Full-scale modeling of chemical experiments

Computational chemistry methods are playing an increasingly pivotal role in chemical experiments.From quantum chemistry simulations to finite element simulations,researchers can always find an appropriate simulation method to elucidate the specific mechanisms at a certain resolution scale.However,in organic or inorganic synthesis,the synthesis mechanisms span multiple spatial and temporal scales of chemical experiments.Furthermore,the intricate nature of these mechanisms renders it impossible for any single simulation method to provide a comprehensive depiction of the entire process.In this perspective,using zeolite and polymer synthesis simulations as examples,we stress the significance of fullscale modeling techniques for chemical experiments and urge the corresponding sophisticated simulation platform.

The Hybrid Light Source for Projection Display

A scheme of hybrid light source using lasers and LEDs for projection display is presented;the si-mulation results show that projectors with the proposed scheme can achieve high brightness of over 1000 lm, good uniformity of illumination and chromaticity. It also provides an improved me-thod for light source with longer life, wider color garment and higher adaptability to environment which can replace UHP in traditional projectors.

Parameters of Exterior Ballistic Feature Points Extraction in Radar Measurement Data by EMD

The problem of measuring exterior ballistic feature points is always difficult to solve and it is essentiale on exterior ballistic measurement.By analysis of radar reflection characteristics and non-stationary echo signals of exterior ballistic feature points,the echo data of exterior ballistic feature points is measured by using the continuous wave radar.The parameters of feature points are extracted by the empirical mode decomposition method(EMD)of Hilbert-Huang transform(HHT)spectrum analysis technique.The radar echo signal model and EMD extraction model are established to analyze the exterior ballistic mutation point detection and EMD extraction method of aliasing echo signal.Typical feature point parameters of exterior ballistic in rocket flight tests are carried out and the effectiveness of the method is verified.A new method of measuring the parameters of exterior ballistic feature point is therefore presented.

Radiotherapy combined with transcatheter arterial chemoembolization for unresectable hepatocellular carcinoma–a prospective clinical trial

Objective: This study evaluated the therapeutic effect of external beam radiotherapy (RT) combined with trans- catheter arterial chemoembolization (TACE) on the patients with unresectable hepatocellular carcinoma (HCC). Methods: From June 1994 to April 2002, 114 patients with unresectable HCC were nonrandomized prospectively stepped into our study. All patients received TACE as initial therapy, except 54 also received combination therapy with external beam therapy. Sur- vival failure patterns were analyzed and compared between the two groups. Results: Overall survival rates in the patients in the radiotherapy group were 65%, 47%, 38% at 1, 2, 3 years, respectively, improved over the non-radiotherapy group rates of 54%, 36.5%, 18% at 1, 2, 3 years, respectively. There was significant difference between two groups (P < 0.05). The survival rates correlated with tumor size, number of tumors, and portal vein embolus. Conclusion: TACE combined with RT is a more effective treatment than TACE alone in patients with unresectable HCC.

“酉芯一号”在地方鸡遗传多样性和结构分析中的应用效力研究

我国地方鸡品种资源丰富,且在长期的选择进化过程中形成了各异的种质特性。科学评估群体遗传多样性,明确品种间遗传结构,对地方鸡品种资源的保护与创新利用具有重要价值。为了评估23K SNP芯片“酉芯一号”在地方鸡遗传多样性和遗传结构分析中的应用效力,本文利用RADseq鉴定21个地方鸡种基因组遗传变异,并研发23K芯片“酉芯一号”。基于两组SNP数据集计算各品种的遗传统计量,开展相关性、拟合及系统发育分析,以评估芯片的应用效力。结果表明,基于两组SNP数据集计算的观察杂合度(Ho)、多态信息含量(PIC)、近交系数(F_(ROH))和遗传分化系数(F_(st)),在21个地方鸡种中趋势基本一致。琅琊鸡(LA)、瓢鸡(PJ)、文昌鸡(WC)的遗传多样性较为丰富;边鸡(BJ)、狼山鸡(LS)、固始鸡(GS)、东乡绿壳蛋鸡(DX)和北京油鸡(BY)的遗传多样性相对匮乏,两组Ho、PIC、F_(ROH)和平均Fst的相关系数分别为0.794、0.901、0.926和0.984,均达到极显著水平(P<0.01),且拟合度较高(P<0.001),R^(2)分别为0.644、0.827、0.916和0.927。针对两组SNP数据集,采用邻接法(NJ)和极大似然法(ML)构建的进化树较为合理,将21个地方鸡种总体上分为6大类,与品种的形成历史和地理分布相吻合;23K芯片对5个新增品种亦实现有效聚类,没有出现个体偏离。利用不同密度的SNP估算遗传统计量会存在一定差异,需要进行数据和分析方法的标准化,23K芯片在地方鸡遗传多样性和结构分析中具有较好的效力。

