Research on the formulation and revision of radiological parameters in the "Standards for Drinking Water Quality（GB5749-2022）" in China / 中华预防医学杂志

The radioactive safety of drinking water has attracted increasing public concern. The newly issued Standards for Drinking Water Quality (GB5749-2022) in China has revised the radiological parameters. This article provides an overview of the main sources, levels of radionuclides in drinking water, and summarized the individual doses criterion and adverse health effects associated with exposure of the public to radionuclides from drinking-water. It analyzes and discusses the relevant revision content of radiological parameters, including the guidance values for screening gross α and gross β, subtracting the contribution of potassium-40 from gross β activity when the gross β activity concentration exceeds the screening level, and the basis for establishing the limit values of reference indices uranium and radium-226. Specific implementation and evaluation suggestions are also proposed.

Radionuclide concentrations and excess lifetime cancer risk due to gamma radioactivity in tailing enriched soil around Maiganga coal mine, Northeast Nigeria

Background: Human activities such as mining enhance the radioactivity levels above normal background which can lead to an incremental increase in the radiation risk to the population

Materials and Methods: 20 tailing enriched soil samples collected around Maiganga coal mine, Gombe, Northeast Nigeria were assessed for their[226]Ra,[232]Th and [40]K contents using HPGe gamma-ray detector

Results: The mean activity values of 11.9013.0, 17.72+/-3.6 and 70.44+/-20.4 Bq kg[-1] were obtained for [226]Ra, [232]Th and [40]K respectively. These values were below the world average values documented by UNSCEAR. The ratio of [232]Th:[226]Ra obtained was 1.5, which showed that [232]Th activity was higher than the activity of [226]Ra while [40]K recorded the highest activity concentration in the studied samples. Statistical analysis identified strong positive relationships among all radiological parameters and confirmed that [225]Ra,[232]Th and [40]K were the major contributors to radiation dose. Radium equivalent activity [Ra[eg]], absorbed gamma dose rate [D[r]], annual effective dose [AEDE], activity utilization index [AUI], external and internal hazard indices [H[ex]] and H[in], gamma representative index [l[vr]], annual gonadal dose [AGDE] and excess lifetime cancer risk [ELCR] were calculated to quantify the radiation risk to the public from exposure to[226]Ra, [232]Th and [40]K in the studied samples. The mean values of these hazard parameters were within the acceptable limits provided for human safety and environmental protection

Concfusfon: The use of the raffing enrfcnecf soff sampfes of Maiganga coaf mine for any purpose whatsoever does not therefore pose any immediate radiological risk to the coaf workers or the general pubfic

Radioisótopo e modelagem matemática na avaliação da suplementação de fitase em dietas para suínos em crescimento / Radioisotope and mathematical modeling in the assessment of supplementation of Phytase in diets for growing pigs

O objetivo deste trabalho foi avaliar os efeitos da inclusão de níveis crescentes de enzima fitase em dietas para suínos em fase de crescimento, por meio do uso de modelagem matemática. Foram utilizados dados de 20 leitões mestiços, machos castrados, pesando em média, 26,8kg. Os animais ficaram alojados em gaiolas metabólicas individuais para a coleta de fezes e urina, onde permaneceram por um período de 17 dias. Utilizou-se o delineamento experimental de blocos ao acaso, com cinco tratamentos e quatro repetições. A dieta experimental fornecida aos leitões foi à base de milho e farelo de soja, suplementada com cinco níveis crescentes de enzima fitase (0, 250, 500, 750 e 1000UF/kg), correspondendo a 0; 0,01; 0,02; 0,03 e 0,04%, respectivamente. As variáveis avaliadas foram: ingestão, excreção, fluxo e refluxo do P nos compartimentos (trato digestivo, corrente sanguínea, tecidos moles e ossos). A enzima fitase não interferiu no P consumido (P>0,05 (F10), no P excretado na urina (F02), no fluxo e refluxo do P nos ossos (F32 e F23) e nos tecidos moles (F42 e F24), entretanto observou-se redução no P excretado nas fezes (F01) em 8,92%; 26,76%; 22,53% e 28,64% para os níveis 0, 250, 500, 750 e 1000UF/kg, respectivamente, e efeito linear positivo para o P endógeno (F12). Pode-se utilizar dietas à base de milho e farelo de soja com 50% de P por fosfato bicálcico, adicionando-se 250UF/kg de dieta para suínos em crescimento, o que reduz em 27% as excreções de P nas fezes.

The purpose of this study was to evaluate the effects of including increasing levels of phytase enzyme in pig diets for growing pigs, using the mathematical model. Data from 20 crossbred male piglets, castrated and weighing 26.80 kg on average was used. The animals were housed in individual metabolic cages to collect feces and urine in a 17 day period. A randomized block experimental design containing five treatments and four repetitions was used. The experimental diet provided to piglets contained corn and soybean and was supplemented with five increasing levels of phytase enzyme (0, 250, 500, 750 and 1000 UF/kg), corresponding to 0.00 %, 0.01 %, 0.02 %, 0.03 % and 0.04 % respectively. The variables evaluated were: intake, excretion, output flow of P in the digestive tract, bloodstream, bones and soft tissues. The phytase enzyme did not affect the P intake (P>0.05 (F 10), the P excreted in urine (F02) and the output flow of P in the bones (F32 e F23) and soft tissue (F42 e F24) , however, there was a reduction in P excreted in feces (F01) of 8.92 %, 26.76 %, 22.53 % and 28.64 % to the levels 0, 250, 500, 750 e 1000UF/kg, respectively and showed a positive linear effect (P<0.08) for the endogenous P (F12) . Corn and soybean meal based diets can be used with 50% of P by dicalcium phosphate, adding 250UF/kg diet for growing pigs, and may cause a reduction of 27 % of P excretion in feces.

