Characterization of cDNA encoding immunoglobulin light chain of the Mandarin fish (Siniperca chuatsi)

Immunoglobulin light chain cDNA sequences of a perciform fish, the mandarin fish Siniperca chuatsi were amplified from head kidney mRNA by reverse transcription (RT)-PCR and RACE methods using degenerated primer and gene specific ones. In cDNA sequences of the VL region, nucleotide exchanges were present mainly within CDRs, although a lesser degree of variability was also found in FRs. Moreover, the length of CDRI and CDR3 in the mandarin fish is shorter than in most other fish species. In the middle of S. chuatsi CL region, a microsatellite sequence (AGC)(6-8) was found, which is also present in another perciform species, the spotted wolffish (Anarhichas minor). The comparison of amino acid sequence of the mandarin fish CL domain with those of other vertebrates showed the highest degree of similarity of 94.5% to the spotted wolffish, while the similarity with rainbow trout (Oncorhynchus mykiss) Ig L1 (62.7%) and channel catfish (Ictalurus punctatus) Ig LG (55.9%) isotypes is also higher. However, there is only 50% identity in the VL regions between the mandarin fish and the wolffish. The sequence similarity of the mandarin fish CL domain with those of higher vertebrate did not readily allow it to be classified as kappa or lambda isotype. The phylogenetic analyses also demonstrated that the CL genes of the mandarin fish and most other teleost fish cluster as a separate branch out of the mammal kappa and lambda branches. (C) 2003 Elsevier B.V. All rights reserved.

Localized-Surface-Plasmon Enhanced the 357 nm Forward Emission from ZnMgO Films Capped by Pt Nanoparticles

The Pt nanoparticles (NPs), which posses the wider tunable localized-surface-plasmon (LSP) energy varying from deep ultraviolet to visible region depending on their morphology, were prepared by annealing Pt thin films with different initial mass-thicknesses. A sixfold enhancement of the 357 nm forward emission of ZnMgO was observed after capping with Pt NPs, which is due to the resonance coupling between the LSP of Pt NPs and the band-gap emission of ZnMgO. The other factors affecting the ultraviolet emission of ZnMgO, such as emission from Pt itself and light multi-scattering at the interface, were also discussed. These results indicate that Pt NPs can be used to enhance the ultraviolet emission through the LSP coupling for various wide band-gap semiconductors.

Photoluminescence of Mg-doped GaN grown by metalorganic chemical vapor deposition

Two Mg-doped GaN films with different doping concentrations were grown by a metalorganic chemical vapor deposition technique. Photoluminescence (PL) experiments were carried out to investigate the optical properties of these films. For highly Mg-doped GaN, the PL spectra at 10 K are composed of a blue luminescence (BL) band at 2.857 eV and two excitonic luminescence lines at 3.342 eV and 3.282 eV, in addition to a L2 phonon replica at 3.212 eV. The intensity of the L1 line decreases monotonously with an increase,in temperature. However, the intensity of the L2 line first slowly increases at first, and then decreases quickly with an increase in temperature. The two lines are attributed to bound excitonic emissions at extended defects. The BL band is most likely due to the transition from deep donor Mg-V-N complex to Mg shallow acceptor. From the temperature dependence of the luminescence peak intensity of the BL band, the activation energy of acceptor Mg was found to be 290 meV. (C) 2003 American Vacuum Society.

Magnetic Properties of FePt Nanoparticles Prepared by a Micellar Method

FePt nanoparticles with average size of 9 nm were synthesized using a diblock polymer micellar method combined with plasma treatment. To prevent from oxidation under ambient conditions, immediately after plasma treatment, the FePt nanoparticle arrays were in situ transferred into the film-growth chamber where they were covered by an SiO2 overlayer. A nearly complete transformation of L1(0) FePt was achieved for samples annealed at temperatures above 700 A degrees C. The well control on the FePt stoichiometry and avoidance from surface oxidation largely enhanced the coercivity, and a value as high as 10 kOe was obtained in this study. An evaluation of magnetic interactions was made using the so-called isothermal remanence (IRM) and dc-demagnetization (DCD) remanence curves and Kelly-Henkel plots (Delta M measurement). The Delta M measurement reveals that the resultant FePt nanoparticles exhibit a rather weak interparticle dipolar coupling, and the absence of interparticle exchange interaction suggests no significant particle agglomeration occurred during the post-annealing. Additionally, a slight parallel magnetic anisotropy was also observed. The results indicate the micellar method has a high potential in preparing FePt nanoparticle arrays used for ultrahigh density recording media.

RAM(h)模型下SpMV存储访问复杂度的分析

稀疏矩阵向量乘(SpMV)采取压缩行存储格式的算法性能非常差,而寄存器分块算法可以使得数据尽量在靠近处理器的存储层次中访问而提高性能.利用RAM(h)模型进行分析和比较不同算法形式的存储访问复杂度,可以比较两种算法的优劣.通过RAM(h)分析SpMV两种实现形式的存储访问复杂度,同时在奔腾四平台上,测试了7个稀疏矩阵的SpMV性能,并统计了这两种算法中L1,L2,和TLB的缺失率,实验结果与模型分析的数据一致.

钟控密钥流生成器及其密码性能

提出了一种新的钟控密钥流生成器,由3个移位寄存器组成:两个被钟控的线性反馈移位寄存器A和B,一个提供钟控信息的非线性反馈移位寄存器C。设A、B和C的长度分别为l1、l2和l3。移位寄存器A和B的钟控信息由从移位寄存器C选取的两个比特串提供,移位的次数分别是两个比特串的汉明重量。研究了该生成器的周期、线性复杂度和k错线性复杂度,分析了这种密钥流生成器的安全性。

杯[4]芳烃配位和超分子化学的研究

本论文依据主客体作用原理，从分子工程出发，主要利用各式杯芳烃主体与不同客体分子和金属离子进行组装，研究这类超分子的合成条件及规律，探讨主客体之间的相互影响及其自组装原理。 在第二章中，首先研究了银氨离子可诱导杯[4]芳烃(L1)形成超分子胶囊，接下来的工作中，我们对杯[4]芳烃进行修饰，合成了两种杯芳烃羧酸配体25, 26, 27, 28-tetrakis(carboxy methoxy)-calix[4]arene (L2) 和25, 26, 27, 28-tetrakis(carboxy methoxy)-p-t-butylcalix[4]arene (L3)；并分别以六次甲基四胺和三苯基膦为中性配体，构筑了一个由胶囊构筑的三维网络结构和一个四核银的簇合物。 在第三章中，用六次甲基四胺作为中性配体与银离子和对磺酸杯[4]芳烃进行组装，得到了一个纳米孔材料，在该结构中，银与六次甲基四胺形成的配位多聚体作为模板，诱导对磺酸杯芳烃排列形成孔道。由于模板的作用，拉大了杯芳烃之间的距离。 在第四章中，用pnno (pyrazine-N,N’-dioxide)作为客体分子，在稀土离子存在的情况下与杯芳烃进行超分子组装。不同的实验方法分别得到了由超分子胶囊构筑的三维网络结构和A-B-A 的双层结构。稀土Nd与 5,11,17,23- tetrasulfonato- 25,26,27,28-tetra- ethoxycarbonylmethoxyl-calix[4]arene (L4)组装时，得到了一个由氢键连接的层状化合物。 在第五章中，在水溶液条件下，[M(bpdo)22H2O]2+ (M=Zn, Cu; bpdo=2, 2’- bipyridine-N, N’-dioxide )诱导对磺酸基杯[4]芳烃形成超分子胶囊；并且该胶囊通过电荷辅助的π•••π作用与[M(bpdo)3]2+组装成纳米孔材料，气体吸附的测试表明该纳米孔对甲醇有一定气体吸附能力。当用稀土离子代替金属离子时，形成了类似的超分子胶囊和孔状结构。结果表明稀土孔材料比过渡金属孔材料具有更好的热稳定性。进一步研究通过改变配体bpdo为tpdo (tpdo=terpyridine-1, 1’, 1’-trisoxide)得到了一个层状化合物。 在第六章中，将新型的有机配体与丙基焦杯芳烃或甲基间苯二酚杯芳烃进行自组装得到新奇的杯芳烃超分子结构。这些新型的有机配体含有N-O或C=O 官能团的有机分子4,4'-dipyridyl N, N'-dioxide (L5), tetra-2-pyridinyl-N, N', N", N"'-tetraoxide- pyrazine (L6) and 1, 10-phenanthroline-5, 6-dione (L7)。它们是具有特殊的氢键受体和空间构型的有机分子，由于氢键等弱相互作用在形成超分子结构中的重要作用，三种不同的有机配体与杯芳烃自组装得到了三种不同的杯芳烃超分子结构。

SERS的基底、机理及在分子组装和生物分析中的应用研究

自表面增强Raman散射（SERS）在粗糙化的银电极上被首次发现以来，对于SERS的研究取得了很大的进展。主要集中在对SERS基底的构筑、SERS机理的解释以及SERS的应用方面，包括在表面科学及生物分析中的应用。本论文主要通过纳米合成及组装技术构筑了具有高活性、稳定性及重现性好的SERS基底，研究了SERS的电磁增强机理以及SERS在分子组装体与生物分析中的应用。关于SERS基底的构筑，我们主要合成了中空的银金纳米结构，在玻碳表面构筑了高SERS活性的银纳米簇、在水汽界面构筑了二维金纳米阵列及金纳米棒的聚集体膜作为SERS基底。我们还研究了处于金属纳米粒子-耦联分子-金属纳米粒子以及银纳米片-耦联分子-宏观金银两种三明治结构中耦联分子的SERS谱，得出存在于这两种三明治结构中的局域电磁耦合效应LSP-LSP (Localized Surface Plasmon)及LSP与宏观金银表面的表面等离子极化SPP (Surface Plamon Polartion)之间的电磁耦合效应，即LSP-SPP耦合。对于SERS的应用，我们首先研究了SERS在分子组装体方面的应用，得出分子在金属表面的吸附行为；同时利用SERS所具有的独特特征，分别研究了SERS在活体细胞以及构建适配子传感器方面的应用。具体工作如下： 1. SERS基底的构筑 采用种子调控的置换反应制备了中空的银金双金属纳米结构，研究了探针分子在其上的SERS效应; 采用静电组装的方法在玻碳表面构筑了具有SERS活性的银纳米簇；在水汽界面构筑了具有高SERS活性的二维金纳米阵列及金纳米棒的聚集体膜，同时研究了这些纳米结构作为SERS基底的特征。 2. SERS的电磁耦合增强机理 通过构筑金/银纳米粒子-耦联分子-银纳米粒子的三明治结构，研究了处于该结构中的耦联分子的SERS谱，得出存在于金银纳米粒子间的局域的表面等离子之间的耦合效应，即LSP-LSP电磁耦合；研究了处于宏观金/银-耦联分子-银纳米片的三明治结构中耦联分子的SERS谱，得出存在于这种三明治结构中的银纳米片的局域表面等离子共振与宏观金、银表面的表面等离子极化之间的电磁耦合效应，即LSP-SPP电磁耦合。 SERS在分子组装体方面的应用 首先通过SERS研究了硫醇类分子如4,4’-二巯基苯硫醚(4,4’-TBBT)在金表面的吸附，同时辅助其它表征手段如电化学、原子力等得出金属表面分子单层膜的吸附行为；通过SERS研究了该分子在银电极及银溶胶表面吸附行为的差异，得出该分子在银电极及银溶胶表面不同的吸附取向。 4. SERS在生物分析中的应用 利用SERS所具有的独特的特征，研究了染料分子在银纳米粒子上的SERS光谱及其作为光学探针在活体细胞中的应用；通过对纳米金进行适配子及Raman探针的标记构筑了对蛋白进行高灵敏度及选择性识别的SERS的适配子传感器。

二维纳米粒子阵列的制备及其拉曼光谱研究

随着纳米科学的迅速发展，金属纳米粒子以其独特的性能己被广泛应用于各学科的研究，由此发展起来的纳米物理、纳米化学、纳米材料和纳米电子学等新兴领域已经成为十分活跃的前沿研究方向。在纳米粒子的许多应用中，如：作为电子和光学器件中的结构组分，表面增强光谱中的基底，生物和化学传感器，都需要把纳米粒子固定在一个基底上构筑成一维，二维或三维有序的结构。本论文通过合成不同性质的金、银纳米粒子，采用自组装技术，在金属，玻璃和导电玻璃的表面成功构筑了有序的纳米结构，并研究由此带来的一系列新颖的光学性质及其作为新型的增强基底在表面增强拉曼光谱中的应用。本论文主要研究内容和结论如下：1、通过合成粒度分布均匀，性能稳定的金属银溶胶，利用自组装技术在玻璃表面成功构筑银纳米粒子的二维亚单层结构，利用UV一visible技术，发现在组装结构中银纳米粒子之间的相互作用对偶极子表面等离子体共振有较大的影响，这也可能意味着相邻银粒子间电磁场的增强与银粒子的偶极子模式间的偶合密切相关。2、利用自组装方法，分别在工T0电极和光滑银基底表面构筑了银纳米粒子有序结构，通过与分子吸附在粗糙银电极表面得到的增强拉曼光谱比较，在有序银纳米粒子组装体中藕联分子的拉曼散射得到很大增强，其特征谱峰的峰位置和强度都有变化。组装体中祸联分子对琉基苯胺（PATP）拉曼散射的增强归因于银粒子和银表面之间的电磁祸合，并且电磁场主要集中在银粒子和银基底表面之间的这一区域，即银粒子的局域等离子体（LSP）与银基底的表面等离子激元（SPP）的祸合作用。3、合成具有不同化学性质的银纳米粒子，利用对琉基苯胺作为祸联分子在光滑银基底表面构筑了Ag/PATP／Ag银纳米粒子二维组装阵列。利用表面增强拉曼光谱技术发现银溶胶中不同性质的银纳米粒子，即银溶胶纳米粒子表面吸附的阴离子对藕联分子与银基底之间的电荷传递有着重要的影响。4、利用表面增强拉曼光谱技术，发现苯功能衍生物：苯硫酚，对琉基苯胺和对苯硫酚在粗糙银电极上有着不同的吸附取向：苯硫酚是直立吸附，对琉基苯胺则是垂直吸附在银表面，而对苯硫酚采取平躺的吸附构像。5、利用电化学沉积法，在对琉基苯胺修饰的光滑的银电极表面构筑了银纳米粒子的有序二维结构，通过与利用自组装方法构筑的银粒子阵列中祸联分子表面增强拉曼光谱的研究比较，发现银离子在吸附层修饰的银电极表面进行电化学沉积可能采取两种机理：在双电层附近，溶液中的阴离子参予了整个过程，银粒子与基底之间存在静电吸引作用；银离子直接在吸附分子的氨基表面还原并成键，然后进一步的生长。6、利用电化学沉积法，在金纳米粒子表面沉积了一层汞，SEM，UV－vis及电化学实验证明在具有修饰层的导电玻璃（PVP一ITO）电极上成功合成了汞包金纳米粒子阵列，将汞电极表面的研究拓展到了分子水平。利用金纳米粒子产生的增强电磁场可以研究吸附在汞包金纳米粒子上的分子的表面增强拉曼光谱，简单分子对琉基苯胺在金纳米粒子阵列及汞包金纳米粒子阵列上采取同样的吸附方式，而复杂分子结晶紫在汞包金纳米粒子上采取一种接近平躺的方式吸附，而在金纳米粒子表面则是倾斜吸附的方式。进一步将汞包金纳米粒子阵列电极应用到分子的现场谱学中，从而为更好的理解汞电极上的电化学过程打下了基础。

A Low Power Dissipation Wide-Band CMOS Frequency Synthesizer for a Dual-Band GPS Receiver

This paper presents a wide tuning range CMOS frequency synthesizer for a dual-band GPS receiver,which has been fabricated in a standard 0.18μm RF CMOS process. With a high Q on-chip inductor, the wide-band VCO shows a tuning range from 2 to 3.6GHz to cover 2.45 and 3.14GHz in case of process corner or temperature variation,with a current consumption varying accordingly from 0.8 to 0.4mA,from a 1.8V supply voltage. Measurement results show that the whole frequency synthesizer consumes very low power of 5.6mW working at L1 band with in-band phase noise less than - 82dBc/Hz and out-of-band phase noise about - ll2dBc/Hz at 1MHz offset from a 3. 142GHz carrier. The performance of the frequency synthesizer meets the requirements of GPS applications very well.

稀疏矩阵向量乘的存储访问复杂度及自动性能优化技术应用研究

在科学计算中，稀疏矩阵向量乘（SpMV, y=Ax）是一个十分重要的，且经常被大量调用的计算内核，广泛应用在科学计算、信息检索、气象、航天、油藏模拟、天体物理、数据挖掘等科学计算和实际应用中。在实际工程应用中，重复调用稀疏矩阵向量乘内核的次数常常会达到成千上万次。但在现代基于Cache存储层次的计算平台上，稀疏矩阵向量乘的性能很低。如果能够提高稀疏矩阵向量乘的运算速度，整个工程计算的运行效率将会得到很大的改善，计算时间也会大幅度的减少。因此优化稀疏矩阵向量乘的性能成为提高工程效率的关键，在实际应用中有着十分重要的意义。 SpMV的传统算法实现形式运行效率很低，主要原因是浮点计算操作和存储访问操作比率非常低，且稀疏矩阵非零元分布的不规则性使得存储访问模式非常复杂。寄存器分块算法和启发式选择分块算法,通过自适应选择性能最佳的分块大小，然后将稀疏矩阵分成小的稠密分块，所有的非零子块顺序计算，达到重用保存在寄存器中向量x元素的目的，减少存储访问次数和时间，从而提高这一重要内核的性能。我们在Pentium IV、Alpha EV6和AMD Athlon三个平台上，分别测试了十个矩阵下的两种不同算法形式(压缩行存储算法和寄存器分块算法)的性能，平均加速比分别达到1.69、1.90和 1.48。同时也测试了不同次数调用SpMV两种算法所用的时间，发现在实际的迭代算法应用过程中，若想采用启发式-寄存器分块算法达到性能提高的目的，一般情况下，迭代次数需要达到上百次才能有加速效果。 DRAM(h)模型是基于存储层次的并行计算模型，指出算法的复杂性包括计算复杂性和存储访问复杂性，具有近乎相同时间和空间复杂性的同一算法的不同实现形式，会有不同的存储访问复杂度，导致程序实际运行性能的差异；利用DRAM(h)模型进行分析并比较不同算法实现形式的存储访问复杂度，可以判断两种算法形式的优劣，从而为选取性能更高的实现形式提供指导。但利用DRAM(h)模型分析SpMV存储访问复杂度的工作以前没有人做过，并且SpMV的计算性能和存储访问行为跟具体的稀疏矩阵有关，只有到程序运行的时候才能知道。本文中，我们提出模板法和动态统计分析法两种分析SpMV存储访问复杂度的方法。在Pentium IV和Alpha EV6平台上，用RAM(h) 模型分析和计算了稀疏矩阵向量乘两种算法实现形式（即压缩行存储算法和寄存器分块算法）的存储访问复杂度，通过分析和计算在SpMV过程中需要访问的所有数据的存储访问复杂度，可知存储访问行为对整体程序的实际性能有直接影响。我们还在Pentium IV平台上，测试了七个稀疏矩阵的SpMV性能，并统计了两种算法中L1, L2,和TLB的缺失率，实验结果与模型分析的结果一致。

辽东山区次生林生态系统主要树种幼苗对光环境的响应

辽东山区森林是辽宁省重要的水源涵养基地与用材林资源，在维系区域内生态环境和林产品的可持续供应方面占据十分重要的战略位置。该区的天然林已基本绝迹，因此该区的森林生态恢复具有重要意义。 已有研究表明，影响辽东山区森林更新演替最主要的环境因素是光环境。核桃楸（Juglans mandshurica）、水曲柳（Fraxinus mandshurica）、黄菠萝（Phellodendron amurense）和红松(Pinus koraiensis)是阔叶红松林的优势树种；这些树种幼苗对光环境的适应性差异，在群落演替和森林生态恢复中发挥重要作用。 本论文采用人为控制遮光试验测定了核桃楸、水曲柳和黄菠萝幼苗对光环境的响应，同时，采用自然光环境试验和人为控制遮光试验相结合的手段测定了红松幼苗对光环境的适应性。人为控制遮光试验设置的光环境类似于自然中的典型林窗、林缘和林下的光环境；在人为控制遮光试验中，研究材料于2007年4月末栽植于4个不同光环境（全光、全光的60%、30%和15%，分别记为FI、II、LI和WI处理）下，在2007年7~9月测定了树种幼苗的光合生理、叶片特征、生长和冠层形态特征等方面的变化，结果表明： 1）不同光环境处理区内的光合有效辐射（PAR）具有显著差异，形成一定的光强梯度，而气温，相对湿度和土壤含水量差异并不显著。全光处理区内的日平均PAR为842.4μmol∙m-2∙s-1，最大PAR为1884.1μmol∙m-2∙s-1，显著高于其它处理区。 2）生长在高光强下4个树种幼苗的叶片有较高的光合能力（Amax），随生长光强的下降，Amax显著下降；光补偿点（LCP）和光饱和点（LSP）也表现出随着生长光强的下降而降低的趋势。核桃楸和水曲柳净光合速率Pn的日变化最大值约为16μmol∙m-2∙s-1，黄菠萝的约为13μmol∙m-2∙s-1，这与温带阔叶树种叶片的最大净光合速率Pn在10~15μmol∙m-2∙s-1范围内的结论相符；3个苗龄红松针叶的Pn日变化均呈单峰型，没有光合“午休”现象，峰值出现在11:00~13:00期间。 3）4个树种幼苗的比叶重（LMA）和单位叶面积鲜重（LFA）均随着光环境的降低而下降；三个阔叶树种幼苗的叶长L、叶宽W、叶周长C和单叶面积A均具有随着光强的降低而呈增大的趋势，表明叶片通过调节叶片的形态来适应多变的光环境。 4）不同光环境对阔叶树种幼苗的植株冠形和生长有显著影响，而红松幼苗植株冠形和生长的变化无明显的规律性。 综上，本研究得出以下结论：○1.通过可塑性分析和模糊隶属函数分析，核桃楸和黄菠萝较水曲柳能适应更宽的光强幅度；同时，核桃楸和黄菠萝较水曲柳的需光性更强，核桃楸和黄菠萝的需光性差异不大。○2.与3年、5年生红松相比，7年生红松对光强的适应幅度最小；同时，7年生红松的需光性强于3年和5年生红松。○3.本研究结果支持前人的观点：红松在幼年阶段能耐一定程度的遮光，在全光的20%~60%光条件下生长较好，随着年龄的增大，红松的需光性增加。

