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  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 3438-3442 
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: The superconducting super collider rf-driven volume ion source routinely provided 35 kV, (approximately-greater-than)30 mA H− beams with normalized rms emittances (cursive-epsilonn-rms) 〈0.1 π mm mrad. The source was typically operated with a 100 μs beam pulse width at a 10 Hz repetition rate. To enhance H− output, the ion source was modified to accommodate a set of cesium dispensers so that a trace amount of cesium could be introduced into the plasma grid collar. A plasma grid heater element controls the temperature of the cesiated surfaces and the rate of cesium dispensation. Beam currents in excess of 100 mA and electron to H− current ratios close to one have been observed. Emittance measurements at 70 mA suggest a 20% increase over uncesiated emittance values. Improvements in the beam emittance are fully expected when the extraction optics are optimized. This enhanced, very reliable source is a strong candidate for high current H− accelerators. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 65 (1994), S. 1173-1175 
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: The Superconducting Super Collider (SSC) ion source is required to provide a 30 mA H− beam at 35 keV with a normalized rms emittance (εn-rms) of less than 0.18 π mm mrad. An rf-driven volume source was chosen for the commissioning of the SSC linear accelerator (Linac). The divergent ion source output beam is matched into the radio frequency quadrupole accelerator (RFQ) by an electrostatic low-energy beam transport (LEBT). The SSC Linac injector (consisting of ion source, LEBT, and RFQ) is required to provide 25 mA of H− beam (pulse width of 9.6–35 μs at 10 Hz repetition rate) at 2.5 MeV with transverse normalized rms emittance (εt-n-rms) of less than 0.2 π mm mrad and longitudinal normalized rms emittance (εl) of less than 0.82×10−6 eV s. The performance of our rf volume source and initial experimental results from the SSC injector are discussed.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 67 (1996), S. 1318-1320 
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: To evaluate the performance of a high current H− rf-driven volume ion source, the Superconducting Super Collider ion source was modified to accommodate a set of cesium dispensers so that a trace amount of cesium could be introduced into the plasma grid collar. A plasma grid heater element controls the temperature of the cesiated surfaces and the rate of cesium dispensation. With this modification, beam currents in excess of 100 mA and electron to H− current ratios close to one have been observed. In contrast, the uncesiated source provided 30 mA of H− beam with an e/H− ratio ≥25. In both cases the source was operated with a 100 μs beam pulse width at a 10 Hz repetition rate, and an extraction voltage of 35 kV. This cesium enhanced source is a strong candidate for use in high current H− accelerators. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 26 (1996), S. 0 
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background Enhanced skin mast cell releasability of histamine, increased production of histamine releasing factor (HRF), and cutaneous inflammatory process are the hallmarks of chronic idiopathic urticaria (CU). Although H1-antihistamines are known to alleviate the symptoms effectively in most cases, systemic corticosteroids (CS) are given in more resistant patients. Their mode of action remains a matter of controversy.Objectives In the present study, the effects of a 7-day course of CS or placebo on histamine content and HRF production iti non-lesional skin of 19 CU patients were examined.Methods Using the skin chamber technique, HRF production and histamine content were assessed in normal-appearing skin of patients with CU over a 2-h observation period. Those two parameters were measured before and after treatment, in a double-blind fashion.Results No significant changes occurred in any parameters after placebo treatment. In contrast with this, significant decrease of HRF activity was observed after 1 week of oral methylprednisolone while no change was documented for histamine secretion. Conclusion These data suggest that CS therapy improves symptoms of CU in association with a decreased production of HRF in uninvolved skin.