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1

Digitale Medien

Inhibition of the metabolism of ram spermatozoa by derivatives of α-chlorohydrin (1981)

Brown-Woodman, P. D. C. ; White, I. G. ; Ridley, D. D.

New York, NY : Wiley-Blackwell

Gamete Research 4 (1981), S. 203-217

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ISSN: 0148-7280

Schlagwort(e): α-chlorohydrin ; antifertility agent ; ram ; sperm metabolism ; Life and Medical Sciences ; Cell & Developmental Biology

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Biologie

Notizen: The effects of the male antifertility agent, α-chlorohydrin, six of its derivatives, and glycidol were studied on the metabolism of washed ram spermatozoa in vitro with fructose as substrate. The α-chlorohydrin derivatives were the amino, the phosphorylated, and four glycol-bridge (ketal) compounds. All compounds except glycidol, in a concentration between 0.1 and 100 mM, reduced the aerobic glycolsis and/or oxidation of fructose. However, there was not a high correlation between the ability of these compounds to inhibit the metabolism of ram spermatozoa in vitro and their antifertility activity when administered to male rats. Other factors are clearly involved in their antifertility activity, eg, the concentration of the compounds in the epididymis and their conversion of either more or less spermicidal compounds in the body.

Zusätzliches Material: 1 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/mrd.1120040305

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2

Digitale Medien

A crustacean statocyst with only three hairs: Light and scanning electron microscopy (1981)

Rose, R. D. ; Stokes, D. R.

New York, NY : Wiley-Blackwell

Journal of Morphology 169 (1981), S. 21-28

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ISSN: 0362-2525

Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Biologie , Medizin

Notizen: Standard histological and SEM techniques have been used to examine the pair of statocyst organs located in the telson of the isopod, Cyathara polita. Each organ is formed as an invagination of the dorsal cuticle of the telson. The invagination narrows to form a stalk between the statocyst and dorsal surface. A canal courses longitudinally through this stalk and forms a continuous channel between the lumen of the cyst and the external environment. On the luminal floor of each statocyst, there are three pits; each correlates with a nodule protruding from the ventro-medial wall. From each pit, a single, bifurcating hair projects dorsally to contact the single concretion within the statocyst lumen. No other static organs have been found in this animal. Thus, maintenance of equilibrium in this species appears to be under the control of but six hairs, three in each statocyst. Innervation of each statocyst is provided by a branch of a nerve which connects anteriorly with the last abdominal ganglion.

Zusätzliches Material: 13 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jmor.1051690103

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3

Digitale Medien

Transforming viruses directly reduce the cellular growth requirement for a platelet derived growth factor (1978)

Scher, Charles D. ; Pledger, W. J. ; Martin, Paul ; [weitere]

New York, NY [u.a.] : Wiley-Blackwell

Journal of Cellular Physiology 97 (1978), S. 371-380

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ISSN: 0021-9541

Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Biologie , Medizin

Notizen: Early passage mouse embryo fibroblasts, mouse 3T3 cell lines, and early passage diploid human fibroblasts grew to higher cell densities in tissue culture medium supplemented with serum than in medium supplemented with defibrinogenated platelet-poor plasma (PPP). Unlike the mouse cells, the human fibroblasts displayed this differential growth response only in the presence of hypophysiologic concentrations of calcium. The addition of heat-treated extracts of human platelets to PPP-supplemented medium stimulated the replication of both the normal mouse cells and early passage human embryo fibroblasts.Human or mouse fibroblasts transformed by either retroviruses or by SV40, including SV40 infected “serum revertants” and “flat transformants,” grew to equal cell densities in medium supplemented with either serum or PPP. Infection of Balb/c-3T3 cells with SV40 rapidly induced them to grow in PPP-supplemented medium demonstrating that the ability of SV40-transformed cell lines to proliferate in PPP-supplemented medium does not arise from the cell culture selection procedures usually employed to obtain stable virus-transformed cell lines. 3T3 cells infected but not transformed by retroviruses do not replicate in PPP-supplemented medium demonstrating that reduction of the growth requirement for the platelet growth factor(s) by retroviruses is a transformation-specific response. Cell cultures that did not proliferate well in PPP-supplemented medium did not form tumors when inoculated into athymic nude mice. Many, although not all, of the lines which grew well in PPP medium were tumorigenic in nude mice. Together, these findings indicate that: (1) normal fibroblast-like cells display a growth requirement for factor(s) present in serum but not found in PPP; (2) this serum specific growth factor is derived from platelets; (3) a primary response to viral transforming genes is a reduction in the growth requirement for these platelet-derived factors; and (4) cells that have a reduced requirement for the platelet-derived growth factor are often tumorigenic.

