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1.
Proc Natl Acad Sci U S A ; 119(13): e2119883119, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35312369

RESUMO

SignificanceWe present a groundbreaking advance in completely nonprecious hydrogen fuel cell technologies achieving a record power density of 200 mW/cm2 with Ni@CNx anode and Co-Mn cathode. The 2-nm CNx coating weakens the O-binding energy, which effectively mitigates the undesirable surface oxidation during hydrogen oxidation reaction (HOR) polarization, leading to a stable fuel cell operation for Ni@CNx over 100 h at 200 mA/cm2, superior to a Ni nanoparticle counterpart. Ni@CNx exhibited a dramatically enhanced tolerance to CO relative to Pt/C, enabling the use of hydrogen gas with trace amounts of CO, critical for practical applications. The complete removal of precious metals in fuel cells lowers the catalyst cost to virtually negligible levels and marks a milestone for practical alkaline fuel cells.

2.
Hum Mol Genet ; 31(8): 1216-1229, 2022 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-34718573

RESUMO

The form of Charcot-Marie-Tooth type 4B (CMT4B) disease caused by mutations in myotubularin-related 5 (MTMR5; also called SET binding factor 1, SBF1) shows a spectrum of axonal and demyelinating nerve phenotypes. This contrasts with the CMT4B subtypes caused by MTMR2 or MTMR13 (SBF2) mutations, which are characterized by myelin outfoldings and classic demyelination. Thus, it is unclear whether MTMR5 plays an analogous or distinct role from that of its homolog, MTMR13, in the peripheral nervous system (PNS). MTMR5 and MTMR13 are pseudophosphatases predicted to regulate endosomal trafficking by activating Rab GTPases and binding to the phosphoinositide 3-phosphatase MTMR2. In the mouse PNS, Mtmr2 was required to maintain wild-type levels of Mtmr5 and Mtmr13, suggesting that these factors function in discrete protein complexes. Genetic elimination of both Mtmr5 and Mtmr13 in mice led to perinatal lethality, indicating that the two proteins have partially redundant functions during embryogenesis. Loss of Mtmr5 in mice did not cause CMT4B-like myelin outfoldings. However, adult Mtmr5-/- mouse nerves contained fewer myelinated axons than control nerves, likely as a result of axon radial sorting defects. Consistently, Mtmr5 levels were highest during axon radial sorting and fell sharply after postnatal day seven. Our findings suggest that Mtmr5 and Mtmr13 ensure proper axon radial sorting and Schwann cell myelination, respectively, perhaps through their direct interactions with Mtmr2. This study enhances our understanding of the non-redundant roles of the endosomal regulators MTMR5 and MTMR13 during normal peripheral nerve development and disease.


Assuntos
Doença de Charcot-Marie-Tooth , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Animais , Axônios/metabolismo , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/metabolismo , Camundongos , Bainha de Mielina/genética , Bainha de Mielina/metabolismo , Sistema Nervoso Periférico/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/genética , Células de Schwann/metabolismo
3.
Small ; 20(7): e2305873, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37803396

RESUMO

N-doped carbon (NC)-encapsulated transition metal (TM) nanocomposites are considered as alternatives to Pt-based hydrogen evolution reaction (HER) electrocatalysts; however, their poor electron transfer and mass diffusion capability at high current densities hinder their practical application. Herein, an oriented coupling strategy for the in situ grafting of ultrafine Co nanoparticle-embedded hollow porous C polyhedra onto Si nanowires (Co/NC-HP@Si-NWs) is proposed to address this concern. Experimental investigations reveal that the intimate coupling between the Si-NW and Co/NC nanocage forms a multithreaded conductive network, lowering the energy barrier for internal electron transfer. When functionalized as an HER electrocatalyst in 0.5 m H2 SO4 , Co/NC-HP@Si-NWs deliver overpotentials as low as 57 and 440 mV at 10 and 500 mA cm-2 , respectively, which are much better than those of the pristine Co/NC-HP. Moreover, Co/NC-HP@Si-NWs show an outstanding cycle durability of 24 h at 10 and 500 mA cm-2 . The findings of this study are expected to inspire revolutionary work on the development of Si-mediated TM-based electrocatalysts for the HER.