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background and objectives The determinants of variability in the clinical expression of atopy are still to be documented. The goals of this study were to determine, in subjects with a clinical diagnosis of symptomatic asthma or rhinitis, what is the possible contribution of different types of indoor and outdoor allergens to the development of their disease, by looking at the prevalence and degree of sensitization to these allergens according to age and gender.Subjects and methods We analysed allergy skin prick tests to common airborne indoor and outdoor allergens in 3371 consecutive patients, grouped according to diagnosis of allergic asthma, rhinitis, or both. For each of these three groups, we calculated the prevalence of sensitization to indoor/outdoor allergens, the atopic index (Al), the number of positive responses to allergy skin prick test and the mean wheal diameter (MWD) of these responses.Results The prevalence of atopy and the values of Al and MWD peaked in subjects aged 16 to 25 years, declining afterwards; in subjects ± 18 years old, atopic indices were slightly higher in men than in women. In atopic subjects, the prevalence of sensitization was, in decreasing order: housedust (84.2%), cat hair-epithelium (76.5%), dog hair-dander (63.0%), house dust mite (54.2%), grasses (51.9%), trees (47.2%) and ragweed pollens (44.9%) and finally, moulds (25.4%). Among subjects sensitized only to outdoor allergens (n= 195), 73.8% had a rhinitis, 11.8% had asthma and 14.4% had both diagnoses; for those sensitized only to indoor allergens (n= 710), these values were respeetively 48.6, 24.5 and 26.9%, and for those sensitized to both indoor and outdoor allergens (n= 1793), the comparable values were 55.5, 14.6 and 29.9%.Conclusion These data show that in our population of subjects with respiratory allergic symptoms, indoor allergen sensitization is strongly associated with asthma, while exclusive sensitization to pollens is associated primarily with rhinitis. Sensitization was more prevalent for indoor allergens than for outdoor allergens in all groups determined according to diagnosis or age. Indices of atopy were higher in men in the group ± 18 years old. Prevalence and degree of sensitization were shown to peak in young adults, regardless of the allergen, and to diminish with age. This study stresses the role of indoor allergens in the development of asthma and shows the variability of allergic manifestations according to the type of sensitization.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 23 (1993), S. 0 
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The role of IL-4 on IgE synthesis has been well established. IL-4 has been shown to promote IgE production by B cells from atopic and non-atopic donors. In this study, the effects of natural exposure to pollens on IL-4-indueed IgE synthesis by peripheral blood mononuclear cells of atopic and non-atopic donors were examined. The results confirm production of IgE in an IL-4 dose-dependent manner by PBMC cultures of these two groups. When cultures were performed out of the pollen season, following stimulation by IL-4, no significant difference was observed between the levels of IgE produced by PBMC of atopic and non-atopic donors. In contrast, upon natural exposure to pollens, significant higher levels of IgE were measured in the atopic group than in the non-atopic one. These results show that the policn season infiuences the IL-4-induced IgE synthesis by PBMC of allergic patients and are in keeping with seasonal rise of specific IgE antibodies.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 51 (1996), S. 0 
    ISSN: 1398-9995
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Mometasone furoate aqueous nasal spray (Nasonex®) was compared with beclomethasone dipropionate (BDP) aqueous nasal spray in a double-blind, randomized, placebo-controlled, double-dummy, parallel-group study of adults with moderate to severe seasonal allergic rhinitis. Patients allergic to at least one tree and/or grass aeroallergen received one of the following regimens for up to 4 weeks: mometasone furoate 100 pg once daily [OD] (n = 126) or 200 μg OD (n= 126), BDP 200 μg twice daily (n = 126), or only placebo spray (n= 123). Physician-rated nasal and total symptom scores. and global evaluation of overall condition and therapeutic response by physicians and patients, showed that the three active treatments were equally effective, and all three were significantly superior to placebo at most time points. Overall, mometasone furoate 200 μg OD demonstrated somewhat greater numerical, but not statistical, superiority to mometasone furoate 100 μg OD at the earliest evaluation time poinl. At the end of treatment, complete or marked relief was obtained in 77% of patients with mometasone furoate 100 pg/day, 79% with mometasone furoate 200 pg/day, and 74% with BDP, compared with 54% of placebo vehicle control patients. Mometasone furoate and BDP were equally well tolerated. It was concluded that mometasone furoate adequately controls symptoms of moderate to severe seasonal allergic rhinitis, offers the advantage of OD treatment, and is well tolerated.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 426 (1995), S. 523-528 
    ISSN: 1432-2307
