Assessment of Singularities in the EEG During A-Phases of Sleep Based on Wavelet Decomposition.

Electroencephalography (EEG) signals convey information related to different processes that take place in the brain. From the EEG fluctuations during sleep, it is possible to establish the sleep stages and identify short events, commonly related to a specific physiological process or pathology. Some of these short events (called A-phases) present an organization and build up the concept of the Cyclic Alternating Pattern (CAP) phenomenon. In general, the A-phases abruptly modify the EEG fluctuations, and a singular behavior could occur. With the aim to quantify the abrupt changes during A-phases, in this work the wavelet analysis is considered to compute Hölder exponents, which measure the singularity strength. We considered time windows of 2s outside and 5s inside A-phases onset (or offset). A total number of 5121 A-phases from 9 healthy participants and 10 patients with periodic leg movements were analyzed. Within an A-phase the Hölder numerical value tends to be 0.6, which implies a less abrupt singularity. Whereas outside of A-phases, it is observed that the Hölder value is approximately equal to 0.3, which implies stronger singularities, i.e., a more evident discontinuity in the signal behavior. In addition, it seems that the number of singularities increases inside of A-phases. The numerical results suggest that the EEG naturally conveys singularities modified by the A-phase occurrence, and this information could help to conceptualize the CAP phenomenon from a new perspective based on the sharpness of the EEG instead of the oscillatory way.

Caracterización clínica y tomográfica de pacientes hospitalizados con COVID-19 / Clinical and tomographic characterization of patients hospitalized with COVID-19

OBJETIVO: Realizar una caracterización clínica y por imágenes a pacientes hospitalizados por COVID-19 y analizar si existen predictores de riesgo asociados con una mayor gravedad. MÉTODO: Estudio observacional, retrospectivo. Se incluyeron pacientes hospitalizados con COVID-19, entre abril y julio de 2020. Se registraron datos demográficos, comorbilidades, exámenes de laboratorio, tipo de compromiso en tomografía computada (TC) de tórax, terapias recibidas y tipo de soporte respiratorio. En el análisis estadístico para identificar factores de riesgo se utilizó test χ2 de Pearson o test de Fisher para comparar variables categóricas y test de Mann-Whitney para comparar variables continuas. RESULTADOS: Se analizaron 164 pacientes. La mediana de edad fue de 57 años (rango 21 a 89). 111 pacientes (68%) de género masculino y mediana de 7 días de síntomas previo al ingreso (rango 1 a 23). 68 pacientes (41%) tienen obesidad (significativamente mayor en pacientes < 60 años, p = 0,026), 56 (34%) hipertensión arterial (HTA) y 43 (26%) diabetes. El patrón predominante en la TC de ingreso fue de vidrio esmerilado (VE) con "crazy paving" (35%) y luego VE puro (28%). Como indicador de gravedad se tomó en cuenta el tipo de soporte ventilatorio requerido: 51 pacientes (31%) requieren soporte ventilatorio no invasivo (cánula nasal de alto flujo o VMNI) y 19 (11%) ventilación invasiva (VMI). Las variables predictoras de gravedad, estadísticamente significativas, fueron: HTA (p = 0,001), Diabetes Mellitus (p = 0,001) y Obesidad. (p = 0,002). CONCLUSIONES: Los pacientes hospitalizados por COVID 19 con mayor riesgo de evolución tórpida, del punto de vista respiratorio, fueron los pacientes obesos, hipertensos y diabéticos.

