bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical Coherence Elastography as a Tool for Studying Deformations in Biomaterials: Spatially-Resolved Osmotic Strain Dynamics in Cartilaginous Samples
Authors: Alexandrovskaya Yulia , Baum Olga , Sovetsky Alexander , Matveyev Alexander , Matveev Lev , Sobol Emil , Zaitsev Vladimir
Published: January 2022

This paper presents a recently developed variant of phase-resolved Optical Coherence Elastography (OCE) enabling non-contact visualization of transient local strains of various origins in biological tissues and other materials. In this work, we demonstrate the possibilities of this new technique for studying dynamics of osmotically-induced strains in cartilaginous tissue impregnated with optical clearing agents (OCA). For poroelastic water-containing biological tissues, application of non-isotonic OCAs, various contrast additives, as well as drug solutions administration, may excite transient spatially-inhomogeneous strain fields of high magnitude in the tissue bulk, initiating mechanical and structural alterations. The range of the strain reliably observed by OCE varied from ±10−3 to ±0.4 for diluted and pure glycerol, correspondingly. The OCE-technique used made it possible to reveal previously inaccessible details of the complex spatio-temporal evolution of alternating-sign osmotic strains at the initial stages of agent diffusion. Qualitatively different effects produced by particular hydrophilic OCAs, such as glycerol and iohexol, are discussed, as well as concentration-dependent differences. Overall, the work demonstrates the unique abilities of the new OCE-modality in providing a deeper insight in real-time kinetics of osmotically-induced strains relevant to a broad range of biomedical applications.
Structure and Properties of Gas-Nitrided, Precipitation-Hardened Martensitic Stainless Steel
Authors: Kochmański Paweł , Długozima Marcin , Baranowska Jolanta
Published: January 2022

Nanoflex stainless steel is a promising material for medical applications. However, improvement of its mechanical properties without compromising its corrosion resistance is still a challenge. In order to investigate the effect of the nitriding process on the corrosion and wear resistance of Sandvik NanoflexTM steel, a number of processes were carried out in a gas atmosphere with differing ammonia contents in the temperature range of 425–475 °C for 4 h. The mechanical properties and wear resistance of the layers were tested using the nanoindentation and pin-on-disc methods, respectively. In order to assess corrosion resistance, potentiodynamic tests were carried out in Ringer’s artificial body fluid and in a 3% aqueous solution of sodium chloride. The results are discussed herein with respect to the microstructural characteristics of the layers studied using light and scanning electron microscopy, X-ray diffraction phase analysis and wavelength dispersive X-ray microanalysis. The structure of nitrided layers included three zones: the subsurface zone composed of nitrides and the zones composed of metastable phases, i.e., the S phase (γN) and expanded martensite (αN) with possible precipitates of nitrides. The third zone adjacent to the steel core was enriched with carbon. The nitrided samples showed significant improvement in the wear rate while maintaining good corrosion resistance in comparison to the non-treated steel. We concluded that nitriding should be carried out at a temperature below 450 °C and in an atmosphere containing no more than approximately 50% ammonia in order to avoid nitrides precipitation.
A Multilayer Paste Based on Ag Nanoparticles with Cu@Sn for Die Attachment in Power Device Packaging
Authors: Wang Jintao , Wang Xinjie , Zhang Lin , Zhang Luobin , Duan Fangcheng , Wang Fengyi , Zhang Weiwei , Wang Jianqiang , Zhang Zheng , Hang Chunjin , Chen Hongtao
Published: January 2022

A 3–5 μm Cu@Sn core-shell powder was prepared by chemical plating. Based on the mixture of this Cu@Sn and Ag NPs (nanoparticles), a soldering material for third-generation semiconductors was prepared. The joints prepared with this soldering material had a shear strength of over 40 MPa at 25 °C. This joint did not fail after more than 600 thermal cycles from −40 °C to 140 °C. The special feature of this joint is that the energy potential difference between nanoparticles and micron particles generated in the surface force field during reflow promoted the surface pre-melting of the particles by releasing the excess energy. By this mechanism, it was possible to reduce the porosity of the sintered layer. At the same time, due to the high surface activity energy of nano-silver, the diffusion of the Sn atoms was promoted, further enhancing the bond strength.
Evaluation on Improvement Effect of Different Anti-Stripping Agents on Pavement Performance of Granite–Asphalt Mixture
Authors: Ye Yali , Hao Yan , Zhuang Chuanyi , Shu Shiqi , Lv Fengli
Published: January 2022

There are abundant granite reserves in China, but the adhesion between granite and asphalt is poor, and there are problems such as insufficient water stability, which seriously restrict the application and promotion of granite in asphalt pavement. In order to improve the adhesion between granite and asphalt, as well as the water stability of asphalt mixture, amines and polymers were selected as anti-stripping agents. First, silane coupling agent modified asphalt (SCAMA), rock asphalt modified asphalt (RMA), SBS modified asphalt (SBS), and double rock composite modified asphalt (SCA&RMA) were produced; the modification effect of different anti-stripping modified asphalts was evaluated. Then, the adhesion of different types of asphalts and granite aggregates before and after aging was evaluated by time-delayed water immersion method. Finally, AC-10 and AC-16 granite–asphalt mixtures were designed, through indoor performance test and 1/3 scale accelerated loading test, evaluating the improvement effect of granite–asphalt mixture on pavement performance. The results show that the asphalt modified by amine or organic polymers anti-stripping agent could significantly improve the adhesion between granite and asphalt. The Hamburg wheel-tracking test failed to fully reflect the whole process of high-temperature rutting failure. When evaluating the high-temperature performance and water stability of asphalt mixtures, it is recommended that the evaluation method should cover the whole failure stage of asphalt mixtures; considering the coupling effect of water and high temperature, the order of water stability of granite–asphalt mixture is proposed as follows: SCA&RMA > RMA > SBS > SCAMA > 70-A, and SCA&RMA has the best modification effect.
Effect of Intermetallics and Drill Materials on the Machinability of Al-Si Cast Alloys
Authors: Zedan Yasser , Garza-Elizondo Guillermo H. , Tash Mahmoud , Samuel Agnes M. , Doty Herbert W. , Songmene Victor , Samuel Fawzy Hosny
Published: January 2022

