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71.
Ameena Parveen Raghunandan Dashpande Shakeel Ahmed Aashis S. Roy 《Chemical Papers》2013,67(3):350-356
The polyaniline-PbO composites of various mass fractions were prepared by in situ polymerisation. The prepared samples were characterised by FTIR, and the dominant peaks confirmed the formation of polyaniline-PbO composites. The SEM study shows a granular agglomerated morphology, and increases with an increase in the lead oxide mass % in polyaniline. Direct current (DC) conductivity (σ DC) was studied as a function of temperature (T). From these studies, it was found that conductivity increased at higher temperatures due to the polarons hopping from one localised state to another. DSC studies reveal, the decrease in peak temperature from 273°C (pure PANI) to 169.2°C, 193.5°C, 218.4°C, 235.2°C, and 224.2°C, respectively for the various mass fractions (10 %, 30 %, 20 %, 40 %, and 50 %) of polyaniline-PbO composites. 相似文献
72.
The metal coordination complex K4[Fe(CN)6] is an efficient and environmentally benign catalyst for the synthesis of imidazolines and benzimidazoles from various aldehydes and 1,2‐diamines in aqueous medium at room temperature. This protocol gives excellent yield of product with desired purity. 相似文献
73.
Some theorems for the null conguences within the framework of general theory of relativity are given. These theorems are important in themselves as they illustrate the geometric meaning of the spin coefficients. The newly developed Geroch-Held-Penrose (GHP) formalism has been used throughout the investigations. The salient features of GHP formalism that are necessary for the present work are given, and these techniques are applied to a pair of null congruences C (l) and C(n). 相似文献
74.
Kabir-ud-Din Nahid Parveen Andleeb Z. Naqvi 《Journal of Dispersion Science and Technology》2013,34(10):1500-1505
It is well known that, like surfactants aggregating at a certain concentration (called critical micelle concentration, CMC), hydrotropes also have minimum hydrotrope concentration (MHC). However, unlike surfactant CMC, this MHC value is usually very high, thereby reducing their application. In this paper we report the results of conductivity and viscosity measurements with a well known hydrotrope sodium salicylate (NaSal) solutions in presence and absence of additives (propanol, PrOH; butanol, BuOH; pentanol, PeOH and tetrabutylammonium bromide, Bu4NBr). We have found that MHC value of NaSal decreases in presence of additives. Alcohols increase the hydrophobic interactions and decrease the MHC while Bu4NBr, in addition to ameliorating the hydrophobic interactions, reduces the charge on head groups and MHC decreases more steeply in its presence. Increased solubility of riboflavin in NaSal containing the above additives corroborates the results. 相似文献
75.
Farzana Miah Hendrik Koliwer-Brandl Martin Rejzek Robert A. Field Rainer Kalscheuer Stephen Bornemann 《Chemistry & biology》2013,20(4):487-493
Highlights? Flux through trehalose synthase (TreS) in mycobacteria is from trehalose to maltose ? The appropriate α anomer is formed by TreS for maltose kinase of the GlgE pathway ? The specificity of TreS for α-maltose is retained with deoxyfluoro analogs ? TreS supports cytosolic/capsular α-glucan but not trehalose mycolate biosynthesis 相似文献
76.
Farzana Hossain Shruthi Kandalai Xiaozhuang Zhou Nan Zhang Qingfei Zheng 《Molecules (Basel, Switzerland)》2022,27(20)
Cancer vaccines have been considered promising therapeutic strategies and are often constructed from whole cells, attenuated pathogens, carbohydrates, peptides, nucleic acids, etc. However, the use of whole organisms or pathogens can elicit unwanted immune responses arising from unforeseen reactions to the vaccine components. On the other hand, synthetic vaccines, which contain antigens that are conjugated, often with carrier proteins, can overcome these issues. Therefore, in this review we have highlighted the synthetic approaches and discussed several bioconjugation strategies for developing antigen-based cancer vaccines. In addition, the major synthetic biology approaches that were used to develop genetically modified cancer vaccines and their progress in clinical research are summarized here. Furthermore, to boost the immune responses of any vaccines, the addition of suitable adjuvants and a proper delivery system are essential. Hence, this review also mentions the synthesis of adjuvants and utilization of biomaterial scaffolds, which may facilitate the design of future cancer vaccines. 相似文献
77.
