Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 108
Filtrar
1.
Sci Total Environ ; 804: 149904, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34508929

RESUMO

Pteris cretica var. nervosa is a dominant fern species found in antimony (Sb) mining areas, capable of forming symbiosis with arbuscular mycorrhizal fungi (AMF), especially with those members of the Glomus genus. Despite this fern's relevance and the potential contribution of mycorrhizal symbiosis to phytoremediation, the AMF's impact on P. var. nervosa phytoremediation of Sb remains unknown. Here, we exposed P. var. nervosa to different concentrations of Sb for 6 months. Our results showed that Sb reduced shoot biomass, enlarged the root/shoot ratio, and disrupted the fronds' intracellular structure. AMF inoculation, however, was able to moderate these phenotypic changes and increased the accumulation level of Sb in plants. From a proteomics analysis of this plant's fronds, a total of 283 proteins were identified. Notably, those proteins with catalytic function, carbon fixing and ATP metabolic function were highly enriched. K-means clustering demonstrated protein-changing patterns involved in multiple metabolic pathways during exposure to Sb. Further, these patterns can be moderated by AMF inoculation. Pearson correlations were used to assess the plant biomarkers-soil Sb relationships; This revealed a strong correlation between ribosome alteration and the root/shoot ratio when inoculated with AMF, and a positive correlation between photosynthesis proteins and chlorophyll (SPAD value). Our results indicate AMF could moderate the fronds impairment by maintaining the sufficient protein levels for ribosomal functioning, photosynthesis activity and to counter ROS production. We demonstrate the effective use of AMF associated with P. cretica var. nervosa for Sb phytoremediation and the potential of applying proteomics to better understand the mechanism behind this symbiotic plant physiological response.

2.
Mater Sci Eng C Mater Biol Appl ; 128: 112354, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474902

RESUMO

In this paper, silk fibroin (SF) porous microcarriers containing strontium were constructed as injectable bone tissue engineering vehicles. The effects of SF concentration and strontium content on micromorphology, element distribution, strontium ion release and cellular behavior of the constructed microcarriers were investigated. The microcarriers with an open interconnected pore can be fabricated by controlling the concentration of SF. The strontium functionalized SF microcarriers showed the sustained release of strontium ion and allowed bone mesenchymal stem cells (BMSCs) to attach, proliferate and secrete extracellular matrix. Furthermore, the strontium functionalized SF microcarriers improved the osteogenic capability of BMSCs in vitro compared with those microcarriers without sustained release of strontium ion. This study presents a valuable approach to fabricate polymeric microcarriers with the capability of sustained release of strontium ion that show potential in bone tissue engineering applications.


Assuntos
Fibroínas , Diferenciação Celular , Osteogênese , Porosidade , Estrôncio , Engenharia Tecidual , Tecidos Suporte
3.
Int J Mol Sci ; 22(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34360962

RESUMO

Somatic cell nuclear transfer (SCNT) technology can reprogram terminally differentiated cell nuclei into a totipotent state. However, the underlying molecular barriers of SCNT embryo development remain incompletely elucidated. Here, we observed that transcription-related pathways were incompletely activated in nuclear transfer arrest (NTA) embryos compared to normal SCNT embryos and in vivo fertilized (WT) embryos, which hinders the development of SCNT embryos. We further revealed the transcription pathway associated gene regulatory networks (GRNs) and found the aberrant transcription pathways can lead to the massive dysregulation of genes in NTA embryos. The predicted target genes of transcription pathways contain a series of crucial factors in WT embryos, which play an important role in catabolic process, pluripotency regulation, epigenetic modification and signal transduction. In NTA embryos, however, these genes were varying degrees of inhibition and show a defect in synergy. Overall, our research found that the incomplete activation of transcription pathways is another potential molecular barrier for SCNT embryos besides the incomplete reprogramming of epigenetic modifications, broadening the understanding of molecular mechanism of SCNT embryonic development.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Técnicas de Transferência Nuclear/efeitos adversos , Transcriptoma , Animais , Blastocisto/metabolismo , Camundongos , RNA-Seq , Análise de Célula Única , Transcrição Genética
4.
J Environ Sci (China) ; 105: 150-162, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34130832

