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Li L, Xiang H, Zheng H, Chien YC, Duong NT, Gao J, Ang KW. Physical reservoirs based on MoS 2-HZO integrated ferroelectric field-effect transistors for reservoir computing systems. Nanoscale Horiz 2024; 9:752-763. [PMID: 38465422 DOI: 10.1039/d3nh00524k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Reservoir computing (RC), a variant of recurrent neural networks (RNNs), is well-known for its reduced energy consumption through exclusive focus on training the output weight and its superior performance in handling spatiotemporal information. Implementing these networks in hardware requires devices with superior fading memory behavior. Unlike filament-based two-terminal devices, those relying on ferroelectric switching demonstrate improved voltage reliability, while three-terminal transistors provide additional active control. HfO2-based ferroelectric materials such as Hf0.5Zr0.5O2 (HZO), have garnered attention for their scalability and seamless integration with CMOS technology. This study implements a RC hardware based on MoS2-HZO integrated device structure with enhanced spontaneous polarization field. By adjusting the oxygen vacancy concentration, the devices exhibit consistent responses to both identical and nonidentical voltages, making them suitable for diverse RC applications. The high accuracy of MNIST handwritten digits recognition highlights the rich reservoir states of the traditional RC architecture. Additionally, the impact of masks on RC implementation is assessed, showcasing the device's capability for spatiotemporal signal analysis. This development paves the way for implementing energy-efficient and high-performance computing solutions.
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Affiliation(s)
- Lingqi Li
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583.
| | - Heng Xiang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583.
| | - Haofei Zheng
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583.
| | - Yu-Chieh Chien
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583.
| | - Ngoc Thanh Duong
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583.
| | - Jing Gao
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583.
| | - Kah-Wee Ang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583.
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Duong NT, Shi Y, Li S, Chien YC, Xiang H, Zheng H, Li P, Li L, Wu Y, Ang KW. Coupled Ferroelectric-Photonic Memory in a Retinomorphic Hardware for In-Sensor Computing. Adv Sci (Weinh) 2024; 11:e2303447. [PMID: 38234245 DOI: 10.1002/advs.202303447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 09/14/2023] [Indexed: 01/19/2024]
Abstract
The development of all-in-one devices for artificial visual systems offers an attractive solution in terms of energy efficiency and real-time processing speed. In recent years, the proliferation of smart sensors in the growth of Internet-of-Things (IoT) has led to the increasing importance of in-sensor computing technology, which places computational power at the edge of the data-flow architecture. In this study, a prototype visual sensor inspired by the human retina is proposed, which integrates ferroelectricity and photosensitivity in two-dimensional (2D) α-In2Se3 material. This device mimics the functions of photoreceptors and amacrine cells in the retina, performing optical reception and memory computation functions through the use of electrical switching polarization in the channel. The gate-tunable linearity of excitatory and inhibitory functions in photon-induced short-term plasticity enables to encode and classify 12 000 images in the Mixed National Institute of Standards and Technology (MNIST) dataset with remarkable accuracy, achieving ≈94%. Additionally, in-sensor convolution image processing through a network of phototransistors, with five convolutional kernels electrically pre-programmed into the transistors is demonstrated. The convoluted photocurrent matrices undergo straightforward arithmetic calculations to produce edge and feature-enhanced scenarios. The findings demonstrate the potential of ferroelectric α-In2Se3 for highly compact and efficient retinomorphic hardware implementation, regardless of ambipolar transport in the channel.
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Affiliation(s)
- Ngoc Thanh Duong
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Yufei Shi
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Sifan Li
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Yu-Chieh Chien
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Heng Xiang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Haofei Zheng
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Peiyang Li
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Lingqi Li
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Yangwu Wu
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Kah-Wee Ang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
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Chien YC, Xiang H, Wang J, Shi Y, Fong X, Ang KW. Attack Resilient True Random Number Generators Using Ferroelectric-Enhanced Stochasticity in 2D Transistor. Small 2023; 19:e2302842. [PMID: 37194958 DOI: 10.1002/smll.202302842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/27/2023] [Indexed: 05/18/2023]
Abstract
By harnessing the physically unclonable properties, true random number generators (TRNGs) offer significant promises to alleviate security concerns by generating random bitstreams that are cryptographically secured. However, fundamental challenges remain as conventional hardware often requires complex circuitry design, showing a predictable pattern that is susceptible to machine learning attacks. Here, a low-power self-corrected TRNG is presented by exploiting the stochastic ferroelectric switching and charge trapping in molybdenum disulfide (MoS2 ) ferroelectric field-effect transistors (Fe-FET) based on hafnium oxide complex. The proposed TRNG exhibits enhanced stochastic variability with near-ideal entropy of ≈1.0, Hamming distance of ≈50%, independent autocorrelation function, and reliable endurance cycle against temperature variations. Furthermore, its unpredictable feature is systematically examined by machine learning attacks, namely the predictive regression model and the long-short-term-memory (LSTM) approach, where nondeterministic predictions can be concluded. Moreover, the generated cryptographic keys from the circuitry successfully pass the National Institute of Standards and Technology (NIST) 800-20 statistical test suite. The potential of integrating ferroelectric and 2D materials is highlighted for advanced data encryption, offering a novel alternative to generate truly random numbers.
