大蹼铃蟾(Bombina maxima)皮肤新型血小板活性蛋白及信号转导的研究

通过对两栖类动物大蹼铃蟾（B朋b了na勿日对朋）皮肤分泌物及匀浆物的分离，纯化，从其碱性组分中得到了全新的三叶因子多肤（BIn－－TFFZ）和膜联蛋白H相关蛋白（BAIIRP），它们分别具有诱导或抑制人血小板活化的全新功能。以血小板膜糖蛋白GPVI受体激动剂stejnulxin为对照，研究了Bm一TFFZ活化人血小板的信号传导途径。哺乳动物的三叶因子（TFF）蛋白的主要功能在于通过修复粘膜损伤，维持粘膜层的完整。它们在肿瘤抑制及癌症侵润方面也有一定程度的作用。我们从两栖类动物大蹼铃蟾皮肤分泌物分离，纯化而得到了一个全新的三叶因子多肤（Bm一TFFZ）。它是单亚基蛋白，表观分子量为13000，并具有全新的诱导人血小板活化的功能，我们研究了其诱导人血小板活化的活性的量效关系。它对血小板的激活涉及血小板整合素a：Ibp3的活化，Bm一TFFZ可诱导经阿斯匹林及三磷酸腺昔"双磷酸酶（Apyrase）处理的血小板的聚集，表明B，TFFZ的活性不依赖于血小板的ADP及血栓嗯烷A2（TXAZ）的自泌正反馈。F工TC标记的B爪一TFFZ蛋白能与血小板膜结合。通过专一性药理学抑制剂的研究，我们初步排除了Bm一TFFZ蛋白作用于血小板膜已知的G一蛋白偶联受体（如ADP，TXAZ及血小板活化因子受体）的可能性。以血小板GPVI激动剂stejnulxin为对照，我们仔细研究了Bm一TFFZ蛋白刺激血小板后的信号传导分子事件，发现其酪氨酸磷酸化图谱明显不同于血小板GPVI激动剂5tejnu1X如，尤其是磷脂酶CYZ并不磷酸化。因此，我们认为Bm一TFFZ蛋白激活血小板的信号传导通路是活化磷脂酶C，并刺激胞内钙离子的释放，活化血小板伪：。p3，进而导致血小板的聚集。从Bm－－TFFZ蛋白的cDNA克隆序列推知它由104个氨基酸组成，含有两个三叶因子结构域，与人TFFZ和非洲爪蟾xPZ序列中相同的氨基酸分别占28％及34％。为了确定两栖类的三叶因子蛋白具有诱导人血小板活化的功能，我们仔细地研究了整个分离纯化过程中所有组份的血小板聚集活性并比较了它们的相对活性差异。Bm一TFFZ是第一个来自两栖类动物的血小板激动剂，也是我们第一个报道的具有诱导血小板聚集活性的三叶因子多肤。·我们还通过阴离子交换，凝胶过滤和阳离子交换层析，从大蹼铃蟾皮肤匀浆物中纯化了一个表观分子量为33kD。的单链蛋白。N一末端序列比较分析显示，该·蛋白与来自非洲爪蟾、红色原鸡和人膜联蛋白H的N一末端序列相同的氨基酸分别占70％、64％和56％。该蛋白具有以钙依赖的方式抑制专一性血小板膜糖蛋白VI（GPVI）受体激动剂-Stejnu1Xin诱导洗涤人血小板聚集的生物学功能，最大抑制率达48％。结合其N一末端序列搜索结果及其活性的钙依赖性，推测该蛋白是与膜联蛋白H相关的一类蛋白质。

