• Title/Summary/Keyword: Anti-jam

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Analysis of Anti-jamming for GPS Guided Missile by GPS Reception Azimuth Control (GPS 수신 방위각 제어를 통한 GPS 유도무기 재밍대응 분석)

  • Choi, Chang-Mook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.3
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    • pp.677-682
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    • 2016
  • Recently, because Global Positioning System (GPS) achieves accuracy for engagement of enemy targets, GPS guided weapons have a wide range of applications from land through sea to air. Especially, when GPS guided weapon is then launched, it reads current position and searches a course to the target. As we all know, because GPS signals are weak, these signals can be affected by interference. If jamming signal is strong enough, it can jam the receiver of GPS guided weapon. Therefore, anti-jamming technique is an important thing under these conditions. In this paper, the controlling azimuth angle was used to improve navigation performance of precision guided missile under jamming conditions. First of all, precision missiles by GPS positioning such as SLAM-ER and JDAM were investigated. Also, the azimuth cutoff angle of satellites for usable navigation under jamming signals was analyzed by experimental tests. As a result, we found that azimuth cutoff angle under 140 degree can help ensure continuous GPS reception under the missile guidance.

Extracts of Artemisia princeps Pampanini Inhibit Lipopolysaccharide-induced Nitric Oxide, Cyclooxygenase-2, Prostaglandin $E_2$, and Tumor Necrosis Factor-$\alpha$ Production from Murine Macrophage RAW 264.7 Cells (강화사자발쑥의 마크로파지 RAW 264.7세포에 대한 Tumor Necrosis Factor-$\alpha$, Prostaglandin $E_2$, Cyclooxygenase-2 및 LPS 유도 Nitric Oxide 생성 저해)

  • Yun, Jun-Yong;Choi, Se-Yong;Park, Pyo-Jam;Chung, Hae-Gon;Shin, Heung-Mook;Suk, Kyoung-Ho;Lim, Beong-Ou
    • Korean Journal of Medicinal Crop Science
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    • v.16 no.5
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    • pp.326-331
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    • 2008
  • To search for immunoactive natural products exerting anti-inflammatory activity, we have evaluated the effects on the water extracts of Artemisia princeps Pampanini (APP) on lipopolysaccharide-induced nitric oxide (NO), tumor necrosis factor-$\alpha$ (TNF-$\alpha$), and prostaglandin $E_2$ ($PGE_2$) production by RAW 264.7 macrophage cell line. Our data indicate that this extract is a potent inhibitor of NO production and it also significantly decreased PGE2 and TNF-$\alpha$ production. Consistent with these results, the protein and mRNA expression level of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) was inhibited by water extracts of APP in a dose-dependent manner. These results suggest that APP may exert anti-inflammatory and analgesic effects possibly by suppressing the inducible NO synthase and COX-2 expressions.

Performance Analysis of Link-16 Waveform considering Frequency Remapping under PBNJ (부분대역 잡음 재밍 환경에서의 주파수 재할당을 고려한 Link-16 성능 분석)

  • Lee, Kyuman;Noh, Hongjun;Lee, Jongkwan;Lim, Jaesung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38C no.11
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    • pp.955-965
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    • 2013
  • The joint tactical information distribution system (JTIDS) is used as the communication terminal of Link-16 by the United States armed forces, north atlantic treaty organization (NATO), and other allied forces. A portion of Link-16 frequencies may be shortly remapped to other systems owing to the growing demand for frequencies, especially in civil aviation, which is witnessing a constant increase in air traffic. This will affect the performance of Link-16. Therefore, in this paper, we analyze the effect of frequency band reduction on the performance of Link-16 waveform under partial-band noise jamming with Nakagami fading, via simulation and numerical analysis. The multi-net and anti-jamming performance of Link-16 with frequency remapping is compared with that of conventional Link-16 systems. The results show that the performance of Link-16 waveform is degraded with the reduction in frequencies. Nonetheless, Link-16 retains its jam resistance, and it can support multiple users in the same time slots.

Investigation of the effect of Lithospermi Radix on tight-junction related genes in HaCaT cells (자초(紫草) 열수추출물이 각질형성세포 HaCaT의 세포 연접 관련 유전자의 발현에 미치는 영향 연구)

  • Cho, Namjoon;Lee, Byeongkwon;Lee, Woonghee;Kim, Keekwang;Kim, Kyoon Eon;Han, Hyosang
    • The Korea Journal of Herbology
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    • v.32 no.3
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    • pp.55-61
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    • 2017
  • Objectives : The aim of this research was to determine the diverse effects of Lithospermi Radix Water Extract (LR) on human keratinocyte HaCaT cells, and to examine whether those effects could be applied to the human skin. Methods : We examined effect of LR on the cell viability of using the MTS assay in human keratinocyte HaCaT cells. The antioxidation effect of LR was analyzed relative to the well-known antioxidant resveratrol, using an ABTS assay. Quantitative RT-PCR analysis revealed that, in HaCaT cells, LR influenced the mRNA expression of tight-junction genes associated with skin moisturization. Furthermore, a wound-healing assay demonstrated altered cell migration in LR-treated HaCaT cells. Result : The cytotoxicity was confirmed to be higher in LR at a concentration of $800{\mu}g/m{\ell}$ using the MTS assay in HaCaT cells. In comparison to $100{\mu}M$ resveratrol, $1,600{\mu}g/m{\ell}$ LR showed either a similar or superior antioxidation effect. LR treatment in HaCaT cells reduced the mRNA expression levels of claudin 3, claudin 4, claudin 6, claudin 8, and ZO-2 to less than 0.80-fold, whereas JAM-A and Tricellulin mRNA expression level increased more than 1.33-fold. In addition, HaCaT cells migration was decreased to 83.9% by LR treatment. Conclusions : LR of antioxidation activity will have an anti-aging effect on the skin by reducing oxidative stress. Further studies are required to address the implications for human skin, given LR's effects of altering mRNA expression of tight junction-related gene and decreasing cell migration of HaCaT cells.

Anti-Inflammatory Activities of Extracts from Fermented Taraxacum platycarpum D. Leaves Using Hericium erinaceum Mycelia (노루궁뎅이버섯 균사체로 발효한 민들레잎 추출물의 항염증 활성)

  • Kim, Yon-Suk;Joung, Mi-Yeun;Ryu, Beom-Seok;Park, Pyo-Jam;Jeong, Jae-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.1
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    • pp.20-26
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    • 2016
  • This study investigated the fermentation effect of Taraxacum platycarpum Dahlst. leaf extracts using Hericium ernaceum mycelia to test antioxidant and anti-inflammatory activities in vitro. The antioxidant activities of fermented or non-fermented extracts of T. platycarpum leaves were determined by 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, ferric reducing antioxidant power, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity. The leaf extract of T. platycarpum showed higher antioxidant activity than extract of fermented leaves. However, ethanolic extract of fermented T. platycarpum leaves decreased levels of nitric oxide production and pro-inflammatory cytokines such as interleukin-6 and tumor necrosis factor-${\alpha}$ in lipopolysaccharide-stimulated RAW 264.7 cells. Moreover, fermented leaf extract suppressed protein expression of inducible nitric oxide synthase in RAW 264.7 cell culture. Therefore, the enhanced anti-inflammatory activity of ethanolic extracts of fermented T. platycarpum leaves might be attributed to the molecular conversion of leaf ingredients during fermentation and the active ingredients might have specific affinity with ethanol during extraction.

Bioconverted Jeju Hallabong tangor (Citrus kiyomi × ponkan) peel extracts by cytolase enhance antioxidant and anti-inflammatory capacity in RAW 264.7 cells

