Comparison of codes assessing galactic cosmic radiation exposure of aircraft crew

The assessment of the exposure to cosmic radiation onboard aircraft is one of the preoccupations of bodies responsible for radiation protection. Cosmic particle flux is significantly higher onboard aircraft than at ground level and its intensity depends on the solar activity. The dose is usually estimated using codes validated by the experimental data. In this paper, a comparison of various codes is presented, some of them are used routinely, to assess the dose received by the aircraft crew caused by the galactic cosmic radiation. Results are provided for periods close to solar maximum and minimum and for selected flights covering major commercial routes in the world. The overall agreement between the codes, particularly for those routinely used for aircraft crew dosimetry, was better than ±20 % from the median in all but two cases. The agreement within the codes is considered to be fully satisfactory for radiation protection purpose

Morphological and Geochemical Evidence of Eumelanin Preservation in the Feathers of the Early Cretaceous Bird, Gansus yumenensis

Recent studies have shown evidence for the preservation of colour in fossilized soft tissues by imaging melanosomes, melanin pigment containing organelles. This study combines geochemical analyses with morphological observations to investigate the preservation of melanosomes and melanin within feathers of the Early Cretaceous bird, Gansus yumenensis. Scanning electron microscopy reveals structures concordant with those previously identified as eumelanosomes within visually dark areas of the feathers but not in lighter areas or sedimentary matrices. Fourier transform infrared analyses show different spectra for the feathers and their matrices; melanic functional groups appear in the feather including carboxylic acid and ketone groups that are not seen in the matrix. When mapped, the carboxylic acid group absorption faithfully replicates the visually dark areas of the feathers. Electron Paramagnetic Resonance spectroscopy of one specimen demonstrates the presence of organic signals but proved too insensitive to resolve melanin. Pyrolysis gas chromatography mass spectrometry shows a similar distribution of aliphatic material within both feathers that are different from those of their respective matrices. In combination, these techniques strongly suggest that not only do the feathers contain endogenous organic material, but that both geochemical and morphological evidence supports the preservation of original eumelanic pigment residue

Wall fluxes of reactive oxygen species of an rf atmospheric-pressure plasma and their dependence on sheath dynamics

This article was published in the serial, Journal of Physics D: Applied Physics [© IOP Publishing Ltd]. The definitive version is available at: http://dx.doi.org/10.1088/0022-3727/45/30/305205A radio-frequency (rf) atmospheric-pressure discharge in He–O2 mixture is studied using a fluid model for its wall fluxes and their dependence on electron and chemical kinetics in the sheath region. It is shown that ground-state O, O+2 and O− are the dominant wall fluxes of neutral species, cations and anions, respectively. Detailed analysis of particle transport shows that wall fluxes are supplied from a boundary layer of 3–300μm immediately next to an electrode, a fraction of the thickness of the sheath region. The width of the boundary layer mirrors the effective excursion distance during lifetime of plasma species, and is a result of much reduced length scale of particle transport at elevated gas pressures. As a result, plasma species supplying their wall fluxes are produced locally within the boundary layer and the chemical composition of the overall wall flux depends critically on spatio-temporal characteristics of electron temperature and density within the sheath. Wall fluxes of cations and ions are found to consist of a train of nanosecond pulses, whereas wall fluxes of neutral species are largely time-invariant

Colombo Focus City Project : data brief; 2009 quarter 1

This Data Brief focuses on perceptions of wellbeing of Under-served Settlement (USS) households as well as income and expenditure patterns, and satisfaction regarding access to existing service provision. It provides an introduction to the Baseline Survey sampling, providing information on environmental burdens that are linked to limited service provision, including sewerage and solid waste management facilities and their impact on poverty. The Colombo (Sri Lanka) study uses water and sanitation as an entry-point to develop a model of participatory service provision that addresses how best to deliver different types of urban services to the urban poor

La Patrie : journal quotidien, politique, commercial et littéraire

06 janvier 18691869/01/06 (A29)

Evaluation of angularly condensed diquinothiazines as potential anticancer agents

