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1.
Les Sphériques ont été écrites par Ménélaos sous la forme dun traité dapparence purement mathématique. Cependant, la matière qui y est développée dans les deuxième et troisième livres est étroitement liée à des problèmes rencontrés en astronomie: calcul des coordonnées équatoriales du Soleil, établissement de tables dascensions, étude du mouvement du Soleil dans la sphère oblique, levers simultanés. Ce lien, qui demeure implicite dans le texte, a été mis en évidence par deux mathématiciens et astronomes arabo-musulmans, qui ont exposé la signification astronomique de certains théorèmes des Sphériques. Nous présenterons, commenterons et complèterons cette explicitation en classant les théorèmes concernés en trois groupes: sens de variation de certaines grandeurs sur la sphère, propositions de trigonométrie sphérique et applications, sens de variation de rapports entre certaines grandeurs sur la sphère. The Spherics were written by Menelaos in the form of a purely mathematical treatise. However, the material developed in the second and third book is closely linked to problems met in astronomy: computation of equatorial coordinates of the Sun, setting up of rising-time tables, study of the motion of the Sun in the sphaera obliqua, simultaneous risings. This link, which remains implicit in the text, was clearly displayed by two arabo-islamic mathematicians and astronomers, who expounded the astronomical meaning of some theorems of the Spherics. We describe, comment and complement their explanations, by classifying the implications of the theorems in three groups: direction of variation of some quantities on the sphere, spherical trigonometry and applications, direction of variation of ratios of some quantities on the sphere.Presenté par M. Folkerts(Manuscrit reçu le 23 octobre 2002) Publié en ligne le 5 février 2004An erratum to this article can be found at  相似文献   

2.
Summary The role of interferon (IFN) in controlling chronic infections ofListeria monocytogenes (Listeria) was studied in athymic C57BL/6nu/nu mice, and by treating thymectomized C57BL/6 +/+ mice with monoclonal rat CD4 and CD8-specific monoclonal antibodies (Mab). Mice treated with a combination of the two T cell subset antibodies were similar to athymic, nude mice in being able to contol Listeria infection, keeping the titers below 3–5 log10 bacteria per organ, but they could not eliminate them completely. Treatment with antibodies to IFN of nude or CD4+ + CD8+-T cell-depleted mice suffering from chronic Listeria infection caused a marked increase of Listeria titers, in liver and spleen. This result implies a role of IFN in maintaining anti-Listeria resistance in mice lacking mature T cells.  相似文献   

3.
Zusammenfassung Die Synthese von (—)-1(7)-Tetrahydrocannabinol (THC) auf (—)-1(6) wird beschrieben. Das Hauptprodukt der oxidativen Zerstörung von (—)-1-THC ist Cannabinol. Beschleunigte Versuche der Luftoxidation von (—)-1-THC und (—)-1(6)-THC haben gezeigt, dass das letztere beständiger ist. Dieser Unterschied kann mit der Reaktivität des C3-benzylisch-allylischen Wasserstoffes in (—)-1-THC erklärt werden.  相似文献   

4.
Summary The enzymatic hydrolysis of N-phenylacetyl derivatives of racemic amino-acids having the chiral centre removed from the usual -position is examined. The reaction is found to have different degrees of stereoselectivity. In the case of -amino-acids and of -aminovaleric acid, both enantiomers can be obtained in good yields and high optical purity. S-directed stereochemical preference was found for all the substrates examined.  相似文献   

5.
Zusammenfassung Zwei neue Chromosomen (2n=36 und 37; früher 38, 39 und 40) wurden in der malayischen SpitzmausSuncus murinus gefunden und als numerische Variationen der Robertsonschen Translokation zugeschrieben. Es wird angenommen, dass es sich um zwei Arten von Translokation» handelt die metazentrisch mitwirkten und woraus die Produktion 9 karyotypischer Klassen resultiert.  相似文献   

