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        검색결과 1,121

        841.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        Direct communication between neighboring cells via gap junction in tissue is important for maintenance and regulation of its physiological functions. Each epididymal region has different composition of cell types. It is well recognized that the epididymis is a steroid hormone-responsive tissue. The present study was designed to determine the effect of estradiol benzoate (EB) or flutamide exposured at the early postnatal age on the expression of connexin (Cx) isoforms in the caudal epididymis. The EB or flutamide was subcutaneously administrated to male Spragure Dawley rat at 7 days of age, and expressional changes of Cx isoforms in the adult corpus epididymis were determined by quantitative real-time PCR. The treatment of low-dose EB resulted in decreases of Cx30.3, Cx31.1, Cx37, and Cx45 expression but caused an increase of Cx32 expression. Exposure to high-dose EB led into expressional increases of Cx31, Cx31.1, Cx32, Cx40, and Cx43, even though a decrease of Cx37 expression was found with a high-dose EB treatment. A low-dose flutamide induced increases of Cx31, Cx31.1, Cx32, and Cx43 expression but a decrease of Cx37 expression. Expression of most Cx genes were significantly increased by a high-dose flutamide, while no expressional change of Cx26 and Cx40 was detected by a high-dose flutamide. These results indicate that expression of Cx isoforms in the caudal epididymis is altered by exposure to steroidal compounds at the prepubertal age. It is suggested that a contact with environmental exogenous materials during the early postnatal period would lead to alteration of epididymal functions at the adult.
        842.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        In this study, we investigated the characteristics of CCK-producing cells and mucus-secreting goblet cells with respect to stomach fish and stomachless fish of the Gobiidae in order to provide a basis for understanding the digestive physiology. Hairychin goby (Sagamia geneionema), which is stomachless fish, the numbers of mucus-secreting goblet cells is highest in the posterior intestine portion (P<0.05), while CCK-producing cells are scattered throughout the intestine. Gluttonous goby (Chasmichthys gulosus), which is stomach fish, mucus-secreting goblet cells are most abundant in the mid intestine portion (P<0.05), whereas CCK-producing cells are observed only in the anterior and mid intestine portion. Trident goby (Tridentiger obscurus) which is stomach fish, mucus-secreting goblet cells were most abundant in the mid intestine portion (P<0.05). CCK-producing cells are found in the anterior and mid intestine portion. Giurine goby, Rhinogobius giurinus which is also stomach fish, the largest number of mucus-secreting goblet cells showed in anterior intestine portion except for esophagus (P<0.05). CCK-producing cells are present only in the anterior and mid intestine portion. In S. geneionema, digestive action occurs in the posterior intestine portion to protect and functions to activate digestion. In contrast, in C. gulosus, T. obscurus and R. giurinus, their digestive action occurs in the anterior and mid intestine portion to protect and functions to activate digestion. Further studies of the modes of food ingestion by these fish, the contents of their digestive tracts, and the staining characteristics of the goblet cells need to be carried out.
        843.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        Adipose tissue is one of the major endocrine gland. More recently, local production of steroids in adipocytes differentiated from mouse 3T3-L1 cell-line was reported. We hypothesized that rat adipocytes have steroidogenic machinery and the expression patterns of the components might be differentially regulated, depending on the distribution and sex. To verify this hypothesis, we collected the adipose tissues depot- and sex-specifically at postnatal day (PND) 30, and performed quantitative RT-PCRs. In overall aspects, the abundances of the transcripts were lower in the brown adipose of both sexes. 3β-HSD transcript levels in female abdominal and reproductive adipose, CYP17 transcript levels in female reproductive adipose, 17β-HSD transcript levels in female abdominal and reproductive adipose, and CYP19 transcript levels in female abdominal adipose were significantly lower than those of male counterparts. Similar to steroidogenic factors, the abundance of the ER-α transcripts were generally lower in the brown adipose of both sexes. ER-β transcripts were more abundant in male white adipose depots than their female counterparts. The levels of LHR transcripts in female reproductive adipose were significantly higher than those of male counterpart. In conclusion, our study demonstrated that the expressions of steroidogenesis-related genes were depot- and sex-specifically occurred in the immature male and female rat adipose tissues. Our study suggested that the adipose tissues are not only targets but de novo synthesizing sites of sex steroid(s), though the synthesizing activities could be much less than in gonads. Further researches in this field will be helpful for understanding the adipose physiology and for medical application such as sex-specific steroid supplement therapies for older populations.
