Modification Of Function Research Articles

Enhancing soy protein isolate flexibility through non-covalent ferulic acid modification: Implications for interfacial characteristics and protein-based emulsion performance

This study aims to enhance the flexibility of soy protein isolate (SPI) to improve its functional properties, focusing on the investigated the effects of ferulic acid (FA) on the structure, interfacial behaviour and emulsification performance of SPI. Our study showed that FA induces SPI structures to depolymerization and unfolding primarily through hydrogen bonding and hydrophobic interactions, thereby increasing the flexible structures (random coils and β-turns) of protein. These changes enhanced the interfacial functional properties of SPI, with 150 μmol/g of FA-modified SPI exhibiting the best molecular flexibility, and its emulsification and emulsification stability were improved by 21.26 % and 39.86 %, respectively, compared to unmodified SPI. In addition, non-covalently modified FA significantly improved emulsions stability. Emulsions stabilized by SPI-FA150 complexes exhibited better storage, heat, and freeze-thaw stability than SPI, with a significant reduction in oxidation products. This relationship between flexibility and function reveals the importance of structural modification in enhancing protein functionality. These discoveries shed new light on flexible protein processing technologies and the application of FA in protein functional modification.

Effects of Gd2O3 additives on microscopical morphology of ZrB2-SiC sintering ceramic system: Insights for electron transpiration cooling

By manipulating the work function, the dissipation of thermal energy on the material surface can be regulated through Electron Transpiration Cooling (ETC) mechanism. The doping of rare-earth oxide serves as an effective approach for reducing the work function, whereas there is still a lack of comprehensive research into the microstructural morphology of the rare-earth oxides and their correlations with the modifications of the work functions. This study investigates the detailed microscopical structure of Gd2O3 in the ultrahigh-temperature ceramic system (ZrB2-20 vol%SiC). Semi-quantitative composition analyses based on X-ray photoelectron spectra indicate that an increased doping concentration of Gd2O3 is beneficial for the formation of a single solid-state Gd0.18Zr0.82O1.91 phase of ZrB2-SiC system. Atomic-scale scanning transmission electron microscopy (STEM) analyses suggest that Gd2O3 is enriched at the interfaces between SiC and ZrB2 matrix with a nanoscale fibrous morphology composed of alternated Gd2O3 crystals and pores, rendering a continuous microstructure throughout the entire system. This peculiar microstructural morphology is anticipated to facilitate its diffusion along the grain boundary and the formation of Gd2O3 nanolayers at the surface region below the melting points of the ceramic matrix, which can efficiently lower the material work function and reduce the emission energy of the surface electrons during thermal emission through ETC mechanism. The composite with 10 vol% Gd2O3 induces a reduction of the averaged work function of ∼0.49 eV before preforming the thermionic emission experiments. Our results provide valuable insights into the impacts of rare-earth oxide on the ZrB2-SiC matrix, as well as shed light on the feasibility of the ETC mechanism through the efficient design of thermal protection materials.

Antimicrobial Effect of Waterborne Polyurethane-Based Cellulose Nanofibril/Silver Nanoparticles Composites and Acacia concinna (Willd.) DC Extract (Shikakai).

Antimicrobial coatings are becoming increasingly popular in functional material modification and are essential in addressing microbial infection challenges. In this study, the phytochemical and antimicrobial potential of aqueous, 80% methanol and 80% ethanol pod extracts of Acacia concinna (Willd.) DC (AC) and its application in the green in situ (one pot) synthesis of silver nanoparticles on Cellulose nano fibrils (CNF) and Waterborne polyurethane (WPU) were prepared. The phytochemical evaluation of Acacia concinna crude extracts showed the presence of alkaloids, flavonoids, phenols, tannins, terpenoids, saponins, steroids. The surface plasmon Resonance peak of CNF/AC-AgNPs was 450 nm and the FTIR result confirmed functional groups such as carbonyl, phenols and carboxyl were present which was important for the bio-reduction of silver nanoparticles. The crude AC aqueous pods extract against Gram-positive and Gram-negative bacteria compared with AC ethanol and AC methanol extracts. The WPU/CNF/AC-AgNPs composite dispersion was also good in terms of its antibacterial activities. The WPU/CNF/AC-AgNPs nanocomposites could be applied as bifunctional nanofillers as an antimicrobial agent in food packaging systems and other biological applications.

