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21.
DuD Recht     

DuD Recht

DuD Recht  相似文献   
22.
To investigate the potential anti-inflammatory effects of sesame oil, which is present in the injectable gold preparation Auromyose, the synthesis of tumour necrosis factor alpha (TNF-alpha), prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) by in vitro stimulated blood cells was measured before, during and after 12 weeks of dietary supplementation with 18 g of sesame oil daily in 11 healthy male volunteers. Neither TNF-alpha, PGE2 nor LTB4 production levels showed statistically significant changes during the 12 weeks of dietary supplementation with sesame oil. These results do not suggest an anti-inflammatory effect of sesame oil as present in injectable gold preparations which are used in the treatment of rheumatoid arthritis.  相似文献   
23.
Epidemiological studies have shown that steroidal as well as non-steroidal anti-inflammatory drugs lower the risk of developing Alzheimer's Disease (AD). A suppressive effect of these anti-inflammatory drugs on local inflammatory events in AD brains has been suggested, however the mechanisms responsible are still unknown. In this study we investigated at cellular level the influence of two anti-inflammatory drugs-dexamethasone and indomethacin--and an experimental specific cyclooxygenase-2 inhibitor, BF389, on the production of the pro-inflammatory cytokine IL-6 and the inflammatory mediator PGE2 by human astrocytes. Two human post-mortem astrocyte cultures (A157 and A295) and astroglioma cell lines (U251 and U373 MG) were found to secrete considerable amounts of IL-6 upon stimulation with IL-1beta. The glucocorticoid dexamethasone inhibited the IL-1beta-activated release of IL-6 from the postmortem astrocyte cultures A157 and A295 and from the astroglioma cell lines. The non-specific cyclooxygenase inhibitor indomethacin and BF389 only suppressed the IL-6 release by post-mortem astrocyte culture A157. This post-mortem astrocyte culture was found to produce large amounts of PGE2 upon stimulation with IL-1beta, whereas in the supernatants of the postmortem astrocyte culture A295 and the astroglioma cell lines, low PGE2 concentrations were detected. Addition of exogenous PGE2 prevented the inhibitory effect of indomethacin and BF389 on the IL-1beta-activated IL-6 release from A157 astrocytes and largely potentiated the IL-1-induced release of IL-6 from all astrocytes/astroglioma cells tested. Dexamethasone also inhibited the PGE2 release from the astrocytes and astroglioma cells, however the inhibitory effect of dexamethasone on the IL-1beta-activated IL-6 release could not be prevented by the addition of PGE2. The observed reduction of IL-6 and/or PGE2 from astrocytes may be involved in the mechanism underlying the beneficial effects of these drugs in AD.  相似文献   
24.
This study examined whether detrimental childhood relationships with parents were related to partner relationship quality and emotional adjustment in adulthood. The authors tested a theoretical model in which (a) low-quality parent-child relationships were related to conflict and low-quality communication with parents in adolescence, (b) parent-adolescent conflict and low-quality communication were linked to low-quality partner relationships in young adulthood, and (c) low-quality partner relationships in young adulthood were predictive of low-quality partner relationships as well as depression, anxiety, and dissatisfaction with life at midlife. Multi-informant data were used from 212 Swedish individuals who were followed from birth into adulthood. Results demonstrated that, as hypothesized, negative parent-child bonds were indirectly related to low-quality partner relationships and dissatisfaction with life in adulthood (but not anxiety and depression) through conflictual parent-adolescent communication and low-quality partner relationships in young adulthood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
25.
The multilevel modulation techniques of 64-quadrature amplitude modulation (QAM) and 64-differential amplitude and phase-shift keying (DAPSK) have been proposed in combination with the orthogonal frequency-division multiplexing (OFDM) scheme for digital terrestrial video broadcasting (DTVB). With this system a data rate of 34 Mb/s can be transmitted over an 8-MHz radio channel. A comparison of these modulation methods in the uncoded case has been presented by Engels and Rohling (see European Trans. Telecommun., vol.6, p.633-40, 1995). The channel coding scheme proposed for DTVB by Schafer (see Proc. Int. Broadcasting Convention, Amsterdam, The Netherlands, p.79-84, 1995) consists of an inner convolutional code concatenated with an outer Reed-Solomon (RS) code. In this paper the performance of the convolutional codes is analyzed for the two modulation techniques. This analysis includes soft decision Viterbi (1971) decoding of the convolutional code. For soft decision decoding of DAPSK modulated signals a new metric is developed  相似文献   
26.
