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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 125 (1977), S. 29-37 
    ISSN: 1432-1076
    Keywords: Osteogenesis imperfecta ; Collagen types ; Bone ; In vitro study ; Immunofluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Samples of bone from a patient with osteogenesis imperfecta were found to synthesize and contain type III collagen as well as type I collagen. Normal bone contains only type I collagen except in the lining cells of the bone marrow cavities. In the patient's tissue, type III collagen was localized in nonfibrillar structures in discrete areas of the bone. These and previous studies indicate that certain types of osteogenesis imperfecta may be caused by a failure of normal bone maturation and the sites in which the type III collagen is found appear to be defects in the bone.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 18 (1987), S. 205-212 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Drilling of Short-Fiber-Reinforced AluminiumThe new material-group of fiberreinforced metals requires a specific cutting technology because of the extreme abrasion of the used fibers. For these first fundamental drilling-tests a composite of aluminium matrix and short nondirectional Al2O3-fibers was used. Neither in regard to the cutting forces nor to the drilling-quality there were any difficulties found. As far as boring roughness and -diameter is concerned the results are better than for not reinforced aluminium. Main problem is the tool wear that already increases at small contents of fibers. Using coolant a further increase of tool wear was found. Decisive improvements were achieved by taking polycristalline diamond tipped drills that had an 50 to 100 times longer tool life compared with the carbide drills.
    Notes: Faserverstärkte Metalle stellen eine junge Werkstoffgruppe dar, deren Bearbeitung aufgrund der außerordentlich hohen Abrasivität der verwendeten Verstärkungsfasern einer spezifischen Technologie bedarf. Erste grundlegende Untersuchungen hierzu wurden beim Bohren von Aluminium mit ungerichteten Al2O3-Kurzfasern durchgeführt. Es zeigte sich, daß weder in bezug auf die Bearbeitungskräfte noch auf die Bohrungsqualität Probleme auftreten. Vielmehr lassen sich teilweise bessere Bearbeitungsergebnisse als bei unverstärktem Material erzielen. Das zentrale Problem liegt im Werkzeugverschleiß, der bereits bei geringen Faseranteilen stark anwächst. Unter Einsatz von Kühlschmiermittel trat eine weitere Erhöhung des Verschleißes auf. Entscheidende Verbesserungen zeigen PKD-bestückte Bohrer, die 50 bis 100fache Standzeiten gegenüber den Hartmetall-Werkzeugen aufwiesen.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 273 (1993), S. 381-389 
    ISSN: 1432-0878
    Keywords: Vigilin ; Cartilage ; Bone ; Differentiation ; In-situ hybridization ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The expression of vigilin was followed during chick embryonal development by in situ hybridization. Vigilin mRNA is abundantly expressed in tissues of mesenchymal and ectomesenchymal origin. The mesenchymal primordial cells of cartilage and bone did not show any significant, expression of vigilin. As tissue differentiation proceeded, vigilin mRNA levels increased in hyaline cartilage and in both endochondral as well as intramembranous bone. The results suggest that the expression of vigilin mRNA in cartilage- and bone-forming cells chondrocytes and osteobalsts, is dependent on the stage of development and cellular differentiation, although not a unique process of bone formation. Most striking is the correlation of the maximum vigilin mRNA expression in osteoblasts and hypertrophic chondrocytes to periods when cell-specific genes were highly transcribed and substantially translated, e.g., synthesis of procollagen and formation of extracellular matrix in bone and cartilage.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Structure of Na2PtH4, a Ternary Hydride with Square Planar PtH42- GroupsThe red violet hydride Na2PtH4 is synthesized by the reaction of sodium hydride with platinum in a hydrogen atmosphere at a temperature between 280°C and 310°C. The crystal structure was determined by X-ray and neutron diffraction experiments (Na2PtD4) on powdered samples. Na2PtH4 crystallizes in a new structure type (a = 5.274(2), c = 6.788(3) Å; space group I4/mmm; Z = 2), which is characterized by planar, diamagnetic PtH42- anions. Structural relations and relative stabilities of the Na2PtH4 and the K2PtCl4 structure type are to be discussed.
