• Biomolecules & Therapeutics
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• v.30 no.2
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• pp.203-211
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• 2022

Melanogenesis is the production of melanin from tyrosine by a series of enzyme-catalyzed reactions, in which tyrosinase and DOPA oxidase play key roles. The melanin content in the skin determines skin pigmentation. Abnormalities in skin pigmentation lead to various skin pigmentation disorders. Recent research has shown that the expression of EMP2 is much lower in melanoma than in normal melanocytes, but its role in melanogenesis has not yet been elucidated. Therefore, we investigated the role of EMP2 in the melanogenesis of MNT1 human melanoma cells. We examined TRP-1, TRP-2, and TYR expression levels during melanogenesis in MNT1 melanoma cells by gene silencing of EMP2. Western blot and RT-PCR results confirmed that the expression levels of TYR and TRP-2 were decreased when EMP2 expression was knocked down by EMP2 siRNA in MNT1 cells, and these changes were reversed when EMP2 was overexpressed. We verified the EMP2 gene was knocked out of the cell line (EMP2 CRISPR/Cas9) by using a CRISPR/Cas9 system and found that the expression levels of TRP-2 and TYR were significantly lower in the EMP2 CRISPR/Cas9 cell lines. Loss of EMP2 also reduced migration and invasion of MNT1 melanoma cells. In addition, the melanosome transfer from the melanocytes to keratinocytes in the EMP2 KO cells cocultured with keratinocytes was reduced compared to the cells in the control coculture group. In conclusion, these results suggest that EMP2 is involved in melanogenesis via the regulation of TRP-2 expression.

• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.1-9
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• 2022

An estuary is an area where a freshwater river or stream meets the ocean. Even before the importance of the value of estuaries was recognized, the estuary was lost because of large-scale conversion by draining, filling, damming, and dredging. In South Korea, 643 estuaries are located, and the total area is 3,248,300 ha, accounting for 32.5% of the total area of South Korea. Over 35% of Korean estuaries are closed estuaries which are only temporally connected with the sea, either permanently or periodically. Since 2008, in order to preserve the estuary ecosystem and solve major issues in the estuary by accumulating knowledge about the estuarine ecosystem, the Ministry of Environment of Republic of Korea has been conducting the "Estuarine Ecosystem Monitoring and Assessment Project". At 668 sites of 325 estuaries, epilithic diatom, benthic macroinvertebrate, fish, and vegetation are investigated, and the habitat condition of each site is evaluated using the newly developed biotic index. More than 100 researchers annually record 2,097 species of estuaries according to the standardized survey guidelines over the past 14 years and provide strictly managed data necessary for establishing estuaries conservation policies. As a result of bibliometric analysis of 1,195 research articles related to the monitoring and assessment of the estuarine ecosystem, research on pollutants such as heavy metals and sediment control have recently been conducted. "Estuarine Ecosystem Monitoring and Assessment Project" is an ecological monitoring type of long-term mandated monitoring that is usually focused on identifying trends. Although it is difficult to identify the mechanism influencing a change in an ecosystem through long-term mandated monitoring, providing empirical data for supporting evidence-based policy, decision-making, and the management of ecosystems. In order to increase the efficiency of the project, research to investigate the relationship between sediments and pollutants and organisms can be conducted at specific estuaries or sites to compensate for the shortcomings of mandatory monitoring.

• Journal of the Korean Orthopaedic Association
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• v.54 no.6
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• pp.528-536
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• 2019

Purpose: This study examined the effects of a weekly teriparatide on the change in vertebral compression ratio, back pain, and vertebral fracture healing in osteoporosis patients with vertebral compression fractured induced by low energy trauma. Materials and Methods: From January 2016 to December 2017, 57 patients with severe osteoporotic vertebral fractures with a T score of -3.5 or less were included in this study. The changes in the vertebral compression ratio, visual analogue scale (VAS), Oswestry disability index (ODI) for at least 6 months were examined. The morphology of bone marrow edema and the presence of intervertebral cleft, osteocalcin, and N-terminal telopeptide (NTx) were also investigated. Results: The mean compression ratio was 20% in the experimental group (teripratide group) at 3 months, and 38% in the control group. A significant difference in the compression ratio of the vertebral body over time was observed (p<0.05; t-test). A comparison of the compression ratio of the vertebral body with the follow-up duration in each group showed no significant increase in the, compression (p=0.063) in the experimental group and a significant increase in the control group (p<0.05). The mean time to reach the plateau of the compression rate was one month in the experimental group and three months in the control group. The VAS score in the experimental and control group was 0.39 and 1.07 points, respectively. The ODI score in the experimental and control group was 33.72 and 39.52, respectively. At the last follow-up radiographs, there were no cases with an intervertebral cleft (0%) in the experimental group and 1 case (2.2%) in the control group. A significant difference in the osteocalcin level was observed between the injury and 6 months after the injury (p=0.003). In addition, there was no significant difference in the NTx level between the injury and 6 months after injury (p=0.960). Conclusion: In vertebral compression fractures patients with severe osteoporosis, a weekly teriparatide can promote the union of fractures, prevent further collapse of the vertebral body, and reduce the back pain faster.

• Journal of the Korean Orthopaedic Association
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• v.54 no.5
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• pp.411-417
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• 2019

Purpose: To compare the clinical outcomes of single injection adductor canal block (SACB), continuous adductor canal block (CACB), and the concomitant use of transdermal buprenorphine after total knee arthroplasty (TKA). Materials and Methods: A total of 125 patients who underwent TKA were divided into three groups and the clinical results were retrospecitively compared. Group I was comprised of patients with pain controlled by SACB (n=41). Group II consisted of patients with pain controlled by both SACB and transdermal buprenorphine (10 ㎍/h) (n=44). Group III contained patients with pain controlled by CACB (n=40). The visual analogue scale (VAS) was used as the pain control indicator and the patients were measured on a VAS for resting on the bed (VAS-Rest) at 12 hours, 24 hours, and 48 hours after surgery. The VAS while doing continuous passive motion (VAS-CPM) on the first and second postoperative day was also measured. In addition, the total amount of medications used (Butopahn, Tridol, and Ketorac) for the intravenous patient controlled analgesia (PCA) was counted for 48 hours after surgery. As the indicator of the functional recovery outcome, the incidence of nausea and vomiting was observed for 48 hours after surgery. The maximum knee joint flexion range and maximum walking distance on the first and second postoperative day, and the total length of stay at the hospital were compared. Results: The VAS-Rest was similar in the three groups at 12 hours after surgery, but at 24 hours and 48 hours after surgery, group II and III a lower VAS-CPM and total amount of medications used for PCA than group I (p<0.05). The three groups showed a low incidence of nausea and vomiting, maximum knee joint flexion range, and similar walking distance and total length of stay at the hospital. Conclusion: The combination of SACB and transdermal buprenorphine has great pain control effect initially. On the other hand, it is not associated with catheter complications and it is convenient to use and safety toward the renal function. Therefore, the concomitant use of SACB and transdermal buprenorphine can be an effective pain control method after TKA.

• Journal of the Korean Orthopaedic Association
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• v.54 no.5
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• pp.435-439
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• 2019

Purpose: This study evaluated the efficacy of blood mixed cement for osteoporotic vertebral compression fractures in reducing the complications of percutaneous vertebroplasty using conventional cement. Materials and Methods: This study was performed retrospectively in 80 patients, from January 2016 to January 2017. Porous cement was formed by mixing 2, 4, and 6 ml of blood with 20 g of cement used previously. A tube with a diameter and length of 2.8 mm and 215 mm, respectively, was used and the polymerization temperature, setting time, and optimal passing-time were measured and compared with those using only conventional cement. Radiologically, the results were evaluated and compared. Results: The polymerization temperature was 70.3℃, 55.3℃, 52.7℃, and 45.5℃ in the conventional cement (R), 2 ml (B2), 4 ml (B4), and 6 ml (B6), respectively, and the corresponding setting time decreased from 960 seconds (R) to 558 seconds (B2), 533 seconds (B4), and 500 seconds (B6). The optimal passing-time was 45 seconds (B2), 60 seconds (B4), and 78 seconds (B6) at 73 seconds (R), respectively and as the amount of blood increased, it was similar to the cement passing-time. The radiological results showed that the height restoration rates and the vertebral subsidence rates similar among the groups. Two cases of adjacent vertebral compression fractures in the R group and one in the B2 and B4 groups were encountered, and the leakage rate of the cement was approximately two times higher than that in the conventional cement group. Conclusion: In conventional percutaneous vertebroplasty, the procedure of using autologous blood with cement decreased the polymerization temperature, reduced the setting time, and the incidence of cement leakage was low. These properties may contribute to more favorable mechanical properties that can reduce the complications compared to conventional cements alone.

• Laboratory Medicine Online
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• v.1 no.2
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• pp.100-104
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• 2011

Background: Malaria is a problematic disease in Korea, and microscopic examination of Giemsa-stained blood smear has been used as the gold standard for its diagnosis. However, this technique is time-consuming and has low sensitivity in samples with low numbers of malarial parasites (<20 parasites/μL). Here, we evaluated the performance characteristics of the LG Advansure^TM Malaria P.f./P.v. real-time QPCR (LG life sciences, Korea). Methods: Blood samples from 173 persons who visited Korea University Ansan Hospital were evaluated. QPCR was performed in 73 malaria patients and 100 healthy subjects by using the LG Advansure Malaria P.f./P.v. real-time QPCR^R kit, and the results were compared with those of microscopy. The detection limit of this kit was determined by serial dilution of Plasmodium-infected blood with normal blood (blood not infected with Plasmodium). Results: Among the 73 patients that were microscopically confirmed to have malaria (Plasmodium vivax infection, N=70, P. falciparum infection, N=3), 69 patients were diagnosed with P. vivax infection and 3 were diagnosed with P. falciparum infection by LG Advansure^TM Malaria P.f./P.v. realtime QPCR. Both the tests indicated absence of infection in the 100 healthy subjects. The detection limit of LG Advansure^TM Malaria P.f./P.v. real-time QPCR was 0.1 parasite/μL. Conclusions: LG Advansure^TM Malaria P.f./P.v. real-time QPCRis a very sensitive and specific technique and can be used as a confirmatory test for malaria.

• Laboratory Medicine Online
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• v.1 no.1
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• pp.57-63
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• 2011

Background: ABO antibody titration is useful for the evaluation of ABO-incompatible bone marrow or solid organ transplantations, yet the results quite vary between different test methods used. We compared the results of microcolumn agglutination and tube methods. Methods: Anti-A and anti-B isoagglutionin titers were determined in 63 healthy individuals (23 O, 20 A, and 20 B blood groups) using 4 different methods: immediate spin tube (tube), microcolumn agglutination without anti-human globulin (AHG) (CAT), tube with AHG (tube-AHG) and microcolumn agglutination with AHG (CAT-AHG). Results: The median (range) titers of anti-A and anti-B in group O individuals by tube, CAT, tube-AHG, and CAT-AHG methods were 64 (8-512), 64 (8-512), 128 (8-2,048), and 128 (16-2,048); 64 (16-128), 128 (16-256), 128 (16-512), and 256 (16-512), respectively. The median (range) titers of anti-A in group B and anti-B in group A individuals by the four methods were 64 (16-128), 128 (8-128), 128 (8-256), and 256 (8-256); 64 (8-128), 64 (8-128), 32 (8-128), and 64 (8-256), respectively. The isoagglutinin titer measured by CAT-AHGmethod was the highest. The titers measured by CAT and CAT-AHG methods were 0-1 titer higher than those by tube and tube-AHG methods, respectively. Whatever method was used, the isoagglutinin titers were higher in women than in men. Conclusions: CAT-AHG was the most sensitive method among the four methods tested. Since AHG titer values are critical for the clinical management and CAT has less manual procedures than tube method, CAT-AHG method could be used for the standardization of ABO antibody titration in different institutions.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.125-138
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• 2016

