• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.442-448
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• 2016

This study was conducted to determine the appropriateness of systemic radiation exposure control for students in clinical practice by comparing radiation exposure in radiography employees at different stations of a hospital with that of students conducting clinical practice using identical stations. Overall, 121 students who conducted clinical practice in the department of radiology area of C university hospital from July 2014 to August 2014 and 62 workers working in the same medical facility (47 in the department of radiology, 8 in the department of radiation oncology, 7 in the department of nuclear medicine) were investigated. The radiation exposure experienced by students was measured for 8 weeks, which is the duration of the clinical practice. Additionally, radiation exposure of workers were classified into 4 groups, department of radiology, department of radiation oncology, and department of nuclear medicine was compared. Dose was measured with OSLD and differences among groups were identified by ANOVA followed by Duncan's multiple range test. Among employees, those in the department of radiology, oncology and nuclear medicine were exposed depth doses of $0.127{\pm}0.331mSv$, $0.01{\pm}0.003mSv$, and $0.431{\pm}0.205mSv$, respectively, while students were exposed to $0.143{\pm}0.136mSv$. Additionally, workers in the department of radiology, oncology and nuclear medicine were exposed to surface doses of $0.131{\pm}0.331mSv$, $0.009{\pm}0.003mSv$, and $0.445{\pm}0.198mSv$, respectively, while students were exposed to $0.151{\pm}0.14mSv$, which was significantly different in both doses (p < 0.01). The average dose that students received is higher than that of the other groups (except for nuclear medicine workers), indicating that further improvements must be made in systemic controls for individual radiation exposure by including the students as subjects of management for protection from radiation.

• Journal of radiological science and technology
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• v.37 no.2
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• pp.109-116
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• 2014

Many studies have suggested that in the era of Drug-Eluting Stents(DES) are one of the causes of In-Stent Restenosis(ISR) of Stent Fracture(SF). The present study sought to evaluate clinical characteristics of patients with stent fracture after successful DES implantation. The 4,701 patients were selected for analysis who underwent a follow-up coronary angiography irrespective of ischemic symptoms. The overall incidence of SF was 32 patients(male:female=19:13, Av. age $62.44{\pm}9.8$year, 0.68%). Fractures of Sirolimus-Eluting Stents(SES), Paclitaxel-Eluting Stents(PES), Biolimus A9-Eluting Stents(BES), Everolimus-Eluting Etents(EES), Endothelial Progenitor Cell Capture Stent(EPC) and Zotarolimus-Eluting Stents(ZES) are accounted for 19(59.4%), 9(28.1%), 2(6.3%), 1(3.1%), 1(3.1%) and 0(0%) respectively. SF developed in the left Anterior Dscending(LAD) artery in 16 patients(50%) and in complex(type B2, C) lesions in 25 patients(69.4%). Ten patients were treated with heterogenous DES, the rest being treated with either homogenous DES(3 patients), plain old balloon angioplasty(3 patients), or conservative medical treatment(17 patients). None of the patients with SF suffered from cardiac death during a follow-up period of $32.9{\pm}12.4$ months. The overall rate of DES fracture over up to 3.7 years of follow-up was 0.68% with higher incidence in SES than in PES. SF frequently occurred in the LAD artery and in complex lesions. Of the patients with SF, coronary intervention was performed only when the binary restenosis lesion was significant. During the follow-up, patients with SF have continued on combination antiplatelet therapy. There is a very low rate of major adverse cardiac events(post-detection of SF), especially cardiac death associated with SF.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.302-306
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• 2009

