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1.
Artigo em Inglês | MEDLINE | ID: mdl-33807910

RESUMO

Gross motor locomotion is the basis of various sensory motor locomotion. Interventions helping preschoolers develop gross motor skills (GMS) could provide a solid foundation for complex motor skills. This study analyzed a table tennis physical activity program's influence on preschoolers' GMS development with 104 preschoolers (experimental group (EG): N = 52, 25 boys, 27 girls; control group (CG): N = 52, 25 boys, 27 girls). The EG conducted table tennis physical activities three times per week for 12 weeks. Preschoolers' GMSs were assessed using the Test of Gross Motor Development (second edition). After 12 weeks, both the male and female EGs had significantly improved scores for GMS, locomotor subtest, gallop, hop, leap, slide, object control subtest, strike a stationary ball, stationary dribble, catch, overarm throw, and underhand roll (p < 0.05, p < 0.01, p < 0.001). The female EG also showed significant improvement for the run, horizontal jump, and catch in the post-test. Both the male and female EGs significantly outperformed the control group in their post-test scores for GMS, locomotor subtest, object control subtest, strike a stationary ball, overarm throw, and underhand roll (p < 0.05). The female EG also showed significant differences in slide scores (p < 0.05). Therefore, table tennis physical activities can promote preschoolers' GMS development, especially object control skills. The research results provide an empirical basis for preschoolers' physical education. Meanwhile, our findings have important implications for preschoolers' GMS development and table tennis' popularization in Chinese kindergartens.

2.
Int J Nurs Stud ; 118: 103926, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33813085

RESUMO

BACKGROUND: There is a wide variety of preventive methods currently available for the treatment of exposure keratopathy. Because of a lack of evidence from head-to-head randomized controlled trials (RCTs), the relative effects of these preventive methods in exposure keratopathy patients remain unclear. The purpose of our study is to carry out a network meta-analysis comparing the efficacy of different methods for the prevention of exposure keratopathy and rank these nursing methods for practical consideration. METHODS: A literature search was performed of the MEDLINE (PubMed), EMBASE, Web of Science, China National Knowledge Infrastructure Library (CNKI), China Science and Technology Journal Database (Weipu), WanFang Database and China Biology Medicine disc. Two authors independently extracted data from each included RCTs according to a predesigned Excel spreadsheet and assessed the methodological quality of included RCTs using the Cochrane risk of bias tool. Data was analyzed using the R (V.3.6.2) and the Stata (V.15.0). RESULTS: 21 RCTs involving 2022 patients and evaluating 11 preventive methods were included. Rankings based on posterior probabilities revealed that artificial tear ointment might be the best way to prevent exposure keratopathy (35%), polyethylene covers might be the second-best (31%), swimming goggles might be the third-best (21%), foam dressing might be the fourth-best (18%). CONCLUSIONS: This network meta-analysis indicated that artificial tear ointment, polyethylene covers, swimming goggles and foam dressing might be selected for the prevention of exposure keratopathy in intensive care unit patients, which is important in future research. Although evidence is scant, more attention should be paid to head-to-head comparisons of the most commonly used prevention methods in this field.

3.
Mikrochim Acta ; 188(5): 151, 2021 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-33813618

RESUMO

A glucose (Glu) sensor was designed by introducing synthetic cyclic peptides (CPs) as recognition receptors and Au nanoparticles assisted graphitic carbon nitride (AuNPs/g-C3N4) for electrochemiluminescence (ECL) enhancement. The synthetic CP receptor (cyclo-[-CNDNHCRDNDC-]) with natural active center of Glu binding protein can mimic the interactions between Glu and Glu binding protein to specifically capture Glu. The AuNPs were reduced on g-C3N4 and formed a new nanohybrid that can be applied as an ECL emitter. The AuNPs/g-C3N4 effectively ameliorated the ECL response of bare g-C3N4. The ECL enhancement mechanism was theoretically speculated through computer simulation. Glu quantification was conducted by recording ECL shifts induced by the binding of Glu to CPs. The linear detection range of the fabricated CPs-based ECL sensor was 1 to 100 mmol L-1, and the detection limit (LOD) was 0.57 nmol L-1 (S / N = 3). The CP-based ECL sensor also showed good specificity, repeatability, stability, and favorable recoveries in sample analysis. This work offer a promising analytical method for Glu assay in clinical diagnostics and bioprocess monitoring.

