Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Front Public Health ; 8: 605133, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33363097

RESUMEN

"General-purpose cohorts" in epidemiology and public health are designed to cover a broad scope of determinants and outcomes, in order to answer several research questions, including those not defined at study inception. In this context, the general objective of the CONSTANCES project is to set up a large population-based cohort that will contribute to the development of epidemiological research by hosting ancillary projects on a wide range of scientific domains, and to provide public health information. CONSTANCES was designed as a randomly selected sample of French adults aged 18-69 years at study inception; 202,045 subjects were included over an 8-year period. At inclusion, the selected participants are invited to attend one of the 24 participating Health Prevention Centers (HPCs) for a comprehensive health examination. The follow-up includes a yearly self-administered questionnaire, and a periodic visit to an HPC. Procedures have been developed to use the national healthcare databases to allow identification and validation of diseases over the follow-up. The biological collection (serum, lithium heparinized plasma, EDTA plasma, urine and buffy coat) began gradually in June 2018. At the end of the inclusions, specimens from 83,000 donors will have been collected. Specimens are collected according to a standardized protocol, identical in all recruitment centers. All operations relating to bio-banking have been entrusted by Inserm to the Integrated Biobank of Luxembourg (IBBL). A quality management system has been put in place. Particular attention has been paid to the traceability of all operations. The nature of the biological samples stored has been deliberately limited due to the economic and organizational constraints of the inclusion centers. Some research works may require specific collection conditions, and can be developed on request for a limited number of subjects and in specially trained centers. The biological specimens that are collected will allow for a large spectrum of biomarkers studies and genetic and epigenetic markers through candidate or agnostic approaches. By linking the extensive data on personal, lifestyle, environmental, occupational and social factors with the biomarker data, the CONSTANCES cohort offers the opportunity to study the interplays between these factors using an integrative approach and state-of-the-art methods.


Asunto(s)
Bancos de Muestras Biológicas , Adolescente , Adulto , Anciano , Estudios de Cohortes , Bases de Datos Factuales , Humanos , Luxemburgo , Persona de Mediana Edad , Encuestas y Cuestionarios , Adulto Joven
2.
J Ind Microbiol Biotechnol ; 35(8): 815-24, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18427849

RESUMEN

The objective of this work was to develop a hydrogel-coated monolith for the entrapment of penicillin G acylase (E. coli, PGA). After screening of different hydrogels, chitosan was chosen as the carrier material for the preparation of monolithic biocatalysts. This protocol leads to active immobilized biocatalysts for the enzymatic hydrolysis of penicillin G (PenG). The monolithic biocatalyst was tested in a monolith loop reactor (MLR) and compared with conventional reactor systems using free PGA, and a commercially available immobilized PGA. The optimal immobilization protocol was found to be 5 g l(-1) PGA, 1% chitosan, 1.1% glutaraldehyde and pH 7. Final PGA loading on glass plates was 29 mg ml(-1) gel. For 400 cpsi monoliths, the final PGA loading on functionalized monoliths was 36 mg ml(-1) gel. The observed volumetric reaction rate in the MLR was 0.79 mol s(-1) m(-3) (monolith). Apart from an initial drop in activity due to wash out of PGA at higher ionic strength, no decrease in activity was observed after five subsequent activity test runs. The storage stability of the biocatalysts is at least a month without loss of activity. Although the monolithic biocatalyst as used in the MLR is still outperformed by the current industrial catalyst (immobilized preparation of PGA, 4.5 mol s(-1) m(-3) (catalyst)), the rate per gel volume is slightly higher for monolithic catalysts. Good activity and improved mechanical strength make the monolithic bioreactor an interesting alternative that deserves further investigation for this application. Although moderate internal diffusion limitations have been observed inside the gel beads and in the gel layer on the monolith channel, this is not the main reason for the large differences in reactor performance that were observed. The pH drop over the reactor as a result of the chosen method for pH control results in a decreased performance of both the MLR and the packed bed reactor compared to the batch system. A different reactor configuration including an optimal pH profile is required to increase the reactor performance. The monolithic stirrer reactor would be an interesting alternative to improve the performance of the monolith-PGA combination.


Asunto(s)
Enzimas Inmovilizadas/metabolismo , Proteínas de Escherichia coli/metabolismo , Penicilina Amidasa/metabolismo , Penicilina G/metabolismo , Reactores Biológicos , Quitosano , Hidrogeles/química , Concentración de Iones de Hidrógeno , Hidrólisis , Microesferas , Factores de Tiempo
3.
J Chromatogr A ; 908(1-2): 273-91, 2001 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-11218130

RESUMEN

Multicomponent adsorption data of a fermentation broth containing adipoyl-7-amino-3-deacetoxycephalosporanic acid (adipoyl-7-ADCA), a cephalosporin precursor for 7-ADCA, and two key impurities, alpha-hydroxyadipoyl-7-ADCA and alpha-aminoadipoyl-7-ADCA were obtained from batch equilibrium and frontal chromatography tests. Amberlite XAD-1600 was chosen as the resin. A rate model was applied to simulate the chromatograms. An alkaline buffer, which by itself has no affinity for the resin, was used as the eluent. The widely used reversed-phase modulator model is inaccurate in explaining the stepwise elution data. A new model, the induced competition model, has been developed to account for apparent retention of the buffer in the presence of adsorbed species. Close agreement between the simulations and the data was achieved with the new model.


Asunto(s)
Cefalosporinas/aislamiento & purificación , Cefalosporinas/metabolismo , Adsorción , Medios de Cultivo , Fermentación , Modelos Químicos
4.
Rofo ; 151(3): 311-6, 1989 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-2552524

RESUMEN

The natural history of scoliosis, or lateral curvature of the spine, was followed up in 135 patients (111 girls, 24 boys) for a total average period of 52.4 months. We observed patients with a curvature of between 5 degrees and 30 degrees none of whom had been treated specifically as orthotics or with electrical stimulation or by surgery. Two groups of patients with progressive curvature were differentiated: 1) in 62.2% of the patients the curvature progressed by more than 5 degrees during the entire observation period; 2) in 36% of the patients we found an increase in curvature by more than 5 degrees within one year. Another result of our study was that idiopathic scoliosis is particularly dangerous in young patients with a "0" Risser sign. Thoracic curvatures and double major curvatures were more liable to progress than lumbar and thoracolumbar curvatures. Even a small angle of curvature in young patients must be taken seriously.


Asunto(s)
Escoliosis/diagnóstico por imagen , Adolescente , Envejecimiento , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Pronóstico , Radiografía , Caracteres Sexuales , Columna Vertebral/diagnóstico por imagen
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...