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This paper constructs an institutional investor network based on the heavy holdings of the same stock in China and conducts a social network analysis to investigate the influence of this network on stock price volatility from the perspectives of network structure (density) and location (centrality). The study demonstrates that institutional investor network density is negatively related to stock price volatility, while network centrality is positively related to it. Mechanism analyses further reveal that network density reduces stock price volatility by mitigating private information arbitrage behavior among institutional investors, whereas network centrality increases stock price volatility by creating private information arbitrage opportunities within the network. Additionally, the paper finds that information asymmetry enhances the positive effect of network centrality on stock price volatility. These findings are generally consistent across subsample analyses for different market states, reactions to good and bad news, and types of equity ownership, as well as in other robustness tests. The practical implications of these findings are significant for market stability regulation. [ABSTRACT FROM AUTHOR]

Hypoxia induces cellular oxidative stress that is associated with neurodegenerative diseases. HPN (4'-hydroxyl-2-substituted phenyl nitronyl nitroxide), a stable nitronyl nitroxide, has excellent free radical scavenging properties. The purpose of this study was to investigate the protective effects of HPN on hypoxia-induced damage inPC12 cells. It was shown that HPN significantly attenuated hypoxia-induced loss of cell viability, release of lactate dehydrogenase (LDH), and morphological changes in PC12 cells. Moreover, hypoxic PC12 cells had increased levels of reactive oxygen species (ROS), malondialdehyde (MDA), and expression of HIF-1[alpha] and VEGF, but had reduced levels of superoxide dismutase (SOD) and catalase (CAT), and HPN reversed these changes. HPN also inhibited hypoxia-induced cell apoptosis via suppressing the expression of Bax, cytochrome c, and caspase-3, and inducing the expression of Bcl-2. These results indicate that the protective effects of HPN on hypoxia-induced damage in PC12 cells is associated with the suppression of hypoxia-induced oxidative stress and cell apoptosis. HPN could be a promising candidate for the development of a novel neuroprotective agent. Key words: nitronyl nitroxide, hypoxia, PC12 cells, oxidative stress, apoptosis. L'hypoxie provoque un stress oxydant cellulaire qui est associe aux maladies neurodegeneratives. Le 4'-hydroxyl-2-phenyl nitronyl-nitroxyde substitue (HPN), un nitronyl-nitroxyde stable, presente une excellente activite de piegeur de radicaux libres. L'objectif de cette etude consistait a examiner les effets protecteurs du HPN sur le dommage induit aux cellules PC12 par l'hypoxie. Il s'est avere que le HPN attenuait significativement la perte de viabilite cellulaire, la liberation de LDH et les changements morphologiques induits par l'hypoxie chez les cellules PC12. De plus, les cellules PC12 hypox-iques presentaient une elevation des contenus en derives reactifs de l'oxygene (DRO) et en malonaldehyde (MDA), ainsi que de l'expression de HIF-1[alpha] et du VEGF, mais une diminution de la superoxyde dismutase (SOD) et de la catalase (CAT), alors que le HPN pouvait renverser ces changements. Le HPN inhibait aussi l'apoptose induite par l'hypoxie en reprimant l'expression de Bax, du cytochrome c et de la caspase-3 et en induisant l'expression de Bcl-2. Ces resultats indiquent que la protection conferee par le HPN envers les dommages provoques par l'hypoxie chez les cellules PC12 est associee a la suppression du stress oxydant et de l'apoptose induits par l'hypoxie. Le HPN pourrait constituer un candidat prometteur dans le cadre du developpement d'un nouvel agent neuroprotecteur. [Traduit par la Redaction] Mots-cles: nitronyl-nitroxyde, hypoxie, cellules PC12, stress oxydant, apoptose., Introduction Oxygen ([O.sub.2]) is essential for aerobic organisms to produce energy (Majmundar et al. 2010). When the supply of oxygen does not meet demand from the cells, this leads to [...]

In the originally published article, a funding partner Guizhou Province Science and Technology Plan Project [Qian ke He support [2020] 4Y128] was missing from the acknowledgement. The correct statement is [...]

Objectives: To investigate the protect effect of moslosooflavone against brain injury induced by hypobaric hypoxia (HH) in mice. Methods: Protective effects of moslosooflavone in oxidative stress, neuroinflammation, energy metabolism disorder, and apoptosis were studied in HH-induced brain damage mice. The pathological morphology in the cortex of mice was determined by hematoxylin and eosin staining. The related protein expressions were detected by western blot. Key findings: Moslosooflavone improved HH-induced brain histopathological changes, reduced the contents of ROS and MDA, and elevated the levels of antioxidant enzymes and GSH in HH-exposed brains of mice. Moslosooflavone also markedly enhanced the ATPase activities and PK, ATP contents, while reducing LDH activity and the LD, TNF-α, IL-1β, and IL-6 contents HH-exposed brains of mice. In addition, moslosooflavone notably decreased the expression of HIF-1α, VEGF, Bax, and cleaved caspase-3 dramatically increasing the expression of Bcl-2, Nrf2, and HO‑1 in HH-exposed brains of mice. Conclusions: Our current studies indicate that moslosooflavone protects HH-induced brain injury possibly through alleviating oxidative stress and neuroinflammation, maintaining the balance of energy metabolism, and inhibiting cell apoptosis. [ABSTRACT FROM AUTHOR]

A pipeline system made of catheters is used for liquid–gas transportation in aero-engines. It is important to measure the residual stresses, such as the assembly stress in this system, as they influence performance and lifetime. Compared to other testing techniques, ultrasonic measurement methods based on acoustic-elastic effects can better solve problems. For the above requirements, this paper researches an aero-engine thin-wall catheter's assembly stress measurement method based on ultrasonic guided waves's acoustic, elastic effect. The propagation and dispersion characteristics of guided ultrasonic waves in the catheter were studied. Then, the excitation frequency, guided wave mode, and single-mode excitation mode of the simulation model were determined. Next, a finite element simulation model was established for simulation experiments. In order to reduce the influence of sampling rate and working environment noise on the measurement accuracy of assembly stress, the ultrasonic guided wave signal was processed by the wavelet threshold method. A good noise reduction effect was obtained by determining the wavelet base and the number of decomposition layers. Finally, an experimental platform was built to measure the assembly stress of thin-walled catheters. The maximum measurement error of the assembly stress of a thin-walled catheter was 21.1 MPa, which verified the feasibility of the measurement method. This study provides a promising method for accurately measuring the assembly stress of thin-walled catheters in aero-engines. [ABSTRACT FROM AUTHOR]