• BMB Reports
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• 제32권6호
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• pp.541-546
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• 1999

When we compared the chitinase activity of various plant sources using colorimetric or active gel-staining assay methods, the specific activity of pumpkin leaves was the highest among the samples we analyzed. The highly active chitinase from pumpkin leaves (designated PL-ChtIII) was purified to homogeneity using affinity chitin gel and HPLC Mono-Q anion-exchange cloumn chromatographies. In contrast to other members of the class III chitinase family, PL-ChtIII showed a strong binding affinity to the regenerated chitin gel column. The apparent molecular weight of PL-ChtIII was estimated to be 29 kDa on SDS-PAGE gel, while its optimum pH and temperature were shown to be pH 6.0 and $60^{\circ}C$, respectively. Analyzing the reaction products of PL-ChtIII with swollen chitin as substrate, the dimer and tetramer of N-acetylglucosamine were produced as major products in the first hour of the enzymatic reaction along with a small amount of monomers and trimers. As the reaction time increased, dimeric N-acetylglucosamine became the predominant form of reaction product.

• 한국환경과학회지
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• 제17권11호
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• pp.1221-1226
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• 2008

A variety of fungal species are known to degrade cyanide through the action of cyanide hydratase, a specialized nitrilases which hydrolyze cyanide to formamide. This work is a report on two unknown and un-characterized members from Neurospora crassa and Aspergillus nidulans. Recombinant forms of three cyanide hydratases (CHT) originated from N. crassa, Gibberella zeae, and A. nidulans were prepared after their genes were cloned with N-terminal hexahistidine purification tags, expressed in E. coli and purified using immobilized metal affinity chromatography. These enzymes were compared according to their pH activity profiles, and kinetic parameters. Although all three were similar, the N. crassa CHT has the widest pH range of activity above 50% and highest turnover rate ($6.6{\times}10^8min^{-1}$) among them. The CHT of A. nidulans has the highest Km value of the three nitrilases evaluated in here. Expression of CHT in both N. crassa and A. nidulans were induced by the presence of KCN, regardless of any presence of nitrogen sources. These data can be used to determine optimal procedures for the enzyme uses in the remediation of cyanide-containing wastes.

• Korean Chemical Engineering Research
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• 제59권2호
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• pp.153-158
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• 2021

In this study, we will determined the total phenolic content (TPC) and the antioxidant activity of the methanolic extract (ME) of date palm (Phoenix dactylifera. L) fruits (DPF) of four native cultivars from Algeria: Ghars (Gh), Chtaya (Cht), DeglaBeïda (DB) and Tinissine (Tns). The TPC of ME of DPF was measured by using Folin-Ciocalteu. Thereafter, the antioxidant capacity of various extracts was determined using DPPH test, reducing power and superoxide anion test. These results showed that dates had strongly scavenging activity on DPPH. The value of IC50 for DPPH radical test was 0.077 mg/ml in Cht. Also, Cht cultivar showed the best-reducing power, which was significantly higher than the other varieties. The less IC50 value in cyclic voltammetry method (CV), which meets the highest effective antioxidant, was 0.006 mg/ml in methanolic extract of Cht.

• 대한한방부인과학회지
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• 제35권3호
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• pp.1-23
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• 2022

Objectives: The purpose of this study is to evaluate anti-breast cancer and anti-inflammatory effects of Chungganhaewool-tang and Shipyeukmiyeugi-eum. Methods: MDA-MB-231 cells were used to measure cytotoxicity, Reactive oxygen species (ROS) production, protein expression amounts of Bcl-2-associated X protein (Bax), B-cell lymphoma 2 (Bcl-2), B-cell lymphoma-extra large (Bcl-xl), Cytochrome C Caspase-3, Caspase-7, Caspase-9, Poly ADP-ribose polymerase (PARP), Nuclear factor erythroid-2-related factor 2 (Nrf2), Heme oxygenase-1 (HO-1) and NAD (P) H Quinone Oxidoreductase 1 (NQO1) to evaluate the anti-breast cancer effects of Chungganhaewool-tang (CHT) and Shipyeukmiyeugi-eum (SYE), and THP-1 cells, differentiated into macrophage and induced inflammation with Lipopolysaccharide (LPS), were used to measure production amounts of ROS, Nitric oxide (NO), and protein expression amounts of Inducible nitric oxide synthase (iNOS), Cyclooxygenase (COX-2), Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6) and Tumor necrosis factor-alpha (TNF-α) to evaluate the anti-inflammatory effects of CHT and SYE. Results: CHT and SYE reduced MDA-MB-231 cell counts, increased protein expression of Bax and Cytochrome C, and decreased protein expression of Bcl-2, Bcl-xl. The protein expression amounts of Caspase-3, 7, and 9 decreased, but amounts of the active form, cleaved Caspase-3, 7, and 9, increased. In addition, PARP protein expression decreased, the amount of PARP protein in the cleaved form increased, and the amount of protein expressions of Nrf2 and HO-1 decreased, but NQO1 showed no significant difference. In THP-1 cells CHT and SYE reduced ROS and NO, and reduced protein expressions of iNOS, COX-2, IL-1, and TNF-α, but only SYE groups reduced IL-6. Conclusions: This study suggests that CHT and SYE have potential to be used as treatments for breast cancer.

