scholarly journals "Mechanical and In Vitro Corrosion Properties of a Heat-Treated Mg-Zn-Ca-Mn Alloy as a Potential Bioresorbable Material"

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Ibrahim Hamdy ◽  
Moghaddam N Shayesteh ◽  
Elahinia Mohammad
Keyword(s):  
Corrosion Properties ◽  
Heat Treated ◽  
Bioresorbable Material

scholarly journals Effect of solid-solution and aging treatment on corrosion behavior of orthogonal designed and vacuum melted Mg-Zn-Ca-Mn alloys

2020 ◽  
Vol 18 ◽  
pp. 228080001988790 ◽  
Author(s):  
Dexue Liu ◽  
Tianshui Zhou ◽  
Zehua Liu ◽  
Bing Guo
Keyword(s):  
Solid Solution ◽  
Corrosion Resistance ◽  
Degradation Rate ◽  
Cast Alloy ◽  
Vacuum Induction Melting ◽  
Corrosion Properties ◽  
X Ray ◽  
Orthogonal Method ◽  
Heat Treated

Fast degradation rate and inhomogeneous corrosion are obstacles for magnesium alloy bio-corrosion properties. In this paper, a quaternary Mg-Zn-Ca-Mn alloy was designed by an orthogonal method and prepared by vacuum induction melting to investigate its bio-corrosion. Microstructure, corrosion morphology, and bio-corrosion properties of as-cast alloys 1 to 5 with good corrosion resistance were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction with immersion and electrochemical tests in simulated body fluid (SBF), respectively. Both the orthogonal method and in vitro degradation experiments demonstrated that alloy 3 exhibited the lowest degradation rate among the tested quaternary Mg-Zn-Ca-Mn alloys. Then, as-cast alloy 3 was treated by solid-solution and solid-solution aging. In vitro experimental results indicated that as-cast alloy 3 showed better corrosion resistance than heat-treated specimens and the average corrosion rate was approximately 0.15 mm/y. Heat-treated alloy 3 exhibited more uniform corrosion than as-cast alloy specimens. These results suggest that alloy 3 has the potential to become a biodegradable candidate material.

The Effect of Heat-Treatment on Mechanical, Microstructural, and Corrosion Characteristics of a Magnesium Alloy With Potential Application in Resorbable Bone Fixation Hardware

2016 ◽  
Author(s):  
Hamdy Ibrahim ◽  
Andrew D. Klarner ◽  
Behrang Poorganji ◽  
David Dean ◽  
Alan A. Luo ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cast Alloy ◽  
Immersion Test ◽  
Mg Alloys ◽  
Corrosion Properties ◽  
Corrosion Tests ◽  
Orthopedic Fixation Devices ◽  
Heat Treated ◽  
Mechanical And Corrosion Properties

Mg alloys are promising materials for bone implant applications mainly due to their low specific density, desirable stiffness and bioresorbability in the human body. Mg-Zn-Ca alloys are among the most promising materials for resorbable orthopedic fixation devices due to their superior biocompatibility. However, the mechanical and corrosion properties of the as-cast Mg-Zn-Ca alloys are insufficient. Heat treatment is a practical approach for strengthening Mg alloys especially after the fabrication of porous structures and 3D-printed components. We have investigated heat treatment of these devices and have studied the resulting microstructure of Mg-1.6Zn-0.5Ca (wt. %) alloys by hardness, compression, scanning electron microscopy (SEM), and electrochemical and immersion corrosion tests. Mg-1.6Zn-0.5Ca alloy was prepared with high purity Mg, Zn and Ca by casting. The cast ingots were solution-treated at 510 °C for 3 h then quenched in water. The quenched ingots were age hardened in an oil bath at 200 °C for 2 h. Pure Mg, as-cast and heat-treated Mg-1.6Zn-0.5Ca alloy ingots were cut into coupons to characterize their mechanical and corrosion properties. In vitro corrosion tests were conducted in modified simulated body fluid (m-SBF) at pH 7.4 and 37 °C. The hardness of the Mg-Zn-Ca alloy was significantly increased from 52.6 to be 66.8 HV after heat treatment. Also, the compression test results revealed that the heat-treated alloy has the highest compressive yield and ultimate strengths without significant change in stiffness and maximum strain. The mass loss of the Mg-Zn-Ca alloy by week 4 of the in vitro immersion test reduced from 174.6 mg/cm2 for the as-cast alloy to 101.7 mg/cm2 after the heat-treatment process. Heat-treatment was found to be a powerful post-shaping process not only to enhance the mechanical properties of the Mg-1.6Zn-0.5Ca (wt. %) alloy, but also to significantly improve its biocorrosion properties. Such heat-treated alloys can also be coated with biocompatible ceramics that provide additional protection from corrosion during the bone healing period (3–4 months).

