• Restorative Dentistry and Endodontics
• /
• 제18권2호
• /
• pp.341-356
• /
• 1993

In the prevention of root surface caries, antimicrobial therapy for the control of subgingival and supragingival plaque is seriously considered as a long term suppression of pathogenic microflora. Recently, varnishes containing antimicrobial agents have been developed to control the supragingival microflora. The purpose of this study was to determine the antimicrobial effects of 20% chlorhexidine varnish and 2.6% silane fluoride varnish with sealant. In clinical experiments, 12 subjects were selected from the periodontally treated patient and divided into 3 groups. After a dental prophylaxis, the subjects were treated with single application of placebo varnish (group I), 20% chlorhexidine varnish (group II), and 2.6% silane fluoride varnish (group III). Root surface plaque samples were taken before (baseline) and one, two, four, and 8 weeks after the treatments. Microbiological examinations of root surface plaque were performed with culture study and indirect immunoflorescence (I.I.F.) study, and immunological examination of gingival crevicular fluid antibody titers was performed with ELISA study. The results were as follows: 1. Pathogenic microflora on the root surface including S. mutans, S. sanguis, S. mitis, A. naeslundii, A. viscosus were 24 - 37% on I.I.F. study. 2. S. mutans, S. sanguis, S. mitis, A. naeslundii, A. viscosus of the root surface plaque was significantly reduced from 1 week to 8 weeks after antimicrobial varnish treatment, but showed generally increasing tendency in control group. 3. Gingival crevicular fluid antibody titers were significantly reduced from 1 or 2 weeks to 4 weeks after antimicrobial varnish treatment.

• Journal of Ginseng Research
• /
• 제28권1호
• /
• pp.67-70
• /
• 2004

인삼 근부병의 생물학적 방제를 위해 인삼 재배토양으로부터 분리된 길항미생물 Bacillu subtilis B-4228을 사용하여 방제효과를 검정하였다. 공시 균주 B-4228과 C. destructans의 대치배양결과, C destructans의 균사가 비정상적인 형태로 팽창하였으며 강한 생장억제력을 보였다. C. destructans에 의해 오염된 이병토를 이용한 pot시험결과, 건전근율이 무처리구에서 20%였으나 공시 균주 B-4228의 처리구는 82%로 높게 나타났고, 이병율(개체 인삼에 대한 뿌리썩음 이병정도의 총합비율)은 무처리의 경우 50.4%였으나 공시 균주 B-4228의 처리구는 6.0%로 낮았다.

• 대한소아치과학회지
• /
• 제38권4호
• /
• pp.399-406
• /
• 2011

영구치의 외상성 손상은 전체 외상 환자 중 높은 빈도로 발생하며 사고의 대부분은 치근이 미완성되어 있는 시기에 발생하여 치수, 치주인대, 치조골, Hertwig 상피 근초(HERS)에 다양한 영향을 주게 된다. 손상 정도에 따라 치수의 완전한 재혈관화, 근관 석회화, 근관내 치조골 함입 등의 다양한 치유 양상을 나타내며, 치근단의 성장 정지 및 치수 괴사로 인한 염증성 치근 흡수 등의 합병증을 나타낼 수 있다. 본 증례에서는 미성숙 영구치 치근단을 가진 세 환아에서 외상에 의한 Hertwig 상피 근초의 손상으로 발치와 기저부에 존재하는 치근막 세포와 골세포의 치수강내로의 증식으로 인해 치근 발육 정지 및 근관내로의 치조골 함입을 나타내어 보고하고자 한다. 외상 후 Hertwig 상피 근초의 손상에 의한 근관내로의 치조골 함입 치유 양상은 치수는 정상적인 기능을 하는 것으로 생각되며, 유착 등의 합병증이 동반되지 않는 경우 특별한 치료를 필요로 하지 않으므로 감별 진단이 요구되며, 외상 받은 치아의 치료시 Hertwig 상피 근초에 대한 부가적인 외상을 가하지 않도록 주의해야 한다.

