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The multibasic furin cleavage site at the S1/S2 boundary of the spike protein is a hallmark of SARS-CoV-2 and plays a crucial role in viral infection. However, the mechanism underlying furin activation and its regulation remain poorly understood. Here, we show that GalNAc-T3 and T7 jointly initiate clustered O-glycosylations in the furin cleavage site of the SARS-CoV-2 spike protein, which inhibit furin processing, suppress the incorporation of the spike protein into virus-like-particles and affect viral infection. Mechanistic analysis reveals that the assembly of the spike protein into virus-like particles relies on interactions between the furin-cleaved spike protein and the membrane protein of SARS-CoV-2, suggesting a possible mechanism for furin activation. Interestingly, mutations in the spike protein of the alpha and delta variants of the virus confer resistance against glycosylation by GalNAc-T3 and T7. In the omicron variant, additional mutations reverse this resistance, making the spike protein susceptible to glycosylation in vitro and sensitive to GalNAc-T3 and T7 expression in human lung cells. Our findings highlight the role of glycosylation as a defense mechanism employed by host cells against SARS-CoV-2 and shed light on the evolutionary interplay between the host and the virus. Here, the authors show that GalNAc-T3 and T7 regulate furin cleavage of the SARS-CoV-2 spike protein via O-glycosylation. This influences viral assembly and infection, highlighting glycosylation as a host defense mechanism. [ABSTRACT FROM AUTHOR]

This research combines simulation technology, a surrogate model, and a dung beetle optimizer (DBO) to propose a structural optimization design method for lightweight adhesive modules. The structure of the wall-climbing robot is introduced, and its adhesion stability is analyzed. Through simulation comparison of four typical Halbach array magnetic circuit modes, it was determined that the adhesion generated by the three-magnetic circuit structure mode is more advantageous. Determine the parameters that need to be optimized through sensitivity analysis. The Chebyshev model of adhesion force and parameters was established. An optimization model aimed at lightweight and the constraints of adhesion stability and structural parameters was set. The penalty function combined with DBO was used to solve the optimization model. Compared with before optimization, the weight of the adhesive module is reduced by 11.7 %. The experiments verified the adhesive module's adhesion force and the robot's load capacity. [ABSTRACT FROM AUTHOR]

Difficulties of in vitro culture and genetic manipulation of Eimeria tenella have hindered the screening of virulence factors in this parasite. In this study, the E. tenella rhoptry protein 30 (EtROP30) was expressed in Toxoplasma gondii (RH∆Ku80-EtROP30), and its effect on the proliferation and virulence of parasites was investigated. The results revealed that the expression of EtROP30 had no impact on the invasion and egress processes. However, the RH∆Ku80-EtROP30 strain formed larger plaques compared to the RH∆Ku80, indicating that the EtROP30 expression promotes T. gondii proliferation. Furthermore, the RH∆Ku80-EtROP30 strain exhibited greater pathogenicity, resulting in earlier mortality and shorter overall survival time compared to RH∆Ku80. These results imply that EtROP30 expression facilitates parasite intracellular proliferation and virulence in mice, suggesting that EtROP30 might be a candidate virulence factor of E. tenella. [ABSTRACT FROM AUTHOR]

The density of polymethyl methacrylate (PMMA) is about half that of inorganic glass. Hence, PMMA is expected to replace inorganic glass in vehicles such as automobiles to reduce weight. High and low temperature environments and dynamic loading need to be considered during its service. In this paper, an experimental investigation on the strain rate and temperature dependent mechanical behavior of PMMA was performed over the environmental temperature range of 243 K to 373 K and the strain rate range of 10−3 s−1 to 103 s−1. CM207 PMMA and PFE50 PMMA were used, and three kinds of specimens were fabricated by injection molding. The results show that two PMMAs have obvious strain rate and temperature sensitivity. The compressive modulus and yield strength increase with increasing strain rate. The strain rate sensitivity factor (SRSF) decreases as the temperature increases, indicating that high temperature can reduce the strain rate effect. PFE50 PMMA is more sensitive to the temperature, but CM207 PMMA is more sensitive to the strain rate. A modified ZWT constitutive model can be used to describe the strain rate and temperature dependent nonlinear mechanical behavior of PMMA. [ABSTRACT FROM AUTHOR]