5.
Front Med ; 2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33660217

RESUMO

Synthetic lethal screening, which exploits the combination of mutations that result in cell death, is a promising method for identifying novel drug targets. This method provides a new avenue for targeting "undruggable" proteins, such as c-Myc. Here, we revisit current methods used to target c-Myc and discuss the important functional nodes related to c-Myc in non-oncogene addicted network, whose inhibition may cause a catastrophe for tumor cell destiny but not for normal cells. We further discuss strategies to identify these functional nodes in the context of synthetic lethality. We review the progress and shortcomings of this research field and look forward to opportunities offered by synthetic lethal screening to treat tumors potently.

6.
Signal Transduct Target Ther ; 6(1): 117, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33692331

RESUMO

The Myc proto-oncogene family consists of three members, C-MYC, MYCN, and MYCL, which encodes the transcription factor c-Myc (hereafter Myc), N-Myc, and L-Myc, respectively. Myc protein orchestrates diverse physiological processes, including cell proliferation, differentiation, survival, and apoptosis. Myc modulates about 15% of the global transcriptome, and its deregulation rewires the cellular signaling modules inside tumor cells, thereby acquiring selective advantages. The deregulation of Myc occurs in >70% of human cancers, and is related to poor prognosis; hence, hyperactivated Myc oncoprotein has been proposed as an ideal drug target for decades. Nevertheless, no specific drug is currently available to directly target Myc, mainly because of its "undruggable" properties: lack of enzymatic pocket for conventional small molecules to bind; inaccessibility for antibody due to the predominant nucleus localization of Myc. Although the topic of targeting Myc has actively been reviewed in the past decades, exciting new progresses in this field keep emerging. In this review, after a comprehensive summarization of valuable sources for potential druggable targets of Myc-driven cancer, we also peer into the promising future of utilizing macropinocytosis to deliver peptides like Omomyc or antibody agents to intracellular compartment for cancer treatment.

7.
Theranostics ; 11(10): 4957-4974, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33754038

RESUMO

Rationale: TCR-T cell therapy plays a critical role in the treatment of malignant cancers. However, it is unclear how TCR-T cells are affected by PD-L1 molecule in the tumor environment. We performed an in-depth evaluation on how differential expressions of tumor PD-L1 can affect the functionality of T cells. Methods: We used MART-1-specific TCR-T cells (TCR-TMART-1), stimulated with MART-127-35 peptide-loaded MEL-526 tumor cells, expressing different proportions of PD-L1, to perform cellular assays and high-throughput single-cell RNA sequencing. Results: Different clusters of activated or cytotoxic TCR-TMART-1 responded divergently when stimulated with tumor cells expressing different percentages of PD-L1 expression. Compared to control T cells, TCR-TMART-1 were more sensitive to exhaustion, and secreted not only pro-inflammatory cytokines but also anti-inflammatory cytokines with increasing proportions of PD-L1+ tumor cells. The gene profiles of chemokines were modified by increased expression of tumor PD-L1, which concurrently downregulated pro-inflammatory and anti-inflammatory transcription factors. Furthermore, increased expression of tumor PD-L1 showed distinct effects on different inhibitory checkpoint molecules (ICMs). In addition, there was a limited correlation between the enrichment of cell death signaling in tumor cells and T cells and increased tumor PD-L1 expression. Conclusion: Overall, though the effector functionality of TCR-T cells was suppressed by increased expression percentages of tumor PD-L1 in vitro, scRNA-seq profiles revealed that both the anti-inflammatory and pro-inflammatory responses were triggered by a higher expression of tumor PD-L1. This suggests that the sole blockade of tumor PD-L1 might inhibit not only the anti-inflammatory response but also the pro-inflammatory response in the complicated tumor microenvironment. Thus, the outcome of PD-L1 intervention may depend on the final balance among the highly dynamic and heterogeneous immune regulatory circuits.

