Temperature-tuned Maxwell-Boltzmann neutron spectra for kT ranging from 30 up to 50 keV for nuclear astrophysics studies.

The need of neutron capture cross section measurements for astrophysics motivates present work, where calculations to generate stellar neutron spectra at different temperatures are performed. The accelerator-based (7)Li(p,n)(7)Be reaction is used. Shaping the proton beam energy and the sample covering a specific solid angle, neutron activation for measuring stellar-averaged capture cross section can be done. High-quality Maxwell-Boltzmann neutron spectra are predicted. Assuming a general behavior of the neutron capture cross section a weighted fit of the spectrum to Maxwell-Boltzmann distributions is successfully introduced.

[Cerebral oximetry monitoring during bypass surgery: can the approach be changed?]. / Monitorización de la oximetría cerebral durante cirugía extracorpórea: puede modificar la actitud quirúrgica.

We describe the detection of postoperative neurologic complications by means of monitoring cerebral oximetry during cardiac surgery. A 54-year-old man underwent emergency surgery for aortic dissection, type A. Cerebral oximetry was monitored by near-infrared spectroscopy. At the start of total cardiopulmonary bypass through the axillary artery, cerebral oxygen saturation fell more than 50% from baseline in both hemispheres. Saturation did not improve on optimizing factors that influence cerebral blood flow. Improvement came only when the recently inserted arterial cannula was switched to the ascending aortic prosthetic graft. After surgery, the patient was diagnosed with anoxic brain injury. We believe that the detected fall in cerebral oxygen saturation during axillary artery cannulization probably coincided with the occurrence of anoxic brain injury.

Monitorización de la oximetría cerebral durante cirugía extracorpórea ¿puede modificar la actitud quirúrgica / Cerebral oximetry monitoring during bypass surgery: can the approach be changed?

OBJETIVO: Describir la detección de complicacionesneurológicas postoperatorias en cirugía cardiaca pormedio de la monitorización intraoperatoria de la oximetríacerebral.CASO CLÍNICO: Presentamos el caso de un varón de 54años intervenido de urgencia con el diagnóstico de disecciónaórtica tipo A. Durante la cirugía se monitorizó laoximetría cerebral mediante la tecnología NIRS (NearInfrared Spectroscopy: espectroscopía óptica con unabanda cercana al infrarrojo).RESULTADOS Y CONCLUSIONES: Al iniciarse la derivacióncardiopulmonar total a través de la arteria axilar, seapreció un descenso superior al 50% respecto a la líneabasal de los valores de saturación regional cerebral deoxígeno en ambos hemisferios cerebrales. Estos valoresno mejoraron al optimizar los factores que influyen en laregulación del flujo sanguíneo cerebral, y sólo se modificaronal cambiar la canulación arterial a la prótesis deaorta ascendente recién colocada. En el postoperatorio elpaciente fue diagnosticado de encefalopatía anóxica. Ennuestra opinión, el descenso mantenido de los valores desaturación regional cerebral de oxígeno observadodurante la canulación axilar, podría corresponder con elepisodio de anoxia cerebral(AU)

We describe the detection of postoperative neurologiccomplications by means of monitoring cerebral oximetryduring cardiac surgery. A 54-year-old man underwentemergency surgery for aortic dissection, type A.Cerebral oximetry was monitored by near-infraredspectroscopy. At the start of total cardiopulmonarybypass through the axillary artery, cerebral oxygensaturation fell more than 50% from baseline in bothhemispheres. Saturation did not improve on optimizingfactors that influence cerebral blood flow. Improvementcame only when the recently inserted arterial cannulawas switched to the ascending aortic prosthetic graft.After surgery, the patient was diagnosed with anoxicbrain injury. We believe that the detected fall in cerebraloxygen saturation during axillary artery cannulizationprobably coincided with the occurrence of anoxic braininjury(AU)

Cuerpo extraño cervical: paciente afortunado / Cervical foreign body: a lucky patient

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[Thyroid nodules: factors suggestive of malignancy]. / Nódulos tiroideos: factores sugerentes de malignidad.

The evaluation and management of thyroid nodules is a common problem in medicine. In a review of 250 cases of thyroid disease seen at the 12 de Octubre Hospital (Madrid, Spain), 191 cases of solitary nodules and multinodular goiter were analyzed. The clinical findings, complementary studies, and postoperative histology were analyzed to determine the parameters most closely related to malignant thyroid processes. The overall rate of malignancy was 22.5%. Major clinical factors associated with malignancy were fixation to deep structures, cervical lymph node enlargement, and paralysis of the vocal cords. None of the complementary tests was absolutely reliable in excluding malignancy, but fine needle aspiration biopsy, in spite of its limitations, was the best diagnostic tool. Surgery is indicated if the benignity of a nodule cannot be confirmed.

[Response of cartilaginous neoplasms of the larynx to surgery and alternative therapies]. / Comportamiento de las neoplasias cartilaginosas de la laringe frente al tratamiento quirúrgico y las terapéuticas alternativas.

Three primary cartilaginous tumors of the larynx are reported: two chondrosarcomas (including an undifferentiated chondrosarcoma with prolonged survival) and one chondroma. The need for accurate histological staging, only possible after surgery, is emphasized. Surgery is teh preferred initial treatment.

[Radiological criteria for laryngeal tumors and cervical metastases]. / Criterios radiológicos en los tumores de laringe y sus metástasis cervicales.

Radiological techniques are important for studying the extension of laryngeal tumors. CT and MRI yield high-quality images with few artifacts that can be studied quickly. We reviewed the fundamental criteria for radiologic study of these tumors by ear, nose, and throat specialists on the basis of our personal experience and the literature.