• Restorative Dentistry and Endodontics
• /
• 제46권2호
• /
• pp.19.1-19.12
• /
• 2021

Objectives: The purpose of this study was to conduct a systematic review and meta-analysis of in vitro studies regarding the effectiveness of reciprocating and rotary instrumentation on microbial reduction in root canals. Materials and Methods: PubMed, Scopus, Web of Science, the Cochrane Library, and the gray literature were searched through December 2019. Studies comparing the influence of reciprocating and rotary instrumentation on the removal of microorganisms from root canals that quantified the antimicrobial effect were included. Data extraction was completed using a systematic form for data collection. The risk of bias of the studies was evaluated. Standardized mean differences (SMDs) and confidence intervals (CIs) were calculated using a random effects meta-analysis. Results: Seventeen in vitro studies were included in this systematic review, of which 7 provided adequate data for inclusion in the meta-analysis. Both reciprocating and rotary systems were similarly effective in reducing the microbial load in infected root canals (SMD [95% CI], 0.0481 [-0.271, 0.367]). Three studies showed a low risk of bias, whereas most of the studies (82%) presented a medium risk. Conclusions: Although both techniques decrease the microbial content (with reductions of 23.32%-88.47% and 23.33%-89.86% for reciprocating and rotary instrumentation, respectively), they are not able to provide complete disinfection of root canals.

• KSBB Journal
• /
• 제11권4호
• /
• pp.411-419
• /
• 1996

본 연구에서는, 최근 들어 관심의 대상이 되어 의 품 산업에 응용의 수가 늘고 있는 cyclodextrin을 이용하여 세포밖으로 배출된 식물세포 2차 대사물질을 신속히 포획하여 생산수율을 증대시키고자 하였다. 실험결과 양귀비 현탁배양에서 a-, y-cyclodex trin보다는 ${\beta}$-cyclodextrin이 benzophenan-thridine alkaloid를 생산하는데 더 효과적업을 알았다. 이때 ${\beta}$-cyclodextrin의 optimum concentration이 존재하였는데, 그 농도는 현탁배양배지의 1.5% (w/v) 부 근에서였다. 고체 배지에서 ${\beta}$-cyclodextrin의 첨가는 sangumarme의 생산성을 control의 경우보다 약 4 40배(포함), 약 17배(살포) 정도 증가시켰다. ${\beta}$-cyclodextrin은 현탁배양 배지의 수용액상에서 세포 외로 배출된 alkaloid를 신속히 포획하여 inclusion complex를 형생함으로써 product의 배출을 촉진하여 결과적으로, product pattern을 변화시켜 줌으로 써 생산과 분리가 통시에 이루어질 수 있는 연속공정의 가능성을 확인시켜주었다. 또한 $\beta$cyclodex trin 1.5%(w/v)을 첨가시기를 달리하여 실험한 결과 배양초기에 넣어주는 것이 효과적이었으며, 이때 ${\beta}$-cyclodextrin은 세포성장에 미치는 영향이 없음을 확인하였다. ${\beta}$-cyclodextrin에 의한 benzophenan­t thridine alkaloid의 엄청난 생산 중대 효과는 1) In­c clusion complex 형성에 의한 안정성 증대뿐만 아니라 2) elicitor로서의 역할 등의 복합적 인 요인을 생 각해 볼 수 있는데 2)의 경우에 대한 실험을 세포와 ${\beta}$-cyclodextrin간의 직접적인 접촉을 시키지 않고 해본 결과 미세한 영향을 나타내었으므로 elicitation 의 경우를 완전히 배제한다고 할 수 없었다. 그러나 uv에 의한 inclusion complex의 확인이 1)의 경우를 확인하여 주었으므로 본 실험에서 ${\beta}$-cyclodex­t trin의 역할은 inclusion complex에 의한 생산성 증대라 할 수 있다.

• 한국염색가공학회:학술대회논문집
• /
• 한국염색가공학회 2011년도 제44차 학술발표회
• /
• pp.35-35
• /
• 2011

The design and preparation of novel dye rotaxanes have gained much interest recently, since such structure usually exhibits peculiar spectral and optical changes. In spite of the promising results to date, increasing pressure remains to develop novel supramolecular structures based on stimuli-responsive systems. This presentation covers the study of inclusion complexes of cyclodextrins and various chromophores, with an emphasis on our most recent outcome of anisotropic hydrogel. In this system, physical gelation prepared from simple mixture of CD and a azo dye is completed through specific host-guest interaction. The obtained hydrogel exhibits respective morphological transitions based on supramolecular assembly and dissociation, leading to either precipitation or a sol-to-gel transition. It can identify different classes of metal ions, and, among them, naked-eye differentiation of lead ion is possible due to the coordination-induced unthreading of dye molecules. Accompanying structural changes were verified by numerous characterization techniques, including 2D-ROESY, HR-MAS, UV-Visible absorption, small-angle X-ray scattering, and induced circular dichroism measurements. Such properties discussed here will find useful in analytical applications, such as metal ion sensing and removal applications.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
• /
• pp.120-123
• /
• 2003

Immobilization behavior of methyl tert-butyl ether (MTBE) by various cyclodextrins(CDs) was studied to investigate the feasibility of MTBE removal using cyclodexrins. Even though MTBE has relatively low hydrophobicity and higher polarity compared to other organics, it was effectively immobilized by CDs. The immobilization isotherms was shown as a type of Freundlich isotherms, and the immobilization capacity of -CDs was the largest among natural COs. The initial apparent association constant for MTBE-CD complex follows the order : gamma = beta > methyl-beta > hydroxypropyl beta > alpha. These differences of the constants are related to the size of MTBE and CDs. The size of beta-CD and gamma-CD is large to encapsulate MTBE molecule into the cavity, which that of alpha-CB is too small to encapsulate MTBE.

• 대한기계학회논문집A
• /
• 제25권9호
• /
• pp.1444-1451
• /
• 2001

The evolutionary structural optimization(ESO) method has been under continuous development since 1992. The bidirectional evolutionary structural optimization(BESO) method is made of additive and removal procedure. The BESO method is very useful to search the global optimum and to reduce the computational time. This paper presents the ranked bidirectional evolutionary structural optimization(R-BESO) method which adds elements based on a rank, and the performance indicator which can estimate a fully stressed model. The R-BESO method can obtain the optimum design using less iteration number than iteration number of the BESO.

• 한국세라믹학회지
• /
• 제35권1호
• /
• pp.33-40
• /
• 1998

A MgO-CaO-based coating material for ferrous melt refining is applied to the tundish operation for mol-ten steel having low carbon. The changes in the total oxygen content insoluble aluminum content and the content of inclusions in molten steel during tundish operation were measured at the pouring part strand of tundish and mold. On the basis of the experimental results the interfacial reaction occurring between the coating materials and the molten steel in tundish was discussed and compared with the theoretical con-sideration. It is concluded that interfacial reaction is not active at the strand part of tundish but is active at the pouring part because of the turbulent flow in the molten steel.

• Archives of Plastic Surgery
• /
• 제41권6호
• /
• pp.768-772
• /
• 2014

Background To compare clinical and radiographic outcomes between intramedullary nail fixation and percutaneous K-wire fixation for fractures in the distal third portion of the metacarpal bone. Methods A single-institutional retrospective review identified 41 consecutive cases of metacarpal fractures between September 2009 and August 2013. Each of the cases met the inclusion criteria for closed, extra-articular fractures of the distal third of the metacarpal bone. The patients were divided by the method of fixation (intramedullary nailing or K-wire). Outcomes were compared for mean and median total active motion of the digit, radiographic parameters, and period until return to work. Complications and symptoms were determined by a questionnaire. Results During the period under review, 41 patients met the inclusion criteria, and the fractures were managed with either intramedullary nailing (n=19) or percutaneous K-wire fixation (n=22). The mean and median total active range of motion and radiographic healing showed no statistically significant difference between the two groups. No union failures were observed in either group. The mean operation time was shorter by an average of 14 minutes for the percutaneous K-wire fixation group. However, the intramedullary nailing group returned to work earlier by an average of 2.3 weeks. Complications were reported only in the K-wire fixation group. Conclusions Intramedullary nailing fixation is advisable for fractures in the distal third of the metacarpal bone. It provides early recovery of the range of motion, an earlier return to work, and lower complication rates, despite potentially requiring a wire removal procedure at the patient's request.

