Investigation on the interactions of scutellarin and scutellarein with bovine serum albumin using spectroscopic and molecular docking techniques

Hao Tang,Nian-Guang Li,Zhi-Hao Shi,Yu-Ping Tang,Qian-Ping Shi,Ze-Xi Dong,Peng-Xuan Zhang,Jin-ao Duan 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.10

The binding abilities of scutellarin (Scu) andscutellarein (Scue) with bovine serum albumin (BSA) wereinvestigated using equilibrium dialysis, high performanceliquid chromatography, fluorescence spectroscopy, competitivesite marker and molecular docking. The resultsshowed that the average protein binding ratios of Scu andScue with BSA were (79.85 ± 1.83) and (85.49 ± 1.21) %respectively. Under simulated physiological conditions, thefluorescence data indicated that Scu and Scue bound withBSA through a static mechanism. The thermodynamicparameters indicated that the interactions of Scu-BSA andScue-BSA mainly occurred by van der Waals forces andhydrogen bonds and it was easier for Scue to bind withBSA than Scu, indicating that the glucuronic acid moleculein Scu decreased the binding affinity. Site competitivemarker experiments showed that the binding sites of Scuand Scue mainly located within the sub-domain IIA ofBSA. Furthermore, molecular docking studies indicatedthat one BSA could bind three Scue, while one BSA couldcarry only two Scu. All these results clearly indicated theinteractions of Scu and Scue with BSA, which will lay thefoundation for further research to determine the pharmacologyand pharmacodynamics of Scu and Scue for treatingischemic cerebrovascular disease.

Optimized geometric error sensitivity analysis approach based on stream-ofvariation theory in multi-axis precise motion platform

Hao Tang,Chang Ping Li,Jia Chen,Huimin Kang,Tae Jo Ko,Mianke Du 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.10

In this paper, an optimized error sensitivity analysis (ESA) approach based on stream-of-variation (SOV) theory in multi-axis precise motion platform (MPMP) is introduced. Unlike the conventional ESA method, this approach utilizes stream-of-variation theory to establish error model firstly. By regarding each axis as a station, the error propagation and deviation accumulation processes are clear station by station. Through obtaining the deviations after each station, the sensitive stations can be developed, and corresponding error terms are collected. Thus, by analyzing the appearance frequency of the errors, a precise sensitive order can be developed, and a sensitivity results with different steps is given. Through ignoring the insensitive and irrelevant errors, the computational volume of error model can be saved, and the efficiency can be improved. A case study about a typical MPMP used in laser welding system (LWS) is carried out, and the results indicate that the optimized ESA approach is more efficient and accurate, and it is flexible as well. This ESA approach is not only accurate in developing sensitive levels, but also balancing the systematic accuracy and working efficiency, which is helpful to provide informative guide to engineers.

A novel geometric error modeling optimization approach based on error sensitivity analysis for multi-axis precise motion system

Hao Tang,Changping Li,Zilin Zhang,고태조 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.7

In this paper, a novel error modeling approach for multi-DOF precise motion platform (MPMP) based on the error sensitivity analysis (ESA) is introduced. Sensitivity analysis (SA) is widely adopted for finding the essential parameters in system in mathematical way. This paper leads an error sensitivity analysis based on Monte Carlo thought into geometric error model. Through comparing the variance between the set of evaluated error and corresponding orientation deviations, a sensitive order with several sensitive levels can be developed. Conventional error modeling method only concentrates the systematic accuracy, while calculation efficiency is also important. Thus, this error modeling optimization approach based on sensitivity analysis is beneficial for the high-accuracy and high-quantity manufacture environments, which is more precise and effective. It also can save the computational volume for the calculation in error model. A case study of the new error modeling optimization procedure for six-axis stage in the alignment in optoelectronic packaging system (OPS) is carried out. The time-consumed results indicate that the optimized error model can not only keep high-accuracy requirement, but also improve the computational efficiency, which is informative and effective for MPMP motion control. For large number working situation, the optimized error model is available as well.

