Comparative Analysis of Electrical Detection Methods of DNA Synthesis

Ahn, Jinhong,Kim, Seok Hyang,Woo, Jun-Myung,Park, Young June American Scientific Publishers 2012 Journal of Nanoscience and Nanotechnology Vol.12 No.7

<P>The incorporation of a complementary deoxynucleotide (dNTP) into a self-primed single-stranded DNA (ssDNA) attached to the surface of a sensor electrode generates an H+ charge that can be either trapped on the sensor surface or diffused into the surrounding solution. Electrical detection methods of DNA synthesis are based on these H+ kinetic mechanisms. The detection method that uses ISFET, which is related to the surface trapping mechanism, showed a better sensing signal than the induced charge detection method, which is related to the diffusion of H+ into the surrounding solution. The trapping reaction should be well-controlled, however, so that it would be stable under various surface conditions and temperatures. Moreover, the reaction should be reversible, and the reaction parameters should be well-sustained in the subsequent synthesis cycles. For the induced charge method, the AC current level was too small to be detected using an ordinary amplifier circuit with the same sensor size as that of ISFET. Consequently, the sensor operation sustainability and signal-to-noise ratio characteristics should be addressed carefully in the selection of the proper sensor type.</P>

Analysis of Sensing Mechanisms in a Gold-Decorated SWNT Network DNA Biosensor

Jinhong Ahn,Seok Hyang Kim,Jaeheung Lim,Jung Woo Ko,Chan Hyeong Park,Young June Park 대한전자공학회 2014 Journal of semiconductor technology and science Vol.14 No.2

We show that carbon nanotube sensors with gold particles on the single-walled carbon nanotube (SWNT) network operate as Schottky barrier transistors, in which transistor action occurs primarily by varying the resistance of Au-SWNT junction rather than the channel conductance modulation. Transistor characteristics are calculated for the statistically simplified geometries, and the sensing mechanisms are analyzed by comparing the simulation results of the MOSFET model and Schottky junction model with the experimental data. We demonstrated that the semiconductor MOSFET effect cannot explain the experimental phenomena such as the very low limit of detection (LOD) and the logarithmic dependence of sensitivity to the DNA concentration. By building an asymmetric oncentricelectrode model which consists of serially-connected segments of CNTFETs and Schottky diodes, we found that for a proper explanation of the experimental data, the work function shifts should be ~ 0.1 eV for 100 pM DNA concentration and ~ 0.4 eV for 100 μM.

Analysis of Sensing Mechanisms in a Gold-Decorated SWNT Network DNA Biosensor

Ahn, Jinhong,Kim, Seok Hyang,Lim, Jaeheung,Ko, Jung Woo,Park, Chan Hyeong,Park, Young June The Institute of Electronics and Information Engin 2014 Journal of semiconductor technology and science Vol.14 No.2

We show that carbon nanotube sensors with gold particles on the single-walled carbon nanotube (SWNT) network operate as Schottky barrier transistors, in which transistor action occurs primarily by varying the resistance of Au-SWNT junction rather than the channel conductance modulation. Transistor characteristics are calculated for the statistically simplified geometries, and the sensing mechanisms are analyzed by comparing the simulation results of the MOSFET model and Schottky junction model with the experimental data. We demonstrated that the semiconductor MOSFET effect cannot explain the experimental phenomena such as the very low limit of detection (LOD) and the logarithmic dependence of sensitivity to the DNA concentration. By building an asymmetric concentric-electrode model which consists of serially-connected segments of CNTFETs and Schottky diodes, we found that for a proper explanation of the experimental data, the work function shifts should be ~ 0.1 eV for 100 pM DNA concentration and ~ 0.4 eV for $100{\mu}M$.

Power Control of a Grid-Connected Hybrid Generation System with Photovoltaic/Wind Turbine/Battery Sources

Jinhong JEON,Seulki KIM,Changhee CHO,Jonbo AHN,Jangmok KIM 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

A grid-connected hybrid distributed generation system, composed of PV(photovoltaic) array, wind turbine and BESS(battery energy storage system), is proposed for various power transfer functions to the distribution network. The proposed system has several operation modes which are normal operation, power dispatching, and power averaging, according to coordinate control of the BESS and grid inverter. PV array and wind turbine are individually controlled to operate at the maximum power point for the most use of renewable energy. The BESS operates as an energy buffer to flexibly shift the generation from the renewable energy sources without excessively frequent shifts between battery charging and discharging. A grid interface inverter regulates the generated power injection into the grid. Developed prototype system design and experimental results are presented to demonstrate the performance and to validate the proposed system during its operation modes.

Removal Characteristics of Algae for Drinking Water Treatment Plant Using Natural Coagulants

Ahn, Kwang Ho,Kim, I-tae,Kim, Weonjae,Lim, Hyunman,Jung, Jinhong Global Vision School Publication 2016 International journal of bio-science & bio-technol Vol.8 No.3

Postoperative radiotherapy for ependymoma

Jinhong Jung,Wonsik Choi,Seung Do Ahn,Jin Hong Park,Su Ssan Kim,Young Seok Kim,Sang Min Yoon,Si Yeol Song,Sang-Wook Lee,Jong Hoon Kim,Eun Kyung Choi 대한방사선종양학회 2012 Radiation Oncology Journal Vol.30 No.3

Purpose: To evaluated the patterns of failure, survival rate, treatment-related toxicity and prognostic factors in postoperative radiotherapy of patients with ependymoma. Materials and Methods: Thirty patients who underwent surgery and postoperative radiotherapy for ependymoma between the period of June 1994 and June 2008 were reviewed retrospectively. The age of patients ranged from 21 months to 66 years (median, 19 years). Seventeen patients had grade II ependymoma, and 13 had grade III anaplastic ependymoma according to the World Health Organization grading system. The postoperative irradiation was performed with 4 or 6 MV photon beam with median dose of 52.8 Gy (range, 45 to 63 Gy), and radiation field including 2 cm beyond the preoperative tumor volume. Median follow-up period was 51 months (range, 12 to 172 months). Results: Fourteen out of 30 (46.7%) patients experienced recurrence, and 12 of those died. Among those 14 patients who experienced recurrence, 11 were in-field and 3 were out-of-field recurrence. The 5-year overall survival (OS) and progression-free survival (PFS) rates were 66.7% and 56.1%, respectively. On univariate analysis, tumor grade was a statistically significant prognostic factor for OS and PFS. There were two complications after surgery and postoperative radiotherapy, including short stature and facial palsy on the left side. Conclusion: We observed good survival rates, and histologic grade was a prognostic factor affecting the OS and PFS. Almost all recurrence occurred in primary tumor site, thus we suggest further evaluation on intensity-modulated radiotherapy or stereotatic radiosurgery for high-risk patients such as who have anaplastic ependymoma.

Postoperative radiotherapy for ependymoma

Jung, Jinhong,Choi, Wonsik,Ahn, Seung Do,Park, Jin Hong,Kim, Su Ssan,Kim, Young Seok,Yoon, Sang Min,Song, Si Yeol,Lee, Sang-Wook,Kim, Jong Hoon,Choi, Eun Kyung The Korean Society for Radiation Oncology 2012 Radiation Oncology Journal Vol.30 No.4

Purpose: To evaluated the patterns of failure, survival rate, treatment-related toxicity and prognostic factors in postoperative radiotherapy of patients with ependymoma. Materials and Methods: Thirty patients who underwent surgery and postoperative radiotherapy for ependymoma between the period of June 1994 and June 2008 were reviewed retrospectively. The age of patients ranged from 21 months to 66 years (median, 19 years). Seventeen patients had grade II ependymoma, and 13 had grade III anaplastic ependymoma according to the World Health Organization grading system. The postoperative irradiation was performed with 4 or 6 MV photon beam with median dose of 52.8 Gy (range, 45 to 63 Gy), and radiation field including 2 cm beyond the preoperative tumor volume. Median follow-up period was 51 months (range, 12 to 172 months). Results: Fourteen out of 30 (46.7%) patients experienced recurrence, and 12 of those died. Among those 14 patients who experienced recurrence, 11 were in-field and 3 were out-of-field recurrence. The 5-year overall survival (OS) and progression-free survival (PFS) rates were 66.7% and 56.1%, respectively. On univariate analysis, tumor grade was a statistically significant prognostic factor for OS and PFS. There were two complications after surgery and postoperative radiotherapy, including short stature and facial palsy on the left side. Conclusion: We observed good survival rates, and histologic grade was a prognostic factor affecting the OS and PFS. Almost all recurrence occurred in primary tumor site, thus we suggest further evaluation on intensity-modulated radiotherapy or stereotatic radiosurgery for high-risk patients such as who have anaplastic ependymoma.

