• 한국식품영양과학회지
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• 제21권6호
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• pp.681-685
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• 1992

돼지고기에서 분리한 bacteriocin 생성능이 우수한 젖산균을 동정하기 위하여 이미 알려진 몇가지 젖산균을 참고균으로 하여 10% denaturing polyacrylamide gel에 전기영동으로 전개한 5S rRNA 와 tRNA 등 150개 이하의 핵산으로 구성된 저분자량 RNA(Low Molecular Weight RNA : LMW RNA) profiles에 나타난 15~25개의 밴드 양상이 균에 따라 차이점을 보여 동정에 효과적으로 이용할 수 있었다. 새로 분리한 젖산균은 참고균과는 다른 균종이었다. APT, TSB, MRS의 3종류 다른 배지에서 배양하여도 LMW RNA profiles에는 차이가 없었으며, 겔상의 밴드 전개거리를 3개의 표준 분자량 물질을 이용하여 만든 표준곡선을 사용하여 상대핵산단위(relative nucleotide units : RNU)로 나타낸 밴드의 양상을 도표화 하는 것이 profiles를 서로 비교 하는데 편리하였다.

• Journal of Microbiology
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• 제40권1호
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• pp.70-76
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• 2002

Proviral DNAs from HIV-1-infected CD4+ T cells (Molt/LAV cells) were amplified and detected in infected individual cells using polymerase chain reaction and in rifu hybridization. In this in situ PCR, three parameters were considered to achieve effective amplification and retention of amplificants inside the cells by making high molecular weight PCR products intracellularly, forming agarose matrix against the cells, and maintaining the appropriate PCR temperature profile. Over the cycles of ampliHcationl tailed primers with complementary overhanging sequences at their 5' sides manufactured high molecular weight products by using short primary products as a repeating unit. Agarose matrix could prevent the diffusion of the amplificants from the cells. Use of Thermanox coverslip inside the PCR tube offered target cells a similar temperature profile to that of conventional PCR in solution.

• Archives of Pharmacal Research
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• 제7권1호
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• pp.23-31
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• 1984

An improved mass spectrometric method for multicomponent analysis of metabolites in urine, well-suited for clinical biochemistry, is described. The method involves solvent elution of the metabolites from an adsorbent and the concentration of the eluate on a microadsorption column. This is administered by a direct inlet probe into the ionizing source of field ionization mass spectrometry (FIMS), which yield a molecular weight profile of the metabolites. The procedure provides rapidly (within one hour) reproducible profiles from a small volume of urine. The optimization of the sampling technique and the reproducibility are discussed.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1979년도 추계학술대회 심포지움
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• pp.243.3-244
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• 1979

Low molecular weight endo-glucanase fraction of cellulase from Trichoderma reesei was purified using Sephadex G-100 and concanavalin A-Sepha-rose 4B affinity chromatography. Its biochemical characteristics including pH profile, temperature profile and kinetic behavior were studied. The optimum conditions for enzymatic reaction were pH 6.0 and $5^{\circ}C.$ The activation energy for CMC (carboxymethylcellulose) was 10,800 cal/mole. Its adsorption to amorhous and crystalline cellulose was observed. Adsorption to amorphous cellulose was more rapid and greater than that of crystalline cellulose. Reconstitution study was performed. Significance of low molecular weight endo-glucanase on cellulose hydrolysis will be further discussed.

• Macromolecular Research
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• 제11권5호
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• pp.352-356
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• 2003

The objectives of this study were to investigate the influence of gamma irradiation for sterilization on poly(D,L-lactide-co-glycolide) (PLGA) with different molecular weight and the effect of gamma irradiation on the release behavior of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, carmustine) from PLGA wafer with various irradiation doses. The effect of gamma irradiation on PLGA was evaluated by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and electron paramagnetic resonance (EPR). The weight average molecular weight (M$_{w}$) and glass transition temperature (T$_{g}$) of PLGA decreased after gamma irradiation. The extent of M$_{w}$ reduction was dependent on irradiation dose and PLGA molecular weight. Using EPR spectroscopy, we successfully detected gamma irradiation induced free radicals in PLGA. The gamma irradiation increased the release rate of BCNU from PLGA wafer at applied irradiation doses except 2.5 Mrad of irradiation dose in this study.study.

• Korea-Australia Rheology Journal
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• 제21권3호
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• pp.149-153
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• 2009

Profile development of the melt spinning process of poly(ethylene terephthalate) (PET) was simulated by a numerical method under the consideration of two constitutive equations of Newtonian and upper convected Maxwell (UCM) models. The viscoelastic characteristics of the polymer were considered via UCM constitutive equation that considered relaxation time as a function of temperature and molecular weight. The UCM model predicted the diameter profile better than the Newtonian, while velocity development was slower than the Newtonian model. Viscoelasticity played an important role in accurately predicting diameter profile. However, even though neck-like deformation was observed in the UCM model, the exact position of the deformation under high speed spinning was not obtained.

