광조사 강도가 복합레진의 중합반응속도에 미치는 영향에 관한 실시간 체적측정법을 이용한 연구

라성호,이인복,김창근,조병훈,이광원,손호현 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.2

Objectives The aim of this study is to evaluate the effect of light intensity variation on the polymerization rate of composite resin using IB system (the experimental equipment designed by DR. IB Lee) by which real-time volumetric change of composite can be measured. Methods Three commercial composite resins [Z100(Z!), AeliteFil(AF), SureFil(SF)] were photopolymerized with Variable Intensity Polymerizer unit (Bisco, U.S.A.) under the variable light intensity (75/150/225/300/375/450mW^2) during 20 sec. Polymerization shrinkage of samples was detected continuously by IB system during 110 sec and the rate of polymerization shrinkage was obtained by its shrinkage data. Peak time(P.T.) showing the maximum rate of polymerization shrinkage was used to compare the polymerization rate. Results Peak time decreased with increasing light intensity(p<0.05). Maximum rate of polymerization shrinkage increased with increasing light intensity(p<0.05). Statistical analysis revealed a significant positive correlation between peak time and inverse square root of the light intensity (AF:R=0.965, Z1:R=0.974, SF:R=0.927). Statistical analysis revealed a significant negative correlation between the maximum rate of polymerization shrinkage and peak time(AF:R=-0.933, Z1:R=-0.892, SF:R=-0.883), and a significant positive correlation between the maximum rate of polymerization shrinkage and square root of the light intensity(AF:R=0.988, Z1:R=0.974, SF:R=0.946). Discussion and Conclusions The polymerization rate of composite resins used in this study was proportional to the square root of light intensity. Maximum rate of polymerization shrinkage as well as peak time can be used to compare the polymerization rate. Real-time volume method using IB system can be a simple, alternative method to obtain the polymerization rate of composite resins.

Bortezomib과 Dexamthasone으로 치료한 골수외 형질세포종 4예

백종현,이은영,장리라,손창배,신은경,서정아,이지숙,이호섭,이상민,신성훈,김양수 고신대학교의과대학 2007 고신대학교 의과대학 학술지 Vol.22 No.2

Despite the use of aggressive local and systemic treatment including autologous stem cell transplantation in multiple myeloma, extramedullary recurrences are common and the prognosis of these patients is poor. Many novel drugs such as thalidomide, lenalidomide and bortezomib improve the response of treatment of multiple myeloma, but some reports failed to describe thalidomide has effect in extramedullary plasmacytoma. Recent data report on the successful treatment plasmacytomas with bortezomib in patients with advanced multiple myeloma. We treated 4 relapsed or refractory extramedullary plasmacytomas with bortezomib at our institution. We recognized all these extramedullary plasmacytomas decreased and showed more than partial response. This report lends support to the efficacy of bortezomib in the treatment of plasmacytoma and describes the safe use of bortezomib. Responses may, however, be of short duration. Therefore, despite our limited experience, we propose that bortezomib may be considered a therapeutic option for such patients who have risk of radiation therapy

리튬브로마이드(LiBr) 용액과 열교환기를 이용한 온실하우스의 온 습도 제어 시스템 성능 분석

조라훈 ( La Hoon Cho ),박선용 ( Sun Yong Park ),이서현 ( Seo Hyeon Lee ),오광철 ( Kwang Cheol Oh ),이상열 ( Sang Yeol Lee ),주상연 ( Sang Yeon Joo ),이충건 ( Chung Geon Lee ),김대현 ( Dae Hyun Kim ) 한국농업기계학회 2016 한국농업기계학회 학술발표논문집 Vol.21 No.2

국내의 여름철 고온다습한 기후는 온실내부에서 작물의 생장에 악영향을 미치므로 내부공기의 냉각 및 제습이 필수적이다. 따라서 본 연구에서는 리튬브로마이드(LiBr) 수용액과 냉각 휜(fin)을 이용한 온실의 온습도 제어실험과 이를 적용한 수치해석분석이 수행되었다. 실험을 위해 Fan and Pad 방식이 적용된 중간시험규모(Pilot Scale)의 온실을 제작하여, 외부공기가 풍도(Duct)관을 통해 유입될 수 있도록 하였고, 리튬브로마이드 수용액이 공급 가능한 패드와 열교환기를 설치하여 냉각 및 제습 시스템을 구축했다. 실험결과 고온다습의 외부공기가 제습시스템을 통하여 상대습도가 93%에서 82%로 감소하였고, 냉각시스템을 통해 온실 내부 온도가 307K에서 302K로 감소되었다. 또한 실험결과의 성능분석을 위하여 메틀렙(R2016a, The Mathworks INC, USA)을 통한 열역학적 시뮬레이션이 진행되었다. 실험결과와 시뮬레이션 결과를 비교했을 때, 결정계수(R-squared)와 제곱근평균오차1(Root Mean Square Error, RMSE1,)값이 각각 0.92, 0.84로 나타났다.

