Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Heliyon ; 9(5): e16346, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37234632

RESUMO

Despite the rapid growth in sales of imported spirits in the Chinese market, consumers are struggling to easily buy high-quality imported spirits with favorable price. The imported spirits flash delivery applications are proposed to provide Chinese consumers with high-quality services delivered within a few hours. This study extends UTUAT2 with knowledge, risk and innovativeness to identify factors influencing Chinese consumers' use of flash delivery services for imported spirits. With the help of service providers, 315 valid questionnaires were collected and an empirical study was carried out. Findings suggest that social influence, habit, innovativeness and knowledge all have significant effects on usage. In particular, knowledge has significant moderating effects on relationships between social influence, habit, innovativeness and usage. This research is supposed to help imported spirits flash delivery providers to further expand the market, and will be of great help to the investment decisions of multinational spirits manufacturers in China.

2.
Sci Rep ; 12(1): 6856, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35477990

RESUMO

The introduction of digital currency electronic payment (DCEP) by the Central Bank of China is conducive to the central bank's timely grasp of macroeconomic dynamics and the internationalization of RMB. As DCEP is one of the first digital currencies issued by the central bank to be used on a large scale internationally, it is necessary to conduct research on its user adoption. Therefore, this research extends the unified theory of acceptance and use of technology (UTAUT) to explore factors affecting the adoption of DCEP. The researchers cooperated with city banks that have started to use DCEP, and distributed questionnaires to users in the lobbies of these banks. A total of 295 valid questionnaires were empirically examined with Smart-PLS. The results indicate that perceived fairness, habits, social influence and national identity have significant effects on usage, with p values less than 0.05. National identity is shown to be a significant moderator of the relationships between perceived fairness, habit, perceived risk and usage, with p values less than 0.05. National identity is shown to have no moderating effect between social influence and usage, with a p value greater than 0.05. This research provides the central bank and the government with suggestions to increase user enthusiasm and reduce user perceived risks, thereby promoting the widespread use of DCEP.


Assuntos
Confidencialidade , Tecnologia , China , Inquéritos e Questionários
3.
PLoS One ; 16(2): e0245964, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33544745

RESUMO

Blockchain-based loan system can be summed up as: information exchange between various government departments; information exchange between enterprises and various financial institutions; detection of the actual use of loans in the form of encrypted currency. This technology is supposed to reduce a lot of financing costs for SMEs on average. Therefore, this research extends complexity theory to discover the factors that affect the use of Blockchain loan systems by SMEs. Complexity, perceived risk, perceived fairness and reward sensitivity prove to have significant effects on usage intention. Complexity proves to have moderating effects on other relationships. This research may contribute to the system performance improvement and provide opportunities for SMEs to share information with financial institutions or individuals around the world, thereby providing investors with equal opportunities for competition.


Assuntos
Blockchain/economia , Investimentos em Saúde , Humanos , Recompensa , Medição de Risco , Inquéritos e Questionários
4.
PLoS One ; 15(6): e0234155, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497123

RESUMO

We investigate factors affecting individual investors' switching intention from traditional financial market to crypto-currency financial market. By sampling factors of individual investors related with crypto-currency (CC), the study applies structural equation modeling method (SEM) to investigate their effects on switching intention by integrating PPM and Reinforcement Sensitivity theories (RST) to form a pulling, pushing and mooring effects model. The investigation indicates that crypto-currency market can be regarded as a kind of beneficial supplement of tradition investment market for those individual investors who are with high innovativeness, reward sensitivity, knowledge and perceived risk. This study proves that the individual investors are not only attracted by significant expected return from crypto-currency but also relevant knowledge and risks disclosed by crypto-currency market regulators and distributors. The findings reinforce major roles for both market regulators and individual investors in considering and providing insights for future policy, management and investigations.


Assuntos
Administração Financeira/métodos , Intenção , Investimentos em Saúde , Assunção de Riscos , Humanos , Percepção
5.
Appl Environ Microbiol ; 69(12): 7116-23, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14660356

