Problemario de planeación y control de la producción

236 páginasEl propósito de este libro es complementar el curso de Planeación y Control de la Producción y facilitar el aprendizaje por medio de una serie de problemas que ilustran las situaciones típicas de este tipo de actividades. No pretende ser una recopilación exhaustiva de todos los problemas existentes en la materia, sino una muestra representativa de las diferentes posibilidades de problemas que se pueden presentar en la vidad profesional, con varios grados de dificultad. En cada sección de los problemas resueltos, se ilustra y explica en detalle la forma o formas (cuando existe más de una) en que se puede llegar a una solución adecuada. Es importante señalar que se incluyen problemas más complejos de los que generalmente se encuentran resueltos en los textos sobre la materia. Se incluye una serie de problemas propuestos para los cuales se provee la solución final

Estocástica: finanzas y riesgo. Volumen 6, número 1 (enero-junio, 2016)-

1 archivo PDF (114 páginas). EFR61"En este número presentamos dos metodologías, con distintas aplicaciones y variantes, que son ampliamente usadas en el sistema financiero. Por un lado, la métrica del Valor en Riesgo, VaR, que desde la última década del siglo pasado empezó a usarse de manera generalizada para cuantificar el riesgo, y cuya importancia ha crecido al ser adoptada como indicador de éste por los reguladores a nivel internacional. Por otra parte, se encuentra la teoría de cópulas, la cual tiene como una de sus principales aplicaciones en las finanzas, la medición de la dependencia entre distintas variables, debido a que, dada una distribución multivariada arbitraria, ésta puede descomponerse en sus marginales y en su estructura de dependencia. A principios de este siglo, el concepto de cópula se utilizó en los modelos VaR con distribuciones gaussianas y t-student para modelar dependencias sectoriales. Y a partir de entonces, tanto los modelos VaR como la teoría de cópulas, con sus distintas variantes, han sido utilizadas extensivamente.

Ocrelizumab not recommended in France for patients with primary progressive multiple sclerosis while recommended in England : a review comparing the assessment by HAS and NICE

Peer reviewedPostprin

A new self-expanding aortic stent valve with annular fixation: in vitro haemodynamic assessment

Objective: Balloon-expandable stent valves require flow reduction during implantation (rapid pacing). The present study was designed to compare a self-expanding stent valve with annular fixation versus a balloon-expandable stent valve. Methods: Implantation of a new self-expanding stent valve with annular fixation (Symetis®, Lausanne, Switzerland) was assessed versus balloon-expandable stent valve, in a modified Dynatek Dalta® pulse duplicator (sealed port access to the ventricle for transapical route simulation), interfaced with a computer for digital readout, carrying a 25 mm porcine aortic valve. The cardiovascular simulator was programmed to mimic an elderly woman with aortic stenosis: 120/85 mmHg aortic pressure, 60 strokes/min (66.5 ml), 35% systole (2.8 l/min). Results: A total of 450 cardiac cycles was analysed. Stepwise expansion of the self-expanding stent valve with annular fixation (balloon-expandable stent valve) resulted in systolic ventricular increase from 120 to 121 mmHg (126 to 830 ± 76 mmHg)*, and left ventricular outflow obstruction with mean transvalvular gradient of 11 ± 1.5 mmHg (366 ± 202 mmHg)*, systolic aortic pressure dropped distal to the valve from 121 to 64.5 ± 2 mmHg (123 to 55 ± 30 mmHg) N.S., and output collapsed to 1.9 ± 0.06 l/min (0.71 ± 0.37 l/min* (before complete obstruction)). No valve migration occurred in either group. (* = p < 0.05). Conclusions: Implantation of this new self-expanding stent valve with annular fixation has little impact on haemodynamics and has the potential for working heart implantation in vivo. Flow reduction (rapid pacing) is not necessar

Congenital native interruption of aortic arch in an adult: Extra-anatomic approach by right-side thoracotomy

We outline the case of an 18-year-old male patient with a congenital nonoperated interruption of the aortic arch. A right thoracotomy without cardiopulmonary bypass facilitated repair through an extra-anatomic bypass between the ascending and the supradiaphragmatic descending aorta. Results for the immediate and 2-year radiologic and clinical check-up were satisfactory. The most common complications in anatomic correction are stroke under selective cerebral perfusion, risk of paraplegia, and hemorrhage. We present a new technique for repair of interruption of the aortic arch in adults that avoids the need for extended dissection of the aorta and a partial occlusion clamp during anastomosis and allows for cerebral and medullar perfusion

Catheter ablation of atrial tachyarrhythmias in patients with atrioventricular septal defect

