The Application of Zeeko Polishing Technology to Freeform Femoral Knee Replacement Component Manufacture

The purpose of this study was to develop an advanced 7-axis Computer Numerical Controlled (CNC) Polishing Machine from its successful original application of industrial optics manufacture into a process for the manufacture of femoral knee components to improve wear characteristics and prolong component lifetimes. It was indentified that the successful manufacture of optical components using a corrective polishing procedure to enhance their performance could be applied to femoral knee implant components. Current femoral knee implants mimic the natural shape of the joint and are freeform (no axis of symmetry) in nature hence an advanced CNC polishing machine that can follow the contours associated with such shapes could improve surface finish and conformity of replacement femoral knee bearing surfaces, leading to improved performance. The process involved generating machine parameters that would optimize the polishing procedure to minimize wear of materials used in femoral knee implant manufacture. Secondly a design of a Non-Uniform Refind B-Spline (NURBS) model for control of the Polishing Machine over the freeform contours of the femoral component. Completing the process involved development of a corrective polishing process that would improve form control of the components. Such developments would improve surface finish and conformity which are well documented contributors to wear and hence the lifeline of orthopaedic implants. By the means of comparison of this technique to that of a conventional finishing technique using pin-on-plate disc testing it was concluded that performance of the CNC polished components was an improvement on that of the conventional technique. In the case of form control their were slight indications through small decreases in peak to valley (PV) error that the process helped reduce form error and could increase the lifetime of femoral knee replacement components. The overall study provided results that indicate the the Zeeko process could be used in the application of polishing of hard-on-hard material combinations to improve form control without compromising surface finish hence improving lifetimes of the implant. The results have their limitations in the fact that the wear test performance was only carried out on orthopaedic implant materials using a pin-on-plate wear test rig. Due to the time limitations on the thesis it can be said that further analysis of correcting form without compromising surface finish on entire implant systems under full joint simulator testing which would provide mre realistic contitions would a more definitive answer be achieved

The application of Zeeko polishing technology to freeform femoral knee replacement component manufacture

The purpose of this study was to develop an advanced 7-axis Computer Numerical Controlled (CNC) Polishing Machine from its successful original application of industrial optics manufacture into a process for the manufacture of femoral knee components to improve wear characteristics and prolong component lifetimes. It was indentified that the successful manufacture of optical components using a corrective polishing procedure to enhance their performance could be applied to femoral knee implant components. Current femoral knee implants mimic the natural shape of the joint and are freeform (no axis of symmetry) in nature hence an advanced CNC polishing machine that can follow the contours associated with such shapes could improve surface finish and conformity of replacement femoral knee bearing surfaces, leading to improved performance. The process involved generating machine parameters that would optimize the polishing procedure to minimize wear of materials used in femoral knee implant manufacture. Secondly a design of a Non-Uniform Refind B-Spline (NURBS) model for control of the Polishing Machine over the freeform contours of the femoral component. Completing the process involved development of a corrective polishing process that would improve form control of the components. Such developments would improve surface finish and conformity which are well documented contributors to wear and hence the lifeline of orthopaedic implants. By the means of comparison of this technique to that of a conventional finishing technique using pin-on-plate disc testing it was concluded that performance of the CNC polished components was an improvement on that of the conventional technique. In the case of form control their were slight indications through small decreases in peak to valley (PV) error that the process helped reduce form error and could increase the lifetime of femoral knee replacement components. The overall study provided results that indicate the the Zeeko process could be used in the application of polishing of hard-on-hard material combinations to improve form control without compromising surface finish hence improving lifetimes of the implant. The results have their limitations in the fact that the wear test performance was only carried out on orthopaedic implant materials using a pin-on-plate wear test rig. Due to the time limitations on the thesis it can be said that further analysis of correcting form without compromising surface finish on entire implant systems under full joint simulator testing which would provide mre realistic contitions would a more definitive answer be achieved.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Surface integrity of fluid jet polished tungsten carbide

