• 한국식생활문화학회지
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• 제12권5호
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• pp.463-468
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• 1997

Starch plays an important role in textural quality of infant food which is mainly affected by retrogradation of starch during storage. The acetylated rice was prepared and its physicochemical properties were evaluated to improve the textural quality of infant food when added. When the rice powder was reacted with acetic acid with its increasing concentration from 0.1 M, 0.2 M to 0.3 M, the amount of acetyl group and degree of substitution were increased by 0.39%, 0.8% and 1.27%, and by 0.0014, 0.031 and 0.048, respectively. The initial gelatinization temperature of rice paste determined by amylograph was decreased from $79.5^{\circ}C$ of unmodified rice to $67.5^{\circ}C$ of acetylated rice whose DS is 0.048. The apparent and maxium viscosity of rice paste at $95^{\circ}C$ before and after modification were increased from 92 B.U. to 201 B.U. and from 100 B.U. to 236 B.U., respectively, The degree of retrogradation and rate of syneresis were decreased from 28.7 to 18.8 and from 0.47% to 0.25%, respectively with increased by DS from 0 to 0.048. The digestibility rate of rice powder decreased from 9.19 of natural rice powder to 7.54 of acetylated rice powder whose DS is 0.048. In United State, there is no serious problem in total digestibility because only 4% of modified rice powder is added in production of infant food.

• 정보처리학회논문지C
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• 제15C권1호
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• pp.9-18
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• 2008

센서 노드의 프로그램 변경을 통한 센서 네트워크 공격을 방지하는 것은 중요한 센서 네트워크 관련 보안요소들 중 하나이다. 이를 해결하기 위해 각 센서 노드 내에서 실행 중인 코드가 변경되지 않았음을 검증하는 소프트웨어 기반 검증(attestation) 기술이 사용되고 있다. 그러나 현재 제안되고 있는 소프트웨어 기반 검증 기법은 신뢰할 수 있는 검증자가 존재하지 않는 센서 네트워크 환경에 대한 고려가 부족할 뿐만 아니라, 망의 변화가 없는 정적인 환경에 중점을 두어 설계되었기 때문에 센서 네트워크 환경에 적합하지 않다. 본 논문에서는 SWATT(Software-based ATTestation) 기법을 이용하여 센서 네트워크 환경에 적합한 상호 검증 프로토콜을 제안한다. 제안 기법은 신뢰 노드가 존재하지 않는 센서 네트워크 환경에서 이웃한 센서 노드에게 자신의 존재를 주기적으로 알리되, SWATT 기법을 이용하여 이를 인지한 이웃 센서 노드와 상호 검증을 수행하도록 한다. 이를 통해 신뢰할 수 있는 검증자가 없는 센서 네트워크 환경에서 악의적인 공격으로 인해 변경된 프로그램을 실행하는 센서 노드를 식별할 수 있으며, 결과적으로 검증된 센서 노드들만으로 이루어지는 네트워크 구성이 가능하도록 한다.

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.725-729
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• 2008

An enzyme reactor installed with ultrafiltration membrane was developed to produce ${\alpha}-,\;{\beta}-$, and ${\gamma}$-cyclodextrins (CDs) from soluble starch by Bacillus macerans cyclodextrin glycosyltransferase (CGTase) tagged with 10 lysines at its C-terminus (CGTKIOase). Ultrafiltration membrane YM10 with 10,000 of molecular cutoff was chosen for membrane modification and CD production. A repeated-batch type of the enzyme reaction with free CGTK10ase resulted in a ${\alpha}$-CD yield of 24.0 (${\pm}1.5$)% and a productivity of 4.68 (${\pm}0.88$) g/l-h, which were 7 times higher that those for CGTK10ase immobilized on modified YM10 membrane. Addition of 1-nonanol increased CD yields by 30% relative to the control, which might be due to prevention of the reversible hydrolysis of CDs.

• 한국식품과학회지
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• 제19권2호
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• pp.97-101
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• 1987

쌀보리인 영산보리 전분의 결정구조는 수분-열처리하지않은 것과 수분-열처리 한것 모두 A형을 나타냈고, 그 결정 정도는 수분-열처리 정도가 높아질수록 약해졌다. 물 결합능력은 수분-열처리 정도가 높아질수록 증가하였다. 팽윤력 및 용해도는 온도상승에 따라 증가하였으며 수분-열처리 정도가 높아질수록 같은 온도에서 팽윤력은 감소, 용해도는 점차 증가하는 경향을 나타냈다. 가열에 따른 호화도의 변화는 수분-열처리 하지않은 것과 수분-열처리 한것 모두 $45^{\circ}C$이후 호화도가 급격히 증가하였다. 알카리 호화에 의한 점도는 수분-열처리 정도가 증가할수록 겉보기 점도가 감소하였다. 아밀로그람 특성값은 수분-열처리 정도가 높을수록 호화온도는 약간 높은 값을 나타냈으며 점도는 약간씩 낮은 값을 나타냈다.

