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      • KCI등재

        Cloning of gonadal aromatase gene Cyp19a in an endemic fish (Schizothorax kozlovi) of the Upper Yangtze River, and temperature effects on its expression

        De-guo Yang,Yong-feng He,Xing-bing Wu,Yong-jiu Zhu 한국유전학회 2016 Genes & Genomics Vol.38 No.9

        In order to elucidate the role of Cyp19a in sex differentiation of Schizothorax kozlovi, the full length cDNA of Cyp19a was cloned from the mature ovary of S. kozlovi by using rapid amplification of cDNA ends method, and then its relative mRNA expression levels among tissues and temperature groups were determined by using quantitative real-time PCR. The complete Cyp19a cDNA of 1795 bp of S. kozlovi was obtained, which encoded 517 amino acids and belonged to gonadal aromatase. Its deduced amino acid sequence had the above 70 % identity compared with gonadal aromatase genes of teleost fishes, but only 62–67 % when compared with brain aromatase genes of fishes. It was expressed only in heart and gonad, but no expression in other tissues, presenting relatively high tissue specificity. It also exhibited sex-specific expression pattern in gonads, but no sex differences in heart. Comparing with the Cyp19a expression levels at 12 days post hatching (dph), significant temperature effects were revealed in low temperature group (10 C) at 18 dph, and in high temperature group (26 C) at 40 dph. It suggested that gonadal aromatase Cyp19a gene may play important roles on the feminization or masculinization of S. kozlovi affected by temperature during the early developmental stage.

      • KCI등재

        Impact performance for high frequency hydraulic rock drill drifter with sleeve valve

        Guo, Yong,Yang, Shu Yi,Liu, De Shun,Zhang, Long Yan,Chen, Jian Wen Korean Society for Fluid machinery 2016 International journal of fluid machinery and syste Vol.9 No.1

        A high frequency hydraulic rock drill drifter with sleeve valve is developed to use on arm of excavator. In order to ensure optimal working parameters of impact system for the new hydraulic rock drill drifter controlled by sleeve valve, the performance test system is built using the arm and the hydraulic source of excavator. The evaluation indexes are gained through measurement of working pressure, supply oil flow and stress wave. The relations of working parameters to impact system performance are analyzed. The result demonstrates that the maximum impact energy of the drill drifter is 98.34J with impact frequency of 71HZ. Optimal pressure of YZ45 rock drill is 12.8 MPa-13.6MPa, in which the energy efficiency reaches above 58.6%, and feature moment of energy distribution is more than 0.650.

      • Study in the Mechanisms of Formation of Transfer Film under the Condition of Wear of Steel AISI1020 by Natural Rubber

        DE-GUO WANG,SI-WEI ZHANG,REN-YANG HE,MING-YUAN LI 한국트라이볼로지학회 2002 한국트라이볼로지학회 학술대회 Vol.2002 No.10

        The mechanisms of formation of transfer film under the condition of wear of Steel AISI1020 by natural rubber were investigated. The transfer film was observed and the formation mechanisms were clarified. The formation process of transfer film on the worn surface of the steel could be divided into two stages. Firstly, the adhesive layer emerged on the worn surface of the steel by adhesion of natural rubber, in which the macromolecular chains of natural rubber joined to the surface of the steel by Van der Waals' force. And then, the iron atom and metal oxide reacted with the macroradicals of natural rubber in the adhesive layer and produced Fe-polymer compound. As a result, the transfer film was formed on the worn surface of the steel. The transfer film was joined to the worn surface of the steel by the chemical bonds and electrostatic force.

      • KCI등재

        Risk Factors for Pulmonary Cement Embolism (PCE) After Polymethylmethacrylate Augmentation: Analysis of 32 PCE Cases

        Huizhi Guo,Huasheng Huang,Yang Shao,Qiuli Qin,De Liang,Shuncong Zhang,Yongchao Tang 대한척추신경외과학회 2021 Neurospine Vol.18 No.4

        Objective: Pulmonary cement embolism (PCE) is an underestimated but potentially fatal complication after cement augmentation. Although the treatment and follow-up of PCE have been reported in the literature, the risk factors for PCE are so far less investigated. This study aims to identify the preoperative and intraoperative risk factors for the development of PCE. Methods: A total of 1,373 patients treated with the polymethylmethacrylate (PMMA) augmentation technique were retrospectively included. Patients with PCE were divided into vertebral augmentation group and screw augmentation group. Possible risk factors were collected as follows: age, sex, bone mineral density, body mass index, diagnosis, comorbidity, surgical procedure, type of screw, augmented level, number of augmented vertebrae, fracture severity, presence of intravertebral cleft, cement volume, marked leakage in the paravertebral venous plexus, and periods of surgery. Binary logistic regression analyses were used to analyze independent risk factors for PCE. Results: PCE was identified in 32 patients, with an incidence rate of 2.33% (32 of 1,373). For patients who had undergone vertebral augmentation, marked leakage in the paravertebral venous plexus (odds ratio [OR], 1.2; 95% confidence interval [CI], 0.1–10.3; p=0.000) and previous surgery (OR, 16.1; 95% CI, 4.2–61.0; p=0.007) were independent risk factors for PCE. Regarding patients who had undergone screw augmentation, the marked leakage in the paravertebral venous plexus (OR, 4.2; 95% CI, 0.5–37.3; p=0.004) was the main risk factor. Conclusion: Marked leakage in the paravertebral venous plexus and previous surgery were significant risk factors related to PCE. Paravertebral leakage and operator experience should be concerned when performing PMMA augmentation.

      • KCI등재

        Efficacy and Safety of Intravenous Urapidil for Older Hypertensive Patients with Acute Heart Failure: A Multicenter Randomized Controlled Trial

        Wei Yang,Qi Hua,Yu-Jie Zhou,Yan Fu,Jian Qin,Shu Qin,Xiao-Min Chen,Jin-Cheng Guo,De-Zhao Wang,Hong Zhan,Jing Li,Jing-Yu He 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.1

        Purpose: Urapidil is putatively effective for patients with hypertension and acute heart failure, although randomized controlled trials thereon are lacking. We investigated the efficacy and safety of intravenous urapidil relative to that of nitroglycerin in older patients with hypertension and heart failure in a randomized controlled trial. Materials and Methods: Patients (>60 y) with hypertension and heart failure were randomly assigned to receive intravenous urapidil (n=89) or nitroglycerin (n=91) for 7 days. Hemodynamic parameters, cardiac function, and safety outcomes were compared. Results: Patients in the urapidil group had significantly lower mean systolic blood pressure (110.1±6.5 mm Hg) than those given nitroglycerin (126.4±8.1 mm Hg, p=0.022), without changes in heart rate. Urapidil was associated with improved cardiac function as reflected by lower N terminal-pro B type natriuretic peptide after 7 days (3311.4±546.1 ng/mL vs. 4879.1±325.7 ng/mL, p=0.027) and improved left ventricular ejection fraction (62.2±3.4% vs. 51.0±2.4%, p=0.032). Patients given urapidil had fewer associatedadverse events, specifically headache (p=0.025) and tachycardia (p=0.004). The one-month rehospitalization and all-cause mortality rates were similar. Conclusion: Intravenous administration of urapidil, compared with nitroglycerin, was associated with better control of blood pressure and preserved cardiac function, as well as fewer adverse events, for elderly patients with hypertension and acute heart failure.

      • KCI등재

        아드만탄 기반의 새로운 설포네이트 폴리카보네이트 난연제 성능 연구

        Jian Wei Guo,Yue Qin Wang,Li Juan Feng,Xing Zhong,Chu Fen Yang,Sa Liu,Ying De Cui 한국고분자학회 2013 폴리머 Vol.37 No.4

        A novel sulfonate flame retardant, 1,3,5,7-tetrakis(phenyl-4-sodium sulfonate)adamantane (FR-A), was suc-cessfully synthesized from l-bromoadamantane in sequential four-step reactions involving Fiedel-Crafts phenylation, sul-phonation, hydrolysis, and neutralization. The success of synthesis was confirmed by FTIR spectra, ‘H NMR spectra, elemental analyses and mass spectra. The effect of FR-A on the flame retardacy of polycarbonate (PC) has been studied. Limiting oxygen index (LOI) and thermogravimetric analysis (TGA) showed that this novel sulfonate flame retardant had effective flame retardancy on polycarbonate (PC). With a small amount (0.08 Wt%) of FR-A. the flame retardancy of PC was improved obviously, which got to UL 94 V-0 rating. TGA and DTA curves demonstrated that the additive raised the degradation rate of PC by promoting the quick formation of an insulating carbon layer on the surface, and confirmed that the flame retardant mechanism of PC/FR-A system was similar to potassium diphenylsulfone sulfonate (KSS).

      • SCIESCOPUSKCI등재

        Antioxidant activity of ginseng cultivated under mountainous forest with different growing years

        Pan, Hong-Yan,Qu, Yang,Zhang, Jian-Kui,Kang, Ting-Guo,Dou, De-Qiang The Korean Society of Ginseng 2013 Journal of Ginseng Research Vol.37 No.3

        Ginseng cultivated and grown naturally under mountainous forest is formally called "Lin-Xia-Shan-Shen" (LXSS) and grown in manual condition is called garden ginseng (GG) according to Chinese pharmacopoeia (2010 edition). Usually the growing condition of LXSS is similar to wild ginseng and mostly used in Chinese folks in ancient times. The antioxidant properties of LXSS with different growing years were evaluated by their inhibitions of thiobarbituric acid-reactive substance (TBA-RS) formation in liver homogenate and 2, 2-diphenyl-1-picrylhydrazyl (DPPH)-radical scavenging activity comparing with those of GG. The inhibitions of different polar extracts (n-butanol and water) of LXSS and GG on TBA-RS formation were also evaluated. The results showed that the antioxidant effects of LXSS were higher than those of GG and the TBA-RS formation inhibition of LXSS with longer growing years were stronger than those with shorter growing years, while the DPPH-radical scavenging activity of LXSS did not show significant difference with the change of the growing year. The results indicated that the inhibitory effect of TBA-RS formation and the DPPH-radical scavenging of LXSS were correlated with the contents of ginsenosides. In adddition, the starch contents of LXSS and GG were determined by micro-amount method with spectrophotometer. It showed that the starch content in GG was higher than that of LXSS whose starch decreased gradually with the growing year.

      • KCI등재

        Antioxidant activity of ginseng cultivated under mountainous forest with different growing years

        Hong-Yan Pan,Yang Qu,Jian-Kui Zhang,Ting-Guo Kang,De-Qiang Dou 고려인삼학회 2013 Journal of Ginseng Research Vol.37 No.3

        Ginseng cultivated and grown naturally under mountainous forest is formally called “Lin-Xia-Shan-Shen” (LXSS) and grown in manual condition is called garden ginseng (GG) according to Chinese pharmacopoeia (2010 edition). Usually the growing condition of LXSS is similar to wild ginseng and mostly used in Chinese folks in ancient times. The antioxidant properties of LXSS with different growing years were evaluated by their inhibitions of thiobarbituric acid-reactive substance (TBA-RS) formation in liver homogenate and 2, 2-diphenyl-1-picrylhydrazyl (DPPH)-radical scavenging activity comparing with those of GG. The inhibitions of different polar extracts (n-butanol and water) of LXSS and GG on TBA-RS formation were also evaluated. The results showed that the antioxidant effects of LXSS were higher than those of GG and the TBARS formation inhibition of LXSS with longer growing years were stronger than those with shorter growing years, while the DPPH-radical scavenging activity of LXSS did not show significant difference with the change of the growing year. The results indicated that the inhibitory effect of TBA-RS formation and the DPPH-radical scavenging of LXSS were correlated with the contents of ginsenosides. In adddition, the starch contents of LXSS and GG were determined by micro-amount method with spectrophotometer. It showed that the starch content in GG was higher than that of LXSS whose starch decreased gradually with the growing year.

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