• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.2
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• pp.158-164
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• 2008

Purpose : Recently, various materials were developed for enhancing bone formation capacity. Platelet rich plasma(PRP) is an autologous source with several growth factors and obtained by sequestering and concentrating platelets by gradient density centrifugation. This study was to evaluate the effect of PRP on healing of grafted bone. Materials and methods : Two blood samples were obtained and analysed for measuring platelet counts of normal blood and PRP. In experimental group, two defects of mandibular bone, 10mm in diameter and 4.0mm deep, were created in the mandible and immediately grafted with autogenous bone chips mixed with PRP. In control group, same bone defects were prepared and grafted with autogenous bone chips. Gelform was used for carrier of PRP. 2 weeks, 4 weeks, 8 weeks later, each group was evaluated with histologi-cal and histomorphometric analyses. Results : According to histological observation, experimental group was showed more anastomosing newly-formed woven bone having osteoblastic activation than control group. According to histomorphometric analysis, there were 9.11% more newly-formed bone volume in experimental group than control group at 2 weeks, 7.91% more at 4 weeks, 20.08% more at 8 weeks. Conclusion: Our results demonstrated PRP in autogenous bone graft could enhance the bone formation.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.8
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• pp.813-821
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• 2005

This paper presents a modeling study of thermal dynamics and turbid current in the Obong Lake, Kangreung. The lake formed by the artificial dam in 1983 for agricultural water supply, is currently under consideration of reconstruction in order to expand the volume of reservoir for water supply and flood control in downstream area. The US Army Corps of Engineers' CE-QUAL-W2, a two-dimensional laterally averaged hydrodynamic and water quality model, was applied to the lake after reconstruction as well as the present lake. The model calibration and verification were conducted against surface water levels and temperature of the lake measured during the years of 2001 and 2003. The model results showed a good agreement with fold measurements both in calibration and verification. Utilizing the validated model, an impact of dam reconstruction on vertical temperature and hydrodynamics were predicted. The model results showed that steep temperature gradient between epilimnion and hypolimnion would be formed during summer, along with extension of cold deep water after reconstruction. During winter and spring seasons, however, the vertical temperature profiles was predicted to be quite similar both before and after reconstruction. This results indicated that thermal stratification would become stronger during summer and stay longer after dam reconstruction. From the examination of predicted water movements, it was noticed that the upstream turbid current would infiltrate into the interface between metalimnion and hypolimnion and then suspended solids would slowly settle down to the bottom before reconstruction. After reconstruction, however, it was shown that the upstream turbid current would stay longer in metalimnion with similar density due to strong stratification. The model also predicted that dam reconstruction would make suspended solids near the dam location significantly decrease.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.4
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• pp.445-456
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• 1997

We previously reported that some components of ginsenosides decreased mediator releases evoked by the activation of mast cells with specific antigen-antibody reactions. This study aimed to assess the effects of ginsenosides ($Rb_2$, Re) on the mechanism of histamine release in the mast cell activation. We partially purified guinea pig lung mast cells by using enzyme digestion, the rough and the discontinuous percoll density gradient method. Mast cells were sensitized with $IgG_1$ and challenged with ovalbumin (OA). Histamine was assayed by fluorometric analyzer, leukotrienes by radioimmunoassay. Phospholipase D (PLD) activity was assessed more directly by the production of $[^3H]phosphatidylbutanol$ (PBut) which was produced by PLD-mediated transphosphatidylation in the presence of butanol. The amount of 1,2- diacylglycerol (DAG) were measured by the $[^3H]DAG$ labeled with $[^3H]palmitic$ acid or $[^3H]myristic$ acid. Pretreatment of $Rb_2$ ($300\;{\mu}g$) significantly decreased histamine release by 60%, but Re ($300\;{\mu}g$) increased histamine release by 34%. Leukotrienes release in $Rb_2$ was decreased by 40%, Re was not affected in the leukotrienes release during mast cell activations. An increasing PLD activity during mast cell activation was decreased by the dose-dependent manner in the pretreatment of $Rb_2$, but Re pretreatment facilitated the increased PLD activity during mast cell activation. The amount of DAG produced by phospholipase C (PLC) activity was decreased by $Rb_2$ pretreatment, but Re pretreatment was not affected. The amount of mass DAG was decreased by $Rb_2$ and Re pretreatment during mast cell activation. The data suggest that $Rb_2$ purified from Korean Red Ginseng Radix inhibits the DAG which is produced by the activation of mast cells with antigen-antibody reactions via both phosphatidylinositide-PLC and phosphatidylcholine-PLD systems, and then followed by the inhibition of histamine release. However, Re increases histamine release by stimulation of DAG production, which is mediated by phosphatidylcholine-PLD system rather than by phosphatidylinositide-PLC system, but inhibits the mass DAG production. Thus, it could be inferred that other mechanisms play a role in the increase of histamine release during mast cell activation.

• Korean Journal of Veterinary Research
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• v.24 no.1
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• pp.40-49
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• 1984

To investigate the factors influencing the artifical transformation in Escherichia coli, E. coli C600 was transformed by pBR322 DNA with tetracycline and ampicillin resistant gene purified by CsCl-Etbr equilibrium density gradient centrifugation from E.coli HB 101. The influencing factors in the transformation such as concentration of calcium chloride, time of ice incubation, temperature and time of heat shock, time of gene expression, effects of plasmid DNA concentration and adding time were examined in these experiments. The results obtained were as follows; 1. The highest transformation frequency was observed in the treatments of 100 mM $CaCl_2$ before heat shock and the treatment of $CaCl_2$ was essential step in the process of E. coli transformation. 2. The highest transformation frequency was observed in the treatment of heat shock at $42^{\circ}C$ for 4 min. or $37^{\circ}C$ for 6 min., but the prolonged heat shock resulted a decreased transformation frequency. 3. Treatments of ice incubation at $0^{\circ}C$ for 45 min. before heat stocks or at $0^{\circ}C$ for 30min. after heat shock resulted an increased transformation frequency. 4. There was a linear relationship between DNA concentration and transformation frequency at the concentration of $8{\times}10^3$ recipient cells. The highest transformation frequency reached in carte of 7 mcg of donor DNA, but above 1 mcg of DNA concentration, transformation frequency was not remarkably increased. Addition of donor DNA just after the treatment of $CaCl_2$ was the best. 5. The best condition of gene expression at $37^{\circ}C$ were 40min. for TC-resistant gene and 100min. for AP-resistant gene. TC-resistant gene was higher in the transformation frequency and faster in the gene expression time than AP-resistant gene. In these results, the best conditions for the transformation of E. coli C 600 with pBR322 DNA were: treatment with 100mM $CaCl_2$, ice incubation at $0^{\circ}C$ for 45 min, heat shock at $42^{\circ}C$ for 4 min., 30 min. of ice incubation and incubation at $37^{\circ}C$ for 100min. for gene expression in that order.

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.99-106
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• 2001

This study was undertaken to compare the efficiency of recovery rate and development rate of follicular oocytes collected either by aspiration or by slicing method. The follicular oocytes collected by the two methods matured in TCM199 supplemented with 10% steer serum at 39$^{\circ}C$ in a humidified atmosphere of 5% $CO_2$in air. After 22 h of culture, the oocytes were inseminated with frozen-thawed semen (2$\times$10$^{6}$ sperm/ml of final concentration) prepared with Percoll-density gradient in IVF-TALP medium for 16 h. Later, sets of 15 presumptive zygotes were transferred into 50 $\mu$L, droplets of CR1aa medium. On day 4 of the culture, embryos were transferred to TCM199 until day 9. The percentages of nuclear maturation to pre-metaphase II in the oocytes collected by aspiration are significantly (P<0.05) higher than that by slicing (83% vs. 62%, respectively). The mean number of oocytes recovered by slicing per ovary is significantly (P<0.05) higher than that by aspiration (15.1 vs. 6.7, respectively). Although the rates of cleavage and development to blastocyst of oocytes collected b)\\\\`aspiration are significantly (P<0.05) higher than that by slicing, the number of transferable embryos obtained by slicing method is significantly (P<0.05) higher than that by aspiration. From the results. we may conclude that slicing method is better than aspiration method for obtaining large number of transferable embryos per ovary.

• Journal of Veterinary Clinics
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• v.27 no.1
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• pp.1-5
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• 2010

Enterocytozoon bieneusi, a microsporidian species, has emerged as an opportunistic pathogen in AIDS patients. This organism has also been identified in a wide range of animals, and the zoonotic potential of human infections is of particular interest. This study revealed that this organism was found with relatively high prevalence in feces of asymptomatic cattle in Korea. Fecal specimens were obtained from a total of 1,720 cattle in a slaughterhouse located in Chungnam province, Daejeon city and Chonbuk province. After removal of fecal debris by sieving and density gradient centrifugation, samples were examined by microscopic examination and then nested polymerase chain reaction (PCR). Microscopic examination with the modified trichrome staining for the fecal specimens revealed 194 (11.28%) positive calves for microsporidia spore. PCR using the specific primer for E. bieneusi revealed 79 (4.59%) positive calves. The infection ratio of microsporidia was higher in March than other season.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.1-6
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• 2015

The term "P2 sir-associated helper inefficiency" has been used to define the inefficient helper capability of P2 sir mutants for their satellite bacteriophage P4. The aim of this study was to investigate the factors overcoming P2 sir-associated helper inefficiency. At first, we verified whether the P2 cos region containing P4 sid71 cosP2 could overcome P2 sir-associated helper inefficiency with P2 sir3. The result was that P4 sid71 cosP2 could not overcome P2 sir-associated helper inefficiency with P2 sir3. Instead of cos region of P2, the size of the DNA packaged into a $P2_{sir}$-sized head seems to be important for overcoming P2 sir-associated helper inefficiency. In the present work, three kinds of P4 derivatives with packaged DNA sizes between those of P4 ost1 and P4 ost2, were constructed through DNA manipulation. In one P4 derivative, P4 sid71 delRI::apr, the size of the packaged DNA was identified with a CsCl buoyant equilibrium density gradient experiment. According to the burst sizes of the P4 derivatives, they could overcome P2 sir3-associated helper inefficiency. The size of the P4 derivative DNA suitable for packaging into a $P2_{sir3}$-sized head was 28-29 kb.

• Magazine of the Korean Society of Agricultural Engineers
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• v.25 no.4
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• pp.50-60
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• 1983

305 samples of alluvial deposit in inland and harbour districts were selected and consolidation charateristics of the alluvium were put in order statiscally. The correlations between them were as follows. 1. The relationships between LL(liguid limit) and Cc (compression index) were explained as Cc=0. 03(LL-21. 7) in case of inland district soil and as Cc=0. 019(LL-19) in case of harbour district soil. As compared with formular proposed by Skernpton, the gradient of this linear line was slight steep. 2. The relationships between PI(plastic index) and Cc were explained as Cc=0. 063 PI-0. 52 in case of inland district soil and Cc=0. 043 PI-0. 31 in case of harbour district soil. 3. As void ratio and natural moisture content were increased, Cc was increased, and as wet density was increased, Cc was decreased with a gentle curve. 4. As LL and P1 increased, mv(coefficient of volume compressibility) was increased but if LL and P1 was increased beyond a certain extend, mv has a tendency of constant value, that is, mv show a tendency to take constant value in the very soft clay. and mv in P=2. 5kg/cm$^2$ was about l${\times}$ l0-$^1$cm$^2$/kg in case of land district soil and 6x 10-$^1$crn$^2$/kg in case of harbour district soil lower than that in P=0. 25kg/crn2. 5. Cv(coefficient of consolidation) was a tendency to decrease with a gentle curve as LL was increased, and Cv in P=0. 25kg/crn2 was about 3x l0-$^1$crn$^2$/min larger than that in P=2. 5kg/crn$^2$. 6. Relationships between Py(pre-consolidation pressure) which is included over consolidation soil and ∑r1h(effective over-burden pressure) were explained as Py=l. 12 ∑r'h in case of land district soil and as Py=l. l5∑r'h in case of harbour district soil. 7. Some of the properties show good correlations between them, practical and effective applications of these correlations are expected in the planning and excution of soil investigation and also in the evaluation of the results.

• Journal of Pharmacopuncture
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• v.20 no.1
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• pp.52-56
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• 2017

Objectives: Neutrophils represent the front line of human defense against infections. Immediately after stimulation, neutrophilic enzymes are activated and produce toxic mediators such as pro-inflammatory cytokines, nitric oxide (NO) and myeloperoxidase (MPO). These mediators can be toxic not only to infectious agents but also to host tissues. Because flavonoids exhibit antioxidant and anti-inflammatory effects, they are subjects of interest for pharmacological modulation of inflammation. In the present study, the effects of rutin on stimulus-induced NO and tumor necrosis factor $(TNF)-{\alpha}$ productions and MPO activity in human neutrophils were investigated. Methods: Human peripheral blood neutrophils were isolated using Ficoll-Hypaque density gradient centrifugation coupled with dextran T500 sedimentation. The cell preparations containing > 98% granulocytes were determined by morphological examination through Giemsa staining. Neutrophils were cultured in complete Roswell Park Memorial Institute (RPMI) medium, pre-incubated with or without rutin ($25{\mu}M$) for 45 minutes, and stimulated with phorbol 12-myristate 13-acetate (PMA). Then, the $TNF-{\alpha}$, NO and MPO productions were analyzed using enzyme-linked immunosorbent assay (ELISA), Griess Reagent, and MPO assay kits, respectively. Also, the viability of human neutrophils was assessed using tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), and neutrophils were treated with various concentrations of rutin ($1-100{\mu}M$), after which MTT was appended and incubated at $37^{\circ}C$ for 4 hour. Results: Rutin at concentrations up to $100{\mu}M$ did not affect neutrophil viability during the 4-hour incubation period. Rutin significantly decreased the NO and $TNF-{\alpha}$ productions in human peripheral blood neutrophils compared to PMA-control cells (P < 0.001). Also, MPO activity was significantly reduced by rutin (P < 0.001). Conclusion: In this in vitro study, rutin had an anti-inflammatory effect due to its inhibiting NO and $TNF-{\alpha}$ productions, as well as MPO activity, in activated human neutrophils. Treatment with rutin may be considered as a therapeutic strategy for neutrophil-mediated inflammatory/autoimmune diseases.

• The Korean Journal of Mycology
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• v.17 no.2
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• pp.91-98
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• 1989

Mitochondria in the L. edodes was separated and purified by stepped sucrose density gradient centrifugation. The activity of mitochondrial ATP synthase has been investigated during various illumination times at each wavelength within the range of 400 nm to 700 nm. The stimulation of above activity increased by two times compared with nonilluminated control group when the illumination was given for 15 seconds at 470 nm wavelength. The optimal pH and temperature of this light-induced mitochondrial ATP synthase were 7.5 and $54^{\circ}C$, respectively. The activity of this enzyme increased by 26%, 25% and 14%, respectively, when there were 1 mmole $Fe^{3+}$, 0.5 mmole $Fe^{2+}$, and 5 mmole ${SO_4}^{2-}$ ion, and was inhibited by 5 mmole $Co^{2+}$, 5 mmole $Mn^{2+}$, 1 mmole $Ca^{2+}$, 0.1 mmole $Na^+$, 5 mmole $CN^-$, and 0.1 mmole ${CO_3}^{2-}$ ion. But $Na^+$ and $K^+$ ion did not affect the activity of enzyme.