299 research outputs found
Liver function assessment in workers exposed to vinyl chloride
No full textObjective: To investigate liver function in vinyl chloride workers and assess its relation with current/past occupational exposure to vinyl chloride monomer (VCM). Methods: A medical examination including the execution of liver function tests (LFTs) and liver ultrasonography was executed in a group of 757 workers with a long-standing service in the production of VCM/ polyvinylchloride (PVC). Cumulative and maximum VCM exposures were calculated. History of viral hepatitis and alcohol intake were carefully investigated. Regression analysis explored the association between abnormal LFTs and a group of possible determinants (VCM cumulative and maximum exposure, BMI, age, history of viral hepatitis, alcohol and triglyceride levels). Also, synergistic effect between VCM and a history of hepatitis was analysed, as well as the possible association between VCM exposure and aspartate aminotransferase/alanine amino transferase (AST/ALT) ratio >1. Distribution of abnormal LFTs was also assessed in relation to the results provided by liver ultrasonography. Results: The most frequently abnormal serum parameters were, in decreasing order: total cholesterol (27.3%), triglycerides (12.2%), total bilirubin (9.1%), gamma glutamil transpeptidase (GGT; 9.0%) and ALT (8.2%). The AST/ALT ratio >1 was present in 28.1% of workers. Abnormal LFTs were not found to be associated with current or past VCM exposure. High ALT resulted positively associated with BMI, AST with alcohol intake, GGT with alcohol intake and triglycerides. No synergistic effect on LFTs of exposure to VCM and a history of hepatitis was observed. The AST/ALT ratio >1 was not found to be associated with VCM exposure. The prevalence of abnormal LFTs was higher in case of liver steatosis (ALT) or periportal fibrosis (GGT), but not in case of pure hepatomegaly, as documented by ultrasonography. Conclusions: Liver function assessment only including LFTs is not able to detect VCM-induced liver damage, but reveals alterations due to non-occupational factors, such as dietary and/or metabolic disfunctions. The LFTs are however of importance to detect conditions that could recommend avoidance of exposure to VCM and are useful for medical counselling and health promotion purposes
Structural and electronic properties of one dimensional inorganic and organic structures on surfaces
No full textWe investigate one-dimensional (1-D) nanostructures formed by deposition
of potassium on InAs(110) surface and of pentacene on the vicinal
Cu(119) surface. Scanning tunneling microscopy (STM) reveals the
morphology and the long-range ordering of the nanostructures.
Voltage-dependent STM images are used to investigate the electronic
structure in the real space. The potassium chains give rise to a
delocalized continuum of charge density, suggesting their 1-D electronic
nature. 1-D pentacene rows, growing beyond the completion of the first
layer, do not show a similar behavior. The formation of the 1-D
electronic structures is discussed in term of the substrate-adsorbate
interaction. (C) 2004 Elsevier B.V. All rights reserved
Renewable energy in Italy: incentives, bureaucratic obstacles and Nimby syndrome
No full textItaly is a country where the energy supply depends largely on imported raw materials (such as oil and natural gas). The favorable geographic location could encourage the development of renewable energy sources; nevertheless, the growth of alternative energy sources is slow. What are the reasons? This question will be dealt in this chapter, considering three different aspects of the issue: the economic incentives for renewable energies, the problematic process of authorization of the facilities and the local communities' opposition to new plants. Besides the analysis of these issues, the aim of this paper is to identify possible solutions, taking into account the relevant legislative and regulatory changes that, at national and Community level, have affected and are affecting the field of renewable energy
Megaturbidite deposits in the Holocene basin fill of Lake Como (Southern Alps, Italy)
No full textFor the first time, limnogeological investigations have been carried out in Lake Como, the deepest lake of the Alps, combining a bathymetric survey (multibeam Simrad 3000) with a high-resolution seismic reflection study (single-channel 3.5 kHz sub-bottom profiler) and a coring campaign (gravity corer). This data set enables detailed characterization of the sedimentary subsurface in the western branch of the lake, the Como branch, which has a typical fjord morphology. This paper focuses on the deepest part of the Como branch (Argegno basin), in which up to 3.5-m-thick turbidite deposits are identified. The basin fill of the Como branch is characterized by well-layered draping and onlapping pelagic sediments that are locally affected by creeping and that are intercalated with mass-wasting deposits, in particular with two large debris-flow deposits evolving into megaturbidites in the deepest part of the basin. The multibeam data together with the acoustic-facies distributions and the volumes of these two major sedimentary deposits MT1 ( 3 × 106 m3) and MT2 ( 10.5 × 106 m3) indicate that they resulted from large slides at the northern tip of the Como branch along the steep slopes of a sub-lacustrine plateau. The estimated ages of these events, around the mid-12th (MT1) and early 6th (MT2) centuries, are extrapolated from mean sedimentation rates based on radiocarbon (14C) and radionuclide (137Cs) analyses from short cores in the Argegno basin. Possible