Mohammad Sarwar Shahnaz Parveen Hamdani Iftikhar Ahmad R. J. Thibert 《Mikrochimica acta》1971,59(4):573-576
Summary A rapid, convenient and accurate method for the determination of xanthates has been developed. N-bromosuccinimide has been used to displace iodine from potassium iodide which in turn oxidizes xanthate to dixanthogen. The pH 4 is optimum for the determination. The maximum relative standard deviation is 6% in the case of ethyl potassium xanthate when a 0.5 mg sample was taken.
Zusammenfassung Ein genaues Verfahren zur raschen Bestimmung von Xanthat wurde entwickelt. N-Bromsuccinimid dient zur Freisetzung von Jod aus KJ; Jod oxydiert Xanthat zu Dixanthogen. Das optimale pH für die Bestimmung ist 4. Die größte relative Standardabweichung ist 6% bei einer Einwaage von 0,5 mg Kaliumäthylxanthat.相似文献
78.
Emmanuel T. Oluwabusola Nursheena Parveen Katermeran Wee Han Poh Teo Min Ben Goh Lik Tong Tan Oluwatofunmilayo Diyaolu Jioji Tabudravu Rainer Ebel Scott A. Rice Marcel Jaspars 《Molecules (Basel, Switzerland)》2022,27(5)
Natural products derived from marine sponges have exhibited bioactivity and, in some cases, serve as potent quorum sensing inhibitory agents that prevent biofilm formation and attenuate virulence factor expression by pathogenic microorganisms. In this study, the inhibitory activity of the psammaplin-type compounds, psammaplin A (1) and bisaprasin (2), isolated from the marine sponge, Aplysinella rhax, are evaluated in quorum sensing inhibitory assays based on the Pseudomonas aeruginosa PAO1 lasB-gfp(ASV) and rhlA-gfp(ASV) biosensor strains. The results indicate that psammaplin A (1) showed moderate inhibition on lasB-gfp expression, but significantly inhibited the QS-gene promoter, rhlA-gfp, with IC50 values at 14.02 μM and 4.99 μM, respectively. In contrast, bisaprasin (2) displayed significant florescence inhibition in both biosensors, PAO1 lasB-gfp and rhlA-gfp, with IC50 values at 3.53 μM and 2.41 μM, respectively. Preliminary analysis suggested the importance of the bromotyrosine and oxime functionalities for QSI activity in these molecules. In addition, psammaplin A and bisaprasin downregulated elastase expression as determined by the standard enzymatic elastase assay, although greater reduction in elastase production was observed with 1 at 50 μM and 100 μM. Furthermore, the study revealed that bisaprasin (2) reduced biofilm formation in P. aeruginosa. 相似文献
79.
Xiaoqing Zhang Yesim Gozukara Parveen Sangwan Dachao Gao Stuart Bateman 《Polymer Degradation and Stability》2010,95(12):2309-2317
Biodegradation of a series of chemically modified thermally processed wheat gluten (WG)-based natural polymers were examined according to Australian Standard (AS ISO 14855). Most of these materials reached 93-100% biodegradation within 22 days of composting, and the growth of fungi and significant phase deformation were observed during the process. Chemical crosslinking did slow down the rate or reduce the degree of the biodegradation with different behaviours for different modified systems. The segments containing structures derived from the reactions with additives such as tannin or epoxidised soybean oil remained in the degradation residues while the glycidoxypropyl trimethoxysilane agent produced ∼20% un-degraded residues containing silicon-crosslinking structures. The biodegradation rate of each component of the materials was also different with the protein and starch components degraded fast but lipid degraded relatively slowly. 相似文献
80.
Choudhari Dinkar Chakravarty Debamitra Lande Dipali N. Parveen Sana Gejji Shridhar P. Kodam Kisan M. Salunke-Gawali Sunita 《Structural chemistry》2019,30(6):2257-2270
Structural Chemistry - Homologated (N)-n-alkylammonium salts of 2-bromo-3-oxido-1,4-naphthoquinone (BS-1 to BS-8) have been synthesized and characterized from the single crystal X-ray diffraction... 相似文献