从富含缺陷的碳载体到酞菁钴的质子供给用于增强CO_(2)电还原

利用可再生电力将二氧化碳转化为高附加值产品的电催化二氧化碳还原反应(CO_(2)RR)是一项具有革命性潜力的技术,因而备受关注.其中,一氧化碳被视为CO_(2)RR中最具经济效益的产物之一,可直接利用费托合成工艺将其用于合成醛、酮、烃类等产品.酞菁钴(CoPc)作为单位点催化剂,因其高原子利用率和高催化选择性能,在二氧化碳转化为一氧化碳过程中具有很大优势.然而,CoPc无法为CO_(2)RR中的质子化过程提供足够质子,导致其在工业大电流密度下的效率较低.因此,探索一种能够解决CO_(2)RR中质子供给不足问题的高效电催化剂对于提升CO_(2)RR的性能至关重要.本文设计了具有增强质子供给作用的缺陷碳纳米管(d-CNT),将其作为导电载体分散CoPc,用于制备CoPc/d-CNT电催化剂.通过引入富缺陷的碳纳米管(d-CNT),加速水解离进而增加CO_(2)RR的质子供给量.X射线光电子能谱、X射线吸收近边光谱和扩展X射线吸收精细结构谱结果表明,CoPc/d-CNT成功合成,同时保留了CoPc完整的Co-N4配位结构.透射电镜、粉末X射线衍射谱和拉曼光谱共同表明,d-CNT表面缺陷相对于商用CNT明显增加.动力学实验和原位衰减全反射表面增强红外吸收光谱研究表明,含大量缺陷的d-CNT具有加速水解离的能力,显著提高了二氧化碳还原反应过程中的质子供给,从而促进了CoPc_上CO_(2)活化生成*COOH.同时,密度泛函理论计算结果表明,d-CNT表面缺陷位点上从吸附水(*H2O)到质子水(H3O+)的吉布斯自由能为0.74 eV,远低于CNT(超过2 eV),表明d-CNT促进了水解过程和质子传递,再次证实了d-CNT降低了水分子解离的势垒.通过实验和理论的共同验证,阐明了d-CNT中的缺陷能够促进水解离,改善CO_(2)RR反应过程中质子供给,增强CoPc高效催化CO_(2)RR的能力.因此,CoPc/d-CNT混合材料表现出较好的催化性能.在电流密度为500 mA cm^(-2)的流动电池中,CoPc/d-CNT的CO法拉第效率(FECO)高达96%.相对而言,CoPc/CNT在200 mA cm^(-2)时FECO已经下降到90%以下.此外,在150 mA cm^(-2)的电流密度下,CoPc/d-CNT能够在20 h内维持FECO超过90%.综上,本文通过引入具有水解离能力的缺陷碳位点,解决了单位点催化剂CoPc在CO_(2)RR中质子供给不足的问题,为设计高性能催化剂提供了新见解.

Sepsis-associated liver injury:Mechanisms and potential therapeutic targets

In this editorial,we examined a recent article in the World Journal of Gastroenterology that focused on sepsis-associated liver injury(SLI)and its treatment.SLI is a serious complication of sepsis,primarily caused by microcirculatory disturbances,the gut-liver axis,and inflammatory responses.Specific treatment recommendations for SLI are lacking.The gut-liver axis represents a potential therapeutic target,with metformin showing promise in modulating the gut microbiome and enhancing intestinal barrier function.Although immunomodulatory therapies are being explored,anti-tumor necrosis factor agents and interleukin-1 receptor antagonists have not demonstrated significant clinical benefits.Statins may reduce liver inflammation and prevent injury in sepsis,but their clinical application is limited.Reduced D-related human leucocyte antigen expression on monocytes and lymphocytes suggests immune suppression in patients,indicating that corticosteroids could reverse clinical deterioration in severe infections and address adrenal cortical insufficiency.Current large-scale studies on glucocorticoid therapy for sepsis have yielded mixed results,likely due to inadequate assessment of the immune status of the host.Future research should prioritize the development of personalized immunotherapy tailored to patients’immune profiles,focusing on identifying novel indicators of immune status and advancing immunomodulatory targets and therapeutics for septic patients.

