84 results on '"Yu-chung Chang"'
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2. Protein-based nanomaterials and nanosystems for biomedical applications: A review
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Shichao Ding, Wenlei Zhu, Yuehe Lin, Xiaoling Hu, Nan Zhang, Dan Du, Yu-Chung Chang, and Zhaoyuan Lyu
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Engineering ,business.industry ,Mechanical Engineering ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Mechanics of Materials ,General Materials Science ,0210 nano-technology ,business - Abstract
Advanced protein-based nanomaterials and nanosystems (PNNS) have attracted considerable scientific interest in recent decades due to their potential in bio-applications. Nowadays, the constructed PNNS exhibit different properties for various special applications based on the characteristics of different proteins. Herein, in this review article, a systematic summary and discussion focusing on designing multi-functional PNNS are presented. The latest developments in unique synthesis strategies and detailed classification of PNNS are reviewed. The functions of proteins in PNNS for biomedical applications, such as targeting proteins, carriers, enzymes, and fluorescent indicators, are summarized. Finally, the challenges and forward-looking perspectives of PNNS research are provided.
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- 2021
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3. Precision Marketing Strategies for Small and Medium-sized Clothing E-commerce Enterprises Based on Big Data
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Yu-Chung Chang
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Commerce ,Precision marketing ,business.industry ,Big data ,E-commerce ,business ,Clothing - Abstract
Based on the big data analysis technology of small and medium-sized clothing e-commerce enterprises, this paper provides theoretical and practical methods for e-commerce enterprises to apply big data technology. The data sources come from questionnaires and online data grab. Through the Google online questionnaire survey, 252 valid questionnaires were received. Python is used to search valid reviews on Tmall and Internet with some keywords, and a total of 11,864 valid comments were obtained. We find that the reason why men buy clothes is as high as 68% because of the seasonal change, but only 31% of women buy clothes because of the seasonal change. The higher the average monthly income of women, the more attention is paid to whether the style of clothing design is suitable for themselves, and the more attention is paid to the service attitude of e-commerce enterprises. From decision tree analysis, the fit of clothing style is the most important factor affecting the shopping choice of customers. From the data of customer reviews, the most mentioned variables are clothing style, fashion, service attitude and price. The number of reviews and the sentiment analysis score on clothing style are all ranking first. The number of reviews and the sentiment analysis score on clothing fashion are all ranking second. We also proposes corresponding precision marketing strategies based on the results of big data analysis, such as gender recommendation strategies, personalized recommendation strategies, differentiated marketing strategies, enterprise training and clothing design strategies.
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- 2020
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4. Smart polymers and nanocomposites for 3D and 4D printing
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Zhaoyuan Lyu, Yu-Chung Chang, Shahriar Safaee, Roland K. Chen, Mojtaba Falahati, Parvaneh Ahmadvand, Lei Li, and Yuehe Lin
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Smart system ,Fabrication ,business.industry ,Computer science ,Mechanical Engineering ,3D printing ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Smart material ,01 natural sciences ,Smart polymer ,0104 chemical sciences ,Mechanics of Materials ,Robot ,General Materials Science ,Artificial muscle ,0210 nano-technology ,Actuator ,business - Abstract
Smart materials, also known as intelligent materials, which are responsive to the external stimuli including heat, moisture, stress, pH, and magnetic fields, have found extensive applications in sensors, actuators, soft robots, medical devices and artificial muscles. Using three-dimensional (3D) printing techniques for fabrication of smart devices allows for complex designs and well-controlled manufacturing processes. 4D printing is attributed to the 3D printing of smart materials that can be significantly transformed over time. Herein the smart materials including hydrogels and polymeric nanocomposites used in 4D printing were reviewed and the fundamental mechanisms responsible for the functionalities were discussed in detail. In this report, 4D printing of smart systems and their applications in sensors, actuators and biomedical devices were reviewed to provide a deeper understanding of the current development and the future outlook.
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- 2020
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5. Iodine doping enabled wide range threshold voltage modulation in pentacene transistors
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Yu-Wu Wang, Ming Yue Hong, and Yu Chung Chang
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Materials science ,Field effect ,02 engineering and technology ,01 natural sciences ,law.invention ,Pentacene ,chemistry.chemical_compound ,law ,0103 physical sciences ,Materials Chemistry ,Diffusion (business) ,010302 applied physics ,Range (particle radiation) ,business.industry ,Transistor ,Metals and Alloys ,High voltage ,Surfaces and Interfaces ,021001 nanoscience & nanotechnology ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Threshold voltage ,chemistry ,Modulation ,Optoelectronics ,0210 nano-technology ,business - Abstract
We demonstrate an ultra-high range of threshold voltage modulation in pentacene transistors by iodine doping. Through diffusion control and thermal treatments, the transistor's threshold voltage can be tuned in a wide range of more than 100 V from enhance mode to deep depletion mode. The correlation between physical and electrical characteristics was investigated to elucidate the modulation mechanism. The results suggest an optimistic potential for pentacene transistors in high voltage device applications. The transistors in this research exhibit a high field effect mobility of ~0.18 cm2/Vs and on/off ratio ~105.
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- 2019
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6. Viral shedding in gastroenteritis in children caused by variants and novel recombinant norovirus infections
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Yu-Chung Chang, Shih-Yen Chen, Chung-Chan Lee, Chi-Neu Tsai, Sin-Sheng Su, Chia-Hsin Hsieh, Hung-Yen Cheng, Yin-Tai Tsai, and Hsun-Ching Chao
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Male ,Genotype ,viruses ,Taiwan ,medicine.disease_cause ,Real-Time Polymerase Chain Reaction ,03 medical and health sciences ,Feces ,fluids and secretions ,0302 clinical medicine ,medicine ,Infection control ,Humans ,030212 general & internal medicine ,Viral shedding ,Phylogeny ,Caliciviridae Infections ,Recombination, Genetic ,Inpatients ,Transmission (medicine) ,business.industry ,Norovirus ,virus diseases ,Genetic Variation ,Infant ,General Medicine ,Viral Load ,Virology ,Gastroenteritis ,Virus Shedding ,Real-time polymerase chain reaction ,030220 oncology & carcinogenesis ,Child, Preschool ,Female ,business ,Viral load - Abstract
Human norovirus (NoV) is the leading cause of acute gastroenteritis and the rapid transmission of NoV renders infection control problematic. Our study aimed to investigate viral shedding in gastroenteritis in children caused by variants of emerging norovirus strains infections.We used RNA-dependent RNA polymerase (RdRp) sequencing to measure NoV genome copies in stool to understand the relationship between the clinical manifestations and viral shedding in hospitalized patients. The near full-length NoV genome sequence was amplified via reverse transcription-polymerase chain reaction (RT-PCR) and NoV recombination was analyzed using the Recombination Analysis Tool (RAT).From January 2015 to March 2018, 77 fecal specimens were collected from hospitalized pediatric patients with confirmed NoV gastroenteritis. The NoV genotypes were GII.4 (n = 22), non-GII.4 (n = 14), GII.4 Sydney (n = 21), and GII.P16-GII.2 (n = 20). Viral load increased from days 2 to 9 from the illness onset, resulting in an irregular plateau without peaks. After day 9, the viral load declined gradually and most viral shedding in feces ceased by day 15. The average viral load was highest in GII.4 Sydney followed by GII.P16-GII.2 infections and lowest in non-GII.4 infections. GII.4 unclassified infections showed the longest viral shedding time, followed by GII.4 Sydney infections, GII.P16-GII.2 recombinant infection resulted in the shortest duration. NoVs evolved to form a group of GII.P16-GII.2 variants during the 2017 to 2018 period.The viral load and shedding period and was different in variants of NoV infections in children. High mutation rate of emerging and re-emerging variants was observed to an enhanced epidemic risk rendering continuous surveillance.
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- 2020
7. Hydrogen Evolution Reaction Monitored by Electrochemiluminescence Blinking at Single-Nanoparticle Level
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Jian-Rong Zhang, Li-Ping Jiang, Yu-Chung Chang, Wenlei Zhu, Cheng Ma, Min-Xuan Wang, Hui-Fang Wei, Shaojun Wu, Zixuan Chen, and Yuehe Lin
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Materials science ,business.industry ,Mechanical Engineering ,Nanoparticle ,Bioengineering ,Nanotechnology ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrochemistry ,Nanomaterial-based catalyst ,Nanomaterials ,Catalysis ,chemistry.chemical_compound ,Semiconductor ,chemistry ,Electrochemiluminescence ,General Materials Science ,0210 nano-technology ,business ,Carbon nitride - Abstract
Monitoring and characterization methods that provide performance tracking of hydrogen evolution reaction (HER) at the single-nanoparticle level can greatly advance our understanding of catalysts' structure and activity relationships. Electrochemiluminescence (ECL) microscopy is implemented for the first time to identify HER activities of single nanocatalysts and to provide a direction for further optimization. Here, we develop a novel ECL blinking technique at the single-nanoparticle level to directly monitor H2 nanobubbles generated from hollow carbon nitride nanospheres (HCNSs). The ECL ON and OFF mechanisms are identified being closely related to the generation, growth, and collapse of H2 nanobubbles. The power-law distributed durations of ON and OFF states demonstrate multiple catalytic sites with stochastic activities on a single HCNS. The power-law coefficients of ECL blinking increase with improved HER activities from modified HCNSs with other active HER catalysts. Besides, ECL blinking phenomenon provides an explanation for the low cathodic ECL efficiency of semiconductor nanomaterials.