Void defects in the matrix and between fibers inevitably occur during fabricating of fiber reinforced composites. Although the effects of matrix voids or interfiber voids on the properties of composites have been studied recently, the failure mechanisms and the damage evolution of composites with matrix voids and interfiber voids are still challenging to explore. The coupling effect between matrix voids and interfiber voids is also unclear. This work established three-dimensional parametric microstructure models simultaneously containing matrix voids and interfiber voids. The effects of void types and void volume fractions on the strength of composites are investigated quantitatively by the computational model. The damage evolution process is visualized, and the failure mechanisms and the coupling effect between various voids are explained on the microscale. Additionally, the failure envelopes of composites with different void volume fractions are provided in τ 13 - σ 22 stress space, which has good agreements with both the Hashin–Rotem and Puck failure criteria. The verified computational model composed of the microstructure model and the failure envelopes can help designers accurately and conventionally predict the properties of composite materials in engineering. [ABSTRACT FROM AUTHOR]

In the process of detecting the paint film thickness of offshore wind turbine towers, there are problems such as the risk of high-altitude and the changeable working environments, which pose a great threat to the safety of operators. In response to the above problems, a crawler-type climbing-robot system for measuring paint film thickness of offshore wind turbine towers is developed. Firstly, the robot structure is designed by adopting modular design idea. Secondly, the kinematics analysis of the robot's facade steering is carried out, and the kinematics model of the robot's instantaneous steering is established. On this basis, considering the influence of hydrodynamic force and track deformation, a dynamic model of multi-track coordinated motion is established. Then, the kinematics and dynamics of the robot are simulated and calculated by Matlab. The robot control system is designed according to the requirements of multi-module cooperative operation. Finally, a robot prototype is developed based on the theory and simulation, and the robot is verified through the experimental platform and the offshore wind power field experiment. [ABSTRACT FROM AUTHOR]

Enhanced oil recovery (EOR) has been widely used to recover residual oil after the primary or secondary oil recovery processes. Compared to conventional methods, chemical EOR has demonstrated high oil recovery and low operational costs. Nanofluids have received extensive attention owing to their advantages of low cost, high oil recovery, and wide applicability. In recent years, nanofluids have been widely used in EOR processes. Moreover, several studies have focused on the role of nanofluids in the nanofluid EOR (N-EOR) process. However, the mechanisms related to N-EOR are unclear, and several of the mechanisms established are chaotic and contradictory. This review was conducted by considering heavy oil molecules/particle/surface micromechanics; nanofluid-assisted EOR methods; multiscale, multiphase pore/core displacement experiments; and multiphase flow fluid-solid coupling simulations. Nanofluids can alter the wettability of minerals (particle/surface micromechanics), oil/water interfacial tension (heavy oil molecules/water micromechanics), and structural disjoining pressure (heavy oil molecules/particle/surface micromechanics). They can also cause viscosity reduction (micromechanics of heavy oil molecules). Nanofoam technology, nanoemulsion technology, and injected fluids were used during the EOR process. The mechanism of N-EOR is based on the nanoparticle adsorption effect. Nanoparticles can be adsorbed on mineral surfaces and alter the wettability of minerals from oil-wet to water-wet conditions. Nanoparticles can also be adsorbed on the oil/water surface, which alters the oil/water interfacial tension, resulting in the formation of emulsions. Asphaltenes are also adsorbed on the surface of nanoparticles, which reduces the asphaltene content in heavy oil, resulting in a decrease in the viscosity of oil, which helps in oil recovery. In previous studies, most researchers only focused on the results, and the nanoparticle adsorption properties have been ignored. This review presents the relationship between the adsorption properties of nanoparticles and the N-EOR mechanisms. The nanofluid behaviour during a multiphase core displacement process is also discussed, and the corresponding simulation is analysed. Finally, potential mechanisms and future directions of N-EOR are proposed. The findings of this study can further the understanding of N-EOR mechanisms from the perspective of heavy oil molecules/particle/surface micromechanics, as well as clarify the role of nanofluids in multiphase core displacement experiments and simulations. This review also presents limitations and bottlenecks, guiding researchers to develop methods to synthesise novel nanoparticles and conduct further research. [ABSTRACT FROM AUTHOR]

Structural colors have a demonstrated value in constructing various functional materials. Efforts in this area are devoted to developing stratagem for generating heterogeneous structurally colored materials with new architectures and functions. Here, inspired by icing process in nature and ice-templating technologies, we present freeze-derived heterogeneous structural color hydrogels with multiscale structural and functional features. We find that the space-occupying effect of ice crystals is helpful for tuning the distance of non-close-packed colloidal crystal nanoparticles, resulting in corresponding reflection wavelength shifts in the icing area. Thus, by effectively controlling the growth of ice crystals and photo-polymerizing them, structural color hydrogels with the desired structures and morphologies can be customized. Other than traditional monochromatic structure color hydrogels, the resultant hydrogels can be imparted with heterogeneous structured multi-compartment body and multi-color with designed patterns through varying the freezing area design. Based on these features, we have also explored the potential value of these heterotypic structural color hydrogels for information encryptions and decryptions by creating spatiotemporally controlled icing areas. We believe that these inverse ice-template structural color hydrogels will offer new routes for the construction and modulation of next generation smart materials with desired complex architectures. While most of the structural colored materials only present isotropic colors, limiting their functions and many practical applications, while realizing anisotropic structural color materials remains challenging. Here, the authors develop a freeze-derived heterogeneous structural color hydrogels for information encryption and decryption. [ABSTRACT FROM AUTHOR]

A multistage adaptive lateral deformation tracked robot is proposed based on module design. The mechanical structures of lateral and tracked deformations are established by analyzing the constraints of space barriers and the elastic potential energy change mechanism of internal storage. The interaction of the operating environment and the mechanism is analyzed during the deformation process, and the internal potential energy change mechanism is optimized using the NSGA-II algorithm. The dynamic model is established in RecurDyn software, and the main modules and their coupling relationships are analyzed. Finally, the robot prototype is fabricated, and the obstacle surmounting performance and deformation mode are verified through experimental tests. For small robots, it has the advantages of large load, long driving distance, strong obstacle surmounting ability, and stable steering on the slope, and for robots with the same size, it can increase or decrease its width, has stronger terrain passability and environmental adaptability, so that it can operate in different scenarios within the same mission. [ABSTRACT FROM AUTHOR]

Highlights: A novel stem cell delivery core-shell biomass microcapsule was generated by an all-aqueous phase microfluidic electrospray technique. Microcapsule with a certain mechanical strength and porous structure is beneficial for substances exchange between cells and the external environment, together with avoiding cell damage during treatment. Core-shell microcapsule provided a favorable cell growth microenvironment, which mimics a physicochemical microenvironment and protects the cells from the immune attack from body. Bone defects caused by trauma, tumor, or osteoarthritis remain challenging due to the lack of effective treatments in clinic. Stem cell transplantation has emerged as an alternative approach for bone repair and attracted widespread attention owing to its excellent biological activities and therapy effect. The attempts to develop this therapeutic approach focus on the generation of effective cell delivery vehicles, since the shortcomings of direct injection of stem cells into target tissues. Here, we developed a novel core-shell microcapsule with a stem cell-laden core and a biomass shell by using all-aqueous phase microfluidic electrospray technology. The designed core-shell microcapsules showed a high cell viability during the culture procedure. In addition, the animal experiments exhibited that stem cell-laden core-shell microcapsules have good biocompatibility and therapeutic effect for bone defects. This study indicated that the core-shell biomass microcapsules generated by microfluidic electrospray have promising potential in tissue engineering and regenerative medicine. [ABSTRACT FROM AUTHOR]

Perovskite quantum dots (PQDs) are new class of optoelectronic materials, which have been widely studied for their extraordinary physical properties. Attempts to develop these materials are tending to make their fabrication much controllable and extend their values in different areas. Here, we present a novel strategy for one-step in situ synthesis of PQD-encapsulated barcode particles with the assistance of microfluidic technique. By changing the halide ratio in perovskite precursor solutions that emulsified in microfluidic devices, a series of PQDs with different colors have been successfully fabricated, which made them ideal materials as barcodes. Because of the stable encapsulation of ethyleneglycol dimethacrylate (EGDMA) resin, the PQD-encapsulated barcode particles were with no cytotoxicity and could be anti-quenched. It was demonstrated for the first time that the PQD-encapsutated barcode particles by microfluidics were valuable for multiplex biomolecular encoding and assays. These features indicate that the PQD-encapsutated barcode particles by microfluidics are ideal for many practical applications and have a broad prospect in biomedical field. [ABSTRACT FROM AUTHOR]

