• Korean Journal of Environment and Ecology
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• v.20 no.3
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• pp.345-351
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• 2006

This study investigates the toxic effects of $Cd^{2+}$on frog (Rana dybowskii) by the determination of oocyte maturation and development of embryo exposure to different concentrations of the toxicant. The results show that $Cd^{2+}$ concentration of 0.1ppm suppressed the maturation of the oocytes. To examine the reversibility of the inhibitory effects, the oocytes were exposed to the $Cd^{2+}$ only for 3 hours, and then transferred to plain medium and cultured further for 17 hours. The oocytes were recovered from the toxic effect of the $Cd^{2+}$ when they were exposed to 1ppm, but not to 2.5ppm of the $Cd^{2+}$. The development of 2 cell embryos to 32 cell was completely suppressed at 0.1ppm and the longer the embryos were exposed to the $Cd^{2+}$, the more damage appeared to the embryos and the cytolysis of the 32 cell was induced by $Cd^{2+}$ at 0.1ppm. On the other hand, the embryos of blastula stage were cultured 96 hours in presence of the $Cd^{2+}$ at various concentrations and were examined. The rates of mortality and malformed larvae were investigated by probit analysis. From the results of LC$_{50}$ of 0.1ppm and EC$_{50}$ of 0.08ppm, Tl of 5.0 was derived, which indicates $Cd^{2+}$ is to be considered a teratogenic compound. Such specific malformations occurred in 14.3% as spine deformations at the 0.05ppm, in 75.0% as tail deformations at the 0.1ppm, in 66.7% as abdominal deformations at the 0.01ppm and in 26.0% as profound deformations at the 0.1ppm of $Cd^{2+}$ concentration which living embryos were exposed to. $Cd^{2+}$ suppressed growth to head-tail length at 0.1ppm. In conclusion, The study results reveal that $Cd^{2+}$ must be considered highly toxic effect to oocyte maturation and embryonic development.

• The Korean Journal of Quaternary Research
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• v.2 no.1
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• pp.25-50
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• 1988

The survival of rich evidence of palaeolithic occupation found in the Imjin-Hant'an River basin was possible due to many fortuitous geological conditions provided there. Formation of the basalt plain in a narrow valley system which developed during the late Mesozoic insured the appearance of a basin of sedimentation in which archaeological sites would be preserved with relatively minor post-depositional disturbance. Geomagnetic and K-Ar dating indicates that lava flows occurred during the Brunes Normal Epoch. During and after the process of basin sedimentation, erosion of the plain was confined to the major channel of the present river system which developed along the structural joints formed by the lava flow. Due to characteristic columnar structure and platy cleavage of the basalt bedrock, erosion of the basalt bedrock occurred mainly in vertical direction, developing deep but narrow entrenched valleys cut into the bedrock. Consequently, the large portion of the site area remained intact. Cultural deposits formed on top of the basalt plain were left unmodified by later fluvial disturbances due to changes in the Hant'an River base-level, since they were formed about 20 to 40m above the modern floodplain. Sedimentological evidence of cultural deposits and palynological analysis of lacustrine bed formed in the tributary basin of the Hant'an River indicate that hominid occupation occurred in this basin under rapidly deteriorating climatic conditions. From three thermoluminescence dates, the timing of hominid occupation as represented by 'Acheulian-like' bifaces apparently occur sometime during 45,000 BP. Thus, deposition of cultural layers in this basin approximately coincides with the beginning of the second stadial of the final glacial, during which the Korean Peninsula must have had provided a sanctuary for prolonged human occupation.

• The Journal of Internal Korean Medicine
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• v.28 no.1
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• pp.34-46
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• 2007

Objectives: This study was to assess characteristics in acute stroke patients according to Sasangconstitution (SC). Methods : We assessed the type of SC of acute stroke patients in $2^{nd}$ Department of Internal Medicine at KyungHee University Oriental Hospital from October 2005 to September 2006. Each subject's SC type was confirmed when the result of QSCC II+ was in accordance with the opinion of the Sasangconstitutional medicine specialist. We investigated general characteristics, stroke type, blood test results, alcohol drinking, smoking and dietary preferences according to SC. Results: 108 subjects were included in the final analysis. This study showed that out of the total patients, the proportion of So-yang to Tae-eum to So-eum was equal to 5.5 to 3.5 to 1. Especially, men were higher proportion So-yang while women recorded a more significant ratio of Tae-eum. Also, the BMI, waist circumference, hip circumference, and WC/HC ratio recorded significantly high results. The result indicated that even though the Tae-eum let on the highest numerical value in the aspect of their past history and the final diagnosis, no significant difference was revealed according to SC. The ratio of cerebral infarction to cerebral hemorrhage was 9 to 1. SVO, LAA, SUE are the 3 types of cerebral infarction classified by TOAST; SVO ranked the highest while SUE ranked the lowest in all constitutions. The blood test result displayed that averages of both TL and the T-chol were the highest in Tae-eum while that of hematocrit in So-yangand that of HDL-chol in So-eum. However, there was no significant difference. There were no significant differences classified by gender or by SC in the aspect of the alcohol drinking and smoking history. The majority of So-yang and Tae-eum demonstrated a preference for meat while So-eum and So-yang displayed high preferences for sea food. Conclusions : With respect to these results. we could observe the general disposition of various characteristic distributions according to SC of acute stroke patients. For further research in this field. it seems necessary to construct fundamental databases for the prevention and treatment of stroke by increasing the number of patients observed and by analyzing delicate characteristics of each constitution type.

• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.2
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• pp.41-47
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• 2021

Purpose There are many cyclotrons compared to the land area of the Republic of Korea. Because GMP certification is required and the nuclear medicine test does not apply for insurance, the number of examinations for nuclear medicine is decreasing. Therefore, there is a high probability of early decommissioning of the cyclotron. However, we do not unusually perform the radioactivation evaluation on concrete that can be classified as radioactive waste during the decommissioning of the cyclotron. In this study, we aim to confirm the radioactivation in the concrete surface using Handheld Radionuclide Identification Devices (RIDs). Materials and Methods Because there is no cyclotron being decommissioning in the Republic of Korea, it was impossible to perform the coring of concrete for radioactivation analysis. In this study, we used the KIRAMS-13 and analyzed the concrete surface in the target direction in the cyclotron room. After setting the target direction as the center, radionuclides were measured for about five months at thirty points with vertical and horizontal intervals of 30 cm. We used the RIIDEye(Detector: NaI(Tl) detector, manufacturer: Thermo) in this study and set the measurement time per point to one day (24 hours). Results Co-60 and Cs-137 were detected in some measurement points, and we confirmed the radioactivity of Co-60 detected at the most points. As a result, we found that the radioactivity of Co-60 was high in the diagonal direction (from the lower-left direction to the upper right direction) based on the center of the target. However, we think it is impossible to apply the corresponding results to all cyclotrons because we performed the study using only one cyclotron. Conclusion In thirty measurement points, we could confirm the radioactive nuclides and the relative radioactivity using the results of portable nuclides analyzer. Therefore, we expect that we can use the portable nuclides analyzer to select the coring position of concrete during the decommissioning of the cyclotron. Also, if we secure the radioactivation data for several years, we expect to make a more accurate estimate of radioactive waste during the preparation period of decommissioning of the cyclotron.

• Radiation Oncology Journal
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• v.14 no.1
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• pp.1-8
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• 1996

Purpose: We tried to evaluate the role of conventional radiotherapy alone or with neoadjuvant chemotherapy in oropharyngeal cancer in terms of survival rates and to identify prognostic factors affecting survival by retrospective analysis. Materials and Methods: Forty seven patients of oropharyngeal cancer were treated by conventional radiotherapy in our hospital from Nov. 1985 to APr. 1993. Of these, twenty six patients were treated by conventional radio-therapy alone, and 21 patients with neoadjuvant chemotherapy of mostly two or more cycles of cisplatin and pepleomycin. The Patient characteristics of radiotherapy alone group and neoadjuvant chemotherapy group were not different generally. Radiotherapy was performed by 6MV-LINAC and the total radiation doses of Primary tumors were 54.0-79.2 Gy and cervical lymph nodes were 55.8-90.0 Gy with a fraction size of 1.8 or 2.0 Gy per day. The range of follow-up periods was 3-102 months and median was 20 months. The range of a9e was 33-79 years old and median was 58 years old. Results : Overall 3-year actuarial survival rate (3YSR) of all patients was $39\%$. The 3YSRS of stage I (n=5), II (n=11), III (n=12) and IV (n=19) were 60, 55, 33 and $32\%$, respectively The 3YSRS of Tl+2, T3+4 and No, N+ were 55, $18\%$ (p=0.005) and 43, $36\%$ (p>0.1), respectively. There was no difference in 3YSRS between radiotherapy alone group and neoadjuvant chemotherapy group (38 vs $43\%$, p>0.1). According to the original site of primary tumor, the 3YSRS of tonsil (n=32), base of tongue (n=8), soft palate or uvula (n=6) and pharyngeal wall (n=1) were 36 38, 67 and $0\%$, respectively The Patients of soft palate or uvular cancer had longer survival than other primaries but the difference was not significant statistically (p>0.1). Of 32 patients of tonsillar cancer, 22 Patients who had primary extension to adjacent tissue showed inferior survival rate to the ones who had not Primary extension, but the difference was marginally significant statistically (24 vs $60\%$, p=0.08). On Cox multivariate analysis in entire patients with variables of age, T stage, N stage, total duration of radiotherapy, the site of primary tumor and the use of neoadjuvant chemotherapy, only T stage was a significant Prognostic factor affecting 3YSR. Conclusion : The difference of 3YASRS of conventional radiotherapy alone group and neoadjuvant chemotherapy group was not significant statistically. These treatments could be effective in oropharyngeal cancer of early stage, especially such as soft palate, uvular or tonsillar cancer which did not extend to adjacent tissue. But in order to improve the survival of patients of most advanced oropharyngeal cancer, other altered fractionated radiotherapy such as hyperfractionation rather than conventional fractionation or multi-modal approach combining radiotherapy and accessible surgery or concurrent chemotherapy might be beneficial.