4.
Small ; 19(31): e2206723, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36592427

RESUMO

Metal-organic frameworks (MOFs) are regarded as one promising class of precatalysts for electrocatalytic oxygen evolution reaction (OER), yet most of them suffer from poor conductivity and lack of coordinatively unsaturated metal sites, which hinders the fast electrochemical reconstruction and thus a poor OER activity. To address this issue, a unique heterocomposite has been constructed by in situ inserting carbon dots (CDs) into cobalt-based zeolitic imidazolate framework (Co-ZIF) nanosheet arrays (Co-ZIF/CDs/CC) in the presence of carbon cloth (CC) via one-pot coprecipitation for alkaline OER. Benefiting from the synergism between CDs and Co-ZIF subunits such as superior conductivity, strong charge interaction as well as abundant metal sites exposure, the Co-ZIF/CDs/CC exhibits an enhanced promotion effect for OER and contributes to the deep phase transformation from CDs-coupled Co-ZIF to CDs-coupled active CoOOH. As expected, the achieved Co-ZIF/CDs/CC only requires an overpotential of 226 mV to deliver 10 mA cm-2 in 1.0 M KOH, which is lower than that of Co-ZIF/CC and superior to most previously reported CC-supported MOF precatalysts. Moreover, it can also maintain a large current density of 100 mA cm-2 for 24 h with negligible activity decay.

5.
Nanotechnology ; 34(37)2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37311447

RESUMO

The design and construction of three-dimensional covalent organic frameworks (3D COF) remains a major challenge, and it is necessary to explore new strategies to synthesize 3D COF with ideal structure. Here, we utilize two-dimensional covalent organic framework (2D COF) with allyl side chain to achieve interlayer crosslinking through olefin metathesis reaction, thereby constructing a 3D COF with cage-like structures. This new material named CAGE-COF has larger specific surface area and more open pore structure than the original 2D COF. The cathode material with CAGE-COF retained 78.7% of its initial capacity after 500 cycles, and the fading rate is 0.04% each cycle.


Assuntos
Lítio , Estruturas Metalorgânicas , Eletrodos , Alcenos , Fontes de Energia Elétrica , Enxofre
6.
Health Care Manag Sci ; 26(2): 330-343, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36749449

RESUMO

Cook et al. (Oper Res 61(3):666-676, 2013) propose a DEA-based model for the performance evaluation of non-homogeneous decision making units (DMUs) based on constant returns to scale (CRS), extended by Li et al. (Health Care Manag Sci 22(2):215-228, 2019) to variable returns to scale (VRS). This paper locates these models into more general DDF models to deal with nonhomogeneous DMUs and applies these to Hong Kong hospitals. The production process of each hospital is divided into subunits which have the same inputs and outputs and hospital performance is measured using the subunits. The paper provides CRS and VRS versions of DDF models and compares them with Cook et al. (Oper Res 61(3):666-676, 2013) and Li et al. (Health Care Manag Sci 22(2):215-228, 2019). A kernel-based method is used to estimate the distributions as well as a DEA-based efficiency analysis adapted by Simar and Zelenyuk to test the distributions. Both DDF CRS and VRS versions produce results similar to Cook et al. (Oper Res 61(3):666-676, 2013) and Li et al. (Health Care Manag Sci 22(2):215-228, 2019) respectively. However, the statistical tests find differences for the different technologies assumed as would be expected. For hospital managers, the more generalised DDF models expand their range of options in terms of directional improvements and priorities as well as dealing with non-homogeneity.


