半素环上若当(α,α)-导子的注记

证明了2-非扰半素环上的若当(α,α)-导子是(α,α)-导子.     

半素环上若当（α，α）-导子的注记

证明了2-非扰半素环上的若当（α,α）-导子是（α,α）-导子．     

Effect of cultivating conditions on α-galactosidase production by a novel Aspergillus foetidus ZU-G1 strain in solid-state fermentation

The work is intended to achieve optimum culture conditions of α-galactosidase production by a mutant strain Aspergillusfoetidus ZU-G1 in solid-state fermentation (SSF). Certain fermentation parameters involving moisture content, incubation temperature, cultivation period of seed, inoculum volume, initial pH value, layers of pledget, load size of medium and period of cultivation were investigated separately. The optimal cultivating conditions of α-galactosidase production in SSF were 60%initial moisture of medium, 28 ℃ incubation temperature, 18 h cultivation period of seed, 10% inoculum volume, 5.0～6.0 initial pH of medium, 6 layers of pledget and 10 g dry matter loadage. Under the optimized cultivation conditions, the maximum α-galactosidase production was 2037.51 U/g dry matter near the 144th hour of fermentation.     

从α－粒子的发现到散射实验——纪念α粒子散射实验100周年

本文结合物理学史料,对卢瑟福的α粒子散射实验在原子物理和核物理的发展中所作的伟大贡献作简要介绍。     

Effect of Static Magnetic Field on α-Amylase Activity and Enzymatic Reaction

The effect of magnetic field on α-amylase was studied. Under the experimental conditions, α-amylase solution was treated by 0.15 T, 0.30 T and 0.45 T static magnetic fields for a known period of time, then the activ-ity, kinetic parameters, and the secondary conformation were investigated. The results showed that there was a con-siderable effect of the magnetic exposure on the α-amylase. The activity was increased by 27%, 34.1%, 37.8% compared with the control. It was also found that both kinetic parameters Km and Vm could be decreased due to the increasing magnetic field, Km decreased from 2.20×102 to 0.87×102, whereas Vm decreased from 2.0×103 g/min to 1.1×103g/min. At the same time, there were some irregular changes in α-amylase secondary conformation.     

多值逻辑系统Hα中的重言式分类定理

系统Hα是一个带有参数的系统,将参数α赋予不同的值,将会得到不同的多值逻辑系统．借助子代数理论,研究了多值逻辑系统Hα中的重言式分类定理,为系统Hα的进一步研究奠定了基础．     

单叶函数若干子类的Hankel行列式H 2(3)

对α阶星象函数S*(α)、α阶凸函数K(α)和导数的实部大于α的函数类R(α)的二阶Hankel行列式H_2(3)分别进行研究.利用已知的正实部函数类的系数估计来估计出给定的3个函数类的H_2(3)模的上界.其中,R(α)对应H_2(3)模的上界是最佳的.当系数a_2=0时,得到S*(α)和K(α)对应H_2(3)模的最佳上界.     

R~n上局部可积函数一个性质的推广

文［１］中王士林教授给出了一个有用的引理，本文将该引理进行推广，利用该引理为研究Ｌｉｔｌｅｗｏｏｄ—ｐａｌｅｙｇλ—函数和Ｌｕｓｉｎ面积积分函数提供了有力工具     

弱α-Armendariz环

引入了弱α-Armendariz环的概念,使用通常的环论方法研究了它的一些性质.证明了弱α-Armendariz环的有限直积,n×n上三角矩阵环及平凡扩张是弱ā-Armendariz环,给出了环R是弱α-Armendariz环的一些充要条件.     

Parthenolide inhibits proliferation of vascular smooth muscle cells through induction of G0/G1 phase cell cycle arrest

Objective: This study is to determine the effect of the natural product parthenolide, a sesquiterpene lactone isolated from extracts of the herb Tanacetum parthenium, on the proliferation of vascular smooth muscle cells (VSMCs). Methods: Rat aortic VSMCs were isolated and cultured in vitro, and treated with different concentrations of parthenolide (10, 20 and 30 μmol/L).[3H]thymidine incorporation was used as an index of cell proliferation. Cell cycle progression and distribution were determined by flow cytometric analysis. Furthermore, the expression of several regulatory proteins relevant to VSMC proliferation including IκBα, cyclooxygenase-2 (Cox-2), p21, and p27 was examined to investigate the potential molecular mechanism. Results:Treatment with parthenolide significantly decreased the [3H]thymidine incorporation into DNA by 30%～56% relative to control values in a dose-dependent manner (P＜0.05). Addition of parthenolide also increased cell population at G0/G1 phase by 19.2%～65.7% (P＜0.05) and decreased cell population at S phase by 50.7%～84.8% (P＜0.05), which is consistent with its stimulatory effects on p21 and p27. In addition, parthenolide also increased IκBα expression and reduced Cox-2 expression in a time-dependent manner. Conclusion: Our results show that parthenolide significantly inhibits the VSMC proliferation by inducing G0/G1 cell cycle arrest. IκBα and Cox-2 are likely involved in such inhibitory effect of parthenolide on VSMC proliferation. These findings warrant further investigation on potential therapeutic implications of parthenolide on VSMC proliferation in vivo.     

