多级钯-铜-银多孔纳米花作为高效电催化剂催化CO_(2)还原为C_(2+)产物

近年来,具有可控元素分布的铜基多金属纳米晶作为CO_(2)还原反应(CO_(2)RR)的电催化剂,受到了广泛研究。通过对铜电催化剂进行二次甚至多次的金属元素修饰,能够有效改变其整体d带结构并引起d带中心的位移。这种变化可以影响铜对关键中间体的表面亲和力,从而影响后续的催化途径。除了调整电子结构,形貌工程也成为提高CO_(2)RR电催化性能的有效手段。相对于随机形状的球形颗粒,基于二维纳米片构建的三维多孔结构有利于最大限度地暴露表面原子,为催化过程中产生的关键中间体提供丰富的扩散通道和反应中心。然而,通过设计合成路线构建这种类型的纳米结构是一项技术挑战,传统的分步自组装策略耗时且难以精确控制结构。因此,我们的研究旨在实现高纯度的合成方法,制备这种独特的纳米结构,并精确调控元素组成和电子结构,以探索结构优势与CO_(2)RR电化学性能改善之间的潜在关系,具有重要的应用价值。在此研究中,我们合理设计了钯-铜-银(Pd-Cu-Ag)纳米晶的二维-三维杂化结构,实现了可控的合成过程,并验证了其在电化学CO_(2)还原中的应用潜力。合成过程中,通过使用封装剂十八烷基三甲基氯化铵,成功地将Au@Cu_(x)O纳米球转化为层状CuAg纳米花(HNFs)。有趣的是,该过程中原位形成了作为构建单元的纳米薄片。通过对CuAg HNFs与Na_(2)PdCl_(4)进行电偶置换,除去了Ag和Cu,引入了零价的Pd,并在纳米片上形成了大量孔隙。我们对这些CuAg电催化剂进行了CO_(2)RR测试,结果显示Pd_(0.7)Cu_(40.0)Ag_(59.7)PHNs在C_(2+)产物选择性(69.5%)和C_(2+)分电流密度(-349.1mA·cm^(-2))方面表现出最佳性能。密度泛函理论(DFT)模拟表明,PdAgCu表面具有独特的电子性质,降低了C-C偶联反应的能垒,凸显了Pd掺杂对CuAg电催化剂CO_(2)还原的卓越性能。本研究为基于多孔纳米薄片构建多层次多金属纳米结构提供了一种直观方法,并验证了其在电催化方面的结构优势,为高效的CO_(2)RR催化剂的合理设计提供了依据。

DNA G-Quadruplexes as Targets for Natural Product Drug Discovery

DNA guanine(G)-quadruplexes(G4s)are unique secondary structures formed by two or more stacked Gtetrads in G-rich DNA sequences.These structures have been found to play a crucial role in highly transcribed genes,especially in cancer-related oncogenes,making them attractive targets for cancer therapeutics.Significantly,targeting oncogene promoter G4 structures has emerged as a promising strategy to address the challenge of undruggable and drug-resistant proteins,such as MYC,BCL2,KRAS,and EGFR.Natural products have long been an important source of drug discovery,particularly in the fields of cancer and infectious diseases.Noteworthy progress has recently been made in the discovery of naturally occurring DNA G4-targeting drugs.Numerous DNA G4s,such as MYC-G4,BCL2-G4,KRAS-G4,PDGFR-b-G4,VEGF-G4,and telomeric-G4,have been identified as potential targets of natural products,including berberine,telomestatin,quindoline,sanguinarine,isaindigotone,and many others.Herein,we summarize and evaluate recent advancements in natural and nature-derived DNA G4 binders,focusing on understanding the structural recognition of DNA G4s by small molecules derived from nature.We also discuss the challenges and opportunities associated with developing drugs that target DNA G4s.

