Wechat as a Learning Community in EFL Teaching : An Action Research Study

Cheng Xiangli,Dong Tongtong 아시아영어교육학회 2017 The Journal of Asia TEFL Vol.14 No.3

A Survey of Engineering Student's Use of English Language Learning Strategies

Xiangli Cheng,Kang Xu,Yue Ma 아시아영어교육학회 2007 The Journal of Asia TEFL Vol.4 No.2

Zearalenone exposure affects epigenetic modifications of mouse eggs

Zhu, Cheng-Cheng,Hou, Yan-Jun,Han, Jun,Cui, Xiang-Shun,Kim, Nam-Hyung,Sun, Shao-Chen Oxford University Press 2014 Mutagenesis Vol.29 No.6

<P>Zearalenone (ZEA) is a mycotoxin produced by various <I>Fusarium</I> fungi, which has been shown to cause several cases of mycotoxicosis in farm animals and humans. However, there is no evidence regarding the effect of ZEA on mouse egg developmental competence. In this study, we found that the activation rate of maturated oocytes was affected in mice by ZEA treatment, indicating that ZEA affects egg developmental competence. And we explored possible mechanisms of low mouse maturated oocyte developmental competence after ZEA treatment from an epigenetic modification perspective. The fluorescence intensity analysis showed that 5-methyl cytosine level increased after ZEA treatment, indicating that the general DNA methylation level increased in the treated eggs. Moreover, histone methylations were also altered: H3K4me2 as well as H3K9me3 and H4K20me1, me2, me3 levels decreased in eggs that were cultured in high-dose ZEA medium. Thus, our results indicated that ZEA decreased egg developmental competence by affecting the epigenetic modifications.</P>

Improving the Stability Behavior of Limiting Zeros for Multivariable Systems Based on Multirate Sampling

Cheng Zeng,Shan Liang,Shuwen Xiang 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.6

It is well-known that existence of unstable sampling zeros is recognized as a major barrier in many control problems, and stability of sampling zeros, in general, depends on the type of hold circuit used to generate the continuous-time system input. This paper is concerned with stability of limiting zeros, as the sampling period tends to zero, of multivariable sampled-data models composed of a generalized sample hold function (GSHF), a continuous-time plant with the relative degrees being two and three, and a sampler in cascade. In particular, the main focus of the paper is how to preserve the stability of limiting zeros when at least one of the relative degrees of a multivariable system is more than two. In this case, the asymptotic properties of the limiting zeros on the basis of normal form representation of continuous-time systems are analyzed and approximate expressions for their stability are discussed as power series expansions with respect to a sufficiently small sampling period. More importantly, unstable sampling zeros of the sampled-data models mentioned above can be avoided successfully through the contribution of this paper, whereas a zero-order hold (ZOH) or a fractional-order hold (FROH) fails to do so. It is a further extension of previous results for single-input single-output cases to multivariable systems.

Prediction of postoperative pancreatic fistula using a nomogram based on the updated definition

Cheng-Xiang Guo,Yi-Nan Shen,Qi Zhang,Xiao-Zhen Zhang,Jun-Li Wang,Shun-Liang Gao,Jian-Ying Lou,Ri-Sheng Que,Tao Ma,Ting-Bo Liang,Xue-Li Bai 대한외과학회 2020 Annals of Surgical Treatment and Research(ASRT) Vol.98 No.2

Purpose: The International Study Group on Pancreatic Fistula’s definition of postoperative pancreatic fistula (POPF) has recently been updated. This study aimed to identify risk factors for POPF in patients having pancreaticoduodenectomy (PD) and to generate a nomogram to predict POPF. Methods: Data on 298 patients who underwent PD from March 2012 to October 2017 was retrospectively reviewed and POPF statuses were redefined. A nomogram was constructed using data from 220 patients and validated using the remaining 78 patients. Independent risk factors for POPF were identified using univariate and multivariate analyses. A predictive nomogram was established based on the independent risk factors and was compared with existing models. Results: Texture of the pancreas, size of the main pancreatic duct, portal vein invasion, and definitive pathology were the identified risk factors. The nomogram had a C-index of 0.793 and was internally validated. The nomogram performed better (C-index of 0.816) than the other most cited models (C-indexes of 0.728 and 0.735) in the validation cohort. In addition, the nomogram can assign patients into low- (less than 10%), intermediate- (10% to 30%), and high-risk (equal or higher than 30%) groups to facilitate personalized management. Conclusion: The nomogram accurately predicted POPF in patients having PD.

Ultimate behavior of long-span steel arch bridges

Cheng, Jin,Jiang, Jian-Jing,Xiao, Ru-Cheng,Xiang, Hai-Fan Techno-Press 2002 Structural Engineering and Mechanics, An Int'l Jou Vol.14 No.3

Because of the increasing span of arch bridges, ultimate capacity analysis recently becomes more focused both on design and construction. This paper investigates the static and ultimate behavior of a long-span steel arch bridge up to failure and evaluates the overall safety of the bridge. The example bridge is a long-span steel arch bridge with a 550 m-long central span under construction in Shanghai, China. This will be the longest central span of any arch bridge in the world. Ultimate behavior of the example bridge is investigated using three methods. Comparisons of the accuracy and reliability of the three methods are given. The effects of material nonlinearity of individual bridge element and distribution pattern of live load and initial lateral deflection of main arch ribs as well as yield stresses of material and changes of temperature on the ultimate load-carrying capacity of the bridge have been studied. The results show that the distribution pattern of live load and yield stresses of material have important effects on bridge behavior. The critical load analyses based on the linear buckling method and geometrically nonlinear buckling method considerably overestimate the load-carrying capacity of the bridge. The ultimate load-carrying capacity analysis and overall safety evaluation of a long-span steel arch bridge should be based on the geometrically and materially nonlinear buckling method. Finally, the in-plane failure mechanism of long-span steel arch bridges is explained by tracing the spread of plastic zones.

Ginsenoside Rh2 attenuates microglial activation against toxoplasmic encephalitis via TLR4/NF-kB signaling pathway

Xiang Xu,Lan Jin,Tong Jiang,Ying Lu,Fumie Aosai,Hu-Nan Piao,Guang-Hua Xu,Cheng-Hua Jin,Xue-Jun Jin,Juan Ma,Lian-Xun Piao 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.5

Background: Ginsenoside Rh2 (GRh2) is a characterized component in red ginseng widely used in Korea and China. GRh2 exhibits a wide range of pharmacological activities, such as anti-inflammatory, antioxidant, and anticancer properties. However, its effects on Toxoplasma gondii (T. gondii) infection have not been clarified yet. Methods: The effect of GRh2 against T. gondii was assessed under in vitro and in vivo experiments. The BV2 cells were infected with tachyzoites of T. gondii RH strain, and the effects of GRh2 were evaluated by MTT assay, morphological observations, immunofluorescence staining, a trypan blue exclusion assay, reverse transcription PCR, and Western blot analyses. The in vivo experiment was conducted with BALB/c mice inoculated with lethal amounts of tachyzoites with or without GRh2 treatment. Results and conclusion: The GRh2 treatment significantly inhibited the proliferation of T. gondii under in vitro and in vivo studies. Furthermore, GRh2 blocked the activation of microglia and specifically decreased the release of inflammatory mediators in response to T. gondii infection through TLR4/NF-kB signaling pathway. In mice, GRh2 conferred modest protection from a lethal dose of T. gondii. After the treatment, the proliferation of tachyzoites in the peritoneal cavity of infected mice markedly decreased. Moreover, GRh2 also significantly decreased the T. gondii burden in mouse brain tissues. These findings indicate that GRh2 exhibits an antieT. gondii effect and inhibits the microglial activation through TLR4/NF-kB signaling pathway, providing the basic pharmacological basis for the development of new drugs to treat toxoplasmic encephalitis.

The association betwwen the oocyte pool and aneuploidy : a comparative study of the reproductive potential of young and aged mice

Xiang-wei Fu,Jin-Mei Cheng,Ming-xing Yue,Yun-peng Hou,Shi-en Zhu 한국동물생명공학회(구 한국동물번식학회) 2014 한국동물번식학회 한중일 심포지엄 Vol.2014 No.1

The effect of light on follicular development in laying hens

Cheng, Shi Bin,Li, Xian Qiang,Wang, Jia Xiang,Wu, Yan,Li, Peng,Pi, Jin Song Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.11

Objective: The oxidative stress status and changes of chicken ovary tissue after shading were studied, to determine the mechanism of the effect of shading on follicular development. Methods: Twenty healthy laying hens (40 weeks old) with uniform body weight and the same laying rate were randomly divided into two groups (the shading group and normal light group). In the shading group, the cage was covered to reduce the light intensity inside the cage to 0 without affecting ventilation or food intake. The normal lighting group received no additional treatment. After 7 days of shading, oxidative stress related indicators and gene expression were detected. Results: Analysis of paraffin and ultrathin sections showed that apoptosis of ovarian granulosa cells (GCs) increased significantly after light shading. Enzyme linked immunosorbent assay results revealed that the levels of total antioxidant capacity, malondialdehyde, superoxide dismutase (SOD), glutathione, catalase (CAT), and other substances in the sera, livers, ovaries, and follicular GCs of laying hens increased significantly after shading for 7 days; and reactive oxygen species (ROS) levels in the livers of laying hens also increased significantly. ROS in the serum, ovarian and GCs also increased. After shading for 7 days, the levels of 8-hydroxy-2 deoxyguanosine in the sera and ovarian tissues of laying hens increased significantly. Cell counting kit-8 detection showed that the proliferation activity of GCs in layer follicles decreased after shading for 7 days; the expression level of the anti-apoptotic gene B-cell lymphoma-2 in ovarian tissue and follicular GCs was significantly reduced, and the expression levels of pro-apoptotic caspase 3 (casp3), and SOD, glutathione peroxidase 2 (GPX2), and CAT were all significantly increased. Conclusion: Oxidative stress induced by shading light has a serious inhibitory effect on follicular development during reproduction in laying hens.

Design and development of PCD micro straight edge end mills for micro/ nano machining of hard and brittle materials

Xiang Cheng,Zhigang Wang,Kazuo Nakamoto,Kazuo Yamazaki 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.11

One of the biggest challenges for mechanical micro/nano milling is the design and fabrication of high precision and high efficiency micro milling tools. Commercially available micro milling tools are either too expensive (around several hundred US dollars) or simply made from downsizing of macro milling tools, which is sometimes not appropriate for the specific micro/nano milling requirements. So the design and fabrication of custom micro milling tools are necessary. In this paper, a micro straight edge endmill (SEE) is designed. Static and dynamic FEM analyses have been done for the SEEs with different rake angles trying to identify their stiffness and natural frequencies. By wire electrical discharge machining (WEDM), the SEEs made of polycrystalline diamond (PCD) with three different rake angles have been fabricated. The evaluation milling on tungsten carbide (WC) and silicon wafer have processed on a nano milling center. Experimental results show the SEEs have a good ability to simultaneously micro/nano milling of both the side and bottom surfaces with submicron surface roughness, and the SEE has high accuracy for large aspect ratio thin wall machining. The milling experiments on silicon wafer have successfully demonstrated that ductile mode machining was achieved and the coolant played an important role in silicon wafer milling.