9 results on '"Qiaowen Zheng"'
Search Results
2. Retinoid X receptor agonists attenuates cardiomyopathy in streptozotocin-induced type 1 diabetes through LKB1-dependent anti-fibrosis effects
- Author
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Qinyun Ruan, Jinzhang Zeng, Changsheng Xu, Hong Xie, Dajun Chai, Xiaoyan Lin, Jie Liu, Jinxiu Lin, and Qiaowen Zheng
- Subjects
Agonist ,Male ,medicine.medical_specialty ,Cardiac fibrosis ,medicine.drug_class ,P70-S6 Kinase 1 ,Retinoid X receptor ,Protein Serine-Threonine Kinases ,Streptozocin ,Rats, Sprague-Dawley ,AMP-Activated Protein Kinase Kinases ,Diabetic cardiomyopathy ,Internal medicine ,medicine ,Animals ,Humans ,Bexarotene ,Chemistry ,Ribosomal Protein S6 Kinases, 70-kDa ,General Medicine ,medicine.disease ,Streptozotocin ,Fibrosis ,Rats ,Endocrinology ,Diabetes Mellitus, Type 1 ,Retinoid X Receptors ,Myocardial fibrosis ,Cardiomyopathies ,medicine.drug - Abstract
Diabetic cardiac fibrosis increases ventricular stiffness and facilitates the occurrence of diastolic dysfunction. Retinoid X receptor (RXR) plays an important role in cardiac development and has been implicated in cardiovascular diseases. In the present study, we investigated the effects of RXR agonist treatment on streptozotocin (STZ)-induced diabetic cardiomyopathy (DCM) and the underlying mechanism. Sprague–Dawley (SD) rats induced by STZ injection were treated with either RXR agonist bexarotene (Bex) or vehicle alone. Echocardiography was performed to determine cardiac structure and function. Cardiac fibroblasts (CFs) were treated with high glucose (HG) with or without the indicated concentration of Bex or the RXR ligand 9-cis-retinoic acid (9-cis-RA). The protein abundance levels were measured along with collagen, body weight (BW), blood biochemical indexes and transforming growth factor-β (TGF-β) levels. The effects of RXRα down-regulation by RXRα small interfering RNA (siRNA) were examined. The results showed that bexarotene treatment resulted in amelioration of left ventricular dysfunction by inhibiting cardiomyocyte apoptosis and myocardial fibrosis. Immunoblot with heart tissue homogenates from diabetic rats revealed that bexarotene activated liver kinase B1 (LKB1) signaling and inhibited p70 ribosomal protein S6 kinase (p70S6K). The increased collagen levels in the heart tissues of DCM rats were reduced by bexarotene treatment. Treatment of CFs with HG resulted in significantly reduced LKB1 activity and increased p70S6K activity. RXRα mediated the antagonism of 9-cis-RA on HG-induced LKB1/p70S6K activation changes in vitro. Our findings suggest that RXR agonist ameliorates STZ-induced DCM by inhibiting myocardial fibrosis via modulation of the LKB1/p70S6K signaling pathway. RXR agonists may serve as novel therapeutic agents for the treatment of DCM.
- Published
- 2019
3. Developments in the study of gastrointestinal microbiome disorders affected by FGF19 in the occurrence and development of colorectal neoplasms
- Author
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Liang Xinyun, Yi Zhao, Peiqi Liu, Min Zhang, Qiaowen Zheng, Meichang Peng, and Wang Yan
- Subjects
0301 basic medicine ,Physiology ,Clinical Biochemistry ,Ileum ,Inflammation ,Fibroblast growth factor ,03 medical and health sciences ,0302 clinical medicine ,Insulin resistance ,medicine ,Humans ,Microbiome ,business.industry ,Gastrointestinal Microbiome ,FGF19 ,Cell Biology ,medicine.disease ,Fibroblast Growth Factors ,Gene Expression Regulation, Neoplastic ,030104 developmental biology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Cancer research ,medicine.symptom ,business ,Colorectal Neoplasms ,Hormone - Abstract
Colorectal neoplasms are a type of malignant digestive system tumor that has become the third-highest morbidity tumor in China and the fourth leading cause of cancer-related death worldwide. The role of the gastrointestinal (GI) microbiome in bile acid metabolism, inflammation, and insulin resistance and its strong correlation with the occurrence and development of colorectal neoplasms have gradually led to it becoming a target area of tumor research. Fibroblast growth factor (FGF) 19 is a hormone that is secreted in mainly the ileum and can regulate bile acid biosynthesis, improve inflammation, and regulate insulin resistance. The relationship of the GI microbiome, FGF19 and its carcinogenic activities in colorectal neoplasms enticed us to search for potential targets and research ideas for the clinical diagnosis and treatment of colorectal neoplasms.
