Local pH and oxygen concentration at the interface of Zn alloys in Tris-HCl or HEPES buffered Hanks’ balanced salt solution

2022 ◽  
pp. 110061
Author(s):  
Cheng Wang ◽  
Xiao Liu ◽  
Di Mei ◽  
Min Deng ◽  
Yufeng Zheng ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Salt Solution ◽  
Local Ph ◽  
Zn Alloys

scholarly journals Impact of Wound Closure on the Corrosion Rate of Biodegradable Mg-Ca-Zn Alloys in the Oral Environment

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4226
Author(s):  
Ali Modabber ◽  
Daniela Zander ◽  
Naemi Zumdick ◽  
Daniel Schick ◽  
Kristian Kniha ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Salt Solution ◽  
Wound Closure ◽  
Artificial Saliva ◽  
Maxillofacial Surgery ◽  
Test Group ◽  
Strong Increase ◽  
Corrosion Rates ◽  
Hank’S Solution ◽  
Zn Alloys

Magnesium alloys have exhibited a rapid rate of corrosion and thus early implant failure, so this study was designed to investigate the longer-term effects and in particular on wound closure. The aim of the study is to evaluate Mg-Ca-Zn Alloys as promising biodegradable implants in the field of maxillofacial surgery, which have so far never been evaluated for the changing conditions from a saliva to a serum-like environment after wound closure. Magnesium-0.6/calcium-0.8 wt.% zinc alloys were either immersed for 10 days in artificial saliva or 10 days in Hank’s salt solution as control groups. The test group was transferred from artificial saliva to Hank’s salt solution after 5 days in order to simulate wound closure. Corrosion rates were determined by immersion testing. Additional electron microscopy and energy dispersive X-ray spectroscopy (EDX) were performed. Prior artificial saliva exposure led to significantly decreased (p = 0.0272) corrosion rates after transfer to Hank’s solution in comparison to sole Hank’s solution exposure (0.1703 vs. 0.6675 mg/(cm2·day)) and sole artificial saliva exposure (0.3180 mg/(cm2·day)), which both exhibit a strong increase after 5 days. The results were in accordance with the scanning electron microscopy and EDX pictures. Prior saliva exposure could protect from increasing corrosion rates after wound closure. Thus Mg-Ca-Zn Alloys are promising future implant alloys in oral surgery, whereas other surgical fields without saliva exposure have to deal with accelerated corrosion rates after 5 days.

High-resolution transmission electron microscopic study of highly oxygen doped silicon layer

1989 ◽  
Vol 47 ◽  
pp. 692-693
Author(s):  
H. Takaoka ◽  
M. Tomita ◽  
T. Hayashi
Keyword(s):  
High Resolution ◽  
Oxygen Concentration ◽  
Silicon Layer ◽  
Detailed Structure ◽  
Electron Microscopic ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Doped Silicon ◽  
Argon Ion

High resolution transmission electron microscopy (HRTEM) is the effective technique for characterization of detailed structure of semiconductor materials. Oxygen is one of the important impurities in semiconductors. Detailed structure of highly oxygen doped silicon has not clearly investigated yet. This report describes detailed structure of highly oxygen doped silicon observed by HRTEM. Both samples prepared by Molecular beam epitaxy (MBE) and ion implantation were observed to investigate effects of oxygen concentration and doping methods to the crystal structure.The observed oxygen doped samples were prepared by MBE method in oxygen environment on (111) substrates. Oxygen concentration was about 1021 atoms/cm3. Another sample was silicon of (100) orientation implanted with oxygen ions at an energy of 180 keV. Oxygen concentration of this sample was about 1020 atoms/cm3 Cross-sectional specimens of (011) orientation were prepared by argon ion thinning and were observed by TEM at an accelerating voltage of 400 kV.

The Effects of Passive and Active Smoking on Brachial and radial Blood Pressure and Some Other Physical Factors in Healthy Young Adults

2017 ◽  
Vol 5 (3) ◽  
pp. 259
Author(s):  
Shireen H. Ramadhan ◽  
Shamil K. Talal ◽  
Wasfiya A. Moner
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Oxygen Saturation ◽  
Oxygen Concentration ◽  
Tobacco Smoke ◽  
Blood Pressure Measurement ◽  
Reference Level ◽  
Physical Factors ◽  
New Device ◽  
Active Smoker

Tobacco smoke is enormously harmful to human health, there’s no safe way to smoke. The primary objective of this study is to analyze the role of tobacco smoke compounds and their ability to damage the cardiovascular system and, in particular, to interfere with blood pressure (Brachial and radial pressure), heart rate and partly on the percentage blood Oxygen saturation. A new device has been manufactured which is unique for measuring the level of smoke, to obtained privies readings, the device had fixed to the first reference level آ and starting up from it. The effect of smoking has been studied on (26) male passive (26) active smoker volunteer, (14) female passive and (14) female active smoker participants. The results has been showed that the blood pressure and heart rate has been increased with increasing the number of cigarettes in both genders for passive and active smokers. However, this effect for male was more pronounced comparing with females for passive and active smokers. In the case of oxygen saturation concentration percentage, for males the change of oxygen concentration percentage was not stable. In other words, it was fluctuated with the number of cigarettes. But for females the oxygen concentration was decreased but not too much. This means that this effect was not pronounced. this study found آ that the most pronounced effect has been shown by male’s comparison to females for both passive and active smokers. As well as in nonsmoker’s males, the relation between heart rate and smoke level is inversely proportional. While in male and female smokers and female nonsmokers the relation is proportional. In all cases the relation between the smoke level and time of smoking is inversely proportional. Finally males& females are affected differently by tobacco use; the sensitivities to smoke for males are higher than in females for passive and active smokers in both brachial and radial blood pressure measurement.

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