• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.106-112
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• 1999

The therapeutic potential of phosphodiesterase 4(PDE4) inhibitors in inflammatory diseases including some autoimmune diseases has been explored recently with some hopeful results. These PDE4 inhibitors are thought to show their anti-inflammatory effect by down-regulating tumor necrosis factor-a (TNF-$\alpha$) production in lymphocytes and macrophages. A high concentration of TNF-$\alpha$has been found in rheumatoid arthritis (RA) synovium and reducing TNF-$\alpha$using biological agents was proven to be an effective RA treatment. To test the possibility of using PDE4 inhibitors for RA treatment, the effects of a newly synthesized PDE4 inhibitor, DWP205505, on TNF-$\alpha$ and IL-10 production was tested in cells isolated from normal peripheral blood and rheumatoid arthritis synovial fluid. Cytokine production was assayed at the protein level by sandwich enzyme-linked immunosorbent assay (ELISA) and at the mRNA expression level by semi-quantitative RT-PCR. Another PDE4 inhibitor, RP73401, was used for comparison. DWP205505 and RP73401 had no harmful effect on cell viability up to 10 $\mu$M concentration during the 24 h culture period. DWP205505 as well as RP73401 significantly reduced TNF-$\alpha$ secretion from lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (pBMC) and synovial fluid mononuclear cells (SFMC). The effect of DWP205505 or RP73401 treatment on the mRNA expression of TNF-$\alpha$ was also studied in LPS-stimulated PBMC and SFMC. TNF-$\alpha$ mRNA expression was increased by LPS stimulation and both of the PDE4 inhibitors suppressed TNF-$\alpha$ mRNA expression. For interleukin-l0 (IL-l0), a little different results were obtained from PBMC and SFMC; IL-l0 secretion was unaffected by LPS stimulation and only minimally affected by both of the PDE4 inhibitors in PBMC. In unstimulated SFMC, DWP205505 and RP73401 slightly enhanced IL-10 secretion, while they reduced IL-l0 secretion from LPS-stimulated SFMC where IL-l0 secretion was a lot higher than unstimulated SFMC. These results suggest that the newly synthesized PDE4 inhibitor DWP205505 may have anti-rheumatoid arthritis activity.

• Development and Reproduction
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• v.12 no.3
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• pp.251-259
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• 2008

The plasticizer di(2-ethylhexyl)phthalate(DEHP) is one of the most well known endocrine disrupting chemicals (EDCs) because of its strong anti-androgenic effects on the reproductive and developmental process in male rodents and human. The present study was performed to examine whether prepubertal exposure to DEHP can make any alteration during the maturation of accessory sex organs in male rats. As a result, there was no significant change in body weights, serum T levels and tissue weights except of seminal vesicle and ventral prostate in DEHP-treated animals compared to vehicle-treated ones. The seminal vesicle weights in high-dose group (200 mg/kg) were significantly lower than those from the control group (p<0.05), and ventral prostate weights were significantly lower than those from the control group (p<0.05) in both low-dose (20 mg/kg) and high-dose group. Histological studies revealed that the seminal vesicles from DEHP-treated groups showed reduced areas of mucosal folds. Pseudostratified columnar epithelia were observed in the ventral prostates of DEHP-treated samples while cuboidal epithelia were found in the control group. The transcriptional activities of ER-$\alpha$ in seminal vesicle from high-dose group (p<0.05) were significantly higher than those from the control group, and ER-$\beta$ expression was significantly decreased in low-dose group (p<0.05) compared to the control. In ventral prostate, ER-$\beta$ mRNA levels from low-dose group (p<0.05) were significantly lower than those from the control group, and significantly increased in high-dose group (p<0.01). AR expressions, however, were not significantly different in all experimental groups of both seminal vesicle and ventral prostate. In conclusion, the present study demonstrated that (i) adverse effect (s) of DEHP on sexual maturation during prepubertal period could be limited, (ii) seminal vesicle and prostate gland were sensitive targets to DEHP in prepubertal rats and (iii) the deleterious effects of DEHP might be mediated through ER-associated mechanism.

