• Title/Summary/Keyword: 2-stage injection

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The Evaluation of Various Conditions in the Cryopreservation of Mouse Embryos - Rapid and Slow Method of Cryopreservation, Culture Media and Cell Stages (생쥐배아의 냉동보존에 있어서 여러 조건의 평가 - 저속 처리단계와 급속 처리단계, 배양액, 세포기)

  • Yi, Seung-Yeun;Kwon, Ju-Taek;Song, Hee-Won;Cho, Yun-Hee;Lee, Ky-Sook;Rheu, Cheul-Hee;Kim, Jong-Duk
    • Clinical and Experimental Reproductive Medicine
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    • v.26 no.2
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    • pp.127-135
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    • 1999
  • Cryopreservation is able to store the surplus pre-embryos for freezing and furthermore thawing and transfer in a subsequent cycle. Cryopreserving cells which are maintaining their viability are the very complex process. This study has been carried out in order to find the effects of cryopreservation steps, freezing media and embryonic stages on the rates of viability and development of cryopreserved mouse embryos. Female ICR mice ($6{\sim}8$ weeks old) were induced to superovulate by sequential intraperitoneal injection of 5 IU PMSG and 5 IU hCG 48h apart. Mouse embryos were collected according to its developmental stage after the injection of hCG. Embryos were cryopreserved not only by cryoprotectant step (1 step${\sim}$4 step) but also in a variety of media (HTF, IVF medium, D-PBS) and cell stage. The results were as follows: There is no clear advantage in these freezing media of rapid method, but 4 cell and 8 cell of slow method (2, 3, 4 step) have advantage in D-PBS. The development of embryos according to cell stage become greater in 8 cell stage. In the treatment steps of cryopreservation, the development of embryo to blastocyst was similar among rapid method, but the development of 4 cell and 8 cell embryos to blastocyst according to slow method was better than rapid method.

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Effect on Embryogenesis and Ultrastructural Behavior of lamda-DNA Following Microinjection into Fertilized Eggs of Xenopus laevis (Xenopus 수정란에 미세주입된 ${\lambda}-DNA$의 배발생에 미치는 영향 및 미세 구조에 관한 연구)

  • Song, Ji-Hwan;Sohn, Seong-Hyang;Choe, Rim-Soon;Chung, Hae-Moon
    • Applied Microscopy
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    • v.22 no.2
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    • pp.66-74
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    • 1992
  • In an attempt to produce transgenic amphibia, bacteriophage ${\lambda}-DNA$ was microinjected into fertilized eggs of Xenopus laevis, and the effect on early embryogenesis and the ultrastructural behavior of exogenous DNA were investigated. The effect of microinjected gene on embryonic development showed differences according to the concentration of injected DNA and the incubation temperature. Various concentrations of ${\lambda}-DNA$ were tested. Among those, microinjection of 1-2 ng DNA dissolved in 20 nl TE buffer was not shown to disturb normal embryonic development and was recorded the highest survivability to the late tadpole stage (Stage 43); however, injection of increased concentrations of DNA than above provoked irregular cleavages or abnormal appearances, which resulted in reduced survivability. When the injected embryos were incubated at low temperatures (e.g., $12^{\circ}C$), 54.5% of the embryos developed to Stage 43, whereas 42.4% survived when incubated at room temperature. The survivability showed also differences according to the injection site. 58.0% of the embryos developed to Stage 43 when microinjected into the vegetal pole, whereas 44.9% survived when microinjected into the animal pole. To understand the structural fate or behavior of injected DNA a combined light and electron microscopical study was applied. The nucleus-like structure was observed in the ${\lambda}$ DNA-injected embryos, which was quite a similar to the interphase nuclei of normal Xenopus laevis. The nucleus-like structure showed the typical double-layered nuclear membrane and nuclear complexes; however, it consisted of unusual structures such as furrows of nuclear envelope into the nucleoplasm.

