检索结果-南通市图书馆

Performance analysis of a noise-normalized FFH/MFSK receiver over Rayleigh fading channels with partial-band noise jamming

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2011年第1期54卷 129-135页

作者： ZHOU ZhiQiang,LI ShaoQian & CHENG YuFan national key laboratory of Science and Technology on communications,University of Electronic Science and Technology of china,chengdu 610054,china 1. national key laboratory of Science and Technology on communications University of Electronic Science and Technology of China Chengdu 610054 China

Fast frequency hopping can reduce the degradation caused by *** performance of noise-normalized fast frequency-hopped M-ary orthogonal frequency-shift-keying(FFH/MFSK)receivers over frequency nonselective Rayleigh fading channels with partial-band noise jamming is *** of numerical evaluation,a closed-form error probability expression is given based on the theory of complex variables. The simulation results validate the analytical *** is shown that there is an optimum diversity order and the system performance gets better with an increase in the modulation order.

关键词： anti-jamming fast frequency hopping noise normalization combining Rayleigh fading

An optimized non-unitary linear precoding design for OSTBCs

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2010年第2期53卷 335-343页

作者： HUANG HaiYang , WU Gang, LU Lu & LI ShaoQian national key laboratory of communications, University of Electronic Science and Technology of china, chengdu 610054, china 1. national key laboratory of communications University of Electronic Science and Technology of China Chengdu 610054 China

This paper tackles the optimization of non-unitary linear precoding design for orthogonal spacetime block codes (OSTBCs). We dig out the transmission potentials by the analysis from eigen-space point of view according to the unique structure of OSTBCs. The proposed precoding form is proven to be theoretically optimized. Compared with the classical unitary Grassmannian codebook design, the non-unitary codebook further improves the overall performance of practical systems. The constraint on codebook size to guarantee full diversity order is given and proven. Based on this, we investigate the codebook construction method combined with a water-filling (WF) technique to reduce the impact of antenna correlation. The advantages of the novel design are verified via numerical simulations.

关键词： multi-antenna linear precoding OSTBCs non-unitary design antenna correlation

The metabolic switch and its regulation in cancer cells

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Life Sciences) 2010年第8期53卷 942-958页

作者： ZHOU ShengTao, HUANG CanHua & WEI YuQuan State key laboratory of Biotherapy, West china Hospital, Sichuan University, chengdu 610041, china 1. State key laboratory of Biotherapy West China Hospital Sichuan University Chengdu 610041 China

The primary features of cancer are maintained via intrinsically modified metabolic activity, which is characterized by enhanced nutrient supply, energy production, and biosynthetic activity to synthesize a variety of macromolecular components during each passage through the cell cycle. This metabolic shift in transformed cells, as compared with non-proliferating cells, in-volves aberrant activation of aerobic glycolysis, de novo lipid biosynthesis and glutamine-dependent anaplerosis to fuel robust cell growth and proliferation. Here, we discuss the unique metabolic characteristics of cancer, the constitutive regulation of metabolism through a variety of signal transduction pathways and/or enzymes involved in metabolic reprogramming in cancer cells, and their implications in cancer diagnosis and therapy.

关键词： aerobic glycolysis cancer de novo fatty acid synthesis glutaminolysis metabolism

Performance analysis of peak cancellation in OFDM systems

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2012年第4期55卷 789-794页

作者： XIAO Yue,BAI WenLing,DAN LiLin,WU Gang & LI ShaoQian national key laboratory of Science and Technology on communications,University of Electronic Science and Technology of china,chengdu 610054,china 1. national key laboratory of Science and Technology on communications University of Electronic Science and Technology of China Chengdu 610054 China

Peak cancellation is a class of peak-to-average power ratio (PAPR) reduction techniques for orthogo-nal frequency division multiplexing (OFDM).It can control the PAPR and out-of-band radiation simultaneously at the cost of additional *** this paper,the interference of peak cancellation is modeled and an-alyzed so as to evaluate the degradation of system ***,through theoretical analysis,a closed form of the BER performance is derived for OFDM with popular modulation schemes such as QPSK and ***,the analytical results are verified by simulations.

关键词： OFDM peak cancellation PAPR

A 2~n scaling scheme for signed RNS integers and its VLSI implementation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2010年第1期53卷 203-212页

作者： MA Shang, HU JianHao, YE YanLong, ZHANG Lin & LING Xiang national key laboratory of Science and Technology on communications, University of Electronic Science and Technology of china, chengdu 611731, china 1. national key laboratory of Science and Technology on communications University of Electronic Science and Technology of China Chengdu 611731 China

High effcient implementation of scaling in residue number system (RNS) is one of the critical issues for the applications of RNS in digital signal processing (DSP) systems. In this paper, an effcient scaling algorithm for signed integers in RNS is proposed firstly through introducing a correction constant in negative integers scaling procedure. Based on the proposed scaling algorithm, an effcient RNS 2n scaling implementation method is presented, in which Chinese remainder theorem (CRT) and a redundant modulus are used to perform the base extension to obtain the least significant n bits of RNS integers. With the redundant modulus, the RNS sign detection can be achieved by the parity detection. And then, an approach to update the residue digit of the redundant channel is also proposed. Meanwhile, this paper provides a method of computing the correction constant of the redundant channel in negative integers scaling. The analysis results indicate that the complexity of the proposed scaling algorithm grows linearly with the word-length of the RNS dynamic range without using Look-up Table (LUT). Furthermore, the proposed algorithm is employed for a specific moduli set 2n scaling. The synthesis results show that the critical path of the proposed algorithm is shortened by 12%, the area and power consumption performance is improved by about 35%, compared to the existing cascading 2n scaling method for very large scale integration (VLSI) implementation under the same restriction. Besides, the VLSI layout indicates that the parallel structure is simpler.

关键词： RNS VLSI scaling CRT base extension sign detection

A Novel Missense Mutation(L296Q)in Cholesteryl Ester Transfer Protein Gene Related to Coronary Heart Disease

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第1期36卷 33-36页

作者： Ke-Qin ZHENG, Si-Zhong ZHANG, Li ZHANG, De-Jia HUANG, Lin-Chuan LIAO, and Yi-Ping HOU ( Department of Medical Genetics, West china Hospital Division of Human Morbid Genomics, key laboratory ofBiotherapy of Human Diseases of Ministry of Education, Sichuan University, chengdu 610041, china Department of Cardiology, West china Hospital, Sichuan University, chengdu 610041, china School of Basic and Forensic Medicine, Sichuan University, chengdu 610041, china) Department of Medical Genetics West China Hospita Division of Human Morbid Genomics Key Laboratory of Biotherapy of Human Diseases of Ministry of Education Sichuan University Chengdu 610041 Chin

Cholesteryl ester transfer protein (CETP) is a key participant in the reverse transport of cholesterol from the peripheral tissues to the liver. To understand the role that CETP gene plays in the pathogenesis of coronary heart disease (CHD) , the promoter region, all 16 exons and adjacent intronic regions of CETP gene were screened for single nucleotide polymorphisms (SNPs) in 203 CHD patients and 209 controls by a combination of PCR, denaturing high performance liquid chromatography (DHPLC), molecular cloning, and DNA sequencing. A novel missense mutation in the CETP gene was identified. This mutation (L296Q) was a T-to-A conversion at codon 296 of exon 10 which replaced the codon for leucine (CTG) with the codon for glutamine (CAG). Association study revealed that L296Q mutation was associated with CHD with a significantly higher mutant allele frequency in the CHD patients than that in the controls (0. 160 vs. 0.091,x2= 9.014, P = 0.003), and that the odds ratio for the development of CHD was 1.83 for

关键词： cholesteryl ester transfer protein gene (CETP gene) coronary heart disease (CHD) missense mutation plasma lipids single nucleoti.de polymorphism (SNP)

Proteomics profile changes in cisplatin-treated human ovarian cancer cell strain

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Life Sciences) 2005年第6期48卷 648-657页

