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81.
The relationship between adiposity and blood pressure has been studied among 17,067 healthy children aged 4 to 18 years old. The correlation of blood pressure with fatness, expressed as non lean body mass, is smaller than the correlation with lean body mass, especially in boys. Blood pressure association with lean body mass strongly increases during puberty growth in boys. These data suggest that during adolescence blood pressure association with weight is mainly due to growth and physical-maturation and that fatness has less influence. A careful analysis of somatic features of adolescents with high blood pressure seems necessary before advocating and improved system of weight control. Preference of blood pressure reference to height is again strengthened. 相似文献
82.
The oxidation of volatile aqueous Hg(0) in aquatic systems may be important in reducing fluxes of Hg out of aquatic systems. Here we report the results of laboratory and field experiments designed to identify the parameters that control the photooxidation of Hg(0)(aq) and to assess the possible importance of this process in aquatic systems. The concentrations of elemental and total Hg were measured as a function of time in both artificial and natural waters irradiated with a UV-B lamp. No change in Hg speciation was observed in dark controls, while a significant decrease in Hg(0) was observed in UV-B irradiated artificial solutions containing both chloride ions and benzoquinone. Significant photooxidation rates were also measured in natural samples spiked with Hg(0)(aq); the photooxidation of Hg(0) then follows pseudo first-order kinetics (k = 0.6 h(-1)). These results indicate that the previously observed Hg(II) photoreduction rates in natural waters could represent a net balance between Hg(0) photoreduction and Hg(0) photooxidation. As calculated from Hg(0) photooxidation rates, the dominant Hg(0) sink is likely to be photooxidation rather than volatilization from the water column during summer days. 相似文献
83.
84.
Andre N. Klingsheim Veborn Moen Kjell J. Hole 《Computer》2007,40(2):24-30
An increasing number of smart phones support Java 2, Micro Edition. Mobile application developers must deal with J2ME's inherent security weaknesses as well as bugs in implementations on real devices. The new Security and Trust Services API for J2ME addresses some of these challenges, although it too has shortcomings 相似文献
85.
Kubie John L.; Fenton Andre; Novikov Nicolay; Touretzky David; Muller Robert U. 《Canadian Metallurgical Quarterly》2007,121(4):751
In the cognitive mapping theory of hippocampal function, currently active place cells represent a rat's spatial location (J. O'Keefe & L. Nadel, 1978). A systematic shift of firing field locations should therefore produce a similar shift in a rat's judgment of its location. A. A. Fenton, G. Csizmadia, and R. U. Muller (2000a) recorded place cells in cylinders with 2 cue cards separated by 135°. When the separation was changed, firing fields moved systematically, as described by a vector-field equation (A. A. Fenton, G. Csizmadia, & R. U. Muller, 2000b). Given this cohesive movement of firing fields, the mapping theory predicts that a rat's decisions about the location of an unmarked goal should move after card separation changes, as described by the vector-field equation. The authors tested this reasoning with a task in which the rat earned a food reward by pausing in a small, unmarked goal zone. When cues were shifted in the absence of reward, goal choice shifts were accurately predicted by the vector-field equation, providing strong support for the notion that a rat's judgment of its spatial location is intimately related to the across-cell discharge pattern of simultaneously active place cells. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
86.
Salah T. B. Buttay C. Allard B. Morel H. Ghedira S. Besbes K. 《Power Electronics, IEEE Transactions on》2007,22(1):13-20
Commercial power diodes are optimized to feature punch-through behavior. However, a tradeoff between the width and the doping level of the diode epitaxial layer leads to various levels of optimization. For a given breakdown voltage, a shorter epitaxial layer width leads to better transient performances. Device datasheets do not cover this issue and a simple experimental setup is presented to assess the optimization conditions inside the diode epitaxial layer. Three commercial devices are tested and experimental results are confronted to device simulations. A good agreement is found 相似文献
87.
Device quality CdTe films and junctions have been studied using low-temperature photoluminescence (PL) measurements. The behavior of the PL was studied as a function of the measurement temperature and excitation intensity. The CdTe films and junctions were prepared under various deposition conditions to determine the effect of film deposition and solar cell fabrication parameters, such as the effect of oxygen, and chloride treatment. A PL band located at 1.232 eV has been attributed to the presence of oxygen. This band is present only in as-deposited samples excited at the CdTe surface. Samples annealed in the presence of CdCl2 exhibit a single PL band located at 1.42 eV. A model explaining the behavior of these bands is presented. 相似文献
88.
