On the hydraulic axial thrust of Francis hydro-turbine

Xing-Ying Ji,Xiao-Bin Li,Wen-Tao Su,Xu Lai,Tian-Xiao Zhao 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.5

We present a new method for the computation of hydraulic axial thrust of Francis hydro-turbine. This approach combines the computation of axial thrust on the crown, band and blade by using the numerical simulation and calculation of the pressure distribution outside the crown and band based on the theory of fluid mechanics. The axial thrusts are calculated for different flow conditions with various suction head and flow rate. The calculated results are consistent with that of experimental test on the prototype hydro-turbine, and this combination is proven to be an effective way to assess the magnitude of hydraulic axial thrust for hydro-turbine. Also, the suction head of the turbine is shown to have significant influence on the hydraulic axial thrust.

A Diterpenoid Acanthoic Acid from <i>Acanthopanax koreanum</i> Protects against <small>D</small>-Galactosamine/Lipopolysaccharide-Induced Fulminant Hepatic Failure in Mice

Nan, Ji-Xing,Jin, Xue-Jun,Lian, Li-Hua,Cai, Xing Fu,Jiang, Ying-Zi,Jin, Hong Ri,Lee, Jung Joon Pharmaceutical Society of Japan 2008 Biological & pharmaceutical bulletin Vol.31 No.4

<P>The hepatoprotective effects of a diterpenoid acanthoic acid isolated from <I>Acanthopanax koreanum</I> N<SMALL>AKAI </SMALL>were evaluated in a <SMALL>D</SMALL>-galactosamine/lipopolysaccharide-induced fulminant hepatic failure mouse model. Mice were pretreated orally with acanthoic acid 12 and 1 h before intraperitoneal injection of <SMALL>D</SMALL>-galactosamine and lipopolysaccharide. Pretreatment with the compound markedly reduced lethal liver injury in experimental animals. The effects were likely associated with a significant decrease in serum tumor necrosis factor (TNF)-α levels, which are correlated not only with those of alanine aminotransferase and aspartate aminotransferase but also with the reduced number of apoptotic hepatocytes in the liver as confirmed using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling method and DNA fragmentation assay. These results suggest that acanthoic acid protects against <SMALL>D</SMALL>-galactosamine/lipopolysaccharide-induced fulminant liver failure at least in part by a mechanism associated with the down-regulation of TNF-α secretion.</P>

Inhibitory effects of piceatannol on human cytomegalovirus (hCMV) in vitro

Wang San-Ying,Zhang Jing,Xu Xiao-Gang,Su Hui-Li,Xing Wen-Min,Zhang Zhong-Shan,Jin Wei-Hua,Dai Ji-Huan,Wang Ya-Zhen,He Xin-Yue,Sun Chuan,Yan Jing,Mao Gen-Xiang 한국미생물학회 2020 The journal of microbiology Vol.58 No.8

Human cytomegalovirus (hCMV) is a ubiquitous herpesvirus, which results in the establishment of a latent infection that persists throughout the life of the host and can be reactivated when the immunity is low. Currently, there is no vaccine for hCMV infection, and the licensed antiviral drugs mainly target the viral enzymes and have obvious adverse reactions. Thus, it is important to search for compounds with antihCMV properties. The present study aimed to investigate the suppressive effects of piceatannol on hCMV Towne strain infection and the putative underlying mechanisms using human diploid fibroblast WI-38 cells. Piceatannol supplementation prevented the lytic changes induced by hCMV infection in WI-38 cells. Furthermore, piceatannol suppressed the expression of hCMV immediate-early (IE) and early (E) proteins as well as the replication of hCMV DNA in a dose-dependent manner. Moreover, hCMV-induced cellular senescence was suppressed by piceatannol, as shown by a decline in the senescence-associated β-galactosidase (SA-β-Gal) activity and decreased production of intracellular reactive oxygen species (ROS). p16INK4a, a major senescence-associated molecule, was dramatically elevated by current hCMV infection that was attenuated by pre-incubation with piceatannol in a dose-dependent manner. These results demonstrated that piceatannol suppressed the hCMV infection via inhibition of the activation of p16INK4a and cellular senescence induced by hCMV. Together, these findings indicate piceatannol as a novel and potent anti-hCMV agent with the potential to be developed as an effective treatment for chronic hCMV infection.

