Pensiero e immagini II Tradizione e innovazione nelle opere di Bruno e Campanella

Il volume contiene saggi su T. Campanella e su G. Bruno, risultati della Ricerca del Murst 1998-2000 (II vol.). In particolare: sugli "autori" letti ed emulati da Campanella, sulla "mens" nell'opera di Campanella, con considerazioni filosofiche e teologiche. I tre contributi su Bruno riguardano i "Sonetti" bruniani, l'immagine di Bruno, le "Apocalissi annunciate"

EXOMARS DRILL pre-EQM INTEGRATION AND PRELIMINARY QUALIFICATION CAMPAIGN

After completion of a breadboarding and test phase on the key components and assemblies of the ExoMars Drill, a new model, named Drill pre-EQM, more representative of the final flight design, has been integrated. Such model includes both parts that are already at qualification level (namely the structure and the mechanics) and parts at commercial level that later on will be upgraded to EQM level (e.g. the actuators). Meanwhile, an engineering model of the complete control electronics has also been integrated, and the first version of the control software (flight version) has been released. The pre-EQM interfaced with the EM control electronics is being subject to a thorough test campaign in these months. This campaign includes sample acquisition of Mars-analogue material in laboratory and in Mars-like conditions, with the double objective of getting confirmation of the key drilling parameters (such as needed resources in terms of power and thrust, advancing speed, amount of collected material, etc.) and of verifying the operability and timelines of the integrated Drill HW - Control Electronics - Flight Software. Tests will be conducted on the enlarged variety of soil materials already used to characterize the design in last phase. To support the environmental test campaign, a dedicated facility has been designed and built in order to reproduce Mars-Like conditions in terms of temperatures, atmospheric composition and pressure. Such unique facility has been realized in order to allow complete drill operations down to two meters depth

Sex-based differences in end-of-life decision making in Flanders, Belgium

Background: Sex-related differences in end-of-life decisions (EOLD) are underresearched and unexplored. Objectives: To investigate whether there are (1) differences in demographic and/or clinical characteristics between male and female decedents; (2) differences between men and women in the prevalence of EOLD with a possible or certain life-shortening effect; (3) differences in EOL decision making between men and women. Methods: In 2007, we performed a postmortem survey in Flanders, Belgium among physicians certifying a large representative sample (n = 6927) of death certificates. Response rate was 58.4%. Results: Of patients with nonsudden death, women more often die in a care home than men (31.4% vs. 18.2%) who more often die at home (24.1% vs. 17.9%). Men tend to die more often from cancer than women (45.4% vs. 32.1%). Decisions to withhold or withdraw potentially life-prolonging treatment are more often made in women (28.0% vs. 22.8%, P = 0.003); euthanasia and pain and symptoms treatment [alleviation of pain and symptoms (APS)] occur more often in men (3.6% vs. 2.1% euthanasia, P = 0.023; 41.8% vs. 36.9% APS, P = 0.012). These differences disappear after controlling for confounders. Bivariate associations were found between sex and EOL decision making. Some of them remained after controlling for confounders. Conclusions: It is not the patient's sex in itself that determines the likelihood of an EOLD, but the different clinical profiles of men and women at the end of life. Although sex is not a determining factor in the prevalence of EOLD, it influences the decision-making process, indicating that there may be a difference in the way that male and female patients participate in EOL decision making

Eleonora de Fonseca Pimentel tra mito e storia

Dagli interventi si ricostruisce la vicenda della rivoluzione partenopea del 1799 e in particolare della sua protagonista: prima fondatrice e direttrice di un giornale e interessante rappresentante della tradizione letteraria settecentesca: prima arcadica e poi rivoluzionaria

Comprehensive fitness landscape of SARS-CoV-2 Mpro reveals insights into viral resistance mechanisms.

With the continual evolution of new strains of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that are more virulent, transmissible, and able to evade current vaccines, there is an urgent need for effective anti-viral drugs. The SARS-CoV-2 main protease (Mpro) is a leading target for drug design due to its conserved and indispensable role in the viral life cycle. Drugs targeting Mpro appear promising but will elicit selection pressure for resistance. To understand resistance potential in Mpro, we performed a comprehensive mutational scan of the protease that analyzed the function of all possible single amino acid changes. We developed three separate high throughput assays of Mpro function in yeast, based on either the ability of Mpro variants to cleave at a defined cut-site or on the toxicity of their expression to yeast. We used deep sequencing to quantify the functional effects of each variant in each screen. The protein fitness landscapes from all three screens were strongly correlated, indicating that they captured the biophysical properties critical to Mpro function. The fitness landscapes revealed a non-active site location on the surface that is extremely sensitive to mutation, making it a favorable location to target with inhibitors. In addition, we found a network of critical amino acids that physically bridge the two active sites of the Mpro dimer. The clinical variants of Mpro were predominantly functional in our screens, indicating that Mpro is under strong selection pressure in the human population. Our results provide predictions of mutations that will be readily accessible to Mpro evolution and that are likely to contribute to drug resistance. This complete mutational guide of Mpro can be used in the design of inhibitors with reduced potential of evolving viral resistance

