• Title/Summary/Keyword: mean molecular weight

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Intestinal Permeabilities of Polyethylene Glycols (330-1122D) in the In Situ Perfused Rat (장내 관류된 동물에서 Polyethylene Glycols에 의한 장내 투과율 (Intestinal Permeability)측정에 관한 연구)

  • 김미혜
    • Journal of Nutrition and Health
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    • v.29 no.2
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    • pp.153-158
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    • 1996
  • Polyethylene glycols(PEGs)are hydrophilic molecules that have been used to characterize intestinal permeability via the paracellular pathway. Using a mixture of PEGs(400, 600 and 1000), containing oligomers in the molecular weight range 330 to 1122 D, the molecular weight permeability dependence in the jejunum of the rat small intestine was examined, employing an in situ recirculation perfusion technique. Individual oligomers were determined by HPLC with refractive detection. In the range studied, a distinct molecular weight cut-off was not apparent. Corrected for the length of jejunum used in the study, over the molecular weight range 330 to 1122D, the apparent permeability(Papp) of PEG ranged from 4.92$\pm$0.02$\times$10-5cm/sec(mean$\pm$SEM, n=5) to 0.28$\times$10-5cm/sec. Also, it was observed that the apparent permeability was inversely proportional to approximately MW2. The results in this study suggest that molecular weight is an important factor in determining the intestinal permeability.

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Effects of carboxymethyl chitosan fabric and low molecular weight heparin on reducing adhesion formation in the rat (Rat에서 carboxymethyl chitosan fabric과 low molecular weight heparin의 유착방지 효과)

  • Kwon, Young-sam;Jang, Kwang-ho
    • Korean Journal of Veterinary Research
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    • v.43 no.4
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    • pp.703-708
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    • 2003
  • This study was carried out to compare the efficacy of carboxymethyl chitosan fabric (CMCF) with that of the combination of low molecular weight heparin (LMWH) and CMCF for the prevention of postoperative adhesions in the rat. Adhesions were induced by suturing both the ileal serosa and peritoneum scraped until petechial bleeding occurred. CMCF were sutured between two surfaces, and LMWH were instilled intraperitoneally immediately before closure of the peritoneomuscular layer. The adhesions were blindly assessed 2 weeks later by using a tensiometer. The mean tensile strength(Newton) of formed adhesions was $2.59{\pm}0.85$ in control group, $2.10{\pm}0.75$ in the CMCF group and $1.53{\pm}0.44$ in the CMCF+LMWH group. The most favorable prevention against adhesion was achieved in the CMCF+LMWH group. Therefore, we could conclude that CMCF+LMWH were effective in prevention against postoperative adhesion in the rat.

Studies on Synonymous Codon and Amino Acid Usage Biases in the Broad-Host Range Bacteriophage KVP40

  • Sau Keya;Gupta Sanjib Kumar;Sau Subrata;Mandal Subhas Chandra;Ghosh Tapash Chandra
    • Journal of Microbiology
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    • v.45 no.1
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    • pp.58-63
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    • 2007
  • In this study, the relative synonymous codon and amino acid usage biases of the broad-host range phage, KVP40, were investigated in an attempt to understand the structure and function of its proteins/protein-coding genes, as well as the role of its tRNAs. Synonymous codons in KVP40 were determined to be AT-rich at the third codon positions, and their variations are dictated principally by both mutational bias and translational selection. Further analysis revealed that the RSCU of KVP40 is distinct from that of its Vibrio hosts, V. cholerae and V. parahaemolyticus. Interestingly, the expression of the putative highly expressed genes of KVP40 appear to be preferentially influenced by the abundant host tRNA species, whereas the tRNAs expressed by KVP40 may be required for the efficient synthesis of all its proteins in a diverse array of hosts. The data generated in this study also revealed that KVP40 proteins are rich in low molecular weight amino acid residues, and that these variations are influenced primarily by hydropathy, mean molecular weight, aromaticity, and cysteine content.

Measurement of ileal permeability with different-sized polyethylene glycols (PEG 400, 600 and 1000)

  • Kim, Mee-Hye
    • Archives of Pharmacal Research
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    • v.19 no.2
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    • pp.100-105
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    • 1996
  • Polyethylene glycols (PEGs; 400, 600, and 1000) were used to study the molecular weight (MW) permeability dependence in the rat ileal mucosa. Absorption of the PEGs was measured by following their recirculation perfusion over a 3 hr collection period. HPLC methods were used to separate and quantitate the individual oligomers present in the solution of PEGs mixtures (MW range 330 to 1 1 22 D). In the range studied, a distinct molecular weight cutoff was not identified. Corrected for the length of ileum used in the study, over the molecular weight range 330 to 1122 D, the apparent permeability $(P_{app)$ of PEG ranged from $3.2\pm0.06\times10_{-5} cm/sec(mean\pmSEM, n=7)\; to\; 0.1\pm0.02\times10^{-5} cm/sec.$ Also, it was observed that the apparent permeability was inversely proportional to approximately $MW^{2.4}$.

