• Title/Summary/Keyword: strain recovery

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Study on Centrocestus armatus in Korea II. Recovery rate, growth and deve]opment of worms in albino rats (Centrocestus armatus에 관한 연구 II. 흰쥐에서의 성장 발육 및 충체회수율)

  • 홍성종;우호춘
    • Parasites, Hosts and Diseases
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    • v.27 no.1
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    • pp.47-56
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    • 1989
  • Some biological characteristics of Centrecestus armatui were studied using albino rats as its experimental host. The metacercariae were collected from Zacco Platypus by artificial digestion method. Laboratory rats(Wistar) were fed each 100 or 200 metacercariae and sacrificed on 1, 2, 3, 4, 5, 6, 8, 14 and 28 days after infection to recover worms of various ages. The average recovery rate was 10.7% from 82 rats. The rate decreased rather slowly for the first 8 days but showed a steep decrease thereafter. Of the worms, 35.5% were recovered from the duodenum and 62.5% from the jejunum. At metacercarial stage, body length was $293{\mu\textrm{m}}$ and body width $144{\mu\textrm{m}}$. At adult stage, the length and width reached $382{\mu\textrm{m}}$ and $214{\mu\textrm{m}}$ respectively at 14 days after infection. The testes and Mehlis' gland were recognized at metacercarial stage, whereas the ovarian anlage appeared on the 1st day of infection, seminal vesicle and vitellaria on the 2nd day, and seminal receptacle and uterine eggs on the 3rd day. Until 8 days after infection the genital organs developed continuously and the number of uterine eggs increased. The above results show that albino rats are one of useful experimental hosts for C. armatus and the worms can develop to adults in 3 days after infection.

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A Mutant Arthrospira platensis M20CJK3 Showing Enhanced Growth Rate and Floatation Activity (생장 및 부상성이 향상된 남세균 돌연변이 균주 Arthrospira platensis M20CJK3)

  • Yoo, Chan;Kim, Choong-Jae;Choi, Gang-Guk;Ahn, Chi-Yong;Choi, Jong-Soon;Oh, Hee-Mock
    • Korean Journal of Microbiology
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    • v.45 no.3
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    • pp.268-274
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    • 2009
  • A photosynthetic cyanobacterium Arthrospira platensis, well known for health food supplement, was studied as a target species for atmospheric $CO_2$ removal as well as biomass production. Although the biomass of A. platensis was massively produced in many countries, the recovery cost of its biomass is still high. The purpose of this study was to develop the A. platensis mutant strains which have enhanced growth rate and floatation activity to reduce the recovery cost. A. platensis KCTC AG20590 was treated with 0.24% ethyl methanesulfonate (EMS) for 20 min at room temperature. The mutant strain A. platensis M20CJK3 was finally selected by its morphological and physiological features. The morphology of the mutant A. platensis M20CJK3 was changed from loose-coiled form to tight-coiled form showing short pitch. The growth and $CO_2$ uptake rate of A. platensis M20CJK3 were improved about 15% and 17% compared with A. platensis KCTC AG20590, respectively. The floatation activity of A. platensis M20CJK3 was enhanced in 2-fold compared with that of A. platensis KCTC AG20590. Soluble proteins extracted from two strains were analyzed by two dimensional electrophoresis (2-DE) and MALDI-TOF MS/MS. Among 15 protein spots induced in 2-DE analysis, two spots were the proteins related to photosynthesis and electron transfer system of the other cyanobacteria. As a consequence, it seems that the tight-coiled mutant A. platensis M20CJK3 has an advantage of high growth rate and floatation activity which are beneficial for the mass cultivation and recovery.

Evaluation of Physical Properties and Long-term Stability of Expansion Materials for Emergency Repair by Temperature (긴급복구용 팽창재료의 온도에 따른 물리적 특성 및 장기 안전성 평가)

  • Park, Jeongjun;Kim, Kisung;Kang, Hyounhoi;Kim, Ju-Ho;Hong, Gigwon
    • Journal of the Society of Disaster Information
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    • v.14 no.1
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    • pp.79-88
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    • 2018
  • In this study, the changes of the expansion and strength according to the temperature of the emergency repairing expansion material were examined by cup foaming test and uniaxial compressive strength test, and the accelerated compression creep test was carried out to confirm the long term stability. Ramp & Hold test and accelerated compressive creep test were performed to evaluate the creep performance. The short - term creep test was used to determine the initial creep strain of the expanding material. The isothermal method using time - To evaluate the long - term compressive creep performance.

Transcription Mechanism of Minute Surface Pattern in Injection Molding

  • YASUHARA Toshiyuki;KATO Kazunori;IMAMURA Hiroshi;OHTAKE Naoto
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.04a
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    • pp.1-6
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    • 2003
  • In injection molding of an optical disk, a toric lens, etc., their performance depends on the transcription preciseness of fine surface structure of a mold. However, transcription behavior has not been made clear yet, because transcription is made in very short time and the structure is very small. In this paper, transcription properties have been examined, by using V-grooves of various sizes. machined on mold surfaces, and the following results are obtained. (1) Transcription properties have been made clear experimentally and it was found that the mold temperature $T_D$ makes great influence on the transcription property and that compression applying time $t_c$ should be taken more than 2.0s for fine transcription. (2) A mechanical model of transcription process, in consideration with strain recovery due to viscoelastic property of polymer. is proposed. (3) Simulation results agree with experimental ones fairly well. It means that the transcription model is useful for estimation of transcription property in advance of an actual. injection molding.

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Studies on the Production of Thermostable Amylase. Part 1. Optimal Culture Conditions and Purification of Enzyme. (내열성 Amylase의 생산에 관한 연구 (제1보) 최적배양조건과 효소의 정제)

  • 오두환;이강표;변유량;유주현
    • Microbiology and Biotechnology Letters
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    • v.9 no.2
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    • pp.91-97
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    • 1981
  • A thermophilic soil isolate Bacillus sp. Y-127 was selected for the production of thermostable amylase. The strain was used for the enzyme production and the thermostable amylase was characterized. The optimum cultural conditions for the enzyme production were 6$0^{\circ}C$ at pH 7.0 for 32 hours using a mineral medium containing 2% soluble starch and 0.2% yeast extract. The extra-cellular enzyme was purified about 123-folds with about 6% recovery. The purified enzyme was stable at pH between 4.0 and 7.0, and temperature up to 6$0^{\circ}C$.

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Diagnosis and Treatment of Acute Ankle Sprain (족관절 급성 염좌의 진단과 치료)

  • Byun, Chu-Hwan;Chung, Jin-Wha
    • Journal of Korean Foot and Ankle Society
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    • v.19 no.3
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    • pp.81-85
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    • 2015
  • Acute sprain of the ankle requires comprehensive history taking and physical examination in diagnosing the type of severity and deciding on the plan of treatment. Literature supports functional treatment as the treatment of choice for grade I and II injuries. During the acute phase, the goal of treatment focuses on controlling pain and swelling. PRICE (protection, rest, ice, compression, and elevation) is a well-established protocol at this phase. There is some evidence that application of ice and use of nonsteroidal anti-inflammatory drugs improves healing and speeds recovery. Then the functional treatment (motion restoration and strengthening exercises) is administered to progress the rehabilitation appropriately in order to facilitate healing and restore the mechanical strength and proprioception. Early mobilization has been shown to result in more rapid return to work and daily activities than immobilization. Grade III injuries still generate controversy in terms of the best management available, and more studies on early mobilization, cast immobilization, or surgery are needed. Even the Cochrane reviews published to date are not conclusive.

Adaptive Responses of Escherichia coli for Oxidative and Protein Damage Using Bioluminescence Reporters

  • Min, Ji-Ho;Gu, Man-Bock
    • Journal of Microbiology and Biotechnology
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    • v.14 no.3
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    • pp.466-469
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    • 2004
  • The recombinant bioluminescent Escherichia coli strains, DPD2511 and TV 1061 containing the katG and grpE promoters, respectively, from Vibrio fischeri fused to luxCDABE, were used to detect the adaptive and repair responses to oxidative damage caused by hydrogen peroxide $(H_2O_2)$, and protein damage due to phenol. The response ratio, represented as the bioluminescence induced in subsequent inductions of DPD2511 and TV1061 with the mother cells previously induced by each chemical, i.e., $H_2O_2$ and phenol during the previous induction stage, decreased suddenly compared with the ratio of the control culture of each strain, meaning there is a possible adaptive response to stress caused by chemicals. Protein damage due to phenol was completely repaired by the second culturing after the initial induction, as was oxidative damage caused by $H_2O_2$ which was also rapidly repaired, as detected by the recovery of bioluminescence level. This result suggests that E. coli promptly adapt and repair oxidative and protein damage by $H_2O_2$ and phenol completely.

Dilatation characteristics of the coals with outburst proneness under cyclic loading conditions and the relevant applications

  • Li, Yangyang;Zhang, Shichuan;Zhang, Baoliang
    • Geomechanics and Engineering
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    • v.14 no.5
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    • pp.459-466
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    • 2018
  • By conducting uniaxial loading cycle tests on the coal rock with outburst proneness, the dilatation characteristics at different loading rates were investigated. Under uniaxial loading and unloading, the lateral deformation of coal rock increased obviously before failure, leading to coal dilatation. Moreover, the post-unloading recovery of the lateral deformation was rather small, suggesting the onset of an accelerated failure. As the loading rate increased further, the ratio of the stress at the dilatation critical point to peak-intensity increased gradually, and the pre-peak volumetric deformation decreased with more severe post-peak damage. Based on the laboratory test results, the lateral deformation of the coals at different depths in the #1302 isolated coal pillars, Yangcheng Coal Mine, was monitored using wall rock displacement meter. The field monitoring result indicates that the coal lateral displacement went through various distinct stages: the lateral displacement of the coals at the depth of 2-6 m went through an "initial increase-stabilize-step up-plateau" series. When the coal wall of the working face was 24-18 m away from the measuring point, the coals in this region entered the accelerated failure stage; as the working face continued advancing, the lateral displacement of the coals at the depth over 6 m increased steadily, i.e., the coals in this region were in the stable failure stage.

Identification of a Bacterium which Produced D-Glucose Isomerase and Partial Purification on the Enzyme (포도당 이성화효소 생산균의 동정 및 그 효소의 부분정제)

  • Rhee, In-Koo;Seu, Jung-Hwn
    • Microbiology and Biotechnology Letters
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    • v.8 no.2
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    • pp.125-133
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    • 1980
  • A microorganism which produced D-glucose isomerase was identified to be similar to Streptomyces antibioticus on the morphological, cultural and physiological characteristics except the spore chain and the utilization of sucrose. D-xylose grown cells of Streptomyces sp. strain K-17 were disrupted by grinding with sea sand. D-glucose isomerase was partially purified with the fractionation by ammonium sulfate, Mn-treatment, DEAE-cellulose column chromatography, DEAE-sephadex (A-50) column chromatography and gel filtration of sephadex G-200. The enzyme was purified about 380 fold with 25 % recovery.

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Measurement of Pressure-Rise at No-Load in 800kV Model Interrupter (800kV 차단부의 무부하 압력상승 측정)

  • Chang, K.C.;Song, K.D.;Chung, J.K.;Song, W.P.;Kim, J.B.;Park, K.Y.;Shin, Y.J.
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.475-478
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    • 1995
  • The variations of cold gas properties such as density, pressure, temperature and velocity which are dependent each other are closely related with the dielectric recovery of an interrupter. So, the pressure-rises at no-load in the puffer cylinder and in front of fixed arcing contact of 800kV model interrupter were measured experimentally using pressure transducers of strain gage type and semiconducting type, respectively. The maximum value of pressure-rise in the puffer cylinder increased almost linearly from 7.6 bar at the minimum operated pressure to 9.7 bar at the maximum operated pressure, while the pressure-rise in front of fixed arcing contact was independent with the operated pressure. The measured values will be utilized in verifying the self-developed cold flow analysis program and as an input of commercialized CFD program package.

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