Search results for "chimica"
showing 10 items of 4450 documents
Newly discovered orichalcum ingots from Mediterranean sea: Further investigation
2021
Abstract In February 2016, 47 ingots were found in the seabed of Contrada Bulala (Gela, CL, Italy) near the site where 40 ingots had previously been recovered. The ingots composition was determined to be a Cu - Zn alloy, dated by the archaeologist to the VI century B.C. This specific alloy was then known as Orichalcum. From an archaeological point of view, the first question raised about the new discovery was whether the ingots of the first and the second excavations belonged to the same shipwreck. Following the previous study, an elemental analysis was performed on the ingots from the second finding by using ICP-OS and ICP-MS techniques. The chemometric treatment of the analytical results …
Life after death: a physicochemical study of materials used by the ancient Maya in human bone ointments
2021
Ancient Maya believed in life after death. They used to prepare dead bodies during burial ceremonies whose purpose was to celebrate the dead and to help them passing through the way from earthly life to the beyond one. Bodies preparation included coloured scented body ointment application, with a deep symbolic connotation and probably also a conservative purpose. The aim of this research was to characterize pigments and binders used by ancient Maya in the preparation of body oint ments used to paint human bones. Emblematic painted bone samples from Xcambó (Maya archaeological site located in the municipality of Dzemul, in the Mexican state of Yucatán) were investigated through a non-destruc…
Investigation on four centuripe vases (late 3rd-2nd cent. B.C.) by portable X-ray fluorescence and total reflectance-FTIR
2021
Abstract Four Centuripe vases dated back to the late 3rd-2nd centuries B.C. were analysed using imaging under visible and ultra-violet illumination as well as complementary non-invasive and non-destructive portable X-Ray Fluorescence (XRF) and Total Reflectance – Fourier Transform InfraRed (TR-FTIR) spectroscopies. The vases are of great importance since they represent a rare expression of the Hellenistic vase painting. Four specimens, a “pyxis”, a “lebes gamikos” and two “lekanides” decorated with figures of different type, are exhibited in the Antonino Salinas Archaeological Museum in Palermo-Italy. The investigation was aimed to identify the used pigments and the painting technique, to r…
Non-Invasive Investigation of Pigments of Wall Painting in S. Maria Delle Palate di Tusa (Messina, Italy)
2019
The characterization of materials used in the archaeological field needs an experimental approach in order to avoid the destruction or perturbation of artworks. In order to afford this purpose, a multi-analytical spectroscopic approach is regularly used. We combined non-invasive analysis by using handheld spectroscopic instrumentations (mainly XRF and Raman spectrometers) in order to characterize the wall painting preserved in the church of S. Maria delle Palate at Halaesa Arconidea archeological site (Tusa, Messina, Italy). The aim of the work is the characterization of the nature of pigments used for the realization of the wall painting. The wall painting, probably representing St. Franci…
New organotin(IV) complexes with L-Arginine,Nα-t-Boc-L-Arginine and L-Alanyl-L-Arginine.Synthesis, structural investigations and cytotoxic activity
2010
Abstract Novel diorganotin(IV) derivatives of l -Arginine (HArg), N α -( tert -Butoxycarbonyl)- l -Arginine (Boc–Arg–OH) and l -Ala- l -Arg (H 2 Ala–Arg), H 2 NC( NH)NH(CH 2 ) 3 CH(NHR′)CO 2 H, where R′ = H in HArg, R′ = C(O)OC(CH 3 ) 3 in Boc–Arg–OH, R′ = H 2 NCH(CH 3 )CO in H 2 Ala–Arg and triorganotin(IV) derivatives of Boc–Arg–OH have been synthesized and structurally characterized. The complexes were investigated by FT-IR and 119 Sn Mossbauer in the solid state and by 1 H, 13 C, 119 Sn and 1 H– 1 H COSY NMR spectroscopy, in solution. The spectroscopic characterization leading to the proposed molecular structures was accomplished on the basis of these experiments. l -Arginine appears to…
Biological effects of inorganic arsenic on primary cultures of rat astrocytes
2010
It is well established that inorganic arsenic induces neurotoxic effects and neurological defects in humans and laboratory animals. The cellular and molecular mechanisms of its actions, however, remain elusive. Herein we report the effects of arsenite (NaAsO2) on primary cultures of rat astrocytes. Cells underwent induction of heat shock protein 70 only at the highest doses of inorganic arsenic (30 and 60 microM), suggesting a high threshold to respond to stress. We also investigated arsenic genotoxicity with the comet assay. Interestingly, although cells treated with 10 microM arsenite for 24 h maintained >70% viability, with respect to untreated cells, high DNA damage was already observed…
Antibacterial and antifungal activities of Otanthus maritimus (L.) Hoffmanns.Link essential oil from Sicily.
2013
The chemical composition of the essential oil obtained from the flowers of Otanthus maritimus L., a perennial plant growing wild in maritime sands in the Mediterranean region, was investigated by GC and GC-MS analyses. Totally 66 were identified. The oil was dominated by the high content of monoterpene compounds, especially oxygenated monoterpenes which accounted for 73.1%. The most abundant components were yomogi alcohol (20.8%), camphor (15.8%), artemisyl acetate (15.3%) and artemisia alcohol (13.7%). The oil was tested against two Gram (+) and six Gram (-) bacterial strains, both American Type Culture Collection standard strains and clinically isolated (CI), one potentially pathogenic ye…
An active form of sphingosine kinase-1 is released in the extracellular medium as component of membrane vesicles shed by two human tumor cell line.
2010
Expression of sphingosine kinase-1 (SphK-1) correlates with a poor survival rate of tumor patients. This effect is probably due to the ability of SphK-1 to be released into the extracellular medium where it catalyzes the biosynthesis of sphingosine-1-phosphate (S1P), a signaling molecule endowed with profound proangiogenic effects. SphK-1 is a leaderless protein which is secreted by an unconventional mechanism. In this paper, we will show that in human hepatocarcinoma Sk-Hep1 cells, extracellular signaling is followed by targeting the enzyme to the cell surface and parallels targeting of FGF-2 to the budding vesicles. We will also show that SphK-1 is present in a catalitycally active form i…
Chemical and Microbiological Characterization for PDO Labelling of Typical East Piedmont (Italy) Salami
2015
This study is focused on the characterisation of typical salami produced in Alessandria province (North West of Italy). Seventeen small or medium salami producers from this area were involved in the study and provided the samples investigated. The aim is double and consists in obtaining a screening of the characteristics of different products and following their evolution along ripening. The study involved five types of typical salami that were characterised for aroma components and nutritional features. This approach could provide a basis for a possible PDO or PGI label request. Principal Component Analysis and cluster analysis were used as multivariate statistical tools for data treatment…
Midinfrared FT-IR as a Tool for Monitoring Herbaceous Biomass Composition and Its Conversion to Furfural
2015
A semiquantitative analysis by means of midinfrared FT-IR spectroscopy was tuned for the simultaneous determination of cellulose, hemicellulose, and lignin in industrial crops such as giant reed (Arundo donaxL.) and switchgrass (Panicum virgatumL.). Ternary mixtures of pure cellulose, hemicellulose, and lignin were prepared and a direct correlation area/concentration was achieved for cellulose and lignin, whereas indirect correlations were found for hemicellulose quantification. Good correspondences between the values derived from our model and those reported in the literature or obtained according to the official Van Soest method were ascertained. Average contents of 40–45% of cellulose, 2…