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  • 1
    Electronic Resource
    Electronic Resource
    Berlin, Germany : Blackwell Verlag GmbH
    Anatomia, histologia, embryologia 34 (2005), S. 0 
    ISSN: 1439-0264
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Introduction:  In many breeds osteoarthrosis of the hip joint is the most typical orthopaedic disease. Numerous studies concerning etiology, pathogenesis and therapy of this disease still consider an exact congruity to be the basis of a physiological joint function. No data, however, are available as far as the distribution of load in the articular surfaces is concerned.Aims:  It was the aim of this investigation to describe the biomechanical features of the canine hip joint as exactly as possible with respect to long-term and momentary loading.Material and Methods:  Hip joints from 43 dogs (bodyweight 〉20 kg) with an average age of 6 years were investigated. The subchondral bone density was determined with the method of CT-osteoabsorptiometry. With help of cartilaginous and osseus split lines the preferential orientation of the collagen fibres could be determined. In an in vitro experimental setup the contact areas and the contact pressure distribution within the joint have been measured.Results:  In the acetabulum, maxima of subchondral bone density were distributed tricentrically: cranially, dorsally and caudally. In the femoral head, only the area close to the attachment of the ligament was highly mineralized. Cartilagineous and osseous split lines within the acetabulum gave evidence of a long-term tensile stress. In contrast to these findings, there was no clear preferential orientation in the caput ossis femoris. With load increasing initially isolated contact areas extended and became confluent at a loading force of 75% body weight. Values of maximal joint pressure (maximal joint reaction force applied: 400% bodyweight) reached 8–10 MPa.Discussion:  The findings clearly show that the articular surfaces of the hip joint are loaded inhomogeneously. For the first time, it was possible to demonstrate that the healthy canine hip joint is physiologically incongruent. Furthermore, areas of cartilage degeneration within the joint surface coincide with regions that are loaded to a higher extent a priori. From the biomechanical point of view it is recommended that all kinds of acetabular fractures – even those affecting the caudal third of the acetabulum – should be surgically repaired in an adequate way.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Berlin, Germany : Blackwell Verlag GmbH
    Anatomia, histologia, embryologia 34 (2005), S. 0 
    ISSN: 1439-0264
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Introduction:  On one hand, the distal phalanx in cattle is suspended by the wall segment of the dermis, on the other hand it is supported in the palmar/plantar region by the bulb with its specialized subcutaneous tissue. Recent results of various studies suggest that changes in tissue composition of the bulb and slackening of the suspension can lead to an unphysiological position of the distal phalanx within the horn capsule. This leads to an altered distribution of pressure and mechanically influences the dermal blood supply. In the worst case these changes may lead to sole ulcer.Aims:  The aim of this study was to develop a method to allow measuring the minimal distance between the surface of the distal phalanx and the inner surface of the horn capsule under various loading.Material and Methods:  The right front and the left hindclaws have been taken from seven healthy beef bulls (German Simmentals, average body weight 580 ± 25 kg) from the local abattoir. After functional claw trimming the feet have been scanned in a computed tomograph (veterinary surgical clinics) in unloaded and the loaded state [distribution of body weight: 55% (front legs): 45 % (hind legs)]. Each distal phalanx and claw capsule have been reconstructed in both datasets via threshholding (‘marching-cube-algorithm’). The minimal distance between both objects has been measured by the ‘nearest-neighbour-algorithm’.Results:  No significant differences could be observed between front and hind claws and lateral and medial claws respectively. In the unloaded state there was a distance of 4–6 mm in the dorsal, abaxial and axial aspect of the distal phalanx, which almost remained constant in the loaded state. On the solear surface values increased from 3 mm at the tip of the coffin bone to 7–8 mm at the flexor tubercle where significant distance changes (approx. 3 mm) could be observed.Discussion:  A tilting movement of the distal phalanx becomes obvious with loading. Thus, especially the region of transition between the soft and the hard bulb experiences heavy compressive stress. This coincides topographically with the incidence of sole ulcers.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 390 (1972), S. 1-12 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The compounds Rb2Mn3S4, Cs2Mn3S4, Rb2Co3S4 and Cs2Co3S4 were prepared by melting reactions in a nitrogen atmosphere. X-ray investigations of Cs2Mn3S4 single crystals lead to the space group Ibam-D2h26 Z = 4. The manganese- as well as the alkalimetal-atoms are arranged in layers which are separated by sulphur layers. The other compounds have an analogous structure. This could be shown by powder diffraction investigations.
