413 research outputs found
Analysis of Dynamic MRTS Traction Power Supply System Based on Dependent Train Movement Simulation
ABSTRACT As the motivation in developing modern MRTS and the upgrading of old systems in many metropolitans all over the world, especially for public transportation in developing countries, the demand to simulate the dynamic traction power supply system (TPSS) more effectively and practically has increased. This paper describes the work of simulating and analysing TPSS. It is based on dependent train movement in conjunction with TPSS simulation to establish a panorama view of the features. The free time scheduled strategy for train movement is applied which is more flexible and effective to reflect operation strategies. To set up the dynamic TPSS structure with respect to the moving train status for the system solution, the schematic arrangement is split into four parts: establishment of the elementary electric network framework; establishment of the dynamic electrical network structure which includes both the elementary power network and the moving trains statuses; dynamic electric network simulation; and system analyses based on the panoramic features drawn from the simulation. The simulation results are based on the Shanghai Metro Line One (excluding the extension section). Simulation and analysis on more lines including Shanghai Line Two and Guangzhou Line One MTRS have also been implemented using similar approaches. The complete profiles of the TPSS provide a practical means in analysing the system configuration as well as organizing the system operation
Altered cofactor regulation with disease-associated p97/VCP mutations
Dominant mutations in p97/VCP (valosin-containing protein) cause a rare multisystem degenerative disease with varied phenotypes that include inclusion body myopathy, Paget’s disease of bone, frontotemporal dementia, and amyotrophic lateral sclerosis. p97 disease mutants have altered N-domain conformations, elevated ATPase activity, and altered cofactor association. We have now discovered a previously unidentified disease-relevant functional property of p97 by identifying how the cofactors p37 and p47 regulate p97 ATPase activity. We define p37 as, to our knowledge, the first known p97-activating cofactor, which enhances the catalytic efficiency (k_(cat)/K_m) of p97 by 11-fold. Whereas both p37 and p47 decrease the K_m of ATP in p97, p37 increases the k_(cat) of p97. In contrast, regulation by p47 is biphasic, with decreased k_(cat) at low levels but increased k_(cat) at higher levels. By deleting a region of p47 that lacks homology to p37 (amino acids 69–92), we changed p47 from an inhibitory cofactor to an activating cofactor, similar to p37. Our data suggest that cofactors regulate p97 ATPase activity by binding to the N domain. Induced conformation changes affect ADP/ATP binding at the D1 domain, which in turn controls ATPase cycling. Most importantly, we found that the D2 domain of disease mutants failed to be activated by p37 or p47. Our results show that cofactors play a critical role in controlling p97 ATPase activity, and suggest that lack of cofactor-regulated communication may contribute to p97-associated disease pathogenesis
Self-Assembled 3D Flower-Like Hierarchical β-Ni(OH)2Hollow Architectures and their In Situ Thermal Conversion to NiO
Three-dimensional (3D) flower-like hierarchicalβ-Ni(OH)2hollow architectures were synthesized by a facile hydrothermal route. The as-obtained products were well characterized by XRD, SEM, TEM (HRTEM), SAED, and DSC-TGA. It was shown that the 3D flower-like hierarchicalβ-Ni(OH)2hollow architectures with a diameter of several micrometers are assembled from nanosheets with a thickness of 10–20 nm and a width of 0.5–2.5 μm. A rational mechanism of formation was proposed on the basis of a range of contrasting experiments. 3D flower-like hierarchical NiO hollow architectures with porous structure were obtained after thermal decomposition at appropriate temperatures. UV–Vis spectra reveal that the band gap of the as-synthesized NiO samples was about 3.57 eV, exhibiting obviously red shift compared with the bulk counterpart
Constraints on the unitarity triangle angle from Dalitz plot analysis of decays
The first study is presented of CP violation with an amplitude analysis of
the Dalitz plot of decays, with , and . The analysis is based on a data sample corresponding to
of collisions collected with the LHCb detector. No
significant CP violation effect is seen, and constraints are placed on the
angle of the unitarity triangle formed from elements of the
Cabibbo-Kobayashi-Maskawa quark mixing matrix. Hadronic parameters associated
with the decay are determined for the first time. These
measurements can be used to improve the sensitivity to of existing and
future studies of the decay.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-059.html;
updated to correct figure 9 (numerical results unchanged
Observation of the decay
The decay is observed in collision
data corresponding to an integrated luminosity of 3 fb recorded by the
LHCb detector at centre-of-mass energies of 7 TeV and 8 TeV. This is the first
observation of this decay channel, with a statistical significance of 15
standard deviations. The mass of the meson is measured to be
MeV/c. The branching fraction ratio
is measured to be 0.0115\,\pm\, 0.0012\, ^{+0.0005}_{-0.0009}.
