Effect of 15(R)-15-methyl-prostaglandin E2 on iron absorption in the rat

Summary The administration of 15(R)-15-methyl prostaglandin E₂ (15(R)-15-M-PGE₂) in vivo significantly diminished the uptake of⁵⁹Fe into blood, spleen, liver, femur and dried intestine of rats, whereas acetylsalicylic acid (ASA) increased the counts significantly. This effect of ASA was counteracted by 15(R)-15-M-PGE₂. It is suggested that prostaglandins (PGs) might play an important role in inhibiting iron absorption at the intestinal level.This work was supported by grant No.6638 from CONICET (Argentina). The technical assistance of Mrs María E. Castro and Norma Rizzo is gratefully acknowleged.     

Chromosomal effects of adeno-associated virus vector integration.

Adeno-associated virus (AAV) vectors are currently being used in several clinical gene-therapy trials (see the NIH OBA Human Gene Transfer Clinical Trials Database); however, little is known about the chromosomal effects of vector integration. Here we report that integrated vector proviruses are associated with chromosomal deletions and other rearrangements and are frequently located on chromosome 19 (although not at the wildtype AAV integration site).     

三峡钢丝绳卷扬全平衡式垂直升船机机电耦合系统动力学仿真

建立三峡钢丝绳卷扬全平衡式垂直式升船机的双闭环调速电力拖动控制系统的模型和升船机各子结构的动力学模型，并通过刚性子结构法形成了整体动力学模型，运用MATLAB中的SIMULINK模块，将电力拖动控制系统与整体动力学模型耦合，采用Wilson-θ法求解瞬态响,对误载水深为＋20cm，承船厢低点位置上向上启动运动的正常工况进行了仿真分析。     

再生丝素固体的微细结构

研究了蚕丝丝素水溶液经不同方式干燥后，所得到的再生丝素固体的微细结构，以及存放过程中丝素的结构变化，指出经30℃热风干燥或经高于－20℃冷冻干燥后，所得到的丝素固体的结构是无定形和Silk I共存，在室内温度湿度环境中存放后，部分无定形结构转化为Silk I；蚕丝丝素水溶液经－80－－20℃冷冻干燥后，所得到的丝素膜的结构主要是无定形，含少量Silk II，存放过程中部分无定形结构转化为SilkI；室温放所自然形成的丝素凝胶中，丝素的结构是无定形和Silk Ⅱ共存；丝素水溶液表面膜中甘氨酸和丙氨酸的含量较高，表面膜的结构主要是Silk I和Tilk Ⅱ结晶度高。     

Energetic landscape of alpha-lytic protease optimizes longevity through kinetic stability.

During the evolution of proteins the pressure to optimize biological activity is moderated by a need for efficient folding. For most proteins, this is accomplished through spontaneous folding to a thermodynamically stable and active native state. However, in the extracellular bacterial alpha-lytic protease (alphaLP) these two processes have become decoupled. The native state of alphaLP is thermodynamically unstable, and when denatured, requires millennia (t1/2 approximately 1,800 years) to refold. Folding is made possible by an attached folding catalyst, the pro-region, which is degraded on completion of folding, leaving alphaLP trapped in its native state by a large kinetic unfolding barrier (t1/2 approximately 1.2 years). alphaLP faces two very different folding landscapes: one in the presence of the pro-region controlling folding, and one in its absence restricting unfolding. Here we demonstrate that this separation of folding and unfolding pathways has removed constraints placed on the folding of thermodynamically stable proteins, and allowed the evolution of a native state having markedly reduced dynamic fluctuations. This, in turn, has led to a significant extension of the functional lifetime of alphaLP by the optimal suppression of proteolytic sensitivity.     

Quantum Mechanics and Operational Probability Theory

We discuss a generalization of the standard notion of probability space and show that the emerging framework, to be called operational probability theory, can be considered as underlying quantal theories. The proposed framework makes special reference to the convex structure of states and to a family of observables which is wider than the familiar set of random variables: it appears as an alternative to the known algebraic approach to quantum probability.     

高应变率扭转SHB实验技术

介绍自制分离式霍布金生扭杆试验设备；详细推导出按扭转ＳＨＢ方法测量材料的动态剪应力和剪应变关系的基本方程；对软铝进行高应变率试验得到动态剪应力和剪应变关系曲线。     

Comparative study of the karyotypes of two Egyptian species of bats,Taphozous perforatus andTaphozous nudiventris (Chiroptera: Mammalia)

A detailed karyotypic analysis of two Egyptian species of bats,Taphozous perforatus andTaphozous nudiventris, was made on the basis of conventional data and G-band patterns. No detectable karyotypic difference was found between the two species (2n=42, F.N. 64). By comparison of G-band patterns, some differences between the two species were seen in the corresponding autosomal pairs. These results are reported for the first time in Egypt.     

适用于一般提法的埃尔米特插值多项式的差商构造公式

利用差商的非构造性定义建立了适用于一般提法的埃尔米特(Henmite)插值多项式的差商构造公式,并给出了插值余项估计。     

Increased assembly of cytoskeletal proteins associated with the transformation of human liver cells into fibroblast-like cells.

A topoisomerase II inhibitor, novobiocin, and a deacetylase inhibitor, butyrate, synergistically transformed human liver cells into fibroblast-like cells. This morphological change was associated with an increased production of procollagen type III peptide and a simultaneous assembly of actin, tubulin, vimentin and cytokeratin. Novobiocin and butyrate had no marked effect on the phosphorylation state of cytokeratin proteins, but synergistically enhanced [3H]acetate uptake. From these results, it can be speculated that protein acetylation plays an important role in inducing the assembly of cytoskeletal proteins and the morphological transformation of human liver cells.