8.
Cancer Invest ; : 1-12, 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33646061

RESUMO

The switchable chimeric antigen receptors (CARs) have shown many advantages in CAR T-cell therapy. However, human primary T-cells are required to evaluate antigen-specific adaptors by IFN-γ assay or FACS analysis, which limits the throughput of adaptor screening. A sensitive and robust CD16-CAR Jurkat NFAT-eGFP reporter system has been developed to assess the therapeutic efficacy of antibody-targeted CAR-T-cell by effectively evaluating the T-cell activation by various tumor cells and the impact of immune checkpoint inhibitor antibodies. This reporter system facilitates the screening of targeted antibodies in a high throughput manner for the development of improved T-cell immunotherapy.

9.
Cell Host Microbe ; 29(3): 448-462.e5, 2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33539764

RESUMO

Enterovirus uncoating receptors bind at the surface depression ("canyon") that encircles each capsid vertex causing the release of a host-derived lipid called "pocket factor" that is buried in a hydrophobic pocket formed by the major viral capsid protein, VP1. Coxsackievirus and adenovirus receptor (CAR) is a universal uncoating receptor of group B coxsackieviruses (CVB). Here, we present five high-resolution cryoEM structures of CVB representing different stages of virus infection. Structural comparisons show that the CAR penetrates deeper into the canyon than other uncoating receptors, leading to a cascade of events: collapse of the VP1 hydrophobic pocket, high-efficiency release of the pocket factor and viral uncoating and genome release under neutral pH, as compared with low pH. Furthermore, we identified a potent therapeutic antibody that can neutralize viral infection by interfering with virion-CAR interactions, destabilizing the capsid and inducing virion disruption. Together, these results define the structural basis of CVB cell entry and antibody neutralization.

10.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(2): 101-107, 2021 Feb 10.
Artigo em Chinês | MEDLINE | ID: mdl-33565058

RESUMO

OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) for the detection of fetal anomalies among pregnant women with advanced age. METHODS: CMA results of 562 cases, in addition with the outcome of pregnancy and neonatal follow-up were reviewed. RESULTS: Among the 562 amniotic fluid samples, 73 cases (12.99%) of fetal chromosomal abnormalities were detected, which included 21 cases (3.73%) of chromosomal aneuploidies and 52 cases (9.25%) of copy number variations (CNVs). The latters included 27 cases of pathological CNVs (4.80%), 4 cases of possible pathogenic CNVs (0.71%) and 42 cases of variants with unknown clinical significance (7.47%). Compared with those under 35, the detection rate of fetal chromosomal aneuploidies for women with advanced age was higher under the indications of voluntary test, abnormal ultrasonic structures, abnormal ultrasonic soft index and risks indicated by non-invasive prenatal testing (NIPT). No significant difference was found in the detection rate of CNVs between those ≥35 and <35 and between those with age factor only and with additional indications (P> 0.05). 552 cases (98.22%) of pregnant women have completed the followed up. Among 31 women with pathological and possible pathogenic fetal CNVs detected by CMA, 25 had terminated the pregnancy, 6 (19.35%) have delivered without obvious abnormality. 41 pregnant women with fetal CNVs of unknown clinical significance have completed the follow up, among whom 3 had terminated the pregnancy, 1 newborn was found with malformation after birth, which yielded an abnormal pregnancy rate of 9.76%. 480 pregnant women with negative CMA results have completed the follow up, among whom 5 (1.04%) had abnormal pregnancy or delivered a child with birth defect. CONCLUSION: There is a certain difference between the outcome of pregnancy predicted by CMA testing and the actual outcome. The pregnancies with fetal CNVs with unknown clinical significance detected by CMA have a high adverse rate, which should attract clinical attention. CMA testing should be recommended for pregnant women with advanced age regardless of whether they have other symptoms. CMA combined with other detection methods is the trend for prenatal diagnosis.


Assuntos
Aberrações Cromossômicas , Idade Materna , Análise de Sequência com Séries de Oligonucleotídeos , Diagnóstico Pré-Natal , Aneuploidia , Variações do Número de Cópias de DNA , Feminino , Humanos , Recém-Nascido , Gravidez
11.
Mol Med Rep ; 23(3): 1, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33398367

RESUMO

Endotoxin lipopolysaccharide (LPS) is one of the primary causes of myocardial injury. Propofol confers protective effects against LPS­induced myocardial damage; however, the biological functions and mechanisms underlying propofol are not completely understood. The present study aimed to investigate the effects of propofol on LPS­induced myocardial injury. Primary neonatal rat cardiomyocytes were treated with LPS to establish a myocardial injury model. LDH release in the culture media was measured using a LDH assay kit. The interactions between NLR family pyrin domain containing 3 (NLRP3), apoptosis­associated speck­like protein containing A CARD (ASC) and pro­caspase­1 were determined using a co­immunoprecipitation assay. Cell viability was measured using an MTT assay, and the levels of cell apoptosis were determined using flow cytometry, JC­1 staining (mitochondrial membrane potential) and caspase­3 activity assays. The mRNA expression levels of TNF­α, IL­6, IL­1ß and IL­18, and the protein expression levels of NLRP3, ASC, pro­caspase­1, caspase­1 p10, pro­IL­1ß, IL­1ß, pro­IL­18, IL­18, high mobility group box­1 (HMGB1) and peroxisome proliferator­activated receptor Î³ (PPARγ) were analyzed using reverse transcription­quantitative PCR and western blotting analyses, respectively. ELISAs were performed to measure the production of inflammatory mediators, including TNF­α, IL­6, IL­1ß and IL­18. The present results demonstrated that pretreatment with propofol significantly attenuated LPS­induced neonatal rat cardiomyocyte injury in a concentration­ and time­dependent manner. Propofol pretreatment also significantly inhibited LPS­induced cardiomyocyte inflammation and apoptosis. The results suggested that propofol pretreatment inactivated HMGB1­dependent NLRP3 inflammasome signaling, which involved PPARγ activation. Therefore, the results indicated that propofol reduced endotoxin­induced cardiomyocyte injury by inhibiting inflammation and apoptosis via the PPARγ/HMGB1/NLRP3 axis, suggesting that propofol may serve as a potential therapeutic agent for septic myocardial damage.

12.
Nature ; 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33508854

RESUMO

Cell competition involves a conserved fitness-sensing process during which fitter cells eliminate neighbouring less-fit but viable cells1. Cell competition has been proposed as a surveillance mechanism to ensure normal development and tissue homeostasis, and has also been suggested to act as a barrier to interspecies chimerism2. However, cell competition has not been studied in an interspecies context during early development owing to the lack of an in vitro model. Here we developed an interspecies pluripotent stem cell (PSC) co-culture strategy and uncovered a previously unknown mode of cell competition between species. Interspecies competition between PSCs occurred in primed but not naive pluripotent cells, and between evolutionarily distant species. By comparative transcriptome analysis, we found that genes related to the NF-κB signalling pathway, among others, were upregulated in less-fit 'loser' human cells. Genetic inactivation of a core component (P65, also known as RELA) and an upstream regulator (MYD88) of the NF-κB complex in human cells could overcome the competition between human and mouse PSCs, thereby improving the survival and chimerism of human cells in early mouse embryos. These insights into cell competition pave the way for the study of evolutionarily conserved mechanisms that underlie competitive cell interactions during early mammalian development. Suppression of interspecies PSC competition may facilitate the generation of human tissues in animals.

13.
Mol Biol Rep ; 48(1): 975-981, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33394231

RESUMO

Calcium-sensing receptor (CaSR) is widely involved in the cell proliferation, differentiation, migration, adhesion and apoptosis, which can affect the vascular remodeling in the humanbody. The main ligand of CaSR is extracellular Ca2+. CaSR has the physiological significance in Ca2+ homeostasis. Pulmonary vascular remodeling is one of the main histopathological changes of pulmonary hypertension (PH). The abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs) results in the pulmonary vascular remodeling. CaSR is an important regulator of [Ca2+]i. [Ca2+]i is the main cause of the excessive pulmonary vascular remodeling in patients with PH. In this review, it was conclued that the structure of CaSR was prone to explore the devolopment or the treatment of PH. It was found that the regulation of CaSR with some miRNA could inhibit the proliferation of PASMCs, and that CaSR could affect the occurrence of autophagy in PH. Therefore, CaSR would become a new therapeutic target to PH.

14.
Phys Rev Lett ; 126(2): 023901, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33512207

RESUMO

We propose the mechanism of edge state-led mode coupling under topological protection; i.e., localized surface plasmons almost do not have any influence on the edge state, while the edge state greatly changes the local field distribution of surface plasmons. Based on this mechanism, in the well-designed topological photonic structure containing a resonant plasmon nanoantenna, an obvious absorption reduction in the spontaneous emission spectra appears due to the near-field deformation around the antenna induced by the edge state. Because a plasmon antenna with ultrasmall mode volume provides large Purcell enhancement and simultaneously the photonic crystal guides almost all scattering light into its edge state, the rate of nonscattering single photons reaches more than 10^{4}γ_{0}. This topological state-led mode coupling mechanism and induced absorption reduction, which are based on topological protection, will have a profound effect on the study of composite topological photonic structures and related micro- and nanoscale cavity quantum electrodynamics. Also, nonscattering large Purcell enhancement will provide practical use for on-chip quantum light sources, such as single-photon sources and nanolasers.

15.
J Virol ; 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33472937

RESUMO

Human papillomavirus type 58 (HPV58) is associated with cervical cancer and poses a significant health burden worldwide. Although the commercial 9-valent HPV vaccine covers HPV58, the structural and molecular-level neutralization sites of the HPV58 complete virion are not fully understood. Here, we report the high-resolution (∼3.5 Å) structure of the complete HPV58 pseudovirus (PsV58) using cryo-electron microscopy (cryo-EM). Three representative neutralizing monoclonal antibodies (nAbs 5G9, 2H3 and A4B4) were selected through clustering from a nAb panel against HPV58. Bypassing the steric hindrance and symmetry-mismatch in the HPV Fab-capsid immune-complex, we present three different neutralizing epitopes in the PsV58, and show that, despite differences in binding, these nAbs share a common neutralization mechanism. These results offer insight into HPV58 genotype specificity and broaden our understanding of HPV58 neutralization sites for antiviral research.IMPORTANCE Cervical cancer primarily results from persistent infection with high-risk types of human papillomavirus (HPV). HPV type 58 (HPV58) is an important causative agent, especially within Asia. Despite this, we still have limited data pertaining to the structural and neutralizing epitopes of HPV58, and this encumbers our in-depth understanding of the virus mode of infection. Here, we show that representative nAbs (5G9, 10B11, 2H3, 5H2 and A4B4) from three different groups share a common neutralization mechanism that appears to prohibit the virus from associating with the extracellular matrix and cell surface. Furthermore, we identify that the nAbs engage via three different binding patterns: top-center binding (5G9 and 10B11), top-fringe binding (2H3 and 5H2), and fringe binding (A4B4). Our work shows that, despite differences in the pattern in binding, nAbs against HPV58 share a common neutralization mechanism. These results provide new insight into the understanding of HPV58 infection.

16.
BMC Complement Med Ther ; 21(1): 16, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413274

RESUMO

BACKGROUND: Traditional Chinese medicine (TCM) has gained increasing acceptance and popularity by the global community. The current study aimed to investigate self-reported evaluations of learning TCM and opinions about TCM courses among undergraduate international students majoring in conventional medicine at a university in China. METHODS: A cross-sectional survey was conducted at the Zhejiang University School of Medicine. A self-reported questionnaire was administered to international undergraduates who were enrolled in the TCM course during the 2018 and 2019 academic years (n = 157). The course employed a student-centered, multiform learning model. Demographic data and self-reported evaluations of TCM learning background and TCM learning course were obtained to conduct the analysis. RESULTS: A total of 133 students responded to the questionnaire. Among the respondents, 21.0% had some TCM-related knowledge, and 51.1% were interested in learning TCM before the course. Ninety-six students (85.7%) were from Asia. Students from Thailand showed significantly more interest in learning TCM than did students from other Asian countries (p = 0.025). After the course, 77.2% of students agreed that the course had brought about many benefits, 86.4% were satisfied with the course content, and 77.3% were satisfied with the teaching method. Students expressed their willingness to further learn acupuncture and to obtain more skilled practice through more visualized learning methods. CONCLUSIONS: The majority of the international students we surveyed agreed that the TCM course improved their interest in and understanding of TCM. It is thus suggested that TCM education should be directed toward students' learning barriers and needs.

