A Study on the Impact of Financial Flexibility on Corporate Value: Moderating Effects Based on Environmental Uncertainty and Agency Costs

Xiuping Li,Yeong-Gil Kim 한국무역연구원 2021 무역연구 Vol.17 No.6

Purpose The purpose of this article is to understand the financial flexibility reserves of listed companies in China. Based on the internal and external environment of China’s listed manufacturing companies, it studies the impact of financial flexibility on corporate value. Design/Methodology/Approach Based on the trade-off theory, this paper studies the impact of financial flexibility on corporate value. According to the resource-based theory, environmental uncertainty and agency cost are selected from the internal and external factors of the enterprise, and financial contingency theory and principal-agent theory are introduced to analyze their influence mechanism on the relationship between financial flexibility and enterprise value. According to the research results, corresponding suggestions are made to the government and enterprises respectively. Findings This paper studies the impact of financial flexibility on corporate value. Financial flexibility can significantly increase the corporate value of listed companies. Environmental uncertainty plays a positive role in regulating the positive impact of financial flexibility on corporate value. The moderating effect of agency costs between financial flexibility and corporate value has not been proven. Research Implications In the management of this paper, this article provides strong empirical support for the establishment of an effective financial flexibility reserve mechanism and the improvement of corporate value. At the same time, it provides an important theoretical basis for the government’s policy of “structural deleveraging to resolve financial risks” during the transition period, and also provides a reference for the steady advancement of Chinese enterprises’ deleveraging work.

Purification and Characterization of Cathepsin B from the Gut of the Sea Cucumber (Stichopus japonicas)

Li-Ming Sun,Bei-Wei Zhu,Hai-tao Wu,Lei Yu,Da-Yong Zhou,Xiuping Dong,Jing-Feng Yang,Dong-Mei Li,Wen-Xiu Ye,Yoshiyuki Murata 한국식품과학회 2011 Food Science and Biotechnology Vol.20 No.4

Cathepsin B from the gut of sea cucumber (Stichopus japonicas) was purified 81-fold with a 3%recovery by ammonium sulfate fractionation and a series chromatography on DEAE Sepharose CL-6B, Sephadex G-75, and TSK-Gel 3000 SWxl. The purified protein appeared as a single band on Native-PAGE but showed 2bands of 23 and 26 kDa on SDS-PAGE. The optimum activity was found at pH 5.5 and 45°C. The enzyme was stable at pH 4.5-6.0 and the thermal stability was up to 50oC. The enzyme was strongly inhibited by E-64, iodoacetic acid, and antipain, demonstrating it is a cysteine protease containing sulfhydryl groups. Cu^2+, Ni^2+, and Zn^2+ could strongly inhibit the enzyme activity. The amino acid sequences of the purified enzyme were acquired by mass spectrometer, which did not show any homology with previously described cathepsins, suggesting it may be a novel member.

Coronary Flow Reserve in Non-Infarcted Myocardium Predicts Long-Term Clinical Outcomes in Patients Undergoing Percutaneous Coronary Intervention

Rongchao Cheng,Xiaoming Zhu,Yunling Li,Xiuping Bai,Li Xue,Li Wei 연세대학교의과대학 2018 Yonsei medical journal Vol.59 No.2

Purpose: Coronary flow reserve (CFR) is recognized as an indicator of myocardial perfusion. The aim of this study was to assess the relationship between CFR in the non-infarcted myocardium and the incidence of major adverse cardiac events (MACEs). Materials and Methods: 100 consecutive patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention(PCI) were enrolled in the present study, and divided into MACE and non-MACE groups according to the incidence of 12-month MACEs. Left ventricular function and CFR were analyzed using two-dimensional echocardiography and myocardial contrast echocardiography at one week after PCI. Cardiac troponin I levels were assayed to estimate peak concentrations thereof. Results: The MACE group was associated with lower CFR, compared to the non-MACE group (2.41 vs. 2.77, p<0.001). In the multivariablemodel, CFR in the non-infarcted myocardium was an independent predictor of 12-month MACE (hazard ratio: 0.093, 95% confidence interval: 0.020–0.426, p=0.002) after adjustment for baseline demographic and clinical characteristics. Conclusion: CFR in the non-infarcted myocardium is a useful marker for predicting 12-month MACEs in patients with AMI undergoingprimary PCI.

Secure Performance Analysis Based on Maximum Capacity

( Xiuping Zheng ),( Meiling Li ),( Xiaoxia Yang ) 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.6

The physical security layer of industrial wireless sensor networks in the event of an eavesdropping attack has been investigated in this paper. An optimal sensor selection scheme based on the maximum channel capacity is proposed for transmission environments that experience Nakagami fading. Comparing the intercept probabilities of the traditional round robin (TRR) and optimal sensor selection schemes, the system secure performance is analyzed. Simulation results show that the change in the number of sensors and the eavesdropping ratio affect the convergence rate of the intercept probability. Additionally, the proposed optimal selection scheme has a faster convergence rate compared to the TRR scheduling scheme for the same eavesdropping ratio and number of sensors. This observation is also valid when the Nakagami channel is simplified to a Rayleigh channel.

Transparent Fluorinated Poly(imide siloxane) Copolymers with Good Adhesivity

Linshuang Li,Yong Xu,Jianfei Che,Xu Su,Chaoran Song,Xiuping Ma 한국고분자학회 2017 Macromolecular Research Vol.25 No.11

A series of fluorinated poly(imide siloxane) (PIS) copolymers were prepared with fluorine dianhydride 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and two kinds of functional diamine, 2,2'-bis(trifluoromethyl)-[ 1,1'-biphenyl]-4,4'-diamine (TFMB) and 1,3-bis(3-aminopropyl) tetramethyldisiloxane (GAPD) via a conventional two-stage process with thermal imidization. The soft and hard segments in the copolymer chain were composed of 6FDA-GAPD and 6FDA-TFMB, respectively. The structure of the resulting copolymers was determined by Fourier transform infrared (FT-IR) and 1H nuclear magnetic resonance (1H NMR) spectroscopy. Optical, adhesion, mechanical, and thermal properties of these PIS copolymers have been evaluated with respect to real siloxane loading kept to 0, 1.4, 2.6, 4.1, and 5.5wt% in the copolymers, which is lower than the theoretical content of siloxane loading due to a disproportionation reaction of the siloxane chain. The resulting PIS copolymers showed excellent optical transparency in the UV-visible range and good adhesion property. The cutoff absorption wavelength (λ0) of the resulting PIS copolymers films was less than 345 nm and the maximum transmittance (λmax) was up to 91%. The introduction of siloxane segment dramatically improved the adhesion property of PIS copolymers from 1.29 to 2.26MPa (measured by means of shear strength) compared to the fluorinated homopolyimide (6FDA-TFMB) synthesized without siloxane moiety. The thermal and mechanical properties of the resulting PIS copolymers decreased slightly with the increase in siloxane loading but still remain a good level. Due to the addition of trifluoromethyl (-CF3) group and siloxane moiety, the solubility of PIS films was greatly enhanced and they were able to be dissolved in polar aprotic solvents, such as DMAC, DMF, and NMP. The contact angle, surface energy and water absorption were also studied in order to discuss their hydrophobic property.

Compressive force regulates ephrinB2 and EphB4 in osteoblasts and osteoclasts contributing to alveolar bone resorption during experimental tooth movement

Jianhua Hou,Yanze Chen,Xiuping Meng,Ce Shi,Chen Li,Yuanping Chen,Hongchen Sun 대한치과교정학회 2014 대한치과교정학회지 Vol.44 No.6

Objective: To investigate the involvement of ephrinB2 in periodontal tissue remodeling in compression areas during orthodontic tooth movement and the effects of compressive force on EphB4 and ephrinB2 expression in osteoblasts and osteoclasts. Methods: A rat model of experimental tooth movement was established to examine the histological changes and the localization of ephrinB2 in compressed periodontal tissues during experimental tooth movement. RAW264.7 cells and ST2 cells, used as precursor cells of osteoclasts and osteoblasts, respectively, were subjected to compressive force in vitro. The gene expression of EphB4 and ephrinB2, as well as bone-associated factors including Runx2, Sp7, NFATc1, and calcitonin receptor, were examined by quantitative real-time polymerase chain reaction (PCR). Results: Histological examination of the compression areas of alveolar bone from experimental rats showed that osteoclastogenic activities were promoted while osteogenic activities were inhibited. Immunohistochemistry revealed that ephrinB2 was strongly expressed in osteoclasts in these areas. Quantitative real-time PCR showed that mRNA levels of NFATc1, calcitonin receptor, and ephrinB2 were increased significantly in compressed RAW264.7 cells, and the expression of ephrinB2, EphB4, Sp7, and Runx2 was decreased significantly in compressed ST2 cells. Conclusions: Our results indicate that compressive force can regulate EphB4 and ephrinB2 expression in osteoblasts and osteoclasts, which might contribute to alveolar bone resorption in compression areas during orthodontic tooth movement.

