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1.
HIV Med ; 25(3): 391-397, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38031396

RESUMEN

INTRODUCTION: Antiretroviral therapy (ART) is integral to HIV prevention, including averting vertical transmission. The World Health Organization (WHO) recommends ART and breastfeeding for all women living with HIV for at least 12 months post-partum [1, 2]. Much of the data on HIV transmission through breastfeeding comes from low-resource settings, with a paucity of data on breastfeeding-related HIV transmission in women living with HIV in other settings. Women Against Viruses in Europe (WAVE), part of the European AIDS Clinical Society (EACS), aims to improve the standard of care for women living with HIV and sought to gain an understanding of breastfeeding guidelines and practice in women living with HIV across Europe. METHODS: A steering group convened by WAVE developed a survey to collate information on breastfeeding trends, practice, and guideline recommendations for women living with HIV in Europe and to establish interest in becoming involved in a collaborative breastfeeding network. The survey was disseminated to 31 countries in March 2022. RESULTS: In total, 25 eligible responses were received: 23/25 (92%) countries have HIV and pregnancy guidelines; 23/23 (100%) guidelines refer specifically to breastfeeding; 12/23 (52%) recommend against breastfeeding; 11/23 (48%) offer an option if certain criteria are met; 12/25 (48%) reported that the number of women living with HIV who breastfeed is increasing; 24/25 (96%) respondents were interested in joining a network on breastfeeding in women living with HIV. CONCLUSIONS: Recommendations vary, and nearly half of the guidelines recommend against breastfeeding. Many countries report an increase in breastfeeding. WAVE will establish a collaborative network to bridge data gaps, conduct research, and improve support for women living with HIV who choose to breastfeed.


Asunto(s)
Lactancia Materna , Infecciones por VIH , Embarazo , Femenino , Humanos , Lactante , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/prevención & control , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Periodo Posparto , Encuestas y Cuestionarios
2.
Int J STD AIDS ; 33(1): 99-102, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34852685

RESUMEN

AIMS: The national PrEP programme launched in Ireland in November 2019 with tenofovir/emtricitabine free to those meeting eligibility criteria. We assessed the impact of the first year of the PrEP programme on new HIV diagnoses in the largest sexual health and HIV service in Ireland. METHODS: A free PrEP service was established in November 2019. We reviewed the number of new diagnoses of HIV between November 2018-2019, before the introduction of the national PrEP programme and compared this with the number of new HIV diagnosis between November 2019-2020. RESULTS: There were 95 new HIV diagnoses (63.3% MSM) between November 2018 and 2019 and 73 new HIV diagnoses (65.7% MSM) between November 2019 and 2020. There was a statistically significant decline in new HIV diagnoses between the 2 years (P = 0.0003). 546 patients were prescribed PrEP as of December 2020.106 patients (19.4%) changed their PrEP dosing regimen due to lockdown. 178 individuals (32.6%) had a rectal infection diagnosed. CONCLUSION: There has been a reduction in new HIV diagnoses in our cohort (although this has occurred during a global pandemic). It is too early to say if PrEP reduces late presentations of HIV based on our findings. A significant number of rectal infections were identified in the PrEP clinic suggesting ongoing risk despite pandemic restrictions. Further research into sexual practices during COVID-19 is needed to assess if this had an impact on the lower rates of HIV acquisition.


Asunto(s)
Fármacos Anti-VIH , COVID-19 , Infecciones por VIH , Profilaxis Pre-Exposición , Minorías Sexuales y de Género , Fármacos Anti-VIH/uso terapéutico , Control de Enfermedades Transmisibles , VIH , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Infecciones por VIH/prevención & control , Homosexualidad Masculina , Humanos , Masculino , Pandemias , SARS-CoV-2
3.
Science ; 151(3709): 453-4, 1966 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-5902387

RESUMEN

Uranium and thorium daughters are ten times more concentrated in thyroids from some bovine animals than in the teeth of the same animals. These radioactive isotopes are believed to be from natural sources, but their resulting annual dosage of thyroid radiation has exceeded that from iodine-131 fallout.


