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1.
Opt Express ; 28(1): 760-772, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-32118998

RESUMO

We systematically investigate the generation of optical chirality patterns by applying the superposition of two waves in three scenarios, namely free-space plane waves, evanescent waves of totally reflected light at dielectric interface and propagating surface plasmon waves on a metallic surface. In each scenario, the general analytical solution of the optical chirality pattern is derived for different polarization states and propagating directions of the two waves. The analytical solutions are verified by numerical simulations. Spatially structured optical chirality patterns can be generated in all scenarios if the incident polarization states and propagation directions are correctly chosen. Optical chirality enhancement can be obtained from the constructive interference of free-space circularly polarized light or enhanced evanescent waves of totally reflected light. Surface plasmon waves do not provide enhanced optical chirality unless the near-field intensity enhancement is sufficiently high. The structured optical chirality patterns may find applications in chirality sorting, chiral imaging and circular dichroism spectroscopy.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32030866

RESUMO

Voltage decay and capacity fading are the main challenges for the commercialization of Li-rich Mn-based layered oxides (LLOs). Now, a three-in-one surface treatment is designed via the pyrolysis of urea to improve the voltage and capacity stability of Li1.2 Mn0.6 Ni0.2 O2 (LMNO), by which oxygen vacancies, spinel phase integration, and N-doped carbon nanolayers are synchronously built on the surface of LMNO microspheres. Oxygen vacancies and spinel phase integration suppress irreversible O2 release and help lithium ion diffusion, while N-doped carbon nanolayer mitigates the corrosion of electrolyte with excellent conductivity. The electrochemical performance of LMNO after the treatment improves significantly; the capacity retention rate after 500 cycles at 1 C is still as high as 89.9 % with a very small voltage fading rate of 1.09 mV cycle-1 . This three-in-one surface treatment strategy can suppress the voltage decay and capacity fading of LLOs.

3.
Small ; : e1906374, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32077623

RESUMO

Critical to the development of all-solid-state lithium-ion batteries technology are novel solid-state electrolytes with high ionic conductivity and robust stability under inorganic solid-electrolyte operating conditions. Herein, by using density functional theory and molecular dynamics, a mixed oxygen-sulfur-based Li-superionic conductor is screened out from the local chemical structure of ß-Li3 PS4 to discover novel Li14 P2 Ge2 S8 O8 (LPGSO) with high ionic conductivity and high stability under thermal, moist, and electrochemical conditions, which causes oxygenation at specific sites to improve the stability and selective sulfuration to provide an O-S mixed path by Li-S/O structure units with coordination number between 3 and 4 for fast Li-cooperative conduction. Furthermore, LPGSO exhibits a quasi-isotropic 3D Li-ion cooperative diffusion with a lesser migration barrier (≈0.19 eV) compared to its sulfide-analog Li14 P2 Ge2 S16 . The theoretical ionic conductivity of this conductor at room temperature is as high as ≈30.0 mS cm-1 , which is among the best in current solid-state electrolytes. Such an oxy-sulfide synergistic effect and Li-ion cooperative migration mechanism would enable the engineering of next-generation electrolyte materials with desirable safety and high ionic conductivity, for possible application in the near future.

4.
ACS Appl Mater Interfaces ; 12(5): 6007-6014, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31941270

RESUMO

A crystalline solid electrolyte interphase Li2CO3 material with a large band gap shows promise toward next-generation all-solid-state lithium batteries (ASSLBs). However, the inferior ionic diffusivity restricts such structures to a real battery setup. Herein, based on density functional theory calculation and Python materials genomics, we theoretically develop the chemistry and local structural motifs to build a mixed boron-carbon framework Li2+xC1-xBxO3 (LCBO). We examine the electrochemical and chemical stabilities of LCBO-electrode interfaces by analyzing the thermodynamics of formation of interfacial phases. Interestingly, the LCBO material is automatically protected from further decomposition through the self-generated resistive interphase (Li2CO3 and Li3BO3), which gives a wide range of operating potential. LCBO shows high interfacial stability with LiCoO2, LiMnO2, and LiMn2O4. More importantly, the theoretical Li-ion migration barrier of LCBO (x = 0.375) is approximately 0.23 ± 0.02 eV through a cooperative migration mechanism. Therefore, the LCBO material combines high Li-ion diffusivity with good interfacial stability, which makes it a promising solid-state electrolyte material for ASSLBs.

