82 research outputs found
SR-FTIR microscopy for the study of residues on Palaeolithic stone tools: Looking for a methodological protocol
In this paper, we use SR-FTIR microscopy to analyse residues identified on seven
lithic artefacts from the Evolved Epigravettian layer 9c2 of the cave site of Grotta Paglicci
(Apulia, southern Italy). Synchrotron radiation, thanks to its properties that particularly increase
the sensitivity of FTIR microscopy, allows the analysis of samples of microscopic size and the
characterisation of even highly degraded compounds, such as the residues of materials worked
by Palaeolithic stone tools or complex compounds used for hafting. This pilot study has been
carried out in the framework of a project concerning the reconstruction of hunting technologies
between the Middle and Upper Palaeolithic. The preliminary results allowed us to focus on the
issues of our methodological approach and to show the potential of the SR-FTIR microscopy for
the analysis of residues on lithic implements
Discovering the coating structure of historic bowed string instruments: an analytical campaign by SR-FTIR microspectroscopy
In many cases, the possibility to analyze a micro sample from an ancient bowed string instrument allows researchers to collect a wealth of information concerning materials used by the great Masters of violin-making and their construction procedures. In fact, the stratigraphic investigation may provide important information about (i) the treatments of the wood, normally involving proteinaceous materials and inorganic fillers such as carbonates, silicates, sulphates, (ii) composition of the different superimposed layers of varnish, and (iii) organic or inorganic pigments dispersed in the binders of the different superimposed layers of varnish [1].
In the present work, a set of four micro-samples - collected from well-preserved violins made by Antonio Stradivari, Francesco Ruggeri and Lorenzo Storioni - have been mounted in cross section and investigated throughout. The analytical approach has been developed on the embedded samples by means of Synchrotron Radiation (SR) FTIR microspectroscopy in reflection mode using a 15X objective, at the Chemical and Life Sciences branch of SISSI beamline (Elettra - Sincrotrone Trieste) [2]. Data have been collected in the MIR range in correspondence of each single layer of the stratigraphy, setting the lateral resolution in order to match the layer thickness (from few microns to tens of microns). A classification model has been constructed and validated to discriminate classes of materials according to the spectral information [3].
Preliminary results obtained from measurements performed by the micro-invasive SR-FTIR approach are elaborated and discussed, together with the analytical procedures, in order to characterize the features of the different samples
Ft-Ir spectroscopy and microspectroscopy of ancient egyptian embalmed heads from the Museum of Anthropology and Ethnography of the University of Turin
Fourier Transform Infrared (FT-IR) spectroscopy and microspectroscopy were used to gain insight into the state
of preservation of the skin of two Egyptian dynastic embalmed heads (VI-XI Dynasty) and one Predynastic
mummy. The mummies came from the necropoles of Asiut and Gebelein (Upper Egypt), and are curated at the
Museum of Anthropology and Ethnography of the University of Turin. The state of preservation was inferred
from the biochemical composition of the skin, in particular from the secondary structure of the proteins. The
secondary structure of the skin protein was investigated by studying the position and shape of the Amide I
band, analyzed by means of self-deconvolution techniques. The increase in the b-sheet relative amount in the
protein conformation of the mummified tissues with respect to the modern skin, was correlated with aging
processes of collagen and keratins, the most abundant proteins in the skin. The steps of the degradation processes
are hypothesized and described, and the differences in the recorded state of degradation were ascribed
to the diverse mummification procedures undergone by the studied human remains. Other non-skin-derived
features in the IR micro spectra of the embalmed specimens were detected and identified either as embalming
materials or microbial attack traces
A multidisciplinary study unveils the nature of a Roman ink of the I century AD
A multi-instrumental approach combining highly sensitive Synchrotron Radiation-based techniques was used to provide information on the real composition of a dry black ink powder found in a bronze inkwell of the first century AD. The presence of Pb, Cu and Fe in the powder, revealed by XRF and ICP-OES data, leads to raise several hypotheses on their origin. The inkpot and its lid were also investigated by Hand-Held XRF, revealing a bronze alloy (Cu-Sn) with a certain amount of Fe and Pb. The lid was found to be particularly enriched in lead. XRPD, XAS and FTIR measurements showed a substantial presence of silicates and common clay minerals in the ink along with cerussite and malachite, Pb and Cu bearing-carbonates, respectively. These evidences support the hypothesis of an important contamination of the ink sample by the burial environment (soil) and the presence of degradation products of the bronze inkpot. The combined use of IR, Raman, and GC-MS evidenced that the black ink is mainly composed of amorphous carbon deriving from the combustion of organic material mixed with a natural binding agent, Arabic gum
