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Molecular basis of cryptorchidism-induced infertility

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Science china(Life sciences) 2010年第11期53卷 1274-1283页

作者： LIU YiXun & LI XiXia State Key Laboratory of Reproductive Biology, Institute of Zoology, chinese academy of sciences, beijing 100101, china 1. State Key Laboratory of Reproductive Biology Institute of Zoology Chinese Academy of Sciences Beijing 100101 China

Artificial cryptorchidism or local testicular heat treatment can induce reversible oligospermia or azoospermia in monkeys and rats via germ cell apoptosis. Local warming of monkey testes in water at 43°C for 2 consecutive days (30 min per day) decreased the number of sperm in the semen by up to 80% on d 28, and the effect was completely reversed on d 144. Germ cells rely heavily on Sertoli cells for structural and nutritional support. Specialized junctions that play a pivotal role in spermatogenesis occur at sites of Sertoli-Sertoli and Sertoli-germ cell contact in the seminiferous epithelium. We demonstrated that expression of tight junction (TJ)-associated molecules, such as occludin and zonula occludens-1 (ZO-1), were greatly reduced 24–48 h after heat treatment, while the permeability of the blood-testis barrier (BTB) was simultaneously increased, but recovered 10 d later. These results indicate a reversible disruption of the BTB associated with transient inductions of transforming growth factor (TGF) β2 and β3 expression, p38 mitogen-activated protein kinase and extracellular signal-regulated kinase activation, and concomitant loss of occludin and ZO-1. This suggests that expression of TJ-associated molecules and the BTB was reversibly perturbed by mild testicular hyperthermia, and that the heat-induced induction of TGF-β might be involved in downregulating TJ-associated proteins, leading to cell junction reduction. This review discusses the changes in total gene expression patterns after experimental cryptorchidism in adult mouse testes, and the cloning of several novel, physiologically significant spermatogenesis-specific genes.

关键词： cryptorchidism spermatogenesis apoptosis heat stress Sertoli cells blood-testis barrier tight junction

Application of asymptotic waveform approximation technique to hybrid FE/BI method for 3D scattering

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Science in china(Series F) 2007年第1期50卷 124-134页

作者： PENG Zhen1,2,3 & SHENG XinQing2 1 Institute of Electronics, chinese academy of sciences, beijing 100080, china 2 Department of Electronic Engineering, beijing Institute of Technology, beijing 100081, china 3 Graduated University of chinese academy of sciences, beijing 100039, china 1. Institute of Electronics Chinese Academy of Sciences Beijing 100080 China 2. Department of Electronic Engineering Beijing Institute of Technology Beijing 100081 China 3. Graduated University of chinese academy of sciences Beijing 100039 China

The asymptotic waveform evaluation （AWE） technique is a rational function approximation method in computational mathemetics, which is used in many appllcations in computational electromagnetlca. In this paper, the performance of the AWE technique in conjunction with hybrid finite element/boundary integral （FE/BI） method is firstly Inveetlgeted. The formuletlon of the AWE applied in hybrid FE/BI method is given in detail. The characteristic implementation of the application of the AWE to the hybrid FE/BI method is discussed. Numarlcel results demonstrate that the AWE technique can greatly speed up the hybrid FE/BI method to acquire wide-band and wide-angle backecatter radar-cross-section （RCS） by complex targets.

关键词： hybrid FE/BI AWE electromagnetic scattering RCS

Land-use development in Liaocheng prefecture of china after 1949

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Journal of Geographical sciences 1998年第4期8卷 30-47页

作者： LENG Shuying Institute of Geography, chinese academy of sciences, beijing 100101, china

s—This paper generalizes land use development in Liaocheng Prefecture, Shandong Province, china; describes land use changes during different period of time; and analyzes the driving forces of land use change.

关键词： land use development Liaocheng Prefecture

KoreainvestedenterprisesandthedevelopmentofWeihai

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Journal of Geographical sciences 1998年第2期8卷 28-38页

作者： LI WenyanInstitute of Geography, chinese academy of sciences, beijing 100101 china

with the implementation of opendoor policy of the ***, Shandong's coastal area, relying on its advantageous location and abundant resources, has become one of the most rapidly developing areas in northern china for ten years or so. In the process of the development of Weihai, Koreainvested enterprises have been playing a more and more important role. Taking Weihai as an example, this paper attempts to make a preliminary study mainly on the relationship between the Korean direct investment and the economic development in china's port cities concerned.

关键词： Koreainvested enterprises sustainable development Weihai china.

Determination　of　herbicides　atrazine　and　butachlor　in　soil　by　high　performance　liquid　chromatography

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Journal of Environmental sciences 1996年第4期8卷 504-506页

作者： Xu Weibing (Research center for Eco-Environmental sciences,chinese academy of sciences,beijing 100085,china) Res. Ctr. for Eco-Environ. sciences Chinese Academy of Sciences Beijing 100085 China

A Liquid Chromatographic procedure was described for simultaneous determination atrazine and butachlor in soil with a diode-array-detector(DAD).Unequivocal identification by Rt alone,however,is sometimes difficult. The UV spectra offer a viable alternative to *** distinct differences in Rt and UV of the peaks are noteworthy. UV spectra are extremely helpful and served to accurately identify the various component. Soil samples containing herbicide residues were extracted on a shaker using dichloromethane. The extractions were finally concentrated to 1 ml by a K-D concentrator then the residues were quantitated by peak height. Detection limits for atrazine and butachlor were 0.1 ppb and 0.8 ppb respectively. Fortified at 5.0 ng,10. 0 ng, and 50.0 ng levels,the recoveries of atrazine (n= 8)were 88.4%,95. 1% and 91. 6%. Fortified at 10. 0 ng,50. 0 ng and 80.0 ng levels,the recoveries of butachlor (n=8) were 89. 8%,91.2% and 87.4%,respectively.

