Water-like Behavior of Formamide: Jump Reorientation Probed by Extended Depolarized Light Scattering.

Water is a strong self-associated liquid with peculiar properties that crucially depend on H-bonding. As regards its molecular dynamics, only recently has water reorientation been successfully described based on a jump mechanism, which is responsible for the overall H-bonding exchange. Here, using high-resolution broad-band depolarized light scattering, we have investigated the reorientational dynamics of formamide (FA) as a function of concentration from the neat liquid to diluted aqueous solutions. Our main findings indicate that in the diluted regime the water rearrangement can trigger the motion of FA solute molecules, which are forced to reorient at the same rate as water. This highlights an exceptional behavior of FA, which perfectly substitutes water within its network. Besides other fundamental implications connected with the relevance of FA, its water-like behavior provides rare experimental evidence of a solute whose dynamics is completely slaved to the solvent.

Painting biological low-frequency vibrational modes from small peptides to proteins.

Protein low-frequency vibrational modes are an important portion of a proteins' dynamical repertoire. Yet, it is notoriously difficult to isolate specific vibrational features in the spectra of proteins. Given an appropriately chosen model peptide, and using different experimental conditions, we can simplify the system and gain useful insights into the protein vibrational properties. Combining neutron scattering, depolarized light scattering, and molecular dynamics simulations, we analyse the low frequency vibrations of biological molecules, comparing the results from a small globular protein, lysozyme, and an amphiphilic peptide, NALMA, both in solution and in powder states. Lysozyme and NALMA present similar spectral features in the frequency range between 1 and 10 THz. With the aid of MD simulations, we assign the spectral features to methyl groups' librations (1-5 THz) and hindered torsions (5-10 THz) in NALMA. Our data also show that, while proteins display boson peak vibrations in both powder and solution forms, NALMA exhibits boson peak vibrations in powder form only. This provides insight into the nature of this feature, suggesting a connection of BP collective motions to a characteristic length scale of heterogeneities present in the system. These results provide context for the use of model peptide systems to study protein dynamics; demonstrating both their utility, and the great care that has to be used in extrapolating results observed in powder to solutions.

Hydration and aggregation in mono- and disaccharide aqueous solutions by gigahertz-to-terahertz light scattering and molecular dynamics simulations.

The relaxation properties of hydration water around fructose, glucose, sucrose, and trehalose molecules have been studied by means of extended frequency range depolarized light scattering and molecular dynamics simulations. Evidence is given of hydration dynamics retarded by a factor ξ = 5-6 for all the analyzed solutes. A dynamical hydration shell is defined based on the solute-induced slowing down of water mobility at picosecond time scales. The number of dynamically perturbed water molecules N(h) and its concentration dependence have been determined in glucose and trehalose aqueous solutions up to high solute weight fractions (ca. 45%). For highly dilute solutions, about 3.3 water molecules per sugar hydroxyl group are found to be part of the hydration shell of mono- and disaccharide. For increasing concentrations, a noticeable solute-dependent reduction of hydration number occurs, which has been attributed, in addition to simple statistical shells overlapping, to aggregation of solute molecules. A scaling law based on the number of hydroxyl groups collapses the N(h) concentration dependence of glucose and trehalose into a single master plot, suggesting hydration and aggregation properties independent of the size of the sugar. As a whole, the present results point to the concentration of hydroxyl groups as the parameter guiding both sugar-water and sugar-sugar interactions, without appreciable difference between mono- and disaccharides.

Rotational dynamics of trehalose in aqueous solutions studied by depolarized light scattering.

High resolution depolarized light scattering spectra, extended from 0.5 to 2x10(4) GHz by the combined used of a dispersive and an interferometric setup, give evidence of separated solute and solvent dynamics in diluted trehalose aqueous solutions. The slow relaxation process, located in the gigahertz frequency region, is analyzed as a function of temperature and concentration and assigned to the rotational diffusion of the sugar molecule. The results are discussed in comparison with the data obtained on glucose solutions and they are used to clarify the molecular origin of some among the several relaxation processes reported in literature for oligosaccharides solutions. The concentration dependence of relaxation time and of shear viscosity are also discussed, suggesting that the main effect of carbohydrate molecules on the structural relaxation of diluted aqueous solutions is the perturbation induced on the dynamics of the first hydration shell of each solute molecule.

[Working and health conditions and preventive measures in a random sample of 5000 workers in the Veneto Region examined by telephone interview]. / Condizioni di lavoro e di salute e attività di prevenzione in un campione di 5000 lavoratori del veneto esaminati con questionario mediante intervista telefonica.