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- 2020
8. Surface-Enhanced Raman Scattering and Fluorescence on Gold Nanogratings
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Yu Chung Chang, Tsung Hsien Lin, and Bo Han Huang
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Materials science ,General Chemical Engineering ,02 engineering and technology ,Photoresist ,010402 general chemistry ,01 natural sciences ,Article ,lcsh:Chemistry ,symbols.namesake ,electron beam lithography ,General Materials Science ,Thin film ,Lithography ,Plasmon ,business.industry ,021001 nanoscience & nanotechnology ,Surface plasmon polariton ,0104 chemical sciences ,Nanolithography ,lcsh:QD1-999 ,localized surface plasmon resonance (LSPR) ,symbols ,nanograting ,Optoelectronics ,nanofabrication ,0210 nano-technology ,business ,surface plasmon resonance (SPR) ,Electron-beam lithography ,Raman scattering ,surface-enhanced Raman scattering (SERS) ,surface plasmon polariton (SPP) - Abstract
Surface-enhanced Raman scattering (SERS) spectroscopy is a sensitive sensing technique. It is desirable to have an easy method to produce SERS-active substrate with reproducible and robust signals. We propose a simple method to fabricate SERS-active substrates with high structural homogeneity and signal reproducibility using electron beam (E-beam) lithography without the problematic photoresist (PR) lift-off process. The substrate was fabricated by using E-beam to define nanograting patterns on the photoresist and subsequently coat a layer of gold thin film on top of it. Efficient and stable SERS signals were observed on the substrates. In order to investigate the enhancement mechanism, we compared the signals from this substrate with those with photoresist lifted-off, which are essentially discontinuous gold stripes. While both structures showed significant grating-period-dependent fluorescence enhancement, no SERS signal was observed on the photoresist lifted-off gratings. Only transverse magnetic (TM)-polarized excitation exhibited strong enhancement, which revealed its plasmonic attribution. The fluorescence enhancement showed distinct periodic dependence for the two structures, which is due to the different enhancement mechanism. We demonstrate using this substrate for specific protein binding detection. Similar periodicity dependence was observed. Detailed theoretical and experimental studies were performed to investigate the observed phenomena. We conclude that the excitation of surface plasmon polaritons on the continuous gold thin film is essential for the stable and efficient SERS effects.
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- 2020
9. Facile and Reliable Thickness Identification of Atomically Thin Dichalcogenide Semiconductors Using Hyperspectral Microscopy
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Yu Kai Wang, Yu Chung Chang, Yen Ting Chen, and Der Yuh Lin
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Materials science ,Band gap ,General Chemical Engineering ,chemistry.chemical_element ,WS2 ,02 engineering and technology ,MoSe2 ,transition metal dichalcogenides (TMDCs) ,SnSe2 ,010402 general chemistry ,01 natural sciences ,Article ,Crystal ,lcsh:Chemistry ,symbols.namesake ,SnS2 ,Microscopy ,General Materials Science ,business.industry ,WSe2 ,thickness identification ,021001 nanoscience & nanotechnology ,2D materials ,Exfoliation joint ,0104 chemical sciences ,Semiconductor ,chemistry ,lcsh:QD1-999 ,hyperspectral microscopy ,symbols ,MoS2 ,Optoelectronics ,van der Waals force ,0210 nano-technology ,Raman spectroscopy ,business ,Tin - Abstract
Although large-scale synthesis of layered two-dimensional (2D) transition metal dichalcogenides (TMDCs) has been made possible, mechanical exfoliation of layered van der Waals crystal is still indispensable as every new material research starts with exfoliated flakes. However, it is often a tedious task to find the flakes with desired thickness and sizes. We propose a method to determine the thickness of few-layer flakes and facilitate the fast searching of flakes with a specific thickness. By using hyperspectral wild field microscopy to acquire differential reflectance and transmittance spectra, we demonstrate unambiguous recognition of typical TMDCs and their thicknesses based on their excitonic resonance features in a single step. Distinct from Raman spectroscopy or atomic force microscopy, our method is non-destructive to the sample. By knowing the contrast between different layers, we developed an algorithm to automatically search for flakes of desired thickness in situ. We extended this method to measure tin dichalcogenides, such as SnS2 and SnSe2, which are indirect bandgap semiconductors regardless of the thickness. We observed distinct spectroscopic behaviors as compared with typical TMDCs. Layer-dependent excitonic features were manifested. Our method is ideal for automatic non-destructive optical inspection in mass production in the semiconductor industry.
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- 2020
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10. Divergence of group a rotavirus with genetic variations before and after introduction of rotavirus vaccines in northern Taiwan
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Ying-Fang Elaine Chen, Shih-Yen Chen, Chi-Neu Tsai, Cheng-Hsun Chiu, Shu-Sing Kong, Yu-Chung Chang, Hsun-Ching Chao, and Chung-Chan Lee
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Male ,Rotavirus ,rotavirus vaccines ,Genotype ,viruses ,Taiwan ,Observational Study ,medicine.disease_cause ,Group A ,Rotavirus Infections ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,law ,medicine ,Prevalence ,Humans ,030212 general & internal medicine ,acute gastroenteritis ,Child ,Genotyping ,Polymerase chain reaction ,Phylogeny ,Molecular Epidemiology ,Molecular epidemiology ,business.industry ,Vaccination ,virus diseases ,General Medicine ,Rotavirus vaccine ,Virology ,Gastroenteritis ,030220 oncology & carcinogenesis ,Population Surveillance ,RNA, Viral ,Female ,business ,genetic variations ,Research Article - Abstract
Despite the development of vaccines in 2006, rotavirus is still a major cause of acute gastroenteritis worldwide. This study was performed to analyze the presence of circulating rotaviruses before and after the introduction of rotavirus vaccines to allow phylogenetic comparisons of vaccine strains in northern Taiwan. Rotavirus genotyping and sequencing of rotavirus VP7 and VP4 PCR products were performed by Reverse Transcriptase Polymerase Chain Reaction and DNA autosequencing. Phylogenies were constructed by the neighbor-joining and maximum-likelihood methods using CLUSTAL W software included in the MEGA software package (version 6.0). Between April 2004 and December 2012, a total of 101 rotavirus specimens from pediatric patients with acute gastroenteritis hospitalized in Chang Gung Children's Hospital were amplified, and their VP4 and VP7 sequences were determined. These 101 specimens consisted of 55 pre-vaccine strains (G1 [13, 23.6%], G2 [12, 21.8%], G3 [16, 29.1%], and G9 [14, 25.5%]) and 46 post-vaccine strains (G1 [25, 54.3%], G2 [12, 26.1%], G3 [5, 10.9%], and G9 [4, 8.7%]). The most common combination of the G and P types was G2P[4], accounting for 36% cases, followed by G9P[8] (25%), G1P[8] (20%), G3P[4] (15%), G3P[8] (10%), G1P[4] (5%), and G2P[8] (5%). Phylogenetic analysis showed that only the G1 and P[8] genotypes clustered in the same lineages with the rotavirus vaccine strains. Based on our results, the inclusion of G9, modified G2 and G3 with target lineages, and the combination G2P[4] and G9P[8] in the rotavirus vaccines in Taiwan is warranted as a vaccination strategy.
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- 2020
11. Carbon-doped SnS2 nanostructure as a high-efficiency solar fuel catalyst under visible light
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Satyanarayana Samireddi, Tsyr-Yan Yu, Amr Sabbah, Li-Chyong Chen, Wei-Fu Chen, Chih-I Wu, Po-Wen Chung, Fang-Yu Fu, Kuei-Hsien Chen, Yu-Chung Chang, Ming-Chang Lin, Indrajit Shown, Po Han Chang, and Raghunath Putikam
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Nanostructure ,Materials science ,Science ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Artificial photosynthesis ,Catalysis ,lcsh:Science ,Multidisciplinary ,business.industry ,General Chemistry ,021001 nanoscience & nanotechnology ,Solar fuel ,Solar energy ,0104 chemical sciences ,Chemical engineering ,Photocatalysis ,lcsh:Q ,Quantum efficiency ,0210 nano-technology ,business ,Visible spectrum - Abstract
Photocatalytic formation of hydrocarbons using solar energy via artificial photosynthesis is a highly desirable renewable-energy source for replacing conventional fossil fuels. Using an l-cysteine-based hydrothermal process, here we synthesize a carbon-doped SnS2 (SnS2-C) metal dichalcogenide nanostructure, which exhibits a highly active and selective photocatalytic conversion of CO2 to hydrocarbons under visible-light. The interstitial carbon doping induced microstrain in the SnS2 lattice, resulting in different photophysical properties as compared with undoped SnS2. This SnS2-C photocatalyst significantly enhances the CO2 reduction activity under visible light, attaining a photochemical quantum efficiency of above 0.7%. The SnS2-C photocatalyst represents an important contribution towards high quantum efficiency artificial photosynthesis based on gas phase photocatalytic CO2 reduction under visible light, where the in situ carbon-doped SnS2 nanostructure improves the stability and the light harvesting and charge separation efficiency, and significantly enhances the photocatalytic activity. Photocatalytic reduction of CO2 to hydrocarbons is a promising route to both CO2 utilization and renewable fuel production. Here the authors identify that carbon-doped SnS2 possesses a high catalytic efficiency towards CO2 reduction owing to low photogenerated charge recombination rates.
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- 2018
12. Rapid thickness and optoelectronic properties characterization of few-layer 2D materials based on hyperspectral microscopy
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Yu Kai Wang, Yu Chung Chang, and Der Yuh Lin
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Materials science ,Absorption spectroscopy ,business.industry ,Hyperspectral imaging ,Single step ,02 engineering and technology ,01 natural sciences ,Characterization (materials science) ,010309 optics ,Wavelength ,020210 optoelectronics & photonics ,0103 physical sciences ,Microscopy ,0202 electrical engineering, electronic engineering, information engineering ,Transmittance ,Optoelectronics ,business ,Layer (electronics) - Abstract
We present a technique to efficiently identify the thickness and properties of typical 2D materials. By taking microscopic images at a series wavelengths, we obtain reflectance, transmittance and absorption spectra in a single step. We demonstrate using the setup to unambiguously determine the thickness of MoS2 flakes and their excitonic properties.
