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1.
Angew Chem Int Ed Engl ; : e202406065, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38802982

RESUMO

The catalytic process of Li2S formation is considered a key pathway to enhance the kinetics of lithium-sulfur batteries. Due to the system's complexity, the catalytic behavior is uncertain, posing significant challenges for predicting activity. Herein, we report a novel cascaded dual-cavity nanoreactor (NiCo-B) by controlling reaction kinetics, providing an opportunity for achieving hierarchical catalytic behavior. Through experimental and theoretical analysis, the multilevel structure can effectively suppress polysulfides dissolution and accelerate sulfur conversion. Furthermore, we differentiate the adsorption (B-S) and catalytic effect (Co-S) in NiCo-B, avoiding catalyst deactivation caused by excessive adsorption. As a result, the as-prepared battery displays high reversible capacity, even with sulfur loading of 13.2 mg cm-2 (E/S=4 µl mg-1), the areal capacity can reach 18.7 mAh cm-2.

2.
Angew Chem Int Ed Engl ; 60(28): 15381-15389, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-33739572

RESUMO

For advanced anode materials involving alloy/de-alloy chemistry for potassium ion batteries (PIBs), two-dimensional (2D) bismuth subcarbonate (BCO) nanosheets that possess high theoretical capacity of 631 mAh g-1 are proposed. The large lattice spacing of 0.683 nm along b axis facilitate insertion of K+ ion to boost high-capacity delivery of ca. 610 mAh g-1 , and the in situ nano-crystallization well ease volume changes of the integrated particle and shorten ion diffusion path during potassiation/depotassiation. After coupling with a concentrated KFSI-G2 electrolyte, the robust and efficient SEI built from enhanced participation of FSI- synergistically endow structural stability of the flower-like BCO, and enable a prolonged cycling performance with capacity of ca. 300 mAh g-1 at 0.2 A g-1 for 1500 cycles, achieving an ultralow decay rate of 0.007 %. Mechanistic investigations probe the electrochemistry involving alloy/de-alloy and phase transition of the electrode.

3.
J Sep Sci ; 40(17): 3440-3452, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28683180

RESUMO

As a traditional medicinal plant, Juglans mandshurica has been used for the treatment of cancer. Different organs of this plant showed anti-tumor activity in clinic and laboratory. Comparative identification of constituents in different plant organs is essential for investigation of the relationship between chemical constituents and pharmacological activities. For this aim, the roots, branches, and leaves of J. mandshurica were extracted with 50% v/v methanol and then subjected to ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry analysis conducted under low and high energy. As a result, we have to date identified 111 compounds consisting of 56 tannins, 29 flavonoids, 13 organic acids, 8 naphthalene derivatives, and 5 anthracenes. Five compounds, namely, diquercetin trihydroxy-truxinoyl-glucoside, two quercetin kaempferol dihydroxy-truxinoyl-glucosides, syringoyl-tri-galloyl-O-glucose, and dihydroxy-naphthalene syringoyl-glucoside, were tentatively identified as new compounds. Of the compounds identified, 76 were found in the root extract, 67 in the branch extract, and 37 in the leaf extract. Only six compounds including four organic acids and two tannins were found in all three extracts. We developed a rapid and sensitive ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry approach to identify multiple constituents of complex extracts without separation and ion selection. The results presented provide useful information on further research of the bioactive compounds of J. mandshurica.


Assuntos
Juglans/química , Compostos Fitoquímicos/análise , Extratos Vegetais/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Folhas de Planta/química , Raízes de Plantas/química
4.
Molecules ; 22(9)2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28862686

RESUMO

As a folk medicinal plant, Juglans mandshurica has been used for the treatment of cancer in China and Korea. Traditionally, J. mandshurica is decocted together with chicken eggs. Both the decoction and medicated eggs possess anti-tumor properties. Clarifying the constituents of the decoction and absorbed by the medicated eggs is essential for the investigation of the active principles of J. mandshurica. Herein, the medicated eggs were prepared by decocting raw chicken eggs, having unbroken shells, with the decoction of J. mandshurica. A systematic investigation of the chemical profile of the J. mandshurica decoction and the medicated egg extraction was conducted by HPLC-Q-TOF-MS². In total, 93 peaks, including 45 tannins, 14 naphthalene derivatives, 17 organic acids, 3 diarylheptanoids, 4 lignans, 3 anthraquinones, 1 flavonoid glycoside, 3 amino acids, and 3 nitrogenous compounds, were tentatively identified in the decoction. In the medicated egg extraction, 44 peaks including 11 organic acids, 3 amino acids, 3 nitrogenous compounds, 8 naphthalene derivatives, 3 diarylheptanoids, 15 tannins, and 1 lignan were tentatively identified. The chemical profile presented provided a detailed overview of the polar chemical constituents in J. mandshurica and useful information for the research of bioactive compounds of this plant.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Juglans/química , Óvulo/química , Animais , Galinhas , Espectrometria de Massas
5.
BMC Complement Altern Med ; 14: 89, 2014 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-24602493

RESUMO

BACKGROUND: Berberine is an isoquinoline alkaloid mainly extracted from Rhizoma Coptidis and has been shown to possess a potent inhibitory activity against bacterial. However, the role of berberine in anti-bacterial action has not been extensively studied. METHODS: The animal model was established to investigate the effects of berberine on bacterial and LPS infection. Docking analysis, Molecular dynamics simulations and Real-time RT-PCR analysis was adopted to investigate the molecular mechanism. RESULTS: Treatment with 40 mg/kg berberine significantly increased the survival rate of mice challenged with Salmonella typhimurium (LT2), but berberine show no effects in bacteriostasis. Further study indicated that treatment with 0.20 g/kg berberine markedly increased the survival rate of mice challenged with 2 EU/ml bacterial endotoxin (LPS) and postpone the death time of the dead mice. Moreover, pretreatment with 0.05 g/kg berberine significantly lower the increasing temperature of rabbits challenged with LPS. The studies of molecular mechanism demonstrated that Berberine was able to bind to the TLR4/MD-2 receptor, and presented higher affinity in comparison with LPS. Furthermore, berberine could significantly suppressed the increasing expression of NF-κB, IL-6, TNFα, and IFNß in the RAW264.7 challenged with LPS. CONCLUSION: Berberine can act as a LPS antagonist and block the LPS/TLR4 signaling from the sourse, resulting in the anti-bacterial action.


Assuntos
Antibacterianos/farmacologia , Berberina/farmacologia , Lipopolissacarídeos/antagonistas & inibidores , Antígeno 96 de Linfócito/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Antibacterianos/química , Antibacterianos/metabolismo , Berberina/química , Berberina/metabolismo , Temperatura Corporal/efeitos dos fármacos , Linhagem Celular , Citocinas/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Simulação de Dinâmica Molecular , Coelhos , Infecções por Salmonella/tratamento farmacológico , Salmonella typhimurium/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
6.
Zhong Yao Cai ; 37(2): 324-7, 2014 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-25095357

RESUMO

OBJECTIVE: To analyze and optimize extraction technics of Polygonum orientale flowers by response surface methodology. METHODS: With the index for the content of taxifolin in flowers of Polygonum orientale, the effect of three factors such as concentration of alcohol, extraction time and solvent-solid ratio was designed by Box-Behnken central composite. Extraction technic parameters of Polygonum orientale flowers was optimized by response surface methodology. RESULTS: The optimizing extraction conditions of Polygonum orientale flowers were as follows: ethanol concentration was 65%, extracting time was 129 min and solvent-solid ratio was 18. Under the conditions, the average yield of taxifolin in 3 validation experiments was 2.79 mg/g. CONCLUSION: Optimizing extraction technics by response surface methodology is reasonable, simple, and has good predictability.


