For application in nuclear decommissioning, underwater laser cutting studies were conducted on thick stainless-steel plates for various cutting directions using a 6 kW fiber laser. For cutting along the horizontal direction with horizontal laser irradiation, the maximum cutting speed was 110 mm∙min−1 for a 48 mm thick stainless-steel plate. For cutting along the vertical direction with horizontal laser irradiation, a maximum speed of 120 mm∙min−1 was obtained for the same thickness, which confirmed that the cutting performance was similar but slightly better. Moreover, when cutting with vertically downward laser irradiation, the maximum cutting speed was 120 mm∙min−1 for a plate of the same thickness. Thus, the cutting performance for vertical irradiation was nearly identical to that for horizontal irradiation. In conclusion, it was possible to cut thick stainless-steel plates regardless of the laser irradiation and cutting directions, although the assist gas rose up due to buoyancy. These observations are expected to benefit laser cutting procedures during the actual dismantling of nuclear facilities.

최근 기후변화 및 국제교역량, 여행객, 외국 이주민 증가 등으로 국내 농작물에 큰 피해를 입힐 수 있는 고위험 식물병의 유입이 꾸준히 증가하고 있다. 검역 대상인 병원체의 수가 증가함에 따라 검역기관 및 연구원의 업무량이 증가하고 있다. 본 연구에서는 지역별 주요 수출대상 과수인 포도, 단감, 감귤의 국내 미기록 병과 원인병원체에 대한 예찰조사를 수행하였다. 이를 위해 전국을 경기-강원, 충청, 전북, 전남, 경북, 경남 그리고 제주 등 7개 권역으로 나누고 각 권역 소재 대학에서 예찰조사를 수행하여 예찰네트워크를 구축하고자 하였다. 포도 대상 병은 모두 4종으로, Pierce’s disease (Xylella fastidiosa), brown rot (Monilinia fructigena), anthracnose (Greeneria uvicola), 그리고 esca (Phaeomoniella chlamydospora)을 조사하였고 경기-강원, 충청도, 전라북도, 그리고 경상북도 권역을 중심으로 각 권역당 3개 지역 그리고 지역당 3개 지점을 두고 조사하였다. 단감은 모두 3종으로, brown spot (Fusicladium levieri), black leaf spot (Adisciso kaki), 그리고 black spot (Phoma kakivora)을 조사하였고 국내 단감 주생산지인 경상남도와 전라남도 권역을 중심으로 각 권역당 3개 지역 그리고 지역당 3개 지점을 두고 조사하였다. 감귤 대상 병은 모두 2종으로, citrus scab (Elsinoë australis), Septoria spot (Septoria citri)을 조사하였고 감귤 주생산지인 제주권역을 중심으로 조사하였다. 모두 9종에 대한 예찰조사는 2019년 4월부터 10월까지 2주간격으로 실시하였다. 예찰조사결과 주요 수출대상 과수인 포도, 단감, 감귤의 국내미기록병 9종에 대한 원인병원체는 발견되지 않았다. 이 연구를 통해 식물병을 조기에 탐지할 수 있는 전국적인 모니터링 시스템을 구축하였고, 국외 외래유입병들의 예찰조사를 위한 지역 거점을 확보하였다고 평가된다.

The aim of this paper is to consider the effect of the manufacturing processes on corrosion and centerline cracking of ancient bronze spoons. The ancient bronze spoons in question were made by several steps of forging, in reheated condition with cast ingots. The manufacturing method is similar to that of the modern spoons. The investigations include observations from light and scanning electron microscopes of the microstructure in terms of the crack propagation. Cracks in the centerline are caused by solute segregation in the center-line region; this solute is solidified in the final stage of bronze spoon manufacture. Centerline cracking is also caused by α phase segregation, accompanied by forged overlapping along the longitudinal direction of the spoons. A vertical stripe with cracks along the centerline of the spoon’s width is formed by folding in the wrought process. The overlapping area causes crack propagation with severe corrosion on the spoon surfaces over a period of a thousand years. The failure mechanisms of ancient bronze spoons may be similar to that of modern spoons, and the estimation of the failure mechanisms of ancient spoons can be appropriate to determine failure causes for such modern spoons.

Plenty of variations in nutritional, morphological and agronomic traits occur in the pigmented rice germplasm. The current study was conducted to evaluate the growth characteristics of 71 pigmented rice genotypes having different origin taking one Korean landrace (Heugjinjubyeo) as control. Amongst the twenty eight growth characters studied; leaf length, leaf width, ligule length, panicle length and panicles per hill showed a higher degree of variance. The heading dates of the pigmented rice germ plasm were distributed from Aug. 1 to Sep. 28. Thirty five cultivars that headed or flowered in August were found adaptable for cultivation in Korea. The mean culm length and panicle length were significantly higher than Heugjinjubyeo but most of cultivars having strong or middle of culm strength made it possible to produce the stable yield. Some cultivars showed unique qualitative characters such as openness of culm angle, purple ligule, auricle, awn and glume colors, poor panicle exsertion and long empty glume. Nine cultivars including Heugjinjubyeo showed purple seed coat color while those of the others (62 cultivars) were of red seed coat.