Asunto(s)
Radioisótopos/metabolismo , Radio (Elemento)/metabolismo , Torio/metabolismo , Glándula Tiroides/metabolismo , Diente/metabolismo , Animales , Bovinos , Contaminación Radiactiva de Alimentos , Radiometría
4.
BJR Case Rep ; 5(1): 20170074, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31131113

RESUMEN

We report the case of an 84-year-old male, who presented with septicaemia, abdominal and back pain. The patient had a background of oesophageal carcinoma and had undergone previous oesophagectomy and gastric pull-up operation 10 years ago. A computerised topography scan demonstrated a probable gastro-vertebral communication with a destructive process at the T8/T9 vertebral level. Further evaluation with MRI clearly showed the tract between the two structures and confirmed the diagnosis of spondylodiscitis at the adjacent spinal level. The patient was resuscitated, treated with intravenous antibiotics and kept nil by mouth. A subsequent gastroscopy demonstrated an eroding gastric ulcer at the enteric opening of the tract between the tubal stomach and the spinal column. The diagnosis was discussed with the patient, his family and the surgical multidisciplinary team. Given the extent of disease and his multiple medical co-morbidities, the decision was made for conservative management and symptom control. This is the first case of a gastro-vertebral communication causing spondylodiscitis to be described in the literature.

5.
Biochim Biophys Acta ; 1225(1): 33-8, 1993 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-8241287

RESUMEN

The number of glucose molecules condensed on glycated bovine serum albumin have been easily determined by means of matrix-assisted laser desorption/ionization mass spectrometry. Measurements were carried out on samples from incubation of the protein with glucose at different concentrations (0.02 M, 0.2 M, 2 M and 5 M). A clear increase in molecular mass of BSA with respect to incubation time is detected. In contrast to what is observed with fluorescence, the plots of molecular mass increase vs. incubation time show the occurrence of a steady state, corresponding to the complete saturation of all the protein sites reactive against glucose. Comparison of fluorescence and molecular mass data reveals that some further reactions, different from condensation, must take place, which could be in principle either intramolecular or originated by reactivity of modified condensed glucose moieties vs. free glucose.


Asunto(s)
Glucosa/química , Rayos Láser , Espectrometría de Masas/métodos , Proteínas/química , Glicosilación
6.
Ir Med J ; 98(7): 199-200, 202, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16185014

RESUMEN

Previous research has shown that many general practitioners were experiencing stress levels detrimental to their well-being. To examine coping strategies of Irish general practitioners and the possible impact of their stress on mental health and job satisfaction. Anonymous questionnaires were posted to 226 general practitioners in the Western Health Board. Just over one third of stressors caused moderate to considerable stress. Coping was important in the stress process. Sometimes, coping strategies predicted stress-related outcomes better than stressors. General practitioners' mental health was slightly better than that of a normative group. They tended to be satisfied with all aspects of the job, except hours of work. The provision of counselling services for general practitioners suffering from stress should be encouraged. Stress-management strategies should include training in coping skills and time management. The increased use of co-operatives could help alleviate the stress of out-of-hours work.


Asunto(s)
Adaptación Psicológica , Satisfacción en el Trabajo , Médicos de Familia/psicología , Estrés Psicológico/epidemiología , Femenino , Humanos , Irlanda/epidemiología , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios
7.
Radiat Res ; 147(2): 236-44, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9008216

RESUMEN

This study examined the effect of internal exposure to alpha-particle radiation on subsequent fertility among women employed in the radium dial industry prior to 1930, when appreciable amounts of radium were often ingested through the practice of pointing the paint brush with the lips. The analysis was limited to women for whom a radium body burden measurement had been obtained and who were married prior to age 45 (n = 603). Internal radiation dose to the ovary was calculated based on initial intakes of radium-226 and radium-228, average ovarian mass, number and energy of alpha particles emitted, fraction of energy absorbed within the ovary, effective retention integrals and estimated photon irradiation. Time between marriage and pregnancy, number of pregnancies and number of live births served as surrogates for fertility. Radiation appeared to have no effect on fertility at estimated cumulative ovarian dose equivalents below 5 Sv; above this dose, however, statistically significant declines in both number of pregnancies and live births were observed. These trends persisted after multivariable adjustment for potential confounding variables and after exclusion of subjects contributing a potential classification or selection bias to the study. Additionally, the high-dose group experienced fewer live births than would have been expected based on population rates. There were no differences in time to first pregnancy between high- and low-dose groups. These results are consistent with earlier studies of gamma-ray exposures and suggest that exposure to high doses of radiation from internally deposited radium reduces fertility rather than inducing sterility.


