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        검색결과 20

        4.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        알루미나 콜로이드 용액의 막여과에서 막모듈의 중력에 대한 경사각 변화로 유발된 자연대류 불안정 흐름(natural convection instability flow, NCIF)의 콜로이드 물질의 막오염 제어 효과를 정압(constant-pressure) 막여과 시 플럭스 증가와 정투과량(constant-flux) 막여과 시 막차압 감소 정도로 측정하고, 플럭스 결과를 막힘여과 모델로 해석하였다. 막모듈의 경사각이 0°에서 180°로 커지면 NCIF 유발이 증가하여 막오염 제어 효과가 커져 2시간의 막여과에서 플럭스는 최대 2.8배까지 증가하고, 막차압은 최대 85%까지 감소하였다. 막힘여과 모델을 적용하여 NCIF의 유발에 따른 플럭스 결과를 해석하여 운전 시간 15분 이내에서는 중간막힘모델 그 이후에는 케이크여과모델로 평가하는 것이 타당하였다. 막모듈 경사각 180°에서 유발 된 NCIF는 15분 이내의 운전 초기에는 중간막힘 오염을 52% 감소시키고, 그 이후의 운전 시간에서는 케이크층 오염을 93% 감소시켰다. 따라서 막모듈에 유발된 NCIF의 주된 막오염 제어기작은 막표면에의 입자상 콜로이드 물질의 케이크층 형성을 억제시키는 것으로 평가하였다.
        4,000원
        6.
        2019.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        BSA 용액의 전량 한외여과에서 막모듈의 중력에 대한 경사각(0~180°) 변화에 따라 유발된 자연대류 불안정 흐름 (natural convection instability flow; NCIF)의 막오염 제어 효과를 플럭스 증가 정도로 측정하고 막힘여과 모델로 해석하였다. 막모듈의 경사각이 0°에서 180°로 커질수록 NCIF 유발이 증가하여 막오염 제어 효과가 커져 플럭스가 증가하였다. NCIF의 유발이 가장 큰 경사각 180°에서의 플럭스 값을 NCIF의 유발이 없는 0°에서의 값과 비교한 결과, 2시간의 단기간 운전에서는 플럭스 향상성이 5배, 20시간의 장기간 운전에서는 17배까지 증가하였다. 막힘여과 모델을 적용하여 NCIF의 유발에 따른 플럭스 증가 효과를 해석한 결과, 운전시간 15분 이내에서는 중간막힘 모델 그 이후에는 케이크여과 모델로 해석하는 것이 타당하였다. 막모듈 경사각 180°에서 유발된 NCIF는 15분 이내의 운전 초기에는 중간막힘 오염을 67%까지 감소시키고, 그 이후의 운전 시간에서는 케이크층 오염을 99.9%까지 감소시켰다. 따라서 막모듈에 유발된 NCIF의 주된 막오염 제어 기작은 케이크층 형성을 억제시키는 것이었다.
        4,300원
        9.
        2017.11 구독 인증기관·개인회원 무료
        In this work, we studied systematically the effects of NCIF on defouling for a range of solutes that foul (BSA protein) and form cakes (alumina colloids) on the membrane thereby causing severe reduction in the flux. Changing the gravitational orientation of the batch cell induces NCIF in the membrane module and higher inclined angle offers stronger NCIF. This induced NCIF enhances back transport of the deposited solutes away from the membrane surface, therefore gives for the improvement of membrane performance. The flux results according to the inclined angles (from 0° to 180°) of the batch cell were analyzed by the pore blocking filtration model. It was shown that NCIF reduced the fouling of intermediate pore blocking by about 66% at the beginning of UF operation, and thereafter reduced the fouling of cake filtration by about 98%.
        11.