    Notes: Aus NaH und metallischem Pt entsteht unter H2 (280-310°C) rotviolettes Na2PtH4. Röntgen- und Neutronenbeugung (Na2PtD4) an Pulverproben zeigen, daß Na2PtH4 in einem bisher unbekannten tetragonalen Strukturtyp (a = 5,274(2), c = 6,788(3) Å; Raumgruppe I4/mmm; Z = 2) kristallisiert. Charakteristisch sind planare, diamagnetische [PtH4]2--Anionen. Verwandtschaftsbeziehungen und relative Stabilitäten des Na2PtH4-und des K2PtCl4-Strukturtyps werden diskutiert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Magnetic Properties of NaMnP, NaMnAs, NaMnSb, NaMnBi, LiMnAs, and KMnAs, Characterized by Neutron Diffraction ExperimentsNeutron diffraction experiments led to the determination of the antiferromagnetic spin structures of NaMnP, NaMnAs, NaMnSb, NaMnBi, LiMnAs and KMnAs. For the sodium compounds an arrangement was found that can be described in the crystallographic cell; in the case of LiMnAs and KMnAs the c-axes have to be doubled. The Shubnikov-groups are P4/n′m′m′ and P4/n′cc, respectively. The values determined for the magnetic moments can be correlated with the crystal field splittings in the AMnX-structures.
    Notes: Neutronenbeugungsexperimente führten zur Bestimmung antiferromagnetischer Momentanordnungen der Verbindungen NaMnP, NaMnAs, NaMnSb, NaMnBi, LiMnAs und KMnAs. Für die Natriumverbindungen wurde eine Anordnung gefunden, die sich in der kristallographischen Elementarzelle beschreiben läßt, für LiMnAs und KMnAs ergibt sich eine Verdoppelung der c-Achse. Die Shubnikov-Gruppen sind P4/n′m′m′ bzw. P4/n′ce. Die gefundenen Werte für die magnetischen Momente der Manganatome lassen sich mit Kristallfeldgrößen der AMnX-Strukturen korrelieren.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 442 (1978), S. 11-18 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nickel(O) Complexes with the Anionic Ligands E (C6H5)-3 (E = Si, Ge, Sn)Complexes of the type MeIXNi(EPH3)X(THF)Y are formed from Ni(COD)2 by substitution with MeIEPh3 (E = Si, Ge, Sn) in THF (COD = Cyclooctadiene-1,5). In the case of the ligands GePh-3 and SnPh-3 nickel(O) is fourfold coordinated, but in the case of SiPh-3 it is only two-fold or threefold coordinated. Products of the reaction between Ni(COD)2 and LiPbPh3 are Li2Ni(COD)Ph2(THF)5 and Ph3PbPbPh3.The 1H-n.m.r., 29Si-n.m.r., and 119Sn-Mössbauer spectra of the complexes MeIXNi(EPh3)X(THF)Y are compared with the spectra of the corresponding alkali compounds MeIEPh3. The magnetic anisotropy effects of the atomes Ge, Sn, Pb and Ni are of high importance for 1H- and 29Si-chemical shifts. The donor action of SnPh-3 is shown by the Mössbauer spectrum of Na4Ni(SnPh3)4(THF)4. But there is no direct evidence of π-back donation in the compound.
    Notes: Ni(COD)2 reagiert in THF mit Verbindungen des Typs MeIEPh3 (E = Si, Ge, Sn) unter Substitution zu den Elementenkomplexen MeIXNi(EPh3)X (THF)Y. Im Falle der Ligan-den GePh-3 und SnPh-3 wird eine Viererkoordination, bei SiPh-3 dagegen nur eine Dreier- bzw. Zweierkoordination erreicht. Im Zuge der Umsetzung von Ni(COD)2 mit LiPbPh3 entsteht Hexaphenyldiplumban und Li2Ni(COD)Ph2(THF)5 (COD = Cyclooctadien-1,5)Die 1H-NMR-, 29Si-NMR- und 119Sn-Mössbauerspektren der Komplexe MeIXNi(EPh3)X(THF)Y werden mit denen der Alkaliverbindungen MeIEPh3 verglichen. Für die Größe der chemischen Verschiebungen sind magnetische Anisotropieeffekte der Atome Ge, Sn, Pb und Ni von erstrangiger Bedeutung. Das 119Sn-Mössbauerspektrum von Na4Ni(SnPh3)4(THF)4 läßt den n-Donatorcharakter der Liganden SnPh-3 erkennen. Für eine π-Rückgabebindung zwischen dem Zentralatom und diesen Liganden kann kein Nachweis erbracht werden.
