ABSTRACT
In two-dimensional turbulent systems the redistribution of energy can be described by quadratic nonlinear three-wave interactions, which are limited by resonance conditions. The set of coupling modes can be understood as resonant manifold. It has been predicted by theory that, in the presence of a shear flow, the resonant manifold in wave-number space shrinks in time favoring large-scale structures. The phenomenon of manifold shrinking in the presence of shear flows is studied the first time experimentally in drift wave turbulence at the stellarator TJ-K by bicoherence analysis. By estimating effective mode numbers characterizing the width of the manifold, it is demonstrated that increasing shear leads to a shrinking of the resonance manifold.
ABSTRACT
RESUMEN La enfermedad intestinal inflamatoria comprende un grupo de afecciones intestinales crónicas idiopáticas, siendo las dos formas principales la enfermedad de Crohn y la colitis ulcerosa. Su incidencia es variable de acuerdo al área analizada y se encuentra in crescendo a nivel global. Entre las complicaciones extraintestinales se encuentra la baja masa ósea, que puede conducir a osteopenia, osteoporosis y fracturas. Su prevalencia es elevada y varía según los estudios analizados. La fisiopatogenia es multifactorial y parcialmente entendida, incluye factores de riesgos generales para toda la población y otros que son específicos de la enfermedad o presentan particularidades. En cuanto a las recomendaciones sobre screening y tratamiento, son extrapoladas de otras guías de osteoporosis, donde la base fisiopatogenia es diferente. Finalmente, a pesar de que se reconoce el riesgo aumentado de pérdida ósea en este grupo de pacientes, existe una baja adherencia de los médicos al uso de las guías. Por lo cual, sería importante continuar con la educación médica, para poder realizar un reconocimiento temprano de la enfermedad ósea e implementar estrategias de tratamiento oportunas.
ABSTRACT
Between 1980 and 1995, 11 children with osteosarcoma were treated at the Clinic of Pediatric Surgery of the Martin-Luther-University, Halle-Wittenberg. In the first years of this period we treated six of the children according to the protocols of the study group "Tumors" of the Society for Pediatric Surgery. At that time the preferred concept was radical surgical resection followed by adjuvant chemotherapy. For several years we favored the therapeutic regime of the Society for Pediatric Oncology and Hematology and treated five children according to the principles of the cooperative studies of osteosarcoma. With the introduction of aggressive neo-adjuvant chemotherapy it was possible to perform reconstructive limb surgery. We report on our own first experiences with the "Clavicula pro humero", an operation according to Winkelmann for malignant bone tumors of the proximal humerus. This new operative method is described and possible complications are discussed.