22 research outputs found

    The Different Effects of Organic Amines on Synthetic Metal Phosphites/Phosphates

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    Four metal phosphites/phosphates crystal materials C8N4H34Al2P4O18 (1), C3N2H17GaP2O8 (2), H5In2P3O10 (3), and H9In2P3O13 (4) have been solvothermally synthesized by organic amines in the presence of mixed solvents. Structural analyses indicate that compound 1 and 2 show one-dimensional (1D) chain structures; compound 3 and 4 are three-dimensional (3D) inorganic open-framework indium phosphites. Organic amines show different mechanisms in the four compounds. The 2,2′-bipyridine organic amine acts as a template source and it breaks down small molecules, which enter into the structure of compound 1. For compound 2, 1,2-propanediamine has a role as protonated template and it forms a hydrogen bond with the inorganic skeleton structure. As for compound 3 and 4 without the organic template, the benzylamine and 2,2′-bipyridine mainly serve as structure-directing agent. Especially, compound 3 has an odd seven-ring channel, and compound 4 contains 3D intersecting six-ring, eight-ring, and 10-ring channels. X-ray diffraction (XRD), scanning electron microscopy (SEM), CHN, inductive coupled plasma (ICP), Infrared (IR), and thermal gravimetric (TG) analyze the four compounds

    Effect of Boron Addition on the Precipitation Behavior of S31254

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    To reduce the precipitation of σ phases and to improve the hot workability of S31254 steels, boron has been added into the composition of S31254 to a concentration of 40 ppm. The precipitation behavior was investigated before and after the addition of boron in different S31254 alloys during the compression deformation, and the nose temperature at 950 °C and the phase dissolution temperature at 1074 °C were selected as the measurement temperature. The result showed that more σ phases were precipitated at the grain boundary of S31254 alloys, compared to the boron-added alloy. Meanwhile, the addition of 40 ppm boron into the alloys has obviously prevented the σ phases from the austenitic matrix, and it takes longer time for the precipitation of σ phase at 950 °C. The specific influence factors of boron on the precipitation of σ phases were also further discussed

    LncRNA Expression Profile of Human Thoracic Aortic Dissection by High-Throughput Sequencing

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    Background/Aims: In this study, the long non-coding RNA (lncRNA) expression profile in human thoracic aortic dissection (TAD), a highly lethal cardiovascular disease, was investigated. Methods: Human TAD (n=3) and normal aortic tissues (NA) (n=3) were examined by high-throughput sequencing. Bioinformatics analyses were performed to predict the roles of aberrantly expressed lncRNAs. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to validate the results. Results: A total of 269 lncRNAs (159 up-regulated and 110 down-regulated) and 2, 255 mRNAs (1 294 up-regulated and 961 down-regulated) were aberrantly expressed in human TAD (fold-change> 1.5, P< 0.05). QRT-PCR results of five dysregulated genes were consistent with HTS data. A lncRNA-mRNA coexpression analysis showed positive correlations between the up-regulated lncRNA (ENSG00000269936) and its adjacent up-regulated mRNA (MAP2K6, R=0.940, P< 0.01), and between the down-regulated lncRNA_1421 and its down-regulated mRNAs (FBLN5, R=0.950, P< 0.01; ACTA2, R=0.96, P< 0.01; TIMP3, R=0.96, P< 0.05). The lncRNA-miRNA-mRNA network indicated that the up-regulated lncRNA XIST and p21 had similar sequences targeted by has-miR-17-5p. The results of luciferase assay and fluorescence immuno-cytochemistry were consistent with that. And qRT-PCR results showed that lncRNA XIST and p21 were expressed at a higher level and has-miR-17-5p was expressed at a lower level in TAD than in NA. The predicted binding motifs of three up-regulated lncRNAs (ENSG00000248508, ENSG00000226530, and EG00000259719) were correlated with up-regulated RUNX1 (R=0.982, P< 0.001; R=0.967, P< 0.01; R=0.960, P< 0.01, respectively). Conclusions: Our study revealed a set of dysregulated lncRNAs and predicted their multiple potential functions in human TAD. These findings suggest that lncRNAs are novel potential therapeutic targets for human TAD

    Vapor-fumigation for record efficiency two-dimensional perovskite solar cells with superior stability

