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101.
F Austrup D Vestweber E Borges M L?hning R Br?uer U Herz H Renz R Hallmann A Scheffold A Radbruch A Hamann 《Canadian Metallurgical Quarterly》1997,385(6611):81-83
When activated, T helper cells differentiate into one of two subsets, Th1 and Th2, characterized by distinct profiles of cytokine production. Th1 cells activate pro-inflammatory effector mechanisms involved in protection and autoimmunity, whereas Th2 cells induce humoral and allergic responses and downregulate local inflammation. Apart from differences in the repertoire of cytokines, no phenotypic attributes are established that distinguish the two subsets. Here we show that Th1 cells, but not Th2 cells, are able to bind to P-selectin and E-selectin. Moreover, only Th1 cells can efficiently enter inflamed sites in Th1-dominated models, such as sensitized skin or arthritic joints, but not in a Th2-dominated allergic response. Immigration of Th1 cells into inflamed skin can be blocked by antibodies against P- and E-selectin. These results provide evidence for adhesion mechanisms to distinguish between the two T helper subsets and mediate their differential trafficking. They indicate that selective recruitment is an additional level of regulation for both effector function profile and character of a local immune response. 相似文献
102.
103.
Aguiar A.P. Hespanha J.P. Kokotovic P.V. 《Automatic Control, IEEE Transactions on》2005,50(2):234-239
We highlight an essential difference between path-following and reference-tracking for nonminimum phase systems. It is well known that in the reference-tracking, for nonminimum phase systems, there exists a fundamental performance limitation in terms of a lower bound on the L/sub 2/-norm of the tracking error, even when the control effort is free. We show that this is not the case for the less stringent path-following problem, where the control objective is to force the output to follow a geometric path without a timing law assigned to it. Furthermore, the same is true even when an additional desired speed assignment is imposed. 相似文献
104.
The current study is developed based on one of the types of subgrade rupture risk suggested by Selig and Waters (1994). It aims to evaluate subgrade stability railroad, which consists of the slope stability analysis of a railway yard embankment subjected to a wagon load type gondola parked on this track. This proposed analysis was taken into consideration because there are Brazilian railroads in high deterioration level. In some of these lines the tracks are submitted to increasing amount of load every year. The adopted model slope stability to the studied railroad embankments considers the rupture on circular line. It was applied the Geoslope-Slope/W software, version 6, to the evaluation of the platform-slope system. Several situations are adopted to reach the minimum safety slope, permitting to analyze the platform stability to keep railroad traffic under adequate safety level. 相似文献
105.
106.
The authors describe a 59-year-old woman who had a traumatic wound rupture 6 months following penetrating keratoplasty. While she was in the pre-operative holding area awaiting surgical repair, hemorrhagic choroidal detachments developed. Digital pressure was initiated on diagnosis of imminent expulsion of intraocular contents and maintained until repair of the wound rupture could be performed. Four months postoperatively, the patient's vision was 20/80 and her central pachymetry was 585 microns. This case demonstrates that a delayed-onset expulsive choroidal hemorrhage may be successfully managed with simple and rapid intervention based on knowledge of the disease process. 相似文献
107.
BL Wajchenberg B Liberman D Giannella Neto MY Morozimato M Semer LO Bracco LR Salgado M Knoepfelmacher MH Borges AC Pinto CE Kater AM Lengyel 《Canadian Metallurgical Quarterly》1996,45(1-2):99-107
This article reviews some recent studies on alcohol preference, dependence, metabolism and pharmacokinetics which were mainly carried out in our department. The inbred strains of mice with genetically different alcohol drinking behavior and alcohol animal model treated with the neurotoxins, 6-hydroxydopamine and 5,7-dihydroxytryptamine, are useful for a behavioral and pharmacological approach to evaluate the contribution of specific neural systems to alcohol, drug dependence mechanism and alcohol drinking behavior. The relations between alcohol preference and some physiological conditions are reviewed. On the drug-alcohol interaction, some drugs containing the chemical group = CHONO2, antimony and methamphetamine are addressed. This article also deals with recent topics in the pharmacokinetics and pharmacodynamics of alcohol. The dose-dependency of the alcohol elimination rate, the first-pass metabolism during alcohol drinking, and the pharmacodynamic model for describing pulse rate reaction to plasma acetaldehyde are discussed. 相似文献
108.
CE Aguiar IP Cadore MJ Padoin LM Barbosa-Coutinho AB Lucion 《Canadian Metallurgical Quarterly》1997,30(12):1463-1466
Immunohistochemistry was used to evaluate the effects of neonatal handling and aversive stimulation during the first 10 days of life on the number of corticotrophs in the anterior lobe of the pituitary of 11-day-old male Wistar rats. Since adult rats handled during infancy respond with reduced corticosterone secretion in response to stressors and with less behavior inhibition in novel environments, we assumed that neonatal stimulation could affect pituitary morphology during this critical period of cell differentiation. Three groups of animals were studied: intact (no manipulation, N = 5), handled (N = 5) and stimulated (submitted to 3 different aversive stimuli, N = 5). The percentage of ACTH-immunoreactive cells in the anterior lobe of the pituitary (number of ACTH-stained cells divided by total number of cells) was determined by examining three slices per pituitary in which a minimum of 200 cells were counted by two independent researchers. Although animals during the neonatal period are less reactive to stress-like stimulation in terms of ACTH and corticosterone secretion, results showed that the relative number of ACTH-stained cells of neonatal handled (0.25 +/- 0.01) and aversive stimulated (0.29 +/- 0.03) rats was not significantly different from intact (0.30 +/- 0.03) animals. Neonatal stimulation may have a differential effect on the various subpopulations of corticotroph cells in the anterior pituitary. 相似文献
109.
110.
This work presents the potential of a LaOCI porous membrane reactor for the reaction of oxidative coupling of methane. The sol-gel method provided LaOCl membranes supported on alumina tubes which presented mesoporous texture. Actually, the severe operating conditions of this reaction caused textural instability which restricted any transport effects to the macroporous domain. However, despite moderate separation effects between methane and oxygen, beneficial effects of the membrane reactor have been observed, subject to surface composition, structural and feeding configuration requirements. 相似文献