The principal objective of this investigation was to identify adequate species for the harvest of Perilla frutescens leaves, which provide profound antioxidant activities, and harbor abundant caffeic acid and rosmarinic acid. Namchun, Donggeul-2, Bora, Sae-bora and Neul-bora variants of the plant were assessed herein. In this study, we evaluated the antioxidant effects of these plants, and utilized an HPLC system to verify their caffeic acid and rosmarinic acid contents. Dried Perilla frutescens leaves were boiled at a temperature of $100^{\circ}C$ for three hours, and were lyopholized in a freezedryer. The extracts were then processed in order to confirm their antioxidant activities via 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity assay, ferric-reducing antioxidant power (FRAP) assay, total flavonoid content and total polyphenol content assays. According to the observed antioxidant results of the five tested species of Perilla frutescens leaves, Bora and Donggeul-2 were shown to have more potent antioxidant activities than the other tested variants. The scavenge 50% of DPPH radical ($SC_50$ of DPPH) values were 241 ${\mu}g$ DM/mL in Donggeul-2 and 261 ${\mu}g$ DM/mL in Bora. Based on the results of the FRAP assay, the Bora variant showed a value of 796 mM $FeSO_4$ $7H_2O/g$ DM, and Donggeul-2 exhibited a value of 748 mM $FeSO_4$ $7H_2O/g$ DM, of which the total polyphenol contents were measured as 69.4 g GAE/kg DM and 61.8 g GAE/kg DM, respectively. Moreover, the Bora variant had the highest level of caffeic acid, and Donggeul-2 showed the highest rosmarinic acid content among the tested samples (0.87 mg/100 g wet base and 121 mg/100 g wet base, respectively). According to the results of this experiment, we selected two species, Bora and Donggeul-2, which were both verified to contain adequate and favorable antioxidant activities.

• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.219-228
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• 2015

To secure water resources, dams are normally constructed on the upper - middle part of streams, and it generates physical disturbances such as habitat alteration and stream fragmentation. Such construction can restrict movement of aquatic organisms, especially for freshwater fish which is one of top predator in aquatic ecosystem, and cause genetic fragmentation and community change. In this study, to investigate impact of habitat alteration after dam construction on freshwater fish, we monitored fish community changes, and compared fish fauna between dam reservoir and inflows. Additionally, movement characteristics and habitat boundaries of four species were identified by radio telemetry method. The study was conducted in the Gunwi Dam which was constructed in December 2010. Radio telemetry was applied to Pungtungia herzi, Zacco platypus (living lotic and lentic), Silurus asotus (lentic preferred species) and Zacco koreanus (lotic preferred species). The number of species was remarkably decreased (4 family, 10 species) comparing with before the dam construction (7 family, 15 species). Specifically, Coreoleuciscus splendidus, Niwaella multifasciata, Liobagrus mediadiposalis, Coreoperca herzi and Odontobutis platycephala that inhabit in the lotic environment were not collected in the study area. A total of 8 species were caught in both the dam reservoir and tributaries except 2 species (C. auratus and S. asotus). Sorenson's similarity between the reservoir and its tributaries was high (0.842). All of the radio tagged species stayed in the reservoir except S. asotus which moved to the tributary. These species mainly utilized the shallow littoral zone as a habitat. These results could be useful as a baseline data for efficient management of fishes in lakes.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.158-167
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• 2016

The requirements for medical laboratories ISO 15189 is examined in organization and a quality management system, stressing the importance of evidence, document control, and control of records and clinical material. Medical services are provided from the areas of resource management, and pre-examination, examination and post-examination processes. The main goal of ISO 15189 accreditation is to improve the quality of laboratory services provided for patients and clinical users not only through compliance with consensually developed and harmonized requirements but also by adopting the philosophy of continual improvement using the Plan-Do-Check-Act cycle. Laboratory quality should be evaluated and improved in all steps of the testing process as the state-of-the art indicates that the pre- and post-analytical phases are more vulnerable to errors than the intra-analytical phase. The Korea Laboratory Accreditation Scheme (KOLAS), a national accreditation body, provides medical laboratory accreditations for appropriate approaches to evaluating the competence of a medical laboratory in providing effective services to its customers and clinical users. Adoption of ISO 15189 in 2010s as a government policy has been delayed, and only 5 laboratories have been accredited to date in Korea. The medical laboratories should seek the adoption of ISO 15189 with a positive attitude for quality improvement and strengthening of international competitiveness.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.115-123
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• 2006

Purpose : We investigated whether there had been any change in the epidemiology of Streptococcus pneumoniae in Korea before and after introduction of heptavalent pneumococcal conjugate vaccine(PCV7). Methods : Between September 2001 and August 2006, clinical isolates were collected from patients with pneumococcal infection in Severance Hospital, Seoul, Korea. We analyzed trends in serotype distribution and antibiotic resistance before and after the introduction of PCV7. Results : There were 363 strains of Streptococcus pneumoniae isolated from clinical specimens; 143 before and 220 after PCV7 introduction. The predominant serotypes, in order of decreasing frequency, were 19F, 19A, 23F, 6B, 6A, 3, 9V, 14, 11A, 4, 29, and 18C; 152 isolates(41.9%) belonged to types included in PCV7. The proportion of clinical isolates that were nonsusceptible to penicillin increased from 58.8% in 2001 to 83.6% in 2006(P=0.046). There was no significant diminution in pneumococcal infection caused by vaccine serotypes after the introduction of PCV7. In children younger than age 2 years, the proportion of clinical isolates that were vaccine serotypes was higher than in persons older than age 15 years (59.3% vs 37.8%, P=0.004). Conclusions : There was no significant diminution in pneumococcal infection caused by vaccine serotypes after the introduction of PCV7, therefore more universal pneumococcal immunization program is recommended especially for children younger than age 2 years.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.159-175
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• 2015

