The Dynamic Mechanical Properties for Recycled Aggregate Concrete under Tensile-Compressive States

Zhen-Jun He,Zhi-qiang Wang,Meng-jia Ding,Zhen-wei Wang,Xiao-jie Zhang,Lian-shuo Liu 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.5

The experiments under biaxial tensile-compressive (T-C) complex stress were carried out for two kinds of substitution percentages of recycled coarse aggregate (RCA) on biaxial proportional loading (α = σ1:σ3 =1:0, 0: -1, 0.05: -1, 0.1: -1, 0.25: -1, 0.5: -1, 1: -1 and-1: -1) and four loading deformation rates of 10−5/s, 10−4/s , 10−3/s, and 10−2/s. The research was completed in the static-dynamic true triaxial machine. The experimental phenomena indicate the tensile failure appears in these specimens of recycled aggregate concrete (RAC) under biaxial T-C stress states. The dynamic mechanical behavior for RAC under biaxial T-C loadings was affected by the strain rates, stress ratios and its substitution percentages of RCA. Accompanied by the increase of strain rates, its strength of RAC is improved. As the tensile stress increases, its compressive strength decreases. The T-C strengths for RAC under biaxial T-C states are less than its corresponding uniaxial T-C strengths at a certain identical strain rates, respectively. Considering the effect of loading rates, a new tensile-compressive failure criterion is established under complex stress states.

Preparation and activity evaluation of chrysin-b-Dgalactopyranoside

Zhen-Yuan Zhu,Ling Chen,Fei Liu,Li-Jing Chen,Meng Meng,Hui-Qing Sun,Yong-Min Zhang 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.10

Chrysin-b-D-galactopyranoside was efficiently synthesized, evaluated for its inhibitory activities against H22 cell lines compared with chrysin, the scavenging of hydroxyl radical, DPPH radical and superoxide anion, inhibitory effect against bacteria and fungi. The structures of all compounds were fully characterized by spectroscopic data (NMR, MS). The anti-tumor, antioxidant and antimicrobial activities of chrysin-b-D-galactopyranoside were proved to be enhanced significantly compared with chrysin.

Longitudinal anti-cracking analysis for post-tensioned voided slab bridges

Zhen Zhou,Shao-ping Meng,Zhao Liu 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.43 No.4

Post-tensioned concrete voided slab girders are widely used in highway bridge constructions. To obtain greater section hollow rate and reduce the self-weight, the plate thickness of slab girders are designed to be small with the adoption of flat anchorage system. Since large prestress is applied to the anchor end section, it was found that longitudinal shear cracks are easy to occur along the voided slab girder. The reason is the existence of great shearing effect at the junction area between web and bottom (top) plate in the anchor end section. This paper focuses on the longitudinal anti-cracking problem at the anchor end of post-tensioned concrete voided slab girders. Two possible models for longitudinal anticracking analysis are proposed. Differential element analysis method is adopted to derive the solving formula of the critical cracking state, and then the practical analysis method for longitudinal anti-cracking is established. The influence of some factors on the longitudinal anti-cracking ability is studied. Results show that the section dimensions (thickness of bottom, web and top plate) and prestress eccentricity on web plate are the main factors that influence the anti-cracking ability. Moreover, the proposed method is applied into three engineering examples to make longitudinal anti-cracking verification for the girders. According to the verification results, the design improvements for these girders are determined.

Solid State Reaction Synthesis and Thermoelectric Properties of Ag-Doped Mg₂Si_0.8Ge_0.2

Liu, Qiong Zhen,Zhang, Lian Meng,Shen, Qiang,Jiang, Hong Yi,Wang, Chuan Bin Trans Tech Publications, Ltd. 2006 Key engineering materials Vol.313 No.-

