95 research outputs found

    Bayesian estimation for the birth and death stochastic Markov chain.

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    In science and technology, applications of Markov chain models are varied. We consider the stochastic Markov chain by adding a stochastic term to the deterministic Markov chain. In this work, we intend the Bayesian estmation parameters of the birth and death stochastic Markov chain.&nbsp

    Economic value added of intellectual capital on the market value of listed companies in Tehran Stock Exchange

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    The present research studies the effects of the economic value added (EVA) and the intellectual capital on value of the listed companies’ value in Tehran Stock Exchange. The research was based on an applicable goal and it is descriptive and post-event in terms of nature. The sample of the research consists of 89 companies listed in Tehran Stock Exchange and the research period was from 2004 to 2011. In order to examine the research hypothesis, a multivariate regression is utilized using panel data. The results indicate spontaneous use of intellectual capital variable and the remaining profit according to the accepted principles of accounting increase description power of the market value fluctuations of the corporate remarkably

    Economic value added of intellectual capital on the market value of listed companies in Tehran Stock Exchange

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    The present research studies the effects of the economic value added (EVA) and the intellectual capital on value of the listed companies’ value in Tehran Stock Exchange. The research was based on an applicable goal and it is descriptive and post-event in terms of nature. The sample of the research consists of 89 companies listed in Tehran Stock Exchange and the research period was from 2004 to 2011. In order to examine the research hypothesis, a multivariate regression is utilized using panel data. The results indicate spontaneous use of intellectual capital variable and the remaining profit according to the accepted principles of accounting increase description power of the market value fluctuations of the corporate remarkably

    Economic value added of intellectual capital on the market value of listed companies in Tehran Stock Exchange

    Get PDF
    The present research studies the effects of the economic value added (EVA) and the intellectual capital on value of the listed companies’ value in Tehran Stock Exchange. The research was based on an applicable goal and it is descriptive and post-event in terms of nature. The sample of the research consists of 89 companies listed in Tehran Stock Exchange and the research period was from 2004 to 2011. In order to examine the research hypothesis, a multivariate regression is utilized using panel data. The results indicate spontaneous use of intellectual capital variable and the remaining profit according to the accepted principles of accounting increase description power of the market value fluctuations of the corporate remarkably

    Performance Evaluation of Bank Branches by the DEA-Tobit Model: The Case of Agricultural Bank Branches in Guilan Province

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    This paper uses data envelopment analysis (DEA) to examine the technical, pure technical, and scale efficiencies of 12 branches of the agricultural bank in Guilan province, Iran over the period of 2012-2016. The first results indicated that scale inefficiency contributed more to overall technical inefficiency than pure technical inefficiency over the studied period. Results of return to scale reveal that decreasing return to scale is the main form of scale inefficiency. Then, overall technical efficiency scores obtained from DEA was regressed over four factors determining bank efficiency (including bank size, profitability, capital adequacy, and liquidity) by the Tobit method. These four variables influenced efficiency differently. Branch size showed a negative, insignificant relationship with technical efficiency. So, it had no impact on efficiency. Profitability was the main parameter in branch efficiency following by liquidity. Profitability and liquidity influenced efficiency positively and significantly. In other words, larger and more profitable branches have higher technical efficiency

    Mitigation of radiation-induced lung pneumonitis and fibrosis using metformin and melatonin: A histopathological study

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    Background and objectives: Pneumonitis and fibrosis are the most common consequences of lung exposure to a high dose of ionizing radiation during an accidental radiological or nuclear event, and may lead to death, after some months to years. So far, some anti-inflammatory and antioxidant agents have been used for mitigation of lung injury. In the present study, we aimed to detect possible mitigatory effects of melatonin and metformin on radiation-induced pneumonitis and lung fibrosis. Materials and methods: 40 male mice were divided into 4 groups (10 mice in each). For control group, mice did not receive radiation or drugs. In group 2, mice were irradiated to chest area with 18 Gy gamma rays. In groups 3 and 4, mice were first irradiated similar to group 2. After 24 h, treatment with melatonin as well as metformin began. Mice were sacrificed after 100 days for determination of mitigation of lung pneumonitis and fibrosis by melatonin or metformin. Results: Results showed that both melatonin and metformin are able to mitigate pneumonitis and fibrosis markers such as infiltration of inflammatory cells, edema, vascular and alveolar thickening, as well as collagen deposition. Conclusion: Melatonin and metformin may have some interesting properties for mitigation of radiation pneumonitis and fibrosis after an accidental radiation event. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

    Reduction–oxidation (redox) system in radiation-induced normal tissue injury: molecular mechanisms and implications in radiation therapeutics

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    Every year, millions of cancer patients undergo radiation therapy for treating and destroying abnormal cell growths within normal cell environmental conditions. Thus, ionizing radiation can have positive therapeutic effects on cancer cells as well as post-detrimental effects on surrounding normal tissues. Previous studies in the past years have proposed that the reduction and oxidation metabolism in cells changes in response to ionizing radiation and has a key role in radiation toxicity to normal tissue. Free radicals generated from ionizing radiation result in upregulation of cyclooxygenases (COXs), nitric oxide synthase (NOSs), lipoxygenases (LOXs) as well as nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase), and their effected changes in mitochondrial functions are markedly noticeable. Each of these enzymes is diversely expressed in multiple cells, tissues and organs in a specific manner. Overproduction of reactive oxygen radicals (ROS), reactive hydroxyl radical (ROH) and reactive nitrogen radicals (RNS) in multiple cellular environments in the affected nucleus, cell membranes, cytosol and mitochondria, and other organelles, can specifically affect the sensitive and modifying enzymes of the redox system and repair proteins that play a pivotal role in both early and late effects of radiation. In recent years, ionizing radiation has been known to affect the redox functions and metabolism of NADPH oxidases (NOXs) as well as having destabilizing and detrimental effects on directly and indirectly affected cells, tissues and organs. More noteworthy, chronic free radical production may continue for years, increasing the risk of carcinogenesis and other oxidative stress-driven degenerative diseases as well as pathologies, in addition to late effect complications of organ fibrosis. Hence, knowledge about the mechanisms of chronic oxidative damage and injury in affected cells, tissues and organs following exposure to ionizing radiation may help in the development of treatment and management strategies of complications associated with radiotherapy (RT) or radiation accident victims. Thus, this medically relevant phenomenon may lead to the discovery of potential antioxidants and inhibitors with promising results in targeting and modulating the ROS/NO-sensitive enzymes in irradiated tissues and organ injury systems

    Correction to: Virotheranostics, a double-barreled viral gun pointed toward cancer; ready to shoot? (Cancer Cell International, (2020), 20, 1, (131), 10.1186/s12935-020-01219-6)

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    An amendment to this paper has been published and can be accessed via the original article. © 2020, The Author(s)

    Virotheranostics, a double-barreled viral gun pointed toward cancer; Ready to shoot?

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    Compared with conventional cancer treatments, the main advantage of oncolytic virotherapy is its tumor-selective replication followed by the destruction of malignant cells without damaging healthy cells. Accordingly, this kind of biological therapy can potentially be used as a promising approach in the field of cancer management. Given the failure of traditional monitoring strategies (such as immunohistochemical analysis (in providing sufficient safety and efficacy necessary for virotherapy and continual pharmacologic monitoring to track pharmacokinetics in real-time, the development of alternative strategies for ongoing monitoring of oncolytic treatment in a live animal model seems inevitable. Three-dimensional molecular imaging methods have recently been considered as an attractive approach to overcome the limitations of oncolytic therapy. These noninvasive visualization systems provide real-time follow-up of viral progression within the cancer tissue by the ability of engineered oncolytic viruses (OVs) to encode reporter transgenes based on recombinant technology. Human sodium/iodide symporter (hNIS) is considered as one of the most prevalent nuclear imaging reporter transgenes that provides precise information regarding the kinetics of gene expression, viral biodistribution, toxicity, and therapeutic outcomes using the accumulation of radiotracers at the site of transgene expression. Here, we provide an overview of pre-clinical and clinical applications of hNIS-based molecular imaging to evaluate virotherapy efficacy. Moreover, we describe different types of reporter genes and their potency in the clinical trials

    Targeting of inflammation for radiation protection and mitigation

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    Background: Inflammation is the response of the immune system that guards the body against several harmful stimuli in normal conditions. However, in response to ionizing radiation that leads to a massive cell death and DNA aberrations, this phenomenon causes various side effects in normal tissues. Inflammation is involved in various side effects such as gastrointestinal toxicity, mucositis, skin reactions, nervous system damage, pneumonitis, fibrosis and so on. Discussion: Observations have proposed that inflammatory mediators are involved in the toxic effect of ionizing radiation on non-irradiated cells via a phenomenon named bystander effect. Inflammation in both irradiated and non-irradiated cells can trigger genomic instability, leading to increased risk of carcinogenesis. Targeting the inflammatory mediators has been an interesting idea for improving the therapeutic ratio throughout the reduction of normal tissue injury as well as an increase in tumor response to radiotherapy. Conclusion: So far, various targets have been proposed for the amelioration of radiation toxicity in radiotherapy. Of different targets, NF-κB, COX-2, some of NADPH Oxidase subfamilies, TGF-β, p38 and the renin-angiotensin system have shown promising results. Interestingly, inhibition of these targets can help sensitize the tumor cells to the radiation treatment with some mechanisms such as suppression of angiogenesis and tumor growth as well as induction of apoptosis. In this review, we focus on recent advances on promising studies for targeting the inflammatory mediators in radiotherapy. © 2018 Bentham Science Publishers
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