Measurement of the intensities of the long-range alpha particles from 212Po.

212Bi partially decays by ß- populating excited levels of 212Po. Some of these excited states of 212Po decay with very low probability by direct alpha-particle emissions instead of a gamma-alpha cascade. This effect was known since the earliest times after the discovery of radioactivity. Emission energies of these long-range alpha particles were measured in the past, but the activity ratios were not accurately determined. Relative intensities for these decays have now been experimentally determined. Results agree with data previously reported. It is the first time that an uncertainty estimate is provided for such experiment.

Conversion factor and other variables in the indoor retrospective radon activity concentration studies.

Estimation of indoor retrospective radon activity concentration can be performed by measuring the 210Po surface activity concentration of the radon progeny on mirrors. The conversion factor between the surface activity concentration of 210Po on mirrors and the retrospective activity concentration of 222Rn in the air was determined. Several places and some variables have been considered. Exposures were performed in places with moderate and high concentrations of 222Rn. The repeatability of results has been investigated. The dependence of concentration on exposure time has been checked. The effect of cleaning the mirror surfaces has been analyzed. The experimental results obtained for the possible 210Pb-210Po equilibrium inside the mirrors have also been studied and compared with the theoretically expected values.

Study of the 243Am decay.

Gamma-ray emission probabilities for 243Am were published in 1996. Three new gamma transitions were then found: 46.84, 98.36 and 102.02keV. In the last evaluation by the Decay Data Evaluation Project, the emission probabilities of 46.84 and 102.02keV transitions were not included. Alpha-gamma coincidence measurements have been now used to check and revise the values for these two transitions and their emission probabilities. The emissions of the 31.13, 43.53, 74.66, 86.71 and 141.89keV transitions were also studied.

Study about the radionuclides implanted on glass surfaces for the estimation of retrospective indoor radon concentrations.

Indoor radon retrospective dosimetry can be performed by measuring the 210Po activity concentration deposited on surfaces. An experimental study about the implantation of 210Po on mirrors exposed to radon has been performed. Two cases were studied: exposure to high and low 222Rn concentrations. Results were compared with those calculated by using the activity evolution equations. Experimental results can be only explained assuming additional deposition of the long-lived 222Rn descendants.

[Demographic and clinical features of diagnosed individuals of enterobiasis in the southern Gran Canaria: sampling assessment]. / Características clínico-demográficas de la población del Sur de Gran Canaria con diagnóstico de enterobiasis: valoración de la toma de muestras.

OBJECTIVE: Enterobius vermicularis, also known as pinworn, is the responsible agent for Human Enterobiasis. It is one of the most prevalent, but underrated, parasitic disease in children population. Diagnosis involves demonstration of either eggs or adult worms by Graham test. The aim of this study is to describe the clinical, demographic and microbiological features of patients with suspected diagnosis of Enterobiasis in southern Gran Canaria. METHODS: Descriptive and prospective study of perianal samples evaluated by Graham test in the Microbiology Department of `Insular de Gran Canaria´ University Hospital between November 2014 and November 2015. Descriptive analysis to evaluate the correlation between clinical and demographic variables and the results of Graham test microbiological observation. RESULTS: 1,128 samples were analyzed. E. vermicularis was found in 11.4% of the samples. Among the positives samples, 88.4% belonged to children under 14 years, and 53.5% were male. Abdominal pain (18.6%), anal itching (11.6%), eosinophilia (8.5%) and intestinal parasitosis suspicion (7.8%) were the reasons of parasitological investigation request in positive samples. Nevertheless, a high proportion of the requests was not founded in a suspicious diagnosis or was unrelated to Enterobiasis. CONCLUSIONS: Enterobiasis is a common disease in primary health care and is of great importance in Gran Canaria. Quality in sample collection as well as diagnosis suspicious information are necessary for a good microbiological analysis.

New trends in breast cancer surgery: a therapeutic approach increasingly efficacy and respectful of the patient.

