Browsing by Author "Chen, Yu-Jen"

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A NOVEL NANOELECTROMAGNETIC SYSTEM USING MULTIFERROIC/MAGNETOELECTRIC NI-NANO-CHEVRON/PMN-PT HETEROSTRUCTURE TO DEMONSTRATE AN ELECTRIC -FIELD -CONTROLLED PERMANENT MAGNETIC SINGLE -DOMAIN TRANSFORMATION
(2018-01-01)
Cheng, Chih-Cheng
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Lin, Shin-Hung
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Chen, Yu-Jen
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Wang, Hsin-Min
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Chu, Hou-Jen
In this paper, we report a novel nanoelectromagnetic system using multiferroic/magnetoelectric Ni-nanochevron/PMN-PT heterostructure to demonstrate an electric field -controlled permanent magnetic single-domain transformation. The heterostructure consists of a magnetostrictive Ni-nano-chevron, Pt top and bottom electrodes, and a piezoelectric PMN-PT substrate. In initial state (as demagnetized), the magnetization of the magnetic single domain is stably along the long axis of the nano-chevron. A magnetic field of 3000 Oe (along 45 degree of nano-chevron) is applied to magnetize the Ni-nano-chevron from stable single domain to metastable two-domains. After this, an electric field of 0.8MV/m is applied to the PMN-PT substrate to produce the converse magnetoelectric effect to transform the two-domains. After the electric field is removed, the two-domains are further transformed back to the single-domain. Finally, when comparing the domains before and after applying our approach, approximately 50 % of single-domains are successfully and permanently switched (i.e., magnetization-direction is permanently rotated 180 degrees).
A switch-on MRI contrast agent for noninvasive visualization of methylmercury
(2015-01-01)
Singh, Gyan
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Hsu, Kuang-Mei
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Chen, Yu-Jen
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Wu, Shou-Cheng
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Chen, Chiao-Yun
This communication presents the first Gd(III)-based T-1 MRI contrast agent, o-MeHgGad, for noninvasive visualization of CH3Hg+. o-MeHgGad showed a relaxivity enhancement of 62% in the presence of 1 equiv. of CH3Hg+. Moreover, a noticeable contrast enhancement was recorded in the liver, kidney, and intestine of mice exposed to CH3Hg+. Thus, the newly designed contrast agent has the potential to be used for in vivo bio-imaging of CH3Hg+ and could be useful for biomedical applications.
A water soluble and fast response fluorescent turn-on copper complex probe for H2S detection in zebra fish
(2016-01-15)
Palanisamy, Sathyadevi
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Lee, Lu-Ying
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Wang, Yu-Liang
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Chen, Yu-Jen
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Chen, Chiao-Yun
According to the displacement method, herein we reported a water soluble copper complex [Cu(MaT-cyclen)(2)] as a fluorescent probe for the detection of H2S. For this, 1((1-(10-methylanthracen-9-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-1,4,7,10-tetraazacyclododecane (MaT-cyclen) was synthesized first To improve its solubility in aqueous media, sodium acetate group was introduced into 8-hydroxy-2-quinoline successfully. MaT-cyclen was chelated with Cu(II) to form [Cu(MaT-cyclen)2] complex, which displayed high sensitivity and selectivity for H2S over the other possible competitive substances on the basis of forming CuS. Meanwhile, [Cu(MaT-cyclen)(2)] displayed rapid response (< 1 min), well reversibility, lowest detection limit (205 nM), and high sensitivity for recognizing H2S in aqueous solution. Furthermore, its potential utility for biological applications was confirmed by fluorescence imaging of H2S in live cells as well as in zebra fish. (C) 2015 Elsevier B.V. All rights reserved.
Activation of Angiogenesis and Wound Healing in Diabetic Mice Using NO-Delivery Dinitrosyl Iron Complexes
(2019-10-01)
Chen, Yu-Jen
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Wu, Shou-Cheng
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Wang, Hsiang-Ching
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Wu, Tung-Ho
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Yuan, Shyng-Shiou F.
In diabetes, abnormal angiogenesis due to hyperglycemia and endothelial dysfunction impairs wound healing and results in high risks of diabetic foot ulcers and mortality. Alternative therapeutic methods were attempted to prevent diabetic complications through the activation of endothelial nitric oxide synthase. In this study, direct application of nitric oxide using dinitrosyl iron complexes (DNICs) to promote angiogenesis and wound healing under physiological conditions and in diabetic mice is investigated. Based on in vitro and in vivo studies, DNIC [Fe-2(mu-SCH2CH2OH)(2)(NO)(4)] (DNIC-1) with a sustainable NO-release reactivity (t(1/2) = 27.4 +/- 0.5 h at 25 degrees C and 16.8 +/- 1.8 h at 37 degrees C) activates the NO-sGC-cGMP pathway and displays the best proangiogenesis activity overwhelming other NO donors and the vascular endothelial growth factor. Moreover, this pro-angiogenesis effect of DNIC-1 restores the impaired angiogenesis in the ischemic hind limb and accelerates the recovery rate of wound closure in diabetic mice. This study translates synthetic DNIC-1 into a novel therapeutic agent for the treatment of diabetes and highlights its sustainable (NO)-N-center dot-release reactivity on the activation of angiogenesis and wound healing.
Antiviral Activity of a Llama-Derived Single-Domain Antibody against Enterovirus A71
(2020-05-01)
Huang, Peng-Nien
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Wang, Hsiang-Ching
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Hung, Hui-Chen
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Tseng, Sung-Nien
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Chang, Teng-Yuan
In the past few decades, enterovirus A71 (EVA71) has caused devastating outbreaks in the Asia-Pacific region, resulting in serious sequelae in infected young children. No preventive or therapeutic interventions are currently available for curing EVA71 infection, highlighting a great unmet medical need for this disease. Here, we showed that one novel single-domain antibody (sdAb), F1, isolated from an immunized llama, could alleviate EVA71 infection both in vitro and in vivo. We also confirmed that the sdAb clone F1 recognizes EVA71 through a novel conformational epitope comprising the highly conserved region of VP3 capsid protein by using competitive-binding and overlapping-peptide enzyme-linked immunosorbent assays (ELISAs). Because of the virion's icosahedral structure, we reasoned that adjacent epitopes must be clustered within molecular ranges that may be simultaneously bound by an engineered antibody with multiple valency. Therefore, two singledomain binding modules (F1) were fused to generate an sdAb-in-tandem design so that the capture of viral antigens could be further increased by valency effects. We showed that the tetravalent construct F1xF1-hFc, containing two sdAb-intandem on a fragment crystallizable (Fc) scaffold, exhibits more potent neutralization activity against EVA71 than does the bivalent sdAb F1-hFc by at least 5.8-fold. We also demonstrated that, using a human scavenger receptor class B member 2 (hSCARB2) transgenic mouse model, a half dose of the F1xF1-hFc provided better protection against EVA71 infection than did the F1-hFc. Thus, our study furnishes important insights into multivalent sdAb engineering against viral infection and provides a novel strategic deployment approach for preparedness of emerging infectious diseases such as EVA71.
Bridging donor-acceptor energy offset using organic dopants as energy ladders to improve open-circuit voltages in bulk-heterojunction solar cells
(2014-12-01)
Chang, Jan-Kai
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Kuo, Ya-Ching
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Chen, Yu-Jen
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Lo, An-Lun
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Liu, I-Hsiu
A systematic way to improve the open circuit voltage of bulk-heterojunction (BHJ) organic photovoltaics is demonstrated by incorporating energy ladder material to form a ternary blend with cascade energy structures. We propose that doping organic molecules with appropriate energetic alignment to bridge the donor-acceptor energy offset can facilitate exciton dissociation and hence improve open-circuit voltage (V-oc) and power conversion efficiency. The cascade energy alignment structure is measured via ultraviolet photoemission spectroscopy. The Voc and power conversion efficiency of devices using the proposed schemes can be enhanced by 10% and 20%, respectively. The results provide a new path toward higher power conversion efficiency in BHJ systems by engineering the energy structures of the materials in the active layers. (C) 2014 Elsevier B.V. All rights reserved.
