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1.
J Environ Qual ; 47(5): 1139-1145, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30272803

RESUMO

Reclaimed water obtained from urban wastewater is currently being used as irrigation water in water-scarce regions in Spain. However, wastewater can contain enteric viruses that water reclamation treatment cannot remove or inactivate completely. In the present study, greenhouse-grown baby lettuce ( L.) was irrigated with secondary treatment effluent from a wastewater treatment plant untreated and treated using chlorine dioxide (ClO). The effect of ClO treatment on the physicochemical characteristics and the presence of enteric viruses in irrigation water and lettuce was assessed. The presence of human noroviruses genogroups I and II (NoV GI and NoV GII), and human astroviruses (HAstV), was analyzed by real-time polymerase chain reaction (RT-qPCR). Additionally, to check for the loss of infectivity induced by the disinfection treatment, positive samples were re-analyzed after pretreatment with the intercalating dye PMAxx before RNA extraction and RT-qPCR. There were no significant differences in the proportion of positive samples and the concentration of enteric viruses between treated and untreated reclaimed water without PMAxx pretreatment ( > 0.05). A significantly lower concentration of NoV GI was detected in ClO-treated water when samples were pretreated with PMAxx ( < 0.05), indicating that inactivation was due to the disinfection treatment. Laboratory-scale validation tests indicated the suitability of PMAxx-RT-qPCR for discrimination between potentially infectious and ClO-damaged viruses. Although the applied ClO treatment was not able to significantly reduce the enteric virus load of the secondary effluent from the wastewater treatment plant, none of the lettuce samples analyzed ( = 36) was positive for the presence of NoV or HAstV.


Assuntos
Irrigação Agrícola/métodos , Compostos Clorados/toxicidade , Desinfetantes/toxicidade , Desinfecção/métodos , Óxidos/toxicidade , Águas Residuárias/virologia , Norovirus/efeitos dos fármacos , Eliminação de Resíduos Líquidos/métodos
2.
Br Poult Sci ; 59(4): 408-415, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29667846

RESUMO

1. The influence of gender on chemical composition, physicochemical parameters, fatty acid profile, amino acid and mineral composition of turkey breast and thigh meat was studied in order to assess nutrient requirements. 2. Chemical composition showed that only intramuscular fat in breast meat was significantly affected by gender (p < 0.05). The results showed a higher percentage of intramuscular fat in male samples, almost double the amount found in females (0.73% vs. 0.38%). 3.For meat colour parameters, only a* showed different results between sexes, with male samples (breast: p < 0.01; thigh: p < 0.001) having the highest values. 4. Fatty acid profiles showed that medium chain unsaturated fatty acids were the most abundant. The significant differences (p < 0.05) found in both breast and thigh muscle could be linked to a difference in metabolism between males and females. 5.There were higher levels of C16:1n-7 in females (breast: p < 0.001; thigh: p < 0.01) compared with male muscle sample (5.05 vs. 2.67 g/100 g in breast and 4.95 vs. 3.27 g/100 g in thigh). Nutritional indices (n-6/n-3 and thrombogenic index) were more favourable in female samples demonstrating that female turkeys had better fatty acid profile than the others. 6. Turkey meat is an important source of dietary amino acids, and female samples had the highest contents both of essential and non-essential amino acids. Furthermore, gender had a numeric effect (p > 0.05) on amino acid composition. 7. Mineral composition showed that Na, Zn and Fe were the minerals most affected by turkey gender.


Assuntos
Aminoácidos/análise , Ácidos Graxos/análise , Carne/análise , Minerais/análise , Músculo Esquelético/fisiologia , Perus/fisiologia , Animais , Cor , Feminino , Masculino , Músculos Peitorais/fisiologia , Fatores Sexuais , Espanha
3.
J Appl Microbiol ; 121(4): 1180-8, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27377539