Surveys of weed species on upland fields were conducted in Korea to investigate the occurrence of weed flora from April to May 2014 for winter crop fields and from July to August 2014 for summer crop fields. From the nation-wide survey, 375 weed species in 50 families were identified and classified to 162 annuals, 78 biennials and 135 perennials. Based on the occurrence ratio, the most weed species belonged to Compositae (73 species). 44 and 25 weed species belonged to Poaceae and Polygonaceae, respectively, and these 183 weed species in the most five families accounted for 49% of total weed occurrence. While 287 weed species in 45 families occurred in the winter crop fields, 339 weed species in 47 families occurred in summer crop fields. The most dominant weed species in Korean upland fields were Digitaria ciliaris, followed by Portulaca oleracea, Acalypha australis, Chenopodium album, Rorippa palustris etc. 129 weed species in 25 families were considered as exotic weeds. Based on the importance analysis, the highest value was C. album followed by Amaranthus lividus, Conyza canadensis etc. This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in upland fields of Korea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.1
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• pp.33-39
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• 1999

In order to understand the importance of tidal action and $NH_4{^+}$ -nitrification in the removal of dissolved oxygen (DO) and $NH_4{^+}$, concentrations of DO, $NH_4{^+}$, $NO_2{^-}$ and $NO_3{^-}$ were measured with time for water samples collected at different tidal state in the eutrophic macrotidal Han River estuary. Field measurements indicated that most environmental parameters, except for the water temperature and DO concentration, were tightly controlled by the eutrophic freshwater runoff and large-scale tidal action. Dark incubation of the water sample at $25^{\circ}C$ showed that the removal rates of DO and $NH_4{^+}$ in high tide sample were 2.76 ${\mu}M\;O_2\;d^{-1}$ and 1.76 ${\mu}M\;N\;d^{-1}$ respectively, and increased to 5.66 ${\mu}M\;O_2\;d^{-1}$ and 3.36 ${\mu}M\;N\;d^{-1}$ respectively, in low tide sample. These changes indicated that microbial degradation and uptake of organic matter and inorganic nutrients were more active during low tide. $NH_4{^+}$-nitrification responsible for total DO removal in low tide (23.81%) and $NH_4{^+}$ turnover rates due to $NH_4{^+}$-nitrification in low tide (0.18 $d^{-1}$) were approximately 3.7 times and 3 times, respectively, higher than those in high tide. These results indicated that $NH_4{^+}$ -nitrifying bacteria introduced into the Han River estuary during low tide played a significant role in the removal of DO and $NH_4{^+}$. The decreasing removal rates in DO and $NH_4{^+}$ with the increasing tidal level seemed to be associated with the salinity impact on the halophobic freshwater $NH_4{^+}$-nitrifying bacteria. The results implied that anthropogenic $NH_4{^+}$ sources should be treated prior to the freshwater runoff into the estuary for the effective control of $NH_4{^+}$ in the Han River estuary. These results also suggest that parallel ecological studies on the chemoautotrophic nitrifying bacteria are essential for the elucidation of nitrogen cycles in the eutrophic Han River estuary.

• Korean Journal of Community Nutrition
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• v.7 no.1
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• pp.121-129
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• 2002

