Postpartum return to smoking: Staging a "suspended" behavior.

Two hundred fifty-six pregnant women who had quit smoking were classified into the precontemplation (PC), contemplation (C), preparation (PA), or action (A) stages of change for postpartum smoking cessation based on a 3-item algorithm assessing personal goals, self-efficacy, and smoking behavior. Logistic regression and event history analyses indicated group differences in return to smoking at 6 weeks and 3, 6, and 12 months postpartum. The percentage of women who returned to postpartum smoking was highest in the precontemplation stage and decreased with each subsequent stage, that is, at 6 weeks 83% of PCs, 64% of Cs, 35% of PAs, and 24% of As had returned to smoking. Results lend support for the stages of change for postpartum smoking abstinence. Stage-based interventions may be developed to assist women in maintaining abstinence postpartum. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Endothelin receptor blockade prevents the rise in pulmonary vascular resistance after cardiopulmonary bypass in lambs with increased pulmonary blood flow

BACKGROUND: Children with increased pulmonary blood flow may experience morbidity as the result of increased pulmonary vascular resistance after operations in which cardiopulmonary bypass is used. Plasma levels of endothelin-1, a potent vasoactive substance implicated in pulmonary hypertension, are increased after cardiopulmonary bypass. OBJECTIVES: In a lamb model of increased pulmonary blood flow after in utero placement of an aortopulmonary shunt, we characterized the changes in pulmonary vascular resistance induced by hypothermic cardiopulmonary bypass and investigated the role of endothelin-1 and endothelin-A receptor activation in postbypass pulmonary hypertension. METHODS: In eleven 1-month-old lambs, the shunt was closed, and vascular pressures and blood flows were monitored. An infusion of a selective endothelin-A receptor blocker (PD 156707; 1.0 mg/kg/h) or drug vehicle (saline solution) was then begun 30 minutes before cardiopulmonary bypass and continued for 4 hours after bypass. The hemodynamic variables were monitored, and plasma endothelin-1 concentrations were determined before, during, and for 6 hours after cardiopulmonary bypass. RESULTS: After 90 minutes of hypothermic cardiopulmonary bypass, both pulmonary arterial pressure and pulmonary vascular resistance increased significantly in saline-treated lambs during the 6-hour study period (P <.05). In lambs pretreated with PD 156707, pulmonary arterial pressure and pulmonary vascular resistance decreased (P <. 05). After bypass, plasma endothelin-1 concentrations increased in all lambs; there was a positive correlation between postbypass pulmonary vascular resistance and plasma endothelin-1 concentrations (P <.05). CONCLUSIONS: This study suggests that endothelin-A receptor-induced pulmonary vasoconstriction mediates, in part, the rise in pulmonary vascular resistance after cardiopulmonary bypass. Endothelin-A receptor antagonists may decrease morbidity in children at risk for postbypass pulmonary hypertension. This potential therapy warrants further investigation.     

Spectral Conformal Parameterization

We present a spectral approach to automatically and efficiently obtain discrete free‐boundary conformal parameterizations of triangle mesh patches, without the common artifacts due to positional constraints on vertices and without undue bias introduced by sampling irregularity. High‐quality parameterizations are computed through a constrained minimization of a discrete weighted conformal energy by finding the largest eigenvalue/eigenvector of a generalized eigenvalue problem involving sparse, symmetric matrices. We demonstrate that this novel and robust approach improves on previous linear techniques both quantitatively and qualitatively.     

The effect of cutaneous and deep pain on the electroencephalogram during sleep--an experimental study

The interaction between sleep and pain has been insufficiently studied, and no experiments have investigated whether pathologic sleep patterns as seen in pain patients can be replicated experimentally by well-defined pain stimuli. An experimental model would therefore be valuable for further studies on the interaction between pain and sleep. In this study, three well-defined experimental stimuli (muscle, joint, and cutaneous pain) were applied during sleep, and the electroencephalogram (EEG) pattern was quantified. The pain stimuli were applied during slow-wave sleep in 10 healthy subjects. Using nine surface recordings, the EEG was sampled before and during pain stimuli. Frequency analysis was performed, resulting in 10 EEG features describing the responses to pain. During the muscle-pain stimulus an arousal effect was observed and a decrease in delta (0.5-3.5 Hz) and sigma (12-14 Hz) as well as increases in alpha 1 (8-10 Hz) and beta (14.5-25 Hz) activities were seen. During joint pain, however, more universal EEG changes were seen with a decrease in the lowest frequency bands [delta, theta (3.5-8 Hz) and alpha 1] and an increase in the higher frequencies [alpha 2 (10-12 Hz), sigma and beta bands]. No background EEG changes were observed during the cutaneous stimulus. There were several differences in the responses from the nine EEG channels, but no derivation seemed especially sensitive to detect the evoked changes. The study highlights the complexity of pain on the sleep EEG. The experimental model has shown that pain from different body structures, as well as signals from various EEG derivations, may give different responses in sleep microstructure.     