Influence of Surface Roughness on Phosphonation and Wettability of Nanosecond Laser‐Treated Titanium Surfaces

The duplex treatments of metal surfaces combining laser‐assisted functionalization and chemical modification attract a growing interest in view of better control of functional properties such as wettability. Patterned titanium oxides layers of different nature and roughness are produced in ambient atmosphere on a titanium surface using a nanosecond 532 nm Nd:YAG laser. Standalone lines and hatched surfaces obtained with different laser parameters are characterized by scanning electronic microscopy coupled with EDS analysis, micro‐Raman, XRD and X‐ray photoelectron spectroscopy (XPS). A set of surfaces having featureless and saw‐tooth morphologies of different roughnesses is modified with octylphosphonic acid (OPA). The effect of surface roughness on the efficiency of OPA grafting is investigated using XPS. It is found that the organic load on the chemically modified surfaces increases with surface roughness. The apparent thickness of the OPA layers is estimated using a standard uniform overlap model and considering the correction due to the corrugated appearance of the laser‐treated surfaces. The wetting properties of the surfaces before and after chemical modification are compared. The laser‐treated surfaces show superhydrophilic behavior consistent with Wenzel model. On the other hand, the chemically modified surfaces demonstrate a strong increase in hydrophobicity along with the roughness increase, in agreement with the Cassie–Baxter model.

Construction of Carbon Dioxide Responsive Graphene Point Imbibition and Drainage Fluid and Simulation of Imbibition Experiments

The global oil and gas exploration targets are gradually moving towards a new field of oil and gas accumulation with nanopore throats, ranging from millimeter scale to micro-nano pore throats. The development method of tight oil reservoirs is different from that of conventional oil reservoirs, and the development efficiency is constrained. Therefore, it is necessary to construct a nanoscale fluid with strong diffusion and dispersion and improve its permeability, suction, and displacement capabilities. Under the background of CCUS, carbon dioxide flooding is a better way to develop tight reservoirs. However, in order to solve the problem of gas channeling, this paper developed a carbon dioxide-responsive graphene point type surfactant, which has a good gas–liquid synergistic effect. At the same time, graphene nanomaterials are carbon-based and create no environmental damage in oil reservoirs. In this study, graphene quantum dots (GQDs) were prepared using the hydrothermal method, and functional graphene quantum dots (F-GQDs) responsive to carbon dioxide stimulation were synthesized by covalent grafting of amidine functional groups. By characterizing its structure and physical and chemical properties, and by conducting imbibition simulation experiments, its imbibition and drainage ability in nanopore throats is elucidated. Infrared spectrum measurement shows that after functional modification, the quantum dots exhibited new characteristic peaks at 1600 cm−1 to 1300 cm−1, considering the N-H plane-stretching characteristic peak. The fluorescence spectra showed that the fluorescence intensity of F-GQDs was increased after functional modification, which indicated that F-GQDs were successfully synthesized. Through measurements of interfacial activity and adhesion work calculations, the oil–water interfacial tension can achieve ultra-low values within the range of 10−2 to 10−3 mN/m. Oil sand cleaning experiments and indoor simulations of spontaneous imbibition in tight cores demonstrate that F-GQDs exhibit effective oil-washing capabilities and a strong response to carbon dioxide. When combined with carbon dioxide, the system enhances both the rate and efficiency of oil washing. Imbibition recovery can reach more than 50%. The research results provide a certain theoretical basis and data reference for the efficient development of tight reservoirs.

Hazard-consistent scenario selection for long-term storm surge risk assessment over extended coastal regions