OBJECTIVE: To perform a clinical and imaging characterization in patients hospitalized for COVID-19 and to analyze whether there are risk predictors associated with greater severity of the condition. METHOD: Observational, retrospective study. Patients hospitalized with COVID-19 were included between April and July 2020. Demographic data, comorbidities, laboratory tests, tomographic pattern in thorax tomography (TC), therapies received, and type of respiratory support were recorded. In the statistical analysis to identify risk factors, we used Pearson's χ2 test or Fisher's test to compare categorical variables and Mann-Whitney test to compare continuous variables. RESULTS: 164 patients were analyzed. Median age was 57 years (21 to 89). 111 patients (68%) were male and a median of 7 days of symptoms prior to admission (1 to 23). 68 patients (41%) have obesity (significantly higher in patients < 60 years, p = 0.026), 56 (34%) arterial hypertension (HT) and 43 (26%) with diabetes mellitus. The predominant pattern in the admission CT scan was ground glass opacity (GGO) with "crazy paving" (35%) and then pure GGO (28%). Type of ventilatory support required was considered as an indicator of severity. 51 patients (31%) require non-invasive ventilatory support (high-flow nasal cannula or NIMV) and 19 (11%) invasive ventilation (IMV). The statistically significant predictor variables of severity were HT (p = 0.001), Diabetes Mellitus (p = 0.001) and Obesity. (p = 0.002). CONCLUSIONS: Patients hospitalized for COVID 19 with the highest risk of respiratory torpid evolution were obese, hypertensive and diabetic patients

Post-synthetic halide conversion and selective halogen capture in hybrid perovskites.

Reaction with halogen vapor allows us to post-synthetically exchange halides in both three- (3D) and two-dimensional (2D) organic-inorganic metal-halide perovskites. Films of 3D Pb-I perovskites cleanly convert to films of Pb-Br or Pb-Cl perovskites upon exposure to Br2 or Cl2 gas, respectively. This gas-solid reaction provides a simple method to produce the high-quality Pb-Br or Pb-Cl perovskite films required for optoelectronic applications. Reactivity with halogens can be extended to the organic layers in 2D metal-halide perovskites. Here, terminal alkene groups placed between the inorganic layers can capture Br2 gas through chemisorption to form dibromoalkanes. This reaction's selectivity for Br2 over I2 allows us to scrub Br2 to obtain high-purity I2 gas streams. We also observe unusual halogen transfer between the inorganic and organic layers within a single perovskite structure. Remarkably, the perovskite's crystallinity is retained during these massive structural rearrangements.

Miositis osificante circunscrita bilateral de cadera en paciente con TEC severo complicado: caso clínico y revisión de literatura / Myositis ossificans circumscripta of bilateral hip in patient with severe complicated TBI: case report and literature review

To describe the pathology Myosistis ossificans circumscripta (MOC) in a patients with severe traumatic brain injury (TBI) complicated, emphasizing clinical features, imaging utility, surgery and postoperative prophylaxis with indomethacin. Introduction: MOC corresponds to heterotopic soft tissue calcification secondary to direct or repetitive trauma, in close relationship with TBI. The initial study is radiological, but computed tomography (CT) and magnetic resonance imaging (MRI) are the studies of choice. Case report: Male, 33 years old, polytraumatized with severe TBI complicated. That one year after his discharge from the hospital, beban with increased volume inguinocrural bilateral, progressive, compatible with bitateral MOC Brooker 4. Surgical resection im two stages, both with postoperative prophylaxis with Indomethacin. It evolved with excellent response, symtomatic remission without recurrence after two years of follow-up. Discussion: MOC is a rare disease, where the combined medical surgical management is of utmost importance when treating this disease and prevent recurrences...

Describir la patología Miositis Osificante Circunscrita (MOC) en paciente con traumatismo encéfalo craneano (TEC) severo complicado, enfatizando características clínicas, utilidad de imágenes, tratamiento quirúrgico y profilaxis postoperatoria con Indometacina. Introducción: MOC corresponde a la calcificación heterotópica de tejidos blandos secundaria a traumatismo directo o repetitivo, en estrecha relación con TEC. El estudio inicial es radiológico por tomografía computada (TC) y resonancia magnética (RNM), son los estudios a elección. Presentación de cado: Hombre, 33 años, politraumatizado, con TEC severo complicado. Que tras un año de alta comenzó con aumento de volumen inguinocrural bilateral, progresivo, compatible con MOC bilateral Brooker 4. Resección quirúrgica de dos tiempos, ambas con profilaxis postoperatoria con Indometacina. Evolucionó con excelente respuesta, remisión sintomática y sin recurrencias tras dos años de seguimiento. Discusión: MOC es una enfermedad infrecuente, donde el manejo médico-quirúrgico combinado es de suma importancia al momento de tratar esta patología y prevenir recurrencias...

Cáncer pulmonar: prevención y pesquisa precoz / Lung cancer: screening and prevention

El cáncer pulmonar es el más mortal de todos los cánceres. Debido a que la gran mayoría de los cánceres pulmonares son causados por el hábito de fumar, su erradicación es la mejor estrategia de prevención primaria. El diagnóstico del cáncer pulmonar en etapas tempranas mejora significativamente su pronóstico, por lo que ésta es la mejor estrategia de prevención secundaria. Recientemente se ha reportado que un programa de pesquisa de cáncer pulmonar con escáner de tórax (TAC) reduce la mortalidad por cáncer. El objetivo de esta revisión es, en primer lugar, apelar a la evidencia en cuanto al rendimiento de los programas de pesquisa de cáncer pulmonar en poblaciones de alto riesgo, y en segundo lugar, analizar las distintas estrategias que tiene un médico cuando se enfrenta a un paciente a quien se le ha encontrado incidentalmente un nódulo pulmonar.

Lung cancer is a deadly disease. Since this cancer is closely related to tobacco smoke, the best way to avoid this disease is smoking prevention. Unfortunately smoking is a worldwide epidemic and in Chile its prevalence is not decreasing. The second best strategy is an early detection. For the first time there is a report showing that screening with the use of low dose CT reduces mortality from lung cancer. The prognosis is much better in early stages. The purpose of this publication is to review the evidence about screening of lung cancer, and to analyze the different strategies to deal, in the general practice, with a finding of a lung nodule.

Diagnóstico precoz de enfermedades pulmonares por tabaquismo / Early diagnose of smoking lung diseases

El tabaquismo es una epidemia y en Chile la prevalencia no ha disminuido. Entre las causas más importantes de muerte por tabaquismo están el cáncer pulmonar y la enfermedad pulmonar obstructiva crónica (EPOC). La erradicación del tabaquismo es la mejor estrategia de prevención de estas enfermedades. La segunda estrategia es la detección precoz de ellas. Sin embargo la EPOC está sub diagnosticada en todo el mundo. No está claro si la solución es hacer más espirometrías en población de riesgo. Es posible que otros métodos diagnósticos como la tomografía axial computada de tórax (TAC) y la difusión pulmonar, puedan mejorar la capacidad de diagnóstico precoz de esta enfermedad. El cáncer pulmonar es el más mortal de los cánceres. El diagnóstico en etapas tempranas mejora significativamente su pronóstico. Hay varios estudios en curso que evalúan el beneficio de hacer pesquisa de cáncer pulmonar con TAC

Cigarette smoking is worldwide epidemic and in Chile its prevalence is not decreasing. Lung cancer and COPD are important causes of smoking related mortality. Primary prevention of smoking is the best way to avoid these diseases. The second best strategy is an early detection of them. However COPD is under diagnosed all over the world and it is not clear if the solution is doing spirometry in risk population. CT scan of the chest and DLCO could increase the early diagnose. Lung cancer is a deadly disease. Its prognosis is much better in early stages. Currently there are some studies in progress evaluating the benefit of doing screening for lung cancer with CT of the chest

Main lipophilic extractives in different paper pulp types can be removed using the laccase-mediator system.

Lipophilic extractives in wood and other lignocellulosic materials exert a negative impact in pulp and paper manufacturing causing the so-called pitch problems. In this work, the appropriateness of an enzymatic treatment using the laccase-mediator system for pitch biocontrol is evaluated. With this purpose, three pulp types representative for different raw materials and pulping processes-eucalypt kraft pulping, spruce thermomechanical pulping, and flax soda-anthraquinone pulping-were treated with a high-redox-potential laccase from the basidiomycete Pycnoporus cinnabarinus in the presence of 1-hydroxybenzotriazole as a redox mediator. The gas chromatography and gas chromatography/mass spectrometry analyses of the lipophilic extractives from the enzymatically treated pulps revealed that the laccase-mediator treatment completely or greatly removed most of the pitch-causing lipophilic compounds present in the different pulps including: (1) free and conjugated sitosterol in eucalypt paper pulp; (2) resin acids, sterol esters, and triglycerides in spruce pulp; and (3) sterols and fatty alcohols in the flax pulp. Different amounts of free and conjugated 7-oxosterols were found as intermediate products in the oxidation of pulp sterols. Therefore, the laccase-mediator treatment is reported as an efficient method for removing pitch-causing lipophilic compounds from paper pulps obtained from hardwood, softwood, and nonwoody plants.

Factores de riesgo en niños con parálisis cerebral infantil en el Centro de Rehabilitación Infantil Teletón, Estado de México / Risk factors in children with infantile cerebral palsy in the Infantile Rehabilitation Center Teleton, Mexico

Introducción. Durante el período madurativo del sistema nervioso central pueden ocurrir riesgos que provoquen lesión cerebral en el período intrauterino, en el momento de nacer o después. Objetivo. Conocer los factores de riesgo en pacientes con diagnóstico de parálisis cerebral infantil del Centro de Rehabilitación Infantil Teletón, Estado de México y su frecuencia. Material y métodos. Estudio observacional, retrospectivo. Se revisaron historias clínicas de pacientes de ambos sexos buscando factores de riesgo. Los resultados se analizaron con pruebas estadísticas de tasa, razón y proporción. Resultados. De 1.112 historias clínicas de pacientes con daño neurológico, 773 tuvieron parálisis cerebral, 653 pacientes con factores de riesgo prenatales y natales, y sólo 120 con factores de riesgo posnatal. El factor de riesgo más frecuente en la etapa prenatal fue la ruptura prematura de membranas, en la etapa natal el período expulsivo prolongado y en la etapa posnatal la neuroinfección. El 42,83 % de los niños pertenecía a la primera gestación. Conclusión. La mayoría de los pacientes fueron varones, los riesgos se presentaron en el tercer trimestre del embarazo y en el momento del parto, la edad de los padres influyó poco en el diagnóstico y la puntuación de Apgar no fue parámetro para el daño

Introduction. During the central nervous system maturation period, there may be risks that cause brain lesion in the intrauterine period, at birth or afterwards. Objective. Know the risk factors in children with cerebral palsy in the Rehabilitation Center Teleton, Mexico and its frequency. Material and methods. This is an observational, retrospective study. The clinical histories of the patients of both genders were reviewed, seeking risk factors. The results were analyzed with statistical tests of rates, odds ratio and proportion. Outcomes. A total of 773 out of 1112 patients with brain damage had cerebral palsy: 653 with prenatal and natal risks factors and only 120 with postnatal risk factors. The most frequent prenatal risk factor was premature rupture of the membrane, prolonged labor period at birth and neuroinfection in the postnatal period. A total of 42.83 % of the children belonged to the first pregnancy. Conclusion. Most of the patients were male, the risk occurred in the last quarter of the pregnancy and at birth. The parents' age had little influence on the diagnosis and Apgar score was not a parameter for damage

Infarto renal: caso clínico / Renal infarction: clinical case

El infarto renal es una patología de infrecuente diagnóstico en nuestro medio, el cuadro clínico puede confundirse fácilmente con un cólico renal o una pielonefritis aguda, por tanto debe tenerse en mente al momento de evaluar un paciente que potencialmente lo presente. A continuacion se describe un caso de infarto renal que fue evaluado en nuestro centro y se realiza una breve discusión en relacion con el diagnóstico y tratamiento de esta entidad.

Attitudes toward physician-nurse collaboration: a cross-cultural study of male and female physicians and nurses in the United States and Mexico.

