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1.
Opt Lett ; 45(10): 2780-2783, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32412465

RESUMO

Wavelength shift, caused by temperature fluctuation, critically limits the application of photonic systems. Here, the waveguide geometry is optimized to minimize the wavelength shift due to temperature change and fabrication error. A temperature-insensitive Mach-Zehnder interferometer filter is proposed for a wavelength locker, based on a silicon nitride waveguide. The proposed device achieves a 0.6 pm/K spectral shift over the C-band, which meets the requirements of a wavelength locker for application in dense wavelength division multiplex systems.

2.
Nanotechnology ; 31(29): 295404, 2020 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-32241005

RESUMO

The poor conductivity of sulfur and the 'shuttle effect' of polysulfide intermediates have hindered the development of next generation lithium-sulfur (Li-S) batteries with high energy and low consumption. Herein, novel Co9S8-S composite nanotubes are developed to efficiently alleviate the above-mentioned problems. Experiments and theoretical calculations show that Co9S8 has strong adsorption on soluble polysulfides. This not only restrains polysulfides diffusion and ensures their utilization, but also enhances the intimate contact between the active materials and the conductive substrates to promote the kinetics of conversion reactions. The three-dimensional (3D) conductive network with a high surface area formed by interlinking Co9S8 nanotubes further improves the electronic conductivity of the composite cathode. As a result, the Co9S8-S cathode shows a high capacity of 1153 mAh g-1. After 500 cycles, a high capacity of 462 mAh g-1 (2 C) is demonstrated with a negligible capacity decay of ~0.04% per cycle.

3.
J Am Chem Soc ; 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32250611

RESUMO

Electrocatalytic CO2 reduction (CO2RR) to valuable fuels is a promising approach to mitigate energy and environmental problems, but controlling the reaction pathways and products remains challenging. Here a novel Cu2O nanoparticle film was synthesized by square-wave (SW) electrochemical redox cycling of high-purity Cu foils. The cathode afforded up to 98% Faradaic efficiency for electroreduction of CO2 to nearly pure formate under ≥45 atm CO2 in bicarbonate catholytes. When this cathode was paired with a newly developed NiFe hydroxide carbonate anode in KOH/borate anolyte, the resulting two-electrode high-pressure electrolysis cell achieved high energy conversion efficiencies of up to 55.8% stably for long-term formate production. While the high-pressure conditions drastically increased the solubility of CO2 to enhance CO2 reduction and suppress hydrogen evolution, the (111)-oriented Cu2O film was found to be important to afford nearly 100% CO2 reduction to formate. The results have implications for CO2 reduction to a single liquid product with high energy conversion efficiency.

4.
Int J Pharm ; 580: 119241, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32197982

RESUMO

Doxorubicin (DOX) is a broad-spectrum anti-tumor drug, but it has certain limitations in its therapeutic effects due to poor tumor selectivity. Chitosan-based pH-sensitive polymers drug delivery systems could improve DOX's activity and selectivity against tumor cells. Understanding the atomic interaction mechanism between chitosan and DOX at different pH levels is important in the design and application of chitosan-based drug delivery systems. In this study, molecular dynamics simulations were performed to investigate the encapsulation and release of DOX by chitosan at different pH levels. Our results show that the protonation state of amine groups of chitosan and the π-π stacking interaction between the conjugated anthraquinone ring of DOX regulate the interaction behavior between chitosan and DOX. Moreover, DOX could gradually release from chitosan at acidic pH environment in tumor tissue. These results revealed the underlying atomic interaction mechanism between DOX and chitosan at various pH levels and may provide novel ideas for the design and application of chitosan-based drug delivery system.

5.
Bioresour Technol ; 304: 123064, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32115346

RESUMO

In this study, a novel psychrotrophic lignocelluloses degrading microbial consortium LTF-27 was successfully obtained from cold perennial forest soil by successive enrichment culture under facultative anaerobic static conditions. The microbial consortium showed efficient degradation of rice straw, which cellulose, hemicelluloses and lignin lost 71.7%, 65.6% and 12.5% of its weigh, respectively, in 20 days at 15 °C. The predominant liquid products were acetic acid and butyric acid during degrading lignocellulose in anaerobic digestion (AD) process inoculated with the LTF-27. The consortium mainly composed of Parabacteroides, Alcaligenes, Lysinibacillus, Sphingobacterium, and Clostridium, along with some unclassified uncultured bacteria, indicating powerful synergistic interaction in AD process. A multi-species lignocellulolytic enzyme system working cooperatingly on lignocelluolse degradation was revealed by proteomics analysis of cellulose bound fraction of the crude extracellular enzyme, which provides key theoretical base for further exploration and application of LTF-27.


