主动和被动吸烟对多发性硬化和视神经脊髓炎临床病程的影响

目的:主动吸烟和被动吸烟是常见的环境危险因素,但它们对多发性硬化(MS)和视神经脊髓炎谱系障碍(NMOSD)复发和残疾进展的影响尚无确切结论。多发性硬化和视神经脊髓炎是两种常见的中枢神经系统脱髓鞘疾病,本研究旨在调查主动和被动吸烟对这两种疾病复发和残疾进展的影响。方法:这是一项回顾性队列研究,患者来自四个中心。人口统计学和临床数据从临床数据库中提取,而涉及日常生活中环境暴露、复发和残疾进展的数据通过电话随访访谈获得。Cox比例风险回归模型用于评估复发的影响,多因素线性回归模型用于评估残疾进展。使用Kaplan-Meier生存曲线估计首次发作后五年内患者的复发情况。结果:本研究共纳入130名MS患者和318名NMOSD患者,女性分别占60%和79.6%。有主动吸烟史的MS患者复发风险更高,在控制协变量后,这种关联变得临界显著(aHR=1.52,95%CI=1.00,2.31;p=0.052)。每天吸烟超过10支的患者和每天吸烟少于10支的患者之间复发风险没有统计学差异(aHR=0.96,95%CI=0.63,1.47;p=0.859)。然而,与从未接触过被动吸烟的患者相比,接触被动吸烟与MS复发风险降低相关(aHR=0.75,95%CI=0.56,1.00;p=0.044)。主动吸烟/被动吸烟与NMOSD复发风险之间没有关联,但有吸烟史的患者扩展残疾状态评分EDSS(aβ=-0.20,95%CI=-0.38,-0.01;p=0.036)和多发性硬化严重程度评分MSSS(aβ=-0.23,95%CI=-0.44,-0.03;p=0.028)的年度进展率较低。结论:我们的研究表明,主动吸烟会增加MS的复发风险,并对患者残疾进展有负面影响,应鼓励患者发病后戒烟。

Al(CF_3SO_3)_3催化选择性氧化甘油转化为甲酸（英文）

化石能源的日渐紧缺以及在使用过程中带来的环境污染引起了世界范围内学术界和工业界的密切关注,而生物柴油作为一种环境友好的可再生资源,可以替代化石能源,具有非常好的发展前景.虽然生物柴油生产过程中会产生大量甘油副产物,但是甘油也是一种重要的生物质平台分子,可用于生产多种高附加值的化学品.为了提高甘油的利用价值,同时探索一条高产率制备甲酸的可替代路径,本文研究了一个在较温和条件下,以三氟甲磺酸盐为催化剂,过氧化氢为氧化剂,将甘油选择性氧化为甲酸和乙醇酸的催化体系.结果表明,金属阳离子的催化活性与它们的水解常数(Kh)和内含水配体取代的交换速率常数(水交换速率常数, WERC)之间存在密切的相关性,适当的水解常数和较高的水交换速率常数有利于甘油氧化反应.在考察的多种金属三氟甲磺酸盐中,三氟甲磺酸铝(Ⅲ)是甘油选择性氧化为甲酸最有效的催化剂.在温度为70°C,反应12 h的条件下,甲酸收率可达72%.另外,反应体系中甘油、催化剂和H_2O_2的比例对甘油氧化产物分布有一定影响.一系列实验研究表明,催化体系中产生的Lewis酸和Br?nsted酸存在协同作用,具有适当Lewis酸和Br?nsted酸比例的金属盐呈现出良好的催化性能,催化剂过度水解可降低其催化活性.Al(OTf)_3原位水解过程中产生的Lewis酸性物种[Al(OH)_x]^(n+)和Br?nsted酸物种CF_3SO_3H是催化甘油转化的活性中心,另外在H_2O_2存在下产生的Al过氧物种可能是甘油氧化的活性中心.反应动力学和~1H NMR研究表明,在甘油转化为甲酸的过程中,甘油酸、乙醇酸和乙酸可能是反应的中间产物,可以继续氧化转化为甲酸.该催化剂体系同样适用于其他生物平台分子选择性氧化转化为有机羧酸,并且能够在甘油氧化反应中多次循环使用.Al(OTf)_3作为简单易得的催化剂具有高效的催化性能和优异的循环使用性能,这将为甘油选择性氧化转化为高附加值产品开辟一种新的方法.