RESUMO

Eco-toxicity investigation of polymer materials was considered extremely necessary for their potential menace, which was widely use as mulching materials in agricultural. In this study, polyethylene (PE), polystyrene (PS) and synthetic biomaterials-Ecoflex and cellulose were applying into soil cultivated with two potential indicator plants species: oat (Avena sativa) and red radish (Raphanus sativum). Variety of chemical, biochemical parameters and enzyme activity in soil were proved as effective approach to evaluate polymers phytotoxicity in plant-soil mesocosm. The F-value of biomass, pH, heavy metal and electoral conductivity of Raphanus behaved significant different from T0. Significant analysis results indicated biodegradation was fast in PE than PS, besides, heavy metals were dramatically decrease in the end implied the plant absorption may help decrease heavy metal toxicity. The increase value at T2 of Dehydrogenase activity (0.84 higher than average value for Avena & 0.91 higher for Raphanus), Metabolic Index (3.12 higher than average value for Avena & 3.81 higher for Raphanus) means during soil enzyme activity was promoted by biodegradation for its heterotrophic organisms' energy transportation was stimulated. Statistics analysis was carried on Biplot PC1 (24.2% of the total variance), PC2 (23.2% of the total variance), versus PC3 (22.8% of the total variance), which indicated phosphatase activity and metabolic index was significant correlated, and high correlation of ammonium and protease activity. Furthermore, the effects were more evident in Raphanus treatments than in Avena, suggesting the higher sensitivity of Raphanus to polymers treatment, which indicate biodegradation of polymers in Raphanus treatment has produced intermediate phytotoxic compounds.


Assuntos
Raphanus , Poluentes do Solo , Biodegradação Ambiental , Polímeros/toxicidade , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
5.
Orphanet J Rare Dis ; 16(1): 242, 2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-34059112

RESUMO

BACKGROUND: Congenital cataract (CC) and congenital heart disease (CHD) are significant birth defects. In clinical practice, the concurrence of CC and CHD is frequently observed in patients. Additionally, some monogenic diseases, copy number variation (CNV) syndromes, and diseases associated with intrauterine infection involve both cataract and heart defects. However, little is known about the association between CC and CHD. Here, we characterised the demographic, clinical, and genetic features of patients with CC and heart defects. METHODS: Medical records for 334 hospitalised patients diagnosed with CC were reviewed. Demographic and clinical features of patients with CC with and without CHD were compared. Clinical and genomic information for patients with 'cataract' and 'cardiac defects' were reviewed from Database of Chromosomal Imbalance and Phenotype in Humans using Ensembl Resources (DECIPHER). Microarray-based comparative genomic hybridisation and whole-exome sequencing were performed in 10 trio families with CC and CHD to detect de novo genomic alterations, including copy number variants and single nucleotide changes. RESULTS: In a retrospective analysis of 334 patients with CC over the past 10 years at our hospital, we observed a high proportion of patients (41.13%) with CHD (including innocent CHD, which reported as left-to-right shunt in echocardiography test). The CC with CHD group had higher incidences of preterm birth and Down's syndrome than the CC without CHD group. Atrial septal defect was the most frequent heart defect. A total of 44 cases with cataracts and heart diseases were retrieved from Database of Chromosomal Imbalance and Phenotype in Humans using Ensembl Resources (DECIPHER). In total, 52 genomic alterations were reported, 44% of which were de novo germline variants. In the 10 trio families with CC and CHD, we found de novo CNVs responsible for two well-known chromosomal disorders and identified a novel pathogenic mutation in GJA8 responsible for CC. CONCLUSIONS: We observed significant associations between CHD and CC in our 10-year patient cohort. Based on the cohort and data from DECIPHER, developmental syndromes in some patients were due to genetic defects, thus explaining the concurrence of CC and CHD. Additionally, we detected de novo mutations as an independent cause of cataracts. Our findings suggest that developmental syndromes in patients with CC deserve more attention in clinical practice by ophthalmologists.


