仿射Weyl群(E～)6的a值5的左胞腔

Coxeter群的胞腔是1979年Kazhdan和Lusztig中定义的，这些胞腔理论在代数群的表示理论中发挥了重要的作用。对一些特殊的情况，胞腔的分类已经明确地给出了，例如，对于秩为2的群参见，对于An^-参见，对于a值4的典范型和或参见.本文利用时俭益的运算算法给出了仿射Weyl群E6^-的a值等于5的所有左胞腔。     

Failure of opioids to affect excitation and contraction in isolated ventricular heart muscle

Summary The opioid agonists morphine (selective for -receptors) and ethylketocyclazocine (selective for kappa-receptors), at concentrations evoking strong effects in neuronal structures, did not significantly affect the configuration of the intracellularly recorded action potential and the force of contraction in ventricular heart muscle isolated from guinea pigs, rabbits and man. These results suggest that any changes of heart functions in vivo in response to opioid-like drugs are probably not mediated postsynaptically at the myocardial cell membrane but rather presynaptically, influencing the release of noradrenaline and/or acetylcholine from the nerve terminals.     

The role of repair in radiobiology

Summary Apart from cancer and mutation induction, radiobiological effects on mammals are mostly attributable to cell death, defined as loss of proliferative capacity. Survival curves relate retention of that capacity to radiation dose, and often manifest a quasi-threshold (shoulder). The shoulder is attributable to an initial mechanism of repair (Q-repair) which is gradually depleted as dose increases. Another form of repair, which is not depleted (P-repair), increases the dose required to deliver an average of one lethal event per cell (dose D₀). Neither form of repair can unambiguously be linked with repair of defects in isolated DNA. An important initial lesion may well be disruption of the complex structural relationship between the DNA, nuclear membrane and associated proteins. One form of P-repair may be restoration of that structural relationship.     

Lack of effect of dihydroergotamine on endothelial and smooth muscle cell proliferation and endothelial cell prostanoid production

Summary The most important effect of dihydroergotamine is venoconstriction, but certain metabolic effects and changes in vessel prostanoid activity have also been suggested. In this study endothelial cell production of 6-keto PGF₁ and TxB₂ was quantitated in vitro. No evidence of altered prostanoid production was noted after incubation with dihydroergotamine (exposure ranging from 5×10^–3 to 5×10^–7 g/l). Similarly, no effect of dihydroergotamine on the growth rates of endothelial cells or smooth muscle cells in vitro was documented.     

冠状动脉粥样硬化病变中微量元素的X射线显微分析

本文应用EDAX-9100能谱仪,对家兔冠状动脉粥样硬化病变部位的微量元素进行显微分析,发现Zn/Cu比值大于1,提供了冠心病病因中“Zn/Cu假说”的实验论证。     

In vitro protein synthesis and α amylase activity in F cells from hepatopancreas ofPalaemon serratus (Crustacea; Decapoda)

In crustaceans, all the steps in the assimilation of food take place in the hepatopancreas. To facilitate the study of this organ, a method for the dissociation of cell types was developed. The hepatopancreas of the prawnPalaemon serratus was mechanically dissociated and the cells separated by Percoll density-gradient centrifugation. The E and R cells had similar densities of around 1.05 g/ml. The F cells were separated into two distinct fractions with densities of 1.075 and 1.082 g/ml. The B cells sedimented at a density of 1.12 g/ml. The ratio between the two populations of F cells was found to vary during the intermolt cycle while B cells disappeared after the molt. When the density gradient fractions were incubated with³H-leucine, incorporation was highest in the F cell fractions. Measurements of -amylase activity, indicated that the two populations of F cells may be derived from the same cell type.     

产物分离固相化细胞反应器的设计和数学模型

设计了一种以挥发性产物和非挥发性底物为特征的四相反应器——分离器。在此反应器中,生物催化剂被固定在固体柱填充物上并与含有底物的液相接触,汽相流过柱子而将挥发性产物蒸发迸入汽相。反应器由同方向流的浓缩器和反方向流的分离器两个基本汽——液流部分组成。并建立了吸附的单层细胞稳态群体数学模型和反应器平衡状态模型。     

Molt-induced muscle atrophy decreases the zinc content of the pectoralis of the Giant Canada Goose (Branta canadensis maxima)

Summary During molt-induced atrophy of the pectoralis muscle of the Giant Canada Goose (Branta canadensis maxima), the zinc content of the muscle was significantly reduced (p0.0139), though the concentration of zinc per unit weight of muscle appeared higher (p0.0232). Zinc lost from the muscle during molt could be utilized for growth of the new flight feathers.Acknowledgments. Funds for this study were obtained from an operating grant awarded to J. C. G. by the Natural Sciences and Engineering Research Council of Canada.     

Loss of antibody production accompanied by chromosome loss in a cloned hybrid line secreting antibodies to sheep red blood cells

Summary Somatic cell hybrids between Sp2/O-Ag14 mouse myeloma cells and lymphocytes derived from BALB/c mice hyperimmunized with sheep red blood cells (SRBC) were produced. One hybrid producing IgG₁ antibody to SRBC was selected, cloned twice and subsequently transferred to BALB/c mice. After a number of transfers it was found that the antibody titer in ascitec fluid gradually decreased. Cytogenetic analysis revealed gradual chromosome loss in the hybrid clone, which produced progressively less antibody.     

Selective protection of cells against X-irradiation. Isoproterenol protects only those cells that possesβ-adrenoreceptors

Summary In mixed culture of Chinese hamster fibroblatst, clone 431, and transformed murine L fibroblasts, clone B-82, isoproterenol was found to protect only 431 cells against ionizing radiation. It was shown that 431 cells, in contrast to B-82 cells, possess-adrenoreceptors, and the radioprotective effect of isoproterenol can be realized only if this agent interacts with-adrenoreceptors coupled with the cAMP system. Since malignization often causes the disappearance of-adrenergic and other hormone receptors, the combined culturing and irradiation of the cells studied can be regarded as a model of the growth of malignant cells (B-82) among normal tissue cells (431 cells) under conditions of radiation therapy. A possibility of selective protection against radiation damage of normal tissue cells, with retention of the former radiosensitivity of tumor cells, is discussed.