排序方式: 共有16条查询结果,搜索用时 46 毫秒
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Juliana S Luz Celso RR Ramos Márcia CT Santos Patricia P Coltri Fernando L Palhano Debora Foguel Nilson IT Zanchin Carla C Oliveira 《BMC biochemistry》2010,11(1):22
Background
The archaeal exosome is formed by a hexameric RNase PH ring and three RNA binding subunits and has been shown to bind and degrade RNA in vitro. Despite extensive studies on the eukaryotic exosome and on the proteins interacting with this complex, little information is yet available on the identification and function of archaeal exosome regulatory factors. 相似文献3.
Xu Y Weynants RR Jachmich S Van Schoor M Vergote M Peleman P Jakubowski MW Mitri M Reiser D Unterberg B Finken KH;TEXTOR Team 《Physical review letters》2006,97(16):165003
Systematic measurements on the edge turbulence and turbulent transport have been made by Langmuir probe arrays on TEXTOR under various static Dynamic Ergodic Divertor (DED) configurations. Common features are observed. With the DED, in the ergodic zone the local turbulent flux reverses sign from radially outwards to inwards. The turbulence properties are profoundly modified by energy redistribution in frequency spectra and suppression of large scale eddies. The fluctuation poloidal phase velocity changes direction from electron to ion diamagnetic drift, consistent with the observed reversal of the Er x B flow. In the laminar region, the turbulence is found to react to an observed reduced flow shear. 相似文献
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Renata Monteiro-Maia Maria B Ortigão-de-Sampaio Rosa T Pinho Luiz RR Castello-Branco 《Journal of immune based therapies and vaccines》2006,4(1):1-6
We hypothesize that the energy strategy of a cell is a key factor for determining how, or if, the immune system interacts
with that cell. Cells have a limited number of metabolic states, in part, depending on the type of fuels the cell consumes.
Cellular fuels include glucose (carbohydrates), lipids (fats), and proteins. We propose that the cell's ability to switch
to, and efficiently use, fat for fuel confers immune privilege. Additionally, because uncoupling proteins are involved in
the fat burning process and reportedly in protection from free radicals, we hypothesize that uncoupling proteins play an important
role in immune privilege. Thus, changes in metabolism (caused by oxidative stresses, fuel availability, age, hormones, radiation,
or drugs) will dictate and initiate changes in immune recognition and in the nature of the immune response. This has profound
implications for controlling the symptoms of autoimmune diseases, for preventing graft rejection, and for targeting tumor
cells for destruction. 相似文献
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VG Adlakha RR Vemuganti 《International Journal of Mathematical Education in Science & Technology》2013,44(5):708-713
In many practical situations scaling the data is necessary to solve linear programs. This note explores the relationships in translating the sensitivity analysis between the original and the scaled problems. 相似文献
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In TEXTOR the long-range time dependence of edge plasma fluctuations has been investigated. The results indicate that the tail of the autocorrelation function decays as a power law for time lags longer than the local decorrelation time. The frequency spectra of the fluctuations show similar features to those obtained in "sandpile" models. Using rescaled range (R/S) analysis techniques the self-similarity parameters have been estimated for the potential fluctuation data detected by Langmuir probes. The results show that the Hurst exponents are well above 0.5 over the self-similarity range at all the measured radial locations. All these facts reveal the self-similar character of the electrostatic fluctuations at the plasma edge of TEXTOR, consistent with plasma transport as characterized by self-organized criticality (SOC). Furthermore, we have analyzed in this respect discharges in which an edge transport barrier was created by means of edge biasing, hitherto limited to floating potential measurements in the scrape off layer outside the barrier region. The results show a decrease of fluctuating amplitudes, a reduction of decorrelation time of local turbulence and, surprisingly, a concomitant increase of the Hurst exponent. This result implies that the mechanisms governing the decorrelation of local turbulence may differ from those governing the decorrelation of SOC transport events. 相似文献
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Renata Monteiro-Maia Maria B Ortig?o-de-Sampaio Rosa T Pinho Luiz RR Castello-Branco 《Journal of immune based therapies and vaccines》2006,4(1):4
Background
Oral administration of BCG was the route initially used by Calmette and Guérin, but was replaced by intradermal administration in virtually all countries after the Lubeck accident. However, Brazil continued to administer oral BCG Moreau RDJ, which was maintained until the mid-1970s when it was substituted by the intradermal route. Although BCG vaccination has been used in humans since 1921, little is known of the induced immune response. The aim of this study was to analyse immunological responses after oral vaccination with M. bovis BCG Moreau RDJ. 相似文献9.
We have investigated the superconducting properties of the Bi1.7 Pb0.3Sr2Ca2−xCe
x
Cu3O10+δ system with x=0.00, 0.02, 0.04, 0.08 and 0.1 by X-ray diffraction and magnetic susceptibility. The substitution of Ce for Ca has been found
to drastically change the superconducting properties of the system. X-ray diffraction studies on these compounds indicate
decrease in the c-parameter with increased substitution of Ce at Ca site and volume fraction of high T
c (2 : 2 : 2 : 3) phase decreases and low T
c phase increases. The magnetic susceptibility of this compound shows that the diamagnetic on set superconducting transition
temperature (onset) varies from 109 K to 51 K for x=0.00, 0.02, 0.04, 0.08 and 0.1. These results suggest the possible existence of Ce in a tetravalent state rather than a trivalent
state in this system; that is, Ca2+ → Ce4+ replacement changes the hole carrier concentration. Hole filling is the cause of lowering T
c of the system. 相似文献
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A model for the transition to the radiatively improved (RI) mode triggered in tokamaks by seeding of impurities is proposed. This model takes into account that with increasing plasma effective charge the growth rate of the toroidal ion temperature gradient (ITG) instability, considered nowadays as the dominant source of anomalous energy losses in low-confinement (L) mode, decreases. As a result the plasma density profile peaks due to an inward convection generated by trapped electron turbulence. This completely quenches ITG induced transport and a bifurcation to the RI mode occurs. Conditions necessary for the L-RI transition are investigated. 相似文献