Browsing by Author "Chen, Shean-Jen"

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3D surface morphology imaging of opaque microstructures via light-field microscopy
(2018-07-12)
Da Sie, Yong
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Lin, Chun-Yu
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Chen, Shean-Jen
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光電學院
;
College of Photonics
Observing dynamic micro-scale phenomena occurring at millisecond time scales, such as organism activity, micron particle flows, or any opaque object observation, requires volumetric microscopy techniques able to achieve high data acquisition rates while maintaining contrast so that measurement of fine micro-scale features is possible. In realizing this purpose, the light-field (LF) technique has already been used on three-dimensional (3D) scene capturing and even for microscopic visualizations. In studying the ability and feasibility of 3D surface morphology reconstruction via LF microscopy, we adopted a lab-made LF microscope and integrated a four-dimensional Fourier slice algorithm and a Markov random field propagation algorithm. Furthermore, for numerical comparison and quantized analysis, the Tenengrad function was utilized to calculate the average contrast of the region of interest. Reflective US Air Force targets and 3D photolithography-made micro-scaffolds coated with 50 nm nickel thin films were adopted for system alignment and calibration. The experimental results demonstrate that the developed LF microscope with the signal processing algorithms can observe the 3D surface morphology of opaque microstructures with one snapshot, and has been preliminary applied to Brownian motion observation with 30 Hz volumetric image rate.
A Hydrolyzed Chicken Extract CMI-168 Enhances Learning and Memory in Middle-Aged Mice
(2019-01-01)
Tsai, Sheng-Feng
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Chang, Chia-Yuan
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Yong, Shan-May
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Lim, Ai-Lin
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Nakao, Yoshihiro
There has been increasing evidence that consumption of dietary supplements or specific nutrients can influence cognitive processes and emotions. A proprietary chicken meat extraction, Chicken Meat Ingredient-168 (CMI-168), has previously been shown to enhance cognitive function in humans. However, the mechanism underlying the CMI-168-induced benefits remains unclear. In this study, we investigated the effects of CMI-168 on hippocampal neuroplasticity and memory function in middle-aged (9-12 months old) mice. The mice in the test group (termed the "CMI-168 group") were fed dietary pellets produced by mixing CMI-168 and normal laboratory mouse chow to provide a daily CMI-168 dose of 150 mg/kg of body weight for 6 weeks. The control mice (termed the "Chow group") were fed normal laboratory mouse chow pellets. CMI-168 supplementation did not affect the body weight gain, food intake, or exploratory behavior of the mice. In the novel object recognition test, the CMI-168 group showed better hippocampus-related non-spatial memory compared to the control Chow group. However, spatial memory examined by the Morris Water Maze test was similar between the two groups. There was also no significant difference in the induction and maintenance of long-term potentiation and dendritic complexity of the hippocampal cornu ammonis region 1 (CA1) neurons, as well as the levels of neuroplasticity-related proteins in the hippocampi of the CMI-168 and Chow groups. Interestingly, we observed that CMI-168 appeared to protect the mice against stress-induced weight loss. In conclusion, dietary supplementation of CMI-168 was found to improve learning and memory in middle-aged mice, independent of structural or functional changes in the hippocampus. The resilience to stress afforded by CMI-168 warrants further investigation.
Fast and improved bioimaging via temporal focusing multiphoton excitation microscopy with binary digital-micromirror-device holography
(2018-11-01)
Sie, Yong Da
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Chang, Chia-Yuan
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Lin, Chun-Yu
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Chang, Nan-Shan
;
Campagnola, Paul J.
Conventional temporal focusing-based multiphoton excitation microscopy (TFMPEM) can offer wide-field optical sectioning with an axial excitation confinement of a few microns. To improve the axial confinement of TFMPEM, a binary computer-generated Fourier hologram (CGFH) via a digital-micromirror-device (DMD) was implemented to intrinsically improve the axial confinement by filling the back-focal aperture of the objective lens. Experimental results show that the excitation focal volume can be condensed and the axial confinement improved about 24% according to the DMD holography. In addition, pseudouniform MPE can be achieved using two complementary CGFHs with rapid pulse-width modulation switching via the DMD. Furthermore, bioimaging of CV-1 in origin with SV40 genes-7 cells demonstrates that the TFMPEM with binary DMD holography can improve image quality by enhancing axial excitation confinement and rejecting out-of-focus excitation. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)
Graphene oxide dot-based microstructures via dispersion and support of bovine serum albumin
(2016-10-01)
Chang, Hsin-Yu
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Lin, Chun-Yu
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Chang, Chia-Yuan
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Teng, Hsisheng
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Campagnola, Paul J.
