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1.
Proc Natl Acad Sci U S A ; 121(15): e2319525121, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38564637

RESUMO

The fine regulation of catalysts by the atomic-level removal of inactive atoms can promote the active site exposure for performance enhancement, whereas suffering from the difficulty in controllably removing atoms using current micro/nano-scale material fabrication technologies. Here, we developed a surface atom knockout method to promote the active site exposure in an alloy catalyst. Taking Cu3Pd alloy as an example, it refers to assemble a battery using Cu3Pd and Zn as cathode and anode, the charge process of which proceeds at about 1.1 V, equal to the theoretical potential difference between Cu2+/Cu and Zn2+/Zn, suggesting the electricity-driven dissolution of Cu atoms. The precise knockout of Cu atoms is confirmed by the linear relationship between the amount of the removed Cu atoms and the battery cumulative specific capacity, which is attributed to the inherent atom-electron-capacity correspondence. We observed the surface atom knockout process at different stages and studied the evolution of the chemical environment. The alloy catalyst achieves a higher current density for oxygen reduction reaction compared to the original alloy and Pt/C. This work provides an atomic fabrication method for material synthesis and regulation toward the wide applications in catalysis, energy, and others.

2.
Small ; 20(26): e2311205, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38267814

RESUMO

Urea, as one of the most sustainable organic solutes, denies the high salt consumption in commercial electrolytes with its peculiar solubility in water. The bi-mixture of urea-H2O shows the eutectic feature for increased attention in aqueous Zn-ion electrochemical energy storage (AZEES) technologies. While the state-of-the-art aqueous electrolyte recipes are still pursuing the high-concentrated salt dosage with limited urea adoption and single-anion selection category. Here, a dual-anion urea-based (DAU) electrolyte composed of dual-Zn salts and urea-H2O-induced solutions is reported, contributing to a stable electric double-layer construction and in situ organic/inorganic SEI formation. The optimized ZT2S0.5-20U electrolytes show a high initial Coulombic efficiency of 93.2% and durable Zn-ion storage ≈4000 h regarding Zn//Cu and Zn//Zn stripping/plating procedures. The assembled Zn//activated carbon full cells maintain ≈100% capacitance over 50 000 cycles at 4 A g-1 in coin cell and ≈98% capacitance over 20 000 cycles at 1 A g-1 in pouch cell setups. A 12 × 12 cm2 pouch cell assembly illustrates the practicality of AZEES devices by designing the cheap, antifreezing, and nonflammable DAU electrolyte system coupling proton donor-acceptor molecule and multi-anion selection criteria, exterminating the critical technical barriers in commercialization.

3.
Molecules ; 28(9)2023 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-37175232

RESUMO

α-Glucosidase (AGS) inhibitors have been regarded as an ideal target for the management of type 2 diabetes mellitus (T2DM) since they can maintain an acceptable blood glucose level by delaying the digestion of carbohydrates and diminishing the absorption of monosaccharides. In the process of our endeavor in mining AGS inhibitors from natural sources, the culture broth of two mangrove-derived actinomycetes Streptomyces sp. WHUA03267 and Streptomyces sp. WHUA03072 exhibited an apparent inhibitory activity against AGS. A subsequent chemical investigation into the two extracts furnished 28 secondary metabolites that were identified by spectroscopic methods as two previously undescribed linear polyketides 1-2, four benzenoid ansamycins 3-6, fourteen cyclodipeptides 7-18, one prenylated indole derivative 19, two fusicoccane-type diterpenoids 20-21, two hydroxamate siderophore 22-23, and five others 24-28. Among all of the isolates, 11 and 24 were obtained from actinomycetes for the first time, while 20-21 had never been reported to occur in a marine-derived microorganism previously. In the in vitro AGS inhibitory assay, compounds 3, 8, 9, 11, 14, 16, and 17 exhibited potent to moderate activity with IC50 values ranging from 35.76 ± 0.40 to 164.5 ± 15.5 µM, as compared with acarbose (IC50 = 422.3 ± 8.4 µM). The AGS inhibitory activity of 3, 9, 14, 16, and 17 was reported for the first time. In particular, autolytimycin (3) represented the first ansamycin derivative reported to possess the AGS inhibitory activity. Kinetics analysis and molecular docking were performed to determine the inhibition types and binding modes of these inhibitors, respectively. In the MTT assay, 3, 8, 9, 11, 14, 16, and 17 exhibited no apparent cytotoxicity to the human normal hepatocyte (LO2) cells, suggesting satisfactory safety of these AGS inhibitors.