        844.
        2016.07 KCI 등재 서비스 종료(열람 제한)
        High-rank coals are limited, while low-rank coals are abundant. However, the low-rank coals needs upgradation so as to improve their quality. If not, the utilization of low-rank coals will lead to many operational difficulties. As this study was made in South Korea, this article discusses the energy and coal scenario of South Korea. The critique discusses the concerns of utilizing low-grade coal and the need for upgrading low-grade coal. The article also briefly discusses the currently practiced low-rank coal upgradation techniques. Also, the review paper suggests some best upgradation techniques.
        845.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to develop an effective seed propagation method for Thalictrum rochebrunianum var. grandisepalum (H. Lev.) Nakai by analyzing seed dormancy types and germination characteristics. Seeds were collected between September to October at Gangwon province, and well-selected seeds were used while being dry-stored at 4±1℃. The seed size ranged 4.52 × 1.58 ㎜ and the weight of thousand seeds were 1,603.5 ± 0.02 ㎎. The moisture content was 7.2%. Seeds were achene type, and morphology characters showed an elliptical shape and rough texture, and light brown in color. Moist-chilling treatment was conducted for dormancy breaking because the seeds had an undeveloped embryo of liner type. The embryo had developed during a moist-chilling period, constantly, and fully developed in 10 weeks. Consequently, it seemed to be non-deep complex or intermediate complex type of morphophysiological dormancy, and embryo dormancy was broken by wet-chilling for 10 weeks. After 10 weeks of wet-chilling treatment, seed germination began. Germination percentage was higher in dark condition raher than light condition and recorded the maximum at 25℃ in the dark (16.3%). A pre-soaking treatment with a combined plant growth hormones promoted germination and shortened T50. Specifically, seed germination of 84.5% was achieved by pre-soaking of seeds with a combined solution of 500 ㎎/L GA3 and 10 ㎎/L kinetin for 24 h after a wet-chilling treatment for 10 weeks. Thus the effect of plant growth hormones coupled with chilling temperature on seed breaking dormancy provide asubsequent growth of seedlings for successful plantation.
        846.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        Understanding the genetic variation among landrace collections is important for crop improvement and utilization of valuable genetic resources. The present study was carried out to analyse the genetic diversity and associated population structure of 621 foxtail millet accessions of Korean landraces using 22 EST-SSR markers. A total of 121 alleles were detected from all accessions with an average of 5.5 alleles per microsatellite locus. The average values of gene diversity, polymorphism information content, and expected heterozygosity were 0.518, 0.594, and 0.034, respectively. Following the unweighted neighbor-joining method with arithmetic mean based clustering using binary data of polymorphic markers, the genotypes were grouped into 3 clusters, and population structure analysis also separated into 3 populations. Principal coordinate analysis (PCoA) explained a variation of 13.88% and 10.99% by first and second coordinates, respectively. However, in PCoA analysis, clear population-level clusters could not be found. This pattern of distribution might be the result of gene flow via germplasm exchanges in nearby regions. The results indicate that these Korean landraces of foxtail millet exhibit a moderate level of diversity. This study demonstrated that molecular marker strategies could contribute to a better understanding of the genetic structure in foxtail millet germplasm, and provides potentially useful information for developing conservation and breeding strategies.