The present study was conducted on the machinability of 396 alloy (containing approximately 11% Si) and B319.2 alloy mainly to emphasize the effects of Fe-intermetallics, i.e., α-Fe, β-Fe, and sludge. The results demonstrate that the presence of sludge in the form of hard spots has a significant effect on cutting forces and tool life, in that it decreases drill life by 50% compared to the base alloy. The formation of the α-Fe phase in the M1 base alloy has a beneficial effect on tool life in that this alloy produces the highest number of holes drilled compared to alloys containing sludge or β-Fe; this result may be explained by the fact that the formation of the α-Fe intermetallic, with its rounded Chinese script morphology and its presence within α-Al dendrites, is expected to improve matrix homogeneity via hardening of the soft α-Al dendrites. Increasing the Fe-content from 0.5% to 1% in the 396-T6 alloy containing 0.5% Mn produces a distinct improvement in alloy machinability in terms of cutting force and tool life. The addition of Fe and/or Mn appears to have no discernible effect on the build-up edge area (BUE) and chip shape.
Synthesis and Applications of Graphene Oxide
Authors: Jiříčková Adéla , Jankovský Ondřej , Sofer Zdeněk , Sedmidubský David
Published: January 2022

Thanks to the unique properties of graphite oxides and graphene oxide (GO), this material has become one of the most promising materials that are widely studied. Graphene oxide is not only a precursor for the synthesis of thermally or chemically reduced graphene: researchers revealed a huge amount of unique optical, electronic, and chemical properties of graphene oxide for many different applications. In this review, we focus on the structure and characterization of GO, graphene derivatives prepared from GO and GO applications. We describe GO utilization in environmental applications, medical and biological applications, freestanding membranes, and various composite systems.
Determining Ricocheting Projectiles’ Temperature Using Numerical and Experimental Approaches
Authors: Badurowicz Przemysław , Pacek Dawid
Published: January 2022

This paper describes the process of creating a numerical FEM (finite element method) model of the 5.56 × 45 mm SS109 projectile. The model was used to calculate the temperatures occurring in the projectile materials during the impact on the steel plate at an angle of 45°. The purpose of the investigation is to estimate the ability of a ricocheting projectile to cause ignition. For the same projectile, experimental tests were also carried out under the conditions adopted for the numerical investigation in order to validate the FEM model. During the experiment, temperature was measured with a thermal camera; the phenomenon was also recorded with a colour high-speed camera.
2D/1D MXene/MWCNT Hybrid Membrane-Based Evaporator for Solar Desalination
Authors: Yang Yawei , Han Yan , Zhao Jianqiu , Que Wenxiu
Published: January 2022

Solar vapor generation through evaporation using photothermal materials is a promising candidate for seawater desalination. The Ti3C2 MXene membrane has exhibited photothermal behavior in solar water evaporation. However, dense packed two-dimensional (2D) MXene membrane with high reflection loss and insufficient vapor escape channels limited its solar evaporation performance. In this work, one-dimensional (1D) multi-walled carbon nanotubes (MWCNT) were added into 2D Ti3C2 nanosheets as the holder to form a 2D/1D hybrid photothermal membrane. Owing to the 2D/1D hybrid structure, more effective broadband solar absorption, water transportation and vapor escape were achieved.
Influence of Selected Ophthalmic Fluids on the Wettability and Hydration of Hydrogel and Silicone Hydrogel Contact Lenses—In Vitro Study
Authors: Chwalik-Pilszyk Gabriela , Wiśniewska Anna
Published: January 2022

This study attempts to evaluate the effect of incubation in selected ophthalmic fluids on contact lenses (Etafilcon A, Omafilcon A, Narafilcon A, Senofilcon A). Four research groups differing in the incubation environment were created: (1) initial state, (2) contact lens solution (CLS), (3) contact lens solution and eye drops (ED) and (4) eye drops. Dehydration by gravimetric method and the contact angle (CA) by the sessile drop method were tested. The surface free energy (SFE) was also calculated with the use of several methods: Owens–Wendt, Wu, Neumann, and Neumann–Kwok. The greatest changes in the dehydration profile were observed for contact lenses incubated in ED. The most noticeable changes in CA values were observed for contact lenses incubated in ED, in which it was not possible to settle water drop after incubation. On the basis of SFE analysis, higher values were found for hydrogel contact lenses, e.g., according to the Owens–Wendt method, they ranged from 54.45 ± 6.56 mJ/m2 to 58.09 ± 4.86 mJ/m2, while in the case of silicone-hydrogel contact lenses, they ranged from 32.86 ± 3.47 mJ/m2 to 35.33 ± 6.56 mJ/m2. Incubation in all tested environments decreased the SFE values, but the differences were in most cases statistically insignificant. Calculating the SFE may be a useful method as it can be used to estimate the possibility of bacteria adhering to contact lens surfaces.
Structural, Electrical, and Mechanical Properties Investigation of Open-Cell Aluminum Foams Obtained by Spark Plasma Sintering and Replication on Polyurethane Template
Authors: Kosenko Alexandra , Pushnitsa Konstantin , Kim Artem , Novikov Pavel , Popovich Anatoliy A.
Published: January 2022

