• Asian Journal of Innovation and Policy
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• v.6 no.3
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• pp.274-294
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• 2017

While studies have viewed the effect of Chinese talent-attracting programs launched by government since reform and open door policy, little of them has assessed these programs empirically and pertinently. This article intends to assess an important program - the Thousand Youth Talents Program (TYTP). Frist, this paper proposed a transnational migration matrix of the academics to clarify the dynamic mechanism of academic brain gain at the high end. Then, the Kaplan-Meier analysis and Cox regression model are used to empirically analyze the policy effect of TYTP. The results show that, academic ability have double edged impacts on brain gain at the high end, some scholars whose last employer's academic ranking is world's Top100 have stronger willing to return, and the negative effect of academic ranking decreases with time passing; while scholars with a tenure-track position, a tenure position or a permanent position tend to stay overseas, and the hazard rate of staying increases with age. The older scholars have more intentions to go back China, while gender was not a significant factor influencing academic return at the high end. That is, the talent-attracting programs has partly succeeded in bringing back the academics at the high end.

• Toxicological Research
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• v.6 no.2
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• pp.131-142
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• 1990

The selective toxicity of lead was tested in central catecholaminergic nervous system of postnatally lead exposed rats. Three groups of animals were prepared; 1) rats exposed to low dose of lead (0.05%PbAc); 2) rats exposed to high dose of lead(0.2%PbAc); 3) age-matched normal control rats. At2, 4, 6 and 8 weeks of age brain and body weight gain, and lead concentrations in brain tissues were measured. At the same ages tyrosine hydroxylase and Na-K ATPase activities were measured in the 4 brain areas of each animal. Body weight gain was decreased after 6 weeks of age in rats exposed to high dose of lead. Concentrations of lead in whole brain tissues were increased from 0.37 to 0.83 (ng/mg wet tissue) in these animals. in lead exposed rats, tyrosine hydroxylase activities were higher but Na-K ATPase activities were lower than those of age-matched control animals. Brain areas where tyrosine hydroxylase activities were detected without concomitant changes of Na-K ATPase activities were pons-medulla (2 weeks of age) and telencephalon (6 weeks of age) in rats exposed to low dose of lead, and those in rats exposed to high dose of lead were midbrain (4 and 6 weeks of age). These data indicate that catecholaminergic nervous system in the brain areas described above could selectively be affected by lead.

• Nutrition Research and Practice
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• v.1 no.4
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• pp.291-297
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• 2007

This study was conducted to investigate the effect of dietary soluble fiber administration and/or high fat diet on serum and brain neurohormonal profiles, adipose tissue mass and body weight gain in Sprague-Dawley rats. Four groups of rats were respectively fed 10% fat diet (C), 10% fat plus pectin diet (P), 20% fat diet (HFC) and 20% fat plus pectin diet (HFP) for 4 weeks. In HFP group, the food and energy intake, body weight gain, FER including fecal excretion were the smallest (p<0.05). Serum HDL-cholesterol, triglyceride and glucose level were also the lowest in HFP group (p<0.05). The weight of brain, epididymal fat pad and adrenal gland except liver didn't show any significant differences among groups. Interestingly serum norepinephrine concentration of HFP group tended to be higher, but dopamine concentration tended to be lower than those of HFC group. However serum catecholamine concentration didn't show any significant differences among all groups. Norepinephrine and epinephrine contents of right portion of midbrain of P and HFP groups were remarkably lower than those of the C group. These results suggested that soluble fiber pectin consumption might affect neurohormonal profiles in serum and brain according to dietary fat level.

• Journal of Nutrition and Health
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• v.27 no.9
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• pp.901-909
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• 1994

The effects of sardine oil(high in eicosapentaenoic acid : EPA) and tuna oil(high in docosahexaenoic acid : DHA, also high in EPA) on fatty acid composition of brain and learning ability were evaluated in male weanling Sprague-Dawley rats and compared with the effects of corn oil and beef tallow. Animals assigned by randomized block design to one of the four experimental diet groups containing dietary lipid at 15%(w/w) level were given ad libitum for 7 weeks. Food intake and body weight gain of the fish oil groups were significantly lower than those of the corn oil and beef tallow groups. However, brain weights of the groups were not significantly different. In the brain fatty acid composition, the corn oil group showed high concentrations of n-6 fatty acids, the fish oil groups of n-3 fatty acids, and the beef tallow group of saturated fatty acids. Brain EPA and DHA contents of the fish oil groups showed significantly higher than the other groups while the brain ratio of saturated/monounsaturated/polyunsaturated fatty acid was controlled in a narrow range. In a maze test, the fish oil groups appeared to arrive at the goal faster than the corn oil and beef tallow groups. It explained that EPA in diets might efficiently convert to DHA resulting in DHA accumulation in brain tissue and might increase the learning performance as DHA did.

• Journal of Korea Technology Innovation Society
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• v.19 no.2
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• pp.395-415
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• 2016

As international mobility of the high-caliber manpower increases, recruitment of the brain from overseas becomes a critical factor in determining national innovation capacity. This paper reviewed the theories of reverse brain drain, summarized the factors for recruitment of the brain from abroad, and empirically analyzed priority of the factors through the survey on overseas scientists from Vietnam, using conjoint analysis. The results of the analysis shows that high-level salaries, proper research environments, and environment for child education were the important factors. Factors such as scientists respect culture and career development opportunities are not considered important. This paper shows that the exceptionally higher salary should be paid and it also indicates that the policy determination from Vietnam government should be made accordingly.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.4
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• pp.325-332
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• 2016

Resveratrol, a phytoalexin, is reported to activate AMP-activated protein kinase (AMPK) in vascular cells. The blood-brain barrier (BBB), formed by specialized brain endothelial cells that are interconnected by tight junctions, strictly regulates paracellular permeability to maintain an optimal extracellular environment for brain homeostasis. The aim of this study was to elucidate the effects of resveratrol and the role of AMPK in BBB dysfunction induced by lipopolysaccharide (LPS). Exposure of human brain microvascular endothelial cells (HBMECs) to LPS ($1{\mu}g/ml$) for 4 to 24 hours week dramatically increased the permeability of the BBB in parallel with lowered expression levels of occluding and claudin-5, which are essential to maintain tight junctions in HBMECs. In addition, LPS significantly increased the reactive oxygen species (ROS) productions. All effects induced by LPS in HBVMCs were reversed by adenoviral overexpression of superoxide dismutase, inhibition of NAD(P) H oxidase by apocynin or gain-function of AMPK by adenoviral overexpression of constitutively active mutant (AMPK-CA) or by resveratrol. Finally, upregulation of AMPK by either AMPK-CA or resveratrol abolished the levels of LPS-enhanced NAD(P)H oxidase subunits protein expressions. We conclude that AMPK activation by resveratrol improves the integrity of the BBB disrupted by LPS through suppressing the induction of NAD(P)H oxidase-derived ROS in HBMECs.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.6
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• pp.677-685
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• 1998

To investigate the effects of neonatal stress on behavior and neurochemistry, rats were exposed to the footshock stress on postnatal day (PND) 14 or PNDs 14 and 21. Rats were exposed to uncontrollable electric shocks delivered to the floor with a constant current (0.8 mA) for 5 sec period. Daily sessions consisted of 60 trials on a random time schedule with an average of 55 sec. The first exposure to footshocks on PND 14 decreased body weight gain for 1 day. However, the second exposure to footshocks on PND 21 did not affect body weight gain. Exploratory activity was measured by exposing a rat to a novel environment 24 h after experience of footshocks. Similar to the body weight changes, a decreased activity was noted after the first exposure to footshocks, while no changed activity was noted after the second exposure to footshocks. However, the Bmax value of $5-HT_{2A/2C}$ receptors in the cortex decreased by the second exposure to footshocks, but not by the first exposure to footshocks. Moreover, an autoradiographic study revealed that the density of $[^3H]dexamethasone$ binding in hippocampus decreased in rats exposed to footshocks 4 times during PND $14{\sim}20.$ These results suggest that the uncontrollable footshock stress changes 5-hydroxytryptamine and glucocorticoid receptor systems acutely and that the repeated exposure to the same stress may not elicit behavioral alterations by the compensatory activity of young brain although changes in some neurochemistry exist.

• Journal of Nutrition and Health
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• v.28 no.7
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• pp.602-611
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• 1995

This study was designed to find out the effects of $\omega$-3 and $\omega$-6 polyunsaturated and saturated fatty acid from prenatal to growing period on the brain growth and behavioral development of rats. Rats(Sprague-Dawley strain) were fed experimental diets-fish oil, corn oil or beef tallow-with different contents of $\omega$-3 and $\omega$-6 fatty acids throughout the prenatal and lactational period and up to 10 weeks of age. DNA and RNA concentration of rat brain were determined at 0, 3, 6 weeks of age and choline and acetylcholine concentrations were analyzed at 10 weeks of age. When the rats were 7 weeks of age, position reversional test in a Y-shaped water maze for 4 weeks was measured. The experimental results obtained are summarized as follows. Food intakes were significantly lower in fish oil group and body weight gain was low in the group fed beef tallow and the groups fed fish oil and corn oil were somewhat good. Food efficiency ratio was not significantly different among the groups. Brain weight was not affected by the fatty acid composition of experimental diets and DNA and RNA concentration of the rat brain were consistently maintained at the same level. It was not different significantly among the dietary groups in the DNA and RNA concentrations of the rat brain during the experimental period. The acetylcholine concentration in the fish oil group was somewhat higher than the other groups. The position reversional test in a Y-shaped water maze showed a significant difference the score of test among the experimental groups. The score of the rats fed the fish oil diet was significantly higher than the other groups and the concentration of acetylcholine in brain were too. Therefore the correlatin between the Y-shaped water maze test score and the acetylcholine concentratin in the brain was found. Above finding support the content that dietary fatty acid composition does not affect to the brain cell number and cell size but the behavior development is influenced. Therefore, the improvement of behavior development is required the effective usage of finny tribe.

• Journal of Korea Technology Innovation Society
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• v.17 no.1
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• pp.264-288
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• 2014

The competition for attracting outstanding HRST (human resource for science and technology) who can lead technological innovation is heating up all over the world. The various concepts, which are brain drain, brain gain, brain overflow, brain migration, brain circulation, are used to explain the international mobility of HRST. But the concept of brain scout is the more adequate for explaining in the case of outstanding HRST as the main cause of excessive competition for scouting. This study analyzed the critical factors of the determinants of Korean students in the USA who have intentions of returning to Korea in view of brain scout. As the first step in this study, potential factors and hypothesis are established by the interviews. As the second step, the major factors are examined by surveys and hypothesis testing. Also, a new model for decision-making is proposed which describes intentions of returning to Korea by logistic regression analysis and contributions of each factor derived from this study were compared. Finally, policy implications for attracting outstanding HRST and the limit of this study are discussed.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.873-879
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• 2011

5-Fluorouracil (5-FU), an anticancer agent was covalently attached to the recently developed sorbitol-based G8 transporter, and the conjugate (7) with FITC was found to have an affinity toward mitochondria and to readily cross BBB to gain an entry into mouse brain. Measured by $IC_{50}$, the conjugate (9) without the fluorophore showed enhanced cytotoxic activity toward two types of multidrug-resistant cell lines. These results strongly suggest that the sorbitol-based G8 transporter can be utilized as a good CNS delivery vector.