Assuntos
Catarata , Cardiopatias Congênitas , Nascimento Prematuro , Catarata/genética , Variações do Número de Cópias de DNA/genética , Feminino , Cardiopatias Congênitas/genética , Humanos , Recém-Nascido , Gravidez , Estudos Retrospectivos
6.
J Colloid Interface Sci ; 599: 88-99, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33933800

RESUMO

Amphiphilic Janus particles are characterized by their anisotropic morphology and unique physical and chemical properties. In the present research, amphiphilic Janus particles were used as stabilizing agents to prepare a fluorine-containing polyacrylate composite emulsion. The influences of the structure and dosage of amphiphilic Janus SiO2 particles and the amount of fluorine-containing monomer hexafluorobutyl methacrylate on the stability of the composite emulsion were investigated. It was noticed that when the hydrophilic and hydrophobic groups of Janus SiO2 particles were polyacrylamide and polymethyl methacrylate, respectively, the stabilization of the polyacrylate emulsion with Janus SiO2 particles was achieved. When 0.3 wt% of polyacrylamide/polymethyl methacrylate amphiphilic Janus SiO2 particles and 8 wt% of hexafluorobutyl methacrylate were used, a stable composite emulsion was obtained. The conversion rate reached 98.7% with an average particle size of 500 nm. The composite emulsion was applied for fabric finishing. The water contact angle of the fabric increased from 21.4° to 140.2°, demonstrating its greatly improved hydrophobicity. Therefore, it could be inferred that the synergistic effect of amphiphilic Janus SiO2 nanoparticles and hexafluorobutyl methacrylate improved the water resistance of the latex film.

7.
Biosens Bioelectron ; 185: 113265, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33930755

RESUMO

As a severe stage of cancers, peritoneal carcinomatosis should be frequently monitored by means of ascites analysis. Nevertheless, the analysis process is traumatic and time-consuming in clinical practice. In this study, an implantable platinum nanotree microelectrode with a wireless, battery-free and flexible electrochemical patch was developed for in vivo and real-time peritoneal glucose detection to monitor peritoneal carcinomatosis. As the core of implantable microelectrode, platinum trees were synthesized by one-step electrodeposition method and highly sensitive to glucose detection. The platinum nanotree microelectrode was implantable in peritoneal cavity in minimally invasive way. A flexible circuit patch could execute electrochemical test and realize wireless power harvesting and data interaction with a near field communication (NFC)-enabled smartphone. The whole system could detect glucose dynamics in vivo in rat peritoneal cavity. Furthermore, the accuracy of this system was validated in ascites of patients. In this way, the system could offer hassle-free, rapid and minimally invasive opportunities toward peritoneal carcinomatosis monitoring.


Assuntos
Técnicas Biossensoriais , Neoplasias Peritoneais , Animais , Fontes de Energia Elétrica , Humanos , Microeletrodos , Neoplasias Peritoneais/diagnóstico , Platina , Ratos
8.
Bull Entomol Res ; 111(4): 485-498, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33745467

RESUMO

The oriental armyworm, Mythimna separata (Walker) is a serious pest of agriculture that does particular damage to Gramineae crops in Asia, Europe, and Oceania. Metamorphosis is a key developmental stage in insects, although the genes underlying the metamorphic transition in M. separata remain largely unknown. Here, we sequenced the transcriptomes of five stages; mature larvae (ML), wandering (W), and pupation (1, 5, and 10 days after pupation, designated P1, P5, and P10) to identify transition-associated genes. Four libraries were generated, with 22,884, 23,534, 26,643, and 33,238 differentially expressed genes (DEGs) for the ML-vs-W, W-vs-P1, P1-vs-P5, and P5-vs-P10, respectively. Gene ontology enrichment analysis of DEGs showed that genes regulating the biosynthesis of the membrane and integral components of the membrane, which includes the cuticular protein (CP), 20-hydroxyecdysone (20E), and juvenile hormone (JH) biosynthesis, were enriched. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that DEGs were enriched in the metabolic pathways. Of these DEGs, thirty CP, seventeen 20E, and seven JH genes were differentially expressed across the developmental stages. For transcriptome validation, ten CP, 20E, and JH-related genes were selected and verified by real-time PCR quantitative. Collectively, our results provided a basis for further studies of the molecular mechanism of metamorphosis in M. separata.


