Browsing by Author "Chung, Chih-Han"

Now showing 1 - 2 of 2

5-Demethyltangeretin is more potent than tangeretin in inhibiting dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin tumorigenesis
(2014-11-01)
Ma, Nianhan
;
Lai, Ching-Shu
;
Chung, Chih-Han
;
Yang, Jinn-Moon
;
Hsu, Kai-Cheng
5-Demethyltangeretin (5-DTAN), an autohydrolysis product of tangeretin (TAN) found in citrus peel, exhibited more potent anti-proliferative activity in human cancer cells than TAN itself. In this study, we investigated the anti-tumor promoting effect and underlying molecular mechanism of 5-DTAN on 7,12-dimethyl-benz(a)anthracene (DMBA)-induced and 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted skin carcinogenesis. Application of 5-DTAN prior to each TPA-treatment was more effective than that of TAN on reducing the number, incidence and size of papillomas in DMBA-initiated mouse skin. Moreover, 5-DTAN suppressed cyclooxygenase-2 (COX-2) protein expression more strongly than TAN through interfering with phosphatidylinositiol 3-kinase (PI3K)/Akt signaling and further activation of transcription factor NF-kappa B. Taken together, these results revealed for the first time the in vivo chemopreventive efficacy of 5-DTAN on inhibition of skin carcinogenesis through promoting apoptosis and molecular interactions with residues of PI3K, COX-2, and AKT that may potentially serve as a novel functional agent capable of preventing inflammation-associated tumorigenesis. (C) 2014 Elsevier Ltd. All rights reserved.
iVRNote: Design, Creation and Evaluation of an Interactive Note-Taking Interface for Study and Reflection in VR Learning Environments
(2019-01-01)
Chen, Yi-Ting
;
Hsu, Chi-Hsuan
;
Chung, Chih-Han
;
Wang, Yu-Shuen
;
Babu, Sabarish V.
In this contribution, we design, implement and evaluate the pedagogical benefits of a novel interactive note taking interface (iVRNote) in VR for the purpose of learning and reflection lectures. In future VR learning environments, students would have challenges in taking notes when they wear a head mounted display (HMD). To solve this problem, we installed a digital tablet on the desk and provided several tools in VR to facilitate the learning experience. Specifically, we track the stylus' position and orientation in the physical world and then render a virtual stylus in VR. In other words, when students see a virtual stylus somewhere on the desk, they can reach out with their hand for the physical stylus. The information provided will also enable them to know where they will draw or write before the stylus touches the tablet. Since the presented iVRNote featuring our note taking system is a digital environment, we also enable students save efforts in taking extensive notes by providing several functions, such as post-editing and picture taking, so that they can pay more attention to lectures in VR. We also record the time of each stroke on the note to help students review a lecture. They can select a part of their note to revisit the corresponding segment in a virtual online lecture. Figures and the accompanying video demonstrate the feasibility of the presented iVRNote system. To evaluate the system, we conducted a user study with 20 participants to assess the preference and pedagogical benefits of the iVRNote interface. The feedback provided by the participants were overall positive and indicated that the iVRNote interface could be potentially effective in VR learning experiences.