Effect of blend composition in BisEH-PFDTBT:PC70BM solar cells

The photovoltaic properties of bulk-heterojunction solar cells with an active layer made of an alternating fluorene copolymer, poly{[2,7-(9,9-bis-(2-ethylhexyl)-fluorene)]-alt-[5,5-(4,7-di-2′-thienyl-2,1,3-benzothiadiazole)]}, and [6,6]-phenyl-C₇₁-butyric acid methylester are investigated by varying the blend composition and the incident light power intensity. An efficient donor-acceptor intermixing is reached with donor to acceptor weight ratios of at least 1:3, while at lower acceptor content charge trapping effects are evidenced by the light intensity dependent study. Reverse bias analysis demonstrates that a major limiting factor for the performance of the investigated solar cells is represented by the poor ability of the generation of free charge carriers, attributed to the low hole mobility in the polymer phase.     

To lump or to split? Comparing individuals with traumatic and nontraumatic limb loss in the first year after amputation.

Objective: To compare individuals with traumatic (TE) vs. nontraumatic (NTE) amputation etiology on pain, psychological, and social variables over the first 12 months postamputation, and to explore changes in mean levels of and correlations between these variables over time. Participants: There were 111 adults with newly acquired limb loss. Settings: A VA medical center and a Level I trauma hospital in a large metropolitan area. Main Outcome Measures: Characteristic Pain Severity, Pain Interference, Patient Health Questionnaire depression module, Posttraumatic Stress Disorder Checklist, Social Constraints Scale, Aversive Emotional Support Scale, Centers for Disease Control and Prevention single item Social Support measure, single item loneliness measure. Results: The NTE group was significantly older, had lower income, and had greater medical comorbidity, preamputation pain, and physical disability. The etiology groups did not differ significantly in mean levels of outcome variables except that the TE group reported greater aversive emotional support at 6 and 12 months. The TE group demonstrated a quadratic change in pain interference, with highest levels at 6 months and a linear increase in social constraints. Both etiology groups showed a linear increase in PTSD symptoms over time. Correlations between physical, psychological, and social distress were observed earlier in the year for the NTE group. Conclusion: Despite significant demographic and preamputation experience differences, few differences in outcomes emerged by etiology group in the first year after amputation. Findings suggest that the year after amputation may be a time of greater change for those with traumatic amputation compared to those with nontraumatic amputation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fenton Process for Landfill Leachate Treatment: Evaluation of Biodegradability and Toxicity

The single Fenton or the Fenton process implemented in combined scheme as a posttreatment after the ferric chloride coagulation was applied for leachate collected from a real waste disposal site. Depending on the ratios of H2O2/chemical oxygen demand, H2O2/Fe2+, and pH, the Fenton oxidation or both the Fenton oxidation and the Fenton coagulation were involved in chemical oxygen demand reduction. The implementation of ferric chloride coagulation as a pretreatment stage or acidification of raw leachate did not result in the improvement of chemical oxygen demand reduction efficacy of the following Fenton process comparing with that obtained by the direct Fenton treatment of raw leachate. The direct Fenton treatment with a higher (3/1) H2O2/chemical oxygen demand ratio applied to raw leachate without pH preadjustment (H2O2/Fe2+ = 10/1), produced more oxidized organic compounds (measured as dissolved organic carbon/chemical oxygen demand ratio), more biodegradable by-products (measured as a 7-day biological oxygen demand/chemical oxygen demand ratio), and required a considerably lower dosage of NaOH for neutralization, making it preferable for the leachate treatment. Although up to a twofold reduction in the toxicity was observed after the overall Fenton process application, the treated leachate remained extremely toxic to Daphnia magna.     

Nanotechnology and nanomaterials: toxicology, risk assessment, and regulations

Nanomaterials have very unique chemical and physical properties that suggest potential health hazards, but limited health and safety information exists for engineered nanomaterials. This review identifies a need for expanding efforts for addressing health and safety concerns in nanotechnology development and in nanotoxicology of engineered nanomaterials. The efforts include research to generate data for safety evaluation, toxicologic evaluation of potential human health effects, risk assessment to support risk-management decision-making, and regulations development to protect human health and the environment. The federal government's current understanding is that existing statutory authorities are adequate to address oversight of nanotechnology and its applications. On the other hand, the present review identifies weaknesses in the current research efforts and inadequacies in existing regulations. A collaborative effort involving multidisciplinary groups is a key element to address the related needs and issues. While federal agencies with regulatory responsibilities are looked upon to develop and implement sound policies and regulations to protect public health and the environment, state agencies may be required to initiate policies which rapidly incorporate new innovations and address public concerns. To address current and futures need related to nanotechnology, the responsible state agencies need to fill the information gaps and address the health and environmental issues. In California, activities have been initiated, but legislative authority and resources are required to provide risk assessment and health protection in an efficient and timely manner.     

Quantitative measurement of urinary excretion of 3-hydroxyisovaleryl carnitine by LC-MS/MS as an indicator of biotin status in humans

Abnormally increased urinary excretion of 3-hydroxyisovaleryl carnitine (3HIA-carnitine) results from impairment in leucine catabolism caused by reduced activity of the biotin-dependent enzyme 3-methylcrotonyl-CoA carboxylase. Accordingly, urinary 3HIA-carnitine might reflect biotin status. Here, we describe an LC-MS/MS method for accurately quantitating the urinary concentration of 3HIA-carnitine at concentrations that are typical for excretion rates that are normal or only modestly increased. This method allows for high sample throughput and does not require solid-phase extraction. We used this method to provide evidence validating urinary 3HIA-carnitine as a biomarker of biotin deficiency in humans. Four healthy adult subjects were successfully made marginally biotin deficient by feeding a 30% egg white diet for 28 days. From study day 0 to 28, the mean urinary excretion of 3HIA-carnitine increased 3.5-fold (p = 0.026). These preliminary results indicate that urinary excretion of 3HIA-carnitine increases with marginal biotin deficiency. If these results are confirmed in studies involving larger numbers of subjects, urinary excretion of 3HIA-carnitine may potentially be a clinically useful indicator of biotin status.     