Assuntos
Eficiência Organizacional , Hospitais , Humanos , Hong Kong
7.
J Environ Manage ; 332: 117354, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36724597

RESUMO

As electric vehicles (EVs) are developing at a rapid pace, the foreseeable "scrap tide" of EV batteries poses a severe challenge to ecological protection. This article investigates a dual-recycle channel closed-loop supply chain and provides regulatory solutions to retired EV batteries' recycling. Specifically, we construct four supervision scenarios: S1 no policy intervention, S2 reward-penalty scheme, S3 deposit-refund scheme, and S4 dual scheme combining S2 and S3. Based on the Stackelberg game and empirical data, all scenarios' recycling performance is evaluated and compared with a view to "society, economy, and environment". The results revealed: (1) Compared with S1, the recycling rate and carbon reduction rate in S2∼S4 increase by 2.6049%/0.0092%, 4.0379%/0.0285%, and 6.6660%/0.0379%, respectively; (2) The difference between S2 and S3 in recycling performance depends on regulatory intensities, yet the latter places greater burdens on consumers and firms. The S4 presents optimal environmental performance but at the expense of socioeconomic development; (3) As regulatory intensity increases, social welfare rises driven by environmental benefits, then falls due to overburdened supply chain profits, consumer surplus, and policy expenditures; (4) Carbon trading prices and EVs' potential market sizes affect regulatory schemes' operations. Our results contribute to policy-making and managerial practices for EV battery recycling.


Assuntos
Formulação de Políticas , Reciclagem , Reciclagem/métodos , Fontes de Energia Elétrica , Eletricidade , Carbono
8.
Faraday Discuss ; 233(0): 100-111, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-34889928

RESUMO

As polyelectrolytes play a more and more important role in electrochemical fields, further understanding of the electrode-polyelectrolyte interface is in high demand. Surface-enhanced Raman spectroscopy (SERS) is utilized widely in electrode-solution interface research due to its ultra-high sensitivity, but is still rarely in the study of the electrode-polyelectrolyte interface due to difficulties in constructing appropriate electrochemical in situ devices. Additionally, the reported electrochemical in situ Raman works on the electrode-polyelectrolyte interface have a common problem of the coexistence of electrode-solution interfaces and electrode-polyelectrolyte interfaces. Here, we used screen printing electrodes (SPE) with a compact planar three-electrode structure to carry out a new electrochemical in situ SERS test method, which was suitable for the study of the electrode-polyelectrolyte interface. Polyelectrolyte membranes can be conveniently and closely coated on the SPE's planar three electrodes to achieve isolated electrode-polyelectrolyte interfaces without electrode-solution interfaces coexisting. Strongly potential-dependent signals were obtained from the Pt-Nafion™ interface directly across the Nafion™ membrane, which verifies that this method is practical for the electrochemical in situ SERS study of the electrode-polyelectrolyte interface.

9.
J Environ Manage ; 318: 115547, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35767921

RESUMO

Global warming and climate change are gaining traction in recent years. As a major cause of global warming, carbon emissions were centered to China's climate change policy initiatives. Nevertheless, the existing policy discourse has yet reached a consensus on the optimal modeling method for carbon emissions prediction that is well-informed of both policy goals and the time-series pattern of carbon emissions. This paper fills the gap by promoting a novel data-driven decision model for carbon emissions prediction that is based on the extended belief rule base (EBRB) inference model. The new decision model consists of three components: 1) an indicator integration method, which aims to generate a few group indicators from a large number of statistical indicators; 2) a new EBRB construction method, which aims to consider the management policy goals for constructing EBRB; 3) a new ER-based inference method, which aims to predict carbon emissions based on time series change of relevant factors. The effectiveness of the proposed decision model has been tested against carbon emissions management data from 30 provinces in China. Experimental results demonstrate that the model will offer powerful reference value in the policy decision-making process, which will help to meet policy requirements for carbon emissions.