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Affiliation(s)
- Yu-Chieh Chien
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Heng Xiang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Jianze Wang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Yufei Shi
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Xuanyao Fong
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Kah-Wee Ang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
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Chien YC, Xiang H, Shi Y, Duong NT, Li S, Ang KW. A MoS 2 Hafnium Oxide Based Ferroelectric Encoder for Temporal-Efficient Spiking Neural Network. Adv Mater 2023; 35:e2204949. [PMID: 36366910 DOI: 10.1002/adma.202204949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/26/2022] [Indexed: 06/16/2023]
Abstract
Spiking neural network (SNN), where the information is evaluated recurrently through spikes, has manifested significant promises to minimize the energy expenditure in data-intensive machine learning and artificial intelligence. Among these applications, the artificial neural encoders are essential to convert the external stimuli to a spiking format that can be subsequently fed to the neural network. Here, a molybdenum disulfide (MoS2 ) hafnium oxide-based ferroelectric encoder is demonstrated for temporal-efficient information processing in SNN. The fast domain switching attribute associated with the polycrystalline nature of hafnium oxide-based ferroelectric material is exploited for spike encoding, rendering it suitable for realizing biomimetic encoders. Accordingly, a high-performance ferroelectric encoder is achieved, featuring a superior switching efficiency, negligible charge trapping effect, and robust ferroelectric response, which successfully enable a broad dynamic range. Furthermore, an SNN is simulated to verify the precision of the encoded information, in which an average inference accuracy of 95.14% can be achieved, using the Modified National Insitute of Standards and Technology (MNIST) dataset for digit classification. Moreover, this ferroelectric encoder manifests prominent resilience against noise injection with an overall prediction accuracy of 94.73% under various Gaussian noise levels, showing practical promises to reduce the computational load for the neural network.
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Affiliation(s)
- Yu-Chieh Chien
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Heng Xiang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Yufei Shi
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Ngoc Thanh Duong
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Sifan Li
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Kah-Wee Ang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
- Institute of Materials Research and Engineering, A*STAR, 2 Fusionopolis Way, Singapore, 138634, Singapore
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Pam ME, Li S, Su T, Chien YC, Li Y, Ang YS, Ang KW. Interface-Modulated Resistive Switching in Mo-Irradiated ReS 2 for Neuromorphic Computing. Adv Mater 2022; 34:e2202722. [PMID: 35610176 DOI: 10.1002/adma.202202722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/30/2022] [Indexed: 06/15/2023]
Abstract
Coupling charge impurity scattering effects and charge-carrier modulation by doping can offer intriguing opportunities for atomic-level control of resistive switching (RS). Nonetheless, such effects have remained unexplored for memristive applications based on 2D materials. Here a facile approach is reported to transform an RS-inactive rhenium disulfide (ReS2 ) into an effective switching material through interfacial modulation induced by molybdenum-irradiation (Mo-i) doping. Using ReS2 as a model system, this study unveils a unique RS mechanism based on the formation/dissolution of metallic β-ReO2 filament across the defective ReS2 interface during the set/reset process. Through simple interfacial modulation, ReS2 of various thicknesses are switchable by modulating the Mo-irradiation period. Besides, the Mo-irradiated ReS2 (Mo-ReS2 ) memristor further exhibits a bipolar non-volatile switching ratio of nearly two orders of magnitude, programmable multilevel resistance states, and long-term synaptic plasticity. Additionally, the fabricated device can achieve a high MNIST learning accuracy of 91% under a non-identical pulse train. The study's findings demonstrate the potential for modulating RS in RS-inactive 2D materials via the unique doping-induced charged impurity scattering property.
