排序方式： 共有131条查询结果，搜索用时 234 毫秒
61.
Zavgorodnyaya Yuliya A. Chikidova Aleksandra L. Biryukov Mikhail V. Demin Vladimir V. 《Journal of Soils and Sediments》2019,19(8):3155-3165
Purpose
The study was conducted to quantify the polycyclic aromatic hydrocarbons (PAHs) accumulation in urban soils from different functional areas via atmospheric inputs with particulate matter.
Materials and methodsPAH concentration and pattern were measured in the particulate matter of snow depositions, in the upper layers of artificial soils from densely built-up areas and in the undisturbed natural soils (Umbric Retisols) from green park area. Samples were collected in 2011–2013 at 58 sites with different traffic activities located at the territory of the Eastern Administrative Okrug of Moscow. The soil samples and filters with particulate matter were extracted by pressurized liquid extraction using Dionex ASE200. Clean-up analyses were performed on SPE cartridges filled with silica gel. Concentrations of PAHs were determined by high-performance liquid chromatography using an Agilent 1100 System equipped with fluorescent detector.
Results and discussionMean values of PAH input with snow particles were 45–57 μg/m2 for recreational and residential zones, and 140–264 μg/m2 for traffic zones. The samples of depositions from different functional areas showed a similar PAH pattern and consisted primarily of 3–4-ring PAHs. Total PAH concentrations in upper layers of artificial soils showed similar mean values of 1.43–2.21 μg/g for all functional zones. The PAH content in soils from the park area was twofold lower than that from the built-up area (0.34–0.63 μg/g), despite equal levels of atmosphere contamination on these territories. The upper layers of natural soils from recreational and traffic zones showed slight differences in PAH content, though PAH input with snow was fivefold higher in the traffic zone. Compared with airborne depositions, soils contained significant amounts of 5–6-ring PAHs.
ConclusionsA high level of soil PAH contamination in urban areas of Moscow, several orders of magnitude higher than the current PAH input to them from the atmosphere, indicates a lack of direct connection of the PAH pool in soils with this source. The high PAH content in the upper layer of constructed soils can be the result of repeated use of materials subjected to a constant technogenic impact for the production of artificial soils.
相似文献62.
Aleksandra V. Volod&#x;ko Viktoriya N. Davydova Valentina A. Petrova Dmitry P. Romanov Evgeniya A. Pimenova Irina M. Yermak 《Marine drugs》2021,19(12)
The influence of the structural features of carrageenan on the functional properties of the films was studied. The carrageenans and chitosan films, as well as three-layer films containing a polyelectrolyte complex (PEC) of the two, were prepared. The X-ray diffractograms of carrageenan films reflected its amorphous structure, whereas chitosan and three-layer films were characterized by strong reflection in the regions of 20° and 15° angles, respectively. The SEM of the cross-sectional morphology showed dense packing of the chitosan film, as well as the layer-by-layer structure of different densities for the PEC. Among the tested samples, κ/β-carrageenan and chitosan films showed the highest tensile strength and maximum elongation. Films containing the drug substance echinochrome were obtained. Mucoadhesive properties were assessed as the ability of the films to swell on the mucous tissue and their erosion after contact with the mucosa. All studied films exhibited mucoadhesive properties. All studied films exhibited mucoadhesive properties which depended on the carrageenans structure. Multilayer films are stronger than single-layer carrageenan films due to PEC formation. The resulting puncture strength of the obtained films was comparable to that of commercial samples described in the literature. 相似文献
63.
Aleksandra Daskalova 《International Aquatic Research》2019,11(2):113-124
Over the past few decades, a considerable scientific progress has been achieved in the area of fish welfare at all stages—farming, transportation, various pre-slaughter manipulations, stunning/killing procedures, etc. The increasing scientific interest is mainly due to the serious need of developing and implementing specific fish welfare requirements across the whole chain for both ethical (welfare) and commercial (meat quality) reasons. Since there has been substantial evidence that fish are able to experience pain and suffering, the provoked stress response could be a major cause of altered post-mortem metabolism and impaired meat quality. The present review was aimed to present the relationship between ante-mortem stress, course of post-mortem metabolic processes and the potential alterations in some quality traits of fish for human consumption. 相似文献
64.
Simon J.G. Otto Margaret Haworth-Brockman Misha Miazga-Rodriguez Aleksandra Wierzbowski Lynora M. Saxinger 《The Canadian veterinary journal. La revue veterinaire canadienne》2022,63(2):161
Objective Integrated surveillance of antimicrobial resistance (AMR) and antimicrobial use (AMU) across One Health sectors is critically important for effective, evidence-based policy, stewardship, and control of AMR. Our objective was to evaluate progress towards achieving comprehensive, integrated AMR/AMU surveillance in Canada.Materials and methods Based on an environmental scan, interviews of subject matter experts, and reports from the 2014 National Collaborating Centre for Infectious Diseases and the 2016 Canadian Council of Chief Veterinary Officers, we identified 8 core surveillance requirements and their specific components; the latter were assessed using a 2-way classification matrix, with 7 common elements ranked according to development stage.Results Components that mapped to requirements of a comprehensive, fully integrated AMR/AMU surveillance system were mostly in the lowest stages of development (Exploration or Program Adoption). However, both the establishment of the Canadian AMR Surveillance System integrated reporting and expansion of existing components under the Canadian Nosocomial Infection Surveillance Program and the Canadian Integrated Program for AMR Surveillance are improvements. Regardless, obvious gaps in Canadian AMR/AMU surveillance prevent this from being a comprehensive and integrated One Health program.Conclusion Action is needed in 3 crucial areas: i) development of a complete, integrated AMR/AMU surveillance program, based on current success; ii) changes in Federal/Provincial/Territorial policies to require standardized AMR/AMU reporting; and iii) more resources for AMR/AMU surveillance (dedicated persons, funding, and enabling structures and policy). There is an urgent need for prioritization by Federal/Provincial/Territorial governments to address governance, leadership, and funding to create surveillance systems that inform stewardship and policy. 相似文献
65.
