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The effect of LaB6 on the densification and microstructure of pressure‐less sintered 0.4B4C–0.4SiC–0.2ZrB2 ternary ceramic with eutectic composition was investigated. The Vickers hardness, bending strength, and fracture toughness of the quaternary ceramic were discussed based on the microstructural characteristics. The densification of the 0.4B4C–0.4SiC–0.2ZrB2 ceramic was enhanced with increasing LaB6 content from 0 to 70 mol% (the proportion to B4C–SiC–ZrB2). When the LaB6 content was 50 mol%, the densification rate of the composite ceramic reached a peak. The 0.27B4C–0.27SiC–0.13ZrB2–0.33LaB6 quaternary composite ceramic has reached a density of over 95% after being sintered at 2 100°C for 1 h. The B4C and SiC phases had refined grains of 1–3 µm with intragranular structures in the as‐sintered ceramics. The hardness and strength reached 17.9 ±.8 GPa and 307 ± 38 MPa, respectively. Crack deflection and branching were ascribed to the improved fracture toughness of 3.78 ±.26 MPa·m1/2. This study provides new ideas for fabricating dense non‐oxide ceramic composites with enhanced properties. [ABSTRACT FROM AUTHOR]

Hemorrhagic fever with renal syndrome caused by hantaviruses has long been a serious public health issue in Yunnan Province. Hantaviruses exhibit a high extent of biodiversity in their natural hosts, particularly in mammalian hosts. This study was conducted to screen for hantaviruses in bats and rodents in Yunnan Province and elucidate their genetic characteristics and possible zoonotic disease risk. Hantaviruses were detected in 202 bats and 372 rodents with the positive rates 27.49% and 1.25% respectively. A novel lineage (named Lineage 10) of the Seoul virus (SEOV) from rodents and the geographic clustering of hantavirus in bats were identified using phylogenetic analyses of the full-length M- and S-segments. Our study suggest a high cross-species transmissibility of hantaviruses in bats and existence of a new lineage of SEOV in rodents differing significantly from other SEOVs. These results provide data to support the prevention and control of hantavirus-associated diseases in Yunnan Province. Author summary: Hantavirus is an important pathogen that can cause hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). HFRS has long been a serious public health problem in Yunnan Province. However, the molecular epidemiology and host characteristics of hantavirus in Yunnan Province are still unclear. Therefore, we screened hantaviruses in bats and rodents in selected areas of Yunnan from 2018 to 2022 and found the 10th SEOV lineage in rodents, as well as new geographic clusters of Xuan son virus (XSV) and novel hantavirus in bats. We proposed the possibility of the 10th SEOV lineage in rodents as an ancestral lineage and explained the related host-switching events in bat hantaviruses. These results provide data to reveal a greater risk of zoonotic disease and support the prevention and control of hantavirus-associated diseases and in Yunnan Province. [ABSTRACT FROM AUTHOR]

Purpose: To address the application requirements of soft actuators in rehabilitation training gloves, and in combination with ergonomic requirements, we designed a segmented soft actuator with bending and elongation modules. This actuator can achieve independent or coupled movements of the finger joints. Methods: A finite element model of the joint actuator was established to compare the driving performance of actuators with different structural forms. Numerical calculations were used to analyze the effects of structural size parameters on the bending characteristics and end output force of the actuator. The design was then refined based on these analyses. Results: The joint actuator designed in this study demonstrated a 71% increase in bending angle compared to the standard fast pneumatic network structure. Key factors affecting the driving performance include the thickness of the constraint layer, the inner wall thickness of the chamber, chamber height, chamber width, chamber spacing, chamber length, and the number of chambers. After improvements, the bending angle of the joint actuator increased by 60.6%, and the output force increased by 145.9%, indicating significant improvement. Conclusion: This study designed and improved a soft actuator for hand rehabilitation training, achieving independent and coupled joint movements. The bending angle, bending shape, and joint driving force of the soft actuator meet the requirements for finger rehabilitation training. [ABSTRACT FROM AUTHOR]

The monoamine transporters, including the serotonin transporter (SERT), dopamine transporter (DAT), and norepinephrine transporter (NET), are the therapeutic targets for the treatment of many neuropsychiatric disorders. Despite significant progress in characterizing the structures and transport mechanisms of these transporters, the regulation of their transport functions through dimerization or oligomerization remains to be understood. In the present study, we identified a conserved intramolecular ion-pair at the third extracellular loop (EL3) connecting TM5 and TM6 that plays a critical but divergent role in the modulation of dimerization and transport functions among the monoamine transporters. The disruption of the ion-pair interactions by mutations induced a significant spontaneous cross-linking of a cysteine mutant of SERT and an increase in cell surface expression but with an impaired specific transport activity. On the other hand, similar mutations of the corresponding ion-pair residues in both DAT and NET resulted in an opposite effect on their oxidation-induced dimerization, cell surface expression, and transport function. Reversible biotinylation experiments indicated that the ion-pair mutations slowed down the internalization of SERT but stimulated the internalization of DAT. In addition, cysteine accessibility measurements for monitoring SERT conformational changes indicated that substitution of the ion-pair residues resulted in profound effects on the rate constants for cysteine modification in both the extracellular and cytoplasmatic substrate permeation pathways. Furthermore, molecular dynamics simulations showed that the ion-pair mutations increased the interfacial interactions in a SERT dimer but decreased it in a DAT dimer. Taken together, we propose that the transport function is modulated by the equilibrium between monomers and dimers on the cell surface, which is regulated by a potential compensatory mechanism but with different molecular solutions among the monoamine transporters. The present study provided new insights into the structural elements regulating the transport function of the monoamine transporters through their dimerization. [ABSTRACT FROM AUTHOR]