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

1995 ◽  
Vol 74 (03) ◽  
pp. 868-873 ◽  
Author(s):  
Silvana Arrighi ◽  
Roberta Rossi ◽  
Maria Giuseppina Borri ◽  
Vladimir Lesnikov ◽  
Marina Lesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Animal Model ◽  
Factor Viii ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Virus Inactivation ◽  
Enveloped Viruses ◽  
Model Studies ◽  
Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

scholarly journals Radiofrequency Irradiation Modulates TRPV1-Related Burning Sensation in Rosacea

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1424
Author(s):  
Seyeon Oh ◽  
Myeongjoo Son ◽  
Joonhong Park ◽  
Donghwan Kang ◽  
Kyunghee Byun
Keyword(s):  
Burning Sensation ◽  
In Vivo Model ◽  
Molecular Evidence ◽  
Exposed Skin ◽  
Heat Treated ◽  
Vitro Model ◽  
Effective Use ◽  
Inflammatory Molecules

Rosacea is a skin inflammatory condition that is accompanied by not only redness and flushing but also unseen symptoms, such as burning, stinging, and itching. TRPV1 expression in UVB-exposed skin can lead to a painful burning sensation. Upregulated TRPV1 expression helps release neuropeptides, including calcitonin gene-related peptide, pituitary adenylate cyclase-activating polypeptide, and vasoactive intestinal peptide, which can activate macrophage and inflammatory molecules. In this study, we found that radiofrequency (RF) irradiation reduced TRPV1 activation and neuropeptide expression in a UVB-exposed in vivo model and UVB- or heat-treated in an in vitro model. RF irradiation attenuated neuropeptide-induced macrophage activation and inflammatory molecule expression. Interestingly, the burning sensation in the skin of UVB-exposed mice and patients with rosacea was significantly decreased by RF irradiation. These results can provide experimental and molecular evidence on the effective use of RF irradiation for the burning sensation in patients with rosacea.

In vitro dynamic gastric digestion of soya protein/milk protein blended beverages: influence of protein composition and co-processing

2021 ◽  
Vol 12 (6) ◽  
pp. 2605-2616
Author(s):  
Teresa Francis Wegrzyn ◽  
Alejandra Acevedo-Fani ◽  
Simon M. Loveday ◽  
Harjinder Singh
Keyword(s):  
Whey Protein ◽  
Milk Protein ◽  
Protein Composition ◽  
Soya Protein ◽  
Gastric Digestion ◽  
Heat Treated ◽  
Protein Milk

The gastric digestion behaviours of blended protein beverages containing different ratios of casein, whey protein and soya protein that were heat-treated at 60 °C or 80 °C were investigated using an in vitro dynamic human gastric simulator.

The influence of different geometries of matrix/scaffold on the remodeling process of a bone and bioresorbable material mixture with voids

2015 ◽  
Vol 22 (5) ◽  
pp. 969-987 ◽  
Author(s):  
Ivan Giorgio ◽  
Ugo Andreaus ◽  
Tomasz Lekszycki ◽  
Alessandro Della Corte
Keyword(s):  
Bone Growth ◽  
Matrix Material ◽  
Porous Solids ◽  
Artificial Material ◽  
Matrix Deposition ◽  
Aspect Ratios ◽  
Adopted Model ◽  
The Matrix ◽  
Bioresorbable Material

Since internal architecture greatly influences crucial factors for tissue regeneration, such as nutrient diffusion, cell adhesion and matrix deposition, scaffolds have to be carefully designed, keeping in mind case-specific mechanical, mass transport and biological requirements. However, customizing scaffold architecture to better suit conflicting requirements, such as biological and mechanical ones, remains a challenging issue. Recent advances in printing technologies, together with the synthesis of novel composite biomaterials, have enabled the fabrication of various scaffolds with defined shape and controlled in vitro behavior. Thus, the influence of different geometries of the assemblage of the matrix and scaffold on the remodeling processes of living bone and artificial material should be investigated. To this end, two implant shapes are considered in this paper, namely a circular inclusion and a rectangular groove of different aspect ratios. A model of a mixture of bone tissue and bioresorbable material with voids was used to numerically analyze the physiological balance between the processes of bone growth and resorption and artificial material resorption in a plate-like sample. The adopted model was derived from a theory for the behavior of porous solids in which the matrix material is elastic and the interstices are void of material.

scholarly journals Microhardness and In Vitro Corrosion of Heat-Treated Mg–Y–Ag Biodegradable Alloy

Materials ◽  
2017 ◽  
Vol 10 (1) ◽  
pp. 55 ◽  
Author(s):  
Marián Vlček ◽  
František Lukáč ◽  
Hana Kudrnová ◽  
Bohumil Smola ◽  
Ivana Stulíková ◽  
...  
Keyword(s):  
Heat Treated

In vitro and in vivo anti-corrosion properties and bio-compatibility of 5β-TCP/Mg-3Zn scaffold coated with dopamine-gelatin composite

2019 ◽  
Vol 374 ◽  
pp. 152-163 ◽  
Author(s):  
Xiaohua Zhou ◽  
Jianan OuYang ◽  
Li Li ◽  
Qing Liu ◽  
Congcong Liu ◽  
...  
Keyword(s):  
Corrosion Properties ◽  
Bio Compatibility

Nutritive evaluation of heat-treated cottonseed with in vitro gas production

2003 ◽  
Vol 2003 ◽  
pp. 175-175
Author(s):  
A. R. Foroughi ◽  
A. A. Naserian ◽  
R. Valizadeh ◽  
M. Danesh Mesgaran ◽  
A. Mirhady
Keyword(s):  
Nutritive Value ◽  
Gas Production ◽  
Value Evaluation ◽  
In Vitro Gas Production ◽  
Heat Treated ◽  
Gas Measurements ◽  
Biological Methods ◽  
Digestion Kinetics ◽  
Kinetics Of

Biological methods are more meaningful since microorganisms and enzymes are more sensitive to factors influencing the rate and extent of digestion than are chemical methods (Getachew and et al,1997).Gas measurements provides a useful data on digestion kinetics of both soluble and insoluble fractions of feedstuffs. The objective of this experiment was to determine nutritive value evaluation of heat-treated cottonseed with in vitro gas production.

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