    Notes: Über Schmelzreaktionen in einer Stickstoffatmosphäre wurden folgende Sulfide dargestellt: Rb2Mn3S4, Cs2Mn3S4, Rb2Co3S4 und Cs2Co3S4. Strukturuntersuchungen an Einkristallen von Cs2Mn3S4 führten zu der Raumgruppe Ibam-D2h26 mit Z = 4. Die Anordnung der Atome ergibt eine Schichtenstruktur, in der alternierende Mangan- und Alkalimetallschichten jeweils durch Schwefellagen getrennt sind. Untersuchungen an pulverförmigen Präparaten ergaben für die übrigen Sulfide einen isotypen Aufbau.
    Additional Material: 6 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 461 (1980), S. 13-21 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Crystal Structure of the Dialkali Metal Trichalcogenides Rb2S3, Rb2Se3, Cs2S3, and Cs2Se3Crystalline products were obtained by the reaction of the pure alkali metals with the chalcogens in the molar ratio 2:3 in liquid ammonia at pressures up to 3000 bar and temperatures around 600 K. The substances crystallize in the K2S3 type structure (space group Cmc21(NO. 36)). Unit cell constants see „Inhaltsübersicht“.The characteristic feature of this structure are bent polyanions X32-:(X = S,Se). The new described compounds are compared with the other known alkali metal trichalcogenides.
    Notes: Man erhält die Substanzen in kristallinerform durch Umsetzung der reinen Alkalimetalle mit den Chalkogenen in flüssigem Ammoniak im Molverhältnis 2:3 bei Drucken bis zu 3000 bar und Temperaturen um 600 K. Sie kristallisieren alle im K2S3-Typ (Raumgruppe Cmc21 (Nr. 36)). Ihre Gitterkonstanten lauten: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm Rb}_2 {\rm S}_3 :} & {{\rm a} = 751,3\left(2 \right){\rm pm},} & {{\rm b} = 1037,5\left(2 \right)\,{\rm pm},} & {{\rm c} = 776,9\left(1 \right)\,\,{\rm pm}} \\ {{\rm Rb}_2 {\rm Se}_3 :} & {{\rm a} = 785,6\left(1 \right){\rm pm},} & {{\rm b} = 1085,8\left(2 \right)\,{\rm pm},} & {{\rm c} = 777,9\left(1 \right)\,\,{\rm pm}} \\ {{\rm Cs}_2 {\rm S}_3 :} & {{\rm a} = 771,3\left(3 \right){\rm pm},} & {{\rm b} = 1093,9\left(4 \right)\,{\rm pm},} & {{\rm c} = 811,1\left(3 \right)\,\,{\rm pm}} \\ {{\rm Cs}_2 {\rm S}_3 :} & {{\rm a} = 801,5\left(3 \right){\rm pm},} & {{\rm b} = 1140,6\left(4 \right)\,{\rm pm},} & {{\rm c} = 828,2\left(2 \right)\,\,{\rm pm}} \\\end{array} $$\end{document}Das charakteristische Merkmal der Struktur sind die gewinkelten Chalkogenid-Polyanionen X32-. Die neu beschriebenen Verbindungen werden mit den anderen bis jetzt bekannten Dialkalimetall-trichalkogeniden verglichen.
    Additional Material: 2 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 467 (1980), S. 149-157 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Na2S3In the literature the existence of Na2S3 is contested, but by reaction of the elements in liquid ammonia under pressure it can be obtained. For reaction temperatures of 300-320 K and a pressure of 2000 bar a compound Na2S3 · NH3 yields. X-ray single crystal investigations are carried out and lead to a structure containing bent S32- polyanions as characteristic feature. The cell constants are as follows: a = 9.257(5) Å, b = 7.056(2) Å, c = 8.919(3) Å, β = 102.71(4)°. The space group is C2/m. The substance decomposes at 510K.
    Notes: Es wird über die Darstellung der Verbindung Na2S3 mit Hilfe der Synthese aus den Elementen in flüssigem Ammoniak unter erhöhtem Druck (Ammonothermalsynthese) berichtet. Die Reaktion führt bei 300-320 K und 2000 bar zu einem Ammoniakat Na2S3 · NH3. Die Struktur wird anhand röntgenographischer Einkristalluntersuchungen bestimmt. Die Substanz zerfällt bei höheren Temperaturen in β-Na2S2 und Na2S4.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 523 (1985), S. 145-152 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Crystal Structure of CsTe4CsTe4 results from a melting reaction at 570°C in sealed quartztubes. The starting materials Cs and Te in the molar ratio 1:4 are produced in a first step by controlled decomposition of the CsN3 from mixtures of CsN3 and Te (1:4) at 350°C.CsTe4 is monoclinic, space group P21/c, with a = 7.857(1) Å, b = 7.286(1) Å, c = 14.155(2) Å, β = 93.83(1)°, and Z = 4. The tellurium atoms form a two-dimensional puckered layer built of from pseudo-trigonal-bipyramidal, T-shaped units Te4-. The central tellurium atom of this unit may be considered as a pseudo iodine. The compound is compared with other tellurides MTen having some like that unexpected principles of connection.