四川和云南汉族长寿老人长寿机理研究

随着社会的发展，人均寿命的延长，人口老龄化已经成为我国不可回避的社会 问题。老年人在医疗卫生保健方面的花费远远超过普通人群。健康长寿老人能避 免或者延缓年龄相关疾病的发生，从而减少在卫生保健方面的花费；另外，长寿 老人的子女在年龄相关疾病方面的患病率也显著低于年龄相匹配的对照组。因 此，开展健康长寿方面的研究，一方面可以提高老年人的生活质量，另一方面可 以改善由于人口老龄化而引起的社会问题。 我国长寿老人大多零散分布在乡区，并且由于长寿老人的身体条件等原因， 给完整的收集相关数据带来困难。国内关于长寿的研究主要集中在城镇，而且由 于人群、地域、生活方式等差异我们也不能完全借鉴国外的研究成果。因此,我 们对四川和云南汉族健康长寿老人进行横断面研究,并对其长寿机理进行探索。 从亲缘关系上我们把样品分为：长寿组、血缘组和无血缘组三个组；从年龄上分 为：≤59、60-89、90-94 和≥95 四个组。在实验中，我们测定了常规体检指标， 常见促炎细胞因子和抗炎细胞因子水平以及其调控区的单核苷酸多态性。 一般认为随着年龄增加血糖水平升高，并且高水平的 HDL-C 和高比率的 HDL-C/TC 以及低TC,TG 和LDL-C 水平有利于长寿。都江堰长寿老人血糖水平偏 低，显著低于血缘组和无血缘组以及其他年龄组；调整年龄后，都江堰≥95 岁 年龄组的血糖水平显著高于90-94 年龄组；血糖水平在性别间不存在显著差异。 都江堰长寿老人LDL-C 水平在90-94 和≥95 年龄组显著低于其他年龄组，≥95 年龄组显著低于90-94 年龄组；调整性别后，90-94 年龄组女性的LDL-C 水平显 著高于男性水平，其他年龄组在性别间差异不显著；女性≥95 年龄组显著低于 90-94 年龄组，但在男性中差异不显著。TG 和TC 水平在都江堰和红塔两地各组 中的变化趋势都存在着差异，在性别间比较发现两地各年龄组变化趋势都一致， 仅在90-94 年龄组女性都显著高于男性。HDL-C 水平和HDL-C/TC 在都江堰和红 塔两地各组中变化趋势不一致，调整性别后HDL-C/TC 在90-94 年龄组两地女性 的比率都显著大于男性。通常IL6、IL10 和TNFα 水平随着年龄增加而升高。云 南长寿老人的IL6 水平显著高于血缘组和无血缘组，性别之间的差异不显著。 IL10 水平长寿组显著高于无血缘组，TNFα 水平在各组间差异不显著，由于这两 种细胞因子在绝大多数个体中呈本底水平表达，很难分析年龄与它们水平的相关性。在这三种细胞因子调控区的常见SNPs 位点上，许多研究表明il10-1082 和 il6-174 位点和长寿存在着一定的相关性，tnfα-308 位点与长寿不存在相关性。 在我们收集的样品中il6-174 位点不存在多态性。男性个体的il10-592A 和-819T 的等位基因频率在长寿组显著高于无血缘组，在-1082 位点与长寿不存在相关性。 tnfα-238A 和-308A 等位基因频率在长寿组中显著高于无血缘组，在各组单倍型 间的差异显著，G-G 单倍型在长寿组中呈下降趋势；调整性别后，两位点的等位 基因频率在各组间的差异不显著，但单倍型在各组间差异显著，变化趋势同调整 性别前一致。 总之，四川都江堰长寿人群的血糖水平和LDL-C 水平比较低，都江堰和云南 红塔两地长寿老人的血脂水平存在着地域差异。与前人的研究结果比较,汉族人 群的IL6、IL10 和TNFα水平以及常见的启动区SNPs 位点可能存在人种差异。

BAND-STRUCTURE OF MG1-XZNXSYSE1-Y

The empirical pseudopotential method within the virtual crystal approximation is used to calculate the band structure of Mg1-xZnySySe1-y, which has recently been proved to be a potential semiconductor material for optoelectronic device applications in the blue spectral region. It is shown that MgZnSSe can be a direct or an indirect semiconductor depending on the alloy composition. Electron and hole effective masses are calculated for different compositions. Polynomial approximations are obtained for both the energy gap and the effective mass as functions of alloy composition at the GAMMA valley. This information will be useful for the future design of blue wavelength optoelectronic devices as well as for assessment of their properties.

