228 results on '"Yong Jung Kwon"'
Search Results
2. Ginger (Zingiber officinale) phytochemicals—gingerenone-A and shogaol inhibit SaHPPK: molecular docking, molecular dynamics simulations and in vitro approaches
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Shailima Rampogu, Ayoung Baek, Rajesh Goud Gajula, Amir Zeb, Rohit S. Bavi, Raj Kumar, Yongseong Kim, Yong Jung Kwon, and Keun Woo Lee
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Ginger phytochemicals ,6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase ,GOLD ,Shogaol ,Gingerenone-A ,MD simulations ,Therapeutics. Pharmacology ,RM1-950 ,Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
Abstract Background Antibiotic resistance is a defense mechanism, harbored by pathogens to survive under unfavorable conditions. Among several antibiotic resistant microbial consortium, Staphylococcus aureus is one of the most havoc microorganisms. Staphylococcus aureus encodes a unique enzyme 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (SaHPPK), against which, none of existing antibiotics have been reported. Methods Computational approaches have been instrumental in designing and discovering new drugs for several diseases. The present study highlights the impact of ginger phytochemicals on Staphylococcus aureus SaHPPK. Herein, we have retrieved eight ginger phytochemicals from published literature and investigated their inhibitory interactions with SaHPPK. To authenticate our work, the investigation proceeds considering the known antibiotics alongside the phytochemicals. Molecular docking was performed employing GOLD and CDOCKER. The compounds with the highest dock score from both the docking programmes were tested for their inhibitory capability in vitro. The binding conformations that were seated within the binding pocket showing strong interactions with the active sites residues rendered by highest dock score were forwarded towards the molecular dynamic (MD) simulation analysis. Results Based on molecular dock scores, molecular interaction with catalytic active residues and MD simulations studies, two ginger phytochemicals, gingerenone-A and shogaol have been proposed as candidate inhibitors against Staphylococcus aureus. They have demonstrated higher dock scores than the known antibiotics and have represented interactions with the key residues within the active site. Furthermore, these compounds have rendered considerable inhibitory activity when tested in vitro. Additionally, their superiority was corroborated by stable MD results conducted for 100 ns employing GROMACS package. Conclusions Finally, we suggest that gingerenone-A and shogaol may either be potential SaHPPK inhibitors or can be used as fundamental platforms for novel SaHPPK inhibitor development.
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- 2018
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3. Resistance to commonly used insecticides and phosphine fumigant in red palm weevil, Rhynchophorus ferrugineus (Olivier) in Pakistan.
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Waqas Wakil, Muhammad Yasin, Mirza Abdul Qayyum, Muhammad Usman Ghazanfar, Abdullah M Al-Sadi, Geoffrey O Bedford, and Yong Jung Kwon
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Medicine ,Science - Abstract
The red palm weevil Rhynchophorus ferrugineus (Olivier) is an important pest of date palms in many regions of the world. This paper reports the first survey of insecticide resistance in field populations of R. ferrugineus in Pakistan which were collected from seven date palm growing areas across Punjab and Khyber Pakhtunkhwa (KPK) provinces, Pakistan. The resistance was assessed by the diet incorporation method against the formulated commonly used chemical insecticides profenophos, imidacloprid, chlorpyrifos, cypermethrin, deltamethrin, spinosad, lambda-cyhalothrin and a fumigant phosphine. Elevated levels of resistance were recorded for cypermethrin, deltamethrin and phosphine after a long history of insecticide use in Pakistan. Resistance Ratios (RRs) were 63- to 79-fold for phosphine, 16- to 74-fold for cypermethrin, 13- to 58-fold for deltamethrin, 2.6- to 44-fold for profenophos, 3- to 24-fold for chlorpyrifos, 2- to 12-fold for lambda-cyhalothrin and 1- to 10-fold for spinosad compared to a susceptible control line. Resistant R. ferrugineus populations were mainly found in southern Punjab and to some extent in KPK. The populations from Bahawalpur, Vehari, Layyah and Dera Ghazi Khan were most resistant to chemical insecticides, while all populations exhibited high levels of resistance to phosphine. Of the eight agents tested, lower LC50 and LC90 values were recorded for spinosad and lambda-cyhalothrin. These results suggest that spinosad and lambda-cyhalothrin exhibit unique modes of action and given their better environmental profile, these two insecticides could be used in insecticide rotation or assist in phasing out the use of older insecticides. A changed pattern of both insecticides can be used sensibly be recommended without evidence of dose rates and frequencies used.
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- 2018
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4. Taxonomic Revision of the Leafhopper Genus Macropsis Lewis from Korea (Homoptera: Cicadellidae)
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Sang Jae Suh, Jin Hyung Kwon, and Yong Jung Kwon
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Male ,Cicadellidae ,Insecta ,Arthropoda ,biology ,Fauna ,Zoology ,Identification key ,Biodiversity ,biology.organism_classification ,Hemiptera ,Auchenorrhyncha ,Leafhopper ,Genus ,Republic of Korea ,Animalia ,Animals ,Ovipositor ,Female ,Animal Science and Zoology ,Taxonomy (biology) ,Ecology, Evolution, Behavior and Systematics ,Taxonomy - Abstract
Korean species of the genus Macropsis Lewis are revised taxonomically, primarily based on the abdominal apodemes, male genitalia, and 2nd valvulae of the female ovipositor. Previously only three species were erroneously recorded from Korea. Among them, Macropsis notata (Prohaska, 1923) was previously misidentified as Macropsis prasina (Boheman, 1852). Two other European species, Macropsis scutellata (Boheman, 1845) and Macropsis illota (Horváth, 1899), are removed from the list of Korean fauna based on the examination of previously identified specimens that revealed only superficial resemblance to allied species. As a result, a total of 7 species are recognized in this revision, including 2 species new to science. Descriptions and distributional data are provided for all the species. Illustrations of both male and female genitalic characters as well as apodeme structures are provided, and an identification key to species from Korea is also given.
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- 2021
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5. Aphid population abundance and pestiferous effect on various bean plant species
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Ramiz Uddin Miah, Abdul Mannan Akanda, Sang Jae Suh, Ruhul Amin, Ohseok Kwon, Mohsen Ara Sharmin, and Yong Jung Kwon
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Aphid ,Insect Science ,Botany ,Plant species ,Biology ,Aphis craccivora ,biology.organism_classification ,Population abundance - Published
- 2020
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6. Two-dimensional semiconducting covalent organic nanosheets for highly sensitive and stable NO2 sensing under humid conditions
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Hyeunseok Choi, Jin Kuen Park, Woo Chul Ko, Min-Sung Kim, Won Rae Kim, Young Kyu Jeong, Yong Jung Kwon, and Jeehun Jeong
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Materials science ,Renewable Energy, Sustainability and the Environment ,business.industry ,Oxide ,Humidity ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Contact angle ,chemistry.chemical_compound ,Adsorption ,Semiconductor ,Chemical engineering ,chemistry ,Covalent bond ,Desorption ,General Materials Science ,Relative humidity ,0210 nano-technology ,business - Abstract
Semiconductor metal oxide gas sensors do not provide selective and sensitive gas adsorption under humid conditions owing to the deactivation of active sites by environmental humidity, leading to inaccurate signals in practical applications. Therefore, it is essential to explore organic-based gas sensors that are highly stable against variations in humidity without loss of selectivity and sensitivity toward the target gas. Herein, we demonstrate that a gas sensor integrated with two-dimensional covalent organic nanosheets (CONs) can show highly sensitive and reliable NO2 sensing performance at high humidity levels. The CON-based sensor can selectively detect the target gas to the 20 ppb level, and is thermally stable up to 300 °C, which is much above the typical working temperature for NO2 sensing. More importantly, the relative humidity change from 0 to 87% neither affects the baseline resistance nor the gas response of the CON sensor; the initial gas response is almost constant in repeated NO2 adsorption/desorption tests. Such excellent sensing stability at high humidity levels is ascribed to the superhydrophobic nature of CONs originating from their strong covalent bonds and additional nitrogen–sulfur bonds in the networks as confirmed by water contact angle (135.4°) measurements and density functional theory calculations.
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- 2020
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7. Molecular dynamics simulation study of PTP1B with allosteric inhibitor and its application in receptor based pharmacophore modeling.