Orthogonally woven 3D nanofiber scaffolds promote rapid soft tissue regeneration by enhancing bidirectional cell migration

Repairing large-area soft tissue defects caused by traumas is a major surgical challenge.Developing multifunctional scaffolds with suitable scalability and favorable cellular response is crucial for soft tissue regeneration.In this study,we developed an orthogonally woven three-dimensional(3D)nanofiber scaffold combining electrospinning,weaving,and modified gas-foaming technology.The developed orthogonally woven 3D nanofiber scaffold had a modular design and controlled fiber alignment.In vitro,the orthogonally woven 3D nanofiber scaffold exhibited adjustable mechanical properties,good cell compatibility,and easy drug loading.In vivo,for one thing,the implantation of an orthogonally woven 3D nanofiber scaffold in a full abdominal wall defect model demonstrated that extensive granulation tissue formation with enough mechanical strength could promote recovery of abdominal wall defects while reducing intestinal adhesion.Another result of diabetic wound repair experiments suggested that orthogonally woven 3D nanofiber scaffolds had a higher wound healing ratio,granulation tissue formation,collagen deposition,and re-epithelialization.Taken together,this novel orthogonally woven 3D nanofiber scaffold may provide a promising and effective approach for optimal soft tissue regeneration.

通过诱导局域电场和电子局域化协同碱性析氢

碱性析氢反应(HER)可将间歇性可再生能源转化为可存储的清洁能源,因而备受关注.然而,水解离速度缓慢以及H中间体(*H)吸附和解吸困难限制了碱性HER的进一步发展.目前,针对碱性电解水解离缓慢问题,通常采用调整电催化剂结构降低水分解热动力学能垒,以及改变三相界面微环境加速中间产物的扩散等方法来促进水分解进行.此外,可以通过调控活性位点电子结构来优化*H的吸脱附.但是采用单一的策略很难同时促进H_(2)O的解离和*H的吸脱附,难以获得令人满意的碱性HER性能.因此,探索一种能同时促进H_(2)O的解离和*H的吸脱附协同策略对提升碱性HER的性能至关重要.本文提出了一种协同策略,通过构建高曲率二硫化钴纳米针(CoS_(2)NNs)和原子级铜(Cu)的掺杂分别实现诱导纳米尺度的局域电场和原子尺度的电子局域化,从而促进碱性HER的H_(2)O解离和*H吸脱附.首先,采用有限元法模拟和密度泛函理论计算,从理论上分别证实了纳米尺度局域电场可以加速H_(2)O解离以及原子尺度电子局域化可以促进*H吸附.受理论计算结果启发,通过一步水热法和原位硫化相结合的方法制备了高曲率的Cu掺杂CoS_(2)纳米针(Cu-CoS_(2)NNs).采用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)和四探针测试等技术进行表征,研究了Cu-CoS_(2)NNs的形貌、物相结构、化学组成和导电性.结果表明,在Cu原子引入后,Cu-CoS_(2)NNs依然保持着高曲率的纳米针结构,证明了Cu在CoS_(2)NNs中的原子分散状态.相较于低曲率的Cu掺杂CoS_(2)纳米线(Cu-CoS_(2)NWs),Cu-CoS_(2)NNs只存在形貌上的区别,二者的化学组成和比例均非常接近.同时,上述材料都具有很强的导电性,且电导率基本相同,这与有限元模拟结果一致.原位衰减全反射红外光谱和电响应测试结果表明,Cu-CoS_(2)NNs具有较好的解离H_(2)O和吸附*H的能力.在1 mol L^(-1)KOH溶液和10 mA cm^(-2)电流密度下,该催化剂的析氢过电位仅为64 mV,展现出较好的电化学析氢性能.催化剂还表现出非常好的碱性析氢稳定性,在标准氢电势(RHE)-0.18 V下,可在100 mA cm^(-2)电流密度下稳定工作达100 h.综上所述,本文通过诱导局域电场和电子局域化构建了一种协同策略,所制备的Cu-CoS_(2)NNs表现出很好的催化碱性HER性能和应用前景,为碱性HER电催化剂的理性设计提供了一定的参考.