Assuntos
Actinobacteria , Diabetes Mellitus Tipo 2 , Streptomyces , Humanos , Inibidores de Glicosídeo Hidrolases/química , Actinobacteria/metabolismo , Actinomyces/metabolismo , Simulação de Acoplamento Molecular , Streptomyces/metabolismo , alfa-Glucosidases/metabolismo , Estrutura Molecular
4.
Angew Chem Int Ed Engl ; 62(33): e202307475, 2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37318899

RESUMO

The brain-storm of designing low-cost and commercialized eutectic electrolytes for zinc (Zn)-based electrochemical energy storage (ZEES) remains unresolved and attractive, especially when implementing it at low temperatures. Here, we report an appealing layout of advancing chlorine-functionalized eutectic (Cl-FE) electrolytes via exploiting Cl anion-induced eutectic interaction with Zn acetate solutions. This novel eutectic liquid shows high affinity to collaborate with 1,3-dioxolane (DOL) and is prone to constitute Cl-FE/DOL-based electrolytes with a unique inner/outer eutectic solvation sheath for the better regulation of Zn-solvating neighboring and reconstruction of H-bonding. The side reactions are effectively restricted on Zn anodes and a high Coulombic efficiency of 99.5 % can be achieved over 1000 cycles at -20 °C with Zn//Cu setups. By prototyping scale-up Zn-ion pouch cells using the optimal eutectic liquid of 3ZnOAc1.2 Cl1.8 -DOL, we obtain improved electrochemical properties at -20 °C with a high capacitance of 203.9 F g-1 at 0.02 A g-1 in a range of 0.20-1.90 V and long-term cycling ability with 95.3 % capacitance retention at 0.2 A g-1 over 3,000 cycles. Overall, the proposal of ideal Cl-FE/DOL-based electrolytes guides the design of sub-zero and endurable aqueous ZEES devices and beyond.

5.
Small ; 18(21): e2200550, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35289487

RESUMO

Rechargeable zinc batteries (RZBs) have proved to be promising candidates as an alternative to lithium-ion batteries due to their low cost, inherent safety, and environmentally benign features. While designing cost-effective electrolyte systems with excellent compatibility with electrode materials, high energy/power density as well as long life-span challenge their further application as grid-scale energy storage devices. Eutectic electrolytes as a novel class of electrolytes have been extensively reported and explored taking advantage of their feasible preparation and high tunability. Recently, some perspectives have summarized the development and application of eutectic electrolytes in metal-based batteries, but their infancy requires further attention and discussion. This review systematically presents the fundamentals and definitions of eutectic electrolytes. Besides, a specific classification of eutectic electrolytes and their recent progress and performance on RZB fields are introduced as well. Significantly, the impacts of various composing eutectic systems are disserted for critical RZB chemistries including attractive features at electrolyte/electrode interfaces and ions/charges transport kinetics. The remaining challenges and proposed perspectives are ultimately induced, which deliver opportunities and offer practical guidance for the novel design of advanced eutectic electrolytes for superior RZB scenarios.