Reducing inequities through participatory research and community empowerment

PURPOSE: To analyze the indocyanine green angiographic findings of drusen in the early stages of age-related macular degeneration. METHODS: Sixty-nine eyes of 53 consecutive patients with drusen but without exudative complications of age-related macular degeneration were studied. Drusen were classified into four groups: hard drusen, drusen derived from clusters of hard drusen (hard cluster-derived drusen and soft cluster-derived drusen), membranous drusen, and regressing drusen. An additional category was constituted by reticular pseudodrusen that could be associated with drusen of either the inner or outer macula. Results of contact lens biomicroscopy and fluorescein angiography were compared with findings on indocyanine green angiography. RESULTS: Hard drusen, either isolated hard drusen or hard cluster-derived drusen, were hyperfluorescent during indocyanine green angiography; in contrast, all sizes of soft drusen derived from clusters of hard drusen were hypofluorescent throughout the angiogram. Membranous drusen, visible on biomicroscopy and fluorescein angiography, were not visible during indocyanine green angiography. Regressing drusen may have showed hyperfluorescence at the early stages of indocyanine green angiography, but associated calcium and pigmentation were hypofluorescent. Reticular pseudodrusen were visible on red-free photographs; on midphase and late-phase indocyanine green angiography using the scanning laser ophthalmoscope only, reticular pseudodrusen were seen as a pattern of hypofluorescent dots. CONCLUSION: The indocyanine green angiographic findings add to and support the clinicopathologic classification of drusen. Indocyanine green angiography may help to distinguish the different types of drusen and may thus be of use in evaluating the risk of progressive age-related macular degeneration in patients with drusen.     

Step-gradient capillary electrochromatography

The analytical benefits of using a step-gradient in capillary electrochromatography (CEC) are demonstrated. The application of step-gradient CEC to the analysis of six diuretics of widely differing lipophilicities was evaluated and shown to result in a marked reduction in the analysis time and an improvement in the peak shape for later-eluting lipophilic components. When the step-gradient approach was performed in an automated mode, the retention time RSD for repeated injections was below 1%.     

Flame structure in aluminized wide-distribution AP composite propellants

Flame structure in wide-distribution ammonium-perchlorate (AP), hydroxyl-terminated-polybutadiene (HTPB) binder, aluminum (Al) composite propellants is studied using 2-D laminates with oxygenated binder. Very fine (2-μm) AP (FAP) is used to produce fuel-rich, matrix propellant (oxygenated binder) with a FAP/binder ratio of 75/25. Coarse AP (CAP) is simulated by pressed AP lamina. A flame-structure regime map for the CAP/oxy-fuel matrix interaction flame is generated as a function of oxy-fuel matrix thickness and pressure using high-speed video imaging analysis. The flame structure is found to be similar to that previously described using UV and IR imaging for non-aluminized laminates with split (diffusion) flame structure at high pressures (P) and low fuel thicknesses (L) and merged (partially premixed) flame structure for low P and L. The CAP/matrix flame regime boundary is shown to be correlated by Peclet number, indicating the relevance of conserved-scalar (Shvab-Zeldovich) theory with simple, global AP/hydrocarbon chemistry to describe the CAP/matrix diffusion-flame stoichiometry. Other findings include a slight stabilizing effect of Al on the 1-D premixed combustion of the marginally stable fuel-rich matrix. Also, when burning in 2-D laminates assisted slightly by the CAP/matrix interaction flame, the 75/25 matrix is found to burn flat (perpendicular to regression direction) even in the split-flame regime, in contrast to lower FAP/binder ratio matrices, which protrude into the gas-phase. Findings such as these are essential for developing a fundamental understanding of and truly predictive simulation capability for combustion of wide-distribution AP propellants, including plateau, mesa and bi-plateau propellants.     

A self-adaptive mesh refinement technique for boundary element solution of the Laplace equation.

A self-adaptive mesh refinement technique is developed for boundary element solutions of the two-dimensional Laplace equation. The method is based on error reduction and applied on the element and global level to estimate the error associated with each mesh. This adaptive technique is then utilized to analyze problems with and without singularities. Results employing constant two-dimensional boundary elements are presented.