• Restorative Dentistry and Endodontics
• /
• v.35 no.6
• /
• pp.453-460
• /
• 2010

Objectives: To evaluate the accuracy and consistency of two different apex locators at both the Apex and 0.5 marks. Materials and Methods: Twenty-six root canals was scheduled for extraction for periodontal or prosthodontic reasons. Thirteen canals were measured using Root ZX and the rest by i-ROOT. The root canal length was measured both the at 0.5 mark and the Apex mark. The file was then fixed to the toot, and the distance from the file tip to the major foramen of each canal was measured after removing the root dentin under the microscope so that the major foramen and the file tip were seen. Results: 1. When the Apex mark was used, 100% of both the Root ZX and i-ROOT groups were within 0.5 mm of the major foramen. 2. When 0.5 mark was used, 100% of the Root ZX group and 77% of the i-ROOT group were within 0.5 mm of the major foramen. 3. In terms of standard deviation and quartile value, the Apex mark was more consistent than 0.5 mark in the Root ZX group, and 0.5 mark was more consistent in the i-ROOT group, but there was no statistically significant difference when compared with t-test. 4. The root canal length difference between the Apex mark and 0.5 mark was 0.22 mm and 0.46 mm in the Root ZX and i-ROOT groups, respectively. Conclusions: In this study, the Apex mark was the more consistent mark. Therefore, it is recommended to subtract 0.5 mm, which is the average length between the apex and apical constriction, from the root canal length at the Apex mark to obtain the working length clinically.

• Journal of Food Hygiene and Safety
• /
• v.34 no.5
• /
• pp.413-420
• /
• 2019

In this study, a sample preparation method and a simultaneous determination method by ultra-high performance liquid chromatography coupled with tandem mass spectrometry for 9 isomers of chlorogenic acid and arbutin in fruits were developed. The samples were extracted using 90% methanol (pH 3.0), with the solutions being shaken and then sonicated for 10 min each. After centrifugation at 4,000 rpm for 10 min, the extraction was concentrated under a vacuum at $40^{\circ}C$ using a vacuum evaporator. The residue was dissolved in 5 mL of 5% methanol and filtered through a $0.45{\mu}m$ membrane before UHPLC-MS/MS analysis. The separations were performed on a C18 column with gradient elution of water (containing 0.1% formic acid) and methanol (containing 0.1% formic acid). The specificity, linearity, limit of detection, limit of quantification, accuracy, and precision of the proposed methods were also evaluated.

• Korean Journal of Environmental Agriculture
• /
• v.40 no.4
• /
• pp.353-358
• /
• 2021

BACKGROUND: Prochloraz has been widely used as an imidazole fungicide on fruits and vegetables in Korea. Analytical approaches to evaluate prochloraz residues in herbal medicine are required for their safety management. In this study, we developed a GC-ECD method for quantitative determination of prochloraz in Platycodi Radix. The metabolite 2,4,6-trichlorophenol (2,4,6-T) was used as a target compound to evaluate total prochloraz residues as it is categorized to a representative residue definition of prochloraz. All residues containing 2,4,6-T were converted to 2,4,6-T and subjected to GC-ECD. METHODS AND RESULTS: In order to verify the applicability, the method was optimized for determining prochloraz and it metabolite 2,4,6-T in Platycodi Radix. Prochloraz and its metabolite 2,4,6-T residuals were extracted using acetone. The extract was diluted with and partitioned directly into dichloromethane to remove polar co-extractives in the aqueous phase. The extract was decomposed to 2,4,6-T, and then the partitioned ion-associate was finally purified by optimized aminopropyl solid-phase extraction (SPE). The limits of quantitation of the method (MLOQs) were 0.04 mg/kg and 0.02 mg/kg, respectively for prochloraz and 2,4,6-T, considering the maximum residue level (MRL) of prochloraz as 0.05 mg/kg in Platycodi Radix. Recovery tests were carried out at two levels of concentration (MLOQ, 10 MLOQ) and resulted in good recoveries (82.1-89.7%). Good reproducibilities were obtained (coefficient of variation < 2.8%), and the linearities of calibration curves were reasonable (r² > 0.9986) in the range of 0.005-0.5 ㎍/mL. CONCLUSION(S): The method developed in this study was successfully validated to meet the guidelines required for quantitative determination of pesticides in herbal medicine. Thus, the method could be useful to monitor prochloraz institutionally in herbal medicine.

