Recombination Through Different Types of Localized States in Organic Solar Cells

Recombination in bulk heterojunction solar cells is explored by observing the result of prolonged white light illumination, thermal annealing to high temperature, and chemical doping. Measurements of the photocurrent spectral response, the steady state photocurrent‐voltage characteristics, transient photoconductivity and the dark forward bias current on polymer:fullerene solar cells provide information about the density of states and the electronic properties. Illumination generates deep localized states in the interface gap, which act as recombination centers and also increase the diode ideality factor. Annealing induces both nanostructural and electronic changes. The coarsening of the domain structure reduces the probability that excitons reach the interfaces and also reduces the charge transfer absorption. At the same time annealing broadens the exponential band tails and increases the recombination rate. Doping introduces shallow states near the fullerene conduction band, which also act as recombination centers. The results show that recombination is through localized states of different character, depending on the circumstances.     

Properties of Laplace Operators for Tetrahedral Meshes

Discrete Laplacians for triangle meshes are a fundamental tool in geometry processing. The so-called cotan Laplacian is widely used since it preserves several important properties of its smooth counterpart. It can be derived from different principles: either considering the piecewise linear nature of the primal elements or associating values to the dual vertices. Both approaches lead to the same operator in the two-dimensional setting. In contrast, for tetrahedral meshes, only the primal construction is reminiscent of the cotan weights, involving dihedral angles. We provide explicit formulas for the lesser-known dual construction. In both cases, the weights can be computed by adding the contributions of individual tetrahedra to an edge. The resulting two different discrete Laplacians for tetrahedral meshes only retain some of the properties of their two-dimensional counterpart. In particular, while both constructions have linear precision, only the primal construction is positive semi-definite and only the dual construction generates positive weights and provides a maximum principle for Delaunay meshes. We perform a range of numerical experiments that highlight the benefits and limitations of the two constructions for different problems and meshes.     

Biophysical and Biochemical Comparison of Extracellular Vesicles Produced by Infective and Non-Infective Stages of Trypanosoma cruzi

Extracellular vesicles (EVs) are small lipid vesicles released by either any prokaryotic or eukaryotic cell, or both, with a biological role in cell-to-cell communication. In this work, we characterize the proteomes and nanomechanical properties of EVs released by tissue-culture cell-derived trypomastigotes (mammalian infective stage; (TCT)) and epimastigotes (insect stage; (E)) of Trypanosoma cruzi, the etiologic agent of Chagas disease. EVs of each stage were isolated by differential centrifugation and analyzed using liquid chromatography with tandem mass spectrometry (LC-MS/MS), dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), electron microscopy and atomic force microscopy (AFM). Measurements of zeta-potential were also included. Results show marked differences in the surface molecular cargos of EVs between both stages, with a noteworthy expansion of all groups of trans-sialidase proteins in trypomastigote’s EVs. In contrast, chromosomal locations of trans-sialidases of EVs of epimastigotes were dramatically reduced and restricted to subtelomeric regions, indicating a possible regulatable expression of these proteins between both stages of the parasite. Regarding mechanical properties, EVs of trypomastigotes showed higher adhesion compared to the EVs of epimastigotes. These findings demonstrate the remarkable surface remodeling throughout the life cycle of T. cruzi, which shapes the physicochemical composition of the extracellular vesicles and could have an impact in the ability of these vesicles to participate in cell communication in completely different niches of infection.     

Sustainability Index to Assess the Environmental Impact of Heat Supply Systems

A sustainable heat supply is studied by defining indicators to evaluate local heat supply systems based on renewable energies compared to fossil energy reference scenarios. Besides the energy production, the evaluation considers the heat distribution network and long‐term storage. The indicators include ecological, economic, and social aspects.     

The Footprint of Kynurenine Pathway in Neurodegeneration: Janus-Faced Role in Parkinson’s Disorder and Therapeutic Implications

Progressive degeneration of neurons and aggravation of dopaminergic neurons in the substantia nigra pars compacta results in the loss of dopamine in the brain of Parkinson’s disease (PD) patients. Numerous therapies, exhibiting transient efficacy have been developed; however, they are mostly accompanied by side effects and limited reliability, therefore instigating the need to develop novel optimistic treatment targets. Significant therapeutic targets have been identified, namely: chaperones, protein Abelson, glucocerebrosidase-1, calcium, neuromelanin, ubiquitin-proteasome system, neuroinflammation, mitochondrial dysfunction, and the kynurenine pathway (KP). The role of KP and its metabolites and enzymes in PD, namely quinolinic acid (QUIN), kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK), 3-hydroxyanthranillic acid (3-HAA), kunurenine-3-monooxygenase (KMO), etc. has been reported. The neurotoxic QUIN, N-methyl-D-aspartate (NMDA) receptor agonist, and neuroprotective KYNA—which antagonizes QUIN actions—primarily justify the Janus-faced role of KP in PD. Moreover, KP has been reported to play a biomarker role in PD detection. Therefore, the authors detail the neurotoxic, neuroprotective, and immunomodulatory neuroactive components, alongside the upstream and downstream metabolic pathways of KP, forming a basis for a therapeutic paradigm of the disease while recognizing KP as a potential biomarker in PD, thus facilitating the development of a suitable target in PD management.     

