539 research outputs found
Performance-based plastic design of self-centering steel braced frame
This study proposes a performance-based seismic design (PBSD) method for steel braced frames with novel self-centering (SC) braces that utilizes shape memory alloys (SMA) as a kernel component. The presented PBSD method is essentially a modified version of the performance-based plastic design. A few concentrically braced frames with SC braces are designed as examples to illustrate the efficacy of the proposed design method. The seismic performance of the designed frames is examined at various seismic intensity levels. Results of nonlinear time-history analyses indicate that the designed SC braced frames can successfully achieve the prescribed performance objectives at three seismic hazard levels
Coevolution of synchronous activity and connectivity in coupled chaotic oscillators
We investigate the coevolution dynamics of node activities and coupling strengths in coupled chaotic oscillators via a simple threshold adaptive scheme. The coupling strength is synchronous activity regulated, which in turn is able to boost the synchronization remarkably. In the case of weak coupling, the globally coupled oscillators present a highly clustered functional connectivity with a power-law distribution in the tail with γ≃3.1, while for strong coupling, they self-organize into a network with a heterogeneously rich connectivity at the onset of synchronization but exhibit rather sparse structure to maintain the synchronization in noisy environment. The relevance of the results is briefly discussed
A scalable tripartite Wigner's friend scenario
Wigner's friend thought experiment is intended to reveal the inherent tension
between unitary evolution and measurement collapse. On the basis of Wigner's
friend experiment, Brukner derives a no-go theorem for observer-independent
facts. We construct an extended Wigner's friend scenario including three
laboratories, namely, Alice's laboratory, Bob's laboratory and Charlie's
laboratory, where Alice, Bob and Charlie are standing outside the laboratories
while their friends are placed inside their own laboratories. We consider
quantum simulation via Q\# quantum programming and also realize the primary
quantum circuits using IBM quantum computers. Then, we calculate the
probabilities and corresponding statistical uncertainties. It has been shown
that the results of quantum simulation are clearly consistent with theoretical
values, while it has a slightly higher error rates for the experimental results
of quantum computers mainly because of a series of quantum gates, especially
CNOT gates.Comment: 8 pages, 8 figure
Alpha Lipoic Acid Modulated High Glucose-Induced Rat Mesangial Cell Dysfunction via mTOR/p70S6K/4E-BP1 Pathway
The aim of this study was to investigate whether alpha lipoic acid (LA) regulates high glucose-induced mesangial cell proliferation and extracellular matrix production via mTOR/p70S6K/4E-BP1 signaling. The effect of LA on high glucose-induced cell proliferation, fibronectin (FN), and collagen type I (collagen-I) expression and its mechanisms were examined in cultured rat mesangial cells by methylthiazol tetrazolium (MTT) assay, flow cytometry, ELISA assay, and western blot, respectively. LA at a relatively low concentration (0.25 mmol/L) acted as a growth factor in rat mesangial cells, promoted entry of cell cycle into S phase, extracellular matrix formation, and phosphorylated AKT, mTOR, p70S6K, and 4E-BP1. These effects disappeared when AKT expression was downregulated with PI3K/AKT inhibitor LY294002. Conversely, LA at a higher concentration (1.0 mmol/L) inhibited high glucose-induced rat mesangial cell proliferation, entry of cell cycle into S phase, and extracellular matrix exertion, as well as phosphorylation of mTOR, p70S6K, and 4E-BP1 but enhanced the activity of AMPK. However, these effects disappeared when AMPK activity was inhibited with CaMKK inhibitor STO-609. These results suggest that LA dose-dependently regulates mesangial cell proliferation and matrix protein secretion by mTOR/p70S6K/4E-BP1 signaling pathway under high glucose conditions
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