Radiation-induced liver disease after stereotactic body radiotherapy for small hepatocellular carcinoma: clinical and dose-volumetric parameters

Jung, Jinhong,Yoon, Sang Min,Kim, So Yeon,Cho, Byungchul,Park, Jin-hong,Kim, Su Ssan,Song, Si Yeol,Lee, Sang-wook,Ahn, Seung Do,Choi, Eun Kyung,Kim, Jong Hoon BioMed Central 2013 Radiation oncology Vol.8 No.-

<P><B>Background</B></P><P>To investigate the clinical and dose–volumetric parameters that predict the risk of radiation-induced liver disease (RILD) for patients with small, unresectable hepatocellular carcinoma (HCC) treated with stereotactic body radiotherapy (SBRT).</P><P><B>Methods</B></P><P>Between March 2007 and December 2009, 92 patients with HCC treated with SBRT were reviewed for RILD within 3 months of completing treatment. RILD was evaluated according to the Common Terminology Criteria for Adverse Events, version 3.0. A dose of 10–20 Gy (median, 15 Gy) per fraction was given over 3–4 consecutive days for a total dose of 30–60 Gy (median, 45 Gy). The following clinical and dose–volumetric parameters were examined: age, gender, Child-Pugh class, presence of hepatitis B virus, gross tumor volume, normal liver volume, radiation dose, fraction size, mean dose to the normal liver, and normal liver volumes receiving from < 5 Gy to < 60 Gy (in increments of 5 Gy).</P><P><B>Results</B></P><P>Seventeen (18.5%) of the 92 patients developed grade 2 or worse RILD after SBRT (49 patients in grade 1, 11 in grade 2, and 6 in ≥ grade 3). On univariate analysis, Child-Pugh class was identified as a significant clinical parameter, while normal liver volume and normal liver volumes receiving from < 15 Gy to < 60 Gy were the significant dose–volumetric parameters. Upon multivariate analysis, only Child-Pugh class was a significant parameter for predicting grade 2 or worse RILD.</P><P><B>Conclusions</B></P><P>The Child-Pugh B cirrhosis was found to have a significantly greater susceptibility to the development of grade 2 or worse RILD after SBRT in patients with small, unresectable HCC. Additional efforts aimed at testing other models to predict the risk of RILD in a large series of HCC patients treated with SBRT are needed.</P>

PSAML과 Topology String 데이터베이스를 이용한 웹 기반 단백질 구조 비교 시스템

김진홍(Jinhong Kim),안건태(Geontae Ahn),변상희(Sanghee Byun),이수현(Suhyun Lee),이명준(Myungjoon Lee) 한국정보과학회 2004 한국정보과학회 학술발표논문집 Vol.31 No.1B

단백질의 기능은 단백질의 구조에 따라 결정되며, 새로운 단백질의 기능을 파악하기 위하여 이미 밝혀진 단백질의 기능과 구조를 비교하는 방법이 사용되고 있다. 단백질 구조를 비교하는 방법은 단백질 구조를 표현하는 방법에 따라 다양하게 개발되고 있으며, 보다 효과적으로 관련된 연구자들이 자신의 연구에 활용하기 위해서는 빠르고 쉽게 활용할 수 있는 인터페이스를 제공하는 도구가 필요하다. 본 논문에서는 PDB 데이터베이스에서 제공하는 단백질 정보를 이용하여 PSAML 및 Topology String 데이터베이스를 구축하고 이를 바탕으로 웹 기반에서 단백질 구조 비교를 보다 빠르고 효과적으로 수행하는 시스템에 대하여 기술한다. PSAML 데이터베이스는 단백질 구조를 단백질 이차구조 및 그들 사이의 관계를 포함하는 PSAML 데이터를 제공하며, Topology String 데이터베이스는 단백질 구조를 단백질 이차구조를 하나의 문자로 기술하여 아미노산 순서와 위상학적(공간적) 정보를 포함하는 문자열로 단백질 구조 정보를 제공한다. 이를 이용하여 구축된 웹 기반 단백질 구조 비교 시스템은 Topology String 정렬 방법을 통하여 보다 빠르게 유사성이 높은 부분 구조를 찾는 방법을 제공한다.

압축센싱에 기반한 수동소나 DEMON 분석

김진홍(Jinhong Kim),김준한(Junhan Kim),심병효(Byonghyo Shim),안재균(Jae-Kyun Ahn),김성일(Seongil Kim),홍우영(Wooyoung Hong) 한국소음진동공학회 2017 한국소음진동공학회 학술대회논문집 Vol.2017 No.4