Assuntos
Dióxido de Carbono , Carbono , Carbono/análise , Dióxido de Carbono/análise , China , Mudança Climática , Aquecimento Global
10.
Appl Soft Comput ; 124: 109055, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35637858

RESUMO

The Coronavirus Disease 2019 (COVID-19) has popularized since late December 2019. In present, it is still highly transmissible and has severe impact on the public health and global economy. Due to the lack of specific drug and the appearance of different variants, the selection of the antiviral therapy to treat the patients with mild symptom is of vital importance. Hence, in this paper, we propose a novel behavioral Three-Way Decision (3WD) model and apply it to the medicine selection decision. First, a new relative utility function is constructed by considering the risk-aversion behavior and regret-aversion behavior of human beings. Second, based on the relative utility function, some new rules are defined to calculate the thresholds and conditional probabilities in 3WD and some corresponding theorems are explored and proved. Next, a new information fusion mechanism in the framework of evidential reasoning algorithm is developed. Then, the decision results are obtained based on the Bayesian decision procedure and the principle of maximum utility. Finally, an example with large-scale data set and an example about medicine selection for COVID-19 are provided to show the implementation process and effectiveness of the proposed method. Comparative analysis and sensitivity analysis are also performed to illustrate the superiority and the robustness of the current proposal.

11.
Appl Intell (Dordr) ; 52(13): 15177-15192, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35308410

RESUMO

Heterogeneous multi-attribute case retrieval is a crucial step in generating emergency alternatives during the course of emergency decision making (EDM) by referring to historical cases. This paper develops a heterogeneous multi-attribute case retrieval method for EDM that considers five attribute formats: crisp numbers, interval numbers, intuitionistic fuzzy numbers, single-valued neutrosophic numbers (SvNNs), and interval-valued neutrosophic numbers (IvNNs). First, we propose a similarity measurement of IvNNs and calculate the attribute similarities for the five attribute formats. The attribute weights are established using an optimal model. Next, the case similarities are calculated and the set of the similar historical cases is constructed. Furthermore, the evaluated information based on heterogeneous multi-attribute from similar historical cases is provided, and the calculation method for the evaluation of utility based on TODIM (an acronym for interactive and multi-criteria decision-making in Portugese) is proposed. The most suitable historical case is determined based on the case similarity and the evaluated utility. From this, the emergency alternative is generated. Finally, we demonstrate the efficacy of the proposed method with a case study and conduct comparisons against the performance of existing methods to assess the validity and superiority of the proposed method.

12.
Biochem Biophys Res Commun ; 571: 152-158, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34325131

RESUMO

Potent neutralizing antibodies (Abs) have been proven with therapeutic efficacy for the intervention against SARS-CoV-2. Majority of these Abs function by directly interfering with the virus entry to host cells. Here, we identified a receptor binding domain (RBD) specific monoclonal Ab (mAb) 82A6 with efficient neutralizing potency against authentic SARS-CoV-2 virus. As most Abs targeting the non-receptor binding motif (RBM) region, 82A6 was incapable to block the RBD-ACE2 interaction. In particular, it actively promoted the S1 subunit shedding from the S protein, which may lead to effective reduction of intact SARS-CoV-2 viruses. Importantly, it could block potential syncytia formation associated with post-infectious cell surface expression of S proteins. Our study evidenced a RBD specific Ab with unique beneficial efficacy against SARS-CoV-2 infection, which might bring informative significance to understand the collective effects of neutralizing Abs elicited in COVID-19 patients.


