Effect of Joint Stiffness on the Stability of Cable-braced Grid Shells

Xi Wang,Ruo-qiang Feng,Gui-rong Yan,Feng-cheng Liu,Wei-jia Xu 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.4

Bolted joints used in cable-braced grid shells are typically semi-rigid joints, and the joint stiffness has a significant effect on the stability of cable-braced grid shells. The effect of joint stiffness on the stability of cable-braced grid shells is studied in this paper. Based on the experimental results of improved bolted joints, finite element models of elliptic paraboloid cable-braced grid shells with bolted joints are established, and spring elements are used to simulate the joint stiffness. The effect of the joint stiffness on the nonlinear buckling load is studied by changing the joint stiffness. The main conclusions are as follows. First, the joint rotational stiffness has a significant effect on the failure mode. When the joint rotational stiffness is small to a certain extent, the failure mode of cable-braced grid shells changes from overall buckling to local buckling. Second, the nonlinear failure mode is similar to the first-order eigenvalue buckling mode and the maximal compression stress distribution. The structural integrity is weakened, and the maximal steel tube compression stress decreases with the decrease of the joint rotational stiffness. The smaller the joint rotational stiffness, the lower the utilization rate of steel strength. The results suggest that the joint stiffness of elliptic paraboloid cable-braced grid shells should not be less than 20% of the rigid joint stiffness.

Effect of irradiation on the parameters that influence quality characteristics of raw beef round eye

Feng, Xi,Jo, Cheorun,Nam, Ki Chang,Ahn, Dong U. Elsevier 2018 Innovative food science & emerging technologies Vol.45 No.-

<P><B>Abstract</B></P> <P>The objective of this study was to elucidate the relationships among lipid/protein oxidation, color changes, off-taste and off-odor in irradiated raw beef round eye. Raw beef round eye was prepared and irradiated at 0, 1.5, 3.0 and 4.5kGy using a linear accelerator. Significant increases in lipid oxidation and protein oxidation were found in irradiated raw beef round eye, while significant decreases were observed in the color values (L*-, a*-, and b*-value). The degradation of nucleotides can contribute to the taste changes (increase in sourness and decrease in umami taste) in the irradiated raw beef round eye, which was further confirmed by the electronic tongue data. The sulfur volatiles (e.g.: dimethyl disulfide) from the sulfur-containing amino acids increased significantly after irradiation, indicating these are closely related to the off-odor of irradiated beef round eye.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Lipid/protein oxidation was accelerated in raw beef round eye by irradiation. </LI> <LI> After irradiation, color values (L*-, a*-, and b*-value) in raw beef round eye decreased. </LI> <LI> The nucleotides degradation by irradiation can contribute to the taste changes. </LI> <LI> Irradiation off-odor was correlated to dimethyl disulfide and 2-butanone productions. </LI> </UL> </P>

Empirical Study of the Influence of Consumer Relationship Proneness on Customer Loyalty in Service Context

Xi Feng,Mingli Zhang,Jianhua Ye 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.4

Consumer relationship proneness (CRP) reflects a consumer’s relatively stable and conscious tendency to engage in relationships. This study takes CRP as an important consumer individual trait and examines the influence of CRP on customer loyalty in service environment from perspective of relational benefits (i.e. confidence benefits, social benefits, special treatment benefits). Concept model is proposed to explain the influence. Then SEM (structural equation modeling) is used to analyze the data collected from online survey to test the proposed model. Empirical results show that CRP has direct influence on customer loyalty. The results also show that CRP indirectly relates to customer loyalty via its impact on perceived confidence benefits and social benefits. This study deepens the understanding about the importance of CRP and provides insights into development and implement of customer relationship management and relationship marketing for service enterprises.

Research Articles : The Influence of Challenge on Cathepsin B and D Expression Patterns in the Silkworm Bombyx mori L

( Feng Yao Wu ),( Feng Ming Zou ),( Jun Qiang Jia ),( Sheng Peng Wang ),( Guo Zheng Zhang ),( Xi Jie Guo ),( Zhong Zheng Gui ) 한국잠사학회 2011 International Journal of Industrial Entomology Vol.23 No.1

Cathepsins are well-characterized proteases that are ubiquitously expressed in lysosomes. Previous work revealed that Bombyx mori cathepsins B and D are expressed in the fat body and undergo decomposition during larval-pupal metamorphosis. Quantitative RTPCR was performed to detect cathepsin gene expression at the transcription level when challenged by B. mori nuclear polyhedrosis virus (BmNPV), temperature and hormones (20-hydroxyecdysone (20E) and juvenile hormone analogue (JHA)). mRNAs encoding cathepsins B and D were significantly enhanced after the larvae were infected with BmNPV, and the peak of the induction appeared at 1 day before spinning. This attenuated the inducing effect on cathepsin expression caused by infection. Temperature shock induced cathepsin expression at the later stage of the 5th instar, and transcription levels varied with development stage and temperature. Cathepsin B and D mRNA expression in the fat body were significantly induced by JHA at the day before spinning, and with 20E, the expression reached a peak at the last day of the 5th instar. Cathepsin B and D mRNA expression exhibited detectable changes post-treatment, without significant differences between or among the hormone concentrations.