Zusätzliches Material: 4 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jcp.1040970312

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4

Digitale Medien

Chronic exposure to 60-Hz electric fields: Effects on pineal function in the rat (1981)

Wilson, Bary W. ; Anderson, Larry E. ; Ian Hilton, D. ; [weitere]

New York, NY [u.a.] : Wiley-Blackwell

Bioelectromagnetics 2 (1981), S. 371-380

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ISSN: 0197-8462

Schlagwort(e): electric fields ; 60 Hz ; pineal gland ; circadian rhythm ; melatonin ; 5 methoxytryptophol ; acetyl transferase ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Biologie , Physik

Notizen: As a component of studies to search for effects of 60-Hz electric field exposure on mammalian endocrine function, concentrations of melatonin, 5-methoxytryptophol, and serotonin-Nacetyl transferase activity were measured in the pineal glands of rats exposed or sham-exposed at 65 kV/m for 30 days. In two replicate experiments there were statistically significant differences between exposed and control rats in that the normal nocturnal increase in pineal melatonin content was depressed in the exposed animals. Concentrations of 5-methoxytryptophol were increased in the pineal glands of the exposed groups when compared to shamexposed controls. An alteration was also observed in serotonin-N-acetyl transferase activity, with lower levels measured in pineal glands from exposed animals.

Zusätzliches Material: 4 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/bem.2250020408

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5

Digitale Medien

A computational modeling study of the low-temperature pyrolysis of n-alkanes; mechanisms of propane, n-butane, and n-pentane pyrolyses (1975)

Allara, D. L. ; Edelson, D.

New York, NY : Wiley-Blackwell

International Journal of Chemical Kinetics 7 (1975), S. 479-507

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ISSN: 0538-8066

Schlagwort(e): Chemistry ; Physical Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: The mechanisms of the pyrolyses of the n-alkanes C3H8, n-C4H10, and n-C5H12 at temperatures between 390 and 560°C have been studied by the construction and evaluation of sets of several hundred reactions. Rate parameter values were assigned using literature data and calculated estimates. Time-dependent numerical solutions were computed for the experimental conditions of several rate and product studies reported in the literature. The comparisons of these a priori computations with experiment show excellent agreement for propane and agreement for butane and pentane within the estimated error limits of the assigned rate parameters. These results demonstrate that the general “state of knowledge” of the mechanism of alkane pyrolysis, namely, the reactions and their rate parameters, is such that reasonable a priori predictions of experimental results can be made. Discussions of the major stepwise processes in the pyrolyses are presented, and the importance of allyl radicals in termination is demonstrated.

Zusätzliches Material: 13 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/kin.550070402

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6

Digitale Medien

A kinetics study of the reactions of OH with several aromatic and olefinic compounds (1978)

Ravishankara, A. R. ; Wagner, S. ; Fischer, S. ; [weitere]

New York, NY : Wiley-Blackwell

International Journal of Chemical Kinetics 10 (1978), S. 783-804

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ISSN: 0538-8066

Schlagwort(e): Chemistry ; Physical Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: The reactions of hydroxyl radicals with eight substituted aromatic hydrocarbons and four olefins were studied utilizing the flash photolysis-resonance fluorescence technique. The rate constants were measured at 298°K using either Ar or He as the diluent gas. The values of the rate constants (k × 1012) in the units of cm3/molec. sec are (a) OH + o-xylene → products: (12.9±3.8), 20 torr He; (13.0±0.3), 20 torr Ar; (12.4±0.1), 200 torr He;(b) OH + m-xylene → products: (15.6±1.4), 3 torr Ar; (19.4±0.8), 20 torr Ar; (21.4±0.2), 20 torr He; (20.3±1.9), 200 torr Ar; (20.6±1.3), 200 Torr He;(c) OH + p-xylene → products: (8.8±1.2), 3 torr Ar; (10.1±1.0), 20 torr He; (10.5±0.6), 200 torr He;(d) OH + ethyl benzene → products: (7.50±0.38), 3 torr He; (7.06±0.26), 20 torr He; (7.95±0.28), 200 torr He;(e) OH + n-propylbenzene → products: (6.40±0.36), 20 torr He; (5.86±0.16), 200 torr He;(f) OH + isopropylbenzene → products: (7.79±0.40), 200 torr He;(g) OH + hexafluorobenzene → products: (0.221±0.020), 20 torr He; (0.219±0.016) 200 torr He;(h) OH + n-propyl pentafluorobenzene → products: (2.52±0.54), 3 torr He; (3.01±0.76), 20 torr He; (3.06±0.24), 200 torr He;(i) OH + propylene → products: (25.6±1.2), 20 torr He; (26.3±1.2), 200 torr He;(j) OH + 1-butene → products: (29.6±1.9), 3 torr He; (29.4±1.4), 20 torr He;(k) OH + cis-2-butene → products: (43.2±4.1), 3 torr He; (42.6±2.5), 20 torr He;(l) OH + tetramethylethylene → products: (56.9±1.3), 20 torr He.

