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11.
Fatima Gul Naz Paliwal Sarvesh K. Saraf Shailendra K. 《Russian Journal of General Chemistry》2021,91(2):285-293
Russian Journal of General Chemistry - A number of novel 7-chloro-4-aminoquinoline derivatives have been efficiently synthesized by nucleophilic aromatic substitution reaction of... 相似文献
12.
J. M. Martínez J. I. Eguiazábal J. Nazábal 《Journal of Macromolecular Science: Physics》2013,52(4):345-355
The mechanical properties of miscible poly(butylene terephthalate) (PBT)/poly (hydroxy ether of bisphenol A) (phenoxy) blends obtained by melt mixing have been studied by means of the tensile test. The crystallinity of the blends has been studied by means of DSC and density measurements. A synergistic behavior, principally in the break properties, at high PBT contents in the blends is observed. As can be seen from the torque and density data, this synergistic behavior is related with the high level of miscibility which seems to exist at high PBT contents compared with that of the high phenoxy content region. 相似文献
13.
Urea dimethacrylates functionalized with bisphosphonate/bisphosphonic acid for improved dental materials 下载免费PDF全文
Melek Naz Guven Ece Akyol Fatma Demir Duman Havva Yagci Acar Ozlem Karahan Duygu Avci 《Journal of polymer science. Part A, Polymer chemistry》2017,55(19):3195-3204
Incorporation of bisphosphonate/bisphosphonic acid groups in dental monomer structures should increase interaction of these monomers with dental tissue as these groups have strong affinity for hydroxyapatite. Therefore, new urea dimethacrylates functionalized with bisphosphonate (1a, 1b) and bisphosphonic acid (2a, 2b) groups are synthesized and evaluated for dental applications. Monomers 1a and 1b are synthesized from 2‐isocyanatoethyl methacrylate (IEM) and two bisphosphonated amines (BPA1 and BPA2), prepared as reported elsewhere. Selective dealkylation of the bisphosphonate ester groups of 1a and 1b using trimethylsilyl bromide (TMSBr) gives monomers (2a and 2b) with bisphosphonic acid functionality. X‐ray diffractometer (XRD), Raman spectroscopy, and X‐ray photoelectron spectroscopy (XPS) analyses of monomer‐treated HAP particles show that 2a induces formation of stable monomer‐calcium salts, similar to 10‐methacryloyloxydecyl dihydrogen phosphate (MDP), with higher chemical interaction than 2b. The photopolymerization studies indicate good copolymerizability with commercial dental monomers. In vitro studies on NIH 3T3 mouse embryonic fibroblast cells have clearly shown that the tested monomers (1b and 2b) are not toxic according to the MTT standards. All these properties make these monomers suitable as biocompatible cross‐linkers/adhesives for dental applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3195–3204 相似文献
14.
Shaheen Faizi Humaira Siddiqi Aneela Naz Samina Bano Lubna 《Helvetica chimica acta》2010,93(3):466-481
An H/D exchange process in patuletin ( 1 ) and its derivatives in D‐donor solvents (e.g., CF3COOD), which occurs regioselectively at C(8) was observed for the first time during NMR studies. The effect of substituents and temperature on the deuteration of various flavonoids (see Fig. 1) which include apigenin, chrysin, galangin, kaempferol, luteolin, morin, myricetin, patuletin, patulitrin, and quercetin, as well as derivatives of patuletin was examined extensively under NMR conditions. The rate constant of deuteration at C(8) of patuletin ( 1 ) and two flavones, luteolin ( 3 ) and apigenin ( 12 ), was also determined in CF3COOD. The D‐atom was introduced into the flavonoids via a keto–enol tautomerism (Scheme 1). During these studies, monodeuterated patuletin was also obtained as a new compound. The examined flavonoids have been reported to possess significant pharmacological activities, and their deuterated derivatives would be of importance for the identification and quantification of these compounds in biological matrices. 相似文献
15.
Roheena Abdullah Kinza Nisar Aafia Aslam Mehwish Iqtedar Shagufta Naz 《Natural product research》2015,29(11):1006-1011
This study is related to the isolation of fungal strain for xylanase production using agro-industrial residues. Forty fungal strains with xylanolytic potential were isolated by using xylan agar plates and quantitatively screened in solid-state fermentation. Of all the tested isolates, the strain showing highest ability to produce xylanase was assigned the code Aspergillus niger LCBT-14. For the enhanced production of the enzyme, five different fermentation media were evaluated. Out of all media, M4 containing wheat bran gave maximum enzyme production. Effect of different variables including incubation time, temperature, pH, carbon and nitrogen sources has been investigated. The optimum enzyme production was obtained after 72 h at 30°C and pH 4. Glucose as a carbon source while ammonium sulphate and yeast extract as nitrogen sources gave maximum xylanase production (946 U/mL/min). This study was successful in producing xylanase by A. niger LCBT-14 economically by utilising cheap indigenous substrate. 相似文献
16.
