香港室内氡水平及其与建筑物表面氡析出率的关系

本文报导用活性炭盒吸附方法对香港室内氡浓度的测量结果及其浓度分布规律。对室内氡浓度与建筑物表面氡析出率的关系进行了分析研究。证实室内空气中的氡主要来源于建材中的镭,而氡浓度水平只决定于室内建筑物表面氡的析出率及通风状况。     

Ultrastructural changes in the dorsal root ganglia evoked by thalidomide in rabbits.

Administration of the teratogenic drug thalidomide to pregnant does produces ultrastructural changes in foetal ganglion cells, Schwann cells and axons in the posterior root ganglia corresponding to forelimb segments deformed by the orug. Ultrastructural changes in ganglia appear on the 13th day of gestation, i.e., preceding the appearance of limb malformation.     

大鹏湾沉积物重金属污染的初步研究

用电感耦合等离子焰光谱技术测定大鹏湾４个采样站位沉积物岩芯中Ｐｂ，Ｍｎ，Ｎｉ，Ｃｒ，Ｃｄ和Ｆｅ，Ｍｇ，Ｚｎ，Ｃｕ，Ｃｏ共１０种重金属元素的浓度－深度关系，并根据相应的沉积速率分析了该海域的污染史．     

The pulmonary excretion of14CO2 in patients with ileal resection,Crohn's disease and control subjects following administration of glycine-1-14C

Zusammenfassung Mittels Cholinglycin-¹⁴C-Atemtest für eine bakterielle Konjugation im Darm wird gezeigt, dass der Glycinmetabolismus zwischen Normalpersonen und solchen mit Ileumresektion und Morbus Crohn unterschiedlich ist.

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Acknowledgments. We wish to express our thanks to MissBarbara O. Brown for writing the computer programme, to Mr.A. D. McLaren who gave advice on statistics and to Mrs.Gail Jamieson for her help in the collection of specimens.     

LTRPC7 is a Mg.ATP-regulated divalent cation channel required for cell viability

The molecular mechanisms that regulate basal or background entry of divalent cations into mammalian cells are poorly understood. Here we describe the cloning and functional characterization of a Ca2+- and Mg2+-permeable divalent cation channel, LTRPC7 (nomenclature compatible with that proposed in ref. 1), a new member of the LTRPC family of putative ion channels. Targeted deletion of LTRPC7 in DT-40 B cells was lethal, indicating that LTRPC7 has a fundamental and nonredundant role in cellular physiology. Electrophysiological analysis of HEK-293 cells overexpressing recombinant LTRPC7 showed large currents regulated by millimolar levels of intracellular Mg.ATP and Mg.GTP with the permeation properties of a voltage-independent divalent cation influx pathway. Analysis of several cultured cell types demonstrated small magnesium-nucleotide-regulated metal ion currents (MagNuM) with regulation and permeation properties essentially identical to the large currents observed in cells expressing recombinant LTRPC7. Our data indicate that LTRPC7, by virtue of its sensitivity to physiological Mg.ATP levels, may be involved in a fundamental process that adjusts plasma membrane divalent cation fluxes according to the metabolic state of the cell.     

Flora of the Lower Cretaceous Cedar Mountain Formation of Utah and Colorado, part I. Paraphyllanthoxylon utahense

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Paraphyllanthoxylon utahense, sp. nov., is described from the Cedar Mountain Formation and compared with similar fossil and modern woods. Fossil angiosperm woods from the Early Cretaceous are of great interest because very few have been reported from strata of this age. This species demonstrates that the angiosperms had developed many of their modern characteristics by Early Cretaceous time.