Browsing by Author "Wu, Chia-Chen"

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Evaluation of pedestrian transportation facilities in Taiwan using linear regression and support vector regression
(2017-01-01)
Chen, Shih-Huang
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Wu, Chia-Chen
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Li, Pei-Yi
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Paramitha, Putri Adhitana
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物理研究所
Walking is the most ancient and basic form of transportation. Any travel, long and short, will involve some form of walking. As societies continue to develop and population keeps growing, the level of services provided to accommodate this most basic form of transportation has become an indicator of the development stage of a society. In urban areas, sidewalk is the most utilised transportation facility for walking; therefore, conditions of sidewalks are an indication of the level of services provided to pedestrians. As Taiwan moves towards becoming a developed region, providing safe and pleasant facilities for pedestrian transportation has been an important goal for the government. In this study, the performance of sidewalks, located throughout Taiwan, was assessed. A total of 196 sidewalks, selected from 22 cities and counties, were evaluated. An expert panel, consisting of 6-8 people, was assembled to assess the sidewalk performance. The ratings developed from the survey were defined as the Sidewalk Serviceability Index (SSI) and were used to represent the performance of the sidewalks. Eight sidewalk characteristics were also measured in the field. The eight characteristics were original width, net width, vertical clearance, vertical drop-off, ramp slope, transverse cross slope, illuminance, and air temperature. Correlations between the SSI and the measured sidewalk characteristics were developed using statistical techniques.
Exploring Regulatory Mechanisms of Atrial Myocyte Hypertrophy of Mitral Regurgitation through Gene Expression Profiling Analysis: Role of NFAT in Cardiac Hypertrophy
(2016-12-01)
Chang, Tzu-Hao
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Chen, Mien-Cheng
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Chang, Jen-Ping
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Huang, Hsien-Da
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Ho, Wan-Chun
Background Left atrial enlargement in mitral regurgitation (MR) predicts a poor prognosis. The regulatory mechanisms of atrial myocyte hypertrophy of MR patients remain unknown. Methods and Results This study comprised 14 patients with MR, 7 patients with aortic valve disease (AVD), and 6 purchased samples from normal subjects (NC). We used microarrays, enrichment analysis and quantitative RT-PCR to study the gene expression profiles in the left atria. Microarray results showed that 112 genes were differentially up-regulated and 132 genes were differentially down-regulated in the left atria between MR patients and NC. Enrichment analysis of differentially expressed genes demonstrated that "NFAT in cardiac hypertrophy" pathway was not only one of the significant associated canonical pathways, but also the only one predicted with a non-zero score of 1.34 (i.e. activated) through Ingenuity Pathway Analysis molecule activity predictor. Ingenuity Pathway Analysis Global Molecular Network analysis exhibited that the highest score network also showed high association with cardiac related pathways and functions. Therefore, 5 NFAT associated genes (PPP3R1, PPP3CB, CAMK1, MEF2C, PLCE1) were studies for validation. The mRNA expressions of PPP3CB and MEF2C were significantly up-regulated, and CAMK1 and PPP3R1 were significantly down-regulated in MR patients compared to NC. Moreover, MR patients had significantly increased mRNA levels of PPP3CB, MEF2C and PLCE1 compared to AVD patients. The atrial myocyte size of MR patients significantly exceeded that of the AVD patients and NC. Conclusions Differentially expressed genes in the "NFAT in cardiac hypertrophy" pathway may play a critical role in the atrial myocyte hypertrophy of MR patients.
Idi1 and Hmgcs2 Are Affected by Stretch in HL-1 Atrial Myocytes
(2018-12-01)
Fang, Chih-Yuan
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Chen, Mien-Cheng
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Chang, Tzu-Hao
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Wu, Chia-Chen
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Chang, Jen-Ping
Background: Lipid expression is increased in the atrial myocytes of mitral regurgitation (MR) patients. This study aimed to investigate key regulatory genes and mechanisms of atrial lipotoxic myopathy in MR. Methods: The HL-1 atrial myocytes were subjected to uniaxial cyclic stretching for eight hours. Fatty acid metabolism, lipoprotein signaling, and cholesterol metabolism were analyzed by PCR assay (168 genes). Results: The stretched myocytes had significantly larger cell size and higher lipid expression than non-stretched myocytes (all p < 0.001). Fatty acid metabolism, lipoprotein signaling, and cholesterol metabolism in the myocytes were analyzed by PCR assay (168 genes). In comparison with their counterparts in non-stretched myocytes, seven genes in stretched monocytes (Idi1, Olr1, Nr1h4, Fabp2, Prkag3, Slc27a5, Fabp6) revealed differential upregulation with an altered fold change >1.5. Nine genes in stretched monocytes (Apoa4, Hmgcs2, Apol8, Srebf1, Acsm4, Fabp1, Acox2, Acsl6, Gk) revealed differential downregulation with an altered fold change <0.67. Canonical pathway analysis, using Ingenuity Pathway Analysis software, revealed that the only genes in the superpathway of cholesterol biosynthesis were Idi1 (upregulated) and Hmgcs2 (downregulated). The fraction of stretched myocytes expressing Nile red was significantly decreased by RNA interference of Idi1 (p < 0.05) and was significantly decreased by plasmid transfection of Hmgcs2 (p = 0.004). Conclusions: The Idi1 and Hmgcs2 genes have regulatory roles in atrial lipotoxic myopathy associated with atrial enlargement.
Loss of Heterozygosity of FCY2 Leading to the Development of Flucytosine Resistance in Candida tropicalis
(2011-06-01)
Chen, Yen-Ning
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Lo, Hsiu-Jung
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Wu, Chia-Chen
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Ko, Hui-Ching
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Chang, Te-Pin
As fluconazole resistance becomes an emerging issue for treating infections caused by Candida tropicalis, searching for alternative becomes a prominent task. In the present study, 97 clinical isolates of C. tropicalis were tested for the susceptibilities to flucytosine (5FC) with the Etest method. Although only one isolate was resistant to 5FC, 30 susceptible isolates could produce resistant progeny after exposure to the drug. Interestingly, 22 of these 30 clinical isolates had a heterozygous G/T at the 145th position on FCY2, encoding purine-cytosine permease, whereas their progeny recovered from within the inhibitory ellipses had homozygous T/T, resulting in null alleles for both copies of the gene and produced only truncated proteins, effecting the 5FC resistance. Furthermore, we found that two major fluconazole-resistant clinical clones, diploid sequence type 98 (DST98) and DST140, had a homozygous G/G at the 145th position, and neither was able to produce 5FC-resistant progeny within the inhibitory ellipses. Hence, strains of C. tropicalis containing heterozygous alleles may develop 5FC resistance readily, whereas those with homozygous G/G wild-type alleles can be treated with 5FC. Subsequently, a combination of 5FC and another antifungal drug is applicable for treating infections of C. tropicalis.