• Title/Summary/Keyword: materials science

Search Result 32,572, Processing Time 0.064 seconds

Effect of Matrigel for Bone Graft using Hydroxyapatite/Poly $\varepsilon$-caprolactone Scaffold in a Rat Calvarial Defect Model (랫드의 두개골결손부 모델에서 HA/PCL 지지체를 사용한 골이식 시 Matrigel의 효과)

  • Kim, Se-Eun; Shim, Kyung-Mi;Kim, Seung-Eon;Choi, Seok-Hwa;Bae, Chun-Sik;Han, Ho-Jae;Kang, Seong-Soo
    • Journal of Veterinary Clinics
    • /
    • v.27 no.4
    • /
    • pp.325-329
    • /
    • 2010
  • The osteogenic potential of hydroxyapatite/poly $\varepsilon$-caprolactone composite (HA/PCL) scaffolds with matrigel was evaluated in a rat calvarial defect model. Calvarial defect formation was surgically created in Sprague Dawley rats (n = 18). HA/PCL scaffold was grafted with matrigel (M-HA/PCL group, n = 6) or without matrigel (HA/PCL group, n = 6). A critical defect group (CD group, n = 6) did not received a graft. Four weeks after surgery, bone formation was evaluated with radiography, micro computed tomography (micro CT) scanning, and histologically. No bone tissue formation was radiographically evident in the CD group. Bone tissue was radiographically evident in the HA/PCL and M-HA/PCL groups, however, there was more bone-similar opacity in the M-HA/PCL group. Micro CT analysis revealed that the bone volume of the M-HA/PCL group was higher than the HA/PCL group, however, no significant difference was found between the HA/PCL and M-HA/PCL groups. Bone mineral density in the M-HA/ PCL group was significantly higher than in the HA/PCL group (p < 0.05). Histologically, new bone was formed only from existing bone in the CD group, showing concavity without bone formation in the defect. In the HA/PCL group, new bone formation was only derived from existing bone, while in the M-HA/PCL group the largest bone formation was observed, with new bone tissue forming at the periphery of existing bone and around the HA/PCL scaffold with matrigel. The results indicate that the combination of HA/PCL scaffold with matrigel may be an effective means of enhancing bone formation in critical-sized bone defects.

Evaluation of Biocompatibility of Extracorporeal Circuit - Development of a Quantification Technique using in-vivo Injection of Tc99m Radioactive Platelets - (체외순환도관의 혈액적합성 평가 - 방사선 동위원소(Tc99m) 활성화 혈소판의 생체 내 주입을 이용한 정량분석법의 개발 -)

  • Lee, Sung-Ho;Sun, Kyung;Choi, Jai-Geol;Son, Ho-Sung;Jung, Jae-Seung;Ahn, Sang-Soo;Oh, Hye-Jung;Lee, Whan-Sung;Lee, Hye-Won;Kim, Kwang-Taik;Jeong, Yoon-Seop;Kim, Young-Ha;Kim, Hyoung-Mook
    • Journal of Chest Surgery
    • /
    • v.35 no.3
    • /
    • pp.171-176
    • /
    • 2002
  • Background: Blood-foreign interaction cause activation of coagulation and inflammatory process that may lead to multiorgan dysfunction and determine the surgical outcomes. Of the methods for assessing the biocompatibility, the platelet adhesion study is considered as the most valuable evaluation step in blood-foreign interaction. As the most studies have used in-vitro or ex-vivo conditions, we have developed a technique of quantification for platelet adhesion on the blood contact surface by using in-vivo injection of radioactive platelets. Material and Method: A coupled bypass circuit was designed to connect the proximal and descending thoracic aorta in 6 piglets(20∼25 Kg). One side of the circuit tube was consisted of a heparin coated PVC tube(10mm in ID, n=6, Experimental group), and the other, a non-heparin coated PVC tube(10mm in ID, n=6, Control group). After cannulation, the blood was circulated through the circuit for 2 hours. Platelet concentrate was prepared from homologous pig blood 24 hours before the experiment. The platelet concentrate was incubated with Tc-99m-HMPAO for 30 min and then centrifuged for 10 min. The supernatant was discarded and the radio-labeling efficacy was measured. The radio-labeled platelet concentrate was mixed with the autologous plasma to make the volume 5 ml, and the mixture was injected intravenously into the experimental animal. After 2 hour circulation, 5 pieces of the specimen(10mm in length each) were obtained from each PVC tube. The radioisotopes were counted with a gamma counter(Cobra ll, Packard, USA), and the ratio of radioisotope count was compared between the control and experimental group. Result: The radioisotope count number was 537.3221.1 Ci/min in the control group and 311.1 184.5 Ci/min in the experimental group(p=0.0104). The ratio between the groups was 1 to 0.58 (p=0.004). Conclusion: In vivo quantification using technetium-99m-HMPAO labeled platelets is simple and reproducible in evaluating platelet adhesion on a foreign surface. We suggest this technique to be a useful tool for blood compatibility test.

Effects of Polyimide Passivation Layers and polyvinylalcohol Passivation Layers for Organic Thin-Film Transistors(OTFTs) (폴리이미드 패시베이션과 폴리비닐알콜 패시베이션 레이어 성막이 고성능 유기박막 트렌지스터에 주는 영향)

  • Park, Il-Houng;Hyung, Gun-Woo;Choi, Hak-Bum;Hwang, Sun-Wook;Kim, Young-Kwan
    • Journal of the Korean Vacuum Society
    • /
    • v.17 no.3
    • /
    • pp.195-198
    • /
    • 2008
  • In this paper, it was demonstrated that organic thin-film transistors (OTFTs) were fabricated with the organic passivation layer by vapor deposition polymerization (VDP) processing. In order to form polymeric film as a passivation layer, VDP process was also introduced instead of spin-coating process, where polymeric film was co-deposited by high-vacuum thermal evaporation from 6FDA and ODA followed by curing. In order to investigate by compared with different passivation layer, the other OTFTs is fabricated to passivation by Polyvinylalcohol using spincoating. We can see that two different ways of passivation layer affect electric characteristic of OTFTs. The initial electric characteristic of OTFTs before passivation such as field effect mobility, threshold voltage, and on-off current ratio are $0.24cm^2/Vs$, -3V, and $10^6$, respectively. Then after polyimide passivation layer, field effect mobility change from $0.24cm^2/Vs$ to $0.26cm^2/Vs$, threshold voltage from -3V to 1V and on-off current ratio from $10^6$ to $10^6$, respectively. In the case of polyvinylalcohol passivation, the initial electric characteristic of OTFTs before passivation such as field effect mobility, threshold voltage, and on-off current ratio are $0.13cm^2/Vs$, 0V, and $10^6$, respectively. Then after polyvinylalcohol passivation layer, field effect mobility changes from $0.13cm^2/Vs$ to $0.13cm^2/Vs$, threshold voltage from 0V to 2V, and on-off current ratio from $10^6$ to $10^5$, respectively.

The Situation of Genetic Exchange in Duroc Breed and Impacts on Genetic Evaluation (국내 듀록의 종돈장간의 교류현황과 유전능력평가에 미치는 효과)

  • Seo, Jae-Ho;Shin, Ji-Seob;Noh, Jae-Kwang;Song, Chi-Eun;Do, Chang-Hee
    • Journal of Animal Science and Technology
    • /
    • v.53 no.5
    • /
    • pp.397-408
    • /
    • 2011
  • The study was carried to identify the impact on nation-wide genetic evaluation and to obtain basic materials for the development of strategies in Swine Improvement Network Project (SINP). Data consisted of pedigree records of 235,511 and performance records of 70,747 for Duroc from 1987 to 2010 were collected by Korea Animal Improvement Association. Performance traits included three point back fat thickness (Shoulder, Belly, Waist), loin area, days to 90 kg and average daily gain. Exchange of genetic resources cross the breeding farms was not high, and furthermore the sizable farms which can accommodate genetic evaluation within the farm were scarce. Three data sets (individual farm evaluation: I, two sub-group evaluation: S, and whole eight farm evaluation: P) were used for genetic analysis. Genetic variances were larger in subordinate farms than in joiners farms for connectedness, and consequently the heritabilities were generally higher in subordinate farms than in joiner farms with I. The standard errors of heritability were small in the order of I, S and P. Estimated average inbreeding coefficients were 1.12%, 0.95% and 1.53% for joiner and subordinate group with S and population with P, respectively. The estimated correlations of breeding values with I and P were lowest. The correlations of breeding values with I and P for traits ranged 0.22 to 0.45 for moved parent animals and 0.24 to 0.72 for all animals. The results in the study suggest that nation-wide evaluation uses more pedigree information and improves accuracy. Furthermore SINP for connectedness could help to improve the accuracy of evaluation.

Clinical Characeristics of Intracordal Cysts (성대낭종의 임상적 특성)

  • Hong, Ki-Hwan;Park, Jung-Hoon;Kim, Won;Kim, Chang-Hyun
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
    • /
    • v.10 no.2
    • /
    • pp.164-169
    • /
    • 1999
  • Background and Objectives : The intracordal cysts are more increasingly diagnosed and treated due to advanced laryngeal stroboscopy and laryngeal microsurgical technique. The intracordal cysts are frequently misdiagnosed as vocal polyp or nodule The purpose of this study is to evaluate clinical features of intracordal cysts. Materials and Methods : In the present series, 83 cases of the intracordal cysts treated with laryngeal microsurgery are reported. The intracordal cysts are diagnosed preoperatively with indirect laryngoscopy, laryngeal endoscopy, laryngeal stroboscopy and confirmed with laryngeal microsurgical findings and biopsies. Results : Intracordal cysts are 83 of 1900 patients treated with laryngeal microsurgery(4.4%)-ductal cysts are 56 cases and epidermoid cysts are 27 cases. Intracordal cysts are more frequent in women, forties and the frequent site is an anterior third of the true vocal cord. With the indirect laryngoscopic examination, the ductal cysts are frequently misdiagnosed as vocal polyps or nodules but the epidermoid cysts are relatively easily diagnosed. The etiologic factors of the intracordal cysts are suspected as voice abuse and upper respiratory infection. The degree of postoperative voice satisfaction is similar to that of the vocal polyps. Conclusion : Intracordal cysts are frequently misdiagnosed as polyps or nodules, therefore preoperative stroboscopic findings and laryngeal microsurgical findings is important. An ideal treatment is to enucleate the cysts avoiding rupture of cyst and injury of lamina propria of the vocal cord.

  • PDF

Studies on Partition and Extraction Equilibria of Metal-Dithiocarbamate Complexes(II). Metal Complexes of Ammonium Pyrrolidine Dithiocarbamate (Dithiocarbamate 금속착물의 분배 및 추출평형(제2보). Ammonium Pyrrolidine Dithiocarbamate의 금속착물)

  • Lee, Jong-Sun;Choi, Jong-Moon;Choi, Hee-Seon;Kim, Young-Sang
    • Analytical Science and Technology
    • /
    • v.8 no.3
    • /
    • pp.321-334
    • /
    • 1995
  • Basic studies for the effective extraction of ammonium pyrrolidine dithiocarbamate(APDC) complexes of Co(II), Ni(II) and Cu(II) into a solvent have been performed. The maximum distribution ratio was appeared (log D=1.3543) at pH 2.0 and the partition coefficient was 2.489 in the extraction of $4{\times}10^{-5}M$ APDC itself into chloroform. From the UV/visible spectra of metal-chelates in aqueous and organic solutions, the pH to form stable 1:2 metal-ligand complexes were Co(II):5.0, Ni(II):8.0 and Cu(II):8.0, respectively and only 1 minute was enough to be partitioned into the chloroform. Besides, the partition and extraction equilibria of the complexes were investigated by back-extracting $10.0{\mu}g/ml$ metal-chelates from the solvent into an aqueous solution beacuse of their slight solubilities in the aqueous solution. The distribution coefficients and extractabilities were as follows : at pH 6.5~8.5 of the aqueous solution, log D=2.834 : E(%)=99.9% for $Co(PDC)_2$, at pH 11, log D=5.699 E%=100 for $Ni( PDC)_2$, and at pH 6.0, log D=2.025 : E(%)=99.1% for $Cu(PDC)_2$. And the extraction and formation constants were log $K_{ex}=9.671$ : log ${\beta}_2=6.938$ for $Co(PDC)_2$, log $K_{ex}=9.646$ : log ${\beta}_2=7.071$ for $Ni( PDC)_2$, and log $K_{ex}=9.074$ : log ${\beta}_2=7.049$ for $Cu(PDC)_2$, respectively. From these results, an optimum extraction procedure can be constructed for the separative concentration of trace metallic ions, and the quantitative determination of them in advanced materials and environmental samples will be expected without any influence of sample matrixes.

  • PDF

Autoradiographic Studies on the Inhibitory Effect of Dibutyryl Cyclic AMP on Mouse Oocyte Maturation in Vitro (Dibutyryl Cyclic AMP가 생쥐여포난자의 성숙에 미치는 억제효과에 관한 자기방사법적 연구)

  • Choi, Choon-Keun
    • Applied Microscopy
    • /
    • v.7 no.1
    • /
    • pp.21-43
    • /
    • 1977
  • This experiment was undertaken in order to localize the labeled dbcAMP (dibutyryl cyclic AMP) in oocytes whose development has been suppressed by cold dbcAMP for 6 or 19 hours in vitro. Mouse oocytes were obtained from the ovaries of 3-4 week old A strain female mice, by puncturing the Graafian follicles in the modified Krebs-Ringer bicarbonate salt solution under the dissecting microscope. Those oocytes which have intact germinal vesicle were cultured in the basic culture medium supplemented with 0.4% bovine serum albumin (BSA). Cultivation of the oocytes was carried out in a microtube developed by Cho (1974). The cultures were then incubated in a humidified 5% $CO_2$ incubator maintained at $37^{\circ}C$ for 6 or 19 hours (Donahue, 1968). DbcAMP was added to culture medium for a final concentration of 100ug/ml, and $^3H-dbc$ AMP (specific activity 13 Ci/mM) for a final concentration of $40{\mu}Ci/ml$ was also added to the medium. For electron microscopic autoradiography, those oocytes recovered from the culture were washed with phosphate buffer (pH 7.4), and immediately prefixed in a 2.5% glutaraldehyde overnight and postfixed for 2 hours at $4 ^{\circ}C$ in 1% osmium tetroxide in phosphate buffer with pH 7.4 (Palade, 1952). After fixation, the materials were dehydrated in graded alcohol series and embedded in Epon 812 mixture based on the standard procedures (Luft, 1961). The thin sections $600-700{\AA}$ thick were mounted on the grids of 200 meshes. The grids containing sections were coated with a nuclear emulsion Kodak NTB-3 and stored in a cold dark box (at $4^{\circ}C$) for 3 weeks. After exposure, the samples were developed with Kodak D-19 and stained with uranyl acetate and lead citrate. Routine observation was made with Hitachi HU-11E electron microsocope. The results of the observation were as followings: 1. It was found that the labeled dbcAMP penetrated the egg plasma membrane and dispersed at random in the cytoplasm. 2. It was also observed that most of the labeled dbcAMP was attached to microfibrillar lattices portion of the oocyte cytoplasm. There fore, it is presumed that the receptor of the dbcAMP is localized in the microfibrillar lattices of the oocyte. 3. It also seems that some other cell organells such as mitochondria, Golgi complex, cortical granules are not directly related to the action of the dbcAMP. 4. The labeled dbcAMP was neither observed in the membrane nor in the nucleus. Therefore, it seems that there is no relationship between the concentration of dbcAMP and the nuclear membranous permeability. 5. There was no difference in number of dbcAMP particles when oocytes were cultured for 6 hours and 19 hours. 6. However, it was observed that, in same of the oocytes suppressed in germinal vesicle by dbcAMP for 19 hours, cell organells were moved and concentrated to a small portion of the cytoplasm, and that the morphology of the organells greatly changed to an abnormal. form. Therefore, it is supposed that those oocytes were in the process of degeneration. From the above results, it is expected that dbcAMP penetrated the egg membrane and was bound to the receptor which seems to be located in the microfibrillar lattiees portion, and that this dbcAMP-receptor complex inhibited some enzyme system of the oocytes which are essential for the germinal vesicle breakdown.

  • PDF

Bactericidal Efficacy of Fumagari OPP®, Fumigant Against Staphylococcus aureus (훈증소독제, Fumagari OPP®의 Staphylococcus aureus에 대한 살균효과)

  • Cha, Chun-Nam;Park, Eun-Kee;Choi, Hyunju;Kim, Yongpal;Yoo, Chang-Yeol;Kim, Suk;Lee, Hu-Jang
    • Journal of Food Hygiene and Safety
    • /
    • v.28 no.4
    • /
    • pp.349-353
    • /
    • 2013
  • This study was performed to evaluate the bactericidal efficacy of Fumagari OPP$^{(R)}$, fumigation disinfectant, containing 20% ortho-phenylphenol against Staphylococcus aureus (S. aureus). In this research, efficacy test of fumigant against S. aureus was carried out according to French standard NF T 72-281. S. aureus working culture suspension number (N value), all of the colony numbers on the carriers exposed with the fumigant (n1, n2, and n3), the number of bacterial test suspentions by pour plate method (N1), the number of bacterial test suspentions by filter membrane method (N2) and the mean number of bacteria recovered on the control-carriers (T value) were obtained from the preliminary test. In addition, the reduction number of S. aureus exposed with the fumigant (d value) was calculated using T value, the mean number of bacteria in recovery solution (n'1) and the mean number of bacteria on carriers plated in agar (n'2). N value was $4.0{\times}10^8$ CFU/mL, and n1, n2, and n3 were higher than 0.5N1, 0.5N2 and 0.5N1, respectively. Additionally, T value was $3.4{\times}10^6$ CFU/mL. In the bactericidal effect of the fumigant, the d value was 6.43 logCFU/mL. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. The results indicated that Fumagari OPP$^{(R)}$ had an effective bactericidal activity against S. aureus, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with pathogenic bacteria.

