首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7篇
  免费   0篇
口腔科学   1篇
内科学   1篇
特种医学   1篇
预防医学   2篇
药学   2篇
  2022年   1篇
  2016年   2篇
  2014年   1篇
  2009年   2篇
  2004年   1篇
排序方式: 共有7条查询结果,搜索用时 15 毫秒
1
1.
In the present contribution the possibilities and drawbacks of two analytical strategies based on the use of low power X-ray fluorescence systems (EDXRF and μ-XRF) have been explored for rapid multielemental analysis and chemical imaging of different edible vegetal species. The proposed methodologies allow analysis of vegetation material without complex sample treatments providing relevant advantages in terms of simplicity and costs compared to classical destructive methods. As study cases, we have focused on the analysis of different parts of several vegetal species (Daucus carota, Spinacia oleracea, Cynara scolymus, Raphanus staivus, Coriandrum sativum) collected in agricultural soils irrigated with municipal treated wastewater samples. EDXRF and μ-EDXRF data revealed that content of some major elements such as P and S increased if crops are irrigated with municipal treated wastewater although the distribution of these elements is not depending of the type of water used for irrigation purposes. On the contrary, trace element content is not significantly higher in comparison to vegetables irrigated with fresh water, except for bromine. The findings of this contribution can contribute to expand the knowledge about the impact of the use of reclaimed wastewaters for irrigation on vegetal composition but the use of the aforementioned XRF techniques could be also extended to other food safety and nutritional studies.  相似文献   
2.
口腔内金属修复物的成分分析   总被引:4,自引:0,他引:4  
目的:测定口腔内金属修复物的成分,确定使用的合金种类,以使牙科金属过敏患者避免再次使用此种合金。方法:用细砂纸及圆锥形抛光磨头,采取微量口腔内金属修复物,通过EDXRF(荧光X线分析仪)测定所含金属成分,确定合金种类。结果:14例可疑牙科金属过敏患者中,牙科金属修复物120个,按照检出频度的高低.排在前10位的金属元素分别是Ag、Cu、Au、Pd、Zn、Sn、Co、Cr、In和Mo。Au-Ag-Pd合金的使用频度为65%,Ag-Sn-Hg合金为2.5%,Ag合金为5.4%,Au合金为14.6%,Ni-Cr、Co-Cr合金为10.1%,其他2.4%。2种以上异种合金共存同一口腔环境中的患者12例,5种合金同时存在者1例。含Hg的银汞合金的使用频度为2.5%,与10年前的使用频度16%相比下降明显。Ni、Cr、Co的使用频度未见明显改变。结论:被疑牙科金属过敏的患者中,异种金属同存的现象严重,提示在口腔科临床工作中,尽量避免使用异种金属及含Hg和Ni等易诱发过敏的金属合金。  相似文献   
3.
The brown crab Cancer pagurus is highly appreciated in Southern European countries and edible tissues are consumed separately or as mixtures. This species is mostly harvested along the Scottish Coast and English Channel and has different market prices depending on the catching area and sex. The aim of this study was to quantify and characterize the contents of S, As, Br, Sr, Cd, Hg and Pb in muscle, hepatopancreas, gonads and gills of female and male crabs from both catching areas. Additionally, the accumulation patterns were evaluated according to hazards for human consumption and from an ecological point of view. Crabs caught off the Scottish Coast had more S and As (gonads), while specimens from the English Channel showed more Cd (gonads) and Br (gonads, muscle). The elemental bioavailability and physiological needs likely explain these differences. Independently of catching area and sex, brown crabs’ muscle and gonads are safe food items as far as contaminants are concerned. Yet, Cd in hepatopancreas was always above the level set by international regulating organizations. Consequently, future risk assessment studies should evaluate Cd concentration in all edible tissues of crustaceans prior to the extensive use of processed tissues in food products.  相似文献   
4.
The Sardinian protohistoric civilisation (Final Bronze Age and the Early Iron Age) has greatly contributed to the development of metallurgy in the Mediterranean area by producing a large number of bronze artefacts. Among them, small boat models (so-called “navicelle”) represent one of the most characteristic objects from the Sardinian Protohistoric civilisation. This work is an attempt to classify these boats on the basis of their alloy composition, provenience, and morphology. Due to the impossibility of removing the boats from the museum, alloys were characterised using energy-dispersive X-ray fluorescence spectrometry and Monte Carlo simulations. Fifteen boats were analyzed. Obtained results were compared to other performed analyses in the last few decades with different techniques and reported in the literature. Analyses allow for characterising both the bulk composition of ternary alloy Cu–Sn–Pb and patina thickness, offering useful information about their conservation status and the technological achievements of Sardinian craftsmen, while also providing information on smelting temperatures and casting techniques.  相似文献   
5.
The presented work uses stable isotope ratios of major bioelements (13C/12C, 15N/14N, 18O/16O, 34S/32S) and elemental composition to determine the regional provenance of 124 Slovenian milk and 30 cheese samples collected during May, June and July in 2012 and 2013. The ability to discriminate between cow milk based on geographical origin was only possible in summer 2012, where discriminant analysis identified Cl, Zn, P, Ca and K as the most significant parameters. Both sheep milk and cheese could be distinguished according to their geographical origin based on P, S, K, Cl, Ca, Zn content and δ13C and δ15N values in casein and to refuse possible imitations with a correct classification in 97% of cases. Furthermore, stable isotopes of light elements in combination with elemental composition can distinguish sheep and goat milk and cheese from that produced from cow milk with a prediction ability of 95.2%. Such methodology can effectively contribute towards supporting the existence of the Protected Designated Origin of Bovški and Kraški sheep cheese and Tolminc cow cheese and could be incorporated into a traceability system.  相似文献   
6.
A total of 18 elements viz. Si, Al, Fe, Ca, Mg, K, Na, Sr, V, Zn, Mn, Cr, Cu, Pb, Ni, Co, As and Cd were analyzed in coal, fly ash and bottom ash samples collected across India using an EDXRF technique. Various indices such as element enrichment ratio, enrichment factor (with respect to crustal average) and mineral composition were calculated. Around 95% of mass was reconstructed using the concentration of elements in this study for fly and bottom ash.  相似文献   
7.
Concentrations of 10 elements were studied from the pre-moult hard shelled and newly moulted (soft shelled) crabs (Scylla serrata) by the (Energy Dispersive X-ray Fluorescence) EDXRF technique. The study evaluated the composition of all 10 elements from the body tissues and the exuvium of soft shelled and the carapace of pre-moulted hard-shelled crabs in order to evaluate the food value from nutritional and safety point of view for human consumption. The essential elements like K, Ca, Mn, Cu, etc., get reabsorbed from the carapace to the body tissues in order to meet the further requirement in the soft shelled crabs and are also utilized to some extent during the formation of new carapace, toxic element like Pb gets excreted during exuviation and element like Zn gets regulated, as and when become higher in bioavailable form. This study gives evidence that, the freshly moulted soft shelled crabs are more safe and nutritious than the hard-shelled crabs.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号