목 적 : 자기공명영상(MRI)의 발달은 소아신경계의 병리학적 과정을 이해하고 진단하는데 중요한 역할을 하고 있으며 그 검사 건수는 나날이 증가하고 있다. 하지만 이같은 장점에도 불구하고 소아의 Brain MR 검사는 환자에게 주의를 주거나 Sedation을 하여 검사를 진행하지만 움직임, 소음 등으로 인하여 실패하는 경우가 발생한다. 고해상력의 영상 획득이 가능한 3.0T의 경우 1.5T에 비해 SAR가 약 4배 증가하게 되며, 최근 미국 소아과학회에서는 어린이가 어른보다 전자파에 더 큰 영향을 받기 때문에 더욱 주의하여 관리해야 한다고 주장하고 있다. 이때, 기존의 TSE가 아닌 다양한 Refocusing FA를 사용하는 Hypere-TSE은 동등한 SNR을 유지하면서 SAR를 감소시키기 때문에 그 해결책이 될 수 있다. 또한, MR 검사 시의 소음은 Gradient의 빠른 Switching을 통해 발생하는데, 이러한 기존의 소음 감소를 위한 Gradient mode인 Whisper mode는 Scan time이 증가하는 등의 단점이 있었으나 최근 E11 Upgrade를 통해 도입된 Acoustic noise reduction는 이를 개선하여 동등한 Scan time과 향상 된 소음 감소 효과를 가져왔다. 이에 본 연구에서는 소아 Brain MRI 검사 시 Hyperecho와 Acoustic Noise Reduction을 이용하여 Image quality를 동등하게 유지하면서 소아를 더욱 안전하고 안정된 환경에서 검사할 수 있는 방법을 제안하고자 한다. 대상 및 방법 : 장비는 SIEMENS사의 3.0T SKYRA(Germany)와 32ch Head coil을 사용하였고, Spherical Phantom D165(Siemens, Germany) 및 만 15세 이하의 소아 환자 20명(남자 12, 여자 8, 평균연령 6세)을 대상으로 하였다. Hyper-TSE와 Acoustic noise reduction을 사용했을 때와 사용하지 않았을 때의 T1 Dark fluid(TR: 2000, TE: 9, TI: 900, Matrix: 384*307, FOV: 200*200, NEX: 1) T2WI(TR: 6000 TE: 103, Matrix: 448*269, FOV: 200*200, NEX: 2), T2 FLAIR(TR: 9000, TE: 84, TI: 2500, Matrix: 320*192, FOV: 200*200, NEX: 1)에서 비에스코리아사의 디지털 소음 측정기를 통하여 Isocenter에서 150㎝ 거리에서의 소음을 측정하였고, SAR와 SNR은 Siemens NUMARIS/4 - syngo MR E11로 Gray matter, White matter, Eye ball을 관심 영역 0.02㎠ 측정하여 IBM SPSS Statistics v22.0을 통해 정량적 분석을 하였다. 결 과 : 정량분석 결과 Hyper-TSE와 Acoustic noise reduction을 사용했을 때는 사용하지 않았을 때에 비해 SAR가 T1 Dark fulid에서 -26%, T2에서 -33%, T2 FLAIR에서 –33%로 감소되었으며, 소음은 T1 Dark fulid에서 -14%, T2에서 -16.6%, T2 FLAIR에서 –16.1% 감소하였고, SNR은 T1 Dark fulid에서 GM: 17%, WM: 15%, Eye ball: 12%, T2에서 GM: 10%, WM: 14%, Eye ball: 14%, T2 FLAIR에서 GM: 3%, WM: 9%, Eye ball: 7%로 증가한 것으로 나타났다. CNR은 T1 Dark fulid에서 14%, T2에서 3%, T2 FLAIR에서 –19%로 증감된 것으로 나타났다. 비모수 대응표본 Wilcoxon T검정을 실시한 결과 대부분의 값에서 유의한 차이(p<.05)가 있는 것으로 나타났다. 결 론 : Hyperecho를 사용하게 되면 SNR을 유지하면서 SAR를 상당히 감소시킬 수 있다는 것과 Acoustic noise reduction을 사용할 경우 동일하거나 약간의 검사 시간 증가와 함께 많이 조용하게 된다는 이론적 사실을 바탕으로 안전하고 안정된 환경을 만들기 위해 노력하였다. 이번 연구를 통해 Hyperecho 및 Acoustic noise reduction을 사용할 경우 기존의 Sequence와 비교하여 SAR와 소음은 감소시키면서 SNR과 CNR 값은 동등하거나 증가된 영상을 얻을 수 있고 이를 통하여 소아 환자에게 더욱 안전하고 안정된 환경을 제공하고 효과적이며 진단 가치 높은 영상을 얻을 수 있으리라 사료된다.

