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  • 1
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Pulses of 193 nm radiation from an ArF laser with energies exceeding 0.5 J/cm2 have been shown to modify 40–60 nm thick layers of {100} and {110} oriented diamond surfaces. These layers exhibit highly anisotropic electrical and optical properties which have principal in-plane axes along the 〈110〉 directions. The minimum resistance is (4–10)×10−4 Ω cm, and minimum in the optical transmittance and maximum in the reflectance occur when the electric field vector of the incident polarized light is aligned along the low resistance direction. Transmission electron microscopy indicates that the modified layer primarily consists of unidentified graphite-like carbon phases embedded in diamond. The first-order electron diffraction spots correspond to lattice spacings of 0.123, 0.305, and 0.334 nm. The modified layer is stable at 1800 °C, forms ohmic contacts to type IIb diamond, and supports epitaxial diamond growth.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 1631-1633 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The deposition of SnO2 films has been demonstrated using an ArF (193 nm) excimer laser to drive the photochemical reactions of mixed SnCl4 and N2 O vapors. Without any annealing, films 100 nm thick grown on room-temperature substrates have resistivities as low as 0.04 Ω cm. The optical band gap of 3.20 eV and transmission cutoff wavelength of 330 nm compare favorably with the best films obtained using alternate higher temperature techniques. Subsequent annealing does not increase the film's conductivity. Selective area growth of 10-μm-wide lines has been performed using proximity printing. The maximum temperature excursion during the laser pulse is estimated to be 300–400 °C.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 44 (1988), S. 91-93 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Langenbeck's archives of surgery 369 (1986), S. 411-414 
    ISSN: 1435-2451
    Keywords: Splenectomy ; Expert opinion ; Splenektomie ; Begutachtung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Begutachtung nach Milzverlust: 1. Bei Milzverlust nach Trauma besteht ein 60fach höheres Infektionsrisiko. 2. Die Sepsisincidenz beträgt 1,05%, die Mortalität 0,5%. 3. Milzerhaltende Operationen sichern die Immunkompetenz nur bei mindestens 30 % erhaltener Milzmasse. 4. Die MdE beträgt im 1. Jahr nach Splenektomie 30%. später 10% bei zusätzlichen Komnlikatinnen
    Notes: Summary Expert opinion after splenectomy: 1) In splenectomized patients after trauma the risk of infection is up to 60 times increased. 2) The incidence of sepsis amounts to 1.05, mortality to 0.5%. 3) Spleen-preserving surgery guarantees an immunocompetence only if at least 30 % of the spleen is preserved. 4) The professional performance of people having undergone splenectomy is restricted by 30% during the first year (“MdE” of 30%), later by 10% if additional complications occur.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Langenbeck's archives of surgery 371 (1987), S. 71-84 
    ISSN: 1435-2451
    Keywords: Aortic rupture ; Ischaemic paraplegia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Die traumatische Ruptur der thorakalen Aorta kommt in erster Linie durch Decelerationstraumata im Straßenverkehr, bevorzugt bei Autoinsassen zur Beobachtung. Rund 80% der Betroffenen sterben akut an der Unfallstelle. Bei 29 Verletzten (1973–1986), die noch lebend in klinische Behandlung kamen, war regelmäßig der Aortenisthmus betroffen, 28mal in Form einer gedeckten Ruptur; nur einmal lag eine freie Ruptur in die linke Pleurahöhle vor. 25 (85%) der Verletzten waren Polytraumatisierte mit gravierenden Begleitverletzungen des Schädels, der übrigen Thoraxorgane, des Abdomens und der Extremitäten. Ein Sitzgurt bot keinen Schutz vor der Decelerationsverletzung der Aorta: Er reduzierte aber vor allem begleitende Kopf- und Bauchverletzungen. 