6.
Zhongguo Zhong Yao Za Zhi ; 47(2): 392-402, 2022 Jan.
Artigo em Zh | MEDLINE | ID: mdl-35178981

RESUMO

Obvious epigenetic differentiation occurred on Lycium barbarum in different cultivation areas in China. To investigate the difference and change rule of DNA methylation level and pattern of L. barbarum from different cultivation areas in China, the present study employed fluorescence-assisted methylation-sensitive amplified polymorphism(MSAP) to analyze the methylation level and polymorphism of 53 genomic DNA samples from Yinchuan Plain in Ningxia, Bayannur city in Inner Mongolia, Jingyuan county and Yumen city in Gansu, Delingha city in Qinghai, and Jinghe county in Xinjiang. The MSAP technical system suitable for the methylation analysis of L. barbarum genomic DNA was established and ten pairs of selective primers were selected. Among amplified 5'-CCGG-3' methylated sites, there were 35.85% full-methylated sites and 39.88% hemi-methylated sites, showing a high degree of epigenetic differentiation. Stoichiometric analysis showed that the ecological environment was the main factor affecting the epigenetic characteristics of L. barbarum, followed by cultivated varieties. Precipitation, air temperature, and soil pH were the main ecological factors affecting DNA methylation in different areas. This study provided a theoretical basis for the analysis of the epigenetic mechanism of L. barbarum to adapt to the diffe-rent ecological environments and research ideas for the introduction, cultivation, and germplasm traceability of L. barbarum.


Assuntos
Lycium , China , Metilação de DNA , Primers do DNA , Epigênese Genética , Lycium/genética
7.
J Chem Phys ; 154(18): 184501, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34241040

RESUMO

Deep eutectic solvents (DESs) and dilutions thereof (mainly in H2O but also in many other non-aqueous solvents and co-solvent mixtures) have recently attracted great attention. It is well known that DES dilutions exhibit deviations from ideality. Interestingly, the treatment of DES as a mixture of two components or a pseudo-component is by no means trivial when determining deviations in density and, mainly, in viscosity. Herein, we studied aqueous dilutions of one of the most widely studied DES, this is, that composed of choline chloride and urea in a 1:2 molar ratio (e.g., ChCl2U). Using density and viscosity data reported in previous works, we calculated the excess molar volumes (VE) and excess viscosities (ln ηE) considering ChCl2U as either a mixture of two components or a pseudo-component, that is, taking the DES molecular weight as MChCl2U = fChClMChCl + fUMU = 86.58 g mol-1 (with fChCl = 1/3 and fU = 2/3) or as M* ChCl2U = MChCl + 2 MU = 259.74 g mol-1. We found that neither the sign of VE and VE* nor their evolution with temperature was influenced by the use of either MChCl2U or M* ChCl2U, and only the absolute magnitude of the deviation and the DES content (in wt. %) at which the minimum appears exhibited some differences. However, ln ηE and ln ηE* exhibited opposite signs, negative and positive, respectively. The odd achievement of negative ln ηE in aqueous dilutions of ChCl2U characterized by the formation of HB networks suggest the treatment of ChCl2U as a pseudo-component as more appropriate. Moreover, the role played by the presence of U in the evolution of ln ηE* with temperature was also discussed.

8.
Environ Monit Assess ; 190(1): 15, 2017 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-29234976

RESUMO

Riverbed scour of bridge piers can cause rapid loss in foundation strength, leading to sudden bridge collapse. This study used multi-beam echo sounders (Seabat 7125) to map riverbed surrounding the foundations of four major bridges in the lower, middle, and upper reaches of the 700-km Yangtze River Estuary (YRE) during June 2015 and September 2016. The high-resolution data were utilized to analyze the morphology of the bridge scour and the deformation of the wide-area riverbed (i.e., 5-18 km long and 1.3-8.3 km wide). In addition, previous bathymetric measurements collected in 1998, 2009, and 2013 were used to determine riverbed erosion and deposition at the bridge reaches. Our study shows that the scour depth surrounding the bridge foundations progressed up to 4.4-19.0 m in the YRE. Over the past 5-15 years, the total channel erosion in some river reaches was up to 15-17 m, possessing a threat to the bridge safety in the YRE. Tide cycles seemed to have resulted in significant variation in the scour morphology in the lower and middle YRE. In the lower YRE, the riverbed morphology displayed one long erosional ditch on both sides of the bridge foundations and a long-strip siltation area distributed upstream and downstream of the bridge foundations; in the middle YRE, the riverbed morphology only showed erosional morphology surrounding the bridge foundations. Large dunes caused deep cuts and steeper contours in the bridge scour. Furthermore, this study demonstrates that the high-resolution grid model formed by point cloud data of multi-beam echo sounders can clearly display the morphology of the bridge scour in terms of wide areas and that the sonar technique is a very useful tool in the assessment of bridge scours.