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Affiliation(s)
- Mei Er Pam
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Sifan Li
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Tong Su
- Science, Mathematics and Technology (SMT), Singapore University of Technology and Design (SUTD), 8 Somapah Road, Singapore, 487372, Singapore
| | - Yu-Chieh Chien
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Yesheng Li
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Yee Sin Ang
- Science, Mathematics and Technology (SMT), Singapore University of Technology and Design (SUTD), 8 Somapah Road, Singapore, 487372, Singapore
| | - Kah-Wee Ang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
- Institute of Materials Research and Engineering, A*STAR, 2 Fusionopolis, Singapore, 138634, Singapore
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Li S, Pam ME, Li Y, Chen L, Chien YC, Fong X, Chi D, Ang KW. Wafer-Scale 2D Hafnium Diselenide Based Memristor Crossbar Array for Energy-Efficient Neural Network Hardware. Adv Mater 2022; 34:e2103376. [PMID: 34510567 DOI: 10.1002/adma.202103376] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/28/2021] [Indexed: 06/13/2023]
Abstract
Memristor crossbar with programmable conductance could overcome the energy consumption and speed limitations of neural networks when executing core computing tasks in image processing. However, the implementation of crossbar array (CBA) based on ultrathin 2D materials is hindered by challenges associated with large-scale material synthesis and device integration. Here, a memristor CBA is demonstrated using wafer-scale (2-inch) polycrystalline hafnium diselenide (HfSe2 ) grown by molecular beam epitaxy, and a metal-assisted van der Waals transfer technique. The memristor exhibits small switching voltage (0.6 V), low switching energy (0.82 pJ), and simultaneously achieves emulation of synaptic weight plasticity. Furthermore, the CBA enables artificial neural network with a high recognition accuracy of 93.34%. Hardware multiply-and-accumulate (MAC) operation with a narrow error distribution of 0.29% is also demonstrated, and a high power efficiency of greater than 8-trillion operations per second per Watt is achieved. Based on the MAC results, hardware convolution image processing can be performed using programmable kernels (i.e., soft, horizontal, and vertical edge enhancement), which constitutes a vital function for neural network hardware.
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Affiliation(s)
- Sifan Li
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Mei-Er Pam
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Yesheng Li
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Li Chen
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Yu-Chieh Chien
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Xuanyao Fong
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Dongzhi Chi
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Kah-Wee Ang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Singapore, 138634, Singapore
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Duan N, Li Y, Chiang HC, Chen J, Pan WQ, Zhou YX, Chien YC, He YH, Xue KH, Liu G, Chang TC, Miao XS. An electro-photo-sensitive synaptic transistor for edge neuromorphic visual systems. Nanoscale 2019; 11:17590-17599. [PMID: 31461106 DOI: 10.1039/c9nr04195h] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The practical application of optoelectronic artificial synapses in neuromorphic visual systems is still hindered by their limited functionality, reliability and the challenge of mass production. Here, an electro-photo-sensitive synapse based on a highly reliable amorphous InGaZnO thin-film transistor is demonstrated. Not only does the synapse respond to electrical voltage spikes due to charge trapping/detrapping, but also the weight is modified directly by persistent photocurrent effects under UV-light stimulation. Representative forms of synaptic plasticity, including inhibitory and excitatory postsynaptic currents, frequency-dependent characteristics, short-term to long-term plasticity transitions, and summation effects, are successfully demonstrated. In particular, optoelectronic synergetic modulation leads to reconfigurable excitatory and inhibitory synaptic behaviors, which provides a promising way to achieve the homeostatic regulation of synaptic weights. Moreover, the analogue channel conductance with 100 states is used as the weight update rule to perform MNIST handwritten digit recognition, using system-level LeNet-5 convolutional neural network simulations. The network shows a high recognition accuracy of 95.99% and good tolerance to noisy input patterns. This study highlights the commercial potential of mature optoelectronic InGaZnO transistor technology in edge neuromorphic systems.
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Affiliation(s)
- Nian Duan
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.
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Lin YM, Sun HY, Chiu WT, Su HC, Chien YC, Chong LW, Chang HC, Bai CH, Young KC, Tsao CW. Calcitriol Inhibits HCV Infection via Blockade of Activation of PPAR and Interference with Endoplasmic Reticulum-Associated Degradation. Viruses 2018; 10:v10020057. [PMID: 29385741 PMCID: PMC5850364 DOI: 10.3390/v10020057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 01/17/2018] [Accepted: 01/26/2018] [Indexed: 02/06/2023] Open
Abstract
Vitamin D has been identified as an innate anti-hepatitis C virus (HCV) agent but the possible mechanisms for this issue remain unclear. Here, we clarified the mechanisms of calcitriol-mediated inhibition of HCV infection. Calcitriol partially inhibited HCV infection, nitric oxide (NO) release and lipid accumulation in Huh7.5 human hepatoma cells via the activation of vitamin D receptor (VDR). When cells were pretreated with the activators of peroxisome proliferator-activated receptor (PPAR)-α (Wy14643) and -γ (Ly171883), the calcitriol-mediated HCV suppression was reversed. Otherwise, three individual stimulators of PPAR-α/β/γ blocked the activation of VDR. PPAR-β (linoleic acid) reversed the inhibition of NO release, whereas PPAR-γ (Ly171883) reversed the inhibitions of NO release and lipid accumulation in the presence of calcitriol. The calcitriol-mediated viral suppression, inhibition of NO release and activation of VDR were partially blocked by an inhibitor of endoplasmic reticulum-associated degradation (ERAD), kifunensine. Furthermore, calcitriol blocked the HCV-induced expressions of apolipoprotein J and 78 kDa glucose-regulated protein, which was restored by pretreatment of kifunensine. These results indicated that the calcitriol-mediated HCV suppression was associated with the activation of VDR, interference with ERAD process, as well as blockades of PPAR, lipid accumulation and nitrative stress.
