• Title/Summary/Keyword: Biological Agents

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Magnetic fields-assisted movement of iron oxide-nanoparticles-incorporated large scale alginate capsules

  • Lee, Dohyeon;Park, Sunho;Kim, Daun;Nam, Hyeun;Kim, Jangho
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2017.04a
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    • pp.27-27
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    • 2017
  • Biocompatible capsules have recently been highlighted as novel delivery platforms of any "materials" (e.g., drug, food, agriculture pesticide) to address current problems of living systems such as humans, animals, and plats in academia and industry for agriculture, biological, biomedical, environmental, food applications. For example, biocompatible alginate capsules were proposed as a delivery platform of biocontrol agents (e.g., bacterial antagonists) for an alternative to antibiotics, which will be a potential strategy in future agriculture. Here, we proposed a new platform based on biocompatible alginate capsules that can control the movements as an active target delivery strategy for various applications including agriculture and biological engineering. We designed and fabricated large scale biocompatible capsules using alginates and custom-made nozzles as well as gelling solutions. To develop the active target delivery platforms, we incorporated the iron oxide nanoparticles in the large scale alginate capsules. It was found that the sizes of large scale alginate capsules could be controlled via various working conditions such as concentrations of alginate solutions and iron oxide nanoparticles. As a proof of concept work, we showed that the iron oxide particles-incorporated large scale alginate capsules could be moved actively by the magnetic fields, which would be a strategy as active target delivery platforms for agriculture and biological engineering (e.g., controlled delivery of agriculture pesticides and biocontrol agents).

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Effects of Biological Control Agent Algicidal Bacterium on the Phytoplankton Community and Microcystin-LR Contents in a Mesocosm Experiment (살조세균 적용이 식물플랑크톤 군집과 조류독소 분포에 미치는 영향)

  • Jung, Seung-Won;Seo, Jong-Kun;Suh, Mi-Yeon;Han, Myung-Soo;Kim, Baik-Ho
    • Korean Journal of Ecology and Environment
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    • v.38 no.2 s.112
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    • pp.261-270
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    • 2005
  • Biological control agents (BCA; algicidal bacterium Xantobacter autotrophycus) plus casitone media, strongly changed physicochemical variables, standing crops of phytoplankton and microcystin-LR phytoplankton in 100-L mesocosm constructed in a small hexagonal pond (3.5 m ${\times}$ 5 m). No M. aeruginosa showed by 8 days, and 60% of total standing crops of phytoplanktons were decreased by the BCA treatment. BCA treatment also induced a strong decline of cellular extracted microcystin-LR (MCLR) and a remarkable increase of dissolved MCLR with the decrement in standing crops of cyanobacteria. In addition, BCA strongly increased all nutrients, but new outbreak of phytoplanktons hardly showed in the experimental mesocosm. The field application of BCA to controling the cyanobacterial bloom in large lakes and reservoirs is not relevant due to high concentration of nutrients and toxins. Thus, a further study is needed to diminish the adverse effects after BCA treatment for water quality preservation.

Investigations on Bacteria as a Potential Biological Control Agent of Summer Chafer, Amphimallon solstitiale L. (Coleoptera: Scarabaeidae)

  • Sezen Kazlm;Demir Ismail;Katl Hatice;Demirbag Zihni
    • Journal of Microbiology
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    • v.43 no.5
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    • pp.463-468
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    • 2005
  • Studying the bacteria of hazardous insects allows the opportunity to find potentially better biological control agents. Therefore, in this study, bacteria from summer chafer (Amphimallon solstitiale L., Coleoptera: Scarabaeidae) we isolated and identified the insecticidal effects of bacteria isolated from A. solstitiale and Melolontha melolontha L. (common cockchafer, Coleoptera: Scarabaeidae) and the mixtures of these bacterial isolates were investigated on A. solstitiale larvae. Crystals from Bacillus sp. isolated from M. melolontha were also purified, and tested against the second and third-stage larvae of A. solstitiale. The bacterial isolates of A. solstitiale were identified as Pseudomonas sp., Pseudomonas sp., Bacillus cereus and Micrococcus luteus, based on their morphology, spore formation, nutritional features, and physiological and biochemical characteristics. The insecticidal effects of the bacterial isolates determined on the larvae of A. solstitiale were $90\%$ with B. cereus isolated from A. solstitiale, and $75\%$ with B. cereus, B. sphaericus and B. thuringiensis isolated from M. melolontha within ten days. The highest insecticidal effects of the mixed infections on the larvae of A. solstitiale were $100\%$ both with B. cereus+B. sphaericus and with B. cereus+B. thuringiensis. In the crystal protein bioassays, the highest insecticidal effect was $65\%$ with crystals of B. thuringiensis and B. sphaericus isolated from M. melolontha within seven days. Finally, our results showed that the mixed infections could be utilized as microbial control agents, as they have a $100\%$ insecticidal effect on the larvae of A. solstitiale.

Countermeasure to the Stages of Crisis Management in the Bioterrorism (생물테러리즘의 위기관리방안)

  • Lee, Kwang-Lyeol
    • The Journal of the Korea Contents Association
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    • v.9 no.9
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    • pp.235-242
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    • 2009
  • This study aims to examine terrorism by biological agents. These days terrorism evolved so rapidly that more than one terror occurs a day in global society as we are on the edge of so-called New-terrorism. One of new examples of new terrorism is Bioterrorism by biological agents. In order to address Bioterrorism we should conduct a study to examine things to be prepared at ordinary times and future plans. As an effort to develop countermeasures against Bioterrorism, anti-terrorism laws should be made on Prevention phases anti-terrorism funding laws as well. Other Bioterrorism laws need to be made. On Response phases initial reaction task force should be ready for making positive initial reaction. A special hospital for CBR(Chemical, Biologlcal, and Radiological) warfare needs to be designated to practice medicine. Biological~safety-Levels should be constructed by IV levels. Effective public promotion network should be built. On Recovery phases evaluation system needs to be suggested and international cooperative network should be established.

Similarities and Distinctions in the Effects of Metformin and Carbon Monoxide in Immunometabolism

  • Park, Jeongmin;Joe, Yeonsoo;Ryter, Stefan W.;Surh, Young-Joon;Chung, Hun Taeg
    • Molecules and Cells
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    • v.42 no.4
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    • pp.292-300
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    • 2019
  • Immunometabolism, defined as the interaction of metabolic pathways with the immune system, influences the pathogenesis of metabolic diseases. Metformin and carbon monoxide (CO) are two pharmacological agents known to ameliorate metabolic disorders. There are notable similarities and differences in the reported effects of metformin and CO on immunometabolism. Metformin, an anti-diabetes drug, has positive effects on metabolism and can exert anti-inflammatory and anti-cancer effects via adenosine monophosphate-activated protein kinase (AMPK)-dependent and AMPK-independent mechanisms. CO, an endogenous product of heme oxygenase-1 (HO-1), can exert anti-inflammatory and antioxidant effects at low concentration. CO can confer cytoprotection in metabolic disorders and cancer via selective activation of the protein kinase R-like endoplasmic reticulum (ER) kinase (PERK) pathway. Both metformin and CO can induce mitochondrial stress to produce a mild elevation of mitochondrial ROS (mtROS) by distinct mechanisms. Metformin inhibits complex I of the mitochondrial electron transport chain (ETC), while CO inhibits ETC complex IV. Both metformin and CO can differentially induce several protein factors, including fibroblast growth factor 21 (FGF21) and sestrin2 (SESN2), which maintain metabolic homeostasis; nuclear factor erythroid 2-related factor 2 (Nrf2), a master regulator of the antioxidant response; and REDD1, which exhibits an anticancer effect. However, metformin and CO regulate these effects via different pathways. Metformin stimulates p53- and AMPK-dependent pathways whereas CO can selectively trigger the PERK-dependent signaling pathway. Although further studies are needed to identify the mechanistic differences between metformin and CO, pharmacological application of these agents may represent useful strategies to ameliorate metabolic diseases associated with altered immunometabolism.

Discovery of Chitin Deacetylase Inhibitors through Structure-Based Virtual Screening and Biological Assays

  • Liu, Yaodong;Ahmed, Sibtain;Fang, Yaowei;Chen, Meng;An, Jia;Yang, Guang;Hou, Xiaoyue;Lu, Jing;Ye, Qinwen;Zhu, Rongjun;Liu, Qitong;Liu, Shu
    • Journal of Microbiology and Biotechnology
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    • v.32 no.4
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    • pp.504-513
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    • 2022
  • Chitin deacetylase (CDA) inhibitors were developed as novel antifungal agents because CDA participates in critical fungal physiological and metabolic processes and increases virulence in soil-borne fungal pathogens. However, few CDA inhibitors have been reported. In this study, 150 candidate CDA inhibitors were selected from the commercial Chemdiv compound library through structure-based virtual screening. The top-ranked 25 compounds were further evaluated for biological activity. The compound J075-4187 had an IC50 of 4.24 ± 0.16 µM for AnCDA. Molecular docking calculations predicted that compound J075-4187 binds to the amino acid residues, including active sites (H101, D48). Furthermore, compound J075-4187 inhibited food spoilage fungi and plant pathogenic fungi, with minimum inhibitory concentration (MIC) at 260 ㎍/ml and minimum fungicidal concentration (MFC) at 520 ㎍/ml. Therefore, compound J075-4187 is a good candidate for use in developing antifungal agents for fungi control.

