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。

一种新型的5GHz自适应偏置及可变增益低噪声放大器

该文提出了一种新型的自适应偏置及可变增益低噪声放大器（LNA），利用电荷泵（亦称电压倍增器）将LNA输出信号转换成与LNA射频输入信号功率成比例变化的直流信号，以此信号同时反馈控制LNA的偏置和增益，来实现自适应偏置以及可变增益低噪声放大器。从而极大地改善了LNA的输入线性范围。鉴于5GHz频率下，Bipolar相对于CMOS更好的频率特性和低噪声特性，该项研究采用了BiCMOS工艺，实现了低于3．0dB的噪声系数（高增益状态下）和大约13dBm的输入三阶交调点ⅡP3的控制范围以及大于15dB的增益控制范围。

Properties of the rotational bands in the transitional nucleus 189Pt

High-spin states in 189Pt have been studied experimentally using the 176Yb(18O,5n) reaction at beam energies of 88 and 95 MeV. The level scheme of189Pt has been revised significantly and extended to high-spin states.Rotational bands have been analyzed in the framework of triaxial particle-rotor model, and a γ ≈−30◦triaxial shape and a near-prolate shape have been proposed to the νi−113/2 and νf5/2(p3/2) bands, respectively. Two ΔI = 2 transition sequences with similar energies have been observed, and they have been proposed to be associated with the νi−213/2νf5/2(p3/2) configuration. The structure built on the νi−213/2νf5/2(p3/2) configuration could be interpreted theoretical calculations of the triaxial particle-rotor model if a near-oblate shape is assumed.