목 적 : GRAPPA 기법을 이용하는 검사에서 GRAPPA factor는 k-공간 내에 누락시 킬 신호의 양을 결정하고 검사시간을 줄이는 변수이다. 하지만 GRAPPA factor가 증가할수록 영상의 SNR이 저하되고 인공물이 증가하는 제한점이 있다. 따라서 본 연구에서는 GRAPPA factor와 ACS Line 수를 변화시켜 영상 화질과의 상관관계를 평가하여 분석하고자 하였다. 대상 및 방법 : VIBE sequence를 사용하여 GRAPPA factor를 2, 3, 4, 5로 ACS Line의 수는 20, 40, 60, 80, 100, 120로 증가시키고 검사하였다. 화질 평가를 위해 영상의 SNR을 측정하였고 GRAPPA 기법을 이용하지 않은 영상과 GRAPPA 기법을 이용한 영상의 유사성(SSIM)을 평가하였다. 또한 GRAPPA factor를 2, 3, 4, 5로 고정하였을 때 ACS Line과 SNR, ACS Line과 SSIM의 상관관계분석을 실시하였다. 결 과 : GRAPPA factor가 증가 할수록 SNR은 저하되었고 같은 GRAPPA factor의 조건에서 ACS line의 수가 증가 할수록 SNR은 증가되었다. GRAPPA 기법을 이용하지 않은 영상과 GARPPA기법을 이용한 영상의 유사성 평가에서는 GRAPPA factor가 증가 될수록 SSIM은 저하되었고 같은 GRAPPA factor의 조건에서 ACS Line의 수가 증가 될수록 SSIM은 1에 가까워졌다. ACS Line의 수와 SNR의 상관관계분석 결과 GRAPPA factor가 2일 경우 Pearson 상관계수가 0.291, GRAPPA factor가 3일 경우 0.458, GRAPPA factor가 4일 경우 0.779, GRAPPA factor가 5일 경우 0.88로 나타났다. ACS Line의 수와 SSIM의 상관관계분석 결과 GRAPPA factor가 2일 경우 Pearson 상관계수가 0.787, GRAPPA factor가 3일 경우 0.792, GRAPPA factor가 4일 경우 0.918, GRAPPA factor가 5일 경우 0.946로 나타났다. 결 론 : GRAPPA 기법을 이용하는 검사에서 GRAPPA factor를 증가시킬 경우 검사시간이 감소하지만 SNR이 저하되고 인공물이 증가하는 제한점이 있다. 따라서 GRAPPA 기법을 이용하였을 때 검사에 영향을 주지 않은 시간 내에서 ACS Line의 수를 최대로 사용하면 SNR 증강 효과와 더불어 인공물을 개선할 수 있고 GRAPPA factor가 높을 경우 ACS Line의 수를 증가시키면 개선효과가 더 클 것으로 사료된다.

Simple sequence repeats (SSR), also referred to “microsatellites” consist of tandemly repeated short DNA sequence motifs and have been applied in various marker-based studies. SSRs were isolated and characterized from ‘Heuktari’ and ‘Miso’, which are major oyster mushroom cultivars in Korea, by genome sequencing and bioinformatic analysis. The genome sizes of ‘Heuktari’ and ‘Miso’ were estimated to be 40.8 and 40.3 Mb, respectively, which are larger than those of other P. ostreatus species (PC9 and PC10) and smaller than those of P. eryngii (KNR2312P5). In total, 949 and 968 SSRs were found in the ‘Heuktari’ and ‘Miso’ genomes, respectively. Comparative analysis of five mushrooms including P. ostreatus var. florida (PC9 and PC15) and P. eryngii revealed that the number of SSRs in ‘Heuktari’ and ‘Miso’ were the highest among them. All mushrooms studied showed similar SSR distribution patterns. Tri-, hexa-, and octanucleotide motifs accounted for the top three fractions of all SSRs.