• 설비공학논문집
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• 제18권5호
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• pp.451-457
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• 2006

Conjugate heat transfer (CHT) is the simultaneous, coupled heat transfer within a fluid and an adjoining solid, and the interface treatment plays an important role in its analysis, particularly when using unstructured grid system. In the present paper a new solid-fluid interface treatment in CHT analysis is presented and applied to two typical CHT problems, i.e. natural convections in both concentric thick-walled cylinders and cavity with a centered solid body. The present interface treatment for unstructured mesh clearly demonstrates the same accuracy and robustness as that for typical structured mesh.

• 한국정보통신학회논문지
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• 제5권7호
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• pp.1340-1345
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• 2001

본 논문은 이동물체의 이동 정보를 표현하는 OF의 최적해를 계산하고 동작 속도를 향상시키는 방법을 제안한다. 이를 위하여 CHT와 투표누적을 사용하여 기존의 방법에 비해 양호한 최적해를 계산하였고, 간단하게 이 동물체를 검색하였다.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.117-126
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• 2010

A chitinase (CHT) and a protease (PRO) were purified from the culture supernatant of Serratia sp. TKU017, with shrimp shell as the sole carbon/nitrogen source. The molecular masses of CHT and PRO determined by SDS-PAGE were approximately 65 kDa and 53 kDa, respectively. CHT was inhibited by $Mn^{2+}$ and $Cu^{2+}$, and PRO was inhibited by most tested divalent metals and EDTA. The optimum pH, optimum temperature, pH stability, and thermal stability of CHT and PRO were pH 5, $50^{\circ}C$, pH 5-7, and <$50^{\circ}C$, and pH 9, $40^{\circ}C$, pH 5-11, and <$40^{\circ}C$, respectively. PRO retained 95% of its protease activity in the presence of 0.5 mM SDS. The result demonstrates that PRO is an SDS-resistant protease and probably has a rigid structure. The $4^{th}$-day supernatant showed the strongest antioxidant activity (70%, DPPH scavenging ability) and the highest total phenolic content ($196{\pm}6.2\;{\mu}g$ of gallic acid equiv./ml). Significant associations between the antioxidant potency and the total phenolic content, as well as between the antioxidant potency and free amino groups, were found for the supernatant. With this method, we have shown that shrimp shell wastes can be utilized and it is effective in the production of enzymes and antioxidants, facilitating its potential use in industrial applications and functional foods.

• Asian Pacific Journal of Cancer Prevention
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• 제17권2호
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• pp.749-754
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• 2016

Extended follow-up of Hodgkin lymphoma (HL) survivors indicates that these patients are at high risk of secondary malignant neoplasms (SMNs) contributing to increased morbidity and mortality. This study examined the characteristics of HL survivors who developed SMNs with the aim to report any correlation with radiotherapy (RT) dose. In this retrospective multi-center cohort study of HL patients treated between 1990 and 2011 at three major teaching hospitals in Lebanon, classification was into two groups including those treated with combined modality (RT and chemotherapy-CHT) and those treated with CHT alone. Approval from the University Institutional Review Board (IRB) was obtained. Of the 112 patients evaluated, 52.7% (59) received the combined modality while 47.3% (53) received CHT alone. There were 6 cases of SMNs in the combined modality cohort and 5 cases in the CHT cohort. The mean RT dose in the combined modality cohort was 34.5 Gray (Gy) ($SD{\pm}5.3$). A statistically significant increase (1.5 fold) in the risk of developing SMNs was observed among patients who received a dose higher than 41 Gy compared to a dose between 20 to 30 Gy (OR= 1.5; 95% confidence interval= 0.674 to 3.339, p=0.012). The risk of SMNs was not significantly higher among patients who received extended field compared to involved field RT (p=0.964). This study showed that the risk of developing SMNs is higher among patients treated with RT dose greater than 31 Gy, independent of the RT type used.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2017년도 하계학술대회
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• pp.74-75
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• 2017

원의 대칭을 이용하는 회전 스캔 방식으로 원의 중심을 인식하는 기술을 제안한다. 컴퓨터 비전에서 원을 인식하는 기술은 매우 중요한 기술이다. 원 인식 기술은 높은 정확성을 위해 계속해서 연구되어왔다. 기존의 대표 기술인 Circle Hough transform(CHT)은 원을 인식하기 위해서 3차원의 축적 배열이 필요하며 실영상에서 원근 왜곡이 있는 경우에는 원이 인식되지 않는다. 원근 왜곡이 있는 경우에도 원 중심을 인식 할 수 있는 회전 스캔 방식을 제안한다. 제안하는 기술의 정확성을 입증하기 위해서 기존 기술 중 하나인 Open CV가 제공하는 gradient-CHT기술과 비교하는 실험을 진행하였다. 실험 결과는 제안하는 기술이 Open CV보다 우수하다는 것을 보여준다.

• 한국멀티미디어학회논문지
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• 제17권4호
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• pp.413-419
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• 2014

In this paper, we develop an automatic coin calculation system by using digital image processing. Existing schemes have the problem that is not able to exclude non-circular shape from the calculation. We propose a method to detect only coins which have circular form by applying the circular Hough transform(CHT). However, the CHT has the drawback that detects multiple circles even for just one coin because of shadow noise, the patterns on coins, and non-circular edge detection. We propose a post processing algorithm to overcome these limitations. The proposed system was implemented and successfully calculated the coin amount in the case that non-circular objects are mixed with coins.