High performance fluoroelastomer composites filled withgraphite and/or bismuth oxide for applications ingamma-ray shielding

Fluoroelastomer-based composites with nano-sized bismuth oxide (B) and/orgraphite (G) as fillers were prepared and characterized using FKM type 1 fluoroe-lastomer as a matrix. The effects of these fillers used singly or in combination onthe crosslinking process, mechanical, thermal, dynamic mechanical, electrical,optical, and high-energy radiation attenuation properties of FKM were investi-gated. The results showed that graphite significantly increased the moduli E50(MPa) of FKM/G and FKM/GB composites by 1026% and 1459%, respectively,compared to FKM. On the other hand, bismuth(III) oxide did not affect the stiff-ness or elongation at break of FKM significantly. Graphite also imparted electricalconductivity to FKM (10 6Scm 1), which was reduced by bismuth oxide to10 12Scm 1. Furthermore, the linear attenuation coefficients (μ), half-value layer(HVL), and tenth-value layer (THV) ofpure FKM and FKM composites were eval-uated using a137Cs (662 keV) source, revealing that FKM/B and FKM/GB com-posites show 47.4% and 35.8% higherμvalues, respectively, than FKM. Takinginto consideration that the attenuation coefficient of FKM is 10 times higher thanconventional elastomers such as natural rubber, these results indicate that thinflexible shielding against high electromagnetic radiation can be achieved to pro-tect different sensitive equipment such as electronic devices used in nuclear powerplants, gamma radiation facilities, telescopes, and artificial satellites.Projects for Initiation in Research ANID-FONDECYT, Grant/Award Numbers:11200919, 11200437; ANID-FONDECYTRegular Project, Grant/Award Number:1221364 and 1191566; ANID—Millennium Science Initiative Program,Grant/Award Number: ICN2019_044;ANID BECAS/DOCTORADONACIONAL, Grant/Award Number:21211480Peer reviewe

Development of disposable carbon nanofibers electrodes supported on filters

Junta de Castilla yLeýn (GR71, BU349-U13) and the Ministerio de Economa yCompetitividad(CTQ2014-55583-R, CTQ2014-61914-EXP

Leukoencephalopathy resolution after atypical mycobacterial treatment: a case report

Abstract\ud \ud Background\ud Association of leukoencephalopathy and atypical mycobacteriosis has been rarely reported. We present a case that is relevant for its unusual presentation and because it may shed further light on the pathogenic mechanisms underlying reversible encephalopathies.\ud \ud \ud Case report\ud We report the case of a Hispanic 64-year-old woman with cognitive decline and extensive leukoencephalopathy. Magnetic resonance imaging revealed white-matter lesions with increased water diffusivity, without blood–brain-barrier disruption. Brain biopsy showed tissue rarefaction with vacuolation, mild inflammation, few reactive astrocytes and decreased aquaporin water-channel expression in the lesions. Six months later, she was diagnosed with atypical mycobacterial pulmonary infection. Brain lesions resolved after antimycobacterial treatment.\ud \ud \ud Conclusion\ud We hypothesize leukoencephalopathic changes and vasogenic edema were associated with decreased aquaporin expression. Further studies should clarify if reversible leukoencephalopathy has a causal relationship with decreased aquaporin expression and atypical mycobacterial infection, and mechanisms underlying leukoencephalopathy resolution after antimycobacterial treatment. This article may contribute to the understanding of pathogenic mechanisms underlying magnetic resonance imaging subcortical lesions and edema, which remain incompletely understood.Ministry of Education, Culture, Sports, Science and Technology (MEXT) of JapanHealth and Labor Sciences Research Grant on Intractable Diseases\ud (Neuroimmunological Diseases) from the Ministry of Health, Labor and\ud Welfare of Japa