Rapid, Simultaneous Detection of Various Biological Toxin Genes Using Multiplex Reverse Transcription Loop-Mediated Isothermal Amplification(RT-LAMP) (다중 역전사-루프매개등온증폭법(RT-LAMP)를 이용한 생물 독소 유전자 신속 진단법)

  • Seungho Lee;Chanho Chung;Sehun Gu;Jungeun Kim;Hyeongseok Yun;Daesang Lee;Gyeunghaeng Hur;Donghyun Song
    • Journal of the Korea Institute of Military Science and Technology
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    • v.27 no.4
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    • pp.516-527
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    • 2024
  • Rapid, early, accurate detection and identification of the various pathogenic agents associated with the development of biological weapons is critical in preventing loss of life and limiting the impact of these organisms when used against civilian or military targets. The aim of this study was to produce a system for the simple, rapid, accurate and simultaneous detection and identification of Ricin, Botulinum toxin B and Staphylococcal enterotoxin B as a proof of principle for developing field appropriate reverse transcription loop-mediated isothermal amplification systems for the accurate identification of potential biological threats. These systems were designed to facilitate the identification of potential threats even in remote or resource-limited locations.

A Multiagent System for Workflow-Based Bioinformatics Tool Integration

  • Sohn, Bong-Ki;Lee, Keon-Myung;Kim, Hak-Joon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.3 no.2
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    • pp.133-137
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    • 2003
  • Various bioinformatics tools for biological data processing have been developed and most of them are available in public. Most bioinformatics works are carried out by a composite application of those tools. Several integration approaches have been proposed for easy use of the tools. This paper proposes a new multi agent system to integrate bioinformatics tools in the perspective of workflow since the composite applications of tools can be regarded as workflows. For the easy integration, the proposed system employs wrapper agents for existing tools, uses XML-based messages in the inter-agent communication, and agents are supposed to extract necessary information from the received messages. This allows new tools to be easily added on the integration framework. The proposed method allows various control structures in workflow definition and provides the progress monitoring capability of the on-going workflows. In particular, agents in this system have the rule-based architecture which allows the defined rule set to be a special role agent. This feature provides fast and flexible agent development to aid in managing the complexity of bioinformatics application. This system has been partially implemented and has been proven to be a viable implementation for workflow-based bioinformatics tool integration.

A Numerical Study on the Effects of Drug Ejection Velocity on Endovascular Thrombolysis

  • Jeong Woo Won;Rhee Kyehan
    • Journal of Biomedical Engineering Research
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    • v.26 no.3
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    • pp.157-161
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    • 2005
  • Direct injection of a fibrinolytic agent to the intraarterial thrombosis may increase the effectiveness of thrombolysis by enhancing the permeation of thrombolytic agents into the blood clot. Permeation of fibrinolytic agents into a clot is influenced by the surface pressure, which is determined by the injection velocity of fibrinolytic agents. In order to calculate the pressure distribution on the clot surface for different jet velocities (1, 3, 5 m/sec) and nozzle arrangements (1, 9, 17 nozzles), computational fluid dynamic methods were used. Thrombolysis of a clot was mathematically modeled based on the pressure and lysis front velocity relationship. Direct injection of a thrombolytic agent increased the speed of thrombolysis significantly and the effectiveness was increased as the ejecting velocity increased. The nine nozzles model showed about $20\%$ increase of the lysed volume, and the one and seventeen nozzles models did not show significant differences. The wall shear stress decreased as the number of nozzles increased, and the wall shear stress in most vessel wall was lower than 25 Pa. The results implied that thrombolysis could be accelerated by direct injection of a drug with the moderate velocity without damaging the blood vessel wall.

New Radiolytic Cyclization Products, Phlorocyclin and Isophlorocyclin Exhibit Anti-inflammatory Effects in LPS-stimulated Macrophages

  • Tae Hoon Kim
    • Journal of Radiation Industry
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    • v.18 no.1
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    • pp.63-70
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    • 2024
  • Phlorocyclin (PC) and isophorocyclin (IPC) are rare benzofuran derivaitves obtained from the representive dihydrochalcone glucoside, phloridzin (PZ) and are a type of neolignan backbone with a potential anti-glycative agents. However, research related to the enhancement of biological functionallites to inflammation of the newly converted products is very limited. This research was directed with the purpose of discovery more effective anti-inflammatory agents in macrophages of newly radiolysis products PC and IPC. The anti-inflammatory capacities of the characterized products in RAW 264.7 and DH82 macrophages treated with lipopolysaccharide (LPS) to stimulate an inflammation response were examined. The pro-inflammatory factors such as prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), nitric oxide (NO), interleukin-6 (IL-6), and IL-10, without cytotoxicity in LPS-stimulated macrophages, were significantly inhibited after treatment with PC and IPC, when compared to PZ. Moreover, PC and IPC decreased the appearance of cyclooxygenase-2 (COX-2) and inducible NO synthase (iNOS) proteins in macrophages. The cyclization products modified by radiolysis showed the greatest anti-inflammatory effects in macrophage cells, indicating PC and IPC are a potential candidate for use in anti-inflammatory agents.