Irreducible and periodic positive maps

We extend the notions of irreducibility and periodicity of a stochastic matrix to a unital positive linear map $\Phi$ on a finite-dimensional C*-algebra A and discuss the non-commutative version of the Perron-Frobenius theorem. As an example, positive linear maps on $M_2(C)$ are analyzed

Lesiones en el manguito rotador tras luxación anterior de hombro en pacientes mayores de 40 años.

Se ha realizado un estudio prospectivo de la evolución de 32 luxaciones anteriores de hombro en pacientes de más de 40 años con el objetivo de establecer la incidencia, localización y tipo de rotura del manguito rotador a causa de la luxación, conocer evolución clínica y establecer los criterios clínicos que nos permitan sospechar una rotura del manguito rotador, sin necesidad de recurrir a resonancia magnética (RM) de entrada. Los pacientes fueron sometidos a estudio mediante RM, clasificando las lesiones observadas en cinco grados en función de la extensión de la rotura, siendo el grupo 1 la integridad del manguito. El 90% de los casos presentó una rotura del manguito rotador asociada a la luxación. Tras un periodo de rehabilitación se demostró una diferencia significativa en la recuperación de la abducción en los pacientes con manguito íntegro, siendo un signo clínico de importancia para valorar el estado del manguito rotador.A prospective study of the evolution of 32 anterior dislocations of the shoulder in patients older than forty years has been done with the objective of establishing the incidence, location and kind of tear caused by the dislocation, to know the evolution and to establish the clinical parameters that allow us to suspect an injury of the rotator cuff without the help of magnetic resonance (MR) in the beginning. All the patients were studied with MR, doing a classification of the tears in five degrees, depending on the extension of the tears, being the group 1 the integrity of the rotator cuff. In 90% of the cases a rotator cuff tear has been found to be associated with the dislocation. After the rehabilitation, a significative difference in the recovery of the abduction has been demonstrated in the patients with integrity of the rotator cuff, being an important clinical sign to know the state of the rotator cuff

Modelo artificial de sutura quirúrgica Morales Meseguer. Resultados preliminares

[[SPA] Durante la realización de las prácticas de cirugía, nuestros alumnos deben de familiarizarse con la ejecución de suturas quirúrgicas. Una oportunidad de realizar el entrenamiento previo a la sutura de un paciente es este modelo artificial, en el que aúna su parecido estructural con la piel humana, el bajo coste del modelo artificial propuesto, el ser un modelo fácilmente reproducible y la gran utilidad que le supone al estudiante de medicina para el aprendizaje de la realización de una correcta sutura quirúrgica. Los resultados preliminares se derivan de una muestra de 28 estudiantes que realizaron una encuesta anónima online tipo Likert con los siguientes ítems: sencillez del modelo, comodidad, aprendizaje y seguridad proporcionada ante la realización de una sutura en un paciente real. [ENG] While performing surgery practices, our students should be familiar with the performance of surgical sutures. An opportunity for training prior to suture a patient is this artificial model, which combines its structural resemblance to human skin, the low cost of the proposed artificial model, being an easily reproducible and useful model to supposed to medical student learning of performing proper surgical suture. Preliminary results are derived from a sample of 28 students who completed an anonymous online survey with Likert type the following items: model simplicity, convenience, and safety training provided to the embodiment of a suture on a real patien

Neuropathic post-COVID pain symptomatology is not associated with serological biomarkers at hospital admission and hospitalization treatment in COVID-19 survivors

OBJECTIVE: Evidence suggests that individuals who had survived to coronavirus disease, 2019 (COVID-19) could develop neuropathic post-COVID pain. This study investigated the association of serological biomarkers and treatments received during hospitalization with development of neuropathic-associated symptoms.METHODS: One hundred and eighty-three (n = 183) previously hospitalized COVID-19 survivors during the first wave of the pandemic were assessed in a face-to-face interview 9.4 months after hospitalization. Nineteen serological biomarkers, hospitalization data, and treatment during hospitalization were obtained from medical records. Neuropathic pain symptoms (Self-Report Leeds Assessment of Neuropathic Scale), sleep quality (Pittsburgh Sleep Quality Index), pain catastrophizing (Pain Catastrophizing Scale) and anxiety/depressive levels (Hospital Anxiety and Depression Scale) were assessed.RESULTS: The prevalence of post-COVID pain was 40.9% (n = 75). Fifteen (20%) patients reported neuropathic symptoms. Overall, no differences in hospitalization data and serological biomarkers were identified according to the presence or not of neuropathic-associated symptoms. Patients with post-COVID pain had the highest neutrophil count, and post hoc analysis revealed that patients with neuropathic post-COVID associated symptoms had lower neutrophil count (p = 0.04) compared with those without neuropathic pain, but differences were small and possible not clinically relevant. No differences in fatigue, dyspnea, brain fog, anxiety or depressive levels, poor sleep, or pain catastrophism between patients with and without neuropathic symptoms were found.CONCLUSION: It seems that neuropathic-like post-COVID pain symptoms are not associated with neither of assessed serological biomarkers at hospital admission nor hospitalization treatments received in this cohort of hospitalized COVID-19 survivors.</p

