期刊文献+
共找到428篇文章
< 1 2 22 >
每页显示 20 50 100
Effects of interleukin-10 treated macrophages on bone marrow mesenchymal stem cells via signal transducer and activator of transcription 3 pathway
1
作者 Meng-Hao Lyu Ce Bian +3 位作者 Yi-Ping Dou Kang Gao Jun-Ji Xu Pan Ma 《World Journal of Stem Cells》 SCIE 2024年第5期560-574,共15页
BACKGROUND Alveolar bone defects caused by inflammation are an urgent issue in oral implant surgery that must be solved.Regulating the various phenotypes of macrophages to enhance the inflammatory environment can sign... BACKGROUND Alveolar bone defects caused by inflammation are an urgent issue in oral implant surgery that must be solved.Regulating the various phenotypes of macrophages to enhance the inflammatory environment can significantly affect the progression of diseases and tissue engineering repair process.AIM To assess the influence of interleukin-10(IL-10)on the osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)following their interaction with macrophages in an inflammatory environment.METHODS IL-10 modulates the differentiation of peritoneal macrophages in Wistar rats in an inflammatory environment.In this study,we investigated its impact on the proliferation,migration,and osteogenesis of BMSCs.The expression levels of signal transducer and activator of transcription 3(STAT3)and its activated form,phos-phorylated-STAT3,were examined in IL-10-stimulated macrophages.Subsequently,a specific STAT3 signaling inhibitor was used to impede STAT3 signal activation to further investigate the role of STAT3 signaling.RESULTS IL-10-stimulated macrophages underwent polarization to the M2 type through substitution,and these M2 macrophages actively facilitated the osteogenic differentiation of BMSCs.Mechanistically,STAT3 signaling plays a crucial role in the process by which IL-10 influences macrophages.Specifically,IL-10 stimulated the activation of the STAT3 signaling pathway and reduced the macrophage inflammatory response,as evidenced by its diminished impact on the osteogenic differentiation of BMSCs.CONCLUSION Stimulating macrophages with IL-10 proved effective in improving the inflammatory environment and promoting the osteogenic differentiation of BMSCs.The IL-10/STAT3 signaling pathway has emerged as a key regulator in the macrophage-mediated control of BMSCs’osteogenic differentiation. 展开更多
关键词 MACROPHAGES INTERLEUKIN-10 Bone marrow mesenchymal stem cells Signal transducer and activator of transcription 3 Inflammatory response
下载PDF
Combined Digital Electronic Current and Voltage Transducer 被引量:2
2
作者 段雄英 邹积岩 +1 位作者 廖敏夫 张可卫 《Journal of Shanghai University(English Edition)》 CAS 2002年第1期79-84,共6页
A high performance current and voltage measurement system has been developed in power system. The system is composed of two parts: one current measurement element and one voltage measurement element. A Rogowski coil ... A high performance current and voltage measurement system has been developed in power system. The system is composed of two parts: one current measurement element and one voltage measurement element. A Rogowski coil and a capacitive voltage divider are used respectively for the line current and voltage measurements. Active electronic components are used to modulate signal, and power supply for these components is drawn from power line via an auxiliary current transformer. Measurement signal is transmitted by optical fibers, which is resistant to electromagnetic induction and noise. With careful design and the use of digital signal processing technology, the whole system can meet 0.5% accuracy for metering and provides large dynamic range coupled with good accuracy for protective relaying use. 展开更多
关键词 electronic current transducer (ECT) electronic voltage transducer (EVT) Rogowski coil capacitive voltage divider (CVD) optical fiber.
下载PDF
Diffusion-weighted magnetic resonance imaging reflects activation of signal transducer and activator of transcription 3 during focal cerebral ischemia/reperfusion 被引量:1
3
作者 Wen-juan Wu Chun-juan Jiang +2 位作者 Zhui-yang Zhang Kai Xu Wei Li 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第7期1124-1130,共7页
Signal transducer and activator of transcription(STAT)is a unique protein family that binds to DNA,coupled with tyrosine phosphorylation signaling pathways,acting as a transcriptional regulator to mediate a variety ... Signal transducer and activator of transcription(STAT)is a unique protein family that binds to DNA,coupled with tyrosine phosphorylation signaling pathways,acting as a transcriptional regulator to mediate a variety of biological effects.Cerebral ischemia and reperfusion can activate STATs signaling pathway,but no studies have confirmed whether STAT activation can be verified by diffusion-weighted magnetic resonance imaging(DWI)in rats after cerebral ischemia/reperfusion.Here,we established a rat model of focal cerebral ischemia injury using the modified Longa method.DWI revealed hyperintensity in parts of the left hemisphere before reperfusion and a low apparent diffusion coefficient.STAT3 protein expression showed no significant change after reperfusion,but phosphorylated STAT3 expression began to increase after 30 minutes of reperfusion and peaked at 24 hours.Pearson correlation analysis showed that STAT3 activation was correlated positively with the relative apparent diffusion coefficient and negatively with the DWI abnormal signal area.These results indicate that DWI is a reliable representation of the infarct area and reflects STAT phosphorylation in rat brain following focal cerebral ischemia/reperfusion. 展开更多
关键词 nerve regeneration cerebral ischemia/repe(fusion magnetic resonance imaging diffusion weighted imaging signal transducer and activator of transcription 3 phosphorylated signal transducer and activator of transcription 3 apparent diffusion coefficient relative apparentdiffusion coefficient IMMUNOHISTOCHEMISTRY western blot assay neural regeneration
下载PDF
Genetic Algorithm-Based Estimation of Nonlinear Transducer
4
作者 庄哲民 黄惟一 《Journal of Southeast University(English Edition)》 EI CAS 2001年第1期4-7,共4页
This paper describes an innovative, genetic algorithm based inverse model of nonlinear transducer. In the inverse modeling, using a genetic algorithm, the unknown coefficients of the model are estimated accurately. T... This paper describes an innovative, genetic algorithm based inverse model of nonlinear transducer. In the inverse modeling, using a genetic algorithm, the unknown coefficients of the model are estimated accurately. The simulation results indicate that this technique provides greater flexibility and suitability than the existing methods. It is very easy to modify the nonlinear transducer on line. Thus the method improves the transducer's accuracy. With the help of genetic algorithm (GA), the model coefficients' training are less likely to be trapped in local minima than traditional gradient based search algorithms. 展开更多
关键词 nonlinear transducer genetic algorithm inverse model
下载PDF
Regulation and function of signal transducer and activator of transcription 3 被引量:23
5
作者 Qian-Rong Qi Zeng-Ming Yang 《World Journal of Biological Chemistry》 CAS 2014年第2期231-239,共9页
Signal transducer and activator of transcription 3(STAT3), a member of the STAT family, is a key regulator of many physiological and pathological processes. Significant progress has been made in understanding the tran... Signal transducer and activator of transcription 3(STAT3), a member of the STAT family, is a key regulator of many physiological and pathological processes. Significant progress has been made in understanding the transcriptional control, posttranslational modification, cellular localization and functional regulation of STAT3. STAT3 can translocate into the nucleus and bind to specific promoter sequences, thereby exerting transcriptional regulation. Recent studies have shown that STAT3 can also translocate into mitochondria, participating in aerobic respiration and apoptosis. In addition, STAT3 plays an important role in inflammation and tumorigenesis by regulating cell proliferation, differentiation and metabolism. Conditional knockout mouse models make it possible to study the physiological function of STAT3 in specific tissues and organs. This review summarizes the latest advances in the understanding of the expression, regulation and function of STAT3 in physiological and tumorigenic processes. 展开更多
