Hostility, the metabolic syndrome, and incident coronary heart disease.

This investigation examined the impact of hostility and the metabolic syndrome on coronary heart disease (CHD) using prospective data from the Normative Aging Study. Seven hundred seventy-four older, unmedicated men free of cardiovascular disease were included in the study. The total Cook-Medley Hostility (Ho) Scale score, anthropometric data, serum lipids, fasting insulin concentrations, blood pressure, cigarette smoking, alcohol consumption, and total dietary calories were used to predict incident CHD during a 3-year follow-up interval. Multivariate analysis indicated that only Ho positively predicted and high-density lipoprotein cholesterol level negatively predicted incident CHD. Ho's effects on CHD may be mediated through mechanisms other than factors that constitute the metabolic syndrome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lipid reactivity to stress: II. Biological and behavioral influences.

This study examined behavioral and physiological influences on lipid concentrations during acute and chronic stressors. One hundred men (n?=?92) and women (n?=?8) were tested during a chronic stressor and during 2 acute stressors. During chronic stress, diet, physical activity, exercise, and sleep were examined. During the acute stressors, catecholamines, cortisol, plasma volume, and cardiovascular responses were examined. None of the behavioral influences could explain the lipid response to chronic stress. Responses of the atherogenic lipids to acute stressors were not solely reflecting hemoconcentration of the plasma but were moderately correlated with cardiovascular, epinephrine, and cortisol reactivity. Diastolic blood pressure reactors to the acute stressors had larger lipid responses to the chronic stressor than did nonreactors. Elevations in blood lipids during stress are not artifacts and may be clinically significant. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cellular Deformations Induced by Conical Silicon Nanowire Arrays Facilitate Gene Delivery

Engineered cell–nanostructured interfaces generated by vertically aligned silicon nanowire (SiNW) arrays have become a promising platform for orchestrating cell behavior, function, and fate. However, the underlying mechanism in SiNW‐mediated intracellular access and delivery is still poorly understood. This study demonstrates the development of a gene delivery platform based on conical SiNW arrays for mechanical cell transfection, assisted by centrifugal force, for both adherent and nonadherent cells in vitro. Cells form focal adhesions on SiNWs within 6 h, and maintain high viability and motility. Such a functional and dynamic cell–SiNW interface features conformational changes in the plasma membrane and in some cases the nucleus, promoting both direct penetration and endocytosis; this synergistically facilitates SiNW‐mediated delivery of nucleic acids into immortalized cell lines, and into difficult‐to‐transfect primary immune T cells without pre‐activation. Moreover, transfected cells retrieved from SiNWs retain the capacity to proliferate—crucial to future biomedical applications. The results indicate that SiNW‐mediated intracellular delivery holds great promise for developing increasingly sophisticated investigative and therapeutic tools.     

Smoking withdrawal dynamics in unaided quitters.

Considerable research shows that withdrawal severity is inconsistently related to smoking cessation outcomes. This may result from measurement problems or failure to scrutinize important dimensions of the withdrawal experience. Two recent studies demonstrated that withdrawal elevation and variations in the time course of withdrawal were related to relapse in smokers treated with the nicotine patch (T. M. Piasecki, M. C. Fiore, & T. B. Baker, 1998). This article reports a conceptual replication and extension of those findings in unaided quitters. Evidence for temporal heterogeneity was found across different types of withdrawal symptoms. Patterns or slopes of affect and urge reports over time predicted smoking status at follow-up, as did mean elevation in withdrawal symptoms. These results suggest that affect and urge withdrawal symptoms make independent contributions to relapse and that relapse is related to both symptom severity and trajectory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How do adolescents process smoking and antismoking advertisements? A social cognitive analysis with implications for understanding smoking initiation.

Youth tobacco use has increased substantially in the United States during the past decade. This increase can be attributed, in part, to the potency of cigarette advertising and relative ineffectiveness of antismoking advertising. In this article, the authors argue that an understanding of the effects of these 2 competing forms of advertising on youth smoking is limited in current theoretical treatments and that an integrative theoretical perspective has yet to be advanced. The authors argue that the elaboration likelihood model (R.E. Petty & J.T. Cacioppo, 1986) offers a framework with sufficient explanatory power in this domain. Prevention and legislative interventions may benefit from this analysis, which ultimately may help to decrease youth tobacco use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deposition Uniformity of Coal Dust on Filters and Its Effect on the Accuracy of FTIR Analyses for Silica

Miners are exposed to silica-bearing dust which can lead to silicosis, a potentially fatal lung disease. Currently, airborne silica is measured by collecting filter samples and sending them to a laboratory for analysis. Since this may take weeks, a field method is needed to inform decisions aimed at reducing exposures. This study investigates a field-portable Fourier transform infrared (FTIR) method for end-of-shift (EOS) measurement of silica on filter samples. Since the method entails localized analyses, spatial uniformity of dust deposition can affect accuracy and repeatability. The study, therefore, assesses the influence of radial deposition uniformity on the accuracy of the method. Using laboratory-generated Minusil and coal dusts and three different types of sampling systems, multiple sets of filter samples were prepared. All samples were collected in pairs to create parallel sets for training and validation. Silica was measured by FTIR at nine locations across the face of each filter and the data analyzed using a multiple regression analysis technique that compared various models for predicting silica mass on the filters using different numbers of “analysis shots.” It was shown that deposition uniformity is independent of particle type (kaolin vs. silica), which suggests the role of aerodynamic separation is negligible. Results also reflected the correlation between the location and number of shots versus the predictive accuracy of the models. The coefficient of variation (CV) for the models when predicting mass of validation samples was 4%–51% depending on the number of points analyzed and the type of sampler used, which affected the uniformity of radial deposition on the filters. It was shown that using a single shot at the center of the filter yielded predictivity adequate for a field method, (93% return, CV approximately 15%) for samples collected with 3-piece cassettes.

