Activity and mood temperament as predictors of adolescent substance use: Test of a self-regulation mediational model.

The authors tested a mediational model of temperament dimensions and substance use with a sample of 1,826 urban adolescents, M age 12.3 years. Five scales from the Revised Dimensions of Temperament Survey (DOTS—R) were administered together with measures of substance (tobacco, alcohol, marijuana) use and measures of related variables derived from a self-regulation model. Unique contributions to substance use were found for DOTS—R dimensions of high activity level (positively related) and positive mood (inversely related). High activity level and low positive mood were also related to lower levels of parental support. Analyses, including multiple regression and structural modeling, identified generalized self-control, maladaptive coping (anger and helplessness), novelty seeking, and affiliation with peer substance users as mediating the effect of temperament on substance use, with control for effects of parental support. Parental support was inversely related to substance use through several pathways. Implications for the theory of vulnerability are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incidence of normal hearing in acoustic neuroma]

In a 4 1/2 year period fetal, echocardiographic studies were performed on 1600 fetuses. In 55 with arrhythmia, 44 had supraventricular ectopic beats, resolved in all, and none had heart disease. Sustained arrhythmias occurred in 11 fetuses. Atrial flutter was present in 3 all with heart disease (Ebstein disease, right atrial tumour and WPW diagnosed after birth). Another 3 fetuses had supraventricular tachycardia (SVT), all with a normal heart. In the bradycardia group, 2 had complete heart block (CHB) associated with AVSD; 2 sinus bradycardia and one had non conducted atrial ectopic beats. Digoxin was the first choice drug for tachyarrhythmia therapy; association with Verapamil, Flecainide, Quinidine and Procainamide was used in 4 of the 6. One fetus with CHB received Orciprenaline with no results. Atrial flutter resolved or improved; in SVT 2 fetuses converted to sinus rhythm and one died in utero. All fetuses with CHB died in cardiac failure. Mortality was 27% (3 cases) in utero and global 36%. In our experience most fetal arrhythmias (90%) were transitory ectopic beats or non lasting bradycardia in normal heart and did not trigger other kinds of arrhythmias. In sustained arrhythmias, heart failure and heart disease had a negative effect on prognosis.     

From the Boltzmann equation to fluid mechanics on a manifold

We apply the Chapman-Enskog procedure to derive hydrodynamic equations on an arbitrary surface from the Boltzmann equation on the surface.     

Development of mixed matrix membranes for controlled release of ibuprofen

In this work was studied the effect of different zeolite topologies on the release of ibuprofen from mixed matrix membranes (MMMs). The main parameters investigated were: zeolite concentration, its hydrophilic/hydrophobic character, and drug loading. About the different investigated systems, the PDMS NaX (I) membrane seems to be the most promising for its application as transdermal device. The release data were fitted with different mathematical models (zero order, first order, Higuchi, Bhaskar, and Korsemeyer‐Peppas) to give a possible explanation of the release mechanism of the drug from MMMs. The release data of the drug from pure PDMS membranes (PDMS IBU) were fitted by the Higuchi model (R² pari a 0.97). In the case of MMMs, the correlation coefficients are very far from the unit value except for the PDMS NaX (I) system that obeys to the Korsmeyer–Peppas (0.98) and Bashkar (0.99) models. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Fluorescent Benzofurazan–Cholic Acid Conjugates for in vitro Assessment of Bile Acid Uptake and Its Modulation by Drugs

Fluorescent synthetic 7‐nitrobenzo‐2‐oxa‐1,3‐diazole (NBD) conjugates of cholic acid were prepared and characterized. Their photophysical properties make them suitable for monitoring uptake in freshly isolated rat hepatocytes using flow cytometry. This technique makes it possible to screen drug candidates for cholestatic (and thus hepatotoxic) liability.

     

Cytotoxicity study of some Ti alloys used as biomaterial

An implanted material is considered biocompatible, if adverse and uncontrollable reactions don't exist in the biological system. In this sense, biocompatibility tests made in the constituent materials are very important so that the implants have success. The in vitro cytotoxicity tests represent the initial phase of the process, and could be considered as a pre-selection of those materials. In vitro techniques using cell culture have become widely used in the evaluation of biomaterial cytotoxicity, which has contributed to their standardization and the substitution of in vivo tests. This paper shows a study of the in vitro cytotoxicity of two Ti based alloys, Ti–13Nb–13Zr and Ti–35Nb–7Zr–5Ta, in the as-received condition and after heat treated. The results show that the alloys presented no cytotoxic effects in the studied conditions.