RESUMO
Nonequilibrium transport properties are determined exactly for an adiabatically contacted single-channel quantum wire containing one impurity. Employing the Luttinger liquid model with interaction parameter g, for very strong interactions g less, similar0.2, and sufficiently low temperatures, we find an S-shaped current-voltage relation. The unstable branch with negative differential conductance gives rise to current oscillations and hysteretic effects. These nonperturbative and nonlinear features appear only out of equilibrium.
RESUMO
The authors evaluated the efficacy and safety of an OPAT program in a small group of patients affected by infective endocarditis. Three patients were considered eligible for the treatment; i.e. they had a stable hemodynamic balance and no embolic events. Streptococcus spp. grew in blood cultures of two patients, while blood cultures were negative in the third patient. Long-acting antibiotics were used and all patients recovered from the infection without adverse events. The treatment was efficacious and safe. This preliminary experience suggests that OPAT programs can be promoted in infective endocarditis with advantage. Strictness and caution are necessary in screening and monitoring patients.
Assuntos
Antibacterianos/administração & dosagem , Endocardite/tratamento farmacológico , Endocardite/microbiologia , Adulto , Assistência Ambulatorial , Feminino , Humanos , Infusões Parenterais , MasculinoRESUMO
The authors analysed retrospectively the clinical and laboratory features of patients hospitalised in a unit of infectious diseases in the period from 1996-99. In particular, the etiology, the antimicrobial susceptibility of responsible microorganisms, criteria utilized for diagnosis, antibiotic courses and outcomes were evaluated and discussed. Echocardiography is an essential tool in the diagnosis. Infective endocarditis remains a serious infection and is still associated with high morbidity and mortality rate, despite appropriate treatment. Seriously ill patients may require prompt surgery.
Assuntos
Endocardite/epidemiologia , Endocardite/microbiologia , Hospitalização , Adulto , Feminino , Humanos , Masculino , Estudos RetrospectivosAssuntos
Proteínas Adaptadoras de Transdução de Sinal/análise , Anticorpos/análise , Insuficiência Cardíaca/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Animais , Proteínas Reguladoras de Apoptose , Linhagem Celular , Doença Crônica , Feminino , Insuficiência Cardíaca/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Miócitos Cardíacos/metabolismo , Estrutura Terciária de Proteína , RatosRESUMO
A procedure for the extraction and determination of pulegone enanthiomers in mint essential oils and mint products (syrups, dried leaves, toothpaste, lozenges, candy and chewing-gum) was developed. The compounds were recovered from the food matrices by employing a simultaneous distillation-extraction (SDE) technique with a Likens-Nickerson apparatus using dichloromethane as an extraction solvent. The analyses were performed by capillary gas chromatography mass spectrometry (GC/MS). Experiments on food products spiked at different pulegone concentrations showed recoveries ranging from 95 to 106%. The detection limit was about 5?mg?l(-1) for both pulegone enanthiomers and good linearity was found in the concentration range 0.5-25?mg?l(-1). In a number of repeated analyses, the pulegone peak height repeatability (RSD) was 0.2%. The pulegone enanthiomers were separated and quantified by enanthioselective multidimensional gas chromatography. The results of analyses conducted on essential mint oils and mint-flavoured food products are reported.
Assuntos
Análise de Alimentos/métodos , Mentha/química , Monoterpenos/análise , Monoterpenos Cicloexânicos , Aromatizantes/química , Indústria Alimentícia/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Mentha piperita/química , Óleos Voláteis/química , Folhas de Planta/química , Óleos de Plantas/químicaRESUMO
We present theoretical results for the equilibrium Josephson current through an Anderson dot tuned into the magnetic regime, using Hirsch-Fye Monte Carlo simulations covering the complete crossover from Kondo-dominated physics to pi junction behavior in a numerically exact way. Within the "magnetic" regime, U/Gamma >> 1 and epsilon0/Gamma < or = 1, the Josephson current is found to depend only on Delta/TK, where Delta is the BCS gap and TK the Kondo temperature. The junction behavior can be classified into four different quantum phases. We describe these behaviors, specify the associated three transition points, and identify a local minimum in the critical current of the junction as a function of Delta/TK.
RESUMO
We study the Josephson current through a Luttinger liquid in contact with two superconductors. We show that it can be deduced from the Casimir energy in a two-boundary version of the sine-Gordon model. We develop a new thermodynamic Bethe ansatz, which, combined with a subtle analytic continuation procedure, allows us to calculate this energy in closed form, and obtain the complete current-crossover function from the case of complete normal to complete Andreev reflection.