22 results on '"Chih‐Jung Wu"'
Search Results
2. Patient‐reported motor chemotherapy‐induced peripheral neuropathy impacts function in advanced colorectal cancer survivors receiving chemotherapy: A cross‐sectional study
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Chia‐Fen Hsieh, Ya‐Ning Chan, Chih‐Jung Wu, Li‐Yu Yen, Yu‐Chi Chang, and Ya‐Jung Wang
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Research and Theory - Published
- 2023
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3. Trajectories of symptom severity predicts quality of life change in newly diagnosis lymphoma survivors: An initial study
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Chih‐Jung Wu, Yu‐Chi Chen, Li‐Yuan Bai, Tzeon‐Jye Chiou, Kuan‐Chia Lin, and Ya‐Jung Wang
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Male ,Oncology ,Lymphoma ,Quality of Life ,Humans ,Prospective Studies ,Survivors ,Middle Aged ,Fatigue - Abstract
This study aimed to explore the subgroups of symptom severity and impact of their trajectories on quality of life in lymphoma survivors.Secondary data were analysed from a prospective study with four-time measures: before treatment (T1), during treatment (T2), treatment completion (T3) and 10 weeks after treatment (T4). Data were analysed using descriptive statistics, group-based trajectory model and generalised estimation equation.Fifty nine of 61 participants completed three-time measure (mean age = 60.43 years, male-predominant). The changes in symptom severity over time were divided into two subgroups: slight-stable group (n = 54, 89%) and mild-fickle group (n = 7, 11%). Pain, tiredness and sleeping trouble were the predominant symptoms. The quality of life change in the slight-stable group was significantly better than that of the mild-fickle group (B = 13.35, SE = 3.53, p 0.001). The overall quality of life at T2, T3 and T4 was better than it was at T1.The different trajectories of symptom severity significantly influenced quality of life changes in lymphoma survivors. Healthcare providers must be aware that there is a group of lymphoma survivors with relatively severe symptoms when newly diagnosed, compared to the opposite. More attention must be paid to this group, in addition to providing in-time symptom management.
- Published
- 2022
4. Extremity Exercise Program in Breast Cancer Survivors Suffering from Chemotherapy-Induced Peripheral Neuropathy: A Feasibility Pilot Study
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Chih-Jung Wu, Ya-Ning Chan, Li-Yu Yen, Yun-Hen Chen, Chyi Lo, Ling-Ming Tseng, and Ya-Jung Wang
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Health Information Management ,Leadership and Management ,Health Policy ,Health Informatics ,extremity exercise program ,ten skilled hand exercise ,Buerger-Allen exercise ,chemotherapy induced peripheral neuropathy (CIPN) ,breast cancer survivors - Abstract
Objectives: To evaluate the feasibility of implementation of an extremity exercise program and to examine its preliminary effects in breast cancer survivors suffering from chemotherapy-induced peripheral neuropathy (CIPN). Sample & Setting: Thirteen breast cancer survivors from one hospital in northern Taiwan. Methods and Variables: A single group with repeated measures, and a quasi-experimental design. The intervention program was a four week, home-based extremity exercise program that was comprised of 10 skilled hand exercises and Buerger-Allen exercises. The Total Neuropathy Scale (clinical version), Functional Assessment of Cancer Therapy/Gynecologic Oncology Group, Neurotoxicity (13-Item Version), Identification Pain Questionnaire, and pain Visual Analogue Scale were used to measure CIPN before exercise (T1), during (T2~T4), and after exercise (T5). Qualitative data were also collected at each time point. Data were analyzed by using descriptive statistics, generalized estimating equations, and directed content analysis. Results: None of the participants reported adverse events during the study period. The extremity exercise program significantly improved patient-reported CIPN after intervention at T4 or T5 but was insignificant on clinician-assessed CIPN. The qualitative data of participant experience indicated that this program is feasible and easy to follow. Conclusion: The extremity exercise program is feasible but needs to increase the sample size and prolong the intervention period for confirmation.