Assuntos
Genes de Insetos , Metamorfose Biológica/genética , Mariposas/fisiologia , Transcriptoma , Animais , Ecdisterona/biossíntese , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Hormônios Juvenis/biossíntese , Larva/metabolismo , Pupa/metabolismo
9.
J Ovarian Res ; 14(1): 42, 2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750444

RESUMO

BACKGROUND: Previous meta-analysis studies suggested that pegylated liposomal doxorubicin (PLD) may improve the survival rate of patients with recurrent ovarian cancer. The aim of the present meta-analysis, then, was to further update the role of PLD in the treatment of recurrent ovarian cancer. METHODS: We performed a literature search using the electronic databases Medicine, EMBASE, Web of Science, and the Cochrane Library to 27 July 2020. We only restricted the randomized clinical trials. Study-specific hazard ratios and 95% confidence interval (HR/95% CI) and risk ratios and 95% confidence interval (RR/95% CI) were pooled using a random-effects model. RESULTS: Ten studies (12 trials) were included after screening 940 articles. We categorized the eligible studies into two groups: the doublet regimens (four trials, 1767 patients) showed that PLD plus carbo provided superior progression-free survival (PFS) (HR, 0.85; 95% CI, 0.74-0.97) and similar overall survival (OS) (HR, 1.00; 95% CI, 0.88-1.14) compared to paclitaxel (PAC) plus carboplatin (carbo). PLD plus carbo was associated with significantly more anemia and thrombocytopenia, and other side effects were well tolerated. The monotherapy regimens (eight trials, 1980 patients) showed that PLD possessed a similar PFS (HR, 1.02; 95% CI, 0.90-1.16) and OS (HR, 0.88; 95% CI, 0.77-1.01) relative to other monotherapies. PLD alone was also more associated with mucositis/stomatitis and hand-foot syndrome, while other side effects were well tolerated. CONCLUSIONS: In platinum-sensitive recurrent ovarian cancer, PLD plus carbo was more effective than PAC plus carbo, while in platinum-resistant or -refractory recurrent ovarian cancer, PLD exhibited similar survival to other monotherapies. Regarding side effects, PLD plus carbo and mono chemotherapy were both well tolerated.

10.
ACS Nano ; 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33570380

RESUMO

Plasmonic Bi2WO6 with strong localized surface plasmon resonance (LSPR) around the 500-1400 region is successfully constructed by electron doping. Oxygen vacancies on W-O-W (V1) and Bi-O-Bi (V2) sites are precisely controlled to obtain Bi2WO6-V1 with LSPR and Bi2WO6-V2 with defect absorption. Density functional theory (DFT) calculation demonstrates that the V1-induced energy state facilitates photoelectron collection for a long lifetime, resulting in LSPR of Bi2WO6. Photoelectron trapping on V1 sites is demonstrated by a single-particle photoluminescence (PL) study, and 93% PL quenching efficiency is observed. With strong LSPR, plasmonic Bi2WO6-V1 exhibits highly selective methane generation with a rate of 9.95 µmol g-1 h-1 during the CO2 reduction reaction (CO2-RR), which is 26-fold higher than 0.37 µmol g-1 h-1 of BiWO3-V2 under UV-visible light irradiation. LSPR-dependent methane generation is confirmed by various photocatalytic results of plasmonic Bi2WO6 with tunable LSPR and different light excitations. Furthermore, the DFT-simulated pathway of CO2-RR and in situ Fourier transform infrared spectra on the surface of Bi2WO6 prove that V1 sites facilitate CH4 generation. Our work provides a strategy to obtain nonmetallic plasmonic materials by electron doping.

