• 제목/요약/키워드: size exclusion

검색결과 245건 처리시간 0.025초

생분해 과정 중 용존 유기물 특성 변화에 미치는 휴믹물질의 영향 (Effects of Humic Substances on the Changes of Dissolved Organic Matter Characteristics by Biodegradation)

  • 박민혜;이보미;이태환;허진;양희정
    • 한국물환경학회지
    • /
    • 제25권3호
    • /
    • pp.419-424
    • /
    • 2009
  • Characteristics of humic substances on the changes in dissolved organic matter (DOM) characteristics by biodegradation was investigated using three types of the artificial water samples composed of glucose and Suwannee River fulvic acid (SRFA). Some selected DOM characteristics including the specific UV absorbance (SUVA), the synchronous fluorescence spectra and the molecular weight (MW) were compared for the artificial water samples before and after 28-day microbial incubation. The changes of the DOM characteristics were minimal for SRFA during the incubation whereas they were significant for glucose. SUVA, dissolved organic carbon (DOC)-normalized fluorescence intensity, and MW values of glucose increased, suggesting that such labile organic compounds could be exclusively transformed into more humidified materials by biodegradation. For glucose-SRFA mixture, the selected DOM characteristics were greater than those estimated using the assumption that the individual changes of either glucose or SRFA are conservative for the mixture of the two materials. Our results suggest that the presence of humic substances (HS) may lead to the enhancement of the formation of refractory organic materials during biodegradation of labile compounds. Detailed analyses of size exclusion chromatography (SEC) revealed that the enhancement occurred for the DOM mixture with a MW range between 500 Da to 4000 Da.

국내 3차 병원의 비만 암환자에서 각각 다른 체중 측정 공식들을 적용한 piperacillin/tazobactam의 용량 적절성 비교 연구 (Comparison of Appropriate Piperacillin/Tazobactam Doses in Korean Obese Patients with Cancer Based on Different Body Size Descriptor Equations in a Tertiary Care Hospital)

  • 김지현;양영모;윤현옥;최은주
    • 한국임상약학회지
    • /
    • 제27권2호
    • /
    • pp.83-91
    • /
    • 2017
  • Background: Piperacillin/tazobactam (TZP) is an antibiotic against a broad spectrum of gram-positive, gram-negative, and aerobic and anaerobic strains of bacteria. Due to changes in its pharmacokinetic and pharmacodynamic parameters by TZP-treated patients' renal functions and obesity, it is important to administrate and monitor TZP based on their renal functions and Body Mass Index (BMI) levels. The purpose of this study was to determine the appropriateness of administration doses of TZP based on renal functions of obese cancer patients in a tertiary hospital. Methods: This study was retrospectively conducted with obese cancer patients with $BMI{\geq}30kg/m^2$ in a tertiary hospital, Korea from September 2004 to August 2014. Data were collected through Electronic Medical Record (EMR) which contained laboratory data and TZP dosing of each patient. Results: Among 7,058 patients during the study period, 102 prescriptions were selected based on inclusion and exclusion criteria and classified by their renal functions. Although TZP should be used based on patients' renal functions to adjust its dose, its initial dose and dosing interval were consistently used without considering patients' renal functions on a regular basis. Especially, in the comparison with FDA dosing standard of TZP, approximately twice patients with $20mL/min{\leq}CrCl{\leq}40mL/min$ received domestically 4.5 g instead of 2.25 g as the TZP starting dose. Conclusion: The appropriate doses of TZP were administered to almost all of obese cancer patients; however, the recommended TZP dose was different between Korea and other countries by twice the amount. Further related studies are necessary to clearly determine the results, to optimize TZP treatment for obese patients with cancer in clinical practice, and to design and develop new TZP formulations for them in pharmaceutical industry.

농촌의료보험의 당면과제와 개선방향 (Reforming the Rural Health Insurance Programs in Korea)

  • 문옥륜
    • 농촌의학ㆍ지역보건
    • /
    • 제16권2호
    • /
    • pp.179-194
    • /
    • 1991
  • Despite its universal coverage of health insurance, the rural health insurance program(RHIP) stands at the crossroads in Korea. The RHIP has weaknesses in stability of financing, problems of inequities in the provision of health services and has suffered from high cost of running the program. The author has analyzed these problems from the perspective of health insurance policy and presented several options for improvement. First of all, this study urged the importance of a firm Governmental commitment of RHIP with the 50% subsidization of contributions as the Government had promised, instead of the current 40%. This can be justified from the 20% subsidization by the Government for the contributions of private school teachers and their dependents, who belong to richer segments of the population. Second, various cost containment measures ought to be sought curbing the rising demand for medical through strengthening health education and increasing individual responsibility, and tightening the claim review process. Third, this study requires the Government to run a demonstration project on the introduction of case payment system for primary health care. Fourth introducing an income-related cost sharing scheme is another possibility. Reforming the cost sharing formula for large medical expenditures is recommendable for a beginning. This measure can take the form of tax credit for medical expenditures of the poor. Fifth, the degree of financial adjustment among health insurance plans should be levelled up for enhancing stability of RHIP and social solidarity. Sixth, health policy should be redirected toward development of rural health resources and higher priority should be put on relieving difficulties in access to care. Seventh. the insurance plan owned-hospital needs to be developed or provision of health services in the medically underserved areas, and the need of such facilities is particularly acute for geriatric care, rehabilitation and renal dialysis, etc. Eighth, more generous insurance benefits are required of the elderly who are suffering the most : elimination of the maximum 180 days of benefit period and provision of glasses and artificial dentures, etc. Ninth. the economies of scale principle is working for the operating expenses of regional self-employed insurance plan. Thus, measures should be instituted to pursue an optimum size of health insurance plans. Lastly, excessive dependence on exclusion items is an evil so that some radical remedies are urgently required to cut them.

  • PDF

Flurbiprofen 함유 키토산 제제가 치은 섬유아세포에 미치는 영향 (Biological Effects Of Flurbiprofen Loaded Chitosan To Gingival Fibroblast)

  • 정종평;박윤정;이승진;유인철;최상묵
    • Journal of Periodontal and Implant Science
    • /
    • 제26권1호
    • /
    • pp.317-333
    • /
    • 1996
  • The main goal of periodontal regeneration is to be achieved by epithelial exclusion, periodontal ligament cell activation or alveolar bone regeneration. The purpose of this study was to investigate on the physico- chemical and biological characteristics of biodegradable chitosan beads. Chitosan beads were fabricated by ionic gelation with sodium tripolyphosphate and they had the size in 300um diameter. As therapeutic agent, flurbiprofen was incorporated into the beads by 10, 20% loading contents. The release of drugs from the chitosan beads was measured in vitro. Also, biological activity tests of flurbiprofen loaded chitosan beads including cytotoxicity test, ihhibition of $IL-1{\beta}$ production, suppression to $PGE_2$ production, collagenase inhibition test, the ability of total protein synthesis, and tissue response were evaluated. The amount of flurbiprofen released from chitosan was 33-50% during 7 days. Minimal cytotoxicity was observed in chitosan beads. Flurbiprofen released from chitosan beads significantly suppressed the $IL-1{\beta}$ production of monocyte, $PGE_2$ production and markedly inhibited collagenase activity. Meanwhile, flurbiprofen released from this system showed increased ability for protein synthesis. Throughout 4 -week implantation period, no significant inflammatory cell infiltrated around chitosan bead and also fibroblast like cell types at the beads - tissue interface were revealed with gradual degradation of implanted chitosan beads. From these results, it was suggested that flurbiprofen loaded chitosan beads can be effectively useful for biocompatible local delivery system in periodontal regeneration.

  • PDF

붕장어(Conger myriaster)의 뇌로부터 Oxytocin-related Peptide, Isotocin의 정제 (Purification of Oxytocin-related Peptide, Isotocin from the Brain of Conger Eel Conger myriaster)

  • 고혜진;김찬희;김은정;김인혜;안상현;손희영;박진일;박희연;윤호동;박남규
    • 한국수산과학회지
    • /
    • 제38권5호
    • /
    • pp.286-290
    • /
    • 2005
  • Oxytocin (OT)-related peptide, isotocin was purified from the brain extract of conger eel (Conger myriaster) using reverse-phase, ion-exchange and size exclusion high performance liquid chromatography (HPLC). The sequence of the peptide, with a molecular weight of 967.30 Da, was determined as Cys-Tyr-Ile-Ser-Asn­Cys-Pro-Ile-Gly-$NH_2$, where the Cys between 1st and 6th residues made an intramolecular disulfide bridge by the automated amino acid sequence analysis and MALDI-TOF mass spectrometry. The sequence was confirmed by identical elution with the purified and synthetic peptide using the HPLC system. As a result of homology investigation, the primary structure of this peptide was the same as that of OT -superfamily member, isotocin. The synthetic peptide showed a contractile activity at a minimal effective concentration of $10^{-7}M$ on the intestinal smooth muscle of goldfish (Carassius auratus).

pH Effect on the Structure of Reduced NifU-like Protein from Helicobacter pylori

  • Lee, Ki-Young;Kim, Ji-Hun;Bae, Ye-Ji;Lee, Bong-Jin
    • 한국자기공명학회논문지
    • /
    • 제19권3호
    • /
    • pp.106-111
    • /
    • 2015
  • Helicobacter pylori (H. pylori) survives in acidic and fluctuating pH conditions of the stomach. The pH effect on H. pylori proteins is important for the advanced understanding of its evolution and viability, although this bacterium has the molecular machinery that neutralizes the acidic condition. HP1492 is known as a conserved NifU-like protein from H. pylori. NifU is a nitrogen fixation protein that mediates the transfer of iron-sulfur (Fe-S) cluster to iron-sulfur proteins like ferredoxin. Commonly, the monomeric reduced state of NifU can be converted to the dimeric oxidized state by intermolecular disulfide bond formation. Because it remains unclear that HP1492 actually behaves as known NifU protein, we first found that this protein can adopt both oxidized and reduced forms using size exclusion chromatography. Circular dichroism experiment showed that HP1492 is relatively well-structured at pH 6.5, compared to other pH conditions. On the basis of the backbone resonance assignment of HP1492, we further characterized the residues that are sensitive to pH using NMR spectroscopy. These residues showing large chemical shift changes could be mapped onto the secondary structure of the protein. Our results could provide the foundation for structural and biophysical studies on a wide spectrum of NifU proteins.

황산기가 도입된 피브로인의 제조 및 특성 (Preparation and Characterization of Sulfated Fibroin)

  • 정대철;이신영;허원
    • KSBB Journal
    • /
    • 제24권5호
    • /
    • pp.458-462
    • /
    • 2009
  • 황산 수용액에 재생 피브로인을 녹이고 가열하여 황산을 반응물과 동시에 촉매로 사용하여 황산-피브로인을 제조 하였다. 황산의 농도 및 반응온도를 달리하여 얻어진 시료로부터 적외선 흡광 스펙트럼, UV 흡광 스펙트럼, NMR 및 GPC를 사용하여 반응조건에 따른 황산기의 도입 정도 및 피브로인 분자의 분해 정도를 분석하였다. 황산-피브로인의 수율은 5%의 황산을 사용하여 $60^{\circ}C$에서 반응시킬 때 가장 높았으며 적외선 흡광 스펙트럼의 $1109\;cm^{-1}$의 피크가 나타내는 도입된 황산기의 량은 황산의 농도가 증가하면 같이 증가하였다. 단백질에 도입된 황산기는 피브로인 분자를 주로 구성하고 있는 세린 및 타이로신의 hydroxyl 그룹과 반응하여 O-sulfate ester를 형성할 것으로 예상되는데, 이는 274 nm에서의 UV 흡광도의 감소 및 $3300\;cm^{-1}$의 적외선 흡광 스펙트럼의 감소가 관찰되는 결과와 일치하였다. GPC 분석을 통하여 황산-피브로인이 가수 분해되어 원래 피브로인의 분자량 보다 분자량이 작으며 동시에 가수분해된 저분자 황산 피브로인 펩타이드와 덜 가수분해된 비교적 분자량이 큰 펩타이드로 구성되어 있음이 확인되고 있다.

폐감률피에서 추출한 limonene 오일의 세정성에 관한 연구 (A Study on the Cleaning Efficiency using the d-Limonene Oil Extracted in Wasted Mandarin Peels)

  • 송민경;김윤신;임호섭;오은하
    • 한국응용과학기술학회지
    • /
    • 제27권2호
    • /
    • pp.107-113
    • /
    • 2010
  • The object of this research is to conform of practicable possibility and recycling of producing junk after citrus fruits is processed. With extracting d-limonene oil that have 70~90% a component of oil out of junk citrus peel, making certain the about 12000ppm concentration of it. Limonene derived from citrus in jeju using conventional synthetic detergents can be replaced with the development of environmentally friendly natural detergent investigated the possibility. Mostly due to ocean dumping, disposal and cause environmental problems by recycling natural citrus cleaner alternative to the research conducted on the possibility. Cleaning efficiency with temperature did not affect the largest concentrations were able to identify the difference between cleaning efficiency. At least 10% of the d-limonene oil could be from the cleaning performance, increasing the concentration of the cleaning efficiency was increased in size. Ultrasonic is very high removal efficiency under the conditions shown in the cause of pure self-generated ultrasonic cleaning power as co-effects of d-limonene oil appears to chemical cleaning effect of ultrasonic cavitation occurs in the physical cleaning effect due to a combination of synergistic stability is maximized by low concentrations of d-limonene oil in a short time showed an excellent cleaning ability. Having the ability of cleaning at the same time, considering the side recycling in the junk citrus peels reflects possibility of basic materials utility eco-friendly in the skin soap, bath soap, cosmetics etc, through ability of exclusion a contaminant in based cleaning effect(EC) it can prospect substitution effect environmentally in the pre existence synthetic detergents.

Antitumor Effect of Soluble ${\beta}$-1,3-Glucan from Agrobacterium sp. R259 KCTC 1019

  • Shim, Jung-Hyun;Sung, Ki-Joong;Cho, Min-Chul;Choi, Won-A;Yang, Young;Lim, Jong-Seok;Yoon, Do-Young
    • Journal of Microbiology and Biotechnology
    • /
    • 제17권9호
    • /
    • pp.1513-1520
    • /
    • 2007
  • [ ${\beta}$ ]-1,3-Glucans enhance immune reactions such as antitumor, antibacterial, antiviral, anticoagulatory, and wound healing activities. ${\beta}$-1,3-Glucans have various functions depending on the molecular weight, degree of branching, conformation, water solubility, and intermolecular association. The molecular weight of the soluble glucan was about 15,000 as determined by a high-performance size exclusion chromatography. From the infrared (IR) and $^{13}C$ NMR analytical data, the purified soluble glucan was found to exclusively consist of ${\beta}$-D-glucopyranose with 1,3 linkage. We tested the immunestimulating activities of the soluble ${\beta}$-1,3-glucan extracted from Agrobacterium sp. R259 KCTC 1019 and confirmed the following activities. IFN-$_{\gamma}$ and each cytokines were induced in the spleens and thymus of mice treated with soluble ${\beta}$-1,3-glucan. Adjuvant effect was observed on antibody production. Nitric oxide was synthesized in monocytic cell lines treated with ${\beta}$-1,3-glucan. The cytotoxic and antitumor effects were observed on various cancer cell lines and ICR mice. These results strongly suggested that this soluble ${\beta}$-1,3-glucan could be a good candidate for an immune-modulating agent.

Expression, Purification, Crystallization and Preliminary X-Ray Crystallographic Analysis of CnrX from Cupriavidus metallidurans CH34

  • Kim, Kook-Han;Jung, Eun-Jung;Im, Ha-Na;Lelie, Daniel Van Der;Kim, Eunice Eun-Kyeong
    • Journal of Microbiology and Biotechnology
    • /
    • 제18권1호
    • /
    • pp.43-47
    • /
    • 2008
  • The nickel and cobalt resistance of Cupriavidus metallidurans CH34 is mediated by the CnrCBA efflux pump encoded by the cnrYHXCBAT metal resistance determinant. The products of the three genes cnrYXH transcriptionally regulate expression of cnr. CnrY and CnrX are membrane-bound proteins, probably functioning as anti-sigma factors, whereas CnrH is a cnr-specific extracytoplasmic functions (ECF) sigma factor. The periplasmic domain of CnrX (residues 29-148) was cloned as a N-terminal His-tagged protein, expressed in Escherichia coli, and purified using affinity chromatography and gel filtration. The molecular mass was estimated to be about 13.6kDa by size exclusion chromatography, corresponding to a monomer. The tetragonal bipyramid crystals were obtained by mixing an equal volume of protein in 50mM Tris-HCl, pH 7.5, 1% glycerol, 100mM NaCl, 1mM DTT, and the reservoir solution of 15% w/v PEG 2000, 100mM lithium chloride at 277K in 2-4 days using hanging drop vapor diffusion. The protein concentration was 24mg/ml. The crystal that diffracted to $2.42{\AA}$ resolution belongs to space group $P4_1\;or\;P4_3$ with unit cell parameters of $a=b=32.14{\AA},\;c=195.31{\AA},\;{\alpha}={\beta}={\gamma}=90^{\circ}$, with one molecule of CnrX in the asymmetric unit.