Effects of Chronic Cerebellar Stimulation on Chronic Limbic Seizures in Monkeys

No influences of chronic cerebellar stimulation were found in 10 different controlled experiments in 5 different monkeys with chronic alumina-induced psychomotor seizures. The stimulation parameters used were comparable to those used in human epileptics, and continuous daily EEG and behavioral monitoring allowed all seizures to be measured for daily frequency and duration over the several weeks of the experiments. Nocturnal seizures were similarly quantified in 3 monkeys to verify that cerebellar stimulation did not affect them. Motor cortex potentials evoked by cerebellar pulses confirmed that the stimulations were activating the cerebellum throughout the experiments, and measures of electrode access resistance and impedance verified that the electrodes remained in contact with the cerebellum. In one monkey given phenobarbital medication, interictal morbid behavior appeared to be improved by chronic stimulation of either cerebellum or dorsolateral frontal cortex, thus indicating an arousal influence of brain stimulation not due to cerebellum per se.     

Quantitative nano-mechanical mapping AFM-based method for elastic modulus and surface roughness measurements of model polymer infiltrated ceramics

ObjectivesThe aim of this in vitro investigation was to assess and compare surface characteristics and nanomechanics of model polymer infiltrated ceramic network (PICN) materials compared to CAD/CAM resin composite blocks.Material and methodsFour model PICN materials sintered at different temperatures (Exp.125, Exp.130, Exp.135 and Exp.155) were investigated along with three CAD/CAM resin composites; Lava Ultimate (LU), Cerasmart (CS) and Grandio Bloc (GB), and one commercial PICN block - Vita Enamic (VE). Forty samples were prepared with dimensions of 14 × 12 × 2 mm for resin ceramic and VE blocks and 15 × 2 mm discs for model PICN materials. All samples were scanned using atomic force microscopy (AFM) (n = 3) at multiple locations and two different scan sizes (20 ×20 µm and 3 ×3 µm). Surface optical gloss (n = 5) at 60° was also determined for all the groups. Data were analysed using one-way ANOVA, and Tukey’s post hoc test (α = 0.05).ResultsResin composite blocks showed smoother surfaces compared to the PICN materials. The average surface roughness values (Ra) ranged from 7.75 nm to 31.21 nm and the gloss value ranged from 56.43 GU to 91.81 GU. The highest surface roughness value was found for Exp.125 (31.21 nm) while LU showed the lowest roughness value (7.75 nm) (the difference being statistically significant: p = 0.001). Variation was noticed in terms of nanomechanical mapping within and between the groups. Images generated from the elastic modulus map values clearly indicated that all PICN materials had more than one phase and very different components.ConclusionsCAD/CAM resin composite blocks exhibited higher gloss and lower roughness values compared to PICN materials. However, both the commercial and model PICN materials showed more stiffness than resin composite with the presence of at least two different phases. Sintering temperature appears to have a significant effect on material topography and nanomechanical properties. The model PICN sintered at 1550 °C showed a comparable range of elastic modulus values to those of enamel.     

人凝血因子Ⅷ提取工艺优化研究

目的：优化血浆中人凝血因子Ⅷ提取工艺条件。方法以人血浆冷沉淀为原料,人凝血因子Ⅷ的比活性回收率作为评价指标,采用单因素试验,对铝胶的加量,铝胶吸附时的pH值、酸沉淀时的pH值等进行研究,优选提取工艺。结果加入冷沉淀重量12%的铝胶,并将pH值调节至7.1进行吸附,上清液中人凝血因子Ⅷ比活性可达9.50IU/mg,酸沉淀时将pH值调节至6.3,离心上清夜中人凝血因子Ⅷ比活性为11.50 IU/mg。经过以上两步处理,可将人凝血因子Ⅷ比活性提高近2倍。结论人凝血因子Ⅷ提取工艺优化研究工艺合理、可行,能有效达到纯化提取人凝血因子Ⅷ的效果。