2. Das seither gültige Postulat, jede nachgewiesene traumatische Aortenruptur unmittelbar nach Diagnosestellung sofort chirurgisch zu korrigieren, ist heute als überholt anzusehen: Ergibt sich arteriographisch und klinisch der Befund einer gedeckten Aortenruptur, so ist vor allem beim Polytraumatisierten die Korrektur der Aortenläsion mit aufgeschobener Dringlichkeit, d. h. in einem Zeitabstand von etlichen Stunden bis zu einigen Tagen, das überlegene Behandlungsprinzip. Bei einem expektativen Vorgehen mit primärer Schockbehandlung unter intensivmedizinischer Überwachung und in Operationsbereitschaft ist es bei keinem dieser Patienten (n = 12) zu einer sekundären freien Aortenruptur gekommen. Dieses Risiko ist seither weit überschätzt worden. Gelingt es, die Kreislaufverhältnisse evtl. durch vorausgehende operative Ausschaltung anderer Blutungsquellen (Milz, Leber, Gliedmaßenarterien) zu stabilisieren, so läßt sich die Operationsletalität und das Paraplegierisiko der nachfolgenden Versorgung der Aortenverletzung drastisch reduzieren, nämlich auf 25% bzw. unter 10%. 3. Die Sofortversorgung der Aortenruptur mit ihrer unvergleichbar höheren Operationsletalität (47%) und extrem hohen Paraplegierate (35%) kann aus heutiger Sicht auf wenige Ausnahmefälle beschränkt werden, bei denen die Aortenverletzung den Hauptblutungsherd darstellt (freie Ruptur). Als Methode der Wahl ist das Clamp-repair-Prinzip mit direkter Gefäßnaht evtl. nach vorheriger Mobilisation des Aortenbogens anzusehen. Die transvenöse DSA leistet heute in jedem Verdachtsfalle einen entscheidenden Beitrag zur Frühdiagnose und zur indikatorischen Entscheidung über das chirurgische Vorgehen (Gefäßrekonstruktion mit aufgeschobener Dringlichkeit oder als Sofortmaßnahme).
    Notes: Summary 1) Traumatic rupture of the thoracic aorta is most frequently caused by a traffic accident with deceleration. Approximately 80% of these patients die immediately. In 29 patients (1973–1986) reaching surgical treatment, all aortic lesions were located at the aortic isthmus (28 covered and 1 free rupture). 25 (86%) of them had serious associated injuries of the head, other thoracic or intraabdominal organs and/or the extremities. A seat belt could not prevent the deceleration injury of the aorta but reduced associated injuries of the head and the intraabdominal organs. 2) The widely accepted surgical rule that every diagnosed traumatic aortic rupture should have an immediate surgical repair is no longer acceptable. In all patients with a clinically and angiographically stable covered rupture of the aorta with serious associated injuries and symptoms of shock the surgical treatment of the aortic lesion should be untertaken with delayed emergency after some hours or several days. This changed surgical concept is based both on the rarity of secondary free rupture of the aortic lesion and on the chance to stabilize the circulatory condition by a primary shock treatment including the surgical elimination of other sources of blood loss. The group with such a delayed aortic vascular repair (n = 12) showed a remarkably improved outcome with reduced operative mortality and reduced risk of paraplegia (47% vs. 25% respectively 35% vs. ca. 10%). None of these patients with a delay up to 17 days for vascular repair developed a secondary free aortic rupture. Up to recently this risk has been obviously overestimated on the basis of earlier studies in the sixties. 3) The immediate repair of the aortic rupture with its high operative mortality and high rate of ischemic paraplegia can be restricted to a few exceptional cases with a secondary free rupture in the hospital. The transvenous DSA is the best approach for an early diagnosis and for the surgical decision to perform vascular repair immediately or with delay.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1435-2451
    Keywords: Oxygen radicals ; Reperfusion ; Liver ; Rat ; Electron-spin-resonance ; Spin trap PBN
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Freie Sauerstoffradikale werden als Kausalfaktor in einer Vielzahl von Erkrankungen, u. a. auch im postischämischen Reperfusionsschaden vermutet. Der Nachweis freier Radikale ist schwierig and wird in der Regel indirekt geführt. Mit der Elektronenspinresonanz gelingt es, in einem Tiermodell mit Leberischämie und -reperfusion das Auftreten von Radikalen im Lebergewebe nach 60minütiger Leberischämie nachzuweisen. Bereits nach 5minütiger Reperfusion treten vermehrte Radikale auf. Das Maximum der Radikalentstehung wird nach 15minütiger Reperfusion erreicht, wobei die übermäβige Produktion von freien Radikalen für mindestens 45 min Reperfusion nachweisbar bleibt. Soll these Kausalkette des postischämischen Reperfusionsschadens unterbrochen werden, müssen Fängermecha-nismen bereits zu Beginn der Reperfusion in ausreichender Konzentration im Gewebe vorhanden sein.
