SURFACE MODIFICATION ON THE STEM OF A TOTAL HIP JOINT REPLACEMENT
INTRODUCTION
Titanium and its alloys are used in various applications due to their desirable properties. One of the main sectors where titanium is highly used is in biomedical applications where both implants and tools for surgery make use of this element due to its biocompatibility, low modulus and excellent corrosion resistance. However titanium shows poor tribological properties and therefore it is generally alloyed and undergoes a surface modification to obtain the optimum requirements needed. Biomedical implants are subjected to high clinical requirements, hence before implantation in the human body, a surface modification process is carried out. The aim of carrying such modifications include; to sterilize the implant surface form contaminants before implantation, to increase the bioactivity, increase hardness and hence promotes the reduction in the implant wear rate and the introduction of a passive layer to minimize the ion release in the body.1
For this scope of this assignment a study in the surface modification of a titanium alloy stem, used in a hip joint implant is going to be studied. A total hip joint implant consists of an articulating bearing basically the femoral head and cup and the stem. The stem is made from titanium alloy - Ti- 6Al- 4V where titanium is alloyed with aluminium and vanadium. When titanium is alloyed with these materials excellent properties are achieved such as high strength-to-weight ratio and exceptional corrosion resistance.2 However, this alloy gives poor tribological properties and tends to seize when it is subjected to sliding motion due to its low hardness of 36HRC.3 Several surface modification techniques are done on ti...
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... The advanced technology of surface modification in the biomedical sector have the ability to offer not an improvement in the tribological properties only but also to improve the clinical requirements prior and post implantation. Such properties includes cell growth and antibacterial effect.
1-(pg4 doc.pdf)
2-http://www.arcam.com/wp-content/uploads/Arcam-Ti6Al4V-Titanium-Alloy.pdf
3- (reference ta lpdf twil)
4- http://www.news-medical.net/whitepaper/20130903/Hydroxyapatite-Coating-for-Titanium-Implants.aspx
Table 1 ghandek min http://www.azom.com/properties.aspx?ArticleID=1547 u l-pdf hi twil
5- http://emedicine.medscape.com/article/2085501-overview
6-http://www.intechopen.com/books/titanium-alloys-towards-achieving-enhanced-properties-for-diversified-applications/surface-modification-techniques-for-biomedical-grade-of-titanium-alloys-oxidation-carburization-and-
At the moment, the main objective for scientists and engineers is to develop surgery into a minimal invasive method and nanote...
Brauna has an extraordinary reputation. We are known for our use of metal plates, screws and other implantable devices. Unlike our most of our competitors, our artificial implants have not been recalled. We have special expertise and we develop and produce safer orthopedic products for surgeons worldwide. Teamwork enables Brauna to sustain its global operations in 14 countries and sales in 200 countries with 27,000 employees.
Out of the plays that we could have chosen to produce, I have decided to go with Molière’s, “Tartuffe.” This play is a comedy that comes from 17th century France and is heavily influenced by two large sources of experience for Molière. Those sources are the rules and structure for a play put in place by the French academy and the lessons of improvisation taught by the Commedia dell’Arte. This piece is written in fives acts that are in a unique alexandrine style of verse which have 12 syllables in a line and usually ends with rhyming words. The reason I chose this play is because, in my opinion, things like television, movies, plays, and other forms of media and entertainment are meant to transport you away from all the bad things happening in real life and focus you on something fun and/or interesting. I find this play to have a lot of fun moments that can be mined for even more comedy and I think it has the good chance to keep a large audience entertained for a long period of time. To accomplish my goal I will use elements of situational comedies, France in the 1660’s, and one of Molière’s plays, “A school for girls.”
Despite these advantages there are concerns which affect patient’s and surgeon’s decision to undertake metal-on-metal hip resurfacing arthroplasty. These issues range from being technically demanding, stringent patient selection criteria (11), high early incidence of femoral neck fractures(12, 13) and reported risk of high circulating metal ions(14-17). There are theoretical concerns about cancers following exposure to high levels of cobalt and chromium ions (18).