Assuntos
Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , COVID-19/terapia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Monoclonais/uso terapêutico , Especificidade de Anticorpos , Sítios de Ligação/imunologia , COVID-19/imunologia , COVID-19/virologia , Células Gigantes/imunologia , Células Gigantes/virologia , Células HEK293 , Humanos , Imunização Passiva , Técnicas In Vitro , Domínios Proteicos , Subunidades Proteicas , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/antagonistas & inibidores , Glicoproteína da Espícula de Coronavírus/química , Eliminação de Partículas Virais , Soroterapia para COVID-19
13.
Bioorg Med Chem ; 30: 115940, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33340937

RESUMO

In the present work, a novel series of pyridinethiazole bearing benzylpiperidine hybrids were designed and synthesized as dual-target inhibitors of GSK-3ß/AChE. Among them, GD29 was the most promising candidate, with an IC50 value of 0.3 µM for hAChE and an IC50 value of 0.003 µM for hGSK-3ß, respectively. The compounds exhibited good drug-like properties with optimal inhibitory enzyme activities. Moreover, GD29 showed anti-inflammatory properties at micromolar concentrations and displayed interesting neuroprotective profiles in an in vitro model of oxidative stress-induced neuronal death. Notably, the compounds also exhibited good permeability across the blood-brain-barrier (BBB) both in vitro. Central cholinomimetic activity was confirmed using a scopolamine-induced cognition impairment model in Institute of Cancer Research (ICR) mice upon oral administration. The current work identified optimized compounds and explored the therapeutic potential of glycogen synthase kinase 3/cholinesterase inhibition for the treatment of AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/farmacologia , Fármacos Neuroprotetores/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Tiazóis/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/metabolismo , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Relação Dose-Resposta a Droga , Descoberta de Drogas , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Estrutura Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Piridinas/síntese química , Piridinas/química , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/química , Células Tumorais Cultivadas
14.
Anal Bioanal Chem ; 413(28): 6951-6962, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34676432

RESUMO

Epithelial-mesenchymal transition (EMT) is implicated in the pathological processes of cancer metastasis and drug resistance. Anti-cancer drugs may also potentially lead to EMT, resulting in their reduced therapeutic effect. Therefore, the combination of these anti-cancer drugs with anti-EMT agents has been promoted in clinic. Screening anti-EMT drugs and evaluation of EMT process are highly dependent on EMT biomarkers on cell membrane. At present, the detection of EMT biomarker is mainly by Western blot method, which is time-consuming and complicated. In this work, for effectively screening anti-EMT drugs by evaluation of the EMT process, a type of aptamer probe based on aggregation-induced emission (AIE) was designed. The aptamer SYL3C was employed to target the EMT biomarker EpCAM on cell membrane. Two fluorophores, FAM and tetraphenylethene (TPE, an AIE dye), were modified at the two ends of SYL3C, respectively. This aptamer probe (TPE-SYL3C-FAM) can monitor the EpCAM expression, which can be recovered by anti-EMT drugs. By observation of the change in TPE emission intensity, the anti-EMT effect of drugs can be evaluated. The FAM emission was used as internal reference to reduce environmental interferences. This probe can be potentially used to screen anti-EMT agents as anti-cancer adjuvant drugs with high throughput.


Assuntos
Antineoplásicos/metabolismo , Aptâmeros de Nucleotídeos/metabolismo , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Antineoplásicos/farmacologia , Biomarcadores/metabolismo , Linhagem Celular Tumoral , Corantes Fluorescentes/química , Humanos
15.
Bioorg Chem ; 115: 105241, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34426157

RESUMO

Cellular autophagy is an intracellular degradation pathway, which transports damaged, deformed, senescent or non-functional proteins and organelles to lysosome for digestion and degradation. Cellular autophagy is deeply evolutionarily conservedfromyeasttomammaliancells, and many homologous proteins of the autophahgy regulators are found in several species. This physiological process maintains the steady state of cells. Furtheremore, autophagy dysfunction is closely related to various diseases, such as neurodegenerative diseases, inflammation-related diseases, cardiovascular diseases, metabolic diseases, etc. The LC3 and p62 protein protein interaction (PPI) promotes the formation of autophagosomes and delivers polyubiquitinated "cargoes" to autophagic degradation. Therefore, LC3-p62 PPI plays an integral role in the formation of autophagosomes and effectively inhibits autophagy. However, there are still few studies on the LC3-p62 PPI inhibitors for its unclear molecular mechanism. Furthermore, most of these inhibitors are macromolecules with poorly active, and small molecules are particularly scarce. In this article, the computation method was used to identify the hot spot and design peptides as the binder of LC3-p62 PPI. Findings from this work provide a reference for the follow-up research of discovering small molecule inhibitors targeting LC3-p62 PPI.