Zusätzliches Material: 15 Tab.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/kin.550100802

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7

Digitale Medien

Very low-pressure pyrolysis of cyclobutyl cyanide. The cyano stabilization energy (1975)

King, Keith D. ; Goddard, Richard D.

New York, NY : Wiley-Blackwell

International Journal of Chemical Kinetics 7 (1975), S. 109-123

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ISSN: 0538-8066

Schlagwort(e): Chemistry ; Physical Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: A very low-pressure pyrolysis (VLPP) apparatus has been constructed and shown to yield kinetic data consistent with other VLPP systems. The technique has been applied to the pyrolysis of cyclobutyl cyanide over the temperature range of 833-1203°K. The reaction was found to proceed via a single pathway to yield ethylene and vinyl cyanide. If A∞ is based on previous high-pressure data for this reaction and for cyclobutane pyrolysis, then RRKM theory calculations show that the experimental unimolecular rate constants are consistent with the high-pressure Arrhenius parameters given by \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}\,k_\infty ({\rm sec}^{{\rm - 1}}) = 15.0 - (57.0 \pm 1.0)/\theta $$\end{document} where θ=2.303 RT in kcal/mole. If A∞ is adjusted relative to the more recent parameters for cyclobutane pyrolysis suggested by VLPP studies, then the Arrhenius expression becomes \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log }\,k_\infty ({\rm sec}^{{\rm - 1}}) = 15.9 - (59.1 \pm 1.0)/\theta $$\end{document} The cyano group reduces the activation energy for cyclobutane pyrolysis by 6±1 kcal/mole, and on the basis of a biradical mechanism this value may be attributed to the cyano stabilization energy.

Zusätzliches Material: 4 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/kin.550070112

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8

Digitale Medien

Spirocyclische Titanamide mit der Diphenylsila-titanadiazacyclobutan- Baueinheit. Kristall- und Molekülstruktur von Ti[(NSiMe3)2SiPh2]2 [1]Professor Marianne Baudler zum 60. Geburtstage am 27. April 1981 gewidmet (1981)

Beiersdorf, W. D. ; Brauer, D. J. ; Bürger, H.

Weinheim : Wiley-Blackwell

Zeitschrift für anorganische Chemie 475 (1981), S. 56-66

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ISSN: 0044-2313

Schlagwort(e): Chemistry ; Inorganic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: Durch Umsetzung der N-lithiierten Silylamine Ph2Si(NHR)2 mit SiCl4 bzw. TiBr4 wurden die spirocyclischen Amide B (R = Me, Et, i-Pr) und C (R = i-Pr, Me3Si) dargestellt und ihre Konstitution durch Analysen, 1H- und 29Si-NMR-Spektren gesichert. Von C, R = Me3Si, wurde an einem Einkristall eine Röntgenstrukturanalyse durchgeführt. Wichtige Strukturdaten sind: TiN 1,918(2) Å, SiN endocycl. 1,750(2) Å, exocycl. 1,738(2) Å, ∢ SiNTi 90,3(1)°.Spirocyclic Titanium Amides Containing the Diphenylsila-titana-diazacyclobutane Fragment. Crystal and Molecular Structure of Ti[(NSiMe3)2SiPh2]2By reaction of the N-lithiated silylamines Ph2Si(NHR)2 with SiCl4 and TiBr4, the spirocyclic amides B (R = Me, Et, i-Pr) and C (R = i-Pr, Me3Si) respectively have been prepared. Their constitutions have been confirmed by elemental analyses and by 1H and 29Si nmr spectroscopy. C, R = Me3Si, has been investigated by a single crystal x-ray structure analysis. Important structural parameters are: TiN 1.918(2) Å, SiN endocycl. 1.750(2) Å, exocycl. 1.738(2) Å, ∢ SiNTi 90.3(1)°.

Zusätzliches Material: 2 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/zaac.19814750408

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9

Digitale Medien

29Si-NMR-Spektroskopie an Silicatlösungen. II. Zur Abhängigkeit der Struktur der Silicatanionen in wäßrigen Natriumsilicatlösungen vom Na : Si-Verhältnis (1975)

Engelhardt, L. G. ; Zeigan, D. ; Jancke, H. ; [weitere]

Weinheim : Wiley-Blackwell

Zeitschrift für anorganische Chemie 418 (1975), S. 17-28

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ISSN: 0044-2313

Schlagwort(e): Chemistry ; Inorganic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Beschreibung / Inhaltsverzeichnis: 29Si-NMR Spectroscopy of Silicate Solutions. II. On the Dependence of the Structure of Silicate Anions in Water Solutions from the Na : Si RatioThe 29Si-FT-NMR spectra of 13 sodiumsilicate solutions with different Na:Si ratios are investigated with regard to the structure of the silicate anions in the solutions. The 5 typical building units (Monosilicate, end-, middle-, branching and crosslinking groups) show characteristic and non overlapping ranges of the 29Si chemical shift with many signals splittings caused by different neighbouring group effects. The relative intensities of the signals give informations on the concentrations and the equilibrium of condensation of the silicate anions in dependence of the Na:Si ratio. It is shown, that many types of anions with different degree of condensation coexist in an equilibrium, which is shiftet to the polymer silicate anions with high content of branching and crosslinking groups on the decrease of the Na:Si ratio.

Notizen: Die 29Si-FT-NMR-Spektren von 13 Natriumsilicatlösungen mit unterschiedlichem Na:Si-Verhältnis werden in Hinblick auf die Struktur der in den Lösungen auftretenden Silicatanionen untersucht. Für die 5 möglichen Baugruppen (Monosilicat, Endgruppen. Mittelgruppen, Verzweigungs- und Vernetzungsgruppen) lassen sich definierte Bereiche der 29Si-chemischen Verschiebung angeben, in denen durch Einfluß der weiteren strukturellen Umgebung i. a. zahlreiche Signalaufspaltungen beobachtet werden. Aus den relativen Intensitäten der Signale können Aussagen über die Konzentrationsverteilung und damit über das Kondensationsgleichgewicht der Silicatanionen in Abhängigkeit vom Na:Si-Verhältnis abgeleitet werden. Es zeigt sich, daß zahlreiche Anionentypen mit unterschiedlichem Kondensationsgrad nebeneinander in einem Gleichgewicht vorliegen, das sich mit fallendem Na:Si-Verhältnis stark auf die Seite höhermolekularer Silicatanionen mit hohem Gehalt an Verzweigungs- und Vernetzungsgruppen verschiebt.

Zusätzliches Material: 4 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/zaac.19754180103

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10

Digitale Medien

Zur Kenntnis der Hydrate des Na2PHO3, Phasenbeziehungen und kristallographische Untersuchungen (1978)

Brodalla, D. ; Goeters, C. ; Kniép, R. ; [weitere]

Weinheim : Wiley-Blackwell

Zeitschrift für anorganische Chemie 439 (1978), S. 265-274

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ISSN: 0044-2313

Schlagwort(e): Chemistry ; Inorganic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Beschreibung / Inhaltsverzeichnis: On the Hydrates of Na2PHO3, Phase Relations and Crystallographic InvestigationsDehydration of Na2PHO3,5 H2O to the respective anhydrous salt was investigated by thermogravimetry and differential thermal analysis. In the course of dehydration an intermediate lower hydrate is formed, Na2PHO3,0.5 H2O. Single crystals of this phase were grown from solution. Na2PHO3,0.5 H2O is rhombohedral, space group R32, R3m or R3m, with a = 18.918(5) Å and α = 33.00(2)°. - The crystal structure of Na2PHO3,5 H2O was redetermined. The pentahydrate is orthorhomic, space group Pnm21, with a = 7.190(1), b = 6.447(1), c = 9.230(2) Å. The structure consists of layers of Na-coordinating polyhedra which share edges and vertices. The layers are connected to a threedimensional structure by hydrogen bonds of the water molecules.

Notizen: Die Dehydratisierung von NaaPHO3 · 5 H2O zum wasserfreien Salz wurde mit Thermogravimetrie und Differentialthermoanalyse untersucht. Die Entwässerung verläuft über die Stufe eines intermediären niederen Hydrates, Na2PHO3 · 0,5 H2O. Einkristalle des Hemihydrates konnten aus Lösung gezüchtet werden; es kristallisiert rhomboedrisch, Raumgruppe R32, R3m oder R3m, mit a = 18,918(5) ß und α = 33,00(2)°. - Die Kristallstruktur von Na2PHO3 · 5 H2O wurde neu bestimmt. Das Pentahydrat kristallisiert orthorhombisch, Raumgruppe Pnm21 mit a = 7,109(1), b = 6,447(1), c = 9,230(2) Å. Die Struktur ist aus Schichten von kanten- und eckenverknüpften Na-Koordinationspolyedern aufgebaut. Die Schichten werden durch Wasserstoffbrückenbindungen der Wassermoleküle zu einem dreidimensionalen Strukturverband verknüpft.

Zusätzliches Material: 9 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/zaac.19784390132

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