~(166)Ta高自旋态及A～160区S IG NATURE反转的研究

本论文以A～160区奇奇核的高自旋态核结构为研究对象，详细地总结分析了该区奇奇核[h11/2]p[i13/2]n带的性质，利用在束核谱学实验手段布居和测量了166Ta核高自旋态能级结构、借助模型理论对该核实验结果进行分析，还从理论方面系统地研究了A～160区奇奇核[h11/2]p[i13/2]n带的signature反转现象与形变的关系，取得了一些创新成果。 奇奇核高j组态带的signature反转现象系统地存在于A～160、A～130和A～80核区，目前理论上提出的各种可能机制还不能彻底解释清楚这一现象。本文中较详细地归纳了A～160区奇奇核signature反转带，即[h11/2]p[i13/2]n带，实验数据的一些系统学规律，具体贡献在于 1、总结了晕态[h11/2]p[i13/2]n带的跃迁能量系统学规律，指出存在这种规律的原因在于形变和价核子耦合性质随质子数和中子数增减的有规律变化。 2、展示了随质子数增大和中子数减小该带准粒子顺排角动量相加性逐渐变差的现象，指出这种变差的原因可能是形变减小导致剩余n-p相互作用的增强，以及奇奇核带和与之相比较的奇核带形变差异增大。文中强调了使用顺排角动量相加性规则时要考查相加前后两个signature分支顺排角动量的相对大小。跃迁能量系统学规律和顺排角动量相加性规则是目前指定该区奇奇核[h11/2]p[i13/2]n带核态自旋值的有效工具，上述工作有益于研究新核时正确运用这些工具。文中其它归纳和总结工作也为后续研究提供了较为系统的参考资料。 此前尚未有人对166Ta核做过在束研究，我们在中国原子能科学研究院利用HI-13串列加速器通过141Pr（28Si，3n）反应布居和测量了166Ta核高自旋态。实验中使用了5片厚500μg/cm2纯度98.0%的141Pr自衬靶，7台HpGe反康谱仪和1台平面型HpGe探测器。用改变束流能量测量在束单谱和剩余放射性的方法确认实验中生成了166Ta核并为符合实验选定了束流能量。γ-γ符合实验束流能量为127MeV，实验中共收集到约50×106个两重符合事件。实验后用152Eu放射源对探测系统进行了能量和效率刻度。符合实验数据被反演成γ-γ、X-γ和DCO二维谱。通过处理和分析实验数据，得到以下主要结果： 1、用TaKX射线开窗、比较不同束流能量下的在束单谱和排除已知核射线等方法确认了属于166Ta的射线，根据这些射线的级联关系首次建立起了166Ta核的在束能级纲图，其中包括4条转动带，60条射线。166Ta核的晕带是一条耦合性较强的带，建立起的该带能级纲图中包括16条能级和29条射线，每一signature分支有7条E2拉伸跃迁。另外三条带是两条耦合带和一条双退耦带。其中一条耦合带的耦合性较强、位置较高，可能是4准粒子带。 2、计算γ-γ符合矩阵和DCO矩阵开窗谱中峰下面积，得到了166Ta核55条射线在实验中的相对强度Iγ、29条射线的方向关联系数Iγ（35°）/Iγ（75°）和21个核态退激过程的跃迁强度分支比λ等数据。 3、借助模型计算，为实验中发现的4条转动带指定了组态。晕核组态定为9/2[514]p3/2[651]n, Kπ值为6-。另外两条耦合带的组态被定为9/2[514]p3/2[521]n和9/2[514]p3/2[521]n{3/2[651]n}2,退偶带的组态可能是1/2[514]p3/2[651]n。 4、通过分析跃迁能量系统学规律和运用顺排角动量相加性规则指定了166Ta核晕带核态的自旋值，还使用其它方法倾向性地指定了另外三条带的自旋值。 5、提取了一些核态退激过程B（M1）/B（E2）理论值比实验值偏大，指示该带可能存在负γ形变。另外两条耦合带的B（M1）/B（E2）计算值与实验值比较接近，这方面支持我们对其组态的指定。回弯之前的166Ta核晕带B（M1）/B（E2）值与已知的同位素和同中子素奇奇核晕带值相比大许多，我们认为这是组态和形变变化造成的。 6、166Ta和邻核晕带集体转动惯量随转动角频率平方的变化关系显示准质子占据h11/2子壳顶部轨道时顺排发生得较晚，准中子占据i13/2子壳低部轨道时顺排发生得较早。 7、实验结果显示166Ta核的晕带出现signature反转，signature反转点自旋值和反转点之下M1跃迁摆动幅度都与全区规律相符。 我们研究166Ta核的高自旋态能级结构旨在为研究奇奇核signature反转提供新的实验数据，实验研究达到了预期的目的，实验结果证实了在轻Ta奇奇核同位素中也系统地存在signature反转。 在讨论A～160区奇奇核[h11/2]p[i13/2]n带的signature反转机制方面，作者首次利用现有的TRS计算方法系统地考察了该区32个奇奇核该带形变极其随核子数增减的变化趋势，进而通过CSM计算考察了形变对该带signature劈裂的影响。这方面的研究成果主要包括： 1、计算结果显示，该区核芯较容易在γ形变方向受到价核子的形状极化作用，89≤Z≤95时i13/2准中子一般具有正γ形变驱动作用且随着中子数减小此正γ形变驱动作用逐渐增强，67≤Z≤75时h11/2准质子一般具有负γ形变驱动作用且随着质子数增大此负γ形变驱动作用逐渐增强，Z=63和65时h11/2准质子两个signature组态具有不同方向的γ形变驱动作用，总体看h11/2准质子的γ形变驱动作用没有i13/2准中子的强。 2、只考虑ε2和γ形变参量的TSR计算结果显示A～160区中N=89和91奇奇核的[h11/2]p[i13/2]n带有较大的正γ形变，N≥93奇奇核中该带γ形变则较小或为负γ形变。计算出的不同核该带的γ形变值随中子数增加逐渐减小、随质子数变化的规律较复杂且变化幅度没有随中子数变化时那么明显，Z≤67时一些核两signature的形变还有明显的差异。 3、CSM计算表明正γ形变可以导致费米面附近的h11/2准质子轨道signature反转，并且存在正γ形变时ε2形变、ε4形变、质子对力和质子数的不同都对signature反转幅度和反转点对应的角频率都有影响，[h11/2]p[i13/2]n带两个signature组态形变的不同对费米面附近i13/2准中子轨道的位置也有影响。 4、利用从TRS计算出的形变参量所做CSM计算显示，该区部分奇奇核[h11/2]p[i13/2]n带出现signature反转。计算出的signature反转随中子数或质子数变化趋势有些和实验结果相符，也有一些与实验结果不符，对有些实验上发现signature反转的核还计算不出反转。计算结果预言该区一些没有实验数据的奇奇核[h11/2]p[i13/2]n带中也会存在signature反转，这些核是154Eu、162Ta、164Ta和168Re等。 此前对解释A～160区奇奇核signature反转的系统规律时是否必须考虑γ形变还没有定论，本文工作证实了较明显的正γ形变对signature反转起着重要的作用。但是，单纯考虑γ形变并不能完全再现A～160区奇奇核signature反转规律，今后的研究工作还要系统而细致地考虑各方面因素。