Experimental quantum fast hitting on hexagonal graphs

Tang, Hao,Di Franco, Carlo,Shi, Zi-Yu,He, Tian-Shen,Feng, Zhen,Gao, Jun,Sun, Ke,Li, Zhan-Ming,Jiao, Zhi-Qiang,Wang, Tian-Yu,Kim, M. S.,Jin, Xian-Min Springer Science and Business Media LLC 2018 Nature photonics Vol.12 No.12

HeNB-Aided Virtual-Handover for Range Expansion in LTE Femtocell Networks

Tang, Hao,Hong, Peilin,Xue, Kaiping The Korea Institute of Information and Commucation 2013 Journal of communications and networks Vol.15 No.3

Home evolved Node-B (HeNB), also called a femtocell or a femto base station, is introduced to provide high data rate to indoor users. However, two main problems arise in femtocell networks: (1) Small coverage area of HeNB, which results in limited cell-splitting gain and ping-pong handover (HO) problems and (2) high inter-femtocell interference because HeNBs may be densely deployed in a small region. In this study, an efficient cooperation mechanism called an HeNB-aided virtual-HO (HaVHO) scheme is proposed to expand the coverage area of femtocells and to reduce inter-femtocell interference. The cooperation among neighbor HeNBs is exploited in HaVHO by enabling an HeNB to relay the data of its neighbor HeNB without an HO. The HaVHO procedure is compatible with the existing long term evolution specification, and the information exchange overhead in HaVHO is relatively low. To estimate the signal to interference plus noise ratio improvement, the area average channel state metric is proposed, and the amount of user throughput enhancement by HaVHO is derived. System-level simulation shows that HaVHO has a better performance than the other four schemes, such as lesser radio link failure, lesser ping-pong handover, lesser short-stay handover, and higher user throughput.

A geometric error modeling method and trajectory optimization applied in laser welding system

Hao Tang,Zilin Zhang,Changping Li,고태조 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.8

In this paper, a geometric error modeling method is carried out on six-axis motion platform (SMP) in laser welding system (LWS), and an optimized algorithm is proposed for the alignment in LWS based on the error model. First, the topological structure of the given SMP is analyzed, and related homogeneous transformation matrices which are used for standing the orientation of SMP are established. By these matrices, the geometric error model is developed mathematically. Then, the error model is used for predicting the alignment deviations. A corresponding series of experiments for calculating the optical power loss in alignment are employed, and the comparison between simulation and experiments results indicate the validation of the error model. Furthermore, an optimized algorithm is applied to search the optimum aligning trajectory. Compared to conventional method, this algorithm has a broader range in searching extreme value, which can reduce the computational volume and improve the efficiency. It is also beneficial for improving the success rate of escaping from the local minimum spot and finding the optimum alignment spot. The error model is helpful to analyze the error propagation process and improve the alignment efficiency in LWS, which can be applied to other similar multi-axis precise system.

Guest Binding Dynamics with Cucurbit[7]uril in the Presence of Cations

Tang, Hao,Fuentealba, Denis,Ko, Young Ho,Selvapalam, Narayanan,Kim, Kimoon,Bohne, Cornelia American Chemical Society 2011 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.133 No.50

<P>The binding dynamics of R-(+)-2-naphthyl-1-ethylammonium cation (NpH(+)) with cucurbit[7]uril (CB[7]) was investigated. Competitive binding with Na(+) or H(3)O(+) cations enabled the reaction to be slowed down sufficiently for the kinetics to be studied by fluorescence stopped-flow experiments. The binding of two Na(+) cations to CB[7], i.e., CB[7]Na(+) (K(01) = 130 10 M(-1)) and Na(+)CB[7]Na(+) (K(02) = 21 2 M(-1)), was derived from the analysis of binding isotherms and the kinetic studies. NpH(+) binds only to free CB[7] ((1.06 0.05) 10(7) M(-1)), and the association rate constant of (6.3 0.3) 10(8) M(-1) s(-1) is 1 order of magnitude lower than that for a diffusion-controlled process and much higher than the association rate constant previously determined for other CB[n] systems. The high equilibrium constant for the NpH(+)@CB[7] complex is a consequence of the slow dissociation rate constant of 55 s(-1). The kinetics results showed that formation of a complex between a positively charged guest with CB[n] can occur at a rate close to the diffusion-controlled limit with no detection of a stable exclusion complex.</P>

IRS-2 Partially Compensates for the Insulin Signal Defects in IRS-1^-/- Mice Mediated by miR-33

Tang, Chen-Yi,Man, Xiao-Fei,Guo, Yue,Tang, Hao-Neng,Tang, Jun,Zhou, Ci-La,Tan, Shu-Wen,Wang, Min,Zhou, Hou-De Korean Society for Molecular and Cellular Biology 2017 Molecules and cells Vol.40 No.2

