BRCA1对人乳腺癌细胞辐射敏感性的影响及其作用机制研究

目的：研究肿瘤抑制子BRCA1在人乳腺癌细胞辐射抗性中的作用，并探讨其作用机制。材料和方法：利用实时细胞分析系统检测辐射对细胞存活的影响；流式细胞术检测辐射对细胞周期分布的影响；RT-PCR检测辐射导致的BRCA1、Bax和Bcl-2在 mRNA水平变化；Western blot方法检测辐射诱导的蛋白表达水平的变化； In-cell western定量检测辐射引起的蛋白表达水平的变化； AO/EB染色法检测辐射导致的细胞死亡情况。结果：第一，分别用1Gy和4Gy x射线和碳离子束辐照人乳腺癌细胞MCF-7，研究MCF-7对不同LET射线的辐射敏感性差异。结果显示，x射线组1Gy辐射导致细胞存活显著下降，4Gy辐射对细胞存活影响不明显；而碳离子束辐射对细胞生长无抑制作用。与x射线组比较，碳离子辐射诱导了更低的亚“G1”期细胞百分数和更显著的G2期阻滞现象。同时碳离子束辐射诱导BRCA1磷酸化水平和p21表达上调，Bax表达下调。以上结果表明MCF-7对辐射的耐受性与凋亡功能相关，而BRCA1 Ser-1524磷酸化作用可能参与细胞周期和凋亡的信号调控。第二，研究BRCA1在咖啡因诱导的辐射增敏效应中作用。当2mM咖啡因联合4Gy的x射线或碳离子束辐射处理MCF-7细胞后，观察到细胞存活显著下降，辐射诱导的G2期阻滞被废除，BRCA1和p21蛋白表达被抑制，而p53表达水平无明显变化。结果表明咖啡因诱导的MCF-7细胞的辐射增敏作用可能与G2期阻滞被废除相关，BRCA1可能参与该过程的信号调节。第三， 利用BRCA1功能正常的MCF-7细胞和BRCA1功能缺失的HCC1937细胞进一步研究BRCA1对细胞辐射敏感性的影响。辐射显著抑制了HCC1937细胞存活，但对MCF-7细胞存活无明显影响。与HCC1937细胞相比，辐射诱导MCF-7细胞发生显著的G2期阻滞。辐射诱导HCC1937细胞发生晚期凋亡，而MCF-7细胞则多发生早期凋亡，且MCF-7细胞凋亡数明显少于HCC1937细胞。RT-PCR检测结果显示，辐射增强了MCF-7细胞中BRCA1的mRNA 水平，抑制了Bax的mRNA 水平，对Bcl-2的影响不明显；而HCC1937细胞中Bax的mRNA表达水平则被增强。同时辐射诱导MCF-7细胞中BRCA1和p21蛋白表达增强，Bax表达下降，Bcl-2水平略有增高。而HCC1937细胞Bax表达水平增强，但p21和Bcl-2的表达水平则检测不到。这些结果表明，正常的BRCA1功能对Bcl-2的转录表达是必须的，BRCA1通过上调p21水平，下调Bax/Bcl-2影响细胞的辐射敏感性。结论： BRCA1在人乳腺癌细胞的辐射抗性发生中发挥重要作用，BRCA1通过上调p21水平诱导G2期阻滞，下调Bax/Bcl-2抑制凋亡信号，使得细胞对辐射诱导的凋亡产生抗性，最终导致细胞对辐射产生耐受性

低价林早期诊断:生态因子途径

提出了低价林早期诊断的新思路 ,即根据低价林的形成规律 ,在林分还未表现出低价林状况时就能诊断出其发展趋势 ,以便及时采取相应的经营管理措施 .以辽西油松林为例 ,从生态因子途径开展了低价林的早期诊断研究 ,建立了基于单因素实验和判别分析的生态因子途径早期诊断技术 .研究表明 ,土层厚度X1、有机质含量X2 、土壤全氮含量X3 、土壤含水率X4、土壤微生物总数量X5可选择作为油松低价林早期诊断的敏感指标 ;在综合诊断时引入了判别分析的数量分类方法 ,并根据判别分析的思路建立了油松林生长状况生态因子途径早期诊断方法 ,其步骤 :1)确定判别指标 ;2 )建立判别函数Y =1.5 96X1-0 .5 1X2 - 3.196X3 +1.6 2 2X4+1.898X5;3)通过判别函数和研究对象的各项判别指标值进行早期诊断 .低价林早期诊断的技术与方法尚有待进一步地研究、检验和完善 .

