166 research outputs found

    Measurements of Parameters Controlling the Emissions of Organophosphate Flame Retardants in Indoor Environments

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    Emission of semivolatile organic compounds (SVOCs) from source materials usually occurs very slowly in indoor environments due to their low volatility. When the SVOC emission process is controlled by external mass transfer, the gas-phase concentration in equilibrium with the material (<i>y</i><sub>0</sub>) is used as a key parameter to simplify the source models that are based on solid-phase diffusion. A material-air-material (M-A-M) configured microchamber method was developed to rapidly measure <i>y</i><sub>0</sub> for a polyisocyanurate rigid foam material containing organophosphate flame retardants (OPRFs). The emission test was conducted in 44 mL microchambers for target OPFRs, including tris­(2-chloroethyl) phosphate (CASRN: 115-96-8), tris­(1-chloro-2-propyl) phosphate (CASRN: 13674-84-5), and tris­(1,3-dichloro-2-propyl) phosphate (CASRN: 13674-87-8). In addition to the microchamber emission test, two other types of tests were conducted to determine <i>y</i><sub>0</sub> for the same foam material: OPFR diffusive tube sampling tests from the OPFR source foam using stainless-steel thermal desorption tubes and sorption tests of OPFR on an OPFR-free foam in a 53 L small chamber. Comparison of parameters obtained from the three methods suggests that the discrepancy could be caused by a combination of theoretical, experimental, and computational differences. Based on the <i>y</i><sub>0</sub> measurements, a linear relationship between the ratio of <i>y</i><sub>0</sub> to saturated vapor pressure concentration and material-phase mass fractions has been found for phthalates and OPFRs

    Elucidating the role of WRKY27 in male sterility in Arabidopsis

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    <p>The WRKY proteins belong to a superfamily of TFs that play pivotal roles in responses to a wide range of biotic, abiotic, developmental and physiologic cues. Here, we assayed the accumulation of basal <i>WRKY27</i> transcripts in diverse tissue including root, shoot, leaf and flowers. We demonstrated that plants over-expressing <i>WRKY27</i> transcript levels exhibit growth aberrations and fertility defects. Scanning electron microscopic data suggest that <i>WRKY27</i> overexpressor plants exhibit pollen dehiscence defects. Our fluorescein diacetate hydrolysis assay showed that flowers of plants overexpressing <i>WRKY27</i> display significantly decreased pollen viability. These sterility-related phenotypes were not rescued by the exogenous applications of different phytohormones. Our results indicate the involvement of WRKY27 in particular for proper plant biomass accumulation and male fertility.</p

    2D/1A Strategy to Regulate Film Morphology for Efficient and Stable Nonfullerene Organic Solar Cells

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    Recently, the ternary blend method has been successfully applied to nonfullerene organic solar cells (OSCs) and enhanced the device performance by utilizing complementary optical absorption. Here we demonstrate the two polymer donors and one small-molecule acceptor (i.e., 2D/1A) strategy to finely regulate the blend film morphology in fullerene-free OSCs. One crystalline polymer donor, PffBT4T–2OD, can act as an effective morphology regulator for a benchmark blend of PTB7–Th and ITIC, leading to appropriate phase-separated morphology, suppressed charge recombination, efficient charge transport and high carrier mobility. The resulting solvent additive- and annealing-free fabricated bulk-heterojunction OSCs show the best power conversion efficiency (PCE) of 8.22% with a significant increase of fill factor compared to their binary counterparts. Importantly, such ternary OSCs when processed under ambient condition retain excellent device performance with a PCE of 7.57%, indicative of good air-stability

    An approach to (±)-Lingzhiol

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    (±)-Lingzhiol has been synthesized from commercially available 5,8-dimethoxytetralone in seven steps with an overall yield of 10.3% via an unprecedented acid-catalyzed semipinacol-type rearrangement. In addition, a novel strategy for the construction of the tetracyclic 5/5/6/6 core structure of lingzhiol has been developed via a tandem rearrangement/reduction/lactonization reaction

    Table_1_Predictive factors and prognosis of immune checkpoint inhibitor-related pneumonitis in non-small cell lung cancer patients.docx

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    ObjectiveTo investigate the influencing factors and prognosis of immune checkpoint inhibitor-related pneumonitis (CIP) in advanced non-small cell lung cancer (NSCLC) patients during or after receiving immune checkpoint inhibitors(ICIs).MethodsThe clinical and laboratory indicator data of 222 advanced NSCLC patients treated with PD-1/PD-L1 inhibitors at the First Affiliated Hospital of Zhengzhou University between December 2017 and November 2021 were collected retrospectively. The patients were divided into a CIP group (n=41) and a non-CIP group (n=181) according to whether they developed CIP or not before the end of follow-up. Logistic regression was used to evaluate risk factors of CIP, and Kaplan‒Meier curves were used to describe the overall survival (OS) of different groups. The log-rank test was used to compare the survival of different groups.ResultsThere were 41 patients who developed CIP, and the incidence rate of CIP was 18.5%. Univariate and multivariate logistic regression analyses showed that low pretreatment hemoglobin (HB) and albumin (ALB) levels were independent risk factors for CIP. Univariate analysis suggested that history of chest radiotherapy was related to the incidence of CIP. The median OS of the CIP group and non-CIP were 15.63 months and 30.50 months (HR:2.167; 95%CI: 1.355-3.463, PConclusionLower pretreatment HB and ALB levels were independent risk factors for CIP. A high NLR level, a low ALB level and the development of CIP were independent risk factors for the prognosis of advanced NSCLC patients treated with ICIs.</p

