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Large field of view computed laminography with the asymmetric rotational scanning geometry

Science china(Technological Sciences) 2010年第8期53卷 2261-2271页

作者： FU Jian 1,2 ,JIANG BaiHong&LI Bin 1 School of Mechanical Engineering and Automation,Beihang University,beijing 100191,china 2 Research center of Digital radiation Imaging and Biomedical Imaging,Beihang University,beijing 100191,china School of Mechanical Engineering and Automation Beihang University Beijing China Research center of Digital radiation Imaging and Biomedical Imaging Beihang University Beijing China

X-ray computed laminography(CL)is used in the fields of industrial inspection and medical *** can provide the internal structure three-dimensional(3D)information of a region of the objects *** is important to the clinical diagnosis and the quality control of flat objects like printed circuit boards,aircraft wings and satellite solar *** the restriction that the imaging region must be within the X-ray beam formed by the X-ray source and the detector,the imaging field of view of CL is limited by the size of detector.A new CL method with an asymmetric rotational cone-beam scanning geometry,called large field of view CL,is presented to overcome the existing *** can extend the imaging region when the imaging spatial resolution keeps the same as that of the conventional *** can also improve the imaging spatial resolution when the imaging region keeps the same as that of the conventional *** asymmetric configuration can be achieved by offsetting the detector from the conventional symmetric *** does not,however,require new detectors and X-ray source nor alter the scanning mechanical *** filtered back-projection(FBP)reconstruction algorithm and the data truncation smoothing functions have been deduced to reconstruct the images directly from the data acquired with this asymmetric *** performed numerical studies and experiments to demonstrate and validate the proposed approach. Results in these studies and experiments confirm that the proposed method can enlarge the imaging region and improve the spatial *** proposed approach may find applications in the CL system with the rotational scanning geometry.

关键词： computed laminography image reconstruction reconstruction algorithm imaging field of view imaging spatial resolution

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Effect of wortmannin and 3-AB on G_2 phase arrest and transient failure to activate MPF induced by ionizing irradiation

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Chinese Science Bulletin 1998年第18期43卷 1550-1555页

作者： MENG Xiangbing and SUN Zhixian beijing Institute of radiation Medicine, beijing 100850, china beijing Institute of radiation Medicine Beijing China

Active mitosis promoting factor (MPF) composed of p34 cdc2 with cyclin B1 is required for the cell cycle transition from G 2 to M phase. Recent studies have demonstrated that ionizing radiation (IR) exposures associated with inhibition of p34 cdc2 activity was the mechanism of G 2 arrest. At low dose, IR causes transient failure to dephosphorylate p34 cdc2 instead of suppression of cyclin B or MPF formation of cyclin B with p34 cdc2 complex. But the signaling events that regulate p34 cdc2 in irradiated cells remain unclear. This note demonstrates that PI3 kinase family inhibitor wortmannin (wort) and PARP specific inhibitor 3_AB can reduce the G 2 arrest induced by 2Gy γ_ray. Immunoprecipitation studies demonstrate that wort and 3_AB can facilitate dephosphorylation of p34 cdc2 in G 2 phase arrest induced by radiation. These findings suggest that wort sensitive pathway and PARP may be involved in initiating the signal transduction of G 2 phase arrest caused by IR.

关键词： G 2 phase arrest ionizing radiation MPF wortmannin 3_AB.

