Estimation of the Aerodynamic Force Induced by Vaneless Diffuser Rotating Stall in Centrifugal Compressor Stages

Abstract Rotating stall in centrifugal compressors not only adversely affects the performance before surge, but also can generate high subsynchronous vibrations, marking the minimum flow limit of a machine. Recent works presented an experimental approach to estimate the stall force induced by the unbalanced pressure field in a vaneless diffuser using dynamic pressure measurements. In this study, the results of a 3D-unsteady simulation of a radial stage model were used to estimate the stall force and to compare it with the approximation obtained with an "experimental-like" approach. Results showed that: a) the experimental approach, using an ensemble average approach for transposing data between time and space domains provides sufficiently accurate results; b) the momentum contribution, neglected in experiments, gives negligible contribution to the final intensity of the stall force

The role of immune suppression in COVID-19 hospitalization: clinical and epidemiological trends over three years of SARS-CoV-2 epidemic

Specific immune suppression types have been associated with a greater risk of severe COVID-19 disease and death. We analyzed data from patients >17 years that were hospitalized for COVID-19 at the “Fondazione IRCCS Ca′ Granda Ospedale Maggiore Policlinico” in Milan (Lombardy, Northern Italy). The study included 1727 SARS-CoV-2-positive patients (1,131 males, median age of 65 years) hospitalized between February 2020 and November 2022. Of these, 321 (18.6%, CI: 16.8–20.4%) had at least one condition defining immune suppression. Immune suppressed subjects were more likely to have other co-morbidities (80.4% vs. 69.8%, p < 0.001) and be vaccinated (37% vs. 12.7%, p < 0.001). We evaluated the contribution of immune suppression to hospitalization during the various stages of the epidemic and investigated whether immune suppression contributed to severe outcomes and death, also considering the vaccination status of the patients. The proportion of immune suppressed patients among all hospitalizations (initially stable at <20%) started to increase around December 2021, and remained high (30–50%). This change coincided with an increase in the proportions of older patients and patients with co-morbidities and with a decrease in the proportion of patients with severe outcomes. Vaccinated patients showed a lower proportion of severe outcomes; among non-vaccinated patients, severe outcomes were more common in immune suppressed individuals. Immune suppression was a significant predictor of severe outcomes, after adjusting for age, sex, co-morbidities, period of hospitalization, and vaccination status (OR: 1.64; 95% CI: 1.23–2.19), while vaccination was a protective factor (OR: 0.31; 95% IC: 0.20–0.47). However, after November 2021, differences in disease outcomes between vaccinated and non-vaccinated groups (for both immune suppressed and immune competent subjects) disappeared. Since December 2021, the spread of the less virulent Omicron variant and an overall higher level of induced and/or natural immunity likely contributed to the observed shift in hospitalized patient characteristics. Nonetheless, vaccination against SARS-CoV-2, likely in combination with naturally acquired immunity, effectively reduced severe outcomes in both immune competent (73.9% vs. 48.2%, p < 0.001) and immune suppressed (66.4% vs. 35.2%, p < 0.001) patients, confirming previous observations about the value of the vaccine in preventing serious disease

Survival and recruitment in the population ecology of the endangered Bombina pachypus (Amphibia: Anura): Supplementary Material

<p>Global amphibian decline is a subject of great conservation concern, yet often basic demographic information is absent, which prevents the understanding of population trends and the planning of effective conservation management. We analysed capture-mark-recapture data from six populations of the endangered<i> Bombina pachypus</i> in order to understand the relative contribution of survival and recruitment to population growth, and to assess if any differences exist among populations in terms of their population dynamics. We found that survival was rather high and generally constant among sites, and recruitment was low, with the exception of two single years at one site. Population growth depended on survival on all sites, except the years following high recruitment at one site. Annual population size was generally lower than 30 individuals, but in one site it was estimated to be larger than 50. Our findings suggest that juvenile survival is more important for population dynamics than recruitment from the larval to the juvenile stage. We also suggest that the low recruitment rates we recorded was a result of juvenile dispersal, and that when populations exhibited high recruitment it was due to occasional successful migration or local recruitment. This pattern could represent a way to counterbalance the risk of inbreeding in populations composed of few individuals, a common characteristic of populations of <i>B. pachypus</i>. Finally, we suggest that conservation measures for <i>B. pachypus</i> should be planned at the landscape scale, and should not be limited solely to the breeding site and its close surroundings.</p

Updates on Novel Non-Replacement Drugs for Hemophilia

Over the last decade, the world of hemophilia has experienced an unprecedented therapeutic advance, thanks to the progress in bioengineering technologies, leading to the introduction of drugs with novel mechanisms of action based on restoring thrombin generation or coagulation factor VIII mimicking. Apart from the bispecific monoclonal antibody emicizumab, already approved for patients with severe hemophilia A with and without inhibitors, novel non-replacement drugs designed to reduce the treatment burden of patients with hemophilia A or B with or without inhibitors are undergoing evaluation in clinical trials. Thanks to their innovative mechanism of action and subcutaneous administration, these drugs promise to provide effective bleeding protection together with improved adherence and improve health-related quality of life for patients with hemophilia. On the other hand, rare thromboembolic events have been reported with some of these drugs and warrant continuous post-marketing surveillance and investigation of predisposing factors, although the overall safety profile of most of these drugs is good. Finally, new challenges need to be faced in the clinical and laboratory monitoring of the hemostatic status in patients treated with these innovative therapies. In this review, we provide an update on the available data on novel non-replacement drugs currently undergoing evaluation in clinical trials for patients with hemophilia

