Evaluation of Fracture Strength of Ceramics Containing Small Surface Defects Introduced by Focused Ion Beam.

The aim of this study was to clarify the effects of micro surface defects introduced by the focused ion beam (FIB) technique on the fracture strength of ceramics. Three-point bending tests on alumina-silicon carbide (Al2O3/SiC) ceramic composites containing crack-like surface defects introduced by FIB were carried out. A surface defect with area in the range 19 to 35 µm was introduced at the center of each specimen. Test results showed that the fracture strengths of the FIB-defect specimens depended on area. The test results were evaluated using the evaluation equation of fracture strength based on the process zone size failure criterion and the area parameter model. The experimental results indicate that FIB-induced defects can be used as small initial cracks for the fracture strength evaluation of ceramics. Moreover, the proposed equation was useful for the fracture strength evaluation of ceramics containing micro surface defects introduced by FIB.

[Analgesia with paravertebral block for postoperative pain after thoracic or thoracoabdominal aortic aneurysm repair].

Paraplegia is a serious complication after thoracoabdominal aortic aneurysm repair. Therefore, maintenance of spinal cord perfusion pressure, drainage of cerebrospinal fluid, and avoidance of opioids are important for prevention of paraplegia Management of acute post-thoracotomy pain is necessary not only to keep the patient comfortable but also to minimize postoperative complications. However, epidural analgesia, a common method of pain control, is hard to use because of existing postoperative coagulopathy and avoidance of spinal cord ischemia Although both paravertebral block and epidural analgesia provide comparable pain relief after thoracic surgery, paravertebral block has lesser detrimental effects on spinal cord perfusion and better preserves the possibility to monitor neurologic function than epidural analgesia. We report 7 cases in which paravertebral blockade was used for analgesia in patients who underwent thoracoabdominal aneurysm repair.

Administration of chinpi, a component of the herbal medicine ninjin-youei-to, reverses age-induced demyelination.

The disruption of myelin causes severe neurological diseases. An understanding of the mechanism of myelination and remyelination is essential for the development of therapeutic strategies for demyelination diseases. Our previous findings indicated that the FcRγ/Fyn cascade is a potential therapeutic target for remyelination caused by the Chinese/Japanese traditional herbal (Kampo) medicine ninjin'youeito (Ninjin-youei-to, NYT), which is a hot-water extract made from 12 medicinal herbs. To identify which constituents of NYT are involved in the reversal of demyelination and to examine the potential therapeutic effect, we tested several of the chemical constituents of NYT. Here, we report that Chinpi, a constituent of NYT, upregulates the FcRγ/Fyn signaling cascade resulting in a potentially therapeutic effect against age-induced demyelination. In addition, we observed that phosphorylated (activated) FcRγ/Fyn upregulated the expression of the 21.5 kDa isoform of myelin basic protein, inducing rapid morphological differentiation, when oligodendrocyte precursor cells (OPCs) were cultured in the presence of hesperidin and/or narirutin (the major active constituents of Chinpi). These results suggest that hesperidin and narirutin participate in the FcRγ/Fyn signaling pathway in OPCs causing these cells to differentiate into myelinating oligodendrocytes.

Identification of genes differentially expressed in mouse fetuses from streptozotocin-induced diabetic pregnancy by cDNA subtraction.

Epidemiological studies have shown that the risks of fetal malformation such as neural tube defects increase in diabetic pregnancy. To explore the mechanism of fetal malformation induced by diabetes, cDNA subtraction using mouse embryos (E9.5) of diabetic dams and those of controls was performed to identify differentially expressed genes. The expression level of genes identified by cDNA subtraction was further verified by quantitative RT-PCR using E8.5 embryos, and differential expression of 4 genes, Brcc3, Commd3, Ddx1, and SET was confirmed. We also analyzed the expression level of neural tube defect-related genes, and found that Folbp1, EphrinA5 and Sox10 were differentially expressed. Altered expression of these genes mostly persisted throughout the later stages of the development (E10.5-14.5). Hierarchical clustering analysis showed correlation between expression levels of these genes, suggesting that these genes cooperatively play a role in embryonic development. Our results suggest that an altered gene expression profile in embryos underlies the development of congenital malformation in diabetic pregnancies.