bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrophilic Excipient-Independent Drug Release from SLA-Printed Pellets
Authors: Xu Lei , Yang Qingliang , Qiang Wei , Li Huijie , Zhong Weizhen , Pan Siying , Yang Gensheng
Published: October 2021

Three-dimensional (3D) printing technology, specifically stereolithography (SLA) technology, has recently created exciting possibilities for the design and fabrication of sophisticated dosages for oral administration, paving a practical way to precisely manufacture customized pharmaceutical dosages with both personalized properties and sustained drug release behavior. However, the sustained drug release achieved in prior studies largely relies on the presence of hydrophilic excipients in the printing formulation, which unfortunately impedes the printability and formability of the corresponding printing formulations. The current study developed and prepared mini-sized oral pellets using the SLA technique and successfully accomplished a hydrophilic excipient-independent drug release behavior. With ibuprofen as the model drug, the customized photopolymerizable printing formulation included polyethylene glycol diacrylate (PEGDA) as a monomer and diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO) as a photoinitiator. The produced mini-sized pellets were thoroughly investigated for various factors, including their printability, physical properties, microscopic features, drug content, and drug-release profiles. The drug release profiles from the printed pellets that were larger size (3 mm and 6 mm) followed the Ritger–Peppas model, demonstrating that the release was influenced by both the diffusion of the dissolved drug and by the erosion of the hydrophilic excipients (PEG400). The profiles from the smaller printed pellets (1 mm and 2 mm) followed first release kinetics, not only illustrating that the release was impacted only by drug diffusion, but also indicating that there is a size boundary between the dependent and independent hydrophilic excipients. These results could create practical benefits to the pharmaceutical industry in terms of the design and development personalized dosages using the SLA printing technique with controllable drug release by manipulating size alone.
Generation of a Biomimetic Substitute of the Corneal Limbus Using Decellularized Scaffolds
Authors: Sánchez-Porras David , Caro-Magdaleno Manuel , González-Gallardo Carmen , García-García Óscar Darío , Garzón Ingrid , Carriel Víctor , Campos Fernando , Alaminos Miguel
Published: October 2021

Patients with severe limbal damage and limbal stem cell deficiency are a therapeutic challenge. We evaluated four decellularization protocols applied to the full-thickness and half-thickness porcine limbus, and we used two cell types to recellularize the decellularized limbi. The results demonstrated that all protocols achieved efficient decellularization. However, the method that best preserved the transparency and composition of the limbus extracellular matrix was the use of 0.1% SDS applied to the half-thickness limbus. Recellularization with the limbal epithelial cell line SIRC and human adipose-derived mesenchymal stem cells (hADSCs) was able to generate a stratified epithelium able to express the limbal markers p63, pancytokeratin, and crystallin Z from day 7 in the case of SIRC and after 14–21 days of induction when hADSCs were used. Laminin and collagen IV expression was detected at the basal lamina of both cell types at days 14 and 21 of follow-up. Compared with control native limbi, tissues recellularized with SIRC showed adequate picrosirius red and alcian blue staining intensity, whereas limbi containing hADSCs showed normal collagen staining intensity. These preliminary results suggested that the limbal substitutes generated in this work share important similarities with the native limbus and could be potentially useful in the future.
g-C3N4/MoS2 Heterojunction for Photocatalytic Removal of Phenol and Cr(VI)
Authors: Rapti Ilaeira , Bairamis Feidias , Konstantinou Ioannis
Published: October 2021

In this study, molybdenum disulfide (MoS2) decorated on graphitic carbon nitride (g-C3N4) heterostructure catalysts at various weight ratios (0.5%, 1%, 3%, 10%, w/w) were successfully prepared via a two-step hydrothermal synthesis preparation method. The properties of the synthesized materials were studied by X-ray diffraction (XRD), attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FT-IR), UV–Vis diffuse reflection spectroscopy (DRS), scanning electron microscopy (SEM) and N2 porosimetry. MoS2 was successfully loaded on the g-C3N4 forming heterojunction composite materials. N2 porosimetry results showed mesoporous materials, with surface areas up to 93.7 m2g−1, while determined band gaps ranging between 1.31 and 2.66 eV showed absorption over a wide band of solar light. The photocatalytic performance was evaluated towards phenol oxidation and of Cr(VI) reduction in single and binary systems under simulated sunlight irradiation. The optimum mass loading ratio of MoS2 in g-C3N4 was 1%, showing higher photocatalytic activity under simulated solar light in comparison with bare g-C3N4 and MoS2 for both oxidation and reduction processes. Based on scavenging experiments a type-II photocatalytic mechanism is proposed. Finally, the catalysts presented satisfactory stability (7.8% loss) within three catalytic cycles. Such composite materials can receive further applications as well as energy conversion.
Cascaded Generation in Multimode Diode-Pumped Graded-Index Fiber Raman Lasers
Authors: Kuznetsov Alexey G. , Nemov Ilya N. , Wolf Alexey A. , Evmenova Ekaterina A. , Kablukov Sergey I. , Babin Sergey A.
Published: October 2021

We review our recent experimental results on the cascaded Raman conversion of highly multimode laser diode (LD) pump radiation into the first- and higher-order Stokes radiation in multimode graded-index fibers. A linear cavity composed of fiber Bragg gratings (FBGs) inscribed in the fiber core is formed to provide feedback for the first Stokes order, whereas, for the second order, both a linear cavity consisting of two FBGs and a half-open cavity with one FBG and random distributed feedback (RDFB) via Rayleigh backscattering along the fiber are explored. LDs with different wavelengths (915 and 940 nm) are used for pumping enabling Raman lasing at different wavelengths of the first (950, 954 and 976 nm), second (976, 996 and 1019 nm) and third (1065 nm) Stokes orders. Output power and efficiency, spectral line shapes and widths, beam quality and shapes are compared for different configurations. It is shown that the RDFB cavity provides higher slope efficiency of the second Stokes generation (up to 70% as that for the first Stokes wave) with output power up to ~30 W, limited by the third Stokes generation. The best beam quality parameter of the second Stokes beam is close to the diffraction limit (M2~1.3) in both linear and half-open cavities, whereas the line is narrower (<0.2 nm) and more stable in the case of the linear cavity with two FBGs. However, an optimization of the FBG reflection spectrum used in the half-open cavity allows this linewidth value to be approached. The measured beam profiles show the dip formation in the output pump beam profile, whereas the first and second Stokes beams are Gaussian-shaped and almost unchanged with increasing power. A qualitative explanation of such behavior in connection with the power evolution for the transmitted pump and generated first, second and third Stokes beams is given. The potential for wavelength tuning of the cascaded Raman lasers based on LD-pumped multimode fibers is discussed.
Modal Analysis of Pseudo-Schell Model Sources
Authors: Santarsiero Massimo , Martínez-Herrero Rosario , Piquero Gemma , de Sande Juan Carlos González , Gori Franco
Published: October 2021

All pseudo-Schell model sources have been shown to possess the same continuous set of circularly symmetric modes, all of them presenting a conical wavefront. For keeping energy at a finite level, the mode amplitude along the radial coordinate is modulated by a decreasing exponential function. A peculiar property of such modes is that they exist in the Laplace transform’s realm. After a brief discussion of the near-zone, we pass to the far-zone, where the field can be evaluated in closed form. The corresponding features of the intensity distribution are discussed.
Long-Term Potato Virus X (PVX)-Based Transient Expression of Recombinant GFP Protein in Nicotiana benthamiana Culture In Vitro
Authors: Sindarovska Yana , Kuchuk Mykola
Published: October 2021

Plant molecular farming has a great potential to produce valuable proteins. Transient expression technology provides high yields of recombinant proteins in greenhouse-grown plants, but every plant must be artificially agroinfiltrated, and open greenhouse systems are less controlled. Here, we propose to propagate agrobacteria-free plants with high-efficient long-term self-replicated transient gene expression in a well-controlled closed in vitro system. Nicotiana benthamiana plant tissue culture in vitro, with transient expression of recombinant GFP, was obtained through shoot induction from leaf explants infected by a PVX-based vector. The transient expression occurs in new tissues and regenerants due to the natural systemic distribution of viral RNA carrying the target gene. Gene silencing was delayed in plants grown in vitro, and GFP was detected in plants for five to six months. Agrobacteria-free, GFP-expressing plants can be micropropagated in vitro (avoiding an agroinfiltration step), “rejuvenated” through regeneration (maintaining culture for years), or transferred in soil. The mean GFP in the regenerants was 18% of the total soluble proteins (TSP) (0.52 mg/g of fresh leaf weight (FW). The highest value reached 47% TSP (2 mg/g FW). This study proposes a new method for recombinant protein production combining the advantages of transient expression technology and closed cultural systems.
Triterpenoid and Steroidal Saponins Differentially Influence Soil Bacterial Genera
Authors: Nakayasu Masaru , Yamazaki Shinichi , Aoki Yuichi , Yazaki Kazufumi , Sugiyama Akifumi
Published: October 2021

Plant specialized metabolites (PSMs) are secreted into the rhizosphere, i.e., the soil zone surrounding the roots of plants. They are often involved in root-associated microbiome assembly, but the association between PSMs and microbiota is not well characterized. Saponins are a group of PSMs widely distributed in angiosperms. In this study, we compared the bacterial communities in field soils treated with the pure compounds of four different saponins. All saponin treatments decreased bacterial α-diversity and caused significant differences in β-diversity when compared with the control. The bacterial taxa depleted by saponin treatments were higher than the ones enriched; two families, Burkholderiaceae and Methylophilaceae, were enriched, while eighteen families were depleted with all saponin treatments. Sphingomonadaceae, which is abundant in the rhizosphere of saponin-producing plants (tomato and soybean), was enriched in soil treated with α-solanine, dioscin, and soyasaponins. α-Solanine and dioscin had a steroid-type aglycone that was found to specifically enrich Geobacteraceae, Lachnospiraceae, and Moraxellaceae, while soyasaponins and glycyrrhizin with an oleanane-type aglycone did not specifically enrich any of the bacterial families. At the bacterial genus level, the steroidal-type and oleanane-type saponins differentially influenced the soil bacterial taxa. Together, these results indicate that there is a relationship between the identities of saponins and their effects on soil bacterial communities.
Molecular Insights of Fruit Quality Traits in Peaches, Prunus persica
Authors: Veerappan Karpagam , Natarajan Sathishkumar , Chung Hoyong , Park Junhyung
Published: October 2021

Fleshy fruits are the most demanded fruits because of their organoleptic qualities and nutritional values. The genus Prunus is a rich source of diversified stone/drupe fruits such as almonds, apricots, plums, sweet cherries, peaches, and nectarines. The fruit-ripening process in Prunus involves coordinated biochemical and physiological changes resulting in changes in fruit texture, aroma gain, color change in the pericarp, sugar/organic acid balance, fruit growth, and weight gain. There are different varieties of peaches with unique palatable qualities and gaining knowledge in the genetics behind these quality traits helps in seedling selection for breeding programs. In addition, peaches have shorter post-harvest life due to excessive softening, resulting in fruit quality reduction and market loss. Many studies have been executed to understand the softening process at the molecular level to find the genetic basis. To summarize, this review focused on the molecular aspects of peach fruit quality attributes and their related genetics to understand the underlying mechanisms.
Screening for Selective Anticancer Activity of 65 Extracts of Plants Collected in Western Andalusia, Spain
Authors: Calderón-Montaño José Manuel , Martínez-Sánchez Sara María , Jiménez-González Víctor , Burgos-Morón Estefanía , Guillén-Mancina Emilio , Jiménez-Alonso Julio José , Díaz-Ortega Patricia , García Felipe , Aparicio Abelardo , López-Lázaro Miguel
Published: October 2021

Finding cytotoxic drugs with a high selectivity towards cancer cells is crucial to improve the low survival rates of patients diagnosed with metastatic cancers. Since plants are an important source of anticancer drugs, we have screened 65 extracts from 45 plants collected in several areas of Western Andalusia (Spain) for cytotoxic activity on lung cancer cells versus lung normal cells. An extract from the leaves of Tetraclinis articulata (Vahl) Mast. (Cupressaceae) showed a marked cytotoxicity (IC50 = 0.37 ± 0.03 μg/mL) and selectivity (selectivity index = 378.3) against the lung cancer cells; cisplatin, 5-fluorouracil, and an extract from the leaves of Taxus baccata L. (Taxaceae) were less cytotoxic and selective. Extracts from Cascabela thevetia (L.) Lippold (Apocynaceae), Frangula alnus Mill. (Rhamnaceae), Iberis ciliata subsp. contracta (Pers.) Moreno (Brassicaceae), Juniperus macrocarpa Sm (Cupressaceae), and Pancratium maritimum L. (Amaryllidaceae) also showed selective cytotoxicity (selectivity index > 10). Active extracts were also tested against a panel of cancer cell lines from a variety tissues. The plants identified in this work are potential sources of natural compounds with selective toxicity towards cancer cells.
Potential of Essential Oils from Anise, Dill and Fennel Seeds for the Gypsy Moth Control
Authors: Kostić Igor , Lazarević Jelica , Šešlija Jovanović Darka , Kostić Miroslav , Marković Tatjana , Milanović Slobodan
Published: October 2021

The gypsy moth (Lymantria dispar L. (Lepidoptera: Erebidae)) is a serious pest of hardwood forests. In the search for an environmentally safe means of its control, we assessed the impact of different concentrations of essential oils (EOs) from the seeds of three Apiaceae plants (anise Pimpinella anisum, dill Anethum graveolens, and fennel Foeniculum vulgare) on behavior, mortality, molting and nutritional physiology of gypsy moth larvae (GML). EOs efficacy was compared with commercial insecticide NeemAzal®-T/S (neem). The main compounds in the Eos were trans-anethole in anise; carvone, limonene, and α-phellandrene in dill; and trans-anethole and fenchone in fennel seed. At 1% EOs concentration, anise and fennel were better antifeedants and all three EOs were more toxic than neem. Neem was superior in delaying 2nd to 3rd larval molting. In the 4th instar, 0.5%, anise and fennel EOs decreased relative consumption rate more than neem, whereas all three EOs were more effective in reducing growth rate, approximate digestibility and efficiency of conversion of food into body mass leading to higher metabolic costs to GML. Decrease in consumption and metabolic parameters compared to control GML confirmed that adverse effects of the EOs stem from both pre- and post-ingestive mechanisms. The results indicate the potential of three EOs to be used for gypsy moth control.
Growth and Physiological Performance of a Coastal Species Trifolium fragiferum as Affected by a Coexistence with Trifolium repens, NaCl Treatment and Inoculation with Rhizobia
Authors: Dūmiņš Kārlis , Andersone-Ozola Una , Samsone Ineta , Elferts Didzis , Ievinsh Gederts
Published: October 2021

The aim of the present study was to analyze the growth and physiological performance of two coexisting species, Trifolium fragiferum, and Trifolium repens, under the effect of NaCl and rhizobial symbiosis. Seeds of T. fragiferum and T. repens were collected from populations in the wild, and plants were cultivated in an automated greenhouse, two plants per container. Three basic types of planting were performed: (1) both plants were T. fragiferum (single species), (2) one T. fragiferum and one T. repens (species coexistence), (3) both plants were T. repens (single species). For every basic type, three subtypes were made: (1) non-inoculated, (2) inoculated with rhizobia taken from T. fargiferum, (3) inoculated with rhizobia taken from T. repens. For every subtype, half of the containers were used as control, and half were treated with NaCl. Shoot fresh mass of plants was significantly (p < 0.001) affected by species coexistence, inoculant, and NaCl. Three significant two-way interactions on plant shoot growth were found: between species coexistence and NaCl (p < 0.001), inoculant and species (p < 0.05), and NaCl and species (p < 0.001). A significant three-way interaction between inoculant, NaCl, and species (p < 0.001) indicated different responses of shoot growth of the two species to inoculant type and NaCl. NaCl treatment was an important factor for T. fragiferum, resulting in better growth in conditions of species coexistence, but the positive effect of bacterial inoculant was significantly more pronounced. A decrease in peroxidase activity in leaves was a good indicator of relative NaCl tolerance, while the absence/presence of rhizobial inoculation was reflected by changes in leaf chlorophyll concentration and photochemical activity of photosystem II. It can be concluded that interaction between biotic and abiotic factors affected the outcome of the coexistence of the two Trifolium species. Distribution of T. fragiferum in sea-affected habitats seems to be related to a higher competitive ability with allied species at increased substrate salinity, based on better physiological salinity tolerance.
DNA Barcoding of Two Thymelaeaceae Species: Daphne mucronata Royle and Thymelaea hirsuta (L.) Endl
Authors: Alkaraki Almuthanna K. , Aldmoor Maisam A. , Lahham Jamil N. , Awad Mohammed
Published: October 2021

Daphne mucronata Royle and Thymelaea hirsuta (L.) Endl both belong to the Thymelaeaceae family. Both species are used traditionally to treat several diseases along with various daily applications by Jordanian Bedouins. Traditionally, those species are identified through personal proficiency, which could be misleading due to human errors or lack of expertise. This study aims to investigate an effective DNA barcoding method to identify and characterize Daphne mucronata Royle and Thymelaea hirsuta plant species at the molecular level. Daphne mucronata Royle and Thymelaea hirsuta were collected from the ancient city of Petra in the Southern part of Jordan. Sequences of candidate DNA barcodes were amplified (rbcL, matK, and rpoC1), sequenced, and aligned to the blastn database. Moreover, the obtained sequences were compared with available sequences of related species at the GenBank database. Our results showed that DNA barcoding successfully identifies the two plant species using any of chloroplast genes (rbcL, matK, or rpoC1). The results emphasize the ability of DNA barcoding for identifying and characterizing different plant species through the recruitment of different barcode loci in molecular identification.
Comprehensive Analyses of NAC Transcription Factor Family in Almond (Prunus dulcis) and Their Differential Gene Expression during Fruit Development
Authors: Zafar Zeeshan , Fatima Sidra , Bhatti Muhammad Faraz
Published: October 2021

As plant specific transcription factors, NAC (NAM, ATAF1/2, CUC2) domain is involved in the plant development and stress responses. Due to the vitality of NAC gene family, BLASTp was performed to identify NAC genes in almond (Prunus dulcis). Further, phylogenetic and syntenic analyses were performed to determine the homology and evolutionary relationship. Gene duplication, gene structure, motif, subcellular localization, and cis-regulatory analyses were performed to assess the function of PdNAC. Whereas RNA-seq analysis was performed to determine the differential expression of PdNAC in fruits at various developmental stages. We identified 106 NAC genes in P. dulcis genome and were renamed according to their chromosomal distribution. Phylogenetic analysis in both P. dulcis and Arabidopsis thaliana revealed the presence of 14 subfamilies. Motif and gene structure followed a pattern according to the PdNAC position in phylogenetic subfamilies. Majority of NAC are localized in the nucleus and have ABA-responsive elements in the upstream region of PdNAC. Differential gene expression analyses revealed one and six PdNAC that were up and down-regulated, respectively, at all development stages. This study provides insights into the structure and function of PdNAC along with their role in the fruit development to enhance an understanding of NAC in P. dulcis.
Effects of Shade and Planting Methods on the Growth of Heracleum moellendorffii and Adenophora divaricata in Different Soil Moisture and Nutrient Conditions
Authors: Youn Woo Bin , Hernandez Jonathan Ogayon , Park Byung Bae
Published: October 2021

In this study, the interacting effects of shade and planting methods on the growth and competitive ability of two understory plants Heracleum moellendorffii Hance and Adenophora divaricata Franch. & Sav. were investigated under different soil moisture and nutrient conditions. One-year-old seedlings were subjected to different light levels (0%, 35%, and 55% shade) and planting methods (monoculture and mixed) under contrasting soil moisture (1.2 L/m2 and 2.3 L/m2 of water) and soil nutrient conditions (unfertilized and fertilized). Here, shading significantly improved the height growth of H. moellendorffii (10–20 cm increase) in unfertilized and fertilized plots and at high soil moisture conditions. Contrarily, A. divaricata seedlings planted singly at full sunlight yielded a higher aboveground biomass growth (8–17 g plant−1), compared with those shaded and intercropped seedlings (0.9–3.9 g plant−1). The increased competitiveness of H. moellendorffii suppressed the growth of A. divaricata across different light conditions when planted together. The amount of light, soil moisture, and nutrients and their interactions significantly affected the growth of the seedlings, resulting in asymmetric interspecific competition between the two species. Results provide us with a better understanding of the environmental factors affecting plant growth for forest farming in the understory.
Phospholipids in Salt Stress Response
Authors: Han Xiuli , Yang Yongqing
Published: October 2021