    Notes: CsTe4 entsteht aus Gemengen von Caesium und Tellur im Molverhältnis 1:4, wenn man diese in abgeschlossenen Ampullen einer Schmelzreaktion bei 570°C unterwirft. Die Elementgemenge stellt man der, indem man CsN3 und Te (1:4) zusammengibt und anschließend durch kontrollierte Zersetzung des Azids den Stickstoff vertreibt.CsTe4 kristallisiert monoklin in der Raumgruppe P21/c (Z = 4) mit den Gitterkonstanten a = 7,857(1) Å, b = 7,286(1) Å, c = 14,155(2) Å, β = 93,83(1)°. In der Strukture liegt ein zweidimensional-unendliches Polyanion ∞2[Te4-] vor. Die Verwandtschaft mit anderen tellurriechen Telluriden MTen wird diskutiert.
    Additional Material: 3 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 432 (1977), S. 167-172 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal Structure of K2S3 and K2Se3Well formed crystals of K2S3 and K2Se3 were obtained by reaction of the elements in liquid ammonia at 500 bar and 150°C. The substances are both orthorhombic, space group Cmc21. Cell constants are: The structure contains S32-(Se32-) polyanions, with S—S—S(Se—Se—Se) angles of 105.4(102.5)°. The S—S(Se—Se) distance is 2.083(2.383) Å.
    Notes: Gut ausgebildete Kristalle von K2S3 und K2Se3 erhält man aus den Elementen bei 500 bar und 150°C in Ammoniak. Beide Substanzen sind isotyp und kristallisieren rhombisch in der Raumgruppe Cmc21. Die Gitterkonstanten lauten: Die Struktur enthält gewinkelte S32-(Se32-)-Polyanionen mit einem S—S(Se—Se)-Abstand von 2,083(2,383) Å und einem S—S—S(Se—Se—Se)-Winkel von 105,4(102,5)°.
    Additional Material: 2 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 542 (1986), S. 144-152 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NaTe3 - a Compound with Cuban-like Clusters Te126-NaTe3 results as a greyish microcrystalline powder if stoichiometric amounts of the pure elements sodium and tellurium (molar ratio 1:3) are allowed to react in liquid ammonia at about -50°C. After melting the crude product (500°C, 1 h, corundum crucible in sealed glass ampoule), followed by an annealing period (380°C, 5 days) NaTe3 yields as a silvery compound with metallic lustre.NaTe3 is trigonal, space group P3c1, Z = 12, with a = 9.033(2) Å and c = 21.930(4) Å. It contains Te62--chains, linked together via their terminal atoms producing infinite strings. These strings may be thought to be built up of cuban-like clusters Te126-.
    Notes: NaTe3 entsteht beim Umsatz elementaren Natriums und Tellurs im Molverhältnis 1:3 in flüssigem Ammoniak bei etwa -50°C. Es fällt nach Entfernen des Lösungsmittels als homogenes, matt dunkelgrau aussehendes, mikrokristallines Pulver an.NaTe3 kristallisiert trigonal in der Raumgruppe P3c1 mit Z = 12. Gitterkonstanten: a = 9,033(2) Å, c = 21,930(4) Å.Das Anionenteilgitter enthält verknüpfte Te62--Ketten, wodurch eindimensional-unendliche Stränge entstehen, deren bestimmendes Bauelement ein kuban-artiger Cluster Te126- ist.
    Additional Material: 2 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 476-488 
    ISSN: 0044-2313
    Keywords: Dialkali metal dichalcogenides ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Dialkali Metal Dichalcogenides β-Na2S2, K2S2, α-Rb2S2, β-Rb2S2, K2Se2, Rb2Se2, α-K2Te2, β-K2Te2 and Rb2Te2The first presentation of pure samples of α- and β-Rb2S2, α- and β-K2Te2, and Rb2Te2 is described. Using single crystals of K2S2 and K2Se2, received by ammonothermal synthesis, the structure of the Na2O2 type and by using single crystals of β-Na2S2 and β-K2Te2 the Li2O2 type structure will be refined. By combined investigations with temperature-dependent Guinier-, neutron diffraction-, thermal analysis, and Raman-spectroscopy the nature of the monotropic phase transition from the Na2O2 type to the Li2O2 type will be explained by means of the examples α-/β-Na2S2 and α-/β-K2Te2. A further case of dimorphic condition as well as the monotropic phase transition of α- and β-Rb2S2 is presented. The existing areas of the structure fields of the dialkali metal dichalcogenides are limited by the model of the polar covalence.