• 대한미생물학회지
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• 제22권3호
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• pp.267-273
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• 1987

In the analysis of plasmid profile obtained by agarose gel electrophoresis, the strain harvoring multiple reference plasmids of known molecular weight were needed to estimate the size of unknown molecular weight plasmids. Six strains of E. coli isolated from clinical specimens carried multiple plasmids and these strains could be available as a reference plasmids harvoring strain. These E. coli strains showed 4 to 9 plasmids of various size ranging 2.5 to 94.3 megadalton (Mdal). The correlation coefficients of linear regression between the relative mobility and molecular weight were 0.99966 to 1.00000. Among them, E. coli KE327 from throat which contained 7 plasm ids as follows: 79 Mdal, 46 Mdal, 33 Mdal(pKY3027 C), 4.9Mdal, 3.8Mdal(pKY3027 E), 3.5Mdal, and 2.7 Mdal. Relative amount of the pKY3027 C was the smallest(7.09%) and that of the pKY3027 E was the largest (24.24%) among the plasmid fractions of E. coli KE327.

• Journal of Pharmaceutical Investigation
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• 제38권1호
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• pp.63-72
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• 2008

Meloxicam-loaded microspheres were prepared with poly(D,L-lactic acid)(PLA) by a solvent-emulsion evaporation method. The morphology, particle size, drug loading capacity, drug entrapment efficiency (EE) and release patterns of drug were investigated in vitro. Various batches of micro spheres with different size and drug content were obtained by changing the ratio of meloxicam to $PLA^{\circ}{\AE}s$ with different molecular weight, PLA concentration in the dispersed phase and stirring rate. Meloxicam crystals on microsphere surface, which were released rapidly and could act as a loading dose, were observed with increasing drug content. The release rate was increased with increase in drug contents and decrease in the molecular weight of PLA. Microspheres prepared with smaller molecular weight produced faster drug release rate. The release rate of meloxicam for long-acting injectable delivery system in vitro, which would aid in predicting in vivo release profile, could be controlled by properly optimizing various factors affecting characteristics of microspheres. Blood concentration-time profile of meloxicam after intramuscular injection of meloxicam-loaded microspheres in rabbits showed possibility of long term application of this system in clinical settings.

• Macromolecular Research
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• 제14권4호
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• pp.461-465
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• 2006

Two types of injectable system using thermosensitive chitosan (chitosan-g-NIPAAm), hydrogel and microparticles (MPs)-embedded hydrogel were developed as drug carriers for controlled release and their pharmaceutical potentials were investigated. 5-Fluorouracil (5-FU)-loaded, biodegradable PLGA MPs were prepared by a double emulsion method and then simply mixed with an aqueous solution of thermosensitive chitosan at room temperature. All 5-FU release rates from the hydrogel matrix were faster than bovine serum albumin (BSA), possibly due to the difference in the molecular weight of the drugs. The 5-FU release profile from MPs-embedded hydrogel was shown to reduce the burst effect and exhibit nearly zero-order release behavior from the beginning of each initial stage. Thus, these MPs-embedded hydrogels, as well as thermosensitive chitosan hydrogel, have promising potential as an injectable drug carrier for pharmaceutical applications.

• 대한수의학회지
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• 제29권2호
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• pp.59-67
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• 1989

This paper deals with the genetic properties of R plasmids in Salmonella originated from pigs and cattle. The plasmid DNA was examined for incompatibility, stability and fertility inhibition(Fi), and gel electrophoresis was performed for isolation of plasmid DNA. The results obtained were summerized as follows: 1. Among the 66 conjugative R plasmids from 44 pigs and 22 cattle, 61 R plasmids (92.4%) were $Fi^-$, whereas the remainder were $Fi^+$. 2. The Inc groups of 66 R plasmids were determined with 7 standard plasmids. Twenty-six R plasmids were classified into Inc group $I{\alpha}$, H1, H2 or F1, 40 R plasmids being not classified with standard plasmids used, and the Inc group $I{\alpha}$ (57.7%) was most frequent. 3. Inc groups $I{\alpha}$, H1, and F1 were identified in strains from swine, Inc groups H2 and F1 from cattle. 4. The plasmid DNA profiles in 16 Salmonella isolated from pigs and cattle were confirmed as being 1 to 10 fragments by the gel eletrophoresis. Their molecular weight ranged 1.0 to 90 megadalton. 5. The molecular weight of conjugative plasmids ranged 1.0 to 80 megadalton in 4 Salmonella (P-4, P-5, P-7 and P-8) isolated from pigs.