1.0 mL/h (10% (w/w)). At the same time, the airstream was supplied through the outer nozzle of the SBS nozzles system with a constant pressure of 0.08 MPa. Fibers were produced by shear-drag elongation of the polymers blend solution by the stream of air at the distance of 50 cm between the nozzle system and the surface of the collector. As a collector, the rotating cylinder with reciprocating motion was used . The process continued until the formation of a nanofibrous mat with a thickness of approximately 100–200 μm and was carried out three times for each nanofibrous material’s composition.Nanofibers were produced in SBS process, described in detail previously by our group . During For mechanical and bioadhesive measurements, nanofibrous materials were additionally coated with liquid poly(dimethylsiloxane) (S-coating) which was sprayed uniformly through a nozzle (diameter 0.8 mm) on their surface in a mass ratio 1:1. The distance between the nozzle and the nanofibers was 10 cm. The morphology and fiber size were investigated using scanning electron microscopy . Samples were prepared by cutting a mat into a 5 mm × 5 mm square sample and putting it on the surface of the SEM stub using carbon/aluminum conducting tape. Before imaging, samples were coated  with about 10 nm layer of Au:Pd (80:20 atomic ratio). For each sample at least 100 fibers were measured in three different areas of observation.s—sample density, dp—polymer density. Square samples with dimensions about 10 mm × 10 mm were weighed, and sample density was calculated: ds = m/(δ∙A), where m—sample mass (g), δ—sample thickness (cm), A–sample area (cm2) [The porosity of the nanofibrous materials was determined using a gravimetric method based on the following relation: ea (cm2) . The sam2) at ambient conditions, and the water contact angle was measured over 1 s with 10 frames per second. The water contact angle for each material was measured three times, and values are presented as mean ± standard deviation.Hydrophilic properties of CS/PEO nanofibers were studied using the sessile drop method . Droplets of 5 μL distilled water were dispensed onto the surface of the material . Spectra were detected three times in ATR mode and analyzed with the OMNIC 8.3 software, and representative spectrum for each sample is presented as a result.Rectangular samples of CS/PEO nanofibrous materials underwent a uniaxial stretching test according to previously described protocol . For thiThe test was conducted using Instron 3345 model  with crosshead speed 10 mm/min at ambient conditions which measured the maximum load and strain at rupture. Each experiment was carried out five times.SEM imaging and porosity measurements displayed that fibers occupy only a fraction of the volume of the material sample. One can determine this fraction from the 1-P relationship, which also applies to the cross-sectional area of the sample. Since only a fraction of fibers occupies the cross-sectional area of the sample, only this fraction of the material thickness transfers the applied load during tensile testing. This effect was accounted for in the data processing for tensile properties calculation. Due to poor mechanical properties of Control-2, fixed distance at which the probe was raised (about 2 mm) was applied to estimate its tensile strength and Young modulus. Absorption capability was measured using simulate wound exudate (SWE) fluid on a self-constructed thermostated inclined steal plate at 32 ± 1 °C according to ,61. EachThe protocol of bioadhesion study was approved by the Local Bioethical Committee, Bialystok, Poland (permission number R-I-002/305/2019). Freshly excised human skin was obtained from the clinic of surgery and aesthetic medicine in Bialystok from women undergoing face lift. Tissue specimens were preserved in the isotonic saline solution, frozen at −20 °C directly after the surgery and kept no longer than 60 days. In prior experiments, skin was thawed at ambient conditions, cut into pieces, and microscopically checked for tissue integrity.Bioadhesive properties of nanofibers in contact with excised human skin were carried out with texture analyzer TA.XT. Plus  . Uncoate2. The cells were seeded into six-well plates (with density of 5 × 105 cells per well) and cultured for 48 h in optimal growth conditions . Extraction of CS/PEO 10% nanofibrous material in serum-free medium at concentrations 10, 20, 40 mg/mL took place at 37 °C for 72 h according to ISO EN 10993-5:2009 [Human dermal fibroblasts cell line HDFa from American Type Culture Collection  were propagated according to the enclosed procedure protocol in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal bovine serum, 50 U/mL penicillin and 50 μg/mL streptomycin at 37 °C in an atmosphere with 5% CO3-5:2009 . After f3-5:2009 .2 humidified atmosphere. Then the culture medium was discarded, cells were rinsed three times with Phosphate Buffered Saline (PBS) and incubated for 4 h in MTT solution at 37 °C. Afterwards, medium was removed from the wells and the cells were lyzed with DMSO and Sorensen’s buffer. The absorbance of purple formazan derivative in living cells was measured spectrophotometrically at 570 nm . Cell viability cultured in the presence of nanofibers extracts was calculated as a percent of control cells not exposed to CS/PEO material. Additional control, pure PEO and pure CS were dispersed in medium at concentrations 32 mg/mL and 8 mg/mL, respectively-referring to those occurred in the highest tested concentration of nanofiber extract. Experiments were performed for at least three independent replicates.According to Carmicheal et al. , the viaDisruption of the mitochondrial membrane potential (MMP) was analyzed using the lipophilic cationic fluorochrome (JC-1 MitoScreen kit) as previously described . Subsequ2, 95% relative humidity), tissues were thoroughly rinsed with PBS, blotted to remove the tested material, and transferred to fresh medium. After 42 h-incubation period, the MTT assay was carried out by transferring the tissues to 24-well plates containing MTT medium at a concentration of 1 mg/mL. After 3 h incubation, the blue formazan salt formed by cellular mitochondria was extracted with 2.0 mL/tissue of isopropanol and the optical density of the extracted formazan was determined spectrophotometrically at 570 nm. Sterile PBS was used as negative control whereas 5% (w/w) SDS solution was used as positive control and examined concurrently with nanofibers. Test was performed in triplicate.The test consists of a topical exposure of nanofibrous material to a reconstructed human epidermis model EpiDerm™ followed by a cell viability assay which was measured by dehydrogenase conversion of MTT. Test was performed according to the enclosed procedure described in Section 7.4. of EPI-200-SIT Protocol ,66. Brie2. Images were taken after 4 h, 24 h and 48 h incubation using a phase contrast microscope  at a 100× magnification. The wound closure expressed as a change in pixels intensity between cell monolayer and scratch area over time was assessed by ImageJ software  and calculated as a percentage of the initial scratch area at 0 h.The scratch test was used to evaluate the migration ability of fibroblast HDFa cells in the presence of CS/PEO 10% nanofibers extract and pure CS or PEO controls. Cells were cultured in six-well plates until approximately 100% confluence. Thereafter, vertical scratches were produced using 20 μL pipette tips . After wp < 0.05). The difference among the mean fiber sizes, mean water contact angle values and bioadhesive behavior of analyzed materials were tested using the Kruskal-Wallis test with post hoc nonparametric Dunn’s test for multiple comparisons. The difference among the mean porosity and mean values of the mechanical properties of analyzed materials was tested in one-way ANOVA with post hoc Tukey’s test for multiple comparisons.The normality of fiber size distributions, porosity, water contact angle and results from mechanical and bioadhesive properties was tested using the Shapiro-Wilk test . The presence of a hydrophobic layer impacted mechanical properties of nanofibers, though the obtained values were comparable to those attained for commercial hydrofiber-like materials comprised of carboxymethylcellulose sodium or calcium alginate. CS/PEO 10% nanofibers exhibited cytocompatibility at concentration 10–20 mg/ml and fibroblast viability comparable to the control group at all tested time points. Solution blow-spun material did not induce irritancy in contact with EpiDerm™ tissue, which confirmed its compatibility with a skin model. Additionally, an in vitro scratch assay demonstrated its ability to promote fibroblast migration even at early time points. Overall, obtained results show that CS-enriched, solution blow-spun PEO nanofibers with a poly(dimethylsiloxane) outer layer may serve as valuable material per se for skin healing and regeneration.


