• Journal of Electrochemical Science and Technology
• /
• 제8권1호
• /
• pp.43-52
• /
• 2017

In this paper, for the first time, the electroanalytical study of Triethylenediamine, TEDA was done on a typically graphene modified carbon paste electrode (Gr/CPE) in pH=10.5 of phosphate buffer solutions (PBS). The surface morphology of the bare and modified electrodes was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electro-oxidation of TEDA was investigated at the surface of modified electrode. The results revealed that the oxidation peak current of TEDA at the surface of Gr/CPE is 2.70 times than that shown at bare-CPE. A linear calibration plot was observed in the range of 1.0 to 202.0 ppm. In this way, the detection limit was found to be 0.18 ppm. The method was then successfully applied to determination of TEDA in aqueous samples obtained from two kinds of activated carbon from the masks of war. On the other hand, density functional theory (DFT) method at B3LYP/6-311++G** level of theory and a conductor-like Polarizable Continuum Model (CPCM) was used to calculate the $pK_a$ values of TEDA. The energies of lowest unoccupied molecular orbital ($E_{LUMO}$) and highest occupied molecular orbital ($E_{HOMO}$), gap energy (${\Delta}E$) and some thermodynamic parameters such as Gibbs free energy of TEDA and its conjugate acid ($HT^+$) were calculated. The results of calculated $pK_a$ were found to be in good agreement with the experimental values.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제31권4호
• /
• pp.316-321
• /
• 2005

Ameloblastoma is the most common odontogenic tumor of the jawbones, but the origin of this tumor has been remained to be unproven. Cytokeratins (CKs) are specific intermediate filament of epithelial cells, and vimentin is expressed in mesenchymal cells. The immunohistochemical detection of different CKs and vimentin has made it easier to know the origin of tumor. Paraffin-embedded tissue sections from 15 ameloblastomas and 1 ameloblastic carcinoma were used for immunohistochemical evaluation of CK 7, 8, 13, 14, 19 and vimentin. Their expression is evaluated in different tumor cells, which are observed in different type of tumors. In the follicular and reticular subtype, central stellate cells of tumor nests expressed CK 8, 14, 19 and peripheral columnar cells expressed CK 14. CK 7, and 13 were not expressed. Vimentin was detected in fibrous stroma around tumor nest, not in tumor cells. The tumor cells of ameloblastic carcinoma expressed CK 7, 14 and 19, but CK 8 was more weakly stained than that in ameloblastoma. Central stellate cells and peripheral columnar cells of acanthomatous subtype showed same expression pattern with others. Meta plastic squamous cells expressed CK 8, 14, 19 and keratinizing squamous cells expressed CK 13, 19. CK 7 and vimentin were not detected in tumor cells and vimentin was expressed in fibrous stroma. Most of the tumor cells of ameloblastoma showed CK 14 and CK 19 and did not express CK 7 and vimentin. These findings were similar to the immunophenotype of dental lamina. And these results will be beneficial to differential diagnosis of odontogenic tumors and other kind of tumors arising at the oral cavity.

• 한국통신학회논문지
• /
• 제32권5C호
• /
• pp.542-549
• /
• 2007

편미분 방정식을 도입하여 새로운 영상처리 기술을 개발하려는 연구가 활발히 진행 중이며, 특히 확산 방정식을 풀어 잡음 제거, 영상 복원, 에지 검출 및 영상 분할 등에 응용할 수 있는 이미지 확산 알고리즘에 관심이 높다. 본 논문에서는 기존의 비등방성 확산 방식이 결국은 커널 크기가 작은 적응 필터링 방식과 동일한 효과를 낸다는 것을 보이고, 확산 과정에서 선형 필터의 단점을 보완할 수 있도록 가중 미디언(WM, Weighted Median) 필터를 적용한 새로운 확산 기법을 제안하였다. 제안된 WM 필터가 비등방성 커널을 갖도록 필터계수에 대응하는 가중치들을 이미지의 국부적인 변화량에 따라 적응적으로 가변할 수 있는 기법을 제안하였다. 뿐만 아니라 반복 과정에서의 확산 속도를 증가할 수 있도록 커널의 크기를 증가시키기 위한 방안도 제시하였다. 실제 영상을 사용한 실험을 통하여 제안된 방식이 기존의 방식에 비해 잡음 제거 (특히 임펄스성 잡음) 특성이나 에지 보존 특성이 더 우수하다는 것을 보였다. 또한 기존의 방식에 비해 확장된 크기를 갖는 커널을 이용함으로써 확산 속도를 높일 수 있다는 것을 보였다.

• Investigative Magnetic Resonance Imaging
• /
• 제14권2호
• /
• pp.139-144
• /
• 2010

췌장의 중복낭은 성인에서 매우 드문 병변으로 췌장의 다양한 낭성 병변들과 감별진단이 용이하지 않다. 저자들은 성인에서 발견된 췌장 중복낭의 영상 소견들을 알아보고 임상 소견 및 낭종액 내 종양표지자를 포함한 검사 결과를 함께 보고하고자 한다. 자기공명 영상과 H-1 자기공명분광법 소견들은 췌장 중복낭의 위치, 형태, 낭종액의 특성을 진단하고 주변 구조물과의 경계를 구분하여 보다 정밀한 수술적 접근에 유용한 정보를 제공한다.

• 한국산학기술학회논문지
• /
• 제16권11호
• /
• pp.7582-7588
• /
• 2015

광대역 통신을 위한 대표적인 비동기 전송방식인 TR 방식은 동기식 레이크 수신기에 비하여 하드웨어 복잡도가 낮아서 주목을 받아왔다. 최근에는 TR 방식보다 효과적인 데이터 전송을 할 수 있는 BCM 방식이 효율적인 비동기 방식으로 인정받고 있다. BCM 방식의 수신기로는 CMSA 방식이 널리 사용되고 우수한 성능을 가진 것으로 알려져 있다. 본 논문에서는 프레임간 혹은 심볼간 간섭이 존재하는 환경에서, BCM으로 송신된 신호에 대하여 CMSA 방식보다 성능이 우수한 수신기를 제안한다. 제안하는 방식은 TR 방식에서와 같이 상관기를 이용한다. TR방식에서는 하나의 기준신호에 근거한 상관기를 사용하는 반면, 제안하는 방식은 BCM으로 전송된 신호를 복조하기 위하여 블록 코드를 이용한 블록 코드 상관기를 사용한다. 모의실험을 통하여, 제안하는 방식은 CMSA 방식보다 비트오율 측면에서 더 우수한 성능을 나타낸다. 특히, 채널모델 CM4 에서 BER = $10^{-3}$ 일 때, SNR 측면에서 5 dB 이득을 얻을 수 있었다.

• 한국정보통신학회논문지
• /
• 제8권2호
• /
• pp.509-515
• /
• 2004

폐 기능 검사는 임상에서 환자의 진단 및 치료 판단에 널리 이용되고 있을 뿐 아니라 폐의 연구, 특히 폐의 생리학 및 폐질환의 역학 연구에 일찍부터 사용되어 왔다. 여러 가지 폐 기능 검사 중 가장 쉽고 경제적으로 시행할 수 있는 기본적인 검사법으로 폐활량 검사법(Spirometer)이 있다. 폐활량 검사기는 호흡 기체의 용적 유량의 순간적인 변화량을 측정하는 의학 기기이다. 과거에는 기계식 폐활량기가 주로 사용되었으며, 현재까지도 많이 사용되는 방법은 유체 흐름의 "양" 변화를 유체의 압력 변화로 전환시키는 차압식 방식이다. 그러나 이러한 형태는 압력 손실과 유지 보수가 힘들고, 특성 검사 주기가 짧은 단점을 가지고 있다. 본 논문에서 구현하고자 하는 것은 관성의 오차 및 압력의 오차에 영향을 거의 받지 않는, 그리고 반영구적으로 사용이 가능한 초음파 센싱 방식을 이용한 임베디드 환경의 호흡 량 측정기의 개발을 최종 목표로 하여, 호흡 기체 특성에 적합한 센서, 신호 측정 구현 회로를 포함한 유량 측정 단말부 개발과 측정신호를 이용한 호흡 측정 알고리즘과 진단 알고리즘 구현에 중점을 두었다.

• Archives of Pharmacal Research
• /
• 제22권3호
• /
• pp.243-248
• /
• 1999

Sialic acids are key determinants for biological processes, such as cell-cell interaction and differentiation. Sialyltransferases contribute to the diversity in carbohydrate structure through their attachment of sialic acid in various terminal positions on glycolipid and glycoprotein (N-linked and O-linked) carbohydrate groups. Gal$\beta$ 1,3(4)GlcNAc $\alpha$2,3-sialyltransferase (ST3Gal III) is involved in the biosynthesis of $sLe^{X}$ and sLe^{a}$ known as selection ligands and tumor-associated carbohydrate structures. The appearance and differential distribution of ST3Gal III mRNA during mice embryogenesis [embryonic (E) days; E9, E11, E13, E15] were investigated by in situ hybridization with digoxigenin-labeled RNA probes coupled with alkaline phosphatase detection. On E9, all tissues were positive for ST3Gal III mRNA expression whereas ST3Gal III mRNA on E11 was not detected throughout all tissues. On E13, ST3GAl III mRNA was expressed in different manner in various tissues. In this stage, ST3Gal III mRNA was positive only in the liver, pancreas and bladder. On E15, specific signal for ST3GAl III was detected in the liver, lung and forebrain. These results indicate that ST3Gal III is differently expressed at developmental stages of mice embryo, and this may be importantly related with regulation of organogenesis in mice.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2018년도 학술발표회
• /
• pp.148-148
• /
• 2018

Land subsidence caused by excessive groundwater pumping is a serious hydro-geological hazard. The spatial variability in land use, unbalanced groundwater extraction and aquifer characteristics are the key factors which make the problem more difficult to monitor using conventional methods. This study uses the European Space Agency (ESA) Sentinel satellites to investigate and monitor land subsidence varying with different land covers and groundwater use in the arid Quetta valley, Pakistan. The Persistent Scattering Differential Interferometry of Synthetic Aperture Radar (PS-DInSAR) method was used to develop 28 subsidence interferograms of the study area for the period between 16 Oct 2014 and 06 Oct 2016 using ESA's Sentinel-1 SAR data. The uncertainty of DInSAR result is first minimized by removing the dynamic effect caused by atmospheric factors and then filtered using the radar Amplitude Dispersion Index (ADI) to select only the stable pixels. Finally the subsidence maps were generated by spatially interpolating the land subsidence at the stable pixels, the comparison of DInSAR subsidence with GPS readings showed an R 2 of 0.94 and mean absolute error of $5.7{\pm}4.1mm$. The subsidence maps were also analysed for the effect of aquifer type and 4 land covers which were derived from Sentienl-2 multispectral images. The analysis show that during the two year period, the study area experienced highly non-linear land subsidence ranging from 10 to 280 mm. The subsidence at different land covers was significantly different from each other except between the urban and barren land. The barren land and seasonally cultivated area show minor to moderate subsidence while the orchard and urban area with high groundwater extraction rate showed excessive amount of land subsidence. Moreover, the land subsidence and groundwater drawdown was found to be linearly proportional to each other.

• Nano
• /
• 제13권11호
• /
• pp.1850131.1-1850131.19
• /
• 2018

In this paper, an electrochemical sensor for epinephrine (EP), a neurotransmitter was developed by anchoring molecularly imprinted polymeric matrix (MIP) on the surface of gold-coated quartz crystal electrode of electrochemical quartz crystal microbalance (EQCM) using starch nanoparticles (Starch NP) - reduced graphene oxide (RGO) nanocomposite as polymeric format for the first time. Use of EP in therapeutic treatment requires proper dose and route of administration. Proper follow-up of neurological disorders and timely diagnosis of them has been found to depend on EP level. The MIP sensor was developed by electrodeposition of starch NP-RGO composite on EQCM electrode in presence of template EP. As the imprinted sites are located on the surface, high specific surface area enables good accessibility and high binding affinity to template molecule. Differential pulse voltammetry (DPV) and piezoelectrogravimmetry were used for monitoring binding/release, rebinding of template to imprinted cavities. MIP-coated EQCM electrode were characterized by contact angle measurements, AFM images, piezoelectric responses including viscoelasticity of imprinted films, and other voltammetric measurements including direct (DPV) and indirect (using a redox probe) measurements. Selectivity was assessed by imprinting factor (IF) as high as 3.26 (DPV) and 3.88 (EQCM). Sensor was rigorously checked for selectivity in presence of other structurally close analogues, real matrix (blood plasma), reproducibility, repeatability, etc. Under optimized conditions, the EQCM-MIP sensor showed linear dynamic ranges ($1-10{\mu}M$). The limit of detection 40 ppb (DPV) and 290 ppb (EQCM) was achieved without any cross reactivity and matrix effect indicating high sensitivity and selectivity for EP. Hence, an eco-friendly MIP-sensor with high sensitivity and good selectivity was fabricated which could be applied in "real" matrices in a facile manner.

• 대한두경부종양학회지
• /
• 제34권2호
• /
• pp.29-34
• /
• 2018

Background/Objectives: The aim of this study was to investigate the diagnostic value of i-scan in the differential diagnosis of oral cavity leukoplakia based on visualization of abnormal vascular features. Materials & Methods: Thirty- one patients with oral cavity leukoplakia were enrolled in the study. Images of their oral cavity obtained using conventional white light endoscopy and an i-scan-enhanced endoscopy (Pentax DEFINA EPK-3000 Video Processors, with Pentax VNLJ10) were reviewed. The microvascular features of the lesions and vascular changes were analyzed and the results were compared with the histopathologic diagnosis. Results: Among the 31 oral cavity leukoplakia patients, 8 (25.8%) patients revealed hyperkeratosis, 10 (31.2%) low-grade dysplasia, 5 (16.2%) high-grade dysplasia and 8 (25.8%) invasive squamous cell carcinoma on histopathologic examination. Using i-scan-enhanced endoscopy, we could found abnormal vascular change with neoplastic neoangiogenesis in most high-grade dysplasia or invasive cancer in oral cavity. (high-grade dysplasia: 4/5 [80.0%], and invasive squamous cell carcinoma: 7/8 [87.5%]). Conclusion: i-scan-enhanced endoscopy could be a useful optical technique for the diagnosis of oral cavity leukoplakia. Our results suggest that i-scan may be a promising diagnostic tool in the early detection of suspected oral mucosal lesion.