1987年特大火灾后不同树种种植比例对大兴安岭森林景观的长期影响

应用空间直观景观模型(LANDIS)模拟了1987年大兴安岭北坡图强林业局特大森林火灾后在目前种植强度下,不同落叶松和樟子松种植比例(100%落叶松(P1)、70%落叶松和30%樟子松(P2)、50%落叶松和50%樟子松(P3)、30%落叶松和70%樟子松(P4)、100%樟子松(P5))以及完全依靠天然更新(P0)条件下森林景观的长期动态变化.结果表明,在演替的前期、中期和后期,不同种植比例均对落叶松、樟子松和白桦有显著影响;落叶松所占的面积百分比随时间的推移均呈上升趋势,而樟子松则相反;在各种植预案下,落叶松和樟子松的面积百分比均高于天然更新预案的比例,随着落叶松种植比例的增加,落叶松的多度也相应增加;樟子松在该区所占的面积百分比也随其种植比例的增大而增加.白桦在天然更新预案下所占的面积百分比明显高于种植预案下所占的比例;而不同落叶松和樟子松种植比例也对白桦面积有较大影响,樟子松种植的比例越大,白桦所占的面积百分比越高,说明落叶松比樟子松有更强的竞争能力.但P2、P3和P4预案下,落叶松和樟子松的面积所占比例相差不大,但要高于完全种植落叶松(P1)或樟子松(P)所占的比例.

保护性耕作对土壤线虫c-p类群及功能团的影响

以辽宁彰武县保护性耕作示范推广基地土壤为研究对象,通过实地调查和取样分析,对比研究了传统犁耕和6a保护性耕作(免耕秸秆覆盖)条件下的土壤线虫c-p(colonizer-persister)类群及功能团,为评价保护性耕作的土壤生态效应提供理论依据。研究发现,与犁耕相比,保护性耕作显著增加了土壤线虫各c-p类群及绝大多数功能团的多度,但显著减少了Ba4和Om5功能团多度。此外,保护性耕作还改变了土壤线虫生活史和功能团的结构特征:在大部分研究土层,c-p1和c-p2线虫的相对多度显著提高,而c-p3、c-p4以及c-p3-5类群显著降低;Ba1、Ba2、Ba3、Fu4和H5功能团的相对多度显著提高,而Ba4、H3和Om5的相对多度显著降低,Fu2、H2和Om4相对多度的变化较复杂,在表土层表现为显著抑制,在15~30cm土层则为促进作用。土壤线虫c-p类群和功能团的多度及结构特征可能适合作为评价保护性耕作对土壤质量影响的生物学指标。

不同森林管理方案对森林景观长期影响的模拟研究

理解森林景观的动态变化对于制定合理的森林管理措施和恢复规划有着重要的现实意义。应用空间直观森林景观模型(LANDIS)模拟小兴安岭友好林业局在当前天保工程方案下(P1)、自然演替方案下(P2)以及采伐后完全依赖天然更新方案下(P3)森林景观的动态变化。模拟结果表明:不同的森林管理方案对树种分布面积百分比、空间格局和年龄结构有显著的影响。与其他两个方案比较,当前天保工程方案(P1)可以显著增加造林树种(红松、落叶松和蒙古栎)面积,提高树种的聚集程度,减小白桦所占面积,但是在模拟的前50年,人工更新造林措施使得幼龄林所占面积百分比显著增加,而成过熟林的增加以及建立合理的林龄结构仍需很长的时间。

