Excess volumes and excess viscosities of binary mixtures of 1-bromo-2-methylpropane + an isomer of butanol at 298.15 and 313.15 K

Excess volumesV ^E, excess viscosities ^E, and excess free energies of activation of flow G^*E at 298.15 and 313.15 K are reported for binary mixtures of 1-bronw-2-methypropane and each of the alcoholic isomers of I-butanol. The results were obtained from density and viscosity measurements and show positive values forV ⁴ and negative for both ^E andG ^*E for all mixtures over the entire composition range.     

Preexposure effects in the spatial domain: Dissociation between latent inhibition and perceptual learning.

In 4 experiments, rats were given intermixed or blocked preexposure to an array of landmarks that subsequently defined the location of a hidden goal in a Morris pool task. Previous research has shown that intermixed preexposure to pairs of adjacent landmarks retards learning whereas preexposure to individual landmarks facilitates subsequent learning (J. Prados, V. D. Chamizo, & N. J. Mackintosh, 1999). Accordingly, in Experiment 1, intermixed and blocked preexposure to pairs of adjacent landmarks was found to retard learning. In Experiment 2, however, a scheduling effect was found: Rats given intermixed preexposure to the individual landmarks learned faster than rats given blocked or no preexposure. Experiment 3 showed that intermixed (but not blocked) preexposure to pairs of landmarks resulted in a facilitatory effect when preexposure and test were carried out in different contexts. Experiment 4 replicated within a single experiment the main results observed in Experiments 1 and 3. This pattern of results suggests that intermixed preexposure engages learning processes other than latent inhibition that facilitate subsequent learning of the navigation task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative activation of stimulus representations restores lost salience: Implications for perceptual learning.

In 3 experiments, rats received preexposure to presentations of a compound flavor BX. The effective salience of B was then tested by assessing its ability to interfere with the aversion controlled by another flavor or the tendency to drink a saline solution after the induction of a salt need. It was found that the effective salience of B was maintained when during preexposure, presentations of BX alternated with presentations of X alone. This was true both when BX was presented as a simultaneous compound (Experiment 1) and as a serial compound (X→B; Experiments 2 and 3); salience was not maintained when the serial compound took the form B→X (Experiments 2 and 3a). It was argued that the salience of B declines during preexposure but is restored when presentations of X are able to activate the representation of B by way of the associative X-B link. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contribution of hepatic scintigraphy with Tc99m blood cells to the imaging diagnosis of cavernous hemangioma. Results in 48 patients

Dividing the delivery system of larger psychiatric hospitals into defined smaller catchment areas called sectors, implies a contribution to quality assurance. Continuous monitoring and evaluation of a period before and after this reorganisation, which took place in 1994 for the central region of Zürich (Psychiatric University Hospital), allows perception of expected and possible unexpected changes. All newly registered patients were recorded within a time span divided into five periods of six month five each, the last one covering the first six months after sectorisation. This design permits to answer the question as to how fast the intended changes after sectorisation occur, and also to control side effects. Results show that sectorisation resulted in a marked increase of registrations from the defined catchment area of each sector, and that the investigated institutions achieve attainment of the aim to effect a special selection of psychiatric patients characterised by considerable psycho-social deficits. The two sectors display differences in respect of socio-demographic characteristics of newly registered patients.     

Isobaric vapour-liquid equilibrium for the binary mixtures of 1-bromobutane with isomeric butanols at 40.0 and 101.3 kpa

A dynamic recirculating still was employed to measure isobaric vapour-liquid equilibrium at 40.0 and 101.3 kPa for the binary systems 1-bromobutane and each of the isomers of butanol. All mixtures show azeotropes at both pressures. The experimental VLE data are thermodynamically consistent and were correlated using Margules, Van Laar, Wilson, NRTL and UNIQUAC equations.     

The diagnostic performance of echography and CT in pancreatic diseases producing extrahepatic cholestasis

A hundred and fifty patients with jaundice and analytical suspicion of extrahepatic cholestasis were studied prospectively; history, laboratory investigation and ultrasound examination were realized. Computerized tomography was performed in 146 patients. Ultrasonography and computerized tomography findings were confirmed by CPRE o CPTH and surgery. Ultrasonography has a sensitivity of 92.6% while that of computerized tomography was 87.2% for the identification of dilated biliary ducts. The accuracy of ultrasonography was higher than the one obtained in computerized tomography in cholangiocarcinoma (sensitivity: 77.7%) and gallbladder carcinoma (sensitivity: 100%). Computerized tomography recognized choledocholithiasis (sensitivity: 83.3%) and ampullary carcinoma (sensitivity: 88.8%) with better accuracy. However for pancreatic carcinoma (sensitivity: 88.8%) and pancreatitis (sensitivity: 83.3%) both examinations had the same accuracy.     

Comparative study in the rat of the actions of different types of stress on the release of 5-HT in raphe nuclei and forebrain areas

The effects of several stress procedures on the release of 5-HT in the dorsal and median raphe nuclei (DRN and MRN, respectively) and in forebrain structures of the rat brain innervated by both nuclei have been studied using intracerebral microdialysis. Handling for 30 sec, a saline injection and forced swimming for 5 min elevated significantly the 5-HT output in the MRN. The 5-HT output in the DRN was also enhanced by a saline injection. With regard to the forebrain structure examined, handling and forced swimming increased dialysate 5-HT in the amygdala. The injection of saline induced a slight, but significant, elevation of 5-HT in the medial prefrontal cortex. In contrast, the outflow of 5-HT was significantly reduced in the ventral hippocampus and medial prefrontal cortex following forced swimming and this effect persisted well beyond the cessation of the swim session. These results indicate that the efflux of 5-HT in the MRN appears to respond to different forms of stress, whereas that in the DRN only increases after the injection of saline. The release of 5-HT in the forebrain structures is also dependent on the type of stress procedure and the region studied.     

Hemodynamic profile in severe ARDS: results of the European Collaborative ARDS Study

OBJECTIVE: Although the acute respiratory distress syndrome (ARDS) was identified as long as 30 years ago, potential therapeutic objectives have been defined from small series rather than large trials. Moreover, relationships between ARDS and hemodynamics are unclear. The European Collaborative ARDS Study was designed to identify factors influencing the pathogenesis, severity, and prognosis of ARDS. Analysis of the hemodynamic profiles collected during this study and of their contribution to the above-mentioned facets of ARDS is the focus of the present report. DESIGN: Prospective clinical study. SETTING: 38 European intensive care units (ICUs). PATIENTS AND METHODS: We collected 2758 sets of data from 586 patients, including baseline data, data on proven or suspected causes of ARDS differentiating direct and nondirect lung injury, and data on baseline status including multiple organ dysfunction (MOD) with differentiation of primary ARDS from ARDS secondary to severe systemic disorders. Events during follow-up were also recorded, including whether the acute respiratory failure did or did not improve after 24 h (groups A and B, respectively). When available, hemodynamic data were recorded at enrollment (day 0), on days 1-3, 7, 14, and 21, and at discharge or at the time of death in the ICU. RESULTS: Although the rate of pre-existing disease and the nature and rate of complications varied widely among etiologic categories, differences in the hemodynamic profile occurred only between primary and secondary ARDS. Both at inclusion and during the course of the illness, variables that were used to investigate Va/Q mismatch [arterial oxygen tension (PaO2, arterial oxygen saturation, right-to-left shunt, and the PaO2/fractional inspired oxygen (FIO2) ratio] predicted survival. High pulmonary artery pressure (PAP) and low systemic artery pressure (SAP) were also related to the prognosis. In the logistic regression model including hemodynamic and oxygen-related variables, however, the only independent predictors of survival were the ratio of right over left ventricular stroke work (RVSW/LVSW) and the PaO2/FIO2 ratio at admission. On day 2, the best prognostic model included: age [odds ratio (OR) = 1.04, p = 0.0004], opportunistic pneumonia as the cause of ARDS (OR = 3.2, p = 0.03), existence of MOD (OR = 1.9, p = 0.03), PaO2/FIO2 (OR = 0.96, p = 0.005), and RVSW/LVSW (OR = 25, p = 0.02). A high RVSW/LVSW ratio, high systolic PAP, low diastolic SAP, and low PaO2/FIO2, and increased right atrial pressure were negative prognostic indicators during follow-up. CONCLUSION: In addition to the cause of ARDS and the early time-course of lung function, a high systolic PAP and a low diastolic SAP were strong independent indicators of survival.