• 한국식물병리학회지
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• 제13권3호
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• pp.160-166
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• 1997

전국에서 채집한 균주들 중 근권정착능력이 있는 균주를 선발하였다. 선발된 대부분의 균주들은 형광성 Pseudomonas속에 속하는 균주들이어고 이들 중 근권정착능력이 아주 우수한 B16과 V13을, 정착능력이 낮은 MC07과 X01을 시험에 공시하였다. 근권정착능력이 우수한 균주 B16과 V13은 종자 발아 초기단계에서의 증식 능력이 우수할 뿐만 아니라, 종자가 발아를 시작하여 유근이 나오는 시기에 이들의 정착밀도가 높았으며, 96시간이 지난 후에도 뿌리의 근단 부위에서 V13과 B16 균주들의 정착밀도가 높았다. 주사전자현미경(SEM)을 통하여 이들의 근권에서의 정착양상을 관찰한 결과, 정착능력이 우수한 균주들은 뿌리의 전반적인 부분에서 증식하고 근단 부위로 이동하는 것을 관찰할 수 있었다. 그러나 정착능력이 낮은 균주들은 유근의 표면에 산발적으로 흩어져 증식한 것을 볼 수 있었다.

• 대한소아치과학회지
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• 제42권4호
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• pp.319-326
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• 2015

Short root anomaly (SRA)는 매우 드문 질환으로, 교정력에 의한 치근흡수에 있어서 정상적인 치아보다 더 취약하므로 처치시에 어려움이 있다. 또한, 혼합치열기 시기에 나타나는 전반적인 SRA의 경우는 진단 또한 쉽지 않다. 초기 혼합치열기환아에서 방사선 사진만으로 전반적인 SRA를 예측하기 어렵지만, 가족력이나 관련 전신질환, 또는 구강 내 다른 치아이상(tooth anomaly) 등의 요소가 있는 경우, SRA를 염두에 두어야 한다. 본 증례는 전악에 걸쳐SRA를 보이는 초기 혼합치열기 환아의 교정적 처치를 다루었다. 비록 국소적인 치아 상실이 있었으나 적절한 교정적 배열을 통해 더 이상의 과도한 치근흡수 없이 치료를 마무리 하였으며, 비교적 양호한 치료 결과를 얻었기에 이를 보고하고자 한다. 결론적으로, SRA 환자에서도 교정 치료가 가능하며, SRA가 예측되는 혼합치열기 환아에서 치근 흡수나 치아상실과 같은 합병증이 나타나지 않도록 특히 주의를 기울여야 한다.

• 구강회복응용과학지
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• 제23권1호
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• pp.85-93
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• 2007

The purpose of this study was to evaluate the microleakage of root-end filling material filled in blood contaminated root-end cavity and self-etching adhesive placed over blood contaminated resected root apices without root-end preparation. Extracted, human maxillary incisors, canines and mandibular premolar were randomly divided into four groups of 15 teeth each. After canal preparation, resection of the apex and root-end preparation, MTA and IRM were filled in the root-end cavity (A and B group). After canal preparation and resection of the apex, Clearfil SE Bond and Prompt L-Pop were applied over the contaminated root-end surfaces (C and D group). The roots were then subjected to 15cm of water pressure to simulate periapical microleakage stress. Data were analyzed using one-way ANOVA. The results were as follows : 1. All groups showed a tendency of decreasing microleakage in process of time after 2weeks later except IRM group. 2. After 2 weeks and 1 month, MTA group showed less microleakage significantly than other groups(p<0.05). After 2 months, Prompt L-Pop group showed less microleakage significantly than other groups(p<0.05). 3. After 9 months, there were no significant differences among four groups(p>0.05). Thus it is considered that apical sealing using adhesives system without root-end preparation is good method in endodontic surgery.

• 대한치과의사협회지
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• 제58권10호
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• pp.604-614
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• 2020