66.
Sanja Marković Slaviša Stanković Renata Iličić Sonja Veljović Jovanović Sonja Milić Komić Aleksandra Jelušić Tatjana Popović 《Plant pathology》2021,70(8):1945-1959
Since 2011, the outbreaks of brown rot caused by Ralstonia solanacearum race 3, biovar 2, phylotype IIB-1 (R3/B2/PIIB-1) have significantly compromised potato production in Serbia. During 6 years of monitoring (2013–2018) among 3,524 potato tuber samples, 344 were found positive for brown rot disease. R. solanacearum R3/B2/PIIB-1 was isolated from seven cultivars among 12 monitored, and in five localities among 17 monitored. Cultivar Lady Claire was found to have the highest disease frequency (31.98%). A total of 78 isolates were identified by R. solanacearum-specific primer pairs (PS-1/PS-2 and OLI-1/Y-2), as well as the following tests: restriction fragment length polymorphism analysis, biovar determination, immunofluorescence, biochemical analysis, and pathogenicity. The genetic composition of 36 selected isolates assessed using multilocus sequence analysis with seven genes (adk, gapA, gdhA, gyrB, ppsA, hrpB, and fliC) showed that all isolates originating from Serbian potato were homogeneous. By using the TCS algorithm of concatenated sequences to get insight into the phylogeography of isolates and other R. solanacearum strains deposited in the NCBI database, we showed that their origin is undetermined. Peroxidase (POD) activity was measured in brown rotted potato tubers. A positive correlation was found between POD activity and disease severity rated on the analysed tubers. In general, POD activity increased by 2–22 times in vascular necrotic tissues compared to non-necrotic ones, and depended on disease severity but not on cultivar. Native polyacrylamide gel electrophoresis analysis of POD profiles resulted in a total of 10 distinct POD isoforms, of which PODs 3–5 were highly intensified in response to R. solanacearum. 相似文献
67.
Kristo AS Kalea AZ Schuschke DA Klimis-Zacas DJ 《Journal of agricultural and food chemistry》2010,58(22):11600-11605
The effect of a wild blueberry-enriched diet on vasoconstriction and vasorelaxation was examined in the adult, 20-week-old spontaneously hypertensive rat (SHR) after 8 weeks of a control (C) or an 8% wild blueberry (WB) diet. Nitric oxide (NO)- and cyclooxygenase (COX)-mediated aortic responses were examined ex vivo with the agonists L-phenylephrine (Phe) and acetylcholine (Ach), in the absence or presence of the NO synthase (NOS) inhibitor L-NG-monomethyl arginine (L-NMMA) or the COX inhibitor mefenamic acid (MFA). The vasoconstriction elicited by Phe was reduced in the WB group, attributed to the NO pathway, favoring a lower vascular tone under basal conditions. Acetylcholine-induced vasorelaxation in the WB group was possibly mediated through the COX, but not the NO pathway. These findings document the potential of wild blueberries to modify major pathways of vasomotor control and improve the vascular tone in the adult SHR with endothelial dysfunction. 相似文献
68.
69.
A galvanostatic stripping chronopotentiometric (GSCP) method for the simultaneous determination of cadmium, lead, and copper in commercial margarines and butters is described. Quantitative analyses of heavy metals in the mineralized fat samples, except standard addition method, were carried out automatically. The mean concentrations of Cd(II), Pb(II), and Cu(II) in different types of margarines and butters varied from 9.1 to 26.2, 9.2-14.2, 298.2-364.0 microg x kg(-)(1), respectively, that is below the legal requirements. The detection limits are 0.02, 0.02, and 0.06 microg x L(-)(1) for Cd(II), Pb(II) and Cu(II), while the reproducibilities are 3.3, 5.7, and 2.0%, respectively. The comparable precision (RSD = 0.76-4.5 and 0.87-4.9%) and recovery (96.7-102.2% and 96.1-103.2%) for the proposed GSCP and standard GFAAS methods, demonstrate the benefit of GSCP method in the routine analysis of heavy metal ions in fats. 相似文献
70.
Stojadinović Sanja Šajnović Aleksandra Kašanin-Grubin Milica Gajica Gordana Veselinović Gorica Štrbac Snežana Jovančićević Branimir 《Journal of Soils and Sediments》2022,22(2):640-655
Journal of Soils and Sediments - The Great War Island (GWI) is a landform of exceptional features and a protected area located in the center of Belgrade at the Sava and Danube River’s... 相似文献