Canarium ovatum Engl.), an indigenous tree found in the Philippines, is highly regarded for its fruit due to its high economic value. During processing, the pulp is often discarded as waste but contains considerable amounts of oil and bioactive minor lipid components. The present study explored the antioxidant and antibacterial properties of saponified diethyl ether extract of pili pulp oil and related this activity to the nature of compounds present in the extract through GCMS. The extract indicated the elution of 18 major compounds which are mostly cyclic triterpenic  and phytosterol  class of compounds. Characterization of the bioactivity of the extract showed high antioxidant activities measured by DPPH radical scavenging (EC50: 74.45 ± 1.29 μg/mL) and lipid peroxidation inhibition (EC50: 3.02 ± 0.06 μg/mL) activities that were comparable with that of α-tocopherol. Moreover, an observed bactericidal activity was demonstrated by the extract against E. coli and S. typhi with MIC values of 40 and 35 μg/mL, respectively. The observed bioactivity of the pili pulp oil extract can be attributed to these compounds which may provide desirable health benefits.Pili ( Canarium ovatum Engl., locally known as pili, is an indigenous tree commonly found in the Philippines which is cultivated for its edible fruit [le fruit . Pili nule fruit . In pilile fruit , 4. ThesS. aureus, E. faecalis, and P. aeruginosa are studied by Amoussa et al. [Antioxidants and antimicrobial agents play a significant role in the food sector primarily because bacterial growth and lipid oxidation are the main factors that determine food quality loss and shelf-life reduction. Oftentimes, synthetic additives such as BHA/BHT are commonly added to food products to inhibit the process of lipid oxidation and microbial growth and to extend their shelf-life. However, a shift to naturally derived compounds is seen and increasingly being sought by many companies due to possible adverse effects associated with long-term intake of synthetic compounds , 6. Phyta et al.  and Nzoga et al. . Phenolia et al. .Hence, the present study explored the potential of minor lipid components in pili pulp oil as a source of phytosterols and cyclic triterpenoids with antioxidant and antibacterial properties. The interest in these naturally derived compounds is not only due to their biological activity but also to maximize the economic potential of pili pulp oil.Canarium ovatum Engl.) fruits were obtained from a local market at Goa, Camarines Sur, Philippines. Microbial strains  used for the antibacterial activity assay were obtained from the Philippine National Collection of Microorganisms (PNCM), BIOTECH, UPLB, College, Los Baños, Laguna, Philippines. All other chemicals and standards were purchased commercially.Pili (n-hexane at 1 : 4 ratio of dried pulp weight (g) to solvent volume (mL). After 12 h of extraction at room temperature with constant agitation, the oil was recovered by solvent evaporation by using a rotary evaporator.Pili fruits were manually depulped by blanching in lukewarm water for about 15–20 min. The pulps were then collected and dried in a convection-type oven at 70°C overnight or until moisture content reached about less than 3%. Extraction of oil was carried out by using The unsaponifiable fraction of oil was obtained by saponification following the method of Almeida et al.  with somμm film thickness . The initial oven temperature was held at 190°C for 1 min then raised to 300°C at 15°C/min and kept constant for 10 min. Helium was used as the carrier gas with a constant flow rate of 1 mL/min. The injector, MS ion source, and MS interface temperatures were set at 310, 230, and 280°C, respectively. A sample injection of 1 μL was performed in a split mode of 10 : 1 and peaks were detected in full scan acquisition mode from m/z 50 to 500. Identification of the individual components was performed by NIST mass spectral library on the basis of the mass fragment and e/z values of each component. The relative concentration of each peak was computed based on the total ion count.Profiling of SDEE was performed on a Shimadzu GCMS-QP2020 equipped with a Shimadzu AOC-20i Plus auto-injector  under electron impact ionization at 70 eV. Separation of components was carried out in SH-Rxi-5Sil MS capillary column with dimensions of 30 m × 0.25 mm ID × 0.25 α-tocopherol were used as a blank and positive control, respectively. The absorbance of the resulting mixture was measured at 516 nm and the percent radical scavenging activity was calculated based on the following equation:The scavenging activity of SDEE against DPPH radical was evaluated by using the method of  with som50 value is defined as the concentration of sample required to scavenge 50% of DPPH radical under the assayed conditions.The ECμg/mL of SDEE (in chloroform) and 0.5 mL of 10% egg yolk homogenate (w/v in distilled water) was mixed in a screwcapped tube and the volume was made up to 1.0 mL by adding distilled water. Then, 0.05 mL 0.07 M FeSO4 (in distilled water) was added, and the mixture was incubated at 37°C for 30 min to induce lipid peroxidation. A 0.05 mL of 20% (w/v) trichloroacetic acid solution (TCA) in distilled water and 1.0 mL 0.1% (w/v) thiobarbituric acid solution (TBA) in distilled water was added to the mixture, vortexed, and heated in a water bath at 80°C for 30 min. After cooling, 3 mL of butanol was added, and the mixture was centrifuged at 3000 rpm for 5 min. The absorbance of the upper layer was measured against 3 mL butanol at 512 nm. Chloroform and α-tocopherol were used as blank and positive controls, respectively. The lipid peroxidation inhibition activity was calculated by using the following equation:A mixture of 0.1 mL of 0.1–10 50 value is defined as the concentration of sample required to inhibit 50% of lipid peroxidation under the assayed conditions.The ECS. aureus, B. cereus, E. coli, S. typhi, and P. aeruginosa was carried out by disk diffusion method [8 CFU/mL was uniformly spread onto individual solid media plates of Muller–Hinton agar by using a sterile cotton swab. Disks of 6 mm in diameter were impregnated, until saturation, with 0.1 mg/mL of the extract. The disks were then allowed to dry placing in the inoculated agar. Chloramphenicol and chloroform served as positive and negative controls, respectively. The inoculated plates were incubated at 37°C for 18–24 h. Antimicrobial activity was evaluated by measuring the zone of inhibition against the test organisms.Qualitative antimicrobial activity of SDEE against n method . Brieflyμg/mL. Then, 295 μL of each dilution was transferred into a 96-well microplate. A 5 μL of test bacterial suspension (1.0 × 106 CFU/mL) was inoculated to obtain a final concentration of 1.67 × 104 CFU/mL and a final volume of 300 μL per well. The inoculum (positive control) and culture medium (negative control) were put into the first column of the microplate, and the chloramphenicol antibiotic control ranging from 0.5 to 75 μg/mL was in the final column. Each plate was wrapped loosely with cling film to prevent dehydration during incubation for 18–24 h at 37 °C. Subsequently, 10 μL of bacterial growth indicator, resazurin at 6.75 mg/mL, was added to wells, which were then incubated for 30 min at 37 °C. The lowest concentration of the extract that visually showed no growth was determined as MIC.The MIC of the extract exhibiting sensitivity to the tested microorganism based on the disk diffusion assay was determined following the methods outlined by Eloff  with somP < 0.05.All experiments and measurements were carried out in triplicate. The data were presented as mean ± SEM and were analyzed by using one-way ANOVA. Means were compared using Tukey's post hoc comparison test by using R software . Significant differences between means were determined at Extraction of oil revealed 23.92 ± 0.21% yield, expressed in dry weight basis of pulp. The unsaponifiable fraction of oil obtained from diethyl ether extraction showed 1.0294 ± 0.0501%. These values were slightly lower than our previous findings [β-Amyrin showed the highest abundance of around 34.75%, followed by α-amyrin and β-sitosterol with 20.92 and 15.78%, respectively. Other phytosterols identified in SDEE include brassicasterol, stigmasterol, campesterol, and fucosterol , costerol . These wcosterol .