RESUMO

Two arabinosidases, alpha-L-arabinopyranosidase (no EC number) and alpha-L-arabinofuranosidase (EC 3.2.1.55), were purified from ginsenoside-metabolizing Bifidobacterium breve K-110, which was isolated from human intestinal microflora. alpha-L-Arabinopyranosidase was purified to apparent homogeneity, using a combination of ammonium sulfate fractionation, DEAE-cellulose, butyl Toyopearl, hydroxyapatite Ultrogel, QAE-cellulose, and Sephacryl S-300 HR column chromatography, with a final specific activity of 8.81 micro mol/min/mg. alpha-L-Arabinofuranosidase was purified to apparent homogeneity, using a combination of ammonium sulfate fractionation, DEAE-cellulose, butyl Toyopearl, hydroxyapatite Ultrogel, Q-Sepharose, and Sephacryl S-300 column chromatography, with a final specific activity of 6.46 micro mol/min/mg. The molecular mass of alpha-L-arabinopyranosidase was found to be 310 kDa by gel filtration, consisting of four identical subunits (77 kDa each, measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis [SDS-PAGE]), and that of alpha-L-arabinofuranosidase was found to be 60 kDa by gel filtration and SDS-PAGE. alpha-L-Arabinopyranosidase and alpha-L-arabinofuranosidase showed optimal activity at pH 5.5 to 6.0 and 40 degrees C and pH 4.5 and 45 degrees C, respectively. Both purified enzymes were potently inhibited by Cu(2+) and p-chlormercuryphenylsulfonic acid. alpha-L-Arabinopyranosidase acted to the greatest extent on p-nitrophenyl-alpha-L-arabinopyranoside, followed by ginsenoside Rb2. alpha-L-Arabinofuranosidase acted to the greatest extent on p-nitrophenyl-alpha-L-arabinofuranoside, followed by ginsenoside Rc. Neither enzyme acted on p-nitrophenyl-beta-galactopyranoside or p-nitrophenyl-beta-D-fucopyranoside. These findings suggest that the biochemical properties and substrate specificities of these purified enzymes are different from those of previously purified alpha-L-arabinosidases. This is the first reported purification of alpha-L-arabinopyranosidase from an anaerobic Bifidobacterium sp.


Assuntos
Bifidobacterium/enzimologia , Bifidobacterium/crescimento & desenvolvimento , Glicosídeo Hidrolases/isolamento & purificação , Intestinos/microbiologia , Anaerobiose , Ginsenosídeos/metabolismo , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/metabolismo , Humanos , Masculino
6.
Biol Pharm Bull ; 26(8): 1170-3, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12913270

RESUMO

Beta-D-Xylosidase (EC 3.2.1.37) has been purified from ginsenoside Ra-metabolizing Bifidobacterium breve K-110, which was isolated from human intestinal microflora. beta-D-Xylosidase was purified to apparent homogeneity by a combination of ammonium sulfate precipitation, QAE-cellulose, butyl-toyopearl, hydroxyapatit and Q-Sepharose column chromatographies with the final specific activity of 51.8 micromol/min/mg. Molecular weight of beta-D-xylosidase is 49 kDa by SDS-PAGE and gel filtration, which consisted of a single subunit. beta-D-Xylosidase showed optimal activity at pH 5.0 and 37 degrees C. The purified enzyme was potently inhibited by PCMS. beta-D-Xylosidase acted to the greatest extent on p-nitrophenyl-beta-D-xylopyranoside, followed by ginsenoside Ra1 and ginsenoside Ra2. This enzyme hydrolyzed xylan to xylose, but did not act on p-nitrophenyl-beta-glucopyranoside, p-nitrophenyl-beta-galactopyranoside or p-nitrophenyl-beta-D-fucopyranoside. These findings suggest that this is the first reported purification of ginsenoside-hydrolyzing beta-D-xylosidase from an anaerobic Bifidobacterium sp.


Assuntos
Bifidobacterium/isolamento & purificação , Ginsenosídeos/isolamento & purificação , Intestinos/microbiologia , Xilosidases/isolamento & purificação , Bifidobacterium/metabolismo , Ginsenosídeos/química , Ginsenosídeos/metabolismo , Humanos , Hidrólise , Mucosa Intestinal/metabolismo , Xilosidases/química , Xilosidases/metabolismo
7.
Eur J Biochem ; 270(15): 3168-73, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12869191

RESUMO

Salt-active acharan sulfate lyase (no EC number) has been purified from Bacteroides stercoris HJ-15, which was isolated from human intestinal bacteria with GAG degrading enzymes. The enzyme was purified to apparent homogeneity by a combination of QAE-cellulose, diethylaminoethyl (DEAE)-cellulose, CM-Sephadex C-50, HA ultrogel and phosphocellulose column chromatography with the final specific activity of 81.33 micro mol x min-1 x mg-1. The purified salt-active acharan sulfate lyase was activated to 5.3-fold by salts (KCl and NaCl). The molecular weight of salt-active acharan sulfate lyase was 94 kDa by SDS/PAGE and gel filtration. The salt-active acharan sulfate lyase showed optimal activity at pH 7.2 and 40 degrees C. Salt-active acharan sulfate lyase activity was potently inhibited by Cu2+, Ni2+ and Zn2+. This enzyme was inhibited by some agents, butanediol and p-chloromercuric sulfonic acid, which modify arginine and cysteine residues. The purified Bacteroidal salt-active acharan sulfate lyase acted to the greatest extent on acharan sulfate, to a lesser extent on heparan sulfate and heparin. The biochemical properties of the purified salt-active acharan sulfate lyase are different from those of the previously purified heparin lyases. However, these findings suggest that the purified salt-active acharan sulfate lyase may belong to heparin lyase II.