Effect of the capsule on deformation and densification behavior of nickel-based superalloy compact during hot isostatic pressing

The Shima yield criterion used in finite element analysis for nickel-based superalloy powder compact during hot isostatic pressing(HIP) was modified through uniaxial compression experiments. The influence of cylindrical capsule characteristics on FGH4096M superalloy powder compact deformation and densification behavior during HIP was investigated through simulations and experiments. Results revealed the simulation shrinkage prediction fitted well with the experimental shrinkage including a maximum shrinkage error of 1.5%. It was shown that the axial shrinkage was 1.7% higher than radial shrinkage for a cylindrical capsule with the size of ∮50 mm × 100 mm due to the force arm difference along the axial and radial direction of the capsule. The stress deviated from the isostatic state in the capsule led to the uneven shrinkage and non-uniform densification of the powder compact. The ratio of the maximum radial displacement to axial displacement increased from0.47 to 0.75 with the capsule thickness increasing from 2 to 4 mm. The pressure transmission is related to the capsule thickness, the capsule material performance, and physical parameters in the HIP process.

A 32-gene risk index： a new prognostic approach for prostate cancer progression

Radical prostatectomy （RP） has been a widely accepted and standard treat-ment for clinically localized and locally advanced prostate cancer. However, effective clinical management of RP patient remains being challenged, given that conventional prognostic factors, including Gleason score, pT stage, surgical margin status and presurgery serum prostatespecific antigen （PSA）,

Universal and efficient hybrid modeling and direct slicing method for additive manufacturing processes

Model design and slicing contour generation in additive manufacturing(AM)data processing face challenges in terms of efficiency and scalability when stereolithography files generated by complex functionally graded structures have millions of faces.This paper proposes a hybrid modeling and direct slicing method for AM to efficiently construct and handle complex three-dimensional(3D)models.All 3D solids,including conformal multigradient structures,were uniformly described using a small amount of data via signed distance fields.The hybrid representations were quickly discretized into numerous disordered directed lines using an improved marching squares algorithm.By establishing a directional HashMap to construct the topological relationship between lines,a connecting algorithm with linear time complexity is proposed to generate slicing contours for manufacturing.This method replaces the mesh reconstruction and Boolean operation stages and can efficiently construct complex conformal gradient models of arbitrary topologies through hybrid modeling.Moreover,the time and memory consumption of direct slicing are much lower than those of previous methods when handling hybrid models with hundreds of millions of faces after mesh reconstruction.

Gene Structure and Expression of the High-affinity Nitrate Transport System in Rice Roots

Rice has a preference for uptake of ammonium over nitrate and can use ammonium-N efficiently. Consequently, transporters mediating ammonium uptake have been extensively studied, but nitrate transporters have been largely ignored. Recently, some reports have shown that rice also has high capacity to acquire nitrate from growth medium, so understanding the nitrate transport system in rice roots is very important for improving N use efficiency in rice. The present study Identified four putative NRT2 and two putative NAR2 genes that encode components of the high-affinity nitrate transport system （HATS） in the rice （Oryza sativa L. subsp, japonica cv. Nipponbare） genome. OsNRT2.1 and OsNRT2.2 share an Identical coding region sequence, and their deduced proteins are closely related to those from mono-cotyledonous plants. The two NAR2 proteins are closely related to those from mono-cotyledonous plants as well. However, OsNRT2.3 and OsNRT2.4 are more closely related to Arabidopsis NRT2 proteins. Relative quantitative reverse trsnscription-polymerase chain reaction analysis showed that all of the six genes were rapidly upregulated and then downrsgulated in the roots of N-starved rice plants after they were re-supplied with 0.2 mM nitrate, but the response to nitrate differed among gene members. The results from phylogenetic tree, gene structure and expression analysis implied the divergent roles for the Individual members of the rice NRT2 and NAR2 families. High-affinity nitrate influx rates associated with nitrate induction in rice roots were investigated and were found to be regulated by external pH. Compared with the nitrate influx rates at pH 6.5, alkaline pH （pH 8.0） inhibited nitrate influx, and acidic pH （pH 5.0） enhanced the nitrate influx in 1 h nitrate induced roots, but did not significantly affect that in 4 to 8 h nitrate induced roots.