리튬브로마이드 수용액의 흡습성질을 이용한 온실 냉방 및 제습 시스템 개발

조라훈 ( La Hoon Cho ),오광철 ( Kwang Cheol Oh ),이상열 ( Sang Yeol Lee ),주상연 ( Sang Yeon Joo ),박선용 ( Sun Yong Park ),이서현 ( Seo Hyeon Lee ),정인선 ( In Seon Jeong ),이충건 ( Chung Geon Lee ),김대현 ( Dae Hyun Kim ) 한국농업기계학회 2017 한국농업기계학회 학술발표논문집 Vol.22 No.1

국내 여름철의 고온다습한 기후환경으로 인하여 온실 내부의 냉방 및 제습이 필수적인데, 온실 냉방방식 중 증발냉각 시스템이 가장 효율이 높다고 알려져 있다. 하지만 증발냉각 시스템은 건조한 기후 지역에서 발달한 방식으로, 작물의 증산작용으로 인한 온실 내부 습도 상승에 따른 문제점이 발생되어 다습한 여름철 국내 기후에는 반드시 냉각과 제습이 동시에 필요하다. 따라서 증발냉각 방식 중 Fan and Pad 방식과 리튬브로마이드 수용액을 이용한 온실 냉방 및 제습을 위한 복합시스템에 관한 연구가 진행중이다. 현재 리튬브로마이드 수용액 제습 시 발생되는 발열량과 수용액의 무게변화와 같은 수용액의 흡습성질 대한 정확한 지표가 나타나 있지 않다. 이에 연구를 진행하기에 앞서 리튬브로마이드 흡습성질에 관한 데이터 자료가 필요하다고 판단되어 기초실험을 진행하였고, 본 연구에서는 Pilot Scale의 재생 순환시스템을 통해 리튬브로마이드 수용액의 흡습성질을 이용한 재사용 방안을 제시하였고, 시스템 내에서 외부투입공기와 작동유체의 흡습성질에 의한 반응 전후 온도변화 예측 모델을 수립하였다. 따라서 본 연구를 통해 리튬브로마이드 수용액의 흡습성질을 분석하고, 이를 이용한 재생 순환 시스템에 관한 연구를 진행할 예정이다.

고융점희유금속의저온소결방법

( Sang Hyeok Im ),( Dong Hwan Kim ),( Young Hoon La ),( Nam Jin Kim ),( Cha Won Hwang ),( Jae Min Cha ),( Bong Ki Ryu ) 대한금속재료학회 ( 구 대한금속학회 ) 2010 재료마당 Vol.23 No.3

This study looks at crystallization and sintering behavior in B2O3 containing Li2O-Al2O3-SiO2 glass powder. The sintered sample was produced with glass powders measuring 44 μm. The relative density and transmittance of the sintered samples showed the highest value at the temperature of 650°C. At temperatures higher than 650°C, crystal growth occurred to decrease the densification of B2O3-Li2O-Al2O3-SiO2 (BLAS) glass powder. The main crystalline phase in the glass powder was a-spodumene. From non-isothermal differential thermal analysis, the crystallization of particles (Φ=44 μm) was observed at 640°C to 684°C with respect to the heating rate. The activation energy of crystallization (E(C)) and the Avrami constant (n) calculated by Kissinger and Ozawa equations indicated that the surface and the bulk crystallization occurred simultaneously in the glass. The optimum sintering temperature of this glass powder was 650°C without crystal growth of β-spodumene, although nucleation or nano-crystal growth occurred.

Clinical Implication of Candida Score in Multidrug-Resistant Pneumonia with Airway Candida Colonization

La Yeonju,Kwon Da Eun,Jeon Soyoung,Lee Sujee,Lee Kyoung Hwa,Han Sang Hoon,Song Young Goo 대한감염학회 2022 Infection and Chemotherapy Vol.54 No.2