11.
Health Psychol Rev ; 15(1): 140-158, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31847702

RESUMO

Self-efficacy is an important determinant of health behaviour. Digital interventions are a potentially acceptable and cost-effective way of delivering programmes of health behaviour change at scale. Whether behaviour change interventions work to increase self-efficacy in this context is unknown. This systematic review and meta-analysis sought to identify whether automated digital interventions are associated with positive changes in self-efficacy amongst non-clinical populations for five major health behaviours, and which BCTs are associated with that change. A systematic literature search identified 20 studies (n = 5624) that assessed changes in self-efficacy and were included in a random-effects meta-analysis. Interventions targeted: healthy eating (k = 4), physical activity (k = 9), sexual behaviour (k = 3) and smoking (k = 4). No interventions targeting alcohol use were identified. Overall, interventions had a small, positive effect on self-efficacy (g¯=0.190,CI[0.078;0.303]). The effect of interventions on self-efficacy did not differ as a function of health behaviour type (Q-between = 7.3704, p = .061, df = 3). Inclusion of the BCT 'information about social and environmental consequences' had a small, negative effect on self-efficacy (Δg¯=-0.297,Q=7.072,p=.008). Whilst this review indicates that digital interventions can be used to change self-efficacy, which techniques work best in this context is not clear.

12.
Front Chem ; 8: 779, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33088803

RESUMO

A series of molybdenum disulfide (MoS2)/Zn0.5Cd0.5S heterojunctions have been prepared via a mild one-pot hydrothermal method based on the optimization of composition content of primary photocatalyst. The photocatalysts demonstrated significantly improved visible light-driven photocatalytic activity toward H2 evolution from water without using any noble metal cocatalyst. Among the as-prepared composites, 0.2% MoS2/Zn0.5Cd0.5S shows the best performance. The highest H2 evolution rate reaches 21 mmol · g-1 · h-1, which is four times higher than that of pure Zn0.5Cd0.5S. The apparent quantum efficiency is about 46.3% at 425 nm. The superiority is attributed to the tight connection between MoS2 and Zn0.5Cd0.5S by this facile one-step hydrothermal synthesis. As a result, the formation of the heterostructure introduces built-in electric field at the interface that facilitates vectorial charge transfer. More specifically, photogenerated electrons transfer to MoS2 to conduct proton reduction, where the holes are retained on the surface of Zn0.5Cd0.5S to react with the sacrificial reagents. Moreover, the composite presents improved stability without notable activity decay after several cycled tests.

13.
Chem Commun (Camb) ; 56(88): 13603-13606, 2020 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-33057502

RESUMO

Adding particles of metal-organic frameworks (MOFs) into liquid electrolytes leads to semiliquid electrolytes, where nanoporous MOFs enclose anions while facilitating lithium-ion conduction. The improved transport efficiency of lithium-ions in semiliquid electrolytes boosts effective reaction kinetics, mitigates polarization, and produces affinitive electrolyte-electrode interfaces, which afford enhanced cycle durability for high-rate lithium batteries.

14.
Cell Death Dis ; 11(10): 834, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033239

RESUMO

Manganese (Mn) overexposure produces long-term cognitive deficits and reduces brain-derived neurotrophic factor (BDNF) in the hippocampus. However, it remains elusive whether Mn-dependent enhanced alpha-synuclein (α-Syn) expression, suggesting a multifaceted mode of neuronal toxicities, accounts for interference with BDNF/TrkB signaling. In this study, we used C57BL/6J WT and α-Syn knockout (KO) mice to establish a model of manganism and found that Mn-induced impairments in spatial memory and synaptic plasticity were related to the α-Syn protein. In addition, consistent with the long-term potentiation (LTP) impairments that were observed, α-Syn KO relieved Mn-induced degradation of PSD95, phosphorylated CaMKIIα, and downregulated SynGAP protein levels. We transfected HT22 cells with lentivirus (LV)-α-Syn shRNA, followed by BDNF and Mn stimulation. In vitro experiments indicated that α-Syn selectively interacted with TrkB receptors and inhibited BDNF/TrkB signaling, leading to phosphorylation and downregulation of GluN2B. The binding of α-Syn to TrkB and Fyn-mediated phosphorylation of GluN2B were negatively regulated by BDNF. Together, these findings indicate that Mn-dependent enhanced α-Syn expression contributes to further exacerbate BDNF protein-level reduction and to inhibit TrkB/Akt/Fyn signaling, thereby disturbing Fyn-mediated phosphorylation of the NMDA receptor GluN2B subunit at tyrosine. In KO α-Syn mice treated with Mn, spatial memory and LTP impairments were less pronounced than in WT mice. However, the same robust neuronal death was observed as a result of Mn-induced neurotoxicity.


