Physical and mathematical modeling of erosion processes across the scales

Internal erosion is the interaction of micro-scale hydraulic and mechanic processes taking place within the soil structure leading to macro-scale damages causing failures of whole constructions. While the geometrical and hydraulic conditions on the macro-scale supporting erosion are well investigated, the processes involved in the onset and continuation of erosion, the conditions influencing its temporal evolution are not well understood. The investigation of the processes involved in internal erosion requires a bijective or one-to-one approach with simultaneously implemented physical experiments and computational modelling on both relevant scales, micro- or pore-scale and macro- or continuum-scale. The aim of this approach is to accomplish an improved understanding of the underlying physics to be able to transfer this new knowledge into computational models enabling the solving of problems on the technical scale

Local Use Of Ankaferd Blood Clotter In Emergent Beating Heart Coronary Artery Bypass Grafting

Background: Severe beeding which requiring massive blood transfusion after emergent beating heart surgery is shown to be 1–3%. Therefore, complications and side effects of transfusion can be seen. The aim of this study was to investigate the effectiveness of Ankaferd blood clotter (ABC) as a new topical herbal blood clotter to decrease mediastinal bleeding in emergent beating heart CABG patients who medicated with clopidogrel and acetyl salisilic acite (ASA) prior to CABG surgery. Materials and Methods: 25 CABG patients received a high dose clopidogrel (600 mgr) and 300 mgr ASA have been included into the study (ABC group). 25 patients have also been included into the study for comparison (placebo group, PG). After the administration of protamine sulphate, a 10 ml of ABC solution has been sprayed to the surgical area including mediastinum and epicardial sac. We compared mediastinal drenaige, reoperation due to tamponade, and required blood and blood products in both groups. Results: The mean amount of bleeding after operation was 230 ml in ABC group, and 490 ml in CG (P=0.001). In ICU, bleeding in ABC group and CG was 410ml and 680ml, respectively (P=0.0022). The mean total bleeding from mediastinum was 530±280 mL and 990±440 mL In ABC and CG group, respectively (P=0.001). The amount of autotransfusion was as follows: 175 mL in ABC group, and 290 mL in CG (P=0.002). No patient needed the surgical revision in ABC group, but four patients (16%) from CG group because of cardiac tamponade. Seventeen patients from CG required blood transfusion due to low hematocrite level postoperatively. In CG, the mean hematocrite level was 17±2,3. Transfusion of fresh frozen plasma and platelets in ABC group and CG were as follows: 0.2 and 0 in ABC group, and 0.3and 0.4 in CG. Conclusion: Our study showed that the local use of 10 mL ABC reduces bleeding significantly. Therefore, transfusion requirements of PRBC, platelets, and total blood units in patients on clopidogrel and ASA undergoing emergent beating heart CABG. To provide cardiac tamponade because of excessive mediastinal bleeding and requirement of blood transfusion after emergent CABG patients who previously administered clopidogrel and ASA, we propose local use of ABC solution as a potent coagulant agent.PubMe

A engenharia genética Genetic engineering

São abordados os progressos havidos com as técnicas de engenharia genética, capazes de alterar o potencial genético de um organismo, quer pela introdução, quer pela supressão de novos genes estruturais. São mencionadas algumas das aplicações em geral e, em particular, possibilidades de uso no campo da medicina. É feita uma análise crítica dos benefícios e riscos envolvidos.<br>This paper deals with the progress made in genetic engineering techniques, capable of altering the genetic potential of an organism, either by the introduction or the suppression of new structural genes. Some of the general applications are described as are also, more particularly, their uses in the field of medicine. A critical analysis of the benefits and risks involved is also undertaken