Validation of a Miniaturized Spectrometer for Trace Detection of Explosives by Surface-Enhanced Raman Spectroscopy

Surface-enhanced Raman spectroscopy (SERS) measurements of some common military explosives were performed with a table-top micro-Raman system integrated with a Serstech R785 miniaturized device, comprising a spectrometer and detector for near-infrared (NIR) laser excitation (785 nm). R785 was tested as the main component of a miniaturized SERS detector, designed for in situ and stand-alone sensing of molecules released at low concentrations, as could happen in the case of traces of explosives found in an illegal bomb factory, where solid microparticles of explosives could be released in the air and then collected on the sensor's surface, if placed near the factory, as a consequence of bomb preparation. SERS spectra were obtained, exciting samples in picogram quantities on specific substrates, starting from standard commercial solutions. The main vibrational features of each substance were clearly identified also in low quantities. The amount of the sampled substance was determined through the analysis of scanning electron microscope images, while the spectral resolution and the detector sensitivity were sufficiently high to clearly distinguish spectra belonging to different samples with an exposure time of 10 s. A principal component analysis procedure was applied to the experimental data to understand which are the main factors affecting spectra variation across different samples. The score plots for the first three principal components show that the examined explosive materials can be clearly classified on the basis of their SERS spectra

Laser remote sensing calibration of ocean color satellite data

world ocean: in fact, those processes dramatically affect the climatic equilibrium of our planet. For this reason, many advanced active and passive remote sensors have been used to study phytoplankton dynamics, since such phenomena are thought to be responsible for the sequestration of atmospheric carbon dioxide, one of the most important greenhouse gases. In this paper, one laser system and three satellite radiometers routinely used for the study of the phytoplankton dynamics will be briefly reviewed. Satellite sensors have been preferred to airborne sensors because, to our knowledge, ocean color airborne radiometers have not been operated in Antarctica, at least not throughout the whole lapse of time examined in this study. Particular focus was on the laser system (ELF) and on a specific satellite radiometer (SeaWiFS). ELF is based on the laser-induced fluorescence of phytoplankton pigments and was conceived for the Italian expeditions to Antarctica. The goal of SeaWiFS is to provide the Earth science community with quantitative data on the global ocean bio-optical properties. Such satellite radiometer has been calibrated with in situ data mainly acquired in non polar regions. This is why a comparison between ELF and SeaWiFS measurements of chlorophyll-a surface concentrations in the Southern Ocean during the austral summer 1997-1998 was believed to be significant. Our results indicate that SeaWiFS overestimates high concentrations and underestimates low concentrations. In order to correct this behavior, the chlorophyll- a bio-optical algorithm of SeaWiFS has been recalibrated according to the measurements of ELF, thus providing a new estimation of the primary production in the Southern Ocean

Report on LIF measurements in Seville. Part 2: Santa Ana church

A scientific cooperation between ENEA UTAPRAD (Frascati) and the Natural Sciences Department of the “Pablo de Olavide” University in Seville, has started aimed at developing and testing innovative diagnostic instrumentation for Cultural Heritage preservation. Here we report the results obtained in a joint campaign carried on in Seville during February 2010 in the Santa Ana church in Seville (SP). Several wood paintings have been thoroughly investigated by means of Laser Induced Fluorescence scan system along the lines of the Research Pro ject “Non Destructive Techniques” managed by IAPH (Consejería de Cultura de la Junta de Andalucía).The field activities, developed as part of a conservation project carried out by IPAH, were devoted to the determination of retouches, traces of former restorations and detection of chemicals (wax, consolidants, etc.) on the surface under analysis not otherwise documented

Report on LIF measurements in Seville. Part 1: Virgen del Buen Aire chapel

Within the frame of a scientific cooperation between ENEA UTAPRAD (Frascati) and UPO Natural Sciences Dep. (Seville), aimed at developing and testing innovative diagnostic instrumentation for Cultural Heritage preservation, this report deals with results obtained in a joint campaign carried on in Seville during February 2010. Namely the data acquired by the ENEA LIF scanning system operated on fresco’s in Virgen del Buen Aire Chapel are presented here. The Virgen del Buen Aire Chapel has been studied according to the Research Project of “Non Destructive Techniques” managed by IAPH (Consejería de Cultura de la Junta de Andalucía). The results have been also implemented as part of a conservation project carried out by IAPH. LIF images are discussed in term of evaluating former restoration actions, in particular retouches on pigments and consolidant additions on a painted wall and two vaults. Statistical approaches and projection operators have been utilized for elaborating the images in order to handle the large number of spectra collected in each scanned point by our hyper-spectral system

