118 results on '"Chun-Yu Ho"'
Search Results
2. LINC01296 promotes cancer stemness traits in oral carcinomas by sponging miR-143
- Author
-
Kuang-Yuan Liang, Dennis Chun-Yu Ho, Hsiu-Pin Yang, Pei-Ling Hsieh, Chih-Yuan Fang, Lo-Lin Tsai, Shih-Chi Chao, Chia-Ming Liu, and Cheng-Chia Yu
- Subjects
Original Article ,General Dentistry - Abstract
BACKGROUND/PURPOSE: Emerging evidence has shown that various failures in cancer therapy, such as drug resistance, metastasis, and cancer relapse are attributed to cancer stem cells (CSCs). Also, growing attention has been paid to the regulation of non-coding RNAs in cancer stemness. Here, we aimed to investigate the contribution of LINC01296 in the modulation of oral CSCs. MATERIALS AND METHODS: The phenotypic assays including migration, invasion, and colony-forming abilities were carried out in CSCs of two types of oral cancer cells (SAS and GNM) following the knockdown of LINC01296. In addition, the percentage of cells expressing stemness marker, ALDH1, and drug resistance marker, ABCG2, was examined as well as the self-renewal capacity after silencing of LINC01296. Moreover, a luciferase reporter was used to validate the direct interaction between LINC01296 and miR-143. RESULTS: Our results showed that LINC01296 was significantly overexpressed in oral cancer tissues and positively correlated with stemness markers. The phenotypic and flow cytometry assays demonstrated that suppression of LINC01296 reduced the aggressiveness, cancer stemness features, and colony-forming and self-renewal abilities in oral CSCs. Furthermore, we demonstrated that LINC01296 may enhance cancer stemness features through suppression of the effect of miR-143. CONCLUSION: Silencing of LINC01296 may be a promising direction for oral cancer therapy by reducing cancer stemness via regulation of miR-143.
- Published
- 2023
3. Productivity advantage of large cities for creative industries
- Author
-
Chun‐Yu Ho and Yue Sheng
- Subjects
Geography, Planning and Development ,Environmental Science (miscellaneous) - Published
- 2022
4. Price Negotiation with Merchant Heterogeneity in the Payment Card Industry
- Author
-
Li Xu, Chun-Yu Ho, and Daiqiang Zhang
- Subjects
Economics and Econometrics ,Negotiation ,Variation (linguistics) ,media_common.quotation_subject ,0502 economics and business ,05 social sciences ,Payment card industry ,Business ,050207 economics ,Social Sciences (miscellaneous) ,Industrial organization ,050205 econometrics ,media_common - Abstract
We examine price negotiation in the payment card industry by exploiting a unique merchant-, industry-, and city-level data set. Motivated by the substantial variation in acquirer fees and heterogeneous merchant card transactions, we use Nash bargaining to model the negotiation over the acquirer fee between an acquirer and a merchant. We find that the merchants secure a larger incremental surplus than the acquirer on average. Moreover, merchants might face upward pressure on acquirer fees as the card penetration rate rises over time, and policies that weaken the acquirer's bargaining power could relieve the upward fee pressure.
- Published
- 2022
5. Internal and external reference dependence of incomplete contracts: Experimental evidences
- Author
-
Jun Feng, Xiangdong Qin, and Chun-Yu Ho
- Subjects
Organizational Behavior and Human Resource Management ,Economics and Econometrics - Published
- 2022
6. Promoting Mobile Payment with Price Incentives
- Author
-
Chun-Yu Ho, Nayoung Kim, Ying Rong, and Xin Tian
- Subjects
Strategy and Management ,ComputingMilieux_COMPUTERSANDSOCIETY ,TheoryofComputation_GENERAL ,Management Science and Operations Research - Abstract
Using a proprietary data set containing more than 10 million transactions over 14 months from hundreds of grocery stores, we examine consumer payment choices at point of sale (POS) between cash and mobile, where the use of other methods (including cards) is minimal. We find that cash is the dominant method of payment. Nonetheless, the share of mobile payments has increased at the expense of cash payments over time. Importantly, we exploit price incentives for consumers using mobile payment to examine the price substitution between cash and mobile payments. Our results show that consumers are more likely to use mobile payment when they receive price incentives for doing so, and such an effect persists for a few days, even after the price incentive expires. Nonetheless, the price incentives are unlikely financed by additional transactions paid via mobile but subsidized by mobile payment providers. Interestingly, we find several factors that enhance and supplement the steering effect of price incentives. First, a larger monetary reward seems to induce a stronger impact of price incentive on mobile payment. Second, the steering effect of price incentive is stronger for stores that serve consumers who have frequently been using mobile payment and for price-sensitive consumers. Third, the additional mobile payments come from transactions that would not have occurred with price incentive and those that switch from cash transactions. This paper was accepted by Eric Anderson, marketing.
- Published
- 2022
7. Digitalization and firm performance: channels and heterogeneities
- Author
-
Ruonan Cheng, Chun-Yu Ho, and Shaoqing Huang
- Subjects
Economics and Econometrics - Published
- 2022
8. Our Voyage from Catalytic Cross-Hydroalkenylation to Transfer-Dehydroaromatization of Cyclic π-Systems: Reactivity and Selectivity Changes Enabled by NHC-Ni and NHC-Pd Hydride Equivalents
- Author
-
Chun-Yu Ho, Weihao Chen, Yang Chen, and Xiao Gu
- Subjects
Organic Chemistry - Abstract
N-Heterocyclic carbene ligated transition-metal catalysts often show interesting properties and reactivity as compared to conventional ligand systems. In (NHC)Ni and (NHC)Pd hydrides, a dramatic reactivity changed from cross-hydroalkenylation to transfer-dehydroaromatization was observed under optimized conditions. This account summarizes our recent efforts and stories behind this serendipitous discovery. The mechanistic studies revealed that the keys to divert the desired reactivity are the differences in the olefin insertion selectivity and the hydrometallated species reactivity.
- Published
- 2023
9. Obstetric Unit Closures and Racial/Ethnic Disparity in Health
- Author
-
Pinka Chatterji, Chun-Yu Ho, and Xue Wu
- Published
- 2023
10. Banking Crisis, Venture Capital and Innovation
- Author
-
Won Sung and Chun-Yu Ho
- Subjects
History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2023
11. Honokiol inhibits arecoline-induced oral fibrogenesis through transforming growth factor-β/Smad2/3 signaling inhibition
- Author
-
Kai Hsi Lu, Cheng Chia Yu, Lo Lin Tsai, Pei-Ling Hsieh, Yi Wen Liao, Sheng Hua Su, Dennis Chun Yu Ho, and Pei-Yin Chen
- Subjects
Honokiol ,Medicine (General) ,Arecoline ,Smad2 Protein ,Lignans ,03 medical and health sciences ,chemistry.chemical_compound ,R5-920 ,0302 clinical medicine ,Humans ,Medicine ,Areca ,biology ,business.industry ,Biphenyl Compounds ,Mouth Mucosa ,General Medicine ,Fibroblasts ,Oral submucous fibrosis ,biology.organism_classification ,medicine.disease ,Magnolia officinalis ,chemistry ,Transforming Growth Factors ,030220 oncology & carcinogenesis ,Cell Transdifferentiation ,Cancer research ,030211 gastroenterology & hepatology ,business ,Wound healing ,Myofibroblast ,Type I collagen ,Buccal mucosal fibroblasts ,Transforming growth factor ,medicine.drug - Abstract
Background/purpose The habit of areca nut chewing has been regarded as an etiological factor of precancerous oral submucous fibrosis (OSF). In the present study, we aimed to evaluate the anti-fibrosis effect of honokiol, a polyphenolic component derived from Magnolia officinalis. Methods The cytotoxicity of honokiol was tested using normal and fibrotic buccal mucosal fibroblasts (fBMFs) derived from OSF tissues. Collagen gel contraction, Transwell migration, invasion, and wound healing capacities were examined. Besides, the expression of TGF-β/Smad2 signaling as well as α–SMA and type I collagen were measured as well. Results Honokiol exerted higher cytotoxicity of fBMFs compared to normal cells. The arecoline-induced myofibroblast activities, including collagen gel contractility, cell motility and wound healing capacities were all suppressed by honokiol treatment. In addition, the expression of the TGF-β/Smad2 pathway was downregulated along with a lower expression of α–SMA and type I collagen in honokiol-receiving cells. Conclusion Our data suggest that honokiol may be a promising compound to alleviate the progression of oral fibrogenesis and prevent the transformation of OSF oral epithelium into cancer.
- Published
- 2021
12. NHC-Ni(II)-catalyzed cyclopropene-isocyanide [5 + 1] benzannulation
- Author
-
Jian–Qiang Huang, Meng Yu, Xuefeng Yong, and Chun–Yu Ho
- Subjects
Multidisciplinary ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Abstract
Isocyanides are common compounds in fine and bulk chemical syntheses. However, the direct addition of isocyanide to simple unactivated cyclopropene via transition metal catalysis is challenging. Most of the current approaches focus on 1,1-insertion of isocyanide to M-R or nucleophilc insertion. That is often complicated by the competitive homo-oligomerization reactivity occurring at room temperature, such as isocyanide 1,1-insertion by Ni(II). Here we show a (N-heterocyclic carbene)Ni(II) catalyst that enables cyclopropene-isocyanide [5 + 1] benzannulation. As shown in the broad substrate scope and a [trans-(N-heterocyclic carbene)Ni(isocyanide)Br2] crystal structure, the desired cross-reactivity is cooperatively controlled by the high reactivity of the cyclopropene, the sterically bulky N-heterocyclic carbene, and the strong coordination ability of the isocyanide. This direct addition strategy offers aromatic amine derivatives and complements the Dötz benzannulation and Semmelhack/Wulff 1,4-hydroquinone synthesis. Several sterically bulky, fused, and multi-substituted anilines and unsymmetric functionalized spiro-ring structures are prepared from those easily accessible starting materials expediently.
- Published
- 2022
13. Diastereodivergent Hydrosilylative Enyne Cyclization Catalyzed by <scp> N ‐Heterocyclic Carbene‐Ni </scp> (0) †
- Author
-
Xuefeng Yong, Meng Yu, Chun-Yu Ho, and Weiwei Gao
- Subjects
chemistry.chemical_compound ,Nickel ,Enyne ,Chemistry ,Hydrosilylation ,chemistry.chemical_element ,General Chemistry ,Carbene ,Medicinal chemistry ,Catalysis - Published
- 2021
14. NHC‐Ni(0) Catalyzed Diastereodivergent Hydroacylative Enyne Cyclization: Synthesis of Heterocycles bearing γ‐Enone
- Author
-
Zibo Zhen, Chun-Yu Ho, Xuefeng Yong, Xiulian Lin, Weiwei Gao, and Elvis Wang Hei Ng
- Subjects
Acylation ,chemistry.chemical_compound ,Nickel ,Bearing (mechanical) ,chemistry ,Enyne ,law ,chemistry.chemical_element ,General Chemistry ,Medicinal chemistry ,Enone ,law.invention ,Catalysis - Published
- 2020
15. NHC/Nickel(II)‐Catalyzed [3+2] Cross‐Dimerization of Unactivated Olefins and Methylenecyclopropanes
- Author
-
Jian-Qiang Huang and Chun-Yu Ho
- Subjects
chemistry.chemical_classification ,010405 organic chemistry ,Alkene ,Convergent synthesis ,Regioselectivity ,General Chemistry ,010402 general chemistry ,Methylenecyclopropane ,01 natural sciences ,Medicinal chemistry ,Oxidative addition ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Reactivity (chemistry) ,Carbene - Abstract
Cross-dimerization of a methylenecyclopropane (1) and an unactivated alkene (2) with typical hydroalkenylation reactivity was observed for the first time by using a [NHC-Ni(allyl)]BArF catalyst (NHC=N-heterocyclic carbene). Results show that the C-C cleavage of 1 did not involve a Ni0 oxidative addition, which was crucial in former systems. Thus the method reported here emerges as a complementary method for attaining highly chemo- and regioselective synthesis of methylenecyclopentanes (3) with broad scope. An efficient NHC/NiII -catalyzed rearrangement of 1 leads to the convergent synthesis of 3 in the presence of 2.
- Published
- 2020
16. NHC/Nickel(II)‐Catalyzed [3+2] Cross‐Dimerization of Unactivated Olefins and Methylenecyclopropanes
- Author
-
Jian‐Qiang Huang and Chun‐Yu Ho
- Subjects
General Medicine - Published
- 2020
17. (NHC)Pd(II) hydride-catalyzed dehydroaromatization by olefin chain-walking isomerization and transfer-dehydrogenation
- Author
-
Weihao Chen, Yang Chen, Xiao Gu, Zaizhu Chen, and Chun-Yu Ho
- Subjects
Multidisciplinary ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Abstract
Transition-metal-catalyzed homogeneous dehydrogenation and isomerization are common organic molecular activation reactions. Palladium hydrides are good olefin isomerization catalysts but are usually short-lived species under redox-active dehydrogenation conditions. Here, we show that Pd-H in the presence of an N-heterocyclic carbene ligand and an alkene regulator enables transfer-dehydroaromatization, avoiding the homo-disproportionation pathway. The desired product is obtained with up to 99:1 selectivity, and the exo-to-endo olefin isomerization can be carried out in one pot. In contrast to previously reported methods that rely on the efficient removal of Pd-H, the approach reported herein benefits from the steric effects of the N-heterocyclic carbene and the choice of alkene to regulate the competing reactivity of allylic C‒H activation and hydropalladation. This method circumvents the challenges associated with tedious olefin separation and a low exo-to-endo olefin isomerization ratio and expands the scope to include challenging endo- and exo-cyclic olefins under mild, neutral, and oxidant-free conditions. Overall, herein, we provide a strategy to synthesize (hetero)aromatic compounds via chemoselective dehydrogenation of cyclic alkenes over ketones and the dehydrogenative Diels-Alder reaction of a cyclic enamine.
- Published
- 2022
18. Down-regulation of miR-29c promotes the progression of oral submucous fibrosis through targeting tropomyosin-1
- Author
-
Po-Yu Yang, Yi Wen Liao, Chih Yuan Fang, Pei-Ling Hsieh, Lo Lin Tsai, Szu Han Chen, Dennis Chun Yu Ho, and Cheng Chia Yu
- Subjects
business.industry ,Transdifferentiation ,Down-Regulation ,Oral Submucous Fibrosis ,General Medicine ,Tropomyosin ,medicine.disease ,Contractility ,Precancerous condition ,MicroRNAs ,Downregulation and upregulation ,Oral submucous fibrosis ,microRNA ,Cancer research ,medicine ,Humans ,business ,Myofibroblasts ,Myofibroblast - Abstract
Background/Purpose Various microRNAs (miRs) have been found to be associated with the development of the precancerous condition of the oral cavity, oral submucous fibrosis (OSF). The expression of miR-29c is dysregulated in oral cancer, but its role in OSF has not been investigated. The purpose of the study is to investigate the functional role of miR-29c and its target in OSF. Methods The expression levels of miR-29c in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs) were assessed using next-generation sequencing and real-time Polymerase Chain Reaction (PCR) analysis. MiR-29c mimic and inhibitors were employed to examine its functional role of myofibroblast transdifferentiation. In addition, several myofibroblast phenotypes, such as collagen gel contraction and migration were tested, and a luciferase reporter assay was conducted to confirm the relationship between miR-29c and its predicted target, tropomyosin-1 (TPM1). Results We observed that miR-29c expression was downregulated in fBMFs. fBMFs transfected with miR-29c mimics exhibited reduced migration ability and collagen gel contractility, whereas inhibition of miR-29c in normal BMFs induced the myofibroblast phenotypes. Results from the luciferase reporter assay showed that TPM1 was a direct target of miR-29c and the expression of TPM1 was suppressed in the fBMFs transfected with miR-29c mimics. Besides, we confirmed that the expression of miR-29c was indeed downregulated in OSF specimens. Conclusion MiR-29c seems to exert an inhibitory effect on myofibroblast activation, such as collagen gel contractility and migration ability, via suppressing TPM1. These results suggested that approaches to upregulate miR-29c may be able to ameliorate the progression of OSF.
- Published
- 2021
19. Monetary policy surprises and interest rates under China's evolving monetary policy framework
- Author
-
Liang Fu and Chun-Yu Ho
- Subjects
Economics and Econometrics ,Business and International Management - Published
- 2022
20. Paeonol inhibits profibrotic signaling and HOTAIR expression in fibrotic buccal mucosal fibroblasts
- Author
-
Dennis Chun Yu Ho, Chang-Wei Hsieh, Cheng Chia Yu, Lo Lin Tsai, Yi Wen Liao, Szu Han Chen, Chih Yuan Fang, and Pei-Ling Hsieh
- Subjects
Arecoline ,Motility ,Oral Submucous Fibrosis ,Collagen Type I ,chemistry.chemical_compound ,Transforming Growth Factor beta ,medicine ,Humans ,Areca ,Cells, Cultured ,biology ,business.industry ,Paeonia suffruticosa ,Mouth Mucosa ,Acetophenones ,HOTAIR ,General Medicine ,Fibroblasts ,medicine.disease ,biology.organism_classification ,Fibrosis ,Oral submucous fibrosis ,chemistry ,Cell Transdifferentiation ,Cancer research ,Paeonol ,Wound healing ,business ,Myofibroblast ,Type I collagen - Abstract
Background/purpose Betel nut chewing is the major risk factor of oral submucous fibrosis (OSF). Various studies have sought to discover alternative strategies to alleviate oral fibrogenesis. In the present study, we aimed to evaluate the anti-fibrosis effect of paeonol, a phenolic component derived from Paeonia Suffruticosa. Methods The cytotoxicity of paeonol was tested using normal and fibrotic buccal mucosal fibroblasts (fBMFs) derived from OSF tissues. Collagen gel contraction, Transwell migration, invasion, and wound healing capacities were examined. Besides, the activation of TGF-β/Smad2 signaling and expression levels of type I collagen, α-SMA, and long non-coding RNA HOTAIR were measured as well. Results Paeonol exerted a higher cytotoxic effect on fBMFs compared to normal BMFs. The arecoline-induced myofibroblast activities, including collagen gel contractility, cell motility, and wound healing ability were all suppressed by paeonol treatment. In addition, the activation of the TGF-β/Smad2 pathway was inhibited along with a lower expression of α-SMA and type I collagen in paeonol-treated cells. Also, the administration of paeonol decreased the mRNA expression of HOTAIR in fBMFs. Conclusion Our results indicate that paeonol may be a promising compound to attenuate the progression of oral fibrogenesis in OSF patients.
- Published
- 2021
21. Heterogeneous effects of internet channel on firm innovation
- Author
-
Bin Li and Chun-Yu Ho
- Subjects
Economics and Econometrics ,050208 finance ,Internet channel ,business.industry ,0502 economics and business ,05 social sciences ,New product development ,Business ,E-commerce ,050207 economics ,Threshold model ,Commercialization ,Industrial organization - Abstract
This paper examines the effects of Internet channel on the commercialization of firm innovation, which is measured by new product sales (NPS). We estimate our empirical model with the GMM-threshold...
- Published
- 2019
22. Electronic Effects on Chiral NHC–Transition-Metal Catalysis
- Author
-
Ryan Thurston, Chun-Yu Ho, and Xuefeng Yong
- Subjects
Steric effects ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Enantioselective synthesis ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Molecular geometry ,Transition metal ,Computational chemistry ,Improvement methods ,Electronic effect ,Chiral induction - Abstract
Though the properties of N-heterocyclic carbenes (NHCs) are generally dominated by the very strong σ donating character, electronic activation has emerged as an effective method to cooperate with typical carbon-framework steric optimization for highly enantioselective chiral NHC–transition-metal catalysis in recent years. NHC electronic changes associated with structural variations are now better understood by quantitative analysis using various methods. Here we highlighted and correlated some interesting chiral induction improvement methods, which were brought by electronic and steric cooperation on chiral NHC–transition-metal catalysis.1 Introduction2 Hemilabile Sidechains on NHC Ligands3 Electronic and Bond Angle Changes Brought by NHC Core Size Variations4 Electronic Activators on the NHC Core5 Conjugated Systems and Fused Ring Structures6 Remote Electronic Activators on the N-Aryl Ring7 Summary and Outlook
- Published
- 2019
23. [(NHC)Ni II H]‐Catalyzed Cross‐Hydroalkenylation of Cyclopropenes with Alkynes: Cyclopentadiene Synthesis by [(NHC)Ni II ]‐Assisted C−C Rearrangement
- Author
-
Jian-Qiang Huang and Chun-Yu Ho
- Subjects
chemistry.chemical_classification ,Cyclopentadiene ,Diene ,010405 organic chemistry ,Alkyne ,chemistry.chemical_element ,General Chemistry ,Cyclopropene ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,Nickel ,chemistry ,Vinylcyclopropane rearrangement ,Reactivity (chemistry) - Abstract
A cross-hydroalkenylation/rearrangement cascade (HARC), using a cyclopropene and alkyne as substrate pairs, was achieved for the first time by using new [(NHC)Ni(allyl)]BArF catalysts (NHC=N-heterocyclic carbenes). By controlling the (NHC)NiII H relative insertion reactivity with cyclopropene and alkyne, a broad scope of cyclopentadienes was obtained with highly selectively. The structural features of the new (NHC)NiII catalyst were important for the success of the reaction. The mild reaction conditions employed may serve as an entry for exploring (NHC)NiII -assisted vinylcyclopropane rearrangement reactivity.
- Published
- 2019
24. [(NHC)Ni II H]‐Catalyzed Cross‐Hydroalkenylation of Cyclopropenes with Alkynes: Cyclopentadiene Synthesis by [(NHC)Ni II ]‐Assisted C−C Rearrangement
- Author
-
Jian‐Qiang Huang and Chun‐Yu Ho
- Subjects
General Medicine - Published
- 2019
25. Partners or rivals? An experimental study of a two-stage tournament
- Author
-
Hong Chao, Jiajia Cong, Shaoqing Huang, Xiangdong Qin, and Chun-Yu Ho
- Subjects
Organizational Behavior and Human Resource Management ,Economics and Econometrics ,Matching (statistics) ,05 social sciences ,Investment (macroeconomics) ,Test (assessment) ,Microeconomics ,Appropriation ,Incentive ,Alliance ,0502 economics and business ,050206 economic theory ,Tournament ,Business ,050207 economics ,Hold-up problem - Abstract
We consider a two-stage tournament in which two alliances compete in stage one. Members of the winning alliance then compete against each other in stage two. Members’ investment in stage one could increase their alliance's winning probability, but could also be appropriated and used against them by their partners-turned-rivals in stage two. This hold-up problem creates a negative incentive for within-alliance cooperation. We test this theoretical benchmark in an experiment. In a second experiment, we investigate whether ex-ante informal agreements deter appropriation. We find that such agreements are honored, and thus encourage investments, only under the fixed matching condition.
- Published
- 2019
26. Synthesis and study of Au(<scp>iii</scp>)–indolizine derivatives: turn-on luminescence by photo-induced controlled release
- Author
-
Yang Chen, Yu Chung Tse, Keith Man-Chung Wong, Anfernee Kai-Wing Tse, Chun-Yu Ho, Xinghua Zhou, Jie Yang, and Yifan Zhu
- Subjects
010405 organic chemistry ,Metals and Alloys ,General Chemistry ,Bond formation ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Controlled release ,Catalysis ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Turn (biochemistry) ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Indolizine ,Luminescence - Abstract
The photo- and structural properties of a series of Au(iii) indolizine complexes were determined. Controlled release of halogenated indolizine derivatives from the corresponding Au(iii) complexes was achieved by photoinduced C-X bond formation, which provided turn-on luminescence with an increase in emission intensity of up to 67 times.
- Published
- 2019
27. Extraction with an electric motor-driven handpiece may still cause subcutaneous emphysema - A case report
- Author
-
Bo Jen Chiou, Dennis Chun Yu Ho, Shan Ju Chou, and Chih Yuan Fang
- Subjects
Subcutaneous emphysema ,Electric motor ,business.industry ,Extraction (chemistry) ,Extraction complication ,RK1-715 ,Dental iatrogenic disease ,Dentistry ,Correspondence ,Dental High-Speed Equipment ,Medicine ,Dental high-speed equipment ,medicine.symptom ,business ,General Dentistry ,Biomedical engineering - Published
- 2021
28. NHC-Ni catalyzed 1,3- and 1,4-diastereodivergent heterocycle synthesis from hetero-substituted enyne
- Author
-
Xuefeng Yong, Chun-Yu Ho, Weiwei Gao, and Xiulian Lin
- Subjects
Steric effects ,Enyne ,Silylation ,010405 organic chemistry ,Chemistry ,Diastereomer ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,0104 chemical sciences ,Catalysis ,Stereocenter ,lcsh:Chemistry ,Acylation ,lcsh:QD1-999 ,Materials Chemistry ,Environmental Chemistry ,Selectivity - Abstract
Diastereodivergent heterocycle synthesis has been recognized as an important tool for drug discovery in recent years, yet strategies based on nickelacycle formation have not been established. Here, we report a NHC-Ni catalyzed highly 1,3- and 1,4-diastereodivergent heterocycle synthesis from enyne, which is achieved by manipulating the enyne N-substituent (allowing switching of selectivity from up to 2:98 to 98:2). The key to success is the efficient diastereodivergent formation of a nickelacyclopentene, with broad enyne scope at mild conditions, which subsequently provides reductive hydroalkenylation, acylation and silylation products on demand. Diastereoisomers which are sterically hard to distinguish or difficult to access by conventional routes are now accessible easily, including those with very similar 4°, contiguous and skipped stereocenters. Diastereoselective cyclisation of heteroatom-substituted enynes offers a valuable route to bioactive heterocycles. Here, a diastereodivergent nickel-catalysed cyclisation of heteroenynes offers access to diastereomers of 1,3- and 1,4-hydroalkenylation products, controlled by the choice of substituents.
- Published
- 2020
29. Financial deepening and innovation: The role of political institutions
- Author
-
Hao Shi, Jun Wu, Shaoqing Huang, and Chun-Yu Ho
- Subjects
Economics and Econometrics ,050208 finance ,Sociology and Political Science ,media_common.quotation_subject ,05 social sciences ,Geography, Planning and Development ,Development ,Democracy ,Financial deepening ,Politics ,Market economy ,0502 economics and business ,Openness to experience ,Economics ,Stock market ,Democratization ,050207 economics ,Stock (geology) ,Panel data ,media_common - Abstract
This study investigates the effects of financial deepening on innovation for various democratic levels of political institutions using panel data from 74 countries spanning 1970–2010. Our results show that banking market deepening is associated with increased innovation only when political institutions are sufficiently democratic. In contrast, the enhancing effect of stock market deepening on innovation requires a lower level of political democracy. Further, we find that increasing the state's openness and competitiveness in the executive recruitment of leaders is the main channel through which political democratization promotes the role of banking and stock markets for financing innovation. Our results are robust to the use of the instrumental variable approach; alternative measures for financial deepening, democracy and innovation input; long-differenced variables; and alternative specifications.
- Published
- 2018
30. miR-145 mediates the anti-cancer stemness effect of photodynamic therapy with 5-aminolevulinic acid (ALA) in oral cancer cells
- Author
-
Dennis Chun Yu Ho, Pei-Ling Hsieh, Chuan Hang Yu, Chih Yuan Fang, Pei-Yin Chen, Lo Lin Tsai, Cheng Chia Yu, and Ming Yi Lu
- Subjects
0301 basic medicine ,medicine.medical_treatment ,Photodynamic therapy ,03 medical and health sciences ,0302 clinical medicine ,Downregulation and upregulation ,Cancer stem cell ,Cell Line, Tumor ,medicine ,Adjuvant therapy ,Humans ,lcsh:R5-920 ,Photosensitizing Agents ,biology ,business.industry ,CD44 ,Head and neck cancer ,Cancer ,Aminolevulinic Acid ,General Medicine ,medicine.disease ,MicroRNAs ,Hyaluronan Receptors ,030104 developmental biology ,Photochemotherapy ,030220 oncology & carcinogenesis ,Cancer cell ,Neoplastic Stem Cells ,biology.protein ,Cancer research ,Mouth Neoplasms ,lcsh:Medicine (General) ,business - Abstract
5-Aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) has been used in the treatment of various precancerous and malignant lesions. Our previous work has demonstrated that ALA-PDT possesses the potential to serve as an adjuvant therapy against head and neck cancer via eliminating the cancer stem cells (CSCs) property. This study aimed to further investigate the possible molecular mechanism underlying the effect of ALA-PDT. Our results revealed that ALA-PDT upregulated the expression of microRNA-145 (miR-145) in two oral cancer cell lines. Overexpression of miR-145 in oral CSCs further enhanced the treatment effect of ALA-PDT with lower self-renewal, invasion capacities and reduced CD44 expression, while inhibition of miR-145 exhibited the opposite phenomena. These findings suggest that the anti-CSCs effect of ALA-PDT is due to an elevation of miR-145. Keywords: 5-Aminolevulinic acid-mediated photodynamic therapy, Oral cancer stem cells, microRNA-145
- Published
- 2018
31. (NHC)NiH-Catalyzed Regiodivergent Cross-Hydroalkenylation of Vinyl Ethers with α-Olefins: Syntheses of 1,2- and 1,3-Disubstituted Allyl Ethers
- Author
-
Yang Chen, Chun-Yu Ho, Weihao Chen, and Yang Li
- Subjects
Steric effects ,010405 organic chemistry ,Ether ,General Medicine ,General Chemistry ,Vinyl ether ,010402 general chemistry ,01 natural sciences ,Acceptor ,Medicinal chemistry ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Electronic effect ,medicine ,Chemoselectivity ,Carbene ,medicine.drug - Abstract
Cross-hydroalkenylation of a vinyl ether (1) with an α-olefin (2) was first achieved by a set of [NHC-Ni(allyl)]BArF (NHC=N-heterocyclic carbene) catalysts. Both 1,2- and 1,3-disubstituted allyl ethers were obtained, highly selectively, by using NHCs of different sizes. In contrast, the chemoselectivity (i.e., 1 as acceptor and 2 as donor) was controlled mostly by electronic effects through the catalyst-substrate interaction. Sterically bulkier alkenes (2) were used as preferred donors compared to smaller alkenes. This electronic effect also served as a basis for the first tail-to-head cross-hydroalkenylations of 1 with either a vinyl silane or boronic ester.
