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Search Results: 1 - 10 of 120719 matches for " Wei-Jen Chen "
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Shockproof Experimental Study of Automated Stocker System in the High-Tech Factory  [PDF]
Jyh-Chau Wang, Jenn-Shin Hwang, Wei-Jen Lin, Fan-Ru Lin, Chin-Lian Tsai, Pin-Hong Chen
Open Journal of Earthquake Research (OJER) , 2013, DOI: 10.4236/ojer.2013.23006

This study, with the shake table experiments in the National Earthquake Engineering Research Center, investigated the seismic behavior of automation stocker system. The automation stocker system provided a fast and effective method for stocking products in the high-tech facilities. Firstly, the original machine tests for testing common stocker system were to investigate the seismic capacity and failing modes. Secondly, the team completed 2 kinds of reinforcement tests to investigate the seismic behavior: 1) the installation of bracing to improve overall stiffness; 2) the installation of the viscous dampers to improve the overall damping ratio. In comparing the results and performance of the three experiments, we learned from the results of the top-layer acceleration: the installation of bracing had the largest acceleration value, the original machine the second acceleration value and the damper the lowest acceleration value; the best effect was the installation of the damper. The result of the comparison of the top floor displacement meter showed that the highest data was the original machine; the second data was with the damper, the lowest data was the installation of the bracing. Based on the preliminary assessment on the best seismic retrofit ways of the storage system, we further examined the feasibility and applicability of automatic storage seismic retrofit in the high-tech factory.

Accelerating Computation of DCM for ERP in MATLAB by External Function Calls to the GPU
Wei-Jen Wang, I-Fan Hsieh, Chun-Chuan Chen
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0066599
Abstract: This study aims to improve the performance of Dynamic Causal Modelling for Event Related Potentials (DCM for ERP) in MATLAB by using external function calls to a graphics processing unit (GPU). DCM for ERP is an advanced method for studying neuronal effective connectivity. DCM utilizes an iterative procedure, the expectation maximization (EM) algorithm, to find the optimal parameters given a set of observations and the underlying probability model. As the EM algorithm is computationally demanding and the analysis faces possible combinatorial explosion of models to be tested, we propose a parallel computing scheme using the GPU to achieve a fast estimation of DCM for ERP. The computation of DCM for ERP is dynamically partitioned and distributed to threads for parallel processing, according to the DCM model complexity and the hardware constraints. The performance efficiency of this hardware-dependent thread arrangement strategy was evaluated using the synthetic data. The experimental data were used to validate the accuracy of the proposed computing scheme and quantify the time saving in practice. The simulation results show that the proposed scheme can accelerate the computation by a factor of 155 for the parallel part. For experimental data, the speedup factor is about 7 per model on average, depending on the model complexity and the data. This GPU-based implementation of DCM for ERP gives qualitatively the same results as the original MATLAB implementation does at the group level analysis. In conclusion, we believe that the proposed GPU-based implementation is very useful for users as a fast screen tool to select the most likely model and may provide implementation guidance for possible future clinical applications such as online diagnosis.
Mitogenomic Evidence for an Indo-West Pacific Origin of the Clupeoidei (Teleostei: Clupeiformes)
Sébastien Lavoué, Masaki Miya, Prachya Musikasinthorn, Wei-Jen Chen, Mutsumi Nishida
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0056485
Abstract: The clupeoid fishes are distributed worldwide, with marine, freshwater and euryhaline species living in either tropical or temperate environments. Regional endemism is important at the species and genus levels, and the highest species diversity is found in the tropical marine Indo-West Pacific region. The clupeoid distribution follows two general pattern of species richness, the longitudinal and latitudinal gradients. To test historical hypotheses explaining the formation of these two gradients, we have examined the early biogeography of the Clupeoidei in reconstructing the evolution of their habitat preferences along with their ancestral range distributions on a time-calibrated mitogenomic phylogeny. The phylogenetic results support the distinction of nine main lineages within the Clupeoidei, five of them new. We infer several independent transitions from a marine to freshwater environment and from a tropical to temperate environment that occurred after the initial diversification period of the Clupeoidei. These results combined with our ancestral range reconstruction hypothesis suggest that the probable region of origin and diversification of the Clupeoidei during the Cretaceous period was the tropical marine precursor to the present Indo-West Pacific region. Thus, our study favors the hypotheses of “Region of origin” and “Tropical conservatism” to explain the origins of the longitudinal and latitudinal gradients of clupeoid species richness, respectively. Additional geological and paleontological evidence further define the tropical marine paleo-region of origin as the eastern Tethys Sea region. The Cretaceous fossil record of the Clupeoidei is partially incongruent with the results here as it contains taxa found outside this region. We discuss three possible causes of conflict between our biogeographical hypothesis and the distributions of the Cretaceous clupeoid fossils: regional extinction, incomplete taxonomic sampling and incorrect timescale estimation.
Synthesis and Characterization of Novel Hybrid Poly(methyl methacrylate)/Iron Nanowires for Potential Hyperthemia Therapy  [PDF]
Huey-Wen Liou, Hong-Ming Lin, Yeu-Kuang Hwu, Wen-Chang Chen, Wei-Jen Liou, Li-Chung Lai, Wei-Syuan Lin, Wen-An Chiou
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2010, DOI: 10.4236/jbnb.2010.11007
Abstract: Externally applied magnetic fields have been used in this study to fabricate bamboo-like iron nanowires with or without a layer of Poly(methyl methacrylate) (PMMA). The hybrid PMMA/Fe nanowires were synthesized via hard X-ray synchrotron radiation polymerization with various treatment parameters. The results of XRD show that an oxide layer formed on the surface of the iron nanowires. The Fe2O3 and Fe3O4 phases coexist in the iron nanowires without X-ray irradiation. After X-ray irradiation, the Fe2O3 phase transformed into Fe3O4, which stabilized the iron nanowires. The results of XAS proved this phase transformation. TGA analysis confirmed the thermal properties and solid contents in these specimens. Their ferromagnetic behaviors were examined by magnetic hysteresis measurement, which indicated that the magnetic and structural properties of the nanowires can be manipulated by irradiation treatment. This may lead to a novel synthesis for iron nanowires that can be used in high thermal efficiency hyperthermia therapy.
New insights on early evolution of spiny-rayed fishes (Teleostei: Acanthomorpha)
Wei-Jen Chen,Francesco Santini,Jhen-Nien Chen,Shu-Hui Liu,Sébastien Lavoué
Frontiers in Marine Science , 2014, DOI: 10.3389/fmars.2014.00053
Abstract: The Acanthomorpha is the largest group of teleost fishes with about one third of extant vertebrate species. In the course of its evolution this lineage experienced several episodes of radiation, leading to a large number of descendant lineages differing profoundly in morphology, ecology, distribution and behavior. Although Acanthomorpha was recognized decades ago, we are only now beginning to decipher its large-scale, time-calibrated phylogeny, a prerequisite to test various evolutionary hypotheses explaining the tremendous diversity of this group. In this study, we provide new insights into the early evolution of the acanthomorphs and the euteleost allies based on the phylogenetic analysis of a newly developed dataset combining nine nuclear and mitochondrial gene markers. Our inferred tree is time-calibrated using 15 fossils, some of which have not been used before. While our phylogeny strongly supports a monophyletic Neoteleostei, Ctenosquamata (i.e., Acanthomorpha plus Myctophiformes), and Acanthopterygii, we find weak support (bootstrap value < 48%) for the traditionally defined Acanthomorpha, as well as evidence of non-monophyly for the traditional Paracanthopterygii, Beryciformes, and Percomorpha. We corroborate the new Paracanthopterygii sensu Miya et al. (2005) including Polymixiiformes, Zeiformes, Gadiformes, Percopsiformes, and likely the enigmatic Stylephorus chordatus. Our timetree largely agrees with other recent studies based on nuclear loci in inferring an Early Cretaceous origin for the acanthomorphs followed by a Late Cretaceous/Early Paleogene radiation of major lineages. This is in contrast to mitogenomic studies mostly inferring Jurassic or even Triassic ages for the origin of the acanthomorphs. We compare our results to those of previous studies, and attempt to address some of the issues that may have led to incongruence between the fossil record and the molecular clock studies, as well as between the different molecular timetrees.
Small-Molecule Synthetic Compound Norcantharidin Reverses Multi-Drug Resistance by Regulating Sonic Hedgehog Signaling in Human Breast Cancer Cells
Yu-Jen Chen, Cheng-Deng Kuo, Szu-Han Chen, Wei-Jen Chen, Wen-Chien Huang, K. S. Clifford Chao, Hui-Fen Liao
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0037006
Abstract: Multi-drug resistance (MDR), an unfavorable factor compromising treatment efficacy of anticancer drugs, involves upregulated ATP binding cassette (ABC) transporters and activated Sonic hedgehog (Shh) signaling. By preparing human breast cancer MCF-7 cells resistant to doxorubicin (DOX), we examined the effect and mechanism of norcantharidin (NCTD), a small-molecule synthetic compound, on reversing multidrug resistance. The DOX-prepared MCF-7R cells also possessed resistance to vinorelbine, characteristic of MDR. At suboptimal concentration, NCTD significantly inhibited the viability of DOX-sensitive (MCF-7S) and DOX-resistant (MCF-7R) cells and reversed the resistance to DOX and vinorelbine. NCTD increased the intracellular accumulation of DOX in MCF-7R cells and suppressed the upregulated the mdr-1 mRNA, P-gp and BCRP protein expression, but not the MRP-1. The role of P-gp was strengthened by partial reversal of the DOX and vinorelbine resistance by cyclosporine A. NCTD treatment suppressed the upregulation of Shh expression and nuclear translocation of Gli-1, a hallmark of Shh signaling activation in the resistant clone. Furthermore, the Shh ligand upregulated the expression of P-gp and attenuated the growth inhibitory effect of NCTD. The knockdown of mdr-1 mRNA had not altered the expression of Shh and Smoothened in both MCF-7S and MCF-7R cells. This indicates that the role of Shh signaling in MDR might be upstream to mdr-1/P-gp, and similar effect was shown in breast cancer MDA-MB-231 and BT-474 cells. This study demonstrated that NCTD may overcome multidrug resistance through inhibiting Shh signaling and expression of its downstream mdr-1/P-gp expression in human breast cancer cells.
Suppression of Heregulin-β1/HER2-Modulated Invasive and Aggressive Phenotype of Breast Carcinoma by Pterostilbene via Inhibition of Matrix Metalloproteinase-9, p38 Kinase Cascade and Akt Activation
Min-Hsiung Pan,Ying-Ting Lin,Chih-Li Lin,Chi-Shiang Wei,Chi-Tang Ho,Wei-Jen Chen
Evidence-Based Complementary and Alternative Medicine , 2011, DOI: 10.1093/ecam/nep093
Abstract: Invasive breast cancer is the major cause of death among females and its incidence is closely linked to HER2 (human epidermal growth factor receptor 2) overexpression. Pterostilbene, a natural analog of resveratrol, exerts its cancer chemopreventive activity similar to resveratrol by inhibiting cancer cell proliferation and inducing apoptosis. However, the anti-invasive effect of pterostilbene on HER2-bearing breast cancer has not been evaluated. Here, we used heregulin-β1 (HRG-β1), a ligand for HER3, to transactivate HER2 signaling. We found that pterostilbene was able to suppress HRG-β1-mediated cell invasion, motility and cell transformation of MCF-7 human breast carcinoma through down-regulation of matrix metalloproteinase-9 (MMP-9) activity and growth inhibition. In parallel, pterostilbene also inhibited protein and mRNA expression of MMP-9 driven by HRG-β1, suggesting that pterostilbene decreased HRG-β1-mediated MMP-9 induction via transcriptional regulation. Examining the signaling pathways responsible for HRG-β1-associated MMP-9 induction and growth inhibition, we observed that pterostilbene, as well as SB203580 (p38 kinase inhibitor), can abolish the phosphorylation of p38 mitogen-activated protein kinase (p38 kinase), a downstream HRG-β1-responsive kinase responsible for MMP-9 induction. In addition, HRG-β1-driven Akt phosphorylation required for cell proliferation was also suppressed by pterostilbene. Taken together, our present results suggest that pterostilbene may serve as a chemopreventive agent to inhibit HRG-β1/HER2-mediated aggressive and invasive phenotype of breast carcinoma through down-regulation of MMP-9, p38 kinase and Akt activation.
Understanding the Biocompatibility of Sintered Calcium Phosphate with Ratio of [Ca]/[P] = 1.50
Feng-Lin Yen,Wei-Jen Shih,Min-Hsiung Hon,Hui-Ting Chen,I-Ming Hung,Homg-Huey Ko,Moo-Chin Wang
Journal of Nanomaterials , 2012, DOI: 10.1155/2012/325605
Abstract: Biocompatibility of sintered calcium phosphate pellets with [Ca]/[P] = 1.50 was determined in this study. Calcium pyrophosphate (CPP) phase formed on the sintered pellets immersed in a normal saline solution for 14?d at 37°C. The intensities of hydroxyapatite (HA) reflections in the X-ray diffraction (XRD) patterns of the pellets were retrieved to as-sintered state. The pellet surface morphology shows that CPP crystallites were clearly present and make an amorphous calcium phosphate (ACP) to discriminate against become to the area of slice join together. In addition, the intensities of the CPP reflections in the XRD patterns were the highest when the pellets were immersed for 28?d. When the CPP powders were extracted from the pellets after immersion in the solution for 14?d, the viability of 3T3 cells remained above 90% for culture times from 1 to 4?d. The pellet surface morphology observed using optical microscopy showed that the cells did not adhere to the bottom of the sintered pellets when cultured for 4?d; however, some CPP phase precipitates were formed, as confirmed by XRD. In consequence, the results suggest that the sintered HA powders are good materials for use in biomedical applications because of their good biocompatibility. 1. Introduction Among calcium phosphate-based ceramics, hydroxyapatite (HA, Ca10(PO4)6(OH)2) and β-tricalcium phosphate (β-TCP, β-Ca3(PO4)2) are the most commonly used as bio-resorbable materials and tissue-engineering scaffolds [1–3] because these ceramics are biocompatible, nontoxic, and resorbable, and because they exhibit excellent osteoconductive ability. HA has widely been used as bone cement and implant material for direct bone-to-bone grafts [4–6]. Nevertheless, natural bone is a nanocomposite combination consisting of an organic fraction and a mineral fraction containing a small amount of apatite crystals and nonstoichiometric calcium phosphate, which jointly confer mechanical resistance [7]. Therefore, applications of HA are currently limited to powders, coatings, porous bodies, and non-load-bearing implants owing to process difficulties and to the poor mechanical properties of conventional HA also reported by Suchanek and Yoshimura [8]. Prepared nanosized HA has received much attention in recent years for simulating natural structures [9–11]. Nanoscale-engineered HA would exhibit amazing functional properties owing to its small crystallite size, large surface area to volume ratio, and ultrafine structure similar to that of biological apatite, which would have a great effect on the interaction of cells
Changes in the Nasal Colonization with Methicillin-Resistant Staphylococcus aureus in Children: 2004-2009
Wen-Tsung Lo,Chih-Chien Wang,Wei-Jen Lin,Sheng-Ru Wang,Ching-Shen Teng,Ching-Feng Huang,Shyi-Jou Chen
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0015791
Abstract: Staphylococcus aureus is an important cause of infection, particularly in persons colonized with this organism. This study compared the annual prevalence and microbiological characteristics of methicillin-resistant S. aureus (MRSA) nasal colonization in Taiwanese children from 2004 through 2009. Risk factors for MRSA were determined for the overall study period.
Biofunctional Constituents from Liriodendron tulipifera with Antioxidants and Anti-Melanogenic Properties
Wei-Jen Li,Yi-Chieh Lin,Pei-Fang Wu,Zhi-Hong Wen,Po-Len Liu,Chung-Yi Chen,Hui-Min Wang
International Journal of Molecular Sciences , 2013, DOI: 10.3390/ijms14011698
Abstract: From the stems of Liriodendron tulipifera, seventeen known compounds have been extracted, isolated and purified. By using spectroscopic analysis, the structures of these pure constituents were determined as three lignans, four steroids and ten benzenoids. Identified compounds were screened for antioxidant abilities using: 1,1-diphenyl-2-picrylhydrazul (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging free radical activity assays; metal chelating power test; and ferric reducing/antioxidant power (FRAP) examination. The result revealed that seventeen compounds had potential anti-oxidative capabilities. In addition, the anti-tyrosinase effect was determined by calculating the hydroxylation of L-tyrosine to L-dopa and the oxidization of L-dopa to dopaquinone, according to in vitro mushroom tyrosinase evaluation platform. Furthermore, based on assays on B16F10 cell line, our data suggest that five compounds isolated from L. tulipifera would be able to inhibit tyrosinase activity and reduce the melanin content in animal cells. Therefore, some of the examined compounds could be potentially used in the cosmetic skin whitening business, therapeutic applications or the food industry.
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