The present paper illustrates a comparison of open-cell aluminum foams. The foams were fabricated by two different methods: spark plasma sintering and replication on a polyurethane template. The influence of pressure, temperature, and diameter of space holding material on foam obtained by the spark plasma sintering method was investigated. Additionally, the aluminum powder content in slurry and atmosphere during thermal processing of foam prepared by the replication technique were studied. The morphology and structure of obtained samples were analyzed by scanning electron microscopy and X-ray diffraction analysis. Supplementarily, mechanical properties and electrical conductivity were studied. The porosity of obtained samples was 83% for the SPS sample and 85% for the replication sample. The results of the studies carried out gave us an understanding that the SPS method is more promising for using the obtained foams as cathode current collectors in lithium-ion batteries due to excessive aluminum oxidation during sintering in the furnace.
Synthesis and Characterization of Calcium Phosphate Materials Derived from Eggshells from Different Poultry with and without the Eggshell Membrane
Authors: Kalbarczyk Marta , Szcześ Aleksandra , Kantor Izolda , May Zoltan , Sternik Dariusz
Published: January 2022

Calcium phosphate materials such as hydroxyapatite (HA) or tricalcium phosphate (β-TCP) are highly attractive due to their multitude of applications in bone replacement as well as their environmental and ecological credentials. In this research, quail, hen, duck, and pigeon eggshells were used as a calcium source to obtain calcium phosphate materials via the environmentally friendly wet synthesis. Using the eggshells with the organic membrane, the biphasic calcium phosphate materials composed mainly of HA were obtained. The second mineral phase was β-TCP in the case of using quail, hen, and pigeon eggshells and octacalcium phosphate (OCP) in the case of duck eggshells. The HA content in the obtained materials depended on the amount of membrane in the eggshells and decreased in the order of pigeon, duck, hen, and quail eggshells. The eggshell membrane removal from the eggshells caused the reduced content of HA and the presence of the more soluble β-TCP or OCP phase in the obtained materials. The calcium ions release profile in the PBS buffer indicates the potential biomedical application of these materials.
Vacuum Brazing of Metallized YSZ and Crofer Alloy Using 72Ag-28Cu Filler Foil
Authors: Huang Liang-Wei , Shiue Ren-Kae , Liu Chien-Kuo , Cheng Yung-Neng , Lee Ruey-Yi , Tsay Leu-Wen
Published: January 2022

The study focused on dissimilar brazing of metallized YSZ (Yttria-Stabilized Zirconia) and Crofer alloy using BAg-8 (72Ag-28Cu, wt%) filler foil. The YSZ substrate was metallized by sequentially sputtering Ti (0.5/1 μm), Cu (1/3 μm), and Ag (1.5/5 μm) layers, and the Crofer substrate was coated with Ag layers with a thickness of 1.5 and 5 μm, respectively. The BAg-8 filler demonstrated excellent wettability on both metallized YSZ and Crofer substrates. The brazed joint primarily consisted of Ag-Cu eutectic. The metallized Ti layer dissolved into the braze melt, and the Ti preferentially reacted with YSZ and Fe from the Crofer substrate. The globular Fe2Ti intermetallic compound was observed on the YSZ side of the joint. The interfacial reaction of Ti was increased when the thickness of the metallized Ti layer was increased from 0.5 to 1 μm. Both brazed joints were crack free, and no pressure drop was detected after testing at room temperature for 24 h. In the YSZ/Ti(0.5μ)/Cu(1μ)/Ag(1.5μ)/BAg-8(50μ)/Ag(1.5μ)/Crofer joint tested at 600 °C, the pressure of helium decreased from 2.01 to 1.91 psig. In contrast, the helium pressure of the YSZ/Ti(1μ)/Cu(3μ)/Ag(5μ)/BAg-8(50μ)/Ag(5μ)/Crofer joint slightly decreased from 2.02 to 1.98 psig during the cooling cycle of the test. The greater interfacial reaction between the metallized YSZ and BAg-8 filler due to the thicker metallized Ti layer on the YSZ substrate was responsible for the improved gas-tight performance of the joint.
Strain Rate-Dependent Compressive Properties of Bulk Cylindrical 3D-Printed Samples from 316L Stainless Steel
Authors: Neuhäuserová Michaela , Koudelka Petr , Fíla Tomáš , Falta Jan , Rada Václav , Šleichrt Jan , Zlámal Petr , Mauko Anja , Jiroušek Ondřej
Published: January 2022

