28 research outputs found
Radiactive particle biotic and abiotic processes
In ecosystems affected by the presence of radioactive particles, it is imperative to obtain information regarding transformation processes that affect them in order to properly evaluate not only their behaviour, but also the potential transfer of radionuclides between different compartments. A protocol for the abiotic transformation of radioactive particles has been developed within the framework of EC and IAEA research projects and has been applied on a range of particles from various sites. Methods for the characterisation of single radioactive particles pre- and post-leaching, using sub-micron resolution imaging techniques have been developed that enable the quantitative analysis of transformation processes
Hydrochemistry and Uranium Concentration in Brackish Groundwater from an Arid Zone, Chihuahua, Mexico
In arid zones, the principal water supply is from groundwater, which can present high concentration of salts, heavy metals, and radioactive elements. The aim of the study was to determine isotopic uranium concentration in groundwater samples with high concentration of salts and its association with other chemical species. Samples were taken from wells with high salt content. The 238,234U radioisotope concentrations were determined by liquid scintillation and alpha-particle spectrometry. In addition, the physical-chemical parameters were recorded in situ; whereas the dissolved ions and elemental composition were measured by UV-Vis and X-ray fluorescence spectrophotometry, respectively. To obtain isotopic uranium concentrations, three radiochemistry procedures were carried out. An ANOVA test was performed to compare the results from procedures, as well as an analysis of Pearson correlation was used between parameters to obtain their associations. Statistically, the U isotopic concentrations did not show differences (p-value 0.82) between procedures. 238U and 234U showed mean concentrations of 6.7 mBq mL-1 and 16.6 mBq mL-1, respectively, with an Activity Ratioby up 7.2. The groundwater under study showed high concentration of TDS, calcium, sulphate, chloride, nitrate, and nitrite. Isotopic U concentrations tend to increase with NO3>Zn>Cl>Br>SO4>Cu>T>SDT>P; meanwhile their contents decrease with T>Cl->NO2>Fe. These findings help us to understand the uranium behavior in groundwater with high salt contents as well as the influence of agricultural supplies on chemical species presents in groundwater
Speed Bump Detection Using Accelerometric Features: A Genetic Algorithm Approach
AmongthecurrentchallengesoftheSmartCity,trafficmanagementandmaintenanceareof utmostimportance. Roadsurfacemonitoringiscurrentlyperformedbyhumans,buttheroadsurface condition is one of the main indicators of road quality, and it may drastically affect fuel consumption and the safety of both drivers and pedestrians. Abnormalities in the road, such as manholes and potholes, can cause accidents when not identified by the drivers. Furthermore, human-induced abnormalities, such as speed bumps, could also cause accidents. In addition, while said obstacles ought to be signalized according to specific road regulation, they are not always correctly labeled. Therefore, we developed a novel method for the detection of road abnormalities (i.e., speed bumps). This method makes use of a gyro, an accelerometer, and a GPS sensor mounted in a car. After having the vehicle cruise through several streets, data is retrieved from the sensors. Then, using a cross-validation strategy, a genetic algorithm is used to find a logistic model that accurately detects road abnormalities. The proposed model had an accuracy of 0.9714 in a blind evaluation, with a false positive rate smaller than 0.018, and an area under the receiver operating characteristic curve of 0.9784. This methodology has the potential to detect speed bumps in quasi real-time conditions, and can be used to construct a real-time surface monitoring system.AmongthecurrentchallengesoftheSmartCity,trafficmanagementandmaintenanceareof utmostimportance. Roadsurfacemonitoringiscurrentlyperformedbyhumans,buttheroadsurface condition is one of the main indicators of road quality, and it may drastically affect fuel consumption and the safety of both drivers and pedestrians. Abnormalities in the road, such as manholes and potholes, can cause accidents when not identified by the drivers. Furthermore, human-induced abnormalities, such as speed bumps, could also cause accidents. In addition, while said obstacles ought to be signalized according to specific road regulation, they are not always correctly labeled. Therefore, we developed a novel method for the detection of road abnormalities (i.e., speed bumps). This method makes use of a gyro, an accelerometer, and a GPS sensor mounted in a car. After having the vehicle cruise through several streets, data is retrieved from the sensors. Then, using a cross-validation strategy, a genetic algorithm is used to find a logistic model that accurately detects road abnormalities. The proposed model had an accuracy of 0.9714 in a blind evaluation, with a false positive rate smaller than 0.018, and an area under the receiver operating characteristic curve of 0.9784. This methodology has the potential to detect speed bumps in quasi real-time conditions, and can be used to construct a real-time surface monitoring system
Natural radionuclides (NORM) in a Moroccan river affected by former conventional metal mining activities
The main aim of this work was to determine the levels of multiple natural radionuclides in an aquatic system (Moulouya river, Morocco) impacted by multiple abandoned Zinc and Lead mines. 238U, 234U, 232Th, 230Th and 210Po were determined by alpha-particlespectrometry in water and sediment samples collected along the river and in samples from three pit lakes of abandoned mines, located in the Upper Moulouya catchment area. The results enabled the analysis of the different levels of impact of former mining activities, depending on the natural radionuclides. While the activity concentrationof U-isotopes in Moulouya river water was slightly elevated in the vicinity of abandoned mine wastes, other natural radionuclides (Th-isotopes and 210Po) levels were typical of a natural environment. This fact is clearly reflected in the magnitude and range observed in the distribution coefficients for the different radionuclides analyzed.Spanish Agency of International Cooperation and Development (AECID) of the Government of Spai
Sol-gel deposition of hydroxyapatite coatings on porous titanium for biomedical applications
The stress shielding and the poor osseointegration in titanium implants are still
problems to be resolved. In this context, this work proposes a balanced solution.
