• Imaging Science in Dentistry
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• 제48권2호
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• pp.103-109
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• 2018

Purpose: To analyze cone-beam computed tomography (CBCT) use, indications, and exposure parameters in San $Jos{\acute{e}}$, Costa Rica. Materials and Methods: A cross-sectional study was performed. All CBCT examinations over a period of 6 months at 2 radiological centers in San $Jos{\acute{e}}$, Costa Rica were evaluated. The examinations were performed with Veraview EPOC X550 and Veraviewepocs 3D R100 equipment. The patients' age and sex, clinical indication for CBCT, region of interest (ROI), repeat examinations, specialty of the referring dentist, field-of-view (FOV), tube voltage (kV), tube current (mA), and radiation dose (${\mu}Gy$) were evaluated. Patients were classified by age as children (${\leq}12years$), adolescents(13-18 years), and adults(${\geq}19years$). Results: The mean age of the 526 patients was 49.4 years. The main indications were implant dentistry and dental trauma. The most frequent ROIs were posterior, while anterior ROIs were much less common. The highest percentage of repeat examinations was in children. Fifty-six percent of the referring dentists were specialists. The most commonly used FOV was small. The mean tube voltage and current were 79.8 kV and 7.4 mA for Veraview EPOC X550 and 89.9 kV and 6 mA for Veraviewepocs 3D R100, respectively. The mean doses for children, adolescents, and adults were $6.9{\mu}Gy$, $8.4{\mu}Gy$, and $7.8{\mu}Gy$, respectively. Conclusion: Although CBCT was most commonly used in adults for implant dentistry, most repeat examinations were in children, and the highest mean dose was in adolescents. Additional dose optimization efforts should be made by introducing low-dose protocols for children and adolescents.

• Journal of Radiation Protection and Research
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• 제41권4호
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• pp.368-372
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• 2016

Background: Methodologies for a series of radiological consequence assessments show a distinctive difference according to the design principles of the original nuclear suppliers and their technical standards to be imposed. This is due to the uncertainties of the accidental source term, radionuclide behavior in the environment, and subsequent radiological dose. Both types of PWR and PHWR are operated in Korea. However, technical standards for evaluating atmospheric dispersion have been enacted based on the U.S. NRC's positions regardless of the reactor types. For this reason, it might cause a controversy between the licensor and licensee of a nuclear power plant. Materials and Methods: It was modelled under the framework of the NRC Regulatory Guide 1.145 for light-water reactors, reflecting the features of heavy-water reactors as specified in the Canadian National Standard and the modelling features in MACCS2, such as atmospheric diffusion coefficient, ground deposition, surface roughness, radioactive plume depletion, and exposure from ground deposition. Results and Discussion: An integrated accident consequence assessment code, ACCESS (Accident Consequence Assessment Code for Evaluating Site Suitability), was developed by taking into account the unique regulatory positions for reactor types under the framework of the current Korean technical standards. Field tracer experiments and hand calculations have been carried out for validation and verification of the models. Conclusion: The modelling approaches of ACCESS and its features are introduced, and its applicative results for a hypothetical accidental scenario are comprehensively discussed. In an applicative study, the predicted results by the light-water reactor assessment model were higher than those by other models in terms of total doses.

• 한국양식학회지
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• 제22권1호
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• pp.63-67
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• 2009

In order to establish optimum anesthesia concentration, we tested the efficacy of clove oil at five different concentrations in large sized (mean SL $17.1{\pm}2.21\;cm$) and small sized (mean SL $0.6{\pm}0.06\;cm$) dark-banded rockfish Sebastes inermis. Optimal anesthesia concentration for dark-banded rockfish was $150\;mgL^{-1}$ in both large and small sized fish. In general, fish exposed to higher anesthetic doses were rapidly induced but took longer to recover (P<0.05). Recovery time of small sized fish was longer than large sized fish in lower concentrations, while recovery time of large sized fish was longer than small sized fish in higher concentration (P<0.05). Using the established optimum aesthetic concentration, we evaluated the physiological response of dark-banded rockfish to clove oil by measuring plasma cortisol and glucose levels. Following administration of $150\;mgL^{-1}$ clove oil at $20^{\circ}C$ (optimum breeding temperature), plasma cortisol level was highest ($42.2{\pm}11.318{\mu}g/dL$) after 0 hour, while plasma glucose level was highest ($52.5{\pm}10.61\;mg/dL$) after 1 hour. Plasma cortisol and glucose concentrations required 6 and 2 hours, respectively, to return to pre-exposure levels.