• Korean journal of applied entomology
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• v.61 no.3
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• pp.423-434
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• 2022

The two previously developed artificial diets (N4 and N6) used for rearing Spodoptera frugiperda (Noctuidae) larvae, were selected as highly-fit ones for rearing Mythimna loreyi larvae. Almost all biological characteristics were not significantly different between the colonies reared on the two diets at 25℃ and 15:9 h (light:dark) photoperiod. The developmental periods were 4.9-5.2 days for eggs, and 22.3-23.2 days for larvae. The pupal period and weight were different between the sexes in each diet colony. The pupal periods in females and males showed 12.6-12.8 days and 14.1-14.5 days, respectively. The pupal weights were ca. 345 mg for females and ca. 380 mg for males. The pupation and emergence rates were ca. 91-94%, and ca. 91-95%, respectively, without significant differences between the two colonies. The pre-oviposition and oviposition periods were 3.4 days and 4.7-4.8 days, respectively. The adult longevity was 8.2 days in females and 10.3-12.4 days in males. Total offsprings produced were found to be 724-847 larvae on an average with ca. 1,400 maximum larvae. In the life table analysis, the intrinsic rates of increases (0.1181 for N4 and 0.1253 for N6) were not significantly different between the two colonies. Individual differences in the larval instar number 5 and 6 were found within a diet colony. The ratios of 5-instar larvae were ca. 22% in N4 colony and ca. 7% in N6 colony. The larval period of 6-instar larvae was longer than that of 5-instar larvae. Width of head capsule in larvae varied from ca. 309 ㎛ for 1st instar to ca. 3,065 ㎛ for 6th instar. Body lengths measured from ca. 2.0 mm for 1st instar to ca. 29.1 mm for 6th instar. Larvae of M. loreyi and M. separata were found at the same time in a maize field during June and July, 2020.

• Journal of Life Science
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• v.33 no.9
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• pp.713-723
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• 2023

Lung cancer is a type of cancer that has the highest mortality rate. It is mainly classified into small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC). Chemotherapy is used to treat lung cancer, but long-term treatment causes side effects and drug resistances. Curcumin is a bright yellow polyphenol extracted from the root of turmeric. It has biological activities, such as anti-oxidant, anti-cancer, and anti-inflammatory effects. In this study, we observed differential cell death in human lung cancer cells. Based on the results, curcumin at 10, 30, and 50 μM exhibited a dose-dependent inhibition on the cell survival of several lung cancer cells, with minor differential phenotypes. In addition, apoptosis, autophagy, and reactive oxygen species (ROS) regeneration were observed through flow cytometry. Curcumin dose-dependently increased these phenotypes in A549 (NSCLC) and DMS53 (SCLC), which were restored by corresponding inhibitors. Western blotting was performed to measure the level of expression of apoptosis- and autophagy-related proteins. The results indicate that Bax, PARP, pro-caspase-3, and Bcl-2 were dose-dependently regulated by curcumin, with seemingly higher Bax/Bcl-2 ratios in DMS53. In addition, autophagic proteins, p-AKT, p62, and LC3B, were dose-dependently regulated by curcumin. ROS inhibition by diphenyleneiodonium reduced the induction of apoptosis and autophagy generated by curcumin. Taken together, it is suggested that curcumin induces apoptosis and autophagy via ROS generation, leading to cell death, with minor differences between human lung cancer cells.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.179-191
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• 2023

The purpose of this study was to investigate the prevalence and patterns of congenitally missing teeth in permanent teeth excluding third molars, in patients aged 8 to 16 years who visited Pusan National University Dental Hospital from January 2010 to February 2021. This retrospective study evaluated tooth agenesis and the pattern of missing teeth represented by the tooth agenesis code by reviewing panoramic radiographs and electronic medical records of 11,759 patients, including 5,548 females and 6,211 males. The prevalence of congenitally missing teeth was 10.74% (females 11.95%, males 9.66%, p < 0.0001). Patients with tooth agenesis had an average of 2.22 missing teeth, and congenitally missing teeth occurred more frequently in the mandible (8.39%) than in the maxilla (4.52%, p < 0.0001). The mandibular second premolar (58.19%) was the most frequently missing tooth. The second premolar was the most frequently missing tooth in all quadrants (30.10%, 31.67%, 43.14%, and 35.59%) when a single tooth was absent, while the first and second premolars were the most commonly absent teeth (11.69%, 11.47%, 5.94%, and 5.24%) when two or more teeth were missing. In the relationship between maxillary-mandibular antagonistic quadrants and full mouth, the 1st to 4th place of the missing patterns were all involved with the 1st and 2nd premolars. This study can be clinically helpful in establishing a treatment plan for patients with missing teeth. In addition, it can be used as basic data for molecular biological research to find out the relationship between tooth agenesis and specific genes.

• Korean Journal of Ecology and Environment
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• v.56 no.1
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• pp.94-103
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• 2023

Cyanobacterial resting cells, such as akinetes, are important seed cells for cyanobacteria's early development and bloom. Due to their importance, various methods have been attempted to isolate resting cells present in the sediment. Ludox is a solution mainly used for cell separation in marine sediments, but finding an accurate method for use in freshwater is difficult. This study compared the two most commonly used Ludox methods (direct sediment treatment and sediment distilled water suspension treatment). Furthermore, we proposed a highly efficient method for isolating cyanobacterial resting cells and eDNA amplification from freshwater sediments. Most of the resting cells found in the sediment were akinete to the Nostocale and were similar to those of Dolichospermum, Cylindrospermum, and Aphanizomenon. Twenty times more akinetes were found in the conical tube column using the sediment that had no treatment than in the sample treated by suspending the sediment in distilled water. Akinete separated through Ludox were mainly spread over the upper and lower layers in the column rather than concentrated at a specific depth in the column layer. The mibC, Geo, and 16S rDNA genes were successfully amplified using the sediment directly in the sample. However, the amplification products of all genes were not found in the sample in which the sediment was suspended in distilled water. Therefore, 5 g to 10 g of sediment is used without pretreatment when isolating cyanobacterial resting cells from freshwater sediment. Cell isolation and gene amplification efficiency are high when four times the volume of Ludox is added. The Ludox treatment method presented in this study isolates cyanobacterial resting cells in freshwater sediment, and the same efficiency may not appear in other biotas. Therefore, to apply Ludox to the separation of other biotas, it is necessary to conduct a pre-experiment to determine the sediment pretreatment method and the water layer where the target organism exists.

• Korean Journal of Ecology and Environment
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• v.56 no.1
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• pp.57-69
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• 2023

The objectives of this study were to analyze the fish community structures and distribution characteristics of fisheries resources in the Osip Stream and Wangpi Stream, fishery resources protection areas. For the study, we conducted fish samplings four times in the two streams from April to October 2019. In Osip Stream and Wangpi Stream, we sampled 31 species and 29 species and the dominant species were Zacco platypus (28.6%) and Squalidus multimaculatus(41.7%), respectively. According to the life type of fish species, primary freshwater species were collected 18 species(58.1%) and 21 species(72.4%), and migration fishes were sampled 4 species (12.9%) and 6 species (20.7%) in Osip Stream and Wangpi Stream, respectively. Fisheries resources species showed high relative abundance in June, and the fish biomass was highest in October. As a results of comparing the previous studies with this study, both rivers showed high biodiversity and were found to maintain stable populations of fishes. According to analysis of tolerance guilds, the proportion of tolerant species, based on the number of individuals, was composed of 14.4% and 1.1% in Osip Stream and Wangpi Stream, respectively. This very low ratio of tolerant species confirmed that both streams have very good physiochemical environment conditions. From the above results, it was judged that the fishery resource protection areas of Osip Stream and Wangpi Stream have high ecological function and preservation value. For sustainable use and management of fishery resource protection areas of Osip Stream and Wangpi Stream, it is suggested that biological disturbance management, fish discharge projects considering environmental capacity, efforts to improve the habitat environment, and establishing a fishery resource protection areas management system were necessary as considerations.

• Economic and Environmental Geology
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• v.55 no.6
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• pp.727-736
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• 2022