In recent years, Fluid Jet Polishing (FJP) has been studied for its potential as a finishing method on optical lenses, mirrors and molds for a number of materials, such a glass and nickel. In this paper, the surface integrity of binderless tungsten carbide after polishing by FJP was studied experimentally. Two aspects in particular were focused on: (1) identifying process conditions under which grain boundaries may dislocate (thus leading to unintentional loss of grains from the substrate) and (2) identify process conditions under which abrasive particles may become embedded into the substrate, in order to prevent surface contamination

Dynamically modulated core-shell microfibers to study the effect of depth sensing of matrix stiffness on stem cell fate

It is well known that extracellular matrix stiffness can affect cell fate and change dynamically during many biological processes. Existing experimental means for in situ matrix stiffness modulation often alters its structure, which could induce additional undesirable effects on cells. Inspired by the phenomenon of depth sensing by cells, we introduce here core–shell microfibers with a thin collagen core for cell growth and an alginate shell that can be dynamically stiffened to deliver mechanical stimuli. This allows for the maintenance of biochemical properties and structure of the surrounding microenvironment, while dynamically modulating the effective modulus “felt” by cells. We show that simple addition of Sr2+ in media can easily increase the stiffness of initially Ca2+ cross-linked alginate shells. Thus, despite the low stiffness of collagen cores (<5 kPa), the effective modulus of the matrix “felt” by cells are substantially higher, which promotes osteogenesis differentiation of human mesenchymal stem cells. We show this effect is more prominent in the stiffening microfiber compared to a static microfiber control. This approach provides a versatile platform to independently and dynamically modulate cellular microenvironments with desirable biochemical, physical, and mechanical stimuli without an unintended interplay of effects, facilitating investigations of a wide range of dynamic cellular processes

Síntese e avaliação catalítica de catalisadores microporoso, mesoporosos e micro-mesoporosos

As propriedades e potencialidades dos materiais porosos estão em constantes estudos e usos nas mais variadas áreas da ciência. Esses materiais são atribuídos em classes de acordo com o ordenamento dos seus blocos estruturantes. Suas propriedades estão intrinsecamente relacionadas pela sua capacidade de catalisar as reações químicas. Neste trabalho, catalisadores do tipo HAlZSM-12, HAlMCM-41, HAlMCM-48, AlSBA-15 (Si/Al= 25, 50, 75) e HAlZSM-12/HAlMCM-41, HAlZSM-12/HAlMCM-48, HAlZSM-12/AlSBA-15 foram sintetizados pelo método hidrotérmico, submetidas a processos de calcinação e troca iônica e caracterizados por difratometria de raios-X. No presente trabalho também avaliou-se o potencial catalítico dos catalisadores na pirólise catalítica do ácido oléico em escala de bancada usando a termogravimetria. _________________________________________________________________________________________ ABSTRACT: The properties and potential of porous materials are in constant studies and uses in various areas of science. These materials are attributed to classes according to their structural ordering of blocks. Their properties are intrinsically related by their ability to catalyze chemical reactions. In this study, catalysts of type HAlZSM-12, HAlMCM-41, HAlMCM-48, AlSBA-15 (Si/Al 25, 50, 75) and composites HAlZSM-12/HAlMCM-41, HAlZSM-12/HAlMCM-48, HAlZSM-12/AlSBA-15 were synthesized by hydrothermal method, subjected to calcination and ion exchange processes and characterized by X-ray diffraction. In this study also were evaluated the catalytic potential of catalysts in the catalytic pyrolysis of oleic acid in micro-scale tests using thermogravimetric (TG)