• Journal of Ginseng Research
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• 제27권4호
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• pp.171-177
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• 2003

Previously we have reported that administration of Korean red ginseng water extract (KRG-WE) plays both preventive and therapeutic roles in testicular toxicity of guinea pigs exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Further study was carried out to verify the beneficial role of Korean red ginseng in TCDD-induced testicular toxicity with different animal species by different route of administration. Korean red ginseng crude saponin (KRG-CS) was prepared by Diaion HP-20 adsorption chromatography. One hundred twenty rats (Sprauge Dawley, 200${\pm}$10 g) were divided into 6 groups. The normal control group (NC) received vehicle (i.p.) and saline (p.o.). Predetermined dosage of TCDD (40 $\mu\textrm{g}$/kg b.w., i.p.) was administered to single TCDD-treated (TT) and test (CS) groups. KRG-CS was admin-istered (p.o.) at daily doses of 5 (CS5), 10 (CS10),20 (CS2O) and/or 40 mg/kg b.w. (CS40) for 5 weeks, starting 1 week before the TCDD-exposure. Body weight gain, organ weights, and sperm quality were investigated. Decrease in body weight gain induced by TCDD was greatly attenuated by KRG-CS in a dose-dependent manner. Testicular weight, sperm head counts and ratio of sperm with progressive movement in TT group decreased significantly but those parameters were improved by the treatment of KRG-CS in a dose-dependent manner. This result led us to conclude that crude saponin might be the active ingredient of Korean red ginseng that attenuates the testicular toxicity induced by TCDD.

• 치과방사선
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• 제9권1호
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• pp.25-31
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• 1979

The utilization of x-ray for diagnosis and examination is increasing by about 5-15% every year, therefore, it would be mandatory to protect the patients from exposures and so, studies in this field are performed even now. In dental field, the area of irradiation is limited any to the head and neck area, but the irradiated angle is varied following the objected tooth, so the adjacent structures lens and thyroid gland would be fragile to radiation. And the scattered radiation is one of the complicated problems in the protection because of specificity of dental x-ray and its object structures. The author, by using TLD (Thermo luminescent Dosimeter; Teledyne Isotopes-Model 7300, Element; TLD 200(CaF₂:Dy) and Capintec(Capintec Model 192, PM-30 Diagnostic chamber 28㎖ active volume), tried a measurement of air dose distribution of the scattered radiation and the irradiated dose of lens and thyroid gland under the condition of taking the film on the left maxillary molar. The results were as follows: 1. The half value layer of adapted dental x-ray machine was measured, and is 1.44㎜ Al. 2. The time of irradiation on the left maxillary molar in the Alderson Rando Phantom, the measured doses of left and right lens, and thyroid gland were 8,9mR, 1,2mR and 2,8mR. Under the same conditions, the scattered radiation at the distance of 1 meter from the phantom were 84 μR at the front side, 11μR at the back side, 18μR at the right side and 72μR at the left side. 3. Under the same conditions, the dose showed higher value by about 5% in the presence of object(phantom) than in the case of absence.

• 대한약침학회지
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• 제23권3호
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• pp.165-172
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• 2020

Objectives: In the past few years, herbal medicines have gained popularity over synthetic drugs because of their natural source and minimal side effects which has led to a tremendous growth of phytopharmaceuticals usage. With the development of nanotechnology, it provides alternative approaches to overcome several limitations using nano-formulations. In spite of considerable quantity of antianemic preparations with different iron forms available, currently additives are used and represented in modern pharmaceutical market. Iron deficiency anemia is a major global public health problem which particularly affects pregnant women, children and elderly persons. The situation is complicated because of disadvantages and drug side effects from existing antianemic medicines. There is a great demand for the development of new antianemic preparations. Green synthesis of iron oxide nanoparticles, possess high potential in this field. Methods: Our study focuses on developing green synthesis of iron oxide nanoparticles (IONPs) of 10-50 nm with spherical shape where different dosages were used -1 mg/kg, 10 mg/kg and 100 mg/kg for exposure in Wistar albino female rats for 28 days. The toxicity was assessed using various parameters such as measurements of the rat body and organ mass, hematology, biochemical evaluation and histopathological examinations. Results: No significant differences were observed in body and organ weights. Hematological indices also indicated no significant differences whereas biochemical factors showed increase in levels of direct bilirubin and globulin of medium as well as high dose and SGPT levels were increased only in high dose. The major organs (heart, kidney and liver) showed histopathological alterations in 10 and 100 mg/kg whereas brain showed only in 100 mg/kg. Conclusion: The toxicity of IONPs was found to be more significant when the concentration was increased; however, low doses can be used for further investigation as an antianemic preparation.