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Affiliation(s)
- Yu-Min Lin
- Department of Gastroenterology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 11101, Taiwan.
| | - Hung-Yu Sun
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
| | - Wen-Tai Chiu
- Department of Biomedical Engineering, College of Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
| | - Hui-Chen Su
- Department of Pharmacy, Chi-Mei Medical Center, Tainan 71004, Taiwan.
| | - Yu-Chieh Chien
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
- Department of Long Term Care, Chung Hwa University of Medical Technology, Tainan 71703, Taiwan.
| | - Lee-Won Chong
- Department of Gastroenterology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 11101, Taiwan.
| | - Hung-Chuen Chang
- Department of Gastroenterology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 11101, Taiwan.
| | - Chyi-Huey Bai
- Department of Public Health, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
| | - Kung-Chia Young
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
| | - Chiung-Wen Tsao
- Department of Long Term Care, Chung Hwa University of Medical Technology, Tainan 71703, Taiwan.
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Abstract
Carbon monoxide (CO) results from the incomplete oxidation of hydrocarbon fuels. While CO can be desirable in some syngas processes, it is a dangerous emission from fires, gas heaters, gas stoves, or furnaces where insufficient oxygen in the core reaction prevents complete oxidation of fuel to carbon dioxide and water, particularly when the reaction is interrupted by interaction with relatively cool solid boundaries. This research examines the physico-thermo-chemical processes responsible for carbon monoxide release from a small laminar non-premixed methane/air flame impinging on a nearby surface. We measure the changes in CO emission as correlated with variations in flame structure observed using planar laser induced fluorescence (PLIF of OH and 2-photon CO), and two-line OH PLIF thermometry, as a function of burner-to-plate distance. In particular, this work combines the use of OH and CO PLIF, and PLIF thermometry to describe the relative locations of the CO rich region, the peak heat release zone as indicated by chemiluminescence and OH gradients, and the extended oxidative zone in the impinging flames. The results show that CO release correlates strongly with stagnating flow-driven changes in the location and extent of high concentration regions of OH in surface-impinging diffusion flames.
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Affiliation(s)
- Y C Chien
- Mechanical and Aerospace Engineering, University of California Irvine, Irvine, 92697. USA
| | - D Escofet-Martin
- Mechanical and Aerospace Engineering, University of California Irvine, Irvine, 92697. USA
| | - D Dunn-Rankin
- Mechanical and Aerospace Engineering, University of California Irvine, Irvine, 92697. USA
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Lin YM, Yu BC, Chiu WT, Sun HY, Chien YC, Su HC, Yen SY, Lai HW, Bai CH, Young KC, Tsao CW. Fluoxetine regulates cell growth inhibition of interferon-α. Int J Oncol 2016; 49:1746-54. [DOI: 10.3892/ijo.2016.3650] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 07/25/2016] [Indexed: 11/05/2022] Open
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Lin CF, Young KC, Bai CH, Yu BC, Ma CT, Chien YC, Su HC, Wang HY, Liao CS, Lai HW, Tsao CW. Blockade of reactive oxygen species and Akt activation is critical for anti-inflammation and growth inhibition of metformin in phosphatase and tensin homolog-deficient RAW264.7 cells. Immunopharmacol Immunotoxicol 2013; 35:669-77. [PMID: 24053326 DOI: 10.3109/08923973.2013.837059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
CONTEXT Metformin is widely used for treatment of type 2 diabetes and has a potential application on the treatment of inflammation and cancer. Phosphatase and tensin homolog (PTEN) plays a critical role in cancer cell growth and inflammation; however, precise mechanisms remain unclear. OBJECTIVE We aimed to investigate the possible mechanisms of how PTEN regulates metformin against cell growth and inflammation. MATERIALS AND METHODS We established PTEN knockdown in RAW264.7 murine macrophages (shPTEN cells) to detect inflammatory mediators using commercial kits, production of reactive oxygen species (ROS) by flow cytometry, cell growth by MTT assay and phosphorylated levels of signal molecules by western blot. RESULTS The shPTEN cells had a significant large amount of inflammatory mediators, such as inducible nitric oxide synthase (iNOS)/nitric oxide (NO) and cyclooxygenase-2 (COX-2)/prostaglandin E(2) (PGE(2)); and also elevated the production of ROS and increased cell proliferation. These effects were accompanied with the activation of Akt and p38 mitogen-activated protein kinase (MAPK), and the inactivation of an AMP-activated protein kinase (AMPK) activator and extracellular signal-regulated kinase 1/2. Pretreatment with metformin not only blocked these inflammatory mediators, but also caused growth inhibition induced by significant apoptosis. Furthermore, inactivation of Akt, blockade of ROS generation and independence of activations of AMPK and MAPK by metformin were also observed. CONCLUSION Macrophages with PTEN deficiency developed a continuous inflammatory microenvironment, which further aggravated tumor cell growth. Moreover, metformin affected PTEN-deficient cells dependent of inhibition of ROS production and Akt activation against enlarged inflammatory mediators and/or cell growth in shPTEN cells.
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12
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Chien YC, Yang SH. Investigation of the combustion kinetics and polycyclic aromatic hydrocarbon emissions from polycaprolactone combustion. Environ Technol 2013; 34:149-155. [PMID: 23530325 DOI: 10.1080/09593330.2012.689360] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Polycaprolactone (PCL) is one of the most attractive biodegradable plastics that has been widely used in medicine and agriculture fields. Because of the large increase in biodegradable plastics usage, the production of waste biodegradable plastics will be increasing dramatically, producing a growing environmental problem. Generally, waste PCL is collected along with municipal solid wastes and then incinerated. This study investigates the combustion kinetics and emission factors of 16 US Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) in the PCL combustion. Experimentally, two reactions are involved in the PCL combustion process, possibly resulting in the emission of carbon dioxide, propanal, protonated caprolactone and very small amounts of PAH produced by incomplete combustion. The intermediate products may continuously be oxidized to form CO2. The emission factors for 16 US EPA priority PAHs are n.d. -2.95 microg/g, which are much lower than those of poly lactic acid and other plastics combustion. The conversion of PCL is 100%. Results from this work suggest that combustion is a good choice for the waste PCL disposal.
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Affiliation(s)
- Y C Chien
- Department of Environmental Engineering and Science, Fooyin University, Kaohsiung City, Taiwan, Republic of China.
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13
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Chien YC, Lin CH, Chiang MY, Chang HS, Liao CH, Chen IS, Peng CF, Tsai IL. Secondary metabolites from the root of Ehretia longiflora and their biological activities. Phytochemistry 2012; 80:50-57. [PMID: 22626966 DOI: 10.1016/j.phytochem.2012.04.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 02/29/2012] [Accepted: 04/24/2012] [Indexed: 06/01/2023]
Abstract
Bioassay-guided fractionation of the methanolic extract of the root of Ehretia longiflora (Boraginaceae) afforded eight compounds, ehretiquinone (1), ehretiolide (2), ehreticoumarin (3), ehretilactone A (4), ehretilactone B (5), ehretiamide (6), ehretine (7), and ehretiate (8), together with 12 known compounds (9-20). The relative configuration of 1 was determined by single crystal X-ray diffraction. Among the isolates, 1 and prenylhydroquinone (14) showed antitubercular activity against Mycobacterium tuberculosis strain H37Rv with MIC values of 25.0 and 26.2 μg/mL, respectively. Moreover, 1 exhibited inhibitory effects on N-formylmethionylleucylphenylalanine (fMLP)-induced superoxide production, with IC₅₀ value of 0.36±0.03μM.
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Affiliation(s)
- Yu-Chieh Chien
- Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan, ROC
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14
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Su HC, Ma CT, Yu BC, Chien YC, Tsai CC, Huang WC, Lin CF, Chuang YH, Young KC, Wang JN, Tsao CW. Glycogen synthase kinase-3β regulates anti-inflammatory property of fluoxetine. Int Immunopharmacol 2012; 14:150-6. [PMID: 22749848 DOI: 10.1016/j.intimp.2012.06.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/24/2012] [Accepted: 06/19/2012] [Indexed: 11/16/2022]
Abstract
A selective serotonin reuptake inhibitor fluoxetine not only is widely used in the treatment of depression but also has an anti-inflammatory property. Glycogen synthase kinase-3beta (GSK-3β) is a vital factor in the inflammation process. How fluoxetine interferes with inflammation via a GSK-3β-dependent pathway remains unclear. The aim of this study is to investigate the effects of fluoxetine on lipopolysaccharide (LPS)-induced inflammation. Results showed that fluoxetine decreased mortality rate of the mice. It also inhibited LPS-induced release of nitric oxide (NO) and prostaglandin E2 (PGE2) in serum and RAW264.7 murine macrophages and expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Upon LPS stimulation, fluoxetine caused a delay but increased in the phosphorylated levels of GSK-3β (ser9), whereas it did not affect LPS-induced activation of mitogen-activated protein kinase (MAPK) and generation of reactive oxygen species (ROS). Fluoxetine in combination with phosphatidylinositol 3-kinases/Akt inhibitors (LY294002 and Wortmannin) did not have a synergistic inhibition on LPS-induced NO release and PGE2 production. In addition, peroxisome proliferator-activated receptor γ (PPARγ) antagonist GW9622 showed no reverse effects of this inhibition of fluoxetine. GSK-3β knockdown blocked the inhibitory effects of fluoxetine on LPS-induced iNOS/NO release and COX-2/PGE2 production. These results indicated that GSK-3β regulated anti-inflammatory property of fluoxetine. However, Akt activation, ROS generation, and altered PPARγ activity were not involved in this inhibition of fluoxetine.
