• Journal of Microbiology and Biotechnology
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• v.34 no.9
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• pp.1898-1911
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• 2024

Phylloporia lonicerae is an annual fungus that specifically parasitizes living Lonicera plants, offering significant potential for developing new resource food and medicine. However, wild resources and mycelium production of this fungus is limited, and its anti-tumor active ingredients and mechanisms remain unclear, hampering the development of this fungus. Thus, we optimized the fermentation medium of P. lonicerae and studied the anti-tumor activity of its mycelium. The results indicated that the optimum fermentation medium consisted of 2% sucrose, 0.2% peptone, 0.1% KH₂PO₄, 0.05% MgSO₄·7H₂O, 0.16% Lonicera japonica petals, 0.18% P fungal elicitor, and 0.21% L. japonica stem. The biomass reached 7.82 ± 0.41 g/l after 15 days of cultivation in the optimized medium, a 142% increase compared with the potato dextrose broth medium, with a 64% reduction in cultivation time. The intracellular alcohol extract had a higher inhibitory effect on A549 and Eca-109 cells than the intracellular water extract, with half-maximal inhibitory concentration values of 2.42 and 2.92 mg/ml, respectively. Graded extraction of the alcohol extract yielded petroleum ether phase, chloroform phase, ethyl acetate phase, and n-butanol phase. Among them, the petroleum ether phase exhibited a better effect than the positive control, with a half-maximal inhibitory concentration of 113.3 ㎍/ml. Flow cytometry analysis indicated that petroleum ether components could induce apoptosis of Eca-109 cells, suggesting that this extracted component can be utilized as an anticancer agent in functional foods. This study offers valuable technical support and a theoretical foundation for promoting the comprehensive development and efficient utilization of P. lonicerae.

• Journal of Aerospace System Engineering
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• v.18 no.5
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• pp.51-60
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• 2024

Variation in rotor angle of a tiltrotor aircraft can significantly impact aerodynamic characteristics of the aircraft. This study utilized Computational Fluid Dynamics (CFD) to analyze aerodynamic performance of a tiltrotor drone with varying flight speeds and rotor angles. The Multiple Reference Frame (MRF) method was applied to simulate the flow generated by the propeller. Trends in lift and drag of the drone across flight modes were analyzed. Degradation in aerodynamic performance under specific flight conditions was examined in terms of changes in effective angle of attack. Results showed that the more negative the effective angle of attack on the propeller, the greater the degradation in aerodynamic performance. Since the effective attack angle of the propeller changes with rotor angle and flight speed, it is necessary to adjust the propeller's RPM and collective pitch to control the effective attack angle.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.158-164
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• 2007

Uterine leiomyoma is the most common tumor in the female genital tract. Although the tumor is benign, it is a matter of paramount importance since it often causes profuse menstrual bleeding, pressure symptoms and infertility. Nevertheless, the etiology and pathophysiology of this abnormality remain poorly understood. The traditional definitive treatment for uterine leiomyomas is hysterectomy and, even today, symptomatic leiomyomas are the leading cause of hysterectomy in Korea. Clearly, the development of a safe, effective, and nonsurgical method of treatment for leiomyoma would be of great benefit to many women. This study demonstrated growth inhibition of uterine leiomyoma cells using Haeohyultang (HT). When human leiomyoma cells were treated with Haeohyultang, cells showed dose-dependent growth inhibitory effect. Cell growth was inhibited by over 40% as determined by both cell counts and MTS assay. Reduction of cellular viability as a consequence of exposure to Haeohyultang resulted from induction of apoptosis, as assessed by DNA fragmentation, PARP cleavage, caspase 9 and caspase 3 assay. Flow cytometry analysis with uterine leiomyoma cells demonstrated sub G1 cell cycle arrest after treatment with drug Haeohyultang. But, the expression levels of p27 and p21 were not changed in Haeohyultang treated cells compared with control. However, the expression levels of clAP1 were reduced by Haeohyultang compared with control. This reduction of clAP1 data means activation of the caspase family, and then induction of PARP cleavage and apoptosis. These results suggest that Haeohyultang may be potential therapeutic approach in the clinical management of uterine leiomyoma.

• Economic and Environmental Geology
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• v.4 no.1
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• pp.11-18
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• 1971

The geotectonics and geomorphic structure of Korea resulted from the Song-rim Disturbance and the Daebo orogenic movements. Afterward this mountainous peninsula underwent several geological changes on a small scale, and it was also claimed that the steady rising of the elevated peneplain of the eastern coast and the submerging of the southwestern coastal area are largely due to the tilted block movement. These views have been generally accepted good in several ways, but they are limited in range or lacking in theoretical integration. The present writer investigated the geology of the Mt. Chi-ri-san and the Honam coal mining area for a geological map in 1965, respectively. The results of these studies convinced the present writer that the conventional views, which were based upon a theory of lateral pressure should be reconsidered in many respects, and more recent studies made it clear that the morphological development in the southwestern area can be better explained by the orogenic movement and rock control. The measurement of submerging speed of the western coastal area (Pak. Y. A., 1969) and a new account on the geology and tectonics of the Mid-central region of South Korea (Kim O.J., 1970) act as an encouragement to a new explanation. The present writer's researches on the extreme southwestern portion of the peninsula show that the steady submerging of this area cannot be attributed to a simple downthrown block phenomenon caused by block movement. It is no more than the result of the differential movement of uplifting in the eastern and western coastal areas and the rising of sea-level in the post-glacial period. This phenomenon could be easily explained by the comparison of the rate of rise in sea-level and amount of heat flow between Korea and other areas in the world. The existance of the erosional planes in the Sobaik-San ranges also provide an evidence of an upheaval in the western coast area. Though the Sobaik-San ranges largely follow the direction of the Sinian system. They consist of the numerous branches, whose trends run more or less differently from their main trend because of the disharmonic folding, are converged into Mt. Sobaik-San and Chupungryung. The undulation of the land is not wholely caused by orogenic movements, where as the present writer confirmed that the diversity of morphological development is the direct reflection of geological conditions such as rocks and processes which constitute the basic elements of geomorphic structure. An east-west directed mountain range which could be named as Hansan mountain range, was claimed to be oriented by the joint control. The geological conditions such as a special erosion and weathering of agglomerate and breccia tuff usually produce pot-hole like submarine features which cause the whirling phenomenon at the southwestern coast channel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.86-98
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• 2014

This study examined a long-standing issue with its perverse results in the Korean capital markets, such as any variant financial profiles over time, affecting capital structure for the firms belonging to the chaebols. It may be of interest to identify these components from the perspectives of international investors and domestic policy makers to implement their contingent strategies on the target leverage, since the U.S. financial turmoils in the late 2000s. Regarding the evidence from the three hypothesis tests on the firms in the chaebols, this research found that the control variabels measuring profitability, business risk, and non-debt tax shields, showed their statistically significant relationships with the different types of a debt ratio. While FCFF(free cash flow to the firm) showed its significant influence to discriminate between the firms in the chaebols and their counterparts, not belonging to the chaebols, BDRELY as the ratio of liabilities to total assets, comprising the enhanced 'Dupont' system, only showed its statistically significant effect on leverage in the context of the parametric and nonparametric tests. In line with the results obtained from the present research, one may expect that a firm in the Korean chaebol, may control or restructure its present level of capital structure to revert to its target optimal capital structure towards maximizing the shareholders' wealth.

• Korean Journal of Ichthyology
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• v.32 no.2
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• pp.70-77
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• 2020

A feeding experiment was conducted to investigate the effects of replacement of dietary fish meal by frozen whole krill (FWK) and/or krill meal (KM) on growth performance and body composition of juvenile black rockfish, Sebastes schlegeli. The basal experimental diet (ED) contained 58.4% fish meal (FM) as a control, the other five EDs were formulated with the protein replacement ratio of fish meal by as 0, 10, 20, 30, and 40%, respectively (FWKM0, FWK10, FWK20, FWK20KM10, FWK20KM20 and FWK20KM20HP). Each diet was fed to juvenile rockfish initially weighing 3.09±0.02 g/fish in a flow-through system. The control ED containing 58.4% FM and 10% FWK diet showed significantly higher weight gain and feed efficiency than all the other EDs containing 20, 30, and 40% FWK and/or KM. But the survivals, whole-body moistures, crude proteins and lipids of black rockfish fed all EDs were similar in all EDs. The only whole-body ashes of juvenile black rockfish were significantly differentiated by feeding the various EDs containing different levels of FWK and/or KM with a protein and lipid levels adjustment. These results suggest that dietary frozen whole Antarctic krill and/or krill meal inclusions could not improve the growth but change the whole-body ashes in juvenile black rockfish. Therefore, this study further indicates that dietary more than 20% of FWK and/or KM supplementation could not be a potential source of animal protein to replace fishmeal in juvenile black rockfish.

• Korean Journal of Ichthyology
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• v.32 no.2
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• pp.39-48
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• 2020

The slender shinner (Pseudopungtungia tenuicorpa), a tiny freshwater fish of about 8 to 10 cm belonging to Cyprinidae, is an endangered species found only in the Han and Imjin Rivers on the Korean Peninsula. During the breeding season, this species spawns in nests of Coreoperca herzi, a predator of this species, or small crevices on rocks. This unique reproductive ecology can make this species more vulnerable to anthropogenic perturbance that can further limit the places to spawn. Here, mtDNA and microsatellite loci were analyzed to identify the genetic diversity and structure of slender shinners and further to provide the basic data necessary for the conservation planning of this species. A total of 28 polymorphic microsatellite markers were developed using Illumina paired-end sequencing, and 67 slender shinners collected from three localities in the Han River were genotyped using these loci. This species showed a remarkably high level of genetic diversity with mean expected heterozygosity of 0.914 and mean allele number per locus of 27.9, and no signature of drastic demographic decline was detected. As a result of our microsatellite analysis, the genetic structure between the two stems of the Han River, North Han and South Han, was prominent. Such a genetic structure was also evident in the sequence analysis of 14 haplotypes obtained from mtDNA control region. Although slender shinners are only found in very limited areas around the world, the genetic structure indicates that there is a block of gene flow among the populations, which should be reviewed in the future if management and restoration of this species is needed.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.1
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• pp.111-119
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• 2020

