Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nano Lett ; 16(9): 5365-72, 2016 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-27501313

RESUMO

The lithium-sulfur (Li-S) rechargeable battery has the benefit of high gravimetric energy density and low cost. Significant research currently focuses on increasing the sulfur loading and sulfur/inactive-materials ratio, to improve life and capacity. Inspired by nature's ant-nest structure, this research results in a novel Li-S electrode that is designed to meet both goals. With only three simple manufacturing-friendly steps, which include slurry ball-milling, doctor-blade-based laminate casting, and the use of the sacrificial method with water to dissolve away table salt, the ant-nest design has been successfully recreated in an Li-S electrode. The efficient capabilities of the ant-nest structure are adopted to facilitate fast ion transportation, sustain polysulfide dissolution, and assist efficient precipitation. High cycling stability in the Li-S batteries, for practical applications, has been achieved with up to 3 mg·cm(-2) sulfur loading. Li-S electrodes with up to a 85% sulfur ratio have also been achieved for the efficient design of this novel ant-nest structure.

2.
ACS Appl Mater Interfaces ; 15(35): 41697-41707, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37610099

RESUMO

Ultra-fine nanoparticles (uf-NPs) embedded in hierarchical porous carbon (HPC) have been proven to possess intriguing properties for various energy storage applications, but effective synthetic control is still lacking. Herein, we present an efficient coordination anchor activation (CAA) strategy for the scalable synthesis and elaborate control of a series of uf-NPs embedded in HPC (Sb@HPC and FeSb2@HPC as examples), which is achieved by taking advantage of the coordination capability of industrial ionic exchange resins. The in situ coordination-anchored uf-NPs and the tailored hierarchical porous HPC enables superior rate capability (533.1 mA h g-1 at 3.30 A g-1 for Sb@HPC, 276.0 mA h g-1 at 5.37 A g-1 for FeSb2@HPC), enhanced cycling stability, and high reversible areal capacity (5.02 mA h cm-2). Our study demonstrates a potentially scalable uf-NP synthesis strategy with industrial raw materials that can be applied to a large variety of energy materials.

3.
ACS Appl Mater Interfaces ; 15(31): 37381-37389, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37494659

RESUMO

The rational design of confined host to tutor Li nucleation and deposition behavior remains a key challenge for the long stability of lithium metal anodes (LMAs), while the scalability and feasibility of the method need to be taken into concern. Herein, a biomimic strategy is designed for tutoring in-depth nucleation and bottom-up Li deposition by composing ant-nest-like lithiophilic hosts for LMAs with light-weight flexible and conductive carbon nanotubes (CNTs) as the framework, table salt (sodium chloride, NaCl) as the washable porous creator, and homogeneously dispersed nano-Si as the nucleation site. It possesses similar optimized structure as ant nests in nature and can provide large and conductive inner volume for Li storage. Combining with the interconnected passways can ensure effective ion compensation like food transport channels for ants, and the well-designed host can take effect as an individual Li anode (5 mA h cm-2 area Li loading for demonstration) and the record-long stable LMA host can be achieved for over a 2200 h lifespan with minimum volume expansion. Therefore, this biomimic strategy is developed with all commercialized battery materials, and all industry compatible production methods can provide a feasible technical path for the stable, long-cyclability, and reliable host design for LMAs.

4.
ACS Appl Mater Interfaces ; 15(32): 38956-38964, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37527182

RESUMO

As the only commercialized negative current collector, copper (Cu) foil possesses insurmountable applicational advantages as a lithium metal anode (LMA) substrate. However, the successful usage of Cu foil is limited by the poor Li affinity and crystal face variation, which will lead to severe lithium dendrite growth and poor cyclability. Herein, an industrial-popular ion implantation technique is first adopted for Cu surface modification. With the high-energy implantations of N+ plasma, the unique N-rich transition interface can be formed, among which the lithiophilic CuxNy with extended crystal domains can have uniform Cu crystal faces and offer benefit for Li nucleation/deposition; besides, the induced Li3N-rich SEI with high ionic conductivity can support Li-ion transport kinetics, suppress Li dendrite growth, and mitigate the side reaction to improve LMA stability. Consequently, a uniform Li nucleation/deposition is achieved, with obviously enhanced cycling stability and rate capability for the full cells. This technological maturity ion implantation method can be readily extended to any non/metallic ion species, or joint implantation of bi/multiple ions, and other substrates, demonstrating a possible route to surmount the metal anode challenges.