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Kavitha Bharatham, Nagakumar Bharatham, Yong Jung Kwon, and Keun Woo Lee
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- 2008
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8. REDD1 promotes obesity-induced metabolic dysfunction via atypical NF-κB activation
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Dong-Keon Lee, Taesam Kim, Junyoung Byeon, Minsik Park, Suji Kim, Joohwan Kim, Seunghwan Choi, Gihwan Lee, Chanin Park, Keun Woo Lee, Yong Jung Kwon, Jeong-Hyung Lee, Young-Guen Kwon, and Young-Myeong Kim
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Inflammation ,Fatty Liver ,Mice ,Multidisciplinary ,NF-KappaB Inhibitor alpha ,NF-kappa B ,General Physics and Astronomy ,Animals ,Cytokines ,General Chemistry ,Obesity ,Amino Acids ,General Biochemistry, Genetics and Molecular Biology - Abstract
Regulated in development and DNA damage response 1 (REDD1) expression is upregulated in response to metabolic imbalance and obesity. However, its role in obesity-associated complications is unclear. Here, we demonstrate that the REDD1–NF-κB axis is crucial for metabolic inflammation and dysregulation. Mice lacking Redd1 in the whole body or adipocytes exhibited restrained diet-induced obesity, inflammation, insulin resistance, and hepatic steatosis. Myeloid Redd1-deficient mice showed similar results, without restrained obesity and hepatic steatosis. Redd1-deficient adipose-derived stem cells lost their potential to differentiate into adipocytes; however, REDD1 overexpression stimulated preadipocyte differentiation and proinflammatory cytokine expression through atypical IKK-independent NF-κB activation by sequestering IκBα from the NF-κB/IκBα complex. REDD1 with mutated Lys219/220Ala, key amino acid residues for IκBα binding, could not stimulate NF-κB activation, adipogenesis, and inflammation in vitro and prevented obesity-related phenotypes in knock-in mice. The REDD1-atypical NF-κB activation axis is a therapeutic target for obesity, meta-inflammation, and metabolic complications.
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- 2021
9. A global-scale expert assessment of drivers and risks associated with pollinator decline
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Jiandong An, Tom D. Breeze, Anikó Kovács-Hostyánszki, Hien T. Ngo, Simon G. Potts, Marcelo A. Aizen, Leonardo Galetto, Barbara Gemmill-Herren, Brad G. Howlett, Damayanti Buchori, Lynn V. Dicks, Thingreipi Lungharwo, Yong Jung Kwon, Deepa Senapathi, Colleen L. Seymour, Steven D. Johnson, H. Michael G. Lattorff, Adam J. Vanbergen, Parthiba Basu, Lucas Alejandro Garibaldi, Vera Lúcia Imperatriz-Fonseca, Conservation Science Group, Department of Zoology, University of Cambridge, Cambridge, UK, School of Biological Sciences, University of East Anglia, Norwich, UK, Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, Reading University, Reading, UK, IPBES Secretariat, Bonn, Germany, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, China, Instituto de Investigaciones en Biodiversidad y Medioambiente (INIBIOMA), Universidad Nacional del Comahue-CONICET, San Carlos de Bariloche, Rio Negro, Argentina, Department of Zoology, University of Calcutta, Kolkata, India, Center for Transdisciplinary and Sustainability Sciences, IPB University, Jalan Pajajaran, Indonesia, Department of Plant Protection, IPB University, Bogor, Indonesia, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad de Córdoba, Córdoba, Argentina, Instituto Multidisciplinario de Biología Vegetal, CONICET-UNC, Córdoba, Argentina, Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural (IRNAD), Universidad Nacional de Río Negro, El Bolsón, Argentina, Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural, Consejo Nacional de Investigaciones Científicas y Técnicas, Río Negro, Argentina, World Agroforestry Centre, Nairobi, Kenya, The New Zealand Institute for Plant & Food Research Limited, Lincoln, New Zealand, Biosciences Institute, University of Sao Paulo, São Paulo, Brazil, Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa, Institute of Ecology and Botany, Centre for Ecological Research, Vácrátót, Hungary, School of Applied Biosciences, Kyungpook National University, Daegu, Korea, International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya, Naga Women’s Union, Manipur, India, South African National Biodiversity Institute (SANBI), Kirstenbosch Research Centre, Claremont, South Africa, Department of Biological Sciences, FitzPatrick Institute, University of Cape Town, Rondebosch, South Africa, Agroécologie [Dijon], Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Dicks, Lynn V [0000-0002-8304-4468], Ngo, Hien T [0000-0003-3070-9988], Senapathi, Deepa [0000-0002-8883-1583], An, Jiandong [0000-0002-4203-4554], Aizen, Marcelo A [0000-0001-9079-9749], Basu, Parthiba [0000-0002-8942-0161], Galetto, Leonardo [0000-0003-3828-657X], Garibaldi, Lucas A [0000-0003-0725-4049], Imperatriz-Fonseca, Vera L [0000-0002-1079-2158], Lattorff, H Michael G [0000-0002-8603-6332], Seymour, Colleen L [0000-0002-6729-2576], Potts, Simon G [0000-0002-2045-980X], and Apollo - University of Cambridge Repository
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0106 biological sciences ,Crops, Agricultural ,Conservation Biology ,Natural resource economics ,media_common.quotation_subject ,Land management ,Agricultura (General) ,010603 evolutionary biology ,01 natural sciences ,Ecosystem services ,03 medical and health sciences ,Pollinator ,Biodiversidad y Conservación ,Humans ,Pesticides ,Pollination ,Ecosystem Services ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,media_common ,2. Zero hunger ,0303 health sciences ,Ecology ,Expert elicitation ,Biodiversity ,Ecología ,15. Life on land ,Pollinator decline ,Uncertainty ,Europe ,Geography ,13. Climate action ,Scale (social sciences) ,North America ,[SDE]Environmental Sciences ,Conservation biology ,Agroecology - Abstract
Fil: Dicks, Lynn V. University of Cambridge. Department of Zoology. Reino Unido. Fil: Breeze, Tom D. Reading University. School of Agriculture, Policy and Development. Centre for Agri-Environmental Research. Reino Unido. Fil: Ngo, Hien T. IPBES Secretariat. Alemania. Fil: Senapathi, Deepa. Reading University. School of Agriculture, Policy and Development. Centre for Agri-Environmental Research. Reino Unido. Fil: An, Jiandong. Chinese Academy of Agricultural Sciences. Institute of Apicultural Research. China. Fil: Aizen, Marcelo A. Universidad Nacional del Comahue. Instituto de Investigaciones en Biodiversidad y Medioambiente. Río Negro, Argentina. Fil: Basu, Parthiba. University of Calcutta. Department of Zoology. India. Fil: Buchori, Damayanti. IPB University. Center for Transdisciplinary and Sustainability Sciences. Indonesia. Fil: Galetto, Leonardo. Universidad de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Córdoba, Argentina. Fil: Garibaldi, Lucas A. Universidad Nacional de Río Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. Río Negro, Argentina. Fil: Garibaldi, Lucas A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. Río Negro, Argentina. Fil: Gemmill-Herren, Barbara. World Agroforestry Centre. Kenia. Fil: Howlett, Brad G. The New Zealand Institute for Plant & Food Research Limited. Nueva Zelanda. Fil: Imperatriz-Fonseca, Vera L. University of Sao Paulo. Biosciences Institute. Brasil Fil: Johnson, Steven D. University of KwaZulu-Natal. School of Life Sciences. Centre for Functional Biodiversity. Sudáfrica. Fil: Kovács-Hostyánszki, Anikó. Centre for Ecological Research. Institute of Ecology and Botany. Hungría. Fil: Jung Kwon, Yong. Kyungpook National University. School of Applied Biosciences. Corea del Sur. Fil: Lattorff, H. Michael G. International Centre of Insect Physiology and Ecology. Kenia. Fil: Lungharwo, Thingreipi. Naga Women’s Union. India. Fil: Seymour, Colleen L. Kirstenbosch Research Centre. South African National Biodiversity Institute. Sudáfrica. Fil: Vanbergen, Adam J. University of Bourgogne Franche-Comté. Francia. Fil: Potts, Simon G. Reading University. School of Agriculture, Policy and Development.Centre for Agri-Environmental Research. Reino Unido. Pollinator decline has attracted global attention and substantial efforts are underway to respond through national pollinator strategies and action plans. These policy responses require clarity on what is driving pollinator decline and what risks it generates for society in different parts of the world. Using a formal expert elicitation process, we evaluated the relative regional and global importance of eight drivers of pollinator decline and ten consequent risks to human well-being. Our results indicate that global policy responses should focus on reducing pressure from changes in land cover and configuration, land management and pesticides, as these were considered very important drivers in most regions. We quantify how the importance of drivers and risks from pollinator decline, differ among regions. For example, losing access to managed pollinators was considered a serious risk only for people in North America, whereas yield instability in pollinator-dependent crops was classed as a serious or high risk in four regions but only a moderate risk in Europe and North America. Overall, perceived risks were substantially higher in the Global South. Despite extensive research on pollinator decline, our analysis reveals considerable scientific uncertainty about what this means for human society.