Andre Felipe Monteiro Marcus Vinicius Azevedo Alexandre Sztajnberg 《Journal of Systems and Software》2013
This work proposes a reusable architecture that enables the self-configuration of a supporting infrastructure for Web server clusters using virtual machines. The goal of the architecture is to ensure service quality, evaluating how broadly it complies with the application's operating restrictions and proportionally acting on the configuration of physical servers (hosts) or virtual machines. In addition, through the rational use of resources, the proposal aims at saving energy. A prototype of the architecture was developed and a performance evaluation carried out with two different resource management approaches. This evaluation shows how fully functional and advantageous the proposal is in terms of using resources, avoiding waste, yet maintaining the application's quality of service within acceptable levels. The architecture also shows to be flexible enough to accept, with a reasonable amount of effort, different resource self-configuration policies. 相似文献
89.
Sensitive and Reversible Detection of Methanol and Water Vapor by In Situ Electrochemically Grown CuBTC MOFs on Interdigitated Electrodes 下载免费PDF全文
Sumit Sachdeva Manjunath R. Venkatesh Brahim El Mansouri Jia Wei Andre Bossche Freek Kapteijn Guo Qi Zhang Jorge Gascon Louis C. P. M. de Smet Ernst J. R. Sudhölter 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(29)
The in situ electrochemical growth of Cu benzene‐1,3,5‐tricarboxylate (CuBTC) metal–organic frameworks, as an affinity layer, directly on custom‐fabricated Cu interdigitated electrodes (IDEs) is described, acting as a transducer. Crystalline 5–7 µm thick CuBTC layers are grown on IDEs consisting of 100 electrodes with a width and a gap of both 50 µm and a height of 6–8 µm. These capacitive sensors are exposed to methanol and water vapor at 30 °C. The affinities show to be completely reversible with higher affinity toward water compared to methanol. For exposure to 1000 ppm methanol, a fast response is observed with a capacitance change of 5.57 pF at equilibrium. The capacitance increases in time followed diffusion‐controlled kinetics (k = 2.9 mmol s?0.5 g?1CuBTC). The observed capacitance change with methanol concentration follows a Langmuir adsorption isotherm, with a value for the equilibrium affinity K e = 174.8 bar?1. A volume fraction f MeOH = 0.038 is occupied upon exposure to 1000 ppm of methanol. The thin CuBTC affinity layer on the Cu‐IDEs shows fast, reversible, and sensitive responses to methanol and water vapor, enabling quantitative detection in the range of 100–8000 ppm. 相似文献
90.
Alexandra Gros Landre Lavenu Jean-Luc Morel Philippe De Deurwaerdre 《International journal of molecular sciences》2021,22(21)
Microgravity, one of the conditions faced by astronauts during spaceflights, triggers brain adaptive responses that could have noxious consequences on behaviors. Although monoaminergic systems, which include noradrenaline (NA), dopamine (DA), and serotonin (5-HT), are widespread neuromodulatory systems involved in adaptive behaviors, the influence of microgravity on these systems is poorly documented. Using a model of simulated microgravity (SMG) during a short period in Long Evans male rats, we studied the distribution of monoamines in thirty brain regions belonging to vegetative, mood, motor, and cognitive networks. SMG modified NA and/or DA tissue contents along some brain regions belonging to the vestibular/motor systems (inferior olive, red nucleus, cerebellum, somatosensorily cortex, substantia nigra, and shell of the nucleus accumbens). DA and 5-HT contents were reduced in the prelimbic cortex, the only brain area exhibiting changes for 5-HT content. However, the number of correlations of one index of the 5-HT metabolism (ratio of metabolite and 5-HT) alone or in interaction with the DA metabolism was dramatically increased between brain regions. It is suggested that SMG, by mobilizing vestibular/motor systems, promotes in these systems early, restricted changes of NA and DA functions that are associated with a high reorganization of monoaminergic systems, notably 5-HT. 相似文献