검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 1,992

        1361.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recurrence-metastasis status of squamous cell carcinoma of tongue is a challenging oncologic problem. This study examined the expression of E-cadherin/β-catenin cell adhesion complex in squamous cell carcinoma of the tongue through an immunohistochemical study. Twenty samples from 15 patients with squamous cell carcinoma of the tongue, who were treated at the Department of Oral and Maxillofacial Surgery, consisted of primary or recurrent tumors along with matched metastatic lymph nodes were retrieved for immunohistochemical staining and grouped based on recurrence-metastasis status.Differences in stain localization were noted in E-cadherin, β–catenin and phospho β–catenin staining between different tumor groups based on the recurrence-metastasis status. The number of phospho β-catenin stain positive cells was found to have a significant role in survival. E-cadherin confirms its role as a powerful individual differentiation indicator and the role of β-catenin specially the phospho type elicts interest
        4,600원
        1362.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        서울 기상 관측소(서울시 종로구 송월동, 37˚34'N, 126˚57'E, 이하 송월)의 일 최저기온과 결빙 자료, 그리고 인근인 한강 관측소(37˚30'N, 126˚57'E, 이하 한강)의 결빙 자료를 사용하여, 1907-2006년(100년) 동안 한국 서울에서의 결빙기후의 장기 변동을 조사하였다. 송월의 결빙은 옥외 노장의 물이 동결하는 현상으로 정의하였고, 이곳에서 6 km 떨어진 한강의 결빙은 한강 대교 남단에서 2번째와 4번째 교각의 상류 100 m 부근이 완전히 얼었을 때로 정의한다. 평균 첫 결빙일은 송월이 10월 28일, 한강이 12월 28일이며, 각각 0.78 days decade-1와 3.47 days decade-1로 점차 늦어지는 추세를 나타냈다. 평균 연 결빙 일수는 송월이 159.06일, 한강이 50.33일이며, 각각 2.01 days decade-1와 5.24 days decade-1로 감소하는 추세를 보였다. 특히, 1950년대 후반을 기점으로 변화율이 급변하였는데, 한강에서 100년 동안 발생한 7번의 무결빙해(1960, 1971, 1972, 1978, 1988, 1991, and 2006)도 모두 1950년대 이후에 발생하였다. 송월과 한강에서 첫 결빙일의 일 최저기온은 평균적으로 각각 0.55˚C와 -12.22˚C이다. 영하의 일 최저기온이 송월은 6.43일, 한강은 8.94일 지속되고 난 뒤 첫 결빙이 발생하였다. 송월과 한강의 연 최저기온에 대해서 첫 결빙일은 양의 상관을 보였고, 결빙 일수는 음의 상관을 보였다. 이러한 결과는 결빙기후의 변화가 기후변화의 일환으로 나타나는 기온변화와 유관함을 보였다. 향후 더 넓은 지역에서 다양한 추가 연구를 실시함으로써, 지속적으로 결빙기후를 주시하고자 한다.
        4,000원
        1363.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We discuss the influence of few-walled carbon nanotubes (FWCNTs) treated with nitric acid and/or sulfuric acid on field emission characteristics. FWCNTs/tetraethyl orthosilicate (TEOS) thin film field emitters were fabricated by a spray method using FWCNTs/TEOS sol one-component solution onto indium tin oxide (ITO) glass. After thermal curing, they were found tightly adhered to the ITO glass, and after an activation process by a taping method, numerous FWCNTs were aligned preferentially in the vertical direction. Pristine FWCNT/TEOS-based field emitters revealed higher current density, lower turn-on field, and a higher field enhancement factor than the oxidized FWCNTs-based field emitters. However, the unstable dispersion of pristine FWCNT in TEOS/N,N-dimethylformamide solution was not applicable to the field emitter fabrication using a spray method. Although the field emitter of nitric acid-treated FWCNT showed slightly lower field emission characteristics, this could be improved by the introduction of metal nanoparticles or resistive layer coating. Thus, we can conclude that our spray method using nitric acid-treated FWCNT could be useful for fabricating a field emitter and offers several advantages compared to previously reported techniques such as chemical vapor deposition and screen printing.
