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        검색결과 115

        61.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        μ방lt emitting diodes (LED) devices are commercially introduced as an alternative for low-Ievellaser therapy (11ι,T) , and it has several advantages over lasers such as a safe, efficient, and less-expensive altemative to treat wounds. And LED irradiation at the same biostimulatory wavelength has similar bíochemical effεαs. In the present study, to asses whether the I핑ht-emitting diode (LED) irradíation can stimulate bone regeneration, irradiated bony defects with or without grafting materials on rat calvaria were compared to corresponding nonirradiated control. Fifty male Sprague-Dawly rats weighing about 150g, were used. Factors for present study were designed as follows, 1) presence or absence of grafting materials, 2) with or without irradiation, and 3) number of irradiation. Two weeks after operation, rats were sacrifìced. Radiologic and 비stomorphologic fmdings were evaluated. Macrospically, there were no incidents of infection, dehiscence, hematoma and necrosis during study. Radiological findings showed greater radiopacity in the graft group and radiopacity increased as the number of irradiation increase. And microscopically, new bαle formation was great in the graft group and increased as the number of irradiation increase, Present study has shown that LED irradiation improved bone regeneration through radiologic and histomorphologic fmdings in rat.
        4,000원
        64.
        2003.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 설폰기를 함유한 sulfosuccinic acid를 가교제로 사용하였다. 또한, 메탄을 투과도를 줄이기 위해 실리카를 졸-겔 방법을 사용하여 성장시킨 PVA/Silica 하이브리드막을 제조하여 수소 이온 전도도 및 메탄을 투과도에 관하여 연구하였다. 수소 이온 전도도 및 메탄을 투과도는 가교제 농도 및 친수성 SO3H의 함량에 영향을 받았으며, 제조된 막의 수소 이온 전도도는 10-3~10-2 S/cm 범위에 있었고, 메탄을 투과도는 10-8~10-7;cm2/s 를 갖는다.
        4,000원
        65.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        4-Nonylphenol (NP) is a surfactant that is a well-known and widespread estrogenic endocrine disrupting chemical (EDC). Although it has been known that the affinity of NP to ERs is low, it has been suggested that low-dose NP has toxicity. In the present study, the endocrine disrupting effects on reproduction, and the weight of gonads, epididymis, and uterus were evaluated with the chronic lower-dose NP exposing. This study was designed by following the OECD test guideline 443 and subjected to a complete necropsy. In male, NP had an effect on the weight of the testis and epididymis in both F0 and F1. In females, NP decreased the weight of ovary and uterus in F0 but not in pre-pubertal F1 pubs. Fertility of male and female in F0 or F1 was no related with NP administration. The number of caudal-epididymal sperm by body weight (BW) was not different between groups in both F0 and F1. Besides, the difference of the sperm number between generations was not detected. The number of ovulated oocytes was similar between groups in F0, but significantly decreased in NP 50 group of F1. The litter size and sex ratios of offspring in F1 and F2 were not different. The accumulated mating rate and gestation period were not affected by the NP administration. Those results shows that chronic lower-dose NP administration has an effect of endocrine disruptor on the weight of gonads and epididymis of F0 and F1 but not in reproduction. Based on the results, it is suggested that chronic lower-dose NP exposing causes endocrine disruption in the weight of gonad and epididymis but not in the reproductive ability of next generations.
        66.
        2017.05 서비스 종료(열람 제한)
        Background : Methicillin-Resistant Staphylococcus aureus (MRSA) is a multidrug-resistant (MDR) strain. Especially, MRSA is developing resistance to available antibacterial agents and causing complications in the treatment of infections related to skin, soft tissue, respiratory, bone, joint, and endovascular disorders. Therefore, antibacterial agent combination therapy appears to be a useful option, particularly in developing countries where antibiotic availability is limited. (+)-Usnic acid (UA) is uniquely found in lichens, and is especially abundant in genera such as Usnea and Cladonia. UA has antimicrobial activity against human and plant pathogens. Therefore, UA may be a good antibacterial drug candidate for clinical development. Methods and Results : In search of a natural products capable of inhibiting this multidrug-resistant bacteria, we have investigated the antimicrobial activity of UA against MRSA. In this study, the effects of a combination of UA and permeable agents against MRSA were investigated. For the measurement of cell wall permeability, UA with concentration of Ethylenediaminetetraacetic acid (EDTA) was used. In the other hand, Sodium azide (NaN3) was used as inhibitors of ATPase. These results suggest that the antibacterial effect of UA was potentiated by membrane-binding agents and ABC transporter-inhibiting agents, implying that antibacterial activity is associated with damage of the cell wall and inhibition of ATPase function by UA. Conclusion : UA and in combination with EDTA and NaN3 could lead to the development of new combination antibiotics against MRSA infection. The results of this study appear to be promising, and they are expected to enhance the use of natural products as drugs.
        67.
