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  • 1
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 9 (1962), S. 0 
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
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  • 2
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Transient electroluminescence (EL) from single- and multilayer organic light-emitting diodes (OLEDs) was investigated by driving the devices with short, rectangular voltage pulses. The single-layer devices consist of indium-tin oxide (ITO)/tris(8-hydroxy-quinoline)aluminum (Alq3)/magnesium (Mg):silver (Ag), whereas the structure of the multilayer OLEDs are ITO/copper phthalocyanine (CuPc)/N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB)/Alq3/Mg:Ag. Apparent model-dependent values of the electron mobility (μe) in Alq3 have been calculated from the onset of EL for both device structures upon invoking different internal electric field distributions. For the single-layer OLEDs, transient experiments with different dc bias voltages indicated that the EL delay time is determined by the accumulation of charge carriers inside the device rather than by transport of the latter. This interpretation is supported by the observation of delayed EL after the voltage pulse is turned off. In the multilayer OLED the EL onset—dependent on the electric field—is governed by accumulated charges (holes) at the internal organic-organic interface (NPB/Alq3) or is transport limited. Time-of-flight measurements on 150-nm-thin Alq3 layers yield weak field-dependent μe values of the order of 1×10−5 cm2/Vs at electrical fields between 3.9×105 and 1.3×106 V/cm. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 2597-2599 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The method of low-temperature scanning laser microscopy is applied to visualize the resistive state in individual superconducting filaments extracted from (Bi, Pb)2Sr2Ca2Cu3O10+x/Ag tapes. This technique is capable of imaging the distributions of the critical currents over a sample. Using the nonbolometric response, a spatial resolution of about 1 μm is demonstrated for 10-μm-thick filaments. Some of the resistively visualized grain boundaries between crystallites show Josephson behavior. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Oxford, UK; Malden , USA : Blackwell Science Ltd
    Journal of fish biology 64 (2004), S. 0 
    ISSN: 1095-8649
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: By collecting and counting the number of sperm released during separate matings in three batches of zebrafish Danio rerio, aged 3–4, 4–5 and 5–6 months, males were observed to release sperm before the female started laying their eggs. After the female left the nest, the number and motility of sperm and life span of sperm of younger fish were higher than those of older fish in water samples collected under the nest and at the surface of the tank. Sperm were released in the form of sperm trails laid on the nest surface, subsequently active spermatozoa left the trails and moved in the water for several minutes. Sperm trails consisted of bands of viscous material in which the sperm were embedded. In most cases eggs were not laid directly over the sperm trail, suggesting that sperm may contact the eggs after the latter are released into the water. In all the three tested groups there was no significant difference (P 〉 0·05) between the number of sperm collected on some portions of the acetate sheets which lined the nest ceiling. This result demonstrated that the greater activity of younger fish accelerated the sperm dispersal in water. Male sperm duct glands, seminal vesicles, known to secrete mucosubstances are probably involved in the production of sperm trails. The possible influence of insemination on the mating style of zebrafish is discussed.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular medicine 40 (1962), S. 911-913 
    ISSN: 1432-1440
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Zusammenfassung Mit einer fluorimetrischen Methode wird durch Bestimmung von Dopamin nachgewiesen, daß der Herzmuskel des Meerschweinchens Dopa zu Dopamin decarboxylieren kann. Die Decarboxylase ist im Zellsaft lokalisiert. Ihre Aktivität ist gegenüber anderen Organen klein.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular medicine 42 (1964), S. 958-965 
    ISSN: 1432-1440
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Clinical experiences and experimental observations with a chemically new oral diuretic are described (MK 595, Ethacrynic acid). It belongs to the group of unsaturatedα-,β-ketonderivatives of phenoxyarylacetic acid. This diuretic substance was most effectful in healthy individuals and patients with cardiac and hepatogenic edema. Even in patients with edema refractory to the known diuretics (incl. spirolactone) a saliuresis could be obtained. The therapeutic dosis is 100–200 mg orally per day or every second day. Side effects are rare and of little importance. There is a linear relation between the sodium, potassium and chloride excretion in the urine and the dosis applied (50–350 mg). The rise of sodium and chloride excretion is most marked. The potassium diuresis ist also increased but to a lesser extent. The difference between the conventional diuretics and the new phenoxyarylacetic acid derivative consists in a marked H-ion excretion of the latter. This can be easily shown by an increased titration acidity, ammonium secretion and decreased pH in the urine. Bicarbonate diuresis is missing completely. This in contrast to chlorothiazide and chlorthalidone and to a lesser extent to hydrochlorothiazide. Under MK 595 therapy a hypochloraemia, hypokalaemia and a slight metabolic alkalosis are regularly noticed. Long term treatment with the new diuretic should be accompanied by potassium substitution. Clinically most interesting and important is the rapid action of the new diuretic when given orally. 30–60 min after application of 200 mg MK 595 the beginning of the diuresis can be noticed. The maximum effect is reached after 90–120 min and 8–12 hours later there is no more effect. In some studies there was a second peak in the diuresis 3 1/2 to 5 hours after application. On the basis of its mechanism and intensity of action this new diuretic is very useful in situations where the conventional diuretics or combination of diuretics have failed. The rapid onset of action could be useful in case of emergency (i.e. pulmonary edema).
