Preoperative biliary drainage in severely jaundiced patients with pancreatic head cancer: A retrospective cohort study

Background: Guidelines recommend against preoperative biliary drainage (PBD) in patients with pancreatic head cancer if bilirubin levels are = 250 and = 250 versus = 250. PBD technical success (83% vs. 81%, p = 0.80) and PBD related complications (33% vs. 29%, p = 0.60) did not differ between these groups. Analyzing bilirubin levels >= 250 versus = 250 and < 250. Our study does not support a different approach regarding PBD in patients with severe jaundice.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Die lagerlose Pumpe für hohe Fluidtemperaturen

Bearingless motors consist of a drive system with an integrated magnetic bearing and are used in centrifugal pumps for high purity applications. The machine is constructed without the use of a drive shaft, dynamic seals, and conventional mechanical bearings, since the rotor is levitated in a magnetic field. This allows for a wear-free operation and prevents the contamination of process fluids. Bearingless pumps are employed in wet chemical etching processes in the semiconductor industry, since low contamination is required due to the small structures on the wafer. The reaction speed of etching processes depends strongly on the temperature of the used chemicals. Therefore, high fluid temperatures are required in order to increase processing speed and yield. State of the art, commercially available bellows pumps are rated for 210 °C and bearingless pumps can be used for fluid temperatures of 90 °C with passive air cooling and 180 °C with active water cooling. This work is focused on increasing the admissible fluid temperature of a passively cooled bearingless pump to 250 °C. The number of components and, therefore, the complexity, the cost and the probability of failure are minimized by omitting an active cooling system. Challenges include the appropriate choice of materials, the construction of the components and the development of a sensing and closed-loop control scheme for high temperatures. The temperature distribution in the pump is calculated by using a thermal model, which is based on the analysis of the temperature-dependent performance of the bearingless pump, the internal losses and the heat transfer mechanisms. The choice of materials and the construction of the pump are based on the results of the thermal model. The motor utilizes a novel closed-loop, angle sensorless control scheme for bearingless machines. The rotor angle is obtained with a two-stage estimator consisting of a model-based low-speed and a back electromotive force-based high-speed angle observer. The controller enables closed loop operation at all rotational speeds and at standstill. Two prototypes of the bearingless high temperature pump were constructed and manufactured. Both machines were tested with fluid temperatures of up to 250 °C without failure of components. This proves that bearingless pumps can be employed successfully in extreme temperature applications

Preoperative biliary drainage in severely jaundiced patients with pancreatic head cancer: A retrospective cohort study

Background: Guidelines recommend against preoperative biliary drainage (PBD) in patients with pancreatic head cancer if bilirubin levels are = 250 and = 250 versus = 250. PBD technical success (83% vs. 81%, p = 0.80) and PBD related complications (33% vs. 29%, p = 0.60) did not differ between these groups. Analyzing bilirubin levels >= 250 versus = 250 and < 250. Our study does not support a different approach regarding PBD in patients with severe jaundice

Functional expression and characterization of a Drosophila odorant receptor in a heterologous cell system

Odorant receptors (ORs) constitute the molecular basis for the detection of volatile odorous molecules and the perception of smell. Our understanding of chemical senses has been greatly expanded by the discovery of the OR gene families in vertebrates and in the nematode Caenorhabditis elegans. Recently, candidate Drosophila OR genes have been identified. The putative ORs do not possess any primary sequence identity with known vertebrate or C. elegans receptors, but belong to the family of G protein-coupled receptors according to their predicted seven transmembrane topology. To prove olfactory function of these proteins, we expressed a member of the putative Drosophila OR gene family, Or43a, in Xenopus laevis oocytes. Using two-electrode voltage-clamp recording we identified four odors (cyclohexanone, cyclohexanol, benzaldehyde, and benzyl alcohol) that activated the receptor at low micromolar concentration and structurally related substances that did not. This report shows the function and specificity of a member of the recently identified family of Drosophila ORs expressed in a heterologous system