980 research outputs found
Quasicentral modulus and self-similar sets: a supplementary result to Voiculescu's work
In his recent work, Voiculescu generalized his remarkable formula for the
quasicentral modulus of a commuting -tuple of hermitian operators with
respect to the -Lorentz ideal to the case where its spectrum is
contained in a Cantor-like self-similar set in a certain class. In this note,
we treat general self-similar sets satisfying the open set condition, and
obtain lower and upper bounds of the quasicentral modulus. Our proof shows that
Voiculescu's formula holds for a class of self-similar sets including the
Sierpinski gasket and the Sierpinski carpet.Comment: Condition (A1) is relaxed, and Remark 1 and the proof of Lemma 3.4
are changed. Minor corrections.To appear in Integral Equations and Operator
Theor
Production of overdense plasmas by launching 2,45 GHz electron cyclotron waves in a helical device
For production of low temperature plasmas with low collisionality, 2.45GHz
microwave power up to 20kW is injected perpendicularly to the toroidal field at
very low toroidal field BtComment: 12th International Congress on Plasma Physics, 25-29 October 2004,
Nice (France
Caffeic acid inhibits the formation of 1-hydroxyethyl radical in the reaction mixture of rat liver microsomes with ethanol partly through its metal chelating activity
Effect of caffeic acid on the formation of 1-hydroxyethyl radicals via the microsomal ethanol-oxidizing system pathway was examined. The electron spin resonance spin trapping showed that 1-hydroxyethyl radicals form in the control reaction mixture which contained 0.17 M ethanol, 1 mg protein/ml rat river microsomes, 0.1 M α-(4-pyridyl-1-oxide)-N-tert-butylnitrone, 5 mM nicotinamide adenine dinucleotide phosphate and 30 mM phosphate buffer (pH 7.4). When the electron spin resonance spectra of the control reaction mixtures with caffeic acid were measured, caffeic acid inhibited the formation of 1-hydroxyethyl radicals in a concentration dependent manner. Gallic acid, dopamine, l-dopa, chlorogenic acid and catechin also inhibited the formation of 1-hydroxyethyl radicals. Above results indicated that the catechol moiety is essential to the inhibitory effect. Caffeic acid seems to chelate of iron ion at the catechol moiety. Indeed, the inhibitory effect by caffeic acid was greatly diminished in the presence of desferrioxamine, a potent iron chelator which removes iron ion in the Fe (III)-caffeic acid complex. Since Fe (III)-desferrioxamine complex is active for the 1-hydroxyethyl radicals formation, caffeic acid inhibits the formation of 1-hydroxyethyl radicals in the reaction mixture partly through its metal chelating activity
Effects of Nutritional Support Combined with Neuromuscular Electrical Stimulation on Muscle Strength and Thickness: A Randomized Controlled Trial in Healthy Young Adult Males
In the management of post-injury patients with activity limitations, methods to prevent musculoskeletal disorders and hasten recovery are important. This randomized controlled, single-blinded study was a preliminary investigation of the combined effect of nutritional support with neuromuscular electrical stimulation (NMES) on muscle strength and thickness. Healthy young adult males (median age, 21 years) were enrolled; each of their hands was randomly assigned to one of the following four groups: Placebo, Nutrition, NMES, and Nutrition + NMES. All participants received whey protein or placebo (3x/week for 6 weeks) and NMES training (3x/week for 6 weeks) on the abductor digiti minimi (ADM) muscle of either the left or right hand. ADM muscle strength and thickness were analyzed at baseline and at week 7. We analyzed 38 hands (9 Placebo, 10 Nutrition, 9 NMES, 10 Nutrition + NMES). There was significantly greater muscle strengthening in the Nutrition + NMES group compared to the Placebo group or the NMES group, but no significant difference in gain of muscle thickness. The combined intervention may be effective in improving muscle strength. Future clinical trials targeting various muscles after sports-related injuries are warranted
Two-Fermi-surface superconducting state and a nodal d-wave gap in the electron-doped Sm(1.85)Ce(0.15)CuO(4-d) cuprate superconductor
We report on laser-excited angle-resolved photoemission spectroscopy (ARPES)
in the electron-doped cuprate Sm(1.85)Ce(0.15)CuO(4-d). The data show the
existence of a nodal hole-pocket Fermi-surface both in the normal and
superconducting states. We prove that its origin is long-range
antiferromagnetism by an analysis of the coherence factors in the main and
folded bands. This coexistence of long-range antiferromagnetism and
superconductivity implies that electron-doped cuprates are two-Fermi-surface
superconductors. The measured superconducting gap in the nodal hole-pocket is
compatible with a d-wave symmetry.Comment: 4 pages, 3 figures, accepted to Phys. Rev. Let
Design of Hemispherical Radio Frequency (RF) Capacitive-type Electrode Free of Edge Effects for Treatment of Intracavitary Tumors
A new hemispherical electrode to heat oral cavity cancer is proposed. The electrode does not produce a hot spot around its edge, a feature that usually arises when using radio frequency (RF) capacitive-type heating. The hemispherical electrode was designed by computer simulation using a 3-D finite element method. To assess its practicality and effectiveness, we built a prototype hemispherical electrode
and evaluated its heating characteristics by phantom experiments. The heating effects on the phantom were measured by thermography. The concave phantom surface in contact with the hemispherical
electrode showed a uniform increase in temperature, with no obvious edge effect. The proposed
electrode allows non-invasive RF capacitive-type heating for intracavity tumors that was not previously considered possible, and should contribute to the multidisciplinary treatment of intracavity tumors
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