Atrial secretion of ANP is suppressed in renovascular hypertension: shifting of ANP secretion from atria to the left ventricle

Tan, Rui,Ahn, You Mee,Kim, Hye Yoom,Lee, Yun Jung,Cho, Kyung Woo,Kang, Dae Gill,Lee, Ho Sub American Physiological Society 2018 American journal of physiology, Heart and circulat Vol.315 No.3

<P> In the present study, the change in secretion of atrial natriuretic peptide (ANP) from the atria was defined in hypertension accompanied by ventricular hypertrophy and increased synthesis of ANP. To identify the change of the secretion and mechanisms involved, experiments were performed in isolated perfused beating atria from sham-operated normotensive and renovascular hypertensive rats. Expression of ANP, natriuretic peptide receptor (NPR)-C, components of the renin-angiotensin system, and muscarinic signaling pathway was measured in cardiac tissues. Basal levels of ANP secretion and acetylcholine (ACh)- and stretch-induced activation of ANP secretion were suppressed in the atria from hypertensive compared with normotensive rats. ACh increased ANP secretion via M2 muscarinic ACh receptor-ACh-sensitive K<SUP>+</SUP> channel signaling. In hypertensive rats, ANP concentration increased in the left ventricle but decreased in the right ventricle. The atrial concentration of ANP was not changed in hypertensive compared with normotensive rats. ANP mRNA expression was accentuated in the left ventricle but suppressed in the other cardiac chambers in the hearts of hypertensive rats. NPR-C expression was inversely related to ANP mRNA levels. Angiotensin II type 1 receptor (AT1R) expression was accentuated in the cardiac chambers from hypertensive rats compared with normotensive rats, whereas angiotensin II type 2 receptor, M2 muscarinic receptor, and Kir3.4 channels were suppressed. AT1R blockade with losartan reversed the change observed in hypertensive rats. The present findings indicate that renovascular hypertension shifts the major site of ANP secretion and synthesis from the atria to the left ventricle through modulation of the expression of ANP, NPR-C, AT1R, and the M2 muscarinic signaling pathway. </P><P> NEW & NOTEWORTHY Renovascular hypertension suppresses the atrial secretion of ANP and shifts the major site of the regulation of ANP secretion and synthesis from atria to the hypertrophied left ventricle possibly via modulation of the expression of ANP, natriuretic peptide receptor-C, angiotensin II subtype 1 receptor, and M2 muscarinic signaling pathway. </P>

중국대학 교양 스키수업 교사행동유형에 따른 학습태도가 학습몰입에 미치는 영향

담예(Tan rui),라춘림(Luo chunlin),강건흠(Kang jianxin),이염삼(Li yansen),조현철(Cho, Hyun-Chul),김현륜(Kim, Hyun-Ryun) 한국체육과학회 2020 한국체육과학회지 Vol.29 No.6

This study selected 137 students who were enrolled in liberal arts and sports at Harbin University in China as subjects for the study in order to investigate the effect of the behavioral types of liberal arts ski class leaders on learning attitude and learning commitment. Data processing was analyzed as follows using SPSS Windows 22.0 Version. Frequency analysis was performed for general characteristics, and exploratory factor analysis and reliability verification (Cronbach’s α) were performed to verify the validity and reliability between questions. In order to analyze the influence of the ski instructor’s teacher guidance behavior type, learning attitude, and learning commitment, a correlation analysis and multiple regression analysis were conducted to derive the research results. First, it was found that the type of teacher guidance behavior (professor and instruction behavior, democratic behavior, social support behavior, positive compensation behavior) had a partial influence on learning attitude. Second, it was found that the type of teacher guidance behavior (professor and instruction behavior, democratic behavior, social support behavior, positive reward behavior) had a partial effect on learning commitment.

Bridging therapies to liver transplantation for hepatocellular carcinoma: A bridge to nowhere?

Chun Han Nigel Tan,Yue Yu,Yan Rui Nicholas Tan,Boon Leng Kieron Lim,Shridhar Ganpathi Iyer,Krishnakumar Madhavan,Alfred Wei Chieh Kow 한국간담췌외과학회 2018 Annals of hepato-biliary-pancreatic surgery Vol.22 No.1

Backgrounds/Aims: Liver Transplantation (LT) is a recognized treatment for Hepatocellular Carcinoma (HCC). The role of Bridging Therapies (BT) remains controversial. Methods: From January 2001 to October 2012, 192 patients were referred to the National University Hospital, Singapore for consideration of LT for HCC. Sixty-five patients (33.8%) were found suitable for transplant and were placed on the waitlist. Analysis was performed in these patients. Results: The most common etiology of HCC was Hepatitis B (n=28, 43.1%). Thirty-six patients (55.4%) received BT. Seventeen patients (47.2%) received TACE only, while 10 patients (27.8%) received radiofrequency ablation (RFA) only. The remaining patients received a combination of transarterial chemoembolization (TACE) and RFA. Baseline tumor and patient characteristics were comparable between the two groups. The overall dropout rate was 44.4% and 31.0% in the BT and non-BT groups, respectively (p=0.269). The dropout rate due to disease progression beyond criteria was 6.9% (n=2) in the non-bridged group and 22.2% (n=8) in the bridged group (p=0.089). Thirty-nine patients (60%) underwent LT, of which all patients who underwent Living Donor LT did not receive BT (n=4, 21.1%, p=0.030). The median time to LT was 180 days (range, 20-558 days) in the non-BT group and 291 days (range, 17-844 days) in the BT group (p=0.214). There was no difference in survival or recurrence between the BT and non-BT groups (p=0.862). Conclusions: BT does not influence the dropout rate or survival after LT but it should be considered in patients who are on the waitlist for more than 6 months.

Synergistic coordination of polyethylene glycol with ClpB/DnaKJE bichaperone for refolding of heat-denatured malate dehydrogenase

Nian, Rui,Kim, Duck Sang,Tan, Lihan,Kim, Chan-Wha,Choe, Woo-Seok Wiley (John WileySons) 2009 Biotechnology progress Vol.25 No.4

<P>The use of polyethylene glycol (PEG) as a refolding additive to a refolding cocktail comprising the molecular bichaperone ClpB and DnaKJE significantly enhances chaperone-mediated refolding of heat-denatured malate dehydrogenase (MDH). The critical factor to affect the refolding yield is the time point of introducing PEG to the refolding cocktail. The refolding efficiency reached approximately 90% only when PEG was added at the beginning of refolding reaction. The synergistic coordination of an inexpensive refolding additive PEG with the ClpB/DnaKJE bichaperone system may provide an economical route to further enhance the efficacy of ClpB/DnaKJE refolding cocktail approach, facilitating its implementation in large-scale refolding processes.</P>

Chromatographic biopanning for the selection of peptides with high specificity to Pb²⁺ from phage displayed peptide library

Nian, Rui,Kim, Duck Sang,Nguyen, Thuong,Tan, Lihan,Kim, Chan-Wha,Yoo, Ik-Keun,Choe, Woo-Seok Elsevier 2010 Journal of chromatography Vol.1217 No.38

<P><B>Abstract</B></P><P>Toxic heavy metal pollution is a global problem occurring in air, soil as well as water. There is a need for a more cost effective, renewable remediation technique, but most importantly, for a recovery method that is selective for one specific metal of concern. Phage display technology has been used as a powerful tool in the discovery of peptides capable of exhibiting specific affinity to various metals or metal ions. However, traditional phage display is mainly conducted in batch mode, resulting in only one equilibrium state hence low-efficiency selection. It is also unable to monitor the selection process in real time mode. In this study, phage display technique was incorporated with chromatography procedure with the use of a monolithic column, facilitating multiple phage-binding equilibrium states and online monitoring of the selection process in search of affinity peptides to Pb<SUP>2+</SUP>. In total, 17 candidate peptides were found and their specificity toward Pb<SUP>2+</SUP> was further investigated with bead-based enzyme immunoassay (EIA). A highly specific Pb<SUP>2+</SUP> binding peptide ThrAsnThrLeuSerAsnAsn (TNTLSNN) was obtained. Based on our knowledge, this is the first report on a new chromatographic biopanning method coupled with monolithic column for the selection of metal ion specific binding peptides. It is expected that this monolith-based chromatographic biopanning will provide a promising approach for a high throughput screening of affinity peptides cognitive of a wide range of target species.</P>

DEM numerical study on mechanical behaviour of coal with different water distribution models

Lihai Tan,Xin Cai,Ting Ren,Xiaohan Yang,Yichao Rui 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.5

The mechanical behaviour and stability of coal mining engineering underground is significantly affected by ground water. In this study, nuclear magnetic resonance imaging (NMRI) technique was employed to determine the water distribution characteristics in coal specimens during saturation process, based on which the functional rule for water distribution was proposed. Then, using discrete element method (DEM), an innovative numerical modelling method was developed to simulate water-weakening effect on coal behaviour considering moisture content and water distribution. Three water distribution numerical models, namely surface-wetting model, core-wetting model and uniform-wetting model, were established to explore the water distribution influences. The feasibility and validity of the surface-wetting model were further demonstrated by comparing the simulation results with laboratory results. The investigation reveals that coal mechanical properties are affected by both water saturation coefficient and water distribution condition. For all water distribution models, micro-cracks always initiate and nucleate in the water-rich area and thus lead to distinct macro fracture characteristics. With the increase of water saturation coefficient, the failure of coal tends to be less violent with less cracks and ejected fragments. In addition, the corewetting specimen is more sensitive to water than specimens with other water distribution models.

