• Title/Summary/Keyword: time-dependent effect

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Investigation on the Surface Hydrophobicity and Aggregation Kinetics of Human Calprotectin in the Presence of Calcium

  • Yousefi, Reza;Ardestani, Susan K.;Saboury, Ali Akbar;Kariminia, Amina;Zeinali, Madjid;Amani, Mojtaba
    • BMB Reports
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    • v.38 no.4
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    • pp.407-413
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    • 2005
  • Calcium and zinc binding protein, calprotectin is a multifunctional protein with broad spectrum antimicrobial and antitumoural activity. It was purified from human neutrophil, using a two-step ion exchange chromatography. Since surface hydrophobicity of calprotectin may be important in membrane anchoring, membrane penetration, subunits oligomerization and some biological roles of protein, in this study attempted to explore the effect of calcium in physiological range on the calprotectin lipophilicity. Incubation of human calprotectin ($50\;{\mu}g/ml$) with different calcium concentrations showed that 1-anilino-8-naphthalene sulfonic acid (ANS) fluorescence intensity of the protein significantly elevates with calcium in a dose dependent manner, suggesting an increase in calprotectin surface hydrophobicity upon calcium binding. Our study also indicates that calcium at higher concentrations (6, 8 and 10 mM) induces aggregation of human calprotectin. Our finding demonstrates that the starting time and the rate constant of calprotectin aggregation depend on the calcium concentration.

Experimental Studies on Joinability of SWS 490A High Tension Steel using Acoustic Emission Signals (음향방출 신호를 이용한 SWS 490A 고장력강의 접합성 평가에 대한 실험적 연구)

  • 이장규;우창기;윤종희;조진호;조대희;박성완;김봉각;구영덕
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.10a
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    • pp.40-48
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    • 2004
  • The object of this study is to investigate the effect of joinability by using acoustic emission (AE) signals and doing a pattern recognition for weld heat affected zone (HAZ) in tensile testing. This study was carried out an SWS 490A high tension steel for electric shielded metal arc welding (SMAW), $CO_2$ gas arc welding and TIG welding. And correspondingly, the root openings are 3, 4 and 2.8mm. The results of the tensile test of weld HAZ come out electric shield arc welding > $CO_2$ gas arc welding > TIG welding in case of single welding. It is believed that this is a phenomenon where difference of its root opening or base metal thickness. Also, the technique of AE is ideally suited to study variables which control time and stress dependent fracture or damage process in metallic materials.

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Protective Effects of Ukyium(우귀음, Yougui-yin) in Zinc-induced Apoptosis of C6 Glial Cells (우귀음이 Zinc에 의한 신경교세포의 고사(Apoptosis)에 미치는 영향)

  • 이영구;문병순
    • The Journal of Korean Medicine
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    • v.22 no.3
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    • pp.63-73
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    • 2001
  • Objectives : The objective of the current study is to determine the protective effect of Ukyium(Yougui-yin) on the apoptosis induced by zinc. Methods : Zinc is known to generate reactive oxygen species (ROS), including superoxide anion ($O_2$) and hydrogen peroxide ($H_2O_2$), which eventually contribute to cytotoxicity in a variety of cell types. We investigated the viablity of cells, $H_2O_2$ generation, chromatin condensation and nuclear fragmentation in Hoechst dye staining and $IkB-{\alpha}$ degradation in C6 glial cells of $ZnCl_2$ between pretreatment- and not pretreatment-group with Ukyium. The former methods were researched by Time- and Dose-dependent manners. Results : We demonstrated that pretreatment with Ukyium prevented zinc-induced cell death of C6 glial cells and apoptotic characteristics including chromatin condensation and nuclear fragmentation. Ukyium also prevented $H_2O_2-induced$ cell death. We further confirmed that Ukyium decreased zinc-induced generation of $H_2O_2$ and inhibited degradation of $IkB-{\alpha}$ by zinc in C6 glial ceHs. Conclusions : These data indicated that Ukyium (Yougui-yin) prevents zinc-induced apoptotic death of C6 glial cells via inhibition of ROS generation, such as $H_2O_2$ as well as inhibition of $IkB-{\alpha}$ degradation.

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The Effect of Financial Restructuring on the Overall Financial Performance of the Commercial Banks in Vietnam

  • DUONG, Tam Thanh Nguyen;PHAN, Hai Thanh;HOANG, Tien Ngoc;VO, Tien Thuy Thi
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.9
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    • pp.75-84
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    • 2020
  • The study investigates and measures the impact of financial restructuring on overall financial performance of commercial banks in Vietnam. Survey data for this research were collected from audited financial reports of 28 commercial banks in Vietnam, for the period from 2008 to 2018. In the study, we have built a model of econometric regression with the dependent variable being financial results measured through ROA and ROE. The research methods used include Pooled Ordinary Least Square Model (POLS), Fixed Effects Model (FEM), Random Effects Model (REM), and different Generalized Method of Moments (GMM). The results showed that the account payables restructuring and owners' equity restructuring are much needed. Increasing the owners' equity, decreasing the account payables would improve the overall financial performance, bad debts restructuring to decrease bad debts would also improve the financial performance as well. However, the financial restructuring in the period 2012-2015 and 2016-2018, indeed worsen the financial performance during those times. The findings of this study suggest that the evaluation of the financial performance after restructuring of commercial banks in Vietnam must be based on longer data. At the same time, it is necessary to examine differences between various banking groups to draw accurate conclusions on financial performance.

Effect of Caffeine on Coronary Circulation and Calcium Release in Isolated Guinea Pig Hearts (Guinea Pig Heart의 관상동맥 순환기능과 Calcium Release에 있어서 Caffeine이 미치는 영향)

  • 김은지
    • Journal of Nutrition and Health
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    • v.25 no.7
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    • pp.597-607
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    • 1992
  • The present study examined effects of caffeine on coronary circulation myocardial oxygen me-tabolism and calcium release in isolated perfused guinea pig hearts. Intracoronary caffeine({{{{ {10 }^{-5 } }}}}∼{{{{ { 10}^{-3 } }}}}M) was employed for 10 minutes to measure coronary perfusate flow(CF) and coronary vascular sresistance(CVR) at a constant coronary perfusion pressure of 80 cmH2O Perfusate myocardial oxygen consumption(MVO2) and percent oxygen extraction(%EC2) were calcula-ted. In addition calcium contents in both perfusate samples were measured to calculate calcium release in coronary venous effluent. Caffeine significantly decreased CF and increased CVR during 10 minutes of caffeine perfusion regardless of dose of caffeine perfused exhibiting time-response. While % EO2 was significantly enhanced with caffeine MVO2 was markedly reduced. The coronary venous perfusate pH dcreased during the perfusion with caffeine. These changes were consistent with caffeine-induced metabolic acidosis. Calcium release appeared to be dose-dependent and high dose of caffeine greatly increased venous calcium release even 2 minutes after perfusion with carffeine. These finding in dicate that caffeine produced coronary vasoconst-riction with increased calcium release in isolated perfused guinea pig hearts. Additionaly this vasoconstrictor response mignt be due tin part to the direct actions of caffeine.

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Effects of Oral Gargling with Aroma Solution in Psychiatric Inpatients: A Non-Randomized Controlled Trial (입원 정신질환자의 아로마용액 구강함수 효과: 비무작위 대조군 설계)

  • Jung, Yun Ah;Kim, Hee Sook
    • Journal of Korean Academy of Nursing
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    • v.50 no.2
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    • pp.200-209
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    • 2020
  • Purpose: The purpose of this study was to examine the effects of oral gargling with an aromatic solution on xerostomia, objective oral status, and oral health-related quality of life in psychiatric inpatients. Methods: A nonequivalent control group with a non-synchronized design was used in this study. The experimental group (n=34) received oral gargling with an aroma solution, while the control group (n=33) gargled with 0.9% normal saline. Dependent variables were measured at pre-, post-, and follow-up test. Data were analyzed using an χ2-test, Fisher's exact probability test, t-tests, and repeated measures ANOVA using SPSS/WIN v.21.0. Results: After the intervention, significant differences were revealed in xerostomia (F=15.30, p<.001), objective oral status (F=38.44, p<.001), and oral health-related quality of life (F=62.70, p<.001) with an interaction effect between group and time. Conclusion: These findings indicate that gargling with an aroma solution is more effective than 0.9% normal saline for the oral health of psychiatric inpatients. Therefore gargling with an aroma can be safely recommended as a brief, economical, and positive intervention in clinical settings.

Effects of substance P on mineralization markers and heme oxygenase-1 Expression in human immortalized periodontal ligament cells

  • Cho, You-Min;Suh, Chung-Hwan;Chun, Sang-Woo;Kim, Eun-Cheol;Kang, Kyung-Hwa
    • International Journal of Oral Biology
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    • v.33 no.4
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    • pp.131-135
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    • 2008
  • Substance P (SP) is known to be expressed in the nerve fibers of dental pulp and periodontal tissues. It was recently reported that SP expression increased in response to orthodontic force. In the present study, we investigated the effect of SP on expression of mineralization markers and heme oxygenase-1 (HO-1) in human immortalized periodontal ligament (IPDL) cells. Cell viability was measured using a 3,4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide (MTT) assay. The expression of mineralization markers, including alkaline phosphatase (ALP), osteonectin (ON) and bone sialoprotein (BSP), and heme oxygenase-1 (HO-1) was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. SP did not significantly change human IPDL cell viability, with the exception of the 24 hour treatment group. Treatment of human IPDL cells with $10^{-10}$ to $10^{-4}M$ SP upregulated mineralization marker and HO-1 expression in a time- and concentration-dependent manner. Our results suggest that SP may modulate osteoblastic cell differentiation of human IPDL cells through a mechanism involving HO-1 expression.

A Study on Parameters Measured during Small Punch Creep Testing (소형펀치 크리프 시험중 측정하는 변수에 대한 연구)

  • Park, Tae-Gyu;Sim, Sang-Hun;Yun, Gi-Bong;Jang, Chang-Hui
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.1
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    • pp.171-178
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    • 2002
  • An effect is made in this study to deepen understanding of small punch(SP) creep testing which has been a round for about 10 years as a substitute for the conventional uniaxial creep testing. Even though considerable numbers of SP creep test program have been performed, most of the tests were aimed at measuring creep rupture lives only. Very flew studies showed interest on the meaning of what we were really measuring during the SP creep tests. In this paper meanings of the parameters measured during the SP creep testing, such as punch load and punch displacement rate are investigated using finite element analysis. It was shown that the measured parameters must represent the stress and strain rates of the material at the annular region located at about 0.65 mm from the center of the SP specimen. The material in this location would go through constant maximum stress and strain rate during the testing. Experimental verification is also discussed.

Characteristics of the Purple Pigment Compound in Halophytic Plant, Suaeda japonica (내염성 식물 칠면초 (Suaeda japonica )가 갖는 자색 색소의 특징)

  • Chung, Sang-Ho
    • Proceedings of the Korea Contents Association Conference
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    • 2013.05a
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    • pp.361-362
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    • 2013
  • As one of the steps toward understanding how the plant is well adapted to strongly saline habitats, the purple pigment compound that is accumulated in Suaeda japonica was extracted and characterized. The extracted pigment compound exhibited typical characteristics of betacyanin that were represented by water solubility, pH- and temperature-dependent color changes, sensitivity to light, UV-Vis spectra, and gel electrophoretic migration pattern. LC-MS of the extracted pigment compound showed the presence of two major protonated molecular ions ($[M+H]^+$) at m/z 651.1 and m/z 827.1. According to the DPPH assay, it was found to have an antioxidant activity that is linearly increased in proportion to the reaction time for up to 30 min, and the activity was comparable to that of control BHA at 9.0 mg/ml. The cytotoxic activity against several tumor cell lines was also examined following the MTT assay. The significant growth inhibitory effect was observed on two tumor cell lines, SW-156 (human kidney carcinoma) and HEC-1B (human endometrial adenocarcinoma). Probably, the pigment compound may function as an osmolyte to uphold halotolerant physiological processes in saline environment.

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A Study on Blend Effect of Fuel in Flame Spread Along An One-Dimensional Droplet Array (일차원 액적 배열의 화염 퍼짐에 있어서 연료의 혼합 효과에 관한 연구)

  • Park, Jeong;Kobayashi, Hideaki;Niioka, Takashi
    • Journal of the Korean Society of Combustion
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    • v.3 no.2
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    • pp.1-11
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    • 1998
  • Experimental investigation on flame spread of blended fuel droplet arrays has been conducted for droplet diameters of 1.0mm and 0.75mm using high-speed chemiluminescence images of OH radical. The flame spread rate is measured with blended fuel composition, droplet diameter, and droplet spacing. Flame spread is categorized into two: a continuous mode and an intermittent one. There exist a limit droplet spacing, above which flame does not spread, and a droplet spacing of maximum flame spread, which is closely related to flame diameter. It is seen that flame spread rate is mainly dependent upon the relative position of flame zone within a droplet spacing. In case of large droplet, the increase of % volume of Heptane induces the shift of limit droplet spacing to a larger spacing since volatile Heptane plays a role of an enhancer of flame spread rate. In case of small droplet, the increase of % volume of Heptane leads to the shift of limit droplet spacing to a smaller droplet spacing. This is so because of the delayed chemical reaction time by the rapid increase of mass flux of fuel vapor for small droplet.

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