RESUMO

AIMS: To assess the prevalence of enteric viruses in different irrigation water sources and in the irrigated produce, and the possible links with microbiological and physicochemical water characteristics. METHODS AND RESULTS: The prevalence and levels of Escherichia coli, Norovirus (NoV) genogroup I (GI) and II (GII), as well as Hepatitis A virus were assessed in three types of water: surface water (surface-W), reclaimed water subjected to secondary treatment (secondary-W) and reclaimed water subjected to tertiary treatment (tertiary-W), as well as in zucchini irrigated with these irrigation water sources. Chemical oxygen demand (COD), turbidity, total suspended solids, alkalinity and maximum filterable volume (MFV) were also measured in the water. Higher prevalence of NoV in secondary-W (GI 100%, GII 55·6%) and tertiary-W (GI 91·7%, GII 66·7%) compared with surface-W (GI 58·4%, GII 22·2%) was observed. Nov GI showed positive correlation with E. coli (Spearman's correlation coefficient = 0·68, P < 0·01), and with some physicochemical parameters such as COD (0·52, P < 0·01), turbidity (0·52, P < 0·01) and MFV (0·54, P < 0·01). Escherichia coli and enteric viruses were not detected in zucchini. CONCLUSION: There is a potential risk of contamination of crops with NoV when reclaimed water is used for irrigation. SIGNIFICANCE AND IMPACT OF THE STUDY: Increase the knowledge on the prevalence of enteric viruses in different irrigation water sources, and its consequences for fresh produce safety.


Assuntos
Enterovirus/isolamento & purificação , Microbiologia da Água , Irrigação Agrícola , Análise da Demanda Biológica de Oxigênio , Enterovirus/classificação , Enterovirus/genética , Escherichia coli/classificação , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Humanos , Verduras/crescimento & desenvolvimento , Água/análise , Poluição da Água
4.
Environ Res ; 146: 108-15, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26745734

RESUMO

The Deepwater Horizon (DWH) oil spill in the Gulf of Mexico was the largest maritime oil spill in history resulting in the accumulation of genotoxic substances in the air, soil, and water. This has potential far-reaching health impacts on cleanup field workers and on the populations living in the contaminated coastal areas. We have employed portable airborne particulate matter samplers (SKC Biosampler Impinger) and a genetically engineered bacterial reporter system (umu-ChromoTest from EBPI) to determine levels of genotoxicity of air samples collected from highly contaminated areas of coastal Louisiana including Grand Isle, Port Fourchon, and Elmer's Island in the spring, summer and fall of 2011, 2012, 2013 and 2014. Air samples collected from a non-contaminated area, Sea Rim State Park, Texas, served as a control for background airborne genotoxic particles. In comparison to controls, air samples from the contaminated areas demonstrated highly significant increases in genotoxicity with the highest values registered during the month of July in 2011, 2013, and 2014, in all three locations. This seasonal trend was disrupted in 2012, when the highest genotoxicity values were detected in October, which correlated with hurricane Isaac landfall in late August of 2012, about five weeks before a routine collection of fall air samples. Our data demonstrate: (i) high levels of air genotoxicity in the monitored areas over last four years post DWH oil spill; (ii) airborne particulate genotoxicity peaks in summers and correlates with high temperatures and high humidity; and (iii) this seasonal trend was disrupted by the hurricane Isaac landfall, which further supports the concept of a continuous negative impact of the oil spill in this region.


Assuntos
Poluentes Atmosféricos/análise , Exposição Ambiental , Mutagênicos/análise , Material Particulado/análise , Poluição por Petróleo/efeitos adversos , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Golfo do México , Louisiana , Estações do Ano
5.
Food Microbiol ; 58: 29-35, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27217356

RESUMO

The use of fecal indicators such as Escherichia coli has been proposed as a potential tool to characterize microbial contamination of irrigation water. Recently, not only the type of microbial indicator but also the methodologies used for enumeration have been called into question. The goal of this study was to assess the microbial quality of different water sources for irrigation of zucchini plants by using E. coli as an indicator of fecal contamination and the occurrence of foodborne pathogens. Three water sources were evaluated including reclaimed secondary treated water (RW-2), reclaimed tertiary UV-C treated water (RW-3) and surface water (SW). The suitability of two E. coli quantification techniques (plate count and qPCR) was examined for irrigation water and fresh produce. E. coli levels using qPCR assay were significantly higher than that obtained by plate count in all samples of irrigation water and fresh produce. The microbial quality of water samples from RW-2 was well predicted by qPCR, as the presence of foodborne pathogens were positively correlated with high E. coli levels. However, differences in the water characteristics influenced the suitability of qPCR as a tool to predict potential contamination in irrigation water. No significant differences were obtained between the number of cells of E. coli from RW-2 and RW-3, probably due to the fact that qPCR assay cannot distinguish between viable and dead cells. These results indicated that the selection of the most suitable technique for enumeration of indicator microorganisms able to predict potential presence of fecal contamination might be influenced by the water characteristics.


