Application of dosimetry measurements to analyze the neutron activation of a stainless steel sample in a training nuclear reactor

All materials present in the core of a nuclear reactor are activated by neutron irradiation. The activity so generated produces a dose around the material. This dose is a potential risk for workers in the surrounding area when materials are withdrawn from the reactor. Therefore, it is necessary to assess the activity generated and the dose produced. In previous works, neutron activation of control rods and doses around the storage pool where they are placed have been calculated for a Boiling Water Reactor using the MCNP5 code based on the Monte Carlo method. Most of the activation is produced indeed in stainless steel components of the nuclear reactor core not only control rods. In this work, a stainless steel sample is irradiated in the Training Reactor AKR-2 of the Technical University Dresden. Dose measurements around the sample have been performed for different times after the irradiation. Experimental dosimetric values are compared with results of Monte Carlo simulation of the irradiation. Comparison shows a good agreement. Hence, the activation Monte Carlo model can be considered as validated.Ródenas Diago, J.; Gallardo Bermell, S.; Weirich, F.; Hansen, W. (2014). Application of dosimetry measurements to analyze the neutron activation of a stainless steel sample in a training nuclear reactor. Radiation Physics and Chemistry. 104:368-371. doi:10.1016/j.radphyschem.2014.05.013S36837110

Veno-occlusive disease of the liver in children treated for Wilms tumor

Hepatotoxicity consistent with the clinical diagnosis of veno-occlusive disease (VOD) of the liver has been suspected after conventional anti-cancer chemotherapy in children. To establish the incidence of hepatotoxicity and its relationship with VOD, we analyzed toxicity data obtained on 511 children affected by Wilms tumor and treated according to the SIOP-9 protocol. They all received pre- and postnephrectomy chemotherapy using dactinomycin (AD) and vincristine (VCR) +/- other drugs +/- radiotherapy according to surgical stage and histology. Sixty-four patients suffered at least one episode of hepatotoxicity and 41 satisfied the criteria for a clinical diagnosis of VOD. In this latter group, toxicity occurred during preoperative treatment in 15 patients and was confirmed histopathologically in 9 of the 16 liver biopsies obtained. There was a higher percentage of children aged less than 1 year at diagnosis in the VOD group than in the other patients (24% vs. 11.4%). The degree of liver damage in the younger patients seems important, as suggested by a higher increase in transaminases. VOD developed in 12% of the 68 irradiated children vs. 7% in the non-irradiated group. Statistical analysis showed an increased risk of VOD in younger patients (p < 0.001) and in those receiving radiotherapy (p < 0.001). All patients recovered after 6-180 days using supportive therapy only. (1) 8% of children treated according to the SIOP-9 protocol, developed hepatotoxicity consistent with VOD. Excluding patients who received radiotherapy, the incidence was 6%. These figures are much higher than in earlier reports, though different diagnostic criteria were used. (2) Chemotherapy with AD and VCR seems to be a major cause of VOD. (3) Risk factors are young age and concomitant radiotherapy. (4) VOD does not prejudice positive outcome for these patient