基于“三因致毒”假说的中药免疫特异质肝损伤成因机制解析

特异质药物性肝损伤(Idiosyncratic Drug-induced Liver Injury, IDILI)具有不可预测性和发病率低等特点,一直是新药撤市遇到的瓶颈问题。IDILI发生与机体、环境和药物密切相关,而机体免疫是IDILI发生的主要诱因,故免疫IDILI备受关注。囿于中草药组成和临床用药的复杂性,中药相关特异质肝损伤物质基础和机制的阐释成为研究的难点和热点。课题组前期针对何首乌肝损伤特点,提出了“三因致毒”机制假说,为中药免疫特异质肝损伤的评价和机制研究提供新的思路和方法。因此,本文基于“三因致毒”假说科学内涵,以仙灵骨葆为例,通过文献报道、临床回顾性分析及实验室研究,明确免疫应激可能是其特异质肝损伤的重要诱因;借助免疫应激模型,明确了其肝损伤的物质基础,并区分了成分类型;利用代谢组学技术初步探讨了其机制。结果表明,该假说能够解析其免疫特异质肝损伤的成因机制,具有一定的普适性,可为科学评价中药免疫特异质肝损伤风险防控提供研究思路和科学依据。

Experimental and Numerical Evaluation of the Cavitation Performances of Self-Excited Oscillating Jets

Self-excited oscillating jets(SOJ)are used in several practical applications.Their performances are significantly affected by structural parameters and the target distance.In this study,a geometric model of the SOJ nozzle accounting for multiple structural parameters is introduced,then the related cavitation performances and the optimal target distance are investigated using a Large-Eddy Simulation(LES)approach.Results are also provided about an experiment,which was conducted to validate the simulation results.By analyzing the evolution of the vapor volume fraction at the nozzle outlet,a discussion is presented about the effect of the aforementioned structural parameters on the cavitation performances and the target distance.It is shown that the distribution of cavitation clouds at the outlet of the SOJ nozzle displays a non-monotonic trend(first increasing,then decreasing).Under working conditions with an inlet pressure of 4 MPa,a SOJ nozzle outlet/inlet diameter ratio(D_(1)/D_(2))of 1.2,and a chamber diameter ratio(D/L)close to 1.8,the nozzle outlet cavitation performance attains a maximum.The optimal structural parameters correspond to the optimal target distance,which is near 50 mm.The experiments have revealed that the SOJ nozzle with the above parameters displays a good cavitation erosion effect at the target distance of 50 mm,in satisfactory agreement with the numerical simulation results.