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- 2021
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10. Catalyst and substrate-free synthesis of graphene nanosheets by unzipping C60 fullerene clusters using a pulse current method
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Ali Mirzaei, Wansik Oum, Heon Ham, Yong Jung Kwon, Sareh Mosleh-Shirazi, Ka Yoon Shin, Dong Jae Yu, Suk Woo Kang, Eun Bi Kim, Sang Sub Kim, and Hyoun Woo Kim
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Condensed Matter Physics - Published
- 2022
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11. Synergistic approach to simultaneously improve response and humidity-independence of metal-oxide gas sensors
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Jieon Lee, Kim Kyung Min, Yong Jung Kwon, Jin Kuen Park, Hyeunseok Choi, Young Kyu Jeong, Seung-Min Yang, and Jung-Hoon Lee
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Detection limit ,Environmental Engineering ,Materials science ,business.industry ,Health, Toxicology and Mutagenesis ,Drop (liquid) ,Oxide ,Humidity ,Nanoparticle ,chemistry.chemical_element ,Yttrium ,Pollution ,symbols.namesake ,chemistry.chemical_compound ,chemistry ,symbols ,Environmental Chemistry ,Optoelectronics ,Relative humidity ,van der Waals force ,business ,Waste Management and Disposal - Abstract
The chemiresistive response of metal-oxide gas sensors depends on ambient conditions. Humidity is a strongly influential parameter and causes large deviations in signals and, consequently, an inaccurate detection of target gases. Developing sensors unaffected by humidity, as documented by extensive works of research, comes at the cost of response — a significant drop in sensor response inevitably accompanies an increase in humidity-independence. This trade-off between humidity-independence and gas response is one of the major obstacles that limit practical applications of metal-oxide gas sensors. This study presents a novel approach to improve both the features by incorporating the rare-earth element, yttrium, into the host SnO2 sensor. The Y-doped SnO2 nanofibers are highly stable across relative humidity values ranging from 0% to 87%, and show improved selectivity and sensitivity in the detection of up to 20 ppb of NO2 target gas with the limit of detection at 103.71 ppt. Based on experimental results and van der Waals (vdW)-corrected DFT calculations, these improvements can be attributed to the synergistic effect of oxygen vacancy created by the introduction of aliovalent Y and the formation of Y2O3 nanoparticles that play a critical role in making the sensor surface hydrophobic.
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- 2021
12. Development of Web-Based Cognitive Training Program : Preliminary Study
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Jungeun Kim, Jun Ki Lee, Siekyeong Kim, Hyemi Park, and Yong-Jung Kwon
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business.industry ,Applied psychology ,medicine ,Dementia ,Web application ,Program development ,medicine.disease ,business ,Psychology ,Cognitive training - Published
- 2019
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13. Selective H2S-sensing performance of Si nanowires through the formation of ZnO shells with Au functionalization
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Wansik Oum, Jae Hoon Bang, Sang Sub Kim, Yong Jung Kwon, Sun Woo Choi, Ali Mirzaei, Myung Sik Choi, Hyoun Woo Kim, and Jae-Hun Kim
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Materials science ,Thin layer ,Metals and Alloys ,Nanowire ,Nanoparticle ,Heterojunction ,02 engineering and technology ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Chemical engineering ,Coating ,Materials Chemistry ,engineering ,Surface modification ,Oxidation process ,Electrical and Electronic Engineering ,0210 nano-technology ,Selectivity ,Instrumentation - Abstract
A novel gas sensor fabricated from ZnO-shelled Si nanowires (SiNWs) is presented. After coating a thin layer of Au on the surfaces of Si NWs, ZnO layers were formed on the surfaces of p-SiNWs by thermal evaporation of Zn powders and a subsequent oxidation process. Microscopic analysis confirmed the successful formation of ZnO-Si core-shell NWs with Au nanoparticles present on the shell surface. The gas sensing performance of the gas sensor fabricated using the p-Si/n-ZnO core-shell NWs was evaluated for various gases. The sensor exhibited outstanding response and selectivity to H2S gas. The gas sensing mechanism was evaluated in detail and attributed to various factors, including the formation of ZnO/Si and Au/ZnO heterojunctions and the chemical attraction between ZnO and Au. The results demonstrate a new sensing material for H2S detection in various fields that can be easily incorporated into Si-based devices.
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- 2019
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14. Laser-engineered oxygen vacancies for improving the NO2 sensing performance of SnO2 nanowires
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Heechae Choi, Hyoun Woo Kim, Yong Ho Ko, Yong Jung Kwon, Woo Chul Ko, and Young Kyu Jeong
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Materials science ,Renewable Energy, Sustainability and the Environment ,business.industry ,Nanowire ,Pulsed laser irradiation ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Electron ,021001 nanoscience & nanotechnology ,Laser ,Oxygen ,law.invention ,Adsorption ,chemistry ,law ,Optoelectronics ,General Materials Science ,Density functional theory ,Irradiation ,0210 nano-technology ,business - Abstract
Methods for oxygen vacancy engineering usually require high-temperature heating processes, which are substantially time-consuming. Laser irradiation techniques are a viable alternative to conventional methods, as they enable room-temperature tuning of material functionality using a simple, swift, and inexpensive process. In this report, the effects of pulsed laser irradiation on the formation of oxygen vacancies and its positive relationship with the sensing performance of SnO2 have been investigated. Based on density functional theory calculations, we suggest that the formation of laser-induced bridging oxygen defects and the resulting excess electrons on the SnO2 surface change the surface orbital structures of the Sn atoms in a manner favorable for NO2 adsorption, thus playing a key role in improving its sensing performance.
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- 2019
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15. A remarkable microleafhopper genus Koreoneura gen. nov. and newly recorded genus of the tribe Dikraneurini from Korea (Homoptera: Cicadellidae: Typhlocybinae)
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Jin Hyung Kwon, Sang Jae Suh, Yong Jung Kwon, and Md. Shamim Hossain
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Cicadellidae ,Insecta ,biology ,Dikraneurini ,Arthropoda ,Coreana ,Biodiversity ,biology.organism_classification ,Tribe (biology) ,Classification ,Typhlocybinae ,Auchenorrhyncha ,Hemiptera ,Genus ,Botany ,Republic of Korea ,Key (lock) ,Animals ,Animalia ,Animal Science and Zoology ,Taxonomy (biology) ,Ecology, Evolution, Behavior and Systematics ,Taxonomy - Abstract
Koreoneura eunyeopae Hossain et J. Kwon gen. et sp. nov., the biggest microleafhopper from East Asia, dwelling on Cornus coreana, along with a newly recorded genus, Igutettix Matsumura, 1932 based on I. oculatus (Lindberg), 1928, are described and illustrated from Korea. A key to the genera and checklist of Korean dikraneurine species are provided.
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- 2021
16. Two-Dimensional calcium silicate nanosheets for trapping atmospheric water molecules in humidity-immune gas sensors
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Young Ju, Cho, Yong Jung, Kwon, Sunghwan, Jin, Hyeunseok, Choi, Jung-Hoon, Lee, Seung-Min, Yang, Sun-Woo, Choi, and Young Kyu, Jeong
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History ,Environmental Engineering ,Polymers and Plastics ,Health, Toxicology and Mutagenesis ,Environmental Chemistry ,Business and International Management ,Pollution ,Waste Management and Disposal ,Industrial and Manufacturing Engineering - Abstract
In humid conditions, water vapor can easily neutralize the surface active sites of metal oxide sensors, leading to a lowering in the sensitivity of the gas sensor and a resultant inaccurate signal in practical applications. Herein, we present a new hybrid sensor by introducing a two-dimensional calcium silicate (CS) nanosheet as a water-trapping layer in SnO
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- 2022
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17. Proton-beam engineered surface-point defects for highly sensitive and reliable NO
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Jae Hoon, Bang, Yong Jung, Kwon, Jung-Hoon, Lee, Ali, Mirzaei, Ha Young, Lee, Hyeunseok, Choi, Sang Sub, Kim, Young Kyu, Jeong, and Hyoun Woo, Kim
- Abstract
Cross-interference with humidity is a major limiting factor for the accurate detection of target gases in semiconductor metal-oxide gas sensors. Under humid conditions, the surface-active sites of metal oxides for gas adsorption are easily deactivated by atmospheric water molecules. Thus, development of a new approach that can simultaneously improve the two inversely related features for realizing practical gas sensors is necessary. This paper presents a facile method to engineer surface-point defects based on proton-beam irradiation. The sensor irradiated with a proton beam shows not only an improved NO
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- 2020
18. A global assessment of drivers and risks associated with pollinator decline
- Author
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Marcelo A. Aizen, Hans Michael Lattorff, Lynn V. Dicks, Thingreipi Lungharwo, Jiandong An, Leonardo Galetto, Damayanti Buchori, Anikó Kovács-Hostyánszki, Lucas Alejandro Garibaldi, Hien T. Ngo, Simon G. Potts, Deepa Senapathi, Colleen L. Seymour, Brad G. Howlett, Parthiba Basu, Yong Jung Kwon, Adam J. Vanbergen, Vera Lúcia Imperatriz-Fonseca, Steven D. Johnson, Tom D. Breeze, and Barbara Gemmill-Herren
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Natural resource economics ,Biology ,Pollinator decline - Abstract
Pollinator decline has attracted global attention, and substantial efforts are underway to respond, through national pollinator strategies and action plans. These policy responses require clarity on what is driving pollinator decline, and what risks it generates for society, in different parts of the world. Using a formal expert elicitation process, we evaluated relative regional and global importance of eight pressures driving pollinator decline, and ten consequent risks to human well-being. Our results indicate that global policy responses should focus on reducing pressure from changes in land cover and configuration, land management, and pesticides, as these were considered very important drivers in most regions. We quantify for the first time how the importance of drivers, and risks from pollinator decline, differ among regions. For example, losing access to managed pollinators was only considered a serious risk to people in North America, whereas yield instability in pollinator-dependent crops, classed as a serious or high risk in four regions, presented only moderate risk in Europe and North America. Overall, perceived risks were substantially higher in the Global South. Despite extensive, research on pollinator decline, our analysis reveals considerable scientific uncertainty about what this means for human society.