        4,200원
        1364.
        2011.12 구독 인증기관 무료, 개인회원 유료
        The goal of this study is to determine, based on survey results, the underlying factors that affect the intention of the farmers who have not adopted the Hazard Analysis and Critical Control Points (HACCP) system for the rearing phase of pig production to adopt this system in the future. The research model for this study was con structed based on strategic contingency theory, the theory of the diffusion of innovation, and the technology acceptance model (TAM). Using structural equation modeling with partial least squares (PLS), this study analyzes the effects of the intensity of competition, the environmental uncertainty, the innovativeness and self-efficacy of the individual farmers, and the impact of the credibility of the Agricultural Technology Service Center (ATSC), which acts as the principal agent of technology dissemination and as a leader of change, on the perceived usefulness of technology and the farmers’ intention to adopt the system. The results of the analysis are as follows. First, with regard to the underlying factors affecting the intention to adopt the new system, the intensity of competition within the industry and the institutional credibility of the ATSC were inferred to underlie the perceived usefulness. Second, institutional credibility has a positive impact on the perceived usefulness of the system, and the perceived usefulness, in turn, has a positive impact on the intention to adopt. The perceived ease of use also has a positive impact on the intention to adopt. Because the factor that has the biggest impact on the intention of a farm to adopt is the credibility of the ATSC, it is crucial for extension organizations, such as the ATSC, to make greater efforts to promote the expansion of the HACCP system. Because farmers feel that the implementation of the HACCP system is an instrumental strategy for coping with the high intensity of competition within the industry, they attempt to gain a competitive edge through the production of safe livestock products.
        5,500원
        1365.
        2011.12 구독 인증기관 무료, 개인회원 유료
        4,000원
        1366.
        2011.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ultrasonography (US) is a recent technique that has proven to be useful for assessing muscle thickness and guiding the rehabilitation decision-making of clinicians and researchers. The purpose of this study was to determine the inter-rater reliability of the US measurement of transversus abdominis (TrA), internal oblique (IO), and external oblique (EO) thicknesses for different probe locations and measurement techniques. Twenty healthy volunteers were recruited in this study. Muscle thicknesses of the transversus TrA, IO, and EO were measured three times in the hook-lying position. The three different probe locations were as follows: 1) Probe location 1 (PL1) was below the rib cage in direct vertical alignment with the anterior superior iliac spine (ASIS). 2) Probe location 2 (PL2) was halfway between the ASIS and the ribcage along the mid-axillary line. 3) Probe location 3 (PL3) was halfway between the iliac crest and the inferior angle of the rib cage, with adjustment to ensure the medial edge of the TrA. The two different techniques of thickness measurement from the captured images were as follows: 1) Muscle thickness was measured in the middle of the muscle belly, which was centered within the captured image (technique A; TA). 2) Muscle thickness was measured along a horizontal reference line located 2 cm apart from the medial edge of the TrA in the captured image (technique B; TB). The intraclass correlation coefficient (ICC [3,k]) was used to calculate the inter-rater reliability of the thickness measurement of TrA, IO and EO using the values from both the first and second examiner. In all three muscles, moderate to excellent reliability was found for all conditions (probe locations and measurement techniques) (ICC=.70~.97). In the PL1-TA condition, inter-rater reliability in the three muscle thicknesses was good to excellent (ICC=.85~.96). The reliability of all measurement conditions was excellent in IO (ICC=.95~.97). Therefore, the findings of this study suggest that TA can be applied to PL1 by clinicians and researchers in order to measure the thickness of abdominal muscles.
        4,000원
        1367.
