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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 1326-1332 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A compact fluorescence detector has been developed which allows to count slow, single Na atoms. By using glass fibers for the exciting and the fluorescence light we obtained free movability of the detector. The detection efficiency has been analyzed and optimized by an extensive investigation of all processes concerning the laser-induced fluorescence, especially the random walk of the atom, saturation effects, and optical pumping. Single atoms are identified by registration of photon bursts which stand out from the Poisson distributed background. An absolute calibration of the detection efficiency has been achieved by a time-resolved fluorescence measurement in combination with a corresponding Monte–Carlo simulation. Atomic fluxes well below 1 atom/s can be determined with an uncertainty of less than ±10%. Assuming a continuous flux of 1 atom/s with 25 m/s typically about 50% of these atoms are counted. The detector is an excellent tool for differential scattering experiments with slow atomic beams. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Nuclear Instruments and Methods 72 (1969), S. 353-354 
    ISSN: 0029-554X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Physics
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Optics Communications 73 (1989), S. 451-454 
    ISSN: 0030-4018
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Solid State Communications 59 (1986), S. 809-811 
    ISSN: 0038-1098
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Solid State Communications 43 (1982), S. 719-720 
    ISSN: 0038-1098
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physics Letters A 87 (1981), S. 130-132 
    ISSN: 0375-9601
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Nuclear Instruments and Methods 142 (1977), S. 353-355 
    ISSN: 0029-554X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Physics
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-0428
    Keywords: Simultaneous pancreas and kidney ; transplantation ; Reactive hyperaemia response ; Transcutaneous oxygen pressure measurement ; Laser speckle measurement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To evaluate the beneficial effect of pancreatic grafting on peripheral microcirculation and long-term clinical outcome, we compared data of 28 Type 1 (insulin-dependent) diabetic patients either given a pancreatic and kidney graft simultaneously or given a solitary kidney graft (n=17). Peripheral microcirculation was estimated by transcutaneous oxygen pressure measurement (including reoxygenation potential after blood flow occlusion) and erythrocyte flow / velocity by a non-contact laser speckle method. All the measured parameters showed significant differences between diabetic and control subjects in the mean follow-up time of 49 (simultaneous pancreas and kidney transplantation) and 43 (solitary kidney transplantation) months. The data from patients after simultaneous pancreas and kidney transplantation revealed an improvement of transcutaneous oxygen pressure measurement (rise from 46±2 mm Hg to 63±3 mmHg), reoxygenation time (fall from 224±12s to 114±6s) and laser speckle measurement (rise from 4.2±1.7 to 5.6±1.8 relative units). The control group with solitary kidney transplantation did not show a positive evaluation. Data from patients after simultaneous pancreas and kidney transplantation revealed an improvement in transcutaneous oxygen pressure measurement, reoxygenation time and laser speckle measurement whereas the control group with solitary kidney transplantation did not show a positive evaluation. Improved microcirculation was more pronounced in patients with better microvascular preconditions. The results confirm that diabetic microangiopathy is positively influenced by pancreatic transplantation.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Langenbeck's archives of surgery 375 (1990), S. 112-118 
    ISSN: 1435-2451
    Keywords: Pancreatitis ; Microcirculation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurde ein Modell etabliert, an dem gleichzeitig die Verdnderungen der Makro- und Mikrozirkulation des Pankreas gemessen werden können. Das Pankreas wurde dazu in situ isoliert. An diesem Modell wurde eine akute Pankreatitis Durch retrograde Infusion von Natrium-Taurocholat-Lösung (NaT) in den Pankreasgang ausgelöst. Durch ausreichende Fliissigkeitszufuhr wurde ein hypovoldmischer Schock verhindert. Die beobachteten Verdnderungen der hämodynamischen Parameter sind somit pankreatitisbedingt. Im Pankreatitismodell war intravitalmikroskopisch frühzeitig eine Permeabilitdtssteigerung fur Makromoleküle an der Pankreasoberfläche zu beobachten. Der Gefäßwiderstand des Pankreas blieb im Modell der bilidren Pankreatitis unverändert. Die Perfusionsausfälle in den Stasebereichen waren von einer Steigerung der funktionellen Kapillardurchblutung in den übrigen Bereichen begleitet. Aüßerdem war eine Abnahme der Sauerstoffausschöpfung des Blutes zu beobachten. Man kann somit von einer funktionellen Shuntdurchblutung sprechen. Die Organgesamtdurchblutung blieb in diesem Modell unverändert. Es ließen sich in diesem Pankreatitismodell somit die hdmodynamischen Zeichen einer echten Entzündung, Permeabilitätsstörung and Hyperdmie, nachweisen.
    Notes: Summary Measurements of pancreatic micro- and macrocirculation were performed to evaluate the pancreatitis-induced changes. Pigs were anesthetized and ventilated mechanically. Hypotension induced side-effects were avoided by adequate volume replacement. After laparatomy, splenectomy and gastroectomy the animals were enterotomized. Systemic hemodynamic parameters were monitored as well as pancreatic blood flow (Q), which was measured electromagnetically, and arterial and portal-venous blood gases. Pancreatic microcirculatory parameters were observed using fluorescence-videomicroscopy after i.v. administration of FITC dextran 150 and FITC labeled autologous erythrocytes. The pigs were randomly assigned to a control (n = 9) and a pancreatitis group (n=10), the later being induced by the retrograde infusion of sodium-taurocholate. Systemic and pancreatic macrohemodynamic parameters remained constant in both groups, except for avd02 and O2-consumption (O2-c) decreasing significantly in the pancreatitis group. At baseline 42% of all capillaries were perfused in both groups. In pancreatitis we detected focal areas with persistent stasis and areas which were continuously perfused. In these areas the portion of capillaries perfused by erythrocytes increased significantly to 67%. This was accompanied by an extravasation of FITC dextran. The finding of an unchanged Q beside reduced 02-c and avd02 during pancreatitis is explained by the changes in pancreatic microcirculation. Focal stasis was observed beside areas showing typical signs of an acute inflammation: increased macromolecular permeability and capillary recruitment, e.g. oedema and hyperaemia.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 21 (1991), S. 215-219 
    ISSN: 1434-6079
    Keywords: 32.80.P
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Controlled mode-locked laser cooling of sodium atoms has been demonstrated for the first time. The broadband laser spectrum covers most of the Doppler-broadened atomic resonance spectrum. Atoms of a broad velocity range are thus decelerated simultaneously. In order to stop this process at a defined atomic velocity a two-mode laser beam tuned to resonance with both sodium groundstate levels is copropagating with the atomic beam and counterpropagating to the mode-locked laser beam. In this optical molasses sodium atoms ofv=20 m/s have been piled up to densities of about 2·106 cm−3. The density dependence on variable laser parameters has been investigated systematically.
    Type of Medium: Electronic Resource
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