• 제목/요약/키워드: Wei Qi

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An Improved Active Damping Method with Capacitor Current Feedback

  • Geng, Yi-Wen;Qi, Ya-Wen;Liu, Hai-Wei;Guo, Fei;Zheng, Peng-Fei;Li, Yong-Gang;Dong, Wen-Ming
    • Journal of Power Electronics
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    • v.18 no.2
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    • pp.511-521
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    • 2018
  • Proportional capacitor current feedback active damping (CCFAD) has a limited valid damping region in the discrete time domain as (0, $f_s/6$. However, the resonance frequency ($f_r$) of an LCL-type filter is usually designed to be less than half the sampling frequency ($f_s$) with the symmetry regular sampling method. Therefore, ($f_s/6$, $f_s/2$) becomes an invalid damping region. This paper proposes an improved CCFAD method to extend the valid damping region from (0, $f_s/6$ to (0, $f_s/2$), which covers all of the possible resonance frequencies in the design procedure. The full-valid damping region is obtained and the stability margin of the system is analyzed in the discrete time domain with the Nyquist criterion. Results show that the system can operate stably with the proposed CCFAD method when the resonance frequency is in the region (0, $f_s/2$). The performances at the steady and dynamic state are enhanced by the selected feedback coefficient H and controller gain $K_p$. Finally, the feasibility and effectiveness of the proposed CCFAD method are verified by simulation and experimental results.

Structural Maintenance of Chromosomes 4 is a Predictor of Survival and a Novel Therapeutic Target in Colorectal Cancer

  • Feng, Xiao-Dong;Song, Qi;Li, Chuan-Wei;Chen, Jian;Tang, Hua-Mei;Peng, Zhi-Hai;Wang, Xue-Chun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9459-9465
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    • 2014
  • Background: Structural maintenance of chromosomes 4 (SMC-4) is a chromosomal ATPase which plays an important role in regulate chromosome assembly and segregation. However, the role of SMC-4 in the incidence of malignancies, especially colorectal cancer is still poorly understood. Materials and Methods: We here used quantitative PCR and Western blot analysis to examine SMC-4 mRNA and protein levels in primary colorectal cancer and paired normal colonic mucosa. SMC-4 clinicopathological significance was assessed by immunohistochemical staining in a tissue microarray (TMA) in which 118 cases of primary colorectal cancer were paired with noncancerous tissue. The biological function of SMC-4 knockdown was measured by CCK8 and plate colony formation assays. Fluorescence detection has been used to detect cell cycling and apoptosis. Results: SMC-4 expression was significantly higher in colorectal cancer and associated with T stage, N stage, AJCC stage and differentiation. Knockdown of SMC-4 expression significantly suppressed the proliferation of cancer cells and degraded its malignant degree. Conclusions: Our clinical and experimental data suggest that SMC-4 may contribute to the progression of colorectal carcinogenesis. Our study provides a new therapeutic target for colorectal cancer treatment.

Etoposide-Cisplatin Alternating with Vinorelbine-Cisplatin Versus Etoposide-Cisplatin Alone in Patients with Extensive Disease Combined with Small Cell Lung Cancer

  • Zhang, Jie;Qi, Hui-Wei;Zheng, Hui;Chen, Mo;Zhu, Jun;Xie, Hui-Kang;Ni, Jian;Xu, Jian-Fang;Zhou, Cai-Cun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.10
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    • pp.4159-4163
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    • 2014
  • Background: The aim of this study was to evaluate the efficacy of alternating etoposide-cisplatin and vinorelbine-cisplatin (EP-NP) compared with an etoposide-cisplatin (EP) regimen for advanced combined small cell carcinomas. Materials and Methods: Histologically confirmed combined small cell carcinoma patients who met the inclusion criteria were randomly assigned (1:1) into either the EP-NP setting (group A) or the EP setting (group B). The primary endpoint was progression-free survival in patients who received at least one dose of treatment. Results: Eighty-two patients entered into this trial, 42 in group A and 40 in group B. The objective response rates in group A and group B were 42.9% and 32.5%, respectively (p=0.334). Survival analysis showed that median progression-free survival was 6.1 months in group A, which was significantly longer than the 4.1 months in group B (p=0.041). However, as to overall survival, no significant difference was found between the two groups (11.0 vs 10.1 months in groups A and B, respectively, p=0.545). No unexpected side effects were observed in either group. Conclusions: The EP-NP regimen for combined small cell carcinomas prolonged progressio-nfree survival compared with the EP regimen. Further clinical investigations are warranted.