RuO_(2)/CoMO_(2)O_(x) Catalyst with Low Ruthenium Loading for Long-Term Acidic Oxygen Evolution

We must urgently synthesize highly efficient and stable oxygen-evolution reaction(OER) catalysts for acidic media. Herein, we constructed a series of Ti mesh(TM)-supported RuO_(2)/CoMo_(y)O_(x) catalysts(RuO_(2)/CoMo_(y)O_(x)/TM) with heterogeneous structures. By optimizing the ratio of Co to Mo, RuO_(2)/CoMO_(2)O_(x)/TM with low Ru loading(0.079 mg/cm^(2)) achieves remarkable OER performance(η = 243 mV at 10 mA/cm^(2)) and high stability(300 h @ 10 mA/cm^(2)) in 0.5 mol/L H_(2)SO_(4) electrolyte. The activity of RuO_(2)/CoMo_yO_x/TM can be maintained for 50 h at 100 mA/cm^(2), and a water electrolyzer with RuO_(2)/CoMO_(2)O_(x)/TM as anode can operate for 40 h at 100 mA/cm~2, suggesting the remarkable OER durability of RuO_(2)/CoMo__(y)O__(x)/TM in acidic electrolyte. Owing to the heterogeneous interface between CoMO_(2)O_(x) and RuO_(2), the electronic structure of Ru atoms was optimized and electron-rich Ru was formed. With modulated electronic properties, the dissociation energy of H_(2)O is weakened, and the OER barrier is lowered. This study provides the design of low-cost noble metal catalysts with long-term stability in an acidic environment.

Assessment of the three representative empirical models for zenith tropospheric delay(ZTD)using the CMONOC data

The precise correction of atmospheric zenith tropospheric delay(ZTD)is significant for the Global Navigation Satellite System(GNSS)performance regarding positioning accuracy and convergence time.In the past decades,many empirical ZTD models based on whether the gridded or scattered ZTD products have been proposed and widely used in the GNSS positioning applications.But there is no comprehensive evaluation of these models for the whole China region,which features complicated topography and climate.In this study,we completely assess the typical empirical models,the IGGtropSH model(gridded,non-meteorology),the SHAtropE model(scattered,non-meteorology),and the GPT3 model(gridded,meteorology)using the Crustal Movement Observation Network of China(CMONOC)network.In general,the results show that the three models share consistent performance with RMSE/bias of 37.45/1.63,37.13/2.20,and 38.27/1.34 mm for the GPT3,SHAtropE and IGGtropSH model,respectively.However,the models had a distinct performance regarding geographical distribution,elevation,seasonal variations,and daily variation.In the southeastern region of China,RMSE values are around 50 mm,which are much higher than that in the western region,approximately 20 mm.The SHAtropE model exhibits better performance for areas with large variations in elevation.The GPT3 model and the IGGtropSH model are more stable across different months,and the SHAtropE model based on the GNSS data exhibits superior performance across various UTC epochs.

Music-stylized hierarchical dance synthesis with user control

Background Synthesizing dance motions to match musical inputs is a significant challenge in animation research.Compared to functional human motions,such as locomotion,dance motions are creative and artistic,often influenced by music,and can be independent body language expressions.Dance choreography requires motion content to follow a general dance genre,whereas dance performances under musical influence are infused with diverse impromptu motion styles.Considering the high expressiveness and variations in space and time,providing accessible and effective user control for tuning dance motion styles remains an open problem.Methods In this study,we present a hierarchical framework that decouples the dance synthesis task into independent modules.We use a high-level choreography module built as a Transformer-based sequence model to predict the long-term structure of a dance genre and a low-level realization module that implements dance stylization and synchronization to match the musical input or user preferences.This novel framework allows the individual modules to be trained separately.Because of the decoupling,dance composition can fully utilize existing high-quality dance datasets that do not have musical accompaniments,and the dance implementation can conveniently incorporate user controls and edit motions through a decoder network.Each module is replaceable at runtime,which adds flexibility to the synthesis of dance sequences.Results Synthesized results demonstrate that our framework generates high-quality diverse dance motions that are well adapted to varying musical conditions and user controls.

