Effects of crude extracted proteins from supernatant of BCF-P and EGF on acid secretion

Yuqing Zhao,Tao Guo,Jiaming Qian 대한독성 유전단백체 학회 2015 Molecular & cellular toxicology Vol.11 No.3

I n order to compare the in vitro effects of crude extracts of broth culture filtrate protein (BCF-P) from the supernatant of an H. pylori liquid culture and epidermal growth factor (EGF) on acid secretion by isolated rabbit gastric parietal cells. Isolated rabbit gastric parietal cells were incubated with BCF-P or EGF for 1 and 12 h. Morphological changes were assessed by electron microscopy, and 14C-aminopyrine (14C-AP) uptake and H+-K+ATP mRNA expression were measured. At 50 μg/mL, BCF-P stimulated acid secretion by parietal cells (P<0.05) at 1 h but not at 12 h. At 100 μg/mL, BCF-P significantly inhibited histamine-stimulated acid secretion (P<0.05) and decreased H+- K+ATP mRNA expression in parietal cells, but it was reversed after EGF exposure. Crude extracted proteins from BCF-P damaged the inner cell membrane structure of parietal cells, reduced H+-K+ATP gene expression, and inhibited acid secretion, activities that differed markedly from those of EGF.

Experimental and numerical study on static behavior of grouped large-headed studs embedded in UHPC

Yuqing Hu,Guotang Zhao,Zhiqi He,Jianan Qi,Jingquan Wang 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.1

The static behavior of grouped large-headed studs (d = 30 mm) embedded in ultra-high performance concrete (UHPC) was investigated by conducting push-out tests and numerical analysis. In the push-out test, no splitting cracks were found in the UHPC slab, and the shank failure control the shear capacity, indicating the large-headed stud matches well with the mechanical properties of UHPC. Besides, it is found that the shear resistance of the stud embedded in UHPC is 11.4% higher than that embedded in normal strength concrete, indicating that the shear resistance was improved. Regarding the numerical analysis, the parametric study was conducted to investigate the influence of the concrete strength, aspect ratio of stud, stud diameter, and the spacing of stud in the direction of shear force on the shear performance of the large-headed stud. It is found that the stud diameter and stud spacing have an obvious influence on the shear resistance. Based on the test and numerical analysis results, a formula was established to predict the load-slip relationship. The comparison indicates that the predicted results agree well with the test results. To accurately predict the shear resistance of the stud embedded in UHPC, a design equation for shear strength is proposed. The ratio of the calculation results to the test results is 0.99.

Experimental shear strength evaluation of perfobond shear connector with various hole shapes

Zheng, Shuangjie,Zhao, Chen,Liu, Yuqing Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.2

The perfobond connector, composed of a steel plate with a number of holes, serves as a certain type of shear connector in steel and concrete composite structures. Depending on limits in hole distances and rib heights, various hole shapes including circular-hole and long-hole are alternatives for perfobond connectors. This study presented the results of tests performed on 72 push-out specimens with perfobond connectors. The purpose was to evaluate the shear strength of perfobond connectors with circular-hole and long-hole. The effects of various parameters were investigated, including the hole diameter, the hole length, the hole height, the concrete strength, the existence, diameter and strength of rebar in the hole, the thickness, height and distance of perfobond ribs, and the thickness of concrete slabs. On the basis of 132 push-out test results in references and in this study, an analytical model was proposed by regression analysis to predict the shear strength of perfobond connectors. The proposed equation agreed reasonably well with the experimental results of perfobond connectors with different hole shapes.

A New Roaming Authentication Framework For Wireless Communication

( Xiaowei Li ),( Yuqing Zhang ),( Xuefeng Liu ),( Jin Cao ),( Qianqian Zhao ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.8

Roaming authentication protocol is widely used in wireless network which can enable a seamless service for the mobile users. However, the classical approach requires the home server`s participation during the authentication between the mobile user and the foreign server. So the more the roaming requests are performed the heavier burden will be on the home server. In this paper, we propose a new roaming authentication framework for wireless communication without the home server`s participation. The new roaming authentication protocol in the new framework takes advantage of the ID-based cryptography and provides user anonymity. It has good performance compared with the roaming authentication protocols whose authentication do not need the home server`s participation in terms of security and computation costs. Moreover, a new User-to-User authentication protocol in the new framework is also present. All the authentications proposed in this paper can be regarded as a common construction and can be applied to various kinds of wireless networks such as Cellular Networks, Wireless Mesh Networks and Vehicle Networks.

