Examining Stock Volatility in the Segmented Chinese Stock Markets: A SWARCH Approach

ZHUO QIAO,WEIWEI QIAO,Wing-Keung Wong 연세대학교 동서문제연구원 2010 Global economic review Vol.39 No.3

This study adopts the SWARCH model to examine the volatile behavior and volatility linkages among the four major segmented Chinese stock indices.We find strong evidence of a regime shift in the volatility of the four markets, and the SWARCH model appears to outperform standard generalized autoregressive conditional heteroskedasticity (GARCH) family models. The evidence suggests that, compared with the A-share markets, B-share markets stay in a high-volatility state longer and are more volatile and shift more frequently between high- and low-volatility states. In addition, the relative magnitude of the high-volatility compared with that of the low-volatility state in the B-share markets is much greater than the case in the two A-share markets. B-share markets are found to be more sensitive to international shocks, while A-share markets seem immune to international spillovers of volatility. Finally, analyses of the volatility spillover effect among the four stock markets indicate that the A-share markets play a dominant role in volatility in Chinese stock markets.

Knockdown of the M2 Isoform of Pyruvate Kinase (PKM2) with shRNA Enhances the Effect of Docetaxel in Human NSCLC Cell Lines In Vitro

Tiankui Qiao,Tiankui Qiao,Xibing Zhuang,Wei Chen,Na Xing,Qi Zhang 연세대학교의과대학 2016 Yonsei medical journal Vol.57 No.6

Purpose: The aim of our study was to explore the relationships between the M2 isoform of pyruvate kinase (PKM2) and the sensitivityof human non-small cell lung cancer (NSCLC) cells to docetaxel in vitro. Materials and Methods: With the method of plasmid transfection, we silenced the expression of PKM2 successfully in A549 and H460 cells. Western blotting and real-time PCR were applied to detect PKM2 expression at protein and gene levels. Cell viability was examined by CCK8 assay. Cell cycle distribution and apoptosis were examined by flow cytometry. P21 and Bax were detected. Results: Expression of PKM2 mRNA and protein were significantly decreased by shRNA targeting PKM2. Silencing of PKM2 increaseddocetaxel sensitivity of human NSCLC A549 and H460 cells in a collaborative manner, resulting in strong suppression of cell viability. The results of flow cytometric assays suggested that knockdown of PKM2 or docetaxel treatment, whether used singlyor in combination, blocked the cells in the G2/M phase, which is in consistent with the effect of the two on the expression of p21. Cells with PKM2 silencing were more likely to be induced into apoptosis by docetaxel although knockdown of PKM2 alone can’t induce apoptosis significantly, which is in consistent with the effect of the two on Bax expression. Conclusion: The results suggest that PKM2 knockdown could serve as a chemosensitizer to docetaxel in non-small lung cancer cells through targeting PKM2, leading to inhibition of cell viability, increase of cell arrest of G2/M phase and apoptosis.

D-RADA16-RGD-Reinforced Nano-Hydroxyapatite/Polyamide 66 Ternary Biomaterial for Bone Formation

Bo Qiao,Bin He,Ao Zhou,Yuling Li,Xiaojun Chen,Qiming Yang,Beike Chen,Bo Qiao,Dianming Jiang 한국조직공학과 재생의학회 2019 조직공학과 재생의학 Vol.16 No.2

BACKGROUND: Nano-hydroxyapatite/polyamide 66 (nHA/PA66) is a composite used widely in the repair of bone defects. However, this material is insufficient bioactivity. In contrast, D-RADA16-RGD self-assembling peptide (DRADA16- RGD sequence containing all D-amino acids is Ac-RADARADARADARADARGDS-CONH2) shows admirable bioactivity for both cell culture and bone regeneration. Here, we describe the fabrication of a favorable biomaterial material (nHA/PA66/D-RADA16-RGD). METHODS: Proteinase K and circular dichroism spectroscopy were employed to test the stability and secondary structural properties of peptide D-RADA16-RGD respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the surface of these materials. Confocal laser scanning (CLS), cell counting kit-8 tests (CCK-8), alizarin red S staining, cell immunofluorescence analysis and Western blotting were involved in vitro. Also biosafety and bioactivity of them have been evaluated in vivo. RESULTS: Proteinase K and circular dichroism spectroscopy demonstrated that D-RADA16-RGD in nHA/PA66 was able to form stable-sheet secondary structure. SEM and TEM showed that the D-RADA16-RGD material was 7–33 nm in width and 130–600 nm in length, and the interwoven pore size ranged from 40 to 200 nm. CLS suggests that cells in nHA/PA66/ D-RADA16-RGD group were linked to adjacent cells with more actin filaments. CCK-8 analysis showed that nHA/PA66/ D-RADA16-RGD revealed good biocompatibility. The results of Alizarin-red S staining and Western blotting as well as vivo osteogenesis suggest nHA/PA66/D-RADA16-RGD exhibits better bioactivity. CONCLUSION: This study demonstrates that our nHA/PA66/D-RADA16-RGD composite exhibits reasonable mechanical properties, biocompatibility and bioactivity with promotion of bone formation.

Examining the Day-of-the-Week Effects in Chinese Stock Markets: New Evidence from a Stochastic Dominance Approach

ZHUO QIAO,WEIWEI QIAO,Wing-Keung Wong 연세대학교 동서문제연구원 2011 Global economic review Vol.40 No.3

Many researchers have investigated the existence of day-of-the-week effects in different financial markets. However, they have usually adopted a parametric approach, which is known to have a few limitations. This paper adopts a non-parametric stochastic dominance (SD) approach to examine the day-of-the-week effects in Chinese stock markets. In contrast to the extensive evidence of day-of-the-week effects disclosed by a parametric mean-variance (MV) approach, our SD tests show that the day-of-the-week effect is much weaker. We find that there are only Wednesday effects in Chinese A-share and B-share stock markets.

Ceratovacuna atrovirensa Qiao, a new species from China (Aphididae: Hormaphdinae)

Jiang Li-Yun,Chen Jing,Xu Ying,Qiao Ge-xia 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.3

Ceratovacuna atrovirensa Qiao sp.n., a woolly aphid on Indocalamus tessellatus from China, is described and illustrated. The new species is supported by both morphological and molecular data. An updated key to apterous viviparous females of Ceratovacuna is provided. The type specimens are deposited in the National Zoological Museum of China, Institute of Zoology, the Chinese Academy of Sciences, Beijing, China and the Natural History Museum, London, United Kingdom.

Long Non-coding RNA GAS5 Functions as a Tumor Suppressor in Renal Cell Carcinoma

Qiao, Hui-Ping,Gao, Wei-Shi,Huo, Jian-Xin,Yang, Zhan-Shan Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Background: Renal cell carcinoma (RCC) is a malignancy with a poor prognosis. We aimed to explore whether the expression of Long Non-Coding RNA (LncRNA) growth arrest-specific transcript 5 (GAS5) is associated with RCC genesis. Methods: We selected twelve clinical samples diagnosed for renal clear cell carcinoma and found that the LncRNA GAS5 transcript levels were significantly reduced relative to those in adjacent unaffected normal renal tissues. Results: In addition, expression of GAS5 was lower in the RCC cell line A498 than that in normal renal cell line HK-2. Furthermore, using functional expression cloning, we found that overexpression of GAS5 in A498 cells inhibited cell proliferation, induced cell apoptosis and arrested cell cycling. At the same time, the migration and invasion potential of A498 cells were inhibited compared to control groups. Conclusion: Our study provided the first evidence that a decrease in GAS5 expression is associated with RCC genesis and progression and overexpression of GAS5 can act as a tumor suppressor for RCC, providing a potential attractive therapeutic approach for this malignancy.

Expression of c-Type Lysozyme from the Fleshy Shrimp Fenneropenaeus chinensis Is Upregulated Following Vibrio anguillarum and Lipopolysaccharide Injection

Qiao, Guo,Kim, Su-Kyoung,Cho, Yeong-Rok,Kim, Sukyoung,Jang, In-Kwon The Korean Society of Fisheries and Aquatic Scienc 2013 Fisheries and Aquatic Sciences Vol.16 No.4

Chicken-type lysozyme (c-lysozyme) is present in shrimp and is active against some bacteria. To further understand the regulation of c-lysozyme in the fleshy shrimp Fenneropenaeus chinensis, we determined the tissue-specific gene expression of c-lysozyme and the time-course of mRNA expression in response to Vibrio anguillarum and lipopolysaccharide (LPS) injection by quantitative reverse real-time polymerase chain reaction. The results showed that c-lysozyme was expressed in all tissues tested, including gill, eyestalk, eye, hemocytes, hepatopancreas, intestine, heart, and pleopod. It was most highly expressed in the intestine followed by the eyestalk, gill, hemocytes and hepatopancreas. The mRNA expression level began to decline in a short time after V. anguillarum challenge and was then upregulated by two fold or more at 24 h post injection (hpi) compared to that at 0 h. Expression was suppressed shortly after LPS injection and began to increase with higher levels of 5.8-, 5.2- and 8.4-fold at 24, 48, and 72 hpi, respectively. Higher expression was sustained and showed a gradual increasing trend until the end of the experiment (72 hpi). These results increase our understanding of the regulation of defense mechanisms and facilitate an evaluation of the effects of probiotics or immunostimulants in shrimp culture.

Space-Time Pattern of Ion Flow Under AC/DC Hybrid Overhead Lines and Its Application

Qiao, Ji,Zou, Jun,Zhang, Jiangong,Lu, Yao,Lee, Jaebok,Ju, Mun-No IEEE 2018 IEEE transactions on power delivery Vol.33 No.5

<P>Building HVdc and HVac transmission lines in the same corridor or even on the same tower is an attractive way to extend electricity transport capacity where getting the new right of way is difficult. The resulting hybrid lines produce a new corona performance, such as ground-level hybrid electric field and ion current density, which are quite different from those of pure ac or dc lines. In this paper, inherent space-time pattern and characteristics of the information propagation in Lagrangian description are presented for the ion transport problem, that is, the ion density at a certain point has a direct relationship with its drift time. Based on this, the theoretical explanation is provided for the decoupling algorithm, by which the ground-level dc component can be solved with the ac conductors assumed to be at zero potential and vice versa. The simulation results show that the sinusoidal ac field has negligible influence on the dc ion drift time from conductor surface to ground, whereas stationary electric field generated by the grounded ac lines has a dominant effect. Therefore, ac energization has a rather low impact on ground-level quantities and the simplification of grounded ac conductors is quite reasonable.</P>

Preparation of 2D/2D g-C3N4/Ti3C2 MXene composites by calcination synthesis method for visible light photocatalytic degradation of tetracycline

Qiao Le-Le,Zhang Feng-Jun,Kai Chun-Mei,Liu Chao,Wang Ying-Rui,Oh Won-Chun 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.5

In this work, an ultrathin 2D/2D g-C3N4/Ti3C2 heterojunction was synthesized by direct calcination of a mixture of urea and multilayer Ti3C2 for photocatalytic degradation of tetracycline. Among them, urea is the precursor for the generation of g-C3N4 and generates gas to peel the multilayer Ti3C2 into fewer layers while reacting, solving the problem of low yield for the preparation of fewer layers of Ti3C2. The experimental results of tetracycline degradation under visible light showed that pure g-C3N4 (UCN) exhibited weak photoactivity; however, its photocatalytic performance was enhanced when Ti3C2 was coupled with g-C3N4. The best sample (5TC) could degrade 90.1% of tetracycline within 30 min. After four cycles of stability test, the photocatalytic performance did not change significantly, indicating that the prepared 2D/2D g-C3N4/Ti3C2 heterojunction possesses strong photocatalytic performance along with good stability.

Modeling of {10-12}-{10-12} secondary twinning in pre-compressed Mg alloy AZ31

Qiao, H.,Guo, X.Q.,Hong, S.G.,Wu, P.D. Elsevier 2017 Journal of alloys and compounds Vol.725 No.-

<P><B>Abstract</B></P> <P>The deformation characteristics of rolled Mg alloy AZ31, which was previously compressed along the rolling direction and then re-compressed along the transverse direction, have been numerically investigated. Secondary/double twinning is allowed in the current EVPSC-TDT model, and {10-12}-{10-12} secondary twinning is found to play an important role in reproducing the experimental data. The deformation behavior of the pre-compressed materials associated with primary and secondary twining has been interpreted in terms of the predicted activities, twin volume fractions and texture evolutions. The {10-12}-{10-12} secondary twinning in the previously twinned region is most active for the 9% pre-compressed material while primary twinning within the residual un-twinned domain dominates twinning behavior for the 3% pre-compressed material.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The EVPSC model is first extended to simulate the {10-12}-{10-12} twinning. </LI> <LI> The deformation behavior of the pre-compressed materials has been interpreted. </LI> <LI> {10-12}-{10-12} twinning plays a key role in reproducing the experimental data. </LI> </UL> </P>