Assuntos
Consórcios Microbianos , Oryza , Bactérias , Celulose , Lignina , Temperatura
6.
Pharmazie ; 75(1): 18-22, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-32033628

RESUMO

Salvia miltiorrhiza (Danshen) is typically used in the treatment of diabetic complications and is often co-prescribed with gliquidone in China. However, whether danshen affects the absorption of gliquidone has not been elucidated. In this study, the effects of an aqueous extract of danshen (danshen injection, DSI) and its primary compounds (danshensu, protocatechuic aldehyde, rosmarinic acid and salvianolic acid B) on gliquidone transport across Caco-2 monolayer cells was investigated. DSI enhanced the transport of gliquidone in Caco-2 cell monolayers from the apical (AP) to basolateral (BL) sides and from the BL to AP sides. Rosmarinic acid (RA) also significantly increased the Papp (AP-BL) value for gliquidone transport. Verapamil (a P-gp inhibitor) and Ko143 (a BCRP inhibitor) inhibited the BL-AP transport of gliquidone and promoted the AP-BL transport of gliquidone, whereas MK571 (an MRP1 inhibitor), probenecid (an MRP2 inhibitor), and benzbromarone (an MRP3 inhibitor) had no effect on gliquidone transport. RA also enhanced the intracellular accumulation of Rho123 and Hoechst 33342. The expression of P-gp and BCRP was significantly downregulated, and P-gp ATPase activity was promoted by RA in a dose-dependent manner. These results indicate that an aqueous extract of danshen can increase the transport of gliquidone in Caco-2 cell monolayers and that RA may be the primary compound associated with this activity, which is in agreement with RA simultaneously suppressing the function and expression of P-gp and BCRP.

7.
Eur Respir J ; 55(4)2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31980495

RESUMO

Bodyweight and fat distribution may be related to COPD risk. Limited prospective evidence linked COPD to abdominal adiposity. We investigated the association of body mass index (BMI) and measures of abdominal adiposity with COPD risk in a prospective cohort study.The China Kadoorie Biobank recruited participants aged 30-79 years from 10 areas across China. Anthropometric indexes were objectively measured at the baseline survey during 2004-2008. After exclusion of participants with prevalent COPD and major chronic diseases, 452 259 participants were included and followed-up until the end of 2016. We used Cox models to estimate adjusted hazard ratios relating adiposity to risk of COPD hospitalisation or death.Over an average of 10.1 years of follow-up, 10 739 COPD hospitalisation events and deaths were reported. Compared with subjects with normal BMI (18.5-<24.0 kg·m-2), underweight (BMI <18.5 kg·m-2) individuals had increased risk of COPD, with adjusted hazard ratio 1.78 (95% CI 1.66-1.89). Overweight (BMI 24.0-<28.0 kg·m-2) and obesity (BMI ≥28.0 kg·m-2) were not associated with an increased risk after adjustment for waist circumference. A higher waist circumference (≥85 cm for males and ≥80 cm for females) was positively associated with COPD risk after adjustment for BMI. Additionally, waist-to-hip ratio and waist-to-height ratio were positively related to COPD risk.Abdominal adiposity and underweight were risk factors for COPD in Chinese adults. Both BMI and measures of abdominal adiposity should be considered in the prevention of COPD.

8.
Environ Sci Pollut Res Int ; 27(10): 11026-11037, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31953769

RESUMO

Diesel particle filter (DPF) has been widely acknowledged as the most effective way to mitigate particulate matter emitted from diesel engines. Over time, ash mainly derived from lubricating oil will deposit in DPF, showing negative influence to engine performance, fuel economy, service life of DPF, and so on. Recently, the investigation about DPF backpressure characteristics and DPF regeneration process considering ash has gained attention. As a porous material, ash will play a key role in the DPF permeability. Thus, the pore morphology and fractal dimension of ash derived from three kinds of lube are addressed in this work. The results show that the changing tendency of the micropore specific surface and pore volume is consistent with the ash content in lubricant oil, which is owing to the chemical interaction of Ca and S contained in the oil during the complex DPF regeneration. There is no significant changing tendency of the mesopore and macropore properties because of the heterogeneity and complexity of ash. According to the fractal analyses, the Avnir equation shows excellent predictive accuracy for the pore surface fractal dimension of ash, which reflects that the ash pore surfaces are irregular.

