ABSTRACT
An Omega-like beam configuration is considered where the 60-beam layout can be separated into two independent sub-configurations with 24 and 36 laser beams, each minimizing direct drive illumination non-uniformity. Two different laser focal spot profiles, one associated with each configuration, are proposed to apply the zooming technique in order to increase the laser-target coupling efficiency. This approach is used by 1D hydrodynamics simulations of the implosion of a direct-drive capsule characterized by a relatively large aspect ratio A = 7 and an optimized laser pulse shape delivering a maximum of 30 TW and 30 kJ, with different temporal pulse shapes in each of the two sets of beams. It is shown that zooming allows for an optimistic 1D thermonuclear energy gain greater than one while without zooming the thermonuclear gain remains largely below one. While this is incompatible with the as-built Omega laser, it provides a promising option for a future intermediate-energy direct drive laser system.
ABSTRACT
BACKGROUND: Childhood leukemia is the most common childhood cancer. To date, few risk factors related to predisposition have been identified; therefore, new hypotheses should be considered. OBJECTIVE: To explore the possible relationship of residential proximity to urban green spaces on childhood leukemia. METHODS: We conducted a population-based case control study in the metropolitan area of Madrid from 2000 to 2015. It included 383 incident cases and 1935 controls, individually matched by birth year, sex and area of residence. Using the geographical coordinates of the participants' home residences, we built a proxy for exposure with four distances (250 m, 500 m, 750 m and 1 km) to urban parks (UPs) and urban wooded areas (UWAs). We employed logistic regression models to determinate the effect of them on childhood leukemia adjusting for environmental and socio-demographic covariates. RESULTS: we found a reduction in childhood leukemia incidence at a distance of 250 m from UPs (OR = 0.78; 95%CI = 0.62-0.98), as well as a reduction of the incidence in the Q3 and Q4 quintiles for exposure to UWAs, in the 250 m and 500 m buffers respectively (Q3 (250 m): OR = 0.69; 95%CI = 0.48-1.00; and, Q4 (500 m): OR = 0.69; 95%CI = 0.48-0.99). CONCLUSIONS: Our results suggest a possible association between lower incidence of childhood leukemia and proximity to different forms of urban green space. This study is a first approach to the possible urban green space effects on childhood leukemia so is necessary to continue studying this spaces taking into account more individual data and other environmental risk factors.
Subject(s)
Leukemia , Parks, Recreational , Case-Control Studies , Housing , Humans , Leukemia/epidemiology , Residence Characteristics , Risk FactorsABSTRACT
Pamidronate, alendronate, APHBP and neridronate are a group of drugs, known as second-generation bisphosphonates (2G-BPs), commonly used in the treatment of bone-resorption disorders, and recently their use has been related to some collateral side effects. The therapeutic activity of 2G-BPs is related to the inhibition of the human Farnesyl Pyrophosphate Synthase (hFPPS). Available inhibitory activity values show that 2G-BPs act time-dependently, showing big differences in their initial inhibitory activities but similar final IC50 values. However, there is a lack of information explaining this similar final inhibitory potency. Although different residues have been identified in the stabilization of the R2 side chain of 2G-BPs into the active site, similar free binding energies were obtained that highlighted a similar stability of the ternary complexes, which in turns justified the similar IC50 values reported. Free binding energy calculations also demonstrated that the union of 2G-BPs to the active site were 38 to 54 kcal mol-1 energetically more favourable than the union of the natural substrate, which is the basis of the inhibition potency of the hFPPS activity.
Subject(s)
Bone Density Conservation Agents/chemistry , Diphosphonates/chemistry , Geranyltranstransferase/antagonists & inhibitors , Hemiterpenes/chemistry , Molecular Dynamics Simulation , Organophosphorus Compounds/chemistry , Alendronate/chemistry , Binding Sites , Drug Discovery , Geranyltranstransferase/chemistry , Humans , Pamidronate , Protein Binding , Structure-Activity Relationship , ThermodynamicsABSTRACT
Ultraintense laser pulses with a few-cycle rising edge are ideally suited to accelerating ions from ultrathin foils, and achieving such pulses in practice represents a formidable challenge. We show that such pulses can be obtained using sufficiently strong and well-controlled relativistic nonlinearities in spatially well-defined near-critical-density plasmas. The resulting ultraintense pulses with an extremely steep rising edge give rise to significantly enhanced carbon ion energies consistent with a transition to radiation pressure acceleration.
ABSTRACT
We report on the proton acceleration studies from thin metallic foils of varying atomic number (Z) and thicknesses, investigated using a 45 fs, 10 TW Ti:sapphire laser system. An optimum foil thickness was observed for efficient proton acceleration for our laser conditions, dictated by the laser ASE prepulse and hot electron propagation behavior inside the material. The hydrodynamic simulations for ASE prepulse support the experimental observation. The observed maximum proton energy at different thicknesses for a given element is in good agreement with the reported scaling laws. The results with foils of different atomic number Z suggest that a judicious choice of the foil material can enhance the proton acceleration efficiency, resulting into higher proton energy.
Subject(s)
Lasers , Protons , Radiation , Aluminum Compounds , Aluminum Oxide , Computer Simulation , Copper , Electrons , Gold Compounds , Hydrodynamics , Nickel , Tantalum , TitaniumABSTRACT
BACKGROUND: The characteristics of respiratory tuberculosis (TB) favour the appearance of clusters of cases in space and time. It is important for public health authorities to know which clusters occur randomly and which merit further investigation. OBJECTIVE: To detect spatial and spatio-temporal clusters of respiratory TB in Spain during the period from 1 January 2008 to 31 December 2010. MATERIALS AND METHODS: Retrospective spatio-temporal study of respiratory TB cases reported to Spain's National Epidemiological Surveillance Network from 2008 to 2010, at a municipal level. We used the purely spatial and space-time Scan statistic estimators. All analyses were adjusted for age and sex. RESULTS: The spatial cluster analysis detected 28 significant clusters and the spatio-temporal cluster analysis detected 20 significant clusters. The most likely spatial cluster comprised seven municipalities in the Greater Barcelona Area. Most space-time clusters were situated in the same area, and were detected between 1 April 2008 and 31 March 2009. CONCLUSION: The distribution of TB clusters as shown by the proposed models furnishes a spatial pattern of the distribution of the disease. The two methods used can be a useful tool for analysing the distribution of respiratory TB in Spain.
Subject(s)
Models, Theoretical , Tuberculosis/epidemiology , Cluster Analysis , Female , Humans , Male , Population Surveillance , Public Health , Retrospective Studies , Spain/epidemiology , Spatio-Temporal AnalysisABSTRACT
In Spain hepatitis A is a compulsory notifiable disease and individual cases are reported to the national epidemiological surveillance network. Incidence rates show variations in different regions. The aim of this study was to analyse the space-time pattern of hepatitis A risk at municipal level in Spain and at global and local levels during the period 1997-2007. At global level we used two estimates of risk: the standardized incidence ratio (SIR) and the posterior probability that the smoothed relative risk is >1 (PP). At local level we used the scan statistic method to analyse the space-time clusters. The SIR and significant PP (>0·8) showed the highest risk concentrated in areas of the Mediterranean coast. The most likely cluster gave a relative risk of 53·530. These spatial statistics methodologies can be complementary tools in the epidemiological surveillance of infectious diseases.
Subject(s)
Hepatitis A/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Geography , Humans , Incidence , Infant , Infant, Newborn , Male , Middle Aged , Retrospective Studies , Risk Assessment , Spain/epidemiology , Time Factors , Young AdultABSTRACT
Fast electrons produced by a 10 ps, 160 J laser pulse through laser-compressed plastic cylinders are studied experimentally and numerically in the context of fast ignition. K(α)-emission images reveal a collimated or scattered electron beam depending on the initial density and the compression timing. A numerical transport model shows that implosion-driven electrical resistivity gradients induce strong magnetic fields able to guide the electrons. The good agreement with measured beam sizes provides the first experimental evidence for fast-electron magnetic collimation in laser-compressed matter.
