• The Journal of Korean Institute of Communications and Information Sciences
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• v.5 no.1
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• pp.40-43
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• 1980

The Service area in AM Broadcast Changes according to its transmitting frequency. It is also reduced by increase of the citizen noise. As a result, the efficency of transmitting Antenna should be higer in a low noise region as long as AM Broadcast does not build up its transmitting power. The efficiency of transmitting Antenna can also function as a low resistance connection to earth. Most Vertical Antenna used in the AM standard Broadcast band in the Korea have extensive radial ground systems beneath them which serve as image plane.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.8
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• pp.773-780
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• 2015

Traditionally, additive manufacturing (AM) technology has been used to fabricate prototypes in the early development phase of a product. This technology is being applied to release manufacturing of a product because of its low cost and fast fabrication. AM technology is a process of joining materials to fabricate a product from the 3D CAD data in a layer-by-layer manner. The orientation of a layer during manufacturing can affect the mechanical properties of the product because of its anisotropy. In this paper, tensile testing of polymer-based specimens were built with a typical AM process (FDM, PolyJet and SLA) to study the mechanical properties of the AM materials. The ASTM D 638 tensile testing standard was followed for building the specimens. The mechanical properties of the specimens were determined on the basis of stress-strain curves formed by tensile tests. In addition, the fracture surfaces of the specimens were observed by SEM to analyze the results.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.1
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• pp.70-79
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• 2000

Arbuscular mycorrhizal(AM) fungi have significant role for ecosystem structure and function. They are the major component of forest soil ecosystems and critically important for water and nutrient cycling in the system. To understand the ecology of AM fungi the fungal spores were collected, identified and counted in forest soils under various climatic and edaphic conditions. In relation to soil depth 90% of AM fungi spores and mycorrhizas distributed within 15cm soil depth. Number of spores per $100m{\ell}$ forest soil volume was 5 to 36 spores from 1 to 3 fungal species. AM fungal species diversity was higher in warmer climates, and more moist and fertile soils. The most frequently found species were Gigaspora decipiens irrespective of soil moisture and Gi. gigantea irrespective of soil fertility. In the Jeju island the soils of Cryptomeria japonica plantations and Miscanthus sinensis var. purpurascens meadow had more AM spores than the other soils. We suggest AM fungi be considered as keystones species when restoring a disturbed forest ecosystem.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.277-284
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• 2011

To investigate the effects of arbuscular mycorrhizal (AM) symbiosis on N uptake and its assimilation under drought-stressed conditions in white clover, total $^{15}N$ amount and $^{15}N$ amount incorporated into $NO_3^-$, amino acids and soluble proteins were quantified by $^{15}N$ tracing during 7 days of water treatment. Under well-watered conditions, there were no significant effects of AM symbiosis on all parameters analyzed in this study. Drought stress decreased total $^{15}N$ amount both in AM and non-AM plants, with a lower rate in AM plants (-13.8%) relative to non-AM plants (-28.5%) at day 7. Drought significantly increased $^{15}N-NO_3^-$ amount in non-AM plants. The amount of $^{15}N$-amino acids was 1.26-fold and 1.33-fold higher, respectively, in leaves and roots of AM plants compared to those of non-AM ones. Drought decreased the amount of $^{15}N$-soluble proteins in leaves at day 7, with a higher rate in non-AM plants than in AM ones. These results clearly indicate that AM colonization effectively alleviating the decrease in N uptake, amino acids and proteins synthesis caused by drought stress.

• The Korea Journal of Herbology
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• v.37 no.1
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• pp.19-29
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• 2022

Objectives : Although the pharmacological effects of anti-inflammatory and antioxidant action of Atractylodes macrocephala Koidzumi water extract (AM) have been proven from many studies, reports on the antioxidant effect of AM on ulcerative colitis (UC) are scarce. Therefore, we aimed at evaluating the anti-oxidant effect of AM on the DSS-induced UC model. Methods : To induce ulcerative colitis, 8-week-old male Balb/c mice received 5% DSS in drinking water for 1 week. After 1 week of adaptation, mice were divided into four groups (n=8 each) for use as normal (Normal), DSS Control (Control), DSS + AM 100 mg/kg (AM100)-treatment, DSS + AM 200 mg/kg (AM200)-treatment. After 1 week of the experiment, the animals were sacrificed, and the extracted colon tissue was analyzed for protein through western blot. Results : As a result of confirming the macroscopic changes in colon tissues to confirm the therapeutic effects of AM, the decrease in colon length was suppressed in the AM treatment group compared to the control group. In addition, as a result of biochemical analysis, AM administration significantly reduced serum glutamic oxalacetic transaminase, glutamic pyruvate transaminase levels and tissue malondialdehyde levels. As a result of confirming the protein expression level through western blot, AM administration significantly decreased the expression of NADPH-related proteins such as NOX2, p22^phox, and iNOS, but significantly increased the expression of SOD, catalase, and GPx-1/2. Conclusions : AM may improve DSS-induced UC in mice by modulating NADPH and antioxidant-related proteins. In conclusion, AM showed an antioxidant effect through the improvement of oxidative stress on UC.

• BMB Reports
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• v.38 no.1
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• pp.41-48
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• 2005

In this study we developed the transposon-mediated shuttle vector 'Hanpvid', which composed of HaNPV (Heliothis armigera nuclear polyhedrosis virus) genomic DNA and a transposon cassette from Bacmid of Bac-to-Bac system. Hanpvid replicates in E. coli in the same way as Bacmid and retains infective function in cotton bollworm cells (Hz-AM1). Using Hanpvid we constructed a recombinant virus, which could infect Hz-AM1 cells and generate recombinant HaNPV (rHa-Bar) containing the barnase gene, a ribonuclease gene from Bacillus amyloliquefaciens. Since the expression vector carrying barnase gene cannot replicate in the absence of barstar, a specific inhibitor of barnase, we constructed a new cotton bollworm cell line (AM1-NB) using the marker rescue method. In AM1-NB barstar was integrated into the cellular chromosome to sustain the replication of rHa-Bar. To screen out recombinant HaNPV for potential use as biopesticide, Hz-AM1 and AM1-NB cell lines were infected with rHa-Bar, respectively. The results obtained indicate that Viral progenies in AM1-NB were 23 and 160 times greater than those in Hz-AM1 48 h and 72 h after infection, respectively. With additional insertion of the polyhedron gene from AcNPV (Autographa californica nuclear polyhedrosis virus) into the Hanpvid genome, rHa-Bar regained the polyhedron phenotype and its pest-killing rate greatly improved. Toxic analysis showed that the lethal dosages ($LD_{50}$) and the lethal time(s) ($LT_{50}$) of rHa-Bar were reduced by 20% and 30%, respectively, compared to wt-HaNPV in the third instar larvae of cotton bollworm. This study shows that in AM1-NB barnase can be effectively produced and used as pest-killing agent for the biological control of cotton pests.

• The Korean Journal of Physiology
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• v.30 no.1
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• pp.77-83
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• 1996

Platelet-activating factor(PAF) is a phospholipid mediator of pulmonary inflammation, and immunologic reaction. In this study, the role of PAF on tumor necrosis factor$(TNF_{-{\alpha}})$ production by rat alveolar macrophages(AM) was examined. When PAF $(10^{-12}{\sim}10{-16}\;M)$ alone was added to AM culture, $(TNF_{-{\alpha}})$ production was not significantly increased above the resting level. In contrast, the combined addition of PAF $(10^{-6}\;M)$ and muramyl dipeptide(MDP) $(1.0\;{\mu}g\ml)$ to AM cultures markedly enhanced $(TNF_{-{\alpha}})$ production with 8.2 fold increase compared with AM culture in resting state. This potentiative effect was 313% above the sum of the separate effects of PAF and MDP. To characterize MDP effects on $(TNF_{-{\alpha}})$ production, the dose-response of AM cultured with various concentrations of MDP was tested. High level of MDP $(10\;{\mu}g\ml)$ could not significantly enhance the potentiation effect on $(TNF_{-{\alpha}})$ production compared with AM cultures with low level of MDP $(0.1\;{\mu}g\ml)$, i.e. 112.5% vs 107.8%, respectively when $10^{-10}$ M of PAF was simultaneously added to the cell culture. These data support that the potentiation of TNF. g production in AM culture is mediated by PAF rather than MDf It was also evaluated whether the similar result was obtained in silica, respirable toxic particle-treated AM culture. $(TNF_{-{\alpha}})$ production was also significantly enhanced in the PAF $(10^{-6}\;M)$ and silica $(50\;{\mu}g\ml)$-added cell cultures with 4.7 fold above the value of silica alone-stimulated cells. These results indicate that PAF can potentiate $(TNF_{-{\alpha}})$ production by MDP-or silica- stimulated AM and suggest that PAF may play a potent role in lung inflammation and disease associated with microbe and occupational dust exposures.

