197 research outputs found

    Why and How Chinese Non-Financial Firms Hedge? An Empirical Study on the Determinants and Effects of Corporate Hedging

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    With the internationalisation of RMB and the acceleration of the opening of Chinese financial market, Chinese companies face more foreign exchange exposure and default risk, which require more effectively risk management strategy. Given the significant role of derivative instruments in mitigating risks, this research investigates why and how Chinese firms hedge by employing a unique hand-collected dataset which includes a sample of 501 Chinese mainland and Hong Kong non-financial firms listed in Hong Kong Stock Exchange from 2008 to 2016. To answer the question of how Chinese companies hedge, this study firstly summarises the statistics of sample Chinese firms’ hedging activities. Then, the association between the likelihood of hedging and firm’s characteristics is estimated by univariate and multivariate logit analysis. Afterwards, this dissertation studies the role hedging with derivatives plays in Chinese companies’ risks and values. The main findings of this research are as follows. Firstly, the results suggest that the most popular derivatives in China is foreign exchange derivatives. Apart from using financial derivative instruments to manage financial risks, both Hong Kong and Chinese mainland corporations also use foreign debt as natural hedging. Secondly, larger Chinese companies and enterprises with more foreign exchange exposures are more willing to hedge than other firms. Firms with high profitability might tend to hedge as well. Thirdly, hedging strategy reduces firm’s equity risk and the likelihood of default. And it slightly increases the value measured by Tobin’s Q without improving the profitability. This contrary effect of hedging on firm’s value and profitability might indicate that hedging improves the value of firms by reducing risks, not by improving the financial performance. Overall, Chinese firms may adopt derivatives mainly for hedging not for speculative purposes

    Sorafenib modulates the radio sensitivity of hepatocellular carcinoma cells in vitro in a schedule-dependent manner

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    BACKGROUND: Hepatocellular carcinoma (HCC) has a high incidence and mortality. Radiotherapy and sorafenib have proven effective for HCC. Here, we investigated whether sorafenib modulated the response of HCC cells to irradiation in vitro, effect of timing of sorafenib, and the underlying mechanisms. METHODS: Cell viability of the HCC cell lines, SMMC-7721 and Bel-7402, was examined by the 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenyl)-2(4-sulfophenyl)-2 H-terazolium (MTT) assays. Clonogenic growth assays of SMMC-7721 and Bel-7402 were determined by colony formation assays. DNA damage was assessed by monitoring γ-HAX foci in irradiated cells with immunofluorescence microscopy, and cell cycle distribution changes were examined by flow cytometry. Effects of sorafenib (15 μM) added 30 min prior to radiation (pre-irradiation sorafenib) of SMMC-7721 and BEL-7402 or 24 h post-irradiation (post-irradiation sorafenib) on irradiated SMMC-7721 and BEL-7402 cells were compared to those of radiation alone or no treatment. RESULTS: The effect of sorafenib was dependent on its time of addition in relationship to irradiation of cells. Pre-irradiation sorafenib did not significantly affect the viability of SMMC-7221 and BEL-7402 cells compared with irradiation treatment alone. In contrast, post-irradiation sorafenib increased the sensitivity of irradiated SMMC-7221 and BEL-7402 cells significantly in a time-dependent manner. Pre-irradiation sorafenib significantly increased the surviving fraction of SMMC-7221 and BEL-7402 cells in clonogenic assays whereas post-irradiation sorafenib significantly reduced the surviving fractions of SMMC-7221 and BEL-7402 cells. SMMC-7721 cells treated with sorafenib 30 min before irradiation had significantly fewer cells with γ-H2AX foci (23.8 ± 2.9%) than SMMC-7721 cells receiving radiation alone (59.9 ± 2.4; P < 0.001). Similarly, BEL-7402 cells receiving sorafenib prior to irradiation had significantly fewer cells with γ-H2AX foci (46.4 ± 3.8%) than those receiving radiation alone (25.0 ± 3.0%; P < 0.001). In addition, irradiation (6 Gy) caused a significant increase in the percentage of both SMMC-7721 and BEL-7402 cells in G2/M at 12 to 16 h post irradiation, which was markedly delayed by pre-irradiation sorafenib. CONCLUSIONS: Sorafenib combined with irradiation exerted a schedule-dependent effect in HCC cells in vitro, which has significant implications for the combined use of sorafenib and radiotherapy for HCC patients

    eIF2α signaling regulates autophagy of osteoblasts and the development of osteoclasts in OVX mice

