Boride Coating on Titanium Alloys as Biomaterial in Wear and Fretting Applications

The issue taken into account is the lifespan and potential toxicity of arthroprostheses with a focus on metal-polyethylene coupling. The gold standard for hip prostheses is a femoral component made of Ti6Al4V alloy, a head made of Co-Cr-Mo alloy and an insert made of UHMWPE while for knee prostheses the gold standard is a tibial component made of Co-Cr-Mo alloy, a femoral component made of Ti6Al4V and an insert made of UHMWPE. Open issues are wear of UHMWPE, toxicity of Co alloys and low fretting/wear resistance of Ti alloys. The aim of this research is to focus on the most biocompatible material (Ti6Al4V alloy) in order to improve its bio-tribological characteristics. A ceramic surface conversion by thermal treatment was used to obtain a borided coating on the titanium alloy surface in order to combine high hardness, good wettability and lubricant behavior of ceramics with good mechanical properties of Ti metal alloys. The coatings were characterized by means of optical microscope observation, FESEM analysis, XRD analysis, microindentation, scratch, friction and wear tests in order to identify the thermal treatment most suitable to obtain a coating with the required properties (thickness, hardness, roughness, wear resistance, friction coefficient and scratch resistance, surface lubrication ability in contact with human fluids) without significant modification of the microstructure of the substrate

Implementation of genomics in medical practice to deliver precision medicine for an Asian population

Whilst the underlying principles of precision medicine are comparable across the globe, genomic references, health practices, costs and discrimination policies differ in Asian settings compared to the reported initiatives involving European-derived populations. We have addressed these variables by developing an evolving reference base of genomic and phenotypic data and a framework to return medically significant variants to consenting research participants applicable for the Asian context. Targeting 10,000 participants, over 2000 Singaporeans, with no known pre-existing health conditions, have consented to an extensive clinical health screen, family health history collection, genome sequencing and ongoing follow-up. Genomic variants in a subset of genes associated with Mendelian disorders and drug responses are analysed using an in-house bioinformatics pipeline. A multidisciplinary team reviews the classification of variants and a research report is generated. Medically significant variants are returned to consenting participants through a bespoke return-of-result genomics clinic. Variant validation and subsequent clinical referral are advised as appropriate. The design and implementation of this flexible learning framework enables a cohort of detailed phenotyping and genotyping of healthy Singaporeans to be established and the frequency of disease-causing variants in this population to be determined. Our findings will contribute to international precision medicine initiatives, bridging gaps with ethnic-specific data and insights from this understudied population

Optimization of the design of ducted-fan hovering micro air vehicles using finite element simulation and orthogonal design

The structural design and flight stability characteristics of micro air vehicles have received much attention due to its low Reynolds number. Compared with fixed-wing aircraft, hovering ducted-fan micro air vehicles with vertical takeoff and landing and hovering capabilities have promising prospect. In this article, a flexible membrane and inflatable structure has been used as the aerodynamic shape of an aircraft model. Its advantages have been analyzed and verified by fluid-structure interaction based on finite element method. The flight stability of hovering micro air vehicles has also been investigated based on the theory of motion of structure. In order to improve the flight stability of the designed hovering micro air vehicle model, the effects of geometrical parameters and materials have been analyzed through an orthogonal experimental design. Based on the optimized results, the aircraft prototype has been manufactured for experimental test. The elastic deformation produced on its flexible membrane structure is obtained by stroboscopic stereo imaging method and a purpose-built experimental environment. The numerical simulation results indicated that the thickness of membrane and material of vertical duct have significant effects on the micro air vehicle flight stability and disturbance resistance ability. The results have confirmed that the flexible aerodynamic mechanisms produced by the aeroelastic deformation of spherical membrane can enhance the micro air vehicle stability.This work was financially supported by Support Program of National Ministry of Education of China (No. 625010110), National Natural Science Foundation of China (No. 61179043), and Specialized Research Fund for the Doctoral Program (SRFDP) of Higher Education (No. 20070056085)

