Differential effects of quercetin and its two derivatives (isorhamnetin and isorhamnetin-3- glucuronide) in inhibiting proliferation of human breast cancer MCF-7 cells

Quercetin (Que) has consistently been reported to be useful cytotoxic compound in vivo and in vitro, but little is known on its metabolites. Here we examined and compared cytotoxic effect of Que and its water-soluble metabolites, isorhamnetin (IS) and isorhamnetin-3-glucuronide (I3G) in human breast cancer MCF-7 cells, and explain their tumor-inhibitory mechanism and structure-function relationship. The results showed that Que, IS and I3G could dose-dependently inhibit the growth of MCF-7 cells, and the cytotoxic effect was ranked as Que > IS > I3G. Furthermore, Que, IS and I3G mediated the cell-cycle arrest principally in S phase, followed by the decrease in the number of G0/G1 and G2/M, and 70.8%, 68.9% and 49.8% MCF-7 tumor cells entered early phase apotosis when treated with 100 µM Que, IS and I3G for 48 h, respectively. Moreover, induction of apoptosis by Que, IS and I3G were accompanied with the marginal generation of intracellular ROS. Given these results, Que, IS and I3G possess strong cytotoxic effect through a ROS-dependent apoptosis pathway in MCF-7 cells

Observation of spin-orbit magnetoresistance in metallic thin films on magnetic insulators

A magnetoresistance effect induced by the Rashba spin-orbit interaction was predicted, but not yet observed, in bilayers consisting of normal metal and ferromagnetic insulator. Here, we present an experimental observation of this new type of spin-orbit magnetoresistance (SOMR) effect in a bilayer structure Cu[Pt]/Y3Fe5O12 (YIG), where the Cu/YIG interface is decorated with nanosize Pt islands. This new MR is apparently not caused by the bulk spin-orbit interaction because of the negligible spin-orbit interaction in Cu and the discontinuity of the Pt islands. This SOMR disappears when the Pt islands are absent or located away from the Cu/YIG interface, therefore we can unambiguously ascribe it to the Rashba spin-orbit interaction at the interface enhanced by the Pt decoration. The numerical Boltzmann simulations are consistent with the experimental SOMR results in the angular dependence of magnetic field and the Cu thickness dependence. Our finding demonstrates the realization of the spin manipulation by interface engineering.Comment: 12 pages, 4 figures, 14 pages in supplementary. To appear on Science Advance

Breaking the Stream Cipher Whitenoise

Whitenoise is a stream cipher with specification given at http://eprint.iacr.org/2003/249. In this paper, we show that Whitenoise is extremely weak. It can be broken by solving about 80,000 linear equations. And only about 80,000 bytes keystream are needed in the attack

Spatially resolved Spectro-photometry of M81: Age, Metallicity and Reddening Maps

In this paper, we present a multi-color photometric study of the nearby spiral galaxy M81, using images obtained with the Beijing Astronomical Observatory 60/90 cm Schmidt Telescope in 13 intermediate-band filters from 3800 to 10000{\AA}. The observations cover the whole area of M81 with a total integration of 51 hours from February 1995 to February 1997. This provides a multi-color map of M81 in pixels of 1\arcsec.7 \times 1\arcsec.7. Using theoretical stellar population synthesis models, we demonstrate that some BATC colors and color indices can be used to disentangle the age and metallicity effect. We compare in detail the observed properties of M81 with the predictions from population synthesis models and quantify the relative chemical abundance, age and reddening distributions for different components of M81. We find that the metallicity of M81 is about $Z=0.03$ with no significant difference over the whole galaxy. In contrast, an age gradient is found between stellar populations of the central regions and of the bulge and disk regions of M81: the stellar population in its central regions is older than 8 Gyr while the disk stars are considerably younger, $\sim 2$ Gyr. We also give the reddening distribution in M81. Some dust lanes are found in the galaxy bulge region and the reddening in the outer disk is higher than that in the central regions.Comment: Accepted for publication in AJ (May 2000 issue). 27 pages including 6 figures. Uses AASTeX aasms4 styl

A New Stream Cipher HC-256

HC-256 is a software-efficient stream cipher. It generates keystream from a 256-bit secret key and a 256-bit initialization vector. The encryption speed of the C implementation of HC-256 is about 1.9 bits per clock cycle (4.2 cycle/byte) on the Intel Pentium 4 processor. A variant of HC-256 is also introduced in this paper

Cryptanalysis of a 32-bit RC4-like Stream Cipher

Nawaz, Gupta and Gong recently proposed a 32-bit RC4-like stream cipher. In this paper, we show that the keystream generated from their stream cipher is not random. The keystream can be distinguished from random with only about 100 outputs (3200 bits) in 2 milliseconds on Intel Centrino 1.6GHz processor

Funding Liquidity Shocks in a Quasi-Experiment: Evidence from the CDS Big Bang

A major change in trading conventions in April 2009, the so-called “CDS Big Bang,” induces upfront fees for trading North American CDSs. Exploiting this quasi-experiment, we provide evidence that upfront fees have a differential effect on CDS bid-ask spreads across CDS premiums. Furthermore, the funding effect is stronger for CDS contracts on smaller and riskier firms, contracts with longer maturities, and non-centrally-cleared contracts. The effect also becomes stronger after Deutsche Bank exits the CDS market. Finally, we find similar results using European CDSs. Our experimental setting offers new economic insights on the quantification and mechanism of the funding liquidity effect

Chinese merchant group culture, corporate social responsibility, and cost of debt : evidence from private listed firms in China

Chinese merchant groups are commercial organizations that have developed over thou-sands of years. Given the importance of private firms to China’s sustainable development, this study investigates the impact of the traditional Chinese concept of merchant groups on corporate social responsibility (CSR) performance and cost of debt, using Chinese private listed firms during 2008–2020. We measure merchant group culture based on the company’s geographic location. Ordi-nary least squares regression models are used to test the hypotheses. According to the results, the CSR performance of firms from five traditional Chinese merchant groups is better than non-members. A positive relationship exists between the strength of merchant group culture and CSR performance; this relationship is stronger among merchant group companies. The closer the culture to CSR values, the better the CSR performance, which is negatively related to the cost of debt. The findings are in line with the peer effect theory. Therefore, the study provides evidence that it is essential to consider the traditional Chinese merchant group culture for firms’ CSR strategies beyond formal financial and regulatory factors in China. This study is a first step in exploring the impact of merchant group culture in China on CSR performance and the economic application of this relationship