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  • 1
    Digitale Medien
    Digitale Medien
    Rapid frequency step-switching of a submillimeter wave gyrotron by modulation of the electron beam (1994)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 1 (1994), S. 1774-1776 
    Details
    ISSN: 1089-7674
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: An experimental study of the rapid step-switching of the frequency of a submillimeter wave gyrotron is described. Modulation of the energy of the electron beam in turn modulates the electron mass and hence the cyclotron resonance frequency fc or its second harmonic 2fc, while the magnetic field B0 remains the same. This opens up the possibility of switching from one cavity mode to another. The first experimental results for frequency switching between two fundamental modes and between a fundamental and a second harmonic mode are demonstrated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.870683
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  • 2
    Digitale Medien
    Digitale Medien
    High-frequency, amplitude modulation of a submillimeter wave, medium power gyrotron (1994)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 1 (1994), S. 461-463 
    Details
    ISSN: 1089-7674
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Experimental results of the amplitude modulation of the output of a submillimeter wave gyrotron are presented. The 100% modulation of the output at frequencies up to several hundred kilohertz has been achieved with anode modulation levels of only a few percent. A good account of the experimental results is given by including a small modulation of the anode voltage in an energy transfer formula and then calculating the power output.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.870846
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  • 3
    Digitale Medien
    Digitale Medien
    Development of a high-frequency, second-harmonic gyrotron tunable up to 636 GHz (1993)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 5 (1993), S. 1377-1379 
    Details
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: In this Letter, a high-frequency, second-harmonic gyrotron using a 12 T superconducting magnet is described. It has achieved a maximum frequency of 636 GHz (corresponding to a wavelength of 472 μm). Operating at both the fundamental and the second harmonic of the electron cyclotron frequency enables the gyrotron to act as a high power (several 100 W), step tunable, millimeter to submillimeter wave source in the wide frequency range from 150 to 630 GHz.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.860928
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  • 4
    Digitale Medien
    Digitale Medien
    Effect of an Herbal Preparation, Saiboku-to (TJ-96), on Antigen-Induced Airway Hyperresponsiveness and Eosinophil Infiltration in Actively Sensitized Guinea Pigs (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 685 (1993), S. 0 
    Details
    ISSN: 1749-6632
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Allgemeine Naturwissenschaft
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1749-6632.1993.tb35919.x
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  • 5
    Digitale Medien
    Digitale Medien
    Differential Neuropeptide Responses to Starvation with Ageing (2001)
    Oxford, UK : Blackwell Science, Ltd
    Journal of neuroendocrinology 13 (2001), S. 0 
    Details
    ISSN: 1365-2826
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: During starvation, counterregulatory responses to loss of food (i.e. responses that lead to an increase in appetite) occur in the central nervous system (CNS). This study was designed to examine whether middle-aged rats show greater or smaller behavioural, peripheral and central hormonal responses during starvation compared to young rats. In experiment 1, refeeding following 4 days of starvation was measured in both middle-aged (72-week-old) and young (9-week-old) rats. The level of refeeding was similar to each prestarved level until 3 days after the end of starvation in both groups. From the 4th day, the level of refeeding in young rats increased and reached beyond the prestarved level, whereas refeeding in middle-aged rats remained similar to the prestarved level. Thus, overall refeeding throughout 7 days was greater in young rats than in middle-aged rats. In experiment 2, middle-aged and young rats were starved for 4 days and were killed in the morning. Middle-aged rats showed a smaller plasma corticosterone response than that of young rats. The magnitude of decreases in plasma glucose, insulin and leptin was similar in both groups. In the arcuate nucleus, the starvation-induced increase in neuropeptide Y (NPY) mRNA and the decrease in proopiomelanocortin (POMC) mRNA were smaller in middle-aged rats than in young rats. In contrast, the