A STOCHASTIC GROWTH MODEL WITH ENVIRONMENTAL POLLUTION

Pollution is introduced into the utility function and the productive function in this paper.Under appropriate macroeconomic equilibrium conditions, this paper proves that the equilibrium levels of the main economic indexes are uniquely determined by the model parameters. This paper establishes the following alternative theorem： some factors affect the economic growth and the welfare in opposite way.     

不等式约束增长曲线模型中线性预测的可容许性

根据线性预测可容许性的定义,利用矩阵的有关性质,得到了齐次线性预测(非齐次线性预测)在齐次线性预测类(非齐次线性预测类)中是可容许性预测的充分必要条件,推广了以往文献的有关结论.     

胰岛素样生长因子Ⅱ浓度变化与阻塞性睡眠呼吸暂停低通气综合征患者认知功能的相关性

目的 探讨OSAHS患者血清胰岛素样生长因子Ⅱ(IGF-Ⅱ)浓度与其认知功能的关系,揭示OSAHS引起认知功能障碍的可能机制.方法 采用MoCA量表评定28名OSAHS患者及14名健康志愿者认知功能,采用酶联免疫吸附法检测研究对象血清IGF-Ⅱ浓度,分析研究对象血清IGF-Ⅱ浓度与认知功能、夜间低氧及睡眠结构间的关系.结果 OSAHS组血清IGF-Ⅱ浓度显著高于对照组(t=5.587,P=0.000);研究对象MoCA总分与血清IGF-Ⅱ浓度显著负相关(r=-0.483,P=0.001);研究对象血清IGF-Ⅱ浓度与AHI及S1 +S2期睡眠时间长短显著正相关(r分别为0.483、0.549,P分别为0.001、0.000);与LSO、S3+S4期睡眠时间及REM睡眠时间长短显著负相关(r分别为-0.449、-0.612、-0.395,P分别为0.003、0.000、0.010).结论 OSAHS患者血清IGF-Ⅱ浓度高于正常人群,IGF-Ⅱ在OSAHS患者认知功能障碍的发病机制中可能起着重要作用.     

逆境胁迫下植物基因的表达与调控

探讨植物在逆境下的适应机制,综述了植物在逆境下相关基因的表达调控方式,由于植物生活的“不动性”使其不可避免地要受到各种逆境的冲击,经过系统的进化,植物本身能够建立起有效的适应乃至抗性机制。大量的研究认为,逆境胁迫下,植物体内脱落酸（ABA）和水杨酸（SA）的含量会发生明显的变化,从而诱导许多新基因表达以及蛋白质合成,来适应环境的变化。植物对环境的适应可能有两种机制。第一种机制是ABA与SA诱导核糖核酸（mRNA）的合成或使其稳定。第二机制是ABA与SA有引起逆境响应蛋白的积累和翻译调控。     

Crystallographic studies on the binding of coenzyme analogs to D-glyceraldehyde-3-phosphate dehydrogenase fromPalinurus versicolor

In contrast with the coezyme, two coenzyme analogs, ADP-ribose and SNAD, bind non-cooperatively to D-glyceraldehyde-3-phosphate dehydrogenase (GAPDH).Palinurus versicolor (PV) GAPDH complexed with ADP-ribose and SNAD has been crystallized by the method of sitting-drop vapor diffusion. X-ray diffraction data analysis reveals that both crystals belong to the same space group (C2), and have similar cell dimensions: a =152.80 Å,b =100.35 Å, c =128.31 Å,β =110.28° and a =153.41 Å,b =100.51 Å,c =128.44 Å,β =110.48°, respectively. It is estimated that the asymmetric unit in each crystal contains 4 subunits. This is a novel crystal form which is quite different from that previously reported for holoand apo-GAPDH from the same source. The result suggests that the binding of the two coenzyme analogs to GAPDH may lead to some significant conformational changes, which are different from those induced by the coenzyme binding. The self-rotation function indicates that the tetramer of these two GAPDH complexes also has good 222 symmetry. The structural analysis and the comparison with holoand apo-GAPDH may give a clue to the cooperative mechanism of the enzyme.     

扫描电镜及电子能谱对硅酸钙水合晶体生产过程的研究

以扫描电镜-电子能谱为主要研究手段,并辅之以X-射线衍射、透射电镜-电子衍射等结构分析方法,对蒸压条件下硅酸钙水合晶体的生成过程进行了较为系统的研究。结果表明,硅酸钙水合晶体的生成经历了水合C_a~(2+)离子扩散进入圆筛藻孔道中、晶核的形成、晶种的生成、晶体长大等几个主要阶段。并结合不同的反应阶段对制备条件的要求进行了有关的讨论。     

播娘蒿对小麦早期生长的生化他感作用研究

探讨了麦田杂草播娘蒿对小麦早期生长发育的影响。发现播娘蒿种子淋洗物对小麦种子萌发和幼苗初期生长主要表现抑制效应,但淋洗物中的个别成分又有促进效果。证明了播娘蒿与小麦之间有生化他感作用存在,认为生化他感作用是播娘蒿作为麦田杂草影响小麦生长发育的另一种方式。     

三轴应力场中空穴扩张临界值与材料的微观断裂延性

选用一种球化碳钢的轴对称光滑和不同缺口拉伸试样研究了材料在三轴应力场中的宏、微观断裂延性。基于不同应力三轴性水平下空穴扩张与聚合的特性,给出了一个新的材料微观断裂延性表达式。结合空穴扩张的临界尺寸与断口韧窝几何的三维测量结果,证明了在不同的三轴应力水平下,材料微观断裂延性与实测宏观断裂延性之间均有着良好的一致性。从而揭示了材料断裂延性随应力三轴性水平升高而下降的微观机理。     

一些新酰化N—取代唑类化合物的合成

为了筛选具有植物生长调节活性兼具杀菌活性的唑类化合物。合成了9个酰化N-取代的唑类化合物,其中的8个属新化合物尚未见文献报导。     

Involvement of small Ras GTPases and their effectors in chronic renal disease

The mechanisms involved in the development of renal fibrosis are poorly understood. Small Ras GTPases control cell proliferation, differentiation, cellular growth and apoptosis, with cell-specific expression in the kidney. Cytokines, high glucose medium or advanced glycation end-products activate Ras in different renal cells. Increased Ras activation has been found in experimental tubulointerstitial fibrosis. Transforming growth factor-β1 (TGF-β1) and Ras signalling pathways are close related: TGF-β1 overcomes Ras mitogenic effects, and Ras counteracts TGF-β signalling. However, Ras activation is also an intracellular signal transduction point for several molecules (e.g. TGF-β1) involved in kidney damage. Ras isoforms play different roles in regulating extracellular matrix synthesis in fibroblasts and mesangial cells. These data give evidence for a role for Ras in renal fibrosis, but no reviews are available on the role of p21 Ras in this process. Thus, our goal is to review the role of Ras activation and signalling in renal fibrosis. Received 7 June 2007; received after revision 17 September 2007; accepted 1 October 2007