Fabrication and aero dynamic levitation of chalcogenide glass spheres

Spheres of gallium-lanthanum sulphide (GLS) and gallium lanthanum sulphite (GLSO) have been produced by laser irradiation on a copper hearth. Although similar fabrication techniques have been applied to oxide glasses, the technique has been overlooked for the production of chalcogenide glasses due to the perceived problem of the volatility of the chalcogens. In this work, glass microspheres of GLS/GLSO have been fabricated by laser irradiation of micron size irregular shaped glass particles on a Cu plate. In this material we found that evaporation of sulphur was not substantial as it appears to be more strongly chemically bound [1]. In addition to this method we have also established that it is possible to form larger spheres (mm diameter) of GLSO by aerodynamic levitation and laser heating using a CO2 laser (10.6 µm wavelength). Our studies involve overheating and supercooling of liquids and melts, outgassing analysis, high temperature resistivity measurements, and crystallization/structural studies [1-3]. In both fabrication methods the glasses could be melted and re-vitrified with low sulphur mass loss. We conclude that the production of glass spheres by laser irradiation[4] from irregular shaped starting material on a substrate using the wetting principle has substantial benefits for making microspheres and nanospheres

Postchemoembolisation syndrome – tumour necrosis or hepatocyte injury?

Transarterial chemoembolisation of liver tumours is typically followed by elevated body temperature and liver transaminase enzymes. This has often been considered to indicate successful embolisation. The present study questions whether this syndrome reflects damage to tumour cells or to the normal hepatic tissue. The responses to 256 embolisations undertaken in 145 patients subdivided into those with hepatocyte-derived (primary hepatocellular carcinoma) and nonhepatocyte-derived tumours (secondary metastases) were analysed to assess the relative effects of tumour necrosis and damage to normal hepatocytes in each group. Cytolysis, measured by elevated alanine aminotransferase, was detected in 85% of patients, and there was no difference in the abnormalities in liver function tests measured between the two groups. Furthermore, cytolysis was associated with a higher rate of postprocedure symptoms and side effects, and elevated temperature was associated with a worse survival on univariate analysis. Multivariate analysis demonstrated that there was no benefit in terms of survival from having elevated temperature or cytolysis following embolisation. Cytolysis after chemoembolisation is probably due to damage to normal hepatocytes. Temperature changes may reflect tumour necrosis or necrosis of the healthy tissue. There is no evidence that either a postchemoembolisation fever or cytolysis is associated with an enhanced tumour response or improved long-term survival in patients with primary or secondary liver cancer

Decrease in the production of beta-amyloid by berberine inhibition of the expression of beta-secretase in HEK293 cells

<p>Abstract</p> <p>Background</p> <p>Berberine (BER), the major alkaloidal component of <it>Rhizoma coptidis</it>, has multiple pharmacological effects including inhibition of acetylcholinesterase, reduction of cholesterol and glucose levels, anti-inflammatory, neuroprotective and neurotrophic effects. It has also been demonstrated that BER can reduce the production of beta-amyloid_40/42, which plays a critical and primary role in the pathogenesis of Alzheimer's disease. However, the mechanism by which it accomplishes this remains unclear.</p> <p>Results</p> <p>Here, we report that BER could not only significantly decrease the production of beta-amyloid_40/42and the expression of beta-secretase (BACE), but was also able to activate the extracellular signal-regulated kinase1/2 (ERK1/2) pathway in a dose- and time-dependent manner in HEK293 cells stably transfected with APP695 containing the Swedish mutation. We also find that U0126, an antagonist of the ERK1/2 pathway, could abolish (1) the activation activity of BER on the ERK1/2 pathway and (2) the inhibition activity of BER on the production of beta-amyloid_40/42and the expression of BACE.</p> <p>Conclusion</p> <p>Our data indicate that BER decreases the production of beta-amyloid_40/42by inhibiting the expression of BACE via activation of the ERK1/2 pathway.</p