57 research outputs found
Critical current density and vortex pinning in tetragonal FeSSe ()
We report critical current density () in tetragonal FeS single crystals,
similar to iron based superconductors with much higher superconducting critical
temperatures ('s). The is enhanced 3 times by 6\% Se doping. We
observe scaling of the normalized vortex pinning force as a function of reduced
field at all temperatures. Vortex pinning in FeS and FeSSe
shows contribution of core-normal surface-like pinning. Reduced temperature
dependence of indicates that dominant interaction of vortex cores and
pinning centers is via scattering of charge carriers with reduced mean free
path (), in contrast to KFeSe where spatial
variations in () prevails.Comment: 5 pages, 4 figure
Enhanced Oxidative Stress Is Responsible for TRPV4-Induced Neurotoxicity
Transient receptor potential vanilloid 4 (TRPV4) has been reported to be responsible for neuronal injury in pathological conditions. Excessive oxidative stress can lead to neuronal damage, and activation of TRPV4 increases the production of reactive oxygen species and nitric oxide (NO) in many types of cells. The present study explored whether TRPV4-induced neuronal injury is mediated through enhancing oxidative stress. We found that intracerebroventricular injection of the TRPV4 agonist GSK1016790A increased the content of methane dicarboxylic aldehyde (MDA) and NO in the hippocampus, which was blocked by administration of the TRPV4 specific antagonist HC-067047. The activities of catalase (CAT) and glutathione peroxidase (GSH-Px) were decreased by GSK1016790A, whereas the activity of superoxide dismutase remained unchanged. Moreover, the protein level and activity of neuronal nitric oxide synthase (nNOS) were increased by GSK1016790A, and the GSK1016790A-induced increase in NO content was blocked by an nNOS specific antagonist ARL-17477. The GSK1016790A-induced modulations of CAT, GSH-Px and nNOS activities and the protein level of nNOS were significantly inhibited by HC-067047. Finally, GSK1016790A-induced neuronal death and apoptosis in the hippocampal CA1 area were markedly attenuated by administration of a reactive oxygen species scavenger Trolox or ARL-17477. We conclude that activation of TRPV4 enhances oxidative stress by inhibiting CAT and GSH-Px and increasing nNOS, which is responsible, at least in part, for TRPV4-induced neurotoxicity
Health Monitoring for Coated Steel Belts in an Elevator System
This paper presents a method of health monitoring for coated steel belts in an elevator system by measuring the electrical resistance of the ropes embedded in the belt. A model on resistance change caused by fretting wear and stress fatigue has been established. Temperature and reciprocating cycles are also taken into consideration when determining the potential strength degradation of the belts. It is proved by experiments that the method could effectively estimate the health degradation of the most dangerous section as well as other ones along the whole belts
A Mott insulator continuously connected to iron pnictide superconductors
Iron-based superconductivity develops near an antiferromagnetic order and out
of a bad metal normal state, which has been interpreted as originating from a
proximate Mott transition. Whether an actual Mott insulator can be realized in
the phase diagram of the iron pnictides remains an open question. Here we use
transport, transmission electron microscopy, X-ray absorption spectroscopy, and
neutron scattering to demonstrate that NaFeCuAs near
exhibits real space Fe and Cu ordering, and are antiferromagnetic insulators
with the insulating behavior persisting above the N\'eel temperature,
indicative of a Mott insulator. Upon decreasing from , the
antiferromagnetic ordered moment continuously decreases, yielding to
superconductivity around . Our discovery of a Mott insulating state in
NaFeCuAs thus makes it the only known Fe-based material in which
superconductivity can be smoothly connected to the Mott insulating state,
highlighting the important role of electron correlations in the high- superconductivity.Comment: in press, Nat. Commun., 4 figures, supplementary information
available upon reques
Improving the Efficacy of Conventional Therapy by Adding Andrographolide Sulfonate in the Treatment of Severe Hand, Foot, and Mouth Disease: A Randomized Controlled Trial
Background. Herb-derived compound andrographolide sulfonate (called Xiyanping injection) recommended control measure for severe hand, foot, and mouth disease (HFMD) by the Ministry of Health (China) during the 2010 epidemic. However, there is a lack of good quality evidence directly comparing the efficacy of Andrographolide Sulfonate combination therapy with conventional therapy. Methods. 230 patients were randomly assigned to 7–10 days of Andrographolide Sulfonate 5–10 mg/Kg/day and conventional therapy, or conventional therapy alone. Results. The major complications occurred less often after Andrographolide Sulfonate (2.6% versus 12.1%; risk difference [RD], 0.94; 95% CI, 0.28–1.61; P=0.006). Median fever clearance times were 96 hours (CI, 80 to 126) for conventional therapy recipients and 48 hours (CI, 36 to 54) for Andrographolide Sulfonate combination-treated patients (χ2=16.57, P<0.001). The two groups did not differ in terms of HFMD-cause mortality (P=1.00) and duration of hospitalization (P=0.70). There was one death in conventional therapy group. No important adverse event was found in Andrographolide Sulfonate combination therapy group. Conclusions. The addition of Andrographolide Sulfonate to conventional therapy reduced the occurrence of major complications, fever clearance time, and the healing time of typical skin or oral mucosa lesions in children with severe HFMD
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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