Rigidity, Secondary Structure, and the Universality of the Boson Peak in Proteins

AbstractComplementary neutron- and light-scattering results on nine proteins and amino acids reveal the role of rigidity and secondary structure in determining the time- and lengthscales of low-frequency collective vibrational dynamics in proteins. These dynamics manifest in a spectral feature, known as the boson peak (BP), which is common to all disordered materials. We demonstrate that BP position scales systematically with structural motifs, reflecting local rigidity: disordered proteins appear softer than α-helical proteins; which are softer than β-sheet proteins. Our analysis also reveals a universal spectral shape of the BP in proteins and amino acid mixtures; superimposable on the shape observed in typical glasses. Uniformity in the underlying physical mechanism, independent of the specific chemical composition, connects the BP vibrations to nanometer-scale heterogeneities, providing an experimental benchmark for coarse-grained simulations, structure/rigidity relationships, and engineering of proteins for novel applications

An optimized, automatic TMS in operations in Roma Tiburtina and Monfalcone stations

Abstract A remarkable number of works on automatic train dispatching have recently appeared in the scientific literature, many of which also exploiting some exact or heuristic optimization. Despite of this blooming, very few automatic dispatching systems are actually in operations in main line or mass transit networks, mostly devoted to simple tasks in small lines. In this work we describe a recent implementation of a real time dispatching system monitoring and controlling trains in two large stations, namely Roma Tiburtina and Monfalcone. The system exploits optimization in order to take and implement crucial dispatching decisions. In particular, the algorithm finds suitable routes and schedules for the movements of trains in the station, so as to minimize costs and delays. The resulting trains movement is conflictfree, and respects safety and specific traffic rules. Also, it computes, exploits and provides accurate traffic forecast information based on the trains and railway real time status. A heuristic and an exact optimization algorithm, the latter based on Mixed Integer Linear Programming, are developed and run independently to introduce redundancy and increase safety. Computational experience on real-life instances shows that both methods are able to provide either good or optimal solutions in very short time (less than a second). A first release of the system is in operation since February 2014; the final release is scheduled to be operational by December 2014

Solvent contribution to the stability of a physical gel characterized by quasi-elastic neutron scattering

The dynamics of a physical gel, namely the Low Molecular Mass Organic Gelator {\textit Methyl-4,6-O-benzylidene-$\alpha$ -D-mannopyranoside ($\alpha$-manno)} in water and toluene are probed by neutron scattering. Using high gelator concentrations, we were able to determine, on a timescale from a few ps to 1 ns, the number of solvent molecules that are immobilised by the rigid network formed by the gelators. We found that only few toluene molecules per gelator participate to the network which is formed by hydrogen bonding between the gelators' sugar moieties. In water, however, the interactions leading to the gel formations are weaker, involving dipolar, hydrophobic or $\pi-\pi$ interactions and hydrogen bonds are formed between the gelators and the surrounding water. Therefore, around 10 to 14 water molecules per gelator are immobilised by the presence of the network. This study shows that neutron scattering can give valuable information about the behaviour of solvent confined in a molecular gel.Comment: Langmuir (2015

Impact on Prehospital Delay of a Stroke Preparedness Campaign: A SW-RCT (Stepped-Wedge Cluster Randomized Controlled Trial)

Background and Purpose—Public campaigns to increase stroke preparedness have been tested in different contexts, showing contradictory results. We evaluated the effectiveness of a stroke campaign, designed specifically for the Italian population in reducing prehospital delay. Methods—According to an SW-RCT (Stepped-Wedge Cluster Randomized Controlled Trial) design, the campaign was launched in 4 provinces in the northern part of the region Emilia Romagna at 3-month intervals in randomized sequence. The units of analysis were the patients admitted to hospital, with stroke and transient ischemic attack, over a time period of 15 months, beginning 3 months before the intervention was launched in the first province to allow for baseline data collection. The proportion of early arrivals (within 2 hours of symptom onset) was the primary outcome. Thrombolysis rate and some behavioral end points were the secondary outcomes. Data were analyzed using a fixed-effect model, adjusting for cluster and time trends. Results—We enrolled 1622 patients, 912 exposed and 710 nonexposed to the campaign. The proportion of early access was nonsignificantly lower in exposed patients (354 [38.8%] versus 315 [44.4%]; adjusted odds ratio, 0.81; 95% confidence interval, 0.60–1.08; P=0.15). As for secondary end points, an increase was found for stroke recognition, which approximated but did not reach statistical significance (P=0.07). Conclusions—Our campaign was not effective in reducing prehospital delay. Even if some limitations of the intervention, mainly in terms of duration, are taken into account, our study demonstrates that new communication strategies should be tested before large-scale implementation. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01881152

Water Dynamics at Protein Interfaces: Ultrafast Optical Kerr Effect Study

The behavior of water molecules surrounding a protein can have an important bearing on its structure and function. Consequently, a great deal of attention has been focused on changes in the relaxation dynamics of water when it is located at the protein surface. Here we use the ultrafast optical Kerr effect to study the H-bond structure and dynamics of aqueous solutions of proteins. Measurements are made for three proteins as a function of concentration. We find that the water dynamics in the first solvation layer of the proteins are slowed by up to a factor of 8 in comparison to those in bulk water. The most marked slowdown was observed for the most hydrophilic protein studied, bovine serum albumin, whereas the most hydrophobic protein, trypsin, had a slightly smaller effect. The terahertz Raman spectra of these protein solutions resemble those of pure water up to 5 wt % of protein, above which a new feature appears at 80 cm–1, which is assigned to a bending of the protein amide chain

Cumulative asbestos exposure and mortality from asbestos related diseases in a pooled analysis of 21 asbestos cement cohorts in Italy

