LS-SVM and Monte Carlo methods based reliability analysis for settlement of soft clayey foundation

A method which adopts the combination of least squares support vector machine（LS-SVM） and Monte Carlo（MC） simulation is used to calculate the foundation settlement reliability.When using LS-SVM,choosing the training dataset and the values for LS-SVM parameters is the key.In a representative sense,the orthogonal experimental design with four factors and five levels is used to choose the inputs of the training dataset,and the outputs are calculated by using fast Lagrangian analysis continua（FLAC）.The decimal ant colony algorithm（DACA） is also used to determine the parameters.Calculation results show that the values of the two parameters,and δ2 have great effect on the performance of LS-SVM.After the training of LS-SVM,the inputs are sampled according to the probabilistic distribution,and the outputs are predicted with the trained LS-SVM,thus the reliability analysis can be performed by the MC method.A program compiled by Matlab is employed to calculate its reliability.Results show that the method of combining LS-SVM and MC simulation is applicable to the reliability analysis of soft foundation settlement.

Late-stage modification of bioactive compounds:Improving druggability through efficient molecular editing

Synthetic chemistry plays an indispensable role in drug discovery,contributing to hit compounds identification,lead compounds optimization,candidate drugs preparation,and so on.As Nobel Prize laureate James Black emphasized,“the most fruitful basis for the discovery of a new drug is to start with an old drug”1.Late-stage modification or functionalization of drugs,natural products and bioactive compounds have garnered significant interest due to its ability to introduce diverse elements into bioactive compounds promptly.Such modifications alter the chemical space and physiochemical properties of these compounds,ultimately influencing their potency and druggability.To enrich a toolbox of chemical modification methods for drug discovery,this review focuses on the incorporation of halogen,oxygen,and nitrogen—the ubiquitous elements in pharmacophore components of the marketed drugs—through late-stage modification in recent two decades,and discusses the state and challenges faced in these fields.We also emphasize that increasing cooperation between chemists and pharmacists may be conducive to the rapid discovery of new activities of the functionalized molecules.Ultimately,we hope this review would serve as a valuable resource,facilitating the application of late-stage modification in the construction of novel molecules and inspiring innovative concepts for designing and building new drugs.

Catalytic conversion of mixed polyolefins under mild atmospheric pressure

The chemical recycling of polyolefin presents a considerable challenge,especially as upcycling methods struggle with the reality that plastic wastes typically consist of mixtures of polyethylene(PE),polystyrene(PS),and polypropylene(PP).We report a catalytic aerobic oxidative approach for polyolefins upcycling with the corresponding carboxylic acids as the product.This method encompasses three key innovations.First,it operates under atmospheric pressure and mild conditions,using O_(2) or air as the oxidant.Second,it is compatible with high-density polyethylene,low-density polyethylene,PS,PP,and their blends.Third,it uses an economical and recoverable metal catalyst.It has been demonstrated that this approach can efficiently degrade mixed wastes of plastic bags,bottles,masks,and foam boxes.

隐源性部分性中枢性尿崩症1例

男,54岁。因“口干、多饮2月余”于2021年1月9日入住成都市中西医结合医院。入院2个月前患者无明显诱因出现口干、多饮,每天饮水量约4 000 mL,每天尿量约6 500~7 000 mL,每天夜尿每30~60分钟1次。门诊测尿比重1.01,尿糖阴性。糖耐量试验:空腹葡萄糖6.36 mmol/L,2 h葡萄糖5.51 mmol/L。发病以来精神可,进食好,大便正常。自诉“血糖升高”2年,未正规治疗。传染病史:乙肝“小三阳”,长期予“舒肝颗粒”“肌苷片”治疗。烟酒史:吸烟20年,平均14支/d,已戒烟12年;偶尔饮酒20年,平均50 g/d。婚育史、家族史无特殊。

松墨天牛成虫室内外种群肠道细菌的多样性及功能分析

【目的】为明确松墨天牛Monochamus alternatus成虫中、后肠细菌群落结构,探索肠道细菌的潜在功能。【方法】分别提取室外和室内饲养的松墨天牛成虫各15头(室内和室外各15个中肠、15个后肠)的肠道DNA,利用二代测序技术对松墨天牛成虫肠道细菌的16S rDNA V3–V4区序列进行测序,统计操作分类单元(OTUs)数量,分析物种组成、Alpha多样性和Beta多样性;采用PICRUSt软件预测肠道细菌的功能。【结果】共获得544180条高质量序列,在97%相似度下将其聚类为615个OTUs,总共注释到22个门、48个纲、112个目、172个科、285个属和408个种。室内种群的OTUs数量多于室外种群,室内外种群的OTUs种类存在差异性。同一种群的中、后肠之间差异不明显。变形菌门Proteobacteria为室内外松墨天牛肠道细菌的最优势门;肠杆菌属Enterobacter为室外种群肠道细菌和室内种群后肠细菌的最优势属,沙雷氏菌属Serratia为室内种群中肠的最优势属。Alpha多样性结果表明松墨天牛成虫室内种群肠道菌群的丰度显著高于室外种群;Beta多样性结果显示室外种群肠道菌群均一性和稳定性比室内种群好。室外和室内种群的中肠与后肠之间在菌群丰度和多样性上均无显著差异。功能预测结果表明,室内外松墨天牛成虫肠道菌群中代谢通路的丰度最高,其中以糖类代谢和氨基酸代谢为主,还有降解外源化学物质、萜类和聚酮类化合物及其他次生代谢物质的能力。不同种群、不同肠段之间的功能丰度均无显著差异。【结论】明确了取食不同食料的松墨天牛成虫中、后肠的细菌群落结构及差异,了解了肠道细菌的潜在作用,为进一步探究松墨天牛肠道共生菌的功能提供了理论基础。