Association of TNF-α-308 and -238 Polymorphisms with Risk of Cervical Cancer: A Meta-analysis

Pan, Feng,Tian, Jing,Ji, Chu-Shu,He, Yi-Fu,Han, Xing-Hua,Wang, Yong,Du, Jian-Ping,Jiang, Feng-Shou,Zhang, Ying,Pan, Yue-Yin,Hu, Bing Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Published data on the associations between tumor necrosis factor-alpha (TNF-${\alpha}$) promoter -308G>A and -238G>A polymorphisms and cervical cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Data were collected from MEDLINE and PubMed databases. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated in a fixed/random effect model. 13 separate studies including 3294 cases and 3468 controls were involved in the meta-analysis. We found no association between TNF-${\alpha}$-308G>A polymorphism and cervical cancer in overall population. In subgroup analysis, significantly elevated risks were found in Caucasian population (A vs. G: OR = 1.43, 95% CI = 1.00-2.03; AA vs. GG: OR = 2.09, 95% CI = 1.34-3.25; Recessive model: OR = 2.09, 95% CI = 1.35-3.25) and African population (GA vs. GG: OR = 1.53, 95% CI = 1.02-2.30). An association of TNF-${\alpha}$-238G>A polymorphism with cervical cancer was found (A vs. G: OR = 0.61, 95% CI = 0.47-0.78; GA vs. GG: OR = 0.59, 95% CI = 0.45-0.77; Dominant model: OR = 0.59, 95% CI = 0.46-0.77). When stratified by ethnicity, similar association was observed in Caucasian population (A vs. G: OR = 0.62, 95% CI = 0.46-0.84; GA vs. GG: OR = 0.59, 95% CI = 0.43-0.82; Dominant model: OR = 0.60, 95% CI = 0.44-0.83). In summary, this meta-analysis suggests that TNF-${\alpha}$-238A allele significantly decreased the cervical cancer risk, and the TNF-${\alpha}$-308G>A polymorphism is associated with the susceptibility to cervical cancer in Caucasian and African population.

The Pattern of Seed Rain in the Broadleaved-Korean Pine Mixed Forest of Xiaoxing`an Mountains, China

Guang Ze Jin,Xing Ci Xie,Yue Ying Tian,Ji Hong Kim 한국임학회 2006 한국산림과학회지 Vol.95 No.5

Preparation, Microwave Absorption and Infrared Emissivity of Ni-doped ZnO/Al Powders by Coprecipitation Method in the GHz Range

Ruiwen Shu,Honglong Xing,Xiaoli Cao,Xiaoli Ji,Dexin Tan,Ying Gan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.4

In this work, Ni-doped ZnO/Al composites were prepared by a facile chemical co-precipitation method. The morphology and structure of the as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), respectively. It was found that the flakelike Al powders were successfully coated by Ni-doped ZnO nanoparticles with slight aggregation and Ni2+ was successfully doped into the crystal lattice of ZnO. Moreover, the effects of ZnO concentration and doped Ni concentration on the infrared emissivity of ZnO/Al composites at the waveband range of 8–14 µm were studied. The results showed that the ZnO/Al composites exhibited the lowest infrared emissivity of 0.34 with 50 wt.% ZnO concentration. Meanwhile, the electromagnetic parameters and microwave absorbing properties of Ni-doped ZnO/Al composites in the frequency range of 2–18 GHz were explored. Significantly, 12 mol.% Ni-doped ZnO/Al composites presented the lowest infrared emissivity of 0.37 and the maximum reflection loss reached -32.5 dB at 13.6 GHz with a thickness of 4.5 mm. The excellent microwave absorbing properties could be attributed to the good impedance match, crystal lattice defects and interfacial polarization. It was believed that the Ni-doped ZnO/Al composites could be used as potential infrared-microwave compatible stealth materials.

Enhanced Microwave Absorption Properties of CeO2 Nanoparticles Supported on Reduced Graphene Oxide

Qing Yin,Honglong Xing,Ruiwen Shu,Xiaoli Ji,Dexin Tan,Ying Gan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.5

In this work, reduced graphene oxide/CeO2 nanocomposites (RGO/CeO2) with two different RGO contents were synthesized using a facile one-step hydrothermal method, and the microwave absorption properties of RGO/CeO2 were investigated for the first time. Morphology and structure analysis shows that the CeO2 nanoparticles are uniformly dispersed on the RGO sheets with average size of 15 nm. The as-prepared RGO/CeO2 exhibits excellent microwave absorbability. An optimal reflection loss (RL) of -32 dB is found at 17 GHz with a coating layer thickness of 1.5 mm. The product with a coating layer thickness of only 2.0 mm shows a bandwidth of 4.3 GHz, corresponding to RL at -10 dB (90% of electromagnetic wave absorption). Compared with pristine RGO or pure CeO2 nanoparticles, the reported nanocomposites achieved both wider and stronger wave absorption in the frequency range of 2–18 GHz. The enhanced microwave absorption properties are attributed to the conductive loss and dielectric loss mainly caused by the higher oxygen vacancy concentration of CeO2 in RGO/CeO2, which is demonstrated by X-ray photoelectron spectroscopy. Moreover, multiple interfacial polarizations occurring in the multi-interfaces between CeO2 and RGO sheets may be beneficial to microwave absorption. RGO/CeO2 could be used as an attractive candidate for the new type of microwave absorptive materials.

