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Benzene is known to be toxic and carcinogenic: therefore, in case of exposure to benzene vapours, a reliable biological monitoring procedure is needed, particularly in the field of occupational hygiene. The determination of the concentration of benzene in the exhaled air 8 h after the exposure has been demonstrated to be a significant biomarker, even for low concentrations of airborne benzene vapours. This work presents a sampling and analysis method that optimizes previously described procedures: in the sampling phase, a double-step sample collection in Tedlar bags is used, in order to remove the breath moisture and to standardise the sample volumes. The analytical phase uses a cryogenic trap for the concentration of the air samples to be injected in the GC-MS, without the need for trapping materials, significantly reducing time and costs of the analysis and improving sensitivity. The presented method has been successfully applied to the biological monitoring of a mixed population (occupationally exposed and not exposed subjects, smokers and non-smokers), with a lower detection limit of 1.5 ng of benzene per litre of exhaled air, that is 1/200 of the biological exposure index recommended by the American Conference of Governmental Hygienists. 相似文献
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Costa M Cà ND Gabriele B Massera C Salerno G Soliani M 《The Journal of organic chemistry》2004,69(7):2469-2477
An effective and straightforward approach to the synthesis of 4H-3,1-benzoxazines 3 and 4, quinazolin-2-ones 5, and quinoline-4-one derivatives 6 and 7 is provided by palladium-catalyzed cyclization-alkoxycarbonylation of variously substituted 2-(trimethylsilanyl)ethynylaniline amide or urea derivatives 2. Reactions are carried out in 7:1 MeCN/MeOH at 65 or 75 degrees C in the presence of catalytic amounts of 10% Pd/C in conjunction with Bu(4)NI and KF and under 2.4 MPa of a 3:1 mixture of CO and air. Anti and syn 6-exo-dig cyclization modes account for the formation of the two stereoisomers. Isomerization of the vinylpalladium intermediate may occur as well. Formation of a double carbonylation product 7r and of a gem-dimethoxycarbonylation product 6s, whose structures have been determined by X-ray diffraction analysis, is justified through an unusual type of rearrangement. 相似文献
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LoSecco JM Bionta RM Biewitt G Bratton CB Casper D Chrysicopoulou P Claus R Cortez BG Errede S Foster GW Gajewski W Ganezer KS Goldhaber M Haines TJ Jones TW Kielczewska D Kropp WR Learned JG Lehmann E Park HS Reines F Schultz J Seidel S Shumard E Sinclair D Sobel HW Stone JL Sulak L Svoboda R van der Velde JC Wuest C 《Physical review letters》1985,54(21):2299-2301
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B. A. Bolton M. A. Salerno Ph. K. Hopke 《Journal of Radioanalytical and Nuclear Chemistry》1974,23(1-2):189-194
In a study conducted in 1971, levels of tritium were found in Cattaraugus-Creek, a stream in Western New York State. This material was attributed to the operation in West Valley, New York of the world's first commercial nuclear fuels reprocessing plant. Several fission fragment isotopes in addition to tritium were also observed in Buttermilk Creek, one of the tributaries of Cattaraugus Creek that runs through the reprocessing plant grounds. The plant ceased processing nuclear fuel in December 1971, and a new set of measurements in these streams were made to assess the effect of the ending of the plant's operation. Substantially lower concentrations of tritium and no fission produced isotopes have been observed. 相似文献
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Giampaolo Primofiore Anna Maria Marini Federico Da Settimo Silvia Salerno Daniele Bertini Lisa Dalla Via Sebastiano Marciani Magno 《Journal of heterocyclic chemistry》2003,40(5):783-788
The synthesis of new planar derivatives characterized by the presence of a pyridothiopyranopyrazole or pyridothiopyranopyrimidine nucleus, carrying a substituted aryl group, is reported. The novel 1,4‐dihydropyrido[3′,2′:5,6]thiopyrano[4,3‐c]pyrazole derivatives were obtained by condensation of 2,3‐dihydro‐3‐hydroxymethylenethiopyrano[2,3‐b]pyridin‐4(4H)‐ones with appropriate hydrazines. The preparation of 2‐substituted pyrido[3′,2′:5,6]thiopyrano[4,3‐d]pyrimidines was accomplished from the intermediate 2,3‐dihy‐dro‐3‐dimethylaminomethylenethiopyrano[2,3‐b]pyridin‐4(4H)‐ones by reaction with the appropriate binucleophile amidines. The antiproliferative activity of some new products was tested by an in vitro assay on human tumour cell lines (HL‐60 and HeLa), but none of them showed any significant effects in the tests performed. Accordingly, linear flow dichroism measurements indicated their inability to form a molecular complex with DNA. 相似文献
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The thermal behaviour of (n-CaH2n+1NH2)2ZnCl2 complexes with n = 6, 8, … 16 has been investigated by DSC and by temperature variable IR and X-ray powder diffraction techniques. Complexes with n = 12,14,16 show solid—solid phase transition which are “melting” transitions of the hydrocarbon regions of the structure. The crystal structure of both the low and the high temperature polymorphs is characterized by the piling of sandwiches, each formed by an “inorganic” layer sandwiched between two alkylammonium layers. 相似文献
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