Assuntos
Escherichia coli/isolamento & purificação , Contaminação de Alimentos/prevenção & controle , Doenças Transmitidas por Alimentos/prevenção & controle , Salmonella/isolamento & purificação , Microbiologia da Água , Irrigação Agrícola , Contagem de Colônia Microbiana , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Laticínios , Escherichia coli/genética , Fezes/microbiologia , Salmonella/genética , Análise de Sequência de DNA , Verduras/microbiologia
6.
Med Oral Patol Oral Cir Bucal ; 19(2): e163-9, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24121921

RESUMO

Dental patients with special needs are people with different systemic diseases, multiple disorders or severe physical and/or mental disabilities. A Medline search was made, yielding a total of 29 articles that served as the basis for this study, which offers a brief description of the dental intervention protocols in medically compromised patients. Dental treatment in patients with special needs, whether presenting medical problems or disabilities, is sometimes complex. For this reason the hospital should be regarded as the ideal setting for the care of these individuals. Before starting any dental intervention, a correct patient evaluation is needed, based on a correct anamnesis, medical records and interconsultation reports, and with due assessment of the medical risks involved. The hospital setting offers the advantage of access to electronic medical records and to data referred to any complementary tests that may have been made, and we moreover have the possibility of performing treatments under general anesthesia. In this context, ambulatory major surgery is the best approach when considering general anesthesia in patients of this kind.


Assuntos
Unidade Hospitalar de Odontologia , Doenças Cardiovasculares/complicações , Doenças do Sistema Endócrino/complicações , Humanos , Nefropatias/complicações , Doenças Respiratórias/complicações , Medição de Risco , Fatores de Risco
7.
J Chem Phys ; 134(13): 134102, 2011 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-21476738

RESUMO

Different computational methods are employed to calculate excitation energies of the carbon atom. Explicitly correlated wave functions have been obtained in a Variational Monte Carlo calculation. Fixed node Diffusion Monte Carlo calculations for the lowest energy excited states of a given symmetry are reported. A systematic and quantitative analysis of the performance of the different schemes in the calculation of the excitation energy of up to 27 excited states of the carbon atom is carried out. The quality of the different methods have been studied in terms of the deviation with respect to the experimental excitation energies. A good agreement with the experimental values has been reached.

8.
Actas Esp Psiquiatr ; 39(1): 70-4, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21274824

RESUMO

The position attributed in recent years to overvalued ideas between delusion and obsession and that are derived from the reduction of the construct per se to one of its characteristics, that is, insight, has undergone a critical review. Using a case with dysmorphophobic ideas, the difficulties to define it and differentiate it from delusion are proposed and different psychopathological approaches are outlined that make it possible to reconstruct the case differently.


Assuntos
Delírio/psicologia , Comportamento Obsessivo/psicologia , Humanos , Masculino , Pessoa de Meia-Idade
9.
ESMO Open ; 6(4): 100215, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34325108

RESUMO

BACKGROUND: Young oncologists are at particular risk of professional burnout, and this could have a significant impact on their health and care of their patients. The coronavirus disease 2019 (COVID-19) pandemic has forced rapid changes in professionals' jobs and training, with the consequent physical and psychological effects. We aimed to characterize burnout levels and determinants in young oncologists, and the effects of the pandemic on their training and health. METHODS: Two online surveys were conducted among oncology residents and young oncology specialists in Spain. The first addressed professional burnout and its determinants before the COVID-19 pandemic, while the second analyzed the impact of the pandemic on health care organization, training, and physical and psychological health in the same population. RESULTS: In total, 243 respondents completed the first survey, and 263 the second; 25.1% reported significant levels of professional burnout. Burnout was more common among medical oncology residents (28.2%), mainly in their second year of training. It was significantly associated with a poor work-life balance, inadequate vacation time, and the burnout score. Nearly three-quarters of respondents (72%) were reassigned to COVID-19 care and 84.3% of residents missed part of their training rotations. Overall, 17.2% of this population reported that they had contracted COVID-19, 37.3% had scores indicating anxiety, and 30.4% moderate to severe depression. Almost a quarter of young oncologists (23.3%) had doubts about their medical vocation. CONCLUSIONS: Burnout affects a considerable number of young oncologists. The COVID-19 pandemic has had a profound impact on causes of burnout, making it even more necessary to periodically monitor it to define appropriate detection and prevention strategies.


