Far infrared spectroscopy of FU Ori objects. ISO-LWS observations

We present the results of the first spectrophotometric observations of a sample of FU Ori objects obtained with the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). The [OI] (63 μm) and the [CII] (158 μm) lines are commonly observed in all spectra (both ON and OFF source). The observational novelty is the presence in most of the sources of the transition of ionised nitrogen [NII] (122 μm), which is not detected in other objects in a similar evolutionary phase. This line probes low ionisation and low density material not easily traced by other lines. Line intensities and intensity ratios are used along with model predictions to infer the prevailing mechanisms for line excitation. To reconcile our far-infrared spectroscopy with previous knowledge of these objects, the simultaneous presence of two components is required: well localised J-shocks, responsible for the [OI] emission, and an extended low density ionised medium produced by UV photons from the disc boundary layer, responsible for the [NII] and [CII] emission. A few molecular lines (CO, OH, H2O) associated with relatively cold and dense peaks are revealed and their intensities are in good agreement with the proposed scenario. Other ionic lines ([OIII] and [NIII]) are detected in two sources in the Cyg OB7 region and likely trace the presence of nearby HII regions

Silicon photonics in Pirelli

Silicon is the dominant material in the microelectronic industry and silicon photonics is rapidly gaining importance as a technological platform for a wide range of applications in telecom, and optical interconnect. It allows the implementation of many photonic functions through the use of wafer-scale technologies normally used for advanced CMOS-processing. In this paper some of the most important issues toward a practical implementation of Silicon photonics into an industrial device will be addressed: low loss waveguides, polarization handling, tunability, hitless switching. A tunable Add-Drop multiplexer has been chosen as a case Study of a fully integrated device

An infrared study of the L1551 star formation region

Spectroscopic observations using the Infrared Space Observatory are reported towards the two well known infrared sources and young stellar objects L1551 IRS 5 and L1551 NE, and at a number of locations in the molecular outflow. The ISO spectrum contains several weak gas-phase lines of O I, C II, [Fe II] and [Si II], along with solid state absorption lines of CO, CO2, H2O, CH4 and CH3OH. Hubble Space Telescope (HST) images with the NICMOS infrared camera reveal a diffuse conical shaped nebulosity, due to scattered light from the central object, with a jet emanating from L1551 IRS 5. The continuum spectral energy distribution has been modelled using a 2D radiative transfer model, and fitted for a central source luminosity of 45 L⊙, surrounding a dense torus extending to a distance of ~ 3x104 AU, which has a total mass of ~ 13 M⊙. The visual extinction along the outflow is estimated to be ≈ 10 and the mid-plane optical depth to L1551 IRS 5 to be ≈ 120. This model provides a good fit to the ISO spectral data, as well as to the spatial structures visible on archival HST/NICMOS data, mid-IR maps and sub-millimetre radio interferometry, and to ground-based photometry obtained with a range of different aperture sizes. On the basis of the above model, the extinction curve shows that emission at wavelengths shorter than ~ 2 μm is due to scattered light from close to L1551 IRS 5, while at wavelengths ≳ 4 μm, is seen through the full extinguishing column towards the central source. Several [Fe II] lines were detected in the SWS spectrum towards L1551 IRS 5. Although it would seem at first sight that shocks would be the most likely source of excitation for the [Fe II] in a known shocked region such as this, the line intensities do not fit the predictions of simple shock models. An alternative explanation has been examined where the [Fe II] gas is excited in hot ( ~ 4000 K) and dense (≳ 109 cm-3) material located close to the root of the outflow. The SWS observations did not detect any emission from rotationally excited H2. Observations with United Kingdom Infrared Telescope (UKIRT) of the vibrationally excited S- and Q-branch lines were however consistent with the gas having an excitation temperature of ~ 2500 K. There was no evidence of lower temperature ( ~ 500 K) H2 gas which might be visible in the rotational lines. Observations with UKIRT of the CO absorption bands close to 2.4 μm are best fit with gas temperatures ~ 2500 K, and a column density ~ 6x1020 cm-2. There is strong circumstantial evidence for the presence of dense (coronal and higher densities) and hot gas (at least 2500 K up to perhaps 5000 K) close to the protostar. However there is no obvious physical interpretation fitting all the data which can explain this

Use of efavirenz or atazanavir/ritonavir is associated with better clinical outcomes of HAART compared to other protease inhibitors: routine evidence from the Italian MASTER Cohort.

Randomized trials and observational cohorts reported higher rates of virological suppression after highly active antiretroviral therapy (HAART) including efavirenz (EFV), compared with boosted protease inhibitors (PIs). Correlations with immunological and clinical outcomes are unclear. Patients of the Italian MASTER cohort who started HAART from 2000 to 2010 were selected. Outstanding outcome (composite outcome for success (COS)) was introduced. We evaluated predictors of COS (no AIDS plus CD4+ count >500/ mm3 plus HIV-RNA <500 copies/mL) and of eight single outcomes either at month 6 or at year 3. Multivariable logistic regression was conducted. There were 6259 patients selected. Patients on EFV (43%) were younger, had greater CD4+ count, presented with AIDS less frequently, and more were Italians. At year 3, 90% of patients had HIV RNA <500 copies/mL, but only 41.4% were prescribed EFV, vs. 34.1% prescribed boosted PIs achieved COS (p <0.0001). At multivariable analysis, patients on lopinavir/ritonavir had an odds ratio of 0.70 for COS at year 3 (p <0.0001). Foreign origin and positive hepatitis C virus-Ab were independently associated with worse outcome (OR 0.54, p <0.0001 and OR 0.70, p 0.01, respectively). Patients on boosted PIs developed AIDS more frequently either at month 6 (13.8% vs. 7.6%, p <0.0001) or at year 3 (17.1% vs. 13.8%, p <0.0001). At year 3, deaths of patients starting EFV were 3%, vs. 5% on boosted PIs (p 0.008). In this study, naïve patients on EFV performed better than those on boosted PIs after adjustment for imbalances at baseline. Even when virological control is achieved, COS is relatively rare. Hepatitis C virus-positive patients and those of foreign origin are at risk of not obtaining COS. Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved

Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

Peer reviewe

Impiego in elezione della colostomia di protezione nella chirurgia resettiva del retto.

To clarify the indications and clinical value of "protective colostomy" in cases of low colorectal anastomoses, some recent series are analyzed and compared to the experience of the authors, which includes 65 low anterior resections of the rectum for cancer, with colorectal anastomosis at less than 10 cm from the anus. "Protective colostomy" seems not to prevent the onset of anastomotic fistulae, but appears effective in reducing its clinical effects. "Protective colostomy" seems convenient when there is an increased risk of fistulization, as indicated by a series of factors defined by the authors. In doubtful cases "protective colostomy" may be performed but not opened. So the patient will be given the maximum safety, and not submitted to the uneasiness of an open colostomy unless needed