A low-complexity ML channel estimator for OFDM   总被引:2,自引:0,他引:2  
Orthogonal frequency-division multiplexing with cyclic prefix enables low-cost frequency-domain mitigation of multipath distortion. However, to determine the equalizer coefficients, knowledge of the channel frequency response is required. While a straightforward approach is to measure the response to a known pilot symbol sequence, existing literature reports a significant performance gain when exploiting the frequency correlation properties of the channel. Expressing this correlation by the finite delay spread, we build a deterministic model parametrized by the channel impulse response and, based on this model, derive the maximum-likelihood channel estimator. In addition to being optimal (up to the modeling error), this estimator receives an elegant time-frequency interpretation. As a result, it has a significantly lower complexity than previously published methods.  相似文献   
27.
The average bit-error rate of transmit antenna selection combined with receive maximum-ratio combining is computed as a function of the transmit antenna update rate when using binary phase-shift keying in flat Rayleigh fading channels. This scheme achieves an order of diversity equal to the product of the number of transmit and receive antennas. Therefore, it can gain significant diversity benefits over traditional receive diversity schemes by distributing the antennas over the transmit and receive side  相似文献   
28.
Versuche und Rechnungen zur Ankoppelung von Ultraschall an heiße, metallische Prüfstücke durch Wasser. Ermittlung der höchsten, eine Ultraschallübertragung durch Wasser noch zulassenden Oberflächentemperatur. Ankoppelungszeiten in Abhängigkeit von Wasserdurchfluß, Wassertemperatur und Oberflächentemperatur. Beschreibung eines wirksamen Kühlverfahrens zur schnellen Ankoppelung an bewegte Prüfstücke bei hohen Temperaturen. Anwendung auf Stranggußknüppel mit einer Oberflächentemperatur von 1250 °C bei einer Prüfgeschwindigkeit von 3 m/min. Rißempfindlichkcit verschiedener Stähle gegenüber rascher Abkühlung.  相似文献   
29.
Recent research has shown that daily changes in self-efficacy predict lapses and relapse into smoking after quitting among adolescent daily smokers, but it is not known if and how momentary self-efficacy is associated with affect-motivational states and external contexts. In the present study, 134 adolescent daily smokers were monitored daily during 1 week prior to and 3 weeks after they began their quit attempt. Participants completed questions on smoking, self-efficacy, affect-motivational states (craving and negative affect), and external contexts (seeing others smoke, experiencing a stressful event, and alcohol and coffee consumption) three times a day. Affect-motivational states as well as all external contexts (except for coffee consumption) were associated with lower self-efficacy when participants were still abstinent, but also after they had lapsed. Associations between the situational contexts and self-efficacy did not largely depend on individual characteristics such as baseline self-efficacy and age. Among girls, however, the negative associations between self-efficacy and negative affect and drinking alcohol were found to be stronger. These results show that adolescents' self-efficacy during a quit attempt may be responsive to affect-motivational states and external contexts, both before and after lapsing. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
30.
To increase understanding of the etiology and epidemiology of nicotine dependence among adolescent smokers, the present study examined the occurrence and development of distinct nicotine dependence symptom profiles in a sample of adolescent smokers. A total of 25 secondary schools throughout the Netherlands participated in a 1-year longitudinal study. Multiple dimensions of nicotine dependence were assessed, at two time points, among 641 adolescents (aged 14–17 years) who were classified as smokers. Results showed 4 distinct, yet stable, nicotine dependence subtypes that could be characterized by quantitative as well as qualitative differences. The symptom profiles were similar for males and females but differentially associated with previously identified correlates of nicotine dependence, namely parental smoking, peer smoking, and depressive mood. Finally, differential links of the 4 subtypes were found with regard to smoking uptake and cessation. The finding of qualitative different subgroups of adolescent smokers may have important implications for intervention efforts regarding nicotine dependence and smoking cessation. Such efforts may need to be tailored to the specific subgroups’ needs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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