The recent destructive hurricane seasons and concerns related to the future influence of climate change have increased the relevance of coastal storm hazards and, in particular, of storm surge hazard estimation when discussing the resilience of coastal communities. This hazard is generally represented as surge inundation probabilities over a large number of individual locations in the geographic domain of interest, and is typically assessed utilizing an ensemble of storm scenarios (i.e., storm events) that are representative of the regional climatology. This paper investigates the storm ensemble selection within this setting, with the objective of identifying a small number of storm scenarios that are consistent with some chosen hazard descriptions over a large geographic region. Beyond the storm events, the occurrence rates (i.e., weights) are also updated. Following past works, a two-stage optimization is adopted for the storm selection. The inner-loop identifies the occurrence rates for a given storm subset, formulating the problem as a linear programming optimization for the sum of absolute deviation for the predicted hazard. The outer-loop searches for the best subset with the desired number of storms, adopting a genetic algorithm integer optimization for minimizing the aforementioned deviation. This work extends this implementation to extended coastal regions, with many locations of interest. In this case, it is computationally intractable to consider all the locations in the domain within the linear programming formulation, and for this reason, a subset of representative locations is chosen through cluster analysis. The hazard description for only these locations is used in the storm ensemble selection. For clustering, different strategies using correlation between locations based on geospatial information, surge response, or a combination of both are examined. Additionally, the correlation in the hazard description is better integrated into the storm selection by establishing a modification of the objective function adopted for the outer optimization loop. Applications to different North Atlantic coastal domains are presented as case studies.

An efficient novel NiCu@INA/rGO MOF hollow microsphere Z-scheme heterojunction catalyst for the photocatalytic degradation of tetracycline and simultaneous degradation of cationic and anionic Dyes

Bimetallic metal-organic framework materials have captivated considerable attention in photocatalysis because of their colossal properties like semiconducting, large surface area, and potent visible light harnessing ability. Self-aggregation and rapid recombination rates have greatly hindered their applications in photocatalysis. A novel reduced graphene oxide-incorporated bimetallic nickel copper metal-organic framework (NiCu@INA/rGO MOF) is fabricated using isonicotinic acid as an organic linker. A synergistic effect between the two metals increased the photocatalytic performance. Introducing reduced graphene oxide to nickel-copper MOF increased charge carrier retention transfer and enhanced the catalyst’s water dispersibility. The efficiency of the photocatalyst for the removal of tetracycline (TCn) and a mixture of Rhodamine B (RhB) and Orange G (OrG) dyes was investigated under visible light. A degradation efficiency of up to 89 % for TCn and close to ∼97.8 % and 93.5 % degradation in the case of RhB and OrG dyes was observed. The studies on the photocatalytic degradation mechanism were explored by conducting radical scavenger experiments, Electron spin resonance (ESR) studies, and Mott-Schottky analysis. TCn and RhB degradation pathways were explored by mass spectral analysis of the intermediates during the photocatalytic degradation of TCn and RhB. This work provides new paradigms for the functional modification of MOF for designing efficient photocatalysis.

DFT study of adsorption and potential detection of carbonyl fluoride on B-doped aluminum nitride nanosheets

Carbonyl fluoride (COF2) is a decomposition product that can be used to find failures in gas-insulated switchgear equipment. In this study, we applied Density Functional Theory (DFT) calculations to examine the suitability of pristine and boron-doped aluminum nitride nanosheets (AlNNS) for COF2 adsorption and sensing applications. Our investigation suggested a dissociative COF2 adsorption on pristine AlNNS, resulting in important adsorption energy (–2.19 eV), the releasing of a fluorine atom from the molecule and formation of new C–N, O–Al and F–Al bonds. Two preferential chemisorption geometries were achieved on the B-doped N-vacancy monolayer (B-vN-AlNNS), with adsorption energies of –1.04 and –3.44 eV. In the first geometry, only an O–B bond was formed, whereas in the another one similar interactions as in COF2/AlNNS took place. Furthermore, we analyzed the evolution of electronic properties in order to evaluate the performance of these nanosheets for COF2 detection purposes. Our results showed significant modifications in both energy gap and work function only after COF2 adsorption on B-vN-AlNNS. Finally, charge transfer analysis revealed electron exchange from the studied surfaces to the gas molecule. These findings suggest that B-doped AlNNS exhibits good performance for COF2 detection, and could encourage further experimental research to develop efficient sensing materials.