• Journal of the Korean earth science society
• /
• v.42 no.2
• /
• pp.201-220
• /
• 2021

The objective of this study is to increase awareness and interest regarding polar science and thereby aid in establishing the concept and future direction of polar literacy. To analyze the current status, textbooks based on the common school curriculum pertaining to polar topics were reviewed. Six countries that actively conduct polar science, namely Korea, France, Japan, Germany, the United States, and the United Kingdom, were chosen. Subsequently, 402 cases in 110 science and social studies (geography) textbooks of these countries were analyzed through both quantitative and qualitative methods. Based on the obtained results, the importance of polar research in geoscience education and the need for spreading awareness regarding polar research as an indicator of global environmental changes were examined. It was found that the primary polar topics described in the textbooks are polar glaciers, polar volcanism, solid geophysics, polar infrastructure, and preservation of geological resources and heritage. This demonstrates that the polar region is a field of research with important clues to Earth's past, present, and future environments and is also a good teaching subject for geological education. However, an educational approach is needed for systematically laying emphasis on polar research. The implications of this study are manifold, such as the establishment of a cooperative system between polar scientists and educators, extraction of core concepts for polar literacy and content reconstruction, discovery of new polar topics associated with the curriculum, diversification of forms of presentation in textbooks, and development of an affective image that is based on correct cognitive understanding. Furthermore, through the continuance of polar topics in textbooks, students can improve their awareness regarding polar literacy and polar science culture, which in turn will serve as the driving force for sustainable polar research in the future.

• Journal of Nutrition and Health
• /
• v.52 no.4
• /
• pp.399-407
• /
• 2019

Purpose: This study was conducted to evaluate the physicochemical properties of different batches of Saururus chinensis using different roasting temperature that were dried at different using different roasting temperatures and their were determined the antioxidative activities of water and 70% ethanol extracts. Methods: Extracts were examined for the total phenolic acid content, the and flavonoids contents and the antioxidant properties, including DPPH radical scavenging activity, ABTs scavenging activity and, the reducing power. Results: Moisture content was significantly higher in the LSC and the crude ash content was significantly higher in the HSC. The crude protein content was higher in the LSC (although not significantly), and the crude fat and carbohydrate contents were higher in the HSC (although not significantly). The total phenolic content was lower in the samples extracted with water, but there was no significant difference. However, the extracts extracted with 70% ethanol at a high drying temperature were significantly higher. The low temperature and high drying temperature batches of Saururus chinensis were significantly higher in the samples extracted with 70% ethanol than those extracted with 70% ethanol. The total phenolic acid content, the total flavonoid content and the electron donating ability were highest in the ethanol extract of Saururuschinensis treated at a high temperature. However, the ABTs radical activity was highest in the water extracted, high-temperature treated Saururuschinensis. The 70% ethanol extract of high temperature roasted Saururuschinensis had the highest antioxidative activities of all the Saururuschinensis batches. Conclusion: The total phenolic acid contents, total flavonoid contents, electron donating activity and reducing power activity were highest in all the 70% ethanol extraction batches of the high-temperature treated samples.

• Korean Journal of Clinical Laboratory Science
• /
• v.51 no.3
• /
• pp.309-315
• /
• 2019

Cervical cancer is the fourth most common malignant neoplasm in women worldwide. Most cases of cervical cancer are caused by an infection by the human papillomavirus. Molecular diagnostic methods have emerged to detect the HPV for sensitivity, specificity, and objectivity. In particular, real-time PCR has been introduced to acquire a more sensitive target DNA or RNA. RNA extraction and complementary DNA synthesis are proceeded before performing real-time PCR targeting RNA. To identify an adequate and sensitive cDNA synthesis kit, this study evaluated the two commonly used kits for cDNA synthesis. The results show that the $R^2$ and efficiency (%) of the two cDNA synthesis kits were similar in the cervical cancer cell lines. On the other hand, the Takara kit compared to Invitrogen kit showed P<0.001 in the $10^2$ and $10^3$ SiHa cell count. The Takara kit compared to the Invitrogen kit showed P<0.001 in the $10^1$ and $10^2$ HeLa cell count. Furthermore, 8, 4, 2, 1, and 0.5 ml of forty exfoliated cell samples were used to compare the cDNA synthesis kits. The Takara kit compared to the Invitrogen kit showed P<0.01 in 8, 4, and 1 ml and P<0.05 in 0.5 mL. The study was performed to identify the most appropriate cDNA synthesis kit and suggests that a cDNA synthesis kit could affect the real-time PCR results.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.22 no.2
• /
• pp.74-78
• /
• 2018

Purpose $[^{11}C]$acetate has been proved useful in detecting the myocardial oxygen metabolism and various malignancies including prostate cancer, hepatocellular carcinoma, renal cell carcinoma and brain tumors. The purpose of study was to improve the radiosynthesis yield of $[^{11}C]$acetate on a automated radiosynthesis module. Materials and Methods $[^{11}C]$acetate was prepared by carboxylation of grignard reagent, methylmagnesium chloride, with $[^{11}C]$$CO_2$ gas, followed by hydrolysis with 1 mM acetic acid and purification using solid phase extraction cartridges. The effect of the reaction temperature ($0^{\circ}C$, $10^{\circ}C$, $-55^{\circ}C$) and cyclotron beam time (10 min, 15 min, 20 min, 25 min) on the radiosynthesis yield were investigated in the $[^{11}C]$acetate labeling reaction. Results The maximum radiosynthesis yield was obtained at $-10^{\circ}C$ of reaction temperature. The radioactivities of $[^{11}C]$acetate acquired at $-10^{\circ}C$ reaction temperature was 2.4 times higher than those of $[^{11}C]$acetate acquired at $-55^{\circ}C$. Radiosynthesis yield of $[^{11}C]$acetate increased with increasing cyclotron beam time. Conclusion This study shows that radiosynthesis yield of $[^{11}C]$acetate highly dependent on reaction temperature. The best radiosynthesis yield was obtained in reaction of grignard reagent with $[^{11}C]$$CO_2$ at $-10^{\circ}C$. This radiolabeling conditions will be ideal for routine clinical application.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.34 no.3
• /
• pp.27-54
• /
• 2021

Objectives : This review was conducted to validate the effectiveness and safety of herbal medicine combined with conventional therapy for rosacea. Methods : Randomized controlled trials(RCTs) reporting the effects of herbal medicine treatment on rosacea were searched through eight electronic databases from 2016 to March 17, 2020. This study collection and data extraction were performed by two independent reviews. The Cochrane risk-of-bias tool was used for the evaluation of the risk of bias in all included RCTs. Mean differences(MD) and Risk ratio(RR) of 95% Confidence intervals(Cls) were calculated and data synthesis was conducted using Review Manager(RevMan, ver.5.4) Results : Eighteen RCTs were included and all trials compared the combined therapy of herbal medicine with conventional western therapy to conventional therapy alone. The effective rate of the combination of herbal medicine with western medicine(RR 1.20, 95% CI : 1.13-1.28, p<0.00001, I²=0%), the effective rate of the combination of herbal medicine with laser-based therapy(RR 1.12, 95% CI : 1.04-1.21, p=0.004, I²=18%) and the effective rate of the combination treatment group using herbal medicine, western medicine and external drugs were all statistically higher that of the control group(RR 1.19, 95% CI : 1.11-1.28, p<0.00001, I²=0%). The score of non transient erythema(MD -0.36, 95% CI : -1.01 0.29, p=0.27, I²=93%), flushing(MD -0.69, 95% CI : -0.97, 0.41, p<0.00001, I²=32%), papules or pustules(MD 0.10, 95% CI : -0.15, 0.35 p=0.44, I²=0%) were also seen in the herbal medicine and western medicine combination group. The overall risk of bias of the included studies was some concerns. No serious adverse effects were observed. Conclusions : This review found the safety and effectiveness of the combined therapy of herbal medicine with conventional western therapy for rosacea.

• Journal of Intelligence and Information Systems
• /
• v.27 no.3
• /
• pp.175-197
• /
• 2021

Recently, with the development of deep learning technology, research on unstructured data analysis is being actively conducted, and it is showing remarkable results in various fields such as classification, summary, and generation. Among various text analysis fields, text classification is the most widely used technology in academia and industry. Text classification includes binary class classification with one label among two classes, multi-class classification with one label among several classes, and multi-label classification with multiple labels among several classes. In particular, multi-label classification requires a different training method from binary class classification and multi-class classification because of the characteristic of having multiple labels. In addition, since the number of labels to be predicted increases as the number of labels and classes increases, there is a limitation in that performance improvement is difficult due to an increase in prediction difficulty. To overcome these limitations, (i) compressing the initially given high-dimensional label space into a low-dimensional latent label space, (ii) after performing training to predict the compressed label, (iii) restoring the predicted label to the high-dimensional original label space, research on label embedding is being actively conducted. Typical label embedding techniques include Principal Label Space Transformation (PLST), Multi-Label Classification via Boolean Matrix Decomposition (MLC-BMaD), and Bayesian Multi-Label Compressed Sensing (BML-CS). However, since these techniques consider only the linear relationship between labels or compress the labels by random transformation, it is difficult to understand the non-linear relationship between labels, so there is a limitation in that it is not possible to create a latent label space sufficiently containing the information of the original label. Recently, there have been increasing attempts to improve performance by applying deep learning technology to label embedding. Label embedding using an autoencoder, a deep learning model that is effective for data compression and restoration, is representative. However, the traditional autoencoder-based label embedding has a limitation in that a large amount of information loss occurs when compressing a high-dimensional label space having a myriad of classes into a low-dimensional latent label space. This can be found in the gradient loss problem that occurs in the backpropagation process of learning. To solve this problem, skip connection was devised, and by adding the input of the layer to the output to prevent gradient loss during backpropagation, efficient learning is possible even when the layer is deep. Skip connection is mainly used for image feature extraction in convolutional neural networks, but studies using skip connection in autoencoder or label embedding process are still lacking. Therefore, in this study, we propose an autoencoder-based label embedding methodology in which skip connections are added to each of the encoder and decoder to form a low-dimensional latent label space that reflects the information of the high-dimensional label space well. In addition, the proposed methodology was applied to actual paper keywords to derive the high-dimensional keyword label space and the low-dimensional latent label space. Using this, we conducted an experiment to predict the compressed keyword vector existing in the latent label space from the paper abstract and to evaluate the multi-label classification by restoring the predicted keyword vector back to the original label space. As a result, the accuracy, precision, recall, and F1 score used as performance indicators showed far superior performance in multi-label classification based on the proposed methodology compared to traditional multi-label classification methods. This can be seen that the low-dimensional latent label space derived through the proposed methodology well reflected the information of the high-dimensional label space, which ultimately led to the improvement of the performance of the multi-label classification itself. In addition, the utility of the proposed methodology was identified by comparing the performance of the proposed methodology according to the domain characteristics and the number of dimensions of the latent label space.

• Journal of Nutrition and Health
• /
• v.54 no.1
• /
• pp.10-22
• /
• 2021

Purpose: Key Foods refers to foods that have a high contribution in the nutrient intake of individuals, and exert important effects on their health. This study was undertaken to identify Korean Key Foods, using data from the 7th Korea National Health and Nutrition Examination Survey (KNHNES). Methods: The data source for the extraction of Key Foods was the 24-hour dietary survey data obtained from the 7th KNHNES (2016-2018), and 21,271 subjects were evaluated. A total of 17 nutrients were selected as the key nutrients for identifying the Key Foods, including energy, carbohydrates, protein, lipid, dietary fiber, calcium, phosphorus, iron, sodium, potassium, vitamin A, thiamin, riboflavin, niacin, vitamin C, cholesterol, and sugars. The nutrient consumption approach was applied to generate a list of potential Key Foods. Foods included in 85% of the cumulative intake contribution from one or more key nutrients, were subsequently selected as Key Foods. Results: Of the 1,728 foods consumed by survey respondents, we extracted 728 Key Foods. These Key Foods explained 94% key nutrient intakes of the subjects. Based on the contribution rate to key nutrient intake, the top 10 Key Foods identified were multigrain rice (5.32%), plain white rice (4.23%), milk (3.3%), cabbage kimchi (2.82%), grilled pork belly (1.56%), apples (1.52%), fried eggs (1.49%), cereal (1.36%), instant coffee mix (1.21%), and sweet potatoes (1.12%). These 10 foods accounted for 23.93% total key nutrient intake of the survey respondents. Conclusion: Seven hundred and twenty-eight foods were extracted and identified as the 2020 Korean Key Foods. These Key Foods can be considered the priority foods to be analyzed for establishing a national nutrient database.