- Published
- 2020
- Full Text
- View/download PDF
19. Taxonomic revision of the microleafhopper subgenus Alnetoidia Dlabola from Korea (Homoptera: Cicadellidae: Typhlocybinae)
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Sang Jae Suh, Yong Jung Kwon, Jin Hyung Kwon, and Md. Shamim Hossain
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Cicadellidae ,Insecta ,biology ,Arthropoda ,Fauna ,Homoptera ,Zoology ,Biodiversity ,biology.organism_classification ,Hemiptera ,Typhlocybinae ,Auchenorrhyncha ,Erythroneurini ,Republic of Korea ,Animals ,Animalia ,Animal Science and Zoology ,Taxonomy (biology) ,Subgenus ,Ecology, Evolution, Behavior and Systematics ,Taxonomy - Abstract
Four species of Alnetoidia Dlabola, 1958 s. str. are described and illustrated. Among them, Alnetoidia (Alnetoidia) jejudoensis sp. nov. is new to science and Alnetoidia (Alnetoidia) straminea Anufriev, 1972 is newly recorded for the Korean fauna. A key to the Korean species is provided.
- Published
- 2020
20. First record of the leafhopper genus Scaphomonus Viraktamath from Korea, with description of one new species (Hemiptera: Cicadellidae: Deltocephalinae)
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Nirmal Kumar Dutta, Jin Hyung Kwon, Sang Jae Suh, and Yong Jung Kwon
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China ,Cicadellidae ,Insecta ,Arthropoda ,biology ,Zoology ,Biodiversity ,Deltocephalinae ,biology.organism_classification ,Hemiptera ,Auchenorrhyncha ,Leafhopper ,Republic of Korea ,Animals ,Animalia ,Animal Science and Zoology ,Taxonomy (biology) ,Ecology, Evolution, Behavior and Systematics ,Taxonomy - Abstract
Dutta, Nirmal Kumar, Kwon, Jin Hyung, Suh, Sang Jae, Kwon, Yong Jung (2020): First record of the leafhopper genus Scaphomonus Viraktamath from Korea, with description of one new species (Hemiptera: Cicadellidae: Deltocephalinae). Zootaxa 4747 (1): 191-195, DOI: https://doi.org/10.11646/zootaxa.4747.1.9
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- 2020
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21. Selective NO2 sensor based on Bi2O3 branched SnO2 nanowires
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Hyoun Woo Kim, Ali Mirzaei, Yong Jung Kwon, Sang Sub Kim, Tae Whan Kim, Myung Sik Choi, and Jae Hoon Bang
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Materials science ,Fabrication ,Metals and Alloys ,Nanowire ,Heterojunction ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Branching (polymer chemistry) ,01 natural sciences ,Toluene ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Materials Chemistry ,Acetone ,Electrical and Electronic Engineering ,0210 nano-technology ,Selectivity ,Benzene ,Instrumentation - Abstract
We present a highly sensitive and selective NO2 sensor based on Bi2O3 branched SnO2 nanowires (NWs). SnO2 NWs were first synthesized by a vapor-liquid-solid method, were coated with an Au layer, and Bi2O3 branches were grown on their stems by the same procedure used for pure Bi powders. The fabricated sensor showed a high response (Rg/Ra) of 56.92 to 2 ppm of NO2 gas at an optimal temperature. Furthermore, its response to other interfering gases such as ethanol, acetone, toluene, and benzene, was less than 1.55, which demonstrated excellent selectivity of the sensor towards NO2 gas. For comparison and to better understand the sensing mechanism, a pristine SnO2 NWs sensor was also tested. The superior sensing properties of the branched NW sensor relative to the pristine sensor were mainly attributed to the high surface area of the sensor resulting from Bi2O3 branching, as well as the formation of homo-and heterojunctions (Bi2O3-SnO2). In addition, several factors including the presence of Au contributed to the excellent selectivity to NO2 gas. Based on the results obtained in this work, we believe that the present sensor with an easy fabrication method, along with its high sensitivity and selectivity towards NO2, can be used for the detection of NO2 gas in real applications.
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- 2018
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22. Effects of Domestic and Spanish Frozen Honeybee Pollens on the Colony Development of Large Earth Bumblebee, Bombus terrestris, in Korea
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Kyung Choi, Su Jin Lee, Sang Jae Suh, and Yong Jung Kwon
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biology ,Bombus terrestris ,Zoology ,Large earth bumblebee ,biology.organism_classification - Published
- 2018
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23. Plant material as an alternative tool for management of aphid in country bean field
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Sang Jae Suh, M. M. Hossain, M. R. U. Miah, M. T. Ahmed, Md. Ruhul Amin, and Yong Jung Kwon
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Aphid ,food ,biology ,Agronomy ,Lablab purpureus ,Insect Science ,biology.organism_classification ,Aphis craccivora ,Agronomy and Crop Science ,food.food - Abstract
The aphids Aphis craccivora Koch attack country bean Lablab purpureus L. both in its vegetative and reproductive stages and cause severe damage. To develop an integrated management of aphid...
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- 2018
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24. Dual sensitization of MWCNTs by co-decoration with p- and n-type metal oxide nanoparticles
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Ali Mirzaei, Sung Yong Kang, Jae Hoon Bang, Sang Sub Kim, Han Gil Na, Yong Jung Kwon, Hyoun Woo Kim, Sun Woo Choi, and Myung Sik Choi
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Materials science ,Oxide ,02 engineering and technology ,Carbon nanotube ,Metal oxide nanoparticles ,010402 general chemistry ,01 natural sciences ,law.invention ,Metal ,chemistry.chemical_compound ,law ,Sputtering ,Materials Chemistry ,Electrical and Electronic Engineering ,Instrumentation ,Deposition (law) ,Metals and Alloys ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Chemical engineering ,chemistry ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Selectivity ,Layer (electronics) - Abstract
We present a dual sensitization gas sensor for selective detection of either H2S or C2H5OH gases, based on ZnO/CuO nanoparticle (NP)-decorated MWCNTs. First, Cu-Zn layers of three different thickness (3, 6, 9 nm) were successfully deposited on the surfaces of CNTs by a sputtering process and subsequently converted to their corresponding oxides by thermal annealing. The gas sensing characteristics of metal oxide decorated-MWCNTs were studied in the presence of three gases, namely NO2, H2S, and C2H5OH. The best sensing properties were obtained when the Cu-Zn deposition layer was 6 nm thick. The optimized sensor showed extraordinary responses to both H2S and C2H5OH gases at working temperatures of 100 °C and 200 °C, respectively. Therefore, selectivity was tuned by selection of the working temperature. The sensing mechanisms of the metal oxide-decorated CNTs sensors are discussed in detail. The approach described, namely co-decoration of the surfaces of MWCNTs with different metal oxides, will be of great utility to researchers who wish to fabricate dual sensitive gas sensors.
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- 2018
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25. Identification of Novel Human HDAC8 Inhibitors by Pharmacophore-based Virtual Screening and Density Functional Theory Approaches
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Songmi Kim, Phil Kyeong Heo, Keun Woo Lee, Seokmin Kim, Siu Kim, Yuno Lee, Sang Jik Lee, and Yong Jung Kwon
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0301 basic medicine ,Virtual screening ,Chemistry ,HDAC8 ,General Chemistry ,Computational biology ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,030220 oncology & carcinogenesis ,Density functional theory ,Identification (biology) ,Histone deacetylase ,Pharmacophore - Published
- 2018
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26. Fabrication and gas sensing properties of vertically aligned Si nanowires
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Yong Jung Kwon, Sun Woo Choi, Ali Mirzaei, Myung Sik Choi, Jae Hoon Bang, Sang Sub Kim, Sung Yong Kang, and Hyoun Woo Kim
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Fabrication ,Materials science ,Aqueous solution ,Silicon ,Nanowire ,General Physics and Astronomy ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Isotropic etching ,Silver nanoparticle ,0104 chemical sciences ,Surfaces, Coatings and Films ,chemistry ,Etching (microfabrication) ,Electrode ,0210 nano-technology - Abstract
In this study, a peculiar configuration for a gas sensor consisting of vertically aligned silicon nanowires (VA-Si NWs) synthesized by metal-assisted chemical etching (MACE) is reported. Si NWs were prepared via a facile MACE method and subsequent thermal annealing. Etching was performed by generation of silver nanoparticles (Ag NPs) and subsequent etching in HF/H2O2 aqueous solution; the growth conditions were optimized by changing the process parameters. Highly vertically oriented arrays of Si NWs with a straight-line morphology were obtained, and a top–top electrode configuration was applied. The VA-Si NW gas sensor showed good sensing performance, and the VA-Si NWs exhibited a remarkable response (Rg/Ra = 11.5 ∼ 17.1) to H2 gas (10–50 ppm) at 100 °C which was the optimal working temperature. The formation mechanism and gas sensing mechanism of VA-Si NWs are described. The obtained results can suggest new approaches to making inexpensive, versatile, and portable sensors based on Si NWs having a novel top–top electrode structure that are fully compatible with well-developed Si technologies.
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- 2018
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27. Author Correction: A global-scale expert assessment of drivers and risks associated with pollinator decline
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Adam J. Vanbergen, Brad G. Howlett, Lynn V. Dicks, Yong Jung Kwon, Vera Lúcia Imperatriz-Fonseca, Tom D. Breeze, Jiandong An, Parthiba Basu, Steven D. Johnson, Lucas Alejandro Garibaldi, Damayanti Buchori, Hien T. Ngo, Simon G. Potts, Thingreipi Lungharwo, Barbara Gemmill-Herren, Leonardo Galetto, Deepa Senapathi, Colleen L. Seymour, Anikó Kovács-Hostyánszki, Marcelo A. Aizen, and H. Michael G. Lattorff
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Geography ,Ecology ,Scale (ratio) ,business.industry ,Environmental resource management ,business ,Ecology, Evolution, Behavior and Systematics ,Pollinator decline - Published
- 2021
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28. Proton-beam engineered surface-point defects for highly sensitive and reliable NO2 sensing under humid environments
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Hyoun Woo Kim, Ha Young Lee, Ali Mirzaei, Jung-Hoon Lee, Yong Jung Kwon, Jae Hoon Bang, Young Kyu Jeong, Sang Sub Kim, and Hyeunseok Choi
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021110 strategic, defence & security studies ,Environmental Engineering ,Materials science ,Proton ,business.industry ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,Humidity ,02 engineering and technology ,010501 environmental sciences ,Interference (wave propagation) ,01 natural sciences ,Pollution ,Crystallographic defect ,Semiconductor ,Adsorption ,Environmental Chemistry ,Optoelectronics ,Irradiation ,business ,Waste Management and Disposal ,Beam (structure) ,0105 earth and related environmental sciences - Abstract
Cross-interference with humidity is a major limiting factor for the accurate detection of target gases in semiconductor metal-oxide gas sensors. Under humid conditions, the surface-active sites of metal oxides for gas adsorption are easily deactivated by atmospheric water molecules. Thus, development of a new approach that can simultaneously improve the two inversely related features for realizing practical gas sensors is necessary. This paper presents a facile method to engineer surface-point defects based on proton-beam irradiation. The sensor irradiated with a proton beam shows not only an improved NO2 response but also considerable tolerance toward humidity. Based on surface analyses and DFT calculations, it is found that proton beams induce three types of point defects, which make NO2 molecules preferentially adsorb on the ZnO surfaces compared to H2O molecules, eventually enabling improved NO2 detection with less humidity interference.
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- 2021
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29. Taxonomy of the genus Atherigona Rondani (Diptera: Muscidae) from Korea
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Sang Jae Suh and Yong Jung Kwon
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0106 biological sciences ,Insect Science ,Muscidae ,010607 zoology ,Zoology ,Taxonomy (biology) ,Biology ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences - Published
- 2017
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30. Effect of some new generation insecticides on the population abundance of aphid and different beneficial insects in mustard crop
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MA Sarkar, SN Alam, Akmz Rahman, Yong Jung Kwon, and NK Dutta
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education.field_of_study ,Aphid ,biology ,Population ,Clothianidin ,biology.organism_classification ,Twig ,Population abundance ,Crop ,chemistry.chemical_compound ,Horticulture ,chemistry ,Botany ,General Earth and Planetary Sciences ,Beneficial insects ,Fenpropathrin ,education ,General Environmental Science - Abstract
The present study evaluated the efficacy of some new generation insecticides namely Clothianidin 48 SC, Fenpyroximate 5 SC, Pyridaben 20 WP and Methoxyphenozide 24 SC along with a synthetic pyrethroid insecticide, Fenpropathrin 20 EC against mustard aphid and their effects on beneficial insects i.e. syrphid flies and foraging honeybees during 2015 - 2016 in Bangladesh Agricultural Research Institute, Gazipur, Bangladesh. Tested six treatments were: Clothianidin 48 SC 1ml l-1, Fenpyroximate 5 SC 0.25 ml l-1, Pyridaben 20 WP 1g l-1, Methoxyphenozide 24 SC 1ml l-1 , Fenpropathrin 20 EC 1ml l-1 and an untreated control, replicated three times in RCBD. It was found that, Methoxyphenozide 24 SC was found to be the most effective against aphid offering lower aphid population (1.42/ top 10 cm central twig) at 7 days after spraying (DAS) which was statistically identical to Clothianidin 48 SC (1.50/top 10 cm central twig). Among the insecticides, Methoxyphenozide 24 SC was also found to be safer to the populations of syrphid flies revealing flight activity of 6.85 adults (plot/5 min) and honeybees of 8.82 workers (plot/5 min), respectively at 7 DAS. Whereas, Clothianidin 48 SC and Pyridaben 25 WP treated plots were found to be highly toxic to these beneficial insects. Consequently, the highest yield was obtained from Methoxyphenozide 24 SC (1.55 t/ha) followed by Fenpyroximate 5 SC (1.42 t/ha) treated plots.Bangladesh J. Agril. Res. 42(3): 563-570, September 2017
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- 2017
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31. Management of brinjal shoot and fruit borer leucinodes orbonalis guenee using different approaches
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Mah Chowdhury, Yong Jung Kwon, Sang Jae Suh, Hossain, and MZ Alam
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biology ,Spinosad ,Beauveria bassiana ,Leucinodes orbonalis ,Bassiana ,biology.organism_classification ,medicine.disease_cause ,chemistry.chemical_compound ,Horticulture ,Azadirachtin ,chemistry ,Shoot ,Infestation ,Botany ,medicine ,Abamectin ,General Earth and Planetary Sciences ,General Environmental Science ,medicine.drug - Abstract
The present study was conducted during October 2014 to June 2015 in the farm of Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur to find out the most effective management option (s) against brinjal shoot and fruit borer (BSFB) with 6 treatments namely, Beauveria bassiana , 1´109 CFU @ g l -1 , Bioneem 0.3 EC (Azadirachtin) @ 1.5 ml l -1 , Tracer 45 SC (Spinosad) @ 0.4 ml l -1 , Vertimec 1.8 EC (Abamectin) @ 1.2 ml l -1 of water, Mechanical control (hand picking) with clean cultivation and untreated control. Results revealed that shoot infestation at pre-fruiting stage was the lowest in Bioneem 0.3 EC (4.34%) and at fruiting stage in Tracer 45 SC treated plot (7.75%) and the highest was in untreated control plot (17.94% at pre-fruiting stage and 39.46 at fruiting stage). The lowest fruit infestation by BSFB was obtained with Tracer 45 SC (8.16% n/n and 10.0% w/w) followed by B. bassiana , 1´109 CFU (23.23% n/n and 18.27% w/w) and the highest infestation was observed under untreated control plot (48.59% n/n and 32.09% w/w). Percent reduction of infested fruit by number (83.21%) and weight (68.84%) over untreated control was higher in Tracer 45 SC treated plot resulting significantly higher marketable yield. Therefore, the significant highest marketable yield (34.39 t ha -1 ) was harvested in the plot treated with Tracer 45 SC followed by 22.78 t ha -1 with B. bassiana , 1´109 CFU and 19.26 t ha -1 from Vertimec 1.8 EC treated plot. The highest benefit cost ratio of 3.05 was obtained from Tracer 45 SC followed by 2.93 in B. bassiana , 1´109 CFU and 2.89 with Vertimec 1.8 EC sprayed plot. Bangladesh J. Agril. Res. 42(3): 539-548, September 2017
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- 2017
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32. First record of the quarantine pest Atherigona (Atherigona ) oryzae Malloch (Diptera: Muscidae) in Korea
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Sang Jae Suh and Yong Jung Kwon
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0106 biological sciences ,biology ,Introduced species ,Atherigona oryzae ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Invasive species ,law.invention ,010602 entomology ,law ,Insect Science ,Muscidae ,Botany ,Quarantine ,Plant quarantine ,PEST analysis - Published
- 2017
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33. Enhancement of gas sensing properties by the functionalization of ZnO-branched SnO2 nanowires with Cr2O3 nanoparticles
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Yong Jung Kwon, Sang Sub Kim, Sung Yong Kang, Jae Hoon Bang, Hyoun Woo Kim, Myung Sik Choi, and Ali Mirzaei
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Nanocomposite ,Materials science ,Scanning electron microscope ,Metals and Alloys ,Nanowire ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Transmission electron microscopy ,Materials Chemistry ,Surface modification ,Electrical and Electronic Engineering ,0210 nano-technology ,Selectivity ,Instrumentation ,Layer (electronics) - Abstract
Complex metal oxides such as functionalized branched nanowires (NWs) are a new category of nanocomposites with unique properties for gas sensing applications. In the present work, we studied the gas sensing properties of Cr 2 O 3 -functionalized ZnO-branched SnO 2 NWs, inspired by their high surface area and numerous resistive points. These NWs were studied and compared with pristine SnO 2 NWs and ZnO-branched SnO 2 NWs. To prepare the functionalized NWs, ZnO-branched SnO 2 NWs were sputter-coated with a Cr layer and then annealed at 500 °C to produce isolated Cr 2 O 3 NPs on the ZnO branches. Results of X-ray diffraction, scanning electron microscopy, and lattice-resolved transmission electron microscopy collectively showed that Cr 2 O 3 -functionalized ZnO-branched SnO 2 NWs were successfully formed. Cr 2 O 3 functionalization was found to greatly improve the sensors’ response to NO 2 gas. Furthermore, the sensors’ good selectivity was demonstrated by testing them in the presence of various interfering gases. The underlying gas sensing mechanisms are discussed herein in detail. We believe that the Cr 2 O 3 -functionalized ZnO-branched SnO 2 NWs reported herein are promising sensors for the highly sensitive and selective detection of NO 2 gas.
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- 2017
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34. Synthesis of zinc oxide semiconductors-graphene nanocomposites by microwave irradiation for application to gas sensors
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Jae Hoon Bang, Sang Sub Kim, Myung Sik Choi, Hyoun Woo Kim, Ali Mirzaei, Yong Jung Kwon, and Sung Yong Kang
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Materials science ,Cost effectiveness ,chemistry.chemical_element ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,Zinc ,010402 general chemistry ,01 natural sciences ,law.invention ,law ,Materials Chemistry ,Irradiation ,Electrical and Electronic Engineering ,Instrumentation ,Nanocomposite ,Graphene ,business.industry ,Metals and Alloys ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Semiconductor ,chemistry ,Chemical engineering ,0210 nano-technology ,business ,Microwave - Abstract
Microwave (MW) irradiation has obtained extensive importance in the field of synthesis and treatment of nanoparticles, because of its faster, cleaner and cost effectiveness than the other conventional and wet chemical methods. In this study, ZnO/graphene nanocomposites were prepared and subsequently post-treated by MW irradiation. Responses of the MW irradiated ZnO/graphene nanocomposites sensors were tested towards various gases including NO2, ethanol, acetone, toluene and CO and the results were compared with those of pristine ZnO and ZnO/graphene sensors without MW irradiation. It was demonstrated that the MW irradiated sensor had much higher response particularly to NO2 gas along with superior selectivity and shorter response/recovery times in comparison to unirradiated ZnO/graphene and pristine ZnO sensors. The possible underlying mechanism of this behavior is discussed in detail, mainly in terms of the MW-induced surface defects and the generation of finer ZnO nanoparticles. The results obtained demonstrated the beneficial effect of MW irradiation for enhancing the NO2-gas sensing behavior of ZnO/graphene nanocomposites, opening a new door not only to a novel synthesis of semiconductors/graphene nanocomposites, but also to a cost-effective way of improving their sensing capabilities.
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- 2017
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35. Microwave-Assisted Synthesis of Graphene–SnO2 Nanocomposites and Their Applications in Gas Sensors
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Han Gil Na, Myung Sik Choi, Jae Hoon Bang, Hyoun Woo Kim, Sang Sub Kim, Ping Wu, Sung Yong Kang, and Yong Jung Kwon
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Nanocomposite ,Materials science ,Graphene ,Microwave oven ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Evaporation (deposition) ,0104 chemical sciences ,law.invention ,Chemical engineering ,law ,Phase (matter) ,General Materials Science ,Atomic ratio ,0210 nano-technology ,Microwave - Abstract
We obtained extremely high and selective sensitivity to NO2 gas by fabricating graphene–SnO2 nanocomposites using a commercial microwave oven. Structural characterization revealed that the products corresponded to agglomerated structures of graphene and SnO2 particles, with small secondary SnOx (x ≤ 2) nanoparticles deposited on the surfaces. The overall oxygen atomic ratio was decreased with the appearance of an SnOx (x < 2) phase. By the microwave treatment of graphene–SnO2 nanocomposites, with the graphene promoting efficient transport of the microwave energy, evaporation and redeposition of SnOx nanoparticles were facilitated. The graphene–SnO2 nanocomposites exhibited a high sensor response of 24.7 for 1 ppm of NO2 gas, at an optimized temperature of 150 °C. The graphene–SnO2 nanocomposites were selectively sensitive to NO2 gas, in comparison with SO2, NH3, and ethanol gases. We suggest that the generation of SnOx nanoparticles and the SnOx phase in the matrix results in the formation of SnO2/SnO2 ho...
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- 2017
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36. Synthesis, characterization and gas sensing properties of ZnO-decorated MWCNTs
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Ali Mirzaei, Jae Hoon Bang, Hyoun Woo Kim, Yong Jung Kwon, Sang Sub Kim, Sung Yong Kang, and Myung Sik Choi
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Nanocomposite ,Materials science ,Oxide ,General Physics and Astronomy ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Characterization (materials science) ,law.invention ,chemistry.chemical_compound ,Zno nanoparticles ,chemistry ,law ,0210 nano-technology - Abstract
In this work, ZnO-decorated multi-walled carbon nanotube (MWCNT) nanocomposites prepared using an in-situ method involving the thermal evaporation of Zn powders in the presence of MWCNTs. The gas sensing characteristics of the MWCNT/ZnO nanocomposites are studied, and results for the material characterizations for the synthesized nanocomposites confirm the formation of well-distributed ZnO nanoparticles onto MWCNTs, creating MWCNT/ZnO nanocomposites. The gas sensing properties of the MWCNT/ZnO nanocomposite gas sensor, such as response, cross-sensitivity, and response-recovery time, are investigated and compared with a bare MWCNT sensor. The decoration of ZnO nanoparticles greatly improves the gas sensing properties of bare MWCNTs. We discussed the possible mechanisms for the enhancement of sensing capabilities. The results suggest that decoration of n-type semiconducting oxide materials, such as ZnO in the form of nanoparticles, is a promising strategy for improvement of gas sensing properties of p-MWCNTs.
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- 2017
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37. Three new species of the genus Kuvera Distant (Hemiptera: Fulgoromorpha: Cixiidae) from Korea
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Mohammad Atikur Rahman, Sang Jae Suh, and Yong Jung Kwon
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0106 biological sciences ,biology ,Insect Science ,Botany ,010607 zoology ,Taxonomy (biology) ,biology.organism_classification ,Cixiidae ,010603 evolutionary biology ,01 natural sciences ,Hemiptera ,Auchenorrhyncha - Abstract
Three new species of Kuvera Distant, 1906 (Hemiptera: Fulgoromorpha: Cixiidae: Cixiini), K. hagilsanensis sp. nov., K. hallasanensis sp. nov. and K. yecheonensis sp. nov., from Korea, are described...
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- 2017
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38. Enhancement of the benzene-sensing performance of Si nanowires through the incorporation of TeO2 heterointerfaces and Pd-sensitization
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Sang Sub Kim, Jae Hoon Bang, Sung Yong Kang, Hyoun Woo Kim, Sun-Woo Choi, Myung Sik Choi, and Yong Jung Kwon
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Imagination ,Chemical substance ,Materials science ,Silicon ,media_common.quotation_subject ,Nanowire ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Catalysis ,law.invention ,Magazine ,law ,Materials Chemistry ,Electrical and Electronic Engineering ,Instrumentation ,media_common ,business.industry ,Metals and Alloys ,Heterojunction ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Optoelectronics ,0210 nano-technology ,Science, technology and society ,business - Abstract
We report a novel method to significantly improve the C 6 H 6 -sensing performance of Si nanowires through the combination of TeO 2 branches and Pd sensitization. The morphological investigation revealed that TeO 2 branches were densely formed on the stem nanowires (NWs). The sensor responses of the Pd-functionalized branched NWs exhibited superior sensor responses of 55.19 to C 6 H 6 gas. In particular, Pd nanoparticles enhanced the sensor response to C 6 H 6 gas most efficiently, increasing the sensor response by 173.5%. Possible mechanisms for the sensing of the Pd-decorated branched nanowires will be associated with resistance modulation along the branch TeO 2 nanowires (including catalytic Pd effects), at the networked homojunctions between the branch TeO 2 nanowires, at the boundaries of the TeO 2 nanograins, and at the Pd/TeO 2 heterojunctions.