Notes : Radical Scavenging Hydroxyphenyl Ethanoic Acid Derivatives from a Marine-Derived Fungus

( Xi Feng Li ),( Se Kwon Kim ),( Jung Sook Kang ),( Hong Dae Choi ),( Byeng Wha Son ) 한국미생물 · 생명공학회 2006 Journal of microbiology and biotechnology Vol.16 No.4

Relationship between Fractional Exhaled Nitric Oxide Level and Efficacy of Inhaled Corticosteroid in Asthma-COPD Overlap Syndrome Patients with Different Disease Severity

Jia-Xi Feng,Yun Lin,Jian Lin,Su-Su He,Mei-Fang Chen,Xiao-Mai Wu,You-Zu Xu 대한의학회 2017 Journal of Korean medical science Vol.32 No.3

This study explored the relationship between the fractional exhaled nitric oxide (FeNO) level and the efficacy of inhaled corticosteroid (ICS) in asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) patients with different disease severity. A total of 127 ACOS patients with ACOS (case group) and 131 healthy people (control group) were enrolled in this study. Based on the severity of COPD, the ACOS patients were divided into: mild ACOS; moderate ACOS; severe ACOS; and extremely severe ACOS groups. We compared FeNO levels, pulmonary function parameters including percentage of forced expiratory volume in 1 second (FEV1) to predicted value (FEV1%pred), ratio of FEV1 to forced vital capacity (FEV1/FVC), inspiratory capacity to total lung capacity (IC/TLC) and residual volume to total lung capacity (RV/TLC), arterial blood gas parameters, including PH, arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2), total serum immunoglobulin E (IgE), induced sputum eosinophil (EOS), plasma surfactant protein A (SP-A), plasma soluble receptor for advanced glycation end products (sRAGE), sputum myeloperoxidase (MPO), sputum neutrophil gelatinase-associated lipocalin (NGAL) and Asthma Control Test (ACT) scores, and COPD Assessment Test (CAT) scores. Compared with pre-treatment parameters, the FeNO levels, RV/TLC, PaCO2, total serum IgE, induced sputum EOS, plasma SP-A, sputum MPO, sputum NGAL, and CAT scores were significantly decreased after 6 months of ICS treatment, while FEV1%pred, FEV1/FVC, IC/TLC, PH, PaO2, plasma sRAGE, and ACT scores were significantly increased in ACOS patients with different disease severity after 6 months of ICS treatment. This finding suggests that the FeNO level may accurately predict the efficacy of ICS in the treatment of ACOS patients.

Assessment of the Severity of Coronavirus Disease: Quantitative Computed Tomography Parameters versus Semiquantitative Visual Score

Yin Xi,Min Xiangde,Nan Yan,Feng Zhaoyan,Li Basen,Cai Wei,Xi Xiaoqing,Wang Liang 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.8

Objective: To compare the accuracies of quantitative computed tomography (CT) parameters and semiquantitative visual score in evaluating clinical classification of severity of coronavirus disease (COVID-19). Materials and Methods: We retrospectively enrolled 187 patients with COVID-19 treated at Tongji Hospital of Tongji Medical College from February 15, 2020, to February 29, 2020. Demographic data, imaging characteristics, and clinical data were collected, and based on the clinical classification of severity, patients were divided into groups 1 (mild) and 2 (severe/ critical). A semiquantitative visual score was used to estimate the lesion extent. A three-dimensional slicer was used to precisely quantify the volume and CT value of the lung and lesions. Correlation coefficients of the quantitative CT parameters, semiquantitative visual score, and clinical classification were calculated using Spearman’s correlation. A receiver operating characteristic curve was used to compare the accuracies of quantitative and semi-quantitative methods. Results: There were 59 patients in group 1 and 128 patients in group 2. The mean age and sex distribution of the two groups were not significantly different. The lesions were primarily located in the subpleural area. Compared to group 1, group 2 had larger values for all volume-dependent parameters (p < 0.001). The percentage of lesions had the strongest correlation with disease severity with a correlation coefficient of 0.495. In comparison, the correlation coefficient of semiquantitative score was 0.349. To classify the severity of COVID-19, area under the curve of the percentage of lesions was the highest (0.807; 95% confidence interval, 0.744–0.861: p < 0.001) and that of the quantitative CT parameters was significantly higher than that of the semiquantitative visual score (p = 0.001). Conclusion: The classification accuracy of quantitative CT parameters was significantly superior to that of semiquantitative visual score in terms of evaluating the severity of COVID-19.