Mortalidade neonatal em unidades de cuidados intensivos no Brasil Central

OBJETIVO: Identificar fatores prognósticos de mortalidade neonatal em unidades de cuidados intensivos. MÉTODOS: Realizou-se estudo de coorte de nascidos vivos do município de Goiânia, no período de novembro de 1999 a outubro de 2000. Procedeu-se à vinculação das bases de dados das declarações de nascidos vivos e de óbitos, das quais as variáveis de exposição foram extraídas. Adicionalmente, foi implementado um sistema ativo de vigilância de mortalidade neonatal. A variável de efeito foi constituída dos recém-nascidos admitidos nas unidades de cuidados intensivos que sobreviveram (n=713) e dos que morreram (n=162). Utilizou-se o modelo de regressão de Cox para identificar fatores associados à mortalidade neonatal e a curva Receiver Operating Characteristic para avaliar a acurácia de variáveis estatisticamente significantes em modelo multivariado. Taxas de mortalidade ajustadas por peso de nascimento e Apgar do quinto minuto foram calculadas para cada unidade de cuidados intensivos. RESULTADOS: Baixo peso ao nascer e Apgar do quinto minuto permaneceram associados ao óbito neonatal, de forma independente. Peso ao nascer igual a 2.500 g apresentou acurácia de 0,71 (IC 95%: 0,65-0,77) na predição de óbito neonatal (sensibilidade =72,2%). Observou-se ampla variação nas taxas de mortalidade entre as unidades de cuidados intensivos (9,5%-48,1%) sendo que duas delas permaneceram com taxas significantemente mais altas após o ajuste da mortalidade pelo peso de nascimento e Apgar. CONCLUSÕES: Os resultados mostraram que o peso de nascimento é uma variável sensível para uso em triagens em programas de vigilância de óbito neonatal e pode identificar as unidades de cuidados intensivos com altas taxas de mortalidade para implementação de ações preventivas e para intervenções no período intra-parto.OBJECTIVE: To identify potential prognostic factors for neonatal mortality among newborns referred to intensive care units. METHODS: A live-birth cohort study was carried out in Goiânia, Central Brazil, from November 1999 to October 2000. Linked birth and infant death certificates were used to ascertain the cohort of live born infants. An additional active surveillance system of neonatal-based mortality was implemented. Exposure variables were collected from birth and death certificates. The outcome was survivors (n=713) and deaths (n=162) in all intensive care units in the study period. Cox's proportional hazards model was applied and a Receiver Operating Characteristic curve was used to compare the performance of statistically significant variables in the multivariable model. Adjusted mortality rates by birth weight and 5-min Apgar score were calculated for each intensive care unit. RESULTS: Low birth weight and 5-min Apgar score remained independently associated to death. Birth weight equal to 2,500g had 0.71 accuracy (95% CI: 0.65-0.77) for predicting neonatal death (sensitivity =72.2%). A wide variation in the mortality rates was found among intensive care units (9.5-48.1%) and two of them remained with significant high mortality rates even after adjusting for birth weight and 5-min Apgar score. CONCLUSIONS: This study corroborates birth weight as a sensitive screening variable in surveillance programs for neonatal death and also to target intensive care units with high mortality rates for implementing preventive actions and interventions during the delivery period

Selectivity of saflufenacil applied alone or mixed to glyphosate in maize.

The use of selective herbicides is important for weed management in agricultural crops. Selectivity studies of new molecules are really important to expand the control options of glyphosate-resistant and -tolerant eudicotyledons in corn. The objective of this work was to evaluate the selectivity of the herbicide saflufenacil applied alone in different doses in post-emergence of corn and in a mixture with glyphosate. The design used was randomized blocks, with four replications, with treatments consisting of five doses of saflufenacil, applied alone and in a mixture with a fixed dose of glyphosate, in addition to the weeded control and only glyphosate. At 7, 14, 21 and 28 days after application (DAT), the phytotoxicity of the herbicides to the crop was evaluated. The physiological variables were measured at 35 DAT. At harvest, yield components were determined, in addition to the mass of 1,000 grains and grain yield. The application of the mixture of glyphosate with saflufenacil increases phytotoxicity symptoms and yield losses. Doses of up to 70 g ha-1, applied alone, caused low phytotoxicity to corn and did not interfere in yield. The use of glyphosate + saflufenacil tank mixtures caused decreases in yield of 43.96 and 40.81% when compared, respectively, with the weeded control and the averages of the applications of the herbicides alone. Saflufenacil has the potential to be used in the management of eudicotyledonous weeds, as long as it is not mixed with glyphosate and the dose limit is respected

Impacts of algal blooms and microcystins in fish on small-scale fishers in Winam Gulf, Lake Victoria: implications for health and livelihood

