Capsiate is a nonpungent capsaicin analog, a recently identified principle of the nonpungent red pepper cultivar CH-19 Sweet. In the present study, we report that 2-wk treatment of capsiate increased metabolic rate and promoted fat oxidation at rest, suggesting that capsiate may prevent obesity. To explain these effects, at least in part, we examined uncoupling proteins (UCPs) and thyroid hormones. UCPs and thyroid hormones play important roles in energy expenditure, the maintenance of body weight, and thermoregulation. Two-week treatment of capsiate increased the levels of UCP1 protein and mRNA in brown adipose tissue and UCP2 mRNA in white adipose tissue. This dose of capsiate did not change serum triiodothyronine or thyroxine levels. A single dose of capsiate temporarily raised both UCP1 mRNA in brown adipose tissue and UCP3 mRNA in skeletal muscle. These results suggest that UCP1 and UCP2 may contribute to the promotion of energy metabolism by capsiate, but that thyroid hormones do not.
Ultra-wide bandgap p-type α-(Ir,Ga)2O3 films with bandgaps of up to 4.3 eV have been obtained by unintentional doping or Mg doping. For Mg-doped films, Hall-effect measurements revealed a hole concentration of 9.9 × 1018 to 8.1 × 1019 cm−3 and a mobility of 0.13 − 0.92 cm2/V s, respectively. A preliminary test of a pn junction diode composed of p-type α-(Ir,Ga)2O3 and n-type α-Ga2O3 did not show catastrophic breakdown in the reverse direction until 100 V and the current on/off ratio at +3 V/−3V was 5 × 105. Since α-(Ir,Ga)2O3 and α-Ga2O3 take the same crystal structure and are well lattice-matched (with a lattice mismatch of <0.3%), the formation of a high-quality pn heterojunction is encouraged; this is one of the advantages of the corundum material system.
Iodine is a useful n-type dopant for CdTe and HgCdTe layers grown by metal-organic vapor phase epitaxy (MOVPE) and molecular beam epitaxy because iodine is expected to have a lower diffusion coefficient compared to group III elements. 1-6 For MOVPE, ethyliodine (EI) is an especially important iodine source because EI has a higher vapor pressure than isopropyliodine and group III metal-organic dopant sources. This enables the achievement of excellent controllability of doping over a wide range without suffering the problem of memory effect. 5 We have studied the iodine doping of CdTe layers grown on GaAs substrates. However, the maximum electron density of as-grown layers has been limited to around 10 17 cm Ϫ3 . The doping condition to obtain higher electron density has not yet been clarified. The n-type CdTe layers with high electron density and low resistivity are considered to be useful for applications in not only infrared detectors but also x-ray and ␥-ray detectors and solar cells.In this paper, we report the doping characteristics of iodine in CdTe layers grown by MOVPE using dimethylcadmium (DMCd), diethyltelluride (DETe), and diisopropyltelluride (DiPTe) as precursors. Doping characteristics were studied using EI in a wide range of growth conditions. Higher electron densities were obtained for layers grown with DETe than those grown with DiPTe. A doping condition for layers with a high electron density of 2.8 ϫ 10 18 cm Ϫ3 was also obtained with DETe. Mechanisms for different doping characteristics between DETe and DiPTe were studied on the basis of observed growth characteristics for these precursors.Iodine doping of CdTe layers grown on (100) GaAs by metal-organic vapor phase epitaxy (MOVPE) was studied using diethyltelluride (DETe) and diisopropyltelluride (DiPTe) as tellurium precursors and ethyliodine (EI) as a dopant. Electron densities of doped layers increased gradually with decreasing the growth temperature from 425°C to 325°C. Doped layers grown with DETe had higher electron densities than those grown with DiPTe. When the hot-wall temperature was increased from 200°C to 250°C at the growth temperature of 325°C, doped layers grown with DETe showed an increase of the electron density from 3.7 ϫ 10 16 cm Ϫ3 to 2.6 ϫ 10 18 cm Ϫ3 . On the other hand, such an increase of the electron density was not observed for layers grown with DiPTe. The mechanisms for different doping properties for DETe and DiPTe were studied on the basis of the growth characteristics for these precursors. Higher thermal stability of DETe than that of DiPTe was considered to cause the difference of doping properties. With increasing the hot-wall temperature from 200°C to 250°C, the effective ratio of Cd to Te species on the growth surface became larger for layers grown with DETe than those grown with DiPTe. This was considered to decrease the compensation of doped iodine and to increase the electron density of layers grown with DETe. The effective ratio of Cd to Te species on the growth surface also increased with decreasing grow...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.