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Average Droplet Size Distribution of a GDI Spray by Simultaneous Fluorescence/Scattering Image Technique (형과/산란광 동시 측정에 의한 GDI 분무의 평균 입경 분포에 관한 연구)

  • Gwak, Su-Min;Ryu, Gyeong-Hun;Choe, Dong-Seok;Kim, Deok-Jul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.6
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    • pp.868-875
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    • 2001
  • The objective of this study is to investigate the average droplet size distributions of a GDI spray by simultaneous fluorescence/scattering image technique. GDI engine is recently very popular because of high engine efficiency and low emissions. However, the injectors must have good spray characteristics because the fuel is directly injected into the cylinder. The fuel mixtures used in this study were 2% of fluorobenzene, 9% of DEMA(diethyl-methyl-amine) and 89% of hexane by volume. The system for obtaining 2-D fluorescence/scattering images of fuel spray was constituted of a laser sheet, a doubling prism, optical filters, and an ICCD camera. Using the ratio of the fluorescence to the scattering intensities, SMD distributions were obtained. SMD measured by the technique was compared with that obtained by PDA. It was found that average droplet size was bigger at spray center in the early stage of injection and at the outer periphery of the spray in the late stage of injection.

Comparison between heavy oil combustion test and numerical analysis of combustion phenomena subject to changes in injection characteristics (분무특성에 따른 중유연소 수치해석의 결과와 실험과의 비교)

  • Lee, S.S.;Kim, H.J;Kim, J.J.;Choi, K.S.
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.338-343
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    • 2003
  • Computations were performed to investigate the spray characteristics of the twin fluid nozzle in three stage heavy-oil combustion burner. The burner geometry and flow conditions were provided by a burner company. The goal of the study is to estimate mean droplet size, initial velocity and spread factor of the nozzle through comparison between experiments and numerical analyses. Air stage ratio is 2:4:4 by mass, and O2 in exhaust gas is about 4 % by volume. Here, the agreement between the experiment and numerical analyses is evaluated by NOx generation. Spray characteristics will be linearly interpolated between fuel consumption rate l20L/h and 240 L/h.

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Effect of Oxygen Injection on Microstructure and Mechanical Properties of Ni-based Superalloy Recycled by AOD Process (AOD공정으로 재활용된 니켈합금의 산소주입량에 따른 조직과 기계적 성질 변화)

  • Lee, Duk-Hee;Woo, Kee-Do;Kang, Whang-Jin;Yoon, Jin-Ho
    • Resources Recycling
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    • v.25 no.2
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    • pp.10-16
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    • 2016
  • In this study, the Ni base superalloy was recycled by Argon oxygen decarburization(AOD) process using an inconel 713C scrap. During AOD process, argon gas was continuously injected 1,000 sccm and oxygen gas was injected into 10, 20 and 30 minutes of 100, 250 and 500 sccm.. In early stage of oxygen injection, the oxygen dose increased with increasing Al, Cr, and Mo content and decreasing C content. And Al content was decreased by carburization with added elements in late stage Because of oxidation was occurred with Al, Cr etc. after the reaction of carbon has been finished. From the results, the ratio of ${\gamma}^{\prime}$ phase reduced due to decreasing of Al content for that reason Al is the main element to form the ${\gamma}^{\prime}$ phase. Also carbide reduced owing to decreasing of C content so the mechanical properties of the specimens excessively injected by excess $O_2$ gas were decreased.

Development of Flash Boiling Spray Prediction Model of Multi-hole GDI Injector Using Machine Learning (머신러닝을 이용한 다공형 GDI 인젝터의 플래시 보일링 분무 예측 모델 개발)

  • Chang, Mengzhao;Shin, Dalho;Pham, Quangkhai;Park, Suhan
    • Journal of ILASS-Korea
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    • v.27 no.2
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    • pp.57-65
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    • 2022
  • The purpose of this study is to use machine learning to build a model capable of predicting the flash boiling spray characteristics. In this study, the flash boiling spray was visualized using Shadowgraph visualization technology, and then the spray image was processed with MATLAB to obtain quantitative data of spray characteristics. The experimental conditions were used as input, and the spray characteristics were used as output to train the machine learning model. For the machine learning model, the XGB (extreme gradient boosting) algorithm was used. Finally, the performance of machine learning model was evaluated using R2 and RMSE (root mean square error). In order to have enough data to train the machine learning model, this study used 12 injectors with different design parameters, and set various fuel temperatures and ambient pressures, resulting in about 12,000 data. By comparing the performance of the model with different amounts of training data, it was found that the number of training data must reach at least 7,000 before the model can show optimal performance. The model showed different prediction performances for different spray characteristics. Compared with the upstream spray angle and the downstream spray angle, the model had the best prediction performance for the spray tip penetration. In addition, the prediction performance of the model showed a relatively poor trend in the initial stage of injection and the final stage of injection. The model performance is expired to be further enhanced by optimizing the hyper-parameters input into the model.

Production of cloned Mice by Nuclear Transplantation and Electrofusion Using 2- or 8-Cell Stage Mouse Embryo as Nuclear Donor (2- 및 8- 세포기 생쥐 수정란의 핵이식 및 전기융합법에 의한 복제산자의 생산)

  • 박준규;조성근;박희성;박충생
    • Journal of Embryo Transfer
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    • v.10 no.3
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    • pp.209-217
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    • 1995
  • The present study was carried out to develop a cloning technology of mouse embryos by nuclear transplantation with electrofusion and to produce cloned offsprings by transfer of reconstituted embryos. A single nucleus from two- and eight-cell embryos was transplanted into the enucleated two-cell embryos by rnicromanipulation. The fusion of nucleus with recipient cytoplasm and the subsequent development of reconstituted embryos in vitro as well as in vivo to term were examined to determine the optimal electrofusion parameters for nuclear transplantation in mouse embryos. The successful enucleation of donor embryos was 84.9 and 83.3% in two- and eight-cell stage, respectively, and the successful injection of nucleus from two- and eight-cell donor embryos into the perivitelline space of enucleated two-cell embryos were 85.1 and 84.7%, respectively. No significant differences were found in enucleation or injection rate between the cell stages of donor embryos. When the blastomeres of intact two-cell mouse embryos were electrofused in 0.3 M mannitol medium(100 $\mu$sec., 3 pulses), the fusion rate was similarly 93.2, 92.2 and 92.0% in 1.0, 1.5 and 2.0 kV /crn, respectively, but in vitro development to blastocyst of the fused two-cell embryos was significantly(P<0.05) lower in 2.0 kV/cm (63.4%) than in 1.0 kV/cm (91.7%) or 1.5 kV/cm (82.4%). The development in vitro to eight-cell stage of the reconstituted embryos with nucleus from two-cell stage(45.5%) was significantly(P<0.05) higher than that from eight-cell stage blastomeres (16.7%). The number of blastomeres of the intact embryos at blastocyst stage was 50i0.6 and 55$\pm$2.4 in in vitro and in vivo cultured mouse embryos, respectively, but significantly(P<0.05) decreased to 35$\pm$0.7 in nuclear transplanted blastocyst embryos. The conception rate of mice following embryo transfer was 32.1% in the reconstituted two-cell embryos using two-cell donor nuclei, which was comparable to the fresh two-cell embryos(40.6%). However, the rate of development in vivo to term following embryo transfer of the reconstituted two-cell embryos using two-cell donor nuclei (23.5%) was significantly(P<0.05) lower compared with the percentage of two-cell fresh embryos(31.5%).

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Ginsenoside Rg1 Attenuates Neuroinflammation Following Systemic Lipopolysaccharide Treatment in Mice

  • Shin, Jung-Won;Ma, Sun-Ho;Lee, Ju-Won;Kim, Dong-Kyu;Do, Kyuho;Sohn, Nak-Won
    • The Korea Journal of Herbology
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    • v.28 no.6
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    • pp.145-153
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    • 2013
  • Objectives : Neuroinflammation is characterized by microglial activation and the expression of major inflammatory mediators. The present study investigated the inhibitory effect of ginsenoside Rg1 ($GRg_1$), a principle active ingredient in Panax ginseng, on pro-inflammatory cytokines and microglial activation induced by systemic lipopolysaccharide (LPS) treatment in the mouse brain tissue. Methods : Varying doses of $GRg_1$ was orally administered (10, 20, and 30 mg/kg) 1 h before the LPS injection (3 mg/kg, intraperitoneally). The mRNA expression of pro-inflammatory cytokines in the brain tissue was measured using the quantitative real-time PCR method at 4 h after the LPS injection, Microglial activation was evaluated using western blotting and immunohistochemistry against ionized calcium binding adaptor molecule 1 (Iba1) in the brain tissue. Cyclooxigenase-2 (COX-2) expressions also observed using western blotting and immunohistochemistry at 4 h after the LPS injection, In addition, double-immunofluorescent labeling of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and COX-2 with microglia and neurons was processed in the brain tissue. Results : $GRg_1$ (30 mg/kg) significantly attenuated the upregulation of TNF-${\alpha}$, interleukin (IL)-$1{\beta}$ and IL-6 mRNA in the brain tissue at 4 h after LPS injection. Morphological activation and Iba1 protein expression of microglia induced by systemic LPS injection were reduced by the $GRg_1$ (30 mg/kg) treatment. Upregulation of COX-2 protein expression in the brain tissue was also attenuated by the $GRg_1$ (30 mg/kg) treatment. Conclusion : The results suggest that $GRg_1$ is effective in the early stage of neuroinflammation which causes neurodegenerative diseases.

Arthroscopic Treatment of Septic Knee Arthritis in Old Aged Group: Prognostic Factor (50세 이상에서 발생된 화농성 슬관절염의 관절경적 치료: 예후 인자)

  • Lee, Dong-Chul;Shon, Oog-Jin;Kong, Byung-Sic
    • Journal of the Korean Arthroscopy Society
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    • v.14 no.2
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    • pp.114-119
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    • 2010
  • Purpose: The purpose of this study was to assess the result of arthroscopic treatment in septic knee arthritis and evaluate the prognostic factor over 50 years old. Materials and Methods: Fifty-two patients were treated by arthroscope for septic knee arthritis from January, 2002 to August, 2005. The mean follow-up period was 27.5months. We assessed Lysholm score as functional result, CRP normalized period as laboratory result, and knee range of motion as clinical result. We evaluated patient's age, underlying disease, causative organism, previous knee status (Kellgren stage), clinical status of septic arthritis (G$\ddot{a}$chter stage) and history of intra-articular injection as prognostic factor. Results: Mean Lysholm score was improved from 40.7 to 67.1. And the mean CRP normalized period was 38.7days. At last follow-up, almost patient (92%) were recovered to prior knee full range of motion and 45 patient (74%) were completely cured by one stage operation. The microorganism isolated were MSSA (n=13), MSSE (n=3), MRSA/MRSE (n=4),no microorganism (n=27) and others (n=5). In Lysholm score, young age (42.8(preop.)$\rightarrow$83.5(postop.)), Kellgren stage 0 ($45.5{\rightarrow}84.2$), G$\ddot{a}$chter stage I ($39.3{\rightarrow}73.1$) and no microorganism (442.1{\rightarrow}72.6$) were more increased than old age (439.3{\rightarrow}61.7$), Kellgren IV ($28.3{\rightarrow}43.7$), G$\ddot{a}$chter stage IV ($40.2{\rightarrow}67.1$) and MRSA/MRSE ($40{\rightarrow}58.75$). In case of old age (42.3days), G$\ddot{a}$chter stage IV (55.5), Kellgren stage IV(43.7), DM patient (42.1) and intra-articular injection history (52.1), the CRP titer normalized period was longer than mean period. MRSA/MRSE(n=3,75%) were not normalized in CRP titer at last follow-up. Conclusion: Arthroscopic treatment of septic knee would be an effective and satisfactory procedure. Age, previous knee status (Kellgren stage), underlying disease (DM), intra-articular injection history, microorganism and Ga¨chter stage effect end result outcome.

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Polydeoxyribonucleotide, as a Novel Approach for the Management of Medication-Related Osteonecrosis of the Jaw: A Preliminary Observational Study

  • Jung, Junho;Lim, Hae Soo;Lee, Deok-Won
    • Journal of Korean Dental Science
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    • v.11 no.2
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    • pp.57-61
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    • 2018
  • Purpose: Polydeoxyribonucleotide (PDRN), consisting of a mixture of deoxyribonucleotide polymers, has been suggested to have anti-inflammatory effects and enhance angiogenesis as an adenosine $A_{2A}$ receptor agonist. The aim of this study was to report the effectiveness of PDRN as an adjuvant therapy after surgical debridement in MRONJ (medication-related osteonecrosis of the jaw) patients. Materials and Methods: Five patients (1 male, 4 females, age 65~79 years) who were diagnosed with MRONJ stage 2 or 3 underwent surgical debridement and PDRN mucosal injection. After surgical debridement, patients were subject to daily injection with 1 ml of PDRN around the surgical wound for 14 days. Result: The patients' symptoms gradually disappeared. The surgical wound uneventfully healed, and no recurrence was observed during the follow-up period. Conclusion: Although further studies are required, the present study first describes the possibility of PDRN as a useful option for MRONJ treatment.