Background: Despite the available information on cancer risk, asbestos is used in large areas in the world, mostly in the production of asbestos cement. Moreover, questions are raised regarding the shape of the dose response relation, the relation with time since exposure and the association with neoplasms in various organs. We conducted a study on the relationship between cumulative asbestos exposure and mortality from asbestos related diseases in a large Italian pool of 21 cohorts of asbestos-cement workers with protracted exposure to both chrysotile and amphibole asbestos. Methods: The cohort included 13,076 workers, 81.9% men and 18.1% women, working in 21 Italian asbestos-cement factories, with over 40 years of observation. Exposure was estimated by plant and period, and weighted for the type of asbestos used. Data were analysed with consideration of cause of death, cumulative exposure and time since first exposure (TSFE), and by gender. SMRs were computed using reference rates by region, gender and calendar time. Poisson regression models including cubic splines were used to analyse the effect of cumulative exposure to asbestos and TSFE on mortality for asbestos-related diseases. 95% Confidence Intervals (CI) were computed according to the Poisson distribution. Results: Mortality was significantly increased for ‘All Causes’ and ‘All Malignant Neoplasm (MN)’, in both genders. Considering asbestos related diseases (ARDs), statistically significant excesses were observed for MN of peritoneum (SMR: men 14.19; women 15.14), pleura (SMR: 22.35 and 48.10), lung (SMR: 1.67 and 1.67), ovary (in the highest exposure class SMR 2.45), and asbestosis (SMR: 507 and 1023). Mortality for ARDs, in particular pleural and peritoneal malignancies, lung cancer, ovarian cancer and asbestosis increased monotonically with cumulative exposure. Pleural MN mortality increased progressively in the first 40 years of TSFE, then reached a plateau, while peritoneal MN showed a continuous increase. The trend of lung cancer SMRs also showed a flattening after 40 years of TSFE. Attributable proportions for pleural, peritoneal, and lung MN were respectively 96, 93 and 40%. Conclusions: Mortality for ARDs was associated with cumulative exposure to asbestos. Risk of death from pleural MN did not increase indefinitely with TSFE but eventually reached a plateau, consistently with reports from other recent studie

Italian pool of asbestos workers cohorts: asbestos related mortality by industrial sector and cumulative exposure

Objective. Italy has been a large user of asbestos and asbestos containing materials until the 1992 ban. We present a pooled cohort study on long-term mortality in exposed workers. Methods. Pool of 43 Italian asbestos cohorts (asbestos cement, rolling stock, shipbuilding, glasswork, harbors, insulation and other industries). SMRs were computed by industrial sector for the 1970-2010 period, for the major causes, using reference rates by age, sex, region and calendar period. Results. The study included 51 801 subjects (5741 women): 55.9% alive, 42.6% died (cause known for 95%) and 1.5% lost to follow-up. Asbestos exposure was estimated at the plant and period levels. Asbestos related mortality was significantly increased. All industrial sectors showed increased mortality from pleural malignancies, and most als

The polymorphism L412F in TLR3 inhibits autophagy and is a marker of severe COVID-19 in males

The polymorphism L412F in TLR3 has been associated with several infectious diseases. However, the mechanism underlying this association is still unexplored. Here, we show that the L412F polymorphism in TLR3 is a marker of severity in COVID-19. This association increases in the sub-cohort of males. Impaired macroautophagy/autophagy and reduced TNF/TNFα production was demonstrated in HEK293 cells transfected with TLR3L412F-encoding plasmid and stimulated with specific agonist poly(I:C). A statistically significant reduced survival at 28 days was shown in L412F COVID-19 patients treated with the autophagy-inhibitor hydroxychloroquine (p = 0.038). An increased frequency of autoimmune disorders such as co-morbidity was found in L412F COVID-19 males with specific class II HLA haplotypes prone to autoantigen presentation. Our analyses indicate that L412F polymorphism makes males at risk of severe COVID-19 and provides a rationale for reinterpreting clinical trials considering autophagy pathways. Abbreviations: AP: autophagosome; AUC: area under the curve; BafA1: bafilomycin A1; COVID-19: coronavirus disease-2019; HCQ: hydroxychloroquine; RAP: rapamycin; ROC: receiver operating characteristic; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; TLR: toll like receptor; TNF/TNF-α: tumor necrosis factor

Valutazione della prevalenza del danno uditivo nell’esposizione, professionale a rumore, vibrazioni e sostanze ototossiche.

La Direttiva Europea 2003/10/CE obbliga il datore di lavoro a valutare l’esposizione al rumore dei propri dipendenti anche in rapporto alla presenza di fattori influenzanti il danno uditivo (vibrazioni, sostanze ototossiche, ecc.). Il presente lavoro analizza, in una popolazione di lavoratori del comparto metalmeccanico, la prevalenza del danno uditivo in caso di esposizione multifattoriale. A tale scopo, un campione rappresentativo della popolazione analizzata (348 lavoratori) è stato suddiviso in lavoratori esposti solo al rischio rumore (NEG) e lavoratori esposti ad almeno un altro fattore di rischio (MEG). Il campione è stato sottoposto a test audiometrico e anamnesi lavorativa al fine di determinare la prevalenza del danno uditivo. I dati mostrano una prevalenza del danno uditivo nella popolazione totale e nei due sottogruppi, in linea con il modello previsionale della norma internazionale (ISO 1999:1990). Si nota infine, una significativa prevalenza del danno uditivo, in accordo con la letteratura scientifica, per i lavoratori esposti al rumore ed a vibrazioni e/o sostanze ototossiche, che sono quindi maggiormente soggetti al rischio di ipoacusia professionale