Effects of Dietary Changes on the Gut Microbiota of Cynops orientalis

The gut microbiota plays a pivotal role in the maintenance of health for amphibians,and it has been fully recognized,but the effectiveness of various influencing factors has not yet been fully clarified.Although this association should be considered while the amphibian order Caudata is facing a severe situation of population decline and extinction,there is little understanding of the association between diets and the diversity of gut microbiota in the amphibian order Caudata.Here,we conducted an extensive analysis of the gut microbiota of Cynops orientalis fed different diets using functional prediction and 16S rRNA amplicon sequencing techniques.First,we found that wild individuals had greater gut microbial diversity and richness in comparison to captive individuals.Second,we identified the bacterial taxa associated with diets and observed differences in the relative abundance of gut microbiota among people on various diets.Finally,we have a predictive comprehension of the selection and adaptative significance of shared core ASVs in the gut microbiota in maintaining the healthy survival of C.orientalis in a large-scale spatiotemporal map.Our study emphasizes how diets alter the gut microbiota of Caudata and offers fresh perspectives on the conservation and captive management of species in Caudata.

Cross-heterogeneous Domain Authentication Scheme Based on Blockchain

With the rising popularity of the Internet and the development of big data technology,an increasing number of organizations are opting to cooperate across domains to maximize their benefits.Most organizations use public key infrastructure to ensure security in accessing their data and applications.However,with the continuous development of identity-based encryption(IBE)technology,small-and medium-sized enterprises are increasingly using IBE to deploy internal authentication systems.To solve the problems that arise when crossing heterogeneous authentication domains and to guarantee the security of the certification process,we propose using blockchain technology to establish a reliable cross-domain authentication scheme.Using the distributed and tamper-resistant characteristics of the blockchain,we design a cross-domain authentication model based on blockchain to guarantee the security of the heterogeneous authentication process and present a cross-domain authentication protocol based on blockchain.This model does not change the internal trust structure of each authentication domain and is highly scalable.Furthermore,on the premise of ensuring security,the process of verifying the signature of the root certificate in the traditional cross-domain authentication protocol is improved to verify the hash value of the root certificate,thereby improving the authentication efficiency.The developed prototype exhibits generality and simplicity compared to previous methods.

Plasma–wave interaction in helicon plasmas near the lower hybrid frequency

We study the characteristics of plasma–wave interaction in helicon plasmas near the lower hybrid frequency.The(0D)dispersion relation is derived to analyze the properties of the wave propagation and a 1D cylindrical plasma–wave interaction model is established to investigate the power deposition and to implement the parametric analysis.It is concluded that the lower hybrid resonance is the main mechanism of the power deposition in helicon plasmas when the RF frequency is near the lower hybrid frequency and the power deposition mainly concentrates on a very thin layer near the boundary.Therefore,it causes that the plasma resistance has a large local peak near the lower hybrid frequency and the variation of the plasma density and the parallel wavenumber lead to the frequency shifting of the local peaks.It is found that the magnetic field is still proportional to the plasma density for the local maximum plasma resistance and the slope changes due to the transition.

壶菌感染对两栖动物种群影响的研究现状与挑战

加强生物多样性保护与共建地球生命共同体是我国的重大战略。两栖动物是脊椎动物中生物多样性受威胁最严重的类群,两种壶菌Batrachochytrium dendrobatidis(Bd)和B.salamandrivorans(Bsal)的感染是两栖动物多样性下降的主要因素之一。Bd主要感染两栖动物无尾目、有尾目和蚓螈目的皮肤,可能引起两栖动物淋巴细胞凋亡和全身电解质失衡。Bsal主要感染有尾目,可能导致两栖动物致命的败血症。针对壶菌及其感染对两栖动物种群影响的研究在国外已经开展了大量工作,然而我国在该领域的研究有限。本文通过检索1990–2022年国内外文献,梳理和总结了壶菌病原的可能起源与传播、壶菌感染的发病机制、壶菌毒力的影响因素和壶菌病原体的诊断与防治等领域的研究,并提出了未来的研究方向和技术方法的改进需求,如利用全基因组测序技术溯源、开发RPA技术进行野外检测和应用转录组学研究宿主–病原体的免疫等。最后,提出以下4条建议:(1)建设壶菌病原基础数据平台,建立壶菌病常规检测部门,并将壶菌病监测纳入野生动物疫病监测体系;(2)深入开展我国两栖动物不同地理区系壶菌感染情况的相关研究;(3)探索学科交叉与部门合作,如流行病学、免疫学、微生物学和生态学等;(4)加强国际交流合作,构建符合特殊亚洲环境的壶菌感染和预测模型。本研究将为两栖动物保护拓展新思路,助力我国两栖动物保护的可持续发展。

