• Journal of Energy Engineering
• /
• v.23 no.1
• /
• pp.46-57
• /
• 2014

This study analyzes whether the value-added structure of Korean wind power industry exhibits a virtuous cycle through the value chain(VC) within wind power firms and the value system(VS) among the wind power industries, using a regression analysis based on a survey about Korean wind power companies. According to the VC, the government's R&D support is analyzed to have contributed to an increase in the R&D investments of the wind power companies. An increase in corporates' R&D investments has led to an increase in corporates' R&D outputs, and in turn, induced a remarkable increase in the amounts of production. But an increase in production has not led to a decrease in the costs of production, not resulting in an increase in profit rates per sales amount. In addition, while an increase in profit rates is analyzed to have contributed to an increase in production, this did not induce further investments in corporate's R&D. The virtuous cycle of the value chain in Korean wind power firms is, therefore, analyzed to be weak. Next, the VS is analyzed by dividing the whole chain into the system group including rotor blades, gear boxes, and power generators, and the structure group, such as towers. Two groups are analyzed to have mutually positive effects in the processes of the government's support for corporates' R&D, corporates' investment in R&D, R&D outputs, and profit rates per sales amount. Such mutual positive effects are, however, not found in the processes of the amounts of production and the costs of production. These results demonstrates that the value system of Korean wind power industry is not completed. This study has a policy implication to need further efforts to create the virtuous cycle in the VC and VS of Korean wind power industry.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.16 no.1
• /
• pp.24-33
• /
• 2016

Mucopolysaccharidosis type VI (MPS VI) is a rare disease caused by the mutation of ARSB with prevalence range from 1/5,000 in northeast Brazil to 1/2,057,529 births in Czech Republic. In Asia, there is only one published figure in Taiwan of about 1/833,000 births. The exact prevalence in the Korean population is unknown, but we estimated the incidence of MPS VI is about 0.03/100,000 live births. Enzyme replacement therapy (ERT) with recombinant human Arylsulfatase B (rhASB) is a modality for the treatment of MPS VI that reduces the excretion of urine glycosaminoglycan (GAG) and improves joint motion, pulmonary function, and endurance. We presented the clinical features, molecular analysis and outcome of ERT in three Korean MPS VI patients. All patients had the typical characteristic clinical features of MPS IV. Short stature, dysostosis multiplex, corneal opacity and valvular heart disease were found at first presentation, while restrictive lung disease and carpal tunnel syndrome developed later in all patients. Molecular analysis demonstrated novel missense and nonsense mutation in the patients, including p.Ile 67Ser, p.Gly328Arg, $p.Arg191^*$, p.Asp352Asn, and p.Gly17Asp. After ERT, urine GAG was decreased in all patients. Skeletal involvement, corneal opacity, heart valve abnormalities and pulmonary function were not improved with ERT, but it had a better outcome on regarding joint motion and endurance. One patient underwent allogeneic bone marrow transplantation (BMT) prior to ERT, but their clinical response was not improved much after BMT. This study demonstrates clinical phenotypes and molecular analysis of the severe form of MPS VI in Korean patients.

• Journal of the Mineralogical Society of Korea
• /
• v.19 no.4 s.50
• /
• pp.277-289
• /
• 2006

This study was carried out to find a new material having high removal efficiency for the harmful red tide. C. polykrikoides grow very fast and accumulate into dense and visible patches near the surface of the seawater ('Water bloom'). Some mineral medicines and Hwangto (reddish soil consist of clay minerals and Fe-oxides) were used in this study to remove C. polykrikoides. The pre-determined sprinkling ratio of mineral vs. seawater which contains approximately 5,000 cells/mL of C. polykrikoides was 10 g/L. In order to quantify the removal efficiency, the density of living cells was measured by counting with the Intervals of 0, 10, 30, and 60 minutes after sprinkling. Five Hwangtos feom different localities were examined in this study. It is found that a material with a high concentration of Fe and Al was the most effective to remove C. polykrikoides. After the sprinkling of the Hwangto showing the best removal efficiency in the test, 99% of total algaes were found to be eliminated within 60 minutes. Jeokeokji showed the highest removal efficiency among clay mineral medicines(92% removal efficiency after 60 minutes), and the rests in decreasing order are as follows: Gamto (91%) > Baekseokji (89%) > Hydromica (81%). In addition, Fe-oxide mineral medicine similarly looking as fine-grained earthy Daejaseok showed 100% removal efficiencyafter 30 minutes, and Wooyoeryang, 95% after 60 minutes. It is noted that even little addition (1 g/L) of Daejaseok, 10% of Hwangto concentration into seawater showed the removal efficiency of 100% after 60 minutes. From the results, it could be concluded that the fine-grained earthy Daejaseok was the most effective natural mineral medicine to remove the C. polykrikoides from seawater. Under the microscope the removal mechanism was found to be activated in the following order: adsorption, swelling of chain colony, chain colony crisis and algaecide.

• Nuclear Medicine and Molecular Imaging
• /
• v.41 no.3
• /
• pp.234-240
• /
• 2007

Purpose: In this study we propose a block-iterative method for reconstructing Compton scattered data. This study shows that the well-known expectation maximization (EM) approach along with its accelerated version based on the ordered subsets principle can be applied to the problem of image reconstruction for Compton camera. This study also compares several methods of constructing subsets for optimal performance of our algorithms. Materials and Methods: Three reconstruction algorithms were implemented; simple backprojection (SBP), EM, and ordered subset EM (OSEM). For OSEM, the projection data were grouped into subsets in a predefined order. Three different schemes for choosing nonoverlapping subsets were considered; scatter angle-based subsets, detector position-based subsets, and both scatter angle- and detector position-based subsets. EM and OSEM with 16 subsets were performed with 64 and 4 iterations, respectively. The performance of each algorithm was evaluated in terms of computation time and normalized mean-squared error. Results: Both EM and OSEM clearly outperformed SBP in all aspects of accuracy. The OSEM with 16 subsets and 4 iterations, which is equivalent to the standard EM with 64 iterations, was approximately 14 times faster in computation time than the standard EM. In OSEM, all of the three schemes for choosing subsets yielded similar results in computation time as well as normalized mean-squared error. Conclusion: Our results show that the OSEM algorithm, which have proven useful in emission tomography, can also be applied to the problem of image reconstruction for Compton camera. With properly chosen subset construction methods and moderate numbers of subsets, our OSEM algorithm significantly improves the computational efficiency while keeping the original quality of the standard EM reconstruction. The OSEM algorithm with scatter angle- and detector position-based subsets is most available.

• Journal of Life Science
• /
• v.24 no.11
• /
• pp.1180-1186
• /
• 2014

Autophagy, the lysosomal degradation pathway, is an intracellular recycling system that is necessary for the metabolic benefits of exercise and for producing lasting beneficial effects of exercise in various diseases. However, the most recent studies have only examined the effect of a single bout of exercise or resistance exercise on autophagic responses. To determine the differential effects of acute and chronic exercise on the expression of autophagy-related genes in D. melanogaster, white-eyed mutant D. melanogaster were assigned randomly to four groups: control, acute exercise, 2 hr chronic exercise, and 3 hr chronic exercise. The flies were exercised using a mechanized platform known as the Power Tower. Our results revealed that a single bout of exercise resulted in increased mRNA levels of the Atg8a gene (~20%, p<0.05). However, Atg1 and Atg6 mRNA expression were not induced by acute exercise. Transcript levels of Atg6 (~29%, p<0.05) related to the nucleation of autophagosomes were significantly induced by 2 hr of chronic exercise. However, this chronic exercise was not enough to increase Atg1 and Atg8a mRNA expression. On the other hand, 3 hr of exercise for 7 days significantly increased Atg1, Atg6, and Atg8a gene expression-about 57%, 37%, and 71%, respectively (p<0.05). These results suggest that a single bout of exercise is not enough to induce full activation of selected autophagy-related genes in D. melanogaster. Our results demonstrated that chronic regular exercise induced autophagy-related gene expression, suggesting that chronic regular exercise training might be required to activate autophagic responses important for producing beneficial effects of exercise in various diseases.

• Childhood Kidney Diseases
• /
• v.8 no.2
• /
• pp.205-213
• /
• 2004

Purpose: To evaluate the clinical manifestations of various glomerular diseases in children, a clinicopathological study was performed in 52 children who had renal biopsy. The type and relative incidence of the glomerular pathologies were analyzed, and the clinical predictability and usefulness of renal biopsy in glomerular diseases were assessed. Methods: Medical records of fifty two children with renal disease who had undergone percutaneous renal biopsy under ultrasonic guidance at Chungnam University Hospital from October 1995 to August 2003 were reviewed. In addition, we compared the clinical findings before renal biopsy with the pathological diagnosis. Results: The male to female ratio was 1.6:1 and they were $9.8\pm2.6$ years old on average. The chief complaints for biopsy were hematuria in 22 cases which was the most common (42.3%), proteinuria in 16 cases(30.8%), and hematuria & proteinuria(26.9%). Among the 22 cases of hematuria, there were 15 cases of gross hematuria(68.2%) and 7 cases of microscopic hematuria(31.8%). In terms of histopathologic diagnosis, most of them were primary glomerular diseases(84.6%), which included IgA nephropathy(28.8%), thin glomerular basement membrane disease(25.0%), focal segmental glomerulosclerosis(FSGS)(11.5%), membranous proliferative glomerulonephritis(7.7%), minimal change lesion(3.8%), acute poststreptococcal glomerulonephritis(3.8%) and membranous glomerulonephritis(3.8%). The clinical manifestations and pathologic diagnosis were not correlated. Conclusion: The clinical manifestations could not predict the pathological diagnosis. Therefore, renal biopsy would be inevitable in diagnosis of glomerular diseases for effective management and assessment of prognosis.

• Clinical and Experimental Pediatrics
• /
• v.51 no.3
• /
• pp.307-314
• /
• 2008

Purpose : Capsaicin, the major pungent ingredient in red pepper, has long been used in spices and food additives. It has been recently shown to induce apoptosis in several cell lines through a not well known mechanism. The aim of this study was to investigate the apoptosis-inducing effect of capsaicin on gastric cancer cells, and to provide valuable information concerning the application of capsaicin for therapeutic purposes. Methods : Cultured SNU-668 cells were treated with capsaicin. We analyzed cell survival by trypan blue and crystal violet analysis, cell cytotoxicity by MTT assay, apoptosis by nuclear condensation and DNA fragmentation, bcl-2 and bax mRNA expression by RT-PCR, and the expression of apoptosis related proteins by Western immunoblot analysis. In order to assess whether the growth inhibitory effect of anticancer drugs is enhanced by capsaicin, we investigated the effects of cell cytotoxicity and the expression of apoptosis related proteins of etoposide and adriamycin treated with capsaicin in cells. Results : Capsaicin inhibited growth of SNU-668 cells in a dose-dependent manner. This inhibitory effect of capsaicin on cell growth was mainly due to the induction of apoptosis as evidenced by DNA fragmentation, nuclear condensation and the expression of apoptosis related proteins. Furthermore, capsaicin prominently reduced the ratio of anti-apoptotic Bcl-2 to pro-apoptotic Bax and consequently increased caspase-3 activity. The cells treated with capsaicin were more sensitive to death induced by etoposide and adriamycin than the cells without capsaicin. Conclusion : These results demonstrate that capsaicin efficiently induced apoptosis in SNU-668 cells through a caspase-3-dependent mechanism and sensitizes cancer cells to anticancer drugs toward apoptotic cell death, which may contribute to its anticancer effect and chemosensitizer function against gastric cancer.

• Journal of Life Science
• /
• v.30 no.10
• /
• pp.886-895
• /
• 2020

The development of novel peptide antibiotics with potent antimicrobial activity and anti-inflammatory activity is urgently needed. In a previous work, we performed an in-silico analysis of the Papilio xuthus transcriptome to identify putative antimicrobial peptides and identified several candidates. In this study, we investigated the antibacterial and anti-inflammatory activities of papiliocin 3, which was selected bioinformatically based on its physicochemical properties against bacteria and mouse macrophage Raw264.7 cells. Papiliocin 3 showed antibacterial activities against E. coli and S. aureus without inducing hemolysis and decreased the nitric oxide production of the lipopolysaccharide-induced Raw264.7 cells. Moreover, ELISA and Western blot analysis revealed that papiliocin 3 reduced the expression levels of pro-inflammatory enzymes, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and prostaglandin E₂ (PGE₂). In addition, we examined whether papiliocin 3 could inhibit the expression of pro-inflammatory cytokines (interleukin-6 and interleukin-1β) in LPS-induced Raw264.7 cells. We found that papiliocin 3 markedly reduced the expression level of cytokines through the regulation of mitogen-activated protein kinases (MAPK) and nuclear factor kappa B (NF-κB) signaling. We also confirmed that papiliocin 3 binds to bacterial cell membranes via a specific interaction with lipopolysaccharides. Collectively, these findings suggest that papiliocin 3 could be a promising molecule for development as a novel peptide antibiotic.