The main aim of the study was to analyse the strain rate sensitivity of the compressive deformation response in bulk 3D-printed samples from 316L stainless steel according to the printing orientation. The laser powder bed fusion (LPBF) method of metal additive manufacturing was utilised for the production of the samples with three different printing orientations: 0∘, 45∘, and 90∘. The specimens were experimentally investigated during uni-axial quasi-static and dynamic loading. A split Hopkinson pressure bar (SHPB) apparatus was used for the dynamic experiments. The experiments were observed using a high-resolution (quasi-static loading) or a high-speed visible-light camera and a high-speed thermographic camera (dynamic loading) to allow for the quantitative and qualitative analysis of the deformation processes. Digital image correlation (DIC) software was used for the evaluation of displacement fields. To assess the deformation behaviour of the 3D-printed bulk samples and strain rate related properties, an analysis of the true stress–true strain diagrams from quasi-static and dynamic experiments as well as the thermograms captured during the dynamic loading was performed. The results revealed a strong strain rate effect on the mechanical response of the investigated material. Furthermore, a dependency of the strain-rate sensitivity on the printing orientation was identified.
Production and Properties of the Porous Layer Obtained by the Electrochemical Method on the Surface of Austenitic Steel
Authors: Ossowska Agnieszka , Ryl Jacek , Sternicki Tomasz
Published: January 2022

The growing demand for implants has seen increasing interest in the introduction of new technologies and surface modification methods of metal biomaterials. This research aimed to produce and characterize a porous layer grown on austenitic stainless steel 316L, obtained via the anodization process near the micro-arc oxidation, i.e., low voltage micro-arc oxidation (LVMAO). The discussed layer significantly influences the properties of metallic biomedical materials. The surface topography, layer thickness, surface roughness, pore diameter, elemental composition, crystal structure, and surface wettability were assessed for all anodized layers, together with the resultant corrosion resistance. Attention was paid to the influence of the process parameters that affect the specification of the produced layer. The obtained results showed surface development and different sized pores in the modified layers, as well as an increase in corrosion resistance in the Ringer’s solution.
Synthesis, Characterization, and Photocatalytic Activity of Ba-Doped BiFeO3 Thin Films
Authors: Abdelmadjid Khiat , Gheorghiu Felicia , Abderrahmane Boughelout
Published: January 2022

In the present paper, Bi1−xBaxFeO3 (BBFO) thin films (where x = 0, 0.02 and 0.05) were prepared by a combined sol-gel and spin-coating method. The influence of Ba substitutions on the structural, microstructural, optical properties, and photocatalytic activity of BiFeO3 thin films has been studied. X-ray diffraction pattern correlated with FTIR analysis results confirms that all the films have a perovskite structure of rhombohedral symmetry with an R3m space group. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to investigate the surface morphology and reveals microstructural modifications with the increase in Ba concentration. The optical properties show that the band gap is narrowed after doping with Ba ions and decreases gradually with the increase of doping content. The photocatalytic investigations of deposited films revealed that Ba doping of BFO material leads to the enhancement of photocatalytic response. The present data demonstrates that Bi1−xBaxFeO3 (BBFO) thin films can be used in photocatalytic applications.
On Testing the Adequacy of the Inverse Gaussian Distribution
Authors: Allison James , Betsch Steffen , Ebner Bruno , Visagie Jaco
Published: January 2022

We propose a new class of goodness-of-fit tests for the inverse Gaussian distribution based on a characterization of the cumulative distribution function (CDF). The new tests are of weighted L2-type depending on a tuning parameter. We develop the asymptotic theory under the null hypothesis and under a broad class of alternative distributions. These results guarantee that the parametric bootstrap procedure, which we employ to implement the test, is asymptotically valid and that the whole test procedure is consistent. A comparative simulation study for finite sample sizes shows that the new procedure is competitive to classical and recent tests, outperforming these other methods almost uniformly over a large set of alternative distributions. The use of the newly proposed test is illustrated with two observed data sets.
Theoretical Study of the Static and Dynamic Characteristics of a Slotted Adaptive Hydrostatic Thrust Bearing with a Regulator of the Lubricant Output Flow
Authors: Kodnyanko Vladimir , Kurzakov Andrey , Surovtsev Alexey , Strok Lilia , Grigorieva Olga , Brungardt Maxim , Belyakova Svetlana , Gogol Ludmila
Published: January 2022

This manuscript considers the design of a slotted adaptive hydrostatic thrust bearing with a regulator of the lubricant output flow. A theoretical study of its static and dynamic characteristics was carried out. The aim of the study was to test the reliability of the hypothesis concerning the possibility of obtaining a stable-to-oscillation adaptive thrust bearing of negative compliance, avoiding the need for a complex system of external combined throttling by replacing it with a simple slotted throttle. Mathematical modeling of the thrust bearing movement was carried out. The possibility of reducing the compliance to negative values is shown, providing the bearing with an adaptive function, consisting of using the structure as a bearing and as an active deformation compensator of the elastic system of a metal-cutting machine in order to improve the quality of the metalwork. Analysis of load static characteristics showed that negative compliance is provided over a wide range of loads, which can be up to 75% or more of the range of permissible bearing loads. Based on the study of dynamic characteristics, it was concluded that with a targeted selection of parameters that have a major effect on the dynamics of the structure, the considered adaptive hydrostatic thrust bearing can attain a very high quality of dynamics. It is shown that the viscous damping of the lubricating film enclosed in the gaps and the damping of the material of the elastic ring of the regulator are important resources for ensuring the optimal dynamics of the thrust bearing.
Chitosan Oligosaccharides Alleviate Colitis by Regulating Intestinal Microbiota and PPARγ/SIRT1-Mediated NF-κB Pathway
Authors: Guo Congcong , Zhang Yue , Ling Tao , Zhao Chongjie , Li Yanru , Geng Meng , Gai Sailun , Qi Wei , Luo Xuegang , Chen Liehuan , Zhang Tongcun , Wang Nan
Published: January 2022