Insulin signaling is coordinated by insulin receptor substrates (IRSs). Many insulin responses, especially for blood glucose metabolism, are mediated primarily through Irs-1 and Irs-2. Irs-1 knockout mice show growth retardation and insulin signaling defects, which can be compensated by other IRSs in vivo; however, the underlying mechanism is not clear. Here, we presented an Irs-1 truncated mutated mouse ($Irs-1^{-/-}$) with growth retardation and subcutaneous adipocyte atrophy. $Irs-1^{-/-}$ mice exhibited mild insulin resistance, as demonstrated by the insulin tolerance test. Phosphatidylinositol 3-kinase (PI3K) activity and phosphorylated Protein Kinase B (PKB/AKT) expression were elevated in liver, skeletal muscle, and subcutaneous adipocytes in Irs-1 deficiency. In addition, the expression of IRS-2 and its phosphorylated version were clearly elevated in liver and skeletal muscle. With miRNA microarray analysis, we found miR-33 was down-regulated in bone marrow stromal cells (BMSCs) of $Irs-1^{-/-}$ mice, while its target gene Irs-2 was up-regulated in vitro studies. In addition, miR-33 was down-regulated in the presence of Irs-1 and which was up-regulated in fasting status. What's more, miR-33 restored its expression in re-feeding status. Meanwhile, miR-33 levels decreased and Irs-2 levels increased in liver, skeletal muscle, and subcutaneous adipocytes of $Irs-1^{-/-}$ mice. In primary cultured liver cells transfected with an miR-33 inhibitor, the expression of IRS-2, PI3K, and phosphorylated-AKT (p-AKT) increased while the opposite results were observed in the presence of an miR-33 mimic. Therefore, decreased miR-33 levels can up-regulate IRS-2 expression, which appears to compensate for the defects of the insulin signaling pathway in Irs-1 deficient mice.

Mechanical Properties of High Mg-Content Al-Mg-Sc-Zr Alloy Fabricated by Selective Laser Melting

Hao Tang,Yaoxiang Geng,Jinjie Luo,Junhua Xu,Hongbo Ju,Lihua Yu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8

The efects of process parameters and aging treatment on the microstructure and mechanical properties of selective lasermelting (SLM) fabricated high Mg-content Al-Mg-Sc-Zr aluminum alloy were systematically studied. Our experiment resultsshow that the samples exhibit good processability with porosity less than 1%. The increase of Mg content in Al-Mg-Sc-Zris benefcial to reduce the texture of the alloy. The laser scanning speed has a large infuence on the Vickers hardness ofas-fabricated samples. The maximum microhardness of as-fabricated sample reaches 148±2 HV with a compression yieldstrength of 342±7 MPa. After aging treatment, the distinction in microhardness of the samples obtained under diferent laserscanning speed is obviously reduced, and the mechanical properties of the samples are further improved with a maximummicrohardness of 175±5 HV and a maximum compressive yield strength of 476±10 MPa, which are superior to the knownAl-Mg-Sc-Zr alloy with same Sc and Zr content fabricated by SLM. In this study, a novel high Mg-content Al-Mg-Sc-Zraluminum alloy specifcally for SLM with good processability and mechanical properties was reported.

Golgi Phosphoprotein 2 Down-regulates the Th1 Response in Human Gastric Cancer Cells by Suppressing IL-12A

Tang, Qing-Feng,Ji, Qing,Tang, Yu,Hu, Song-Jiao,Bao, Yi-Jie,Peng, Wen,Yin, Pei-Hao Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Golgi phosphoprotein 2 (GOLPH2) is a very important biomarker in a variety of diseases. Its biological function is not clear, particularly in gastric cancer. To investigate the role of GOLPH2 in human gastric cancer, and determine its effect on the Th1 lymphocyte response, its expression and that of IL-12A were measured by real-time PCR and immunohistochemistry. The relationship between GOLPH2 and IL-12A was analysed statistically. The effect of GOLPH2 on the Th1 lymphocyte response was investigated with an in vitro co-culture system. The results showed that in human gastric cancer, the expression of GOLPH2 was significantly higher and the expression of IL-12A was lower than in normal gastric mucosal tissues, and the expression levels of GOLPH2 and IL-12A were negatively correlated. In addition, obvious down-regulation of the Th1 response was observed when lymphocytes were co-cultured with gastric cancer SGC7901 cells over-expressing GOLPH2. GOLPH2 down-regulated the expression of IL-12A, and inhibited the expression of TNF-${\alpha}$ and IFN-${\gamma}$. The results indicated that GOLPH2 down-regulates the Th1 response via suppression of IL-12A in human gastric cancer, and this might provide a target for the prevention and treatment.