新时代青藏地区民族职业教育定位及实践路向探析

青藏地区职业教育的精准定位和有效发展对实现民族地区长治久安和打牢青藏地区各族师生中华民族共同体意识有着基础性意义,同时加快发展民族地区中高等职业教育是进入新时代后国务院加快发展民族教育的重大决定之一。但由于历史、自然等原因青藏地区职业教育发展面临着一些特殊困难和突出问题。为了有效推进青藏地区职业教育跨越式发展,需要从培养国家认同的合格公民、扎根高原的技术技能型人才、培养民族文化传承和创新者来把握其功能定位,围绕定位开设宪法教育与公民教育课程;基于高原产业的产教融合;民族文化产业开发与传承的职业教育人才培养的实践阔步迈进。

Structural Characterization of Glucan Produced by Lactobacillus sake L-7 from Sausage

A linear glucan was produced by Lactobacillus sake L-7 isolated from homemade sausage. Cultivation of the strain in Man–Rogosa–Sharpe(MRS) medium containing 50 g/L sucrose yielded 5.3 g/L of purified exopolysaccharide(EPS). The EPS was characterized by gas chromatography(GC), Fourier-transform infrared(FT-IR) spectroscopy, high-performance sizeexclusion chromatography(HPSEC), nuclear magnetic resonance(NMR) spectroscopy, and scanning electron microscopy(SEM). The monosaccharide composition of the EPS was glucose, and its molecular weight was 1 × 10~7 Da. The FT-IR and NMR spectra revealed that the L-7 EPS was a linear glucan with α-(1 → 6) glucosidic bonds. SEM images of the dried EPS revealed a hollow tubular structure. The water solubility index and water holding capacity of L-7 EPS were 96 and 272%, respectively. The results of hydrolysis indicated that L-7 EPS was not susceptible to hydrolysis by physiological barriers and can be used as a soluble dietary fiber with health benefits. All these characteristics suggest that L-7 EPS might have potential applications in the food, cosmetic, and pharmaceutical industries.

Isolation, Purification, and Characterization of Exopolysaccharide Produced by Leuconostoc Citreum N21 from Dried Milk Cake

A strain with high production of exopolysaccharide(EPS) was isolated from dried milk cake(a traditional fermented food from Inner Mongolia). The strain was called N21 and later identified as Leuconostoc citreum( Leu. citreum). The strain was cultured in Man-Rogosa-Sharpe medium containing 50 g/L of sucrose for 48 h at 30 °C and the EPS purified, with a yield of 24.5 g/L. An average molecular weight of 6.07 × 10~6 g/mol was determined by high-performance size-exclusion chromatography. The structure of the purified EPS was investigated through gas chromatography, ~1H and ^(13)C nuclear magnetic resonance spectroscopy, and Fourier transform infrared spectroscopy. The results demonstrated a polysaccharide composed of D-glucopyranose units in a linear chain with consecutive α(1 → 6) linkages. No branching was found in the structure of the exopolysaccharide. The purified EPS showed high water solubility and emulsibility. Based on the thermogravimetric curve, the degradation temperature of the EPS was 308.47 °C, which suggested that the dextran in the study exhibited high thermal stability. The results indicated that Leu. citreum N21 could be widely used to produce linear EPS and that the EPS has potential applications in food science and processing as a food additive.

Vicinal hydroxyl group-inspired selective oxidation of glycerol to glyceric acid on hydroxyapatite supported Pd catalyst

Selective oxidation of glycerol provides a feasible route towards the sustainable synthesis of high value-added chemicals.Herein,the hydroxyapatite(HAP)supported palladium(Pd)species were fabricated by impregnation and subsequent calcination.The as-obtained heterogeneous Pd catalyst afforded not only excellent selectivity to glyceric acid(GLA)up to 90%with 59%conversion of glycerol but also good recyclability by using molecular oxygen as an oxidant under mild conditions.The characterization of catalysts indicated that both the surface basicity and Pd sites on the catalyst played a crucial role in promoting glycerol oxidation.Notably,it demonstrated that the presence of the vicinal hydroxyl group of glycerol molecule can assist the oxidation reaction via forming a coordination between the vicinal hydroxyl group and Ca^(2+) sites on HAP-derived catalysts.In this catalytic process,the secondary hydroxyl of glycerol kept untouched and the primary hydroxyl of glycerol was converted into carboxyl group,while the Pd species acted as active centers for cooperatively promoting the subsequent oxidation to generate GLA.Additionally,this catalytic system can be extended widely for the oxidative conversion of other vicinal diols into the corresponding a-hydroxycarboxylic acids selectively.Isotope labeling experiment using H_(2)^(18)O confirmed that H_(2)O not only acted as solvent but also was involved in the catalytic cycles.On the basis of the results,a possible reaction mechanism has been proposed.The HAP-supported Pd catalytic system has been shown to serve as an effective approach for the upgrading of bio-derived vicinal diols to high value-added chemicals.