瓦山安息香中苯并呋喃促雌激素合成的机理研究

雌激素是人体内重要的激素之一，具有广泛的生理功能。雌激素缺乏与许多疾病相关，如卵巢功能低下，更年期综合征以及骨质疏松等；雌激素过剩也将导致某些疾病，如乳腺癌、卵巢癌、子宫内膜癌等。目前，如何降低肿瘤组织中的雌激素水平而达到治疗肿瘤的目的，已经得到广泛的研究，但促雌激素生成或调节卵巢功能药物或其相关研究则很少。 本实验室前期的研究发现，瓦山安息香属植物果实中的乙醇提取物具有促雌激素生成作用，通过活性追踪和结构鉴定，确认促E2 生成的主要成分为苯并呋喃类化合物。苯并呋喃类化合物的作用与芳香酶有关，但其确切的作用机理有待证实和深入研究。 为了探讨安息香苯并呋喃类化合物的促雌激素合成的作用机理，拟采用如下的实验方案： 1、细胞学方面，对小鼠3T3-L1 前脂肪细胞、人乳腺癌细胞MCF-7、MDA-MB-231 以及人卵巢癌细胞OVCAR-3、OVCAR-4、OVCAR-5、OVCAR-8、IGROV1 等细胞株，采用RT-PCR 和ELISA 方法研究芳香酶Aro基因的表达和雌二醇E2 的生成，芳香酶抑制剂Formestane 作为阳性对照，研究时效曲线和量效曲线，确定安息香苯并呋喃类化合物SP25 的有效浓度和作用时间。 2、RNAi 方面，设计合成了针对人芳香酶Aro基因的3 对RNAi 序列，转染入细胞，芳香酶促进剂Forskolin 和地塞米松、芳香酶抑制剂Formestane 作为阳性对照，采用实时定量PCR 技术，研究RNA 干扰后，安息香苯并呋喃类化合物SP25 对人芳香酶Aro基因表达水平瓦山安息香苯并呋喃促雌激素合成的机理研究的影响。 3、雌激素受体方面，设计一段ERE 的雌激素调控元件，构建重组荧光素酶报告基因载体，瞬时转染人乳腺癌细胞株MDA-MB-231，建立针对雌激素受体的报告基因筛选模型，观察安息香苯并呋喃类化合物SP25 对雌激素受体的选择性和亲和力，从受体水平考察安息香苯并呋喃类化合物SP25 促进雌激素生成的药理学机理。 实验结果显示： 1、分化后的小鼠3T3-L1 前脂肪细胞、人乳腺癌细胞MCF-7 、MDA-MB-231 以及人卵巢癌细胞OVCAR-3、OVCAR-4、OVCAR-8 等细胞株具有芳香酶基因的表达。睾酮向雌二醇的转化能够被芳香酶抑制剂Formestane 所阻断，其中OVCAR-3 最适合进行下一步的RNAi研究。 2、RNAi 实验结果显示，设计的3 对RNAi 序列中R2 的干扰效果最强，相应的阴性对照C2 与R2 的表达量相差118 倍（24 小时）和19 倍（48 小时），显示R2/C2 这组序列可用于进一步的RNAi 试验。以R2 干扰OVCAR-3 细胞株，药物作用24、48 小时后，芳香酶抑制剂Formestane 与R2 相对表达量相比分别为0.83 倍和0.04 倍；芳香酶促进剂Forskolin 与R2 相对表达量相比分别为3.61 和1.84 倍；芳香酶促进剂地塞米松与R2 相对表达量相比分别为5.76 倍和3.49倍；苯并呋喃类化合物SP25 与R2 相对表达量相比分别为8.13 倍和4.59 倍。实验证实安息香苯并呋喃类化合物SP25 能够促进因RNAi 而发生基因沉默的人芳香酶Aro表达水平的上调。 3、雌激素受体实验结果显示，构建成功重组pERE-pGL3-promoter 荧光素酶报告基因载体和基于报告基因系统的雌激素受体激动剂或拮抗剂的细胞筛选模型。实验结果表明安息香苯并呋喃类化合物SP25 与雌激素受体ERα和ERβ亲和力选择性之比约为3：1 ，SP25通过与雌激素受体ERα结合作用其受体，刺激芳香酶的表达。 本课题通过RNA 干扰、ELISA、荧光实时定量PCR、报告基因筛选模型等技术手段，从细胞水平、蛋白酶水平和基因表达水平、雌激素受体水平等方面系统地研究了从瓦山安息香属植物果实中提取的苯并呋喃SP25 促进促雌激素生成的机理研究。试验结果显示苯并呋喃类化合物SP25 促雌激素生成的主要作用机制是直接促进芳香酶基因表达水平，以及与雌激素受体a 结合，刺激芳香酶活性。 Estrogen is an important hormone that has versatile physiologicalfunctions. Lack of estrogen will lead to many diseases such as lower ovarianfunction, climacteric syndrome and osteoporosis. Excessive estrogen alsoinduces breast carcinoma, oophoroma and endometrial carcinoma and otherdiseases. To depress the estrogen level in tumor tissue to cure carcinomawas widely studied, but there is only few studies reported on the induction ofestrogen and on the regulation of ovary function. We found that the extracts from seeds of Styrax perkinsiae couldpromote the synthesis of estrogen. The active compounds benzofurans wereidentified. Effect of benzofurans may be related to aromatase, but the mechanism was not clear. To reveal the mechanism of these benzofurans to promote estrogensynthesis, the following protocols were adopted: 1 Cytology: 3T3-L1 preadipocytes,human ovary carcinoma celllines OVCAR-3,OVCAR-4,OVCAR-5,OVCAR-8,IGROV1 andbreast carcinoma cell lines MCF-7 and MDA-MB-231 were usedto determine Aro gene expression and estrogen production withRT-PCR AND ELISA methods. Formestane, an aromataseinhibitor, was used as positive control. And dose-curve,time-curve and the effective concentration of SP25 were also studied. 2 Designed 3 pairs of RNAi for human aromatase gene, andtransfected into cell. Aromatase inducer Forskolin andDexamethasone, and aromatase inhibitor Formestane were usedas positive controls. We studied the change of Aro expressionlevel with SP25 by using real-time PCR after RNA interfering. 3 Estrogen Receptor: We constructed the recombined Luciferasereport vector and establish a screening system for estrogenagonist and antagon. With this system, we studied the affinity ofSP25 and estrogen receptor. Results: 1 Differentiated 3T3-L1 preadipocytes¡¢human ovary carcinomacell lines:OVCAR-3, OVCAR-4, OVCAR-8 and breast carcinomacell lines MCF-7, MDA-MB-231 had detected aromatase geneexpression.And OVCAR-3 is more suitable for further aromatasegene function research. 2 In RNAi assay, R2 has a strong interfering effcet in OVCAR-3 cellline, and ratio of C2 (the negative control) to R2 were 118 times(24 hours) and 19 times (48 hours). This means sucessful inRNA interfering. After R2 acted on OVCAR-3 cell line, the ratiosof formestane to R2 were 0.83 and 0.04 times, 5.76 and 3.49times (Dex), 3.61 and 1.84 times (forskolin) and 8.13 and 4.59times (sp25) after drug treated 24 or 48 hours respectively.These results indicated that SP25 can directly induce aromatasegene up-regulation. 3 We had constructed pERE-pGL3-promoter recombined vectorand the Luciferase report gene screening system. Luciferasereport gene assay showed that sp25 had a higher affinity with strogen receptor alpha than estrogen receptor beta, this indicated that SP25 can act on estrogen receptor and induce aromatase. Our results revealed that the mechanisms of benzofuran to promoteestrogen were the upregulation aromatase gene expression and promotion ofaromatase activity and have partially elective affinity with estrogen receptoralpha.

增温对川西北高寒草甸植物群落结构及几种主要植物生长和生理的影响

由于人类活动所引起的地球大气层中温室气体的富集已导致全球地表平均温度在20世纪升高了0.6 ℃，并预测在本世纪将上升1.4-5.8 ℃。气候变暖对陆地植物和生态系统影响深远，并已成为全球变化研究的重要议题。高海拔、高纬度地带的生态系统对气候变化最敏感。而在高原和高山极端环境影响下所形成的高寒草甸生态系统极其脆弱，对由于温室效应引起的全球气候变化极其敏感，对这些变化的响应更具有超前性。 本研究以川西北高寒草甸植物群落及几种主要物种为研究对象，采用国际山地综合研究中心（ITEX）普遍所采用的增温方法-----开顶式生长室（OTC）模拟气候变暖来研究增温对高寒草甸植物群落结构、物质分配及其主要物种生长和生理的影响，以探讨高寒草甸植物响应与适应气候变暖的生物学和生态学机制。主要研究结论如下： 1、OTC的增温效果 由于地温、地表温度和气温的平均值在OTC内分别高出对照样地0.28℃、0.46℃和1.4℃，这说明本研究所采用的开顶式生长室（OTC）起到了增温的作用；同时，由于温室内与温室外接受的降水量相同，温室内由于热量条件的改善，土壤蒸发和植被的蒸腾作用增强，直接导致了OTC内土壤表层相对湿度的减少。 2、群落结构对增温的响应 由于增温时间较短，增温内外样地的物种组成并未发生改变；但增温后一定程度上改变了植物群落的小气候环境，从而导致物种间的竞争关系被破坏，种间竞争关系的破坏引起群落优势种组成发生相应的改变，在对照样地，鹅绒委陵菜、甘青老鹳草、遏蓝菜和蚤缀是占绝对优势的物种，而在OTC内，小米草、尼泊尔酸模、垂穗披碱草、发草和羊茅的重要性显著增加。 禾草和杂草由于对增温的生物学特性及其资源利用响应的不同，加之增温造成土壤含水量下降等环境因子的改变。与对照样地相比较，OTC内禾草的盖度及生物量都显著增加，而杂草的盖度和生物量则显著下降。 3、植物生长期对增温的响应 OTC内立枯和调落物的生物量在生长季末（10月份）都要小于对照样地的立枯和调落物生物量，而OTC内的地上鲜体生物量在10月份却略高于对照样地。这说明OTC内植物的衰老或死亡得以延缓，而植物的生长期得以延长。 4、群落生物量及分配对增温的响应 OTC内的地上鲜体生物量(10月份除外)和地下0-30cm的根系生物量与对照样地相比较，都出现了不同程度的减少；土壤根系的分配格局也发生了明显的改变，其中，OTC内0-10cm土层的生物量分配比例增加，而20-30cm土层生物量分配比例的减少。 5、群落碳、氮对增温的响应 增温后，OTC内植物群落地上活体和地下活根的碳浓度不同程度的高于对照样地，植物群落的碳库在OTC内也略高于对照样地；而OTC内植物群落地上活体和地下活根的氮浓度不同程度的低于对照样地，其植物群落的氮库与对照样地相比也略有下降。 6、几种主要植物的生长及物质分配对增温的响应 垂穗披碱草在增温后株高、比叶面积和地上生物量均显著地增加；尼泊尔酸模在增温后比叶面积和单株平均生物量积累显著地增加，而各组分中，增温处理使叶的生物量显著增加，而根的生物量却显著下降；鹅绒委陵菜在增温后株高、比叶面积和单株平均生物量积累显著地减少，而各组分中，增温处理使叶和茎的生物量显著减少，根的生物量却显著地增加。 尼泊尔酸模的LMR、RMR、R/S、根部碳含量、碳和氮在叶片与根部的分配比例在增温后显著地增加，而SMR、根部氮含量、碳和氮在茎部的分配比例在增温后却显著地降低；鹅绒委陵菜的RMR、R/S、碳和氮在根部的分配比例在增温后显著地增加，而SMR、LMR、碳在叶片的分配比例在增温后却显著地降低 7、几种主要植物的光合生理过程对增温的响应 增温使垂穗披碱草和尼泊尔酸模叶片中的叶绿素a、叶绿素b、总叶绿素含量显著增加；而鹅绒委陵菜叶片的叶绿素a、叶绿素b、总叶绿素含量在增温后显著减少，类胡萝卜素含量在增温后却显著增加。 增温对3种植物的气体交换产生了显著影响。其中，垂穗披碱草和尼泊尔酸模叶片的光响应曲线在增温后明显高于对照处理，A、E、gs、Pmax、、Rday、AQY和LSP显著增加，而LCP则显著降低；鹅绒委陵菜的光响应曲线在增温后则明显的低于对照处理，A、E、gs、Pmax、、Rday、AQY和LSP显著减少，而LCP则显著增加。 增温后垂穗披碱草和尼泊尔酸模叶片的Fv/Fm、Yield和qP显著增加；而鹅绒委陵菜叶片的Fv/Fm、Yield和qP则显著减少，qN却显著地增加。 8、几种主要植物的抗氧化酶系统对增温的响应 增温使垂穗披碱草和尼泊尔酸模体内抗氧化酶活性和非酶促作用有所提高，植物膜脂过氧化作用降低；鹅绒委陵菜叶片中酶促反应和非酶促反应在增温后也显著提高，但可能由于增温后的土壤干旱超过了鹅绒委陵菜叶的抗氧化保护能力，抗氧化酶活性及非酶促反应（脯氨酸、类胡萝卜素）的提高不足以完全清除干旱诱导形成的过量活性氧，因此叶片的膜脂过氧化程度仍然显著提高。 Enrichment of atmospheric greenhouse gases resulted from human activities such as fossil fuel burning and deforestation has increased global mean temperature by 0.6 ℃ in the 20th century and is predicted to increase in this century by 1.4-5.8 ℃. The global warming will have profound, long-term impacts on terrestrial plants and ecosystems. The ecoologcial consequences arising from global warming have also become the very important issuses of global change research. The terrestrial habitats of high-elevation and high-latitude ecosystems are regarded as the most sensitive to changing climate. The alpine meadow ecosystme, which resulted from the composite effects of mountain extreme climatic factors in Tibetan Plateau, is thus thought to be especially vulnerable and sensitive to global warming. In this paper, the response of plant community and several main species in the alpine meadow of Northewst Sichuan to experimemtal warming was studied by using open-top chambers (OTC). The aim of the this study was to research the warming effects on plant community structure, substance allocation, growth and physiological processes of several mian species, and to explore the biological and ecological mechanism of how the alpine meadow plants acclimate and adapt to future global warming. The results were as follows: 1. Warming effects of OTC The mean soil temperature, soil surface temperature and air temperature in OTC manipulation increased by 0.28℃、0.46℃ and 1.4℃ compared to the control during the growing season. This suggested that the OTC used in our study had increased temperature there. Meanwhile, the OTC manipulation slightly altered thermal conditions, but the same amount of precipitation was supplied to both the OTC manipulation and the control, so higher soil evaporation and plant transpiration in OTC manipulation directly lead to the decrease of soil surface water content. 2. The reponse of community structure to experimental warming The species richness was not changed by the short-term effect of OTC manipulation. However, experimental warming changed the microenvironment of plant community, therefore competitive balances among species were shift, leading to changes in species dominance. In the present study, the dominant plant species in the control plots were some forbs including Potentilla anserine, Geranium pylzowianum, Thlaspi arvense and Arenaria serpyllifolia, however, the importance value of some gramineous grasses including Elymus nutans, Deschampsia caespitosa, Festuca ovina, and some forbs including Euphrasia tatarica and Rumex acetosa significantly increased in OTC. The different biology characteristics and resource utilizations between gramineous grasses and forbs, and enhanced temperature caused change in some environment factors such as soil water content. As a result, the coverage and biomass of gramineous grasses significantly increased in OTC compared to the control, however, the coverage and biomass of forbs singnifciantly decreased in OTC compared to the control. 3. The reponse of plant growing season to experimental warming Both the standing dead and fallen litter biomass in OTC were lower than those in the control in October, and the biomass of aboveground live-vegetation in OTC was higher than that of the control. The results indicated that the senescence of plants was postponed, and the growing season was prolonged in our research. 4. The reponse of community biomass accumulation and its allocation to experimental warming Experimental warming caused the decrease of aboveground live biomass and belowground root biomass except for the aboveground live biomass in October. Experimental warming also had pronounced effects on the pattern of root biomass allocation. In the present study, the root biomass in 0-10cm soil layer increased in OTC manipulation compared to the control, however, the root biomass in the 20-30cm soil layer decreased in OTC manipulation compared to the control. 5. The reponse of community C and N content to experimental warming The C concentration and stock in aboveground live and belowground root both increased in OTC manipulation compared to the control. However, the N concentration and stock in aboveground live and belowground root both decreased in OTC manipulation compared to the control. 6. The reponse of gowth and biomass, C and N alloction of several species to experimental warming Experimental warming significantly increased the height, SLA (specific leaf area) and aboveground biomass of Elymus nutans in OTC manipulation compared to the control. The SLA and total biomass of Rumex acetosa also significantly increased in OTC manipulation compared to control, among the different components of Rumex acetosa, leaf biomass significantly increased, but root biomass significantly decreased in OTC manipulation compared to the control. However, the height, SLA and total biomass of Potentilla anserina significantly decreased in OTC manipulation compared to the control, among the different component of Potentilla anserina, leaf and stem biomass significantly decreased, but root biomass significantly increased in OTC manipulation compared to the control. The LMR (leaf mass ratio), RMR (root mass ratio), R/S (shoot/root biomass ration) and root C concentration of Rumex acetosa significantly increased in OTC manipulation compared to outside control, also, Rumex acetosa allocated relatively more C and N content to leaf and root in response to experimental warming, however, the SMR (stem mass ration) and root N concentration of Rumex acetosa significantly decreased in OTC manipulation compared to outside control, also, Rumex acetosa allocated relatively less C and N content to stem in response to experimental warming. The RMR and R/S of Potentilla anserina significantly increased in OTC manipulation compared to outside control, also, Potentilla anserina allocated relatively more C and N content to root in response to experimental warming, however, the SMR and LMR of Potentilla anserina significantly decreased in OTC manipulation compared to outside control, also, Potentilla anserina allocated relatively less C and N content to leaf in response to experimental warming. 7. The reponse of physiological processes of several species to experimental warming Experimental warming significantly increased chlorophyll a, chlorophyll b and total chlorophyll of Elymus nutans and Rumex acetosa in OTC manipulation compared to outside control. However, chlorophyll a, chlorophyll b, total chlorophyll and carotenoid of Potentilla anserina in OTC manipulation significantly decreased compared to outside control. Experimental warming had pronounced effects on gas exchange of Elymus nutans, Rumex acetosa and Potentilla anserine. In the present study, warming markedly increased the light response curves of Elymus nutans and Rumex acetosa in OTC manipulation compared to outside control, and also singnificantly increased A (net photosynthesis rate), E (transpiration rate), gs (stomatal conductance), Pmax (maximum net photosynthetic rate), Rday (dark respiration rate), AQY (apparent quantum yield) and LSP (light saturation point), but LCP (photosynthetic light compensation) of Elymus nutans and Rumex acetosa in OTC manipulation singnificantly decreased compared to outside control. However, warming markedly decreased the light response curves of Potentilla anserina in OTC manipulation compared to outside control, and also singnificantly decreased A, E, gs, Pmax, Rday, AQY and LSP, but LCP of Potentilla anserina in OTC manipulation singnificantly increased compared to outside control. Experimental warming singnificantly increased the chlorophyll fluorescence kinetics parameters such as Fv/Fm, Yield and qP of Elymus nutans and Rumex acetosa and qN of Potentilla anserina in OTC manipulation, but Fv/Fm, Yield and qP of Potentilla anserina in OTC manipulation singnificantly decreased. 8. The reponse of antioxidative systems of several species to experimental warming Experimental warming tended to increase the activities of antioxidative enzymes and stimulate the role of non-enzymes of Elymus nutans and Rumex acetosa. As a result, MDA content of Elymus nutans and Rumex acetosa decreased. The activities of antioxidative enzymes and non-enzymes of Potentilla anserina also significantly increased in OTC manipulation, but more O2- was produced because of lower soil water content, and the O2- accumulation exceeded the defense ability of antioxidative systems and non-enzymes fuctions. As a result, MDA content of Potentilla anserine still increased in OTC manipulation compared to outside control.

Au LX射线发射截面和Al、Ti、Ni表面可见、红外光谱测量

本实验工作是在中国原子能科学研究院的HI-13串列加速器国家实验室第二测量厅原子物理实验平台上完成。本工作采用能量为20-50MeV的高电荷态O5+离子去轰击Au, 测量了不同能量下Au的L1、Lα、Lβ、Lγ的X射线谱，计算了不同能量下各条X射线的产生截面，并与ECPSSR理论计算结果进行了比较。实验结果表明σ（Ll）/σ(Lα) 和σ（Lγ）/σ(Lα)与ECPSSR理论计算结果符合比较好，而对于σ（Lβ）/σ(Lα)，在较低能区实验值略高于理论值。在中国科学院近代物理研究所320kV高电荷态离子实验研究平台上测量了Xeq+ (q=17-29)入射Al、Ti和Ni等表面诱发的可见光和红外光。通过对靶原子光谱线的研究，实验发现，随着入射离子的电荷态增高，原子和离子的各种光谱线可得到有效地激发。低速高电荷态离子入射金属固体表面，靶原子的特征谱线的激发强度，与入射离子的电荷态q密切相关。qc的实验测量值和理论计算值符合的较好