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Chinese Journal of Structural Chemistry 2006年第2期25卷 153-158页

作者： zeng xiang-chao gu jian xu shi-hai liu po-run Department of Chemistry Jinan University Guangzhou 510632 China

4,5-Dibromo-1-methyl-2-trichloroacetylpyrrole Ⅰ, prepared by the reaction of 1-methyl-2-trichloroacetylpyrrole with Br2 in 98.6 % yield, was condensed with methyl L-2-amino-3- phenylpropanoate to afford methyl 2-（4,5-dibromo-1-methylpyrrole-2-carboxmido）-3-phenylpropanoate Ⅱ in 90.8% yield. Crystal data for Ⅰ： monoclinic system, space group P21/c with a = 8.595（3）, b = 10.900（4）, c = 12.321（5） ,A°,β = 92.292（7）°, V = 1153.4（8）A°^3, Dc = 2.213 g/cm^3, F（000） = 728, CTH4Br2Cl3NO, Mr = 384.28, λ = 0.71073 A°, μ（MoKa） = 7.688 mm^-1, Z = 4, R = 0.0338 and wR2 = 0.0840 for 1963 observed reflections with I 〉 2a（I）. Crystal data for Ⅱ： monoclinic system, space group P21 with a = 4.886（2）, b = 15.921（8）, c = 11.635（6） A°,β = 101.803（9）°, V = 885.9（7） A°^3, Dc = 1.665 g/cm^3, F（000） = 440, C16H16Br2N2O3, Mr = 444.13, λ = 0.71073 A°, μ（MoKa） = 4.590 mm^-1, Z = 2, R = 0.0335 and wR2 = 0.0837 for 3191 observed reflections with I 〉 2σ（I）. The crystal structure reveals that compound Ⅱ forms the one-dimensional chain structure via the intermolecular hydrogen bonds of N（2）-H…O（1）.

关键词： methyl 2-(4,5-dibromo-1-methylpyrrole-2-carbonylamino)-3-phenylpropanoate,synthesis crystal structure 4,5-dibromo-1-methyl-2-trichloroacetylpyrrole

Synthesis and Crystal Structure of 3-(Pyrrole-2′-carboxamido)propanoic Acid·(1/2)H_(2)O

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Chinese Journal of Structural Chemistry 2005年第7期24卷 779-782,737页

作者： zeng xiang-chao xu shi-hai gu jian liu po-run Department of Chemistry Jinan UniversityGuangzhou 510632China

3-(Pyrrole-2?-carboxamido)propanoic acid I has been synthesized from the reaction of β-alanine methyl ester with 2-trichloroacetylpyrrole followed by saponifying and acidating in 85.4% yield, and the crystal structure of 3-(pyrrole-2?-carboxamido)propanoic acid· (1/2)H2O (C8H11N2O3.5, Mr = 191.19) was obtained and determined by X-ray diffraction method. The crystal is of monoclinic, space group C2/c with a = 19.010(4), b = 8.3515(17), c = 13.788(3) ?, β = 125.88(3)o, V = 1773.6(6) ?3, Z = 8, Dc = 1.432 g/cm3, λ = 0.71073 ?, μ(MoKα) = 0.114 mm?1 and F(000) = 768. The structure was refined to R = 0.0354 and wR = 0.0942 for 1642 observed reflections with I > 2σ(I). It is revealed that the title compound has one pyrrole ring and one propionic acid subchain linked by an amido bond at C(4), and there are 8 molecules of com- pound I and 4 crystal water molecules in each unit cell. The supramolecular layers are stabilized by the hydrogen bonds of N(2) H…O(2), N(1) H…O(4), O(4) H(1W)…O(2) and O(3) H…O(1).

关键词： 3-(pyrrole-2′-carboxamido)propanoic acid 2-trichloroacetylpyrrole crystal structure

Adversarial data splitting for domain generalization

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Science China(Information Sciences) 2024年第5期67卷 28-42页

作者： xiang gu jian SUN Zongben xu School of Mathematics and Statistics Xi'an Jiaotong University

Domain generalization aims to learn a model that is generalizable to an unseen target domain,which is a fundamental and challenging task in machine learning for out-of-distribution generalization. This paper proposes a novel domain generalization approach that enforces the learned model to be able to generalize well over the train/val subset splitting of the training dataset. This idea is modeled herein as an adversarial data splitting framework, formulated as a min-max optimization problem inspired by the metalearning approach. The min-max optimization problem is solved by iteratively splitting the training dataset into the training and val subsets to maximize the domain shift measured by the objective function and updating the model parameters to enable the model to generalize well from the training subset to the val subset by minimizing the objective function. This adversarial training approach does not assume the known domain labels of the training data; instead, it automatically investigates the “hard” splitting of the train/val subsets to learn the generalizable model. Extensive experimental results using three benchmark datasets demonstrate the superiority of this approach. In addition, we derive a generalization error bound for the theoretical understanding of our proposed approach.

关键词： domain generalization adversarial learning data splitting meta-learning out of distribution

Effect of pH values on the extracellular polysaccharide secreted by Acidithiobacillus ferrooxidans during chalcopyrite bioleaching

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International Journal of Minerals,Metallurgy and Materials 2014年第4期21卷 311-316页

作者： run-lan Yu Jing liu jian-xi Tan Wei-min zeng Li-juan shi guo-hua gu Wen-qing Qin guan-zhou Qiu School of Minerals Processing and Bioengineering Central South University Key Laboratory of Biometallurgy Ministry of Education Hunan Entry-Exit Inspection and Quarantine Bureau

The pH value plays an important role in the bioleaching of sulphide minerals. The effect of pH values on the extracellular poly-saccharide secreted by Acidithiobacillus ferrooxidans was investigated in different phases of bacterial growth during chalcopyrite bioleach-ing. It is found that extracellular polysaccharide secretion from the cells attached to chalcopyrite is more efficiently than that of the free cells in the bioleaching solution. Three factors, pH values, the concentration of soluble metal ions, and the bacterial growth and metabolism, affect extracellular polysaccharide secretion in the free cells, and are related to the bacterial growth phase. Extracellular polysaccharide secretion from the attached cells is mainly dependent on the pH value of the bacterial culture.

关键词： chalcopyrite bioleaching polysaccharides acidity Acidithiobacillusferrooxidans

Endoscopic ultrasound elastography for differentiating between pancreatic adenocarcinoma and inflammatory masses:A meta-analysis

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World Journal of Gastroenterology 2013年第37期19卷 6284-6291页

作者： xiang Li Wei xu jian shi Yong Lin Xin zeng Department of Gastroenterology Shanghai Changzheng HospitalSecond Military Medical University Spine Tumor Center Changzheng HospitalSecond Military Medical University

AIM:To evaluate the accuracy of endoscopic ultrasound(EUS)elastography for differentiating between pancreatic ductal adenocarcinoma(PDAC)and pancreatic inflammatory masses(PIM).METHODS:Electronic databases(updated to December 2012)and manual bibliographical searches were carried out.A meta-analysis of all diagnostic clinical trials evaluating the accuracy of EUS elastography in differentiating PDAC from PIM was *** was assessed among the *** metaanalysis was performed to evaluate the accuracy of EUS elastography in differentiating PDAC from PIM in homogeneous ***:Ten studies involving 781 patients were included in the *** heterogeneity in sensitivity was observed among the studies(Cochran Q test=24.16,df=9,P=0.0041,I2=62.8%),while heterogeneity in specificity was not observed(Cochran Q test=5.93,df=9,P=0.7473,I2=0.0%).The area under the curve under the Sports Rights Owners Coalition was *** of heterogeneity suggested that the different diagnostic standards used in the included studies were the source of *** studies using the color pattern as the diagnostic standard,the pooled sensitivity,specificity,positive likelihood ratio(LR),negative LR and diagnostic OR were0.99(0.97-1.00),0.76(0.67-0.83),3.36(2.39-4.72),0.03(0.01-0.07)and 129.96(47.02-359.16),*** studies using the hue histogram as the diagnostic standard,the pooled sensitivity,specificity,positive LR,negative LR and diagnostic OR were 0.92(0.89-0.95),0.68(0.57-0.78),2.84(2.05-3.93),0.12(0.08-0.19)and 24.69(12.81-47.59),***:EUS elastography is a valuable method for the differential diagnosis between PDAC and *** a preferable diagnostic standard should be explored and improvements in specificity are required.

关键词： Endoscopic ultrasound Elastography Pancreatic adenocarcinoma Meta-analysis

AIEgens-lightened Functional polymers: Synthesis, Properties and Applications

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Chinese Journal of polymer Science 2019年第4期37卷 302-326,I0005页

作者： shi-Yuan Zhou hai-Bo Wan Feng Zhou Pei-Yang gu Qing-Feng xu jian-Mei Lu College of Chemistry Chemical Engineering and Materials ScienceCollaborative Innovation Center of Suzhou Nano Science and TechnologySoochow University

Recently, polymers with aggregation-induced emission(AIE) effects have attracted significant attention due to their broad applications in luminescence sensors, stimuli responsive materials, electroluminescence devices, etc. In this review, we summarize recent advances concerning AIE polymers. Four types of AIE polymers including end-functionalized polymers, side-chain polymers, main-chain polymers, and other polymers according to the location of AIEgens, are described. Their synthetic preparation, optical property, AIE effects, and applications are also illustrated in this review.

关键词： Aggregation-induced emission Functional polymers Synthetic method Application

Multiple cytokine profiling in serum for early detection of gastric cancer

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World Journal of Gastroenterology 2018年第21期24卷 2269-2278页

作者： jian Li Liang xu zeng-Ci run Wen Feng Wen liu Peng-Jun Zhang Zhi Li Department of general surgery Affiliated Tumor Hospital of Zhengzhou University Department of Oncology General Hospital of Liaohe Oil Field Department of Pathology Affiliated Tumor Hospital of Zhengzhou University Department of Central Laboratory Affiliated Tumor Hospital of Zhengzhou University Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing) Interventional Therapy DepartmentPeking University Cancer Hospital & Institute

AIM To investigate the value of multiparameter joint analysis in the early diagnosis of gastric cancer(GC) in clinical *** Concentrations of CEA, CA724 and three kinds of cytokines(TNF-α, IL-6 and IL-8) in 176 GC patients, 117 atypical hyperplasia patients, and 204 healthy control individuals were used for building the diagnostic model, then 58 GC patients, 41 atypical hyperplasia patients, and 66 healthy control individuals were enrolled independently. The joints of the indicators were analyzed by binary logistic regression analysis *** For discriminating the healthy control group and the GC group, IL-6 had the best diagnostic value, and the area under curve(AUC) of joint analysis was 0.95(0.93-0.97). For the early stage and advanced stage GC, the AUC were 0.95(0.92-0.98) and 0.95(0.92-0.97). For discriminating the atypical hyperplasia group and GC group, CA724 had the best diagnostic value, and the AUC of joint analysis was 0.97(0.95-0.99). For the early stage and advanced stage GC groups, the AUC were 0.98(0.96-0.99) and 0.96(0.94-0.98). After evaluation, for discriminating the GC, early stage GC and advanced cancer group from the healthy control group, the diagnostic sensitivity was 89.66%, 84.21% and 92.31%, respectively, and the specificity was 92.42%, 90.91% and 90.91%. For discriminating the GC, early stage GC and advanced cancer groups from the atypical hyperplasia group, the diagnostic sensitivity was 87.93%, 78.95% and 92.31%, respectively, and the specificity was 87.80%, 85.37% and 90.24%.CONCLUSION We have built a diagnostic model including CEA, CA724, IL-6, IL-8, and TNF-α. It may provide potential assistance as a screening method for the early detection of GC.

关键词： Gastric cancer Atypical hyperplasia Serum Cytokine Early detection

Development of a real-time RT-PCR method for the detection of newly emerged highly pathogenic H7N9 influenza viruses

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Journal of Integrative Agriculture 2017年第9期16卷 2055-2061页

作者： WANG Xiu-rong gu Lin-lin shi jian-zhong xu hai-feng ZHANG Ying zeng Xian-ying DENG guo-hua LI Cheng-jun CHEN Hua-lan State Key Laboratory of Veterinary Biotechnology Harbin Veterinary Research InstituteChinese Academy of Agricultural SciencesHarbin 150069P.R.China

In 2013, a human influenza outbreak caused by a novel H7N9 virus occurred in China. Recently, the H7N9 virus acquired multiple basic amino acids at its hemagglutinin（HA） cleavage site, leading to the emergence of a highly pathogenic virus. The development of an effective diagnostic method is imperative for the prevention and control of highly pathogenic H7N9 influenza. Here, we designed and synthesized three pairs of primers based on the nucleotide sequence at the HA cleavage site of the newly emerged highly pathogenic H7N9 influenza virus. One of the primer pairs and the corresponding probe displayed a high level of amplification efficiency on which a real-time RT-PCR method was established. Amplification using this method resulted in a fluorescent signal for only the highly pathogenic H7N9 virus, and not for any of the H1–H15 subtype reference strains, thus demonstrating high specificity. The method detected as low as 39.1 copies of HA-positive plasmid and exhibited similar sensitivity to the virus isolation method using embryonated chicken eggs. Importantly, the real-time RT-PCR method exhibited 100% consistency with the virus isolation method in the diagnosis of field samples. Collectively, our data demonstrate that this real-time RT-PCR assay is a rapid, sensitive and specific method, and the application will greatly aid the surveillance, prevention, and control of highly pathogenic H7N9 influenza viruses.