Objective: The purpose of this study was to analyze the Cone-beam computed tomograghy(CBCT) scan of endodontically treated maxillary first molars and investigate how second mesiobuccal (MB2) canal is treated, how the prognosis of mesiobuccal (MB) root is different compared to other roots and the prognosis factor on apical periodontitis. Methods: Subjects were endodontically treated maxillary first molars whose were collected from CBCT scans taken from January 2018 until December 2019. A total of 525 maxillary first molars were analyzed by an endodontist to determine the presence of the MB2 canal, the quality of the root canal filling, and the presence of apical periodontitis. The chi square test and Fisher's exact test was used to examine the relationship between each variable. Results: MB2 canals were found in 46.3%, of which 76.5% were not treated. The more main canal of mesiobuccal root (MB1 canal) was well filled, the more significantly MB2 canal was well filled (p<0.001). The apical periodontitis of MB root was not related to the filling quality of MB1 canal (p=0.370) and was related to the filling quality of MB2 canal (p=0.004). The apical periodontitis of MB root was related to the quality of canal filling of MB2 canal and the apical periodontitis of DB and P root. Conclusions: It was found that the majority of MB2 canals were not treated. The apical periodontitis of MB root was analyzed to be related to the quality of canal filling of MB2 canal. The apical lesion of the MB root was not correlated with the treatment of the MB1 canal, but it was significantly related to the quality of filling of MB2 canal.

• 생물환경조절학회지
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• 제7권2호
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• pp.139-143
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• 1998

지중가온시설을 이용한 고구마뿌리혹선충(Meloidogyne incognita Chitwood) 방제를 위하여 지하 20cm 깊이의 최저지온을 각각 30. 40, $50^{\circ}C$ 가온구 및 관행의 무지중가온구로 설정하고 담수구와 무담수구로 나누어 8월 1일부터 8월 5일까지 5일간 가온한 결과, 담수구의 경우 지온 4$0^{\circ}C$에서 5일간, 무담수구의경우 지온 $50^{\circ}C$에 5일간 지중가온처리한 구에서 생존한 유충이 발견되지 않아 선충밀도를 경제적 피해수준 이하로 유지할 수 있을 것으로 사료되었다. 지중가온으로 토양내 OM. P$_2$ $O_{5}$, Ca, Mg함량과 EC는 시험전 토양에 비하여 감소하였는데, 특히 담수처리에서 EC가 현저히 저하하였다.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.160-163
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• 2001

In order to investigate the role of bacterial chemotaxis in root colonization, the chemotaxis potential of bacteria isolated from spinach roots was compared with that of bacteria from nonhizosphere soil, with reference to the plant age (1,000 isolates), soil moisture conditons (1,400 isolates), and part of the root (200 isolates). The % CT (% occurrence of chemotaxis (+) isolates among total bacterial isoltes) of the root isolates significantlyfluctuated during the plant growth period, reaching a maximum after 10-15 days of growth. At this time period, the maximum % CT for the root isolates was around 70-80% CT under a soil moisture 50% WFP (% volume of water-filled pores in total soil pores), and then gradually reduced with an increasing % WFP. The results of the chemotaxis potential of each of the 100 islates from the spinach roots and nonrhizosphere soil under various % WFP demonstrated that the % CT of the root isolates were significantly higher than those of solates from the nonrhizosphere soil under a wide range of soil moisture content (35-80% WFP). Furthermore, the % CT value (80%) from the upper root was significantly higher than tht (55%) from the lower root. Compared with the % CT values of the roots, the values from the nonrhizosphere soil did not significantly vary relative to the plant age of % WFP. These results indicate that chemotaxis would appear to be a major factor in bacterial root colonization.

• 한국환경과학회지
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• 제1권2호
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• pp.145-155
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• 1992

The effect of various supplies of lead singly and in combination with aluminium on growth and chlorophyll biosynthesis was investigated in 7-day-old Vigna anguluris seedlings. Expose to 50 $\mu$N Pb or more drastically reduced root elongation rate. Significant depressions in root growth was observed within 1 day and no recovery of growth was seen over the duration of treatment period. Root elongation decreased depending on the Pb concentrations. Root growth inhibition was stronger than shoot growth inhibition. The initiation of lateral roots appeared to be more sensitive to Pb than the growth of main roots. Inhibition of root and shoot elongation by Pb was lessened by combined exposure of Pb and Al, suggesting that the presence of AA reverse the inhibitory effect of Pb alone. With the histochemical sodium rhodizonate method the rate of Pb uptake was dependent on the Pb concentration and exposure time of the roots to Pb salts. Pb was first deposited on the root surface and then translocated radially in the root cap cells. During a longer Pb administration (up to 72 h) Pb penetration was nonuniform, with accumulation within the cortex or endodermis. There was drastic reduction in chlorophyll content by Pb. The Pb inhibition of chlorophyll synthesis was concentration dependent. 5-Aminolevulinic acid dehydratase (ALAD) activity exhibited distinct inhibition from control. Reduction in chlorophyll content was accompanied by proportional changes in ALAD activity. Chlorophyll content and ALAD activity were less affected by combined exposure of Pb and Al, suggesting that Al has a protective effect against the inhibiting action of Pb on photosynthetic activity.