α-and β-isomers, are generally found in different plant part extracts such as in C. tramdenum bark which contains 0.03 mg/g β-amyrin [M. barteri and S. longifolia also contain high amounts of α-amyrin as reported by Ce et al. [Amyrin, both β-amyrin . Areal pe et al.  and Saeie et al. . Other te et al. , 23.50 values of 3.02 μg/mL with that of α-tocopherol (2.92 μg/mL), a known antioxidant compound, though a moderate activity was observed in terms of its DPPH radical scavenging activity with a slightly higher EC50 value of 74.45 μg/mL in SDEE as compared to 65.91 μg/mL in control.The antioxidant activity of the SDEE was analyzed in terms of scavenging activity against DPPH radical and the ability to inhibit lipid peroxidation in the egg yolk system. As shown in β-sitosterol, and stigmasterol have been shown to exhibit scavenging activities against DPPH radical and provide hepato- and neuro-protection of hydrogen peroxide-induced oxidative stress levels [Myrcianthes pungens leaves revealed high antioxidant activity with antioxidant protection equivalent to the Trolox of 137 and 129% for α-and β-amyrin, respectively, at 500 μg/mL [Terpenoids and sterols, in general, have been shown to exert antioxidant properties owing to their hydroxyl group that participates via hydrogen atom transfer or single electron transfer mechanism in quenching reactive oxygen species , 25. It s levels . Isomers00 μg/mL .E. coli and S. typhi with 10.3 and 11.7 mm zone of inhibition, respectively, at 0.1 mg/mL. The MIC showed that 40 and 35 μg/mL of the extract were able to inhibit the growth of E. coli and S. typhi, respectively. The extract was not active or did not show antibacterial activity in S. aureus, B. cereus, and P. aeruginosa at 0.1 mg/mL.The antibacterial potential of SDEE against 5 common food pathogens is shown in β-amyrin exerting antibacterial activities against the 5 pathogens tested in this study. In a separate study, hexane extract of Manilkara subsericea fruit which is mostly α-andβ-amyrin acetate showed a MIC value of 250 μg/mL against S. aureus [β-sitosterol that were isolated from Icacina trichantha, showed high antimicrobial properties against B. subtilis, E. coli, and C. albicans.The antibacterial activity of SDEE can be attributed to the high amyrin content which was also observed by Abdel-Raouf et al.  in sever. aureus . Aside f. aureus  reportedE. coli as demonstrated by Broniatowski et al. [The regulatory activity of amyrin including other triterpenoids in disrupting pathways responsible for cell division and protein synthesis, as well as destabilization of bacterial cell membrane and inhibition of cell growth are some of the plausible mechanisms of action of these compounds . Furtheri et al. .α-tocopherol, a known antioxidant compound. The extract also exerts antibacterial activities against E. coli and S. typhi which are bacterial pathogens of concern, especially in food preparation. GCMS profiling revealed 18 compounds majority of which are cyclic triterpenes and phytosterols such as α- and β-amyrin, lupenone, β-sitosterol, brassicasterol, and stigmasterol. Our results suggest that these bioactive compounds are responsible for the observed bioactivities which may provide desirable health benefits.Extraction, saponification, and diethyl ether fractionation of the unsaponifiable matter of pili pulp oil showed strong antioxidant properties as measured by its scavenging activity against DPPH radical and lipid peroxidation inhibition activities and are found to be comparable to


Oocyte (OC), embryo (EC), and ovarian tissue cryopreservation (OTC) are options for fertility preservation (FP) before going through gonadotoxic cancer treatment, or anticipated fertility decline in benign ovarian diseases, or for planned OC. The aim of this study is to report outcomes of FP in a single tertiary hospital in Korea.This is a retrospective study of OC, EC, and OTC cycles. All patients who visited or were referred to the infertility clinic at the Department of Obstetrics and Gynecology for the purpose of FP between 2010 and October 2021 were included.A total of 564 controlled ovarian stimulation cycles were conducted in 416 women. Three hundred fifty-seven women underwent 494 OC cycles. Most patients were diagnosed with breast cancer (22.4%), followed by endometriomas (21.9%), and then by planned OC (20.7%). Cases of OC have increased over the years, peaking at 109 cycles in 2019 compared to one in 2010. Fifty-nine women underwent 70 EC cycles, and breast cancer (50.8%) was the most common indication. Repetitive OC and EC cycles were undergone in 92 and 9 women, respectively , yielding a maximum number of 33 oocytes or 23 embryos being cryopreserved per patient. The utilization rate was 3.1% (11/357) in OC and 16.9% (10/59) in EC. Twenty-six women underwent OTC, and gynecologic cancer was the most common indication . One woman had the cryopreserved ovarian tissue retransplanted and successfully generated embryos.OC, EC, and OTC are possible options for preserving fertility, and these opportunities should be provided for women at risk of fertility decline or those who are eager to protect their future fertility. This is the first report on long-term FP outcomes in a single tertiary center in Korea. We expect that there will be more cases over the years and more women returning to use their gametes or embryos for pregnancy. Fertility preservation (FP) is becoming an increasingly important field in women’s reproductive lives, and its demands are increasing rapidly. FP is considered in women before going through gonadotoxic cancer treatment or before anticipated fertility decline in the treatment of benign ovarian diseases.Advancements in cancer treatment have resulted in decreased overall cancer mortality rates and increased long-term survival rate. The increased survival rate in reproductive-age women with cancer has, in turn, led to more women to have a chance to focus on long-term quality of life issues, such as motherhood. However, such cancer treatments, including chemotherapy and radiotherapy, inevitably risk compromising future fertility  due to iPlanned oocyte cryopreservation (OC) or embryo cryopreservation (EC) is another indication of FP for women who are not married yet or want to postpone childbearing. In South Korea, the mean age at first live birth was delayed from 27.6 years in 1993 , which iThe third, and the most overlooked, indication of FP is women who require surgical treatment of benign ovarian diseases, which anticipate the decrease of ovarian reserve. In particular, endometriosis of the ovary is the biggest threat to women’s fertility, since endometriosis itself can reduce the ovarian reserve by inflicting damage to the surrounding ovarian tissue  and ovarThere are three main strategies of FP, which the present study focuses on: OC, EC, and ovarian tissue cryopreservation (OTC). Other strategies include ovarian suppression with gonadotropin-releasing hormone (GnRH) agonists and ovarian transposition. However, using GnRH agonists for ovarian protection is controversial  and not The aim of this study is to report outcomes of FP of over 10 years in a single tertiary hospital in Korea and to see its improvements. This study focuses not only on FP in cancer patients, and planned cryopreservation, but also on FP in patients prior to anticipated fertility decline in the treatment of benign ovarian diseases. This study hopes to improve clinicians’ awareness toward the various strategies of FP in any woman of reproductive age who needs or wants to preserve fertility.This single-center study retrospectively analyzed the FP outcomes of patients who were referred to or who visited the Fertility Center of Seoul National University Bundang Hospital between 2010 and October 2021. The indication for FP was one of the following: anticipated chemo- or radiation therapy, before scheduled ovarian surgery, or planned FP. Patients’ characteristics including age, body mass index (BMI), diagnosis of the disease, anti-Müllerian hormone (AMH) level, and indication of FP were included as study parameters. The mean number of oocytes retrieved and the number of cryopreserved oocytes or embryos from all the controlled ovarian stimulation (COS) cycles for each patient were recorded. The follow-up data of all the patients included were extracted from medical records.The study received institutional review board approval (B-2110-714-104), and the informed consent was waived for a large number of patients with guaranteed anonymity.All patients who had COS cycles for oocyte retrieval carried out for FP were enrolled without any age limitations. Cases with cycle cancelations due to any reason were excluded, for example, follicular growth failure.All cycles (n = 564) were conducted with gonadotropin-releasing hormone (GnRH) antagonist protocols. Cycles were initiated in the early follicular phase of the menstrual cycle in patients with benign diseases or those undergoing planned OC. For cancer patients, since it was important not to delay their planned cancer therapy, random start cycles were applied in most patients regardless of the early follicular phase timing. All patients underwent COS cycles with either recombinant follicle-stimulating hormone  or FSH combined with luteinizing hormone (LH) [human menopausal gonadotropin (hMG), Menopur; Ferring, Malmo, Sweden). The starting dose of gonadotropin was determined according to the age and ovarian reserve of the patients. When the leading follicle reached the size of 13–14 mm, a GnRH antagonist  was used to prevent premature LH surge. Final oocyte maturation was triggered by the injection of a recombinant human chorionic gonadotrophin (rhCG)  or 0.2 mg triptorelin , or a combination of the two (250 μg of rhCG plus 0.2 mg of triptorelin), when two or more leading follicles measured 18 mm in diameter. In patients with hormone-dependent cancers , an aromatase inhibitor  was coadministered with gonadotropin daily starting from the COS cycles to at least 7 days after oocyte retrieval. Transvaginal ultrasound-guided oocyte retrieval was carried out under sedation 36 h after triggering. Metaphase II (MII) oocytes were selected for OC. For EC, the additional process of intracytoplasmic sperm injection (ICSI) using sperm from the husband was carried out and cultured until cleavage stage. One patient had her embryos cultured until blastocyst stage. The embryos were classified as “good quality” for cleavage-stage embryos with grade 6B or more as assessed by the Steer method  and for The oocytes and embryos were vitrified using the Kitazato Vitrification Cryotop kit  according to the manufacturer’s protocol , 19. WheOTC was carried out in the following patients: (1) those who could not delay their cancer treatment, (2) prepubertal females, (3) those with primary ovarian insufficiency (POI) or impending POI . Ovarian tissue retrieval was performed mainly by minimally invasive laparoscopic surgery. In all cases, the entire unilateral ovary was removed.The OTC protocol has been previously described , 21. As The primary outcomes were cryopreserved oocytes or embryos and cumulative numbers of these parameters. Secondary outcomes were the total number of retrieved oocytes and the number of mature oocytes. Other parameters such as distribution by diagnosis, changes in annual treatment pattern, and usage rate of cryopreserved oocytes or embryos were also analyzed.All statistical analyses were performed using the Statistical Package for the Social Sciences version 25.0 . Continuous variables were demonstrated as median  values as indicated and categorical variables were demonstrated as “n (%)” in the tables.A total of 564 COS cycles of OC or EC in 416 women were performed. Of this, 357 women underwent 494 OC cycles. The median age at the time of OC in all patients was younger than 35 years , and the median AMH level was 2.17 ng/ml (range 0.01–25.00 ng/ml). The most common indication for OC was breast cancer , followed by ovarian endometrioma , and then by planned OC . The characteristics of the patients who underwent OC are shown in via fresh in vitro fertilization (IVF). The utilization rate of the cryopreserved oocytes was 3.1% (11 out of 357 women), and one woman resulted in a successful pregnancy and a live birth. The main reasons for not attempting to become pregnant were due to their unmarried status (205 women), and 51 women were still receiving cancer treatment. Eight women who underwent OC died due to their original malignancy (Only 41 women out of the 357 who underwent OC (11.5%) were attempting to conceive, and the other 316 women were not currently attempting (88.5%). Out of the 41 women attempting, 13 women succeeded to conceive naturally, and 2 women succeeded lignancy Table 2.via fresh IVF. Ten women attempted embryo transfer (ET) using cryopreserved embryos and 6 women succeeded in pregnancy, leading to a pregnancy rate of 60% (6 out of 10 women). Out of these 6 women, 5 of them had benign ovarian cysts and one had thyroid cancer. The most common reason for not attempting to become pregnant in women who underwent EC was since they were still receiving cancer treatment (23 women). Two women who underwent EC died due to their original malignancy , followed by hematologic cancer  Table 5.The present study showed the experience of FP in a single tertiary center during a relatively long period. For women facing imminent fertility decline or those who desired to postpone their childbearing plan, physicians must provide the patients appropriate counseling and FP opportunities. Furthermore, there were cumulative effects on the number of cryopreserved oocytes or embryos through repetitive COS. Hence, the repeat of COS, as long as it does not affect the treatment of the cancer or benign diseases, can lead to the optimal number of oocytes or embryos being cryopreserved.The past 11 years of FP experience of this study showed an annual increasing trend of both OC and EC being performed. Other reports have shown a similar trend of increase in FP being performed in patients with cancer and planned OC. This is likely due to the increasing attention by physicians to the women’s desire of future pregnancy, after a stronger collaboration between their cancer center and fertility center , and alsNevertheless, FP in women before undergoing surgery for benign ovarian cyst has been overlooked. Even when taking care to preserve as much normal ovarian tissue as possible when performing ovarian cystectomy, it cannot be done perfectly and ovarian function decline is bound to be present after surgery and situations are worse with low basal AMH or bilateral cases . This isThe current report does not provide data regarding the rate of women who were offered FP in the first place. A report by Chung et al.  found thOur results showed an ongoing pregnancy rate of 9.1% per embryo transfer (1 out of 11) in OC cycles and a much higher ongoing pregnancy rate of 60% per embryo transfer (6 out of 10) in EC cycles. The ongoing pregnancy rate using cryopreserved oocytes in OC cycles was relatively low in our center. An explanation for such low pregnancy rate is due to the low number of women attempting pregnancy and an even lower utilization rate (only 41 women who underwent OC and 17 women who underwent EC were attempting to conceive). As we already