Polymorph selection of magnesium under different pressures: A simulation study

Molecular dynamics simulations were used to investigate the influence of pressure on the structural properties and dynamics of magnesium(Mg)during rapid solidification.The dynamics analysis revealed that,with an increase in pressure,the dynamics of Mg melt slowed down sharply and the dynamical heterogeneities increased,leading to a denser structure.Atom-level structural analysis using the cluster-type index method suggested that the predominant structure transformed from hexagonal closed-packed to face-centered cubic with increasing pressure from 0 GPa to 5 GPa,and then transformed to the A15 complex crystal structure as the pressure increased above 10 GPa.In addition,the nature of polymorph selection was investigated by analyzing the phonon dispersion of Mg under different pressures.These findings provide a novel insight into polymorphic transitions of Mg under pressure and guide the selection of Mg polymorphs for practical applications.

氮沉降对草地昆虫多样性影响的研究进展

昆虫是草地中数量和种类最丰富的生物类群之一,占据食物网的不同营养级,具有重要的生态服务功能。然而,全球范围内昆虫数量和多样性持续降低,对生态安全构成了潜在威胁。作为全球变化的主要组分,不断加剧的氮沉降导致植物多样性下降,但其对昆虫多样性的影响及机制尚不明确。由此,本文梳理了近年来国内外相关研究,发现氮沉降可以对昆虫种群数量和多样性产生正向、负向或中性影响,其作用方向主要依赖于氮沉降持续的时间和强度、不同昆虫类群和草地类型。氮沉降能够通过改变植物多样性、植物生物量、植物营养、群落结构、微环境等多种途径影响昆虫的食物资源、生境适宜性以及种间相互作用,进而对昆虫群落产生影响。未来从研究方法上应考虑氮沉降与其他全球变化因子的交互作用以及更大时空尺度的实验研究,从研究内容上应加强氮沉降对草地昆虫食物网和多营养级关系作用的理解,从研究机理上应重视昆虫关键功能性状对氮沉降的响应。本文有益于深入理解氮沉降对草地昆虫群落的作用规律及其调控机制,并为全球变化背景下草地昆虫多样性的保护提供理论指导。

A versatile 3D-printable hydrogel for antichondrosarcoma,antibacterial,and tissue repair

Following operative treatment of chondrosarcoma,post-surgery tissue reconstruction may be confronted with daunting challenges,including the delayed self-repair of defective tissue,tumor recurrence,and bac-terial infection.To overcome these challenges,a methacrylic anhydride(MA)modified sericin(SerMA)solution mixed with procyanidins(PC)loaded polydopamine(PDA)modified ZIF-8(PC@ZIF-8@PDA)nanoparticles to form a multifunctional PC@ZIF-8@PDA/SerMA hydrogel after exposure under blue light.Hydrogel products with pre-designed shapes were printed out by using the SerMA solution carrying PC@ZIF-8@PDA nanoparticles and chondrocytes,indicating that PC@ZIF-8@PDA/SerMA hydrogels with personalized shapes can be fabricated via 3D printing.Photocrosslinked PC@ZIF-8@PDA/SerMA hydrogel is able to kill chondrosarcoma cells and bacteria,like Staphylococcus aureus(S.aureus),and Escherichia coli(E.coli),by its photothermal activity combined with near-infrared radiation(NIR).The PC@ZIF-8@PDA/SerMA hydrogel exhibited an antioxidative activity and a good biocompatibility and was easily monitored by its florescent and photoacoustic properties.Rabbit articular cartilage defects were efficiently repaired by PC@ZIF-8@PDA/SerMA hydrogels with encapsulated corresponding autologous chondrocytes,and mice skin burning wounds were swiftly regenerated by applying this hydrogel.Hence,the PC@ZIF-8@PDA/SerMA hydrogel can be potentially applied to the clinic treatment of chondrosarcoma and tissue defect repair after chondrosarcoma resection due to its multifunction in the future.

Identification of potential indicators for testis quality in swamp eels(Monopterus albus)through metabolomics analysis

The swamp eel(Monopterus albus)is a commonly cultured freshwater fish.Selection and cultivation of fecund broodstock is crucial for efficient artificial reproduction in this species.However,there are currently no guidelines for selecting high-quality males in M.albus.This study quantitatively investigated the sperm motility of male swamp eels during the breeding season by using computer-assisted sperm analysis system.Variability in the proportion and number of motile sperm was observed between individual males.The testes were grouped into high-quality and low-quality according to sperm quality.Morphometric parameters of the two groups were analyzed.We found that high-quality testes were longer(150±27 mm verses 127±19 mm)than low-quality testes.Besides,the proportion of testes with a dark appearance was slightly higher(58.3%verses 48.1%)in the high-quality group than in the low-quality group.Metabolomic analysis was conducted to compare the metabolite profiles of high-quality and low-quality testes.Glycerophospholipids,organic acids,glycerolipids,amino acids,sphingolipids,and nucleotides were the most abundant metabolites in the testes of swamp eels.Moreover,135 differential metabolites were identified.Several nucleotide derivatives,including 50-deoxyadenosine,20-deoxyadenosine,and ribosyl adenosine,were the most significantly enriched metabolites in highquality testes.These metabolites are potential indicators for the testis quality in M.albus.Altogether,our work provides systematic and quantitative data about the physiological and biochemical characteristics of M.albus testis,which provides an evidential basis for the selection of high-fecundity parents to improve artificial reproduction efficiency of M.albus.

ASER:Animal Sex Reversal Database

Sex reversal,representing extraordinary sexual plasticity during the life cycle,not only triggers reproduction in animals but also affects reproductive and endocrine system-related diseases and cancers in humans.Sex reversal has been broadly reported in animals;however,an integrated resource hub of sex reversal information is still lacking.Here,we constructed a comprehensive database named ASER(Animal Sex Reversal)by integrating sex reversal-related data of 18 species from teleostei to mammalia.We systematically collected 40,018 published papers and mined the sex reversal-associated genes(SRGs),including their regulatory networks,from 1611 core papers.We annotated homologous genes and computed conservation scores for whole genomes across the 18 species.Furthermore,we collected available RNA-seq datasets and investigated the expression dynamics of SRGs during sex reversal or sex determination processes.In addition,we manually annotated 550 in situ hybridization(ISH),fluorescence in situ hybridization(FISH),and im-munohistochemistry(IHC)images of SRGs from the literature and described their spatial expression in the gonads.Collectively,ASER provides a unique and integrated resource for researchers to query and reuse organized data to explore the mechanisms and applications of SRGs in animal breeding and human health.The ASER database is publicly available at http://aser.ihb.ac.cn/.

Strong unique continuation property for a class of fourth order elliptic equations with strongly singular potentials

In this paper we prove the strong unique continuation property for a class of fourth order elliptic equations involving strongly singular potentials.Our argument is to establish some Hardy-Rellich type inequalities with boundary terms and introduce an Almgren’s type frequency function to show some doubling conditions for the solutions to the above-mentioned equations.

Strong Unique Continuation of Sub-elliptic Operator on the Heisenberg Group

In this paper, the Almgren＇s frequency function of the following sub-elliptic equation with singular potential on the Heisenberg group：-Cu＋V（z,t）u=Xi（aij（z,t）Xju）＋V（z,t）u=0 is introduced. The monotonicity property of the frequency is established and a doubling condition is obtained. Consequently, a quantitative proof of the strong unique continuation property for such equation is given.