Una experiencia de integración de la Formación Sanitaria Especializada con la Universitaria de Posgrado: Entrenamiento por etapas en cirugía laparoscópica.

Background: Design of a simulation model training in laparoscopic surgery for surgical residents. Methods: Three stages of progressive training were programmed within a Postgraduate Degree in Clinical Anatomy. Stage 1 was performed in a box-trainer with synthetic materials: managing small objects, dissection with clamp and scissors, and laparoscopic intracorporeal suture. Stage 2 used biological material (fresh digestive tract from a human corpse) in box-trainer, practicing section and intracorporeal anastomosis. In stage 3, laparoscopy was performed on a fresh corpse (appendectomy, cholecystectomy, lesser sac opening, right and left colectomy). A satisfaction survey was carried out to the participants. Results: Some six General and Digestive Surgery residents took the program. All of them completed the stage 1 and 2 exercises. In stage 3, the pneumoperitoneum could be performed without any complications, and tissues presented an adequate texture. First-year residents completed appendectomy and cholecystectomy, but more complex procedures required more experienced residents. The participants reflected that the program is adequate and useful to gain basic skills in laparoscopy. Conclusions: The proposed model is reproducible and adequate in acquisition of basic skills in laparoscopic surgery.Antecedentes: Diseño de un modelo de simulación para formación en cirugía laparoscópica. Métodos: Dentro del Máster Anatomía Aplicada a la Clínica se implementaron tres etapas de formación progresiva en médicos residentes. La etapa 1 se realizó en simulador con material no biológico: manejo de objetos, disección con pinza y tijera, y sutura laparoscópica. La etapa 2 utilizó material biológico (tubo digestivo en fresco) en simulador, para la práctica de sección intestinal y anastomosis intracorpórea. En la etapa 3 se realizaron técnicas laparoscópicas en cadáver en fresco (apendicectomía, colecistectomía, apertura de la transcavidad epiploica, hemicolectomías derecha e izquierda). Se añadió una encuesta de satisfacción a los participantes de la actividad. Resultados: El programa se impartió a 6 residentes de Cirugía General. Todos completaron los ejercicios de las etapas 1 y 2. En la etapa 3 se pudo realizar el neumoperitoneo sin dificultad y los tejidos presentaron una textura adecuada. Los residentes de primer año completaron la apendicectomía y la colecistectomía, pero procedimientos más complejos requirieron residentes con más experiencia. Los participantes encuestados reflejaron que el programa es adecuado y útil para el entrenamiento en laparoscopia. Conclusiones: El modelo propuesto es reproducible y adecuado en adquisición de competencias básicas en cirugía laparoscópica

Macro and micromechanics analysis of short fiber composites stiffness: The case of old newspaper fibers-polypropylene composites

Stiffness is one of the most relevant characteristics of composite materials. Natural wood fibers have demonstrated their ability to increase the Young's moduli of composite materials, and old newspapers are a potential source of reinforcing fibers for composite materials. There are some micromechanic models to predict the Young's modulus of composite materials, and one of the input data is the intrinsic modulus of their fibers. This intrinsic modulus is a value which is difficult or impossible to measure in the case of wood fibers, due to their measures. This paper evaluates the stiffening abilities of old newspaper fibers and the possibility to back calculate the value of the intrinsic Young's Modulus by means of micromechanic models. Different percentages of old newspaper fibers were compounded with polypropylene (PP). Micromechanics of the fibers were obtained using Hirsch model, Cox-Krenchel's model, Tsai-Pagano model and Halpin-Tsai equations. The most important results were the average intrinsic Young's modulus of the fibers, the mean orientation angle and the mean modulus efficiency factor.Serrano, A.; Espinach, FX.; Tresserras, J.; Rey Tormos, RMD.; Pellicer, N.; Mutje Pujol, P. (2014). Macro and micromechanics analysis of short fiber composites stiffness: The case of old newspaper fibers-polypropylene composites. Materials and Design. 55:319-324. doi:10.1016/j.matdes.2013.10.011S3193245

