We analyze the chemical abundances of planetary nebulae and HII regions in the M81 disk for insight on galactic evolution, and compare it with that of other galaxies, including the Milky Way. We ...acquired Hectospec/MMT spectra of 39 PNe and 20 HII regions, with 33 spectra viable for temperature and abundance analysis. Our PN observations represent the first PN spectra in M81 ever published, while several HII region spectra have been published before, although without a direct electron temperature determination. We determine elemental abundances of helium, nitrogen, oxygen, neon, sulfur, and argon in PNe and HII regions, and determine their averages and radial gradients. The average O/H ratio of PNe compared to that of the HII regions indicates a general oxygen enrichment in M81 in the last ~10 Gyr. The PN metallicity gradient in the disk of M81 is -0.055+-0.02 dex/kpc. Neon and sulfur in PNe have a radial distribution similar to that of oxygen, with similar gradient slopes. If we combine our HII sample with the one in the literature we find a possible mild evolution of the gradient slope, with results consistent with gradient steepening with time. Additional spectroscopy is needed to confirm this trend. There are no Type I PNe in our M81 sample, consistently with the observation of only the brightest bins of the PNLF, the galaxy metallicity, and the evolution of post-AGB shells. Both the young and the old populations of M81 disclose shallow but detectable negative radial metallicity gradient, which could be slightly steeper for the young population, thus not excluding a mild gradients steepening with the time since galaxy formation. During its evolution M81 has been producing oxygen; its total oxygen enrichment exceeds that of other nearby galaxies.
Nearby galaxies are ideal places to study in detail metallicity gradients and their time evolution. We consider chemical abundances of a new sample of \hii\ regions complemented with previous ...literature data-sets. We compare \hii\ region and PN abundances obtained with a common set of observations taken at MMT. With an updated theoretical model, we follow the time evolution of the baryonic components and chemical abundances in the disk of M33, assuming that the galaxy is accreting gas from an external reservoir. Supported by a uniform sample of nebular spectroscopic observations, we conclude that: {\em i}) the metallicity distribution in M33 is very complex, showing a central depression in metallicity probably due to observational bias; {\em ii}) the metallicity gradient in the disk of M33 has a slope of -0.037\(\pm\) 0.009 dex kpc\(^{-1}\) in the whole radial range up to \(\sim\)8 kpc, and -0.044\(\pm\) 0.009 dex kpc\(^{-1}\) excluding the central kpc; {\em iii}) there is a small evolution of the slope with time from the epoch of PN progenitor formation to the present-time.}
Valacyclovir (VCV) is the only treatment demonstrated to be effective for prevention of vertical transmission of Cytomegalovirus (CMV) within a clinical randomized, placebo controlled, trial and is ...reimbursed by the Italian National System since 2020.
We report the results of a real-life Italian multicenter observational study (MEGAL-ITALI) on CMV infection in pregnancy evaluating the impact of the introduction of VCV in the clinical practice for the prevention of vertical transmission of CMV.
The outcomes of women who received VCV treatment and their fetuses / newborns were compared with those of a retrospective cohort observed between 2010 and 2019 who did not receive the antiviral treatment. Inclusion criteria was diagnosis of CMV primary infection occurring in the periconceptional period or up to 24 weeks gestation. Primary outcome was the transmission by the time of amniocentesis. Secondary outcomes were termination of pregnancy, transmission at birth, symptomatic infection at birth, and a composite outcome (termination of pregnancy or transmission at birth).
447 pregnant women from 10 centers were enrolled, 205 treated with valacyclovir (called VCV group, including one twin pregnancy) and 242 untreated (including two twin pregnancies, called no-VCV group). VCV treatment was significantly associated with reduction of cCMV diagnosis by the time of amniocentesis (weighted odds ratio, OR, 0.39, 90% CI, 0.22-0.68; p = 0.005, relative reduction 61%), termination of pregnancy (weighted OR, 0.36, 90% CI, 0.17-0.75; p = 0.0021, relative reduction 64%), symptomatic cCMV infection at birth (weighted OR, 0.17, 90% CI, 0.06-0.49; p = 0.006, relative reduction 83%). The treatment had no significant effect on the rate of cCMV diagnosis at birth (weighted OR, 0.85, 90% CI, 0.57-1.26; p = 0.500), but the composite outcome (termination of pregnancy or diagnosis of cCMV at birth) occurred more frequently in the no VCV group (weighted OR, 0.62, 90% C, 0.44-0.88; p=0.024)
Of note, the three symptomatic newborns with cCMV in the VCV group were among those with positive amniocentesis. Nineteen women (9.3%) complained an adverse reaction to valacyclovir treatment classified as mild in 17 cases and moderate in 2 cases. Four women presented renal toxicity (1.9%) with a slight increase of creatinine, reversible after treatment suspension.
Our real-life data confirms that valacyclovir significantly reduces the cCMV rate at the time of amniocentesis with a good tolerability profile and shows that the treatment is associated with reduction of termination of pregnancy and symptomatic cCMV at birth.
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