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Articles by Yan Li
Total Records ( 25 ) for Yan Li
  Renxi Wang , Gencheng Han , Jianan Wang , Guojiang Chen , Ruonan Xu , Liyan Wang , Xia Li , Beifen Shen and Yan Li
  Problem statement: More and more evidences have shown that human cancer cells can express Foxp3, the regulatory T cell-associated transcription factor. The role of Foxp3 in human cancer cells is still unclear. We detected Foxp3 expression in human pancreatic cancer cell line PANC-1. SiRNA assays showed that Foxp3 expression suppressed the expression of TGF- and IL-10 which could induce immune tolerance. Approach: Thus, we proposed that Foxp3 expression in PANC-1 cells controlled the response but not tolerance characteristics of the cells. To prove the proposal, we first developed the PANC-1 cell-induced the immune response model. PANC-1 cells induced response in autoimmune Non-Obese Diabetes (NOD) mice aged of >12 weeks. In vitro cell co-cultured assay demonstrated that PANC-1 induced response in splenocytes from NOD mice aged of >12 weeks. Results: In the same time, we found that inflammatory cytokine such as INF-, IL-2 and IL-17 increased and anti-inflammatory cytokine such as IL-4, IL-10 and TGF- decreased in the co-cultured supernatant. These results demonstrate that PANC-1 cells induced response in splenocytes from NOD mice aged of >12 weeks. SiRNA assays showed that Foxp3 in PANC-1 cells controlled the response in the co-cultured cells. Conclusion: The results suggested that Foxp3 control the immunological response characteristics of PANC-1 cells in autoimmune condition.
  Xia Wu , Yan Li , Guang-Peng Li , Dongshan Yang , Yongli Yue , Lingling Wang , Kehan Li , Penghui Xin , Shorgan Bou and Haiquan Yu
  Reprogramming impairment of DNA methylation may be partly responsible for the low efficiency in somatic cell nuclear transfer. In this study, bovine fibroblast cells were transfected with enhancer green fluorescence protein (eGFP), and then treated with a histone-deacetylase inhibitor, trichostatin A (TSA). The results showed that the effect of TSA on transfected cells was dose dependent. When the TSA concentration was over 5 ng/ml, cell proliferation was significantly inhibited. The majority of the cells died when TSA reached 100 ng/ml (P < 0.01). The number of cells in the S phase was significantly decreased in the 5- to 50-ng/ml TSA-treated groups, while the majority of the cells were at the G0/G1 phases. The number of eGFP-expressed cells were approximately twofold higher in 25-ng/ml (30.5%) and 50-ng/ml (29.5%) TSA groups than the control (15.0%). Reduced DNA methylation and improved histone acetylation were observed when the cells were treated with 10 to 50 ng/ml of TSA. Transfer of the TSA-treated cells to enucleated recipient oocytes resulted in similar cleavage rates among the experimental groups and the control. Cells treated with 50 ng/ml of TSA resulted in significantly lower blastocyst development (9.9%) than the other experimental and the control groups (around 20%). Analysis of the putative blastocysts showed that 86.7% of the embryos derived from TSA-treated cells were eGFP positive, which was higher than that from untreated cells (68.8%). In conclusion, treatment of transfected cells with TSA decreased the genome DNA methylation level, increased histone acetylation, and eGFP gene expression was activated. Donor cells with reduced DNA methylation did not improve subsequent cloned embryo development; however, transgene expression was improved in cloned embryos.
  Shujuan Sun , Yan Li , Qiongjie Guo , Changwen Shi , Jinlong Yu and Lin Ma
  Combination therapy could be of use for the treatment of fungal infections, especially those caused by drug-resistant fungi. However, the methods and approaches used for data generation and result interpretation need further optimizing. The fractional inhibitory concentration index (FICI) is the most commonly used method, but it has several drawbacks in characterizing antifungal drug interaction. Alternatively, some new methods can be used such as the ΔE model (difference between the predicted and measured fungal growth percentages) and the response surface approach, which uses the concentration-effect relationship over the whole concentration range instead of just the MIC. In the present study, in vitro interactions between tacrolimus (FK506) and three azoles—fluconazole (FLC), itraconazole (ITR), and voriconazole (VRC)-against Candida albicans were evaluated by the checkerboard microdilution method and time-killing test. The intensity of the interactions was determined by visual reading and the spectrophotometric method in a checkerboard assay, and the nature of the interactions was assessed by nonparametric models of FICI and ΔE. Colony counting and colorimetric viable detection methods (2,3-bis {2-methoxy-4-nitro-5-[(sulfenylamino) carbonyl]-2H-tetrazolium hydroxide} [XTT] reduction test) were used for evaluating the combination antifungal effects over time. Synergistic and indifferent effects were found for the combination of FK506 and azoles against azole-sensitive strains, while strong synergy was found against azole-resistant strains analyzed by FICI. The ΔE model gave more consistent results with FICI. The positive interactions were also confirmed by the time-killing test. Our findings suggest a potential role for combination therapy with calcineurin pathway inhibitors and azoles to augment activity against resistant C. albicans.
  Yan Li , Xiao-Dong Zhang , Li Sun , Min Xu , Wen-Guang Zhou and Xiao-Hui Liang
  A solid superacid catalyst was evaluated for the production of fatty acid methyl esters (FAMEs) from acid oil containing about 60 wt.% free fatty acids. It was demonstrated that View the MathML source ZrO2–TiO2/La3+ was an effective catalyst for simultaneous transesterification and esterification. The optimization of reaction parameters was performed, showing that maximum yield of above 90% could be obtained under the conditions that molar ratio of alcohol/oil was 15:1, catalyst amount was 5 wt.%, temperature was 200 °C and duration was 2 h. The catalyst was finally recycled and utilized for five times repeatedly with little loss in activity. The final products purified by molecular distillation were detected by GC–MS. The content of FAMEs reached 96.24%.
  Yan LI , Ping-Ping Gu and Xian-Shan Wang
  Currently, the study about hardware RTOS (Real Time Operating System) focus on implementation of the single module of RTOS by hardware, the overall hardware RTOS design and realization is seldom at home and abroad. So the hardware and software partitioning and implementing a hardware IP core of RTOS is worth further study. In this study, hardware-software partitioning of the hardware RTOS and the semaphore management are designed and implemented. The semaphore management is a program segment which runs frequently in operating system, the design solution that realize the semaphore management based on FPGA is put forward, in order to enhance the response capability of the RTOS. The storage structure, ECB (event control block) and mapping table are realized by on-chip registers; the semaphore management is realized by combinational logic circuit; both of them bring high speed to execute the semaphore system call function and P/V operations. The entire design is described by VHDL, simulated by the ISE 8.2 and realized on Xilinx's Virtex-II Pro Field Programmable Gate Array (FPGA) board. The result shows that realizing the semaphore management by hardware achieves good results in speeding up the RTOS.
  Yan Li , Shuai Cao , Zhiqiang Man and Huanhuan Chi
  In view of the low precision of the reconstruction image of Electrical Capacitance Tomography (ECT) at present. A new method of image reconstruction algorithm based on Chebyshev neural net works for Electrical Capacitance Tomography is proposed. This neural network not only expand the identification ability and learning adaptation of the neural network but also has a simple algorithm, a high speed convergence of learning process and excellent characteristics in the linear and nonlinear accurate approximation. The ECT image reconstruction experimental results show that the method can improve the reconstruction image quality and testify the effectiveness of the proposed method.
  Yongjie Zhai , Huiyuan Cui , Shilin Wang and Yan Li
  Based on the multivariate state estimation, a new condition monitoring methods for the generator set is presented to reduce the maintenance costs of power generation equipment. A new and improved matrix in memory is given. It can achieve a good coverage of the normal operation status of the milling system. When there is a large difference between the estimated value and the actual measurement value, the existence of the fault is indicated. Sliding window residual statistical methods is used to analyze the residuals. When the residual trend is beyond the set threshold value, the system generates the warning. The real-time data of power plant is used to verify the method. The simulation results show that this method can achieve early failure warning effectively.
  Xiaojuan Zhang , Yan Li , Wenqing Li and Wei Yang
  The diffusion approximation solution with one-point-source and two-point-source are investigated. In this theoretical model, considering a pencil beam incident on a semi-infinity scattering medium, the source function is simplified as one-point-source satisfying the dipole moment and two-point-source satisfying both the dipole and the quadrupole moments. The spatially resolved diffuse reflectance for the simplified sources are studied, which indicate that two-point-source approximation can more describe radiance close to the source and more depict the anisotropy radiance superior to one-point-source approximation.
  Yan Li , Xiao-Hua Yuan , Jing-Song Liu , Guo-Hua Zhu and An-Na Yuan
  According to Support Vector Machine (SVM) has low training speed and precision to deal with large-scale data in Electrical Capacitance Tomography (ECT) system, an improved algorithm that combined SVM with Choosing Segmentation is presented. In the algorithm, the large-scale samples are divided into selective blocks for one imaging unit, training and predicting them by SVM algorithm, respectively. Then all imaging units are combined into one image. Compared to sole SVM algorithm,the numerical experiments show that the mixed algorithm has higher precision and shorten the time of reconstruction images in ECT system at the same time.
  Peng Yu and Yan Li
  This study presents a novel approach for the prediction and detection of distributed denial of service (DDoS) attacks by using EAQPSO-SVM algorithm which is implemented through combining the improved Quantum-behaved Particle Swarm Optimization (QPSO) algorithm with Support Vector Machine (SVM) theory. In order to improve the global searching performance of the classical QPSO algorithm for avoiding falling into local extreme value point, the Evolution Speed Factor (ESF) and Aggregation Degree Factor (ADF) were introduced in the EAQPSO-SVM algorithm to establish a binary relation function for correcting the self-adaptive expansion-contraction coefficient. Furthermore, a hybrid entropies strategy is proposed to identify the potential DDoS attacks by comparing the mean value entropy with average alarm threshold. Simulation results demonstrate that the proposed method remarkably improves the abilities of prediction and detection of DDoS attacks. Meanwhile, a novel framework of performance evaluation further proves that the proposed algorithm has better generalization ability and superior performance in terms of less algorithm execution time, average iterations, average relative variance and root mean square error.
  Peng Han , Jinkuan Wang , Yan Li and Yinghua Han
  The large adoption of hybrid renewable energy systems and the increasing power requirements of residential loads brings significant challenges to the construction and operation of the micro-grid systems. In this study, the agent-based modelling methodology is proposed to proper model and assess the discarded energy in the micro-grid. With the integration of the agent-based modelling and the system dynamic approach, the proposed approach contributes to a micro-grid model that is hierarchically constituted by micro-grid management layer and component layer. The system dynamics modelling is adopted in the management layer to model the energy consumption in the micro-grid while the object-oriented agent-based modelling is adopted to generate the main components. Furthermore, this study also proposed a comprehensive micro-grid operation simulation system, through which the observation and assessment of the proposed model can be achieved. Monte Carlo simulations show that the model and system can comprehensively reflect the energy consumption and generation in the micro-grid, providing preferred quantitate assessment for the micro-grid operation economical-efficiency and security with various HRES penetrations and time scales. The proposed methodology of this study will be beneficial for the study of the micro-grid discarded energy assessment and can be further utilized to the energy management policy evaluation, electricity consumption prediction and HRES deployment optimization.
  Emeka Eze Joshua Iweala , Fang-Fang Liu , Rong-Rong Cheng , Yan Li , Conrad Asotie Omonhinmin and Ying-Jun Zhang
  This study was designed to screen different extracts of 15 commonly consumed Nigerian food plants for anti-cancer and free radical scavenging activities. Leaves, seeds or fruits of the plants were each successively extracted with n-hexane, dichloromethane, ethanol and water. The cytotoxic activity of each of the extracts was tested against human myeloid leukemia (HL-60), human hepatocellular carcinoma (SMMC-7721), human lung carcinoma (A-549), human breast adenocarcinoma (MCF-7) and colon cancer (SW480) cell lines using Cisplatin as standard. The free radical scavenging activities of the extracts against 1,1-diphenyl-2-picrylhydrazyl (DPPH) were also determined. The dichloromethane extract of Vernonia amygdalina leaves (VA-D) showed the strongest cytotoxic activity against all the cancer cell lines with IC50 range of 5.85-8.84 μg mL-1. The dichloromethane extract of Gongronema latifolium leaves (GL-D) showed the highest activity against A-549 and MCF-7 with IC50 of 9.57 and 6.51 μg mL-1, respectively, while Piper guineense leaves (PG-D) exhibited the highest activity against HL-60 with IC50 of 3.62 μg mL-1. The other extracts were inactive against the cancer cell lines. The ethanolic extract of Sesamum indicum leaves (SI-E) and Mucuna pruriens seeds (MP-E) showed the highest free radical scavenging activity with SC50 of 6.8 and 7.3x10-2 mg mL-1, respectively. Other extracts of some of the food plant samples showed varying free radical scavenging activities. The results from this study suggest that some of the food plants screened may possess anti-cancer and antioxidant properties.
  Jianhua Chen , Lin Yang , Dengtang Liu , Donghong Cui , Shunying Yu , Yan Li , Haisu Wu , Ying Yue , Yongyong Shi and Yifeng Xu
  The Metabolic Syndrome (MetS) could significantly increase the risk of morbidity and mortality from type II diabetes and cardiovascular disease. We carried out a systemical study to investigate the potential drug targets for effective treatment of clozapine-induced MetS. In our study, the differentially-expressed miRNAs (DERs) between schizophrenia patients with MetS and without MetS after the treatment of clozapine were identified. Target genes of these miRNAs were then retrieved from two miRNA databases (miRecods and miRTarBase) to identify the underlying mechanisms involved in the development of MetS. Interactors of the target genes were identified and a network was constructed using Osprey. Functional enrichment analysis was performed for all the genes in the network with DAVID (Database for Annotation, Visualization and Integrated Discovery). The results revealed that 3 DERs including Hsa-miR-330-3p (p = 0.00934), has-miR-18a (p = 0.001686) and has-miR-106b (p = 0.007531)were identified. In total, 4 target genes (E2F1, CTGF, ESR1 and ITCH) shared by both databases were picked out. What’s more, 8 significant pathways were revealed in the interaction network and the most significant pathway was positive regulation of macromolecule metabolic process (FDR = 1.80E-15). In conclusion, the 3 identified miRNAs might be the potential targets for treatment of MetS. And the results of our study provide ways to monitor the progression of MetS (e.g., serum levels of proteins), predict the outcome (e.g., polymorphisms) and even block the emergence of MetS.
  Yan Li , Chao Sun , Peng Pu and Renli Qi
  This study investigated the effect of microalgae oil on tissue Fatty Acid (FA) profile of broilers. Through analysis, it was discovered that microalgae oil altered the FA composition and concentration during the development of different organs. In liver, microalgae oil increased the concentration of C22:6 (High Polyunsaturated Fatty Acids, ΣHUFA) but decreased the concentration of C18:1 (Monounsaturated Fatty Acids, ΣMUFA) during the initial growth period while at a later stage, there was a significant increase of C18:1 (ΣMUFA), C22:6 (ΣHUFA) and C20:4 (ΣHUFA) and a decrease of C18:2 (Polyunsaturated Fatty Acids, ΣPUFA). Moreover, after the withdrawal of microalgae oil, there was a continued effect on C22:6 for 1 week. Liver exhibited a similar change in concentration of FA as the breast, leg muscle and brain, especially at the later phase. Therefore, researchers can conclude that microalgae oil alters tissue FA composition and concentration during maturation which is an important period for sustained development and maintenance of FA. Unfortunately, pro-longed feeding of the broilers with microalgaee oil diets did not result in the accumulation of Docosahexaenoic Acid (DHA) in tissues.
  Mingwang Zhang , Mingzhou Li , Long Jin , Yan Li and Xuewei Li
  Tibetan pig is an endangered plateau type pig breed which distributed mainly in Qinghai-Tibetan Plateau. In present study, researchers analyzed 218 prior published partial mitochondrial D-loop sequences (415 bp) by using phylogenetic, network, mismatch distribution and Analysis of Molecular Variance (AMOVA) analysis to clarify the population differentiation and explore the relationships among populations from different geographical locations of Tibetan pigs. The results revealed a total of 43 haplotypes in 218 samples from seven Tibetan pig populations in which only one common Haplotype (H1) was shared by the seven populations. Haplotype diversity was high (0.889) whereas nucleotide diversity among all individuals was low (0.00534). It is notable that Hezuo Tibetan pigs have 19 unique haplotypes in total 24 haplotypes of 53 individuals with the highest nucleotide diversity (0.00765). Bayesian tree and median joining network procedures carried out on the data showed that seven Tibetan pig haplotypes were essentially indistinguishable except some unique haplotypes from Hezuo. The AMOVA analysis indicated that the genetic variation mainly occurred within populations (85.41%) but variance among populations was only 14.59%. The unimodal mismatch distribution of haplotypes, together with significant negative values of Fu’s FS and negative values of Tajima’s D suggest that a recent population expansion of Tibetan pig has been occurred in Diqing, Hezuo and total population.
  Zhihui Hao , Yongda Zhao , Baohan Qu , Haoting Wu , Lihua Hao , Zhaopeng Ding , Fenfang Yang and Yan Li
  The objective of this study was to campare different pharmacokinetic parameters of a locally manufactured (Tulathromycin Injection, CONTINENT, China) and reference (Draxxin, Pfizer, USA) formulation of tulathromycin 2.5 mg injection after intramuscular administration of a single dose. Twelve pigs were randomly allocated to two treatment groups. Blood samples were collected by venipuncture of the jugular vein or anterior vena cava, plasma samples were analyzed by High-Performance Liquid Chromatography (HPLC) with tandem mass spectrometry detection (LC-MS/MS) using ESI. Mean puls or minus Standard Deviation (SD) of peak plasma Concentration (Cmax) Area Under the serum Concentration-time curve (AUC0-t), Area Under the serum Concentration-time curve (AUCinf), serum concentration half-life (t1/2) were 4.32±1.52 and 5.86±1.28 μg mL-1, 3.98±1.63 and 4.24±1.30 μgh mL-1, 4.04±1.67 and 4.65±2.01 μgh mL-1, 83.55±12.84 and 79.25±10.64 h for the locally manufactured (tested) and reference formulation, respectively. The 90% confidence intervals of the mean of the difference between log-transformed values for AUC0-360, AUC0-∞ and Cmax were within the bioequivalence accepted range of 80-125%. The results indicate that tulathromycin was rapidly absorbed, eliminated slowly and highly bioavailable following a single dose which make tulathromycin likely to be effective in swine.
