• The Korean Journal of Zoology
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• v.18 no.4
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• pp.163-172
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• 1975

This work was undertaken to elucidate some aspects of mechanisms underlying the increased deoxycytidineuria following irradiation in the mice, by observing Dische-positive substances liberated from thissues, the activity of CdR-aminohydrolase of tissues and the CdR excreted in the urine at various times after single whole-body exposure to 400 and 800 R of X-rays. The activity of CdR-aminohydrolase declined markedly at 1 hour in the small intestine and liver, followed by a gradual rise reaching a maximum at 3 days after irradiation. In the case of the spleen and blood, however, only a trace of activity was observed in the control and irradiated animals. The amount of Dische-positive substance liberated from the small intestine postirradiation was elevated from 3 to 12 hours, showing a maximum during 6 to 9 hours after irradiation. On the contrary, the activity of the enzyme in the liver, spleen and kidney was less than one twentieth that of the small intestine, suggesting a prediction that these organs are not attributable to the increased deoxycytidineuria. A maximum deoxycytidineuria was exhibited at 9-12 hours period, attributed a large amount of CdR to the small intestine, which might correlate with the change in the CdR-aminohydrolase activity. Radiation-induced CdR seems to be liberated from the small intestine into the blood when the CdR-aminohydrolase activity declines abruptly. Then, the CdR is rapidly subjected to a filtration in the kidney without undergoing a further degradation pathway in the blood.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.2
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• pp.141-148
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• 2013

The harmful effects of ultraviolet (UV) radiation by increasing sun exposure are making people use sunscreens casually. To keep pace with this trend, many researches about mixing different ingredients or extracting effective ingredients from natural materials are conducted by cosmetics industry. In the present study, we evaluated the UV blocking effect of the sunscreen containing Scutellaria baicalensis Georgi extract. 10 volunteers were measured by minimal erythema dose (MED) and sun protection factor (SPF) of each product. The SPF results were $34.52{\pm}2.13$ and $32.67{\pm}1.44$ in the sunscreen containing Scutellaria baicalensis Georgi extract and that of not containing the substance, respectively. Although the difference of SPF between two products was statistically not significant, it is thought to be meaningful in evaluating clinical effects of the sunscreen using natural substance to humans without any adverse reaction.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.1
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• pp.10-18
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• 2017

Korean Red Pine (Pinus densiflora) has been protected and used as the most ecologically and socio-culturally important tree species in Korea. However, as dieback of Korean red pines has occurred in the protected area of the forest genetic resources. The aims of this study is to identify causes for dieback of pine tree by investigating topographical characteristics of pine tree dieback and its correlation to meteorological factors. We extracted the dead trees from the time series aerial images and analyzed geomorphological characteristics of dead tree concentration area. As a result, 1,956 dead pine trees were extracted in the study region of 2,600 ha. Dieback of pine trees was found mostly in the areas with high altitude, high solar radiation, low topographic wetness index, south and south-west slopes, ridgelines, and high wind exposure compared to other living pine forest area. These areas are classified as high temperature and high drought stress regions due to micro-climatic characteristics affected by topographic factors. As high temperature and drought stress are generally increasing with climate change, we can evaluated that a risk of pine tree dieback is also increasing. Based on these geomorphological characteristics, we developed a pine tree dieback risk map using Maximum Entropy Model (MaxEnt), and it can be useful for establishing Korean red pine protection and management strategies.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.3
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• pp.100-110
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• 2009

'Hongro' is one of the important mid-season apple cultivars bred in Korea. The recent occurrence of water core in Hongro and the consequent problems motivated this study. The objectives of our study were to investigate the influence of air temperature during the growing period on water core occurrence in Hongro and to provide methods to mitigate its impact. Based on our field experiments for three years, the results indicated that the occurrence of water core disorder was due to the prolonged exposure to high temperature ($T_a$) of >$30^{\circ}C$ during the ripening period. The rates of occurrence of water core disorder were higher in the fruit whose weight was more than 300g or those located outside the tree canopy and thus exposed to stronger solar radiation. In terms of mitigating the water core occurrence, the application of spraying $CaCl_2$ four times from late July to August was effective. Furthermore, between 1 and 15 August when the rate of occurrence was high with $T_a$ (from 3:00 to 5:00 p.m.) >$30^{\circ}C$, the micro-water sprinkling for 30 minutes starting at 6:00 p.m. with a supplementary spray conducted two hours after the first application drastically reduced the water core occurrence.