Mycoflora and ochratoxin a control in wheat grain using natural extracts obtained from wine industry by-products

The aim of this study was to evaluate the effect of some natural extracts obtained from grape pomace (GPE) and grape seeds (GSE) as compared to a synthetic food, antioxidant-butylated hydroxytoluene (BHT), in order to control fungal population and ochratoxin A (OTA) production in naturally contaminated wheat. The results showed that the addition of these extracts was efficient with OTA content decreasing. On treatment with these extracts the loss of OTA content after 14 days was in the range 7.8-28.3% relative to the control sample, but increased up to 26.48-37% after 28 days. The highest loss in OTA content was recorded for treatment with GPE at the 500 ppm level. Regarding the fungal development, the obtained results show that the total fungal populations were significantly reduced by using natural extracts. The most efficient extract was GPE. Both BHT and GPE inhibit the growth of Penicillium verrrucosum, for all doses, but less with Aspergillus genera. GPE affects the growth of other types of moulds such as Rhizopus microsporus, Fusarium graminearum, Alternaria infectoria and Cladosporium herbarum. Our data suggested that GPE and GSE are able to provide fungicidal and fungistatic protection and to control the OTA accumulation in wheat, at least in a similar manner to BHT.     

Anisotropic Point Set Surfaces

Point Set Surfaces define smooth surfaces from regular samples based on weighted averaging of the points. Because weighting is done based on a spatial scale parameter, point set surfaces apply basically only to regular samples. We suggest to attach individual weight functions to each sample rather than to the location in space. This extends Point Set Surfaces to irregular settings, including anisotropic sampling adjusting to the principal curvatures of the surface. In particular, we describe how to represent surfaces with ellipsoidal weight functions per sample. Details of deriving such a representation from typical inputs and computing points on the surface are discussed.     

"Therapist Multicultural Competency: A Study of Therapy Dyads": Correction.

Reports an error in "Therapist Multicultural Competency: A Study of Therapy Dyads" by Jairo N. Fuertes, Thomas I. Stracuzzi, Jennifer Bennett, Jennifer Scheinholtz, A. Mislowack, Mindy Hersh and David Cheng (Psychotherapy: Theory, Research, Practice, Training, 2006[Win], Vol 43[4], 480-490). The fifth author's name should be spelled as follows: Alexa Mislowack. (The following abstract of the original article appeared in record 2006-23019-010.) This study examined the role of therapist multicultural competence (TMC). Fifty-one therapy dyads completed measures of therapist multicultural competency, working alliance, and their satisfaction with therapy. Clients also completed measures of therapist attractiveness, expertness, trustworthiness, and empathy. Results showed strong associations between clients' ratings of TMC and ratings of the working alliance, therapist empathy, and satisfaction. Clients' combined rating of therapist expertness, attractiveness, and trustworthiness were not associated with their TMC ratings but were significantly associated with therapists' self-appraised TMC ratings. Therapists' ratings of their TMC were associated with their ratings of the working alliance and satisfaction with their work. Results are discussed in the context of the relevant literature, as are implications for training and research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Three-Phase Rectifier With Near Sinusoidal Input Currents and Capacitors Connected on the AC Side

An analysis of a three-phase low-harmonic diode rectifier equipped with inductors, capacitors connected on the ac side, and diodes is presented. Inductors and capacitors are used in conjunction with the three-phase diode bridge rectifier to improve the waveform of the currents drawn from the utility grid. The operation of the proposed converter is analyzed, and on this basis, design considerations are commented. The converter characteristics are determined as a function of the load current. Comparisons between the studied converter and other rectifiers (classical rectifiers with passive or active filters, three-phase rectifiers with near sinusoidal input currents and capacitors connected on the dc side, and three-phase low-harmonic rectifiers applying the third harmonic current injection) are also presented. Several possible applications of the two variants of the three-phase rectifiers with near sinusoidal input currents (with capacitors connected on the dc side or on the ac side) are mentioned. Analytically derived results are experimentally verified