trigger mechanisms leading to these catastrophic events in the Como branch include a combination of steep-slope overloading, with significant lake-level fluctuations related to Holocene climate change and/or earthquake shaking. The tentative age assignment places the age of both major mass movements near two other events: MT1 near the occurrence of a major earthquake in the Po Plain in 1222 AD (Intensity IX MCS, macroseismically derived magnitude 6.2) and MT2 near a megaturbidite triggered in 700 AD in a proglacial lake in southeastern Switzerland [Blass, A., Anselmetti, F., Grosjean, M., Sturm, M., 2005. The last 1300 years of environmental history in the sediments of Lake Sils (Engadine, Switzerland). Eclogae Geologicae Helvetiae 98, 319–332]. Since dangerous, tsunami-like waves (seiches) can be generated by large sub-aqueous landslides leading to such megaturbidites in this fjord-like basin, future studies are required: 1) to constrain the age of these catastrophic events; 2) to document the stabilities of the steep slopes in the Como branch, 3) to assess the expected frequency of such catastrophic events and 4) to model the propagation of large waves in the Como branch and their potential damage along the highly populated lake shore
Morphology of pentacene films deposited on Cu(119) vicinal surface
No full textWe investigate the morphology of a pentacene (C22H14) film adsorbed on the Cu(119) vicinal surface by scanning tunnelling microscopy (STM). Thermal treatment of a thick film of molecules generates a long-range ordered structure. Series of molecular rows are alternated with areas where the molecules assume two equivalent orientations. STM data analysis suggests that the ordered structure can be described by a rippled morphology. The behaviour of the film at different annealing temperatures suggests a possible explanation of the film structure as due to an adsorbate-induced modification of the substrat
Risk assessment and management of occupational exposure to pesticides in agriculture
No full textNearly 50% of the world labour force is employed in agriculture. Over the last 50 years, agriculture has deeply
changed with a massive utilisation of pesticides and fertilisers to enhance crop protection and production, food quality
and food preservation. Pesticides are also increasingly employed for public health purposes and for domestic use.
Pesticide are unique chemicals as they are intrinsically toxic for several biological targets, are deliberately spread into
the environment, and their toxicity has a limited species selectivity. Pesticide toxicity depends on the compound
family and is generally greater for the older compounds; in humans, they are responsible for acute poisonings as well
as for long term health effects, including cancer and adverse effects on reproduction. Due to their intrinsic toxicity,
in most countries a specific and complex legislation prescribes a thorough risk assessment process for pesticides prior to
their entrance to the market (pre-marketing risk assessment). The post-marketing risk assessment takes place during
the use of pesticides and aims at assessing the risk for exposed operators. The results of the risk assessment are the base
for the health surveillance of exposed workers. Occupational exposure to pesticides in agriculture concerns product
distributors, mixers and loaders, applicators, bystanders, and rural workers re-entering the fields shortly after treatment.
Assessing and managing the occupational health risks posed by the use of pesticides in agriculture is a complex
but essential task for occupational health specialists and toxicologists. In spite of the economic and social importance
of agriculture, the health protection of agricultural workforce has been overlooked for too many years, causing an
heavy tribute paid in terms of avoidable diseases, human sufferance, and economic losses. Particularly in the developing
countries, where agricultural work is one of the predominant job, a sustainable model of development calls for
more attention to occupational risks in agriculture. The experience of many countries has shown that prevention of
health risk caused by pesticides is technically feasible and economically rewarding for the individuals and the whole
community. A proper risk assessment and management of pesticide use is an essential component of this preventative
strategy
Una terra che narra se stessa: la Bucovina e la 'letteratura etnografica
No full textThis paper aims to study a literary phenomenon that characterizes the multicultural society of Bukovina, a region of the former Austro-Hungarian empire, between 19th and the beginning of 20th century: the ethnographic literature. The object, which will be investigated through three case studies, provides evidence on the Hapsburg mythic narration of Bukovina exceptionalism – and of the empire exceptionalism, too
Molecular gap and energy level diagram for pentacene adsorbed on filled d-band metal surfaces
No full textThe authors present a combined photoemission and scanning-tunneling spectroscopy study of the filled electronic states, the molecular energy gap, and the energy level diagram of highly ordered arrays of pentacene deposited on the Cu(119) vicinal surface. The states localized at the interface are clearly singled out, comparing the results at different pentacene thicknesses and with gas-phase photoemission data. The molecular gap of 2.35 eV, the hole injection barrier of 1.05 eV, and the electron injection barrier of 1.30 eV determine the energy level diagram of the states localized at the pentacene molecules
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