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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 4894-4896 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The dielectric function of thin-film hydrogenated amorphous silicon (a-Si:H) grown on fused silica at different substrate temperatures has been investigated by spectroscopic ellipsometry. An improved interpretation of the ellipsometric data is based on a tetrahedron model that takes into account the influence of hydrogen incorporation in the amorphous network. It is shown that the film density can be derived from an accurate data interpretation, whereas the maximum value of the imaginary part of the dielectric function ε2max and the void volume fraction are not proportional to the density of a-Si:H films.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of pineal research 14 (1993), S. 0 
    ISSN: 1600-079X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: The effect of exogenous melatonin on the adrenocortical axis was studied by determining serum corticosteroid and adrenocorticotrophic hormone (ACTH) levels under basal and stressed conditions in intact, pinealectomized, and adrenalectomized mature male rats. A direct interrelationship between pineal/melatonin and the adrenal cortex, dissociated from the hypothalamic-pituitary axis, was established. Intraperitoneal injection of 100 μg melatonin brought about an elevated adrenocortical response recorded in the serum corticosteroid levels 15 hr afterwards. This effect could be demonstrated only at the beginning of the photophase, when physiological levels of corticosteroids and ACTH are at their lowest daily levels. The pattern of this reaction is different from those caused by stressors such as ether or hypoglycemic reagents, and did not occur in pinealectomized animals although the daily rhythm of corticosteroids and ACTH persisted. No effect on ACTH was evident in intact or adrenalectomized rats, where the serum levels remained unchanged. Moreover, the corticotrophin releasing factor (CRF) content of the median eminence was not affected by melatonin.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 283 (1980), S. 58-60 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Lovelock2 first reported the presence of methyl chloride in the atmosphere at the 1-2 p.p.b. level (1 p.p.b. = 1 part in 109 by volume) and showed that its concentrations were highest in air whose origins were oceanic rather than continental. Measurements in seawater confirmed that the ocean could ...
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 384 (1980), S. 203-206 
    ISSN: 1432-2013
    Keywords: Nephron epithelia ; Na−K-ATPase ; Aldosterone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Aldosterone, when added in vitro to defined nephron segments, dissected from adrenalectomized rabbits, restores the depressed Na+−K+-ATPase activity in the thick ascending limb of the loop of Henle and in the cortical collecting tubule within 1 h of incubation. The direct effect is specific and, as demonstrated for the cortical collecting tubule, dose-dependent. The time course of aldosterone-mediated Na+−K+-ATPase activation is compatible with the conjecture of changes in the enzyme lipid environment.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-1440
    Keywords: Heart failure ; Idiopathic dilated cardiomyopathy ; Human myocardium ; Positive inotropic agents ; Force-frequency relationship ; Calcium homeostasis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In isolated papillary muscle strips from nonfailing donor hearts (NF) and from the hearts of patients with dilated cardiomyopathy with severe heart failure (NYHA IV), the force-frequency relationship was studied. Experiments were performed under basal conditions and in the presence of 0.01 μM or 0.1 μM isoprenaline and 0.02 μM ouabain. In NF, there was a positive inotropic effect following an increase of the stimulating frequency, whereas in NYHA IV, the force gradually declined under these conditions. Low concentrations (0.01) μM of isoprenaline prevented the negative inotropic effect in NYHA IV, whereas at 0.1 μM the mechanical function deteriorated in NF and NYHA IV. Ouabain had no effect on the force-frequency relationship compared to basal conditions. It is concluded that a reduction of high frequencies does improve the contractility in the failing myocardium. It is not unreasonable to speculate that this mechanism might be involved in the beneficial effects of drugs which reduce the heart rate, such as β-adrenoceptor antagonists and cardiac glycosides, in the condition of congestive heart failure in which the sympathetic tone is high.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 179 (1996), S. 245-254 
    ISSN: 1432-1351
    Keywords: Bat ; Orientation ; Vision ; Echolocation ; Cumulative navigation error
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The orientation behaviour of bats (Phyllostomus discolor, Phyllostomidae), flying inside an octagonal “roost-like” chamber (ø: 100cm; h: 150cm) was examined. It has been shown that the bats begin turning manoeuvres during flight by turning their head towards the direction they intend to proceed to. During early phases of the flights, cumulative navigation errors were evident, indicating that endogenous spatial information plays a major role in the orientation of the bats. During later phases of the flight this error is diminished again. So it can be concluded that the bats start to use exogenous spatial information for orientation while approaching the target. In order to investigate the relative importance of vision, echolocation and endogenous spatial information for approaching the roost, the landing lattices inside the test arena were changed for non-grid dummies. We found that: 1. combined visual and endogenous information are more important than echoacoustical cues, 2. the bats learned quickly to switch their orientation behaviour in order to get a better performance in avoiding the dummies, 3. the learning performance was influenced by the visual similarity of dummies and the real landing lattice.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Intensive care medicine 20 (1994), S. 278-281 
