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1.
Tour Manag Perspect ; 44: 101029, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36212167

RESUMO

To prevent COVID-19, tourists are required to maintain distance from other people. However, interpersonal contact is a crucial element in tourists' well-being. It is necessary to ask how eliciting both eudaimonic and hedonic well-being will change as a result. The answer is unclear. To address this issue, we used partial least squares equation modeling to examine a city that has efficiently responded to COVID-19. This study expands the influencing model of tourists' well-being by revealing how physical distance moderates the influence of such factors as contact intention, leisure involvement, and flow experience. The study throws light on tourists' psychological recovery and destination management in the post-COVID-19 era.

2.
Front Psychol ; 13: 965655, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35967706

RESUMO

Digital tourism has developed rapidly, especially in museums. However, as people become increasingly familiar with digital museums, their use intentions and behavior have changed. Taking the Digital Palace Museum in China as an example, applying the PLS-SEM method, this study uncovers visitors' use intentions and actual use behavior for digital museums by integrating the new UTAUT model (UTAUT2) and TTF model (TTF under social distancing) and introduces the PATS (Pandemic Anxiety Travel Scale) model to reveal how pandemic anxiety promotes the transformation of use intentions into use behavior more easily. The results show that performance expectations, hedonic motivations, habits, and task-technology-fit positively affect use intentions for digital museums. However, the price-saving orientation negatively affects use intentions. Pandemic anxiety moderates the effect of use intentions on actual behavior. When travel anxiety is relatively high, use intentions have a greater effect on use behavior for digital museums. The results reveal the influencing factors on use intentions of digital museums and the moderating effect of pandemic anxiety on the relation between use intentions and actual behavior.

3.
J Biomed Mater Res A ; 87(2): 364-72, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18181113

RESUMO

A novel and simple method to form water-dispersed magnetic nanoparticles was successfully developed through glucosaminic acid-surface modification of iron oxide nanoparticles. The resultant glucosaminic acid-modified magnetic nanoparticles (GA-MNPs) had not only good uniformity in spherical shape with diameter of about 10-13 nm, but also possessed excellent water-dispersity and stability. In cell culture experiments, the internalization of GA-MNPs into different kinds of cells was observed over a 5-day period. The results indicated that the internalization of GA-MNPs into mouse macrophage cells and mouse embryonic fibroblast cells was not observed after 40 h of culturing. However, the GA-MNPs were internalized quickly into cancer cells after just 24 h of culturing. TEM images of the GA-MNPs uptake in ECA-109 cells were used to study the internalization mechanisms of GA-MNPs and their distribution in ECA-109 cells. Additionally, a water-dispersed magnetic capture probe was prepared by immobilization of oligonucleotides onto GA-MNPs, and the probe was used for detection and separation of their complementary oligonucleotides sequence.


Assuntos
Magnetismo , Nanopartículas Metálicas/química , Animais , Transporte Biológico/fisiologia , Biotina/química , Linhagem Celular , Glucosamina/análogos & derivados , Glucosamina/química , Humanos , Teste de Materiais , Camundongos , Estrutura Molecular , Ácidos Oleicos/química , Oligonucleotídeos/química , Tamanho da Partícula , Propriedades de Superfície , Água/química
4.
Drug Deliv ; 12(6): 399-407, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16253956

RESUMO

To prepare and investigate the potential of the niosomes vaginal delivery system for systemic treatment of insulin is the goal of this study. Two kinds of vesicles with Span 40 and Span 60 were prepared by lipid phase evaporation methods with sonication. The niosomal entrapment efficiency was determined by column chromatography. The particle size and morphology of the vesicles also were evaluated. The results showed optimized niosomes prepared in this study had niosomal entrapment efficiency 26.68 +/- 1.41% for Span 40 and 28.82 +/- 1.35% for Span 60, respectively. The particle sizes of Span 40 niosomes and Span 60 niosomes were 242.5 +/- 20.5 nm and 259.7 +/- 33.8 nm, respectively. There were no significant differences in appearance between the two types of vesicles. The hypoglycemic effects, and insulin concentrations after vaginal administration of insulin vesicles to rats were investigated. Compared with subcutaneous administration of insulin solution, the relative pharmacological bioavailability and the relative bioavailability of vaginal administration of insulin vesicles were determined. Compared with subcutaneous administration of insulin solution, the relative pharmacological bioavailability and the relative bioavailability of insulin-Span 60 vesicles group were 8.43% and 9.61%, and insulin-Span 40 niosomes were 9.11% and 10.03% (p > 0.05). Span 60 and Span 40 niosomes were both higher than blank Span 40, Span 60 vesicles, and free insulin physical mixture groups (p < 0.05). The results indicates insulin-Span 60, Span 40 niosomes had an enhancing effect on vaginal delivery of insulin. Although the factors controlling the process for penetration of a portion of vaginally administrated niosomes into bloodstream from vaginal tract is still not fully understood, our results demonstrated that after encapsulation in niosomes of definite type, insulin became an active and efficiently therapeutic agent when administrated vaginally and might be a good carrier for vaginal delivery of protein drugs.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Portadores de Fármacos/química , Hipoglicemiantes/farmacocinética , Insulina/farmacocinética , Polissorbatos/química , Administração Intravaginal , Aloxano , Animais , Área Sob a Curva , Disponibilidade Biológica , Glicemia , Diabetes Mellitus Experimental/sangue , Composição de Medicamentos , Estabilidade de Medicamentos , Feminino , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/sangue , Injeções Subcutâneas , Insulina/administração & dosagem , Insulina/sangue , Ovariectomia , Tamanho da Partícula , Ratos , Ratos Wistar , Solubilidade
5.
Drug Dev Ind Pharm ; 31(4-5): 375-83, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-16093203