Three-dimensional graphene oxide-based microstructures have great potential for use in microelectronic and biomedical applications and can be fabricated by using two-photon excitation photochemical processes. In such excitation processes, rose Bengal is the preferred candidate as the photoactivator in two-photon crosslinking; nevertheless, it induces graphene oxide self-aggregation. Herein, bovine serum albumin (BSA) is adopted to prevent graphene oxide dot (GOD) aggregation even at very high GOD fabrication-solution concentrations, yet still supports GOD microstructures. In this manner, three-dimensional freeform GOD microstructures with different GOD concentrations were developed. Furthermore, the biocomparability of the GOD microstructure with the help of added biomaterials such as BSA was verified under living cell incubation. (C) 2016 Optical Society of America
Graphene quantum dots conjugated with polymers for two-photon properties under two-photon excitation
(2016)
Kuo, Wen-Shuo
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Hsu, Chih-Li Lilian
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Chen, Hua-Han
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Chang, Chia-Yuan
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Kao, Hui-Fang
Few studies have investigated the two-photon properties of graphene quantum dots (GQDs) and GQD-conjugated polymers. The results of the present study revealed that conjugated polymers containing nitrogen and sulfur atoms caused higher quantum confinement of emissive energy to be trapped on the surface of nanomaterials, resulting in a high-photoluminescence quantum yield and notable two-photon properties. Additionally, the nanomaterials generated no reactive oxygen species-dependent oxidative stress on cells and served as promising two-photon contrast probes.
Hyperthermia Induced by Near-Infrared Laser-Irradiated CsWO3 Nanoparticles Disintegrates Preformed Lysozyme Amyloid Fibrils
(2020-03-01)
Hu, Po-Sheng
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Tomasovicova, Natalia
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Chou, Hsiu-Jen
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Li, Meng-Chang
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Vojtko, Marek
This research study attempts to prove the concept of the applicability of hyperthermia to treating the lysozyme amyloid fibrils (LAFs)'s self-assembled fibrillary aggregates by a feedback-modulated temperature controller ranging from 26 degrees C to 80 degrees C, and separately, by near-infrared (NIR) laser-irradiated cesium tungstate (CsWO3) nanoparticle (NPs). The dependence of the final morphology of the amyloidal assembly on external heating and the photothermal effect of the NPs on treating the fibrillary assembly were investigated and analyzed. Experimentally, atomic force microscopy (AFM), optical stereoscopy, and scanning electron microscopy (SEM) were used primarily to ensure mutual interaction between LAFs and NPs, optically elucidate the surface contour and final fibrillary assembly upon the influence of thermal treatment, and further reveal fine-details of the optical samples. Finally, conclusive remarks are drawn that the fibrillary structures doped with the NPs exhibit an increasing degree of unique orthogonality. As the temperature rises, utter deformation of the dendritic structures of fibrillary assemblies at 70 degrees C was found, and NIR laser-irradiated CsWO3 NPs have been demonstrated to be useful in topically destructing pre-assembled LAFs, which may be conducive to the future development of neurodegenerative therapeutic techniques.
Improved and fast biotissue imaging by temporal focusing widefield multiphoton microscopy with spatially modulated illumination
(2019-01-01)
Chang, Chia-Yuan
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Lin, Chun-Yu
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Hovhannisyan, Vladimir A.
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Chen, Shean-Jen
;
光電學院
A developed temporal focusing-based multiphoton microscope (TFMPM) has a digital micromirror device (DMD) which is adopted not only as a blazed grating for light spatial dispersion but also for patterned illumination simultaneously. Herein, the TFMPM has been extended to implement spatially modulated illumination at structured frequency and orientation to increase the beam coverage at the back-focal aperture of the objective lens. The axial excitation confinement (AEC) of TFMPM can be condensed from 3.0 mu m to 1.5 mu m for a 50% improvement. Furthermore, a multiline scanning mechanism based on the DMD can push its AEC nearly equivalent to line scanning-based TFMPM to 1.5 mu m from optimal 3.0 mu m of the conventional TFMPM. By using the TFMPM with structured illumination and multiline scanning, reconstructed biotissue images according to the condensed AEC structured illumination are shown obviously superior in contrast and better scattering suppression.
