• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.258-258
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• 1994

본 연구에서는 토양균이 생성하는 2차 대사산물로부터 세포증식 촉진인자 (Maturation Promoting Factor. MPF)인 cdc2/cdk2-cyclin의 복합체를 특이적으로 억제하는 물질을 분리하고 그 물질의 생리활성을 조사하였다. 토양으로부터 순수분리된 300여개의 토양균에서 생성된 배양액을 취하여 MPF의 특이적인 기질인 합성 peptide (CSH103 :HATPPKKKRK)를 사용하여 인산화 활성을 측정하였다. 그중 MPF 활성 억제능이 90％ 이상인 19개의 균주를 1차적으로 선정한 후 각각에 대하여 열/pH에 대한 안정성, 각종 용매에 대한 추출성 등 이화학적 성질을 규명하였으며 이중 균주 LPL 931로부터 MPF 활성 억제제를 분리하고자 하였다. 예비실험의 결과로부터 토양균 LPL 931을 대량배양하여 열처리하고, 비이온성 수지인Amberlite XAD-2에 결합시키고 70% acetone으로 용출시켰다. 이 추출물로부터 ethylacetate와 n-butanol을 사용하여 MPF 억제 활성물질을 추출하였다. 이 추출액을 실리카겔 관 크로마토그래피, 분취 TLC, 분취 HPL를 하여 MPF 활성 억제 분획을 분리하였다.

• The Korean Journal of Zoology
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• v.35 no.3
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• pp.277-286
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• 1992

개구리의 난자로 부터 maturation promoting factor(MPF)를 추출, 부분 분리하여 이들의 활성을 조사하고 이 물질의 생성과 protein kinase C(반KC)와의 관계를 조사하SB다. 성숙된 난자를 분쇄한 후 초원심분리과정을 거쳐 MPF의 crude extract(CE)를 얻은 다음 ultrafiltration (UF)과 고속액체크로마토그라피를 거쳐서 3종류의 분획 (peak 1, 11, and 111)을 얻었다. 이들 분획을 in nitro assay와 autoradiDgraphy를 사용하여 확인한 결과 분획 11에서 MPF 활성이 있는 것을 알았다. 분리 단계에 따라 MPF의 정제도를 Hl histone kinase assay로 조사한 결깍 UF를 거친 것은 CE보다 약 3배로, 분획 11에서는 약 117배로 증가한 것을 확인하였다. 또한 MPF분획의 인산화를 autoradiography로 조사한 결과 45 KD 단백질을 포함한 수종의 난자 단백질이 강하게 인산화되었음을 알 수 있었다. PKC의 활성화가 난자내 MPF의 생성을 유도하는가를 보기 위하여 PKC의 활성제인 12-0-tetradecanoyl phorbol 13 acetate(TPA)를 처리한 난자의 세포질 추출물을 미세주입 법으로 조사한 결과 TPA 처리 후 6시간부터 난자내 MPF의 활성이 나타나는 것을 알 수 있었다. 이러한 결과들은 PKC의 활성화가 MPF의 생성을 유도하고, MPF의 활성화와 함께 일부 단백질들의 인산화를 통하여 궁극적으로 난자 성숙을 촉진했음을 시사한다.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.7
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• pp.971-979
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• 1999

The experiment was conducted on five different kinds of fabrics dyed with loess. The sewability of fabrics dyed with loess by measuring the maximum needle piercing forces(MPF) through fabrics has been studied, MPF measurement using tensile tester was done 60 times for each fabrics at fixed low speed of 300mm/min. The nature of the loess on the dyed fabrics was physically jammed betweenthe fibers or adhered to the surface of fibers in the form of the fine particles so that the MPF through fabrics increases extremely in proportion to the increase of loess uptake and the plying number of fabrics dyed with loess. This results indicate that the MPF through fabrics is affected by mean value of the coefficient of friction on the surface of fabric(MIU) and cloth cover factor(Kc) in this experiment. Fabric was finished with softner to decrease the MPF during sewing operation, The MPF through softner finished fabric was decreased remarkably.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.1
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• pp.19-25
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• 1989

Effect of removal time of mulched polyethylene film on the chlorine content of toP soil and on the chlorine absorption by burley tobacco Plants was investigated under the field condition in 1986 and 1987. Treatment consisted of 4 removal times (from 30 to 75 days after transplanting with IS days interval) and control (no removal). The chlorine content of top Boll at 15 days after removal of mulched polyethylene film(MPF) lowered temporarily, and the decrement of chlorine content of top soil was closely related to the sum of rainfalls after removal of MPF. The chlorine was accumulated much in upper leaves when the MPF being removed early, while the chlorine was accumulated much in lower loaves when the MPF being removed late, relatively. However, the removal of MPF had no effect on the chlorine content of whole leaf. The yield decreased with removal of MPF during growing period.