Structural color materials with the property of angle-independence have attracted increasing interest in recent years because of their applications in various research fields. In this paper, inspired by the anisotropic lattice microstructure of the Parides sesostris butterfly, we present a novel angle-independent structural material by simply doping spinous pollen particles into the colloidal crystal arrays to interfere their self-assembling process. The resultant composited materials have anisotropic close-packed colloidal crystal domains around the spikes of the pollens. These differently oriented domains could reflect the light to a wide range of viewing angles, and thus imparted the composite materials with the same wide angle of structural colors. Attractively, the materials were endowed with light-controlled reversible structural color changing behavior by incorporating photothermal responsive graphene-tagged hydrogels. These features of the bioinspired angle-independent structural color materials showed their potential values in constructing intelligent sensors, anti-counterfeiting barcode labels, and so on. [ABSTRACT FROM AUTHOR]

The application of polymer composites as a substitution of metal is an effective approach to reduce vehicle weight. However, the final performance of composite structures is determined not only by the material types, structural designs and manufacturing process, but also by their mutual restrict. Hence, an integrated “material-structure-process-performance” method is proposed for the conceptual and detail design of composite components. The material selection is based on the principle of composite mechanics such as rule of mixture for laminate. The design of component geometry, dimension and stacking sequence is determined by parametric modeling and size optimization. The selection of process parameters are based on multi-physical field simulation. The stiffness and modal constraint conditions were obtained from the numerical analysis of metal benchmark under typical load conditions. The optimal design was found by multi-discipline optimization. Finally, the proposed method was validated by an application case of automotive hatchback using carbon fiber reinforced polymer. Compared with the metal benchmark, the weight of composite one reduces 38.8%, simultaneously, its torsion and bending stiffness increases 3.75% and 33.23%, respectively, and the first frequency also increases 44.78%. [ABSTRACT FROM AUTHOR]

A tube is often applied as an energy absorber in structures subject to impact loads. However, when several tubes are combined to absorb energy, how to arrange these tubes and match their dimensions has not been investigated. We provide a novel equivalent stiffness (ES) method for the initial design of tube-based energy absorbers, in which each tube is expressed by an equivalent spring with average post-buckling stiffness, and these springs are connected in series or parallel or hybrid. The plastic deformation and strain energy are distributed among them according to their relative ES value. The relationship between plastic energy and post-buckling stiffness is derived analytically and verified numerically. Finally, an application example is provided and the optimal tube arrangement and dimensions are obtained by combining the proposed ES method with an optimization code. The results demonstrate that this method can provide an initial design of tube-based energy absorbers efficiently. [ABSTRACT FROM AUTHOR]

Breast cancer is one of the most common cancer and remains the leading cause of cancer-related deaths in women. There is increasing evidence suggesting that TRPM7 plays a pivotal role in breast cancer progression and metastasis. In this study, a case-control study was carried out to investigate the effects of SNPs in TRPM7 genes in the development of breast cancer in Han Population of Northeast China. A total of six SNPs (rs8042919, rs4775899, rs11635825, rs7173321, rs616256, and rs11070795) were chosen and genotyped. Genotypes were analyzed using a single-base primer extension assay. Chi-square ( χ) test was used to analyze statistical difference between control and patient groups in genotype and allele frequencies. The genotype-specific risks and allele frequencies of haplotypes in breast cancer patients and controls were estimated by OR and 95 % confidence intervals. The G allele of rs8042919 was associated with a reduced disease risk. The G allele of rs7173321 and particularly its homozygous GG genotype are associated with an increased breast cancer risk. Two of the TRPM7 SNPs (rs8042919 and rs7173321) are associated with breast cancer patients in Han Population of Northeast China. [ABSTRACT FROM AUTHOR]

The excellent mechanical properties of carbon nanotubes make them potential candidates for engineering application. In this paper, the impact and failure behaviors of single-walled carbon nanotubes (SWCNTs) are investigated. The effects of diameter, length, and chirality on their energy absorption characteristics under lateral impact and axial crush are studied. By integrating the principle of molecular structural mechanics (MSM) into finite element method (FEM), the locations and directions of fracture process can be predicted. It is shown that the specific energy absorption (SEA) of SWCNTs is 1-2 order of magnitude higher than that of the ordinary metallic materials and composites in axial impact, indicating that carbon nanotubes are promising energy absorption materials for engineering applications. [ABSTRACT FROM AUTHOR]

