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1.
Am J Clin Pathol ; 147(4): 427-431, 2017 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-28340123

RESUMEN

OBJECTIVES: In 2012, the Vietnam Ministry of Health sought to improve the quality of health laboratories by introducing international quality standards. METHODS: Strengthening Laboratory Management Toward Accreditation (SLMTA), a year-long, structured, quality improvement curriculum (including projects and mentorship) was piloted in 12 laboratories. Progress was measured using a standardized audit tool (Stepwise Laboratory Quality Improvement Process Towards Accreditation). RESULTS: All 12 pilot laboratories (a mix of hospital and public health) demonstrated improvement; median scores rose from 44% to 78% compliance. The public health laboratory in Hai Duong Province entered the program with the lowest score of the group (28%) yet concluded with the highest score (86%). Five months after the completion of the program, without any additional external support, they were accredited. Laboratory management/staff describe factors key to their success: support from the facility senior management, how-to guidance provided by SLMTA, support from the site mentor, and strong commitment of laboratory staff. CONCLUSIONS: Hai Duong preventive medical center is one of only a handful of laboratories to reach accreditation after participation in SLMTA and the only laboratory to do so without additional support. Due to the success seen in Hai Duong and other pilot laboratories, Vietnam has expanded the use of SLMTA.


Asunto(s)
Acreditación , Laboratorios/normas , Personal de Laboratorio/educación , Humanos , Laboratorios/organización & administración , Personal de Laboratorio/normas , Control de Calidad , Mejoramiento de la Calidad , Estándares de Referencia , Vietnam
2.
J Biomed Biotechnol ; 2012: 262670, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23093839

RESUMEN

Juvenile common carp (Cyprinus carpio) were used as a model to investigate acute toxicity and oxidative stress caused by silver nanoparticles (Ag-NPs). The fish were exposed to different concentrations of Ag-NPs for 48 h and 96 h. After exposure, antioxidant enzyme levels were measured, including glutathione-S-transferase (GST), superoxidase dismutase, and catalase (CAT). Other biochemical parameters and histological abnormalities in different tissues (i.e., the liver, gills, and brain) were also examined. The results showed that Ag-NPs agglomerated in freshwater used during the exposure experiments, with particle size remaining <100 nm. Ag-NPs had no lethal effect on fish after 4 days of exposure. Biochemical analysis showed that enzymatic activities in the brain of the fish exposed to 200 µg/L of Ag-NPs were significantly reduced. Varied antioxidant enzyme activity was recorded in the liver and gills. Varied antioxidant enzyme activity was recorded for CAT in the liver and GST in the gills of the fish. However, the recovery rate of fish exposed to 200 µg/L of Ag-NPs was slower than when lower particle concentrations were used. Other biochemical indices showed no significant difference, except for NH(3) and blood urea nitrogen concentrations in fish exposed to 50 µg/L of Ag-NPs. This study provides new evidence about the effects of nanoparticles on aquatic organisms.


Asunto(s)
Antioxidantes/metabolismo , Carpas/fisiología , Ácido Cítrico/química , Nanocápsulas/toxicidad , Estrés Oxidativo/efectos de los fármacos , Plata/toxicidad , Animales , Ensayo de Materiales
3.
Arch Environ Contam Toxicol ; 59(1): 147-56, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19967346

RESUMEN

This study investigated the sorption capacity of estrogenic compounds-such as estrone (E1), 17beta-estradiol (E2), and 17alpha-ethynylestradiol (EE2)-of different sediment particle fractions. Two-sized fractions of sediment were used in the experiments, with a particle size <1 microm (mostly from 450 to 800 nm) and >1 microm up to 50 microm. Sorption kinetics were followed using a two-step reaction in which the major amount of chemicals was sorbed rapidly within minutes and then gradually increased until equilibrium was reached after 48 h. The sorption capacity of the fine particle fraction (particle size <1 microm) was shown to be significantly higher than that of the large fraction (1 microm < particle size < 50 microm). The sorption kinetics and isotherm were adequately predicted by using a pseudo second-order model and the Freundlich equation, respectively. Total organic carbon (TOC) content and surface area of particle fractions were also measured. Although the effects of TOC on the sorption of estrogens could not be verified, a higher surface area of fine particle fractions may significantly increase sorption capacity to target compounds. Sorption of estrogens onto sediment particles could be used to explain the differences of estrogenic activity of E2 spiked into different size fractions of particle suspensions.


Asunto(s)
Estrógenos/química , Sedimentos Geológicos/química , Oryzias/metabolismo , Vitelogeninas/metabolismo , Contaminantes Químicos del Agua/química , Absorción , Adsorción , Animales , Estrógenos/toxicidad , Cinética , Masculino , Tamaño de la Partícula , Contaminantes Químicos del Agua/toxicidad
4.
Chemosphere ; 76(3): 395-401, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19361834

RESUMEN

The effects of particle size on the bioavailability of estrogenic chemicals in the sediments from the Yeongsan River and its tributaries in South Korea were evaluated for 2006 and 2007. Samples for chemical analysis and bioassays were collected from 6 sampling sites during both dry and rainy seasons. The pore water of the sediment samples was extracted, and estrogenic chemicals were eluted using a liquid-liquid extraction (LLE) method. Concentrations of 4-nonylphenol (NP), 4-tert-octylphenol (OP), bisphenol A (BPA), estrone (E1), 17beta-estradiol (E2), 17 alpha-ethynylestradiol (EE2) and genistein (Gen) were analyzed by gas chromatography-mass spectrometry (GC-MS). To evaluate bioavailability, hepatic vitellogenin (Vtg) concentrations of male Japanese medaka were measured after exposure to the sediment or its fractions for 7d. NP, BPA and E2 were detected in all the sediment sample extracts from the Yeongsan River and its tributaries. The concentrations of NP in the sedimentary samples ranged from 60 to 400 ngg(-1) on a dry weight basis. Similarly, OP and E2 were detected in nearly all the sediment extracts, with concentrations of 13 and 26 ngg(-1), respectively. According to the bioassay test results, all the sediment samples significantly induced Vtg in male fish after 7d of exposure. Fractionation of sediments into different size-classes (i.e., particle size >1 microm, particle size <1 microm) eliminated bioavailable estrogenic activity, but fine particles of less than 1microm in size increased the absorption of E2 from E2-amended sediment particle fractions. Consequently, the study suggested that the presence of particles and its interaction in the water environment might change the bioavailability of estrogenic chemicals.


Asunto(s)
Estrógenos/química , Sedimentos Geológicos/química , Contaminantes del Suelo/química , Animales , Disponibilidad Biológica , Monitoreo del Ambiente , Estrógenos/análisis , Masculino , Oryzias/metabolismo , Tamaño de la Partícula , Ríos , Contaminantes del Suelo/análisis , Vitelogeninas/análisis
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