Ice wedges are subsurface ice mass structures that formed mainly by freezing precipitation with airborne dust and surrounding soil particles flowed through the active layer into the cracks growing by repeating thermal contractions in the deeper permafrost layer over time. These ice masses characteristically contain high concentrations of solutes and solids. Because of their unique properties and distribution, the possibility of harnessing ice wedges as an alternative archive for reconstructing paleoclimate and paleoenvironment has been recently suggested despite limited studies. It is imperative to preserve the physicochemical properties of the ice wedge (e.g., solute concentration, mineral particles) without any potential alteration to use it as a proxy for reconstructing the paleo-information. Thawing the ice wedge samples is prerequisite for the assessment of their physicochemical properties, during which the paleo-information could be unintentionally altered by any methodological artifact. This study examined the effect of thawing conditions and procedures on the physicochemical properties of solutes and solid particles in ice wedge samples collected from Cyuie, East Siberia. Four different thawing conditions with varying temperatures (4 and 23℃) and oxygen exposures (oxic and anoxic) for the ice wedge sample treatment were examined. Ice wedge samples thawed at 4℃ under anoxic conditions, wherein biological activity and oxidation were kept to a minimum, were set as the standard thawing conditions to which the effects of temperature and oxygen were compared. The results indicate that temperature and oxygen exposure have negligible effects on the physicochemical characteristics of the solid particles. However, the chemical features of the solution (e.g., pH, electric conductivity, alkalinity, and concentration of major cations and trace elements) at 4℃ under oxic conditions were considerably altered, compared to those measured under the standard thawing conditions. This study shows that the thawing condition of ice wedge samples can affect their chemical features and thereby the geochemical information therein for the reconstruction of the paleoclimate and/or paleoenvironment.

• Clean Technology
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• v.29 no.1
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• pp.31-38
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• 2023

Due to water shortages caused by water pollution and climate change, total organic carbon (TOC) standards have been implemented for wastewater discharged from public sewage treatment facilities. Furthermore, there is a growing interest and body of research pertaining to the reuse of sewage treatment water as a secure alternative water resource. The membrane bio-reactor (MBR) method is commonly used for advanced wastewater treatment because it can remove organic and inorganic ions and it does not require or emit any chemicals. However, the MBR process uses a separation membrane (MF), which requires frequent film cleaning due to fouling caused by a high concentration of mixed liquor suspended solid (MLSS). In this study, process improvement and microbubble cleaning efficiency were evaluated to improve the differential pressure, water flow, and MF fouling, which are the biggest disadvantages of operating the MF. The existing MBR method was improved by installing a precipitation tank between the air tank and the MBR tank in which raw water was introduced. Microbubbles were injected into a separation membrane tank into which the supernatant water from the precipitation tank was introduced. The microbubble generator was operated with a 15 day on, 15 day off cycle for 5 months to collect discharged water samples (4L) and measure TOC. As the supernatant water from the precipitation tank flowed into the separation membrane tank, about 95% of the supernatant water MLSS was removed so the MF fouling from biological contamination was prevented. Due to the application of microbubbles to supernatant water from the precipitation tank, the differential pressure of the separation membrane tank decreased by 1.6 to 2.3 times and the water flow increased by 1.4 times. Applying microbubbles increased the TOC removal rate by more than 58%. This study showed that separately operating the air tank and the separation membrane tank can reduce fouling, and suggested that applying additional microbubbles could improve the differential pressure, water flow, and fouling to provide a more efficient advanced treatment method.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.2
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• pp.101-112
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• 2023

Purpose. This retrospective study was to investigate the survival and complication rates of posterior single implant according to the implant diameters, lengths and position. Materials and methods. Patients who had been restored single implant prosthesis in the posterior area by the three prosthodontists in the department of prosthodontics, Daejeon dental hospital of Wonkwang university, in the period from February 2014 to May 2018 were selected for the study. A total of 505 patients with 697 implants were observed. The survival and complications of implants were investigated using electronic medical records and radiographs. Fixture diameters, lengths, position, patient's sex and age were assessed as possible factor affecting the survival and complications of implants. Results. 3-year cumulative survival rates of posterior single implants were 98.5% and 5-year cumulative survival rates were 94.4%. 5-year cumulative survival rates were higher in implants with diameter > 4.0 mm (97.0%) than implants with diameter ≤ 4.0 mm (89.5%), and in females (98.8%) than males (92.4%). There were statistically significant differences (P < .05). The mechanical complication rate was 20.1% and the biological complication rate was 4.7%. Complications occurred in order of abutment screw loosening (7.5%), decementation (6.3%), proximal contact loss (3.7%) and so on. Abutment screw loosening occurred more frequently in the lower molar region (10.5%), in males (9.5%) than females (5.1%), and in patients aged < 65 years (9.4%) than patients aged ≥ 65 years (5.1%). There were statistically significant differences (P < .05). Conclusion. The 5-year cumulative survival rates were higher in implants with diameter > 4.0 mm than implants with diameter ≤ 4.0 mm and in females than males. Abutment screw loosening which was the most commonly occurring complication occurred more frequently in the lower molar region, in males than females, and in patients aged < 65 years than patients aged ≥ 65 years. There were statistically significant differences.