5.
Nanoscale ; 14(13): 5033-5043, 2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-35289829

RESUMO

The interface regulation of lithium metal anodes (LMAs) is considered one of the most critical issues in the pursuit of high energy density for lithium metal batteries. As a key physical characteristic, the dielectric feature of the interface overlayer decides the electric field and charge-current distribution within the interface region and directly influences the Li deposition behavior of LMAs. Herein, a high-dielectric artificial solid-electrolyte interface (SEI) is designed to regulate the electric field distribution and Li+ flux and stabilize the interface in LMAs. In the hybrid organic-inorganic polydopamine (PDA)-SiO2 artificial SEI, the enhanced dielectric permittivity by inorganic SiO2 has important effects in preventing current variation, guiding uniform current/potential distribution and homogenizing the Li+ flux within the SEI interface, thus achieving uniform Li plating, while the high elasticity, strong Li affinity and lithiophilic/hydrophilic property of PDA can suppress Li dendrite growth and stabilize the SEI structure over long cycles. These multi-functional properties of the artificial SEI for LMAs can achieve remarkable cycling in both the symmetric cell configuration (2800 h at 5 mA cm-2 with 1 mA h cm-2) and LiCoO2||Li full cells. Our work provides a physical point-of-view of the novel configuration of the artificial SEI for stable LMAs and can be extended to the protection of other alkali metal anodes.

6.
Front Endocrinol (Lausanne) ; 11: 513073, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33391180

RESUMO

Objective: To analyze association between different perioperative glycemic control strategies and postoperative outcomes in patients with diabetes undergoing cardiac surgery. Methods: MEDLINE, Cochrane Library, Web of Science, EMBASE, Wanfang Data, China National Knowledge Infrastructure (CNKI) and China Biology Medicine (CBM) databases were searched from inception to January 31, 2019. Two researchers independently screened the literature, extracted data, and evaluated the risk of bias of included studies, and consensus was reached by discussion with a third researcher. Results: Six RCTs were included in the meta-analysis. We analyzed the effect of liberal (>180 mg/dl or 10.0 mmol/L), moderate (140-180 mg/dl or 7.8-10.0 mmol/L) and strict (<140 mg/dl or 7.8 mmol/L) glycemic control strategies in patients with diabetes undergoing cardiac surgery. The pooled results showed that strict glycemic control strategy was associated with a significant reduction in the risk of atrial fibrillation [OR = 0.48, 95%CI (0.32, 0.72), P < 0.001] and sternal wound infection [OR = 0.28, 95%CI (0.14, 0.54), P < 0.001], while there was no significant differences in postoperative mortality, stroke, and hypoglycemic episodes when compared with moderate control. In addition, there is no significant difference between moderate and liberal glycemic control strategies in postoperative mortality. However, moderate control was beneficial in reducing atrial fibrillation [OR = 0.28, 95%CI (0.13, 0.60), P = 0.001] compared with the liberal glycemic control strategy. Conclusions: This meta-analysis showed when compared with moderate glycemic control strategy in patients with diabetes undergoing cardiac surgery, maintained strict glycemic control was associated with lower risk of atrial fibrillation and sternal wound infection. No benefit was found with liberal glycemic control strategy, so it could be a poor glycemic control strategy.


Assuntos
Procedimentos Cirúrgicos Cardíacos/mortalidade , Diabetes Mellitus/mortalidade , Diabetes Mellitus/terapia , Controle Glicêmico/métodos , Humanos , Período Perioperatório , Complicações Pós-Operatórias/mortalidade , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
Sci Total Environ ; 707: 136176, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-31972914

RESUMO

The widespread use of pharmaceuticals and personal care products (PPCPs) has raised serious concerns regarding their potential ecotoxicological effects. We examined the photosynthetic toxicity of four non-steroidal anti-inflammatory drugs (NSAIDs), i.e. ibuprofen (rac-IBU and S-(+)-IBU), aspirin (ASA) and ketoprofen (KEP) on the green alga Scenedesmus obliquus. Our results showed that NSAIDs exerted inhibitory effects on algal growth; the IC50-24h of S-(+)-IBU, rac-IBU, ASA, and KEP was 123.29, 107.91, 103.05, and 4.03 mg/L, respectively. KEP was the most toxic, ASA was slightly more toxic than rac-IBU, and S-(+)-IBU was the least toxic. NSAIDs adversely affected the cellular ultrastructure, as evident from plasmolysis, chloroplast deformation and disintegration. NSAID treatments decreased the chlorophyll and carotenoid content, and chlorophyll fluorescence parameters such as minimum fluorescence yield (F0), maximum fluorescence yield (Fm), maximum photochemical quantum yield (Fv/Fm), PSII (photosystem II) effective quantum yield [Y(II)], photosynthetic electron transfer rate (ETR), and the photochemical quenching (qP), were also adversely affected. Algal photosynthetic and respiratory rates decreased following NSAID treatments, and the expression of genes involved in photosynthetic electron transport (psaA, psaB, psbB, psbD, and rbcL) was down-regulated. Furthermore, the functioning of the photosynthetic electron transport chain from PSI (photosystem I) to PSII, carbon assimilation, and photorespiration were affected. Our results suggest that NSAIDs can exert considerable toxic effects on the photosynthetic system of S. obliquus. These results provide a basis for evaluating the environmental safety of NSAIDs.


Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Fotossíntese/efeitos dos fármacos , Scenedesmus/efeitos dos fármacos , Carotenoides/análise , Clorofila/análise , Complexo de Proteína do Fotossistema II/efeitos dos fármacos
8.
ACS Appl Mater Interfaces ; 12(35): 39282-39292, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32805903

RESUMO

The Hoberman sphere is a stable and stretchable spatial structure with a unique design concept, which can be taken as the ideal prototype of the internal mechanical/conductive skeleton for the anode with large volume change. Herein, Mn3O4 nanoparticles are interlaced with a Hoberman sphere-like interconnected carbon nanotube (CNT) network via a facile self-assembly strategy in which Mn3O4 can "locally expand" in the CNT network, limit the volume expansion to the interior space, and maintain a stable outer surface of the hybrid particle. Furthermore, an ultrathin uniform ALD-coated TiO2 shell is adopted to stabilize the solid electrolyte interphase (SEI), provide high electron conductivity and lithium ion (Li+) diffusivity with lithiated LixTiO2, and enhance the reaction kinetics of the Mn3O4 by an "electron-density enhancement effect". With this design, the Mn3O4@CNT/TiO2 exhibits a high capacity of 1064 mAh g-1 at 0.1 A g-1, a stable cycling stability over 200 cycles, a superior rate capability, and a commercial-level areal capacity of 4.9 mAh cm-2. In this way, a novel electrode design strategy is achieved by the Hoberman sphere-like CNT design along with the in situ porous formation, which can not only achieve a high-performance anode for LIBs but also can be widely adapted in a variety of advanced electrode materials for alkali metal ion batteries.

9.
ACS Nano ; 14(4): 4741-4754, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32186848

RESUMO

Pursuing scalable production of porous carbon with facile and environmentally friendly synthesis methodology is a global goal. Herein, a unique hierarchical porous graphitic carbon (HPGC) with outstanding textural characteristics is achieved by a special synergistic activation mechanism, in which the low-temperature molten state of polymorphisms can induce a high-rate liquid phase porous activation. HPGC with high specific surface area (SSA, ∼2571 m2 g-1) and large pore volume (PV, ∼2.21 cm3 g-1) can be achieved, which also possesses the capability to tune textural characteristics (i.e., SSA, PV, pore size distribution, etc.) within a wide range. Furthermore, the pilot-scale production of HPGC is accomplished, which shows similar textural characteristics to the lab-scale HPGC. Due to the unique structure of HPGC and the capability of the textural control, it can be applicable in a variety of energy storage, energy conversion, and catalysis applications. The applications of pilot-scale HPGC products in supercapacitors and lithium sulfur batteries are highlighted in this work. Furthermore, the synergistic activation strategy can be promoted to other alkali-based carbon activation routes, which can open up new possibilities for the activated carbon production and lead to more widespread industrialized applications of HPGC.