Polymeric micelles and molecular modeling applied to the development of radiopharmaceuticals

Micelles composed of amphiphilic copolymers linked to a radioactive element are used in nuclear medicine predominantly as a diagnostic application. A relevant advantage of polymeric micelles in aqueous solution is their resulting particle size, which can vary from 10 to 100 nm in diameter. In this review, polymeric micelles labeled with radioisotopes including technetium (99mTc) and indium (111In), and their clinical applications for several diagnostic techniques, such as single photon emission computed tomography (SPECT), gamma-scintigraphy, and nuclear magnetic resonance (NMR), were discussed. Also, micelle use primarily for the diagnosis of lymphatic ducts and sentinel lymph nodes received special attention. Notably, the employment of these diagnostic techniques can be considered a significant tool for functionally exploring body systems as well as investigating molecular pathways involved in the disease process. The use of molecular modeling methodologies and computer-aided drug design strategies can also yield valuable information for the rational design and development of novel radiopharmaceuticals.

Micelas poliméricas compostas de copolímeros ligadas a um elemento radioativo são utilizadas em Medicina Nuclear com aplicação predominantemente diagnóstica. A vantagem relevante da utilização de micelas poliméricas em solução aquosa é o tamanho de suas partículas, as quais podem variar de 10 a 100 nm de diâmetro. Neste trabalho de revisão são apresentadas micelas poliméricas marcadas com radioisotopos, como tecnécio-99m (99mTc) e índio-111 (111In), assim como suas aplicações clínicas em técnicas de diagnóstico como Tomografia por emissão de Fóton Único (Single photon Emission Computed Tomography - SPECT), cintilografia, e Ressonância Magnética Nuclear (RMN). Neste contexto, sua aplicação em diagnóstico de sistema linfático e linfonodo sentinela recebe atenção especial. O emprego de técnicas de diagnóstico pode ser considerado uma ferramenta importante para a exploração de sistemas no organismo humano assim como para a investigação de caminhos moleculares envolvidos nos processos de diversas doenças. O uso de metodologias de modelagem molecular e estratégias de desenvolvimento de fármacos assistidas computacionalmente também pode fornecer informações valiosas para o planejamento e o desenvolvimento racional de novos radiofármacos.

Protocolos de estudio de perfusión miocárdica con radioisotopos en evaluación de cardiopatía coronaria / Studies of myocardial perfusion using radioisotopes in the coronary heart disease

Se revisan los principales protocolos actuales de perfusión miocárdica con técnica isotópica, sus indicaciones, requerimientos y nuevas aplicaciones. Se da especial énfasis a la técnica de SPECT gatillado que agrega parámetros de función a las imágenes tomográficas con mayor valor diagnóstico y pronóstico y también a la introducción de positrones mediante fluordeoxiglucosa en la detección de viabilidad miocárdica.

Indication of CO2 and erbium lasers

The exact indications of CO2 and erbium laser are discussed with the objective of attaining better esthetic results and decreasing morbidity. Indications are based on the knowledge of tissue interaction of each laser, and technical details of the procedure based on 6-year experience in laser resurfacing.

Radioactive characterization of the Pinheiros river bottom sediment

Radionuclide contents were determined in the botton sediment of the Pinheiros river, into which the Instituto de Pesquisas Energéticas e Nucleares (IPEN) has been continuously discharging low level radioactive liquid effluents. The results showed that the activity of natural radionuclides and the activity of (137)Cs found in the sediment were within the range of the expected baskground for the region. (60)Co was the only other artificial radionuclide detected, with concentrations ranging from 0.20 to 0.85 Ba per kilogram dry weight, at some points of the river.

Determinaçäo de U-238, U-234, Th-232, Th-230, Th-228, Ra228 e Ra-226 em águas minerais do Planalto de Poços de Caldas / Determination of U238, U234, Th-232, Th-230, Th-228, Ra-228 and Ra-226 in mineral water from the plateau of Poços de Caldas region

A presença de concentraçöes relativamente altas de radionuclídeos em águas subterrâneas vem despertando o interesse de pesquisadores em radioativideade natural e radioproteçäo. Foram determinadas as concentraçöes de U-238, U-234, Th-232, Th-230, Th-228 e Ra-226 em vinte e quatro amostras de água minerais do Planalto de Poços de Caldas. Os valores máximos observados correspondiam a amostras provenientes da cidade de Aguas da Prata, na borda do planalto, que continham até 2,4 Bq/1 de Ra-226

Variación de la eficiencia de medición del cristal de pozo-espectrómetro monocanal / Variation of the efficiency of measuring of the pair cystal of water spectrometer monocanal

Ante la falta de constancia de la eficiencia de medición, en función del tiempo, de un equipo cristal de pozo-espectrómetro monocanal, se estudiaron las localizaciones de los picos fotoeléctricos de diferentes radionucleidos, utilizando como variables el tiempo, la energía de la radiación y la tensión aplicada. Los resultados indican que dichos picos van corriéndose hacia los niveles de canal más altos, al transcurrir el tiempo de funcionamiento del equipo. Estos corrimientos son más importantes cuanto mayor es la tensión aplicada y cuanto mayor es el valor de la energía de la radicación medida