6.
Summary The effects of acute intravenous administration of synthetic DSIP, 25 nmoles/kg b. wt, on disturbed human sleep were tested in 6 middle-aged chronic insomniacs. The results were: longer sleep duration and a higher quality of sleep with fewer interruptions; slightly more REM-sleep, but no day-time sedation or other side effects though the sleep enhancing capacity was seen for up to 6 h of night sleep. Sleep-promoting effects occurred only in the second hour after injection, in the first hour a slight arousing effect was indicated. The study corroborates the findings of previous investigations in healthy subjects and shows that DSIP has a normalizing influence on human sleep regulation. Editorial foreword. Experimental work in the field of sleep research was energetically furthered by the efforts of the eminent physiologist and Nobel Laureate Walter Rudolf Hess, in whose memory the Zürich lecture series The Principle of Order in Physiology was held on March 14th, 1981. The following report documents the first controlled clinical experiments testing the delta-sleep-inducing-peptide on chronic sufferers of insomnia. In order that these findings may reach as wide a readership as possible, we are placing this brief but important report under the heading Generalia.In honor of W. R. Hess, to mark the centenary of his birth.  相似文献   

7.
Zusammenfassung Aus den zerkleinerten Blättern vonCyanotis vaga (Commelinaceae) wurde durch Benzolextraktion und Chromatographie mit Silikagel eine neue Substanz isoliert: C27H44O7 (Sp. 146–151), die nach den spektrometrischen Daten (IR, NMR, UV, MS) mit dem Insektenhormon Ecdysteron stereoisomer ist.

Dedicated to Prof. Dr. R. Tschesche, Organisch-Chemisches Institut, Universität Bonn (Germany) on the occasion of his 65th birthday, for the invaluable help and inspiration he has given us.  相似文献   

8.
Summary Epidermal growth factor stimulated both [3H]thymidine uptake and proliferation of rat AH66 hepatoma cells. However, the increase in cell number was not accompanied by a proportional increase in the levels of -fetoprotein of the culture media. The effects of EGF on the cell proliferation were antagonized by N6, O2-dibutyryl cAMP.  相似文献   

9.
Zusammenfassung Die Behandlung von 8-5-Anhydro-8-mercapto-2-o-mesylguanosin mit (1,2 Äquivalent) Tributylammonium-uridylat in siedendem DMF lieferte das Dinucleosidphosphat Uridyl-(3-5)-8-mercapto-2-o-mesylguanosin. Weitere Behandlung mit Raney Ni führte zum Uridyl-(3-5)-2-o-mesylguanosin.  相似文献   

10.
Riassunto È stata studiata con metodi istochimici la distribuzione della 5-3-idrossisteroide deidrogenasi ( 5-3-HSDH) e delle 17-idrossisteroide deidrogenasi (17-HSDH), DPN- e TPN-dipendenti, nell'ovario di gallina ovulante. Mentre la 5-3-HSDH è presente in tutti i tessuti a secrezione steroide dell'ovario, la 17-HSDH è localizzata solo nelle cellule della granulosa.  相似文献   

11.
Summary 3, 16-diacetoxy-5-pregnane-20-one and the analogue pregn-5-ene derivative have been converted into (22R, 25R)-22, 26-imino-5-cholestane-3, 16-diol. The configuration at C-22 and C-25 was determined by transformation into the known (22R, 25R)-5-solanidane-3-one. Application of the Ruschig method led to (25R)-22,26-imino-5-cholest-22(N)-ene-3, 16-diol.

Solanum-Alkaloide. XVI. Mitteilung. — XV. Mitteilung:K. Schreiber undH. Ripperger, Tetrahedron Letters Nr.27, 9 (1960).  相似文献   

12.
Zusammenfassung Ecdyson, ein Häutungshormon der Insekten, wurde ausgehend von Ergosterin in 14 Stufen synthetisiert. Wesentliche Zwischenprodukte waren (20S)-2, 3-Diacetoxy-20-formyl-5-pregn-7-en-6-on und (22R)-2, 3-Diacetoxy-14, 22-dihydroxy-25-(tetrahydropyran-2-yloxy)-5-cholest-7-en-6-on.  相似文献   

13.
Using bioassay guided isolation, three novel 12 carbon polyoxygenated fatty acids and a novel abietane diterpene have been isolated from the the chloroform extract of aerial parts ofAeollanthus buchnerianus (Lamiaceae). Rigorous spectroscopic methods were used for compound identification. (Z,Z)-8-acetoxy-5-hydroxydodeca-2,6-dienoic acid and (Z,Z)-5,8-dihydroxydodeca-2,6-dienoic acid inhibited the spore germination ofCladosporium cucumerinum (both with Minimum Inhibitory Dose (MID) values of 1 g) andAspergillus niger (MID 5 and 25 g respectively). Further, they also reduced the hyphal growth ofPythium ultimum. (Z)-5-hydroxy-6,7,8-triacetoxydodeca-2-dienoic acid exhibited short term inhibition of the growth ofCladosporium cucumerinum. The novel abietane diterpenoid, (rel)-14-acetoxyabiet-7-en-18-oic acid inhibited the growth of the gram positive bacteriaBacillus subtilis, staphylococcus aureus andStreptomyces scabies (MIC values 80, 20 and 20 g ml–1 respectively).  相似文献   

