RESUMEN
BACKGROUND: Substance abuse is a serious problem, because it affects both workers and young people. Prevalence and consequences of cannabis abuse among construction workers in particular are not well studied in Egypt. OBJECTIVES: To determine the association between non-fatal occupational injuries among construction workers and their demographic and occupational factors and to assess the frequency of cannabis abuse and its relationship to injury severity and workdays lost. SUBJECTS AND METHODS: A case-control study was conducted at Mansoura Emergency Hospital. Cases were 100 acutely injured male workers. A control group of 90 healthy age-matched workers was selected from 8 construction sites. Workers were interviewed, and a questionnaire was completed that included socio-demographic data, full occupational history, and causes and type of injury. Injury outcome measures included lost workdays and the injury severity score (ISS). Cannabis abuse in injured workers was monitored by preliminary testing of urine and confirmatory testing of blood. RESULTS: Logistic regression analysis revealed that the independent predictors of occupational injuries were rural residence, being a carpenter or painter and past history of injuries. The most common accidents were slipping falls (62%). Confirmed cannabis test was positive in 51.1% of the injured workers. Median days away from work were greater among cannabis users than non-users. The ISS was significantly higher among users compared to non-users ( p < 0.05). CONCLUSION: Cannabis abuse can increase injury severity and prolong workdays lost. Drug testing is recommended for at-risk construction workers with inadequate safety measures.
Asunto(s)
Accidentes de Trabajo , Industria de la Construcción , Abuso de Marihuana/fisiopatología , Traumatismos Ocupacionales/etiología , Accidentes por Caídas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Causalidad , Egipto/epidemiología , Servicio de Urgencia en Hospital , Hospitales Universitarios , Humanos , Puntaje de Gravedad del Traumatismo , Masculino , Abuso de Marihuana/epidemiología , Abuso de Marihuana/terapia , Abuso de Marihuana/orina , Persona de Mediana Edad , Traumatismos Ocupacionales/epidemiología , Traumatismos Ocupacionales/terapia , Traumatismos Ocupacionales/orina , Prevalencia , Reinserción al Trabajo , Factores de Riesgo , Autoinforme , Detección de Abuso de Sustancias , Recursos Humanos , Adulto JovenRESUMEN
Transmission of compressed medical images is becoming a vital tool in telemedicine. Thus new methods are needed for efficient image compression. This study discovers the best design parameters for a data compression scheme applied to digital magnetic resonance (MR) images. The proposed technique aims at reducing the transmission cost while preserving the diagnostic information. By selecting the wavelet packet's filters, decomposition level, and subbands that are better adapted to the frequency characteristics of the image, one may achieve better image representation in the sense of lower entropy or minimal distortion. Experimental results show that the selection of the best parameters has a dramatic effect on the data compression rate of MR images. In all cases, decomposition at three or four levels with the Coiflet 5 wavelet (Coif 5) results in better compression performance than the other wavelets. Image resolution is found to have a remarkable effect on the compression rate.
Asunto(s)
Imagen por Resonancia Magnética/métodos , Encéfalo/anatomía & histología , Computadores , Estudios de Evaluación como Asunto , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Procesamiento de Imagen Asistido por Computador/estadística & datos numéricos , Imagen por Resonancia Magnética/estadística & datos numéricos , TelemedicinaRESUMEN
Lactase preparations were purified from cell-free extracts of Kluyveromyces lactis to homogeneity, as determined by disc SDS polyacrylamide gel electrophoresis. A combination of techniques including ammonium sulfate or acetone precipitation and hydroxyapatite chromatography was used for the purification of the enzyme. The enzyme has a pH optimum of 6.5-7.0 with Kms' of 1.25 and 28mM for the substrates O-nitrophenylgalactopyranoside and lactose respectively. Activation energies for denaturation of enzyme and conversion of substrate to product were determined to be 15.1 and 10.0 Kcal/mol, respectively. When reconstituted skim milk containing 20% total solids was treated with the lactase preparation (60,000 lactase units/1 of milk) at 18°C, 82% of the milk lactose was hydrolyzed within 24 h. Such treatment lends itself for application in developing countries and where the incidence of lactose intolerance is high.