检索结果-南通市图书馆

Interferon-α enhances sensitivity of human osteosarcoma U2.S cells to doxorubicin by p53-dependent apoptosis

Acta Pharmacologica Sinica 2007年第11期28卷 1835-1841页

作者： Xiang-wei YUAN~2.Xiao-feng ZHU~(3,5),Xiu-fang HUANG~4,Pu-yi SHENG~2.Ai-shan HE~2.Zi-bo YANG~2.Rong DENG~3,Gong-kanFENG~3,Wei-ming LIAO~(2.5)~2.department of Orthopedic Surgery,the fir.t Affiliated {2.,Sun yat-sen university,guangzhou 510080,china ~3 State Key Laboratoryof Oncology in South china,Cancer Center,Sun yat-sen university,{12. 510060,china ~4 department of Pathology,the AffiliatedJiangmen {2.,Sun yat-sen university,Jiangmen 52.030,china department of Orthopedic Surgery The First Affiliated Hospital Sun Yat-sen University Guangzhou 510080 China State Key Laboratory of Oncology in South china Cancer Center Sun Yat-sen University Guangzhou 510060 China department of Pathology The Affiliated Jiangmen Hospital Sun Yat-sen University Jiangmen 529030 China

Aim:to determine whether interferon-α(IFNα) can enhance doxorubicinsensitivity in osteosarcoma cells and its molecular ***:Cellviability was evaluated using 3-(4,5-dimethylthiazol-2.yl)-2.5-diphenyltetrazoliumbromide *** was studied using Flow cytometry analysis,Hoechst332.8 staining,DNA fragmentation assay,as well as the activation ofcaspase-3 and poly (ADP-ribose) *** expression was detectedby Western *** dependence of p53 was determined using ***:IFNα increased doxorubicin-induced cytotoxicity to a muchgreater degree through apoptosis in human osteosarcoma p53-wild U2.S cells,but not p53-mutant MG63 ***α markedly upregulated p53,Bax,Mdm2.andp2.,downregulated Bcl-2.and activated caspase-3 and PARP cleavage in re-sponse to doxorubicin in U2.S ***,the siRNA-mediated silencing ofp53 significantly reduced the IFNα/doxorubicin combination-induced cytotoxic-ity and PARP ***:IFNα enhances the sensitivity of humanosteosarcoma U2.S cells to doxorubicin by p53-dependent *** propercombination with IFNα and conventional chemotherapeutic agents may be a ra-tional strategy for improving the treatment of osteosarcoma with functional p53.

关键词： Interferon-α doxorubicin apoptosis p53 osteosarcoma

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Biorthogonal multiple wavelets generated by vector refinement equation

引用

Science china Mathematics 2007年第7期50卷 1015-1025页

作者： Song LI~(1+) Jun XIAN~2.1 department of Mathematics,Zhejiang university,Hangzhou 31002.,{2. 2.department of Mathematics,Sun yat-sen university,guangzhou 5102.5,{2. 1. department of Mathematics Zhejiang University Hangzhou 310027 China 2. department of Mathematics Sun Yat-Sen University Guangzhou 510275 China

Biorthogonal multiple wavelets are generated from refinable function vectors by using the multiresolution analysis. In this paper we provide a general method for the construction of compactly supported biorthogonal multiple wavelets by refinable function vectors which are the solutions of vector refinement equations of the form $$\varphi (x) = \sum\limits_{\alpha \in \mathbb{Z}^s } {a(\alpha )\varphi (Mx - \alpha ), x \in \mathbb{R}^s } ,$$ where the vector of functions ? = (? 1, …, ? r)t is in $(L_2.(\mathbb{R}^s ))^r ,a = :(a(\alpha ))_{\alpha \in \mathbb{Z}^s } $ is a finitely supported sequence of r × r matrices called the refinement mask, and M is an s × s integer matrix such that lim n→∞ M ?n = 0. Our characterizations are in the general setting and the main results of this paper are the real extensions of some known results.

关键词： refinement equation biorthogonal multiple wavelets refinable function vector 42.40 41A10 41A15 41A2.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

temporal and tight Hepatitis C Virus Gene Activation in Cultured Human Hepatoma Cells Mediated by a Cell-Permeable Cre Recombinase

引用

Acta Biochimica et Biophysica Sinica 2004年第10期36卷 687-694页

作者： Dong XIAO*, Kang XU1, Ying YUE, Zhong-Min GUO, Bing HUANG, Xin-Yan DENG, Huan tANG2. and Xi-Gu CHEN* Center of Experimental Animals, Zhongshan university, {2., china 1the fir.t affiliated hosp.tal of Sun yat-sen university, Zhongshan university, {2., china 2.he third Military Medical university, Chongqing 400010, china Center of Experimental Animals Zhongshan University the fir.t affiliated hosp.tal of Sun {2.-sen university Zhongshan University the third Military Medical university

Conditional gene expression has greatly facilitated the examination of the functions of particular gene products. Using the Cre/lox P switching expression system, we plan to develop efficient conditional transgeneactivation of hepatitis C virus core protein (HCV-C) cDNA (nucleotide 342.914) in the transgenic mice to overcome “immune tolerance” formed during the embryonic period and “immune escape” against hepatitis virus antigen in our project. to use this system in vivo, the dormant transgenic construct, i.e., pApoE-SCS-EGFP-HCV-C, was generated using techniques of standard molecular biology. the liver- specific human apoE promoter was here used to target expression of genes of interest (EGFP and HCV-C) to murine liver. Prior to generating the transgenic mice, the availability of Cre/lox P system and construct functionality were successfully verified by a cell-free recombination system and via checking the expression of EGFP and HCV-C in the human hepatoma cells at the mRNA and protein levels. these results suggest that the Cre/lox P system could tightly control expression of EGFP and HCV-C in vitro, which laid a solid foundation to conditionally activate expression of target gene(s) in transgenic mice by Cre-mediated site-specific recombination.

关键词： hepatitis C virus Cre/lox P switching expression system cell-free and intracellular recombination systems cell-permeable Cre recombinase EGFP human hepatoma cells

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

A provable secure fuzzy identity based signature scheme

引用

Science china(Information Sciences) 2012年第9期55卷 2139-2148页

作者： WANG ChangJi 1,2.1 School of Information Science and technology,Sun yat-sen {2.,guangzhou 5102.5,china 2.Guangdong Province Information Security Key Laboratory,Sun yat-sen {2.,guangzhou 5102.5,china 1. School of Information Science and technology Sun Yat-sen University Guangzhou 510275 China2. Guangdong Province Information Security Key Laboratory Sun Yat-sen University Guangzhou 510275 China

to use biometrics identities in an identity based encryption system,Sahai and Waters fir.t introduced the notion of fuzzy identity based encryption(FIBE) in *** et *** it to digital signature and introduced the concept of fuzzy identity based signature(FIBS) in 2.08,and constructed an FIBS scheme based on Sahai and Waters's FIBE *** this paper,we further formalize the notion and security model of FIBS scheme and propose a new construction of FIBS scheme based on bilinear *** proposed scheme not only provides shorter public parameters,private key and signature,but also have useful structures which result in more efficient verification than that of Yang et al.'s FIBS *** proposed FIBS scheme is proved to be existentially unforgeable under a cho{2. message attack and selective fuzzy identity attack in the random oracle model under the discrete logarithm assumption.

关键词： identity based cryptosystem fuzzy identity based encryption fuzzy identity based signature

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Inactivation gating determines drug potency:a common mechanism for drug blockade of HERG channels

引用

Acta Pharmacologica Sinica 2004年第5期25卷 12-18页

作者： Bao-feng YANG1, Dong-hui XU2. Chao-qian XU, Zhe LI, Zhi-min DU, Hui-zhen WANG, De-li DONGdepartment of Pharmacology, Harbin Medical university, Harbin 150086, {2. 2.0} of Pharmacy, Sun yat-sen university, guangzhou 510080, {2. department of Pharmacology Harbin Medical University department of Pharmacy Sun Yat-sen University

AIM: to determine the mechanisms of interactions between different drugs and HERG channels. MEtHODS:Various antiarrhythmic (dofetilide, quinidine, azimilide, RP58866) and non-antiarrhythmic (terfenadine, nicotine)agents were used on HERG channels expressed in Xenopus oocyte. Whole-cell voltage-clamp techniques wereused. RESULtS: All drugs produced concentration-dependent block of HERG current. the inhibition was mark-edly facilitated with voltage protocols favoring channel inactivation (eg, less negative holding potentials). Maneu-vers that weakened channel inactivation (eg, elevation of external K+), relieved HERG blockade by all drugs. Moreover,the inhibitory potency was reduced by at least 2.-300 fold with varying compounds when rapid C-type inactivationwas removed by a mutation located between the transmembrane domains 5 and 6 (S631A). CONCLUSION: theinactivation gating of HERG channels determines the blocking potency of drugs. this mechanism might be com-mon to drugs of various classes.

关键词： antiarrhythmic agents potassium channels mutation channel inactivation patch-clamp techniques oocytes Xenopus

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Linearly time-varying channel estimation and training power allocation for OFDM/MIMO systems using superimposed training

引用

Science china(Information Sciences) 2011年第7期54卷 1456-1470页

作者： ZHANG Han 1,DAI XianHua 2.& Pan DaRu 1 1 School of Physics and telecommunication Engineering,South china Normal university,{2. 510006,china 2.department of Information Science and technology,SUN yat-sen university,{2. 51002.,china 1. School of Physics and telecommunication Engineering South China Normal University Guangzhou 510006 China2. Department of Information Science and Technology SUN Yat-sen University Guangzhou 510026 China

We address the problem of estimating the linearly time-varying (LtV) channel of orthogonal frequency division multiplexing (OFDM)/multiple-input multiple-output (MIMO) systems using superimposed training (St).the LtV channel is modeled by truncated discrete Fourier *** on this model,a two-step approach is adopted to estimate the LtV channel over multiple OFDM *** also present performance analysis of the channel estimation and derive a closed-form expression for the channel estimation *** is shown that the estimation variances,unlike that of the conventional St-based schemes,approach to a fixed lower-bound as the training length increases,which is directly proportional to information-pilot power *** wireless communication systems with a limited transmission power,we optimize the St power allocation by maximizing the lower bound of the average channel *** results show that the proposed approach outperforms the frequency-division multiplexed training schemes.

关键词： OFDM/MIMO systems linearly time-varying channel estimation superimposed training training power allocation

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Calibration based universal JPEG steganalysis

引用

Science in china(Series F) 2009年第2期52卷 260-268页

作者： HUANG FangJun1,2.& HUANG JiWu1,2.1 School of Information Science and technology,Sun yat-sen {2.,guangzhou 5102.5,china 2.Guangdong Key Lab. of Information Security technology,Sun yat-sen {2.,guangzhou 5102.5,china School of Information Science and technology Sun Yat-Sen University Guangzhou 510275 China Guangdong Key Lab. of Information Security technology Sun Yat-Sen University Guangzhou 510275 China

For steganalysis of JPEG images, features derived in the embedding domain appear to achieve a preferable performance. However, with the existing JPEG steganography, the minor changes due to the hidden secret data are not easy to be explored directly from the quantized block DCt （BDCt） coefficients in that the energy of the carrier image is much larger than that of the hidden signal. In this paper, we present an improved calibration-based universal JPEG steganalysis, where the microscopic and macroscopic calibrations are combined to calibrate the local and global distribution of the quantized BDCt coefficients of the test image. All features in our method are generated from the difference signal be- tween the quantized BDCt coefficients of the test image and its corresponding microscopic calibrated image, or calculated as the difference between the signal extracted from test image and its corresponding macroscopic calibrated image. the extracted features will be more effective for our classification. Moreover, through using the Markov empirical transition matrices, both magnitude and sign dependencies along row scanning and column scanning patterns existed in intra-block and inter-block quantized BDCt coefficients are employed in our method. Experimental results demonstrate that our proposed scheme outperforms the best effective JPEG steganalyzers having been presented.

关键词： JPEG steganography steganalysis microscopic calibration macroscopic calibration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Steganalysis of stochastic modulation steganography

引用

Science in china(Series F) 2006年第3期49卷 273-285页

作者： HE Junhui1,2.& HUANG Jiwu1,2.1. School of Information Science and technology, Sun yat-sen {2., guangzhou 5102.5, china 2. Guangdong Province Key Laboratory of Information Security, guangzhou 5102.5, china 1. School of Information Science and technology Sun Yat-sen University Guangzhou 510275 China 2. Guangdong Province Key Laboratory of Information Security Guangzhou 510275 China

Stochastic modulation steganography embeds secret message within the cover image by adding stego-noise with a specific probabilistic distribution. No method is known to be applicable to the estimation of stochastic modulation steganography. By analyzing the distributions of the horizontal pixel difference of images before and after stochastic modulation embedding, we present a new steganalytic approach to accurately estimate the length of secret message in stochastic modulation steganography. the pro- posed method {2. establishes a model describing the statistical relationship among the differences of the cover image, stego-image and stego-noise. In the case of stegoimage-only steganalysis, rough estimate of the distributional parameters of the cover image＇s pixel difference is obtained with the use of the provided stego-image. And grid search and Chi-square goodness of fit test are exploited to estimate the length of the secret message embedded with stochastic modulation steganography. the experimental results demonstrate that our new approach is effective for steganalyzing stochastic modulation steganography and accurately estimating the length of the secret message.

关键词： information hiding steganography steganalysis stochastic modulation statistical distribution models of difference.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of cyclooxygenase 2.inhibitors on biological traits of nasopharyngeal carcinoma cells

引用

Acta Pharmacologica Sinica 2004年第7期25卷 97-103页

作者： Pei-yi CHEN1, Qi-cai LONG2.Institute of ClinicalPharmacology, School of Pharmaceutical Sciences, Sun yat-sen {2., guangzhou 510080, china1 Now in Inspection, Evaluation and Certification Committee forDrug, Guangdong Province Drug Administration, guangzhou510080, china. Institute of Clinical Pharmacology School of Pharmaceutical Sciences Sun Yat-sen University Guangzhou 510080 Chin

AIM: to investigate effects of cyclooxygenase 2.(COX-2. inhibitors on nasopharyngeal carcinoma (NPC) cells and on angiogenesis in vitro. MEtHODS: Human NPC cell lines (CNE1, CNE2.and SUNE) were treated with nimesulide or celecoxib. Mtt assay and colony formation assay were performed to observe antiproliferation activity of COX-2.inhibitors to NPC cell lines. Cell cycle arrest and apoptosis of NPC cell strains were tested by flow cytometry assay, microscopic morphology observation, and DNA fragmentation assay. the effect of COX- 2.inhibitor on angiogenesis was tested by chick chorioallantoic membrane (CAM) model. RESULtS: Nimesulide (Nim) and celecoxib (Cel) could antiproliferate NPC cell lines with IC50 182.μmol/LNim-SUNE, 78 μmol/LNim-CNE1, 175 μmol/LNim-CNE2. 7.2.μmol/LCel-SUNE, 8.1 μmol/LCel-CNE1, and 7.6 μmol/LCel-CNE2. the antiproliferation presented dose- dependent (Nim5-400 μmol/L, Cel 0.5-80μmol/L) and time-dependent manner (Nim IC50 562.μmol/L2. , 316 μmol/L48 , h h 50.1 μmol/L2.0 ). Nim and Cel arrested SUNE and CNE1 cell cycle at phase G2.M (cell aggregation rate 2..9 %- h 45.1 %Nim 2.-2.0μmol-12.h-SUNE , 18.9%-2..2.%Nim 2.-2.0μmol-2. h-SUNE ,2..8 %-35.6%Nim 2.-2.0 μmol-48 h-SUNE ,30.4 %-16.4%Cel 2.-100μmol-12.h-SUNE , 2..2.%-19.7 %Cel 2.-100 μmol-2. h-SUNE, 31.1 %-19.9 %Cel 2.-100 μmol-2. h-SUNE, 2..5 %-34.1 %Nim2.-2.0 μmol-12.h-CNE1, 2..2.%- 2..9 %Nim 2.-2.0 μmol-2. h-CNE1 , 11.5 %-7.1 %Nim 2.-2.0 μmol-48 h-CNE1). Apoptosis shape and apoptosis strap displayed in NPC cells after treatment with Nim and Cel. Nim had a feature of anti-angiogenesis on CAM model. CONCLUSION: Nim and Cel could suppress proliferation of squamous epithelium NPC cell (SUNE, CNE1 and CNE2. through blocking cell cycle and inducing cell apoptosis. Nim could apparently suppress CAM angiogenesis induced by

关键词： cyclooxygenase inhibitors nimesulide celecoxib nasopharyngeal neoplasms apoptosis cell cycle angiogenesis inhibitors

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

On the diophantine equation X^2.(1+a^2.Y^4 =-2.

引用

Science china Mathematics 2010年第8期53卷 2143-2158页

作者： YUAN PingZhi 1 & ZHANG ZhongFeng 2.1 School of Mathematics,South china Normal university,{2. 510631,china 2.School of Mathematics & Computational Science,Sun yat-sen university,{2. 5102.5,china 1. School of Mathematics South China Normal University Guangzhou 510631 China2. School of Mathematics & Computational Science Sun Yat-Sen University Guangzhou 510275 China

Let a≥1 be an *** this paper,we will prove the equation in the title has at most three positive integer solutions.

关键词： algebraic approximations continued fractions elliptic curves quartic equations

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：