关键词 SIGNAL transducer and ACTIVATOR of TRANSCRIPTION 3 PHOSPHORYLATION ACETYLATION SIGNAL pathway Tumor
下载PDF
Modeling and finite element analysis of transduction process of electromagnetic acoustic transducers for nonferromagnetic metal material testing 被引量:13
6
作者 郝宽胜 黄松岭 +2 位作者 赵伟 段汝娇 王珅 《Journal of Central South University》 SCIE EI CAS 2011年第3期749-754,共6页
Facing the problems lack of considering the non-uniform distribution of the static bias magnetic field and computing the panicle displacements in the simulation model of electromagnetic acoustic transducer (EMAT), a... Facing the problems lack of considering the non-uniform distribution of the static bias magnetic field and computing the panicle displacements in the simulation model of electromagnetic acoustic transducer (EMAT), a multi-field coupled model was established and the finite element method (FEM) was presented to calculate the entire transduction process. The multi-field coupled model included the static magnetic field, pulsed eddy current field and mechanical field. The FEM equations of the three fields were derived by Garlerkin FEM method. Thus, the entire transduction process of the EMAT was calculated through sequentially coupling the three fields. The transduction process of a Lamb wave EMAT was calculated according to the present model and method. The results show that, by the present method, it is valid to calculate the particle displacement under the given excitation signal and non-uniformly distributed static magnetic field. Calculation error will be brought about if the non-uniform distribution of the static bias magnetic field is neglected. 展开更多
关键词 metal material nondestructive testing electromagnetic acoustic transducer multi-field coupling Garlerkin method finite element
下载PDF
Signal transducer and activator of transcription 3 promotes the Warburg effect possibly by inducing pyruvate kinase M2 phosphorylation in liver precancerous lesions 被引量:8
7
作者 Yang-Hui Bi Wen-Qi Han +4 位作者 Ruo-Fei Li Yun-Jiao Wang Zun-Shu Du Xue-Jiang Wang Ying Jiang 《World Journal of Gastroenterology》 SCIE CAS 2019年第16期1936-1949,共14页
BACKGROUND Study shows that signal transducer and activator of transcription 3(STAT3) can increase the Warburg effect by stimulating hexokinase 2 in breast cancer and upregulate lactate dehydrogenase A and pyruvate de... BACKGROUND Study shows that signal transducer and activator of transcription 3(STAT3) can increase the Warburg effect by stimulating hexokinase 2 in breast cancer and upregulate lactate dehydrogenase A and pyruvate dehydrogenase kinase 1 in myeloma. STAT3 and pyruvate kinase M2(PKM2) can also be activated and enhance the Warburg effect in hepatocellular carcinoma. Precancerous lesions are critical to human and rodent hepatocarcinogenesis. However, the underlying molecular mechanism for the development of liver precancerous lesions remains unknown. We hypothesized that STAT3 promotes the Warburg effect possibly by upregulating p-PKM2 in liver precancerous lesions in rats.AIM To investigate the mechanism of the Warburg effect in liver precancerous lesions in rats.METHODS A model of liver precancerous lesions was established by a modified Solt-Farber method. The liver pathological changes were observed by HE staining and immunohistochemistry. The transformation of WB-F344 cells induced with Nmethyl-N'-nitro-N-nitrosoguanidine and hydrogen peroxide was evaluated by the soft agar assay and aneuploidy. The levels of glucose and lactate in the tissue and culture medium were detected with a spectrophotometer. The protein levels of glutathione S-transferase-π, proliferating cell nuclear antigen(PCNA), STAT3,and PKM2 were examined by Western blot and immunofluorescence.RESULTS We found that the Warburg effect was increased in liver precancerous lesions in rats. PKM2 and p-STAT3 were upregulated in activated oval cells in liverprecancerous lesions in rats. The Warburg effect, p-PKM2, and p-STAT3 expression were also increased in transformed WB-F344 cells. STAT3 activation promoted the clonal formation rate, aneuploidy, alpha-fetoprotein expression,PCNA expression, G1/S phase transition, the Warburg effect, PKM2 phosphorylation, and nuclear translocation in transformed WB-F344 cells.Moreover, the Warburg effect was inhibited by stattic, a specific inhibitor of STAT3, and further reduced in transformed WB-F344 cells after the intervention for PKM2.CONCLUSION The Warburg effect is initiated in liver precancerous lesions in rats. STAT3 activation promotes the Warburg effect by enhancing the phosphorylation of PKM2 in transformed WB-F344 cells. 展开更多
关键词 WARBURG effect Hepatic PROGENITOR cell Signal transducer and activator of transcription 3 PYRUVATE kinase M2 LIVER PRECANCEROUS lesion
下载PDF
OPTIMAL DESIGN OF A 6-AXIS FORCE TRANSDUCER BASED ON STEWART PLATFORM RELATED TO SENSITIVITY ISOTROPY 被引量:10
8
作者 JinZhenlin GaoFenfl GaoFeng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2003年第2期146-148,共3页
The design method of a 6-axis force robot's transducer based on the Stewartplatform is detailed. For this purpose, the sensitivity isotropy evaluation criteria of thetransducer are defined, and by the aid of compu... The design method of a 6-axis force robot's transducer based on the Stewartplatform is detailed. For this purpose, the sensitivity isotropy evaluation criteria of thetransducer are defined, and by the aid of computer, the relationships between the criteria and theparameters of all the transducers based on the Stewart platform are investigated within thegeometric model of the solution space, which can provide the theoretical background for the optimalconstruction design of the 6-axis force transducer related to the sensitivity isotropy. 展开更多
关键词 6-axis force robot's transducer optimal construction design stewartplatform sensitivity isotropy
下载PDF
Downregulation of signal transducer and activator of transcription 3 by sorafenib:A novel mechanism for hepatocellular carcinoma therapy 被引量:9
9
作者 Man-Hsin Hung Wei-Tien Tai +1 位作者 Chung-Wai Shiau Kuen-Feng Chen 《World Journal of Gastroenterology》 SCIE CAS 2014年第41期15269-15274,共6页
Hepatocellular carcinoma is one of the most common cancers worldwide,and a leading cause of cancer-related death.Owing to unsatisfactory clinical outcomes under the current standard of care,there is a need to search f... Hepatocellular carcinoma is one of the most common cancers worldwide,and a leading cause of cancer-related death.Owing to unsatisfactory clinical outcomes under the current standard of care,there is a need to search for and identify novel and potent therapeutic targets to improve patient outcomes.Sorafenib is the first and only approved targeted therapy for the treatment of hepatocellular carcinoma.Besides functioning as a multiple tyrosine kinase,sorafenib also acts via a kinase-independent mechanism to target signal transducer and activator of transcription 3(STAT3) signaling in hepatocellular carcinoma cells.STAT3 is a key regulator of inflammation,cell survival,and tumorigenesis of liver cells,and the high percentage of hepatocellular carcinoma cells with constitutively active STAT3 justifies targeting it for the development of novel therapeutics.Sorafenib inactivates STAT3 and STAT3-related signaling by inducing a conformational change in and releasing the autoinhibition of Src homology region 2 domaincontaining phosphatase-1.This phosphatase negatively regulates STAT3 activity,which leads to the subsequent apoptosis of cancer cells.The novel anti-cancer property of sorafenib will be discussed in this review,not only adding information regarding its mechanism of action but also providing an innovative approach for the development of cancer therapeutics in the future. 展开更多
关键词 Hepatocellular carcinoma SORAFENIB Signal transducer and activator of transcription 3 Target therapy Kinase-independent
下载PDF
Ultrasound Imaging of Pipeline Crack Based on Composite Transducer Array 被引量:8
10
作者 Shou-Peng Song Ying-Jie Ni 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第5期25-34,共10页
Cracks, especially small cracks are di cult to be detected in oil and gas transportation pipelines buried underground or covered with layers of material by using the traditional ultrasonic inspection techniques. There... Cracks, especially small cracks are di cult to be detected in oil and gas transportation pipelines buried underground or covered with layers of material by using the traditional ultrasonic inspection techniques. Therefore, a new com?posite ultrasonic transducer array with three acoustic beam incidence modes is developed. The space model of the array is also established to obtain the defect reflection point location. And the crack ultrasound image is thus formed through a series of small cubical elements expanded around the point locations by using the projection of binariza?tion values extracted from the received ultrasonic echo signals. Laboratory experiments are performed on a pipeline sample with di erent types of cracks to verify the e ectiveness and performance of the proposed technique. From the image, the presence of small cracks can be clearly observed, in addition to the sizes and orientations of the cracks. The proposed technique can not only inspect common flaws, but also detect cracks with various orientations, which is helpful for defect evaluation in pipeline testing. 展开更多
