Lactacystin-induced apoptosis of cultured mouse cortical neurons is associated with accumulation of PTEN in the detergent-resistant membrane fraction

The tumor suppressor function of PTEN is attributed to its phospholipid phosphatase activity that dephosphorylates the plasma membrane phosphatidylinositol-(3,4,5)-triphosphate [PtdIns(3,4,5)P₃]. Implicit in this notion is that PTEN needs to be targeted to the plasma membrane to dephosphorylate PtdIns(3,4,5)P₃. However, the recruitment of PTEN to the plasma membrane is not fully understood. Here, we demonstrate PTEN accumulation in the detergent-insoluble fraction of neuronal cells in response to treatment by the proteasome inhibitor lactacystin. First, lactacystin induces apoptosis and the activation of caspase-3 in cultured cortical neurons. Second, PTEN undergoes proteolysis to form a truncated 50-kDa form that lacks parts of its C-terminal tail. Third, the truncated PTEN is stably associated with the detergent-insoluble fraction in which the plasma membrane marker protein flotillin-1 resides. Taken together, our results suggest that truncation and accumulation of PTEN to the detergent-insoluble membrane fraction are two events associated with the apoptotic signals of the proteasome inhibitor in cortical neurons.Received 24 March 2004; received after revision 26 May 2004; accepted 5 June 2004     

潜土旋耕试验研究(1)─正、逆转单刀旋耕对比试验

通过正、逆转单刀旋耕对比试验，分析了旅耕过程中不同的旋耕方式对于旋耕功耗以及各种负荷的影响，并提出了在一定耕渠条件下的旋耕方式．     

用低值鱼类制造冷冻鱼糜项目的设计与评估

本文设计了冷冻鱼糜制造工艺,并用投资效果的动态分析法评估了以低值经济鱼类制造冷冻鱼糜的项目,揭示了一条投资低、经济和社会效益均好的综合利用低值经济鱼类的途径。     

α—AlO（OH）水硬铝石晶体简振模的研究

本文利用群表示理论研究α—AlO(OH)水硬铝石晶体可约表示特征标并找出声学模和光学模变换的不可约表示.根据投影算子技术确定了简振模,我们分析了所得结果并给出了合理的解释.     

一种基于边缘知识的雷达图像匹配定位算法

针对低信噪比实孔径雷达图像的特点，选用适于提取多尺度稳定边缘的Ｃａｎｎｙ算子，结合具有视觉非线性的门限准则、Ｎｅｖａｔｉａ细化和跟踪准则及Ｈｏｕｇｈ变换，提取可靠稳定的边缘特征描述，根据可见光参考图提取与ＳＡＲ图像共性的稳定边缘特征的知识以及稳定边缘的知识描述，提出了一种基于边缘知识的雷达图像与可见光图像匹配定位算法．实验结果表明，该算法能可靠地完成雷达图像的匹配定位．     

海上小目标检测的视知觉方法

针对海上小目标检测问题，提出采用基于视觉非线性的图像分割方法，同时结合最佳分割区域自动调整算法，获得海上小目标的优良分割结果，并利用目标背景间存在较强反差这一先验知识，从分割所得二值图像中确定真实目标．算法中同时考虑了对亮、暗目标的处理，因而对目标的灰度变化不敏感．大量海上小目标检测的实验结果证实了本方法的有效性．     

Laser step-heating ^40Ar/^39Ar dating on young volcanic rocks

An attempt was made to use CO_2 laser step-heating method to date the late Pleistocene basaltic groundmass (DF-2) from Tengchong volcanic field. Among the fourteen heating steps, ten define a good inverse isochron (MSWD = 1.4) with an age of 32.2 ± 7.1 ka (2 σ).The inverse isochron also shows that the initial argon isotopic ratio is 297.1±2.0 (2σ) which is the same as the atmospheric argon at the 2σ error level. Study indicates that it is a useful means to date young volcanic groundmass with low K content by using CO_2 laser step-heating ~(40)Ar/~(39)Ar method.     

基于虚拟现实技术的工业设计研究概述

文章介绍了工业设计的基本概念,分析了虚拟产品设计的基本过程,着重研究了虚拟现实技术在工业设计不同阶段的应用情况,为不断提供工业设计水平提供了一定的研究参考。     

韩国伞滑刃属线虫的形态和分子特征

以锥尾伞滑刃线虫（Bursaphelenchus conicaudatus）作为对照,在韩国不同地域和寄主中采集了15个松材线虫分离物、3 个拟松材线虫的分离物及5个未鉴定的该属的分离物,并对其进行了ITS 和 D2D3 rDNA序列分析。以单条雌线虫的DNA为模板,ITS 和 D2D3 区由PCR仪扩增并克隆其序列。结果表明,所有松材线虫的ITS 和 D2D3 区序列相同,没有种内变异。然而2个采自黑松和红松的拟松材线虫分离物的基因型分别是亚洲型和欧洲型。5个未鉴定线虫的数据表明,它们分别接近B. tusciae、B. lini、B. thailandae、B. doui和 B. hylobianum,该结果同时被形态学结果所支持。利用5种酶（Hinf I、Alu I、Msp I、Hae III、Rsa）,PCR产物克隆并测序的数据也可以区分不同种和基因型。