10.
J Diabetes Res ; 2019: 9718370, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31534974

RESUMO

OBJECTIVE: In general population, resting heart rate (RHR) is associated with cardiovascular disease. However, its relation to chronic kidney disease (CKD) is debated. We therefore investigated the relationship between RHR and urinary albumin/creatinine ratio (UACR, an indicator of early kidney injury) in general population at different levels of blood pressure and blood glucose. METHODS: We screened out 32,885 subjects from the REACTION study after excluding the subjects with primary kidney disease, heart disease, tumor history, related drug application, and important data loss. The whole group was divided into four groups (Q1: RHR ≤ 71, Q2: 72 ≤ RHR ≤ 78, Q3: 79 ≤ RHR ≤ 86, and Q4: 87 ≤ RHR) according to the quartile of average resting heart rate. The renal function was evaluated by UACR (divided by quartiles of all data in the center to which the subject belonged). Ordinary logistic regression was carried out to explore the association between RHR and UACR at diverse blood pressure and blood glucose levels. RESULTS: The subjects with higher RHR quartile tend to have a higher UACR, even multifactors were adjusted. After stratifying the subjects according to blood pressure and blood glucose, the positive relationship between RHR and UACR remained in the subjects with normal blood pressure and normal glucose tolerance, while in the hypertension (SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg) group and the diabetic mellitus (FPG ≥ 7.0 mmol/L and/or PPG ≥ 11.1 mmol/L) group, the relationship disappeared. In the subjects without hypertension, compared with the Q1 group, the UACR is significant higher in the Q3 group (OR: 1.11) and the Q4 group (OR: 1.22). In the subjects with normal glucose tolerance (NGT), compared with the Q1 group, the UACR is significantly higher in the Q3 group (OR: 1.13) and the Q4 group (OR: 1.19). CONCLUSIONS: The population with higher RHR tend to have a higher UACR in the normal blood pressure group and the normal glucose tolerance group.


Assuntos
Albuminúria/urina , Creatinina/urina , Frequência Cardíaca/fisiologia , Idoso , Pressão Sanguínea/fisiologia , China , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Urinálise
11.
J Diabetes Res ; 2019: 9541638, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31871951

RESUMO

OBJECTIVE: Using the AMSTAR tool, this study evaluated the quality of systematic reviews (SRs) that assessed the efficacy of bariatric surgery in diabetic patients. We aimed to identify studies that can be used as clinical references. METHODS: Medline (via PubMed), EMBASE, Epistemonikos, Web of Science, Cochrane Library, CBM, CNKI, and Wanfang Data were systematically searched from inception to December 31, 2017. Two reviewers independently selected SRs and extracted data. Disagreements were solved by discussions or through consultation with a third reviewer. Reviewers extracted data (characteristics of included SRs, e.g., publication year, language, and number of authors) into the predefined tables in the Microsoft Excel 2013 sheet. Data were visualized using the forest plot in RevMan 5.3 software. RESULTS: A total of 64 SRs were included. The average AMSTAR score was 7.4 ± 1.7. AMSTAR scores of 7 (n = 21, 32.8%) and 8 (n = 14, 28.1%) were most common. The AMSTAR scores of SRs published before 2016 (n = 46, 71.9%) were compared with SRs published after 2016 (n = 18, 28.1%), and no significant differences were observed (MD = -0.79, 95% confidence interval (CI) -1.65-0.07, P = 0.07). For SRs published in Chinese (n = 17, 26.6%) compared to those published in English (n = 47, 73.4%), the AMSTAR scores significantly differed (MD = 0.21, 95% CI (-0.55, 0.97), P = 0.59). For SRs published in China (n = 33, 51.6%) compared to those published outside of China (n = 31, 48.4%), significant differences in the AMSTAR scores were observed (MD = 1.10, 95% CI (0.29, 1.91), P = 0.008). For SRs with an author number ≤ 6 (n = 31, 48.4%) compared to SRs with authors ≥ 6 (n = 33, 51.6%), no significant differences were observed (MD = -0.36, 95% CI (-1.22, 0.50), P = 0.41). For high-quality SRs published after 2016 (n = 11, 17.2%) compared to other SRs (n = 53, 82.8%), statistically significant differences were noted (MD = 1.75, 95% CI (1.01, 2.49), P < 0.00001). CONCLUSIONS: The number of SRs assessing the efficacy of bariatric surgery in diabetic patients is increasing by year, but only a small number meet the criteria to support guideline recommendations. Study protocols not being registered, grey literature not retrieved, incorporation of grey literature as exclusion criteria, and failure to evaluate publication bias and report a conflict of interest were the main causes of low AMSTAR scores.