    Notizen: Zusammenfassung Es werden klinisch-experimentelle Beobachtungen und therapeutische Erfahrungen mit einem chemisch neuartigen oralen Diureticum aus der Gruppe der ungesättigtenα-,β-Ketonderivate der Phenoxyarylessigsäure (MK 595, Ethacrinsäure) mitgeteilt. Das Diureticum hat sich bei gesunden Versuchspersonen und Patienten mit kardialen und hepatogenen Ödemen als außerordentlich stark wirksam erwiesen. Selbst bei Patienten, deren Ödeme auf die bekannten Diuretica (inkl. Spirolactone) refraktär waren, konnte mit Ethacrinsäure eine Salidiurese erzielt werden. Die therapeutische Dosis beträgt 100–200 mg per os täglich oder jeden zweiten Tag. Die Nebenerscheinungen sind gering und selten. Zwischen der Natrium-, Kalium und Chlorid-Ausscheidung im Urin und Einzeldosen im Bereiche von 50 bis 350 mg besteht eine lineare Beziehung. Die Natrium-und vor allem die Chlorid-Ausscheidung werden sehr stark gesteigert. Die Kaliurese nimmt ebenfalls zu, aber in deutlich geringerem Maße. Das neue Phenoxyarylessigsäure-Derivat unterscheidet sich in seiner Wirkungscharakteristik von den bisher bekannten Diuretica vor allem durch vermehrte Ausscheidung von H-Ionen, was in einer erhöhten Titrationsacidität, im Abfall des Urin-pH und einer vermehrten Ammoniumausscheidung zum Ausdruck kommt. Im Blut entwickelt sich unter MK 595 regelmäßig eine Hypochlorämie, Hypokaliämie und eine leichte bis mäßige metabolische Alkalose. Eine gleichzeitige Kalium-substitution halten wir deshalb bei längerdauernder MK 595-Verabreichung als angezeigt. Ein besonderes Merkmal des neuen Diureticums ist sein sehr rascher Wirkungseintritt auch bei oraler Anwendung. Nach 200 mg MK 595 per os setzt die Diurese nach 30–60 min ein, erreicht nach 90 bis 120 min ihr Maximum und klingt nach 8–12 Std aus. In einigen Versuchen wurde nach 3 1/2–5 Std ein zweites Maximum der Diurese beobachtet. Auf Grund seiner Wirkungscharakteristik und Wirkungsstärke kommt das neue Diureticum besonders zur Ausschwemmung von solchen Ödemen in Frage, die auf die bisher bekannten Diuretica oder Diuretica-Kombinationen nicht angesprochen haben. Sein sehr rascher Wirkungseintritt läßt sich u. U. in Notfallsituationen (z. B. Lungenödem) auswerten.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Monatsschrift Kinderheilkunde 148 (2000), S. 494-495 
    ISSN: 1433-0474
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Biological cybernetics 2 (1964), S. 102-114 
    ISSN: 1432-0770
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Informatik , Physik
    Notizen: Summary This paper is concerned with the learning matrix for non-binary signals (LMn) as a classifying network. It can be shown that the properties of a LMn are determined by five parameters. One of these parameters corresponds to a criterion of similarity as the basis of the classification process. Two types of LMn, incorporating different criteria of similarity are investigated and compared as far as the accuracy and the invariance of classification are concerned. The second part of the paper deals with the technical realization of both types of the LMn. There the main problem is the storage of non-binary information in the connecting elements of the LMn. This difficulty can be met by the application of control techniques. Finally some results of investigations on transfluxors are reported which show that transfluxors are suitable connecting elements of a LMn.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1432-0509
    Schlagwort(e): Key words: Liver—MR imaging—Contrast media.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background: The purpose of this study was to compare the performance of in-phase and out-of-phase gradient recalled echo (GRE) pulse sequences on paramagnetic contrast-enhanced magnetic resonance (MR) imaging of malignant liver lesions. Methods: Fifty patients (27 women, 23 men; mean age = 50 ± 27 years) with known or suspected focal liver lesions, nine of whom had a fatty liver, were examined at 1.5 T before and 60 min after injection of gadobenate dimeglumine at a dose of 0.05 or 0.1 mmol/kg using two GRE techniques: echo time of 2.3 ms (out-of-phase) or 4.6 ms (in-phase). Liver signal-to-noise ratio (SNR) and lesion–liver contrast-to-noise ratio (CNR) were calculated. Results: In patients with a nonfatty liver, liver SNR increased from 26 ± 9 to 41 ± 17 on in-phase images and from 28 ± 8 to 45 ± 14 on out-of-phase images. In patients with a fatty liver, in-phase images provided significantly higher (p 〈 0.01) liver SNR than did out-of-phase images predose (34 ± 8 on in-phase vs. 21 ± 8 on out-of-phase) and postdose (44 ± 13 on in-phase vs. 33 ± 14 on out-of-phase). In patients with a nonfatty liver, lesion–liver CNR was similar on in-phase and out-of-phase images, predose and postdose. In patients with fatty liver, lesion–liver CNR was significantly (p 〈 0.01) lower on out-of-phase images on predose and postdose images. Conclusion: In-phase GRE imaging is recommended for imaging focal liver lesions on paramagnetic contrast-enhanced MR imaging in patients with fatty infiltration of the liver.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Archiv der Mathematik 12 (1961), S. 307-310 
    ISSN: 1420-8938
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Materialart: Digitale Medien
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