The effects of community policies to reduce youth access to tobacco

The aim of this in vitro study was to investigate the effect of troglitazone, a new oral antidiabetic agent, on LDL catabolism. HepG2 cells, which are cells from a well-differentiated cell line of hepatoma cells, were cultured and used to study LDL catabolism. Different concentrations of troglitazone, all within the therapeutic range for humans, were incubated in culture medium with 125I-labeled LDL to measure cell-associated and degraded 125I-LDL. Troglitazone increased cell-associated and degraded 125I-LDL by approximately 30%. We also investigated if this effect occurred through a LDL receptor-mediated pathway or a non-LDL receptor pathway. By using dextran sulfate, a substance known to release bound LDL from its receptor, we found that troglitazone upregulated LDL receptor activity by approximately 35%. In addition, we found that troglitazone increased the expression of the LDL receptor mRNA. The effect of troglitazone was comparable with that of a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, fluvastatin, with troglitazone having an upregulatory effect similar to that of fluvastatin. Insulin within human physiological concentrations also increased LDL receptor activity. We found that troglitazone and insulin had an additive effect on LDL catabolism. Also, the effect of troglitazone on LDL catabolism was studied in the presence of cyclosporine, an immunosuppressant drug that reduces LDL catabolism mainly by decreasing LDL receptor activity. The results showed that troglitazone can compensate for the reduced LDL receptor activity induced by cyclosporine, but that cyclosporine had a residual effect on the action of troglitazone. Thus troglitazone enhanced LDL binding, cell association, and degradation by increasing LDL receptor mRNA expression, with a subsequent increase in LDL receptor activity.     

Vibration-Rotation Structure in Absorption Bands for the Calibration of Spectrometers From 2 to 16 Microns

Suitable bands of common gases have been tabulated and remeasured wherever necessary from 2 to 16 microns to obtain an accuracy of about 0.03 cm⁻¹ throughout the region and to provide good calibrating points at frequent intervals. Some 600 rotation-vibration lines are illustrated in 20 spectrograms and wavenumbers are listed in companion tables with considerable intercomparison with worthy data obtained in other laboratories. The absorpotion bands were remeasured or calibrated by using either a precisely graduated grating circle or standard atomic lines with the fringe system formed by a Fabry-Perot interferometer. Characteristic features of the individual bands are discussed briefly and references to other publications are given. The substances used for calibration include H₂O, CO₂, CO, HCl, HBr, NH₃, C₂H₂, CH₄, N₂O, and polystyrene film.     

RORSCHACH IN RELATION TO OUTCOME IN PSYCHOTHERAPY WITH COLLEGE STUDENTS.

FOCUSES ON RORSCHACH FACTORS RELATED TO OUTCOME AND DURATION OF PSYCHOTHERAPY WITH 50 MALE COLLEGE STUDENTS. SPECIFIC RORSCHACH SIGNS BASED ON PREVIOUS RESEARCH AND THE KLOPFER RORSCHACH PROGNOSTIC RATING SCALE DID NOT DISTINGUISH BETWEEN THE OUTCOME OR DURATION GROUPS. A DISCRIMINANT-FUNCTION APPROACH USING TOTAL K, M, AND R WAS THE MOST PRODUCTIVE, WITH SIGNIFICANT DIFFERENCES BETWEEN THE NO CHANGE GROUP AND BOTH CHANGE (P     

Some Effects of Aging on the Surface Area of Portland Cement Paste

A hardened cement paste cured at room temperature, from which part of the evaporable water has been removed by vacuum drying, has been studied. The surface area has been shown to decrease with time depending upon the amount of evaporable water left in the paste. This change is the opposite of that usually observed during hydration and probably represents some collodial growth phenomena analogous to aging observed in other collodial gels. Both water vapor and nitrogen adsorption measurements have been used to show the effects of aging in cement paste.Wet or dry paste is shown to undergo less change than paste of intermediate evaporable water content, so that if surface area after storage is plotted as a function of evaporable water content, a curve with a minimum is obtained. With increasing storage temperature there is some indication that this minimum might shift towards lower water content.Aging is shown to occur during the initial drying of a cement paste, so that even the initial surface area of a cement paste depends upon the manner in which the paste has been dried.     

Social exchange of cigarettes by youth

Objective: This study seeks to determine the magnitude, nature, and correlates of social exchange of cigarettes among youth who smoke.     

Dynamical models for psychological assessment: Phase space functions.

This article examines the implications of phase space functions for psychological assessment. Behavior problems, causal variables, and causal relationships are dynamic and demonstrate complex nonlinear and discontinuous relationships. Measuring the temporal, dynamic, and nonlinear dimensions of variables can enhance the accuracy of predictions of the future time course of variables and of the strength of causal relationships for behavior problems. Cross-sectional, longitudinal, and time series research designs are prone to inferential errors because they often fail to consider the dynamic time course functions of variables. The value of a variable (its state) coupled with the current direction and rate of change of the variable (its phase), at a single measurement point, is its phase state. Equal state values across persons on a variable dimension does not mean that those persons are in equal phases on that variable dimension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

CONSUMPTION OF THE MOLECULAR OXYGEN IN POLYMERIZATION SYSTEMS USING PHOTOSENSITIZED OXIDATION OF DIMETHYLANTHRACENE

It is well known that the presence of oxygen in free radical polymerization systems leads to an inhibition period and a lowered ultimate conversion. In this contribution, we report a method for consuming molecular oxygen photochemically before the polymerization takes place, thereby allowing the reaction to proceed in an oxygen-free environment. The method is based on the generation of singlet oxygen by reaction of the ground state oxygen with the excited triplet state of the singlet oxygen generator (a porphyrin, Znttp). The singlet oxygen is then consumed by reaction with a second compound (the singlet oxygen trapper, dimethylanthracene). The possible factors that might affect the efficiency of the singlet oxygen generation/trapping processes were discussed and the effectiveness of a dimethylanthracene/Znttp combination for consumption of oxygen was investigated in two acrylate systems of different viscosity.     

DNA‐Directed Assembly of Antibody–Fluorophore Conjugates for Quantitative Multiparametric Flow Cytometry

Multiparametric flow cytometry offers a powerful approach to single‐cell analysis with broad applications in research and diagnostics. Despite advances in instrumentation, progress in methodology has lagged. Currently there is no simple and efficient method for antibody labeling or quantifying the number of antibodies bound per cell. Herein, we describe a DNA‐directed assembly approach to fluorescent labeling that overcomes these barriers. Oligonucleotide‐tagged antibodies and microparticles can be annealed to complementary oligonucleotides bearing fluorophores to create assay‐specific labeling probes and controls, respectively. The ratio of the fluorescence intensity of labeled cells to the control particles allows direct conversion of qualitative data to quantitative units of antibody binding per cell. Importantly, a single antibody can be labeled with any fluorophore by using a simple mix‐and‐match labeling strategy. Thus, any antibody can provide a quantitative probe in any fluorescent channel, thus overcoming major barriers to the use of flow cytometry as a technique for systems biology and clinical diagnostics.     

Three-dimensional transport imaging for the spatially resolved determination of carrier diffusion length in bulk materials

A contact-free optical technique is developed to enable a spatially resolved measurement of minority carrier diffusion length and the associated mobility-lifetime (μτ) product in bulk semiconductor materials. A scanning electron microscope is used in combination with an internal optical microscope and imaging charge-coupled device (CCD) to image the bulk luminescence from minority carrier recombination associated with one-dimensional excess carrier generation. Using a Green's function to model steady-state minority carrier diffusion in a three-dimensional half space, non-linear least squares analysis is then applied to extract values of carrier diffusion length and surface recombination velocity. The approach enables measurement of spatial variations in the μτ product with a high degree of spatial resolution.