Fractional RC and LC Electrical Circuits

AbstractIn this paper we propose a fractional differential equation for the electrical RC and LC circuit in terms of the fractional time derivatives of the Caputo type. The order of the derivative being considered is 0<γ<1. To keep the dimensionality of the physical parameters R, L, C the new parameter a is introduced. This parameter characterizes the existence of fractional structures in the system. A relation between the fractional order time derivative γ and the new parameter σ is found. The numeric Laplace transform method was used for the simulation of the equations results. The results show that the fractional differential equations generalize the behavior of the charge, voltage and current depending of the values of γ. The classical cases are recovered by taking the limit when γ=1. An analysis in the frequency domain of an RC circuit shows the application and use of fractional order differential equations

Novel non-resorbable polymeric-nanostructured scaffolds for guided bone regeneration

Objective The aim of this study was to evaluate the bone-regeneration efficiency of novel polymeric nanostructured membranes and the effect of zinc, calcium, titanium and bone morpho-protein loading on membranes, through an in vivo rabbit model. Material and Methods Nanostructured membranes of methylmethacrylate were loaded with zinc, calcium, TiO2 nanoparticles and bone-morphogenetic protein (BMP). These membranes covered the bone defects prepared on the skulls of six rabbits. Animals were sacrificed six weeks after surgery. Micro computed tomography was used to evaluate bone architecture through BoneJ pluging and ImageJ script. Three histological processing of samples, including von Kossa silver nitrate, toluidine blue and fluorescence by the deposition of calcein were utilized. Results Zn-Membranes (Zn-Ms) promoted the highest amount of new bone and higher bone perimeter than both unloaded and Ti-Membranes (Ti-Ms). Ca-Membranes (Ca-Ms) attained higher osteoid perimeter and bone perimeter than Zn-Ms. The skeleton analysis showed that Zn-Ms produced more branches and junctions at the trabecular bone than BMP-loaded membranes (BMP-Ms). Samples treated with Ti-Ms showed less bone formation and bony bridging processes. Both Zn-Ms and Ca-Ms achieved higher number of osteoblasts than the control group. BMP-Ms and Ca-Ms originated higher number of blood vessels than Ti-Ms and control group. Conclusions Zn incorporation in novel nanostructured membranes provided the highest regenerative efficiency for bone healing at the rabbit calvarial defects. Clinical relevance Zn-Ms promoted osteogenesis and enhanced biological activity, as mineralized and osteoid new bone with multiple interconnected ossified trabeculae appeared in close contact with the membrane.Project MAT2017-85999-P MINECO/AEI/FEDER/UE supported by the Ministry of Economy and Competitiveness and European Regional Development Fund

El Zompantli, un evento con historia

El concurso de altares de muertos denominado Zompantli que anualmente se realiza en la Unidad Académica de Turismo ha sido el medio para generar una dinámica de convivencia y participación particular entre los alumnos, docentes y administrativos, además, ha sido un importante medio de proyección hacia la sociedad. Por lo anterior se pretende documentar el origen y evolución de dicha actividad para, posteriormente, realizar un análisis y determinar el impacto que ésta ha tenido en la conformación de una identidad institucional

Re- operation for sepsis in abdominal surgery. 2010-2012

Introducción: la reintervención quirúrgica abdominal es frecuente en nuestros días, suele derivarse de un primer procedimiento quirúrgico no satisfactorioo por complicaciones post quirúrgicas derivadas de factores intrínsecos y/o extrínsecos.Objetivo: evaluar los criterios de mayor valor para decidir la reintervención de un paciente con cirugía abdominal.Método: se realizó un estudio de cohortes retrospectiva en todos los pacientes reintervenidos con cirugía abdominal del servicio de Cirugía General del Hospital Provincial “Carlos Manuel de Céspedes”, en el periodo comprendido desde enero de 2010 y diciembre de 2012. Resultados: el análisis bivariado destaca la influencia de la frecuencia respiratoria, la temperatura, elementos de abdomen agudo quirúrgico, presión intrabdominal, leucocitosis, ecografía y la tomografía abdominal sobre la reintervención por sepsis.Conclusiones: el sexo masculino, el aumento de la frecuencia respiratoria, una PIA elevada, la temperatura mayor de 370 y la presencia de elementos de abdomen agudo quirúrgico fueron variables significativas en el estudio, sin embargo sólo las dos últimas se comportaron como variables predictivas de la reintervención por sepsis intrabdominal. Introduction: the abdominal surgical re operation is frequent nowadays, it is usually derived from a first unsatisfactory surgical procedure or due to post surgical complications derived from intrinsic and/or extrinsic or intrinsic factors.Objective:  to evaluate the criteria of greatest values in order to decide the re operation of a patient with abdominal surgery.Method: it was performed a retrospective cohort study in all patients with abdominal surgery in the General Surgery Service at Carlos Manuel de Céspedes Province Hospital in the period between January 2010 and December 2012.Results: the bivariate analysis emphasizes the influence of the respiratory rate, the temperature, elements of the acute surgical abdomen, intra- abdominal pressure, leukocytosis, echography and abdominal tomography on re operation for sepsis.Conclusions: the male sex, the increase of the respiratory rate, high PIA, the temperature over 370 and the presence of elements of acute surgical abdomen were the significant variables in the study. However, only the last two behaved like predictive variables of the re operation for intra- abdominal sepsis