        2015.09 서비스 종료(열람 제한)
        To overcome the risk of the ovarian hyperstimulation syndrome (OHSS) in patients have polycystic ovarian syndrome (PCOS) and to prepare emergency fertility preservation in patients undergoing anticancer treatment, several researchers have reported IVM of oocytes retrieved from ovaries exposed by only hCG priming. However, the maturation rate and the developmental potential of embryos from IVM oocytes are significantly lower than those of oocytes matured in vivo. Here, we investigated the optimal time point for immature oocyte collection at post hCG only injection for in vitro maturation, in vitro fertilization and blastocyst formation. Immature GV oocytes were collected from 25 days old B6D2F1 female mouse at 12 hr, 14 hr, 16 hr or 24 hr post hCG injection. Oocytes were collected from antral or late secondary follicle by puncturing with 26 G needle. Collected oocytes were cultured in G2 medium with 10% FBS, FSH, estradiol, and hCG for 16 hr in vitro and subjected in vitro fertilization and further embryonic development. To examine follicular maturation, we estimated the numbers of primordial, primary, secondary follicle and antral follicle on ovaries of each time point post hCG. To confirm the optimal time point post hCG injection for collecting immature oocytes, we recovered the oocytes from each time point. There is no difference in the number of oocytes per mice. Oocytes collected at 14 hr post hCG injection were shown higher maturation rate to MII stage and blastocyst formation compare to other three groups (p<0.01). However, there is no difference in the maturation rate on the other three groups. Also, apoptotic signal with TUNEL assay or anti-PARP staining was not change in ovaries from all experimental groups. Granulosa cell proliferation test with anti Ki-67 or anti AMH was not show any difference. According to these results, there are no significant differences in four different time points at 12 hr, 14 hr, 16 hr or 24 hr of collection of immature oocytes in hCG primed mouse. However, oocytes from 14 hr post hCG injection showed higher percentages of maturation rate, in vitro fertilization rate, blastocyst formation.
        68.
        2015.09 서비스 종료(열람 제한)
        Cryopreservation has become a powerful method of the assisted reproduction technology and supports fertility preservation of cancer and other indication patients. After controlled ovarian hyperstimulation, surplus oocytes and embryos were recommended to store using cryopreservation. Recently, vitrification is replaced with traditional slow freezing protocol, because of improved survival rates and clinical outcomes. Vitrification requires a high concentration of CPAs that may induce significant osmotic and metabolic damage to cells including oocytes even in a short exposure of a few minutes. Generally, MPF plays a crucial role in the cell cycle regulation and maintaining the meiotic arrest of oocytes. In fact, it has been observed to decline in MII ovine oocytes after vitrification and would be suggested that one of the main causes of low fertilization rate and developmental competence derived from cryoinjury during vitrification. Therefore, the aim of this study was to evaluate the effect of caffeine treatment on the activity of MPF, MAPK level in vitrified/warmed mouse mature eggs. Caffeine, Phosphataseinhibitor, may maintain active form of MPF. We evaluated their survival after warming procedure, fertilization, cleavage, and developmental rates. Ovulated MII eggs were retrieved from 6 weeks old B6D2F1 female mouse at 14hr post hCG injection. Collected MII eggs were maintained in HTF medium containing 10% KSR with or without caffeine for 1hr. Eggs were vitrified in 7.5%EG +7.5%DMSO equilibrium solution, 15%EG + 15%DMSO + 0.5M sucrose vitrification solution with or without caffeine. Also warming solution contained sucrose (0.5M, 0.25M, 0.125M, and 0M) with or without caffeine. After warming, eggs were cultured in HTF medium with or without caffeine for 2 hr then fertilized with epididymal sperm in vitro and cultured in KSOM for 5 days to analyze embryonic development. Survival rates were similar in all experimental groups. However, fertilization rate was higher in with caffeine group compare to without caffeine significantly (80% vs. 85%, p<0.05). 2-cell and blastocyst formation were increased in caffeine group (p<0.05). MPF activity and MAP kinase activity were recovered in with caffeine group after vitrification/warming process. In conclusion, Caffeine may maintain MPF and MAPK level in vitrified/warmed MII eggs, and enhance fertilization and further embryonic development.
        69.
        2015.02 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to investigate the effects of the Cirsium japonicum var. ussuriense (C. japonicum)extract on serum level of hormones from induced osteoporosis by ovariectomized rats. Two month-old rats were ovariecto-mized (OVX), remained untreated for 8 weeks, and were subsequently administered C. japonicum (200㎎/㎏) every day for8 weeks. We examined the effects of treated C. japonicum on ovariectomy-related changes in Insulin-like Growth Factors(IGF), Insulin-like Growth Factor binding protein-3 (IGBF-3), Estrogen, Calcium, and Phosporus. After 8 weeks, the serumlevels of IGF-I, -II, and IGFBP-3 were higher presented as compared to the other two groups (P<0.05), in the C. japonicumextract treatment on OVX rats. There were differences between OVX and C. japonicum extract treated OVX rats in serumlevels of Ca2+, but Ca2+ levels for the normal group was higher than for the other two groups. The C. japonicum extractincreased both serum IGFs and IGFBP-3 levels on induced osteoporotic rat by ovariectomized. Thus, these results revealedthat the C. japonicum extract is a possible role for improvement of osteoporosis induced-ovariectomized rats and has a greatpotential as an alternative tool for the treatment of osteoporosis.