Asunto(s)
Partículas alfa , Fertilidad/efectos de la radiación , Infertilidad Femenina/epidemiología , Exposición Profesional , Pintura/efectos adversos , Dosis de Radiación , Aborto Espontáneo/epidemiología , Administración Oral , Adulto , Anemia/epidemiología , Tasa de Natalidad , Estudios de Cohortes , Comorbilidad , Connecticut/epidemiología , Bases de Datos Factuales , Relación Dosis-Respuesta en la Radiación , Femenino , Estudios de Seguimiento , Fracturas Óseas/epidemiología , Humanos , Hipertensión/epidemiología , Illinois/epidemiología , Recién Nacido , Infertilidad Femenina/etiología , Neoplasias/epidemiología , New Jersey/epidemiología , Paridad , Embarazo , Resultado del Embarazo , Índice de Embarazo , Traumatismos por Radiación/epidemiología
8.
Soc Sci Med ; 38(8): 1055-60, 1994 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8042053

RESUMEN

This paper presents preliminary findings from an ongoing study of survivors of residential fires. The purpose of this study was to examine psychological distress and extent of loss in order to provide a psychological profile of survivors overtime. The sample (N = 69) was drawn consecutively from the database of residential fires available through the Philadelphia Fire Department. Levels of psychological distress were measured as well as reports of symptoms consistent with the diagnostic criteria for Post-traumatic Stress Disorder. The major findings indicate that residential fires caused significant and sustained distress. An agenda for further research and for services to survivors of these fires is presented.


Asunto(s)
Incendios , Vivienda , Trastornos por Estrés Postraumático/epidemiología , Trastornos por Estrés Postraumático/psicología , Adolescente , Adulto , Anciano , Aflicción , Femenino , Humanos , Entrevista Psicológica , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Factores Socioeconómicos , Trastornos por Estrés Postraumático/diagnóstico , Sobrevivientes/psicología
9.
J Biomech ; 33(4): 435-42, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10768392

RESUMEN

A computational model has been developed using a current generation computer-aided engineering (CAE) package to predict total knee replacement (TKR) kinematic in the sagittal plane. The model includes friction and soft tissue restraint varying according to the flexion angle. The model was validated by comparing the outcomes of anterior-posterior (A-P) laxity tests of two contemporary knee replacements against data obtained from a knee simulating machine. It was also validated against predictions from a computer model reported in the literature. Results show good agreement in terms of A-P displacements. Further tests were performed to determined the influence of the soft tissue restraints varying with flexion angle. This work represents the first attempt to use a sophisticated commercial CAE package to predict TKR motions and the advantages of the modelling procedure chosen are discussed.


Asunto(s)
Prótesis de la Rodilla , Modelos Teóricos , Fenómenos Biomecánicos , Predicción , Humanos , Rodilla/fisiopatología
10.
Am J Manag Care ; 5(7): 899-909, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10557410

RESUMEN

CONTEXT: Atrial fibrillation is a common arrhythmia. It leads to significant morbidity and mortality, primarily from the increased incidence of stroke. The implantable atrial defibrillator, a new therapeutic option for the management of atrial fibrillation, is currently undergoing Food and Drug Administration (FDA) scrutiny for approval to market in the United States. DATA SOURCES: A review of the basic epidemiology of atrial fibrillation, as well as the current status of accepted treatment options in light of the development of the implantable atrial defibrillator, was conducted. A literature search using the terms atrial fibrillation, implantable defibrillator, Food and Drug Administration, medical devices, and medical device regulatory law was conducted using the MEDLINE and Current Contents databases. RESULTS: Currently, there is no consensus on the optimal treatment of atrial fibrillation. Despite the lack of definitive studies showing overall benefit associated with maintaining sinus rhythm in patients in atrial fibrillation, the implantable atrial defibrillator may soon reach the general market. We examine the FDA process for the evaluation of this new medical device and discuss implications for the patient, physician, industry, and health insurers. CONCLUSIONS: Current FDA approval processes for new devices are a compromise between (a) the needs for expediency and encouraging innovation by the medical device industry and (b) the need to ensure that new devices will contribute to improved patient outcomes. We suggest alternative FDA-approval processes that address these issues.


