Synthesis and structure of [{As(NBu)3}2Li6] containing an [As(NBu)3] trianion

Attempts to prepare the [As(N^tBu)₃]³⁻ trianion by the reaction of As(NMe₂)₃ with [^tBuNHLi]_n (1:3 monomer equiv.) proved unsuccessful. However, if the reaction is carried out with an excess of ^tBuNH₂ (3 equiv.) the target complex [{As(N^tBu)₃}₂Li₆] (1) is obtained. This is the first example of a complex containing an [As(NR)₃]³⁻ trianion.     

Teaching evidence-based interventions: Perceptions of influences on use in professional practice in school psychology.

This study examined perceptions of school psychologists regarding their use of evidence-based interventions in school settings after completing a graduate course in school-based psychosocial interventions. Ninety-four individuals who completed the course during the 10 years prior to the study were asked to complete a survey that focused on personal and organizational factors affecting the implementation of evidence-based interventions through assessment of (a) the extent of their use of interventions in professional school psychology practice, (b) perceptions of facilitators to implementation, and (c) perceptions of barriers to implementation. Fifty-four responded (a 57% response rate); analyses were conducted on the responses of 34 individuals who indicated that they were currently school psychologists working in schools. Results indicated that school psychologists’ personal beliefs about the interventions influenced their decisions to implement them. Several evidence-based interventions were less likely to be used in urban practice settings. Training in evidence-based interventions should address the personal and contextual issues that are related to implementation, as well as the procedures of the interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mass transfer in aerated fermentation broths in a stirred tank reactor

The volumetric mass transfer coefficients, k_La, measured in a pilot plant (0.1 m³) and an industrial (67.5 m³) fermentor during an actual fermentation process are presented. Problems related to the estimation of the phsyical properties as well as to the correlation of experimental data and to scale up procedures are discussed. Although the scale up factor was rather high, both sets of data could be represented by single correlation. Comparison of the experimental data with several available correlations demonstrated the need for pilot plant experiments and scale up procedures, since it is almost impossible to take into account all relevant system properties.     

Foreign serum-induced pancreatitis in mice. II. Secretory disturbances of acinar cells

As previously reported, pancreatic acinar cell necrosis and inflammation develop in mice a few hours after one intraperitoneal injection of foreign serum. However, sublethally injured acinar cells exhibited notable increases in both zymogen granule numbers and amylase activity, observed within 3 hours and increasing with time. These two changes were coupled with a progressive decrease in the secretory response to pilocarpine and were preceded by significant disturbances in pancreatic tissue concentrations of sodium and potassium. We conclude that (1) the granule increase results from an induced disturbance of the granule exocytosis mechanism while granule formation continues and, therefore, (2) the granule secretory process is more sensitive to the serum injury mechanism than is the zymogen synthesis process. Although the granule increases developed in acinar cells throughout most of the nonnecrotic gland and persisted for at least 24 hours, acinar cell necrosis was maximal in extent--approximately 25% of the gland in severest form--by 12 to 15 hours. We conclude, therefore, that the increase in granules is neither the primary determinant nor initiator of acinar cell death. The latter is likely caused by disturbed plasma membrane functions, sufficient in some cells to result in lethal changes in ion and fluid composition. The injury mechanism, which permits granule formation to go on in the face of impaired granule exocytosis, is yet to be worked out. The possibilities are discussed in relationship to the reactivity of foreign sera for target cell plasma membranes.     

The effects of tolbutamide on the myocardium in experimental diabetes

The effects of chronic tolbutamide treatment were examined in a diabetic animal model in which abnormal myocardial function and composition have previously been demonstrated. Eight diabetic dogs were given tolbutamide 250 mg/day orally and compared with seven untreated diabetics, five healthy dogs receiving tolbutamide, and eight normal controls. After one year, resting hemodynamic studies in the intact anesthetized state showed that treated diabetic dogs had a significantly higher left ventricular end-diastolic pressure of 12.1+/-1.3 mm Hg associated with normal end-diastolic volume, compared to 6.1+/-0.8 mm Hg in untreated diabetics (P less than 0.01) and 6.3+/-0.5 in normals. Stroke work and ejection fraction were similar to normals. Acute volume expansion revealed a larger rise of left ventricular end-diastolic pressure in treated and untreated diabetics than normals, without a significant stroke volume response in treated diabetics. Enhanced stiffness of myocardium appeared to be related to interstitial accumulation of periodic acid-Schiff staining material, further intensified in treated diabetics by triglyceride accumulation observed on electron microscopy and by chemical analysis. Thus treatment of diabetes with tolbutamide, despite improved glucose tolerance, effected further reduction of left ventricular function and altered morphology of myocardium.     

Further characterization of the complementation group B temperature-sensitive mutant of respiratory syncytial virus

ts-2, a temperature-sensitive and plaque morphology mutant of respiratory syncytial virus and sole representative of complementation group B, was compared with members of the other complementation groups of respiratory syncytial virus (group A [ts-1] and group C [ts-7]). ts-2 was found to be 10- to 1,000-fold more restricted in growth and ability to spread at restrictive temperatures (37, 38, and 39 degrees C) than at the permissive temperature (32 degrees C). In temperature shift-up experiments, the ts defect of ts-1 and other members of complementation group A was found to effect a late function that was required for at least 13 h in the replicative cycle. The ts lesion of ts-7 affected a function early in the replication cycle. In contrast, ts-2 was not temperature sensitive when studied by the shift-up technique. The discrepancy between the ts plaque property and failure to detect temperature sensitivity during the shift-up experiment was resolved when it was shown that ts-2 had a defect in adsorption or penetration or both at the restrictive temperature. Clonal analysis of revertant ts-2 showed a coordinate restoration of ts+ phenotype ans syncytium-forming capacity. It appears that ts-2 has a defect in a protein that is involved in adsorption and/or penetration of virus and is also responsible for cell fusion activity.