Chemical graphitized r-GOs, as the thinnest and lightest material in the carbon family, exhibit high-efficiency electromagnetic interference (EMI) shielding at elevated temperature, attributed to the cooperation of dipole polarization and hopping conductivity. The r-GO composites show different temperature-dependent imaginary permittivities and EMI shielding performances with changing mass ratio.
Group A streptococci, a common human pathogen, secrete streptokinase, which activates the host's blood clot-dissolving protein, plasminogen. Streptokinase is highly specific for human plasminogen, exhibiting little or no activity against other mammalian species, including mouse. Here, a transgene expressing human plasminogen markedly increased mortality in mice infected with streptococci, and this susceptibility was dependent on bacterial streptokinase expression. Thus, streptokinase is a key pathogenicity factor and the primary determinant of host species specificity for group A streptococcal infection. In addition, local fibrin clot formation may be implicated in host defense against microbial pathogens.
Electromagnetic energy radiation is becoming a "health-killer" of living bodies, especially around industrial transformer substation and electricity pylon. Harvesting, converting, and storing waste energy for recycling are considered the ideal ways to control electromagnetic radiation. However, heat-generation and temperature-rising with performance degradation remain big problems. Herein, graphene-silica xerogel is dissected hierarchically from functions to "genes," thermally driven relaxation and charge transport, experimentally and theoretically, demonstrating a competitive synergy on energy conversion. A generic approach of "material genes sequencing" is proposed, tactfully transforming the negative effects of heat energy to superiority for switching self-powered and self-circulated electromagnetic devices, beneficial for waste energy harvesting, conversion, and storage. Graphene networks with "well-sequencing genes" (w = P /P > 0.2) can serve as nanogenerators, thermally promoting electromagnetic wave absorption by 250%, with broadened bandwidth covering the whole investigated frequency. This finding of nonionic energy conversion opens up an unexpected horizon for converting, storing, and reusing waste electromagnetic energy, providing the most promising way for governing electromagnetic pollution with self-powered and self-circulated electromagnetic devices.
Highlights d Cryo-EM structure of SARS-CoV-2 nsp12-nsp7-nsp8 core polymerase complex d The core complex of SARS-CoV-2 has lower enzymatic activity than SARS-CoV d SARS-CoV-2 nsp7-8-12 subunits are less thermostable than the SARS-CoV counterpart
Ultrathin graphene, a wonder material, exhibits great promise in various fields with its unique electronic structure and excellent physical, chemical, electrochemical, thermal and mechanical properties. Graphene presents great progress in electromagnetic interference (EMI) shielding.Herein, we review the advance in graphene-based EMI shielding materials. Towards graphene composites, we intensively evaluate EMI shielding efficiency and meaningfully describe the mechanism, such as polarization, hopping conduction and interface scattering. Moreover, we highlight an important direction for enhancing EMI shielding, the architectures, including alignment, paper, film and foam. Following that, the problems are summarized and the prospect is also highlighted for significant applications of ultrathin graphene in the field of EMI shielding.
Low‐dimensional materials have been long sought after for their particular electromagnetic (EM) functions, with promising applications in EM wave absorbing and shielding, communicating and imaging, sensing and detecting, driving and actuating, etc. Herein, across the whole EM spectrum, low‐dimensional EM functional materials and devices are highly focused on. The crystal engineering and function‐guiding features addressed relate to crystal and electronic structures, EM responses and properties, energy conversion, as well as EM wave absorbing and shielding. Moreover, insight is given into this rapidly broadening field, the main challenges are proposed and future directions are predicted.
The microwave absorption, electromagnetic interference shielding, and microwave response mechanism of graphene hybrids are highlighted, including relaxation, charge transport, magnetic resonance,etc.
Ultrathin graphene exhibits highly efficient microwave absorption at elevated temperatures, which is attributed to the cooperation of dipole polarization and hopping conductivity. The ultrathin graphene composites show different dependences on concentrations and temperature towards imaginary permittivity and microwave absorptions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.