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A 12-bit multichannel ADC for pixel detectors in particle physics and nuclear imaging

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Science China(Technological sciences) 2010年第5期53卷 1208-1214页

作者： WEI Wei1,2,3,WANG Zheng1,3 & ZHAO JingWei1,3 1 Institute of High Energy Physics,chinese Academy of sciences,Beijing 100049,China 2 graduate University of chinese Academy of sciences,Beijing 100049,China 3 Key Lab of Nuclear Detection Technology and Nuclear Electronics of chinese Academy of sciences,Beijing 100049,China Institute of High Energy Physics Chinese Academy of Sciences Beijing China graduate University of chinese Academy of sciences Beijing China Key Lab of Nuclear Detection Technology and Nuclear Electronics of chinese Academy of sciences Beijing China

Modern pixel detectors in nuclear and particle physics experiments and also in nuclear imaging,starve for highly integrated application specified integrated circuit(ASIC),whereas in China the study of ASIC still stays far away from practical *** lack of ASIC strictly limits the research and development of domestic high energy physics field.A 12-bit multichannel ADC designed for high density readout is introduced as a major candidate for solution.A precise model is discussed and the simulation fully agrees with the model,which indicates a key principle of *** is performed according to the given rule,and novel layout techniques are carried *** results in all aspects are also obtained,showing an excellent real performance,which satisfies the practical requirement.

关键词： application specified integrated circuit high density readout Wilkinson ADC multi-channel ADC

Rational redesign of inhibitors of furin/kexin processing proteases by electrostatic mutations

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Acta Pharmacologica Sinica 2004年第12期25卷 146-152页

作者： Xiao-hui CAI, Qing ZHANG, Da-fu DING2 Key Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological sciences, chinese Academy of sciences, graduate school of the chinese Academy of sciences, Shanghai 200031, China 中科院上海生命科学院 Key Laboratory of Proteomics CAS 上海 200031

AIM: To model the three-dimensional structure and investigatethe interaction mechanism ofthe proprotein convertase furin/kexin and their inhibitors (eglin c mutants). METHODS: The three-dimensional complex structures of furin/ kexin with its inhibitors, eglin c mutants, were generated by modeller program using the newly published X-ray crystallographical structures of mouse furin and yeast kexin as templates. The electrostatic interaction energy of each complex was calculated and the results were compared with the experimentally determined inhibition con- stants to find the correlation between them. RESULTS: High quality models of furin/kexin-eglin c mutants were obtained and used for calculation of the electrostatic interaction energies between the proteases and their inhibitors. The calculated electrostaticenergies of interaction showeda linear correlation to the experimental inhibition constants. CONCLUSION: The modeled structures give good explanations of the specificity of eglin c mutants to furin/ kexin. The electrostatic interactions play important roles in inhibitory activity of eglin c mutants to furin/kexin. The results presented here provided quantitative structural and functional information concerning the role of the charge- charge interactions in the binding of furin/kexin and their inhibitors.

关键词： furin kexin eglin c drug design electrostatic mutation

Thermal analysis of the baffle structure of the Solar Space Telescope

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Science China(Physics,Mechanics & Astronomy) 2010年第9期53卷 1755-1764页

作者： LI Rong1,2,3 & WANG Sen1,3 1 National Astronomical Observatories,chinese Academy of sciences,Beijing 100012,China 2 graduate University of chinese Academy of sciences,Beijing 100049,China 3 Key Laboratory of Solar Activity,National Astronomical Observatories of chinese Academy of sciences,Beijing 100012,China National Astronomical Observatories Chinese Academy of Sciences Beijing China graduate University of chinese Academy of sciences Beijing China Key Laboratory of Solar Activity National Astronomical Observatories of Chinese Academy of Sciences Beijing China