Development of a Mucin4-Targeting SPIO Contrast Agent for Effective Detection of Pancreatic Tumor Cells in Vitro and in Vivo
(2013-11-28)
Wu, Shou-Cheng
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Chen, Yu-Jen
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Lin, Yi-Jan
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Wu, Tung-Ho
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Wang, Yun-Ming
In search of a unique and reliable contrast agent targeting pancreatic adenocarcinoma, new multifunctional nanoparticles (MnMEIO-silane-NH2-(MUC4)-mPEG NPs) were successfully developed in this study. Mucin4-expression levels were determined through different imaging studies in a panel of pancreatic tumor cells (HPAC, BxPC-3, and Panc-1) both in vitro and in vivo studies. The in vitro T-2-weighted MR imaging study in HPAC and Panc-1 tumor cells treated with NPs showed -89.1 +/- 5.7% and -0.9 +/- 0.2% contrast enhancement, whereas in in vivo study, it is found to be -81.5 +/- 4.5% versus -19.6 +/- 5.2% (24 h postinjection, 7.0 T), respectively. The T-2-weighted MR and optical imaging studies revealed that the novel agent can specifically and effectively target to mucin4-expressing tumors in nude mice. Hence, it is suggested that MnMEIO-silane-NH2-(MUC4)-mPEG NPs are able to provide an efficient and targeted delivery of MUC4 antibodies to mucin4-expressing pancreatic tumors.
ELECTRICAL CONTROL OF MAGNETIC MULTI-DOMAIN TRANSFORMATION IN A SPECIFIC GEOMETRIC-PATTERNED NI NANOSTRUCTURE ON A PIEZOELECTRIC [PB(MG(1/3)NB(2/3))O3](0.68)-[PBTIO3](0.32) SUBSTRATE
(2016)
Chen, Yu-Jen
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Chung, Tien-Kan
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Lin, Po-Jung
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Hung, Chiao-Fang
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Chu, Hou-Jen
In this paper, we report an electrical control of magnetic multi-domain-walls transformation in an N-shape-patterned Ni nanostructures on a piezoelectric [Pb(Mg1/3Nb2/3)O-3](0.68)-[PbTiO3](0.32) substrate. Based on the converse-magnetoelectric-effect induced domain-wall transformation and the specific N-shape geometry guided domain-wall motion, the domain walls are successfully transformed by an applied electric field of 0.8 MV/m from the transverse domain wall state into the flux closure vortex domain state. These experimental results achieve the electrical control of multi-domain-walls transformation and would create more data storage and memory applications in the future.
Highly Selective Fluorescent Sensors for Hg(2+) and Ag(+) Based on Bis-triazole-Coupled Polyoxyethylenes in MeOH Solution
(2009-12-01)
Hung, Hao-Chih
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Cheng, Chi-Wen
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Wang, Yu-Yun
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Chen, Yu-Jen
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Chung, Wen-Sheng
Fluorescent chemosensors 6-9, with variable length polyoxyethylenes between two triazolylmethyl ether units, have been synthesized under "click" conditions in which the bis-triazoles and polyoxyethylenes were used as metal-ion binding sites and the pyrenes as fluorophores. Of the 15 metal ions screened, the fluorescence of chemosensors 6-9 in methanol solution was found to be selectively quenched by only Hg(2+) and Ag(+). In contrast, the fluorescence of control compound 10, a [(triazol-4-yl)methoxymethyl]pyrene, was quenched by only Hg(2+). These results imply that the recognition of Hg(2+) does not need the cooperation of two triazole groups. Binding constants for the interactions of 6-9 with Ag(+) increased as the chain length of the polyoxyethylene increased. Finally, a very high selectivity of compound 9 towards Hg(2+) in aqueous methanol solution was observed. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Highly Selective Fluorescent Sensors for Hg2+ and Ag+ Based on Bis-triazole-Coupled Polyoxyethylenes in MeOH Solution
(2009-12-01)
Hung, Hao-Chih
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Cheng, Chi-Wen
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Wang, Yu-Yun
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Chen, Yu-Jen
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Chung, Wen-Sheng
Fluorescent chemosensors 6-9, with variable length polyoxyethylenes between two triazolylmethyl ether units, have been synthesized under "click" conditions in which the bis-triazoles and polyoxyethylenes were used as metal-ion binding sites and the pyrenes as fluorophores. Of the 15 metal ions screened, the fluorescence of chemosensors 6-9 in methanol solution was found to be selectively quenched by only Hg2+ and Ag+. In contrast, the fluorescence of control compound 10, a [(triazol-4-yl)methoxymethyl]pyrene, was quenched by only Hg2+. These results imply that the recognition of Hg2+ does not need the cooperation of two triazole groups. Binding constants for the interactions of 6-9 with Ag+ increased as the chain length of the polyoxyethylene increased. Finally, a very high selectivity of compound 9 towards Hg2+ in aqueous methanol solution was observed. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
In Vitro and in Vivo Imaging of Nitroxyl with Copper Fluorescent Probe in Living Cells and Zebrafish
(2018-10-01)
Palanisamy, Sathyadevi
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Wang, Yu-Liang
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Chen, Yu-Jen
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Chen, Chiao-Yun
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Tsai, Fu-Te
Nitroxyl (HNO) plays a critical role in many physiological processes which includes vasorelaxation in heart failure, neuroregulation, and myocardial contractility. Powerful imaging tools are required to obtain information for understanding the mechanisms involved in these in vivo processes. In order to develop a rapid and high sensitive probe for HNO detection in living cells and the zebrafish model organism, 2-((2-(benzothiazole-2yl)benzylidene) amino)benzoic acid (AbTCA) as a ligand, and its corresponding copper(II) complex Cu(II)-AbTCA were synthesized. The reaction results of Cu(II)-AbTCA with Angeli's salt showed that Cu(II)-AbTCA could detect HNO quantitatively in a range of 40-360 mu M with a detection limit of 9.05 mu M. Furthermore, Cu(II)-AbTCA is more selective towards HNO over other biological species including thiols, reactive nitrogen, and reactive oxygen species. Importantly, Cu(II)-AbTCA was successfully applied to detect HNO in living cells and zebrafish. The collective data reveals that Cu(II)-AbTCA could be used as a potential probe for HNO detection in living systems.
In vitro and in vivo imaging of peroxynitrite by a ratiometric boronatebased fluorescent probe
(2017-05-15)
Palanisamy, Sathyadevi
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Wu, Pei-Yu
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Wu, Shou-Cheng
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Chen, Yu-Jen
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Tzou, Shey-Cherng
Peroxynitrite (ONOO-) is an important species involved in many physiopathological processes. Progresses have been made in developing novel fluorescent probes to detect peroxynitrite with relatively high sensitivity and specificity. Herein, we report the synthesis, characterization and biological applications of a new boronate-based fluorescent probe, 4-MB. The studies showed that 4-MB exhibits a dual ratiometric and calorimetric response toward peroxynitrite due to ONOO--triggered oxidative reaction. A possible mechanism of the oxidation reaction was proposed and the reaction product was isolated and characterized using different spectroscopic methods. We have thoroughly demonstrated the utility of 4-MB for intracellular peroxynitrite imaging. Further, we showed that 4-MB can be potentially employed to visualize exogenous and endogenous peroxynitrite in RAW264.7 macrophages, EAhy926 cells, zebrafish and in live tissues from a high-fat diet-induced obese mouse model.
Label-free characterization of collagen fibers in cancerous esophagus tissues using ratiometric nonlinear optical microscopy
(1970-01-01)
Chen, Wei-Chung
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Chen, Yu-Jen
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Lin, Shih-Ting
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Hung, Wei-Han
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Chan, Ming-Che
A quantitative analytical method to discriminate among the various types of cancerous esophagus tissue is essential for accurate cancer staging. This paper reports on the use of ratiometric nonlinear optical microscopy to reveal the ratio of two-photon excited fluorescence (TPEF) to second harmonic generation (SHG) and forward to backward (F/B) SHG from single collagen fibers only in submucosa of esophageal squamous cell carcinoma. This makes it possible to accurately differentiate among the four stages of esophageal cancer, providing results that are in good agreement with histopathology. Furthermore, it is confirmed by polarization-dependent SHG that the varied SHG response in esophageal cancer tissues is mainly from the shrinkage in diameter of collagen fibers instead of the collagen triple helixes altered by cancer cells. Based on the results of TPEF/SHG and F/B SHG ratio, they can cooperatively improve the precision of diagnostics on esophageal cancer and could be transferred to other types of cancer diseases with changed collagen fibers. Impact statement The issue of classifying esophageal cancer at various developmental stages is crucial for determining the optimized treatment protocol for the patients, as well as the prognosis. Precision improvement in staging esophageal cancer keeps seeking quantitative and analytical imaging methods that could augment histopathological techniques. In this work, we used nonlinear optical microscopy for ratiometric analysis on the intrinsic signal of two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) from single collagen fibers only in submucosa of esophageal squamous cell carcinoma (ESCC). The blind tests of TPEF/SHG and forward (F)/backward (B) SHG were demonstrated to compare with the histology conclusion. The discussion of sensitivity and specificity was provided via statistical comparison between the four stages of esophageal cancer. To the best of our knowledge, this is the first study of using these two ratios in combination for staging ESCC.
Magnetic-field-assisted electric-field-controlled rotation of magnetic stripe domains in a magnetoelectric Ni microbar/[Pb(Mg1/3Nb2/3)O-3](0.68)-[PbTiO3](0.32) heterostructure
(2016-04)
Chung, Tien-Kan
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Wang, Hsin-Min
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Chen, Yu-Jen
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Lin, Shin-Hung
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Chu, Hou-Jen
We report a magnetic-field-assisted electric-field-controlled approach to rotate magnetic stripe domains in a magnetoelectric Ni-microbar/[Pb(Mg1/3Nb2/3)O-3](0.68)-[PbTiO3](0.32) heterostructure. A magnetic field is applied for magnetizing the microbar\'s stripe domains along the microbar\'s short/magnetic-hard axis. Subsequently, an electric field is applied for induction of a transformation of domains through the converse magnetoelectric effect. Owing to the microbar\'s geometry, the transformation causes the stripe domains to rotate away from the short/magnetichard axis toward the long/magnetic-easy axis. The rotation angle increases in proportion to the increasing electric field intensity. A maximal rotation of 90 degrees is obtained at the electric field intensity of 0.8MV/m. The rotation state persists after removing the electric field. (C) 2016 The Japan Society of Applied Physics
Origins of vertical phase separation in P3HT:PCBM mixed films
(2014-04-01)
Liu, I-Hsiu
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Chao, Yi-Ping
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Fang, Jian-Jhih
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Tseng, Wei-Hsuan
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Lan, Yu-Bing
The origins of vertical phase separation and their implication on the device efficiency of poly(3-hexylthiophene):[6,6]-phenyl C61-butyric acid methyl ester (P3HT:PCBM) based solar cells, with both regular and inverted structures, were investigated. We found that the light irradiation and the filtration processes during the device fabrications are two key steps that induce the vertical phase separation in the active layers. Upon light irradiation, the devices with inverted structures exhibit improved power conversion efficiency, whereas the regular devices show degradation. The inverted devices spun cast with filtered P3HT:PCBM solution also present a better improvement as compared to regular devices. X-ray and ultraviolet photoemission spectroscopies indicate that both illumination and filtration enhance the vertical phase separation of the blend film with additional PCBM segregated to the bottom interface. (C) 2014 The Japan Society of Applied Physics
