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891.
Ana Luísa Pinto Paula Teixeira Fernanda Castilho Maria Teresa Felício Filomena Pombal & Paul A Gibbs 《Aquaculture Research》2006,37(11):1112-1116
The prevalence and contamination levels of Listeria monocytogenes were investigated in live bivalve molluscs for human consumption, collected in various steps of the commercial and sanitary circuits in the North of Portugal. Samples of different species were collected per lot before and after depuration treatment in two depuration units and further, when placed in retail markets. Listeria monocytogenes was isolated from 4% of the samples although with very low contamination levels (less than 100 MPN g?1). None of the environmental (non‐depurated) samples were contaminated with the food‐borne pathogen. The positive samples involved depurated and commercialized samples from two lots, one in each circuit. Two serotypes (1/2a and 3b) were detected among the isolated strains. This study demonstrated the possibility of occurrence of L. monocytogenes contamination of live bivalve molluscs along the sanitary control circuit, including at the retail market level. As L. monocytogenes grows well at refrigerated temperatures and in high salt matrixes such as seafood its presence in these products should not be overlooked. 相似文献
892.
Gilbert MT Tomsho LP Rendulic S Packard M Drautz DI Sher A Tikhonov A Dalén L Kuznetsova T Kosintsev P Campos PF Higham T Collins MJ Wilson AS Shidlovskiy F Buigues B Ericson PG Germonpré M Götherström A Iacumin P Nikolaev V Nowak-Kemp M Willerslev E Knight JR Irzyk GP Perbost CS Fredrikson KM Harkins TT Sheridan S Miller W Schuster SC 《Science (New York, N.Y.)》2007,317(5846):1927-1930
Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has revolutionized the study of ancient DNA, it has been plagued by large fractions of contaminating environmental DNA. The genetic analyses of hair shafts could be a solution: We present 10 previously unexamined Siberian mammoth (Mammuthus primigenius) mitochondrial genomes, sequenced with up to 48-fold coverage. The observed levels of damage-derived sequencing errors were lower than those observed in previously published frozen bone samples, even though one of the specimens was >50,000 14C years old and another had been stored for 200 years at room temperature. The method therefore sets the stage for molecular-genetic analysis of museum collections. 相似文献
893.
Anderson TM Neiwert WA Kirk ML Piccoli PM Schultz AJ Koetzle TF Musaev DG Morokuma K Cao R Hill CL 《Science (New York, N.Y.)》2004,306(5704):2074-2077
Terminal mono-oxo complexes of the late transition metal elements have long been considered too unstable to synthesize because of repulsion between the oxygen electrons and the mostly filled metal d orbitals. A platinum(IV)-oxo compound flanked by two polytungstate ligands, K7Na9[O=Pt(H2O)L2], L = [PW9O34(9-)], has now been prepared and isolated at room temperature as air-stable brown crystals. X-ray and neutron diffraction at 30 kelvin revealed a very short [1.720(18) angstrom] Pt-O bond and no evidence of a hydrogen atom at the terminal oxygen, ruling out a better precedented Pt-OH complex. Density functional theory and spectroscopic data account for the stability of the Pt(IV)-oxo unit by electron withdrawal into delocalized orbitals of the polytungstates. 相似文献
894.
Marco Antonio León-Romero Paula Cecilia Soto-Ríos Munehiro Nomura Osamu Nishimura 《Water, air, and soil pollution》2018,229(1):12
After the tsunami caused by the Great East Japan Earthquake, marine sediment was taken from the sea bottom and deposited over local agricultural fields. The marine sediment already contained an unknown amount of heavy metals, due to anthropogenic activities prior to the tsunami, which might affect plants, animals, and humans. Furthermore, soil salinity in tsunami-inundated land greatly increased. Three different amounts of steel slag were employed as pretreatment agent in order to improve agricultural soil quality. The soil samples treated with 2% of steel slag present a remarkable increase of A. thaliana biomass production with low BCF and TF values for most of the heavy metals. It was concluded that steel slag pretreatment used in the tsunami-inundated agricultural lands produced a noteworthy improvement in soil quality which lead to a positive stimulative effect on plant growth, and the slag addition treatment proved to be a promising treatment that might be used for phytostabilization of slightly contaminated soils. 相似文献
895.
Cardiac‐gated,phase contrast magnetic resonance angiography is a reliable and reproducible technique for quantifying blood flow in canine major cranial abdominal vessels 下载免费PDF全文
Francesca Del Chicca Andrea Schwarz Paula Grest Florian Willmitzer Matthias Dennler Patrick R. Kircher 《Veterinary radiology & ultrasound》2018,59(4):423-431
Blood flow changes in cranial abdominal vessels are important contributing factors for canine hepatic disease. This prospective, experimental, pilot study aimed to evaluate cardiac‐gated, phase contrast magnetic resonance angiography (PCMRA) as a method for characterizing blood flow in canine major cranial abdominal vessels. Eleven, healthy, adult beagle dogs were sampled. Cardiac‐gated, phase contrast magnetic resonance angiography of the cranial abdomen was performed in each dog and blood flow was independently measured in each of the major cranial abdominal vessels by three observers, with two observers recording blood flow values once and one observer recording blood flow values three times. Each dog then underwent ultrasonographic examination of the liver with fine needle aspirations and biopsies submitted to cytologic and histologic examination. The mean absolute stroke volume and velocity were respectively 9.6 ± 1.9 ml and –11.1 ± 1.1 cm/s for the cranial abdominal aorta, 2.1 ± 0.6 ml and –6.6 ± 1.9 cm/s for the celiac artery, and 2.3 ± 1.0 ml and –7.9 ± 3.1 cm/s for the cranial mesenteric artery. The mean absolute stroke volume and velocity were respectively 6.7 ± 1.3 ml and 3.9 ± 0.9 cm/s for the caudal vena cava and 2.6 ± 0.9 ml and 3.2 ± 1.2 cm/s for the portal vein. Intraobserver reliability was excellent (intraclass correlation coefficient > 0.9). Interobserver reproducibility was also excellent (intraclass correlation coefficient 0.89–0.99). Results of liver ultrasonography, cytology, and histopathology were unremarkable. Findings indicated that cardiac‐gated, phase contrast magnetic resonance angiography is a feasible technique for quantifying blood blow in canine major cranial abdominal vessels. Blood flow values from this sample of healthy beagles can be used as background for future studies on canine hepatic disease. 相似文献