Unearthing the hidden links: Investigating the functional connectivity between amygdala subregions and brain networks in bipolar disorder through resting-state fMRI

IntroductionBipolar disorder is a multifaceted psychiatric condition characterized by fluctuating activity levels and dysfunctional mood states, oscillating between manic and depressive episodes. These mood disturbances are accompanied by persistent functional and cognitive impairments, even during periods of euthymia. Prior studies have underscored the critical role of amygdala activity in the pathophysiology of bipolar disorder. This research aims to utilize resting-state functional Magnetic Resonance Imaging (rs-fMRI) to explore the functional modifications in the six sub-regions that compose the amygdala of individuals diagnosed with bipolar disorder. MethodThe study encompassed 80 participants, bifurcated into two groups: 40 individuals with bipolar disorder and 40 healthy controls. Each group comprised an equal gender distribution of 20 females and 20 males, ranging in age from 21 to 50 years. Using rs-fMRI, we examined the functional connectivity within six amygdala sub-regions across eight regional functional networks. ResultsComparative analysis between the control group and the bipolar patients revealed that all six amygdala sub-regions demonstrated connectivity with the eight functional brain networks. Notable similarities and disparities were observed in the connectivity patterns between the bipolar group and controls, particularly within the amygdala's sub-regions and other brain networks. The most significant functional connectivity alterations were found with the salience network and the default mode network. Additionally, alterations in the functional connectivity between the amygdala, sensory-motor, and visual networks were noted in bipolar patients. ConclusionThe study's findings highlight the distinct patterns of resting-state functional connectivity of the amygdala and various brain networks in differentiating bipolar patients from healthy controls. These variations suggest the existence of multiple pathophysiological mechanisms contributing to emotional dysregulation in bipolar disorder.

Unlocking the Door for Precision Medicine in Rare Conditions: Structural and Functional Consequences of Missense ACVR1 Variants.

Rare diseases and conditions have thus far received relatively less attention in the field of precision/personalized medicine than common chronic diseases. There is a dire need for orphan drug discovery and therapeutics in ways that are informed by the precision/personalized medicine scholarship. Moreover, people with rare conditions, when considered collectively across diseases worldwide, impact many communities. In this overarching context, Activin A Receptor Type 1 (ACVR1) is a transmembrane kinase from the transforming growth factor-β superfamily and plays a critical role in modulating the bone morphogenetic protein signaling. Missense variants of the ACVR1 gene result in modifications in structure and function and, by extension, abnormalities and have been predominantly linked with two rare conditions: fibrodysplasia ossificans progressiva and diffuse intrinsic pontine glioma. We report here an extensive bioinformatic analyses assessing the pool of 50,951 variants and forecast seven highly destabilizing mutations (R206H, G356D, R258S, G328W, G328E, R375P, and R202I) that can significantly alter the structure and function of the native protein. Protein-protein interaction and ConSurf analyses revealed the crucial interactions and localization of highly deleterious mutations in highly conserved domains that may impact the binding and functioning of the protein. cBioPortal, CanSAR Black, and existing literature affirmed the association of these destabilizing mutations with posterior fossa ependymoma, uterine corpus carcinoma, and pediatric brain cancer. The current findings suggest these deleterious nonsynonymous single nucleotide polymorphisms as potential candidates for future functional annotations and validations associated with rare conditions, further aiding the development of precision medicine in rare diseases.

Genome-wide identification and characterization of pectin methylesterase inhibitor gene family members related to abiotic stresses in watermelon.

Pectin is a vital component of plant cell walls and its methylation process is regulated by pectin methylesterase inhibitors (PMEIs). PMEIs regulate the structural and functional modifications of cell walls in plants and play an important role in plant processes such as seed germination, fruit ripening, and stress response. Although the PMEI gene family has been well characterized in model plants, the understanding of its molecular evolution and biological functions in watermelon remains limited. In this study, 60 ClPMEI genes were identified and characterized, revealing their dispersion on multiple chromosomes. Based on a systematic developmental analysis, these genes were classified into three subfamilies, which was further supported by the exon, intron, and conserved motif distribution. Analysis of cis-elements and expression patterns indicated that ClPMEIs might be involved in regulating the tolerance of watermelon to various abiotic stresses. Moreover, distinct ClPMEI genes exhibit specific functions under different abiotic stresses. For example, ClPMEI51 and ClPMEI54 showed a significant upregulation in expression levels during the late stage of drought treatments, whereas ClPMEI3 and ClPMEI12 displayed a significant downregulation under low-temperature induction. Subcellular localization prediction and analysis revealed that the ClPMEI family member proteins were localized to the cell membrane. This study provided an important foundation for the further exploration of the functions of ClPMEI genes in watermelon.