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- 2022
5. Chemotherapy-induced peripheral neuropathy in newly diagnosed breast cancer survivors treated with taxane: a prospective longitudinal study
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Chih Jung Wu, Ya Jung Wang, Liang Chih Liu, Yi Fang Tsai, Ling Ming Tseng, Ming Wei Lin, Ya-Ning Chan, and You Wun Jheng
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Oncology ,Adult ,Bridged-Ring Compounds ,medicine.medical_specialty ,Longitudinal study ,medicine.medical_treatment ,Breast Neoplasms ,03 medical and health sciences ,0302 clinical medicine ,Breast cancer ,Cancer Survivors ,Internal medicine ,medicine ,Humans ,030212 general & internal medicine ,Longitudinal Studies ,Prospective Studies ,Aged ,Chemotherapy ,Taxane ,business.industry ,Cancer ,Peripheral Nervous System Diseases ,Middle Aged ,medicine.disease ,Peripheral neuropathy ,Chemotherapy-induced peripheral neuropathy ,030220 oncology & carcinogenesis ,Neuropathic pain ,Female ,Taxoids ,business - Abstract
This study aimed to prospectively explore severity and prevalence of chemotherapy-induced peripheral neuropathy (CIPN) and examine the correlation between clinician-assessed (objective) and patient-reported (subjective) CIPN in breast cancer survivors receiving taxane. This was a prospective, longitudinal study. Purposive sampling was adapted to enroll women newly diagnosed with breast cancer and about to receive taxane. The CIPN was assessed after breast cancer diagnosed and before chemotherapy (T1), before cycle 1 to 4 taxane infusion (T2 to T5), and after chemotherapy completion (T6 to T8). Total Neuropathy Score–clinical version (TNSc), Identification Pain Questionnaire (ID pain), Functional Assessment of Cancer Therapy–Taxane subscale (FACT-Tax), and Peripheral Neuropathy Scale (PNS) were utilized for measuring CIPN. Descriptive statistics, Pearson correlation coefficient, and generalized estimating equation were used to analyze data. A total of 88 participants were included. Both clinician-assessed and patient-reported CIPN gradually increased between T1 and T6 and mildly decreased at T7 and T8. Fifty-five participants (62.5%) experienced CIPN at T8. Weak-to-moderate correlations between subjective and objective CIPN were found at T6 to T8 (r = 0.272–0.533, p < 0.05). The change of TNSc, FACT-Tax, and PNS were significant over time. However, the significant change of neuropathic pain was only found at T6. The change of CIPN prevalence and severity were significant over time in survivors newly diagnosed with breast cancer. Specifically, the severest and highest CIPN was detected at chemotherapy completion. Survivors remained suffering from CIPN 3 months after chemotherapy completion. Besides, mild to moderate correlations between clinician-assessed and patient-reported CIPN were identified.
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- 2020
6. Exploring factors associated with quality of life in women undergoing mammography
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Chih Jung Wu, Ya-Jung Wang, and Liang-Chih Liu
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humanities - Abstract
Purpose: Mammography is broadly used in early detection of breast cancer. However, women undergoing mammography had experienced physical, psychological, and social disturbance; this could affect their Quality of Life (QoL). Only few studies in QoL have been done on cancer screening populations. The purpose of this study was to explore factors associated with QoL among women undergoing mammography. Methods: This research used a cross-sectional questionnaire survey and conducted with 158 women who were undergoing mammography. Data were collected from an outpatient department in a medical center located in central Taiwan from December 2014 to October 2015. The Functional Assessment of Cancer Therapy Scale –General, Chinese version was used to assess the QoL. Emotional distress was measured by using the Hospital Anxiety and Depression Scale and Mishel’s Uncertainty in Illness Scale. Descriptive statistic and multiple liner regression were used to analyze the data. Results: The multiple liner regression results revealed that women with benign breast tumors had better functional well-being (β = 1.276, p = 0.021). Women who had higher uncertainty (β=-0.216, p < 0.01) and emotional distress (β = -1.229, p < 0.01) experienced lower QoL. Conclusion: In this study, the uncertainty, emotional distress significantly predicted the QoL in women undergoing mammography screening. Clinical staff should pay attention to the emotional problems of women undergoing mammography. When women receive the mammography, this is an opportune time to educate them regarding the examination process and inform them of how reductions in uncertainty and emotional problems may help improve their QoL.