作者： LI Zhengyu1, ZHAO Xia1, YANG Jinliang2 & WEI Yuquan2 1. Department of Gynecology and Obstetrics, West china Second Hospital of Sichuan University, chengdu 610041, china 2. national key laboratory of Biotherapy of Human Diseases, West china Hospital of Sichuan University, chengdu 610041, china 1. Department of Gynecology and Obstetrics West China Second Hospital of Sichuan University 610041 Chengdu China 2. national key laboratory of Biotherapy of Human Diseases West China Hospital of Sichuan University 610041 Chengdu China

To compare the alterations in proteomes between cisplatin-treated and -untreated human ovarian cancer SKOV3 cells, and to explore the feasibility of proteomics in research about antitumor mechanisms of agents, SKOV3 cells were exposed to cisplatin (6 μg/mL) for 6 h. Then, the cells were collected and solubilized and global proteins were extracted by lysis buffer; two-dimensional electrophoresis was conducted with the IPG readystrips as carriers; the gels were stained with Coomassie blue and alterations between gels were compared by PDQuest. Eventually, 11 spots with significant differences were selected and excised and the proteins were identified by PMF and MS/MS analysis. The results revealed that exposure to cisplatin could notably increase expressions of some proteins, such as tropomyosin family, actin family, trio-sephosphate isomerase family, and HSP60, etc.; while expressions of some other proteins de-creased, such as enolase family, etc. Those proteins were involved in cellular energy metabolism, transformation, apoptosis and morphologic maintenance, which suggested that alterations of those physiological processes might be involved in anti-tumor mechanism of cisplatin.

关键词： proteomics, cisplatin, ovarian cancer, 2-D electrophoresis, mass spectrometry.

Cardiac nonrigid motion analysis from image sequences

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第10期16卷 1115-1118页

作者： LIU Huafeng (State key laboratory of modern Optical Instrumentation, Zhejiang University, Hangzhou 310027, china) [a]State key laboratory of modern Optical Instrumentation Zhhejiang University Hangzhou China

Noninvasive estimation of the soft tissue kinematics properties from medical image sequences has many important clinical and physiological implications, such as the diagnosis of heart diseases and the understanding of cardiac mechanics. In this paper, we present a biomechanics based strategy, framed as a priori constraints for the ill-posed motion recovery problems, to realize estimation of the cardiac motion and deformation parameters. By constructing the heart dynamics system equations from biomechanics principles, we use the finite element method to generate smooth estimates of heart kinematics throughout the cardiac cycle. We present the application of the strategy to the estimation of displacements and strains from in vivo left ventricular magnetic resonance image sequence.

关键词： cardiac motion and deformation continnum mechanics model finite element method.

Regulation of apoptotic signal transduction pathways by the heat shock proteins

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Life Sciences) 2004年第2期47卷 107-114页

作者： LI Zhengyu1, ZHAO Xia1 & WEI Yuquan2 1. Department of Gynecology and Obstetrics, West china Second Hospital of Sichuan University, chengdu 610041, china 2. key laboratory of Biotherapy of Human Diseases of Ministry of Education, West china Hospital of Sichuan university, chengdu 610041, china 1. Department of Gynecology and Obstetrics West China Second Hospital of Sichuan University 610041 Chengdu China 2. key laboratory of Biotherapy of Human Diseases of Ministry of Education West China Hospital of Sichuan university 610041 Chengdu China

The study about apoptotic signal transductions has become a project to reveal the molecular mechanisms of apoptosis. Heat shock proteins (hsps), which play an important role in cell growth and apoptosis, have attracted great attentions. A lot of researches have showed there is a hsps superfamily including hsp90, hsp70, hsp60 and hsp27, etc., which regulates the bio-logical behaviors of cells, particularly apoptotic signal transduction in Fas pathway, JNK/SAPK pathway and caspases pathway at different levels, partly by the function of molecular chaperone.

关键词： heat shock protein, apoptotic signal transduction, molecular chaperone, caspases.