989 resultados para 321-2
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Interleukin 2 (IL2) is the primary growth hormone used by mature T cells and this lymphokine plays an important role in the magnification of cell-mediated immune responses. Under normal circumstances its expression is limited to antigen-activated type 1 helper T cells (TH1) and the ability to transcribe this gene is often regarded as evidence for commitment to this developmental lineage. There is, however, abundant evidence than many non-TH1 T cells, under appropriate conditions, possess the ability to express this gene. Of paramount interest in the study of T-cell development is the mechanisms by which differentiating thymocytes are endowed with particular combinations of cell surface proteins and response repertoires. For example, why do most helper T cells express the CD4 differentiation antigen?
As a first step in understanding these developmental processes the gene encoding IL2 was isolated from a mouse genomic library by probing with a conspecific IL2 cDNA. The sequence of the 5' flanking region from + 1 to -2800 was determined and compared to the previously reported human sequence. Extensive identity exists between +1 and -580 (86%) and sites previously shown to be crucial for the proper expression of the human gene are well conserved in both sequence location in the mouse counterpart.
Transient expression assays were used to evaluate the contribution of various genomic sequences to high-level gene expression mediated by a cloned IL2 promoter fragment. Differing lengths of 5' flanking DNA, all terminating in the 5' untranslated region, were linked to a reporter gene, bacterial chloramphenicol acetyltransferase (CAT) and enzyme activity was measured after introduction into IL2-producing cell lines. No CAT was ever detected without stimulation of the recipient cells. A cloned promoter fragment containing only 321 bp of upstream DNA was expressed well in both Jurkat and EL4.El cells. Addition of intragenic or downstream DNA to these 5' IL2-CAT constructs showed that no obvious regulatory regions resided there. However, increasing the extent of 5' DNA from -321 to -2800 revealed several positive and negative regulatory elements. One negative region that was well characterized resided between -750 and -1000 and consisted almost exclusively of alternating purine and pyrimidines. There is no sequence resembling this in the human gene now, but there is evidence that there may have once been.
No region, when deleted, could relax either the stringent induction-dependence on cell-type specificity displayed by this promoter. Reagents that modulated endogenous IL2 expression, such as cAMP, cyclosporin A, and IL1, affected expression of the 5' IL2-CAT constructs also. For a given reagent, expression from all expressible constructs was suppressed or enhanced to the same extent. This suggests that these modulators affect IL2 expression through perturbation of a central inductive signal rather than by summation of the effects of discrete, independently regulated, negative and positive transcription factors.
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以(CH3)2Si(OC2H5)2为前驱体,采用溶胶-凝胶与有机合成相结合的方法,制得稳定性良好的涂膜液。采用旋转涂膜法在掺钕磷酸盐激光玻璃棒端面涂制防潮膜,膜层固化后透过率达96.5%,获得的膜层表面粗糙度优良,均方根表面粗糙度(RMS)为1.659nm,平均粗糙度(RA)平均为1.321nm;在激光波长1053nm,脉冲宽度1 ns条件下膜层的激光破坏闽值可达10~14 J/cm^2。经过“神光Ⅱ”高功率激光器物理实验运行,膜层使用期为五年,并且已经在我国“神光Ⅲ”原型装置上试用。
Resumo:
Thatcher, Rhys, et al., 'Influence of blood donation on O-2 uptake on-kinetics, peak O-2 uptake and time to exhaustion during severe-intensity cycle exercise in humans', Experimental Physiology (2006) 91(3) pp.499-509 RAE2008
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Programa de la asignatura “Técnicas bibliográficas, hemerográficas y documentales I” del Departamento de Pedagogía del Sistema Universidad Abierta de la Facultad de Filosofía y Letras de la UNAM, correspondiente al semestre 2009-2.
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Tesis (Maestría en Ciencias de la Ingeniería Mecánica con Especialidad en Materiales) UANL, 2013.
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Os tumores malignos do canal anal e do anus são muito raros, não ultrapassam 2% de todos os tumores do colo, reto e anus; segundo os principais levantamentos os melanomas não ultrapassam a incidência de 0,1 a 1,2% dos tumores malignos. Os autores descrevem 2 casos de melanoma, discutindo os principais dados da literatura, enfocando os aspectos diagnósticos, tratamento, evolução e prognostico. Os indicies de cura s são baixos e com elevados índices de mortalidade a curto prazo.
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We consider effective interactions among excited spin-1/2 and spin-3/2 leptons with the usual ones. Assuming that these new leptons are lighter than the Z0, we study the constraints on their masses and compositeness scale coming from the leptonic Z0 partial width.
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We show that the partition function of the super eigenvalue model satisfies, for finite N (non-perturbatively), an infinite set of constraints with even spins s = 4, 6, . . . , ∞. These constraints are associated with half of the bosonic generators of the super (W∞/2 ⊕ W1+∞/2) algebra. The simplest constraint (s = 4) is shown to be reducible to the super Virasoro constraints, previously used to construct the model.