        847.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This study examined the effects of trifoliate orange extract (TOE) on inflammatory reactions at the time of an LPS shock by performing experiments on rats injected with trifoliate orange extract and in Raw 264.7 cell cultures, with the aim of developing a new anti-inflammatory medicine. The IL-1β, IL-6, and TNF-α concentrations were lower in all of the groups treated with TOE than in the control group after 5 h of LPS treatment. The IL-10 concentration was higher in the 300- ㎎/㎏ TOE group than in the control group after 2 h and 5 h of LPS treatment. The liver concentrations of cytokines IL-1β and IL-6 decreased more in the groups treated with TOE than in the control group and the IL-6 concentration did not differ significantly between the 100-㎎/㎏ TOE group than in the control group. The TNF-α and IL-10 concentrations did not differ significantly between the TOE groups and the control group. In the experiments involving Raw 264.7 macrophage cultures subjected to LPS shock, the productions of IL-1β, IL-6, and TNF-α decreased in all of the groups treated with TOE compared to the control group. The IL-10 concentration did not differ significantly between the groups treated with TOE and the control group. Together the findings of this study suggest that TOE contains functional substances that can influence inflammatory reactions.
        848.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This study was executed to evaluate the immune activity, nitrite scavenging activity and ABTS radical scavenging activity against extracts of various concentration of ethanol solvent from Codonopsis lanceolata cultured at 6 local regions. The immune responses from both human T and B cell line was significantly enhanced in the cell growth compared to control while the cell growth was influenced at a certain period of culture. The results revealed that the cell growth of both human T and B cell was altered in a time dependent manner. The nitrite scavenging activity of ethanol extracts from various solvent concentration of C. lanceolata were affected by pH. At a pH of 1.2, the nitrite scavenging effect of all of the extracts tested observed higher than that of the other two pH ranges. There was no distinct detection of nitrite scavenging effects of the pH range 6.0. The ABTS radical scavenging activity was progressively increased in a dose-dependent manner, and the activity was the highest in 100% ethanol extract. The result from this investigation suggests that the extract of Codonopsis lanceolata could be an addition to basic medicine for immune modulation and natural food additives.
        849.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This study describes results on sexual maturation and characteristics of natural spawned eggs to develop a method for the production of stable, healthy fertilized eggs from captive-reared yellowtail kingfish, Seriola lalandi. A total of 59 yellowtail kingfish were captured off the coast of Jeju Island, after which the broodstock was cultured in indoor culture tank (100 m3) until they were 6.1–14.9 kg in body weight. As part of the rearing management for induced sex maturation, the intensity of illumination was maintained at 130 lux. The photoperiod (light/dark; L/D) was set to a 12 L/12 D from October 2013 to January 2014, and 15 L/9 D from February 2014 to June 2014. Feeds comprised mainly EP (Extruded Pellets), with squid cuttlefish added for improvement of egg quality, and was given from April to June 2014. The first spawning of yellowtail kingfish occurred in May 3, 2014, at a water temperature of 17.0°C. Spawning continued until June 12, 2014, with the water temperature set at 20.5°C. Time of spawning was 26 times at this period. The total number of eggs that spawned during the spawning period was 4,449×103. The buoyant rate of spawning eggs and fertilization rate of buoyant eggs during the spawned period were 76.1% and 100%, respectively. The diameters of the egg and oil globule were 1.388 ± 0.041 mm and 0.378 ± 0.029 mm, respectively, which was higher in early eggs than in those from late during the spawned period.
        850.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        Lipopolysaccharide (LPS), an endotoxin, elicits strong immune responses in mammals. Several lines of evidence demonstrate that LPS challenge profoundly affects female reproductive function. For example, LPS exposure affects steroidogenesis and folliculogenesis, resulting in delayed puberty onset. The present study was conducted to clarify the mechanism underlying the adverse effect of LPS on the delayed puberty in female rats. LPS was daily injected for 5 days (50 μg/kg, PND 25-29) to treated animals and the date at VO was evaluated through daily visual examination. At PND 39, animals were sacrificed, and the tissues were immediately removed and weighed. Among the reproductive organs, the weights of the ovaries and oviduct from LPS-treated animals were significantly lower than those of control animals. There were no changes in the weights of uterus and vagina between the LPS-treated and their control animals. Immunological challenge by LPS delayed VO. Multiple corpora lutea were found in the control ovaries, indicating ovulations were occurred. However, none of corpus luteum was present in the LPS-treated ovary. The transcription level of steroidogenic acute regulatory protein (StAR), CYP11A1, CYP17A1 and CYP19 were significantly increased by LPS treatment. On the other hand, the levels of 3β- HSD, 17β-HSD and LH receptor were not changed by LPS challenge. In conclusion, the present study demonstrated that the repeated LPS exposure during the prepubertal period could induce multiple alterations in the steroidogenic machinery in ovary, and in turn, delayed puberty onset. The prepubertal LPS challenge model used in our study is useful to understand the reciprocal regulation of immune (stress) - reproductive function in early life.
