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Lan Hong,Guo-Hua Gong,Li Yu,Ming-Xia Song,Xun Cui,Zhe-Shan Quan 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.11
A series of 7-alkoxy-4,5-dihydro-[1,2,4]oxadiazolo[4,3-a]quinolin-1-ones was synthesized and theirnegative inotropic effects were evaluated by measuring theleft atrium stroke volume in isolated rabbit heart preparations. All compounds moderated the cardiac workload bydecreasing heart rate and contractility (inotropic effects). Among them, compound 6 was found to be best potent witha -28.89 ± 1.91 % decrease in the stroke volume at aconcentration of 3 9 10-5 M in our in vitro study.
The polymorphisms of bovine PCSK1 gene and their associations with growth traits
Limin Shan,Jiajie Sun,Chunlei Zhang,Xingtang Fang,Chuzhao Lei,Xianyong Lan,Hong Chen 한국유전학회 2011 Genes & Genomics Vol.33 No.1
Proprotein convertase 1 (PCSK1) is an endopeptidase involved in proteolytic processing of peptide hormone precursors in granules of the regulated secretory pathway of endocrine cells and mutations in PCSK1 gene are thought to cause obesity. In the present study, based on PCR-SSCP and DNA sequencing methods, polymorphisms of the PCSK1 gene were detected in 858 individuals from five breeds (Nanyang cattle, Qinchuan cattle, Jiaxian cattle, Luxi cattle and Chinese Holstein). The results showed that only P_8 locus showed polymorphisms and 3 synonymous SNPs of PCSK1 gene were identified. Additionally, significant statistical difference was found in bovine birth weight and diplotype MM were 7.35% higher than diplotype XY.
Xiaohui Shan,Xiaoyu Wang,Guang Yang,Ying-Wu Lan,Shengzhong Su,Shipeng Li,Hongkui Liu,Yaping Yuan 한국식물학회 2013 Journal of Plant Biology Vol.56 No.1
DNA methylation plays a vital role in tuning geneexpression in response to environmental stimuli. Here,methylation-sensitive amplified polymorphisms (MSAP)were used to assess the effect of cold stress on the extent andpatterns of DNA methylation in maize seedlings. Overall,cold-induced genome-wide DNA methylation polymorphismsaccounted for 32.6 to 34.8% of the total bands at the differenttreatment time-points. It was demonstrated that the extentand pattern of DNA methylation was induced by cold stressthrough the cold treatment process and that thedemethylation of fully methylated fragments was the maincontributor of the DNA methylation alterations. The sequencesof 28 differentially amplified fragments relevant to stresswere successfully obtained. Under the cold stress, demethylationwas detected in most fragments. BLAST results indicate thatthe homologues of these fragments are involved in manyprocesses, including hormone regulation, cold response,photosynthesis, and transposon activation. The expressionanalysis demonstrated an increase in the transcription of fivedemethylated genes. Despite the fact that DNA methylationchanges and cold acclimation are not directly associated, ourresults may indicate that the specific demethylation of genesis an active and rapid epigenetic response to cold in maizeduring the seedling stage, further elucidating the mechanismof maize adaptation to cold stress.
Rapid Identification and Characterization of Antioxidants from Ligularia fischeri
Xiang-Lan Piao,Xiao-Yuan Mi,Yan-Ze Tian,Qian Wu,Hui-Shan Piao,Zhikai Zeng,Xiangshu Piao,Ding Wang 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.12
The objectives of this study were to investigate the radical-scavenging activity of Ligularia fischeri on oxidative damage by the radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and to rapidly identify the active components using the bioassay-linked fractionation method. The MeOH extract and fractions of CH2Cl2, BuOH, and H2O from L. fischeri showed DPPH radical-scavenging effects in a dose-dependent manner (p < 0.01). In particular, the BuOH fraction had the most effective (p < 0.05) antioxidative capacity. The active constituents from the BuOH fraction of L. fischeri were rapidly isolated by bioassay-linked HPLC method and identified as hyperoside and 2''-acetylhyperoside with potent antioxidant effects against the DPPH radical, with IC50 values of 1.31 and 7.09 μg/mL, respectively. They have not been reported from L. fischeri yet.
Hot-Stamping Die-Cooling System for Vehicle Door Beams
Zhong-de Shan,Yong-sheng Ye,Mi-lan Zhang,Bao-yu Wang 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.
The need for lightweight automobiles has promoted the rapid development of hot stamping. The cooling system of the hotstamping die determines the performance of hot-stamped workpieces. By establishing a simplified hot-stamping model, we determined that the temperature–time curve of a workpiece is an exponential function. Our research results showed that the depth from the die surface to the cooling pipes has the biggest impact on the cooling rate and uniformity of the workpiece; the correct depth must be ensured to obtain a uniform quenching rate. By studying the cooling buffer flumes, we discovered that the water flow in the pipes becomes more uniform with increasing flume width. With an increase in the flume height, the water flow uniformity in the pipes first increased, and then decreased. In addition, augmenting the pipe diameter near the inlet improved the water flow uniformity in the pipes.
Huan-Yan Xu,Xiu-Lan He,Ze Wu,Lian-Wei Shan,Wei-Dong Zhang 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.10
The clay-based Fe-bearing catalyst was successfully prepared through ion-exchange reaction and applied as heterogeneous catalyst for discoloration of acid fuchsine (AF) in an aqueous solution by Fenton-like action.Experimental results demonstrated that the AF discoloration ratios increased by increasing Fe-loaded clay dosage and initial H2O2 concentration, and by decreasing the pH, respectively. The lower the initial AF concentration, the shorter the reaction time needed to achieve complete discoloration of AF. Comparative studies indicated that AF discoloration ratios were much higher in presence of Fe-loaded clay and H2O2 than those in presence of H2O2, raw natural clay or Fe-loaded clay only and raw natural clay and H2O2 jointly. After AF discoloration, there existed no new phases in the clay samples detected by XRD and no change in the clay crystal morphology observed by SEM. A mechanism proposed suggested adsorption and Fenton-like reaction were responsible for discoloration of AF.