磺酰腙的高效快速合成及其抗菌性能初探——推荐一个医学本科院校化学创新实验

在有机化学实验教学过程中,实验内容通常是完成某一化合物的合成或提取,缺少对目标化合物的结构鉴定和性质检验。为了提高有机化学实验教学质量,培养学生的科研素养和创新能力。以商业易得的醛、酮和对甲苯磺酰肼为反应原料,于室温无溶剂条件下,利用研磨方法在1 min内高效快速合成磺酰腙,并对产物进行结构表征和性质研究。产物应用于抗菌实验研究时,化合物3i和3h对大肠杆菌有最好的抑制效果。实验涉及合成、TLC检测和柱色谱层析等操作,可以锻炼学生在有机化合物合成、纯化及结构鉴定等方面的操作技能。要求学生独立查阅文献,熟练掌握Origin、ChemDraw和MestRec等软件的使用,可以提升学生分析问题并解决问题的能力。改进的实验以提高学生综合素质为宗旨,适用于有机化学基础实验教学。

Cerebral venous sinus thrombosis presenting with subarachnoid hemorrhage and intracerebral hemorrhage:a case report

Objective:To explore the clinical and pathological characteristics of cerebral venous sinus thrombosis(CVST)with subarachnoid hemorrhage(SAH)and intracerebral hemorrhage(ICH),and to investigate the diagnosis,radiographic changes,and prognosis over the course of treatment.Methods:The clinical data and radiographic findings of a young male CVST patient,who presented with initial symptoms of SAH and ICH,were collected and analyzed.The relevant literature was also reviewed.Results:The patient had no specific clinical symptoms except for headache.The brain computed tomography(CT)scan revealed SAH,a high-density shadow in the right posterior fossa and cerebellar hemisphere,and ICH in the left frontal lobe.Magnetic resonance venography(MRV)further revealed bilateral thrombosis in the transverse and sigmoid sinuses.Conclusion:CVST with SAH and ICH is rare and difficult to diagnose.Careful radiological study and clinical analysis are important for the correct and early diagnosis of this condition.Anticoagulation therapy is considered the primary treatment for CVST.

Broadband all-fiber optical phase modulator based on photo-thermal effect in a gas-filled hollow-core fiber

We report broadband all-fiber optical phase modulation based on the photo-thermal effect in a gas-filled hollow-core fiber.The phase modulation dynamics are studied by multi-physics simulation.A phase modulator is fabricated using a 5.6-cm-long anti-resonant hollow-core fiber with pure acetylene filling.It has a half-wave optical power of 289 mW at 100 kHz and an average insertion loss 0.6 dB over a broad wavelength range from 1450 to 1650 nm.The rise and fall time constants are 3.5 and 3.7μs,respectively,2–3 orders of magnitude better than the previously reported microfiber-based photo-thermal phase modulators.The gas-filled hollow-core waveguide configuration is promising for optical phase modulation from ultraviolet to mid-infrared which is challenging to achieve with solid optical fibers.

The high-quality sequencing of the Brassica rapa‘XiangQingCai’genome and exploration of genome evolution and genes related to volatile aroma

‘Vanilla’(XQC,brassica variety chinensis)is an important vegetable crop in the Brassica family,named for its strong volatile fragrance.In this study,we report the high-quality chromosome-level genome sequence of XQC.The assembled genome length was determined as 466.11 Mb,with an N50 scaffold of 46.20 Mb.A total of 59.50%repetitive sequences were detected in the XQC genome,including 47570 genes.Among all examined Brassicaceae species,XQC had the closest relationship with B.rapa QGC(‘QingGengCai’)and B.rapa Pakchoi.Two whole-genome duplication(WGD)events and one recent whole-genome triplication(WGT)event occurred in the XQC genome in addition to an ancient WGT event.The recent WGT was observed to occur during 21.59-24.40 Mya(after evolution rate corrections).Our findings indicate that XQC experienced gene losses and chromosome rearrangements during the genome evolution of XQC.The results of the integrated genomic and transcriptomic analyses revealed critical genes involved in the terpenoid biosynthesis pathway and terpene synthase(TPS)family genes.In summary,we determined a chromosome-level genome of B.rapa XQC and identified the key candidate genes involved in volatile fragrance synthesis.This work can act as a basis for the comparative and functional genomic analysis and molecular breeding of B.rapa in the future.

