• Title/Summary/Keyword: Chemical test

Search Result 4,776, Processing Time 0.033 seconds

A Combined Pharmacophore-Based Virtual Screening, Docking Study and Molecular Dynamics (MD) Simulation Approach to Identify Inhibitors with Novel Scaffolds for Myeloid cell leukemia (Mcl-1)

  • Bao, Guang-Kai;Zhou, Lu;Wang, Tai-Jin;He, Lu-Fen;Liu, Tao
    • Bulletin of the Korean Chemical Society
    • /
    • v.35 no.7
    • /
    • pp.2097-2108
    • /
    • 2014
  • Chemical feature based quantitative pharmacophore models were generated using the HypoGen module implemented in DS2.5. The best hypothesis, Hypo1, which was characterized by the highest correlation coefficient (0.96), the highest cost difference (61.60) and the lowest RMSD (0.74), consisted of one hydrogen bond acceptor, one hydrogen bond donor, one hydrophobic and one ring aromatic. The reliability of Hypo1 was validated on the basis of cost analysis, test set, Fischer's randomization method and GH test method. The validated Hypo1 was used as a 3D search query to identify novel inhibitors. The screened molecules were further refined by employing ADMET, docking studies and visual inspection. Three compounds with novel scaffolds were selected as the most promising candidates for the designing of Mcl-1 antagonists. Finally, a 10 ns molecular dynamics simulation was carried out on the complex of receptor and the retrieved ligand to demonstrate that the binding mode was stable during the MD simulation.

Pervaporation of TFEA/MA/Water Mixtures through PVA Composite Membranes

  • Ahn, Sang-Man;Kim, Jeong-Hoon;Lee, Yong-Taek;Lee, Soo-Bok
    • Proceedings of the Membrane Society of Korea Conference
    • /
    • 2005.11a
    • /
    • pp.133-147
    • /
    • 2005
  • In order to investigate applicability for 2,2,2-trifluoroethyl methacrylate (TFEMA) produced by esterification of 2,2,2-trifluoroethanol(TFEA) and methacrylic acid(MA) using pervaporation membrane, poly(vinyl alcohol) (PVA) composite membranes were prepared with glutaraldehyde(GA) onto porous polyethersulfone(PES) support. The degree of crosslinking and thickness of PVA coating layer were analyzed by swelling test and SEM(scanning electron microscopy), respectively. Pervaporation test was done with two feed mixures; TFEA/water, MA/water. The pervaporation data were obtained as a function of content of crosslinking agent, feed composition, and operating temperature, respectively. In case of TFEA-water(90/10 wt%) feed mixture at $80^{\circ}C$, the optimized membrane showed the high permeation flux of 1.5 $kg/m^2hr$ and separation factor of 320. In case of MA-water(90/10 wt%) feed mixture, the membranealso showed high permeation flux of 2.3 $kg/m^2hr$ and separation factor of 740 in same conditions.

  • PDF

A Three-step Method of Immunotoxicity Assessment

  • Lee, Jeong-Woon;Shin, Ki-Duk;Kim, Kap-Ho;Kim, Eun-Joo;Han, Sang-Seop;Jeong, Tae-Cheon;Koh, Woo-Suk
    • Toxicological Research
    • /
    • v.16 no.4
    • /
    • pp.317-323
    • /
    • 2000
  • The immunosuppressive effects of thirty nine chemicals chosen by their potential toxicity were evaluated using a three-step testing method. The immunotoxicity test method developed in this study consisted of three simple assays of lymphoproliferation, mixed leukocyte response, and interleukin (IL)-2 production. The first step was mitogen-induced proliferation assay. Ten chemicals showed the inhibitory effects on the mitogen (lipopolysaccharide or concanavalin A)-induced proliferation in dose-dependent manners. The second step was mixed lymphocyte response. This step crosschecked the growth-suppressive effects detected at the first step. All of 10 chemicals, which showed suppression of lymphoproliferation, also exhibited the suppressive effects on the mixed lymphocyte response in the similar range of chemical concentration. The third step was planned to determine whether or not this growth suppression was mediated through an early activation of T-cell, which could be represented with IL-2 production. Six out of 10 chemicals decreased the interleukin-2 production in the similar concentration range used in the step 1 and 2. These results suggest that those 6 chemicals might have their targets on the signal transduction path-way toward the IL-2 production. In the meantime the other 4 chemicals might have their targets after the IL-2 production signal. Taken all together, the three-step test would be simple, fast, and efficient to deter-mine whether or not the chemical has immunosuppressive effects.

  • PDF

Chemical Resistance and Field Trial of 3D-Printed Plastic Ball Bearing Used in Electric Motors for Chemical Processes (화학공정용 전동기에 사용된 3D 프린팅 플라스틱 볼베어링의 내화학성 평가 및 현장적용 연구)

  • Youngjun Kwon;Myounggyu Noh
    • Tribology and Lubricants
    • /
    • v.39 no.1
    • /
    • pp.1-7
    • /
    • 2023
  • Fluid pumps in chemical processes are typically driven by electric motors. Even if the motor is separated from the pump with seals, wear resulting from friction and misalignment can lead to leakage of chemical fluid, causing corrosion in the bearing supporting the motor, and, eventually, failure of the motor. It is thus a standard procedure to replace bearings at regular intervals. In this article, we propose 3D-printed plastic ball bearings for use as an alternative to commercial stainless-steel ball bearings. The plastic bearings are easy to manufacture, require less time to replace, and are chemically resistant. To validate the applicability of the plastic bearings, we first conducted chemical resistance tests. Bearings were immersed in 30 caustic acid and 30 nitric acid for 30 min and 24 h, respectively. The test results showed no corrosive damage to the bearings. A test rig was set up to compare the performance of the plastic bearings with that of the commercially equivalent deep-groove ball bearings. Loading test results showed that the plastic bearings performed as well as the commercial bearing in terms of vibration level and load-handling capability. Finally, a plastic bearing was subjected to a clean-in-place process for three months. It actually outperformed the commercial bearing in terms of chemical resistance. Thus, 3D-printed plastic bearings are a viable alternative to stainless-steel ball bearings.

Consequence Analysis and Risk Reduction Methods for Propulsion Test Facility (추진시험설비의 사고피해영향분석 및 리스크 감소방안)

  • Shin, Ahn-Tae;Byun, Hun-Soo
    • Korean Chemical Engineering Research
    • /
    • v.54 no.3
    • /
    • pp.360-366
    • /
    • 2016
  • The Propulsion Test Facilities for the development of Korea Space Launch Vehicle-II are being built, some test facilities are completed and various combustion tests are running. The Propulsion Test Facilities consists test-stand, which carries out tests for engine development model, and various sub-systems and vessels containing LOX and Jet A-1 as propellant. There are always risks of fire and explosion at the test-stand since engine development model is conducted at test-stand with real combustion test with very high pressure, mixed propellant and high energy. In this paper, in order to establish the consequence analysis and risk reduction measures in the Propulsion Test Facilities, followings are considered. 1) a propellant leak accident scenario is assumed in test-stand. 2) TNT equivalent model equation based on blast wave of the explosion was used to analyze blast overpressure and impacts. Also, technical, systematic and managemental measure is described to ensure risk reduction for propulsion test facility.

Selection of coagulant using jar test and analytic hierarchy process: A case study of Mazandaran textile wastewater

  • Asadollahfardi, Gholamreza;Zangooei, Hossein;Motamedi, Vahid;Davoodi, Mostafa
    • Advances in environmental research
    • /
    • v.7 no.1
    • /
    • pp.1-11
    • /
    • 2018
  • Textile factories are one of the industries which its wastewater treatment is a challenging issue, especially in developing countries and a conventional treatment cannot treat all its pollutants properly. Using chemical coagulants is a technique for physical and chemical primary treatment of the wastewater. We applied jar test for selection of suitable coagulant among the five coagulants including alum, calcium hydroxide, ferrous sulfate, ferrous chloride and barium chloride for the effluent of wastewater in Mazandran textile factory located in Mazandran Province, Iran. In addition, jar test, we also used analytic hierarchy process (AHP) method considering criteria which included coagulation cost, sensitivity to pH change, the amount of sludge generation and side effects for coagulation. The results of the jar test indicated that calcium hydroxide was proper among the coagulants which it removed 92.9% total suspended solid (TSS), 70% dye and 30% chemical oxygen demand. The AHP analysis presented that calcium hydroxide is more suitable than other coagulants considering five criteria.

