• Journal of Plant Biotechnology
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• 제47권1호
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• pp.26-39
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• 2020

In maize, immature embryos (IEs) are highly regenerative explants most suitable for producing high frequencies of plantlet regeneration in vitro. Apart from media, explants, and hormones, genotypic variation also influences in vitro characters to a great extent. In the present study, IEs were used to study the distinctive effect of variation of size/stage and hormones in different genotypes on five in vitro characters viz., frequency of callus induction, growth rate of total callus, frequency of E. callus induction, and volume and number of regenerated plantlets. LS medium with different concentrations of 2,4-D (0.5, 1.5, 2.5, 4.0 and 5.0 mg/L) were used to study the former four in vitro characters, and medium with 6-benzylaminopurine and kinetin (0.5 mg/L, each) was used for plantlet regeneration. IEs of 1.0, 1.5, 2.0, 2.5 and 3.0 mm in size were isolated from four inbred lines viz., NM74C, NM81A, NM5883 and NM5884. Two-way ANOVA revealed that explant size and genotypes, as well as hormonal concentrations showed significant effects on in vitro characters. Two millimeter IEs were found to be suitable for in vitro cultures. LS medium with 1.5 mg/L 2,4-D and LS with BAP and Kn (0.5 mg/L, each) were found to be the best hormonal concentrations for callus induction, maintenance, and regeneration, respectively. Among the four genotypes, NM81A and NM5883 yielded more non-embryogenic and Type I E. calli. In contrast, NM74C and NM5884 yielded more highly regenerative Type II calli. Inbred line NM5884 was found to be the best among these four genotypes.

• Journal of Periodontal and Implant Science
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• 제51권1호
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• pp.40-52
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• 2021

Purpose: Various crosslinking methods have been introduced to increase the longevity of collagen membranes. The aim of this study was to compare and evaluate the degradation and bone regeneration patterns of 3 collagen membranes. Methods: Four 8-mm-diameter circular bone defects were created in the calvaria of 10 rabbits. In each rabbit, each defect was randomly allocated to 1) the sham control group, 2) the non-crosslinked collagen sponge (NS) group, 3) the chemically crosslinked collagen membrane (CCM) group, or 4) the biphasic calcium phosphate (BCP)-supplemented ultraviolet (UV)-crosslinked collagen membrane (UVM) group. Each defect was covered with the allocated membrane without any graft material. Rabbits were sacrificed at either 2 or 8 weeks post-surgery, and radiographic and histologic analyses were done. Results: New bone formed underneath the membrane in defects in the CCM and UVM groups, with a distinctive new bone formation pattern, while new bone formed from the base of the defect in the NS and control groups. The CCM maintained its shape until 8 weeks, while the UVM and NS were fully degraded at 8 weeks; simultaneously, sustained inflammatory infiltration was found in the margin of the CCM, while it was absent in the UVM. In conclusion, the CCM showed longer longevity than the UVM, but was accompanied by higher levels of inflammation. Conclusions: Both the CCM and UVM showed distinctive patterns of enhancement in new bone formation in the early phase. UV crosslinking can be a biocompatible alternative to chemical crosslinking.

• Korean Journal of Radiology
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• 제22권3호
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• pp.354-365
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• 2021

Objective: To investigate the diagnostic performance of contrast-enhanced ultrasound (CEUS) and its role as a second-line imaging modality after gadoxetate-enhanced MRI (Gd-EOB-MRI) in the diagnosis of hepatocellular carcinoma (HCC) among at risk observations. Materials and Methods: We prospectively enrolled participants at risk of HCC with treatment-naïve solid hepatic observations (≥ 1 cm) of Liver Imaging Reporting and Data System (LR)-3/4/5/M during surveillance and performed Gd-EOB-MRI. A total of one hundred and three participants with 103 hepatic observations (mean size, 28.2 ± 24.5 mm; HCCs [n = 79], non-HCC malignancies [n = 15], benign [n = 9]; diagnosed by pathology [n = 57], or noninvasive method [n = 46]) were included in this study. The participants underwent CEUS with sulfur hexafluoride. Arterial phase hyperenhancement (APHE) and washout on Gd-EOB-MRI and CEUS were evaluated. The distinctive washout in CEUS was defined as mild washout 60 seconds after contrast injection. The diagnostic ability of Gd-EOB-MRI and of CEUS as a second-line modality for HCC were determined according to the European Association for the Study of the Liver (EASL) and the Korean Liver Cancer Association and National Cancer Center (KLCA-NCC) guidelines. The diagnostic abilities of both imaging modalities were compared using the McNemar's test. Results: The sensitivity of CEUS (60.8%) was lower than that of Gd-EOB-MRI (72.2%, p = 0.06 by EASL; 86.1%, p < 0.01 by KLCA-NCC); however, the specificity was 100%. By performing CEUS on the inconclusive observations in Gd-EOB-MRI, HCCs without APHE (n = 10) or washout (n = 12) on Gd-EOB-MRI further presented APHE (80.0%, 8/10) or distinctive washout (66.7%, 8/12) on CEUS, and more HCCs were diagnosed than with Gd-EOB-MRI alone (sensitivity: 72.2% vs. 83.5% by EASL, p < 0.01; 86.1% vs. 91.1% by KCLA-NCC, p = 0.04). There were no false-positive cases for HCC on CEUS. Conclusion: The addition of CEUS to Gd-EOB-MRI as a second-line diagnostic modality increases the frequency of HCC diagnosis without changing the specificities.