Molecular Determinants of Epistasis in HIV-1 Protease: Elucidating the Interdependence of L89V and L90M Mutations in Resistance

Protease inhibitors have the highest potency among antiviral therapies against HIV-1 infections, yet the virus can evolve resistance. Darunavir (DRV), currently the most potent Food and Drug Administration-approved protease inhibitor, retains potency against single-site mutations. However, complex combinations of mutations can confer resistance to DRV. While the interdependence between mutations within HIV-1 protease is key for inhibitor potency, the molecular mechanisms that underlie this control remain largely unknown. In this study, we investigated the interdependence between the L89V and L90M mutations and their effects on DRV binding. These two mutations have been reported to be positively correlated with one another in HIV-1 patient-derived protease isolates, with the presence of one mutation making the probability of the occurrence of the second mutation more likely. The focus of our investigation is a patient-derived isolate, with 24 mutations that we call KY ; this variant includes the L89V and L90M mutations. Three additional KY variants with back-mutations, KY(V89L), KY(M90L), and the KY(V89L/M90L) double mutation, were used to experimentally assess the individual and combined effects of these mutations on DRV inhibition and substrate processing. The enzymatic assays revealed that the KY(V89L) variant, with methionine at residue 90, is highly resistant, but its catalytic function is compromised. When a leucine to valine mutation at residue 89 is present simultaneously with the L90M mutation, a rescue of catalytic efficiency is observed. Molecular dynamics simulations of these DRV-bound protease variants reveal how the L90M mutation induces structural changes throughout the enzyme that undermine the binding interactions

Constrained mutational sampling of amino acids in HIV-1 protease evolution

The evolution of HIV-1 protein sequences should be governed by a combination of factors including nucleotide mutational probabilities, the genetic code, and fitness. The impact of these factors on protein sequence evolution are interdependent, making it challenging to infer the individual contribution of each factor from phylogenetic analyses alone. We investigated the protein sequence evolution of HIV-1 by determining an experimental fitness landscape of all individual amino acid changes in protease. We compared our experimental results to the frequency of protease variants in a publicly available dataset of 32,163 sequenced isolates from drug-naive individuals. The most common amino acids in sequenced isolates supported robust experimental fitness, indicating that the experimental fitness landscape captured key features of selection acting on protease during viral infections of hosts. Amino acid changes requiring multiple mutations from the likely ancestor were slightly less likely to support robust experimental fitness than single mutations, consistent with the genetic code favoring chemically conservative amino acid changes. Amino acids that were common in sequenced isolates were predominantly accessible by single mutations from the likely protease ancestor. Multiple mutations commonly observed in isolates were accessible by mutational walks with highly fit single mutation intermediates. Our results indicate that the prevalence of multiple base mutations in HIV-1 protease is strongly influenced by mutational sampling

Picomolar to Micromolar: Elucidating the Role of Distal Mutations in HIV-1 Protease in Conferring Drug Resistance

Drug resistance continues to be a growing global problem. The efficacy of small molecule inhibitors is threatened by pools of genetic diversity in all systems, including antibacterials, antifungals, cancer therapeutics, and antivirals. Resistant variants often include combinations of active site mutations and distal secondary mutations, which are thought to compensate for losses in enzymatic activity. HIV-1 protease is the ideal model system to investigate these combinations and underlying molecular mechanisms of resistance. Darunavir (DRV) binds wild-type (WT) HIV-1 protease with a potency ofpM, but we have identified a protease variant that loses potency to DRV 150000-fold, with 11 mutations in and outside the active site. To elucidate the roles of these mutations in DRV resistance, we used a multidisciplinary approach, combining enzymatic assays, crystallography, and molecular dynamics simulations. Analysis of protease variants with 1, 2, 4, 8, 9, 10, and 11 mutations showed that the primary active site mutations caused approximately 50-fold loss in potency (2 mutations), while distal mutations outside the active site further decreased DRV potency from 13 nM (8 mutations) to 0.76 muM (11 mutations). Crystal structures and simulations revealed that distal mutations induce subtle changes that are dynamically propagated through the protease. Our results reveal that changes remote from the active site directly and dramatically impact the potency of the inhibitor. Moreover, we find interdependent effects of mutations in conferring high levels of resistance. These mechanisms of resistance are likely applicable to many other quickly evolving drug targets, and the insights may have implications for the design of more robust inhibitors