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。

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.

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 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.

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.

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.

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.

Weaving 3D highly conductive hierarchically interconnected nanoporous web by threading MOF crystals onto multi walled carbon nanotubes for high performance Li-Se battery

Lithium-selenium(Li-Se)battery has attracted growing attention.Nevertheless,its practical application is still impeded by the shuttle effect of the formed polyselenides.Herein,we report in-situ hydrothermal weaving the three-dimensional(3 D)highly conductive hierarchically interconnected nanoporous web by threading microporous metal organic framework MIL-68(Al)crystals onto multi-walled carbon nanotubes(MWCNTs).Such 3 D hierarchically nanoporous web(3 D MIL-68(Al)@MWCNTs web)with a very high surface area,a large amount of micropores,electrical conductivity and elasticity strongly traps the soluble polyselenides during the electrochemical reaction and significantly facilitates lithium ion diffusion and electron transportation.Molecular dynamic calculation confirmed the strong affinity of MIL-68(Al)for the adsorption of polyselenides,quite suitable for Li-Se battery.Their hexahedral channels(1.56 nm)are more efficient for the confinement of polyselenides and for the diffusion of electrolytes compared to their smaller triangular channels(0.63 nm).All these excellent characteristics of 3 D MIL-68(Al)@MWCNTs web with suitable confinement of a large amount of selenium and the conductive linkage between MIL-68(Al)host by MWCNTs result in a high capacity of 453 m Ah/g at 0.2 C with 99.5%coulombic efficiency after 200 cycles with significantly improved cycle stability and rate performance.The 3 D MIL-68(Al)@MWCNTs web presents a good performance in Li-Se battery in term of the specific capacity and cycling stability and also in terms of rate performance compared with all the metal-organic framework(MOF)based or MOF derived porous carbons used in Li-Se battery.

血清同型半胱氨酸和血清胱抑素C水平与化疗疗效的相关性研究

目的:探讨血清同型半胱氨酸(homocysteine,Hcy)、血清胱抑素C(cysatin C,Cys-C)在小细胞肺癌(small cell lung cancer,SCLC)外周血中的水平及与化疗疗效的相关性。方法:选取2018年1月至2020年12月于陕西中医药大学附属医院治疗的无法手术的SCLC患者67例(观察组)及同期体检者60例(对照组)。观察组患者局限期26例,广泛期41例,分别于化疗前及依托泊苷联合铂类2周期化疗后,清晨空腹抽取静脉血,检测Hcy、Cys-C水平,并进行分析。结果:观察组患者外周血Hcy水平显著高于对照组(P<0.05),而观察组与对照组Cys-C差异无统计学意义(P>0.05);局限期与广泛期Hcy、Cys-c水平差异无统计学意义(P>0.05);局限期、广泛期分别与对照组相比,Hcy值均显著升高(均P<0.05),而Cys-C差异无统计学意义(P>0.05);有效组患者化疗后Hcy、Cys-C水平较化疗前均显著下降(均P<0.05),无效组患者化疗后Hcy、Cys-C水平较化疗前差异无统计学意义(均P>0.05)。结论:Hcy与SCLC的发生呈正相关,血清Hcy、Cys-C联合检测,可以评估SCLC患者化疗疗效,观察患者病情动态变化。

VPS4B mutation impairs the osteogenic differentiation of dental follicle cells derived from a patient with dentin dysplasia type I

A splicing mutation in VPS4B can cause dentin dysplasia type I(DD-I),a hereditary autosomal-dominant disorder characterized by rootless teeth,the etiology of which is genetically heterogeneous.In our study,dental follicle cells(DFCs)were isolated and cultured from a patient with DD-I and compared with those from an age-matched,healthy control.In a previous study,this DD-I patient was confirmed to have a loss-of-function splicing mutation in VPS4B(IVS7+46C>G).The results from this study showed that the isolated DFCs were vimentin-positive and CK14-negative,indicating that the isolated cells were derived from the mesenchyme.DFCs harboring the VPS4B mutation had a significantly higher proliferation rate from day 3 to day 8 than control DFCs,indicating that VPS4B is involved in cell proliferation.The cells were then replenished with osteogenic medium to investigate how the VPS4B mutation affected osteogenic differentiation.Induction of osteogenesis,detected by alizarin red and alkaline phosphatase staining in vitro,was decreased in the DFCs from the DD-I patient compared to the control DFCs.Furthermore,we also found that the VPS4B mutation in the DD-I patient downregulated the expression of osteoblast-related genes,such as ALP,BSP,OCN,RUNX2,and their encoded proteins.These outcomes confirmed that the DD-I-associated VPS4B mutation could decrease the capacity of DFCs to differentiate during the mineralization process and may also impair physiological root formation and bone remodeling.This might provide valuable insights and implications for exploring the pathological mechanisms underlying DD-I root development.