Stability of Hybrid Impulsive and Switching Stochastic Systems with Time-delay

Xuegang Tan,Bin Hu,Zhi-Hong Guan,Rui-Quan Liao,Jiang-Wen Xiao,Yuehua Huang 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4

This paper investigates a model of hybrid impulsive and switching stochastic systems (HISSS) with time-delay. Several stability criteria, including the globally asymptotical and exponential stability criteria in the pth moment and mean square, are established by using Itô formula, a generalized switching Lyapunov functions and some relating techniques. Especially, a more general Lyapunov-Krasivskii functional is constructed, and it is observed that the mean square asymptotic and exponential stability conditions of HISSS are delay-dependent. A numerical example shows that the obtained stability results can reduce the conservativeness.

Increasing Demeclocycline Production in Streptomyces aureofaciens by Manipulating the Expression of a Novel SARP Family Regulator and Its Genes

Yan-Ying Tan,Guang-Yao Zhu,Rui-Fang Ye,Hong-Zhou Zhang,De-Yu Zhu 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.6

Demeclocycline (DMCTC), a tetracycline derivative antibiotic produced by Streptomyces aureofaciens, has attracted attention owing to its high bioavailability, prolonged maintenance of a therapeutic concentration, and greater efficacy against many infectious microorganisms. However, the productivity of the DMCTC-producing strains has remained low. Thus, it is necessary to identify gene-knockout or amplification targets to increase DMCTC production. Here, we demonstrated that ctcB, which encodes a Streptomyces antibiotic regulatory protein (SARP), and ctcC, which encodes a resistance gene, positively regulate the biosynthesis of DMCTC in S. aureofaciens strain DT1. In particular, overexpression of the ctcB gene in S. aureofaciens DT1 significantly enhanced DMCTC production, resulting in increased expression of ctcG, ctcN, ctcQ, ctcH, ctcV, and ctcC. The deletion of ctcB dramatically reduced the DMCTC level, implying that CtcB is an activator of DMCTC biosynthesis. Although overexpression of the ctcC, which encodes a ribosomal protection protein, enhancing DMCTC biosynthesis in S. aureofaciens DT1, the improvement was limited compared with that achieved by ctcB overexpression. This is the first study to identify the role of ctcB and ctcC in DMCTC accumulation; these genes may also be ideal candidate targets for facilitating DMCTC production by other Streptomyces strains.

Plasma treatment of multi-walled carbon nanotubes for lipase immobilization

Xun Cao,Rui Zhang,Wei-min Tan,Ce Wei,Jing Wang,Ze-meng Liu,Ke-quan Chen,Ping-Kai Ouyang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.5

Plasma-modified multiwalled carbon nanotubes (MWNTs) were used as a support to immobilize lipase. The effects of vacuum plasma treatment power, vacuum plasma treatment time, immobilization temperature, immobilization time, and initial protein concentration of the lipase on the amount of lipase immobilized and on the subsequent activity of the immobilized lipase were investigated. The results showed that the adsorption capacity of the plasma-modified MWNTs could reach 0.15 g/g and that the maximal enzyme activity of the immobilized lipase was 520U/g under optimized conditions. Fourier transform infrared (FTIR) analysis and transmission electron microscopy (TEM) were used to characterize the properties of the plasma-modified MWNTs and plasma-modified MWNTslipase, and the results showed that the lipase was successfully immobilized on the plasma-modified MWNTs. Also, the MWNTs-lipase produced an esterification rate of approximately 47% in the synthesis of polyethylene glycol (PEG)-aliphatic esters.

Environmental fatigue correction factor model for domestic nuclear-grade low-alloy steel

Gao, Jun,Liu, Chang,Tan, Jibo,Zhang, Ziyu,Wu, Xinqiang,Han, En-Hou,Shen, Rui,Wang, Bingxi,Ke, Wei Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.8

Low cycle fatigue behaviors of SA508-3 low-alloy steel were investigated in room-temperature air, high-temperature air and in light water reactor (LWR) water environments. The fatigue mean curve and design curve for the low-alloy steel are developed based on the fatigue data in room-temperature and high-temperature air. The environmental fatigue model for low-alloy steel is developed by the environmental fatigue correction factor (F_en) methodology based on the fatigue data in LWR water environments with the consideration of effects of strain rate, temperature, and dissolved oxygen concentration on the fatigue life.