Surface Termination (-O, -F or -OH) and Metal Doping on the HER Activity of Mo2CTx MXene.

Two-dimensional MXenes have recently garnered significant attention as electrocatalytic materials for hydrogen evolution reaction (HER). However, previous theoretical studies mainly focused on the effect of pure functional groups while neglecting hybrid functional groups that are commonly observed in experiments. Herein, we investigated the hybrid functionalized Mo2CTx MXene (T=-O, -F or -OH) to probe the HER properties. In binary O/F co-functionalization, the presence of F groups would attenuate the H adsorption and lead to the enhanced HER activity than the fully O-terminated Mo2CO2. However, the surface HER activity of ternary O/F/OH functionalized Mo2CTx is not satisfactory owing to the relatively weak H adsorption capacity. To further enhance the catalytic activity, modification was performed by introducing another metal element into its lattice structure. The doped metal (Fe, Co, Ni, Cu) exhibits reduced charge transfer to O compared to Mo atoms, leading to enhanced H adsorption and improved overall activity. The synergistic effect of hybrid functionalization and TM modification provides useful guidance for achieving feasible Mo2CTx candidates with high HER performance, which can be applied to the electrocatalytic applications of other MXenes.

Value-based optimization model for cultural route design: Ancient Water Supply Heritage of Istanbul (Türkiye)

Cultural tourism has become an increasingly growing human activity in today's world. Therefore, various cultural/natural heritage areas or buildings face large tourist crowds, causing physical, social, or cultural deterioration. Cultural routes, which provide a systematic approach and planned tourists move, can reduce the negative effects of overtourism. This study aims to develop an optimization model as a supportive tool for the cultural route design process. The proposed optimization model aims to maximize cultural experience while satisfying constraints on heritage values, building types, historical eras, and general routing rules. Moreover, this model, creating optimized cultural routes, is expected to contribute to regulating economic income and tourist density. As a case study, the ancient water supply systems of Istanbul, inherited from the Roman and the Ottoman empires and currently overlooked, are investigated. Heritage values, mentioned in the extensive literature, are reviewed and the values/attributes for this study are appointed according to the characteristics of the case heritage assets, and their environment. The values of the case structures are evaluated with value analysis after field study. An optimum cultural route for Istanbul's historical water supply heritage, according to the objective and the constraints of the model, is obtained by solving the model with the case data. The resulting route can make this overlooked heritage of Istanbul recognized and spread the tourist density in the city center. The model is flexible, allowing for easy modification of the objective function, constraints, and values when designing routes across various heritage sites. This model can be used not only in the design of new cultural routes but also in optimizing existing routes.

Dental composite materials based on Zn/Al‐layered double hydroxide and their physical mechanical properties

AbstractDental materials' demands can be answered using composite materials, as composite properties are suitable for tailoring the material's behavior. Poly (methyl methacrylate) (PMMA) is usually a material of choice in dental applications, and its mechanical properties can be improved in terms of modulus, strength, and hardness. The chosen reinforcement in this publication was Zn/Al‐layered double hydroxide (LDH), as this material has functional property modification possibilities. The reinforcement was synthesized using the coprecipitation process on a laboratory scale. The dispersion of the reinforcement was done with ultrasonication, and the composites prepared contained 1, 3, and 5 wt% of reinforcement, and the so‐prepared composites were compared to the matrix. Improvements were observed in terms of the elastic modulus and tensile strength, and the best performance was observed in the composite with 3 wt% of particles. Hardness increased with the addition of particles and the higher the particle content, the better the hardness. Materials were tested using dynamic mechanical techniques, and it was proven that the addition of particles lowers the Tg of the composite compared to the pure matrix. The addition of particles diminished the affinity of the material for polar liquids such as water.Highlights Zn/Al‐layered double hydroxide is used to reinforce acrylic matrix. Composite with improved strength, modulus, and microhardness. Addition of a layered double hydroxide decreases hydrophobicity of composite.

Exploring the antibiofilm potential of chitosan nanoparticles by functional modification with chloroquine and deoxyribonuclease

Planktonic bacteria tend to form sessile community architectures to shield resident bacteria from various environmental stresses. The formed biofilm leads to the failure of conventional antimicrobial therapy. Extracellular macromolecules, including extracellular DNA (eDNA), proteins, lipids, and polysaccharides, crosslink into gel-like structures through electrostatic forces in the mature biofilm matrix. The stereo-structural integrity and chemical inertia of the extracellular polymeric matrix result in comprehensive antimicrobial resistance to antibacterial polysaccharides. Herein, an ionic gelation method was employed to functionalize cationic chitosan nanoparticles (CSNPs) with chloroquine and deoxyribonuclease. The modification involved shifting eDNA chirality through a DNA-intercalating agent, chloroquine, and hydrolyzing an eDNA scaffold with deoxyribonuclease. The antibiofilm activity was assessed against a standard Staphylococcus aureus strain and clinical subtype isolates. Functional modifications targeting eDNA improved the chitosan anti-biofilm efficiency (residual biomass decreased from 74.2 to 90.3 % to 16.7–24.6 %) by disrupting the biofilm matrix. The functional CSNPs worked as a sensitizer prodrug, contributing to a bactericidal process of chitosan itself (cell wall damage increased from 11.38–18.16 % to 55.2–61.4 %) by dispersing the biofilm-enclosed bacteria. In vivo, the bacterial burden of infected mouse joints was reduced by 4.1 lg CFU/mL. Our results indicate the potential of this chitosan-based anti-infection strategy in biofilm-related infections.

High-performance removal of methylene blue dye using porous lignin extracted from sugarcane bagasse by deep eutectic solvent

This study evaluated the ability of triethyl benzyl ammonium chloride/lactic acid deep eutectic solvent extracted lignin (TEBAC/LA-DES-L) to adsorb methylene blue (MB) without additional functional group modification. The structure and morphology of TEBAC/LA-DES-L were characterized using SEM, BET, FT-IR, and TGA techniques. Various factors influencing MB adsorption, such as extraction temperature, solution pH, adsorbent dose, initial MB concentration, adsorption time, and reaction temperature, were investigated. The Redlich-Peterson isotherm displayed a good fit for the experimental data, with a maximum adsorption capacity of 85.16 mg/g. Kinetic analysis suggested that the adsorption process followed the pseudo-second-order model, with adsorption occurring in <100 min on DES-L-4 h. The mechanism of MB adsorption on DES-L-4 h was attributed to electrostatic attraction, hydrophobic interactions, and hydrogen bonding forces. Overall, DES-L-4 h demonstrated high adsorption capacity and rapid adsorption rate, making it a promising adsorbent for effectively removing cationic dyes from wastewater.

Construction of rGO-MXene@FeNi/epoxy composites with regular honeycomb structures for high-efficiency electromagnetic interference shielding

With the rapid development of 5G communication technology and wearable electronic devices, the demand for low-reflection electromagnetic interference (EMI) shielding materials is becoming increasingly urgent. In this work, reduced graphene oxide-MXene (rGMH) @FeNi/epoxy EMI shielding composites with a regular honeycomb structure were successfully prepared by the combination of surface functionalization modification, sacrificial template, and freeze-drying. The effects of magnetic FeNi alloy particle loading mode and loading amount on the EMI shielding performance of composites were investigated. The results show that rGMH@FeNi/epoxy EMI shielding composites have the highest EMI shielding effectiveness (EMI SE) and the lowest reflection shielding effectiveness when magnetic FeNi alloy particles are loaded only on the graphene skeleton. In this composite, the EMI SE value of the composite is 61 dB when the rGMH@FeNi mass fraction is 5.4 wt% (f-FeNi mass fraction is 0.9 wt%), which is 4.7 times that of the blended rGO/MXene/FeNi/ epoxy resin composite (13 dB) with the same mass fraction. At the same time, the rGMH@FeNi/epoxy composite has excellent thermal stability (heat-resistance index of 190.3 °C) and mechanical properties (energy storage modulus of 8606.7 MPa). These polymer-based EMI shielding composites with excellent EMI shielding properties and low reflection effectiveness have great potential in the protection of high-power, portable and wearable electronic devices against electromagnetic pollution.

The Functions of SARS-CoV-2 Receptors in Diabetes-Related Severe COVID-19.