Peptide-based MRI contrast agent and near-infrared fluorescent probe for intratumoral legumain detection
(2014-01-01)
Chen, Yu-Jen
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Wu, Shou-Cheng
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Chen, Chung-Yung
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Tzou, Shey-Cherng
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Cheng, Tian-Lu
Recent studies suggest that intratumoral legumain promotes tumorigenesis. To monitor legumain activity in tumors, we developed a new MM contrast agent ([Gd-NBCB-TTDA-Leg(L)]) and a NIR fluorescence probe (CyTE777-Leg(L)-CyTE807). The MRI contrast agent was prepared by introduction of cyclobutyl and benzyl group residues to TTDA (3,6,10-tri(carboxymethyl)-3,6,10-triaza-dodecanedioic acid), followed by the attachment of a legumain-specific substrate peptide (Leg(L)). The NIR fluorescence probe was designed by conjugating two NIR fluorochromes (CyTE777 and CyTE807) with Leg(L). Peptide cleavage of the MM contrast agent by legumain can increase its hydrophobicity and promote rotational correlation time (tau(R)). Peptide cleavage of the NIR probes by the legumain relieves the self quench of the probe. Peptide cleavage of the MRI contrast agent and the NIR fluorescence probe by legumain were confirmed by T-1 relaxometric studies and by fluorescence studies, respectively. In vivo MR images showed that [Gd-NBCB-TTDA-Leg(L)] attained 55.3 fold (254.2% versus 4.6%, at 2.0 h post-injection) higher imaging enhancement, as compared with control contrast agent bearing a noncleaveable peptide ([Gd-NBCB-TTDA-Leg(D)], in the CT-26 (legumain(+)) tumors. Similarly, optical imaging probe CyTE777-Leg(L)-CyTE807 attained 15.2 fold (3.34 x 10(9) photons/min versus 0.22 x 10(9) photons/min, at 24.0 h post-injection) higher imaging enhancement in the CT-26 (legumain(+)) tumors, compared to a NIR control probe (CyTE777-Leg(D)-CyTE807). These data indicate that the [Gd-NBCB-TTDA-Leg(L)] and the CyTE777-Leg(L)-CyTE807 probes may be promising tools to image the legumain-expressing cancers for diagnoses and targeted treatments. (C) 2013 Elsevier Ltd. All rights reserved.
Phomaketide A Inhibits Lymphangiogenesis in Human Lymphatic Endothelial Cells
(2019-04-01)
Tai, Huai-Ching
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Lee, Tzong-Huei
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Tang, Chih-Hsin
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Chen, Lei-Po
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Chen, Wei-Cheng
Lymphangiogenesis is an important biological process associated with cancer metastasis. The development of new drugs that block lymphangiogenesis represents a promising therapeutic strategy. Marine fungus-derived compound phomaketide A, isolated from the fermented broth of Phoma sp. NTOU4195, has been reported to exhibit anti-angiogenic and anti-inflammatory effects. However, its anti-lymphangiogenic activity has not been clarified to date. In this study, we showed that phomaketide A inhibited cell growth, migration, and tube formation of lymphatic endothelial cells (LECs) without an evidence of cytotoxicity. Mechanistic investigations revealed that phomaketide A reduced LECs-induced lymphangiogenesis via vascular endothelial growth factor receptor-3 (VEGFR-3), protein kinase C (PKC), and endothelial nitric oxide synthase (eNOS) signalings. Furthermore, human proteome array analysis indicated that phomaketide A significantly enhanced the protein levels of various protease inhibitors, including cystatin A, serpin B6, tissue factor pathway inhibitor (TFPI), and tissue inhibitor matrix metalloproteinase 1 (TIMP-1). Importantly, phomaketide A impeded tumor growth and lymphangiogenesis by decreasing the expression of LYVE-1, a specific marker for lymphatic vessels, in tumor xenograft animal model. These results suggest that phomaketide A may impair lymphangiogenesis by suppressing VEGFR-3, PKC, and eNOS signaling cascades, while simultaneously activating protease inhibitors in human LECs. We document for the first time that phomaketide A inhibits lymphangiogenesis both in vitro and in vivo, which suggests that this natural product could potentially treat cancer metastasis.