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- 2017
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39. Effect of temporal data aggregation on the perceived structure of a quantitative plant-floral visitor network
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Fawad Zafar Ahmad Khan, Mariano Devoto, Mudssar Ali, Yong Jung Kwon, Shafqat Saeed, and Asif Sajjad
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0106 biological sciences ,Ecology ,Visitor pattern ,Species diversity ,Biology ,010603 evolutionary biology ,01 natural sciences ,Temporal database ,Data aggregator ,Interaction network ,Insect Science ,Statistics ,Species evenness ,Nestedness ,Species richness ,010606 plant biology & botany - Abstract
Seasonal turnover in plant and floral visitor communities changes the structure of the network of interactions they are involved in. Despite the dynamic nature of plant–visitor networks, a usual procedure is to pool year-round interaction data into a single network which may result in a biased depiction of the real structure of the interaction network. The annual temporal dynamics and the effect of merging monthly data have previously been described for qualitative data (i.e. describing the occurrence of interactions) alone, while its quantitative aspect (i.e. the actual frequency with which interactions occur) remain little explored. For this, we built a set of 12 monthly networks describing year-round plant–floral visitor interactions in a 30-hectare planted forest and its adjacent agricultural landscape at Bahauddin Zakariya University Multan, Pakistan. A total of 80 plant and 162 insect species, which engaged in 1573 unique interactions, were recorded. Most network properties (particularly the number of plants, visitors and unique interactions) varied markedly during the year. Data aggregation showed that while animal species, plant species, unique interaction, weighted nestedness, interaction diversity and robustness increased, connectance and specialization decreased. The only metric which seemed relatively unaffected by data pooling was interaction evenness. In general, quantitative metrics were relatively less affected by temporal data aggregation than qualitative ones. Avoiding data aggregation not only gives a more realistic depiction of the dynamic nature of plant–visitor community networks, but also avoids biasing network metrics and, consequently, their expected response to disturbances such as the loss of species.
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- 2017
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40. Effect of leaf trichomes and meteorological parameters on population dynamics of aphid and jassid in cotton
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Yong Jung Kwon, MM Hossain, Mohammad Zahangeer Alam, Amin, and R Afrin
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0106 biological sciences ,0301 basic medicine ,Abiotic component ,education.field_of_study ,Aphid ,Maximum temperature ,biology ,Population ,Sowing ,biology.organism_classification ,01 natural sciences ,Trichome ,010602 entomology ,03 medical and health sciences ,Horticulture ,030104 developmental biology ,Agronomy ,Abundance (ecology) ,General Earth and Planetary Sciences ,Relative humidity ,education ,General Environmental Science - Abstract
This study was conducted with CB1, CB3, CB5, CB8 and C12 cotton varieties to determine the role of leaf trichomes and meteorological factors on the abundances of aphid and jassid. The mean population of the pests on the tested varieties differed significantly and showed negative correlation with trichomes. The pests were most abundant on CB12, and each variety revealed significantly higher population of jassid than that of aphid. Both the pests built up their population in the juvenile stage of the plants (73 days after sowing) and continued until harvesting. Aphid population was the highest on CB12 in the first week of November, whereas maximum abundance of jassid was on CB12 in the third week of December. Weather parameters were found insignificant on aphid abundance, but jassid population on the varieties was correlated with maximum and minimum temperatures, relative humidity and rainfall. Multiple regression equation based on weather parameters exerted 8.8 - 43.2% and 54.4 - 77.7% role on population build up of aphid and jassid, respectively. Maximum temperature had the most important effect which contributed 61.2% population fluctuation of jassid on CB12.Bangladesh J. Agril. Res. 42(1): 13-25, March 2017
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- 2017
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41. Effect of insecticides on population reduction of sucking insects and lady bird beetle in eggplant field
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M. Mahmudunnabi, SN Alam, Amin, NK Dutta, and Yong Jung Kwon
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education.field_of_study ,Aphid ,biology ,Thrips ,business.industry ,Population ,Pest control ,biology.organism_classification ,Population density ,Predation ,Toxicology ,chemistry.chemical_compound ,chemistry ,Imidacloprid ,Botany ,General Earth and Planetary Sciences ,education ,business ,Predator ,General Environmental Science - Abstract
This study evaluated the field efficacy of three newly introduced synthetic insecticides namely, Python 20SL (Nitenpyrum), Plenum 50WG (Pymetrozin), Polo 500SL (Diafentiuron) along with commonly used chemical Admire 200SL(Imidacloprid) against sucking insects of eggplant such as aphid, jassid, white fly and thrips. The effect of the insecticides on the population reduction of the novel predator lady bird beetle was also studied. Among the chemicals, Polo 500SC was found to be the most effective followed by Plenum 50WG against the sucking insects by reducing significant percentages of their population at 3 and 7 days after spray. Polo 500SC and Plenum 50WG were found to be the least deleterious against lady bird beetle since it caused lowest population reduction. Considering the higher percentages of population reduction of the pests and significantly lower affect on the predator, Polo 500SC and Plenum 50WG may be considered as a tool of IPM for management of sucking insects in the eggplant field.Bangladesh J. Agril. Res. 42(1): 35-42, March 2017
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- 2017
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42. Attachment of Co3O4 layer to SnO2 nanowires for enhanced gas sensing properties
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Tae Whan Kim, Ali Mirzaei, Hyoun Woo Kim, Jae Hoon Bang, Han Gil Na, Myung Sik Choi, Sung Yong Kang, and Yong Jung Kwon
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Imagination ,Materials science ,Chemical substance ,media_common.quotation_subject ,Nanowire ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,Magazine ,law ,Materials Chemistry ,Electrical and Electronic Engineering ,Vapor–liquid–solid method ,Instrumentation ,media_common ,Nanocomposite ,business.industry ,Metals and Alloys ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Optoelectronics ,0210 nano-technology ,business ,Science, technology and society ,Layer (electronics) - Abstract
We prepared nanocomposites of n-SnO2/p-Co3O4 for application in chemical sensors. In order to fabricate p-Co3O4-decorated n-SnO2 nanowires, we sputtered a Co layer and subsequently annealed the material in air ambient. Characterization revealed that crystalline cubic Co3O4 with a tubular-like structure was attached to the surface of SnO2 core nanowires. We carried out sensing tests at 573 K in at NO2 gas concentrations ranging between 2 and 10 ppm. The sensor response was increased both by adding the Co3O4 layer and also by decreasing the thickness of the Co3O4 layer from 19.2 to 6.4 nm. We proposed possible mechanisms to explain the enhanced sensor properties obtained by Co3O4-functionalization. Co3O4-functionalized SnO2 nanowires exhibited a higher sensor response than pristine nanowires, not only due to the heterostructure-induced depletion of n-SnO2 region but also due to the surface effects of Co3O4. The generation of hole-accumulated Co3O4 layer in case of thicker-layered nanowires will decrease the sensor response. We demonstrated that Co3O4-functionalized SnO2 nanowire sensors can be used as gas sensors at very low concentrations.
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- 2017
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43. Taxonomic revision of the microleafhopper genus Naratettix Matsumura (Homoptera: Cicadellidae: Typhlocybinae) from Korea
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Sang Jae Suh, Yong Jung Kwon, Jin Hyung Kwon, and Md. Shamim Hossain
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Cicadellidae ,Insecta ,Arthropoda ,biology ,Dikraneurini ,Homoptera ,Zoology ,Biodiversity ,biology.organism_classification ,Hemiptera ,Auchenorrhyncha ,Typhlocybinae ,Republic of Korea ,Animalia ,Animals ,Animal Science and Zoology ,Taxonomy (biology) ,Ecology, Evolution, Behavior and Systematics ,Taxonomy - Abstract
The genus Naratettix Matsumura, 1931 from Korea is revised. With the three previously recorded species, N. cheondungsanus sp. nov. is described as new to science, and N. ibukisanus Matsumura, 1931 is reported for the first time from Korea. Descriptions, illustrations and a key to the Korean Naratettix species are provided.
- Published
- 2019
44. Two new species and two newly recorded species of the subgenus Empoasca Walsh from Korea (Hemiptrea: Cicadellidae: Typhlocybinae)
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Sang Jae Suh, Yong Jung Kwon, Md. Shamim Hossain, and Jin Hyung Kwon
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Empoasca ,biology ,biology.organism_classification ,Hemiptera ,Typhlocybinae ,Auchenorrhyncha ,Botany ,Republic of Korea ,Animals ,Animal Science and Zoology ,Taxonomy (biology) ,Subgenus ,Ecology, Evolution, Behavior and Systematics - Abstract
Two new species of the subgenus Empoasca (Empoasca) Walsh 1862 from Korea are described: E. giusana sp. nov. and E. palgongsana sp. nov. The following two species are newly recorded from Korea: E. ishiharai Anufriev, 1973 and E. longa Zhang and Liu, 2011. A key and checklist of Korean species of this subgenus are also provided.
- Published
- 2019
45. Taxonomic revision of the microleafhopper genus Limassolla Dlabola from Korea (Hemiptrea: Cicadellidae: Typhlocybinae)
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Yong Jung Kwon, Sang Jae Suh, Shamim Hossain, and Jin Hyung Kwon
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0106 biological sciences ,Cicadellidae ,Insecta ,Arthropoda ,Fauna ,010607 zoology ,010603 evolutionary biology ,01 natural sciences ,Typhlocybinae ,Auchenorrhyncha ,Trees ,Hemiptera ,Botany ,Republic of Korea ,Animalia ,Animals ,Ecology, Evolution, Behavior and Systematics ,Taxonomy ,biology ,Diospyros kaki ,Biodiversity ,biology.organism_classification ,Key (lock) ,Animal Science and Zoology ,Taxonomy (biology) ,PEST analysis - Abstract
Four species belonging to the genus Limassolla Dlabola, 1965 from Korea are revised. Among them, L. koreana sp. nov., an occasional pest of persimmon trees (Diospyros kaki) is new to science. L. macrobipunctata Choe, 1986 (nom. nud.) is validated by providing a description and illustration, and L. multipunctata (Matsumura, 1920) is newly recorded for the Korean fauna. Descriptions, illustrations and a key to the Korean species are provided here.
