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  • 1975-1979  (29)
  • 1965-1969  (20)
  • Organic Chemistry  (43)
  • Life and Medical Sciences  (6)
  • 1
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Flexible model results for the —NH2 inversion in vinylamine are compared with microwave data published by Lovas et al. [3]. The information available on the spacing of inversion levels is found to be sufficient to rule out a planar equilibrium structure. Shifts of rotational constants upon excitation of the inversion are calculated for two predicted paths of motion derived from PRDDO geometry optimization results obtained by MiiIler & Brown [2]. Partial geometry optimization yields a path inconsistent with experiment but the path obtained from complete optimization produces shifts in excellent agreement with the observed shifts. A potential energy function compatible with experimental data on spacing of inversion levels is calculated from the observed inertia defects. The inversion angle at equilibrium is slightly smaller than the angle predicted from PRDDO calculations, and the barrier to inversion, ΔV = 1.08 ± 0.07 kcal/mol, is approximately half the PRDDO value.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 321 (1979), S. 171-174 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of Sugar Esters of Lysergic Acid and 9, 10-Dihydrolysergic Acid
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 195 (1979), S. 311-316 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Unilateral ovariectomy (ULO) was carried out on rats at Day 8 of gestation: term is Day 23. The effect on peripheral plasma progesterone levels at Day 16 and on growth and cellular changes in the remaining corpora lutea (CL) at Day 17 was determined by comparison with results from control and sham-operated rats. ULO increased the volume of remaining CL by 18% at Day 17. At Day 16 this effect was only apparent in rats with three or fewer CL remaining. CL hypertrophy was due to an increase in the volume of individual luteal cells and not to cell hyperplasia. Luteal cell nuclear volume also increased as did the number of endothelial cells per corpus luteum. The proportion of the corpus luteum occupied by vascular space did not alter.ULO had little effect on mean plasma progesterone levels at Day 16 (92 ± 7 ng/mltreated; 86 ± 11 ng/ml controls). In rats with three or fewer CL remaining, however, progeserone levels were low (51 ± 7 ng/ml).It was concluded that ULO can enhance the growth of corpora lutea and perhaps increase their rate of progesterone production.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 195 (1979), S. 357-374 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The morphogenetic events associated with rabbit eggs aged in vitro for 12 to 50 hours prior to mixing with sperm have been examined by light and electron microscopy. After 12 hours in culture, morphological alterations of the meiotic spindle and the cortex of unfertilized eggs were evident. By 24 to 50 hours in culture, unfertilized eggs contained subnuclei, structures which formed when individual and/or groups of meiotic chromosomes dispersed and became invested by a double-laminated structure reminiscent of a nuclear envelope.Although most eggs obtained 11.5 to 12 hours after induced ovulation and in vitro fertilized displayed morphogenetic patterns similar to those described for in vivo fertilized ova, some (10%) contained three pronuclei. Many eggs obtained 13 to 15 hours after induced ovulation and subsequently mixed with sperm in vitro appeared to undergo processes of fertilization typical of in vivo fertilized eggs, however, approximately 30% contained subnuclei in association with the male pronucleus. Few eggs (15%) aged 12 hours prior to in vitro fertilization displayed patterns of pronuclear development and association typical of fertilized unaged ova. Subnuclei developed in many of the fertilized ova. Supernumerary sperm nuclei, which did not develop into male pronuclei, were observed in some zygotes. Cleavage of eggs aged 12 hours prior to fertilization was abnormal or retarded. After 24 hours in culture approximately 16% of the eggs fertilized. Seventy percent of the fertilized eggs failed to Support the development of a male or female pronucleus.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 193 (1979), S. 823-830 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The cellular pattern of corpus luteal (CL) growth was studied in rats at Days 6, 10, 12, 14, 16, 17 and 22 of pregnancy: term is Day 23. Measurements were taken of the percentage of the CL occupied by luteal cells, connective tissue and vascular space, luteal cell and nuclear volumes, and the number of luteal and endothelial cells in each of three CL in both ovaries of five rats at each stage of pregnancy. Total CL volume increased from 1.08-3.23 μl over Days 10-17. This was mainly due to an increase in luteal cell volume from 3.72 pl to 9.30 pl. Neither the number of luteal cells per CL (range 212,000-287,000) nor the percentage of the CL occupied by luteal cells (range 85-90%) had much influence on growth. Nuclear volume increased roughly in proportion to cytoplasmic volume but near term it decreased despite little change in cytoplasmic volume. The number of endothelial cells per CL increased steadily from 398,000 at Day 6 to 1,545,000 at Day 22. There was a strong negative correlation (r = -0.78) between the number of luteal cells per CL and mean luteal cell volume that was evident at all stages of pregnancy. There was a positive, but weaker correlation (r = 0.35) between number of luteal cells and CL volume. Thus, CL volume seems to be partly determined by the number of luteal cells at Day 6 but this effect is moderated by local control of luteal cell volume.