Mehwish Iqtedar Mohammad Nadeem Hira Naeem Roheena Abdullah Shagufta Naz Qurat ul Ain Syed 《Natural product research》2015,29(11):1012-1019
The industrialisation of lignocellulose conversion is impeded by expensive cellulase enzymes required for saccharification in bioethanol production. Current research undertakes cellulase production from pretreated Saccharum spontaneum through Trichoderma viride HN1 under submerged fermentation conditions. Pretreatment of substrate with 2% NaOH resulted in 88% delignification. Maximum cellulase production (2603 ± 16.39 U/mL/min carboxymethyl cellulase and 1393 ± 25.55 U/mL/min FPase) was achieved at 6% substrate at pH 5.0, with 5% inoculum, incubated at 35°C for 120 h of fermentation period. Addition of surfactant, Tween 80 and metal ion Mn+2, significantly enhanced cellulase yield. This study accounts proficient cellulase yield through process optimisation by exploiting cheaper substrate to escalate their commercial endeavour. 相似文献
17.
Effects of porous medium have been investigated on the steady flow of a third grade fluid between two stationary porous plates. The continuity and momentum equations along with modified Darcy??s law are used for the development of mathematical problem. The governing nonlinear problem is solved by a homotopy analysis method. The dimensionless velocity and shear stresses at the plates are analyzed. 相似文献
18.
Naz Mohammed Aghatabay Yaghub Mahmiani Hüseyin Çevik Fahrettin Gucin Basaran Dulger 《Structural chemistry》2008,19(5):833-842
Series of new mixed aza-oxo-thia macrocyclic ligands {2,6,12,16-tetraaza-1,7,11,17-tetraoxo-9,19-dithia-[(4′-methyl-5′,4,3′)(14′-methyl-15′,14,13′)]ditriazine}cyclocosane
(L
1
); {2,6,13,17-teraaza-1,7,12,18-tetraoxo-9,10,20,21-tetrathia-[(4′-methyl-5′,4,3′)(15′-methyl-14′,16′,15)]di-triazine}cyclodocosane
(L
2
); {2,6,14,18-tetraaza-1,7,13,19-tetraoxo-10,22-dithia-[(4′-methyl-5′,3′,4)(16′-methyl-15′,17′,16)]ditriazine}cyclotetracosane
(L
3
) and {2,6,15,19-tetraaza-1,7,14,12-tetraoxo-10,11,23,24-tetrathia-[(4′-methyl-5′,4,3′)(17′-methyl-8′,17,16′)]ditriazine}cyclohexa-cosane
(L
4
) were synthesized. The structural features of the compounds have been studied by elemental analyses, Mass, FT-Raman, FT-IR,
1H and 13C NMR spectroscopy. The antimicrobial activities of the ligands were evaluated using disk diffusion method in dimethyl sulfoxide
as well as the minimal inhibitory concentration (MIC) dilution method, against 9 bacteria. The obtained results from disk
diffusion method were assessed in side-by-side comparison with those of Penicillin-g, Ampicillin, Cefotaxime, Vancomycin,
Oflaxacin, and Tetracyclin, well-known antibacterial agents. The results from dilution procedure were compared with Gentamycin
as antibacterial and Nystatin as antifungal. The antifungal activities are reported on five yeast cultures namely Candida albicans, Kluyveromyces fragilis, Rhodotorula rubra, Debaryomyces hansenii, and Hanseniaspora guilliermondii, and the results are referenced with Nystatin, Ketaconazole, and Clotrimazole, commercial antifungal agents. In most cases,
the compounds show strong antifungal activity in the comparison tests. 相似文献
19.
Shan N Ingram JD Easun TL Vickers SJ Adams H Ward MD Thomas JA 《Dalton transactions (Cambridge, England : 2003)》2006,(23):2900-2906
Using a [Ru(II)([9]aneS3)] templating moiety, kinetically-locked, metallomacrocycles incorporating adenine based ligands have been synthesised through self-assembly. The kinetically robust nature of these structures is confirmed by electrochemical studies: each can be reversibly oxidised in a four-member redox series, containing two formally mixed valence states. Unusually, the electrochemically derived comproportionation constants for these mixed valence states are very different, suggesting that intermetallic coupling differs between the two states. Spectroelectochemistry studies confirm that while the [Ru(II)2Ru(III)] state is valence localised, the [Ru(II)Ru(III)2] state is electronically delocalised. Mechanisms by which this switching effect could occur, which involve the unusual connectivities in these mixed valence species, are presented. 相似文献
20.