Osteoporosis, the typical metabolic bone disease of the elderly, is characterized by a reduction in bone mineral density (BMD) and increased fracture risk. Genetic and environmental factors are known to play a key role in bone metabolism, and diet is also considered to be one of the important factors. The purpose of the present study was to investigate the relationship among the factors affecting BMD, including stature, body weight, age, time period since onset of menopause, and biochemical markers of bone turnover in postmenopausal women. Seventy-eight postmenopausal women who visited health promotion center for health examinations volunteered to participate in this study and they were divided into two groups according to the time period since onset of menopause : women with a time period since onset of menopause of less than 5 years (Group 1) and women with a time period since onset of menopause of 5 years or more (Group 2). The demographic characteristics and dietary intake were surveyed using a questionnaire. BMDs of the lumbar spine and femoral neck of subjects were measured by dual energy X-ray absorptiometry. Serum levels of 25-hydroxy-vitamin D and parathyroid hormone (PTH), known to be indicators of bone related hormone status, were anlyzed. Serum samples were measured for calcium, phosphorus, alkaline phosphatase, and osteocalcin as bone formation indicators, and urine was analysed for deoxypyridinoline, creatinine, calcium, and sodium as bone resorption indicators. The results are as follow : The mean BMDs of the lumbar spin and femoral neck were $1.02 \pm 0.02 g/cm^2 and 0.81 \pm 0.02 g/cm^2 respectively, and the BMD level of Group 2 was significantly lower than tat of Group 1 (p<0.01, p<0.05, respectively). The mean daily intake of energy was 1838 $\pm$ 55 kcal. When nutrient intake was compared with the recommended dietary allowances (RDA) of the subjects, only calcium, vitamin A and riboflavin intake showed means lower than the RDA. The nutrient intake did not show any significant differences between Group 1 and 2 Serum and urine levels of biochemical markers of bone turnover did not show any significant differences between Group 1 and 2, and all were within the normal range. However, the PTH and deoxypyridinoline levels showed a tendency to be higher, and the osteocalcin level to be lower in Group 2 than in Group 1. Although age and years after menopause (YAM) showed negative correlations with lumbar spine bone mineral density (LBMD) (r= -0.38, p<0.001, and r= -0.26, p< 0.05, respectively), no correlation was found with femoral neck bone mineral density (NBMD). While height, body weight and body mass index (BMI) showed a positive correlation with LBMD (r= 0.32, p<0.001, r= 0.38, p<0.001, r= 0.22, p= 0.05, respectively), only body weight and BMI showed a positive correlation with NBMD (r= 0.30, p<0.01, and r= 0.27, p<0.05, respectivley). There was no significant corealtion between BMDs and the nutrient intake of subjects, except in the case of carbohydrates (r= 0.22, p<0.05). Also, serum and urine levels of bone turnover markers showed no significant correlation with nutrient intake. On the other hand, serum osteocalcin had a positive correlation with vitamin C intake (r= 0.22, p= 0.05), and urine deoxypyridinolin showed a negative correlation with niacin intake (r= -0.22, p= 0.05). Urinary na was negatively correlated with protein intake(r= -0.23, p= 0.05). The results suggested that it is difficult to prevent the decrease in bone mass among postmenopausal women eating the usual Korean diet. However, the BMDs of the lumbar spine and femoral neck were positively related to body weight ad BMI in postmenopausal women. Therefore, this study confirmed that one of the most effective ways to minimize bone loss in postmenopausal women would be to maintain an adequate body weight with balanced nutrient intake and activity in the pre-and postmenopausal periods.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.571-584
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• 2004

It is known widely that granulosa cell apoptosis leads follicular atresia and macrophages exert their effects directly and/or indirectly from the initiation to the completion of follicular atresia by phagocytosis of apoptotic bodies and secretion of various cytokines. However, the site of initiation, propagation routes and the elimination methods of apoptotic bodies, and the time and methods of penetration of macrophages into the follicles are not known completely. Using pig(Yorkshire-breed) ovary, immunohistochemical studies with TUNEL for apoptotic bodies and pig macrophage monoclonal antibody 4E9 for macrophages, and light and transmission electron microscopic observations were performed. In the pig, follicular atresia began with the granulosa cell apoptosis, and the apoptosis of theca intema cells occured at the same time. The apoptosis of granulosa cells initiated randomly within the granulosa cell layer and propagated rapidly into the whole layer. Ultrastructura1ly, apoptotic granulosa cells showed characteristic pyknotic and deformed nucleus and intracytoplasmic vesicles. Apoptotic bodies were eliminated by intact granulosa cells and macrophages. Intact granulosa cells ingested apoptotic bodies transiently, soon after they fell into the apoptosis. Finally, apoptotic bodies and degenerated oocyte were phagocytosed by macrophages. Macrophages entered the ovarian follicle at the time of initiation of granulosa cell apoptosis, and migrated with the progression of apoptosis. By elimination of theca cells, macrophages contributed the completion of follicular atresia These results will provide valuable informations on the study of the interrelation between macrophage and ovarian follicular atresia.