In vascular smooth muscle, K⁺ channels, such as voltage-gated K⁺ channels (Kv), inward-rectifier K⁺ channels (Kir), and big-conductance Ca²⁺-activated K⁺ channels (BK_Ca), establish a hyperpolarized membrane potential and counterbalance the depolarizing vasoactive stimuli. Additionally, Kir mediates endothelium-dependent hyperpolarization and the active hyperemia response in various vessels, including the coronary artery. Pulmonary arterial hypertension (PAH) induces right ventricular hypertrophy (RVH), thereby elevating the risk of ischemia and right heart failure. Here, using the whole-cell patch-clamp technique, we compared Kv and Kir current densities (I_Kv and I_Kir) in the left (LCSMCs), right (RCSMCs), and septal branches of coronary smooth muscle cells (SCSMCs) from control and monocrotaline (MCT)-induced PAH rats exhibiting RVH. In control rats, (1) I_Kv was larger in RCSMCs than that in SCSMCs and LCSMCs, (2) I_Kv inactivation occurred at more negative voltages in SCSMCs than those in RCSMCs and LCSMCs, (3) I_Kir was smaller in SCSMCs than that in RCSMCs and LCSMCs, and (4) I_BKCa did not differ between branches. Moreover, in PAH rats, I_Kir and I_Kv decreased in SCSMCs, but not in RCSMCs or LCSMCs, and I_BKCa did not change in any of the branches. These results demonstrated that SCSMC-specific decreases in I_Kv and I_Kir occur in an MCT-induced PAH model, thereby offering insights into the potential pathophysiological implications of coronary blood flow regulation in right heart disease. Furthermore, the relatively smaller I_Kir in SCSMCs suggested a less effective vasodilatory response in the septal region to the moderate increase in extracellular K⁺ concentration under increased activity of the myocardium.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.439-444
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• 2017

The ability of nematodes to manipulate the immune system of their host towards a Th2 and T regulatory responses has been proposed to suppress the inflammatory response. Clinical trials have proposed a useful effect of helminth infections on improvement of inflammatory disorders. In this study, we investigated the immunomodulatory effect of Syphacia obvelata infection to induce intestinal tolerance in C57BL/6 mice. Mice were infected through the cagemates with self-infected BALB/c mice. Four weeks post-infection, expression levels of $IFN-{\gamma}$, $TNF-{\alpha}$, IL-17, and IL-10 were assessed in the supernatant of mesenteric lymph node (MLN) culture. $Foxp3^+Treg$ were measured in MLN cells by flow cytometry. In the S. obvelata-infected group, the percentage of Tregs ($5.2{\pm}0.4$) was significantly higher than the control ($3.6{\pm}0.5$) (P<0.05). The levels of IL-10 ($55.3{\pm}2.2$ vs $35.2{\pm}3.2$), IL-17 ($52.9{\pm}3.8$ vs $41{\pm}1.8$), $IFN-{\gamma}$ ($44.8{\pm}4.8$ vs $22.3{\pm}2.3$) and $TNF-{\alpha}$ ($71.1{\pm}5.8$ vs $60.1{\pm}3.3$) were significantly increased in infected mice compared to the control group (P<0.05). The above results showed the potential effects of S. obvelata to induce intestinal tolerance. Therefore, it seems that S. obvelata may increase the immunological suppressive function in the intestinal tract.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.161-168
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• 2016

Nucleotide metabolism in endothelium is variable between different species. Recent studies demonstrated that this variability could contribute coagulation dysfunction, even though organs of the alpha 1,3-galactosyltransferase gene knockout pig were transplanted into the primate. CD73 (ecto-5'-nucelotidase) is an enzyme at cell surface catalyzing the hydrolysis of adenosine triphosphate to adenosine, which plays role on a substance for anti-inflammatory and anti-coagulant. Thus, overexpression of CD73 in endothelial cells of the pig is considered as an approach to reduce coagulopathy. In this study, we constructed a human CD73 expression vector under control of porcine Icam2 promoter (pIcam2-hCD73), which is expressed specifically at endothelial cells, and of CMV promoter as a control (CMV-CD73). First, we transfected the CMV-CD73 vector into HEK293 cells, and then confirmed CD73 expression at cell surface by flow cytometry analysis. Next, we transfected the pIcma2-CD73 and CMV-CD73 vectors into primary porcine fibroblasts and endothelial cells. Consequence was that the pIcma2-CD73 vector was expressed only at the porcine endothelial cells, meaning that the pIcam2 promoter lead to endothelial cell-specific expression of CD73 in vitro. Finally, we nucleofected the pIcam2-hCD73 vector into passage 3 fibroblasts, and enforced hygromycin selection of 400mg/ml. We were able to obtain forty three colonies harboring pIcam2-CD73 to provide donor cells for transgenic cloned porcine production.