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Adhesion Prevention in the Dog with Sodium Carboxymethylcellulose and Low Molecular Weight Heparin (개에서 Sodium Carboxymethylcellulose와 Low Molecular Weight Heparin(Fraxiparine$^{(R)}$)의 유착방지효과)

  • 권영삼;장인호
    • Journal of Veterinary Clinics
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    • v.16 no.1
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    • pp.50-56
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    • 1999
  • This study was carried out to compare the efficacy of sodium carboxymethyl cellulose (SCMC) with the combination of low molecular weight heparin (LMWH) and SCMC for the prevention of postoperative adhesions in the dog. After laparotomy, abrasions were made on the surface of ileal serosa in 17 dogs. The animals were randomly divided into the control group (N = 5) which received no treatment, the SCMC-treated group (N = 6), and the SCMC & LMWH-treated group (N = 6). Hematologic values were monitored before laparotomy and 1, 4, 7, 10 and 14 days after laparotomy. The location and score of adhesion were assessed at second laparotomy 3 weeks later, Although the mean adhesion score both in the SCMC-treated group (7.17${\pm}$1.17) and in the SCMC & LMWH-treated group (4.50${\pm}$1.38) was found to be significantly lower than that in the control group (9.40${\pm}$0.89) (p<0.01 and p<0.01, respectively), more favorable adhesion prevention was achieved in the SCMC & LMWH-treated group in comparison with the SCMC-treated group without any hemor-rhagic complications (p<0.01). This study could conclude that SCMC & LMWH are highly effective in prevention against postoperative adhesion in the dog.

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Synergistic Effects of Carboxymethylchitosan Fabric and Low Molecular Weight Heparin in Reducing Adhesion Formation in the Rat Uterine Horn Model (Rat에서 Carboxymethylchitosan Fabric과 Low Molecular Weight Heparin의 자궁각 유착 형성 방지 상승효과)

  • Kwon, Young-Sam;Jang, Kwang-Ho
    • Journal of Veterinary Clinics
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    • v.25 no.4
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    • pp.263-267
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    • 2008
  • This study was performed to compare the efficacy of carboxymethylchitosan fabric (CMCF) with that of the combination of CMCF and low molecular weight heparin (LMWH) for the prevention of postoperative uterine adhesion in rats. Adhesions were induced by suturing both the uterine serosa and peritoneum abrased until petechial bleeding occurred. Fourteen days later, adhesions were evaluated clinically and histopathologically. The mean tensile strength was significantly decreased in the CMCF and CMCF+LMWH groups compared to that of control group, and the CMCF+LMWH group had the lowest tensile strength. The distance of adhesion site was highest in the CMCF group and slightly decreased in the CMCF+LMWH group comparing to that of control group. The inflammatory cell infiltration and neovascularization of the CMCF group were significantly lower than those of the control group. It was observed that the damage at intestinal serosa was significantly decreased in the CMCF+LMWH group comparing to that of control group. Therefore, it was concluded that CMCF and LMWH may be useful to prevent postoperative uterine adhesion in rats.

Antioxygenic and Peroxide-decomposing Activities of Antarctic Krill Lipids (Krill 지질(脂質)의 항산화성(抗酸化性)과 과산화물(過酸化物) 분해작용(分解作用))

  • Lee, Jong-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.13 no.3
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    • pp.326-333
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    • 1984
  • The oxidation rate of krill lipids is very slow and no peroxides are accumulated even after long storage. By means of various chromatographic techniques and mass spectrophotometry, the primary antioxidant has been identified as ${\alpha}$-tocopherol. The phospholipid fractions did not show any antioxidative activity but peroxide-decomposing properties of total lipids depended upon the phospholipid contents. The peroxide-decomposing activities of phospholipids were due to the presence of polar materials generated during the storage. The most peroxide-decomposing fractions of oxidized krill lecithin by DEAE-cellulose column chromatography was low-molecule fraction (mean molecular weight: 182) and high-molecule fraction (mean molecular weight: 1942) was the next. The separation of peroxide-decomposing properties from low-molecule fraction was achieved by partitioning between chloroform and methanol/water. The methanol/water fraction showed strong peroxide-decomposing activities and main component of this fraction was assumed hydroxyamine compounds derived from choline.

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Monte Carlo Simulation of the Molecular Properties of Poly(vinyl chloride) and Poly(vinyl alcohol) Melts

  • Moon, Sung-Doo;Kang, Young-Soo;Lee, Dong-J.
    • Macromolecular Research
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    • v.15 no.6
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    • pp.491-497
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    • 2007
  • NPT Monte Carlo simulations were performed to calculate the molecular properties of syndiotactic poly(vinyl chloride) (PVC) and syndiotactic poly(vinyl alcohol) (PVA) melts using the configurational bias Monte Carlo move, concerted rotation, reptation, and volume fluctuation. The density, mean square backbone end-to-end distance, mean square radius of gyration, fractional free-volume distribution, distribution of torsional angles, small molecule solubility constant, and radial distribution function of PVC at 0.1 MPa and above the glass transition temperature were calculated/measured, and those of PVA were calculated. The calculated results were compared with the corresponding experimental data and discussed. The calculated densities of PVC and PVA were smaller than the experimental values, probably due to the very low molecular weight of the model polymer used in the simulation. The fractional free-volume distribution and radial distribution function for PVC and PVA were nearly independent of temperature.

Studies on the Suitability and Efficiency of Human Follicular Fluid as Protein Supplement in Assisted Reproductive Technology(ART);II. Effect of Human Follicular Fluid on Development of Mouse Embryos In Vitro (생식보조시술시 단백질원으로서 인간난포액의 적합성 및 효율성에 관한 연구;II. 인간난포액이 생쥐수정란의 체외발달에 미치는 효과)

  • Kim, D.H.;Chi, H.J.;Kim, J.Y.;Koo, J.J.;Chang, S.S.;Chung, K.S.
    • Clinical and Experimental Reproductive Medicine
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    • v.23 no.1
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    • pp.95-102
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    • 1996
  • This study was performed to investigate the effect of human follicular fluid (HFF) on development of mouse embryos, for evaluating the suitability of HFF as a substitutive material of human fetal cord serum in ART program. The various concentrations of HFF were added into the culture medium and the effects of HFF concentrations were examined to identify the optimal concentration of HFF for embryo development. The potency of HFF in improving embryo development was compared to that of other protein supplement. Collected HFFs were classified with the maturity of the containing oocytes; mature, immature, atretic, and then the effects of the classified HFFs on embryo development were examined. Also, HFF was separated into the low (<30,000 Da) and high (>30,000 Da) molecular weight fractions and the effects of the fractions on embryo development were investigated. The highest development rate was found in culture medium supplemented with 20% HFF, bnt this rate was reversely reduced at the concentrations of HFF higher than 20%. The development rates to the blastocyst, hatching blastocyst, attachment and outgrowth cultured in mature HFF was significantly higher than those in immature and atretic HFF, and mean cell number in blastocyst was higher in mature HFF than in immature and atretic HFF. The development rates of mouse embryos according to protein sources were significantly higher in HFF than in fetal cord serum (FCS), maternal serum (MS) and bovine serum albumin (BSA), and mean cell number in blastocyst cultured in HFF was higher than that in FCS, MS and BSA. The development rates of embryo and mean cell number in blastocyst cultured in high molecular weight fraction of HFF were higher than those in low molecular weight fraction, but the results of high molecular weight fraction were lower than those of whole HFF. Therefore, these results indicated that human mature follicular fluid was useful for improving the development of mouse embryos, which suggests a possibility that HFF also may be used efficiently for improving the culture condition in human ART program as a protein supplement.

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Separation Purification Characteristics of Rinsing Solution in Semiconductor Process using Bigh Performance Polymer Membranes ( I ) (기능성 고분자막을 이용한 반도체 공정 세정액의 분리정제특성 (I))

  • Lee Jae-Dal;Hong Young-Ki;Ro Duck-Kil;Bae Kie-Seo
    • Textile Coloration and Finishing
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    • v.17 no.3 s.82
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    • pp.34-42
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    • 2005
  • In this work, a practical separation performance was investigated on aqueous alcohol solutions, especially for iso-propyl alcohol (IPA), which is usually used during the semi- conductor rinsing process. The removal of various substances from waste aqueous IPA solutions was carried out by microfiltration with $0.1\~1{\mu}$m pore size of mean diameter as a pre-filter. Permeability and molecular weight cut-off of the functional polysulfone(PSf) ultrafiltration membrane to purify waste aqueous IPA solutions were measured through the ultrafiltration test. The solute rejection of PSf membrane had $92\%$ in 1,000ppm aqueous PEG solution with PEG molecular weight 10,000, the molecular weight cut-off had 10,000. The IPA concentration on the $CMPA-K^+$ membrane performance using pervaporation module system could be increased from $95.04 wt\%$ to more than $98.50wt\%$ in about 9hr at operation temperature of $70^{\circ}C$ using the pervaporation module system.