349 research outputs found
Low-frequency modes in the Raman spectrum of sp-sp2 nanostructured carbon
A novel form of amorphous carbon with sp-sp2 hybridization has been recently
produced by supersonic cluster beam deposition showing the presence in the film
of both polyynic and cumulenic species [L. Ravagnan et al. Phys. Rev. Lett. 98,
216103 (2007)]. Here we present a in situ Raman characterization of the low
frequency vibrational region (400-800 cm-1) of sp-sp2 films at different
temperatures. We report the presence of two peaks at 450 cm-1 and 720 cm-1. The
lower frequency peak shows an evolution with the variation of the sp content
and it can be attributed, with the support of density functional theory (DFT)
simulations, to bending modes of sp linear structures. The peak at 720 cm-1
does not vary with the sp content and it can be attributed to a feature in the
vibrational density of states activated by the disorder of the sp2 phase.Comment: 15 pages, 5 figures, 1 tabl
In Situ Treatment of Contaminated Water Environments: The Experiment of the Arsenale Vecchio, Venice Lagoon, Italy
We report on the results of an experiment of in situ bioremediation by forced aeration, carried out in the Arsenale Vecchio shipyard dock basin of the Venice Lagoon, Italy. The experimental area is characterized by its limited size and reduced boat traffic. The forced aeration technique chosen for the oxygenation of the highly polluted bottom sediments and of the water column above does not obstruct harbor activities and is unique due to its innovative use of a system of porous pipes laid on the bottom sediments. The general recovery of the polluted shipyard dock basin resulted in the documented return of small fish to the area as an indication of a less polluted environment. Most important the bioremediation of the water body above the
bottom sediment favours, with time, the formation of a clean natural sediment capping over the bottom contaminated sediments. Post-experiment control after fifteen months of aeration with no extra oxygen added, shows the presence of clean light grey sediments with no foul septic smell, deposited over the polluted
bottom sediments. The experiment has indicated that oxygenation by porous pipe forced aeration could represent a cost effective and environmentally feasible way for the recovery of shallow marine and fresh water systems, in situations where other techniques may not be economically and/or environmentally feasible
Ticks infesting humans in Italy and associated pathogens
Background: Ticks may transmit a large variety of pathogens, which cause illnesses in animals and humans, commonly referred to as to tick-borne diseases (TBDs). The incidence of human TBDs in Italy is underestimated because of poor surveillance and the scant amount of studies available. Methods. Samples (n = 561) were collected from humans in four main geographical areas of Italy (i.e., northwestern, northeastern, southern Italy, and Sicily), which represent a variety of environments. After being morphologically identified, ticks were molecularly tested with selected protocols for the presence of pathogens of the genera Rickettsia, Babesia, Theileria, Candidatus Neoehrlichia mikurensis, Borrelia and Anaplasma. Results: Ticks belonged to 16 species of the genera Argas, Dermacentor, Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus, with Ixodes ricinus (59.5%) being the species most frequently retrieved, followed by Rhipicephalus sanguineus sensu lato (21.4%). Nymphs were the life stage most frequently retrieved (41%), followed by adult females (34.6%). The overall positivity to any pathogen detected was 18%. Detected microorganisms were Rickettsia spp. (17.0%), Anaplasma phagocytophilum (0.8%), Borrelia afzelii (0.5%), Borrelia valaisiana (0.3%), C. N. mikurensis (0.5%) and Babesia venatorum (0.6%). Conclusions: Results indicate that people living in the Italian peninsula are at risk of being bitten by different tick species, which may transmit a plethora of TBD causing pathogens and that co-infections may also occur. © 2014 Otranto et al.; licensee BioMed Central Ltd
Improvement on frozen mitochondria bioassay: a methodological remark.
The protocol for the bioassay with the mitochondria of beef heart frozen at -22 °C, (developed by Iero, Manente, Bragadin and Perin, in Chemosphere, 52, 2003) requires that the reaction cell is thermostatically controlled at 25 °C. This value was chosen because it is used as a reference for the state environmental standard (Standard Ambient Temperature and Pressure, SATP).
The choice is not, therefore, been supported by assessments on the effectiveness of the test at this temperature, but was dictated by the practice of reporting results to a standard temperature value.