整合代谢组学和肠道菌群揭示补骨脂甲素联合淫羊藿次苷Ⅱ导致特异质肝损伤

仙灵骨葆口服制剂是我国治疗骨病的中药大品种,但近年来国家食品药品监督管理总局通报其易引起肝损伤。传统毒理学研究很难评价其肝损伤作用,我们前期发现仙灵骨葆肝损伤具有特异质属性,拆方研究发现补骨脂和淫羊藿是其导致特异质肝损伤的主要药味,且配伍后其特异质肝损伤加重,呈现七情配伍中“相反”的特点。进一步研究发现,TNF-α介导的免疫应激是其重要诱因,免疫促进成分和肝损伤易感成分存在是其另一重要诱因。然而,具体机制尚不清楚。本研究通过建立动物模型,考察了免疫促进淫羊藿次苷Ⅱ联合肝损伤易感成分补骨脂甲素对小鼠肝损伤的影响;借助非靶向代谢组学技术评价了两个成分联合对肝损伤代谢标志物的影响;利用16S r RNA测序技术探讨了肠道菌群的物种组成和相对丰度的变化。结果表明在TNF-α诱导的免疫应激小鼠模型上发现,单独给药补骨脂甲素能够引起明显肝损伤,而淫羊藿次苷Ⅱ组却无明显变化,但是淫羊藿次苷Ⅱ能够协同补骨脂甲素导致特异质肝损伤;同时代谢组学结果揭示补骨脂甲素联合淫羊藿次苷Ⅱ能够引起小鼠肝脏中甲基氨基甲酰PAF、吲哚-3-醋酸甲酯等代谢物的水平升高,而甘氨酸-酪氨酸(Gly-Tyr)、L-亮氨酰-L-甘氨酸(Leu-Gly)和L-色氨酸-L-丝氨酸(Trp-Ser)等代谢物的水平则下降。这些与肝损伤相关的差异表达代谢物主要富集在鞘脂代谢、鞘脂信号通路和坏死等代谢途径。值得注意的是,补骨脂甲素联合淫羊藿次苷Ⅱ可以诱导肝损伤小鼠肠道中的乳酸杆菌和脱硫弧菌科丰度显著增加。相关性分析结果表明,类杆菌科和脱硫弧菌科与甲基氨基甲酰基PAF和吲哚-3-醋酸甲酯呈正相关,而与Gly-Tyr、Leu-Gly和Trp-Ser呈负相关。本研究初步阐明了补骨脂配伍淫羊藿引起特异质型药物性肝损伤的物质基础和机制,为中成药临床合理使用提供了科学依据。

Simulated Sensitivity of Ozone Generation to Precursors in Beijing during a High O_(3) Episode

This study uses the WRF-Chem model combined with the empirical kinetic modeling method(EKMA curve)to study the compound pollution event in Beijing that happened in 13−23 May 2017.Sensitivity tests are conducted to analyze ozone sensitivity to its precursors,and to develop emission reduction measures.The results suggest that the model can accurately simulate the compound pollution process of photochemistry and haze.When VOCs and NOx were reduced by the same proportion,the effect of O_(3)reduction at peak time was more obvious,and the effect during daytime was more significant than at night.The degree of change in ozone was peak time>daytime average.When reducing or increasing the ratio of precursors by 25%at the same time,the effect of reducing 25%VOCs on the average ozone concentration reduction was most significant.The degree of change in ozone decreased with increasing altitude,the location of the ozone maximum change shifted westward,and its range narrowed.As the altitude increases,the VOCs-limited zone decreases,VOCs sensitivity decreases,NOx sensitivity increases.The controlled area changed from near-surface VOCs-limited to high-altitude NOx-limited.Upon examining the EKMA curve,we have found that suburban and urban are sensitive to VOCs.The sensitivity tests indicate that when VOCs in suburban are reduced about 60%,the O_(3)-1h concentration could reach the standard,and when VOCs of the urban decreased by about 50%,the O_(3)-1h concentration could reach the standard.Thus,these findings could provide references for the control of compound air pollution in Beijing.

Response of spikelet water status to high temperature and its relationship with heat tolerance in rice

In rice, high-temperature stress(HT) during flowering results in decreased grain yield via a reduction in spikelet fertility;however, the effect of plant water status on spikelet fertility under HT remains unknown. To investigate the relationship between spikelet water status and spikelet fertility under HT, two experiments were performed under temperature-controlled conditions using four genotypes with varying tolerance to HT. Rice plants were exposed to HT for seven consecutive days during the flowering stage under three soil water treatments(soil water potential 0, -20, and -40 kPa), as well as under hydroponic conditions in a separate experiment. HT significantly decreased spikelet fertility, pollen fertility, and anther dehiscence under each of the three water treatments. HT significantly increased the spikelet transpiration rate, and this change was accompanied by a significant decrease in the internal temperature of the spikelets. HT decreased pollen grain diameter in heat-sensitive genotypes. HT had varying effects on the water potential of panicles and anthers but increased anther soluble-sugar concentration. Different aquaporin genes showed different expression profiles under HT, and the expression levels of PIPs for plasma membrane intrinsic proteins and TIPs for tonoplast intrinsic proteins increased in anthers but decreased in glumes.Correlation analyses showed that anther dehiscence and pollen(spikelet) fertility were tightly associated with anther water status, and the expression levels of almost all anther aquaporin genes were significantly correlated with anther dehiscence under HT. In summary, an increased spikelet transpiration rate and decreased internal spikelet temperature were associated with alleviation of the effects of HT in rice genotypes with varying degrees of heat tolerance, and the response of spikelet water status to HT, involving increased total expression of aquaporins and soluble sugar content, thereby improved pollen fertility,anther dehiscence, and spikelet fertility, especially in heat-resistant genotypes. The heat-resistant genotypes N22 and SY63 may adopt different approaches to reduce heat damage.