Optothermophysical properties of demineralized human dental enamel determined using photothermally generated diffuse photon density and thermal-wave fields

Noninvasive dental diagnostics is a growing discipline since it has been established that early detection and quantification of tooth mineral loss can reverse caries lesions in their incipient state. A theoretical coupled diffuse photon density and thermal-wave model was developed and applied to photothermal radiometric frequency responses, fitted to experimental data using a multiparameter simplex downhill minimization algorithm for the extraction of optothermophysical properties from artificially demineralized human enamel. The aim of this study was to evaluate the reliability and robustness of the advanced fitting algorithm. The results showed a select group of optical and thermal transport parameters and thicknesses were reliably extracted from the computational fitting algorithm. Theoretically derived thicknesses were accurately predicted, within about 20% error, while the estimated error in the optical and thermal property evaluation was within the values determined from early studies using destructive analyses. The high fidelity of the theoretical model illustrates its efficacy, reliability, and applicability toward the nondestructive characterization of depthwise inhomogeneous sound enamel and complex enamel caries lesions.     

Grafted glycopolymer-based receptor mimics on polymer support for selective adhesion of bacteria

A sugar-containing monomer (2-lactobionamidoethyl methacrylate, LAMA) was grafted on a polypropylene (PP) microfiltration membrane surface by UV-induced graft copolymerization. The degree of grafting can be controlled by variation of monomer concentration, UV irradiation time, and photoinitiator concentration. Fourier transform infrared spectroscopy and scanning electron microscopy were employed to confirm the surface modification on the membranes. The water contact angle was used to evaluate the hydrophilicity change of the membrane surface before and after modification. Bacteria capture experiments showed that the membrane could selectively bind E. faecalis while adhesion of S. maltophilia was not influenced by the functionalization of PP with grafted poly(LAMA). The adhesion of E. faecalis onto poly(LAMA) grafted membrane could be inhibited by 200 mM galactose solution; however, glucose solution showed no inhibition effect. Moreover, occupying sugar residues on the membrane surface primarily by a galactose targeting lectin, peanut agglutinin, could significantly suppress the following adhesion of E. faecalis. All these results clearly demonstrate that this poly(LAMA) grafted PP membrane can selectively capture E. faecalis and that this selection is based on the interaction between galactose side groups on grafted flexible functional polymer chains on the membrane surface and galactose binding protein on the E. faecalis cell membrane.     

Locating eating pathology within an empirical diagnostic taxonomy: Evidence from a community-based sample.

Existing structural models of psychopathology need to be expanded to include additional diagnostic constructs beyond mood, anxiety, substance use, and antisocial behavior disorders. The goal of this study was to locate eating disorders within a hierarchical structural model of psychopathology that is anchored by broad Internalizing and Externalizing factors. Participants were female adolescent twins (N = 1,434) from the Minnesota Twin Family Study. The authors compared the fit of 4 models in which eating disorders (a) defined their own diagnostic class, (b) represented a subclass within Internalizing, (c) formed a subclass within Externalizing, and (d) were allowed to cross-load on both Internalizing and Externalizing. In the best fitting model, eating disorders formed a subfactor within Internalizing. These findings underscore the value of developing more comprehensive empirically based models of psychopathology to increase researchers' understanding of diverse mental disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Posttraumatic stress symptoms among National Guard soldiers deployed to Iraq: Associations with parenting behaviors and couple adjustment.

Objective: In this article, we report findings from a 1-year longitudinal study examining the impact of change in posttraumatic stress disorder (PTSD) symptoms following combat deployment on National Guard soldiers' perceived parenting and couple adjustment 1 year following return from Iraq. Method: Participants were 468 Army National Guard fathers from a brigade combat team (mean age = 36 years; median deployment length = 16 months; 89% European American, 5% African American, 6% Hispanic American). Participants completed an in-theater survey 1 month before returning home from Operation Iraqi Freedom deployment (Time 1) and again 1 year postdeployment (Time 2). The PTSD Checklist—Military Version (PCL–M; Weathers, Litz, Herman, Huska, & Keane, 1993) was gathered at both times, and 2 items assessing social support were gathered at baseline only. At Time 2, participants also completed self-report measures of parenting (Alabama Parenting Questionnaire—Short Form; Elgar, Waschbusch, Dadds, & Sigvaldason, 2007), couple adjustment (Dyadic Adjustment Scale—7; Sharpley & Rogers, 1984; Spanier, 1976), parent–child relationship quality (4 items from the Social Adjustment Scale—Self-Report; Weissman & Bothwell, 1976), alcohol use (Alcohol Use Disorders Identification Test; Babor, Higgins-Biddle, Saunders, & Monteiro, 2001), and items assessing injuries sustained while deployed. Results: Structural equation modeling analyses showed that increases in PTSD symptoms were associated with poorer couple adjustment and greater perceived parenting challenges at Time 2 (both at p