6,118 research outputs found
Quantum Fluid Dynamics Approach to Time-Dependent electronic State Problems in Surface Systems
Dynamical properties associated with the electron motion at sufaces are discussed by solving the time-dependent Schrodinger equation based on the quantum fluid dynamics(QFD) scheme. The classical description for the quantum system provides us clear physical picture such as the eletron tunneling, migration, effects of external field. Two dimensional model studies of the electron current are presented at W(001) surface
Ki-Energy (Life-Energy) Protects Isolated Rat Liver Mitochondria from Oxidative Injury
We investigated whether ‘Ki-energy’ (life-energy) has beneficial effects on mitochondria. The paradigm we developed was to keep isolated rat liver mitochondria in conditions in which they undergo heat deterioration (39°C for 10 min). After the heat treatment, the respiration of the mitochondria was measured using a Clarke-type oxygen electrode. Then, the respiratory control ratio (RC ratio; the ratio between State-3 and State-4 respiration, which is known to represent the integrity and intactness of isolated mitochondria) was calculated. Without the heat treatment, the RC ratio was >5 for NADH-linked respiration (with glutamate plus malate as substrates). The RC ratio decreased to 1.86–4.36 by the incubation at 39°C for 10 min. However, when Ki-energy was applied by a Japanese Ki-expert during the heat treatment, the ratio was improved to 2.24–5.23. We used five preparations from five different rats, and the significance of the differences of each experiment was either P < 0.05 or P < 0.01 (n = 3–5). We analyzed the degree of lipid peroxidation in the mitochondria by measuring the amount of TBARS (thiobarbituric acid reactive substances). The amount of TBARS in heat-treated, no Ki-exposed mitochondria was greater than that of the control (no heat-treated, no Ki-exposed). However, the amount was reduced in the heat-treated, Ki-exposed mitochondria (two experiments; both P < 0.05) suggesting that Ki-energy protected mitochondria from oxidative stress. Calcium ions may play an important role in the protection by Ki-energy. Data also suggest that the observed Ki-effect involves, at least, near-infrared radiation (0.8–2.7 μm) from the human body
Three-body structure of the system with coupling
The structure of the three-body system, which has been observed
recently by the HypHI collaboration, is investigated taking coupling explicitly into account. The and interactions employed in
this work reproduce the binding energies of H, H
and He. We do not find any bound state, which
contradicts the interpretation of the data reported by the HypHI collaboration.Comment: To be publsihed in PRC as a Rapid communicatio
Design of a Broadband Amplifier for High Speed Applications
This paper provides comprehensive insight into the design approach followed for an amplifier dedicated to high speed base band signals. To demonstrate the methodology, an amplifier consisting of nine PHEMT cascode cells within a distributed amplifier topology was designed. The resulting frequency response is 40 GHz at the 3-dB point, and the output voltage for a 43 Gbps eye diagram is 7.3 Vpp at the chip terminal
Symmetry breaking and other phenomena in the optimization of eigenvalues for composite membranes
We consider the following eigenvalue optimization problem: Given a bounded
domain and numbers , ,
find a subset of area for which the first Dirichlet
eigenvalue of the operator is as small as possible.
We prove existence of solutions and investigate their qualitative properties.
For example, we show that for some symmetric domains (thin annuli and dumbbells
with narrow handle) optimal solutions must possess fewer symmetries than
; on the other hand, for convex reflection symmetries are
preserved.
Also, we present numerical results and formulate some conjectures suggested
by them.Comment: 24 pages; 3 figures (as separate files); (shortened previous
version); to appear in Comm. Math. Phy
Studying Diquark Structure of Heavy Baryons in Relativistic Heavy Ion Collisions
We propose the enhancement of yield in heavy ion collisions at
RHIC and LHC as a novel signal for the existence of diquarks in the strongly
coupled quark-gluon plasma produced in these collisions as well as in the
. Assuming that stable bound diquarks can exist in the quark-gluon
plasma, we argue that the yield of would be increased by two-body
collisions between diquarks and quarks, in addition to normal
three-body collisions among , and quarks. A quantitative study of
this effect based on the coalescence model shows that including the
contribution of diquarks to production indeed leads to a
substantial enhancement of the ratio in heavy ion collisions.Comment: Prepared for Chiral Symmetry in Hadron and Nuclear Physics
(Chiral07), Nov. 13-16, 2007, Osaka, Japa
Five Decades of Research on Mitochondrial NADH-quinone Oxidoreductase (complex I)
NADH-quinone oxidoreductase (complex I) is the largest and most complicated enzyme complex of the mitochondrial respiratory chain. It is the entry site into the respiratory chain for most of the reducing equivalents generated during metabolism, coupling electron transfer from NADH to quinone to proton translocation, which in turn drives ATP synthesis. Dysfunction of complex I is associated with neurodegenerative diseases such as Parkinson’s and Alzheimer’s, and it is proposed to be involved in aging. Complex I has one non-covalently bound FMN, eight to 10 iron-sulfur clusters, and protein-associated quinone molecules as electron transport components. Electron paramagnetic resonance (EPR) has previously been the most informative technique, especially in membrane in situ analysis. The structure of complex 1 has now been resolved from a number of species, but the mechanisms by which electron transfer is coupled to transmembrane proton pumping remains unresolved. Ubiquinone-10, the terminal electron acceptor of complex I, is detectable by EPR in its one electron reduced, semiquinone (SQ) state. In the aerobic steady state of respiration the semi-ubiquinone anion has been observed and studied in detail. Two distinct protein-associated fast and slow relaxing, SQ signals have been resolved which were designated SQNf and SQNs. This review covers a five decade personal journey through the field leading to a focus on the unresolved questions of the role of the SQ radicals and their possible part in proton pumping
Existence of Density Functionals for Excited States and Resonances
We show how every bound state of a finite system of identical fermions,
whether a ground state or an excited one, defines a density functional.
Degeneracies created by a symmetry group can be trivially lifted by a
pseudo-Zeeman effect. When complex scaling can be used to regularize a
resonance into a square integrable state, a DF also exists.Comment: 4 pages, no figure
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