1,101 research outputs found
Percolation model for structural phase transitions in LiHIO mixed crystals
A percolation model is proposed to explain the structural phase transitions
found in LiHIO mixed crystals as a function of the
concentration parameter . The percolation thresholds are obtained from Monte
Carlo simulations on the specific lattices occupied by lithium atoms and
hydrogen bonds. The theoretical results strongly suggest that percolating
lithium vacancies and hydrogen bonds are indeed responsible for the solid
solution observed in the experimental range .Comment: 4 pages, 2 figure
TUIs vs. GUIs : comparing the learning potential with preschoolers
In an effort to better understand the learning
potential of a tangible interface, we conducted a comparison study between a tangible and a traditional graphical user interface for teaching preschoolers (In Portugal, children enter preschool at the age of three and they attend it till entering school, normally at the age of six) about good oral hygiene. The study was carried with two groups of children aged 4 to 5 years. Questionnaires to parents, children’s drawings, and interviews were used for data collection and analysis and revealed important indicators about children’s change of attitude, involvement, and preferences for the interfaces. The questionnaires showed a remarkable change of attitude toward tooth brushing in the children that interacted with the tangible interface; particularly children’s motivation increased significantly. Children’s drawings were used to assess their degree of involvement with the interfaces. The drawings from the children that interacted with the tangible interface were very complete and detailed suggesting that the children felt actively involved with the experience. The results suggest that the tangible interface was capable of promoting a stronger and long-lasting involvement having a greater potential to engage children, therefore potentially promoting learning. Evaluation through drawing seems to be a promising method to work with preliterate children; however,it is advisable to use it together with other methods.Fundação para a Ciência e Tecnologia (FCT
Neuroprotection in a Novel Mouse Model of Multiple Sclerosis
The authors acknowledge the support of the Barts and the London Charity, the Multiple Sclerosis Society of Great Britain and Northern Ireland, the National Multiple Sclerosis Society, USA, notably the National Centre for the Replacement, Refinement & Reduction of Animals in Research, and the Wellcome Trust (grant no. 092539 to ZA). The siRNA was provided by Quark Pharmaceuticals. The funders and Quark Pharmaceuticals had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Genetic Background Can Result in a Marked or Minimal Effect of Gene Knockout (GPR55 and CB2 Receptor) in Experimental Autoimmune Encephalomyelitis Models of Multiple Sclerosis
PMCID: PMC379391
Recommended from our members
Shared and distinct transcriptional programs underlie the hybrid nature of iNKT cells
Invariant natural killer T cells (iNKT cells) are innate-like T lymphocytes that act as critical regulators of the immune response. To better characterize this population, we profiled gene expression in iNKT cells during ontogeny and in peripheral subsets as part of the Immunological Genome Project. High-resolution comparative transcriptional analyses defined developmental and subset-specific programs of gene expression by iNKT cells. In addition, we found that iNKT cells shared an extensive transcriptional program with NK cells, similar in magnitude to that shared with major histocompatibility complex (MHC)-restricted T cells. Notably, the program shared by NK cells and iNKT cells also operated constitutively in γδ T cells and in adaptive T cells after activation. Together our findings highlight a core effector program regulated distinctly in innate and adaptive lymphocytes
A new internally heated diamond anvil cell system for time-resolved optical and x-ray measurements
We have developed a new internally heated diamond anvil cell (DAC) system for in situ high-pressure and high-temperature x-ray and optical experiments. We have adopted a self-heating W/Re gasket design allowing for both sample confinement and heating. This solution has been seldom used in the past but proved to be very efficient to reduce the size of the heating spot near the sample region, improving heating and cooling rates as compared to other resistive heating strategies. The system has been widely tested under high-temperature conditions by performing several thermal emission measurements. A robust relationship between electric power and average sample temperature inside the DAC has been established up to about 1500 K by