The SST(Space Solar Telescope) is an astronomical telescope with a primary mirror of 1 m in *** observes the sun with a small view field to ensure that its high spatial resolution imaging has 0.1″-0.15″ and high SNR(signal to noise ratio).Surrounding the small view field is still the sun,which is an intense source of both heat and stray *** baffles(the main baffle,the aperture,and the outer baffle),which are used to eliminate the stray light,will change the thermal flux in the SST and will weaken the effect of the thermal control *** this study,the compatibility analysis of the thermal effect of baffle structures in SST is *** GCF(Geometry Composing Function) and BRDF(Bidirectional Reflectance Distribution Function),which are two inherent related parameters in the compatibility analysis,are *** objective and method of the compatibility analysis are *** the thermal analysis software,the temperature fields are calculated for different lengths of the main baffle,different radii of apertures,different lengths of the outer baffle with a 3' tilt angle and 16' tilt angle,and different tilt angles of the outer baffle with a 200 mm length.A series of configurations and sizes of the baffles are studied with the goals of both thermal control and elimination of stray *** design of the baffle structure of SST is achieved:the main baffle of length 4100 mm,the internal shield of radius 494 mm,the outer baffle of length 200 mm,and the outer baffle of tilt angle 3' are successfully *** paper presents the relationship between the thermal control design and stray light elimination plan in the *** aims of the optimal design of the baffle structure of SST are *** thoughts and methods of the optimal analysis are also useful for similar optical telescopes designed for solar observation.

关键词： baffle the main baffle the outer baffle GCF BRDF

Nerve Growth Factor Prevents the Apoptosis-associated Increase in Acetylcholinesterase Activity after Hydrogen Peroxide Treatment by Activating Akt

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Acta Biochimica et Biophysica Sinica 2007年第1期39卷 46-56页

作者： Hua JIANG~(1,3) Jingya ZHANG~(1,3) Hui ZHU~(1,3) Hong LI~2 and Xuejun ZHANG~1 ~1Laboratory of Molecular Cell Biology,Institute of Biochemistry and Cell Biology,Shangha Institutes for Biological sciences,chinese Academy of sciences,Shanghai 200031,China ~2DEFEMA,Faculté de Medecine et de Pharmacie,University of Rouen,Rouen 76821,France ~3graduate school of the chinese Academy of sciences,Beijing 100080,China Laboratory of Molecular Cell Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of SciencesShanghai 200031 China graduate school of the chinese Academy of sciences Beijing 100080 China DEFEMA Faculté de Medecine et de Pharmacie University of RouenRouen 76821 France

Acetylcholinesterase （ACHE） is thought to play an important role during *** resultsshowed that H2O2induced AChE activity,a functional marker in apoptosis,increases in neuronal-like PC ***, which is involved in cellular redox homeostasis,inhibited the increase of AChE activity,suggesting that reactive oxygen species （ROS） play a key role in this *** investigation showedthat the elevation of AChE was observed after the degradation of Akt, release of cytochrome c from mitochondriainto the cytosol,and activation of caspase family *** nerve growth factor （NGF） was present,with the maintenance of Akt level,the elevation of AChE,the cytochrome c diffusion,as well as apoptosiswere markedly attenuated in H202-treated PC 12 cells. However,wortmannin,an inhibitor of the PI3K/Aktpathway,accelerated the apoptosis and increased the AChE *** overexpression of constitutivelyactivated Akt,which is a downstream signalling element of the NGF receptor TrkA,delayed mitochondrialcollapse and inhibited elevation of AChE ***, NGF prevented apoptosis and elevation of AChEactivity by activating the Akt pathway and stabilizing the function of mitochondria.