Injection of nematicides such as emamectin benzonate and milbemectin is the most common practice to control the pinewood nematode, Bursaphelenchus xylophilus, in Korea. These macrocyclolactone nematicides, however, are expensive, limiting their practicability despite of high efficacy. In an attempt to screen affordable alternative organophosphate (OP) and carbamate (CB) nematicides, we identified and characterized three acetylcholinesterases (ACE, EC 3.1.1.7) from B. xylophilus and functionally expressed them using baculovirus system. In inhibition assay using 11 OPs and 3 CBs, all the three ACEs were highly inhibited by paraoxon, DDVP, chlorpyrifos-oxon and mevinphos of OPs and carbofuran and carbaryl of CBs but not inhibited well by the others. Interestingly, inhibition assay revealed that BxACE-3 is less sensitive to all insecticides tested than other two ACEs. In additional bioassay, chlorpyrifos, DDVP and parathion showed a high LC50 but all CBs tested did a very low mortality. The inhibition kinetic data and bioassay data obtained in this study should provide essential information for the development of OP-based nematicidal agents against B. xylophilus. Availability of expressed ACE will also facilitate the development of in vitro screening system to develop potential OP nematicides.

The pinewood nematode, Bursaphelenchus xylophilus (Steinner & Buhrer) Nickle, has two different life stages according to several environmental factors: dispersal stage and propagative stages. The dispersal stage is closely related to the migration to other host pines, whereas the propagative stage is coupled to the direct cause of pine wilt. To establish expressed sequence tag (EST) database of two life cycles of B. xylophilus, subtractive EST libraries were constructed using suppressed subtractive hybridization (SSH). From 3,072 and 3,840 sequences of dispersal- and propagative-specific stage cDNA libraries, 1,927 and 2,604 clusters were generated, respectively, which were annotated by BLASTx and Gene ontology (GO). A total of 1,112 (57.7%) and 1,215 (46.7%) clusters from the dispersal- and propagative-specific stage cDNA libraries respectively had the matched BLASTx hits (E≤10-2), among which 913 (47.4%) and 960 (36.9%) were classified into three categories in Gene ontology. From GO database, some respective stage-specific genes were searched and estimated the relative transcripts level according to stages using the quantitative real-time PCR.

DPPH(l, 1-diphenyl-2-picrylhydrazyl) free radical scavenging activity assay was used to analyze antioxidant activities in 249 Korean rice landraces. Especially, red rice varieties were 13 accessions, showed very strong antioxidant activities more than 95%. Brown rice varieties were 236 accessions, among them G307 showed the highest antioxidant activity of 68%. Most of brown rice varieties showed higher activities than Chucheongbyeo as check variety. 101 accessions were distributed range of 21 - 30% and 71 accessions were distributed range of 31 -40%.

강원도 치악산 계류에서 하루살이과에 속하는 가는무늬하루살이와 무늬하루살이의 온도와 연관된 생활사 적응에 대하여 연구하였다. 하루살이 개체군의 고도분포에 따라 3개의 조사지점(상류와 중류지점: 가는무늬하루살이; 하류지점: 무늬하루살이)을 선정하였다. 채집은 1997. 2~1998. 1 동안 월 1회 실시하였고, 우화기에는 월 2회 실시하였다. 수온은 1997. 5~1998. 1 동안 시간대로 모니터링 하였다. 결과로서, 3개의 조사지점은 서로 다른 온도역(평균온도 상류: 9.39°C; 중류: 10.38°C; 하류: 12.70°C)을 나타냈다. 체장과 유충단계의 분석 결과 두 종 모두 명백히 연 1세대였고, 각 개체군은 2개의 무리(cohort)를 포함하였다. 우화는 늦은 5월부터 늦은 6월까지 일어났지만 하류로 갈수록 일렀다. 유충의 충원은 우화기(여름형)와 그 5~6개월 이후(겨울형)에 시작되었다. 이처럼 2회에 걸친 유충의 충원에 대하여 알의 휴면 또는 무성생식이 원인으로 작용하는 것으로 가정되었다. 상류와 중류에서 가는무늬하루살이의 총 적산온도는 각각 2380DD와 2668DD였고, 하류에서 무늬하루살이는 3220DD였다. 가는무늬하루살이의 경우 연평균수온이 1°C 내려감에 따라 알의 부화는 약 22일, 평균 유충성장은 약 15일 지연되는 것으로 추정되었다. 가는무늬하루살이는 냉온에 적응된 생활사 양상을 나타냈고, 다른 한국산 및 일본산 근연종과 비교하여 종내 및 종간 생활사 적응에 대하여 추가로 논하였다.

Retrospective analysis was conducted on the clinical data of 38 cases of bacterial meningitis that were proven by cerebrospinal fluid culture. Each case occurred by GBS (68.4%), Pneumococcus (15.8%), E. coli (5.3%), Streptococcus mitis (5.3%), Streptococcus bovis (2.6%), and Staphylococcus xylosus (2.6%). Compared to 28 cases with normal outcome, 10 cases who died or had adverse outcomes at hospital discharge were more likely to present with coma, seizure (before or within admission, focal, status epilepticus), require pressor or ventilator support, have initial peripheral blood leukocyte count less than 4,000/mm3 or neutrophil count less than 1,000/mm3, and have hydrocephalus or cerebral infarction by brain imaging.