Effects of nonlinear dispersion on squeezed states in two-photon devices

7 págs.; 4 figs.; 1 apémdiceThe deleterious effects of nonlinear dispersion on squeezed light in two-photon devices when absorption losses are included have been analyzed making use of the variables called two-mode quadrature-phase amplitudes. The uncertainties in the quadrature amplitudes have been computed from a generalized Fokker-Planck equation. The dependence of squeezing on the nonlinear coupling, the modulation (including the case of high modulations), the pumping phase (where nonlinear dispersion causes an intensity-dependent shift in the minimum squeezing), and the absorption losses have been studied. © 1989 The American Physical Society.Peer Reviewe

Low-noise properties of squeezed light in transmission chains formed from nonlinear alternating attenuators and amplifiers

4 págs.; 4 figs.An idealized model of an optical communication link in which identical sections of nonlinear attenuating fiber alternate with identical amplifiers is considered. Signal-to-noise ratios of chains of these elements for input squeezed and coherent light have been numerically evaluated. It is found that input squeezed light and nonlinear attenuators improve the signal-to-noise ratios with respect to coherent inputs and linear chains. In the case of three-photon attenuators, the noise and signal-to-noise ratio remain practically constant from certain elements of the chain. Moreover, the influence of the attenuation coefficient and the input mean photon number on the signal-to-noise ratios was considered, as well as chains with nonlinear amplifiers and chains in which the amplifier gain does not exactly compensate for the fiber attenuation. © 1988 The American Physical Society.Peer Reviewe

Transient behavior of a parametric amplifier with an added fourth-order interaction

8 págs.; 13 figs.; PACS number(s): 42.50.Dv, 42.65.Ky, 42.50.MdThe dynamical properties of an optical parametric amplifier with an added fourth-order (Kerr-effect term) nonlinearity are studied by means of a computer simulation of a semiclassical nonlinear Langevin formulation. The transient statistics above threshold are analyzed in detail, and the relevance of the present results for the production of squeezed light in traveling-wave devices is finally discussed. © 1992 The American Physical Society.Thiiss wwoork was supported in part by Grant No. TIC-90/80 (DGICYT, Spain).Peer Reviewe

Squeezing resulting from a fourth-order interaction in a degenerate parametric amplifier with absorption losses

7 págs.; 8 figs.The squeezing properties of a model of a degenerate parametric amplifier with absorption losses and an added fourth-order nonlinearity have been analyzed. The approach used consists of obtaining the Langevin equation for the optical field from the Heisenberg equation provided that a linearization procedure is valid. The steady states of the deterministic equations have been obtained and their local stability has been analyzed. The stationary covariance matrix has been calculated below and above threshold. Below threshold, a squeezed vacuum state is obtained and the nonlinear effects in the fluctuations have been taken into account by a Gaussian decoupling. In the case above threshold, a phase-squeezed coherent state is obtained and numerical simulations allowed to compute the time interval, depending on the loss parameter, on which the system jumps from one stable state to the other. Finally, the variances numerically determined have been compared with those obtained from the linearized theory and the limits of validity of the linear theory have been analyzed. It has become clear that the nonlinear contribution may perhaps be profitably used for the construction of above-threshold squeezing devices. © 1991 The American Physical Society.Peer Reviewe

Thermal study of a transport container

A thermal study of a container for international transport has been carried out in order to determine the temperature distributions. Several experimental conditions such as cooling modes, the onset of defrosting, the existence of cargo inside the container and two varying set points have been evaluated. It was observed that the difference between the temperature inside the container and the set point raised up to 30% of ambient temperature. Moreover, it was observed that the modulated cooling allowed to obtain a more homogeneous refrigeration. However, temperature differences up to 8 °C were observed under on–off control cooling

Optimization of RNA concentration for genome editing by CRISPR in rabbit zygotes

Site-specific genetic modification aiming to delete (knock-out) a gene provides an unequivocal answer to elucidate the function of such particular gene in the whole organism. Site-specific genetic modification has been achieved by homologous recombination, generally in embryonic stem cells, which has made the mouse the most widely used mammalian model

Tracking the effects of rigidity percolation down to the liquid state: relaxational dynamics of binary chalcogen melts

4 pags. ; 4 figs.The stochastic dynamics of binary liquids with formula AxB1-x, x=0–0.4 is investigated by neutron spin-echo spectroscopy. These compositions comprise samples of varying chemical connectivity, ranging from twofold-coordinated liquid Se to higher average coordinated As2S3. The parameters giving the temperature dependence of the relaxation patterns show a quasilinear dependence on the average coordination number. The results thus extend the validity of the rigidity concept into the normal liquid state and emphasize the role played by the fine details of atomic bonding on the dynamics at 10 ps–1 ns scales.Work supported in part by Grant No. MAT2007-65711-C-4-01, MEC, Spain.Peer reviewe

