770 research outputs found
Disease tolerance: a protective mechanism of lung infections
Resistance and tolerance are two important strategies employed by the host immune response to defend against pathogens. Multidrug-resistant bacteria affect the resistance mechanisms involved in pathogen clearance. Disease tolerance, defined as the ability to reduce the negative impact of infection on the host, might be a new research direction for the treatment of infections. The lungs are highly susceptible to infections and thus are important for understanding host tolerance and its precise mechanisms. This review focuses on the factors that induce lung disease tolerance, cell and molecular mechanisms involved in tissue damage control, and the relationship between disease tolerance and sepsis immunoparalysis. Understanding the exact mechanism of lung disease tolerance could allow better assessment of the immune status of patients and provide new ideas for the treatment of infections
Development of a Vacuum Ultra-Violet Laser-Based Angle-Resolved Photoemission System with a Super-High Energy Resolution Better Than 1 meV
The design and performance of the first vacuum ultra-violet (VUV) laser-based
angle-resolved photoemission (ARPES) system are described. The VUV laser with a
photon energy of 6.994 eV and bandwidth of 0.26 meV is achieved from the second
harmonic generation using a novel non-linear optical crystal KBe2BO3F2 (KBBF).
The new VUV laser-based ARPES system exhibits superior performance, including
super-high energy resolution better than 1 meV, high momentum resolution,
super-high photon flux and much enhanced bulk sensitivity, which are
demonstrated from measurements on a typical Bi2Sr2CaCu2O8 high temperature
superconductor. Issues and further development related to the VUV laser-based
photoemission technique are discussed.Comment: 29 pages, 10 figures, submitted to Review of Scientific Instrument
Overview of Grounding Schemes for Solid-State Transformers in Distribution Networks
Proposed to be the critical enabling component for future distribution networks, solid-state transformers (SSTs) have drawn much attention lately. They have a massive potential to help reduce size and weight, improve efficiency, integrate microgrids, renewables and energy storages in distribution systems, and can fulfil multiple grid functions such as bidirectional power flow control, fault isolation, system reconfiguration, and post-fault restoration. The introduction of these power electronics devices in distribution systems, however, also brings new challenges to the grid. Extra levels of electromagnetic interference, stray current, and personnel safety are among the most prominent practical issues that proper grounding arrangements can address. In this paper, considerations that should be factored into the grounding scheme design for SST ports with different voltage forms and levels are thoroughly reviewed and summarised. The characteristics of various grounding schemes used in AC and DC distribution systems are evaluated and compared in detail from different perspectives. Based on the comprehensive review, several combinations of grounding schemes are recommended for typical SSTs. In addition, the inclusion of new relay protection devices in the SST grounding scheme design, considering their characteristics and unique requirements, to enhance protection and reliability is also discussed
- …