Morpho-chemical characterization of individual ancient starches retrieved on ground stone tools from Palaeolithic sites in the Pontic steppe
Despite the extensive literature on the retrieval of digestible starches from archaeological
contexts, there are still signifcant concerns regarding their genuine origin and durability. Here,
we propose a multi-analytical strategy to identify the authenticity of ancient starches retrieved
from macrolithic tools excavated at Upper Paleolithic sites in the Pontic steppe. This strategy
integrates the morphological discrimination of starches through optical microscopy and scanning
electron microscopy with single starch chemo-profling using Fourier transform infrared imaging and
microscopy. We obtained evidence of aging and biomineralization in the use-related starches from
Palaeolithic sites, providing a methodology to establish their ancient origin, assess their preservation
status, and attempt their identifcation. The pivotal application of this multidisciplinar approach
demonstrates that the macrolithic tools, from which starches were dislodged, were used for foodprocessing across the Pontic Steppe around 40,000 years ago during the earliest colonization of
Eurasia by Homo sapien
Evidence for B- -> Ds+ K- l- nubar and search for B- -> Ds*+ K- l- nubar
We report measurements of the decays B- -> Ds(*)+ K- l- nubar in a data
sample containing 657x10^6 BBbar pairs collected with the Belle detector at the
KEKB asymmetric-energy e+e- collider. We observe a signal with a significance
of 6 sigma for the combined Ds and Ds* modes and find the first evidence of the
B- -> Ds+ K- l- nubar decay with a significance of 3.4 sigma. We measure the
following branching fractions: BF(B- -> Ds+ K- l nubar) = (0.30 +/- 0.09(stat)
+0.11 -0.08(syst)) x 10^-3 and BF(B- -> Ds*+ K- l- nubar) = (0.59 +/-
0.12(stat) +/- 0.15(syst)) x 10^-3 and set an upper limit BF(B- -> Ds*+ K- l-
nubar) < 0.56 x 10^-3 at the 90% confidence level. We also present the first
measurement of the Ds+K- invariant mass distribution in these decays, which is
dominated by a prominent peak around 2.6 GeV/c^2.Comment: Submitted to Phys. Rev.
Adjuvant capecitabine in triple negative breast cancer patients with residual disease after neoadjuvant treatment: real-world evidence from CaRe, a multicentric, observational study
Background: In triple negative breast cancer patients treated with neoadjuvant chemotherapy, residual disease at surgery is the most relevant unfavorable prognostic factor. Current guidelines consider the use of adjuvant capecitabine, based on the results of the randomized CREATE-X study, carried out in Asian patients and including a small subset of triple negative tumors. Thus far, evidence on Caucasian patients is limited, and no real-world data are available. Methods: We carried out a multicenter, observational study, involving 44 oncologic centres. Triple negative breast cancer patients with residual disease, treated with adjuvant capecitabine from January 2017 through June 2021, were recruited. We primarily focused on treatment tolerability, with toxicity being reported as potential cause of treatment discontinuation. Secondarily, we assessed effectiveness in the overall study population and in a subset having a minimum follow-up of 2 years. Results: Overall, 270 patients were retrospectively identified. The 50.4% of the patients had residual node positive disease, 7.8% and 81.9% had large or G3 residual tumor, respectively, and 80.4% a Ki-67 >20%. Toxicity-related treatment discontinuation was observed only in 10.4% of the patients. In the whole population, at a median follow-up of 15 months, 2-year disease-free survival was 62%, 2 and 3-year overall survival 84.0% and 76.2%, respectively. In 129 patients with a median follow-up of 25 months, 2-year disease-free survival was 43.4%, 2 and 3-year overall survival 78.0% and 70.8%, respectively. Six or more cycles of capecitabine were associated with more favourable outcomes compared with less than six cycles. Conclusion: The CaRe study shows an unexpectedly good tolerance of adjuvant capecitabine in a real-world setting, although effectiveness appears to be lower than that observed in the CREATE-X study. Methodological differences between the two studies impose significant limits to comparability concerning effectiveness, and strongly invite further research
A Search for Photons with Energies Above 2X10(17) eV Using Hybrid Data from the Low-Energy Extensions of the Pierre Auger Observatory
Ultra-high-energy photons with energies exceeding 10(17) eV offer a wealth of connections to different aspects of cosmic-ray astrophysics as well as to gamma-ray and neutrino astronomy. The recent observations of photons with energies in the 10(15) eV range further motivate searches for even higher-energy photons. In this paper, we present a search for photons with energies exceeding 2 x 10(17) eV using about 5.5 yr of hybrid data from the low-energy extensions of the Pierre Auger Observatory. The upper limits on the integral photon flux derived here are the most stringent ones to date in the energy region between 10(17) and 10(18) eV
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