Valence hole subbands and optical gain spectra of GaN/Ga1-xAlxN strained quantum wells

The valence hole subbands, TE and TM mode optical gains, transparency carrier density, and radiative current density of the zinc-blende GaN/Ga0.85Al0.15N strained quantum well (100 Angstrom well width) have been investigated using a 6 X 6 Hamiltonian model including the heavy hole, Light hole, and spin-orbit split-off bands. At the k = 0 point, it is found that the light hole strongly couples with the spin-orbit split-off hole, resulting in the so+lh hybrid states. The heavy hole does not couple with the light hole and the spin-orbit split-off hole. Optical transitions between the valence subbands and the conduction subbands obey the Delta n=0 selection rule. At the k not equal 0 points, there is strong band mixing among the heavy hole, light hole, and spin-orbit split-off hole. The optical transitions do not obey the Delta n=0 selection rule. The compressive strain in the GaN well region increases the energy separation between the so1+lh1 energy level and the hh1 energy level. Consequently, the compressive strain enhances the TE mode optical gain, and strongly depresses the TM mode optical gain. Even when the carrier density is as large as 10(19) cm(-3), there is no positive TM mode optical gain. The TE mode optical gain spectrum has a peak at around 3.26 eV. The transparency carrier density is 6.5 X 10(18) cm(-3), which is larger than that of GaAs quantum well. The compressive strain overall reduces the transparency carrier density. The J(rad) is 0.53 kA/cm(2) for the zero optical gain. The results obtained in this work will be useful in designing quantum well GaN laser diodes and detectors. (C) 1996 American Institute of Physics.

Electronic structures of the zinc-blende GaN/Ga1-xAlxN compressively strained superlattices and quantum wells

The electronic structures of the zinc-blende GaN/Ga0.85Al0.15N compressively strained superlattices and quantum wells are investigated using a 6 x 6 Hamiltonian model (including the heavy hole, light hole and spin-orbit splitting band). The energy bands, wavefunctions and optical transition matrix elements are calculated. It is found that the light hole couples with the spin-orbit splitting state even at the k=0 point, resulting in the hybrid states. The heavy hole remains a pure heavy hole state at k=0. The optical transitions from the hybrid valence states to the conduction states are determined by the transitions of the light hole and spin-orbit splitting states to the conduction states. The transitions from the heavy hole, light hole and spin-orbit splitting states to the conduction states obey the selection rule Delta n=0. The band structures obtained in this work will be valuable in designing GaN/GaAlN based optoelectronic devices. (C) 1996 Academic Press Limited

Optical gain in zinc-blende GaN/Ga1-xAlxN strained quantum well laser

Based on the valence subbands of the zinc-blende GaN/Ga0.85Al0.15N strained quantum wells obtained by a 6x6 Hamiltonian (including heavy hole, light hole and spin-orbit splitting band), optical gain and radiative current density are calculated for the strained quantum well laser structures. The compressive strain in the GaN well region strongly depresses the TM mode optical gain and enhances the TE mode optical gain.

Electronic properties of zinc-blende GaN, AlN, and their alloys Ga1-xAlxN

The electronic properties of wide-energy gap zinc-blende structure GaN, A1N, and their alloys Ga(1-x)A1(x)N are investigated using the empirical pseudopotential method. Electron and hole effective mass parameters, hydrostatic and shear deformation potential constants of the valence band at Gamma and those of the conduction band at Gamma and X are obtained for GaN and AIN, respectively. The energies of Gamma, X, L conduction valleys of Ga(1-x)A1(x)N alloy versus Al fraction x are also calculated. The information will be useful for the design of lattice mismatched heterostructure optoelectronic devices based on these materials in the blue light range application. (C) 1995 American Institute of Physics.

Band structure parameters of zinc-blende GaN, AlN and their alloys Ga1-xAlxN

The electronic properties of wide energy gap zinc-blende structure GaN, AlN and their alloys Ga1-xAlxN are investigated using the empirical pseudopotential method. Electron and hole Effective mass parameters, hydrostatic and shear deformation potential constants of the valence band at Gamma and those of the conduction band at Gamma and X are obtained. The energies of Gamma, X, L conduction valleys of Ga1-xAlxN alloy versus Al fraction x are also calculated. The information will be useful for the design of lattice mismatched heterostructure optoelectronic devices in the blue light range.

