El curso de epidemiología es un curso de especialidad en las carreras de la Facultad de Ciencias de la Salud, de carácter teórico-práctico, dirigido a estudiantes de sétimo ciclo de la carrera de Medicina. La epidemiología como ciencia básica es fundamental en la formación de los médicos; ha sido definida como la "lógica de la medicina moderna" y a partir de la aplicación del raciocinio epidemiológico surgió la nueva corriente de la "Medicina basada en Evidencias". La epidemiología cumple un rol integrador entre las ciencias básicas y las ciencias clínicas, así como entre la medicina recuperativa y la medicina preventiva. En este curso el estudiante aprenderá a comprender como evolucionan las enfermedades, aprenderá cómo se mide la frecuencia de la enfermedad, cómo se investiga la causa de las enfermedades, cómo se investiga una epidemia, cómo se hace un diagnóstico de la situación de salud de una población, identificando los grupos poblacionales de mayor riesgo y proponiendo medidas de prevención y control. El curso de epidemiología busca desarrollar las competencias generales de Razonamiento Cuantitativo al lograr la capacidad para trabajar con datos alfanúmericos y/o gráficos para resolver problemas del contexto cotidiano para sacar conclusiones y contribuir argumentos basados en resultados válidos en el nivel 2; y la competencia general de Manejo de Información al lograr la capacidad para buscar y seleccionar información de forma eficiente y efectiva, además de evaluar críticamente la calidad y veracidad de la misma utilizándola de manera ética y responsable en el nivel 2. Asimismo, busca desarrollar la competencia específica de Salud Pública de I. INFORMACIÓN GENERAL CURSO : Epidemiología CÓDIGO : ME21 CICLO : 201801 CUERPO ACADÉMICO : Arrasco Alegre, Juan Carlos Cabrera Champe, Rufino Condor Rojas, Yudy Cley Cáceres Mejía, Brenda Napanga Saldaña, Edwin Omar Nepo Linares, Edgardo Pardo Ruiz, Karim Jacqueline Poquioma Rojas, Ebert Carlos Valdéz Huarcaya, William Vicuña Olivera, Marisol Roxana CRÉDITOS : 4 SEMANAS : 16 HORAS : 2 H (Laboratorio) Semanal /2 H (Práctica) Semanal /2 H (Teoría) Semanal ÁREA O CARRERA : Medicina II. MISIÓN Y VISIÓN DE LA UPC Misión: Formar líderes íntegros e innovadores con visión global para que transformen el Perú. Visión: Ser líder en la educación superior por su excelencia académica y su capacidad de innovación. 2 Diagnóstico Situacional al lograr la capacidad para describir y priorizar los problemas de salud de la comunidad en el nivel 2. La epidemiología en la enseñanza de la medicina es imprescindible para el entendimiento del proceso salud enfermedad, de los determinantes y factores de riesgo, de la eficacia y efectividad terapéutica, de la certeza diagnóstica, así como, del establecimiento de un pronóstico. El uso del método epidemiológico a través de los años ha permitido brindar importantes aportes a la medicina y a la ciencia, a la vez, que el método fue perfeccionándose y lo continúa haciendo.