Assuntos
Desenho de Fármacos , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Peptídeos/farmacologia , Proteínas de Ligação a RNA/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/metabolismo , Modelos Moleculares , Estrutura Molecular , Peptídeos/síntese química , Peptídeos/química , Ligação Proteica , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo , Relação Estrutura-Atividade
16.
Int J Health Plann Manage ; 36(6): 2199-2214, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34288109

RESUMO

Case weights capture the resource cost by diagnosis-related group (DRG) but may not fully reflect the complexity of the clinical services provided. This study describes the use of a work complexity index (WCI), for assessing acute care services focusing on those provided by physicians in healthcare systems. The services are classified using relative value units (RVUs) and their point value assigned using the resource-based relative value scale. 57,559 acute inpatients from a tertiary hospital were first classified into diagnosis-related groups, which together with the relative value units assigned to services were then used to calculate a work complexity index for 38 departments. A case mix index (CMI) was also compiled as a conventional measure of complexity which had a correlation of 0.676 (p < 0.001) with the WCI. The correlation between the WCI and the RVUs representing the weighted volume of physician activities was 0.342 (p = 0.036). The WCI represents a more output or activity focused measure of complexity whereas the CMI is more patient focused and thus provides better insights into Departments' productivity. Although this paper focuses on physicians, the WCI can be easily extended to include other clinical services.


Assuntos
Médicos , Escalas de Valor Relativo , Grupos Diagnósticos Relacionados , Humanos , Centros de Atenção Terciária
17.
Langmuir ; 36(33): 9658-9667, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32787068

RESUMO

C-doped ZnO particles have been successfully prepared by the calcination using microwave hydrothermally prepared metal-organic framework-5 (MOF-5) as the precursor. MOF-5 was turned into C-doped ZnO through calcination at 500 °C, and its cubic shape was well-maintained. X-ray photoelectron spectroscopic studies confirmed the C-doping in the ZnO. The as-prepared C-doped ZnO demonstrated a Rhodamine B (RhB) degradation efficiency of 98% in 2 h under an solar-simulated light irradiation, much higher than that of C-doped ZnO derived from MOF-5 synthesized by the ordinary hydrothermal method. The trapping experiment revealed that the crucial factors in the RhB removal were photogenerated h+ and •O2-.

18.
Langmuir ; 35(42): 13607-13613, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31554400

RESUMO

The self-healing feature of gallium (Ga) is unique, making Ga-based materials attract attention for their potential to solve the anode pulverization issue of lithium ion batteries. In this work, a hierarchical two-dimensional (2D) Ga2O3/C structure has been synthesized by a facile NaCl template method. Ga2O3 nanoparticles (3.8 nm) are uniformly embedded in 2D carbon nanosheets. The long horizontal length of the carbon nanosheets (10 µm) provides long-range electron conductivity, and the thin vertical thickness (75 nm) shortens the Li ion diffusion path. Benefited from the integrated 2D structure and the high electron conductivity, the obtained 2D Ga2O3/C nanosheets exhibit excellent overall performance, including high lithium storage capacity (1026 mAh g-1 at 0.5 A g-1), high rate capability (378 mAh g-1 at 10.0 A g-1), and high cyclability (500 cycles at 0.5 A g-1). The lithiation/delithiation mechanism of 2D Ga2O3/C has been further studied with combined electrochemical and ex situ X-ray diffraction methods.

