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        검색결과 24

        1.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted as part of a series of studies to introduce the Convolutional Neural Network(CNN) into the diagnostic field of osteoporosis. The purpose of this study was to compare the results when testing Digital Radiography(DR) and Computed Radiography(CR) panoramic radiographs by CNN that were trained by DR panoramic radiographs. The digital panoramic radiographs of females who visited for the purpose of diagnosis and treatment at Chonnam National University Dental Hospital were taken. Two Oral and Maxillofacial Radiologists were selected for the study to compare the panoramic radiographs with normal and osteoporosis images. Among them, 1068 panoramic radiographs of females{Mean [± standard deviation] age: 49.19 ± 21.91 years} obtained by DR method were used for training of CNN. 200 panoramic radiographs of females{Mean [± standard deviation] age: 63.95 ± 6.45 years} obtained by DR method and 202 panoramic radiographs of females{Mean [± standard deviation] age: 62.00 ± 6.86 years} obtained by CR method were used for testing of CNN. When the DR panoramic radiographs were tested, the Accuracy was 92.5%. When the CR panoramic radiographs were tested, the Accuracy was 76.2%. It can be seen that the CNN trained by DR panoramic radiographs is suitable to be tested with the same DR panoramic radiographs.
        4,000원
        2.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cryopreservation is mainly used for preservation of boar sperm. However, this method stresses the sperm by reactive oxygen species (ROS), and the conception rate and the litter size are not more efficient than the liquid preservation of spermatozoa. Therefore, we use chitosan which is a natural product derived antioxidant compound. We used GnHA (chitosan+hyaluronic acid) and GnHG (chitosan hydrogel) as chitosan complexes to cryopreserve boar sperm for improve sperm metabolism and function. Sperm parameter (sperm motility, progressive motility, path velocity, straight-line velocity, curvilinear velocity) is measured by computer-assisted sperm analysis (CASA) using frozen sperm with GnHA or GnHG (0, 0.25, 0.5, 1 mg/mL), respectively. Also, lipid peroxidation analysis using malondialdehyde (MDA) is performed to confirm the antioxidative effect of chitosan in frozen spermatozoa. CASA analysis showed GnHA and GnHG are effective against cryopreserved boar sperm. And antioxidant effect is measured by lipid peroxidation analysis. GnHA and GnHG, which is chitosan complex are effective for boar sperm cryopreservation by antioxidant effect.
        4,000원
        3.
        2018.11 구독 인증기관·개인회원 무료
        Cryopreservation is mainly used for preservation of boar sperm. However, this method stresses the sperm by reactive oxygen species (ROS), and the conception rate and the litter size are not more efficient than the liquid preservation of spermatozoa. Therefore, we use chitosan which is a natural product derived antioxidant compound. We used GnHA and GnHG as chitosan complexes to cryopreserve boar sperm for improve sperm metabolism and function. Sperm parameter (sperm motility, progressive motility, path velocity, straight-line velocity, curvilinear velocity) is measured by computer-assisted sperm analysis (CASA) using frozen sperm with GnHA or GnHG (0, 0.25, 0.5, 1 mg/mL). Also, lipid peroxidation analysis using malondialdehyde (MDA) is performed to confirm the antioxidative effect of chitosan in frozen spermatozoa. Sperm motility was higher in GnHA 0.25 mg/mL and GnHG 0.5 mg/mL compared to control. In addition, GnHG 0.5 mg/mL was significantly decreased in lipid peroxidation analysis. The results suggest that GnHA and GnHG are effective for boar sperm cryopreservation by antioxidant effect.
        4.
