71 research outputs found

    Giant Huang–Rhys Factor for Electron Capture by the Iodine Intersitial in Perovskite Solar Cells

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    Improvement in the optoelectronic performance of halide perovskite semiconductors requires the identification and suppression of nonradiative carrier trapping processes. The iodine interstitial has been established as a deep level defect and implicated as an active recombination center. We analyze the quantum mechanics of carrier trapping. Fast and irreversible electron capture by the neutral iodine interstitial is found. The effective Huang–Rhys factor exceeds 300, indicative of the strong electron–phonon coupling that is possible in soft semiconductors. The accepting phonon mode has a frequency of 53 cm–1 and has an associated electron capture coefficient of 1 × 10–10 cm3 s–1. The inverse participation ratio is used to quantify the localization of phonon modes associated with the transition. We infer that suppression of octahedral rotations is an important factor to enhance defect tolerance

    Effect of deformation on components of internal stress tensor in grains of FCC-polycristal

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    Study of contributions of internal stress tensor components in deformed of austenitic steel was carriedout. The tensor components of internal stresses were determined with using bending extinction contours observing on electron microscope images of the steel

    Per- and polyfluoroalkyl substances (PFAS) exposure and thyroid cancer risk

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    BACKGROUND: Although per- and polyfluoroalkyl substances (PFAS) exposure is a potential contributor to the increasing thyroid cancer trend, limited studies have investigated the association between PFAS exposure and thyroid cancer in human populations. We therefore investigated associations between plasma PFAS levels and thyroid cancer diagnosis using a nested case-control study of patients with thyroid cancer with plasma samples collected at/before cancer diagnosis. METHODS: 88 patients with thyroid cancer using diagnosis codes and 88 healthy (non-cancer) controls pair-matched on sex, age (±5 years), race/ethnicity, body mass index, smoking status, and year of sample collection were identified in the BioMe population (a medical record-linked biobank at the Icahn School of Medicine at Mount Sinai in New York); 74 patients had papillary thyroid cancer. Eight plasma PFAS were measured using untargeted analysis with liquid chromatography-high resolution mass spectrometry and suspect screening. Associations between individual PFAS levels and thyroid cancer were evaluated using unconditional logistic regression models to estimate adjusted odds ratios (OR adj) and 95% confidence intervals (CI). FINDINGS: There was a 56% increased rate of thyroid cancer diagnosis per doubling of linear perfluorooctanesulfonic acid (n-PFOS) intensity (OR adj, 1.56, 95% CI: 1.17-2.15, P = 0.004); results were similar when including patients with papillary thyroid cancer only (OR adj, 1.56, 95% CI: 1.13-2.21, P = 0.009). This positive association remained in subset analysis investigating exposure timing including 31 thyroid cancer cases diagnosed ≥1 year after plasma sample collection (OR adj, 2.67, 95% CI: 1.59-4.88, P < 0.001). INTERPRETATION: This study reports associations between exposure to PFAS and increased rate of (papillary) thyroid cancer. Thyroid cancer risk from PFAS exposure is a global concern given the prevalence of PFAS exposure. Individual PFAS studied here are a small proportion of the total number of PFAS supporting additional large-scale prospective studies investigating thyroid cancer risk associated with exposure to PFAS chemicals. FUNDING: National Institutes of Health grants and The Andrea and Charles Bronfman Philanthropies

    Are physical measures good indicators of clinical image quality at low dose levels? A pilot study

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    Background - For dose reduction actions, the principle of “image quality as good as possible” to “image quality as good as needed” requires to know whether the physical measures and visual image quality relate. Visual evaluation and objective physical measures of image quality can appear to be different. If there is no noticeable effect on the visual image quality with a low dose but there is a objective physical measure impact, then the overall dose may be reduced without compromising the diagnostic image quality. Low dose imaging can be used for certain types of observations, e.g. thoracic scoliosis, control after metal implantation for osteosynthesis, reviewing pneumonia and tuberculosis. Aim of the study - To determine whether physical measures of noise predict visual (clinical) image quality at low dose levels

    Social dilemmas among unequals

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    This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this record.Direct reciprocity is a powerful mechanism for evolution of cooperation, based on repeated interactions. It requires that interacting individuals are sufficiently equal, such that everyone faces similar consequences when they cooperate or defect. Yet inequality is ubiquitous among humansand is generally considered to undermine cooperation and welfar. Most previous models of reciprocity neglect inequality. They assume that individuals are the same in all relevant aspects. Here we introduce a general framework to study direct reciprocity among unequals. Our model allows for multiple sources of inequality. Subjects can differ in their endowments, their productivities, and in how much they benefit from public goods. We find that extreme inequality prevents cooperation. But if subjects differ in productivity, some endowment inequality can be necessary for cooperation to prevail. Our mathematical predictions are supported by a behavioral experiment where we vary the subjects’ endowments and their productivities. We observe that overall welfare is maximized when the two sources of heterogeneity are aligned, such that more productive individuals receive higher endowments. In contrast, when endowments and productivities are misaligned, cooperation quickly breaks down. Our findings have implications for policy-makers concerned with equity, efficiency, and public goods provisioning.European Research Council Start GrantGraph GamesAustrian Science Fund (FWF)Office of Naval ResearchJohn Templeton FoundationISTFELLOW program

    Privacy by design bij reizigersmetingen op stations

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    In maart van dit jaar ontstond discussie over het tracken en tracen van reizigers op het station van Groningen met behulp van het volgsysteem SMART Station. De projectvoerders geven uitleg over de intrinsieke privacybescherming van het systeem. SMART Station wordt binnenkort ingezet op Utrecht CS en krijgt daarna ook bredereTransport & PlanningCivil Engineering and Geoscience

    Patient-reported outcomes following total thyroidectomy and lobectomy in thyroid cancer survivors: An analysis of the profiles registry data

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    Purpose Patient-reported outcomes are important in the surgical decision-making process for low-risk, differentiated thyroid cancer. Current study aimed to assess patient-reported outcomes in thyroid cancer survivors comparing total thyroidectomy (TT) and lobectomy (LT) using the Patient Reported Outcomes Following Initial treatment and Long term Evaluation of Survivorship (PROFILES) registry. Methods European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) scales, illness perception questions, Beliefs about Medicines Questionnaire (BMQ) scales and questions about thyroid surgery–related medication use were compared between thyroid cancer patients who underwent TT versus LT using descriptive analyses. Results In total, 58 thyroid cancer patients who underwent TT or LT were included in this study. None of the EORTC QLQ-C30 scales or questions regarding illness perception were significantly different between the surgical groups. Patients in the TT group had significantly higher belief in the necessity of their medication (21.0 vs 15.4; p = 0.003) and greater concerns about taking their medicines (14.7 vs 11.1; p = 0.008) versus patients in the LT group. Conclusion Concerns about post-surgical medication use specifically in the TT group may indicate that clinicians should consider LT in patients with low-risk, differentiated thyroid cancer when LT and TT are viable surgical options. Clinicians should be aware of the impact of post-surgical medication use in particular following TT and use this knowledge to align goals of treatment with the extent of surgery, allowing for a better-informed decision-making process

    Een delta in beweging: Bouwstenen voor een klimaatbestendige ontwikkeling van Nederland

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    Nederland profiteert op vele manieren van de ligging in de delta waar de Maas en de Rijn in de Noordzee vloeien. Deze ligging betekent echter ook dat Nederland kwetsbaar is voor de gevolgen van klimaatverandering. In de afgelopen eeuwen is de Nederlandse delta voortdurend in beweging geweest en aangepast, zowel aan de eisen die het geofysische systeem stelde, als aan de wensen en mogelijkheden van een samenleving die voortdurend in verandering is. Omdat de aard en snelheid van de klimaatverandering onzeker zijn, kan de totale opgave die dit voor Nederland met zich brengt niet precies worden aangegeven. Dit rapport bevat nieuwe bouwstenen voor een klimaatbestendige ruimtelijke ontwikkeling van Nederland. Het is een vervolg op de studie Wegen naar een klimaatbestendig Nederland (PBL 2009b), waarin als speerpunten voor een klimaatbestendige ruimtelijke ontwikkeling zijn benoemd: de bescherming op de langere termijn tegen overstromingen, het veiligstellen van de zoetwatervoorziening, en het verminderen van de kwetsbaarheid voor klimaatverandering van de natuur en het stedelijk gebied
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