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- 2019
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13. Controlling the Nanoscale Gaps on Silver Island Film for Efficient Surface-Enhanced Raman Spectroscopy
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Yu Chung Chang, Yu-Ju Hung, and Yu Chun Lu
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Materials science ,Scanning electron microscope ,General Chemical Engineering ,02 engineering and technology ,Bending ,Substrate (electronics) ,010402 general chemistry ,01 natural sciences ,silver island film ,lcsh:Chemistry ,symbols.namesake ,General Materials Science ,Surface plasmon resonance ,Nanoscopic scale ,business.industry ,Surface-enhanced Raman spectroscopy ,021001 nanoscience & nanotechnology ,Evaporation (deposition) ,0104 chemical sciences ,lcsh:QD1-999 ,symbols ,Optoelectronics ,0210 nano-technology ,business ,surface plasmon resonance ,Raman scattering ,surface-enhanced Raman scattering (SERS) - Abstract
We control the nanoscale gaps on silver island films by different processing methods and investigate the surface-enhanced Raman scattering (SERS) efficiency on the films. We propose a facile technique to control the film morphology by substrate bending while keeping the evaporation rate constant. The films developed by our new method are compared to the films developed by traditional methods at various evaporation rates. The SERS signals generated on the samples prepared by the new method have similar strengths as the traditional methods. Substrate bending allows us to reduce the gap sizes while using a higher evaporation rate, hence the film can be developed in a shorter time. This cost-effective and time-efficient method is suitable for the mass production of large-area SERS sensors with good sensitivity. Scanning electron microscope images are analyzed to quantify the gap densities and widths to elucidate the relationship between the film morphology and the SERS intensity. While the gap size appears to be the major factor influencing the enhancement, the shape of the nano-island also seems to influence the SERS efficiency.
- Published
- 2019
14. Smartphone Optosensing Platform Using a DVD Grating to Detect Neurotoxins
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Lei Li, Yuehe Lin, Allison T. Osmanson, Dan Du, Li-Ju Wang, Xiaoxiao Ge, and Yu-Chung Chang
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Fluid Flow and Transfer Processes ,Detection limit ,3d printed ,Materials science ,Spectrometer ,Pixel ,business.industry ,Process Chemistry and Technology ,Visible spectral range ,010401 analytical chemistry ,Bioengineering ,02 engineering and technology ,Grating ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Microplate Reader ,Optics ,0210 nano-technology ,business ,Instrumentation ,Diffraction grating - Abstract
We present a smartphone optosensing platform (SOP) using a digital versatile disc (DVD) diffraction grating for rapid in-field detecting neurotoxins. The smartphone holder and sample holder were 3D printed for the SOP. A DVD grating is demonstrated for the first time in a low-cost miniature spectrometer on the SOP to quantify the concentrations of neurotoxins. The SOP is capable of detecting optical absorbance spectra within the entire visible spectral range from 400 to 700 nm with the spectral resolution of 0.2521 nm/pixel. We demonstrated the performance of the DVD grating compared with a commercial transmission grating on the SOP and a conventional microplate reader. Paraoxon, as the selected neurotoxin model, is assayed by two types of cholinesterase (ChE) on our SOP, respectively. Integrating a DVD grating in the SOP allows quantification of paraoxon in the range from 5 nM to 25 μM with the detection limit of 2.9 nM. In addition to the low assessed detection limit at medically relevant concentrations...
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- 2016
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15. An Ultra-Sensitive Liquid-Level Indicator Based on an Etched Chirped-Fiber Bragg Grating
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Hung-Ying Chang, Wen-Fung Liu, Hao-Jan Sheng, Ming-Yue Fu, Raman Kashyap, and Yu Chung Chang
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PHOSFOS ,Materials science ,business.industry ,010401 analytical chemistry ,Physics::Optics ,Polarization-maintaining optical fiber ,02 engineering and technology ,Grating ,Long-period fiber grating ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,020210 optoelectronics & photonics ,Optics ,Fiber Bragg grating ,Fiber optic sensor ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,Electrical and Electronic Engineering ,Plastic optical fiber ,business ,Photonic-crystal fiber - Abstract
A novel ultra-sensitive liquid-level indicator using an etched chirped fiber Bragg grating is experimentally demonstrated with a sensitivity of 1.214 nm/mm for detecting tens of micro-meter liquid-level variation. The operation mechanism is based on the superposition wavelength-peak shift created by the overlap between the spectrum of the etched CFBG section immersed in the liquid and the spectrum of the rest of the grating in air. This sensor may be used to precisely measure the liquid-level variation in bio-hazardous systems or industrial containers that demand accurate interrogation of the amounts of the contents.
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- 2016
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16. Emerging Applications of Additive Manufacturing in Biosensors and Bioanalytical Devices
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Yuehe Lin, Xiaofan Ruan, Lei Li, Yu-Chung Chang, Xiangheng Niu, Dan Du, Yijia Wang, and Nan Cheng
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Bioanalysis ,Materials science ,Mechanics of Materials ,business.industry ,3D printing ,General Materials Science ,Nanotechnology ,business ,Biosensor ,Industrial and Manufacturing Engineering - Published
- 2020
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17. Fabrication of aspherical polymeric lenses using tunable ferrogel molds
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Yu-Chung Chang, Allen Y. Yi, Lei Li, Parvaneh Ahmadvand, Mojtaba Falahati, and Wenchen Zhou
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Fabrication ,Materials science ,business.industry ,Physics::Optics ,medicine.disease_cause ,Elastomer ,01 natural sciences ,Casting ,Magnetic susceptibility ,Atomic and Molecular Physics, and Optics ,law.invention ,Hyperbola ,Magnetic field ,010309 optics ,Lens (optics) ,Optics ,law ,Mold ,0103 physical sciences ,medicine ,Electrical and Electronic Engineering ,business ,Engineering (miscellaneous) - Abstract
The majority of optical lenses have spherical surface profiles because they are convenient to fabricate. Replacing spherical optics with aspheric optics leads to smaller size, lighter weight, and less complicated optical systems with a superior imaging quality. However, fabrication of aspheric lenses is expensive and time-consuming. Here, we introduce a straightforward and low-cost casting method to fabricate polymeric aspheric lenses. An elastomeric ferrogel was formed into an aspherical profile by using a designed magnetic field and then was used as a mold. Different types of aspherical profiles from parabola to hyperbola can be formed with this method by tuning the magnetic field. A home-built Shack–Hartmann sensor was employed to characterize the cast polymeric lenses. The effects of magnetic field intensity, gradient of the magnetic field, and magnetic susceptibility of the ferrogel on the lens profiles were investigated. This technique can be used for rapid-forming polymeric aspherical lenses with different sizes and shapes.
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- 2020
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18. Hydrophone Based on a Fiber Bragg Grating
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Teng-Lung Wang, Wen-Fung Liu, Ming-Yue Fu, Chan-Yu Kuo, Hung-Ying Chang, and Yu Chung Chang
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Frequency response ,Materials science ,Electromagnetics ,Optics ,Hydrophone ,Fiber Bragg grating ,Tension (physics) ,business.industry ,Physics::Optics ,Acoustic wave ,Fiber ,Underwater ,business - Abstract
We demonstrate a novel fiber-optic hydrophone by using a fiber Bragg grating as a sensing element for underwater acoustic wave detection. The effects of fiber diameter, fiber tension, film thickness, and film radii are investigated for optimal performance.
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- 2018
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19. Ultra low-cost, portable smartphone optosensors for mobile point-of-care diagnostics
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Yu-Chung Chang, Li-Ju Wang, Rongrong Sun, and Lei Li
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Healthcare delivery ,Computer science ,Optical sensing ,business.industry ,Point-of-care testing ,Embedded system ,Usability ,business ,Point of care - Abstract
Smartphone optosensors with integrated optical components make mobile point-of-care (MPoC) diagnostics be done near patients’ side. It’ll especially have a significant impact on healthcare delivery in rural or remote areas. Current FDA-approved PoC devices achieving clinical level are still at high cost and not affordable in rural hospitals. We present a series of ultra low-cost smartphone optical sensing devices for mobile point-of-care diagnosis. Aiming different targeting analytes and sensing mechanisms, we developed custom required optical components for each smartphone optosensros. These optical devices include spectrum readers, colorimetric readers for microplate, lateral flow device readers, and chemiluminescence readers. By integrating our unique designed optical components into smartphone optosening platform, the anlaytes can be precisely detected. Clinical testing results show the clinical usability of our smartphone optosensors. Ultra low-cost portable smartphone optosensors are affordable for rural/remote doctors.
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- 2018
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20. Current Advancements of the Smartphone - Based Point - Of - Carediagnosis
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Yu-Chung Chang, Li-Ju Wang, Rongrong Sun, and Lei Li
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Mobile Health ,business.industry ,Computer science ,Paper Strip ,Electrical engineering ,Point (geometry) ,Smartphone ,Current (fluid) ,business ,Point-Of-Care (POC) Diagnosis - Abstract
The recent advancement in smartphone technology has triggered a wide range of smartphone point-of-care (POC) technology especially for the application of biomedical diagnosis and environmental detections. Modern smartphones with powerful processors and the functional cameras have been considered as the best candidate for miniaturization of the analytical instruments. Smartphones integrated with micro fluidic chips or optical components are capable of detecting specific biomarkers, antigens or pathogens in situ. The merits of smartphone-based POC devices, including cost efficiency, on-site detection, instantly obtaining diagnostic results, and transmittable data, make it grooming in medical and environmental diagnosis, especially in remote areas and at home. Therefore, smartphone-based POC technology could achieve decentralizing laboratory tests which fastens turnaround time and let doctors timely treat patients. In this review, we focus on paper-based and liquidbased smartphone POC devices of recent years to overviews current advancements.
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- 2018
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21. Pringle’s Maneuver With a Releasable Insulok Band
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Yu-Chung Chang
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Lesser omentum ,medicine.medical_specialty ,Portal triad ,business.industry ,medicine.medical_treatment ,Ischemic time ,Hilum (biology) ,Equipment Design ,Partial hepatectomy ,Lesser sac ,Surgery ,medicine.anatomical_structure ,Liver ,medicine ,Foramen ,Hepatectomy ,Humans ,business - Abstract
Background. Currently, there are many conventional instruments being applied to perform hepatic inflow control, the Pringle’s maneuver, distal to the hepatic hilum during hepatic resections. We wondered if a commonly used Insulok band can be added. Materials and Methods. Insulok band is a plastic tying device molded in one piece with an excellent cam-lock mechanism. We have applied releasable Insulok band to the Pringle’s maneuver in 10 partial hepatectomy cases, which are not suitable for application of Chang’s needle. After opening the lesser omentum, the band was passed through the Winslow foramen to the lesser sac, and the portal triad was occluded by locking the band. During the intermittent reperfusion period, this Insulok band allowed easy and fast control of hepatic inflow with its simple releasable locking device. Results. Single inflow block was used on 6 cases while repeated block on 4 cases for partial hepatectomy. The average ischemic time was 15.2 ± 8.2 minutes with an interval of 5 minutes. There was neither procedure-related morbidity nor mortality. No patient had developed postoperative hepatic failure or prolonged liver dysfunction. The efficacy of bleeding control was excellent and the average blood loss during Pringle’s maneuver was 6 ± 12.6 mL. Furthermore, locking and unlocking of the Insulok band each took only 5 seconds. Conclusion. Releasable Insulok band is a simpler, faster, cheaper, and safe alternative to the conventional methods for blocking hepatic inflow in Pringle’s maneuver, especially in those cases not suitable for using the Chang’s needle.
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- 2015
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22. An ultra-low-cost smartphone octochannel spectrometer for mobile health diagnostics
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Yu-Chung Chang, Malek Kamoun, Li-Ju Wang, Ping Wang, Nicole Naudé, Anne Crivaro, and Lei Li
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0301 basic medicine ,Telemedicine ,Computer science ,Point-of-Care Systems ,General Physics and Astronomy ,02 engineering and technology ,General Biochemistry, Genetics and Molecular Biology ,Article ,03 medical and health sciences ,Animals ,Humans ,General Materials Science ,mHealth ,Potential impact ,Spectrometer ,business.industry ,General Engineering ,Serum Albumin, Bovine ,General Chemistry ,Equipment Design ,021001 nanoscience & nanotechnology ,Serum samples ,Light intensity ,030104 developmental biology ,Spectrophotometry ,Costs and Cost Analysis ,Cattle ,Smartphone ,User interface ,0210 nano-technology ,business ,Mobile device ,Computer hardware - Abstract
With the rapid development and proliferation of mobile devices with powerful computing power and the ability of integrating sensors into mobile devices, the potential impact of mobile health (mHealth) diagnostics on the public health is drawing researchers' attention. We developed a Smartphone Octo-channel Spectrometer (SOS) as a mHealth diagnostic tool. The SOS has nanoscale wavelength resolution, is self-illuminated from the smartphone itself, and is ultra-low cost (less than $20). A user interface controls the optical sensing parameters and precise alignment. After calibrating and testing the SOS by quantifying protein concentrations, we clinically validated the SOS by comparing the diagnostic performance of our device with that of a clinical spectrophotometer. About 180 serum samples from de-identified patients with 4 types of autoantibodies were blindly read the ELISA results. The accuracy of the SOS achieved 100% across the clinical reportable range compared with the FDA-approved instrument. Furthermore, the self-illuminated SOS only requires about half of the light intensity of the FDA-approved instrument to achieve clinical-level sensitivity. The low-energy-consumption and low-cost SOS enables point-of-care spectrophotometric sensing in low-resource areas, and can be integrated into point-of-care diagnostic systems for rapid multiplex readout and analysis at patient bedside or at home.
- Published
- 2017
23. A Highly Sensitive Two-Dimensional Inclinometer Based on Two Etched Chirped-Fiber-Grating Arrays
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Hung Ying Chang, Yu Chung Chang, and Wen Fung Liu
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chirped fiber Bragg grating (CFBG) ,Materials science ,etched fiber Bragg grating ,Tiltmeter ,Physics::Optics ,02 engineering and technology ,lcsh:Chemical technology ,01 natural sciences ,Biochemistry ,Article ,Analytical Chemistry ,010309 optics ,Superposition principle ,020210 optoelectronics & photonics ,Optics ,Fiber Bragg grating ,Etching (microfabrication) ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,Instrumentation ,level meter ,inclinometer ,tilt meter ,fiber sensor ,business.industry ,Atomic and Molecular Physics, and Optics ,Wavelength ,Tilt (optics) ,Reflection (physics) ,Inclinometer ,business - Abstract
We present a novel two-dimensional fiber-optic inclinometer with high sensitivity by crisscrossing two etched chirped fiber Bragg gratings (CFBG) arrays. Each array is composed of two symmetrically-arranged CFBGs. By etching away most of the claddings of the CFBGs to expose the evanescent wave, the reflection spectra are highly sensitive to the surrounding index change. When we immerse only part of the CFBG in liquid, the effective index difference induces a superposition peak in the refection spectrum. By interrogating the peak wavelengths of the CFBGs, we can deduce the tilt angle and direction simultaneously. The inclinometer has a resolution of 0.003° in tilt angle measurement and 0.00187 rad in tilt direction measurement. Due to the unique sensing mechanism, the sensor is temperature insensitive. This sensor can be useful in long term continuous monitoring of inclination or in real-time feedback control of tilt angles, especially in harsh environments with violent temperature variation.
- Published
- 2017
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24. Optical Asymmetry and Nonlinear Light Scattering from Colloidal Gold Nanorods
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Miao-Bin Lien, Nicholas A. Kotov, H. Ferguson, John C. Schotland, Yimei Zhu, You-Chia Chang, Myung-Geun Han, Yu Chung Chang, Theodore B. Norris, Ji Young Kim, and Andrew A. Herzing
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Photoluminescence ,Materials science ,business.industry ,Scattering ,General Engineering ,Nanophotonics ,Physics::Optics ,General Physics and Astronomy ,Nonlinear optics ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Molecular physics ,Light scattering ,0104 chemical sciences ,Optoelectronics ,General Materials Science ,Nanorod ,Surface plasmon resonance ,0210 nano-technology ,business ,Plasmon - Abstract
A systematic study is presented of the intensity-dependent nonlinear light scattering spectra of gold nanorods under resonant excitation of the longitudinal surface plasmon resonance (SPR). The spectra exhibit features due to coherent second and third harmonic generation as well as a broadband feature that has been previously attributed to multiphoton photoluminescence arising primarily from interband optical transitions in the gold. A detailed study of the spectral dependence of the scaling of the scattered light with excitation intensity shows unexpected scaling behavior of the coherent signals, which is quantitatively accounted for by optically induced damping of the SPR mode through a Fermi liquid model of the electronic scattering. The broadband feature is shown to arise not from luminescence, but from scattering of the second-order longitudinal SPR mode with the electron gas, where efficient excitation of the second order mode arises from an optical asymmetry of the nanorod. The electronic-temperature-dependent plasmon damping and the Fermi-Dirac distribution together determine the intensity dependence of the broadband emission, and the structure-dependent absorption spectrum determines the spectral shape through the fluctuation-dissipation theorem. Hence a complete self-consistent picture of both coherent and incoherent light scattering is obtained with a single set of physical parameters.
- Published
- 2017
25. Simplified Liver Splitting Technique Using a Curved Chang’s Needle
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Yu-Chung Chang, Chu-San Chen, Aiken Wang, and Naofumi Nagasue
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medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Liver transplantation ,Inferior vena cava ,Liver lobectomy ,Liver regeneration ,Surgery ,medicine.vein ,medicine ,Hepatectomy ,Cadaveric spasm ,Living donor liver transplantation ,business ,Venous return curve - Abstract
Liver-splitting techniques been previously developed for ex vivo and in situ cadaveric liver transplantation, and more recently for in situ living donor liver transplantation or liver partition with a portal vein ligation for a staged hepatectomy. We report a novel and simplified technique using a long curved needle to make whole-thickness mattress sutures along the division line of the remnant liver above the inferior vena cava to control bleeding, and then bloodlessly splitting the liver with scissors within 40 min in a case of a left lobectomy with metastases from breast cancer. The patient was uneventfully discharged on the fourth postoperative day. When a liver lobectomy or partition to enhance liver regeneration for a staged hepatectomy is necessary, this technique can be done straightforwardly without concern for the problems of venous return or congestion of the recipient or remnant donor liver. This technique is probably the simplest and fastest way for any surgeon and any facility.
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- 2017
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26. Three Steps for a Safe Pancreaticoduodenectomy: Neither Pancreatic Texture nor Duct Size Matters
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Yu-Chung Chang
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medicine.medical_specialty ,Whipple's operation ,Saline irrigation ,business.industry ,medicine.medical_treatment ,Pylorus preserving pancreaticoduodenectomy ,Anastomosis ,Jejunal loop ,Pancreaticoduodenectomy ,Surgery ,medicine.anatomical_structure ,Pancreatic juice ,medicine ,business ,Duct (anatomy) - Abstract
Background: I have designed a Q-shape biliary diversion pancreaticoduodenectomy (PD) to prevent delayedhemorrhage in case of pancreaticojejunostomy (PJ) leakage. However, eliminating PJ leakage is the ultimate goal. A PJ anastomosis technique, irrespective of soft pancreatic texture or duct-size, has been found. Methods: Nine PDs were included. An end-to-side anastomosed proximal jejunal loop (30 cm), divided by a GIA stapler at its top and reapproximated using serosal sutures, was used for a choledochojejunostomy and PJs (4 fistulation, 2 duct-to-mucosa, 1 conventional and 2 whole-thickness mattress end-to-side sutures) at each divided loop. Finally, a gastro/duodenojejunostomy was made 30 cm distal to this looped jejunojejunostomy. Results: There was no mortality. One minor PJ leakage healed spontaneously. One major PJ leakage had a delayed-hemorrhage crisis salvaged by continuous normal saline irrigation to neutralize the pH condition for bile and pancreatic juice interaction. The clinical courses were surprisingly uneventful and without fear of leakage in two PJs using whole-thickness mattress sutures. Secure ties without tearing were possible in the soft pancreatic texture. Conclusion: Current evolutional strategies of biliary diversion reconstruction with whole-thickness-mattress PJ sutures plus normal saline irrigation can increase the safety of a pancreaticoduodenectomy by reducing PJ leakage and preventing the activation of pancreatic juice to eliminate a lethal delayed-hemorrhage.
