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On the basis of the behavioral approach system (BAS) dysregulation theory of bipolar disorder, this study examined the relation between occurrence of a BAS activation-relevant life event--goal striving--and onset of hypomanic and depressive episodes and symptoms. In particular, the authors examined the relation between preparing for and completing final exams (a goal-striving event) and onset of bipolar spectrum episodes and symptoms in college students with bipolar II disorder or cyclothymia (i.e., "soft" bipolar spectrum conditions). One hundred fifty-nine individuals with either a bipolar spectrum disorder (n=68) or no major affective psychopathology (controls; n=91) were further classified on the basis of whether they were college students (i.e., completed final exams). Consistent with the BAS dysregulation theory, preparing for and completing final exams was associated with an increase in hypomanic but not depressive episodes and symptoms in individuals with a soft bipolar spectrum diagnosis. Furthermore, self-reported BAS sensitivity moderated the presence of certain hypomanic symptoms during final exams. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Myocardial and pulmonary beta-adrenoceptors can be imaged with 2-(S)-(-)-(9H-carbazol-4-yl-oxy)-3-[1-(fluoromethyl)ethyl]amino-2- propanol (S-1'-[18F]fluorocarazolol, I). Quantification of unmodified fluorocarazolol in plasma is necessary for analysis of PET images in terms of receptor densities. We have determined I and its radioactive metabolites in rat, sheep and human plasma, using (1) solid-phase extraction (C18) followed by reversed-phase HPLC and (2) direct injection of untreated plasma samples on an internal-surface reversed-phase (ISRP) column. The two methods were in good agreement. Unmodified I decreased from over 99% initially to less than 5%, 5-10% and 20% at 60 min post-injection in rats, sheep and human volunteers, respectively. Protein binding in sheep and human plasma was determined by ultrafiltration. The fraction of total plasma radioactivity bound to protein and the fraction representing unmodified radioligand were linearly correlated, suggesting that fluorocarazolol was more than 70% protein-bound, whereas its metabolites showed negligible protein binding. Direct injection of plasma on an ISRP column seems a convenient method for quantification of lipophilic radioligands such as fluorocarazolol.  相似文献   
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Using a large database, this study examined 3 refinements of validity generalization procedures: (1) a more accurate procedure for correcting the residual standard deviation (SD) for range restriction to estimate SDp, (2) use of r? instead of study-observed rs in the formula for sampling error variance, and (3) removal of non-Pearson rs. The 1st procedure does not affect the amount of variance accounted for by artifacts. The addition of the 2nd and 3rd procedures increased the mean percentage of validity variance accounted for by artifacts from 70 to 82%, a 17% increase. The cumulative addition of all 3 procedures decreased the mean SDp estimate from .150 to .106, a 29% decrease. Six additional variance-producing artifacts were identified that could not be corrected for. In light of these it was concluded that the obtained estimates of mean SDp and mean validity variance accounted for were consistent with the hypothesis that the true mean SDp value is close to zero. These findings provide further evidence against the situational specificity hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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With the assumption that the bed shear stress fluctuates in a lognormal fashion, the probability density function (PDF) of the standardized bed shear stress is derived as a function of the relative shear stress intensity. The PDF is more skewed with larger relative intensities, but approaches a Gaussian function when the relative intensity is small. The computed PDF agrees well with the reported experimental data for flows over a smooth boundary. The higher-order moments of the bed shear stress, skewness, and kurtosis, are shown analytically to be also dependent on the relative intensity. The theoretical dependencies are then compared to a number of measurements available in the literature. The Reynolds number effect on the relative intensity is also discussed.  相似文献   
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In a previous paper (Mancini and Savassi, 1999), it was shown that every plane panel, used to brace tall building structures, can be easily and generally approached through the use of the continuous medium technique (CMT) (Albigés and Goulet, 1960). In that paper, following a so‐called local formulation, i.e., by deriving the governing differential equations system of the panel, in terms of u(z) panel horizontal displacement and wi columns or walls axial displacements, the equivalence (likeness) of formal mathematics, and hence of structural behaviour, between the panel composed by a pair of shear walls associated by lintel beams and another panel formed by the plane association, by pinned horizontal bars, of one shear wall and one single bay frame, was also shown. In both cases, axial deformations due to axial forces on vertical members were taken into account. In this paper, confirming those conclusions, but now following a global formulation (i.e., considering the total potential energy of each panel: strain energy plus applied load potentials), the mathematical equivalence between those two types of plane panels is again revealed by comparison of their two total potential energy analytical expressions. Additionally, based on that variational approach, the one‐dimensional finite element formulation is presented. This enlarges the possibilities of solutions for more general types of panels, like those with variable geometry or loading, without any further difficulty. The procedure, for any type of panel, can be codified in one single computer program, very similar to those used to solve plain continuous beam problems. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
8.
