• The Korean Journal of Nuclear Medicine
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• v.39 no.3
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• pp.200-208
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• 2005

Purpose: Tc-99m labeled diethylenetriaminepentaacctic acid (DTPA)-coupled galactosylated human serum albumin (GSA) is a currently used imaging agent for asialoglycoprotein receptor (ASGPR) of the liver, but, it has several shortcomings. Recently a new ASGPR imaging agent, $^{99m}Tc$-lactosylated human serum albumin (LSA), with simple labeling procedure, high labeling efficiency, high stability was developed. In order to assess the feasibility of the $^{99m}Tc$-LSA as a ASGPR imaging radiopharmaceuticals, we performed biodistribution study of the tracer in liver injured mice model and the results were compared with histolgic data. Materals and Methods: To induce hepatic damage in ICR mice, diethylnitrosamine (DEN) ($60mg/kg/week{\times}5time$, low dose or $180mg/kg/week{\times}2times$, high dose) and thioacetamide (TAA) ($50mg/kg{\times}1time$) were administrated intraperitoneally. Degree of liver damage was evaluated by tissue hematoxilin-eosin stain, and expression of asialoglycoprotein receptor (ASGPR) was assessed by immunohistochemistry using ASGPR antibody. $^{99m}Tc$-LSA was intravenously administrated via tail vein in DEN or TAA treated mice, and biodistribution study of the tracer was also performed. Results: DEN treated mice showed ballooning of hepatocyte and inflammatory cell infiltration in low dose group and severe hapatocyte necrosis in high dose group, and low dose group showed higher ASGPR staining than control mice in immunohistochemical staining. TAA treated mice showed severe hepatic necrosis. $^{99m}Tc$-LSA Biodistribution study showed that mice with hepatic necrosis induced by high dose DEN or TAA revealed higher blood activity and lower liver activity than control mice, due to slow clearance of the tracer by the liver. The degree of liver uptake was inversely correlated with the degree of histologic liver damage. But low dose DEN treated mice with mild hepatic injury showed normal blood clearance and hepatic activity, partly due to overexpression of ASGPR in mice with mild degree hepatic injury. Conclusion: Liver uptake of $^{99m}Tc$-LSA was inversely correlated with degree of histologic hepatic injury in DEN and TAA treated mice. These results support that $^{99m}Tc$-LSA can be used to evaluate the liver status in liver disease patients.

• The Korean Journal of Nuclear Medicine
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• v.36 no.4
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• pp.261-270
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• 2002

Purpose: Nicotinic acetylcholine receptors (nAChRs), which mediate excitatory neurotransmission, are known to participate in various neurophysiological functions. Severe losses of nAChRs have been noted in Alzheimer's and Parkinson's diseases. Therefore, noninvasive and quantitative imaging of nAChRs would offer a better understanding on the function of these receptors. In this study, $2-[^{18}F]fluoro-A85380\;([^{18}F]1)$, an ${\alpha}_4{\beta}_2$ nAChRs radioligand, was prepared using one HPLC purification and evaluated in mouse brain, and the results were compared with those in the literature. Materials and Methods: $[^{18}F]1$ was prepared by $[^{18}F]$fluorination of the iodo precursor followed by acidic deprotection and then purified by HPLC. Tissue distribution studies were performed in mouse brain at the indicated time points and the result was expressed as %ID/g. Inhibition studies were also carried out with pretreatment of various ligands. Results: One HPLC purification method gave the desired product in 15-20% radiochemical yield and with high specific activity ($38-55GBq/{\mu}mol$). Tissue distribution studies showed that $[^{18}F]1$ specifically labeled nAChRs in mouse brain with a high thalamus to cerebellum uptake ratio (13.8 at 90 min). Inhibition studios demonstrated selective binding of $[^{18}F]1$ to nAChRs, blocking the uptake of the $[^{18}F]1$ in nAChR-rich legions by selective ligands such as cytisine and nicotine which are well-known nAChRs agonists. Conclusion: This study demonstrated that the $[^{18}F]1$ produced by the method using one HPLC purification gave the results similar to those reported in the literature. Therefore, this synthetic method can be readily applied to the routine preparation of $[^{18}F]1$, a PET radioligand for ${\alpha}_4{\beta}_2$ nAChRs imaging.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.57-61
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• 2015

