573 research outputs found
Investigation of the free flow electrophoretic process
The effects of gravity on the free flow electrophoretic process was demonstrated. The free flow electrophoresis chamber used to demonstrate the effects of gravity on the process was of a proprietary design. This chamber was 120 cm long, 16 cm wide, and 0.15 cm thick. Flow in this chamber was in the upward direction and exited through 197 outlets at the top of the chamber. During electrophoresis a stream of sample was injected into the flow near the bottom of the chamber and an electrical field was applied across the width of the chamber. The field caused a lateral force on particles in the sample proportional to the inherent change of the particle and the electric field strength. Particle lateral velocity was then dependent on the force due to viscous drag which was proportional to particle size and particle shape dependent
Investigation of the free flow electrophoretic process. Volume 1: Executive summary
The effect of gravity on the free flow electrophoretic process was investigated. The demonstrated effects were then compared with predictions made by mathematical models. Results show that the carrier buffer flow was affected by gravity induced thermal convection and that the movement of the separating particle streams was affected by gravity induced buoyant forces. It was determined that if gravity induced buoyant forces were included in the mathematical models, then effective predictions of electrophoresis chamber separation performance were possible
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Maternal obesity during pregnancy and lactation influences offspring obesogenic adipogenesis but not developmental adipogenesis in mice
Obesity is an escalating health crisis of pandemic proportions and by all accounts it has yet to reach its peak. Growing evidence suggests that obesity may have its origins in utero. Recent studies have shown that maternal obesity during pregnancy may promote adipogenesis in offspring. However, these studies were largely based on cell culture models. Whether or not maternal obesity impacts on offspring adipogenesis in vivo remains to be fully established. Furthermore, in vivo adipogenic differentiation has been shown to happen at distinct time periods, one during development (developmental adipogenesisāwhich is complete by 4 weeks of age in mice) and another in adulthood in response to feeding a high-fat (HF) diet (obesogenic adipogenesis). We therefore set out to determine whether maternal obesity impacted on offspring adipocyte hyperplasia in vivo and whether maternal obesity impacted on developmental or obesogenic adipogenesis, or both. Our findings reveal that maternal obesity is associated with enhanced obesogenic adipogenesis in HF-fed offspring. Interestingly, in newly weaned (4-week-old) offspring, maternal obesity is associated with adipocyte hypertrophy, but there were no changes in adipocyte number. Our results suggest that maternal obesity impacts on offspring obesogenic adipogenesis but does not affect developmental adipogenesis
Very high prevalence of 25-hydroxyvitamin D deficiency in 6433 UK South Asian adults : Analysis of the UK Biobank Cohort
Acknowledgements This research has been conducted using the UK Biobank Resource under application number 15168. This work was supported by in-house funds from the University of Surrey for payment of the UK Biobank access fee. The UK Biobank was established by the Wellcome Trust medical charity, Medical Research Council, Department of Health, Scottish Government and the Northwest Regional Development Agency. It has also had funding from the Welsh Assembly Government and the British Heart Foundation. UK Biobank is hosted by the University of Manchester and supported by the National Health Service (NHS). All the above funders had no role in the design, analysis or writing of the present study. Author contributions were as follows: Formulating the research question(s) (A. L. D., D. J. B., K. R. A., S. L. N.), designing the study (A. L. D., D. J. B., K. R. A., S. A. L.-N.), data collection (not applicable), analysing the data (A. L. D., D. J. B., K. R. A., S. A. L.-N.) and writing the article (A. L. D., D. J. B., K. R. A., S. L. N.). S. A. L.-N. discloses that she is Research Director of D3-TEX limited which holds the UK and Gulf Corporation Council (GCC) patents for the use of UVB transparent clothing to prevent vitamin D deficiency. S. A. L.-N.ās husband William Lanham-New is Managing Director of D3-TEX limited. S. A. L.