Electron Heating and Current Scaling in a GaAs Two-Dimensional Electron System

Po Zhung Chen,Li-Hung Lin,C.T. Liang,D.A. Ritchie,Jing-Han Chen,Jyunn-Ying Lin,M.Y. Simmons 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.6

We present experimental results on hot-carrier phenomena in a GaAs/AlGaAs two-dimensional electron system in the integer and fractional quantum Hall regions. In the integer region at low magnetic fields, a relationship $T_e$ $\sim$ $I^{0.52}$ between the effective carrier temperature $T_e$ and the source-drain current $I$ is obtained from Shubnikov-de Haas (SdH) oscillations at several magnetic fields, 0.2 $\sim$ 0.5 T, and currents, 0.1 $\sim$ 4 $\mu$A. These results are in agreement with results obtained in the current-dependent broadening of resistance peaks in the quantum Hall region of spin-split Landau levels. However, in the fractional region for the filling factor $\nu = 5/3 (B = 7$ T), a power law relationship $T_e$ $\sim$ $I^{0.37}$ is obtained. The difference in exponent may be due to different energy relaxation mechanisms between these two regions.

ANALYZING ISUAL SPECTROPHOTOMETER DATA USING A TWO-COLOR DIAGRAM METHOD

CHEN ALFRED BING-CHIH,CHIANG PO-SHIH,HUANG TIAN-HSIANG,KUO CHENG-LING,WANG SHI-CHUN,SU HAN-TZONG,HSU RUE-RoN,CHANG MING-HUI,CHANG YEOU-SHIN,LIU TIE-YUE,MENDE STEPHEN B.,FREY HARALD U.,FUKUNISHI HIROSH The Korean Astronomical Society 2005 Journal of The Korean Astronomical Society Vol.38 No.2

Transient luminous events (TLEs; sprites, elves, jets and etc.) are lightning-related optical flashes occurring above thunderstorms. Since the first discovery of sprites in 1989, scientists have learned a great deal about the morphological, spectroscopic and electromagnetic characteristics of TLEs through ground and spacecraft campaigns. However, most of the TLE studies were based on events recorded over US High Plains. To elucidate the possible biasing effects, space-borne observations are needed and have their merits. Imager of sprites and Upper Atmospheric Lightning (ISUAL) on the FORMOSAT-2 satellite is the first instrument to carry out a true global measurement of TLEs from a low- earth orbit. In this short paper, we apply a common astronomical data analysis technique, two-color diagram, on the ISUAL spectrophotometer (SP) data. By choosing appropriated bandpasses and converting the measured flux of TLEs into the unit of magnitude, two-color diagrams of TLEs can be constructed. We demonstrate that two-color diagrams, which were constructed from the narrow-band spectrophotometer data, can be used to classify different types of TLEs and trace their temporal evolution. The amount of reddening due to Earth's atmosphere can also be estimated from two-color diagrams assembled from the broad-band spectrophotometer data.

TELLING A GOOD STORY FROM A BAD COMPANY: EXAMINING THE EFFECTS OF NARRATIVE RICHNESS AND MORAL IMAGINATION ON CONSUMER EMOTIONS, ATTITUDE, AND BEHAVIORAL INTENTION

Po-Han Wu,Kuan-Ju Chen 글로벌지식마케팅경영학회 2023 Global Marketing Conference Vol.2023 No.07

Given the conundrum of moral washing in CSR communication, this research examines the effectiveness of narrative richness using storytelling in marketing. In the process, the moderating role of moral imagination is further explored. An online experiment with a 2 (Narrative Richness: High vs. Low) x 2 (Moral Imagination: High vs. Low) between-subjects factorial design was conducted with two well-known companies (Shell vs. Facebook) suffered from a reputation crisis as the target brands. The results (N = 287) showed that the effects of narrative richness on consumer responses, including positive emotion, negative emotion, and behavioral intention, were significant for Facebook whereas its effect on positive emotion was significant for Shell. Most importantly, the two-way interaction between narrative richness and moral imagination on attitude toward the brand was significant for Shell, indicating that the effect of narrative richness on attitude toward the brand was augmented by moral imagination. In other words, consumers with high moral imagination view narrative-rich messages with virtuous thoughts to figure out the conundrum of CSR communication for the company, and vice versa. Theoretical and managerial implications are discussed.

해저지진계 운영을 통한 영덕 앞바다 미소지진 분석

한민희(Minhui Han),김광희(Kwang-Hee Kim),박순천(Sun-Cheon Park),Pei-ying Lin,Po-Chi Chen,Hsu-Kuang Chang,Jia-pu Jang,Ban-Yuan Kuo 대한지질학회 2016 대한지질학회 학술대회 Vol.2016 No.10

Nerve growth factor upregulates sirtuin 1 expression in cholestasis: a potential therapeutic target

Ming-Shian Tsai,Po-Huang Lee,Cheuk-Kwan Sun,Ting-Chia Chiu,Yu-Chun Lin,I-Wei Chang,Po-Han Chen,Ying-Hsien Kao 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

This study investigated the regulatory role of nerve growth factor (NGF) in sirtuin 1 (SIRT1) expression in cholestatic livers. We evaluated the expression of NGF and its cognate receptors in human livers with hepatolithiasis and the effects of NGF therapy on liver injury and hepatic SIRT1 expression in a bile duct ligation (BDL) mouse model. Histopathological and molecular analyses showed that the hepatocytes of human diseased livers expressed NGF, proNGF (a precursor of NGF), TrkA and p75NTR, whereas only p75NTR was upregulated in hepatolithiasis, compared with non-hepatolithiasis livers. In the BDL model without NGF therapy, p75NTR, but not TrkA antagonism, significantly deteriorated BDL-induced liver injury. By contrast, the hepatoprotective effect of NGF was abrogated only by TrkA and not by p75NTR antagonism in animals receiving NGF therapy. Intriguingly, a positive correlation between hepatic SIRT1 and NGF expression was found in human livers. In vitro studies demonstrated that NGF upregulated SIRT1 expression in mouse livers and human Huh-7 and rodent hepatocytes. Both NGF and proNGF induced protective effects against hydrogen peroxide-induced cytotoxicity in Huh-7 cells, whereas inhibition of TrkA and p75NTR activity prevented oxidative cell death. Mechanistically, NGF, but not proNGF, upregulated SIRT1 expression in human Huh-7 and rodent hepatocytes via nuclear factor (NF)-κB activity, whereas NGF-induced phosphoinositide-3 kinase/Akt, extracellular signal–regulated kinase and NF-κB signaling and SIRT1 activity were involved in its hepatoprotective effects against oxidative injury. These findings suggest that pharmacological manipulation of the NGF/SIRT1 axis might serve as a novel approach for the treatment of cholestatic disease.

The Association between Default-mode Network Functional Connectivity and Childhood Trauma on the Symptom Load in Male Adults with Methamphetamine Use Disorder

Shyh-Yuh Wei,Tsung-Han Tsai,Tsung-Yu Tsai,Po See Chen,Huai-Hsuan Tseng,Yen Kuang Yang,Tianye Zhai,Yihong Yang,Tzu-Yun Wang 대한정신약물학회 2024 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.22 No.1

Objective: The relationship between adverse childhood experiences and methamphetamine use disorder (MUD) has been shown in previous studies; nevertheless, the underlying neural mechanisms remain elusive. Childhood trauma is associated with aberrant functional connectivity (FC) within the default-mode network (DMN). Furthermore, within the DMN, FC may contribute to impaired self-awareness in addiction, while cross-network FC is critical for relapse. We aimed to investigate whether childhood trauma was associated with DMN-related resting-state FC among healthy controls and patients with MUD and to examine whether DMN-related FC affected the effect of childhood trauma on the symptom load of MUD diagnosis. Methods: Twenty-seven male patients with MUD and 27 male healthy controls were enrolled and completed the Childhood Trauma Questionnaire. DMN-related resting-state FC was examined using functional magnetic resonance imaging. Results: There were 47.1% healthy controls and 66.7% MUD patients in this study with adverse childhood experiences. Negative correlations between adverse childhood experiences and within-DMN FC were observed in both healthy controls and MUD patients, while within-DMN FC was significantly altered in MUD patients. The detrimental effects of adverse childhood experiences on MUD patients may be attenuated through DMN-executive control networks (ECN) FC. Conclusion: Adverse childhood experiences were negatively associated with within-DMN FC in MUD patients and healthy controls. However, DMN-ECN FC may attenuate the effects of childhood trauma on symptoms load of MUD.

Infusion of Human Mesenchymal Stem Cells Improves Regenerative Niche in Thioacetamide-Injured Mouse Liver

Kao Ying-Hsien,Lin Yu-Chun,Lee Po-Huang,Lin Chia-Wei,Chen Po-Han,Tai Tzong-Shyuan,Chang Yo-Chen,Chou Ming-Huei,Chang Chih-Yang,Sun Cheuk-Kwan 한국조직공학과 재생의학회 2020 조직공학과 재생의학 Vol.17 No.5

Background: This study investigated whether xenotransplantation of human Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) reduces thioacetamide (TAA)-induced mouse liver fibrosis and the underlying molecular mechanism. Methods: Recipient NOD/SCID mice were injected intraperitoneally with TAA twice weekly for 6 weeks before initial administration of WJ-MSCs. Expression of regenerative and pro-fibrogenic markers in mouse fibrotic livers were monitored post cytotherapy. A hepatic stallate cell line HSC-T6 and isolated WJ-MSCs were used for in vitro adhesion, migration and mechanistic studies. Results: WJ-MSCs were isolated from human umbilical cords by an explant method and characterized by flow cytometry. A single infusion of WJ-MSCs to TAA-treated mice significantly reduced collagen deposition and ameliorated liver fibrosis after 2-week therapy. In addition to enhanced expression of hepatic regenerative factor, hepatocyte growth factor, and PCNA proliferative marker, WJ-MSC therapy significantly blunted pro-fibrogenic signals, including Smad2, RhoA, ERK. Intriguingly, reduction of plasma fibronectin (pFN) in fibrotic livers was noted in MSC-treated mice. In vitro studies further demonstrated that suspending MSCs triggered pFN degradation, soluble pFN conversely retarded adhesion of suspending MSCs onto type I collagen-coated surface, whereas pFN coating enhanced WJ-MSC migration across mimicked wound bed. Moreover, pretreatment with soluble pFN and conditioned medium from MSCs with pFN strikingly attenuated the response of HSC-T6 cells to TGF-β1-stimulation in Smad2 phosphorylation and RhoA upregulation. Conclusion: These findings suggest that cytotherapy using WJ-MSCs may modulate hepatic pFN deposition for a better regenerative niche in the fibrotic livers and may constitute a useful anti-fibrogenic intervention in chronic liver diseases.