401 research outputs found

    Sensitive X-ray Detectors Synthesised from CsPbBr3

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    The materials used in detection of high energy photons are of primary importance in the construction of efficient, cost effective and sensitive detectors. Current research into Perovskites for solar cell technology has stimulated interest in their potential alternative uses, one of which is in direct photon conversion radiation detectors, owed primarily to their high-Z elemental composition twinned with exceptional charge carrier transport properties. Here, the Perovskite CsPbBr 3 has been synthesised through solution growth. The raw CsPbBr 3 was a granular powder which was formed into disks of 8 mm diameter and 1-2 mm thickness by two methods: 1). the powders were pressed into pellets using a hydraulic press or 2). sealed in a quartz ampoule under vacuum and then melted and quenched to form a polycrystalline solid which was cut to size. Metallic contacts were deposited on the front and back faces to permit charge collection. The results from the pressed devices are promising, particularly given that the production method is cost effective, repeatable and scalable. The solid-from-melt devices show similar performance but further development is required to optimise the production method

    Paradoxical aortic stiffening and subsequent cardiac dysfunction in Hutchinson-Gilford progeria syndrome

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    [EN] Hutchinson-Gilford progeria syndrome (HGPS) is an ultra-rare disorder with devastating sequelae resulting in early death, presently thought to stem primarily from cardiovascular events. We analyse novel longitudinal cardiovascular data from a mouse model of HGPS (Lmna(G609G/G609G)) using allometric scaling, biomechanical phenotyping, and advanced computational modelling and show that late-stage diastolic dysfunction, with preserved systolic function, emerges with an increase in the pulse wave velocity and an associated loss of aortic function, independent of sex. Specifically, there is a dramatic late-stage loss of smooth muscle function and cells and an excessive accumulation of proteoglycans along the aorta, which result in a loss of biomechanical function (contractility and elastic energy storage) and a marked structural stiffening despite a distinctly low intrinsic material stiffness that is consistent with the lack of functional lamin A. Importantly, the vascular function appears to arise normally from the low-stress environment of development, only to succumb progressively to pressure-related effects of the lamin A mutation and become extreme in the peri-morbid period. Because the dramatic life-threatening aortic phenotype manifests during the last third of life there may be a therapeutic window in maturity that could alleviate concerns with therapies administered during early periods of arterial development.This work was supported, in part, by grants from the US National Institutes of Health: R01 HL105297 (J.D.H.) and P01 HL134605 (Dan Rifkin) and R01 AG047632 and R33 ES025636 (G.S.S.)Murtada, SI.; Kawamura, Y.; Caulk, AW.; Ahmadzadeh, H.; Mikush, N.; Zimmerman, K.; Kavanagh, D.... (2020). Paradoxical aortic stiffening and subsequent cardiac dysfunction in Hutchinson-Gilford progeria syndrome. Journal of The Royal Society Interface. 17(166):1-12. https://doi.org/10.1098/rsif.2020.00661121716

    Molecular basis of FIR-mediated c-myc transcriptional control

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    The far upstream element (FUSE) regulatory system promotes a peak in the concentration of c-Myc during cell cycle. First, the FBP transcriptional activator binds to the FUSE DNA element upstream of the c-myc promoter. Then, FBP recruits its specific repressor (FIR), which acts as an on/off transcriptional switch. Here we describe the molecular basis of FIR recruitment, showing that the tandem RNA recognition motifs of FIR provide a platform for independent FUSE DNA and FBP protein binding and explaining the structural basis of the reversibility of the FBP-FIR interaction. We also show that the physical coupling between FBP and FIR is modulated by a flexible linker positioned sequentially to the recruiting element. Our data explain how the FUSE system precisely regulates c-myc transcription and suggest that a small change in FBP-FIR affinity leads to a substantial effect on c-Myc concentration.MRC Grant-in-aid U11757455

    Source solutions for the nonlinear diffusion-convection equation

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    Need for enforcement of ethicolegal education – an analysis of the survey of postgraduate clinical trainees

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    BACKGROUND: The number of medical lawsuits in Japan was between 14 and 21 each year before 1998, but increased to 24 to 35 per year after 1999. There were 210 lawsuits during this 10-year period. There is a need for skills and knowledge related to ethics, which is as fundamental to the practice of medicine as basic sciences or clinical skills. in Japan education in ethics is relatively rare and its importance is not yet recognized. Establishing ethics education using legal precedents, which has already been achieved in Western countries, will be a very important issue in Japan. In the present study, a questionnaire survey was conducted among graduate intern doctors, in order to investigate whether ethics education using precedents might have a positive effect in Japan. METHODS: In 2002, a questionnaire survey entitled Physicians' Clinical Ethics was carried out in a compulsory orientation lecture given to trainees before they started clinical practice in our hospital. The attendees at this lecture were trainees who came from colleges in various districts of Japan. During the lecture, 102 questionnaires were distributed, completed by attendees and collected. The recovery rate was 100%. The questionnaire consisted of 22 questions (in three categories), of which 20 were answered by multiple choices, and the other two were answered by description. The time required to complete the questionnaire was about 10 minutes. RESULTS: The recovered questionnaires were analyzed using statistical analysis software (SPSS for Windows, Release 10.07J-1/June/2000), in addition to simple statistical analysis. answers using multiple choices for the 20 questions in the questionnaire were input into SPSS. The principal component analysis was performed for each question. As a result, the item that came to the fore was "legal precedent". Since many intern doctors were interested in understanding laws and precedents, learning about ethical considerations through education using precedents might better meet with their needs and interests. CONCLUSION: We applied a new method in which the results of principal component analysis and frequencies of answers to other questions were combined. From this we deduced that the precedent education used in Western countries was useful to help doctors acquire ethical sensitivity and was not against their will. A relationship was found between reading precedents and the influence of lawsuits, and it was thought that student participation-type precedent education would be useful for doctors in order to acquire ethical sensitivity
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