mentioned, the utilization rate of cryopreserved oocytes was 3.1% (11 out of 357 women) with a similar value of 4.5% in another literature , and theRegarding OTC, the total number of cases was much lower compared to EC and OC cycles, even though ASRM stated that OTC is no longer considered experimental . Only onThe limitation of the present study is the retrospective nature and that the results of this single center cannot represent the whole of South Korea. In addition, the absolute number of OTC being performed is relatively low in South Korea, and live birth after its transplantation has not yet been achieved. On the other hand, a strong advantage of this report is that it is the first to provide data regarding three FP techniques of OC, EC, and OTC. Also, studies focusing on OC prior to anticipated ovarian function decline in benign ovarian diseases are rare, which should not be overlooked, especially in patients with endometriosis when infertility is of high concern.In conclusion, centers performing FP must widen indications for OC, EC, and OTC, so that women are not deprived of a chance of pregnancy using their own gametes or embryos. We hope sharing data regarding outcomes of FP will improve awareness of both clinicians and women at risk of fertility potential decline and help identify the limits of the procedure for its further improvement in the future.Supplementary Material. Further inquiries can be directed to the corresponding author.The original contributions presented in the study are included in the article/JRL, SKK, and CSS designed and conducted the research. YJC and SBK analyzed the data. YJC and YHH wrote the article. YHH and JRL reviewed the article. All authors read and approved the final article.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


This study aims to improve the quality of English teaching in contemporary colleges and universities, so as to cultivate more English translation talents. Taking corpus, English translation, and teaching practice as the main research horizons, this study analyzes the application of master of translation and interpreting (MTI) course design, English translation, and task migration by combining the task migration algorithm under Internet of Things (IoT) with the self-built corpus, so as to realize the cultivation of translation talents and design of teaching practice. A translation corpus is constructed, a two-way interactive online course is designed, and the experimental results of the complete local migration algorithm , random migration algorithm , and greedy heuristic migration algorithm  used in English teaching practice courses are analyzed and compared. The experimental simulation results reveal that the GHM algorithm proposed in this study shows good system stability, its duration is 60% better than that of the CLM algorithm, and its system throughput is increased by 50% compared with the CLM algorithm. In addition, the maximum delay time has little effect on the system throughput. When the system time slot length is fixed at 20 ms, the user migration rate of the genetic algorithm is the highest under the different total numbers of users. In addition, in view of the wide application of neural network in English translation teaching, this study establishes an English translation evaluation model based on the combination of particle swarm optimization (PSO) algorithm and neural network and compares it with the traditional neural network model in simulation experiments. The results show that the addition of PSO algorithm can effectively improve the convergence speed of artificial neural network (ANN), reduce the training time of the model, and improve the accuracy of the ANN network. Using the PSO algorithm to train the neural network, the optimal solutions of different particle swarms can be obtained, and the error is small. The PSO-ANNs model can promote the quality of English translation teaching and improve the English translation ability of the students. Therefore, applying the task transfer algorithm and PSO algorithm to the practice of English translation teaching has greatly improved the efficiency of the English classroom. To sum up, this study provides new ideas for the curriculum design of contemporary college English teaching and has reference value for the cultivation of college English translation talents. With the development of today's economic globalization, the professionalization of the ancient profession of translation is getting higher and higher. Translation services belonging to the language service industry, such as professional document translation, interpretation and conference translation, editing and typesetting, multimedia translation and production, website and software localization, and language service outsourcing, have gradually entered the business scope of translation companies. The standardization and institutionalization of translation project management, translation customer service, and translation quality monitoring are also getting higher and higher, with obvious service industry characteristics and increasingly clear professional requirements. This requires employees in this industry to have special professional qualities, abide by professional ethics, understand professional characteristics, and possess professional abilities and qualifications. Of course, they also need industry associations and other organizations to formulate industry standards and practice rules, establish access mechanisms, and carry out training. The most important teaching goal for English teaching in contemporary colleges and universities is improving the translation ability and translation cognitive ability of students . TranslaThe choice of translation theory teaching content is based on the teaching objectives of English translation theory. Only clear teaching objectives can be integrated into the classroom in actual teaching work . The maiIt is known from the current research that most of the studies of English corpus development and the master of translation and interpretation (MTI) discipline focus on one aspect rather than combining them. Therefore, the work of this study is mainly divided into two parts. The first part is the combination of task transfer algorithm under the IoT and self-built corpus. The application of curriculum design, English translation, and task transfer for the master of translation and interpretation (MTI) is analyzed, so as to realize the cultivation of translation talents and the design of teaching practice. Then, a translation corpus is constructed, and a two-way interactive online course is designed. In the second part, the PSO algorithm is combined with ANNs to establish an English translation evaluation model based on PSO-ANNs.The contribution of this study is reflected in the research of English translation teaching practice, corpus construction method, and task transfer algorithm technology. It constructs an English-Chinese/Chinese-English bilingual translation corpus and designs a two-way interactive online English translation course combined with the systematic task transfer algorithm in the MEC scenario. Compared with the completely local transfer algorithm and the random transfer algorithm, the greedy heuristic transfer algorithm proposed in this study has higher performance in English teaching practice courses. The innovation of this study can be summarized as two points. The first point is to use the IoT task migration algorithm under edge computing to study English translation theory and design teaching practice courses. The second point is to establish an English translation evaluation model based on the PSO algorithm and neural network.In recent years, the increasing frequency of international exchanges and the continuous improvement of tourism policies have promoted the sustainable and rapid development of China's tourism industry. The application