Chaotic dynamic characteristics of pressure fluctuation signals in hydro-turbine

Wen-Tao Su,Xiao-Bin Li,Chao-Feng Lan,Shi An,Jiansheng Wang,Feng-Chen Li 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.11

The pressure fluctuation characteristics in a Francis hydro-turbine running at partial flow conditions were studied based on the chaotic dynamic methods. Firstly, the experimental data of pressure fluctuations in the draft tube at various flow conditions was de-noised using lifting wavelet transformation, then, for the de-noised signals, their spectrum distribution on the frequency domain, the energy variation and the energy partition accounting for the total energy was calculated. Hereby, for the flow conditions ranging from no cavitation to severe cavitation, the chaos dynamic features of fluctuation signals were analyzed, including the temporal-frequency distribution, phase trajectory, Lyapunov exponent and Poincaré map etc. It is revealed that, the main energy of pressure fluctuations in the draft tube locates at low-frequency region. As the cavitation grows, the amplitude of power spectrum at frequency domain becomes larger. For all the flow conditions, all the maximal Lyapunov exponents are larger than zero, and they increase with the cavitation level. Therefore, it is believed that there indeed exist the chaotic attractors in the pressure fluctuation signals for a hydro-turbine.

Endovascular Treatment for Iliac Vein Compression Syndrome: a Comparison between the Presence and Absence of Secondary Thrombosis

Wen-Sheng Lou,Jian-Ping Gu,Xu He,Liang Chen,Hao-Bo Su,Guo-Ping Chen,Jing-Hua Song,Tao Wang 대한영상의학회 2009 Korean Journal of Radiology Vol.10 No.2

Objective: To evaluate the value of early identification and endovascular treatment of iliac vein compression syndrome (IVCS), with or without deep vein thrombosis (DVT). Materials and Methods: Three groups of patients, IVCS without DVT (group 1, n = 39), IVCS with fresh thrombosis (group 2, n = 52) and IVCS with non-fresh thrombosis (group 3, n = 34) were detected by Doppler ultrasonography, magnetic resonance venography, computed tomography or venography. The fresh venous thrombosis were treated by aspiration and thrombectomy, whereas the iliac vein compression per se were treated with a self-expandable stent. In cases with fresh thrombus, the inferior vena cava filter was inserted before the thrombosis suction, mechanical thrombus ablation, percutaneous transluminal angioplasty, stenting or transcatheter thrombolysis. Results: Stenting was performed in 111 patients (38 of 39 group 1 patients and 73 of 86 group 2 or 3 patients). The stenting was tried in one of group 1 and in three of group 2 or 3 patients only to fail. The initial patency rates were 95% (group 1), 89% (group 2) and 65% (group 3), respectively and were significantly different (p = 0.001). Further, the six month patency rates were 93% (group 1), 83% (group 2) and 50% (group 3), respectively, and were similarly significantly different (p = 0.001). Both the initial and six month patency rates in the IVCS patients (without thrombosis or with fresh thrombosis), were significantly greater than the patency rates of IVCS patients with non-fresh thrombosis. Conclusion: From the cases examined, the study suggests that endovascular treatment of IVCS, with or without thrombosis, is effective. Objective: To evaluate the value of early identification and endovascular treatment of iliac vein compression syndrome (IVCS), with or without deep vein thrombosis (DVT). Materials and Methods: Three groups of patients, IVCS without DVT (group 1, n = 39), IVCS with fresh thrombosis (group 2, n = 52) and IVCS with non-fresh thrombosis (group 3, n = 34) were detected by Doppler ultrasonography, magnetic resonance venography, computed tomography or venography. The fresh venous thrombosis were treated by aspiration and thrombectomy, whereas the iliac vein compression per se were treated with a self-expandable stent. In cases with fresh thrombus, the inferior vena cava filter was inserted before the thrombosis suction, mechanical thrombus ablation, percutaneous transluminal angioplasty, stenting or transcatheter thrombolysis. Results: Stenting was performed in 111 patients (38 of 39 group 1 patients and 73 of 86 group 2 or 3 patients). The stenting was tried in one of group 1 and in three of group 2 or 3 patients only to fail. The initial patency rates were 95% (group 1), 89% (group 2) and 65% (group 3), respectively and were significantly different (p = 0.001). Further, the six month patency rates were 93% (group 1), 83% (group 2) and 50% (group 3), respectively, and were similarly significantly different (p = 0.001). Both the initial and six month patency rates in the IVCS patients (without thrombosis or with fresh thrombosis), were significantly greater than the patency rates of IVCS patients with non-fresh thrombosis. Conclusion: From the cases examined, the study suggests that endovascular treatment of IVCS, with or without thrombosis, is effective.