关键词： RP-HPLC,atrazine butachlor herbicids soil.

Comparison of dynamic changes in endogenous hormones and sugars between abnormal and normal Castanea mollissima

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Progress in Natural Science:Materials International 2008年第6期18卷 685-690页

作者： Tao Liua,b,Yunqian Hua,*,Xiaoxian Li a aKunming Institute of Botany,chinese academy of sciences,Kunming 650204,china bGraduate University of the chinese academy of sciences,beijing 100049,china Kunming Institute of Botany Chinese Academy of Sciences Kunming 650204 China Graduate University of the chinese academy of sciences Beijing 100049 China

To elucidate the possible functions of endogenous hormones in the flowering of chestnut,concentrations of four endogenous hor-mones[indole-3-acetic acid(IAA),gibberellic acid(GA),abscisic acid(ABA),zeatin riboside(ZR))and the soluble sugars content were measured in both normal and developmentally abnormal chinese chestnut(Castanea mollissima)during flowering and fruiting *** results showed that the contents of ZR,ABA,and GA exhibited a significant dierent pattern in normal trees from that in abnormal trees,while the contents of IAA and soluble sugars showed a similar change pattern between *** results suggest that quantitative changes in endogenous hormones may correspond to dierent flowering and fruiting mechanisms.

关键词： Castanea mollissima Endogenous hormones Soluble sugars

Myotoxic activity of a Gln-49 phospholipase A2 from Agkistrodon blomhoffii ussurensis snake venom

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Progress in Natural Science:Materials International 2006年第2期16卷 178-182页

作者： BAO Yongming, BU Pengcheng, YANG Jun, YANG Wei, JIA Peilin and AN Lijia (Department of Bioscience and Biotechnology, Dalian University of Technology, Dalian 116024, china Institute of Biophysics, chinese academy of sciences, beijing 100101, china Graduate School of chinese academy of sciences, beijing 100039, china) [a]Department of Bioscience and Biotechnology Dalian University of Technology Dalian China [b]Institute of Biophysics Chinese Academy of Sciences Beijing China [c]Graduate School of chinese academy of sciences Beijing China

A novel myotoxic protein phospholipase A2(PLA2), denoted as Gln49-PLA2, has been isolated from snake venom of Agkistrodon blomhoffii ussurensis, which has weak lethal effect and apparent anticoagulant activity, but lacks the PLA2 and hemorrha-genic activity. Gln49-PLA2 obviously increases of plasma creatine-kinase (CK) upon intramuscular injection in mice, suggesting that it may induce a dose-dependent myonecrosis. Histological studies also reveal morphological changes in mouse skeletal muscles, including extensive myonecrosis, hemorrhage and neutrophil infiltration in the treated animals. The myotoxic ability induced by Gln49-PLA2 can be partially inhibited by heparin.

关键词： snake venom phospholipase A2 Agkistrodon blomhoffii ussurensis myotoxic activity.

OPTIMAL MIXED H-P FINITE ELEMENT METHODS FOR STOKES AND NON-NEWTONIAN FLOW

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Journal of Computational Mathematics 2001年第1期19卷 67-76页

作者： Ping-bing Ming Zhong-ci Shi (Institute of Computational Mathematics, chinese academy of sciences, beijing 100080, china) 中科院计算数学与工程计算数学所北京 100080

Presents an h -- p finite element methods based upon a mixed variational formulation for the three-field Stokes equations and linearized Non-Newtonian flow. Computation of the algebraic system generated from Problem H... 详细信息

关键词： mixed hp- finite element method non-Newtonian flow stabilization scaled weak B-Binequality

Constraints of authigenic carbonates on trace elements (Sr,Mg) of lacustrine ostracod shells in paleoenviron-ment reconstruction and its mechanism

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Science china Earth sciences 2008年第5期51卷 654-664页

作者： HU Guang1,2, JIN ZhangDong1 & ZHANG Fei3 1 State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, chinese academy of sciences, Xi’an 710075, china 2 Graduate University of the chinese academy of sciences, beijing 100049, china 3 College of Resources and Environmental Science, Nanjing agricultural University, Nanjing 210095, china State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China Graduate University of the chinese academy of sciences Beijing 100049 China College of Resources and Env

Molar ratios of Mg/Ca and Sr/Ca were measured in two species of ostracod shells preserved in the upper core (15–55 m) of the Hequing Basin in Yunnan Province, southwest china. By correlating the molar ratios between Mg/Ca and Sr/Ca and comparing them with Sr concentrations of the sediments, we suggested that: (1) the molar Mg/Ca and Sr/Ca ratio variations in respective ostracod primo reflected the changes in its ambient water composition and ecology; (2) the molar Sr/Ca ratios responded better to the salinity change linearly than Mg/Ca without aragonite precipitation in the system, and otherwise there was no linear relation between them; and (3) the molar Sr/Ca ratios were mainly controlled by salinity and authigenic carbonate precipitation, whereas the molar Mg/Ca ratios were related to both salinity and temperature. In fact, the rate of ostracod growth owing to temperature controls the fluctuation of Mg/Ca in shells. Here, more attentions should be paid to the constraint of authigenic mineral precipitation processes on the trace elements in ostracod shells and to the correlation between these trace elements in biogenic carbonates and compositions of the sediments in systems and in future in vitro experiments.

关键词： ostracod shell molar Sr/Ca ratio molar Mg/Ca ratio environmental response Heqing Basin