Removing of Direct Red 83:1 using α- and HP-α-CDs polymerized with epichlorohydrin: Kinetic and equilibrium studies

The adsorption properties of two cyclodextrin-epichlorohydrin polymers to remove Direct Red 83:1 textile dye from wastewater solutions was evaluated. Adsorption studies were performed in a batch reactor, and the efficiency of the polymers under different parametric values such as contact time, adsorbent dosage, initial dye concentration, pH of initial solution and temperature was followed by spectrophotometry. Both Langmuir and Freundlich equations were used to fit the equilibrium isotherms and the kinetic data were analyzed by the pseudo-first-order and pseudo-second-order models. Adsorption process follows a pseudo-second-order kinetic and was influenced by intraparticle diffusion model, dye concentration and contact time, reaching equilibrium within the first 30 min. Experimental data were better fitted to Freundlich isotherm model than to Langmuir and Temkin isotherms. Since about 93% of dye removal was achieved under optimized conditions, the α-cyclodextrin-epichlorohydrin polymer seems to be a useful device for removing Direct Red 83:1 from aqueous solutions and industrial effluents.Ciencias Ambientale

Neuropathic post-COVID pain symptomatology is not associated with serological biomarkers at hospital admission and hospitalization treatment in COVID-19 survivors

ObjectiveEvidence suggests that individuals who had survived to coronavirus disease, 2019 (COVID-19) could develop neuropathic post-COVID pain. This study investigated the association of serological biomarkers and treatments received during hospitalization with development of neuropathic-associated symptoms.MethodsOne hundred and eighty-three (n = 183) previously hospitalized COVID-19 survivors during the first wave of the pandemic were assessed in a face-to-face interview 9.4 months after hospitalization. Nineteen serological biomarkers, hospitalization data, and treatment during hospitalization were obtained from medical records. Neuropathic pain symptoms (Self-Report Leeds Assessment of Neuropathic Scale), sleep quality (Pittsburgh Sleep Quality Index), pain catastrophizing (Pain Catastrophizing Scale) and anxiety/depressive levels (Hospital Anxiety and Depression Scale) were assessed.ResultsThe prevalence of post-COVID pain was 40.9% (n = 75). Fifteen (20%) patients reported neuropathic symptoms. Overall, no differences in hospitalization data and serological biomarkers were identified according to the presence or not of neuropathic-associated symptoms. Patients with post-COVID pain had the highest neutrophil count, and post hoc analysis revealed that patients with neuropathic post-COVID associated symptoms had lower neutrophil count (p = 0.04) compared with those without neuropathic pain, but differences were small and possible not clinically relevant. No differences in fatigue, dyspnea, brain fog, anxiety or depressive levels, poor sleep, or pain catastrophism between patients with and without neuropathic symptoms were found.ConclusionIt seems that neuropathic-like post-COVID pain symptoms are not associated with neither of assessed serological biomarkers at hospital admission nor hospitalization treatments received in this cohort of hospitalized COVID-19 survivors

Adsorption Properties of β- and Hydroxypropyl-β-Cyclodextrins Cross-Linked with Epichlorohydrin in Aqueous Solution. A Sustainable Recycling Strategy in Textile Dyeing Process

β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) were used to prepare insoluble polymers using epichlorohydrin as a cross-linking agent and the azo dye Direct Red 83:1 was used as target adsorbate. The preliminary study related to adsorbent dosage, pH, agitation or dye concentration allowed us to select the best conditions to carry out the rest of experiments. The kinetics was evaluated by Elovich, pseudo first order, pseudo second order, and intra-particle diffusion models. The results indicated that the pseudo second order model presented the best fit to the experimental data, indicating that chemisorption is controlling the process. The results were also evaluated by Freundlich, Langmuir and Temkin isotherms. According to the determination coefficient (R2), Freunlich gave the best results, which indicates that the adsorption process is happening on heterogeneous surfaces. One interesting parameter obtained from Langmuir isotherm is qmax (maximum adsorption capacity). This value was six times higher when a β-CDs-EPI polymer was employed. The cross-linked polymers were fully characterized by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA). Also, morphology and particle size distribution were both assessed. Under optimized conditions, the β-CDs-EPI polymer seems to be a useful device for removing Direct Red 83:1 (close 90%), from aqueous solutions and industrial effluents. Complementarily, non-adsorbed dye was photolyzed by a pulsed light driven advanced oxidation process. The proposed methodology is environmental and economically advantageous, considering the point of view of a sustainable recycling economy in the textile dyeing process.Ciencias Ambientale