19.
Angew Chem Int Ed Engl ; 58(5): 1442-1446, 2019 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-30548378

RESUMO

The Pt-catalyzed hydrogen oxidation reaction (HOR) for alkaline polymer electrolyte fuel cells (APEFCs) has been one of the focus subjects in current fuel-cell research. The Pt catalyst is inferior for HOR in alkaline solutions, and alloying with Ru is an effective promotion strategy. APEFCs with Pt-Ru anodes have provided a performance benchmark over 1 W cm-2 at 60 °C. The Pt anode is now found to be in fact as good as the Pt-Ru anode for APEFCs operated at elevated conditions. At 80 °C with appropriate gas back-pressure, the cell with a Pt anode exhibits a peak power density of about 1.9 W cm-2 , which is very close to that with a Pt-Ru anode. Even by decreasing the anode Pt loading to 0.1 mg cm-2 , over 1.5 W cm-2 can still be achieved at 80 °C. This finding alters the previous understanding about the Pt catalyzed HOR in alkaline media and casts a new light on the development of practical and high-power APFEC technology.

20.
Appl Environ Microbiol ; 84(17)2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29959241

RESUMO

Abscisic acid (ABA) is one of the five classical phytohormones involved in increasing the tolerance of plants for various kinds of stresses caused by abiotic or biotic factors, and it also plays important roles in regulating the activation of innate immune cells and glucose homeostasis in mammals. For these reasons, as a "stress hormone," ABA has recently received attention as a candidate drug for agriculture and biomedical applications, prompting significant development of ABA synthesis. Some plant-pathogenic fungi can synthesize natural ABA. The fungus Botrytis cinerea has been used for biotechnological production of ABA. Identification of the transcription factors (TFs) involved in regulation of ABA biosynthesis in B. cinerea would provide new clues to understand how ABA is synthesized and regulated. In this study, we defined a novel Cys2His2 TF, BcabaR1, that regulates the transcriptional levels of ABA synthase genes (bcaba1, bcaba2, bcaba3, and bcaba4) in an ABA-overproducing mutant, B. cinerea TBC-A. Electrophoretic mobility shift assays revealed that recombinant BcabaR1 can bind specifically to both a 14-nucleotide sequence motif and a 39-nucleotide sequence motif in the promoter region of bcaba1 to -4 genes in vitro A decreased transcriptional level of the bcabaR1 gene in B. cinerea led to significantly decreased ABA production and downregulated transcription of bcaba1 to -4 When bcabaR1 was overexpressed in B. cinerea, ABA production was significantly increased, with upregulated transcription of bcaba1 to -4 Thus, in this study, we found that BcabaR1 acts as a positive regulator of ABA biosynthesis in B. cinereaIMPORTANCE Abscisic acid (ABA) could make a potentially important contribution to theoretical research and applications in agriculture and medicine. Botrytis cinerea is a plant-pathogenic fungus that was found to produce ABA. There has been a view that ABA is related to the interaction between pathogenic fungi and plants. Identification of regulatory genes involved in ABA biosynthesis may facilitate an understanding of the underlying molecular mechanisms of ABA biosynthesis and the pathogenesis of B. cinerea Here, we present a positive regulator, BcabaR1, of ABA biosynthesis in B. cinerea that can affect the transcriptional level of the ABA biosynthesis gene cluster, bcaba1 to -4, by directly binding to the conserved sequence elements in the promoter of the bcaba1 to -4 genes. This TF was found to be specifically involved in regulation of ABA biosynthesis. This work provides new clues for finding other ABA biosynthesis genes and improving ABA yield in B. cinerea.


Assuntos
Ácido Abscísico/biossíntese , Botrytis/genética , Botrytis/metabolismo , Reguladores de Crescimento de Plantas/biossíntese , Fatores de Transcrição/metabolismo , Família Multigênica/genética , Doenças das Plantas/microbiologia , Fatores de Transcrição/genética , Transcrição Gênica/genética , Dedos de Zinco/genética
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