        2018.10 구독 인증기관·개인회원 무료
        반초원의 식생이 훼손된 중국 내몽골의 간주얼 지역에서 인위적인 식물의 도입에 의하여 서로 다른 연도에 복원된 식물군락의 천이와 토양의 특성 변화를 조사하였다. 간주얼 지역의 식물군집(식피율, 식물 수고와 식물 종다양성(종수)등)의 결과들은 복원지소들이 비복원지보다 높게 나타났지만, 주변의 정상적인 대조지소들보다는 낮은 값을 보였다. 이러한 결과는 이 지역에서 생태복원으로 인하여 생태계의 구성요소가 꾸준하게 발전하고 있음을 뜻한다. 복원이 가장 오래된 2005년 지소의 경우, 식물종구성이 유사한 대조지 사이트인 초지지역의 것들과 식피율이나 식생고가 유사한 결과들을 보여 복원의 효과를 긍정적 볼 수 있으나, 식물다 양성 측면에서는 아직 대조지 초지의 것보다 높지 않았다. 2017년의 경우, 2014년 조사 시작 이래 가장 많은 종들이 고사하여 주요 우점종들의 생육이 불안정한 상태를 가시적으로도 확인할 수 있는 정도로 현지조사의 결과들이 이를 반영하고 있다. 2008년 복원지 장자송의 소지생존 성장률은 47%로 작년(100%)보다 낮아졌으며, 조사대상인 20개체 중 5개체가 고사하였다. 군락 내 식생고(식물체높이)의 결과에서는 복원지들이 모두 낮아진 결과를 보였는데, 이는 장자송, 캐나다포플러 등 주요 우점종들이 고사하여 나타난 결과이다. 이렇게 많은 식물이 고사함에도 불구하고 하층에 살아 남아 생존하는 동일수종 및 다른 식물종들은 경쟁상대가 줄어들면서 오히려 더 활력이 좋아지는 결과를 나타내기도 하였다. 이러한 결과는 복원지에서 정착된 식생의 발달은 진행 중이나 그 항목에 따라서 외부의 물리적인 환경(가뭄 등)과 같은 요인에 의하여 영향을 크게 받고 있음을 의미 한다. 식생군락과 환경요인과의 분석(CCA)결과는 비생육기 온도(11월~2월), 생육기온도(6월~8월), 토양유기물, TN, 유효인산 그리고 산화칼륨이 영향을 주는 외부의 주요 비생물학적 환경인자로 나타났다.
        5.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With the advent of mobile technology, teaching and learning have been more effective with the help of smartphone education applications. This study investigates the effects of vocabulary learning using the smartphone education applications on Korean elementary school learners’ English vocabulary learning and attitudes. A total of fifty-seven elementary school students in the 5th grade participated in the study and were randomly divided into an experimental and a control group. The results of the study manifested that both the experimental and control group showed an increase in the comprehension and production score from pre- to post-tests. The effects of the long-term vocabulary learning, however, were not found to be statistically significant. The average score in the delayed test for both groups slightly increased, which indicated that the treatment was beneficial for learners’ long-term memory enhancement. In the affective domain, interests and confidence ratings were significant for the upper-level experimental and lower-level control group. The results of the survey questionnaire showed that the vocabulary learning using direct examples and pictures for both groups was helpful to improve learners’ lexical competence.
        6,400원
        6.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this experiment, we determined the effect of curcumin supplementation in freezing buffer for miniature pig sperm cryopreservation. Each ejaculate was diluted with modified Modena B extender and mixed with lactose-egg yolk (LEY extender, 80% v/v lactose solution [310 mM], 20% v/v egg yolk, and100 μg/mL kanamycin sulfate) and LEY-glycerol Orvus ES Paste (LEYGO, 89.5% v/v LEY, 5% v/v glycerol, 1.5% v/v Orvus ES Paste), 100 mM trehalose supplemented with 0, 10, 50, 100, and 500 μM of curcumin from turmeric, respectively. Following equilibration, the 0.5 mL French straws were frozen and plunged into LN2 tank for 7 days at least. Sperm parameter and oxidative byproducts were determined by the computer assisted sperm motility analysis (CASA) and fluorescence-activated cell sorting (FACS) as compared with each groups.Supplementation of curcumin had no effect on sperm motility, progressive motility and curvilinear velocity. However, average-path velocity and straight-line velocity were significantly higher in 10 μM curcumin group (100.9±8.8 μm/s, 61.7±2.9 μm/s, respectively) than control group (77.8±3.9 μm/s, 46.4±3.0 μm/s, respectively) (p < 0.05). In addition, the level of the O2 radical and H2O2 were comparatively decreased in curcumin groups by evaluation of ethidium and DCF fluorescence. According to the results, curcumin can improve sperm kinetic variables and alleviate ROS induced cryoinjury to pig sperm.
