509 research outputs found

    Ribosome recycling induces optimal translation rate at low ribosomal availability

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    Funding statement The authors thank BBSRC (BB/F00513/X1, BB/I020926/1 and DTG) and SULSA for funding. Acknowledgement The authors thank R. Allen, L. Ciandrini, B. Gorgoni and P. Greulich for very helpful discussions and careful reading of the manuscript.Peer reviewedPublisher PD

    A three-dimensional finite element model of maximal grip loading in the human wrist

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    The aim of this work was to create an anatomically accurate three-dimensional finite element model of the wrist, applying subject-specific loading and quantifying the internal load transfer through the joint during maximal grip. For three subjects, representing the anatomical variation at the wrist, loading on each digit was measured during a maximal grip strength test with simultaneous motion capture. The internal metacarpophalangeal joint load was calculated using a biomechanical model. High-resolution magnetic resonance scans were acquired to quantify bone geometry. Finite element analysis was performed, with ligaments and tendons added, to calculate the internal load distribution. It was found that for the maximal grip the thumb carried the highest load, an average of 72.2 ¡ 20.1 N in the neutral position. Results from the finite element model suggested that the highest regions of stress were located at the radial aspect of the carpus. Most of the load was transmitted through the radius, 87.5 per cent, as opposed to 12.5 per cent through the ulna with the wrist in a neutral position. A fully three-dimensional finite element analysis of the wrist using subject-specific anatomy and loading conditions was performed. The study emphasizes the importance of modelling a large ensemble of subjects in order to capture the spectrum of the load transfer through the wrist due to anatomical variation

    TEACHING IN A CONNECTED WORLD: NEW APPROACHES IN TEACHING BIOCHEMISTRY ADOPTED AT THE MEDICAL UNIVERSITY OF VARNA, BULGARIA

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    This paper aims at improving the content of the biochemistry curriculum and the methods by which it was delivered at the Medical University of Varna in terms of course content, examination standards and obtaining a feedback from the students. The paper presents two-year follow-up outcomes. A working collaboration was established with two Western European Universities, the University of Marburg, Germany and the University of Dundee, UK. The innovative teaching methodology developed and used in the Department of Biochemistry at the University of Dundee was adopted considering the particular circumstances in the Medical University of Varna. The content of the basic biochemistry course was revised and expanded emphasizing the molecular basis of metabolic variation between different organs and molecular events and clinical medicine. New clinically case-oriented studies of biochemically-based disorders were introduced for the first time in the basic biochemistry course in the form of tutorials and discussion sessions with the students. The laboratory classes in biochemistry were deleted and replaced by demonstrations and clinical laboratory tests, together with tutorial and group activity sessions. New interactive small group methods were adopted in our teaching with the aim to ensure better understanding and accessibility of the teaching material. One free elective discipline entitled "Molecular biology in medicine" has been introduced. A system for obtaining students' opinions about the courses and new teaching methods using feedback questionnaires was adopted

    Social Values Related to the Development of Health and Care Guidance: Literature review for NICE by its Research Support Unit. Report of the Research Support Unit for the National Institute for Health and Care Excellence

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    The National Institute for Health and Care Excellence develops guidance for the allocation of resources for services in clinical and public health and social care. It has a policy of social values underpinning this work that was last updated in 2008. This report is of a review of the literature on social values to help inform the further updating of this policy. The review involved a semi iterative search for literature that was then screened for ideas relevant to health and care guidance. These ideas and the main issues they raise are reported under eight major social value categories. Twenty one themes arising from the review are also provided. The literature raises many issues about the nature of social values that can be applied to guidance development. It needs to be emphasized that not all of these issues should necessarily be applied to guidance development. They are simply issues that have been raised in the literature and this review provides an opportunity for them to be considered. Many of the ideas that have been proposed are in tension with each other and could not all be achieved. It should also be emphasized that many of the issues raise considerable practical challenges in terms of methods, data and financial and timeliness. The review does not assume that any of these issues or ideas could or should necessarily be part of NICE’s policy on social values in guidance production. The review simply provides a list of ideas, issues and themes from the literature for consideration