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Background: The role of serum metalloproteinases (MMP) after myocardial infarction (MI) is unknown. Objective: The aim of this study was to evaluate the role of serum MMP-2 and -9 as predictors of ventricular remodeling six months after anterior MI. Methods: We prospectively enrolled patients after their first anterior MI. MMP activity was assayed 12 to 72 hours after the MI. An echocardiogram was performed during the hospitalization and six months later. Results: We included 29 patients; 62% exhibited ventricular remodeling. The patients who exhibited remodeling had higher infarct size based on creatine phosphokinase (CPK) peak values (p = 0.037), higher prevalence of in-hospital congestive heart failure (p = 0.004), and decreased ejection fraction (EF) (p = 0.007). The patients with ventricular remodeling had significantly lower serum levels of inactive MMP-9 (p = 0.007) and significantly higher levels of the active form of MMP-2 (p = 0.011). In a multivariate logistic regression model, adjusted by age, CPK peak, EF and prevalence of heart failure, MMP-2 and -9 serum levels remained associated with remodeling (p = 0.033 and 0.044, respectively). Conclusion: Higher serum levels of inactive MMP-9 were associated with the preservation of left ventricular volumes, and higher serum levels of the active form of MMP-2 were a predictor of remodeling 6 months after MI. (Arq Bras Cardiol. 2013;100(4):315-321).
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The fractioning of lemon essential oil can be performed by liquid-liquid extraction using hydrous ethanol as a solvent. A quaternary mixture composed of limonene, gamma-terpinene, beta-pinene, and citral was used to simulate lemon essential oil. In this paper, we present (liquid + liquid) equilibrium data that were experimentally determined for systems containing essential oil compounds, ethanol, and water at T = 298.2 K. The experimental data were correlated using the NRTL and UNIQUAC models, and the mean deviations between calculated and experimental data were less than 0.0053 in all systems, indicating the accuracy of these molecular models in describing our systems. The results show that as the water content in the solvent phase increased, the values of the distribution coefficients decreased, regardless of the type of compound studied. However, the oxygenated compound always showed the highest distribution coefficient among the components of the essential oil, thus making deterpenation of the lemon essential oil a feasible process. (C) 2012 Elsevier Ltd. All rights reserved.
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[L. Ovčinskis]
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4 Briefe und 8 Beilagen zwischen Gerhard Tinter und Max Horkheimer, 1938; 1 Brief von Hans Tischler an Max Horkheimer, 08.12.1938; 4 Briefe zwischen Bernhard H. Titcomb und Max Horkheimer, 22.09.1935, 1935; 2 Briefe zwischen Paul Titus und Max Horkheimer, 07.06.1942, 09.06.1942; 1 Brief von Ferdinand Tönnies an Max Horkheimer, 17.10.1935; 1 Brief von Tonetti Juliette Favez, 21.11.1935; 1 Brief vom Treasury Department an Max Horkheimer, 11.02.1937; 1 Brief von Edith A. Trotter an Max Horkheimer, 13.02.1941; 2 Briefe zwischen The Twentieth Century Fund und Max Horkheimer, 22.12.1942, 02.01.1943; 4 Briefe zwischen Robert Ulich und F. Pollock, 1936, 10.04.1941, 1941; 1 Brief von Max Horkheimer an United States of America Commissioner for Immigration and Naturalisation, 01.11.1940; 1 Brief von Max Horkheimer an das United States of America Department of Agriculture, 15.01.1940; 1 Brief von Max Horkheimer an das United States of America Department of State, 07.10.1941; 1 Brief von Herbert Marcuse an das United States of America Department of State, 07.10.1941; 1 Brief von Max Horkheimer an das Universität Frankfurt Kuratorium der Johann Wolfgang Goethe Universität, 05.07.1935; 1 Briefkopie von Max Horkheimer an die Universität Frankfurt, Der Rektor, 28.07.1933; 1 Brief und 1 Beilage von der University of Buffalo an Max Horkheimer, 06.03.1940; 5 Briefe zwischen der University of California Berkeley und Max Horkheimer, 1940; 2 Briefe zwischen der University of Colorado Libraries und Max Horkheimer, 17.10.1940, 25.10.1940; 3 Briefe zwischen der University of Newark und Max Horkheimer, 1935, 08.04.1938, 1938; 6 Briefe zwischen Jiri Veltruský und Max Horkheimer, 1948-1949; 1 Brief von Leon Verhille an Max Horkheimer, 19.12.1949; 5 Briefe zwischen Salka Viertel und Max Horkheimer, 1938, 1940; 1 Heiratsanzeige von Edward Walter Violin, 1949; 1 Notiz von Max Horkheimer an Edward Walter Violin; 1 Brief von Stitschan Voehard an Max Horkheimer, 03.01.1950;
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u.a.: Platon; Künstler; Schopenhauer-Denkmal; eglische Übersetzung von "Die Welt als Wille und Vorstellung"; Wilhelm Gwinner; Arthur Schopenhauer; Giacomo Leopardi; Dante Alighieri; Johann Wolfgang von Goethe; Julius Frauenstädt;
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Liederkranz, Otto Trost, Martin Ochs