Hexadecanoic Acid from Buzhong Yiqi Decoction Induced Proliferation of Bone Marrow Mesenchymal Stem Cells

Dong-Feng Chen,Xican Li,Zhiwei Xu,Xiaobing Liu,Shao-Hui Du,Hui Li,Jian-Hong Zhou,He-Ping Zeng,Zi-Chun Hua 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.4

Buzhong Yiqi decoction (BYD) is a well-known ancient tonic prescription in traditional Chinese medicine (TCM). The purpose of this study is to identify active components of BYD involved in promoting proliferation of mesenchymal stem cells (MSCs) and to investigate its mechanism. BYD was extracted with petroleum ether, ethanol, and water. Evidence provided by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, bromodeoxyuridine, proliferation cell nuclear antigen immunoreactivity, cell cycle analysis, and gas chromatography-mass spectrometry indicated that hexadecanoic acid (HA) in BYD extracted with petroleum ether is the active compound responsible for increasing proliferation of MSCs. Western blot analysis show that HA significantly increase retinoic acid receptor (RAR) levels of MSCs, but not estrogen receptor, thyroid hormone receptor, vitamin D receptor, glucocorticoid receptor, and peroxisome proliferator-activated receptor. Reverse transcription-polymerase chain reaction revealed that HA significantly increased RAR mRNA levels. Furthermore, the mechanism of HA action depends on RAR pathway and up-regulates expression of mRNA for insulin-like growth factor-I, the target gene of RAR. Our findings have now allowed for a refinement in our understanding of TCM with respect to pharmacological regulation of stem cells and may be useful to stem cell biology and therapy.

COMPETING OR ALIGNING? MOBILE OPERATOR’S PRICING ADAPATATION TO THE CHALLENGES FROM OTT

Rong Chen,Xiaobing Xu,Feng He 글로벌지식마케팅경영학회 2014 Global Marketing Conference Vol.2014 No.10

In this paper, OTT (Over-The-Top) refers to voice, video and data services that arrive from a third party service provider (SP) and doesn’t require any business or technology affiliations with the network operator (Southwell 2011). Traditional telephone companies (telcos) are under big threat from OTT messaging applications which have been splitting flow of text message and voice from the former. Even though, mobile operators still enjoy some asymmetric advantages by controlling the basic telecommunications infrastructure, monitoring the network usage and distinguishing between different OTT actors (Bertin et al. 2011). From a market structure perspective, mobile telecoms industry with the entrance of OTT messaging applications is analogous to the traditional dual-channel structure. On one hand, mobile operators “sell” communication services such as SMS and voice directly to subscribers; on the other hand, they “wholesale” the network infrastructure to OTT SPs on which OTT applications distribute text, picture, video and voice for end users. Extant research has extensively examined the channel selection, channel competition and coordination in traditional sectors (Cai 2010; Cattani et al. 2006; Chiang et al. 2003; Dumrongsir et al. 2008). However, the explanation of dual channel might not be well applicable to the mobile operator and OTT issue considering some new features in the industry. 1) comparing with traditional product distribution, the mobile operators are selling “the right to use the network”, thus they could both charge the “access” and “usage” fee. 2) unlike the traditional retailing channel where consumers make payments to retailer, consumers using OTT would pay network usage fee (data fee) to the mobile operator. 3) traditional retailors earn their profits by selling products with a higher price than the wholesale price. However, OTT services aim to develop their own business after accumulation of sufficient quantities of users, such as revenues form ads, traffic guidance and so on. This paper is conducted to analyze the pricing strategy of mobile operators facing the challenge of OTT. For simplicity, we assume a monopoly market, namely one mobile operator provide network infrastructure for one OTT messaging service provider who provides communication service for consumers. Based on dynamic game theory, we show that: firstly, under non-cooperative strategy, a mobile operator should charge OTT a positive network access fee which is positively correlated to OTT platform’s future commercial value and direct communication service price, and negatively correlated to indirect communication service; secondly, under cooperative strategy, a mobile operator and OTT could create a more joint profit than that under non-cooperative strategy. The platform access fee that the joint venture charges end users is negatively correlated with OTT platform future commercial value; thirdly, despite the choice of cooperative or non-cooperative strategy, the price of direct communication products has a negative correlation with OTT platform future commercial value and a positive correlation with the platform quality; while the price of indirect communication products is positively correlated with platform future commercial value and is negatively correlated with OTT platform quality. Finally, we conclude with a discussion of the managerial implications for mobile operators and OTT SPs. With regard to policy makers, we suggest that a convenient cooperation environment should be provided, because both mobile operator and OTT SP would obtain a high profit under cooperative condition than that under non-cooperative condition and at the same time consumers could also enjoy a better welfare. This study was supported by the National Natural Science Foundation of China (71172011 and 71272160) and NCET-12-0772.

COMPETING OR ALIGNING? MOBILE OPERATOR’S PRICING ADAPATATION TO THE CHALLENGES FROM OTT

Rong Chen,Xiaobing Xu,Feng He 글로벌지식마케팅경영학회 2014 Global Marketing Conference Vol.2014 No.7

In this paper, OTT (Over-The-Top) refers to voice, video and data services that arrive from a third party service provider (SP) and doesn’t require any business or technology affiliations with the network operator (Southwell 2011). Traditional telephone companies (telcos) are under big threat from OTT messaging applications which have been splitting flow of text message and voice from the former. Even though, mobile operators still enjoy some asymmetric advantages by controlling the basic telecommunications infrastructure, monitoring the network usage and distinguishing between different OTT actors (Bertin et al. 2011). From a market structure perspective, mobile telecoms industry with the entrance of OTT messaging applications is analogous to the traditional dual-channel structure. On one hand, mobile operators “sell” communication services such as SMS and voice directly to subscribers; on the other hand, they “wholesale” the network infrastructure to OTT SPs on which OTT applications distribute text, picture, video and voice for end users. Extant research has extensively examined the channel selection, channel competition and coordination in traditional sectors (Cai 2010; Cattani et al. 2006; Chiang et al. 2003; Dumrongsir et al. 2008). However, the explanation of dual channel might not be well applicable to the mobile operator and OTT issue considering some new features in the industry. 1) comparing with traditional product distribution, the mobile operators are selling “the right to use the network”, thus they could both charge the “access” and “usage” fee. 2) unlike the traditional retailing channel where consumers make payments to retailer, consumers using OTT would pay network usage fee (data fee) to the mobile operator. 3) traditional retailors earn their profits by selling products with a higher price than the wholesale price. However, OTT services aim to develop their own business after accumulation of sufficient quantities of users, such as revenues form ads, traffic guidance and so on. This paper is conducted to analyze the pricing strategy of mobile operators facing the challenge of OTT. For simplicity, we assume a monopoly market, namely one mobile operator provide network infrastructure for one OTT messaging service provider who provides communication service for consumers. Based on dynamic game theory, we show that: firstly, under non-cooperative strategy, a mobile operator should charge OTT a positive network access fee which is positively correlated to OTT platform’s future commercial value and direct communication service price, and negatively correlated to indirect communication service; secondly, under cooperative strategy, a mobile operator and OTT could create a more joint profit than that under non-cooperative strategy. The platform access fee that the joint venture charges end users is negatively correlated with OTT platform future commercial value; thirdly, despite the choice of cooperative or non-cooperative strategy, the price of direct communication products has a negative correlation with OTT platform future commercial value and a positive correlation with the platform quality; while the price of indirect communication products is positively correlated with platform future commercial value and is negatively correlated with OTT platform quality. Finally, we conclude with a discussion of the managerial implications for mobile operators and OTT SPs. With regard to policy makers, we suggest that a convenient cooperation environment should be provided, because both mobile operator and OTT SP would obtain a high profit under cooperative condition than that under non-cooperative condition and at the same time consumers could also enjoy a better welfare. This study was supported by the National Natural Science Foundation of China (71172011 and 71272160) and NCET-12-0772.

Dynamic processes of hyporheic exchange and temperature distribution in the riparian zone in response to dam-induced water fluctuations

Dongsheng Liu,Jian Zhao,Xiaobing Chen,Yingyu Li,Shipan Weiyan,Mengmeng Feng 한국지질과학협의회 2018 Geosciences Journal Vol.22 No.3

We examined the dynamic processes of hyporheic exchange and temperature distribution in a riparian zone in response to low-temperature water fluctuations downstream of the Xin’an River Dam, China, using analytical and mainly hydrodynamic methods. For this purpose, we installed six HM21 piezometers (R, P1–P5) between the river water and the groundwater at an interval of approximately 2 m perpendicular to the flow path. We also installed 20 PT100 thermistors (T1–T20) along the transect at depths of 1.19 m to 3.58 m and monitored the temperatures of river and air. Water levels and temperatures were automatically logged every 5 min by the real-time system from November to December 2014 and sent to the remote platform through the remote terminal unit. Results revealed that the intensity and direction of the hyporheic exchange (Q) between the river water and the groundwater varied periodically (t = 1 d) with the water level of the river. In each cycle, the Q was in a counterclockwise loop curve with the water level of the river and with the non-uniform distribution along the transect perpendicular to the river, which showed that the farther the lateral exchange was away from the river, the lower its intensity and the more hysteretic the alteration of its direction. The daily exchange width and residence time had no necessary connection with the average river stage, but mainly depended on the amplitude of the fluctuating river stage and the duration of river infiltration and established a strong linear relationship with their product. The temperature distribution of the riparian aquifer was mainly affected by the surface radiation and river water infiltration. It was characterized as “cool on the surface and warm at the bottom” in the vertical direction and could be divided into low-, medium-, and high-temperature zones along the horizontal direction. The horizontal infiltration distance (L) increased by power functions with the increase in infiltration rate (v) and decrease in river temperature (T).

A Dynamic Linearization Modeling of Thermally Induced Error Based on Data-Driven Control for CNC Machine Tools

Puling Liu,Xiao-dong Yao,Guang-yan Ge,Zhengchun Du,Xiaobing Feng,Jianguo Yang 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.2

This paper proposes a novel dynamic linearization modeling method for machine tool thermal errors based on data-driven control theory, with improved accuracy and robustness under various practical working conditions of machine tool. The nonlinear, quasi-static and pseudo-hysteric characteristics of the machine tool temperature field are identified as the main causes for poor robustness in conventional thermal error mathematical models. The theoretical and practical difficulties in applying conventional modeling approaches based on the model-based control theory are demonstrated using two types of CNC machine tools as examples. The data-driven control theory is applied to dynamic linearization modeling and the developed data model has shown significant improvement over the general dynamic model in terms of model accuracy and robustness. The feasibility and effectiveness of the proposed dynamic linearization modeling method has been verified using two experiments, demonstrating excellent robustness and ability to adapt to various machining conditions and to improve machining accuracy.