• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.927-935
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• 2019

Screw-failure accidents in small ships frequently occur in coastal waters. In particular, vessels' propulsion systems are frequently coiled due to objects such as fish-nets and ropes that float on the sea. The failure of the ship's propulsion system can cause primary accidents such as ship operation delays and drifting due to loss of power; furthermore, the possibility of secondary accidents such as those involving operators in the underwater removal of rope stuck in a propeller. Ships that do not have the proper tools to solve these problems must be either lifted onto land to be repaired or divers must dive directly under the ship to solve the problem. Accordingly, some small vessels have been equipped with rope-cutter devices on the propeller shaft to prevent ship propeller system accidents in recent years; however, they are not being applied efficiently due to the cost and time of installation. To solve these problems, this study develops an underwater rope-cutter device and controller for the removal of propeller and shaft foreign material in small vessels. This device has simple structures that use the principle of a saw. Meteor gears and crank pins were used for the straight-line rotation of saw blades of the underwater rope-cutters to allow for long strokes. Furthermore, the underwater rope-cutting machines can be operated by being connected to the ship battery. The user, a non-professional, can ensure convenience and stability by applying reverse current prevention and a speed control circuit so that it can be used more conveniently and safely.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1308-1316
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• 2008

Propionibacterium acnes is known to playa pivotal role in the pathogenesis of acne vulgaris. CBT-SL5 is one of the antimicrobial peptides from Enterococcus faecalis SL5, and it has shown antimicrobial activity against P. acnes. The aim of this study was to investigate the anti-inflammatory effect of CBT-SL5 on the inflammation induced by P. acnes in cultured human keratinocyes. Cultured human keratinocytes derived from neonatal foreskin were treated with heat-killed P. acnes to induce inflammation, and then various concentrations of CBT-SL5 were added to the P. acnes-treated keratinocytes. The mRNA expression and protein secretion of interleukin (IL)-8, an inflammation marker, was analyzed by real-time reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. We also analyzed the nuclear factor-kappa B (NF-$\kappaB$) p65 translocation by performing immunofluorescent staining. P. acnes treatment up regulated the IL-8 mRNA expression in the keratinocytes, and this was brought about through both toll-like receptor (TLR)2 and TLR4. At the concentrations of 10, 50, and 100 ng/ml, CBT-SL5 significantly down regulated the P. acnes-induced IL-8 mRNA expression and protein production (p<0.05). At 6 hand 12 h of the treatment, CBT-SL5 significantly suppressed the P. acnes-induced IL-8 mRNA expression. Secretion of IL-8 protein was significantly reduced at 24 h. The functional inhibitory activity of CBT-SL5 was shown by CBT-SL5 suppressing the P. acnes-induced NF-$\kappaB$ translocation from the cytoplasm to the nucleus. These results demonstrated that CBT-SL5 suppressed the P. acnes-induced IL-8 expression in keratinocytes. Therefore, CBT-SL5 may be a novel anti-inflammatory treatment for acne.

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1566-1575
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• 2017

MicroRNAs (miRNAs) are abundant in bovine milk and milk derived from other livestock, and they have functional roles in infants and in the secretion process of mammary glands. However, few studies have evaluated miRNAs in dairy processes, such as during cheese making and ripening. Thus, we investigated the characteristics of milk-derived miRNAs during the manufacturing and ripening of Camembert cheese as well as the microbiota present using the quantitative reverse transcription polymer chain reaction (RT-qPCR) and 16S rRNA pyrosequencing, respectively. Pyrosequencing showed that the cheese microbiota changed dramatically during cheese processing, including during the pasteurization, starter culture, and ripening stages. Our results indicated that the RNA contents per $200mg/200{\mu}l$ of the sample increased significantly during cheese-making and ripening. The inner cheese fractions had higher RNA contents than the surfaces after 12 and 22 days of ripening in a time-dependent manner (21.9 and 13.2 times higher in the inner and surface fractions than raw milk, respectively). We performed a comparative analysis of the miRNAs in each fraction by RT-qPCR. Large amounts of miRNAs (miR-93, miR-106a, miR-130, miR-155, miR-181a, and miR-223) correlated with immune responses and mammary glands were present in aged cheese, with the exception of miR-223, which was not present on the surface. Considerable amounts of miRNAs were also detected in whey, which is usually disposed of during the cheese-making process. Unexpectedly, there were no significant correlations between immune-related miRNAs and the microbial populations during cheese processing. Taken together, these results show that various functional miRNAs are present in cheese during its manufacture and that they are dramatically increased in amount in ripened Camembert cheese, with differences according to depth.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.1
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• pp.1-7
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• 2007

Altered environmental gravity, including both hypo- and hypergravity, may result in space adaptation syndrome. To explore the characteristics of this adaptive plasticity, the expression of immediate early gene c-fos mRNA in the vestibular related tissues following an exposure to hypergravity stimulus was determined in rats. The animals were subjected to a force of 2 g (twice earth's gravity) for 1, 3, or 12 h, and were examined poststimulus at 0, 2, 6, 12, and 24 h. RT-PCR (reverse transcription polymerase chain reaction) and real-time quantitative RT-PCR were adopted to analyze temporal changes in the expression of c-fos mRNA. The hypergravity stimulus increased the expression of c-fos mRNA in the vestibular ganglion, medial vestibular nucleus, inferior vestibular nucleus, hippocampus, cerebellum, and cortex. The peak expression occurred at 0 h poststimulation in animals stimulated with hypergravity for 1 h, and at 6 h poststimulus in those stimulated for 3 h. In contrast, those stimulated for 12 h exhibited dual peaks at 0 and 12 h poststimulus. Bilateral labyrinthectomy markedly attenuated the degree of c-fos mRNA expression. Glutamate receptor antagonist also dramatically attenuated the degree of c-fos mRNA expression. These results indicate that expression of c-fos mRNA in response to hypergravity occurs in the vestibular related tissues of the central nervous system, in which peripheral vestibular receptors and glutamate receptors play an important role. The temporal pattern of c-fos mRNA expression depended on the duration of the hypergravity stimulus.

• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.775-782
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• 2001

Recently the use of Linux OS is increasing to tremendous figures. But due to the fact that Linux is distributed on an open-source policy, the need of security is an upcoming question which leads to widespread development of security on a Linux based environment. Cryptography, however, can cause various problems because of difficulty of key management. A lot of researchers have been concentrating on the key recovery technique to eliminate the reverse effect of using these kinds of security and to promote positive aspects of using it. In this thesis I am suggesting an mechanism based on the key recovery technique, as a method to save time in recovery and resetting a disconnection between two end-users through IPSec (IP Security) protocols in a VPN (Virtual Private Network) environment. The main idea of the newly suggested mechanism, KRFSH (Key Recovery Field Storage Header), is to store the information of the session in advance for the case of losing the session information essential to establish a tunnel connection between a SG and a host in the VPN environment, and so if necessary to use the pre-stored information for recovery. This mechanism is loaded on the IPSec based FreeS/WAN program (Linux environment), and so the VPN problem mentioned above is resolved.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.605-610
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• 2009

Purpose: Substantial tissue necrosis after snake bites requiring coverage with flap surgery is extremely rare. In this article, we report 7 cases of soft tissue defects in the upper and the lower extremities caused by snake bites, which needed to be covered with flaps. Among the vast mass of publications on snake bites there has been no report that focuses on flap coverage of soft tissue defects due to snake bite sequelae. Methods: Seven cases of soft tissue defects with tendon, ligament, or bone exposure after snake bites were included. All patients were males without comorbidities, the average age was 35 years. All of them required coverage with a flap. In 6 cases, the defect was localized on the upper extremity, in one case the lesion was on the lower extremity. Local flaps were used in 6 cases, one case was covered with a free flap. The surgical procedures included one kite flap, one cross finger flap and digital nerve reconstruction with a sural nerve graft, one reverse proximal phalanx island flap, one groin flap, one adipofascial flap, one neurovascular island flap, and one anterolateral thigh free flap. The average interval from injury to flap surgery was 23.7 days. Results: All flaps survived without complication. All patients regained a good range of motion in the affected extremity. Donor site morbidities were not observed. The case with digital nerve reconstruction recovered a static two point discrimination of 7 mm. The patient with foot reconstruction can wear normal shoes without a debulking procedure. Conclusion: The majority of soft tissue affection after snake bites can be treated conservatively. Some severe cases, however, may require the coverage with flap surgery after radical debridement, especially, if there is exposure of tendon, bone or neurovascular structures. There is no doubt that definite coverage should be performed as soon as possible. But we also want to point out that this principle must not lead to a premature coverage. If the surgeon is not certain that the wound is free of necrotic tissue or remnants of venom, it is better to take enough time to get a proper wound before flap surgery in order to obtain a good functional and cosmetic result.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.173-181
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• 2011