© 2019 We present efficient synthesis of isomeric types of angularly fused diquinothiazines in the reactions of 2,2′-dichloro-3,3′-diquinolinyl disulfide and diquinodithiin with 3-, 5-, 6- and 8-aminoquinolines. The pentacyclic diquinothiazine ring systems were identified as diquino[3,2-b;3′,4′-e][1,4]thiazine, diquino[3,2-b;5′,6′-e][1,4]thiazine, diquino[3,2-b;6′,5′-e][1,4]thiazine and diquino[3,2-b;8′,7′-e][1,4]thiazine with advanced two-dimensional 1 H and 13 C NMR techniques (COSY, ROESY, HSQC and HMBC) of N-methyl derivatives. The identification of pentacyclic ring system was confirmed by X-ray diffraction analysis of selected N-alkyl derivatives. The X-ray analysis revealed different spatial structures of the ring system (planar and folded). NH-diquinothiazines were further transformed into N-alkyl and N-dialkylaminoalkyl derivatives. Most of diquinothiazines exhibited significant cancer cell growth inhibition against the human glioblastoma SNB-19, colorectal carcinoma Caco-2, breast cancer MDA-MB-231 and lung cancer A549 cell lines with the IC 50 values < 3 µM. This anti-proliferative activity was found to be more than for cisplatin. The most promising compound, 7-dimethylaminopropyldiquino[3,2-b;6′,5′-e]thiazine, was used for gene expression analysis by reverse transcription–quantitative real-time PCR (RT–QPCR) method. The expression of H3, TP53, CDKN1A, BCL-2 and BAX genes revealed that this compound inhibited the proliferation in all cells (H3) and activated mitochondrial events of apoptosis (BAX/BCL-2) in two cancer cell lines (SNB-19 and Caco-2)

Evaluation of angularly condensed diquinothiazines as potential anticancer agents

© 2019 We present efficient synthesis of isomeric types of angularly fused diquinothiazines in the reactions of 2,2′-dichloro-3,3′-diquinolinyl disulfide and diquinodithiin with 3-, 5-, 6- and 8-aminoquinolines. The pentacyclic diquinothiazine ring systems were identified as diquino[3,2-b;3′,4′-e][1,4]thiazine, diquino[3,2-b;5′,6′-e][1,4]thiazine, diquino[3,2-b;6′,5′-e][1,4]thiazine and diquino[3,2-b;8′,7′-e][1,4]thiazine with advanced two-dimensional 1 H and 13 C NMR techniques (COSY, ROESY, HSQC and HMBC) of N-methyl derivatives. The identification of pentacyclic ring system was confirmed by X-ray diffraction analysis of selected N-alkyl derivatives. The X-ray analysis revealed different spatial structures of the ring system (planar and folded). NH-diquinothiazines were further transformed into N-alkyl and N-dialkylaminoalkyl derivatives. Most of diquinothiazines exhibited significant cancer cell growth inhibition against the human glioblastoma SNB-19, colorectal carcinoma Caco-2, breast cancer MDA-MB-231 and lung cancer A549 cell lines with the IC 50 values < 3 µM. This anti-proliferative activity was found to be more than for cisplatin. The most promising compound, 7-dimethylaminopropyldiquino[3,2-b;6′,5′-e]thiazine, was used for gene expression analysis by reverse transcription–quantitative real-time PCR (RT–QPCR) method. The expression of H3, TP53, CDKN1A, BCL-2 and BAX genes revealed that this compound inhibited the proliferation in all cells (H3) and activated mitochondrial events of apoptosis (BAX/BCL-2) in two cancer cell lines (SNB-19 and Caco-2)

Application of the Chemical Oxygen Demand (COD) method for determining the amount of lecithin in synthetic hydroxyapatite

Badania dotyczyły zastosowania metody Chemicznego Zapotrzebowania Tlenu (ChZT) do oznaczenia ilości lecytyny związanej z hydroksyapatytem (HAp-LE), otrzymanym w procesie chemicznej precypitacji. Dokładność metody zweryfikowano wykonując bilans tlenu zużytego do całkowitego utlenienia lecytyny zawartej w mieszanie poreakcyjnej, osadzie oraz supematancie. Zawartość lecytyny w proszkach mieściła się w granicach od 1% do 30%. Zaproponowana metoda analityczna może być wykorzystywana do oznaczenia innych dodatków organicznych związanych z syntetycznym HAp.The research concerned the application of the Chemical Oxygen Demand (COD) method lor determining the amount of lecithin bonded with hydroxyapatite (HAp-LE) obtained in the wet chemical precipitation process. The accuracy of method was verified using a balance of oxygen consumed to completely oxidize the lecithin contained in post-reaction mixture, precipitate and supernatant. The content of lecithin in obtained powders ranged from 1% to 30%. The proposed analytical method can be used in the determination of other organie additives bonded with synthetic HAp