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        검색결과 26

        1.
        2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, ester co-solvents and fluoroethylene carbonate (FEC) were used as low-temperature electrolyte additives to improve the formation of the solid electrolyte interface (SEI) on graphite anodes in lithium-ion batteries (LIBs). Four ester co-solvents, namely methyl acetate (MA), ethyl acetate, methyl propionate, and ethyl propionate, were mixed with 1.0 M LiPF6 ethylene carbonate:diethyl carbonate:dimethyl carbonate (1:1:1 by vol%) as the base electrolyte (BE). Different concentrations were used to compare the electrochemical performance of the LiCoO2/ graphite full cells. Among various ester co-solvents, the cell employing BE mixed with 30 vol% MA (BE/MA30) achieved the highest discharge capacity at − 20 °C. In contrast, mixing esters with low-molecular-weight degraded the cell performance owing to the unstable SEI formation on the graphite anodes. Therefore, FEC was added to BE/MA30 (BE/MA30-FEC5) to form a stable SEI layer on the graphite anode surface. The LiCoO2/ graphite cell using BE/MA30-FEC5 exhibited an excellent capacity of 127.3 mAh g− 1 at − 20 °C with a capacity retention of 80.6% after 100 cycles owing to the synergistic effect of MA and formation of a stable and uniform inorganic SEI layer by FEC decomposition reaction. The low-temperature electrolyte designed in this study may provide new guidelines for resolving low-temperature issues related to LIBs, graphite anodes, and SEI layers.
        4,500원
        11.
        2016.10 구독 인증기관·개인회원 무료
        Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne zoonosis and SFTS virus is transmitted to humans by tick bites. The aim of this study was to monitor tick population and its SFTS virus infection. During March 2014 to October 2015, ticks were monthly sampled using dry-ice bait trap and flag method from 4 collecting points in Boeun-gun. A total of 16,500 ticks, including 14,646 Haemaphysalis longicornis (88.7%), 1,825 H. flava (11.1%), and 29 Ixodes nipponensis (0.2%), were collected. Ticks were pooled (5,156 ticks in 456 pools) and tested by RT-PCR and nested PCR and the minimum infection rate of ticks was 0.27% (14 pools) consisting of 0.13% H. longicornis (6 pools), 1.19% H. flava (8 pools). This annual surveillance study will be needed for long-term monitoring of ixodid ticks in Korea.
        12.
        2016.10 구독 인증기관·개인회원 무료
        This study evaluated the physicochemical quality characteristics of raw and roasted beans of fully washed specialty Bourbon cultivar ofCoffea Arabica“BM 139" from seven of the major coffee growing areas in Rwanda in comparison with a wet processed Typica cultivar from Yirgacheffe, Ethiopia and a dry processed red Bourbon cultivar from Cerrado, Brazil. Tested samples had moisture content between 7.7 and10.2%. Raw coffee from Brazil had the lowest density and darker than samples from other regions. Other samples showed no significant differences in true density. Raw coffee from Kayumbu coffee washing station (CWS), Kamonyi district showed the lowest total phenolic content of 38.4 mg/g solid whereas raw coffee from Nyamyumba CWS, Rubavu district had the highest content of 46.8 mg/g solid. DPPH radical scavenging activity (RSA) ranged from 89.9 to 91.8% and varied little between samples. Raw coffee from Yirgacheffe, Ethiopia showed the highest total titratable acidity of 1.48% as citric acid and totalcaffeoylquinic acidof 82.62 mg/g solid whereas that from Brazil had the highest caffeine content of 18.5 mg/g solid. Raw coffee from Karenge CWS, Rwamagana district was characterized by having the lowest caffeine and trigonelline content (13.4 and 10.3 mg/g solid, respectively). After roasting, there was a drop in most physicochemical characteristics. Raw and roasted coffee samples from Rulindo and Kirorero CWS indicated higher bulk densities which might be due to higher altitudes of these two areas. Caffeine and RSA were not affected by the roasting process. The Brazilian coffee was characterized by higher caffeine content in raw as well as roasted forms. After roasting, coffees from Rwanda were more acidic than Brazilian and Ethiopian coffees. This study revealed that the physicochemical characteristics of the Bourbon cultivar may vary depending on the geographical sub-regions which is due to environmental conditions, processing and agricultural practices.
        14.
        2015.10 구독 인증기관·개인회원 무료
        Trombiculid mites are known to be the vector of scrub typhus by transmitting rickettsial pathogen, Orientia tsutsugamushi, to human. In this study, we tried to establish a monitoring system for trombiculid mites using chigger mite collecting traps instead of the conventional rodent-capture method. For selection of collecting points, 10 environmental points were chosen from three regions (Taean, Jinan and Chungju) and two field collections were performed in spring (March-May) and autumn (October-November) seasons from 2013 to 2014. Among 10 environmental points, waterway (37.9%), grass field (28.0%), rice field and field near mountain side (11.4%) and reservoir/wet field (7.3%) showed high collecting rates and they should be included for the representative collecting points for surveillance using chigger mite collecting trap. In order to test the possibility that the dried chigger mites from collecting trap can be used for detection of O. tsutsugamushi, we pooled 30, 10 and 5 chigger mites separately and performed the nested PCR. The infection of O. tsutsugamushi was successfully detected from 5 chigger mites pooling sample. This study shows that chigger mite collecting trap could be an alternative method for monitoring system of scrub typhus vectors.