Studies on the Reproductive Cycle of Damselfish, Chromis notatus (Temminck et Schlegel) (자리돔의 생식주기에 관한 연구)

  • LEE Young Don;LEE Taek Yuil
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.20 no.6
    • /
    • pp.509-519
    • /
    • 1987
  • Annual reproductive cycle of the Damselfish, Chromis notatus collected monthly at the four coastal areas around Chejudo, Korea are studied on the bases of histological observations of gonadal tissue and various quantitative variables including gonadosomatic index (GSI), fatness, egg diameter composition and the first maturity. The ovary consisted of a pair of saccular structure with many ovarian sacs. Oogonia proliferated along the germinal epithelium of the ovarian sac. Young oocytes with basophilic cytoplasm showed several nucleoli along the nuclear membrane. When the oocytes reached about $450{\mu}m$ in diameter, nucleus migrate toward the animal pole, nuclear membrane disappeared and most of cytoplasm were filled with yolk materials and oil drops. After ovulation, residual follicle and growing oocytes remaining in the ovarian sacs degenerated. But early young oocytes without follicle layer were not degenerated, and growing continuously till the next year. The testis consisted of a pair of lobular structures in the right and left were united in the posterior seminal vesicle. Cortex of testis was composed of many sperm ducts connected with lobuli. GSI began to increase from March, starting season of longer day length and higher water temperature, and reached the maximum value between June and August. It began to decrease from September with the lowest value appearing between October and February without any evident variation. The annual reproductive cycle could be devided into five successive stage : growing(April to Many), mature(May to August), ripe and spent (June to August) and recovery and resting stage(September to March). The spawning peak occurred from June to August. According to the frequency distribution of egg diameter, Chromis notatus was a polycyclic species to spawn twice or more in a spawning season. Fatness, correlated with gonadal phases, was remarkably decreased by spawning. Percentage of the first maturity . in femate and male fish ranging from 7.0 to 7.9 cm were $50\%$ and from 9.0 to 9.9 cm in total length $100\%$.

  • PDF

A Study on the Change in the Representation of Father Involvement in Home Economics Textbook (가정과 교과서에 나타난 아버지 역할의 변화)

  • Kim, Youn-Jung;Lee, Soo-Hee;Sohn, Sang-Hee
    • Journal of Korean Home Economics Education Association
    • /
    • v.26 no.2
    • /
    • pp.31-49
    • /
    • 2014
  • The purpose of this study is to examine how the father involvement suggested in the Home Economics textbook through the development of gender-equal society and provide the basic data for the development of a standard for the father involvement in the viewpoint of gender equality. For this, the father involvement depicted in the main text, photos, and illustrations included in the Home Economics textbooks were examined. A total of 34 Home Economics textbooks written based on the curricula from the 1st Curriculum up to the 2007 Revised Curriculum were analyzed centering on the contents and the quantity of the text, supplementary materials, photos, and illustrations. The following are the results of the analysis. First, the Home Economics textbooks based on the 1st to 3rd Curriculua only described the traditional father involvement, and photos and illustrations did not specifically describe the role of the father. Second, the Home Economics textbooks based on the 4th to 5th Curricula began to show changes such as the image of the father sharing household responsibilities. Third, the Home Economics textbooks based on the 6th Curriculum suggested more active involvement of the father such as sharing the equal responsibility for the upbringing of children and sharing responsibilities for child care and housework. Fourth, the Home Economics textbooks based on the 7th Curricula up to the Revised Curriculum of 2007 emphasized the father's involvement of upbringing children. Especially, a variety of contents including the domestic responsibilities of the father, the correction of the "work-first" attitude, and gender equality related contents were suggested to promote gender-equal society further. Said results show that the contents related with gender equality and the descriptions about the father role in the viewpoint of gender equality are steadily increasing in Home Economics textbooks. However, there were still problems such as the gender-role division regarding the involvement of the father in the family and temporary responses to social demands. Open debates between the experts in the education of Home Economics and experts in family life may be required in order to improve said problems.

  • PDF