We present photometric results of the  Sct star V1162 Ori, which is extensively monitored for a total of 49 nights from mid-December 2014 to early-March 2015. The observations are made with three KMTNet (Korea Microlensing Telescope Network) 1.6 m telescopes installed in Chile, South Africa, and Australia. Multiple frequency analysis is applied to the data and resulted in clear detection of seven frequencies without an alias problem: five known frequencies and two new ones with small amplitudes of 1.2-1.7 mmag. The amplitudes of all but one frequency are significantly different from previous results, confirming the existence of long-term amplitude changes. We examine the variations in pulsation timings of V1162 Ori for about 30 years by using the times of maximum light obtained from our data and collected from the literatures. The O − C (Observed minus Calculated) timing diagram shows a combination of a downward parabolic variation with a period decreasing rate of (1/P)dP/dt = −4.22 × 10−6 year−1 and a cyclic change with a period of about 2780 days. The most probable explanation for this cyclic variation is the light-travel-time effect caused by an unknown binary companion, which has a minimum mass of 0.69 M⊙. V1162 Ori is the first  Sct-type pulsating star of which the observed fast period decrease can be interpreted as an evolutionary effect of a pre-main sequence star, considering its membership of the Orion OB 1c association.

Differentiation of Pleurotus eryngii is laborious and time-consuming tasks especially in mycelial status. For development of a method for differentiation of P. eryngii cultivars, simple sequence repeats (SSR) from whole genomic DNA sequence analysis was used for genotyping and two multiplex-SSR primer sets were developed. These SSR primer sets were employed to distinguish 12 cultivars and strains. Five polymorphic markers were selected based on the genotypes. PCR with the each primer produced one to four distinct bands ranging in size from 200 to 300 bp. Polymorphism information content (PIC) values of the five markers were in range of 0.6627 to 0.6848 with an average of 0.6775. Unweighted pair-group method with arithmetic mean clustering analysis based on genetic distances using five SSR markers classified 12 cultivars into 2 clusters. Cluster I and II comprised of 4 and 8 cultivars, respectively. Two multiplex sets, Multi-1 (SSR312 and SSR366) and Multi-2 (SSR178 and SSR277) completely discriminated 12 cultivar and strains with 21 allele with a PIC value of 0.9090. These results might be useful to provide an efficient method for the identification of P. eryngii cultivars with separate PCR reactions. (This work was supported by a grant from the Golded Seed Project (213003-04-3-SBY20), MIFAFF, Republic of Korea.]

목 적 : 두경부는 해부학적 구조가 복잡하기 때문에 두경부 검사 시 고해상도의 영상을 필요로 하게 된다. 하지만 고해상도의 영상을 얻기 위한 검사 시 상악부에 치과 보철물이 삽입되어 있거나 뇌동맥 coil이 있는 경우 1.5T에 비해 3T는 자화 감수성의 차이가 더욱 더 커지게 되어 metallic susceptibility artifact가 크게 나타나게 된다. 이에 자기 공명 확산강조 검사 시 자장 세기의 증가로 인한 금속물질에 대한 metallic susceptibility artifact의 증가와 기존의 3T에서 Single shot DWI를 이용한 DWI검사에 비해 RESOLVE technique을 이용한 DWI 검사 시 metallic susceptibility artifact의 감소에 대한 유용성을 알아보고자 한다. 대상 및 방법 : 치과보철물(백금78%+metal) 과 임플란트(티타늄+메탈), 두 개내 혈관용 코일(10cm)을 기존의 Single shot DWI를 이용하여 scan을 시행하고 RESOLVE를 이용하여 3T에서 각각 5회씩 Scan하였다. 또한 자장의 강도에 따른 자화 감수성의 변화를 알아보기 위하여 1.5T에서 Single shot DWI를 5회 추가로 scan하였다. 사용된 장비는 SIEMENS사의 Avanto 1.5T와 Skyra 3.0T를 사용하였으며 1.5T에서 진행한 Scan parameter는 FOV 220mm, matrix 190, slice Thickness 5.0mm, slice gap 1.5mm, TR 4000ms, TE 95ms, slice수 24이며 3.0T에서 진행한 single shot DWI scan parameter는 FOV 220mm, matrix 190, slice Thickness 5.0mm, slice gap 1.5mm, TR 5300ms, TE 87ms, slice수 24이며 3.0T에서 진행한 REOLVE DWI scan parameter는 FOV 220mm, matrix 190, slice Thickness 5.0mm, slice gap 1.5mm, TR 4700ms, TE1 68ms, TE2 112ms, slice수 24, readout segment 7 이며 phase encoding 방향은 Anterior-Posterio로 모두 동일하게 하였다. arifact의 측정은 marosis사의 M-view의 length tool을 이용하여 b-value 0은 window width(이하 ww) 1800 window level(이하 wl) 1000, b-value 1000은 ww 1000, wl 500으로 ADC는 ww 3000, wl 1500으로 고정하여 10년 이상의 경력을 가진 방사선사 3인이 5회씩 측정한 후 평균값을 산출하였다. 결 과 : 측정결과 급성뇌경색 진단에 주로 사용하는 b-value 1000에서 백금 78%+metal은 평균 측정치 1.5T single shot DWI 44.76mm, 3.0T single shot DWI 47.96mm, 3.0T RESOLVE 36.13mm이며 임플란트(티타늄)는1.5T single shot DWI 31.26mm, 3.0T single shot DWI 37.44mm, 3.0T RESOLVE 32.48mm이고 두 개 내 코일은 1.5T single shot DWI 19.76mm, 3.0T single shot DWI 31.20mm, 3.0T RESOLVE 16.44mm로 모든 실험에서 3.0 single shot >1.5Tsingle shot> 3.0T RESOLVE순으로 Metallic artifact가 크게 나타났으며 재료별로는 보철물>임플란트>코일 순으로 Metallic artifact가 크게 나타났다 결 론 : 확산 강조 자기공명 검사에서 자장의 세기가 증가할 때 metallic susceptibility artifact는 더욱 크게 나타나며 RESOLVE를 사용한 확산강조 자기공명 검사는 자화율차이에 의한 왜곡에 효과적이며 보철물이나 뇌동맥 coil과 같은 금속물이 삽입되어 있는 두경부 검사에서 metallic susceptibility artifact를 감소시키는데 그 유용성이 매우 큰 것으로 사료된다