        15.
        2015.10 구독 인증기관·개인회원 무료
        There are over 3,000 different species of mosquitoes throughout the world; currently 56 species are reported in Korea. Mosquitoes can act as vectors for many disease-causing viruses and parasites during blood sucking. Various species of mosquitoes are estimated to transmit various types of disease to more than 700 million people annually in Africa, South America, Central America, Mexico, Russia, and much of Asia, with millions of resultant deaths. At least two million people annually die of these diseases, and the morbidity rates are many times higher still. To prevent the spread of diseases, KNIH (Korea National Institute of Health) used three categorized methods; identifying or taxonomic analysis of mosquitoes, detecting virus caring mosquitoes, and detecting malaria from Anopheline mosquitoes. We have proved that taxonomic analysis using DNA barcording method (COI gene) is useful to complement identification of mosquito species. In detecting virus, we have reported Cx. orientalis as a new potential Japanese encephalitis virus (JEV) vector. We also reported that the Anopheline mosquito species composition and Plasmodium vivax infection rates in malaria hot spot in Korea.
        16.
        2013.05 구독 인증기관·개인회원 무료
        A total of 35 phosphate solubilizing bacterial strains were isolated from waste bed of Agaricus bisporus in Buyeo-Gun, Chungchugnam-do province and screened for the production of indole acetic acid(IAA). The best IAA producing strain was identified as Pantoea rodasii using 16S rRNA analysis. In addition to the IAA production, this strain could act as an efficient phosphate solubilizer (1100 μg ml-1 after 5 days of incubation) also. The selected strain was cultured under different conditions in order to assess the optimum conditions for maximum IAA production. The nutrient broth (NB) medium was recorded as the best medium, where the maximum IAA production (229 μg ml-1) was recorded at the start of stationary phase (12 hours after inoculation) of the bacteria growth. The performance of the strain was found to be maximum at the temperature of 30°C followed by 25°C. IAA production was found to be increased with increasing tryptophan concentration (from 0.1 to 0.6%), however beyond this limit, a slight reduction in IAA production was observed. The strains’ ability to produce IAA was further confirmed by extraction of crude IAA and subsequent TLC analysis. A specific spot from the extracted IAA preparation was found corresponding with the standard spot of IAA with same Rf value. The results of HPLC analysis conducted in identifying and quantifying the IAA production more precisely, are in agreement with the results of the assessment done with colorimetric method. As revealed by the results of the pot experiment, the isolated strain could significantly enhance the growth (as measured by shoot and root growth) of mung bean plants compared to that of non-inoculated plants. Therefore it can be concluded that the present strain, Pantoea rodasii has great potential to be used as bio-inoculants.
        18.
        2007.10 KCI 등재 구독 인증기관·개인회원 무료
        Photodynamic therapy (PDT) is a clinically approved and ra pidly developing cancer treatment regimen, It is a minimally invasive procedure that requires the administration of a photosens iti zer foll owed by the illumination of the tumor with Iigh t of an appropriate wavelength, In the presence of molecular oxygen, cytotoxic intermedi a ries a re produced‘ thus damaging cellular structures containing the photosensitizer , In the present study. we exa mined the effectiveness of newly d evelped chlorin e6- induced PDT on malignant animal tumor model of 3prague-Da wley (3D) ra t Three-week-old male 3D rats we re inocula ted s ,c, on the right f1 ank with our previously esta blished k- ras-trans formed RK3E cell line (RK3E- ras. tota l, 5xl07 cell s) , The experiments were carried out 1 week after inoculation of tumor cell s , by which time the tumors had r eached about 0,7 mm to 1.0 cm in diameter, L3-chlorin e6 (L8 Pharm Co" Gwa ngju, Korea) was admin istrated intravenous ly by the tail vein of 3D rat at a dosage of 10 mg/kg after inhalation a nesthesia of ether, Twenty- four hours a fter L8-chlorin e6 ad ministration, PDT was pe rfol‘med using a laser diode (Geumgwang Co ‘ Ltd‘’ Daejeon, Korea) a t a light dose of 100 J /cm2 and wavelength of 664 nm, A..nimals were monitered daily and tumor volume was measured by calipel The tumor t reated with PDT using Ce6 had significant reduction in tumor s ize examined by gross tumor volume , softex x- ray image, molecular imaging a nalysis, respectively, PCNA immunostaining and TUNEL assay revealed that the treat ed tu mor caused signifi cant inlübition of tumor formati on with decreased tumor cell proliferation a nd increased a poptosis , Our dat a showed Ce6-induced PDT effecti vely arrested the tumor growth by inhibi t ing cell proliferation a nd inducing a poptosis , These findings provide the potential value of Ce6- induced PDT as an a lternative candidate for a nt i- tumor therapy, Furthel bi ochemical and cellular studies will reveal the precise molecul ar mecha ni sm of cell death induced by PDT
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