Facial Synthesis of Zn-Doped Fe3O4 with Enhanced Electromagnetic Wave Absorption Performance in S and C Bands

Zhenfeng Liu,Honglong Xing,Lei Wang,Dexin Tan,Ying Gan,Xiaoli Ji,Guocai Xu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.8

In this study, Zn-doped Fe3O4 nanoparticles were successfully synthesized by a facile solvothermal method in the presence of sodium dodecyl sulfate (SDS). The morphology, magnetic properties and electromagnetic wave absorbing properties of these materials were characterized. Results showed that Zn2+ played a significant role in the formation of Zn-doped Fe3O4. With the protection of SDS, highly dispersed Fe3O4 nanoparticles were obtained. The nanoparticle size decreased after Zn2+ doping, and the dispersity deteriorated with increasing Zn2+ doping concentration. Zndoped Fe3O4 exhibited excellent electromagnetic wave absorbing property, which resulted in magnetic loss and dielectric loss at an appropriate doping concentration. The minimum reflection loss (RL) was approximately -27.2 dB at 16.9 GHz. As the coating layer thickness increased to 4.0 mm, the bandwidth was approximately 5.0 GHz corresponding to RL below -10 dB, which nearly covered the entire S band (2–4 GHz) and C band (4–8 GHz). The peak frequency of RL and the number of peaks matched the quarter-wave thickness criteria. It was believed that the Zndoped Fe3O4 could be a potential electromagnetic wave absorbing material in S and C bands.

Study on the progressive forming mechanism of multi-step shafts based on convex-end billet in the cross wedge rolling technology

Sutao Han,Xuedao Shu,Taizhu Chen,Ying Chang,Ji Chen,Xing Chen,Wei Xiang 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.12

The deforming process is complicated and both the end concave and the central defect can be easily formed in multi-step shafts shaped by the cross-wedge rolling technology. To realize the accurate forming of multi-step shafts without stub bar, this article breaks the bondage of traditional flat-end billet, and introduces into convex-end billet. Based on established mechanical models and the damage computation principles, the distribution and change features of stress fields, strain fields and microstructures in different segments of the multistep shaft during the progressive forming process are analyzed, and the location of the central defect is predicted. It is found that the concave depth of shaft ends decreases as the length of the convex-end of billet increases, the microcosmic grains are affected by the section shrinkage of the shaft segments and the larger the section shrinkage is, the smaller the size of the microcosmic grain will be. It records the longest duration of maximum stress, the largest fluctuation of lateral stress and the most frequent cycle of transverse strain in the multistep shaft end and therefore the central defect is most likely to occur. The research findings settle a dependable theoretical basis for enhancing the molding quality and realizing the accurate forming for multi-step shafts in cross wedge rolling.

Gentiopicroside Ameliorates the Progression from Hepatic Steatosis to Fibrosis Induced by Chronic Alcohol Intake

( Hong-xu Yang ),( Yue Shang ),( Quan Jin ),( Yan-ling Wu ),( Jian Liu ),( Chun-ying Qiao ),( Zi-ying Zhan ),( Huan Ye ),( Ji-xing Nan ),( Li-hua Lian ) 한국응용약물학회 2020 Biomolecules & Therapeutics(구 응용약물학회지) Vol.28 No.4

In current study, we aimed to investigate whether the gentiopicroside (GPS) derived from Gentiana manshurica Kitagawa could block the progression of alcoholic hepatic steatosis to fibrosis induced by chronic ethanol intake. C57BL/6 mice were fed an ethanol- containing Lieber-DeCarli diet for 4 weeks. LX-2 human hepatic stellate cells were treated with GPS 1 h prior to transforming growth factor-β (TGF-β) stimulation, and murine hepatocyte AML12 cells were pretreated by GPS 1 h prior to ethanol treatment. GPS inhibited the expression of type I collagen (collagen I), α-smooth muscle actin (α-SMA) and tissue inhibitor of metal protease 1 in ethanol-fed mouse livers with mild fibrosis. In addition, the imbalanced lipid metabolism induced by chronic ethanol-feeding was ameliorated by GPS pretreatment, characterized by the modulation of lipid accumulation. Consistently, GPS inhibited the expression of collagen I and α-SMA in LX-2 cells stimulated by TGF-β. Inhibition of lipid synthesis and promotion of oxidation by GPS were also confirmed in ethanol-treated AML12 cells. GPS could prevent hepatic steatosis advancing to the inception of a mild fibrosis caused by chronic alcohol exposure, suggesting GPS might be a promising therapy for targeting the early stage of alcoholic liver disease.