Search

Postmenopausal osteoporosis and dyslipidemia are well-known skeletal and metabolic changes in middle-aged women. We investigated the effects of combined treatments with a selective estrogen receptor modulator (SERM) and exercise on bone and fat parameters in ovariectomized (OVX) rats. Sixteen-week-old female Sprague–Dawley rats underwent bilateral ovariectomy, and rats were randomized to BZA (bazedoxifene at 0.3 mg/kg/day), Exe (treadmill exercise at 12–15 m/min, 60 min/day, 5 days/week), Comb (BZA and Exe), and Cont (control treated with vehicle and no exercise) groups 8 weeks after ovariectomy. After 4 or 8 weeks of treatment, bone mineral density (BMD) of the total femur and lumbar spine and whole-body percentage fat mass were determined by dual-energy X-ray absorptiometry, and mechanical testing of the femoral shaft, and bone and fat histomorphometric analyses of the proximal tibia were performed. Treadmill exercise had decreased bone marrow adipocytes from 4 weeks of treatment and whole-body percentage fat mass at 8 weeks. BZA increased BMD at the lumbar spine and decreased the whole-body percentage fat mass from 4 weeks and bone marrow adipocytes at 8 weeks. Combination therapy increased BMD for the lumbar spine and decreased bone marrow adipocytes and whole-body percentage fat mass from 4 weeks. Combination therapy with BZA and exercise appears effective to improve bone and fat parameters in OVX rats.

Soft tissue sarcoma (STS) mainly occurs in middle-aged and senior citizens. Although a poorer prognosis has been reported for older patients, few studies have examined advanced elderly excessive older patients. We evaluated the clinical features of advanced elderly patients with STS. One hundred and forty-four patients were included in this retrospective study, and we divided them into two groups based on a cut-off age of 85 (older and younger groups). The patients’ information, including age, tumor type, location, size, presence of metastasis, AJCC stage, FNCLCC classification, treatment-related factors, local and distant relapse, and outcome, was collected. We compared the clinical courses between the 2 groups. In all patients, the frequency of chemotherapy in the older group was significantly lower than in the younger group (P

A novel method to fabricate uniform epitaxial graphene on C-face SiC substrates was investigated. Graphene was grown on the C-face 6H-SiC substrates with a sputtered SiC film by annealing temperatures ranging from 1400 to 1900 °C under an Ar ambient. The fractional area of the graphene having the layer number of two was about 95% in a 75×75 μm square by a Raman mapping and a low energy electron microscopy. Graphene on the C-face SiC fabricated by this method is quite uniform compared to that made by a conventional method without the sputtered SiC films and is thus suitable for high frequency analog devices.

Vertical DMOSFET devices with sizes from single cell to 3x3 mm2 large devices have been fabricated on cubic 3C-SiC material. The used 3C-SiC substrates had varying material quality. The best quality had a more than 2 orders of magnitude lower density of extended crystal defects than the worst material. The processed and investigated vertical DMOSFET devices were designed for 600 V blocking voltage and had hexagonal unit cells with 2 μm channel length and aluminum implanted termination rings. The p-body was aluminum implanted and the source was phosphorus implanted. As deposited Ti/W contacts were evaluated as source and drain metallization. Single cell vertical DMOSFET devices, processed on the low defect density material quality, gave voltage blocking capabilities of more than 600 V with leakage currents of 0.1 to 10 μA. The same devices could handle currents around 5 mA in on-state at 15 V gate bias. MOSFET devices with 50 to 100 unit cells had blocking voltages of 400 to 500 V with on-state currents of 0.2 to 0.4 A at 15 V gate bias, indicating the potential of 3C-SiC for the fabrication of next generation power MOSFET devices.

Ni Schottky-diodes (SDs) 300 μm in diameter were fabricated by thermal evaporation using contact lithography on cubic GaN and AlxGa1-xN epilayers. Phase-pure cubic GaN and c-Al0.3Ga0.7N/GaN structures were grown by plasma assisted molecular beam epitaxy (MBE) on 200 µm thick free-standing 3C-SiC (100) substrates. The quality of the cubic group III-nitride epilayers was checked by high resolution X-ray diffractometry, atomic force microscopy and photoluminescence at room temperature and at 2 K. Large deviations from the thermionic emission transport were observed in the current voltage (I-V) behavior of these SDs. Detailed analysis of the I-V characteristics at 300 K and at low temperature showed that a thin surface barrier is formed at the Ni semiconductor interface. Thermal annealing in air at 200°C alters the composition of this thin surface barrier and reduces the leakage current by three orders of magnitude. The doping density dependence of breakdown voltages derived from the reverse breakdown voltage characteristics of c-GaN SDs is in good agreement with theoretically calculated values and follows the expected trend. From these experimental data a blocking voltage of higher than 600V is extrapolated for c-GaN films with a doping level of ND = 5×1015 cm-3.

The Hall scattering factor of holes rH,h(T) in 4H- and 6H-SiC is determined by comparing the temperature-dependent free hole concentration p(1/T) obtained from Hall effect and from the neutrality equation with defect parameters, which are independently determined by SIMS and C-V measurements. rH,h(T) strongly deviates from 1 and assumes values between 1.4 and 0.5 at temperatures ranging from 100K to 800K. rH,h(T) is identical for 4H-and 6H-SiC within the measurement uncertainty. Al-doped SiC epilayers of the 3C-, 4H- and 6H-polytype were investigated with admittance spectroscopy and DLTS prior to and subsequent to processing steps. Depending on the SiC polytype, a different number of shallow acceptors is observed, which are thermally stable up to high temperatures (1700°C).

A novel technique to reduce planar defects in 3C-SiC is to grow it on “undulant-Si” substrates, on which the surface forms countered slopes oriented in the [110] and [110] directions. In the initial stage of 3C-SiC growth, step flow epitaxy occurs on each slope of the substrate, reducing the anti-phase boundaries. Then, the stacking faults in the (111) and (111) planes are gradually annihilated by combining with counter-stacking faults, while those parallel to (111) and (111) vanish. The freestanding 3C-SiC exhibits anisotropy in its electrical properties. The origin of the anisotropy in electrical properties is discussed by referring to the results of X-ray diffraction study.

Many properties of LPCVD SiC film as X-ray mask membrane have been investigated in detail. The film has an atomic ratio of 1.0 and negligible impurities, and was found to be damage-free to SR X-rays up to 500 KJ/cm2. An integrated transparency of 1.05 μm thick SiC membrane for SR X-rays was measured to be 76%. The interference peak at 633 nm of optical spectrum has given the membrane of around 1.0 μm in thickness the transmittance peak of 70% and increased to more than 80% after an AR coating or planarizations by polishing and etching-back. The attainable transmittance was found to be limited to about 84%, theoretically and experimentally, due to the absorption of the membrane. The peak transmittance of 87% is obtainable by the AR coating on the polished SiC membrane. The internal stress was found to be independent of thicknesses above 0.6 μm and the measured Young's modulus is 4.5×1011 Pa irrespective of the thickness and stress. Some extremely polished (0.1 nm Ra) and all the etched-back membranes studied withstood breakage at the pressure as high as the as-deposited ones. The stress uniformity in 30 mm square of the membrane was found to be ± 10 % by measuring five local stresses with a bulge method.