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      • KCI등재후보

        UNUSUAL ELECTROCHEMICAL RESPONSE OF ELECTROCHEMICAL ETCHING ON MULTIWALLED CARBON NANOTUBES

        JIAN-SHAN YE,GUANGQUAN MO,WEI DE ZHANG,XIAO LIU,FWU-SHAN SHEU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2008 NANO Vol.3 No.6

        Multiwalled carbon nanotubes (MWNTs) can be etched at potentials more positive than 1.7 V versus Ag/AgCl (3 M KCl) in 0.2 M HNO3. The electrochemically etched MWNTs show an increase in electrochemical impedance and sluggish electron transfer kinetics, and lose the electrocatalytic effects toward the oxidation of glucose, H2O2, uric acid (UA) and L-ascorbic acid (L-AA). Transmission electron microscope (TEM) images reveal that the nanotube tips are cut off by electrochemical oxidation. This may lead to the degradation of electrocatalytic ability in the MWNTs. Furthermore, the current response after different electrochemically etched cycles shows that the electrocatalytic ability of the MWNTs toward different molecules can be tuned by etched cycles. For example, five etched cycles leads to the total disappearance of the oxidative response to L-AA, with the remaining over 50% of the UA current response in the L-AA and UA mixture. Thus, electrochemical etching is a simple yet novel way to tune the electrocatalytic reactivity and improve the selectivity of the MWNTs.

      • Antifibrotic Effect of Curcumin in TGF-β1-Induced Myofibroblasts from Human Oral Mucosa

        Zhang, Shan-Shan,Gong, Zhao-Jian,Li, Wen-Hui,Wang, Xiao,Ling, Tian-You Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

        Background: Myofibroblasts play an important role in the development of oral submucous fibrosis (OSF). In the current study, we investigate the effect of curcumin on growth and apoptosis of myofibroblasts derived from human oral mucosa. Methods: Myofibroblasts were generated by incubating fibroblasts, obtained from human oral mucosa, with transforming growth factor-${\beta}1$ (TGF-${\beta}1$). MTT, PI staining, and FACS assays were used to investigate curcumin's effect on proliferation and cell cycle of fibroblasts and myofibroblasts. Annexin V/PI binding and FACS assays were used to examine apoptosis of myofibroblasts, Western blotting to determine the levels of Bcl-2 and Bax, and enzyme-linked immunosorbant assay was employed to examine the levels of collagen type I and III in the supernatants of myofibroblasts. Results: Curcumin inhibits proliferation of fibroblasts and myofibroblasts; it also disturbs the cell cycle, induces apoptosis and decreases the generation of collagen type I and III in myofibroblasts, which are more sensitive to its effects than fibroblasts. Curcumin induces apoptosis in myofibroblasts by down-regulating the Bcl-2/ Bax ratio. Conclusion: Our results demonstrate the antifibrotic effect of curcumin in vitro. It may therefore be a candidate for the treatment of OSF.

      • SCIESCOPUSKCI등재
      • An Updated Meta-analysis Between the Association of XRCC1 Arg399Gln Polymorphism and Hepatocellular Carcinoma Risk

        Zhang, Xiao-Lian,Lu, Yu,Yang, Shi,Peng, Qi-Liu,Wang, Jian,Xie, Li,Deng, Yan,He, Yu,Li, Tai-Jie,Qin, Xue,Li, Shan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.7

        Background: Various studies have evaluated the relationship between X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism and hepatocellular carcinoma (HCC) risk, but the conclusions have been inconsistent and underpowered. The purpose of this updated meta-analysis was to examine whether XRCC1 Arg399Gln polymorphism confers susceptibility to HCC. Methods: Eligible studies extracted from PubMed, Embase, Cochrane Library, VIP (chinese) and CNKI (chinese) up to November 2013 were included in the study. Pooled odds ratio (OR) together with their 95% confidence interval (CI) were estimated to evaluate XRCC1 Arg399Gln polymorphism and HCC risk. Results: Finally, 21 studies with 4,170 cases and 5,030 controls were involved in our meta-analysis. The results demonstrated that there was significant association between Arg399Gln polymorphism and HCC risk under two contrast models in overall populations (AG vs GG: OR=1.265, 95%CI=1.036-1.545, p=0.021; AA+AG vs GG: OR=1.240, 95%CI=1.021-1.506, p=0.030). In subgroup analyses, significant association was found in Asians (A vs G: OR=1.175, 95%CI=1.013-1.362, p=0.033; AG vs GG: OR=1.317, 95%CI=1.070-1.622, p=0.009; AA+AG vs GG: OR=1.289, 95%CI=1.055-1.575, p=0.013) and Caucasians (A vs G: OR=0.591, 95%CI=0.361-0.966, p=0.036; AA+AG vs GG: OR=0.468, 95%CI=0.234-0.934, p=0.031). Conclusions: The results suggest that XRCC1 Arg399Gln polymorphism may increase HCC risk especially among Asians. However, XRCC1 Arg399Gln polymorphism might act as a protective role against HCC among Caucasians.

