Influence of Dowel Center Spacing on Chamfered-Joint Components Made byCupressus funebris Wood

The traditional tenon and mortise joint has low processing efficiency and a weak theoretical basis,making the structure easy to deform and damage,reducing the safety,and increasing waste of resources.This study aims to determine the optimum dowel center spacing parameter for chamfered-joint components and the maximum value of the strength of joints loaded into bending strength and tensile strength.In this study,an integrated opti-mization method combining the single-factor test and one-way ANOVA analysis was proposed to study the influ-ence of the dowel center spacing on the bending strength and the tensile strength of chamfered-joint components made by Cupressus funebris wood.The results revealed that the bending strength of chamfered-joint components decreases linearly with the increase of the dowel center spacing.In addition,the tensile strength of chamfered-joint components increases first and then decreases with the increase of the dowel center spacing,showing para-bola change.The relational expression between dowel center spacing,the bending strength,dowel center spacing and the tensile strength were obtained.

Rice sl-MH-1 mutant induces cell death and confers blast resistance via the synergistic roles of signaling systems

Serotonin is ubiquitous across all forms of life and functions in responses to biotic and abiotic stresses.In rice,the conversion of tryptamine to serotonin is catalyzed by Sekiguchi lesion(SL).Previous studies have identified an sl mutation(a null mutation of SL)in several rice varieties and confirmed its increase of resistance and cell death.However,a systematic understanding of the reprogrammed cellular processes causing cell death and resistance is lacking.We performed a multi-omics analysis to clarify the fundamental mechanisms at the protein,gene transcript,and metabolite levels.We found that cell death and Magnaporthe oryzae(M.oryzae)infection of the sl-MH-1 mutant activated plant hormone signal transduction involving salicylic acid(SA),jasmonic acid(JA),and abscisic acid(ABA)in multiple regulatory layers.We characterized the dynamic changes of several key hormone levels during disease progression and under the cell death conditions and showed that SA and JA positively regulated rice cell death and disease resistance.SL-overexpressing lines confirmed that the sl-MH-1 mutant positively regulated rice resistance to M.oryzae.Our studies shed light on cell death and facilitate further mechanistic dissection of programmed cell death in rice.

G protein-coupled receptors(GPCRs):advances in structures,mechanisms,and drug discovery

G protein-coupled receptors(GPCRs),the largest family of human membrane proteins and an important class of drug targets,play a role in maintaining numerous physiological processes.Agonist or antagonist,orthosteric effects or allosteric effects,and biased signaling or balanced signaling,characterize the complexity of GPCR dynamic features.In this study,we first review the structural advancements,activation mechanisms,and functional diversity of GPCRs.We then focus on GPCR drug discovery by revealing the detailed drug-target interactions and the underlying mechanisms of orthosteric drugs approved by the US Food and Drug Administration in the past five years.Particularly,an up-to-date analysis is performed on available GPCR structures complexed with synthetic small-molecule allosteric modulators to elucidate key receptor-ligand interactions and allosteric mechanisms.Finally,we highlight how the widespread GPCR-druggable allosteric sites can guide structure-or mechanism-based drug design and propose prospects of designing bitopic ligands for the future therapeutic potential of targeting this receptor family.

Flexible and ultrathin dopamine modified MXene and cellulose nanofiber composite films with alternating multilayer structure for superior electromagnetic interference shielding performance

With the development of modern electronics,especially the next generation of wearable electromagnetic interference(EMI)shielding materials requires flexibility,ultrathin,lightweight and robustness to protect electronic devices from radiation pollution.In this work,the flexible and ultrathin dopamine modified MXene@cellulose nanofiber(DM@CNF)composite films with alternate multilayer structure have been developed by a facile vacuum filtration induced self-assembly approach.The multilayered DM@CNF composite films exhibit improved mechanical properties compared with the homogeneous DM/CNF film.By adjusting the layer number,the multilayered DM3@CNF2 composite film exhibits a tensile strength of 48.14 MPa and a toughness of 5.28 MJ·m^(–3) with a thickness about 19μm.Interestingly that,the DM@CNF film with annealing treatment achieves significant improvement in conductivity(up to 17264 S·m^(–1))and EMI properties(SE of 41.90 dB and SSE/t of 10169 dB·cm^(2)·g–1),which still maintains relatively high mechanical properties.It is highlighted that the ultrathin multilayered DM@CNF film exhibits superior EMI shielding performance compared with most of the metal-based,carbon-based and MXene-based shielding materials reported in the literature.These results will offer an appealing strategy to develop the ultrathin and flexible MXene-based materials with excellent EMI shielding performance for the next generation intelligent protection devices.

