Non-uniform wind environment in mountainous terrain and aerostatic stability of a bridge

Xingyu Chen,Junjie Guo,Haojun Tang,Yongle Li,Lei Wang 한국풍공학회 2020 Wind and Structures, An International Journal (WAS Vol.30 No.6

The existence of a dam has potential effects on the surrounding wind environment especially when it is located in mountainous areas. In this situation, the long-span bridge over the reservoir can easily be exposed to non-uniform incoming flows, affecting its wind-resistance performance. This paper presents a study on the aerostatic stability of such a bridge. Wind tunnel tests were first carried out to investigate the wind environment above a mountainous reservoir. The results show that the angle of attack and the wind speed along the bridge axis show obvious non-uniform characteristics, which is related to the inflow direction. When winds come from the south where the river is winding, the angle of attack varies along the span direction significantly. The finite element model for the bridge was established using ANSYS software, and effects of non-uniform wind loads on the aerostatic stability were computed. Non-uniform angle of attack and wind speed are unfavorable to the aerostatic stability of the bridge, especially the former. When the combined action of non-uniform angle of attack and wind speed is considered, the critical wind speed of aerostatic instability is further reduced. Moreover, the aerostatic stability of the bridge is closely related to the dam height.

Grem1 accelerates nucleus pulposus cell apoptosis and intervertebral disc degeneration by inhibiting TGF-β-mediated Smad2/3 phosphorylation

Chen Shunlun,Lei Linchuan,Li Zemin,Chen Fan,Huang Yuming,Jiang Guowei,Guo Xingyu,Zhao Zhuoyang,Liu Hui,Wang Hua,Liu Caijun,Zheng Zhaomin,Wang Jianru 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Intervertebral disc degeneration (IVDD) is a main cause of low back pain, and inflammatory factors play key roles in its pathogenesis. Gremlin-1 (Grem1) was reported to induce an inflammatory response in other fields. This study aimed to investigate the mechanisms of Grem1 in the degenerative process of intervertebral discs. Dysregulated genes were determined by analyzing microarray profiles. The expression of Grem1 in 17 human disc samples (male:female = 9:8) and rat models (n = 5 each group) was measured by western blotting (WB), real-time quantitative PCR (RT-qPCR), and immunohistochemistry (IHC). The regulatory effects of Grem1 on apoptosis were examined using siRNAs, flow cytometry, immunofluorescence (IF), and WB. The therapeutic effect was evaluated by locally injecting specific Grem1 siRNA into IVDD rats. The expression of Grem1 was significantly increased in human degenerative intervertebral discs; furthermore, the expression of Grem1 positively correlated with the level of intervertebral disc degeneration. Grem1 was significantly overexpressed in tumor necrosis factor (TNF)-α-induced degenerative NP cells. Apoptosis in degenerative NP cells transfected with siRNA targeting Grem1 was significantly lower than that in the control group. Specific Grem1 siRNA markedly repressed the development of IVDD in surgery-induced IVDD rats. These results indicated that the expression of Grem1 was positively correlated with the severity of intervertebral disc degeneration, and Grem1 siRNA could inhibit Grem1-induced apoptosis and extracellular matrix alterations by mediating the TGF-β/Smad signaling pathway. This study may provide a therapeutic strategy for alleviating inflammation-induced apoptosis associated with intervertebral disc degeneration.

Effects of Secondary Elements on Vortex-Induced Vibration of a Streamlined Box Girder

Xingyu Chen,Fang Qiu,Haojun Tang,Yongle Li,Xinyu Xu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.1

Box girders are aerodynamically favorable, and the paper presents a study on the vortex-induced vibration (VIV) of this girder type at large angles of attack. Taking a box girder as an example, the form of the guardrails and the position of the maintenance tracks were improved to increase the VIV performance. The aerodynamic mechanism was further investigated according to the change in flow field around the girder. Results showed that the VIV performance of the box girder at positive angles of attack is worse. Improving secondary elements is an effective way to increase the VIV performance. Adding four rectangle bars above the original guardrails could achieve the target by preventing the generation of the vortex and blocking its movement. Moving the maintenance tracks inwards with a reasonable distance could also achieve the target as the flow passes through the girder more smoothly. With the combination of the optimal form of the guardrails and the optimal position of the maintenance tracks, the VIV performance of the bridge is higher. The countermeasures provide reference for the inhibition of the VIV of box girders.

