890 research outputs found
Influence of Visual Cues of E-WOM on Consumers\u27 Purchase Intention
E-WOM is considered to be an important factor affecting consumers\u27 purchasing decisions. Now many scholars focus on the specific presentation of e-WOM to study consumer behavior, and the research on the influence mechanism of the form-based characteristics of e-WOM information on consumers is relatively lacking. Based on clue utilization theory and the perspective of consumer psychology processing, we explores the impact of visual cues of e-WOM on consumer perception and purchase intention. The experimental results show that the visual cues of e-WOM promote the mental imagery of consumers, and then have a significant impact on their perceptual diagnosis and purchase intention. Finally, the corresponding marketing management inspiration is proposed
Influence of Media Richness of E-WOM on Consumers\u27 Mental Imagery and Attitudes
E-WOM has become a hot research topic. Based on the theory of media richness, this paper divides online reviews into three types according to the degree of e-WOM richness from low to high - text , text + image and text + image + video . From the perspective of mental imagery, this paper explores the consumer attitudes of these three kinds of reviews with different richness. The Experimental data analysis shows that compared with text reviews, text + image reviews have more significant impact on consumers\u27 metal imagery and attitudes; as a form of high richness e-WOM, text + image + video has the most significant impact on consumers\u27 metal imagery and attitudes. This discovery points out several meaningful directions for the further study from the perspective of media richness
Preparation and characterization of solid lipid nanoparticles loaded with frankincense and myrrh oil
The aim of the present study was to prepare solid lipid nanoparticles (SLNs) for the oral delivery of frankincense and myrrh essential oils (FMO). Aqueous dispersions of SLNs were successfully prepared by a high-pressure homogenization method using Compritol 888 ATO as the solid lipid and soybean lecithin and Tween 80 as the surfactants. The properties of the SLNs such as particle size, zeta potential (ZP), and drug encapsulation efficiency (EE) were investigated. The morphology of SLNs was observed by transmission electron microscopy (TEM). The crystallinity of the formulation was analyzed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). In addition, drug evaporation release and antitumor activity were also studied. Round SLNs with a mean size of 113.3 ± 3.6 nm, a ZP of −16.8 ± 0.4 mV, and an EE of 80.60% ± 1.11% were obtained. DSC and XRD measurements revealed that less ordered structures were formed in the inner cores of the SLN particles. Evaporation loss of the active components in FMO could be reduced in the SLNs. Furthermore, the SLN formulation increased the antitumor efficacy of FMO in H22-bearing Kunming mice. Hence, the presented SLNs can be used as drug carriers for hydrophobic oil drugs extracted from traditional Chinese medicines
In vitro cellular uptake of evodiamine and rutaecarpine using a microemulsion
Yong-Tai Zhang, Zhe-Bin Huang, Su-Juan Zhang, Ji-Hui Zhao, Zhi Wang, Ying Liu, Nian-Ping FengDepartment of Pharmaceutics, Shanghai University of Traditional Chinese Medicine, Shanghai, The People's Republic of ChinaObjective: To investigate the cellular uptake of evodiamine and rutaecarpine in a microemulsion in comparison with aqueous suspensions and tinctures.Materials and methods: A microemulsion was prepared using the dropwise addition method. Mouse skin fibroblasts were cultured in vitro to investigate the optimal conditions for evodiamine and rutaecarpine uptake with different drug concentrations and administration times. Under optimal conditions, the cellular uptake of microemulsified drugs was assayed and compared to tinctures and aqueous suspensions. Rhodamine B labeling and laser scanning confocal microscopy (LSCM) were used to explore the distribution of fluorochrome transferred with the microemulsion in fibroblasts. Cellular morphology was also investigated, using optical microscopy to evaluate microemulsion-induced cellular toxicity.Results: The maximum cellular drug uptake amounts were obtained with a 20% concentration (v/v) of microemulsion and an 8 hour administration time. Drug uptake by mouse skin fibroblasts was lowest when the drugs were loaded in microemulsion. After