Asunto(s)
Fibrilación Atrial/terapia , Desfibriladores Implantables/normas , Aprobación de Recursos/normas , Evaluación de la Tecnología Biomédica/métodos , United States Food and Drug Administration , Ensayos Clínicos como Asunto , Aprobación de Recursos/legislación & jurisprudencia , Seguridad de Equipos , Humanos , Almacenamiento y Recuperación de la Información , Resultado del Tratamiento , Estados Unidos
11.
Br J Gen Pract ; 51(465): 286-90, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11458481

RESUMEN

BACKGROUND: Published research into the provision and utilisation of out-of-hours services shows long-term trends towards decreasing personal commitment among general practitioners (GPs). However, the on-call commitments of rural GPs remain especially onerous. There has been little research relating to either rural out-of-hours services or the implications of such services for the families of the providers. AIM: To explore and describe how rural GPs in Ireland perceive and experience out-of-hours care provision. DESIGN OF STUDY: A qualitative study was conducted with 10 rural GPs and their spouses in their homes or practices using one-to-one in-depth interviews. SETTING: Ten general practices in rural Ireland. METHOD: The interviews were guided by an interview schedule that was based on pertinent themes that had emerged from previous relevant literature. The interviews were audiotaped, transcribed, and analysed for themes and issues. RESULTS: Results indicated that rural GPs experience a wide variety of satisfactions from work related to the provision of out-of-hours care. However, the large proportion of time committed to out-of-hours care greatly infringes on their social and family life. The key stressors identified related to organisational system difficulties, especially with regard to locum cover, and unrealistic patient expectations. The stressors were mainly expressed as lack of time off, restrictions on family life, and interruptions. CONCLUSION: System difficulties, such as difficulty with obtaining locums and rota extension, need to be addressed at an organisational level. Patient expectations of the role of the rural GP have significant implications for practitioners and their families.


Asunto(s)
Actitud del Personal de Salud , Servicios Médicos de Urgencia/organización & administración , Medicina Familiar y Comunitaria/organización & administración , Médicos de Familia/psicología , Servicios de Salud Rural/organización & administración , Adulto , Servicios Médicos de Urgencia/normas , Servicios Médicos de Urgencia/provisión & distribución , Medicina Familiar y Comunitaria/normas , Relaciones Familiares , Femenino , Humanos , Entrevistas como Asunto , Irlanda , Satisfacción en el Trabajo , Masculino , Persona de Mediana Edad , Cuidados Nocturnos/estadística & datos numéricos , Aceptación de la Atención de Salud , Satisfacción del Paciente , Calidad de la Atención de Salud , Servicios de Salud Rural/normas , Servicios de Salud Rural/provisión & distribución , Población Rural , Esposos/psicología
12.
Carbohydr Res ; 266(2): 191-209, 1995 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-7697655

RESUMEN

The hydroxyl groups 3 and 6 of distal galactose units in bi-, tri-, and tetra-antennary asialo-glycans of N-linked complex type were substituted stepwise by transferase reactions with the sequence alpha-D-Galp-(1-->3)-beta-D-Galp-(1-->4)-beta-D-GlcpNAc. The products of each transferase reaction were purified chromatographically and the structures were confirmed by 1H NMR spectroscopy. Molecular weights of the final products were determined by matrix-assisted laser-desorption mass spectrometry (MALDI-MS).


Asunto(s)
Galactosiltransferasas/química , N-Acetilglucosaminiltransferasas/química , Polisacáridos/síntesis química , Secuencia de Carbohidratos , Cromatografía en Papel , Galactosa/química , Humanos , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Datos de Secuencia Molecular , Polisacáridos/química
13.
Am J Crit Care ; 3(3): 232-7, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8038854

RESUMEN

This literature review was done to explore the use of master's-prepared nurse practitioners to manage critically ill patients. Data-based, anecdotal, clinical, analytic, and position papers published over the past 10 years in the medical and nursing literature were reviewed. This article synthesizes findings on the use of nurse practitioners in clinical settings including primary and specialty care settings, describes favorable outcomes of advanced practice nurses, and identifies factors that must be addressed as these roles increase in use in critical care settings. Nurse practitioners' movement into critical care settings should be undertaken. Additional federal support to ensure the preparation of these practitioners in adequate numbers is needed. Attention to issues of direct reimbursement, salaries, impact of changing role boundaries, malpractice coverage, and prescription privileges must be addressed. Research programs to examine the effect of nurse practitioners in specialized care should continue.