Amphiphilic Norbornene-Based Diblock Copolymers Containing Polyhedral Oligomeric Silsesquioxane Prepared by Living Ring Opening Metathesis Polymerization

Su Dong Park,Wen Tao Xu,Chan Hong Chung,Young Hwan Kwon 한국고분자학회 2008 Macromolecular Research Vol.16 No.2

Large-scale dataset from China gives new insights into leaf margin-temperature relationships

Chen, Wen-Yun,Su, Tao,Adams, Jonathan M.,Jacques, Fré,dé,ric M.B.,Ferguson, David K.,Zhou, Zhe-Kun Elsevier 2014 Palaeogeography, palaeoclimatology, palaeoecology Vol.402 No.-

Leaf margin analysis (LMA) is an important method of estimating paleotemperatures from fossil leaf floras or modern floras. Although some calibration has been carried out based upon large-scale studies of modern forests, most of this research has been in North America and Europe, with relatively little calibration work in East Asia. In the present study, we used species range maps of 3116 native dicot trees of China to derive synthetic local floras for each county from the Chinese humid region, and compared the percentage of untoothed leaf margined species with several temperature and precipitation related parameters. The results confirm the generally strong relationship between the proportion of species with untoothed leaf margins and climatic parameters within China. Leaf habit (deciduous vs. evergreen) does not strongly affect this relationship. The transfer function obtained from China, while not identical, is similar to those obtained from other regions, and is affected by regional restrictions, such as complex topography and relic taxa. As such it clarifies the potential range of error inherent in the LMA method as applied to paleodimate reconstruction. It is possible, however, that with the close similarity of the modern Chinese tree floras to Neogene floras in the Northern Hemisphere, the present estimate offers a better transfer function for reconstructing the Neogene paleoclimate in various regions without extremely cold conditions across the Northern Hemisphere. (C) 2014 Published by Elsevier B.V.

Chinese Patients with Gastric Cancer Need Targeted Adjuvant Chemotherapy Schemes

Shi, Wen-Tao,Wei, Lei,Xiang, Jin,Su, Ke,Ding, Qiong,Tang, Meng-Jie,Li, Ji-Qiang,Guo, Yi,Wang, Pu,Zhang, Jing-Wei Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

Background: Gastric cancer (GC) is one of the most common cancers in China. Adjuvant chemotherapy (AC) is a routine auxiliary treatment for GC recommended by the guidelines issued in 2011 by the Ministry of Health of the People's Republic of China, but the relevant credible consequences in China have been insufficient because of China's late start and ethical concerns. Methods: A series of databases, including Cochrane Library, MEDLINE, EMBASE, the Chinese database of the National Knowledge Infrastructure and the VIP database, were searched by 2 reviewers independently for studies investigating AC for GC through March 2012. The retrieved literature was screened according to the eligibility criteria. Results: A total of 35 randomized control trials (RCTs) were subjected to the final analysis, including 4,043 patients in treatment group and 3,884 in the control group, as well as 4 clinical-control trials (CCTs), which accessed the final analysis with 238 and 252 patients, respectively. AC reduced the risk of death as a protective treatment with statistical significance (HR=0.91, 95%CI: [0.85, 0.97], P=0.002), and it seemed more effective for Asian than non-Asian patients. The effects of AC were not influenced by the starting time (P>0.05). D2 lymphadenectomy-based chemotherapy was effective (HR=0.89, 95%CI: [0.80, 0.99], P=0.04). Oral S-1 40 mg/m2 after D2 lymphadenectomy might be a better choice for Asians with advanced GC and might result in a greater reduction of adverse events than in non-Asian patients. GRADE quality assessment determined that the strength of the evidence from foreign studies from Europe, the United States and Asian countries other than China was high, while it was moderate for Chinese studies. Conclusion: AC was effective or even curative in Chinese patients in general, although it is still necessary to optimize a targeted AC scheme for Chinese patients with GC.