Assuntos
Medicamentos de Ervas Chinesas/isolamento & purificação , Flores/química , Plantas Medicinais/química , Polygonum/química , Tecnologia Farmacêutica/métodos , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/química , Etanol/química , Modelos Lineares , Quercetina/análogos & derivados , Quercetina/análise , Fatores de Tempo
7.
Zhong Yao Cai ; 36(4): 557-61, 2013 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-24134000

RESUMO

OBJECTIVE: To establish an identification method of Cudrania tricuspidata and Cudrania cochinchinensis, and their medicinal parts, and analyse the species of commercial drug Cudraniae Tricuspidatae Radix et Caulis. METHODS: TLC and First-order Derivative UV Spectrophotometry were used. RESULTS: Commercial drugs 5, 6, 7 and 9 belonged to the stem of Cudrania cochinchinensis, commercial drug 1, 2, 3 ,4 and 8 were neither Cudrania tricuspidata nor Cudrania cochinchinensis. CONCLUSION: Cudrania tricuspidata and Cudrania cochinchinensis can be identified by TLC, as well as the medicinal parts. UV Spectrophotometry can't be applied to variety identification but can be used for identifying the medicinal parts. It's more accurate and reliable for identifying Cudrania tricuspidata and Cudrania cochinchinensis, and the medicinal parts by combined using TLC and UV. This study provides a scientific and effective method for species identification and medicinal part analysis of commercial drug Cudraniae Tricuspidatae Radix et Caulis.


Assuntos
Medicamentos de Ervas Chinesas/análise , Moraceae/química , Moraceae/classificação , Cromatografia em Camada Fina , Medicamentos de Ervas Chinesas/química , Raízes de Plantas/química , Caules de Planta/química , Controle de Qualidade , Solventes/química , Espectrofotometria Ultravioleta
8.
Zhongguo Zhong Yao Za Zhi ; 38(2): 167-70, 2013 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-23672035

RESUMO

OBJECTIVE: To establish a HPLC-DAD method for the determination of axifolin, naringenin, quercetin and kaempferol in Cudrania tricuspidata and C. cochinchinensis in order to provide a scientific reference for species identification and quality evaluation, by establishing. METHOD: The determination was performed by HPLC-DAD on an Agilent C18 column (4.6 mm x 150 mm, 5 microm) by gradient elution (0-15 min, 35%-50% A; 15-30 min, 50% - 65% A) using methanol (A) and 0.1% phosphoric acid (B) as the mobile phase. The flow rate was 1 mL x min(-1). The detection wavelength was 290 nm for taxifolin and naringenin, 365 nm for quercetin and kaempferol with column temperature at 30 degrees C. RESULT: The content of axifolin and quercetin in the root of C. tricuspidata were remarkably higher than that in the root of C. cochinchinensis, and the content in stem of C. tricuspidata was also higher than that in the stem of C. cochinchinensis, the content of axifolin and quercetin was variable in different species. The content of naringenin and kaempferol in the root of C. cochinchinensis was visibly higher than that in the root of C. tricuspidata, and the content in the stems of the two herbs was similar, the content of naringenin and kaempferol was visibly variable in different medicinal parts of the herb, but similar between the two herbs. CONCLUSION: There's some difference of the content of the four ingredients in different medicinal parts and different herbs, so clinical use should not be confused.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/isolamento & purificação , Flavonas/isolamento & purificação , Moraceae/química , Medicamentos de Ervas Chinesas/química , Flavanonas/química , Flavanonas/isolamento & purificação , Flavonas/química , Quempferóis/química , Quempferóis/isolamento & purificação , Metanol , Especificidade de Órgãos , Ácidos Fosfóricos , Raízes de Plantas/química , Caules de Planta/química , Plantas Medicinais , Quercetina/análogos & derivados , Quercetina/química , Quercetina/isolamento & purificação , Reprodutibilidade dos Testes , Especificidade da Espécie
9.
Zhongguo Zhong Yao Za Zhi ; 38(17): 2779-81, 2013 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-24380297

