A morphine-paired environment alters c-Fos expression in the forebrain of rats displaying conditioned place preference or aversion.

The question of whether a common mechanism mediates both aversive and rewarding drug-paired cues is still unclear. In this study, we used a place preference conditioning paradigm to train rats to associate 1 chamber with morphine and the other chamber with saline. On the test day, rats were divided into those displaying conditioned place preferences (CPP) versus conditioned place aversion (CPA). After the test, all rats were killed and c-Fos immunocytochemistry was performed. For the control group, rats were treated with the same procedure except that the injections of morphine or saline had no association with the chambers. Compared with the control group, the CPP and CPA groups showed a significant increase of c-Fos expression in the dorsomedial striatum, central medial nucleus of the thalamus, and the basolateral amygdala. However, we saw no difference between CPP and CPA rats in any brain region examined. These results suggest that a morphine-paired environment can elicit neural activity in brain regions that are involved in emotional learning. Morphine-conditioned place preference and aversion may share a common neural circuitry elicited by a morphine-paired environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A structural model of the impact of physicians' perceptions of computers on the use of hospital information systems

A structural model is developed to specify the effects of physician perceptions of the impact of computers on their use of a computer-based hospital information system (HIS). The overall model consists of a measurement model, which assumes that the observed variables are generated by a small number of unobserved variables or factors, and a structural equation model that relates exogenous and endogenous variables hypothesized as characterizing physician use of the HIS Parameters of the model are estimated with data from 477 physicians. This approach demonstrates a powerful means of modelling processes involving variables of theoretical interest that cannot be directly observed.     

Oxidation Kinetics of Polycrystalline LaCrO3

The oxidation kinetics of polycrystalline LaCrO₃ were determined by measuring the time and temperature dependence of the weight and conductivity change of reduced samples. A region of fast diffusion followed by a smaller, slower diffusion "tail" was observed in the thermogravimetric measurements. This observation can be interpreted as the rapid diffusion along the grain boundaries and subsequent diffusion into the body of the grain. The absence of the "tail" in the conductivity measurements is due to the high hole mobility along the boundaries.     

Titanium diboride–silicon carbide–boron carbide ceramics with super‐high hardness and strength

Triplex particulate composites composed of boride and carbide ceramics were found to have high strength, hardness, and fracture toughness values. Two compositions consisting of 70:15:15 and 1:1:1 volume ratios of TiB_2, SiC, and B₄C were produced from commercially available powders by hot‐pressing. The 70:15:15 ceramic exhibited a strength of ~1.3 GPa, while the 1:1:1 ceramic had a strength of ~0.9 GPa. These strengths are comparable to super‐strong Y₂O₃‐PSZ and β‐SiAlON based composites. The Vickers’ hardness values of these ceramics were ~32 GPa for indent loads of 9.8 N. Hardness increased as indentation load decreased. The 1:1:1 ceramic had a hardness of ~53 GPa at an indentation load of 0.49 N, higher than values reported for so‐called “super‐hard” ceramics, and comparable to c‐BN.     

The role of leukocyte emigration and IL-8 on the development of lipopolysaccharide-induced lung injury in rabbits

Leukocyte emigration and alveolar macrophage-derived cytokines may contribute to lung microvascular injury associated with adult respiratory distress syndrome. We have used mAbs against cell adhesion molecules on leukocytes (anti-CD18 and anti-CD49d) or against IL-8 to investigate these contributions. Intratracheal (i.t.) instillation of LPS (50 microg/kg) caused a significant increase in bronchoalveolar lavage polymorphonuclear leukocytes (PMNs) without an increase in mononuclear cells (MNCs) or an increase in lung permeability. Injection of LPS (10 microg/kg) i.v. at 24 h after i.t. LPS caused significant increases in bronchoalveolar lavage PMNs, MNCs, IL-8, and monocyte chemotactic protein-1, as well as increases in lung permeability. Rabbits that were administered i.t. LPS followed by i.v. LPS and treated with anti-CD18 mAb had a significantly lower lung permeability index and emigration of fewer PMNs but no change in MNC emigration compared with saline treatment. Anti-IL-8 mAb treatment resulted in a significantly lower lung permeability index with no change in PMN emigration compared with no treatment. These results suggest that PMN emigration is necessary but not sufficient for the development of LPS-induced lung injury, and that IL-8 plays a significant role in PMN-dependent lung injury, independent of PMN emigration.     

Alternative separation evaluations in model rechargeable silver–zinc cells

Several varieties of standard and reinforced, cellulose-based, sausage casing films derived from wood pulp have been evaluated in model (nominal 28 A h) rechargeable silver–zinc cells. The cell performance data for both cycle life and wet stand life have been compared with cells equipped with conventional 1 mil (0.025 mm) cellophane. Although shorting was the most common failure mode in the cells with sausage casing separation, remarkably good cycle and wet life were obtained when the separation wrap also included PVA film. This paper reports the cycle and wet life comparison data for these substitute separators, with respect to conventional cellophane separation, as well as separation physical property data and silver migration rates in the cells as a function of cell life.     

Endoscopic therapy for patients with a post-operative biliary leak

Twenty-three patients with a post-operative biliary leak were treated by various endoscopic methods and results were analyzed. Leaks occurred at the cystic duct in 13 patients, at the common duct in 6 patients, and at an anomalous branch of the right hepatic duct in 4 patients. Treatments included sphincterotomy alone (4 patients), stent alone (6 patients), sphincterotomy and stent (12 patients), and sphincterotomy and nasobiliary drainage catheter (1 patient). Five patients also had supplemental percutaneous catheter drainage of a biloma. All treatments were completed successfully in the absence of major morbidity, and permanent closure of the leak occurred in 100% of cases. Endoscopic therapy for patients with a post-operative biliary leak is safe and effective and should be recommended before surgical re-exploration.     

Cardiovascular and emotional responses in women: The role of hostility and harassment.

The relation of hostility and harassment to cardiovascular and emotional responses was examined by having 51 women (aged 18–26 yrs) high and low in hostility complete a task with or without harassment. Harassed high hostile Ss showed greater systolic blood pressure (SBP) increases during task and recovery periods than did harassed low hostile Ss and nonharassed Ss. Harassed low hostile Ss evidenced greater SBP increases during task and recovery periods than did nonharassed Ss. Among high hostile women, cardiovascular elevations during the task were associated with self-reported levels of negative affect. Antagonistic hostility, relative to neurotic hostility, was positively associated with harassment-induced SBP changes. These results support the hypothesis that hostile people exhibit excessive behaviorally induced cardiovascular responses to interpersonally challenging tasks that evoke anger-related emotional states. (PsycINFO Database Record (c) 2010 APA, all rights reserved)