9.
Mol Cancer ; 19(1): 15, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980023

RESUMO

Cancer metastasis is the leading cause of cancer-related death. Circulating tumor cells (CTCs) are shed into the bloodstream from either primary or metastatic tumors during an intermediate stage of metastasis. In recent years, immunotherapy has also become an important focus of cancer research. Thus, to study the relationship between CTCs and immunotherapy is extremely necessary and valuable to improve the treatment of cancer. In this review, based on the advancements of CTC isolation technologies, we mainly discuss the clinical applications of CTCs in cancer immunotherapy and the related immune mechanisms of CTC formation. In order to fully understand CTC formation, sufficiently and completely understood molecular mechanism based on the different immune cells is critical. This understanding is a promising avenue for the development of effective immunotherapeutic strategies targeting CTCs.

10.
J Mater Chem B ; 8(3): 546-557, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31854435

RESUMO

The development of drug delivery systems based on external stimuli-responsive nanocarriers is important to overcome multidrug resistance in breast cancer cells. Herein, iron oxide/gold (Fe3O4/Au) nanoparticles were first fabricated via a simple hydrothermal reaction, and subsequently loaded into porous silicon nanoparticles (PSiNPs) via electrostatic interactions to construct PSiNPs@(Fe3O4/Au) nanocomposites. The as-prepared PSiNPs@(Fe3O4/Au) nanocomposites exhibited excellent super-paramagnetism, photothermal effect, and T2-weight magnetic resonance imaging capability. In particular, with the help of a magnetic field, the cellular uptake of PSiNPs@(Fe3O4/Au) nanocomposites was significantly enhanced in drug-resistant breast cancer cells. Moreover, PSiNPs@(Fe3O4/Au) nanocomposites as carriers showed a high loading and NIR light-triggered release of anticancer drugs. Based on the synergistic effect of magnetic field-enhanced cellular uptake and NIR light-triggered intracellular release, the amount of anticancer drug carried by PSiNPs@(Fe3O4/Au) nanocarriers into the nuclei of drug-resistant breast cancer cells sharply increased, accompanied by improved chemo-photothermal therapeutic efficacy. Finally, PSiNPs@(Fe3O4/Au) nanocomposites under the combined conditions of magnetic field attraction and NIR light irradiation also showed improved anticancer drug penetration and accumulation in three-dimensional multicellular spheroids composed of drug-resistant breast cancer cells, leading to a better growth inhibition effect. Overall, the fabricated PSiNPs@(Fe3O4/Au) nanocomposites demonstrated great potential for the therapy of multidrug-resistant breast cancer in future.

11.
Artigo em Inglês | MEDLINE | ID: mdl-31811026

RESUMO

Optogenetics, which uses visible light to control the cells genetically modified with light-gated ion channels, is a powerful tool for precise deconstruction of neural circuitry with neuron-subtype specificity. However, due to limited tissue penetration of visible light, invasive craniotomy and intracranial implantation of tethered optical fibers are usually required for in vivo optogenetic modulation. Here we report mechanoluminescent nanoparticles that can act as local light sources in the brain when triggered by brain-penetrant focused ultrasound (FUS) through intact scalp and skull. Mechanoluminescent nanoparticles can be delivered into the blood circulation via i.v. injection, recharged by 400-nm photoexcitation light in superficial blood vessels during circulation, and turned on by FUS to emit 470-nm light repetitively in the intact brain for optogenetic stimulation. Unlike the conventional "outside-in" approaches of optogenetics with fiber implantation, our method provides an "inside-out" approach to deliver nanoscopic light emitters via the intrinsic circulatory system and switch them on and off at any time and location of interest in the brain without extravasation through a minimally invasive ultrasound interface.