Chitosan oligosaccharides (COS) have been shown to have potential protective effects against colitis, but the mechanism underlying this effect has not been fully elucidated. In this study, COS were found to significantly attenuate dextran sodium sulfate-induced colitis in mice by decreasing disease activity index scores, downregulating pro-inflammatory cytokines, and upregulating Mucin-2 levels. COS also significantly inhibited the levels of nitric oxide (NO) and IL-6 in lipopolysaccharide-stimulated RAW 264.7 cells. Importantly, COS inhibited the activation of the NF-κB signaling pathway via activating PPARγ and SIRT1, thus reducing the production of NO and IL-6. The antagonist of PPARγ could abolish the anti-inflammatory effects of COS in LPS-treated cells. COS also activated SIRT1 to reduce the acetylation of p65 protein at lysine 310, which was reversed by silencing SIRT1 by siRNA. Moreover, COS treatment increased the diversity of intestinal microbiota and partly restored the Firmicutes/Bacteroidetes ratio. COS administration could optimize intestinal microbiota composition by increasing the abundance of norank_f_Muribaculaceae, Lactobacillus and Alistipes, while decreasing the abundance of Turicibacte. Furthermore, COS could also increase the levels of propionate and butyrate. Overall, COS can improve colitis by regulating intestinal microbiota and the PPARγ/SIRT1-mediated NF-κB pathway.
Effect of Fucoidan on the Mitochondrial Membrane Potential (ΔΨm) of Leukocytes from Patients with Active COVID-19 and Subjects That Recovered from SARS-CoV-2 Infection
Authors: Díaz-Resendiz Karina Janice Guadalupe , Covantes-Rosales Carlos Eduardo , Benítez-Trinidad Alma Betsaida , Navidad-Murrieta Migdalia Sarahy , Razura-Carmona Francisco Fabian , Carrillo-Cruz Christian Daniel , Frias-Delgadillo Edwin Jaime , Pérez-Díaz Daniela Alejandra , Díaz-Benavides Matxil Violeta , Zambrano-Soria Mercedes , Ventura-Ramón Guadalupe Herminia , Romero-Castro Aurelio , Alam-Escamilla David , Girón-Pérez Manuel Iván
Published: January 2022

Fucoidan is a polysaccharide obtained from marine brown algae, with anti-inflammatory, anti-viral, and immune-enhancing properties, thus, fucoidan may be used as an alternative treatment (complementary to prescribed medical therapy) for COVID-19 recovery. This work aimed to determine the ex-vivo effects of treatment with fucoidan (20 µg/mL) on mitochondrial membrane potential (ΔΨm, using a cationic cyanine dye, 3,3′-dihexyloxacarbocyanine iodide (DiOC6(3)) on human peripheral blood mononuclear cells (HPBMC) isolated from healthy control (HC) subjects, COVID-19 patients (C-19), and subjects that recently recovered from COVID-19 (R1, 40 ± 13 days after infection). In addition, ex-vivo treatment with fucoidan (20 and 50 µg/mL) was evaluated on ΔΨm loss induced by carbonyl cyanide 3-chlorophenylhydrazone (CCCP, 150 µM) in HPBMC isolated from healthy subjects (H) and recovered subjects at 11 months post-COVID-19 (R2, 335 ± 20 days after infection). Data indicate that SARS-CoV-2 infection induces HPBMC loss of ΔΨm, even 11 months after infection, however, fucoidan promotes recovery of ΔΨm in PBMCs from COVID-19 recovered subjects. Therefore, fucoidan may be a potential treatment to diminish long-term sequelae from COVID-19, using mitochondria as a therapeutic target for the recovery of cellular homeostasis.
Production of Lectins from Marine Algae: Current Status, Challenges, and Opportunities for Non-Destructive Extraction
Authors: Maliki Intan Mariana , Misson Mailin , Teoh Peik Lin , Rodrigues Kenneth Francis , Yong Wilson Thau Lym
Published: January 2022

Marine algae are an excellent source of novel lectins. The isolation of lectins from marine algae expands the diversity in structure and carbohydrate specificities of lectins isolated from other sources. Marine algal lectins have been reported to have antiviral, antitumor, and antibacterial activity. Lectins are typically isolated from marine algae by grinding the algal tissue with liquid nitrogen and extracting with buffer and alcohol. While this method produces higher yields, it may not be sustainable for large-scale production, because a large amount of biomass is required to produce a minute amount of compound, and a significant amount of waste is generated during the extraction process. Therefore, non-destructive extraction using algal culture water could be used to ensure a continuous supply of lectins without exclusively disrupting the marine algae. This review discusses the traditional and recent advancements in algal lectin extraction methods over the last decade, as well as the steps required for large-scale production. The challenges and prospects of various extraction methods (destructive and non-destructive) are also discussed.
Moderating Effect of Burnout on the Relationship between Self-Efficacy and Job Performance among Psychiatric Nurses for COVID-19 in National Hospitals
Authors: Lim Seongmi , Song Youngok , Nam Yoonyoung , Lee Youngmoon , Kim Duckjin
Published: January 2022

Background and Objective: The unprecedented spread of infectious diseases, such as the COVID-19 pandemic, in psychiatric units has affected the self-efficacy, burnout, and job performances of psychiatric nurses. We conducted a survey to investigate the moderating effect of burnout on the relationship between the self-efficacy and job performances of psychiatric nurses. Materials and Methods: Validated and structured questionnaires were used to collect data from 186 nurses in psychiatric units for COVID-19. The data were analyzed using descriptive statistics, Pearson’s correlation coefficient, and a series of multiple linear regression analyses based on Baron and Kenny’s method using the SPSS 26.0 program. Results: Job performance was positively correlated with self-efficacy (r = 0.75, p < 0.001) but had no significant correlation with burnout (r = −0.11, p = 0.150). Self-efficacy was negatively correlated with burnout (r = −0.22, p = 0.002). Burnout among psychiatric nurses had significant moderating effects on self-efficacy and job performance (β = −0.11, p = 0.024). Conclusions: These findings indicate a need to prevent burnout and to enhance self-efficacy in psychiatric nurses to increase their job performances and serve as a basis for establishing strategies to deploy medical staff in the future.
Acinar Atrophy, Fibrosis and Fatty Changes Are Significantly More Common than Sjogren’s Syndrome in Minor Salivary Gland Biopsies
Authors: Klein Ainat , Klein Jonathan , Chacham Moran , Kleinman Shlomi , Shuster Amir , Peleg Oren , Ianculovici Clariel , Kaplan Ilana
Published: January 2022

Background and Objective: Hyposalivation and xerostomia can result from a variety of conditions. Diagnosis is based on a combination of medical history, clinical and serological parameters, imaging, and minor salivary gland biopsy when indicated. The Objective was to characterize microscopic changes in minor salivary gland biopsies taken in patients with xerostomia. Materials and Methods: 10-year retrospective analysis of minor salivary gland biopsies, 2007–2017. Histomorphometric analysis included gland architecture, fibrosis, fat replacement, inflammation and stains for IgG/IgG4, when relevant. Results: 64 consecutive biopsies, of which 54 had sufficient tissue for diagnosis of Sjogren’s Syndrome (SS) were included (18 males, 46 females, average age 56 (±12.5) years). Only 12 (22.2%) were microscopically consistent with SS, none stained for IgG4. Medical conditions were recorded in 40 (63%), most frequently hypertension and hyperlipidemia (28% each). Medications were used by 45 (70%), of which in 50% more than one. Xerostomia in non-SS cases was supported by abnormal gland morphology, including acinar atrophy, fibrosis and fatty replacement. All morphological abnormalities are correlated with age, while fatty replacement correlated with abnormal lipid metabolism. Multiple medications correlated with microscopic features which did not correspond with SS. Conclusions: SS was confirmed in a minority of cases, while in the majority fatty replacement, fibrosis and multiple medications can explain xerostomia, and are related to aging and medical conditions. Medical history and auxiliary tests could lead to correct diagnosis in non-SS patients, avoiding biopsy. The necessity of a diagnostic biopsy should be given serious consideration only after all other diagnostic modalities have been employed.
The Relationship between MALAT1 Polymorphism rs3200401 C > T and the Risk of Overall Cancer: A Meta-Analysis
Authors: Li Keming , Han Zhuo , Wu Jinyu , Ye Hua , Sun Guiying , Shi Jianxiang , Zhang Jianying , Wang Peng
Published: January 2022

Background and Objectives: At present, the association between the long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) polymorphism rs3200401 C > T and cancer risk remain controversial. The aim of this meta-analysis was to assess the association between rs3200401 C > T and cancer susceptibility. Materials and Methods: The databases of PubMed, EMBASE and Web of Science were searched for literature published in English until 1 September 2021. The odd ratios (ORs) and 95% confidence intervals (CIs) were applied to evaluate the strength of association in five genetic models. Heterogeneity was assessed using the Q-test and I2 test. Begg’s funnel plot and Egger’s linear regression test were conducted to assess publication bias. Meta-regression analysis was used to explore potential sources of heterogeneity. Trial sequential analysis (TSA) was performed to validate the reliability of the results. Results: A total of 10 case–control studies involving 6630 cases and 7457 controls were included in this study. The pooled ORs showed no significant association between MALAT1 rs3200401 C > T and cancer risk in five genetic models. Similarly, the association was not found in the subgroups of control source, ethnicity and study quality. In the cancer type subgroup, the results demonstrated that the T allele increased the risk of colorectal cancer (CRC) compared with the C allele. (C vs. T: OR, 1.16; 95% CI, 1.01–1.33). Conclusion: In the current meta-analysis, we found no significant association between MALAT1 polymorphism rs3200401 C > T and overall cancer risk. However, the rs3200401 C > T may be linked to a higher risk of CRC, which needs more studies to be further confirmed.
In-Hospital and Long-Term Outcomes in Patients with Head and Neck Cancer Bleeding
Authors: Yen Chieh-Ching , Ho Che-Fang , Wu Chia-Chien , Tsao Yu-Ning , Chaou Chung-Hsien , Chen Shou-Yen , Ng Chip-Jin , Yeh Heng
Published: January 2022

Background and Objectives: The purpose of the present study was to elucidate the in-hospital and long-term outcomes of patients with head and neck cancer (HNC) bleeding and to analyze the risk factors for mortality. Materials and Methods: We included patients who presented to the emergency department (ED) with HNC bleeding. Variables of patients who survived and died were compared and associated factors were investigated by logistic regression and Cox’s proportional hazard model. Results: A total of 125 patients were enrolled in the present study. Fifty-nine (52.8%) patients experienced a recurrent bleeding event. The in-hospital mortality rate was 16%. The overall survival at 1, 3 and 5 years was 48%, 41% and 34%, respectively. The median survival time was 9.2 months. Multivariate logistic regression analyses revealed that risk factors for in-hospital mortality were inotropic support (OR = 10.41; Cl 1.81–59.84; p = 0.009), hypopharyngeal cancer (OR = 4.32; Cl 1.29–14.46; p = 0.018), and M stage (OR = 5.90; Cl 1.07–32.70; p = 0.042). Multivariate Cox regression analyses indicate that heart rate >110 (beats/min) (HR = 2.02; Cl 1.16–3.51; p = 0.013), inotropic support (HR = 3.25; Cl 1.20–8.82; p = 0.021), and hypopharygneal cancer (HR = 2.22; Cl 1.21–4.06; p = 0.010) were all significant independent predictors of poorer overall survival. Conclusions: HNC bleeding commonly represents the advanced disease stage. Recognition of associated factors aids in the risk stratification of patients with HNC bleeding.
Brain-Derived Neurotrophic Factor Levels in Cord Blood from Growth Restricted Fetuses with Doppler Alteration Compared to Adequate for Gestational Age Fetuses
Authors: Pascual-Mancho Jara , Pintado-Recarte Pilar , Morales-Camino Jorge C. , Romero-Román Carlos , Hernández-Martin Concepción , Bravo Coral , Bujan Julia , Alvarez-Mon Melchor , Ortega Miguel A. , De León-Luis Juan
Published: January 2022

Background and Objectives: Fetal growth restriction (FGR) is a severe obstetric disease characterized by a low fetal size entailing a set of undesired consequences. For instance, previous studies have noticed a worrisome association between FGR with an abnormal neurodevelopment. However, the precise link between FGR and neurodevelopmental alterations are not yet fully understood yet. Brain-derived neurotrophic factor (BDNF) is a critical neurotrophin strongly implicated in neurodevelopmental and other neurological processes. In addition, serum levels of BDNF appears to be an interesting indicator of pathological pregnancies, being correlated with the neonatal brain levels. Therefore, the aim of this study is to analyze the blood levels of BDNF in the cord blood from fetuses with FGR in comparison to those with weight appropriate for gestational age (AGA). Materials and Methods: In this study, 130 subjects were recruited: 91 in group A (AGA fetuses); 39 in group B (16 FGR fetuses with exclusively middle cerebral artery (MCA) pulsatility index (PI) < 5th percentile and 23 with umbilical artery (UA) PI > 95th percentile). Serum levels of BDNF were determined through ELISA reactions in these groups. Results: Our results show a significant decrease in cord blood levels of BDNF in FGR and more prominently in those with UA PI >95th percentile in comparison to AGA. FGR fetuses with exclusively decreased MCA PI below the 5th percentile also show reduced levels of BDNF than AGA, although this difference was not statistically significant. Conclusions: Overall, our study reports a potential pathophysiological link between reduced levels of BDNF and neurodevelopmental alterations in fetuses with FGR. However, further studies should be conducted in those FGR subjects with MCA PI < 5th percentile in order to understand the possible implications of BDNF in this group.
Vaginal Bipolar Radiofrequency Treatment of Mild SUI: A Pilot Retrospective Study
Authors: Mezzana Paolo , Garibay Ignacio , Fusco Irene
Published: January 2022

Background and Objectives: This retrospective study investigates the action of a bipolar, temperature controlled, endovaginal RF handpiece for the treatment of mild, moderate, and severe stress urinary incontinence with a minimally invasive approach. Stress urinary incontinence (SUI) is a common condition resulting in involuntary urine leakage, with an associated social and psychological impact. SUI is the most common type of urinary incontinence in women. Materials and Methods: We retrospectively studied 54 patients for this study. The bipolar radiofrequency energy used in all patients was 50 W, with temperatures maintained between 41 °C and 44 °C. Two sessions were performed four weeks apart. In order to monitor all patients before the first treatment and 4 months after the second treatment, the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) was used. Paired Student’s t test was used to elaborate the statistical data. Results: The average frequency of urine leak improved from “2–3 times a week” (2.1 ± 1.3 points before the treatment) to “once a week” (0.8 ± 1.3 points 4 MFU post-treatment). The average volume improved from “small/moderate quantity” (3.2 ± 1.6 points before the treatment) to “none” (0.9 ± 1.4 points 4 MFU post-treatment). No adverse events or side effects were found. Conclusion: Our preliminary results represent a good starting point to check the effectiveness and validity of the bipolar radiofrequency temperature-controlled method in the treatment of SUI.
Simulation Study of Chain-like Body Translocation through Conical Pores in Thick Membranes
Authors: Domański Zbigniew , Grzybowski Andrzej Z.
Published: January 2022

Artificial membranes with conical pores and controllable thickness reveal ionic-transport capabilities that are superior compared with those offered by cylindrical pores. By simulating the translocation of an abstract chain-like body through a conical pore in a membrane with a variable thickness, we formulate a statistical model of the translocation time τ. Our rough model encodes the biochemical details of a given real chain-like molecule as evolving sequences of the allowed chain-like body’s conformations. In our simulation experiments, we focus primarily on pore geometry and kinetic aspects of the translocation process. We study the impact of the membrane thickness L, and both conical-pore diameters ϕcis,ϕtrans on the probability distribution of τ. We have found that for all considered simulation setups, the randomness of τ is accurately described by the family of Moyal distributions while its expected value τ is proportional to Lξ, with ξ being dependent on ϕcis,ϕtrans.
Influence of Solute Size on Membrane Fouling during Polysaccharide Enrichment Using Dense Polymeric UF Membrane: Measurements and Mechanisms
Authors: Kim Pooreum , Kim Hyungsoo , Oh Heekyong , Kang Joon-seok , Lee Sangyoup , Park Kitae
Published: January 2022

Fouling mechanisms associated with membrane-based polysaccharide enrichment were determined using a dense ultrafiltration (UF) membrane. Dextran with different molecular weights (MWs) was used as a surrogate for polysaccharides. The influence of dextran MW on fouling mechanisms was quantified using the Hermia model. Flux data obtained with different dextran MWs and filtration cycles were plotted to quantify the more appropriate fouling mechanisms among complete pore blocking, standard pore blocking, intermediate pore blocking, and cake filtration. For 100,000 Da dextran, all four mechanisms contributed to the initial fouling. As the filtration progressed, the dominant fouling mechanism appeared to be cake filtration with a regression coefficient (R2) of approximately 0.9519. For 10,000 Da, the R2 value for cake filtration was about 0.8767 in the initial filtration. Then, the R2 value gradually decreased as the filtration progressed. For 6000 Da, the R2 values of the four mechanisms were very low in the initial filtration. However, as the filtration progressed, the R2 value for cake filtration reached 0.9057. These results clearly show that the fouling mechanism of dense UF membranes during polysaccharide enrichment can be quantified. In addition, it was confirmed that the dominant fouling mechanism can change with the size of the polysaccharide and the duration of filtration.
Impact of Polymer Membrane Properties on the Removal of Pharmaceuticals
Authors: Żyłła Renata , Foszpańczyk Magdalena , Kamińska Irena , Kudzin Marcin , Balcerzak Jacek , Ledakowicz Stanisław
Published: January 2022

The influence of various factors on the removal efficiency of selected pharmaceuticals by membrane filtration was investigated. Several commercial polymer membranes were used for nanofiltration (NF) from various manufacturers. The studies were conducted for ibuprofen (IBF), amoxicillin (AMX), diclofenac (DCF), tetracycline (TRC), salicylic acid (SA) and acetylsalicylic acid (ASA). The influence of the structure and properties of the tested compounds on the retention coefficient and filtration rate was investigated. The influence of pH on the filtration parameters was also checked. The properties of selected membranes influencing the retention of pharmaceuticals and filtrate flux were analysed. An extensive analysis of the retention coefficients dependence on the contact angle and surface free energy was performed. It was found that there is a correlation between the hydrophilicity of the membrane and the effectiveness and efficiency of the membrane. As the contact angle of membrane increased, the flow rate of the filtrate stream increased, while the retention coefficient decreased. The studies showed that the best separation efficiency was achieved for compounds with a molecular weight (MW) greater than 300 g/mol. During the filtration of pharmaceuticals with MW ranging from 300 to 450 g/mol, the type of membrane used practically did not affect the filtration efficiency and a high degree of retention was achieved. In the case of low MW molecules (SA and ASA), a significant decrease in the separation efficiency during the process was noted.
Optimising the Flux Enhancer Dosing Strategy in a Pilot-Scale Anaerobic Membrane Bioreactor by Mathematical Modelling
Authors: Odriozola Magela , van Lier Jules B. , Spanjers Henri
Published: January 2022

Flux enhancers (FEs) have been successfully applied for fouling mitigation in membrane bioreactors. However, more research is needed to compare and optimise different dosing strategies to improve the filtration performance, while minimising the use of FEs and preventing overdosing. Therefore, the goal of this research is to develop an optimised control strategy for FE dosing into an AnMBR by developing a comprehensive integrated mathematical model. The integrated model includes filtration, flocculation, and biochemical processes to predict the effect of FE dosing on sludge filterability and membrane fouling rate in an AnMBR. The biochemical model was based on an ADM1, modified to include FEs and colloidal material. We developed an empirical model for the FE-induced flocculation of colloidal material. Various alternate filtration models from the literature and our own empirical models were implemented, calibrated, and validated; the best alternatives were selected based on model accuracy and capacity of the model to predict the effect of varying sludge characteristics on the corresponding output, that is fouling rate or sludge filterability. The results showed that fouling rate and sludge filterability were satisfactorily predicted by the selected filtration models. The best integrated model was successfully applied in the simulation environment to compare three feedback and two feedforward control tools to manipulate FE dosing to an AnMBR. The modelling results revealed that the most appropriate control tool was a feedback sludge filterability controller that dosed FEs continuously, referred to as ∆R20_10. Compared to the other control tools, application of the ∆R20_10 controller resulted in a more stable sludge filterability and steady fouling rate, when the AnMBR was subject to specific disturbances. The simulation environment developed in this research was shown to be a useful tool to test strategies for dosing flux enhancer into AnMBRs.
Influence of Dialysis Membranes on Clinical Outcomes: From History to Innovation
Authors: Chen Yee-An , Ou Shuo-Ming , Lin Chih-Ching
Published: January 2022

Dialysis membranes were traditionally classified according to their material compositions (i.e., as cellulosic or synthetic) and on the basis of the new concept of the sieving coefficient (determined by the molecular weight retention onset and molecular weight cut-off). The advantages of synthetic polymer membranes over cellulose membranes are also described on the basis of their physical, chemical, and structural properties. Innovations of dialysis membrane in recent years include the development of medium cutoff membranes; graphene oxide membranes; mixed-matrix membranes; bioartificial kidneys; and membranes modified with vitamin E, lipoic acid, and neutrophil elastase inhibitors. The current state of research on these membranes, their effects on clinical outcomes, the advantages and disadvantages of their use, and their potential for clinical use are outlined and described.