3D bioprinting of cell-laden nano-attapulgite/gelatin methacrylate composite hydrogel scaffolds for bone tissue repair

Bone tissue engineering(BTE)has proven to be a promising strategy for bone defect repair.Due to its excellent biological properties,gelatin methacrylate(GelMA)hydrogels have been used as bioinks for 3D bioprinting in some BTE studies to produce scaffolds for bone regeneration.However,applications for load-bearing defects are limited by poor mechanical properties and a lack of bioactivity.In this study,3D printing technology was used to create nano-attapulgite(nano-ATP)/GelMA composite hydrogels loaded into mouse bone mesenchymal stem cells(BMSCs)and mouse umbilical vein endothelial cells(MUVECs).The bioprintability,physicochemical properties,and mechanical properties were all thoroughly evaluated.Our findings showed that nano-ATP groups outperform the control group in terms of printability,indicating that nano-ATP is beneficial for printability.Additionally,after incorporation with nano-ATP,the mechanical strength of the composite hydrogels was significantly improved,resulting in adequate mechanical properties for bone regeneration.The presence of nano-ATP in the scaffolds has also been stud-ied for cell-material interactions.The findings show that cells within the scaffold not only have high viability but also a clear proclivity to promote osteogenic differentiation of BMSCs.Besides,the MUVECs-loaded composite hydrogels demonstrated increased angiogenic activity.A cranial defect model was also developed to evaluate the bone repair capability of scaffolds loaded with rat BMSCs.According to histo-logical analysis,cell-laden nano-ATP composite hydrogels can effectively im prove bone regeneration and promote angiogenesis.This study demonstrated the potential of nano-ATP for bone tissue engineering,which should also increase the clinical practicality of nano-ATP.

Interface engineering of MXene-based heterostructures for lithiumsulfur batteries

High energy density and low cost make lithium-sulfur(Li-S)batteries as one of the next generation's promising energy storage systems.However,the following problems need to be solved before commercialization:(i)the shuttling effect and sluggish redox kinetics of lithium polysulfides in sulfur cathode;(ii)the formation of lithium dendrites and the crack of solid electrolyte interphase;(iii)the large volume changes during charge and discharge processes.MXenes,as newly emerging two-dimensional transition metal carbides/nitrides/carbonitrides,have attracted widespread attention due to their abundant active surface terminals,adjustable vacancies,and high electrical conductivity.Designing MXene-based heterogeneous structures is expected to solve the stacking problem induced by hydrogen bonds or Van der Waals force and to provide other charming physiochemical properties.Herein,we generalize the design principles of MXene-based heterostructures and their functions,i.e.,adsorption and catalysis in advanced conversion-based Li-S batteries.Firstly,the physiochemical properties of MXene and MXene-based heterostructures are briefly introduced.Secondly,the catalytic functions of MXene-based heterostructures with the compositional constituents including carbon materials,metal compounds,organic frameworks,polymers,single atoms and special high-entropy MXenes are comprehensively summarized in sulfur cathodes and lithium anodes.Finally,the challenges of MXene-based heterostructure in current Li-S batteries are pointed out and we also provide some enlightenments for future developments in high-energy-density Li-S batteries.

Genetic Algorithm‑Based SOTIF Scenario Construction for Complex Traffic Flow

The Safety of The Intended Functionality(SOTIF)challenge represents the triggering condition by elements of a specific scenario and exposes the function limitation of an autonomous vehicle(AV),which leads to hazards.As for operationcontent-related features,the scenario is similar to AVs’SOTIF research and development.Therefore,scenario generation is a significant topic for SOTIF verification and validation procedure,especially in the simulation testing of AVs.Thus,in this paper,a well-designed scenario architecture is first defined,with comprehensive scenario elements,to present SOTIF trigger conditions.Then,considering complex traffic disturbance as trigger conditions,a novel SOTIF scenario generation method is developed.An indicator,also known as Scenario Potential Risk,is defined as the combination of the safety control intensity and the prior collision probability.This indicator helps identify critical scenarios in the proposed method.In addition,the corresponding vehicle motion models are established for general straight roads,curved roads,and safety assessment areas.As for the traffic participants’motion model,it is designed to construct the key dynamic events.To efficiently search for critical scenarios with the trigger of complex traffic flow,this scenario is encoded as genes and it is regenerated through selection,mutation,and crossover iteration processes,known as the Genetic Algorithm(GA).Experimental results show that the GA-based method could efficiently construct diverse and critical traffic scenarios,contributing to the construction of the SOTIF scenario library.

