The Discusion and Optimization Research on HSD17B13 Protein Separation and Purification Technology

Yan Cheng,Zhen Wan,Xiaohong Sun ASCONS 2022 IJASC Vol.4 No.3

Background/Objectives: The Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease that affects nearly a quarter of the world population. Recent studies have shown that there is a close relationship between liver lipid-titrated 17β Hydroxysteroid Dehydrogenase Type 13(HSD17B13)protein and NAFLD. At the same time, the purification of HSD has been trying to find better conditions and methods, at present, the HSD protein separation and purification technology is incomplete, the cost is high, the purity is low, the purification quantity is small and so on. This paper first reviewed the research progress of Steatosis and some basic properties about HSD, such as HSD expression site, Lipid titration function, in vitro catalytic substrates, and the relationship between HSD and liver diseases.. Methods/Statistical analysis: The optimization of HSD purification method is considered be of great help to the further study of its structure and function, so this research put forward two hypotheses to explore its effect on the purification of HSD. The first is to change the kind of tag when expressing plasmid in E. coli, so as to change the adsorption degree of protein with corresponding group and beads, and the second is to change the concentration of different components in Wash Buffer, the aim is to find the best concentration for removing foreign protein and maintaining the adsorption capacity of HSD. Findings: The purity of HSD is closely related to tag species and Wash Buffer concentration in different experimental groups, his-Binding Buffer with 0.5% sodium deoxycholate powder added and Wash Buffer with Tris-HCl 50 mM, NACL 300 mM, Imidazole 40 mM for each component are used. Improvements/Applications: After the better purification effect, the higher purity HSD can pave the way for the future study of its potential substrate and mechanism of action.

Fusion Expression and Immunogenicity of EHEC EspA-Stx2A1 Protein: Implications for the Vaccine Development

Yan Cheng,Youjun Feng,Ping Luo,Jiang Gu,Shu Yu,Wei-jun Zhang,Yan-qing Liu,Qing-xu Wang,Quan-ming Zou,Xu-hu Mao 한국미생물학회 2009 The journal of microbiology Vol.47 No.4

Shiga toxin 2 (Stx2) is a major virulence factor for enterohemorrhagic Escherichia coli (EHEC), which is encoded by λ lysogenic phage integrated into EHEC chromosome. Stx2A1, A1 subunit of Stx2 toxin has gathered extensive concerns due to its potential of being developed into a vaccine candidate. However, the substantial progress is hampered in part for the lack of a suitable in vitro expression system. Here we report use of the prokaryotic system pET-28a::espA-Stx2A1/BL21 to carry out the fusion expression of Stx2A1 which is linked to E. coli secreted protein A (EspA) at its N-terminus. Under the IPTG induction, EspA- Stx2A1 fusion protein in the form of inclusion body was obtained successfully, whose expression level can reach about 40% of total bacterial protein at 25°C, much higher than that at 37°C. Western blot test suggested the refolded fusion protein is of excellent immuno-reactivity with both monoclonal antibodies, which are specific to EspA and Stx2A1, respectively. Anti-sera from Balb/c mice immunized with the EspA-Stx2A1 fusion protein were found to exhibit strong neutralization activity and protection capability in vitro and in vivo. These data have provided a novel feasible method to produce Stx2A1 in large scale in vitro, which is implicated for the development of multivalent subunit vaccines candidate against EHEC O157:H7 infections.

A Study of English Morpheme Acquisition Order by Chinese and Korean EFL Learners

Yan Cheng,이보림 대한언어학회 2020 언어학 Vol.28 No.1

The purpose of this study is to evaluate the two contrasting claims for the order of inflectional morpheme acquisition in English as L2: the natural order hypothesis and the hypothesis claiming L1 effects as a fundamental factor. This study also investigates two additional factors that may influence the acquisition of L2 English morphemes: the learner’s English proficiency level and the data elicitation method. For this goal, it involves 38 Korean and 38 Mandarin Chinese learners of English in college, each group of which is in turn divided into two sub-groups according to their English proficiency level. The accuracy scores for six English inflectional morphemes are obtained from two tasks, a freewriting task through journal entries and a fill-in-the-blank type test. Then the results are compared according to the various factors using Spearman’s rank-order correlations based on TLU (target-like use) scores. The results of this study indicate that different L1 groups of the same proficiency level show different acquisition orders, neither of which supports the natural order hypothesis. The data elicitation method and English proficiency, however, do not seem to significantly affect the order of English morphemes. Based on these results, this study concludes that L1 plays a major role in English inflectional morpheme acquisition by EFL learners. It is also noted that input frequency and the amount of classroom instruction can be other important factors affecting English morpheme acquisition, suggesting the need to increase the inputs of low-ranked but important morphemes in the classroom.

Advances in Medical Needle Technologies – Geometry, Mechanics, Design and Manufacturing

Yancheng Wang,Weisi Li,Peidong Han,Marco Giovannini,Kornel Ehmann,Albert Shih 한국생산제조학회 2014 한국생산제조시스템학회 학술발표대회 논문집 Vol.2014 No.9(2)

Overview of the development of smart base isolation system featuring magnetorheological elastomer

Yancheng Li,Jianchun Li 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.1

Despite its success and wide application, base isolation system has been challenged for its passive nature, i.e., incapable of working with versatile external loadings. This is particularly exaggerated during near-source earthquakes and earthquakes with dominate low-frequency components. To address this issue, many efforts have been explored, including active base isolation system and hybrid base isolation system (with added controllable damping). Active base isolation system requires extra energy input which is not economical and the power supply may not be available during earthquakes. Although with tunable energy dissipation ability, hybrid base isolation systems are not able to alter its fundamental natural frequency to cope with varying external loadings. This paper reports an overview of new adventure with aim to develop adaptive base isolation system with controllable stiffness (thus adaptive natural frequency). With assistance of the feedback control system and the use of smart material technology, the proposed smart base isolation system is able to realize real-time decoupling of external loading and hence provides effective seismic protection against different types of earthquakes.

EXPERIMENTAL STUDY ON PID CONTROL OF MAGNETORHEOLOGICAL SHOCK ABSORBER UNDER IMPACT LOAD

Yancheng Li,Jiong Wang 한국소음진동공학회 2008 한국소음진동공학회 국제학술대회논문집 Vol.2008 No.7

Bearing resistance design of stainless steel bolted connections at ambient and elevated temperatures

Yancheng Cai,Ben Young 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.29 No.2

In recent years, significant progress has been made in developing design rules for stainless steel members, while the investigation on bolted connections is relatively limited, in particular at elevated temperatures. In this paper, experimental and numerical investigations on stainless steel bolted connections at ambient and elevated temperatures from the literature were reviewed. Firstly, the research program that focused on structural behavior of cold-formed stainless steel (CFSS) bolted connections at elevated temperatures carried out by the authors were summarized. Over 400 CFSS single shear and double shear bolted connection specimens were tested. The tests were conducted in the temperature ranged from 22 to 950°C using both steady state and transient state test methods. It is shown that the connection strengths decrease as the temperature increases in the similar manner for the steady state test results and the transient state test results. Generally, the deterioration of the connection strengths showed a similar tendency of reduction to those of the material properties for the same type of stainless steel regardless of different connection types and different configurations. It is also found that the austenitic stainless steel EN 1.4571 generally has better resistance than the stainless steel EN 1.4301 and EN 1.4162 for bolted connections at elevated temperatures. Secondly, extensive parametric studies that included 450 specimens were performed using the verified finite element models. Based on both the experimental and numerical results, bearing factors are proposed for bearing resistances of CFSS single shear and double shear bolted connections that subjected to bearing failure in the temperature ranged from 22 to 950°C. The bearing resistances of bolted connections obtained from the tests and numerical analyses were compared with the nominal strengths calculated from the current international stainless steel specifications, and also compared with the predicted strengths calculated using the proposed design equations. It is shown that the proposed design equations are generally more accurate and reliable than the current design rules in predicting the bearing resistances of CFSS (EN 1.4301, EN 1.4571 and EN 1.4162) bolted connections at elevated temperatures. Lastly, the proposed design rules were further assessed by the available 58 results of stainless steel bolted connections subjected to bearing failure in the literature. It is found that the proposed design rules are also applicable to the bearing resistance design of other stainless steel grades, including austenitic stainless steel (EN 1.4306), ferritic stainless steel (EN 1.4016) and duplex stainless steel (EN 1.4462).

