216 research outputs found
Layer-structured niobium oxides and their analogues for advanced hybrid capacitors
© 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
Vacancy-induced sodium-ion storage in N-doped carbon Nanofiber@MoS2nanosheet arrays
As a promising material for sodium-ion batteries, molybdenum disulphide (MoS2) affords excellent electrochemical performance owing to its large surface area and the accelerated electron transport within individual layers. However, it suffers from slow reaction kinetics and agglomeration owing to low conductivity and high surface energy. In this work, nitrogen-doped carbon nanofiber@MoS2nanosheets arrays with S-vacancies (NC@MoS2-VS) are developed via a process involving electrospining, hydrothermal and annealing. When served as an anode material for SIBs, this material displays a superior capacity of 495 mAh g−1over 100 charge/discharge cycles at a current density of 100 mA g−1, and the pseudocapacitive contribution is up to 74.4% as revealed by the cyclic voltammogram (CV) at 1 mV s−1. The theoretical calculations show that the presence of sulfur vacancies facilitates the adsorption of Na+and enhances the conductivity of MoS2. This work may pave a new avenue to develop other types of metal sulfides for high-performance SIBs
EGTA, a calcium chelator, affects cell cycle and increases DNA methylation in root tips of Triticum aestivum L.
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
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
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
<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
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
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
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A review and update on orphan drugs for the treatment of noninfectious uveitis
Introduction: Uveitis, a leading cause of preventable blindness around the world, is a critically underserved disease in regard to the medications approved for use. Multiple immunomodulatory therapy (IMT) drugs are appropriate for uveitis therapy but are still off-label. These IMT agents, including antimetabolites, calcineurin inhibitors, alkylating agents, and biologic agents, have been designated as “orphan drugs” and are widely used for systemic autoimmune diseases or organ transplantation. Area covered The purpose of this paper is to comprehensively review and summarize the approved orphan drugs and biologics that are being used to treat systemic diseases and to discuss drugs that have not yet received approval as an “orphan drug for treating uveitis” by the US Food and Drug Administration (FDA). Our perspective IMT, as a steroid-sparing agent for uveitis patients, has shown promising clinical results. Refractory and recurrent uveitis requires combination IMT agents. IMT is continued for a period of 2 years while the patient is in remission before considering tapering medication. Our current goals include developing further assessments regarding the efficacy, optimal dose, and safety in efforts to achieve FDA approval for “on-label” use of current IMT agents and biologics more quickly and to facilitate insurance coverage and expand access to the products for this orphan disease
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