RESUMO
Vietnam has a concentrated HIV epidemic, with the highest HIV prevalence being observed among people who inject drugs (PWID). Based on its experience scaling-up robust HIV interventions, Vietnam aims to further strengthen its response by harnessing the preventive benefits of antiretroviral therapy (ART). Mathematical modelling suggests that prioritizing key populations for earlier access to ART, combined with other prevention interventions, may have significant impact on the epidemic, cost-effectively reducing new HIV infections and deaths. Pilot studies are being conducted to assess feasibility and acceptability of expansion of HIV testing and counselling (HTC) and early ART among key populations and to demonstrate innovative service delivery models to address challenges in uptake of services across the care cascade. Earlier access of key populations to combination prevention interventions, combined with sustained political commitment and supportive environment for key populations, are essential for maximum impact of ART on the HIV epidemic in Vietnam.
Assuntos
Antirretrovirais/uso terapêutico , Infecções por HIV/prevenção & controle , Antirretrovirais/economia , HIV/patogenicidade , Infecções por HIV/epidemiologia , Humanos , Modelos Teóricos , Vietnã/epidemiologiaRESUMO
Magnetite nanoparticles (Fe3O4 NPs) are among the most effective Fenton-Like heterogeneous catalysts for degrading environmental contaminants. However, Fe3O4 NPs aggregate easily and have poor dispersion stability because of their magnetic properties, which seriously decrease their catalytic efficiency. In this study, a novel environmentally friendly method for synthesising Fe3O4@CA was proposed. Fe3O4 NPs were immobilized on the 3D cellulose aerogels (CAs) in order to augment the degradation efficiency of p-nitrophenol (PNP) treatment and make the separation of the catalyst accessible by vacuum filtration method. Besides, CAs were fabricated from a cellulose source extracted from water hyacinth by using different cross-linking agents, such as kymene (KM) and polyvinyl alcohol-glutaraldehyde system (PVA-GA), and other drying methods, including vacuum thermal drying and freeze drying, were evaluated in the synthesis process. As-synthesized samples were analysed by various methods, including Powder X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray analysis and Brunauer-Emmett-Teller. Then, using ultraviolet-visible spectroscopy, the difference in the degradability of PNP of the obtained material samples was also investigated to determine their potential applications. Results highlighted that the Fe3O4-3@CA-KF catalyst with an Fe3O4 loading of 0.40 g/gCA used KM as a cross-linker and the freeze-drying method demonstrated the highest PNP removal efficiency (92.5 %) in all Fe3O4@CA samples with a H2O2 content of 5 g/L. The degradation kinetics and well-fitted pseudo-first-order model were investigated. Notably, after five successive PNP degradation experiments, this catalyst retained â¼80 % of the ability to degrade PNP, indicating its outstanding reusability. In environmental remediation, this study provides valuable insights into the development of simply separated and high-efficiency catalysts for heterogeneous catalytic reactions.
RESUMO
Antiretroviral therapy (ART) retention and 5 early-warning indicators (EWIs) of HIV drug resistance (HIVDR) were abstracted at 27 adult and 4 pediatric clinics in Vietnam in 2009. Of 4531 adults and 313 children, 81.2% and 84.4% respectively were still on ART at 12 months. More than 90% of the clinics monitored achieved the World Health Organization (WHO) targets for lost-to-follow-up (LTFU), ART prescribing practices, and ARV supply continuity. Only 83.9% of the clinics met the target for first-line ART retention and 79.3% met the target for clinic appointment-keeping. Clinic factors (i.e. number of patients, administrative level, and geographical region) were associated with ART retention and LFTU. Data were useful in guiding public health action to optimize ART services.