12.
Phys Rev E ; 100(5-1): 052409, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31869999

RESUMO

Natural enzymes often have enormous catalytic power developed by evolution. Revealing the underlying physical strategy used by enzymes to achieve high catalysis efficiency is one of the central focuses in the field of biological physics. Our recent work demonstrated that multisubstrate enzymes can utilize steric frustration encountered in the substrate-product cobound complex to overcome the bottleneck of the enzymatic cycle [W. Li et al., Phys. Rev. Lett. 122, 238102 (2019)10.1103/PhysRevLett.122.238102]. However, the key atomic-level interactions by which the steric frustration contributes to the enzymatic cycle remain elusive. In this work we study the microscopic mechanism for the role of the substrate-product frustration on the key physical steps in the enzymatic cycle of adenylate kinase (AdK), a multisubstrate enzyme catalyzing the reversible phosphoryl transfer reaction ATP+AMP⇋ADP+ADP. By using atomistic molecular dynamics simulations with enhanced sampling, we showed that the competitive interactions from the phosphate groups of the substrate ATP and product ADP in the ATP-ADP cobound complex of the AdK lead to local frustration in the binding pockets. Such local frustration disrupts the hydrogen bond network around the binding pockets, which causes lowered barrier height for the opening of the enzyme conformations and expedited release of the bottleneck product ADP. Our results directly demonstrated from the atomistic level that the local frustration in the active sites of the enzyme can be utilized to facilitate the key physical steps of the enzymatic cycle, providing numerical evidence to the predictions of the previous theoretical work.


Assuntos
Adenilato Quinase/metabolismo , Simulação de Dinâmica Molecular , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Adenilato Quinase/química , Sítios de Ligação , Cinética , Ligação Proteica , Conformação Proteica , Termodinâmica
13.
Opt Express ; 27(23): 33575-33585, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31878423

RESUMO

The significant frequency drift of integrated microwave photonic filters (IMPFs) is caused by relatively independent frequency fluctuations of the optical carrier and the photonic integrated filter, which imposes a rigid limitation on the practical application. In this paper, a novel method is proposed for suppressing the frequency drift of IMPFs. The scheme is implemented by utilizing an on-chip high-Q microring resonator as a frequency monitoring unit to track the instantaneous frequency drifts caused by the optical carrier drift and the temperature fluctuations of the photonic integrated chip. And the same frequency tuning is simultaneously applied on the photonic integrated filter to suppress the frequency drift of IMPFs based on the differential scheme. As a proof of concept, the proposed IMPF scheme is demonstrated on the Si3N4 platform, and the frequency drift is measured to be tens of MHz in one hour. Compared with conventional IMPF schemes, the frequency drift is significantly suppressed by 86.3% without using complex laser frequency stabilization and temperature control systems.

14.
Nat Biotechnol ; 37(11): 1322-1331, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31570897

RESUMO

The near-infrared-IIb (NIR-IIb) (1,500-1,700 nm) window is ideal for deep-tissue optical imaging in mammals, but lacks bright and biocompatible probes. Here, we developed biocompatible cubic-phase (α-phase) erbium-based rare-earth nanoparticles (ErNPs) exhibiting bright downconversion luminescence at ~1,600 nm for dynamic imaging of cancer immunotherapy in mice. We used ErNPs functionalized with cross-linked hydrophilic polymer layers attached to anti-PD-L1 (programmed cell death-1 ligand-1) antibody for molecular imaging of PD-L1 in a mouse model of colon cancer and achieved tumor-to-normal tissue signal ratios of ~40. The long luminescence lifetime of ErNPs (~4.6 ms) enabled simultaneous imaging of ErNPs and lead sulfide quantum dots emitting in the same ~1,600 nm window. In vivo NIR-IIb molecular imaging of PD-L1 and CD8 revealed cytotoxic T lymphocytes in the tumor microenvironment in response to immunotherapy, and altered CD8 signals in tumor and spleen due to immune activation. The cross-linked functionalization layer facilitated 90% ErNP excretion within 2 weeks without detectable toxicity in mice.


