• 제목/요약/키워드: NAS

검색결과 286건 처리시간 0.023초

Species Profiles and Antimicrobial Resistance of Non-aureus Staphylococci Isolated from Healthy Broilers, Farm Environments, and Farm Workers

  • Ji Heon Park;Gi Yong Lee;Ji Hyun Lim;Geun-Bae Kim;Kun Taek Park;Soo-Jin Yang
    • 한국축산식품학회지
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    • 제43권5호
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    • pp.792-804
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    • 2023
  • Non-aureus staphylococci (NAS), particularly antimicrobial-resistant NAS, have a substantial impact on human and animal health. In the current study, we investigated (1) the species profiles of NAS isolates collected from healthy broilers, farm environments, and farm workers in Korea, (2) the occurrence of antimicrobial-resistant NAS isolates, especially methicillin resistance, and (3) the genetic factors involved in the methicillin and fluoroquinolone resistance. In total, 216 NAS isolates of 16 different species were collected from healthy broilers (n=178), broiler farm environments (n=18), and farm workers (n=20) of 20 different broiler farms. The two most dominant broiler-associated NAS species were Staphylococcus agnetis (23.6%) and Staphylococcus xylosus (22.9%). Six NAS isolates were mecA-positive carrying staphylococcal cassette chromosome mec (SCCmec) II (n=1), SCCmec IV (n=1), SCCmec V (n=2), or nontypeable SCCmec element (n=2). While two mecA-positive Staphylococcus epidermidis isolates from farm workers had SCCmec II and IV, a mecA-positive S. epidermidis isolate from broiler and a Staphylococcus haemolyticus isolate farm environment carried SCCmec V. The occurrence of multidrug resistance was observed in 48.1% (104/216 isolates) of NAS isolates with high resistance rates to β-lactams (>40%) and fusidic acid (59.7%). Fluoroquinolone resistance was confirmed in 59 NAS isolates (27.3%), and diverse mutations in the quinolone resistance determining regions of gyrA, gyrB, parC, and parE were identified. These findings suggest that NAS in broiler farms may have a potential role in the acquisition, amplification, and transmission of antimicrobial resistance.

Fault-Tolerance 기능을 갖는 HA NAS 시스템의 설계 및 구현 (Design and Implementation of HA NAS with Fault-Tolerance)

  • 김주영;박준희;권혁빈;서희정;정영준
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (1)
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    • pp.664-666
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    • 2004
  • 최근 업무에 컴퓨터를 이용하는 사례가 늘어나고, 각종 컨텐츠 서비스업계가 발전하면서 독립적인 파일 서버 기능만을 처리하도록 만든 네트워크 저장장치인 NAS(Network Attached Storage)의 이용이 점차 증가하는 추세에 있다. NAS는 기존 파일서버의 문제점을 보완하면서 이기종 플랫폼간의 파일 공유, 스토리지 확장성, 관리 용이성 등을 특징으로 한다. 그러나 NAS 시스템에 장애가 발생할 경우에는 막대한 경제적인 손실이 발생하게 된다. 따라서 본 논문에서는 NAS 시스템 장애가 발생하였을 때, 효율적으로 장애를 복구할 수 있는 HA(High Availability) NAS 시스템을 설계 및 구현하고, 다양한 장애 상황에서 NAS를 이용하는 서비스가 중단 없이 제공되는 것을 확인하였다

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Efficient Cryopreservation of In Vitro Grown Shoot Tips of Strawberry (Fragaria × ananassa Duch.) Germplasm Using Droplet-Vitrification

  • Bae, Jinjoo;Lee, Sun-Yi;Song, Jae-Young;Lee, Jung-Ro;Yoon, Munsup;Yi, Jung-Yoon;Kim, Haeng-Hoon;Lee, Young-Yi
    • 한국자원식물학회지
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    • 제34권6호
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    • pp.600-607
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    • 2021
  • Cryopreservation method using a droplet vitrification was applied to the thirty-one strawberry accessions of in vitro grown shoot tips. A protocol with 0.3 - 0.5 M preculture followed by C4 loading and B1 dehydration solutions efficiently implemented cryopreservation of twenty-six strawberry accessions. The highest regrowth rate was 85.8% for PHS0007 and others were ranged between 85.8% and 21.0%. A slightly modified protocol was applied to five accessions. With these two protocols, twenty-eight accessions obtained more than 40% regrowth rate. This study showed that the droplet vitrification method was able to practically implement cryopreservation of in vitro grown shoot tips of broad range of strawberry germplasm (105).