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- 2017
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27. Is it Justified to use the Lapse Day as a Decision Maker of Laparoscopic Cholecystectomy for Symptomatic Gall Bladder Stone Disease
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Yu-Chung Chang
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medicine.medical_specialty ,business.industry ,Incidence (epidemiology) ,Gallbladder ,medicine.medical_treatment ,Hepatoduodenal ligament ,Omics ,medicine.disease ,Surgery ,medicine.anatomical_structure ,Cholecystitis ,medicine ,Cholecystectomy ,Complication ,business ,Bladder stone - Abstract
Aim: Lapse from symptom onset to surgery has been traditionally used for the operation timing of cholecystectomy. However, intraoperative gallbladder (GB) inflammation status has never been studied to verify its justification.Methods: Meticulous intraoperative inflammation status of 260 consecutive laparoscopic cholecystectomy (LC) patients with symptomatic GB stone disease was prospectively graded (I-VI). Inflammation status in terms of lapse, incidence of difficult GB, complication and conversion rate from LC to open cholecystectomy was retrospectively analysed.Results: Various inflammation grades were non-significantly different in each lapse group irrespective of the lapse time. Severity is not always proportionally increased to the lapse time in every patient. One hundred seventeen patients (45%) had inflammations beyond the GB that reached Calot’s triangle or the hepatoduodenal ligament (Grade IV~VI): 64 (54.7%) were Grade V or VI and were defined as difficult GB. There were no statistically significant differences in terms of incidence of difficult GB, or conversion rate between the lapse groups. When divided into any two lapse groups, only the ≤ 3 and >3 days groups showed a significant difference (P=0.039) in the incidence of difficult GB. But the conversion rate was not significantly different (P=0.388).Conclusion: A majority of the patients were easily manageable despite the different lapse times. Less than onethird of the patients with difficult GB needed earlier LC to avert subsequent progression of dense fibrosis if delayed. Dichotomized lapse determination for LC without considering intraoperative inflammation status is not justified.
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- 2017
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28. A hub location inventory model for bicycle sharing system design: Formulation and solution
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Ta-Hui Yang, Yu-Chung Chang, and Jenn-Rong Lin
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Optimal design ,Engineering ,Mathematical optimization ,Optimization problem ,General Computer Science ,Operations research ,business.industry ,Total cost ,General Engineering ,Facility location problem ,Strategic design ,Public transport ,Service level ,Systems design ,business - Abstract
This study addresses a strategic design problem for bicycle sharing systems incorporating bicycle stock considerations. The problem is formulated as a hub location inventory model. The key design decisions considered are: the number and locations of bicycle stations in the system, the creation of bicycle lanes between bicycle stations, the selection of paths of users between origins and destinations, and the inventory levels of sharing bicycles to be held at the bicycle stations. The design decisions are made with consideration for both total cost and service levels (measured both by the availability rate for rental requests at the pick-up rental stations and coverage of the origins and destinations). The optimal design of this system requires an integrated view of the travel costs of users, bicycle inventory costs and facility costs of bicycle stations and bicycle lanes as well as service levels. The purpose of this study is to create a formal model that provides such an integrated view, and to develop methods for obtaining solutions for the design variables in practical situations. The complexity of the problem precludes the exact solution of the optimization problem for instances of realistic size, and so we propose a heuristic method for efficiently finding near-optimal solutions. In the test problem for which enumeration is possible, the heuristic solution is within 2% optimal. Finally, a numerical example is created to illustrate the model and proposed solution algorithm.
- Published
- 2013
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29. A multichannel smartphone optical biosensor for high-throughput point-of-care diagnostics
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Li-Ju Wang, Rongrong Sun, Yu-Chung Chang, and Lei Li
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Channel (digital image) ,Computer science ,Point-of-Care Systems ,Biomedical Engineering ,Biophysics ,Analytical chemistry ,02 engineering and technology ,Biosensing Techniques ,01 natural sciences ,Optics ,Limit of Detection ,Electrochemistry ,Animals ,Humans ,Sensitivity (control systems) ,Throughput (business) ,Immunoassay ,Pixel ,Spectrometer ,business.industry ,Interleukin-6 ,010401 analytical chemistry ,Serum Albumin, Bovine ,General Medicine ,Equipment Design ,021001 nanoscience & nanotechnology ,Sample (graphics) ,0104 chemical sciences ,High-Throughput Screening Assays ,Transmission (telecommunications) ,Spectrophotometry ,Cattle ,Smartphone ,0210 nano-technology ,business ,Biotechnology ,Data transmission - Abstract
Current reported smartphone spectrometers are only used to monitor or measure one sample at a time. For the first time, we demonstrate a multichannel smartphone spectrometer (MSS) as an optical biosensor that can simultaneously optical sense multiple samples. In this work, we developed a novel method to achieve the multichannel optical spectral sensing with nanometer resolution on a smartphone. A 3D printed cradle held the smartphone integrated with optical components. This optical sensor performed accurate and reliable spectral measurements by optical intensity changes at specific wavelength or optical spectral shifts. A custom smartphone multi-view App was developed to control the optical sensing parameters and to align each sample to the corresponding channel. The captured images were converted to the transmission spectra in the visible wavelength range from 400nm to 700nm with the high resolution of 0.2521nm per pixel. We validated the performance of this MSS via measuring the concentrations of protein and immunoassaying a type of human cancer biomarker. Compared to the standard laboratory instrument, the results sufficiently showed that this MSS can achieve the comparative analysis detection limits, accuracy and sensitivity. We envision that this multichannel smartphone optical biosensor will be useful in high-throughput point-of-care diagnostics with its minimizing size, light weight, low cost and data transmission function.
- Published
- 2016
30. A High-sensitivity Two-dimensional Inclinometer Based on Two-array-etched-chirped Fiber Gratings
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Chin-Chi Liu, Hung-Ying Chang, Wen-Fung Liu, and Yu Chung Chang
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PHOSFOS ,Materials science ,Optical fiber ,business.industry ,Physics::Optics ,Polarization-maintaining optical fiber ,02 engineering and technology ,Graded-index fiber ,law.invention ,020210 optoelectronics & photonics ,Optics ,Fiber Bragg grating ,law ,Fiber optic sensor ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,business ,Plastic optical fiber ,Photonic-crystal fiber - Abstract
We present a novel high-sensitivity dual-axis fiber inclinometer based on two etched chirped fiber Bragg gratings arrays capable of measuring the tilted angle and the direction of tilting simultaneously with a resolution of 0.02°.
- Published
- 2016
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31. Reinforcement Learning for Improving Gene Identification Accuracy by Combination of Gene-Finding Programs
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Shih-Ren Yang, Peng-Yeng Yin, Yu-Chung Chang, and Shyong Jian Shyu
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Statistics and Probability ,Control and Optimization ,Computer science ,business.industry ,Gene prediction ,Genome database ,Machine learning ,computer.software_genre ,DNA sequencing ,Computer Science Applications ,Computational Mathematics ,Identification (information) ,Annotation ,ComputingMethodologies_PATTERNRECOGNITION ,Computational Theory and Mathematics ,Modeling and Simulation ,Reinforcement learning ,Decision Sciences (miscellaneous) ,Artificial intelligence ,business ,Gene ,computer - Abstract
Due to the explosive and growing size of the genome database, the discovery of gene has become one of the most computationally intensive tasks in bioinformatics. Many such systems have been developed to find genes; however, there is still some room to improve the prediction accuracy. This paper proposes a reinforcement learning model for a combination of gene predictions from existing gene-finding programs. The model learns the optimal policy for accepting the best predictions. The fitness of a policy is reinforced if the selected prediction at a nucleotide site correctly corresponds to the true annotation. The model searches for the optimal policy which maximizes the expected prediction accuracy over all nucleotide sites in the sequences. The experimental results demonstrate that the proposed model yields higher prediction accuracy than that obtained by the single best program.
- Published
- 2012
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32. Optical fiber-based in vivo quantification of growth factor receptors
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Jing Yong Ye, Alina Kotlyar, Suyang Qin, Rameshwer Shukla, Yu Chung Chang, James R. Baker, Theodore B. Norris, Zhengyi Cao, and Thommey P. Thomas
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Cancer Research ,Receptor, ErbB-2 ,Mice, Nude ,Antibodies, Monoclonal, Humanized ,Article ,Mice ,Growth factor receptor ,In vivo ,Cell Line, Tumor ,Neoplasms ,medicine ,Animals ,Receptors, Growth Factor ,Epidermal growth factor receptor ,skin and connective tissue diseases ,Receptor ,Optical Fibers ,Fluorescent Dyes ,Alexa Fluor ,Cetuximab ,biology ,business.industry ,Carbocyanines ,Trastuzumab ,Molecular biology ,ErbB Receptors ,Oncology ,Cancer cell ,Cancer research ,biology.protein ,Immunohistochemistry ,Female ,business ,medicine.drug - Abstract
BACKGROUND: Growth factor receptors such as epidermal growth factor receptor 1 and human epidermal growth receptor 2 (HER2) are overexpressed in certain cancer cells. Antibodies against these receptors (eg. cetuximab and transtuzumab [Herceptin]) have shown therapeutic value in cancer treatment. The existing methods for the quantification of these receptors in tumors involve immunohistochemistry or DNA quantification, both in extracted tissue samples. The goal of the study was to evaluate whether an optical fiber-based technique can be used to quantify the expression of multiple growth factor receptors simultaneously. METHODS: The authors examined HER2 expression using the monoclonal antibody trastuzumab as a targeting ligand to test their system. They conjugated trastuzumab to 2 different Alexa Fluor dyes with different excitation and emission wavelengths. Two of the dye conjugates were subsequently injected intravenously into mice bearing HER2-expressing subcutaneous tumors. An optical fiber was then inserted into the tumor through a 30-gauge needle, and using a single laser beam as the excitation source, the fluorescence emitted by the 2 conjugates was identified and quantified by 2-photon optical fiber fluorescence. RESULTS: The 2 conjugates bound to the HER2-expressing tumor competitively in a receptor-specific fashion, but they failed to bind to a similar cell tumor that did not express HER2. The concentration of the conjugate present in the tumor as determined by 2-photon optical fiber fluorescence was shown to serve as an index of the HER2 expression levels. CONCLUSIONS: These studies offer a minimally invasive technique for the quantification of tumor receptors simultaneously. Cancer 2012;. © 2011 American Cancer Society.
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- 2011
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33. Effects of Sesame Oil Against After the Onset of Acetaminophen-Induced Acute Hepatic Injury in Rats
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Ming Yie Liu, Victor Raj Mohan Chandrasekaran, Dur Zong Hsu, Yu Chung Chang, and Se Ping Chien
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Male ,medicine.medical_specialty ,Necrosis ,Medicine (miscellaneous) ,Pharmacology ,Antioxidants ,Sesamum ,Lipid peroxidation ,chemistry.chemical_compound ,Blood serum ,Superoxides ,medicine ,Animals ,Aspartate Aminotransferases ,Antipyretic ,Rats, Wistar ,Acetaminophen ,Aconitate Hydratase ,chemistry.chemical_classification ,Liver injury ,Reactive oxygen species ,Nutrition and Dietetics ,Hydroxyl Radical ,business.industry ,Centrilobular necrosis ,digestive, oral, and skin physiology ,Alanine Transaminase ,Analgesics, Non-Narcotic ,medicine.disease ,Glutathione ,Mitochondria ,Rats ,Surgery ,Liver ,chemistry ,Lipid Peroxidation ,Chemical and Drug Induced Liver Injury ,medicine.symptom ,business ,Sesame Oil ,Phytotherapy ,medicine.drug - Abstract
Acetaminophen (APAP) is a safe and effective analgesic and antipyretic when used at therapeutic levels. However, an acute or cumulative overdose can cause severe liver injury with the potential to progress to liver failure in humans and experimental animals. Much attention has been paid to the development of an antioxidant that protects against APAP-induced acute hepatic injury. Hence, we aimed to investigate the effect of sesame oil against after the onset of acute hepatic injury in APAP-overdosed rats.Male Wistar rats were first given 2 oral doses (1,000 mg/kg each) of APAP (at 0 and 24 hours) and then 1 oral dose of sesame oil (8 mL/kg at 24 hours).After 48 hours, APAP increased aspartate and alanine aminotransferase levels in the rats' serum and centrilobular necrosis in liver tissue. In addition, APAP significantly decreased the rats' glutathione levels and mitochondrial aconitase activity, but increased superoxide anion, hydroxyl radical, and lipid peroxidation levels. Oral sesame oil (8 mL/kg, given at 24 hours) reversed all APAP-altered parameters and protected the rats against APAP-induced acute liver injury.We hypothesize that sesame oil acts as a useful agent that maintains intracellular glutathione levels and inhibits reactive oxygen species, thereby protecting rats against after the onset of APAP-induced acute oxidative liver injury.
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- 2010
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34. No Debridement Is Necessary for Symptomatic or Infected Acute Necrotizing Pancreatitis: Delayed, Mini-Retroperitoneal Drainage for Acute Necrotizing Pancreatitis Without Debridement and Irrigation
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Hong-Min Tsai, Chia-Hao Chang, Jen Pin Chuang, Xi-Zhang Lin, and Yu-Chung Chang
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medicine.medical_specialty ,Abdominal pain ,Pancreatic disease ,Physiology ,medicine.medical_treatment ,Perforation (oil well) ,Internal medicine ,medicine ,Humans ,Retroperitoneal Space ,Derivation ,Therapeutic Irrigation ,Retrospective Studies ,Aged, 80 and over ,Debridement ,Pancreatitis, Acute Necrotizing ,business.industry ,Contraindications ,Gastroenterology ,Bacterial Infections ,Hepatology ,medicine.disease ,Surgery ,Food intolerance ,Treatment Outcome ,Drainage ,Pancreatitis ,medicine.symptom ,Tomography, X-Ray Computed ,business ,Follow-Up Studies - Abstract
We sought to determine if necrosectomy can be omitted for complicated acute necrotizing pancreatitis (ANP). Since 1996, we prospectively performed retroperitoneal drainage by introducing a sump drain to the pancreatic head area via a small left flank incision without debridement and irrigation on 19 consecutive complicated ANP patients. We purposely delayed surgery until liquefaction of retroperitoneal tissue reached the left flank. Our patients had a mean Ranson's and APACHE II score of 5.9 (range, 4-8) and 20.1(range, 4-45), respectively. Sixteen available CT showed retroperitoneal liquefaction after 21.3 days (range, 14-26). Operations were delayed for 4.7 weeks (range, 1.3-9.0). No patient succumbed during this period. The indications were infected necrosis in 16 and severe abdominal pain/food intolerance in 3 patients. Average skin incision was 4.0 cm (range, 3-9). Fungi or bacteria were cultured in 15 patients (80.0%). The recovery courses were surprisingly uneventful. Oral intake began within 2.4 days (range, 1-5) and mean hospital stay (16 survivals) was 23.2 days (range, 4-120) after operation. Drains were completely removed 120.6 days (range, 60-250) later from these outpatients. One gastric perforation and one minor duodenal leak were the only procedure-related complications (10.5%). Three patients died (15.8%), although one had a healed ANP. In conclusion, this delay-until-liquefaction strategy without necrosectomy is an easy and effective treatment method.
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- 2006
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35. Stopping pancreaticoduodenectomy-leakage-induced intractable intra-abdominal bleeding using normal saline irrigation: report of a case
- Author
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Yu-Chung Chang
- Subjects
Embryology ,medicine.medical_specialty ,business.industry ,Saline irrigation ,Incision wound ,medicine.medical_treatment ,Fistula ,Cell Biology ,Pancreaticoduodenectomy ,University hospital ,medicine.disease ,Reconstruction method ,Surgery ,Bile flow ,Anesthesia ,Medicine ,Anatomy ,business ,Saline ,Developmental Biology - Abstract
Figure 1. A biliary diversion reconstruction method for a pancreaticoduodenectomy. This method diverts the bile flow using an independent, looped jejunal segment to prevent bile from activating pancreatic juice. Normal saline is being instilled via a nasogastric tube from the incisional wound fistula above the pancreaticojejunostomy for the pancreaticojejunostomy leakage induced intra-abdominal bleeding. Stopping pancreaticoduodenectomy-leakage-induced intractable intra-abdominal bleeding using normal saline irrigation: report of a case Yu-Chung Chang (changmdphd at yahoo dot com)Department of Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University; Department of Surgery, Chung Shan Medical University Hospital, College of Medicine, Chung Shan Medical University, Taiwan Background : Intra-abdominal bleeding induced by a pancreaticojejunostomy (PJ) leakage after a pancreaticoduodenectomy (PD) is a lethal crisis. Transarterial embolization, endovascular stenting, and re-exploration are the standard treatments but have a high risk of mortality. No literature has been mentioned about the role of normal saline irrigation.
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- 2014
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36. Clinicopathologic Correlation of Serum Tissue Polypeptide Specific Antigen in Hepatocellular Carcinoma
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Shan Tair Wang, Dom Gene Tu, Nan Haw Chow, Pin Wen Lin, Ting-Tsung Chang, Nan Tsing Chiu, Yu-Chung Chang, and Wei Jen Yao
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Adult ,Male ,Clinicopathologic correlation ,Cancer Research ,Pathology ,medicine.medical_specialty ,Carcinoma, Hepatocellular ,Asian People ,Predictive Value of Tests ,Biomarkers, Tumor ,medicine ,Humans ,Neoplasm Invasiveness ,Clinical significance ,Aged ,Aged, 80 and over ,business.industry ,Cell growth ,Liver Diseases ,Liver Neoplasms ,General Medicine ,Middle Aged ,Prognosis ,medicine.disease ,Tissue Polypeptide Specific Antigen ,Oncology ,Hepatocellular carcinoma ,Female ,alpha-Fetoproteins ,Peptides ,business - Abstract
Objective: Recently, tissue polypeptide specific antigen (TPS) has been introduced as a cell proliferation marker. Little is known about its clinical significance in hepatocellular carcinoma (HCC). This study aimed to clarify serum TPS levels and tumor invasiveness of HCC. Methods: Serum TPS levels were determined with a monoclonal TPS IRMA assay in 69 patients with HCC. A correlation between serum TPS levels and clinical, biochemical, and pathological features was sought and compared with that of α-fetoprotein (AFP). In 57 healthy subjects, 56 patients with biopsy-proven chronic hepatitis and in 49 patients with liver cirrhosis, serum TPS levels were assayed and compared. Results: Serum TPS levels were significantly correlated with glutamic oxalacetic transaminase (p < 0.0001), glutamic pyruvic transaminase (p < 0.001), and lactate dehydrogenase (p = 0.027). There tended to be a positive relationship between serum TPS levels and tumor size, histological differentiation, capsular invasion, portal invasion, and clinical staging, although it did not reach statistical significance. A significant correlation, however, was observed between AFP and tumor size (p = 0.01), number (p = 0.042), histological grading (p = 0.028), portal invasion (p = 0.009), and clinical staging (p = 0.03). Patients with HCC had significantly higher TPS than healthy subjects (p < 0.001). However, there was substantial overlap between patients with HCC, chronic hepatitis, and liver cirrhosis. Conclusions: Our data suggest that serum TPS is not significantly related to tumor invasiveness in patients with HCC. Serum TPS levels are affected by the proliferative activity of the underlying chronic liver disease, which is frequently associated with HCC in Chinese patients. As a cell proliferation marker, serum TPS should be interpreted cautiously in the presence of chronic liver disease.
