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  • 1980-1984  (3)
  • 23Na+,87Rb+, and14N NMR  (1)
  • Acute pancreatitis  (1)
  • Polymer and Materials Science  (1)
  • 1
    ISSN: 1572-8927
    Keywords: Quadrupole relaxation ; 23Na+,87Rb+, and14N NMR ; ion-solvent interaction ; asymmetry effects ; preferential solvation ; acetonitrile-water mixtures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Nuclear magnetic relaxation rates of23Na+,87Rb+, and14N in acetonitrile-water mixtures have been measured over the complete mixture range. The interaction of the quadrupole moment of ionic nuclei with electric field gradients is an excellent short ranged probe for the direct neighborhood of ions in solution. Thus the23Na+ and87Rb+ relaxation contains information about dynamics composition and symmetry of the inner solvation sphere in the mixed solvent. It was found that the relaxation rate of both ionic nuclei has an unexpected marked maximum in the acetonitrile (AN) rich region. The14N and2H relaxation rates of the solvent molecules revealed that the maximum could not be explained by dynamic effects. Further experimental results showed that it is caused by local symmetry changes. By measuring 1/T1 of the cationic nuclei in AN-H2O and AN-D2O it was possible for the first time to separate quantitatively asymmetry effects from selective solvation effects. It turned out that both cations are strongly preferentially hydrated. Comparison of the results of two approaches for the evaluation of the D2O-H2O isotope effect led to interesting hints concerning the location of the electric point dipole in acetonitrile molecules having contact with cations.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Langenbeck's archives of surgery 356 (1982), S. 141-149 
    ISSN: 1435-2451
    Keywords: Acute pancreatitis ; Computed tomography ; Ultrasound ; Operative treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die „stadiengerechte Therapie” der akuten Pankreatitis, die jedem Schweregrad der Erkrankung angemessen ist, besteht neben der konservativen Basistherapie und Intensivmedizin im richtigen Einsatz operativer Maßnahmen. Voraussetzung dafür ist die frühe Diagnose und Beurteilung des Schweregrades der akuten Pankreatitis. Neben klinischen und klinisch-chemischen Befunden und dem Verlauf unter konservativer Therapie ermöglichen die Sonographie und die Computer-Tomographie eine bessere Beurteilung der jeweiligen Verlaufsform. Die für die Klinik der Erkrankung so wichtigen morphologischen Veränderungen der Bauchspeicheldrüse und ihrer Umgebung werden durch diese neuartigen Untersuchungsmethoden transparenter. Wäh rend bei der leichten Pankreatitis die Sonographie als erstes morphologisches Untersuchungsverfahren eingesetzt wird, besteht bei den schweren Verlaufsformen eine klassische Indikation zur Computer-Tomographie. Durch Einsatz von Sonographie und Computer-Tomographie läßt sich die Indikation zur frühzeitigen oder verzögerten Operation der hämorrhagisch-nekrotisierenden Pankreatitis, die bisher nach klinischen Kriterien erfolgte, in den meisten Fällen exakter stellen.
    Notes: Summary Adequate stage-depending therapy of acute pancreatitis includes basic conservative treatment, intensive care measurements, and operative interventions depending on the grade of severity. Prerequisites are early diagnosis and accurate clinical assessment of the stage of severity. Beside clinical and laboratory findings, as well as the development of acute pancreatitis under conservative treatment, sonography and computed tomography allow a better prediction of the underlying morphological changes, thus leading to an exact staging of the patient's individual situation. Sonography is regarded a screening procedure of high accuracy in mild forms of acute pancreatitis. Computed tomography is the method of choice in all severe forms of this disease. The indication for immediate or delayed operative treatment of hemorrhagic necrotising pancreatitis, heretofore depending on clinical findings solely, is supported by these new-invasive diagnostic modalities.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Microvascular prostheses with three different inner surface structures were examined morphologically 1-18 months after implantation to evaluate the presence and structure of the neo-intima. Fibrous polyurethane tubes (length: 5-10 mm, inner diameter: 1.5 mm) were implanted in the rat abdominal aorta in group A with a fibrillar inner structure (pore sizes 20-50 m̈m), and in group B the inner fibrillar structure was coated with an impermeable continuous silicon sheet. Expanded polytetrafluorethylene vascular prostheses (length: 40 mm, inner diameter: 4 mm) were implanted in the dog carotid artery (group C). The specimens were examined by light microscopy and scanning electron microscopy. A continuous and permanent neointima was only found in the prostheses with the porous fibrillar inner structure (group A). The thin new lining sheet was well attached to the prosthetic wall by cellular protrusions. In the silicon-coated prostheses (group B) also a continuous neo-intima had developed which, however, was irregular, thicker, and not anchored to the prosthetic wall. The expanded polytetrafluorethylene prostheses (group C) showed also after 1 year only incomplete lining with a neo-intima. Fresh blood cell deposits could be observed in the unlined prosthetic wall. It is concluded that a continuous lining of vascular grafts with a thin neo-intima is only achieved if the cells invading the prostheses from the anastomotic areas can anchore their cytoplasmic protrusions onto an appropriately structured inner surface. If these anchoring facilities are not provided, the unattached neo-intima will thicken, interfering with the patency of these microvascular prostheses, or fragments of the neo-intima or alternatively mural thrombi may constantly strip off and embolize.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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