Probing the surface viscoelasticity of polymer films

Chen, Ming-Chou,Kim, Choongik 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.1

Glass transition temperature, one of the most important properties of amorphous polymers in many technological applications, exhibits deviation from bulk value for nanoconfined polymer thin films. Glass transition temperature deviation due to enhanced/ restricted polymer chain dynamics at the polymer surface or substrate interface has been probed by many different experimental techniques. In this paper, we describe recent experimental techniques which could probe the surface glass transition temperature of polymer thin films, their advantages and limitations, and organic thin-film transistor as a new tool to probe the surface viscoelasticity of polymer films.

A Novel Active Image AuthenticationSchemefor Block Truncation Coding

Chang-Ming Wu,Yu-Chen Hu,Kuo-Yu Liu,Jun-Chou Chuang 보안공학연구지원센터 2014 International Journal of Signal Processing, Image Vol.7 No.5

In this paper, a simple active image authentication scheme for the compressed images of block truncation coding (BTC) is proposed. In this scheme, the authentication codes of the compressed blocks are generated from the random value induced by the random seed. The authentication code of each compressed block is embedded into the bit map. The bit length of each authentication code can be chosen according to the user’s requirement. The experimental results indicate that the proposed scheme detects the tampered areas clearly and keeps good image qualities of the embedded images. Meanwhile, a low computational cost is required in the proposed scheme.

Effect of a vertical guide plate on the wind loading of an inclined flat plate

Kung-Ming Chung,Chin-Cheng Chou,Keh-Chin Chang,Yi-Jun Chen 한국풍공학회 2013 Wind and Structures, An International Journal (WAS Vol.17 No.5

Wind tunnel experiments were performed to study the wind loads on an inclined flat plate with and without a guide plate. Highly turbulent flow, which corresponded to free-stream turbulence intensity on the flat roof of low-rise buildings, was produced by a turbulence generation grid at the inlet of the test section. The test model could represent a typical solar collector panel of a solar water heater. There are up-stream movements of the separation bubble and side-edge vortices, more intense fluctuating pressure and a higher bending moment in the turbulent flow. A guide plate would result in higher lift coefficient, particularly with an increased projected area ratio of a guide plate to an inclined flat plate. The value of lift coefficient is considerably lower with increased free-stream turbulent intensity.

Quercetin-mediated Cell Cycle Arrest and Apoptosis Involving Activation of a Caspase Cascade through the Mitochondrial Pathway in Human Breast Cancer MCF-7 Cells

Chu-Chung Chou,Jai-Sing Yang,Hsu-Feng Lu,Siu-Wan Ip,Chyi Lo,Chih-Chung Wu,Jing-Pin Lin,Nou-Ying Tang,Jing-Gung Chung,Ming-Jen Chou,Ying-Hock Teng,Dar-Ren Chen 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.8

Dietary polyphenols have been correlated with a reduced risk of developing cancer. Quercetin (a natural polyphenolic compound) induced apoptosis in many human cancer cell lines, including breast cancer MCF-7 cells. However, the involvement of possible signaling pathways and the roles of quercetin in apoptosis are still undefined. The purpose of this study was to investigate the effects of quercetin on the induction of the apoptotic pathway in human breast cancer MCF-7 cells. When MCF-7 cells were treated with quercetin for 24 and 48 h and at various doses (10-175 μM), cell viability decreased significantly in time- and dose-dependent manners. Exposure of MCF-7 cells to 10-175 μM quercetin resulted in an approximate 90.25% decrease in viable cells. To explicate the mechanism underlying the antiproliferative effect of quercetin, cell cycle distribution and apoptosis in MCF-7 cells was investigated after exposure to 150 μM quercetin for 6-48 h. Quercetin caused a remarkable increase in the number of S phase (14.56%to 61.35%) and sub-G1 phase cells (0.1% to 8.32%) in a dose- and time-dependent manner. Quercetin caused S phase arrest by decreasing the protein expression of CDK2, cyclins A and B while increasing the p53 and p57 proteins. Following incubation with quercetin for 48 h, MCF-7 cells showed apoptotic cell death by the decreased levels of Bcl-2 protein and ΔΨ m and increased activations of caspase-6, -8 and -9. Moreover, quercetin increased the AIF protein released from mitochondria to nuclei and the GADD153 protein translocation from endoplasmic reticulum to the nuclei. These data suggested that quercetin may induce apoptosis by direct activation of the caspase cascade through the mitochondrial pathway in MCF-7 cells.

Polypoid Lesions of the Gallbladder: A Long-Term Follow-Up of 1204 Patients

( Shu-cheng Chou ),( Shin-e Wang ),( Shih-chin Chen ),( Yi-ming Shyr ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: Polypoid lesions of the gallbladder (PLG) are common, and most of them are benign. Few lesions are found malignant, but cannot be distinguished preoperatively by using common image modalities. Therefore, we compared characteristics of benign and malignant PLGs. Methods: We enrolled 1204 consecutive patients diagnosed with PLG at Taipei Veterans General Hospital during January 2004 to December 2013. Patients underwent either surgery or regular follow-up with various imaging modalities for at least 24 months. The mean follow-up duration was 72 ± 32 months. Results: Amoung our 1204 patients, 194 underwent surgical treatment and 1010 underwent regular follow-up. In addition, 73% patients were asymptomatic. The mean PLG size was 6.9 ± 7.7 (range, 0.8-129) mm; the PLGs of 337 patients (28%) grew during their follow-up periods. The majority of PLGs (90.4%) were single lesions, and 10.5% of patients had associated gallstones. The PLGs of 20.1% of surgical patients were malignant. Malignant PLGs were found in 32.4% of patients ≥50 years old and in 4.7% of those <50 years old (p < 0.001). Right quadrant abdominal pain, epigastric pain, and body weight loss were the three most common symptoms associated with malignancy. Malignant PLGs were significantly larger than benign lesions (means: 27.5 ± 18.4 mm vs. 12.3 ± 12.3 mm respectively, p < 0.001). Notably, the size of 5% of malignant PLGs was 3-5 mm, and that of 8% was 5-10 mm. The negative predictive value for gallbladder malignancy was 92.8% based on a size ≥10 mm and 100% based on a size ≥3 mm. Conclusions: Our study reassesses the PLG size that warrants more aggressive intervention. Cholecystectomy remains mandatory for PLGs >10 mm, but should also be considered a definitive diagnostic and treatment modality for PLGs with diameters of 3-10 mm.

Effect of a vertical guide plate on the wind loading of an inclined flat plate

Chung, Kung-Ming,Chou, Chin-Cheng,Chang, Keh-Chin,Chen, Yi-Jun Techno-Press 2013 Wind and Structures, An International Journal (WAS Vol.17 No.5

Wind tunnel experiments were performed to study the wind loads on an inclined flat plate with and without a guide plate. Highly turbulent flow, which corresponded to free-stream turbulence intensity on the flat roof of low-rise buildings, was produced by a turbulence generation grid at the inlet of the test section. The test model could represent a typical solar collector panel of a solar water heater. There are up-stream movements of the separation bubble and side-edge vortices, more intense fluctuating pressure and a higher bending moment in the turbulent flow. A guide plate would result in higher lift coefficient, particularly with an increased projected area ratio of a guide plate to an inclined flat plate. The value of lift coefficient is considerably lower with increased free-stream turbulent intensity.

Validation of a Palliative Prognostic Index to Predict Life Expectancy for Terminally Ill Cancer Patients in a Hospice Consultation Setting in Taiwan

Cheng, Wei-Hong,Kao, Chen-Yi,Hung, Yu-Shin,Su, Po-Jung,Hsieh, Chia-Hsun,Chen, Jen-Shi,Wang, Hung-Ming,Chou, Wen-Chi Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Background: The aim of our study was to assess the practical utility of the palliative prognostic index (PPI) as a prognostic tool used by nurse specialists in a hospice consultation setting in Taiwan. Methods: In total, 623 terminal cancer patients under hospice consultation care from one medical center in northern Taiwan were enrolled between January 1 and June 30, 2011. PPI was assessed by a nurse specialist at first hospice consultation and patients categorized into groups by prognosis (good, intermediate, poor). Patient survival was analyzed retrospectively to determine significance of between-group differences. Results: By PPI sum score, 37.2% of patients were in the good prognosis group, 18% in the intermediate prognosis group and 44.8% in the poor prognosis group. The death rates were 56%, 81.2% and 89.6% and median survivals were 76, 18 and 7 days, respectively. The hazard ratio was 0.19 (95% confidence interval [CI] 0.10-0.24, p<0.001) for the poor versus good prognosis group and 0.54 (95% CI 0.43-0.69, p<0.001) for the poor versus intermediate prognosis group. The sensitivity and specificity for the poor prognosis group was 66% and 71%; the positive predictive value and negative predictive value were 81% and 52%, respectively, to predict patient death within 21 days (area under the curve of the receiver operating characteristic was 0.68). Conclusions: Assessment by PPI can accurately predict survival of terminal cancer patients receiving hospice consultation care. PPI is a simple tool and can be administered by nurse members of hospice consultation teams.

Assessment of environmental effects in scour monitoring of a cable-stayed bridge simply based on pier vibration measurements

Wu, Wen-Hwa,Chen, Chien-Chou,Shi, Wei-Sheng,Huang, Chun-Ming Techno-Press 2017 Smart Structures and Systems, An International Jou Vol.20 No.2

A recent work by the authors has demonstrated the feasibility of scour evaluation for Kao-Ping-Hsi Cable-Stayed Bridge simply based on ambient vibration measurements. To further attain the goal of scour monitoring, a key challenge comes from the interference of several environmental factors that may also significantly alter the pier frequencies without the change of scour depth. Consequently, this study attempts to investigate the variation in certain modal frequencies of this bridge induced by several environmental factors. Four sets of pier vibration measurements were taken either during the season of plum rains, under regular summer days without rain, or in a period of typhoon. These signals are analyzed with the stochastic subspace identification and empirical mode decomposition techniques. The variations of the identified modal frequencies are then compared with those of the corresponding traffic load, air temperature, and water level. Comparison of the analyzed results elucidates that both the traffic load and the environmental temperature are negatively correlated with the bridge frequencies. However, the traffic load is clearly a more dominant factor to alternate the identified bridge deck frequency than the environmental temperature. The pier modes are also influenced by the passing traffic on the bridge deck, even though with a weaker correlation. In addition, the variation of air temperature follows a similar tendency as that of the passing traffic, but its effect on changing the bridge frequencies is obviously not as significant. As for the effect from the alternation of water level, it is observed that the frequency baselines of the pier modes may positively correlate with the water level during the seasons of plum rains and typhoon.

High-Performance Bottom-Contact Organic Thin-Film Transistors Based on Benzo[<i>d</i>,<i>d</i>′]thieno[3,2-<i>b</i>;4,5-<i>b</i>′]dithiophenes (BTDTs) Derivatives

Huang, Peng-Yi,Chen, Liang-Hsiang,Kim, Choongik,Chang, Hsiu-Chieh,Liang, You-jhih,Feng, Chieh-Yuan,Yeh, Chia-Ming,Ho, Jia-Chong,Lee, Cheng-Chung,Chen, Ming-Chou American Chemical Society 2012 ACS APPLIED MATERIALS & INTERFACES Vol.4 No.12

<P>Three benzo[<I>d</I>,<I>d</I>′]thieno[3,2-<I>b</I>;4,5-<I>b</I>′]dithiophene (<B>BTDT</B>) derivatives, end-functionalized with benzothiophenyl (<B>BT-BTDT</B>; <B>2</B>), benzothieno[3,2-b]thiophenyl (<B>BTT-BTDT</B>; 3), and benzo[<I>d</I>,<I>d</I>′]thieno[3,2-<I>b</I>;4,5-<I>b</I>′]dithiophenyl (<B>BBTDT</B>; <B>4</B>), were prepared for bottom-contact/bottom-gate organic thin-film transistors (OTFTs). An improved one-pot [2 + 1 + 1] synthetic method of <B>BTDT</B> with improved synthetic yield was achieved, which enabled the efficient realization of new <B>BTDT</B>-based semiconductors. All of the <B>BTDT</B> compounds exhibited high performance p-channel characteristics with carrier mobilities as high as 0.34 cm<SUP>2</SUP>/(V s) and a current on/off ratio of 1 × 10<SUP>7</SUP>, as well as enhanced ambient stability. The device characteristics have been correlated with the film morphologies and microstructures of the corresponding compounds.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2012/aamick.2012.4.issue-12/am3022448/production/images/medium/am-2012-022448_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am3022448'>ACS Electronic Supporting Info</A></P>

Electrochemical treatment for simultaneous removal of heavy metals and organics from surface finishing wastewater using sacrificial iron anode

Ya, Vinh,Martin, Natacha,Chou, Yi-Hsuan,Chen, Yi-Ming,Choo, Kwang-Ho,Chen, Shiao-Shing,Li, Chi-Wang Elsevier 2018 Journal of the Taiwan Institute of Chemical Engine Vol.83 No.-

<P><B>Abstract</B></P> <P>Surface finishing wastewater having low pH (∼2) and high conductivity (>11 mS/cm) was treated by electrocoagulation (EC) or electrochemical Fenton (ECF) processes using sacrificial iron anodes. Under the same theoretical Fe dosage, the effects of electrolytic time, initial pH, and current density on the simultaneous removal of organic and heavy metal were investigated. A complete metal removal was achieved even at the low current density of 24.2 mA/cm<SUP>2</SUP> and short electrolytic time of 4 min, whereas approximately 40% of chemical oxygen demand was removed. Increasing the electric current density did not improve removal efficiencies, but consumed more electric energy. Low current conditions produced a brown color sludge associated with ferric hydroxide. On the contrary, a greenish color sludge was created at a high current due to the formation of ferrous hydroxide. The formation of ferrous hydroxide impacted the treated water quality. The ECF was employed to overcome the low COD removal by the EC, achieving >67% of COD removal. The costs of ECF processes were slightly greater than that of chemical coagulation, but achieving a lot greater heavy metal removals. ECF process can be a promising method for simultaneous removal of heavy metal and organics from complex industrial wastewater.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Organics and metal removals by electrochemical treatments using Fe were studied. </LI> <LI> Fe(II)/Fe(III) distribution depended on current density, reaction time, and solution pH. </LI> <LI> The lower in electric current density, the better in energy efficiency. </LI> <LI> Electrochemical Fenton enhanced organic removal unachieved by electrocoagulation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>