<P>By two-step solid state reaction, Mg2Si0.8Ge0.2 was successfully synthesized .The effect of Ag-doping concentration on the thermoelectric transport properties of p-type Mg2Si0.8Ge0.2 was investigated. With the increasing of Ag-doping concentration, the electrical conductivity σ and Seebeck coefficient α increase correspondingly over the measuring temperature range (300-800K).The peaks of the curves of Seebeck coefficient versus temperature shift towards the lower temperature .When the doping concentration of Ag is 16000ppm(nominal molar percent), the power factor P of Mg2Si0.8Ge0.2 reaches 4.4×10-4W/mK2 at 800K,obviously improved in comparison with the sample with no additive .</P>

Effects of Lactobacillus plantarum SCS2 on blood glucose level in hyperglycemia mice model

Xiao Meng,Yu Qian,Li-Shi Jiang,Jin-Mei Kang,Yan Chen,Juan Wang,Shu-Kun Liu,Zhen-Ming Che,Xin Zhao 한국응용생명화학회 2016 Applied Biological Chemistry (Appl Biol Chem) Vol.59 No.1

In this study, the hyperglycemia mice model was established with 1-week high sugar and fat diet plus with 70 mg/kg body weight of streptozotocin injection for 3 days. Sixty male Kunming mice of 3 weeks old in a specific-pathogen-free grade were divided into six groups randomly, which includes normal group (NG), prevention group (PG), treatment group for low dose (TGL), middle dose (TGM), high dose (TGH), and model group (MG). NG and MG mice were fed with sterile physiological saline (10 mL/kg body weight). PG mice were fed with the concentration of 6.0 × 109 CFU/mL L. plantarum SCS2 suspensions from the second to third week. TGL, TGM, and TGH mice were fed with the concentration of 2.0 × 109, 4.0 × 109, and 6.0 × 109 CFU/mL L. plantarum SCS2 suspensions (10 mL/kg body weight), respectively from fourth to tenth week. The results showed that the fasting and postprandial 2 h blood glucose levels of TGH mice were reduced by L. plantarum SCS2 significantly (p < 0.05) as compared with MG. The body weight of TGH mice came to normal level at tenth week. Content of K+ in plasma of TGH mice was increased and contents of Na+ and Cl− in the plasma of TGH mice were decreased as compared with MG. Meanwhile, content of glycogen in TGH mice was reduced. However, the effect of L. plantarum SCS2 on the prevention of hyperglycemia in PG mice was not significant as compared with NG mice during the experiment. These results suggested that L. plantarum SCS2 showed a hypoglycemic effect on hyperglycemic mice model.

Liquiritin inhibits TGF-β1-induced epithelial mesenchymal transition and extracellular matrix deposition in human renal proximal tubular epithelial cells by suppressing the MAPK signaling

Chen Zhen,Liu Yi jue,Yu Bo,Li Wei,Zhang Mengli,Wu Xian,Gui Feng,Peng Huan,Ai Fen 대한독성 유전단백체 학회 2024 Molecular & cellular toxicology Vol.20 No.3

Background Excessive extracellular matrix (ECM) deposition leads to renal fibrosis, a typical hallmark of chronic kidney disease. Liquiritin is a flavonoid extracted from the rhizome part of Glycyrrhiza glabra and has anti-fibrotic and nephroprotective effects. However, its role and underlying mechanism in renal fibrosis remain unknown. Methods Human renal proximal tubular epithelial cells (HRPTEpiCs) were stimulated with 10 ng/mL TGF-β1 to induce renal fibrosis models in vitro. The morphology of HRPTEpiCs was observed under a light microscope. CCK-8 was utilized to test cell viability. Immunofluorescence staining was conducted to measure α-SMA expression in HRPTEpiCs. RT-qPCR was used to assess relative mRNA expression. The protein levels of ECM markers, epithelial mesenchymal transition (EMT) markers, and MAPK signaling-related molecules in HRPTEpiCs were tested using western blotting. Results TGF-β1-treated HRPTEpiCs showed a fibroblast-like morphology, and the morphology of HRPTEpiCs was restored by liquiritin. Liquiritin suppressed TGF-β1-stimulated ECM deposition and EMT process in HRPTEpiCs. Additionally, liquiritin repressed TGF-β1-induced MAPK signaling activation in HRPTEpiCs. Conclusion Liquiritin mitigates TGF-β1-triggered EMT process and ECM deposition in HRPTEpiCs by inactivating MAPK signaling, thus preventing renal fibrosis. Background Excessive extracellular matrix (ECM) deposition leads to renal fibrosis, a typical hallmark of chronic kidney disease. Liquiritin is a flavonoid extracted from the rhizome part of Glycyrrhiza glabra and has anti-fibrotic and nephroprotective effects. However, its role and underlying mechanism in renal fibrosis remain unknown. Methods Human renal proximal tubular epithelial cells (HRPTEpiCs) were stimulated with 10 ng/mL TGF-β1 to induce renal fibrosis models in vitro. The morphology of HRPTEpiCs was observed under a light microscope. CCK-8 was utilized to test cell viability. Immunofluorescence staining was conducted to measure α-SMA expression in HRPTEpiCs. RT-qPCR was used to assess relative mRNA expression. The protein levels of ECM markers, epithelial mesenchymal transition (EMT) markers, and MAPK signaling-related molecules in HRPTEpiCs were tested using western blotting. Results TGF-β1-treated HRPTEpiCs showed a fibroblast-like morphology, and the morphology of HRPTEpiCs was restored by liquiritin. Liquiritin suppressed TGF-β1-stimulated ECM deposition and EMT process in HRPTEpiCs. Additionally, liquiritin repressed TGF-β1-induced MAPK signaling activation in HRPTEpiCs. Conclusion Liquiritin mitigates TGF-β1-triggered EMT process and ECM deposition in HRPTEpiCs by inactivating MAPK signaling, thus preventing renal fibrosis.

Longitudinal anti-cracking analysis for post-tensioned voided slab bridges

Zhou, Zhen,Meng, Shao-Ping,Liu, Zhao Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.43 No.4

Post-tensioned concrete voided slab girders are widely used in highway bridge constructions. To obtain greater section hollow rate and reduce the self-weight, the plate thickness of slab girders are designed to be small with the adoption of flat anchorage system. Since large prestress is applied to the anchor end section, it was found that longitudinal shear cracks are easy to occur along the voided slab girder. The reason is the existence of great shearing effect at the junction area between web and bottom (top) plate in the anchor end section. This paper focuses on the longitudinal anti-cracking problem at the anchor end of post-tensioned concrete voided slab girders. Two possible models for longitudinal anticracking analysis are proposed. Differential element analysis method is adopted to derive the solving formula of the critical cracking state, and then the practical analysis method for longitudinal anti-cracking is established. The influence of some factors on the longitudinal anti-cracking ability is studied. Results show that the section dimensions (thickness of bottom, web and top plate) and prestress eccentricity on web plate are the main factors that influence the anti-cracking ability. Moreover, the proposed method is applied into three engineering examples to make longitudinal anti-cracking verification for the girders. According to the verification results, the design improvements for these girders are determined.

Alternative Biological Material for Tissue Engineering of the Vagina: Porcine-Derived Acellular Vaginal Matrix

Tian Yanpeng,Liu Yibin,Xiao Yanlai,Li Zhongkang,Zhang Mingle,Chen Liang,Li Zhen,Zhang Wangchao,Zhang Zhiqiang,Kong Desheng,Meng Li,Du Yanfang,Zhang Jingkun,Gao Jingui,Huang Xianghua 한국조직공학과 재생의학회 2024 조직공학과 재생의학 Vol.21 No.2

Background: Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is a severe congenital disorder characterized by vaginal hypoplasia caused by dysplasia of the Müllerian duct. Patients with MRKH syndrome often require nonsurgical or surgical treatment to achieve satisfactory vaginal length and sexual outcomes. The extracellular matrix has been successfully used for vaginal reconstruction. Methods: In this study, we developed a new biological material derived from porcine vagina (acellular vaginal matrix, AVM) to reconstruct the vagina in Bama miniature pigs. The histological characteristics and efficacy of acellularization of AVM were evaluated, and AVM was subsequently transplanted into Bama miniature pigs to reconstruct the vaginas. Results: Macroscopic analysis showed that the neovaginas functioned well in all Bama miniature pigs with AVM implants. Histological analysis and electrophysiological evidence indicated that morphological and functional recovery was restored in normal vaginal tissues. Scanning electron microscopy showed that the neovaginas had mucosal folds characteristics of normal vagina. No significant differences were observed in the expression of CK14, HSP47, and α-actin between the neovaginas and normal vaginal tissues. However, the expression of estrogen receptor (ER) was significantly lower in the neovaginas than in normal vaginal tissues. In addition, AVM promoted the expression of β-catenin, c-Myc, and cyclin D1. These results suggest that AVM might promotes vaginal regeneration by activating the β-catenin/c-Myc/cyclin D1 pathway. Conclusion: This study reveals that porcine-derived AVM has potential application for vaginal regeneration. Background: Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is a severe congenital disorder characterized by vaginal hypoplasia caused by dysplasia of the Müllerian duct. Patients with MRKH syndrome often require nonsurgical or surgical treatment to achieve satisfactory vaginal length and sexual outcomes. The extracellular matrix has been successfully used for vaginal reconstruction. Methods: In this study, we developed a new biological material derived from porcine vagina (acellular vaginal matrix, AVM) to reconstruct the vagina in Bama miniature pigs. The histological characteristics and efficacy of acellularization of AVM were evaluated, and AVM was subsequently transplanted into Bama miniature pigs to reconstruct the vaginas. Results: Macroscopic analysis showed that the neovaginas functioned well in all Bama miniature pigs with AVM implants. Histological analysis and electrophysiological evidence indicated that morphological and functional recovery was restored in normal vaginal tissues. Scanning electron microscopy showed that the neovaginas had mucosal folds characteristics of normal vagina. No significant differences were observed in the expression of CK14, HSP47, and α-actin between the neovaginas and normal vaginal tissues. However, the expression of estrogen receptor (ER) was significantly lower in the neovaginas than in normal vaginal tissues. In addition, AVM promoted the expression of β-catenin, c-Myc, and cyclin D1. These results suggest that AVM might promotes vaginal regeneration by activating the β-catenin/c-Myc/cyclin D1 pathway. Conclusion: This study reveals that porcine-derived AVM has potential application for vaginal regeneration.

Enhancing the performance of LSSVM model in predicting rock fragmentation size via optimization algorithms

Haowen Zheng,Jun Liu,Ruihong Zhuang,Fu-tian Zhao,Meng-yang Zhen,Yue Wang,Zheng Liu 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.9

The prediction of rock fragmentation is critical to improve the efficiency and economy of blasting excavation. In this study, an attempt is made to predict the entire fragmentation size distribution using a least square support vector machine (LSSVM) model. In addition, three optimization algorithms – the bacterial foraging algorithm (BFO), artificial fish swarm algorithm (AFSA), and adaptive particle swarm optimization (APSO) – were used to determine the appropriate parameters of the LSSVM model. In the constructed LSSVM-BFO, LSSVM-AFSA and LSSVM-APSO models, the hole spacing, row spacing, change per delay and stemming were used as the input parameters, while the statistical rock fragmentation size was assigned as the output. The LSSVM model was also employed as a control group for comparing with the optimized models. The above-mentioned models were trained and tested based on a database comprising of 10 datasets collected from in-site testing of Altashi Water Control Project in China. The performance of the proposed models was compared by several statistical criteria. The viability and efficiency of the LSSVM-BFO model were confirmed with an R2 of 0.9960 and an RMSE of 1.8044, which were better than those of the LSSVM-AFSA, LSSVM-APSO and LSSVM. Last but not least, sensitivity analysis was also executed. The result of sensitivity analysis demonstrated when the size of rock fragmentation of prediction is less 80mm, the most effective parameter will be stemming; otherwise the most effective parameter will be hole spacing.