第一性原理研究Mg,Si和Mn共掺GaN

采用基于密度泛函理论(DFT)的第一性原理平面波赝势法(PWP)计算Mg,Si和Mn共掺GaN电子结构和光学性质,分析比较计算结果.计算表明:掺杂后体系均在能隙深处产生自旋极化杂质带,具有半金属性,能产生自旋注入.与Mn掺杂GaN比较,Mg共掺后能使居里温度(TC)升高,并在1.0eV出现源于Mn4+离子基态4T1(F)到4T2(F)态跃迁的较强的光吸收,而Mn掺杂GaN时位于1.3eV处的吸收峰消失;Si共掺后没能使TC升高,且在低能区无光吸收现象.

青杨(Populus cathayana Rehd.)雌雄植株对干旱胁迫的生理生态响应差异

随着全球气候变暖和温室效应加剧，干旱和荒漠化成为威胁人类生存和发展的主要 灾害，许多被子植物对干旱胁迫的生理、生态和生化响应已逐步得以报道，但很少有开 展干旱胁迫对雌雄异株植物的影响方面的研究。由于这类植物在长期进化过程中已经在 生长、性比、生殖格局、空间分布、资源配置和生物量分配等方面形成了明显的性别差 异，因此，干旱胁迫必将对其雌雄植株产生不同的生理生态影响。本研究以青杨为模式 植物，采用植物生态、生理及生物化学等研究方法，系统研究青杨雌雄植株在常温、增 温以及喷施外源脱落酸的条件下对干旱胁迫的响应，揭示其在生长形态、生物量分配、 光合作用、用水效率和生理生化等方面的性别间差异。主要研究结果如下： 1. 青杨雌雄植株对干旱胁迫的综合响应。 与较好水分条件相比，干旱胁迫显著降低了青杨雌雄植株的光合作用和生长发育， 影响了许多生理生化过程，并导致雌雄植株在生长发育、气体交换、用水效率、膜脂抗 氧化和抗氧化系统酶活性方面表现出显著的性别间差异。在较好水分条件下，雌雄植株 之间在株高、基径、生物量、净光合速率、蒸腾速率、用水效率以及丙二醛、脱落酸和 游离脯氨酸等生化物质含量方面均无显著差异。但在干旱胁迫下，雄株在生长发育、气 体交换、水分利用效率、膜脂过氧化保护和抗氧化系统酶活性方面均显著高于雌株，表 现出比雌株更高的株高、基径、叶面积、总叶片数、总生物量、总色素含量、类胡萝卜 素含量、净光合速率、蒸腾速率、羧化效率、光系统II最大光化学效率、内在水分利用 效率、碳同位素组分、过氧化氢酶和过氧化物酶活性等，而在CO2补偿点、比叶面积、 叶绿素a/b、丙二醛、脱落酸和超氧化物歧化酶活性等指标上显著低于雌株。与雌株相比， 雄株表现出更高的干旱胁迫适应能力，而雌株的生长发育和生理生化过程更易遭受干旱 胁迫的影响。 2. 干旱胁迫下的青杨雌雄植株对增温处理的综合响应 与环境温度相比，增温在干旱胁迫前后均显著促进了雌雄植株的生长发育、气体交 换，降低水分利用效率，影响生化物质含量，并促使青杨雌雄植株之间在干旱胁迫下表 现出显著的差异。在较好水分条件下，增温导致雌株的株高、基径、叶面积、总叶片数、 总生物量和超氧化物歧化酶活性显著高于雄株，而用水效率、丙二醛、脱落酸和游离脯 氨酸、抗坏血酸过氧化物酶和过氧化物酶活性低于雄株。在干旱胁迫下，增温将导致雄 株的株高、基径、叶面积、总生物量、净光合速率、蒸腾速率、气孔导度、总色素含量、 相对含水量、过氧化氢酶和抗坏血酸过氧化物酶活性等显著高于雌株，而光系统II 最大 光化学效率、内在水分利用效率、碳同位素组分、丙二醛、脱落酸、游离脯氨酸和超氧 化物歧化酶活性显著低于雌株。与雄株相比，水分较好条件下的增温有利于促进雌株的 生长发育，并在生理生态特征上优于雄株。而干旱胁迫下的增温则加剧了水分胁迫强度， 致使雌株的生长发育遭受比雄株更多的负面影响。 3. 干旱胁迫下的青杨雌雄植株对喷施外源脱落酸处理的综合响应 与对照相比，在干旱胁迫下喷施外源脱落酸可显著增加青杨雌雄植株的生长发育、 气体交换、降低水分利用效率，影响了生化物质含量，并导致青杨雌雄植株之间在干旱 胁迫下表现出显著的生理生态差异。在干旱胁迫下，喷施外源脱落酸致使雌株的株高、 叶面积、叶干重、细根干重、总生物量、净光合速率、蒸腾速率、气孔导度、光系统II 最大光化学效率、非光化学淬灭系数、相对含水量、总光合色素、类胡萝卜素、脱落酸、 超氧化物歧化酶和过氧化物酶活性的增加量显著高于雄株，而根重比、根冠比、细根/ 总根、比叶面积、内在水分利用效率、碳同位素组分、丙二醛、脯氨酸、过氧化氢酶和 抗坏血酸过氧化物酶活性等指标的减少量上显著低于雄株。与对照相比，干旱胁迫下的 喷施外源脱落酸则一定程度能减缓植株遭受胁迫的压力，促进植株生长和气体交换，减 少了植株体内的过剩自由基数量，并促使雌株的生长发育和光合能力显著提高，增强其 抗干旱胁迫能力。 With development of global warming and greenhouse effect, drought and desertification have been became main natural disasteres in resent years. Studies on ecophysiological responses of most angiosperm species to environmental stress have been reported, but little is known about dioecious plant responses to drought stress. Since significant differences on growth, survival, reproductive patterns, spatial distribution, as well as resource allocation between males and females of dioecious plant have been formed during evolutionary process, sexual different ecophysiological responses should be caused by drought stress. In this experiment, Populus cathayana Rehd. was used as model plant to study the sex-related responses to drought by using the ecological, physiological and biochemical methods under normal atmospheric temperature, elevated temperatures and exogenous abscisic acid (ABA) application treatment respectively, and to expose the sexual differences in growth, biomass allocation, photosynthesis, water use efficiency and some biochemical material contents in the males and females of dioecious plant. The results are follows: 1. A large set of parallel responses of males and females of P. cathayana to drought stress Compared with well-watered treatment, drought significantly decreased growth and photosynthesis of P. cathayana individuals, affected some physiological and biochemical processes, and induced males and females to exhibit obvious sexual differences in growth, gas exchange, water use efficiency, lipid peroxidation protection and antioxidant defenses enzyme system. Under well-watered