BACKGROUND: Inter-professional collaboration between physicians and nurses, within and between cultures, can help contain cost and insure better patient outcomes. Attitude toward such collaboration is a function of the roles prescribed in the culture that guide professional behavior. OBJECTIVES: The purpose of the study was to test three research hypotheses concerning attitudes toward physician-nurse collaboration across genders, disciplines, and cultures. METHOD: The Jefferson Scale of Attitudes Toward Physician-Nurse Collaboration was administered to 639 physicians and nurses in the United States (n = 267) and Mexico (n = 372). Attitude scores were compared by gender (men, women), discipline (physicians, nurses), and culture (United States, Mexico) by using a three-way factorial analysis of variance design. RESULTS: Findings confirmed the first research hypothesis by demonstrating that both physicians and nurses in the United States would express more positive attitudes toward physician-nurse collaboration than their counterparts in Mexico. The second research hypothesis, positing that nurses as compared to physicians in both countries would express more positive attitudes toward physician-nurse collaboration, was also supported. The third research hypothesis that female physicians would express more positive attitudes toward physician-nurse collaboration than their male counterparts was not confirmed. CONCLUSIONS: Collaborative education for medical and nursing students, particularly in cultures with a hierarchical model of inter-professional relationship, is needed to promote positive attitudes toward complementary roles of physicians and nurses. Faculty preparation for collaboration is necessary in such cultures before implementing collaborative education.

Repeatability and relationship with field mating performance of a serving capacity pen test in rams.

Two studies were conducted to analyse the repeatability of a serving capacity (SC) pen test and to evaluate the correlation of the results of such a test with field performance. The Laborde SC test, which measures SC by exposing an individual ram for 40min to two restrained non-oestrous ewes in a pen was used. In the first study, SC was measured on four and six occasions during the autumn of 1994 and 1995, respectively. The results indicated that this test is reliable in measuring SC of rams, since SC was repeatable within, and between, breeding season of consecutive years (p<0.05). In the second study conducted on two commercial farms, two groups of ewes synchronised with intravaginal sponges containing medroxyprogesterone acetate, were served by rams of high or low SC. On both the farms, the group of ewes served by rams of high SC had higher pregnancy rates than those served by low SC rams (p<0.05). The Laborde test proved to be a reliable test for the evaluation of SC in rams and that high SC rams had better field performance.

[Cost-benefit of the pharmacologic treatment of cerebral palsy with spasticity in Mexico]. / Coste-beneficio del tratamiento farmacológico de la parálisis cerebral con espasticidad en México.

BACKGROUND: Cerebral palsy involving spasticity is a highly handicapping illness, especially among children, the treatment of which is limited to reducing the handicaps involved without any full cure. There is a drug treatment which affords the possibility of providing patients with a better quality of life, regarding which a cost effectiveness analysis is made, note being made of the individual achievements and social benefits. METHODS: This analysis is based on nationwide information from Mexico which was obtained from secondary sources. The base data is set out within the framework of trends in the growth of this health problem, and the calculations affording the possibility of sizing up this problem are employed in order to ascertain the benefits thereof based on the following indicators: relative impact of this disease and years of healthy life lost and gained, based on which the social and economic benefit entailed in the drug treatment under analysis is estimated. RESULTS: The data reveals that the drug treatment in question is directly beneficial, because it lowers the relative impact of this disease from 0.92 to 0.40. At the individual level, the greatest benefit takes the form of the improved quality of life among the afflicted children within the 6-12 age range, they having gone from 0.08 years to 0.60 years of life in terms of quality. At the nationwide level, the 595,817 years of healthy life which would be lost without any treatment would be recouped. The monetary value involved in this treatment is that of 2,725.00 Mexican pesos (US $283.00) for administering the drug over a one-year period to each child suffering from this disability. CONCLUSIONS: This is a low-cost treatment, because it is currently impossible to reverse the neurological and physiological processes of cerebral palsy, this treatment therefore improving the quality of life of the children afflicted with this disease is the best possible benefit. The cost effectiveness analysis taking into account these indicators reveals a clear-cut relationship between the monetary values and the health benefits.