Achalasia: The Current Clinical Dilemma and Possible Pathogenesis

Xingyu Jia,Songfeng Chen,Qianjun Zhuang,Niandi Tan,Mengyu Zhang,Yi Cui,Jinhui Wang,Xiangbin Xing,Yinglian Xiao 대한소화기 기능성질환∙운동학회 2023 Journal of Neurogastroenterology and Motility (JNM Vol.29 No.2

Achalasia is a primary esophageal motility disorder manifested by dysphagia and chest pain that impair patients’ quality of life, and it also leads to chronic esophageal inflammation by food retention and increases the risk of esophageal cancer. Although achalasia has long been reported, the epidemiology, diagnosis and treatment of achalasia are not fully understood. The current clinical dilemma of achalasia is mainly due to its unclear pathogenesis. In this paper, epidemiology, diagnosis treatment, as well as possible pathogenesis of achalasia will be reviewed and summarized. The proposed hypothesis on the pathogenesis of achalasia is that genetically susceptible populations potentially have a higher risk of infection with viruses, triggering autoimmune and inflammation responses to inhibitory neurons in lower esophageal sphincter.

Gestational weight gain of multiparas and risk of primary preeclampsia: a retrospective cohort study in Shanghai

Chen Chao,Lei Zhijun,Xiong Yaoxi,Ni Meng,He Biwei,Gao Jing,Zheng Panchan,Xie Xianjing,He Chengrong,Yang Xingyu,Cheng Weiwei 대한고혈압학회 2023 Clinical Hypertension Vol.29 No.-

Background In all studies conducted so far, there was no report about the correlation between excessive gestational weight gain (GWG) and the risk of preeclampsia (PE) in multiparas, especially considering that multiparity is a protective factor for both excessive GWG and PE. Thus, the aim of this retrospective cohort study was to determine whether GWG of multiparas is associated with the increased risk of PE. Methods This was a study with 15,541 multiparous women who delivered in a maternity hospital in Shanghai from 2017 to 2021, stratifed by early-pregnancy body mass index (BMI) category. Early-pregnancy body weight, height, week-specifc and total gestational weight gain as well as records of antenatal care were extracted using electronic medical records, and antenatal weight gain measurements were standardized into gestational age-specifc z scores. Results Among these 15,541 multiparous women, 534 (3.44%) developed preeclampsia. The odds of preeclampsia increased by 26% with every 1 z score increase in pregnancy weight gain among normal weight women and by 41% among overweight or obese women. For normal weight women, pregnant women with preeclampsia gained more weight than pregnant women without preeclampsia beginning at 25 weeks of gestation, while accelerated weight gain was more obvious in overweight or obese women after 25 weeks of gestation. Conclusions In conclusion, excessive GWG in normal weight and overweight or obese multiparas was strongly associated with the increased risk of preeclampsia. In parallel, the appropriate management and control of weight gain, especially in the second and third trimesters, may lower the risk of developing preeclampsia.

Using multi-type sensor measurements for damage detection of shear connectors in composite bridges under moving loads

Xingyu Fan,Jun LI,Hong Hao,Zhi-Wei Chen 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.20 No.5

This paper proposes using the multi-type sensor vibration measurements, such as from a relative displacement sensors and a traditional accelerometer for the damage detection of shear connectors in composite bridge under moving loads. Hilbert-Huang Transform (HHT) spectra of these responses will be fused with a data fusion approach i.e., Dempster-Shafer method, to detect the damage of shear connectors. Experimental studies on a composite bridge model in the laboratory are conducted to demonstrate the effectiveness and performance of using the proposed approach in detecting the damage of shear connectors in composite bridges. Both undamaged and damaged scenarios are considered. The detection results with the data fusion of multi-type sensor measurements show a more reliable and robust performance and accuracy, avoiding the false identifications.

Annexin A2 gene interacting with viral matrix protein to promote bovine ephemeral fever virus release

Lihui Chen,Xingyu Li,Hongmei Wang,Peili Hou,Hongbin He 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.2

Bovine ephemeral fever virus (BEFV) causes bovine ephemeral fever, which can produce considerable economic damage to the cattle industry. However, there is limited experimental evidence regarding the underlying mechanisms of BEFV. Annexin A2 (AnxA2) is a calcium and lipid-conjugated protein that binds phospholipids and the cytoskeleton in a Ca2+-dependent manner, and it participates in various cellular functions, including vesicular trafficking, organization of membrane domains, and virus proliferation. The role of the AnxA2 gene during virus infection has not yet been reported. In this study, we observed that AnxA2 gene expression was up-regulated in BHK-21 cells infected with the virus. Additionally, overexpression of the AnxA2 gene promoted the release of mature virus particles, whereas BEFV replication was remarkably inhibited after reducing AnxA2 gene expression by using the small interfering RNA (siRNA). For viral proteins, overexpression of the Matrix (M) gene promotes the release of mature virus particles. Moreover, the AnxA2 protein interaction with the M protein of BEFV was confirmed by GST pull-down and co-immunoprecipitation assays. Experimental results indicate that the C-terminal domain (268–334 aa) of AxnA2 contributes to this interaction. An additional mechanistic study showed that AnxA2 protein interacts with M protein and mediates the localization of the M protein at the plasma membrane. Furthermore, the absence of the AnxA2-V domain could attenuate the effect of AnxA2 on BEFV replication. These findings can contribute to elucidating the regulation of BEFV replication and may have implications for antiviral strategy development.