Assuntos
Esgotamento Profissional , COVID-19 , Oncologistas , Esgotamento Profissional/epidemiologia , Esgotamento Psicológico/epidemiologia , Esgotamento Psicológico/prevenção & controle , Humanos , Oncologia , Pandemias , SARS-CoV-2
10.
J Phys Chem A ; 114(4): 1953-6, 2010 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-20055398

RESUMO

The ground state and the LS terms coming from the ground-state configuration, [Ar]-3d(6)4s(2), of the iron atom are studied by carrying out an all electron Variational Monte Carlo calculation. Explicitly correlated trial functions including near degeneracy effects are used. The effect of electronic correlations and the importance of near degeneracy effects are systematically analyzed for the states here considered and compared with the experimental values. Correlations are important to reproduce, even qualitatively, the low-lying spectrum of this atom. A significant quantitative improvement when comparing with the experimental values is achieved when near degeneracy is considered along with dynamic correlations in the variational trial wave function. Finally, the effect of relativity on the results here reported is discussed.

11.
J Chem Phys ; 133(6): 064102, 2010 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-20707556

RESUMO

Nonrelativistic frozen nucleus all-electron Quantum Monte Carlo ground state energies of positive and negative ions Li(+) to Ar(+) and Li(-) to Cl(-), respectively, are reported. Explicitly correlated wave functions with a single configuration model function times a Jastrow factor are employed for all of the systems studied. The accuracy obtained for the ions in the third period is similar to that reached for the ions in the second one. For those ions with a stronger multiconfiguration nature a restricted multiconfiguration expansion has been employed. The ground state energy here obtained for the charged species shows a similar quality to that reached for neutral atoms. Starting from those results, ionization potentials and electron affinities are calculated.

12.
J Chem Phys ; 131(4): 044115, 2009 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-19655845

RESUMO

All-electron quantum Monte Carlo energies are reported for the ground state of the atoms Li to Ar. The present work is mainly focused on the atoms Na to Ar as well as in those that have a stronger multiconfiguration nature, i.e., Be, B, and C and Mg, Al, and Si. Explicitly correlated wave functions with a single configuration model function times a Jastrow factor are employed for all of the atoms studied. The accuracy obtained for the atoms Na to Ar is similar to that reached for the atoms Li to Ne. In addition, a restricted multiconfiguration expansion has been employed for the atoms Be, B, and C and Mg, Al, and Si obtaining accurate results. Near degeneracy and the effect of other configurations are systematically analyzed for these systems, at both variational and diffusion Monte Carlo levels.

13.
An Pediatr (Barc) ; 70(3): 265-70, 2009 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-19409243

RESUMO

INTRODUCTION: The importance of the influence of diet in the first few years of life on child growth and development and its relationship with the prevention of chronic diseases in childhood and adulthood has recently been stressed. The aim of the present study was to determine the presence or absence of inappropriate feeding practices, defined as non-compliance with dietary recommendations, in children aged less than 2 years old through a survey. SUBJECTS AND METHODS: The parents of 462 children were administered a 14-item questionnaire on compliance with dietary recommendations to define nutritional risk. Depending on the parents' country of birth, children were classified as autochthonous, gypsy, or non-autochthonous. RESULTS: In absolute results, high percentages of non-compliance with a substantial number of recommendations were found in all children and in each of the three groups, with the consequent danger of nutritional risk. CONCLUSIONS: In children in our environment, there are numerous inadequate feeding practices that constitute nutritional risk factors and require preventive and educational interventions to improve the future health of these children when they reach adulthood. In children from ethnic groups, no particularly severe inadequate feeding practices related to origin were found. The gypsy ethnic group requires additional nutritional health education interventions. Health workers should improve the information provided on nutritional recommendations and feeding practices to avoid misunderstanding, as in the case of gluten.


Assuntos
Comportamento Alimentar , Roma (Grupo Étnico) , Migrantes , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Espanha , Inquéritos e Questionários , População Urbana
14.
Meat Sci ; 149: 63-69, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30476859

RESUMO

This study was conducted to compare the essential and toxic element content of seven veal cuts: shoulder clod (SC), inside round (IR), eye of round (ER), bottom round (BR), heel of round (HR), knuckle (KK) and tenderloin (TL). Eighty-four meat samples were determined by ICP-MS. Overall, essential trace elements (Co, Cu, Fe, Mn and Zn), except Se, varied significantly between the different meat cuts. By contrast, there were no significant variations for the minor trace elements (Cr, Mo and Ni) or the toxic elements (As, Cd and Pb). Chemometric analysis of the data identified four clusters: (1) the main trace elements, except (2) Se, which was closely related to (3) the toxic elements, and finally (4) the minor trace elements. TL and ER cuts constituted two separated groups; most of the SC and KK samples were associated, and IR and BR samples overlapped. TL and SC contained the highest amounts of trace elements, whereas ER and KK the lowest.


