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  • Artikel  (22)
  • Chemistry  (19)
  • Chondrichthyes  (2)
  • Annulate lamellae  (1)
  • Wiley-Blackwell  (19)
  • Springer  (3)
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  • 1980-1984  (12)
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  • Artikel  (22)
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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 156 (1975), S. 475-482 
    ISSN: 1432-0878
    Schlagwort(e): Annulate lamellae ; Spermatocytes ; Grasshoppers ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Intranuclear and cytoplasmic annulate lamellae were studied in grasshopper spermatocytes (Melanoplus) with the electron microscope. Although cytoplasmic annulate lamellae were observed in all three species examined, intranuclear annulate lamellae were found in only one species. The intranuclear annulate lamellae encompass certain nuclear material adjacent to the nuclear envelope forming a vesicle that is extruded into the spermatocyte cytoplasm. In this same species, cytoplasmic annulate lamellae are seen contiguous with granular masses of varying size. These structures were noted as being morphologically indistinguishable from the “yolk nuclei” of dragonfly oocytes (Kessel and Beams, 1969; Kessel, 1973).
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Environmental biology of fishes 7 (1982), S. 207-228 
    ISSN: 1573-5133
    Schlagwort(e): Batoids ; Chondrichthyes ; Costa Rica ; Elasmobranchs ; Euryhalinity ; Freshwater adaptation ; Growth rate ; Isolation of population ; Nicaragua
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Synopsis Of a total of 377 Pristis perotteti tagged in the Lake Nicaragua-Río San Juan System, 214 (56.8% were recovered. Eighty were recovered at the original tagging site; four moved downstream the full length of the river; and 127 tagged at the source of the river were recovered in all parts of the lake. Only one was recovered in a different river system, 58 km down the coast from the main mouth of the Río San Juan. A life span of 30 years is suggested, with rapid growth (30–40 cm per year) in the first three years, slowing to about 4 or 5 cm per year in the later years of life. Maximum sizes collected were 384 cm for males, 429 cm for females, smaller than maximum lengths reported elsewhere. The lake sawfish are not physically landlocked, but individuals remain in fresh water for very long periods; parturition takes place in fresh water; all sizes are found in the lake; and it appears that this stock finds all of its ecological needs met in the lake. Individuals may spend all of their lives in fresh water, although, as a species, P. perotteti has not completely abandoned the sea, since some are known to occur in salt water. The Lake Nicaragua-Río San Juan sawfish are a discrete stock, with only limited gene flow with neighboring stocks. P. perotteti is farther along in its adaptation to fresh water, in being able both to osmoregulate and reproduce there, than other known euryhaline elasmobranchs, except for the African stingray, Dasyatis garouaensis, of the Niger-Benue System, and the completely adapted South American freshwater rays (family Potamotrygonidae).
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Environmental biology of fishes 9 (1983), S. 3-24 
    ISSN: 1573-5133
    Schlagwort(e): Amazonia ; Batoidea ; Brazil ; Captive breeding ; Chondrichthyes ; Colombia ; Elasmobranchii ; Freshwater adaptation ; Growth rate ; Potamotrygonidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Synopsis Observations of reproductive features and body measurements were made on wild-caught, freshwater stingrays, Potamotrygon circularis and P. motoro, from the Amazon drainage of western Brazil and southern Colombia. Further observations were made in Detroit's Belle Isle Aquarium on a captive pair of P. motoro and their descendants, which constitute the first known captive breeding colony of potamotrygonids. The gross structure and function of female and male reproductive systems are described. There is no obvious difference between those of the two species. They are aplacentally viviparous, the young being nourished in advanced stages by uterine milk secreted by trophonemata. Size at onset and completion of sexual maturation, breeding season and behavior, gestation period, litter size and sex ratios are discussed. Up to 21 proportional measurements were made on several fetal and postnatal stages of both species. Several proportional changes occur in very early fetal life, but most body proportions undergo only minor changes from advanced fetal through adult stages. A growth curve is proposed for P. motoro based on observations of the captive colony.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 3 (1980), S. 241-247 
    ISSN: 0935-6304
    Schlagwort(e): Gas chromatography ; Capillary, glass ; Quantitative analysis at 10-10g level ; Steroids in urine ; Amino acid fluorobutyrates (19 in 35 min) ; Installation of glass capillaries ; Connection to FM-ECD ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Glass capillary columns are ideal for analysis of urinary steroid profiles (i.e. the total steroid neutral fraction without prior separation into sub-groups).In this paper performance of both SCOT and wide-bore WCOT columns has been compared, resulting in no significant quantitative difference on urine extracts run as trimethylsilyl ether derivatives. However, because of increased efficiency the WB-WCOT column exhibited more sensitivity in measurement of small amounts of 11-ox-aetiocholanolone. Sensitivity of other steroids was greatly enhanced by use of either SCOT or WB-WCOT, leading to an almost tenfold increase over conventional packed columns (e.g. androsterone and aetiocholanolone 〈 40 μg per 24 h urine sample). A simple splitless injection system (based on a design of Dr. W. Greenaway, Oxford University) is presented.Experiments were also carried out using a SCOT column in conjunction with an FM-electron capture detector. Whilst efficiency was impaired due to the design of the detector, use of He (carrier) and N2 (make up gas) showed that several steroid derivatives could be easily measured at well below the 10-10 g level with much more rapid retention times than with a 1½m packed column. Highly successful separation of 19 amino acids (as fluoro-acyl derivatives) was achieved in 35 minutes using a SCOT (30 m) SP2100 column.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Plant/Operations Progress 3 (1984), S. 86-88 
    ISSN: 0278-4513
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: N-Methyl-N-Diethoxyphosphorylamido Derivatives of Hexachlorocyclotriphosphazatriene. I. The Reaction of Hexachlorocyclotriphosphazatriene with Sodium N-Methylamidophosphoric Acid Diethyl Ester.The reaction of hexachlorocyclotriphosphazatriene with the sodium salt of 0, 0-diethyl-N-methylamido-phosphate in the molar ratios 1:1, 1:2, and 1:3 gives a mixture of partially substituted compounds. The N-methyl-N-diethoxyphosphorylamidoderivatives, N3P3Cl6-n[NCH3P(O)(OC2H5)]n (n = 1, 2, 3) were isolated in a pure form by preparative column chromatography. Compounds with a higher degree of substitution are not formed. The compounds are characterized by their molecular weights, elementary analysis, and TLC-Rf values.
    Notizen: Die Reaktion von Hexachlorocyclotriphosphazatrien mit dem Natriumsalz des N-Methylamidophosphorsäurediäthylesters führt bei Raumtemperatur in den Molverhältnissen 1:1, 1:2 und 1:3 zu einem Gemisch partiell substituierter Verbindungen. Mit Hilfe der präparativen Säulenchromatographie konnten die N-Methyl-N-diäthoxyphosphorylamido-Derivate, N3P3Cl6-n[NCH3P(O)(OC2H5)2]n (n = 1, 2, 3); in reiner Form isoliert werden. Verbindungen höheren Substitutionsgrades wurden nicht erhalten. Die Verbindungen wurden durch ihre Molmassen, Elementaranalysen und die dünnschichtchromatographischen Rf-Werte charakterisiert und gesichert.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: N-Methyl-N-Diethoxyphosphorylamido Derivatives of Hexachlorocyclotriphosphazatriene. II. Ammonoloyses of N-Methyl-N-Diethoxyphosphorylamido-ChlorocyclotriphosphazatrienesMonokis-[N-methyl-N-diethroxyphosphorylamido]-pentachloro-cyclotriphospha-zatriene and 2, 4-bis-[N-methyl-N-diethoxyphosphorylamido]-2, 4, 6, 6-tetrachloro-cyclotriphosphazatriene react with gaseous ammonia at room temperature to the corresponding diamino compounds, N3P3CL4-n[NCH3P(O)(OC2H5)2]n(NH2)2, (n = 1, 2). Total Exchange of the chlorine in the N-Methyl-Ndiethoxyphosphorylamido-derivatives, N3P3CL6-n[NCH3P(O)(OC2H5)2]n, (n = a, 2, 3), takes place during the reaction with liquid ammonia. Aminophosphazenes of the type N3P3[NCH3P(O)(OC2H5)2]n(NH2)6-n, (n = 1, 2, 3), are formed. The described aminocyclotriphosphazatrienes are characterized by their melting points, elementary analyses, molecular weights and the TLC-Rf-values.
    Notizen: Monokis-[N-methyl-N-diäthoxyphorylamido]-pentachloro-cyclotriphosphazatrien und 2, 4-Bis-[N-methyl-N-diäthoxyphosphorylamido]-2,4,6,6-tetrachlorocyclotriphosphazatrien reagieren mit gasförmigem Ammoniak bei Raumtemperatur zu den entsprechenden diaminoverbindungen, N3P3CL4-n[NCH3P(O)(OC2H5)2]n(NH2)2, (n = 1, 2). Vollständiger Austausch des Chlors in den N-Methyl-N-diäthoxyphosphorylamido-Derivaten, S3P3CL6-n[NCH3P(O). (OC2H5)2]n, (n = 1, 2, 3). findet bei der Umsetzung mit flüssigem ammonial Statt. Es werden dabei Aminocyclophosphazene des Typs N3P[NCH33P(O)(OC2H5)2]n(NH2)6-n, (n = 1. 2. 3) gebildet, Die beschriebenen Aminocyclophosphazatriene werden durch ihre Schmelzpunkte, Elementaranalysen, Molmassen und die dünnschichtchromatographischen Rf-Werte charakterisiert.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Temperature Dependence Investigations of 31P Chemical Shifts of Trialkoxyphosphazene N-phosphoryldialkylestersThe 31P NMR spectra of a series of trialkoxyphosphazene-N-phosphoryldialkylesters, (RO)3P=N—P(O)(OR′)2, where R = R′ = Et; R = Et, R′ = Bu; R = Bu, R′ = Et; R = R′ = Bu; and R = R = R′ = Hex respectively, and of trichlorophosphazene-N-phosphoryldichloride were investigated at various temperatures. The temperature dependence of chemical shift of phosphorus belonging to the phosphazene group is multiplicately larger than that of phosphorus belonging to the phosphoryl group. This fact also could be confirmed for other simple phosphazene and phosphoryl compounds. As discussed this different temperature dependence of 31P chemical shift is not a consequence of the medium but of the molecular structure.
    Notizen: Für eine Reihe von Trialkoxyphosphazen-N-phosphoryldialkylestern, (PO)3P=N—P(O)(OR′)2, wobei R = R′ = Et; R = Et, R′ = Bu; R = Bu, R′ = Et; R = R′ = Bu bzw. R = R′ = Hex waren, sowie für Trichlorphosphazen-N-phosphoryldichlorid wurden jeweils 31P-NMR-Spektren bei verschiedenen Temperaturen aufgenommen. Es zeigte sich, daß die Temperaturabhängigkeit der chemischen Verschiebung für den Phosphor der Phosphazen-Gruppierung um ein mehrfaches größer ist als die für den Phosphor der Phosphoryl-Gruppierung. Dies konnte auch allgemein für andere einfache Phosphazen- und Phosphoryl-Verbindungen bestätigt werden. Es wird diskutiert. daß diese unterschiedliche Temperaturabhängigkeit der 31P-chemischen Verschiebung nicht auf Medieneinflüsse, sondern auf die molekulare Struktur zurückzuführen ist.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 489 (1982), S. 131-138 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: NMR Spectroscopic Studies of Exocyclic 15N Labelled AmidochlorocyclotriphosphazenesSome exocyclic 15N labelled monoamidopentachlorocyclotriphosphazenes, N3P3Cl5X, and diamidotetrachlorocyclotriphosphazenes, N3P3Cl4X2, where X = 15NH2, 15NHMe, 15NMe2, or 15NHPh, were prepared, and the 31P- and 15N-NMR spectra were recorded. The chemical shift values δP and δN and the coupling constants 1JPN and 3JPN are discussed.
    Notizen: Einige exocyclisch 15N-markierte Monoamidopentachlorocyclotriphosphazene, N3P3Cl5X, und Diamidotetrachlorocyclotriphosphazene, N3P3Cl4X2, wobei X = 15NH2, 15NHMe, 15NMe2 oder 15NHPh ist, wurden dargestellt und die 31P- und 15N-NMR-Spektren aufgenommen. Die chemischen Verschiebungen δP und δN und die Kopplungskonstanten 1JPN und 3JPN werden diskutiert.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 490 (1982), S. 121-128 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: NMR Spectroscopic Studies of 15N Labelled OxocyclophosphazanesThe completely 15N labelled cyclophosphazanes (15NMeP(OMe)O)3, (15NEtP(OEt)O)3, and (15NMeP(OMe)O)4 were prepared by rearrangement of the corresponding alkoxyphosphazenes and their 31P- and 15N-NMR spectra were investigated. On the case of the trimer compounds spectra of the ABB′XX′Y spin type were obtained; all coupling constants are relevant, and like the 15N chemical shifts they are found only by means of spectra simulations. The relative signs of the coupling constants 1JPN, 2JPP, 2JNN, and 3JPN were also obtained.
    Notizen: Die vollständig 15N-markierten Cyclophosphazane (15NMeP(OMe)O)3, (15NEtP(OEt)O)3 und (15NMeP(OMe)O)4 wurden aus den entsprechenden Alkoxyphosphazenen dargestellt und sowohl 31P- als auch 15N-NMR-spektroskopisch untersucht. Bei den trimeren Verbindungen wurden Spektren vom Spintyp ABB'XX'Y erhalten; alle Kopplungskonstanten sind relevant, sie können wie die 15N-chemischen Verschiebungen nur auf dem Wege der Spektrensimulation erhalten werden. Es ergeben sich auch die relativen Vorzeichen für die Kopplungskonstanten 1JPN, 2JPP, 2JNN und 3JPN.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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