117 research outputs found
Tunable thermal expansion in framework materials through redox intercalation
Thermal expansion properties of solids are of fundamental interest and control of thermal
expansion is important for practical applications but can be difficult to achieve. Many
framework-type materials show negative thermal expansion when internal cages are empty
but positive thermal expansion when additional atoms or molecules fill internal voids present.
Here we show that redox intercalation offers an effective method to control thermal
expansion from positive to zero to negative by insertion of Li ions into the simple negative
thermal expansion framework material ScF3, doped with 10% Fe to enable reduction. The
small concentration of intercalated Li ions has a strong influence through steric hindrance of
transverse fluoride ion vibrations, which directly controls the thermal expansion. Redox
intercalation of guest ions is thus likely to be a general and effective method for controlling
thermal expansion in the many known framework materials with phonon-driven negative
thermal expansion
Risk of Violent Crime in Individuals with Epilepsy and Traumatic Brain Injury: A 35-Year Swedish Population Study
Seena Fazel and colleagues report findings from a longitudinal follow-up study in Sweden that evaluated the risks of violent crime subsequent to hospitalization for epilepsy, or traumatic brain injury. The researchers control for familial confounding with sibling controls. The analyses call into question an association between epilepsy and violent crime, although they do suggest that there may be a relationship between traumatic brain injury and violent crime
Cell-Intrinsic NF-ÎșB Activation Is Critical for the Development of Natural Regulatory T Cells in Mice
regulatory T (Treg) cells develop in the thymus and represent a mature T cell subpopulation critically involved in maintaining peripheral tolerance. The differentiation of Treg cells in the thymus requires T cell receptor (TCR)/CD28 stimulation along with cytokine-promoted Foxp3 induction. TCR-mediated nuclear factor kappa B (NF-ÎșB) activation seems to be involved in differentiation of Treg cells because deletion of components of the NF-ÎșB signaling pathway, as well as of NF-ÎșB transcription factors, leads to markedly decreased Treg cell numbers in thymus and periphery. thymic Treg precursors and their further differentiation into mature Treg cells. Treg cell development could neither be completely rescued by the addition of exogenous Interleukin 2 (IL-2) nor by the presence of wild-type derived cells in adoptive transfer experiments. However, peripheral NF-ÎșB activation appears to be required for IL-2 production by conventional T cells, thereby participating in Treg cell homeostasis. Moreover, pharmacological NF-ÎșB inhibition via the IÎșB kinase ÎČ (IKKÎČ) inhibitor AS602868 led to markedly diminished thymic and peripheral Treg cell frequencies.Our results indicate that Treg cell-intrinsic NF-ÎșB activation is essential for thymic Treg cell differentiation, and further suggest pharmacological NF-ÎșB inhibition as a potential therapeutic approach for manipulating this process
International Consensus Statement on Rhinology and Allergy: Rhinosinusitis
Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICARâRS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICARâRSâ2021 as well as updates to the original 140 topics. This executive summary consolidates the evidenceâbased findings of the document. Methods: ICARâRS presents over 180 topics in the forms of evidenceâbased reviews with recommendations (EBRRs), evidenceâbased reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICARâRSâ2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidenceâbased management algorithm is provided. Conclusion: This ICARâRSâ2021 executive summary provides a compilation of the evidenceâbased recommendations for medical and surgical treatment of the most common forms of RS
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