• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.211-221
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• 2022

Recently, the demand for the cultivation of upland soil has been increasing, and the rate of conversion of paddy soil into upland soil is also increasing. Theincrease in uneven precipitation due to climate change has resulted in dramatic effects of waterlogging stress on upland crops. Therefore, the present study was conducted to investigate the changes in growth characteristics and the expression patterns of proteins at the two-leaf stage of adzuki beans. The domestic cultivar, Arari (Miryang No. 8), was used to test waterlogging stress. At the two-leaf stage of adzuki beans, plant height slightly decreased androot fresh weight showed significant changes after 3 days of waterlogging treatment. Chlorophyll content was also significantly different after 3 days of waterlogging treatment compared to its content in control plants. Using two-dimensional gel electrophoresis, more than 400 protein spots were identified. Twenty-one differentially expressed proteins from the two-leaf stage were analyzed using linear trap quadrupole-Fourier transform-ion cyclotron resonance mass spectrometry. Of these 21 proteins, 9 were up-regulated and 12 were down-regulated under waterlogging treatment. Protein information resource (https://pir.georgetown.edu/) categories were assigned to all 49 proteins according to their molecular function, cellular component localization, and biological processes. Most of the proteins were found to be involved in the biological process, carbohydrate metabolism and were localized in chloroplasts.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.7 no.2
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• pp.105-111
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• 2021

⁸⁹Zr is a positron-emitting radioisotope, which has known as well-suited radioisotope for use in a monoclonal antibody-based imaging agent for immuno-PET. The purpose of this study was to quantitatively evaluate the diagnostic ability of general trastuzumab and thio-trastuzumab as HER2 positive receptors based on Df hexadentate iron chelator. Desferrioxamine-p-SCN (Df-Bz-NCS) and desferroixamine-maleimide (Df-Mal) were purchased from Macrocyclics (Dallas, TX, USA). The trastuzumab was purchased from Roche (Schweiz), and thio-trastuzumab was obtained from professor Hyo-Jeong Hong group (Kangwon National University). The radioisotope ⁸⁹Zr was produced by domestic purification system and KIRAMS using medical cyclotron (50 MeV, Scantronix). The conjugates of Df-trastuzumab and Df-thio-trastuzumab were prepared with Df-Bz-NCS and Df-Mal under basic aqueous solution (pH 8-9) at room temperature, respectively. The conjugates purified by PD-10 column were mixed with dried ⁸⁹Zr chloride. ⁸⁹Zr-labeled conjugates were purified and concentrated by Amicon ultra centrifugal filter. The preparation step and time of ⁸⁹Zr-labeled conjugates was shorted as 4 steps within 2 hours. ⁸⁹Zr-labeled conjugates showed the highly radiochemical purity of over 98%, and were very stable until 7 days by the analysis of radio-ITLC method. Each radio-labeled conjugates were also exhibited the highly stability in both PBS buffer and mouse serum. Immuno-PET imaging of ⁸⁹Zr-labeled conjugates in mice bearing gastric cancer xenograft tumors with HER2 expression showed high tumor uptake in the NCI-N87 HER2-expressing. However, ⁸⁹Zr-Df-Mal-thio-trastuzumab showed a relatively lower tumor-to-background ratio than ⁸⁹Zr-Df-Bz-trastuzumab, as well as whole-body distribution. In the results, ⁸⁹Zr-Df-Bz-trastuzumab was evaluated to have a relatively higher HER2 diagnostic ability than ⁸⁹Zr-Df-Mal-thio-trastuzumab.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4102-4110
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• 2022

Aiming at high-power and long-pulse operation up to 1000 s, some improvements have been made for both 2.45 GHz and 4.6 GHz lower hybrid (LH) systems during the recent 5 years. At first, the guard limiters of the LH antennas with graphite tiles were upgraded to tungsten, the most promising material for plasma facing components in nuclear fusion devices. These new guard limiters can operate at a peak power density of 12.9 MW/m². Strong hot spots were usually observed on the old graphite limiters when 4.6 GHz system operated with power >2.0 MW [B. N. Wan et al., Nucl. Fusion 57 (2017) 102019], leading to a reduction of the maximum power capability. With the new limiters, 4.6 GHz LH system, the main current drive (CD) and electron heating tool for EAST, can be operated with power >2.5 MW routinely. Long-pulse operation up to 100 s with 4.6 GHz LH power of 2.4 MW was achieved in 2021 and the maximal temperature on the guard limiters measured by an infrared (IR) camera was about 540 ℃, much below the permissible value of tungsten material (~1200 ℃). A discharge with a duration of 1056 s was achieved and the 4.6 GHz LH energy injected into the plasma was up to 1.05 GJ. Secondly, the fully-active-multijunction (FAM) launcher of 2.45 GHz system was upgraded to a passive-active-multijunction (PAM), for which the density of optimum coupling was relatively low (below the cut-off value). Good coupling with reflection coefficient ~3% has been achieved with plasma-antenna distance up to 11 cm for the new PAM. Finally, in order to eliminate the effect of ion cyclotron range of frequencies (ICRF) wave on 4.6 GHz LH wave coupling, the location of the ICRF launcher was changed to a port that is located 157.5° toroidally from the 4.6 GHz LH system and is not magnetically connected.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.571-578
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• 2001