Purpose We considered the correlation of Ejection Fraction (EF) which was analyzed by Multi Gated Blood Pool Scan (MUGA) and Echocardiography (ECHO) for the patients who were classified according to the condition of cardiac function. Materials and Methods We analyzed the patients (female 60) who were diagnosed with breast cancer and were examined by both MUGA and ECHO. The 30 patients (age: $58.27{\pm}13.48$) who were analyzed into less than 50% to 70% of EF were categorized as normal group and the other 30 patients (age: $53.70{\pm}8.45$) who were analyzed into less than 50% of EF were categorized as abnormal group. Statistical analysis with SPSS ver. 18 was applied. Results Each of the value of mean and standard deviation of normal group was $66.43{\pm}5.80$ (MUGA), $60.50{\pm}4.93$ (ECHO). There was a significant difference (p<0.001). Each of the value of mean and standard deviation of abnormal group was $41.93{\pm}7.58$ (MUGA), $41.70{\pm}11.49$ (ECHO). There was no significant difference (p>0.001). In the result, all 30 cases of normal group showed the same reading. 8 out of 30 cases in abnormal group showed inconsistency of the reading. Conclusion We could confirm the correlation of the EF in MUGA and ECHO statistically. There was difference between abnormal groups from the result of reading. If we are aware of the result according to the different cardiac function categorization, MUGA and ECHO can be used as even more accurate interchangeable test.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.19 no.1
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• pp.25-32
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• 1983

The corner reflector is used to increase the echoing area of radar targets in the air, and it can also be applied to increase the echoing area of the sonar targets under water. As the basic research for this application, the authors investigated the ultrasonic reflection characteristics under water for the corner reflector which was made of aluminum plate. The experiments were made by pulse measuring method with the magnetostrictive ferrite transducers of 28, 50 and 75KHz in the experimental water tank. The results obtained are as follows; 1. The target strength of corner reflectors were increased in proportion to the diameter and were greater at higher frequency of 75KHz than at lower frequency of 28KHz. 2. In the case of 5 corner reflectors of 150mm in diameter which have corner angles of 15$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$, 60$^{\circ}$ and 90$^{\circ}$the measured values of the maximum target strength at 75KHz were-25.0 dB, -17.2dB, -15.1dB, -13.4dB and 11.0dB, and then the number of main lobes showing the maximum target strength in the backscattering patterns were 24, 12, 8, 6 and 4, respectively. 3. When 7 corner reflector of 80mm in diameter and 90$^{\circ}$ in the corner angle was located on the minor axis of the horizontal section with directional angles of 0$^{\circ}$, 2.5$^{\circ}$, 5.0$^{\circ}$, 7.5$^{\circ}$, 10$^{\circ}$ and 12.5$^{\circ}$ against the sound beam axis, the measured values of the target strength on each position at 75KHz were -21.2dB, -21.9dB, -26.0dB, -30.5dB and -36.8dB, respectively.

• Journal of Life Science
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• v.7 no.4
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• pp.392-401
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• 1997

The poliovirus is a small, and non-enveloped virus. The RNA genome of poliovirus is continuous, linear, and has a single open reading frame. This polyprotein precursor is cleaved proteolytically to yield mature products. Most of the cleavages occur by viral protease. The mature proteins derived from the P1 polyprotein precursor are the structural components of the viral capsid. The initial cleavage by 2A protease is indirectly involved in the cleavage of a cellular protein p220, a subunit of the eukaryotic translation initiation factor 4F. This cleavage leads to the shut-off of cap-dependent host cell translation, and allows poliovirus to utilize the host cell machinery exclusively for translation its own RNA, which is initiated by internal ribosome entry via a cap-independent mechanism. The functional role of the 2B, 2C and 2BC proteins are not much known. 2B, 2C, 2BC and 3CD proteins are involved in the replication complex of virus induced vesicles. All newly synthesized viral RNAs are linked with VPg. VPg is a 22 amino acid polypeptide which is derived from 3AB. The 3C and 3CD are protease and process most of the cleavage sites of the polyprotein precursor. The 3C protein is also involved in inhibition of RNA polymerase II and III mediated transcription by converting host transcription factor to an inactive form. The 3D is the RNA dependent RNA polymerase. It is known that poliovirus replication follows the general pattern of positive strand RNA virus. Plus strand RNA is transcribed into complementary minus strand RNA that, in turn, is transcribed for the synthesis of plus strand RNA is transcribed into complementary minus strand RNA that, in turn, is transcribed for the synthesis of plus strand RNA strands. Poliovirus RNA synthesis occurs in a membranous environment but how the template RNA and proteins required for RNA replication assemble in the membrane is not much known. The RNA requirements for the encapsidation of the poliovirus genome (packaging signal) are totally unknown. The poliovirus infection cycle lasts approximately 6 hours.

