• 제목/요약/키워드: Nuclear morphology

검색결과 344건 처리시간 0.023초

난자의 형태와 난소의 보존 및 채취시기가 고양이 난자의 체외발생에 미치는 영향에 관한 연구 (Study on the Effects of Morphology, Preservation and Reproductive Cycle of In Vitro Developmental Rate of Cats Oocytes)

  • 전연화;이명헌;김상근
    • 한국수정란이식학회지
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    • 제18권2호
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    • pp.109-113
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    • 2003
  • 본 연구는 고양이의 불임 해결을 위한 방안의 하나로써 체외수정란을 생산할 목적으로 난자의 형태, 보존 및 번식주기별 난자의 체외발생에 미치는 영향을 조사하였다. 1. 신선 난소로부터 회수한 난구세포부착 및 나화 난자를 각각 배양했을 때 GV 및 MI으로의 체외성숙율은 74.3%와 25.7%와 및 28.6%와 11.4%,로써 난구세포 부착 난자가 나화 난자의 비해 높은 체외성숙율을 나타냈다. 2. 휴지기, 난포기 및 황체기 단계로 구분하여 채취한 난구세포 부착 난포란을 배양하였을 때 GV 및 MI기로의 체외성숙율은 각각 88.6%와 6.5%, 60.0%와 11.4%, 77.1%와 5.7%였다. 3. 신선 및 salt에 보존한 난소로부터 회수한 난구세포부착 및 나화 난자를 각각 배양했을 때 GV 및 MI으로의 체외성숙율은 74.3%와 25.7%, 37.1%와 11.4% 및 57.1%와 13.3%, 17.1%와 3.3%으로서 난구세포 부착 신선난자가 나화 또는 salt 보존 난자에 비해 높은 체외 성숙율을 나타냈다.

Optimization and modification of PVDF dual-layer hollow fiber membrane for direct contact membrane distillation; application of response surface methodology and morphology study

  • Bahrami, Mehdi;Karimi-Sabet, Javad;Hatamnejad, Ali;Dastbaz, Abolfazl;Moosavian, Mohammad Ali
    • Korean Journal of Chemical Engineering
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    • 제35권11호
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    • pp.2241-2255
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    • 2018
  • RSM methodology was applied to present mathematical models for the fabrication of polyvinylidene fluoride (PVDF) dual-layer hollow fibers in membrane distillation process. The design of experiments was used to investigate three main parameters in terms of polymer concentration in both outer and inner layers and the flow rate of dope solutions by the Box-Behnken method. According to obtained results, the optimization was done to present the proper membrane with desirable properties. The characteristics of the optimized membrane (named HF-O) suggested by the Box-Behnken (at the predicted point) showed that the proposed models are strongly valid. Then, a morphology study was done to modify the fiber by a combination of three types of a structure such as macro-void, sponge-like and sharp finger-like. It also improved the hydrophobicity of outer surface from 87 to $113^{\circ}$ and the mean pore size of the inner surface from 108.12 to 560.14 nm. The DCMD flux of modified fiber (named HF-M) enhanced 62% more than HF-O when it was fabricated by considering both of RSM and morphology study results. Finally, HF-M was conducted for long-term desalination process up to 100 hr and showed stable flux and wetting resistance during the test. These stepwise approaches are proposed to easily predict the main properties of PVDF dual-layer hollow fibers by valid models and to effectively modify its structure.

Effects of Roscovitine on Nuclear Maturation, Spindle Configuration, and Chromosome Alignment in Porcine Oocytes

  • Park, Sang-Hyoun;Yu, Il-Jeoung
    • 한국수정란이식학회지
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    • 제25권4호
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    • pp.251-258
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    • 2010
  • In the present study, effects of concentration and time of culture in presence of roscovitine on nuclear maturation and meiotic spindle configuration, chromosomal alignment were examined in porcine oocytes. In experiment 1, porcine cumulus oocyte complexes (COCs) were cultured at $39^{\circ}C$ in a 5% $CO_2$ atmosphere in North Carolina State University 23 (NCSU-23) supplemented with 25, 50, 75 or $100\;{\mu}M$ roscovitine for 22 h and then were cultured for additional 22 h after removal of roscovitine. Nuclear maturation and morphology of the meiotic spindle and chromosomal alignment were examined to determine the optimal concentration of roscovitine in oocyte maturation. In experiment 2, COCs were cultured in NCSU-23 supplemented with $50\;{\mu}M$ roscovitine for 17, 20, 27 or 42 h and then an additional 22 h without roscovitine was followed to determine the optimal time of culture. The optimal concentration of roscovitine to arrest and resume meiosis of porcine oocyte was $50\;{\mu}M$ by examining nuclear status (p<0.05) and normal spindle and chromosome configuration. The optimal time of culture in presence of roscovitine to arrest meiosis of porcine oocyte was 17 h (p<0.05), although MII rates and normal morphology of the meiotic spindle and chromosomal alignment were not significantly different among various times of culture. In conclusion, the optimal concentration and time of culture in presence of roscovitine to arrest porcine oocytes are $50\;{\mu}M$ and 17 h, respectively.

Removal of Strontium Ions by Immobilized Saccharomyces Cerevisiae in Magnetic Chitosan Microspheres

  • Yin, Yanan;Wang, Jianlong;Yang, Xiaoyong;Li, Weihua
    • Nuclear Engineering and Technology
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    • 제49권1호
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    • pp.172-177
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    • 2017
  • A novel biosorbent, immobilized Saccharomyces cerevisiae in magnetic chitosan microspheres was prepared, characterized, and used for the removal of $Sr^{2+}$ from aqueous solution. The structure and morphology of immobilized S. cerevisiae before and after $Sr^{2+}$adsorption were observed using scanning electron microscopy with energy dispersive X-ray spectroscopy. The experimental results showed that the Langmuir and Freundlich isotherm models could be used to describe the $Sr^{2+}$ adsorption onto immobilized S. cerevisiae microspheres. The maximal adsorption capacity ($q_m$) was calculated to be 81.96 mg/g by the Langmuir model. Immobilized S. cerevisiae was an effective adsorbent for the $Sr^{2+}$ removal from aqueous solution.

Effect of octadecylamine concentration on adsorption on carbon steel surface

  • Liu, Canshuai;Lin, Genxian;Sun, Yun;Lu, Jundong;Fang, Jun;Yu, Chun;Chi, Lisheng;Sun, Ke
    • Nuclear Engineering and Technology
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    • 제52권10호
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    • pp.2394-2401
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    • 2020
  • Octadecylamine is an effective film-forming amine that protects carbon steel from corrosion. In the present study, the effect of octadecylamine concentration on adsorption on a carbon steel surface was investigated in anaerobic alkaline solution by using SEM/EDS, TEM and the Materials Studio simulation techniques. TEM morphology observation and EDS elemental detection determine the thicknesses of octadecylamine film on a carbon steel surface, which are confirmed by the in-situ electrochemical impedance spectroscopy measurement and resistance calculation. The Materials Studio simulation reveals the number of octadecylamine film layers at different concentrations. Results obtained in this study indicate that adsorption of octadecylamine film on carbon steel proceeds with the multi-layer adsorption mechanism.

Transgenesis and Nuclear Transfer Using Porcine Embryonic Germ Cells

  • Ahn, Kwang-Sung;Yoon, Ji-Young;Yang, Hong-Seok;Hosup Shim
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2004년도 춘계학술발표대회
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    • pp.192-192
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    • 2004
  • Embryonic germ (EG) cells are undifferentiated stem cells isolated from cultured primodial germ cells (PGC). These cells share many characteristics with embryonic stem cells including their morphology and pluripotency. Undifferentiated porcine EG cell lines demonstrating capacities of both in vitro and in vivo differentiation have been established. (omitted)

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New records of terrestrial and freshwater ciliates (Protozoa: Ciliophora) from Korea: Brief descriptions with notes

  • Moon, Ji Hye;Park, Mi-Hyun;Jung, Jae-Ho
    • Journal of Species Research
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    • 제6권spc호
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    • pp.1-7
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    • 2017
  • Eight samples, collected from six moss-covered soil and two freshwater samples, were examined to determine ciliate diversity in Korea. Based on the morphology of living and stained specimens, thirteen ciliate species, previously unrecorded in Korea, were identified. These specimens were classified to four classes, seven orders, ten families, and twelve genera. Of these genera, the following six were first records in Korea: Bresslauides, Dexiotricha, Glaucoma, Paragastrostyla, Sathrophilus, and Trithigmostoma. Here, we provide a brief description of the morphology of these 13 taxa along with microphotographs and notes.

Reassessment of Cambaroides dauricus and C. schrenckii (Crustacea: Decapoda: Cambaridae)

  • Kawai, Tadashi;Machino, Yoichi;Ko, Hyun-Sook
    • Animal cells and systems
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    • 제7권3호
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    • pp.191-196
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    • 2003
  • Taxonomic confusion has been presented within freshwater crayfishes of the genus Cambaroides since Starobogatov published morphological definition and revision of the group in 1995. He suggested that Cambaroides should be revised: the C. dauricus, contained three species C. dauricus, C. wladiwostokiensis, and C. koshewnikowi; the C. schrenckii with two. species C. schrenckii and C. sachalinensis. Also Straovogatov did not take into account the previous data. of crayfish distributions. In order to. clear up the confusion, the taxonomy of crayfish sampled from Mongolia, Russia, China, and North Korea was reassessed. Starovogatov's key could not lead to the correct identification. Also, detailed observations of apical robe of the male first pleopod did not support the taxonomy on the genus Cambaroides proposed by Starobogatov in 1995. However, some local variations of morphology exist in rostrum, pleuron, and telson of Asian crayfish. Future studies should be concentrated on whether there are geographical clines of morphology or if taxonomic subdivision is necessary.