To evaluate if the apoptotic fragment assay could be used to estimate the dose prediction after radiation exposure, we examined apoptotic mouse crypt cells per 1,000 cells after whole body $^{60}Co$ $\gamma$-rays and 50MeV ($p{\rightarrow}Be^+$) cyclotron fast neutron irradiation in the range of 0.25 to 1 Gy, respectively. The incidence of apoptotic cell death rose steeply at very low doses up to 1 Gy, and radiation at all doses tigger rapid changes in crypt cells in stem cell region. These data suggest that apoptosis may play an important role in homeostasis of damaged radiosensitive target organ by removing damaged cells. The curve of dose-effect relationship for the data of apoptotic fragments was obtained by the linear-quadratic model $y=0.18+(9.728{\pm}0.887)D+(-4.727{\pm}1.033)D^2$ ($r^2=0.984$) after $\gamma$-rays irradiation, while $y=0.18+(5.125{\pm}0.601)D+(-2.652{\pm}0.7000)D^2$ ($r^2=0.970$) after neutrons in mice. The dose-response curves were linear-quadratic, and a significant dose-response relationship was found between the frequency of apoptotic cell and dose. These data show a trend towards increase of the numbers of apoptotic crypt cells with increasing dose. Both the time course and the radiation dose-response curve for high and low linear energy transfer (LET) radiation modalities were similar. The relative biological effectiveness (RBE) value for crypt cells was 2.072. In addition, there were significant peaks on apoptosis induction at 4 and 6h after irradiation, and the morpholoigcal findings of the irradiated groups were typical apoptotic fragments in crypt cells that were hardly observed in the control group. Thus, apoptosis in crypt cells could be a useful in vivo model for studying radio-protective drug sensitivity or screening test, microdosimetric indicator and radiation-induced target organ injury. Since the apoptotic fragment assay is simple, rapid and reproducible in the range of 0.25 to 1 Gy, it will also be a good tool for evaluating the dose response of radiation-induced organ damage in vivo and provide a potentially valuable biodosimetry for the early dose prediction after accidental exposure.

• The Korean Journal of Nuclear Medicine
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• v.18 no.2
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• pp.17-23
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• 1984

For nearly a century it has been known that chemical activity accompanies mental activity, but only recently has it been possible to begin to examine its exact nature. Positron-emitting radioactive tracers have made it possible to study the chemistry of the human mind in health and disease, using chiefly cyclotron-produced radionuclides, carbon-11, fluorine-18 and oxygen-15. It is now well established that measurable increases in regional cerebral blood flow, glucose and oxygen metabolism accompany the mental functions of perception, cognition, emotion and motion. On May 25, 1983 the first imaging of a neuroreceptor in the human brain was accomplished with carbon-11 methyl spiperone, a ligand that binds preferentially to dopamine-2 receptors, 80% of which are located in the caudate nucleus and putamen. Quantitative imaging of serotonin-2, opiate, benzodiazapine and muscarinic cholinergic receptors has subsequently been accomplished. In studies of normal men and women, it has been found that dopamine and serotonin receptor activity decreases dramatically with age, such a decrease being more pronounced in men than in women and greater in the case of dopamine receptors than serotonin-2 receptors. Preliminary studies in patients with neuropsychiatric disorders suggests that dopamine-2 receptor activity is diminished in the caudate nucleus of patients with Huntington's disease. Positron tomography permits quantitative assay of picomolar quantities of neuro-receptors within the living human brain. Studies of patients with Parkinson's disease, Alzheimer's disease, depression, anxiety, schizophrenia, acute and chronic pain states and drug addiction are now in progress. The growth of any scientific field is based on a paradigm or set of ideas that the community of scientists accepts. The unifying principle of nuclear medicine is the tracer principle applied to the study of human disease. Nineteen hundred and sixty-three was a landmark year in which technetium-99m and the Anger camera combined to move the field from its latent stage into a second stage characterized by exponential growth within the framework of the paradigm. The third stage, characterized by gradually declining growth, began in 1973. Faced with competing advances, such as computed tomography and ultrasonography, proponents and participants in the field of nuclear medicine began to search for greener pastures or to pursue narrow sub-specialties. Research became characterized by refinements of existing techniques. In 1983 nuclear medicine experienced what could be a profound change. A new paradigm was born when it was demonstrated that, despite their extremely low chemical concentrations, in the picomolar range, it was possible to image and quantify the distribution of receptors in the human body. Thus, nuclear medicine was able to move beyond physiology into biochemistry and pharmacology. Fundamental to the science of pharmacology is the concept that many drugs and endogenous substances, such as neurotransmitters, react with specific macromolecules that mediate their pharmacologic actions. Such receptors are usually identified in the study of excised tissues, cells or cell membranes, or in autoradiographic studies in animals. The first imaging and quantification of a neuroreceptor in a living human being was performed on May 25, 1983 and reported in the September 23, 1983 issue of SCIENCE. The study involved the development and use of carbon-11 N-methyl spiperone (NMSP), a drug with a high affinity for dopamine receptors. Since then, studies of dopamine and serotonin receptors have been carried out in over 100 normal persons or patients with various neuropsychiatric disorders. Exactly one year later, the first imaging of opitate receptors in a living human being was performed [1].

• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.327-336
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• 1999

Purpose: To assess the quantitative accuracy and the clinical utility of 3D volumetric PET imaging with FDG in brain studies, 24 patients with various neurological disorders were studied. Materials and Methods: Each patient was injected with 370 MBq of 2-[$^{18}F$]fluoro-2-deoxy-D-glucose. After a 30 min uptake period, the patients were imaged for 30 min in 2 dimensional acquisition (2D) and subsequently for 10 min in 3 dimensional acquisition imaging (3D) using a GE $Advance^{TM}$ PET system, The scatter corrected 3D (3D SC) and non scatter-corrected 3D images were compared with 2D images by applying ROIs on gray and white matter, lesion and contralateral normal areas. Measured and calculated attenuation correction methods for emission images were compared to get the maximum advantage of high sensitivity of 3D acquisition. Results: When normalized to the contrast of 2D images, the contrasts of gray to white matter were $0.75{\pm}0.13$ (3D) and $0.95{\pm}0.12$ (3D SC). The contrasts of normal area to lesion were $0.83{\pm}0.05$ (3D) and $0.96{\pm}0.05$ (3D SC). Three nuclear medicine physicians judged 3D SC images to be superior to the 2D with regards to resolution and noise. Regional counts of calculated attenuation correction was not significantly different to that of measured attenuation correction. Conclusion: 3D PET images with the scatter correction in FDG brain studies provide quantitatively and qualitatively similar images to 2D and can be utilized in a routine clinical setting to reduce scanning time and patient motion artifacts.

• The Korean Journal of Nuclear Medicine
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• v.36 no.1
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• pp.1-7
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• 2002

Positron Emission Tomography (PET) is a nuclear medicine imaging modality that consists of systemic administration to a subject of a radiopharmaceutical labeled with a positron-emitting radionuclide. Following administration, its distribution in the organ or structure under study can be assessed as a function of time and space by (1) defecting the annihilation radiation resulting from the interaction of the positrons with matter, and (2) reconstructing the distribution of the radioactivity from a series of that used in computed tomography (CT). The nuclides most generally exhibit chemical properties that render them particularly desirable in physiological studies. The radionuclides most widely used in PET are F-18, C-11, O-15 and N-13. Regarding to the number of the current PET Centers worldwide (based on ICP data), more than 300 PET Centers were in operation in 2000. The use of PET technology grew rapidly compared to that in 1992 and 1996, particularly in the USA, which demonstrates a three-fold rise in PET installations. In 2001, 194 PET Centers were operating in the USA. In 1994, two clinical and research-oriented PET Centers at Seoul National University Hospital and Samsung Medical Center, was established as the first dedicated PET and Cyclotron machines in Korea, followed by two more PET facilities at the Korea Cancer Center Hospital, Ajou Medical Center, Yonsei University Medical Center, National Cancer Center and established their PET Center. Catholic Medical School and Pusan National University Hospital have finalized a plan to install PET machine in 2002, which results in total of nine PET Centers in Korea. Considering annual trends of PET application in four major PET centers in Korea in Asan Medical Center recent six years (from 1995 to 2000), a total of 11,564 patients have been studied every year and the number of PET studies has shown steep growth year upon year. We had 1,020 PET patients in 1995. This number increased to 1,196, 1,756, 2,379, 3,015 and 4,414 in 1996,1997,1998,1999 and 2000, respectively. The application in cardiac disorders is minimal, and among various neuropsychiatric diseases, patients with epilepsy or dementia can benefit from PET studios. Recently, we investigated brain mapping and neuroreceptor works. PET is not a key application for evaluation of the cardiac patients in Korea because of the relatively low incidence of cardiac disease and less costly procedures such as SPECT can now be performed. The changes in the application of PET studios indicate that, initially, brain PET occupied almost 60% in 1995, followed by a gradual decrease in brain application. However, overall PET use in the diagnosis and management of patients with cancer was up to 63% in 2000. The current medicare coverage policy in the USA is very important because reimbursement policy is critical for the promotion of PET. In May 1995, the Health Care Financing Administration (HCFA) began covering the PET perfusion study using Rubidium-82, evaluation of a solitary pulmonary nodule and pathologically proven non-small cell lung cancer. As of July 1999, Medicare's coverage policy expanded to include additional indications: evaluation of recurrent colorectal cancer with a rising CEA level, staging of lymphoma and detection of recurrent or metastatic melanoma. In December of 2001, National Coverage decided to expand Medicare reimbursement for broad use in 6 cancers: lung, colorecctal, lymphoma, melanoma, head and neck, and esophageal cancers; for determining revascularization in heart diseases; and for identifying epilepsy patients. In addition, PET coverage is expected to further expand to diseases affecting women, such as breast, ovarian, uterine and vaginal cancers as well as diseases like prostate cancer and Alzheimer's disease.

• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.50-60
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• 1998

I-123 labelled fatty acids are suitable for investigation of regional myocardial metabolism, so they are on the clinical trial. However, the precise properties of these materials are not characterized yet. We have synthesized phenylpentadecanoic acid and labeled this compound with I-123. The purpose of this study was to examine the stability, biodistribution, metabolism and SPECT imaging of [I-123]15-(p-iodophenyl)pentadecanoic acid(I-123-IPPA) that we made. The stability test of I-123-IPPA in serum of rat, mouse and human showed no free I-123 after 1 hour. In biodistribution study in mice for various time intervals after injection(5, 10, 15, 30, 60 minutes), uptake in myocardium was 14.5%ID/g(5 min), and 1.9%ID/heart(5 min), while uptake in muscles was 2.6%ID/g(5 min). Myocardium to blood ratio and myocardium to lung ratio increased for 5 min after injection and then decreased rapidly. Chromatographic data of rat blood and urine showed that little PPA was found in blood and urine at 15-20 min after injection. The myocardial I-123-IPPA SPECT images of a dog with myocardial infarction showed defects similar to those of Tc-99m-MIBI and F-18-FDG. These data suggest that I-123-IPPA is quite stable in vitro and shows favorable biodistribution in mice. SPECT imaging with I-123-IPPA demonstrated infarct zone as photon defect in dog model of myocardial infarction. I-123-IPPA may be used for the evaluation of fatty acid metabolism in clinical trials in Korea.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.111-112
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• 2009

Diamond-like carbon (DLC) is a convenient term to indicate the compositions of the various forms of amorphous carbon (a-C), tetrahedral amorphous carbon (ta-C), hydrogenated amorphous carbon and tetrahedral amorphous carbon (a-C:H and ta-C:H). The a-C film with disordered graphitic ordering, such as soot, chars, glassy carbon, and evaporated a-C, is shown in the lower left hand corner. If the fraction of sp3 bonding reaches a high degree, such an a-C is denoted as tetrahedral amorphous carbon (ta-C), in order to distinguish it from sp2 a-C [2]. Two hydrocarbon polymers, that is, polyethylene (CH2)n and polyacetylene (CH)n, define the limits of the triangle in the right hand corner beyond which interconnecting C-C networks do not form, and only strait-chain molecules are formed. The DLC films, i.e. a-C, ta-C, a-C:H and ta-C:H, have some extreme properties similar to diamond, such as hardness, elastic modulus and chemical inertness. These films are great advantages for many applications. One of the most important applications of the carbon-based films is the coating for magnetic hard disk recording. The second successful application is wear protective and antireflective films for IR windows. The third application is wear protection of bearings and sliding friction parts. The fourth is precision gages for the automotive industry. Recently, exciting ongoing study [1] tries to deposit a carbon-based protective film on engine parts (e.g. engine cylinders and pistons) taking into account not only low friction and wear, but also self lubricating properties. Reduction of the oil consumption is expected. Currently, for an additional application field, the carbon-based films are extensively studied as excellent candidates for biocompatible films on biomedical implants. The carbon-based films consist of carbon, hydrogen and nitrogen, which are biologically harmless as well as the main elements of human body. Some in vitro and limited in vivo studies on the biological effects of carbon-based films have been studied [$2{\sim}5$].The carbon-based films have great potentials in many fields. However, a few technological issues for carbon-based film are still needed to be studied to improve the applicability. Aisenberg and Chabot [3] firstly prepared an amorphous carbon film on substrates remained at room temperature using a beam of carbon ions produced using argon plasma. Spencer et al. [4] had subsequently developed this field. Many deposition techniques for DLC films have been developed to increase the fraction of sp3 bonding in the films. The a-C films have been prepared by a variety of deposition methods such as ion plating, DC or RF sputtering, RF or DC plasma enhanced chemical vapor deposition (PECVD), electron cyclotron resonance chemical vapor deposition (ECR-CVD), ion implantation, ablation, pulsed laser deposition and cathodic arc deposition, from a variety of carbon target or gaseous sources materials [5]. Sputtering is the most common deposition method for a-C film. Deposited films by these plasma methods, such as plasma enhanced chemical vapor deposition (PECVD) [6], are ranged into the interior of the triangle. Application fields of DLC films investigated from papers. Many papers purposed to apply for tribology due to the carbon-based films of low friction and wear resistance. Figure 1 shows the percentage of DLC research interest for application field. The biggest portion is tribology field. It is occupied 57%. Second, biomedical field hold 14%. Nowadays, biomedical field is took notice in many countries and significantly increased the research papers. DLC films actually applied to many industries in 2005 as shown figure 2. The most applied fields are mold and machinery industries. It took over 50%. The automobile industry is more and more increase application parts. In the near future, automobile industry is expected a big market for DLC coating. Figure 1 Research interests of carbon-based filmsFigure 2 Demand ratio of DLC coating for industry in 2005. In this presentation, I will introduce a trend of carbon-based coating research and applications.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.3-12
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• 2011

Purpose: With increasing medical use of radiation and radioactive isotopes, there is a need to better manage the risk of radiation exposure. This study aims to grasp and analyze the individual radiation exposure situations of radiation-related workers in a medical facility by specific job, in order to instill awareness of radiation danger and to assist in safety and radiation exposure management for such workers. Materials and Methods: From January 1, 2010 December 31, 2010, medical practitioners working in the radiation is classified as a regular personal radiation dosimetry, and subsequently one year 540 people managed investigation department to target workers, dose sectional area, working period, identify the job function-related tasks for a deep dose, respectively, the annual average radiation dose were analyzed. Frequency analysis methods include ANOVA was performed. Results: Medical radiation workers in the department an annual radiation dose of Nuclear and 4.57 mSv a was highest, dose zone-specific distribution of nuclear medicine and in the 5.01~19.05 mSv in the high dose area distribution showed departmental radiation four of the annual radiation dose of Nuclear and 7.14 mSv showed the highest radiation dose. More work an average annual radiation dose according to the job function related to the synthesis of Cyclotron to 17.47 mSv work showed the highest radiation dose, Gamma camera Cinema Room 7.24 mSv, PET/CT Cinema Room service is 7.60 mSv, 2.04 mSv in order of intervention high, were analyzed. Working period, according to domain-specific average annual dose of radiation dose from 10 to 14 in oral and maxillofacial radiology practitioners as high as 1.01~3.00 mSv average dose showed the Department of Radiology, 1-4 years, 5-9 years, respectively, 1.01 workers~8.00 mSv in the range of the most high-dose region showed the distribution, nuclear medicine, and the 1-4 years, 5-9 years 3.01~19.05 mSv, respectively, workers of the highest dose showed the distribution of the area in the range of 10 to 14 years, Workers at 15-19 3.01~15.00 mSv, respectively in the range of the high-dose region were distributed. Conclusion: These results suggest that medical radiation workers working in Nuclear Medicine radiation safety management of the majority of the current were carried out in the effectiveness, depending on job characteristics has been found that many differences. However, this requires efforts to minimize radiation exposure, and systematic training for them and for reasonable radiation exposure management system is needed.