Assuntos
Carne Vermelha/análise , Oligoelementos/análise , Animais , Bovinos , Análise por Conglomerados , Feminino , Espectrometria de Massas/métodos , Análise de Componente Principal
15.
EFSA J ; 17(Suppl 2): e170913, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32626471

RESUMO

Fresh produce can become contaminated with disease-causing microorganisms and chemical contaminants at every step of the production and processing chain and in a variety of ways, including through contact with contaminated process water. Water quality is critical to prevent microbial and chemical risks in any of the postharvest and processing operations related to fresh and fresh-cut fruits and vegetables. The wash process requires high volumes of water, which are usually reduced by water reuse. To maintain the microbiological quality of the process water, intervention strategies are needed. Chemical disinfection is the most common method to maintain the microbial quality of process water. However, the use of chemicals leads to the formation/accumulation of disinfection byproducts (DBPs), which can be absorbed by the washed vegetables. This is the case of trihalomethanes (THMs) and chlorates. The presence of high concentrations of DBPs in vegetables has led to an intensive debate on current disinfection practices and how DBPs may enter the food supply chain, becoming a potential health risk for consumers. To assess the risk associated with the formation/accumulation of DBPs in process water, a quantitative analysis was done. Available data have been used to develop mathematical models to predict the formation/accumulation of DBPs (chlorates and THMs) in process water due to the use of chlorine-derived compounds. Preliminary models have been developed, but adjustments are still needed to refine them. The present study contributes more information related to the development of a mathematical model for the accumulation of chlorates and THMs in process water.

16.
J Phys Chem A ; 112(10): 2074-6, 2008 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-18220374

RESUMO

The domain Green's function Monte Carlo method has been used to calculate the ground-state energy of the atoms Sc through Zn. The fixed node approximation with single-configuration explicitly correlated wave functions is used. A comparison with variational Monte Carlo energies is carried out. The quality of the ground-state energies reported here is similar to that achieved for few-electron atoms using similar techniques.

17.
Neurocirugia (Astur) ; 19(4): 322-31, 2008 Aug.
Artigo em Espanhol | MEDLINE | ID: mdl-18726042

RESUMO

OBJECTIVE: To present our experience in 80 patients with intraorbital tumours and lesions who underwent 87 osseous orbitotomies with coronal incision during a 12 year period. MATERIAL, METHODS AND RESULTS: Hemangioma was the most frequent histologic diagnosis, being the intraconical retrobulbar compartment the most common location. Bilateral presentation of lesions occurred in 7 patients. Lateral and supero-lateral orbitotomies were preferably applied (87.35%). In 90.80% of cases some kind of osteosynthesis was employed, 51.75% with bio-resorbable plates. Intraoperative exposure or dura mater breakage occurred in 10 patients. 45 transitory and 21 permanent postoperative complications were seen, being the nervous ones (diplopia and ptosis) the most frequent. Most of these were spontaneously solved in a short time period. 15 patients required multi-disciplinary collaboration with neurosurgery. CONCLUSIONS: Coronal incision allows any bone orbitotomy, with security, guarantee and good aesthetic and functional results. Lateral and supero-lateral orbitotomies provide an ideal extradural approach to the retrobulbar compartment. An approach to the apex, orbital channel and medial compartment to the optic nerve, usually requires a combined neurosurgical approach through anterior cranial fossa. Orbitotomy fixation with bio-resorbable ostheosynthesis is an alternative to titanium plates. They can even be a first choice in paediatric age. The morbidity of this surgical technique is low.