Convexity-preserving interpolation of trigonometric polynomial curves with a shape parameter

In computer aided geometric design(CAGD) ,it is often needed to produce a convexity-preserving interpolating curve according to the given planar data points. However,most existing pertinent methods cannot generate convexity-preserving in-terpolating transcendental curves;even constructing convexity-preserving interpolating polynomial curves,it is required to solve a system of equations or recur to a complicated iterative process. The method developed in this paper overcomes the above draw-backs. The basic idea is:first to construct a kind of trigonometric polynomial curves with a shape parameter,and interpolating trigonometric polynomial parametric curves with C2(or G1) continuity can be automatically generated without having to solve any system of equations or do any iterative computation. Then,the convexity of the constructed curves can be guaranteed by the appropriate value of the shape parameter. Performing the method is easy and fast,and the curvature distribution of the resulting interpolating curves is always well-proportioned. Several numerical examples are shown to substantiate that our algorithm is not only correct but also usable.     

Basic fibroblast growth factor alleviates brain injury following global ischemia reperfusion in rabbits

The aim of this study was to explore the protective effect of basic fibroblast growth factor (bFGF) on brain injury following global ischemia reperfusion and its mechanisms. Brain injury following global ischemia was induced by four vessels occlusion and systemic hypotension. Twenty-four rabbits were randomized into three groups: group A, only dissection of vessels; group B, intravenous infusion of normal saline after reperfusion for 6 h; group C, 30 μg/kg bFGF injected intravenously at the onset of reperfusion, then infused with 10 μg/(kg·h) for 6 h. Serum neuron specific enolase (NSE), S-100B, tumor necrosis factor-α(TNF-α), interleukin-1 (IL-1), interleukin-8 (IL-8) were measured before ischemia, 30 min after ischemia, 0.5, 1, 3, 6 h after reperfusion. Brain water content was determined and cerebral histopathological damages were compared. NSE and S-100B were increased 1 h after reperfusion and reached their peaks 6 h after reperfusion, but were much higher in group B than those in group C 3, 6 h after reperfusion. In groups B and C, TNF-a was increased after ischemia and IL-1 and IL-8 were increased significantly 0.5 h after reperfusion, then reached their peaks 6 h, 3 h, 6 h after reperfusion respectively. TNF-a and IL-8 at the time points of 1 h and 3 h and IL-1 at 3 h and 6 h in group C were correspondingly lower than those in group B. These indices in group A were nearly unchanged. There were less severe cerebral histopathological damages in group C compared with group B, but no difference in brain water content. It could be concluded that bFGF alleviates brain injury following global ischemia and reperfusion by down-regulating expression of inflammatory factors and inhibiting their activities.     

半严格α-预不变凸函数的一些性质

文章讨论了一类新的广义凸函数:半严格α-预不变凸函数,并得到了它的一些性质。这些性质包括在一定条件下判别半严格α-预不变凸函数的两个必要条件以及复合函数的半严格α-预不变凸性,最后还讨论了半严格-预不变凸函数在数学规划中的两个重要应用。     

借助Maple讨论y=x~αsin1/x(α∈R)的连续性

借助Maple软件,对yn=xnsin1/x(n=0,1,2,3)进行了分类比较、讨论,给出它们在x=0处及附近的部分分析性质的证明;作出十分直观的示意图,消除以前只能凭空想象的缺陷;并对y=xαsin1/x和y=xαcos1/x(α∈R)作了推广、引申:结合实际问题进行了应用讨论.     

不对称相转移催化合成α-氨基酸的方法研究

本文综述了近五年来α-氨基酸不对称合成的研究进展,纵观几年的文献发现,α-氨基酸的合成的发展是随着相转移催化剂的发展而发展起来的,其主要以金属配合物、季铵盐、金鸡纳生物碱衍生物的催化剂为代表,本文通过不同的催化剂对α-氨基酸的合成做一简单介绍。     

Lipschitz-α对偶算子及对偶空间

引入了Lipschitz-α对偶算子及距离空间(D,d)的Lipschitz-α对偶空间,证明了T*L-α为D*L-α上的有界线性算子,并讨论了Lipschitz-α对偶算子的若干性质.     

催化动力学光度法测定α,α′—联吡啶

本文研究了在ＨＡｃ－ ＮａＡｃ 缓冲溶液中,微量α,α′—联吡啶加速抗坏血酸还原偶氮胂（Ⅲ）褪色的指示反应及其动力学条件,建立了动力学光度法测定微量α,α′—联吡啶的方法。该方法的线性范围为８ ×１０－ ８ ～４ ．８ ×１０－７ｍｏｌ／２５ｍｌ,检测限为４．５１３ ×１０－ ８ｍｏｌ／２５ｍｌ。     

用矩阵刻画模的同调性质

用环R上的矩阵研究了R-模的一些同调性质.对于任给的基数α,β以及β×α行有限矩阵A,证明了Ext1R (R(α)/R(β)A,M)=0当且仅当Mα/rMα(R(β)A) HomR(R(β)A,M) 当且仅当rMβlR(β)(A)=Amα,进一步推广了(m,n)-内射性的概念,并从矩阵的零化子,同态的分解和同调群等角度给出(α,β)-平坦性的等价刻画,从而使(m,n)-平坦模,f-投射模和n-投射模统一到(α,β)-平坦模的概念之下.此外还给出了左R-ML模的一个刻画和R(β)A是左R-ML模的等价条件,从而把凝聚环、 (m,n)-凝聚环、π-凝聚环等概念统一到(α,β)-凝聚环的概念之下.