• Food Science of Animal Resources
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• v.21 no.3
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• pp.227-234
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• 2001

This study was conducted to determine the effects of microperforated film on the quality and shelf-life improvements of pork bellies during cold storage. Samples were stored for 14 days at 0$\pm$1$^{\circ}C$ and 55$\pm$10% r.h.. The packaging treatments were the unpackaged sample as control, the wrapped sampled with microperforated polypropylene film(MPF) and unperforated PP film(PPF), respectively. After 10 days, the counts of all kinds of microorganisms investigated tended to be the lowest in the control samples, and followed by MPF and PPF. The 'a' value for PPF was significantly lower than the values for control and MPF at 14 day. The 'L' values for MPF measured after 10 days were significantly lower than those of PPF and higher than those for control. After 4 days of storage, the 'b' values for PPF showed significantly lower than those of MPF. As storage time elapsed, percent weight loss was the highest in the control samples followed by those from MPF and PPF. Sensory analyses showed that MPF samples tended to be evaluated higher in all parameters than the control and PPF samples after 7 days. It is concluded that microperforated film wrapping can be used efficiently for maintaining the quality of fresh pork bellies during cold storage and retail display.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.461-468
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• 2004

Modal participation factor(MPF) is essential to analyze structural response under earthquake load. MPF of real structure differs from that of analytic mathematical model due to the error induced from analytical assumption and construction. In this study, a identification method is proposed to calculate the MPF of real structure based on H∞ optimal model reduction. The MPF is obtained from the relationship between observability, controllability matrix of realized from S.I. and typical 2-degree state space model. The proposed method is verified thorough examples.

• The Korean Journal of Zoology
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• v.35 no.1
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• pp.37-44
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• 1992

북방산개구리, 참개구리 및 옴개구리를 사용하여 성숙된 난자의 세포질에서 활성을 띠는 성숙촉진요인( maturation promoting factor, MPF)을 미세주입 법으로 확인하고 이들의 성질을 조사하였다. 핵붕괴(germinal vesicle breakdown, GVBD)된 난자의 세포질을 미성숙 난자(GV난자)에 주입하고(75-100 nl) 이들을 15-24시간 배양했을 때 대부분의 GV 난자들이 핵붕괴를 일으켰으나(약 80%) 미성숙 난자(GV 난자)의 세포질을 주입했을 때에는 약 200nl의 난자들만이 핵붕괴를 일으켰다. 핵붕괴된 난자들의 crude extract를 주입했을 때에도 역시 성숙유도 효과가 있었으며 이종간에도 효과가 있었다. 난자의 성숙을 잘 일으키지 않는 옴개구리의 난자를 사용하여 MPF를 가진 세포질을 계대주입(serial transfer)하였을 때에도 MPF가 계속 활성을 띠는 것을 확인할 수 있었다. 아울러 개구리 난자의 MPF생성과 증폭과정에 CAMP의 증가나 단백질 합성의 저해가 미치는 영향을 조사한 결과. MPF의 작용이 유의하게 이들에 의해 억제되는 것을 알 수 있었다.

• Journal of Embryo Transfer
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• v.23 no.1
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• pp.31-36
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• 2008

We attempted to control the maturation promoting factors (MPF) activity and nuclear remodeling of somatic cell nuclear transfer (NT) bovine embryos. Bovine ear skin fibroblasts were fused to enucleated oocytes treated with either 5 mM caffeine for 2.5 h or 0.5 mM vanadate for 0.5 h and activated. The nuclear remodeling type of the reconstituted embryos was evaluated 1.5 h after activation. MPF activity was assessed in enucleated and chemical treated oocytes before the injection of a donor cell. Effect of chemicals on the embryonic development was evaluated with parthenogenetic embryos. MPF activity increased significantly by caffeine treatment, but decreased by vanadate treatment (p<0.05). Caffeine or vanadate had no deleterious effect on the parthenogenetic embryo development. In caffeine treated group, premature chromosome condensation (PCC) was occurred in 72.2% of NT embryos (p<0.05). In contrast, vanadate induced the formation of a pronucleus-like structure (PN) in a high frequency (68.9%, p<0.05) without PCC (NPCC). Blastocyst development of NT embryos increased by treating with caffeine (30.3%), whereas decreased by treating with vanadate (11.4%) compared to control (22.1%, p<0.05). The results indicate that caffeine or vanadate can control of MPF activity and remodeling type of NT embryos, resulting in the increased or decreased in vitro development.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.255-255
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• 2004

본 연구는 한우 체세포 복제수정란의 발달에 있어서 난자가 체외성숙 된 시간이 미치는 영향을 확인하고, 또한 체외성숙 시간별 성숙난자의 MPF 활성도 변화를 조사함으로서 소 복제수정란 생산을 위한 적정 체외성숙 조건을 살펴보는데 목적이 있었다. 도축된 한우로부터 채취된 난소로부터 미성숙 난자를 채취하여, 1 ㎍/㎖ FSH와 1 ㎍/㎖ E2가 첨가된 TCM-199 배양액에서 18, 20, 22시간 체외성숙 후에 각각 성숙난자를 회수하여 22시간째 제핵을 실시하였다. (중략)

• The Journal of Korean Physical Therapy
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• v.13 no.3
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• pp.777-789
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• 2001

The purpose of this study was to investigate the possibility of using surface electromyographic signals as a measure of muscle fatigue during the wheelchair propulsion. Subjects performed wheelchair exercise tests on a motor-driven treadmill with a constant-velocity of 1.25 m/sec. During each test, the raw EMC signals were acquired from the surface electrodes attached on the belly of five muscle groups: biceps brachii, pectoralis major. deltoid, triceps brachii, and trapezius. The median power frequency(MPF), and the root mean square(RMS) amplitude were calculated for each cyclic contraction in order to quantify muscle fatigue. During the wheelchair propulsion, the MPF decreased and the RMS increased in the trapezius and deltoid. However, the decreasing MPF and the increasing RMS also fluctuated severly during dynamic muscle contractions. Therefore, the MPF and RMS values should be estimated with well-designed methods and used with caution to quantify muscle fatigue during wheelchair propulsion.