28,867 research outputs found
Transfer of Gravitational Information through a Quantum Channel
Gravitational information is incorporated into an atomic state by correlation
of the internal and external degrees of freedom of the atom, in the present
study of the atomic interferometer. Thus it is difficult to transfer
information by using a standard teleportation scheme. In this paper, we propose
a novel scheme for the transfer of gravitational information through a quantum
channel provided by the entangled atomic state. Significantly, the existence of
a quantum channel suppresses phase noise, improving the sensitivity of the
atomic interferometer. Thus our proposal provides novel readout mechanism for
the interferometer with an improved signal-to-noise ratio
Shear Viscosity from the Effective Coupling of Gravitons
We review the progress in the holographic calculation of shear viscosity for
strongly coupled field theories. We focus on the calculation of shear viscosity
from the effective coupling of transverse gravitons and present some explicit
examples.Comment: 10 pages, invited presentation for the 9th Asia-Pacific International
Conference On Gravitation And Astrophysics (ICGA 9), June 28-July 2, 2009,
Wuhan, China; for the proceedings to be published by World Scientifi
Protective effect of Rhizoma drynariae extract on osteoporosis in ovariectomized rat model
Purpose: To investigate the therapeutic effect of Rhizoma Drynariae extract (RDE) on ovariectomyinduced osteoporosis in rats.Methods: Female Sprague-Dawley rats were randomly assigned to a sham-operated group (control) and five ovariectomy (OVX) subgroups: OVX with vehicle (OVX), OVX with 17ß-estradiol (E2, 25 μg/kg/day), and OVX with RDE doses (40, 80, and 160 mg/kg/day). Daily oral administration of E2 or RDE started 4 weeks after OVX and lasted for 16 weeks. The bone mineral density (BMD) of the L4 vertebrae and right femurs was estimated. The length of each femur was measured with a micrometer gauge, and the center of the diaphysis determined. Three representatives L4 vertebrae were selected to evaluate the trabecular microarchitecture. Serum alkaline phosphatase (ALP), urinary calcium (U-Ca),urinary phosphorus (U-P), urinary creatinine (Cr) and osteocalcin (OC) levels were measured.Results: The study showed that high-dose of RDE significantly inhibited the bone mineral density (BMD) reduction of L4 vertebrae (0.20 ± 0.02 g/cm3, p < 0.05) and femurs (0.18 ± 0.02 g/cm3, p < 0.05) caused by OVX and prevented the deterioration of trabecular microarchitecture (p < 0.05), which were accompanied by a significant decrease in skeletal remodeling (p < 0.05) as evidenced by the lowerlevels of bone turnover markers. High-dose of RDE improved morphometric parameters, namely, Tb-N (3.8 ± 0.2 mm, p < 0.05), Tb-Th (0.083 ± 0.011 mm, p < 0.05) and Tb-Sp (0.19 ± 0.01 mm, p < 0.05) in L4 vertebrae significantly. The present study indicates that the administration of RDE at higher doses over a 16-week period can prevent OVX-induced osteoporosis in rats without hyperplastic effects on the uterus.Conclusion: Thus, RDE is a potential natural alternative for postmenopausal osteoporosis treatment in elderly women.Keywords: Rhizoma Drynariae, Postmenopausal osteoporosis, Ovariectomy, Bone mineral density, Morphometri
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