      • KCI등재

        Novel 5-Fluorouracil Derivatives: Synthesis and Cytotoxic Activity of 2-Butoxy-4-Substituted 5-Fluoropyrimidines

        Jian Sun,Shi-Jie Zhang,Hai-Bo Li,Wei Zhou,Wei-Xiao Hu,Shang Shan 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.5

        Twenty two new 5-fluorouracil (5-FU) derivatives, 2-butoxy-4-substituted 5-fluoropyrimidines, were synthesized and characterized by IR, 1H NMR, MS, HRMS. All compounds were preliminarily evaluated by MTT assay on human liver BEL-7402 cancer cell line in vitro. Ten compounds were selected to test their cytotoxic activity against A549, HL-60 and MCF-7 cancer cell lines in vitro. These compounds were more sensitive to BEL-7402 than other cell lines, particularly, cytotoxic activity of compounds 6b, 6d-f, 6p, 6s-u were in sub-micromolar scale. The highest cytotoxic potency against A549, HL-60 and MCF-7 was shown by 2-butoxy-4-chloro-5- fluoropyrimidine (5) with IC50 values of 0.10, 1.66 and 0.59 μM, respectively. Compounds 6d and 6e were effective against MCF-7 with IC50 9.73 μM and HL-60 with IC50 8.83 μM, respectively.

      • Performance of the R-way Colposcopic Evaluation System in Cervical Cancer Screening

        Zhao, Jian,Zhang, Xi,Chen, Rui,Zhao, Yu-Qian,Wang, Ting-Ting,He, Shan,Qiao, You-Lin Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.10

        Objective: To investigate the diagnostic value of the R-way colposcopic evaluation system (R-way system) in cervical cancer screening. Materials and Methods: Between August 2013 and August 2014, a total of 1,059 cases referred to colposcopy in Peking University First Hospital were studied using both the R-way system and conventional colposcopy. Our study evaluated and compared the diagnostic ability of the two methods in detecting high-grade lesions and cervical cancer (hereinafter called CIN2+). Evaluation indicators including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), Youden index and the area under the curve (AUC) of the receiver operating characteristic (ROC) were calculated. Results: The R-way system had a slightly lower specificity (94.5%) than conventional colposcopy (96.0%) for CIN2+ detection (P=0.181). However, the sensitivity (77.8%) was significantly higher than with the conventional colposcopic method (46.6%) (${\chi}^2=64.351$, P<0.001). In addition, the AUC of the ROC for CIN2+ detection using the R-way system (0.839) was larger than that with conventional colposcopy (0.731) (Z=4.348, P<0.001). If preliminary result had been drawn from cervical exfoliated cytology before colposcopy referral, combination of the R-way system with cytology could increase the sensitivity to 93.9% for CIN2+ detection (excluding ASCUS\LSIL), confirmed by multipoint biopsy or ECC. Conclusions: The diagnostic value of the R-way evaluation system is higher than that of conventional colposcopic evaluation in cervical cancer screening. Moreover, taking the ease of use and standardized quality control management into account, the R-way system is highly preferable.

      • Characteristics of Mammary Paget's Disease in China: a National-wide Multicenter Retrospective Study During 1999-2008

        Zheng, Shan,Song, Qing-Kun,Zhao, Lin,Huang, Rong,Sun, Li,Li, Jing,Fan, Jin-Hu,Zhang, Bao-Ning,Yang, Hong-Jian,Xu, Feng,Zhang, Bin,Qiao, You-Lin Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

        The aim of this study was to detail characteristics of mammary Paget's disease (PD) representing the whole population in China. A total of 4211 female breast cancer inpatients at seven tertiary hospitals from seven representative geographical regions of China were collected randomly during 1999 to 2008. Data for demography, risk factors, diagnostic imaging test, physical examination and pathologic characters were surveyed and biomarker status was tested by immunohistochemistry. The differences of demography and risk factors between PD with breast cancer and other lesions were compared using Chi-square test or t-test, with attention to physical examination and pathological characters. The percentage of PD was 1.6% (68/4211) in all breast cancers. The mean age at diagnosis was 48.1, and 63.2% (43/68) patients were premenopausal. There is no difference in demography and risk factors between PD with breast cancer and other breast cancer (P > 0.05). The main pattern of PD in physical exam and pathologic pattern were patients presenting with a palpable mass in breast (65/68, 95.6%) and PD with underlying invasive cancer (82.4%, 56/68) respectively. The rate of multifocal disease was 7.4% (5/68). PD with invasive breast cancer showed larger tumor size, more multifocal disease, lower ER and PR expression and higher HER2 overexpression than those in other invasive breast cancer (P < 0.05). These results suggested that PD in China is a concomitant disease of breast cancer, and that PD with underlying invasive cancer has more multiple foci and more aggressive behavior compared with other breast invasive cancer. We address the urgent needs for establishing diagnostic and therapeutic guidelines for mammary PD in China.

