39 research outputs found

    Ftalatos y efectos en la salud

    Get PDF
    Los plastificantes son aditivos que se mezclan con algunos plásticos, especialmente con cloruro de polivinilo (CPV) para incrementar su elasticidad. Los plastificantes de uso más común son los derivados del ácido ftálico o ftalatos. Sin embargo, al no estar químicamente ligados a la matriz plástica, los ftalatos pueden abandonar el material y provocar daños a la salud y al ambiente. Aunque, es importante considerar que actualmente no existe evidencia clara sobre su toxicidad en seres humanos, en este artículo se presenta una revisión sobre la utilización y el riesgo en el empleo de ftalatos. Se discuten también las evidencias presentadas sobre su toxicidad y con base en lo anterior se recomienda investigar la magnitud de este problema en México, país productor de PCV plastificado

    Exposición infantil a plastificantes potencialmente tóxicos en productos de uso oral

    Get PDF
    Objetivo. Determinar la prevalencia en el uso de productos infantiles orales entre menores de tres años de edad y medir su concentración de ftalatos, sustancias potencialmente tóxicas. Material y métodos. Se realizó, en 1999, una entrevista domiciliaria a 199 madres de niños del área metropolitana de la ciudad de Toluca. Por cromatografía de gases se identificaron y cuantificaron diversos ftalatos de productos de uso oral empleados por los niños participantes y se estimó la contribución de estas fuentes a la ingesta diaria de ftalatos. Resultados. La prevalencia de uso de estos productos fue de 13%, siendo mayor entre los niños, menores de 18 meses de edad, pertenecientes al estrato socioeconómico bajo. Las concentraciones variaron desde trazas hasta 67.0% del peso. La exposición media calculada proveniente de los productos manufacturados con policloruro de vinilo y ftalatos fue de 13.94 mg/ kg de peso/día, IC 95% (9.08, 18.89). Conclusiones. La exposición a ftalatos proveniente de productos para chupar o morder se encuentra dentro de los límites reportados en otros países; sin embargo, otras fuentes pueden incrementarla. Dado que algunos ftalatos han mostrado ser tóxicos en el sistema reproductivo, y este potencial efecto es plausible en el hombre, es necesaria la investigación de otras fuentes y determinar la exposición total a través de biomarcadores

    Exposición a ftalatos por procedimientos médicos en varones recién nacidos

    No full text
    Aunque la exposición a plastificantes del grupo de los ftalatos es general en la población, se sospecha que algunos grupos de infantes pueden exponerse a niveles potencialmente tóxicos. Se realizó un estudio exploratorio observacional con el propósito de determinar si los plásticos empleados en procedimientos médicos invasivos exponen a los niños recién nacidos a ftalatos a niveles mayores a los observados en la población general. Se midieron las concentraciones urinarias de los metabolitos de los ftalatos mas comúnmente empleados, ftalato de monometilo (FMM), ftalato de monobutilo (FMB), ftalato de monoetilhexilo (FMEH), ftalato de monoetilo (FME) y ftalato de monooctilo (FMO) en 30 recién nacidos sometidos a procedimientos de terapia intensiva neonatal y 30 niños del servicio de cunero que no recibieron ninguna intervención médica invasiva. La media del FMEH en orina de los niños sometidos a terapia intensiva neonatal fue de 46.82 µg/L y de 5.19 µg/L para los niños de cunero (p< .001). El FMEH es el metabolito primario del ftalato de di2( etilhexilo) (FDEH), principal plastificante utilizado en la fabricación de equipos médicos. Los resultados de este estudio exploratorio muestran elevados niveles de exposición en el grupo de recién nacidos sometidos a tratamientos en terapia intensiva neonatal comparados con el grupo de recién nacidos de cunero. El significado de esta exposición en la salud de estos niños es todavía incierto

    Highly-parallelized simulation of a pixelated LArTPC on a GPU

    No full text
    The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10310^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

    The DUNE Far Detector Vertical Drift Technology, Technical Design Report

    No full text
    International audienceDUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals

    The DUNE Far Detector Vertical Drift Technology, Technical Design Report

    No full text
    International audienceDUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals

    Highly-parallelized simulation of a pixelated LArTPC on a GPU

    No full text
    The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10310^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

    The DUNE Far Detector Vertical Drift Technology, Technical Design Report

    No full text
    DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals

    Highly-parallelized simulation of a pixelated LArTPC on a GPU

    No full text
    The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10310^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

    The DUNE Far Detector Vertical Drift Technology, Technical Design Report

    No full text
    International audienceDUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals
    corecore