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    Bone loss in postmenopausal osteoporosis is induced chiefly by an imbalance of bone-forming osteoblasts and bone-resorbing osteoclasts. Salubrinal is a synthetic compound that inhibits de-phosphorylation of eukaryotic translation initiation factor 2 alpha (eIF2α). Phosphorylation of eIF2α alleviates endoplasmic reticulum (ER) stress, which may activate autophagy. We hypothesized that eIF2α signaling regulates bone homeostasis by promoting autophagy in osteoblasts and inhibiting osteoclast development. To test the hypothesis, we employed salubrinal to elevate the phosphorylation of eIF2α in an ovariectomized (OVX) mouse model and cell cultures. In the OVX model, salubrinal prevented abnormal expansion of rough ER and decreased the number of acidic vesiculars. It regulated ER stress-associated signaling molecules such as Bip, p-eIF2α, ATF4 and CHOP, and promoted autophagy of osteoblasts via regulation of eIF2α, Atg7, LC3, and p62. Salubrinal markedly alleviated OVX-induced symptoms such as reduction of bone mineral density and bone volume fraction. In primary bone-marrow-derived cells, salubrinal increased the differentiation of osteoblasts, and decreased the formation of osteoclasts by inhibiting nuclear factor of activated T-cells cytoplasmic 1 (NFATc1). Live cell imaging and RNA interference demonstrated that suppression of osteoclastogenesis is in part mediated by Rac1 GTPase. Collectively, this study demonstrates that ER stress-autophagy axis plays an important role in OVX mice. Bone-forming osteoblasts are restored by maintaining phosphorylation of eIF2α, and bone-resorbing osteoclasts are regulated by inhibiting NFATc1 and Rac1 GTPase

    Measurement of Interphase Forces based on Dual-modality ERT/DP Sensor in Horizontal Two-phase Flow Gas-water

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    In order to better understand the mechanisms of two-phase flow and the prevailing flow regimes in horizontal pipelines, the evaluation of interphase forces is paramount. This study develops a method to quantitatively estimate the interphase force in two-phase gas-water flow in horizontal pipeline. The electrical resistance tomography technology is used to measure the void fraction, while the differential pressure perpendicular to the horizontal pipe is measured in different flow patterns via a Differential Pressure sensor. The inner pipe diameter is 50 mm, the water flow range from 3.26 m3/h to 7.36 m3/h, the gas flowrate range from 1 to 60 l/min, which covered a range of flow patterns, the absolute pressure range from0.07 MPa to 0.12 MPa. The relationship between the differential pressure drop and interphase force is established, and the effects of these forces on the flow are analyzed. Experimental results indicate that the dual-modality measurement system was successfully provided a quantitative evaluation of inter-phase forces in two-phase horizontal gas-water flow

    Comparative studies of the anti-thrombotic effects of saffron and HongHua based on network pharmacology

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    Purpose: To investigate the comparative anti-thrombotic effects of saffron and Honghua, and also to explore possible mechanisms in thrombosis based on network pharmacology. Methods: A network pharmacology model was used for bioactive components, targets and pathways for saffron and HongHua via Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), PharmMapper, Genecard, Uniprot and KEGG databases. In animal experiments, 72 rats were randomly divided into 9 groups: normal control group (NC), model control group (MC), crocetin groups (80, 40, 20 mg/kg), hydroxysafflor yellow A(HSYA) groups (80, 40, 20 mg/kg), and aspirin group (40 mg/kg). Using in vitro thrombosis models and an acute blood stasis model in vivo, the anti-thrombotic effects of these treatments on clotting time, hemorheology parameters, Thromboxane B2 (TXB2), plasmin activator inhibitor (PAI), protein C (PC), protein S (PS), and thrombinantithrombin complex (TAT) were determined and comparisons made for saffron and HongHua. Results: Five potential compounds, 16 anti-thrombotic targets and 27 pathways were predicted for saffron, while 22 compounds, 37 disease targets and 35 pathways were found for HongHua (p &lt; 0.05). Pharmacological experiments revealed that crocetin and HSYA had significant effects on thrombus length, thrombus wet/dry mass, whole blood viscosity (WBV), erythrocyte aggregation index (EAI), clotting time and D-dimer for the high and middle groups. Unlike HSYA, crocetin also had significant and dose-dependent effects on PAI, prothrombin fragment 1+2 (F1+2) and PS and had highly significant effects on TXB2 and TAT. Conclusion: This research provides a systematic, comprehensive and comparative analysis of component, target and anti-thrombotic pathways of saffron and HongHua based on network pharmacology, and also shows that saffron has more significant anti-thrombotic effect than HongHua. Keywords: Saffron; HongHua; Network pharmacology; Anti-thrombosis; Network mode
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