Browsing by Author "Chang, Wen-Tsan"

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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
;
Chen, Hua-Han
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Chang, Chia-Yuan
;
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.
Lower protein expression levels of MHC class I chain-related gene A in hepatocellular carcinoma are at high risk of recurrence after surgical resection
(2018-10-25)
Huang, Chung-Feng
;
Wang, Shu-Chi
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Chang, Wen-Tsan
;
Yeh, Ming-Lun
;
Huang, Ching-I
MHC class I chain-related gene A (MICA) variants have been associated with hepatocellular carcinoma (HCC). Their association with MICA expression in cancer cells and cancer recurrence is unknown. SNP rs2596542 of MICA was tested in 193 HCC patients with surgical resection. The corresponding MICA expression in the cancer tissue was measured by immunochemistry microarray. Patients with the SNP rs2596542 A allele had significantly lower MICA expression in tumor tissue than did those with the GG genotype (24.7 +/- 15.1% vs. 41.5 +/- 23.4%, P < 0.001). Patients who had HCC recurrence had significantly lower MICA expression in tumor tissue (34.2 +/- 21.8% vs. 24.0 +/- 19.8%, P = 0.03). Cox regression analysis revealed that the factors independently predictive of HCC recurrence included low MICA expression (hazard ratio [HR]/95% confidence intervals [CI]: 2.77/1.07-7.14, P = 0.035) and tumor size (HR/CI: 5.22/2.11-12.96, P < 0.001). Compared to patients with tumors <5 cm and MICA expression >30%, patients with either one and both two risk factors had HCC HRs of 9.76 (C.I. 1.27-75.03, P = 0.03) and 27.30 (C.I. 3.46-215.6, P = 0.002), respectively. We concluded that low cellular MICA expressions were at a greater risk of HCC recurrence after curative treatment.
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
;
Chen, Hua-Han
;
Hsu, Chih-Li Lilian
;
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.