Synthesis and anticancer activities of diquinazoline diselenides compounds

A series of novel diquinazoline diselenide compounds was designed and synthesized with substituted 4-chloroquinazoline and sodium diselenide. Their structures were confirmed by IR, 1H NMR, 13C NMR, and elemental analyses.The antitumor activity of the new compounds was evaluated by MTT method. Compound 1a, 1c, 1h and 1i were found to have activities against MDA-MB-435, A549,MDA-MB-231, SiHa, and HeLa cells. Moreover, compared with the commercial anticancer drugs Gefitinib, Oxaliplatin,Taxol, 10-Hydroxycamptothec in, and Epirubicin Hydrochloride,1a exerted better antitumor effects on corresponding cell lines at 10 μM

Machine learning method for 12^{12}C event classification and reconstruction in the active target time-projection chamber

Active target time projection chambers are important tools in low energy radioactive ion beams or gamma rays related researches. In this work, we present the application of machine learning methods to the analysis of data obtained from an active target time projection chamber. Specifically, we investigate the effectiveness of Visual Geometry Group (VGG) and the Residual neural Network (ResNet) models for event classification and reconstruction in decays from the excited $2^+_2$ state in $^{12}$C Hoyle rotation band. The results show that machine learning methods are effective in identifying $^{12}$C events from the background noise, with ResNet-34 achieving an impressive precision of 0.99 on simulation data, and the best performing event reconstruction model ResNet-18 providing an energy resolution of $\sigma_E<77$ keV and an angular reconstruction deviation of $\sigma_{\theta}<0.1$ rad. The promising results suggest that the ResNet model trained on Monte Carlo samples could be used for future classifying and predicting experimental data in active target time projection chambers related experiments.Comment: 9 pages, 10 figures, 9 table

Detection of limited-energy α particles using CR-39 in laser-induced p −11B reaction

Due to the harsh radiation environment produced by strong laser plasma, most of the detectors based on semiconductors cannot perform well. So, it is important to develop new detecting techniques with higher detection thresholds and highly charged particle resolution for investigating nuclear fusion reactions in laser-plasma environments. The Columbia Resin No. 39 (CR-39) detector is mainly sensitive to ions and insensitive to the backgrounds, such as electrons and photons. The detector has been widely used to detect charged particles in laser-plasma environments. In this work, we used a potassium–ethanol–water (PEW) etching solution to reduce the proton sensitivity of CR-39, by raising the detection threshold for the research of laser-induced 11B(p, α)2α reaction. We calibrated the 3–5 MeV α particles in an etching condition of 60°C PEW-25 solution (17% KOH + 25%C2H5OH + 58%H2O) and compared them with the manufacturer’s recommended etching conditions of 6.25 N NaOH aqueous solution at 98°C in our laser-induced nuclear reaction experiment. The results indicate, with the PEW-25 solution, that CR-39 is more suitable to distinguish α tracks from the proton background in our experiment. We also present a method to estimate the minimum detection range of α energy on specific etching conditions in our experiment

Direct and moderating effects of environmental regulation intensity on enterprise technological innovation: The case of China.

There is few significant attempt to integrate environmental regulation, government financial support, and corporate technological innovation in a methodological framework. Employing the data of the industrial enterprises with an annual turnover of over 20 million yuan from 30 Chinese provinces or municipalities between 2008 and 2016, this paper applies the fixed effect regression model to reveal the relationships between environmental regulation, government financial support, and corporate technological innovation simultaneously. Results show that: (1) there exists a U-shaped relation between environmental regulation intensity and technological innovation of enterprises which declines first and then climbs up, and China is still at the stage of inhibition before the "inflection point". (2) government financial support does not significantly work on technological innovation directly, but environmental regulation drives this effect to be achieved; when the value of lnER is higher than 3.69, government financial support can significantly facilitate corporate technological innovation. (3) the comparison between regional samples reveals that heterogeneity exists in the influence of environmental regulation intensity and government financial support on corporate technological innovation. The threshold value of enabling effects of environmental regulation in eastern region is higher than that of the central and western region. These results remain consistent after we experiment several robustness checks. Theory and policy implications of our work are discussed

News videos anchor person detection by shot clustering

key project of National Nature Science Foundation of China [61231007]; 863 Hi Tech R&D Program of China [2012AA121604]; International S & T Cooperation Program of China [2012DFG12010]In recent years, extensive research efforts have been dedicated to automatic news content analysis. In this paper, we propose a novel algorithm for anchorperson detection in news video sequences. In this method, the raw news videos are firstly split into shots by a four-threshold method, and the key frames are extracted from each shot. After that, the anchorperson detection is conducted from these key frames by using a clustering-based method based on a statistical distance of Pearson's correlation coefficient. To evaluate the effectiveness of the proposed method, we have conducted experiments on 10 news sequences. In these experiments, the proposed scheme achieves a recall of 0.96 and a precision of 0.97 for anchorperson detection. (C) 2013 Elsevier B.V. All rights reserved

p-process chaser detector in n - γ coincidences

We propose two types of neutron-γ1−γ2 triple coincidence detectors (not constructed) to chase gamma transitions to produce p-nuclei following the neutron emission in the (γ,n) reaction. Neutrons are detected with 24 3He counters embedded in a polyethylene moderator in Type I detector and with 6 liquid scintillation detectors in Type II detector, respectively. γ rays are detected with two high-purity germanium detectors and four LaBr3(Ce) detectors. The detector which is referred to as p-process chaser detector is used to search for mediating states in 180Ta through which the isomeric and ground states in 180Ta are thermalized in the p-process. A search is made for both resonant states and unresolved states in high nuclear-level-density domain.SCOPUS: ar.jinfo:eu-repo/semantics/publishe