Assuntos
Antineoplásicos Imunológicos/administração & dosagem , Antígeno B7-H1/imunologia , Neoplasias do Colo/tratamento farmacológico , Érbio/química , Animais , Antineoplásicos Imunológicos/química , Antineoplásicos Imunológicos/farmacologia , Antígenos CD8/metabolismo , Linhagem Celular Tumoral , Neoplasias do Colo/imunologia , Imunoterapia , Raios Infravermelhos , Camundongos , Nanopartículas , Imagem Óptica , Pontos Quânticos , Linfócitos T Citotóxicos/imunologia , Microambiente Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Nat Commun ; 10(1): 3302, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31341162

RESUMO

Rechargeable sodium metal batteries with high energy density could be important to a wide range of energy applications in modern society. The pursuit of higher energy density should ideally come with high safety, a goal difficult for electrolytes based on organic solvents. Here we report a chloroaluminate ionic liquid electrolyte comprised of aluminium chloride/1-methyl-3-ethylimidazolium chloride/sodium chloride ionic liquid spiked with two important additives, ethylaluminum dichloride and 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide. This leads to the first chloroaluminate based ionic liquid electrolyte for rechargeable sodium metal battery. The obtained batteries reached voltages up to ~ 4 V, high Coulombic efficiency up to 99.9%, and high energy and power density of ~ 420 Wh kg-1 and ~ 1766 W kg-1, respectively. The batteries retained over 90% of the original capacity after 700 cycles, suggesting an effective approach to sodium metal batteries with high energy/high power density, long cycle life and high safety.

16.
Biomed Pharmacother ; 116: 108995, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31121484

RESUMO

Gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), has been widely used as a first-line agent in EGFR-mutant non-small cell lung cancer (NSCLC). Nevertheless, the development of chemoresistance ultimately limited the curative effect of anti-cancer drugs. The present study aims to investigate the functions of SNHG14 in gefitinib resistance and gain insight into the underlying molecular mechanisms. In the present study, we found that SNHG14 expression was elevated and miR-206-3p expression was decreased in gefitinib-resistant NSCLC tumor tissues and cells. Functionally, SNHG14 overexpression increased gefitinib resistance by promoting cell viability, lowering apoptosis and enhancing colony forming ability, while SNHG14 knockdown reduced gefitinib resistance in NSCLC cells. Mechanistically, SNHG14 induced ABCB1 expression via interaction with miR-206-3p. Moreover, depletion of SNHG14 enhanced the sensitivity of NSCLC cells to gefitinib in vivo. Together, SNHG14 confers gefitinib resistance in NSCLC by regulating miR-206-3p/ABCB1 pathway, contributing to a better understanding of SNHG14 in acquired resistance and elucidating a candidate target to improve treatment response of NSCLC patients.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Resistencia a Medicamentos Antineoplásicos/genética , Gefitinibe/uso terapêutico , Neoplasias Pulmonares/genética , MicroRNAs/metabolismo , RNA Nucleolar Pequeno/metabolismo , Regulação para Cima/genética , Regiões 3' não Traduzidas/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Animais , Sequência de Bases , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Feminino , Gefitinibe/farmacologia , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Neoplasias Pulmonares/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , RNA Nucleolar Pequeno/genética
17.
J Cardiothorac Surg ; 14(1): 90, 2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31064409

RESUMO

BACKGROUND: Thoracic aortic surgery and cardiopulmonary bypass are both associated with development of postoperative acute kidney injury. In this study, we undertook to investigate the relationship between cardiopulmonary bypass time and postoperative acute kidney injury in patients undergoing thoracic aortic surgery for acute DeBakey Type I aortic dissection. METHODS: All patients receiving thoracic aortic surgery for acute DeBakey Type I aortic dissection in Beijing Anzhen hospital from December 2015 to April 2017 were included. Cardiopulmonary bypass time was recorded during surgery. Acute kidney injury was defined based on the Kidney Disease Improving Global Outcomes criteria. A total of 115 consecutive patients were eventually analyzed. RESULTS: The overall incidence of acute kidney injury was 53.0% (n = 61). The average age was 47.8 ± 10.7 years; 74.8% were male. Mean cardiopulmonary bypass time was 211 ± 56 min. In-hospital mortality was 7.8%. Multivariate logistic regression revealed that cardiopulmonary bypass time was independently associated with the occurrence of postoperative acute kidney injury after adjust confounding factors (odds ratio = 1.171; 95% confidence interval: 1.002-1.368; P = 0.047). CONCLUSIONS: Cardiopulmonary bypass time is independently associated with an increased hazard of acute kidney injury after thoracic aortic surgery for acute DeBakey Type I aortic dissection. Further understanding of the mechanism of this association is crucial to the design of preventative strategies.