Copyright 2013 American Association for Aerosol Research     

Investigation of Cut-Off Sizes and Collection Efficiencies of Portable Microbial Samplers

This research investigated the physical collection efficiencies and cut-off sizes of SMA MicroPortable, BioCulture, Microflow, Microbiological Air Sampler (MAS-100), Millipore Air Tester (MAT), SAS Super 180, and RCS High Flow portable microbial samplers when collecting Polystyrene Latex particles ranging from 0.5 to 9.8 μm in aerodynamic size. Traditional collection efficiency measurements often directly compare particle concentrations upstream and downstream of the sampler without considering the particle losses. Here, we developed a new approach which tests collection efficiencies of the sampler with and without agar collection plate loaded. This method thus allows estimating the effective collection efficiency, i.e., the fraction of incoming particles deposited onto the agar collection medium only. The experimental cut-off sizes, or d ₅₀, of the investigated samplers ranged from 1.2 μm for the RCS High Flow, 1.7 μm for the MAS-100, 2.1 μm for SAS Super 180, to 2.3 μm for MAT; for other three samplers they were close to or above 5 μm. In most cases the theoretical d ₅₀ was lower than the experimental value, which was likely due to the dissipation of impactor jets and the influence of cross-flow in the multi-nozzle impactors. For most samplers, we observed a notable difference between the collection efficiency obtained by the traditional measurement method and the effective collection efficiency. In general, all samplers collected 10% or less of 0.5 μm particles onto the agar medium. This study indicates that the use of most of the tested bioaerosol samplers may result in a substantial underestimation of bacterial concentrations, especially of single bacterial cells with diameter 0.5–1.0 μm. On the other hand, most of the investigated samplers would be more efficient when collecting larger fungal spores.     

Effect of an Ionic Air Cleaner on Indoor/Outdoor Particle Ratios in a Residential Environment

We tested a leading commercially available ionic air cleaner in a typical residential apartment to study the effect of the device on indoor/outdoor airborne particle number and mass concentration ratios. In addition, we also determined the indoor ozone and ion concentration levels. When measured during normal daily activity, the average indoor/outdoor mass concentration ratio was reduced from 1.03 to 0.73 and the number concentration ratios underwent reductions for most of the particle size fractions. However, due to a substantial inter-and intra-measurement variation in particle ratios, the observed average reductions were not statistically significant. When measurements were performed in a still room, the indoor/outdoor particle mass concentration ratio decreased from 0.9–1.4 to 0.3–0.4 in eight hours when the air cleaner was operating. Ambient ozone concentrations measured in the middle of the apartment were between 13–19 ppb during normal daily activity and the ozone levels increased to 77 ppb when measured in front of the ionic cleaner during still conditions. We also found that that there was a limited vertical diffusion of ions. The highest ion concentrations were measured at a 0.5 m height from the floor and decreased substantially with increasing measurement height. This finding may have implications for effective particle removal from a person's breathing zone. Overall, we found that the tested brand of commercially available ionic air cleaners may have the capability to remove some airborne particulate matter in actual residential settings, but its cleaning effect is reduced under normal daily activity.     

Performance Characteristics of the Aerosol Collectors of the Autonomous Pathogen Detection System (APDS)

This research analyzes the physical performance characteristics of the aerosol collectors of the autonomous pathogen detection system (APDS) that was recently developed by the Lawrence Livermore National Laboratory. The APDS is capable of continuous and fully autonomous monitoring for multiple airborne threat organisms and can be used as part of a monitoring network for urban areas and major public gatherings. The system has already been successfully tested with airborne Bacillus anthracis and Yersinia pestis biowarfare agents. The APDS aerosol collection system consists of a PM-style cap to remove large particles and a low-pressure drop virtual impactor preconcentrator positioned in front of a wetted-wall cyclone. The aerosol collectors operate at flow rates as high as 3750 l/min and collect airborne particles into 4 ml of liquid for subsequent detection. In our tests we determined the overall collection efficiency of the system by measuring the difference between inlet and outlet particle concentrations. The tests were performed with polydisperse oleic acid and monodisperse polystyrene latex (PSL) particles (0.6–3.1 µ m), and for three values of the major air flow rates in the virtual impactor (1760, 2530, and 3300 l/min), two values of the product, or cyclone, flow rates (375 and 450 l/min), and two different volumes of collection liquid (4 and 6 ml). We found that the cutoff size (d₅₀ ) of the entire collection system varied from 1.5 to 2.0 µ m when collecting PSL particles, with 3.1 µ m PSL particles being collected with efficiency of approximately 85%. When collecting oleic acid particles the d₅₀ of the entire system varied from 1.1 to 1.6 µ m. The concentration rates of the aerosol collection system were found to increase with increasing overall collection flow rate and approached one million per minute at the highest tested flowrates. Such high concentrating rates and high air sample volumes make the APDS collection system highly suitable for detecting low concentrations of airborne pathogens.