Experimental investigation of carbon steel and stainless steel bolted connections at different strain rates

Yancheng Cai,Ben Young 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.30 No.6

A total of 36 carbon steel and stainless steel bolted connections subjected to shear loading at different strain rates was experimentally investigated. The connection specimens were fabricated from carbon steel grades 1.20 mm G500 and 1.90 mm G450, as well as cold-formed stainless steel types EN 1.4301 and EN 1.4162 with nominal thickness 1.50 mm. The connection tests were conducted by displacement control test method. The strain rates of 10 mm/min and 20 mm/min were used. Structural behaviour of the connection specimens tested at different strain rates was investigated in terms of ultimate load, elongation corresponding to ultimate load and failure mode. Generally, it is shown that the higher strain rate on the bolted connection specimens, the higher ultimate load was obtained. The ultimate loads were averagely 2-6% higher, while the corresponding elongations were averagely 8-9% higher for the test results obtained from the strain rate of 20 mm/min compared with those obtained from the lower strain rates (1.0 mm/min for carbon steel and 1.5 mm/min for stainless steel). The connection specimens were generally failed in plate bearing of the carbon steel and stainless steel. It is shown that increasing the strain rate up to 20 mm/min generally has no effect on the bearing failure mode of the carbon steel and stainless steel bolted connections. The test strengths and failure modes were compared with the results predicted by the bolted connection design rules in international design specifications, including the Australian/New Zealand Standard (AS/NZS4600 2018), Eurocode 3 - Part 1.3 (EC3-1.3 2006) and North American Specification (AISI S100 2016) for cold-formed carbon steel structures as well as the American Specification (ASCE 2002), AS/NZS4673 (2001) and Eurocode 3 - Part 1.4 (EC3-1.4 2015) for stainless steel structures. It is shown that the AS/NZS4600 (2018), EC3-1.3 (2006) and AISI S100 (2016) generally provide conservative predictions for the carbon steel bolted connections. Both the ASCE (2002) and the EC3-1.4 (2015) provide conservative predictions for the stainless steel bolted connections. The EC3-1.3 (2006) generally provided more accurate predictions of failure mode for carbon steel bolted connections than the AS/NZS4600 (2018) and the AISI S100 (2016). The failure modes of stainless steel bolted connections predicted by the EC3-1.4 (2015) are more consistent with the test results compared with those predicted by the ASCE (2002).

Incidence of Online Public Opinion on Guangzhou Simultaneous Renting and Purchasing Policy - A data mining application

Yancheng Wang,Haixian Li 충남대학교 아시아여론연구소 2018 Asian journal for public opinion research Vol.5 No.4

This paper adopts the big data research method, and draws 491 data from the Tianya Forum about the Simultaneous Renting and Purchasing policy of Guangzhou. The qualitative analysis software Nvivo11 is used to cluster the main questions about the Simultaneous Renting and Purchasing policy in the forum. The 36 high-frequency word frequencies are obtained through text clustering. Through rooted theory analysis, the main driving factors for summarizing people's doubts are 9 main categories, 3 core categories, and the model of driving factors for online forums is established. The study finds that resource factors are the most key factor, economic factors are the important drivers, and policy guiding factors are sub-important drivers.

Power distribution strategy based on state of charge balance for hybrid energy storage systems in all-electric ships

Liu, Yancheng,Wang, Honglai,Zhang, Qinjin,Wen, Yuanquan,Hu, Wangbao,Zhang, Hanwen The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.8

During the navigation of all-electric ships, a hybrid energy storage system (HESS) is required to compensate power imbalance and maintain bus voltage stability. For a HESS composed of multiple energy storage (ES) devices, an unreasonable power distribution causes the ES devices with a low state of charge (SoC) to draw from power supply early, which deepens the operating pressure of the other ES devices. This in turn, affects the stable operation of the entire system. To achieve power distribution based on the SoC of different ES devices, a novel power distribution strategy for use in all-electric ships was proposed. In the proposed strategy, the virtual impedance of an ES device is connected with the SoC through exponential functions. As a result, the output power can be dynamically changed according to changes of the SoC. On the premise of obtaining a proper dynamic power distribution among ES devices with complementary characteristics, the SoC balance among ES devices with the same characteristics can be realized. Meanwhile, the bus voltage deviation induced by the virtual resistor is eliminated via an added compensation voltage. The effectiveness of proposed method is verified by both simulations and a StarSim hardware in loop (HIL) experimental platform.