    Notes: Summary The generation of free oxygen radicals is presumed to be a pathogenetic principle in various conditions, primarily in postischemic reperfusion injury. Their assessment is difficult. ESR is an excellent tool to assess free radicals directly. 1n an experimental model of rat liver ischemia and reperfusion the increased generation of free radicals during reperfusion in liver tissue could be demonstrated after 60 min of liver ischemia. Elevated production rates of radicals could be detected after 5 min of reperfusion for at least 45 min with a maximum after 15 min of reperfusion. Scavenging of these radicals has to start in the very beginning of reperfusion.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 69 (1991), S. 1095-1098 
    ISSN: 1432-1440
    Keywords: Liver ; Warm ischemia ; Reperfusion ; Oxygen radicals ; Allopurinol ; Deferoxamine ; Iron ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The generation of free oxygen radicals is presumed as a substantial pathogenetic principle in reperfusion injury. Although demonstrated in gut, muscle and kidneys its role in liver reperfusion injury is still under investigation. In an experimental rat model of warm liver ischemia of 60 min and 8 h reperfusion electron resonance spectroscopy assessed the increased generation of free radicals in early reperfusion period, leading to a decrease of polyunsaturated free fatty acids in liver tissue within 15 min of reperfusion. Histologically, single cell death, local and patchy necrosis of hepatic lobuli could be observed after 8 h reperfusion (n=6). These histologic signs of liver injury could be attenuated by administration of superoxid-dismutase in combination with catalase but not by allopurinol. Best results could be obtained by deferoxamine. This indicates that increased generation of free oxygen radicals in reperfusion is not caused by the known conversion of xanthine-dehygrogenase to -oxidase but is mediated by an increased generation of hydroxyl-radicals, which can be scavenged by deferoxamine.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 89 (1992), S. 289-296 
    ISSN: 1434-6036
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Starting from a system of nonlinear transport equations describing the dynamics of a single breathing current filament, e.g. in the regime of low-temperature impurity breakdown in semiconductors, we introduce a simple nonlocal coupling mechanism for the description of two breathing filaments. It is based on the interaction of the two filaments via the external load circuit. We find that the model describes a selection mechanism allowing the survival of the originally larger filament only. Therefore, it can be considered a generalization of Ostwald ripening in thermodynamic equilibrium. Although the breathing instability is suppressed asymptotically, transient symmetric breathing of the filaments is possible due to a periodic repeller.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 32 (1992), S. 1595-1599 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Irradiation of certain organosilicon polymers with a 193-nm excimer laser forms a latent image that contains increased amounts of oxygen. Patterning is achieved by dry development in an HBr plasma, where the oxidized polymer etches more slowly than the unexposed areas. With these polymers as the top layer in a bilayer resist scheme, 0.2 μm resolution has been demonsrated and resist sensitivities less than 50 mJ/cm2 have been achieved. Three classes of organosilicon layers have been investigated: polysilynes; polysilanes, in particular poly(phenylmethyl) silane; and a plasma-deposited polymer derived from tetramethylsilane (PPTMS). The PPTMS, when used with plasma-deposited planarizing layers, opens the possibility of an all-dry, cluster-tool-compatible lithographic cycle.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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