Single Radar Measurement Method for Antiaircraft Projectile Miss Distance

To measure miss distance for antiaircraft projectile,a radial velocity identification and positioning method with a single radar is proposed. By analyzing the spatial resolution of multi-frequency ranging radar,the discrimination and testing model of this radar for multi-targets（ projectile and target） is established to analyze the systematic error of antiaircraft miss distance. Then through the aerial target flight test and contrast test with optical test equipment,the validity of the measurement method is verified. This newmethod has the potential to be used in the measurement of antiaircraft projectile miss distance.

Impacts of Aerosol−Radiation Interactions on the Wintertime Particulate Pollution under Different Synoptic Patterns in the Guanzhong Basin,China

The effects of aerosol-radiation interactions(ARI)are not only important for regional and global climate,but they can also drive particulate matter(PM)pollution.In this study,the ARI contribution to the near-surface fine PM(PM_(2.5))concentrations in the Guanzhong Basin(GZB)is evaluated under four unfavorable synoptic patterns,including“northlow”,“transition”,“southeast-trough”,and“inland-high”,based on WRF-Chem model simulations of a persistent heavy PM pollution episode in January 2019.Simulations show that ARI consistently decreases both solar radiation reaching down to the surface(SWDOWN)and surface temperature(TSFC),which then reduces wind speed,induces sinking motion,and influences cloud formation in the GZB.However,large differences under the four synoptic patterns still exist.The average reductions of SWDOWN and daytime TSFC in the GZB range from 15.2%and 1.04°C in the case of the“transition”pattern to 26.7%and 1.69°C in the case of the“north-low”pattern,respectively.Furthermore,ARI suppresses the development of the planetary boundary layer(PBL),with the decrease of PBL height(PBLH)varying from 18.7%in the case of the“transition”pattern to 32.0%in the case of the“north-low”pattern.The increase of daytime near-surface PM_(2.5)in the GZB due to ARI is 12.0%,8.1%,9.5%,and 9.7%under the four synoptic patterns,respectively.Ensemble analyses also reveal that when near-surface PM_(2.5)concentrations are low,ARI tends to lower PM_(2.5)concentrations with decreased PBLH,which is caused by enhanced divergence or a transition from divergence to convergence in an area.ARI contributes 15%-25%toward the near-surface PM_(2.5)concentrations during the severe PM pollution period under the four synoptic patterns.

Seismic detection of the X-discontinuity beneath the Ryukyu subduction zone from the SdP conversion phase

The X-discontinuity,which appears at the depth of approximately 300 km,is an important seismic interface with positive velocity contrasts in the upper mantle.Detecting its presence and topography can be useful to understand phase transformations of relevant mantle minerals under the high-temperature and high-pressure circumstance of the Earth's interior.In this study,we detect the X-discontinuity beneath the Ryukyu subduction zone using five intermediate-depth events recorded by the dense Alaska Regional Network(AK).The X-discontinuity is successfully revealed from the robust slant stacking of the secondary down-going and converting Sd P phases.From the depth distribution of conversion points,we find that the X-discontinuity's depth ranges between 269 km and 313 km,with an average depth of 295 km.All the conversion points are located beneath the down-dipping side of the Philippine Sea slab.From energy comparisons in vespagrams for observed and synthetic seismograms,the strong converted energy is more likely from a thin high-velocity layer,and the S-wave velocity jumps across the X-discontinuity are up to 5% to 8% with an average of 6.0%.According to previous petrological and seismological studies,the X-discontinuity we detected can be interpreted as the phase transformation of coesite to stishovite in eclogitic materials within the oceanic crust.