Assuntos
Antirretrovirais/farmacologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Adulto , Instituições de Assistência Ambulatorial/estatística & dados numéricos , Antirretrovirais/provisão & distribuição , Antirretrovirais/uso terapêutico , Criança , Estudos de Coortes , Farmacorresistência Viral , Humanos , Perda de Seguimento , Programas Nacionais de Saúde , Razão de Chances , Cooperação do Paciente/estatística & dados numéricos , Vigilância da População , Vietnã/epidemiologia , Organização Mundial da SaúdeRESUMO
Viral hepatitis is a disease of great concern to public health that is now met by a favorable momentum to combat the global epidemic. This article is intended to highlight the importance of viral hepatitis in the Vietnam population as well in the group of people living with HIV/AIDS (PLWHA). We reviewed available data on epidemiology and response on hepatitis B virus (HBV) and hepatitis C virus (HCV) and HIV coinfection in Vietnam. The hepatitis B surface antigen (HBsAg) prevalence in the general population ranged from 5.7% to 24.7%. The anti-HCV prevalence ranged from 0.38% to 4.3% in the general population, while among people who inject drugs (PWIDs) it ranged from 31% to 97.2%. The HBV prevalence among PLWHA is similar to the general population, while HCV/HIV coinfection is concentrated in some groups. Anti-HCV prevalence among HIV-infected PWIDs can be as high as 98.5%. Developing policies for diagnosis and treatment of chronic HBV and HCV infections are critical priorities in order to prevent clinical progression to cirrhosis and liver cancer.
Assuntos
Anticorpos Antivirais/sangue , Coinfecção/epidemiologia , Infecções por HIV/epidemiologia , Hepacivirus/imunologia , Hepatite B/epidemiologia , Hepatite C/epidemiologia , Feminino , Hepatite B/diagnóstico , Hepatite B/tratamento farmacológico , Hepatite B/prevenção & controle , Antígenos de Superfície da Hepatite B/sangue , Hepatite C/diagnóstico , Hepatite C/tratamento farmacológico , Hepatite C/prevenção & controle , Homossexualidade Masculina , Humanos , Masculino , Prevalência , Profissionais do Sexo , Abuso de Substâncias por Via Intravenosa/sangue , Abuso de Substâncias por Via Intravenosa/virologia , Vietnã/epidemiologiaRESUMO
Hydroxyapatite (HA) derived from salmon bone byproducts is used as a green support for the nanostructured nickel catalysts applied in the methanation of carbon dioxide (CO2). Undoped nickel catalysts and various ceria-doped nickel supported on hydroxyapatite (HA) were prepared by coimpregnation. Characteristics of the as-prepared catalysts were investigated by the various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), hydrogen temperature-programmed reduction (H2-TPR), carbon dioxide temperature-programmed desorption (CO2-TPD), and energy-dispersive X-ray spectroscopy (EDX). The catalyst activity was assessed throughout CO2 methanation in the low-temperature range of 225-350 °C with the molar ratio of H2/CO2 = 4/1. The function of HA and ceria provided a high dispersity of nickel particles over the catalyst surface with the size range of 24.5-25.8 nm, leading to improvement in the reduction and CO2 adsorption capacity of the catalysts as well as enhancing the catalytic efficiency in CO2 methanation. The 10Ni/HA catalyst reduced at suitable conditions of 400 °C for 2 h showed the highest catalytic performance among the tested catalysts. CO2 conversion and CH4 selectivity reached 76.6 and 100% at a reaction temperature of 350 °C, respectively. The results show that the Ni/HA sample doped with 6.0 wt % ceria was the best, with the CO2 conversion and the CH4 selectivity reaching 92.5% and 100%, respectively, at a reaction temperature of 325 °C.
RESUMO
A green synthesis using extract from Citrus maxima peel was developed to fabricate Au-Ce catalysts for the reduction of p-nitrophenol (PNP). Au nanoparticles with a diameter of 6.6 ± 2.5 nm were deposited onto the surface of CeO2 nanorods with a length of 33.1 ± 15.0 nm and a diameter of 7.1 ± 2.1 nm. The mesoporous and non-porous capillary structures of these materials were observed. The interaction between Au and CeO2 increased the specific surface area, pore diameter, and pore volume compared with pure CeO2 (90 m2 g-1, 23.8 Å, and 0.110 cm3 g-1 versus 72 m2 g-1, 23.0 Å, and 0.089 cm3 g-1). The splitting peaks of the surface oxygen and their shifting at lower temperatures compared with CeO2 nanorods were found thanks to the Au-CeO2 interaction, suggesting that their reduction occurred more easily. The synthesized Au-Ce catalysts exhibited excellent activity in the reduction of PNP to p-aminophenol. The 0.2Au-Ce catalyst was the most efficient one for PNP reduction, enabling the conversion of PNP in 30 minutes with a catalyst concentration of 20 mg L-1 and a PNP/NaBH4 molar ratio of 1/200. Moreover, the 0.2Au-Ce catalyst could be reused for at least five consecutive cycles without considerable loss of its activity.