Background The growth of Candida in respiratory secretions is usually considered colonization, and antifungal therapy is rarely required. The role of Candida colonization in the progression of bacterial pneumonia remains controversial. The aim of this study was to identify the clinical implication of Candida score by analyzinge the relationship with multidrug-resistant (MDR) pneumonia and prognosis in patients with airway Candida colonization. Materials and Methods This study was a retrospective review of patients with airway Candida colonization by bronchial washing or bronchoalveolar lavage. The Candida score was calculated according to the four factors (severe sepsis, surgery at baseline, total parenteral nutrition, and multifocal Candida colonization). Pneumonia related mortality or hopeless discharge expecting death was defined as a poor outcome. Results A total of 148 patients were enrolled in the study. In a multivariate analysis model, Candida score was identified as an independent predictor of poor outcomes (odds ratio 2.23; 95% confidential interval 1.57 – 3.17; P <0.001) in pneumonia patients with airway Candida colonization. With a Candida score of three or higher compared with low score group, it was associated with bacterial pneumonia, especially methicillin-resistant Staphylococcus aureus (MRSA) infection (0.0% vs. 15.2%, P = 0.004). In addition, patients with a high Candida score had a longer hospital stay (13 vs. 38 days, P <0.001), longer duration of intensive care (7 vs. 18 days, P <0.001), and higher pneumonia-related mortality (0.0% vs. 45.5%, P <0.001) as compared to the low Candida score group. The Candida score showed a positive correlation with other pneumonia severity scales such as CURB-65 (Confusion, Urea, Respiratory rate, Blood pressure, and age ≥65 years) (r = 0.461, P <0.001), Pneumonia Severity Index (r = 0.397, P <0.001), and predisposition, insult, response, and organ dysfunction (PIRO) score (r = 0.425, P <0.001). Conclusion This study revealed that Candida is no longer a bystander of airway colonization, and that it affects the progression of bacterial pneumonia, including multidrug-resistant pathogens, particularly MRSA infection. Also Candida score can be used to predict the prognosis of patients with pneumonia. Background The growth of Candida in respiratory secretions is usually considered colonization, and antifungal therapy is rarely required. The role of Candida colonization in the progression of bacterial pneumonia remains controversial. The aim of this study was to identify the clinical implication of Candida score by analyzinge the relationship with multidrug-resistant (MDR) pneumonia and prognosis in patients with airway Candida colonization. Materials and Methods This study was a retrospective review of patients with airway Candida colonization by bronchial washing or bronchoalveolar lavage. The Candida score was calculated according to the four factors (severe sepsis, surgery at baseline, total parenteral nutrition, and multifocal Candida colonization). Pneumonia related mortality or hopeless discharge expecting death was defined as a poor outcome. Results A total of 148 patients were enrolled in the study. In a multivariate analysis model, Candida score was identified as an independent predictor of poor outcomes (odds ratio 2.23; 95% confidential interval 1.57 – 3.17; P <0.001) in pneumonia patients with airway Candida colonization. With a Candida score of three or higher compared with low score group, it was associated with bacterial pneumonia, especially methicillin-resistant Staphylococcus aureus (MRSA) infection (0.0% vs. 15.2%, P = 0.004). In addition, patients with a high Candida score had a longer hospital stay (13 vs. 38 days, P <0.001), longer duration of intensive care (7 vs. 18 days, P <0.001), and higher pneumonia-related mortality (0.0% vs. 45.5%, P <0.001) as compared to the low Candida score group. The Candida score showed a positive correlation with other pneumonia severity scales such as CURB-65 (Confusion, Urea, Respiratory rate, Blood pressure, and age ≥65 years) (r = 0.461, P <0.001), Pneumonia Severity Index (r = 0.397, P <0.001), and predisposition, insult, response, and organ dysfunction (PIRO) score (r = 0.425, P <0.001). Conclusion This study revealed that Candida is no longer a bystander of airway colonization, and that it affects the progression of bacterial pneumonia, including multidrug-resistant pathogens, particularly MRSA infection. Also Candida score can be used to predict the prognosis of patients with pneumonia.

Colloidal inverse bicontinuous cubic membranes of block copolymers with tunable surface functional groups

La, Yunju,Park, Chiyoung,Shin, Tae Joo,Joo, Sang Hoon,Kang, Sebyung,Kim, Kyoung Taek Nature Publishing Group 2014 Nature chemistry Vol.6 No.6

Analogous to the complex membranes found in cellular organelles, such as the endoplasmic reticulum, the inverse cubic mesophases of lipids and their colloidal forms (cubosomes) possess internal networks of water channels arranged in crystalline order, which provide a unique nanospace for membrane-protein crystallization and guest encapsulation. Polymeric analogues of cubosomes formed by the direct self-assembly of block copolymers in solution could provide new polymeric mesoporous materials with a three-dimensionally organized internal maze of large water channels. Here we report the self-assembly of amphiphilic dendritic–linear block copolymers into polymer cubosomes in aqueous solution. The presence of precisely defined bulky dendritic blocks drives the block copolymers to form spontaneously highly curved bilayers in aqueous solution. This results in the formation of colloidal inverse bicontinuous cubic mesophases. The internal networks of water channels provide a high surface area with tunable surface functional groups that can serve as anchoring points for large guests such as proteins and enzymes.