Photochemistry of benzene and quinoxaline fused Delta(2)-1,2,3-triazolines and their trapping products
(2010-01-02)
Chen, Yu-Jen
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Hung, Hao-Chih
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Sha, Chin-Kang
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Chung, Wen-Sheng
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應用化學系
The benzene and quinoxaline fused Delta(2)-1,2,3-triazolines 1a and 1b were synthesized in good yields using Knoevenagel condensation and intramolecular 1,3-dipolar cycloaddition as two of the key reactions. Photolysis (254 nm) of Delta(2)-1,2,3-triazoline 1a or 1b in acetonitrile led to the homolytic cleavage of nitrogen that generated diethyl diazomalonate 7, highly reactive intermediates aziridines 8a,b, and isoindoles B. The latter two species subsequently underwent rearrangement to give the nitrogen extrusion products 9a,b, and polymers. Furthermore, the reactive intermediates were trapped by dienophiles to give the corresponding cycloadducts. Subsequent rearrangement of the N-bridged cycloadducts gave N-substituted pyrrolo[3,4-b]quinoxalines 12b and 15b in 6% and 9% yields, respectively. Irradiation of 1a in the presence of fumaronitrile led to the isolation of cycloadduct 16a with retention of stereochemistry. Thermal reaction of 1b gave more nitrogen extruded product 9b (58-63% yield) than that by photolysis (5-23% yield), which implied that zwitterionic intermediate might be involved in the former. (C) 2009 Elsevier Ltd. All rights reserved.
Reaction-based epoxide fluorescent probe for in vivo visualization of hydrogen sulfide
(2015-06-15)
Sathyadevi, Palanisamy
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Chen, Yu-Jen
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Wu, Shou-Cheng
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Chen, Yen-Hao
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Wang, Yun-Ming
Hydrogen sulfide (H2S) has emerged as the most important biosynthetic gasotransmitters along with nitric oxide (NO) and carbon monoxide (CO). In this study, we report the design and the synthesis of a new epoxide fluorescent probe 7-glycidyloxy-9-(2-glycidyloxycarbonylphenyl)-2-xanthone (FEPO) for use in in vivo visualization of hydrogen sulfide. The probe employs a fluorescein as a fluorophore, and is equipped with an operating epoxide unit. FEPO functions via epoxide ring opening upon nucleophilic attack of H2S. This ring opening strategy may open a new avenue for the development of various H2S fluorescent sensors. FEPO showed high selectivity and high sensitivity for H2S. FEPO\'s cytotoxicity was tested using MTT (2-(4,5-dimethyl-2-thiazolyl)-3,5-diphenyl-2H-tetrazolium bromide) assay. Furthermore, the use of confocal imaging of H2S and in vivo imaging in live zebra fish demonstrated FEPO\'s potential biological applications. We anticipate that, owing to their ideal properties, probes of this type will find great uses in exploring the role of H2S in biology. (C) 2015 Elsevier B.V. All rights reserved.
Security optical data storage in Fourier holograms
(2012-03-20)
Su, Wei-Chia
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Chen, Yu-Wen
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Chen, Yu-Jen
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Lin, Shiuan-Huei
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Wang, Li-Karn
We have proposed and demonstrated a holographic security storage system that is implemented with a shift multiplexing technique. The security function of this storage system is achieved by using a micro-diffuser (MD) for random phase encoding of the reference beams. The apparatus of random phase encoding in this system offers an additional and flexible function during the recording processes. The system can generate holographic security memory or nonsecurity holographic memory via using the MD or not. The storage capacity and the average signal-to-noise value of the security storage system are 16 bits/mu m(2) and 3.5, respectively. Lateral shifting selectivity in this holographic security storage system is theoretically analyzed and experimentally investigated. (C) 2012 Optical Society of America