关键词： acetylcholinesterase(AChE) reactive oxygen species(ROS) Akt apoptosis

The relation between black hole masses and Lorentz factors of the jet components in blazars

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Research in Astronomy and Astrophysics 2009年第3期9卷 293-301页

作者： Ming Zhou1,2,3 and Xin-Wu Cao1,2 1 Shanghai Astronomical Observatory, chinese Academy of sciences, Shanghai 200030, China 2 Joint Institute for Galaxy and Cosmology (JOINGC) of SHAO and USMC, Shanghai 200030, China 3 graduate school of the chinese Academy of sciences, Beijing 100049, China Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China Joint Institute for Galaxy and Cosmology (JOINGC) of SHAO and USMC Shanghai 200030 China graduate school of the chinese Academy of sciences Beijing 100049 China

We explore the relationship between black hole mass (MBH) and the motion of the jet components for a sample of blazars. The Very Long Baseline Array (VLBA) 2 cm Survey and its continuation: Monitoring of Jets in active galactic nuclei (AGNs) with VLBA Experiments (MOJAVE) have observed 278 radio-loud AGNs, of which 146 blazars have reliable measurements of their apparent velocities of the jet components. We calculate the minimal Lorentz factors for these sources from their measured apparent velocities, and their black hole masses are estimated with their broad-line widths. A sig- nificant intrinsic correlation is found between black hole masses and the minimal Lorentz factors of the jet components. The Eddington ratio is only weakly correlated with the min- imal Lorentz factor, which may imply that the Blandford-Znajek (BZ) mechanism may dominate over the Blandford-Payne (BP) mechanism for the jet acceleration (at least) in blazars.

关键词： black hole physics — galaxies: active — galaxies: jets — galaxies: nuclei

Sequence analysis of mRNA polyadenylation signals of rice genes

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chinese Science Bulletin 2006年第9期51卷 1069-1077页

作者： LU Ying1, 2, GAO Chenxi1,2,3 & HAN Bin1,3,41. National Center for Gene Research, Shanghai Institutes for Biological sciences, chinese Academy of sciences, Shanghai 200233, China 2. graduate school of the chinese Academy of sciences, Beijing 100039, China 3. Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological sciences, chinese Academy of sciences, Shanghai 200032, China National Center for Gene Research Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China graduate school of the chinese Academy of sciences Beijing China Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China

The formation of eukaryotic mRNAs involves the cleavage and polyadenylation of pre- mRNAs. To investigate the sequence requirement of putative polyadenylation signals (PASs), poly(A) sites and downstream elements (DUEs) in 3′-end-pro- cessing in rice, we compared expressed sequences tags (ESTs) with poly(A) extremity to full-length cDNA sequences and constructed a database of 12969 pre- mRNA sequences in ?40―+40 nt surrounding the poly(A) sites, which were from 9953 genes. The al- ternative poly(A) sites were revealed in approxi- mately 25% of mRNAs. Nearly 80% of pre-mRNAs showed stringent requirement of the YA (CA or UA) at poly (A) sites for polyadenylation. About 7.9% had the AAUAAA signals on ?40―?1 nt upstream of the poly(A) sites. Over 60% of mRNAs probably used the one- or two-base variants of AAUAAA hexamers as their PASs in 3′ fragments. The single-base variants of AAUGAA revealed the high frequency in 11.5% of 3′ fragments. The DUEs were detected in 90% of pre- mRNAs, especially more than half of the pre-mRNAs with multi-base variants of AAUAAA had the DUEs surrounding the poly(A) site. The location of DUE is also important for defining the cleavage site. Al- though most of the rice pre-mRNAs did not contain AAUAAA signal, the existence of downstream ele- ments ensured the efficiency of cleavage-polyade-

关键词：多聚腺苷酸序列分析 mRNA 水稻基因工程

Genetic fingerprinting of plankton community provides new insights into aquatic ecology

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Progress in Natural Science:Materials International 2006年第9期16卷 893-898页

作者： YAN Qingyun, YU Yuhe and FENG Weisong ( Institute of Hydrobiology, chinese Academy of sciences, Wuhan 430072, China graduate school of the chinese Academy of Sci-ences, Beijing 100039, China) Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China graduate school of the chinese Academy of sciences Beijing 100039 China

Over the past two decades, molecular techniques have been widely used in ecological study and molecular ecology has been one of the most important branches of ecology. Meanwhile, genetic fingerprinting analyses have significantly enhanced our knowledge of the diversity and evolutionary relations of the planktonic organisms. Compared with conventional approaches in ecological study (e.g. morphological classification), genetic fingerprinting techniques are simpler and much more effective. This review provides an overview of the principles, advantages and limitations of the commonly used DNA fingerprinting techniques in plankton research. The aim of this overview is to assess where we have been, where we are now and what the future holds for solving aquatic ecological problems with molecular-level information.

