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Nasution A.K.,University of Technology Malaysia | Nasution A.K.,Muhammadiyah University of Riau | Murni N.S.,University of Technology Malaysia | Sing N.B.,University of Technology Malaysia | And 2 more authors.
Journal of Biomedical Materials Research - Part B Applied Biomaterials

This article describes the development of a partially degradable metal bone pin, proposed to minimize the occurrence of bone refracture by avoiding the creation of holes in the bone after pin removal procedure. The pin was made by friction welding and composed of two parts: the degradable part that remains in the bone and the nondegradable part that will be removed as usual. Rods of stainless steel 316L (nondegradable) and pure iron (degradable) were friction welded at the optimum parameters: forging pressure 533.2 kPa, friction time525 s, burn-off length515 mm, and heat input54.58 J/s. The optimum tensile strength and elongation was registered at 666 MPa and 13%, respectively. A spiral defect formation was identified as the cause for the ductile fracture of the weld joint. A 40-μm wide intermetallic zone was identified along the fusion line having a distinct composition of Cr, Ni, and Mo. The corrosion rate of the pin gradually decreased from the undeformed zone of pure iron to the undeformed zone of stainless steel 316L. All metallurgical zones of the pin showed no toxic effect toward normal human osteoblast cells, confirming the ppb level of released Cr and Ni detected in the cell media were tolerable. © 2014 WILEY PERIODICALS, INC. Source

Ulum M.F.,University of Technology Malaysia | Ulum M.F.,Bogor Agricultural University | Arafat A.,University of Technology Malaysia | Noviana D.,Bogor Agricultural University | And 5 more authors.
Materials Science and Engineering C

Biodegradable metals such as magnesium, iron and their alloys have been known as potential materials for temporary medical implants. However, most of the studies on biodegradable metals have been focusing on optimizing their mechanical properties and degradation behavior with no emphasis on improving their bioactivity behavior. We therefore investigated the possibility of improving iron biodegradation rate and bioactivity by incorporating various bioactive bioceramics. The iron-based bioceramic (hydroxyapatite, tricalcium phosphate and biphasic calcium phosphate) composites were prepared by mechanical mixing and sintering process. Degradation studies indicated that the addition of bioceramics lowered the corrosion potential of the composites and slightly increased their corrosion rate compared to that of pure iron. In vitro cytotoxicity results showed an increase of cellular activity when rat smooth muscle cells interacted with the degrading composites compared to pure iron. X-ray radiogram analysis showed a consistent degradation progress with that found in vivo and positive tissue response up to 70 days implantation in sheep animal model. Therefore, the iron-based bioceramic composites have the potential to be used for biodegradable bone implant applications. © 2013 Elsevier B.V. Source

Sarwinda D.,Muhammadiyah University of Riau | Daqiqil Id I.,University of Riau
Proceedings of 2015 International Conference on Information and Communication Technology and Systems, ICTS 2015

This paper applied volumetric analysis and voxel based morphometry (VBM) from 3D magnetic resonance images of brain to detect Alzheimer's disease. Image preprocessing is selected as a method to identify changes in brain volume between Alzheimer and normal control with segmentation process for some tissues in brain such as gray matter, white matter and cerebrospinal fluid. Moreover, statistical testing with two-sample t-test has done to see significant difference between the average volume of Alzheimer's and normal brain. The testing results showed a significant difference between the average volume of Alzheimer's and normal brain. Gender difference is one of the causes of changes in brain volume. Women suffered from Alzheimer have a number of less brain volumes than men. © 2015 IEEE. Source

Muhammadiyah University of Riau | Entity website

Seluruh mahasiswa Universitas Muhammadiyah Riau (UMRI) yang memenuhi ketentuan mempunyai peluang untuk mendapatkan beasiswa dari : Beasiswa BIDIK MISI dari DIKTI, Beasiswa dari Pemerintah Provinsi Riau, Dll

Muhammadiyah University of Riau | Entity website

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