Finally, it was decided to make a comparison between the working temperature of 25 °C and the 37 °C one, chosen as close to cattle body temperature (estimated to be 38.6 °C), then "normal" working temperature for mitochondria extracted from heart
The central role of Italy in the spatial spread of USUTU virus in Europe
USUTU virus (USUV) is an arbovirus maintained in the environment through a bird-mosquito enzootic cycle. Previous surveillance plans highlighted the endemicity of USUV in North-eastern Italy. In this work, we sequenced 138 new USUV full genomes from mosquito pools (Culex pipiens) and wild birds collected in North-eastern Italy and we investigated the evolutionary processes (phylogenetic analysis, selection pressure and evolutionary time-scale analysis) and spatial spread of USUV strains circulating in the European context and in Italy, with a particular focus on North-eastern Italy. Our results confirmed the circulation of viruses belonging to four different lineages in Italy (EU1, EU2, EU3 and EU4), with the newly sequenced viruses from the North-eastern regions, Veneto and Friuli Venezia Giulia, belonging to the EU2 lineage and clustering into two different sub-lineages, EU2-A and EU2-B. Specific mutations characterize each European lineage and geographic location seem to have shaped their phylogenetic structure. By investigating the spatial spread in Europe, we were able to show that Italy acted mainly as donor of USUV to neighbouring countries. At a national level, we identified two geographical clusters mainly circulating in Northern and North-western Italy, spreading both northward and southward. Our analyses provide important information on the spatial and evolutionary dynamics of USUTU virus that can help to improve surveillance plans and control strategies for this virus of increasing concern for human health
An alternative to Neutral Red as a dye for environmental contaminant biomonitoring.
Many methods have been proposed for evaluating of toxic compound presence in water and then to assess the risks to both humans and animals. A common standards procedure for the measuring of contaminant toxicity strength in sea water organisms utilizes the response of a dye (Neutral Red), which accumulates in the acidic vescicles of biological sensors (i.e. Mollusc). When marine Mollusc such as mussels are exposed to pollutants, one of the characteristic pathological alterations is a decreased integrity in the lysosomal membrane. In this work we propose a comparison with the responses obtained with another dye, Acridine Orange.
The results show that the response of Acridine Orange is linear in the whole operative pH range (i.e., between pH 4 and 7,4), while Neutral Red is insensitive between pH 6 and 7,4.
In addition, Neutral Red shows a protonophore behaviour. We propose therefore that the use of Acridine Orange is preferred to that of Neutral Red, as well that Acridine Orange should be alternative to Neutral Red for the monitoring of stressing environment contaminants by means of biological sensors
Anti-inflammatory Effect of Resveratrol and Polydatinby In Vitro IL-17 Modulation.
Interleukin-17 (IL-17) is a proinflammatory cytokine produced, although not exclusively, by T helper 17 recently identified as a distinct T helper lineage mediating tissue inflammation. IL-17 is known to be involved in a number of chronic disorders although the mechanisms regulating its production in inflammatory disease are still unclear. The beneficial properties of the polyphenolic compound resveratrol including its nti-inflammatory, antioxidant, and antitumor effects, its role in the aging process and in the prevention of heart and neurodegenerative diseases are well-known. In addition, derivatives of resveratrol, including glucosylated molecules as polydatin have been linked to similar beneficial effects. We have investigated the effects of resveratrol and polydatin on the in vitro production of IL-17 in a model of inflammation in vitro. The results obtained by activated human peripheral blood mononuclear cells, stimulated with anti-CD3/anti-CD28 monoclonal antibodies and treated with these polyphenolic compounds at different concentrations show that both decrease IL-17 production in a concentration-dependent manner. This study confirms the anti-inflammatory
activity of resveratrol and its derivatives and suggests a potential clinical relevance in the therapy of inflammatory diseases
FM22 (Frozen Mitochondria bioassay): an animal alternative bioassay for toxicity measures for water soluble samples.
Several methods have been proposed, using responses of whole organisms. The problem, however, is not only strictly scientific, but also involves cost, resources and time. For example, assay with organisms require expensive testing facilities and long operational times are necessary for toxicity measurements. In order to evaluate potential compound toxicity (acute and sub-chronic), we standardized a bioassay using mitochondria of beef hearth, and their applicability and sensitivity was verified.
In respect to other based on mitochondria tests, this bioassay (called FM22) showed unquestionable advantages: i) to freeze mitochondria at -22 °C instead of the classical -80 °C, ii) to perform a very big quantity of biological test using always the same mitochondria pool (avoiding differences from age, sex, or health status depending on different organisms); iii) to identify quickly a tested compounds IC50, easily comparable. FM22 end point is the inhibition of mitochondrial respiratory chain and this event is quantified by oxygen monitoring. The oxygen consumption was measured by a Clark electrode that was interfaced to a PC to collect test analysis data (1200 in 20 Macro, identifiedmin run). A piecewise regression, through an Excel the break point in the oxygen consumption and calculated the toxicity. Blank tests were carried out to verify the oxygen consumption linear fitting. Toxicity tests were performed using pure/mix organic and inorganic compounds, elutriates from sea- and fresh-water sediment, sewage, dissolved burned compound sub-products. The FM22 test was a good predictor of toxicity for water and soluble samples; the bioassay is easy, low cost and rapid, then usable for routine tests or like a part of a battery of ecotoxicological tests
- …