starvation-induced decrease in corticotrophin-releasing hormone (CRH) mRNA in the hypothalamic paraventricular nucleus was greater in middle-aged rats than young rats. The magnitude of decrease in type-2 CRH receptor mRNA in the ventromedial hypothalamus was similar in both groups. The results indicate that (a) ageing impaired refeeding response (b), middle-aged rats showed the same directional neuropeptide mRNA responses as seen in young rats during starvation and (c) the magnitude of these counterregulatory responses in the CNS in middle-aged versus young rats was not uniform, but rather was site-specific or neuropeptide-specific. This study suggests the importance of NPY and POMC responsiveness in the arcuate nucleus in the age-related differences resulting from starvation-induced refeeding.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2826.2001.00730.x
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  • 6
    Digitale Medien
    Digitale Medien
    Altered Expression of p53 mRNA in the Brain and Pituitary During Repeated Immobilization Stress: Negative Correlation with Glucocorticoid Receptor mRNA Levels (2004)
    Oxford, UK : Blackwell Science Ltd
    Journal of neuroendocrinology 16 (2004), S. 0 
    Details
    ISSN: 1365-2826
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: In our previous study, apparent reduction of glucocorticoid receptor (GR) mRNA was seen in the hippocampus and the hypothalamic paraventricular nucleus (PVN) during repeated immobilization (IMO) stress, but not following starvation. Our laboratory has also shown that the sp1 activates, whereas tumour suppressor p53 represses the promoter activity of GR gene. In an attempt to reveal the possibility that transcription factors such as sp1 and/or p53 are involved in the regulation of GR mRNA expression in the hippocampus and in the PVN in vivo, we examined the expression of GR mRNA, p53 mRNA, and sp1 mRNA in the hippocampus and in the PVN during repeated IMO and following starvation. In addition, the expression of these mRNAs was examined in the anterior pituitary, another GR-rich area. GR mRNA in all subfields of the hippocampus was robustly decreased, while GR mRNA in the anterior pituitary was increased, 24 h following 4 × IMO (2 h daily, for 4 consecutive days) and immediately after 5 × IMO. GR mRNA in the PVN was significantly decreased immediately after 5 × IMO, but not at 24 h after 4 × IMO. Conversely, p53 mRNA in the PVN and hippocampus was increased, whereas p53 mRNA in the anterior pituitary was decreased, 24 h following 4 × IMO and immediately after 5 × IMO. Sp1 mRNA was unchanged in all areas examined following repeated IMO. Following 4 days of starvation, neither GR mRNA, p53 mRNA nor sp1 mRNA showed any changes in the PVN and the hippocampus, except there was a minor decrease in GR mRNA in CA1-2. In the anterior pituitary, 4 days of starvation induced a minor, but significant increase in GR mRNA, whereas it decreased p53 mRNA. Overall, regression analyses revealed a negative correlation between GR mRNA levels and p53 mRNA levels in CA1-2 and dentate gyrus of the hippocampus and in the anterior pituitary. GR mRNA in the PVN also showed a tendency towards the negative correlation with p53 mRNA levels. The results raise the possibility that p53 negatively regulates GR mRNA expression in the PVN, the hippocampus and the anterior pituitary during repeated immobilization stress.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2826.2004.01131.x
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  • 7
    Digitale Medien
    Digitale Medien
    The N-terminal prepeptide is required for the production of spore cortex-lytic enzyme from its inactive precursor during germination of Clostridium perfringens S40 spores (2000)
    Oxford, UK : Blackwell Science Ltd
    Molecular microbiology 37 (2000), S. 0 
    Details
    ISSN: 1365-2958
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie , Medizin
    Notizen: A spore cortex-lytic enzyme of Clostridium perfringens S40 is synthesized during sporulation as a precursor consisting of four domains. After cleavage of an N-terminal preregion and a C-terminal proregion, inactive proenzyme (termed C35) is converted to active enzyme by processing of an N-terminal prosequence with germination-specific protease (GSP) during germination. The present results demonstrated that the cleaved N-terminal prepeptide remained associated with C35. After the isolated complex was denatured and dissociated in 6 M urea solution, removal of urea regenerated a prepeptide–C35 complex which produces active enzyme when incubated with GSP. However, isolated C35 alone could not be activated by GSP. The prepeptide–C35 complex was more heat stable than active enzyme. Thus, non-covalent attachment of the prepeptide to C35 is required to assist correct folding of C35 and to stabilize its conformation, suggesting that the prepeptide functions as an intramolecular chaperone. Recombinant proteins, which have prepeptide covalently bonded to C35, were processed by GSP as well as the in vivo prepeptide–C35 complex, and the full length of the N-terminal presequence was needed to fulfil its role. Although the C-terminal prosequence is present as an independent domain which is not involved in the activation process of the enzyme, it appears that the N-terminal prosequence contributes to the regulation of enzyme activity as an inhibitor of the enzyme.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2958.2000.02047.x