• Neonatal Medicine
• /
• v.17 no.2
• /
• pp.181-192
• /
• 2010

Purpose: Current studies have demonstrated the neuroprotective effects of dizocilpine (MK-801) in many animal models of brain injury, including hypoxic-ischemic (HI) encephlopathy, trauma and excitotoxicity, but limited data are available for those during the neonatal periods. Here we investigated whether dizocilpine can protect the developing rat brain from HI injury via anti-apoptosis. Methods: In an in vitro model, embryonic cortical neuronal cell culture of Sprague-Dawley (SD) rats at 18-day gestation was done. The cultured cells were divided into three groups: normoxia (N), hypoxia (H), and hypoxia treated with dizocilpine (HD). The N group was prepared in 5% $CO_2$ incubators and the other groups were placed in 1% $O_2$ incubators (94% N2, 5% $CO_2$) for 16 hours. In an in vivo model, left carotid artery ligation was done in 7-day-old SD rat pups. The animals were divided into six groups; hypoxia (N), hypoxia (H), hypoxia with sham-operation (HS), hypoxia with operation (HO), HO treated with vehicle (HV), and HO treated with dizocilpine (HD). Hypoxia was made by exposure to a 2 hour period of hypoxic incubator (92% N2, 8% $O_2$). Results: In the in vitvo and in vivo models, the expressions of Bcl-2 in the hypoxia groups were reduced compared to the normoxia group. whereas those in the dizocilpine-treated group were increased compared to the hypoxia group. However. the expressions of Bax and caspase-3 and the ratio of Bax/Bcl-2 were revealed reversely. Conclusion: Dizocilpine has neuroprotective property over perinatal HI brain injury via anti-apoptosis.

• Journal of Chest Surgery
• /
• v.35 no.11
• /
• pp.792-798
• /
• 2002

Although there is a controversy on the optimal timing for active infective endocarditis(IE), recently good results of early surgical intervention have been published. Herein, we analyzed the results of surgery for active IE according to the duration of preoperative antibiotic treatment. Material and Method : Retrospectively, we analyzed 51 patients who underwent operation for active IE at the department of thoracic and cardiovascular surgery of Samsung medical center from Mar. 1995 to Oct. 2001. Male to female ratio was 39:12, mean age of the patients was 44.5$\pm$17.8 years(range : 13~74). Infected valves were mitral valve in 17(33.3%), aortic valve in 15(29.4%), mitral and aortic valve in 12(23.5), and tricuspid valve in 5(9.8%) cases. Among them, prosthetic valve endocarditis was present in 10(19.6%) cases. Infecting organism was Staphylococcus in 19(37.3%), Streptococcus in 17(33.3%), Enterococcus in 3(5.9%), fungus in 3(5.9%), and other bacteria in 5(9.8%) cases. Organism was not isolated in 6(11.8%) cases, and two organisms were isolated in 4(7.8%) cases. Dividing these patients into two groups according to the duration of preoperative antibiotic treatment(A: less than 7 days, B: more than 8 days), we compared the surgical results between the two groups. Result : There were 16 cases in group A and 35 in group B. Annular reconstruction was performed in 10(62.5%) cases in group A and 10(28.6%) cases in group B, which has statistically significance(p＜0.05). There was one early death in group B. Forty nine patients(96.1%) except two were followed up with mean follow-up duration of 28.7 $\pm$ 23.6 months. Endocarditis was recurred in one in group A, and two in group B. Three late deaths occurred in group B. Recurrence rate and survival were not statistically different between the two groups. Conclusion : Early surgery for active IE showed good results as the result of that which was performed after prolonged antibiotic treatment; therefore, we believe that early surgery for active If could effectively eradicate the infection.