24,009 research outputs found
Kounis Syndrome Associated With Selective Anaphylaxis to Cefazolin.
info:eu-repo/semantics/publishedVersio
High magnetic field induced charge density wave states in a quasi-one dimensional organic conductor
We have measured the high field magnetoresistence and magnetization of
quasi-one- dimensional (Q1D) organic conductor (Per)2Pt(mnt)2 (where Per =
perylene and mnt = maleonitriledithiolate), which has a charge density wave
(CDW) ground state at zero magnetic field below 8 K. We find that the CDW
ground state is suppressed with moderate magnetic fields of order 20 T, as
expected from a mean field theory treatment of Pauli effects[W. Dieterich and
P. Fulde, Z. Physik 265, 239 - 243 (1973)]. At higher magnetic fields, a new,
density wave state with sub-phases is observed in the range 20 to 50 T, which
is reminiscent of the cascade of field induced, quantized, spin density wave
phases (FISDW) observed in the Bechgaard salts. The new density wave state,
which we tenatively identify as a field induced charge density wave state
(FICDW), is re-entrant to a low resistance state at even higher fields, of
order 50 T and above. Unlike the FISDW ground state, the FICDW state is only
weakly orbital, and appears for all directions of magnetic field. Our findings
are substantiated by electrical resistivity, magnetization, thermoelectric, and
Hall measurements. We discuss our results in light of theoretical work
involving magnetic field dependent Q1D CDW ground states in high magnetic
fields [D. Zanchi, A. Bjelis, and G. Montambaux, Phys. Rev. B 53, (1996)1240;
A. Lebed, JETP Lett. 78,138(2003)].Comment: 16 pages, 5 figure
Neutral heavy lepton production at next high energy linear colliders
The discovery potential for detecting new heavy Majorana and Dirac neutrinos
at some recently proposed high energy colliders is discussed. These
new particles are suggested by grand unified theories and superstring-inspired
models. For these models the production of a single heavy neutrino is shown to
be more relevant than pair production when comparing cross sections and
neutrino mass ranges.
The process is calculated
including on-shell and off-shell heavy neutrino effects.
We present a detailed study of cross sections and distributions that shows a
clear separation between the signal and standard model contributions, even
after including hadronization effects.Comment: 4 pages including 15 figures, 1 table. RevTex. Accepted in Physical
Review
Decoherence of Semiclassical Wigner Functions
The Lindblad equation governs general markovian evolution of the density
operator in an open quantum system. An expression for the rate of change of the
Wigner function as a sum of integrals is one of the forms of the Weyl
representation for this equation. The semiclassical description of the Wigner
function in terms of chords, each with its classically defined amplitude and
phase, is thus inserted in the integrals, which leads to an explicit
differential equation for the Wigner function. All the Lindblad operators are
assumed to be represented by smooth phase space functions corresponding to
classical variables. In the case that these are real, representing hermitian
operators, the semiclassical Lindblad equation can be integrated. There results
a simple extension of the unitary evolution of the semiclassical Wigner
function, which does not affect the phase of each chord contribution, while
dampening its amplitude. This decreases exponentially, as governed by the time
integral of the square difference of the Lindblad functions along the classical
trajectories of both tips of each chord. The decay of the amplitudes is shown
to imply diffusion in energy for initial states that are nearly pure.
Projecting the Wigner function onto an orthogonal position or momentum basis,
the dampening of long chords emerges as the exponential decay of off-diagonal
elements of the density matrix.Comment: 23 pg, 2 fi
Potato production impacts of the association trichodorids and TRV in naturally infected fields
An investigation was conducted to determine the effect of soil-born Tobacco rattle virus (TRV) isolates on yield and some quality attributes of 8 potato cultivars (Agata, Amorosa, Almera, Cunéria, Kondor, Picasso, Raja and Stemster) in Portuguese growing areas. Preliminary results revealed that some attributes (canopy growth, total yield, tuber numbers and yield within size grades, tuber spraing symptoms and secondary growths) are severely affected in the sites with viruliferous trichodorids transmitting TRV. It was shown that TRV has real conditions for survival and cause economic impact in potato crop in these regions. These results have potential interest to all potato growing countries.Centro de Biologia Molecular e Ambiental (CBMA), UMCentre of Natural Resources, Environment and Society Studies (CERNAS), College of Agriculture of Coimbra (ESAC)Eurobatata, Comércio de Produtos Alimentares, Lda, PORTUGA
Cutaneous manifestations of antiphospholipid syndrome: a review of the clinical features, diagnosis and management
Antiphospholipid syndrome is a relatively recent systemic autoimmune disorder defined by thrombotic events and/or obstetric complications in the presence of persistent elevated antiphospholipid antibodies. It is characterized by a wide spectrum of clinical presentations
and virtually any organ system or tissue may be affected by the consequences of vascular occlusion.
Diagnosis is sometimes difficult and although classification criteria have been published and revised there remain ongoing issues regarding nomenclature, expanding clinical features, laboratory tests and management and much still has to be done. Cutaneous manifestations are common and frequently the first sign of the disease. Although extremely diverse it’s important to know which dermatological findings should prompt consideration of antiphospholipid syndrome and the appropriate management for those patients. Much has
been debated about when to consider antiphospholipid syndrome and consensus still does not exist, however in spite of being a diagnostic challenge clinicians should know when to look for antiphospholipid antibodies since an early diagnosis is important to prevent further
and serious complications. In this article we focus on the cutaneous features that should raise suspicion on the presence of antiphospholipid syndrome and on the complex management of such patients. Many other dermatological signs related to this syndrome have been described in the literature but only occasionally and without consistency or statistic impact and therefore will not be considered hereO sÃndrome antifosfolipidico é uma patologia auto-imune relativamente recente definida por eventos trombóticos e/ou complicações obstétricas na presença de anticorpos antifosfolÃpido elevados persistentes. Caracteriza-se por um vasto leque de apresentações clÃnicas e virtualmente qualquer sistema orgânico ou tecido pode ser afectado por oclusão vascular. O diagnóstico é por vezes difÃcil e, apesar de critérios de classificação terem sido publicados e revistos, muitas dúvidas persistem relativamente à nomenclatura, caracterÃsticas clÃnicas, testes laboratoriais e abordagem destes doentes. As manifestações cutâneas são comuns e, frequentemente, o primeiro sinal da doença. Apesar da grande variabilidade, é importante reconhecer os achados dermatológicos que
devem levantar a suspeita de um sÃndrome antifosfolipidico, assim como a abordagem adequada destes doentes. Muito tem sido debatido sobre quando considerar o diagnóstico desta entidade, não havendo ainda consenso neste assunto; no entanto, apesar de ser um desafio diagnóstico, é importante saber quando investigar a presença de anticorpos antifosfolÃpidos, uma vez que um diagnóstico precoce é crucial para prevenir complicações
futuras graves. No presente artigo os autores descrevem as manifestações dermatológicas que devem fazer considerar o diagnóstico com enfoque na abordagem complexa destes doentes. Têm sido descritas na literatura muitas outras alterações cutâneas relacionadas
com esta entidade, no entanto, apenas de forma ocasional e sem consistência ou impacto estatÃstico, pelo que não serão consideradas
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