• Carbon letters
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• 제11권1호
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• pp.13-21
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• 2010

Coconut shell activated carbon (CSAC) was investigated for its ability in the removal of two neutral chlorinated organic compounds, namely trichloroethylene (TCE) and dichloromethane (DCM) from aqueous solution using a packed bed column. The efficiency of the prepared activated carbon was also compared with a commercial activated carbon (CAC). The important design parameters such as flow rate and bed height were studied. In all the cases the lowest flow rate (5 mL/min) and the highest bed height (25 cm) resulted in maximum uptake and per cent removal. The experimental data were analysed using bed depth service time model (BDST) and Thomas model. The regeneration experiments including about five adsorption-desorption cycles were conducted. The suitable elutant selected from batch regeneration experiments (25% isopropyl alcohol) was used to desorb the loaded activated carbon in each cycle.

• Journal of Plant Biotechnology
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• 제3권1호
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• pp.27-31
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• 2001

New types of cytoplasmic male sterility in Brassica species would be very useful for the production of F$_1$, hybrid seeds. Leaves and stems of rapid cycling stock of B.juncea (CrGC4-3) containing Anand CMS were used as experimental materials for plant regeneration from protoplast culture. Very high plant regeneration rate (85%) was found in the Kao & Michayluk medium supplemented with 2 mg/L zeatin, 0.5 mg/L BAP, and 1 mg/L NAA when only leaf, not stem, segments were cultured. Protoplasts were isolated from leaves using mixtures of enzymes (1% Cellulycin, 0.5% Macerozyme) in 0.4 M mannitol and 50 mM $CaCl_2$.$2H_2$O. Mcrocalli induced from protoplasts were transferred to the shoot regeneration medium containing 2 mg/L BAP, 2 mg/L zeatin, and 0.5 mg/L NAA. After 60 days of initial protoplast culture, regenerated plantlets were obtained, acclimatized, transplanted into the pots, and grown up to the flowering stage.

• 한국약용작물학회지
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• 제14권6호
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• pp.367-370
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• 2006

The study was carried out to establish an improved protocol for shoot organogenesis and plant regeneration from leaf explant cultures of Scrophularia buergeriana M. with the treatment of ethylene inhibitors [silver nitrate (AgNO$_3$), aminoethox-yvinylglycine (AVG), Cobalt chloride (CoCl$_2$)]. The regenerated shoots obtained from leaf explant cultures on MS medium containing 2 mg/l BAP, The additions of AgNO$_3$. AVG and CoC1$_2$ substantially improved the shoot regeneration frequency, at the optimal concentration of 7 mg/L, 7 mg/L, and 3 mg/L respectively, The regenerated shoots could be easily rooted with 0.1 mg/L IBA treatment. The noted plants were hardened and transferred to vermiculite with a 85% survival rate where they grew normally.

• Journal of Plant Biology
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• 제35권1호
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• pp.17-23
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• 1992

Polyamine과 polyamine의 생합성 억제제가 포플라(Populus nigra var. $betulifolia{\times}Populus$ trichocarpa) 잎절편의 부정아 분화에 미치는 영향을 조사하여 다음과 같은 결과를 얻었다. Polyamine의 생합성 억제 물질인 DFMA, DFMO 및 DCHA를 배지에 각각 1mM의 농도로 처리하였을 때 포플라 잎절편의 생중량 감소와 함께 부정아의 분화율이 감소하였고 부정아의 분화되는 시기도 지연되었다. 특히, 부정아 분화에 대한 억제효과는 DCHA가 가장 강하였으며 그 다음 DFMO, DFMA의 순서로 나타났다. 한편, polyamine 생합성 억제제에 의한 부정아의 분화 억제 현상이 polyamine의 처리에 의하여 경감 내지는 상쇄되었는데 이 과정에서 spermidine이 가장 효과적으로 작용하였다. 이러한 결과들로부터 polyamine, 특히 spermidine은 포플라 잎절편의 부정아 분화시 하나의 필수적인 요소로 작용한다고 사료된다.

• 한국태양에너지학회 논문집
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• 제23권3호
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• pp.7-14
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• 2003

Absorption potential of desiccant solution significantly decreases after absorbing moisture from humid air, and a regeneration process requires a great amount of energy to recover absorption potential of desiccant solution. In an effort to develop an energy efficient regenerator, this study examines a regeneration process using hot air heated by solar radiation to recover absorption potential by evaporating moisture in liquid desiccant. More specifically, this study is aimed at finding the optimum operating condition of the regenerator by utilizing a well-established statistical tool, so-called response surface methodology(RSM), which may provide a functional relationship between independent and dependent variables. It is demonstrated that an optimization model to find the optimum operating condition can be obtained using the functional relationship between regeneration rate and affecting factors which is approximated on the basis experimental results.

• FOCUS: LIFE SCIENCE
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• 제1호
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• pp.5.1-5.3
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• 2024

The document discusses the regeneration of Partisil/Partisphere ion-exchange columns in chromatography. It mentions that column efficiency can diminish with use due to the accumulation of sample and/or mobile phase impurities at the head of the column. This can lead to a change in back pressure, lower column efficiency, and sometimes a change in selectivity. The document outlines a procedure that may restore column performance. The document also provides everyday practices to enhance the lifetime of a column. These include using only high-purity HPLC solvents and buffers, using freshly prepared mobile phases and buffers, filtering mobile phases to remove particulates, using appropriate sample clean-up procedures, using a guard column or pre-column filter, and working within the pressure and flow rate limitations of the column. For the regeneration of Partisil/Partisphere SAX, SCX, WAX, and WCX columns, the document suggests passing 20 column volumes of various mobile phases through the column. These include a buffer wash, distilled water, an acid wash, a chelating wash, a methanol wash, and a buffer for separation. The document emphasizes that not all of these wash steps are required for every column clean-up and that some chromatographers require only a combination of certain steps.

• Journal of Periodontal and Implant Science
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• 제44권1호
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• pp.13-19
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• 2014

Purpose: The purpose of this study was to retrospectively evaluate the survival of periodontally hopeless teeth that were intentionally extracted and replanted after a delay and to compare the radiographic characteristics of the survival group with those of the failure group. Methods: The clinical and radiographic data from patients who underwent delayed intentional replantation between March 2000 and July 2010 were reviewed. Twenty-seven periodontally hopeless teeth were extracted and preserved in medium supplemented with antibiotics for 10-14 days. The teeth were then repositioned in the partially healed extraction socket and followed for 3 to 21 months. The radiographic parameters were analyzed using a paired t test and the cumulative survival rate was analyzed using Kaplan-Meier analysis. Results: Seven replanted teeth failed and the overall cumulative survival rate was 66.4%. In the survival group, the amount of bone loss was reduced from 68.45% to 34.66% three months after replantation. There was radiologic and clinical evidence of ankylosis with 5 teeth. However, no root resorption was found throughout the follow-up period. In the failure group, bone formation occurred from the bottom of the socket. However, a remarkable radiolucent line along the root of a replanted tooth existed. The line lengthened and thickened as time passed. Finally, in each case of failure, the tooth was extracted due to signs of inflammation and increased mobility. Conclusions: Delayed intentional replantation has many advantages compared to immediate intentional replantation and could serve as an alternative treatment for periodontally involved hopeless teeth. However, techniques for maintaining the vitality of periodontal structures on the tooth surface should be developed for improved and predictable results.

• Journal of Periodontal and Implant Science
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• 제35권3호
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• pp.597-608
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• 2005

The aim of this study is to determine whether full-mouth disinfection therapy(FMT) in our clinical setting would show better improvement of clinical parameters than partial mouth disinfection therapy(PMT) in chronic periodontitis and aggressive periodontitis patients. Among 12 patients, 6 were treated FMT and other 6 were treated PMT. Clinical parameters were calculated 3 months and 6 months after initial therapy. 1. There were no statistically significant differences between FMT and PMT in the reduction rate of bleeding on probing after 3 months, 6 months 2. Initial probing depth was 4-6mm, the mean probing depth after 3 months was 2.2mm vs 2.5mm(FMT vs PMT), after 6 months was 2.4mm vs 2.8mm. This was significantly lower in the FMT groups. 3. Initial probing depth was ${\geqq}$ 7mm, the reduction rate of mean probing depth during first 3 months was 4.8mm vs 4.1mm(FMT vs PMT), and 3 to 6 months was 0.5mm vs 0.3mm. This was significantly larger in the FMT groups. 4. Initial probing depth was 4-6mm, the mean clinical attachment level after 3 months was 2.3mm vs 2.7mm(FMT vs PMT), after 6 months was 2.7mm vs 3.0mm. This was significantly lower in the FMT groups. 5. Initial probing depth was ${\geqq}$ 7mm, the reduction rate of mean probing depth during first 3 months was 4.0mm vs 3.0mm(FMT vs PMT), and 3 to 6 months was 0mm vs -0.1mm. This was significantly larger in the FMT groups. Although the results provided us with succeccful clinical improvement in aggressive periodontitis, further research is needed to prove its additional benefit in the treatment of chronic periodontitis