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  • 8
    Digitale Medien
    Digitale Medien
    Identification of a novel gene, dep, associated with depolymerization of the capsular polymer in Bacillus anthracis (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Molecular microbiology 9 (1993), S. 0 
    Details
    ISSN: 1365-2958
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie , Medizin
    Notizen: Bacillus anthracis produces a gamma-linked poly-D-glutamic acid capsule that is essential for virulence. A 6.2 kb fragment of B. anthracis DNA (cap), when present in Escherichia coli, produces a capsular polymer that is immunologically identical to that produced by B. anthracis. By immunodiffusion analysis of E. coli strains carrying varying portions of the cap region, we identified a novel gene (dep) responsible for degradation of the capsular polymer of B. anthracis. The simultaneous presence of the cap region and the dep gene caused production of low-molecular-weight, degraded capsular polymer both in E. coli and in B. anthracis, whereas the cap region atone caused production of a high-molecular-weight capsule. The dep gene mapped immediately downstream of the cap region within a 1.8 kb fragment and was transcribed in the same direction. This fragment was sequenced and a 1401 bp open reading frame (ORF) was found that is predicted to encode a peptide with molecular weight of 51460. By in vitro transcription-translation analysis, this ORF was shown to be the dep gene product. The deduced amino acid sequence of the dep product has sequence similarity to E. coli and mammalian γ-glutamyltranspeptidase (GGT). However, the Dep protein did not have GGT activity. The Dep protein appears to be an enzyme that catalyses the hydrolysis of the poly-D-glutamic acid capsule. Although the biological functions of the dep gene are unknown, it is possible that low-molecular-weight, diffusible polyglutamates produced through the action of the dep gene may act to inhibit host defence mechanisms.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2958.1993.tb01710.x
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  • 9
    Digitale Medien
    Digitale Medien
    Survey of recognition and utilization of guidelines for the diagnosis and management of bronchial asthma in Japan (2000)
    Copenhagen : Munksgaard International Publishers
    Allergy 55 (2000), S. 0 
    Details
    ISSN: 1398-9995
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background: In Japan in 1993, the Japanese Society of Allergology (JSA) developed guidelines for diagnosis and management of asthma (JGL), which were based on the concept that asthma is a chronic inflammatory disorder of the airway. Methods: This survey study was intended to investigate the recognition and utilization of JGL among physicians who had treated asthma. The survey comprised two methods: a quantitative mail survey and a qualitative door-to-door survey conducted by trained interviewers. Results: In the mail survey, a total of 1028 physicians responded; 552 members of the JSA and 476 nonmembers. Ninety-four percent of JSA members were aware of adult asthma management guidelines, while 53 nonmembers were aware of them. Although approximately half of the physicians, both member and nonmember, found differences between the asthma management policies in JGL and their previous policies, most of them utilized JGL, once they read it. In the qualitative door-to-door survey, 80–90% of physicians evaluated JGL as good after they read it. Conclusions: JGL was recognized and utilized by most JSA members, but only half of nonmember physicians were aware of JGL, although they utilized JGL after they read it. Further action to implement JGL among nonspecialist physicians is needed to improve management of asthma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1034/j.1398-9995.2000.00090.x
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  • 10
    Digitale Medien
    Digitale Medien
    Clinical significance of measuring levels of sputum and serum ECP and serum IL-5 in bronchial asthma (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 48 (1993), S. 0 
    Details
    ISSN: 1398-9995
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1398-9995.1993.tb04709.x
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