a measurement campaign on different simple substances. A micro-Raman spectrometer was used for various in situ optical measurements and allowed us to map the temperature distribution of the sample. The distribution resulted to be uniform within the typical uncertainty of these measurements (5% at 1000 K). The high-temperature performances of the DAC were also verified in a series of XAS (x-ray absorption spectroscopy) experiments using both nano-polycrystalline and single-crystal diamond anvils. XAS measurements of germanium at 3.5 GPa were obtained in the 300 K-1300 K range, studying the melting transition and nucleation to the crystal phase. The achievable heating and cooling rates of the DAC were studied exploiting a XAS dispersive setup, collecting series of near-edge XAS spectra with sub-second time resolution. An original XAS-based dynamical temperature calibration procedure was developed and used to monitor the sample and diamond temperatures during the application of constant power cycles, indicating that heating and cooling rates in the 100 K/s range can be easily achieved using this device
Sur les entiers ellipséphiques: somme des chiffres et répartition dans les classes de congruence
A bispecific monomeric nanobody induces spike trimer dimers and neutralizes SARS-CoV-2 in vivo
Experiments with replication-competent SARS-CoV-2 were performed in the Biomedicum BSL3 core facility, Karolinska Institutet. We thank Jonas Klingström for providing Calu-3 cells and sharing the Swedish SARS-CoV-2 isolate, and Alex Sigal from the Africa Health Research Institute for providing the beta variant (B.1.351/501Y.V2) isolate. We thank Penny Moore and the NICD (South Africa) for providing the B.1.351/beta variant spike plasmid, which was generated using funding from the South African Medical Research Council. We gratefully acknowledge the G2P-UK National Virology consortium funded by MRC/UKRI (grant ref: MR/W005611/1.) and the Barclay Lab at Imperial College for providing the B.1.617.2 spike plasmid. All cryo-EM data were collected in the Karolinska Institutet’s 3D-EM facility. We thank Agustin Ure for assistance with figure generation and Tomas Nyman (Protein Science Facility at KI) for providing access to SPR instruments. L.H. was supported by the David och Astrid Hageléns stiftelse, the Clas Groschinskys Minnesfond and a Jonas Söderquist’s scholarship. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 101003653 (CoroNAb), to B.M. and G.M.M. B.M.H. is supported by the Knut and Alice Wallenberg Foundation (KAW 2017.0080 and KAW 2018.0080). The work was supported by project grants from the Swedish Research Council to E.S. (2020-02682), B.M.H. (2017-6702 and 2018-3808), B.M. (2018-02381) and to G.M.M. (2018-03914 and 2018-03843). E.S. is supported by Karolinska Institutet Foundation Grants, National Molecular Medicine Program Grants, and the grants from the SciLifeLab National COVID-19 Research Program, financed by the Knut and Alice Wallenberg Foundation. We thank National Microscopy Infrastructure, NMI (VR-RFI 2016-00968).N
Interleukin-21 Is Required for the Development of Type 1 Diabetes in NOD Mice
OBJECTIVE: Interleukin (IL)-21 is a type 1 cytokine that has been implicated in the pathogenesis of type 1 diabetes via the unique biology of the nonobese diabetic (NOD) mouse strain. The aim of this study was to investigate a causal role for IL-21 in type 1 diabetes. RESEARCH DESIGN AND METHODS: We generated IL-21R–deficient NOD mice and C57Bl/6 mice expressing IL-21 in pancreatic β-cells, allowing the determination of the role of insufficient and excessive IL-21 signaling in type 1 diabetes. RESULTS: Deficiency in IL-21R expression renders NOD mice resistant to insulitis, production of insulin autoantibodies, and onset of type 1 diabetes. The lymphoid compartment in IL-21R−/− NOD is normal and does not contain an increased regulatory T-cell fraction or diminished effector cytokine responses. However, we observed a clear defect in autoreactive effector T-cells in IL-21R−/− NOD by transfer experiments. Conversely, overexpression of IL-21 in pancreatic β-cells induced inflammatory cytokine and chemokines, including IL-17A, IL17F, IFN-γ, monocyte chemoattractant protein (MCP)-1, MCP-2, and interferon-inducible protein-10 in the pancreas. The ensuing leukocytic infiltration in the islets resulted in destruction of β-cells and spontaneous type 1 diabetes in the normally diabetes-resistant C57Bl/6 and NOD × C57Bl/6 backgrounds. CONCLUSIONS: This work provides demonstration of the essential prodiabetogenic activities of IL-21 on diverse genetic backgrounds (NOD and C57BL/6) and indicates that IL-21 blockade could be a promising strategy for interventions in human type 1 diabetes
- …