treatment, there were no significant sexual differences in height growth (HG), basal diameter (BD), dry matter accumulation (DMA), net photosynthesis rate (A), transpiration (E), water use efficiency (WUE), and malondialdehyde (MDA), abscisic acid (ABA) and praline (Pro). However, under drought stress, males were found to exhibit higher HG, BD, leaf area (LA), total leaf number (TLA), DMA, total chlorophyll contents (TC), carotenoids content (Caro), A, E, carboxylation efficiency (CE), the maximum efficiency of PSII (Fv/Fm), intrinsic water use efficiency (WUE ), carbon isotope composition (δ13C), catalase (CAT), peroxidase (POD) and lower CO2 compensation point (Γ), specific leaf area (SLA), chlorophyll a/b ratio (Chla/Chlb), MDA, ABA and superoxide dismutase (SOD) than females. The results suggest that males possess greater drought resistance than do females and females suffer more negative effect on growth and development, physiological and biochemical processes than males under drought stress. 2. A large set of parallel responses of drought-stressed males and females of P. cathayana to elevated temperatures Compared with environmental temperature, elevated temperature treatment significant increased growth and gas exchange, decreased water use efficiency, changed some biochemical material contents of P. cathayana individuals, and induced males and females to exhibit obvious differences under drought stress. Under good water condition, elevated temperature treatment caused females to show significant higher HG, BD, LA, TLN, DMA, SOD activity, and great lower WUE, MDA, ABA, Pro, ascorbate peroxidase (APX) and POD than do males. On contrary, under drought condition, elevated temperature treatment induced males to exhibit higher HG, BD, LA, DMA, A, E, stomatal conductance (gs), relative water content (RWC), CAT, APX activity but lower Fv/Fm, WUE, δ13C, MDA, ABA, Pro, SOD activity than do females. The results suggest that females will benefit from elevating temperature under good water condition by possessing better ecophysiological processes than that of males, but will suffer from greater negative effects than do males when grown under drought stress with elevated temperature treatment. 3. A large set of parallel responses of drought-stressed males and females of P. cathayana to exogenous ABA application Compared with controls, exogenous ABA application under drought greatly increased growth and gas exchange, decreased water use efficiency, changed some biochemical material contents in P. cathayana individuals, and induced males and females to exhibit obvious sexual differences under drought. Under drought stress, exogenous ABA application induced females to exhibit more increases in HG, LA, leaf weight (LW), fine root weight (FRW), DMA, A, E, g, Fv/Fm, non-photochemical quenching coefficient (qN), RWC, TC, Caro, ABA, SOD, POD s activity than males, but to show lower decreases in root/weight ratio (RWR), root mass/foliage area ratio (RF), fine root/total root ratio (FT), SLA, WUE, δ13C, MDA, Pro, CAT, APX than males. The results suggest that exogenous ABA application under drought stress will eliminate negative damages caused by drought stress at a certain extent，promote the growth and gas exchange of plant and decrease the number of superfluous 1O2 in plant cells of males and females of P. cathayana. Furthermore, exogenous ABA application promoted more drought resistance in females than in males by increasing more growth and photosynthetic capacity in females under drought stress.