        4,000원
        7.
        2016.06 구독 인증기관 무료, 개인회원 유료
        Tooth development shows dynamic morphological changes from the stages of cap to hard tissue formation and is strictly regulated during development. In the present study, we compared expression and localization of 3 major enamel matrix proteins in rats: amelogenin, enamel and ameloblastin. DD-PCR and RT-PCR revealed differential expression of the major proteins from the cap stage to root stage. Immunofluorescence staining results indicated that amelogenin was not detected in either inner enamel epithelium or reduced enamel epithelium, but highly immunoreactive in preameloblasts and ameloblasts; in addition, it was sporadically expressed in preodontoblasts abutting preameloblasts. Ameloblastin expression was also observed in not only differentiated ameloblasts but also osteoblasts. Immunoreactivity to ameloblastin in ameloblasts was strong in Tomes' processes. Enamelin was exclusively localized along the entire newly formed and maturing enamel. Enamelin was largely localized in near Tomes' processes and enamel rods in maturing enamel. Alendronate treatment resulted in down-regulation of amelogenin and ameloblastin at both transcription and translation levels; whereas, enamelin expression was unchanged in response to the treatment. These results suggested that amelogenin, ameloblastin and enamelin might be implicated in cell differentiation, adhesion of ameloblasts to enamel and enamel crystallization during enamel matrix formation, respectively.
        4,000원
        8.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 2009년부터 2011년 까지 6년간 경남지방 도축장에서 도축한 한우 63,388두에 대한 도 축성적 자료를 근거로 하여 한우의 경락단가 결정에서 있어 가장 큰 영향을 미친다고 생각되는 등지방 두께, 등심단면적, 도체중 및 근내지방도가 경락가격에 영향을 미치는 기여도를 분석하기 위하여 최소 제곱 평균법으로 SAS @9.3 Package/PC를 이용하여 분석하였으며, 본 연구의 결과를 요약하면 다음과 같다. 각 요인에 대한 분산분석 즉, 유의성 검정 결과 조사한 형질에 대해 성, 도축계절, 도축년도의 효 과에 대해 고도의 유의성(p<0.01)을 나타내었다. 표현형 상관에서 모든 형질간의 정의상관을 확인 할 수 있었으며 경락단가에 대해서는 근내지방도가 가장 높은 0.70의 정의 상관을 나타내었으며, 총 가격 에서는 경락단가를 제외한 도체형질 중에서 도체중이 0.74로 가장 높은 정의 상관을 나타내었다. 요인 별 기여도 분석에서 경락단가에 대한 근내지방도의 기여도는 95.41%로 가장 높게 나타났고, 총가격에 서도 근내지방도가 52.57%로 가장 높았고 다음으로 도체중이 44.31%로 기여도가 높은 것으로 나타났 다. 이상의 연구결과를 통해 한우의 경락단가, 총가격에 대한 요인별 기여도를 산출해낼 수 있었다. 한 우의 경락단가를 높이기 위해서는 근내지방도 위주의 개량이 적합하고 총가격을 위해서는 도체중까지 고려한 개량 및 사양 방법이 필요할 것으로 사료된다. 본 연구는 분석 결과를 통해 경락단가와 총가격 의 기여도를 고려하여 가장 높은 수익을 얻도록 전략적으로 출하시기를 선택하는데 기초자료로 활용하 고자 하며 각 형질들의 환경요인에 따른 분산분석결과를 통해 한우농가 수입증대를 위한 한우 개량 방 향제시를 위한 기초자료로 활용하고자 한다.