• 한국학교보건학회지
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• 제27권3호
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• pp.189-195
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• 2014

Purpose: This survey was to investigate the differences in smartphone addiction symptoms by the level of addiction among college students in S. Korea. Methods: Two hundred and thirteen university students survey data was collected from December 5th to 9th of 2011 using Smartphone Addiction Scale. 25.3% (n=54) of total respondents were categorized as highly addicted and 28.17% (n=60) were as non-addicted group. Results: There were significant differences in total addiction symptom scores, daily life disorders, loss of self control, pathological concentration, and compulsive symptoms between two groups. There were significantly differences in total addiction symptoms, daily life disorders, loss of self control, pathological concentration, and compulsive symptoms between two groups. Highly addicted group were significantly higher in total addiction symptom scores (3.26 times), daily life disorders (4.96 times), loss of self control (3.07 times), pathological concentration (3.07 times), and compulsive symptoms (2.86 times) compared to non-addicted one. Highly addicted group had significantly higher daily usages of smartphone and were more satisfied with smartphone than non-addicted group. The purpose to use was related to academic works rather than games or entertainment. However satisfaction on academic achievement was very low. Conclusion: The smartphone addicted symptoms related to academic works were significantly high in highly addicted college students so that it disturbed their daily life and psycho-social health in general. It is clear that the highly addicted college students need urgent distinctive interventions such as creative academic guides.

• 디지털융복합연구
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• 제18권2호
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• pp.183-195
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• 2020

커뮤니케이션에서 중요한 비중을 차지하는 비언어적 요소들이 소셜미디어에 있어서도 그 활용성이 높아지고 있다. 본 연구에서는 페이스북 이용자들을 대상으로 Q 방법론을 통해 비언어적 요소들을 활용하는 주관적 인식 유형들을 찾아냈다. 우선 포커스 그룹 인터뷰를 시행하여 소셜미디어의 비언어적 요소들을 대표하는 34개의 Q 진술문들을 도출하였다. 페이스북 이용자들 19명을 대상으로 Q 소팅을 시행한 결과 비언어적 요소들을 서로 다르게 활용하는 3개의 그룹들을 대별할 수 있었다: 안전거리형, 은둔관조형, 전력투구형. 각각의 유형별로 현재 활용하는 비언어적 요소들과 미래에 필요할 것으로 보이는 비언어적 요소를 지원하기 위한 시스템의 기능들에 관해서 논의했다. 본 연구의 결과는 향후 온라인에서의 비언어적 요소나 기능들을 확장하기 위한 기초가 될 수 있을 것이다.

• 한국문헌정보학회지
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• 제50권1호
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• pp.417-435
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• 2016

