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AI Alterman PA McDermott JS Cacciola MJ Rutherford CR Boardman JR McKay TG Cook 《Canadian Metallurgical Quarterly》1998,107(3):412-422
Multistage cluster analyses with replications were used to sort score profiles of 252 methadone maintained men on 4 continuous measures of antisociality--childhood conduct disorder and adult antisocial personality disorder symptoms, the revised Psychopathy Checklist, and the Socialization scale of the California Psychological Inventory. The analysis yielded 6 replicable and temporally stable cluster groups varying in degree and pattern of antisociality. The groups were statistically compared on sets of external criterion variables--Addiction Severity Index measures of past and recent substance abuse and functioning and lifetime criminal history. Axis I and II symptomatology, anxiety and depression, object relations and reality testing, hostility, guilt, and machiavellianism. The expression of antisociality in the 6 groups and differences found among them on the external variables supported the validity of a more complex conceptualization of antisociality than is provided by antisocial personality disorder. 相似文献
995.
We have previously shown (Am. J. Respir. Crit. Care Med. 1995;152:1248-1255) that in patients needing mechanical ventilation, the load imposed on the inspiratory muscles is excessive relative to their neuromuscular capacity. We have therefore hypothesized that weaning failure may occur because at the time of the trial of spontaneous breathing there is insufficient reduction of the inspiratory load. We therefore prospectively studied patients who initially had failed to wean from mechanical ventilation (F) but had successful weaning (S) on a later occasion. Compared with S, during F patients had greater intrinsic positive end-expiratory pressure (6. 10 +/- 2.45 versus 3.83 +/- 2.69 cm H2O), dynamic hyperinflation (327 +/- 180 versus 213 +/- 175 ml), total resistance (Rmax, 14.14 +/- 4.95 versus 11.19 +/- 4.01 cm H2O/L/s), ratio of mean to maximum inspiratory pressure (0.46 +/- 0.1 versus 0.31 +/- 0.08), tension time index (TTI, 0.162 +/- 0.032 versus 0.102 +/- 0.023) and power (315 +/- 153 versus 215 +/- 75 cm H2O x L/min), less maximum inspiratory pressure (42.3 +/- 12.7 versus 53.8 +/- 15.1 cm H2O), and a breathing pattern that was more rapid and shallow (ratio of frequency to tidal volume, f/VT 98 +/- 38 versus 62 +/- 21 breaths/min/L). To clarify on pathophysiologic grounds what determines inability to wean from mechanical ventilation, we performed multiple logistic regression analysis with the weaning outcome as the dependent variable. The TTI and the f/VT ratio were the only significant variables in the model. We conclude that the TTI and the f/VT are the major pathophysiologic determinants underlying the transition from weaning failure to weaning success. 相似文献
996.
B Pulendran JL Smith M Jenkins M Schoenborn E Maraskovsky CR Maliszewski 《Canadian Metallurgical Quarterly》1998,188(11):2075-2082
Injections of soluble proteins are poorly immunogenic, and often elicit antigen-specific tolerance. The mechanism of this phenomenon has been an enduring puzzle, but it has been speculated that tolerance induction may be due to antigen presentation by poorly stimulatory, resting B cells, which lack specific immunoglobulin receptors for the protein. In contrast, adjuvants, or infectious agents, which cause the release of proinflammatory cytokines such as tumor necrosis factor alpha and interleukin 1beta in vivo are believed to recruit and activate professional antigen-presenting cells to the site(s) of infection, thereby eliciting immunity. Here we show that administration of Flt3 ligand (FL), a cytokine capable of inducing large numbers of dendritic cells (DCs) in vivo, (a) dramatically enhances the sensitivity of antigen-specific B and T cell responses to systemic injection of a soluble protein, through a CD40-CD40 ligand-dependent mechanism; (b) influences the class of antibody produced; and (c) enables productive immune responses to otherwise tolerogenic protocols. These data support the hypothesis that the delicate balance between immunity and tolerance in vivo is pivotally controlled by DCs, and underscore the potential of FL as a vaccine adjuvant for immunotherapy in infectious disease and other clinical settings. 相似文献
997.
A steep inwardly directed Na+ gradient is essential for glial functions such as glutamate reuptake and regulation of intracellular ion concentrations. We investigated the effects of glucose deprivation, chemical hypoxia, and simulated ischemia on intracellular Na+ concentration ([Na+]i) in cultured spinal cord astrocytes using fluorescence ratio imaging with sodium-binding benzofuran isophthalate (SBFI) AM. Glucose removal or chemical hypoxia (induced by 10 mM NaN3) for 60 min increased [Na+]i from a baseline of 8.3 to 11 mM. Combined glycolytic and respiratory blockage by NaN3 and 0 glucose saline caused [Na+]i to increase by 20 mM, similar to the [Na+]i increases elicited by blocking the Na+/K+-ATPase with ouabain. Recovery from large [Na+]i increases (>15 mM) induced by the glutamatergic agonist kainate was attenuated during glucose deprivation or NaN3 application and was blocked in NaN3 and 0 glucose. To mimic in vivo ischemia, we exposed astrocytes to NaN3 and 0 glucose saline containing L-lactate and glutamate with increased [K+] and decreased [Na+], [Ca2+], and pH. This induced an [Na+]i decrease followed by an [Na+]i rise and a further [Na+]i increase after reperfusion with standard saline. Similar multiphasic [Na+]i changes were observed after NaN3 and 0 glucose saline with only reduced [Na+]e. Our results suggest that the ability to maintain a low [Na+]i enables spinal cord astrocytes to continue uptake of K+ and/or glutamate at the onset of energy failure. With prolonged energy failure, however, astrocytic [Na+]i rises; with loss of their steep transmembrane Na+ gradient, astrocytes may aggravate metabolic insults by carrier reversal and release of acid, K+, and/or glutamate into the extracellular space. 相似文献
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999.
Dimitriadis C.A. Coxon P.A. Lowe A.J. Stoemenos J. Economou N.A. 《Electron Device Letters, IEEE》1991,12(12):676-678
The performance of low-pressure chemical-vapor-deposited (LPCVD) polycrystalline-silicon thin-film transistors (TFTs) can be controlled by applying a high-gate-voltage stress. The potential barrier height at the grain boundary is reduced after positive high-gate-voltage stress and then increases after negative high gate voltage stress. The experimental results indicate that Ca and Al ions or hydrogen atoms existing in the gate oxide may be able to passivate grain boundaries at the polysilicon-SiO2 interface 相似文献
1000.
Hypnotic analgesia remains an enigma. Recent neuroscience studies demonstrate that widespread distributed processing occurs in the brains of individuals experiencing pain. Emerging research and theory on the mechanisms of consciousness, along with this evidence, suggest that a constructivist framework may facilitate both pain research and the study of hypnosis. The authors propose that the brain constructs elements of pain experience (pain schemata) and embeds them in ongoing consciousness. The contents of immediate consciousness feed back to nonconscious, parallel distributed processes to help shape the character of future moments of consciousness. Hypnotic suggestion may interact with such processing through feedback mechanisms that prime associations and memories and thus shape the formation of future experience. 相似文献