The desire for energy and resource savings brings magnesium alloys as lightweight materials with high specific strength more and more into the focus. Most structural components are subjected to cyclic loading. In the course of computer aided product development, a numerical prediction of the fatigue life under these conditions must be provided. For this reason, the mechanical properties of the considered material must be examined in detail. Wrought magnesium semifinished products, e.g. magnesium sheet metals, typically reveal strong basal textures and thus, the mechanical behavior considerably differs from that of the well-established magnesium die castings. Magnesium sheet metals reveal a distinct difference in the tensile and compressive yield stress, leading to non-symmetric sigmoidal hysteresis loops within the elasto-plastic load range. These unusual hysteresis shapes are caused by cyclic twinning and detwinning. Furthermore, wrought magnesium alloys reveal pseudoelastic behavior, leading to nonlinear unloading curves. Another interesting effect is the formation of local twin bands during compressive loading. Nevertheless, only little information can be found on the numerical fatigue analysis of wrought magnesium alloys up to now. The aim of this thesis is the investigation of the mechanical properties of wrought magnesium alloys and the development of an appropriate fatigue model. For this purpose, twin roll cast AM50 as well as AZ31B sheet metals and extruded ME21 sheet metals were used. Mechanical tests were carried out to present a comprehensive overview of the quasi-static and cyclic material behavior. The microstructure was captured on sheet metals before and after loading to evaluate the correlation between the microstructure, the texture, and the mechanical properties. Stress- and strain-controlled loading ratios and strain-controlled experiments with variable amplitudes were performed. Tests were carried out along and transverse to the manufacturing direction to consider the influence of the anisotropy. Special focus was given to sigmoidal hysteresis loops and their influence on the fatigue life. A detailed numerical description of hysteresis loops is necessary for numerical fatigue analyses. For this, a one-dimensional phenomenological model was developed for elasto-plastic strain-controlled constant and variable amplitude loading. This model consists of a three-component equation, which considers elastic, plastic, and pseudoelastic strain components. Considering different magnesium alloys, good correlation is reached between numerically and experimentally determined hysteresis loops by means of different constant and variable amplitude load-time functions. For a numerical fatigue life analysis, an energy based fatigue parameter has been developed. It is denoted by “combined strain energy density per cycle” and consists of a summation of the plastic strain energy density per cycle and the 25 % weighted tensile elastic strain energy density per cycle. The weighting represents the material specific mean stress sensitivity. Applying the energy based fatigue parameter on modeled hysteresis loops, the fatigue life is predicted adequately for constant and variable amplitude loading including mean strain and mean stress effects. The combined strain energy density per cycle achieves significantly better results in comparison to conventional fatigue models such as the Smith-Watson-Topper model. The developed phenomenological model in combination with the combined strain energy density per cycle is able to carry out numerical fatigue life analyses on magnesium sheet metals.

The desire for energy and resource savings brings magnesium alloys as lightweight materials with high specific strength more and more into the focus. Most structural components are subjected to cyclic loading. In the course of computer aided product development, a numerical prediction of the fatigue life under these conditions must be provided. For this reason, the mechanical properties of the considered material must be examined in detail. Wrought magnesium semifinished products, e.g. magnesium sheet metals, typically reveal strong basal textures and thus, the mechanical behavior considerably differs from that of the well-established magnesium die castings. Magnesium sheet metals reveal a distinct difference in the tensile and compressive yield stress, leading to non-symmetric sigmoidal hysteresis loops within the elasto-plastic load range. These unusual hysteresis shapes are caused by cyclic twinning and detwinning. Furthermore, wrought magnesium alloys reveal pseudoelastic behavior, leading to nonlinear unloading curves. Another interesting effect is the formation of local twin bands during compressive loading. Nevertheless, only little information can be found on the numerical fatigue analysis of wrought magnesium alloys up to now. The aim of this thesis is the investigation of the mechanical properties of wrought magnesium alloys and the development of an appropriate fatigue model. For this purpose, twin roll cast AM50 as well as AZ31B sheet metals and extruded ME21 sheet metals were used. Mechanical tests were carried out to present a comprehensive overview of the quasi-static and cyclic material behavior. The microstructure was captured on sheet metals before and after loading to evaluate the correlation between the microstructure, the texture, and the mechanical properties. Stress- and strain-controlled loading ratios and strain-controlled experiments with variable amplitudes were performed. Tests were carried out along and transverse to the manufacturing direction to consider the influence of the anisotropy. Special focus was given to sigmoidal hysteresis loops and their influence on the fatigue life. A detailed numerical description of hysteresis loops is necessary for numerical fatigue analyses. For this, a one-dimensional phenomenological model was developed for elasto-plastic strain-controlled constant and variable amplitude loading. This model consists of a three-component equation, which considers elastic, plastic, and pseudoelastic strain components. Considering different magnesium alloys, good correlation is reached between numerically and experimentally determined hysteresis loops by means of different constant and variable amplitude load-time functions. For a numerical fatigue life analysis, an energy based fatigue parameter has been developed. It is denoted by “combined strain energy density per cycle” and consists of a summation of the plastic strain energy density per cycle and the 25 % weighted tensile elastic strain energy density per cycle. The weighting represents the material specific mean stress sensitivity. Applying the energy based fatigue parameter on modeled hysteresis loops, the fatigue life is predicted adequately for constant and variable amplitude loading including mean strain and mean stress effects. The combined strain energy density per cycle achieves significantly better results in comparison to conventional fatigue models such as the Smith-Watson-Topper model. The developed phenomenological model in combination with the combined strain energy density per cycle is able to carry out numerical fatigue life analyses on magnesium sheet metals.