基于RS的东北平原杨树人工林生长模型的研究

利用遥感技术和多元回归方法,分析了东北平原杨树人工林的立地因子与TM(thematic mapper)影像的关系,建立杨树林生长与植被因子和土壤因子的关系,拟合立地因子——林木生长模型。结果表明:在吉林省农安县南部的防护林类型中,以可溶性总盐(X1)和pH值(X2)为影响林木高(H)生长的主导因子,回归方程为:H=8.431-119.699X1+1.617X2(P<0.01);在吉林省农安县北部防护林类型中,以有机质含量(X1)和0.01～0.25mm粒级含量(X2)为影响林木高(H)生长的主导因子,回归方程为:H=16.421+2.616X1-0.089X2(P<0.01)。回归关系达到了显著水平,根据立地因子,可以预测东北平原农田防护林中的双杨快杨(Populus×xiaozhuanica)和北京杨(Populus×beijingensis)的林木生长状况。

沈阳城市森林三维绿量模拟及其影响因子

为探求便捷有效的小面积城市森林三维绿量的测算方法,根据林木生长的分形原理,采用逐步回归方法获取了沈阳城市森林三维绿量的13个模拟方程,并对其影响因素进行分析.结果表明:13个模拟方程的决定系数(R2)在0.612~0.842,残差分析没有呈现明显图样,模型精度均在87%(α=0.05)和83%(α=0.01)以上,其中最便捷的模拟方程是ln■=7.468+0.926 lnx1[■为模拟三维绿量,x1为每公顷胸高断面积(SDB)].模拟方程的标准回归系数与16个树木特征间的相关关系显示,影响沈阳城市森林三维绿量的最主要因素是每公顷胸高断面积(SDB).

Prediction of molar absorptivities of color reagents and their color reactions with yttrium by artificial neural networks

The new topological indices A(x1)-A(x3) suggested in our laboratories were applied to the study of structure-property relationships between color reagents and their color reactions with yttrium. The topological indices of twenty asymmetrical phosphone bisazo derivatives of chromotropic acid were calculated. The work shows that QSPR can be used as a novel aid to predict the molar absorptivities of color reactions and in the long term to be helpful tool in-color reagent design. Multiple regression analysis and neural network were employed simultaneously in this study. The results demonstrated the feasibility and the effectiveness of the method.

Quantitative structure-property relationships for colour reagents and their colour reactions with cerium using computational neural networks

Quantitative structure-activity/property relationships (QSAR/QSPR) studies have been exploited extensively in the designs of drugs and pesticides, but few such studies have been applied to the design of colour reagents. In this work, the topological indices A(x1)-A(x3) suggested in this laboratory were applied to multivariate analysis in structure-property studies. The topological indices of 43 phosphone bisazo derivatives of chromotropic acid were calculated. The structure-property relationships between colour reagents and their colour reactions with cerium were studied using A(x1-Ax3) indices with satisfactory results. The purpose of this work was to establish whether QSAR can be used to predict the contrasts of colour reactions and in the longer term to be a helpful tool in colour reagent design.

Prediction of molar absorptivities of color reagents during their color reactions with cerium using multiple regression analysis and neural network

A quantitative structure-property study has been made on the relationship between molar absorptivities (epsilon) of asymmetrical phosphone bisazo derivatives of chromotropic acid and their color reactions with cerium by multiple regression analysis and neural network. The new topological indices A(x1) - A(x3) suggested in our laboratory and molecular connectivity indices of 43 compounds have been calculated. The results obtained from the two methods are compared. The neural network model is superior to the regression analysis technique and gave a prediction which was sufficiently accurate to estimate the molar absorptivities of color reagents during their color reactions with cerium.

Quantitative structure-property relationships for colour reagents and their colour reactions with ytterbium using regression analysis and computational neural networks

In this paper, the new topological indices A(x1)-A(x3) suggested in our laboratory and molecular connectivity indices have been applied to multivariate analysis in structure-property studies. The topological indices of twenty asymmetrical phosphono bisazo derivatives of chromotropic acid have been calculated. The structure-property relationships between colour reagents and their colour reactions with ytterbium have been studied by A(x1)-A(x3) indices and molecular connectivity indices with satisfactory results. Multiple regression analysis and neural networks were employed simultaneously in this study.

STRUCTURE-PROPERTY RELATIONSHIP BETWEEN HALF-WAVE POTENTIALS OF ORGANIC-COMPOUNDS AND THEIR TOPOLOGY

A significant correlation was found between half-wave potentials of organic compounds and their topological indices, A(x1), A(x2), and A(x3). The simplicity of calculation of the index from the connectivity in the molecular skeleton, together with the significant correlation, indicates its practical value. Good results have been obtained by using them to predict the half-wave potentials of some organic compounds.

NEW TOPOLOGICAL INDEX AND PREDICTION OF PHASE-TRANSFER ENERGY FOR PROTONATED AMINES AND TETRAALKYLAMINES IONS

The applications of new topological indices A(x1)-A(x3) suggested in our laboratory for the prediction of Gibbs energy values of phase transfer (water to nitrobenzene) of amine ions are described with satisfactory results. Multiple regression analysis and neural network were employed simultaneously in this study.

STUDY ON STRUCTURE-ACTIVITY-RELATIONSHIPS OF ORGANIC-COMPOUNDS - 3 NEW TOPOLOGICAL INDEXES AND THEIR APPLICATIONS

In this paper, three new topological indices, A(x1), A(x2), and A(x3), have been developed for use in multivariate analysis in structure-property relationship (SPR) and structure-activity relationship (SAR) studies. Good results have been obtained by using them to predict the physical and chemical properties and biological activities of some organic compounds.

Factors influencing the climatological mixed layer depth in the South China Sea: numerical simulations

The mixed layer depth (MLD) in the upper ocean is an important physical parameter for describing the upper ocean mixed layer. We analyzed several major factors influencing the climatological mixed layer depth (CMLD), and established a numerical simulation in the South China Sea (SCS) using the Regional Ocean Model System (ROMS) with a high-resolution (1/12A degrees x1/12A degrees) grid nesting method and 50 vertical layers. Several ideal numerical experiments were tested by modifying the existing sea surface boundary conditions. Especially, we analyzed the sensitivity of the results simulated for the CMLD with factors of sea surface wind stress (SSWS), sea surface net heat flux (SSNHF), and the difference between evaporation and precipitation (DEP). The result shows that of the three factors that change the depth of the CMLD, SSWS is in the first place, when ignoring the impact of SSWS, CMLD will change by 26% on average, and its effect is always to deepen the CMLD; the next comes SSNHF (13%) for deepening the CMLD in October to January and shallowing the CMLD in February to September; and the DEP comes in the third (only 2%). Moreover, we analyzed the temporal and spatial characteristics of CMLD and compared the simulation result with the ARGO observational data. The results indicate that ROMS is applicable for studying CMLD in the SCS area.