  Mingwang Zhang , Guohua Yu , Dingqi Rao , Yimei Huang , Junxing Yang and Yan Li
  The taxonomic status of red knobby newt (Tylototriton shanjing) is under dispute. Molecular phylogenetic tree of Tylototriton verrucosus group was reconstructed based on 753 bp of partial mitochondrial cyt b gene sequence to determine species boundaries among the species in T. verrucosus group. The phylogeny result indicates that four major clades (clade I-IV) can be distinguished within Tylototriton verrucosus group. Clade I and IV consist of T. taliangensis and T. kweichowensis, respectively. Clade II consists of samples of T. shanjing derived from Yunnan of China, a form that researchers resurrect from its synonym under T. verrucosus. T. verrucosus haplotypes from Shan State of Myanmar and pet trade formed clade III. All populations of T. shanjing and T. verrucosus formed strongly supported (PP = 1.0) reciprocal monophyletic groups. The average uncorrected pairwise genetic distance (p-distance) of cyt b between these four clades ranges from 0.060-0.089 which is obviously higher than within these four major clades (0.001-0.014). Researchers propose that the T. shanjing should be a valid species rather than synonym of T. verrucosus.
  Yan Li and Xueqing Yue
  Foreign language teaching as a complex educational activity needs original language as the teaching resources. In foreign language teaching activities, English newspapers with its fast update rate, inclusiveness and the authenticity of the language has a more obvious advantages than traditional teaching materials. Foreign language press material as a new teaching mode has opened up a new path for the foreign language classroom activities and plays a great role in promoting foreign language teaching.
  Suxiang Tong , Shur-Wern Wang Chern , Yan Li , Mark A. Pallansch and Larry J. Anderson
  We have developed a set of reverse transcription-PCR assays for the detection and identification of known and novel paramyxoviruses in clinical specimens. Primers were designed from the conserved motifs of the polymerase pol gene sequences to detect members of the Paramyxovirinae or Pneumovirinae subfamily or groups of genera within the Paramyxovirinae subfamily. The consensus-degenerate hybrid oligonucleotide primer design and seminested or nested PCR assay design were used to enhance the breadth of reactivity and sensitivity of the respective assays. Using expressed RNA and 10-fold dilution series of virus-infected tissue culture isolates from different members of the family or genera, these assays were able to detect on average between 100 and 500 copies of template RNA. The assays were specific to the respective group of genera or subfamily viruses. This set of primers enhances our ability to look for novel viruses in outbreaks and diseases of unknown etiology.
  Zhaogang Sun , Yanjie Chao , Xuxia Zhang , Jianyuan Zhang , Yan Li , Yunqing Qiu , Yi Liu , Lihui Nie , Aizhen Guo and Chuanyou Li
  Thirteen extensively drug-resistant tuberculosis isolates which were highly resistant to a broad spectrum of antituberculosis drugs were identified from 1,926 clinical isolates in China. They had highly diverse mycobacterial interspersed repetitive-unit-variable-number tandem-repeat patterns. Most, but not all, of the drug target genes had mutations contributing to resistance to the corresponding drug.
  Yan Li , Hui Huang and Yue-Wei Guo
  A new norsesquiterpene, sinunorcaryophyllenol (1), together with four known related terpenoids (2-5) have been isolated from Hainan soft coral Sinularia sp. The structure of the new compound was elucidated on the basis of detailed spectroscopic data analysis and by comparison with related model compounds.
  Yan Li
  The activity of anti-oxidant enzymes (Superoxide dismutase (SOD), Peroxidase (POD), Catalase (CAT) and parameters of oxidative stress malondialdehyde (MDA) of shoots were investigated in S. sieb naturally salt-resistant halophyte. The seedlings of S. sieb were treated with varying (0, 80, 160 and 240 mM) NaCl stress. The results showed that NaCl played an important role in growth of S. sieb. It made obviously promotion of certain NaCl concentration to growth of S. sieb, the seeflings of S. sieb grew best under 80 mM salt stress. MDA concentration of S. sieb obviously decreased under 80 mM salt stress then increased with salt concentration increased. The activities of SOD, POD and CAT increased with the increase of the concentration of NaCl in S. sieb. The salt tolerance of this halophyte under salt stress condition are probably due to its ability to exhibit high SOD, POD and CAT enzyme activities and Soluble Sugar (SS) concentration.