The piezoelectric ceramic (piezoceramic) component of a polymer-piezoelectric ceramic composite converts mechanical energy into electrical energy and this electrical energy is dissipated as heat in a load resistance, R x, simulated by a shunted resistance, but provided in practice by a conductive polymer composite matrix. The composite therefore dissipates the input mechanical energy via the damping mechanism provided by piezoelectric ceramic-conductive matrix material, as well as the conventional viscoelastic damping provided by the polymer. Mathematical models have been developed to characterize the damping behaviour of the composites, and the maximum damping ratio of composites can be as high as 23%. A two degrees-of-freedom (2DOF) experimental setup was developed to test the validity of the models. The experimental results are in good agreement with the theoretical predictions.  相似文献   
9.
Griseofulvin solid dispersions were prepared using polyethylene glycol 6000 (PEG), talc, and their combination as carriers by the solvent method. The dissolution of griseofulvin from these dispersions was studied. It was found that in these carriers the drug dissolution rate was a function of drug loading. The dissolution rate from dispersions prepared using PEG was similar to that from PEG/talc dispersions, especially at a low percentage of drug loading. Dispersions of PEG and PEG/talc provided dissolution rates faster than those from dispersions of talc. The incorporation of talc in PEG yielded dispersions with properties of less tackiness and ease for handling. Dissolution kinetics, based on the Hixson-Crowell equation, was used to determine the characteristics of griseofulvin particles in dispersions. Linear relationships were obtained for PEG and PEG/talc dispersions that indicated the presence of a uniformly sized monoparticulate system, whereas deviation from linearity was observed for talc dispersions. This appeared to be a multiparticulate system in which particles were present as free form and adsorbed form on the surface of talc.  相似文献   
10.
The human B lymphocyte-specific Ag, CD22, is a cell adhesion molecule expressed on the surface during a narrow window of B cell development, coincident with surface IgD. A ligand for CD22 has recently been identified on human T cells as the low molecular mass isoform of the leukocyte common Ag, CD45RO. CD22 has been reported to function in the regulation of both T and B cell activation in vitro. In this study, we report the isolation and expression of a molecular cDNA clone encoding the murine homologue of CD22, mCD22. Within their predicted protein sequences, murine and human sequences overall have 62% identity, which includes 18 of 20 extracellular cysteines and six of six cytoplasmic tyrosines. BHK cells transfected with mCD22 cDNA specifically adhere to resting and activated T lymphocytes and in addition bound activated, but not resting, B cells. Five Th clones were analyzed for their ability to adhere to mCD22; two Th0 clones and one Th1 clone bound CD22+ BHK transfectants, but not all T cell clones bound CD22+ cells: another Th1 clone and a Th2 clone did not. mCD22+ BHK transfectants were also specifically bound by the B cell-specific mAb, NIM-R6, demonstrating that this mAb is specific for murine CD22. Human cell lines expressing the counter-receptors for human CD22 were also examined for adhesion to the murine CD22 homologue; the epitope responsible for B cell adhesion to CD22 is conserved, whereas the T cell epitope binding to CD22 is not. The cDNA and mAb to murine CD22 will be useful for defining the in vivo function of CD22.  相似文献   
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