Selective laser melting of near-α titanium alloy Ti-6Al-2Zr-1Mo-1V:Parameter optimization, heat treatment and mechanical performance

This paper presents a comprehensive study conducted to optimize the selective laser melting(SLM)parameters and subsequent heat-treatment temperatures for near-α high-temperature titanium alloy Ti-6 Al-2 Zr-1 Mo-1 V(TA15),which is widely used in the aerospace industry.Based on the surface morphology and relative density analysis,the optimized process parameters were:laser power from 230 W to 380 W,scan speed from 675 mm/s to 800 mm/s,scan spacing of 0.12 mm,and layer thickness of0.03 mm.The effects of the laser power and the layer thickness on the phase constitutions,microstructure features,as well as room-temperature and high-temperature(500℃) tensile properties,were then studied to obtain an in-depth understanding of SLM-built TA15.Six typical temperatures(650,750,850,950,1000 and 1100℃) covering three representative temperature ranges,i.e.,martensite partial decomposition temperature range,martensite complete decomposition temperature range and above βtransus temperature,were subsequently selected as heat-treatment temperatures.The heat treatmentmicrostructure-mechanical property relationships of SLM-built TA15 were elucidated in detail.These results provide valuable information on the development of SLM-built TA15 alloy for industrial applications,and these findings are also beneficial to additive manufacturing of other near-α Ti alloys with desirable high-temperature properties.

Regulation of the High-Affinity Nitrate Transport System in Wheat Roots by Exogenous Abscisic Acid and Glutamine

Nitrate is a major nitrogen （N） source for most crops. Nitrate uptake by root cells is a key step of nitrogen metabolism and has been widely studied at the physiological and molecular levels. Understanding how nitrate uptake is regulated will help us engineer crops with improved nitrate uptake efficiency. The present study investigated the regulation of the high-affinity nitrate transport system （HATS） by exogenous abscisic acid （ABA） and glutamine （Gin） in wheat （Triticum aestivum L.） roots. Wheat seedlings grown in nutrient solution containing 2 mmol/L nitrate as the only nitrogen source for 2weeks were deprived of N for 4d and were then transferred to nutrient solution containing 50 μmol/L ABA, and 1 mmol/L Gin in the presence or absence of 2 mmol/L nitrate for 0, 0.5, 1, 2, 4, and 8 h. Treated wheat plants were then divided into two groups. One group of plants was used to investigate the mRNA levels of the HATS components NRT2 and NAR2 genes in roots through semi-quantitative RT-PCR approach, and the other set of plants were used to measure high-affinity nitrate influx rates in a nutrient solution containing 0.2 mmol/L ^15N-labeled nitrate. The results showed that exogenous ABA induced the expression of the TaNRT2.1, TaNRT2.2, TaNRT2.3, TaNAR2.1, and TaNAR2.2 genes in roots when nitrate was not present in the nutrient solution, but did not further enhance the induction of these genes by nitrate. Glutamine, which has been shown to inhibit the expression of NRT2 genes when nitrate is present in the growth media, did not inhibit this induction. When Gin was supplied to a nitrate-free nutrient solution, the expression of these five genes in roots was induced. These results imply that the inhibition by Gin of NRT2 expression occurs only when nitrate is present in the growth media. Although exogenous ABA and Gin induced HATS genes in the roots of wheat, they did not induce nitrate influx.

Crack Types, Mechanisms, and Suppression Methods during High-energy Beam Additive Manufacturing of Nickel-based Superalloys: A Review

Nickel-based superalloys have been widely used in aerospace fields,especially for engine hot-end parts,because of their excellent high-temperature resistance.However,they are difficult to machine and process because of their special properties.High-energy beam additive manufacturing(HEB-AM)of nickel-based superalloys has shown great application potential in aerospace and other fields.However,HEB-AM of nickel-based superalloys faces serious cracking problems because of the unique characteristics of superalloys,and this has become the most significant bottleneck restricting their application.In this review,the current research status related to the types,formation mechanisms,and suppression methods of cracks in nickel-based superalloys produced by HEB-AM is described.The initiation and propagation mechanisms of cracks and their multiple influencing factors are also analyzed and discussed.Then,several possible research directions to solve the cracking problems in nickel-based superalloys produced by HEB-AM are outlined.This review provides an in-depth and comprehensive understanding of the cracking problem in AM nickel-based superalloys.It also provides valuable references for AM crack-free nickel-based superalloy components.