  • Chang, Yun-Hee;Seo, Jieun;Song, Eunju;Choi, Hyuk-Joon;Shim, Eugene;Lee, Okhee;Hwang, Jinah
    • Nutrition Research and Practice
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    • v.10 no.2
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    • pp.131-138
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    • 2016
  • BACKGROUND/OBJECTIVES: Citrus and its peels have been used in Asian folk medicine due to abundant flavonoids and usage of citrus peels, which are byproducts from juice and/or jam processing, may be a good strategy. Therefore, the aim of this study was to examine antioxidant and anti-inflammatory effects of bioconversion of Jeju Hallabong tangor (Citrus kiyomi ${\times}$ ponkan; CKP) peels with cytolase (CKP-C) in RAW 264.7 cells. MATERIALS/METHODS: Glycosides of CKP were converted into aglycosides with cytolase treatment. RAW 264.7 cells were pre-treated with 0, 100, or $200{\mu}g/ml$ of citrus peel extracts for 4 h, followed by stimulation with $1{\mu}g/ml$ lipopolysaccharide (LPS) for 8 h. Cell viability, DPPH radical scavenging activity, nitric oxide (NO), and prostagladin $E_2$ ($PGE_2$) production were examined. Real time-PCR and western immunoblotting assay were performed for detection of mRNA and/or protein expression of pro-inflammatory mediators and cytokines, respectively. RESULTS: HPLC analysis showed that treatment of CKP with cytolase resulted in decreased flavanone rutinoside forms (narirutin and hesperidin) and increased flavanone aglycoside forms (naringenin and hesperetin). DPPH scavenging activities were observed in a dose-dependent manner for all of the citrus peel extracts and CKP-C was more potent than intact CKP. All of the citrus peel extracts decreased NO production by inducible nitric oxide synthase (iNOS) activity and $PGE_2$ production by COX-2. Higher dose of CKP and all CKP-C groups significantly decreased mRNA and protein expression of LPS-stimulated iNOS. Only $200{\mu}g/ml$ of CKP-C markedly decreased mRNA and protein expression of cyclooxygenase-2 in LPS-stimulated RAW 264.7 cells. Both 100 and $200{\mu}g/ml$ of CKP-C notably inhibited mRNA levels of $interleukin-1{\beta}$ ($IL-1{\beta}$) and IL-6, whereas $200{\mu}g/ml$ CKP-C significantly inhibited mRNA levels of $TNF-{\alpha}$. CONCLUSIONS: This result suggests that bioconversion of citrus peels with cytolase may enrich aglycoside flavanones of citrus peels and provide more potent functional food materials for prevention of chronic diseases attributable to oxidation and inflammation by increasing radical scavenging activity and suppressing pro-inflammatory mediators and cytokines.

Effects of mulberry fruit juice powder on inflammation and microRNA-132/143 regulation in 3T3-L1 adipocytes (뽕나무 열매 착즙 분말이 3T3-L1 지방세포의 염증 및 microRNA-132/143 조절에 미치는 영향)

  • Lee, Mak-Soon;Kim, Yangha
    • Journal of Nutrition and Health
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    • v.54 no.5
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    • pp.448-458
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    • 2021
  • Purpose: Mulberry (Morus alba L.) fruit is widely grown in Asia and consumed as fresh fruit, jam, and juices. The fruit has beneficial health effects, including anti-diabetic, anti-tumor, and anti-obesity properties. However, the mechanisms by which mulberry fruit juice powder (MJ) regulates inflammatory microRNAs (miRs) are not yet known. This study investigated the effect of mulberry fruit juice powder on the regulation of inflammation and miR-132/143 during 3T3-L1 adipocyte differentiation. Methods: The 3T3-L1 cells were induced to differentiate for 2 days and then treated with various concentrations of MJ for 7 days. Cytotoxicity was determined by evaluating cell viability using a water-soluble tetrazolium salt-8 assay kit. Intracellular lipid accumulation was evaluated by oil-red O staining. The levels of the expression of genes involved in adipogenesis and inflammation, and miR-132/143 were measured by quantitative real-time polymerase chain reactions. Results: MJ showed no cytotoxic effect on 3T3-L1 adipocytes at concentrations below 100 ng/mL. Intracellular lipid accumulation was reduced by MJ treatment at concentrations of 100 ng/mL. The messenger RNA (mRNA) levels of proliferator-activated receptor-γ, cytosine-cytosine-adenosine-adenosine-thymidine/enhancer-binding protein-α, and adipocyte protein 2, which are involved in adipogenesis, were suppressed by MJ. A reduction was also seen in mRNA levels of genes related to the inflammatory response, such as tumor necrosis factor-α, interleukin-6, monocyte chemoattractant protein-1, and inducible nitric oxide synthase. The expression of the inflammatory miR-132 and miR-143 was also decreased by MJ. Conclusion: These results suggest that MJ may suppress adipogenesis and inflammation through the regulation of miR-132/143 expression in 3T3-L1 adipocytes. Thus, MJ may be useful as a food agent that prevents obesity-associated inflammation.