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- 2001
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37. Advances in Biomedical Research
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Hsu-Mei Hsu, Li-Ching Hsu, Yu-Chung Chang, Jin-Bau Fu, Kenneth S.S. Chang, Mei-Shang Ho, Kai-Ping N. Chow, Carlos Alberto Mandarim-de-Lacerda, Hong Chen, Francisco Borrego, Kang-Mai Wu, Chih-Feng Lu, Siu-Wah Chung, Cheng-Po Hu, Charles C. Y. Shih, John E. Coligan, Shwu-Fen Jiang, Wan-Jr Syu, Peter M. C. Wong, Rene Daniel, Leila Maria Meirelles Pereira, Ching-Gong Lin, Sung-Liang Yu, Shiang-Fen Huang, Hong-Sheng Kong, Jieh-Yuan Liou, Chungming Chang, Yi-Chien Mau, Ming F. Tam, Andrew G. Brooks, Phillip E. Posch, Guochuan Tsai, King-Song Jeng, Sheue-Rong Lin, June-Nam Seah, and Hwia-Cheng Ding
- Subjects
business.industry ,Endocrinology, Diabetes and Metabolism ,Biochemistry (medical) ,Clinical Biochemistry ,Medicine ,Pharmacology (medical) ,Engineering ethics ,Cell Biology ,General Medicine ,business ,Molecular Biology ,Biomedicine - Published
- 1998
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38. The past and present of liver suture
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Yu-Chung Chang, Andrzej L. Komorowski, and Andriy Lukashenko
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Rupture ,medicine.medical_specialty ,Russia (Pre-1917) ,Sutures ,business.industry ,Suture Techniques ,History, 19th Century ,History, 20th Century ,History, 21st Century ,humanities ,Hemostasis, Surgical ,Resection ,Surgery ,Suture (anatomy) ,Liver ,medicine ,Hepatectomy ,Humans ,Poland ,business ,Liver parenchyma - Abstract
Since the first attempts at resecting parts of diseased livers in the late nineteenth century, hemorrhage has been the main obstacle for surgeons. One of the first hemostasis techniques in liver resection was liver suture. The idea of suturing the liver in order to perform resection was proposed by a team of Russian and Polish surgeons from Kharkiv University in today’s Ukraine. The liver suture became widely popular and has been used in various forms throughout the surgical world. Further into the twentieth century, it has lost much of its popularity; however, over more than 100 years of existence it has seen several peaks in interest. Currently, it is still being used by some liver surgeons as it is one of the cheapest ways of obtaining a bloodless liver parenchyma transection.
- Published
- 2013
39. Will necrosectomy be an obsolete procedure for the management of infected necrotizing pancreatitis?
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Yu-Chung Chang
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medicine.medical_specialty ,Hepatology ,business.industry ,Endocrinology, Diabetes and Metabolism ,Gastroenterology ,Medicine ,Necrotizing pancreatitis ,business ,Surgery - Published
- 2016
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40. Repeated Hepatic Dearterialization for Unresectable Liver Metastases From Gastric Cancer: Review of Five Cases
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Naofumi Nagasue, Yoshinari Makino, Teruhisa Nakamura, Masaaki Uchida, Yoshinari Takemoto, Yu-Chung Chang, Hiroyuki Taniura, Akira Yamanoi, Takeo Kimoto, and Hitoshi Kohno
- Subjects
Male ,Reoperation ,medicine.medical_specialty ,medicine.medical_treatment ,lcsh:Surgery ,Gastroenterology ,Carcinoembryonic antigen ,Hepatic Artery ,Gastrectomy ,Stomach Neoplasms ,Internal medicine ,medicine ,Humans ,lcsh:RC799-869 ,Lymph node ,Ligation ,Aged ,Chemotherapy ,Hepatology ,biology ,business.industry ,Liver Neoplasms ,Cancer ,lcsh:RD1-811 ,Middle Aged ,medicine.disease ,Combined Modality Therapy ,Surgery ,Dissection ,medicine.anatomical_structure ,biology.protein ,Female ,lcsh:Diseases of the digestive system. Gastroenterology ,business ,Artery ,Research Article ,Liver Circulation - Abstract
A novel method of repeated hepatic dearterialization was evaluated in five patients with multiple metastases from gastric cancer in both hepatic lobes. After gastrectomy with extensive lymph node dissection (R2/3), all patients underwent implantation of a vascular occluder around the hepatic artery. Cannulation of the hepatic artery was added for later chemotherapy. The hepatic artery was occluded repeatedly for 1 hour twice daily in combination with intrahepatic infusion of anticancer drugs for as long as possible. Three of five patients demonstrated marked tumour regression with unexpectedly long survival (16 months in two patients and one still alive at 15 months). Carcinoembryonic antigen (CEA) levels decreased to almost normal in four patients who had initially high levels. The present experiences seems to indicate that long survival can be hoped for in patients with advanced gastric cancer with unresectable liver metastases.
- Published
- 1995
41. Visibility enhancement of common bile duct for laparoscopic cholecystectomy by vivid fiber-optic indication: a porcine experiment trial
- Author
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Yu Chung Chang, Tsung Chih Yu, Hsing Ying Lin, Chen Han Huang, Chih Han Chang, Hsiang-Chen Chui, and Shannon Shy
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medicine.medical_specialty ,Common bile duct ,Bile duct ,business.industry ,medicine.medical_treatment ,High mortality ,Optical density ,digestive system ,Atomic and Molecular Physics, and Optics ,digestive system diseases ,Surgery ,Catheter ,ocis:(170.1610) Clinical applications ,medicine.anatomical_structure ,surgical procedures, operative ,Laparotomy ,ocis:(170.2680) Gastrointestinal ,medicine ,Iatrogenic complication ,business ,Laparoscopic cholecystectomy ,Endoscopes, Catheters and Micro-Optics ,ocis:(170.2945) Illumination design ,Biotechnology - Abstract
Bile duct injury (BDI) is the most serious iatrogenic complication during laparoscopic cholecystectomy (LC) and occurs easily in inexperienced surgeons since the position of common bile duct (CBD) and its related ductal junctions are hard to precisely identify in the hepatic anatomy during surgery. BDI can be devastating, leading to chronic morbidity, high mortality, and prolonged hospitalization. In addition, it is the most frequent injury resulting in litigation and the most likely injury associated with a successful medical malpractice claim against surgeons. This study introduces a novel method for conveniently and rapidly indicating the anatomical location of CBD during LC by the direct fiber-optic illumination of 532-nm diode-pumped solid state laser through a microstructured plastic optical fiber to avoid the wrong identification of CBD and the injury from mistakenly cutting the CBD that can lead to permanent and even life threatening consequences. Six porcine were used for preliminary intra-CBD illumination experiments via laparotomy and direct duodenal incision to insert the invented CBD illumination laser catheter with nonharmful but satisfactory visual optical density.
- Published
- 2012
42. Picoliter-volume glucose concentration microsensor based on miniature abrupt-tapered Mach-Zehnder-interferometer
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Tsung-Hsun Yang, Yi Ning Chen, Nan-Kuang Chen, Zhi Zheng Feng, and Yu Chung Chang
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Materials science ,business.industry ,Trapping ,Cladding (fiber optics) ,Mach–Zehnder interferometer ,Laser ,Graded-index fiber ,law.invention ,Wavelength ,Optics ,law ,Optoelectronics ,Irradiation ,business ,Refractive index - Abstract
We report an ultracompact Mach-Zehnder index sensor with a device length of 438.6 μm using two micro-abrupt-tapers in a cladding-reduced strongly-guiding fiber based on a focused CO 2 laser beam. The cladding of strongly-guiding fiber is chemically etched before irradiated by a focused CO 2 laser beam. The index sensitivity is 600 nm/refractive index unit respectively at around 1.37 μm wavelength with a volume of 31.2 picoliter optical liquid trapping at one micro-abrupt-taper. A 72 picoliter glucose liquid with concentration of 200 mg/dL can lead to a red-shift of 0.8 nm at 1.3 μm.
- Published
- 2012
- Full Text
- View/download PDF
43. Open Hepatic Transection Using Chang’s Needle
- Author
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Yu-Chung Chang
- Subjects
medicine.medical_specialty ,Cirrhotic liver ,business.industry ,medicine.medical_treatment ,Tumor resection ,Ischemia ,medicine.disease ,Inferior vena cava ,Surgery ,medicine.vein ,Liver tissue ,cardiovascular system ,medicine ,business ,Medical expenses ,Reduction (orthopedic surgery) ,Liver parenchyma - Abstract
Chang’s needle is a long needle for sewing the entire thickness of the liver tissue in one row using intermittent mattress sutures. In this fashion, all the intrahepatic inflows and backflows can be secured without using the traditional Pringle’s maneuver before starting a liver parenchyma transection. Alternatively, it can be applied to any specified regional inflows and backflows (Chang’s maneuver), under ultrasonographic guidance as well, for small tumor resection and to localize or minimize ischemia and reperfusion in the target area. When compared with Pringle’s maneuver or other kinds of inflow control, use of Chang’s maneuver allows maximal reduction of ischemic and reperfusion injuries, which will be beneficial to an already taxed cirrhotic liver. A straight needle cannot be used for tumors near or over the inferior vena cava. Currently, a curved needle is being developed to overcome such problems, as well as to secure inflow and backflow before laparoscopic liver transection. The advantages of using Chang’s needle for Chang’s maneuver are that it is simple and inexpensive, causes fewer hemorrhages and fewer ischemic and reperfusion injuries, requires less training, and incurs lower medical expenses.