        2016.10 구독 인증기관·개인회원 무료
        Bisphenol‒A (BPA) is a known endocrine‒disrupting chemical used extensively to manufacture plastic bottles, canned food linings, thermal receipts, and other commonly used items. BPA is capable of inducing chromosomal alterations in germ cell line, thereby produced transgenerational effects on brain function, social recognition, reproductive diseases, sperm quality, gene expression, and obesity. Here, we aimed to investigate the transgenerational effects of BPA on murine male fertility. Six-week-old male mice (F0) were gavaged with corn oil (control), two different doses of BPA (5 mg, and 50 mg·kg bw-1·day-1),andethinylestradiol(EE,0.4mg·kg bw-1·day-1), dailyfor6weeks. Treated male mice were mated with wild‒type female and sibling pairs were bred up to the third generation (F3) in a similar manner with no further BPA exposure. Testes and spermatozoa were collected from 14-week-old males of all generation (F0 to F3) to evaluate testis weight, sperm function, and fertility. We found that high concentration of BPA significantly increased testicular weight in F2. Although the sperm viability, capacitation status, and intracellular ROS levels were not affected by BPA, however, sperm count, motility, hyperactivated motility, and intracellular ATP levels were significantly altered by BPA, dose dependently. In majority of the cases the effects were prominent in F2 followed by F1 and F0, whereas the effects were diminished in F3 generation. Simultaneously, high concentration of BPA significantly decreased cleavage and blastocyst formation rate in both F1 and F2. Similar inhibitory effects on cleavage and blastocyst were also noted in F1 by low dose of BPA. Depending on these findings we conclude that BPA decreases the fertility potential of exposed males and has an adverse impact on sperm function and fertility in subsequent generations.
        12.
        2016.10 구독 인증기관·개인회원 무료
        Processes of cryopreservation consists of three steps: dilution with the extender/cooling (Step 1), addition of cryoprotectant (Step 2), and freezing/thawing (Step 3) and spermatozoa are exposed different kind of environment and stress in each step. We categorized sperm samples as good freezablitiy (GF), damaged by cryoprotectant (DCP), and damaged by freezing (DF) and identified characteristics of each group in different step of cryopreservation. In Step 2, DCP was significantly decreased in motility, rapid speed and increased in slow speed. DF was significantly decreased in only motility whereas there were no significant difference between GF and DF and significantly higher than DCP in Step 2. Motility, rapid, medium speed of all group were significantly decreased in Step 3 and GF was significantly higer than other groups. AR pattern of all groups were significantly increased in Step 3 whereas GF was significantly lower than other groups. Additionally AR pattern of DF was significantly increased in Step 2. F pattern of DF and DCP were significantly decreased in Step 3. There no difference of B pattern in whole process. Mitochondrial activity of DCP was significantly decreased in Step 2 and mtichondrial activity of all groups were significantly decreased in Step 3. However mtichondrial activity of GF was higher than other groups. Viability result shows same significant difference with mitochondrial pattern. The present study compared with various sperm parameters in different groups which has different freezability. We defined different two types of group that damaged from different step of cryopreservation. DF and DCP is mainly damaged in Step 3 and Step 2 respectively. The results of current study suggest that various sperm parameters can be used as physical markers in freezability.
        13.
        2015.12 구독 인증기관 무료, 개인회원 유료
        Iron is required for cell viability but is toxic in excess. While the iron-mediated malfunction of testicular cells is well appreciated, the underlying mechanism(s) of this effect and its relationship with fertility are poorly understood. Ferritin is a ubiquitous intracellular protein that controls iron storage, ferroxidase activity, immune response, and stress response in cells. Ferritin light chain protein (FTL) is the light subunit of the Ferritin. Previously, we had identified the FTL in bovine spermatozoa following capacitation. In present study, to investigate the role of Ferritin in sperm function, mice spermatozoa were incubated with multiple doses (1, 10 and 100 μM) of sodium nitroprusside (SNP), an iron donor. SNP was increased Ferritin levels in a dose-dependent manner. The Ferritin was detected on the acrosome in spermatozoa by immunocytochemistry. Short-term exposure of spermatozoa to SNP increased tyrosine phosphorylation and the acrosome reaction (AR). Finally, SNP affected a significant decrease in the rate of fertilization as well as blastocyst formation during early embryonic development. On the basis of these results, we propose that the effects of Ferritin on the AR may reduce overall sperm function leads to poor fertility in males and compromised embryonic development.
        4,000원
        14.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        The present study aimed to examine participants’ perception regarding improvements in education for their return to a mountain village, based on “satisfaction, motivation’s achievement, and effectiveness.” Survey was conducted with 80 participants in 2017, of which 64 valid responses were used for statistical analysis. SPSS 21.0 program was used to conduct descriptive statistics, reliability analysis, factor analysis, and multiple regression analysis. The major findings were that a higher level of “satisfaction regarding the instructor and teaching materials” resulted in a higher level of motivation’s achievement of technology skills, social skills and effectiveness in interpersonal exchange. The findings also revealed that if “the content of education” were satisfactory, there was effective self development. In addition, the higher the motivation’s achievement of social skill, the higher the perception in effectiveness of self development and interpersonal exchange. The study can contribute to provide baseline data for improvement of education on return of people to their mountain villages, which are collaborating with civic groups, governments, research institutions and enterprises.
