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In vitro release of 1,3-bis(2-chloroethyl)-1-nitrosourea sustained-release microspheres and the distribution in rat brain tissues

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Neural Regeneration research 2006年第9期1卷 793-796页

作者： Xia Li1, Liping Guo2, Qin Li3 1Central Pharmacy, General Hospital of Chinese People’s Armed Police Forces, Beijing 100039, china 2Department of Pharmaceutics, Zhengzhou Central Hospital, Zhengzhou 450007, Henan Province, china 3Teda International Cardiovascular Hospital, tianjin 300457, china Central Pharmacy General Hospital of Chinese People's Armed Police Forces Beijing 100039 China Department of Pharmaceutics Zhengzhou Central Hospital Zhengzhou 450007 Henan Province China Teda International Cardiovascular Hospital Tianjin 300457 China

BACKGROUND: The implantation of released chemotherapeutic drugs, which takes biodegradable polymer as vector, into the tumor site can get high concentration and release the drug for a long time, it can directly act on the tumor cells, and reduce the general toxicity. OBJECTIVE: To explore the in vitro and in vivo course of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) sustained-release from BCNU-loaded polylactide (PLA) microspheres (MS) and location in rat brain tissue. DESIGN: A repetitive measurement. SETTING:Central Pharmacy, General Hospital of Chinese People’s Armed Police Forces. MATERIALS: Thirty male SD rats were used. PLA (Mr5000, batch number: KSL8377) was produced by Wako Pure Chemical Inc.,Ltd. (Japan); BCNU (batch number: 021121) by tianjin Jinyao Amino Acid Co., Ltd.; BCNU-PLA-MS was prepared by the method of solvent evaporation and pressed into tablets (10 mg/tablet). High-performance liquid chromatography (HPLC) Agilent 1100 (USA); LS9800 liquid-scintillation radiometric apparatus (Beckman). Chromatographic conditions: Elite Hypersil ODS2 C18 chromatographic column (5 μm, 4.6 mm×150 mm); Mobile phase: methanol: water (50:50), flow rate was 1.0 mL per minute, wave length of ultraviolet detection was 237 nm, and the inlet amount of samples was 10 μL. METHODS: The experiments were carried out in the experimental animal center of the General Hospital of Chinese Armed Police from May 2004 to July 2005. ① In vitro BCNU-PLA-MS release test: BCNU-PLA-MS was prepared by the method of solvent evaporation, then placed in 0.1 mol/L phosphate buffered solution (PBS, pH 7.4, 37 ℃), part of MS were taken out at 1, 2, 3, 7, 10 and 15 days respectively, and the rest amount of BCNU in MS was determined by HPLC, then the curve of BCNU-PLA-MS release was drawn. ②In vivo BCNU-PLA-MS release and distribution test: The rats were anesthetized, then BCNU-PLA-MS were implanted to the site 1 mm inferior to the cortex of frontal lobe. Five rats were killed postoperatively at 4 h

关键词： BCNU MS PLA nitrosourea sustained-release microspheres and the distribution in rat brain tissues chloroethyl

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Constructive proof of deficiency theorem of (g,f)-factor

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Science china Mathematics 2010年第6期53卷 1657-1662页

作者： LU HongLiang1,& YU QingLin2 1center for Combinatorics,LPMC,Nankai University,tianjin 300071,china 2Department of Mathematics and Statistics,Thompson Rivers University,Kamloops V2C5N3,Canada 1. center for Combinatorics LPMC Nankai University Tianjin 300071 China2. Department of Mathematics and Statistics Thompson Rivers University Kamloops V2C5N3 Canada

Berge(1958) gave a formula for computing the deficiency of maximum matchings of a *** generally,Lov'asz obtained a deficiency formula of(g,f)-optimal graphs and consequently a criterion for the existence of(g,f)-***,Lov'asz proved that there is one of these decompositions which is "canonical" in a *** this paper,we present a short constructive proof for the defficiency formula of(g,f)-optimal graphs,and the proof implies an efficient algorithm of time complexity O(g(V)|E|) for computing the ***,this proof implies this canonical decomposition via efficient algorithms(i.e.,in polynomial time).

关键词： deficiency factor alternating trail

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Effects of temperature and pressure on the structural and optical properties of ZnO films grown by pulsed laser deposition

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Science china(Technological Sciences) 2010年第2期53卷 317-321页

作者： ZHAO Lei, XU ChangShan, LIU YuXue & LIU YiChun center for Advanced Opto-Electronic functional Materials research, Northeast Normal University, Changchun 130024, china 1. center for Advanced Opto-Electronic functional Materials research Northeast Normal University Changchun 130024 China

ZnO thin films were deposited on fused silica via pulsed laser deposition (PLD) at substrate temperatures from 300°C to 800°C and ambient oxygen pressures ranging from 10-2 mTorr to 240 mTorr. X-ray diffraction (XRD) and Raman spectra indicated that wurtzite ZnO was obtained in all cases. The highly c-oriented ZnO films were obtained for oxygen pressures above 11 mTorr. The room-temperature photoluminescence (PL) spectra demonstrated that all the films exhibited strong near-band-edge (NBE) emission, while deep-level (DL) emission was also observed in films deposited at oxygen pressures below 80 mTorr. From analysis of the XRD, Raman and photoluminescence PL data, an optimal condition was identified for the deposition of highly crystallized ZnO films.

