排序方式: 共有127条查询结果,搜索用时 31 毫秒
71.
This paper describes elastic properties and spectroscopic studies on the xPbO-50B2O3-(50 - x)V2O5 (where x = 20, 25, 30, 35, 40, 45 and 49 mol%) glass system. Elastic moduli and spectroscopic parameters exhibit compositional dependent trends and the existence of characteristic borovanadate groups in these glasses. The bulk modulus and shear modulus increase with the concentration of [BO4/2]− and [B2V2O9]2− groups, which increases the dimensionality of the network. The scheme of modification of borate and vanadate groups has been explained by considering the Sanderson’s electronegativity principle. Analysis of infrared(IR) and magic angle spinning-nuclear magnetic resonance (MAS-NMR) spectra suggests the presence of characteristic diborovanadate groups also in these glasses. The results are examined in view of the structural groups formed due to the presence of PbO as a modifier. 相似文献
72.
73.
Berelli Anupama Airva Aruna Vijjulatha Manga Sreekanth Sivan Madamsetty Vijay Sagar Ravula Chandrashekar 《Journal of fluorescence》2017,27(3):953-965
Ternary Cu(II) complexes [Cu(II)(L)(bpy)Cl] 1, [Cu(II)(L)(Phen)Cl] 2 [L = 2,3–dimethyl-1-phenyl-4(2 hydroxy-5-methyl benzylideneamino)-pyrazol-5-one, bpy = 2,2′ bipyridine, phen =1,10 phenanthroline) were synthesized and characterized by elemental analyses, UV-Visible, FT-IR, ESR, Mass, thermogravimetric and SEM EDAX techniques. The complexes exhibit octahedral geometry. The interaction of the Cu(II) with cailf thymus DNA (CT-DNA) was explored by using absorption and fluorescence spectroscopic methods. The results revealed that the complexes have an affinity constant for DNA in the order of 104 M?1 and mode of interaction is intercalative mode. The DNA cleavage study showed that the complexes cleaved DNA without any external agent. The interaction of Cu(II) complexes with bovine serum albumin (BSA) was also studied using absorption and fluorescence techniques. The cytotoxic activity of the Cu(II) complexes was probed in HeLa (human breast adenocarcinoma cell line), B16F10 (Murine melanoma cell line) and HEPA1–6 celllines, complex 1 has good cytotoxic activity which is comparable with the doxarubicin drug, with IC50 values ranging from 3 to 12.6 μM. A further molecular docking technique was employed to understand the binding of the complexes towards the molecular target DNA. Investigation of the antioxidative properties showed that the metal complexes have significant radical scavenging activity potency against DPPH radical. 相似文献
74.
Suresh Maddila Ramakanth Pagadala Sreekanth B. Jonnalagadda 《Journal of heterocyclic chemistry》2015,52(2):487-491
A new series of 4‐(4‐substitutedbenzylideneamino)‐5‐((1‐methyl‐1H‐tetrazol‐5‐ylthio)methyl)‐4H‐1,2,4‐triazole‐3‐thiol derivatives ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k ) are prepared using 4‐amino‐5‐((1‐methyl‐1H‐tetrazol‐5‐ylthio)methyl‐4H‐1,2,4‐triazole‐3‐thiol ( 4 ), as an intermediate compound. The structures of all the newly synthesized products are established supported by their spectral 1H NMR, 13C NMR, FTIR, electrospray ionization mass spectrometry (mass), and analytical data. All the compounds are screened for their insecticidal activity against Plodia interpunctella, and six compounds exhibited significant activity. 相似文献
75.
The synthesis of enantiopure 2-C-methyl-d-erythritol-4-phosphate is disclosed. A 1,3-diol possessing a quaternary stereogenic centre, prepared stereoselectively from an acyclic tri-substituted alkene, has been utilized as a key intermediate. 相似文献
76.
Supramolecular synthon polymorphism in 2 : 1 co-crystal of 4-hydroxybenzoic acid and 2,3,5,6-tetramethylpyrazine 总被引:1,自引:0,他引:1
Co-crystals of 4-hydroxybenzoic acid and 2,3,5,6-tetramethylpyrazine (2 : 1) exhibit the first supramolecular synthon polymorphism in a co-crystal; metastable anti-hierarchic polymorph I converts to stable hierarchic form II. 相似文献
77.
Zymography is a powerful technique to separate and identify different enzymatic activities on a standard acrylamide gel. For oxidation prone enzymes such as cysteine proteases however, the oxidizing species generated by electrolysis of the gel running buffer may result in partial or complete inactivation, thus compromising the final readout. This can be only partially remedied by subsequent treatment of the gel with reducing agents. We demonstrate the generation of reactive oxidizing species during electrophoresis and discovered that supplementation of the gel running buffer with a minimum of 5 mM cysteine prevents enzyme inactivation and allows retention of proteolytic activity as measured by zymography on model substrate N α‐benzoyl‐l ‐arginine p‐nitroanilide, without at the same time altering the mobilities of the gel proteins. 相似文献
78.
Sridevi Gorle Suresh Maddila Santosh Chokkakula Palakondu Lavanya Moganavelli Singh Sreekanth B. Jonnalagadda 《Journal of heterocyclic chemistry》2016,53(6):1852-1858
A new series of 5‐fluoro‐N4‐(3‐(4‐substitutedbenzylamino)phenyl)‐N2‐(4‐morpholinophenyl)pyrimidine‐2,4‐diamine derivatives ( 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j ) are prepared from using an intermediate compound 5‐fluoro‐N4‐(3‐(aminophenyl)‐N2‐(4‐morpholinophenyl)pyrimidine‐2,4‐diamine ( 5 ). The structures of the newly synthesized products are established from their spectral 1H‐NMR, 13C‐NMR, 19F‐NMR, ESI‐MS, and analytical data. Here we report the synthesized compounds and larvicidal activity. All the compounds are screened for their significant larvicidal activity against third instar larvae at 24, 48, and 78‐h time exposure, and values were compared with standard drug Malathion. The Compounds 7i , 7a , 7c , 7f , and 7j exhibited significant activity. However the compounds 7b , 7e , 7d , and 7h showed excellent activity when compared to the above compounds and to standard drug malathion too because of the presence of mild electron withdrawing groups such as trifluoro, fluorine, hydroxy, nitro, and methoxy derivatives which are attached to the benzyl ring. 相似文献
79.
80.
A sensitive, selective and rapid LC–ESI–MS/MS method has been developed and validated for the quantification of copanlisib in mouse plasma using enasidenib as an internal standard (IS) as per regulatory guideline. Copanlisib and the IS were extracted from mouse plasma using ethyl acetate as an extraction solvent and chromatographed using an isocratic mobile phase (0.2% formic acid–acetonitrile; 25:75, v/v) on a HyPURITY C18 column. Copanlisib and the IS eluted at ~0.95 and 2.00 min, respectively. The MS/MS ion transitions monitored were m/z 481.1 → 360.1 and m/z 474.0 → 456.0 for copanlisib and the IS, respectively. The calibration range was 3.59–3588 ng/mL. The intra‐ and inter‐batch accuracy and precision (RE and RSD) across quality controls met the acceptance criteria. Stability studies showed that copanlisib was stable in mouse plasma for one month. This novel method has been applied to a pharmacokinetic study in mice. 相似文献