Clinical Observation and Therapeutic Evaluation of Rh-endostatin Combined with DP Regimen in Treating Patients with Advanced Esophageal Cancer

Deng, Wen-Ying,Song, Tao,Li, Ning,Luo, Su-Xia,Li, Xiang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Objective: To observe the curative effects of rh-endostatin combined with DP regimen in treating patients with advanced esophageal cancer and analyze the correlation of CT perfusion (CTP) parameters and the expression of vascular endothelial growth factor (VEGF). Methods: Twenty patients with esophageal cancer confirmed pathologically were randomly divided into combined treatment (rh-endostatin+DP regimen) group and single chemotherapy group, 10 patients in each group, respectively. All patients were given conventional CT examination and CTP imaging for primary tumor. The level of VEGF, the size of tumor and CTP parameters (BF, BV, PS and MTT) before treatment and after 2 cycles of treatment were determined for the comparison and the correlation between CTP parameters and VEGF expression was analyzed. Results: the therapeutic effect of rh-endostatin+DP regimen group was superior to single chemotherapy group. VEGF level after treatment in rh-endostatin+DP regimen group was obviously lower than single chemotherapy group (P<0.01). The expression of VEGF had positive correlation with BF and BV but negative correlation with MTT. Compared with treatment before for rh-endostatin+DP regimen group, BF, BV and PS decreased while MTT increased after treatment (P<0.05). However, there were no significant differences between treatment before and after treatment in single chemotherapy (P>0.05). Conclusions: Rh-endostatin can down-regulate the expression of VEGF in esophageal cancer, change the state of hypertransfusion and high permeability of tumor vessels and had the better curative effect and slighter adverse reactions when combined with chemotherapy.

Behavior and simplified analysis of steel-concrete composite beams subjected to localized blast loading

Guo-Qiang Li,Su-Wen Chen,Tao-Chun Yang 국제구조공학회 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.32 No.2

Finite element simulations are increasingly used in structural analysis and design, especially in cases where complex structural and loading conditions are involved. Due to considerable progresses in computer technology as well as nonlinear finite-element analysis techniques in past years, it has become possible to pursue an accurate analysis of the complex blast-induced structural effects by means of numerical simulations. This paper aims to develop a better understanding of the behavior of steel-concrete composite beams (SCCB) under localized blast loading through a numerical parametric study. A finite element model is set up to simulate the blast-resistant features of SCCB using the transient dynamic analysis software LS-DYNA. It is demonstrated that there are three dominant failure modes for SCCB subjected to localized blast loading. The effect of loading position on the behavior of SCCB is also investigated. Finally, a simplified model is proposed for assessing the overall response of SCCB subjected to localized blast loading.

Behavior and simplified analysis of steel-concrete composite beams subjected to localized blast loading

Li, Guo-Qiang,Yang, Tao-Chun,Chen, Su-Wen Techno-Press 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.32 No.2

Finite element simulations are increasingly used in structural analysis and design, especially in cases where complex structural and loading conditions are involved. Due to considerable progresses in computer technology as well as nonlinear finite-element analysis techniques in past years, it has become possible to pursue an accurate analysis of the complex blast-induced structural effects by means of numerical simulations. This paper aims to develop a better understanding of the behavior of steel-concrete composite beams (SCCB) under localized blast loading through a numerical parametric study. A finite element model is set up to simulate the blast-resistant features of SCCB using the transient dynamic analysis software LS-DYNA. It is demonstrated that there are three dominant failure modes for SCCB subjected to localized blast loading. The effect of loading position on the behavior of SCCB is also investigated. Finally, a simplified model is proposed for assessing the overall response of SCCB subjected to localized blast loading.

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.

Recombinant human β-defensin130 inhibited the growth of foodborne bacteria through membrane disruption and exerted anti-inflammatory activity

Bin Dong,Yanjun Lin,Zhiwei Su,Chunlong Sun,Jun Wang,Shijun Fu,Wen Du,Tao Wu 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.7

Foodborne pathogens causing food poisoning and infections are detrimental to human health, and the abuse of antibiotics induced severe antibiotic resistance in past decades. Thus, it is urgent to develop new antimicrobial agents. In the current study, human β-defensin 130 (hBD130), which is an antimicrobial peptide identified in human macrophages in 2017, was initially produced in Pichia pastoris. The purified hBD130 demonstrated broad bactericidal spectrum against foodborne pathogens through a membrane disruption, with concentrations ranging from 10 to 45 μg/mL. Moreover, hBD130 showed a low hemolytic effect and nearly no cytotoxicity to mammalian cells with a dosage of 400 μg/mL. In addition, the secretion amounts and mRNA levels of NO, IL-6, IL-1β, and TNF-α in LPS-induced mouse macrophage were significantly decreased with 1 mg/mL of hBD130. Taken together, these results showed that hBD130 is a promising antimicrobial agent to treat foodborne bacterial infections and inflammation.