- Published
- 2019
46. Surprising synthesis of nanodiamond from single-walled carbon nanotubes by the spark plasma sintering process
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Jae Hoon Bang, Heon Ham, Hyoun Woo Kim, Ali Mirzaei, Inpil Kang, Yong Jung Kwon, No-Hyung Park, Sung Yong Kang, Han Gil Na, and Myung Sik Choi
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Materials science ,Nucleation ,Spark plasma sintering ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,Carbon nanotube ,engineering.material ,01 natural sciences ,law.invention ,Condensed Matter::Materials Science ,symbols.namesake ,law ,Phase (matter) ,0103 physical sciences ,Physics::Atomic and Molecular Clusters ,Nanodiamond ,010302 applied physics ,Diamond ,021001 nanoscience & nanotechnology ,Electronic, Optical and Magnetic Materials ,Chemical engineering ,chemistry ,engineering ,symbols ,0210 nano-technology ,Raman spectroscopy ,Carbon - Abstract
Nanodiamond (ND) was successfully synthesized using single-walled carbon nanotubes (SWCNTs) as a pure solid carbon source by means of a spark plasma sintering process. Raman spectra and X-ray diffraction patterns revealed the generation of the cubic diamond phase by means of the SPS process. Lattice-resolved TEM images confirmed that diamond nanoparticles with a diameter of about ∼10 nm existed in the products. The NDs were generated mainly through the gas-phase nucleation of carbon atoms evaporated from the SWCNTs.
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- 2016
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47. Infestation of sucking insect pests on five cotton cultivars and their impacts on varietal agronomic traits, biochemical contents, yield and quality
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SJ Suh, Amin, Yong Jung Kwon, and R Afrin
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Aphid ,Lint ,biology ,Aphididae ,biology.organism_classification ,medicine.disease_cause ,Industrial and Manufacturing Engineering ,Trichome ,Agronomy ,Germination ,Aphis gossypii ,Infestation ,medicine ,Cultivar - Abstract
The five cotton cultivars viz., CB1, CB3, CB5, CB8, and C12 were evaluated under field conditions to compare their resistance levels against the aphid species Aphis gossypii (Hemiptera: Aphididae) and the jassid species Amrasca devastans (Hemiptera: Cicadellidae). The effects of plant characteristics that could explain some of the varietal resistance levels were tested by measuring infestation levels, biochemical content, leaf trichome density, agronomic traits, yield, and quality of seed and fiber. In comparison with other varieties, CB1 and CB3 showed the least leaf and boll infestation, and possessed higher numbers of trichomes. CB12 had the lowest number of trichomes and exhibited the highest percentages of leaf and boll infestation. Biochemical analyses indicated that the highest percentage of starch occurred in CB8, and that of protein in CB5. Both starch and protein content were lowest in CB12. Aphid and jassid infestation reduced the starch and protein content of all cultivars. CB3 was the best performing variety in terms of size and weight of bolls; ginning out-turn (GOT); number of branches, leaves, and bolls per plant; and number of locules per boll. Seed cotton yields and lint indices were highest in CB1 and CB3 and lowest in CB12. CB12 was also the worst performing variety in terms of plant height, micronaire value, percentage of GOT and germination, number of leaves and bolls per plant, and boll length, width and weight. The findings of this study clearly demonstrate that, among the cultivars evaluated, CB12 is the most susceptible to aphid and jassid infestation.SAARC J. Agri., 14(1): 11-23 (2016)
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- 2016
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48. QSAR modeling to design selective histone deacetylase 8 (HDAC8) inhibitors
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Keun Woo Lee, Yongseong Kim, Sundarapandian Thangapandian, Yeung-Joon Choi, Raj Kumar, Guang Ping Cao, Minky Son, Yong Jung Kwon, Jung-Keun Suh, and Hyong-Ha Kim
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0301 basic medicine ,Quantitative structure–activity relationship ,Databases, Factual ,Quantitative Structure-Activity Relationship ,Feature selection ,Computational biology ,Molecular Dynamics Simulation ,Histone Deacetylases ,Cross-validation ,03 medical and health sciences ,0302 clinical medicine ,Molecular descriptor ,Drug Discovery ,Humans ,Virtual screening ,Chemistry ,Organic Chemistry ,Matthews correlation coefficient ,Combinatorial chemistry ,Histone Deacetylase Inhibitors ,Repressor Proteins ,030104 developmental biology ,Drug Design ,030220 oncology & carcinogenesis ,Test set ,Molecular Medicine ,Chemical database - Abstract
HDAC8 inhibitors have become an attractive treatment for cancer. This study aimed to facilitate the identification of potential chemical scaffolds for the selective inhibition of histone deacetylase 8 (HDAC8) using in silico approaches. Non-linear QSAR classification and regression models of HDAC8 inhibitors were developed with support vector machine. Mean impact value-based sequential forward feature selection and grid search strategy were used for molecular descriptor selection and parameter optimization, respectively. The generated QSAR models were validated by leave-one-out cross validation and an external test set. The best QSAR classification model yielded 84 % of accuracy on the external test prediction and Matthews correlation coefficient is 0.69. The best QSAR regression model showed low root-mean-square error (0.63) and high squared correlation coefficient (0.53) for the test set. The validated QSAR models together with various drug-like properties, molecular docking and molecular dynamics simulation were sequentially used as a multi-step query in chemical database virtual screening. Finally, two hit compounds were discovered as new structural scaffolds which can be used for further in vitro and in vivo activity analyses. The strategy used in this study could be a promising computational strategy which can be utilized for other target drug design.
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- 2016
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49. Effect of weed extracts against pulse beetle, Callosobruchus chinensis L. (Coleoptera: Bruchidae) of mung bean
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Md. Ruhul Amin, Md. Abdul Ahad, Sang Jae Suh, Yong Jung Kwon, and M. K. Nahar
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0106 biological sciences ,Cassia tora ,biology ,ved/biology ,Radiata ,ved/biology.organism_classification_rank.species ,Fecundity ,biology.organism_classification ,01 natural sciences ,Croton ,Vigna ,010602 entomology ,Horticulture ,Agronomy ,General Earth and Planetary Sciences ,Grain damage ,Weed ,010606 plant biology & botany ,General Environmental Science ,Callosobruchus chinensis - Abstract
The n-hexane extracts of the weeds ‘bhatpata’ Clerodendrum viscosum, ‘kashiature’ Cassia tora, ‘dhakishak’ Dryoptris filix-max, ‘ bonmorich’ Croton bonpalandianum and ‘ghagra’ Xanthium strumarium were used to evaluate their effectiveness for suppressing pulse beetle, Callosobruchus chinensis reared on mung bean Vigna radiata grains . The investigations were done with 1, 2 and 4% n-hexane extracts of the weeds and an untreated control. The weed extracts exhibited considerable effectiveness which varied with weed species, concentrations and exposure durations. The higher concentrations showed the higher rate of insect mortality, fecundity, adult emergence inhibition, and grain protection. The LC 50 values of the extracts ranged from 5.3 to 7.8, 4.7 to 6.5 and 4.1 to 6.0 g/100 ml at 24, 48 and 72 hours after treatment, respectively. The fecundity inhibition varied from 31.7 to 78.7%, adult emergence inhibition from 33.8 to 81.1%, and grain damage inhibition from 10.3 to 60.1% when ‘bhatpata’ with concentration of 1 g/100 ml and ‘ghagra’ with concentration of 4g/100 ml were applied, respectively. Among the tested weeds, ghagra (4g/100 ml) showed better efficacy against C. chinensis compared to other tested extracts and may be suggested to control pulse beetle and protection of mung bean grains. Bangladesh J. Agril. Res. 41(1): 75-84, March 2016
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- 2016
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50. Selective detection of low concentration toluene gas using Pt-decorated carbon nanotubes sensors
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Hyoun Woo Kim, Yong Jung Kwon, Sung Yong Kang, Sang Sub Kim, Sun-Woo Choi, and Han Gil Na
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Materials science ,Composite number ,Metals and Alloys ,Nanotechnology ,02 engineering and technology ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Toluene ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,law ,Materials Chemistry ,Electrical and Electronic Engineering ,Pt nanoparticles ,0210 nano-technology ,Instrumentation ,Volume concentration - Abstract
We demonstrated the preparation of high-performance toluene (C7H8) gas sensor, by using the Pt-multiwalled carbon nanotubes (MWCNTs) composite materials. We optimized the size of the Pt nanoparticles by controlling the predeposited Pt thickness, for obtaining the highest sensing performances. We have obtained the sensor responses of 3.91 and 5.06, at concentrations of 1 and 5 ppm of C7H8 gas, respectively, at 150 °C. We discussed the associated sensing mechanisms and proposed the reasons why the Pt-functionalization drastically enhanced the sensing behaviors of the Pt-MWCNTs composite sensors selectively to C7H8 gas.
- Published
- 2016
- Full Text
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