RESUMO

OBJECTIVE: To find out the correlation between the content of taxifolin in Polygonum orientale and the storage time. METHOD: HPLC was used to determine taxifolin. The chromatographic condition was as following: Diamonsil C18 column (4.6 mm x 200 mm, 5 microm), mobile phase acetonitrile -0.1% phosphoric acid (gradient elution), the detection wavelength 290 nm and flow rate 1.0 mL x min(-1), the column temperature 30 degrees C. RESULT: The injection volume of taxifolin was in good linearity within 0.07 and 0.35 microg, the average recovery was 99.7% with RSD 0.2%. Taxifolin content was 0.84, 1.36, 1.75, 1.99 mg x g(-1) corresponding to storage time of 10, 7, 6, 5 years, respectively. CONCLUSION: The content of taxifolin decreased with the storage time. When the storage period is more than six years, the content is lower than that required by Chinese Pharmacopoeia (2010 version). This method has a good repeatability and accuracy, it provides a scientific reference for clinical use and quality evaluation of P. orientale.


Assuntos
Armazenamento de Medicamentos/métodos , Medicamentos de Ervas Chinesas/análise , Polygonum/química , Quercetina/análogos & derivados , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Quercetina/análise
10.
Zhong Yao Cai ; 36(12): 1937-9, 2013 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-25090675

RESUMO

OBJECTIVE: To establish a characteristic HPLC fingerprint of Polygonum orientale inflorescence, and to provide reference for its quality evaluation. METHODS: Taxifolin was used as reference. HPLC analysis was carried out with Diamonsil C18 column (200 mm x 4.6 mm, 5 microm) using acetonitrile -0.1% phosphoric acid(gradient elution)as mobile phase at flow rate of 1.0 mL/min. The detection wavelength was set at 280 nm and the column temperature was 30 degrees C. RESULTS: Eighteen common peaks were pointed out from the HPLC fingerprint of Polygonum orientale inflorescence from 12 different habitats. Among of them,four common peaks were identified as taxifolin, catechin, gallic acid and 3,3'-dimethyl ellagic acid-4-O-beta-D-glucoside. Analyzed by "Similarity Evaluation for Chromatographic Fingerprint of Traditional Chinese Medicine" software, the HPLC fingerprint similarities of 12 samples were more than 0.9. CONCLUSION: This method is repeatable and exclusive. It can be used for identification and quality control of Polygonum orientale inflorescence.


Assuntos
Medicamentos de Ervas Chinesas/química , Flores/química , Plantas Medicinais/química , Polygonum/química , Cromatografia Líquida de Alta Pressão , Polygonum/crescimento & desenvolvimento , Controle de Qualidade , Quercetina/análogos & derivados , Quercetina/análise , Reprodutibilidade dos Testes
11.
J Colloid Interface Sci ; 647: 306-317, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37262993

RESUMO

Emerging aqueous zinc-ion hybrid capacitors (AZICs) are considered a promising energy storage because of their superior electrochemical performance. The pore structure, suitable heteroatom content, and graphitization degree (GD) of carbon-based cathodes significantly influence the electrochemical performance of AZICs. The N, S dual-doped porous graphitic carbon materials (LC-750) with the combined characteristics of high GD (1.11) and large specific surface area (1678.38 m2 g-1) are successfully developed by a facile "killing two birds with one stone" strategy using K3Fe(C2O4)3·3H2O as the activating and graphitizing agent, and waste sponge (WS) and coal tar pitch (CTP) as the heteroatom and carbon resource, respectively. Results show that the LC-750 cathode displays high capacities of 185.3 and 95.2 mAh g-1 at 0.2 and 10 A g-1. Specifically, the assembled LC-750//Zn capacitor can offer a maximal energy density of 119.5 Wh kg-1, a power density of 20.3 kW kg-1, and a capacity retention of 87.8% after 15,000 cycles at 10 A g-1. Density functional theory simulations demonstrate that N and S dual-doping can promote the adsorption kinetics of Zn ions. This design strategy is a feasible and cost-effective method for the preparation of dual heteroatom-doped graphitic carbon electrodes, which enables recycling of WS and CTP into high-valued products.

