用BiCMOS工艺实现的阈值神经元电路

提出了一种新型的阈值神经元电路,它采用ＢｉＣＭＯＳ工艺实现,具有结构 “度高,高速快等特点,能很好地实现神经元的基本运算功能,如“非”、“析取”、“Ｗ事取”、等。ＰＳＰＩＣＥ软件仿真证明了该电路的正确性。     

营口经济技术开发区的发展对策研究

在分析了营口经济开发区的建设发展中出现的占地规模偏大,产业结构切入点偏低,配套资金不足,引进项辐射力弱和投资环境有待进一步改善等５个方面问题基础上,重点从加大招商引资工作力度、通过税等金融政策引导产业结构调整、完善规划体系和改善投资环境等４个方面论述了营口经济技术开发区的发展对策,供决策部门参考。     

子宫切除术中宫颈去留探讨

目的：探讨子宫切除术中宫颈去留的利弊,重新评价子宫次全切除术的应用价值。方法：对８１例子宫次全切和６８例全切除两组病人术后性功能、膀胱功能、更年期症状、血脂及血液流变学情况进行对比,并观察残留宫颈情况。结果：两组术后性功能、膀胱功能均下降,以全切组下降更为明显（Ｐ〈０．０１或０．０５）;两组甘油三脂（ＴＧ）、胆固醇（ＣＨＯＬ）、载脂蛋白Ｂ（ＡＰＯＢ）、全血粘度及血浆粘度均高于正常对照组,载脂蛋白Ａ     

关于迹类算子的几个不等式

利用算子的极分解证明无穷维Hilbert空间H上正迹类算子迹的不等式,又对于HH上的正算子矩阵,当主对角线元素L、M的正次幂Lp、 Mp(p＞0)为迹类算子或Hilbert-Schmidt算子时,利用正算子矩阵的某些性质及H.Wayl 的不等式,分别得到迹范数不等式和Hilber-Schmidt范数不等式,从而使作为有限维空间上算子的矩阵或分块矩阵的有关结论得到推广.     

具有不确定性的多态系统可靠性

在对多态系统进行可靠性分析时,由于很难精确地估算元素各个状态的概率,人们常常利用模糊隶属函数及概率区间来表示这些概率。介绍了用模糊及区间模型估算多态系统可靠性的方法,并介绍了元素不确定性重要度的算法。在LevV.Utkin提出的元素不确定性重要度算法基础之上,提出了不确定性重要度的改进算法。改进算法不仅全面考虑了区间概率的不同含义,而且提高了可靠性分析的精度和可信度。     

Identification of a functional transposon insertion in the maize domestication gene tb1

Genetic diversity created by transposable elements is an important source of functional variation upon which selection acts during evolution. Transposable elements are associated with adaptation to temperate climates in Drosophila, a SINE element is associated with the domestication of small dog breeds from the gray wolf and there is evidence that transposable elements were targets of selection during human evolution. Although the list of examples of transposable elements associated with host gene function continues to grow, proof that transposable elements are causative and not just correlated with functional variation is limited. Here we show that a transposable element (Hopscotch) inserted in a regulatory region of the maize domestication gene, teosinte branched1 (tb1), acts as an enhancer of gene expression and partially explains the increased apical dominance in maize compared to its progenitor, teosinte. Molecular dating indicates that the Hopscotch insertion predates maize domestication by at least 10,000 years, indicating that selection acted on standing variation rather than new mutation.     

重组IL-5质粒pVAX1-mIL-5增强卵透明带DNA避孕疫苗黏膜免疫效能

目的:探讨利用白细胞介素5作为DNA疫苗佐剂增强黏膜免疫反应,提高卵透明带DNA避孕疫苗抗生育效能的可行性。方法:用pVAX1-m IL-5和卵透明带避孕疫苗pVAX1-pZP3α壳聚糖纳米微粒口服免疫雌性小鼠,共设3组,每组6只。A组单独用50μg pVAX1-pZP3α免疫;B组用疫苗加等量的pVAX1-m IL-5质粒为佐剂共免疫;C组为空白对照组。每组动物接受3次免疫(第0、3、6周)。采用ELISA法检测小鼠血清及阴道冲洗液中抗pZP3 IgA抗体。第10周雌雄交配,统计雌鼠怀孕情况;第16周取双侧卵巢作石蜡连续切片,光镜观察卵巢病理学变化。结果:B组全部小鼠血清抗体呈阳性反应,A组只有3只小鼠血清抗体呈阳性反应,且B组小鼠的抗体滴度水平均高于A组小鼠;抗生育率B组小鼠为100%,A组小鼠为50%,C组小鼠为0%,2检验分析结果表明各组间的差异有统计学意义,抗生育效能与交配时抗pZP3 IgA抗体的强度有关;卵巢切片的组织病理学观察结果表明,有抗生育效能的小鼠卵巢组织可观察到各级形态正常的卵泡,无淋巴细胞浸润,与对照组及无抗生育效能的小鼠卵巢结构无差异。结论:利用重组质粒pVAX1-m IL-5与卵...     

Genome-wide association scan of tag SNPs identifies a susceptibility locus for lung cancer at 15q25.1

To identify risk variants for lung cancer, we conducted a multistage genome-wide association study. In the discovery phase, we analyzed 315,450 tagging SNPs in 1,154 current and former (ever) smoking cases of European ancestry and 1,137 frequency-matched, ever-smoking controls from Houston, Texas. For replication, we evaluated the ten SNPs most significantly associated with lung cancer in an additional 711 cases and 632 controls from Texas and 2,013 cases and 3,062 controls from the UK. Two SNPs, rs1051730 and rs8034191, mapping to a region of strong linkage disequilibrium within 15q25.1 containing PSMA4 and the nicotinic acetylcholine receptor subunit genes CHRNA3 and CHRNA5, were significantly associated with risk in both replication sets. Combined analysis yielded odds ratios of 1.32 (P < 1 x 10(-17)) for both SNPs. Haplotype analysis was consistent with there being a single risk variant in this region. We conclude that variation in a region of 15q25.1 containing nicotinic acetylcholine receptors genes contributes to lung cancer risk.     

一种基于噪声模型的TCP有效带宽估计方法研究

准确的带宽估计和网络建模对于网络拥塞控制算法的设计具有重要的意义.采用通信系统加性噪声分析方法和信道容量理论,将TCP链路背景流量的影响等效为加性噪声,提出建立了一种基于等效噪声的链路模型和带宽估计算法.该模型不同于传统带宽估计对采样值直接进行滤波处理来得到估计带宽,而是利用网络流量的随机过程特性采用统计方法进行有效带宽估算,所得到的估计带宽有界并且具有良好的收敛性和准确性.理论分析和仿真结果表明了该模型和算法是正确的.     

试论加强图书馆服务文化建设

介绍了图书馆服务文化的内涵,阐明了加强图书馆服务文化建设的必要性,探讨了加强图书馆服务文化建设的措施。