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- 2020
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7. Effectiveness of Multimedia-Based Learning on the Improvement of Knowledge, Attitude, and Behavioral Intention toward COVID-19 Prevention among Nurse Aides in Taiwan: A Parallel-Interventional Study
- Author
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Yi-Min Hsu, Ting-Shan Chang, Chien-Lun Chu, Shu-Wen Hung, Chih-Jung Wu, Tzu-Pei Yeh, and Jiun-Yi Wang
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Health Information Management ,COVID-19 ,multimedia-based learning ,nurse aides ,Leadership and Management ,Health Policy ,education ,Health Informatics - Abstract
Because nurse aides are one of the first-line care providers in hospitals, they should possess better knowledge, attitude, and behavioral intention toward COVID-19 during the pandemic. This study aimed to compare the improvements of COVID-19-related education on learning outcomes between multimedia-based and traditional face-to-face learning models for nurse aides. The parallel-group randomized controlled trial recruited 74 participants in both the experimental and control groups. Two 90 min interventions with the same contents, but in different ways, were delivered. A structured questionnaire was used to collect data of demographic information, knowledge, attitude, and behavioral intention toward COVID-19 before and after the interventions. Results from generalized estimation equations analysis indicated that the nurse aides in the multimedia-based learning group had greater improvement in the scores of knowledge (difference in change: 3.2, standard error: 0.97, p < 0.001), attitude (difference in change: 10.2, standard error: 2.97, p < 0.001), and behavioral intention (difference in change: 0.5, standard error: 0.04, p < 0.001) than those in the face-to-face learning group. During the outbreak of COVID-19, multimedia-based learning as an effective learning method could improve the learning outcomes related to COVID-19 and achieve learning goals without close contact.
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- 2022
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8. Effects of diet nutritional quality on the growth and grazing of Noctiluca scintillans
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Chih-Jung Wu, Shuwen Zhang, Bingzhang Chen, and Hongbin Liu
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Elemental composition ,Ecology ,biology ,Numerical response ,Noctiluca scintillans ,Grazing ,Functional response ,Nutritional quality ,Aquatic Science ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics - Published
- 2015
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9. Role of microzooplankton grazing in regulating phytoplankton biomass and community structure in response to atmospheric aerosol input
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Cui Guo, Chih-Jung Wu, Hongbin Liu, Jian Zhen Yu, and Shuwen Zhang
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Oceanography ,Ecology ,Grazing ,Phytoplankton community structure ,Community structure ,Environmental science ,Aquatic Science ,Ecology, Evolution, Behavior and Systematics ,Aerosol ,Phytoplankton biomass - Published
- 2014
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10. Fabrication of positively charged catanionic vesicles from ion pair amphiphile with double-chained cationic surfactant
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Chih Jung Wu, Chien Hsiang Chang, An-Tsung Kuo, Yu Min Yang, and Chen Hsuan Lee
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chemistry.chemical_classification ,Polymers and Plastics ,Chemistry ,Bilayer ,Vesicle ,Cationic polymerization ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Pulmonary surfactant ,Chemical engineering ,Bromide ,Amphiphile ,Materials Chemistry ,Zeta potential ,Organic chemistry ,Physical and Theoretical Chemistry ,Alkyl - Abstract
In this study, a pseudodouble-chained ion pair amphiphile, hexadecyltrimethylammonium-dodecylsulfate (HTMA-DS), was prepared from a mixture of cationic surfactant, hexadecyltrimethylammonium bromide, and anionic surfactant, sodium dodecylsulfate. Positively charged catanionic vesicles were then successfully fabricated from HTMA-DS with the addition of cationic surfactants, dialkyldimethylammonium bromide (DXDAB), including ditetradecyldimethylammonium bromide (DTDAB), dihexadecyldimethylammonium bromide, and dioctadecyldimethylammonium bromide (DODAB), with a mechanical disruption approach. The control of charge characteristic and physical stability of the catanionic vesicles through the variations of DXDAB molar fraction and alkyl chain length was then explored by size, zeta potential, and Fourier transform infrared analyses. It was found that the molecular packing and/or molecular interaction of HTMA-DS with DXDAB rather than the electrostatic repulsion between the charged vesicles dominated the physical stability of the mixed HTMA-DS/DXDAB vesicles. The presence of DTDAB, which possesses short alkyl chains, could adjust the packing of the unmatched chains of HTMA+ and DS− and promote the vesicle formation. However, the weak molecular interaction due to the short chains of DTDA+ could not maintain the vesicle structures in long-term storage. With increasing the alkyl chain length of DXDAB, it was possible to improve the vesicle physical stability through the enhanced molecular interaction in the vesicular bilayer. However, the long alkyl chains of DODAB unmatched with those of HTMA-DS, resulting in the vesicle disintegration in long-term storage. For the formation of stable charged catanionic vesicles of HTMA-DS/DXDAB, a good match in hydrophobic chains and strong molecular interaction were preferred for the vesicle-forming molecules.
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- 2013
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11. Population dynamics of Noctiluca scintillans during a bloom in a semi-enclosed bay in Hong Kong
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Shuwen Zhang, Hongbin Liu, Hiu Suet Kung, Cui Guo, Shuqun Song, Paul Harrison, Wing Keung Lau, Chih-Jung Wu, Mianrun Chen, and Jie Xu
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0106 biological sciences ,010504 meteorology & atmospheric sciences ,Red tide ,Harmful Algal Bloom ,Population ,Population Dynamics ,Aquatic Science ,Biology ,Oceanography ,01 natural sciences ,Phytoplankton ,education ,Picoplankton ,0105 earth and related environmental sciences ,Trophic level ,education.field_of_study ,Ecology ,010604 marine biology & hydrobiology ,Noctiluca scintillans ,Dinoflagellate ,biology.organism_classification ,Pollution ,Bays ,Dinoflagellida ,Hong Kong ,Bloom - Abstract
Noctiluca scintillans, a heterotrophic dinoflagellate responsible for most of the red tides in Hong Kong waters was investigated to determine the influence of biotic and abiotic factors in determining its population dynamics. N. scintillans first occurred in January when temperature was ~17°C, and reached a maximum of 1980cellsL-1 one month later. N. scintillans interacted with trophic compartments from picoplankton to mesozooplankton, but its population development was largely related to the availability of phytoplankton, especially diatoms. Growth rates in microcosms (with mainly biological factors) ranged from -0.38 to 1.11d-1 and were similar to the field in situ growth rates (physical and biological factors). Thus, optimum hydrographical conditions (temperature and water stability), and a rich food supply were necessary for N. scintillans to bloom. Its spatial distribution pattern was a result of biological and physical coupling, but mainly controlled by physical accumulation processes such as winds, tides and currents.
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- 2016
12. Effect of the silica content of diatom prey on the production, decomposition and sinking of fecal pellets of the copepod Calanus sinicus
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Hongbin Liu and Chih-Jung Wu
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0106 biological sciences ,010504 meteorology & atmospheric sciences ,biology ,010604 marine biology & hydrobiology ,fungi ,Pellets ,Biogenic silica ,biology.organism_classification ,01 natural sciences ,Predation ,Diatom ,Animal science ,Thalassiosira weissflogii ,Botany ,Pellet ,Grazing ,Ecology, Evolution, Behavior and Systematics ,Copepod ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
The effects of changing the amount of silica in the cell wall of diatom prey, on the production, decomposition rate and sinking velocity of fecal pellets of the calanoid copepod, Calanus sinicus, were examined. Using different light intensities to control the growth of the diatom Thalassiosira weissflogii also led to the accumulation of different amounts of biogenic silica. Copepods were then fed with either low (~ 1600 cells L−1) or high (~ 8000 cells L−1) concentrations of this diatom. Copepods fed on a high concentration of diatoms with high silica content, exhibited a lower grazing rate and lower fecal pellet production rate than those fed on a high concentration of diatoms with low silica content. However, there was no difference in either the grazing or fecal pellet production rates at low prey concentrations with high or low silica content. The size of the fecal pellets produced was only affected by the prey concentration, and not by the silica content of prey. In addition, the degradation rate of the fecal pellets was much higher for copepods fed a low-silica diet than for those fed on a high-silica diet. Significantly lower densities and sinking rates only occurred in the fecal pellets of copepods fed a low-silica diet and a low prey concentration. Calculating the L-ratio (the ratio of degradation rate:sinking rate) for each group indicated that the fecal pellets produced by copepods fed on highly silicified diatoms are likely to transport both biogenic silica and organic carbon to the deep layer; whereas those produced following the consumption of low-silica diatoms are likely to decompose in the mixing layer.
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- 2016
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13. Does the Mesh Size of the Plankton Net Affect the Result of Statistical Analyses of the Relationship Between the Copepod Community and Water Masses?
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Chih-Jung Wu, Chun-Ming Shin, and Kuo-Ping Chiang
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Fishery ,Carcinology ,Water mass ,biology ,Abundance (ecology) ,Statistical analyses ,Species evenness ,Animal Science and Zoology ,Species richness ,Aquatic Science ,Plankton ,biology.organism_classification ,Copepod - Abstract
We examined if the results of statistical analyses of the relationship between copepod communities and water masses would be affected by the mesh size of the plankton net, by comparing abundance and species composition of copepods in plankton samples collected by plankton nets of different mesh sizes. Our samples were collected during the summer of 2006 in the East China Sea (ECS) by plankton nets with mesh sizes of 100 and 330 μm. The abundance of copepods collected by the 100 μm-mesh plankton net was about two orders of magnitude higher than that collected by the 330 μm-mesh plankton net. The difference in abundance was mainly due to the loss of small-sized copepods in the samples collected by the plankton net with the larger mesh. Species richness was higher in samples collected by the 100 μm-mesh net and Piélou's evenness was generally higher in samples collected by the 330 μm-mesh net. Although species composition of copepods varied in samples collected by plankton nets with different mesh sizes, the statistical analysis of the relationship between the copepod community and the water masses in these samples appeared not to be affected.
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- 2011
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14. Diel feeding pattern and prey selection of mesozooplankton on microplankton community
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Chih-Jung Wu, Hongbin Liu, and Kuo-Ping Chiang
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Ecology ,Abundance (ecology) ,Grazing ,Aquatic Science ,Biology ,Feeding patterns ,Diel vertical migration ,Ecology, Evolution, Behavior and Systematics ,Predation ,China sea ,Trophic level - Abstract
Mesozooplankton play an important role in transporting energy from microphytoplankton and microzooplankton to higher trophic levels. However there were few studies on the diel feeding patterns and prey selectivity of mesozooplankton. We conducted feeding experiments of mesozooplankton in the East China Sea to determine their respective diel feeding patterns on diatoms, ciliates and dinoflagellates, and to assess the contribution of these prey items to mesozooplankton diet. The results showed higher mesozooplankton grazing rates on ciliates and dinoflagellates than on diatoms at the day time, and the opposite pattern at the night time. A significant prey selection was observed, in which mesozooplankton positively selected ciliates and dinoflagellates during day and diatoms at night. The different grazing reactions of mesozooplankton toward each prey item might be related to the mobility of the prey. In all, microzooplankton (ciliates and dinoflagellates) provided the majority of the mesozooplankton carbon ingestion, even at a station dominated by small pennate diatoms. In particular, dinoflagellates are an important prey of mesozooplankton in the East China Sea and their contribution to the diet of mesozooplankton is unproportionate to their abundance.