BACKGROUND: A survey was carried out in 2000 by the European Foundation for the Improvement of Living and Working Conditions in a random sample of workers from 15 countries of the European Union in order to obtain information on occupational exposure, health problems and preventive measures taken at the workplaces. OBJECTIVES: To obtain similar information in workers in the Veneto Region and compare the results with those of the third European Survey on Working Conditions (ESWC). The results of the survey on Veneto Region workers were further analyzed, investigating the distribution by risk factors in each work sector, and the association between risk factors and reported health problems. METHODS: The ESWC questionnaire was adapted to the requirements of a telephone interview and a sample of 5000 workers (size based on the budget) between 15 and 64 years of age was randomly extracted from the regional list of telephone subscribers. The questionnaire was administered by trained interviewers. No statistical tests were used in the comparison between ESWC and Veneto Region results due to the lack of a priori hypotheses. Odds ratio (OR) was calculated in estimating the association between risk factors and symptoms; and p-value for OR trend across the increasing level of exposure was also obtained. RESULTS: Workers reported to be exposed for more than a quarter of their work time to: vibrations (20%), noise (19%), dusts, fumes vapours, chemicals (18%), repetitive hand/arm movements (50%), tiring/painful positions (46%); working at very high speed or tight deadlines (60%). 54.4% of the subjects reported working with computers. Taking as a reference the third ESWC in 2000, among Veneto Region workers in 2005 exposure was lower as regards physical, chemical and ergonomic risk factors, and similar as regards working at very high speed. The more frequently reported work-related health problems were: stress (26.9%), backache (17.8%), overall fatigue (11.9%), muscular pains in upper limbs (6.8%), headache (6.1%), sight problems (5.4%), anxiety (5.5%), muscular pain in lower limbs (4.3%), irritability (4.0%), hearing problems (2.3%). Except for stress, all symptoms/health problems were two-three times more frequently reported in the ESWC than in the Veneto Region survey where, conversely, the number of persons with at least one new sick- leave spell was higher. Lastly, there was no difference as regards preventive measures taken at the workplace: information on risks (78.2%), wearing personal protective equipment (28.7%), training paid by employer (28.7%). Among the Veneto Region workers, the most often reported risk factors were exposure to physical and chemical risk factors in industry/agriculture, and shift-work and working at very high speed in the services. The most commonly adopted preventive measures were information on risks and wearing of personal protective equipment in industry, and training in services. Moreover, among the Veneto Region workers, a significant exposure-dependent increase was reported for respiratory problems, allergies, dermatitis, hearing loss, accidents, back pain, pain in the upper and lower limbs, and headache. The risk of stress, anxiety, sleeping problems, stomach pain and headache increased when skills were not adequate to cope with job demand. In contrast, the perception of improved health conditions increased with increasing skill discretion, decision authority, social support (which are dimensions of control of job demand), but not with information on risk, training, or use of personal protective equipment. CONCLUSIONS: Data from the present survey provide useful insights on working and health conditions of workers in the Veneto Region, revealing problems that were subsequently investigated using other sources of information, as reported in the studies published elsewhere in this volume.

[Role of the ISPESL in quality of focal point of the European Agency for health and safety at work]. / Il ruolo dell'ISPESL in qualità di focal point dell'Agenzia Europea per la salute e sicurezza sul lavoro.

The building it re-enters more between the extended fields in Europe, with a advanced volume of transactions to 900 billions of euro to the year and beyond 12 million workers with reference to the single Union to 15. In the region, the implication of the medal is represented from record minimums of emergency and health on job (SSL), for one cost to cargo of the enterprises and the contributors that goes around every year around to 75 billions of euro, without to mention the uneasiness to the persons. Although important progresses caught up in the course of the time, faces to improve standard of SSL of the building industry, thanks to one more effective cooperation between employers, workers and others you leave interested, the job to make it is still very many. This year, European week for the emergency and the health on the job, dedicated to the field of the building, it is proposed to support every interested part of the field in the putting to fire of it upgrades them improvements in order to create job atmospheres surer, you heal and productive. The campaign, directed from the Agency for emergency and the health on the job, in its turn financed from the European Union, it will reunite a wide review of activity times make more aware on the main ones problems and the respective solutions. The present informative package has been created in order to supply information it generates them inherent to such problematic let alone the elements necessary in order to participate to the campaign.

[Genetic screenings: state of the art and perspectives for public health]. / Gli screening genetici: stato dell'arte e prospettive per la sanità pubblica.

Management of genetic data needs the fulfillment of technical requirements, involving ethics, law, and social issues. Introduction of genetic information in preventive medicine implies complex consequences and specialized expertise. Genetic screenings represent a promising tool, but further advances are needed to provide their effective and appropriate use in the respect of the privacy. Application areas, tests validation procedures and availability of effective laboratory and qualified service networks are considered. The Authors present main laws and bioethics guidelines in the field.