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21.
Vural E. Kafadar 《Physica B: Condensed Matter》2011,406(3):537-540
The dosimetric characteristics of many TL materials are influenced by changes in location, size and shape of the glow curves due to changes in the heating rate. In this study, the effect of heating rate on the integrated peak areas of CaF2:Dy (TLD-200), CaF2:Tm (TLD-300) and CaF2:Mn (TLD-400) crystals have been investigated after β-irradiation. It was observed that the peak temperatures of all peaks shifted to the high temperature sides and the integrated peak areas decrease as the heating rate increases due to thermal quenching, whose efficiency increases as temperature increases. 相似文献
22.
Michelyne Haroun Santosh S. Chobe Rajasekhar Reddy Alavala Savita M. Mathure Risy Namratha Jamullamudi Charushila K. Nerkar Vijay Kumar Gugulothu Christophe Tratrat Mohammed Monirul Islam Katharigatta N. Venugopala Mohammed Habeebuddin Mallikarjun Telsang Nagaraja Sreeharsha Md. Khalid Anwer 《Molecules (Basel, Switzerland)》2022,27(12)
Considering the importance of benzothiazepine pharmacophore, an attempt was carried out to synthesize novel 1,5-benzothiazepine derivatives using polyethylene glycol-400 (PEG-400)-mediated pathways. Initially, different chalcones were synthesized and then subjected to a cyclization step with benzothiazepine in the presence of bleaching clay and PEG-400. PEG-400-mediated synthesis resulted in a yield of more than 95% in less than an hour of reaction time. Synthesized compounds 2a–2j were investigated for their in vitro cytotoxic activity. Moreover, the same compounds were subjected to systematic in silico screening for the identification of target proteins such as human adenosine kinase, glycogen synthase kinase-3β, and human mitogen-activated protein kinase 1. The compounds showed promising results in cytotoxicity assays; among the tested compounds, 2c showed the most potent cytotoxic activity in the liver cancer cell line Hep G-2, with an IC50 of 3.29 ± 0.15 µM, whereas the standard drug IC50 was 4.68 ± 0.17 µM. In the prostate cancer cell line DU-145, the compounds displayed IC50 ranges of 15.42 ± 0.16 to 41.34 ± 0.12 µM, while the standard drug had an IC50 of 21.96 ± 0.15 µM. In terms of structural insights, the halogenated phenyl substitution on the second position of benzothiazepine was found to significantly improve the biological activity. This characteristic feature is supported by the binding patterns on the selected target proteins in docking simulations. In this study, 1,5-benzothiazepines have been identified as potential anticancer agents which can be further exploited for the development of more potent derivatives. 相似文献
23.
The convergences of three L1 spline methods for scattered data interpolation and fitting using bivariate spline spaces are studied in this paper. That is, L1 interpolatory splines, splines of least absolute deviation, and L1 smoothing splines are shown to converge to the given data function under some conditions and hence, the surfaces from these three methods will resemble the given data values. 相似文献
24.
《Analytical letters》2012,45(7):1279-1289
Abstract Based on the fact that nonionic surfactant polyethylene glycol-400 (PEG-400) catalyzed the chemiluminescence of luminol-H2O2 system, a novel and simple chemiluminescence method has been developed for the determination of PEG-400. Under the optimal conditions, the standard curve was Y = 198835X–2091.8, where the correlation coefficient (R) was 0.9999. The detection limit was 4 × 10?5 g·ml?1 PEG-400 and the linear range was 1.0 × 10?4–4.0 × 10?2g·ml?1. The relative standard deviation was 3.2% at 2.0 × 10?3 g·ml?1 PEG-400 (n = 7). This method has been applied to the determination of PEG-400 in cosmetic samples with satisfactory results. Furthermore, the dynamics characteristic curve of PEG-400 in luminol-H2O2 system was compared to typical metallic ion and other surfactants. Moreover, the mechanism of the luminol-H2O2-PEG-400 chemiluminescence system was studied, assisted by fluorescence spectra and UV spectra. 相似文献
25.
《Green Chemistry Letters and Reviews》2013,6(1):73-78
Abstract An efficient synthesis of 3-amino 1H-pyrazoles is described. The reaction of β-keto nitriles with hydrazines in the presence of a catalytic amount of p-toluene sulphonic acid using polyethylene glycol-400 as an efficient and recyclable reaction medium afforded the corresponding 3-amino 1H pyrazoles excellent yields. 相似文献
26.
An expeditious synthesis of 2-aryl-benzimidazoles by the condensation of o-phenylenediamine with various araldehydes is described. This greener protocol is catalyzed by Amberlite IR-120, and proceeds efficiently in the absence of any organic solvent under microwave irradiation within 3–5 min. 相似文献
27.
《Analytical letters》2012,45(13):2089-2101
Abstract A procedure for the spectrophotometric determination of aluminum traces in water using a flow injection (FI) preconcentration system has been proposed. The flow system was made up of a peristaltic pump, an injector‐commutator, and a minicolumn filled with 300.0 mg of Amberlite IR‐120 cationic exchange resin. After the preconcentration step, aluminum was eluted by a 4.0 mol l?1 HCl solution. In a second stage, out of the flow system, the eluate was neutralized with a 4.0 mol l?1 NaOH solution. The aluminum was submitted to the reaction with eriochrome cyanine to form a chelate in solution buffered to pH 5.85, according to the Standard Method's procedure with some modifications, and this was followed by spectrophotometric detection. Chemical and flow variables were studied in the preconcentration system. The precision of the proposed method was calculated for a solution containing 46.8 µg l?1 of Al(III), when 40.0 ml of solution were preconcentrated (n=7), and their respective relative standard deviation (RSD) was 1.8%. The detection limit obtained was 1.7 µg l?1 of Al(III) (sample volume=40.0 ml). The proposed method was successful in determining aluminum in water certified reference material. 相似文献
28.
S.P. Avdeyev V.A. Karnaukhov W.D. Kuznetsov L.A. Petrov V.K. Rodionov A.S. Zubkevich H. Oeschler O.V. Bochkarev L.V. Chulkov E.A. Kuzmin A. Budzanovski W. Karcz M. Janicki E. Norbeck A.S. Botvina W.A. Friedman W. Nörenberg G. Papp 《The European Physical Journal A - Hadrons and Nuclei》1998,3(1):75-83
Multiple emission of intermediate-mass fragments has been studied for the collisions p + Au at 2.16, 3.6 and 8.1 GeV with
the FASA setup. The mean IMF multiplicities for events with at least one IMF are equal to 1.7, 1.9 and 2.1 (±0.2) respectively.
The multiplicity, charge distributions and kinetic energy spectra of IMF are described in the framework of a intranuclear
cascade model followed by the statistical multifragmentation model. However, between the two parts of the calculation the
excitation energies and the residual masses and charges are modified to take into account the losses during expansion. The
results support a scenario of true thermal multifragmentation of a hot and expanded target spectator.
Received: 15 December 1997 / Revised version: 24 April 1998 相似文献
29.
A simple and efficient protocol for CuI‐catalyzed C? S bond formation of aryl halides with KSCN to symmetrical diaryl sulfides was reported in PEG‐400 without any other additives. A variety of aryl halides were converted to the corresponding diaryl sulfides in good to excellent yields. The present procedure tolerated a variety of functional groups and the steric hindrance of ortho‐substituents on aryl halides did not affect the outcome. 相似文献
30.
Summary Hydroxypropyl methyl cellulose (HPMC) and polyethylene glycol 400 (PEG 400) content in HypoTears™ Daily Dose ophthalmic solution
are determined simultaneously by size exclusion chromatography. The retention times of HPMC and PEG 400 are 10.6 and 15.4
minutes, respectively. The method requires minimal sample pretreatment and is accurate and reproducible. The peak area response
from a refractive index detector versus HPMC and PEG 400 concentration is linear over the range of 50–150 % of their label
claims of 2.5 mg/mL and 10 mg/mL, respectively. The mean absolute recoveries of HPMC and PEG 400 at their label claim using
the described method are 98.9±1.3 % and 100.4±1.2 % (mean±SD, n=12), respectively. 相似文献