In both cases, the first uncertainty is statistical and the second is
systematic. No evidence for non-resonant or decays is found.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-033.htm
Citronellal Attenuates Oxidative Stress–Induced Mitochondrial Damage through TRPM2/NHE1 Pathway and Effectively Inhibits Endothelial Dysfunction in Type 2 Diabetes Mellitus
In type 2 diabetes mellitus (T2DM), oxidative stress induces endothelial dysfunction (ED), which is closely related to the formation of atherosclerosis. However, there are few effective drugs to prevent and cure it. Citronellal (CT) is an aromatic active substance extracted from citronella plants. Recently, CT has been shown to prevent ED, but the underlying mechanism remains unclear. The purpose of this study was to investigate whether CT ameliorated T2DM-induced ED by inhibiting the TRPM2/NHE1 signal pathway. Transient receptor potential channel M2 (TRPM2) is a Ca2+-permeable cation channel activated by oxidative stress, which damages endothelial cell barrier function and further leads to ED or atherosclerosis in T2DM. The Na+/H+ exchanger 1 (NHE1), a transmembrane protein, also plays an important role in ED. Whether TRPM2 and NHE1 are involved in the mechanism of CT improving ED in T2DM still needs further study. Through the evaluations of ophthalmoscope, HE and Oil red staining, vascular function, oxidative stress level, and mitochondrial membrane potential evaluation, we observed that CT not only reduced the formation of lipid deposition but also inhibited ED and suppressed oxidative stress-induced mitochondrial damage in vasculature of T2DM rats. The expressions of NHE1 and TRPM2 was up-regulated in the carotid vessels of T2DM rats; NHE1 expression was also upregulated in endothelial cells with overexpression of TRPM2, but CT reversed the up-regulation of NHE1 in vivo and in vitro. In contrast, CT had no inhibitory effect on the expression of NHE1 in TRPM2 knockout mice. Our study show that CT suppressed the expression of NHE1 and TPRM2, alleviated oxidative stress-induced mitochondrial damage, and imposed a protective effect on ED in T2DM rats
First observation of oscillations in decays and measurement of the associated coherence parameters
Charm meson oscillations are observed in a time-dependent analysis of the
ratio of to decay
rates, using data corresponding to an integrated luminosity of recorded by the LHCb experiment. The measurements presented are
sensitive to the phase-space averaged ratio of doubly Cabibbo-suppressed to
Cabibbo-favoured amplitudes and the product of the coherence
factor and a charm mixing parameter . The
constraints measured are , which is
the most precise determination to date, and , which provides useful input for determinations
of the CP-violating phase in decays. The analysis also gives the most precise
measurement of the branching fraction, and the
first observation of oscillations in this decay mode, with a
significance of 8.2 standard deviations.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-057.htm
Management of regional citrate anticoagulation for continuous renal replacement therapy: guideline recommendations from Chinese emergency medical doctor consensus
Complete depletion of primordial germ cells in an All-female fish leads to Sex-biased gene expression alteration and sterile All-male occurrence
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