Site museum is a kind of special public building constructed at the original place where the historical sites were unearthed, in which the unearthed relics are preserved and exhibited. The environmental control of such buildings is usually face with the problems of high energy consumption and disturbance between relics and visitors since the relics and visitors sharing the same indoor space. Local environment control is an efficient way to reduce energy consumption and achieve personalized air supply. In this research, a novel local ventilation system for the visitor corridor in winter, by combining displacement ventilation and air curtain, was proposed. Experimental tests of the system were conducted in an experimental hall with both tourist corridor and relics preservation. The results show that the visitor corridor was successfully local heated with average temperature higher than 16°C when both the displacement ventilation system and air curtain were switched on. The environmental temperature meets thermal comfort standards for short-term stay. The air curtain could efficiently prevent the infiltration of cold air and provide a warm air layer to cover the occupied area, such that thermal plume of the displacement ventilation was effective restrained.

The emergence and rapid spread of methicillin‐resistant Staphylococcus aureus (MRSA) raise a critical need for alternative therapeutic options. New antibacterial drugs and targets are required to combat MRSA‐associated infections. Based on this study, celastrol, a natural product from the roots of Tripterygium wilfordii Hook. f., effectively combats MRSA in vitro and in vivo. Multi‐omics analysis suggests that the molecular mechanism of action of celastrol may be related to Δ1‐pyrroline‐5‐carboxylate dehydrogenase (P5CDH). By comparing the properties of wild‐type and rocA‐deficient MRSA strains, it is demonstrated that P5CDH, the second enzyme of the proline catabolism pathway, is a tentative new target for antibacterial agents. Using molecular docking, bio‐layer interferometry, and enzyme activity assays, it is confirmed that celastrol can affect the function of P5CDH. Furthermore, it is found through site‐directed protein mutagenesis that the Lys205 and Glu208 residues are key for celastrol binding to P5CDH. Finally, mechanistic studies show that celastrol induces oxidative stress and inhibits DNA synthesis by binding to P5CDH. The findings of this study indicate that celastrol is a promising lead compound and validate P5CDH as a potential target for the development of novel drugs against MRSA. [ABSTRACT FROM AUTHOR]

The currently reported methods for preparing cellulose acetate hydrogels use chemical reagents as cross-linking agents, and the prepared ones are non-porous structured cellulose acetate hydrogels. Nonporous cellulose acetate hydrogels limit the range of applications, such as limiting cell attachment and nutrient delivery in tissue engineering. This research creatively proposed a facile method to prepare cellulose acetate hydrogels with porous structures. Water was added to the cellulose acetate–acetone solution as an anti-solvent to induce the phase separation of the cellulose acetate–acetone solution to obtain a physical gel with a network structure, where the cellulose acetate molecules undergo re-arrangement during the replacement of acetone by water to obtain hydrogels. The SEM and BET test results showed that the hydrogels are relatively porous. The maximum pore size of the cellulose acetate hydrogel is 380 nm, and the specific surface area reaches 62 m2/g. The porosity of the hydrogel is significantly higher than that of the cellulose acetate hydrogel reported in the previous literature. The XRD results show that the nanofibrous morphology of cellulose acetate hydrogels is caused by the deacetylation reaction of cellulose acetate. [ABSTRACT FROM AUTHOR]

Increased multiantibiotic-resistant bacteria means that infected bone defects remain a significant challenge to clinics. Great interest has emerged in the use of non-antibiotic antimicrobials to reduce the rate of multiantibiotic-resistant bacterial infection and facilitate bone regeneration. The cationic antimicrobial peptide LL-37 is the sole human cathelicidin and has shown nonspecific activity against a broad spectrum of microorganisms. In this study, we fabricated the poly(lactic-co-glycolic acid)/β-calcium phosphate/peptide LL-37 (PLGA/TCP/LL-37, PTL) scaffold with low-temperature 3D-printing technology for the treatment of infected segmental bone defects. The prepared scaffolds were divided into three groups: a high LL-37 concentration group (PTHL), low LL-37 concentration group (PTLL) and blank control group (PT). The cytocompatibility and antimicrobial activity of the engineered scaffolds were tested in vitro, and their osteogenesis properties were assessed in vivo in a rat infected bone defect model. We found the fabricated PTL scaffold had a well-designed porous structure that could support a steady and prolonged LL-37 release. Furthermore, the PTHL group showed strong antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) without any inhibition of the proliferation or alkaline phosphatase activity of rat bone marrow mesenchymal stem cells (BMSCs) in vitro. In addition, the infected femoral defects implanted with PTHL group displayed new bone formation in four weeks without any evidence of residual bacteria, which showed similar antibacterial outcomes to the vancomycin and cancellous bone mixture group. In conclusion, the PTHL composite scaffold is a promising non-antibiotic antimicrobial graft with good biodegradability, biocompatibility, and osteogenic capability for infected bone defects. [ABSTRACT FROM AUTHOR]