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Constraints of f(R) gravity in Palatini approach with observational Hubble data

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Science china(Physics,Mechanics & Astronomy) 2011年第8期54卷 1378-1383页

作者： ZHAI ZhongXu & LIU WenBiao Department of Physics, Institute of Theoretical Physics, beijing Normal University, beijing 100875, china Department of Physics Institute of Theoretical Physics Beijing Normal University Beijing China

We use the newly released observational H(z) data (OHD), the Cosmic Microwave Background (CMB) shift parameter, and the Baryon Acoustic Oscillation (BAO) measurements data to constrain cosmological parameters of f(R) gravity in Palatini formalism in which the f(R) form is defined as f(R) = R β/Rn. Under the assumption of a spatially flat FRW universe, we get the best fitting results of the free parameters (Ωm0, n). In the calculation, we marginalize the likelihood function over H0 by integrating the probability density P ∝ e-χ2/2 to obtain the best fitting results and the confidence regions in the Ωm0-n plane. The constraints results of (Ωm0, n) = (0.33, 0.41) by OHD only and (Ωm0, n) = (0.23, 0.08) by the combination of OHD+CMB+BAO both indicate that the universe goes through three last phases, i.e., radiation dominated, matter-dominated, and late time accelerated expansion without introduction of dark energy.

关键词： f(R) gravity OHD CMB BAO accelerating expansion dark energy

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Bioinformatics analyses for signal transduction networks

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Science china(Life Sciences) 2008年第11期51卷 994-1002页

作者： LIU Wei1,2, LI Dong2, ZHU YunPing2 & HE FuChu1,2 1 College of Mechanical & Electronic Engineering and Automatization, National University of Defense Technology, Changsha 410073, china 2 State Key Laboratory of Proteomics, beijing Proteome Research center, beijing Institute of radiation Medicine, beijing 102206, china College of Mechanical & Electronic Engineering and Automatization National University of Defense Technology Changsha China State Key Laboratory of Proteomics Beijing Proteome Research Center Beijing Institute of Radiation Medicine Beijing China

Research in signaling networks contributes to a deeper understanding of organism living activities. With the development of experimental methods in the signal transduction field, more and more mechanisms of signaling pathways have been discovered. This paper introduces such popular bioin-formatics analysis methods for signaling networks as the common mechanism of signaling pathways and database resource on the Internet, summerizes the methods of analyzing the structural properties of networks, including structural Motif finding and automated pathways generation, and discusses the modeling and simulation of signaling networks in detail, as well as the research situation and tendency in this area. Now the investigation of signal transduction is developing from small-scale experiments to large-scale network analysis, and dynamic simulation of networks is closer to the real system. With the investigation going deeper than ever, the bioinformatics analysis of signal transduction would have immense space for development and application.

关键词： signal transduction structural motif automated pathways regeneration dynamics simulation

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Technical development of proteomics

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Chinese Science Bulletin 1999年第16期44卷 1441-1447页

作者： WAN Jinghong and HE Fuchu1.Chongqing Medical University, Chongqing 400046, china 2. beijing Institute of radiation Medicine, beijing 100850, china Corresponding author Chongqing Medical University Chongqing China beijing Institute of radiation Medicine Beijing China

Proteome research is an important complementarity for the genome research, which uses quantitative protein-level measurements to characterize biological process. Proteome techniques include two aspects. One is two-dimensional electrophoresis, which is the unique technology to separate the components of proteome. The other is identification of the

关键词： proteome two-dimensional electrophoresis image analysis peptide-mass fingerprinting database.

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Proteomics in china:Ready for prime time

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Science china(Life Sciences) 2010年第1期53卷 22-33页

作者： GAO Xue1,ZHANG XueLi1,ZHENG JunJie1 & HE FuChu1,2 1 State Key Laboratory of Proteomics,beijing Proteome Research center,beijing Institute of radiation Medicine,beijing 102206,china 2 Institutes of Biomedical Sciences,Fudan University,Shanghai 200032,china State Key Laboratory of Proteomics Beijing Proteome Research Center Beijing Institute of Radiation Medicine Beijing China Institutes of Biomedical Sciences Fudan University Shanghai China

Proteomics is a newborn science focusing on the comprehensive systematic analysis of all proteins in molecule machineries,organelles,cells,tissues,organs or intact *** has been becoming one of the focuses in life sciences and cutting-edge techniques in biotechnologies in the 21st *** the last decade,proteomics in china has developed much faster than other developing fields in the life *** review article briefly retrospects the origin and development of proteomics in china,and provides an overview of representative scientific progress and perspectives.