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Objetivo. Este artículo presenta dos estudios sobre la relación entre el número de preguntas de un examen y sus resultados. Estos dos estudios se realizaron en respuesta a dos problemas concretos presentados en dos facultades de ciencias de la salud de dos universidades catalanas. Sujetos y métodos. El primer estudio, realizado en la Facultad de Medicina de la Universitat Autònoma de Barcelona, compara los resultados reales obtenidos en pruebas de elección múltiple en tres asignaturas con los resultados que hubieran obtenido los estudiantes con la mitad de las preguntas. La dificultad del examen en ambas situaciones fue prácticamente la misma y los resultados académicos también fueron similares. El segundo estudio, llevado a cabo en la Facultad de Ciencias de la Salud y de la Vida de la Universitat Pompeu Fabra de Barcelona, compara los resultados reales obtenidos en pruebas de ensayo de dos asignaturas de los estudios de Biología con los hipotéticos que se hubieran obtenido con la mitad de las preguntas. Los resultados obtenidos globalmente fueron muy parecidos. Conclusión. La conclusión general del estudio es que la evaluación del rendimiento académico no dependería fundamentalmente del número de preguntas y que sería más importante buscar la representatividad y relevancia de éstas (AU)
Aim. This paper resents two studies about the relationship between the number of questions that appear in an exam and their results. These studies have been done in response to two concrete problems found in two Spanish universities. Subjects and methods. The first study, done at the Faculty of Medicine of the Autonomous University of Barcelona, compared the real results achieved in three subjects which use MCQ-tests with the theoretical results which the students would have achieved if half of the questions had been used. The difficulty of the exams in both situations was practically the same and the students academic results were very similar in both situations. The second study, carried out at the Faculty of Health and Life Sciences at the Pompeu Fabra University of Barcelona, compared the real academic results in two subjects which use free response questions with the supposed ones with half of the questions of the exam in two subjects which use many essay questions. The results obtained by the students were practically identical. Conclusion. Our general conclusion is that in the evaluation of academic performance, it is more important how relevant and representative the questions are than the number of them (AU)
Subject(s)
Humans , Educational Measurement/methods , 51654/methods , Education, Medical , Schools, Medical/trends , Test Taking Skills , AchievementABSTRACT
We report on experimental studies of ion acceleration from spherical targets of diameter 15 microm irradiated by ultraintense (1x10(20) W/cm2) pulses from a 20-TW Ti:sapphire laser system. A highly directed proton beam with plateau-shaped spectrum extending to energies up to 8 MeV is observed in the laser propagation direction. This beam arises from acceleration in a converging shock launched by the laser, which is confirmed by 3-dimensional particle-in-cell simulations. The temporal evolution of the shock-front curvature shows excellent agreement with a two-dimensional radiation pressure model.
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Introducción. Los aneurismas de la arteria esplénica son lesiones vasculares infrecuentes, aunque representanel 60% de todos los aneurismas viscerales. Suelen ser clínicamente asintomáticos, pero en caso de rotura espontánease manifiestan como un cuadro de abdomen agudo y shock, requiriendo un diagnóstico temprano y una actitud quirúrgicainmediata. Caso clínico. Varón de 64 años de edad con una rotura de un aneurisma de la arteria esplénica que precisóintervención quirúrgica urgente con su resección y esplenectomía
Introduction. Aneurysms in the splenic artery are rare vascular lesions, although they account for 60% of allvisceral aneurysms. They are usually clinically asymptomatic, but when spontaneous rupture occurs they manifest in theform of acute symptoms in the abdomen and shock, and therefore require an early diagnosis and immediate surgicalintervention. Case report. A 64-year-old male with a ruptured aneurysm in the splenic artery that required urgent surgeryto excise it and a splenectomy
Subject(s)
Humans , Male , Middle Aged , Aneurysm, Ruptured/diagnosis , Aneurysm, Ruptured/surgery , Splenic Artery/pathology , Splenic Artery/surgery , Tomography, X-Ray Computed , SplenectomyABSTRACT
A fully nonlinear sharp-boundary model of the ablative Rayleigh-Taylor instability is derived and closed in a similar way to the self-consistent closure of the linear theory. It contains the stabilizing effect of ablation and accurately reproduces the results of 2D DRACO simulations. The single-mode saturation amplitude, bubble and spike evolutions in the nonlinear regimes, and the seeding of long-wavelength modes via mode coupling are determined and compared with the classical theory without ablation. Nonlinear stability above the linear cutoff is also predicted.
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Objetivo. Valorar si tras la pancreatitis aguda biliar existía una insuficiencia pancreática endocrina y si este posible déficit se relacionaba con la gravedad del episodio. Pacientes y métodos. Sesenta y tres pacientes con pancreatitis aguda biliar fueron estudiados prospectiva y consecutivamente, 46 mujeres (73 por ciento) y 17 varones (27 por ciento); 45 casos eran leves y 18, graves. Todos ellos fueron colecistectomizados, ninguno fue sometido a necrosectomía o pancreatectomía. Durante la fase aguda se valoró la gravedad siguiendo los criterios de Atlanta, la existencia de necrosis y su porcentaje determinado por tomografía computarizada dinámica. Durante el seguimiento se valoró la función pancreática endocrina al mes, a los 6 meses y al año del episodio de la pancreatitis aguda mediante diversos tests de función pancreática. Resultados. Al mes de la pancreatitis aguda biliar se detectaron alteraciones endocrinas en el 50 por ciento de los casos, disminuyendo al sexto mes al 30 por ciento, persistiendo al año de la pancreatitis aguda en el 25 por ciento de los pacientes; sin embargo, éstas no eran secundarias a la pancreatitis, puesto que el test de arginina presentaba valores dentro del rango de la normalidad. El análisis estadístico realizado a fin de valorar la relación existente entre la gravedad de la pancreatitis aguda y los diversos tests de función pancreática endocrina demostró que no existían diferencias significativas (p > 0,05).Conclusión. La función pancreática endocrina retorna a la normalidad después de un episodio de pancreatitis aguda de origen biliar tras haberse eliminado la causa primaria de la enfermedad, no detectándose alteración de la reserva funcional endocrina secundaria a la pancreatitis, y no existiendo relación entre dicha función y la gravedad de la enfermedad (AU)
Subject(s)
Adult , Aged , Female , Male , Middle Aged , Humans , Pancreatitis/complications , Pancreatitis/diagnosis , Cholecystectomy/methods , Tomography, Emission-Computed , Arginine/administration & dosage , Arginine , Exocrine Pancreatic Insufficiency/complications , Exocrine Pancreatic Insufficiency/diagnosis , Prospective Studies , C-Peptide , Pancreatitis/classification , Pancreatitis/epidemiology , Pancreatitis/pathology , Pancreas/pathologyABSTRACT
En nuestra experiencia el paciente portador de un síndrome posgastrectomía suele presentar alguna de las siguientes características: el resultado de la primera intervención no se correspondió con las expectativas que se le prometieron, generalmente se han sometido a una o varias reintervenciones sin obtener ninguna mejoría o, en ocasiones, son pacientes con una neurosis de renta. Además, las actitudes terapéuticas adoptadas también reúnen una serie de características comunes: la indicación quirúrgica de la primera intervención no fue la adecuada, la primera intervención no se realizó de forma correcta, generalmente no se practicó un estudio funcional suficiente, las reintervenciones se planificaron basándose en criterios anatómicos o no se valoró la personalidad del paciente, ni su entorno sociofamiliar. Es evidente que la cirugía gástrica resectiva ha disminuido enormemente en los últimos años, viéndose limitada casi a la cirugía de las neoplasias. No obstante, aún seguimos atendiendo a algún enfermo aquejado de molestias encuadrables dentro del conocido síndrome posgastrectomía: síndrome de asa, dumping, gastritis alcalina, úlceras recidivantes, diarreas, malnutriciones, anemias, etc. Se trata de cuadros bien estudiados, sobre los que se ha aportado poco en los últimos años. Sin embargo, vemos aparecer muevas patologías secundarias a intervenciones gástricas generalmente no resectivas, por lo que sería más adecuado hablar de patología poscirugía gástrica; evidentemente se trata de un término mucho más amplio que el del síndrome posgastrectomía, por lo que en esta revisión nos ocupamos parcialmente de él, renunciando a la revisión de sus aspectos más clásicos, para centrarnos en algunos que hoy día son frecuentes y que hemos estudiado: el síndrome de la Y de Roux, la patología secundaria a la cirugía bariátrica y la que puede presentarse tras la cirugía del reflujo gastroesofágico (AU)
Subject(s)
Humans , Gastrectomy , Postoperative ComplicationsSubject(s)
Education, Medical, Undergraduate , Students, Medical/psychology , Curriculum , Evaluation Studies as Topic , Female , Humans , Male , Sex Factors , SpainABSTRACT
We have studied 191 protocolized colorectal cancer patients, analyzing the prognostic factors described in the literature as being important to long-term survival. Of the data studied, sex, age, duration of symptoms, tumor location, tumor extension within the circumference of the bowel lumen, and the surgical technique employed, all showed differences in terms of five-year survival, but without reaching statistical significance. The factors with statistically significant prognostic value were first symptoms, occlusion, perforation, primary tumor size and configuration, lymph node involvement, degree of wall infiltration, presence of emboli, degree of differentiation and Scarff index. In view of these results, we consider that the evaluation of bowel wall infiltration, lymph node involvement, venous and/or lymphatic embolization, and tumor differentiation is necessary to establish long-term prognosis in these patients. The remaining factors lack prognostic value.
Subject(s)
Colorectal Neoplasms/mortality , Female , Humans , Life Tables , Male , Middle Aged , Prognosis , Spain/epidemiology , Survival Analysis , Survival Rate , Time FactorsSubject(s)
Health Promotion/methods , Health Services for the Aged , Aged , Health Education , Health Priorities , Humans , Models, Nursing , Nursing ProcessABSTRACT
The conversion of ion beam energy into thermal x-ray radiation by means of stretched cylindrical plasma volumes is studied by analytic modeling and numerical simulation. The analysis is restricted to one-dimensional radiation hydrodynamics. Scaling relations for different materials are derived. Due to equation-of-state properties, high-Z material turns out superior for achieving high conversion efficiency. The paper provides practical answers for thermal x-ray generation with intense heavy ion beams. Deposition powers in the order of 10l6 W/g are required for applications to ion beam inertial confinement fusion.