138 research outputs found
Monomolecular and Bimolecular Recombination of Electron-Hole Pairs at the Interface of a Bilayer Organic Solar Cell
While it has been argued that field-dependent geminate pair recombination (GR) is important, this process is often disregarded when analyzing the recombination kinetics in bulk heterojunction organic solar cells (OSCs). To differentiate between the contributions of GR and nongeminate recombination (NGR) the authors study bilayer OSCs using either a PCDTBTtype polymer layer with a thickness from 14 to 66 nm or a 60 nm thick p-DTS(FBTTh2)(2) layer as donor material and C-60 as acceptor. The authors measure JV-characteristics as a function of intensity and charge-extraction-by-linearly-increasing-voltage-type hole mobilities. The experiments have been complemented by Monte Carlo simulations. The authors find that fill factor (FF) decreases with increasing donor layer thickness (L-p) even at the lowest light intensities where geminate recombination dominates. The authors interpret this in terms of thickness dependent back diffusion of holes toward their siblings at the donor-acceptor interface that are already beyond the Langevin capture sphere rather than to charge accumulation at the donor-acceptor interface. This effect is absent in the p-DTS(FBTTh2)(2) diode in which the hole mobility is by two orders of magnitude higher. At higher light intensities, NGR occurs as evidenced by the evolution of s-shape of the JV-curves and the concomitant additional decrease of the FF with increasing layer thickness.The authors acknowledge financial support by the Bavarian State Ministry
of Science, Research, and the Arts through the Collaborative Research
Network “Solar Technologies go Hybrid”, by the Volkswagen foundation
and by the German Science Foundation DFG through the doctoral
training center “GRK 1640.” This project further received funding from
the Universidad Carlos III de Madrid, the European Union’s Seventh
Framework Programme for research, technological development and
demonstration under grant agreement no. 600371, el Ministerio de EconomĂa y Competitividad (COFUND2014-51509), el Ministerio de
EducaciĂłn, cultura y Deporte (CEI-15-17), and Banco Santander. M.R.
additionally acknowledges support from the Hanns Seidel Foundation
for a stipend through funds from the German Ministry of Education
and Research (BMBF). T.-Q.N. thanks the Office of Naval Research
(#N000141410076) for the support. Furthermore, the authors would like
to thank the anonymous referees for helpful suggestions
Variants in a Novel Epidermal Collagen Gene (COL29A1) Are Associated with Atopic Dermatitis
Atopic dermatitis (AD) is a common chronic inflammatory skin disorder and a major manifestation of allergic disease. AD typically presents in early childhood often preceding the onset of an allergic airway disease, such as asthma or hay fever. We previously mapped a susceptibility locus for AD on Chromosome 3q21. To identify the underlying disease gene, we used a dense map of microsatellite markers and single nucleotide polymorphisms, and we detected association with AD. In concordance with the linkage results, we found a maternal transmission pattern. Furthermore, we demonstrated that the same families contribute to linkage and association. We replicated the association and the maternal effect in a large independent family cohort. A common haplotype showed strong association with AD (p = 0.000059). The associated region contained a single gene, COL29A1, which encodes a novel epidermal collagen. COL29A1 shows a specific gene expression pattern with the highest transcript levels in skin, lung, and the gastrointestinal tract, which are the major sites of allergic disease manifestation. Lack of COL29A1 expression in the outer epidermis of AD patients points to a role of collagen XXIX in epidermal integrity and function, the breakdown of which is a clinical hallmark of AD
Origin of Reduced Bimolecular Recombination in Blends of Conjugated Polymers and Fullerenes
Importance of proximity to resources, social support, transportation and neighborhood security for mobility and social participation in older adults: results from a scoping study
ABSTRACT: Background: Since mobility and social participation are key determinants of health and quality of life, it is important to identify factors associated with them. Although several investigations have been conducted on the neighborhood environment, mobility and social participation, there is no clear integration of the results. This study aimed to provide a comprehensive understanding regarding how the neighborhood environment is associated with mobility and social participation in older adults.Methods: A rigorous methodological scoping study framework was used to search nine databases from different fields with fifty-one keywords. Data were exhaustively analyzed, organized and synthesized according to the International Classification of Functioning, Disability and Health (ICF) by two research assistants following PRISMA guidelines, and results were validated with knowledge users.Results: The majority of the 50 selected articles report results of cross-sectional studies (29; 58 %), mainly conducted in the US (24; 48 %) or Canada (15; 30 %). Studies mostly focused on neighborhood environment associations with mobility (39; 78 %), social participation (19; 38 %), and occasionally both (11; 22 %). Neighborhood attributes considered were mainly 'Pro ducts and technology' (43; 86) and 'Services, systems and policies' (37; 74 %), but also 'Natural and human- made changes' (27; 54 %) and 'Support and relationships' (21; 42 %). Mobility and social participation were both positively associated with Proximity to resources and recreational facilities, Social support, Having a car or driver's license, Public transportation and Neighborhood security, and negatively associated with Poor user-friendliness of the walking environment and Neighborhood insecurity. Attributes of the neighborhood environment not covered by previous research on mobility and social participation mainly concerned 'Attitudes', and 'Services, systems and policies'.Conclusion: Results from this comprehensive synthesis of empirical studies on associations of the neighborhood environment with mobility and social participation will ultimately support best practices, decisions and the development of innovative inclusive public health interventions including clear guidelines for the creation of age-supportive environments. To foster mobility and social participation, these interventions must consider Proximity to resources and to recreational facilities, Social support, Transportation, Neighborhood security and User-friendliness of the walking environment. Future studies should include both mobility and social participation, and investigate how they are associated with 'Attitudes', and 'Services, systems and policies' in older adults, including disadvantaged older adults