Cotton GhMYB7 is predominantly expressed in developing fibers and regulates secondary cell wall biosynthesis in transgenic Arabidopsis

The secondary cell wall in mature cotton fibers contains over 90%cellulose with low quantities of xylan and lignin.However,little is known regarding the regulation of secondary cell wall biosynthesis in cotton fibers.In this study,we characterized an R2R3-MYB transcription factor,Gh MYB7,in cotton.Gh MYB7 is expressed at a high level in developing fibers and encodes a MYB protein that is targeted to the cell nucleus and has transcriptional activation activity.Ectopic expression of Gh MYB7 in Arabidopsis resulted in small,curled,dark green leaves and also led to shorter inflorescence stems.A cross-sectional assay of basal stems revealed that cell wall thickness of vessels and interfascicular fibers was higher in transgenic lines overexpressing Gh MYB7 than in the wild type.Constitutive expression of Gh MYB7 in Arabidopsis activated the expression of a suite of secondary cell wall biosynthesis-related genes(including some secondary cell wall-associated transcription factors),leading to the ectopic deposition of cellulose and lignin.The ectopic deposition of secondary cell walls may have been initiated before the cessation of cell expansion.Moreover,Gh MYB7 was capable of binding to the promoter regions of At SND1 and At Ces A4,suggesting that Gh MYB7 may function upstream of NAC transcription factors.Collectively,these findings suggest that Gh MYB7 is a potential transcriptional activator,which may participate in regulating secondary cell wall biosynthesis of cotton fibers.

An extreme-condition model for quantifying growth kinetics of colloidal metal nanoparticles

A strategy has been developed for analyzing growth kinetics of colloidal metal nanoparticle quantitatively by focusing both the very early and the very late growth stages,at which the size of growing nanoparticles and the reaction time follow linear functions.Applying this extremecondition model to a microwave-assistant synthesis of colloidal silver nanoparticles,for the first time,results in the determination of intrinsic kinetics parameters involving in the growth of the silver nanoparticles.The diffusion coefficient (D) of the precursor species containing Ag+ is 4.9 × 10^-14 m^2/s and the surface reaction rate constant (k) of the precursor species on the surface of the growing silver nanoparticles is 8.7 × 10^-8 m/s in an ethylene glycol solution containing 0.15 M polwinylpyrrolidone at 140 ℃.The extreme-condition model is ready to deconvolute the intrinsic kinetics parameters of growing colloidal nanoparticles once the enlargement rate of the nanoparticles can be experimentally measured in real time and with high temporal resolution.Availability of the high-fidelity values of k and D will provide the crucial information to guide the design and synthesis of colloidal metal nanoparticles with the desirable properties.

Microwave synthesis of single-phase nanoparticles made of multiprincipal element alloys

Metal nanoparticles of multi-principal element alloys(MPEA)with a single crystalline phase have been synthesized by flash heating/cooling of nanosized metals encapsulated in micelle vesicles dispersed in an oil phase(e.g.,cyclohexane).Flash heating is realized by selective absorption of a microwave pulse in metals to rapidly heat metals into uniform melts.The oil phase barely absorbs microwave and maintains the low temperature,which can rapidly quench the high-temperature metal melts to enable the flash cooling process.The precursor ions of four metals,including Au,Pt,Pd,and Cu,can be simultaneously reduced by hydrazine in the aqueous solution encapsulated in the micelle vesicles.The resulting metals efficiently absorb microwave energy to locally reach a temperature high enough to melt themselves into a uniform mixture.The duration of microwave pulse is crucial to ensure the reduced metals mix uniformly,while the temperature of oil phase is still low to rapidly quench the metals and freeze the single-phase crystalline lattices in alloy nanoparticles.The microwave-enabled flash heating/cooling provides a new method to synthesize single-phase MPEA nanoparticles of many metal combinations when the appropriate water-in-oil micelle systems and the appropriate reduction reactions of metal precursors are available.

Predicting the Incident Cases of Emerging Infectious Disease Using a Bayesian Probability Model--China,February 2020

What is already known about this topic?The exact number of incident cases of emerging infectious diseases on a daily basis is of great importance to the disease control and prevention,but it is not directly available from the current surveillance system in time.What is added by this report?In this study,a Bayesian statistical method was proposed to estimate the posterior parameters of the gamma probability distribution of the lag time between the onset date and the reporting time based on the surveillance data.And then the posterior parameters and corresponding cumulative gamma probability distribution were used to predict the actual number of new incident cases and the number of unreported cases per day.The proposed method was used for predicting COVID-19 incident cases from February 5 to February 26,2020.The final results show that Bayesian probability model predictions based on data reported by February 28,2020 are very close to those actually reported a month later.What are the implications for public health practice?This research provides a Bayesian statistical approach for early estimation of the actual number of cases of incidence based on surveillance data,which is of great value in the prevention and control practice of epidemics.