412 research outputs found

    The systematic capacity for technological absorption (SCTA) and international technology transfer (ITT): how some Korean firms successfully exploit Russian technology

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    This thesis examines issues of international technology transfer (ITT), focusing on the exploitation of foreign technology between countries with contrasting strengths and capabilities. The tendency in ITT is that it has mostly been limited to the triad countries and to some latecomer economies in East Asia. An explanation for this tendency is that the extent of this shared common ground between countries directly affects a recipient country’s capability to exploit and absorb foreign knowledge. This thesis examines cases of ITT which successfully occurred without such common grounds and offers explanations for specific cases. The conceptual framework was developed to explain how such extraordinary capabilities are created in order to overcome barriers to technological transfer. In addition, several other mechanisms and special factors are hypothesised as candidates for explaining the technology transfer process as one involving bridging and overcoming the barriers. These hypotheses are examined in relation to the Korean-Russian technology transfer, the main target of the investigation. Korea and Russia are countries that had no interaction prior to or during the Cold War period and shared little or no common ground. Nonetheless, after 1990 Korean firms have actively attempted to exploit Russian technology and some of them, though not many, have succeeded in exploiting and commercialising Russian technology. Important contextual issues for this examination are the military and mission-focused body of Russia’s technological knowledge and the often cheaper importation of Western technology. Taking these contextual issues into account, this thesis identifies two principal issues that were overcome in the cases of successful technology transfer: a) the tacitness of Russian technological knowledge and b) the locality of the Russian “context of origin” in terms of the socio-cultural, economic, and political environment. The empirical content of the thesis involves a mixed approach with document analysis, interviews, a survey, and case studies. The research results show that the public agency programme’s facilitating role as an intermediary (developed by the Korean government) creates the extra capacity to bridge the gaps involved in adapting Russian technology

    Expression of Functional Recombinant Mussel Adhesive Protein Mgfp-5 in Escherichia coli

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    Mussel adhesive proteins have been suggested as a basis for environmentally friendly adhesives for use in aqueous conditions and in medicine. However, attempts to produce functional and economical recombinant mussel adhesive proteins (mainly foot protein type 1) in several systems have failed. Here, the cDNA coding for Mytilus galloprovincialis foot protein type 5 (Mgfp-5) was isolated for the first time. Using this cDNA, we produced a recombinant Mgfp-5 fused with a hexahistidine affinity ligand, which was expressed in a soluble form in Escherichia coli and was highly purified using affinity chromatography. The adhesive properties of purified recombinant Mgfp-5 were compared with the commercial extracted mussel adhesive Cell-Tak by investigating adhesion force using atomic force microscopy, material surface coating, and quartz crystal microbalance. Even though further macroscale assays are needed, these microscale assays showed that recombinant Mgfp-5 has significant adhesive ability and may be useful as a bioadhesive in medical or underwater environments.X119196sciescopu

    Prevention of hypoglycemia-induced neuronal death by minocycline

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    Diabetic patients who attempt strict management of blood glucose levels frequently experience hypoglycemia. Severe and prolonged hypoglycemia causes neuronal death and cognitive impairment. There is no effective tool for prevention of these unwanted clinical sequelae. Minocycline, a second-generation tetracycline derivative, has been recognized as an anti-inflammatory and neuroprotective agent in several animal models such as stroke and traumatic brain injury. In the present study, we tested whether minocycline also has protective effects on hypoglycemia-induced neuronal death and cognitive impairment. To test our hypothesis we used an animal model of insulin-induced acute hypoglycemia. Minocycline was injected intraperitoneally at 6 hours after hypoglycemia/glucose reperfusion and injected once per day for the following 1 week. Histological evaluation for neuronal death and microglial activation was performed from 1 day to 1 week after hypoglycemia. Cognitive evaluation was conducted 6 weeks after hypoglycemia. Microglial activation began to be evident in the hippocampal area at 1 day after hypoglycemia and persisted for 1 week. Minocycline injection significantly reduced hypoglycemia-induced microglial activation and myeloperoxidase (MPO) immunoreactivity. Neuronal death was significantly reduced by minocycline treatment when evaluated at 1 week after hypoglycemia. Hypoglycemia-induced cognitive impairment is also significantly prevented by the same minocycline regimen when subjects were evaluated at 6 weeks after hypoglycemia. Therefore, these results suggest that delayed treatment (6 hours post-insult) with minocycline protects against microglial activation, neuronal death and cognitive impairment caused by severe hypoglycemia. The present study suggests that minocycline has therapeutic potential to prevent hypoglycemia-induced brain injury in diabetic patients

    Feature coordinate estimation by time differenced vision/GPS/INS

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    This paper proposes a multi-baseline method to estimate absolute coordinates of point clouds and the camera attitude parameter utilizing feature points in successive images. Conventionally, 3D map generation methodologies have been based on images acquired by aerial or land vehicles. Pixels corresponding to known landmarks are manually identified at first. Next, the coordinates are directly geo-referenced and automatically allocated to pixels with high-quality Global Positioning System (GPS) and Inertial Navigation System (INS). However, it is difficult to obtain accurate coordinates by the conventional methodology with low-cost GPS and INS. With camera positions and attitude parameters, image-based point clouds can be compensated accurately. A simulation was carried out to evaluate the performance of the proposed method

    Low roll-off of efficiency at high current density in phosphorescent organic light emitting diodes

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    The authors demonstrate that the reduction of quantum efficiency with increasing current density in phosphorescent light emitting diodes (PhOLEDs) is related to the formation of excitons in hole transporting layer based on the analysis of emission spectra and exciton formation zone. Low roll-off of efficiency in a PhOLED was achieved using dual emitting layers (D-EMLs) by confining the exciton formation near the interface between the emitting layers. The external quantum efficiency was maintained almost constant up to 22 mA/cm2 (10 000 cd/m2) by adopting the D-EMLs in Ir(ppy)3 based PhOLEDs, resulting in high external quantum efficiency (ext=13.1%) at high luminance.This work was supported by the Ministry of Commerce, Industry and Energy of Korea through the OLED center, Samsung SDI, Dongwoo Finechem, and CKC Program

    Endothelin A Receptor Blockade Influences Apoptosis and Cellular Proliferation in the Developing Rat Kidney

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    Endothelin systems are believed to play important roles in the emergence and maintenance of functions of various organs during perinatal development, including the kidney. The present study was designed to investigate the roles of endothelin systems on physiologic renal growth and development. Newborn rat pups were treated with either Bristol-Myers Squibb-182874 (30 mg/kg/day), a selective endothelin A receptor (ETAR) antagonist, or vehicle for 7 days. To identify cellular changes, kidneys were examined for apoptotic cells by terminal deoxynucleotide transferase-mediated nick-end labeling stain and proliferating cell nuclear antigen (PCNA) by immunohistochemical (IHC) stain. To clarify the molecular control of these processes, immunoblots and reverse transcriptase-polymerase chain reaction for Clusterin, Bcl-2, Bcl-XL, Bax, and p53 were performed. ETAR antagonist treatment resulted in reduced kidney weights, decreased PCNA-positive proliferating cells, and increased apoptotic cells. The protein expressions of renal Bcl-XL and Bax in the ETAR antagonist-treated group were significantly decreased, whereas the mRNA expressions of these genes were not changed. There were no significant differences in the expressions of Clusterin, Bcl-2, and p53. In conclusion, inhibition of endogenous endothelins impairs renal growth, in which decreased cellular proliferation, increased apoptosis and decreased expressions of renal Bcl-XL and Bax are possibly implicated

    Obesity and hepatocellular carcinoma in patients receiving entecavir for chronic hepatitis B

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    Background/Aims This study aimed to clarify the effect of obesity on the development of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients receiving antiviral treatment. Methods This study applied a retrospective analysis to a historical cohort in Bundang Jesaeng Hospital. In total, 102 CHB patients were treated with entecavir as an initial treatment for CHB and checked for obesity using a body composition analyzer. Hepatic steatosis was measured semiquantitatively using Hamaguchi’s scoring system in ultrasonography. Risk factors for the development of HCC were analyzed, including obesity-related factors (body mass index [BMI], waist circumference [WC], waist-to-hip ratio [WHR], visceral fat area [VFA], and hepatic steatosis). Results The median follow-up duration of the patients was 45.2 months (interquartile range: 36.0-58.3 months). The cumulative incidence rates of HCC at 1 year, 3 years, and 5 years were 0%, 5.3%, and 9.0%, respectively. Univariable analysis revealed that the risk factors for HCC development were a platelet count of <120,000 /mm2 (hazard ratio [HR]=5.21, P=0.031), HBeAg negativity (HR=5.61, P=0.039), and liver cirrhosis (HR=10.26, P=0.031). Multivariable analysis showed that the significant risk factor for HCC development was liver cirrhosis (HR=9.07, P=0.042). However, none of the obesity-related risk factors were significantly associated with HCC: BMI ≥25 kg/m2 (HR=0.90, P=0.894), WC ≥90 cm (HR=1.10, P=0.912), WHR ≥0.9 (HR=1.94, P=0.386), VFA ≥100 cm2 (HR=1.69, P=0.495), and hepatic steatosis (HR=0.57, P=0.602). Conclusion HCC development is associated with liver cirrhosis but not obesity-related factors in CHB patients receiving entecavir

    Congenital Cerebellar Mixed Germ Cell Tumor Presenting with Hemorrhage in a Newborn

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    We report here on a neonate with congenital cerebellar mixed germ cell tumor, and this initially presented as cerebellar hemorrhage. Postnatal cranial ultrasonography revealed an echogenic cerebellar mass that exhibited the signal characteristics of hemorrhage rather than tumor on MR images. The short-term follow-up images also suggested a resolving cerebellar hemorrhage. One month later, the neonate developed vomiting. A second set of MR images demonstrated an enlarged mass that exhibited changed signal intensity at the same site, which suggested a neoplasm. Histological examination after the surgical resection revealed a mixed germ cell tumor
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