    Notes: Die erstmalige Darstellung phasenreiner Proben von α- und β-Rb2S2, von α- und β-K2Te2 und von Rb2Te2 wird beschrieben. Mit Hilfe von ammonothermal synthetisierten Einkristallen des K2S2 und des K2Se2 wird die Struktur des Na2O2-Typs, mit Einkristallen des β-Na2S2 und des β-K2Te2 die des Li2O2-Typs verfeinert. Durch kombinierte temperaturabhängige Guinier-, Neutronenbeugungs-, thermoanalytische und Raman-spektroskopische Untersuchungen wird die Natur des monotropen Phasenübergangs vom Na2O2-Typ zum Li2O2-Typ an Hand der Beispiele α-/β-Na2S2 und α-/β-K2Te2 aufgeklärt. Ein weiterer Fall von Dimorphie, der ebenfalls monotrope Übergang von α-Rb2S2(Rb2O2-Typ) zu β-Rb2S2(Na2O2-Typ), wird vorgestellt. Die Existenzgebiete der Strukturfelder bei den Dialkalimentalldichalkogeniden werden mittels des Modells der polaren Kovalenz gegeneinander abgegrenzt.
    Additional Material: 7 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1155-1160 
    ISSN: 0044-2313
    Keywords: Tin tetrathalliumtritelluride ; lead tetrathalliumtritelluride ; preparation ; crystal structure ; Cr5B3 type ; In5Bi3 type ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Crystal Structure of SnTl4Te3 and PbTl4Te3.We describe the synthesis and crystal structure of two ternary derivatives MTl4Te3 of the parent phase Tl5Te3. Both the derivatives, SnTl4Te3 and PbTl4Te3, crystallize with the In5Bi3 type of structure: space group I4/mcm, Z = 4. The cell constants of SnTl4Te3(PbTl4Te3) are as follows: a = 8.819(2) Å (8.841(2)Å), c = 13.013(3) Å (13.056(3) Å), c/a = 1.47 (1.48). Short M—Te distances of 3.25 Å (3.26 Å) are obtained in ∞1[MTe2/2] chains, which run along [001]. The M atoms are further surrounded by additional tellurium atoms in such a way that octahedra occur, which share common vertices to build up a three dimensional infinite network ∞3[MTe6/2]. The remaining thallium atoms span cubes around the octahedra: ∞3[MTe6/2]Tl8/2 = MTl4Te3.An alternative structure description takes into account bent fragments Tl2Te with Tl—Te distances of 3.15 Å (3.17 Å) as the constitutional elements of M-centered, slightly distorted rhombic dodecahedra as the only polyhedra of the structure. Along [001] they share common vertices, whereas in the tetragonal a-a-plane they are interconnected via common faces.
    Notes: Die Darstellung und die Kristallstruktur der zwei ternären Abkömmlinge SnTl4Te3 und PbTl4Te3 werden beschrieben. Beide kristallisieren isotyp zu ihrer Mutterphase Tl5Te3 im In5Bi3-Typ, der seinerseits eine isopuntale Unterfamilie des Cr5B3-Typs bildet. Die Raumgruppe ist I4/mcm, die Zahl der Formeleinheiten beträgt 4. Die Gitterkonstanten für SnTl4Te3(PbTl4Te3) lauten a = 8,819(2) Å (8,841(2) Å), c = 13,013(3) Å (13,056(3) Å), das c/a-Verhältnis beträgt 1,47 (1,48).In zwei Fragmenten des dreidimensionalen Verbandes treten kurze M—Te—Abstände auf (M = Sn, Pb, Tl). Je nachdem, welchem Fragment man mehr Aufmerksamkeit schenkt, sind zwei alternative, aber gleichwertige Strukturbeschreibungen möglich: Die erstere lehnt sich an die bei der Mutterphase Tl5Te3 gewählte an und betont die kurzen Sn—Te— bzw. Pb—Te—Abstände in den parallel zur [001]-Richtung verlaufenden linearen Ketten ∞1[MTe2/2](Sn—Te: 3,25 Å, Pb—Te: 3,26 Å). Die M-Atome der Ketten werden durch weitere Tellur-Atome zu einem allseits spitzenverknüpften Oktaederverband ∞1[MTe6/2] komplettiert. Die Oktaeder werden würfelförmig von den Thallium-Atomen umgeben: ∞3[MTe6/2]Tl8/2 = MTl4Te3.De zweite betont die gewinkelten Fragmente Tl2Te(Tl—Te in SnTl4Te3: 3,15 Å, Tl—Te in PbTl4Te3: 3,16 Å). Die Tl2Te-Fragmente sind Teile verzerrter Tl2Te2-Rhomben. Diese Rhomben bauen M-zentrierte Rhombendodekaeder auf (M = Sn, Pb), die das einzige zum Strukturaufbau nötige Polyeder sind.
    Additional Material: 3 Ill.
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