- Published
- 2010
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15. A Combined Cavity with Improved Performance under Simultaneous Resonance of Sub-cavities
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Chih Jung Wu, Chung Ping Liu, Zhengbiao Ouyang, Jong C. Wang, and Qiang Liu
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Materials science ,business.industry ,Scattering ,Finite-difference time-domain method ,Resonance ,Dielectric ,law.invention ,Longitudinal mode ,Optics ,Quality (physics) ,law ,Optical cavity ,business ,Microwave cavity - Abstract
We insert a dielectric rod in the point cavity or increase the volume of the point cavity in the combined system to shift the resonant frequency of the point cavity to be the same as that of the feedback cavity. These systems are advantageous over our previous design in that the feedback cavity is uniform and no stray scattering exists in the cavity. Simulations through flnite-difierence time-domain (FDTD) method demonstrate that, in double resonance, the maximum quality factor of the new structure is promoted by 34.7%, and the maximum localized fleld intensity in the point defect cavity is promoted by 314% over that in the earlier structure.
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- 2010
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16. Flow cytometric characterization of interactions between U-937 human macrophages and positively charged catanionic vesicles
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Chien Hsiang Chang, Yi Lin Lin, Chih Jung Wu, and Jung hua Steven Kuo
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Time Factors ,Cell Survival ,Population ,Cell Culture Techniques ,Apoptosis ,Biology ,Colloid and Surface Chemistry ,Superoxides ,Cations ,Cell Line, Tumor ,Humans ,Cationic liposome ,Physical and Theoretical Chemistry ,education ,Cell Size ,Fluorescent Dyes ,Membrane Potential, Mitochondrial ,chemistry.chemical_classification ,Membrane potential ,Reactive oxygen species ,Liposome ,education.field_of_study ,Formazans ,Dose-Response Relationship, Drug ,Macrophages ,Vesicle ,Cell Cycle ,G1 Phase ,Hydrogen Peroxide ,Surfaces and Interfaces ,General Medicine ,Mononuclear phagocyte system ,Flow Cytometry ,Mitochondria ,Phenanthridines ,Kinetics ,chemistry ,Biochemistry ,Liposomes ,Biophysics ,Indicators and Reagents ,Lymphoma, Large B-Cell, Diffuse ,Reactive Oxygen Species ,Intracellular ,Biotechnology - Abstract
Catanionic vesicles are considered a potential alternative to liposomes for drug delivery systems because of their greater stability and lower cost. Before using catanionic vesicles in vivo, their interactions with macrophages must be fully understood because they are primarily removed from circulation by the macrophages of the mononuclear phagocyte system. Using flow cytometry, we examined the intracellular responses—reactive oxygen species (ROS) content, mitochondrial membrane potential, cell size and complexity, and cell cycle profiles—in U-937 human macrophages treated with positively charged catanionic vesicles. Kinetic hydrogen peroxide production initially increased at lower concentrations (4–10 nM) but declined at higher concentrations (40 nM and 80 nM) over the entire incubation period. Superoxide content generation, however, increased over the entire concentration range and incubation period. Catanionic vesicles decreased mitochondrial membrane potential for every concentration after 4 h of incubation but caused a significant fluctuation in mitochondrial membrane potential at 6 h. After 6 h of incubation, catanionic vesicles produced more changes in cell size and complexity than after 4 h. The increase in the subG1 population of cells treated with catanionic vesicles at higher doses indicated that apoptosis progressed. Positively charged catanionic vesicles induced different activated patterns of ROS generation and changes in mitochondrial membrane potential than did cationic liposomes. The nature of the interactions between macrophages and catanionic vesicles is of great importance for the design of safer and more effective delivery systems for macrophages. Our findings contribute to a better understanding of the molecular action of catanionic vesicles in the cellular system.