AIMS: The incidence of atrial tachyarrhythmias is high in patients with atrioventricular septal defect (AVSD). No specific data on catheter ablation have been reported so far in this population. We aimed to describe the main mechanisms of atrial tachyarrhythmias in patients with AVSD and to analyse outcomes after catheter ablation. METHODS AND RESULTS: This observational multi-centric cohort study enrolled all patients with AVSD referred for catheter ablation of an atrial tachyarrhythmia at six tertiary centres from 2004 to 2022. The mechanisms of the different tachyarrhythmias targeted were described and outcomes were analysed. Overall, 56 patients (38.1 ± 17.4 years, 55.4% females) were included. A total of 87 atrial tachyarrhythmias were targeted (mean number of 1.6 per patient). Regarding main circuits involved, a cavo-annular isthmus-dependent intra-atrial re-entrant tachycardia (IART) was observed in 41 (73.2%) patients and an IART involving the right lateral atriotomy in 10 (17.9%) patients. Other tachyarrhythmias with heterogeneous circuits were observed in 13 (23.2%) patients including 11 left-sided and 4 right-sided tachyarrhythmias. Overall, an acute success was achieved in 54 (96.4%) patients, and no complication was reported. During a mean follow-up of 2.8 ± 3.8 years, 22 (39.3%) patients had at least one recurrence. Freedom from atrial tachyarrhythmia recurrences was 77.5% at 1 year. Among 15 (26.8%) patients who underwent repeated ablation procedures, heterogeneous circuits including bi-atrial and left-sided tachyarrhythmias were more frequent. CONCLUSION: In patients with AVSD, most circuits involve the cavo-annular isthmus, but complex mechanisms are frequently encountered in patients with repeated procedures. The acute success rate is excellent, although recurrences remain common during follow-up.</p

The Fontan circulation in univentricular congenital heart disease treatment : Clinical, physiopathological and experimental approach

L’intervention de Fontan est une chirurgie palliative pour les cardiopathies congénitales univentriculaire. A long terme, la défaillance cardiaque, l’hypertension artérielle pulmonaire(HTAP) et l’entéropathie exsudative peuvent mener à l’échec tardif du Fontan.Une mise au point clinique a été realisée en se focalisant secondairement sur les patients adultes.L’intérêt de la cavo bipulmonaire (CBP), étape intermédiaire au Fontan, dans certains cas de retours veineux pulmonaires anormaux totaux a été décrite. Afin d’affiner de futures études cliniques, nous avons discuté de l’intérêt du Brain NatriureticPeptide en post opératoire de Fontan. Nous avons démontré la fiabilité d’une nouvelle technologiede l’oxyme´trie de pouls chez des enfants cyanosés et la non fiabilité d’un nouveau dispositifd’impédancemétrie pour le monitorage non invasif du de´bit cardiaque en comparaison avecun cathéter artériel pulmonaire.Un modèle animal viable et chronique de la CBP a été développé. Il a montré que le flux pulsatileantérograde empêche la formation de fistules artério-veineuses pulmonaires (FAVP), améliorel’hématose et atténue le développement de l’HTAP soutenant cliniquement le maintien de ce fluxlors de la création d’une CBP. Par ailleurs, la perte de pulsatilité, en diminuant le contrainte de cisaillement, entraîne unediminution de l’eNOS synthase et une réponse altérée vaso-relaxante dépendante de l'endothélium artérielle pulmonaire. La micropulsatilité limite ces effets délétères. Ces résultats impliquent desthérapies potentielles contre l’HTAP du Fontan, en maintenant un débit pulmonaire accessoire et la modulation pharmaceutique vaso-relaxante non endothélium-dépendanteThe Fontan surgery is a palliative surgery for univentricular congenital heart disease. On the longterm, heart failure, pulmonary arterial hypertension (PAH) and exudative enteropathy may lead tothe Fontan failure.A clinical adjustment has been realized by focusing secondarily on adult patients. The advantage, insome cases of total anomalous pulmonary venous return, of the bidirectional cavopulmonary (BCP),which is an intermediate stage of Fontan, has been described.In order to prepare future clinical studies, we have discussed about Brain Natriuretic Peptide inpostoperative Fontan surgery. We have demonstrated the reliability of a new technology of pulseoxymetry in cyanotic children and the unreliability of a new device of impedance for non-invasivemonitoring of cardiac outpout in comparison with pulmonary arterial catheter.A viable chronic animal model of bidirectional cavo-pulmonary (BCP) has been developed. Itshowed that the antegrade pulsatile flow prevents the formation of pulmonary arteriovenous fistulas(PAVMs) ,improves hematosis and attenuates the development of PAH clinically supporting themaintenance of this flow when creating a BCP.Moreover, the loss of pulsatility while reducing the shear stress causes a decrease in e-NOSsynthase and a dependent vaso-relaxing altered response of the pulmonary arterial endothelium. Themicropulsatility limits these deleterious effects. These results imply potential therapies against thePAH of Fontan surgery, maintaining an accessory pulmonary blood flow and the pharmaceuticalvaso-relaxing non-endothelium dependent modulation