To assess the industrial possibility of mixed-extracts containing Hovenia dulcis Thunberg and 12 different botanical ingredients, a protective effect was confirmed in the chronic ethanol-induced the liver, brain, and blood injury in mouse. Blood glucose levels of the normal control group(NG) and ethanol administration group(EG) were respectively 119.43mg/dL and 305.25mg/dL, and the mixed-extracts administration group(100, 200mg/kg body weight + 25% ethanol 5g/kg body weight respectively; ME100 & ME200) were decreased to 272.76mg/dL and 234.60mg/dL. Blood ethanol contents were decreased in ME100 and ME200(3.85mg/dL, 3.08mg/dL) compared to EG(4.08mg/dL), and blood acetaldehyde contents were also decreased in ME(15.76mg/dL, 15.16mg/dL) compared to EG(18.72mg/dL). The contents of hepatotoxic indicators such as glutamine pyruvic transaminase(GPT) and glutamic oxaloacetic transaminase (GOT), nephrotoxic indicators such as blood urea nitrogen(BUN), and creatine(CRE), and total cholestero(TCHO), and triglyceride(TG) in mouse blood serum were significantly decreased in the ME compared to EG. The acetylcholinesterase(AChE) activity of ME(109.00% and 108.47%, respectively) in mouse brain tissues was decreased in ME compared to EG(116.10%). Finally, ME was remarkable in vivo antioxidant activities in the mouse liver and brain tissues by superoxide dismutase(SOD), oxidized glutathione(GSH)/total GSH ratio and the malondialdehyde (MDA) assay. Therefore, the mixed-extracts was considered to be effective a high value food with protective effect against chronic ethanol traetment-induced cytotoxicity in liver and brain tissues.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.105-115
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• 2016

This study was carried out to establish the optimum forest management plan for the Cryptomeria japonica plantations in southern inland and Jeju island in Korea. Sixty seven circular sample plots of 0.04ha were established and we surveyed vegetation structure and growth characteristics from three layers(upper, middle, and lower). As a result of cluster analysis obtained by importance values of each tree species, the community type of C. japonica stands were classified into C. japonica group(C1) and C. japonica-C obtusa group. C. obtusa community were also sbudivided into P. thunbergii-Q. serrata group(C2) and Q. serrata-C obtusa group(C3). In tree layers importance value(IV) of C. japonica were 97.2% in C1, 80.7% in C2, and 47.6% in C3 and in sub-tree layers IV were 8.9% in C1, 15.2% in C2, and 5.7% in C3. Especially in C3 there are bamboo species (Smilacina japonica var. lutecarpa and Pseudosasa japonica) it is necessary for us to control them. In shrub layers C. japonica were found in C1(9.2%) and C2(7.0%), but except for C3. In tree layer species diversity indices of each community ranged from the lowest 0.059 in C1 to the highest 0.548 in C3. Dominance ranged from 0.958 in C1 to 0.393 in C3 which may caused by interspecific competition. Current annual increment of diameter growth ranged from 7.01mm/yr to 8.04mm/yr. As a result of our study we recommend the application of proper thinning and pruning for C1 and C2.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.4
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• pp.327-351
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• 2009

Laboratory tests are performed in this paper to investigate the brittle failure characteristics of over-stressed rocks taken in deep depth. Also, numerical simulation performed using that the so-called CWFS(Cohesion Weakening Frictional Strengthening) model is known to predict brittle failure phenomenon reasonably well. The most typical rock types of Korean peninsula - granite and gneiss - were used for testing. Results of uniaxial compression tests showed that the crack initiation stress was about 41 % to 42% of the uniaxial compressive strength regardless of rock types, where as, the crack damage stress of granite was about 75%, and that of gneiss was about 97%. Through the damage-controlled test, strength parameters of each rock were obtained as a function of damage degree. After the peak, the crack damage stress and the maximum stress were decreased, The cohesion was decreased and the friction angle was increased with increase of rock damage. Before reaching the peak, the elastic modulus was slightly increased, while decreased after the peak. Poisson's ratio was increased as the damage of rock proceeds. Comparison of uniaxial compression tests and damage-controlled tests shows the crack initiation stress estimated from the damage-controlled test fluctuated within the range of crack initiation stress obtained from the uniaxial compression test; the crack damage stress was less than that estimated from the uniaxial compression test. In order to predict the critical depth that brittle failure occurs, numerical simulations using the CWFS model were performed for an example site. Material parameters obtained from the laboratory tests mentioned above were used for CWFS simulation. Comparison between the critical depth predicted from the numerical simulation using the CWFS model and that predicted by using the damage index proposed by Martin et al.(l999), showed that critical depth cannot be reasonably predicted by the currently used damage index except for circular tunnels. A modified damage index was proposed by the author which takes the shape of tunnels other than circular into account.