적합성 평가는 검색효율을 향상시키는데 있어서 중요한 요소이다. 또한 이미지의 검색과 이용이 인터넷과 디지털 정보기술의 발달로 인해 보편화되었음에도 불구하고 이미지 적합성 평가에 관한 연구는 미미한 상황이다. 본 연구는 이미지 검색 실패 사례에 나타난 비적합성 평가요소를 규명하고 특성을 살펴보고자 하였다. 이를 위해서 총 135명의 대학생이 연구에 참여하였으며, 1,452건의 평가요소가 분석의 대상이 되었다. 기존의 연구에서 밝힌 평가요소를 포함하여 본 연구는 13종의 평가요소를 규명하였으며, 전체적으로 '주제적합성', '구성', '정확성', '시각적특성', '완전성', '심미적요소', '구도', '서지적요소', '인상', '자세', '얼굴특성', '새로움', '시대배경' 순의 비중으로 나타났다. 이중에서 '구성'과 '구도'는 본 연구에서 특징적으로 새롭게 규명한 평가요소이며, 기존의 연구에서 밝힌 '행동' 평가요소는 본 연구 데이터에서는 찾아볼 수 없었다. 또한 이러한 평가요소의 비중은 이용자가 지닌 이미지요구와 이용목적의 특성에 따라서 차이를 보였다.

• ETRI Journal
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• 제36권3호
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• pp.514-517
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• 2014

In this paper, alternative dynamic features for speech recognition are proposed. The goal of this work is to improve speech recognition accuracy by deriving the representation of distinctive dynamic characteristics from a speech spectrum. This work was inspired by two temporal dynamics of a speech signal. One is the highly non-stationary nature of speech, and the other is the inter-frame change of a speech spectrum. We adopt the use of a sub-frame spectrum analyzer to capture very rapid spectral changes within a speech analysis frame. In addition, we attempt to measure spectral fluctuations of a more complex manner as opposed to traditional dynamic features such as delta or double-delta. To evaluate the proposed features, speech recognition tests over smartphone environments were conducted. The experimental results show that the feature streams simply combined with the proposed features are effective for an improvement in the recognition accuracy of a hidden Markov model-based speech recognizer.

• 대한세포병리학회지
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• 제9권1호
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• pp.95-98
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• 1998

Papillary renal cell carcinoma (RCC) is an uncommon subtype of RCC that has distinctive gross, histologic, and cytogenetic features. The cytologic features of FNA are abundant papillary clusters and relatively few single cells. The cells are usually small and contain uniform nuclei; numerous macrophages with foamy cytoplasm are often found in the background. We describe a case of papillary renal cell carcinoma evaluated by fine needle aspiration cytology(FNAC) in a 42 year-old man. The smear showed a few papillary clusters and numerous macrophages with foamy cytoplasm in the background. With adequate cellularity, papillary RCC can be distinguished reliably from non-papillary RCC by FNAC.

• 미생물학회지
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• 제30권3호
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• pp.177-180
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• 1992

Among 120 U. maydis strains isolated in Korea 14 different strains containing specific viral dsRNA segments were analyzed for the distribution of dsRNA and the production of toxin protein. Several distinctive dsRNA patterns were identified, 9 cases of P type with typical H, M and L ds RNA and one case of non-P-type, the frequency of a specific isolate was decreased with increasing number of dsRNA segments. The presence of dsRNA had no effect on the cultural or morphological phenotype of the host. Two isolates containing P type dsRNA segments appeared to produce toxin protein (killer strains) which inhibited the growth of 4 isolates (sensitive strain) with different susceptibility. Two killer strains contain unique M dsRNA segment which may code for toxin protein. However, the presence of toxin-sensitive strains among dsRNA-free isolates was similar to that of ds RNA containing strains.

• 한국임상수의학회지
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• 제18권2호
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• pp.152-155
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• 2001

A two-year-old male peacock (Pavo cristatus) showed acute watery green diarrhea, followed by neurological signs including torticollis and muscular tremor. By the hemagglutination inhibition test for detecting the antibody against the Newcastle disease virus (NDV), the peacock serum inhibited the agglutination of chicken red blood cells. Grossly distinctive hemorrhagic lesions were found in the mucosa of proventiculus and intestine and lung. The spleen revealed multiple variable sized necrotic foci. Histologically, the mucosa of gastrointestinal track had hemorrhagic lesions and some of them underwent ulceration. The spleen exhibited multiple variable sized necrotic foci in which fibrin exudation was marked. Central nervous system had mild non-suppulative menin-goencephalitis consisting of vasculitis, perivascular hemorrhage, gliosis and meningitis. The cells particularly in the cerebellum were degenerative to necrotic. Some of these nerve cells revealed characteristic peripheral chromatolysis. From the present serological and pathological findings, it is suggested that NDV causing death of peacock was velogenic viscerotropic strain. This is the first report of the occurrence of velogenic viscerotropic NDV in an adult peacock in Korea.