An investigation on the bearing capacity of steel girder-concrete abutment joints

Chen Liang,Yuqing Liu,Changjun Zhao,Bo Lei,Jieliang Wu 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.3

To achieve a rational detail of the girder-abutment joints in composite integral bridges, and validate the performance of the joints with perfobond connectors, this paper proposes two innovative types of I-shaped steel girder-concrete abutment joints with perfobond connectors intended for the most of bearing capacity and the convenience of concrete pouring. The major difference between the two joints is the presence of the top flange inside the abutments. Two scaled models were investigated with tests and finite element method, and the damage mechanism was revealed. Results show that the joints meet design requirements no matter the top flange exists or not. Compared to the joint without top flange, the initial stiffness of the one with top flange is higher by 7%, and the strength is higher by 50%. The moment decreases linearly in both types of the joints. At design loads, perfobond connectors take about 70% and 50% of the external moment with and without top flange respectively, while at ultimate loads, perfobond connectors take 53% and 26% of the external moment respectively. The ultimate strengths of the reduced sections are suggested to be taken as the bending strengths of the joints.

Experimental shear strength evaluation of perfobond shear connector with various hole shapes

Shuangjie Zheng,Chen Zhao,Yuqing Liu 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.2

The perfobond connector, composed of a steel plate with a number of holes, serves as a certain type of shear connector in steel and concrete composite structures. Depending on limits in hole distances and rib heights, various hole shapes including circular-hole and long-hole are alternatives for perfobond connectors. This study presented the results of tests performed on 72 push-out specimens with perfobond connectors. The purpose was to evaluate the shear strength of perfobond connectors with circular-hole and long-hole. The effects of various parameters were investigated, including the hole diameter, the hole length, the hole height, the concrete strength, the existence, diameter and strength of rebar in the hole, the thickness, height and distance of perfobond ribs, and the thickness of concrete slabs. On the basis of 132 push-out test results in references and in this study, an analytical model was proposed by regression analysis to predict the shear strength of perfobond connectors. The proposed equation agreed reasonably well with the experimental results of perfobond connectors with different hole shapes.

Effect of machining parameters on the stability of separated and unseparated ultrasonic vibration of feed direction assisted milling

Yuemin Zhang,Bo Zhao,Yuqing Wang,Fan Chen 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

A dynamic model is established to study the effect of ultrasonic amplitude, ultrasonic frequency, feed per tooth, and spindle speed trends on separated and unseparated feed ultrasonic milling. This model applied both theory and method, such as linear theory of nonlinear periodic function, as well as the trajectory and full-discretization methods. First, the characteristic of cutter tooth trajectory is articulated, and the differences in the instantaneous chip thickness are analyzed for two types of milling systems. Second, a judging function is proposed, and the model of instantaneous chip thickness is constructed. Third, the time delay differential equations of separated and unseparated feed ultrasonic milling systems are uniformly established using linear theory of nonlinear periodic function. Finally, the time delay differential equations are solved by the full-discretization method. Stability prediction lobe diagrams of the two kinds of feed ultrasonic milling systems are drawn by MATLAB7.1 software. Experimental results indicate that the influence of the processing parameters on the system stability is more sensitive for the separated system than that of the unseparated system. The effect of feed per tooth on stability of two types of systems is the most significant. At approximately 5000 rpm, the feed ultrasonic milling system appears to have a bifurcation flip, which causes a sharp decline in the stability. Therefore, the two types of systems are unsuitable for machining under high speeds. Experimental results confirm the correct effect of these parameter trends on the stability of lobe diagrams.

SVC: Secure VANET-Assisted Remote Healthcare Monitoring System in Disaster Area

( Xuefeng Liu ),( Hanyu Quan ),( Yuqing Zhang ),( Qianqian Zhao ),( Ling Liu ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.3

With the feature of convenience and low cost, remote healthcare monitoring (RHM) has been extensively used in modern disease management to improve the quality of life. Due to the privacy of health data, it is of great importance to implement RHM based on a secure and dependable network. However, the network connectivity of existing RHM systems is unreliable in disaster area because of the unforeseeable damage to the communication infrastructure. To design a secure RHM system in disaster area, this paper presents a Secure VANET-Assisted Remote Healthcare Monitoring System (SVC) by utilizing the unique “store-carry-forward” transmission mode of vehicular ad hoc network (VANET). To improve the network performance, the VANET in SVC is designed to be a two-level network consisting of two kinds of vehicles. Specially, an innovative two-level key management model by mixing certificate-based cryptography and ID-based cryptography is customized to manage the trust of vehicles. In addition, the strong privacy of the health information including context privacy is taken into account in our scheme by combining searchable public-key encryption and broadcast techniques. Finally, comprehensive security and performance analysis demonstrate the scheme is secure and efficient.

Inhibition of miR-146a-5p and miR-8114 in Insulin-Secreting Cells Contributes to the Protection of Melatonin against Stearic Acid-Induced Cellular Senescence by Targeting Mafa

Shenghan Su,Qingrui Zhao,Lingfeng Dan,Yuqing Lin,Xuebei Li,Yunjin Zhang,Chunxiao Yang,Yimeng Dong,Xiaohan Li,Romano Regazzi,Changhao Sun,Xia Chu,Huimin Lu 대한내분비학회 2022 Endocrinology and metabolism Vol.37 No.6

Background: Chronic exposure to elevated levels of saturated fatty acids results in pancreatic β-cell senescence. However, targets and effective agents for preventing stearic acid-induced β-cell senescence are still lacking. Although melatonin administration can protect β-cells against lipotoxicity through anti-senescence processes, the precise underlying mechanisms still need to be explored. Therefore, we investigated the anti-senescence effect of melatonin on stearic acid-treated mouse β-cells and elucidated the possible role of microRNAs in this process. Methods: β-Cell senescence was identified by measuring the expression of senescence-related genes and senescence-associated β-galactosidase staining. Gain- and loss-of-function approaches were used to investigate the involvement of microRNAs in stearic acid-evoked β-cell senescence and dysfunction. Bioinformatics analyses and luciferase reporter activity assays were applied to predict the direct targets of microRNAs. Results: Long-term exposure to a high concentration of stearic acid-induced senescence and upregulated miR-146a-5p and miR-8114 expression in both mouse islets and β-TC6 cell lines. Melatonin effectively suppressed this process and reduced the levels of these two miRNAs. A remarkable reversibility of stearic acid-induced β-cell senescence and dysfunction was observed after silencing miR-146a-5p and miR-8114. Moreover, V-maf musculoaponeurotic fibrosarcoma oncogene homolog A (Mafa) was verified as a direct target of miR-146a-5p and miR-8114. Melatonin also significantly ameliorated senescence and dysfunction in miR-146a-5pand miR-8114-transfected β-cells. Conclusion: These data demonstrate that melatonin protects against stearic acid-induced β-cell senescence by inhibiting miR-146a-5p and miR-8114 and upregulating Mafa expression. This not only provides novel targets for preventing stearic acid-induced β-cell dysfunction, but also points to melatonin as a promising drug to combat type 2 diabetes progression.

New dammarane-type triterpenoids from the leaves of Panax notoginseng and their protein tyrosine phosphatase 1B inhibitory activity

Dawei Li,Jiaqing Cao,Xiuli Bi,Xichun Xia,Wei Li,Yuqing Zhao 고려인삼학회 2014 Journal of Ginseng Research Vol.38 No.1

Background: Panax notoginseng has been used as a general tonic agent to invigorate human body for millennia in China and continued to be used until present. Methods: Some chromatographic methods were performed to isolate pure triterpenoids, and their structures were determined by nuclear magnetic resonance (NMR) experiments. Anti-diabetes activities of isolated compounds were evaluated through their inhibitory activity of protein tyrosine phosphatase 1B (PTP1B) enzyme. Results and Conclusion: Three new dammarane-type triterpenoids, notoginsenoside-LX (1), notoginsenoside-LY (2), and notoginsenoside-FZ (3) together with eighteen known compounds were isolated from the Panax notoginseng leaves. The structure-activity relationship of the compounds with dammaranetype triterpenoids and their PTP1B inhibitory activity were also reported. Results showed that compounds 2, 15, 20, and 21 can significantly inhibit the enzyme activity of PTP1B in a dose-dependent manner, with inhibitory concentration 50 (IC50) values of 29.08 mM, 21.27 μM, 28.12 μM, and 26.59 μM, respectively. The results suggested that Panax notoginseng leaves might have potential as a new therapeutic agent for the treatment of diabetes.