Assuntos
Engenharia/métodos , Monitoramento Ambiental/métodos , Estuários , Sedimentos Geológicos/análise , Rios , Colapso Estrutural/prevenção & controle , China , Simulação por Computador , Materiais de Construção , Hidrodinâmica
9.
Zhongguo Zhong Yao Za Zhi ; 42(2): 264-273, 2017 Jan.
Artigo em Zh | MEDLINE | ID: mdl-28948729

RESUMO

To provide a scientific basis for the selection and optimization of the modern drying processing method for Angelicae Sinensis Radix (ASR). Three phenolic acids (esters), 6 phthalides were determined by using UPLC-PDA while polysaccharides were determined by UV-Vis spectrophotometry. Then the effects of drying methods on the inner qualities of ASR were evaluated through principle components analysis (PCA) combined with the appearance properties after drying. Results showed that the contents of chlorogenic acid and ferulic acid in samples obtained with controlled temperature and humidity drying (CTHD), medium and shortwave infrared drying (MSID) and microwave vacuum drying (MVD) methods were significantly higher than those with primary drying processing(PDP) method and the fresh samples. Multivariate statistical analysis showed that samples processed with CTHD had more similar general chemical properties with those processed with PDP, suggesting that CTHD was appropriate for the modern primary drying processing of ASR. With samples processed with traditional PDP method as reference, the CTHD method was further optimized in the processing parameters for ASR by orthogonal experiment design. Considering the consumption of drying power and time and other parameters, the modern drying parameters for the primary drying processing of ASR were finally optimized as follows: controlled temperature and humidity drying at 40-45 ℃, relative humidity below 25% and target moisture content about 50% in the first stage of drying process, tempering for 12-24 h, and then drying under the conditions of temperature at 50-60 ℃, relative humidity below 20% and fan frequency at 30-40 Hz in the second stage. The study provided the scientific evidence for the selection of appropriate drying method and suitable parameters for the modern primary drying processing of ASR, as well as the beneficial exploration and practice on the formation of technical standard of primary drying processing for roots and rhizomes types herbal medicines.


Assuntos
Angelica sinensis/química , Dessecação/métodos , Medicamentos de Ervas Chinesas/química , Raízes de Plantas/química , Plantas Medicinais/química , Análise de Componente Principal , Tecnologia Farmacêutica
10.
Zhong Yao Cai ; 39(7): 1509-15, 2016 Jul.
Artigo em Zh | MEDLINE | ID: mdl-30203946

RESUMO

Objective: To optimize the suitable drying processing methods of the root of Angelica dahurica by the appearance and the content of active compounds. Methods: 19 methods including natural drying in the shade, natural drying in the sun, hot air drying, shortwave infrared radiation drying were studied. HPLC-PDA method was adopted to determine the contents of coumarin compounds. GC-MS with internal standard method was used to determine the content of volatile oil. The appearance of samples was evaluated by the method of composite scores. Results: The results of coumarins contents showed that the natural drying in the sun was higher than natural drying in the shade, variable-temperature drying was the best, and the temperature of constant temperature drying was inversely proportional to the contents of coumarins. The results of volatile oils contents showed that variable-temperature drying was the best, and the temperature of constant temperature drying was inversely proportional to the contents of volatile oils. The results of composite scores showed that hot air drying in 50 ℃ was the best, followed by natural drying in the sun, natural drying in the shade and shortwave infrared radiation drying in 50 ℃. Conclusion: Therefore,considering the drying time,the appearance,and the content of active compounds,the hot air drying method and hot air machine with temperature and humidity controlled was recommend. The suitable parameters for the machine were that the drying temperature was 50 ℃,and the humidity was 35%. The method could provide the reference for the drying technology standard of roots such as Angelica dahurica.


