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41.
The role of cytokines in Henoch Schonlein purpura   总被引:1,自引:0,他引:1  
Serum levels of tumor necrosis factor (TNF) and interleukin(IL-1) were studied in 20 HSP patients, in the acute phase and after remission, by ELISA technique. Skin biopsies obtained during the acute phase both from a lesion and from unaffected skin, as well as during remission, were immunostained for TNF, IL-1, and IL-6. The mean age of the patients was 9.8 (5-13). Mean serum TNF levels during the acute phase and remission were 14.0 +/- 8.9 pg/ml, and 6.8 +/- 2.4 pg/ml, respectively (p < 0.05). Serum TNF levels in patients with renal involvement (18.8 +/- 10.2 pg/ml) were significantly higher than in those without (10.8 +/- 6.5 pg/ml) (p < 0.05). Serum levels of IL-1 in the acute phase and remission were undetectable. All specimens showed leukocytoclastic vasculitis. Immunohistochemical studies revealed TNF, and a less intense IL-1 and IL-6 staining in the nucleated epidermal layer, with a granular, intracellular pattern. Staining was significantly increased in the affected skin during the acute phase. These results suggest that TNF, IL-1, and IL-6 may play a role as a mediator of inflammation in HSP.  相似文献   
42.
Much of the research related to residential electric and magnetic field exposure focuses on cancer risk for children. But until now only little knowledge about coupling of external transient electric and magnetic fields with the child's body at low frequency transients existed. In this study, current densities, in the frequency range from 50 Hz up to 100 kHz, induced by external electric and magnetic fields to child and adult human body, were investigated, as in residential areas, electric and magnetic fields become denser in this frequency band. For the calculations of induced fields and current density, the ellipsoidal body models are used. Current density induced by the external magnetic field (1 microT) and external electric field (1 V/m) is estimated. The results of this study show that the transient electric and magnetic fields would induce higher current density in the child body than power frequency fields with similar field strength.  相似文献   
43.
This work proposes the survey of magnetic field measurements taken in 154/31.5 kV substations in the city of Antalya for occupational exposure assessment. For measurements, three substations have been taken into account, where four occupants are present for each 8 h of shift, which means 12 occupants are present during the day. Operator desks at three different substations read a lowest magnetic field of 0.3 microT at minimum loaded season and reached up to 1 microT at maximum loaded season, which means operators exposed to a magnetic field of > or = 0.3 microT 8 h d(-1). In switch gear regions, maximum magnetic field reading is 23 microT at minimum loaded season and reached up to 70 microT. Outdoor magnetic field measurement at circuit breaker region goes up to 62 microT with respect to operator heights.  相似文献   
44.
The composition of olive oils may vary depending on environmental and technological factors. Fatty acid profiles and Fourier‐transform infrared (FT‐IR) spectroscopy data in combination with chemometric methods were used to classify extra‐virgin olive oils according to geographical origin and harvest year. Oils were obtained from 30 different areas of northern and southern parts of the Aegean Region of Turkey for two consecutive harvest years. Fatty acid composition data analyzed with principal component analysis was more successful in distinguishing northern olive oil samples from southern samples compared to spectral data. Both methods have the ability to differentiate olive oil samples with respect to harvest year. Partial least squares (PLS) analysis was also applied to detect a correlation between fatty acid profile and spectral data. Correlation coefficients (R2) of a calibration set for stearic, oleic, linoleic, arachidic and linolenic acids were determined as 0.83, 0.97, 0.97, 0.83 and 0.69, respectively. Fatty acid profiles were very effective in classification of oils with respect to geographic origin and harvest year. On the other hand, FT‐IR spectra in combination with PLS could be a useful and rapid tool for the determination of some of the fatty acids of olive oils.  相似文献   
45.
Polypyrrole (PPy) was doped with the azocalix[4]arene [(5,11,17,23‐tetrakis[(p‐carboxyphenyl)azo]25,26,27,28‐tetrahydroxycalix[4]arene)] host species. PPy/azocalix[4]arene salts were characterized by FTIR, TGA, SEM, X‐ray diffraction, and conductivity measurements. The properties of PPy were investigated in the presence of azocalix[4]arene host species. The conductivity of PPy increased in the presence of azocalix[4]arene. TGA results indicated that the PPy/azocalix[4]arene salts have higher thermal stability than PPy. It was observed from SEM analysis that the particle diameter of PPy decreased with increasing content of azocalix[4]arene. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   
46.
47.
The aim of this study is to improve features of 60/70 penetration grade modified bitumen used on highways. A new asphalt compound has been formed by an additive to decrease sensitivity to temperature and to increase resistance of bitumen. As additives, synthetic reactive ethylene terpolymer (SRETP) and ethylene terpolymer (ETP), which were recommended by DuPont, have been added in bitumen and made some trials. Infrared (IR) graphics and optical pictures of the modified bitumen have been examined and after analysis of the tests, a clear increasing at softening point but decreasing in penetration and ductility values have been observed as a result.  相似文献   
48.
Processing factors affecting the osmotic dehydration of diced green peppers   总被引:2,自引:0,他引:2  
A 25–2 fractional factorial design was used to investigate the effect of salt (2–10%), sorbitol (0–10%) concentration, agitation (0–80 r.p.m.), tissue to solution ratio (1:3 to 1:6) and temperature (20–50 °C) on weight loss, solids gain, salt and sorbitol uptake, water activity, tissue brix and solution brix, during osmotic dehydration (OD) of diced green peppers. Results showed that salt and sorbitol concentration were the most significant factors. In the first half hour of the osmotic process, salt and sorbitol significantly increased weight loss, solids gain and tissue brix, and decreased water activity. Temperature was also a significant factor. It increased weight loss during the first 2 h of the process, and decreased water activity after 20 h of osmosis. Agitation and tissue to solution ratio were less important.  相似文献   
49.
The aim of this study is to investigate the effects of preload moment, moisture and interference-fit on bearing strength and failure mode in pin-jointed and bolted carbon–epoxy plates which were subjected to a traction force. Two different geometrical parameters, end distance to pin diameter ratio (E/D) and width to pin diameter ratio (W/D), were considered experimentally. E/D and W/D ratios were selected ranging from 1 to 4 and from 2 to 4, respectively. The test results showed that the ultimate failure loads were directly affected by the geometrical parameters, preload moments and interference-fit. Furthermore, for the specimens in wet condition, failure loads increased with preload moments while failure loads stayed almost the same in non-preloaded specimens. Finite element models of the specimens were also developed by using ANSYS software. Contact and stress analyses of the models were carried out for both free and interference-fit. Tsai-Wu criterion was used to determine bearing strength corresponding to first failure load. It was concluded that the numerical results are in good agreement with experimental results.  相似文献   
50.
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