Drying kinetics of soy protein isolate-corn starch film during preparation and its moisture adsorption characteristics during storage

To better understand the mass transfer process of moisture in the soy protein isolate-corn starch(SPI-CS)films during preparation and storage process,the drying kinetics model of SPI-CS films with different formation conditions during the drying process and the moisture adsorption characteristics of the SPI-CS films under different humidity conditions were investigated.Within the range of experimental conditions,the moisture migration rule in the SPI-CS films during the drying preparation was combined with the Page model which was expressed as MR=exp(-kt^(n)).It was found that the adsorption equilibrium needed shorter time(about 3 h)when the SPI-CS films existed in the environment with lower humidity(RH<54%).Additionally,the secondorder adsorption kinetic equation was successful to describe the moisture adsorption characteristic of the SPICS films during storage under different humidity conditions.

Doping of group IVB elements for nickel-rich cobalt-free cathodes

Hetero-element doping is a promising strategy to improve the cycling stability of nickel-rich cobalt-free cathodes for the next-generation high energy-density Li ion batteries.To make doping effective,it is important to understand the mechanism of how the dopants regulate the electronic band,lattice parameter adjusting,or hetero-phase formation to achieve high stability.In this study,we investigate LiNi_(0.9)Mn_(0.1)O_(2)cathodes doped with IVB grouping elements via multiple characterization techniques.By utilizing in situ XRD and TEM methods,we found that the stronger Ti-O bond effectively improves the cathode stability via a dual protection mechanism.Specifically,the bulk lattice of cathode is wellpreserved during cycling as a result of the suppressed H_(2)-H_(3)phase transition,while a in situ formed Ti-rich surface layer can prevent continuous surface degradation.As a result,the 5%Ti doped LiNi_(0.9)Mn_(0.1)O_(2)cathode exhibits a high capacity retention of 96%after 100 cycles.Whereas,despite IVB group elements Zr and Hf have stronger bonding energy with oxygen,their larger ionic radii actually impede their diffusion into the cathode,thereby they can not improve the cycling stability.Our findings uncover the functional origin of doped elements with their dynamic modification on cathode structure,providing mechanistic insights into the design of nickel-rich cobalt-free cathodes.

The parallel biosynthesis routes of hyperoside from naringenin in Hypericum monogynum

Hyperoside is a bioactive flavonoid galactoside in both medicinal and edible plants.It plays an important physiological role in the growth of flower buds.However,the hyperoside biosynthesis pathway has not been systematically elucidated in plants,including its original source,Hypericaceae.Our group found abundant hyperoside in the flower buds of Hypericum monogynum,and we sequenced its transcriptome to study the biosynthetic mechanism of hyperoside.After gene screening and functional verification,four kinds of key enzymes were identified.Specifically,HmF3Hs(flavanone 3-hydroxylases)and HmFLSs(flavonol synthases)could catalyze flavanones into dihydroflavonols,as well as catalyzing dihydroflavonols into flavonols.HmFLSs could also convert flavanones into flavonols and flavones with varying efficiencies.HmF3′H(flavonoid 3′-hydroxylase)was found to act broadly on 4′-hydroxyl flavonoids to produce 3′,4′-diydroxylated flavanones,dihydroflavonols,flavonols,and flavones.HmGAT(flavonoid 3-O-galactosyltransferase)would transform flavonols into the corresponding 3-O-galactosides,including hyperoside.The parallel hyperoside biosynthesis routes were thus depicted,one of which was successfully reconstructed in Escherichia coli BL21(DE3)by feeding naringenin,resulting in a hyperoside yield of 25 mg/l.Overall,this research not only helped us understand the interior catalytic mechanism of hyperoside in H.monogynum concerning flower development and bioactivity,but also provided valuable insights into these enzyme families.

Multi-Path Attention Inverse Discrimination Network for Offline Signature Verification