Titanium samples were fabricated, with a porosity of 100-200 µm of pore size
employing space-holder technique (50 vol. % NH4HCO3, 800 MPa at 1250 ºC during 2h
under high vacuum conditions), obtaining a good equilibrium between stiffness and
mechanical resistance. The porous titanium substrates were coated with hydroxyapatite,
obtained by sol-gel technique: immersion, dried at 80ºC and heat treatment at 450ºC
during 5h under vacuum conditions. Phases, surface morphology and interfacial
microstructure of the transverse section were analyzed by Micro-Computed
Tomography, SEM and confocal laser, as well as the infiltration capability of the
coating into the metallic substrate pores. The FTIR and XRD showed the crystallinity of
the phases and the chemical composition homogeneity of the coating. The size and
interconnected pores obtained allow the infiltration of hydroxyapatite (HA), possible
bone ingrowth and osseointegration. The scratch resistance of the coating corroborated
a good adherence to the porous metallic substrate. The coated titanium samples have a
biomechanical and biofunctional equilibrium, as well as a potential use in biomedical
applications (partial substitution of bone tissue).Junta de Andalucía-FEDER (Spain) Project Ref. P12-TEP-1401Spanish Ministry of Economy and Competitiveness Grant No. MAT2015-71284-
Radionucléidos naturales en un perfil de columna de agua en el lago de la corta minera de San Telmo (so de España)
Contralateral asymmetry for breast cancer detection : A CADx approach
Early detection is fundamental for the effective treatment of breast cancer and the screening mammography is the most common tool used by the medical community to detect early breast cancer development.
Screening mammograms include images of both breasts using two standard views, and the contralateral asymmetry per view is a key feature in detecting breast cancer. we propose a methodology to incorporate said asymmetry information into a computer-aided diagnosis system
that can accurately discern between healthy subjects and subjects at risk of having breast cancer.
Furthermore, we generate features that measure not only a view-wise asymmetry, but a subject-wise one.
Briefly, the methodology co-registers the left and right mammograms, extracts image characteristics,
fuses them into subjectwise features, and classifies subjects.
In this study, 152 subjects from two independent databases, one with analog- and one with digital mammograms, were used to validate the methodology.
Areas under the receiver operating characteristic curve of 0.738 and 0.767, and diagnostic odds
ratios of 23.10 and 9.00 were achieved, respectively. In addition, the proposed method has the potential to rank subjects by their probability of having breas
Compromising between European and US allergen immunotherapy schools: Discussions from GUIMIT, the Mexican immunotherapy guidelines
Background: Allergen immunotherapy (AIT) has a longstanding history and still remains the only disease-changing treatment for allergic rhinitis and asthma. Over the years 2 different schools have developed their strategies: the United States (US) and the European. Allergen extracts available in these regions are adapted to local practice. In other parts of the world, extracts from both regions
and local ones are commercialized, as in Mexico. Here, local experts developed a national AIT guideline (GUIMIT 2019) searching for compromises between both schools.
Methods: Using ADAPTE methodology for transculturizing guidelines and AGREE-II for evaluating guideline quality, GUIMIT selected 3 high-quality Main Reference Guidelines (MRGs): the European Academy of Allergy, Asthma and Immunology (EAACI) guideines, the S2k guideline of
various German-speaking medical societies (2014), and the US Practice Parameters on Allergen Immunotherapy 2011. We formulated clinical questions and based responses on the fused evidence available in the MRGs, combined with local possibilities, patient's preference, and costs. We
came across several issues on which the MRGs disagreed. These are presented here along with arguments of GUIMIT members to resolve them. GUIMIT (for a complete English version, see Supplementary data) concluded the following:
Results: Related to the diagnosis of IgE-mediated respiratory allergy, apart from skin prick testing
complementary tests (challenges, in vitro testing and molecular such as species-specific allergens) might be useful in selected cases to inform AIT composition. AIT is indicated in allergic rhinitis and suggested in allergic asthma (once controlled) and IgE-mediated atopic dermatitis. Concerning the correct subcutaneous AIT dose for compounding vials according to the US school: dosing tables and formula are given; up to 4 non-related allergens can be mixed, refraining from mixing high with low protease extracts. When using European extracts: the manufacturer's indications
should be followed; in multi-allergic patients 2 simultaneous injections can be given (100% consensus); mixing is discouraged. In Mexico only allergoid tablets are available; based on doses used in all sublingual immunotherapy (SLIT) publications referenced in MRGs, GUIMIT suggests a probable effective dose related to subcutaneous immunotherapy (SCIT) might be: 50–200% of the monthly SCIT dose given daily, maximum mixing 4 allergens. Also, a table with practical suggestions on non-evidence-existing issues, developed with a simplified Delphi method, is added.
Finally, dissemination and implementation of guidelines is briefly discussed, explaining how we used online tools for this in Mexico.
Conclusions: Countries where European and American AIT extracts are available should adjust AIT according to which school is followed
Mis casos clínicos de especialidades odontológicas
Libro que muestra la atención de casos clínicos particulares referente a las diferentes especialidades odontológicasLibro que muestra la atención de casos clínicos particulares referente a las diferentes especialidades odontológicasUniversidad Autónoma de Campeche
Universidad Autónoma del Estado de Hidalgo
Universidad Autónoma del Estado de Méxic