14.
Summary The new methods for the production of 19-norsteroids described involve the conversion of 5-halogen-6-hydroxy-steroids into the corresponding 5-halogen-6:19-ethers either with lead tetraacetate or by the hypoiodite reaction8,10. The 6:19-oxygen bridge is then opened reductively either directly or after oxidation of the 6:19-ethers to lactones or preferably after introduction of a 4,6-3-oxo grouping. Acylolytic cleavage of the 4-3-oxo-6:19-ethers followed by alkaline hydrolysis gives 4,6-3-oxo-19-hydroxy-steroids. The 19-hydroxycompounds formed are easily converted into 19-norsteroids by known methods.

Über Steroide, 189. (vorläufige) Mitteilung; 188. Mitt. vgl.J. Kalvoda, J. Schmidlin, G. Anner undA. Wettstein, Exper.18, 398 (1962).  相似文献   

15.
    
Zusammenfassung An narkotisierten Ratten wird gezeigt, dass die Submaxillarisdrüsen sowohl mit- als auch mit-Rezeptoren für Katecholamine versehen sind. Propranolol und 1-INPEA (D(-)-1-(p-Nitrophenyl)-2-isopropylaminoethanol hydrochloride) ergeben eine wirkungsvolle Blockade der-Rezeptoren der Drüse.  相似文献   

16.
Zusammenfassung Nach. i.v. Gabe von 7-3H-Dehydroepiandrosteron wurde menschliches Plasma einer präparativen Zonenelektrophorese unterworfen und in Albumine, 1-, 2-,- und-Globuline zerlegt. Aus den einzelnen Proteinfraktionen trennte man freie Steroide, Steroid-Sulfokonjugate und -Glukuronoside ab und untersuchte letztere Fraktionen auf ihren Gehalt an markierten C19-Steroiden. Es zeigte sich, dass die Steroid-Sulfokonjugate vornehmlich in der Proteinfraktion der Albumine, die Steroid-Glukuronoside dagegen bevorzugt in der Proteinfraktion der 1-Globuline auftraten.  相似文献   

17.
Summary The structure of Resibufogenin is unambiguously shown to be 3-hydroxy-14, 15-oxido-bufadien-(20, 22)-olide on the basis of new degradation work. Artebufogenin A and Artebufogenin B are 3-hydroxy-14-15-keto-bufadien-(20, 22)-olide and 3-Hydroxy-14-14-keto-bufadien-(20, 22)-olide, respectively.  相似文献   

18.
Summary Volatile fractions of the clover head,Hypera meles (Fab.), and alfalfa,Hypera postica (Gyllenhal), weevils contained three of four boll weevil,Anthonomus grandis (Boh.), pheromone components, (Z)-3,3-dimethylcyclohexane 1,-ethanol and (Z)- and (E)-3,3-dimethylcyclohexane-1,-acetaldehyde. Also found were eight oxygenated monoterpenes, previously identified as precursors and intermediates of the boll weevil pheromones.  相似文献   

19.
Summary The-endotoxin fromBacillus thuringiensis subspecieskurstaki strain HD1-9 is almost 400 times more potent than the-endotoxin from strain HD-73 as a gypsy moth larvicide. The two-endotoxins compete for a high-affinity binding site on the brush border membrane of larval gypsy moth midguts. The affinity for the-endotoxin from strain HD-73 is much greater than the affinity for the-endotoxin from strain HD1-9.  相似文献   

20.
Zusammenfassung Die Anwendung von Hudsons Lakton-Regel auf eine Reihe von Laktonen von- und-Oxyaminosäuren bestätigte die unabhängig auf chemischem Wege bewiesenen Konfigurationen an den- und-Kohlenstoffatomen. Im Falle des erstmalig dargestellten Laktons des,-Dibenzoyl--hydroxy-d-lysins führte die Anwendung der Regel zurerythro-Struktur XV, und folglich für natürliches-Oxylysin aus Collagen zur Formel XIa, deren Beweis auf chemischem Wege noch aussteht.  相似文献   

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