of technologies such as big data, cloud computing, and the IoT has also spawned smart tourism. With the rapid progression of international tourism, the translation and translation talents have gradually become imperative . The infAs an analog corpus, the monolingual corpus is often ignored in the parallel text research . The conThe edge computing unit describes the functions and characteristics of the terminal node in the MEC system after resources encapsulation , which iEdge computing allows end devices to migrate storage and computing tasks to network edge nodes, such as base stations, wireless access points, and edge servers. While meeting the computing capability expansion requirement of the terminal device, it can effectively save the transmission link resources of the computing task between the cloud server and the terminal device. Edge computing is mainly composed of four layers of functional structure: core infrastructure, edge computing center, edge network, and edge devices.The edge server carries most of the functions of the cloud computing center in the cloud computing mode and can provide services and computing support to each edge terminal, which can lay a solid foundation for the progress of mobile computing . HoweverIn the scenario of multiuser collaboration, the edge computing task offloading network connection model is shown in The characteristics of the link system are summarized as follows. ① The connection between the incoming line and the outgoing line must go through one or several interlevel connections, and this connection or connecting device is a link. ② The link and the selected outgoing line are occupied at the same time. ③ When the lines are selected, only the links that can be connected to idle outgoing lines should be selected. This method of line selection is called conditional selection.A system link model is constructed to improve the overall throughput of the system to reduce the network load of core gateways such as cloud servers in the future big data environment. The working principle of this model is sinking the server to the edge of the network, which greatly shortens the transmission distance compared with gathering all tasks in the cloud center for processing . The nodTpt and transmission cost Tts for node ni to migrate to node nj and the credibility tfj of node nj is calculated in the following equation, which is called the matching degree Dij between the node task and service node:The weighted Euclidean distance of the calculation cost W1, W2, and W3 are the corresponding matching weights of the calculation cost Tpt, transmission cost Tts, and credibility tfj of node nj in the actual environment, respectively. According to the actual environment of the system, different values can be assigned , where vmax is the maximum speed allowed by the particle. pij represents the position of particle i on j dimension, pij ∈ , where pmax is the maximum space position that the particle is allowed to move. λ is the inertia weight, used to balance global search and local search. bij represents the individual extreme value of particle i on j dimension. gij represents the global extreme value of particle i on j dimension. c1 and c2 are acceleration factors that characterize the ability of particles to self-summarize and learn from high-quality particles in the group. r1 and r2 represent random numbers between . β is the constraint factor, which is used to control the weight of speed.In the above equation, The data collected in this study is used for research, and the translation quality in the parallel corpus must be guaranteed, so the data collector must have a certain degree of bilingual language ability in Chinese and English . The datDuring the construction of corpus, the input of a large number of corpora will inevitably lead to phenomena such as misplacement, garbled characters, and symbol errors . At thatCorpus labeling refers to the division of corpus components for further retrieval and research, which is called part-of-speech labeling. Since the corpus contains bilingual languages, there are differences in labeling methods for different languages. When the English corpus is labelled, the corpus part of speech is divided and abbreviated, and the text is annotated with a tokenizer. However, the machine labeling cannot reach 100% accuracy, so manual verification is required .When the Chinese texts in the corpus are labelled, the parts of speech should be labeled on the ICTCLAS platform firstly. Then, the corresponding rhetorical means are labelled on the corpus according to a prominent rhetorical feature in the tourism discourse. Because there is no ready-made software to complete such marking, it needs to be done manually. During manual review, the rhetorical features contained in the sentence are obtained through the study of the phonetic, vocabulary, and grammatical features of the text. Different rhetorical devices are specifically labelled with sentences as a unit. The corpus mainly adopts autonomous coding methods, such as expressing similes, expressing puns, and expressing parallelism. Although manual coding is a huge project, once these annotations are completed, they will provide evidence for us to reveal the differences in the rhetorical usage of the English and Chinese tourism texts and the differences in the aesthetic concepts behind the texts. This is of great help to comparative rhetoric and comparative aesthetics .Corpus alignment is mainly for parallel corpora of Chinese and English texts, and the main steps are sentence division and sentence coding. The Chinese in the bilingual translation corpus is divided into five wildcards in words, which are ^p, ? ^p, ! ^p, “ ^p”, and : ^p. Replacing the five wildcards with the corresponding five punctuation marks can achieve a better sentence effect. The sentence division of the English corpus only requires four wildcards . The above steps are repeated again. Finally, the text is imported into Word Smith Tool 6.0. It can view the text that has been divided by clicking the “right button” next to the corpus and then clicking “view.” The text can be saved and exported by clicking “Save.”Multiuser collaborative service is only one of many application scenarios of edge computing. The task migration model of migrating multiuser tasks to the same edge cloud base station is analyzed in this study. Smart classrooms, smart phones, smart glasses, smart bracelets, and other smart IoT terminals have to perform complex and quantitative computing tasks in the development of future application-oriented businesses such as smart classrooms, smart transportation, smart cities, smart homes, and smart tourism. However, the battery energy of these smart IoT devices is often very limited, which cannot meet the life and work needs of human beings well. Edge computing well embodies the characteristics of distributed computing. The calculation is performed in the local area network (LAN) without transmitting the computing data or raw data to the cloud for processing through the network. It can reduce the computing load of the terminal device and can respond to the user request quickly.T is divided into disjoint time frames firstly, and then each different frame is divided into different channels. The end users correspond to different channels, and the edge server uses the different channels to distinguish the end users, so as to realize the network link of multiple terminals and a single edge server. The MECO migration system with K as the number of end users is shown in The system model for calculating migration in this study is the time division multiple access MECO system in long-term evolution (LTE). The total migration time slot The operation process of the system in Computing migration includes five modules of application perception, perception collection, task splitting, overall scheduling, and terminal execution. The