Abstract. Flow-mediated vasodilatation (FMD) is a vascular functional test to detect endothelial dysfunction at the early stage of cardiovascular diseases. Patients with active acromegaly have higher morbidity and mortality due to cardiovascular events. To determine whether active acromegaly is associated with endothelial dysfunction, we studied 17 patients with active acromegaly for measurements of FMD, carotid intima-media thickness (IMT) and brachial-ankle pulse wave velocity (baPWV), and other biochemical parameters before and 3 months after transsphenoidal surgery (TSS). Baseline %FMD in patients with active acromegaly was significantly lower than that in age-and sex-matched control subjects. After TSS, the mean %FMD in acromegaly significantly increased from 5.3% to 7.4%; 12 patients had increased %FMD (responders), whereas 5 patients had decreased or unchanged %FMD (non-responders). However, neither carotid IMT nor baPWV changed after TSS. Serum levels of GH, insulin-like growth factor (IGF)-1, total cholesterol, lowdensity lipoprotein cholesterol (LDL-C), hemoglobin HA1C, fasting plasma glucose and insulin levels, and homeostasis model assessment (HOMA)-R significantly decreased, whereas high-density lipoprotein cholesterol significantly increased. Responders had significantly lower baseline %FMD than did non-responders and both insulin levels and HOMA-R significantly decreased in responders, but not in non-responders after TSS. Simple regression analysis revealed that the change of %FMD showed a significant negative correlation with that of LDL-C, but not of IGF-1 or GH, in responders. In conclusion, it is suggested that endothelial dysfunction associated with active acromegaly improves soon after TSS, which is related to LDL-C and/or insulin resistance, but not to excess GH and/or IGF-1 itself.

High-density dislocations are formed in silicon by a femtosecond-laser-driven shock wave. The silicon is hardened to around 6.4 times harder than the matrix material as measured by micro-indentation hardness test using nanoindentation. Because the depth, size, and inhomogeneity of the area where the high-density dislocations exist are the same as those of the hardened area, we conclude that the hardening is caused by the high density of dislocations. We suggest that the femtosecond laser shock compression plays an important role in creating high-energy-density states in materials. #

No abstract

High-pressure phases which are β-Sn, Imma and simple hexagonal structures of silicon are quenched using an intense femtosecond laser-driven shock wave. These high-pressure phases have never synthesized in ambient pressure by hydrostatic and conventional shock compression methods. Femtosecond laser was irradiated to single crystal-silicon with no-dopant. We confirmed the existence of these high pressure phases by analyzing the crystalline structure of the femtosecond laser irradiated silicon using grazing incidence synchrotron x-ray diffraction.