Signature verification,which is a method to distinguish the authenticity of signature images,is a biometric verification technique that can effectively reduce the risk of forged signatures in financial,legal,and other business envir-onments.However,compared with ordinary images,signature images have the following characteristics:First,the strokes are slim,i.e.,there is less effective information.Second,the signature changes slightly with the time,place,and mood of the signer,i.e.,it has high intraclass differences.These challenges lead to the low accuracy of the existing methods based on convolutional neural net-works(CNN).This study proposes an end-to-end multi-path attention inverse dis-crimination network that focuses on the signature stroke parts to extract features by reversing the foreground and background of signature images,which effectively solves the problem of little effective information.To solve the problem of high intraclass variability of signature images,we add multi-path attention modules between discriminative streams and inverse streams to enhance the discriminative features of signature images.Moreover,a multi-path discrimination loss function is proposed,which does not require the feature representation of the samples with the same class label to be infinitely close,as long as the gap between inter-class distance and the intra-class distance is bigger than the set classification threshold,which radically resolves the problem of high intra-class difference of signature images.In addition,this loss can also spur the network to explore the detailed infor-mation on the stroke parts,such as the crossing,thickness,and connection of strokes.We respectively tested on CEDAR,BHSig-Bengali,BHSig-Hindi,and GPDS Synthetic datasets with accuracies of 100%,96.24%,93.86%,and 83.72%,which are more accurate than existing signature verification methods.This is more helpful to the task of signature authentication in justice and finance.

英汉否定性违实条件句的对比研究

否定性违实条件句(negative counterfactuals,简称NC)是一类特殊的违实条件句,在自然语言中普遍存在。以往的研究偏重考察这类条件句的共性,而忽视了其在不同语言中的差异性。本文从形式语言学的视角对比了英汉两种语言中的NC条件句,发现两者在句法、语义和语用方面均有所不同:句法上,“要不是”NC中的否定词“不是”既不是低位否定,也不是高位否定,整个结构不能像“if not for”NC条件句那样做拆解性分析,应看成一个构式;语义上,相比“if not for”NC条件句,“要不是”NC条件句除了表达因果关系且预设其前件为真,还预设其后者为假,不支持多个原因导致相同结果情况下的因果推理;语用上,“要不是”NC条件句表达独特的使用条件意义,即要求其中的因果关联对说话者产生影响,一般不能用于分析性推理和科学文本中的因果推理,而“if not for”条件句不受此限制。

城市再开发背景下的社区感知——基于内隐联想测验的研究

以广州市永庆坊为例,研究采用内隐联想测验法、问卷以及质性访谈相结合的方法,探究其改造前后社区相关主体的社区感知,旨在探讨社区空间变化背后相关主体的感知态度差异。研究结果揭示了社区感知的外显态度和内隐态度的分离效应,且外显态度表现的差异性强于内隐态度。参与者对永庆坊改造前后的连贯性和积极性存在外显感知态度的显著差异,在内隐态度结果上,参与者对永庆坊改造前后的连贯性和积极性并未存在显著差异。实验结果表明:物质层面的更新并非引起居民等主体对改造热议的根本原因,社区更新重点应关注利益主体对权利、参与权的诉求,关注其利益分配的合理性。诚然,社区改造规划中不仅应重视公众参与和调查,也应深入挖掘社区公众对于社区改造的内隐感知态度,以提高社区规划的效力。研究采用内隐联想测验的神经科学认知方法对景观感知的探讨,以期开拓人文地理学研究方法神经科学转向的新方向。

Bioinformatics Analysis Revealed Potential Tumor Suppressors (KLF4/CGN), Oncogenes (SHH/LIF) and Biomarkers of Asian Stomach Adenocarcinoma

Stomach adenocarcinoma (STAD) is the fifth most prevalent cancer and the third leading cause of cancer-related death in the world and is more common in Asia than in most Western countries. There is an urgent need to identify potential novel oncogenes and tumor suppressor genes, and biomarkers for STAD. 6652 differentially expressed genes were identified between STAD and normal samples based on the transcriptome data analysis of the TCGA and GEO databases. 13 key modules were identified in STAD by WGCNA analysis. 293 potential STAD associated genes were identified from intersection by Venn Diagram. The 293 intersected genes were enriched in cell cortex and infection by GO and KEGG analysis. 10 hub genes were identified from PPI and Cytoscape analyses of the intersected genes. KLF4/CGN low and SHH/LIF high expression were associated with short overall survival of Asian STAD patients. Bioinformatics analysis revealed potential novel tumor suppressors (KLF4/CGN), oncogenes (SHH/LIF) and biomarkers for diagnosis, therapy and prognosis of STAD, specifically for Asian patients.