The genus Pediococcus belongs to the lactic acid bacteria and includes 15 species which are used in the food industry as both starter and probiotic cultures. The importance of Pediococcus spp. is due to their use as starter cultures in fermented meat as well as to their presence as the natural microbiota in vegetables. The availability of P. pentosaceus in the food industry increases the need for reliable molecular techniques for strain identification. To date, the reliable molecular methods for definite identification at strain level of microorganisms used in food industry has not been developed. Molecular identification based on suitable marker genes could be a promising alternative to conventional molecular typing methods such as ribotyping. In this study, the applicability of seven housekeeping genes gyrB, pyc, pgm, leuS, glnA, and dalR in combination with the pgi gene in multilocus sequence typing of P. pentosaceus was assessed. Sequencing and comparative analysis of sequence data were performed on 6 strains isolated from various vegetables. In addition to 17 sequence types, two new sequence types were identified and these fortified sequence types and seven marker genes allowed for a clear differentiation of the strains analyzed, indicating their applicability in molecular typing.

Pleurotus eryngii, an edible white-rot fungus, is widespread in Eurasia and northern Africa. It has become a major cultivated mushroom in Asia, with a current global production rate of approximately 3 × 10 5 metrictons/yr. To improve the quality or productivity through breeding, a genetic linkage map is an important component. In this study, genetic linkage map of the P. eryngii was constructed using 98 monokaryotic progeny derived from dikaryon of parental KNR2312 strain derived from haploid meiotic spores. The whole genome sequence of P5 monokaryon from P. eryngii KNR2312 strain by Next Generation Sequencing (NGS) strategy was used to design the SSR markers. 484 primers pairs were identified by SSR Locator I and tested polymorphism via PCR. A total of 241 loci were mapped using Joinmap 4.0, comprising 222 SSR markers, 2 mating type factors, and the 13 INDEL markers. The map consisted of 14 linkage groups spanning 1003 cM at an average marker interval of 4.2 cM. The mating loci, A and B were mapped on linkage groups 4 and 11, respectively. The established linkage map and the genetic information based on NGS could be used for QTL mapping of agronomic traits, marker-assisted breeding that may ultimately lead to outstanding phenotypic characteristics. [Supported by a grant from the IPET (213003-04-3-SBY20), MIFAFF, Republic of Korea.]