    Schlagwort(e): Von Hippel-Lindau disease ; Neuroendocrine tumour ; Electron microscopy ; Flow cytometry ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A 21-year-old woman with a family history of von Hippel-Lindau disease presented with a mass in the head of the pancreas. Light microscopic features of the tumour suggested neuroendocrine differentiation and although it displayed positive immunostaining for the antigens expected in a neuroendocrine neoplasm, S-100 staining was also present. This unusual feature prompted further evaluation by routine and post-embedding protein-A gold immunoelectron microscopy, which demonstrated the presence of neuroendocrine granules. Tumour cell DNA content was normal by flow cytometry. Although this patient exhibited no other signs of von Hippel-Lindau disease, the presence of a pancreatic tumour with neuroendocrine differentiation demonstrated that she was affected. Future surveillance and genetic counselling will be influenced by this diagnosis.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1432-1238
    Schlagwort(e): Left ventricular function ; Weaning ; Inspiratory pressure support ; Chronic obstructive pulmonary disease ; Coronary artery disease
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Objective Determine the evolution of left ventricular ejection fraction during weaning. Design Prospective study. Setting Intensive care unit of a university teaching hospital. Patients and participants 12 consecutive mechanically ventilated patients, without documented coronary artery disease, suffering from acute exacerbation of chronic obstructive pulmonary disease and able to be weaned. Measurements and results Left ventricular ejection fraction was determined during mechanical ventilation, inspiratory pressure support (10 cmH2O) and spontaneous ventilation with constant inspiratory oxygen fraction using technetium99m radionuclide angiography. Spontaneous ventilation induced a significant decrease in left ventricular ejection fraction from 54.5±12.4 to 47.0±13% (p〈0.01). Inspiratory pressure support induced a slight but non-significant decrease in left ventricular ejection fraction from 55.0±12.1 to 50.3±12.4%. Left ventricular ejection fraction was homogeneously reduced by spontaneous ventilation without patent regional wall motion abnormalities of the left ventricle. Myocardial201thallium imaging performed 15 min after weaning showed a normal perfusion in the left ventricle anterior and posterior free wall. Conclusion Weaning of patients suffering from chronic obstructive pulmonary disease without coronary artery disease induced a significant reduction in left ventricular ejection fraction. The non significant decrease in left ventricular ejection fraction observed with inspiratory pressure support suggested that our results might be explained by a weaning induced increase in afterload.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Journal of thermal analysis and calorimetry 38 (1992), S. 989-996 
    ISSN: 1572-8943
    Schlagwort(e): aerospace industry ; DSC ; metal matrix composites (MMC)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Metallmatrixverbundwerkstoffe (MMC) sind für die Raumfahrtindustrie von großem Interesse, insbesondere zum Bau thermisch-struktureller Komponenten ist es wichtig, Methoden zur Verfügung zu haben, die leicht und einfach zur Charakterisierung der mechanischen Festigkeit der Materialien benutzt werden können. Es wurde gezeigt, daß DSC es ermöglicht, die Kohäsionsenergie im Fiber/Matrix-Grenzflächengebiet eines mit SiC-Whiskern verstärkten Aluminiumverbundstoffes quantitativ zu bestimmen. Diese Kohäsionsenergie ist abgängig vom Verstärkungsgrad bezogen auf die Matrixfestigkeit und berücksichtigt sowohl die chemischen als auch mechanischen Eigenschaften der Kohäsion im Fiber/Matrix-Grenzflächengebiet. In jedem Falle bedarf diese Methode einer systematischen Kalibrierung anhand von Test der mechanischen Eigenschaften.
    Notizen: Abstract The metal matrix composites (MMC) being of very high interest for the aerospace industry, particularly to build up thermal-structural components, it is important to have available methods which are easy and simple to conduct for characterization of the mechanical strength of the material. This study shows that the differential scanning calorimetry (DSC) may enable us to quantify the energy of cohesion in the fiber/matrix interface area of an aluminium composite reinforced by SiC whiskers. The energy of cohesion is dependent on the state of reinforcement compared to the matrix strength and take into account both chemical and mechanical characteristics of the cohesion in the fiber/matrix interface area. However, this method would require a systematic calibration based on tests of mechanical characteristics.
    Materialart: Digitale Medien
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