• 식물조직배양학회지
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• 제27권2호
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• pp.117-123
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• 2000

애기장대 (Arabidopsis thaliana) 생태종 'Columbia'의 잎 절편 배양시 부정근, 모용 및 캘러스 형성에 미치는 polyamine의 역할을 알아보고자 putrescine, spermidine, spermine, cyclohexylamine (CHA) 및 methylglyoxal-bis(guanylhydrazone) (MGBG)의 영향을 조사하였다 애기장대 잎 절편을 부정근 (0.1 mg/L NAA), 모용 (2.0 mg/L NAA) 및 캘러스 (10.0mg/L NAA)를 형성하는 MS배지 각각에 putrescine, spermidine 및 spermine을 1∼100 mg/L 처리하였다. Polyamine 처리시 부정근 형성구에서는 부정근과 함께 모용이 형성되었으며, 모용 형성구에서도 모용과 함께 캘러스가 형성되었다 또한 CHA와 MGBG를 1∼100mg/L 범위에서 처리한 결과 CHA는 부정근 형성구에서 다소 부정근이 증가시켰으나 모용이나 캘러스 형성구에는 영향을 미치지 않았다. MGBG는 부정근 모용 및 캘러스 모두를 억제하였고 모용 형성구에서는 고농도에서 부정근을 형성시켰다.

• 한국초지조사료학회지
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• 제14권4호
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• pp.324-330
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• 1994

The objective of this study is to obtain the basic data for investigating the potentiality of continuous utili~ation (first cutting in the late fall and regrowth yield in next spring) of forage rape seeded in fall. Fresh yield and the content of nitrogenous compound in leaves and roots were measured during a growth period. Fresh yield accumulation was very low between the late fall(470kg/10a) and the early regrowth period( 1.070kg /IOa). Total nitrogen content in leaves until the wintering period was decreased from 4.71% to 3.70%. while that in roots slightly increased during this period. The highest content(4.84%) in roots was observed in the early regrowth period, and then rapidly decreased as growth advanced. Protein-N was the largest pool of nitrogenous compound in leaves and roots through entire growth period, Its content in leaves decreased until the wintering period (Feb. 4), and then increased until the bolting stage(Apr. 10). Protein-N in roots highly accumulated from the late fall(11.1mg/gDM) to the early regrowth period(l6.9mg/gDM), and then decreased until the early tlowering stage. The content of amino acid-N in leaves showed a little change with a range from 5.7 to 8.5mgIgDM during entire growth period, while that in roots rapidly decreased from early regrowth period. The content of $NO_3$-N decreased from 7.0 to 4.3mglgDM in leaves, while increased from 0.9 to 2.3mg/gDM in roots from the late fall to the wintering period. 7he content of $NH_4$-N was lower and less varillble than other nitrogen compound during entire growth period. The results clearly showed that protein-N was the main storage form and highly accumulated in roots of overwintering forage rape.

• Applied Biological Chemistry
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• 제39권6호
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• pp.517-520
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• 1996

재배도라지 3년근과 24년근을 SDE방법으로 추출하여 본 결과 휘발성분은 3년근에서 54.71 mg%, 24년근에서 80.01 mg%가 각각 포집되었다. 이들을 각각 GC/MS(TIC)로 분석한 결과 3년근에서는 24종 24년근에서는 28종의 휘발성분이 확인되었다. 특히 hexanol, trans-2-hexenol, nonanal의 휘발성분은 3년근에 비해 24년근에서 10배 이상 검출되었다. 도라지 24년근의 휘발성분을 GC/MS로 동정한 결과 주요성분으로 hydrocarbon류 10종, alcohol류 8종, aldehyde류 10종, ester류 5종, acid류 6종, 기타 1종의 휘발성분이 검출되었다. 도라지 휘발성분의 종류와 함량은 3년근보다 24년근에서 높게 나타나는 것으로 사료된다.

• Journal of Forest and Environmental Science
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• 제10권1호
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• pp.8-24
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• 1994

수목(樹木)의 뿌리는 수목(樹木)의 생장(生長)과 토양(土壤)의 구조개선(構造改善)에 밀접한 관계가 있음에도 불구하고 지하부(地下部)에 위치하고 있으므로 연구가 미진한 상태이다. 따라서 각 수종(樹種)의 근계(根系)의 발달상태를 파악하는 것은 그 수종(樹種)의 특성 파악과 뿌리가 지표고정(地表固定)에 미치는 영향을 파악하는데 기초자료로 활용할 수 있다. 본 연구에서는 강원도(江原道) 소나무림(林)의 특성을 파악하기 위한 기초연구의 일부로서 일차적으로 강원대학교(江原大學校) 구내(構內) 소나무림(林)의 근계(根系) 형태(形態) 및 분포(分布)에 대하여 규명하였다. 5개의 공시목(供試木)에 대해 조사한 결과 뿌리의 형태(形態)는 수평근(水平根)이 잘 발달되어 있었다. 뿌리의 분포(分布)에 있어서 크기별로는 세근(細根)은 대부분이 점재(点在)(+)하고 있었음, 태근(太根)은 0.2cm가 대부분이었다. 깊이별로는 태근(太根), 세근(細根) 모두가 10~30cm에서 60~70% 이상 집중되었으며, 태근(太根)은 주로 0.9cm 이하였고, 세근(細根)은 대부분이 점재(点在)(+)하고 있었다.

• Restorative Dentistry and Endodontics
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• 제43권2호
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• pp.16.1-16.9
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• 2018

Objectives: Understanding the reason for an unsuccessful non-surgical endodontic treatment outcome, as well as the complex anatomy of the root canal system, is very important. This study examined the cross-sectional root canal structure of mandibular first molars confirmed to have failed non-surgical root canal treatment using digital images obtained during intentional replantation surgery, as well as the causative factors of the failed conventional endodontic treatments. Materials and Methods: This study evaluated 115 mandibular first molars. Digital photographic images of the resected surface were taken at the apical 3 mm level and examined. The discolored dentin area around the root canal was investigated by measuring the total surface area, the treated areas as determined by the endodontic filling material, and the discolored dentin area. Results: Forty 2-rooted teeth showed discolored root dentin in both the mesial and distal roots. Compared to the original filled area, significant expansion of root dentin discoloration was observed. Moreover, the mesial roots were significantly more discolored than the distal roots. Of the 115 molars, 92 had 2 roots. Among the mesial roots of the 2-rooted teeth, 95.7% of the roots had 2 canals and 79.4% had partial/complete isthmuses and/or accessory canals. Conclusions: Dentin discoloration that was not visible on periapical radiographs and cone-beam computed tomography was frequently found in mandibular first molars that failed endodontic treatment. The complex anatomy of the mesial roots of the mandibular first molars is another reason for the failure of conventional endodontic treatment.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제17권2호
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• pp.185-188
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• 2010

In this note the distribution of roots of cubic equations in contrast to 0 is given, which is useful to discuss eigenvalues for qualitative properties of differential equations.

• 대한수학회지
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• 제32권1호
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• pp.61-76
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• 1995

Much research has been done to estimate the magnitudes of the changes of the roots from the perturbed polynomials. For more information and references on such work, see [2, 4, 5, 10, 17].

• Korean Journal of Mathematics
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• 제9권1호
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• pp.67-73
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• 2001

For some equation related with exponential function, we seek roots and find the properties of the roots. By using the relation of the roots and attractors, we find a region in the basin of attraction of the attractor at infinity for Newton's method for solving given equation.

• Journal of the Korean Data and Information Science Society
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• 제16권1호
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• pp.127-136
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• 2005

We will derive some results on the perturbation of roots using Newton's interpolation formula. And we also compare our results with those obtained by Ostrowski by giving some numerical experiments with Wilkinson's polynomials.

• The Korean Journal of Ecology
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• 제17권2호
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• pp.113-119
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• 1994

Vertical and horizontal distribution and seasonal changes of fine roots as well as inorganic nitrogen content in soil were determined in Quercus mongolica and Quercus acutissima stands in Mt. Taemosan, Seoul. The vertical distribution of fine rooth phytomass showed a power-functional decrease as descending soil depth. Fine root phytomass was 170 g $DM/m^2$(46%) and 225 g $DM/m^2$(47%) in top soil of 5 cm depth, and 370 g $DM/m^2$ and 480 g $DM/m^2$ from soil surface to 50 cm depth in Q. mongolica and Q. acutissima stands, respectively. Fine roots in relation to the distance from the nearest tree were evenly distributed horizontally in both stands. Fine roots phytomass in top soil of 5 cm depth reached a peak in June, and thereafter decreased gradually in both stands. Patterns of seasonal changes in fine root phytomass were closely related to inorganic nitrogen and moisture content.