PM2.5 over North China based on MODIS AOD and effect of meteorological elements during 2003-2015

Over the past 40 years,PM2.5 pollution in North China has become increasingly serious and progressively exposes the densely populated areas to pollutants.However,due to limited ground data,it is challenging to estimate accurate PM2.5 exposure levels,further making it unfavorable for the prediction and prevention of PM2.5 pollutions.This paper therefore uses the mixed effect model to estimate daily PM2.5 concentrations of North China between 2003 and 2015 with ground observation data and MODIS AOD satellite data.The tempo-spatial characteristics of PM2.s and the influence of meteorological elements on PM25 is discussed with EOF and canonical correlation analysis respectively.Results show that overall R2 is 0.36 and the root mean squared predicted error was 30.1μg/m^3 for the model prediction.Our time series analysis showed that,the Taihang Mountains acted as a boundary between the high and low pollution areas in North China;while the northern part of Henan Province,the southern part of Hebei Province and the western part of Shandong Province were the most polluted areas.Although,in 2004,2009 and dates after 2013,PM25 concentrations were relatively low.Meteorological/topography conditions,that include high surface humidity of area in the range of 34°-40°N and 119°-124°E,relatively low boundary layer heights,and southerly and easterly winds from the east and north area were common factors attributed to haze in the most polluted area.Overall,the spatial distribution of increasingly concentrated PM2.5 pollution in North China are consistent with the local emission level,unfavorable meteorological conditions and topographic changes.

Application of Modified Progressive Hedging for Stochastic Unit Commitment in Electricity-Gas Coupled Systems

The increasing number of gas-fired units has significantly intensified the coupling between electric and gas power networks.Traditionally,nonlinearity and nonconvexity in gas flow equations,together with renewable-induced stochasticity,resulted in a computationally expensive model for unit commitment in electricity-gas coupled integrated energy systems(IES).To accelerate stochastic day-ahead scheduling,we applied and modified Progressive Hedging(PH),a heuristic approach that can be computed in parallel to yield scenario-independent unit commitment.Through early termination and enumeration techniques,the modified PH algorithm saves considerable com,putational time for certain generation cost settings or when the scale of the IES is large.Moreover,an adapted second-order cone relaxation(SOCR)is utilized to tackle the nonconvex gas flow equation.Case studies were performed on the IEEE 24.bus system/Belgium 20-node gas system and the IEEE 118-bus system/Belgium 20-node gas system.The computational efficiency when employing PH is 188 times that of commercial software,and the algorithm even outperforms Benders Decomposition.At the same time,the gap between the PH algorithm and the benchmark is less than 0.01% in both IES systems,which proves that the solutions produced by PH reach acceptable optimality in this stochastic UC problem.

A zebrafish gene trap line expresses GFP recapturing expression pattern of foxj1b

Foxj1 has been found to play an important role in cilia formation and function in vertebrates. The zebrafish or Xenopus genome expresses two Foxjl genes, foxjlalFoxJ1 and foxjlb/FoxJ1.2. In this study, we have generated a zebrafish transgenic line T2BGSZIO by Tol2 transposon-based gene trapping approach. T2BGSZ10 transgenic fish carry an insertion of the transposon genome into the first intron of thefoxj1b locus. This insertion results in GFP expression in the forebrain, otic vesicles, floorplate, pronephric ducts and other domains during embryogenesis, which recaptures the expression pattern offoxj1b. Although normal expression offoxj1b is dramatically reduced, T2BGSZ10 homozygous embryos develop normally and grow to adulthood without detectable defects, which may be due to the incomplete interruption of foxjlb expression. Nevertheless, this transgenic line may serve as a useful model for dynamic observation of GFP-labeled tissues and organs and for isolation of GFP-labeled cells.

Nitromethane-Enabled Fluorination of Styrenes and Arenes

The electrophilic fluorination of unsaturated compounds provides a reliable approach to the generation of organofluorides,which are used widely in agrochemicals,pharmaceuticals,and other materials.Numerous active electrophilic fluorine reagents,such as the fluorine molecule(F_(2))or xenon difluoride(XeF_(2)),have been applied in fluorination.However,these reagents suffer from their hazardous,toxic,corrosive,and poor selective properties,and the relatively weak electrophilicity of Selectfluor or N-fluorobenzenesulfonimide(NFSI)usually limits their broad applications.Herein,we disclose nitromethane(MeNO_(2))as an efficient activator of Selectfluor and NFSI,as well as a stabilizer of carbocations.Therefore,the fluoro-azidation,fluoroamination,fluoroesterification of styrenes,and C–H fluorination of(hetero)arenes were well realized just by the facilitation of MeNO_(2).The mild reaction conditions and practicability made our current method a versatile protocol for accessing organofluorides.