关键词： zinc oxide film pulsed laser deposition optical properties

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Transport Process of Isopropanol Aqueous Solution by Pervaporation

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Transactions of tianjin University 2007年第4期13卷 263-269页

作者：魏峰张卫江韩莉果张雪梅 Chemical Engineering research center Tianjin University

To study the transport process of isopropanol aqueous solution by pervaporation, the transport model of isopropanol and that of water at 323 K in polyvinyl alcohol(PVA) membrane were obtained in this paper. Theoretical predictions agreed well with the experimental results. The interactional parameter between water and PVA membrane is less than that between isopropanol and PVA membrane, which shows that water is preferentially dissolved in PVA membrane. The plasticizing coefficient and diffusion coefficient at infinite dilution of water are larger than those of isopropanol, which shows that the dissolution and permeation in PVA membrane of water are greater than those of isopropanol. Both the interactional parameter between water and isopropanol in the membrane and that in feed rise with the increase of isopropanol content in feed, which shows that the larger isopropanol content is, the higher selectivity of the membrane is and the more remarkable separation effect of pervaporation is.

关键词： model permeate flux isopropanol water pervaporation

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research on the application of 4-weighted fractional Fourier transform in communication system

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Science china(Information Sciences) 2010年第6期53卷 1251-1260页

作者： MEI Lin 1, SHA XueJun 1 , RAN QinWen 2 & ZHANG NaiTong 1 1 Communication research center, Harbin Institute of Technology, Harbin 150080, china 2 Science research center, Harbin Institute of Technology, Harbin 150080, china 1. Communication research center Harbin Institute of Technology Harbin 150080 China2. Science Research Center Harbin Institute of Technology Harbin 150080 China

The paper reveals the relationship between the weighting coefficients and weighted functions via the research of coefficients matrix and based on the original definition of 4-weighted fractional Fourier transform(4-WFRFT).The multi-parameters expression of weighting coefficients are ***, the 4-WFRFT of discrete sequences is defined by introducing DFT into it, which makes it suitable for digital communication *** analyzing the properties of WFRFT, a typical scheme for modulation/demodulation is proposed, which could make the statistics properties of the real and image part on both of the time and frequency domain and the phase properties have a significant *** a variation could be controlled by the adjustment of transform *** the WFRFT of multi-parameters is implemented, it will be more difficult to intercept and capture the modulated signals than normal.

关键词： 4-weighted fractional Fourier transform modulation/demodulation scheme multi-domain cooperation

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Integrating MODFLOW and GIS technologies for assessing impacts of irrigation management and groundwater use in the Hetao Irrigation District,Yellow River basin

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Science china(Technological Sciences) 2009年第11期52卷 3257-3263页

作者： XU Xu1,2, HUANG GuanHua1,2 & QU ZhongYi3 1 center for Agriculture Water research, china Agricultural University, Beijing 100083, china 2 Chinese-Israeli International center for research and Training in Agriculture, china Agricultural University, Beijing 100083, china 3 Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot 010018, china 1. center for Agriculture Water research China Agricultural University Beijing 100083 China 2. Chinese-Israeli International center for research and Training in Agriculture China Agricultural University Beijing 100083 China 3. Water Conservancy and Civil Engineering College Inner Mongolia Agricultural University Hohhot 010018 China

Due to severe water scarcity, water resources used in agricultural sector have been reduced markedly in Hetao irrigation district. Application of water-saving practices (WSPs) is required for the sustainable agricultural development. The human activities including WSPs and increase of groundwater abstraction can lower down the groundwater table, which is helpful to the salinity control. Meanwhile, an excessively large groundwater table depth may result in negative impact on crop growth and fragile ecological environment. In this paper, the Jiefangzha irrigation system in Hetao irrigation district was selected as a typical area, a groundwater flow model based on ArcInfo Geographic Information System (GIS) was developed and implemented to quantify the effect of human activities on the groundwater system in this area. The preand post-processing of model data was performed efficiently by using the available GIS tools. The time-variant data in boundary conditions was further edited in Microsoft Excel with programs of Visual Basic for Application (VBA). The model was calibrated and validated with independent data sets. Application of the model indicated that it can well describe the effect of human activities on groundwater dynamics in Jiefangzha irrigation system.

关键词： groundwater flow modeling MODFLOW GIS water-saving practices irrigation district

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Rat CC chemokine receptor 4 is the functional homologue of human CC chemokine receptor 4 and can interact with human CCL17 and CCL22

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Chinese Science Bulletin 2010年第14期55卷 1388-1395页

作者： TIAN LinJie1,2, QI Hui1,2, XIE Yuan1,2, ZHANG YingMei1,2, ZHANG WenJuan1,2, SUN XiangYu1,2, WANG Ying1,2 & MA DaLong1,2 1 Laboratory of Medical Immunology, School of Basic Medical Science, Peking University Health Science center, Beijing 100191, china 2 Human Disease genomics center, Peking University, Beijing 100191, china Laboratory of Medical Immunology School of Basic Medical Science Peking University Health Science Center Beijing 100191 China Human Disease genomics center Peking University Beijing 100191 China

Human CCL17/TARC (hCCL17) and CCL22/MDC (hCCL22) interact with their receptor CCR4, playing pivotal roles in various Th2 cell-dominant diseases. Rat Ccl17, Ccl22 and Ccr4 share 63.4%, 65.2% and 87.5% homology at the amino acid level, respectively, compared with their human homologues. Rat Ccl22 has been demonstrated to interact with rat Ccr4. However, it is not known whether rat Ccl17 is a functional ligand for rat Ccr4 and whether rat Ccr4 can interact with hCCL17 and hCCL22. In this study, we cloned rat Ccl17 and Ccr4 cDNA from rat thymus and expressed the recombinant rat Ccl17. The binding assay indicated rat Ccl17 could saturably bind rat Ccr4, and this binding could be competitively inhibited by unlabeled rat Cc17, hCCL17 or hCCL22. Both rat and human CCL17 or CCL22 could induce the chemotactic migration and calcium mobilization in rat Ccr4-transfected cells. They could also desensitize each other’s effect on chemotaxis and calcium mobilization. Furthermore, both rat Ccl17 and hCCL17 could induce significant receptor internalization in rat Ccr4-EGFP transfected cells. These results demonstrated the conserved CCL17/CCR4 interaction in rats and the further cross-species interaction of rat Ccr4 with hCCL17 and hCCL22. Likewise, they provided the molecular basis for the investigation of physiological and pharmacological roles of CCR4, its ligands, and their antagonists in rat disease models.

关键词：趋化因子受体同源性大鼠人类基因转染细胞绿色荧光蛋白相互作用疾病模型

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Changes of photosynthetic capacity of some plant species under very high CO_2 concentrations in Biosphere 2

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Chinese Science Bulletin 1997年第10期42卷 859-864页

作者： JIANG Gaoming and LIN Guanghui1. Ecological research center, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, china 2. Biosphere 2 research and Education center, Columbia University, PO Box 689, Oracle, Arizona 85623, USA Ecological research center Institute of Botany Chinese Academy of Sciences Beijing 100093 China

THE responses of plant photosynthesis to elevated CO2 could be divided into short-term re-sponse and long-term response or *** the short-term response,photosynthesiscan be enhanced at the beginning of high CO2 treatment for most C3 carbon fixation species,but the photosynthetic rate may decrease when the plants are exposed to that high CO2 for

关键词： photosynthesis light compensation and saturation points apparent maximum quantum yield of CO2 fixation CO2 Biosphere 2.

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线性极化技术测试地热腐蚀速率的试验研究

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太阳能学报 2004年第5期25卷 699-702页

作者：朱家玲董海虹孟宪级天津大学地热研究培训中心天津300072

线性极化技术基本理论是根据线性极化方程式及腐蚀电化学理论,对于双电子反应,Tafel常数ba、bc可选取0 059V。通过现场测定,获得ΔE ΔI曲线,在求出Rp和ic的基础上,根据法拉弟定律,计算腐蚀速度Vc。能否在地热采暖系统中采用线性极化技... 详细信息

线性极化技术基本理论是根据线性极化方程式及腐蚀电化学理论,对于双电子反应,Tafel常数ba、bc可选取0 059V。通过现场测定,获得ΔE ΔI曲线,在求出Rp和ic的基础上,根据法拉弟定律,计算腐蚀速度Vc。能否在地热采暖系统中采用线性极化技术,关键要看所得出的Rp图是否符合或近似于线性。在国内地热采暖系统中,首次实现瞬时腐蚀速度的监测,同时也是首次将线性极化技术应用于地热现场的腐蚀研究。

关键词：线性极化极化阻力地热腐蚀速率

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Study on Storage Facilities of Agricultural Products in Courtyard in china

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Agricultural Sciences in china 2002年第7期1卷 805-810页

作者： CHEN Li, LI Xi-Hong, XIA Qiu-Yu, HU Yun-feng and GUAN Wen-qiang( National Engineering and Technology research center for Agricultural Products Freshness Portection , tianjin 300112 tianjin Commune of Science and Technology, tianjin 300003 , P. R . china ) National Engineering and Technology research center for Agricultural Products Freshness Portection Tianjin 300112 tianjin Commune of Science and Technology Tianjin 300003 P. R. China

Mini storage facilities applicable in rural areas in china have been developed after nine years of research. Optimal design of structure and refrigeration system, facilities optimization, computer control and manageme... 详细信息

关键词： Farm products Storage Mini cold storage room Refrigerator

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