Guang-chong Qin,Tao Lan,Qing Qin,Shan-hua Xu,Zong-xing Zhang 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.8
The cross section would be reduced and the material properties of the steel structure would be deteriorated under the corrosion environment, which will have different effects on the earthquake resistant behavior. This paper takes corroded H-steel column as the research object. Firstly, the influence on the failure mode, bearing capacity, hysteretic properties, ductility and hysteretic energy is analyzed from specific factors which consist of different width-to-thickness on flange, different height-to-thickness on web and different axial compression ratios by FEA. The results show that, the area of the hysteresis loop diminishes gradually, the bearing capacity decrease clearly, the accumulative energy dissipation and ductility coefficient decreased continuously, and the degradation laws of buckling load, peak load, hysteretic energy and ductility coefficient of corroded H-steel columns are thereby established. When the thickness of flange decreased by 30%, the peak load decreased by 32% and hysteretic energy decreased by 77%. However, the peak load decreased by 14% and hysteretic energy decreased by 40% when the thickness of web decreased by 30%. When the axial compression ratio is 0.6, and the mass loss ratio of corroded H-steel columns reached 22%, the peak load and hysteretic energy decreased by 28% and 51% respectively. Secondly, the hysteretic model of load-displacement of corroded H-steel members under cyclic loading is proposed based on the simulation results and the degradation model of characteristic point of skeleton line was given. Finally, the evaluation criteria are proposed based on the seismic performance objectives, and the classification of failure types as well as the overall performance evaluation of corroded steel members are carried out.
Shin, Dong Hoon,Li, Shan Hua,Yang, Seung-Won,Lee, Byung Lan,Lee, Myung Kyu,Park, Jong-Wan Blackwell Publishing Ltd 2009 The FEBS journal Vol.276 No.13
<P>Hypoxia and inflammation often develop concurrently in numerous diseases, and both hypoxia-inducible factor (HIF)-1&agr; and nuclear factor-kappaB (NF-&kgr;B) are key transcription factors of stress response genes. An NF-&kgr;B inhibitor, inhibitor of NF-&kgr;B&agr; (I&kgr;B&agr;), was found to interact with factor inhibiting HIF (FIH) and to be hydroxylated by FIH. However, FIH did not functionally regulate I&kgr;B&agr;, and the consequence of the FIH–I&kgr;B&agr; interaction thus remains uncertain. In the present study, we tested the possibility that I&kgr;B&agr; regulates FIH. FIH–I&kgr;B&agr; binding was confirmed by yeast two-hybrid and coimmunoprecipitation analyses. Functionally, I&kgr;B&agr; expression further enhanced the transcriptional activity of HIF-1&agr; under hypoxic conditions. Furthermore, I&kgr;B&agr; knockdown repressed HIF-1&agr; activity. Mechanistically, I&kgr;B&agr; derepressed HIF-1&agr; activity by inhibiting the FIH-mediated Asn803 hydroxylation of HIF-1&agr;. It was also found that I&kgr;B&agr; activated HIF-1&agr; by sequestering FIH from HIF-1&agr;. However, the effect of I&kgr;B&agr; on HIF-1&agr; activity was only observed in atmospheres containing 1% or more of oxygen. After tumor necrosis factor-&agr; treatment, I&kgr;B&agr; downregulation, Asn803 hydroxylation and HIF-1&agr; inactivation all occurred up to 8 h, but subsided later. On the basis of these results, we propose that I&kgr;B&agr; plays a positive regulatory role during HIF-1-mediated gene expression. Therefore, I&kgr;B&agr;, owing to its interactions with NF-&kgr;B and HIF-1&agr;, may play a pivotal role in the crosstalk between the molecular events that underlie inflammatory and hypoxic responses.</P>
Influence of the camber trailing-edge wings on the motion performance of underwater gliders
Liu Yuhong,Xu Shixun,Tian Shan,Lan Shiquan,Deng Shihan,Liu Shuhe,Feng Dengxue 대한조선학회 2022 International Journal of Naval Architecture and Oc Vol.14 No.1
Wings are the main source of lift for Underwater Gliders (UGs) and play a decisive role in their motion performance. The wings of UGs are generally rectangular and symmetrical airfoils. In this study, a mini- UG with flexible camber trailing-edge wings was proposed and developed to investigate the influence of the trailing edge of the wings on the motion performance of UGs. Flexible deformation of the trailing edge was realized using a steer-by-wire actuator. The test results showed that the trailing edge of the wing could realize maximum upward/downward sloping angles of þ16/16. By combining computational fluid dynamics simulations and tank experiments, this study obtained the glide efficiency (in liftdrag ratio) and stable margins of a mini-UG with variable camber trailing-edge wings. The results showed that the angles of attack corresponding to the minimum lift-to-drag ratio were all negative in cases of downward sloping and positive in cases of upward sloping. Moreover, the suitable camber of the trailing edge, that is, downward-sloping trailing edge on descending glides and upward-sloping trailing edge on ascending glides, can not only greatly improve glide efficiency but also benefit flight stability. Tank experiments showed that the lift-to-drag ratio of the mini-UG with appropriate variable camber trailing-edge wings can be increased by at least 25% compared to those with a symmetrical airfoil.