• 대한수학회지
• /
• 제57권5호
• /
• pp.1119-1133
• /
• 2020

In this paper, we derive an upper bound for the distance from a point in the immediate basin of a root of a complex polynomial to the root itself. We establish that if z is a point in the immediate basin of a root α of a polynomial p of degree d ≥ 12, then ${\mid}z-{\alpha}{\mid}{\leq}{\frac{3}{\sqrt{d}}\(6{\sqrt{310}}/35\)^d{\mid}N_p(z)-z{\mid}$, where N_p is the Newton map induced by p. This bound leads to a new bound of the expected total number of iterations of Newton's method required to reach all roots of every polynomial p within a given precision, where p is normalized so that its roots are in the unit disk.

• 한국조경학회지
• /
• 제31권5호
• /
• pp.1-10
• /
• 2003

The purpose of this study was to verify the shore margin protection effect of a root system developed from direct sticking of Salix gracilistyla Miq., focusing on the reinforcement of soil shear strength. The materials were 20cm long sticks whose average diameter and weight were 7.52mm and 14.58g respectively, and sandy loam(Sand 60.36%, Silt 28%, Clay 11.64%), whose maximum dry weight(${\gamma}$$_{dmax}$) was 1.59gf/㎤ at the water ratio( $W_{opt}$) 13.8%. The direct shearing test(KS F 2343) was applied to cylindric columms(diameter 132mm) of pure soil and two years old root reinforced soil. At each condition of vertical stress, 10N/$ extrm{cm}^2$, 14.41N/$\textrm{cm}^2$ and 18.82 N/$\textrm{cm}^2$, five soil+root columns were sheared. After shear tests, the root area ratio and soil moisture on the shear plane were measured. The results of this research were as follows: 1. The average of root area ratio was 1.86% and the soil moisture 14.67%. 2. Two years old root system was found to increase the soil shear strength of pure soil in terms of Cohesion(C) and Inner friction Angle($\phi$) as follows. 3. The relationship between root area ratio and the increased shear strength can be presented with the following equation, $\Delta$S ≒ 0.33ㆍ TrㆍAs/A $\Delta$S : Increased Shear Strength Tr : Average Tension Strength of Root, Ar/A : Root Area Ratioioage Tension Strength of Root, Ar/A : Root Area Ratio

• Journal of Plant Biology
• /
• 제36권1호
• /
• pp.75-81
• /
• 1993

Ginseng (Panax ginseng C.A. Meyer) hairy root transformed with Agrobacterium rhizogenes (strain A4) was examined cytogenetically and histologically to assess its characteristics. The optimum growth of hairy root obtained in hormone-free MS medium (sucrose 30 g/L, pH5-6) for long period cultures. All hairy root strains (HB1, HB2, HB3) had the 2n diploid number (2n=48) of chromosomes in root tip cells. There were no alteration in chromosome structure except in one cell of HB3 strain. Results of SDS-PAGE showed a few difference in pattern and number of bands between normal and hairy root of ginseng. The root anatomy of normal root and hairy root differed each other. The hairy root had a clearly defined vascular strand, and the morphology of cortical cells were disorganised with large intercellular spaces.

• 한국응용곤충학회지
• /
• 제20권4호
• /
• pp.223-227
• /
• 1981

These experiments were conducted to investigate the nematicidal effects of the insecticides, Mocap(O-Ethyl-S, S-dipropyl phosphorodithioate), Carbofuran(2,3-Dihydro-2,2-dimethyl benzofuranyl ethyl carbamate), Terbufos (S-tert-buthylthio methyl O,O-diethyl phosphordithioate) and their mixtures (Mocap+carbofuran, Mocap+Terbufos, Carbofuran+Terbufos) on growth of 2year-old ginseng, Panax ginseng C.A. Meyer, and the control of root-knot nematodes. There was no evidence of plant injury from insecticide treatment of ginseng, although the rate of emergence of the treated ginseng was slightly inhibited. The insecticide treatments showed no of-flavor of ginseng plant. Terbufos and Mocap provided heifer confrol of the root-knot nematodes than carbofuran alone and their mixtures. Mixtures of the insecticides showed antagonisitic effect to the root-knot nematodes.

• 아시안잔디학회지
• /
• 제24권2호
• /
• pp.138-144
• /
• 2010

본연구는효모균(Saccharomyces sp.)과유산균(Lactobacillus sp.)을 포함하는 미생물배양액에 기능성성분이 포함하는 기능성비료의 시비가 크리핑벤트그래스의 잔디품질과 생육에 미치는 영향에 대해 조사하였다. 처리구는 비료의 종류에 따라 무처리구(NF), 대조구(CF), 미생물배양액(MO; CF+MO),철 함유 미생물배양액(MO-Fe; CF+MO-Fe), 그리고 황함유 미생물배양액(MO-S; CF+MO-S)였다. 시험 전후 토양분석결과, pH는 시험 후에 전보다 모든 처리구에서 약간 증가하였고, 시험 종료 후 처리구간의 토양화학성은 비슷하여 공시비료의 시비는 토양환경에 거의영향을 미치지않았다. 잔디생육 조사결과, 엽색지수와 엽록소지수는 무처리구와 비교할 때, 관행구와 처리구에서 높았고, 관행구와 처리구들 사이에는 조사시기별 변화경향은 비슷하나 MO처리구에서 약간 높게 나타났다. 잔디뿌리는 MO와 MO-Fe에서 더 길었다. 잔디의 지상부와 지하부 생육을 조사결과, 지상부에서는 MO와 MO-S가, 지하부에서는 MO와 MO-S가 관행구보다 높았으며, MO처리가 NF와 CF보다 각각 26%와 6%증가하여 MO처리가 잔디생육에 가장 효과적이었다. T/R ratio는 모두 무처리구보다 증가였으나 처리구별 차이는 나타나지 않았다. 잔디 지상부 지하부의 무기성분함량을 CF와 비교할 때, 지상부에서는 CF보다 MO, MO-Fe 및 MO-S 처리구에서 질소와 인 함량 증가하였고, 지하부에서는 인 함량이 증가하였다. 본 연구 결과, 유산균과 효모균의 처리는 크리핑벤트그래스의 뿌리생육과 양분흡수를 촉진하여 잔디품질과 성장을 향상시키는 잔디성장촉진 기능이 있는 비료임을 알 수 있었다.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.231-231
• /
• 2017

Drought limits rice production under upland condition. This study quantified the effect of rhizobacteria inoculation on rice root system developmental response to drought and its role in maintaining high soil water use, and dry matter production under drought using NSIC Rc192 (rainfed lowland rice variety). The source of inoculant was Streptomyces mutabilis, a recently isolated rhizobacteria containing plant growth promoting compounds such as ACC deaminase, indole-3-acetic acid and phosphatase (Cruz et al., 2014, 2015). In the first experiment, pre-germination inoculation of seeds with S. mutabilis significantly increased the shoot and root (radicle) length as well as root hair lengths, relative to the non-inoculated control. In the second experiment, rice plants inoculated with S. mutabilis and grown in rootbox with soil generally had greater total root length under drought regardless of the timing of inoculations, relative to the non-inoculated control. Consequently, improved root system development contributed to the increase in soil water uptake under drought and thus, dry matter production. Among inoculation treatments, one-time inoculation of S. mutabilis either at pre-germination or pre-drought stress at 14 days after sowing (DAS), had significantly greater shoot dry matter production than three-time inoculation at pre-germination, at thinning (3 DAS) and at pre-drought (14 DAS). This study demonstrated the effectiveness of rhizobacteria (S. mutabilis) containing growth promoting compounds for enhancing drought dehydration avoidance root traits and improving the growth of rice plants under drought condition.

• 대한치과의사협회지
• /
• 제49권11호
• /
• pp.660-669
• /
• 2011

Er: YAG laser irradiation utilizing the newly developed RCLase side-firing spiral tip was used for the cleansing of root canals following their bio-mechanical preparation with ProTaper Ni-Ti files. The distal and palatal roots of 20 freshly extracted molar teeth were instrumented to size F3 with ProTaper files. In the experimental group (10 teeth) the pulp chamber and the root canals were filled with EDTA 17% and the root canals were lased for 30 s using the Er: YAG laser irradiation at 600 mJ per pulse and a frequency of 12 Hz. In the control group (10 teeth) the root canals were not lased. Scanning electron microscope analysis showed clean wall surfaces of the lased root canals with open dentinal tubules, free of smear layer and debris. In the scanning electron microscope photographs of the walls of the non-lased root canals a considerable amount of debris could be detected. It appears that an efficient cleansing of the root canal system can be achieved by using the Er: YAG laser irradiation with the RCLase Side-firing Spiral Tip following bio-mechanical preparation of the root canal with Ni-Ti Taper files.