GeV Gamma-Ray Attenuation and the High-Redshift UV Background

We present new calculations of the evolving UV background out to the epoch of cosmological reionization and make predictions for the amount of GeV gamma-ray attenuation by electron-positron pair production. Our results are based on recent semi-analytic models of galaxy formation, which provide predictions of the dust-extinguished UV radiation field due to starlight, and empirical estimates of the contribution due to quasars. We account for the reprocessing of ionizing photons by the intergalactic medium. We test whether our models can reproduce estimates of the ionizing background at high redshift from flux decrement analysis and proximity effect measurements from quasar spectra, and identify a range of models that can satisfy these constraints. Pair-production against soft diffuse photons leads to a spectral cutoff feature for gamma rays observed between 10 and 100 GeV. This cutoff varies with redshift and the assumed star formation and quasar evolution models. We find only negligible amounts of absorption for gamma rays observed below 10 GeV for any emission redshift. With observations of high-redshift sources in sufficient numbers by the Fermi Gamma-ray Space Telescope and new ground-based instruments it should be possible to constrain the extragalactic background light in the UV and optical portion of the spectrum.Comment: 19 pages, 12 figures, Accepted for publication in MNRAS, this version includes minor correction

Beta-Blocker Use in Older Hospitalized Patients Affected by Heart Failure and Chronic Obstructive Pulmonary Disease: An Italian Survey From the REPOSI Register

Beta (β)-blockers (BB) are useful in reducing morbidity and mortality in patients with heart failure (HF) and concomitant chronic obstructive pulmonary disease (COPD). Nevertheless, the use of BBs could induce bronchoconstriction due to β2-blockade. For this reason, both the ESC and GOLD guidelines strongly suggest the use of selective β1-BB in patients with HF and COPD. However, low adherence to guidelines was observed in multiple clinical settings. The aim of the study was to investigate the BBs use in older patients affected by HF and COPD, recorded in the REPOSI register. Of 942 patients affected by HF, 47.1% were treated with BBs. The use of BBs was significantly lower in patients with HF and COPD than in patients affected by HF alone, both at admission and at discharge (admission, 36.9% vs. 51.3%; discharge, 38.0% vs. 51.7%). In addition, no further BB users were found at discharge. The probability to being treated with a BB was significantly lower in patients with HF also affected by COPD (adj. OR, 95% CI: 0.50, 0.37-0.67), while the diagnosis of COPD was not associated with the choice of selective β1-BB (adj. OR, 95% CI: 1.33, 0.76-2.34). Despite clear recommendations by clinical guidelines, a significant underuse of BBs was also observed after hospital discharge. In COPD affected patients, physicians unreasonably reject BBs use, rather than choosing a β1-BB. The expected improvement of the BB prescriptions after hospitalization was not observed. A multidisciplinary approach among hospital physicians, general practitioners, and pharmacologists should be carried out for better drug management and adherence to guideline recommendations

Multimorbidity and polypharmacy in the elderly: lessons from REPOSI

The dramatic demographic changes that are occurring in the third millennium are modifying the mission of generalist professionals such as primary care physicians and internists. Multiple chronic diseases and the related prescription of multiple medications are becoming typical problems and present many challenges. Unfortunately, the available evidence regarding the efficacy of medications has been generated by clinical trials involving patients completely different from those currently admitted to internal medicine: much younger, affected by a single disease and managed in a highly controlled research environment. Because only registries can provide information on drug effectiveness in real-life conditions, REPOSI started in 2008 with the goal of acquiring data on elderly people acutely admitted to medical or geriatric hospital wards in Italy. The main goals of the registry were to evaluate drug prescription appropriateness, the relationship between multimorbidity/polypharmacy and such cogent outcomes as hospital mortality and re-hospitalization, and the identification of disease clusters that most often concomitantly occur in the elderly. The findings of 3-yearly REPOSI runs (2008, 2010, 2012) suggest the following pertinent tasks for the internist in order to optimally handle their elderly patients: the management of multiple medications, the need to become acquainted with geriatric multidimensional tools, the promotion and implementation of a multidisciplinary team approach to patient health and care and the corresponding involvement of patients and their relatives and caregivers. There is also a need for more research, tailored to the peculiar features of the multimorbid elderly patient

Assignment of absolute configuration of chiral carboxylic acids via exciton-coupled CD treatment: 4-phenylthioproline as a case study

The 4-hydroxybenzoate chromophore was used as an exciton reporter group for the assignment of the absolute configuration of a chiral carboxylic acid of pharmaceutical interest, (-)-(2S,4S)-4-phenylthioproline, precursor of the ACE-inhibitor zofenopril. The nondegenerate coupling with the preexisting phenylthio chromophore was observed. A detailed conformational analysis, accomplished by means of H-1-NMR NOESY and semiempirical PM3 computational methods, and quantitative CD calculations were necessary to substantiate the assignment based on a weak experimental couplet

The health and economic burden of air pollution

The economic burden of air pollution goes beyond the costs generated by the effects on health, owing to multifaceted consequences for human welfare that encompass the ecosystem, agriculture and buildings. There is robust epidemiological evidence of the impact on health of air pollution. This is in contrast with the paucity of data on the economic impact, particularly for non-health related ones