Assuntos
Bacteroides/enzimologia , Heparina Liase/isolamento & purificação , Heparina Liase/metabolismo , Sequência de Aminoácidos , Heparina Liase/química , Concentração de Íons de Hidrogênio , Cinética , Cloreto de Potássio/farmacologia , Cloreto de Sódio/farmacologia , Especificidade por Substrato , Temperatura
8.
Biol Pharm Bull ; 25(6): 743-7, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12081140

RESUMO

When ginsenoside R(c) was anaerobically incubated with human fecal microflora, all specimens metabolized ginsenoside R(c) to compound K and protopanaxadiol. The main metabolite was compound K. Among the bacteria isolated from human fecal microflora, most bacteria, such as Bacteroides sp., Eubacterium sp., and Bifidobacterium sp. potently transformed ginsenoside R(c) to compound K. Bifidobacterium K-103 and Eubacterium A-44 transformed it to compound K via ginsenoside R(d) and Bacteroides HJ-15 and Bifidobacterium K-506 metabolized to compound K via ginsenoside Mb, which was isolated as a new metabolite (M.W. 940[+Na]). Among ginsenoside R(c) and its metabolites, compound K exhibited the most potent antiallergic activity on the IgE-induced RBL cell line as well as potent cytotoxic activity against tumor cell lines.


Assuntos
Antialérgicos/metabolismo , Antialérgicos/farmacologia , Bactérias/metabolismo , Ginsenosídeos/metabolismo , Ginsenosídeos/farmacologia , Mucosa Intestinal/metabolismo , Intestinos/microbiologia , Animais , Biotransformação , Linhagem Celular , Fezes/microbiologia , Humanos , Cinética , Leucemia L1210/metabolismo , Leucemia P388/metabolismo , Espectroscopia de Ressonância Magnética , Camundongos , Óxido Nítrico/biossíntese , Células Tumorais Cultivadas , beta-N-Acetil-Hexosaminidases/biossíntese
9.
Eur J Biochem ; 269(12): 2934-40, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12071957

RESUMO

Two novel chondroitinases, chondroitin ABC lyase (EC 4.2.2.4) and chondroitin AC lyase (EC 4.2.2.5), have been purified from Bacteroides stercoris HJ-15, which was isolated from human intestinal bacteria with glycosaminoglycan degrading enzymes. Chondroitin ABC lyase was purified to apparent homogeneity by a combination of QAE-cellulose, CM-Sephadex C-50, hydroxyapatite and Sephacryl S-300 column chromatography with a final specific activity of 45.7 micromol.min-1.mg-1. Chondroitin AC lyase was purified to apparent homogeneity by a combination of QAE-cellulose, CM-Sephadex C-50, hydroxyapatite and phosphocellulose column chromatography with a final specific activity of 57.03 micromol.min-1.mg-1. Chondroitin ABC lyase is a single subunit of 116 kDa by SDS/PAGE and gel filtration. Chondroitin AC lyase is composed of two identical subunits of 84 kDa by SDS/PAGE and gel filtration. Chondroitin ABC and AC lyases showed optimal activity at pH 7.0 and 40 degrees C, and 5.7-6.0 and 45-50 degrees C, respectively. Both chondroitin lyases were potently inhibited by Cu2+, Zn2+, and p-chloromercuriphenyl sulfonic acid. The purified Bacteroidal chondroitin ABC lyase acted to the greatest extent on chondroitin sulfate A (chondroitin 4-sulfate), to a lesser extent on chondroitin sulfate B (dermatan sulfate) and C (chondroitin 6-sulfate). The purified chondroitin AC lyase acted to the greatest extent on chondroitin sulfate A, and to a lesser extent on chondroitin C and hyaluronic acid. They did not act on heparin and heparan sulfate. These findings suggest that the biochemical properties of these purified chondroitin lyases are different from those of the previously purified chondroitin lyases.


Assuntos
Bacteroides/enzimologia , Condroitina ABC Liase/metabolismo , Condroitina Liases/metabolismo , Sulfatos de Condroitina/metabolismo , Dermatan Sulfato/metabolismo , Bactérias Anaeróbias/enzimologia , Condroitina ABC Liase/isolamento & purificação , Condroitina Liases/isolamento & purificação , Humanos , Intestinos/microbiologia , Cinética , Especificidade por Substrato
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA