Low cycle fatigue properties of hydrogenated welding sheets of Zr–Sn–Nb alloy using funnel-shaped flat specimens

Lian-feng Wei,Chen Bao,Shi-zhong Wang,Yong Zheng,Meng-bin Zhou 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.8

Low cycle fatigue tests on the hydrogenated welding seam of ZreSneNb alloy at room temperature and 360 C had been carried out by using the funnel-shaped flat specimens. The relationships between nominal stress & strain directly measured across the funnel and local stress & strain at the root of the funnel are given by considering cyclic plasticity correction. The results show that the fatigue resistance of welding seam at room temperature is only slightly better than that at 360 C. Probabilistic fatigue life curves are obtained by using a two-parameter power function.

Research on an Anchor Point Lever Beam Coupling Type Tuning Fork Micro-gyroscope

Lian-min Cao,Jian-wei Li,Xian-wen Liu,Feng-yao Sun 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.6

This paper has designed an anchor point lever beam coupled tuning fork micro-gyroscope and tested its output performance. The tuning fork micro-gyro is designed to eliminate the output error caused by orthogonal coupling and in-phase-inverting coupling by structural decoupling and electrical decoupling, and can improve the anti-vibration performance and the modal optimization ability. It has derived the dynamic response working model of the non-ideal tuning fork micro-gyroscope, and optimized the structural parameters of the micro-gyroscope by simulation analysis. The microstructure processing has been realized by the SOI-MEMS process, sealed the processed structural prototype, and tested the performance through the established experimental system. According to the test results, the designed micro-gyroscope driving direction has greatly reduced the in-phase-inverting coupling through the anchor coupling lever beam, and the detection direction eff ectively suppressed the in-phase-inverting coupling through the stiff ness matching electrode. While closed-loop detecting, the measured Aallan variance zero-bias stability is 1.779°/h, and the 1σ zero-bias stability is 8.3°/h. While applying a stiff ness matching voltage, the measured vibration sensitivity is 23.9°/h/g.

Determination of a Monitoring Scheme for Controlling Construction Errors of a Cable-strut Tensile Structure

Lian-meng Chen,Wei-feng Gao,Dong Hu,Yi-yi Zhou,Fu-bo Zhang,Shi-lin Dong 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.10

Construction errors are inevitable in real cable-strut tensile structures. Nevertheless, the relevant work, especially the monitoring scheme design work, to control the construction errors is lacking. At present, the monitoring schemes always lay out the monitored members in the places with great internal force or great deformation, do not consider the method to control the construction errors and do not explain the method to lay out the monitored members in fundamental theory. To address this situation, the element length error, which is an important construction error affecting the bearing performance, is considered as the factor variable and the fundamental equation of pre-stress deviation and element length error is derived firstly. Next the methods to express the pre-stress deviation, which are only derived from the active cable length errors or from both the active cable and passive cable length errors, are discussed. After that, based on the condition that the errors can be solved and compensated, the least number of monitored members is determined. Moreover, those members sensitive to cable length deviation of active cables are selected as monitored members. In order to evaluate the effect level caused by passive cable length deviation, two evaluation parameters Δ and ρ are further discussed. Finally, one cable-strut tensile structure example is employed to verify the proposed method and the results of the example studies indicate that the least necessary number of monitored members can be achieved for the accurate solution and compensation of active cable length deviations. Different members have different sensitivities to the change of the length in active cables and those members with great sensitivities can be chosen in prior as monitored members. The evaluation parameters Δ and ρ can be used to analyze the source of errors and to evaluate the error effect level caused by the passive cable length deviation.

Identification and Adjustment of the Pretension Deviation in Cable-Strut Tensile Structures

Lian-meng Chen,Zhichao Jiang,Wei-feng Gao,Yi-yi Zhou 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.1

Construction errors inevitably arise in real cable-strut tensile structures. Nevertheless, construction error analysis and evaluation, as well as methods to identify the source of the errors and proper adjustment methods to compensate for these errors, remain in their infancies. In this study, the relationship between pretension deviation and element length deviation is first established based on the three basic equations for pin-joint structures. On this basis, identification methods are proposed to identify the sources of the pretension deviation caused by the active cable length deviation and the pretension deviation caused by both the active and the passive cable length deviations. Using measured data, an adjustment method is developed for the pretension deviation under different scenarios. Furthermore, the effectiveness of the adjustment method for the pretension deviation is discussed using the evaluation indices. Finally, a case study is presented and demonstrates that the proposed identification method can identify the sources of the pretension deviations. The number of adjusted cables will affect the level of adjustment for the pretension deviation. During the adjustment of the pretension deviation, different adjustment methods will result in different shape deviations and different maximum displacements.

Robustness Analysis of a Flexible Cable-Strut Tensile Structure

Lian-meng Chen,Wei-feng Gao,Zhichao Jiang,Yi-yi Zhou,Fu-bo Zhang,Shi-lin Dong 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.5

Currently, the robustness analysis of structure is primarily related to rigid structures, and little has been done to study the robustness of spatial fl exible cable-strut tensile structures with larger span, more complex forms, lower redundancy, more sensitivity to unexpected interference such as construction deviations, etc. Based on the H ∞ theory, this paper starts with the fundamental theory and develops analysis method for the robustness of fl exible cable-strut tensile structures, and then the relationships between the structural robustness and some design parameters such as initial pre-stress level, load distribution form, structural span, cross-section area, rise-span ratio, etc. are analysed through a case study of a concrete cable-strut tensile structure in China. On this basis, the eff ects of construction errors such as element-length error and supporting node position error are further analysed. Finally, the importance of each kind of element is analysed by means of conceptual removal of element. The results show that the higher the initial pre-stress level, the larger the element cross-section, the smaller the structural span, the larger the rise-span ratio and the more uniform the load distribution, the stronger the structural robustness. In the limited construction error range, the element-length error and the supporting node position error have little eff ects on the robustness of the structure. The hoop cables are the more important elements and the elements in inner region of the structure are of comparatively lower importance in the cable dome structure in this study.

Optimization of Reference Genes for Normalization of the Quantitative Polymerase Chain Reaction in Tissue Samples of Gastric Cancer

Zhao, Lian-Mei,Zheng, Zhao-Xu,Zhao, Xiwa,Shi, Juan,Bi, Jian-Jun,Pei, Wei,Feng, Qiang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.14

For an exact comparison of mRNA transcription in different samples or tissues with real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), it is crucial to select a suitable internal reference gene. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and beta-actin (ACTB) have been frequently considered as house-keeping genes to normalize for changes in specific gene expression. However, it has been reported that these genes are unsuitable references in some cases, because their transcription is significantly variable under particular experimental conditions and among tissues. The present study was aimed to investigate which reference genes are most suitable for the study of gastric cancer tissues using qRT-PCR. 50 pairs of gastric cancer and corresponding peritumoral tissues were obtained from patients with gastric cancer. Absolute qRT-PCR was employed to detect the expression of GAPDH, ACTB, RPII and 18sRNA in the gastric cancer samples. Comparing gastric cancer with corresponding peritumoral tissues, GAPDH, ACTB and RPII were obviously upregulated 6.49, 5.0 and 3.68 fold, respectively. Yet 18sRNA had no obvious expression change in gastric cancer tissues and the corresponding peritumoral tissues. The expression of GAPDH, ${\beta}$-actin, RPII and 18sRNA showed no obvious changes in normal gastric epithelial cells compared with gastric cancer cell lines. The carcinoembryonic antigen (CEA), a widely used clinical tumor marker, was used as a validation gene. Only when 18sRNA was used as the normalizing gene was CEA obviously elevated in gastric cancer tissues compared with peritumoral tissues. Our data show that 18sRNA is stably expressed in gastric cancer samples and corresponding peritumoral tissues. These observations confirm that there is no universal reference gene and underline the importance of specific optimization of potential reference genes for any experimental condition.

Identification of a Lead small-molecule inhibitor of anthrax Lethal toxin by using fluorescence-based high-throughput screening

( Dong Wei ),( Zhao Yun Bu ),( Ai Lian Yu ),( Feng Li ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.12

Inhalational anthrax is caused by B. anthracis, a virulent spore- forming bacterium which secretes anthrax toxins consisting of protective antigen (PA), lethal factor (LF) and edema factor (EF). LF is a Zn-dependent metalloprotease and is the main determinant in the pathogenesis of anthrax. Here we report the identification of a lead small-molecule inhibitor of anthrax lethal factor by screening an available synthetic small-molecule inhibitor library using fluorescence-based high-throughput screening (HTS) approach. Seven small molecules were found to have inhibitory effect against LF activity, among which SM157 had the highest inhibitory activity. All theses small molecule inhibitors inhibited LF in a noncompetitive inhibition mode. SM157 and SM167 are from the same family, both having an identical group complex, which is predicted to insert into S1` pocket of LF. More potent small-molecule inhibitors could be developed by modifying SM157 based on this identical group complex. [BMB reports 2011; 44(12): 811-815]