• Journal of Nutrition and Health
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• v.44 no.1
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• pp.29-40
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• 2011

The purpose of this study was to examine the association among bone mineral density (BMD), biochemical bone markers, nutrients, and salt intake in premenopausal and postmenopausal women. We evaluated 431 subjects who visited a health promotion center of a university hospital between January 2008 and July 2009. We excluded those who were taking medications or who had an endocrine disorder affecting osteoporosis. The subjects were divided into premenopausal (n = 283) and postmenopausal (n = 143) women. We evaluated the correlation among BMD of the lumbar spine, femoral neck, and total femoral, as well as biochemical bone markers, hormone, serum profiles, general characteristics, nutrient intakes, and food intake frequencies. From a stepwise multiple regression analysis, lumbar spine BMD was positively correlated with weight (p < 0.001) and negatively correlated with osteocalcin (OC)(p < 0.001), Femoral neck BMD was positively correlated with weight (p < 0.001) and negatively correlated with C-telopeptide (CTx) and alkaline phosphatase (ALP)(p < 0.001, p < 0.05). In premenopausal women, femoral total BMD was positively correlated with BMI (p < 0.001) and negatively correlated with CTx (p < 0.001). In postmenopausal women, lumbar spine BMD was positively correlated with calcium intake (p < 0.01) and negatively correlated with sodium intake (p < 0.01). Femoral neck and femoral total BMD were both positively correlated with weight (p < 0.001), and femoral neck BMD was negatively correlated with age and ALP (p < 0.001, p < 0.05). Femoral total BMD was negatively correlated with age and OC (p < 0.001, p < 0.01). These results suggest that reducing sodium intake may play an important role delaying bone resorption and preventing a decrease in BMD.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.155-160
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• 2001

Changes in genetic diversity after seed-tree practice were simulated in test plantation of tulip tree at Sokdal-ri, Banwol-myon, Hwasung-gun, Kyungki Provence. I-SSR markers were analyzed in a total of 305 tulip trees. A total of 89 amplicon variants were observed by PCR with 9 I-SSR primers. Genetic diversity for 305 trees was relatively high (S. I. =0.4532). Individuals originated from the seed orchards in U.S.A. showed the highest level of genetic diversity (0.4530), those from Anyang showed the medium level (0.4152), and those from Cheonbuk showed the lowest (0.3929). Simulation of seed-tree practice accompanied by 2 consecutive thinnings was performed on the basis of morphological characteristics and planted distances of the individual trees, which left 37 trees as candidates for seed-trees. Decreasing rate of genetic diversity within seed sources was greatest for individuals from Cheonbuk (28.3%), moderate for those from Anyang (16.3%), and smallest for those from U.S.A. (8.0%). In spite of little difference in decreasing rate of individuals for the 3 seed sources (87.5~88.2%), large difference in decreasing rate of genetic diversity within seed sources might be due to difference in number of mother trees for the 3 seed sources. For example, whereas individuals originated from the seed orchard in U.S.A., which showed the smallest decreasing rate of genetic diversity, might be originated from relatively large number of mother trees, those from Anyang and Cheonbuk might be originated from relatively small number of mother trees. Although mean of 17.5% of the genetic diversity within seed sources was decreased through 2 consecutive thinnings, a decrease in genetic diversity for the whole individuals (37 trees) was only 6.1%. This observation suggests that the seed-tree practice on the basis of the criteria established in the present study may not result in great reduction in overall genetic diversity of the progenies.

