ABSTRACT
Coenzyme Q(10) (CoQ(10)) has been widely commercially available in Japan as a dietary and health supplement since 2001 and is used for the prevention of lifestyle-related diseases induced by free radicals and aging. We evaluated CoQ(10) supplements to ensure that these supplements can be used effectively and safely. Commercially available products were selected and assessed by the quality control tests specified in the Japanese Pharmacopoeia XV. When the disintegration time of CoQ(10) supplements was measured, a few tested supplements did not completely disintegrate even after incubation in water for an hour at 37 degrees C. In the content test, many samples were well controlled. However, a few supplements showed low recovery rates of CoQ(10) as compared to manufacturer's indicated contents. Among soft capsule and liquid supplements, the reduced form of CoQ(10) (H(2)CoQ(10)), as well as the oxidized form, was detected by HPLC with electrochemical detector. The results for experimental formulated CoQ(10) supplements demonstrated that H(2)CoQ(10) was produced by the interaction of CoQ(10) with vitamins E and/or C. From these results, we concluded that quality varied considerably among the many supplement brands containing CoQ(10). Additionally, we also demonstrated that H(2)CoQ(10) can be detected in some foods as well as in CoQ(10) supplements.
ABSTRACT
A single-shot optical pump-and-probe test system is reported. The system is designed for thermal characterization of thin-film samples that can change their phase state under the influence of a short and intense laser pulse on a subnanosecond time scale. In combination with numerical analysis, the system can be used to estimate thermal constants of thin films, such as specific heat and thermal conductivity. In-plane and out-of plane thermal conductivity can be estimated independently. The system is intended for use in research on optical data storage and material processing with pulsed laser light. The system design issues are discussed. As application examples, we report on using the system to study thermal dynamics in two different thin-film samples: a gold film on a glass substrate (a single-phase system) and the quadrilayer phase-change stack typical in optical data-storage applications.
ABSTRACT
We have already shown that prolonged supplementation of CoQ(10) in humans reduces the wrinkle area rate and wrinkle volume per unit area in the corner of the eye. CoQ(10) supplementation is known to increase the CoQ(10) level in serum and in many organs; however, the level of CoQ(10) in skin has not yet been fully investigated yet. We examined whether CoQ(10) intake elevates the CoQ(10) and CoQ(9) levels in epidermis, dermis, serum and other organs (kidney, heart, brain, muscle and crystalline lens) in 43-week-old hairless male mice. We also established a method using a high performance liquid chromatograph equipped with an electrochemical detector (HPLC-ECD) to simultaneously quantify CoQ(9) and CoQ(10) in the tissues. CoQ(10) (0, 1, 100 mg/kg p.o.) was administered daily for 2 weeks. CoQ(10) supplementation of 100 mg/kg increased the serum and epidermal CoQ(10) levels significantly, but did not increase the CoQ(10) levels in either dermis or other organs. In conclusion, we showed that CoQ(10) intake elevates the epidermal CoQ(10) level, which may be a prerequisite to the reduction of wrinkles and other benefits related to the potent antioxidant and energizing effects of CoQ(10) in skin.
Subject(s)
Epidermis/chemistry , Ubiquinone/analogs & derivatives , Administration, Oral , Animals , Coenzymes , Epidermis/drug effects , Male , Mice , Mice, Hairless , Tissue Distribution , Ubiquinone/administration & dosage , Ubiquinone/metabolism , Ubiquinone/pharmacologyABSTRACT
We investigated the variations in reflectivity during the phase transition between amorphous and crystalline states of a Bi-doped GeTe-Sb2Te3 pseudobinary compound film with subnanosecond laser pulses, using a pump-and-probe technique. We also used a two-laser static tester to estimate the onset time of crystallization under 2.0-micros pulse excitation. Experimental results indicate that the formation of a melt-quenched amorphous mark is completed in approximately 1 ns, but that crystalline mark formation on an as-deposited amorphous region requires several hundred nanoseconds. Simple arguments based on heat diffusion are used to explain the time scale of amorphization and the threshold for creation of a burned-out hole in the phase-change film.