The surgical management of breast cancer has undergone continuous and profound changes over the last 40 years. The evolution from aggressive and mutilating treatment to conservative approach has been long, but constant, despite the controversies that appeared every time a new procedure came to light. Today, the aesthetic satisfaction of breast cancer patients coupled with the oncological safety is the goal of the modern breast surgeon. Breast-conserving surgery with adjuvant radiotherapy is considered the gold standard approach for patients with early stage breast cancer and the recent introduction of "oncoplastic techniques" has furtherly increased the use of breast-conserving procedures. Mastectomy remains a valid surgical alternative in selected cases and is usually associated with immediate reconstructive procedures. New surgical procedures called "conservative mastectomies" are emerging as techniques that combine oncological safety and cosmesis by entirely removing the breast parenchyma sparing the breast skin and nipple-areola complex. Staging of the axilla has also gradually evolved toward less aggressive approaches with the adoption of sentinel node biopsy and new therapeutic strategies are emerging in patients with a pathological positivity in sentinel lymph node biopsy. The present work will highlight the new surgical treatment options increasingly efficacy and respectful of breast cancer patients.

Measuring radon concentrations and estimating dose in tourist caves.

Caves and mines are considered to be places of especial risk of exposure to (222)Rn. This is particularly important for guides and workers, but also for visitors. In the Extremadura region (Spain), there are two cave systems in which there are workers carrying out their normal everyday tasks. In one, visits have been reduced to maintain the conditions of temperature and humidity. The other comprises several caves frequently visited by school groups. The caves were radiologically characterised in order to estimate the dose received by workers or possible hazards for visitors.

Radon in underground waters as a natural analogue to study the escape of CO2 in geological repositories.

Activity concentrations of dissolved (222)Rn and (226)Ra were measured in several underground aquifers, which are candidates for repositories or for the study of analogue natural escapes of CO2. The concentration of both radionuclides in water was determined using liquid scintillation counting. The values obtained for the (222)Rn concentrations varied from 0 to 150 Bq l(-1), while the levels of (226)Ra were in general very low. This indicates that (222)Rn is coming from the decay of the undissolved (226)Ra existing in the rocks and deep layers of the aquifers, being later transported by diffusion in water.

Effect of date palm coproducts and annatto extract on lipid oxidation and microbial quality in a pork liver pâté.

Dates are an interesting source of bioactive compounds, and coproducts from the date industry are of potential use in the manufacturing of meat products. In the present research, spreadable pork liver pâtés were made using fresh date coproducts (2.5% and 7.5%) as a potential functional ingredient and an ethanolic annatto extract (128 mg/kg) as colorant. The effect of these 2 ingredients on the lipid oxidation and microbial quality of the pâtés was assessed during 21 d of storage. The pâtés containing 7.5% date paste were seen to have the highest content of phenolic compounds during storage. The combination of 2.5% date paste and annatto protected pâtés against lipid oxidation throughout the 21 d of storage, thiobarbituric acid-reactive substances values being 0.47 mg MDA/kg at the end of this period, while other combinations increased oxidation compared to the control pâté. The control and those made with 2.5% date paste alone showed the highest counts of mesophilic aerobic bacteria, while the addition of annatto and/or 7.5% date paste reduced this count. The results suggest that a combination of both ingredients is necessary to reduce oxidation and microbial growth, but whereas the concentration of 2.5% is more appropriate to reduce oxidation, the combination with 7.5% date paste reduces the microbial counts. Both ingredients could have an opportunity of valorization in the meat industry for improving the quality.

Diamond detector for alpha-particle spectrometry.

An artificially grown high purity diamond was used as a detector for alpha-particle spectrometry. Diamond detectors can match the performance of silicon detectors employed in standard continuous air monitoring systems. Its radiation hardness and electronic properties make them ideal to work under extreme condition such as high temperature and ambient lights. A 50 µm thickness single-crystal diamond detector has been compared with a 300 µm passivated implanted planar silicon detector, under ambient conditions.

Experimental studies about the ratio between 210Po deposited on surfaces and retrospective indoor 222Rn concentrations.

Measurements of radon concentration may not be sufficiently representative for the cumulative total exposure suffered by a person throughout his life. Retrospective dosimetry can help estimating from the direct measurement of 210Po (descendant of 222Rn) implanted on surfaces, because this quantity is related (through the conversion factor) with the mean indoor 222Rn concentration existing in a room for long time. This factor depends on multiple variables. Theoretical models can provide some values. Experiments are tedious and very time consuming. The 210Po activity concentration was measured in mirrors, which were previously exposed to 222Rn concentrations under real environmental conditions. This work deals with the preliminary results in two known places (a room and a cave), which have very different characteristics, in order to show experimentally the large differences found in the values of this factor.

