Quercetin promotes MC3T3-E1 cell growth via PI3K/Akt signaling pathway

Purpose: To investigate the effect of quercetin on mouse osteoblast MC3T3-E1 cell growth and the molecular mechanisms involved.Methods: The effect of quercetin on MC3T3-E1 cells growth, cell cycle distribution, bone-related genes and PI3K/Akt signaling pathway were determined in vitro using MTT assay, flow cytometry, qPCR and western blot, respectively.Results: Qercetin promoted MC3T3-E1 cell growth, as revealed from MTT assay. Flow cytometryshowed that quercetin administration resulted in accumulation of cells in the S phase. In addition, quercetin up-regulated mRNA expression levels of osteopontin, ALP, osteoprotegerin, osteocalcin and RunX-2, and increased phosphorylation of AKT.Conclusion: Quercetin enhances the growth of MC3T3-E1 cells via a mechanism involving accumulation of cells in S phase, increasing mRNA expression levels of bone-associated genes, and increasing the phosphorylation of AKT.Keywords: Quercetin, MC3T3-E1 cells, AKT phosphorylation, Osteopontin, Osteoprotegerin, Osteocalcin, RunX-

An equivalent expression of Z2 Topological Invariant for band insulators using Non-Abelian Berry's connection

We introduce a new expression for the Z2 topological invariant of band insulators using non- Abelian Berry's connection. Our expression can identify the topological nature of a general band insulator without any of the gauge fixing problems that plague the concrete implementation of previous invariants. The new expression can be derived from the "partner switching" of the Wannier function center during time reversal pumping and is thus equivalent to the Z2 topological invariant proposed by Kane and Mele.Comment: 14 pages, 8 figure

A Robust Quantum Random Access Memory

A "bucket brigade" architecture for a quantum random memory of $N=2^n$ memory cells needs $n(n+5)/2$ times of quantum manipulation on control circuit nodes per memory call. Here we propose a scheme, in which only average $n/2$ times manipulation is required to accomplish a memory call. This scheme may significantly decrease the time spent on a memory call and the average overall error rate per memory call. A physical implementation scheme for storing an arbitrary state in a selected memory cell followed by reading it out is discussed.Comment: 5 pages, 3 figure

Detection of gamma-ray emission from the Coma cluster with Fermi Large Area Telescope and tentative evidence for an extended spatial structure

Many galaxy clusters have giant halos of non-thermal radio emission, indicating the presence of relativistic electrons in the clusters. Relativistic protons may also be accelerated by merger and/or accretion shocks in galaxy clusters. These cosmic-ray (CR) electrons and/or protons are expected to produce gamma-rays through inverse-Compton scatterings or inelastic $pp$ collisions respectively. Despite of intense efforts in searching for high-energy gamma-ray emission from galaxy clusters, conclusive evidence is still missing so far. Here we report the discovery of $\ge 200$ MeV gamma-ray emission from the Coma cluster direction with an unbinned likelihood analysis of the 9 years of {\it Fermi}-LAT Pass 8 data. The gamma-ray emission shows a spatial morphology roughly coincident with the giant radio halo, with an apparent excess at the southwest of the cluster. Using the test statistic analysis, we further find tentative evidence that the gamma-ray emission at the Coma center is spatially extended. The extended component has an integral energy flux of $\sim 2\times 10^{-12}{\rm \ erg\ cm^{-2}\ s^{-1}}$ in the energy range of 0.2 - 300 GeV and the spectrum is soft with a photon index of $\simeq-2.7$. Interpreting the gamma-ray emission as arising from CR proton interaction, we find that the volume-averaged value of the CR to thermal pressure ratio in the Coma cluster is about $\sim 2\%$. Our results show that galaxy clusters are likely a new type of GeV gamma-ray sources, and they are probably also giant reservoirs of CR protons.Comment: 10 pages, 10 figures, Accepted by Physical Review D, more spatial models for the gamma-ray emission are used, systematic checks on the results are adde

Neuroprotective effect of whole-plant extract of Torilis leptophylla in isoflurane-treated rats

Purpose: To investigate the neuroprotective effect of Torilis leptophylla (TL) extract on animals exposed to isoflurane-induced anesthesia.Methods: General anesthesia was induced in diabetic rats by administration of 2 % sevoflurane (v/v) in 100 % oxygen. The animals from the treatment group were orally administered TL extract. Behavioral parameters, the explicit objection recognition index, and performance in water maze experiments were observed. Additionally, the neuroprotection provided by the herbal extract was measured in terms of the reduction in oxidative stress in isolated animal brain tissue.Results: The study showed approximately 1.5-fold improvement in object recognition index of TL extract- treated anesthetized rats compared with the control group of anesthetized animals. Additionally, the escape latency values of the anesthetized rats in Morris water maze experiments were reduced following TL extract treatment at all time points throughout the 5-day study protocol. Finally, biomarkers of oxidative stress in the brain indicate that the levels of superoxide dismutase and catalase enzymes were improved by approximately 1.43- and 1.36-fold in TL-extract-treated rats compared with those in the control group.Conclusion: The results of the present study show that cognitive dysfunction and brain injury associated with enhanced oxidative stress can be reversed by the antioxidant properties of the TL extract.Keywords: Anesthesia, Torilis leptophylla, Neuroprotection, Brain injury, Cognitive impairment, Isofluran

Exploring Consumers’ Coping Behaviors in Online Double Deviation Scenarios: From Power Perspective

Service recovery is a critical moment of truth in retaining customers and reinforcing customer relationships, and has been considered as an “Achilles\u27 heel” in online marketplaces. Poor service recoveries exacerbate the negative effects of the failure, producing a “double deviation” effect. The double deviation effect may arise from the seller’s power misuse and then dissolve the buyer-seller relationship (e.g., violate consumer psychological contract), elicit consumer negative emotions which lead to customer coping behaviors. This study links the theories of psychological contract violation (PCV), emotion, and coping from the power perspective to investigate the double deviation scenario in online auction marketplaces. Two moderators (perceived power and perceived consumer empowerment) are considered in our proposed model. Data collected from 181 consumers of one auction website provide support for the proposed model. The results shed light on what constitutes the determinants of consumer judgments while facing double deviation scenario and how consumers react to and cope with it in online marketplaces. Implications and limitations are discussed