17.
Mol Cell Biochem ; 476(4): 1643-1650, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33417164

RESUMO

Zinc finger E-box binding homeobox 1 (ZEB1) is an important transcription factor in epithelial mesenchymal transition (EMT) which participates in the numerous life processes, such as embryonic development, fibrosis and tumor progression. ZEB1 has multiple functions in human body and plays a crucial part in some life processes. ZEB1 is vital for the formation and development of the organs in the embryonic period. The abnormal expression of ZEB1 is a predictor for the poor prognosis or the poor survival in several cancers. ZEB1 contributes to the occurrence of fibrosis, cancer and even chemoresistance. Some research is indicated that fibrosis is finally developed into the cancers. Therefore, ZEB1 is probably taken as a biomarker in fibrosis or cancer. In this review, it is predicted of the structure of ZEB1 and the protein binding sites of ZEB1 with some protein, and it is discussed about the roles of ZEB1 in fibrosis and cancer progression to elaborate the potential applications of ZEB1 in clinic.

18.
Immunity ; 54(2): 324-339.e8, 2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33453152

RESUMO

Vaccine elicitation of broadly neutralizing antibodies (bnAbs) is a key HIV-research goal. The VRC01 class of bnAbs targets the CD4-binding site on the HIV-envelope trimer and requires extensive somatic hypermutation (SHM) to neutralize effectively. Despite substantial progress, vaccine-induced VRC01-class antibodies starting from unmutated precursors have exhibited limited neutralization breadth, particularly against viruses bearing glycan on loop D residue N276 (glycan276), present on most circulating strains. Here, using sequential immunization of immunoglobulin (Ig)-humanized mice expressing diverse unmutated VRC01-class antibody precursors, we elicited serum responses capable of neutralizing viruses bearing glycan276 and isolated multiple lineages of VRC01-class bnAbs, including two with >50% breadth on a 208-strain panel. Crystal structures of representative bnAbs revealed the same mode of recognition as known VRC01-class bnAbs. Structure-function studies further pinpointed key mutations and correlated their induction with specific immunizations. VRC01-class bnAbs can thus be matured by sequential immunization from unmutated ancestors to >50% breadth, and we delineate immunogens and regimens inducing key SHM.

19.
Carbohydr Polym ; 252: 117022, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33183581

RESUMO

Cellulose is a ß-1,4 linked glucose polymer that is synthesized by higher plants, algae and even by some bacteria and animals, making it the most abundant polymer on earth. As the major load bearing structure of the plant cell wall, it is hugely important in terms of plant growth and development, and in recent years it has gained interest for its biotechnological applications. Naturally, there has been a large concerted research effort to uncover the regulatory mechanisms underpinning cellulose synthesis. During the last century, several major breakthroughs in our understanding of cellulose synthesis in algae, bacteria, and plants have been pivotal in advancing the field of cellulose research, improving the likelihood that cellulose synthesis could be feasibly adapted for sustainable purposes. In this review, we will summarize the major hypotheses and advancements made during the last century on the regulation of cellulose biosynthesis, focussing on Arabidopsis thaliana.

20.
Angew Chem Int Ed Engl ; 60(12): 6673-6681, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33331671

RESUMO

Herein, we present a new strategy for the synthesis of 2D porous MoP/Mo2 N heterojunction nanosheets based on the pyrolysis of 2D [PMo12 O40 ]3- -melamine (PMo12 -MA) nanosheet precursor from a polyethylene glycol (PEG)-mediated assembly route. The heterostructure nanosheets are ca. 20 nm thick and have plentiful pores (<5 nm). These structure features offer advantages to promote the HER activity, including the favorable water dissociation kinetics around heterojunction as confirmed by theoretical calculations, large accessible surface of 2D nanosheets, and enhanced mass-transport ability by pores. Consequently, the 2D porous MoP/Mo2 N heterojunction nanosheets exhibit excellent HER activity with low overpotentials of 89, 91 and 89 mV to achieve a current density of 10 mA cm-2 in alkaline, neutral and acidic electrolytes, respectively. The HER performance is superior to the commercial Pt/C at a current density >55 mA cm-2 in neutral medium and >190 mA cm-2 in alkaline medium.

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