        70.
        2014.09 서비스 종료(열람 제한)
        Reactive oxygen species (ROS) are produced in organisms as the natural products of oxidative metabolism by environmental stress and pathogen invasion. ROS, such as superoxide anion and hydrogen peroxide, can be toxic to cells and tissues to cause oxidative stress. Recent study revealed that olive flounder (Paralichthys olivaceus) superoxide dismutase (SOD) has been identified as a partial gene and strongly induced to benzoin[a]pyrene and it was deduced indicator of aquatic oxidative stress responses, but its transcriptional response against viral infection has not been investigated. In the present study, spatial and temporal expression profile was analyzed to investigate the function of Of-SOD in the anti-viral response. Of-SOD transcripts were ubiquitously detected in diverse tissues with variable levels using a real-time PCR. The expression of Of-SOD was significantly higher in the muscle, liver and brain, but extremely low in the stomach and spleen. Following VHSV challenge, the expression of Of-SOD increased within 3 hours and subsequently decreased to the original level at 2 days post-challenge in kidney. Although expression pattern and induction time are slight differences depending on the tissue, the transcript of Of-SOD was consistently increased in acute infection response, but expression is low in the chronic response. Collectively, Of-SOD expressions were inducible after VHSV infection and they were probably involved in the immune response against viral challenge. These results suggest that SODs may play important roles in the immune defense system of P. olivaceus and perhaps contribute to the protective effects against oxidative stress in this flounder.
        71.
        2013.08 서비스 종료(열람 제한)
        Olive flounder (Paralichthys olivaceus) is a most important aquaculture species in Korea. Like most marine fishes, olive flounders are stomachless at first feeding and aquired gastric function during the metamorphosis, so food was mainly digested by pancreatic enzyme from first feeding to premetamorphosis. However, comprehensive analysis of pancreatic and gastric digestive enzyme of olive flounder at early developmental period is still unclear. In the expression study of pancreatic and gastric digestive enzyme by real-time PCR at early developmental stage, pancreatic enzyme such as chymotrypsinogen 2, preproelastase 2 and 4, pancreatic protein somatomedin-B domain (PPSB) mRNA expression were initiated at first feeding and strongly expressed in the pancreas developmental stage, while gastric digestive enzyme signal was not at all detected during same period. Although, trypsinogens were secreted from pancreas and have similar amino acid sequence, trypsinogen 3 expression induction was detected both pancreas and stomach developmental stage, while trypsinogen 2 expression was significantly increased only post-metamorphosis period. Pepsinogen mRNA expression was only detected at metamorphosis according to stomach differentiation. Lipid digestive enzyme, lipase and intestine fatty acid binding protein 1 (I-FABP 1), were already reached a certain level at beginning of hatching and more increased during early developmental stage and then gradually decreased before metamorphosis. These results suggested that feed ingestion of olive flounder was exclusive charged by pancreatic digestive enyme, lipid digestive enzyme and trypsinogen 3 from first feeding and then fully swiched by gastric digestive enzyme and trypsinogen 2 from metamorphosis period.
        72.
        2012.07 서비스 종료(열람 제한)
        Mutagenesis approach in combination with whole genome sequencing has become an import role in genetic and molecular biological study and breeding of crop plants. In this study, we screened the fast neutron M4 10,000 soybean mutant plants based on morphological phenotypes of agronomically important traits and characterized the mutant of interest using resequencing. Fast neutron radiation has been known to be a very effective mutagen to cause large deletion in genome. The screened mutant showed abnormal phenotypes in plant heights, seed sizes, color of leaves, number of leaves, maturity and number of branches etc. Among them, the mutant displaying short plant height and bush type of growth habit was selected for identification of the altered genomic regions. Analysis of deletion sites of genome in interesting soybean mutant was performed using next generation sequencer Illumina Hi-seq. Mutant sequence reads generated by paired-end shotgun library were mapped on a draft soybean reference soybean (G. max cv. Williams 82). The paired-end DNA sequences of 21.6 Gb produced by Illumina Hi-seq produced 21 fold sequence depth. Among the predicted deletion sites, total 3 deletion regions confirmed by PCR. Glyma03g02390 gene and Glyma03g03560 gene were involved in the deletion regions. Glyma03g02390 gene was related to AMP binding, catalytic activity, cofactor binding and metabolic process of cell growth and Glyma03g03560 gene was concerned to oxygen binding, defense response to bacterium, and especially process of indole acetic acid (IAA) biosynthesis. These genes detected in this mutant will be studied about their molecular function in stunted phenotype.
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