1,221 research outputs found

    Inhibition effects of paeonol on mice bearing EMT6 breast cancer through inducing rumor cell apoptosis

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    Paeonol, a phenolic component from the root bark of Paeonia moutan, has been identified to possess antitumor effects on mice bearing EMT6 breast cancer in our previous studies. However, the underlying mechanisms remain unknown. In the present study the molecular mechanisms of paeonol were further investigated in EMT6 mice model. The results showed that treatment of mice with 175 and 350 mg/kg/day of paeonol significantly inhibited the growth of the EMT6 tumor in mice, and induced tumor cell apoptosis which were demonstrated by light microscopy after hematoxylin and eosin staining and apoptosis analysis by flow cytometry. In addition, compared with the control group, paeonol increased the number of tumor cells in G0/G1 phase but decreased the number of cells in S and G2/M phase. Paeonol treatment (350 mg/kg body weight) also resulted in a decrease of Bcl-2 and an increase in Bax and caspase-3 expressions, which were demonstrated by immunohistochemical and western blot analysis. These results indicate that the antitumor effects of paeonol might be associated with arresting tumor cells in the G0/G1 phase, inducing cell apoptosis and regulation of the expression of Bcl-2, Bax and activation of caspase-3

    Antitumor effect of salidroside on mice bearing HepA hepatocellular carcinoma

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    Salidroside, a phenylpropanoid glycoside extracted from Rhodiola rosea L., has antiproliferative effects on tumour cells in mice. However it’s antitumor mechanism remains largely unknown. In this study, 4 groups of mice bearing hepatocarcinoma cells were given treatment with vehicle alone, cyclophosphamide (25 mg/kg, i.p.) and salidroside, either 100 or 200 mg/kg (p.o.) for 14 days. The morphology of tumour specimens was analysed by transmission electron microscopy. Apoptotic cells in sections of mouse tumour tissue were analysed using an in situ apoptosis kit. The expression of Bcl-2, Bax and caspase 3 mRNA were examined with RT-PCR. The results showed that the tumour weights in groups 100 or 200 mg/kg/day of salidroside were reduced significantly (45.34 and 52.48% respectively), compared to vehicle groups. Salidroside increased apoptotic cells index, e.g. in 200 mg/kg group, it was four times higher compared to the control group. Even more, treatment with salidroside decreased Bcl-2 mRNA expression and increased Bax and caspase 3 mRNA expressions. These indicated that the antitumor mechanism of salidroside may induce tumour cell apoptosis in mice by triggering the mitochondrial-dependent pathway and activation of caspase 3

    A Methodological Concept for Supporting the Commercialization of Electric Vehicles towards Sustainable Urban Freight Transport

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    Employment of Electric Commercial Vehicles (ECVs) constitutes a measure to achieve sustainable Urban Freight Transport (UFT). Despite a need for ECVs, the commercialization of ECVs in UFT has remained relatively low, which is reflected in the low market penetration. To increase the market penetration, much attention has been paid to four areas, which are the feasibility of ECVs, adaptions of logistics concepts, adaptions of vehicle concepts, and support of stakeholders. Besides studying these four areas, obtaining a satisfactory match between characteristics of ECVs and preferences of UFT is also an area for increasing the market penetration. However, due to the shortage of academic studies and appropriate tools that can systematically guide decision-makers in UFT to obtain a satisfactory match, little attention has been paid to this area. The present dissertation proposed a methodological concept, namely Sustainable ECV-UFT Matching Concept, to deal with the outlined problem. This concept comprises two methodologies (methodology of assessment and methodology of determination). Since matching up the ECVs and UFT generates many possibilities (denoted as ECV-UFT combinations), the methodology of assessment was developed to help decision-makers to assess the diverse ECV-UFT combinations quantitatively in the economic, social, and environmental perspective. Subsequently, the methodology of determination was developed to analyze the assessment results and support decision-makers in determining the satisfactory match from the many possibilities. In addition, this dissertation implemented this methodological concept by designing a simulation platform, which includes an available database and corresponding mathematical expressions. Three scenarios (DCV-, BEV-, and HEV-Express/post) were applied in the simulation platform to analyze the proposed methodological concept. The results confirmed that the Sustainable ECV-UFT Matching Concept is feasible in supporting decision-makers to determine the satisfactory match from the many ECV-UFT combinations. The benefits of obtaining a satisfactory match may inspire corresponding decision-makers to consider the employment of the appropriate ECVs in their UFT markets. This consideration may subsequently facilitate the market penetration of ECVs to achieve sustainable UFT. Overall, the main contribution of this dissertation is the development of a methodological concept to support the commercialization of ECVs for achieving sustainable UFT

    Scattering of scalar perturbations with cosmological constant in low-energy and high-energy regimes

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    We study the absorption and scattering of massless scalar waves propagating in spherically symmetric spacetimes with dynamical cosmological constant both in low-energy and high-energy zones. In the former low-energy regime, we solve analytically the Regge-Wheeler wave equation and obtain an analytic absorption probability expression which varies with MΛM\sqrt{\Lambda}, where MM is the central mass and Λ\Lambda is cosmological constant. The low-energy absorption probability, which is in the range of [0,0.986701][0, 0.986701], increases monotonically with increase in Λ\Lambda. In the latter high-energy regime, the scalar particles adopt their geometric optics limit value. The trajectory equation with effective potential emerges and the analytic high-energy greybody factor, which is relevant with the area of classically accessible regime, also increases monotonically with increase in Λ\Lambda, as long Λ\Lambda is less than or of the order of 10410^4. In this high-energy case, the null cosmological constant result reduces to the Schwarzschild value 27πrg2/427\pi r_g^2/4.Comment: 12 pages, 6 figure

    Spectrums of Black Hole in de Sitter Spacetime with Highly Damped Quasinormal Modes: High Overtone Case

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    Motivated by recent physical interpretation on quasinormal modes presented by Maggiore, the adiabatic quantity method given by Kunstatter is used to calculate the spectrums of a non-extremal Schwarzschild de Sitter black hole in this paper, as well as electrically charged case. According to highly damped Konoplya and Zhidenko's numerical observational results for high overtone modes\cite{Konoplya}, we found that the asymptotic non-flat spacetime structure leads two interesting facts as followings: (i) near inner event horizon, the area and entropy spectrums, which are given by Aen=8n1πA_{en} = 8 n_1 \pi \hbar, Sen=2πn1S_{en} = 2\pi n_1\hbar, are equally spaced accurately. (ii) However, near outer cosmological horizon the spectrums, which are in the form of Acn=16n2π48πΛAcn3Acn2A_{cn} = 16 n_2 \pi \hbar - \sqrt{\frac{48\pi}{\Lambda}A_{cn} - 3 A_{cn}^2}, Scn=4πn23πΛAcn3/16Acn2S_{cn} = 4 \pi n_2 \hbar - \sqrt{\frac{3\pi}{\Lambda}A_{cn} - 3/16 A_{cn}^2}, are not markedly equidistant. Finally, we also discuss the electrically charged case and find the black holes in de Sitter spacetime have similar quantization behavior no matter with or without charge.Comment: 12 pages, 2 firures, published versio

    Analytical method for detecting outlier evaluators

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    Epidemiologic and medical studies often rely on evaluators to obtain measurements of exposures or outcomes for study participants, and valid estimates of associations depends on the quality of data. Even though statistical methods have been proposed to adjust for measurement errors, they often rely on unverifiable assumptions and could lead to biased estimates if those assumptions are violated. Therefore, methods for detecting potential `outlier' evaluators are needed to improve data quality during data collection stage. In this paper, we propose a two-stage algorithm to detect `outlier' evaluators whose evaluation results tend to be higher or lower than their counterparts. In the first stage, evaluators' effects are obtained by fitting a regression model. In the second stage, hypothesis tests are performed to detect `outlier' evaluators, where we consider both the power of each hypothesis test and the false discovery rate (FDR) among all tests. We conduct an extensive simulation study to evaluate the proposed method, and illustrate the method by detecting potential `outlier' audiologists in the data collection stage for the Audiology Assessment Arm of the Conservation of Hearing Study, an epidemiologic study for examining risk factors of hearing loss in the Nurses' Health Study II. Our simulation study shows that our method not only can detect true `outlier' evaluators, but also is less likely to falsely reject true `normal' evaluators. Our two-stage `outlier' detection algorithm is a flexible approach that can effectively detect `outlier' evaluators, and thus data quality can be improved during data collection stage
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