- Published
- 2018
32. International knowledge spillover through trade: A time-varying spatial panel data approach
- Author
-
Wei Wang, Chun-Yu Ho, and Jihai Yu
- Subjects
Economics and Econometrics ,05 social sciences ,Sample (statistics) ,International economics ,Knowledge spillover ,Knowledge production ,Term (time) ,Bilateral trade ,Spillover effect ,Autoregressive model ,0502 economics and business ,Econometrics ,Economics ,050207 economics ,Finance ,050205 econometrics ,Panel data - Abstract
This paper empirically examines international knowledge spillover through bilateral trade. We extend the knowledge production function using a spatial autoregressive term and time-varying weights matrices, and we estimate this model using a sample of 30 countries over the period 1975–2010. We find that there is a positive spillover effect of innovation from one country to its trade partners through bilateral import flows. The spillover effect accounts for approximately 1.3%–3.6% of the total effect of R&D input on innovation output over time.
- Published
- 2018
33. Ex Vivo Expanded Circulating Tumor Cells for Clinical Anti-Cancer Drug Prediction in Patients with Head and Neck Cancer
- Author
-
Kuan-Chou Lin, Peng-Yuan Wang, Ching-Zong Wu, Chang-Yu Chen, Kai-Chiang Yang, Hsin-Lun Lee, Dennis-Chun-Yu Ho, Fang-Chi Hsu, Lai-Lei Ting, Thierry Burnouf, Jeng-Fong Chiou, Chia-Lun Chang, Chu-Huang Chen, Yin Ju Chen, and Long Sheng Lu
- Subjects
Oncology ,Drug ,Cancer Research ,medicine.medical_specialty ,media_common.quotation_subject ,medicine.medical_treatment ,circulating tumor cells ,Article ,Circulating tumor cell ,response to therapy ,Internal medicine ,medicine ,In patient ,Ex vivo expansion ,drug sensitivity ,RC254-282 ,media_common ,Cisplatin ,Chemotherapy ,business.industry ,ex vivo expansion ,head and neck cancer ,Head and neck cancer ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,medicine.disease ,business ,Ex vivo ,medicine.drug - Abstract
Simple Summary The conventional methods that seek to predict clinical treatment response are based on the number of circulating tumor cells (CTCs) present in liquid biopsies or genetic profiling of extracted CTCs. This paper presents a novel process by which CTCs can be extracted from blood samples taken from head and neck cancer patients and then expanded ex vivo to form organoids that can be tested with a panel of anti-cancer treatments. The resulting drug sensitivity profiles derived from cisplatin treatment of organoids were subsequently found to correlate with clinical treatment response to cisplatin in patients. CTCs extracted from liquid biopsies for ex vivo expansion negates the need for complicated and potentially risky biopsies of tumor material, thereby supporting the application of this procedure for checkups and treatment monitoring. Abstract The advanced-stage head and neck cancer (HNC) patients respond poorly to platinum-based treatments. Thus, a reliable pretreatment method for evaluating platinum treatment response would improve therapeutic efficiency and outcomes. This study describes a novel strategy to predict clinical drug responses in HNC patients by using eSelect, a lab-developed biomimetic cell culture system, which enables us to perform ex vivo expansion and drug sensitivity profiling of circulating tumor cells (CTCs). Forty liquid biopsies were collected from HNC patients, and the CTCs were expanded ex vivo using the eSelect system within four weeks. Immunofluorescence staining confirmed that the CTC-derived organoids were positive for EpCAM and negative for CD45. Two illustrative cases present the potential of this strategy for evaluating treatment response. The statistical analysis confirmed that drug sensitivity in CTC-derived organoids was associated with a clinical response. The multivariant logistic regression model predicted that the treatment accuracy of chemotherapy responses achieved 93.75%, and the area under the curves (AUCs) of prediction models was 0.8841 in the whole dataset and 0.9167 in cisplatin specific dataset. In summary, cisplatin sensitivity profiles of patient-derived CTCs expanded ex vivo correlate with a clinical response to cisplatin treatment, and this can potentially underpin predictive assays to guide HNC treatments.
- Published
- 2021
34. To root or not to root? The economics of jailbreak
- Author
-
Hong Chao, Travis Ng, Tin Cheuk Leung, and Chun-Yu Ho
- Subjects
Economics and Econometrics ,Root (linguistics) ,ComputerSystemsOrganization_COMPUTERSYSTEMIMPLEMENTATION ,Computer science ,05 social sciences ,Demand estimation ,Construct (python library) ,Computer security ,computer.software_genre ,Phone ,0502 economics and business ,Computer software ,050211 marketing ,050207 economics ,Android (operating system) ,Market share ,computer - Abstract
We construct a structural model that allows us to jointly estimate the demand for smartphones and paid apps using a Bayesian approach. Our data comes from more than 500 college students in Hong Kong and Shanghai. We find that the utility cost rather than the upfront monetary cost of jailbreaking smartphones determines its prevalence. Users mainly jailbreak smartphones to use paid apps for free, a reason more important among Android users than iPhone users. Paid apps contribute the lion’s share of the profits (between 66% and 59%) for both the Android and iPhone. Strictly prohibiting jailbreaking would decrease the aggregate market share of smartphones in the cell phone market. Apple, however, would sell even more iPhones at the expense of Android smartphones.
- Published
- 2017
35. A clinically validated prediction method for facial soft‐tissue changes following double‐jaw surgery
- Author
-
Dennis Chun Yu Ho, Xiaobo Zhou, Shunyao Shen, Michael A. K. Liebschner, Guangming Zhang, Daeseung Kim, Siting Liu, Peng Yuan, Steve Guofang Shen, Jaime Gateno, Huaming Mai, James J. Xia, and Xiaoyan Zhang
- Subjects
medicine.medical_specialty ,Jaw Surgery ,Computer science ,medicine.medical_treatment ,Orthognathic surgery ,Mandible ,Article ,03 medical and health sciences ,Imaging, Three-Dimensional ,0302 clinical medicine ,Maxilla ,medicine ,Humans ,Computer Simulation ,Retrospective Studies ,Orthognathic Surgical Procedures ,Soft tissue ,030206 dentistry ,General Medicine ,Chin ,Finite element method ,Surgery ,Constraint (information theory) ,medicine.anatomical_structure ,Face ,030220 oncology & carcinogenesis ,Face (geometry) ,Biomedical engineering - Abstract
Purpose It is clinically important to accurately predict facial soft tissue changes prior to orthognathic surgery. However, the current simulation methods are problematic, especially in anatomic regions of clinical significance, e.g., the nose, lips and chin. We developed a new 3-stage finite element method (FEM) approach that incorporates realistic tissue sliding to improve such prediction. Methods In Stage One, soft-tissue-change was simulated using FEM with patient-specific mesh models generated from our previously developed eFace template. Postoperative bone movement was applied on the patient mesh model with standard FEM boundary conditions. In Stage Two, the simulation was improved by implementing sliding effects between gum tissue and teeth using a nodal force constraint scheme. In Stage Three, the result of the tissue sliding effect was further enhanced by reassigning the soft tissue-bone mapping and boundary conditions using nodal spatial constraint. Finally, our methods have been quantitatively and qualitatively validated using 40 retrospectively evaluated patient cases by comparing it to the traditional FEM method and the FEM with sliding effect using a nodal force constraint method. Results The results showed that our method was better than the other two methods. Using our method, the quantitative distance errors between predicted and actual patient surfaces for the entire face and any sub-regions thereof were below 1.5 mm. The overall soft tissue change prediction was accurate to within 1.1 ± 0.3 mm, with the accuracy around the upper and lower lip regions of 1.2 ± 0.7 mm and 1.5 ± 0.7 mm, respectively. The results of qualitative evaluation completed by clinical experts showed an improvement of 46% in acceptance rate compared to the traditional FEM simulation. More than 80% of the result of our approach was considered acceptable in comparison with 55% and 50% following the other two methods. Conclusion The FEM simulation method with improved sliding effect showed significant accuracy improvement in the whole face and the clinically significant regions (i.e., nose and lips) in comparison with the other published FEM methods, with or without sliding effect using a nodal force constraint. The qualitative validation also proved the clinical feasibility of the developed approach. This article is protected by copyright. All rights reserved.
- Published
- 2017
36. Heterogeneous effects of trade liberalisation on firm-level markups: Evidence from China
- Author
-
Wen Yue, Feixiang Chen, Xunyong Xiang, and Chun-Yu Ho
- Subjects
Sample selection ,Economics and Econometrics ,Liberalization ,05 social sciences ,Instrumental variable ,Tariff reduction ,Tariff ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Monetary economics ,Microeconomics ,Accounting ,0502 economics and business ,Political Science and International Relations ,Economics ,Endogeneity ,050207 economics ,China ,Finance ,050205 econometrics - Abstract
This paper analyses how trade liberalisation affects the markups of Chinese firms based on firm-level production data, highly disaggregated transaction-level product trade data and tariff data at the eight-digit Harmonised System (HS) level. Our results show that there is a pro-competition effect of output tariff reduction, that is decreasing output tariffs relate to a lower markup, and that there is a cost-reduction effect of input tariff reduction, that is decreasing input tariffs relate to a higher markup. Interestingly, there are heterogeneous effects of trade liberalisation on firm-level markups. The cost-reduction effect of input tariff reduction is partially offset by the competition effect of new firm entry in more-concentrated industries. Furthermore, there is a weaker effect of trade liberalisation on processing trade firms and state-owned enterprises. Finally, our results are robust to the use of an instrumental variable approach to control for the endogeneity of tariffs and sample selection.
- Published
- 2017
37. (NHC)NiH-Catalyzed Intermolecular Regio- and Diastereoselective Cross-Hydroalkenylation of Endocyclic Dienes with α-Olefins
- Author
-
Chun-Yu Ho, Chen Weihao, Lian Xiaoyan, Yuchen Li, and Liang Dang
- Subjects
Diene ,Stereochemistry ,010405 organic chemistry ,Heteroatom ,Substituent ,Cationic polymerization ,General Chemistry ,General Medicine ,010402 general chemistry ,Medicinal chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Yield (chemistry) ,Chirality (chemistry) ,Selectivity - Abstract
Highly selective cross-hydroalkenylation of endocyclic-1,3-dienes at the least substituted site with a-olefins was achieved by set of neutral NHC-Ni(II)H(OTf), and by cationic Ni(II) catalysts with novel NHC structure. Under the heteroatom assistance, skipped dienes were obtained in good yield by using as low as equal molar amount of substrate pairs and 2-5 mol% catalyst. A rare 4,3- product selectivity (i.e., H at C4 and alkenyl group at C3 of diene) was observed, which is different from known dimerizations of a-olefins with both acyclic Co and Fe systems. The substituent effects of NHC, 1,3-diene and a-olefins on chemo-, regio- and diastereo-selectivity were studied. High level of chirality transfer was observed by using chiral cyclohexadiene derivatives.
- Published
- 2017
38. Design, development and clinical validation of computer-aided surgical simulation system for streamlined orthognathic surgical planning
- Author
-
Dennis Chun Yu Ho, Yingying Lai, John F. Teichgraeber, David M. Alfi, Huaming Mai, Daeseung Kim, Jaime Gateno, Jianfu Li, Siting Liu, Zixiang Xiong, James J. Xia, and Peng Yuan
- Subjects
Cephalometry ,medicine.medical_treatment ,Biomedical Engineering ,Orthognathic surgery ,Health Informatics ,Surgical planning ,Article ,User-Computer Interface ,03 medical and health sciences ,Orthognathic Surgical Procedures ,Imaging, Three-Dimensional ,0302 clinical medicine ,medicine ,Humans ,Computer Simulation ,Radiology, Nuclear Medicine and imaging ,Segmentation ,Computer vision ,Orthodontics ,Protocol (science) ,business.industry ,030206 dentistry ,General Medicine ,Image segmentation ,Computer Graphics and Computer-Aided Design ,Computer Science Applications ,Splints ,Surgery, Computer-Assisted ,030220 oncology & carcinogenesis ,Computer-aided ,Computer-Aided Design ,Surgery ,Computer Vision and Pattern Recognition ,Artificial intelligence ,business - Abstract
There are many proven problems associated with traditional surgical planning methods for orthognathic surgery. To address these problems, we developed a computer-aided surgical simulation (CASS) system, the AnatomicAligner, to plan orthognathic surgery following our streamlined clinical protocol. The system includes six modules: image segmentation and three-dimensional (3D) reconstruction, registration and reorientation of models to neutral head posture, 3D cephalometric analysis, virtual osteotomy, surgical simulation, and surgical splint generation. The accuracy of the system was validated in a stepwise fashion: first to evaluate the accuracy of AnatomicAligner using 30 sets of patient data, then to evaluate the fitting of splints generated by AnatomicAligner using 10 sets of patient data. The industrial gold standard system, Mimics, was used as the reference. When comparing the results of segmentation, virtual osteotomy and transformation achieved with AnatomicAligner to the ones achieved with Mimics, the absolute deviation between the two systems was clinically insignificant. The average surface deviation between the two models after 3D model reconstruction in AnatomicAligner and Mimics was 0.3 mm with a standard deviation (SD) of 0.03 mm. All the average surface deviations between the two models after virtual osteotomy and transformations were smaller than 0.01 mm with a SD of 0.01 mm. In addition, the fitting of splints generated by AnatomicAligner was at least as good as the ones generated by Mimics. We successfully developed a CASS system, the AnatomicAligner, for planning orthognathic surgery following the streamlined planning protocol. The system has been proven accurate. AnatomicAligner will soon be available freely to the boarder clinical and research communities.
- Published
- 2017
39. Risk taking after absolute and relative wealth changes: The role of reference point adaptation
- Author
-
Chun-Yu Ho, Xiangdong Qin, and Hong Chao
- Subjects
Social comparison theory ,Economics and Econometrics ,050208 finance ,Relative wealth ,05 social sciences ,Adaptation (eye) ,Absolute (philosophy) ,Accounting ,0502 economics and business ,Economics ,Demographic economics ,sense organs ,050207 economics ,skin and connective tissue diseases ,Risk taking ,Socioeconomics ,Finance - Abstract
We conducted an experiment to compare subjects’ attitudes toward risk before and after they experienced wealth changes induced by a real-effort task. We identified and estimated the subjects’ levels of reference point adaptation to absolute and relative wealth changes. We found that after experiencing a larger loss than others, the subjects did not completely adapt their reference points to the absolute wealth loss and the relative negative wealth gap, and thus significantly increased their risk-taking behavior. However, the subjects also did not adjust their attitudes toward risk after experiencing a smaller loss than others, a smaller gain than others, or a larger gain than others. This may be because they promptly adapted to wealth changes or because they did not adapt to wealth changes but the effects of absolute and relative wealth changes mostly offset each other.
- Published
- 2017
40. The mechanism and regioselectivities of (NHC)nickel(<scp>ii</scp>)hydride-catalyzed cycloisomerization of dienes: a computational study
- Author
-
Yuan Gao, K. N. Houk, Xin Hong, and Chun-Yu Ho
- Subjects
chemistry.chemical_classification ,Steric effects ,Olefin fiber ,Diene ,010405 organic chemistry ,Stereochemistry ,Hydride ,Organic Chemistry ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Medicinal chemistry ,Transition state ,0104 chemical sciences ,Ring strain ,chemistry.chemical_compound ,Cycloisomerization ,chemistry ,Physical and Theoretical Chemistry ,Alkyl - Abstract
Transition metal-catalyzed hydroalkenylation is widely applied in organic synthesis to construct carbon–carbon bonds and synthesize substituted alkenes. In this work, the mechanism and regioselectivities of [(NHC)NiH]+-catalyzed intramolecular cycloisomerization of dienes are studied by density functional theory (DFT) calculations. Through an initial hydride insertion, [(NHC)NiH]+ reacts with the diene substrate to generate the alkyl nickel species. This alkyl nickel species is the resting state of the catalytic cycle, and the hydroalkenylation reaction involves sequential olefin insertion and β-hydride transfer. The selectivity between the possible cycloisomerization products is determined by both the olefin insertion and β-hydride transfer steps. The olefin insertion favors the exo-cyclization due to the high ring strain of the insertion transition states for the endo-cyclization. In the β-hydride transfer step, the hydride transfers to the internal olefin position selectively to avoid the steric repulsions between the bulky NHC ligand and the alkyl substituent of the olefin substrate. This selectivity of β-hydride transfer leads to the n-exo cyclization instead of the (n − 1)-exo cyclization. These mechanistic insights will shed light on the future development of transition metal-catalyzed hydroalkenylation reactions.
- Published
- 2017
41. [(NHC)Ni
- Author
-
Jian-Qiang, Huang and Chun-Yu, Ho
- Abstract
A cross-hydroalkenylation/rearrangement cascade (HARC), using a cyclopropene and alkyne as substrate pairs, was achieved for the first time by using new [(NHC)Ni(allyl)]BAr
- Published
- 2019
42. Competition and countervailing power: Evidence from the China Eastern and Shanghai Airlines merger
- Author
-
Yanhao Wang, Chun-Yu Ho, and Patrick S. McCarthy
- Subjects
050210 logistics & transportation ,020209 energy ,Strategy and Management ,Supply chain ,05 social sciences ,Event study ,Transportation ,02 engineering and technology ,Competitor analysis ,Management, Monitoring, Policy and Law ,Domestic market ,Competition (economics) ,Internationalization ,0502 economics and business ,0202 electrical engineering, electronic engineering, information engineering ,Countervailing power ,Market power ,Business ,Law ,Industrial organization - Abstract
This paper examines the motives and effects behind the horizontal merger between China Eastern and Shanghai Airlines in 2009. We develop testable hypotheses, incorporating into a unified framework the two merging airlines, their domestic and international competitors, and relevant airports along the supply chain. We employ an event study methodology and show that domestic competitors gain whereas international competitors lose. Our results suggest that the sources of gain for the merging firms are market power in domestic markets and efficiency improvement in international markets. Further, as a hub for the merged airline, Shanghai Airport experienced positive abnormal returns. Our results do not support the hypothesis that the merged airline gains countervailing power towards airports. Our event study findings are robust to alternative estimation periods and samples, and are consistent with analyst forecasts and long-run operating performances.
- Published
- 2021
43. Decomposing sources of gain from airline mergers: A model and case study from China
- Author
-
Yanhao Wang, Chun-Yu Ho, and Patrick S. McCarthy
- Subjects
Productive efficiency ,050210 logistics & transportation ,05 social sciences ,Economics, Econometrics and Finance (miscellaneous) ,0211 other engineering and technologies ,Event study ,021107 urban & regional planning ,Transportation ,02 engineering and technology ,Decomposition analysis ,Profit (economics) ,0502 economics and business ,Economics ,Economic analysis ,Market power ,China ,Industrial organization - Abstract
This paper proposes a decomposition of sources of gain of airline mergers. Economic analysis of horizontal mergers often attributes the gains of the merger to market power and productive efficiency effects. We adopt a Williamson framework to propose a decomposition analysis quantifying the relative importance of these two effects for airline mergers. First, we use an event study to compute the market power and productive efficiency wealth effects in airline mergers. Second, we use the airline's operating statistics to compute the proportion of profit gain due to market power and productive efficiency. We then apply those proportions to decompose the sources of wealth effects from the event study. In a case study, we apply this methodology to analyze the horizontal merger between China Eastern and Shanghai Airlines in 2009. Our results find that improved productive efficiency contributed about four-fifths to the merged airline's increased wealth, while increased market power contributed about one-fifth.
- Published
- 2020
44. Risk and return of online channel adoption in the banking industry
- Author
-
Li Xu, Dongwei He, and Chun-Yu Ho
- Subjects
040101 forestry ,Economics and Econometrics ,Solvency ,050208 finance ,Cost efficiency ,business.industry ,05 social sciences ,Risk–return spectrum ,Sample (statistics) ,04 agricultural and veterinary sciences ,Labor intensity ,0502 economics and business ,Econometrics ,0401 agriculture, forestry, and fisheries ,business ,Profit efficiency ,Finance ,Risk management ,Communication channel - Abstract
Online banking has become an important distribution channel for commercial banks. We construct a bank-specific indicator of online channel adoption to study the risk and return of online channel based on a sample of 118 Chinese banks over the period of 2002–2016. Our empirical results find that online channel improves profit efficiency (i.e. a positive return) of the adopting banks. Even though cost efficiency deteriorates, such improvement attributes to the rise in non-interest income efficiency. In reference to risk management, online channel weakens loan quality of the adopting banks, which also raises their solvency risk accordingly. Overall, our results suggest that online channel increases the return of adoption banks albeit at a higher risk. Such risk-return effects are heterogeneous depending on the management skill, labor intensity and size of adopting banks. However, there is no significant return relates to the costly content enrichment of online channel. Finally, our results are robust to alternative specifications, alternative measures of bank efficiency and risk, alternative sample selection and estimation methods, and omitted variable biases.
- Published
- 2020
45. Applications of (NHC)Ni(II) Catalyzed [3+2] Hydroalkenylation-Rearrangement Cascades
- Author
-
Xue-Feng Yong, Chun-Yu Ho, and Jian-Qiang Huang
- Subjects
Chemistry ,Organic Chemistry ,Polymer chemistry ,Catalysis - Published
- 2020
46. Intranasal delivery of a novel acetylcholinesterase inhibitor HLS-3 for treatment of Alzheimer's disease
- Author
-
Chun-Yu Ho, Marvin Mak, Yin Cheong Wong, Yifan Han, Zhong Zuo, Lisi He, Shuai Qian, and Qianwen Wang
- Subjects
0301 basic medicine ,medicine.drug_class ,Cell Survival ,Glucuronidation ,Administration, Oral ,Pharmacology ,030226 pharmacology & pharmacy ,General Biochemistry, Genetics and Molecular Biology ,Epithelium ,Cell Line ,03 medical and health sciences ,0302 clinical medicine ,Pharmacokinetics ,Oral administration ,Alzheimer Disease ,medicine ,Animals ,Humans ,General Pharmacology, Toxicology and Pharmaceutics ,Administration, Intranasal ,business.industry ,General Medicine ,Rats ,030104 developmental biology ,Acetylcholinesterase inhibitor ,Liver ,Tacrine ,Area Under Curve ,Drug Design ,Acetylcholinesterase ,Microsomes, Liver ,Nasal administration ,Cholinesterase Inhibitors ,Caco-2 Cells ,business ,Dimerization ,Drug metabolism ,Ex vivo ,medicine.drug - Abstract
Aim The present study aims to investigate the pharmacokinetics and pharmacodynamics of HLS-3, a tacrine dimer with high anti-acetylcholinesterase activity for the treatment of Alzheimer's disease. Main methods In vitro Calu-3 and Caco-2 cell monolayer transport and liver microsomal incubation studies of HLS-3 were carried out to evaluate its nasal epithelium and intestinal membrane permeability, transporters involved in absorption and hepatic metabolism. In vivo pharmacokinetics of HLS-3 followed by central and peripheral cholinergic mediated responses and ex vivo AChE activities in rats via oral and intranasal administrations were further investigated and compared. Key findings Our in vitro studies suggested that HLS-3 is the substrate of both P-gp and MRPs with no significant hepatic oxidation and glucuronidation metabolism. Oral administration only delivered trace amount of HLS-3 in systemic circulation with a high faecal recovery of 70.7%, whereas intranasal administration demonstrated an absolute bioavailability of 28.9% with urinary and faecal recoveries of 1.5% and 34.0%, respectively. In comparison to oral administration of HLS-3, intranasally delivered HLS-3 exhibited significant higher central cholinergic mediated responses without obvious peripheral side effect. Significance Intranasal delivery of HLS-3 with better pharmacokinetics and pharmacodynamics performances provides a promising approach for treatment of Alzheimer's disease.
- Published
- 2018
47. Computational Exploration of Mechanism and Selectivities of (NHC)Nickel(II)hydride-Catalyzed Hydroalkenylations of Styrene with α-Olefins
- Author
-
Yun-Fang Yang, Xin Hong, Chun-Yu Ho, Kendall N. Houk, Jinglin Wang, and Lisi He
- Subjects
Olefin fiber ,Hydride ,Stereochemistry ,Regioselectivity ,General Chemistry ,Medicinal chemistry ,Catalysis ,Styrene ,chemistry.chemical_compound ,chemistry ,Chemoselectivity ,Carbene ,Isomerization ,Phosphine - Abstract
The [LNiH]+-catalyzed hydroalkenylation between styrene and α-olefins gives distinctive chemo- and regioselectivities with N-heterocyclic carbene (L = NHC) ligands: (a) the reaction with NHC ligands produces the branched tail-to-tail products, whereas the reaction with phosphine ligands (L = PR3) favors the tail-to-head regio-isomers; (b) the reaction stops at heterodimerization with no further oligomerization even with excess α-olefin substrates; (c) typical side reactions with α-olefins, such as isomerization to internal olefins or polymerization, are either significantly diminished or eliminated. To understand the operating mechanism and origins of selectivities, density functional theory (DFT) calculations were performed, and several additional experiments were conducted. The olefin insertion step is found to determine both the regioselectivity and chemoselectivity, leading to the tail-to-tail heterohydroalkenylation product. With a small NHC ligand (1,3-dimethylimidazol-2-ylidene), the intrinsic elec...
- Published
- 2015
48. SWITCHING COST AND DEPOSIT DEMAND IN CHINA
- Author
-
Chun-Yu Ho
- Subjects
Price elasticity of demand ,Counterfactual thinking ,Economics and Econometrics ,Value (economics) ,Economics ,Econometrics ,Position (finance) ,Time horizon ,Product differentiation ,Elasticity (economics) ,Monopoly - Abstract
This article develops and estimates a dynamic model of consumer demand for deposits in which banks provide differentiated products and product characteristics that evolve over time. The switching cost is 0.8% of the deposit's value, which leads the static model to bias the demand estimates. The dynamic model shows that the price elasticity over a long time horizon is larger than the same elasticity over a short time horizon. Counterfactual experiments with a dynamic monopoly show that reducing the switching cost has a comparable competitive effect on bank pricing as a result of reducing the dominant position of the monopoly
- Published
- 2015
49. Substituted 1,3-cyclohexadiene synthesis by NHC–Nickel(0) catalyzed [2+2+2] cycloaddition of 1,n-Enyne
- Author
-
Siu-Chung Chan, Jian-Ping Zhao, and Chun-Yu Ho
- Subjects
chemistry.chemical_classification ,Enyne ,Organic Chemistry ,Alkyne ,chemistry.chemical_element ,Ether ,Biochemistry ,Medicinal chemistry ,Cycloaddition ,Catalysis ,chemistry.chemical_compound ,Nickel ,chemistry ,Furan ,Drug Discovery ,Unsaturated hydrocarbon - Abstract
This paper describes a catalytic and selective synthesis of substituted 1,3-cyclohexadiene fused with xH-pyran and furan. By using terminal enynes as substrates, NHC–Ni(0) as catalyst, and an ether as spacer between the two unsaturated hydrocarbon termini, the system competed with the terminal alkyne cyclotrimerization and yielded the desired [2+2+2] cycloaddition.
- Published
- 2015
50. The real option approach to adoption or discontinuation of a management accounting innovation: the case of activity-based costing
- Author
-
Chun-Yu Ho and Shu Feng
- Subjects
Net profit ,050208 finance ,Actuarial science ,Present value ,05 social sciences ,050201 accounting ,General Business, Management and Accounting ,Option value ,Corporate finance ,Accounting ,Sectoral output ,0502 economics and business ,Management accounting ,Economics ,Call option ,Activity-based costing ,Finance - Abstract
This paper employs the real option approach (ROA) to study the investment decision of a management accounting innovation—the case of activity-based costing (ABC)—adoption or discontinuation under uncertainty. We argue that investing in ABC is analogous to having the option rights in a financial (American) call option. We propose a model taking the firm’s total annual production as primary decision variable and using the added annual net profits after establishing ABC to identify the optimal threshold for adoption or discontinuation. We find that the optimal adoption (resp., discontinuation) threshold is higher (resp., lower) when obtained by the ROA than by the net present value (NPV) method; thus, the ROA is more conservative than the NPV approach. Their difference stems mainly from the ROA’s option value of delay before implementing the adoption/discontinuation decision. Further, recent empirical researches based on survey found inconclusive results about the adoption of ABC. For instance, there are studies found that manufacturing sector having a higher adoption rate of ABC than non-manufacturing sector, but the other studies find the opposite. Our theoretical model explains the inconclusive results from the empirical researches can be driven by the variations in mean and volatility of sectoral output growth, which are omitted in those studies.
- Published
- 2015
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.