Perceptions of medical school seniors of the current changes in the U.S. health care system.

Perceptions of medical school seniors about changes occurring in the health care environment were investigated. A survey was completed by 196 Jefferson Medical College seniors in the class of 1997. Of the respondents, 79% believed that cost reduction rather than quality of care is the primary consideration behind recent changes, 78% felt that managed care organizations hamper physicians' abilities to render optimal care, 83% maintained that the control of health care by insurance companies would lead to lower quality of care, 69% agreed that patients should have the freedom to seek a specialist's care without being referred by a primary care physician, 82% recommended that mentally ill patients should be referred to a mental health professional, and 82% believed that learning to work in a managed care environment should be an essential component of medical education. Assessment of student perceptions can assist in the development and implementation of appropriate curricular changes.

[Clinical competence of physical medicine and rehabilitation residents]. / Evaluación de la aptitud clínica de médicos residentes de medicina física y rehabilitación.

OBJECTIVE: To explore if the year of training in the specialty of physical medicine and rehabilitation (PMR) increases the clinical aptitudes of trainees in this area. METHODS: All the PMR trainees in two units of PMR of the Mexican Social Security Institute in Mexico City were evaluated (17 in their 1st year, 22 in their 2nd and 8 in their 3rd year of training). Their clinical aptitude was measured using a questionnaire of 296 items which explored 10 areas of knowledge. Non parametric statistics were used to evaluate the differences between scores by year of training. RESULTS: There were no significant differences between years of training in the areas specifically pertinent to the PMR specialty. The only difference was a higher rate of iatrogenic commission in the 1st year residents as compared with those in their 3rd year suggesting a better use of diagnostic and therapeutic resources of the latter. There was a poor performance in nearly all residents as 45 of the 47 scored in the low or very low range of knowledge. CONCLUSIONS: The clinical aptitude of the PMR residents was poor in general. Our findings should be taken as a starting point to seek strategies to improve the training in the PMR specialty.

Superovulatory response in anestrous ewes is affected by the presence of a large follicle.

Superovulatory response to conventional treatment with eCG (1200 IU) and progestagen sponges (MAP, n = 9; FGA, n = 9; or controls without sponge, n = 6) was studied in Corriedale anestrous ewes. The follicular population just before the administration of eCG and the total ovarian response (large anovulatory follicles plus normal CL and prematurely regressing CL) to treatment were determined after laparotomy. Pretreatment with progestagen did not modify the number or class of follicles greater than 1 mm observed on the ovarian surface at the time of eCG administration (19 +/- 2.2 follicles vs 19 +/- 2.9 follicles, for pooled progestagen-treated groups and control groups, respectively; mean +/- SEM) but significantly decreased the number of large anovulatory follicles (4.7 +/- 1.0 vs 10.2 +/- 2.6; P < or = 0.01) observed following treatment. Progestagen-treated animals were classified according to the presence (n = 13) or absence (n = 5) of a large follicle (LF: > or = 4 mm diameter) on the ovarian surface at the time of eCG treatment; a qualitatively better superovulatory response was observed in ewes without large follicle (large anovulatory follicles: 1.6 +/- 0.7 vs 5.8 +/- 1.3, P < or = 0.05; normal CL: 7.0 +/- 1.4 vs 3.8 +/- 1.0, P < or = 0.1; normal CL/total ovarian response: 78.7 +/- 10.1 % vs 34.9 +/- 8.2 %, P < or = 0.01; for ewes without LF and ewes with 1 to 2 LF respectively). No differences were observed in the individual ovulatory response when comparing ovaries ipsilateral or contralateral to LF in a same animal, indicating that the effect of LF on the superovulatory response would be fundamentally systemic. This work shows that, similar to what occurs in cows, the presence of a large follicle at the time of gonadotropin administration decreases the superovulatory response in anestrous ewes.