Asunto(s)
Cuidados Críticos , Enfermeras Clínicas , Enfermeras Practicantes , Humanos
14.
West J Nurs Res ; 22(3): 263-78; discussion 278-84, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10804892

RESUMEN

This article presents an analysis of the tangible, psychological, and general needs of adults and their children reported by residential fire survivors approximately 14 weeks postfire. Three hundred and seven survivors, who identified that they needed help for themselves or their children, differed from 133 survivors who did not request help. Those needing help were more likely to be women with children younger than age 18 living in their household, have low-income status, less education, and to have already received services from church groups. The classification of self-identified needs of fire survivors included the need for specific tangible and social service assistance, psychological and spiritual support, and nonspecific assistance. This classification contributes to our understanding of the relationship between needs and loss, grief, and changes in family and life situations postfire.


Asunto(s)
Actitud Frente a la Salud , Incendios , Vivienda , Evaluación de Necesidades/clasificación , Sobrevivientes/psicología , Adaptación Psicológica , Adulto , Factores de Edad , Anciano , Niño , Femenino , Pesar , Humanos , Estudios Longitudinales , Masculino , Investigación Metodológica en Enfermería , Factores Sexuales , Apoyo Social , Factores Socioeconómicos
15.
Health Phys ; 44 Suppl 1: 103-12, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-6862890

RESUMEN

This paper examines in humans the proposition emanating from studies in beagles that initial retention of radium varies in proportion to the calcium addition rate at the time of intake. Human calcium addition rates were scaled from those in beagles, the relative calcium accretion rates in the two species at equivalent stages of skeletal growth providing the scaling factor. The variation of radium retention with age was determined by fitting a modified power function to data on the retention of radium from about 30 to 15000 days following a series of therapeutic injections of 226Ra in humans ranging in age from 18 to 63 yr. The fractional retention R at t days following a single injection of 226Ra was described by R = (1 + t/d)-0.44. The age-dependent parameter d in the retention function was found to be proportional to the calcium addition rate at the time of injection in subjects receiving less than 200 micrograms 226Ra.


Asunto(s)
Envejecimiento/efectos de la radiación , Modelos Biológicos , Radio (Elemento)/metabolismo , Adolescente , Adulto , Animales , Calcio/metabolismo , Niño , Preescolar , Perros , Femenino , Humanos , Lactante , Masculino , Matemática , Persona de Mediana Edad , Factores de Tiempo
16.
Health Phys ; 44 Suppl 1: 391-402, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-6862916

RESUMEN

An unusually protracted retention of uranium in the chests of certain workers at a uranium processing plant has been reported in the literature. This finding has implications for the protection of current uranium workers and for health-effects studies of early workers. It is shown that the limited data obtained postmortem that have been reported do not reveal a significant unusually protracted retention of uranium in the pulmonary region or in the tracheobronchial lymph nodes. Probable explanations of the disparate findings are discussed. Data are presented on mortality from cancers of lymphatic tissues among males who worked in the period from 1943 to 1947 at the Y-12 Plant, Tennessee-Eastman Corp., Oak Ridge. No significantly increased mortality from these cancers was evident.


Asunto(s)
Tórax/metabolismo , Uranio/metabolismo , Semivida , Humanos , Pulmón/metabolismo , Masculino , Matemática , Minería , Enfermedades Profesionales/metabolismo , Dosis de Radiación , Protección Radiológica , Factores de Tiempo , Uranio/análisis
17.
Health Phys ; 44 Suppl 1: 81-9, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-6862934

RESUMEN

Estimates are presented of the alpha particle doses accumulated by individual organs and soft tissues of Reference Man in a 50-yr period following single intakes of 226Ra and 228Ra. With no decay of 226 Ra daughter products in soft tissue, the median dose is 67 mrad per muCi 226Ra intake. With no translocation of 228Ra daughter products, the dose per muCi 228Ra intake is 5.77 times the corresponding value for 226Ra. Biological variability introduces substantial uncertainty when applying these estimates to a particular individual.