Novel Functional Motifs of the Cell Entry Glycoprotein D for Oncolytic Herpes Simplex Viruses

Background: Oncolytic herpes simplex virus (oHSV) have been proved effective and safe to treat tumors. Glycoprotein D (gD) has been engineered for targeting cancer cells and de-targeting normal cells successfully, however, the effectiveness and safety of oHSVs still need to be improved. Method: Here we sequenced the DNA encoding gD of our recently isolated new strain HSV-1-LXMW and compared the gD amino acid sequence with the gDs of other 7 HSV-1 and 3 HSV-2 strains. Results: Phylogenetic analysis revealed that HSV-1-LXMW is evolutionarily close to HSV-1-Patton and -KOS strains. The gD amino acid sequence alignment identified 19 conserved and 8 variable regions. We further predicted 10 new motifs in HSV gD for the first time and identified motif differences in HSV-1 and HSV-2. We summarized the gD-engineered oHSVs and found that some of the newly identified gD motifs are actually functional. Conclusion: Our results shed light on HSV gD biology and provided new directions for future gD functional studies and engineering in order to make better oHSVs.

多主体视阈下的PPP项目运作逻辑——基于基础设施和公共服务项目的多案例研究

PPP项目作为基础设施和公共服务供给的创新模式得到推广,然而当前研究忽略了PPP项目运作的多主体互动行为。论文基于21个案例和参与式观察资料,归纳提炼出多主体视阈下的PPP项目运作逻辑,包括中央部委竞争发包、地方政府按揭打包和大型企业混合抓包。研究发现:PPP项目运作本应兼顾融资和提高产出效率等目标,然而,中央政府监管冲突和滞后,地方政府重当期融资、轻远期产出,以及大型企业重投资建设、轻资产运营等问题导致PPP项目运作中对融资技术选择性执行,引发了融资异化、债务增量和产出偏差等诸多问题。论文揭示的PPP项目运作逻辑,反映了中国项目化运作中统一监管和技术特性的张力。建议在PPP项目领域加强技术培训,统一标准,提高项目监管的信息化水平,区分不同行业的适用范围及准入条件等。

Characterization and mapping of QTLs on chromosome 2D for grain size and yield traits using a mutant line induced by EMS in wheat

Production of mutants with altered phenotypes is a powerful approach for determining the biological functions of genes in an organism. In this study, a high-grain-weight mutant line M8008 was identified from a library of mutants of the common wheat cultivar YN15 treated with ethylmethane sulfonate(EMS). F2 and F2:3generations produced from crosses of M8008 × YN15(MY) and M8008 × SJZ54(MS) were used for genetic analysis. There were significant differences between M8008 and YN15 in plant height(PH), spike length(SL),fertile spikelet number per spike(FSS), grain width(GW), grain length(GL), GL/GW ratio(GLW), and thousand-grain weight(TGW). Most simple correlation coefficients were significant for the investigated traits, suggesting that the correlative mutations occurred in M8008. Approximately 21% of simple sequence repeat(SSR) markers showed polymorphisms between M8008 and YN15, indicating that EMS can induce a large number of mutated loci. Twelve quantitative trait loci(QTLs) forming QTL clusters(one in MY and two in MS) were detected. The QTL clusters coinciding with(MY population) or near(MS population) the marker wmc41 were associated mainly with grain-size traits, among which the M8008 locus led to decreases in GW, factor form density(FFD), and TGW and to increases in GLW. The cluster in the wmc25–barc168 interval in the MS population was associated with yield traits, for which the M8008 locus led to decreased PH, spike number per plant(SN), and SL.

The SOLIDS 6G Mobile Network Architecture:Driving Forces,Features,and Functional Topology

With the large-scale commercial launch of fifth generation(5G)mobile network,the development of new services and applications catering to the year 2030,along with the deep convergence of information,communication,and data technologies(ICDT),and the lessons and experiences from 5G practice will drive the evolution of the next generation of mobile networks.This article surveys the history and driving forces of the evolution of the mobile network architecture and proposes a logical function architecture for sixth generation(6G)mobile network.The proposed 6G network architecture is termed SOLIDS(related to the following basic features:soft,on-demand fulfillment,lite,native intelligence,digital twin,and native security),which can support self-generation,self-healing,self-evolution,and self-immunity without human involvement and address the primary issues in the legacy 5G network(e.g.,high cost,high power consumption,and highly complicated operation and maintenance),significantly well.