No Association Between Tea Consumption and Risk of Renal Cell Carcinoma: A Meta-analysis of Epidemiological Studies

  • Hu, Zheng-Hui;Lin, Yi-Wei;Xu, Xin;Chen, Hong;Mao, Ye-Qing;Wu, Jian;Xu, Xiang-Lai;Zhu, Yi;Li, Shi-Qi;Zheng, Xiang-Yi;Xie, Li-Ping
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.1691-1695
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    • 2013
  • Objective: To evaluate the association between tea consumption and the risk of renal cell carcinoma. Methods: We searched PubMed, Web of Science and Scopus between 1970 and November 2012. Two evaluators independently reviewed and selected articles based on predetermined selection criteria. Results: Twelve epidemiological studies (ten case-control studies and two cohort studies) were included in the final analysis. In a meta-analysis of all included studies, when compared with the lowest level of tea consumption, the overall relative risk (RR) of renal cell carcinoma for the highest level of tea consumption was 1.03 (95% confidence interval [CI] 0.89-1.21). In subgroup meta-analyses by study design, there was no significant association between tea consumption and renal cell carcinoma risk in ten case-control studies using adjusted data (RR=1.08, 95% CI 0.84-1.40). Furthermore, there was no significant association in two cohort studies using adjusted data (RR=0.95, 95% CI 0.81-1.12). Conclusion: Our findings do not support the conclusion that tea consumption is related to decreased risk of renal cell carcinoma. Further prospective cohort studies are required.

New Triterpenoids from the Fruits of Schisandra wilsoniana and Their Biological Activities

  • Gao, Xue-Mei;Li, Yun-Qi;Shu, Li-Dan;Shen, Yan-Qiong;Yang, Li-Ying;Yang, Liu-Meng;Zheng, Yong-Tang;Sun, Han-Dong;Xiao, Wei-Lie;Hu, Qiu-Fen
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.827-830
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    • 2013
  • Investigation of an organic extract of the fruits Schisandra wilsoniana led to the isolation of two new highly oxygenated nortriterpenoids, named schilancidilactones V-W (1-2). Their structures were elucidated by spectroscopic evidence. Compounds 1-2 feature a double bond between C-7 and C-8 compared with related known nortriterpenoids isolated from the genus Schisandra. Compounds 1 and 2 were tested for their anti-HIV-1 activities and cytotoxicity. The results revealed that compounds 1 and 2 showed moderate anti-HIV-1 activities with $EC_{50}$ 3.05 and 2.87 ${\mu}g/mL$, respectively, and compound 1 showed high cytotoxicity against KB and MDA-MB-231 cell with $IC_{50}$ values of 3.18 and 5.22 ${\mu}M$, respectively.

Experimental investigation of impact-sliding interaction and fretting wear between tubes and anti-vibration bars in steam generators

  • Guo, Kai;Jiang, Naibin;Qi, Huanhuan;Feng, Zhipeng;Wang, Yang;Tan, Wei
    • Nuclear Engineering and Technology
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    • v.52 no.6
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    • pp.1304-1317
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    • 2020
  • The tubes in a heat exchanger, such as a steam generator (SG), are subjected to crossflow, and interaction between tubes and supports can happen, which can cause fretting wear of tubes. Although many experiments and models have been established, some detailed mechanisms are still not sufficiently clear. In this work, more attention is paid to obtain the regulation of impact and sliding in the complex process and many factors, such as excitation forces and clearances. The responses and contact forces were analyzed to obtain clear understanding of the influences of these factors. Room temperature tests in the air were established. The results show that the effect of clearance on the normal work rate is not monotonous and instead has two peaks. The force ratio can influence the normal work rate by changing the distribution of contact angles, which can result in higher sliding in the contact process. Fretting wear tests are conducted, and the wear surfaces are analyzed by a scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDX). The results of this work can serve as a reference for impactsliding contact analysis between AVBs and tubes in steam generators.

A philological Study on Qingwujing(靑烏經) (청오경(靑烏經)의 문헌적 연구)

  • Chang, Sung-Kyu
    • Journal of architectural history
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    • v.18 no.2
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    • pp.27-45
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    • 2009
  • This study was to analyze the philological character of Qingwujing(靑烏經). Qingwujing is the oldest and representative documents of FengShui, especially famous for FengShui XingQi(形氣) theories. In spite of is fame, a systematic research for Qingwujing was not yet fulfilled up to now in Korea. In is the main reason why have to research the philological character of Qingwujing. The results from this research were described as following. Qingwujing(靑烏經) as knows of Qingwujing's writer is very famous already in Han 한(漢) dynasty for his accurate FengShui methods. His FengShui thories getting more powerfyl from WeiChen(魏晉) to Tang(唐) dynasty. In Tang(唐) dynasty Qingwujing was abolished by government rulers, but it recovered and retouched by some scholars from Tang(唐) and Song(宋) dynasty. In the process, the block book of Qingwujing were changed for four or five kinds. Qingwujing's block books of Ming(明) dynasty are Yimenguangdu(夷門廣牘), Xiaoshisanjing(小十三經), Jujiabibei(居家必備), and Shuofu(說郛). It's block books of Qing(淸) dynasty are Gujintushujicheng(古今圖書集成), Sikuquanshu(四庫全書), Xuejintaoyuan(學津討原), and Ershierziquanji(二十二子全集). It's block book of Choson(朝鮮) dynasty is KyujangKak(奎章閣). Among them distinctive characters been founded, but the basic contents and theories are almost same. In Korea, Qingwuzi's FengShui theories were confirmed in Silla(新羅) dynasty, and it recoreded in Soongboksa inscription written by Choi-CheeWon. Qingwu(靑烏) or Qingwuzi were known for a great FengShui master of a FengShui standing theories in Koryeo(高麗) and Choson dynasty among royal families and the aristocratic classes. And Qingwujing was a representative FengShui theory book in wh0.1ole period of Choson dynasty. Now for understanding traditional FengShui theories, we have to understand the main FengShui theories on Choson dynasty at first. For understanding Choson FengShui, the study on philological character of Qingwujing is the basic works. If those works fulfilled successfully, we can understand FengShui theories and FengShu itself more correctly.

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AtHAP3b Plays a Crucial Role in the Regulation of Flowering Time in Arabidopsis during Osmotic Stress

  • Chen, Nai-Zhi;Zhang, Xiu-Qing;Wei, Peng-Cheng;Chen, Qi-Jun;Ren, Fei;Chen, Jia;Wang, Xue-Chen
    • BMB Reports
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    • v.40 no.6
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    • pp.1083-1089
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    • 2007
  • The HAP complex has been found in many eukaryotic organisms. HAP recognizes the CCAAT box present in the promoters of 30% of all eukaryotic genes. The HAP complex consists of three subunits - HAP2, HAP3 and HAP5. In this paper, we report the biological function of the AtHAP3b gene that encodes one of the HAP3 subunits in Arabidopsis. Compared with wild-type plants, hap3b-1 and hap3b-2 mutants exhibited a delayed flowering time under long-day photoperiod conditions. Moreover, the transcription levels of FT were substantially lower in the mutants than in the wild-type plants. These results imply that AtHAP3b may function in the control of flowering time by regulating the expression of FT in Arabidopsis. In a subsequent study, AtHAP3b was found to be induced by osmotic stress. Under osmotic stress conditions, the hap3b- 1 and hap3b-2 mutants flowered considerably later than the wild-type plants. These results suggest that the AtHAP3b gene plays more important roles in the control of flowering under osmotic stress in Arabidopsis.

siRNA-mediated gene silencing of MexB from the MexA-MexB-OprM efflux pump in Pseudomonas aeruginosa

  • Gong, Feng-Yun;Zhang, Ding-Yu;Zhang, Jiang-Guo;Wang, Li-Li;Zhan, Wei-Li;Qi, Jun-Ying;Song, Jian-Xin
    • BMB Reports
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    • v.47 no.4
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    • pp.203-208
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    • 2014
  • To gain insights into the effect of MexB gene under the short interfering RNA (siRNA), we synthesized 21 bp siRNA duplexes against the MexB gene. RT-PCR was performed to determine whether the siRNA inhibited the expression of MexB mRNA. Changes in antibiotic susceptibility in response to siRNA were measured by the E-test method. The efficacy of siRNAs was determined in a murine model of chronic P. aeruginosa lung infection. MexB-siRNAs inhibited both mRNA expression and the activity of P. aeruginosa in vitro. In vivo, siRNA was effective in reducing the bacterial load in the model of chronic lung infection and the P. aeruginosa-induced pathological changes. MexB-siRNA treatment enhanced the production of inflammatory cytokines in the early infection stage (P < 0.05). Our results suggest that targeting of MexB with siRNA appears to be a novel strategy for treating P. aeruginosa infections.

Human Recombinant Endostatin Combined with Cisplatin Based Doublets in Treating Patients with Advanced NSCLC and Evaluation by CT Perfusion Imaging

  • Zhang, Feng-Lin;Gao, Er-Yun;Shu, Rong-Bao;Wang, Hui;Zhang, Yan;Sun, Peng;Li, Min;Tang, Wei;Jiang, Bang-Qin;Chen, Shuang-Qi;Cui, Fang-Bo
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6765-6768
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    • 2015
  • Aims: To study the effectiveness of human recombinant endostatin injection (Endostar(R)) combined with cisplatin doublets in treating advanced non-small cell lung cancer (NSCLC), and to evaluate outcome by CT perfusion imaging. Methods: From April 2011 to September 2014, 76 patients with advanced NSCLC who were treated with platinum-based doublets were divided into group A (36 patients) and group B (40 patients). Endostar(R) 15mg/day was administered 4 days before chemotherapy and combined with chemotherapy from day 5 in group A, and combined with chemotherapy from the first day in Group B. Endostar(R) in the two groups was injected intravenously for 14 days. Results: Treatment effectiveness in the two groups differed with statistical significance (p<0.05). Effectiveness evaluated by CT perfusion imaging, BF, BV, MTT and PS also demonstrated significant differences (all p<0.05). Adverse reactions in the two groups did not significantly vary (p> 0.05). Conclusions: The response rate with Endostar(R) administered 4 days before chemotherapy and combined with chemotherapy from day 5 in group A was better than Endostar(R) combined with chemotherapy from the first day, and CT perfusion imaging could be a reasonable method for evaluation of patient outcomes.