        15.
        2015.09 서비스 종료(열람 제한)
        Cryopreservation allows for the advances of the reproductive technique and livestock industry. However, cryopreservation inevitably causes various types of stress, such as cold shock, osmotic stress, and ice crystal formation, thereby reducing fertility. Although cryoprotectant agent (CPA) is added to protect spermatozoa from freezing damage during cryopreservation, it has intrinsic toxicity that can affect components of the sperm membrane. Moreover, the addition of CPA induces osmotic stress and excessive reactive oxygen species (ROS) generation, resulting in disruption of mitochondrial membrane potential, alteration of membrane permeability, and damage of sperm surface proteins. To identify the effects of CPA to spermatozoa, we analyzed the sperm movement, capacitation status, and viability using computer-assisted sperm analysis and Hoechst 33258/chlortetracycline fluorescence staining. Moreover, we performed two-dimensional electrophoresis to find protein markers related CPA addition in cryo processes. CPA addition reduced sperm motility (%), viability (%), and non-capacitated spermatozoa, whereas acrosome-reacted spermatozoa increased significantly (p<0.05). Following addition of CPA, a total of ten proteins were altered their expression (eight increased, two decreased) (>3 fold, p<0.05). Among these, four differentially expressed proteins were related to several canonical pathways, such as the ephrinR-actin, ROS metabolism, actin cytoskeleton assembly, actin cytoskeleton regulation, and respiratory chain and oxidative phosphorylation pathway (p<0.05). The present study suggests that CPA significantly alters the functions and proteome content of spermatozoa. Additionally, we anticipated that the differentially expressed proteins might consider as biomarker of CPA-induced stress.
        16.
        2015.09 서비스 종료(열람 제한)
        Prognosis and diagnosis of male fertility is a most important for animal breeding system and human reproduction. Conventional semen analysis generally provides information on the quantitative parameters of spermatozoa, but yields no information concerning its functional competence. Thus, new methods for diagnosis and prognosis of male fertility will need to be developed to ensure more accurate assessments. Proteomics have used to find candidate biomarkers for male fertility, but the relationship between the proteome and fertility was not fully understood. Therefore, we performed a comprehensive proteomic approach to investigate small and large litter size boar spermatozoa and identify proteins related to negative male fertility. In present study, 20 proteins showed differential expression levels in small and large litter size groups. Nineteen of these proteins were abundantly expressed in the small litter group. Interestingly, only one protein was highly expressed in the large litter size spermatozoa. We then identified signaling pathways associated with the differentially expressed protein markers. Glutathione S-transferase Mu3 and glutathione peroxidase 4 were related to the glutathione metabolic pathway and arginine vasopressin receptor 2 was linked to vasopressin R2/STAT. Taken together, our results suggest that identified negative fertility-related biomarkers may be used as negative biomarkers for the detection of inferior male fertility such as sub-fertility or infertility.
        17.
        2015.09 서비스 종료(열람 제한)
        Although the toxicological impacts of the xenoestrogen bisphenol-A (BPA) have been studied extensively, but its mechanism of action is poorly understood. Eventually, no standard method exists for evaluating the possible health hazard of BPA. Considering mice spermatozoa as a potential in vitro model, here we demonstrated the effects of BPA exposure (0.0001, 0.01, 1, and 100 μM for 6 h) on spermatozoa and the related mechanisms of action. Our results demonstrated that high concentrations of BPA negatively affect sperm motility, viability, intracellular ATP, and mitochondrial functions by activating the mitogen-activated protein kinase, phosphatidylinositol 3-kinase, and protein kinase-A pathways. The same doses were also employed to identify the differential expressed proteins of exposure and screen their functional affiliation to diseases using sperm proteomics and informatics, respectively. Our results demonstrated that a high concentration of BPA (100 μM) induced differential expression (> 2-fold) of 24 proteins in spermatozoa (16 down- and 9 up-regulated), that are putatively involved in the pathogenesis of several diseases. To the best of our knowledge, this is the first study to demonstrate the mechanisms of BPA action in spermatozoa and to identify the possible biomarkers of exposure. Moreover, we anticipated that current strategy might apply for the hazard assessment of other toxicological agents.
        18.
        2015.09 서비스 종료(열람 제한)
        As an endocrine disruptor, bisphenol-A (BPA) causes several functional and behavioral abnormalities related to reproduction. The current study was design to evaluate the effect of perinatal exposure of female mice to BPA on sperm function of adult F(1) offspring. Pregnant female mice F(0) were gavaged with three different concentration of BPA, such as 50 μg/kg/day (tolerable daily intake value by the European Food Safety Authority), 5 mg/kg/day (no-observed-adverse-effect level; NOAEL), and 50 mg/kg/day (lowest-observed-adverse-effect level; LOAEL) and corn oil (7 mg/kg/day; vehicle control). The functional parameters of F(1) spermatozoa were studied both before and after capacitation, whereas the fertility assessment was evaluated by in vitro and in vivo assay using unexposed females. Our results showed that spermatozoa hyperactivated motility, capacitation, intracellular ATP, Ca2+, and ROS levels after capacitation were significantly affected using NOAEL and LOAEL concentration of BPA. However, the sperm motility was only affected by LOAEL dose after capacitation. All of the tested parameters were potentially unaffected by BPA before capacitation, except intracellular ATP that decreased by all concentrations. Although both NOAEL and LOAEL concentration were effectively reduced the rate of fertilization and embryonic development in vitro, however the average litter size was only affected by LOAEL dose. Our finding suggested that perinatal exposure of 50 μg/kg/day did not produce significant effects; however both NOAEL and LOAEL affects overall sperm function after capacitation, leading to impairments in the fertility of F(1) male offspring.
        19.
        2015.07 서비스 종료(열람 제한)
        The next-generation sequencing(NGS) technology is being used for more effective genetic mapping. In previous study, we obtained 60x coverage of sequence from Milyang23 and Gihobyeo on average comparing with Nipponbare reference genome. Also, we developed new derived cleaved amplified polymorphic sequence(dCAPS) markers based on the single nucleotide polymorphisms(SNPs) in coding region sequence(CDS) between these varieties. Totally, 1,726,798 SNPs between Milyang23 and Gihobyeo were detected. Among them, 146 SNP were selected for making dCAPS markers and located on genetic map with previously reported 219 PCR-based DNA markers. The map was applied to the detection of quantitative trait loci(QTLs) for stem internode diameters, culm length and panicle length within MGRIL population, and six QTLs with relatively high LOD score were found at three chromosomes; culm length and stem diameter including the first internode diameter, third and fourth internode diameter. This study showed that the NGS allowed the rapid discovery of a large number of SNPs for dCAPS marker. So, we tried to find out more single nucleotide polymorphisms(SNPs) which were located on the whole genome sequence, such as un-translated region(UTR), intron, Inter-region and coding region sequence(CDS) between Milyang23 and Gihobyeo varieties. And we collected phenotypic information about culm length, panicle length, four stem internode diameters and panicle number in rice MGRIL population for QTLs. Furthermore, results of QTL analysis described above will shows relevance of molecular markers in mapping genes for useful breeding.
        20.
        2014.09 서비스 종료(열람 제한)
        The present study aims to investigate the effect of BPA on sperm functions, fertilization and to evaluate their association with the activity of fertility related proteins in spermatozoa. We used a comprehensive in vitro test system to evaluate the effect of various concentrations of BPA (0.0001, 0.01, 1, and 100 μM) on mouse spermatozoa following 6 h of incubation. Our results showed that high concentration of BPA inhibited sperm motility and motion kinematics by significantly decreasing ATP levels in spermatozoa. Simultaneously, exposure of spermatozoa to high concentrations of BPA increased the tyrosine phosphorylation of sperm proteins involved in PKA-dependent regulation and induced a robust AR, ultimately results in poor fertilization and compromised embryonic development. Finally, BPA effects on selected group of fertility related proteins in spermatozoa, such as it degraded the β-actin, whereas the levels of peroxiredoxin-5, glutathione peroxidase, glyceraldehyde-3-phosphate dehydrogenase, and succinate dehydrogenase were increased. Based on these results, we propose that high concentration of BPA may alter overall sperm functions, fertilization and embryonic development, in association with degradation and/or phosphorylation of fertility related proteins in spermatozoa.