Innovation in Diabetes - Ideas and Initiatives

A collection of multiple reports on MyDiabetesMyWay (MDMW). Included reports are: MyDiabetesMyWay Patient Portal; MyDiabetesMyWay e-learning hub (Moodle) ; SCI-diabetes/ MDMW Communication Portal- Tools for Remote Communication/ Consultation; Risk Modelling for Care Planning- integration into Informatics Dashboard for Clinical Use; Access to Chronic Medication Service (CMS) and Pharmaceutical Care Planning Medication and Lifestyle Coaching; Multi-media Diabetes Resources; Promoting Diabetes Education; Tele-Pharmacy; Understanding my diabetes medication; Pharmaceutical Industry and Medical Technology (PIMTs); An on-line and interactive education system for young people with type 1 diabetes to understand self-management for their lifestyle; Proof of Concept study to deliver personalised use of information to support diabetes management and behaviour change; right information; right time; right way; Virtual promotion of physical activity for people with type 2 diabetes; Remote foot ulcer management: RAPID (Reducing Amputation in People with Diabetes); Diabetic foot screening – development of technology; Portable capillary HbA1c testing for diagnosis and self-monitoring of diabetes; Possibility of mobile phone adaption for testing; Web app for decision support for patients with type 1 diabetes undertaking sport or exercise; Online level 3 structured education for type 1 diabetes; My Diabetes My Way electronic personal health record – uptake at scale; TeleClinics for diabetes; Develop a diabetes sim / game in which the main character has diabetes. Young people need to keep the sim / character alive as they face the various challenges of life or the game; Development of meaningful automated glucose data to in-patient clinical areas; In-patient Care: Integrated eHealth solutions to improve patient care, safety and outcomes; Innovative model of care to address the 'process of care' in managing people with long term conditions; Young Persons Remote Clinic Consultation; Maximise use of the data to support self-management of patients with co-morbidities; Virtual practice outreach and education in primary care

Ledipasvir and Sofosbuvir Plus Ribavirin for Treatment of HCV Infection in Patients With Advanced Liver Disease

BACKGROUND & AIMS: There are no effective and safe treatments for chronic hepatitis C virus (HCV) infection of patients who have advanced liver disease. METHODS: In this phase 2, open-label study, we assessed treatment with the NS5A inhibitor ledipasvir, the nucleotide polymerase inhibitor sofosbuvir, and ribavirin in patients infected with HCV genotypes 1 or 4. Cohort A enrolled patients with cirrhosis and moderate or severe hepatic impairment who had not undergone liver transplantation. Cohort B enrolled patients who had undergone liver transplantation: those without cirrhosis; those with cirrhosis and mild, moderate, or severe hepatic impairment; and those with fibrosing cholestatic hepatitis. Patients were assigned randomly (1:1) to receive 12 or 24 weeks of a fixed-dose combination tablet containing ledipasvir and sofosbuvir, once daily, plus ribavirin. The primary end point was sustained virologic response at 12 weeks after the end of treatment (SVR12). RESULTS: We enrolled 337 patients, 332 (99%) with HCV genotype 1 infection and 5 (1%) with HCV genotype 4 infection. In cohort A (nontransplant), SVR12 was achieved by 86%-89% of patients. In cohort B (transplant recipients), SVR12 was achieved by 96%-98% of patients without cirrhosis or with compensated cirrhosis, by 85%-88% of patients with moderate hepatic impairment, by 60%-75% of patients with severe hepatic impairment, and by all 6 patients with fibrosing cholestatic hepatitis. Response rates in the 12- and 24-week groups were similar. Thirteen patients (4%) discontinued the ledipasvir and sofosbuvir combination prematurely because of adverse events; 10 patients died, mainly from complications related to hepatic decompensation. CONCLUSION: The combination of ledipasvir, sofosbuvir, and ribavirin for 12 weeks produced high rates of SVR12 in patients with advanced liver disease, including those with decompensated cirrhosis before and after liver transplantation. ClinTrials.gov: NCT01938430

HLA-DQA1*05 carriage associated with development of anti-drug antibodies to infliximab and adalimumab in patients with Crohn's Disease

Anti-tumor necrosis factor (anti-TNF) therapies are the most widely used biologic drugs for treating immune-mediated diseases, but repeated administration can induce the formation of anti-drug antibodies. The ability to identify patients at increased risk for development of anti-drug antibodies would facilitate selection of therapy and use of preventative strategies.This article is freely available via Open Access. Click on Publisher URL to access the full-text

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements