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排序方式: 共有248条查询结果,搜索用时 31 毫秒
121.
Mehtap Tugrak Halise Inci Gul Hiroshi Sakagami Ilhami Gulcin 《Journal of heterocyclic chemistry》2020,57(7):2762-2768
2-(3-[4-Methoxyphenyl]-5-aryl-4,5-dihydro-1H-pyrazol-1-yl)benzo[d]thiazoles ( 1b-7b ) were synthesized for the first time except 1b , and spectral methods such as 1H NMR, 13C NMR and HRMS were utilized to illuminate the chemical structures of the synthesized compounds. Phenyl ( 1b ), 2-methoxyphenyl ( 2b ), 4-methoxyphenyl ( 3b ), 4-methoxy-3-hydroxyphenyl ( 4b ), 2,5-dimethoxyphenyl ( 5b ), 3,4,5-trimethoxyphenyl ( 6b ), or thiophene-2-yl ( 7b ) was used as a aryl part. The inhibitory effects of the compounds were evaluated toward human carbonic anhydrase I and II enzymes (hCA I and hCA II). In vitro cytotoxic effects of the compounds against human oral squamous carcinomas and human normal oral cells were carried out via MTT. The compounds ( 1b-7b ) had Ki values of 36.87 ± 11.62-66.24 ± 2.99 μM (hCA I) and 22.66 ± 1.41-89.95 ± 6.25 μM (hCA II). Compounds 1b (Ki = 36.87 ± 11.62 μM) toward hCA I, 6b (Ki = 22.66 ± 1.41 μM) toward hCA II had significant enzyme inhibitory potency. Compound 6b had the highest tumor selectivity (TS = 29.3) and potency selectivity expression (PSE = 272.3) values. Therefore, compounds 1b and 6b with CAs inhibition effect and compound 6b with the cytotoxicity may be forwarded to further studies as potent compounds. 相似文献
122.
The mathematical modeling of a planar solid‐liquid interface in the solidification of a dilute binary alloy is formulating by one of nonintegrable, nonlinear evolution equation known as Sivashinsky equation. In the first part of this paper, the mathematical modeling of Sivashinsky equation is briefly discussed. Since, the exact solutions of this equation is yet unknown, obtaining its numerical solution plays an important role to simulate its behavior. Therefore, in the second part, a second‐order splitting finite difference scheme, based on Crank‐Nicolson method, is investigated to approximate the solution of the Sivashinsky equation with homogeneous boundary conditions. We prove the solvability of the present scheme and establish the error estimate of the numerical scheme. 相似文献
123.
Statistical copolymers of perfluoroalkyl ethyl methacrylate (Zonyl-TM) and methylmethacrylate were synthesized in CO2-expanded monomer mixture at a low pressure of 10–13 MPa for the first time. M w of the copolymers was found to decrease with the increase of Zonyl-TM content. Flat films of these copolymers were obtained by dip coating from their chloroform solutions and were characterized using contact angle measurements, optical microscopy, and 3D profilometry. The increase in the Zonyl-TM content of the copolymers resulted in a decrease of the total surface free energy. Superhydrophobic and oleophobic rough copolymer films were also prepared by applying a phase-separation process where THF was used as the solvent and ethanol as the non-solvent. Surface roughness increased with the increase in the nonsolvent ratio resulting in an increase in the water contact angle from 103° to 151° and hexadecane contact angle from 49° to 73°. 相似文献
124.
T. Ünak U. Avcibaşi Y. Yildirim 《Journal of Radioanalytical and Nuclear Chemistry》2005,266(3):503-506
Summary Phenolphthalein-glucuronide is a commonly used glucuronide conjugate for beta-glucuronidase measurements. The quantity of
phenolphthalein liberated by beta-glucuronidase is measured spectrophotometrically. The detection limit of the quantity of
phenolphthalein using spectrophotometry is a few μg. In this study, a new radioanalytical technique for the measurement of
beta-glucuronidase was applied which is 106times more sensitive than the spectrophotometric technique. Radioiodinated phenolphthalein-glucuronide and phenyl-N-glucuronide
were used in this study in which the beta-glucuronidase levels of some tissue samples were measured. 相似文献
125.
Poly(methyl methacrylate-ran-perfluoroalkyl ethyl methacrylate) copolymers having varying perfluoroalkyl ethyl methacrylate ester (Zonyl-TM) contents were synthesized in supercritical CO2. Complete amorphous structures of the copolymers were verified by XRD. Young's modulus (Ymod) of the copolymers was decreased linearly from 1.57 to 1.08 GPa and Tg values from 102 to 77 °C with the increase of Zonyl-TM content. A linear relationship between the Ymod and the Tg values of the copolymer was also found. The increase of the large branched pendant groups resulted in the increase of the free volume and a corresponding decrease in Ymod and Tg of the copolymers. A good fit was found when the Schneider equation was used. Negative deviation from the Gordon-Taylor equation was observed when Zonyl-TM content was lower than 14% due to rapid increase in free volume and then a positive deviation was found due to the dipole-dipole interactions between the methyl ester and fluoroalkyl ester groups. 相似文献
126.
127.
Brad Traeger Sanjay S. Srivatsa Kevin M. Beussman Yechun Wang Yildirim B. Suzen Frank J. Rybicki Wojciech Mazur Tomasz Miszalski-Jamka 《Theoretical and Computational Fluid Dynamics》2016,30(1-2):107-128
Aortic stenosis is the most common valvular heart disease. Assessing the contribution of the valve as a portion to total ventricular load is essential for the aging population. A CT scan for one patient was used to create one in vivo tricuspid aortic valve geometry and assessed with computational fluid dynamics (CFD). CFD simulated the pressure, velocity, and flow rate, which were used to assess the Gorlin formula and continuity equation, current clinical diagnostic standards. The results demonstrate an underestimation of the anatomic orifice area (AOA) by Gorlin formula and overestimation of AOA by the continuity equation, using peak velocities, as would be measured clinically by Doppler echocardiography. As a result, we suggest that the Gorlin formula is unable to achieve the intended estimation of AOA and largely underestimates AOA at the critical low-flow states present in heart failure. The disparity in the use of echocardiography with the continuity equation is due to the variation in velocity profile between the outflow tract and the valve orifice. Comparison of time-averaged orifice areas by Gorlin and continuity with instantaneous orifice areas by planimetry can mask the errors of these methods, which is a result of the assumption that the blood flow is inviscid. 相似文献
128.
Filiz Ertu?ral Ekber Guliyev Ali Kuliev Zemine Yildirim 《Central European Journal of Physics》2009,7(4):731-737
In this study, the result of calculations using rotational, translational and Galilean invariant quasiparticle random-phase
approximation is presented for the low-lying dipole excitations in the even-even 160Gd nucleus. Calculations are carried out for both ΔK=1 and ΔK=0 branches. The analysis shows that the main part of spin-1 states, observed at energy 2.4–4 MeV in 160Gd, have M1 character and are interpreted as main fragments of the scissors mode. The calculations indicate the presence of
a few prominent negativeparity dipole ΔK=1 states in the investigated energy region, in agreement with experiment.
相似文献
129.
Lithium triborate (LBO) is a newly developed ideal nonlinear optical (NLO) crystal used in laser weapon, welder, radar, tracker, surgery, communication, etc. The effective atomic number (Zeff=7.3) makes it a tissue equivalent material and this encourages studies on its thermoluminescence (TL) properties for a radiation dosimetry. The previous studies have shown that Al-doped LiB3O5 is a promising thermoluminescent dosimetric (TLD) material for dosimetric purposes and continuous and systematic investigations to improve its quality to get ones suited for dosimeter applications are worthy. In the given study, the additive dose (AD), initial rise with partial cleaning (IR), variable heating rate (VHR), peak shape (PS), three-points method (TPM) and computerized glow deconvolution (CGCD) methods were used to determine the kinetic parameters, namely the order of kinetics (b), activation energy (Ea) and the frequency factor (s) associated with the dosimetric thermoluminescent glow peak (P3) of Al-doped LiB3O5 after different dose levels with β-irradiation. 相似文献
130.
Kim JH Ji S Lee SH Lake B Yildirim T Nojiri H Kikuchi H Habicht K Qiu Y Kiefer K 《Physical review letters》2008,101(10):107201
We report bulk magnetization, and elastic and inelastic neutron scattering measurements under an external magnetic field H on the weakly coupled distorted kagome system, Cu2(OD)3Cl. Our results show that the ordered state below 6.7 K is a canted antiferromagnet and consists of large antiferromagnetic ac components and smaller ferromagnetic b components. By first-principles calculations and linear spin wave analysis, we present a simple spin Hamiltonian with nonuniform nearest neighbor exchange interactions resulting in a system of coupled spin trimers with a single-ion anisotropy that can qualitatively reproduce the spin dynamics of Cu2(OD)3Cl. 相似文献