70 research outputs found
CAUSE-EFFECT RELATIONS AND OPTIMIZATION OF TABLET CONTAINING EUCOMMIA ULMOIDES AND GARDENIA JASMINOIDES SPRAY-DRIED EXTRACTS
Objective: The E. ulmoides and G. jasminoides (EG) tablets containing 67 mg E. ulmoides spray-dried extract (ESE) and 173 mg G. jasminoides spray-dried extract (GSE) were prepared by employing the direct compression method. Due to the poor flowability and compressibility of the two spray-dried extracts, various excipients were added at different ratios so that the blends can be compressed into tablets with the required standards. This study aimed at the cause-effect relations and optimization of the EG tablet formulation.Methods: Different diluents including dibasic calcium phosphate anhydrous (DCPA), silicified microcrystalline cellulose (SMCC), spray-dried lactose (SDL) and the active ingredients (blend of ESE and GSE at the ratio of 67:173, w/w) were separately investigated their own physical properties. The binary mixtures of the active ingredients with different ratios of DCPA, SMCC, and SDL were evaluated their flowability. D-optimal design based on three independent variables (% DCPA, % croscarmellose sodium (CCS) and % SMCC) was applied to evaluate the cause-effect relations and optimize the EG tablet formulation. The weight variation, disintegration time, hardness and friability were investigated as four dependent variables.Results: The flowability of the powders was found to be affected by the particle size distribution, particle shape and density. The three diluents could significantly improve the flowability of the active ingredients. All independent variables had significant effects on the dependent variables. An increase in % SMCC reduced the weight variation, hardness and increased the friability of tablets. Disintegration time was found to be in the negative relations with % CCS. The tablet hardness was in positive relations with % DCPA. The optimized EG tablet formulation composed of 9 % DCPA (w/w), 35 % SMCC (w/w), and 14 % CCS (w/w) of the excipient blend. The weight variation, disintegration time, hardness and friability of the optimized EG tablets were found to be 1.8 %, 11.7 min, 61.4 N, and 0.5 %, respectively.Conclusion: The ESE and GSE could be formulated into tablet by using direct compression method. The cause-effect relations and optimization of EG tablet formulation were studied and reported for the first time
Synthesis and Optical Characterization of Dye Doped in Ormosil Nanospheres for Bioapplications
Dye-doped ORMOSIL (organically modified silicate) nanoparticles (NPs) have significant advantages over single-dye labeling in signal amplification, photostability and surface modification for various biological applications. The dyes: Rhodamine 6G (R6G) and Rhodamine B (RB) were successfully incorporated into ORMOSIL nanoparticles fabricated by micellar nanochemistry from Trimethoxysilane CHSi(OCH) precursor. The optical characterization of dye-doped ORMOSIL NPs was studied in comparison with it’s of free dye in solution. The results shown that the photostability of ORMOSIL dye doped nanospheres is much improved in comparison with it’s of dye in solution. Other studies of the photophysical properties such as anisotropy, fluorescence lifetime and energy transfer were also done
Experiment and FEM Modelling of Bond Behaviors between Pre-stressing Strands and Ultra–High–Performance Concrete
The objective of this paper is to investigate the bond properties of prestressing strands embedded in Ultra–High–Performance Concrete (UHPC).The UHPC was made in laboratory using local materials in Vietnam.Its mixture contains: silica aggregates, portland cement PC40, fly ash, silica fume, polycarboxylate superplasticizer and the micro steel fibers.The experimental process is realized on a pull-out test. The volume fraction of micro steel fibers in UHPC was 2%. The prestressing strand with diameters of 15.2mm was considered. The interface shear strength between strand and UHPC is identified based on the results of force and displacement obtained during the pull-out test. The Cohesive Zone Model (CZM) is implemented in finite element model to study this interface behavior. This model described by a piecewise linear elastic law. The CZM’s parameters are identified based on experimental results of pull-out test.The numerical studies are used the CZM in ANSYS software. Two numerical tests are realized and compared with experimental results: pull-out test and other test to verify the deflection of I girder due to prestressing force
Experiment and FEM Modelling of Bond Behaviors between Pre-stressing Strands and Ultra–High–Performance Concrete
The objective of this paper is to investigate the bond properties of prestressing strands embedded in Ultra–High–Performance Concrete (UHPC).The UHPC was made in laboratory using local materials in Vietnam.Its mixture contains: silica aggregates, portland cement PC40, fly ash, silica fume, polycarboxylate superplasticizer and the micro steel fibers.The experimental process is realized on a pull-out test. The volume fraction of micro steel fibers in UHPC was 2%. The prestressing strand with diameters of 15.2mm was considered. The interface shear strength between strand and UHPC is identified based on the results of force and displacement obtained during the pull-out test. The Cohesive Zone Model (CZM) is implemented in finite element model to study this interface behavior. This model described by a piecewise linear elastic law. The CZM’s parameters are identified based on experimental results of pull-out test.The numerical studies are used the CZM in ANSYS software. Two numerical tests are realized and compared with experimental results: pull-out test and other test to verify the deflection of I girder due to prestressing force