Acute kidney injury in patients treated with immune checkpoint inhibitors

Antígeno CTLA-4; InmunoterapiaAntigen CTLA-4; ImmunoteràpiaCTLA-4 antigen; ImmunotherapyBackground Immune checkpoint inhibitor-associated acute kidney injury (ICPi-AKI) has emerged as an important toxicity among patients with cancer. Methods We collected data on 429 patients with ICPi-AKI and 429 control patients who received ICPis contemporaneously but who did not develop ICPi-AKI from 30 sites in 10 countries. Multivariable logistic regression was used to identify predictors of ICPi-AKI and its recovery. A multivariable Cox model was used to estimate the effect of ICPi rechallenge versus no rechallenge on survival following ICPi-AKI. Results ICPi-AKI occurred at a median of 16 weeks (IQR 8–32) following ICPi initiation. Lower baseline estimated glomerular filtration rate, proton pump inhibitor (PPI) use, and extrarenal immune-related adverse events (irAEs) were each associated with a higher risk of ICPi-AKI. Acute tubulointerstitial nephritis was the most common lesion on kidney biopsy (125/151 biopsied patients [82.7%]). Renal recovery occurred in 276 patients (64.3%) at a median of 7 weeks (IQR 3–10) following ICPi-AKI. Treatment with corticosteroids within 14 days following ICPi-AKI diagnosis was associated with higher odds of renal recovery (adjusted OR 2.64; 95% CI 1.58 to 4.41). Among patients treated with corticosteroids, early initiation of corticosteroids (within 3 days of ICPi-AKI) was associated with a higher odds of renal recovery compared with later initiation (more than 3 days following ICPi-AKI) (adjusted OR 2.09; 95% CI 1.16 to 3.79). Of 121 patients rechallenged, 20 (16.5%) developed recurrent ICPi-AKI. There was no difference in survival among patients rechallenged versus those not rechallenged following ICPi-AKI. Conclusions Patients who developed ICPi-AKI were more likely to have impaired renal function at baseline, use a PPI, and have extrarenal irAEs. Two-thirds of patients had renal recovery following ICPi-AKI. Treatment with corticosteroids was associated with improved renal recovery.The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors

Influencia de los ligandos auxiliares en la reacción de activación de enlaces CH promovida por Pd

EL trabajo desarrollado se basa en determinar el papel de los ligandos auxiliares en los procesos de funcionalización C-H catalizados por paladio. La síntesis orgánica a través de procesos de funcionalización CH es una de las áreas que más expansión ha sufrido en la química los últimos 15 años. Esta metodología permite la formación de enlaces C-C, C-N, C-O y C-S (entre otros), y por tanto la creación de nuevos esqueletos orgánicos, mediante la modificación de enlaces C-H en precursores no modificados. En general, estos procesos están catalizados por metales de transición. Su ventaja fundamental es el ahorro de energía, etapas de reacción y tiempo, a la vez que se generan muchos menos residuos, y el control de la selectividad (quimio-, regio-, estéreo-). Por todo ello, es probablemente la metodología más empleada ahora en síntesis orgánica avanzada.El presente TFG se ha centrado en la química de paladio, como metal más representado en las funcionalizaciones CH, y en concreto en el papel de los ligandos auxiliares, verdaderos moduladores de la reactividad, en determinados tipos particulares de acoplamientos C-C. Este TFG abarca, , procesos de síntesis de orgánica de determinados compuestos, procesos de síntesis organometálica, y como se trasladan a reacciones catalíticas. Además se ha de hacer especial hincapié en la relación estructura- actividad (qué ligandos producen qué cambios). <br /

The activity of the Spanish Teratology Information Services (SITTE and SITE) during the year 2010

Otros Resultados: Actividad TraslacionalWe present a summary of the activity of the two Teratology Information Services: SITTE (for health professionals) and SITE (for the general population) during the year 2010. The total number of calls received in both services was 5,087 (814 received by SITTE and 4,273 by SITE). We present the distribution of calls along the years, as well as by the types of health professionals who performed the calls and the types of questions. Also, we show the distribution by different groups of exposures, including maternal diseases and their treatments, professional exposures, life styles, and others. Quantitatively, drug use has been the main reason for these queries. In addition, we have analyzed for the first time, the question regarding paternal diseases, treatments and professional exposures.N