• Journal of Periodontal and Implant Science
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• 제33권4호
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• pp.673-691
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• 2003

The current interest in periodontal tissue regeneration has lead to research in bone graft, root surface treatments, guided-tissue regeneration, and the administration of growth factors as possible means of regenerating lost periodontal tissue. Several studies have shown that a strong correlation between platelet-rich plasma and the stimulation of remodeling and remineralization of grafted bone exists, resulting in a possible increase of 15-30% in the density of bone trabeculae. The purpose of this study was to study the histopathological correlation between the use of platelet-rich plasma and a bone xenograft used in conjunction with a non-resorbable guided-tissue membrane, e-PTFE, compared to a control group with regards to bone regeneration at the implant fixture site. Implant fixtures were inserted and graft materials placed into the left femur of in the experimental group, while the control group received only implant fixtures. In the first experimental group, platelet-rich plasma and BBP xenograft were placed at the implant fixture site, and the second experimental group had platelet-rich plasma, BBP xenograft, and the e-PTFE membrane placed at the fixture site. The degree of bone regeneration adjacent to the implant fixture was observed and compared histopathologically at 2 , 4, and 8 weeks after implant fixture insertion. The results of the experiment are as follows: 1. The rate of osseointegration to the fixture threads was found to be greater in the first experimental group compared to the control group. 2. The histopathological findings of the second experimental group showed rapid resorption of BBP with subsequent new bone formation replacing the resorbed BBP. 3. The second experimental group showed new bone formation in the area adjacent to the fixture threads beginning two weeks after fixture implantation, with continued bone remodeling in the areas mesial and distal to the fixture. 4. Significant new bone formation and bone remodeling was observed in both experimental groups near the implant fixture sites. 5. The rate of osseointegration at the fixture threads was greater in the second experimental group compared to the first group, and the formation of new bone and trabeculae around the fixture site occurred after the fourth week in the second experimental group. The results of the experiment suggest that a greater degree of new bone formation and osseointegration can occur at the implant fixture site by utilizing platelet-rich plasma and bone xenografts, and that these effects can be accelerated and enhanced by concurrent use of a non-resorbable guided tissue membrane.

• 한국균학회지
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• 제14권3호
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• pp.215-223
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• 1986

원형질체(原形質體)를 이용한 버섯의 육종연구(育種硏究)를 하는데 있어서 원형질체(原形質體) 재생(再生) 및 환원(還元)은 필수적인 과정이라고 할 수 있다. 식용(食用)버섯의 일종(一種)인 P. cornucopiae 노랑 느타리버섯의 원형질체(原形質體) 재생(再生)에 적합한 제조건(諸條件)에 대해서 조사한 바를 요약하면 다음과 같다. 원형질체(原形質體) 재생(再生)에 적합한 삼투압 조절제(調節劑)와 농도(濃度)는 0.6M sucrose로 MCM에서 5.21%의 높은 재생률(再生率)을 보였고, agar를 포함하지 않은 0.6M sucrose 삼투압 조절제(調節劑)나 0.6M液 sucrose+MMM 체배지(體培地)만을 overlaying한 경우에 재생률(再生率)이 높았다. 노랑 느타리버섯의 균사(菌絲) 생장(生長)을 촉진시킨 아미노산, 핵산 구성 성분의 종류(種類)와 원형질체(原形質體) 재생률(再生率)을 증가시킨 종류(種類)는 유사하며 큰 차이가 없었으나 비타민에서는 다소 다른 경향을 나타냈다. 재생률(再生率)을 증가시킨 영양원(營養源)들을 혼합했을 때 무첨가 배지 MMM에 비해 아미노산 혼합, 핵산 구성 성분 혼합에서는 재생률(再生率)이 증가했으며 비타민 혼합에서는 오히려 감소하였고 아미노산, 핵산 구성 성분, 비타민 모두가 첨가된 데서 가장 높은 재생률(再生率)을 나타냈다. 고체(固體) 배지(培地)에서 원형질체(原形質體)가 $1{\sim}2$일 배양(培養)되었을 때 광학 현미경하에서 재생(再生) 형태(形態)를 첫째, one or two directgerm tube, 둘째, bud like structure, 세째, yeast-likecell chain, 네째는 한 원형질체(原形質體)에서 direct germ tube와 yeast-like cell chain을 형성하는 형태를 관찰할 수 있었으며 $3{\sim}4$일 배양(培養)때는 균사(菌絲)가 branch를 형성하며 성장하였고 결국 완전한 균사체(菌絲體)로 되어 노랑 느타리 자실체(子實體)를 형성하였다.