computing migration decision process involves the number of end users, edge servers, channels, and bandwidth. Moreover, it may move with the end user's location. Therefore, the bandwidth, channel gain, communication noise, and terminal transmission power of the system are considered jointly in this study to establish a migration model for edge computing in the case of multiple terminals and multiple edge service servers. The migration steps of the MEC system are shown in A mobile device is composed of a migration decision unit, a local processing unit, and a transmission unit. The mobile device migrates some computing-intensive computing tasks to the MEC server for execution through the transmission unit, so as to solve the limited computing power of the mobile terminal. The MEC server is a virtual machine device deployed at a wireless access point and installed in a small data center, which can provide powerful IT services for mobile devices.The energy consumption optimizations in multiterminal single edge service computing migration of CLM algorithm, RM algorithm, and generative algorithm are simulated to analyze the energy consumption performance of the three migration algorithms. Massively controlled experiments are performed. The simulation experiment parameters for MEC calculation migration are shown in K refers to the total number of IoT terminal users in system. T is the total migration time slot. Ck is the calculation consumption of the terminal calculation k. σ represents the variance of Gaussian white noise. B refers to the channel bandwidth. Pk refers to the transmission power of the IoT terminal. Sk is the computing power of the terminal calculation k, and ek is the energy consumption of each cycle for local calculation of terminal k.In The two-way interactive online education model is based on the first generation of online education, which increases the interactive feedback link, considers the learner's learning experience and learning effect, and emphasizes the interactive nature of learning and the use of technology to deliver education and teaching content. It also contains feedback from learners and organizes students to communicate and discuss. This education model mainly focuses on three-screen courses, massive open online courses (MOOCs), and video open courses.In addition to the test questions, assignments, and learning works contained in the traditional two-way interactive education model, the translation course design is supplemented with a new real-time barrage function. According to general functions, MTI students use the tools of the corpus, such as retrieval, clustering, collocation, vocabulary, and keyword list to analyze and translate the original text in the parallel translation corpus. Many comments may suddenly appear on the screen within a certain second and float on the screen like a horizontal version. This kind of online comment method is called “barrage” by netizens. At present, barrage videos are mostly used in media fields such as movies, television, and live broadcast platforms. However, the potential value of barrage videos such as distance education and online learning has received little attention and exploration by domestic and foreign researchers. One of the major disadvantages of traditional two-way interactive online education is the inability to get real-time feedback and interaction from students. The addition of the real-time barrage function can reflect and solve problems in the learning process in a timely manner, greatly improving the learning efficiency and enhancing the participation of MTI students. Compared with other majors, MTI focuses on the active participation of students. Therefore, online teaching based on real-time barrage is very suitable for actual teaching of MTI. The teaching content is detailed and practical, which further promotes the innovation of MTI teaching. The design of the translation course is shown in The two-way interactive teaching mode in the network environment shown in A translation workshop platform suitable for students and teachers is constructed based on three self-built tourism corpora. The users of the platform are classified into teachers, students, and managers. To ensure the security of the platform, teachers and students have to log in with the teacher ID number and student ID number, and administrators have to register and authenticate according to their ID cards. At present, the functions of the platform are divided into corpus experience area, practice area, information mutual assistance area, and acceptance area. The corpus experience area is the area where platform personnel perform functions such as denoising, labeling, indexing, term extraction, and alignment and realize the real meaning of corpus-assisted translation. The practice area focuses on practical operations and is mainly divided into the role playing of project managers, translation managers, translators, project managers, proofreaders, typesetting personnel, and corpus administrators. Platform personnel can conduct actual drills according to their own needs and improve themselves during the drills. The information mutual assistance zone is relatively simple, and platform staff can share operation and translation experience as well as learning materials such as translation tools and corpus links. The acceptance area is the area where the management personnel are located. This area collects suggestions and opinions from platform personnel. In this way, the platform is continuously optimized, and the errors are corrected to further improve the operational level of translation workshops. The plan of the translation corpus is shown in The corpus stores the language materials that have actually appeared in the actual use of the language, so the example sentence database should not usually be regarded as a corpus.Corpus is the basic resource carrying language knowledge, but it is not equal to language knowledge.Real corpus needs to be processed  before it can become a useful resource.The corpus has three characteristics:Artificial neural network is usually composed of multiple neurons and multiple nodes according to the algorithm principles of PSO algorithm and neural network. Multilayer feedforward neural network model is the most widely used neural network model, which mainly includes input layer, output layer, and hidden layer. The input layer obtains the required information from the outside and then inputs the obtained information into the neural network for subsequent processing. The hidden layer implements processing, and the output layer can output the processed results to the desired location. The neural network learning ability analysis model shown in In this study, the PSO algorithm is firstly improved. The random distribution method is used to obtain inertia weights to maintain the diversity of the population and improve the search ability. At the same time, the asynchronous change strategy is used to change the value of the learning factor to strengthen the learning ability of the particles and accelerate the convergence to global optimal solution. Secondly, the improved PSO is combined with feedforward neural network algorithm. Finally, for the complex and multidimensional factors, a variety of dimensionality reduction processing methods are used to obtain the factors of the main relevant information.Then, the following equation is used to determine the number of hidden layer nodes of the neural network model:J is the number of hidden layer nodes, M is the number of output layer nodes, and N is the number of input layer nodes. According to the above equation, the relationship between the number of network training times and the number of hidden layer nodes is obtained. The optimization principle of PSO algorithm is introduced into the neural network, which enhances the global optimization capability of the algorithm. The composite algorithm uses the movement and update of particles to find the optimal solution of the neural network at the initial stage. The algorithm flow is shown below.In the above equation, (i)Data preprocessing is implemented via the normalization method, and the purpose is reducing the noise of the original data.