• 한국콘텐츠학회논문지
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• 제13권9호
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• pp.288-294
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• 2013

흉부 디지털토모장치는 가장 발달한 촬영방법중의 하나이지만 일반 흉부촬영방법에 비해 환자의 피폭선량이 높다는 단점이 있다. 이런 이유 때문에 본 연구는 흉부 디지털토모영상에서 부가여과를 사용하여 환자선량을 저감시키는 방법을 검토하여 보았으며, 화질의 변화도 실험하였다. 그 결과 부가여과가 없는 장치의 기본상태에서 피부입사선량, 면적선량, 실효선량은 1.95 mGy, 17.66 $dGycm^2$, 0.133 mSv로, 부가여과사용시는 0.312 mGy, 2.27 $dGy.cm^2$, 0.052 mSv로 나타나 선량이 각 각 66.2%, 73.6%, 57.4%로 감소하였다. 화질에서 병소의 검출율은 중심부 미소병소 검출율(p < .001)을 제외한 나머지 주변부, 중심부병변 및 주변부 미소병소에서는 두 방법에서 큰 차이를 보이지 않았으며, 환자의 선량감소에는 큰 효과를 볼 수 있었다.

• Reproductive and Developmental Biology
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• 제37권4호
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• pp.169-174
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• 2013

Sperm capacitation refers to polymerization of filamentous (F)-actin from globular (G)-actin. While the role of actin-related protein 2/3 (Arp2/3) complex in actin polymerization is well appreciated, the underlying mechanism(s) and its relationship with capacitation are poorly understood. Therefore, to evaluate the potential role of Arp2/3 complex on capacitation, bovine spermatozoa were incubated with multiple doses (1, 10 and $100{\mu}M$) of CK-636, an inhibitor of Arp2/3 complex with heparin. The cellular localization of the Arp2/3 complex in spermatozoa was identified by immunohistochemistry, whereas western blot was also applied to detect the protein tyrosine phosphorylation of sperm proteins. Additionally, sperm motility and kinematic parameters were evaluated using a computer-assisted sperm analysis system. CK-636 resulted in significant changes in the ratio of Arp2/3 complex localization between acrosome and equatorial region of the spermatozoa. Short-term exposure of spermatozoa to $100{\mu}M$ of CK-636 significantly decreased sperm motility, however a non-detectable effect on protein tyrosine phosphorylation was observed during capacitation. On the basis of these results, we propose that Arp2/3 complex is associated with morphological changes during capacitation and compromised sperm motility.

• 동의생리병리학회지
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• 제20권4호
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• pp.966-972
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• 2006

The effect of water extract of Chungjogupae-tang (CJGPT) was investigated _on the growth of human lung carcinoma A549 cells. Methods: MTT assay and fluorescent microscope peformed to compare and examine the efficacy of CJGPT treatment on the cytostaticity of lung cancer cells in proportion to time and doses, and DAPI staining and Western blot analysis were used to examine their effect on apoptosis. In addition, the quantitative RT-PCR was used to examine to lung cancer cells growth, and Prostaglandin E2 activity were measured. Results: Exposure of A549 cells to CJGPT respited in the growth inhibition and apoptosis in a dose-dependent manner as measured by MTT assay and fluorescent microscope. The antiproliferative effect by CJGPT treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. CJGPT treatment resulted in an up-regulation of cyclin-dependent kinase inhibitor p21 (WAFl/CIPl) in a p53-independent fashion. We found that CJGPT treatment decreased the levels of cyclooxygenase (COX)-2 and inducible nitric oxide synthease (iNOS) expression without significant changes in the expression of COX-1 , which was correlated with a decrease in prostaglandin E2 (PGE2) synthesis. Conclusion: These findings suggested that CJGPT-induced inhibition of human lung carcinoma A549 cell growth was connected with the induction of apoptotic cell death and the results provided important new insights into the possible molecular mechanisms of the anti-cancer activity of CJGPT.

• Toxicological Research
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• 제33권4호
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• pp.305-313
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• 2017

Accumulating epidemiological evidence indicates that exposure to fine air pollution particles (APPs) is associated with a variety of adverse health effects. However, the exact physiochemical properties and biological toxicities of fine APPs are still not well characterized. We collected four types of fine particle (FP) (diesel exhaust particles [DEPs], natural organic combustion [NOC] ash, synthetic organic combustion [SOC] ash, and yellow sand dust [YSD]) and investigated their physicochemical properties and in vitro biological toxicity. DEPs were almost entirely composed of ultrafine particles (UFPs), while the NOC, SOC, and YSD particles were a mixture of UFPs and FPs. The main elements in the DEPs, NOC ash, SOC ash, and YSD were black carbon, silicon, black carbon, and silicon, respectively. DEPs exhibited dose-dependent mutagenicity even at a low dose in Salmonella typhimurium TA 98 and 100 strains in an Ames test for genotoxicity. However, NOC, SOC, and YSD particles did not show any mutagenicity at high doses. The neutral red uptake assay to test cell viability revealed that DEPs showed dose-dependent potent cytotoxicity even at a low concentration. The toxicity of DEPs was relatively higher than that of NOC, SOC, and YSD particles. Therefore, these results indicate that among the four FPs, DEPs showed the highest in vitro biological toxicity. Additional comprehensive research studies such as chemical analysis and in vivo acute and chronic inhalation toxicity tests are necessary to determine and clarify the effects of this air contaminant on human health.