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Search Results: 1 - 10 of 478772 matches for " Chun-Chieh A Shih "
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Feature Extraction Techniques of Non-Stationary Signals for Fault Diagnosis in Machinery Systems  [PDF]
Chun-Chieh Wang, Yuan Kang
Journal of Signal and Information Processing (JSIP) , 2012, DOI: 10.4236/jsip.2012.31002
Abstract: Previously, fault diagnosis of fixed or steady state mechanical failures (e.g., pumps in nuclear power plant turbines, engines or other key equipment) applied spectrum analysis (e.g., fast Fourier transform, FFT) to extract the frequency features as the basis for identifying the causes of failure types. However, mechanical equipment for increasingly instant speed variations (e.g., wind turbine transmissions or the mechanical arms used in 3C assemblies, etc.) mostly generate non-stationary signals, and the signal features must be averaged with analysis time which makes it difficult to identify the causes of failures. This study proposes a time frequency order spectrum method combining the short-time Fourier transform (STFT) and speed frequency order method to capture the order features of non-stationary signals. Such signal features do not change with speed, and are thus effective in identifying faults in mechanical components under non-stationary conditions. In this study, back propagation neural networks (BPNN) and time frequency order spectrum methods were used to verify faults diagnosis and obtained superior diagnosis results in non-stationary signals of gear-rotor systems.
Synergistic Interactions between Alzheimer’s Aβ40 and Aβ42 on the Surface of Primary Neurons Revealed by Single Molecule Microscopy
Chun-Chieh Chang, John Christian Althaus, Cynthia J. L. Carruthers, Michael A. Sutton, Duncan G. Steel, Ari Gafni
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0082139
Abstract: Two amyloid-β peptides (Aβ40 and Aβ42) feature prominently in the extracellular brain deposits associated with Alzheimer’s disease. While Aβ40 is the prevalent form in the cerebrospinal fluid, the fraction of Aβ42 increases in the amyloid deposits over the course of disease development. The low in vivo concentration (pM-nM) and metastable nature of Aβ oligomers have made identification of their size, composition, cellular binding sites and mechanism of action challenging and elusive. Furthermore, recent studies have suggested that synergistic effects between Aβ40 and Aβ42 alter both the formation and stability of various peptide oligomers as well as their cytotoxicity. These studies often utilized Aβ oligomers that were prepared in solution and at μM peptide concentrations. The current work was performed using physiological Aβ concentrations and single-molecule microscopy to follow peptide binding and association on primary cultured neurons. When the cells were exposed to a 1:1 mixture of nM Aβ40:Aβ42, significantly larger membrane-bound oligomers developed compared to those formed from either peptide alone. Fluorescence resonance energy transfer experiments at the single molecule level reveal that these larger oligomers contained both Aβ40 and Aβ42, but that the growth of these oligomers was predominantly by addition of Aβ42. Both pure peptides form very few oligomers larger than dimers, but either membrane bound Aβ40/42 complex, or Aβ40, bind Aβ42 to form increasingly larger oligomers. These findings may explain how Aβ42-dominant oligomers, suspected of being more cytotoxic, develop on the neuronal membrane under physiological conditions.
Functional characterization of cellulases identified from the cow rumen fungus Neocallimastix patriciarum W5 by transcriptomic and secretomic analyses
Tzi-Yuan Wang, Hsin-Liang Chen, Mei-Yeh J Lu, Yo-Chia Chen, Huang-Mo Sung, Chi-Tang Mao, Hsing-Yi Cho, Huei-Mien Ke, Teh-Yang Hwa, Sz-Kai Ruan, Kuo-Yen Hung, Chih-Kuan Chen, Jeng-Yi Li, Yueh-Chin Wu, Yu-Hsiang Chen, Shao-Pei Chou, Ya-Wen Tsai, Te-Chin Chu, Chun-Chieh A Shih, Wen-Hsiung Li, Ming-Che Shih
Biotechnology for Biofuels , 2011, DOI: 10.1186/1754-6834-4-24
Abstract: We have developed an efficient platform that uses a combination of transcriptomic and proteomic approaches to N. patriciarum to accelerate gene identification, enzyme classification and application in rice straw degradation. By conducting complementary studies of transcriptome (Roche 454 GS and Illumina GA IIx) and secretome (ESI-Trap LC-MS/MS), we identified 219 putative GH contigs and classified them into 25 GH families. The secretome analysis identified four major enzymes involved in rice straw degradation: β-glucosidase, endo-1,4-β-xylanase, xylanase B and Cel48A exoglucanase. From the sequences of assembled contigs, we cloned 19 putative cellulase genes, including the GH1, GH3, GH5, GH6, GH9, GH18, GH43 and GH48 gene families, which were highly expressed in N. patriciarum cultures grown on different feedstocks.These GH genes were expressed in Pichia pastoris and/or Saccharomyces cerevisiae for functional characterization. At least five novel cellulases displayed cellulytic activity for glucose production. One β-glucosidase (W5-16143) and one exocellulase (W5-CAT26) showed strong activities and could potentially be developed into commercial enzymes.Cellulosic ethanol produced by microbial fermentation from feedstocks has been proposed to replace fossil fuels in transportation. A key step in cellulosic ethanol production is to break down cellulose into glucose and hemicellulose into xylose, which can subsequently be converted into ethanol by fermentative microbes. Therefore, finding efficient cellulases is important to bioethanol production, as well as for hydrolyzing feedstocks into sugars in general. Neocallimastix species is one of the major anaerobic fungi in the rumen of water buffalo capable of efficiently digesting cellulosic biomass [1-4]. Such anaerobic fungi are potential sources for highly active cellulolytic enzymes that are useful for cellulose hydrolysis [5-7]. Plant cell wall degrading enzymes from rumen fungi such as Neocallimastix patriciarum may
Revealing the Anti-Tumor Effect of Artificial miRNA p-27-5p on Human Breast Carcinoma Cell Line T-47D
Chien-Wei Tseng,Hsuan-Cheng Huang,Arthur Chun-Chieh Shih,Ya-Ya Chang,Chung-Cheng Hsu,Jen-Yun Chang,Wen-Hsiung Li,Hsueh-Fen Juan
International Journal of Molecular Sciences , 2012, DOI: 10.3390/ijms13056352
Abstract: microRNAs (miRNAs) cause mRNA degradation or translation suppression of their target genes. Previous studies have found direct involvement of miRNAs in cancer initiation and progression. Artificial miRNAs, designed to target single or multiple genes of interest, provide a new therapeutic strategy for cancer. This study investigates the anti-tumor effect of a novel artificial miRNA, miR P-27-5p, on breast cancer. In this study, we reveal that miR P-27-5p downregulates the differential gene expressions associated with the protein modification process and regulation of cell cycle in T-47D cells. Introduction of this novel artificial miRNA, miR P-27-5p, into breast cell lines inhibits cell proliferation and induces the first “gap” phase (G1) cell cycle arrest in cancer cell lines but does not affect normal breast cells. We further show that miR P-27-5p targets the 3′-untranslated mRNA region (3′-UTR) of cyclin-dependent kinase 4 (CDK4) and reduces both the mRNA and protein level of CDK4, which in turn, interferes with phosphorylation of the retinoblastoma protein (RB1). Overall, our data suggest that the effects of miR p-27-5p on cell proliferation and G1 cell cycle arrest are through the downregulation of CDK4 and the suppression of RB1 phosphorylation. This study opens avenues for future therapies targeting breast cancer.
Construction of Wind Turbine Bearing Vibration Monitoring and Performance Assessment System  [PDF]
Feng-Tai Wu, Chun-Chieh Wang, Jui-Hung Liu, Chia-Ming Chang, Ya-Ping Lee
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.44055
Abstract:

This study is primary to develop relevant techniques for the bearing of wind turbine, such as the intelligent monitoring system, the performance assessment, future trend prediction and possible fault classification etc. The main technique of system monitoring and diagnosis is divided into three algorithms, such as the performance assessment, performance prediction and fault diagnosis, respectively. Among them, the Logistic Regression (LR) is adopted to assess the bearing performance condition, the Autoregressive Moving Average (ARMA) is adopted to predict the future variation trend of bearing, and the Support Vector Machine (SVM) is adopted to classify and diagnose the possible fault of bearing. Through testing, this intelligent monitoring system can achieve real-time vibration monitoring, current performance assessment, future performance trend prediction and possible fault classification for the bearing of wind turbine. The monitor and analysis data and knowledge not only can be used as the basis of predictive maintenance, but also can be stored in the database for follow-up off-line analysis and used as the reference for improvement of operation parameter and wind turbine system design.

