A comparison between one non-invasive and three invasive procedures used in the preparation of plant material for X-Ray microanalysis

Author(s):  
Patrick Echlin

It is generally accepted that accurate quantitative elemental x-ray microanalysis of bio-organic material depends critically on the way the sample is treated before it is analysed. It is axiomatic that preparative procedures which change the local permeability of samples are going to be less useful than procedures which do not affect this critical property of cells and tissues, particularly if highly diffusible electolytes are the focus of any investigation. Thus we generally eschew ambient temperature methods in favour of low temperature techniques which either slow down or halt diffusion processes. As part of a larger study on the distribution and local concentration of aluminium in the developing leaves of tea plants, which under some circumstances can be as high 30,000ppm, a comparative study has been carried out to assess the effectiveness of four preparative techniques in retaining this element in the cell walls and vacuoles of older tea leaves which are know to contain more aluminium than younger leaves.

1978 ◽  
Vol 33 (5-6) ◽  
pp. 444-446 ◽  
Author(s):  
E. Steudle ◽  
A . Läuchli ◽  
A . Sievers

The identification of Ca2+ by X-ray microanalysis in statoliths could be masked by Ba2+. Using Ba2+ and Ca2+ containing standards prepared from algal cell walls and cellulose acetate films it is shown that there is no inter­ference of Ba2+ with Ca2+. Hence Ba2+ is the main cationic constituent in the statoliths of Chara rhizoids.


2019 ◽  
Vol 3 (2) ◽  
pp. 9 ◽  
Author(s):  
Yoichi Haruyama ◽  
Tsuguhisa Fujiwara ◽  
Keisuke Yasuda ◽  
Manabu Saito ◽  
Kohtaku Suzuki

We have determined the distribution of aluminum in the epidermal cells of mature tea leaves using micro-beam particle-induced X-ray emission. The observed pattern of aluminum distribution in the epidermal cells suggests that aluminum exists in cell walls. Silicon exhibits a distribution that is nearly identical to that of aluminum, suggesting co-localization with aluminum.


Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.


2020 ◽  
Vol 13 (4) ◽  
pp. 184-190
Author(s):  
Muhammad Irfan ◽  
Abdul Rasheed Qureshi ◽  
Zeeshan Ashraf ◽  
Muhammad Amjad Ramzan ◽  
Tehmina Naeem ◽  
...  

ABSTRACT Background: Conventionally Pleural effusions are suspected by history of pleuritis, evaluated by physical signs and multiple view radiography. Trans-thoracic pleural aspiration is done and aspirated pleural fluid is considered the gold-standard for pleural effusion. Chest sonography has the advantage of having high diagnostic efficacy over radiography for the detection of pleural effusion. Furthermore, ultrasonography is free from radiation hazards, inexpensive, readily available  and feasible for use in ICU, pregnant and pediatric patients. This study aims to explore the diagnostic accuracy of trans-thoracic ultrasonography for pleural fluid detection, which is free of such disadvantages. The objective is to determine the diagnostic efficacy of trans-thoracic ultrasound for detecting pleural effusion and also to assess its suitability for being a non-invasive gold-standard.   Subject and Methods: This retrospective study of 4597 cases was conducted at pulmonology  OPD-Gulab Devi Teaching Hospital, Lahore from November 2016 to July 2018. Adult patients with clinical features suggesting pleural effusions were included while those where no suspicion of pleural effusion, patients < 14 years and pregnant ladies were excluded. Patients were subjected to chest x-ray PA and Lateral views and chest ultrasonography was done by a senior qualified radiologist in OPD. Ultrasound-guided pleural aspiration was done in OPD & fluid was sent for analysis. At least 10ml aspirated fluid was considered as diagnostic for pleural effusion. Patient files containing history, physical examination, x-ray reports, ultrasound reports, pleural aspiration notes and informed consent were retrieved, reviewed and findings were recorded in the preformed proforma. Results were tabulated and conclusion was drawn by statistical analysis. Results: Out of 4597 cases, 4498 pleural effusion were manifested on CXR and only 2547(56.62%) pleural effusions were proved by ultrasound while 2050 (45.57%) cases were reported as no Pleural effusion. Chest sonography demonstrated sensitivity, specificity, PPV, NPV and diagnostic accuracy 100 % each. Conclusions: Trans-thoracic ultrasonography revealed an excellent efficacy that is why it can be considered as non-invasive gold standard for the detection of pleural effusion.


Heritage ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 1165-1181
Author(s):  
Flavia Fiorillo ◽  
Lucia Burgio ◽  
Christine Slottved Kimbriel ◽  
Paola Ricciardi

This study presents the results of the technical investigation carried out on several English portrait miniatures painted in the 16th and 17th century by Nicholas Hilliard and Isaac Oliver, two of the most famous limners working at the Tudor and Stuart courts. The 23 objects chosen for the analysis, spanning almost the entire career of the two artists, belong to the collections of the Victoria and Albert Museum (London) and the Fitzwilliam Museum (Cambridge). A non-invasive scientific methodology, comprising of stereo and optical microscopies, Raman microscopy, and X-ray fluorescence spectroscopy, was required for the investigation of these small-scale and fragile objects. The palettes and working techniques of the two artists were characterised, focusing in particular on the examination of flesh tones, mouths, and eyes. These findings were also compared to the information written in the treatises on miniature painting circulating during the artists’ lifetime. By identifying the materials and techniques most widely employed by the two artists, this study provides information about similarities and differences in their working methods, which can help to understand their artistic practice as well as contribute to matters of attribution.


CrystEngComm ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 2215-2221
Author(s):  
Emma Dennis ◽  
Soumya Kundu ◽  
Deepak Thrithamarassery Gangadharan ◽  
Jingjun Huang ◽  
Victor M. Burlakov ◽  
...  

Well-oriented PbBr2 microwires with a length-to-width ratio of up to 5000 were grown using a concentration gradient in co-crystallization with perovskite. Planar-integrated microwires showed a response to X-ray photons.


Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 1066 ◽  
Author(s):  
Gea Guerriero ◽  
Ian Stokes ◽  
Nathalie Valle ◽  
Jean-Francois Hausman ◽  
Christopher Exley

Silicon is a non-essential element for plants and is available in biota as silicic acid. Its presence has been associated with a general improvement of plant vigour and response to exogenous stresses. Plants accumulate silicon in their tissues as amorphous silica and cell walls are preferential sites. While several papers have been published on the mitigatory effects that silicon has on plants under stress, there has been less research on imaging silicon in plant tissues. Imaging offers important complementary results to molecular data, since it provides spatial information. Herein, the focus is on histochemistry coupled to optical microscopy, fluorescence and scanning electron microscopy of microwave acid extracted plant silica, techniques based on particle-induced X-ray emission, X-ray fluorescence spectrometry and mass spectrometry imaging (NanoSIMS). Sample preparation procedures will not be discussed in detail, as several reviews have already treated this subject extensively. We focus instead on the information that each technique provides by offering, for each imaging approach, examples from both silicifiers (giant horsetail and rice) and non-accumulators (Cannabis sativa L.).


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