利用多重示踪技术研究正常鼠和肿瘤鼠的微量元素代谢(英文)

利用25 MeV/u40Ar +Se中能重离子核反应,制备包含24种元素在内的多重示踪剂,通过对元素γ谱的分析,研究了正常鼠和肿瘤鼠体内微量元素的分布及代谢。Mg,Sr, Ga, As,Sc, V, Cr, Mo, Co,Fe, Y,Zr, Nb和Ru等元素在肿瘤鼠的粪便和尿液中的排泄时间与正常鼠不同。肿瘤鼠与正常鼠相比,Na, Mn,Fe和Co的排泄变化较大,肿瘤鼠的排泄率较正常鼠高;而Ca, Y,Zr和Mo的排泄率肿瘤鼠则较正常鼠低;在正常鼠脏器、组织和血液样品中测出了Na,Rb,Ga,Sc, As,Zn, V,Cr, Mn,Co,Fe、Y,Zr, Tc, Ru, Ag和In等17种元素,肿瘤鼠检测出了除Zn和As之外的其它15种元素。几乎所有的元素在正常鼠中的吸收均比肿瘤鼠高。大部分元素分布在肝、肾和毛皮以及实体瘤中,而Fe和Na在肿瘤组织则没有检测到。

中能重离子碰撞中的气-液相变和同位旋分馏

利用核物质理论研究气 -液相变结果表明 ,气 -液相变中临界温度Tc 随系统质量的增加而增加 ,但随碰撞系统同位旋的增加而减小 .利用改进的同位旋相关的量子分子动力学模型 ,研究了中能重离子碰撞过程中同位旋分馏强度随碰撞系统的同位旋和系统质量的变化 ,结果表明 ,同位旋分馏强度与气 -液相变临界温度Tc 有对应的关系 ,特别是气 -液相变和同位旋分馏都发生在正常核密度以下低密度的spinodal不稳定区 .这表明气 -液相变和同位旋分馏具有相类似的动力学行为和内在联系 ,也预示着可以通过对同位旋分馏强度的研究和测量来揭示中能重离子碰撞过程中气 -液相变的动力学特征

A pilot experiment for mass measurement at CSRe

A pilot experiment of mass measurement was performed at CSRe with the method of isochronous mass spectrometry. The secondary fragments produced via RIBLL2 with the primary beam of 400 MeV/u, Ar-36 delivered by CSRm were injected into CSRe. The revolution periods of the stored ions, which depend on the mass-to-charge ratios of the stored ions, were measured with a time-of-flight detector system. The results show that the mass resolution around 8 x 10(-6) for Delta m/m is achieved.

丰中子奇异核17B的实验研究

在兰州重离子加速器国家实验室(HIRFL)放射性次级束流线(RIBLL)上，用束流透射法测量了丰中子奇异核17B与C靶反应的总截面.假定17B具有15B(核芯)＋2n结构，采用Gauss＋HO形式的密度分布和零力程Glauber模型进行计算的结果可以很好地拟合实验数据，并得出17B的密度分布有一个很大的弥散，表明17B是双中子晕核.