An Innovative and high-speed technology for sweater monitoring of Asinara Gulf (Sardinia- Italy)

Laser induced fluorescenze technique for sea water monitoring allows no-time consuming, non-invasive and non-destructive controls. In this study, the performance of the new shipboard laser spectrofluorometric CAS-PER (Compact and Advanced Laser Spectrometer –ENEA Patent) for monitoring phytoplankton community composition was examined. The prototype CASPER is based on double laser excitation of water samples in the UV (266 nm) and visible (405 nm) spectral region and a double water filtration in order to detect both quantitative data, such as choromophoric dissolved organic matter (CDOM), proteins-like components (tyrosine, tryptophan), algal pigments (chlorophylls a and b, phycoerythrin, phycocyanin, different pigments of the carotenoid groups) and qualitative data on the presence of hydrocarbons and oil pollutants. Sea water samples from different depths have been collected and analyzed from August 2010 through November 2011 in the Gulf of Asinara (N-W Sardinia). Several sampling stations were selected as sites with different degree of pollution. The accuracy and the reliability of data obtained by CASPER have been evaluated comparing the results with other standard measurements such as: Chlorophyll a (Chl a) data obtained by spectrophotometric method and total phytoplankton abundance in terms of density and class composition. Spectral deconvolution technique was developed and integrated with CASPER system to assess and characterize a marker pigments and organic compounds in situ and in vivo. Field studies confirmed CASPER system capability to effectively discriminate characteritistic spectra of fluorescent water constituents, contributing to decrease the time-consuming manual analysis of the water samples in the laboratory

Caratterizzazione ambientale delle acque del Golfo dell’Asinara (Sardegna) attraverso l’uso di spettrofluorimetria laser e immagini telerilevate

The general objective of this research (financed by L.R. 7 of the Autonomous Region of Sardinia for the period May 2010 –May 2012) is to calibrate bio-optical algorithm for more accurate estimates of phytoplanktonic Chl-a in the Asinara Gulf (Northern Sardinia, Italy) using remote sensing data and in situ measurements. The “sea truth” values of Chl-a were obtained with the new laser spectrofluorometric apparatus CASPER (Compact and Advanced laser SPEctrometeR – Patent ENEA). CASPER permitted not only to quantify values of Chl-a but also to detect other algal pigments (phycoerythrin, phycocyanin), chromophoric dissolved organic matter (CDOM), proteins-like components (tyrosine, tryptophan), and qualitative data on the presence of hydrocarbons and oil pollution. At the moment “sea truth” data of Chl-a were just compared to standard chlorophyll products of MODIS OC3 algorithm. In order to reach better results, the bio-optical algorithm is going to be recalibrated according to the measurements of CASPER during the next year, thus providing new estimates of phytoplanktonic Chl-a in the Asinara Gulf

Interferon regulatory factor 8-deficiency determines massive neutrophil recruitment but T cell defect in fast growing granulomas during tuberculosis

Following Mycobacterium tuberculosis (Mtb) infection, immune cell recruitment in lungs is pivotal in establishing protective immunity through granuloma formation and neogenesis of lymphoid structures (LS). Interferon regulatory factor-8 (IRF-8) plays an important role in host defense against Mtb, although the mechanisms driving anti-mycobacterial immunity remain unclear. In this study, IRF-8 deficient mice (IRF-8−/−) were aerogenously infected with a low-dose Mtb Erdman virulent strain and the course of infection was compared with that induced in wild-type (WT-B6) counterparts. Tuberculosis (TB) progression was examined in both groups using pathological, microbiological and immunological parameters. Following Mtb exposure, the bacterial load in lungs and spleens progressed comparably in the two groups for two weeks, after which IRF-8−/− mice developed a fatal acute TB whereas in WT-B6 the disease reached a chronic stage. In lungs of IRF-8−/−, uncontrolled growth of pulmonary granulomas and impaired development of LS were observed, associated with unbalanced homeostatic chemokines, progressive loss of infiltrating T lymphocytes and massive prevalence of neutrophils at late infection stages. Our data define IRF-8 as an essential factor for the maintenance of proper immune cell recruitment in granulomas and LS required to restrain Mtb infection. Moreover, IRF-8−/− mice, relying on a common human and mouse genetic mutation linked to susceptibility/severity of mycobacterial diseases, represent a valuable model of acute TB for comparative studies with chronically-infected congenic WT-B6 for dissecting protective and pathological immune reactions

Potent In Vitro Activity of Citrus aurantium Essential Oil and Vitis vinifera Hydrolate Against Gut Yeast Isolates from Irritable Bowel Syndrome Patients\u2014The Right Mix for Potential Therapeutic Use

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