• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.23-26
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• 1995

The objectives of the present study are 1)to find the effect of the diameter of transpedicular screws on their fixational strength in pedicles under static pull-out loading, 2)to determine the biomechanical correlation between the pedicle diameter and the screw diameter, and 3)to find the effects of other factors in the screw design, such as materials, screw pitch, thread height and shape on their fixational strength. Biomechanical tests (Test I) were performed to evaluate the effect of the screw diameter on pull-out strength by using 60 porcine pedicls and six groups of custom-made pedicle screws with different diameters (the major and the minor diameter of the screws used in the testing varied from 4mm upto 9mm and from 3mm upto 8mm, respectively) while all other factors (materials, screw pitch, thread height and shape etc.) were fixed. In Test II, by using 61 porcine pedicles, the relationship between the ratio of the pedicle diameter and the screw diameter(=aspect ratio) of the custum-made screw and the pull-out strength of the screw was investigated. Test III was performed with 94 porcine pedicles and 8 different types of the commercial screws from 6 major productors in order to determine the effect of the screw diameter, pitch and the thread shape on the pull-out strength of the screw, respectively. The results of Test I showed that the axial pull-out resistance of the screw could be increased prportionaly to the screw diameter(P<0.05). But this increase in the pull-out resistance did not found when the screws of 4mm or 9mm in the diameter were employed. It was found from the results of Test II that the screws had its maximum pull-out resistant force when the aspect ratio ranging 40 - 69% (P<0.05). based on the results for the major diameter against the minor diameter of screw, the maximal pull-out resistance was found at 60-65% (P<0.05). According to these biomechanical testing results, it seems that the screw with a moderately large pitch is more desirable and the buttress-shaped screw can provide stronger fixation than the V-shape one can, if other designal factor and conditions were fixed.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.219-228
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• 2015

Excessive microglial activation and subsequent neuroinflammation lead to synaptic loss and dysfunction as well as neuronal cell death, which are involved in the pathogenesis and progression of several neurodegenerative diseases. Thus, the regulation of microglial activation has been evaluated as effective therapeutic strategies. Although dieckol (DEK), one of the phlorotannins isolated from marine brown alga Ecklonia cava, has been previously reported to inhibit microglial activation, the molecular mechanism is still unclear. Therefore, we investigated here molecular mechanism of DEK via extracellular signal-regulated kinase (ERK), Akt and nicotinamide adenine dinuclelotide phosphate (NADPH) oxidase-mediated pathways. In addition, the neuroprotective mechanism of DEK was investigated in microglia-mediated neurotoxicity models such as neuron-microglia co-culture and microglial conditioned media system. Our results demonstrated that treatment of anti-oxidant DEK potently suppressed phosphorylation of ERK in lipopolysaccharide (LPS, $1{\mu}g/ml$)-stimulated BV-2 microglia. In addition, DEK markedly attenuated Akt phosphorylation and increased expression of $gp91^{phox}$, which is the catalytic component of NADPH oxidase complex responsible for microglial reactive oxygen species (ROS) generation. Finally, DEK significantly attenuated neuronal cell death that is induced by treatment of microglial conditioned media containing neurotoxic secretary molecules. These neuroprotective effects of DEK were also confirmed in a neuron-microglia co-culture system using enhanced green fluorescent protein (EGFP)-transfected B35 neuroblastoma cell line. Taken together, these results suggest that DEK suppresses excessive microglial activation and microglia-mediated neuronal cell death via downregulation of ERK, Akt and NADPH oxidase-mediated pathways.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.134-140
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• 2008

The data on pesticide poisoning death toll during 2000-2005 was obtained from Korean National Statistical Office and analysed to find out any precautionary measures against pesticide poisonings. Pesticide poisoning death toll showed slightly increasing trend with year up to about 3500 in 2005. Most of the pesticide poisoning death cases were intentional self-poisoning accounting for more than 80% of total pesticide poisoning death. The pesticide most often implicated in poisoning death were paraquat dichloride, a non-selective herbicide and organophosphate/carbamate insecticides. The regional distribution of pesticide poisoning death showed urban 21.6% and rural area 78.4%. As for the occupation of the dead, agricultural, forestry and fishery workers accounted for 27.4% and non-agricultural workers was 72.6% of pesticide poisoning death. Therefore, government need to take some precautionary measures to reduce the number of pesticide poisoning cases. It is strongly recommended that pesticide regulatory authorities encourage and train the agricultural workers to use safe storage boxes and enforce strict regulation for the prevention for the prevention of highly toxic pesticides sales to non-agricultural workers.

• Journal of Korean Orthopaedic Sports Medicine
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• v.1 no.2
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• pp.109-114
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• 2002

The types of Alpine ski injuries have changed through the years in relationship to the development of skiing equipment. Modern skis, boots and bindings are better at protecting the tibia, which previously was almost as commonly injured as the knee. Since the 1980s, severe knee sprains, most of them involving the anterior cruciate ligament have tripled while injuries of the lower extremity below the knee diminished significantly. However, recent studies show no further improvements in either lower leg fractures or increase in the rates of ACL sprains has occurred. The use of carving skis presents an increased risk for sustaining isolated ACL injuries in more skilled skiers and less skilled skiers are more likely to sustain an ankle fracture than skiers using conventional skis. To restore the trend of diminishing lower leg injury rates, efforts will be needed to motivate skiers to have their equipment serviced by ski shop professionals following ASTM (American Society for Testing and Material) standard procedures. As of now, there are no boots, bindings or skis on the market designed to protect skiers from the ACL injury. The only method proven to reduce ACL injury Is a training program based on recognizing the circumstances that lead to ACL injury in skiing and to avoid these events.

• Journal of Korean Orthopaedic Sports Medicine
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• v.3 no.1
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• pp.73-80
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• 2004

Purpose: To compare the results of a miniopen repair with those of complete arthroscopic repair in medium and large sized full thickness rotator cuff tears. Materials and Methods: The thirty four(34) patients with medium and large sized complete rotator cuff tear were observed, Group I (complete arthroscopic repair) were 13 cases and group II (miniopen repair) were 21 cases. The tear sizes are from 1cm to 5cm. The average follow up periods are 24(range;12$\~$36) and 28(range; 12$\~$36) months. Subjective pain was evaluated with VAS (visual analogue scale) in rest state. ADL (Activity of Daily Living) and UCLA scoring system were used to evaluate clinical results. Results: At last follow-up periods, pain and functional scores were improved but they had not been shown statistical significance (p>0.05). In the group I and group II, there are no significant difference in VAS, ADL; UCLA score, satisfaction (p>0.05). Conclusions: In medium and large sized full thickness rotator cuff tears, there are no significant clinical results between the arthroscopic and miniopen group.

• The Journal of the Korea Contents Association
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• v.18 no.6
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• pp.504-517
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• 2018

The purpose of this study is to analyze the trends and contents of the research related to young children safety published in the domestic KCI and the candidate journals from 2010 to 2017. To analyze this, we selected 75 articles related to safety for young children published in the KCI and candidate journals from 2010 to 2017. A total of 75 papers were analyzed for frequency, percentage and ${\chi}^2$ using the SPSS Win 23.0 program. The main results of this study are as follows: First, the articles related to young children safety were published the most in 2016 and 2017 and related to infant safety were the least. Next, more than half of the research methods were conducted by quantitative research methods. The results of this study are meaningful in that it presents the necessity of safety education by analyzing trends and contents of research related to young children safety in situations where safety accidents for young children are frequent and the importance of young children safety is more emphasized. It is expected that this research will provide basic data on research topics such as disaster safety who need further research.

• Journal of Korea Technology Innovation Society
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• v.15 no.2
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• pp.443-460
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• 2012

Technology is closely related to industrial development and various studies have been performed to understand the linked structure for knowledge flow between the technology and industry. The research, however, wasn't carried out to flow for Korea National Research and Development projects. In this study, linked structure for technology-industry was discussed by utilizing patent data performed in actual National R&D using NTIS Information of the national research and development, and then it was analyzed how knowledge flows between the technology and industry are flowing. It should be defined that the individual applications expected by researchers at the start of the research and technology-industry applications actually applied from the research performances after research was completed. As a result, it was confirmed in most projects the flow of knowledge was occurring to predicted industries before the start of the R&D. However, the technology was applied to unexpected industry in three industries such as Y09(medical, precision and optical instruments), Y10(electrical and mechanical equipment), Y11(automotive and transportation equipment). The results of this study will be able to contribute to planning for efficient investment strategy of technology-industry by investigating the technology-industry knowledge flow relations of national R&D projects.

• Journal of Korea Technology Innovation Society
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• v.21 no.2
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• pp.767-787
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• 2018

Technology-driven innovation and job-creation has each been the subject of much scholarly attention, but have largely been considered separately rather than in conjunction with each other. While the previous literature on economics pinpointed the macro effects on industry-level, this study explores the micro-level comparisons on innovation sources over the employment and financial performances. The PSM (propensity-score matching) analysis presents that firms, involved in an inward technology, tend to have higher employees with dominant technology capabilities than in-house R&D firms. The in-house R&D firms, on the contrary, have superior financial performances, suggesting that external technology commercialized firms suffer from low transformative efficiency. The mediation test analysis corroborates that the external technology-driven innovation induces more human resources in internalizing the exogenous technology. The positive relationship between R&D innovation and employment allow verification of the government's intervention in the promotion of technology commercialization in public sector. On the other hand, it also signals that the policy needs to enhance the recipient firms' commercializing capacity rather than a 'one-hit' transaction.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.219-224
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• 2014

In order to develop a new anti-diabetic ${\alpha}$-glucosidase inhibitor, we compared the ${\alpha}$-glucosidase inhibitory activity of the cell-free extracts of 48 strains of yeasts isolated from Korean fermented foods, and found that Pichia burtonii Y257-7 exhibited the highest ${\alpha}$-glucosidase inhibitory activity of 55.6%. The ${\alpha}$-glucosidase inhibitor was maximally produced when Pichia burtonii Y257-7 was cultured in LB broth (initial pH of 6.0) at $28^{\circ}C$ for 24 h. The ${\alpha}$-glucosidase inhibitor, partially purified by Sephadex G-50 gel permeation chromatography and systematic solvents extraction, revealed potent hypoglycemic effects in normal rats and streptozotocin-induced diabetic rats after the oral administration of starch.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.2
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• pp.191-197
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• 2005

A new method, ToxTemp (TOXcity test based on TEMPerature control) using Ceridaphnia dubia was applied to evaluate the toxicity of insecticide materials and compared with the standard 48 hr acute bioassay. BPMC, diazinon and fenitrothion may cause the inhibition to the biological process in sewage treatment plant and need to detect toxicity within short contact time. The ToxTemp method showed sensitive detection with more shorter contact of 1-1.5 hr time than that of the standard 48 hr acute bioassay. To evaluate toxicity of real wastewater/sewage, the inhibition rate of nitrification and oxygen uptake rate (OUR) using activated sludge, the standard 48hr acute bioassay and ToxTemp method using C. dubia were compared, respectively. On the basis of the inhibition rate of nitrification, the OUR test showed the less sensitive results at the relatively strong toxic sewage. On the other hands, the standard 48hr acute bioassay and ToxTemp method using C. dubia represented the toxicity of each wastewater/sewage with high sensitivity. Even the slightly low (about 1.5%) sensitivity, the ToxTemp method showed the high applicability to the real site of sewage treatment plant.