    ISSN: 1432-1238
    Keywords: Blood brain barrier ; Urapidil ; Serotonin-(5HT1A) ; Receptors ; Cerebrospinal fluid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective To determine the plasma and cerebrospinal fluid (CSF) levels of urapidil after i.v. administration and the effect on CSF serotonin and 5-hydroxyindoleacetic acid (5-HIAA) concentrations. Design Open, single-dose study. Setting Post-surgery following neurosurgical removal of the hypophysis (n=5) or aneurysm clipping (n=1). Patients 6 patients, aged 32–71 years, with intact bloodbrain barrier (BBB); 1 patient was studied twice. Interventions Single dose of 25 mg urapidil i.v. as prophylaxis of BP increase during extubation or as treatment of hypertensive episodes. Measurements and results Urapidil, serotonin and 5-HIAA were measured by HPLC in CSF during 8 h after urapidil administration. Urapidil was detected in CSF as soon as 5 min after injection in 3 patients. The concentration ratio of plasma/CSF after the distribution phase was about 5∶1. No significant effect on serotonin and 5-HIAA in CSF was seen. Conclusion After administration of a therapeutic dose, urapidil permeates the BBB and may interact with central 5-HT1A-receptors.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 54 (1998), S. 199-202 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: In this paper, a general method for generating quasiperiodic lattices is given. It is based on point multilattices which may be transformed into quasilattices in a new manner. A rounding operation allows the conversion of amassments of points in the multilattice into single points of a perfect quasicrystalline structure. Several examples are given.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a clinical study the participation of histamine in the allergenic response of patients with food allergy was investigated. The resting levels of gastric tissue and plasma histamines of 10 patients were slightly higher than the respective values of normal volunteers. 5 minutes after local intragastral allergenic provocation a decline of the mucosal histamine content of the allergen-treated area was noticed. Parallel investigations on the mast cell content of the stomach mucosa revealed a parallel decrease of theo-phthaldialdehyde stained cells, whereas the number of toluidine blue stained cells remained unchanged. These data are in accordance with an antigen-induced IgE-dependent liberation of the mast cell histamine stores.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Zeitschrift für Herz-, Thorax- und Gefässchirurgie 13 (1999), S. 133-138 
    ISSN: 0930-9225
    Keywords: Schlüsselwörter Computertomographie – Thorax – Interventionen – Schneid-Saug-Biopsie ; Key words Computer tomography – thorax interventions – carve-suction biopsy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Problem: An investigation into CT-controlled carve-suction biopsy for a histological clarification of indefinite intrathoracic masses. Materials and Method: 143 CT-controlled interventions were performed on 102 patients. For histological evaluation purposes, tissue was taken under application of the carva-suction biopsy method (16–18 gage). The lesions with a diameter of 5–70 mm were located in the mediastinum (25%), were close to the thoracic wall/pleural (40%) and intrapulmonary (35%). Results: 92.2% (94/102) of the interventions provided histologically utilizable material in at least one biopsy specimen. The clinical suspected diagnosis was confirmed 78 times (76.5%), while a different discase was evident 16 times (15.7%). In 8 cases, a diagnosis was not possible (7.8%). The total complication rate was 21.6%. The following were observed: 18 pneumothoraxes, 2 hemothoraxes, and 2 patients who demonstrated a hemoptysis. In 4/102 patients (3.9%) complications arose which had to be treated therapeutically. Two-sided complications were not observed. Conclusions: The CT-controlled carve-suction biopsy can be employed histologically to clarify indefinite intrathoracic findings with a high degree of certainty and justifiable complication rates. In addition to this, the minimally invasive procedure helps to reduce costs.
    Notes: Zusammenfassung Fragestellung: Bewertet wird die CT-gesteuerte Schneid-Saug-Biopsie zur histologischen Abklärung unklarer intrathorakaler Raumforderungen. Material und Methode: Bei 102 Patienten wurden 143 CT-gesteuerte Interventionen durchgeführt. Zur histologischen Beurteilung wurde Gewebe in Schneid-Saug-Biopsie-Technik (16–18 Gage) entnommen. Die Läsionen waren 5–70 mm groß, 25% lagen mediastinal, 40% thoraxwandnah/pleural und 35% intrapulmonal. Ergebnisse: 92,2% (94/102) der Interventionen erbrachten in mindestens einer entnommenen Gewebeprobe histologisch verwertbares Material. Die klinische Verdachtsdiagnose wurde 78mal (76,5%) bestätigt, 16mal (15,7%) wurde eine andere Erkrankung nachgewiesen. 8mal ließ sich keine Diagnose stellen (7,8%). Die Komplikationsrate betrug 21,6% (18 Pneumothoraces, 2 Hämatothoraces und 2 Patienten mit Hämoptoe). Bei 4/102 Patienten (3,9%) traten therapiebedürftige Komplikationen auf. Schlußfolgerungen: Mit der CT-gesteuerten Schneid-Saug-Biopsie lassen sich unklare intrathorakale Befunde mit hoher Treffsicherheit und vertretbaren Komplikationen abklären.
    Type of Medium: Electronic Resource
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