Asunto(s)
Partículas alfa , Radio (Elemento)/análisis , Humanos , Matemática , Dosis de Radiación , Radiometría , Radio (Elemento)/metabolismo , Estándares de Referencia , Factores de Tiempo , Distribución Tisular
18.
Health Phys ; 54(5): 517-27, 1988 May.
Artículo en Inglés | MEDLINE | ID: mdl-3360604

RESUMEN

From the results of serial measurements of body 226Ra activity in 13 former luminous dial workers 30-60 y after relatively brief periods of intake of luminous compounds in adolescence or young adulthood, we determined the postmenopausal rate of elimination of Ra in percent of contemporary body Ra content per year. This rate was negatively correlated with the "reduced x-ray score," a measure of radiation osteonecrosis observed radiographically in the 13 subjects (r = -0.85, P less than 0.001). The clearance rates of subjects retaining low Ra activity were greater than predicted by retention models. We conclude that for those members of the Ra-exposed population under study for health effects at our institution who sustained the lesser degrees of macroscopic skeletal damage, present estimates of skeletal absorbed dose are systematically low, by at most a factor of 2.


Asunto(s)
Huesos/efectos de la radiación , Menopausia , Radio (Elemento)/metabolismo , Adulto , Carga Corporal (Radioterapia) , Huesos/metabolismo , Exposición a Riesgos Ambientales , Femenino , Humanos , Persona de Mediana Edad
19.
Health Phys ; 44 Suppl 1: 323-41, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-6305878

RESUMEN

Various techniques are employed to determine the amounts, retention, and distribution of radioactivity in human subjects in vivo. The principal method is gamma-ray spectrometry with large NaI(Tl) scintillation crystals ("whole-body counting"). The geometries used include an arc of 1.5-m radius in which all parts of the body are roughly equidistant from the detector, a reclining chair and a flat bed with detectors placed above and below the subject. When a sufficient amount of radioactivity is present in a subject, scanning techniques assist in determining its distribution in the body. Specialized instruments such as a xenon-filled proportional counter and a dual-crystal (phoswich) detector are used to measure low-energy photon emitters, primarily plutonium and americium. americium. There are three primary methods of calibrating the detectors. The first is analytical, in which a rigorous mathematical treatment is employed; the second involves the administration of tracer amounts of radioactivity to human volunteers; the third consists of determining detector response to known amounts of radioactivity in a phantom. All three methods can be intercompared, and further evaluated by comparing the results of measurements in vivo with those of postmortem analyses. For both radium and thorium cases measured in vivo, the interpretation of the results is complicated by the fact that neither radium nor thorium emit gamma rays of any consequence. Instead, the observed gamma rays result from the decay of 214Bi (RaC) and 208Tl (ThC"), respectively. Since each of these nuclides is preceded in the decay chain by an isotope of the noble gas radon, some of which is exhaled, its activity is not equal to that of the parent radium or thorium. Therefore, breath samples are collected to determine the exhalation rate of the precursor isotope, 222Rn (radon) or 220Rn (thoron). The total body content is then the sum of the gamma activity and the exhaled radioactivity, referred to as the retained and emanating fractions, respectively.


Asunto(s)
Elementos de Series Actinoides/análisis , Radio (Elemento)/análisis , Americio/análisis , Huesos/análisis , Pruebas Respiratorias , Calibración , Rayos gamma , Humanos , Illinois , Matemática , Plutonio/análisis , Radiometría/instrumentación , Radiometría/métodos , Radón/análisis , Torio/análisis , Recuento Corporal Total/métodos
20.
Radiat Meas ; 26(6): 889-92, 1996 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11540521

RESUMEN

The ultra heavy cosmic ray experiment (UHCRE) on the Long Duration Exposure Facility (LDEF) collected approximately 3000 cosmic ray nuclei with Z > 65 in the energy region E > 1.5 GeV/n. Almost 40% of the sample has been analysed to date. Details of the overall charge abundance pattern is outlined with estimates of the actinide abundance.


Asunto(s)
Radiación Cósmica , Monitoreo de Radiación/instrumentación , Vuelo Espacial/instrumentación , Elementos de Series Actinoides , Radiometría , Nave Espacial
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