Characteristics of distribution of Mycobacterium tuberculosis lineages in China

The genotyping methods of Mycobacterium tuberculosis would dramatically improve our understanding of the molecular epidemiology of tuberculosis. 3,929 isolates, from a National Survey of Drug-Resistant Tuberculosis in 2007 in China, were successfully genotyped by large sequence polymorphisms and 15 loci variable number tandem repeats. We found that 2,905(2,905/3,929, 73.9%) cases belonged to Lineage 2, dominated in the east and central regions, 975 cases(975/3,929, 24.8%) were Lineage 4, highly prevailed in the west regions, and 36 and 13 cases were Lineage 3 and Lineage 1, respectively. We also explored the associations between lineages(Lineage 2 vs. Lineage 4) and clinical characteristics by logistic regression. For Lineage 2, the risk factors were Han-ethnicity population and fever. However, for Lineage 4, they were occupation(farmer), and degree of education(non-literate). Fully understanding of the distribution of Mycobacterium tuberculosis lineage and its risk factors would play a critical role in tuberculosis prevention, control, and treatment.

Nanotechnology for diagnosis and therapy of theumatoid arthritis:Evolution towards theranostic approaches

Rheumatoid arthritis(RA),as a chronic autoimmune disease,damages the bone and cartilage of patients,and even leads to disability.Therefore,the diagnosis and treatment of RA is particularly important.However,due to the complexity of RA,it is difficult to make effective early diagnosis of RA,which is detrimental to RA treatment.Besides,long-term intake of anti-RA drugs can also cause damage to patients' organs.The emergence of nanotechnology provides the new train of thoughts for the diagnosis and treatment of RA.And the combination of diagnosis and therapy is an ideal method to solve the problem of disease management of RA patients.In this review,we summarize the mechanism and microenvironment of RA,discuss the commonly used diagnostic techniques and therapeutic drugs for RA,and review their advantages and disadvantages.New nanotherapy strategies such as drug-carrying nanoparticles,PTT,PDT are listed,and their applications in RA treatment are also summarized.In addition,multimodal imaging,combined therapy and responsive diagnosis and treatment are also summarized as important contents.At last,we also review typical nanocarriers that can be used in the integration of diagnosis and therapy,and discussed their potential applications in RA theranostics.

Synthesis and anti-inflammatory activity of gold-nanoparticle bearing a dermatan sulfate disaccharide analog

A dermatan sulfate （DS） repeating disaccharide analog, β-L-idopyranosiduronate-（1→3）-2-amino-2- deoxy-4,6-di-O-sulfo-β-D-galactopyranoside, has been convergently synthesized and successfully applied to prepare the GAG-functionalized gold glyconanoparticle. This new material exhibited good anti-inflammatory activity which was comparable to that of the drug ibuprofen incarrageenan-induced paw edema in a rat model.

Characteristics of Liver Functions in Patients With COVID-19 and Construction of a Prognostic Evaluation Decision Model Based on Liver Functions

A number of studies have suggested that coronavirus disease 2019(COVID-19)can cause liver damage.However,clinical features and outcome of COVID-19 in patients with liver injury remain to be further investigated.In this study,the clinical data of 265 COVID-19 patients admitted to seven tertiary hospitals were collected.Based on a threshold for transaminase or total bilirubin levels at two times the normal upper limit,patients were divided into mild or moderate/severe liver injury groups.Among the 265 patients,183 patients showed liver injury within 48 hours of admission.Aspartate aminotransferase levels were predominantly elevated in the liver injury group,but albumin levels were reduced.Moreover,fibrinogen and D-dimer were significantly increased.Furthermore,68%of the patients with moderate/severe liver injury had one or more underlying diseases.Almost half of these patients developed acute respiratory distress syndrome(44%)and secondary infections(46%).These patients showed increased interleukin-6 and interleukin-10 levels and a decrease in PaO2 and the oxygenation index.In addition,levels of alanine aminotransferase,aspartate aminotransferase,and albumin were correlated with the oxygenation index,D-dimer and lymphocyte counts.Furthermore,a novel prognostic assessment model based on liver function was established,which accuracy reached 88%and was able to accurately assess the prognosis of COVID-19 patients.

