200 research outputs found

    Layer-structured niobium oxides and their analogues for advanced hybrid capacitors

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    © 2019 Elsevier B.V. Niobium-based oxides including niobium oxide (Nb2O5) and their analogues with quasi-2D network of open and stable Wadsley-Roth shear crystal structure, have gained great interest for advanced hybrid supercapacitors due to their outstanding rate capability derived from the intercalation pseudocapacitive kinetics. To realize their full potential as battery-type anode electrodes for supercapacitor, various strategies have been effectively implemented to overcome the drawbacks especially the poor intrinsic electrical conductivity, including structure design, surface modification, conductivity enhancement, and electrode engineering. Here, we provide a comprehensive overview of the latest progress of Nb-based oxides for high-rate hybrid supercapacitors in the aspects of structure-performance relationship, performance-optimizing strategies, and energy storage mechanisms. We will also present our insights into the challenges and perspectives for future development and industrial applications

    EGTA, a calcium chelator, affects cell cycle and increases DNA methylation in root tips of Triticum aestivum L.

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    In this study, when germinated Triticum aestivum L. seeds were treated with 0, 2, 4 and 6 mM ethyl glycol tetraacetic acid (EGTA), root growth was suppressed and the mitotic index decreased. These inhibitory effects were positively correlated with EGTA concentration. RT-PCR analysis revealed that the expression of several gene markers related to the G1/S transition of the cell cycle were significantly downregulated. Confocal microscopy of Fluo-3/AM-stained roots showed chelation of nearly all of the Ca2+ within the root meristematic regions. Both random amplified polymorphic DNA (RAPD) and coupled restriction enzyme digestion-random amplification (CRED-RA) techniques showed significant increases in the levels of genomic DNA polymorphisms and degree of DNA methylation. The study provides information concerning the impact of Ca2+ chelator, EGTA, on the growth, expression of cell cycle transition marker genes, and changes in DNA structure and methylation in the wheat roots

    Atrial Fibrillation Beat Identification Using the Combination of Modified Frequency Slice Wavelet Transform and Convolution Neural Networks

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    Atrial fibrillation (AF) is a serious cardiovascular disease with the phenomenon of beating irregularly. It is the major cause of variety of heart diseases, such as myocardial infarction. Automatic AF beat detection is still a challenging task which needs further exploration. A new framework, which combines modified frequency slice wavelet transform (MFSWT) and convolutional neural networks (CNNs), was proposed for automatic AF beat identification. MFSWT was used to transform 1-s electrocardiogram (ECG) segments to time-frequency images, then the images were fed into a 12-layer CNN for feature extraction and AF/non-AF beat classification. The results on the MIT-BIH Atrial Fibrillation database showed that a mean accuracy (Acc) of 81.07% from 5-fold cross validation is achieved for the test data. The corresponding sensitivity (Se), specificity (Sp) and the area under ROC curve (AUC) results are 74.96%, 86.41% and 0.88. When excluding an extreme poor signal quality ECG recording in the test data, a mean Acc of 84.85% is achieved, with the corresponding Se, Sp and AUC values of 79.05%, 89.99% and 0.92. This study indicates that it is possible to accurately identify AF or non-AF ECGs from a short-term signal episode

    The association between GAD1 gene polymorphisms and cerebral palsy in Chinese infants

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    Studies suggest that GAD1 gene was a functional candidate susceptibility gene for cerebral palsy (CP). In order to investigate the contribution of GAD1 gene to the etiology of CP in Chinese infants, we carried out a case-control association study between GAD1 gene and CP. In this study, 374 health controls and 392 infants with CP were recruited. Genomic DNA was extracted from venous blood and all three single nucleotide polymorphisms in GAD1 (rs3791874, rs3791862 and rs16858977) were genotyped by Sequenom’s MassARRAY system. There were no significant differences in allele or genotype frequencies between CP or mixed CP patients and controls at any of the three genetic polymorphisms. Through haplotype analysis we found that haplotype GG (rs3791862, rs16858977) frequency demonstrated significantly statistical difference between mixed CP patients and controls (p= 0.0371). Our positive findings of haplotype GG suggested that variation of GAD1 gene was an important risk factor for mixed CP.Предполагается, что ген GAD1 является функциональным кандидатом на роль гена подверженности церебральному параличу (ЦП). Для исследования вклада гена GAD1 в этиологию ЦП у китайских детей методом случай – контроль проведено исследование ассоциации между наличием гена GAD1 и ЦП. В исследовании были задействованы 374 здоровых ребенка (контроль) и 392 ребенка с ЦП. Геномную ДНК выделяли из венозной крови, и все три единичных нуклеотидных полиморфизма гена GAD1 (rs3791874, rs3791862 и rs16858977) были генотипированы в системе Sequenom MassARRAY. Ни для одного из трех генетических полиморфизмов не обнаружено существенных различий в частотах аллелей или генотипов между больными ЦП или смешанными больными ЦП и контролем. Анализ гаплотипов показал существенные статистические различия в частоте гаплотипа GG (rs3791862, rs16858977) у смешанных больных ЦП и контрольной группы (p = 0.0371). Позитивный результат по гаплотипу GG свидетельствует о том, что вариация гена GAD1 является важным фактором риска для смешанного ЦП

    Mycoplasma hyorhinis infection in gastric carcinoma and its effects on the malignant phenotypes of gastric cancer cells

