Precise measurement of the thermal and stellar 54^{54}Fe(n,γn, \gamma)55^{55}Fe cross sections via AMS

The detection of long-lived radionuclides through ultra-sensitive single atom counting via accelerator mass spectrometry (AMS) offers opportunities for precise measurements of neutron capture cross sections, e.g. for nuclear astrophysics. The technique represents a truly complementary approach, completely independent of previous experimental methods. The potential of this technique is highlighted at the example of the $^{54}$Fe($n, \gamma$)$^{55}$Fe reaction. Following a series of irradiations with neutrons from cold and thermal to keV energies, the produced long-lived $^{55}$Fe nuclei ($t_{1/2}=2.744(9)$ yr) were analyzed at the Vienna Environmental Research Accelerator (VERA). A reproducibility of about 1% could be achieved for the detection of $^{55}$Fe, yielding cross section uncertainties of less than 3%. Thus, the new data can serve as anchor points to time-of-flight experiments. We report significantly improved neutron capture cross sections at thermal energy ($\sigma_{th}=2.30\pm0.07$ b) as well as for a quasi-Maxwellian spectrum of $kT=25$ keV ($\sigma=30.3\pm1.2$ mb) and for $E_n=481\pm53$ keV ($\sigma= 6.01\pm0.23$ mb). The new experimental cross sections have been used to deduce improved Maxwellian average cross sections in the temperature regime of the common $s$-process scenarios. The astrophysical impact is discussed using stellar models for low-mass AGB stars

Practical Recommendations for Optimal Thromboprophylaxis in Patients with COVID-19: A Consensus Statement Based on Available Clinical Trials.

Coronavirus disease 2019 (COVID-19) has been shown to be strongly associated with increased risk for venous thromboembolism events (VTE) mainly in the inpatient but also in the outpatient setting. Pharmacologic thromboprophylaxis has been shown to offer significant benefits in terms of reducing not only VTE events but also mortality, especially in acutely ill patients with COVID-19. Although the main source of evidence is derived from observational studies with several limitations, thromboprophylaxis is currently recommended for all hospitalized patients with acceptable bleeding risk by all national and international guidelines. Recently, high quality data from randomized controlled trials (RCTs) further support the role of thromboprophylaxis and provide insights into the optimal thromboprophylaxis strategy. The aim of this statement is to systematically review all the available evidence derived from RCTs regarding thromboprophylaxis strategies in patients with COVID-19 in different settings (either inpatient or outpatient) and provide evidence-based guidance to practical questions in everyday clinical practice. Clinical questions accompanied by practical recommendations are provided based on data derived from 20 RCTs that were identified and included in the present study. Overall, the main conclusions are: (i) thromboprophylaxis should be administered in all hospitalized patients with COVID-19, (ii) an optimal dose of inpatient thromboprophylaxis is dependent upon the severity of COVID-19, (iii) thromboprophylaxis should be administered on an individualized basis in post-discharge patients with COVID-19 with high thrombotic risk, and (iv) thromboprophylaxis should not be routinely administered in outpatients. Changes regarding the dominant SARS-CoV-2 variants, the wide immunization status (increasing rates of vaccination and reinfections), and the availability of antiviral therapies and monoclonal antibodies might affect the characteristics of patients with COVID-19; thus, future studies will inform us about the thrombotic risk and the optimal therapeutic strategies for these patients

Comparison of anticoagulation quality between acenocoumarol and warfarin in patients with mechanical prosthetic heart valves: Insights from the nationwide PLECTRUM study

Vitamin K antagonists are indicated for the thromboprophylaxis in patients with mechanical prosthetic heart valves (MPHV). However, it is unclear whether some differences between acenocoumarol and warfarin in terms of anticoagulation quality do exist. We included 2111 MPHV patients included in the nationwide PLECTRUM registry. We evaluated anticoagulation quality by the time in therapeutic range (TiTR). Factors associated with acenocoumarol use and with low TiTR were investigated by multivariable logistic regression analysis. Mean age was 56.8 ± 12.3 years; 44.6% of patients were women and 395 patients were on acenocoumarol. A multivariable logistic regression analysis showed that patients on acenocoumarol had more comorbidities (i.e., ≥3, odds ratio (OR) 1.443, 95% confidence interval (CI) 1.081-1.927, p = 0.013). The mean TiTR was lower in the acenocoumarol than in the warfarin group (56.1 ± 19.2% vs. 61.6 ± 19.4%, p < 0.001). A higher prevalence of TiTR (<60%, <65%, or <70%) was found in acenocoumarol users than in warfarin ones (p < 0.001 for all comparisons). Acenocoumarol use was associated with low TiTR regardless of the cutoff used at multivariable analysis. A lower TiTR on acenocoumarol was found in all subgroups of patients analyzed according to sex, hypertension, diabetes, age, valve site, atrial fibrillation, and INR range. In conclusion, anticoagulation quality was consistently lower in MPHV patients on acenocoumarol compared to those on warfarin

ccdc80-l1 Is Involved in Axon Pathfinding of Zebrafish Motoneurons

Axon pathfinding is a subfield of neural development by which neurons send out axons to reach the correct targets. In particular, motoneurons extend their axons toward skeletal muscles, leading to spontaneous motor activity. In this study, we identified the zebrafish Ccdc80 and Ccdc80-like1 (Ccdc80-l1) proteins in silico on the basis of their high aminoacidic sequence identity with the human CCDC80 (Coiled-Coil Domain Containing 80). We focused on ccdc80-l1 gene that is expressed in nervous and non-nervous tissues, in particular in territories correlated with axonal migration, such as adaxial cells and muscle pioneers. Loss of ccdc80-l1 in zebrafish embryos induced motility issues, although somitogenesis and myogenesis were not impaired. Our results strongly suggest that ccdc80-l1 is involved in axon guidance of primary and secondary motoneurons populations, but not in their proper formation. ccdc80-l1 has a differential role as regards the development of ventral and dorsal motoneurons, and this is consistent with the asymmetric distribution of the transcript. The axonal migration defects observed in ccdc80-l1 loss-of-function embryos are similar to the phenotype of several mutants with altered Hedgehog activity. Indeed, we reported that ccdc80-l1 expression is positively regulated by the Hedgehog pathway in adaxial cells and muscle pioneers. These findings strongly indicate ccdc80-l1 as a down-stream effector of the Hedgehog pathway

L'antichità nella cultura europea del Medioevo

Volume degli atti del convegno tenutosi a Padova dal 27.9.1997 al 1.10.199

Masca, maschera,masque, mask. Testi e iconografia nelle culture medievali

Il volume raccoglie saggi incentrati sulla maschera nel Medioev

Thin Liquid Sample Fabrication for Neutron Resonance Spectroscopy

In neutron resonance spectroscopy, preparation of thin cylindrical samples of large diameter containing 10_4210_5 atoms per barn of raw materials in powder form make pressing a uniform thickness sample difficult. The use of liquid samples is a suitable alternative to overcome the technical limits inherent to the fabrication of pressed solid samples by compaction methods. This paper presents the fabrication of a 2mm thick cylindrical sample, with a inner diameter of 65 mm, filled with an aqueous solution of lithium iodide. The sample was designed to measure the low neutron energy range of the 127I total cross-section by means of the neutron resonance transmission technique. The resonance shape analysis provided results consistent with those obtained by measuring a 17.5mm thick lead iodine sample under the same experimental conditions as for LiI sample. Such liquid sample could be used to repeat similar measurements on a large variety of stable isotopes and low radioactive materials.JRC.D.5-Neutron physic