        4,000원
        10.
        2015.06 구독 인증기관 무료, 개인회원 유료
        Macrophages play an important role in both the innate and adaptive immune responses. These include phagocytosis, killing of microorganisms, antigen presentation, and induction of immune cytokines and antimicrobial genes. Macrophage activity is reported to be controlled by diverse exogenous antigenic or endogenous metabolic molecules, and the underlying mechanisms are well documented in human and mouse macrophage cells. Bacterial lipopolysaccharide (LPS) is known to be one of the most potent stimuli activating macrophages through the toll like receptor 4 (TLR4) signaling pathway. There are other antigenic molecules, such as muramyl dipeptide (MDP) and outer membrane protein A (OmpA), that are also known to activate immune cells. On the other hand, short chain fatty acids (SCFAs) such as acetate and butyrate are produced by gut microbiota and control host energy metabolism and signal transduction through GPR receptors. However, there are few studies demonstrating the effects of these molecules in macrophages from domestic animals, including domestic pigs. In this study, we attempted to characterize gene expression regulation in porcine macrophages (PoM2, Pig Monocytes clone 2) following treatment with LPS, MDP, OmpA, and two short chain fatty acids using porcine genome microarray and RT-PCR techniques. A number of novel porcine genes, including anti-microbial peptides and others, appeared to be regulated at the transcriptional level. Our study reports novel biomarkers such as SLC37A2, TMEN184C, and LEAP2 that are involved in the porcine immune response to bacterial antigen LPS and two short chain fatty acids.
        4,000원
        11.
        2014.03 구독 인증기관 무료, 개인회원 유료
        We would like to report a case of leiomyoma of the ovaries in a dog. Leiomyoma is commonly seen in the vagina in dogs. However, it is a very rare neoplasm in the ovaries. As there have only been a few reported cases, this report provides valuable information on veterinary medicine and pathology. Masses found in the ovaries need to be differentiated from other ovarian tumors. Therefore, we describe the gross, histopathological, and immunohistochemical features of a case of ovarian leiomyoma in a 10-year-old female Yorkshire Terrier dog. The mass on the right of the uterus was found accidentally by pelvic ultrasonography. Laparatomy revealed a large multi-nodulated ovarian mass. Grossly, cut surfaces of the mass showed multiple firm whitish nodules in the cortex and bloody loose connective tissue in the medulla. Histopathologically, the cortex of the mass was composed of spindle cells forming interlacing fascicles. The cells had elongated, blunt-ended nuclei and eosinophilic cytoplasm as detected by hematoxylin and eosin staining. Immunohistochemical stained sections were immunoreactive for α-smooth muscle actin and desmin but negative for vimentin and S-100. Therefore, differential diagnosis confirmed leiomyoma based on morphology and positive staining for α-smooth muscle actin and desmin.
        3,000원
        12.
        2013.09 구독 인증기관 무료, 개인회원 유료
        We would like to report a case of bovine lymphosarcoma. Parous cattle from a livestock farmhouse were examined for mutinodular masses in the abdominal cavity after slaughter. For clinical signs, animals presented mild leukemic signs but did not have viral or bacterial infection. Grossly, whitish to yellowish smooth masses similar to fat tissue were covered with a thin membrane. A multilobulated mass formed around the arteri, and there was a large quantity of reddish fluid on the cut surface. Histopathologically, a monomor- phic population of lymphocytes was observed along with small amounts of cytoplasm, round nuclei with coarsely granular chromatin, and numerous mitotic figures in the samples. In the tumor lesion, uniformly round cells had invaded with abundant neovascularization. Especially, the immunohistochemical phenotype of tumor cells was posi- tive for anti-CD3 and negative for anti-CD8 and anti-CD20. Therefore, morphological analysis diagnosed the mass as a multinodular bovine lymphosarcoma of T-cell origin with- out any sign of infection by a viral agent.
        3,000원
        13.
        2013.06 구독 인증기관 무료, 개인회원 유료
        Cholangiocarcinoma is a relatively rare neoplasm in animals and humans. A four-year-old, neutered male ferret presented with depression, anorexia, cachexia diarrhea, and icterus. Necropsy findings included ascites multiple white nodules on the surface of the liver, stomach and duodenum, gross enlargement of the bile duct and right atrium, hemorrhage of the gastric and duodena mucosa, and icterus of the mesenteric fat. Infiltrative well differentiated neoplastic biliary epithelial cells forming ducts and acini with a prominent collagenous stroma were observed on microscopic examination of neoplastic lesions within the liver, mesentery, and the serosa of the stomach and duodenum. This is a report on a rare case of obstructive jaundice due to cholangiocarcinoma in a ferret.
        3,000원
        14.
        2013.03 구독 인증기관 무료, 개인회원 유료
        A 14-year-old female South American sea lion (Otaria byronia) with persistent vaginal secretion and chronic hemorrhagic diarrhea was encountered. During postmortem examination, the uterus was found to resemble a balloon with mucosal congestion and was filled with grayish milky material. The ovaries also had abnormal features, including necrotic surface lesions and multiple whitish foci in the cut section. Hemorrhages and ulcerated changes due to toxemia were observed in other organs, including the liver, spleen, lung, intestines, and lymph nodes. Microscopically, the left ovary contained interlacing fascicles of fibroblast-like cells with blunt-end nuclei showing cytoplasmic positive immunoreactivity against alpha-smooth muscle actin and desmin. The right ovary contained cells with round to cigar-shaped nuclei showing cytoplasmic positive immunoreactivity against vimentin. In conclusion, based on classification of bilateral ovarian tumors as a leiomyoma in the left region and a fibroma in the right region, this sea lion was diagnosed with chronic closed pyometra.
        3,000원
        15.
        2012.12 구독 인증기관 무료, 개인회원 유료
        The deleted in colorectal cancer (DCC) protein mediates attractant responses to netrin during axonogenesis. In the rat trigeminal ganglia (TG), axons must extend toward and grow into the trigeminal nerve to innervate target tissues such as dental pulp. Our present study aimed to investigate the exp- ression of DCC in the TG. Four developmental timepoints were assessed in the experiments: postnatal days 0, 7 and 10 and adulthood. RT-PCR and western blotting revealed that the expression of DCC mRNA and protein does not signi- ficantly change throughout development. Immunohistoche- mistry demonstrated that DCC expression in the TG was detectable in the perikarya region of the ganglion cells du- ring development. Nerve injury at 3 and 5 days after the man- dibular nerve had been cut did not induce altered expression of DCC mRNA in the TG. Moreover, DCC-positive cell bodies also showed similar immunoreactive patterns after a nerve cut injury. The results of this study suggest that DCC constituti- vely participates in an axonogenesis attractant in ways other than expression regulation.
        4,000원
        16.
        2012.12 구독 인증기관 무료, 개인회원 유료
        The effects of the an immunosuppressive drug cyclos- porine A (CsA), on the salivary gland are largely unknown, even though clinical trials for the stimulation of salivation using CsA have been attempted. Cyclophilin A (CypA) is known to be a binding protein for CsA. CypA has cell proliferation and tissue matrix change activities. In our present study, the presence of CypA in the gland and effects of CsA on CypA expression were investigated by immu- nohistochemistry, immunoblotting and RT-PCR analyses. CypA was immunohistochemically detected in various kinds of ducts in the submandibular glands of Sprague Dawley rats. The CypA mRNA level was highest at postnatal day 1 and gradually decreased in a time-dependent manner up to adulthood. The expression of CypA increased after a 10 day subcutaneous administration of CsA in postnatal day 1 rats. Surgical sections of the chorda-lingual nerve with impaired salivation showed no changes in CypA expression. A cell proliferation assay using PCNA anti-serum showed inc- reased cell division following CsA treatment. These results suggest that CsA and CypA may act on ductal cells to regulate saliva composition rather than salivation levels.