Curcumin represses lipid accumulation through inhibiting ERK1/2-PPAR-γ signaling pathway and triggering apoptosis in porcine subcutaneous preadipocytes

Pan, Shifeng,Chen, Yongfang,Zhang, Lin,Liu, Zhuang,Xu, Xingyu,Xing, Hua Asian Australasian Association of Animal Productio 2022 Animal Bioscience Vol.35 No.5

Objective: Excessive lipid accumulation in adipocytes results in prevalence of obesity and metabolic syndrome. Curcumin (CUR), a naturally phenolic active ingredient, has been shown to have lipid-lowering effects. However, its underlying mechanisms have remained largely unknown. Therefore, the study aims to determine the effect of CUR on cellular lipid accumulation in porcine subcutaneous preadipocytes (PSPA) and to clarify novel mechanisms. Methods: The PSPA were cultured and treated with or without CUR. Both cell counting Kit-8 and lactate dehydrogenase release assays were used to examine cytotoxicity. Intracellular lipid contents were measured by oil-red-o staining extraction and triglyceride quantification. Apoptosis was determined by flow cytometry and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling assay. Adipogenic and apoptosis genes were analyzed by quantitative polymerase chain reaction and Western blot. Results: The CUR dose-dependently reduced the proliferation and lipid accumulation of PSPA. Noncytotoxic doses of CUR (10 to 20 μM) significantly inhibited extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and expression of adipogenic genes peroxisome proliferation-activity receptor-γ (PPAR-γ), CCAAT/enhancer binding protein-α, sterol regulatory element-binding protein-1c, adipocyte protein-2, glucose transporter-4 as well as key lipogenic enzymes fatty acid synthase and acetyl-CoA carboxylase, while ERK1/2 activation significantly reversed CUR-reduced lipid accumulation by increasing PPAR-γ. Furthermore, compared with differentiation induced media treated cells, higher dose of CUR (30 μM) significantly decreased the expression of AKT and B-cell lymphoma-2 (BCL-2), while increased the expression of BCL-2-associated X (BAX) and the BAX/BCL-2 expression ratio, suggesting triggered apoptosis by inactivating AKT and increasing BAX/BCL-2 ratio and Caspase-3 expression. Moreover, AKT activation significantly rescued CUR inhibiting lipid accumulation via repressing apoptosis. Conclusion: These results demonstrate that CUR is capable of suppressing differentiation by inhibiting ERK1/2-PPAR-γ signaling pathway and triggering apoptosis via decreasing AKT and subsequently increasing BAX/BCL-2 ratio and Caspase-3, suggesting that CUR provides an important method for the reduction of porcine body fat, as well as the prevention and treatment of human obesity.

Sliding Mode Control for a Class of Nonlinear Ito Stochastic Systems with State and Input Delays

Yugang Niu,Bei Chen,Xingyu Wang 제어·로봇·시스템학회 2009 International Journal of Control, Automation, and Vol.7 No.3

This paper deals with the problem of sliding mode control (SMC) for a class of nonlinear stochastic systems. The nonlinear uncertainties are unknown and unmatched. There exist state and input delays. A special switching function is designed such that the insensitivity of the system can be guaranteed throughout the entire response of the system from the initial time instance. Both the sliding surface and the sliding mode controller exist if a set of matrix inequalities is feasible. A simulation example is given to illustrate the proposed method.

A novel MOF-derived strategy to construct Cu-doped CeO2 supported PdCu alloy electrocatalysts for hydrogen evolution reaction

Jingrui Ye,Mengjuan Teng,Xingyue Qian,Chao Wan,Guangyu He,Haiqun Chen 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

Hydrogen evolution reactions (HER) via water splitting is of significance for electricity-to-fuel conversion. The pursuits of rationally design and facile synthesis method for efficient HER catalysts have long been asubject of interest. In this work, a bimetallic MOF-derived strategy was constructed to realize doping andalloying of transition metal in parallel and Pd-CuCeOx catalyst was prepared, in which Cu served as dopingelement in CeO2 and secondary metal in Pd-Cu alloy. For the as-synthesized Pd-CuCeOx, an overpotentialof 109 mV is needed to reach a current density of 10 mA cm2 with a Tafel slope of only 30.9 mVdec1. With the low content of precious metal, Pd-CuCeOx exhibited a high TOF value of 6.99 s1, which isabout 3.5 times higher than that of commercial Pt/C. The improved HER performance is attributed to thed-band structure modified by alloying and the enhanced electronic coupling caused by doping.