• Membrane and Water Treatment
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• 제6권3호
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• pp.173-187
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• 2015

The goal of present work is the preparation of a novel positively charged nanofiltration (NF) membrane and its development for the cation removal of aqueous solutions. This NF membrane was fabricated by the surface modification of polysulfone (PSf) ultrafiltration support. The active top-layer was formed by interfacial cross-linking polymerization of poly(ethyleneimine) (PEI) with p-xylylene dichloride (XDC) and then quaternized with methyl iodide to form a perpetually positively charged layer. In order to improve the efficiency of nanofiltration membrane, the concentration of PEI, XDC and methyl iodide solutions, PEI coating and cross-linking time have been optimized. As a result, a high water flux and high $CaCl_2$ rejection (1,000 ppm) was obtained for the composite membrane with values of $18.29L/m^2.h$ and 93.62% at 4 bar and $25^{\circ}C$, respectively. The rejections of NF membrane for different salt solutions followed the order of $Na_2SO_4$ < $MgSO_4$ < NaCl < $CaCl_2$. Molecular weight of cut off (MWCO) was calculated via retaining of PEG solutions with different molecular weights that finally, it revealed the Stokes and hydrodynamic radius of 1.457 and 2.507 nm on the membrane selective layer, respectively. The most efficient positively charged nanofiltration membrane exhibited a $Ni^{2+}$ rejection of 96.26% for industrial wastewater from Shamse Hadaf Co. (Kashan, Iran).

• Clinical and Experimental Reproductive Medicine
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• 제17권2호
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• pp.197-202
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• 1990

Early studies demonstrated that seminal plasma has a factor which inhibits fertilizing ability in a reversible manner. The factor can be precipitated by centrifugation at 104000g for 18 hr. The precipitate was applied to a CM cellulose column and eluted with high salt concentration. This fraction possessed antifertilizing activity was applied to a Sephacryl S-200 column according to a modification of the method of Reddy et al. Using such inhibition of in vitro fertilization ability as an assay, we have carried our experiments to purified the factor. When the factor was added to IVF medium, 70-80% of fertilization was inhibited.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2269-2273
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• 2012

Pseudo-first-order rate constants $k_{amine}$ have been measured spectrophotometrically for the reactions of benzyl 4-pyridyl carbonate 6 with a series of alicyclic secondary amines in $H_2O$ at $25.0^{\circ}C$. The plots of $k_{amine}$ vs. [amine] curve upward, indicating that the reactions proceed through a stepwise mechanism with two intermediates, a zwitterionic tetrahedral intermediate $T^{\pm}$ and its deprotonated form $T^-$. This contrasts to the report that the corresponding reactions of benzyl 2-pyridyl carbonate 5 proceed through a forced concerted pathway. The $k_{amine}$ values for the reactions of 6 have been dissected into the second-order rate constant $Kk_2$ and the thirdorder rate constant $Kk_3$. The Br${\o}$nsted-type plots are linear with ${\beta}_{nuc}=0.94$ and 1.18 for $Kk_2$ and $Kk_3$, respectively. The $Kk_2$ for the reaction of 6 is smaller than the second-order rate constant $k_N$ for the corresponding reaction of 5, although 4-pyridyloxide in 6 is less basic and a better nucleofuge than 2-pyridyloxide in 5.

• Macromolecular Research
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• 제11권1호
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• pp.14-18
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• 2003

Grafting of glycidyl methacrylate (GMA) upon coralline hydroxyapatite in conjugation with demineralized bone matrix (CHA-DBM) using equal molar ratio of potassium persulfate/sodium metabisulfite redox initiating system was investigated in aqueous medium. The optimum reaction condition was standardized by varying the concentrations of backbone, monomer, initiator, temperature and time. The results obtained imply that the percent grafting was found to increase initially and then decrease in most of the cases. The optimum temperature and time were found to be 50 $^{\circ}C$ and 180 min, respectively, to obtain higher grafting yield. Fourier transform infrared (FT-IR) spectroscopy and X-ray powder diffraction (XRD) method were employed for the proof of grafting. The FT-IR spectrum of grafted CHA-DBM showed epoxy groups at 905 and 853 $cm^{-1}$ / and ester carbonyl group at 1731 $cm^{-1}$ / of poly(glycidyl methacrylate) (PGMA) in addition to the characteristic absorptions of CHA-DBM, which provides evidence of the grafting. The XRD results clearly indicated that the crystallographic structure of the grafted CHA-DBM has not changed due to the grafting reaction. Further, no phase transformation was detected by the XRD analysis, which suggests that the PGMA is grafted only on the surface of CHA-DBM backbone. The grafted CHA-DBM will have better functionality because of their surface modification and hence they may be more useful in coupling of therapeutic agents through epoxy groups apart from being used as osteogenic material.

