2,713 research outputs found
the case of the youth thousand talents plan in China
Thesis(Master) -- KDI School: Master of Development Policy, 2022This study examines the impact of the Youth Thousand Talents Plan (YTTP), a Chinese policy to combat brain drain, on the research performance of the award recipients. China has suffered from a lack of high-skilled talent since the Open Door Policy in the 1970s and has thus implemented the YTTP to alleviate this trend by attracting young high-skilled workers in the STEM fields. To estimate the program’s impact, I collected novel data on 1,116 YTTP awardees, covering five waves (2011–2013), and matched them with their publication metrics on Google Scholar. I then analyze the dataset employing a difference-in-differences strategy. The findings show that accepting the YTTP and returning to China decreased the number of publications authored by the awardees by 13.5%. However, there are also some notable heterogenous effects: the results also suggest that the YTTP increased the research performance of female awardees and the number of publications in materials engineering. These findings have three important policy implications. First, the Chinese government should implement countermeasures to support its reverse brain drain policy. Second, the government should consider increasing the number of female high-skilled workers selected for the program. Third, prioritizing certain fields, such as materials engineering, may be useful.I. INTRODUCTION
II. BACKGROUND
III. LITERATURE REVIEW
IV. DATA
V. EMPIRICAL STRATEGY
VI. RESULTS
VII. CONCLUSIONmasterpublishedJi Young HWAN
Principal factors that determine the extension of detection range in molecular beacon aptamer/conjugated polyelectrolyte bioassays.
A strategy to extend the detection range of weakly-binding targets is reported that takes advantage of fluorescence resonance energy transfer (FRET)-based bioassays based on molecular beacon aptamers (MBAs) and cationic conjugated polyelectrolytes (CPEs). In comparison to other aptamer-target pairs, the aptamer-based adenosine triphosphate (ATP) detection assays are limited by the relatively weak binding between the two partners. In response, a series of MBAs were designed that have different stem stabilities while keeping the constant ATP-specific aptamer sequence in the loop part. The MBAs are labeled with a fluorophore and a quencher at both termini. In the absence of ATP, the hairpin MBAs can be opened by CPEs via a combination of electrostatic and hydrophobic interactions, showing a FRET-sensitized fluorophore signal. In the presence of ATP, the aptamer forms a G-quadruplex and the FRET signal decreases due to tighter contact between the fluorophore and quencher in the ATP/MBA/CPE triplex structure. The FRET-sensitized signal is inversely proportional to [ATP]. The extension of the detection range is determined by the competition between opening of the ATP/MBA G-quadruplex by CPEs and the composite influence by ATP/aptamer binding and the stem interactions. With increasing stem stability, the weak binding of ATP and its aptamer is successfully compensated to show the resistance to disruption by CPEs, resulting in a substantially broadened detection range (from millimolar up to nanomolar concentrations) and a remarkably improved limit of detection. From a general perspective, this strategy has the potential to be extended to other chemical- and biological-assays with low target binding affinity
Dual-ion charge-discharge behaviors of Na-NiNc and NiNc-NiNc batteries
Dual-ion sodium-organic secondary batteries were produced with anti-aromatic porphyrinoid, NiNc, as an active electrode material, which exhibited inherent charge-discharge behavior with high discharge capacity, high stability, and high Coulombic efficiency at high current density (132.6 mA h g⁻¹ discharge capacity and 99.4% efficiency at the 100th cycle with 1 A g⁻¹ of current density and 95.3 mA h g⁻¹ discharge capacity and 99.3% efficiency at the 100th cycle with 2 A g⁻¹ of current density)
Anti-inflammatory effect of neo-lignan isoamericanin A via suppression of NF-κB in liposaccharide-stimulated RAW 264.7 cells
Purpose: To investigate the potential anti-inflammatory effects of the seeds of Opuntina humifusa and its active constituents.Methods: The extract of O. humifusa seeds was tested for the inhibition of nitric oxide (NO) production in liposaccharide (LPS)-stimulated RAW 264.7 cells using Griess reagent. The active constituents were isolated using bioassay-guided isolation methods. The effects of the active constituent on NO, proinflammatory cytokines, nuclear factor-kappa B (NF-κB) and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor (IκB) were evaluated by enzyme-linked immunosorbent assay (ELISA) and western blot analysis.Results: The seed extract of O. humifusa significantly attenuated LPS-induced NO production in RAW 264.7 cells (p < 0.05). Bioassay-guided fractionation resulted in the isolation of isoamericanin A as an active constituent. Isoamericanin A reduced LPS-induced production of NO, iNOS, and proinflammatory cytokines (TNF-α and IL-6) in a concentration-dependent manner (p < 0.05). Furthermore, the effect was accompanied by decreased translocation of NF-κB from the cytosol to the nucleus and the decreased phosphorylation of IκB in the cytosol induced by LPS (p < 0.05).Conclusion: The seed extract of O. humifusa and its active constituent, isoamericanin A, have antiinflammatory effects in LPS-stimulated RAW 264.7 cells, suggesting that they have potentials as antiinflammatory agents.
Keywords: Opuntia humifusa seeds, Isoamericanin A, Nitric oxide, RAW 264.7 cells, NF-kappa
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Comparison of the Plasma Metabolome Profiles Between the Internal Thoracic Artery and Ascending Aorta in Patients Undergoing Coronary Artery Bypass Graft Surgery Using Gas Chromatography Time-of-Flight Mass Spectrometry.
BackgroundThe left internal thoracic artery (LITA) has been used as the first conduit of choice in coronary artery bypass grafting (CABG) because of excellent long-term patency and outcomes. However, no studies have examined substances other than nitric oxide that could be beneficial for the bypass conduit, native coronary artery or ischemic myocardium. This study was conducted to evaluate differences in metabolic profiles between the LITA and ascending aorta using gas chromatography-time of flight-mass spectrometry (GC-TOF-MS).MethodsTwenty patients who underwent CABG using the LITA were prospectively enrolled. Plasma samples were collected simultaneously from the LITA and ascending aorta. GC-TOF-MS based untargeted metabolomic analyses were performed and a 2-step volcano plot analysis was used to identify distinguishable markers from two plasma metabolome profiles. Semi-quantitative and quantitative analyses were performed using GC-TOF-MS and enzyme-linked immunosorbent assay, respectively, after selecting target metabolites based on the metabolite set enrichment analysis.ResultsInitial volcano plot analysis demonstrated 5 possible markers among 851 peaks detected. The final analysis demonstrated that the L-cysteine peak was significantly higher in the LITA than in the ascending aorta (fold change = 1.86). The concentrations of intermediate metabolites such as L-cysteine, L-methionine and L-cystine in the 'cysteine and methionine metabolism pathway' were significantly higher in the LITA than in the ascending aorta (2.0-, 1.4- and 1.2-fold, respectively). Quantitative analysis showed that the concentration of hydrogen sulfide (H₂S) was significantly higher in the LITA.ConclusionThe plasma metabolome profiles of the LITA and ascending aorta were different, particularly higher plasma concentrations of L-cysteine and H₂S in the LITA
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