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Affiliation(s)
- Hui-Chen Su
- Department of Pharmacy, Chi-Mei Medical Center, Tainan, Taiwan
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15
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Chien YC, Wu SC, Wu JT. Identification of physical parameters controlling the dominance of algal species in a subtropical reservoir. Water Sci Technol 2009; 60:1779-1786. [PMID: 19809140 DOI: 10.2166/wst.2009.541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Eutrophication is a serious problem of water resource management in Taiwan. The occurrence of annoying algal species as well as abnormally abundant algal mass threatens the quality of water supply. The growth and decline of a specific phytoplankton species are affected by environmental factors, including light, nutrients, temperature, etc. There have been many investigations on the effects of individual factors on the abundance and composition of algal populations. However, many analyses on the effects of environmental factors, especially the concentration of nutrients, on phytoplankton failed to identify the controlling factors on the dynamic change of the phytoplankton species. This study used statistical methods to isolate the effect of seasons on the phytoplankton growth and searched for the relationships between the nutrient concentrations and the abundance of different algal species in Feitsui Reservoir based on the data obtained from 1995 to 2003. We found that the dynamic change of dominance of some species of phytoplankton was strongly related to the seasonal factors. The controlling factors of the survival of an algal species were the settling and mobility of the phytoplankton, the mixing depth and the vertical mixing strength of the water bodies. According to our preliminary findings, the influence of physical factors, varying seasonally, outweighs the influence of nutrients on the algal species composition in Feitsui Reservoir in Taiwan.
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Affiliation(s)
- Y C Chien
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-shan Road, Taipei 10673, Taiwan, ROC.
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16
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Abstract
BACKGROUND It is probable but unproven that Epstein-Barr virus (EBV) has a role in nasopharyngeal carcinoma. We determined whether antibodies against EBV are present before the development of nasopharyngeal carcinoma. METHODS A total of 9699 men were enrolled between 1984 and 1986. Blood samples were examined for IgA antibodies against EBV capsid antigen and neutralizing antibodies against EBV-specific DNase. During 131,981 person-years of follow-up, 22 pathologically confirmed new cases of nasopharyngeal carcinoma that were diagnosed more than one year after recruitment were ascertained through linkage with the National Cancer Registry of Taiwan. RESULTS The cumulative risk of nasopharyngeal carcinoma per 100,000 person-years was 11.2 for subjects who tested positive for neither serologic marker, 45.0 for those who had one marker, and 371.0 for those who had both markers. After adjustment for age and the presence or absence of a family history of nasopharyngeal carcinoma, the relative risk of nasopharyngeal carcinoma was 32.8 for subjects with both markers (95 percent confidence interval, 7.3 to 147.2; P<0.001) and 4.0 for subjects with one marker (95 percent confidence interval, 1.6 to 10.2; P=0.003), as compared with subjects with neither marker. The longer the duration of follow-up, the greater the difference in the cumulative incidence of nasopharyngeal carcinoma between seropositive and seronegative subjects. CONCLUSIONS IgA antibodies against EBV capsid antigen and neutralizing antibodies against EBV DNase are predictive of nasopharyngeal carcinoma.
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Affiliation(s)
- Y C Chien
- Graduate Institute of Epidemiology, College of Public Health, National Taiwan University, Taipei, Taiwan
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17
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Abstract
Experimentally, CCl4 was effectively mineralized by CuO to yield stable inorganic species of CO2 and CuCl2 (CCl4 + 2CuO --> 2CuCl2 + CO2). High CCl4 conversions (63-83%) were found in the mineralization process performed at 513-603 K for 10-30 min. Using X-ray-absorption near edge structure (XANES) and X-ray photoelectron spectroscopies, we found that most CuCl2 was encapsulated in the CCl4-mineralized product solid (mineralization at 513 K for 30 min). At higher mineralization temperatures (563-603 K), CuCl2 was found to be predominant on the surfaces of the mineralization product. Speciation of copper in the mineralization product solid was also studied by extended X-ray absorption fine structure (EXAFS) spectroscopy. Bond distances of Cu-O and Cu-Cl in the CCl4-mineralized product solid were 1.93-1.94 and 2.10-2.12 , respectively, which were greater than those of normal CuO and CuCl2 by 0.03-0.07 A. The increase of the bond distances for Cu-O and Cu-Cl might be due to Cl insertion and concomitant structural perturbation of unreacted CuO in the mineralization process. Forthe second shell around copper atom, bond distances of Cu-(O)-Cu also increased by 0.03-0.05 A, and the coordination numbers of Cu-O and Cu-(O)-Cu decreased, as expected, in the mineralization process. In addition, stoichiometrically excess oxygen atoms were found on the solid surfaces, and they might play an important role in the mineralization of CCl4, leading to the formation of CO2 and Cl. Chloride atoms might be further captured by CuO, yielding CuCl2 in the mineralization process. This work exemplifies the utilization of X-ray spectroscopies (XANES, EXAFS, and XPS) to reveal the speciation and possible reaction pathway in a very complex mineralization process in detail.
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Affiliation(s)
- Y C Chien
- Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan
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18
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Abstract
In the past 3 decades, research has proven the significance of competitive adsorption in the equilibrium of pollutants between solid and liquid phases. However, studies on the competitive adsorption of complex ions are very limited in spite of its important role in transporting pollutants in the natural environment. The objective of this study is to derive the thermodynamic parameters of the competitive adsorption between ferricyanide and ferrocyanide from the modified Langmuir isotherm and the triple-layer model (TLM) to determine the location of adsorption. The effects of pH, temperature, and ion concentration on competitive adsorption onto gamma-Al(2)O(3) were investigated. The results demonstrate that ferrocyanide is more competitive than ferricyanide. By comparing the derived K(app) with K(int), we inferred that the adsorption of ferricyanide and ferrocyanide onto gamma-Al(2)O(3) was achieved through outer-sphere complexation. The negative DeltaH degrees indicated that the adsorption was exothermic. The positive entropy (Delta S degrees ) was caused by the replacement and release of a greater number of smaller surface ions by adsorbed ferricyanide and ferrocyanide ions of larger size. Copyright 2000 Academic Press.
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Affiliation(s)
- WP Cheng
- Department of Safety, Health and Environmental Engineering, National Lien-Ho Institute of Technology, Miaoli, Taiwan, 36012, Republic of China
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Abstract
A rapid and complete destruction of organics in the supercritical water oxidation (SCWO) of the Co-exchanged resin was found experimentally. Due to an extremely low solubility of CoSO4 salt formed and separated effectively in the SCWO process, a minimal release of the nuclide Co would be warranted. In addition, recycling of Co nuclides is also possible by decomposition of the CoSO4 species at elevated temperatures (> 1040 K).
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Affiliation(s)
- Y J Huang
- Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan
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20
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Abstract
Behavior of Br in pyrolysis of the printed circuit board waste with valuable copper and oil recycling has been studied in the present work. Experimentally, pyrolysis of the printed circuit board waste generated approximately 40.6% of oils, 24.9% of noncondensible gases and 34.5% of solid residues that enriched in copper (90-95%). The cuts of the oils produced from pyrolysis of the printed circuit board waste into weighted boiling fraction were primarily light naphtha and heavy gas oil. Approximately 72.3% of total Br in the printed circuit board waste were found in product gas mainly as HBr and bromobenzene. However, by extended X-ray absorption fine structural (EXAFS) spectroscopy, Cu-O and Cu-(O)-Cu species with bond distance of 1.87 and 2.95 A, respectively, were observed in the solid residues. Essentially, no Cu-Br species was found.
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Affiliation(s)
- Y C Chien
- Department of Environmental Engineering, Cheng Kung University, Tainan, Taiwan, ROC
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Hung HC, Chuang J, Chien YC, Chern HD, Chiang CP, Kuo YS, Hildesheim A, Chen CJ. Genetic polymorphisms of CYP2E1, GSTM1, and GSTT1; environmental factors and risk of oral cancer. Cancer Epidemiol Biomarkers Prev 1997; 6:901-5. [PMID: 9367063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Both genetic and environmental factors are involved in the development of cancer; some phase I and II enzymes involved in the metabolism of carcinogens are polymorphic in genotypes. This case-control study focused on the interactions between oral cancer risk factors and genetic polymorphisms of cytochrome P-450 (CYP) 2E1 and glutathione S-transferase (GST) M1 and GSTT1. A total of 41 male oral cancer cases was recruited from National Taiwan University Hospital, and 123 healthy controls frequency-matched on ethnicity, sex, and age were recruited from residents living in Taipei City and Taipei County. History of cigarette smoking, alcohol drinking, and betel quid chewing was obtained through a standardized questionnaire interview, and genotypes of CYP2E1, GSTM1, and GSTT1 were determined by PCR. Cigarette smoking, alcohol drinking, and betel quid chewing were significantly associated with the risk of oral cancer in a dose-response relationship. All betel quid chewers smoked cigarettes in both the case and control groups. In the multiple logistic regression analysis, those who had null genotypes of GSTM1 and/or GSTT1 had an increased oral cancer risk compared with those who had non-null genotypes of both GSTM1 and GSTT1, showing a multivariate-adjusted odds ratio (OR) of 4.6 with a 95% confidence interval (CI) of 0.9-23.7 (P = 0.08). The CYP2E1 c1/c2 and c2/c2 genotypes were associated with a significantly increased oral cancer risk compared with the c1/c1 genotype among those who did not chew betel quid (OR, 4.7; 95% CI, 1.1-20.2), but not among betel quid chewers. Habitual alcohol drinking was associated with a significantly increased oral cancer risk, showing an OR of 3.0 (95% CI, 1.1-8.8). These results implied that there are gene-gene and gene-environment interactions in the development of oral cancer.
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Affiliation(s)
- H C Hung
- Graduate Institute of Public Health, College of Public Health, National Taiwan University, Taipei, Republic of China
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Abstract
92 young adolescents were tested using Tversky and Kahneman's (1981) decision problems for framing effects. A notable number of young adolescents tested were not influenced by the context of the decision problems, thus they selected the same response option for positively and negatively framed problems. Parallel information was not available in Tversky and Kahneman's study for adults because they used a between-subjects design. However, for present adolescents who selected different response options for different framing problems, the response pattern exhibited by them resembled the general pattern exhibited by the adults tested in Tversky and Kahneman's study-negative frames led them to accept risk to avoid certain loss; positive frames prevented them from risking what they were certain to gain. Boys and girls were similar in their susceptibility to framing effects as were honors students in mathematics as compared to nonhonors students. Although the positive vs negative framing only influenced some of the young adolescents tested in this study, because the influence was consistent, researchers and educators interested in adolescents' decisions involving risky choices might use framing principles to design and assess cognitive interventions for high-risk behaviors among young adolescents.
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Affiliation(s)
- Y C Chien
- Department of Psychology, California State University, San Bernardino 92407, USA
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Abstract
Urinary mercury levels and excretion rates were measured to determine the effect of dental amalgam restoration on the mercury body burden. No consistent increase in urinary mercury concentrations was found among subjects who had a single restoration, but a continuously increasing statistically significant (P < 0.05) trend, that was 33% above background levels, was detected between 9 and 12 days after restoration, in the subject with four restorations in a single day. The current findings suggested that even though amalgam restorations can cause an increase in mercury body burden, the elevation above background levels is small and thus the risks associated with the use of this material are considered minimal for the general population.
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Affiliation(s)
- Y C Chien
- Department of Environmental Sciences, Rutgers University, Piscataway, NJ, USA
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Affiliation(s)
- Y Grodzinsky
- Department of Psychology, Tel Aviv University, Israel
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Liaw KY, Chien YC. Management of thyroid cancers diagnosed histologically after surgery. J Formos Med Assoc 1993; 92:312-6. [PMID: 8104578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Thirty-three patients with thyroid cancer diagnosed histologically after surgery from 1960 to 1987 were reviewed to delineate an acceptable treatment policy. The first group of 17 patients did not undergo a second operation, and five of these patients (29%) experienced local recurrence, metastasis and death during follow-up (minimum of 15 years). A second group of 16 patients underwent a second operation, and all remained healthy during the mean follow-up period of eight years. In 56% of the specimens obtained during the second operation, a histologic examination revealed residual cancerous foci in the remnant thyroid tissue or lymph node. This present study indicates that age, tumor grade, extent and size (AGES score), and the operative strategy used in the initial procedure are important factors affecting the prognosis. We suggest that patients whose tumors lose capsular integrity, show evidence of intraglandular metastases or have an AGES score of 3.1 or more should be considered as candidates for a second operation.
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Affiliation(s)
- K Y Liaw
- Department of Surgery, National Taiwan University Hospital, Taipei, R.O.C
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Chien YC, Kao KN, Wetter LR. Chromosomal and isozyme studies of Nicotiana tabacum - Glycine max hybrid cell lines. Theor Appl Genet 1982; 62:301-304. [PMID: 24270647 DOI: 10.1007/bf00275089] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/1982] [Indexed: 06/02/2023]
Abstract
The chromosomal stability of a number of somatic hybrids derived from soybean (Glycine max (L.) Merr.) and Nicotiana tabacum var. 'Xanthi' were investigated. Several of the hybrid cell lines retained more than half the complement of N. tabacum chromosomes after 7 months of culturing. A number of chromosomal abnormalities were observed. The hybrids were positively identified by employing isozyme analysis of several dehydrogenases and aspartate aminotransferase.
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Affiliation(s)
- Y C Chien
- Prairie Regional Laboratory, National Research Council of Canada, Saskatoon, Saskatchewan, Canada
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Chien YC, Wise GJ, Grob D, Stein P. Magnetically induced detrusor contraction. A new concept for treatment of neurogenic bladder. Invest Urol 1973; 10:464-8. [PMID: 4704173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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