5.
Nat Commun ; 11(1): 299, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31941896

RESUMO

Downsizing the cell size of honeycomb monoliths to nanoscale would offer high freedom of nanostructure design beyond their capability for broad applications in different fields. However, the microminiaturization of honeycomb monoliths remains a challenge. Here, we report the fabrication of microminiaturized honeycomb monoliths-honeycomb alumina nanoscaffold-and thus as a robust nanostructuring platform to assemble active materials for micro-supercapacitors. The representative honeycomb alumina nanoscaffold with hexagonal cell arrangement and 400 nm inter-cell spacing has an ultrathin but stiff nanoscaffold with only 16 ± 2 nm cell-wall-thickness, resulting in a cell density of 4.65 × 109 cells per square inch, a surface area enhancement factor of 240, and a relative density of 0.0784. These features allow nanoelectrodes based on honeycomb alumina nanoscaffold synergizing both effective ion migration and ample electroactive surface area within limited footprint. A micro-supercapacitor is finally constructed and exhibits record high performance, suggesting the feasibility of the current design for energy storage devices.

6.
Chem Commun (Camb) ; 56(5): 786-789, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31845676

RESUMO

Lithium-sulfur batteries are one of the most promising candidates for next-generation energy storage systems. The major challenge hindering their commercialization is the polysulfide shuttle effect, which causes a series of problems including the loss of active materials, corrosion of the lithium anode, low coulombic efficiency, and poor cycling performance. In this work, we develop a mesoporous silica-based cathode for efficient trapping of lithium polysulfides (LiPSs). This cathode material consists of mesoporous silica (HMS), highly dispersed NiO nanoparticles embedded in the silica structure, and a conductive polymer (polypyrrole-ppy) prepared by in situ polymerization. We employ the concept of both the physical and chemical entrapment of LiPSs, i.e., physically trapping LiPSs by spatial confinement of LiPSs in the silica porous structure and physical adsorption of LiPSs by the silica surface, and chemically binding LiPSs by highly dispersed NiO nanoparticles in the silica structure. The NiO/silica/ppy/S cathode exhibits good cycling stability and maintains over 700 mA h g-1 after 300 cycles. As far as we know, this is the first time that mesoporous silica has been directly employed as a sulfur host material, rather than an additive. The present study opens up a window for nanoporous silica to be employed as the sulfur host.

7.
J Food Drug Anal ; 28(1): 38-59, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31883608

RESUMO

Antcins are unique phytosterols isolated from A. cinnamomea and A. salmomea, which are the endemic fungus of Taiwan. A. cinnamomea has long been highly valued medicinal mushroom in Taiwan and traditionally used as a folk remedy for various human illness. Recent scientific explorations claimed that the pharmacological activities of A. cinnamomea and A. salmomonea are gone beyond their original usage. The therapeutic efficacy of these medicinal mushrooms was attributed to their high content of unique bioactive secondary metabolites, including terpenoids, benzenoids, ubiquinol derivatives, polysaccharides, lignans, nucleic acids, steroids, and maleic/succinic acid derivatives. Antcins is a group of steroids in Antrodia spp. with ergostane skeleton received much attention in Taiwan's academic circle due to their broad-spectrum of biological activities. At present, twelve antcins, i.e. antcin A, B, C, D, E, F, G, H, I, K, M, and N along with twelve derivatives/epimers (25R/S-antcin A, B, C, H, I and K) and seven analogs (methyl antcinate A, B, G, H, K, L and N) were identified. Several studies have demonstrated that antcins possessed anti-cancer, anti-inflammation, anti-oxidant, anti-diabetic, anti-aging, immunomodulation, hepatoprotection, and hypolipedimic activities. The main goal of this review is to define the chemistry, isolation, advances in production, and biological activities of antcins and their derivatives/analogs. Special attention has been given to a detail view of their biological activities in vitro and in vivo and their pharmacological potentials.

8.
Adv Mater ; 32(7): e1906357, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31880000

RESUMO

Lithium-sulfur (Li-S) batteries are considered to be one of the most promising candidate systems for next-generation electrochemical energy storage. The major challenge of this system is the polysulfide shuttle, which results in poor cycling efficiency. In this work, a highly N-doped carbon/graphene (NC/G) sheet is designed as a sulfur host, which combines the merits of abundant N active sites and high electrical conductivity to achieve in situ anchoring-conversion of lithium polysulfides (LiPSs). Such a host not only has strong binding with LiPSs but also promotes redox kinetics, which are revealed by both experimental investigations and theoretical studies. The sulfur cathode based on the NC/G host exhibits a high initial capacity of 1380 mA h g-1 and a superior cycle stability with a low capacity decay of 0.037% per cycle within 500 cycles at 2 C. Steady areal capacity with a high sulfur loading (5.6 mg cm-2 ) is also attained even without the addition of LiNO3 in the electrolyte. This work proposes and illustrates the importance of in situ anchoring-conversion of LiPSs, offering a new strategy to design multifunctional sulfur hosts for high-performance Li-S batteries.