Validez de Constructo de la Escala de Ira al Manejar en una Muestra Mexicana

Primavera 2012El objetivo de esta investigación fue evaluar en una muestra mexicana la estructura factorial de la Escala de Ira al Manejar de Deffenbacher (1996). Participaron 646 automovilistas universitarios (301 varones y 345 mujeres) con edad promedio de 21.26 (DE= 2.86) quienes contestaron la Escala de Ira al Manejar (Deffenbacher et al., 1996). Esta escala tiene seis factores o escalas de qué situaciones hacen enojar al conducir: (1) Gestos hostiles (por ej. alguien te grita por tu forma de manejar), (2) Conducción ilegal (por ej. alguien se pasa el semáforo en rojo), (3) Presencia de la policía (por ej. un policía te pide que te orilles), (4) Conducción lenta (por ej. alguien se estaciona lentamente, atrasando el tráfico), (5) Descortesía (por ej. alguien acelera cuando tratas de rebasarlo), y (6) Obstrucción de tráfico (por ej. estás atorado en un embotellamiento). Como resultado de análisis factorial confirmatorio, se encontr

La circulation de Fontan dans le traitement des cardiopathies congénitales uni-ventriculaires : Approche clinique, physiopathologique et expérimentale

The Fontan surgery is a palliative surgery for univentricular congenital heart disease. On the longterm, heart failure, pulmonary arterial hypertension (PAH) and exudative enteropathy may lead tothe Fontan failure.A clinical adjustment has been realized by focusing secondarily on adult patients. The advantage, insome cases of total anomalous pulmonary venous return, of the bidirectional cavopulmonary (BCP),which is an intermediate stage of Fontan, has been described.In order to prepare future clinical studies, we have discussed about Brain Natriuretic Peptide inpostoperative Fontan surgery. We have demonstrated the reliability of a new technology of pulseoxymetry in cyanotic children and the unreliability of a new device of impedance for non-invasivemonitoring of cardiac outpout in comparison with pulmonary arterial catheter.A viable chronic animal model of bidirectional cavo-pulmonary (BCP) has been developed. Itshowed that the antegrade pulsatile flow prevents the formation of pulmonary arteriovenous fistulas(PAVMs) ,improves hematosis and attenuates the development of PAH clinically supporting themaintenance of this flow when creating a BCP.Moreover, the loss of pulsatility while reducing the shear stress causes a decrease in e-NOSsynthase and a dependent vaso-relaxing altered response of the pulmonary arterial endothelium. Themicropulsatility limits these deleterious effects. These results imply potential therapies against thePAH of Fontan surgery, maintaining an accessory pulmonary blood flow and the pharmaceuticalvaso-relaxing non-endothelium dependent modulation.L’intervention de Fontan est une chirurgie palliative pour les cardiopathies congénitales univentriculaire. A long terme, la défaillance cardiaque, l’hypertension artérielle pulmonaire(HTAP) et l’entéropathie exsudative peuvent mener à l’échec tardif du Fontan.Une mise au point clinique a été realisée en se focalisant secondairement sur les patients adultes.L’intérêt de la cavo bipulmonaire (CBP), étape intermédiaire au Fontan, dans certains cas de retours veineux pulmonaires anormaux totaux a été décrite. Afin d’affiner de futures études cliniques, nous avons discuté de l’intérêt du Brain NatriureticPeptide en post opératoire de Fontan. Nous avons démontré la fiabilité d’une nouvelle technologiede l’oxyme´trie de pouls chez des enfants cyanosés et la non fiabilité d’un nouveau dispositifd’impédancemétrie pour le monitorage non invasif du de´bit cardiaque en comparaison avecun cathéter artériel pulmonaire.Un modèle animal viable et chronique de la CBP a été développé. Il a montré que le flux pulsatileantérograde empêche la formation de fistules artério-veineuses pulmonaires (FAVP), améliorel’hématose et atténue le développement de l’HTAP soutenant cliniquement le maintien de ce fluxlors de la création d’une CBP. Par ailleurs, la perte de pulsatilité, en diminuant le contrainte de cisaillement, entraîne unediminution de l’eNOS synthase et une réponse altérée vaso-relaxante dépendante de l'endothélium artérielle pulmonaire. La micropulsatilité limite ces effets délétères. Ces résultats impliquent desthérapies potentielles contre l’HTAP du Fontan, en maintenant un débit pulmonaire accessoire et la modulation pharmaceutique vaso-relaxante non endothélium-dépendant