High salinity threatens crop production by harming plants and interfering with their development. Plant cells respond to salt stress in various ways, all of which involve multiple components such as proteins, peptides, lipids, sugars, and phytohormones. Phospholipids, important components of bio-membranes, are small amphoteric molecular compounds. These have attracted significant attention in recent years due to the regulatory effect they have on cellular activity. Over the past few decades, genetic and biochemical analyses have partly revealed that phospholipids regulate salt stress response by participating in salt stress signal transduction. In this review, we summarize the generation and metabolism of phospholipid phosphatidic acid (PA), phosphoinositides (PIs), phosphatidylserine (PS), phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylglycerol (PG), as well as the regulatory role each phospholipid plays in the salt stress response. We also discuss the possible regulatory role based on how they act during other cellular activities.
An Artificial Lens Capsule with a Lens Radial Stretching System Mimicking Dynamic Eye Focusing
Authors: Wei Huidong , Wolffsohn James S. , Gomes de Oliveira Otavio , Davies Leon N.
Published: October 2021

Presbyopia is a common eye disorder among aged people which is attributed to the loss of accommodation of the crystalline lens due to the increasing stiffness. One of the potential techniques to correct presbyopia involves removing the lens substance inside the capsule and replacing it with an artificial lens. The development of such devices, e.g., accommodating intraocular lenses (AIOLs), relies on the understanding of the biomechanical behaviour of the lens capsule and the essential design verification ex vivo. To mimic the eye’s dynamic focusing ability (accommodation), an artificial lens capsule (ALC), from silicone rubber accompanied by a lens radial stretching system (LRSS) was developed. The ALC was manufactured to offer a dimension and deforming behaviour replicating the human lens capsule. The LRSS was calibrated to provide a radial stretch simulating the change of diameter of capsules during accommodating process. The biomechanical function of the ALC was addressed by studying its evolution behaviour and reaction force under multiaxial stretch from the LRSS. The study highlighted the convenience of this application by performing preliminary tests on prototypes of ophthalmic devices (e.g., AIOLs) to restore accommodation.
Comparative Characterization of Hot-Pressed Polyamide 11 and 12: Mechanical, Thermal and Durability Properties
Authors: Bahrami Mohsen , Abenojar Juana , Martínez Miguel Angel
Published: October 2021

Chemically speaking, polyamide 11 (PA11) and polyamide 12 (PA12) have a similar backbone, differing only in one carbon. From an origin point of view, PA11 is considered a bioplastic polyamide composed from renewable resources, compared to oil-based PA12. Each of them has a number of advantages over the other, which makes their selection a challenging issue. Depending on the target application, diverse assessments and comparisons are needed to fulfill this mission. The current study addresses this research gap to characterize and compare PA11 and PA12 manufactured by the hot press technique in terms of their mechanical, thermal and durability properties for the first time, demonstrating their potential for future works as matrices in composite materials. In this regard, different characterization techniques are applied to the hot-pressed polymer sheets, including X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The mechanical performance of the PA11 and PA12 sheets is compared based on tensile tests and shore hardness measurement. The durability behavior of these two polyamides is evaluated in water and relative humidity conditions at different aging times. The experimental results show the ductile behavior of PA12 with respect to the quasi-brittle PA11. Both have a relatively small water and moisture gain: 1.5 wt% and 0.8 wt%, respectively. The higher crystallinity of PA12 (2.1 times more than PA11) with γ-phase is one of the leading parameters to achieve better mechanical and durability properties. The FTIR spectra displayed slight acid hydrolysis. Accordingly, absorbed water or moisture does not cause plasticization; thus, neither hardness nor dimension changes.
In Situ Functionalization of Iron Oxide Particles with Alginate: A Promising Biosorbent for Retention of Metal Ions
Authors: Lucaci Alina-Roxana , Bulgariu Dumitru , Bulgariu Laura
Published: October 2021

In this study, alginate extracted from marine algae biomass was used for the functionalization of iron oxide particles obtained in situ. This procedure ensured a complete recovery of the alginate from the aqueous solution obtained after extraction and allowed the preparation of a new biosorbent. The obtained iron oxide microparticles functionalized with alginate (Alg-Fe3O4-MPs) were analyzed (FTIR spectrometry, energy dispersive X-ray spectroscopy and scanning electron microscopy), and their biosorptive performance was tested for the removal of Cu(II), Co(II) and Zn(II) ions. The optimal conditions were established as pH = 5.4, adsorbent dosage of 2 g/L, contact time of minimum 60 min and room temperature (23 ± 1 °C). The retention of metal ions was quantitative (99% for Cu(II), 89% for Co(II) and 95% for Zn(II)) when the concentration of metal ions was less than 0.80 mmol M(II)/L. The Langmuir model was found to be the best fitted model for the equilibrium data, while biosorption kinetics followed the pseudo-second order model. Biosorption processes were spontaneous (ΔG0 < 0), endothermic (ΔH0 > 0), and accompanied by an increase in entropy (ΔS0 > 0). The high maximum biosorption capacity of Alg-Fe3O4-MPs and its good regeneration highlight the potential of this biosorbent for applications in decontamination processes.
Representative Volume Element (RVE) Analysis for Mechanical Characterization of Fused Deposition Modeled Components
Authors: Ferretti Patrich , Santi Gian Maria , Leon-Cardenas Christian , Fusari Elena , Donnici Giampiero , Frizziero Leonardo
Published: October 2021

Additive manufacturing processes have evolved considerably in the past years, growing into a wide range of products through the use of different materials depending on its application sectors. Nevertheless, the fused deposition modelling (FDM) technique has proven to be an economically feasible process turning additive manufacture technologies from consumer production into a mainstream manufacturing technique. Current advances in the finite element method (FEM) and the computer-aided engineering (CAE) technology are unable to study three-dimensional (3D) printed models, since the final result is highly dependent on processing and environment parameters. Because of that, an in-depth understanding of the printed geometrical mesostructure is needed to extend FEM applications. This study aims to generate a homogeneous structural element that accurately represents the behavior of FDM-processed materials, by means of a representative volume element (RVE). The homogenization summarizes the main mechanical characteristics of the actual 3D printed structure, opening new analysis and optimization procedures. Moreover, the linear RVE results can be used to further analyze the in-deep behavior of the FDM unit cell. Therefore, industries could perform a feasible engineering analysis of the final printed elements, allowing the FDM technology to become a mainstream, low-cost manufacturing process in the near future.
The Role of the Mechanical, Structural, and Thermal Properties of Poly(l-lactide-co-glycolide-co-trimethylene carbonate) in the Development of Rods with Aripiprazole
Authors: Turek Artur , Rech Jakub , Borecka Aleksandra , Wilińska Justyna , Kobielarz Magdalena , Janeczek Henryk , Kasperczyk Janusz
Published: October 2021

In this work, we aimed to determine the role of the mechanical, structural, and thermal properties of poly(l-lactide-co-glycolide-co-trimethylene carbonate) (P(l-LA:GA:TMC)) with shape memory in the formulation of implantable and biodegradable rods with aripiprazole (ARP). Hot melt extrusion (HME) and electron beam (EB) irradiation were applied in the formulation process of blank rods and rods with ARP. Rod degradation was carried out in a PBS solution. HPLC; NMR; DSC; compression and tensile tests; molecular weight (Mn); water uptake (WU); and weight loss (WL) analyses; and SEM were used in this study. HME and EB irradiation did not influence the structure of ARP. The mechanical tests indicated that the rods may be safely implanted using a pre-filled syringe. During degradation, no unfavorable changes in terpolymer content were observed. A decrease in the glass transition temperature and the Mn, and an increase in the WU and the WL were revealed. The loading of ARP and EB irradiation induced earlier pore formation and more intense WU and WL changes. ARP was released in a tri-phasic model with the lag phase; therefore, the proposed formulation may be administered as a delayed-release system. EB irradiation was found to accelerate ARP release.
The Effect of SEBS/Halloysite Masterbatch Obtained in Different Extrusion Conditions on the Properties of Hybrid Polypropylene/Glass Fiber Composites for Auto Parts
Authors: Vuluga Zina , Sanporean Catalina-Gabriela , Panaitescu Denis Mihaela , Teodorescu George Mihail , Corobea Mihai Cosmin , Nicolae Cristian Andi , Gabor Augusta Raluca , Raditoiu Valentin
Published: October 2021

Masterbatches from a linear poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) and halloysite nanotubes (HNT-QM) were obtained in different conditions of temperature and shear using two co-rotating twin-screw extruders. The influence of screw configuration and melt processing conditions on the morpho-structural, thermal and mechanical properties of masterbatches at macro and nanoscale was studied. A good dispersion of halloysite nanotubes and better thermal stability and tensile and nanomechanical properties were obtained at a lower temperature profile and higher screw speed. The effect of masterbatches, the best and worst alternatives, on the properties of a polypropylene (PP)–glass fiber (GF) composite was also evaluated. Double hardness, tensile strength and modulus and four times higher impact strength were obtained for PP/GF composites containing masterbatches compared to pristine PP. However, the masterbatch with the best properties led further to enhanced mechanical properties of the PP/GF composite. A clear difference between the effects of the two masterbatches was obtained by nanoindentation and nanoscratch tests. These analyses proved to be useful for the design of polymer composites for automotive parts, such as bumpers or door panels. This study demonstrated that setting-up the correct processing conditions is very important to obtain the desired properties for automotive applications.
Investigating a Commercial Functional Adhesive with 12-MDPB and Reactive Filler to Strengthen the Adhesive Interface in Eroded Dentin
Authors: Belmar da Costa Madalena , Delgado António HS , Amorim Afonso Tomás , Proença Luís , Ramos Ana Sofia , Mano Azul Ana
Published: October 2021

To compare the adhesive interface of eroded dentin formed by a functional dental adhesive and a gold standard strategy, by testing microtensile bond strength (μTBS), hardness/elastic modulus. Permanent sound human molars were randomly allocated to four experimental groups, all subject to artificial erosion (0.05 M citric acid; 3× daily, 5 days). Groups included control Clearfil SE Bond 2 (CFSE), and experimental group Clearfil SE Protect (CFP), at two different time points-immediate (24 h) and long term (3 months–3 M). Samples were sectioned into microspecimens for μTBS (n = 8) and into 2-mm thick slabs for nanoindentation assays (n = 3). Groups CFSE_3M and CFP_3M were stored in artificial saliva. Statistical analysis included two-way ANOVA for μTBS data, while hardness/modulus results were analyzed using Kruskal–Wallis H Test (significance level of 5%; SPSS v.27.0). Although no significant differences were found between mean μTBS values, for different adhesives and time points (p > 0.05), a positive trend, with μTBS rising in the CFP_3M group, was observed. Regarding hardness, no significant differences were seen in the hybrid layer, considering the two variables (p > 0.05), while the reduced elastic modulus rose in CFP_3M when compared to 24 h. Thus, CFP shows similar mechanical and adhesive performance to CFSE in eroded dentin, although it may comprise promising long-term results. This is advantageous in eroded substrates due to their increased enzymatic activity and need for remineralization.
Concentration Dependent Single Chain Properties of Poly(sodium 4-styrenesulfonate) Subjected to Aromatic Interactions with Chlorpheniramine Maleate Studied by Diafiltration and Synchrotron-SAXS
Authors: Orozco Felipe , Hoffmann Thomas , Flores Mario E. , Lisoni Judit G. , Vega-Baudrit José Roberto , Moreno-Villoslada Ignacio
Published: October 2021

The polyelectrolyte poly(sodium 4-styrenesulfonate) undergoes aromatic–aromatic interaction with the drug chlorpheniramine, which acts as an aromatic counterion. In this work, we show that an increase in the concentration in the dilute and semidilute regimes of a complex polyelectrolyte/drug 2:1 produces the increasing confinement of the drug in hydrophobic domains, with implications in single chain thermodynamic behavior. Diafiltration analysis at polymer concentrations between 0.5 and 2.5 mM show an increase in the fraction of the aromatic counterion irreversibly bound to the polyelectrolyte, as well as a decrease in the electrostatic reversible interaction forces with the remaining fraction of drug molecules as the total concentration of the system increases. Synchrotron-SAXS results performed in the semidilute regimes show a fractal chain conformation pattern with a fractal dimension of 1.7, similar to uncharged polymers. Interestingly, static and fractal correlation lengths increase with increasing complex concentration, due to the increase in the amount of the confined drug. Nanoprecipitates are found in the range of 30–40 mM, and macroprecipitates are found at a higher system concentration. A model of molecular complexation between the two species is proposed as the total concentration increases, which involves ion pair formation and aggregation, producing increasingly confined aromatic counterions in hydrophobic domains, as well as a decreasing number of charged polymer segments at the hydrophobic/hydrophilic interphase. All of these features are of pivotal importance to the general knowledge of polyelectrolytes, with implications both in fundamental knowledge and potential technological applications considering aromatic-aromatic binding between aromatic polyelectrolytes and aromatic counterions, such as in the production of pharmaceutical formulations.
Organic Dye-Doped PMMA Lasing
Authors: Ang Pen Yiao , Čehovski Marko , Lompa Frederike , Hänisch Christian , Samigullina Dinara , Reineke Sebastian , Kowalsky Wolfgang , Johannes Hans-Hermann
Published: October 2021

Organic thin-film lasers gain interest as potential light sources for application in diverse fields. With the current development, they hold variety of benefits such as: low-cost, high-performance, and color-tunability. Meanwhile, the production is not complicated because both the resonator and the gain medium can be assembled by solution-processable organic materials. To our knowledge, information about using poly(methyl methacrylate) (PMMA) as a matrix for organic dye lasers was insubstantial. Herein, the feasibility of using organic dye-doped PMMA as an organic dye laser was tested. Six different sample designs were introduced to find out the best sample model. The most optimum result was displayed by the sample design, in which the gain medium was sandwiched between the substrate and the photoresist layer with grating structure. The impact of dye concentration and grating period on peak wavelength was also investigated, which resulted in a shift of 6 nm and 25 nm, respectively. Moreover, there were in total six various organic dyes that could function well with PMMA to collectively perform as ‘organic dye lasers’, and they emitted in the range of 572 nm to 609 nm. Besides, one of the samples was used as a sensor platform. For instance, it was used to detect the concentration of sugar solutions.
A Thermoresponsive Chitosan/β-Glycerophosphate Hydrogel for Minimally Invasive Treatment of Critical Limb Ischaemia
Authors: Herron Caroline , Hastings Conn L. , Herron-Rice Clodagh , Kelly Helena M. , O’Dwyer Joanne , Duffy Garry P.
Published: October 2021

A reduction in blood supply to any limb causes ischaemia, pain and morbidity. Critical limb ischaemia is the most serious presentation of peripheral vascular disease. One in five patients with critical limb ischaemia will die within six months of diagnosis and one in three will require amputation in this time. Improving blood flow to the limb, via the administration of angiogenic agents, could relieve pain and avoid amputation. Herein, chitosan is combined with β-glycerophosphate to form a thermoresponsive formulation (chitosan/β-GP) that will flow through a syringe and needle at room temperature but will form a gel at body temperature. The chitosan/β-GP hydrogel, with or without the angiogenic molecule desferrioxamine (DFO), was injected into the mouse hind limb, following vessel ligation, to test the ability of the formulations to induce angiogenesis. The effects of the formulations were measured using laser Doppler imaging to determine limb perfusion and CD31 staining to quantify the number of blood vessels. Twenty-eight days following induction of ischaemia, the chitosan/β-GP and chitosan/β-GP + 100 µM DFO formulations had significantly (p < 0.001 and p < 0.05, respectively) improved blood flow in the ischaemic limb compared with an untreated control. Chitosan/β-GP increased vessel number by 1.7-fold in the thigh of the ischaemic limb compared with an untreated control, while chitosan/β-GP + 100 µM DFO increased vessel number 1.8-fold. Chitosan/β-GP represents a potential minimally invasive treatment for critical limb ischaemia.
Modification of Sulfonated Polyethersulfone Membrane as a Selective Adsorbent for Co(II) Ions
Authors: Ashour Gadeer R. , Hussein Mahmoud A. , Sobahi Tariq R. , Alamry Khalid A. , Alqarni Sara A. , Rafatullah Mohd
Published: October 2021

In the current study, a variety of sulfonated polyethersulfone (SPES)-based ion-exchange membranes were prepared and utilized as efficient and selective solid adsorbents for the detection of Co(II) ions in aquatic solutions. SPES membranes were treated with a variety of cations at a 2:1 ratio overnight. The produced materials were assessed via XRD, FT-IR, SEM, and TGA analyses. The structure of these materials was confirmed by FT-IR and XRD, which also confirmed the inclusion of Na+, NH4+, and amberlite on the SPES surface successfully. TGA analysis showed that the thermal stabilities of these materials were enhanced, and the order of stability was NH4-SPES > SPES > Na-SPES > A-SPES. Furthermore, the efficiency of these modified membranes for the determination and adsorption of a variety of metal ions was also examined by the ICP-OES analytical technique. A-SPES expressed a powerful efficiency of adsorption, and it showed an efficient as well as quantitative adsorption at pH = 6. Moreover, A-SPES displayed the highest adsorption capacity of 90.13 mg/g for Co(II) through the Langmuir adsorption isotherm.
The Evaluation of Simulated Environmental Degradation of Polycarbonate Filled with Inorganic and Organic Reinforcements
Authors: Swinarew Andrzej S. , Swinarew Beata , Flak Tomasz , Okła Hubert , Lenartowicz-Klik Marta , Barylski Adrian , Popczyk Magdalena , Gabor Jadwiga , Stanula Arkadiusz
Published: October 2021

This research aimed to examine the mechanical properties of polycarbonate-based composites filled with both organic and inorganic reinforcements before and after simulated environmental degradation. Series of polycarbonate-based samples were prepared in the form of thin tapes. Their rheological properties were examined. Then, the samples were exposed to artificial environmental conditions. Finally, their rheological properties were examined once more, and the results were compared with those obtained for untreated samples. This paper presents basic research on the application of inorganic fillers to polycarbonate in order to determine the influence of the filler on the behavior of the obtained material. The aim of the work was to determine the usefulness and purpose of using this type of filler in polycarbonates for applications in contact with ultraviolet radiation, especially medical applications.
Comparison of Polymeric Cyanoacrylate Adhesives with Suturing in Free Gingival Graft Stability: A Split Mouth Trial
Authors: AlJasser Reham N. , AlSarhan Mohammed A. , AlOtaibi Dalal H. , AlOraini Saleh , AlNuwaiser Rand , AlOtaibi Alanoud , Alduraihem Hessah , Habib Syed Rashid , Zafar Muhammad Sohail
Published: October 2021

The aim is to compare the use of Cyanoacrylate adhesives (CAA) to the conventional suturing technique in terms of free gingival grafts (FGG) stability and healing in lower anterior and premolar regions. A split mouth design was initiated on 22 participants. Each side (from 2nd premolar to central incisor) was randomized to either the control or test groups. In the control group, sutures were used to stabilize the FGG, while, in the test group, the FGG was stabilized with butyl-cyanoacrylate. Full-periodontal clinical parameters were employed to assess the periodontal health. FGG-related parameters assessed included the keratinized tissue width (KTW), gingival tissue thickness (GTT), FGG shrinkage% and pain using the VAS score. No significant differences in the mean values of the KTW nor FGG shrinkage% across six time points (p < 0.05) were observed, whereas highly significant differences in the mean values of GTT across six time points (F = 3.32; p = 0.008) were observed. The use of CAA in FGG stability and healing is comparable to conventional suturing for soft tissue grafts in terms of success outcomes. With its cost effectiveness, lesser time consumption, post-operative pain and comparable graft stability and dimensions, the use of CAA may be a promising alternative for conventional and microsurgical techniques for the stabilization of FGG in the oral cavity.
Enhanced Pseudocapacitive Performance of Symmetric Polypyrrole-MnO2 Electrode and Polymer Gel Electrolyte
Authors: Zhuo Wen-Jun , Wang Yen-Hua , Huang Chia-Tse , Deng Ming-Jay
Published: October 2021

Herein, the nanostructured polypyrrole-coated MnO2 nanofibers growth on carbon cloth (PPy-MnO2-CC) to serve as the electrodes used in conjunction with a quasi-ionic liquid-based polymer gel electrolyte (urea-LiClO4-PVA) for solid-state symmetric supercapacitors (SSCs). The resultant PPy-MnO2-CC solid-state SSCs exhibited a high specific capacitance of 270 F/g at 1.0 A/g in a stable and wide potential window of 2.1 V with a high energy/power density (165.3 Wh/kg at 1.0 kW/kg and 21.0 kW/kg at 86.4 Wh/kg) along with great cycling stability (capacitance retention of 92.1% retention after 3000 cycles) and rate capability (141 F/g at 20 A/g), exceeding most of the previously reported SSCs. The outstanding performance of the studied 2.1 V PPy-MnO2-CC flexible SSCs could be attributed to the nanostructured PPy-coated MnO2 composite electrode and the urea-LiClO4-PVA polymer gel electrolyte design. In addition, the PPy-MnO2-CC solid-state SSCs could effectively retain their electrochemical performance at various bending angles, demonstrating their huge potential as power sources for flexible and lightweight electronic devices. This work offers an easy way to design and achieve light weight and high-performance SSCs with enhanced energy/power density.