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    Two-dimensional (2D) perovskites have emerged as prospective candidates for high performance perovskite solar cells (PSCs) due to their remarkable environmental stability. However, their power conversion efficiency (PCE) is much lower than that of their 3D counterparts owing to large exciton binding energy, poor carrier transport, and low conductivity. Herein, we developed a methylammonium (MA) based 2D perovskite thin film using vapor-fumigation technology. Compared to the traditional 2D perovskite based on bulky butylammonium (BA) cations, its exciton binding energy significantly decreased to 172 meV from 510 meV, as calculated by first-order perturbation theory and an infinite barrier approximation, due to the high dielectric constant of MA. According to the WKb approximation, the tunneling probability of a carrier through a quantum well increased by four orders of magnitude because of the smaller layer thickness, which was confirmed by XRD (the layer spacing decreased to 9.08 angstrom of MA(2)PbI(4) from 13.39 angstrom of BA(2)PbI(4)). In addition, theoretical calculations and experimental analysis reveal that the MA(2)PbI(4) perovskite possesses a narrow band gap, good conductivity, and a low trap density. As a result, the PCE of the 2D PSCs reached 16.92%, and the certified efficiency was 16.6% according to the National Institute of Metrology (NIM), the highest efficiency value so far for 2D PSCs. Furthermore, the MA(2)PbI(4) devices exhibited superior long-term stability under illumination and exposure to environmental conditions. The PCEs of the 2D perovskite devices without encapsulation degraded by only 2.2% from their initial values when exposed to ambient conditions at similar to 55% relative humidity for 1512 hours. Meanwhile, the efficiency remained 97.2% of its initial value when the device was continuously illuminated for 500 hours at 60 degrees C in argon. Even after following the illumination test with light-soaking for over 500 h in ambient air, the PCE of the unsealed device suffered only a minor degradation of 3.8%

    Nature of terrace edge states (TES) in lower-dimensional halide perovskite

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    Lower-dimensional quasi-two-dimensional (quasi-2D) halide perovskites have emerged as promising building blocks for multiple optoelectronic applications due to their superior photophysical properties. Recently, there has been a research focus on the terrace edge states (TES) in quasi-2D perovskites, which are thought to provide hypothetical highways to transport the excited states and thus give a new insight into boosting relevant device performance. Nevertheless, there is neither direct evidence of the electronic facets nor an in-depth understanding of these newly observed nontrivial TES. Here, we are the first to directly visualize the highly charged concentrated TES by means of a charge gradient microscopy (CGM) technique and elucidate the nature of TES through a combination of microscopic characterizations, including high-resolution transmission electron microscopy, Kelvin probe force microscopy and confocal fluorescence microscopy coupled with a first-principles density functional theory (DFT) calculation. It is shown that TES of quasi-2D perovskites are highly conductive (in distinct contrast to the insulating flat terrace region) and display a high Fermi-level and small forbidden bandwidth, which is attributed to the unique electron orbitals of the Pb atoms at the terrace edges. This distinctive conductivity of TES is of great importance in distinguishing them from bulk physical properties and inspiring novel nanoscale electronic applications, such as tip-based data storage and triboelectric nanogenerators

    Clinical relevance of different handgrip strength indexes and cardiovascular disease risk factors: A cross-sectional study in suburb-dwelling elderly Chinese

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    Background: Reduced muscle strength, as measured by handgrip strength (HS), has been associated with an increased risk of cardiovascular disease (CVD). The aim of this study was to examine the association between different HS indexes and CVD risk factors in elderly Chinese individuals. We also determine optimal cutoffs of HS indexes for predicting CVD risk factors. Methods: Data were obtained from 603 men and 789 women aged ≥60 years (average age 66.8 ± 6.4 y). These study participants were recruited in the suburb area of Tianjin, China. An individual was considered a patient when they exhibited any one of three CVD risk factors: diabetes mellitus, hypertension and dyslipidemia. All participants were interviewed face-to-face. In addition, serum samples were collected from all participants, and all participants underwent measures of anthropometry and HS. Results: The optimal cutoffs were 0.376 of HS/weight in men and 0.726 of HS/body fat mass in women for predicting diabetes mellitus. The adjusted odds ratios (ORs) of at least one CVD risk factor for those with low muscle strength identified by HS/body fat mass were 2.14 (95% confidence interval [CI]: 1.53, 3.44; p < 0.001) in men and 2.32 (95% CI: 1.60, 3.29; p < 0.001) in women. Conclusion: HS/body fat mass appear to be the index best associated with CVD risk factors except diabetes mellitus in men. The optimal cutoffs of HS indexes have the potential to identify elderly adults at risk of CVD. Keywords: CVD risk factor, Handgrip strength indexes, ROC analysi
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