Improvements to alpha-particle spectrometry techniques.

Improvements to the conventional methods for alpha-particle spectrometry measurement and analysis have recently been implemented in our laboratory. They include the application of corrections for energy drift in long-duration measurements, the development and application of an efficient deconvolution method for complex alpha spectra using the new computer code ALFITeX, an alpha-gamma coincidence system using a dual-parameter multichannel analyzer, and the digitization of this coincidence system.

Measurements of alpha-gamma coincidences with an optimized dual-parameter multichannel system.

Measurements of alpha-gamma coincidences have usually been carried out using a single channel to detect alpha-particles of a given energy, and a multichannel analyser for the detection of the corresponding coincident gamma-rays. An alpha-gamma coincidence chamber coupled to the electronic chain ending with a dual-parameter multichannel analyser has been developed and optimized. This system simultaneously stores alpha-particle, gamma-ray, and alpha-gamma coincidence spectra, which allows a general analysis to be made of the degree of coincidence between each alpha-particle and each gamma-ray emission. With this technique, a two-dimensional spectrum was obtained and analysed using "contour graphics". An application to the study of the decay scheme of (241)Am is described.

On the use of different scintillation cocktails for determining gross alpha and beta activities in water samples.

Gross alpha and beta indices for water samples are generally measured in environmental radioactivity laboratories. Liquid scintillation spectrometers can be used to determine these indices but different factors could affect the measurements. Several scintillation cocktails and different radionuclides have been used for calibration. Quenching effects must be considered for each cocktail because the results can be different depending of the calibration and cocktail used.

Gross alpha and beta indices in water samples revisited.

Gross α and ß indices for water samples are generally determined simultaneously when a gas-flow proportional counter is used. The thickness of the source and the α-particle energy are factors of great importance due to self-absorption or energy loss effects. Two variables have been studied: the use of different salts to produce standards with several thicknesses and the use of different radionuclides for the calibration process. Samples of known activity were prepared and measured for checking the procedures.

Additional contamination when radon is in excess.

A study of the behavior of the (222)Rn progeny on clothes, skin and hair has been performed in a place with very high radon concentration. In the past, radon concentration was established to be about 32 kBq/m(3) in a very high humidity environment inside a tourist cave in Extremadura (Spain). The results show that (222)Rn daughters are adhered on clothes, skin and hair, adding some radioactive concentration to that due to radon and its progeny existing in the breathable air.

Determination of alpha activity in solid samples by leaching or digestion.

The analysis of solid environmental samples by α-particle spectrometry generally involves processes requiring an initial treatment to destroy the complexes in the matrix, and dissolve the radionuclides of interest. This study compared the activities obtained for several natural radionuclides ((238)U, (234)U, (230)Th, (226)Ra, and (210)Po) in previously well-characterized materials, using two procedures: acid leaching and digestion in a microwave oven. The measured activities were in general very similar for the two procedures, with a strong statistical correlation between the two sets of values.

Sample quality index to preselect suitable carbonate samples for alpha spectrometry U/Th dating.

Accurate dating of samples by alpha spectrometry presupposes that the dated system behaved as closed and that no allochthonous (232)Th was provided to the system. Therefore the selection of appropriate samples is a fundamental task that will determine the reliability and accuracy or not of the results. In this paper, by means of a thorough characterisation, those petrological and chemical variables that allow the preselection of the most suitable samples to be dated have been identified and used to calculate the sample quality index.

Estimating retrospective indoor radon concentrations with a new device.

From the (222)Rn mixed with air, the short-lived daughters (218)Po, (214)Pb, (214)Bi, and (214)Po attach to dust particles and are deposited on surfaces where finally (210)Pb and (210)Po are formed. The alpha particles from (210)Po can be measured on surfaces such as window glass or mirrors. The design and construction are presented of a new device using a silicon detector to measure this (210)Po. Some preliminary results are reported and estimates of retrospective radon concentrations are made from them.