Intraplant Variations of Sesquiterpene Lactone Content in Lettuce Genetic Resources Grown in Two Cultivation Seasons

  • Assefa, Awraris Derbie;Choi, Susanna;Sung, Jung-Sook;Hur, On-Sook;Ro, Na-Young;Lee, Sok Young;Lee, Ho-Sun;Lee, Jae Eun;Rhee, Ju-Hee
    • 한국자원식물학회지
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    • 제31권5호
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    • pp.538-546
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    • 2018
  • Inflorescence, stem, and leaf samples of lettuce grown in a greenhouse in spring and autumn seasons were assayed for sesquiterpene lactones (SLs) content by high performance liquid chromatography. The concentrations of SLs were significantly higher in the inflorescences followed by upper leaf and stem compared to the other plant parts in most of the samples. SLs content (sum of lactucin and lactucopicrin) in various tissues of lettuce cultivated in spring season varied from 5.7 to 22.5 fold ranging from $27.4{\mu}g/g$ dry weight (DW) in the upper stem (cultivar "PI 176588") as the lowest to as high as $2,292.0{\mu}g/g$ DW in the inflorescence (cultivar "709849-1"). During autumn cultivation, the concentration of SLs varied from 2.0 to 14.4 fold ranging from as low of $32.4{\mu}g/g$ DW in the lower stem (cultivar "PI176588") to as high of $838.0{\mu}g/g$ DW in the upper leaf (cultivar "Dambaesangchu"). Higher lactucin (1.2 to 5.6 fold) and lactucopicrin (1.1 to 3.9 fold) concentration was observed during spring compared to autumn cultivation in most of the samples. SLs content in various organs of lettuce increases from the basal plant part going upwards. As lactucin and lactucopicrin are the major SLs which affects the sensory property of lettuce, their quantitative variation in the lettuce cultivars is useful for breeding new varieties with better consumer acceptance.

Cryopreservation of in vitro Grown Shoot Tips of Two Freesia hybrida Cultivars by Droplet-vitrification

  • Jinjoo Bae;Jae-Young Song;Ji-Won Han;Ho Cheol Ko;Sung-Hee Nam;Jung-Ro Lee;Ho-sun Lee
    • 한국자원식물학회지
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    • 제36권6호
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    • pp.562-570
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    • 2023
  • The droplet-vitrification technique for cryopreservation has proven successful across a diverse range of germplasm, ensuring safe and effective long term preservation. In this study, we investigate an effective cryopreservation protocol using the droplet-vitrification technique for shoot tips of Freesia hybrida cultivars 'Sunny Gold' and 'Sweet Lemon'. To determine optimal conditions for Freesia cryopreservation, we employed a carefully selected standard procedure along with additional treatments and alternative solutions. For 'Sunny Gold', the highest regrowth rate of 24% was achieved when shoot tips underwent dehydration with PVS3 solution for 120 minutes before direct immersion in liquid nitrogen (LN) for 1 hour, coupled with a standard protocol involving a two-step preculture with 0.3 M - 0.5 M sucrose, loading with C4 for 40 minutes, and unloading with 0.8 M sucrose for 40 minutes. In the case of 'Sweet Lemon,' regrowth of cryopreserved shoot tips was observed with dehydration treatments, including PVS2 (A3) for 60 minutes and PVS3 (B1) for 60 minutes, as well as longer exposure. The results reflect the distinct sensitivity of shoot tips to chemical toxicity and osmotic stress in these two genotypes. This study provides valuable evidence to consistently enhance the effectiveness of cryopreservation methods for the long-term conservation of Freesia germplasm.

CD72 is a Negative Regulator of B Cell Responses to Nuclear Lupus Self-antigens and Development of Systemic Lupus Erythematosus

  • Takeshi Tsubata
    • IMMUNE NETWORK
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    • 제19권1호
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    • pp.1.1-1.13
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    • 2019
  • Systemic lupus erythematosus (SLE) is the prototypic systemic autoimmune disease characterized by production of autoantibodies to various nuclear antigens and overexpression of genes regulated by IFN-I called IFN signature. Genetic studies on SLE patients and mutational analyses of mouse models demonstrate crucial roles of nucleic acid (NA) sensors in development of SLE. Although NA sensors are involved in induction of antimicrobial immune responses by recognizing microbial NAs, recognition of self NAs by NA sensors induces production of autoantibodies to NAs in B cells and production of IFN-I in plasmacytoid dendritic cells. Among various NA sensors, the endosomal RNA sensor TLR7 plays an essential role in development of SLE at least in mouse models. CD72 is an inhibitory B cell co-receptor containing an immunoreceptor tyrosine-based inhibition motif (ITIM) in the cytoplasmic region and a C-type lectin like-domain (CTLD) in the extracellular region. CD72 is known to regulate development of SLE because CD72 polymorphisms associate with SLE in both human and mice and CD72-/- mice develop relatively severe lupus-like disease. CD72 specifically recognizes the RNA-containing endogenous TLR7 ligand Sm/RNP by its extracellular CTLD, and inhibits B cell responses to Sm/RNP by ITIM-mediated signal inhibition. These findings indicate that CD72 inhibits development of SLE by suppressing TLR7-dependent B cell response to self NAs. CD72 is thus involved in discrimination of self-NAs from microbial NAs by specifically suppressing autoimmune responses to self-NAs.

대용량 에너지 저장시스템을 위한 나트륨 유황전지 (Sodium Sulfur Battery for Energy Storage System)

  • 김둘선;강성환;김준영;안주현;이창희;정기영;박윤철;김고운;조남웅
    • 전기화학회지
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    • 제16권3호
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    • pp.111-122
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    • 2013
  • 나트륨 유황전지(NAS)는 대용량 에너지 저장시스템(energy storage system, ESS) 중 하나로서, 최근 풍력에너지, 태양에너지, 해양에너지 등 그린재생에너지의 사용증가로 ESS에 대한 수요가 급증함에 따라 NAS 전지에 대한 관심이 고조되고 있다. NAS 전지는 에너지 밀도가 높고(납 축전지밀도의 3배), 사이클 수명이 길고, 자가방전이 없어 대용량 전력저장 시스템에 적합하다. NAS 전지는 양극으로 황(Sulfur), 음극으로 나트륨(Na), 고체전해질 및 분리막으로 ${\beta}$"-알루미나($Al_2O_3$)로 구성되어 있고, 양극 활물질인 황은 부도체이기 때문에 도전재인 탄소섬유(carbon felt)에 함침시켜 양극으로 사용해야 함으로, 양극재 구성 및 특성은 전지성능에 상당한 영향을 미치게 된다. 따라서 본 논문에서는 NAS 전지의 구성, 다황화나트륨($Na_2S_x$, 방전생성물) 및 양극재의 특성, 전지 성능에 미치는 영향인자들에 대해서 알아보고자 한다.

국내 재배 상추로부터 UPLC-DAD-QToF/MS를 이용한 페놀화합물 성분 비교 연구 (Study on Phenolic Compounds in Lettuce Samples Cultivated from Korea Using UPLC-DAD-QToF/MS)

  • 김헌웅;이선혜;;이민기;이수지;박진주;최용민;이상훈
    • 한국식품영양학회지
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    • 제32권6호
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    • pp.717-729
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    • 2019
  • The chemical informs about 70 individual phenolic compounds were constructed from various lettuce samples based on literature sources and analytical data. A total of 30 phenolic compounds including quercetin 3-O-glucuronide, quercetin 3-O-(6''-O- malonyl) glucoside, cyanidin 3-O-(6''-O-malonyl)glucoside, chlorogenic acid and chicoric acid as major components were identified in 6 lettuce samples from Korea using UPLC-DAD-QToF/MS on the basis of constructed library. Among these, quercetin 3,7-di-O-glucoside(m/z 627 [M+H]+), quercetin 3-O-(2''-O-malonyl)glucoside(morkotin C, m/z 551 [M+H]+), quercetin 3-O-(6''- O-malonyl)glucoside methyl ester(m/z 565 [M+H]+), 5-O-cis-p-coumaroylquinic acid(m/z 339 [M+H]+) and 5-O-caffeoylquinic acid methyl ester(m/z 369 [M+H]+) were newly confirmed from the lettuce samples. In total content of phenolic compounds, 4 red lettuce samples(2,947.7~7,535.6 mg/100 g, dry weight) showed higher than green lettuce(2,687.3 mg) and head lettuce(320.1 mg).

Comparison of Glucosinolate Contents in Leaves and Roots of Radish (Raphanus spp.)

  • Ko, Ho-Cheol;Sung, Jung-Sook;Hur, On-Sook;Baek, Hyung-Jin;Jeon, Young-ah;Luitel, Binod Prasad;Ryu, Kyoung-Yul;Kim, Jung-Bong;Rhee, Ju-Hee
    • 한국자원식물학회지
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    • 제30권6호
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    • pp.579-589
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    • 2017
  • Glucosinolates (GSLs), beneficial secondary metabolites for human health are abundantly present in radish vegetable. Radish is a member of Brassicaceae family and its seed, leaf and root contain very important GSLs. The objective of this study was to determine the variation of individual and total GSL contents in leaves and roots of 44 radish (Raphanus spp.) germplasm (26 R. sativus L., 3 R. raphanistrum, and 15 R. sativus L. var. raphanistroides Makino), and compare the GSL contents between leaves and roots among three Raphanus species. Thirteen GSLs were identified, being the glucoraphasatin (GRS) and glucobrassicin (GBS) the most abundant aliphatic and indolyl GSLs in both the leaves and roots. Variation in individual and total GSL contents was found among the germplasm of three Raphanus species. The GRS content was higher in roots than that of leaves in all three Raphanus species but the GBS content was higher in leaves than roots. GRS was represented 87.0%, 92.7% and 94.7% of the total GSL in roots of R. sativus L., R. raphanistrum and R. sativus L. var. raphanistroides (Makino) germplasm, respectively. Germplasm of R. raphanistrum exhibited the highest (average, $79.5{\mu}mol/g\;dw$) total GSL with a ranged from 62.7 to $92.9{\mu}mol/g\;dw$. The germplasm IT119288, Joseonmu and IT119262 from R. sativus L., RA 504 and K046542 from R. raphanistrum, and Gyeongju-2003-32 (G2003-32) and IT302373 from R. sativus L. var. raphanistroides (Makino) had high total GSL contents and these could be good candidates for developing the functional compounds-rich varieties in radish breeding program.