Silver nanoparticles cause complications in pregnant mice

Zhang, Xi-Feng,Park, Jung-Hyun,Choi, Yun-Jung,Kang, Min-Hee,Gurunathan, Sangiliyandi,Kim, Jin-Hoi Dove Medical Press 2015 INTERNATIONAL JOURNAL OF NANOMEDICINE Vol.10 No.-

<P><B>Background</B></P><P>Silver nanoparticles (AgNPs) have attracted much interest and have been used for antibacterial, antifungal, anticancer, and antiangiogenic applications because of their unique properties. The increased usage of AgNPs leads to a potential hazard to human health. However, the potential effects of AgNPs on animal models are not clear. This study was designed to investigate the potential impact of AgNPs on pregnant mice.</P><P><B>Methods</B></P><P>The synthesis of AgNPs was performed using culture extracts of <I>Bacillus cereus</I>. The synthesized AgNPs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy. AgNPs were administrated into pregnant mice via intravenous infusion at 1.0 mg/kg doses at 6.5 days postcoitum (dpc). At 13.5, 15.5, and 17.5 dpc, the pregnant mice were euthanized, and the embryo and placenta were isolated. The meiotic status of oocytes was evaluated. DNA methylation studies were performed, and aberrant imprinting disrupted fetal, placental, and postnatal development. Quantitative real-time polymerase chain reaction analysis and Western blot were used to analyze various gene expressions.</P><P><B>Results</B></P><P>The synthesized AgNPs were uniformly distributed and were spherical in shape with an average size of 8 nm. AgNPs exposure increased the meiotic progression of female germ cells in the fetal mouse ovaries, and maternal AgNP exposure significantly disrupted imprinted gene expression in 15.5 dpc embryos and placentas, such as <I>Ascl2</I>, <I>Snrpn</I>, <I>Kcnq1ot1</I>, <I>Peg3</I>, <I>Zac1</I>, <I>H19</I>, <I>Igf2r</I>, and <I>Igf2</I>; DNA methylation studies revealed that AgNPs exposure significantly altered the methylation levels of differentially methylated regions of <I>Zac1</I>.</P><P><B>Conclusion</B></P><P>The results from this study indicated that early exposure to AgNPs has the potential to disrupt fetal and postnatal health through epigenetic changes in the embryo and abnormal development of the placenta. These results can contribute to research involved in the safe use of various biomedical applications of AgNPs and improves the understanding of the development of AgNPs in biomedical applications.</P>

Differential nanoreprotoxicity of silver nanoparticles in male somatic cells and spermatogonial stem cells

Zhang, Xi-Feng,Choi, Yun-Jung,Han, Jae Woong,Kim, Eunsu,Park, Jung Hyun,Gurunathan, Sangiliyandi,Kim, Jin-Hoi Dove Medical Press 2015 INTERNATIONAL JOURNAL OF NANOMEDICINE Vol.10 No.-

<P><B>Background</B></P><P>Silver nanoparticles (AgNPs) possess unique physical, chemical, and biological properties. AgNPs have been increasingly used as anticancer, antiangiogenic, and antibacterial agents for the treatment of bacterial infections in open wounds as well as in ointments, bandages, and wound dressings. The present study aimed to investigate the effects of two different sizes of AgNPs (10 nm and 20 nm) in male somatic Leydig (TM3) and Sertoli (TM4) cells and spermatogonial stem cells (SSCs).</P><P><B>Methods</B></P><P>Here, we demonstrate a green and simple method for the synthesis of AgNPs using <I>Bacillus cereus</I> culture supernatants. The synthesized AgNPs were characterized using ultraviolet and visible absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy (TEM). The toxicity of the synthesized AgNPs was evaluated by the effects on cell viability, metabolic activity, oxidative stress, apoptosis, and expression of genes encoding steroidogenic and tight junction proteins.</P><P><B>Results</B></P><P>AgNPs inhibited the viability and proliferation of TM3 and TM4 cells in a dose- and size-dependent manner by damaging cell membranes and inducing the generation of reactive oxygen species, which in turn affected SSC growth on TM3 and TM4 as feeder cells. Small AgNPs (10 nm) were more cytotoxic than medium-sized nanoparticles (20 nm). TEM revealed the presence of AgNPs in the cell cytoplasm and nucleus, and detected mitochondrial damage and enhanced formation of autosomes and autolysosomes in the AgNP-treated cells. Flow cytometry analysis using Annexin V/propidium iodide staining showed massive cell death by apoptosis or necrosis. Real-time polymerase chain reaction and western blot analyses indicated that in TM3 and TM4 cells, AgNPs activated the p53, p38, and pErk1/2 signaling pathways and significantly downregulated the expression of genes related to testosterone synthesis (TM3) and tight junctions (TM4). Furthermore, the exposure of TM3 and TM4 cells to AgNPs inhibited proliferation and self-renewal of SSCs.</P><P><B>Conclusion</B></P><P>Our results suggest that AgNPs exhibit size-dependent nanoreprotoxicity in male somatic cells and SSCs, strongly suggesting that applications of AgNPs in commercial products must be carefully evaluated. Further studies of AgNPs-induced nanoreprotoxicity in animal models are required.</P>

해양균류의 Tyrosinase 저해활성 검색

Li Xi-Feng 한국생약학회 2003 생약학회지 Vol.34 No.2