9.
Microorganisms ; 7(9)2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31505744

RESUMO

Pennisetum sinese is a good forage grass with high biomass production and crude proteins. However, little is known about the endophytic fungi diversity of P. sinese, which might play an important role in the plant's growth and biomass production. Here, we used high throughput sequencing of the Internal Transcribed Spacer (ITS) sequences based on primers ITS5-1737 and ITS2-2043R to investigate the endophytic fungi diversity of P. sinese roots at the maturity stage, as collected from four provinces (Shaanxi province, SX; Fujian province, FJ; the Xinjiang Uyghur autonomous prefecture, XJ and Inner Mongolia, including sand (NS) and saline-alkali land (NY), China). The ITS sequences were processed using QIIME and R software. A total of 374,875 effective tags were obtained, and 708 operational taxonomic units (OTUs) were yielded with 97% identity in the five samples. Ascomycota and Basidiomycota were the two dominant phyla in the five samples, and the genera Khuskia and Heydenia were the most abundant in the FJ and XJ samples, respectively, while the most abundant tags in the other three samples could not be annotated at the genus level. In addition, our study revealed that the FJ sample possessed the highest OTU numbers (242) and the NS sample had the lowest (86). Moreover, only 22 OTUs were present in all samples simultaneously. The beta diversity analysis suggested a division of two endophytic fungi groups: the FJ sample from the south of China and the other four samples from north or northwest China. Correlation analysis between the environmental factors and endophytic fungi at the class level revealed that Sordariomycetes and Pucciniomycetes had extremely significant positive correlations with the total carbon, annual average precipitation, and annual average temperature, while Leotiomycetes showed an extremely significant negative correlation with quick acting potassium. The results revealed significant differences in the root endophytic fungi diversity of P. sinese in different provinces and might be useful for growth promotion and biomass production in the future.

10.
Chem Commun (Camb) ; 55(77): 11638-11641, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31508611

RESUMO

Hollow-sphere Fe2O3 is synthesized as a lithium-ion battery anode. Current densities for the initial material activation are important, related to electrode stability during cycling. The as-prepared anodes are able to retain 92% capacity after 1000 cycles at 1 A g-1. The full-cells assembled with Fe2O3 anodes and LiFePO4 cathodes exhibit good electrochemical properties.

11.
Nat Commun ; 10(1): 1965, 2019 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-31036805

RESUMO

Large-scale applications of rechargeable batteries consume nonrenewable resources and produce massive amounts of end-of-life wastes, which raise sustainability concerns in terms of manufacturing, environmental, and ecological costs. Therefore, the recyclability and sustainability of a battery should be considered at the design stage by using naturally abundant resources and recyclable battery technology. Herein, we design a fully recyclable rechargeable sodium ion battery with bipolar electrode structure using Na3V2(PO4)3 as an electrode material and aluminum foil as the shared current collector. Such a design allows exceptional sodium ion battery performance in terms of high-power correspondence and long-term stability and enables the recycling of ∼100% Na3V2(PO4)3 and ∼99.1% elemental aluminum without the release of toxic wastes, resulting in a solid-component recycling efficiency of >98.0%. The successful incorporation of sustainability into battery design suggests that closed-loop recycling and the reutilization of battery materials can be achieved in next-generation energy storage technologies.

12.
Microorganisms ; 7(2)2019 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-30754647

RESUMO

Pennisetum sinese, a source of bio-energy with high biomass production, is a species that contains high crude protein and will be useful for solving the shortage of forage grass after the implementation of "Green for Grain" project in the Loess plateau of Northern Shaanxi in 1999. Plants may receive benefits from endophytic bacteria, such as the enhancement of plant growth or the reduction of plant stress. However, the composition of the endophytic bacterial community associated with the roots of P. sinese is poorly elucidated. In this study, P. sinese from five different samples (Shaanxi province, SX; Fujian province, FJ; the Xinjiang Uyghur autonomous prefecture, XJ and Inner Mongolia, including sand (NS) and saline-alkali land (NY), China) were investigated by high-throughput next-generation sequencing of the 16S rDNA V3-V4 hypervariable region of endophytic bacteria. A total of 313,044 effective sequences were obtained by sequencing five different samples, and 957 effective operational taxonomic units (OTUs) were yielded at 97% identity. The phylum Proteobacteria, the classes Gammaproteobacteria and Alphaproteobacteria, and the genera Pantoea, Pseudomonas, Burkholderia, Arthrobacter, Psychrobacter, and Neokomagataea were significantly dominant in the five samples. In addition, our results demonstrated that the Shaanxi province (SX) sample had the highest Shannon index values (3.795). We found that the SX (308.097) and NS (126.240) samples had the highest and lowest Chao1 richness estimator (Chao1) values, respectively. Venn graphs indicated that the five samples shared 39 common OTUs. Moreover, according to results of the canonical correlation analysis (CCA), soil total carbon, total nitrogen, effective phosphorus, and pH were the major contributing factors to the difference in the overall composition of the bacteria community in this study. Our data provide insights into the endophytic bacteria community composition and structure of roots associated with P. sinese. These results might be useful for growth promotion in different samples, and some of the strains may have the potential to improve plant production in future studies.

13.
Nat Commun ; 10(1): 328, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30644401

RESUMO

The original PDF version of this Article contained an error in Fig. 2, in which only the central part of the figure, between 'Mass loading' and 'Gravimetric performance', was visible. This has been corrected in the PDF version of the Article. The HTML version was correct from the time of publication.

14.
Nat Commun ; 9(1): 5262, 2018 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-30531912

RESUMO

Exceptional performance reported for battery materials and devices in the scientific literature is often measured under conditions that are not aligned with practical applications. Aiming to bridge the gap between academia and industry, this Comment advocates the best practices for gauging performance and proposes guidelines on measurements with respect to a list of key metrics such as capacity, cyclability, Coulombic efficiency and electrolyte consumption.

15.
Clin J Sport Med ; 2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-30371534

RESUMO

OBJECTIVE: Liver cancer is the second most common cause of death from cancer. Physical activity (PA) was found to be associated with lower risks of several types of cancer. However, the association between PA and the risk of liver cancer is still inconclusive. This systematic review and meta-analysis was aiming to summarize the association between PA and liver cancer risk. METHODS: Literatures related were identified by searching PubMed, EMBASE, and Chinese Biomedical literature database from 1965 to 2017 without language limitation. Meta-analyses were performed using random effect model. RESULTS: A total of 5 cohort studies involving 2 513 975 subjects were identified. The pooled relative risk of leisure-time PA with liver cancer risk was 0.92 [95% confidence interval (CI), 0.84-1.01]. There is no significant association between leisure-time PA and liver cancer risk. However, leisure-time PA significantly reduced liver cancer risk in never smokers. The pooled hazard ratio of daily total PA with liver cancer risk was 0.75 (95% CI, 0.66-0.86). CONCLUSIONS: Daily total PA significantly reduces liver cancer risk, whereas leisure-time PA significantly reduces liver cancer risk only in never smokers.

16.
ACS Appl Mater Interfaces ; 10(36): 30451-30459, 2018 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-30117730

RESUMO

Minimizing the shuttle effect of polysulfides (PS) is crucial for practical applications of lithium-sulfur (Li-S) batteries. However, the trade-off between effective suppression of the shuttle effect and fast redox reaction kinetics is inevitable for separator-based Li-S batteries. Herein, via a self-confined solid-conversion process, we develop a polystyrene sulfonate (PSS)-threaded well-intergrown HKUST-1 (Cu3(BTC)2) (BTC: 1,3,5-benzenetricarboxylic acid)-coated Celgard separator (PSS@HKUST-1/Celgard, PHC) for high-performance Li-S batteries. The PHC membrane favors the interception and accommodation of long-chain PS. Notably, enormous sulfonate groups of the three-dimensional PSS networks in PSS@HKUST-1 membrane significantly facilitate lithium-ion transport, which guarantee fast redox kinetics. The PHC separator demonstrates efficient inhibition of PS (i.e., 4 orders of magnitude lower in PS permeation rate) with fast Li+ transportation (i.e., 71% higher in ionic conductivity) than the Celgard separator. When applying the PHC membrane in Li-S batteries with conventional sulfur/super P carbon cathode, highly reversible capacity with an average fading rate of 0.05% per cycle is maintained for 500 cycles at 0.5 C, excellent rate performance up to 5 C, and high areal capacity over 7 mA h cm-2 are also achieved. This work paves a new way for addressing the trade-off between suppressing the PS shuttle effect and fast kinetic reaction for separator-based Li-S batteries.

