• Title, Summary, Keyword: short column

Search Result 246, Processing Time 0.033 seconds

Effect of Gamitonggyu-tang on Secretion of Airway Mucin and Contractility of Tracheal Smooth Muscle (가미통규탕(加味通竅湯)이 호흡기 뮤신 분비 및 기관 평활근 긴장도에 미치는 영향)

  • Lee, Nam-Yeol;Han, Jae-Kyung;Kim, Yun-Hee
    • The Journal of Pediatrics of Korean Medicine
    • /
    • v.21 no.3
    • /
    • pp.109-124
    • /
    • 2007
  • Objectives In the present study, the author intended to investigate whether Gamitonggyu-tang (GTT) significantly affects (since the subject is GTT, you need an 's') in vivo and in vitro mucin secretion from airway epithelial cells. Methods In vivo experiment, mice's mucin which is on a hypersecretion of an airway, mice's tracheal goblet cells in hyperplasia and mice's intraepithelial mucosubstances were exposed with SO2 for 3 weeks. Effects of orally-administered GTT for 1 week on in vivo mucin secretion and hyperplasia of tracheal goblet cells were assessed by using enzyme-linked immunosorbent assay (ELISA) and staining goblet cells with alcian blue. In vitro experiment, confluent hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled with 3H-glucosamine for 24 hrs and chased for 30 min in the presence of GTT to figure out the effectiveness of 3H-mucin secretion. Total elution profiles of control spent media and treatment sample through Sepharose CL-4B column were analyzed.Possible cytotoxicities of each agent were assessed by measuring lactate dehydrogenase (LDH) release. Also, the effect of GTT on contractility of isolated tracheal smooth muscle was investigated. Results (1) GTT inhibited hypersecretion of in vivo mucin. However, it did not affect the increase the number of goblet cells (2) GTT significantly increased mucin release from cultured HTSE cells, without significant cytotoxicity (3) GTT chiefly affected the 'mucin' secretion and did not affect the secretion of the other releasable glycoproteins with less molecular weight than mucin (4) GTT did not affect Ach-induced contraction of isolated tracheal smooth muscle.Conclusions This result suggests that GTT can increase mucin secretion during short-term treatment (in vitro) whereas it can inihibit hypersecretion of mucin during long-term treatment (in vivo). The author suggests that the effect GTT with their components should be further investigated and it is valuable to find from oriental medical prescriptions, novel agents which might regulate mucin secretion from airway epithelial cells.

  • PDF

Development and Validation of an HPLC Method for the Pharmacokinetic Study of Fenoprofen in Human (페노프로펜 체내동태 연구를 위한 혈청 중 페노프로펜의 HPLC 정량법 개발 및 검증)

  • Cho, Hye-Young;Kang, Hyun-Ah;Kim, Yoon-Gyoon;Sah, Hong-Kee;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
    • /
    • v.35 no.6
    • /
    • pp.423-429
    • /
    • 2005
  • A selective and sensitive reversed-phase HPLC method for the determination of fenoprofen in human serum was developed, validated, and applied to the pharmacokinetic study of fenoprofen calcium. Fenoprofen and internal standard, ketoprofen, were extracted from human serum by liquid-liquid extraction with diethyl ether and analyzed on a Luna C18(2) column with the mobile phase of acetonitrile-3 mM potassium dihydrogen phosphate (32:68, v/v, adjusted to pH 6.6 with phosphoric acid). Detection wavelength of 272 nm and flow rate of 0.25 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^{3}$ factorial design using a fixed fenoprofen concentration $(2\;{\mu}g/mL)$ with respect to its peak area and retention time. And also, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of $0.05-100\;{\mu}g/mL$ with correlation coefficients greater than 0.999. The lower limit of quantification using 1 mL of serum was $0.05\;{\mu}g/mL$, which was sensitive enough for pharmacokinetic studies. The overall accuracy of the quality control samples ranged from 92.27 to 109.20% for fenoprofen with overall precision (% C.V.) being 5.51-11.71 %. The relative mean recovery of fenoprofen for human serum was 81.7%. Stability (freeze-thaw, short and long-term) studies showed that fenoprofen was not stable during storage. But, extracted serum sample and stock solution were allowed to stand at ambient temperature for 12 hr prior to injection without affecting the quantification. The peak area and retention time of fenoprofen were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of fenoprofen in human serum samples for the pharmacokinetic studies of orally administered Fenopron tablet (600 mg as fenoprofen) at three different laboratories, demonstrating the suitability of the method.

Development and Validation of an HPLC Method for the Pharmacokinetic Study of Fexofenadine in Human (테르페나딘 체내동태 연구를 위한 혈청 중 펙소페나딘의 HPLC 정량법 개발 및 검증)

  • Cho, Hye-Young;Kang, Hyun-Ah;Kim, Yoon-Gyoon;Choi, Hoo-Kyun;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
    • /
    • v.35 no.6
    • /
    • pp.437-443
    • /
    • 2005
  • A rapid, selective and sensitive reversed-phase HPLC method for the determination of a major metabolite of terfenadine, fexofenadine, in human serum was developed, validated, and applied to the pharmacokinetic study of terfenadine. Fexofenadine and internal standard, haloperidol were extracted from human serum by liquid-liquid extraction with acetonitrile and analyzed on a $Symmetry^{TM}$ C8 column with the mobile phase of 1% triethylamine phosphate (pH 3.7)-acetonitrile (67:33, v/v, adjusted to pH 5.6 with triethylamine). Detection wavelength of 230 nm for excitation, 280 nm for emission and flow rate of 1.0 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^{3}$ factorial design using a fixed fexofenadine concentration (50 ng/mL) with respect to its peak area and retention time. In addition, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 10-500 ng/mL with correlation coefficients greater than 0.999. The lower limit of quantification using 0.5 mL of serum was 10 ng/mL, which was sensitive enough for the pharmacokinetic studies of terfenadine. The overall accuracy of the quality control samples ranged from 95.70 to 114.58% for fexofenadine with overall precision (% C.V.) being 3.53-14.39%. The relative mean recovery of fexofenadine for human serum was 90.17%. Stability studies (freeze-thaw, short-term, extracted serum sample and stock solution) showed that fexofenadine was stable during storage, or during the assay procedure in human serum. However, the storage at $-70^{\circ}C$ for 4 weeks showed that fexofenadine was not stable. The peak area and retention time of fexofenadine were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of fexofenadine in human serum samples for the pharmacokinetic studies of orally administered Tafedine tablet (60 mg as terfenadine) at three different laboratories, demonstrating the suitability of the method.

Three-dimensional Algal Dynamics Modeling Study in Lake Euiam Based on Limited Monitoring Data (제한된 측정 자료 기반 의암호 3차원 조류 예측 모델링 연구)

  • Choi, Jungkyu;Min, Joong-Hyuk;Kim, Deok-Woo
    • Journal of Korean Society on Water Environment
    • /
    • v.31 no.2
    • /
    • pp.181-195
    • /
    • 2015
  • Algal blooms in lakes are one of major environmental issues in Korea. A three-dimensional, hydrodynamic and water quality model was developed and tested in Lake Euiam to assess the performance and limitations of numerical modeling with multiple algal groups using field data commonly collected for algal management. In this study, EFDC was adopted as the basic model framework. Simulated vertical profiles of water temperature, dissolved oxygen and nutrients monitored at five water quality monitoring stations from March to October 2013, which are closely related to algal dynamics simulation, showed good agreement with those of observed data. The overall spatio-temporal variations of three algal groups were reasonably simulated against the chlorophyll-a levels of those estimated from the limited monitoring data (chlorophyll-a level and cell numbers of algal species) with the RMSEs ranging from 2.6 to $17.5mg/m^3$. Also, note that $PO_4-P$ level in the water column was a key limiting factor controlling the growth of three algal groups during most of simulation period. However, the algal modeling results were not fully attainable to the levels of observation during short periods of time showing abrupt increase in algae throughout the lake. In particular, the green algae/cyanobacteria and diatom simulations were underestimated in late June to early July and early October, respectively. The results shows that better understanding of internal algal processes, neglected in most algal modeling studies, is necessary to predict the sudden algal blooms more accurately because the concentrations of external $PO_4-P$ and specific algal groups originated from the tributaries (mainly, dam water releases) during the periods were too low to fully capture the sharp rise of internal algal levels. In this respect, this study suggests that future modeling efforts should be focused on the quantification of internal cycling processes including vertical movement of algal species with respect to changes in environmental conditions to enhance the modeling performance on complex algal dynamics.

Evaluation for Deformability of RC Members Failing in Bond after Flexural Yielding (휨항복 후 부착파괴하는 철근콘크리트 부재의 부착 연성 평가)

  • Choi, Han-Byeol;Lee, Jung-Yoon
    • Journal of the Korea Concrete Institute
    • /
    • v.24 no.3
    • /
    • pp.259-266
    • /
    • 2012
  • A general earthquake resistant design philosophy of ductile frame buildings allows beams to form plastic hinges adjacent to beam-column connections. In order to carry out this design philosophy, the ultimate bond or shear strength of the beam should be greater than the flexural yielding force and should not degrade before reaching its required ductility. The behavior of RC members dominated by bond or shear action reveals a dramatic reduction of energy dissipation in the hysteretic response due to the severe pinching effects. In this study, a method was proposed to predict the deformability of reinforced concrete members with short-span-to-depth-ratios, which would result in bond failure after flexural yielding. Repeated or cyclic loading produces a progressive deterioration of bond that may lead to failure at lower cyclic bond stress levels. Accumulation of bond damage is caused by the propagation of micro-cracks and progressive crushing of concrete in front of the lugs. The proposed method takes into account bond deterioration due to the degradation of concrete in the post yield range. In order to verify bond deformability of the proposed method, the predicted results were compared with the experimental results of RC members reported in the technical literature. Comparisons between the observed and calculated bond deformability of the tested RC members showed reasonably good agreement.

Case Study on Economical Fabrication and Erection of Steel Structure and Reduction in Field Erection Time (경제적 철골제작$\cdot$설치 및 공기단축 사례분석연구)

  • Ahn Jae-Bong;Choi Yoon ki
    • Korean Journal of Construction Engineering and Management
    • /
    • v.5 no.5
    • /
    • pp.183-192
    • /
    • 2004
  • Even in Korea the number of steel structure buildings that allow internal space and easy change of their layouts in accordance with the purpose of buildings and box-type steel bridges constructed with thick plates with thickness in a rage just from a few $\beta$AE to \$100\beta$AE is increasing these days and therefore, domestic fabrication and processing technology of members for steel structures is being improved at a pace faster than in the past to meet the growing requirements of consumers for high reliability on quality control on the related steel structures. However, most domestic fabricators os steel structures who are turning out their steel products in accordance with the designs prepared by engineering companies in their respective works for the sake of cost cut more than anything else, hesitating to introduce any advanced new technology into themselves. In the case of the steel structure design application for small and mid-size buildings in particular, it is quite meaningful not only for those who are involved in steel structure business, but also for the people working at construction work fields to review the result of the study on the connections of steel structure members deigned to obtain superb quality of steel structures within short period for steel fabrication and erection at fields in economical ways, as there is a glowing tendency seeking standardization of connection of steel structure members as well as whole structure together with the development on design of construction system of buildings including their exterior and interior decoration materials, manufacture of the related members and fabrication technique structure. This paper has been prepared with the aim to review the peculiar characteristics of buildings constructed with the main frames of steel structures and actual cases of the change made ing the connections between steel structure columns and between columns and girder members in order to reduce the work period necessary for fabrication and erection of steel structures at the maximum as well as the some examples of steel structures fabricated through automatic welding by robots for box-type columns in addition to the description of the problems found in the course of fabricating those steel structures, suggesting possible counter-measures to solve them.