Assuntos
Plasticidade Neuronal/fisiologia , Receptores de N-Metil-D-Aspartato/metabolismo , Memória Espacial/fisiologia , alfa-Sinucleína/metabolismo , Animais , Hipocampo/metabolismo , Potenciação de Longa Duração/fisiologia , Masculino , Manganês/metabolismo , Manganês/farmacologia , Camundongos Knockout , Neurônios/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia , alfa-Sinucleína/genética
15.
Nanotoxicology ; 14(10): 1381-1398, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33075238

RESUMO

Zinc ferrate nanoparticles (ZnFe2O4 NPs) have attracted enormous interest as potential nanomaterials. The purpose of this study was to examine the in vitro macrophages toxicity, in vivo safety, and immunogenicity. Three kinds of ZnFe2O4 NPs with different shapes (round, litchi, and raspberry), nano-sizes, and pores were successfully prepared. In vitro experiments showed that ZnFe2O4 NPs caused no cytotoxicity against the RAW 264.7 cells up to administered dose of 200 µg/mL, enhanced proinflammatory cytokine TNF-α, and costimulatory marker CD86 expression in the RAW 264.7 cells. Interestingly, ZnFe2O4 NPs reduced ROS expression, which was inconsistent with common metal oxide NPs such as iron oxide (Fe3O4) NPs and zinc oxide (ZnO) NPs. ZnFe2O4 NPs improved the RAW 264.7 cells phagocytosed more neutral red. There was no obvious difference in body weight, the number of immune cells, organ index, and expression of inflammatory factors in serum of rats administrated intravenously and subcutaneously on day 21 after treatment by ZnFe2O4 NPs in comparison with the blank control. These results demonstrated that ZnFe2O4 NPs slightly enhanced the function of the RAW 264.7 cells in vitro but caused no obvious toxicity to macrophages as well as rat blood cells, and low immunogenicity in rats, suggesting that ZnFe2O4 NPs as a biocompatible nanomaterials achieved potential for bioapplication in the future.


Assuntos
Macrófagos/efeitos dos fármacos , Nanopartículas/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Imunoglobulinas/sangue , Ferro/química , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/toxicidade , Especificidade de Órgãos , Fagocitose/efeitos dos fármacos , Células RAW 264.7 , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Propriedades de Superfície , Zinco/química
16.
Nat Commun ; 11(1): 5215, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33060606

RESUMO

The sluggish electrochemical kinetics of sulfur species has impeded the wide adoption of lithium-sulfur battery, which is one of the most promising candidates for next-generation energy storage system. Here, we present the electronic and geometric structures of all possible sulfur species and construct an electronic energy diagram to unveil their reaction pathways in batteries, as well as the molecular origin of their sluggish kinetics. By decoupling the contradictory requirements of accelerating charging and discharging processes, we select two pseudocapacitive oxides as electron-ion source and drain to enable the efficient transport of electron/Li+ to and from sulfur intermediates respectively. After incorporating dual oxides, the electrochemical kinetics of sulfur cathode is significantly accelerated. This strategy, which couples a fast-electrochemical reaction with a spontaneous chemical reaction to bypass a slow-electrochemical reaction pathway, offers a solution to accelerate an electrochemical reaction, providing new perspectives for the development of high-energy battery systems.

17.
Phys Chem Chem Phys ; 22(38): 21776-21783, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-32966363

RESUMO

Molybdenum disulfide (MoS2) is one of the two-dimensional layered semiconductor transition metal dichalcogenides (TMDCs) with great potential in electronics, optoelectronics, and spintronic devices. Sulfur vacancies in MoS2 are the most prevalent defects. However, the effect of sulfur vacancies on the electronic structure of MoS2 is still in dispute. Here we experimentally and theoretically investigated the effect of sulfur vacancies in MoS2. The vacancies were intentionally introduced by thermal annealing of MoS2 crystals in a vacuum environment. Angle-resolved photoemission spectroscopy (ARPES) was used directly to observe the electronic structure of the MoS2 single crystals. The experimental result distinctly revealed the appearance of an occupied defect state just above the valence band maximum (VBM) and an upward shift of the VBM after creating sulfur vacancies. In addition, density functional theory (DFT) calculations also confirmed the existence of the occupied defect state close to the VBM as well as two deep unoccupied states induced by the sulfur vacancies. Our results provide evidence to contradict that sulfur vacancies indicate the origin of n-type behaviour in MoS2. This work provides a rational strategy for tuning the electronic structures of MoS2.