RESUMO
Cellulosic aerogel from water hyacinth (WH) was synthesized to address the dual environmental issues of water hyacinth pollution and the production of a green material. Raw WH was treated with sodium hydroxide (NaOH) with microwave assistance and in combination with hydrogen peroxide (H2O2). The results from X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) showed that lignin and hemicellulose were markedly decreased after treatment, reducing from 24.02% hemicellulose and 5.67% lignin in raw WH to 8.32 and 1.92%, respectively. Cellulose aerogel from the pretreated WH had a high porosity of 98.8% with a density of 0.0162 g·cm-3 and a low thermal conductivity of 0.030 W·m-1·K-1. After modification with methyl trimethoxysilane (MTMS) to produce a highly hydrophobic material, WH aerogel exhibited high stability for oil absorption at a capacity of 43.3, 43.15, 40.40, and 41.88 (g·g-1) with diesel oil (DO), motor oil (MO), and their mixture with water (DO + W and MO + W), respectively. The adsorption remained stable after 10 cycles.
RESUMO
This work demonstrated a simple, low-cost, rapid, and effective biochemical oxygen demand (BOD) estimation system based on a packed-bed bioreactor that can be easily self-built on-site at a particular wastewater treatment plant for continuous monitoring of the influent and effluent. The use of natural microbial consortium that were collected from the target wastewater and immobilized on a cheap porous carrier simply by adhesion resulted in an acceptable accuracy of over 95%. The newly developed semi-continuous operating mode with peak-type signals was shown to be able to continuously estimate BOD at a high flow rate to overcome the flow dependence of the oxygen electrode, limit clogging issues, enhance the response time, and lower the limit of detection. The resulting packed-bed bioreactors could work continuously for 22 h with a coefficient of variance (CoV) of only 1.8% or for 13 h a day for several days with a maximum CoV of 1.4% and their response was observed to be stable over 80 consecutive measurements. They exhibited stable responses at a wide pH range of 6.5-8.5, which is also the recommended range for aerobic wastewater treatment, emphasizing the greater ease of use of natural microorganisms for BOD estimation.
Assuntos
Oxigênio/análise , Águas Residuárias/análise , Reatores Biológicos , Eletrodos , Águas Residuárias/químicaRESUMO
BACKGROUND: The prevention of mother-to-child transmission (PMTCT) of HIV program was introduced in Vietnam in 2005. Despite the scaling up of PMTCT programs, the rate of mother-to-child HIV transmission in Vietnam was estimated as high as 20% in 2013. OBJECTIVE: The objective of this study was to assess the outcomes of PMTCT and identified factors associated with mother-to-child transmission and infant survival using survey and program data in a high HIV burden province in Vietnam. METHODS: This community-based retrospective cohort study observed pregnant women diagnosed with HIV infection in Thai Nguyen province from October 2008 to December 2012. Data were collected through interviews using a structured questionnaire and through reviews of log books and medical charts in antenatal care and HIV clinics. Logistic regression and survival analysis were used to analyze data using Stata (StataCorp). RESULTS: A total of 172 pregnant women living with HIV were identified between 2008 and 2012. Most of these women had acquired the HIV infection from their husband (77/119, 64.7%). Significant improvement in the PMTCT program was documented, including reduction in late diagnosis of HIV for pregnant women from 62.5% in 2008 to 30% in 2012. Access to antiretrovirals (ARVs) improved, increasing from a rate of 18.2% (2008) to 70.0% (2011) for mothers and from 36.4% (2008) to 93.3% (2012) for infants. For infants, early diagnosis within 2 months of birth reached 66.7% in 2012 compared with 16.7% in 2009. Transmission rate reduced from 27.3% in 2008 to 6.7% in 2012. Late diagnosis was associated with increased risk for HIV transmission (odds ratio [OR] 14.7, 95% CI 1.8-121.4, P=.01), whereas ARV therapy for mother and infant in combination with infant formula feeding were associated with reduced risk for HIV transmission (OR 0.01, 95% CI 0.001-0.1; P<.001). Overall survival rate for HIV-exposed infants at 12 months was 97.7%. CONCLUSIONS: A combination of program and survey data measured the impact of prevention of HIV transmission from mother-to-child interventions. Significant improvement in access to the interventions was documented in Thai Nguyen province. However, factors that increased the risk of HIV transmission, such as late diagnosis, remain to be addressed.