Throughout the Salem Witch Trials, a man named Samuel Parris had purchased a slave named Tituba who would then be accused of being a witch(Rebecca Brooks, 2013).. The Salem Witch Trials involved many people put to blame for being witches is they acted different, or acted out of the norm within their society. The witch hunts all began in the year of 1692 within the area of Salem. During the year of 1692, many people were being accused of being a witch and being thrown into jail. There were some conformations that Tituba was a witch as well from the people who lived around her.
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Titanium is prone to implant centred infections as a result of a biofilm being generated on its surface and its immune response being compromised at the implant/tissue interface. As previously mentioned, titanium is biocompatible and this is a result of the surface protein layer that is created under physiological conditions. However, the protein layer also creates an appropriate environment for bacteria to survive, colonise the implant and create a biofilm8. Bacteria commonly found on the surface of titanium include Staphylococcus aureus, Streptococcus mutans, Streptococcus sanguinis and Lactobacillus casei, all of which are facultative anaerobes9. As a result, the hosts defence system is impaired and this may result in an
1. (45 pts) For each major (CS, IT, DET, IS), identify three important and uniquely identifying characteristics and describe how the four types of professionals would work together in a professional setting. Include information learned from the various instructors for each discipline. How do professionals from these areas work together?
When I found out I qualified to be a candidate for the NJHS, I knew I had to take this chance. This group is made up of people who depict leadership, character, citizenship, academic success, and service and I would love to join. These characteristics wouldn't just be valuable for a candidate to have, but for everyone to have to exceed in life. If I were to be in the National Junior Honor Society, it would give me an opportunity to ameliorate my future and motivate me to do better.
In “The Fish” by Elizabeth Bishop, the narrator attempts to understand the relationship between humans and nature and finds herself concluding that they are intertwined due to humans’ underlying need to take away from nature, whether through the act of poetic imagination or through the exploitation and contamination of nature. Bishop’s view of nature changes from one where it is an unknown, mysterious, and fearful presence that is antagonistic, to one that characterizes nature as being resilient when faced against harm and often victimized by people. Mary Oliver’s poem also titled “The Fish” offers a response to Bishop’s idea that people are harming nature, by providing another reason as to why people are harming nature, which is due to how people are unable to view nature as something that exists and goes beyond the purpose of serving human needs and offers a different interpretation of the relationship between man and nature. Oliver believes that nature serves as subsidence for humans, both physically and spiritually. Unlike Bishop who finds peace through understanding her role in nature’s plight and acceptance at the merging between the natural and human worlds, Oliver finds that through the literal act of consuming nature can she obtain a form of empowerment that allows her to become one with nature.
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It is in gaining a sense of our identity that we find a place to belong. This is presented in Episode 4, Stand Up, of the television series Redfern Now, directed by Rachael Perkins.
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A transculturation is used to describe the phenomenon of merging and converging cultures. Transculturation is a term to describe the process from transitioning from one culture to another culture. The Cuban anthropologist Fernando Ortiz describe transculturation in five phases, enslavement, compromise, adjustment, self-assertion and integration. Transculturation is very common today. Anthropologist still use the term transculturation because overtime culture has changed a lot for an example, back then the cultures were much more isolated due to less population and more available land, also, they were less technology and transportation. My family and I experienced transculturation due to the contrasting culture differences between America and
Various factors have been attributed for the success of the implant and impression material and the technique is one of which is considered very crucial and important criteria in the success of fabrication and long lasting of the restoration. A dental impression is a negative imprint of an oral structure used to produce a positive replica of the structure for use as a permanent record or in the production of a dental restoration or prosthesis. Since the accuracy of the impression affects the accuracy of the definitive cast, an accurate impression is essential to fabricate prosthesis with good fit. An inaccurate impression may result in prosthesis misfit, which may lead to mechanical and/or biological complications.