不同针阔树种造林比例下小兴安岭森林景观的动态模拟

采用空间直观森林景观模型(LANDIS)模拟了不同针、阔树种造林比例(P1,100%阔叶树;P2,70%阔叶树、30%针叶树;P3,50%阔叶树、50%针叶树;P4,30%阔叶树、70%针叶树;P5,100%针叶树)和采伐后完全依赖天然更新(P6)6种预案下2001—2201年小兴安岭友好林业局森林景观的动态变化.结果表明:人工更新造林措施可以有效地促进研究区森林资源的恢复,但单一营造针叶树的预案会使其阔叶树的面积百分比低于P6预案,而单一地营造阔叶树会导致该预案下针叶树的面积百分比低于P6预案;随着针叶树种造林比例的增加,针叶树(红松和落叶松)所占面积比例随之增加;随着阔叶树种造林比例的增加,阔叶树(蒙古栎)所占面积亦随之增加;人工更新造林措施减少了研究区白桦的分布面积.不同的造林措施不仅改变树种所占的面积百分比,还影响其空间格局:随着针叶树种造林比例的增加,针叶树(红松和落叶松)的聚集度指数随之增加;随着阔叶树种造林比例的增加,阔叶树(蒙古栎)的聚集度指数随之增加;人工更新造林措施对白桦的聚集度指数无明显影响.

Synthesis and Properties of Carbazole Main Chain Copolymers with Oxadiazole Pendant toward Bipolar Polymer Host: Tuning the HOMO/LUMO Level and Triplet Energy

Three new carbazole copolymers, poly(9-(2,5-diarene-[1,3,4]oxadiazole)-carbazole-alt-9-(2-ethylhexyl)-carbazole-3,6-diyl)s (P1), poly(9-(2,5-diarene-[1,3,4]oxadiazole)-2, 7-carbazole-alt-9-(2-ethylhexyl)-3, 6-carbazole-diyl)s (P2), and poly(9-(2,5-diarene-[1,3,4]oxadiazole)-carbazole-alt-9-(2-ethylhexyl)-carbazole-2,7-diyl)s (P3), were synthesized by the Suzuki coupling reaction

Crystal structures and elastic properties of superhard IrN2 and IrN3 from first principles

First principles calculations were performed to investigate the structural, elastic, and electronic properties of IrN2 for various space groups: cubic Fm-3m and Pa-3, hexagonal P3(2)21, tetragonal P4(2)/mnm, orthorhombic Pmmn, Pnnm, and Pnn2, and monoclinic P2(1)/c. Our calculation indicates that the P2(1)/c phase with arsenopyrite-type structure is energetically more stable than the other phases. It is semiconducting (the remaining phases are metallic) and contains diatomic N-N with the bond distance of 1.414 A. These characters are consistent with the experimental facts that IrN2 is in lower symmetry and nonmetallic. Our conclusion is also in agreement with the recent theoretical studies that the most stable phase of IrN2 is monoclinic P2(1)/c. The calculated bulk modulus of 373 GPa is also the highest among the considered space groups. It matches the recent theoretical values of 357 GPa within 4.3% and of 402 GPa within 7.8%, but smaller than the experimental value of 428 GPa by 14.7%. Chemical bonding and potential displacive phase transitions are discussed for IrN2. For IrN3, cubic skutterudite structure (Im-3) was assumed.

Phase behavior of rare earth manganites

Among complex oxides containing rare earth and manganese BaLn(2)Mn(2)O(7)( Ln = rare earth) with the layered perovskite type and Ln(2)(Mn, M)O-7 with pyrochlore-related structure were studied since these compounds show many kinds of phases and unique phase transitions. In BaLn(2)Mn(2)O(7) there appear many phases, depending on the synthetic conditions for each rare earth. The tetragonal phase of so-called Ruddlesden-Popper type is the fundamental structure and many kinds of deformed modification of this structure are obtained. For BaEu2Mn2O7 at least five phases have been identified from the results of X-ray diffraction analysis with the space group P4(2)/mnm, Fmmm, Immm and A2/m in addition to the fundamental tetragonal I4/mmm phase. In the pyrochlore-related type compounds, Ln(2)Mn(2-x)M(x)O(7)(M = Ta, Nb, W etc), there also appear several phases With different crystal structures. With regard to every rare earth, Ln(2)MnTaO(7) phase is stable only for excess Ta and can be obtained under high oxygen partial pressure process. This group has trigonal structure with zirkelite type ( P3(1)21 space group).

Phenylene vinylene-based electroluminescent polymers with electron transport block in the main chain

We report a new route for the design of soluble phenylene vinylene (PV) based electroluminescent polymers bearing electron-deficient oxadizole (OXD) and triazole (TZ) moieties in the main chains with the aryloxy linkage. Both series of the PV-based polymers were prepared by Wittig reaction. By properly adjusting the OXD and/or TZ content through copolymerization, we can achieve an enhanced balance of hole- and electron injections, such that the device efficiency is significantly improved. Light-emitting diodes fabricated from P1, P2, P3, P4, P5, P6, and P7 with the configuration of Indium-Tin Oxide (ITO)/Poly (styrene sulfonic acid) doped poly (ethylenedioxythiophene) (PEDOT)/polymer/Ca/Al, emit bright green light with the maximum peak around 500 nm. For the device using the optimal polymer (P4) as emitting layer, a maximum brightness of 1300 cd/m(2) at 20 V and a maximum luminance efficiency of 0.325 cd/A can be obtained.

Preparation and characterization of post-derivatives from functional polystyrene (ATRP) with p-nitroaniline-azomethine phenol and their thermal and optical study

The functional polystyrene, (Cl-PS)(2)-CHCOOCH2CH2OH ( designated as XPSt and coded P2) was prepared by ATRP at 130(0)C using CuCl and bipyridine as catalysts, 2,2-dichloro acetate-ethylene glycol (DCAG) as multifunctional initiator and THF as solvent. 4-Nitoroaniline azomethine-4' phenol (P1) as chromophores were covalently linked to the functional end groups of the polymer by using simple displacement reaction. The functional polystyrenes, namely XPSt (P2) and (PS)(2)-CHCOOCH2CH2OH, designated as X-PSt and coded P3 and their post-derivatives, namely, DXPSt (P4) and DX-PSt (P5) respectively were characterized by IR, NMR and UV spectroscopies, gel permeation chromatography (GPC) and thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), polarising optical microscopy (POM) and XRD studies. DSC showed that incorporation of chromophores in the side chains of polymers towards the polystyrene moiety increases the rigidity of the polymer and subsequently, its glass transition temperature; however the incorporation of side chain towards the alcoholic functional group decreases the glass transition temperature. The post derivatives do not play any significant role to increase the thermal stability ( TGA).

Isolation and mapping of telomeric pentanucleotide (TAACC)(n) repeats of the pacific whiteleg shrimp, Penaeus vannamei, using fluorescence in situ hybridization

To develop genetic and physical maps for shrimp, accurate information on the actual number of chromosomes and a large number of genetic markers is needed. Previous reports have shown two different chromosome numbers for the Pacific whiteleg shrimp, Penaeus vannamei, the most important penaeid shrimp species cultured in the Western hemisphere. Preliminary results obtained by direct sequencing of clones from a Sau3A-digested genomic library of P. vannamei ovary identified a large number of (TAACC/GGTTA)-containing SSRs. The objectives of this study were to (1) examine the frequency of (TAACC)(n) repeats in 662 P. vannamei genomic clones that were directly sequenced, and perform homology searches of these clones, (2) confirm the number of chromosomes in testis of P. vannamei, and (3) localize the TAACC repeats in P. vannamei chromosome spreads using fluorescence in situ hybridization (FISH). Results for objective I showed that 395 out of the 662 clones sequenced contained single or multiple SSRs with three or more repeat motifs, 199 of which contained variable tandem repeats of the pentanucleotide (TAACC/GGTTA),, with 3 to 14 copies per sequence. The frequency of (TAACC)n repeats in P. vannamei is 4.68 kb for SSRs with five or more repeat motifs. Sequence comparisons using the BLASTN nonredundant and expressed sequence tag (EST) databases indicated that most of the TAACC-containing clones were similar to either the core pentanucleotide repeat in PVPENTREP locus (GenBank accession no. X82619) or portions of 28S rRNA. Transposable elements (transposase for Tn1000 and reverse transcriptase family members), hypothetical or unnamed protein products, and genes of known function such as 18S and 28S rRNAs, heat shock protein 70, and thrombospondin were identified in non-TAACC-containing clones. For objective 2, the meiotic chromosome number of P. vannamei was confirmed as N = 44. For objective 3, four FISH probes (P1 to P4) containing different numbers of TAACC repeats produced positive signals on telomeres of P. vannamei chromosomes. A few chromosomes had positive signals interstitially. Probe signal strength and chromosome coverage differed in the general order of P1 > P2 > P3 > P4, which correlated with the length of TAACC repeats within the probes: 83, 66, 35, and 30 bp, respectively, suggesting that the TAACC repeats, and not the flanking sequences, produced the TAACC signals at chromosome ends and TAACC is likely the telomere sequence for P. vannamei.