Differentiation of Pleurotus eryngii is laborious and time-consuming tasks especially in mycelial status. For development of a method for differentiation of P. eryngii cultivars, simple sequence repeats (SSR) from whole genomic DNA sequence analysis was used for genotyping and two multiplex-SSR primer sets were developed. These SSR primer sets were employed to distinguish 12 cultivars and strains. Five polymorphic markers were selected based on the genotypes. PCR with the each primer produced one to four distinct bands ranging in size from 200 to 300 bp. Polymorphism information content (PIC) values of the five markers were in range of 0.6627 to 0.6848 with an average of 0.6775. Unweighted pair-group method with arithmetic mean clustering analysis based on genetic distances using five SSR markers classified 12 cultivars into 2 clusters. Cluster I and II comprised of 4 and 8 cultivars, respectively. Two multiplex sets, Multi-1 (SSR312 and SSR366) and Multi-2 (SSR178 and SSR277) completely discriminated 12 cultivar and strains with 21 allele with a PIC value of 0.9090. These results might be useful to provide an efficient method for the identification of P. eryngii cultivars with separate PCR reactions. (This work was supported by a grant from the Gold Seed Project [Supported by a grant from the IPET (213003-04-3-WTI11), MIFAFF, Republic of Korea.]

The aim of this study was to analyze the genetic diversity of collected strains of Hypsizygus marmoreus based on their rDNA ITS sequences. The size of ITS rDNA regions of H. marmoreus strains, collected form various regions. A phylogenetic trees based on the ITS region revealed that the strains could be classified into 4 different groups including Villosiclava virens, Hypsizygus marmoreus, Lepista irina, Lyophyllum Decastes, Lyophyllum shimeji, Pleurotus floridanus.

The Hawthorn spider mite Amphitetranychus viennensis is an important pest of various fruit trees as well as a variety of ornamental plants. Its presence has been reported in China, Japan, Korea, and middle east and European countries including Grorgia, Russia, Turkey, Ukraine. Thus, it is a quarantine species in American countries and Australia. Intra-specific variation of A. viennensis was investigated using 555 bp of ITS2 ribosomal DNA and 453 bp of the cytochrome oxidase I (COI) gene. Its variation of ITS2 and COI among China, Japan and Korea were 1.7-2.2% and 0.2-0.7%, respectively. In addition, we collected samples from 14 location in Korea. Intra-specific diversity of ITS2 and COI within Korean populations were ranged into 0.5-0.9% and 0.2-0.5%, respectively. Thus, A. viennensis is not much genetically diverse in different populations.

The JpL species is one of the 31 species belonging to the Bemisia tabaci complex and is distributed in two countries, Korea and Japan. To clarify genetic relationships among different populations of the JpL species in Korea, 83 cytochrome oxidase subunit I (COI) sequences generated from 83 individuals collected from eight Korean provinces were analyzed together with published 16 Korean COI sequences. A total of eight haplotypes were detected from the 99 COI sequences, and 82 COI sequences shared one haplotype, hap-2. The remaining 17 COI sequences were assigned to seven haplotypes, hap-1, 3, 4, 5, 6, 7, and 8. The median-joining networks of the eight haplotypes revealed that the Korean JpL species has undergone genetic variations separately according to two groups, Korean Peninsula and Jeju Island. In addition, the phylogenetic trees constructed based on the 99 COI sequences and published seven Japanese COI sequences were divided into two clades: clade(A) consisted of 97 COI sequences from the Korean Peninsula group, and clade(B) consisted of 19 COI sequences from the Jeju Island and Japan groups. Our study suggests that the Korean populations of the JpL species might have spread and be undergoing genetic variations separately according to the two groups, Korean Peninsula and Jeju Island.

Twenty Inter simple sequence repeat (ISSR) primers were used to assess genetic diversity of 64 Agaricus strainsincluding 45 A. bisporus strains and other 19 Agaricus spp. ISSR primers, (GA)T, (AG)YC, (GA)C and (CTC) amplified PCRpolymorphic bands between the Agaricus species or within A. bisporus strains. PCR polymorphic bands were inputted forUPGMA cluster analysis. The varieties, Saea, Saedo, Saejeong and Saeyeon that have recently been developed in Korea wereinvolved in the same group with closely genetic relationship of coefficient similarity over 0.92, whereas, other Korean strains weregenetically related to A. bisporus strains that were introduced from USA, Eroupe and Chinese. Furthermore, ISSR-PCRpolymorphism could potentially be used to identify homokaryon isolates.