First Steps towards Underdominant Genetic Transformation of Insect Populations

The idea of introducing genetic modifications into wild populations of insects to stop them from spreading diseases is more than 40 years old. Synthetic disease refractory genes have been successfully generated for mosquito vectors of dengue fever and human malaria. Equally important is the development of population transformation systems to drive and maintain disease refractory genes at high frequency in populations. We demonstrate an underdominant population transformation system in Drosophila melanogaster that has the property of being both spatially self-limiting and reversible to the original genetic state. Both population transformation and its reversal can be largely achieved within as few as 5 generations. The described genetic construct {Ud} is composed of two genes; (1) a UAS-RpL14.dsRNA targeting RNAi to a haploinsufficient gene RpL14 and (2) an RNAi insensitive RpL14 rescue. In this proof-of-principle system the UAS-RpL14.dsRNA knock-down gene is placed under the control of an Actin5c-GAL4 driver located on a different chromosome to the {Ud} insert. This configuration would not be effective in wild populations without incorporating the Actin5c-GAL4 driver as part of the {Ud} construct (or replacing the UAS promoter with an appropriate direct promoter). It is however anticipated that the approach that underlies this underdominant system could potentially be applied to a number of species. Figure

Sex differences in the association between plasma copeptin and incident type 2 diabetes: the Prevention of Renal and Vascular Endstage Disease (PREVEND) study

AIMS/HYPOTHESIS: Vasopressin plays a role in osmoregulation, glucose homeostasis and inflammation. Therefore, plasma copeptin, the stable C-terminal portion of the precursor of vasopressin, has strong potential as a biomarker for the cardiometabolic syndrome and diabetes. Previous results were contradictory, which may be explained by differences between men and women in responsiveness of the vasopressin system. The aim of this study was to evaluate the usefulness of copeptin for prediction of future type 2 diabetes in men and women separately. METHODS: From the Prevention of Renal and Vascular Endstage Disease (PREVEND) study, 4,063 women and 3,909 men without diabetes at baseline were included. A total of 208 women and 288 men developed diabetes during a median follow-up of 7.7 years. RESULTS: In multivariable-adjusted models, we observed a stronger association of copeptin with risk of future diabetes in women (OR 1.49 [95% CI 1.24, 1.79]) than in men (OR 1.01 [95% CI 0.85, 1.19]) (p (interaction) < 0.01). The addition of copeptin to the Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) clinical model improved the discriminative value (C-statistic,+0.007, p = 0.02) and reclassification (integrated discrimination improvement [IDI] = 0.004, p < 0.01) in women. However, we observed no improvement in men. The additive value of copeptin in women was maintained when other independent predictors, such as glucose, high sensitivity C-reactive protein (hs-CRP) and 24 h urinary albumin excretion (UAE), were included in the model. CONCLUSIONS/INTERPRETATION: The association of plasma copeptin with the risk of developing diabetes was stronger in women than in men. Plasma copeptin alone, and along with existing biomarkers (glucose, hs-CRP and UAE), significantly improved the risk prediction for diabetes in women

Smart homes and their users:a systematic analysis and key challenges

Published research on smart homes and their users is growing exponentially, yet a clear understanding of who these users are and how they might use smart home technologies is missing from a field being overwhelmingly pushed by technology developers. Through a systematic analysis of peer-reviewed literature on smart homes and their users, this paper takes stock of the dominant research themes and the linkages and disconnects between them. Key findings within each of nine themes are analysed, grouped into three: (1) views of the smart home-functional, instrumental, socio-technical; (2) users and the use of the smart home-prospective users, interactions and decisions, using technologies in the home; and (3) challenges for realising the smart home-hardware and software, design, domestication. These themes are integrated into an organising framework for future research that identifies the presence or absence of cross-cutting relationships between different understandings of smart homes and their users. The usefulness of the organising framework is illustrated in relation to two major concerns-privacy and control-that have been narrowly interpreted to date, precluding deeper insights and potential solutions. Future research on smart homes and their users can benefit by exploring and developing cross-cutting relationships between the research themes identified