Extracellular matrix of dental pulp stem cells: applications in pulp tissue engineering using somatic MSCs
Sriram Ravindran,Chun-Chieh Huang,Anne George
Frontiers in Physiology , 2014, DOI: 10.3389/fphys.2013.00395
Abstract: Dental Caries affects approximately 90% of the world's population. At present, the clinical treatment for dental caries is root canal therapy. This treatment results in loss of tooth sensitivity and vitality. Tissue engineering can potentially solve this problem by enabling regeneration of a functional pulp tissue. Dental pulp stem cells (DPSCs) have been shown to be an excellent source for pulp regeneration. However, limited availability of these cells hinders its potential for clinical translation. We have investigated the possibility of using somatic mesenchymal stem cells (MSCs) from other sources for dental pulp tissue regeneration using a biomimetic dental pulp extracellular matrix (ECM) incorporated scaffold. Human periodontal ligament stem cells (PDLSCs) and human bone marrow stromal cells (HMSCs) were investigated for their ability to differentiate toward an odontogenic lineage. In vitro real-time PCR results coupled with histological and immunohistochemical examination of the explanted tissues confirmed the ability of PDLSCs and HMSCs to form a vascularized pulp-like tissue. These findings indicate that the dental pulp stem derived ECM scaffold stimulated odontogenic differentiation of PDLSCs and HMSCs without the need for exogenous addition of growth and differentiation factors. This study represents a translational perspective toward possible therapeutic application of using a combination of somatic stem cells and extracellular matrix for pulp regeneration.
Decreased Risk of Stroke in Patients with Traumatic Brain Injury Receiving Acupuncture Treatment: A Population-Based Retrospective Cohort Study
Chun-Chuan Shih, Yi-Ting Hsu, Hwang-Huei Wang, Ta-Liang Chen, Chin-Chuan Tsai, Hsin-Long Lane, Chun-Chieh Yeh, Fung-Chang Sung, Wen-Ta Chiu, Yih-Giun Cherng, Chien-Chang Liao
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0089208
Abstract: Background Patients with traumatic brain injury (TBI) face increased risk of stroke. Whether acupuncture can help to protect TBI patients from stroke has not previously been studied. Methods Taiwan's National Health Insurance Research Database was used to conduct a retrospective cohort study of 7409 TBI patients receiving acupuncture treatment and 29,636 propensity-score-matched TBI patients without acupuncture treatment in 2000–2008 as controls. Both TBI cohorts were followed until the end of 2010 and adjusted for immortal time to measure the incidence and adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of new-onset stroke in the multivariable Cox proportional hazard models. Results TBI patients with acupuncture treatment (4.9 per 1000 person-years) had a lower incidence of stroke compared with those without acupuncture treatment (7.5 per 1000 person-years), with a HR of 0.59 (95% CI = 0.50–0.69) after adjustment for sociodemographics, coexisting medical conditions and medications. The association between acupuncture treatment and stroke risk was investigated by sex and age group (20–44, 45–64, and ≥65 years). The probability curve with log-rank test showed that TBI patients receiving acupuncture treatment had a lower probability of stroke than those without acupuncture treatment during the follow-up period (p<0.0001). Conclusion Patients with TBI receiving acupuncture treatment show decreased risk of stroke compared with those without acupuncture treatment. However, this study was limited by lack of information regarding lifestyles, biochemical profiles, TBI severity, and acupuncture points used in treatments.
Three-Terminal Amorphous Silicon Solar Cells
Cheng-Hung Tai,Chu-Hsuan Lin,Chih-Ming Wang,Chun-Chieh Lin
International Journal of Photoenergy , 2011, DOI: 10.1155/2011/813093
Abstract: Many defects exist within amorphous silicon since it is not crystalline. This provides recombination centers, thus reducing the efficiency of a typical a-Si solar cell. A new structure is presented in this paper: a three-terminal a-Si solar cell. The new back-to-back p-i-n/n-i-p structure increased the average electric field in a solar cell. A typical a-Si p-i-n solar cell was also simulated for comparison using the same thickness and material parameters. The 0.28?μm-thick three-terminal a-Si solar cell achieved an efficiency of 11.4%, while the efficiency of a typical a-Si p-i-n solar cell was 9.0%. Furthermore, an efficiency of 11.7% was achieved by thickness optimization of the three-terminal solar cell. 1. Introduction Amorphous silicon (a-Si) for photovoltaic applications can be deposited using the techniques of plasma-enhanced chemical vapor deposition (PECVD) [1–3], catalytic CVD (Cat-CVD) [4, 5], photo-CVD [6, 7], sputtering [8], and so forth. Since it is usually deposited at a low temperature, low-cost or flexible materials like glass, plastic, or stainless steel can be adopted as the substrate. Amorphous Si also has the advantages of an abundant supply on the earth and a high-absorption coefficient at visible wavelengths [9, 10]. These advantages make it promising for applications in thin-film photovoltaics. Amorphous Si can be applied to many types of solar cells, such as single-junction [11, 12], multijunction [13, 14], and HIT [15] (heterojunction with intrinsic thin layer) solar cells. In 2000, the stable efficiency of a single-junction a-Si solar cell (area of 1?cm2) was 9.0% [16]. In 2009. a single-junction a-Si solar cell has achieved an efficiency of 10.1% [17]. Multijunction solar cells were usually able to achieve higher efficiencies. For example, the stable efficiency of a triple-junction solar cell (a-Si/a-Si/a-SiGe tandem solar cell) was 12.1% [18], and the efficiencies of micromorph Si solar cells (a-Si/μc-Si tandem solar cells) were larger than 11% [19–21]. Multijunction solar cells are composed of two or more subcells. The working mechanism of multijunction solar cells is by way of tunnel-recombination junctions, and the final efficiency is limited by the smallest photogenerated current among all subcells [22]. This is because each subcell of a multijunction solar cell must pass through the same current. Therefore, the defects inside the a-Si may reduce the efficiencies of solar cells whether for a single-junction cell or a multijunction cell. The efficiencies are reduced due to the recombination of photogenerated carriers via
Current Research and Development of Chemotherapeutic Agents for Melanoma
Kyaw Minn Hsan,Chun-Chieh Chen,Lie-Fen Shyur
Cancers , 2010, DOI: 10.3390/cancers2020397
Abstract: Cutaneous malignant melanoma is the most lethal form of skin cancer and an increasingly common disease worldwide. It remains one of the most treatment-refractory malignancies. The current treatment options for patients with metastatic melanoma are limited and in most cases non-curative. This review focuses on conventional chemotherapeutic drugs for melanoma treatment, by a single or combinational agent approach, but also summarizes some potential novel phytoagents discovered from dietary vegetables or traditional herbal medicines as alternative options or future medicine for melanoma prevention. We explore the mode of actions of these natural phytoagents against metastatic melanoma.
Transmission X-ray Microscopy—A New Tool in Clay Mineral Floccules Characterization
Marek S. ?bik,Yen-Fang Song,Ray L. Frost,Chun-Chieh Wang
Minerals , 2012, DOI: 10.3390/min2040283
Abstract: Effective flocculation and dewatering of mineral processing streams containing clays are microstructure dependent in clay-water systems. Initial clay flocculation is crucial in the design and for the development of a new methodology of gas exploitation. Microstructural engineering of clay aggregates using covalent cations and Keggin macromolecules have been monitored using the new state of the art Transmission X-ray Microscope (TXM) with 60 nm tomography resolution installed in a Taiwanese synchrotron. The 3-D reconstructions from TXM images show complex aggregation structures in montmorillonite aqueous suspensions after treatment with Na +, Ca 2+ and Al 13 Keggin macromolecules. Na-montmorillonite displays elongated, parallel, well-orientated and closed-void cellular networks, 0.5–3 μm in diameter. After treatment by covalent cations, the coagulated structure displays much smaller, randomly orientated and openly connected cells, 300–600 nm in diameter. The average distances measured between montmorillonite sheets was around 450 nm, which is less than half of the cell dimension measured in Na-montmorillonite. The most dramatic structural changes were observed after treatment by Al 13 Keggin; aggregates then became arranged in compacted domains of a 300 nm average diameter composed of thick face-to-face oriented sheets, which forms porous aggregates with larger intra-aggregate open and connected voids.
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