Initial Preliminary Studies in National Long-Term Ecological Research(LTER) Stations of Daechung Reservoir

( Sang Jae Lee ),( Jae Hoon Lee ),( Jong Im Kim ),( Geung Hwan La ),( Min Ae Yoem ),( Woong Ghi Shin ),( Hyun Woo Kim ),( Min Ho Jang ),( Kwang Guk An ) 한국하천호수학회 2009 생태와 환경 Vol.42 No.4

Initial Preliminary Studies in National Long-Term Ecological Research (LTER) Stations of Daechung Reservoir

Lee, Sang-Jae,Lee, Jae-Hoon,Kim, Jong-Im,La, Geung-Hwan,Yoem, Min-Ae,Shin, Woong-Ghi,Kim, Hyun-Woo,Jang, Min-Ho,An, Kwang-Guk The Korean Society of Limnology 2009 생태와 환경 Vol.38 No.1

Major objective of our study was to introduce initial researches of national long-term ecological monitoring studies on Daechung Reservoir, as one of the representative lentic reservoir ecosystems in Korea. For the long-term ecological research (LTER), we conducted preliminary field monitoring during 2008~2009 and analyzed biological parameters such as phytoplankton, zooplankton, and freshwater fish along with chemical water quality and empirical model analysis. According to phytoplankton surveys, major taxa have varied largely depending on seasons and sites sampled. Overall phytoplankton data showed that cyanophyta dominated in the summer period and diatoms dominated in the winter. In zooplankton analysis, 25 species including 20 rotifers, 3 cladocerans and 2 copepods were collected during the survey. The relative abundance of rotifers (86.5%) was always greater than that of cladocerans (6.3%) or copepods (5.1%). There were distinct spatial and inter-annual changes in the abundance of zooplankton in the reservoir, displaying similar patterns in three sites with the exception of S3 during the study. According to fish surveys, 8 families and 39 species were observed during 2008~2009. The most dominant fish was an exotic species of Lepomis macrochirus (23%), indicating an severe influence of exotic species to the ecosystem. TP averaged $17.9\;{\mu}g\;L^{-1}$ ($6{\sim}80\;{\mu}g\;L^{-1}$), which was judged as a mesotrophy, and showed a distinct longitudinal gradients. TN averaged $1.585\;{\mu}g\;L^{-1}$ during the study and judged as hypereutrophic condition. Unlike TP, TN didn't show any large seasonal and spatial variations. Under the circumstances, nitrogen limitation may not happen in this system, indicating that nitrogen control is not effective in the watershed managements. These data generated in the LTER station will provide key information on long-term biological and water quality changes in relation to global warming and some clues for efficient reservoir ecosystem managements.

첨가제 펠릿을 이용한 목재 펠릿보일러의 타르 감소와 열효율 분석

주상연(Sang Yeon Joo),이충건(Chung Geon Lee),정인선(In Seon Jeong),박선용(Sun Yong Park),오광철(Kwag Cheol Oh),조라훈(La Hoon Cho),이상열(Sang Yeol Lee),김민준(Min Jun Kim),김석준(Seok Jun Kim),김대현(Dae Hyun Kim) 한국신재생에너지학회 2019 신재생에너지 Vol.15 No.2

Wood pellets are ‘carbon natural’ fuels that contribute to greenhouse gas reduction regulation. On the other hand, the tar, generated from woody biomass combustion, condenses and accumulates in the combustion chamber resulting in a reduction of heat transfer on the surface where heat exchange takes place, which decreases the thermal efficiency and equipment life span. To solve these problems, an additive acting as a catalyst for a reforming reaction was mixed with the pellets to reduce tar formation in combustion. For the experiment, 2% of dolomite, 2% of limestone and 1% mixture of dolomite and limestone were added as catalysts to the wood pellets. The experiments were conducted in the same external environment and a comparison of the thermal efficiency and reduction of tar of boiler containing the solid additive was carried out. As a result, the thermal efficiency of the additive pellets was increased by 1.09% and 0.36% for dolomite 2%, limestone 1% and dolomite 1%, respectively, compared to conventional wood pellets, and decreased by 0.46 for 2% lime stone. Although the thermal efficiency of the dolomite 2% additive pellets was the highest, pellets with 1% dolomite and 1% limestone produced the best result.