• 대한의용생체공학회:의공학회지
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• 제17권4호
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• pp.507-514
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• 1996

The automated ECG diagnostic systems in hospital have a low P-wave detection capacity in case of some diseases like conduction block. The purpose of this study is to improve the P-wave detection ca- pacity using wavelet transform. The first procedure is to remove baseline drift by subtracting the median filtered signal from the original signal. The second procedure is to cancel ECG's QRS-T complex from median filtered signal to get P-wave candidate. Before we subtracted the templete from QRS-T complex, we estimated the best matching between templete and QRS-T complex to minimize the error. Then, wavelet transform was applied to confirm P-wave. In particular, haiti wavelet was used to magnify P-wave that consisted of low frequency components and to reject high frequency noise of QRS-T complex cancelled signal. Finally, p-wave was discriminated and confirmed by threshold value. By using this method, We can got the around 95.1% P-wave detection. It was compared with contextual information.

• Rapid Communication in Photoscience
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• 제3권4호
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• pp.81-84
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• 2014

To examine the microenvironmental effect of DNA on the photosensitized reaction, the electron-donor-connecting porphyrin, meso-(9-phenanthryl)-tris(N-methyl-p-pyridinio) porphyrin (Phen-TMPyP), was synthesized. Phen-TMPyP can bind to oligonucleotides with two binding modes, depending on the DNA concentration. The fluorescence lifetime measurement of Phen-TMPyP shows a shorter component than that of the reference porphyrin without the phenanthryl moiety. However, the observed value is much longer than those of previously reported similar types of electron-donor-connecting porphyrins, suggesting that electron-transfer quenching by the phenanthryl moiety is not sufficient. The fluorescence quantum yield of Phen-TMPyP ($5{\mu}M$) decreased with an increase in DNA concentration of up to $5{\mu}M$ base pair (bp), possibly due to self-quenching through an aggregation along the DNA strand, increased with an increase in DNA concentration of more than $5{\mu}M$ bp and reached a plateau. The fluorescence quantum yield of Phen-TMPyP with a sufficient concentration of DNA was larger than that of the reference porphyrin. The singlet oxygen ($^1O_2$) generating activity of Phen-TMPyP was confirmed by the near-infrared emission spectrum measurement. The quantum yield of $^1O_2$ generation was decreased by a relatively small concentration of DNA, possibly due to the aggregation of Phen-TMPyP, and recovered with a sufficient concentration of DNA. The recovered quantum yield was rather smaller than that without DNA, indicating the quenching of $^1O_2$ by DNA. These results show that a DNA strand can stabilize the photoexcited state of a photosensitizer and, in a certain case, suppresses the $^1O_2$ generation.

• Asian Pacific Journal of Cancer Prevention
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• 제16권2호
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• pp.513-517
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• 2015

Background: Growing evidence suggests that the members of the ubiquitin-proteasome system (UPS) are important for tumorigenesis. HERC4, one component, is a recently identified ubiqutin ligase. However, the expression level and function role of HERC4 in lung cancer remain unknown. Our objective was to investigate any correlation between HERC4 and development of lung cancer and its clinical significance. Materials and Methods: To determine HERC4 expression in lung cancer, an immunohistochemistry analysis of a tissue microarray containing samples of 10 lung normal tissues, 15 pulmonary neuroendocrine carcinomas, 45 squamous epithelial cancers and 50 adenocarcinomas was conducted. Receiver operating characteristic (ROC) curve analysis was applied to obtain a cut-off point of 52.5%, above which the expression of HERC4 was regarded as "positive". Results: On the basis of ROC curve analysis, positive expression of HERC4 was detected in 0/10 (0.0%) of lung normal tissues, in 4/15 (26.7%) of pulmonary neuroendocrine carcinomas, in 13/45 (28.9%) of squamous epithelial cancers and in 19/50 (38.0%) of adenocarcinomas. It showed that lung tumors expressed more HERC4 protein than adjacent normal tissues (${\chi}^2$=4.675, p=0.031). Furthermore, HERC4 positive expression had positive correlation with pT status (${\chi}^2$=44.894, p=0.000), pN status (${\chi}^2$=43.628, p=0.000), histological grade (${\chi}^2$=7.083, p=0.029) and clinical stage (${\chi}^2$=72.484, p=0.000), but not age (${\chi}^2$=0.910, p=0.340). Conclusions: Our analysis suggested that HERC4 is likely to be a diagnostic biomarker for lung cancer.

• 공업화학
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• 제19권3호
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• pp.310-315
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• 2008

본 연구에서는 실리카 코팅을 통하여 높은 내약품성을 갖는 황연입자를 제조하였다. 합성 과정에 수중 분산도 향상을 위한 중간체 제조의 최적화와 제조된 실리카로 코팅된 황연입자의 내약품성을 조사하였다. 합성과정에서 입자 생성에 가장 영향이 높은 변수인 pH와 반응온도에 따른 입자경의 변화를 관찰하였으며, homogenizer 이용하여 변화된 입자경에 따른 실리카 코팅에의 영향, 코팅 후 온도 및 pH의 변화에 따른 입자형상의 변화를 관찰하였다. 실험 결과로, 황연안료의 합성공정에서 생성용액의 pH가 낮을수록 합성 및 숙성온도가 높을수록 작고 균일한 입자를 얻을 수 있었다. 황연입자의 코팅 전 입자경이 작을수록 실리카 코팅이 우수하였다. 또한 충분한 마이크로캡슐화에 의한 실리카 코팅은 pH 9~10 및 반응온도 $90^{\circ}C$ 이상에서 얻을 수 있었다.

• Ecology and Resilient Infrastructure
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• 제5권1호
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• pp.11-18
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• 2018

Phosphorous remains as one of the most limiting nutrients to plant growth, second only to nitrogen. Research on use of biochar as a soil amendment for available phosphorus in temperate calcareous soils has limited studies compared with to tropical acidic soils. An incubation experiment to assess phosphorous availability in a biochar amended calcareous soil under inorganic (Fused superphosphate, FSP) and organic fertilizer (bone meal, BM) and respectively, at the dose of 40, 80 and $120mg\;P\;kg^{-1}$ was carried out. Soil was incubated at $25^{\circ}C$ for 70 days. Results show that the rate of increase in available P was proportional to the fertilizer application rate with or without biochar amendment. Biochar did not have a significant effect on soils amended with either fertilizeron the values of available P. However, time had a significant effect (p<0.001) on the amount of available P during the incubation period. Inorganic fertilizer treatments had recorded high amount of available P with time compared to organic fertilizer treatments. Organic fertilizer treatment sample were significantly not different from control and for most of the incubation time biochar acted as a soil conditioner. Further research is required to understand the holistic and long-term effect of biochar.

• Journal of Microbiology and Biotechnology
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• 제24권12호
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• pp.1673-1678
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• 2014

The interactive inhibitory effects of pH and chloride on the catalysis of laccase from Trametes versicolor were investigated by studying the alteration of inhibition characteristics of sodium chloride at different pHs for the oxidation of 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid). At pH 3.0, the addition of sodium chloride (50 mM) brought about a 40-fold increase in $K{_m}^{app}$ and a 4-fold decrease in $V_{max}{^{app}}$. As the pH increased to 7.0, the inhibitory effects of sodium chloride became significantly weakened. The mixed-inhibition mechanism was successfully used to quantitatively estimate the competitive and uncompetitive inhibition strengths by chloride at two different pHs (pH 3.0 and 6.0). At pH 3.0, the competitive inhibition constant, $K_i$, was 0.35 mM, whereas the uncompetitive inhibition constant, $K{_i}^{\prime}$, was 18.1 mM, indicating that the major cause of the laccase inhibition by chloride is due to the competitive inhibition step. At a higher pH of 6.0, where the inhibition of the laccase by hydroxide ions takes effect, the inhibition of the laccase by chloride diminished to a great extent, showing increased values of both the competitive inhibition constant ($K_i=23.7mM$) and uncompetitive inhibition constant ($K{_i}^{\prime}=324mM$). These kinetic results evidenced that the hydroxide anion and chloride share a common mechanism to inhibit the laccase activity.

• Journal of Microbiology and Biotechnology
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• 제2권3호
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• pp.161-165
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• 1992

The gene encoding the bacteriolytic enzyme cell wall peptidoglycan hydrolase from alkalophilic Bacillus sp. was cloned in E. coli using pBR322 as a vector. A recombinant plasmid, designated pYTR451, was isolated and the size of the cloned HindIII fragment was found to be 4.8 Kb. The cell wall hydrolysis activity of an extract of the E. coli harboring the recombinant plasmid pYTR 451 was detected by SDS- polyacrylamide gel containing 0.2% (w/v) purified cell wall of Bacillus sp. The molecular weight of the enzyme was estimated to be about 27, 000 corresponding to the molecular weight of the Bacillus sp. bacteriolytic enzyme. The recombinant plasmid was found to contain the fragment originated from Bacillus sp. YJ-451 chromosomal DNA by Southern hybridization.

• 한국미생물·생명공학회지
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• 제15권6호
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• pp.436-440
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• 1987

앞서 보고한 바와 같이 토양으로부터 분리한 K. pneumoniae NFB-320의 pullulanase 유전자를 pBR 322을 이용하여 E. coli에 cloning한 결과 약 14.4kb 의 재조합 plasmid DNA pYKL451을 얻었다. 이러한 pullulanase 유전자에 대한 유전적 정보를 얻기 위해 여러 가지 제한효소로 단일 혹은 이중 절단을 행하여 삽입된 pullulanase 유전자의 제한효소 절단지 도를 작성하였으며, E. coli(pYKL451)과 K. pneumoniae NFB-320이 생산하는 pullulanase의 효소적 특성을 조사하였다. 생산되는 두 균주의 효소는 50-55$^{\circ}C$ 부근에서 최적온도를 나타냈으며 최적pH는 모두 6.0이었다. 효소 안정성에 미치는 pH의 영향은 4$0^{\circ}C$에서 90min 간 방치했을 때 pH 5.0-10.0에서 안정하였으며 열안정성은 (pH6.0) 각 온도에서 한시간 처리하였을 때 4$0^{\circ}C$까지는 안정하였으나 5$0^{\circ}C$ 이상에서는 효소의 활성이 급격히 감소하였다.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.676-684
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• 1998

Baculovirus transfer and expression vectors with Hyphantria cunea nuclear polyhedrosis virus (HcNPV) were constructed. An initial transfer vector, pHcEV, constructed using HcNPV was previously reported (Park et al. 1993. J. Kor. Soc. Viral. 23: 141-151). Herein, the size of the vector was properly reduced, and a functionally perfect vector was constructed and named pHcEV-IV (6.7 kb). The vector has a 2.2-kb HcNPV DNA sequence in the 5'-flanking region of the vector's polyhedrin gene promoter. The 1.8-kb HcNPV DNA sequence, poly A signal sequence, T3 primer sequence, and 13 multicloning site sequences, in order, were ligated in front of the translation start codon of the polyhedrin gene. The cloning indicating marker lacZ gene was inserted into the pHcEV-IV, named pHcEV-IV-lacZ, and transferred into the wild-type virus. Recombinant expression virus, lacZ-HcNPV, was constructed by replacing the lacZ gene in the pHcEV-IV-lacZ with the polyhedrin gene of the wild-type virus. The recombinant virus was isolated from blue plaques that produce $\beta$-galactosidase without polyhedra. The lacZ gene insertion was confirmed by Southern hybridization analysis. The expression of the lacZ gene in Spodoptera frugiperda cells infected with the lacZ-HcNPV was examined by SDS-PAGE and colorimetric assay. One 116-kDa LacZ protein band appeared on the PAGE. The production rate of the $\beta$-galactosidase was approximately 50 international units (IU) per min per ml between 2 to 5 days postinfection (p.i.). The highest activity occurred at five days p.i. was 170 IU/min/$m\ell$. The enzyme activity first appeared about 20 h p.i. as measured by colorimetric assay.

• Macromolecular Research
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• 제13권6호
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• pp.467-476
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• 2005

The main objective of this study was to develop and characterize pH-sensitive biodegradable polymeric materials. For pH-sensitivity, we employed three kinds of moieties: 2-amino-3-(lH-imidazol-4-yl)-propionic acid (H), N-[4-( 4,6-dimethyl-pyrimidin-2ylsulfamoyl)-phenyl]succinamic acid (SM), and 2- {3-[ 4-( 4,6-dimethyl-pyrim­idin- 2-ylsulfamoyl)-phenylcarbamoyl]-propionylamino} -3-(3 H - imidazol-4-yl)-propionic acid (SH). The pH -sensitive diblock copolymers were synthesized by ring opening polymerization and coupling reaction from poly(ethylene glycol) (MPEG), $\varepsilon$-caprolactone (CL), D,L-lactide (LA) and pH-sensitive moieties. The pH-sensitive SH molecule was synthesized in a two-step reaction. The first step involved the synthesis of SHM, a methyl ester derivative of SH, by coupling reaction of SM and L-histidine methyl ester dihydrochloride, whereas the second step involved the hydrolysis of the same. The synthesized SM, SHM and SH molecules were characterized by FTIR, $^{1}H$-NMR and $^{13}C$-NMR spectroscopy, whereas diblock copolymers and pH-sensitive diblock copolymer were characterized by $^{1}H$-NMR and GPC analysis. The critical micelle concentrations were determined at various pH conditions by fluorescence technique using pyrene as a probe. The micellization and demicellization studies of pH-sensitive diblock copolymers were also done at different pH conditions. The pH-sensitivity was further established by acid-based titration and DLS analysis.