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Search Results: 1 - 10 of 67765 matches for " Yi-Jhen Wu "
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Metabolomic Studies Using High Performance Liquid Chromatography and Tandem Mass Spectrometry to Discover Quality Markers for Oriental Beauty (Dongfang Meiren) Tea  [PDF]
Yi-Hong Chen, Yu-Hui Liu, Yi-Jhen Wu, Chu-Chin Chen
Food and Nutrition Sciences (FNS) , 2014, DOI: 10.4236/fns.2014.59092
Abstract:

In this study, a high-performance liquid chromatograph and an electrospray ionization (ESI) triple quadrupole mass spectrometry (TQ MS) detector were used to scan Oriental Beauty tea of different grades and prices. Principle component analysis (PCA) of the profiling data was performed for pattern recognition, clearly showing that the proposed MS profiling method was able to classify Oriental Beauty tea into different grades. The component mass ions primarily responsible for the separation were selected with high loading strength in the PCA for subsequent identification with tandem mass (MS/MS). Caffeine, citrate and salicylate were verified, whereas certain other compounds remained ambiguous. Regression analysis considering caffeine, citrate and salicylate showed a linear relationship between the prices of the Oriental Beauty tea with an adjusted R2 of 0.84. If all the selected marker ions (in addition to caffeine, citrate and salicylate) could have been identified and incorporated into regression analysis, a stronger relationship could have been confirmed. These results suggest that metabolomics can facilitate the determination of real markers in the quality control of Oriental Beauty tea, and may lead to the further application of metabolomics in other food quality controls.

Reducing Colorectal Cancer Incidence and Disparities: Performance and Outcomes of a Screening Colonoscopy Program in South Carolina
Sudha Xirasagar,Yi-Jhen Li,James B. Burch,Virginie G. Daguisé,Thomas G. Hurley,James R. Hébert
Advances in Public Health , 2014, DOI: 10.1155/2014/787282
Abstract: This study evaluated the efficiency, effectiveness, and racial disparities reduction potential of Screening Colonoscopies for People Everywhere in South Carolina (SCOPE SC), a state-funded program for indigent persons aged 50–64 years (45–64 years for African American (AA)) with a medical home in community health centers. Patients were referred to existing referral network providers, and the centers were compensated for patient navigation. Data on procedures and patient demographics were analyzed. Of 782 individuals recruited (71.2% AA), 85% (665) completed the procedure (71.1% AA). The adenoma detection rate was 27.8% (males 34.6% and females 25.1%), advanced neoplasm rate 7.7% (including 3 cancers), cecum intubation rate 98.9%, inadequate bowel preparation rate 7.9%, and adverse event rate 0.9%. All indicators met the national quality benchmarks. The adenoma rate of 26.0% among AAs aged 45–49 years was similar to that of older Whites and AAs. We found that patient navigation and a medical home setting resulted in a successful and high-quality screening program. The observed high adenoma rate among younger AAs calls for more research with larger cohorts to evaluate the appropriateness of the current screening guidelines for AAs, given that they suffer 47% higher colorectal cancer mortality than Whites. 1. Introduction There is wide variation across population subgroups in cancer incidence, mortality, or both. Nationally in the United States of America, African Americans (AAs) have ≈17% higher colorectal cancer (CRC) incidence and ≈47% higher mortality than Whites [1]. AAs also are diagnosed at younger ages, on average and with later-stage disease, have a higher incidence before the recommended screening age of 50 years, and tend to have worse prognoses even after accounting for other factors [2, 3]. These disparities tend to be much larger in South Carolina (SC) than in the US average [4, 5]. The majority of CRCs in average-risk individuals arise from the polyp-to-cancer pathway, which translates into an opportunity to prevent cancers by removing polyps detected through screening age-appropriate adults. Of all cancer screening tests, colonoscopy is the most effective both for early detection and, more importantly, for primary prevention of CRC because it enables removal of precancerous polyps before they turn cancerous. Colonoscopy has some disadvantages, however. It requires specially trained physicians and is expensive and invasive, requiring a well-equipped and well-staffed facility for safe, high-quality performance. Consequently, health insurance
A Real-Time Measurement Algorithm for Available Bandwidth  [PDF]
Yi YIN, Weidong WU
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2009, DOI: 10.4236/ijcns.2009.28086
Abstract: Available bandwidth estimation is useful for route selection in overlay networks, QoS, and traffic engineer-ing. Many measurement algorithms, such as Pathload, Pathchar, and Packet Transmission Rate (PTR) method, etc. have been proposed. PTR method sends a sequence of packet trains to characterize the interac-tion between probing packets and the competing traffic, and uses the average rate of the packet train as an estimate of the available bandwidth. However, this PTR algorithm does not fully consider the situation that the detection packets lost themselves. This paper improves the original PTR algorithm which considers the specialty of the burst of the network background flow. The improved PTR algorithm uses the method to match the initial gap value and gap step value to solve the problem about the burst of background flow, and the improved PTR algorithm record and control the number of packets with source and destination to solve the lost of some packets. Finally, theory and experiments, verified by the improved algorithm of PTR, can reflect the changes of the network stably and timely under the circumstance of the network fluctuates fre-quently. It improves the accuracy of a network measurement and makes the measurement results, which can reflect the changes of the network more clearly.
Parameter Optimization for Amplify-and-Forward Relaying Systems with Pilot Symbol Assisted Modulation Scheme  [PDF]
Yi WU, Matthias PATZOLD
Wireless Sensor Network (WSN) , 2009, DOI: 10.4236/wsn.2009.11003
Abstract: Cooperative diversity is a promising technology for future wireless networks. In this paper, we consider a cooperative communication system operating in an amplify-and-forward (AF) mode with a pilot symbol as-sisted modulation (PSAM) scheme. It is assumed that a linear minimum mean square estimator (LMMSE) is used for the channel estimation at the receiver. A simple and easy-to-evaluate asymptotical upper bound (AUB) of the symbol-error-rate (SER) is derived for uncoded AF cooperative communication systems with quadrature amplitude modulation (QAM) constellations. Based on the AUB, we propose a criterion for the parameter optimization in the PSAM scheme. We discuss how the pilot spacing and the length of the Wiener ?lter should be chosen under the constraint of a tradeoff between pilot overhead, estimation accuracy, and receiver complexity. We also formulate an power allocation problem for the considered system. It is shown that the power allocation problem can optimally be solved by means of a gradient search method. Numerical simulations are presented to verify the correctness of the theoretical results and to demonstrate the benefits of the parameter optimization.
L-Ascorbate Attenuates the Endotoxin-Induced Production of Inflammatory Mediators by Inhibiting MAPK Activation and NF-κB Translocation in Cortical Neurons/Glia Cocultures
Ya-Ni Huang, Chien-Cheng Lai, Chien-Tsai Chiu, Jhen-Jhe Lin, Jia-Yi Wang
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0097276
Abstract: In response to acute insults to the central nervous system, such as pathogen invasion or neuronal injuries, glial cells become activated and secrete inflammatory mediators such as nitric oxide (NO), cytokines, and chemokines. This neuroinflammation plays a crucial role in the pathophysiology of chronic neurodegenerative diseases. Endogenous ascorbate levels are significantly decreased among patients with septic encephalopathy. Using the bacterial endotoxin lipopolysaccharide (LPS) to induce neuroinflammation in primary neuron/glia cocultures, we investigated how L-ascorbate (vitamin C; Vit. C) affected neuroinflammation. LPS (100 ng/ml) induced the expression of inducible NO synthase (iNOS) and the production of NO, interleukin (IL)-6, and macrophage inflammatory protein-2 (MIP-2/CXCL2) in a time-dependent manner; however, cotreatment with Vit. C (5 or 10 mM) attenuated the LPS-induced iNOS expression and production of NO, IL-6, and MIP-2 production. The morphological features revealed after immunocytochemical staining confirmed that Vit. C suppressed LPS-induced astrocytic and microglial activation. Because Vit. C can be transported into neurons and glia via the sodium-dependent Vit. C transporter-2, we examined how Vit. C affected LPS-activated intracellular signaling in neuron/glia cocultures. The results indicated the increased activation (caused by phosphorylation) of mitogen-activated protein kinases (MAPKs), such as p38 at 30 min and extracellular signal-regulated kinases (ERKs) at 180 min after LPS treatment. The inhibition of p38 and ERK MAPK suppressed the LPS-induced production of inflammatory mediators. Vit. C also inhibited the LPS-induced activation of p38 and ERK. Combined treatments of Vit. C and the inhibitors of p38 and ERK yielded no additional inhibition compared with using the inhibitors alone, suggesting that Vit. C functions through the same signaling pathway (i.e., MAPK) as these inhibitors. Vit. C also reduced LPS-induced IκB-α degradation and NF-κB translocation. Thus, Vit. C suppressed the LPS-stimulated production of inflammatory mediators in neuron/glia cocultures by inhibiting the MAPK and NF-κB signaling pathways.
Human pituitary tumor-transforming gene 1 overexpression reinforces oncogene-induced senescence through CXCR2/p21 signaling in breast cancer cells
Jhen-Wei Ruan, Yi-Chu Liao, Ingrid Lua, Ming-Hsun Li, Chih-Yi Hsu, Ji-Hshiung Chen
Breast Cancer Research , 2012, DOI: 10.1186/bcr3226
Abstract: MCF-10A and MCF-7 cells were used to identify the mechanism of hPTTG1-induced senescence. The interplay between hPTTG1 overexpression and chemokine C-X-C motif receptor 2 (CXCR2)/p21-dependent senescence in tumor growth and metastasis of MCF-7 cells was investigated by orthotopic transplantation of severe combined immunodeficiency (SCID) mice. Additionally, human invasive ductal carcinoma (IDC) tissue arrays were used to confirm the hPTTG1/CXCR2/p21 axis established in vitro.In this study, we investigated the mechanism of hPTTG1-induced senescence as well as its role in breast cancer progression and metastasis. Herein, we showed that hPTTG1 overexpression reinforced senescence through the CXCR2/p21 signaling. Furthermore, hPTTG1 overexpression activated NF-κB signaling to transactivate the expression of interleukin (IL)-8 and growth-regulated oncogene alpha (GROα) to execute CXCR2 signaling in MCF-7 cells. When CXCR2 expression was knocked down in hPTTG1-overexpressing MCF-7 cells, hPTTG1-induced senescence was abrogated by alleviating CXCR2-induced p21 expression. In a mouse model, CXCR2-mediated senescence limited hPTTG1-induced tumor growth and metastasis. Moreover, CXCR2 knockdown in hPTTG1-overexpressing MCF-7 tumors dramatically accelerated tumor growth and metastasis. Our in vitro and in vivo results demonstrated that hPTTG1 overexpression reinforces senescence through CXCR2 signaling, and the evasion of CXCR2/p21-dependent senescence was critical to hPTTG1 exerting its oncogenic potential. Interestingly, although CXCR2-dependent senescence restrained hPTTG1-induced tumor progression, when MCF-7 cells and hPTTG1-overexpressing MCF-7 cells were co-transplanted into the mammary fat pads of SCID mice, hPTTG1-overexpressing senescent cells created a metastasis-promoting microenvironment that promoted lung metastasis of the MCF-7 cells. Immunohistochemical analysis of human breast tumor samples also confirmed the importance of the hPTTG1/CXCR2 axis in promoting br
Urbanization, Social Mobility, and the Construction of Family Property Relations in a Village Community in Southwest China  [PDF]
Yi Wu
Advances in Anthropology (AA) , 2019, DOI: 10.4236/aa.2019.93011
Abstract: Based on field data collected in a village community in Southwest China during the first decade of the new millennium, this paper shows that urbanization and increased social mobility contributed to growing awareness of individual rights and changing norms regarding domestic property division. Focusing on the division of farmland within rural families, this paper shows that due to the increasing rights-asserting activities of rural individuals, the traditional norms regarding property rights between genders and generations were subject to contestation and negotiation. For instance, as increasing social mobility and economic opportunities caused more and more villagers to leave rural areas, disputes could break out among brothers over what constitutes a fair property division—one based on traditional egalitarianism among sons or one based on labor investment. Also, daughters, who traditionally did not have access to family property, began to demand their shares of land when the family divided. Parents’ attitudes towards daughters could also change, offering some daughters the opportunities of succeeding family property. Such new perceptions and behavior regarding property rights can serve as a benchmark/starting point for examining whether and how property relations in rural communities had become more fluid as extensive urbanization and increased rural-urban migration took place in China in the second decade of the new millennium.
Germ Cell Development in the Scleractinian Coral Euphyllia ancora (Cnidaria, Anthozoa)
Shinya Shikina, Chieh-Jhen Chen, Jhe-Yu Liou, Zi-Fan Shao, Yi-Jou Chung, Yan-Horn Lee, Ching-Fong Chang
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0041569
Abstract: Sexual reproduction of scleractinian coral is among the most important means of establishing coral populations. However, thus far, little is known about the mechanisms underlying coral gametogenesis. To better understand coral germ cell development, we performed a histological analysis of gametogenesis in Euphyllia ancora and characterized the coral homolog of the Drosophila germline marker gene vasa. The histological analysis revealed that E. ancora gametogenesis occurs in the mesenterial mesoglea between the mesenterial filaments and the retractor muscle bands. The development of germ cells takes approximately one year in females and half a year in males. Staining of tissue sections with an antibody against E. ancora Vasa (Eavas) revealed anti-Eavas immunoreactivity in the oogonia, early oocyte, and developing oocyte, but only faint or undetectable reactivity in developing oocytes that were >150 μm in diameters. In males, Eavas could be detected in the spermatogonia and primary spermatocytes but was only faintly detectable in the secondary spermatocytes, spermatids, and sperms. Furthermore, a reverse transcription-polymerase chain reaction analysis and Western blotting analysis of unfertilized mature eggs proved the presence of Eavas transcripts and proteins, suggesting that Eavas may be a maternal factor. Vasa may represent a germ cell marker for corals, and would allow us to distinguish germ cells from somatic cells in coral bodies that have no distinct organs.
Synthesis and Structure-Activity Relationships of Fenbufen Amide Analogs
Kun-I Lin,Chao-Hsun Yang,Chia-Wen Huang,Jhen-Yi Jian,Yu-Chun Huang,Chung-Shan Yu
Molecules , 2010, DOI: 10.3390/molecules15128796
Abstract: The previous discoveries of butyl fenbufen amide analogs with antitumor effects were further examined. The amide analogs with 1, 3, 4 and 8 carbons chains were prepared in 70-80% yield. Fenbufen had no cytotoxic effects at concentrations ranging from 10 to 100 μM. Methyl fenbufen amide had significant cytotoxic effects at a concentration of 100 μM. As the length of the alkyl amide side chain increased, the cytotoxic effects increased, and the octyl fenbufen amide had the greatest cytotoxic effect. After treatment with 30 μM octyl fenbufen amide, nearly seventy percent of the cells lost their viability. At the concentration of 10 μM, fenbufen amide analogs did not show cytotoxicity according to the MTT assay results. The NO scavenging activities of the fenbufen amide analogs were not significantly different from those of fenbufen.
Thermoelastic Problem of a Long Annular Multilayered Cylinder  [PDF]
Yi Hsien Wu, Kuo-Chang Jane
World Journal of Mechanics (WJM) , 2013, DOI: 10.4236/wjm.2013.35A002
Abstract:

Thermoelastic transient response of multilayered annular cylinders of infinite lengths subjected to known inner pressure and outer surfaces cooling are considered. A method based on the Laplace transformation and finite difference method has been developed to analyze the thermoelasticity problem. Using the Laplace transform with respect to time, the general solutions of the governing equations are obtained in transform domain. The solution is obtained by using the matrix similarity transformation and inverse Laplace transform. Solutions for the temperature and thermal stress distributions in a transient state were obtained. It was found that the temperature distribution, the displacement and the thermal stresses change slightly as time increases.

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