Enhancing hydrogen evolution reaction performance of transition metal doped two-dimensional electride Ca_(2)N

Two-dimensional electride Ca_(2)N has strong electron transfer ability and low work function,which is a potential candidate for hydrogen evolution reaction(HER)catalyst.In this work,based on density functional theory calculations,we adopt two strategies to improve the HER catalytic activity of Ca_(2)N monolayer:introducing Ca or N vacancy and doping transition metal atoms(TM,refers to Ti,V,Cr,Mn,Fe,Zr,Nb,Mo,Ru,Hf,Ta and W).Interestingly,the Gibbs free energyΔG_(H*)of Ca_(2)N monolayer after introducing N vacancy is reduced to-0.146 e V,showing good HER catalytic activity.It is highlighted that,the HER catalytic activity of Ca_(2)N monolayer can be further enhanced with TM doping,the Gibbs free energyΔG_(H*)of single Mo and double Mn doped Ca_(2)N are predicted to be 0.119 and 0.139 e V,respectively.The present results will provide good theoretical guidance for the HER catalysis applications of two-dimensional electride Ca_(2)N monolayer.

iTRAQ-based protein profiling and functional identification of four genes involved in rice basal resistance against Magnaporthe oryzae in two contrasting rice genotypes

Rice blast,caused by Magnaporthe oryzae,is one of the most destructive rice diseases.Developing blast-resistant rice cultivars represents the most economical and environmentally friend strategy for managing the disease.In our previous study,an isobaric tags for relative and absolute quantitation(iTRAQ)-based comparative protein quantification was carried out to investigate the resistance gene Piz-t gene-mediated resistance response to infection in two contrasting rice genotypes of the Piz-t transgenic Nipponbare line(NPB-Piz-t)and its wild-type Nipponbare(NPB).Here,from the comparisons of differentially expressed proteins(DEPs)of NPB-Piz-t to the avirulent isolate KJ201(KJ201-Piz-t)and the virulent isolate RB22(RB22-Piz-t)with mock-treated NPB-Piz-t(Mock-Piz-t),NPB to the virulent isolate KJ201(KJ201-NPB)and RB22(RB22-NPB)with mock-treated NPB(Mock-NPB),1,1,and 6 common DEPs were,respectively,identified at 24,48 and 72 h post-inoculation(hpi)in the susceptible comparisons of RB22-Pizt/Mock-Piz-t,KJ201-NPB/Mock-NPB,and RB22-NPB/Mock-NPB,involving in gi|54,290,836 and gi|59,800,021 were identified in the resistance comparison KJ201-Piz-t/Mock-Piz-t at 48 and 72 hpi respectively.Moreover,four genes of Os01g0138900(gi|54,290,836),Os04g0659300(gi|59,800,021),Os09g0315700(gi|125,563,186)or Os04g0394200(gi|21,740,743)were knocked out or overexpressed in NPB using gene over-expression and CRISPR/Cas9 technology,and results verified that the Os01g0138900 obviously affected the rice blast resistance.Further,expression and targeted metabolomics analysis illuminated the resistance response of cysteine-containing substances as gi|59,800,021 under blast infection.These results provide new targets for basal resistance gene identification and open avenues for developing novel rice blast resistant materials.

Design and characterization of metallic glass/graphene multilayer with excellent nanowear properties

The excellent properties of metallic glass(MG)films make them perfect candidates for the use in miniature systems and tools.However,their high coefficients of friction(COFs)and poor wear resistance considerably limit their long-term performance in nanoscale contact.We report the fabrication of a MG/graphene multilayer by the repeated deposition of Cu_(50)Zr_(50) MG with alternating layers of graphene.The microstructure of the multilayer was characterized by the transmission electron microscopy(TEM).Its mechanical and nanotribological properties were studied by nanoindentation and nanoscratch tests,respectively.A molecular dynamics(MD)simulation revealed that the addition of graphene endowed the MG with superelastic recovery,which reduced friction during nanoscratching.In comparison with the monolithic MG film,the multilayer exhibited improved wear resistance and a low COF in repeated nanowear tests owing to the enhanced mechanical properties and lubricating effect caused by the graphene layer.This work is expected to motivate the design of other novel MG films with excellent nanowear properties for engineering applications.