(ii)The output value is denormalized.xi is the normalized value, zi is the denormalized value, λ1 is the lower limit, λ2 is the upper limit, zimax is the maximum value in the original data, and zimin is the minimum value in the original data.Determine the number of hidden nodes.Determine the hidden layers.Determine the activation function by selecting the Sigmoid function as the activation function.The second step is setting the neural network related parameters.The third step is PSO initial position and speed setting.The initial position isThe initial speed isOptimal location record is(i)Hidden output layer th) is the weighted sum of the input of the h layer. aih is the connection parameter between the i layer and the h layer. xi is the activation value of the i layer. θh is the offset of the h layer.((ii)Output layer istj) is the weighted sum of the input of the j-th layer. Yj is the output of the j-th layer.((iii)Calculate reverse difference:(iv)w and bias vector Δθ are calculated and updated:The weight matrix ΔThe fourth step is the network output:whj and θj represent the new weight matrix and bias vector, respectively. whj′ and θj′ are the original weight matrix and bias vector, respectively.In the above equation, Calculate particle fitness.Update particle position and velocity.PSO-ANNs model.The fifth step is as follows:The mobile edge computing system designed in this study is divided into three parts. The first part is the mobile device, the second part is the edge server, and the third part is the cloud server. In this work, the mobile client is used to collect data through mobile phone software and upload it to the edge server. The edge server extracts the discriminant information through the projection matrix trained by the cloud server and compares it with the relevant information to obtain the relevant results and returns it to the mobile terminal. Its related feature information will be sent to the cloud server as a new training sample. The cloud server uses the projection matrix and feature information in the training database to send it to the edge server. In this study, Alibaba Cloud is selected as the cloud server, the hierarchical discriminant analysis algorithm proposed in this study is adopted to train the projection matrix obtained in the database, and the projection matrix was applied to extract the feature information of the data in the database and send it to the edge server for identification. A large amount of identifiable data is stored in the cloud server and trained using a hierarchical discriminant analysis feature extraction algorithm, and the projection matrix and feature information of all images are obtained, which is sent to the edge server as the basis for translation recognition.Model parameter setting is to set the two input objects. Input1 is undertaken as an example. Input2 and input1 perform the same operation, and the input form of the defined data is input1 = keras.layers.Input,name = 'input1′), which represents a 16  ×  4 matrix. Then the data goes into the convolutional layer, where input1 is renamed, input1 is named Convolution1, and input2 is named Convolution2. After the operation of the convolution layer, the data will be subjected to a secondary operation in the pooling layer. After the operation of the pooling layer is completed, the data processing of the CNN part is basically completed, and then the data processed by the CNN is used as the input of the particle swarm algorithm. The ReLU function is used as the activation function.Construction of the dataset: It can be seen from the previous data acquisition and preprocessing that, to fully train the model to achieve the true prediction of the problem, the data needs to be divided into training set and test set. The training set is used for model training and model parameter determination, and the test set is used to finally test the performance of the model. In this work, the training set and test set were divided according to the ratio of 9 : 1.This research experiment is completed under the Ubuntu 16.04 operating system. The model programming language uses Python 3.6, and the compilation environment uses software Anaconda. The training in this study is implemented based on the Keras framework. Keras is a Python-based deep learning framework built on TensorFlow 2.0, which can easily define and train almost all types of deep learning models.The experiment simulation results of the edge collaboration are illustrated in Further simplification of the data in In Figures Figures Figures 8, 2.8 × 108, and 6.5 × 108, respectively. The data shows that the third algorithm is the most degraded, followed by the first two. Figures Figures The simulation results on the relationship between the total number of migrated users and the migration rate are shown in In The comparison on performances of different migration algorithms is shown in The PSO-ANNs model is used to verify the teaching effect of English translation. First, the sample collection of students' English translation learning characteristics is completed, and then it is proceeded in two steps. The first step uses PSO algorithm to train the neural network. The second step is evaluating and testing the validity of the model. The algorithm dataset is from Tianchi Datasets of Alibaba, and 2,000 students' English translation data are taken as the dataset of the algorithm in this research. However, due to space issues, the datasets are not provided in this article. The established model evaluates the quality of English translation teaching and compares it with ANNs model. The results are shown in The training results of the algorithm are shown in In the context of the IoT based on edge computing, this study analyzes the English translation teaching practice, corpus construction methods, and task transfer algorithm technology. Combined with the system task transfer algorithm of the MEC scenario, an English-Chinese/Chinese-English bilingual translation corpus was constructed, and a two-way interactive online English translation course is designed. GHM algorithm shows better performance than CLM algorithm and RM algorithm in actual English teaching. In addition, the addition of PSO algorithm can effectively improve the convergence speed of the neural network, reduce the model training time, and improve the accuracy of the neural network. The neural network is trained by the PSO algorithm, and the optimal solutions of different particle populations are obtained. Under the same experimental conditions, the model error is 0.23 when the number of particles is 5; the model error is 0.32 when the number of particles is 10; and the error of the model is 0.05 when the number of particles is 15. The model performs best at this point. However, this study also has some shortcomings. Firstly, it only focuses on two-way interactive online English translation courses and does not discuss preclass preview and after-class maintenance. Secondly, due to the limited resources and less test data of the system, further exploration is needed in the future to supplement and improve the application of the proposed task transfer algorithm in English practice classroom research.In future research, it will discuss the application of edge computing technology in “interactive” translation teaching mode. It is believed that the combination of edge computing technology and “interactive” translation teaching mode can make up for some deficiencies in traditional translation teaching, which contributes to the realization of translation teaching goals.