Assuntos
Angelica , Dessecação , Cromatografia Líquida de Alta Pressão , Cumarínicos , Medicamentos de Ervas Chinesas , Cromatografia Gasosa-Espectrometria de Massas , Óleos Voláteis
11.
Zhongguo Zhong Yao Za Zhi ; 41(16): 3002-3008, 2016 Aug.
Artigo em Zh | MEDLINE | ID: mdl-28920339

RESUMO

To establish the suitable modern drying processing parameters for Scrophulariae Radix (SR). With reference to the traditional drying processing method of SR and the characteristics of modern drying equipment, the drying process for SR was simulated as the following three stages: temperature-controlled drying-tempering-temperature-controlled drying. Eighteen batches of SR samples were obtained by the drying methods after the orthogonal design experiment with seven factors namely temperature, wind speed, and target moisture for the first stage, tempering time and temperature, as well as temperature and wind speed for the second stage. UPLC-TQ-MS was applied for determination of nine target compounds including catalpol, harpagide, verbascoside, ferulic acid, angroside-C, aucubin, harpagoside, cinnamic acid and ursolic acid in those dried samples and another 19 batches of SR samples collected from genuine producing area. Principal Component Analysis (PCA) was performed, and total energy consumption was also taken into consideration for analysis and evaluation. Results showed that the optimal drying processing method for SR was as follows: drying temperature of 60 ℃, drying wind speed of 50 Hz, and 50% for target moisture in the first stage; 24 h for tempering time and temperature of 20 ℃ in the second stage; drying temperature of 60 ℃, and drying wind speed of 30 Hz in the third stage. The medicinal materials with optimized modern drying processing method were extremely similar to those collected from genuine producing area in the aspect of both external properties and target compounds, and they were in line with the 2015 version of "Chinese Pharmacopoeia" requirements. In addition, they could help to shorten the drying time and increase the efficiency of primary processing, and thus promote the normalization and standardization of primary drying processing for SR.


Assuntos
Dessecação/métodos , Medicamentos de Ervas Chinesas , Scrophularia , Análise Multivariada , Raízes de Plantas
12.
Zhongguo Zhong Yao Za Zhi ; 40(22): 4417-23, 2015 Nov.
Artigo em Zh | MEDLINE | ID: mdl-27097417

RESUMO

Modern drying technology was used to explore suitable drying process to provide scientific basis for improving drying processing methods of Scrophulariae Radix. Controlled temperature and humidity drying, vacuum drying apparatus, microwave vacuum drying apparatus, short infrared drying device were used to gain samples for analyzing. The character appearance, concentration of main components and power consumption indicators were chosen for preliminary judging. Six major components, including iridoids and phenylpropanoids were analyzed by UPLC-MS/MS method. The contents of polysaccharides were determined by UV-visible spectrophotometry. The character appearance with controlled temperature and humidity drying and short infrared drying meet the pharmacopoeia standard (Ch. p, edition 2015), while samples with vacuum and microwave vacuum drying apparatus didn't. Compared to fresh sample, concentrations of harpagide, harpagoside, aucubin and catalpol were lower in the dried samples. Angoroside-C showed no significant change before and after drying. Concentration of acteoside increased after drying. Samples with controlled temperature (70 degrees C) and humidity (15% - 10%) drying had high content and short drying time. The better drying process of Scrophulariae Radix was controlled temperature and humidity drying. The method will provide the reference for the drying technology standard of roots medicine.


Assuntos
Dessecação/métodos , Medicamentos de Ervas Chinesas/química , Scrophularia/química , Raízes de Plantas/química , Controle de Qualidade
13.
Zhongguo Zhong Yao Za Zhi ; 40(11): 2117-22, 2015 Jun.
Artigo em Zh | MEDLINE | ID: mdl-26552166

RESUMO

To establish the water dynamics model for drying process of Angelicae Sinensis Radix, the Weibull distribution model was applied to study the moisture ratio variation curves, and compared the drying rate and drying activation energy with the drying methods of temperature controllable air drying, infrared drying under different temperatures (50, 60, 70 degrees C). The Weibull distribution model could well describe the drying curves, for the moisture ratio vs. drying time profiled of the model showed high correlation (R2 = 0. 994-0. 999). The result proved that the drying process of Angelicae Sinensis Radix belonged to falling-rate drying period. For the drying process, the scale parameter (a) was related to the drying temperature, and decreased as the temperature increases. The shape parameter (ß) for the same drying method, drying temperature had little impact on the shape parameter. The moisture diffusion coefficient increase along with temperature increasing from 0.425 x 10(-9) m2 x s(-1) to 2.260 x 10(-9) m2 x s(-1). The activation energy for moisture diffusion was 68.82, 29.60 kJ x mol(-1) by temperature controllable air drying and infrared drying, respectively. Therefore, the Weibull distribution model can be used to predict the moisture removal of Angelicae Sinensis Radix in the drying process, which is great significance for the drying process of prediction, control and process optimization. The results provide the technical basis for the use of modern drying technology for industrial drying of Angelicae Sinensis Radix.