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    <p>Abstract</p> <p>Background</p> <p><it>Mycoplasma hyorhinis </it>infection has been postulated to play a role in the development of several types of cancer, but the direct evidence and mechanism remained to be determined.</p> <p>Methods</p> <p>Immunohistochemistry assay and nested polymerase-chain reaction (PCR) were performed to examine the <it>mycoplasma hyorhinis </it>infection in gastric cancer tissues. Statistical analysis was used to check the association between mycoplasma infection and clinicopathologic parameters. Transwell chamber assay and metastasis assay were used to evaluate <it>mycoplasma hyorhinis</it>' effects on metastasis in vitro and in vivo. <it>Mycoplasma hyorhinis</it>-induced extracellular signal-regulated kinase (ERK) and epidermal growth factor receptor (EGFR) activation were investigated by Western blot.</p> <p>Results</p> <p>My<it>coplasma hyorhinis </it>infection in gastric cancer tissues was revealed and statistical analysis indicated a significant association between mycoplasma infections and lymph node metastasis, Lauren's Classification, TNM stage, and age of the patients. <it>Mycoplasma hyorhinis </it>promoted tumor cell migration, invasion and metastasis <it>in vitro </it>and <it>in vivo</it>, which was possibly associated with the enhanced phosphorylation of EGFR and ERK1/2. The antibody against p37 protein of <it>Mycoplasma hyorhinis </it>could inhibit the migration of the infected cells.</p> <p>Conclusions</p> <p>The infection of <it>m</it>y<it>coplasma hyorhinis </it>may contribute to the development of gastric cancer and <it>Mycoplasma hyorhinis</it>-induced malignant phenotypes were possibly mediated by p37.</p

    Recent Progress in Perovskite Solar Cells Modified by Sulfur Compounds

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    In the past decade, organic–inorganic hybrid perovskite solar cells (PSCs) have begun to be increasingly studied worldwide owing to the superior properties of perovskite material. However, some issues have delayed their commercialization, such as their long-term stability, cost reduction, scale-up ability, and efficiency. The introduction of sulfur to PSCs can relieve the above issues because sulfur can passivate interfacial trap states, suppress charge recombination, and inhibit ion migration, thereby enhancing the stability of PSCs. Furthermore, Pb-S bonds provide new channels for carrier extraction. Herein, the sulfur-based compounds utilized in PSCs are summarized and classified according to their functions in the different layers of PSCs. The results indicate that these sulfur-based compounds have efficiently promoted the commercialization of PSCs. It is hoped that this review can help others understand the intrinsic phenomena of sulfur-based PSCs and motivate additional investigations

    Integrative analysis of transcriptome and miRNAome reveals molecular mechanisms regulating pericarp thickness in sweet corn during kernel development

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    Pericarp thickness affects the edible quality of sweet corn (Zea mays L. saccharata Sturt.). Therefore, breeding varieties with a thin pericarp is important for the quality breeding of sweet corn. However, the molecular mechanisms underlying the pericarp development remain largely unclear. We performed an integrative analysis of mRNA and miRNA sequencing to elucidate the genetic mechanism regulating pericarp thickness during kernel development (at 15 days, 19 days, and 23 days after pollination) of two sweet corn inbred lines with different pericarp thicknesses (M03, with a thinner pericarp and M08, with a thicker pericarp). A total of 2,443 and 1,409 differentially expressed genes (DEGs) were identified in M03 and M08, respectively. Our results indicate that phytohormone-mediated programmed cell death (PCD) may play a critical role in determining pericarp thickness in sweet corn. Auxin (AUX), gibberellin (GA), and brassinosteroid (BR) signal transduction may indirectly mediate PCD to regulate pericarp thickness in M03 (the thin pericarp variety). In contrast, abscisic acid (ABA), cytokinin (CK), and ethylene (ETH) signaling may be the key regulators of pericarp PCD in M08 (the thick pericarp variety). Furthermore, 110 differentially expressed microRNAs (DEMIs) and 478 differentially expressed target genes were identified. miRNA164-, miRNA167-, and miRNA156-mediated miRNA–mRNA pairs may participate in regulating pericarp thickness. The expression results of DEGs were validated by quantitative real-time PCR. These findings provide insights into the molecular mechanisms regulating pericarp thickness and propose the objective of breeding sweet corn varieties with a thin pericarp

    Observation of nonrelativistic plaid-like spin splitting in a noncoplanar antiferromagnet

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    Spatial, momentum and energy separation of electronic spins in condensed matter systems guides the development of novel devices where spin-polarized current is generated and manipulated. Recent attention on a set of previously overlooked symmetry operations in magnetic materials leads to the emergence of a new type of spin splitting besides the well-studied Zeeman, Rashba and Dresselhaus effects, enabling giant and momentum dependent spin polarization of energy bands on selected antiferromagnets independent of relativistic spin-orbit interaction. Despite the ever-growing theoretical predictions, the direct spectroscopic proof of such spin splitting is still lacking. Here, we provide solid spectroscopic and computational evidence for the existence of such materials. In the noncoplanar antiferromagnet MnTe2_2, the in-plane components of spin are found to be antisymmetric about the high-symmetry planes of the Brillouin zone, comprising a plaid-like spin texture in the antiferromagnetic ground state. Such an unconventional spin pattern, further found to diminish at the high-temperature paramagnetic state, stems from the intrinsic antiferromagnetic order instead of the relativistic spin-orbit coupling. Our finding demonstrates a new type of spin-momentum locking with a nonrelativistic origin, placing antiferromagnetic spintronics on a firm basis and paving the way for studying exotic quantum phenomena in related materials.Comment: Version 2, 30 pages, 4 main figures and 8 supporting figure
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