关键词 Composite transducer array Ultrasound imaging CRACK NDT&E
下载PDF
Excitation and Detection of Shear Horizontal Waves with Electromagnetic Acoustic Transducers for Nondestructive Testing of Plates 被引量:13
11
作者 MA Qingzeng JIAO Jingpin +3 位作者 HU Ping ZHONG Xi WU Bin HE Cunfu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2014年第2期428-436,共9页
The fundamental shear horizontal(SH0) wave has several unique features that are attractive for long-range nondestructive testing(NDT). By a careful design of the geometric configuration, electromagnetic acoustic t... The fundamental shear horizontal(SH0) wave has several unique features that are attractive for long-range nondestructive testing(NDT). By a careful design of the geometric configuration, electromagnetic acoustic transducers(EMATs) have the capability to generate a wide range of guided wave modes, such as Lamb waves and shear-horizontal(SH) waves in plates. However, the performance of EMATs is influenced by their parameters. To evaluate the performance of periodic permanent magnet(PPM) EMATs, a distributed-line-source model is developed to calculate the angular acoustic field cross-section in the far-field. Numerical analysis is conducted to investigate the performance of such EMATs with different geometric parameters, such as period and number of magnet arrays, and inner and outer coil widths. Such parameters have a great influence on the directivity of the generated SH0 waves that arises mainly in the amplitude and width of both main and side lobes. According to the numerical analysis, these parameters are optimized to obtain better directivity. Optimized PPM EMATs are designed and used for NDT of strip plates. Experimental results show that the lateral boundary of the strip plate has no perceivable influence on SHO-wave propagation, thus validating their used in NDT. The proposed model predicts the radiation pattern ofPPM EMATs, and can be used for their parameter optimization. 展开更多
关键词 electromagnetic acoustic transducers shear-horizontal waves strip plate nondestructive testing
下载PDF
Simulation of thermal field induced by concave spherical transducer in multi-layer media 被引量:5
12
作者 丁亚军 钱盛友 廖志远 《Journal of Central South University》 SCIE EI CAS 2013年第11期3166-3170,共5页
High intensity focused ultrasound(HIFU)therapy is an effective method in clinical treatment of tumors,in order to explore the bio-heat conduction mechanism of in multi-layer media by concave spherical transducer,tempe... High intensity focused ultrasound(HIFU)therapy is an effective method in clinical treatment of tumors,in order to explore the bio-heat conduction mechanism of in multi-layer media by concave spherical transducer,temperature field induced by this kind of transducer in multi-layer media will be simulated through solving Pennes equation with finite difference method,and the influence of initial sound pressure,absorption coefficient,and thickness of different layers of biological tissue as well as thermal conductivity parameter on sound focus and temperature distribution will be analyzed,respectively.The results show that the temperature in focus area increases faster while the initial sound pressure and thermal conductivity increase.The absorption coefficient is smaller,the ultrasound intensity in the focus area is bigger,and the size of the focus area is increasing.When the thicknesses of different layers of tissue change,the focus position changes slightly,but the sound intensity of the focus area will change obviously.The temperature in focus area will rise quickly before reaching a threshold,and then the temperature will keep in the threshold range. 展开更多
关键词 multi-layer media concave spherical transducer high intensity focused ultrasound thermal field
下载PDF
Design of a hexagonal air-coupled capacitive micromachined ultrasonic transducer for air parametric array 被引量:5
13
作者 Xiaoli Zhang Hui Zhang Dachao Li 《Nanotechnology and Precision Engineering》 CAS CSCD 2021年第1期26-35,共10页
An air parametric array can generate a highly directional beam of audible sound in air,which has a wide range of applications in targeted audio delivery.Capacitive micromachined ultrasonic transducer(CMUTs)have great ... An air parametric array can generate a highly directional beam of audible sound in air,which has a wide range of applications in targeted audio delivery.Capacitive micromachined ultrasonic transducer(CMUTs)have great potential for air-coupled applications,mainly because of their low acoustic impedance.In this study,an air-coupled CMUT array is designed as an air parametric array.A hexagonal array is proposed to improve the directivity of the sound generated.A finite element model of the CMUT is established in COMSOL software to facilitate the choice of appropriate structural parameters of the CMUT cell.The CMUT array is then fabricated by a wafer bonding process with high consistency.The performances of the CMUT are tested to verify the accuracy of the finite element analysis.By optimizing the component parameters of the bias-T circuit used for driving the CMUT,DC and AC voltages can be effectively applied to the top and bottom electrodes of the CMUT to provide efficient ultrasound transmission.Finally,the prepared hexagonal array is successfully used to conduct preliminary experiments on its application as an air parametric array. 展开更多
关键词 Capacitive micromachined ultrasonic transducer Air–coupled Wafer bonding process Bias-T circuit optimization Parametric array
下载PDF
Hepatitis C Virus non-structural 5A abrogates signal transducer and activator of transcription-1 nuclear translocation induced by IFN-α through dephosphorylation 被引量:4
14
作者 Guo-Zhong Gong Jie Cao Yong-Fang Jiang Yang Zhou Bo Liu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第30期4080-4084,共5页
AIM: To study the effect of Hepatitis C virus nonstructural 5A (HCV NSSA) on IFNα induced signal transducer and activator of transcription-1 (STAT1) phosphorylation and nuclear translocation.METHODS: Expression... AIM: To study the effect of Hepatitis C virus nonstructural 5A (HCV NSSA) on IFNα induced signal transducer and activator of transcription-1 (STAT1) phosphorylation and nuclear translocation.METHODS: Expression of STAT1 Tyr701 phosphorylation at different time points was confirmed by Western blot, and the time point when p-STAT1 expressed most, was taken as the IFN induction time for further studies. Immunocytochemistry was used to confirm the successful transient transfection of NS5A expression plasmid. Immunofluorescene was performed to observe if there was any difference in IFNα-induced STAT1 phosphorylation and nuclear translocation between HCV NSSA-expressed and non-HCV NSSA-expressed cells. Western blot was used to compare the phosphorylated STAT1 protein of the cells.RESULTS: Expression of HCV NS5A was found in the cytoplasm of pCNS5A-transfected Huh7 cells, but not in the PRC/ CMV transfected or non-transfected cells, STAT1 Tyr701 phosphorylation was found strongest in 30 min of IFN induction, STAT1 phosphorylation and nuclear import were much less in the presence of HCV NS5A protein in contrast to pRC/CMV-transfected and non-transfected cells under fluorescent microscopy, which was further confirmed by Western blot.CONCLUSION: HCV NSSA expression plasmid is successfully transfected into Huh7 cells and HCV NS5A protein is expressed in the cytoplasm of the cells. IFN-α is able to induce STAT1 phosphrylation and nuclear translocation, and this effect is inhibited by HCV NS5A protein, which might be another possible resistance mechanism to interferon alpha therapy. 展开更多
关键词 Hepatitis C virus nonstructural protein 5A IFN-Α Signal transducer and activator of transcription (STAT1) PHOSPHORYLATION Nuclear translocation
下载PDF
A Novel Traveling Wave Ultrasonic Motor Using a Bar Shaped Transducer 被引量:4
15
作者 金家楣 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2008年第6期961-963,共3页
A novel traveling wave ultrasonic motor was proposed. The structure of the motor is rather simple and different from the conventional traveling wave ultrasonic motors. Its production processes are very convenient. It ... A novel traveling wave ultrasonic motor was proposed. The structure of the motor is rather simple and different from the conventional traveling wave ultrasonic motors. Its production processes are very convenient. It is composed of a stator constituted with a ring and a bar shaped transducer and two cone shaped rotors. The rotors were pressed on inner surface of the ring by means of a pre-pressure system. The bar shaped transducer has a sand- wich-like configuration,where two sets of piezoelectric element are bolted. One set excites a longitudinal vibration of the bar, and the other set excites a flexural vibration of the bar. The ring's traveling wave excited with the longitudinal vibration and the bending vibration of the bar transducer was simulated with FEM (finite element method). The prototype of the motor was made and investigated experimentally for its performance. Its maximum torque and rotating speed are 0.25 N · m and 50 r/min, respectively. 展开更多