Theranostic Gold Nanoshells: from Synthesis to Imaging and Photothermal Therapy Applications
Gold nanoshells (GNSs) were grown on monodispersed aminoprotpyltriethoxysilane (APTES) functionalized of silica nanoparticles (NPs) cores with varying sizes ranging from 40-180 nm synthesized by Stober route. Gold shells were deposited onto the surface of silica NPs by tetrakis(hydroxymethyl) phosphonium chloride (THPC) and electroless gold plating method. The coverage of the gold nanoshells on the surfaces of the silica NPs was evaluated using UV-VIS/NIR spectrospcopy and transmission electron microscopy (TEM). The plasmon resonance wavelengths of these gold nanoshells were tunable from visible to near infrared region. The GNSs were also bioconjugated with anti-HER2 monoclonal antibody for diagnostic breast cancer cells using dark field microscope technique. These GNS NPs play a role as nanoheaters transforming light to heat. With the present of these GNS NPs at volume density of NPs.cm in chicken tissue samples, illuminated by 808 nm laser at the power density of 62~W.cm the temperature of tissue sample reachs 110\rc{ }C after 20 minutes illumination
The Light-to-heat Conversion of Gold Nanoshells and Nanorods in Tissues
We perform a set of experiments on photo-heating in tissues containing gold nanoshells (NSs) and nanorods (NRs). The temperature of tissues were measured with different amounts gold NSs and NRs under illumination of a continuous diode laser at 808 nm and power density from 20 to 62 W/cm. The temperature of the tissues injected gold nanoparticles increased to $66 \pm 4C for NSs and   C for gold NRs after 10 min exposition at power density 35 W/cm. The control tissue without gold nanoparticles demonstrated a significantly lower temperature C in the same time of illumination. The temperature can be reached up to around 100C for tissue with both NSs and NRs at 62 W/cm inrradiation for min
Tuberculosis among economic migrants: a cross-sectional study of the risk of poor treatment outcomes and impact of a treatment adherence intervention among temporary residents in an urban district in Ho Chi Minh City, Viet Nam.
BACKGROUND
Tuberculosis (TB) remains a major cause of avoidable deaths. Economic migrants represent a vulnerable population due to their exposure to medical and social risk factors. These factors expose them to higher risks for TB incidence and poor treatment outcomes.
METHODS
This cross-sectional study evaluated WHO-defined TB treatment outcomes among economic migrants in an urban district of Ho Chi Minh City, Viet Nam. We measured the association of a patient's government-defined residency status with treatment success and loss to follow-up categories at baseline and performed a comparative interrupted time series (ITS) analysis to assess the impact of community-based adherence support on treatment outcomes. Key measures of interest of the ITS were the differences in step change (β) and post-intervention trend (β).
RESULTS
Short-term, inter-province migrants experienced lower treatment success (aRR = 0.95 [95% CI: 0.92-0.99], p = 0.010) and higher loss to follow-up (aOR = 1.98 [95% CI: 1.44-2.72], p  55 years of age (aRR = 0.93 [95% CI: 0.89-0.96], p < 0.001), relapse patients (aRR = 0.89 [95% CI: 0.84-0.94], p < 0.001), and retreatment patients (aRR = 0.62 [95% CI: 0.52-0.75], p < 0.001) had lower treatment success rates. TB/HIV co-infection was also associated with lower treatment success (aRR = 0.77 [95% CI: 0.73-0.82], p < 0.001) and higher loss to follow-up (aOR = 2.18 [95% CI: 1.55-3.06], p < 0.001). The provision of treatment adherence support increased treatment success (IRR(β) = 1.07 [95% CI: 1.00, 1.15], p = 0.041) and reduced loss to follow-up (IRR(β) = 0.17 [95% CI: 0.04, 0.69], p = 0.013) in the intervention districts. Loss to follow-up continued to decline throughout the post-implementation period (IRR(β) = 0.90 [95% CI: 0.83, 0.98], p = 0.019).
CONCLUSIONS
Economic migrants, particularly those crossing provincial borders, have higher risk of poor treatment outcomes and should be prioritized for tailored adherence support. In light of accelerating urbanization in many regions of Asia, implementation trials are needed to inform evidence-based design of strategies for this vulnerable population
Transformation Chlorophyll a of Spirulina platensis to Chlorin e6 Derivatives and Several Applications
BACKGROUND: Spirulina platensis contains a large amount of chlorophylls, chlorophyll a, that are starting materials to synthesize functionalized chlorins. Chlorin e6 (Ce6) as well as its derivatives are second generation sensitizers using in photodynamic therapy (PDT) of various cancers. In this study, we transfer chlorophyll a of S. platensis to Ce6derivatives and determine their several applications.