- Published
- 2008
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17. Photonic quantum-well structures containing negative-index materials
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Chih Jung Wu, Chun Xu, Xiaohan Liu, Chung Ping Liu, Dezhuan Han, and Xiaochuang Xu
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Quantum optics ,Materials science ,business.industry ,Physics::Optics ,Optical polarization ,Polarization (waves) ,Yablonovite ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Photonic metamaterial ,Optics ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Photonics ,business ,Quantum well ,Photonic crystal - Abstract
The properties of photonic quantum-well structures containing negative-index materials are studied theoretically, showing features remarkably better than conventional photonic quantum-well structures. Owning to the zero- n ¯ gap of one-dimensional photonic crystals containing negative-index materials, the photonic quantum-well structures can be proposed as a multiple channeled filter which is very weak dependent on incident angle and polarization, and insensitive to the thickness disorder of the barrier photonic crystals.
- Published
- 2007
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18. A photonic-crystal polarizer integrated with the functions of narrow bandpass and narrow transmission-angle filtering
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Zhengbiao Ouyang, Depeng Mao, Chung Ping Liu, Jong C. Wang, and Chih Jung Wu
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Materials science ,Physics and Astronomy (miscellaneous) ,business.industry ,General Engineering ,Physics::Optics ,General Physics and Astronomy ,Dielectric ,Filter (signal processing) ,Polarizer ,Polarization (waves) ,law.invention ,Optics ,Band-pass filter ,law ,Optical filter ,business ,Anisotropy ,Photonic crystal - Abstract
Through the transfer matrix method, we demonstrated a special polarizer integrated with the functions of narrow bandpass (NBP) and narrow transmission-angle (NTA) filtering at normal incidence in a stack of two one-dimensional defective photonic crystals (PCs). One of the PCs is made of an isotropic dielectric media, while the other PC is made of anisotropic media. The key point in designing the stack is to set the central frequencies of the defect modes of the two sub-PCs to be the same for one polarization at normal incidence, but different for oblique incidence or for other polarizations, so that the stack structure could have the functions of three elements: a polarizer, an NBP filter, and an NTA filter.
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- 2007
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19. FLAT PASS-BANDS OF ONE-DIMENSIONAL PHOTONIC CRYSTALS COMPOSED OF MULTIPLE QUANTUM WELLS WITH GAUSSIAN-DISTRIBUTED REFRACTIVE INDICES
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Kang Huai Liu, Ben Yuan Gu, Guo Jang Huang, Chung Ping Liu, and Chih Jung Wu
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Fabrication ,Materials science ,business.industry ,Superlattice ,Gaussian ,Spectrum (functional analysis) ,Physics::Optics ,Statistical and Nonlinear Physics ,Condensed Matter Physics ,symbols.namesake ,Optics ,Transmission (telecommunications) ,symbols ,Optical filter ,business ,Refractive index ,Photonic crystal - Abstract
Transmissions of one-dimensional (1D) photonic crystals (PCs) containing multiple quantum wells with Gaussian-distributed refractive indices are calculated with the use of the transfer-matrix method. The transmission spectrum of this kind of structures exhibits flatted pass-bands. The resonant peaks in the transmission spectrum of the conventional 1D PCs have been significantly suppressed. It is expected that this kind of structures may favor the fabrication of optical filters in applications to micro-optical devices.