关键词： H7N9 highly pathogenic influenza virus real-time RT-PCR

Improving the stability of LiNi_(0.80)Co_(0.15)Al_(0.05)O_2 by Alpo_4 nanocoating for lithium-ion batteries

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Science China Chemistry 2017年第9期60卷 1230-1235页

作者： Ran Qi Ji-Lei shi xu-Dong Zhang Xian-xiang zeng Ya-Xia Yin jian xu Li Chen Wei-gui Fu Yu-guo guo Li-Jun Wan State Key Laboratory of Separation Membranes and Membrane Processes School of Materials Science and EngineeringTt'anjin Polytechnic UniversityTianjin 300071China CAS Research/Education Center for Excellence in Molecular Sciences Institute of ChemistryChinese Academy of SciencesBeo'ing 100190China School of Chemistry and Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

Nickel-rich layered materials,such as LiNi_(0.8)0Co_(0.15)Al_(0.05)O_2(NCA),have been considered as one alternative cathode materials for lithium-ion batteries(LIBs) due to their high capacity and low ***,their poor cycle life and low thermal stability,caused by the electrode/electrolyte side reaction,prohibit their prosperity in practical ***,Alpo4 has been homogeneously coated on the surface of NCA via wet chemical method towards the target of protecting NCA from the attack of *** with the bare NCA,NCA@Alpo_4 electrode delivers high capacity without sacrificing the discharge capacity and excellent cycling *** 150 cycles at 0.5 C between 3.0-4.3 V,the capacity retention of the coated material is 86.9%,much higher than that of bare NCA(66.8%).Furthermore,the thermal stability of cathode is much improved due to the protection of the uniform coating layer on the surface of *** results suggest that Alpo4 coated NCA materials could act as one promising candidate for next-generation LIBs with high energy density in the near future.

关键词： Li-ion batteries cathode materials surface modification Alpo4 coating

Analysis of transcriptome sequencing of sciatic nerves in Sprague-Dawley rats of different ages

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Neural Regeneration Research 2018年第12期13卷 2182-2190页

作者： jiang-Hui liu Qing Tang xiang-Xia liu jian Qi Rui-Xi zeng Zhao-Wei Zhu Bo He Yang-Bin xu Department of Emergency First Affiliated Hospital of Sun Yat-sen University Department of Plastic Surgery First Affiliated Hospital of Sun Yat-sen University Department of Orthopedics and Microsurgery First Affiliated Hospital of Sun Yat-sen University Department of Orthopedics Third Affiliated Hospital of Sun Yat-sen University

An aging-induced decrease in Schwann cell viability can affect regeneration following peripheral nerve injury in mammals. It is therefore necessary to investigate possible age-related changes in gene expression that may affect the biological function of peripheral nerves. Ten 1-week-old and ten 12-month-old healthy male Sprague-Dawley rats were divided into young（1 week old） and adult（12 months old） groups according to their ages. mRNA expression in the sciatic nerve was compared between young and adult rats using next-generation sequencing（NGS） and bioinformatics（n = 4/group）. The 18 groups of differentially expressed mRNA（DEmRNAs） were also tested by quantitative reverse transcription polymerase chain reaction（n = 6/group）. Results revealed that（1） compared with young rats, adult rats had 3608 groups of DEmRNAs. Of these, 2684 were groups of upregulated genes, and 924 were groups of downregulated genes. Their functions mainly involved cell viability, proliferation, differentiation, regeneration, and myelination.（2） The gene with the most obvious increase of all DEmRNAs in adult rats was Thrsp（log2 FC = 9.01, P 〈 0.05）, and the gene with the most obvious reduction was Col2 a1（log2 FC = -8.89, P 〈 0.05）.（3） Gene Ontology analysis showed that DEmRNAs were mainly concentrated in oligosaccharide binding, nucleotide-binding oligomerization domain containing one signaling pathway, and peptide-transporting ATPase activity.（4） Analysis using the Kyoto Encyclopedia of Genes and Genomes showed that, with increased age, DEmRNAs were mainly enriched in steroid biosynthesis, Staphylococcus aureus infection, and graft-versus-host disease.（5） Spearman＇s correlation coefficient method for evaluating NGS accuracy showed that the NGS results and quantitative reverse transcription polymerase chain reaction results were positively correlated（rs = 0.74, P 〈 0.05）. These findings confirm a difference in sciatic nerve gene expression between adult and young rats, suggesting that, in peri

关键词： peripheral nerve injury aging Sprague-Dawley rat transcriptome sequencing mRNA rat age Schwann cells neural regeneration