Assuntos
Angelica sinensis/química , Dessecação/métodos , Modelos Teóricos , Água
14.
Zhongguo Zhong Yao Za Zhi ; 40(24): 4860-7, 2015 Dec.
Artigo em Zh | MEDLINE | ID: mdl-27245035

RESUMO

To provide a scientific basis for the selection of the appropriate drying method for Mentha Haplocalyx Herba (MHH), determine 2 monoterpenes, 4 phenolic acids and 5 flavonoids in MHH by GC-MS and UPLC-TQ-MS methods, and investigate the effects of the drying methods on the changes in contents of these analytes. The qualities of products obtained with different drying methods were evaluated by the multivariate statistical method of Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Results showed that the drying methods had the greatest impact on menthol, caffeic acid, and rosemary acid, which were followed by chlorogenic acid and diosmetin-7-O-glucoside. The contents in these analytes processed with hot-air-drying method were higher than those with microwave-drying and infrared-drying methods at the same temperatures. The contents in these analytes processed under low temperature (40-45 °C) were higher than those under higher temperature (60-70 °C). Above all, the contents in phenolic acids processed with microwave fixation (exposed under microwave at 100 °C for several minutes) were obviously higher than those of not being processed, showing an inhibition of some enzymes in samples after fixation. The TOPSIS evaluation showed that the variable temperature drying method of 'Hot-Air 45-60 °C' was the most suitable approach for the primary drying processing of MHH. The results could provide the scientific basis for the selection of appropriate drying method for MHH, and helpful reference for the primary drying proces of herbs containing volatile chemical components.


Assuntos
Dessecação/métodos , Flavonoides/análise , Hidroxibenzoatos/análise , Mentha/química , Monoterpenos/análise
15.
Opt Express ; 22(21): 24970-6, 2014 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-25401530

RESUMO

In this paper, we analyze near-field vector components of a metallic circular disk array (MCDA) plasmonic optical antenna and their contribution to quantum dot infrared photodetector (QDIP) enhancement. The near-field vector components of the MCDA optical antenna and their distribution in the QD active region are simulated. The near-field overlap integral with the QD active region is calculated at different wavelengths and compared with the QDIP enhancement spectrum. The x-component (E(x)) of the near-field vector shows a larger intensity overlap integral and stronger correlation with the QDIP enhancement than E(z) and thus is determined to be the major near-field component to the QDIP enhancement.


Assuntos
Raios Infravermelhos , Óptica e Fotônica/instrumentação , Pontos Quânticos/química , Simulação por Computador , Eletricidade , Metais/química , Dispositivos Ópticos
16.
J Phys Condens Matter ; 36(20)2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38324913

RESUMO

A self-consistent quantum-kinetic model is developed for studying strong-field nonlinear electron transport interacting with force-driven phonons within a nanowire system. For this model, phonons can be dragged into motion through strong electron-phonon scattering by fast-moving electrons along the opposite direction of the DC electric field. Meanwhile, the DC-field induced charge current of electrons can be either enhanced or reduced by the same electron-phonon scattering, depending on the relative direction of a DC field with respect to that of an applied temperature gradient for driving phonons. By making use of this quantum-kinetic model beyond the relaxation-time approximation, neither electron nor phonon temperature is required for describing ultrafast electron-phonon scattering and their correlated transports in this 1D electronic-lattice system.

17.
Fitoterapia ; 170: 105662, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37648028

RESUMO

Two new terrein derivatives asperterreinones A-B (1-2), one new octahydrocoumarin derivative (±)-asperterreinin A (6), along with seventeen known compounds, were isolated from Aspergillus terreus F6-3, a marine fungus associated with Johnius belengerii. The structures of 1, 2, and 6 were established on the basis of 1D and 2D NMR, mass spectroscopy, comparative electronic circular dichroism (ECD) spectra analysis, density functional theory calculation of 13C NMR, and DP4+ probability analysis. Among all the isolates, eurylene (7), a constituent of the Malaysian medicinal plant Eurycoma longifolia, was obtained from a microbial source for first time. In the in vitro bioassay, 11 and 13 showed potent inhibitory activity against the Escherichia coli ß-glucuronidase (EcGUS) with IC50 values of 27.75 ± 0.73 and 17.73 ± 0.81 µM, respectively. It was the first time that questinol (11) and (±)-aspertertone B (13) were reported as potent EcGUS inhibitors.