- Published
- 2006
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20. Compact and low-power optical logic NOT gate based on photonic crystal waveguides without optical amplifiers and nonlinear materials
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Zhengbiao Ouyang, Chung Ping Liu, and Chih Jung Wu
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Optical amplifier ,Physics ,business.industry ,Photonic integrated circuit ,Optical computing ,Optical performance monitoring ,Atomic and Molecular Physics, and Optics ,Optics ,Optical transistor ,Inverter ,Optoelectronics ,Contrast ratio ,Electrical and Electronic Engineering ,business ,Engineering (miscellaneous) ,Photonic crystal - Abstract
An optical logic NOT gate (OLNG) is presented based on photonic crystal (PhC) waveguides without nonlinear materials and optical amplifiers. Also, a way of determining the operating parameters is presented. It is demonstrated through finite-difference time-domain simulations that the structure presented can operate as an OLNG. The optimized contrast ratio, defined as the logic-“1” output power divided by the logic-“0” output power, is found to be 297.07 or 24.73 dB. The size of the OLNG can be as small as 7a×7a, where a is the lattice constant of the PhC. Further, the OLNG presented in this paper can operate at a bit rate as high as 2.155 Tbit/s, which is much higher than that of electronic or optical logic gates developed until now. Moreover, as it is not based on the nonlinear effect, the OLNG can operate at very low powers and a relatively large operating bandwidth. This is favorable for large-scale optical integration and for developing multiwavelength parallel-processing optical logic systems.
- Published
- 2012
21. All-optical half adder based on cross structures in two-dimensional photonic crystals
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Chih Jung Wu, Chung Ping Liu, Zhengbiao Ouyang, Jong C. Wang, and Qiang Liu
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Digital electronics ,Physics ,Adder ,Photons ,business.industry ,Photonic integrated circuit ,Finite-difference time-domain method ,Optical Devices ,Signal Processing, Computer-Assisted ,Equipment Design ,Topology ,Atomic and Molecular Physics, and Optics ,Equipment Failure Analysis ,Optics ,Logic gate ,Photonics ,business ,Photonic crystal ,Electronic circuit - Abstract
We propose an all-optical half adder based on two different cross structures in two-dimensional photonic crystals. One cross structure contains nonlinear materials and functions as an "AND" logic gate. The other one only contains linear materials and acts as an "XOR" logic gate. The system is demonstrated numerically by the FDTD method to work as expected. The optimal operating speed without considering the response time of the nonlinear material, the least ON to OFF logic-level contrast ratio, and the minimum power for this half adder obtained were 0.91 Tbps, 16 dB and 436 mW, respectively. The proposed structure has the potential to be used for constructing all-optical integrated digital computing circuits.
- Published
- 2009
22. A combined cavity for high sensitivity THz signal detection
- Author
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Zhengbiao Ouyang, Xianda Luo, Chih Jung Wu, Jong C. Wang, and Chung Ping Liu
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Physics ,Resonator ,Waveguide (electromagnetism) ,Optics ,business.industry ,Terahertz radiation ,Physics::Optics ,Resonance ,Detection theory ,Photonics ,business ,Sensitivity (electronics) ,Signal - Abstract
Detection of signals in the THz frequency region is important for applications of THz waves in many areas, such as in medical imaging, forbidden-combined sensing, weapon monitoring, and wireless communications. Cooling system operating under very low temperature, for eliminating the unwanted background THz radiation that exists everywhere in room temperature, sets an obstacle for applications of conventional THz signal detecting systems. We present a combined cavity that can pick out the useful signal in high sensitivity, while the influence of the background THz radiation can be neglected in the detection. The combined cavity consists of a point-defect photonic-crystal resonator and a photonic-crystal WGR. The two resonators are coupled together through optical tunneling to form the combined cavity. Under proper operating parameters, the two resonators are in simultaneous resonance, and the field intensity in the point-defect resonator can be thousands of times of that of an incoming THz signal for a given frequency, so that the sensitivity of detection can be very high. Since the background THz radiation is not in resonance with the cavity, the influence of it to the detection of THz signals wanted can be neglected, and thus cooling systems can be omitted. Plane wave expansion method is used to determine the resonance wavelengths and mode patterns of the cavity. Finite-difference- time-domain method is used to find the quality factors and to simulate the resonance process. Parameter optimization and the conditions for simultaneous resonance of the two cavities are studied.
- Published
- 2007
- Full Text
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