독일 핵의학의 현황

정준기 대한핵의학회 1997 핵의학 분자영상 Vol.31 No.3

분자핵의학영상 개관

정준기 대한핵의학회 2004 핵의학 분자영상 Vol.38 No.2

Molecular imaging provides a visualization of normal as well as abnormal cellular processes at a molecular or genetic level rather than at a anatomical level. Conventional medical imaging methods utilize the imaging signals produced by nonspecific physico-chemical interaction. However, molecular imaging methods utilize the imaging signals derived from specific cellular or molecular events. Because molecular and genetic changes precede anatomical change in the course of disease development, molecular imaging can detect early events in disease progression. In the near future, through molecular imaging we can understand basic mechanisms of disease, and diagnose earlier and, subsequently, treat earlier intractable diseases such as cancer, neuro-degenerative diseases, and immunologic disorders. In beginning period, nuclear medicine started as a molecular imaging, and has had a leading role in the field of molecular imaging. But recently molecular imaging has been rapidly developed. Besides nuclear imaging, molecular imaging methods such as optical imaging, magnetic resonance imaging are emerging. Each imaging modalities have their advantages and weaknesses. The opportunities from molecular imaging look bright. We should try nuclear medicine continues to have a leading role in molecular imaging. (Korean J Nucl Med 38(2):111-114, 2004)

다양한 질소분압에서 펄스레이저법으로 성장된 AlN박막의 특성

정준기,하태권 한국소성가공학회 2019 소성가공 : 한국소성가공학회지 Vol.28 No.1

Aluminum nitride (AlN) is used by the semiconductor industry, and is a compound that is required when manufacturing high thermal conductivity. The AlN films with c-axis orientation and thermal conductivity characteristic were deposited by using the Pulsed Laser Deposition (PLD). The AlN thin films were characterized by changing the deposition conditions. In particular, we have researched the AlN thin film deposited under optimal conditions for growth atmosphere. The epitaxial AlN films were grown on sapphire (c-Al2O3) single crystals by PLD with AlN target. The AlN films were deposited at a fixed temperature of 650 °C, while conditions of nitrogen (N2) pressure were varied between 0.1 mTorr and 10 mTorr. The quality of the AlN films was found to depend strongly on the N2 partial pressure that was exerted during deposition. The X-ray diffraction studies revealed that the integrated intensity of the AlN (002) peak increases as a function the corresponding Full width at half maximum (FWHM) values decreases with lowering of the nitrogen partial pressure. We found that highly c-axis orientated AlN films can be deposited at a substrate temperature of 650 °C and a base pressure of 2×10-7 Torr in the N2 partial pressure of 0.1 mTorr. Also, it is noted that as the N2 partial pressure decreased, the thermal conductivity increased.

Y(NO3)3•6H2O 첨가된 AlN 소결체의 기계적 및 열전도도 특성

정준기,이정훈,하태권 한국소성가공학회 2018 소성가공 : 한국소성가공학회지 Vol.27 No.1

Aluminum nitride (AlN) is used by the semiconductor industry that has requirements for high thermal conductivity. The theoretical thermal conductivity of single crystal AlN is 320W/mK. Whereas, the values measured for polycrystalline AlN ceramics range from 20 W/mK to 280 W/mK. The variability is strongly dependent upon the purity of the starting materials and non-uniform dispersibility of the sintering additive. The conventional AlN sintering additive used yttria (Y2O3), but the dispersibility of the powder in the mixing process was important. In this study, we investigated the mechanical and thermal conductivity of yttrium nitrate (Y(NO3)3•6H2O), as a sintering additive in order to improve the dispersibility of Y2O3. The sintering additives content was in the range of 2 to 4.5wt.%. The density of AlN gradually increased with increasing contents of sintering additive and the flexural strength gradually increased as well. The flexural strength of the sintered body containing 4 wt% of Y2O3 and Y(NO3)3•6H2O was 334.1 MPa and 378.2 MPa, respectively. The thermal conductivities were 189.7W/mK and 209.4W/mK, respectively. In the case of hardness, there was only a slight difference and the average value was about 10 GPa. Therefore, densification, density and strength values were found to be proportional to its content. It was confirmed that AlN using Y(NO3)3•6H2O displayed relatively higher thermal conductivity and mechanical properties than the Y2O3.

갑상선암에서 PET의 이용

정준기 대한내분비학회 2004 Endocrinology and metabolism Vol.19 No.1

Lesionalized Therapy beyond Personalized Therapy in Cancer Management

정준기,김미정,윤혜원 대한의학회 2014 Journal of Korean medical science Vol.29 No.10

Cooperative Stereocontrol by Proximal and Distal Chlorine Substituents in the Chiral Lewis Base-catalyzed Kinetic Resolution of cis-Vinyl Epoxide

정준기,김재희,김한나,이승엽,최준호,정원진 대한화학회 2019 Bulletin of the Korean Chemical Society Vol.40 No.8

Mechanistic study on the stereocontrolling role of chlorine substituents by control experiments and computational analysis.

성 안토니의 영성

정준기 광신대학교 출판부 2012 光神論壇 Vol.21 No.-

업싸이클링된 암모늄 파라텡스텐의 열적 및 화학적 분해법 비교

정준기,온진호,김성진,박상엽,Chung, Jun-Ki,On, Jin-Ho,Kim, Sung-Jin,Park, Sang-Yeup 한국재료학회 2015 한국재료학회지 Vol.25 No.6

The possibility of using the chemical precipitation method of up-cycled ammonium paratungstate (APT) was studied and compared with the thermal decomposition method. $WO_3$ particles were synthesized by chemical precipitation method using a 1:2 weight ratio of APT: Di-water. For thermal decomposition, APT powder was heated for 4h at $600^{\circ}C$ in air atmosphere. The reaction products were characterized by X-ray diffraction (XRD), X-ray fluorescence spectrometer (XRF), particle size analyzer (PSA), and field emission-scanning electron microscopy (FE-SEM). Thermogravimetric analysis (TGA) of the up-cycled APT allowed for the identification of the sequence of decomposition and reduction reactions that occurred during the heat treatment. TGA data indicated a total weight loss of 10.78% with the reactions completed in $658^{\circ}C$. The XRD results showed that APT completely decomposed to $WO_3$ by thermal decomposition and chemical precipitation. The particle size of the synthesized $WO_3$ powders by thermal decomposition with 2 h of planetary milling was around $2{\mu}m$ During the chemical precipitation process, the particle size of the synthesized $WO_3$ powders showed a round-shape with ${\sim}0.6{\mu}m$ size.

Radioiodine Therapy in Differentiated Thyroid Cancer: The First Targeted Therapy in Oncology

정준기,천기정 대한내분비학회 2014 Endocrinology and metabolism Vol.29 No.3

Iodide uptake across the membranes of thyroid follicular cells and cancer cells occurs through an active transport process mediated by the sodium-iodide symporter (NIS). The rat and human NIS-coding genes were cloned and identified in 1996. Evaluation of NIS gene and protein expression is critical for the management of thyroid cancer, and several approaches to increase NIS levels have been tried. Identification of the NIS gene has provided a means of expanding its role in radionuclide therapy and molecular target-specific theragnosis (therapy and diagnosis using the same molecular target). In this article, we describe the relationship between NIS expression and the thyroid carcinoma treatment using I-131 and alternative therapeutic approaches.