Inhibitory Effect of Scutellaria baicalensis Root Extract on Chemical Mediator Release and Immune Response

  • Choi, Se-Young;Choi, Dong-Kug;Park, Pyo-Jam;Choi, Wahn-Soo;Kim, Jong-Dai;Shin, Heung-Mook;Lim, Beong-Ou
    • Korean Journal of Medicinal Crop Science
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    • v.15 no.2
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    • pp.132-137
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    • 2007
  • Inhibitory effect of Scutellaria baicalensis ethanol extracts (SR) on chemical mediator release and immunoglobulin (Ig) production from Sprague-Dawley rats originated cells as type I allergic reaction was examined. SR showed concentration-dependent inhibition on basal and concanavalin A (ConA)-stimulated Ig production. In the mesenteric lymph node lymphocytes, the inhibitory effect of SR on the IgE production in the presence of Con A was stronger than these on IgA and IgG production. Moreover, tumor necrosis factor-alpha $(TNF-{\alpha})$ production-inhibiting effect of SR in the presence ConA was observed. However, SR did not affect the production of $interferon-{\gamma}$. SR also inhibited histamine release from the peritoneal exudate cells stimulated with a calcium ionophore A23187. In the case of leukotriene B4, SR markedly inhibited it at the concentration of 100 mg/ml. From these results, ethanol extracts obtained from Scutellaria baicalensis may have an anti-allergic effect on the intestinal system of rats.

Investigation of the Antioxidant Effect of Angelicae Radix from Korea, China and Japan (참당귀, 중국당귀, 일당귀의 차등적 항산화 효능 연구)

  • Cho, Nam Joon;Lee, Woong Hee;Kim, Kee Kwang;Han, Hyo Sang
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.31 no.3
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    • pp.182-187
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    • 2017
  • The purpose of the present study is a comparison of the antioxidant effects of Angelica gigas Korea (AG), Angelica sinensis of China (AS), and Angelica acutiloba of Japan (AA), and comparison of the effects of AG, AS and AA on tight-junction related genes in human keratinocyte HaCaT cells. All species showed a strong antioxidant effect, and AA was higher than AG and AS in antioxidant effects. The cytotoxicity was confirmed to be higher in AS than AG and AA at a concentration of $1,600{\mu}g/ml$ using the MTS assay in HaCaT cells. We analyzed the effects of AG, AS, and AA on mRNA expression levels of various tight-junction related genes in HaCaT cells. We found that no obvious changes in expression of Claudin 1, 3, 4, 6, 7, 8, Occludin, JAM-A, ZO-1, ZO-2, and tricellulin by treatment of all species, suggesting that there is less possibility of side effects and skin moisturizing effects due to changes in tight-junction gene expression. Our results suggest that AG, AS, and AA are thought to be effective in reducing the oxidative stress of the skin and preventing the aging of the skin.

Anti-Inflammatory Effects of Extracts from Ligustrum ovalifolium H. Leaves on RAW264.7 Macrophages (RAW264.7 대식세포에서 왕쥐똥나무잎 추출물의 항염증 효과)

  • Kim, Yon-Suk;Lee, Seung-Jae;Hwang, Jin-Woo;Kim, Ee-Hwa;Park, Pyo-Jam;Jeong, Jae-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.9
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    • pp.1205-1210
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    • 2012
  • This study investigated the anti-inflammatory effects of Ligustrum ovalifolium H. (LOH) leaf extracts on RAW264.7 macrophages. Cell toxicity was determined by MTT assay. We evaluated the anti-inflammatory effects of LOH extracts by measuring nitric oxide (NO), reactive oxygen species (ROS), inducible NOS (iNOS) production, and cyclooxygenase-2 (COX-2) expression by Western blotting. LOH ethanolic extracts (0.05, 0.1, and 0.2 mg/mL) significantly suppressed LPS-stimulated production of NO. The intracellular ROS level also significantly decreased. LOH ethanolic extracts reduced the expression of iNOS and COX-2 proteins. The present results show that LOH ethanol extract has potent anti-inflammatory effects on RAW264.7 macrophages. These results also suggest that the anti-inflammatory effects of LOH extracts may be related to the inhibition of LPS-stimulated ROS and NO production. Therefore, ethanolic extracts of LOH leaves may be utilized as a good source of functional foods for protection against inflammatory diseases.