Assuntos
Órbita/cirurgia , Neoplasias Orbitárias/cirurgia , Retalhos Cirúrgicos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Humanos , Pessoa de Meia-Idade , Órbita/patologia , Complicações Pós-Operatórias , Estudos Retrospectivos , Resultado do Tratamento
18.
Actas Urol Esp ; 31(1): 38-42, 2007 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-17410985

RESUMO

OBJECTIVE: The study was focused on determining the effectiveness and reliability of using the renal resistance index as a method of diagnosing and monitoring the evolution of obstructive uropathy treatment. For this purpose, we conducted an experimental study on a homogenous group of animals that all had the same level of obstruction. MATERIAL AND METHODS: 15 healthy female pigs were used. The experiment was divided into three phases: phase I consisted of a study prior to unilateral pyeloureteral junction obstruction, performing retrograde ureteropyelography, renal B-mode ultrasound and duplex-Doppler (of both kidneys) at a level of the arcuate arteries. Then, the obstruction was performed on the animals. Phase II commenced by diagnosing the lesion, 6 weeks after the previous phase, by means of the aforementioned diagnostic methods. Finally, the endourological treatment was completed. Animals were monitored (Phase III) 15 weeks after the endopyelotomy, using the same methods as in the study, by assessing the urinary tract (fluoroscopy) and both kidneys by determining the renal resistance index and ratio. RESULTS: All the animals in the study showed signs of urinary obstruction on radiology and renal ultrasound 6 weeks after ureteral ligature. After treatment and follow-up, all animals showed signs of having recovered from the obstructive uropathy. Values of deltaRI during the 3 phases are detailed below. Fase I deltaIR = 0.01, Fase II deltaIR = 0.11, Fase III deltaIR = 0.02. CONCLUSION: RI determination using duplex-Doppler is effective for distinguishing obstructive dilatation using non-invasive techniques. However, this parameter provides very slight differences and it can also be influenced by too many direct and indirect factors (observational, patient age, anaesthesia, haemodynamic parameters, etc.), to supplant the classic diagnostic methods.


Assuntos
Obstrução Ureteral/diagnóstico , Obstrução Ureteral/fisiopatologia , Animais , Feminino , Suínos , Resistência Vascular
19.
Philos Trans A Math Phys Eng Sci ; 375(2085)2017 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-27956510

RESUMO

An analysis of the spalling technique of concrete bars using the modified Hopkinson bar was carried out. A new experimental configuration is proposed adding some variations to previous works. An increased length for concrete specimens was chosen and finite-element analysis was used for designing a conic projectile to obtain a suitable triangular impulse wave. The aim of this initial work is to establish an experimental framework which allows a simple and direct analysis of concrete subjected to high strain rates. The efforts and configuration of these primary tests, as well as the selected geometry and dimensions for the different elements, have been focused to achieve a simple way of identifying the fracture position and so the tensile strength of tested specimens. This dynamic tensile strength can be easily compared with previous values published in literature giving an idea of the accuracy of the method and technique proposed and the possibility to extend it in a near future to obtain other mechanical properties such as the fracture energy. The tests were instrumented with strain gauges, accelerometers and high-speed camera in order to validate the results by different ways. Results of the dynamic tensile strength of the tested concrete are presented.This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

20.
Actas Urol Esp ; 30(5): 443-50, 2006 May.
Artigo em Espanhol | MEDLINE | ID: mdl-16884092

RESUMO

We present the experience of the Minimally Invasive Surgery Centre (MISC) in the development of a modular training model in laparoscopic surgery. The experience analysis includes the description of the training objectives, the learning process of simple and advance laparoscopic urologic techniques, as well as some current and future considerations before applying the laparoscopic techniques. This learning program pretends to optimize the knowledge of the surgeon and the clinical practice of these surgical techniques. The phases of the learning process have been classified in four levels, which include different modules and models and whose application will depend on the experience and surgical skills. This pyramidal training system permits the student to advance step by step through each level depending on her surgical skills. We have presented our experience in twelve courses about laparoscopic urology and four courses of laparoscopic radical prostatectomy, in which more than 300 urologists have assisted. Furthermore, some Spanish Urology Units have been developing special experimental training programs on laparoscopic radical prostatectomy, partial nephrectomy or laparoscopic dismembered pyeloplasty with Anderson-Hynes technique. It has been previously described that laparoscopic modular learning constitutes a very useful concept to avoid problems related to an incomplete and incorrect learning process. Also it seems clear that the laparoscopic training reduces the learning curve in laparoscopic urologic techniques.


Assuntos
Laparoscopia , Modelos Animais , Procedimentos Cirúrgicos Urológicos/educação , Procedimentos Cirúrgicos Urológicos/métodos , Animais
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