AIM: to evaluate the effects of Ce6 derivatives to treat cancer cells.
METHODS: Ce6 trimethylester was created from methyl pheophorbide a2 in S. platensis provided by the Hidumi Company, Nghe An province, Viet Nam. Hela cells were incubated with Ce6 trimethylester and the irradiated with the diode laser dose of 1.2 J/cm2/min through the system of filters £ 650 nm. MTT assay and clonogenic assay were used to determine survival rate and cloning efficiency of cells. Antimicrobial effect of Ce6 trimethylester with halogen light were studied with Propionibacterium acnes VTCC 0218 and Staphylococcus aureus VTCC 0173.
RESULTS: From dry biomass (700 g) of S. platensis, after extracting chlorophyll a and methanolysis, 4.2 g of methyl pheophorbide a was obtained. The reaction to give Ce6 trimethylester with 82% yield was performed with potassium hydroxide (KOH) in MeOH/THF/CHCl3. After irradiation with a 650 nm laser at 1.2 J, the cell viability in all samples decreased with Ce6 trimethylester treatment, the survival declining trend of Hela cells treated with Ce6 trimethylester were proportional when concentration of Ce6 trimethylester increased. The rate of colony formation was declined as the concentration of Ce6 trimethylester treated was increased. The growth of both S. aureus and P. acnes can be inactivated by Ce6 trimethylester PDT. The MIC99 value against P. acnes VTCC 0218 and S. aureus VTCC 0173 of Ce6 trimethylester with halogen light was 1.25 μg/ml.
CONCLUSION: The Ce6 trimethylester from S. platensis cultivated in Viet Nam could be used as a potential photosentizer for photodynamic therapy for treatment of cancer and acne
Factors Influence on Promotion Mix in E-marketing: Case of Technology Services Enterprise in Vietnam
Purpose: The objective of this study is to clarify factors affecting the promotion mix in E-Marketing, with specific target audience being enterprises operating in the technology service industry in Vietnam.
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Theoretical framework: Based on the promotion theory and social exchange theory, this study focuses on the factors that influence on the promotion decision in firms.
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Design/Methodology/Approach: This study applies both qualitative and quantitative methods with data collected from a questionnaire survey.
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Findings: There are 4 factors respectively Sales Promotion, Advertising, Public Relations and Personal Selling that affect the mixed promotion activities in E-Marketing of technology service enterprises in Vietnam.
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Research, practical & social implications: This study propose solutions to improve the promotion activities in the e – marketing of firms in Vietnam.
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Originality/Value: This study is one of the early studies that have focused in this field in Vietnam.Propósito: El objetivo de este estudio es aclarar los factores que afectan la combinación de promoción en E-Marketing, con un público objetivo especÃfico que son las empresas que operan en la industria de servicios de tecnologÃa en Vietnam.
Marco teórico: Basado en la teorÃa de la promoción y la teorÃa del intercambio social, este estudio se centra en los factores que influyen en la decisión de promoción en las empresas.
Diseño/metodologÃa/enfoque: este estudio aplica métodos cualitativos y cuantitativos con datos recopilados de una encuesta de cuestionario.
Hallazgos: Existen 4 factores, respectivamente, Promoción de Ventas, Publicidad, Relaciones Públicas y Ventas Personales que afectan las actividades mixtas de promoción en E-Marketing de las empresas de servicios de tecnologÃa en Vietnam.
Implicaciones de investigación, prácticas y sociales: este estudio propone soluciones para mejorar las actividades de promoción en el marketing electrónico de las empresas en Vietnam.
Originalidad/valor: Este estudio es uno de los primeros que se han centrado en este campo en Vietnam.Objetivo: O objetivo deste estudo é esclarecer os fatores que afetam o mix de promoção no E-Marketing, tendo como público-alvo especÃfico as empresas que operam no setor de serviços de tecnologia no Vietnã..
Referencial teórico: Com base na teoria da promoção e na teoria das trocas sociais, este estudo se concentra nos fatores que influenciam a decisão de promoção nas empresas..
Desenho/metodologia/abordagem: Este estudo aplica métodos qualitativos e quantitativos com dados coletados de uma pesquisa por questionário.
Resultados: Existem 4 fatores, respectivamente, Promoção de Vendas, Publicidade, Relações Públicas e Vendas Pessoais que afetam as atividades de promoção mista em E-Marketing de empresas de serviços de tecnologia no Vietnã.
Pesquisa, implicações práticas e sociais: Este estudo propõe soluções para melhorar as atividades de promoção no e – marketing de empresas no Vietnã.
Originalidade/valor: Este estudo é um dos primeiros estudos que se concentraram neste campo no Vietnã.
Palavras-chave: Mix de promoção; E-Marketing; Serviços de tecnologia; Vietn
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