Limb remote ischemic conditioning of the recipient protects the liver in a rat model of arterialized orthotopic liver transplantation

Background Ischemic-reperfusion (IR) injury still represents a major concern in clinical transplantation, especially in the era of extreme organ shortage and extended criteria donor organs. In the present study we aimed to investigate the hepatoprotective effects of remote ischemic conditioning (RIC) in a rat model of arterialized orthotopic liver transplantation (OLT). Methods Male Lewis rats were used (n = 144 / 72 OLT cases; 240-340g) as donors and recipients. Livers were flushed and stored in 4 degrees C HTK-solution for 8h before implantation. Recipients were randomly allocated into three experimental groups: RIC 1, RIC 2, Control. In RIC 1, RIC 2 groups, RIC was applied in the recipient before hepatectomy or after reperfusion (4x5-5min IR via clamping the infrarenal aorta), respectively. Animals were sacrificed at 1, 3,24,168h post-reperfusion (n = 6 recipient/group/time point). Hepatocellular injury, graft circulation, serum cytokines, tissue redox-stress and adenosine-triphosphate (ATP) levels have been assessed. Additional markers were analyzed, using Western blotting and reverse-transcription polymerase chain reaction. Results RIC 1 group showed significantly (p<0.05) improved portal venous and microcirculation flow as well as velocity. RIC has significantly reduced tissue injury according to the serum levels of transaminases and results of histopathological evaluation. Reduced TUNEL-staining (p<0.01 RIC 1-2 vs. Control) and elevated pBAD/BAD ratio was detected in the RIC groups (p<0.01 RIC 1 vs. Control). Supporting findings were obtained from measurements of serum IL-10 as well as tissue malondialdehyde and ATP levels. Hemoxygenase-1 (HO-1) mRNA-expression was significantly higher in RIC 1 compared to Control (p<0.05 RIC 1 vs. Control). Conclusion These results suggest that RIC might confer potent protection against the detrimental effects of IR injury including tissue damage, apoptosis, graft circulation, inflammation, tissue energetic status in OLT. HO-1 overexpression might play an orchestrating role in RIC mediated organ protection. An earlier intervention (RIC 1 protocol) was more effective than remote conditioning after graft reperfusion

Microscopic analysis of the morphology of seams in friction stir welded polypropylene

Supermolecular structure of welded seams prepared by friction stir welding (FSW) of polypropylene sheets has been studied by optical and electron microscopy. It has been shown that in the central parts of the seam spherulitic structures similar to that of the base material are formed, while at the borderline of the seam, a complex supermolecular structure could be identified. Lower welding rotation speed resulted in a border transition zone of more complex feature than the higher rotation speed during FSW. This was accompanied by reduced joint efficiency

248 nm laser interaction studies on LaF3/MgF2 optical coatings by cross sectional transmission electron microscopy

LaF3/MgF2 high-reflectance optical multilayer coatings were deposited by e-beam evaporation and investigated by cross-sectional transmission electron microscopy concentrating on the evolution of the film structure during growth and due to laser irradiation. The irradiated samples show enhanced texture compared to the as deposited films, indicating that recrystallization took place due to the laser irradiation. The waviness of the interfaces between the single quarter-wave sublayers in the multilayer system increases withincreasing distance from the substrate. This effect may result in increased scatter losses, especially in the ultraviolet spectral region

Solar neutrino spectroscopy (before and after superkamiokande)

hep-ph 9611435Biblioteca Centrale CNR / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Ethylene-octene copolymer (POE) toughened polyamide 6/polypropylene nanocomposites : effect of POE maleation

Ethylene-octene elastomer (POE) and ethylene-octene elastomer grafted maleic anhydride (POEgMAH) toughened nanocomposites of polyamide 6/polypropylene (PA6/PP) containing 4 wt% organophilic modified montmorillonite (MMT) were produced by melt compounding followed by injection moulding. The PA6/PP composition was kept constant (PA6/PP = 70/30 parts) while the elastomer (either POE or POEgMAH) content varied between 5 and 20 wt%. PP grafted maleic anhydride (PPgMAH) was used to compatibilize the blend system. The impact strength of the nanocomposite system was examined by the conventional Izod impact test at room temperature (RT). In addition, linear elastic fracture mechanics (LEFM) approach was used to study the fracture response of the notched three point bending type specimens at room temperature (RT) and -40 degrees C. Fracture surfaces of the broken specimens were examined using scanning electron microscopy. The results show that while POEgMAH can remarkably improve the compatibility between PA6 and the elastomer thus increasing the toughness, the unmodified POE has less significant contribution to PA6/PP/organoclay toughness. Elastomer domains of POEgMAH show a finer and more uniform dispersion than that of POE in the PA6/PP/organoclay matrix. It is also observed that the toughness increased with the increasing elastomer concentration for both unmaleated and maleated POE