The Role of Photon Energy in Free Charge Generation in Bulk Heterojunction Solar Cells
Personalized therapy for mycophenolate:Consensus report by the international association of therapeutic drug monitoring and clinical toxicology
When mycophenolic acid (MPA) was originally marketed for immunosuppressive therapy, fixed doses were recommended by the manufacturer. Awareness of the potential for a more personalized dosing has led to development of methods to estimate MPA area under the curve based on the measurement of drug concentrations in only a few samples. This approach is feasible in the clinical routine and has proven successful in terms of correlation with outcome. However, the search for superior correlates has continued, and numerous studies in search of biomarkers that could better predict the perfect dosage for the individual patient have been published. As it was considered timely for an updated and comprehensive presentation of consensus on the status for personalized treatment with MPA, this report was prepared following an initiative from members of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology (IATDMCT). Topics included are the criteria for analytics, methods to estimate exposure including pharmacometrics, the potential influence of pharmacogenetics, development of biomarkers, and the practical aspects of implementation of target concentration intervention. For selected topics with sufficient evidence, such as the application of limited sampling strategies for MPA area under the curve, graded recommendations on target ranges are presented. To provide a comprehensive review, this report also includes updates on the status of potential biomarkers including those which may be promising but with a low level of evidence. In view of the fact that there are very few new immunosuppressive drugs under development for the transplant field, it is likely that MPA will continue to be prescribed on a large scale in the upcoming years. Discontinuation of therapy due to adverse effects is relatively common, increasing the risk for late rejections, which may contribute to graft loss. Therefore, the continued search for innovative methods to better personalize MPA dosage is warranted.</p
The Human Affectome
Over the last decades, the interdisciplinary field of the affective sciences has seen proliferation rather than integration of theoretical perspectives. This is due to differences in metaphysical and mechanistic assumptions about human affective phenomena (what they are and how they work) which, shaped by academic motivations and values, have determined the affective constructs and operationalizations. An assumption on the purpose of affective phenomena can be used as a teleological principle to guide the construction of a common set of metaphysical and mechanistic assumptions—a framework for human affective research. In this capstone paper for the special issue “Towards an Integrated Understanding of the Human Affectome”, we gather the tiered purpose of human affective phenomena to synthesize assumptions that account for human affective phenomena collectively. This teleologically-grounded framework offers a principled agenda and launchpad for both organizing existing perspectives and generating new ones. Ultimately, we hope Human Affectome brings us a step closer to not only an integrated understanding of human affective phenomena, but an integrated field for affective research
Cross-sectional survey on researchers' experience in using accelerometers in health-related studies
Objectives Accelerometers are widely applied in health studies, but lack of standardisation regarding device placement, sampling and data processing hampers comparability between studies. The objectives of this study were to assess how accelerometers are applied in health-related research and problems with accelerometer hardware and software encountered by researchers. Methods Researchers applying accelerometry in a health context were invited to a cross-sectional web-based survey (August 2020-September 2020). The questionnaire included quantitative questions regarding the application of accelerometers and qualitative questions on encountered hardware and software problems. Descriptive statistics were calculated for quantitative data and content analysis was applied to qualitative data. Results In total, 116 health researchers were included in the study (response: 13.7%). The most used brand was ActiGraph (67.2%). Independently of brand, the main reason for choosing a device was that it was the standard in the field (57.1%-83.3%). In children and adolescent populations, sampling frequency was higher (mean: 73.3 Hz +/- 29.9 Hz vs 47.6 Hz +/- 29.4 Hz) and epoch length (15.0s +/- 15.6s vs 30.1s +/- 25.9s) and non-wear time (42.9 min +/- 23.7 min vs 65.3 min +/- 35.4 min) were shorter compared with adult populations. Content analysis revealed eight categories of hardware problems (battery problems, compliance issues, data loss, mechanical problems, electronic problems, sensor problems, lacking waterproofness, other problems) and five categories of software problems (lack of user-friendliness, limited possibilities, bugs, high computational burden, black box character). Conclusions The study confirms heterogeneity regarding accelerometer use in health-related research. Moreover, several hardware and software problems were documented. Both aspects must be tackled to increase validity, practicability and comparability of research
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