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1.
Sci Total Environ ; 813: 152618, 2022 Mar 20.
Article in English | MEDLINE | ID: mdl-34968612

ABSTRACT

Marine litter is composed mainly of plastics and is recognized as a serious threat to marine ecosystems. Ecotoxicological approaches have started elucidating the potential severity of microplastics (MPs) in controlled laboratory studies with pristine materials but no information exists on marine environmental microlitter as a whole. Here, we characterized the litter in the coastal Northern Tyrrhenian sea and in the stomach of two fish species of socio-economic importance, and exposed primary cell cultures of mucosal and lymphoid organs to marine microlitter for evaluating possible cytotoxic effects. An average of 0.30 ± 0.02 microlitter items m-3 was found in water samples. µFT-IR analysis revealed that plastic particles, namely HDPE, polyamide and polypropylene were present in 100% and 83.3% of Merluccius merluccius and Mullus barbatus analyzed, which overall ingested 14.67 ± 4.10 and 5.50 ± 1.97 items/individual, respectively. Moreover, microlitter was confirmed as a vector of microorganisms. Lastly, the apical end-point of viability was found to be significantly reduced in splenic cells exposed in vitro to two microlitter conditions. Considering the role of the spleen in the mounting of adaptive immune responses, our results warrant more in-depth investigations for clarifying the actual susceptibility of these two species to anthropogenic microlitter.


Subject(s)
Plastics , Water Pollutants, Chemical , Animals , Ecosystem , Environmental Monitoring , Fishes , Mediterranean Sea , Water Pollutants, Chemical/analysis
2.
Sci Rep ; 9(1): 14672, 2019 Oct 11.
Article in English | MEDLINE | ID: mdl-31605020

ABSTRACT

Garnet is the archetypal cubic mineral, occurring in a wide variety of rock types in Earth's crust and upper mantle. Owing to its prevalence, durability and compositional diversity, garnet is used to investigate a broad range of geological processes. Although birefringence is a characteristic feature of rare Ca-Fe3+ garnet and Ca-rich hydrous garnet, the optical anisotropy that has occasionally been documented in common (that is, anhydrous Ca-Fe2+-Mg-Mn) garnet is generally attributed to internal strain of the cubic structure. Here we show that common garnet with a non-cubic (tetragonal) crystal structure is much more widespread than previously thought, occurring in low-temperature, high-pressure metamorphosed basalts (blueschists) from subduction zones and in low-grade metamorphosed mudstones (phyllites and schists) from orogenic belts. Indeed, a non-cubic symmetry appears to be typical of common garnet that forms at low temperatures (<450 °C), where it has a characteristic Fe-Ca-rich composition with very low Mg contents. We propose that, in most cases, garnet does not initially grow cubic. Our discovery indicates that the crystal chemistry and thermodynamic properties of garnet at low-temperature need to be re-assessed, with potential consequences for the application of garnet as an investigative tool in a broad range of geological environments.

3.
Phys Chem Chem Phys ; 20(33): 21764-21771, 2018 Aug 22.
Article in English | MEDLINE | ID: mdl-30106081

ABSTRACT

We investigated the oxidation behaviour of a synthetic potassic-ferro-richterite up to 750 °C by using simultaneous X-ray absorption spectroscopy and X-ray diffraction experiments with synchrotron radiation. From the X-ray diffraction results, we observed an abrupt decrease of cell dimensions at ∼335 °C accompanied by an anomalous increase in the monoclinic cell angle ß. From the analysis of the XANES spectra at the iron K-edge, we observed that the structural shrinkage is due to the iron oxidation process, coupled to hydrogen loss, occurring at ∼315 °C, slightly before the cell contraction. Combining these results with previous studies performed on similar samples by single-crystal structure refinement, Mössbauer, high temperature-Fourier transform IR and Raman spectroscopies, we show that the temperature evolution in Fe-amphiboles is a multi-step process. Following the iron oxidation driven by temperature, the structural dynamics in this double-chain silicate is ruled by local strains in the ribbon of iron-filled octahedra, mainly due to the contraction of the M(1) site.

4.
Anal Bioanal Chem ; 397(6): 2039-49, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20506014

ABSTRACT

In this paper we describe recent applications of micro-infrared imaging in the Earth sciences. We address, in particular, the use of Fourier-transform infrared (FTIR) spectroscopy in characterizing the zoning and speciation of H and C in a variety of geological materials, including microporous minerals, nominally anhydrous volcanic minerals (NAMs), and crystal inclusions. These investigations show that use of the modern techniques of FTIR imaging enables detection of the zoning of volatile species across the studied samples, and possible configuration changes of structurally-bound carbon molecular species (e.g., CO(2) vs CO(3)) during crystal growth. Such features, which are not accessible with other micro-analytical techniques, may provide information about the physicochemical properties which act as constraints in the genesis of the samples, and important information about the evolution of the geological system. Tests performed with focal-plane-array detectors (FPA) show that resolution close to the diffraction limit can be achieved if the amounts of the target molecules in the sample are substantially different. We also point out the possibility of using FTIR imaging for investigations under non-ambient conditions.

5.
Minerva Gastroenterol Dietol ; 41(2): 157-62, 1995 Jun.
Article in Italian | MEDLINE | ID: mdl-7647138

ABSTRACT

AIMS. 1) To evaluate the nutritional status of a group of alcohol abusers, relatively to their liver function and morphology, and 2) to compare these data with those of a previous study carried out by out team ten years ago. According to their body weight, 135 alcohol abusers were divided into three groups: normal-weight, over-weight and under-weight. The severity of their hepatopathy was defined as: 1. slight hepatopathy; 2. alcohol-induced hepatitis; 3. alcohol-induced hepatitis plus cirrhosis; 4 child A cirrhosis; 5. child B cirrhosis. RESULTS. 1. The overweight group was homogeneously distributed among the several degrees of compensated hepatopathy. 2. There was a marked reactivity to skin tests (Multitest) in patients with alcohol hepatitis without cirrhosis, independently of nutritional disorders. 3. Only decompensated cirrhosis may cause caloric-protein malnutrition; consequently, nutritional disorders due to alcohol abuse appear late and they are unlikely to play a leading role in the pathogenesis of liver disease due to alcohol abuse. Obesity, on the other hand, may facilitate the onset of liver steatosis.


Subject(s)
Liver Diseases, Alcoholic/complications , Nutrition Disorders/etiology , Adult , Body Weight , Fatty Liver, Alcoholic/complications , Fatty Liver, Alcoholic/diagnosis , Female , Hepatitis, Alcoholic/complications , Hepatitis, Alcoholic/diagnosis , Humans , Liver Cirrhosis, Alcoholic/complications , Liver Cirrhosis, Alcoholic/diagnosis , Liver Diseases, Alcoholic/diagnosis , Male , Middle Aged , Nutritional Status , Obesity/complications
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