Assuntos
Aspergillus , Estrutura Molecular , Aspergillus/química , Espectrometria de Massas , Espectroscopia de Ressonância Magnética
18.
iScience ; 26(12): 108470, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38077143

RESUMO

Sodium-ion batteries (SIBs) with abundant resource and high safety are attracting intensive interest from both research and industry communities in meeting the ever-increasing energy demands. Despite the rapid advance of SIBs, it is difficult yet necessary to enhance the cycling and rate performance at anode due to the sluggish kinetics of "fat" Na+. This review provides an overview of two-dimensional (2D) nanomaterials with a short ion diffusion pathway and a superior active sites exposure from the perspectives of synthesis, material chemistry, and structure engineering. We present the design principle of ideal carbon materials in SIBs. Moreover, we discuss the structure and chemistry regulations of different 2D materials to promote the efficient ion mass transfer and storage according to the different mechanisms of alloying, conversion, and insertion. Finally, we propose the remaining challenges and the possible solutions, in hope of guiding the future development of this booming field.

19.
ACS Nano ; 17(23): 24012-24021, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38019270

RESUMO

Sodium-ion batteries (SIBs) are attracting worldwide attention due to their multiple merits including abundant reserve and safety. However, industrialization is challenged by the scarcity of high-performance carbon anodes with high specific capacities. Here, we report the metal-assisted microcrystalline structure regulation of carbon materials to achieve high-capacity sodium storage. Systematic investigations of in situ thermal-treatment X-ray diffraction and multiple spectroscopies uncover the regulation mechanism of constructing steric hindrance (C-O-C bonds) to restrain the aromatic polycondensation reaction. The carbon precursor of polycyclic aromatic hydrocarbon-type pitch contributes to a high carbon yield rate (40%) compared with those of resin and biomass precursors. The as-synthesized carbon materials deliver high capacities of up to 390 mAh g-1, surpassing many reported carbon anodes for SIBs. Through correlating specific capacity with ID/IG values in Raman spectra and theoretical calculation of carbon materials regulated by different metal elements (Mn, Nb, Ce, Cr, and V), we identify and propose the binding energy as the descriptor for characterizing the capability of regulating the carbon microcrystalline structure to promote sodium storage. This work provides a universal method for regulating the carbon structure, which may lead to the controlled design and fabrication of carbon materials for energy storage and conversion and beyond.

20.
ACS Appl Mater Interfaces ; 12(26): 29181-29193, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32484323

RESUMO

Water-in-salt (WIS) electrolytes are gaining increased interest as an alternative to conventional aqueous or organic ones. WIS electrolytes offer an interesting combination of safety, thanks to their aqueous character, and extended electrochemical stability window, thanks to the strong coordination between water molecules and ion salt. Nonetheless, cost, the tendency of salt precipitation, and sluggish ionic transfer leading to poor rate performance of devices are some intrinsic drawbacks of WIS electrolytes that yet need to be addressed for their technological implementation. It is worth noting that the absence of "free'' water molecules could also be achieved via the addition of a certain cosolvent capable of coordinating with water. This is the case of the eutectic mixture formed between DMSO and H2O with a molar ratio of 1:2 and a melting point as low as -140 °C. Interestingly, addition of salts at near-saturation conditions also resulted in an increase of the boiling point of the resulting solution. Herein, we used a eutectic mixture of DMSO and H2O for dissolution of LiTFSI in the 1.1-8.8 molality range. The resulting electrolyte (e.g., the so-called aqueous-eutectic-in-salt) exhibited excellent energy and power densities when operating in a supercapacitor cell over a wide range of extreme ambient temperatures, from as low as -35 °C to as high as +65 °C.

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