检索结果-南通市图书馆

N-Soliton Solutions of(2+1)-Dimensional Non-isospectral AKNS System

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第11期50卷 1181-1184页

作者： ZHANG Xiao-xian sun Ye-Peng Department of Mathematics Lanzhou City University Lanzhou 730070 China School of Statistics and Mathematics Shandong Economic University Jinan 250014 China

The bilinear form of the （2＋1）-dimensional non-isospectral AKNS system is derived. Its N-soliton solutions are obtained by using the Hirota method. As a reduction, a （2＋1）-dimensional non-isospectral Schrodinger... 详细信息

关键词： non-isospectral AKNS system Hirota method N-soliton solution non-isospectral Schrodinger equation

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

Interactions between Bioactive Diperoxovanadate Complexes and Imidazole: Insights into Their Solution Structures by NMR and ESI-MS

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

Chinese Journal of Structural Chemistry 2004年第6期23卷 511-518页

作者： yu xian-Yong CAI Shu-Hui CHEN Zhong Departments of Physics and Chemistry State Key Laboratory for Physical Chemistry of Solid SurfaceXiamen UniversityXiamen 361005China State Key Laboratory of Structural Chemistry Fuzhou 350002China

The interactions between four high bioactive diperoxovanadate complexes Kn[OV(O2)2L]mH2O (n = 1~3, m = 1~5, L = oxalate (abbr. oxa), picolinate (abbr. pic), bipyridine (abbr. bipy) and 1,10-phenanthroline (abbr. phen); their corresponding complexes abbreviated as bpV(oxa), bpV(pic), bpV(bipy) and bpV(phen), respectively) and imidazole (abbr. imi) in solution were studied by several NMR techniques: multinuclear (1H, 13C and 51V) and variable temperature 51V NMR. Competitive coordination interactions were observed and the order of the interaction strength of the four complexes with imidazole is as follows: bpV(oxa) > bpV(pic) > bpV(bipy) > bpV(phen), which is deeply affected by the identity of the ligands and has the same order as their inhibition effect toward bovine heart phosphotyrosyl protein phosphatase. The species [OV- (O2)2(imi)]- was formed in all cases. Both of the NMR data and equilibrium constants of the interaction systems were reported. The experimental results indicate that the species of bpV(oxa) and [OV(O2)2(imi)]- are six-coordinated, while bpV(pic), bpV(bipy) and bpV(phen) are seven- coordinated in solution. ESI-MS results support the conclusions obtained by NMR.

关键词： diperoxovanadate imidazole interaction NMR ESI-MS

Reevaluating Data Stall Time with the Consideration of Data Access Concurrency

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2015年第2期30卷 227-245页

作者：刘宇航孙贤和 Department of Computer Science Illinois Institute of Technology Chicago IL 60616-3793 U.S.A.

Data access delay has become the prominent performance bottleneck of high-end computing systems. The key to reducing data access delay in system design is to diminish data stall time. Memory locality and concurrency are the two essential factors influencing the performance of modern memory systems. However, existing studies in reducing data stall time rarely focus on utilizing data access concurrency because the impact of memory concurrency on overall memory system performance is not well understood. In this study, a pair of novel data stall time models, the L-C model for the combined effort of locality and concurrency and the P-M model for the effect of pure miss on data stall time, are presented. The models provide a new understanding of data access delay and provide new directions for performance optimization. Based on these new models, a summary table of advanced cache optimizations is presented. It has 38 entries contributed by data concurrency while only has 21 entries contributed by data locality, which shows the value of data concurrency. The L-C and P-M models and their associated results and opportunities introduced in this study are important and necessary for future data-centric architecture and algorithm design of modern computing systems.

关键词： memory wall data stall time memory concurrency concurrent average memory access time (C-AMAT)

Expression of p53 in myocardium following coronary microembolization inrats and its significance

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

Journal of Geriatric Cardiology 2017年第5期14卷 292-300页

作者： yu-Han sun Qiang SU Lang LI xian-Tao WANG yuan-Xi LU Jia-Bao LIANG Department of Cardiology the First Affiliated Hospital of Guangxi Medical University Nanning China

Background Cardiomyocyte apoptosis is a primary cause for coronary microembolization （CME）-induced cardiac dysfunction, p53induces cell growth retardation and apoptosis through stress pathway. The present study investigated the mechanism of p53-induced myocar-dial apoptosis and cardiac dysfunction by activating the mitochondrion apoptotic pathway following CME. Methods Forty SD rats wereequally divided into microembolization （CME）, sham operation （sham）, CME＋siRNA-p53, and CME＋control-p53 groups. The CME ratmodel was established by injecting microembolization spheres via the left ventricle. Cardiac ultrasound, TUNEL, fluorescence quantitativePCR, and Western blot were used to assess the cardiac function indicators, cardiomyocyte apoptosis, and the expressions of mRNA and pro-tein in myocardial tissues, respectively. Results Echocardiography revealed a significantly reduced cardiac function of the CME group thanthe sham group while the CME-induced cardiac dysfunction was improved in the CME＋siRNA-p53 group. The indicators of myocardialapoptosis in the CME group increased significantly than the sham group; those of the CME＋siRNA-p53 group decreased significantly thanthe CME group. Fluorescence quantitative PCR and Western blot demonstrated that p53, Bbc3 （PUMA）, and cleaved caspase-3 expressionswere significantly increased, and BCL-2 expression was declined in myocardial tissues of the CME group compared to the sham group. Acontrasting result was observed in the CME＋siRNA-p53 group as compared to the CME group. Conclusions P53 is involved in theCME-induced cardiac dysfunction, which may up-regulate Bbc3 to activate BCL-2/caspase3 mitochondrial apoptotic pathway and inducemyocardial apoptosis. Inhibiting the p53 expression can effectively suppress this pathway, thereby reducing myocardial apoptosis and car-diac dysftmction.

关键词： Bbc3 BCL-2 Cardiac dysfunction Coronary microembolization Myocardial apoptosis p53

Nicorandil pretreatment inhibits myocardial apoptosis and improves cardiac function after coronary microembolization in rats

在线全文

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2018年第9期15卷 591-597页

作者： Wen-Kai HE Qiang SU Jiao-Bao LIANG xian-Tao WANG yu-Han sun Lang LI Department of Cardiology the First Affiliated Hospital of Guangxi Medical University Nanning China

Background Nicorandil （NIC） is a vasodilatory drug used to treat angina. However, its efficacy of cardioprotection in coronary mi- croembolization （CME） is largely unknown. This study was undertaken to determine whether nicorandil pretreatment could attenuate myo- cardial apoptosis and improve cardiac function after CME in rats. Methods Forty-five rats were randomly divided into a Sham group, a CME group and a CME ＋ NIC （NIC） group （n = 15 per group）. CME was established by injecting plastic microspheres （42 pm in diameter） into the left ventricle of the rats in all of the groups except the Sham group. The NIC group received nicorandil at 3 mg/kg per day for seven days before the operation. Cardiac fimction was assessed by echocardiography, the expression levels of cleaved caspase-9/8/3 were detected by Western blot, microinfarction area was measured by haematoxylin-basic fuchsin picric acid staining, and myocardial apoptosis was de- tected by TUNEL staining. Results Compared to that in the Sham group, cardiac fimction in the CME group was significantly decreased （P 〈 0.05）. However, compared to the CME group, the NIC group showed improved cardiac function （P 〈 0.05）. The expression levels of cleaved caspase-9/8/3 protein and myocardial apoptosis were dramatically increased in the CME group compared to those in the Sham group （P 〈 0.05）, while the NIC pretreatment group had significantly decreased expression levels of cleaved caspase-9/8/3 protein as well as a de- creased apoptotic rate （P 〈 0.05）. Conclusions NIC pretreatment inhibited CME-induced myocardial apoptosis and improved cardiac func- tion through blockade of the mitochondrial and death receptor-mediated apoptotic pathways.

关键词： Apoptosis Coronary microembolization Cardiac function Nicorandil

Antiproliferation and apoptosis induction of paeonol in HepG_2 cells

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第2期13卷 250-256页

作者： Shu-Ping Xu Guo-Ping sun yu-xian Shen Wei Wei Wan-Ren Peng Hua Wang Institute of Clinical Pharmacology of Anhni Medical University Key Laboratory of Antiinflammatory and Immunological Pharmacology in Anhui Province Key Laboratory of Research and Development of Chinese Medicine of Anhui province Hefei 230032 Anhui Province. China Department of Oncology The First Affiliated Hospital of Anhui Medical University Hefei 230022 Anhui Province China Department of Oncology Provincial Hospital of Anhui Hefei 230001 Anhui Province China

AIM： To investigate the antiproliferative effect of paeonol （Pae） used alone or in combination with chemotherapeutic agents [cisplatin （CDDP）, doxorubicin （DOX） and 5-fluorouracil （5-FU）] on human hepatoma cell line HepG2 and the possible mechanisms. METHODS： The cytotoxic effect of drugs on HepG2 cells was measured by 3-（4, 5-dimethylthiazol-2- yl）-2, 5-diphenyltetra-zolium bromide （MTT） assay. Morphologic changes were observed by acridine orange （AO） fuorescence staining. Cell cycle and apoptosis rate were detected by flow cytometry （FCM）. Drug-drug interactions were analyzed by the coefficient of drug RESULTS： Pae （7.81-250 mg/L） had an inhibitory effect on the proliferation of HepG2 cells in a dose-dependent manner, with the IC50 value of （104.77±7.28） mg/L. AO fluorescence staining and FCM assays showed that Pae induced apoptosis and arrested cell cycle at S phase in HepG2 cells. Further, different extent synergisms were observed when Pae （15.63, 31.25, 62.5 rag/L） was combined with CDDP （0.31-2.5 mg/L）, DOX （0.16-1.25 mg/L）, or 5-FU （12.5-100 mg/L） at appropriate concentrations. The IC50 value of the three drugs decreased dramatically when combined with Pae （P 〈 0.01）. Of the three different combinations, the sensitivity of cells to drugs was considerably ***： Pae had a significant growth-inhibitory effect on the human hepatoma cell line HepG2, which may be related to apoptosis induction and cell cycle arrest. It also can enhance the cytotoxicity of chemotherapeutic agents on HepG2 cells, and the S phase arrest induced by Pae may be one of the mechanisms of these interactions.

关键词： Paeonol Hepatocellular carcinoma Apoptosis Cell cycle Cisplatin Doxorubicin 5-fluorouracil Synergistic effect

Development of degradable pre-formed particle gel(DPPG)as temporary plugging agent for petroleum drilling and production

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

Petroleum Science 2021年第2期18卷 479-494页

作者： Dao-Yi Zhu Xing-yu Fang Ren-xian sun Zeng-Hao Xu Yang Liu Ji-Yang Liu College of Petroleum China University of Petroleum-Beijing at KaramayKaramay834000XinjiangChina

Temporary plugging agent(TPA)is widely used in many fields of petroleum reservoir drilling and production,such as temporary plugging while drilling and petroleum well stimulation by diverting in acidizing or fracturing *** commonly used TPA mainly includes hard particles,fibers,gels,and composite ***,current particles have many limitations in applications,such as insufficient plugging strength and slow degradation *** this paper,a degradable pre-formed particle gel(DPPG)was *** results show that the DPPG has an excellent static swelling effect and self-degradation *** a decrease in the concentration of total monomers or cross-linker,the swelling volume of the synthesized DPPG gradually ***,the entire self-degradation time gradually *** increase in 2-acrylamide-2-methylpropanesulfonic acid(AMPS)in the DPPG composition can significantly increase its swelling ratio and shorten the self-degradation ***,DPPG has excellent high-temperature resistance(150°C)and high-salinity resistance(200,000 mg/L NaCl).Core displacement results show that the DPPG has a perfect plugging effect in the porous media(the plugging pressure gradient was as high as 21.12 MPa),and the damage to the formation after degradation is incredibly ***,the DPPG can be used as an up-and-coming TPA in oil fields.

关键词： Temporary plugging agents Pre-formed particle gel(PPG) Degradable PPG Petroleum drilling Petroleum production

Number estimation of controllers for pinning a complex dynamical network

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第6期12卷 470-477页

作者： Lei WANG Huan SHI You-xian sun School of Mathematics and Systems Science and LMIB Beihang University Beijing 100191 China State Key Lab of Industrial Control Technology Institute of Industrial Process Control Zhejiang University Hangzhou 310027 China

Number estimation of controllers is a fundamental question in pinning synchronization of complex networks. This paper studies the problem of controller number in synchronizing a complex network of coupled dynamical systems by means of pinning. For a complex network with a symmetric coupling matrix and full coupling between the nodes, we formulate network synchronization via pinning as a linear matrix inequality criterion, and provide a lower bound and an upper bound of the controller number for a given complex network with fixed architecture. Several numerical examples with Barabási-Albert network topologies are provided to verify our theoretical results.

关键词： Pinning control Number estimation Synchronization Complex networks