  Yan Li , Marpadga A. Reddy , Feng Miao , Narkunaraja Shanmugam , Jiing-Kuan Yee , David Hawkins , Bing Ren and Rama Natarajan
  Nuclear factor κ-B (NF-κB)-regulated inflammatory genes, such as TNF-α (tumor necrosis factor-α), play key roles in the pathogenesis of inflammatory diseases, including diabetes and the metabolic syndrome. However, the nuclear chromatin mechanisms are unclear. We report here that the chromatin histone H3-lysine 4 methyltransferase, SET7/9, is a novel coactivator of NF-κB. Gene silencing of SET7/9 with small interfering RNAs in monocytes significantly inhibited TNF-α-induced inflammatory genes and histone H3-lysine 4 methylation on these promoters, as well as monocyte adhesion to endothelial or smooth muscle cells. Chromatin immunoprecipitation revealed that SET7/9 small interfering RNA could reduce TNF-α-induced recruitment of NF-κB p65 to inflammatory gene promoters. Inflammatory gene induction by ligands of the receptor for advanced glycation end products was also attenuated in SET7/9 knockdown monocytes. In addition, we also observed increased inflammatory gene expression and SET7/9 recruitment in macrophages from diabetic mice. Microarray profiling revealed that, in TNF-α-stimulated monocytes, the induction of 25% NF-κB downstream genes, including the histone H3-lysine 27 demethylase JMJD3, was attenuated by SET7/9 depletion. These results demonstrate a novel role for SET7/9 in inflammation and diabetes.
  Ya-Hui Chi , Kerstin Haller , Michael D. Ward , O. John Semmes , Yan Li and Kuan-Teh Jeang
  Mitotic arrest deficiency protein 1 (Mad1) is associated with microtubule-unattached kinetochores in mitotic cells and is a component of the spindle assembly checkpoint (SAC). Here, we have studied the phosphorylation of Mad1 and mapped using liquid chromatography-tandem mass spectrometry several phosphorylated amino acids in this protein. One phosphorylated residue, Thr680, was characterized to be important for the kinetochore localization of Mad1 and its SAC function. We also found that in mitotic cells Mad1 co-immunoprecipitated with Plk1. Depletion of cellular Plk1 using small interfering RNAs and inhibition of the kinase activity of Plk1 using a kinase-dead mutant or a small molecule inhibitor attenuated Mad1 phosphorylation and its association with kinetochores. Collectively, these findings indicate mechanistic roles contributed by protein phosphorylation and Plk1 to theaSAC activity of Mad1.
  Wei Zhou , Jinling Yang , Yan Li , An Ji , Fuhua Yang and Yude Yu
  The mechanical properties and fracture behavior of silicon nitride (SiNx) thin film fabricated by plasma-enhanced chemical vapor deposition is reported. Plane-strain moduli, prestresses, and fracture strengths of silicon nitride thin films deposited both on a bare Si substrate and on a thermally oxidized Si substrate were extracted using bulge testing combined with a refined load-deflection model of long rectangular membranes. The plane-strain moduli and prestresses of SiNx thin films have little dependence on the substrates, that is, for the bare Si substrate, they are 133 ± 19 GPa and 178 ± 22 MPa, respectively, while for the thermally oxidized substrate, they are 140 ± 26 GPa and 194 ± 34 MPa, respectively. However, the fracture strength values of SiNx films grown on the two substrates are quite different, i.e., 1.53 ± 0.33 GPa and 3.08 ± 0.79 GPa for the bare Si substrate and the oxidized Si substrate, respectively. The reference stresses were computed by integrating the local stress of the membrane at the fracture over the edge, surface, and volume of the specimens and fitted with the Weibull distribution function. For SiNx thin film produced on the bare Si substrate, the volume integration gave a significantly better agreement between data and model, implying that the volume flaws are the dominant fracture origin. For SiNx thin film grown on the oxidized Si substrate, the fit quality of surface and edge integration was significantly better than the volume integration, and the dominant surface and edge flaws could be caused by buffered HF attacking the SiNx layer during SiO2 removal.
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