Hypoxia-induced factors (HIFs) play a central role in the adaptive mechanisms of cancer cells to survive under conditions of hypoxia. HIFs are regulated by prolyl hydroxylases (PHDs) among which PHD3 is implicated as a tumor suppressor. We aimed to correlate PHD3 expression with clinicopathologic parameters and to evaluate its prognostic significance in gastric cancer. The 101 tissue samples were collected from 83 resected stages I–IV gastric cancer patients, which were grouped as non-cancerous mucosa (n=18) and primary carcinoma (n=83). PHD3 expression was evaluated by immunohistochemistry. We adopted Pearson chi-square test, univariate analysis, multivariate analysis and Kaplan–Meier method. The positive frequency of PHD3 in cancer cells was 42.2%, whereas non-cancerous mucosa had no detectable PHD3. The expression of PHD3 increased significantly from non-cancerous mucosa to cancer. A significant difference was observed between PHD3 expression and tumor differentiation (P=0.007). The overexpression of PHD3 was associated with well differentiation. In univariate analyses, American Joint Committee on Cancer (AJCC) stage (P<0.0001), pT classification (P<0.0001), pN classification (P<0.0001), differentiation (P=0.0121), peritoneal metastasis (P=0.0006) and gross features (P=0.0104) were significantly associated with survival except PHD3 (P=0.2228) (Table 3). In multivariate analysis, AJCC stage was prognostically independent [hazard ratio (HR), 3.078; 95% confidence interval (CI), 2.228–4.252; P<0.0001]. Overexpression of PHD3 is a favorable prognosticator for gastric cancer. AJCC stage is an independent prognostic factor of gastric cancer. [ABSTRACT FROM AUTHOR]

Background: Accumulating evidence suggests that the tumor suppressor gene Kruppel-like factor 6 (KLF6) and its dominant-negative splice form KLF6-SV1 play important roles in both the development and progression of cancer. However, the role of KLF6-SV1 in gastric cancer remains largely unknown. Methods: KLF6-SV1 expression was detected in various human gastric cancer cell lines and gastric cancer patient samples by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. Small interfering RNA (siRNA) was used to inhibit KLF6-SV1 expression in BGC-823 and SGC-7901 cell lines. The effects of downregulation of KLF6-SV1 by siRNA on cell proliferation, migration, invasion, and tumor growth were examined in vitro and in vivo. Results: Overexpression of KLF6-SV1 was detected in tumor samples from gastric cancer patients, and in various differentiated gastric cancer cell lines. In vitro downregulation of KLF6-SV1 by siRNA inhibited BGC-823 and SGC-7901 cell proliferation, anchorage-independent growth, migration, and invasion through the altered expression of Ki-67, vascular endothelial growth factor (VEGF), E-cadherin, and matrix metalloproteinase (MMP)-9. Also, KLF6-SV1 silencing promoted caspase-dependent apoptosis of BGC-823 and SGC-7901 cells via the regulation of phosphatidylinositol 3-OH kinase (PI3K)/Akt activity and Bcl-2-related protein expression. In vivo animal studies showed that KLF6-SV1 siRNA significantly inhibited the tumorigenicity of BGC-823 and SGC-7901 cells. Gene therapy with polyethylenimine/si-SV1 intratumoral injection also resulted in the suppression of tumor growth and prolonged animal survival in an established xenograft tumor model. Conclusion: These data demonstrate that KLF6-SV1 is an important regulator of the growth, migration, invasion, and survival of gastric cancer cells, and downregulation of KLF6-SV1 by siRNA may offer a new potential gene therapy approach for gastric cancer. [ABSTRACT FROM AUTHOR]

lthough impaired gastrointestinal motility from gastric cancer peritoneal metastasis (GCPM) causes extraordinary pain, its cause is unclear. Interstitial cells of Cajal (ICC) are apparently pacemaker cells, and their loss could cause motor dysfunction. In this study, we developed a mouse model for GCPM, and investigated electrophysiological changes in the small intestine and attendant changes in ICC. We found decreased ICC and disrupted electrical rhythm in the model. Pathologic ICC changes were well described. Cancer peritoneal metastasis may impair intestinal myoelectrical activity by damaging ICC and ICC networks. Interstitial cells of Cajal will be a target of palliative treatment and merit further study. [ABSTRACT FROM AUTHOR]