49 research outputs found
Conceptualising spaced learning in health professions education: A scoping review
Objectives To investigate the definitions and applications of 'spaced learning' and to propose future directions for advancing its study and practice in health professions education. Method The authors searched five online databases for articles published on spaced learning in health professions education prior to February 2018. Two researchers independently screened articles for eligibility with set inclusion criteria. They extracted and analysed key data using both quantitative and qualitative methods. Results Of the 2972 records retrieved, 120 articles were included in the review. More than 90% of these articles were published in the last 10 years. The definition of spaced learning varied widely and was often not theoretically grounded. Spaced learning was applied in distinct contexts, including online learning, simulation training and classroom settings. There was a large variety of spacing formats, ranging from dispersion of information or practice on a single day, to intervals lasting several months. Generally, spaced learning was implemented in practice or testing phases and rarely during teaching. Conclusions Spaced learning is infrequently and poorly defined in the health professions education literature. We propose a comprehensive definition of spaced learning and emphasise that detailed descriptions of spacing formats are needed in future research to facilitate the operationalisation of spaced learning research and practice in health professions education.Cardiolog
Gene Expression Signatures That Predict Radiation Exposure in Mice and Humans
BACKGROUND: The capacity to assess environmental inputs to biological phenotypes is limited by methods that can accurately and quantitatively measure these contributions. One such example can be seen in the context of exposure to ionizing radiation. METHODS AND FINDINGS: We have made use of gene expression analysis of peripheral blood (PB) mononuclear cells to develop expression profiles that accurately reflect prior radiation exposure. We demonstrate that expression profiles can be developed that not only predict radiation exposure in mice but also distinguish the level of radiation exposure, ranging from 50 cGy to 1,000 cGy. Likewise, a molecular signature of radiation response developed solely from irradiated human patient samples can predict and distinguish irradiated human PB samples from nonirradiated samples with an accuracy of 90%, sensitivity of 85%, and specificity of 94%. We further demonstrate that a radiation profile developed in the mouse can correctly distinguish PB samples from irradiated and nonirradiated human patients with an accuracy of 77%, sensitivity of 82%, and specificity of 75%. Taken together, these data demonstrate that molecular profiles can be generated that are highly predictive of different levels of radiation exposure in mice and humans. CONCLUSIONS: We suggest that this approach, with additional refinement, could provide a method to assess the effects of various environmental inputs into biological phenotypes as well as providing a more practical application of a rapid molecular screening test for the diagnosis of radiation exposure
Much Ado About the TPPās Effect on Pharmaceuticals
Ocular antigens are sequestered behind the blood-retina barrier and the ocular environment protects ocular tissues from autoimmune attack. The signals required to activate autoreactive T cells and allow them to cause disease in the eye remain in part unclear. In particular, the consequences of peripheral presentation of ocular antigens are not fully understood. We examined peripheral expression and presentation of ocular neo-self-antigen in transgenic mice expressing hen egg lysozyme (HEL) under a retina-specific promoter. High levels of HEL were expressed in the eye compared to low expression throughout the lymphoid system. Adoptively transferred naĆÆve HEL-specific CD4+ T cells proliferated in the eye draining lymph nodes, but did not induce uveitis. By contrast, systemic infection with a murine cytomegalovirus (MCMV) engineered to express HEL induced extensive proliferation of transferred naĆÆve CD4+ T cells, and significant uveoretinitis. In this model, wild-type MCMV, lacking HEL, did not induce overt uveitis, suggesting that disease is mediated by antigen-specific peripherally activated CD4+ T cells that infiltrate the retina. Our results demonstrate that retinal antigen is presented to T cells in the periphery under physiological conditions. However, when the same antigen is presented during viral infection, antigen-specific T cells access the retina and autoimmune uveitis ensues
Electro hydrodynamic pumping of liquids in microchannels
This paper describes the concept of Electrohydrodynamic (EHD) pumping in microchannels and the study of EHD pumps in IntelliSuiteās Microfluidic simulation module. The EHD pump study focuses on the factors influencing the velocity of fluid flow such as the conductivity of the fluid, the frequency of the driving AC voltage, the phase of the driving signal, the dimensions of the electrode, the gap between the electrodes and the the number of driving electrodes. The results from the simulation will be used to characterize the presented design of the EHD pump. The presented design for the study of the EHD pump has a microchannel with a length of 0.2mm, width of 0.08mm and a thickness of 0.08mm. The width of the driving electrodes present at the bottom of the channel is 0.01mm and the gap between the electrodes is 0.04mm
Inducible costimulator-dependent IL-10 production by regulatory T cells specific for self-antigen
In this study, we investigated the relationship between the expression levels of self-antigen and the function of self-reactive T cells in the periphery. To this end, we used two rat insulin promoter-ovalbumin (RIP-OVA) transgenic mice (RIP-OVA(high), RIP-OVA(low)) in which was produced only in pancreatic Ī²-islet cells. The OVA-producing transgenic mice were crossed to DO.11.10 (DO) mice expressing a T cell antigen receptor specific for OVA(323ā339). The responsiveness of peripheral CD4(+) T cells in the double transgenic mice was examined. We demonstrated that hyporesponsive but highly IL-10-producing T cells were developed in DO Ć OVA(high) mice only, not in DO Ć OVA(low) mice. These IL-10-producing T cells exhibited regulatory activity both in in vitro and in vivo experiments. Moreover, these IL-10-producing regulatory T (Tr) cells expressed high levels of inducible costimulator (ICOS) before in vitro stimulation. Blockade of ICOS-signaling inhibited the production of IL-10 and abrogated the inhibitory function of these Tr cells. Thus, these results suggested that the development of IL-10-producing Tr cells depends on the expression levels of self-antigen in vivo and that ICOS signal plays a critical role in immune regulation by IL-10-producing Tr cells in self-tolerance