关键词 ultrasonic motor traveling wave bar transducer
下载PDF
Butein effects in colitis and interleukin-6/signal transducer and activator of transcription 3 expression 被引量:3
16
作者 Sehe Dong Lee Jung Wan Choe +7 位作者 Beom Jae Lee Myoung Hee Kang Moon Kyung Joo Ji Hoon Kim Jong Eun Yeon Jong-Jae Park Jae Seon Kim Young-Tae Bak 《World Journal of Gastroenterology》 SCIE CAS 2015年第2期465-474,共10页
AIM: To evaluate the effects of butein on inflammatory cytokines, matrix metalloproteinase-9(MMP-9), andcolitis in interleukin(IL)-10-/- mice.METHODS: To synchronize colitis, 8- to 10-wk-old IL-10-/- mice were fed pel... AIM: To evaluate the effects of butein on inflammatory cytokines, matrix metalloproteinase-9(MMP-9), andcolitis in interleukin(IL)-10-/- mice.METHODS: To synchronize colitis, 8- to 10-wk-old IL-10-/- mice were fed pellet-chow containing piroxicam for 2 wk. Subsequently, phosphate-buffered saline or butein(1 mg/kg per day, ip) was injected for 4 wk. Histologic scores, inflammatory cytokines, MMP-9 and phosphorylated signal transducer and activator of transcription 3(p STAT3) expressions were analyzed in IL-10-/- mice and in Colo 205 cells.RESULTS: Butein reduced the colonic inflammatory score by > 50%. Expression levels of IL-6, IL-1β, interferon(IFN)-γ and MMP-9 were decreased in the colons of mice exposed to butein, whereas other inflammatory cytokines(IL-17 A, IL-21 and IL-22) were unchanged. Immunohistochemical staining for p STAT3 and MMP-9 was significantly decreased in the buteintreated groups compared with the controls. Butein inhibited IL-6-induced activation of STAT3 in Colo 205 cells.CONCLUSION: Butein ameliorated colitis in IL-10-/-mice by regulating IL-6/STAT3 and MMP-9 activation. 展开更多
关键词 BUTEIN Interleukin-6/signal transducer and activat
下载PDF
Lamb wave signal selective enhancement by an improved design of meander-coil electromagnetic acoustic transducer 被引量:3
17
作者 Wen-Xiu Sun Guo-Qiang Liu +1 位作者 Hui Xla Zheng-Wu Xia 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第8期308-314,共7页
In this paper, we investigate a method of selectively enhancing the single mode signal of a Lamb wave by using a meander-coil electromagnetic acoustic transducer (EMAT) with a new magnetic configuration. We use the ... In this paper, we investigate a method of selectively enhancing the single mode signal of a Lamb wave by using a meander-coil electromagnetic acoustic transducer (EMAT) with a new magnetic configuration. We use the Lamb antisym- metric (A0) mode and symmetric (SO) mode as an example for analysis. The analytical expression of the magnitude of the spatial Fourier transform of the Lorentz force generated by different meander coils is used to determine the optimal driving frequency for single mode generation. The numerical calculation is used to characterize the new magnetic configuration and the conventional EMAT magnet. Experimental examinations of each meander coil in combination with the conventional and new magnetic configuration show that the Lamb wave signal can be selectively enhanced by choosing the appropriate driving frequency and coil parameters through using the improved meander-coil EMAT. 展开更多
关键词 Lamb wave selective enhancement meander-coil electromagnetic acoustic transducer (EMAT)
下载PDF
Structure Optimization of Wheel Force Transducer Based on Natural Frequency and Comprehensive Sensitivity 被引量:2
18
作者 Xiao-Long Zhang Ti Wu +1 位作者 Yan Shao Jian Song 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第4期973-981,共9页