Source rupture characteristics of the September 5,2022 Luding M_(S)6.8 earthquake at the Xianshuihe fault zone in southwest China

On September 5,2022,at Beijing time 12:52 p.m.,an M_(S)6.8 earthquake struck Luding County,GarzêTibetan Autonomous Prefecture,Sichuan Province.The epicenter of the earthquake was at the intersection of the Sichuan-Yunnan,Bayankala,and South China blocks.The tectonic background is extremely complex,and strong earthquakes occur frequently.Based on a predetermined focal location and focal mechanism solution for the earthquake,we reversed the focal depth and rupture process of the earthquake by fitting the teleseismic P and SH waves recorded by the global seismic network.The results show that the focal depth is 16 km,with the main rupture having a length of about 45 km near the epicenter,with a maximum displacement of 1.02 m.Although the rupture mainly propagates from the north–northwest(NNW)to the south–southeast(SSE)along the fault strike,there is a small-scale rupture slip zone at shallow depths in the north–northeast(NNE)direction along the epicenter of the seismogenic fault.This rupture image corresponds to the cluster distribution of aftershocks in the NNW and SSE directions starting from the epicenter,corresponding to the distribution of recorded landslides.The earthquake occurred on the Moxi fault,located in the southeastern section of the Xianshuihe fault.The major tectonic feature in this area is the southeastward movement of the Chuandian block relative to the Bayanhar block.

Coarse-Grained Molecular Dynamics Study based on TorchMD

The coarse grained(CG)model implements the molecular dynamics simulation by simplifying atom properties and interaction between them.Despite losing certain detailed information,the CG model is still the first-thought option to study the large molecule in long time scale with less computing resource.The deep learning model mainly mimics the human studying process to handle the network input as the image to achieve a good classification and regression result.In this work,the TorchMD,a MD framework combining the CG model and deep learning model,is applied to study the protein folding process.In 3D collective variable(CV)space,the modified find density peaks algorithm is applied to cluster the conformations from the TorchMD CG simulation.The center conformation in different states is searched.And the boundary conformations between clusters are assigned.The string algorithm is applied to study the path between two states,which are compared with the end conformations from all atoms simulations.The result shows that the main phenomenon of protein folding with TorchMD CG model is the same as the all-atom simulations,but with a less simulating time scale.The workflow in this work provides another option to study the protein folding and other relative processes with the deep learning CG model.

Expert Recommendation in Community Question Answering via Heterogeneous Content Network Embedding

ExpertRecommendation(ER)aims to identify domain experts with high expertise and willingness to provide answers to questions in Community Question Answering(CQA)web services.How to model questions and users in the heterogeneous content network is critical to this task.Most traditional methods focus on modeling questions and users based on the textual content left in the community while ignoring the structural properties of heterogeneous CQA networks and always suffering from textual data sparsity issues.Recent approaches take advantage of structural proximities between nodes and attempt to fuse the textual content of nodes for modeling.However,they often fail to distinguish the nodes’personalized preferences and only consider the textual content of a part of the nodes in network embedding learning,while ignoring the semantic relevance of nodes.In this paper,we propose a novel framework that jointly considers the structural proximity relations and textual semantic relevance to model users and questions more comprehensively.Specifically,we learn topology-based embeddings through a hierarchical attentive network learning strategy,in which the proximity information and the personalized preference of nodes are encoded and preserved.Meanwhile,we utilize the node’s textual content and the text correlation between adjacent nodes to build the content-based embedding through a meta-context-aware skip-gram model.In addition,the user’s relative answer quality is incorporated to promote the ranking performance.Experimental results show that our proposed framework consistently and significantly outperforms the state-of-the-art baselines on three real-world datasets by taking the deep semantic understanding and structural feature learning together.The performance of the proposed work is analyzed in terms of MRR,P@K,and MAP and is proven to be more advanced than the existing methodologies.