• Journal of Acupuncture Research
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• v.38 no.3
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• pp.183-191
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• 2021

Sa-am acupuncture originated in the Chosun Dynasty and is a distinct feature of Korean medicine. It has been used to treat various diseases and conditions in clinical practice however, there is insufficient scientific evidence to support the use of Sa-am acupuncture. We aimed to comprehensively review the clinical studies of Sa-am acupuncture retrieved from national and international databases (MEDLINE, EMBASE, the China National Knowledge Infrastructure, and 3 Korean databases). There were 52 articles reviewed including 29 case studies, 19 randomized controlled trials (RCTs), and 4 uncontrolled trials. Neurological disorders were the most frequently studied, and kidney tonification, and directional supplementation and draining were the most frequently used methods. Overall, the outcomes were generally positive however, there were many additional treatments together with Sa-am acupuncture reported in the case reports, and the quality of evidence was low in the RCTs. Future studies should report the detailed method of practicing Sa-am acupuncture treatment and focus on the specific effect of Sa-am acupuncture with rigorous design to scientifically support the clinical use of Sa-am acupuncture.

• Journal of Acupuncture Research
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• v.27 no.6
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• pp.23-30
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• 2010

Objectives : This study was undertaken in order to establish the composite principles of fomulas through the of Sa-am acupuncture therapy and the theory of sovereign, minister, assistant and courier. Methods : We analyzed the formula construction of Sa-am acupuncture therapy, and applied the theory of sovereign, minister, assistant and courier that was referred to in the preface of "Essential Rhymes on Acupuncture and Moxibustion by Master Sa-am" to the analysis of formula construction. Results & Conclusions : 1. Sa-am acupuncture therapy was acupuncture and moxibustion method that inherited and developed progress contents of Chinese traditional acupuncture and moxibustion. 2. The theory of sovereign, minister, assistant and courier was based on the idea that acupuncture and herbal medicine had the same origins. 3. Formula constructions of Sa-am acupuncture therapy were formed complicatedly, but reflected the theory of sovereign, minister, assistant and courier. 4. The supplementing acupuncture point that is Chunbu-point in other merdian became Sovereign, the draining acupuncture point that is Chunbu-point in other merdian became Minister, and the supplementing and draining acupuncture points in same merdian became Assistant and Courier that mean leading merdian points.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.4
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• pp.315-319
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• 2009

Astragalus Membranaceus (AM) is a useful Korean herb that has been clinically prescribed for stress-related illness. The objective of the present study was to examine the anti-stress effects of AM on repeated stress-induced alterations of anxiety, learning and memory in rats. Restraint stress was administered for 14 days (2h/day) and AM (400mg/kg) given by oral administration, in the AM group, for the same period. Starting on the eighth day, the rats were tested for spatial memory on the Morris water maze test (MW) and for anxiety on the elevated plus maze (EPM). Changes of expression on immunohistochemistry were studied for cholineacetyl transferase (ChAT) and tyrosine hydroxylase (TH) in the brain. The results showed that the rats treated with AM had significantly reduced stress-induced deficits on learning and memory on the spatial memory tasks. In addition, the ChAT immunoreactivities were increased. In the EPM, treatment with AM increased the time spent in the open arms (p<0.001) compared to the control group. In addition, AM treatment also normalized increases of TH expression in the LC (p<0.001). In conclusion, administration of AM improved spatial learning and memory and reduced stress-induced anxiety. Thus, the present results suggest that AM is able to recover behavioral and neurochemical impairments induced by stress.