The current research of wheel force transducer (WFT) mainly focuses on test signal processing and decoupling methods based on signal itself, while the WFT structure optimization research related to decreasing the ma... The current research of wheel force transducer (WFT) mainly focuses on test signal processing and decoupling methods based on signal itself, while the WFT structure optimization research related to decreasing the mass and increase the natural frequency and comprehen- sive sensitivity is not enough. In order to improve the WFT test accuracy, a structure optimization method based on natural frequency and comprehensive sensitivity indicators is put forward. The WPT with 8-beam elastic body is used for the finite element modeling (FEM), in which the fol- lowing variations are taken into consideration: the con- nection type of elastic body with modified rim, the number of connection holes, and the respects of strain beam including the shape, the cross sectional area and the length, etc.. The test results shows that the natural frequency of the connecting block type is increased by 65.5% compared with the connecting seat type of elastic body & modified rim, and the main channel sensitivity is improved as well. The results show that the connecting block type will achieve the best comprehensive performance when the number of connecting holes between the elastic body and the modified rim is 20. And the thinner and longer strain beam with smaller cross section area is preferable within the scope of elastic body mechanical strength. This research proposes a novel structure optimization method for WFT which contributes to improve the measurement performance of WFT. 展开更多
关键词 Wheel force transducer Structureoptimization Basic vibration frequency Comprehensivesensitivity Finite element method
下载PDF
Design of interdigitated transducers for acoustofluidic applications 被引量:2
19
作者 Shuren Song Qi Wang +1 位作者 Jia Zhou Antoine Riaud 《Nanotechnology and Precision Engineering》 CAS CSCD 2022年第3期36-54,共19页
Interdigitated transducers(IDTs)were originally designed as delay lines for radars.Half a century later,they have found new life as actuators for microfluidic systems.By generating strong acoustic fields,they trigger ... Interdigitated transducers(IDTs)were originally designed as delay lines for radars.Half a century later,they have found new life as actuators for microfluidic systems.By generating strong acoustic fields,they trigger nonlinear effects that enable pumping and mixing of fluids,and moving particles without contact.However,the transition from signal processing to actuators comes with a range of challenges concerning power density and spatial resolution that have spurred exciting developments in solid-state acoustics and especially in IDT design.Assuming some familiarity with acoustofluidics,this paper aims to provide a tutorial for IDT design and characterization for the purpose of acoustofluidic actuation.It is targeted at a diverse audience of researchers in various fields,including fluid mechanics,acoustics,and microelectronics. 展开更多
关键词 Acoustic field Surface acoustic wave transducer Finite-element analysis SIMULATION Acoustical properties LAB-ON-A-CHIP Acoustic wave attenuation
下载PDF
Working principle and design of a double cylinders type traveling wave ultrasonic motor using composite transducer 被引量:2
20
作者 陈维山 刘英想 +1 位作者 刘军考 石胜君 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第2期28-32,共5页
A double cylinders type traveling wave ultrasonic motor using composite transducer was proposed.The proposed stator contained two cylinders and one composite transducer,and the transducer located on the outer surfaces... A double cylinders type traveling wave ultrasonic motor using composite transducer was proposed.The proposed stator contained two cylinders and one composite transducer,and the transducer located on the outer surfaces of cylinders.The composite transducer included two exponential horns located on leading ends,and the horns insected with the cylinders at tip ends.Two degenerated flexural vibration modes spatially and temporally orthogonal to each other were excited in each cylinder by the composite transducer.In this new design,a single transducer could excite two flexural traveling waves in the cylinders.Thus,elliptical motions were achieved at the particles on the teeth.The working principle of the proposed motor was analyzed.The cylinder and transducer were designed with FEM.The resonant frequencies of two vibration modals of the stator were tuned to be the same,and the motion trajectories of nodes on the teeth were analyzed.Transient analysis results show that the motion trajectories of teeth are ellipses.The results of this paper can guide the development of this new type of ultrasonic motor. 展开更多
关键词 ultrasonic motor traveling wave double cylinders composite transducer FEM
下载PDF
上一页 1 2 22 下一页 到第
使用帮助 返回顶部