• 공업화학
• /
• 제8권3호
• /
• pp.389-394
• /
• 1997

경각형 결정화에 의하여 벤젠-사이클로헥산 혼합물로부터 벤젠의 결정화에서 결정에 내포된 불순물(사이클로헥산)의 분포가 조사되었다. 결정의 순도에 미치는 결정성장속도의 영향을 파악하였으며 모든 실험결과는 Wintermantel 모델에 의해 도시될 수 있었다. 결정의 순도는 과냉각 정도가 클수록, 주입조성이 낮을 수록, 결정성장속도가 클 수록 낮았으며 결정성장속도는 불순물의 내포를 지배하는 가장 중요한 변수이다. 결정화 초기에 형성된 결정은 불순물을 많이 내포하고 있으며 결정의 두께가 증가함에 따라 불순물은 잔여용융액쪽으로 이동되어 배제됨을 알 수 있었다. 경막결정화에서 결정에 내포된 불순물은 일정두께의 결정층에 온도구배를 이용하여 결정을 부분용해시키면 불순물의 확산에 의하여 제거될 수 있음을 알 수 있었다.

• Membrane and Water Treatment
• /
• 제7권6호
• /
• pp.521-537
• /
• 2016

Laboratory-scale experiments were carried out to investigate the adsorption equilibrium, the adsorption kinetics and facilitated transport of two cationic dyes (Methylene Blue (MB) and Rhodamine B (RB)) on Polymer Inclusion Membrane (D2EHPA-PIM). Different adsorption isotherms (Freundlich, Langmuir and Temkin models) as well as kinetics models indicated that the adsorption process is spontaneous and exothermic. Under the optimal conditions, the adsorption removal efficiencies reach about 93% and 97% for MB and RB respectively. Different extraction values by D2EHPA-PIM were obtained for the two cationic dyes: MB is weakly extracted at pH 2.0 (E% = 18.7%) whilst E% = 82.4% was observed for RB at the same pH. This difference was exploited in a mixture containg both the 2 cationic dyes for the selective extraction of RB at pH 2. Desorption of both dyes was achieved from the membrane by using acidic aqueous solutions and desorption ratio up to 90% was obtained. The formulas of the extracted complexes by the PIMs were, determined by the method of slopes. The dyes transport was elucidated using mass transfer analysis where in it found relatively high values of the initial flux ($J_0$) as 41.57 and $18.74{\mu}mol.m^2.s^{-1}$ for MB and RB respectively.

• Journal of Chest Surgery
• /
• 제52권5호
• /
• pp.353-359
• /
• 2019

Background: To explore the effect of radiation on metastatic lymph nodes (LNs) after neoadjuvant chemoradiation therapy (nCRT), we examined the metastatic features of LNs according to their inclusion in the radiation field. Methods: The patient group included 88 men and 2 women, with a mean age of $61.1{\pm}8.1$ years, who underwent esophagectomy and lymphadenectomy after nCRT. Dissected LNs were compared in terms of clinical suspicion of metastasis, nodal station, and inclusion in the radiation field. Results: LN positivity did not differ between LNs that were inside (in-field [IF]) and outside (out-field [OF]) of the radiation field (IF: 40 of 465 [9%], OF: 40 of 420 [10%]; p=0.313). In clinical N+ nodal stations, IF stations had a lower incidence of metastasis than OF stations (IF/cN+: 16 of 142 [11%], OF/cN+: 9/30 [30%]; p=0.010). However, in clinical N- nodal stations, pathological positivity was not affected by whether the nodal stations were included in the radiation field (IF/cN-: 24 of 323 [7%], OF/cN-: 31 of 390 [8%]; p=0.447). Conclusion: Radiation therapy for nCRT could downstage clinically suspected nodal metastasis. However, such therapy was ineffective when used to treat nodes that were not suspicious for metastasis. Because significant numbers of residual metastases were identified irrespective of coverage by the radiation field, lymphadenectomy should be performed to ensure complete removal of residual nodal metastases after nCRT.