Lake Victoria, bordered by Kenya, Tanzania, and Uganda, provides one of the largest freshwater fisheries in the world and supports millions in small-scale fishing communities. Historical environmental change, including population growth, nutrient loading, introduced invasive species, and rising temperatures, has resulted in eutrophication and persistent cyanobacterial harmful algae blooms (cyanoHABs) over recent decades, particularly in the shallower gulfs, bays, and inlets. CyanoHABs impact fisheries and food web dynamics and compromise food and water security for nearshore fisher populations. In this study, we examine the socialecological impact of freshwater blooms on fisher health in one of these eutrophic regions, Winam Gulf in Lake Victoria. CyanoHABs persist for months and produce microcystins and hepatotoxins at levels unsafe for human health. We assessed potential risk and contribution of microcystin exposure through fish consumption, in addition to exposure through water source, and conducted 400 fisher and 400 household surveys. Average microcystin concentrations exceeded the World Health Organization (WHO) guideline for drinking water consistently during the long dry season, and cyanobacterial cell counts surpassed WHO standards for recreational risk in 84% of samples. Hazard quotients for fish consumed by young children were 5 to 10 times higher than permissible levels. In addition, fishers chronicled profound ecosystem changes with direct impact on livelihood, fisheries, and water quality with 77.4% reporting a decline in profit or catch, 83.1% reporting adverse impacts of cyanoHABs on fish in the lake, and 98.2% reporting indicators of declining water quality in the lake overall. Through the application of a social-ecological lens to a public health model, we identified spheres of influence that modify how fishers experience HABs related stressors and risks to provide a starting point at which to identify sustainable strategies to improve food and water security and livelihood for the millions in nearshore communities

Conservação e uso dos recursos florestais não madeiráveis da floresta com araucária: Programa Conservabio.

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Adequação de propriedades rurais ao Código Florestal Brasileiro: estudo de caso no Estado do Paraná.

O Código Florestal Brasileiro de 1965 conceitua e regulamenta as Áreas de Preservação Permanente (APP) e Reserva Legal (RL). Para regulamentar a adequação das propriedades agrícolas ao código florestal, o estado do Paraná instituiu o SISLEG - Sistema de Manutenção, Recuperação e Proteção da Reserva Legal e Áreas de Preservação Permanente. Neste estudo foram quantificadas, com auxílio do sistema de posicionamento global (GPS) e programas de Sistemas de Informações Geográficas (SIG), as APPs e RLs de 147 propriedades em oito municípios das regiões centro-oriental e sudeste do Paraná, visando analisá-las frente ao Código Florestal vigente. Observou-se expressiva cobertura florestal formada por fragmentos de Floresta Ombrófila Mista; as superfícies disponíveis para definição de RL apresentam valores superiores àqueles requeridos pela legislação. Há necessidade de recomposição das APPs em 67% das propriedades; 26% das propriedades estão de acordo com as exigências do Código Florestal. A quantificação da cobertura florestal necessária e remanescente, tal como a pequena demanda de área para readequação de APP (5% da área total) permitem inferir que esses quesitos não são entraves para a regularização ambiental da agricultura familiar, nas propriedades analisadas

Seronegative Herpes simplex Associated Esophagogastric Ulcer after Liver Transplantation

Herpes simplex infection is characterized by acute or subacute infection, often followed by a chronic carrier state. Consecutive recurrences may flare up if immunocompromise occurs. Herpes simplex associated esophagitis or duodenal ulcer have been reported in immunocompromised patients due to neoplasm, HIV/AIDS or therapeutically induced immune deficiency. Here we report the case of an HSV-DNA seronegative patient who developed grade III dysphagia 13 days after allogeneic liver transplantation. Endoscopy revealed an esophageal-gastric ulcer, and biopsy histopathology showed a distinct fibroplastic and capillary ulcer pattern highly suspicious for viral infection. Immunohistochemistry staining revealed a distinct nuclear positive anti-HSV reaction. Antiviral therapy with acyclovir and high-dose PPI led to a complete revision of clinical symptoms within 48 h. Repeat control endoscopy after 7 days showed complete healing of the former ulcer site at the gastroesophageal junction. Although the incidence of post-transplantation Herpes simplex induced gastroesophageal disease is low, the viral HSV ulcer may be included into a differential diagnosis if dysphagia occurs after transplantation even if HSV-DNA PCR is negative