关键词： proteomics progress china Human Proteome Organization Human Liver Proteome Project perspectives

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Properties and applications of embryonic stem cells

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Chinese Science Bulletin 2000年第14期45卷 1258-1265页

作者： GUO Xiaoxia & HE Fuchu1. beijing Institute of radiation Medicine, beijing 100850, china 2. Department of Life Science, Shandong University, Ji’nan 250100, china Correspondence should he addressed to He Fuchu beijing Institute of radiation Medicine Beijing China Department of Life Science Shandong University Ji’nan China

Mouse embryonic stem (ES) cells are pluripotent cells derived from the early embryo and can be propagated stably in undifferentiated state in vitro. They retain the ability to differentiate into all cell types found in the embryonic and adult body in vivo, and can be induced to differentiate into many cell types under appropriate culture conditions in vitro. Using these properties, people have set up various differentiated systems of many cell types and tissues in vitro. Through analysis of these systems, one can identify novel bioactive factors and reveal mechanisms of cell differentiation and organogenesis. ES cell-derived differentiated cells can also be applied to cell transplantation therapy. In addition, we summarized the features and potential applications of human ES cells.

关键词： embryonic stem cell differentiation in vitro cell transplantation therapy gene targeting.

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DNA Damage, Signaling and Repair: Protecting genomic integrity and reducing the risk of human disease

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Chinese Science Bulletin 2011年第30期56卷 3119-3121页

作者： ZHOU PingKun Department of radiation Toxicology and Oncology, beijing Institute of radiation Medicine, beijing 100850, china Special Topic Editor Department of radiation Toxicology and Oncology Beijing Institute of Radiation Medicine Beijing China

DNA is the genetic material that contains the 'instructions' to not only guide the continuation of life but also govern the development, metabolism and functioning of living organisms. DNA damage occurs daily due to v... 详细信息

关键词： DNA损伤基因组伤信号人类疾病整性修复风险保护

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Randomization of protein encoding gene during species evolution

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Chinese Science Bulletin 1998年第4期43卷 299-303页

作者： GE Weiwen 1 and HE Fuchu 2 1. Institute of Hygiene and Environment Medicine, Tianjin 300050, china 2. Institute of radiation Medicine, beijing 100850, china Institute of Hygiene and Environment Medicine Tianjin China Institute of radiation Medicine Beijing China

Employing chi_square test, the authors observed the bias of 4 kinds of bases’ locating in 3 codon positions in gene sequence, and proved that there is a positive correlation between higher chi_square value and protein coding structure. By this, the observation that genes undergo progressive reduction in chi_values along evolution direction will reflect the progressive randomization of gene structures and the loss of the characteristics of protein coding sequences. The result proposed that during the evolution of life, genes are unexpectedly degenerating.

关键词： chi_square test gene sequence randomization evolution.

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A general phase retrieval algorithm based on a ptychographical iterative engine for coherent diffractive imaging

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Chinese Physics B 2013年第1期22卷 243-248页

作者：傅健李鹏 Research center of Digital radiation Imaging and Biomedical Imaging Beijing University of Aeronautics and Astronautics

Coherent diffractive imaging （CDI） is a lensless imaging technique and can achieve a resolution beyond the Rayleigh or Abbe limit. The ptychographical iterative engine （PIE） is a CDI phase retrieval algorithm that uses multiple diffraction patterns obtained through the scan of a localized illumination on the specimen, which has been demonstrated successfully at optical and X-ray wavelengths. In this paper, a general PIE algorithm （gPIE） is presented and demonstrated with an He-Ne laser light diffraction dataset. This algorithm not only permits the removal of the accurate model of the illumination function in PIE, but also provides improved convergence speed and retrieval quality.

关键词： phase retrieval algorithm coherent diffractive imaging ptychography

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