Synthesis, characterization and color performance of novel Co²+-doped alumina/titania nanoceramic pigments.

Blue-green nanoceramic pigments from Co(2+)-doped alumina-titania (xCo(2+)-Al(2)O(3)/TiO(2)) have been synthesized by alkoxide sol-gel route from a mixture of titania and boehmite sols that derived from titanium isopropoxide and aluminum nitrate precursors. The composition of the alumina/titania (AT) matrix is 3:1M ratio. A series of xCo(2+):3TiO(2):1Al(2)O(3) mixed oxides with different Co(2+)-dopant ion concentration has been prepared. The molar ratio of the Co(2+)-dopant ion in the Al(2)O(3)/TiO(2) matrix is from x=0 to 0.5M ratio relative to the titania composition. Characterizations of Co(2+)-doped alumina/titania nanocomposites are carried out using reflectance spectroscopy, transmission electron microscope (TEM), scanning electron microscopy (SEM-EDS), thermo-gravimetric analysis (TGA) and X-ray diffractometer (XRD). The experimental results demonstrated that the prepared Co(2+)-doped alumina-titania nanocomposites fulfill the current technological requirements for ceramic pigment applications that exhibit a high physico-chemical and thermal stabilities at high firing temperatures.

Effect of general and epidural anesthesia on hemostasis and fibrinolysis in hepatic patients.

This study was designed to compare the effect of general anesthesia using isoflurane and epidural anesthesia using ropivacaine on hemostasis in hepatic patients. Sixty patients were randomly allocated into two groups to receive either general or epidural anesthesia which further subdivided into control and hepatic subgroups. Blood samples were collected preoperatively, immediate post-operatively and on third post-operative day to measure hemoglobin (Hb), platelet count (PLT),), prothrombin time (PT), partial thromboplastin time (PTT), and thrombin time (TT). Specific hemostatic and fibrinolytic parameters were also included; von Willebrand factor (vWF), soluble platelet selectin (sP-selectin), prothrombin fragment (PF(1+2)), tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and D-dimer. Hemoglobin showed a significant post-operative decrease in all subgroups. Post-operative changes of PLT, PT, PTT and TT were comparable between general and epidural anesthesia. General anesthesia showed a marked significant increase in specific parameters compared to epidural anesthesia. This study concluded that epidural ropivacaine anesthesia provided better hemostatic stability especially in hepatic patients.