Relationship between scores and tags for Chinese books—In the case of Douban Book

Purpose:Currently,social tagging behavior,including social tag,online review and score information,has been investigated extensively,however,there are very few works about the relationship among them.In this paper,we have investigated the problem using Douban Website as the research object.Design/methodology/approach:Firstly,we divided social tags into those with high and low frequency counts,respectively,divided books into popular and unpopular books according to books’popularity,and chose core tags in terms of distribution;Secondly,we conducted an investigation on the relationship between social tags and books scores including comprehensive analyses and assorted analyses.Findings:The more popular the books become,the higher scores they will get.Tag frequency is not related with book scores directly,and neither does the tag distribution weight.Tags in books of'fashion'category are relatively disordered,which may associate with books miscellany and readers diversity.Research limitations:Social tags are growing dramatically,strategies and researches to this respect are just experimental exploration.Open source books,data and educational resources are not consummate.Comparative studies are necessary,but the result may be affected by researches based on data analyses.In addition,this research has been conducted only on one website,namely Douban,and the tags provided by Douban Book are not complete.All these factors could influence the versatility of the results.Practical implications:There are very a few studies that have been conducted on the relationship between tags and scores,and this research could bring a certain practical significance to popular books prediction and tags’quality research.Originality/value:Less attention has been paid to Chinese books while analyzing relationship between scores and tags of user generated content.Analyses based on the Chinese books may fill in the gap of better understanding the relationship between the two objects.

壁面扰动对超声速湍流边界层拟序结构的影响研究

本文研究了壁面扰动对来流马赫数为2.0的超声速湍流边界层中相干结构和湍流输运的影响.通过对直接数值模拟数据的分析,本文讨论了与动量和热传输相关的物理量的瞬时分布和谱特性.研究发现,壁面扰动在增强动量和热传输方面发挥重要作用,其在近壁区域引起了与壁面扰动波长及其谐波长度尺度的能量湍流脉动.同时,壁面扰动也激发了大尺度运动,其长度尺度为湍流边界层厚度,这是由壁面扰动和某些尺度的湍流运动之间的非线性相互作用所致.壁面扰动还引起了较强的密度和压力脉动,通过改变声速面而穿透边界层,保持等熵的特性向自由流辐射.在此过程中,稳态壁面扰动被湍流扭曲,从而具有了多尺度和多频率的特征.

钼基碳掺杂二硫化钼电极的硫氧化反应性能

硫钝化是阻碍硫化物氧化反应(sulfur oxidation reaction,SOR)在硫锂电池、电化学脱硫、含硫污染物资源化等领域高效进行的重要因素.二硫化钼(MoS2)因其优异的抗硫性和可调的二维层状结构而具有良好的SOR潜能,但其本征半导体性质限制了电子传递过程.本文报道了一种抗硫性钼基碳掺杂二硫化钼电极(Mo/C-MoS2),通过碳掺杂使MoS2电极具有接近热中性的硫吸附吉布斯自由能和快速转换多硫化物的能力,有效避免了硫钝化.实验结果显示,Mo/C-MoS2能以0.37 V驱动SOR反应达到10 mA/cm2,低于Mo/MoS2电极(0.41 V)和Pt电极(0.68 V),并在恒电位电解测试中保持16.5 h的抗硫钝化稳定性.透射电子显微镜(transmission electron microscope,TEM)、X射线衍射(X-ray diffraction,XRD)、X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)、拉曼散射光谱表征证实,CMoS2具有1T导电相晶体结构,提升了催化反应速率.密度泛函理论(density functional theory,DFT)计算进一步阐明,碳掺杂增强了MoS2与Na2S之间的相互作用,促使元素硫向可溶性多硫化物转换,为Mo/C-MoS2电极高效SOR和稳定抗硫性的实验结论提供了理论支撑.