    Knowledge mapping of immunotherapy for breast cancer: A bibliometric analysis from 2013 to 2022

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    Breast cancer is the leading cause of cancer-related death among women globally. Immunotherapy has emerged as a major milestone in contemporary oncology. This study aims to conduct a bibliometric analysis in the field of immunotherapy for breast cancer, providing a comprehensive overview of the current research status, identifying trends and hotspots in research topics. We searched and retrieved data from the Web of Science Core Collection, and performed a bibliometric analysis of publications on immunotherapy for breast cancer from 2013 to 2022. Current status and hotspots were evaluated by co-occurrence analysis using VOSviewer. Evolution and bursts of knowledge base were assessed by co-citation analysis using CiteSpace. Thematic evolution by bibliometrix package was used to discover keywords trends. The attribution and collaboration of countries/regions, institutions and authors were also explored. A total of 7,975 publications were included. In co-occurrence analysis of keywords, 6 major clusters were revealed: tumor microenvironment, prognosis biomarker, immune checkpoints, novel drug delivery methods, immune cells and therapeutic approaches. The top three most frequently mentioned keywords were tumor microenvironment, triple-negative breast cancer, and programmed cell death ligand 1. The most productive country, institution and author were the USA (2926 publications), the University of Texas MD Anderson Cancer Center (219 publications), and Sherene Loi (28 publications), respectively. There has been a rapid growth in studies on immunotherapy for breast cancer worldwide. This research area has gained increasing attention from different countries and institutions. With the rising incidence of breast cancer, immunotherapy represents a research field of significant clinical value and potential.</p

    Concise and efficient synthesis of eliglustat

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    <p>Eliglustat, a ceramide glucosyltransferase inhibitor, was synthesized in six steps with 28.4% overall yield. The key features include the use of a diastereoselective aldol reaction to construct two contiguous stereocenters and a selective sulfonylation of a 1,3-diol catalyzed by dibutyltin oxide.</p

    Enhanced Electrochemical Performance of Li<sub>1.2</sub>Mn<sub>0.54</sub>Ni<sub>0.13</sub>Co<sub>0.13</sub>O<sub>2</sub> Cathode with an Ionic Conductive LiVO<sub>3</sub> Coating Layer

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    With the aim to enhance the Li<sup>+</sup> ion conductivity, an ionic conductor, LiVO<sub>3</sub>, has been successfully coated on the surface of lithium-rich layered Li<sub>1.2</sub>Mn<sub>0.54</sub>Ni<sub>0.13</sub>Co<sub>0.13</sub>O<sub>2</sub> cathode materials for the first time. After combining with LiVO<sub>3</sub>, significantly improved high-rate capability and cyclic stability of the Li-rich cathode have been achieved due to the enhanced lithium ion diffusion and stabilized electrode/electrolyte interface. Moreover, a stable three-dimensional spinel phase has been generated in the surface region during the coating process, which mitigates the structure deterioration and suppresses the voltage decay and energy density degradation. After optimization, 5 wt % LiVO<sub>3</sub>-coated–Li<sub>1.2</sub>Mn<sub>0.54</sub>Ni<sub>0.13</sub>Co<sub>0.13</sub>O<sub>2</sub> exhibits superior electrochemical performance with a higher reversible capacity of 272 mA h g<sup>–1</sup>, increased initial Coulombic efficiency of 92.6%, and an excellent high-rate capability of 135 mA h g<sup>–1</sup> at 5 C, respectively. The coexistence of an ionic conductor coating layer and the locally transformed spinel structure generated in a one-step approach provides a novel design concept for surface modification on Li-rich Mn-based cathode materials toward high-performance lithium-ion batteries

    Developing a Reference Material for Diffusion-Controlled Formaldehyde Emissions Testing

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    Formaldehyde, a known human carcinogen and mucous membrane irritant, is emitted from a variety of building materials and indoor furnishings. The drive to improve building energy efficiency by decreasing ventilation rates increases the need to better understand emissions from indoor products and to identify and develop lower emitting materials. To help meet this need, formaldehyde emissions from indoor materials are typically measured using environmental chambers. However, chamber testing results are frequently inconsistent and provide little insight into the mechanisms governing emissions. This research addresses these problems by (1) developing a reference formaldehyde emissions source that can be used to validate chamber testing methods for characterization of dynamic sources of formaldehyde emissions and (2) demonstrating that emissions from finite formaldehyde sources can be predicted using a fundamental mass-transfer model. Formaldehyde mass-transfer mechanisms are elucidated, providing practical approaches for developing diffusion-controlled reference materials that mimic actual sources. The fundamental understanding of emissions mechanisms can be used to improve emissions testing and guide future risk reduction actions

    The results of the sensitivity analysis for different datasets (odds ratios <sup>a</sup>).

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    <p><sup>a</sup>Same factors as in the main study were adjusted in the logistic regression analyses.</p><p><sup>b</sup>(n = 8331) whole population excluded participants who had missing stress data (from work or home) or data for one of the main demographic variables (age or gender).</p><p><sup>c</sup>(n = 7160) whole population excluded participants who had missing stress data (from work or home) or data for one of the main demographic variables (age or gender), or who had taken antihypertension/lipid-lowering agents regularly.</p><p>The results of the sensitivity analysis for different datasets (odds ratios <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0129163#t004fn001" target="_blank"><sup>a</sup></a>).</p
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