• Journal of agriculture & life science
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• v.45 no.2
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• pp.69-83
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• 2011

The aim of the research was to provide basic information for a suitable management and utilization of protected trees by law. To achieve this aim, this study investigated the current state, management status and utilization of protected trees by law in Gyeongsan city. The result of the current state of protected trees indicated that there were 55 protected trees designated since 1982. These trees consisted of 8 species which were located at 41 places. Major species was Sophora japonica (30.9%), followed by Zelkova serrata (23.6%). The protected trees have been used as sacred trees (45.5%) in the villages, followed by scenic trees (36.7%). 38.2% of the protected trees were 200 to 300 years old and 54.6% of the trees were 15 to 30 m in height. 34% of the protected trees were located in the villages, followed by beside road (19.5%). Single trees (78%) were mostly planted. The result of the management status indicated that 58.5% of the root area in protected trees were covered with bare ground, followed by gravel mulch (19.5%). The average of soil hardness was 9.64 mm. The safety fence of tree was installed at 9 places (22%) and a stone wall was built at 22 places (53.7%). 70.9% of the protected trees had a surgical operation to prevent cavities and to cure decay. Granite stone signs were installed at 33 places. The result of the utilization of protected trees indicated that 13 places were used as a rest area in the villages. It consisted of shelters, benches, athletic facilities and outdoor tables. The research suggested potential places for a mini park(pocket park) to recover a local community by using surrounding available land and improving current rest areas of protected trees. The research presented here is a first step towards a more comprehensive analysis of protected trees in Gyeongsan and further research is needed.

• Korean Journal of Breeding Science
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• v.43 no.1
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• pp.42-49
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• 2011

QTL analysis for blast resistance was carried out using 140 $BC_3F_3$ lines derived from a cross between Ilpum as a recurrent parent and Moroberekan as a donor parent. 140 $BC_3F_3$ lines with the parents were inoculated with nine blast isolates. To identify QTLs for resistance to nine blast isolates, 134 SSR markers showing polymorphisms between the parents were genotyped for the 140 $BC_3F_3$ lines. A total of 17 resistance QTLs to nine isolates were detected on chromosomes 2, 3, 4, 6, 7, 9 and 10. The phenotypic variance explained by each QTL ranged from 8.2% to 26.4%. The Moroberekan alleles contributed the positive effect at these 17 QTL loci. In a previous study, the QTL, Pi45(t) for durable resistance to blast was identified using a sequential planting method. To know the relationship between Pi45(t) and the isolate-specific resistance gene, an $F_2$ population was developed from a cross between Ilpum and an introgression line harboring Pi45(t). $F_3$ lines segregating for the Pi45(t) were inoculated to three isolates. $F_3$ lines from the $F_2$ plants with the Moroberekan segment at the target region showed resistance to two isolates. This result seems to indicate that the Pi45(t) and the isolate-specific resistance gene are tightly linked or the resistance is controlled by the same gene(s). The markers linked to genes controlling blast resistance would be useful in developing blast resistance lines in the breeding program.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.2
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• pp.184-190
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• 2016

Objectives : This study analyzed the differences of body mass index(BMI) in Korean patients with Alzheimer's diseases(AD), Mild Cognitive Impairment(MCI), and healthy controls to verify whether low BMI is associated with cognitive impairment. Furthermore, this study also sought to examine any association between BMI and Mini Mental State Examination-Korean version(MMSE-K), Clinical Dementia Rating(CDR), and Global Deterioration Scale(GDS). Methods : A total of 257 subjects were included in the study. History taking, mental status examination, physical examination and neurocognitive function test were carried out for the diagnosis of AD and MCI. The subjects' demographic data and presence of diseases were also surveyed. The overall cognitive function and severity of diseases were assessed using MMSE-K, GDS, and CDR. Results : The order of BMI was found to be healthy controls>MCI>AD, with statistically significant differences among the groups. The order of MMSE-K scores was similar, with healthy controls>MCI>AD in statistically significant differences. The healthy controls had the lowest CDR and GDS scores, and AD patients had the highest scores. There was a significant positive correlation between BMI and MMSE scores(r=0.238, p=0.000). BMI was negatively correlated with CDR(r=-0.174, p=0.008) as well as with GDS(r=-0.233, p= 0.000). Conclusions : Measuring BMI of patients with AD or MCI is expected to be meaningful in that BMI could be a clinical indicator of AD. We expect this to be beneficial for the diagnosis, prevention, and therapeutic approach of AD and also expect large-scale, long-term longitudinal studies to follow.