-N. has received grants from (1) The UK Biotechnology and Biological Sciences Research Council (BBSRC) (project: Ergocalciferol (D2) v. Cholecalciferol (D3) Food Fortification: Comparative Efficiency in Raising 25OHD Status & Mechanisms of Action (D2āD3 Study), BB/I006192/1, Ā£516 823); (2) The UK Food Standards Agency (Project: Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England (D-FINES) Study, N05064, Ā£600 000); (3) The European Union (Project: Food Based Solutions for optimal vitamin D nutrition and health through the life cycle, Lead Work Package; (4) nutritional requirements for vitamin D during pregnancy, childhood and adolescence using RCTs, FP7-613977-ODIN, Euro 6Ā·2 million) and (5) The UK Ministry of Defence (MoD, Ā£2Ā·4 million). S. L. N. is a current member of the Scientific Advisory Committee for Nutrition (SACN) and a member of the panel who was responsible for the most recent revision of vitamin D recommended nutritional intake guidelines in the UK. She is a board member for the UK Royal Osteoporosis Society and the British Nutrition Foundation. She is Secretary of the Nutrition Society as well as Editor in Chief of the Nutrition Society textbook series. All other authors have no conflict of interest.Peer reviewedPublisher PD
Is there a role for vitamin C in preventing osteoporosis and fractures?:A review of the potential underlying mechanisms and current epidemiological evidence
Osteoporosis and related fractures are a major global health issue, but there are few preventative strategies. Previously reported associations between higher intakes of fruits and vegetables and skeletal health have been suggested to be partly attributable to vitamin C. To date, there is some evidence for a potential role of vitamin C in osteoporosis and fracture prevention but an overall consensus of published studies has not yet been drawn. The present review aims to provide a summary of the proposed underlying mechanisms of vitamin C on bone and reviews the current evidence in the literature, examining a potential link between vitamin C intake and status with osteoporosis and fractures. The Bradford Hill criteria were used to assess reported associations. Recent animal studies have provided insights into the involvement of vitamin C in osteoclastogenesis and osteoblastogenesis, and its role as a mediator of bone matrix deposition, affecting both the quantity and quality of bone collagen. Observational studies have provided some evidence for this in the general population, showing positive associations between dietary vitamin C intake and supplements and higher bone mineral density or reduced fracture risk. However, previous intervention studies were not sufficiently well designed to evaluate these associations. Epidemiological data are particularly limited for vitamin C status and for fracture risk and good-quality randomised controlled trials are needed to confirm previous epidemiological findings. The present review also highlights that associations between vitamin C and bone health may be non-linear and further research is needed to ascertain optimal intakes for osteoporosis and fracture prevention
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Proceedings of the Rank Forum on Vitamin D
The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations . 75 nmol/l). Any discussion of āoptimalā concentration of serum 25(OH)D needs to define āoptimalā with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted
concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations
Building a GPS Receiver for Space Lessons Learned
Over the past 4 years the Component Systems and Hardware branch at NASA GSFC has pursued an inhouse effort to build a unique space-flight GPS receiver. This effort has resulted in the Navigator GPS receiver. Navigator's first flight opportunity will come with the STS-125 HST-SM4 mission in August 2008. This paper covers the overall hardware design for the receiver and the difficulties encountered during the transition from the breadboard design to the final flight hardware design. Among the different lessons learned, the paper stresses the importance of selecting and verifying parts that are appropriate for space applications, as well as what happens when these parts are not accurately characterized by their datasheets. Additionally, the paper discusses what analysis needs to be performed when deciding system frequencies and filters. The presentation also covers how to prepare for thermal vacuum testing, and problems that may arise during vibration testing. It also contains what criteria should be considered when determining which portions of a design to create in-house, and which portions to license from a third party. Finally, the paper shows techniques which have proven to be extraordinarily helpful in debugging and analysis
Vitamin D Status of the British African-Caribbean Residents : Analysis of the UK Biobank Cohort
Funding: This work is part of the PhD of R.M.V., which is funded by the Universities Global Partā nership Network, coāsupervised by the Universities of Surrey and Wollongong. Funders did not have a role in the study. The researchers are independent to the funders. All authors take responsibility for the integrity of the data and the accuracy of the data analysis.Peer reviewedPublisher PD
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