2,665 research outputs found
Successful fault current interruption on DC circuit breaker
This study focus on the interruption capability of the DC circuit breaker employing a current commutation approach and evaluates the two main factors that determine the success rate for breaker current interruption, namely the current slope di/dt before current zero and the rate of rise of the transient recovery voltage dv/dt across the mechanical breaker contacts after current zero. A vacuum circuit breaker is used to evaluate DC breaker characteristics. Detailed mathematical and graphical analysis are presented for the proposed circuit operation used in analysing the circuit breaker properties, with simulation and experimental results at fault current levels up to 330 A
The role of the systemic inflammatory response in predicting outcomes in patients with operable cancer: Systematic review and meta-analysis
Cancer remains a leading causes of death worldwide and an elevated systemic inflammatory response (SIR) is associated with reduced survival in patients with operable cancer. This review aims to examine the evidence for the role of systemic inflammation based prognostic scores in patients with operable cancers. A wide-ranging literature review using targeted medical subject headings for human studies in English was carried out in the MEDLINE, EMBASE, and CDSR databases until the end of 2016. The SIR has independent prognostic value, across tumour types and geographical locations. In particular neutrophil lymphocyte ratio (NLR) (n = 158), platelet lymphocyte ratio (PLR) (n = 68), lymphocyte monocyte ratio (LMR) (n = 21) and Glasgow Prognostic Score/ modified Glasgow Prognostic Score (GPS/mGPS) (n = 60) were consistently validated. On meta-analysis there was a significant relationship between elevated NLR and overall survival (OS) (p < 0.00001)/ cancer specific survival (CSS) (p < 0.00001), between elevated LMR and OS (p < 0.00001)/CSS (p < 0.00001), and elevated PLR and OS (p < 0.00001)/CSS (p = 0.005). There was also a significant relationship between elevated GPS/mGPS and OS (p < 0.00001)/CSS (p < 0.00001). These results consolidate the prognostic value of the NLR, PLR, LMR and GPS/mGPS in patients with resectable cancers. This is particularly true for the NLR/GPS/mGPS which should form part of the routine preoperative and postoperative workup
What Fraction of Boron-8 Solar Neutrinos arrive at the Earth as a nu_2 mass eigenstate?
We calculate the fraction of B^8 solar neutrinos that arrive at the Earth as
a nu_2 mass eigenstate as a function of the neutrino energy. Weighting this
fraction with the B^8 neutrino energy spectrum and the energy dependence of the
cross section for the charged current interaction on deuteron with a threshold
on the kinetic energy of the recoil electrons of 5.5 MeV, we find that the
integrated weighted fraction of nu_2's to be 91 \pm 2 % at the 95% CL. This
energy weighting procedure corresponds to the charged current response of the
Sudbury Neutrino Observatory (SNO). We have used SNO's current best fit values
for the solar mass squared difference and the mixing angle, obtained by
combining the data from all solar neutrino experiments and the reactor data
from KamLAND. The uncertainty on the nu_2 fraction comes primarily from the
uncertainty on the solar delta m^2 rather than from the uncertainty on the
solar mixing angle or the Standard Solar Model. Similar results for the
Super-Kamiokande experiment are also given. We extend this analysis to three
neutrinos and discuss how to extract the modulus of the Maki-Nakagawa-Sakata
mixing matrix element U_{e2} as well as place a lower bound on the electron
number density in the solar B^8 neutrino production region.Comment: 23 pages, 8 postscript figures, latex. Dedicated to the memory of
John Bahcall who championed solar neutrinos for many lonely year
Cascaded commutation circuit for a hybrid DC breaker with dynamic control on fault current and DC breaker voltage
This paper proposed a cascaded commutation circuit based on current commutation approach for low-to-medium voltage DC fault current interruption, without snubber circuits, which slows the fault current di/dt prior to current-zero and the rate of rise of the transient recovery voltage dv/dt across the mechanical breaker contacts after current zero. The proposed dynamic control of the fault current di/dt and circuit breaker voltage dVVCB/dt increase the fault current interruption capabilityat the first and second current-zeros. Detailed mathematical equations are presented to evaluate the operational waveform profile and the validity of the cascaded commutation principle is confirmed by simulation and experimental results at 600Vdc, 110A and 330A
Autism-Associated Neuroligin-3 Mutations Commonly Impair Striatal Circuits to Boost Repetitive Behaviors
In humans, neuroligin-3 mutations are associated with autism, while in mice the corresponding mutations produce robust synaptic and behavioral changes. However, different neuroligin-3 mutations cause largely distinct phenotypes in mice, and no causal relationship links a specific synaptic dysfunction to a behavioral change. Using rotarod motor learning as a proxy for acquired repetitive behaviors in mice, we found that different neuroligin-3 mutations uniformly enhanced formation of repetitive motor routines. Surprisingly, neuroligin-3 mutations caused this phenotype not via changes in the cerebellum or dorsal striatum, but via a selective synaptic impairment in the nucleus accumbens/ventral striatum. Here, neuroligin-3 mutations increased rotarod learning by specifically impeding synaptic inhibition onto D1-dopamine receptor-expressing but not D2-dopamine receptor-expressing medium spiny neurons. Our data thus suggest that different autism-associated neuroligin-3 mutations cause a common increase in acquired repetitive behaviors by impairing a specific striatal synapse, and thereby provide a plausible circuit substrate for autism pathophysiology
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