关键词： genetic fingerprinting plankton community aquatic ecology genetic diversity.

Contributions of phosphatase and microbial activity to internal phosphorus loading and their relation to lake eutrophication

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Science China Earth sciences 2006年第Z1期49卷 102-113页

作者： SONG Chunlei, CAO Xiuyun, LI Jianqiu, LI Qingman, CHEN Guoyuan & ZHOU Yiyong Institute of Hydrobiology, chinese Academy of sciences, Wuhan 430072, China graduate school of the chinese Academy of sciences, Beijing 100039, China Institute of Hydrobiology Chinese Academy of Sciences Wuhan China graduate school of the chinese Academy of sciences Beijing China

Phosphatase may accelerate the process of lake eutrophication through improving phosphorus bioavailability. This mechanism was studied in three chinese eutrophic shallow lakes (Lake Taihu, Lake Longyang and Lake Lianhua). Phosphatase activity was related to the concentration of soluble reactive phosphorus (SRP) and chlorophyll a. Stability of dissolved phosphatase in reverse micelles may be attributed to molecular size, conformation and active residues of the *** the site with Microcystis bloomed in Lake Taihu, dissolved phosphatase activity was higher and more stable in micelles, SRP concentrations were lower in interstitial water, the contents of different forms of phosphorus and the amounts of aerobic bacteria were lower while respiration efficiency was higher in sediments. Phosphobacteria, both inorganic and organic and other microorganisms were abundant in surface water but rare in sediments. Therefore, internal phosphorus may substantially flux into water column by enzymatic hydrolysis and anaerobic release, together with mobility of bacteria,thereby initiating the bloom. In short, biological mechanism may act in concert with physical and chemical factors to drive the internal phosphorus release and accelerate lake eutrophication.

关键词： dissolved phosphatase, reverse micelle, internal loading, phosphorus form of sediment, microbiology, eutrophication, Microcystis bloom.

Searching for Potential Drug Targets in Two-component and Phosphorelay Signal-transduction Systems using Three-dimensional Cluster Analysis

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Acta Biochimica et Biophysica Sinica 2005年第5期37卷 293-302页

作者： Xiao-Hui CAI Qing ZHANG Shuo-Yong SHI Da-Fu DING Key Laboratory of Proteonmics,Institute of Biochemistry and Cell Biology,Stanghai Institutes for Biological sciences, chinese Academy of sciences,graduate school of the chinese Academy of sciences, Shanghai 200031,China Key Laboratory of Proteomics Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Graduate School of the Chinese Academy of SciencesShanghai 200031 China

Two-component and phosphorelay signal transduction systems are central components in thevirulence and antimicrobial resistance responses of a number of bacterial and fungal pathogens;in somecases,these systems are essential for bacterial growth and ***,we analyze in detail the conservedsurface residue clusters in the phosphotransferase domain of histidine kinases and the regulatory domain ofresponse regulators by using complex structure-based three-dimensional cluster *** also investigatethe protein-protein interactions that these residue clusters participate *** Spo0B-Spo0F complex structurewas used as the reference structure,and the multiple aligned sequences of phosphotransferases and responseregulators were paired *** results show that a contiguous conserved residue cluster isformed around the active site,which crosses the interface of histidine kinases and response *** residue clusters of phosphotransferase and the regulatory domains are directly involved in thefunctional implementation of two-component signal transduction systems and are good targets for thedevelopment of novel antimicrobial agents.

关键词： two-component system phosphorelay histidine kinase response regulator three-dimensional cluster analysis