Assuntos
Lesão Renal Aguda/etiologia , Aneurisma Dissecante/cirurgia , Aorta Torácica/cirurgia , Aneurisma da Aorta Torácica/cirurgia , Ponte Cardiopulmonar/efeitos adversos , Procedimentos Cirúrgicos Torácicos/efeitos adversos , Lesão Renal Aguda/diagnóstico , Lesão Renal Aguda/mortalidade , Adulto , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
18.
Environ Health Perspect ; 127(5): 57008, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31095433

RESUMO

BACKGROUND: Solid fuels are widely used in China. Household air pollution from the burning of solid fuels may increase the risk of chronic obstructive pulmonary disease (COPD), but prospective evidence is limited. OBJECTIVES: We examined the association of solid fuel use for cooking and heating with the risk of COPD in a prospective cohort study. METHODS: Participants were from the China Kadoorie Biobank. Current and previous fuels used for household cooking and heating were self-reported at baseline in 2004­2008. In the present study, "solid fuels" refers to coal and wood, whereas "cleaner fuels" refers to energy sources that presumably produce lower levels of indoor pollution, including electricity, gas, and central heating. A total of 475,827 adults 30­79 y of age without prevalent COPD were followed through the end of 2015. We used adjusted Cox regression models to estimate hazard ratios for COPD. RESULTS: Over 9.1 y of follow-up, 9,835 incident COPD cases were reported. Compared with the use of cleaner fuels for cooking, using coal and wood for cooking was positively associated with COPD, with fully adjusted HRs of 1.06 (95% CI: 0.98, 1.15) and 1.14 (95% CI: 1.06, 1.23), respectively. Adjusted HRs for heating with coal and wood were 1.16 (95% CI: 1.04, 1.29) and 1.21 (95% CI: 1.09, 1.35), respectively. The positive association between cooking with solid fuel and COPD appeared to be limited to women and never- (vs. ever-) smokers. COPD risk increased with a higher number of years of solid fuel use for heating and wood use for cooking. CONCLUSIONS: The use of solid fuel for cooking and heating was associated with the increased risk of COPD in this prospective cohort study. Studies with more accurate exposure assessment are needed to confirm the association. https://doi.org/10.1289/EHP2856.

19.
Nat Commun ; 10(1): 1896, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31015466

RESUMO

Lithium metal anodes hold great promise to enable high-energy battery systems. However, lithium dendrites at the interface between anode and separator pose risks of short circuits and fire, impeding the safe application. In contrast to conventional approaches of suppressing dendrites, here we show a deposition-regulating strategy by electrically passivating the top of a porous nickel scaffold and chemically activating the bottom of the scaffold to form conductivity/lithiophilicity gradients, whereby lithium is guided to deposit preferentially at the bottom of the anode, safely away from the separator. The resulting lithium anodes significantly reduce the probability of dendrite-induced short circuits. Crucially, excellent properties are also demonstrated at extremely high capacity (up to 40 mAh cm-2), high current density, and/or low temperatures (down to -15 °C), which readily induce dendrite shorts in particular. This facile and viable deposition-regulating strategy provides an approach to preferentially deposit lithium in safer positions, enabling a promising anode for next-generation lithium batteries.

20.
ACS Appl Mater Interfaces ; 10(43): 36892-36901, 2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-30295450

RESUMO

The conversion reaction of lithia can push up the capacity limit of tin oxide-based anodes. However, the poor reversibility limits the practical applications of lithia in lithium-ion batteries. The latest reports indicate that the reversibility of lithia has been appropriately promoted by compositing tin oxide with transition metals. The underlying mechanism is not revealed. To design better anodes, we studied the nanostructured metal/Li2O interfaces through atomic-scale modeling and proposed a porous nanoframe structure of Mn/Sn binary oxides. The first-principles calculation implied that because of a low interface energy of metal/Li2O, Mn forms smaller particles in lithia than Sn. Ultrafine Mn nanoparticles surround Sn and suppress the coarsening of Sn particles. Such a composite design and the resultant interfaces significantly enhance the reversible Li-ion storage capabilities of tin oxides. The synthesized nanoframes of manganese tin oxides exhibit an initial capacity of 1620.6 mA h g-1 at 0.05 A g-1. Even after 1000 cycles, the nanoframe anode could deliver a capacity of 547.3 mA h g-1 at 2 A g-1. In general, we demonstrated a strategy of nanostructuring interfaces with low interface energy to enhance the Li-ion storage capability of binary tin oxides and revealed the mechanism of property enhancement, which might be applied to analyze other tin oxide composites.

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