    Additional Material: 12 Tab.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 447 (1978), S. 18-28 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mixed Ligand Complexes of Nickel(0) and Cobalt(I) with the Anionic Ligands E(C6H5)3- (E = Ge, Sn, Pb)Complexes of the general formula MINi(PPh3)3(EPh3)(THF)x (E = Ge[Ia], Sn[Ib], Pb[Ic]) and MI3Ni(PPh3)(EPh3)3(THF)x (E = Ge[IIa], Sn[IIb]) are formed from (Ph3P)2Ni(C2H4) by substitution with MIEPh3. The analogous complexes of the ligand SiPh3- could not be prepared, because of the formation of SiPh4 from LiSiPh3 and coordinated PPh3. Attempts to synthesize a nickel(II) complex of the ligand SnPh3- had no success, only possible decomposition products of these compounds, like (nBu2PPh)2NiII(Ph)Cl and NaxNi°(PPh3)4-x(SnP4)x(THF)Y, were isolated. NaCoI(PPh3)2(SnPh3)2(THF)7 (IV) was prepared by the reaction of Co(PPh3)3Cl and NaSnPh3.1H-NMR and 119Sn Mössbauer spectra show a higher donor action of SnPh3- in IIb than in Ib. This causes a stronger π-back donation Ni → P in the case of IIb. IV is a paramagnetic compound, the vis-spectrum is discussed using simple crystal field theory.
    Notes: (Ph3P)2Ni°(C2H4) reagiert mit Verbindungen des Typs MIEPh3 unter Substitution zu Gemischtligand-Komplexen MINi°(PPh3)3(EPh3)(THF)x (E = Ge[Ia], Sn[Ib], Pb[Ic]) bzw. MI3 Ni°(PPh3)3(EPh3) (THF)x (E = Ge[IIa], Sn[IIb]). Analoge Komplexe mit dem Liganden SiPh3- konnten nicht isoliert werden, da LiSiPh3 mit komplex gebundenem PPh3 zu SiPh4 reagiert. Versuche zur Synthese von Nickel(II)-Komplexen des Liganden SnPh3- blieben ohne Erfolg, es wurden nur mögliche Zersetzungsprodukte dieser Verbindungen isoliert [(nBu2PPh)2Ni(Ph)Cl und NaxNi(PPh3)4-X(SnPh3)x(THF)Y]. Die Umsetzung von (Ph3P)3CoCl mit NaSnPh3 führt zu NaCoI (PPh3)2(SnPh3)2(THF)7.Aus den 1H-NMR- und den 119Sn-Mößbauerspektren ergibt sich, daß die Donatorwirkung der Liganden SnPh3- beim Übergang von Ib zu IIb ansteigt. Daraus resultiert für IIb eine im Vergleich zu Ib höhere π-Backdonation. IV ist paramagnetisch, das VIS-Spektrum kann auf der Basis der Kristallfeldtheorie erklärt werden.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structure and Properties of Cesium Hydroxide Monohydrate, a Compound Characterized by Layered [H3O2-] Polyanions in its High Temperature FormCesium hydroxide monohydrate, which was formed at the synthesis of cesium hydride as a by-product, was obtained in form of single crystals by recrystallization from ammonia in high pressure autoclaves. Temperature dependent X-ray structure investigations and measurements of the specific heat show the occurance of several modifications. At 293 K X-ray data prove that it is possible to distinguish between OH- ions and H2O molecules. This can also be confirmed by IR spectroscopy. At 355 K and 400 K the investigations on single crystals show layered [H3O2-] polyanions, which are separated by layers of cesium ions in a hexagonal unit cell.
    Notes: Caesiumhydroxidmonohydrat, dessen Bildung als Nebenprodukt bei der Synthese von Caesiumhydrid beobachtet wurde, konnte in Form von Einkristallen durch Umkristallisieren aus Ammoniak in Hochdruckautoklaven erhalten werden. Temperaturabhängige röntgenographische Strukturuntersuchungen sowie Messungen der spezifischen Wärme lassen mehrere Modifikationswechsel erkennen. Bei 293 K ist noch eine Unterscheidung von OH--Ionen und H2O-Molekülen gegeben, ein Befund, den auch IR-spektroskopische Messungen bestätigen. Bei 355 und 400 K lassen die Untersuchungen an Einkristallen mit hexagonaler Metrik schichtenförmige [H3O2-]-Polyanionen erkennen, die durch Caesiumionen getrennt sind.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 56 (1943), S. 218-218 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Product demands for polypropylene polymers cover a wide range of properties. Metallocene catalysts open up the way to influence the molecular properties of polypropylene by altering the ligand system of the metallocene complexes. This leads to new products with application properties which are not available with conventional catalysts. Concepts are presented to adapt metallocenes to modern, industrial polymerization processes. Some examples illustrate the particular advantages of this new generation of catalysts.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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