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        검색결과 2,006

        241.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The electrical resistances of small-sized activated carbon fiber (ACF) fabric (specific surface area: 1244.7 m2/ g, average pore diameter: 1.92 nm) and felt (specific surface area: 1321.2 m2/ g, average pore diameter: 2.21 nm) sensors were measured in a temperature and humidity controlled gas chamber by CO2 adsorption at different surrounding CO2 concentrations (3000–10,000 ppm). The electrical resistances of ACF sensors decreased linearly as the increase of temperature and decreased exponentially as the increase of humidity in the ambient atmospheric chamber. The electrical resistances of ACF rapidly decreased within 4 s and an equilibrium state was achieved within 10 s due to the very rapid CO2 adsorption at room temperature and 40% humidity. Comparing the difference in electrical resistance values measured during injection of similar concentrations of CO2 after reaching the equilibrium value, the fabric exhibited a significant change, whereas the felt did not, even though it had a relatively larger specific surface area. The reason is that micropore volume greatly affected the amount of CO2 adsorbed, whereas the specific surface area did not affect it as much. Therefore, ACF fabric with large micropores (> 2.0 nm) can be developed and used as CO2 sensors in small rooms such as a passenger vehicles.
        4,000원
        242.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To improve the pyrolytic carbon (PyC) deposition rate of Carbon/Carbon (C/C) composites prepared by the traditional chemical vapor infiltration (CVI) method, the 3D Ni/wood-carbon (3D Ni/C) catalyst was introduced into the CVI process. The effects of catalyst on the density of C/C composites were studied, and the deposition rate and morphologies of PyC were investigated after catalytic CVI. The morphologies of catalyst and PyC were characterized by scanning electron microscope and polarized light microscopy. The catalytic deposition mechanism of PyC was studied by density functional theory. The experimental results show that the initial carbon deposition efficiency of the catalytic pyrolysis process was 3–4 times that of the noncatalytic process. The catalyst reduced the energy barrier in the first step of deposition reaction from 382.55 to 171.67 kJ/mol according to simulation results. The pyrolysis reaction energy with Ni catalyst is reduced by 54% than that without the catalyst.
        4,000원
        243.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fluorescent nanostructures based on carbon, or carbon dots, are attracting much attention and interest because of their diverse properties which can be applied in several fields of knowledge, such as optics, biomedicine, environmental research, among others. Such properties are in part, derived from its intrinsic luminescence from tunable functional groups. In this work, we produced carbon nanodots (CND) using agro-industrial residues, such as Lolium perenne and malt bagasse. The methods used were conventional hydrothermal syntheses and microwave-assisted hydrothermal synthesis. To the best of our knowledge, this is the first time that carbon dots synthesized from this ryegrass type are reported. The synthesis methods were one step (no catalyst, base, or acid were added for passivation), and the functional groups responsible for the luminescence and high solubility in water were identified by infrared spectroscopy, being mainly C=O, C–OH, C–N, and N–H. According to our theoretical studies, the C=O group introduced a new energy level for electronic transitions that can affect the emission properties. Fluorescence images of osteoblasts using CNDs were acquired and their chelating property towards Pb2+ and Cr6+ detection was tested.
        4,200원
        244.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 국내산 돌미나리에서 GABA생성능이 있 는 신규 유산균을 분리, 동정한 결과, Enteroccoccus casseliflavus로 확인되었다. 최근까지 Lactobacillus속과 같 은 GABA 생성 유산균에 대한 보고는 많이 되고 있고, 일 부 Enterococcs속 유산균도 보고되고 있으나 E. casseliflavus 종에 대한 보고는 없었다. 따라서 본 연구에서는 E. casseliflavus PL05 균주에 대한 GABA 생성 최적 조건을 찾기 위하여 배지의 유형, 생육 온도, 초기 pH 조건, 배양 시간, MGS 농도 및 탄소원을 포함한 다양한 조건을 테스 트하였다. PL05 균주는 MRS 혹은 TSB 배지보다 BHI 배 지에서 생육이 잘 되었으며, 배지의 초기 pH는 7-9 조건 에서 가장 생육이 왕성하였고, GABA 생성 조건 역시 유 사한 결과로 확인되었다. GABA의 기질에 해당하는 MSG 의 농도별 GABA 생성량을 조사한 결과, 7%에서 가장 높 은 생성량을 나타내었으나 5%에서도 유사한 수준으로 확 인되어 효율적인 측면에서 5%가 적합할 것으로 판단된다. 탄소원에 따른 생육 및 GABA 생성량은 말토오스를 사용 하였을 때 가장 높은 것으로 확인되었고, 이러한 최적의 조건들로 최종 테스트를 진행한 결과, 24시간째 140.06±0.71 mM의 GABA가 생성되었고, 전환율은 78.95%로 확인되 었다. 또한 반코마이신을 포함한 10개의 항생제에 대한 감 수성을 조사한 결과 내성이 없는 것을 확인하였다.