      • SCOPUSKCI등재

        Novel 5-Fluorouracil Derivatives: Synthesis and Cytotoxic Activity of 2-Butoxy-4-Substituted 5-Fluoropyrimidines

        Sun, Jian,Zhang, Shi-Jie,Li, Hai-Bo,Zhou, Wei,Hu, Wei-Xiao,Shan, Shang Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.5

        Twenty two new 5-fluorouracil (5-FU) derivatives, 2-butoxy-4-substituted 5-fluoropyrimidines, were synthesized and characterized by IR, $^1H$ NMR, MS, HRMS. All compounds were preliminarily evaluated by MTT assay on human liver BEL-7402 cancer cell line in vitro. Ten compounds were selected to test their cytotoxic activity against A549, HL-60 and MCF-7 cancer cell lines in vitro. These compounds were more sensitive to BEL-7402 than other cell lines, particularly, cytotoxic activity of compounds 6b, 6d-f, 6p, 6s-u were in sub-micromolar scale. The highest cytotoxic potency against A549, HL-60 and MCF-7 was shown by 2-butoxy-4-chloro-5-fluoropyrimidine (5) with $IC_{50}$ values of 0.10, 1.66 and $0.59{\mu}M$, respectively. Compounds 6d and 6e were effective against MCF-7 with $IC_{50}$ $9.73{\mu}M$ and HL-60 with $IC_{50}$ $8.83{\mu}M$, respectively.

      • C1420T Polymorphism of Cytosolic Serine Hydroxymethyltransferase and Risk of Cancer: a Meta-analysis

        Zhong, Shan-Liang,Zhang, Jun,Hu, Qing,Chen, Wei-Xian,Ma, Teng-Fei,Zhao, Jian-Hua Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.5

        A series of studies have explored the role of cytosolic serine hydroxymethyltransferase (SHMT1) C1420T polymorphism in cancer risk, but their results were conflicting rather than conclusive. To derive a more precise estimation of the association between C1420T and cancer risk, the present meta-analysis of 28 available studies with 15,121 cases and 18,023 controls was conducted. The results revealed that there was no significant association between the polymorphism and cancer risk overall. In stratified analysis by cancer type (breast cancer, gastrointestinal cancer, leukemia, lymphoma, and others), the results showed that 1420T allele was associated with decreased risk in leukemia (CT vs. CC: OR= 0.825, 95% CI =0.704-0.966; and CT+TT vs. CC: OR= 0.838, 95% CI = 0.722-0.973), but the same results were not present for other cancer types. When subgroup analysis was performed by source of control (population-based [PB] and hospital-based [HB]), a borderline inverse association was observed for the HB subgroup (CT vs. CC: OR= 0.917, 95% CI = 0.857-0.982) but not for the PB subgroup. Stratifying by geographic area (America, Asia and Europe), significant inverse association was only found in Asia subgroup (CT vs. CC: OR= 0.674, 95% CI = 0.522-0.870). In summary, the findings suggest that SHMT1 C1420T polymorphism is not associated with overall cancer development, but might decrease cancer susceptibility of Asians as well as reduce leukemia risk. Large well-designed epidemiological studies will be necessary to validate the risk identified in the current meta-analysis.

      • KCI등재

        Cubic Spline Trajectory Generation with Axis Jerk and Tracking Error Constraints

        Ke Zhang,Jian-Xin Guo,Xiao-Shan Gao 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

        This paper presents a cubic spline trajectory generation algorithm that produces continuous position, velocity, and acceleration profiles for CNC machines with confined axis jerk and tracking error. A series of reference knots are connected using cubic spline functions in time t for constructing axis trajectories. They are generated in such a way that continuity up to the second derivative is preserved along the overall composite curve. For CNC machines governed by a typical PID controller, the tracking error is also constrained as well as the velocity, acceleration, and jerk for each axis. The time intervals between each pair of adjacent knots are scheduled such that the machining time is minimized subject to all the constraints. Experiment results are presented to illustrate the application of the algorithm.

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