Canopy deposition characteristics of different orchard pesticide dose models

Pesticide dose model based on canopy characteristics is the guidance basis for spray parameters adjustment.In this study,the calculation formula and canopy deposition characteristics of leaf wall area(LWA)model,tree row volume(TRV)model,and optimal coverage method(OCM)model were described and compared.A tower air-assisted spray test bench was applied to provide fine quality droplets,suitable wind speed and demand spray flow rate for corresponding models,an electric flat board vehicle was applied to drive tree in a straight line to simulate the sprayer movement speed,and droplet deposition distribution were tested in different leaf area density canopy.The results showed that the spray flow rates of three pesticide dose models decreased gradually.LWA model was only related to canopy height,TRV model was related to canopy height and canopy diameter,while OCM model was related to canopy height,canopy diameter and leaf area density.Whether dense or sparse canopy,TRV model basically satisfied the requirement of coverage rate greater than 33%in the entire canopy,OCM model met the requirement of coverage density greater than 70 droplets/cm^(2).However,LWA model,for dense canopy,unit area deposition of outermost leaves near sprayer was 3.6 times of the apple leaf maximum retention,which had a high loss risk;for sparse canopy,penetration rates of outermost leaves far away sprayer,that is,the drift rate was 21.4%.The discussion leads to the conclusion that for conventional spraying,TRV model represented a substantial improvement compared to LWA model,and OCM model was a reasonable low volume spraying model.This study provides a reference to different growth seasons spray amount adjustments in orchard.

Chemical Protein Synthesis by Native Chemical Ligation and Variations Thereof

For a long time,the total synthesis of proteins was considered as a "mission impossible" because of the tedious and complex synthetic steps and de­manding purification processes.However,with the development of modern synthetic methodologies,many protein syntheses have now been reported.More importantly,through chemical synthesis,desired modifications can be installed to target proteins precisely,which is a major advantage over trad卜tional bio-synthesis approaches.This review summarizes the techniques developed for protein assembly,including native chemical ligation,5e-mediated ligation,and a range of other ligation methods. .

The disbalance of LRP1 and SIRPα by psychological stress dampens the clearance of tumor cells by macrophages

The relationship between chronic psychological stress and tumorigenesis has been well defined in epidemiological studies;however, the underlying mechanism remains underexplored. In this study, we discovered that impaired macrophage phagocytosis contributed to the psychological stressevoked tumor susceptibility, and the stress hormone glucocorticoid(GC) was identified as a principal detrimental factor. Mechanistically, GC disturbed the balance of the "eat me" signal receptor(low-density lipoprotein receptor-related protein-1, LRP1) and the "don’t eat me" signal receptor(signal regulatory protein alpha, SIRPa). Further analysis revealed that GC led to a direct, glucocorticoid receptor(GR)-dependent trans-repression of LRP1 expression, and the repressed LRP1, in turn, resulted in the elevatedgene level of SIRPa by down-regulating mi RNA-4695-3 p. These data collectively demonstrate that stress induces the imbalance of the LRP1/SIRPa axis and entails the disturbance of tumor cell clearance by macrophages. Our findings provide the mechanistic insight into psychological stress-evoked tumor susceptibility and indicate that the balance of LRP1/SIRPa axis may serve as a potential therapeutic strategy for tumor treatment.

Methyltransferase Dot1l preferentially promotes innate IL-6 and IFN-β production by mediating H3K79me2/3 methylation in macrophages

Epigenetic modification,including histone modification,precisely controls target gene expression.The posttranscriptional regulation of the innate signaling-triggered production of inflammatory cytokines and type I interferons has been fully elucidated,whereas the roles of histone modification alteration and epigenetic modifiers in regulating inflammatory responses need to be further explored.Di/tri-methylation modifications of histone 3 lysine 79(H3K79me2/3)have been shown to be associated with gene transcriptional activation.Disruptor of telomeric silencing-1-like(Dot1l)is the only known exclusive H3K79 methyltransferase and regulates the proliferation and differentiation of tumor cells.However,the roles of Dot1l and Dot1l-mediated H3K79 methylation in innate immunity and inflammatory responses remain unclear.Here,we found that H3K79me2/3 modification levels at the Il6 and Ifnb1 promoters,as well as H3K79me2 modification at the Tnfαpromoter,were increased in macrophages activated by Toll-like receptor(TLR)ligands or virus infection.The innate signals upregulated Dot1l expression in macrophages and THP1 cells.Dot1l silencing or a Dot1l inhibitor preferentially suppressed the production of IL-6 and interferon(IFN)-βbut not of TNFαin macrophages and THP1 cells triggered by TLR ligands or virus infection.Dot1l was recruited to the proximal promoter of the Il6 and Ifnb1 but not Tnfαgene and then mediated H3K79me2/3 modification at the Il6 and Ifnb1 promoters,consequently facilitating the transcription and expression of Il6 and Ifnb1.Thus,Dot1l-mediated selective H3K79me2/3 modifications at the Il6 and Ifnb1 promoters are required for the full activation of innate immune responses.This finding adds new insights into the epigenetic regulation of inflammatory responses and pathogenesis of autoimmune diseases.

KDM2B promotes IL-6 production and inflammatory responses through Brg1-mediated chromatin remodeling

IL-6 plays important and pleiotropic roles in infection and inflammatory diseases,and its production needs to be tightly regulated.However,the epigenetic mechanism underlying Il6 gene transcription remains to be fully elucidated.Here,we report that lysine-specific demethylase 2b(KDM2B),which demethylates H3K4me3 and H3K36me2,is required in macrophages and dendritic cells for the induction of IL-6 but not TNF-α,IL-1,and IFN-β.Compared to wild-type mice,KDM2B-deficient mice were more resistant to endotoxin shock and colitis,with a less severe inflammatory pathogenesis phenotype and decreased IL-6 production in sera.KDM2B selectively bound the Il6 promoter but did not alter histone demethylation;instead,KDM2B interacted with Brahma-related gene 1(Brg1),the core ATPase subunit of SWI/SNF chromatin remodeling complexes,to facilitate chromatin accessibility of the Il6 promoter.Furthermore,KDM2B directly recruited RNA Polymerase II to further initiate and promote Il6 transcription.Thus,our finding identifies a novel nonclassical function of KDM2B in gene-specific transcription initiation and enhancement of Il6 independent of its demethylase activity and adds new insight into the specific epigenetic modification mechanism of inflammatory immune responses.

Preparation of Peptide Selenoesters from Their Corresponding Acyl Hydrazides

Main observation and conclusion Selenoesters are useful substitutes for traditional thioesters in protein ligation chemistry due to their high reactivity in the trans-thio/selenoesterification reaction.However,existing synthetic routes to access peptide selenoester require a selenoesterification reaction between a selenide and a protected peptide with a free carboxylate at the C-terminus.

Influence of nozzle enabling strategy on spray deposition of crop protection unmanned aerial system

Proper nozzles arrangement is significant to improve spray deposition of crop protection unmanned aerial system(UAS).Besides fuselage structure,the control strategy is another nozzle location changing method when there are multiple sets of nozzles.A four-rotor crop protection UAS equipped with four centrifugal nozzles was used to conduct a field experiment in the rupturing stage of rice.Two sets of nozzles in the front and rear of the fuselage were enabled independently to investigate spray deposition,including spray coverage and droplet density on the sampling cards.Various nozzle rotating speeds and flight speeds were employed in the experiment to study the influence of nozzle location on the deposition.With different nozzle rotating speeds,the droplet spectrum could be controlled.The results show that the average coverage and average cumulative droplet density are negatively correlated with flight speed.Average droplet density is also negatively correlated with the droplet size.Spray deposition of front nozzles is significantly reduced compared with that of the rear nozzles under the same spray parameters,especially when the droplet size is too large or the flight speed is too fast.The reduction is mainly concentrated in the center area of the spray swath.As a result,the average cumulative droplet density of the front nozzles decreases by 25.96%in total.The average droplet density decreases by 18.54%when the droplet size is smaller than 100μm,decreases by 25.02%when between 100μm and 200μm,and decreases by more than half when larger than 200μm.This research can provide guidance for the installation of UAS nozzles and spray control strategy design.

Probiotics and Their Metabolites Ameliorate Inflammatory Bowel Disease:A Critical Review

Crohn disease and ulcerative colitis are the two main manifestations of inflammatory bowel disease(IBD),and both are highly morbid.However,the precise etiology of IBD is still unknown and effective therapeutics are yet to be discovered.It is becoming increasingly clear that a combination of factors,including genetic background,host immune response,and microbial reduced diversity status are related to IBD.The cardinal symptom of IBD patients is the imbalance of the intestinal microflora.According to previous studies,both probiotics and symbiotic microbiota can play a protective role through intestinal micro-ecosystem regulation,epithelial barrier integrity enhancement,and inflammation reduction.Therefore,probiotics can provide an alternative or auxiliary method to traditional IBD treatment.Here,we reviewed the possible pathogenesis of IBD,summarized the possible mechanisms of probiotics modulation of IBD,and emphasized the prevention and treatment targets of probiotics-mediated IBD,with the aim to provide theoretical support for the treatment of IBD patients by probiotics in clinical trials.