RESUMEN
A new Certified Reference Material (CRM) for radionuclides in sediment (IAEA-385) is described and the results of the certification process are presented. Eleven radionuclides ((40)K, (137)Cs, (226)Ra, (228)Ra, (230)Th, (232)Th, (234)U, (238)U, (238)Pu, (239+240)Pu and (241)Am) have been certified and information mass activities with 95% confidence intervals are given for seven other radionuclides ((90)Sr, (210)Pb((210)Po), (235)U, (239)Pu, (240)Pu and (241)Pu). Results for less frequently reported radionuclides ((60)Co, (99)Tc, (134)Cs, (155)Eu, (224)Ra and (239)Np) and information on some activity and mass ratios are also reported. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in sediment samples, for the development and validation of analytical methods and for training purposes.
Asunto(s)
Sedimentos Geológicos/análisis , Guías de Práctica Clínica como Asunto , Monitoreo de Radiación/normas , Radioisótopos/análisis , Radioisótopos/normas , Irlanda , Océanos y Mares , Dosis de Radiación , Valores de ReferenciaRESUMEN
This paper describes a novel quartz crystal sensor for measurement of the density-viscosity product of Newtonian liquids. The sensor element consists of two piano-convex AT-cut quartz crystals vibrating in a thickness-shear mode with the liquid sample in between. This special set-up allows suppression of disturbing resonances in the liquid layer. Such resonances are generated in the common single-plate arrangements due to compressional waves caused by spurious out-of-plane displacements of the shear vibrating finite plate. The primary measurands of the sensor are the fundamental resonance frequency and the associated resonance Q-value, which are influenced by the viscously entrained liquid contacting the quartz surface. The sensor allows the measurement of samples with viscosities from almost zero (air!) up to 200 cP with a sample volume of 130 microl.
RESUMEN
1. Depression has a prevalence and incidence of significance affecting the morbidity and mortality of the population as a whole and the work force in particular. A variety of risk factors are associated with depression. Certain drugs and conditions may bring on or mimic depression. 2. The symptoms of a major depressive episode, taken as a whole, have certain objective, definable characteristics. Several classes of drugs are used in the treatment of depression. 3. There are a variety of theories regarding the pathophysiology of depression. The various classes of drugs have mechanisms of action which attempt to address aspects of these theories. 4. The ideal antidepressant drug has a number of qualities, some of which are shared by current medications. None of the currently available antidepressants has all of the ideal drug's properties.
Asunto(s)
Antidepresivos/uso terapéutico , Trastorno Depresivo/tratamiento farmacológico , Contraindicaciones , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/etiología , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Selección de Paciente , Factores de RiesgoRESUMEN
1. The new drugs approved by the Food and Drug Administration during 1990 are presented. 2. The pharmacologic actions, indications, dosages, precautions, and adverse reactions of selected new medications are considered. 3. The occupational health nurse can use this information to help clients understand and follow drug treatment plans.