Accelerated Heat Aging Test for Predicting Useful Lifetime of Elastomeric Rearing (가속 열 노화시험에 의한 탄성받침용 합성고무의 수명 예측에 관한 연구)

  • Park, K.H.;Park, J.H.;Lee, H.H.;Kwon, Y.I.
    • Journal of Applied Reliability
    • /
    • v.4 no.2
    • /
    • pp.73-90
    • /
    • 2004
  • We performed the heat aging test to predict the useful lifetime of Elastomeric Bearing Chloroprene Rubber (CR) used for supporting bridge. During the test, we measured elongation that are influenced by temperature and aging time. The failure of a test piece is defined as the point at which the elongation reaches to 75% of the initial value. This failure criterion is based on KS F 4420: 1998 (Elastomeric Bearing for bridge). Through the accelerated heat aging test, we found that the Arrhenius relationship and the Weibull lifetime distribution are appropriate as the life-temperature relationship and lifetime distribution of the CR, respectively. Using the Arrhenius -Weibull model, the parameters of the model are estimated and the lifetime of the CR at use condition is predicted.

  • PDF

Feasibility of On-chip Detection of Endotoxin by LAL Test

  • Lee, Eun-Kyu;Suh, Chang-Woo;Hwang, Sang-Youn;Park, Hyo-Jin;Seong, Gi-Hoon;Ahn, Yoo-Min;Kim, Yang-Sun
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.9 no.2
    • /
    • pp.132-136
    • /
    • 2004
  • The LAL (Limulus amebocyte lysate) test for the detection and quantification of endotoxin is based on the gelation reaction between endotoxin and LAL from a blood extract of Limulus polyphemus. The test is labor intensive, requiring dedicated personnel, a relatively long reaction time (approximately 1 h), relatively large volumes of samples and reagents and the detection of the end-point is rather subjective. To solve these problems, a miniaturized LOC (lab-on-a-chip) prototype, 62mm (L) ${\times}$ 18 mm (W), was fabricated using PDMS (polydimethylsiloxane) bonded to glass. Using this prototype, in which 2mm (W) ${\times}$ 44.3mm (L) ${\times}$ 100 $\mu\textrm{m}$ (D) microfluidic channel was constructed, turbidometric and chromogenic assay detection methods were compared, and the chromogenic method was found the most suitable for a small volume assay. In this assay, the kinetic-point method was more accurate than the end-point method. The PDMS chip thickness was found to be minimized to around 2 mm to allow sufficient light transmittance, which necessitated the use of a glass slide bonding for chip rigidity. Due to this miniaturization, the test time was reduced from 1 h to less than 10 min, and the sample volume could be reduced from 100 to ca. 4.4 ${\mu}$L. In summation, this study suggested that the LOC using the LAL test principle could be an alternative as a semi-automated and reliable method for the detection of endotoxin.

Analysis Study on 32nd OPCW Proficiency Test Sample with GC-TSQ CI (GC-TSQ CI 분석법을 이용한 제32차 OPCW 숙련도 시험 시료 분석 연구)

  • Kim, Hyunsuk;Jung, Changhee;Lee, Yonghan
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.17 no.6
    • /
    • pp.828-835
    • /
    • 2014
  • GC-TSQ CI technique was applied for analysis of samples for the $32^{nd}$ OPCW proficiency test. Eight chemical weapon convention(CWC) related chemicals were identified by product ion mode analysis with GC-TSQ in the samples. Choice of specific precursor ion made it possible to supply selective total ion chromatograms(TICs) of target molecule. GC-TSQ CI anaylsis technique was useful method for chemical warfare agent verification because analysis selectivity was improved by choice of mother molecule as precursor ion and gave mass spectra.

A Clinical Study of the Effects of Chungganhaeju-tang on Alcoholic Fatty Liver (청간해주탕이 알코올성 지방간에 미치는 영향에 대한 임상적 연구)

  • 이장훈;박신명;김영철;우흥정
    • The Journal of Korean Medicine
    • /
    • v.22 no.4
    • /
    • pp.107-113
    • /
    • 2001
  • Objectives : The aim of this study was to investigate effects of Chungganhaeju-tang on alcoholic fatty liver. Methods : Thirty patients with alcoholic fatty liver were included in this study. Chungganhaeju-tang was administered to subjects for 1 month. The changes of clinical symptoms and chemical liver function tests were evaluated before and after treatment. Results : Chungganhaeju-tang has effects on the improvement of clinical symptoms such as fatigue, anorexia, dyspepsia, nausea, and RUQ (Right Upper Quadrant) pain. On the chemical liver function test, serum AST, ALT, GGT, and TG level significantly decreased (P<0.05, by paired t-test). Conclusions : These results suggest that Chungganhaeju-tang has significant effects on the improvement of clinical symptoms and chemical liver function test with alcoholic fatty liver.

  • PDF