18.
Behav Res Methods ; 52(6): 2657-2673, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32542441

RESUMO

In meta-analysis, heterogeneity often exists between studies. Knowledge about study features (i.e., moderators) that can explain the heterogeneity in effect sizes can be useful for researchers to assess the effectiveness of existing interventions and design new potentially effective interventions. When there are multiple moderators, they may amplify or attenuate each other's effect on treatment effectiveness. However, in most meta-analysis studies, interaction effects are neglected due to the lack of appropriate methods. The method meta-CART was recently proposed to identify interactions between multiple moderators. The analysis result is a tree model in which the studies are partitioned into more homogeneous subgroups by combinations of moderators. This paper describes the R-package metacart, which provides user-friendly functions to conduct meta-CART analyses in R. This package can fit both fixed- and random-effects meta-CART, and can handle dichotomous, categorical, ordinal and continuous moderators. In addition, a new look ahead procedure is presented. The application of the package is illustrated step-by-step using diverse examples.


Assuntos
Projetos de Pesquisa , Humanos , Resultado do Tratamento
19.
J Colloid Interface Sci ; 577: 48-53, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32464338

RESUMO

Porous carbon materials are promising candidates for anode materials in rechargeable potassium-ion batteries. However, their high surface area and low crystallinity usually cause side reactions with electrolytes and slanted charge/discharge profiles. Herein, we report the synthesis of porous carbon microspheres with highly graphitized structure and enhanced potassium-ion storage properties. The prepared carbon microspheres exhibit a low working potential of ~0.2 V, high Coulombic efficiency, and a stable reversible capacity of 292.0 mAh/g after 100 cycles, which is significantly higher than that of commercial graphite (137.5 mAh/g after 100 cycles). These desirable performances are attributed to the high crystallinity of carbon and its porous structure, which provide active sites for potassium-ion storage and alleviate the stress caused by the large volume change during the insertion and extraction of potassium ions.

20.
Rice (N Y) ; 13(1): 28, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32462553

RESUMO

BACKGROUND: Bacterial leaf streak (BLS) and bacterial blight (BB) are two major prevalent and devastating rice bacterial diseases caused by the Gram-negative bacteria of Xanthomonas oryzae pv. oryzicola (Xoc) and Xanthomonas oryzae pv. oryzae (Xoo), respectively. Previously, we identified a defence-related (DR) gene encoding a small heat shock protein, OsHsp18.0-CI, that positively regulates BLS and BB resistance in rice. RESULTS: To reveal the regulatory mechanism of the OsHsp18.0-CI response to Xoc and Xoo, we characterized the class B heat shock factor (Hsf), OsHsfB4d, through transcriptional analysis and a transgenic study. OsHsfB4d is upregulated post inoculation by either the Xoc strain RS105 or Xoo strain PXO99a in Zhonghua 11 (wild type, ZH11) as well as in OsHsp18.0-CI overexpressing rice plants. Transient expression of OsHsfB4d can activate the expression of green fluorescent protein (GFP) and luciferase (Luc) via the OsHsp18.0-CI promoter. Rice plants overexpressing OsHsfB4d exhibited enhanced resistance to RS105 and PXO99a as well as increased expression of OsHsp18.0-CI and pathogenesis-related genes. Furthermore, we found that OsHsfB4d directly binds to a DNA fragment carrying the only perfect heat shock element (HSE) in the promoter of OsHsp18.0-CI. CONCLUSION: Overall, we reveal that OsHsfB4d, a class B Hsf, acts as a positive regulator of OsHsp18.0-CI to mediate BLS and BB resistance in rice.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...