Improvement of axial excitation confinement in temporal focusing-based multiphoton microscopy via spatially modulated illumination
(2017-01-01)
Chang, Chia-Yuan
;
Chen, Shean-Jen
;
光電學院
;
College of Photonics
Conventional temporal focusing-based multiphoton excitation microscopy (TFMPEM) can offer widefield optical sectioning with an axial excitation confinement (AEC) of a few microns. Herein, a developed TFMPEM with a digital micromirror device (DMD), acting as the blazed grating for light spatial dispersion and simultaneous patterned illumination, has been extended to implement spatially modulated illumination at structured frequency and orientation. By implementing the spatially modulated illumination, the beam coverage at the back-focal aperture of the objective lens can be increased. As a result, the AEC can be condensed from 3.0 mu m to 1.5 mu m in full width at half maximum for a 2-fold enhancement. Furthermore, by using HiLo microscopy with two structured illuminations at the same spatial frequency but different orientation, biotissue images according to the structured illumination with condensed AEC is obviously superior in contrast and scattering suppression.
Multiphoton and confocal imaging of precisely cut oral cancer tumor sections for personalized medicine
(2020-01-01)
Chiang, Shu-Jen
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Tseng, Po-Hang
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Huang, Hsu-Cheng
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Chen, Shi-Chi
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Chen, Shean-Jen
Traditionally, testing of therapeutic agents uses two-dimensional cell cultures which does not recapitulate the complex, three-dimensional architecture of tissues. In the case of cancer drug development, immunotherapy (IT) emerged as an effective treatment strategy for the patients who respond to therapy. However, the overall patient response rate for immunotherapy is around 25%. Therefore, there is a need to develop more effective drug testing platform for cancer patients. In this work, we develop three-dimensional tissue cultures of human oral cancer slices. We observed the growth dynamics of the tissue sections for up to 28 days. Their viability over extended periods suggest that the tissue sections may be used for personalized drug testing.
Multiphoton imaging of dye penetration dynamics in tissue sections
(2020-01-01)
Tseng, Po-Hang
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Chiang, Shu-Jen
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Chen, Shean-Jen
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Dong, Chen-Yuan
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光電學院
Rapid and in-depth labeling biological tissue samples is invaluable for studying tissue organization in three-dimensions. The current strategy in finding optimal labeling parameters for dye molecules through tissues often requires trial and error testing. Difficulty in establishing a standard approach is due to lack of information on the diffusion parameters of dye through tissues. In this study, we investigate the temporal progression of dye penetration in different tissue types. By the combination of multiphoton imaging of labeled tissues and application of the theoretical model of diffusion with well-defined boundary conditions, we aim to arrive at systematic parameters for optimizing dye penetration. Determination of the effective diffusion coefficient of the dyes used will then be useful for further application.
Natural zeolite for adsorbing and release of functional materials
(2018-09-01)
Hovhannisyan, Vladimir Ararat
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Dong, Chen-Yuan
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Lai, Feng-Jie
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Chang, Nan-Shan
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Chen, Shean-Jen
Using multiphoton microscopy (MPM), we demonstrated that effective inducing of two-photon excited luminescence and second-harmonic generation signals in nano/microparticles of clinoptilolite type of zeolite (CZ) by femtosecond near-infrared laser excitation can be successfully utilized in multiphoton imaging of the drug adsorption processes. Adsorption of photodynamic active dyes (hypericin, chlorin e(6), methylene blue, and fluorescein) and their release from CZ pores in the presence of biomolecules, such as collagen from bovine Achilles tendon, albumin, and hemoglobin, were investigated by absorption and fluorescence spectrometry. To quantify the experimental results on hypericin release, here we use a kinetic curves fitting approach and calculate hypericin release rates in different environments. This approach allows to compare various mathematical models and uses more parameters to better characterize drug release profiles. In addition, magnetic CZ particles were fabricated and proposed as a promising material for drug delivery and controlled release in biological systems. Optical spectrometry and MPM are effective approaches that may reveal potential of natural zeolites in controlled drug delivery and biomedical imaging. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)
Photodynamic dye adsorption and release performance of natural zeolite
(2017-03-31)
Hovhannisyan, Vladimir
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Dong, Chen-Yuan
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Chen, Shean-Jen
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光電學院
;
College of Photonics
Clinoptilolite type of zeolite (CZ) is a promising material for biomedicine and pharmaceutics due to its non-toxicity, thermal stability, expanded surface area, and exceptional ability to adsorb various atoms and organic molecules into micropores. Using multiphoton microscopy, we demonstrated that individual CZ particles produce two-photon excited luminescence and second harmonic generation signal at femtosecond laser excitation, and adsorb photo-dynamically active dyes such as hypericin and methylene blue. Furthermore, the release of hypericin from CZ pores in the presence of biomolecules is shown, and CZ can be considered as an effective material for drug delivery and controlled release in biological systems. The results may open new perspectives in application of CZ in biomedical imaging, and introducing of the optical approaches into the clinical environment.
Rapid and highly integrated FPGA-based Shack-Hartmann wavefront sensor for adaptive optics system
(2018-01-01)
Chen, Yi-Pin
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Chang, Chia-Yuan
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Chen, Shean-Jen
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光電學院
;
College of Photonics
In this study, a field programmable gate array (FPGA)-based Shack-Hartmann wavefront sensor (SHWS) programmed on Lab VIEW can be highly integrated into customized applications such as adaptive optics system (AOS) for performing real-time wavefront measurement. Further, a Camera Link frame grabber embedded with FPGA is adopted to enhance the sensor speed reacting to variation considering its advantage of the highest data transmission bandwidth Instead of waiting for a frame image to be captured by the FPGA, the Shack-Hartmann algorithm are implemented in parallel processing blocks design and let the image data transmission synchronize with the wavefront reconstruction. On the other hand, we design a mechanism to control the deformable mirror in the same FPGA and verify the Shack-Hartmann sensor speed by controlling the frequency of the deformable mirror dynamic surface deformation. Currently, this FPGA-bead SHWS design can achieve a 266 Hz cyclic speed limited by the camera frame rate as well as leaves 40% logic slices for additionally flexible design.
Rapid volumetric multiphoton imaging with the combination of an ultrasound lens and a resonant mirror
(2018-01-01)
Hsu, Chia-Wei
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Chiang, Tsung-Yen
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Lai, Feng-Jie
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Chen, Shean-Jen
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光電學院
The combination of a tunable acoustic gradient (TAG) lens and a resonant mirror were integrated into a multiphoton excited (MPE) microscope that is rapidly and precisely controlled by an embedded field programmable gate array (FPGA) to acquire images at high frame rate.
Roles of nitrogen functionalities in enhancing the excitation-independent green-color photoluminescence of graphene oxide dots
(2017-06-28)
Teng, Chiao-Yi
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Ba-Son Nguyen
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Yeh, Te-Fu
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Lee, Yuh-Lang
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Chen, Shean-Jen
Fluorescent graphene oxide dots (GODs) are environmentally friendly and biocompatible materials for photoluminescence (PL) applications. In this study, we employed annealing and hydrothermal ammonia treatments at 500 and 140 degrees C, respectively, to introduce nitrogen functionalities into GODs for enhancing their green-color PL emissions. The hydrothermal treatment preferentially produces pyridinic and amino groups, whereas the annealing treatment produces pyrrolic and amide groups. The hydrothermally treated GODs (A-GODs) present a high conjugation of the nonbonding electrons of nitrogen in pyridinic and amino groups with the aromatic pi orbital. This conjugation introduces a nitrogen nonbonding (n(N 2p)) state 0.3 eV above the oxygen nonbonding state (n(O 2p) state; the valence band maximum of the GODs). The GODs exhibit excitation-independent green-PL emissions at 530 nm with a maximum quantum yield (QY) of 12% at 470 nm excitation, whereas the A-GODs exhibit a maximum QY of 63%. The transformation of the solvent relaxation-governed pi* -> n(O 2p) transition in the GODs to the direct pi* -> n(N 2p) transition in the A-GODs possibly accounts for the substantial QY enhancement in the PL emissions. This study elucidates the role of nitrogen functionalities in the PL emissions of graphitic materials and proposes a strategy for designing the electronic structure to promote the PL performance.
Smart Laser Weeding System
(2019-01-01)
Chang, Chia-Yuan
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Chang, Chia-Ying
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Huang, Xin-Ni
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Huang, Tzu-Cheng
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Wu, Chi-Yuan
Mechanical weeding is a necessary means to produce organic soybean in vast area and is the most effective for seedling of weed. However, the growth of weed is inconsistent; we must rely on the quantity of closely weeding to achieve the expected results. Organic cultivation adopts strip planting to reduce the cost of weeding, and uses the cultivator to remove weeds. This operation is slow and with high cost, and the artificial weeding is necessary in the later stage. In contrast, the field weeding robot can provide mechanical or physical prevention of weeds via monitor and image analysis. Therefore, this study aims to effectively increase production and solve the problems of labor shortage and high cost on labors by combining an unmanned ground vehicle with a developing smart laser weeding system for autonomous precise weeding. An intelligent image recognition is adopted to identify the position of the weed, and then through the laser tissue fibrosis to achieve the goal of precise weeding.