Crocin alleviates neurotoxicity induced by bupivacaine in SH-SY5Y cells with inhibition of PI3K/AKT signaling

Lin Lili,Chen Zhen,Li Jun,Peng Jianye,Wang Jian,Feng Mingjun,Liu Tiancheng,Zhang Mengli,Wu Xian,Ai Fen,Shen Caijie 한국유전학회 2024 Genes & Genomics Vol.46 No.1

Background Bupivacaine, a common local anesthetic, can cause neurotoxicity and permanent neurological disorders. Crocin has been widely reported as a potential neuroprotective agent in neural injury models. Objective The aim of this study was to investigate the role and regulatory mechanism of crocin underlying bupivacaine-induced neurotoxicity. Method Human neuroblastoma SH-SY5Y cells were treated with bupivacaine and/or crocin for 24 h, followed by detecting cell viability using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The effect of crocin or bupivacaine on SH-SY5Y cell proliferation was measured by Ki67 immunofluorescence assay. The levels of apoptosis-related proteins and the markers in the PI3K/Akt signaling pathway were examined using western blot analysis. The activities of caspase 3, catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were tested using respective commercial assay kits. Flow cytometry analysis was executed for detecting SH-SY5Y cell apoptosis. Result Crocin attenuated bupivacaine-induced neurotoxicity in SH-SY5Y cells. Meanwhile, crocin inhibited SH-SY5Y cell apoptosis induced by bupivacaine via repressing the activity of caspase-3, reducing Bax expression, and elevating Bcl-2 expression. Moreover, crocin mitigated oxidative stress in SH-SY5Y cells by increasing the content of CAT, SOD, GSH-Px and reducing the content of MDA. Additionally, crocin protected against bupivacaine-induced dephosphorylation of Akt and GSK-3β. The protective effects of crocin against bupivacaine-induced neurotoxicity in SH-SY5Y cells were counteracted by the Akt inhibitor. Conclusion These results suggested that crocin may exert a neuroprotective function by promoting cell proliferation and suppressing apoptosis and oxidative stress in SH-SY5Y cells. Thus, crocin might become a promising drug for the treatment of bupivacaine-induced neurotoxicity. Background Bupivacaine, a common local anesthetic, can cause neurotoxicity and permanent neurological disorders. Crocin has been widely reported as a potential neuroprotective agent in neural injury models. Objective The aim of this study was to investigate the role and regulatory mechanism of crocin underlying bupivacaine-induced neurotoxicity. Method Human neuroblastoma SH-SY5Y cells were treated with bupivacaine and/or crocin for 24 h, followed by detecting cell viability using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The effect of crocin or bupivacaine on SH-SY5Y cell proliferation was measured by Ki67 immunofluorescence assay. The levels of apoptosis-related proteins and the markers in the PI3K/Akt signaling pathway were examined using western blot analysis. The activities of caspase 3, catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were tested using respective commercial assay kits. Flow cytometry analysis was executed for detecting SH-SY5Y cell apoptosis. Result Crocin attenuated bupivacaine-induced neurotoxicity in SH-SY5Y cells. Meanwhile, crocin inhibited SH-SY5Y cell apoptosis induced by bupivacaine via repressing the activity of caspase-3, reducing Bax expression, and elevating Bcl-2 expression. Moreover, crocin mitigated oxidative stress in SH-SY5Y cells by increasing the content of CAT, SOD, GSH-Px and reducing the content of MDA. Additionally, crocin protected against bupivacaine-induced dephosphorylation of Akt and GSK-3β. The protective effects of crocin against bupivacaine-induced neurotoxicity in SH-SY5Y cells were counteracted by the Akt inhibitor. Conclusion These results suggested that crocin may exert a neuroprotective function by promoting cell proliferation and suppressing apoptosis and oxidative stress in SH-SY5Y cells. Thus, crocin might become a promising drug for the treatment of bupivacaine-induced neurotoxicity.