• Journal of Gastric Cancer
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• 제18권2호
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• pp.142-151
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• 2018

Purpose: The modification of the cancer classification system aimed to improve the classical anatomy-based tumor, node, metastasis (TNM) staging by considering tumor biology, which is associated with patient prognosis, because such information provides additional precision and flexibility. Materials and Methods: We previously developed an mRNA expression-based single patient classifier (SPC) algorithm that could predict the prognosis of patients with stage II/III gastric cancer. We also validated its utilization in clinical settings. The prognostic single patient classifier (pSPC) differentiates based on 3 prognostic groups (low-, intermediate-, and high-risk), and these groups were considered as independent prognostic factors along with TNM stages. We evaluated whether the modified TNM staging system based on the pSPC has a better prognostic performance than the TNM 8th edition staging system. The data of 652 patients who underwent gastrectomy with curative intent for gastric cancer between 2000 and 2004 were evaluated. Furthermore, 2 other cohorts (n=307 and 625) from a previous study were assessed. Thus, 1,584 patients were included in the analysis. To modify the TNM staging system, one-grade down-staging was applied to low-risk patients according to the pSPC in the TNM 8th edition staging system; for intermediate- and high-risk groups, the modified TNM and TNM 8th edition staging systems were identical. Results: Among the 1,584 patients, 187 (11.8%), 664 (41.9%), and 733 (46.3%) were classified into the low-, intermediate-, and high-risk groups, respectively, according to the pSPC. pSPC prognoses and survival curves of the overall population were well stratified, and the TNM stage-adjusted hazard ratios of the intermediate- and high-risk groups were 1.96 (95% confidence interval [CI], 1.41-2.72; P<0.001) and 2.54 (95% CI, 1.84-3.50; P<0.001), respectively. Using Harrell's C-index, the prognostic performance of the modified TNM system was evaluated, and the results showed that its prognostic performance was better than that of the TNM 8th edition staging system in terms of overall survival (0.635 vs. 0.620, P<0.001). Conclusions: The pSPC-modified TNM staging is an alternative staging system for stage II/III gastric cancer.

• 한국의학물리학회지:의학물리
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• 제13권1호
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• pp.9-14
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• 2002

두부 프레임을 지지하는 방식으로 pedestal mounting system과 couch mounting system의 장점을 수용한, 새로운 형태의 분할 정위방사선 치료 시스템을 개발하였다. 두부 고정을 위한 프레임은 두랄루민으로 제작하였고, 카우치에 부착되게 하였다. 프레임 내에서 환자의 두부를 고정하기 위해 치아 고정장치와 3.2 mm 열프라스틱으로 전두부와 후두부에 마스크를 제작할 수 있다. 정위 좌표 구현을 위한 전산화 단층촬영 localizer는 각 병원에서 많이 사용하고 있는 Brown-Roberts-Walls(B.R.W) 시스템을 사용할 수 있게 하여, 개발된 시스템의 신뢰성을 높이고 제작 단가도 낮추고자 하였다. 프레임 mounting system은 pedestal mounting system을 수정, 보완한 형태로 개발하였다. 시스템은 카우치를 지지하는 바닥 면에 고정되어 카우치에 부착된 프레임과 결합할 수 있고, 시스템과 카우치의 잠금 장치를 푼 채 자유롭게 x, y축으로 유동할 수 있다. 프레임 mounting system의 중심축은 상, 하 방향으로 이동 가능한 포인터 형태로 제작하여, 치료기의 구동 정확성을 검증하는 정도 관리에 응용 가능하다. 개발된 시스템의 재현성과 정확도 검증을 위해 아크릴 팬텀과 포인터를 제작하였고, 전산화 단층촬영 영상에서 획득한 팬텀 내 목표점의 정위 좌표를 dial-gauge와 E.C.L 필름으로 검증하였다. 실험의 결과 x축 방향의 재현성 오차는 0.71$\pm$0.19 mm, y축 방향은 0.45$\pm$0.15 mm, z축 방향 재현성 오차는 0.63$\pm$0.18 mm로 나타났고, 최대 1.3 mm 이내의 우수한 재현성을 보였다. 연구 결과로 개발된 분할 정위방사선 치료 시스템은 재현성이 우수하고, 전체 중량이 가벼워 사용하기 쉽게 제작되었다. 특히 수정된 pedestal frame mounting system으로 설계되어 후두부 방사선 조사가 가능한 장점이 있다.