El trabajo remoto y el desempeño laboral en el marco del covid-19

Telecommuting allows employees to do work from home. In a COVID-19 pandemic context, telecommuting has become the main working mode in organizations. This fact represents a challenge for maintaining employee&nbsp;productivity, due to labor pressures and market uncertainty. Two main factors emerge from this analysis: the organization´s capacity to establish adequate communication systems, and the ability of the employee to manage his or her emotions under uncertainty.El teletrabajo busca que los trabajadores puedan realizar sus labores de forma remota. En un contexto de pandemia&nbsp;por la COVID-19, el teletrabajo se ha convertido en la principal modalidad para desarrollar las labores en las organizaciones; y esto representa un desafío para mantener la productividad de los trabajadores, debido a las presiones laborales y la incertidumbre en el mercado del trabajo. Dos factores importantes emergen en este análisis: la habilidad de las organizaciones en establecer sistemas de comunicación adecuados y la capacidad del trabajador de manejar sus emociones en entornos inciertos

Banks of Cryopreserved Skin from Live Donors and Total Skin Allografts in the Surgery of Major Burnt Patients

Scarectomy and prompt coverage are some of the main cornerstones of the actual treatment of major burnt patients. This coverage can be definitive using autologous tissues or temporary with allografts, xenografts, and/or biosynthetic products. Skin allografts (SAs) are the gold standard therapeutic alternative among temporary coverages, since they mimic skin functions. However, cadaveric skin donation and procurement, a common SA source, are infrequent. On the other hand, there is a significant number of patients that, given their health condition, large amounts of skin must be resected for their clinical recovery, including patients submitted to corporal contouring surgeries with esthetic and/or reconstructive motives, usually eliminating the redundant skin as biological waste. This study describes a skin bank model from live donors and cryopreserved total skin cutaneous allografts (CTSCAs), a new type of SA resulting from a particular skin processing

La vid silvestre en México. Actualidades y potencial

En ocho capítulos se aborda el estado del arte de la vid silvestre en MéxicoEl estudio de las especies vegetales nativas de México representa un reto que cada día más investigadores mexicanos asumen. Durante muchos años, el apoyo a la investigación pública ha sido mínimo; desde el punto de vista agronómico es insuficiente para avanzar a la velocidad que requiere nuestro país para afrontar problemas de producción y distribución de alimentos. Por esa razón, entre otras, me es grato presentar esta obra que compila parte de los trabajos de la Red de Vid Silvestre patrocinada por el Sistema Nacional de Recursos Fitogenéticos (sinarefi) dependiente de la sagarpa; trabajos apuntalados por investigadores que sin pertenecer a la red han colaborado en el estudio de las plantas del género Vitis. En este libro se muestra el potencial del país para aprovechar el recurso vid, empleado desde antes de la conquista española por nativos mexicanos que conocían sus bondades. Es necesario continuar el avance en el conocimiento de este recurso, por ello el presente libro pretende invitar a toda persona interesada en contribuir con el rescate y conservación de las vides mexicanas. Los autores y editores, así como las instituciones en donde laboramos y aquellas que patrocinan estas investigaciones, esperamos se cumpla este objetivo y que el lector, alumno, profesor, investigador, público en general, disfrute esta lectura y, sobre todo, se interese en el recurso VitisSEP, SINAREFI, UAEME

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality