检索结果-南通市图书馆

Alisol B acetate induces apoptosis of SGC7901 cells via mitochondrial and phosphatidylinositol 3-kinases/Akt signaling pathways

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2009年第23期15卷 2870-2877页

作者： Yong-hong xu li-Jie Zhao Yan li Department of DigestiveDiseases Shengjing Hospital of China Medical UniversityShenyang 110004 Liaoning Province China

AIM： To examine the effect of alisol B acetate on the growth of human gastric cancer cell line SGC7901 and its possible mechanism of action.METHODS： The cytotoxic effect of alisol B acetate on SGC7901 cells was measured by 3-（4,5-dimethylthiazol- 2-yl）-2,5-diphenyltetrazolium bromide （MI-I-） assay. Phase-contrast and electron microscopy were used to observe the morphological changes. Cell cycle and mitochondrial transmembrane potential （A^Pm） were determined by flow cytometry. Western blotting was used to detect the expression of apoptosis-regulated gene Bcl-2, Bax, Apaf-1, caspase-3, caspase-9, Akt, P-Akt and phosphatidylinositol 3-kinases （PI3K）.RESULTS： Alisol B acetate inhibited the proliferation of SGC7901 cell line in a time- and dose-dependent manner. PI staining showed that alisol B acetate can change the cell cycle distribution of SGC7901, increase the proportion of cells in G0-G1 phase and decrease the proportion of S phase cells and G2-M phase cells. Alisol B acetate at a concentration of 30 pmol/L induced apoptosis after 24, 48 and 72 h incubation, with occurrence rates of apoptotic cells of 4.36%, 14.42% and 21.16%, respectively. Phase-contrast and electron microscopy revealed that the nuclear fragmentation and chromosomal condensed, cells shrank and attachment loss appeared in the SGC7901 treated with alisol B acetate. Apoptosis of SGC7901 cells was associated with cell cycle arrest, caspase-3 and caspase-9 activation, loss of mitochondrial membrane potential and up-regulation of the ratio of Bax/Bcl-2 and inhibition of the PI3K/Akt.CONCLUSION： Alisol B acetate exhibits an antiproliferative effect in SGC7901 cells by inducing apoptosis. Apoptosis of SGC7901 cells involves mitochondria-caspase and PI3K/Akt dependent pathways.

关键词： Alisol B acetate Apoptosis Mitochondria Phosphatidylinositol 3-kinases/Akt SGC7901 cells

Recovery of scandium from bauxite residue——red mud:a review

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2016年第12期35卷 887-900页

作者： Na Zhang hong-xu li Xiao-Ming liu School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing Key Laboratory of Rare and Precious Metals Green Recycling and Extraction University of Science and Technology Beijing

Red mud is a slimy caustic residue generated from alumina production. Taking into account the rela- tively considerable content and availability of scandium, red mud can be viewed as an important and promising scandium resource rather than a solid waste. This paper is primarily to review the investigations of scandium recov- ery from red mud based on the most widely used hydrometallurgical processes including acid leaching, sol- vent extraction and ion exchange adsorption. It is thought that recovery of scandium from red mud should be con- sidered as a direct objective rather than a by-product in the development of overall flowsheet. In order to achieve environmentally-friendly processes with high scandium recovery and low cost, more attention is required to be paid to optimizing the selective leaching of scandium to decrease mineral acid consumption and alleviate pollution, and developing new solvent extraction systems and novel ion exchange adsorption materials with high selectivity and recognition for scandium.

关键词： Red mud Scandium Acid leaching Solvent extraction Ion exchange Selectivity

Molecular Biological and Biochemical Studies Reveal New Pathways Important for Cotton Fiber Development

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2007年第1期49卷 69-74页

作者： Yu xu hong-Bin li Yu-Xian Zhu National Laboratory of Protein Engineering and Plant Genetic Engineering Peking University Beijing 100871 China

As one of the longest single-celled seed trichomes, fibers provide an excellent model for studying fundamental biological processes such as cell differentiation, cell expansion, and cell wall biosynthesis. In this review, we summarize recent progress in cotton functional genomic studies that characterize the dynamic changes in the transcriptomes of fiber cells. Extensive expression profilings of cotton fiber transcriptomes have provided comprehensive information, as quite a number of transcription factors and enzyme-coding genes have been shown to express preferentially during the fiber elongation period. Biosynthesis of the plant hormone ethylene is found significantly upregulated during the fiber growth period as revealed by both microarray analysis and by biochemical and physiological studies. It is suggested that genetic engineering of the ethylene pathway may improve the quality and the productivity of cotton lint. Many metabolic pathways, such as biosynthesis of cellulose and matrix polysaccharides are preferentially expressed in actively growing fiber cells. Five gene families, including proline-rich proteins （PRP）, arabinogalactan proteins （AGP）, expansins, tubulins and lipid transfer proteins （LTP） are activated during early fiber development, indicating that they may also be needed for cell elongation. In conclusion, we identify a few areas of future research for cotton functional genomic studies.

关键词： cotton fiber functional genomics plant hormone transcriptome transcription factors

Electron probe microanalysis for revealing occurrence mode of scandium in Bayer red mud

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2017年第4期36卷 295-303页

作者： Na Zhang hong-xu li Hui-Jing Cheng Xiao-Ming liu School of Metallurgical and Ecological Engineering Universityof Science and Technology Beijing Beijing 100083 China Beijing Key Laboratory of Rare and Precious Metals GreenRecycling and Extraction University of Science and TechnologyBeijing Beijing 100083 China State Key Laboratory of Advanced Metallurgy University ofScience and Technology Beijing Beijing 100083 China

Red mud is a bauxite residue generated during the process of alumina production. In this research, the occur- rence mode of scandium in the Bayer red mud was investi- gated mainly by electron probe microanalysis （EPMA）. The Bayer red mud used in this work is composed of 21.47 wt% hematite, 12.13 wt% goethite, 8.86 wt% gibbsite, 5.02 wt% perovskite, 9.70 wt% quartz, 3.23 wt% anhydrite, 29.92 wt% Na_2Al_2Si_5O_14 and 9.67 wt% Al_3Fe_5O_12. Besides, the scandium content in the Bayer red mud is 84.32 × 10-6, indicating that this Bayer red mud is an important scandium resource deserving exploitation. The EPMA results show that the scandium within the Bayer red mud is mainly occurring in the iron minerals of hematite and goethite with the isomorphism form, but its distribution is not homogeneous in these iron minerals with the Sc_2O_3 content between 330 × 10-6 and 2040 × 10-6. This study provides a theoretical base for the further experimental work on the scandium extraction from this Bayer red mud.

关键词： Scandium Occurrence mode Bayer red mud Electron probe microanalysis

Synthesis,Characterization and Antibacterial Activity of New 5-Aryl Pyrazole Oxime Ester Derivatives

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2008年第4期24卷 454-458页

作者： liU Xin-hua ZHI li-ping SONG Bao-an xu hong-li Key Laboratory of Anhui Educational Department Faculty of Mathematics ＆ Physics Anhui University of Technology Ma ＇anshan 243002 P R. China Key Laboratory of Green Pesticide and Agriculture Bioengineering Ministry of Education Guizhou University Guiyang 550025 P. R. China

Eleven new 1-{5-[4-（benzyloxy）phenyl]-3-methyl-4,5-dihydropyrazol-l-yl} oxime ester dcrivatives were synthesized and characterized by elemental analysis, HRMS, ^1H NMR data. All the compounds were screened for their antibacterial potential in vitro against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results indicate that compounds 8c and 8f possess potent activity with the minimum inhibitory concentrations（MIC） of 1.562--3.125 ug/mL against all the four bacteria. Compounds 8c, 8e and 8f show moderate inhibition against the DNA gyrase（IC50=1.9--2.5 ug/mL）. On the basis of the biological activities, structure-activity relationship was discussed.

关键词： 5-Aryl pyrazole Oxime ester Antibacterial activity

High quality Sb-doped SnO2 electrodes with high oxygen evolution potential prepared by in situ hydrothermal synthesis method

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2007年第8期18卷 997-1000页

作者： Ai Sheng Huang Guo Hua Zhao hong xu li Department of Chemistry Tongji University Shanghai 200092 China

High quality Sb-doped SnO2 electrode, with high oxygen evolution potential of 3.0 V, was successfully synthesized on the Ti substrates by in situ hydrothermal synthesis method.

关键词： Metallic oxide electrode Hydrothermal synthesis Oxygen evolution reaction

Kinetic Study of SiO_2/S Coating Deposition by APCVD

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2007年第4期23卷 535-540页

作者： Jianxin ZHOU hong xu li ZHANG Jinglei liU xuegui QI Bo PENG State Key Laboratory of Chemical Engineering East China University of Science and Technology Shanghai 200237 China

To alleviate catalytic coking on the inner surface of radiant tube for ethylene production in petrochemical plants,SiO2/S coatings were deposited on HP40 alloy specimens using dimethyldisulfide （DMDS） and tetraethoxysilane （TEOS） by atmospheric pressure chemical vapor deposition （APCVD）. A two-dimension mathematical model was made to predict the growth rate of SiO2/S coating and to study the effects of deposition parameters on the deposition rate. The results show that the predicted deposition rate is in good agreement with the experimental one. The deposition rate mainly depends on the concentrations of precursors in the total gas flow, concentrations of intermediates on the deposition surface, total gas flow rate and deposition temperature. The weight of SiO2/S coating linearly increases with the deposition time. When the gas flow rate is below 0.3 m/s, the rate-limiting step of SiO2/S coating deposition is the diffusions of ***, the surface reactions of intermediates will be the rate-limiting step after the gas flow rate is above 0.3 m/s. When the deposition temperature is below 780℃, the rate-limiting step of SiO2/S coating deposition mainly depends on the surface reactions of intermediates. When the deposition temperature is above 780℃,the rate-limiting step depends on the diffusions of intermediates. The deposition rate increases with increasing the concentrations of the intermediates. However, when the partial pressures of the intermediates reach 8 Pa,the deposition rate keeps constant.

关键词： APCVD SiO2/S coating Mathematical model HP40 steel Kinetics

A Granularity-Aware Parallel Aggregation Method for Data Streams

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2006年第1期11卷 133-137页

作者： WANG Yong-li xu hong-bing xu li-zhen QIAN Jiang-bo liU xue-jun Department of Computer Science and Engineering Southeast University Nanjing 210096 Jiangsu China

This paper focuses on the parallel aggregation processing of data streams based on the shared-nothing architecture. A novel granularity-aware parallel aggregating model is proposed. It employs parallel sampling and linear regression to describe the characteristics of the data quantity in the query window in order to determine the partition granularity of tuples, and utilizes equal depth histogram to implement partitio ning. This method can avoid data skew and reduce communi cation cost. The experiment results on both synthetic data and actual data prove that the proposed method is efficient, practical and suitable for time-varying data streams processing.

关键词： data streams parallel processing linear regression aggregation data skew

Reversal of idiopathic hypogonadotropic hypogonadism： a cohort study in Chinese patients

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2015年第3期17卷 497-502页

作者： Jiang-Feng Mao hong-li xu Jin Duan Rong-Rong Chen li li Bin li Min Nie Le Min hong-Bing Zhang xue-Yan Wu Department of Endocrinology Peking Union Medical College Hospital Key Laboratory of Endocrinology Ministry of Health Beijing 100730 China Department of Physiology State Key Laboratory of Medical Molecular Biology Institute of Basic Medical Sciences and School of Basic Medicine Peking Union Medical College and Chinese Academy of Medical Sciences Beijing 100005 China Beijing Genomics Institute at Shenzhen Shenzhen 518083 China Division of Endocrinology Diabetes and Hypertension Brigham and Women's Hospital Harvard Medical School Boston MA 02115 USA

Although idiopathic hypogonadotropic hypogonadism （IHH） has traditionally been viewed as a life-long disease caused by a deficiency of gonadotropin-releasing hormone neurons, a portion of patients may gradually regain normal reproductive axis function during hormonal replacement therapy. The predictive factors for potential IHH reversal are largely unknown. The aim of our study was to investigate the incidence and clinical features of IHH male patients who had reversed reproductive axis function. In this retrospective cohort study, male IHH patients were classified into a reversal group （n = 18） and a nonreversal group （n = 336）. Concentration of gonadotropins and testosterone, as well as testicle sizes and sperm counts, were determined. Of 354 IHH patients, 18 （5.1%） acquired normal reproductive function during treatment. The median age for reversal was 24 years old （range 21-34 years）. Compared with the nonreversal group, the reversible group had higher basal luteinizing hormone （LH）（1,0±0.7 IU 1-1 vs 0.4±0.4 IU 1-1, P 〈 0.05） and stimulated LH （28.3 ± 22.6 IU 1-1 vs 1.9 ±1.1 IU 1-1, P 〈 0.01） levels, as well as larger testicle size （5.1 ±2.6 ml vs 1.5± 0.3 ml, P〈 0.01）, at the initial visit. In summary, larger testicle size and higher stimulated LH concentrations are favorite parameters for reversal. Our finding suggests that reversible patients may retain partially active reproductive axis function at initial diagnosis.

关键词： hypothalamic-pituitary-gonadal axis idiopathic hypogonadotropic hypogonadism reversal