        2011.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to examine the effects of gait training using functional electrical stimulation on the improvement of hemiplegic patients' functions for balance and gait velocity. The subjects of the experiment were determined to be 10 each hemiplegic patients who had been diagnosed with stroke or brain damage six months or longer earlier assigned to an experimental group and a control group respectively. The subjects were evaluated before the experiment using Tetrax and 10M gait tests, received gait training five times a week for four weeks using functional electrical stimulation and were evaluated after the experiment in the same method as used in the evaluation before the experiment. In order to examine differences between the experimental group that received gait training using functional electrical stimulation and the control group that was treated by functional electrical stimulation and received gait training thereafter, differences between before and after the experiment were analyzed using paired sample t-tests and differences in changes after the experiment between the experimental group and the control group were analyzed using independent sample t-tests in order to compare the two groups with each other. Experimental results showed significant differences in weight bearing, balance and gait velocity between before and after the experiment in the experimental group(p<.05). In the control group, whereas weight bearing and gait velocity did not show any significant difference between before and after the experiment(p>.05), balance showed significant differences(p<.05). Weight bearing, balance and gait velocity change rates showed significant differences between the experimental group and the control group(p<.05). In conclusion, it was indicated that gait training using functional electrical stimulation is effective for enhancing stroke patients' weight bearing rates, balance abilities and gait velocity.
        4,000원
        1372.
        2011.10 구독 인증기관·개인회원 무료
        Despite of the presence of estradiol-17β (E2) in ovarian follicles, its role(s) in in vitro maturation (IVM) is still largely unknown, especially in pigs. Thus, the current study was conducted to investigate the effect of E2 on in vitro maturation (IVM) of porcine oocytes and subsequent preimplantation development using in vitro fertilization (IVF)- or somatic cell nuclear transfer (SCNT)-derived embryos. To define the effects of E2 on IVM and early embryogenesis, porcine oocytes were matured in the presence or absence of E2, fertilized in vitro and cultivated to blastocyst stage. Compared to control group, the production of MII oocytes was significantly increased by treatment with E2, accompanying with the increase in MPF content and ERK phosphorylation, and monospermic fertilization and blastocyst development rates were also greatly elevated in the E2-treated oocytes. In addition, the advantageous role of E2 was also found in blastomere survival, which was further evidenced by both elevation of anti-apoptotic transcript Bcl-XL and decrease of pro-apoptotic transcript Bax. Furthremore, these positive effects of E2 were highly reproducible in early development of SCNT embryos. Collectively, the current study strongly suggests that E2 can be used as a efficient IVM supplement leading to successful nuclear/cytoplasmic maturatioin in pigs.
        1373.
        2011.10 구독 인증기관·개인회원 무료
        Successful early embryogenesis of somatic cell nuclear transfer (SCNT) embryos is very important to produce cloned animals. However, poor preimplantation development of SCNT embryos has been a major obstacle to the generation of cloned animals due to a lack of understanding of developmental events and underlying mechanism(s). In the current study, we show that production of SCNT embryos with high developmental competence is dependent on the fusion method. Electrofusion causes spontaneous egg activation, accompanied by an increase in intracellular Ca2+ and improper nuclear remodeling, whereas Sendai virus (SV)-mediated fusion greatly reduces these events. In addition, SV-SCNT increased the blastocyst development rate and trophectoderm cell number compared to electrofusion-mediated SCNT (E-SCNT). In particular, expression of ER stress-associated genes and blastomere apoptosis were significantly increased in E-SCNT embryos, which could be alleviated by inhibition of ER stress or by using the SV-mediated fusion method. Taken together, these results strongly suggest that SV is a useful fusion material for improvement of preimplantation development of SCNT embryos through reduction of ER stress-associated apoptosis.
        1374.