Temporal focusing-based multiphoton excitation fluorescence images with background noise cancellation via Hilbert-Huang transform
(2019-01-01)
Hu, Yvonne Yuling
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Luo, Yuan-Rong
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Lin, Chun-Yu
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Chang, Chia-Yuan
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Chen, Shean-Jen
Temporal focusing multiphoton excitation microscopy has wide field-of-view and optical sectioning. By using digital micromirror device, it provides patterned illumination. However, without filling the back aperture of objective lens, the axial confinement is limited to micron-meters, leading the out-of-focus fluorophores excited and image blurred. In this study, Hilbert-Huang transform is proposed to reduce the background noise. The empirical mode decomposition is first applied to disassemble the image into intrinsic mode functions and then reconstruct by Hilbert transform after diminishing background residues. The axial confinement can be enhanced from 2.79 mu m to 0.73 mu m with structure frequency in 1.06 mu m(-1).
Temporal focusing-based widefield multiphoton microscopy with spatially modulated illumination for biotissue imaging
(2018-01-01)
Chang, Chia-Yuan
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Lin, Cheng-Han
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Lin, Chun-Yu
;
Sie, Yong-Da
;
Hu, Yvonne Yuling
A developed temporal focusing-based multiphoton excitation microscope (TFMPEM) has a digital micromirror device (DMD) which is adopted not only as a blazed grating for light spatial dispersion but also for patterned illumination simultaneously. Herein, the TFMPEM has been extended to implement spatially modulated illumination at structured frequency and orientation to increase the beam coverage at the back-focal aperture of the objective lens. The axial excitation confinement (AEC) of TFMPEM can be condensed from 3.0 mm to 1.5 mm for a 50% improvement. By using the TFMPEM with HiLo technique as two structured illuminations at the same spatial frequency but different orientation, reconstructed biotissue images according to the condensed AEC structured illumination are shown obviously superior in contrast and better scattering suppression. Picture: TPEF images of the eosin-stained mouse cerebellar cortex by conventional TFMPEM (left), and the TFMPEM with HiLo technique as 1.09 mm(-1) spatially modulated illumination at 908 (center) and 08 (right) orientations. [GRAPHICS] .
Three-dimensional patterned graphene oxide-quantum dot microstructures via two-photon crosslinking
(2017-12-01)
Lin, Chun-Yu
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Chang, Hsin-Yu
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Yeh, Te-Fu
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Teng, Hsisheng
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Chen, Shean-Jen
The two-photon crosslinking of graphene oxide-quantum dots (GOQDs) adopts rose Bengal as the photoactivator to induce the GOQD assembly process. Based on the Forster resonance energy transfer mechanism with oxygen as the crosslinking medium, three-dimensional patterned GOQD microstructures with near diffraction-limit spatial resolution have been fabricated and analyzed by a multiphoton excited fabrication instrument/microscope. (C) 2017 Optical Society of America
Two-Photon Photoexcited Photodynamic Therapy and Contrast Agent with Antimicrobial Graphene Quantum Dots
(2016-11-09)
Kuo, Wen-Shun
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Chang, Chia-Yuan
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Chen, Hua-Han
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Hsu, Chih-Li Lilian
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Wang, Jiu-Yao
A graphene quantum dot (GQD) used as the photosensitizer with high two-photon absorption in the near-infrared region, a large absolute cross section of two-photon excitation (TPE), strong two-photon luminescence, and impressive two-photon stability could be used for dual modality two-photon photodynamic therapy (PDT) and two-photon bioimaging with an ultrashot pulse laser (or defined as TPE). In this study, a GQD efficiently generated reactive oxygen species coupled with TPE, which highly increased the effective PDT ability of both Gram-positive and-negative bacteria, with ultralow energy and an extremely short photoexcitation time generated by TPE. Because of its two-photon properties, a GQD could serve,as a promising two photon contrast agent for observing specimens in depth in three-din-tensional biological environments while simultaneously proceeding with PDT action to eliminate bacteria, particularly in multidrug-resistant (MDR) strains. This procedure would provide an efficient alternative approach to easily cope with MDR bacteria.