Visualization of Plant Root Morphology in situ Based on X-ray CT Imaging Technology

Author(s):  
Xiwen Luo ◽  
Xuecheng Zhou ◽  
Xiaolong Yan
2021 ◽  
Vol 11 (1) ◽  
pp. 114-119
Author(s):  
Ying Wu ◽  
Guohua Huang ◽  
Qiufeng Li ◽  
Jinai He

Objective: The objective is to explore the application of computed X-ray tomography (CT) imaging technology in peripherally inserted central catheter (PICC), and to propose a more effective method for PICC catheterization. Method: In this study, 69 subjects are divided into the observation group (X-ray and CT) and the control group (X-ray). The guiding effect of CT images on PICC tube placement in complex cases is compared. In this study, CT localization of the superior vena cava–caval-atrial junction (CAJ) is used as the gold standard. The position relationship of carina-CAJ and carina-PICC catheter tip is measured and analyzed by CT image and chest radiography (CXR) image, providing scientific basis for PICC tip imaging. Results: After this study, the tip of the catheter should be 1/3 of the middle and lower part of the superior vena cava, about 3 cm above the junction of the right atrium and the superior vena cava, and in the upper part of the diaphragm of the inferior vena cava, so that it cannot enter the right ventricle or the right atrium. The best position of the tip of the catheter is near the junction of the superior vena cava and the right atrium. The average vertical distance between the tracheal carina and CAJ is 4.79 cm. Conclusion: CT and X-ray examination can effectively determine the location of the tip of PICC catheter in cancer chemotherapy patients, but the clarity of X-ray examination is missing. It is suggested to adopt CT examination, and further adopt and promote it.


2019 ◽  
Vol 26 (4) ◽  
pp. 1272-1279 ◽  
Author(s):  
Peng Wang ◽  
Brigid A. McKenna ◽  
Neal W. Menzies ◽  
Cui Li ◽  
Chris J. Glover ◽  
...  

Iron (Fe) plays an important role within environmental systems. Synchrotron-based X-ray approaches, including X-ray absorption spectroscopy (XAS), provide powerful tools for in situ analyses of Fe speciation, but beam damage during analysis may alter Fe speciation during its measurement. XAS was used to examine whether experimental conditions affect the analysis of Fe speciation in plant tissues. Even when analyzed in a cryostat at 12 K, it was found that FeIII can rapidly (within 0.5–1 min) photoreduce to FeII, although the magnitude of photoreduction varied depending upon the hydration of the sample, the coordination chemistry of the Fe, as well as other properties. For example, photoreduction of FeIII was considerably higher for aqueous standard compounds than for hydrated plant-root tissues. The use of freeze-dried samples in the cryostat (12 K) markedly reduced the magnitude of this FeIII photoreduction, and there was no evidence that the freeze-drying process itself resulted in experimental artefacts under the current experimental conditions, such as through the oxidation of FeII, although some comparatively small differences were observed when comparing spectra of hydrated and freeze-dried FeII compounds. The results of this study have demonstrated that FeIII photoreduction can occur during X-ray analysis, and provides suitable conditions to preserve Fe speciation to minimize the extent of beam damage when analyzing environmental samples. All studies utilizing XAS are encouraged to include a preliminary experiment to determine if beam damage is occurring, and, where appropriate, to take the necessary steps (such as freeze drying) to overcome these issues.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


1997 ◽  
Vol 7 (C2) ◽  
pp. C2-619-C2-620 ◽  
Author(s):  
M. Giorgett ◽  
I. Ascone ◽  
M. Berrettoni ◽  
S. Zamponi ◽  
R. Marassi

2019 ◽  
Author(s):  
Christian Prehal ◽  
Aleksej Samojlov ◽  
Manfred Nachtnebel ◽  
Manfred Kriechbaum ◽  
Heinz Amenitsch ◽  
...  

<b>Here we use in situ small and wide angle X-ray scattering to elucidate unexpected mechanistic insights of the O2 reduction mechanism in Li-O2 batteries.<br></b>


Sign in / Sign up

Export Citation Format

Share Document