    Additional Material: 2 Tab.
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  • 6
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Phase microscopic investigations of Kolmer-fixed, depigmented sections of the adult chicken retina have provided photomicrographic evidence of the existence of three different photoreceptors: single rods, single cones, and double cones. The rod extends the entire thickness of the visual cell layer and is characterized by a uniformly thick outer segment and a hyperboloid-containing inner segment which is devoid of an oil droplet. The single cone is the shortest element; it contains a red oil droplet. The double cone consists of two unequal members, a tall, slender chief cone and a broad accessory cone. The chief component contains a large yellow oil droplet, whereas the accessory cone houses a small, oval, yellowish-green droplet and a characteristically large, oval paraboloid. The rod hyperboloid and the accessory cone paraboloid contain glycogen. No colorless droplets have been observed. Owing to the close association between oil droplet color and cone type, three colored layers of oil droplets are formed within the thickness of the retina: a proximal row of red droplets (the short, single cones), an intermediate layer of yellowish-green droplets (the accessory cones), and a distal row of yellow droplets (the tall chief cones).
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Microfilaments (MF, 5-8 nm in diameter) are a prominent feature of the pinealocyte cytoplasm of baboons (Papio ursinus) kept under controlled lighting conditions. MF occurred as a filamentous network in these cells during the light phase of the diurnal light-dark cycle, while a close structural association was noted between MF and the membranes of the smooth endoplasmic reticulum (SER). This association was especially evident during the dark period. Increased numbers of single synaptic ribbons (SR, vesicle-crowned rodlets), together with large aggregations of SR, i.e., ribbon fields (RF), were seen in the pinealocyte cytoplasm of baboons killed during the dark phase. It is suggested that the vesicles of RF may arise from those of the SER and that MF may play a role in the movement of SER-vesicles to those areas of the cytoplasm where new RF are being formed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aus 1,2,4-Trimethoxybenzol (I) wurde das 2-Methyl-3-acetonyl-7-methoxynaphtazarin (Isojavanicin) (XIIe) synthetisiert, wobei als entscheidende Aufbaureaktion die Einführung des Acetonylrestes durch MICHAEL-Addition von Acetessigsäure-benzylester an das 2-Methyl-5,7,8-trimethoxy-1,4-naphtochinon (VIII) erfolgte. Entgegen unseren früheren Versuchen ermöglichte die analoge Anlagerungsreaktion an 3-Methyl-5,7,8-trimethoxy-1,4-naphtochinon (XVII) eine wesentliche Vereinfachung der Synthese des Javanicins (XXa). Erwartungsgemäss zeigten Javanicin (XXa) und Isojavanicin (XIIe) in UV., IR., NMR. und Massenspektrogramm keine oder nur geringe, strukturell noch nicht interpretierbare Unterschiede, während die Mischprobe der beiden Substanzen eine überraschend grosse Schmelzpunktdepression gab.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 50 (1967), S. 1866-1879 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The trimethylsilyl ethers of reduced vitamins K1, K2, and of phytylubiquinone were investigated by means of gas chromatography and mass spectrometry.
    Additional Material: 13 Ill.
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  • 10
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aus den getrockneten Blättern von Isoplexis canariensis liess sich nach leichter Abänderung des früher [2] beschriebenen Verfahrens in etwa 1% Ausbeute ein Kristallisat gewinnen, das aus den zwei Glykosidgemischen «A» und «B» im ungefähren Verhältnis 1:4 besteht. Diese unterscheiden sich nur im Zuckerteil - Canarobiose beim Glykosid «A» und Digilanidobiose beim Glykosid «B» - und besitzen die gleichen Aglykone: Uzarigenin, Canarigenin und Xysmalogenin. -2 der 3 Komponenten des Glykosids «A», nämlich Uzarigenin-glucosido-canarosid und Canarigenin-glucosido-canarosid, konnten als einheitliche Kristallisate gewonnen und in die Desglucoprodukte übergeführt werden. Das der 3. Komponente des Glykosids «A» entsprechende Desglucoprodukt, das Xysmalogenin-canarosid, liess sich aus dem Monosidgemisch «e» [2] (das aus «A» durch enzymatische Hydrolyse entsteht) gewinnen. -Das Glykosid «B» konnte bisher noch nicht in seine 3 Komponenten aufgeteilt werden. Aus seinem Monosidgemisch «d» wurden Uzarigenin-digitoxosid sowie Canarigenin-digitoxosid als einheitliche Glykoside und, nach saurer Hydrolyse, Xysmalogenin, das Aglykon des dritten Digitoxosids von «d», gewonnen. - Aus den Mutterlaugen der Glykosidgemische «A» und «B» konnten noch die Substanzen C und «D» erhalten werden. C ist Canarigenin-glucosido-fucosid, während «D» ein Gemisch mehrerer Glykoside darstellt.
    Type of Medium: Electronic Resource
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