incubation with rhodamine B-labeled microemulsion for 8 hours, the highest fluorescence intensity was achieved, and the fluorochrome was primarily distributed in the cytochylema. No obvious cellular morphologic changes were observed with the administration of either the microemulsion or the aqueous suspension; for the tincture group, however, massive cellular necrocytosis was observed.Conclusion: The lower cellular uptake with microemulsion may be due to the fact that most of the drug loaded in the microemulsion vehicle was transported via the intercellular space, while a small quantity of free drug (released from the vehicle) was ingested through transmembrane transport. Mouse skin fibroblasts rarely endocytosed evodiamine and rutaecarpine with a microemulsion as the vehicle. The microemulsion had no obvious effect on cellular morphology, suggesting there is little or no cellular toxicity associated with the administration of microemulsion on mouse skin fibroblasts.Keywords: mouse skin fibroblasts, evodiamine, rutaecarpine, microemulsion, cellular uptake, in vitr
Enhanced transdermal delivery of evodiamine and rutaecarpine using microemulsion
Yong-Tai Zhang, Ji-Hui Zhao, Su-Juan Zhang, Yang-Zi Zhong, Zhi Wang, Ying Liu, Feng Shi, Nian-Ping FengSchool of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of ChinaObjective: The purpose of this study was to improve skin permeation of evodiamine and rutaecarpine for transdermal delivery with microemulsion as vehicle and investigate real-time cutaneous absorption of the drugs via in vivo microdialysis.Methods: Pseudoternary phase diagrams were constructed to evaluate microemulsion regions with various surfactants and cosurfactants. Nine formulations of oil in water microemulsions were selected as vehicles for assessing skin permeation of evodiamine and rutaecarpine in ex vivo transdermal experiments. With a microdialysis hollow fiber membrane implanted in the skin beneath the site of topical drug administration, dialysis sampling was maintained for 10 hours and the samples were detected directly by high performance liquid chromatography. Real-time concentrations of the drugs in rat skin were investigated and compared with those of conventional formulations, such as ointment and tincture. Furthermore, the drugs were applied to various regions of the skin using microemulsion as vehicle.Results: In ex vivo transdermal experiments, cutaneous fluxes of evodiamine and rutaecarpine microemulsions were 2.55-fold to 11.36-fold and 1.17-fold to 6.33-fold higher, respectively, than those of aqueous suspensions. Different drug loadings, microemulsion water content, and transdermal enhancers markedly influenced the permeation of evodiamine and rutaecarpine. In microemulsion application with in vivo microdialysis, the maximum concentration of the drugs (evodiamine: 18.23 ± 1.54 ng/mL; rutaecarpine: 16.04 ± 0.69 ng/mL) were the highest, and the area under the curve0–t of evodiamine and rutaecarpine was 1.52-fold and 2.27-fold higher than ointment and 3.06-fold and 4.23-fold higher than tincture, respectively. A greater amount of drugs penetrated through and was absorbed by rat abdominal skin than shoulder and chest, and a reservoir in the skin was found to supply drugs even after the microemulsion was withdrawn.Conclusion: Compared to conventional formulations, higher cutaneous fluxes of evodiamine and rutaecarpine were achieved with microemulsion. Based on this novel transdermal delivery, the transdermal route was effective for the administration of the two active alkaloids.Keywords: microemulsion, evodiamine, rutaecarpine, transdermal delivery, microdialysi
Graphene Plasmonics: A Platform for 2D Optics
2D optics is gradually emerging as a frontier in modern optics. Plasmons in graphene provide a prominent platform for 2D optics in which the light is squeezed into atomic scale. This report highlights some recent progresses in graphene plasmons toward the 2D optics. The launch, observation, and advanced manipulation of propagating graphene plasmons for 2D optical circuits are described. Representative achievements associated with graphene metasurfaces, challenges, recent progresses like photoexcited graphene metasurfaces, and the transformation optics linking 2D to bulk optics with singularity are investigated
Microemulsion-based novel transdermal delivery system of tetramethylpyrazine: preparation and evaluation in vitro and in vivo
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