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R. Mousseau  J. Bourgie 《CMAJ》1977,117(3):252-254
In 40 patients percutaneous transhepatic cholangiography was performed by means of the "skinny" Chiba needle. The intrahepatic bile ducts were visualized in 100% of the patients with dilated ducts and in 67% of those with ducts of normal calibre. The results compare to those in the literature and demonstrate the usefulness as well as the reduced morbidity of this new procedure. Therefore nonvisualization of the intrahepatic bile ducts by this method signifies that the ducts are not dilated.  相似文献   

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Ventricular perfusion, push-pull cannulae at the caudate level and cortical superfusion were used in "encéphale isolé" cats in order to estimate endogenous 5-HT release. The amine was measured using the radioenzymatic assay. These different methods are described and compared. Technical aspects and advantages of cortical superfusion under physiological conditions are discussed.  相似文献   

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The first step of male differentiation is the testis determination which is genetically controled. The key role of SRY gene is now established. However, a number of clinical and genetic data favoured the role of other genes taking place upstream or downstream SRY. Most of 46, XX males possess a translocated SRY gene and thus develop testis, but SRY gene is not found in 10% of such patients. Likewise, the molecular study of 46, XY females participated in the identification of SRY as testis determining factor, but 80% of XY gonadal dysgenesis are not explained by an abnormality of SRY gene. Several clinical situations permitted to suspect the role of autosomal (chromosome 1, 9, 10 17 …) and X chromosome loci in the pathology of sex determination. Some recent works concern, in particular, the testis determining factor of the X chromosome (TDF-X) that could act as a repressor of the testis differentiation. In conclusion, molecular mechanisms of sexual determination appear to be much complex, involving probably several genes in a pathway that remain to be elucidated.  相似文献   

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Dr. W. F. Wassink 《Genetica》1935,17(1-2):103-144
Sans résumé  相似文献   

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H. A. Guénin 《Genetica》1951,25(1):157-182
Sans résumé Avec 81 figures dans le texte  相似文献   

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The holarctic subfamily Melitaeinae of Nymphalid butterflies (old genus Melitaea Hbn.) has been split into various genera by morphological systematics, but this division has been debated. This work presents the results of a preliminary survey of European taxa using two types of molecular criteria: analysis of enzyme variation by electrophoresis (19 loci) and sequencing of a mtDNA fragment (ND1 gene). The information provided by both kinds of markers are largely congruent. The division of the subfamily into two monophyletic lines corresponding to the genera Euphyryas s. 1. and Melitaea s. l. is validated. The subsequent division of the former genus into two units, Eurodryas and Hypodryas is also confirmed by molecular criteria. Inside rhe old genus Melitaea, a monophyletic assemblage, corresponding to the ‘Mellicta group’ is disclosed, but the phylogeny of the other species of the group is confused. Uniting them in a ‘Didymaeformia group’ or in a genus Melitaea s. str. risks rhe generation of a paraphyletic assemblage. It remains to be determined whether or not these results are due to insufficient resolution, or whether they reflecr a real evolutionary pattern  相似文献   

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Selective, double irradiation allows the assignment of most 13C-n.m.r. signals in a series of per-O-acetyl disaccharides composed of two D-glucose residues linked α-(1→3), β-(1→3), α-(1→4), β-(1→4), α-(1→6), β-(1→6), and α,α-(1→1). The main influences that affect the chemical shifts are discussed and the spectra of β-cellobiose octaacetate and β-maltose octaacetate are compared to those of cellulose and amylose triacetate, respectively, to show the possibilities and limitations of a disaccharide model for the interpretation of the 13C-spectrum of a polymer.  相似文献   

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Gilbert Long 《Plant Ecology》1969,18(1-6):44-63
Résumé Après avoir indiqué les objectifs et les concepts généraux de la cartographie biogéographique intégrée de la végétation et de son écologie, l'auteur expose, avec plus de détails, les conceptions de forme dans l'expression cartographique, ainsi que les conceptions sur le contenu scientifique des cartes biogéographiques.A ce propos, il décrit un modèle général de la perception des faits et de leurs relations réciproques au'il désigne par l'expression: pyramide de perception. Ce modèle comprend 5 niveaux, des petites aux très grandes échelles. Une application à l'écologie végétale et à la phytogégraphie est développée. De nouveaux types de cartes sont décrits (carte de l'occupation des terres, cartes phyto-écologiques).
Summary The author, first of all, shows the objectives and the main concepts of the biogeographical integrated cartography of the vegetation and of its ecology, he exposes after that, in a more circumstantial way, the conception of the form in the cartographical expression as well as the conceptions bearing on the scientific content of biogeographical maps.In this connection he describes a general model of the perception of facts and of their reciprocal relations, he terms this model: pyramid of perception. This latter comprises 5 levels from the small to the largest scales. An application to plant ecology and to plant geography is developed. New map types (certain forms of land-use maps, phytoecological maps) are described.

Zusammenfassung Einleitend bespricht der Verfasser das Ziel und die allgemeinen Begriffe der integrierten biogeographischen Vegetationskartierung und deren Ökologie. Dann behandelt er eingehend die Formenbegriffe in der kartographischen Darstellung, sowie die den wissen-schaftlichen Inhalt der biogcographischen Karten betreffenden Begriffe.In dieser Beziehung beschreibt er ein allgemeines Modell der gegenseitigen Beziehungen und der Wahrnehmung der Tatsachen. Das Modell wird durch den Ausdruck Wahrnehmungspyramide bezeichnet und besteht aus 5 Stufen, von den kleinen bis zu den großen Maßstäben. Eine Anwendung zur Vegetationsökologie und zur Phytogeographie wird erörtert. Es werden neue Kartentype beschrieben (einige Formen von Bodennutzungskarten, phytoökologische Karten).
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