RESUMO

Clotrimazole, which is an imidazole derivative antifungal agent, was widely used for the treatment of mycotic infections of the genitourinary tract. To develop alternative formulation for the vaginal administration of clotrimazole to provide sustained and controlled release of appropriate drug for local vaginal therapy, liposomes/niosomes were evaluated as delivery vehicles. To optimize the preparation of liposomes/niosomes with regard to size and entrapment efficiency, multilamellar liposomes/niosomes containing drug were prepared by lipid hydration method. The prepared liposomes/niosomes were incorporated into 2% carbopol gel, and the systems were evaluated for drug stability in phosphate-buffered saline (pH 7.4) and simulated vaginal fluid at 37 +/- 1 degrees C. Further, the vesicle gel system was evaluated by antifungal activity and tolerability on tissue level in rat.


Assuntos
Clotrimazol/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Resinas Acrílicas , Administração Intravaginal , Animais , Antifúngicos/administração & dosagem , Antifúngicos/farmacocinética , Candidíase/tratamento farmacológico , Clotrimazol/administração & dosagem , Clotrimazol/química , Modelos Animais de Doenças , Portadores de Fármacos/química , Estabilidade de Medicamentos , Armazenamento de Medicamentos/métodos , Feminino , Géis/química , Concentração de Íons de Hidrogênio , Lipossomos/química , Testes de Sensibilidade Microbiana/métodos , Tamanho da Partícula , Polivinil/química , Ratos , Ratos Sprague-Dawley , Vagina/efeitos dos fármacos , Vagina/microbiologia , Vagina/patologia
6.
J Control Release ; 107(1): 53-64, 2005 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-16005093

RESUMO

Blank and bovine serum albumin (BSA)-loaded microspheres based on poly(lactic-acid-alt-glycolic acid) (D,L-PLGA50) and poly(epsilon-caprolactone)-b-poly(lactic-acid-alt-glycolic acid) (PCL-b-D,L-PLGA50) were successfully fabricated using water-in-oil-in-water (w/o/w) double-emulsion extraction/evaporation technique. In vitro degradation of the blank microspheres was characterized by techniques including nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The PCL-b-D,L-PLGA50 copolymer (Mn: number-average molecular weight, Mw: weight-average molecular weight, Mn=44800, Mw/Mn=MWD=1.24, epsilon-caprolactone (CL) %=20.4% in molar ratio) had similar rate of molecular weight reduction compared with the D,L-PLGA50 copolymer before 5 weeks of in vitro degradation. The BSA % loading efficiency of microspheres was mainly controlled by both block copolymer composition and macromolecular architecture, while the sequence structure and the molecular weight of copolymer had no apparent effect on it. Significantly, The PCL-b-D,L-PLGA50 copolymer microspheres showed good release profiles with a nearly constant release during 20-110 days.


Assuntos
Preparações de Ação Retardada/metabolismo , Ácido Láctico/metabolismo , Microesferas , Ácido Poliglicólico/metabolismo , Polímeros/metabolismo , Animais , Varredura Diferencial de Calorimetria , Bovinos , Cromatografia em Gel , Preparações de Ação Retardada/química , Técnicas In Vitro , Ácido Láctico/química , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Peso Molecular , Ácido Poliglicólico/química , Polímeros/química , Soroalbumina Bovina/metabolismo , Temperatura , Fatores de Tempo
7.
Chem Pharm Bull (Tokyo) ; 53(6): 620-4, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15930770

RESUMO

Clotrimazole (CT)-containing proliposomes were prepared by penetrating an ethanol solution of CT and Egg phosphatidylcholine (PC) into microporous sorbitol particles, followed by vacuum evaporation of the solvent. As a result, CT proliposomes with free-flowing flowability were obtained. On contact with water, the proliposomes were rapidly converted into a liposomal dispersion, in which a certain amount of CT was entrapped by the liposomes. The result in scanning electronic micrograph confirmed the formation of liposomes structures from proliposomes, and the particles revealed round or ellipse. The ratio of drug to total lipid, ratio of PC to cholesterol and ratio of lipid to sorbitol affected the entrapment efficiency (EE%). The EE% of optimized formulation (CT 10 mg, 0.1 g total lipid, PC/CH ratio is 60 : 40 and 1 g sorbitol) in this investigation was 96.2+/-1.5%. The proliposomes system can provide sustaining release in simulated vaginal fluid at 37+/-1 degrees C for 24 h. In-vivo performance of blank proliposomes, a physical mixture of sorbitol and drug, clotrimazole proliposomes and commercial ointment formulation were evaluated using antifungal activity test. At 7 d post-dose, the c.f.u. of C. albicans decreased in proliposomes-treated groups than ointment and the physical mixture (t-Student, p<0.05). The results indicated that CT-containing vaginal proliposomes prolonged drug release and may increase amount of drug retention into the mucosa to result in more antifungal efficacy. In addition, CT-proliposomes did not affect the morphology of vaginal tissues. Therefore, the dosage form might be further developed for safe, convenient, and effective treatment of vaginal candidasis with reduced dosing interval.


Assuntos
Clotrimazol/administração & dosagem , Clotrimazol/síntese química , Pró-Fármacos/administração & dosagem , Pró-Fármacos/síntese química , Animais , Clotrimazol/farmacocinética , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Lipossomos , Pró-Fármacos/farmacocinética , Ratos , Ratos Sprague-Dawley , Vagina/citologia , Vagina/efeitos dos fármacos
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