Angiotensin-converting enzyme 2 (ACE2) is considered a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor of high importance, but due to its non-ubiquitous expression, studies of other proteins that may participate in virus internalisation have been undertaken. To date, many alternative receptors have been discovered. Their functioning may provide an explanation for some of the events observed in severe COVID-19 that cannot be directly explained by the model in which ACE2 constitutes the central point of infection. Diabetes mellitus type 2 (T2D) can induce severe COVID-19 development. Although many mechanisms associated with ACE2 can lead to increased SARS-CoV-2 virulence in diabetes, proteins such as basigin (CD147), glucose-regulated protein 78 kDa (GRP78), cluster of differentiation 4 (CD4), transferrin receptor (TfR), integrins α5β1/αvβ3, or ACE2 co-receptors neuropilin 2 (NRP2), vimentin, and even syalilated gangliosides may also be responsible for worsening the COVID-19 course. On the other hand, some others may play protective roles. Understanding how diabetes-associated mechanisms can induce severe COVID-19 via modification of virus receptor functioning needs further extensive studies.

A simple and efficient approach for pore structure optimization and hydrophilic modification of PTFE nanofiber membrane

Polytetrafluoroethylene (PTFE) membranes have great potential for treating wastewater in harsh environment due to their excellent stability. However, difficulties in the pore structure optimization and functional modification of biaxial stretched PTFE membrane have limited its further applications in liquid separation. Herein, we presented a simple and efficient approach for the preparation and hydrophilic modification of electrospun PTFE nanofiber membranes. This method involved optimizing the pore structure of PTFE nanofiber membranes through adjusting the mass ratio of the spinning carrier polyethylene oxide (PEO) and PTFE, followed by introducing the acetalized polyvinyl alcohol (PVA) on the membrane’s pore surface to improve the hydrophilicity. The average pore size changed from 288.5 to 161.3 nm, while the water contact angle reduced from 135.7° to 50.9°, which not only increased the water permeate flux from 68.56 to 1056.16 L·m−2·h−1, but also achieved high rejection rates of 99.3 % and 97.3 % for carbon (1 μm) and SiO2 (100 nm) particles respectively. Meanwhile, the obtained PTFE nanofiber membrane also exhibited excellent hydrophilic stability after long term exposure to harsh environments (pH=2 HCl, pH=12 NaOH, 1000 ppm NaClO) and 100 friction cycles (5 g weights on 1000 mesh sandpaper). This approach of preparing hydrophilic PTFE nanofiber membranes showed significant potential for practical applications in wastewater treatment.

Cracking the Pericellular Matrix Code: Exploring how MMP-2, -3, and -7 influence matrix breakdown and biomechanical properties

IntroductionThe intricate process of articular cartilage remodeling, pivotal for both physiological functions and osteoarthritis (OA) progression, is orchestrated through a balance of matrix synthesis and breakdown, which is mediated by matrix metalloproteinase enzymes (MMPs). At the heart of this remodeling lies the pericellular matrix (PCM), a specialized microenvironment encapsulating each chondrocyte and composed mainly of collagen type VI and perlecan. The aim of this study was to assess the impact of MMP-2, -3, and -7 on the structural integrity and biomechanical attributes of the PCM. MethodsHuman articular cartilage explants (N=10 patients) were incubated with activated MMP-2, -3, or -7, individually or in combination. Structural alterations in the PCM were evaluated by immunolabeling. The biomechanical properties of the PCM were measured using atomic force microscopy (AFM). ResultsCollagen type VI structural integrity and fluorescence intensity uniformly decreased across all enzyme groups, while perlecan was selectively affected by MMP-3 and -7. AFM measurements demonstrated decreased PCM stiffness after incubation with individual MMPs, leading to an overall ~31 % reduction in elastic modulus for each enzyme. Combinations of enzymes induced comparable significant biomechanical alterations (~35 %), except for MMP-2+MMP-7. DiscussionThis study highlights the significant influence of MMP-induced alterations in PCM composition on biomechanical properties, mirroring characteristics observed in early OA. Each MMP showed specificity in breaking down PCM, and an intriguing interplay, especially between MMP-2 and -7, indicated reduced efficacy in lowering PCM stiffness. Overall, MMP-2, -3, and -7 directly induce functional and structural PCM modifications.