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  • 文章类型: Journal Article
    Molecular absorption spectrometry (MAS), originally developed in the 1970s, is a technique to determine non-metals in flames and graphite furnaces by monitoring the absorbance of diatomic molecules. Early studies employed low resolution instruments designed for line source atomic absorption, which provided a limited choice of analytical wavelengths, insufficient spectral resolution, and spectral interferences. However, the development of high-resolution continuum source atomic absorption spectrometry (HR-CS AAS) instrumentation has allowed the analysis of challenging samples for non-metals as well as some difficult elements to determine by AAS, such as aluminum and phosphorus. In this review, theory and analytical considerations for MAS are discussed. The principles and limitations of low resolution MAS are described, along with its applications. HR-CS AAS instrumentation is reviewed, emphasizing performance characteristics most relevant for MAS. Applications of flame and HR-CS GFMAS are reviewed, highlighting the most significant work to date. The paper concludes with an evaluation of the enhanced analytical capabilities provided by HR-CS MAS.
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  • 文章类型: Journal Article
    考虑到由磁性颗粒的固有特性产生的许多优点,在固相萃取中使用磁性材料近年来受到了相当大的关注。磁性固相萃取(MSPE)方法克服了诸如柱填充和相分离等问题,这可以通过施加外部磁场来容易地执行。在过去的几年中,自动系统中磁性粒子的使用正在增长,这使MSPE的在线操作成为绿色化学框架中一种有前途的技术。本文旨在提供与不同检测系统耦合的新型磁性材料作为金属预浓缩和测定吸附剂的研究进展,以及它们在顺序注射和微流体系统中的实施。此外,准备的描述,表征以及各种类型的磁性材料的应用,磁芯有有机或无机涂层,是presented。最后还评论了结束语和未来趋势。
    The use of magnetic materials in solid phase extraction has received considerable attention in recent years taking into account many advantages arising from the inherent characteristics of magnetic particles. Magnetic solid phase extraction (MSPE) methodology overcomes problems such as column packing and phase separation, which can be easily performed by applying an external magnetic field. The use of magnetic particles in automatic systems is growing over the last few years making the on-line operation of MSPE a promising technique in the frame of green chemistry. This article aims to provide all recent progress in the research of novel magnetic materials as sorbents for metal preconcentration and determination coupled with different detection systems as well as their implementation in sequential injection and microfluidic systems. In addition, a description of preparation, characterization as well as applications of various types of magnetic materials, either with organic or inorganic coating of the magnetic core, is presented. Concluding remarks and future trends are also commented.
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  • 文章类型: Journal Article
    背景:脉冲染料激光(PDL)在炎症性皮肤病治疗中的地位尚不清楚。缺乏基于证据的建议。
    目的:我们试图系统地回顾所有关于PDL治疗炎症性皮肤病的文献,并提出建议。
    方法:我们在PubMed数据库中搜索了1992年1月至2011年8月之间的出版物。获得了所有报告PDL治疗炎症性皮肤病的研究,并确定了证据水平。
    结果:文献检索显示有52篇文章可纳入本研究。用PDL治疗的炎症性皮肤病包括:牛皮癣,寻常痤疮,红斑狼疮,面部肉芽肿,结节病,湿疹性病变,丘疹脓疱酒渣鼻,扁平苔藓硬化,环状肉芽肿,Jessner淋巴细胞浸润皮肤,和网状红斑粘液病。描述并评估了PDL激光治疗这些炎症性皮肤病的疗效。
    结论:大多数结论并非基于随机对照试验。
    结论:PDL治疗可被推荐为局部斑块状银屑病和寻常痤疮的有效和安全的治疗方法(推荐B级)。对于所有其他描述的炎症性皮肤病,PDL似乎很有希望,尽管推荐水平没有超过C级
    BACKGROUND: The position of the pulsed dye laser (PDL) in the treatment of inflammatory skin diseases is still unclear. Evidence-based recommendations are lacking.
    OBJECTIVE: We sought to systematically review all available literature concerning PDL treatment for inflammatory skin diseases and to propose a recommendation.
    METHODS: We searched for publications dated between January 1992 and August 2011 in the database PubMed. All studies reporting on PDL treatment for an inflammatory skin disease were obtained and a level of evidence was determined.
    RESULTS: Literature search revealed 52 articles that could be included in this study. The inflammatory skin diseases treated with PDL consisted of: psoriasis, acne vulgaris, lupus erythematodes, granuloma faciale, sarcoidosis, eczematous lesions, papulopustular rosacea, lichen sclerosis, granuloma annulare, Jessner lymphocytic infiltration of the skin, and reticular erythematous mucinosis. The efficacy of PDL laser treatment for these inflammatory skin diseases was described and evaluated.
    CONCLUSIONS: Most conclusions formulated are not based on randomized controlled trials.
    CONCLUSIONS: PDL treatment can be recommended as an effective and safe treatment for localized plaque psoriasis and acne vulgaris (recommendation grade B). For all other described inflammatory skin diseases, PDL seems to be promising, although the level of recommendation did not exceed level C.
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