Purpose : 2009 Pandemic influenza A (H1N1) virus was identified in March 2009 and subsequently caused worldwide outbreaks. We described the clinical and epidemiological characteristics of H1N1 influenza infection. Methods : We used retrospective medical chart reviews to collect data on the visiting patients from a single institute. H1N1 infection was confirmed in specimens with the use of a RT-PCR (real time reverse transcriptase polymerase chain reaction assay). Result : 6,836 patients had H1N1 RT-PCR test, and 2,781 were confirmed with H1N1 virus infection. 158 patients (5.7%) had hospital treatment and inpatients were significantly younger (5.4${\pm}$3.3 years) than outpatients (7.5${\pm}$3.9 years) among H1N1 virus confirmed patients. Oxygen, steroid, immunoglobulin, ventilator treatment was provided in a substantial proportion among pneumonia patients accompanying wheezy respiration. In addition more intensive care was needed in patients accompanying segmental, lobar, interstitial, mixed pneumonia and lung effusion (27.2%) than patients with bronchopneumonia (7.3%) among H1N1 virus infection confirmed patients. Seventy-one infants had oseltamivir treatment out of 83 infants under 1 year, and no significant side effects and complications were identified. Conclusion : In 2009 pandemic influenza A (H1N1), hospital treatment was needed in younger patients. Early intensive care was needed in pneumonia patients accompanying wheezy respiration, and patients accompanying segmental, lobar, interstitial, mixed pneumonia and lung effusion.

• Childhood Kidney Diseases
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• v.17 no.2
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• pp.79-85
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• 2013

Purpose: To test whether the expression of P-cadherin, a component of slit diaphragms between podocyte foot processes, would be altered by puromycin aminonucleoside (PAN) in a cultured podocyte in vitro. Methods: Rat glomerular epithelial cells (GEpC) were cultured with various concentrations of PAN. The distribution of P-cadherin was examined with a confocal microscope. Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) were used to measure the change in P-cadherin expression. Results: This study found that P-cadherin was concentrated in the inner and peripheral cytoplasm with high concentrations of PAN under immunofluorescence views. Western blotting of GEpC revealed that PAN induced a decrease of P-cadherin in dose- and time-dependent manners. A high dose ($50{\mu}g/mL$) of PAN decreased P-cadherin expression by 21.9% at 24 h (P <0.05) and 31.9% at 48 h (P <0.01) compared to those without PAN. In RT-PCR, high concentrations ($50{\mu}g/mL$) of PAN also decreased P-cadherin mRNA expression, similar to protein suppression, by 23.5% at 48 h (P <0.05). Conclusion: Podocytes exposed to PAN in vitro concentrated P-cadherin internally, and reduced P-cadherin mRNA and protein expression. This could explain the development of proteinuria in experimental PAN-induced nephropathy.

• Journal of fish pathology
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• v.31 no.1
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• pp.9-13
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• 2018

We previously monitored nervous necrosis virus (NNV) in brain samples of artificially produced walleye Pollock (Gadus chalcogrammus) seedlings, with a low prevalence (1.8%, 1/55) but no clinical symptoms. Given that this virus is considered one of the most serious viral threats for almost all marine aquaculture fish species and characterized by both vertical and horizontal transmission, it would be interesting to monitor NNV in the fertilized eggs as well. We collected fertilized walleye pollock eggs from the farms located in Goseong during January to March, 2017. Approximately 50 mg of eggs were periodically taken from 4 each different batches, and 37 different pooled sample sets in total were made during sampling period. RNA was extracted from the eggs by using Trizol and cDNA was synthesized for RT-PCR for detecting NNV. Primers and PCR conditions are the same as previously described. As a result, NNV was not detected from any of the sample sets by one step PCR (0%, 0/37), suggesting NNV may not be a threat in walleye pollock aquaculture in Korea at present time. However, continuous monitoring for NNV should be conducted because introducing a new species into aquaculture industry involves potentials of disease outbreak and NNV is already known to cause outbreaks in gadoid fishes.

• Resources Recycling
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• v.29 no.4
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• pp.3-14
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• 2020

Titanium sponge is industrially produced by the Kroll process. In order to understand the importance of the emerging smelting and recycling process, it is necessary to review the conventional production process of titanium. Therefore this paper provides a general overview of the conventional titanium manufacturing system mainly by the Kroll process. The Kroll process can be divided into four sub-processes as follows: (1) Chlorination of raw TiO₂ with coke, by the fluidized bed chlorination or molten salt chlorination (2) Magnesium reduction of TiCl₄ and vacuum distillation of MgCl₂ and Mg by reverse U-type or I-type with reduction-distillation integrated retorts (3) Electrolysis process of MgCl₂ by monopolar cells or multipolar cells to electrolyze into chlorine gas and Mg. (4) Crushing and melting process in which sponge titanium is crushed and then melted in a vacuum arc furnace or an electron beam furnace Although the apparatus and procedures have improved over the past 80 years, the Kroll process is the costly and time-consuming batch operation for the reduction of TiCl₄ and the separation of MgCl₂.