    Total hip arthroplasty improves pain and function but not physical activity

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    Background: People with hip osteoarthritis are likely to limit physical activity (PA) engagement due to pain and lack of function. Total hip arthroplasty (THA) reduces pain and improves function, potentially allowing increased PA. PA of THA patients was quantified to 12m post-operation. The hypothesis was that post-operatively levels of PA would increase. Methods: PA of 30 THA patients (67±7 years) was objectively measured pre-operatively and three and 12 months post-operation. Harris Hip Score (HHS), Oxford Hip Score (OHS) and six minute walk test (6MWT) were recorded. Mixed linear modelling was used to examine relationships of outcomes with time, baseline BMI, age, gender and baseline HHS. Results: Time was not a significant factor in predicting volume measures of PA, including sit-to-stand transitions, upright time and steps. Notably baseline BMI was a significant predictor of upright time, steps, largest number of steps in an upright bout, HHS and 6MWT. Baseline HHS helped predict longest upright bout, cadence of walking bouts >60s and OHS. The significant effect of participant as a random intercept in the model for PA outcomes suggested habituation from pre- to post-surgery. Conclusions: Volume measures of PA did not change from pre- to 12m post-surgery despite improvement in HHS, OHS and 6MWT. Baseline BMI was a more important predictor of upright activity and stepping than time. Pre- and post-operative PA promotion could be used to modify apparently habitual low levels of PA to enable full health benefits of THA to be gained

    Unique Residues Involved in Activation of the Multitasking Protease/Chaperone HtrA from Chlamydia trachomatis

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    DegP, a member of the HtrA family of proteins, conducts critical bacterial protein quality control by both chaperone and proteolysis activities. The regulatory mechanisms controlling these two distinct activities, however, are unknown. DegP activation is known to involve a unique mechanism of allosteric binding, conformational changes and oligomer formation. We have uncovered a novel role for the residues at the PDZ1:protease interface in oligomer formation specifically for chaperone substrates of Chlamydia trachomatis HtrA (DegP homolog). We have demonstrated that CtHtrA proteolysis could be activated by allosteric binding and oligomer formation. The PDZ1 activator cleft was required for the activation and oligomer formation. However, unique to CtHtrA was the critical role for residues at the PDZ1:protease interface in oligomer formation when the activator was an in vitro chaperone substrate. Furthermore, a potential in vivo chaperone substrate, the major outer membrane protein (MOMP) from Chlamydia, was able to activate CtHtrA and induce oligomer formation. Therefore, we have revealed novel residues involved in the activation of CtHtrA which are likely to have important in vivo implications for outer membrane protein assembly

    Graphene nanoribbon-TiO2-quantum dots hybrid photoanode to boost the performance of photoelectrochemical for hydrogen generation

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    We report the effect of incorporation of graphene nanoribbons (GNR) into a TiO2 mesoporous film sensitized with colloidal CdSe/CdS core/shell quantum dots (QDs) on the efficiency and long-term stability of a photoelectrochemical (PEC) cell for hydrogen (H2) generation. The GNR-TiO2 hybrid photoanodes were prepared by using simple, low-cost and large-area scalable doctor-blade method. The presence of GNR in the hybrid photoanode was confirmed by ultraviolet-visible absorption measurements, scanning electron microscopy and Raman spectroscopy. Our results demonstrate that an optimum loading of 0.02 wt% GNR increases the photocurrent density (at 0.8 V vs RHE) of the PEC device up to 5.51 mA/cm2, which is 30% higher than that of the control device. This improvement in photocurrent density can be attributed to enhanced electron transport (reduced charge transport resistance) in GNR-TiO2 hybrid anodes as confirmed by electrochemical impedance spectroscopy. In addition, PEC cells based on GNRs-TiO2/QDs hybrid photoanode maintain ∼65% of the initial photocurrent density after 7200 s of continuous one sun illumination, which is 15% higher than PEC cell based on a standard TiO2/QDs photoanode. Our findings offer a simple, large area scalable and low-cost approach to fabricate photoanode for high-performance optoelectronic devices, such as improving the performance of PEC cells for hydrogen generation

    CuS/graphene nanocomposite as a transparent conducting oxide and pt-free counter electrode for dye-sensitized solar cells

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    We report a simple, low temperature and solution-processable approach to prepare a composite film of copper sulfide/graphene (CuS-G) as a transparent conducting oxide (TCO) and platinum (Pt)-free CE for Dye-Sensitized Solar Cells (DSSCs). We find that CuS with 3.3 vol% of graphene (CuS-3G) yields the highest power conversion efficiency (PCE) of 4.83%, which is about 12% higher than DSSCs based on CEs made of pristine CuS. After optimizing the graphene concentration, the PCE of the DSSC assembled with the optimized CuS-3G is comparable to that based on Pt CE. The similar performance of the CuS-3G CE compared with Pt CE is mainly attributed to the small series resistance and high electrocatalytic activity of the CuS-3G CE; this is confirmed by cyclic voltammetry and electrochemical impedance spectroscopy. These results indicate a straightforward methodology for the low cost and easy synthesis of an alternative CE in DSSCs
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