- Published
- 2019
4. Modeling of Bond of Sand-Coated Deformed Glass Fibre-Reinforced Polymer Rebars in Concrete
- Author
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Zhiqing Fang, Weichen Xue, Yu Yang, and Qiaowen Zheng
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Bond strength ,Bond ,Glass fiber ,0211 other engineering and technologies ,02 engineering and technology ,Polymer ,Fibre-reinforced plastic ,021001 nanoscience & nanotechnology ,chemistry ,021105 building & construction ,Materials Chemistry ,Ceramics and Composites ,Composite material ,0210 nano-technology ,Beam (structure) - Abstract
In this paper, 30 beam tests, 48 Losberg pullout tests and 6 standard pullout tests were conducted to investigate bond-slip response of sand-coated deformed glass fibre-reinforced polymer (GFRP) rebars in concrete. The specimen parameters varied were concrete strength, embedment length, bar diameter and test method. Two failure modes including pullout failure and splitting failure were observed. The experimental bond stress-slip (τ-s) curves of sand-coated deformed GFRP rebars in concrete in pullout failure included a micro-slippage branch, a slippage branch, a descending branch and a residual branch, while the τ-s curves in splitting failure included a micro-slippage branch and a slippage branch. Based on the tests, a new bond-slip constitutive model for sand-coated deformed GFRP rebars in concrete was presented. Compared with other available models, the model proposed in this paper can provide more reliable simulations of the test results.
- Published
- 2016
5. Bond behavior of sand-coated deformed glass fiber reinforced polymer rebars
- Author
-
Qiaowen Zheng, Zhiqing Fang, Yu Yang, and Weichen Xue
- Subjects
Materials science ,Polymers and Plastics ,Mechanics of Materials ,Bond strength ,Mechanical Engineering ,Bond ,Materials Chemistry ,Ceramics and Composites ,Glass fiber reinforced polymer ,Composite material ,Beam (structure) - Abstract
Bond behavior of sand-coated deformed glass fiber reinforced polymer rebars was experimentally investigated in this study. A total of 84 specimens, including 30 beam specimens, 48 Losberg pullout specimens, and six RILEM/CEB/FIP pullout specimens, were constructed and tested under monotonic loading. Two failure modes including pullout failure and splitting failure were observed. The pullout failure occurred when the embedment length of specimens was less than 5 times glass fiber reinforced polymer rebar diameter, while the splitting failure occurred when embedment length was more than 5 times rebar diameter. The specimens with the embedment length of 5 times bar diameter failed either by glass fiber reinforced polymer rebars pulling out or by concrete splitting. The results also showed that bond strength of sand-coated deformed glass fiber reinforced polymer rebars was, on average, 59–127% that of the deformed steel rebars. With higher concrete strength, higher bond strength of sand-coated deformed glass fiber reinforced polymer rebars was obtained. When rebar diameter or embedment length increased, bond strength of sand-coated deformed glass fiber reinforced polymer rebars decreased. Based on these results, formulas for the bond strength and the development length of glass fiber reinforced polymer rebars were proposed, considering the effects of concrete strength, bar diameter, embedment length, and rebar outer surface.
- Published
- 2014
6. Retinoid X receptor agonists attenuates cardiomyopathy in streptozotocin-induced type 1 diabetes through LKB1-dependent anti-fibrosis effects.
- Author
-
Dajun Chai, Xiaoyan Lin, Qiaowen Zheng, Changsheng Xu, Hong Xie, Qinyun Ruan, Jinxiu Lin, Jie Liu, and Jinzhang Zeng
- Subjects
RETINOID X receptors ,TYPE 1 diabetes ,SMALL interfering RNA ,DIASTOLE (Cardiac cycle) ,RIBOSOMAL proteins ,DIABETIC cardiomyopathy ,CARDIOMYOPATHIES ,CONNECTIN - Abstract
Diabetic cardiac fibrosis increases ventricular stiffness and facilitates the occurrence of diastolic dysfunction. Retinoid X receptor (RXR) plays an important role in cardiac development and has been implicated in cardiovascular diseases. In the present study, we investigated the effects of RXR agonist treatment on streptozotocin (STZ)-induced diabetic cardiomyopathy (DCM) and the underlying mechanism. Sprague-Dawley (SD) rats induced by STZ injection were treated with either RXR agonist bexarotene (Bex) or vehicle alone. Echocardiography was performed to determine cardiac structure and function. Cardiac fibroblasts (CFs) were treated with high glucose (HG) with or without the indicated concentration of Bex or the RXR ligand 9-cis-retinoic acid (9-cis-RA). The protein abundance levels were measured along with collagen, body weight (BW), blood biochemical indexes and transforming growth factor-β (TGF-β) levels. The effects of RXRα down-regulation by RXRα small interfering RNA (siRNA) were examined. The results showed that bexarotene treatment resulted in amelioration of left ventricular dysfunction by inhibiting cardiomyocyte apoptosis and myocardial fibrosis. Immunoblot with heart tissue homogenates from diabetic rats revealed that bexarotene activated liver kinase B1 (LKB1) signaling and inhibited p70 ribosomal protein S6 kinase (p70S6K). The increased collagen levels in the heart tissues of DCM rats were reduced by bexarotene treatment. Treatment of CFs with HG resulted in significantly reduced LKB1 activity and increased p70S6K activity. RXRα mediated the antagonism of 9-cis-RA on HG-induced LKB1/p70S6K activation changes in vitro. Our findings suggest that RXR agonist ameliorates STZ-induced DCM by inhibiting myocardial fibrosis via modulation of the LKB1/p70S6K signaling pathway. RXR agonists may serve as novel therapeutic agents for the treatment of DCM. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