        2011.10 구독 인증기관·개인회원 무료
        Plasmids from Bacillus thuringiensis have been implicated in pathogenicity as they carry the genes responsible for different types of diseases that in mammals and insects. A novel serogroup (H3a3b3d), B. thuringiensis strain K4 which showed mosquitocidal activity against Anopheles sinensis and Culex pipiens pallens, was isolated from fallen leaves in Mungyeong city, Republic of Korea. In contrast to the complicated plasmid profiles of B. thuringiensis H3 serotype strains, the strain K4 (designated as serovar mogi) had only one large plasmid (>200kb) on which the toxin genes were occasionally located. A 454 pyrosequencing was used for the complete sequencing of the large plasmid. The sequence analysis showed that k4 plasmid had at least seven putative cry genes, ending up to showing 84%, 75%, 73%, 58%, 84%, 39% and 75% homology with Cry27Aa, Cry19Ba, Cry20-like, Cry56Aa, Cry39ORF2, Cry8Ba and Cry40ORF2 toxins in amino acids, respectively. This novel 3a3b3d type strain, B. thuringiensis serovar mogi, can be used as a good resource for studying unknown mosquitocidal cry genes. The E. coli-B. thuringiensis shuttle vector, pHT1K was used to clone these cry genes for characterization. In each clone, the level of transcription and production of crystal proteins will be investigated in near the future.
        1375.
        2011.10 구독 인증기관·개인회원 무료
        Bacillus thuringiensis (Bt) is characterized by its ability to synthesize crystal toxins and also able to produce bacteriocins such as thuricin, tochicin, entomocin and bacthuricin. The present work, for the first time, describes the biological activity of bacteriocins from B. thuringiensis subsp. cameroun (Btc). Supernatant which was produced from a liquid culture of Btc had antimicrobial activity against various Bt subspecies, ending up to making a inhibition zone on an agar medium. A significant reduction in antimicrobial activity was observed when the supernatant was exposed to heat at 47~50°C for 15 min. Proteins were separated from the supernatant by a fast protein liquid chromatography (FPLC) given the thermal instability. A group of FPLC fractions had antimicrobial activity against Bt subsp. palmanyolensis, israelensis, 1-3, morrisoni, toguchini and kurstaki and a Bacillus. cereus ATCC21768, ATCC14579 and NRRLB-569. Interestingly, when the supernatant was individually incorporated into the liquid cultures of Bt subsp. israelensis (Bti) and mogi (Btm) with mosquitocidal activity, a vegetative cell growth was observed only in the Btm culture 10 h post-incubation. A possible recovery of vegetative Btm cell growth was observed, compared to a control without the supernatant. These results suggest that Btc produced proteinous antimicrobial substances, one of which may be used as a selection marker to separate Btm after possibly conjugating the two mosquitocidal strains.
        1376.
        2011.10 구독 인증기관·개인회원 무료
        Among 154 putative ORFs of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), ac78 and ac79 are highly conserved genes in baculovirus, but their functions in the virus life cycle have been unknown so far. To determine their roles in AcMNPV replication, knockout mutants, ac78KO and ac79KO, were constructed using the plasmid capture system (PCS). Real-Time PCR analysis showed that both of ac78 and ac79 transcripts were first detected at 6 hours post-infection, and accumulated to maximum at 24 hours post-infection, suggesting that both of ac78 and ac79 are belong to late gene. When the genomic DNA of ac78KO was transfected into Sf9 cells, viral replication was restricted to a single cell infection. These results demonstrated that the ac78 play an important role in BV production, and therefore is essential for AcMNPV to mount a successful infection. Whereas Sf9 cells infected with the ac79KO showed normal viral symptoms such as rounding and swelling, OBs were not observed from majority of infected cells. These results suggested that the ac79 might play an important role in OB production.
        1377.
        2011.10 구독 인증기관·개인회원 무료
        톱다리개미허리노린재의 집합페로몬은 수컷에 의해 분비되며 같은 종의 성충과 약충을 유인하는 것으로 알려져 있다. 현재 합성된 집합페로몬을 이용한 유인트랩이 널리 이용되고 있다. 본 연구에서는 합성된 집합페르몬에 대한 톱다리개미허리노린재 성충과 약충의 반응을 먹이 섭식 조건을 달리하여 Y자 후각계(Y-tube olfactometer)를 이용하여 조사하였다. Y자 후각계 끝의 공기와 페로몬이 혼합되는 지점에서 교미경험이 없고 수분만 공급받은 성충의 최초 반응률은 수컷에서 84%, 암컷에서 90%이었다. 그리고 반응한 암컷과 수컷의 69%가 Y자 후각계의 집합페로몬 쪽으로 이동하였다. 제2령 약충에서는 수분과 설탕물을 공급받은 경우 최초 반응률은 각각 60과 56%이었고 그 중 각각 63과 64%가 집합페로몬 쪽을 선택하였다. 다만 콩을 먹이로 충분히 공급받은 제2령 약충은 최초 반응률이 34%로 낮았고 집합페로몬 쪽으로 유인된 비율도 31%로 낮았다. 따라서 톱다리개미허리노린재 약충이 먹이를 섭식한 후에는 집합페로몬에 적게 유인되는 것을 알 수 있다.
        1378.
        2011.10 구독 인증기관·개인회원 무료
        Periodical release of non-viable refrigerated eggs of Riptortus pedestris (Fabricius) has been found to enhance field parasitism level in soybean fields. However, optimum refrigeration conditions required for the eggs in order to preserve its quality to ensure effective level of parasitism for a longer period has been rarely reported. We assessed optimum environment condition for refrigeration of the eggs using three different temperatures (2, 6, and 10℃) and relative humidities (RH) (high, medium and low). Eggs of R. pedestris were refrigerated at nine combinations of temperature and relative humidity for 30 consecutive days. Those eggs were taken out and after 8 days, mated female Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) were individually exposed to the eggs, and their development, emergence, and sex ratio were examined. Number of eggs parasitized was highest (5.9) on eggs stored at 6℃ and high RH. Significantly higher male proportion was recorded in the eggs stored at 10℃. However, RH had no effect on the sex ratio. For both male and female, development time was the least on host eggs stored at 2℃ and high RH. Adult emergence was recorded highest from the eggs stored at 2℃ followed by 6℃ and at high RH. In conclusion, eggs refrigerated below 6℃ at high RH condition maintained better quality of R. pedestris eggs for the parasitization by O. nezarae.
        1379.
        2011.10 구독 인증기관·개인회원 무료
        The green peach aphid, Myzus persicae (Sulzer), is one of the most important insect pests in the world. We have explored the possibility of using sounds as a stressor to control this species. Five sine wave frequencies (100, 500, 1000, 5000, 10000 Hz) with combination of three intensity (66, 78, 90 dB) were used as acoustic stimuli in the playback experiments. For behavioral bioassay, we examined frequencies of honeydew production (HDP) and wagging behavior, and duration of moving behavior. The HDP occurs regularly during each stage of nymphal or mature period, and rate of the HDP indicates a degree of food consumption. Aphids conduct wagging to determine a host plant or to find a feeding site. The moving behavior may be regarded as dispersal. As results, all acoustic stimuli significantly reduced rate of the HDP and increased rate of the moving behavior. There was a significant effect to induce the moving behavior in the test of 5000 Hz. In addition, the acoustic stimuli using 5000 Hz were the most effective to disturb feeding behavior of M. persicae at an individual level.
        1380.
        2011.10 구독 인증기관·개인회원 무료
        Aphids feed on host plants by penetrating the stems or leaves with stylets. The feeding behavior of aphids consists of probing, penetration, salivation, and sap ingestion. To assess the effects of sound on feeding behavior, we monitored the stylet activity of the green peach aphid, Myzus persicae (Sulzer), using electrical penetration graph (EPG). The use of EPG was critical for determining the stage, frequency, and duration of feeding in aphids. We played back four acoustic stimuli of sine waves with frequencies of 100, 500, 1000, and 5000 Hz to adult aphids. When the sound was treated, the frequencies of probing, penetration, and salivation increased, whereas the duration of sap ingestion decreased. The 100 Hz and 500 Hz was significantly effective to disturb ingestion of phloem sap. The results of EPG revealed that the acoustic stimuli may restrict aphid feeding by disturbing sap ingestion.