12.
J Phys Chem A ; 116(45): 10904-16, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23057557

RESUMO

This paper introduces a new approach called double asynchronous orthogonal sample design (DAOSD) to probe intermolecular interactions. A specifically designed concentration series is selected according to the mathematical analysis to generate useful 2D correlated spectra. As a result, the interfering portions are completely removed and a pair of complementary sub-2D asynchronous spectra can be obtained. A computer simulation is applied on a model system with two solutes to study the spectral behavior of cross peaks in 2D asynchronous spectra generated by using the DAOSD approach. Variations on different spectral parameters, such as peak position, bandwidth, and absorptivity, caused by intermolecular interactions can be estimated by the characteristic spectral patterns of cross peaks in the pair of complementary sub-2D asynchronous spectra. Intermolecular interactions between benzene and iodine in CCl(4) solutions were investigated using the DAOSD approach to prove the applicability of the DAOSD method in real chemical system.


Assuntos
Simulação por Computador , Benzeno/química , Tetracloreto de Carbono/química , Iodo/química , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(7): 1790-4, 2012 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-23016326

RESUMO

In situ TLC/FTIR technique has tremendous potential in the analysis of complex mixtures. However, the progress in this technique was quite slow. The reason is that conventional stationary phase has strong absorption in FTIR spectrum and thus brings about severe interference in the detection of samples. To solve the problem, the authors propose to use AgI fine particles as stationary phase of TLC plate. The reasons are as follows: Silver iodide fine particles have no absorbance in an IR region between 4 000 and 800 cm(-1), therefore, the interference caused by IR absorption of stationary phase can be removed. Moreover, silver iodide is stable and insolvable in water and organic solvents and thus it will not be destroyed by mobile phase or react with samples during the TLC separation. To improve TLC separation efficiency and quality of FTIR spectra during the TLC/FTIR analysis, the size of AgI particles should be below 500 nm. We used orthogonal design approach to optimize the experimental condition to AgI particles so that the average size of AgI particles is around 100 nm. No absorption of impurity or adsorbed water were observed in FTIR spectrum of the AgI particles the authors used "settlement volatilization method" to prepare TLC plate without using polymeric adhesive that may bring about significant interference in FTIR analysis. Preliminary TLC experiments proved that the TLC plate using AgI fine particles as stationary phase can separate mixtures of rhodamine B and bromophenol blue successfully. Applications of silver iodide fine particles as stationary phase have bright perspective in the development of in-situ TLC/FTIR analysis techniques.

14.
Zhong Yao Cai ; 35(4): 540-2, 2012 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-23019898

RESUMO

OBJECTIVE: To study the effects of different processing on taxifolin and quercetin in Fructus Polygoni Orientalis. METHODS: The analysis was performed on a Agilent column (4. 6 mm x 150 mm, 5 microm) eluted with a gradient elution of methanol-water containing 0. 1% phosphoric acid. The flow rate was 1 mL/min, the detection wave length was 270 nm and the column temperature was set at 25 degrees C. The content changes of taxifolin and quercetin processed by different methods was compared. RESULTS: The contents of active ingredients in Fructus Polygoni Orientalis that processed by the method of therm-high pressure (the pressure was 14Pa) was obvious higher than those of other methods. CONCLUSION: Active ingredients of Fructus Polygoni Orientalis may be promoted by therm-high pressure processed. There is significant difference for the major components by different processing methods. The method of therm-high pressure to processing is used for the first time in the Fruit Polygoni Orientalis. The method appears to be simple, easy and can be used as quantitative determination method for quality control of the Fructus Polygoni Orientalis.


