2,162 research outputs found
Experimentally observed evolution between dynamic patterns and intrinsic localized modes in a driven nonlinear electrical cyclic lattice
Locked intrinsic localized modes (ILMs) and large amplitude lattice spatial
modes (LSMs) have been experimentally measured for a driven 1-D nonlinear
cyclic electric transmission line, where the nonlinear element is a saturable
capacitor. Depending on the number of cells and electrical lattice damping a
LSM of fixed shape can be tuned across the modal spectrum. Interestingly, by
tuning the driver frequency away from this spectrum an LSM can be continuously
converted into ILMs and visa versa. The differences in pattern formation
between simulations and experimental findings are due to a low concentration of
impurities. Through this novel nonlinear excitation and switching channel in
cyclic lattices either energy balanced or unbalanced LSMs and ILMs may occur.
Because of the general nature of these dynamical results for nonintegrable
lattices applications are to be expected. The ultimate stability of driven aero
machinery containing nonlinear periodic structures may be one example.Comment: 7 pages 7 figure
Guidelines for the proper use of etanercept in Japan
Application of biological agents targeting inflammatory cytokines such as tumor necrosis factor-α (TNF-α) dramatically caused a paradigm shift in the treatment of rheumatoid arthritis (RA). Infliximab, a chimeric anti-TNF-α monoclonal antibody, has initially been introduced to Japan in 2003 and shown to be dramatically effective in alleviating arthritis refractory to conventional treatment. However, serious adverse events such as bacterial pneumonia, tuberculosis, and Pneumocystis jiroveci pneumonia were reported to be in relatively high incidence; i.e., 2%, 0.3%, and 0.4%, respectively, in a strict postmarketing surveillance of an initial 4000 cases in Japan. Etancercept, a recombinant chimeric protein consisting of p75 TNF-α receptor and human IgG, was subsequently introduced to Japan in March of 2005. We therefore drew up treatment guidelines for the use of etanercept to avoid potential serous adverse events, since only approximately 150 cases have been included in the clinical study of etanercept in Japan. The guidelines were initially designed by the principal investigators (N.M, T.T., K.E.) of rheumatoid arthritis study groups of the Ministry of Health, Labor and Welfare (MHLW), Japan, and finally approved by the board of directors of the Japan College of Rheumatology. The MHLW assigned a duty to the pharmaceutical companies to perform a complete postmarketing surveillance of an initial 3000 cases to explore any adverse events, and this was performed according to the treatment guidelines shown in this article
Wave Chaos in Rotating Optical Cavities
It is shown that, even when the eigenmodes of an optical cavity are
wave-chaotic, the frequency splitting due to the rotation of the cavity occurs
and the frequency difference is proportional to the angular velocity although
the splitting eigenmodes are still wave-chaotic and do not correspond to any
unidirectionally-rotating waves.Comment: 4 pages, 6 figure
Rapid turnover of the recirculating lymphocyte pool in vivo
Lymphocytes are unique among blood cells in their capacity to continually recirculate between blood and the tissues via the lymph. Previous estimates of lymphocyte lifespan in vivo and the turnover of the recirculating lymphocyte pool have been deduced from indirect labeling techniques. Using the fluorescent dye PKH-26, individual labeled cells have been tracked in sheep for periods >2 months. By direct measurement their lifespan was calculated. This label was found to be stable in vivo, allowing long-term analysis of the characteristics of the recirculating lymphocyte pool. It Is possible to calculate the rate of turnover of cells of the recirculating pool based on the rate at which labeled cells disappear from the lymphatic circulation. The recirculating lymphocyte pool was found to repopulate itself every 16.5 ± 3.0 days. Using this label, it was estimated that recirculating lymphocytes divide on average once every 29.8 ± 6.8 days. Labeled erythrocytes were also examined and found to have an average lifespan of 153 days, demonstrating no dye loss over the 2 month period of observation. These data suggest that the recirculating lymphocyte pool is a highly dynamic compartment, with a high rate of turnover and peripheral cell division in vivo. This is the first report of the direct measurement of the in vivo turnover of recirculating lymphocyte pools, and this method may now be used to further analyze the lifespan of individual lymphocyte subsets and the in vivo lifespan of other cell types in viv
Glauber dynamics in a single-chain magnet: From theory to real systems
The Glauber dynamics is studied in a single-chain magnet. As predicted, a
single relaxation mode of the magnetization is found. Above 2.7 K, the
thermally activated relaxation time is mainly governed by the effect of
magnetic correlations and the energy barrier experienced by each magnetic unit.
This result is in perfect agreement with independent thermodynamical
measurements. Below 2.7 K, a crossover towards a relaxation regime is observed
that is interpreted as the manifestation of finite-size effects. The
temperature dependences of the relaxation time and of the magnetic
susceptibility reveal the importance of the boundary conditions.Comment: Submitted to PRL 10 May 2003. Submitted to PRB 12 December 2003;
published 15 April 200
Magnetic neutron scattering study of YVO3: Evidence for an orbital Peierls state
Neutron spectroscopy has revealed a highly unusual magnetic structure and
dynamics in YVO, an insulating pseudocubic perovskite that undergoes a
series of temperature induced phase transitions between states with different
spin and orbital ordering patterns. A good description of the neutron data is
obtained by a theoretical analysis of the spin and orbital correlations of a
realistic one-dimensional model. This leads to the tentative identification of
one of the phases of YVO with the ``orbital Peierls state'', a
theoretically proposed many-body state comprised of orbital singlet bonds.Comment: final version, to appear in PR
Comparative study of the effects of electron irradiation and natural disorder in single crystals of SrFe(AsP) (0.35) superconductor
London penetration depth, , was measured in single crystals of
SrFe(AsP) (0.35) iron - based superconductor. The
influence of disorder on the transition temperature, , and on
was investigated. The effects of scattering controlled by the annealing of
as-grown crystals was compared with the effects of artificial disorder
introduced by 2.5~MeV electron irradiation. The low temperature behavior of
can be described by a power-law function, , with the exponent close to one in pristine annealed samples, as
expected for superconducting gap with line nodes. Upon
\ecm irradiation, the exponent increases rapidly exceeding a dirty limit
value of 2 implying that the nodes in the superconducting gap are
accidental and can be lifted by the disorder. The variation of the exponent
with is much stronger in the irradiated crystals compared to the crystals
in which disorder was controlled by the annealing of the growth defects. We
discuss the results in terms of different influence of different types of
disorder on intra- and inter- band scattering
MuSR studies of RE(O,F)FeAs (RE = La, Nd, Ce) and LaOFeP systems: possible incommensurate/stripe magnetism and superfluid density
Muon spin relaxation (MuSR) measurements in iron oxy-pnictide systems have
revealed: (1) commensurate long-range order in undoped LaOFeAs; (2) Bessel
function line shape in La(O0.97F0.03)FeAs which indicates possible
incommensurate or stripe magnetism; (3) anomalous weak magnetism existing in
superconducting LaOFeP, Ce(O0.84F0.16)FeAs, and Nd(O0.88F0.12)FeAs but absent
in superconducting La(O0.92F0.08)FeAs; and (4) scaling of superfluid density
and Tc in the Ce, La, and Nd-FeAs superconductors following a nearly linear
relationship found in cuprates.Comment: 4 pages, 5 figures (color
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