Response of bacterial communities to short-term pyrene exposure in red soil

Pyrene, a representative polycyclic aromatic hydrocarbon （PAH） compound produced mainly from incomplete combustion of fossil fuels, is hazardous to ecosystem health. However, long-term exposure studies did not detect any significant effects of pyrene on soil microorganism. In this study, short-term microcosm experiments were conducted to identify the immediate effect of pyrene on soil bacterial communities. A freshly- collected pristine red soil was spiked with pyrene at 0, 10, 100, 200, and 500 mg.kg-~ and incubated for one day and seven days. The bacterial communities in the incubated soils were analyzed using 16S rRNA sequencing and terminal restriction fragment length polymorphism （T- RFLP） methods. The results revealed high bacterial diversity in both unspiked and pyrene-spiked soils. Only at the highest pyrene-spiking rate of 500 mg.kg-~, two minor bacteria groups of the identified 14 most abundant bacteria groups were completely suppressed. Short-term exposure to pyrene resulted in dominance of Proteobac- teria in soil, followed by Acidobacteria, Firmutes, and Bacteroidetes. Our findings showed that bacterial commu- nity structure did respond to the presence of pyrene but recovered rapidly from the perturbation. The intensity of impact and the rate of recovery showed some pyrene dosage-dependent trends. Our results revealed that differ- ent levels of pyrene may affect the bacterial community structure by suppressing or selecting certain groups of bacteria. It was also found that the bacterial community was most susceptible to pyrene within one day of the chemical addition.

Algorithms for checking channel passing in web service choreography

Web service choreography describes global mod- els of service interactions among a set of participants. For an interaction to be executed, the participants must know the required channel（s） used in the interaction, otherwise the ex- ecution will get stuck. Since channels are composed dynami- cally, the initial channel set of each participant is often insuf- ficient to meet the requirements. It is the responsibility of the participants to pass required channels owned （known） by one to others. Since service choreography may involve many par- ticipants and complex channel constraints, it is hard for de- signers to specify channel passing in a choreography exactly as required. We address the problem of checking whether a service choreography lacks channels or has redundant chan- nels, and how to automatically generate channel passing based on interaction flows of the service choreography in the case of channel absence. Concretely, we propose a sim- ple language Chorc, a channel interaction sub-language for modeling the channel passing aspect of service choreography. Based on the formal operational semantics of Chore, the algo- rithms for static checking of service choreography and gen- erating channel passing are also studied, and the complexity results of algorithms are discussed. Moreover, some illus- trated service choreography examples are presented to show how to formalize and analyze service choreography with channel passing in Chorc.

Nano-structured Hollow Carbon Materials from a Non-isothermal Chemical Vapor Deposition of Polyphenols

Pyrogallic acid(PG)was used as a modeling carbon source in fabricating nano-structured hollow carbon materials(HCMs)by a chemical vapor deposition(CVD)method.We found that non-isothermal deposition can improve the integrity of the obtained HCMs.The different pyrolyzed species from PG under varied temperatures lead to the temperature-dependent deposition yield,graphitization degree and morphology of the HCMs.HCMs including hollow spheres of varied sizes,cubic boxes with yolk-shell structure,nanotubes,mesoporous particles and double-shelled fibers,were prepared by using different templates,demonstrating the universality of this strategy.The carbon source has been extended to other plant polyphenols.The abundant and renewable solid precursors for CVD method endow this strategy excellent operation safety,improved storage and transportation convenience mnd low cost,mnd would boost the production of morphology-and size-controlled HCMs and their applications in the fields such as water treatment,electrode materials,adsorbent,drug delivery,and so forth.