        851.
        2016.05 KCI 등재 서비스 종료(열람 제한)
        스위니 아고니스테스 는 극적 형태에 있어서 T. S. 엘리엇의 첫 번 째 탐구 작업인 바, 대체적으로 실패라고 여겨지고 있다. 그러나 엘리엇 이 이 시를 자신의 시 전집들에 포함시켰다는 사실은 독자들로 하여금 그것의 의미를 그의 작품 전체 속에서 숙고하게 만든다. 그의 초기 작 품들의 명백한 미숙함으로부터의 이탈이 변화나 역전의 신호가 아니라 그의 정서의 확대나 발전이라는 그의 안내를 따라간다면, 이 시는 보통 사람들의 감상주의적인 성향에도 불구하고 보통 사람들의 정서를 변화 시키려는 첫 번째 단계인 것이다. 이 시가 인기가 많았던 마리 로이드 처럼 관객에 대한 정서적 혁명의 영향력을 극대화하는 첫 번째 단계로 의 입문이었기 때문에, 단순히 ‘실패’라기보다는 ‘성공적인 실패’라고 정 의되어야 한다. 이러한 실패의 결과로 이어지는 시극들 전부에서 ‘유머’ 의 어조가 ‘심각함의 어조로 바뀌었다. 하지만 관객의 의식적인 관심을 요구하겠다는 그의 전략의 이러한 변경이 엘리엇의 정서적 혁명의 최종 목표인 공동체의 영적 가치관을 변화시키기에 충분히 좋지는 않았다.
        852.
        2016.05 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Since World War II nations have formed alliances for reasons of security and trade. Countries have seen international integration as an appropriate approach to resolving domestic and international political issues, improving their welfare by both transforming their infrastructures and increasing their foreign trade. While the majority of these relationships are straightforward d Turkey’s relationship with the European Union is more complex due to differences in religion and, at times, political ideology from other Union members. As a candidate country Turkey has made advances towards the full membership of the European Union with the customs union being the most significant. The impact of customs union membership is discussed and the effects of the customs union on Turkey’s trade and economy are examined from a perspective of different economic theories.
        853.
        2016.03 KCI 등재 서비스 종료(열람 제한)
        In fish, light (photoperiod, intensity and spectra) is main regulator in many physiological actions including growth. We investigate the effect of light spectra on the somatic growth and growth-related gene expression in the rearing tiger puffer. Fish was reared under different light spectra (blue, green and red) for 8 weeks. Fish body weight and total length were promoted when reared under green light condition than red light condition. Expression of somatostatins (ss1 and ss2) in brain were showed higher expression under red light condition than green light condition. The ss3 mRNA was observed only higher expression in blue light condition. Expression of growth hormone (gh) in pituitary was detected no different levels between experimental groups. However, the fish of green light condition group was showed more high weight gain and feed efficiency than other light condition groups. Our present results suggest that somatic growth of tiger puffer is induced under green light condition because of inhibiting ss mRNA expression in brain by effect of green wavelength.
        854.
        2016.03 KCI 등재 서비스 종료(열람 제한)
        Molecular targeting for the altered signaling pathways has been proven to be effective for the treatment of many types of human cancer, including colorectal cancer (CRC). The dual phosphatidylinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) inhibitor BEZ235 has shown to exhibit potent antitumor activity against solid tumors. Autophagy is a cellular lysosomal catabolic process to maintain metabolic homeostasis, which has been known to be induced in response to many therapeutic agents in cancer cells. This process is negatively regulated by mTOR and often acts as prosurvival or prodeath mechanism following cancer therapeutics. The current study was designed to investigate the antiproliferation activity of BEZ235 and to evaluate the role of autophagy induced by BEZ235 using HCT15 CRC cells bearing ras oncogene mutation. We found that BEZ235 decreases cell viability, which was mostly dependent on G1 arrest of cell cycle via suppression of cyclin A expression. BEZ235 affects PI3K/Akt/mTOR signaling pathway by increasing the phosphorylation of AKT at Ser473 and RAS/RAF/MEK/ERK pathway by decreasing the phosphorylation of ERK at Tyr204. BEZ235 also stimulated autophagy induction as evidenced by the increased expression of LC3-II and abundant acidic vesicular organelles (AVOs) in the cytoplasm. In addition, the combination of BEZ235 with autophagy inhibitor chloroquine, a known antagonist of autophagy, counteracted the antiproliferation effect of BEZ235. Thus, our study indicates that autophagy induced in response to BEZ235 treatment appears to act as cell death mechanism in HCT15 CRC cells.
        855.
        2016.03 KCI 등재 서비스 종료(열람 제한)
        Purpose – The purpose of this study is to measure the characteristics of the perceived quality of college students of 20s which is the main customers of whitening, and to investigate the customer satisfaction and repurchase intentions according to the perceived quality of whitening. Research design, data and methodology – The interviewers in the research are 300 college students in Seoul and the metropolitan area. They were collected from October 1 to October 24, 2013. 283 of collected questionnaires were used for the analysis. The analysis in the general characteristics of the subjects was analyzed by frequency analysis. With five-dimensional factor analysis, the perceived quality through reliability analysis was investigated and verified. Results – The results from analysis of the standardized coefficient Beta value were performance(0.382), brand (0.339), and price (0.318) as a high level. On the other hand, services(0.172) and design factors (0.162) were relatively low. Conclusion – Looking for these results, this study could reach the notion that a lot of consumers with whitening cosmetics highly recognized brand, performance, and price factors, but the service and design factors were relatively recognized low in customer satisfaction and repurchase intentions.
        856.
        2016.01 KCI 등재 서비스 종료(열람 제한)
        The objective of this study was to examine the torrefaction process of three lignocellulose biomasses (rice husks, coffee shell, and wood) produced in Vietnam. Three different torrefaction temperatures ranging from 200oC to 300oC and three residence times of 20, 40, and 60 min were considered. The result showed that temperature had a higher effect on torrefaction process of biomass than residence time. Based on the findings of this study, a residence of 40 min could be suggested for an effective and proper torrefaction process to recycle the agricultural biomass and wood at 300oC. The torrefied products become fuel sources which can be applied to replace with fossil fuels.
        857.
        2016.01 KCI 등재 서비스 종료(열람 제한)
        The objective of this study is to investigate the potential use of MSW incineration fly ash as an economic material for the removal of heavy metals (Pb, Mn, Fe, and Cu) from AMD. Batch adsorption experiment was conducted to examine the effects of pH, adsorbent dosage and contact time on metal ions removal in synthetic AMD using MSW incineration fly ash. Precipitation of calcium hydroxide and sodium hydroxide was used for comparison with MSW incineration fly ash by adjusting the pH (5 ~ 11) by coagulation method with 20 min reaction time. Comparing the application of Ca(OH)2 and Na(OH), fly ash proves more efficient which may be due to its porosity and chemical composition. The results from adsorption studies showed that maximum adsorption rate was achieved at 0.4g dose when various fly ash dosages were added to the solution with 60 min optimum time and removal efficiency of heavy metals was over 96%. The effectiveness of fly ash can be related to its high calcium (CaO 55%) content. Efficiency of heavy metals removal was directly linked to the amount of fly ash in the reaction mixture and to the final pH attained. pH plays a significant role in heavy metal uptake. The main removal mechanism was adsorption at the surface of the fly ash together with the precipitation and co- precipitation from the solution with chemicals. Therefore the use of MSW incineration fly ash for treatment of AMD would represent a new market opportunity for this waste product. It can also be useful for neutralizing AMD and possibly reduce its adverse effects to the environment with efficient removal of metal ions from AMD.
        858.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        Twenty apple germplasm accessions from the Korean Genebank were successfully cryopreserved using two-step freezing to back up genetic resources maintained by field collections. This study examined the morphological and genetic stability of cryopreserved dormant apple buds that were stored in liquid nitrogen, and then rewarmed and regrown. Whole plants were regenerated directly from dormant buds through budding without an intermediary callus phase. The cryopreserved buds produced high levels of shoot formation (76.2-100%), similar to those of noncryopreserved buds (91.3-100%), with no observed differences between cryopreserved and noncryopreserved materials. Three of the twenty cryopreserved apple germplasm accessions were used to assess morphological and genetic stability. No differences in morphological characteristics including shoot length, leaf shape, leaf width/length ratio, and root length were observed between controls (fresh control and noncryopreserved) and cryopreserved plantlets. The genetic stability of regenerants (before and after cryopreservation) was investigated using inter simple sequence repeat (ISSR) markers. The ISSR markers produced 253 bands using four primers, ISSR 810, SSR 835, ISSR 864, and ISSR 899. These markers showed monomorphic banding patterns and revealed no polymorphism between the mother plant and regenerants before and after cryopreservation, suggesting that cryopreservation using two-step freezing does not affect the genetic stability of apple germplasm. These results show that two-step freezing cryopreservation is a practical method for long-term storage of apple germplasms.
        859.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        We micropropagated pear (Pyrus species) using shoot tips and nodal explants from three pear genotypes. The ability to establish shoot tip cultures, proliferate shoots, induce rooting, and acclimatize the resulting plantlets are all elements of in vitro micropropagation. Shoots were induced from shoot tips on Murashige and Skoog medium (MS) with five different plant growth regulator combinations. The highest shoot formation rates were achieved for the three genotypes using MS supplemented with 1.0 ㎎/L N 6 -benzyladenine (BA) and 0.1 ㎎/L gibberellic acid (GA3). The maximum shoot number and shoot length for the three cultivars were recorded with 2.0 ㎎/L BA and 0.2 ㎎/L indole-3-butyric acid (IBA) in multiplication medium using nodal explants produced from microshoots. Nodal explants with one or two axillary buds cultured for three weeks initiated roots on medium supplemented with various concentrations of 1-naphthaleneacetic acid (NAA) or/and IBA in half-strength MS medium for adventitious rooting. The highest rooting response was with the combination of 0.2 ㎎/L NAA and 0.2 ㎎/L IBA. A combination of NAA and IBA resulted in a significant increase in the rooting ratio over NAA or IBA alone. In this medium, the root formation rate according to ranged from 68.9% for the BaeYun No. 3 genotype to 51.8% for the Hwanggeum genotype. We also investigated the influence of the concentration the polyamine phloroglucinol in rooting medium. For all three genotypes, the highest rooting ratio, longest root length, and greatest root number were observed in the treatments with 75-150 ㎎/L phloroglucinol. Most rooted plants were acclimatized successfully.
        860.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        β amyloid protein (Aβ) plays a critical role in the pathogenesis of Alzheimer's disease (AD) and possibly in Aβ -induced mitochondrial dysfunction and oxidative stress. Aβ can directly cause reactive oxygen species (ROS) production. Overproduction of ROS is considered to be involved in the pathogenesis of neurodegeneration of AD. Here, we investigated 9 kinds of ramie (Boehmeria nivea, (L.) Gaud., BN; hereafter denoted as BN) for their protective action against oxidative stress in a cellular system using C6 glial cells. We observed loss of cell viability and high levels of ROS generation after treatment with hydrogen peroxide (H2O2) and Aβ25-35. However, treatments with BN extracts led to an increase in cell viability and decrease in ROS production induced by H2O2 and Aβ25-35. In particular, the extracts of BN-01 (seobang variety from Seocheon) and BN-09 (local variety from Yeonggwang) showed excellent anti-oxidative properties. This indicates that BN extracts could prevent neurodegeneration by reducing oxidative stress in cells.