K-means Find Density Peaks in Molecular Conformation Clustering

Performing cluster analysis on molecular conformation is an important way to find the representative conformation in the molecular dynamics trajectories.Usually,it is a critical step for interpreting complex conformational changes or interaction mechanisms.As one of the density-based clustering algorithms,find density peaks(FDP)is an accurate and reasonable candidate for the molecular conformation clustering.However,facing the rapidly increasing simulation length due to the increase in computing power,the low computing efficiency of FDP limits its application potential.Here we propose a marginal extension to FDP named K-means find density peaks(KFDP)to solve the mass source consuming problem.In KFDP,the points are initially clustered by a high efficiency clustering algorithm,such as K-means.Cluster centers are defined as typical points with a weight which represents the cluster size.Then,the weighted typical points are clustered again by FDP,and then are refined as core,boundary,and redefined halo points.In this way,KFDP has comparable accuracy as FDP but its computational complexity is reduced from O(n^(2))to O(n).We apply and test our KFDP method to the trajectory data of multiple small proteins in terms of torsion angle,secondary structure or contact map.The comparing results with K-means and density-based spatial clustering of applications with noise show the validation of the proposed KFDP.

Facile synthesis of colloidal nitrogen-doped titanium carbide sheets with enhanced electrochemical performance

Heteroatom nitrogen doping in two-dimensional transition metal carbides,known as MXenes,has been considered as a promising strategy for modulating their electronic structure and electrochemical reactivity.While hightemperature annealing in the presence of a nitrogen source has been one popular method to introduce nitrogen,annealing exfoliated multilayered MXenes typically brings about incomplete delamination and the treatment of delaminated monolayer MXenes often leads to irreversible restacking.Here,starting from the typical carbide precursor,we developed an aqueous colloid containing monolayered nitrogen-doped titanium carbide sheets with excellent dispersity and stability.This achievement is critically dependent on the retaining of the hydrophilic surface of host layers during annealing treatment.The successful realization of nitrogen doping into individual MXene monolayers resulted in enhanced electrical conductivity and redox reactivity,for which the sample exhibited excellent capacitive electrochemical performance(586 F/g at a scan rate of 5mV/s)and cycling stability(capacitance retention of 96.2%after 104 cycles at 5 A/g).This paper presents a feasible and simple strategy for designing nitrogen-doped MXenes colloid,the realization of which promises its facile uses in liquid phase engineering techniques toward versatile applications.

SI of Interaction energy prediction of organic molecules using Deep Tensor Neural Network

The support informations of DTNN architecture and prediction results of six testing cases in K-fold are listed here.

Herb induced liver injury by Xianling Gubao Tablets: A case assessed for causality using updated RUCAM and integrated evidence chain

Objective:A typical case of Xianling Gubao(XLGB)Tablets-induced liver injury was systematically studied in the clinic and the laboratory.Methods:A patient with herb-induced liver injury(HILI)and a history of taking XLGB Tablets before disease onset was engaged as the study subject,and the case was diagnosed according to the updated Roussel Uclaf Causality Assessment Method(RUCAM)and the integrated evidence chain(iEC)method recommended by the Guidelines for Diagnosis and Treatment of Herb-induced Liver Injury(HILI Guidelines).Results:Clinical history,biochemical indexes and imaging tests were used to exclude the influence of fundamental diseases and confusing liver diseases such as viral,alcoholic and autoimmune liver diseases on the diagnosis.Based on an investigation of the patient’s medication history,she was suspected to have HILI caused by XLGB Tablets,as the patient was only taking an oral preparation of XLGB Tablets,and the influence of other drugs on the diagnosis was excluded.This patient with alanine aminotransferase(ALT)3 upper limit of normal(ULN)and a calculated R of 6 was diagnosed with possible acute drug-induced hepatocellular injury.The relationship was considered“highly probable”(score of 9)using the updated RUCAM of 2016.Moreover,the fingerprint similarity between the preparation taken by the patient and a commercially available preparation was 0.99,suggesting that the patient was consuming XLGB Tablets rather than another drug.LC-MS technology and the Agilent Fake TCM-Drugs database were used to investigate the drug,and no chemical additions were found.Examination of the drug for pesticide residues,heavy metals,aflatoxins and other exogenous substances indicated compliance with the content limits of the Chinese Pharmacopoeia.Conclusion:In summary,the final diagnosis of XLGB-induced liver injury reached the clinical diagnosis of HILI and was acute severe hepatocellular injury type by the updated RUCAM and iEC.Therefore,this study provides scientific evidence regarding the causality evaluation of compound preparations of traditional Chinese medicines-induced liver injury.