Cinética de reacciones químicas a través de observables

1 archivo PDF (7 páginas). "Congreso Internacional de Docencia e Investigación en Química."El concepto de observable en la cinética química es un tema poco abordado en los cursos y textos del tema. Este artículo muestra ejemplos en donde la velocidad de reacción se monitorea a través de métodos indirectos de medir la concentración en el tiempo. Consiste en medir el valor de una propiedad física llamada observable que es proporcional a la concentración de alguno de los reactantes o productos. Esta propiedad puede ser tratada con métodos estadísticos no aplicados en los textos de cinética por lo que será un procedimiento alternativo al tradicional, en donde los datos se aplican directamente al método cinético requerido. El tratamiento cinético con observables y ajustes estadísticos desarrollan competencias para el tratamiento de datos y uso de métodos fisicoquímicos indirectos. PALABRAS CLAVE: Observables. Cinética, Estadística.The concept of observable in chemical kinetics is a subject rarely addressed in the courses and texts the subject. This article shows examples where the reaction rate is monitored through indirect methods of measuring the concentration in time. It consists in measuring the value of a physical property called observable which is proportional to the concentration of any of the reactants or products. This property can be treated with statistical methods are not applied kinetic texts so it will be an alternative to the traditional procedure, where data are applied directly to the required rate method. The kinetic treatment with observable and statistical adjustments, develop skills for data processing and use of indirect physicochemical methods. KEYWORDS: Observable. Kinetic. Statistical.Universidad Autónoma Metropolitana (México), Unidad Azcapotzalco, División de Ciencias Básicas e Ingeniería, Departamento de Ciencias Básicas, Área de Química Aplicada -- Universidad Autónoma Metropolitana (México), Unidad Azcapotzalco, División de Ciencias Básicas e Ingeniería, Departamento de Ciencias Básicas

Aplicación de un sistema de tutorización personalizada para estudiantes de grado y master

Memoria ID-320. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2013-2014

Using the emotional functioning in clinical practice to detect psychological distress in patients with advanced thoracic and colorectal cancer

Purpose: Patients with advanced cancer suffer significant decline of their psychological state. A rapid and reliable evaluation of this state is essential to detect and treat it and improve quality of life. The aim was to probe the usefulness of the emotional function (EF) subscale of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EF-EORTC-QLQ-C30) to assess psychological distress in cancer patients. Methods: This is a multicenter, prospective, observational study involving 15 Spanish hospitals. Patients diagnosed with unresectable advanced thoracic or colorectal cancer were included. Participants completed the Brief Symptom Inventory 18 (BSI-18), the current the gold standard, and the EF-EORTC-QLQ-C30 to assess their psychological distress prior to initiating systemic antineoplastic treatment. Accuracy, sensitivity, positive predictive value (PPV), specificity, and negative predictive value (NPV) were calculated. Results: The sample comprised 639 patients: 283 with advanced thoracic cancer and 356 with advanced colorectal cancer. According to the BSI scale, 74% and 66% displayed psychological distress with an EF-EORTC-QLQ-C30 accuracy of 79% and 76% in detecting psychological distress in individuals with advanced thoracic and colorectal cancer, respectively. Sensitivity was 79 and 75% and specificity was 79 and 77% with a PPV of 92 and 86% and a NPV of 56 and 61% (scale cut-off point, 75) for patients with advanced thoracic and colorectal cancer, respectively. The mean AUC for thoracic cancer was 0.84 and, for colorectal cancer, it was 0.85. Conclusion: This study reveals that the EF-EORTC-QLQ-C30 subscale is a simple and effective tool for detecting psychological distress in people with advanced cancer

Cinética de reacciones químicas a través de observables

El concepto de observable en la cinética química es un tema poco abordado en los cursos y textos del tema. Este artículo muestra ejemplos en donde la velocidad de reacción se monitorea a través de métodos indirectos de medir la concentración en el tiempo. Consiste en medir el valor de una propiedad física llamada observable que es proporcional a la concentración de alguno de los reactantes o productos. Esta propiedad puede ser tratada con métodos estadísticos no aplicados en los textos de cinética por lo que será un procedimiento alternativo al tradicional, en donde los datos se aplican directamente al método cinético requerido. El tratamiento cinético con observables y ajustes estadísticos desarrollan competencias para el tratamiento de datos y uso de métodos fisicoquímicos indirectos.The conceptof observable in chemical kinetics is a subject rarely addressed in the courses and texts the subject. This article shows examples where the reaction rate is monitored through indirect methods of measuring the concentration in time. It consists in measuring the value of a physical property called observable which is proportional to the concentration of any of the reactants or products. This property can be treated with statistical methods are not applied kinetic texts so it will be an alternative to the traditional procedure,where data are applied directly to the required rate method. The kinetic treatment with observable and statistical adjustment

