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124篇 您的检索式:作者名="Ken CHEN"
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1Value of circulating cell-free DNA in diagnosis of hepatocelluar carcinoma显示文摘AIM:To investigate the value of combined detection of circulating cell-free DNA(cfDNA),a-fetal protein(AFP) and a L-fucosidase(AFU) for diagnosis of hepatocellular carcinoma(HCC).METHODS:Serum samples from 39 HCC patients and 45 normal controls were collected.Branched DNA(bDNA) was used to detect the level of cfDNA,and a receiver operating characteristic curve was employed to evaluate the diagnostic sensitivity,specificity,accuracy,positive predictive value,negative predictive value,positive likelihood ratio,negative likelihood ratio and Youden index,and to assess the diagnostic efficiency and their correlations with the clinicopathological features.AFP and AFU were detected by chemiluminescence and colorimetry,respectively.The significance of combined detection of the three biomarkers was discussed.RESULTS:cfDNA level was increased in 22 of the 39 HCC samples and in 2 of the 45 normal controls.cfDNA level in HCC samples was significantly higher than that in normal controls(P < 0.05).There were significant differences in sex and extra-and intrahepatic metastasis(P < 0.05).There was no significant correlation between cfDNA,AFP and AFU in the detection of HCC.The sensitivity of combined detection of cfDNA with one marker(AFP or AFU) and cfDNA with two markers(AFP and AFU) was 71.8%,87.2% and 89.7% vs 56.4%,53.8% and 66.7% for cfDNA,AFP and AFU used alone,respectively,the difference being statistically significant(P < 0.05).CONCLUSION:Quantitative analysis of cfDNA is sensitive and feasible,and the combined detection of cfDNA with AFP or AFU or both could improve the diagnostic sensitivity for HCC.Ken Chen Hong Zhang Li-Na Zhang Shao-Qing Ju Jing Qi Dong-Feng Huang Feng Li Qun Wei Jing Zhang 2013World Journal of Gastroenterology2013,19,20:16
2Cell-permeable Tat-NBD peptide attenuates rat pancreatitis and acinus cell inflammation response显示文摘AIM: To investigate the effects of Tat-NEMO-binding domain (NBD) peptide on taurocholate-induced pancreatitis and lipopolysaccharide (LPS)-stimulated AR42J acinus cells inflammatory response in rats. METHODS: Sodium taurocholate (5%) was used to induce the pancreatitis model. Forty-eight rats from the taurocholate group received an intravenous bolus of 13 mg/kg Tat-NBD (wild-type, WT) peptide, TatNBD (mutant-type, MT) peptide, NBD peptide or Tat peptide. The pancreatic histopathology was analyzed by hematoxylin staining. LPS was added to the culture medium to stimulate the AR42J cells. For pretreatment, cells were incubated with different peptides for 2 h before LPS stimulation. Expression of IL-1β and TNF-α mRNA was analyzed using a semi-quantitative reverse-transcript polymerase chain reaction (RT-PCR) method. IL-1β and TNF-α protein in culture medium were detected by enzyme linked immunosorbent assay (ELISA). NF-κB DNA-binding in pancreas was examined by electrophoretic mobility shift assays. P65 expression of AR42J was determined by Strept Actividin-Biotin Complex (SABC) method. RESULTS: Pretreatment with Tat-NBD (WT) peptide at a concentration of 13 mg/kg body wt showed beneficial effect in pancreaitis model. LPS (10 mg/L) resulted in an increase of IL-1β mRNA, IL-1β protein, TNF-α mRNA and TNF-α protein, whereas signifi cantly inhibitory effects were observed when cells were incubated with Tat-NBD (WT). Consisting with p65 expression decrease analyzed by SABC method, NF-κB DNA-binding activity significantly decreased in Tat-NBD (WT) pretreatment group, especially at the largest dose. No significant changes were found in the control peptide group. CONCLUSION: Our result supports that active NF-κB participates in the pathogenesis of STC-induced acute pancreatitis in rats. Tat-NBD (WT) peptide has anti-inflammatory effects in this model and inhibits the inflammation of acinus simulated by LPS.You-Ming Long Ken Chen Xue-Jin Liu Wen-Rui Xie Hui Wang 2009World Journal of Gastroenterology2009,15,5:11
3Spatial Properties of Mismatch Negativity in Patients with Disorders of Consciousness显示文摘In recent decades, event-related potentials have been used for the clinical electrophysiological assessment of patients with disorders of consciousness(DOCs). In this paper, an oddball paradigm with two types of frequencydeviant stimulus(standard stimuli were pure tones of 1000 Hz; small deviant stimuli were pure tones of 1050 Hz; large deviant stimuli were pure tones of 1200 Hz) was applied to elicit mismatch negativity(MMN) in 30 patients with DOCs diagnosed using the JFK Coma Recovery ScaleRevised(CRS-R). The results showed that the peak amplitudes of MMN elicited by both large and small deviant stimuli were significantly different from baseline.In terms of the spatial properties of MMN, a significant interaction effect between conditions(small and large deviant stimuli) and electrode nodes was centered at the frontocentral area. Furthermore, correlation coefficients were calculated between MMN amplitudes and CRS-R scores for each electrode among all participants to generate topographic maps. Meanwhile, a significant negative correlation between the MMN amplitudes elicited by large deviant stimuli and the CRS-R scores was also found at the frontocentral area. In consequence, our results combine the above spatial properties of MMN in patients with DOCs,and provide a more precise location(frontocentral area) at which to evaluate the correlation between clinical electrophysiological assessment and the level of consciousness.Xiaoyu Wang Rao Fu Xiaoyu Xia Xueling Chen Han Wu Nicole LANDi Ken Pugh Jianghong He Fengyu Cong 2018Neuroscience Bulletin2018,34,4:9
4Modeling on the shock wave in spheres hypervelocity impact on flat plates显示文摘In hypervelocity impacts of projectiles into thin flat targets,shock initiation and interaction dominate the responses of projectiles and targets,and especially dominate the features of the debris cloud.To estimate the geometric features of the wave front during the first complete propagation in the sphericalprojectile,the Geometric Propagation Model(GPM)is built in this paper to describe the geometry of the shock wave front,which proposes an ellipse contour as a function of time and equivalent speed.The GPM identifies the geometric features of the wave front as a function of time and impact velocity successfully.Combined with the GPM and SPH simulation,the shock pressure distribution and attenuation in the spherical-projectile have been obtained.Meanwhile,the attenuation of shock pressure and speed are presented as a function of impact velocity,respectively,and a method for obtaining the equivalent speed of the shock wave is proposed by the GPM.The GPM may be applicable to hypervelocity events involving any monolithic materials as long as the equivalent speed could be supplied from numerical simulation.The GPM proposed in this paper and the corresponding shock wave analysis provide a new insight into the processes of the quantitative analysis of the initiation of the debris cloud.Ken Wen Xiao-Wei Chen De-Ning Di 2019Defence Technology(防务技术)2019,15,4:8
5IMAGE PROFILE AREA CALCULATION BASED ON CIRCULAR SAMPLE MEASUREMENT CALIBRATION显示文摘A practical approach of measurement calibration is presented for obtaining the true area of the photographed objects projected in the 2-D image scene. The calibration is performed using three circular samples with given diameters. The process is first to obtain the ratio mm/pixel in two orthogonal directions, and then use the obtained ratios with the total number of pixels scanned within projected area of the object of interest to compute the desired area. Compared the optically measured areas with their corresponding true areas, the results show that the proposed method is quite encouraging and the relevant application also proves the approach adequately accurate.Chen Ken Larry E.Banta 2005Journal of Electronics(China)2005,22,5:7
62-D IMAGE-BASED VOLUMETRIC MODELING FOR PARTICLE OF RANDOM SHAPE显示文摘In this paper, an approach to predicting randomly-shaped particle volume based on its two-Dimensional (2-D) digital image is explored. Conversion of gray-scale image of the particles to its binary coun-terpart is first performed using backlighting technique. The silhouette of particle is thus obtained, and conse-quently, informative features such as particle area, centroid and shape-related descriptors are collected. Several dimensionless parameters are defined, and used as regressor variables in a multiple linear regression model to predict particle volume. Regressor coefficients are found by fitting to a randomly selected sample of 501 parti-cles ranging in size from 4.75mm to 25mm. The model testing experiment is conducted against a different ag-gregate sample of the similar statistical properties, the errors of the model-predicted volume of the batch is within ±2%.Chen Ken Larry E. Banta Jiang Gangyi 2006Journal of Electronics(China)2006,23,6:6
7Orientation to learning context modulates retrieval processing for unrecognized words显示文摘Explicit memory errors may occur when individuals fail to retrieve information about items previously studied (item memory) or about the learning context (source memory). We examined electrophysiological measures during recognition failure in order to determine the influence of retrieval orientation for item versus source information. Recognition failure was associated with brain potentials distinct from those associated with success. Furthermore, source-memory failures were associated with earlier-onset brain potentials with a more anterior distribution compared to item-memory failures. Neurocognitive processing was thus modulated by retrieval orientation so as to differentially influence neural correlates of successful versus unsuccessful retrieval.GUO ChunYan CHEN WenJun TIAN Tian Ken A PALLER Joel L VOSS 2010Chinese Science Bulletin2010,55,26:6
8Characteristics structure analysis on debris cloud in the hypervelocity impact of disk projectile on thin plate显示文摘In this paper,the gauge points setting is introduced in the SPH simulation to analyze the debris cloud structure generated by the hypervelocity impact of disk projectile on thin plate.Compared with the experiments,more detailed information of the debris cloud structure can be classified from the numerical simulation.However,due to the solitary dispersion and overlap display of the particles in the SPH simulation,accurate comparison between numerical and experimental results is difficult to be performed.To track the velocity and spatial distribution of the particles in the debris cloud induced from disk and plate,gauge points are locally set in the single-layer profile in the SPH model.By analyzing the gauge points’spatial coordinate and velocity,the location and velocity of characteristic points in the debris cloud are determined.The boundary of debris cloud is achieved,as well as the fragments distribution outside the main structure of debris cloud.Chun-bo Zhang De-ning Di Xiao-wei Chen Ken Wen 2020Defence Technology(防务技术)2020,16,2:6
9Impact of adjustment measures on reducing outpatient waiting time in a community hospital: application of a computer simulation显示文摘是的背景耐心的满足的一个重要决定因素,等待的时间,在护理服务的地里获得了增加的注意。试图说明在一所社区医院里等待时间的分发特征并且探索潜力的影响的现在的学习测量减少基于一条计算机模拟途径等待时间的门诊病人。方法在 2006 在一个一个月期间学习经期,代表性的研究在位于上海的一所社区医院里被进行,中国。等待时间的门诊病人的基线数据根据登记时间和支付时间的记录被计算。一种模拟技术被采用在减少等待的时间上调查观点改革方法的影响。从 10 092 个病人和 26 816 医药咨询的一个总数的结果数据在学习被收集, 19 947 医药咨询被包括。这所医院里的门诊病人的全部的访问时间的一般水准是在早上,在下午的 19.1 分钟,和 34.3 分钟的 43.6 分钟因为整个天学习了时期。模拟结果建议门诊病人的那等待的时间能极大地通过约会系统和根据在工作日的不同时间等待的病人的数字安排的灵活面向要求的医生的介绍被减少。一个约会系统的结论采纳和医生安排的灵活管理可以是完成减少的等待的时间的有效方法。CHEN Bai-lian LI En-dong Kazunobu Yamawuchi Ken Kato Shinji Naganawa MIAO Wei-jun 2010Chinese Medical Journal2010,,5:5
10Gait Definition and Successive Gait-transition Method Based on Energy Consumption for a Quadruped显示文摘In nature,to realize the smooth motion for different speeds,the continuous gait transition is usually required for the quadrupeds.Thus,the gait simulation of quadrupeds is a requisite step to obtain the stable and energy-efficient gait for the walking machines.In this paper,the definitions of the two gait parameters,phasic difference and duty factor are presented,which can determine the gait of the quadrupeds.Then,several typical gaits of the quadrupeds are analyzed such that the seven standard gaits and corresponding parameters are summarized.Additionally,the variance law of the two parameters,which determine the relationship of gait transition,is analyzed.Furthermore,the quadruped gait derivative spectrum (QGDS) is proposed and the gait definition of the quadrupeds is presented.To minimize the power consumption,the choice criterion of gait,the optimal gait in terms of the motion speed,duty factory,and power consumption for the walking machines,is developed.Last,the continuous variance of the gait is implemented by the simulation of the gait transition from walk to trot,which evaluate the choice criterion and transition of gait.ZHAO Danpu XU Jing WU Dan CHEN Ken LI Chengrong 2012Chinese Journal of Mechanical Engineering2012,25,1:5
11SADDLE-POINT BASED SEPARATION OF TOUCHED OBJECTS IN 2-D IMAGE显示文摘In many image analysis and processing problems, discriminating the size and shape of each individual object in an aggregate pile projected in an image is an important practice. It is relatively easy to distinguish these features among the objects already separated from each other. The problems will be undoubtedly more complex and of greater challenge if the objects are touched or/and overlapped. This letter presents an algorithm that can be used to separate the touches and overlaps existing in the objects within a 2-D image. The approach is first to convert the gray-scale image to its corresponding binary one and then to the 3-D topographic one using the erosion operations. A template (or mask) is engineered to search the topographic surface for the saddle point, from which the segmenting orientation is determined followed by the desired separating operation. The algorithm is tested on a real image and the running result is adequately satisfying and encouraging.Chen Ken Larry E. Banta Jiang Gangyi 2006Journal of Electronics(China)2006,23,3:5
122D IMAGE BASED SIEVING FOR PARTICLE AGGREGATE GRADATION显示文摘Acquiring the size gradation for particle aggregates is a common practice in the granule related industry,and mechanical sieving or screening has been the normal method. Among many drawbacks of this conventional means,the major ones are time-consuming,labor-intensive,and being unable to provide real-time feedback for process control. In this letter,an optical sieving approach is introduced. The two-dimensional images are used to develop methods for inferring particle volume and sieving behavior for gradation purposes. And a combination of deterministic and probabilistic methods is described to predict the sieving behaviors of the particles and to construct the gradation curves for the aggregate sample. Comparison of the optical sieving with standard mechanical sieving shows good correlation.Chen Ken John Zaniewski Zhao Pan Yang Ren'er 2008Journal of Electronics(China)2008,25,2:5
13Magnetic Array Assisted Triboelectric Nanogenerator Sensor for Real‑Time Gesture Interaction显示文摘In human-machine interaction,robotic hands are useful in many scenarios.To operate robotic hands via gestures instead of handles will greatly improve the convenience and intuition of human-machine interaction.Here,we present a magnetic array assisted sliding triboelectric sensor for achieving a real-time gesture interaction between a human hand and robotic hand.With a finger’s traction movement of flexion or extension,the sensor can induce positive/negative pulse signals.Through counting the pulses in unit time,the degree,speed,and direction of finger motion can be judged in realtime.The magnetic array plays an important role in generating the quantifiable pulses.The designed two parts of magnetic array can transform sliding motion into contact-separation and constrain the sliding pathway,respectively,thus improve the durability,low speed signal amplitude,and stability of the system.This direct quantization approach and optimization of wearable gesture sensor provide a new strategy for achieving a natural,intuitive,and real-time human-robotic interaction.Ken Qin Chen Chen Xianjie Pu Qian Tang Wencong He Yike Liu Qixuan Zeng Guanlin Liu Hengyu Guo Chenguo Hu 2021Nano-Micro Letters2021,13,3:5
14Early Helicobacter pylori Eradication Decreases Risk of Gastric Cancer in Patients With Peptic Ulcer Disease显示文摘Chun–Ying Wu Ken N. Kuo Ming–Shiang Wu Yi–Ju Chen Chang–Bi Wang Jaw–Town Lin 2009Gastroenterology2009,,5:4
15HESSIAN MATRIX BASED SADDLE POINT DETECTION FOR GRANULES SEGMENTATION IN 2D IMAGE显示文摘Segmenting the touching objects in an image has been remaining as a hot subject due to the problematic complexities, and a vast number of algorithms designed to tackle this issue have come into being since a decade ago. In this paper, a new granule segmentation algorithm is developed using saddle point as the cutting point. The image is binarized and then sequentially eroded to form a gray-scale topographic counterpart, followed by using Hessian matrix computation to search for the saddle point. The segmentation is performed by cutting through the saddle point and along the maximal gradient path on the topographic surface. The results of the algorithm test on the given real images indicate certain superiorities in both the segmenting robustness and execution time to the referenced methods.Chen Ken Wang Yicong Yang Rener 2008Journal of Electronics(China)2008,25,6:4
16OPTIMIZED MEANSHIFT TARGET REFERENCE MODEL BASED ON IMPROVED PIXEL WEIGHTING IN VISUAL TRACKING显示文摘The generic Meanshift is susceptible to interference of background pixels with the target pixels in the kernel of the reference model, which compromises the tracking performance. In this paper, we enhance the target color feature by attenuating the background color within the kernel through enlarging the pixel weightings which map to the pixels on the target. This way, the background pixel interference is largely suppressed in the color histogram in the course of constructing the target reference model. In addition, the proposed method also reduces the number of Meanshift iterations, which speeds up the algorithmic convergence. The two tests validate the proposed approach with improved tracking robustness on real-world video sequences.Chen Ken Song Kangkang Kyoungho Choi Guo Yunyan 2013Journal of Electronics(China)2013,30,3:4
17The Origin and Evolution of Mutations in Acute Myeloid Leukemia显示文摘John S. Welch Timothy J. Ley Daniel C. Link Christopher A. Miller David E. Larson Daniel C. Koboldt Lukas D. Wartman Tamara L. Lamprecht Fulu Liu Jun Xia Cyriac Kandoth Robert S. Fulton Michael D. McLellan David J. Dooling John W. Wallis Ken Chen Christop 2012Cell2012,,2:3
18A LINEAR APPROACH TO METRIC CIRCUMFERENCE COMPUTATION FOR DIGITIZED CONVEX SHAPES显示文摘Metric measurement of digitized shapes is commonly applied in optical measuring systems.In this letter,three shape-related factors defined by the authors are used in the construction of amultiple linear regression model which is utilized to compute the circumference of the convex shapes inmillimeter unit.The model is first built upon the relationship hypothesis and then its adequacy ismathematically validated.The results of applying the developed model to the given number of convexshapes in a finite circumferential length range suggest that,in terms of percent error,the model pre-cision is to satisfaction by being within±4%.The test also shows the model’s robustness against theshape’s orientation anisotropy.Chen Ken Zhao Pan Yang Rener 2008Journal of Electronics(China)2008,25,4:3
19Biodegradable nanocarriers for small interfering ribonucleic acid (siRNA) co-delivery strategy increase the chemosensitivity of pancreatic cancer cells to gemcitabine显示文摘Ribonucleic acid (RNA) interference (RNAi) therapies are promising cancertreatment modalities that can specifically target abnormal proto-oncogenes, thusimproving the therapeutic effect. For the treatment of pancreatic cancer, targetingone mutant proto-oncogene by RNAi usually does not yield the desired therapeuticefficiency. Both K-ras gene mutations and Notch1 overexpression are commonsymptoms in pancreatic cancer patients, and play a crucial role in pancreaticcancer cell drug resistance. In this study, biodegradable charged polyester-basedvectors (BCPVs) were synthesized for the co-delivery of K-ras and Notch1 smallinterfering ribonucleic acid (siRNA) into MiaPaCa-2 cells (pancreatic cancercell line) to overcome drug resistance to gemcitabine (GEM), a first-line chem-otherapeutic drug used in the clinic. BCPVs could effectively absorb negative siRNAto form a capsule-like structure, prevent siRNA from nuclease digestion in theserum, and promote effective siRNA cell internalization and endosomal escape.Through K-ras and Notch1 gene silencing in MiaPaCa-2 cells, BCPV-siRNAKsiRNAN^tcm nanocomplexes effectively reversed the epithelia-mesenchymaltransition (EMT) in MiaPaCa-2 cells, thereby greatly enhancing the sensitivity ofMiaPaCa-2 cells to GEM. MiaPaCa-2 cell proliferation, migration, and invasionwere effectively inhibited, and cell apoptosis was also significantly enhanced bythe synergistic antitumor effect of BCPV-siRNAK siRNAN^t~l nanocomplexesand GEM. These results suggest that this combination RNAi therapy can be usedto improve cancer cell sensitivity to chemotherapeutic drugs. Specifically, thisnewly develooed strate^v has a great potential for treating pancreatic cancer.Chengbin Yang Kok Ken Chan Wen-Jen Lin Alana Mauluidy Soehartono Guimiao Lin Huiting Toh Ho Sup Yoon Chih-Kuang Chen Ken-Tye Yong 2017Nano Research2017,10,9:3
20Analysis of the stress wave and rarefaction wave produced by hypervelocity impact of sphere onto thin plate显示文摘Shock wave is emitted into the plate and sphere when a sphere hypervelocity impacts onto a thin plate.The fragmentation and phase change of the material caused by the propagation and unloading of shock wave could result in the formation of debris cloud eventually.Propagation models are deduced based on one-dimensional shock wave theory and the geometry of sphere,which uses elliptic equations(corresponding to ellipsoid equations in physical space)to describe the propagation of shock wave and the rarefaction wave.The“Effective thickness”is defined as the critical plate thickness that ensures the rarefaction wave overtake the shock wave at the back of the sphere.The“Effective thickness”is directly related to the form of the debris cloud.The relation of the“Effective thickness”and the“Optimum thickness”is also discussed.The impacts of Al spheres onto Al plates are simulated within SPH to verify the propagation models and associated theories.The results show that the wave fronts predicted by the propagation models are closer to the simulation result at higher impact velocity.The curvatures of the wave fronts decrease with the increase of impact velocities.The predicted“Effective thickness”is consistent with the simulation results.The analysis about the shock wave propagation and unloading in this paper can provide a new sight and inspiration for the quantitative study of hypervelocity impact and space debris protection.Ken Wen Xiao-wei Chen 2020Defence Technology(防务技术)2020,16,5:3
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