        4,000원
        17.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate perceptions and globalization of Korean food among university students with food related majors. Self-administer questionnaires were completed by 386 students, and data was analyzed using descriptive statistics, t-test, ANOVA and regression analysis. The students in food-related majors had positive perceptions of Korean food. They had perceptions of Korean foods as ‘fermented foods’, ‘seasonal foods’, and ‘medical foods’ and have ‘various spices’. Most students agreed that Korean foods need to be ‘creatively transformed’ and ‘localized’ in order to globalize successfully. Localization, fusion and creative transformation of Korean food are more important than simple adherence to traditional Korean food. There were statistically significant differences in perception between students in different majors. Students majoring in traditional Korean cuisine showed a more positive perception and attitude toward globalization of Korean food.
        4,000원
        18.
        2009.06 구독 인증기관 무료, 개인회원 유료
        Water resources in Republic of Korea have been mainly supplied by the artificial reservoirs and lakes due to severely unbalanced rainfall. rainfall through the year. The lakes and reservoirs in which littoral zones have been damaged in a dry season usually have a big difference between high and low water level. In this study, We examined the effects of artificial floating island (AFI) in the Lake Baekgoki at Jin-Cheon, Chungcheongbuk-do, Korea. Phytoplankton is flora as 29 genera and 39 species, and the dominant species were Synedra acus, Lyngbya sp. and Cryptomonas sp., etc. The plankton numbers gradually decreased after installation of the AFI. In contrast with the phytoplankton, zooplankton individuals increased under the AFI, offering the habitats for zooplankton. Fish fauna were three families and seven species and 76 individuals were counted the AFI. The artificial vegetated island showed the significant effects on the restoration of lake ecosystem.
        4,000원
        19.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study conducted a comparative analysis of use of evaluative adjectives in the essays of Korean EFL learners and native speakers of English. It discussed the characteristics of different types of evaluative adjectives, e.g., frequency, semantic categories, and collocational value of evaluative adjectives. The result of the frequency analysis demonstrates Korean EFL learners’ significant overuse of the limited types of the target items. The analysis of evaluative adjectives by semantic categories shows the similar tendency. For example, the repeated use of a small number of assessment adjectives resulted in the high frequency of adjectives in the assessment category. The present study also demonstrates the collocational associations between the selected evaluative adjectives and intensifiers in the corpus. The descriptive results of the analysis of collocational information indicate that learners employed a less formal/spoken style in the written corpus. As Blagoeva (2004) noted, the differences between the Korean EFL learners and native speakers of English in the characteristics of evaluative expressions might not directly obstruct communication but it is an indication that there is still much to be done in the development of second/foreign language skills.
        5,500원
        20.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Vocabulary expansion is essential for learners to gain proficiency in L2, but learners’ lexical knowledge has not drawn much research attention in SLA (Howarth, 1996). In an attempt to throw light on a neglected aspect of learners’ competence, this paper investigates the use of a lexical item in the writing corpora. In particular, it compares the frequency and distribution of intensifiers in the EFL corpus with those in a native English corpus. The result of the frequency analysis in the EFL corpus offers an evidence of significant overuse of the limited types of maximizers and boosters, which in turn result in the inflated frequency of intensifiers. Further, the present study uses the mutual information score to measure the strength of the bond between selected intensifiers and adjacent lexical items. The result does not clearly demonstrate associations between the intensifier and the adjacent words due to the small corpus size, but it provides some possible pedagogical implications for L2 teaching. The frequency information rather than the information on the strength of associations between intensifiers and adjacent words, for example, would be more helpful to EFL learners.
        5,700원
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