Rapporto finale del gruppo di lavoro "Benessere Organizzativo nel CNR"

Technical repor

Archaeobotany in Italian ancient Roman harbours

International audienceThe present study is a review of the archaeobotanical analyses carried out in the last decade at the three ancient Roman port/dock system sites of Pisae, Portus, and Neapolis. Pollen, plant macrofossils (leaf, wood, seed/fruit macroremains) and wood constituting the shipwrecks were considered, and the results, partly unpublished, integrated and interpreted. Waterlogged sediments from these port areas turned out to be particularly suited for archaeobotanical analysis and opened new perspectives in ancient harbour studies. This is the first time that a synthesis of archaeobotanical data from Italian archaeological sites of the same typology is attempted for the Roman period. The disparate sampling strategies and available materials for macrofossil analysis in the various sites – cores in Portus, short sediment sequences in Pisae, and single visible hand-collected macroremains in Neapolis – conditioned the results obtained for these remains, making the comparison among sites a particularly difficult task. The urgency of establishing a common protocol between archaeologists and archaeobotanists is thus emphasized. The plant micro-and macrofossils highlight that in Roman times the landscape of the Italian coasts between Pisa and Naples was formed by deciduous oak plain forests (whose relicts are preserved in some protected areas, like in Parco Nazionale del Circeo, south of Rome and along the coast of the Pisan plain, in the Migliarino San Rossore Regional Park) with prevalence of mesophilous elements. The Mediterranean vegetation was not widespread as expected and maquis was limited to small areas by the coast. Surprisingly, mountain elements such as beech and silver fir were not so rare in pre-Roman times, suggesting that these trees could have occupied wider areas than at present. Besides food plant remains typical of the Roman age, the port sediments also preserved seeds, fruits and leaves of the wild vegetation. Comparing the results obtained by palynology with the shipwreck wood study showed that the boats were prevailingly built with local timber, often with conifers. The use of silver fir, though never very frequent, still confirms the preference of shipbuilders for this timber, which was not always available in the close surroundings of the three sites

Estimation of the Aerodynamic Force Induced by Vaneless Diffuser Rotating Stall in Centrifugal Compressor Stages

Rotating stall in centrifugal compressors not only adversely affects the performance before surge, but also can generate high subsynchronous vibrations, marking the minimum flow limit of a machine. Recent works presented an experimental approach to estimate the stall force induced by the unbalanced pressure field in a vaneless diffuser using dynamic pressure measurements. In this study, the results of a 3D-unsteady simulation of a radial stage model were used to estimate the stall force and to compare it with the approximation obtained with an "experimental-like" approach. Results showed that: A) the experimental approach, using an ensemble average approach for transposing data between time and space domains provides sufficiently accurate results; b) the momentum contribution, neglected in experiments, gives negligible contribution to the final intensity of the stall force

Archaeobotany in Italian ancient Roman harbours

Sintesi di dati palinologici e paleobotanici su tre porti Romani in Itali

Archaeobotany in Italian ancient Roman harbours

The present study is a review of the archaeobotanical analyses carried out in the last decade at the three ancient Roman port/dock system sites of Pisae, Portus, and Neapolis. Pollen, plant macrofossils (leaf, wood, seed/fruit macroremains) and wood constituting the shipwrecks were considered, and the results, partly unpublished, integrated and interpreted. Waterlogged sediments from these port areas turned out to be particularly suited for archaeobotanical analysis and opened new perspectives in ancient harbour studies. This is the first time that a synthesis of archaeobotanical data from Italian archaeological sites of the same typology is attempted for the Roman period. The disparate sampling strategies and available materials for macrofossil analysis in the various sites – cores in Portus, short sediment sequences in Pisae, and single visible hand-collectedmacroremains in Neapolis – conditioned the results obtained for these remains, making the comparison among sites a particularly difficult task. The urgency of establishing a common protocol between archaeologists and archaeobotanists is thus emphasized. The plant micro- andmacrofossils highlight that in Roman times the landscape of the Italian coasts between Pisa and Naples was formed by deciduous oak plain forests (whose relicts are preserved in some protected areas, like in Parco Nazionale del Circeo, south of Rome and along the coast of the Pisan plain, in the Migliarino San Rossore Regional Park) with prevalence of mesophilous elements. The Mediterranean vegetation was not widespread as expected andmaquiswas limited to small areas by the coast. Surprisingly,mountain elements such as beech and silver fir were not so rare in pre-Roman times, suggesting that these trees could have occupied wider areas than at present. Besides food plant remains typical of the Roman age, the port sediments also preserved seeds, fruits and leaves of the wild vegetation. Comparing the results obtained by palynology with the shipwreck wood study showed that the boats were prevailingly built with local timber, often with conifers. The use of silver fir, though never very frequent, still confirms the preference of shipbuilders for this timber, which was not always available in the close surroundings of the three sites