7. Design Equations for Flexural Capacity of Concrete Beams Reinforced with Glass Fiber–Reinforced Polymer Bars
- Author
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Qiaowen Zheng, Fei Peng, and Weichen Xue
- Subjects
Concrete beams ,Materials science ,business.industry ,Flexural modulus ,Three point flexural test ,Mechanical Engineering ,0211 other engineering and technologies ,020101 civil engineering ,02 engineering and technology ,Building and Construction ,Structural engineering ,Fibre-reinforced plastic ,Upper and lower bounds ,0201 civil engineering ,Flexural strength ,Mechanics of Materials ,021105 building & construction ,Ceramics and Composites ,Composite material ,business ,Reinforcement ,Failure mode and effects analysis ,Civil and Structural Engineering - Abstract
The flexural failure mode of concrete beams reinforced with glass fiber-reinforced polymer (GFRP) bars changes from GFRP rupture to concrete crushing as the reinforcement ratio increases. Due to the uncertainties of material strengths, assumptions made in analysis, and variations in locations of reinforcements and dimensions of sections, there is a transition region where both flexural failure modes are possible. An iterative procedure is required when GFRP rupture governs the design. To avoid this iteration, the current American standard adopts a simplified but conservative procedure. In this study, the upper bound of the reinforcement ratio for beams in the transition region is revised. Moreover, a simplified yet rational design equation for calculating the flexural capacity of under-reinforced beams is proposed based on rigorous sectional analyses. Also, alternative design equations based on regression analyses are developed to predict the flexural capacity of beams in the transition region and...
- Published
- 2016
8. Design Equations for Flexural Capacity of Concrete Beams Reinforced with Glass Fiber–Reinforced Polymer Bars.
- Author
-
Weichen Xue, Fei Peng, and Qiaowen Zheng
- Subjects
FLEXURAL strength ,CONCRETE beams ,GLASS fibers ,COPOLYMERS ,BUILDING reinforcement ,REGRESSION analysis - Abstract
The flexural failure mode of concrete beams reinforced with glass fiber-reinforced polymer (GFRP) bars changes from GFRP rupture to concrete crushing as the reinforcement ratio increases. Due to the uncertainties of material strengths, assumptions made in analysis, and variations in locations of reinforcements and dimensions of sections, there is a transition region where both flexural failure modes are possible. An iterative procedure is required when GFRP rupture governs the design. To avoid this iteration, the current American standard adopts a simplified but conservative procedure. In this study, the upper bound of the reinforcement ratio for beams in the transition region is revised. Moreover, a simplified yet rational design equation for calculating the flexural capacity of under-reinforced beams is proposed based on rigorous sectional analyses. Also, alternative design equations based on regression analyses are developed to predict the flexural capacity of beams in the transition region and over-reinforced beams, respectively. Moreover, the performance of the proposed equations is compared to that of design equations of recent standards by comparing their predictions with experimental results of 173 GFRP reinforced concrete beams collected from the available literature. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
9. Modeling of Bond of Sand-coated Deformed Glass Fibre-reinforced Polymer Rebars in Concrete.
- Author
-
Weichen Xue, Yu Yang, Qiaowen Zheng, and Zhiqing Fang
- Subjects
CHEMICAL bonds ,SURFACE coatings ,DEFORMATIONS (Mechanics) ,REINFORCING bars ,CONCRETE construction - Abstract
In this paper, 30 beam tests, 48 Losberg pullout tests and 6 standard pullout tests were conducted to investigate bond-slip response of sand-coated deformed glass fibre-reinforced polymer (GFRP) rebars in concrete. The specimen parameters varied were concrete strength, embedment length, bar diameter and test method. Two failure modes including pullout failure and splitting failure were observed. The experimental bond stress-slip (τ-s) curves of sand-coated deformed GFRP rebars in concrete in pullout failure included a micro-slippage branch, a slippage branch, a descending branch and a residual branch, while the τ-s curves in splitting failure included a micro-slippage branch and a slippage branch. Based on the tests, a new bond-slip constitutive model for sand-coated deformed GFRP rebars in concrete was presented. Compared with other available models, the model proposed in this paper can provide more reliable simulations of the test results. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
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