Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Amblyopia  (1)
  • Chemistry  (1)
  • Cushing's disease  (1)
  • 1
    ISSN: 1432-2013
    Keywords: Contrast sensitivity ; Spatial distortion ; Neural dysfunction ; Amblyopia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In this investigation contrast threshold measurements are compared with supra-threshold perception for a group of human amblyopes. The results indicate that human amblyopia involves, in some cases, not only loss of sensitivity but spatial distortion. Thus a new group of amblyopes can now be identified in which only distortion occurs. These results have important physiological implications for both the normal and abnormal visual systems. Neurophysiologists investigating visual loss from deprivation should assess whether similar distortions occur in animals. This question may hold the answer to whether the present animal models are relevant to the human condition.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1076
    Keywords: Growth hormone ; Cortisol ; Glucocorticoid therapy ; Cushing's disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cortisol and growth hormone (GH) secretion (spontaneous variations at night and the release induced by insulin hypoglycaemia) were investigated in 69 children and adolescents. Statistical analysis of approximately 600 pairs of cortisol and GH values in this study demonstrated that physiological fluctuations of cortisol do not alter GH secretion. A review of the literature shows that GH secretion is consistently depressed in Cushing's disease of central origin and in Cushing's syndrome due to adrenal carcinoma. When acutely administered, doses higher than 100 mg of cortisol (or equivalent amounts of other steroids) per adult are necessary to block GH secretion and the hormones have to be given several hours previously. In long-term steroid treatment, suppression of GH is observed in only 1 out of 3 patients. The effect apparently does not persist beyond elimination of the last dose, i.e. generally not longer than 12 to 24 h. These data can be taken as a rationale for intermittent or alternating dosage schedules, and for the use of short acting derivatives if long-term, high-dose steroid treatment is necessary in children. It remains to be established whether growth deficiency in exogenous hypercortisolism is due to suppression of GH secretion, decreased production of somatomedins, direct antagonism of the action of somatomedins on growing cartilage, or a combination of these mechanisms.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 421 (1976), S. 61-70 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of a Hydroxostannate: Copperdiammine-hexahydroxostannate Cu(NH3)2Sn (OH)6Single crystals of Cu(NH3)2, Sn(OH)6, have been prepared by the reaction of K2Sn(OH)6, with Cu(NO3)2· 3 H2O in aqueous solution of NH3. The complex crystallizes in the triclinic space group P1 with a = 5.643(2) Å, b = 6.621(2) Å, c = 4.885(2) Å, α = 91.83(3)°, β = 93.58(3)°, γ = 107.69(3)° and Z = 1. The crystal structure has been solved by Pattersonsyntheses. The hydrogen atoms could be localized by difference Fourier syntheses. The structure contains infinite chains of alternating Sn(OH)6- and Cu(OH)4(NH3)2-octahedra linked parallel to the b-axis by common edges. The chains are connected by hydrogen-bonding to their neighbouring chains. An almost regular octahedra is found for the coordination of the Sn-atoms, whereas the Cu(OH)4(NH3)2-octahedra show a pronounced (4+2)-distortion with two OH—-groups in the axial positions in a distance of 2.627(2) Å. The structure can also be described in terms of slightly distorted hexagonal close packed layers of oxygen and nitrogen. The metal atoms occupy 1/4 of the octahedral sites in an ordered arrangement. Thus the structure bears a close relationship to thc layer structure of α-NbI4.
    Notes: Einkristalle von Cu(NH3)2Sn(OH)3 wurden durch Umsetzung von K2Sn(OH)6 mit Cu(NO3)2 · 3 H2O in wäßriger ammoniakalischer Lösung gewonnen. Die Verbindung kristallisiert in der triklinen Raumgruppe P1 mit a = 5,643(2) Å, b = 6,621(2) Å, c = 4,885(2) Å, α = 91,83(3)°, β = 93,58(3)°, γ = 107,69(3)° und Z = 1. Die Kristallstruktur wurde aus Pattersonsynthesen aufgeklärt, und aus Differenzfouriersynthesen konnten auch die Positionen der Wasserstoffatome ermittelt werden. Die Struktur enthält unendliche Ketten von alternierenden Sn(OH)6-und Cu(OH)4(NH3)2-Oktaedern, welche parallel zur b-Achse über gemeinsame Kanten verknüpft sind. Die Ketten sind durch Wasserstoffbrückenbindungen mit ihren Nachbarketten verknüpft. Während das Sn(OH)6-Oktaeder nahezu regulär gebaut ist, zeigt das Cu(OH)4(NH3)2-Oktaeder eine ausgeprägte (4+2)-Verzerrung mit zwei OH--Gruppen in den axialen Positionen in einem Abstand von 2,627(2) Å. Die Struktur kann auch als Folge von leicht verzerrten hexagonal dichtest gepackten Schichten von Sauerstoff und Stickstoff beschrieben werden, wobei die Metallatome 1/4 der Oktaederlücken geordnet besetzen. Sie zeigt eine enge Verwandtschaft mit der Schichtstruktur des α-NbJ4.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...