Assuntos
Cirurgia Bariátrica , Diabetes Mellitus/cirurgia , Medicina Baseada em Evidências/normas , Obesidade/cirurgia , Revisões Sistemáticas como Assunto , Cirurgia Bariátrica/efeitos adversos , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia , Humanos , Obesidade/diagnóstico , Obesidade/epidemiologia , Viés de Publicação , Controle de Qualidade , Fatores de Risco , Resultado do Tratamento
12.
ACS Appl Mater Interfaces ; 11(37): 33987-33999, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31448888

RESUMO

Lithium sulfur (Li-S) batteries can offer great opportunities for the next-generation energy storage systems with tremendous energy density. However, challenges still exist in practical Li-S batteries including low sulfur utilization, and poor cycling stability and rate capability. Herein, we propose a novel hybrid catalyst structure by in situ implanting nanocrystal CoS2 in three-dimensional honeycomb-like hierarchical porous graphitic carbon (HPGC) for high-performance Li-S batteries. A unique synergistic absorption-catalysis-functional effect is demonstrated by comprehensive experimental and theoretical analysis: strong physical and chemical co-absorption effects are originated from the large quantity of microporous HPGC and the polar surface of metallic CoS2; the introduced nanocrystal CoS2 with a large specific area can impose an exceptional catalytic effect on the liquid-liquid, solid-liquid, and solid-solid phase redox reactions in Li-S batteries; the reaction dynamics are further guaranteed by the multifunctional properties of the HPGC backbone, including the capabilities in polysulfide sustention, reaction product transportation, electrolyte compensation, and efficiency in assisting diverse electrochemical reaction dynamics. In this way, our results not only develop a novel CoS2@HPGC structure, but also provide fundamental understanding on the catalytic dynamics during each reaction process. Moreover, we further propose the necessity and philosophy of the rational design of catalysts' special structure, which can fulfill the functional dynamics requirements of Li-S batteries, and can be promoted to other Li-S-related cathode design and composite catalytic structure design.

13.
ACS Appl Mater Interfaces ; 7(22): 12057-66, 2015 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-25992951

RESUMO

Li3V2(PO4)3 (LVP) particles dispersed in different inorganic carbons (LVP@C) have been successfully synthesized via an in situ synthesis method. The inorganic carbon materials with different dimensions including zero-dimensional Super P (SP) nanospheres, one-dimensional carbon nanotubes (CNTs), two-dimensional graphene nanosheets, and three-dimensional graphite particles. The effects of carbon dimensions on the structure, morphology, and electrochemical performance of LVP@C composites have been systematically investigated. The carbon materials can maintain their original morphology even after oxidation (by NH4VO3) and high-temperature sintering (850 °C). LVP@CNT exhibits the best electrochemical performances among all of the samples. At an ultrahigh discharge rate of 100C, it presents a discharge capacity of 91.94 mAh g(-1) (69.13% of its theoretical capacity) and maintains 79.82% of its original capacity even after 382 cycles. Its excellent electrochemical performance makes LVP@CNT a promising cathode candidate for lithium-ion batteries.

14.
Huan Jing Ke Xue ; 30(12): 3541-7, 2009 Dec.
Artigo em Zh | MEDLINE | ID: mdl-20187384

RESUMO

Nitrate pollution in groundwater is very widespread in intensive agricultural region. 394 samples from phreatic water wells and 283 samples from confined water wells were collected across Huantai County at the same season of 2002 and 2007, which is representative of high-yield region of North China Plain. The NO3- -N concentration was determined. Geostatistics combined with GIS technique were used to analyze the spatio-temporal variability of groundwater nitrate concentration. The average nitrate concentrations in phreatic water were 8.08 mg x L(-1) and 14.68 mg x L(-1) in 2002 and 2007 respectively, and that in confined water were 3.87 mg x L(-1) and 7.19 mg x L(-1) respectively. The spatial correlation distances of nitrate concentrations in confined water for both periods were greater than that in phreatic water. The mapping showed that the areas of phreatic groundwater with high levels of nitrate concentrations (10-15, 15-20, 20-30, and >30 mg x L(-1)) increased by 13.06%, 14.37%, 12.23%, and 3.85% from 2002 to 2007, while the area with low levels (0-5 and 5-10 mg x L(-1)) nitrate concentrations were decreased by 28.87% and 14.63% compared with 2002. However, the areas of confined water with nitrate concentrations of 5-10 mg x L(-1), 10-15 mg x L(-1) and 15-20 mg x L(-1) were increased by 28.01%, 9.33%, and 0.48% respectively, while the areas of NO3- -N concentration (0-5 mg x L(-1)) was decreased by 37.82%. The NO3- -N concentration in confined water was significantly negative related to groundwater depth for the two period, we found an increasing trend of NO3- -N concentration in the deeper confined water from 2002 to 2007.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Sistemas de Informação Geográfica , Nitratos/análise , Poluentes Químicos da Água/análise , Abastecimento de Água/análise , China , Monitoramento Ambiental , Nitrogênio/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA