• Molecules and Cells
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• v.41 no.5
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• pp.413-422
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• 2018

Soybean transgenic plants with ectopically expressed AtABF3 were produced by Agrobacterium-mediated transformation and investigated the effects of AtABF3 expression on drought and salt tolerance. Stable Agrobacterium-mediated soybean transformation was carried based on the half-seed method (Paz et al. 2006). The integration of the transgene was confirmed from the genomic DNA of transformed soybean plants using PCR and the copy number of transgene was determined by Southern blotting using leaf samples from $T_2$ seedlings. In addition to genomic integration, the expression of the transgenes was analyzed by RT-PCR and most of the transgenic lines expressed the transgenes introduced. The chosen two transgenic lines (line #2 and #9) for further experiment showed the substantial drought stress tolerance by surviving even at the end of the 20-day of drought treatment. And the positive relationship between the levels of AtABF3 gene expression and drought-tolerance was confirmed by qRT-PCR and drought tolerance test. The stronger drought tolerance of transgenic lines seemed to be resulted from physiological changes. Transgenic lines #2 and #9 showed ion leakage at a significantly lower level (P < 0.01) than ${\underline{n}}on-{\underline{t}}ransgenic$ (NT) control. In addition, the chlorophyll contents of the leaves of transgenic lines were significantly higher (P < 0.01). The results indicated that their enhanced drought tolerance was due to the prevention of cell membrane damage and maintenance of chlorophyll content. Water loss by transpiration also slowly proceeded in transgenic plants. In microscopic observation, higher stomata closure was confirmed in transgenic lines. Especially, line #9 had 56% of completely closed stomata whereas only 16% were completely open. In subsequent salt tolerance test, the apparently enhanced salt tolerance of transgenic lines was measured in ion leakage rate and chlorophyll contents. Finally, the agronomic characteristics of ectopically expressed AtABF3 transgenic plants ($T_2$) compared to NT plants under regular watering (every 4 days) or low rate of watering condition (every 10 days) was investigated. When watered regularly, the plant height of drought-tolerant line (#9) was shorter than NT plants. However, under the drought condition, total seed weight of line #9 was significantly higher than in NT plants (P < 0.01). Moreover, the pods of NT plants showed severe withering, and most of the pods failed to set normal seeds. All the evidences in the study clearly suggested that overexpression of the AtABF3 gene conferred drought and salt tolerance in major crop soybean, especially under the growth condition of low watering.

• Development and Reproduction
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• v.10 no.4
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• pp.247-254
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• 2006

It is well publicized that the existence of various endocrine disrupting chemicals threatens normal sexual development of many sedentary marine fishes in the coastal areas. However, a suitable marine fish species for efficient monitoring of this threatening has yet to be identified. One of the difficulties in estimating the effect of endocrine disruption in marine fish is the absence of clear distinction between testicular and ovarian structures at the early stages of sex differentiation. In search of a potential test species, we have investigated the microscopic structures of sexually undifferentiated and differentiated gonads and the susceptibility of gonadal differentiation to exogenous sex steroids during the sex differentiation period in a sedentary marine rockfish, Sebastes schlegeli. Male gonads in this species contained dark pigmentation that made them distinct from female gonads. Treatment either with $estradiol-17\;{\beta}(E_2)$ or $17\;{\alpha}-methyltestosterone$ (MT) significantly altered the sex ratios with the complete sex changes or the occurrence of ovotestis that was easily identified by the mixed structure of dimorphic gonads (coexistence of ovarian cavity/primary oocytes and dark pigmentation/seminiferous tubules). Results in this study suggest that S. schlegeli can be developed as a monitoring/test fish species for endocrine disruption in marine fish in the coastal areas.

• Parasites, Hosts and Diseases
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• v.58 no.2
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• pp.147-152
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• 2020

Malaria is a potent burden on public healthcare worldwide due to requiring rapid diagnosis and treatment. Nowadays, prompt diagnosis with rapid diagnostic tests (RDTs) has been widely accepted as an effective diagnostic technique in malaria-endemic countries, primarily due to their easy operation, fast output, and straightforward interpretation. The global availability and use of RDTs have gradually grown over recent decades as field-applicable diagnostic tests for the reliable confirmation of malaria infection and proper case management. This study was conducted to evaluate diagnostic performance of 3 commercially available malaria RDT kits : BIOCREDIT^TM Malaria Ag Pf(pLDH), Malaria Ag Pf(pLDH/pHRPII), and Malaria Ag Pf/Pv(pLDH/pLDH) (where pLDH and pHRPII stand for plasmodium lactate dehydrogenase and histidine-rich protein 2, respectively) for the specific detection of Plasmodium falciparum. A total of 1,129 blood samples including 95 blood samples, confirmed as vivax malaria infection by microscopic examinations and a nested-PCR method, were tested for falciparum malaria infection. The overall sensitivity and specificity of Malaria Ag Pf(pLDH/pHRPII), Malaria Ag Pf/Pv(pLDH/pLDH), and Pf(pLDH) for P. falciparum were 99.0% and 100%, 95.8% and 100%, and 100% and 100%, respectively. It is proposed that the 3 RDT kits perform reliable level of diagnostic accuracy of detection for P. falciparum parasites.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1319-1325
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• 2000

Antimicrobial effects of the specific IgY separated from eggs which were laid by hens vaccinated with Streptococcus mutans were investigated. The comparison tests of vaccination, addition levels of crude specific IgY, and innoculation concentration were applied by microscopic observation and turbidity test. Ten% addition of crude specific IgY obtained from vaccinated hens showed agglomerative clusters of S. mutans cells in supernatants and sediments, while crude IgY produced by non-vaccinated hens showed no cluster. IgY addition above 5% showed agglutinating clusters of most S. mutans cells and there was definite difference between IgY addition below 2.5% and above 5%. Concentration tests of crude IgY revealed that antimicrobial effects were differentiated by addition level and addition over 10% produced satisfactory results with turbidity test. The cluster size was dependent upon concentration of crude IgY addition. $10^5\;cfu/mL$ inoculation showed agglutinated cells and extent of agglomeration was proportional to cell numbers. Study of inoculation levels showed that 10% addition of crude IgY decreased turbidity effectively regardless of number of S. mutans cells. Plaque formation decreased to 75% with 15% addition of specific IgY concentration. These results implied that IgY separated from eggs laid by S. mutans-vaccinated hens might prevent dental caries caused by S. mutans.

• Journal of Life Science
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• v.29 no.1
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• pp.97-104
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• 2019

Streptococcus iniae is a typical fish pathogen causing streptococcosis and it can also cause zoonotic infectious diseases. We studied S. iniae FP5228 isolated from infected olive flounder in Wando, Korea. In a study to find virulence factors in FP5228, we found that the number of live bacteria decreased dramatically in culture medium containing S. iniae FP5228 for more than 24 hr. This phenomenon was hypothesized to be related to Toxin ${\zeta}$ and Antitoxin ${\varepsilon}$ genes, components of the Toxin/ Antitoxin (TA) system on the 14 kb plasmid of FP5228. We used a protein overexpression system to identify it. The pBP1140 vector system was constructed to regulate the expression of Toxin ${\zeta}$ and Antitoxin ${\varepsilon}$ by IPTG and Arabinose. E. coli/pBP1140 strain grew slowly in early growth under toxin expression condition, and it was confirmed by microscopic observation that the strain became longer. S. iniae CK287, lacking a 14 kb plasmid of S. iniae FP5228 strain, was constructed. CK287 bacterial cells did not show rapid killing during culture, and the ability to produce biofilm was also decreased, and toxicity was weakened in cytotoxicity test and fish test. These results suggest that the TA system is involved in physiological regulation and expression of virulence factors in S. iniae FP5228.

• Composites Research
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• v.36 no.4
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• pp.270-274
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• 2023

The stacking configuration of fiber-reinforced polymer (FRP) composites, achieved via the filament winding process, exhibits distinct variations compared to conventional FRP composite stacking arrangements. Consequently, it becomes challenging to ascertain the influence of mechanical properties based on the typical stacking structures. Thus, it becomes imperative to enhance the mechanical behavior and optimize the interleaved structures to improve overall performance. Therefore, this study aims to investigate the impact of incorporating amorphous halloysite nanotubes (A-HNTs) within different layers of five unique layer arrangements on the low-velocity impact properties of interleaved carbon fiber-reinforced polymer (CFRP) structures. The low-velocity impact characteristics of the laminate were validated using a drop weight impact test, wherein the resulting impact damage modes and extent of damage were compared and evaluated under microscopic analysis. Each interleaved structure laminate according to whether nanoparticles are added was compared at impact energies of 10 J and 15 J. In the case of 10 J, the absorption energy showed a similar tendency in each structure. However, at 15 J, the absorption energy varies from structure to structure. Among them, a structure in which nanoparticles are not added exhibits the highest absorption energy. Additionally, various impact fracture modes were observed in each structure through optical microscopy.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.2
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• pp.82-92
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• 2023

Urine sediments are performed by a microscopic examination of centrifuged urine by medical technologists. This study examined different urine sediment preparation procedures. The 107 fresh urine specimens that tested positive from white blood cells (WBCs) and red blood cells (RBCs) in the urine dipstick test and the cobas u 701 analyzer, respectively, were selected for manual microscopy. This study evaluated an automated urine sediment analyzer and three manual microscopy methods for WBCs and RBCs. The methods were performed according to the test guidelines. The coefficients of determination between the cobas u 701 analyzer and the Korean Association of Quality Assurance for Clinical Laboratory (KAQACL) for WBCs and RBCs were r2=0.977 and r2=0.970, respectively. The concordance rates between the cobas u 701 analyzer and KAQACL for WBCs and RBCs were 74.8% and 77.6%, respectively. A good correlation and concordance with the automatic analyzer were shown when the specimens were prepared and examined using the KAQACL method. Consequently, the differences in the urine sediment preparation procedures affected the sediment concentrations, influencing the cell number per high power field (HPF).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.399-401
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• 2022

A definitive diagnosis to classify the breast malignancy status may be achieved by microscopic analysis using surgical open biopsy. However, this procedure requires experts in the specializing of histopathological image analysis directing to time-consuming and high cost. To overcome these issues, deep learning is considered practically efficient to categorize breast cancer into benign and malignant from histopathological images in order to assist pathologists. This study presents a pre-trained convolutional neural network model architecture with a 100% fine-tuning scheme and Adagrad optimizer to classify the breast cancer histopathological images into benign and malignant using a 40× magnification BreaKHis dataset. The pre-trained architecture was constructed using the InceptionResNetV2 model to generate a modified InceptionResNetV2 by substituting the last layer with dense and dropout layers. The results by demonstrating training loss of 0.25%, training accuracy of 99.96%, validation loss of 3.10%, validation accuracy of 99.41%, test loss of 8.46%, and test accuracy of 98.75% indicated that the modified InceptionResNetV2 model is reliable to predict the breast malignancy type from histopathological images. Future works are necessary to focus on k-fold cross-validation, optimizer, model, hyperparameter optimization, and classification on 100×, 200×, and 400× magnification.

• Tuberculosis and Respiratory Diseases
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• v.57 no.6
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• pp.528-534
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• 2004

Background : Microscopic examination of sputum smears for acid-fast bacilli (AFB) is the most important and rapid diagnostic test for pulmonary tuberculosis. However, the AFB observed on the smear may represent either M. tuberculosis or nontuberculous mycobacteria (NTM). This study examined the clinical usefulness of a polymerase chain reaction test for M. tuberculosis (TB-PCR) for the differentiation of pulmonary tuberculosis and NTM lung disease in patients with smear-positive sputums in a tertiary hospital in Korea. Material and Methods : From January, 2003 to December, 2003, 826 AFB smear-positive and culture-positive sputum specimens were collected from 299 patients. Results : NTM were recovered from 26.6% (220/826) of the smear-positive sputum specimens and 23.4% (70/299) of the patients with smear-positive sputum. All the patients with isolated NTM had clinically significant NTM lung disease; 38 patients (54.3%) had M. avium and 26 patients (37.1%). had M. abscessus. In the patients with pulmonary tuberculosis, 78.7% of the patients (74/94) showed TB-PCR positivity, and all the patients with NTM lung disease showed negative results on the TB-PCR test (p<0.001). A positive result of the TB-PCR test on the sputum or bronchial washing fluid specimens was able to predict pulmonary tuberculosis with 88.4% sensitivity, 100% specificity, a 100% positive predictive value and a 79.7% negative predictive value for the patients with smear-positive sputum. Conclusion : The TB-PCR test for sputum specimens or bronchial washing fluid specimens could be useful for differentiating pulmonary tuberculosis and NTM lung disease for the patients with smear-positive sputum in Korea.

• Journal of Preventive Medicine and Public Health
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• v.26 no.2 s.42
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• pp.222-230
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• 1993

Industrial glues, known as 'Bonds' in Korea, contain many kinds of organic solvents, and glue sniffing of youths became one of the social problems in Korea. Mixed exposures to solvents by glue sniffing may induce chronic toxicities different from those by exposures to solvents of single component. To test effects of the glue sniffing on weight gain or central nervous system, two groups of 20 male Sprague-Dawley rats were exposed to air(control group) or vapors of the glues to narcotic status(exposed group), and weight check, tail flick test, hot plate test, rotarod treadmill test were done on the 14th,24th, 36th, 45th, 53rd, 86th, 102nd, 117th, 134th and 151st days after the first exposure. On the 188th day, their brains were excised and examined by a pathologist. Weight gain, controlled against time change, showed significant difference between the groups, but response times in tail flick test, hot plate tests, and rotarod treadmill test didn't. In pathological examination with blind method, no macroscopic or microscopic differences were found between the two groups. These results suggests that organic lesion in central nervous system may not ensue glue sniffing, but, before firm conclusion, more studies in various exposure conditions should be followed.