Assuntos
Medicamentos de Ervas Chinesas/química , Polygonaceae/química , Quercetina/análogos & derivados , Quercetina/análise , Tecnologia Farmacêutica/métodos , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/isolamento & purificação , Frutas/química , Temperatura Alta , Plantas Medicinais/química , Pressão , Controle de Qualidade , Reprodutibilidade dos Testes
15.
Nanomaterials (Basel) ; 12(4)2022 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-35215028

RESUMO

Tin dioxide (SnO2) has been the focus of attention in recent years owing to its high theoretical capacity (1494 mAh g-1). However, the application of SnO2 has been greatly restricted because of the huge volume change during charge/discharge process and poor electrical conductivity. In this paper, a composite material composed of SnO2 and S, N co-doped carbon (SnO2@SNC) was prepared by a simple solid-state reaction. The as-prepared SnO2@SNC composite structures show enhanced lithium storage capacity as compared to pristine SnO2. Even after cycling for 1000 times, the as-synthesized SnO2@SNC can still deliver a discharge capacity of 600 mAh g-1 (current density: 2 A g-1). The improved electrochemical performance could be attributed to the enhanced electric conductivity of the electrode. The introduction of carbon could effectively improve the reversibility of the reaction, which will suppress the capacity fading resulting from the conversion process.

16.
ACS Appl Mater Interfaces ; 14(13): 15324-15336, 2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35315652

RESUMO

Metal sulfides are promising anodes for potassium-ion batteries (PIBs) due to their high theoretical capacity and abundant active sites; however, their intrinsic low conductivity and poor cycling stability hampered their practical applications. Given this, the rational design of hybrid structures with high stability and fast charge transfer is a critical approach. Herein, CoS2/ZnS@rGO hybrid nanocomposites were demonstrated with stable cubic phases. The synergistic effect of the obtained bimetallic sulfide nanoparticles and highly conductive 2D rGO nanosheets facilitated excellent long-term cyclability for potassium ion storage. Such hybrid nanocomposites delivered remarkable ultrastable cycling performances in PIBs of 159, 106, and 80 mA h g-1 at 1, 1.5, and 2 A g-1 after 1800, 2100, and 3000 cycles, respectively. Moreover, the full-cell configuration with a perylene tetracarboxylic dianhydride organic cathode (CoS2/ZnS@rGO∥PTCDA) exhibited a better electrochemical performance. Besides, when the CoS2/ZnS@rGO nanocomposites were applied as an anode for sodium-ion batteries, the electrode demonstrated a reversible charge capacity of 259 mA h g-1 after 600 cycles at 2 A g-1. In situ X-ray diffraction and ex situ high-resolution transmission electron microscopy characterizations further confirmed the conversion reactions of CoS2/ZnS during insertion/desertion processes. Our synthesis strategy is also a general route to other bimetallic sulfide hybrid nanocomposites. This strategy opens up a new roadmap for exploring hybrid nanocomposites with feasible phase engineering for achieving excellent electrochemical performances in energy storage applications.

17.
Adv Mater ; 34(50): e2204403, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36208086

RESUMO

Developing a conductive catalyst with high catalytic activity is considered to be an effective strategy for improving cathode kinetics of lithium-sulfur batteries, especially at large current density and with lean electrolytes. Lattice-strain engineering has been a strategy to tune the local structure of catalysts and to help understand the structure-activity relationship between strain and catalyst performance. Here, Co0.9 Zn0.1 Te2 @NC is constructed after zinc atoms are uniformly doped into the CoTe2 lattice. The experimental/theoretical results indicate that a change of the coordination environment for the cobalt atom by the lattice strain modulates the d-band center with more electrons occupied in antibonding orbitals, thus balancing the adsorption of polysulfides and the intrinsic catalytic effect, thereby activating the intrinsic activity of the catalyst. Benefiting from the merits, with only 4 wt% dosages of catalyst in the cathode, an initial discharge capacity of 1030 mAh g-1 can be achieved at 1 C and stable cycling performances are achieved for 1500/2500 cycles at 1 C/2 C. Upon sulfur loading of 7.7 mg cm-2 , the areal capacity can reach 12.8 mAh cm-2 . This work provides a guiding methodology for the design of catalytic materials and refinement of adsorption-catalysis strategies for the rational design of cathode in lithium-sulfur batteries.

18.
Zhongguo Zhong Yao Za Zhi ; 36(1): 32-6, 2011 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-21473148

RESUMO

The roots, barks, branches and pericarps of Juglans mandshurica were used as folk medicine in China and reputed for its treatment of several cancers, such as gastric cancer, liver cancer and leukemia. The extracts of the roots, branches, leaves and pericarps of J. mandshurica have been experimentally proved to show anti-tumor activities. Tannins, which exhibited antioxidant and anti-tumor activities, were the main constituents in J. mandshurica. In this paper, a simple spectrophotometric method was developed for the determination of total tannins in the roots, branches, leaves and pericarps of J. mandshurica collected in Dalian and Anshan of Liaoning Province. Gallic acid was used as standard compound and the content of total tannins was calculated as gallic acid equivalent. As a result of the method validation, a good linearity (r = 0.9997, n = 5) and a high recovery of gallic acid (99.02%, RSD 3.7%, n = 9) was achieved. Eight samples including four parts of J. mandshurica collected in two places were analyzed for their total tannins with the established method. In the corresponding parts of J. mandshurica, except the pericarps, the contents of total tannins showed no significant difference between samples collected in Dalian and Anshan, while the content of total tannins in different parts of J. mandshurica were significantly different. The average content of total tannins in the roots, branches, leaves and pericarps of samples collected in Dalian and Anshan was 45.66, 23.40, 58.24, 3.58 mg g(-1), respectively.


Assuntos
Juglans/química , Extratos Vegetais/análise , Taninos/análise , Folhas de Planta/química , Raízes de Plantas/química , Caules de Planta/química
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(10): 2706-9, 2010 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-21137404

RESUMO

Gels are gaining extensive interest owing to their versatile applications in fields such as drug delivery, tissue engineering, cosmetics, templated materials and food industry. Surfactants have an ability to self-assemble into a variety of supramolecular aggregate structures and morphologies. Of particular interest in resent years are surfactant-based gels, one special class of materials due to surfactant assemblies resulting in viscoelastic solid-like rheological behaviors. Up to now, there is only limited understanding on the mechanism of gel formation, especially on the interaction among water, organic solvents and surfactant during thegel formation. In this study we prepare a Low-molecule-gel that is composed of cetyl trimethyl ammonium bromide (CTAB), water and carbon tetrachloride. Based on the experimental result of XRD and titration, the authors find that CTAB in gel are more than in saturated CTAB solution but CTAB is not solide in gel. CTAB is not solvented in CCl4. The solubility of CTAB in saturated CTAB solution is limited. So the authors suppose that CTAB is a synergistically solubilized by water and CCl4 in the gel. In addition, both NMR and FTIR spectroscopic results demonstrate that CTAB cations form a quasi-ordered structure in the gel.


Assuntos
Tetracloreto de Carbono , Compostos de Amônio Quaternário , Tensoativos , Água , Cátions , Géis , Micelas , Solubilidade , Soluções , Solventes
20.
Zhongguo Zhong Yao Za Zhi ; 35(3): 272-4, 2010 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-20422986

RESUMO

OBJECTIVE: To establish a method for the content determination of paprazine in Polygonum orientale, and provide a new evaluation index for the quality control for P. orientale. METHOD: HPLC was carried out on Agilent C18 (4.6 mm x 150 mm, 5 microm) with methanol-water (40:60) as mobile phase. The flow rate was 1.0 mL x min(-1) and the wavelength of UV detector was set at 290 nm. RESULT: The calibration curve was linear in the range of 0. 038-0.190 microg (r = 0.9999). The average recovery was 98.7% with the RSD of 2.36%. CONCLUSION: The method appears to be simple, accurate and reproducible, it can be used to determine the content of paprazine in P. orientale.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/análise , Polygonum/química , Medicamentos de Ervas Chinesas/química
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