• Asian-Australasian Journal of Animal Sciences
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• 제20권5호
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• pp.725-732
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• 2007

The effects of supplementing Gamba grass (Andropogon gayanus) with varying levels of hay from cassava (Manihot esculenta Crantz) and dried cassava root chip on growth and diet digestibility were studied using local male goats with an average initial body weight of 14.0 kg. Thirty-two animals were allocated to a completely randomized $2{\times}2$ factorial design with eight animals per treatment. The factors were two levels of cassava hay (25% and 35% of an expected dry matter (DM) intake of 3% of body weight) and cassava root chips (0 or 1% of body weight) on an individual basis with grass offered ad libitum. Another four animals were assigned to a $4{\times}4$ Latin square design to study digestibility, and were given the same four diets as in the growth experiment. Total DM intake was significantly higher in the group fed diets with cassava hay and root while the DM intake of Gamba grass was not significantly different between treatments. The supplementation with cassava hay and root increased the apparent digestibility of DM, organic matter and N and resulted in a higher N-retention. The apparent digestibility of neutral detergent fibre and acid detergent fiber was not affected significantly. The average daily gain of animals fed diets supplemented with both cassava hay and root was significantly higher than for the animals supplemented with cassava hay alone. The highest daily gain recorded was 70 g/day. In conclusion, supplementing a basal diet of Gamba grass with cassava hay and root chips improved DM intake, digestibility, N-retention and weight gain. In order to minimize the waste of cassava hay, the inclusion level of cassava hay can be recommended to be 25% of expected DM intake, which would give acceptable intake and growth performance when cassava root is included in the diet.

• 한국음향학회지
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• 제21권3호
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• pp.304-309
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• 2002

LSP (Line Spectrum Pairs) 파라미터는 음성코덱 (codec)이나 인식기에서 음성신호를 분석하여 전송형이나 저장형 파라미터로 변환되어, 주로 저전송률 음성부호화기에 사용된다. 그러나 LPC (Linear Predictive Coding) 계수를 LSP로 변환하는 방법이 복잡하여 계산시간이 많이 소요된다는 단점이 있다. 기존의 LSP변환 방법 중 음성 부호화기에서 주로 사용하는 실근 (real root)방법은 근을 구하기 위해 주파수 영역을 순차적으로 검색하기 때문에 계산시간이 많이 소요되는 단점을 갖는다. 본 논문에서 기존의 실근 방법과 비교 평가한 알고리즘은 첫 번째 검색 대역에 멜 스케일 (met scale)을 사용하였고, 두 번째는 LSP 파라미터의 분포 특성을 조사하여 이를 토대로 검색구간의 순서와 검색간격을 달리 하였다. 실험결과, 기존의 실근 방식에 비하여 두 가지 방식 모두가 변환시간의 47% 이상이 감소되는데 반하여 동일한 근을 찾음을 알 수가 있었다.

• 한국건축시공학회지
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• 제11권2호
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• pp.189-199
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• 2011

도심지 환경 개선을 위한 인공지반녹화(옥상녹화 등)사업의 확대 보급을 위해서는 옥상부 구조체의 장기적 안정성을 보증할 수 있는 안전한 방수방근층을 구성하여야한다. 따라서 인공지반 녹화용 방수방근층은 식물 뿌리의 침입으로부터 안전해야 하며, 녹화부의 잔류수 및 침체수 등에 대해 장기적으로 수밀해야 하며, 식물 성장에 필요한 비료 등의 화학물질 및 기타의 화학성분에 장기적으로 안전해야 하며, 시공 시에 발생하는 각종 공구류, 설비류, 가설물에 의해 손상되지 않아야 하고, 식재 및 토심의 하중, 설비류의 하중에 의해 손상되지 않는 종합적 성능이 요구된다. 이에 본 연구에서는 옥상녹화 현장의 환경 조건을 대상으로 방수방근층의 환경 성능 지표를 설정하였고, 이와 관련한 방근성능, 수밀성능, 내움패임 저항성능, 충격저항성능, 내화학성능을 방수방근층의 요구 성능으로 정하였으며, 그와 관련한 평가 방법을 제시하고, 실무적인 검증 시험을 통하여 복합 방수방근층의 성능 평가 시스템을 제안하였다.