Species Diversity and Elevational Distribution of Amphibians in the Xianxialing and Wuyishan Mountain Ranges,Southeastern China

The species diversity and altitudinal distribution of amphibians along an eleva tional gradient of 200-1600 m in the Xianxialing and Wuyishan Mountain Ranges in Southeastern China were investiga ted through time-constra ined visual surveys along 32 transect lines in 9 survey areas,in which the ha bitat types were also recorded.A total of 27 amphibian species belonging to 19 genera,7 families,and 2 orders were found.The species diversity of the amphibians plateaued at low elevation,and the altitudinal boundary of their distribution was at 800 m.Their species compositions were dissimilar in the two mountain ranges probably beca use the annual average temperature and annual rainfall were different in both areas.The eleva tional Rapoport's rule demonstrated that the species range size of the amphibians expanded as the elevation increased in both mountain ranges.The results of the cross species method supported the rule only when the influence of the low-frequency occurrence proba bility of an investigated species was excluded,whereas those of the Steven's method strongly corroborated the rule rega rdless of the incidental occurrence or absence of the species.

Three-dimensional ordered hierarchically porous carbon materials for high performance Li-Se battery

Developing host materials with high specific surface area, good electron conductivity, and fast ion transportation channel is critical for high performance lithium-selenium(Li-Se) batteries. Herein, a series of three dimensional ordered hierarchically porous carbon(3D OHPC) materials with micro/meso/macropores are designed and synthesized for Li-Se battery. The porous structure is tuned by following the concept of the generalized Murray’s law to facilitate the mass diffusion and reduce ion transport resistance.The optimized 3D Se/OHPC cathode exhibits a very high 2 nd discharge capacity of 651 m Ah/g and retains 361 m Ah/g after 200 cycles at 0.2 C. Even at a high current rate of 5 C, the battery still shows a discharge capacity as high as 155 m Ah/g. The improved electrochemical performance is attributed to the synergy effect of the interconnected and well-designed micro, meso and macroporosity while shortened ions diffusion pathways of such Murray materials accelerate its ionic and electronic conductivities leading to the enhanced electrochemical reaction. The diffusivity coefficient in Se/OHPC can reach a very high value of 1.3 × 10^(-11)cm^(2)/s, much higher than those in single pore size carbon hosts. Their effective volume expansion accommodation capability and reduced dissolution of polyselenides ensure the high stability of the battery. This work, for the first time, established the clear relationship between textural properties of cathode materials and their performance and demonstrates that the concept of the generalized Murray’s law can be used as efficient guidance for the rational design and synthesis of advanced hierarchically porous materials and the great potential of 3D OHPC materials as a practical high performance cathode material for Li-Se batteries.

Synergistic effects of carbon doping and coating of TiO_(2) with exceptional photocurrent enhancement for high performance H2 production from water splitting

The"one pot"simultaneous carbon coating and doping of TiO_(2) materials by the hydrolysis of TiCl4 in fructose is reported.The synergistic effect of carbon doping and coating of TiO_(2) to significantly boost textural,optical and electronic properties and photocurrent of TiO_(2) for high performance visible light H2 production from water splitting has been comprehensively investigated.Carbon doping can significantly increase the thermal stability,thus inhibiting the phase transformation of the Titania material from anatase to rutile while carbon coating can suppress the grain aggregation of TiO_(2).The synergy of carbon doping and coating can not only ensure an enhanced narrowing effect of the electronic band gap of TiO_(2) thus extending the absorption of photocatalysts to the visible regions,but also promote dramatically the separation of electron-hole pairs.Owing to these synergistic effects,the carbon coated and doped TiO_(2) shows much superior photocatalytic activity for both degradation of organics and photocatalytic/photoelectro chemical(PEC)water splitting under simulated sunlight illumination.The photocatalytic activity of obtained materials can reach 5,4 and 2 times higher than that of pristine TiO_(2),carbon doped TiO_(2) and carbon coated TiO_(2),respectively in the degradation of organic pollutants.The carbon coated and doped TiO_(2) materials exhibited more than 37 times and hundreds of times photocurrent enhancement under simulated sunlight and visible light,respectively compared to that of pristine TiO_(2).The present work providing new comprehensive understanding on carbon coating and doping effect could be very helpful for the development of advanced TiO_(2) materials for a large series of applications.