Microwave absorption of magnesium/hydrogen-treated titanium dioxide nanoparticles

Interactions between materials and electromagnetic irradiations in the microwave frequency are critical for many civil and military applications, such as radar detection, communications, information processing and transport et al. Dipole rotations or magnetic domain resonance are the mainly traditional mechanisms for microwave absorption. The recent finding of the excellent microwave absorption from hydrogenated TiO2 nanoparticles provides us an alternative approach for achieving such absorption, by manipulating the structural defects inside nanoparticles through hydrogenation. In this study, we demonstrate that the microwave absorption can be not only achieved but fine-tuned with TiO2 nanoparticles thermally treated in a Mg/H2 environment. Their position and efficiency can be effectively controlled by the treating temperature. Specifically, the microwave absorption position shifts to the lower frequency region as the treating temperature increases, and there seems to exist an optimal treating temperature to obtain the maximum efficiency, as the absorbing efficiency first increases, and then decreases, with the increase in treatment temperature. Therefore, this study enriches our knowledge and understanding microwave absorption from TiO2-based nanomaterials which may inspire new ideas on other systems to enhance their performance as well.

Effects of epinephrine on angiogenesis-related gene expressions in cultured rat cardiomyocytes

Epinephrine is often used for the treatment of patients with heart failure, low cardiac output and cardiac arrest. It can acutely improve hemodynamic parameters; however, it does not seem to improve longer term clinical outcomes. Therefore, we hypothesized that epinephrine may induce unfavorable changes in gene expression of cardiomyocyte. Thus, we investigated effects of epinephrine exposure on the mediation or modulation of gene expression of cultured cardiomyocytes at a genome-wide scale. Our investigation revealed that exposure of cardiomyocytes to epinephrine in an in vitro environment can up-regulate the expression ofangiopoietin-2 gene （~ 2.1 times）, and down-regulate the gene expression of neuregulin 1 （-3.7 times）, plasminogen activator inhibitor-1 （-2.4 times） and SPARC-related modular calcium-binding protein-2 （-4.5 times）. These changes suggest that epinephrine exposure may induce inhibition of angiogenesis-related gene expressions in cultured rat cardiomyocytes. The precise clinical significance of these changes in gene expression, which was induced by epinephrine exposure, warrants further experimental and clinical investigations.

Recent progress of nanomaterials for microwave absorption

Microwave absorbing materials have received considerable interest over the years for their applications in stealth,communications,and information processing technologies.These materials often require functionalization at the nanoscale so to achieve desirable dielectric and magnetic properties which induce interaction with incident electromagnetic radiation.This article presents a comprehensive review on the recent research progress of nanomaterials for microwave absorption,including the basic mechanism of microwave absorption(e.g.,dielectric loss,magnetic loss,dielectric/magnetic loss coupling),measurement principle(e.g.,fundamentals of analysis,performance evaluation,common interaction pathways:Debye relaxation,Eddy current loss,natural resonance,size and shape factors),and the advances and performance review in microwave absorption(e.g.,absorption bandwidth,reflection loss values,absorption peak position)using various nanomaterials,such as carbon nanotubes,carbon fibers,graphenes,oxides,sulfides,phosphides,carbides,polymers and metal organic frameworks.Overall,this article not only provides an introduction on the fundamentals of microwave absorption research,but also presents a timely update on the research progress of the microwave absorption performance of various nanomaterials.

IFNγsignaling integrity in colorectal cancer immunity and immunotherapy

The majority of colorectal cancer patients are not responsive to immune checkpoint blockade(ICB).The interferon gamma(IFNγ)signaling pathway drives spontaneous and ICB-induced antitumor immunity.In this review,we summarize recent advances in the epigenetic,genetic,and functional integrity of the IFNγsignaling pathway in the colorectal cancer microenvironment and its immunological relevance in the therapeutic efficacy of and resistance to ICB.Moreover,we discuss how to target IFNγsignaling to inform novel clinical trials to treat patients with colorectal cancer.

Doped, conductive SiO_(2) nanoparticles for large microwave absorption

Although many materials have been studied for the purpose of microwave absorption,SiO_(2) has never been reported as a good candidate.In this study,we present for the first time that doped,microwave conductive SiO_(2) nanoparticles can possess an excellent microwave absorbing performance.A large microwave reflection loss(RL)of−55.09 dB can be obtained.The large microwave absorption originates mainly from electrical relaxation rather than the magnetic relaxation of the incoming microwave field.The electrical relaxation is attributed to a large electrical conductivity that is enabled by the incorporation of heterogeneous(N,C and Cl)atoms.The removal of the magnetic susceptibility only results in a negligible influence of the microwave absorption.In contrast,the removal of the heterogeneous atoms leads to a large decrease in the electrical conductivity and microwave absorption performance.Meanwhile,the microwave absorption characteristics can be largely adjusted with a change of the thickness,which provides large flexibility for various microwave absorption applications.

Microwave absorption of aluminum/hydrogen treated titanium dioxide nanoparticles

Interactions between incident electromagnetic energy and matter are of critical importance for numerous civil and military applications such as photocatalysis,solar cells,optics,radar detection,communications,information processing and transport et al.Traditional mechanisms for such interactions in the microwave frequency mainly rely on dipole rotations and magnetic domain resonance.In this study,we present the first report of the microwave absorption of Al/H2 treated TiO_(2) nanoparticles,where the A_(l)/H_(2) treatment not only induces structural and optical property changes,but also largely improves the microwave absorption performance of TiO_(2) nanoparticles.Moreover,the frequency of the microwave absorption can be finely controlled with the treatment temperature,and the absorption efficiency can reach optimal values with a careful temperature tuning.A large reflection loss of
58.02 dB has been demonstrated with 3.1mm TiO_(2) coating when the treating temperature is 700℃.The high efficiency of microwave absorption is most likely linked to the disordering-induced property changes in the materials.Along with the increased microwave absorption properties are largely increased visiblelight and IR absorptions,and enhanced electrical conductivity and reduced skin-depth,which is likely related to the interfacial defects within the TiO_(2) nanoparticles caused by the Al/H2 treatment.