        4,000원
        246.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A cat who is a 15-year-old and spayed female visited an animal clinic with severe coughing symptoms. Since the cat’s coughing symptoms had worsened from the age of 10 and X-rays showed a bronchial pattern in the lungs, it was diagnosed as Chronic Obstructive Pulmonary Disease (COPD). She received three injections of stem cells isolated from the amniotic membrane on days 0, 7, and 23. Although there was no improvement in the clinical findings on the x-ray, the number of coughing was significantly reduced. In addition, even after long-term follow-up post treatment for a month, she was stable with almost no coughing.
        3,000원
        247.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study attempted to determine the characteristic features of postpartum dairy cows during their return to estrus. Moreover, it investigated the effects of abnormal ovarian cycles (AOC) on subsequent reproductive performance and the relationship between normal ovarian cycles (NOC) and the blood urea nitrogen (BUN) level postpartum. Incidentally, 56.3% of the Holstein cows and 66.7% of the Jersey cows had NOC, whereas the 43.7% and 33.3% of the Holstein and Jersey, respectively, had AOC. Within 100 days of calving, the cows with AOC had significantly lower rates of artificial insemination (AI) submission as well as pregnancy and a significantly longer interval to first AI, as compared to that in the cows with NOC. Additionally, the cows with NOC had a significantly higher first AI conception rate than that in the cows with AOC. In this study, of the 32 Holstein cows, 8 resumed their ovarian cycle within 20 days of calving, 10 resumed the cycle with 21-40 days of calving, 8 within 41-60 days of calving, while the remaining 6 did not resume their ovarian cycles until 60 days postpartum. Furthermore, the likelihood ratios of incidence of NOC are 0.93, 1.94, and 0.38, respectively, in the groups with BUN levels < 15, 15-19.9, and ≥ 20 mg/ dl. In conclusion, AOC postpartum adversely affects reproductive performance such as AI submission rate, pregnancy rate, interval to first AI and first AI conception rate; moreover, an increase or decrease in the BUN levels beyond 15-19.9 mg/dL leads to the AOC postpartum.
        4,000원
        248.
        2021.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        A 5-year-old female fennec fox weighing 1 kg presented to the Veterinary Medical Center, Chungbuk National University with swelling of the mammary glands and hematuria. There were no significant complete blood count (CBC) or serum chemistry findings. The uterus obtained by ovariohysterectomy was filled with blood-clot-like material. The uterine fluid contained erythrocytes, a few leukocytes, and bilirubin crystals without bacteria. The progesterone concentration in the blood serum the day before ovariohysterectomy was 7.3 ng/ mL, which is higher than anestrus and lower than a true pregnant condition in a fennec fox. Despite the low blood progesterone concentration and absence of a fetus in the uterus, the histopathological zonary placental findings indicated that the fennec fox had been pregnant. This is the first case report of hematometra associated with fetal death in a captive fennec fox.
        4,000원
        249.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the effect of a synthetic complement peptide C3a on the outcome of Brucella abortus 544 infection in a murine macrophage cell line RAW264.7 cell. First, we determined the highest non-cytotoxic concentration of the peptide in the cell line. We also found that the peptide significantly increased the growth of the bacteria at 8 and 24 h. Although the number of bacterial CFU was also elevated at 48 and 72 h, the increases were not significant as compared to controls. We further investigated the effect of C3a peptide on the growth of Brucella by pre-incubating the peptide at various temperatures and found that the effect was reversed at 24 h post-incubation suggesting that incubation of peptide at high temperatures including 65°C or 95°C could inactivate its action. This also could indicate the beneficial effect of high temperature during infection. Although several studies reported the inhibitory effect of different antimicrobial peptides including C3a, the present study preliminarily revealed that it had no positive contribution on the control of B. abortus 544 infection in vitro and indirectly to its receptor, CD88, which belongs to GPCR. Moreover, the encouraged further exploration of the effect of other similar peptides would be performed for the purpose of finding Brucella-host cell interaction for the control of disease progression.
        4,000원
        250.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to investigate the effects of exogenous succinic acid (SCA) on Brucella (B.) abortus infection in macrophage RAW 264.7 cells and ICR mice. Firstly, the in vitro experiment was conducted by MTT cytotoxicity and bacterial internalization assay to evaluate the uptake of B. abortus into macrophage cells. Two non-cytotoxic concentrations of SCA demonstrated attenuated invasion of Brucella into macrophages at 30 and 45 min post- infection (pi). Secondly, ICR mice were treated with SCA and infected with B. abortus. On day-14 pi, spleen and blood serum were collected to evaluate the bacterial burden and total spleen weight as well as the production of cytokine/chemokine, respectively. The results showed that SCA treatment promoted bacterial growth and reduced the total spleen weight in mice. Furthermore, SCA treatment increased the level of IL-10 cytokine in the sera, while dampening the production of MCP-1 chemokine compared to the control. The results of bacterial load in spleen and spleen weight together with cytokine/chemokine production profile in the sera indicated that SCA induced the host anti-inflammatory response which is beneficial for the survival of Brucella. Therefore, these findings suggest that SCA contributed to host immunity against Brucella infection and the emerging potential topic-immunometabolism should be invested for further investigations.
        4,000원
        251.
        2021.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The natural relics excavated from the archeological site reveal the life, hunting, fishing, and gathering of mankind at the time, and the animal bones excavated from the remains become valuable data for the study of geography and bone diseases at the time. This study investigated the morphological structure, size, and osteometry of Sus scrofa bones excavated from the well area of the Gasan-Ri archaeological site in Jinju, presumed to be a relic of the Three Kingdoms period. The total weight of identified animal bones was 975.30 g and the number of bone fragments was 447. Among these 447 animal bones identified, the bone weight of Sus scrofa was 468.00 g (47.99%) and the number of bone fragments was 204 (45.64%). These 204 bone fragments of Sus scrofa consisted of 35 skulls (17.16%), 94 vertebrate axial skeletons (46.08%), 28 forelimb bones (13.73%), and 47 hindlimb bones (23.04%). The bones of Sus scrofa have been identified as those of two animals. The estimated age of these bones of Sus scrofa was 5-7 weeks. There was a fracture presumably caused by an artificial blow to the parietal bone located near the bregma in the skull.
        4,000원
        252.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        뇌 3차원 T1 관상면 검사 시 ENCASE를 적용했을 때 CS 계수의 증가 시 영상획득 시간 변화와 영상의 질의 변화에 따른 유용성에 관하여 알아보고자 한다. 연구 대상은 본원을 내원한 30명의 환자를 대상으로 하였고, 1.5T MRI 장치로 진행하였으며, 24채널 두경부 코일을 사용하였다. 획득한 영상의 상대적신호강도비(rSI)와 상대적대조도비(rC)를 구하였으 며, MIPAV로 뇌실질과 뇌실의 체적을 측정하여 One-way Anova를 사용하여 정량적 분석을 하였고, p<0.05일 때 통계 적으로 유의한 것으로 해석하였다. 또한, 5점 리커트 척도를 이용하여 영상의 질에 대하여 정성적 분석을 하였고, 측정자 내 신뢰도를 확인하기 위해 ICC가 0.75 이상 나오면 측정자간 신뢰성이 높은 것으로 간주하였다. rSI와 rC 모두 p<0.05로 통계적으로 유의미한 차이를 보였고, 급내 상관계수가 0.75이상(p<0.05)으로 통계적으로 매우 높은 신뢰도를 나타냈다. MIPAV를 이용한 체적측정에서는 뇌실질과 뇌실의 체적의 차이는 p=1.000으로 통계학적으로 유의미한 차이는 없었고, 사후분석결과 또한 유의미한 차이를 보이지 않았으며. 급내 상관계수가 0.75이상(p<0.05)으로 통계적으로 매우 높은 신뢰도를 나타냈다. 또한, 정성적 평가에서는 CS 계수가 증가함에 따라 유의미한 차이가 있는 것으로 나타났다(p<0.001). 따라 서 ENCASE 기법을 이용한 3차원 T1 TFE 관상면 검사 시 CS 계수를 증가시킨다면 뇌의 체적 변화 없이 3차원 T1 시상면 영상보다 짧은 150초로 기존의 뇌 3차원 시상면 T1 기본 검사시간 260초 보다 짧은 영상획득 시간으로 진단적 가치가 높은 영상을 제공할 수 있을 것으로 사료된다.
        4,000원
        253.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pantala flavescens is a dominant Odonata species in the rice fields in Korea. To determine the effects of different temperatures on its larval growth and emergence, field and laboratory experiments were conducted. Larval growth was also monitored in mono-cropping and double-cropping rice fields. The growth of larvae was monitored every week by measuring the head width. In the field experiment, no difference was found in larval growth and emergence between the control temperature and +1.9°C of the control temperature. The larval growth was greater at 23°C than at 20°C laboratory temperatures, and no emergence was recorded at either temperature after eight weeks of monitoring. There was a quadratic relationship between larval growth and temperature in an incubator at five temperature regimes of 15, 20, 25, 30, and 35°C. Midseason water drainage caused the extinction of the existing individuals and newly hatched larvae dominated after re-watering in the rice fields. Larval size was greater in double-cropping fields than in mono-cropping fields in late July but the tendency was reversed in early August. The results of this study suggest that temperature warming will directly promote the larval growth of P. flavescens and indirectly influence seasonal growth via changes in water management in rice fields.
        4,000원
        254.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 거베라 주산지인 경북과 경남 지역의 농가 재배 및 스마트팜 현황을 조사하고 분석하고자 수행하였다. 조사방법은 2020년 81 농가를 대상으로 대면 설문조사를 실시하였다. 거베라 경영주 연령은 50∼60대가 71.6%로 가장 많았고, 30∼ 40대가 16%, 70세 이상이 9.9%, 30세 이하는 2.5% 순이었다. 거베라 재배 경력은 5년 이하가 37%였으며, 6∼10년 25.9%, 11∼20년 29.6%, 21년 이상 농가가 7.4%였다. 재배 면적은 0.3 ∼0.6ha가 61.7%로 가장 많았고, 0.3ha 미만이 30.9%, 0.6ha 이상이 7.4%였으며, 전체 평균재배 면적은 0.37ha였다. 거베라 재배 농가당 평균 인력은 자가 노동력 2.1명, 고용 노동력 0.8명 이었다. 재배 방식에서 토경 88.9%, 양액재배 농가는 11.1%였다. 국산품종을 전체 또는 일부라도 재배하고 있는 농가는 61.7%였고 외국산 거베라 품종만 재배하고 있는 농가는 38.3% 였다. 거베라 병해충 발생조사에서 병 발생이 많았다고 응답한 농가는 91.4%였으며, 충 발생이 많았다고 응답한 농가는 98.8% 였다. 스마트팜 시스템을 설치한 농가는 12.3%였으며, 설치하지 않은 농가에서 향후 설치할 의향이 있다고 응답한 농가는 76.9% 였다. 향후 경영계획을 묻는 질문에서 현상유지 80.2%, 축소 8.6%, 경영확대 11.1%였으며, 경영 확대를 대답한 농가는 경북 지역이 8농가로 경남지역 1농가 보다 많았다.
        4,000원
        255.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As Deepfakes phenomenon is spreading worldwide mainly through videos in web platforms and it is urgent to address the issue on time. More recently, researchers have extensively discussed deepfake video datasets. However, it has been pointed out that the existing Deepfake datasets do not properly reflect the potential threat and realism due to various limitations. Although there is a need for research that establishes an agreed-upon concept for high-quality datasets or suggests evaluation criterion, there are still handful studies which examined it to-date. Therefore, this study focused on the development of the evaluation criterion for the Deepfake video dataset. In this study, the fitness of the Deepfake dataset was presented and evaluation criterions were derived through the review of previous studies. AHP structuralization and analysis were performed to advance the evaluation criterion. The results showed that Facial Expression, Validation, and Data Characteristics are important determinants of data quality. This is interpreted as a result that reflects the importance of minimizing defects and presenting results based on scientific methods when evaluating quality. This study has implications in that it suggests the fitness and evaluation criterion of the Deepfake dataset. Since the evaluation criterion presented in this study was derived based on the items considered in previous studies, it is thought that all evaluation criterions will be effective for quality improvement. It is also expected to be used as criteria for selecting an appropriate deefake dataset or as a reference for designing a Deepfake data benchmark. This study could not apply the presented evaluation criterion to existing Deepfake datasets. In future research, the proposed evaluation criterion will be applied to existing datasets to evaluate the strengths and weaknesses of each dataset, and to consider what implications there will be when used in Deepfake research.
        4,800원
        256.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고치벌과에 속하는 Microgastrinae 아과의 Diolcogaster perniciosa (넓적다리도랑꼬마고치벌)을 한국에서 처음으로 보고한다. 본 종의 재기 재, 진단, 분포정보, 그리고 삽화를 제공한다.
        3,000원
        257.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 포장 및 실험실 조사를 통해 자두수염잎벌(Monocellicampa pruni Wei, 1998)의 생활사를 확인하였다. 자두수염잎벌은 5령의 유충 단계를 가지는 일화성 곤충이다. 성충은 자두가 만개하는 3월 중순경에 흙에서 나와 꽃받침의 표피층 밑에 1개(드물게 2개)의 알을 낳는다. 부화 후, 유충은 곧 어린 과실 속으로 파고들어 성충이 되기 전 4번의 탈피 과정 동안 과실 안에서 과육을 섭식한다. 유충이 성숙하면(5월) 과실에서 나와 2 - 11 cm깊이의 땅속으로 파고 들어가 번데기방을 만들고 이듬해 봄까지 전용 형태로 월동한다. 실험실 조건(T = 20°C, RH = 40 - 60%)에서 수컷 성충의 생존기간은 암컷성충보다 약간 짧았고(수컷 6.03 ± 0.40일 및 암컷 7.55 ± 0.45일), 암컷은 평생 30.29 ± 4.50개의 알았다. 포장에서 알기간은 약 10 - 11일이었고, 유충기간은 약 31 - 34일이었다.
        4,000원