- Published
- 2012
- Full Text
- View/download PDF
44. The Impact of Introducing Therapeutic Robots in Hospital’s Organization
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Cecilio Angulo, Cecilia Yu Chung Chang, Marta Díaz, Universitat Politècnica de Catalunya. Departament d'Organització d'Empreses, Universitat Politècnica de Catalunya. Departament d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial, and Universitat Politècnica de Catalunya. GREC - Grup de Recerca en Enginyeria del Coneixement
- Subjects
Robòtica ,Process management ,Process (engineering) ,Technological change ,business.industry ,Robotics ,Empirical research ,Work (electrical) ,Technology -- Social aspects ,Robot ,In patient ,Health organization ,Artificial intelligence ,Informàtica::Robòtica [Àrees temàtiques de la UPC] ,Psychology ,business ,Robots ,Ciències de la salut [Àrees temàtiques de la UPC] - Abstract
The introduction of robots in health and wellbeing services could mean a great improvement in patients’ life, but also implies a huge change in hospital’s organization. This work introduces a empirical study that investigates the factors influencing the process of adoption of robots in hospitals. Interviews have been completed in a health organization leading this change. Learned lessons lead to define a balance of facilitators and barriers that should help to apply the innovation. This process has been completed from Kotter’s leading change approach, since it would be the roadmap for the whole procedure.
- Published
- 2012
- Full Text
- View/download PDF
45. Fiber-optic two-photon fluorescence correlation spectroscopy for remote cell flow velocity measurements
- Author
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James R. Baker, Yu Chung Chang, Theodore B. Norris, Jing Yong Ye, and Thommey P. Thomas
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Flow visualization ,Brightness ,Optical fiber ,business.industry ,Chemistry ,Fluorescence correlation spectroscopy ,Signal ,law.invention ,Optics ,Flow (mathematics) ,Flow velocity ,law ,Fiber ,business - Abstract
We report the use of a sensitive double-clad fiber (DCF) probe for remote cell flow velocity measurement by the means of two-photon excited fluorescence correlation spectroscopy (FCS). The ability to measure the flow velocities of labeled cells in whole blood has been demonstrated. A flow velocity of as high as 40 cm/s has been measured. The theoretical lower limit is the self-diffusion of the cell, which is almost zero compared to typical body fluid flow. Owing to the unique feature of two-photon excitation, we can monitor multiple fluorescent markers simultaneously. Therefore, using high brightness nanoparticles to generate the reference signal, we can calibrate the real time flow velocity or even calculate the average size of the cells under measurement. The ability to conduct in vivo flow velocity measurement with single cell resolution using the fiber probe would provide a unique way for disease diagnosis or surveillance after treatment.
- Published
- 2010
- Full Text
- View/download PDF
46. Fiber-optic multiphoton flow cytometry in whole blood and in vivo
- Author
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Zhengyi Cao, Alina Kotlyar, Eric R. Tkaczyk, Theodore B. Norris, Thommey P. Thomas, James R. Baker, Jing Yong Ye, and Yu Chung Chang
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Biomedical Engineering ,Hemodynamics ,Green fluorescent protein ,Flow cytometry ,Biomaterials ,Mice ,Circulating tumor cell ,Optics ,In vivo ,medicine ,Animals ,Fiber Optic Technology ,Humans ,Whole blood ,medicine.diagnostic_test ,business.industry ,Chemistry ,Equipment Design ,Flow Cytometry ,Neoplastic Cells, Circulating ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Equipment Failure Analysis ,Microscopy, Fluorescence, Multiphoton ,Cell Tracking ,Biophysics ,business ,Preclinical imaging ,Ex vivo ,Research Papers: Sensing - Abstract
Circulating tumor cells in the bloodstream are sensitive indicators for metastasis and disease prognosis. Circulating cells have usually been monitored via extraction from blood, and more recently in vivo using free-space optics; however, long-term intravital monitoring of rare circulating cells remains a major challenge. We demonstrate the application of a two-photon-fluorescence optical fiber probe for the detection of cells in whole blood and in vivo. A double-clad fiber was used to enhance the detection sensitivity. Two-channel detection was employed to enable simultaneous measurement of multiple fluorescent markers. Because the fiber probe circumvents scattering and absorption from whole blood, the detected signal strength from fluorescent cells was found to be similar in phosphate-buffered saline (PBS) and in whole blood. The detection efficiency of cells labeled with the membrane-binding dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindoldicarbocyanine, 4-chlorobenzenesulfonate (DiD) was demonstrated to be the same in PBS and in whole blood. A high detection efficiency of green fluorescent protein (GFP)-expressing cells in whole blood was also demonstrated. To characterize in vivo detection, DiD-labeled untransfected and GFP-transfected cells were injected into live mice, and the cell circulation dynamics was monitored in real time. The detection efficiency of GFP-expressing cells in vivo was consistent with that observed ex vivo in whole blood.
- Published
- 2010
47. Correlation Spectroscopy of Third-Harmonic Generation by Single Nanorods
- Author
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Jing Yong Ye, Moussa N'Gom, Yu-Chung Chang, Ashish Agarwal, Nicholas Kotov, James R. Baker, and Theodore B. Norris
- Subjects
Materials science ,business.industry ,Optoelectronics ,Nonlinear optics ,Fluorescence cross-correlation spectroscopy ,Fluorescence correlation spectroscopy ,Nanorod ,business ,Spectroscopy ,Molecular physics ,Two-dimensional nuclear magnetic resonance spectroscopy ,Fluorescence spectroscopy ,Excitation - Abstract
We have observed third-harmonic generation by single nanorods in solution and investigated its excitation polarization dependence. Our findings demonstrate the possibility of using third-harmonic signals for correlation spectroscopy, in contrast to conventional fluorescence correlation spectroscopy.
- Published
- 2009
- Full Text
- View/download PDF
48. Fiber-optic Multiphoton in vivo Flow Cytometry
- Author
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Theodore B. Norris, Zhengyi Cao, Alina Kotlyar, James R. Baker, Yu Chung Chang, Jing Yong Ye, and Thommey P. Thomas
- Subjects
Optical fiber ,medicine.diagnostic_test ,business.industry ,Chemistry ,Molecular biophysics ,Fluorescence ,law.invention ,Flow cytometry ,Optics ,Circulating tumor cell ,law ,In vivo ,medicine ,Biophysics ,Fiber probe ,business ,Cytometry - Abstract
We demonstrate the use of a double-clad fiber probe to conduct two-photon excited flow cytometry in a live mouse. High detection efficiency of GFP-expressing cells is demonstrated, and the initial dynamics of injected circulating cells is observed.
- Published
- 2009
- Full Text
- View/download PDF
49. BENEFICIAL EFFECT OF CYCLOSPORINE PRETREATMENT IN CANINE LIVER ISCHEMIA ENZYMATIC AND ELECTRONMICROSCOPIC STUDIES
- Author
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Naofumi Nagasue, Takafumi Hayashi, Teruhisa Nakamura, Yu-Chung Chang, and Hitoshi Kohno
- Subjects
Male ,medicine.medical_specialty ,Pathology ,medicine.medical_treatment ,Serum albumin ,Ischemia ,Cyclosporins ,Liver transplantation ,Group A ,Group B ,chemistry.chemical_compound ,Dogs ,Lactate dehydrogenase ,Internal medicine ,medicine ,Animals ,Humans ,Aspartate Aminotransferases ,Serum Albumin ,Transplantation ,Chemotherapy ,biology ,business.industry ,Fissipedia ,Infant, Newborn ,beta-Galactosidase ,biology.organism_classification ,medicine.disease ,Microscopy, Electron ,Endocrinology ,Liver ,chemistry ,biology.protein ,Female ,business ,Glucosidases - Abstract
The effect of cyclosporine on hepatic ischemia was investigated. Hepatic ischemia was produced for 90 min in mongrel dogs. Experimental dogs were divided into three groups as follows: group A (control group), group B (CsA pretreatment group), group C (CsA posttreatment group). CsA was administered at a dose of 10 mg/kg body weight/day for 3 days in the pre- or postoperative period. Survival rates were 61.5% in group A, 84.6% in group B, and 30.8% in group C. Enzymatic activity such as aspartate aminotransferase and lactate dehydrogenase was highest in group C, lowest in group B, and intermediate in group A. Opposite results were obtained for serum albumin concentrations. The mechanisms of the effect was investigated using a 60-min hepatic ischemia model. Serum levels of beta-glucosidase and beta-galactosidase in group B were lower than those in group A and group C. Electronmicroscopic specimens taken at 16 h after 60-min hepatic ischemia demonstrated that the extent of ischemic injury was mildest in group B. The present study demonstrated a beneficial effect on hepatic ischemia of CsA administered for 3 days prior to the ischemia. One of the mechanisms for this beneficial effect could be the stabilization of lysosomal membranes. These results suggest that CsA should be administered to a donor before organ harvesting for liver transplantation because of this beneficial effect.
- Published
- 1991
- Full Text
- View/download PDF
50. alpha Fetoprotein producing early gastric cancer with liver metastasis: report of three cases
- Author
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Dhar Dipok Kumar, Naofumi Nagasue, Yu-Chung Chang, S Abe, Hitoshi Kohno, and Nakamura T
- Subjects
Male ,Pathology ,medicine.medical_specialty ,Adenocarcinoma ,Metastasis ,Stomach Neoplasms ,Gastric Hepatoid Adenocarcinoma ,Pancreatic cancer ,Biomarkers, Tumor ,Humans ,Medicine ,Aged ,business.industry ,Stomach ,Incidence (epidemiology) ,Liver Neoplasms ,Gastroenterology ,Middle Aged ,Prognosis ,medicine.disease ,Early Gastric Cancer ,medicine.anatomical_structure ,Lymphatic Metastasis ,Female ,alpha-Fetoproteins ,Lymph ,business ,Alpha-fetoprotein ,Research Article - Abstract
Three cases of alpha fetoprotein producing early gastric cancer are presented. Liver metastases occurred in all patients shortly after curative gastrectomy and all died within two years. The incidence of liver metastasis was significantly higher than that in alpha fetoprotein negative early gastric carcinoma (p less than 0.001). The incidences of lymph node metastasis and invasion in lymph vessels and veins were also substantially higher in this group of patients. Two radical hepatic resections, including extended right lobectomy, were performed on one patient but the tumour recurred immediately.
- Published
- 1991
- Full Text
- View/download PDF
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