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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 5072-5078 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Room-temperature photoluminescence decay time measurements in heavily doped GaAs:C-layers designed as base layers for heterojunction bipolar transistors are reported. These measurements provide access to nonequilibrium minority carrier lifetimes that determine the current gains of those devices. By systematically studying transient luminescence spectra over a wide range of excitation densities between 1013 and 1018 cm−3, we demonstrate the importance of carrier trapping processes at low excitation densities. Optimized excitation conditions that achieve trap saturation but also avoid stimulated emission are found for densities of (1–3)×1017 cm−3/pulse. Detection is limited to a spectral window well above the energy gap (beyond 1.5 eV). Values for both Auger and radiative recombination coefficients are given. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Munksgaard International Publishers
    Scandinavian journal of medicine & science in sports 12 (2002), S. 0 
    ISSN: 1600-0838
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Sports Science
    Notes: (1) Age-associated loss of skeletal muscle mass and strength can partly be counteracted by resistance training, causing a net synthesis of muscular proteins. Protein synthesis is influenced synergistically by post-exercise amino acid supplementation, but the importance of the timing of protein intake remains unresolved. (2) The study investigated the importance of immediate (P0) or delayed (P2) intake of an oral protein supplement upon muscle hypertrophy and strength over a period of resistance training in elderly males. (3) Thirteen men (age 74 ± 1 years; body mass index (BMI), 25 ± 1 kg m− 2 (means ± SEM)) completed a 12-week resistance training program (three times per week) receiving oral protein in liquid form (10 g protein, 7 g carbohydrate, 3 g fat) immediately after (P0) or 2 h after (P2) each training session. Muscle hypertrophy was evaluated by magnetic resonance imaging (MRI) and from muscle biopsies and muscle strength was determined using dynamic and isokinetic strength measurements. Body composition was determined from dual-energy X-ray absorptiometry (DEXA) and food records were obtained over 4 days. The plasma insulin response to protein supplementation was also determined. (4) In response to training, the cross-sectional area of m. quadriceps femoris (54.6 ± 0.5–58.3 ± 0.5 cm2) and mean fiber area (4047 ± 320–5019 ± 615 μ m2) increased in the P0 group, whereas no significant increase was observed in P2. For P0 both dynamic and isokinetic strength increased, by 46 and 15%, respectively (P 〈 0.05), whereas P2 only improved in dynamic strength, by 36% (P 〈 0.05). No differences in glucose or insulin response were observed between protein intake at 0 and 2 h post-exercise. (5) We conclude that early intake of an oral protein supplement after resistance training is important for the development of hypertrophy in skeletal muscle of elderly men in response to resistance training.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-2013
    Keywords: Insulin ; Epinephrine ; Norepinephrine ; Glycogen ; Gluconeogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The significance of glucagon for post-exercise glucose homeostasis has been studied in rats fasted overnight. Immediately after exhaustive swimming either rabbit-antiglucagon serum or normal rabbit serum was injected by cardiac puncture. Cardiac blood and samples of liver and muscle tissue were collected before exercise and repeatedly during a 120 min recovery period after exercise. During the post-exercise period plasma glucagon concentrations decreased but remained above pre-exercise values in rats treated with normal serum, while rats treated with antiglucagon serum had excess antibody in plasma throughout. Nevertheless, all other parameters measured showed similar changes in the two groups. Thus after exercise the grossly diminished hepatic glycogen concentrations remained constant, while the decreased blood glucose concentrations were partially restored. Simultaneously concentrations in blood and serum of the main gluconeogenic substrates, lactate, pyruvate, alanine and glycerol declined markedly. During the post-exercise period NEFA concentrations in serum and plasma insulin concentrations remained increased and decreased, respectively, while plasma catecholamines did not differ from basal values. Muscle glycogen concentrations decreased slightly. These findings suggest that in the recovery period after exhaustive exercise the increased glucagon concentrations in plasma do not influence gluconeogenesis.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 53 (1975), S. 237-239 
    ISSN: 1432-1440
    Keywords: FSH ; LH ; testosterone ; gonadotropin regulation ; FSH ; LH ; Testosteron ; Gonadotropinregulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Intramuskuläre Injektion von 250 mg Testosteronönanthat je Woche über 21 Wochen fürhrte zu einem raschen und anhaltenden Absinken der Serum-FSH- und -LH-Spiegel bei sieben männlichen Normalpersonen, während die Serum-Testosteronspiegel um etwa einen Faktor 2 anstiegen. Diese und frühere Ergebnisse verweisen auf eine zweifache Feedback-Hemmung der FSH-Sekretion beim Mann durch Gonadensteroide sowie einen bis heute nicht näher charakterisierten tubulären Hodenfaktor.
    Notes: Summary Intramuscular administration of 250 mg testosterone oenanthate per week over a period of 21 weeks treatment rapidly and sustainedly suppressed serum LH as well as FSH levels in seven normal males, while serum testosterone rose by a factor of approximately two. These together with other data provide increasing evidence for a feedback control of FSH secretion by gonadal steroids in the male in addition to the already described but as yet undefined tubular testicular factor.
    Type of Medium: Electronic Resource
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  • 5
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    Berlin : Periodicals Archive Online (PAO)
    Orientalistische Literaturzeitung. 70:2 (1975:März/Apr.) 186 
    ISSN: 0030-5383
    Topics: Linguistics and Literary Studies , Ethnic Sciences , History
    Notes: Besprechungen
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  • 6
    ISSN: 1432-1041
    Keywords: Rifampicin ; induction of drug metabolism ; cirrhosis ; cholestasis ; hexobarbital kinetics ; tolbutamide kinetics ; plasma concentrations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Eleven patients with hepatic cirrhosis or cholestasis were treated with rifampicin for 7 to 132 days. Ten patients received hexobarbital (7.32 mg/kg) and five received tolbutamide (20 mg/kg) by i.v. infusion prior to and after rifampicin treatment; plasma concentrations of the two test compounds were determined during and after infusion. The average elimination half-life of hexobarbital had decreased from 624 to 262 min and that of tolbutamide from 292 to 160 min following rifampicin treatment. It was calculated that the metabolic clearance of hexobarbital had increased more than two-fold and that of tolbutamide almost two-fold. The results suggest that rifampicin is able to stimulate hepatic drug metabolism in patients with liver disease. It was apparent in general that the induction did not lead to improvement of hepatocellular function during disease as judged by laboratory findings.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 9 (1975), S. 219-227 
    ISSN: 1432-1041
    Keywords: Rifampicin ; induction of drug metabolism ; hexobarbital kinetics ; tolbutamide kinetics ; plasma concentrations ; man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Five healthy volunteers took 1.2 g rifampicin daily for 8 days, and before and afterwards each received hexobarbital (7.32 mg/kg) and tolbutamide (20 mg/kg) by i.v. infusion on two consecutive days. The plasma concentrations of the two drugs were determined during and after infusion. The average elimination half-life of hexobarbital had decreased from 325 to 122 min and of tolbutamide from 418 to 183 min following rifampicin treatment. It was calculated that the metabolic clearance of hexobarbital had increased about three-fold and that of tolbutamide more than two-fold. Significant changes in the distribution kinetics of the two drugs were not observed. The results suggest that rifampicin is capable of inducing drug metabolism in man, which leads to an increased rate of elimination of drugs that undergo biotransformation in the liver.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 35 (1976), S. 141-147 
    ISSN: 1432-0738
    Keywords: Age ; Blood ; Hexachlorobenzene (HCB) ; Children ; Kinetics ; Alter ; Blut ; Hexachlorbenzol (HCB) ; Kinder ; Kinetik
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei 98 männlichen und 96 weiblichen oberbayerischen Kindern im Alter von 1–18 Jahren wurde Vollblut im Frühjahr 1975 gaschromato-graphisch auf Hexachlorbenzol (HCB) untersucht. Alle Blutproben enthielten HCB in einer Konzentration zwischen 2,6 und 77,9 ppb. Die HCB-Konzentration war positiv und hyperbolisch mit dem Lebensalter korreliert und tendierte gegen einen Grenzwert, der bei den Knaben ca. 22 und bei den Mädchen ca. 17 ppb betrug. Die Anstiegsgeschwindigkeit der HCB-Konzentration war dem Quadrat des Alters umgekehrt proportional. Aus dem Konzentrationsverlauf ergab sich, daß die wesentliche HCB-Belastung der Kinder offenbar 9–10 Monate nach der Geburt einsetzte (Umweltkontakt?). Ohne Einfluß auf die HCB-Konzentration waren infektiöse Erkrankungen bei einem Teil der Kinder. Auch regionale Unterschiede konnten nicht objektiviert werden, obwohl der Eindruck entstand, daß die HCB-Konzentration im Blut der Landkinder höher als im Blut der Stadtkinder war.
    Notes: Abstract In the spring of 1975, samples of whole blood of 98 male and 96 female children from Upper Bavaria, of 1–18 years of age, were examined for hexachlorbenzene (HCB) by gas chromatographic methods. All blood samples contained HCB ranging in concentration from 2,6 to 77,9 ppb. The HCB concentration shows a positive, hyperbolic correlation with age, tending toward a limiting value of 22 ppb for boys and 17 ppb for girls. The rate of increase in HCB concentration is inversely proportional to the square of the age. The concentration profile suggests that a substantial amount of HCB apparently starts to show up 9–10 months after birth (environmental effects?). No change in HCB concentration could be found in those children with infectious diseases. Furthermore, regional differences could not be detected, although the impression was that the HCB content was higher in children from rural areas than in children from urban areas.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' journal of analytical chemistry 366 (2000), S. 444-448 
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The development of a new methodology for the construction of very efficient flow cells for mercury detection by potentiometric stripping analysis, employing the thin gold layer of recordable CDs as working ¶electrode is reported. This new source of electrodes (CDtrodes) show very attractive performance, similar to that obtained with commercial gold electrodes, with superior versatility. The low cost of this new source of “gold electrodes” allows a frequent replacement of the electrode, avoiding cumbersome clean-up treatments. Various experimental parameters have been optimized to yield low detection limits (0.25 ng/mL of mercury for 5 min deposition at 0.3 V) and good precision (standard deviation of 1.9% was obtained for 15 repetitive measurements using 10 ng/mL of mercury). Standard curves were found to be linear over the range of 0.5–100 μg L–1 of mercury. The flow cells developed were used for the quantification of mercury in oceanic and tap water.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric radiology 30 (2000), S. 715-715 
    ISSN: 1432-1998
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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