Plasma Treatment of Agave

Composites based on low-density polyethylene (LDPE) were prepared with Agave fiber powder (AFP) that was coated by plasma polymerization process using ethylene gas. Treated and pristine AFP were analyzed by infrared spectroscopy, scanning electron microscopy, and contact water angle for the assessment of surface properties. The polymer composites were prepared by melt mixing using 0, 5, 10, and 20 wt% of AFP and their mechanical and thermal properties were measured. Dispersion evaluation in water confirmed that the AFP treated changed from hydrophilic to hydrophobic behavior and it was also corroborated with water contact angle tests. The addition of treated and untreated AFP (200 mesh) at 20 wt% promotes an increase of Young’s modulus of the composites of up to 60% and 32%, respectively, in relation to the neat matrix. Also, an increase of crystallinity of LDPE was observed by the addition of treated and untreated AFP; however no significant effect on the crystallization temperature was observed in LDPE containing AFP

Técnica de ajuste de las curvas concentración en cinética química

El análisis de regresión es una técnica para investigar y modelar la relación entre variables. Aplicaciones de regresión son numerosas y ocurren en casi todos los campos, incluyendo ingeniería. Este artículo muestra la aplicación innovadora del método estadístico a las curvas de concentración u observables versus tiempo para ajustar los datos experimentales en una cinética química, los ejemplos son: cinéticas realizadas por los alumnos de la materia experimental Cinética y Catálisis de la Universidad Autónoma Metropolitana-Azcapotzalco y de datos obtenidos de la literatura. Los resultados: en la curva de concentración contra tiempo y orden de reacción aplicando el ajuste muestran coeficiente de correlación o regresión aceptables. El aprendizaje se hace significativo al obtener coherencia en los resultados experimentales y/o los reportados en la literatura.Regression analysis is a statistical tool for the investigation of relationships between variables. Applications of regression analysis exist in almost every field of knowledge including engineering. The purpose of the present paper is to show the innovative application of statistical method for concentration versus time curves to fit the experimental data on chemical kinetics, examples are kinetic studies performed by the students of the experimental course Kinetics and Catalysis of the Universidad Autónoma Metropolitana-Azcapotzalco and data from the literature. The results: in concentration versus time curve and order of reaction show acceptable correlation coefficient or regression. Learning becomes significant to obtain consistency in the experimental results and/or data reported in the literature

Effectiveness of conservative treatment according to severity and systemic disease in carpal tunnel syndrome: A systematic review

(1) Background: Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy in the upper extremity. Conservative treatment has been effective for mild and moderate idiopathic CTS. However, severe CTS and systemic conditions were an exclusion criterion from the studies. The aim of this study is to review the effectiveness of conservative treatment in patients with CTS regardless of the level of severity and the presence or not of systemic diseases in the last ten years. (2) Methods: Randomized controlled clinical trials that compared the effect of conservative treatment on the Boston questionnaire and pain were selected. PubMed, PEDro, Scopus, Cochrane, and Web of Science databases were used. PRISMA statement checklist was performed. (3) Results: 876 studies were recorded, 29 were selected. Pharmacology, Electrotherapy and Manual Therapy had benefits for CTS. Electrotherapy and manual therapy could be effective for severe CTS patients with a systemic condition in the short term, but there was a low percentage of these patients included in the studies. (4) Conclusion: Some pharmacological treatments, manual therapy and electrotherapy have shown benefits for handling CTS, although the most effective combination of techniques is unknown. It would be necessary to include patients with systemic conditions in the selection criteria for future studies

Transcriptome analysis reveals molecular profiles associated with evolving steps of monoclonal gammopathies

This is an open-access paper.-- et al.A multistep model has been proposed of disease progression starting in monoclonal gammopathy of undetermined significance continuing through multiple myeloma, sometimes with an intermediate entity called smoldering myeloma, and ending in extramedullary disease. To gain further insights into the role of the transcriptome deregulation in the transition from a normal plasma cell to a clonal plasma cell, and from an indolent clonal plasma cell to a malignant plasma cell, we performed gene expression profiling in 20 patients with monoclonal gammopathy of undetermined significance, 33 with high-risk smoldering myeloma and 41 with multiple myeloma. The analysis showed that 126 genes were differentially expressed in monoclonal gammopathy of undetermined significance, smoldering myeloma and multiple myeloma as compared to normal plasma cell. Interestingly, 17 and 9 out of the 126 significant differentially expressed genes were small nucleolar RNA molecules and zinc finger proteins. Several proapoptotic genes (AKT1 and AKT2) were down-regulated and antiapoptotic genes (APAF1 and BCL2L1) were up-regulated in multiple myeloma, both symptomatic and asymptomatic, compared to monoclonal gammopathy of undetermined significance. When we looked for those genes progressively modulated through the evolving stages of monoclonal gammopathies, eight snoRNA showed a progressive increase while APAF1, VCAN and MEGF9 exhibited a progressive downregulation. In conclusion, our data show that although monoclonal gammopathy of undetermined significance, smoldering myeloma and multiple myeloma are not clearly distinguishable groups according to their gene expression profiling, several signaling pathways and genes were significantly deregulated at different steps of the transformation process.This study was partially supported by Spanish FIS (PI080568, PS09/01450 and PS0901897), “Gerencia Regional de Salud, Junta de Castilla y León” (GRS 702/A/11) grant, and the Spanish Myeloma Network Program (RD06/0020/0006, RD12/0036/0058 and RD12/0036/0046).Peer Reviewe