Depressive symptoms and readiness to quit smoking among cigarette smokers in outpatient alcohol treatment.

The authors examined whether length of alcohol abstinence and depressive symptoms were related to motivational readiness to consider smoking cessation among patients in alcohol treatment. Participants were adults (N = 253) enrolled in a smoking cessation trial. Controlling for gender, depressive symptoms, and nicotine dependence, hierarchical regression analysis of readiness scores revealed a significant interaction of days since last drink and depressive symptoms. It was found that a greater number of days since last drink was associated with greater readiness, but only among patients with low scores on the Center for Epidemiologic Studies Depression Scale (L. S. Radloff, 1977). The findings suggest that alcoholic smokers with low depressive symptoms are more receptive to quitting smoking after sustained alcohol abstinence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Weight suppression and weight rebound in ex-smokers treated with fluoxetine.

Fluoxetine's effect (30 mg, 60 mg, and placebo) on postcessation weight gain was studied among participants from a randomized, double-blind 10-week smoking cessation trial who met strict criteria for abstinence and drug levels. It was hypothesized that (a) fluoxetine would dose-dependently suppress postcessation weight gain and (b) drug discontinuation would produce dose-dependent weight rebound. During the on-drug phase, placebo participants gained weight linearly (M?=?2.61 kg), exceeding both fluoxetine groups (30-mg M?=?1.33 kg, 60-mg M?=?1.25 kg). Weight suppression was initially greater for 60 mg than 30 mg, but both were followed by weight gain. Six months off-drug produced greater dose-dependent weight rebound for 60 mg than 30 mg or placebo. Considering both on- and off-drug phases, weight gain for 60 mg of fluoxetine (M?=?6.5 kg) was comparable with that for placebo (M?=?4.7 kg) but greater than that for 30 mg (M?=?3.6 kg). Fluoxetine appears to forestall postcessation weight gain, allowing time for the weight-conscious smoker to focus on quitting smoking rather than on preventing weight gain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.     

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.     

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.     

N-PEG’ylation of chitosan via “click chemistry” reactions

N-azidated chitosan was prepared by four different methods: using azidated epichlorohydrin, sodium azide plius sodium nitrite, trifluoromethane sulfonyl azide or imidazole-1-sulfonyl azide hydrochloride. Using the two last reagents, the degree of azidation (DA) of chitosan was up to 40% and 65%, respectively. N-azidated chitosans with DA at about 60% were insoluble in aqueous and common organic solvents but dissolved in 5% LiCl solution in N-methyl-2-pyrrolidone, one of the very few solvents for chitin. Chitosan–methoxy poly(ethylene glycol) derivatives containing triazolyl moiety (chitosan-N-TMPEG comb copolymers) were prepared for the first time by coupling via 1,3-dipolar cycloaddition between pendant azide and end alkyne groups of chitosan and MPEG, respectively. Comb copolymers chitosan-N-TMPEG with degree of substitution (DS) of chitosan equal to DA of chitosan were synthesized at a certain excess of MPEG alkyne reaching DS up to 40%. “Clicking” of MPEG alkyne onto azidated chitosan was successful in binary mixture of water and methylene chloride but failed in 5% LiCl solution in N-methyl-2-pyrrolidone. Significant breakdown of chitosan backbone took place under “clicking” of MPEG in the presence of Cu(II)/ascorbate catalyst resulting in graft copolymers with bimodal MWD. Chitosan-N-TMPEG copolymers contained a certain residual amount of Cu and were soluble in acetate buffer (pH 3.7). Novel comb copolymers were characterized by FT-IR and ¹H NMR spectroscopy, SEC with triple detection, intrinsic viscosity, elemental and functional group analysis.