17.
Chem Rev ; 118(18): 8936-8982, 2018 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-30133259

RESUMO

Tremendous efforts have been devoted to the development of electrode materials, electrolytes, and separators of energy-storage devices to address the fundamental needs of emerging technologies such as electric vehicles, artificial intelligence, and virtual reality. However, binders, as an important component of energy-storage devices, are yet to receive similar attention. Polyvinylidene fluoride (PVDF) has been the dominant binder in the battery industry for decades despite several well-recognized drawbacks, i.e., limited binding strength due to the lack of chemical bonds with electroactive materials, insufficient mechanical properties, and low electronic and lithium-ion conductivities. The limited binding function cannot meet inherent demands of emerging electrode materials with high capacities such as silicon anodes and sulfur cathodes. To address these concerns, in this review we divide the binding between active materials and binders into two major mechanisms: mechanical interlocking and interfacial binding forces. We review existing and emerging binders, binding technology used in energy-storage devices (including lithium-ion batteries, lithium-sulfur batteries, sodium-ion batteries, and supercapacitors), and state-of-the-art mechanical characterization and computational methods for binder research. Finally, we propose prospective next-generation binders for energy-storage devices from the molecular level to the macro level. Functional binders will play crucial roles in future high-performance energy-storage devices.

18.
ChemSusChem ; 11(9): 1479-1485, 2018 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-29575748

RESUMO

Exploring efficient and cheap oxygen evolution reaction (OER) electrocatalysts is of great significance for electrochemical water splitting. Herein, we successfully prepared an efficient ternary electrocatalyst of porous cobalt oxynitride (Co3 Ox Ny ) nanosheets by a simple nitridation strategy. Specifically, CoON PNS-400 (cobalt oxynitride with porous nanosheet structure obtained at 400 o C) offered a low OER overpotential of 0.23 V to achieve the catalytic current density of 10 mA cm-2 and a small Tafel slope of 48 mV dec-1 in alkali media, outperforming most of the first-row transition-metal-based OER electrocatalysts. The calculated density of states (DOS) analysis and electron spin resonance (ESR) measurements revealed that the introduction of foreign N atoms into pristine Co3 O4 nanosheets can optimize the electronic structure and create more oxygen vacancies, thus leading to enhanced electrical conductivity. Density functional theory (DFT) calculations demonstrated that the foreign N atoms can also improve the energetics for OER by modulating the free energy for adsorbed intermediates (OOH*, OH*, O*), further improving the OER electrocatalytic activity of CoON PNS-400. This work provides a possibility for rationally designing ternary transition-metal compounds as advanced OER electrocatalysts.

19.
Drug Deliv ; 25(1): 353-363, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29366349

RESUMO

Developing multifunctional nanoparticle-based theranostic platform for cancer diagnosis and treatment is highly desirable, however, most of the present theranostic platforms are fabricated via complicated structure/composition design and time-consuming synthesis procedures. Herein, the multifunctional Gd/CeO2-ZrO2/DOX-PEG nanoplatform with single nano-structure was fabricated through a facile route, which possessed MR/CT dual-model imaging and chemotherapy ability. The nanoplatform not only exhibited well-defined shapes, tunable compositions and narrow size distributions, but also presented a well anti-cancer effect and MR/CT imaging ability. Therefore, the Gd/CeO2-ZrO2/DOX-PEG nanoplatform could be applied for chemotherapy as well as dual-model MR/CT imaging.


Assuntos
Doxorrubicina/administração & dosagem , Doxorrubicina/química , Gadolínio/química , Nanopartículas/química , Zircônio/química , Animais , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/métodos , Feminino , Células Hep G2 , Humanos , Imagem por Ressonância Magnética/métodos , Camundongos Endogâmicos BALB C , Camundongos Nus , Tamanho da Partícula , Polietilenoglicóis/química , Tomografia Computadorizada por Raios X/métodos
20.
ACS Appl Mater Interfaces ; 9(44): 38159-38164, 2017 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-29053916

RESUMO

Silicon (Si) has aroused great interest as the most attractive anode candidate for energy-dense lithium-ion batteries (LIBs) in the past decade because of its significantly high capacity and low discharge potential. However, the large volume change during cycling impedes its practical application, which is more serious in the case of high mass loading. Designing Si anode with high mass loading and high areal capacity by a simple, scalable, and environmentally friendly method is still a big challenge. Herein, we report in situ one-pot synthesis of Si/C composite, where Si nanoparticles are wrapped by graphene-like 2D carbon nanosheets. After 500 cycles at 420 mA g-1, the Si/C anode displays a gravimetric capacity of 881 mAh g-1 with 86.4% capacity being retained. More specially, a high areal capacity of 3.13 mAh cm-2 at 5.00 mg cm-2 after 100 cycles is achieved. This study demonstrates a novel route for the preparation of the Si/C composite with high material utilization and may expand the possibility of future design Si-based anode with high areal capacity for high energy LIBs.

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