中国对虾育种方法研究与遗传连锁图谱的构建

本研究以中国对虾为材料，以杂交育种和选择育种为目标，进行了系统的中国对虾杂交育种试验、生长性状遗传参数试验及其分子遗传连锁图谱的构建工作。结果表明以不同地理群体杂交作为基础群体，然后采用系统的选择育种方法可以获得较好的选择效果。构建的遗传连锁图谱为中国对虾分子辅助育种提供一定的基础。这些试验结果为中国对虾合理系统的育种工作提供了理论基础和数据支持。其具体结果如下： 1. 试验对中国对虾黄渤海水域乳山湾群体（WYP）和朝鲜半岛南海群体（WKN）的2个群体及其杂交后代不同月龄生长情况和存活率进行了研究，测量体长（TL）、头胸甲长（CL）、头胸甲宽（CW）、第2、3腹节高（HST）、第2、3腹节宽（WST）、体重（BW）和存活率共7个性状，计算各项指标的杂种优势率，并对各性状进行了方差分析和多重比较。其3月龄生长情况和存活率研究结果表明，存活率在乳山湾群体（WYP♀）× 朝鲜半岛南海群体（WKN♂）杂交后代出现杂种劣势外，其他指标都表现出不同程度的杂种优势(4.37%～23.96% )。除了存活率外，杂交后代生长性状均显著高于亲本，乳山湾群体（WYP♀）×朝鲜半岛南海群体（WKN♂）杂交后代高于朝鲜半岛南海群体（WKN♀）× 乳山湾群体（WYP♂）杂交后代，黄渤海水域乳山湾群体高于朝鲜半岛南海群体后代。为确定测量性状与中国对虾体重的相关程度，建立了用体长(X1)，头胸甲宽(X2)，第2、3腹节宽(X3)，头胸甲长(X4)，第2、3腹节高(X5)估计体重的多元回归方程：Y = －2.056 + 0.03X1 + 0.076X2 + 0.078X3 + 0.033X4 + 0.043X5。 2. 中国对虾黄渤海水域乳山湾群体（WYP）和朝鲜半岛南海群体（WKN）2个群体及其杂交后代在4月龄时期的6个生长指标和存活率的杂种优势范围在0.514%到14.95%之间，WYP♀×WKN♂杂交后代在这7个指标中都高于WKN♀×WYP♂杂交后代。5月龄杂交后代也表现出一定程度的杂种优势，其范围在-9.000%～19.090%之间，但头胸甲长、第2、3腹节处高和存活率3个指标出现杂种劣势。不同杂交组合各个阶段生长发育情况和存活率在杂种优势表现出一定的规律。随着月龄的增加，WKN♀×WYP♂杂交后代杂种优势率有所增加，而WYP♀×WKN♂杂交后代的却有所降低。ANOVA分析结果表明，杂交后代在存活率方面与双亲差异不显著。4月龄的分析结果发现杂交后代在WST和BW这2个指标上存在显著差异。LSD多重比较结果显示，WYP♀×WKN♂杂交后代在BW指标上与亲本存在显著差异，在WST指标方面与其他3个组合的后代差异显著。5月龄的数据分析结果发现，杂交后代除体重存在显著差异外，其他各项指标差异均不显著。LSD多重比较结果发现，WKN♀×WYP♂杂交后代体重与其亲本WKN存在显著差异。 3. 对2个野生群体——朝鲜半岛南海岸群体（WKN）和黄渤海群体（WYP）和3个养殖群体——朝鲜半岛群体的养殖一代（FKN），黄海1号（HH1）和即抗98（JK98）进行杂交试验的研究，结果表明JK98 (♀)  WKN (♂)组合在存活率方面最高，其余的依次为WYP (♀) WKN (♂)，WKN (♀) WYP (♂)，FKN (♀)HH1 (♂) 和 WYP (♀) FKN (♂)。而在体重方面FKN(♀)  HH1(♂)组合最高，其余的依次为WKN (♀) WYP (♂)，WYP (♀) WKN (♂)，WYP (♀)FKN (♂) 和 JK98 (♀)WKN (♂)。在所有生长性状方面，JK98 (♀)  WKN (♂)在5个组合中是最低的。方差检测结果表明，TL、CL、HST、LL和BW这5个指标在不同组合间存在差异，而其他指标不存在差异。多重比较结果发现JK98 (♀)WKN (♂)组合的TL与其他组合间差异极显著，HST指标与WKN (♀) WYP (♂)，FKN(♀)  HH1(♂)和 WYP (♀)  WKN (♂)这3个组合差异显著，BW指标与WKN (♀) WYP (♂) 和 FKN(♀)  HH1(♂)差异显著。 4. 通过人工授精的方法建立了中国对虾21个半同胞家系，测量了中国对虾21个半同胞（46个全同胞）家系的TL、CL、CW、HST、WST、第1腹节长（FL）、第6腹节长（LL）。利用MTDFREML软件得到生长性状遗传力在0.15~0.35之间，属于中度遗传力范围。TL的遗传力为0.34±0.071，CL的为0.30±0.070，CW为0.35±0.077，WST为0.33±0.073，HST为0.33±0.073，FL的最低为0.15±0.044，LL的为0.24±0.059。各个性状间表现出高的正相关，其中CW和TL以及HST的遗传相关最大，FL和WST的遗传相关最小。 通过以上杂交育种和选择育种的研究，认为单纯的依靠杂交育种来改善中国对虾的育种工作可能具有一定的局限性。所以在实际的育种过程中，以中国对虾不同群体的杂交后代作为基础群体，并以此为基础进行系统的选择育种应该具有更大的潜力。 5. 本试验利用中国对虾F2群体和AFLP分子标记技术进行了遗传连锁图谱的构建。利用55对AFLP引物组合对F2家系的110个个体进行了研究，结果检测到532个符合作图策略的AFLP标记。利用卡方检验检测分离位点是否符合孟德尔分离定律。对于符合3：1比例的分离位点利用F2自交模型构建性别平均连锁图谱，对于符合1：1比例的分离位点利用拟测交理论分别构建中国对虾的雌性和雄性遗传连锁图谱。雌性、雄性和性别平均遗传图谱分别有28、35和44个连锁群，图谱实际长度分别为1090、1617和1772.1 cM。中国对虾遗传连锁图谱估计基因组长度为2420 cM，符合与人类基因组相比的对虾类基因组长度。中国对虾雄性遗传连锁图谱比雌性遗传连锁图谱长32.6%，这可能说明中国对虾不同性别存在不同的重组率。通过皮尔逊相关系数检测认为AFLP标记在中国对虾图谱上分布均匀。本文利用AFLP标记构建的中国对虾遗传连锁图谱为中国对虾基因组研究和遗传改良提供一定的基础，同时也应该开发微卫星等共显性标记，为遗传连锁图谱的整合提供条件。

春小麦新种质陇矮l号矮秆性状的遗传研究

为了深入了解眷小麦新创种质陇矮1号的矮秆性遗传规律，2000～200l午对“陇矮1号”的矮秆遗传特性进行了较为系统的研究。从“陇矮1号”分别与三个高秆亲本“老芒麦”、“和尚头”和“高原602”的杂种F-1代株高表现可知，其F3代株高介于高亲值与中亲值之间，且D为负值，说明“陇矮1号”的矮秆特性受隐性矮秆基因控制。“陇矮1号”与“老芒麦”、“和尚头”和“高原602”的F-2代株高分离表明，“陇矮1号”的矮秆特性受2对或2对以上隐性基因控制。此外，超亲分离表明“陇矮1号”的矮秆特性还受到一些微效基因的影响。对各组合回交世代BC-1和BC-2株高分离结果进行X’测验，BCl的矮秆株数与半矮秆株数之比为3：1，而BC。的半矮秆株数与高秆株数之比为1：3。因此，推断“陇矮I号”的矮秆特性受2对主效隐性矮秆基因控制。

青海湖北岸植物群落与环境因子关系的初步研究

依据对青海湖北岸 1 8个群落的样方调查和环境因子原始数据 ,用主分量分析 ( PCA)排序技术和回归模型 ,定量分析湖滨平原植物群落在空间地理上的分布格局 ,以及群落结构特征和环境梯度之间的关系。结果表明 :植物群落的类型分布主要决定于环境中的土壤水分含量及土壤全盐含量。代表植物群落结构特征的生物多样性 ( X1)和生态优势度 ( X2 )分别与环境梯度没有显著的相关性 ,但是 ,这两个指标和第一主分量排序轴 (土壤水分度 ,Y)的二元线性回归关系显著 ,回归模型为 :Y =- 4 .85 + 1 .4 7X1+ 1 0 .71 X2 ( P <0 .0 1 )。