Lymph Node Ratio is More Predictive than Traditional Lymph Node Stratification in Lymph Node Positive Invasive Breast Cancer

Bai, Lian-Song,Chen, Chuang,Gong, Yi-Ping,Wei, Wen,Tu, Yi,Yao, Feng,Li, Juan-Juan,Wang, Li-Jun,Sun, Sheng-Rong Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Objective: To evaluate the relationships between lymph node ratio (LNR, the ratio of positive lymph nodes in excised axillary lymph nodes) and disease-free survival (DFS) by comparing with traditional absolute positive lymph node number (pN classification) for prediction of breast cancer (BC) progrnosis. Methods and Patients: We retrospectively reviewed patients who received comprehensive therapy in Department of Breast Surgery, Hubei Cancer Hospital, China from Jan 2002 to Dec 2006 (Group A), and Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, China from Jun 2008 to May 2012 (Group B). Patients were allocated to low-risk (${\leq}0.20$), intermediate-risk (> 0.20 but ${\leq}0.65$), high-risk (>0.65) groups by LNR. The primary endpoint was 5-DFS. Results: A total of 294 patients were included in our study. LNR was verified as a negative prognostic factor for DFS (P=0.002 in Group A, P<0.0001 in Group B). Then we found the effects of pN and LNR delamination on disease-free survival (DFS) had statistical significance (P=0.012 for pN and P=0.031 for LNR stratification in Group A, both of them P<0.001 in Group B). Compared to pN staging, LNR staging displayed superior performance in prognosis, the adjusted hazard ratio of recurrence being 2.07 (95%CI, 1.07 to 4.0) for intermediate risk group (P=0.030) and 2.44 (95%CI, 1.21 to 4.92) for high risk group (P=0.013) in Group A. Conclusions: LNR stratification proved an adverse prognostic factor of DFS in lymph nodes positive invasive BC using cut-off values 0.20 and 0.65, and was more predictive than traditional pN classification for 5-DFS.

DNA Methylation in Peripheral Blood: A Potential Biomarker for Cancer Molecular Epidemiology

Li, Lian,Choi, Ji-Yeob,Lee, Kyoung-Mu,Sung, Hyuna,Park, Sue K.,Oze, Isao,Pan, Kai-Feng,You, Wei-Cheng,Chen, Ying-Xuan,Fang, Jing-Yuan,Matsuo, Keitaro,Kim, Woo Ho,Yuasa, Yasuhito,Kang, Daehee Japan Epidemiological Association 2012 Journal of epidemiology Vol.22 No.5

<P>Aberrant DNA methylation is associated with cancer development and progression. There are several types of specimens from which DNA methylation pattern can be measured and evaluated as an indicator of disease status (from normal biological process to pathologic condition) and even of pharmacologic response to therapy. Blood-based specimens such as cell-free circulating nucleic acid and DNA extracted from leukocytes in peripheral blood may be a potential source of noninvasive cancer biomarkers. In this article, we describe the characteristics of blood-based DNA methylation from different biological sources, detection methods, and the factors affecting DNA methylation. We provide a comprehensive literature review of blood-based DNA methylation as a cancer biomarker and focus on the study of DNA methylation using peripheral blood leukocytes. Although DNA methylation patterns measured in peripheral blood have great potential to be useful and informative biomarkers of cancer risk and prognosis, large systematic and unbiased prospective studies that consider biological plausibility and data analysis issues will be needed in order to develop a clinically feasible blood-based assay.</P>

From 3D to 4D printing: approaches and typical applications

Ye Zhou,Wei Min Huang,Shu Feng Kang,Xue Lian Wu,Hai Bao Lu,Jun Fu,Haipo Cui 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.10

With the additional dimension, 4D printing is emerging as a novel technique to enable configuration switching in 3D printed items. Inthis paper, four major approaches, namely self-assembly of elements, deformation mismatch, bi-stability, and the Shape memory effect(SME), are identified as the generic approaches to achieve 4D printing. The main features of these approaches are briefly discussed. Utilizingthese approaches either individually or in a combined manner, the potential of 4D printing to reshape product design is demonstratedby a few example applications.