کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1687741 | 1010682 | 2007 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
In-vacuum micro-PIXE analysis of biological specimens in frozen-hydrated state
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کلمات کلیدی
82.80.Yc89.60.−k82.80.−d - 82.80.-d87.23.−n - 87.23.-nMass loss - از دست دادن تودهMass gain - افزایش توده ایElemental distribution - توزیع عنصریMass spectrometry - طیف سنجی جرمیelemental concentration - غلظت عنصرNuclear microprobe - میکرو پروب هسته ایProton microprobe - میکرو پروب پروتونX-ray microanalysis - میکروسکوپ اشعه ایکسFrozen-hydrated specimens - نمونه های منجمد شده هیدراته
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سطوح، پوششها و فیلمها
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The first in-vacuum measurements of biological specimens in frozen-hydrated state using proton microbeam have been performed at Materials Research Group, iThemba LABS, South Africa. A commercially available cryotransfer system used in electron microscopy has been adapted for this purpose. The analyzed material was frozen in propane cooled by liquid nitrogen, fractured, carbon coated and transferred onto the cold stage (100Â K) in the nuclear microprobe chamber. Micro-PIXE and simultaneous proton backscattering was performed using 3Â MeV proton beam. Monitoring of water vapour composition during the proton bombardment showed good stability of the analyzed material. Quantitative results were obtained by standardless method, tested using 20% gelatine standards with added PbCl2. The differences between the concentrations obtained for frozen-hydrated and next freeze-dried specimens and the value calculated on the basis of weighted mass of PbCl2 added to gelatine were statistically insignificant. Leaf tissue of Senecio anomalochrous and larvae of Chysolina pardalina were used as examples of plant and animal tissue. Quantitative elemental mapping of frozen-hydrated specimens compared with subsequent analysis of the same areas after freeze-drying revealed the same distribution pattern in both cases.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 260, Issue 1, July 2007, Pages 141-148
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 260, Issue 1, July 2007, Pages 141-148
نویسندگان
G. Tylko, J. Mesjasz-PrzybyÅowicz, W.J. PrzybyÅowicz,