An Anatomy of the Magnet Effect: Evidence from the Korea Stock Exchange High-Frequency Data

We examine the existence and the forms of the magnet effect using transaction files and limit order book of the Korea Stock Exchange. A significant magnet effect exists in all five market microstructure variables (the rate of return, trading volume, volatility, order flow, and order type) when the limit hit becomes imminent. Specifically, investors place increasingly more orders, choose proportionally more market orders, and frequently reposition existing orders to advance transactions. We also find that: (i) a narrower price limit exhibits higher acceleration rates in all five variables compared to a wider price limit; and (ii) the upper limit hits draw heavier volumes of transactions, order submissions and market orders than the lower limit hits. We confirm that the magnet effect is a phenomenon unique only to markets with daily price limit systems.Price Limit, Magnet Effect, Rate of Return, Trading Volume, Volatility, Order Flow, Order Type, Price Trajectory, Korea Stock Exchange

A study on inclusion formation mechanism in alpha-LiIO sub 3 crystals

The spatial distribution of inclusions in alpha-LiIO3 crystals by means of an argon laser beam scanning technique is studied. The effects of crystal dimensions and solution fluid flow on the inclusion formation in the alpha-LiIO3 crystals were observed. It was further shown that the fluid flow plays an important role in the formation of inclusions. The results obtained were further applied and verified by growing a perfect alpha-LiIO3 single crystal. An experimental foundation for further theoretical studies on the causes of inclusions may be provided

Investigation of Factors Affecting Microdialysis Probe Delivery and Recovery of Puerarin In Vitro

Purpose: To investigate in vitro the factors affecting microdialysis probe delivery and recovery of puerarin .Methods: The recovery and delivery of puerarin were tested for extraction efficiency and retro-dialysis methods. Factors such as drug concentration, stirring speed, additives and length of membrane were studied to determine differences between recovery and delivery.Results: It was observed that the delivery of the targeting analyte was different from its recovery. Both delivery and recovery of puerarin were independent of the concentration of the drug. Probe delivery increased from 62.18 to 67.98 % (p < 0.01), recovery from 59.19 to 78.44 % (p < 0.01), and stirring speed increased from 0 to 800 rpm. The difference between them directly correlated with stirring speed in the range 2.99 to 10.46 %. Besides, additives, length of membrane also had a strong influence on delivery and recovery. Probe delivery in saline containing 10 % each of ethanol and propylene glycol declined from 62.18 to 42.12 % (p < 0.01), while recovery increased insignificantlly (p < 0.01). Both delivery and recovery declined while the length of membrane was cut down.Conclusion: The in vitro experiments indicate that it was not correct to equate delivery with recovery of puerarin in in vivo microdialysis experiments.Keywords: Microdialysis, Puerarin, Recovery, Probe delivery

Investigation of Factors Affecting Microdialysis Probe Delivery and Recovery of Puerarin In Vitro

Purpose: To investigate in vitro the factors affecting microdialysis probe delivery and recovery of puerarin.Methods: The recovery and delivery of puerarin were tested for extraction efficiency and retro-dialysis methods. Factors such as drug concentration, stirring speed, additives and length of membrane were studied to determine differences between recovery and delivery.Results: It was observed that the delivery of the targeting analyte was different from its recovery. Both delivery and recovery of puerarin were independent of the concentration of the drug. Probe delivery increased from 62.18 to 67.98 % (p < 0.01), recovery from 59.19 to 78.44 % (p < 0.01), as stirring speed was increased from 0 to 800 rpm. The difference between them directly correlated with stirring speed in the range 2.99 to 10.46 %. Besides additives, length of membrane also had a strong influence on delivery and recovery. Probe delivery in saline containing 10 % each of ethanol and propylene glycol declined from 62.18 to 42.12 % (p < 0.01), while recovery increased slightly but insignificantly (p < 0.01). Both delivery and recovery declined when the length of membrane was reduced.Conclusion: The in vitro experiments indicate that it would be incorrect to equate delivery with recovery of puerarin in in vivo microdialysis experiments.Keywords: Microdialysis, Puerarin, Recovery, Probe delivery

Critical role of PPARγ in myeloid-derived suppressor cell-stimulated cancer cell proliferation and metastasis

Lysosomal acid lipase (LAL) is a key enzyme controlling neutral lipid metabolic signaling in myeloid-derived suppressor cells (MDSCs). MDSCs from LAL-deficient (lal-/-) mice directly stimulate cancer cell proliferation. PPARγ ligand treatment inhibited lal-/- MDSCs stimulation of tumor cell growth and metastasis in vivo, and tumor cell proliferation and migration in vitro. In addition, PPARγ ligand treatment impaired lal-/- MDSCs transendothelial migration, and differentiation from lineage-negative cells. The corrective effects of PPARγ ligand on lal-/- MDSCs functions were mediated by regulating the mammalian target of rapamycin (mTOR) pathway, and subsequently blocking MDSCs ROS overproduction. Furthermore, in the myeloid-specific dominant-negative PPARγ (dnPPARγ) overexpression bitransgenic mouse model, tumor growth and metastasis were enhanced, and MDSCs from these mice stimulated tumor cell proliferation and migration. MDSCs with dnPPARγ overexpression showed increased transendothelial migration, overactivation of the mTOR pathway, and ROS overproduction. These results indicate that PPARγ plays a critical role in neutral lipid metabolic signaling controlled by LAL, which provides a mechanistic basis for clinically targeting MDSCs to reduce the risk of cancer proliferation, growth and metastasis