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Search Results: 1 - 10 of 175887 matches for " Li-Wei Chang "
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Differentially Expressed MicroRNAs in Chondrocytes from Distinct Regions of Developing Human Cartilage
Audrey McAlinden, Nobish Varghese, Louisa Wirthlin, Li-Wei Chang
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0075012
Abstract: There is compelling in vivo evidence from reports on human genetic mutations and transgenic mice that some microRNAs (miRNAs) play an important functional role in regulating skeletal development and growth. A number of published in vitro studies also point toward a role for miRNAs in controlling chondrocyte gene expression and differentiation. However, information on miRNAs that may regulate a specific phase of chondrocyte differentiation (i.e. production of progenitor, differentiated or hypertrophic chondrocytes) is lacking. To attempt to bridge this knowledge gap, we have investigated miRNA expression patterns in human embryonic cartilage tissue. Specifically, a developmental time point was selected, prior to endochondral ossification in the embryonic limb, to permit analysis of three distinct populations of chondrocytes. The location of chondroprogenitor cells, differentiated chondrocytes and hypertrophic chondrocytes in gestational day 54–56 human embryonic limb tissue sections was confirmed both histologically and by specific collagen expression patterns. Laser capture microdissection was utilized to separate the three chondrocyte populations and a miRNA profiling study was carried out using TaqMan? OpenArray? Human MicroRNA Panels (Applied Biosystems?). Here we report on abundantly expressed miRNAs in human embryonic cartilage tissue and, more importantly, we have identified miRNAs that are significantly differentially expressed between precursor, differentiated and hypertrophic chondrocytes by 2-fold or more. Some of the miRNAs identified in this study have been described in other aspects of cartilage or bone biology, while others have not yet been reported in chondrocytes. Finally, a bioinformatics approach was applied to begin to decipher developmental cellular pathways that may be regulated by groups of differentially expressed miRNAs during distinct stages of chondrogenesis. Data obtained from this work will serve as an important resource of information for the field of cartilage biology and will enhance our understanding of miRNA-driven mechanisms regulating cartilage and endochondral bone development, regeneration and repair.
Zigzag GaN/Ga2O3 heterogeneous nanowires: Synthesis, optical and gas sensing properties
Li-Wei Chang,Jan-Hau Chang,Jien-Wei Yeh,Heh-Nan Lin
AIP Advances , 2011, DOI: 10.1063/1.3624331
Abstract: Zigzag GaN/Ga2O3 heterogeneous nanowires (NWs) were fabricated, and the optical properties and NO gas sensing ability of the NWs were investigated. We find that NWs are most effective at 850 °C at a switching process once every 10 min (on/off = 10 min per each) with a mixture flow of NH3 and Ar. The red shift of the optical bandgap (0.66 eV) is observed from the UV-vis spectrum as the GaN phase forms. The gas sensing characteristics of the developed sensor are significantly replaced to those of other types of NO sensors reported in literature.
The Nucleolus of Caenorhabditis elegans
Li-Wei Lee,Chi-Chang Lee,Chi-Ruei Huang,Szecheng J. Lo
Journal of Biomedicine and Biotechnology , 2012, DOI: 10.1155/2012/601274
Abstract: Nucleolar size and appearance correlate with ribosome biogenesis and cellular activity. The mechanisms underlying changes in nucleolar appearance and regulation of nucleolar size that occur during differentiation and cell cycle progression are not well understood. Caenorhabditis elegans provides a good model for studying these processes because of its small size and transparent body, well-characterized cell types and lineages, and because its cells display various sizes of nucleoli. This paper details the advantages of using C. elegans to investigate features of the nucleolus during the organism's development by following dynamic changes in fibrillarin (FIB-1) in the cells of early embryos and aged worms. This paper also illustrates the involvement of the ncl-1 gene and other possible candidate genes in nucleolar-size control. Lastly, we summarize the ribosomal proteins involved in life span and innate immunity, and those homologous genes that correspond to human disorders of ribosomopathy.
Hyaluronan modulates accumulation of hypoxia-inducible factor-1 alpha, inducible nitric oxide synthase, and matrix metalloproteinase-3 in the synovium of rat adjuvant-induced arthritis model
Li-Wei Chou, John Wang, Pei-Lin Chang, Yueh-Ling Hsieh
Arthritis Research & Therapy , 2011, DOI: 10.1186/ar3365
Abstract: Monoarthritis was induced in adult male Sprague-Dawley (250-300 g) via intraarticular injection of complete Freund's adjuvant (CFA) into the tibiotarsal joint. The CFA-induction arthritis animals were divided into three groups: treatment (intraarticular injection of HA), placebo (intraarticular injection of saline) and controls (no treatments). Functional evaluations of edema and pain behavior, histology, and HIF-1alpha, iNOS, and MMP3 immunohistochemistry were performed before, after the first injection, three injections, and on the follow-up injection of the treatments.Intra-articular injection of HA also significantly suppressed the mechanical allodynia (p < 0.001) and overexpressions of HIF-1alpha (p < 0.001), iNOS (p = 0.004) and MMP3 (p < 0.001) immunoreactivity in synovium.This study demonstrated that early intervention of HA is an effective protection against accumulation of inflammation-induced HIF-1alpha, iNOS, and MMP3 to limit erosive damage in CFA-induced model of arthritis.A hypoxic microenvironment is a hallmark of the inflamed synovium and its importance in the pathogenesis of rheumatoid arthritis (RA) has been documented [1-4]. In human and animal arthritis models, the importance of hypoxia for the development and persistence of RA has been demonstrated [1,5]. Previous studies have demonstrated the hypoxic nature of the synovium of patients with RA and the constitutive expression of hypoxia-inducible factor-1-alpha (HIF-1α), a key regulator of hypoxia transcriptional response. In RA joints hypoxia has been shown to express increased amounts of HIF-1α and HIF-1 target genes in synovial lining cells and articular chondrocytes under hypoxic conditions, which aggravate joint inflammation [6,7]. Previous studies also demonstrated that hypoxia takes place in the synovium at the pre-arthritic stage or early stage of the disease and has a close spatial relationship and positive severity correlation with synovitis [8]. Therefore, HIF-1α is identified as a ke
Prioritizing Potentially Druggable Mutations with dGene: An Annotation Tool for Cancer Genome Sequencing Data
Runjun D. Kumar, Li-Wei Chang, Matthew J. Ellis, Ron Bose
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0067980
Abstract: A major goal of cancer genome sequencing is to identify mutations or other somatic alterations that can be targeted by selective and specific drugs. dGene is an annotation tool designed to rapidly identify genes belonging to one of ten druggable classes that are frequently targeted in cancer drug development. These classes were comprehensively populated by combining and manually curating data from multiple specialized and general databases. dGene was used by The Cancer Genome Atlas squamous cell lung cancer project, and here we further demonstrate its utility using recently released breast cancer genome sequencing data. dGene is designed to be usable by any cancer researcher without the need for support from a bioinformatics specialist. A full description of dGene and options for its implementation are provided here.
Interval Wavelet Numerical Method on Fokker-Planck Equations for Nonlinear Random System
Li-wei Liu
Advances in Mathematical Physics , 2013, DOI: 10.1155/2013/651357
Abstract: The Fokker-Planck-Kolmogorov (FPK) equation governs the probability density function (p.d.f.) of the dynamic response of a particular class of linear or nonlinear system to random excitation. An interval wavelet numerical method (IWNM) for nonlinear random systems is proposed using interval Shannon-Gabor wavelet interpolation operator. An FPK equation for nonlinear oscillators and a time fractional Fokker-Planck equation are taken as examples to illustrate its effectiveness and efficiency. Compared with the common wavelet collocation methods, IWNM can decrease the boundary effect greatly. Compared with the finite difference method for the time fractional Fokker-Planck equation, IWNM can improve the calculation precision evidently. 1. Introduction The Fokker-Planck equation describes the time evolution of the probability density function of the velocity of a particle, and can be generalized to other observables as well. It is named after Adriaan Fokker and Max Planck and is also known as the Kolmogorov forward equation (diffusion), named after Andrey Kolmogorov, who first introduced it in a 1931 paper. When applied to particle position distributions, it is better known as the Smoluchowski equation. The case with zero diffusion is known in statistical mechanics as Liouville equation. In order to describe subdiffusive behavior of a particle under the combined influence of external nonlinear force field and a Boltzmann thermal heat bath, Metzler et al. introduced a fractional Fokker-Planck equation (FFPE) which was shown to obey generalized Einstein relations, and its stationary solution is the Boltzmann distribution [1]. Many methods for calculating nonlinear random response have been developed by numerous scholars over a long period of time. One type of these methods is the diffuseness process theory method, and the primarily one is Fokker-Planck equation method. In practice, the most difficult problem of using Fokker-Planck equation method is how to solve the equation. For general nonlinear system, it is very difficult to obtain the exact solution. Various numerical methods have been used to solve the Fokker-Planck equation, such as the weighted residual method [2], the finite element method [3], and the path integral method [4] and so on. The Galerkin method for the numerical solution of the stationary Fokker-Planck equation developed by Bhandari and Sherrer is based on taking multiple Hermite polynomial as joint probability density, but the rate of convergence of this method is slow for strong nonlinear system. Based on Galerkin method, a finite
The Genetic Distribution and Polymorphism Analysis of Antiviral Resistant Mx Gene Locus in Fifteen Chinese Indigenous Chicken Breeds
Tian Zhi-Quan,Wu Xiao-Wei,Sun Min,Yang Hai-Yan,Chang Guo-Bing,Ren Li-Wei,Li Bi-Chun
Journal of Animal and Veterinary Advances , 2012, DOI: 10.3923/javaa.2010.402.405
Abstract: The aim of this study was to examine Single Nucleotide Polymorphism (SNP) of resistant sequence in Mx gene in chicken with a mismatched Polymerase Chain Reaction-restriction Fragment Length Polymorphism (PCR-RFLP) method and thus, the differences of frequency on sequence A2032G in Mx gene in different breeds were detected. The results showed that three genotypes were found on A2032G in 15 breeds of chicken, which were AA, AG, GG and AA genotype was not found in Luyuan, Langshan chicken and Zhongyuan Game chicken, as GG genotype did in Chahua chicken and Red Jungle Fowl. The average frequency of resistance gene (A) and sensitive gene (G) was 0.350 and 0.650, respectively. However, the frequency of A alleles had a wide rangeability from 0.034-0.984 and the results of χ2-test indicated that Mx gene in all populations was in Hardy-Weinberg equilibrium.
Mechanical pain sensitivity of deep tissues in children - possible development of myofascial trigger points in children
Ting-I Han, Chang-Zern Hong, Fang-Chuan Kuo, Yueh-Ling Hsieh, Li-Wei Chou, Mu-Jung Kao
BMC Musculoskeletal Disorders , 2012, DOI: 10.1186/1471-2474-13-13
Abstract: Five hundreds and five healthy school children (age 4- 11 years) were investigated. A pressure algometer was used to measure the pressure pain threshold (PPT) at three different sites in the brachioradialis muscle: the lateral epicondyle at elbow (site A, assumed to be the A-TrP site), the mid-point of the muscle belly (site B, assumed to be the MTrP site), and the muscle-tendon junction as a control site (site C).The results showed that, for all children in this study, the mean PPT values was significantly lower (p < 0.05) at the assumed A-TrP site (site A) than at the other two sites, and was significantly lower (p < 0.05) at the assumed MTrP site (site B) than at the control site (site C). These findings are consistent if the data is analyzed for different genders, different dominant sides, and different activity levels.It is concluded that a child had increased sensitivity at the tendon attachment site and the muscle belly (endplate zone) after age of 4 years. Therefore, it is likely that a child may develop an A-Trp and a latent MTrP at the brachioradialis muscle after the age of 4 years. The changes in sensitivity, or the development for these trigger points, may not be related to the activity level of children aged 7-11 years. Further investigation is still required to indentify the exact timing of the initial occurrence of a-Trps and latent MTrPs.Myofascial trigger points (MTrPs) are a major cause of muscle pain in clinical practice. MTrPs are defined as a hyperirritable area in a taut band of skeletal muscle fibers that experience referred pain and local twitch responses. An active MTrP is painful either spontaneously or during movement, whereas a latent MTrP is painful only in response to pressure or compression (tenderness). MTrPs are characterized by an exquisite tender spot, a taut band, referred pain, a local twitch response, motor dysfunction, and an autonomic phenomenon [1]. Latent MTrPs can reportedly be activated by a lesion at other sites or withi
Is Two-dimensional PCA a New Technique?
关于二维主成分分析方法的研究

WANG Li-Wei,WANG Xiao,CHANG Ming,FENG Ju-Fu,
王立威
,王潇,常明,封举富

自动化学报 , 2005,
Abstract: The principal component analysis(PCA),or the eigenfaces method,is a de facto standard in human face recognition.Numerous algorithms tried to generalize PCA in different aspects.More recently,a technique called two-dimensional PCA(2DPCA)was proposed to cut the computational cost of the standard PCA.Unlike PCA that treats images as vectors,2DPCA views an image as a matrix.With a properly defined criterion,2DPCA results in an eigenvalue problem which has a much lower dimensionality than that of PCA.In this paper,we show that 2DPCA is equivalent to a special case of an existing feature extraction method,i.e.,the block-based PCA.Using the FERET database,extensive experimental results demonstrate that block-based PCA outperforms PCA on datasets that consist of relatively simple images for recognition,while PCA is more robust than 2DPCA in harder situations.
Validating Efficacy of Shea Nut Oil Extract in Knee Osteoarthritis Patients
San-Pei Chen,Sui-Foon Lo,Yu-Chia Wang,Tzu-Yi Chou,Kang-Ming Chang,Li-Wei Chou
Evidence-Based Complementary and Alternative Medicine , 2013, DOI: 10.1155/2013/147163
Abstract: Objectives. To examine and investigate the efficacy of shea nut oil extract (SheaFlex75) in relation to knee osteoarthritis (OA). Methods. Thirty-three patients (age years) with knee OA were recruited. Real-time ultrasound imaging and surface electromyography were used to objectively assess the morphological changes and the activity of vastus medialis oblique (VMO) muscles during a 16-week intervention of SheaFlex75. The intraclass correlation coefficient (ICC) was calculated to examine the reliability of the interscans. A paired-sample -test was used to compare the findings in different stages. The Spearman’s rank correlation coefficient was used to examine the relationship between the relevant variables of OA and percentage of thickness change of VMO at different contraction levels. Results. The baseline findings showed strong correlation, suggesting that the reliability of interscans at pretest was high. The ability to contract the muscles of the knee to a 30% contraction level showed significant change between the baseline and after 16-week testing, both in terms of morphological changes and muscle activity. Pain scale reported a significant decrease at the 16th week. Conclusion. The results suggest that SheaFlex75 can relieve the symptoms of knee OA and can result in improvement of muscle control of the knee. 1. Introduction Vitellaria paradoxa, commonly known as the “shea tree,” is a tree of Sapotaceae family, indigenous to Africa. The shea fruit consists of a thin, tart, nutritious pulp, surrounding a relatively large, oil-rich seed, from which “shea butter” is extracted. The butter has been used locally as food, providing a major source of dietary fat. In the West, shea butter is most commonly used in cosmetics [1, 2]. Extracts from the seed have also been used for the treatment of arthritic conditions [3, 4]. Osteoarthritis (OA), also known as degenerative arthritis, degenerative joint disease, and osteoarthrosis, is a group of mechanical abnormalities involving degradation of joints, including articular cartilage and subchondral bone. OA is the most common form of arthritis [5] and the leading cause of chronic disability which affects about twenty-seven million people in the United States [6, 7] and nearly 8 million people in the United Kingdom [7]. It most commonly affects the knee and has an impact on the health-related quality of life of the elderly [5]. Symptoms may include joint pain, tenderness over the inside of knee, stiffness, locking, reduced mobility, atrophy of lower extremities, and decreased walking speed. These functional
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