• Journal of Life Science
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• v.29 no.11
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• pp.1200-1207
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• 2019

Ultraviolet radiation exposure is a major cause of extrinsic skin aging, which leads to skin hyperpigmentation. Loganin, a major iridoid glycoside obtained from Corni fructus, has anti-inflammatory, anti-diabetic, and neuroprotective effects. In this study, we investigated the mechanisms underlying the anti-melanogenic effects of loganin in B16F10 melanocytes treated with ${\alpha}$-melanocyte stimulating hormone (${\alpha}-MSH$) and 3-isobutyl-1-methylxanthine (IBMX). Anti-melanogenic activity was measured by treating cells with loganin at concentrations between 1 and $20{\mu}m$. Cell viability assays confirmed that doses of loganin up to $20{\mu}m$ were not cytotoxic. Loganin significantly and dose-dependently decreased intracellular melanin production. We also investigated potential molecular signaling pathways for the anti-melanogenesis effects of loganin. Western blotting showed that treatment with ${\alpha}-MSH$ and IBMX increased the phosphorylation of cAMP response element-binding protein (CREB) and the gene expressions of microphthalmia-associated transcription factor (MITF) and tyrosinase. Addition of loganin suppressed these increases, while promoting the phosphorylation of extracellular signal regulated kinase (ERK) and the anti-melanogenesis response. Our data therefore indicated that loganin could attenuate the increased melanin synthesis induced by ${\alpha}-MSH$ and IBMX treatment of B16F10 melanocytes. This attenuation appears to occur by downregulation of CREB phosphorylation and MITF and tyrosinase gene expression and upregulation of ERK phosphorylation. These finding suggests that loganin could be a valuable candidate for treatment of skin diseases related to hyperpigmentation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.618-629
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• 2021

The Fukushima nuclear power plant (NPP) accident caused by the East Japan Earthquake in 2011 and the recent increase in the frequency of earthquakes in Korea have caused safety concerns regarding radionuclide exposure. In addition, the Tokyo Electric Power Company (TEPCO) in Japan recently decided to release radionuclide-contaminated water from Fukushima's NPP into the Pacific Ocean, raising public concerns that the possibility of radionuclide contamination through both domestic- and foreign fishery products is increasing. Although many studies have been conducted on the input of artificial radionuclides into the Pacific after the Fukushima NPP accident, studies on the distribution and accumulation of artificial radionuclides in marine products from East Asia are lacking. Therefore, in this study, we attempted to explore recent research on the distribution of artificial radionuclides (e.g., ¹³⁷Cs, ^239+240Pu, ⁹⁰Sr, and etc.) in marine products from Korean seas after the Fukushima NPP accident. In addition, we also discuss future research directions as it is necessary to prepare for likely radiation accidents in the future around Korea associated with the new nuclear facilities planned by 2030 in China and owing to the discharge of radionuclide-contaminated water from the Fukushima NPP.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.1041-1047
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• 2021

In this study, the effective dose for frequently general radiography among the diagnostic reference level (DRL) for examinations provided by the government in Korea was evaluated using the Monte Carlo N-Particle eXtended (MCNPX) simulation tool. We were selected to evaluate for a total of 5 examination sites which included head anterior-posterior, chest (posterior-anterior, lateral), abdomen anterior-posterior and pelvis anterior-posterior. Physical conditions such as tube voltage and tube current used in MCNPX simulation were used in domestic conditions of the Korea Disease Control and Prevention Agency (KDCA). To evaluate domestic medical radiation exposure, we used the HDRK-Man computerized human phantom manufactured based on the international standard ICRP 103 that was applied to the MCNPX simulation. The phantom could represent the standard body shape of Koreans. As a results, the effective dose corresponding to the DRL based on adult males of head anterior-posterior position was 0.086 mSv, chest posterior-anterior position was 0.05 mSv, chest lateral was 0.354 mSv, abdomen anterior-posterior position was 0.548 mSv, and pelvis anterior-posterior position was 0.451 mSv.

• Tuberculosis and Respiratory Diseases
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• v.84 no.4
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• pp.282-290
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• 2021

Background: Radial probe endobronchial ultrasound-guided transbronchial lung biopsy (RP-EBUS-TBLB) has improved the diagnostic yield of bronchoscopic biopsy of peripheral pulmonary lesions (PPLs). The diagnostic yield and complications of RP-EBUS-TBLB for PPLs vary depending on the technique, such as using a guide sheath (GS) or fluoroscopy. In this study, we investigated the utility of RP-EBUS-TBLB using a GS without fluoroscopy for diagnosing PPLs. Methods: We retrospectively reviewed data from 607 patients who underwent RP-EBUS of PPLs from January 2019 to July 2020. TBLB was performed using RP-EBUS with a GS without fluoroscopy. The diagnostic yield and complications were assessed. Multivariable logistic regression analyses were used to identify factors affecting the diagnostic yields. Results: The overall diagnostic accuracy was 76.1% (462/607). In multivariable analyses, the size of the lesion (≥20 mm; odds ratio [OR], 2.06; 95% confidence interval [CI], 1.27-3.33; p=0.003), positive bronchus sign in chest computed tomography (OR, 2.30; 95% CI, 1.40-3.78; p=0.001), a solid lesion (OR, 2.40; 95% CI, 1.31-4.41; p=0.005), and an EBUS image with the probe within the lesion (OR, 6.98; 95% CI, 4.38-11.12; p<0.001) were associated with diagnostic success. Pneumothorax occurred in 2.0% (12/607) of cases and chest tube insertion was required in 0.5% (3/607) of patients. Conclusion: RP-EBUS-TBLB using a GS without fluoroscopy is a highly accurate diagnostic method in diagnosing PPLs that does not involve radiation exposure and has acceptable complication rates.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.165-171
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• 2021

To prevent the secondary hospital-acquired infection (cross-infection) from occurring in the general radiographic room in the department of radiology, the microbial measurement was conducted at the points making direct close contact with radiologists and patients. For the case of radiologists, the microbial measurement and incubation were focused on the x-ray tube handle of the radiation generating device, and, for the case of patients, the microbial measurement and incubation were focused on the chin supporting device, chest-contact point, and handle. Once disinfected with Aniosurf, the sterilized media were gathered and identified, and the microorganisms were confirmed. Based on the identification results, it was confirmed that the points making direct close contact with radiologists showed a value of 103 CFU for Proteus mirabilis, Staphylococcus epidermidis, Bacillus spp. and Candida spp., and that the points making direct close contact with patients showed a value of 103~5 CFU for Proteus mirabilis, Enterococcu faecium, Pseudomonas aeruginosa, NTM(Non-Tuberculosis Mycobacteria) and Candida spp.. It was also confirmed that the types and number of microorganisms gathered from the points making direct close contact with patients were greater. Fortunately, most of the involved microorganisms were observed to be on the skin surface and are known to become extinct when disinfected in accordance with the hospital-acquired infection control rules. However, since even minor exposure to such microorganisms may be lethal for patients with reduced immunity, caution must be taken. In particular, since the points making contact with patients showed a high level of microbial measurement, it was thought that it would be necessary for radiologists and personnel having frequent access to strictly disinfect the parts, such as instruments and handles, making frequent contact with patients. The purpose of this study was to announce the importance of safe microbial control in the radiographic inspection room in hospital, and this study is expected to be used as the baseline data for preventing hospital-acquired secondary infection and Nth infectious diseases.

• Journal of Korean Society of Spine Surgery
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• v.25 no.4
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• pp.185-195
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• 2018

Study Design: Literature review. Objective: Ultrasound-guided injections are a common clinical treatment for lower lumbosacral pain that are usually performed before surgical treatment if conservative treatment fails. The aim of this article was to review ultrasound-guided injections in the lumbar and sacral spine. Summary of Literature Review: Ultrasound-guided injections, unlike conventional interventions using computed tomography or C-arm fluoroscopy, can be performed under simultaneous observation of muscles, ligaments, vessels, and nerves. Additionally, they have no radiation exposure and do not require a large space for the installation of equipment, so they are increasingly selected as an alternative method. Materials and Methods: We searched for and reviewed studies related to the use of ultrasound-guided injections in the lumbar and sacral spine. Results: In order to perform accurate ultrasound-guided injections, it is necessary to understand the patient's posture during the intervention, the relevant anatomy, and normal and abnormal ultrasonographic findings. Facet joint intra-articular injections, medial branch block, epidural block, selective nerve root block, and sacroiliac joint injections can be effectively performed under ultrasound guidance. Conclusions: Ultrasound-guided injections in the lumbar and sacral spine are an efficient method for treating lumbosacral pain.