Cryptotanshinone inhibits TNF-α-induced LOX-1 expression by suppressing reactive oxygen species (ROS) formation in endothelial cells

Ran, Xiaoli,Zhao, Wenwen,Li, Wenping,Shi, Jingshan,Chen, Xiuping The Korean Society of Pharmacology 2016 The Korean Journal of Physiology & Pharmacology Vol.20 No.4

Cryptotanshinone (CPT) is a natural compound isolated from traditional Chinese medicine Salvia miltiorrhiza Bunge. In the present study, the regulatory effect and potential mechanisms of CPT on tumor necrosis factor alpha ($TNF-{\alpha}$) induced lectin-like receptor for oxidized low density lipoprotein (LOX-1) were investigated. Human umbilical vein endothelial cells (HUVECs) were cultured and the effect of $TNF-{\alpha}$ on LOX-1 expression at mRNA and protein levels was determined by Real-time PCR and Western blotting respectively. The formation of intracellular ROS was determined with fluorescence probe $CM-DCFH_2-DA$. The endothelial ox-LDL uptake was evaluated with DiI-ox-LDL. The effect of CPT on LOX-1 expression was also evaluated with SD rats. $TNF-{\alpha}$ induced LOX-1 expression in a dose- and time- dependent manner in endothelial cells. $TNF-{\alpha}$ induced ROS formation, phosphorylation of $NF-{\kappa}B$ p65 and ERK, and LOX-1 expression, which were suppressed by rotenone, DPI, NAC, and CPT. $NF-{\kappa}B$ inhibitor BAY11-7082 and ERK inhibitor PD98059 inhibited $TNF-{\alpha}-induced$ LOX-1 expression. CPT and NAC suppressed $TNF-{\alpha}-induced$ LOX-1 expression and phosphorylation of $NF-{\kappa}B$ p65 and ERK in rat aorta. These data suggested that $TNF-{\alpha}$ induced LOX-1 expression via ROS activated $NF-{\kappa}B/ERK$ pathway, which could be inhibited by CPT. This study provides new insights for the anti-atherosclerotic effect of CPT.

Coronary Flow Reserve in the Remote Myocardium Predicts Left Ventricular Remodeling Following Acute Myocardial Infarction

Rongchao Cheng,Xueqi Li,Guoqian Wei,Longhao Yu,Zhendong Su,Li Wei,Xiuping Bai,Jiawei Tian 연세대학교의과대학 2014 Yonsei medical journal Vol.55 No.4

Purpose: Coronary flow reserve (CFR) in the non-infarcted myocardium is often impairedfollowing acute myocardial infarction (AMI). However, the clinical significanceof CFR in the non-infarcted myocardium is not fully understood. The objective of the present study was to assess whether a relationship exists between CFR and left ventricular remodeling following AMI. Materials and Methods: We enrolled 18 consecutive patients undergoing coronary intervention. Heart function was analyzed using real-time myocardial contrast echocardiography at one week and six months aftercoronary angioplasty. Ten subjects were enrolled as the control group and were examinedusing the same method at the same time to assess CFR. Cardiac troponin I (cTnI) levels were routinely analyzed to estimate peak concentration. Results: CFR was 1.55±0.11 in the infarcted zone and 2.05±0.31 in the remote zone (p<0.01) at one week following AMI. According to CFR values in the remote zone, all patients were divided into two groups: Group I (CFR <2.05) and Group II (CFR >2.05). The levels of cTnI were higher in Group I compared to Group II on admission (36.40 vs. 21.38, p<0.05). Furthermore, left ventricular end diastolic volume was higher in Group I compared to Group II at six months following coronary angioplasty. Conclusion: Microvasculardysfunction is commonly observed in the remote myocardium. The CFR value accurately predicts adverse ventricular remodeling following AMI.

Cryptotanshinone inhibits TNF-α-induced LOX-1 expression by suppressing reactive oxygen species (ROS) formation in endothelial cells

Xiaoli Ran,Wenwen Zhao,Wenping Li,Jingshan Shi,Xiuping Chen 대한생리학회-대한약리학회 2016 The Korean Journal of Physiology & Pharmacology Vol.20 No.4

Cryptotanshinone (CPT) is a natural compound isolated from traditional Chinese medicine Salvia miltiorrhiza Bunge. In the present study, the regulatory effect and potential mechanisms of CPT on tumor necrosis factor alpha (TNF-α) induced lectin-like receptor for oxidized low density lipoprotein (LOX-1) were investigated. Human umbilical vein endothelial cells (HUVECs) were cultured and the effect of TNF-α on LOX-1 expression at mRNA and protein levels was determined by Real-time PCR and Western blotting respectively. The formation of intracellular ROS was determined with fluorescence probe CM-DCFH2-DA. The endothelial ox-LDL uptake was evaluated with DiI-ox-LDL. The effect of CPT on LOX-1 expression was also evaluated with SD rats. TNF-α induced LOX-1 expression in a dose- and time- dependent manner in endothelial cells. TNF-α induced ROS formation, phosphorylation of NF-κB p65 and ERK, and LOX-1 expression, which were suppressed by rotenone, DPI, NAC, and CPT. NF-κB inhibitor BAY11-7082 and ERK inhibitor PD98059 inhibited TNF-α-induced LOX-1 expression. CPT and NAC suppressed TNF-α-induced LOX-1 expression and phosphorylation of NF-κB p65 and ERK in rat aorta. These data suggested that TNF-α induced LOX-1 expression via ROS activated NF-κB/ERK pathway, which could be inhibited by CPT. This study provides new insights for the anti-atherosclerotic effect of CPT.