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New aqueous cationomeric polyurethane dispersions (PUDs) were synthesized by three step reaction process. Isophorone diisocyanate (IPDI) was reacted with polyols, namely, polypropylene glycol-400, polypropylene glycol-1000 and polypropylene glycol-2000, to form prepolymers which were chain extended by reacting it with N-methyldiethanolamine (N-MDEA). Quarternization and self-emulsification with deionized water resulted in PUDs. The resultant cationomers were film casted and characterized by FT-IR, DSC, TGA, DMTA and SEM analyses. Further, for the first time in the literature, aqueous cationomeric polyurethane dispersions (PUDs) were used for blending with 2 wt%, 4 wt% and 6 wt% of polyaniline–DBSA water dispersions to form new conductive composites. The conductivity attained is in the range 1.2 × 10−5–3.7 × 10−5 S/cm. These composites were evaluated for their corrosion protection abilities on mild steel panels by standard accelerated tests. 相似文献
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Kosbe Pradnya Patil Pradeep Manickam Muthukumar Ramamurthy Gurunathan 《Journal of Mechanical Science and Technology》2020,34(4):1495-1502
Journal of Mechanical Science and Technology - In earlier friction composites, higher thermal conductive copper and copper-based alloys were the main functional fillers to regulate stable friction... 相似文献
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Xi-Feng Zhang Qi Yan Wei Shen Sangiliyandi Gurunathan 《International journal of molecular sciences》2016,17(8)
Cervical cancer ranks seventh overall among all types of cancer in women. Although several treatments, including radiation, surgery and chemotherapy, are available to eradicate or reduce the size of cancer, many cancers eventually relapse. Thus, it is essential to identify possible alternative therapeutic approaches for cancer. We sought to identify alternative and effective therapeutic approaches, by first synthesizing palladium nanoparticles (PdNPs), using a novel biomolecule called saponin. The synthesized PdNPs were characterized by several analytical techniques. They were significantly spherical in shape, with an average size of 5 nm. Recently, PdNPs gained much interest in various therapies of cancer cells. Similarly, histone deacetylase inhibitors are known to play a vital role in anti-proliferative activity, gene expression, cell cycle arrest, differentiation and apoptosis in various cancer cells. Therefore, we selected trichostatin A (TSA) and PdNPs and studied their combined effect on apoptosis in cervical cancer cells. Cells treated with either TSA or PdNPs showed a dose-dependent effect on cell viability. The combinatorial effect, tested with 50 nM TSA and 50 nMPdNPs, had a more dramatic inhibitory effect on cell viability, than either TSA or PdNPs alone. The combination of TSA and PdNPs had a more pronounced effect on cytotoxicity, oxidative stress, mitochondrial membrane potential (MMP), caspase-3/9 activity and expression of pro- and anti-apoptotic genes. Our data show a strong synergistic interaction between TSA and PdNPs in cervical cancer cells. The combinatorial treatment increased the therapeutic potential and demonstrated relevant targeted therapy for cervical cancer. Furthermore, we provide the first evidence for the combinatory effect and cytotoxicity mechanism of TSA and PdNPs in cervical cancer cells. 相似文献
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Sangiliyandi Gurunathan Jae Woong Han Deug-Nam Kwon Jin-Hoi Kim 《Nanoscale research letters》2014,9(1):373
Silver nanoparticles (AgNPs) have been used as antibacterial, antifungal, antiviral, anti-inflammtory, and antiangiogenic due to its unique properties such as physical, chemical, and biological properties. The present study was aimed to investigate antibacterial and anti-biofilm activities of silver nanoparticles alone and in combination with conventional antibiotics against various human pathogenic bacteria. Here, we show that a simple, reliable, cost effective and green method for the synthesis of AgNPs by treating silver ions with leaf extract of Allophylus cobbe. The A. cobbe-mediated synthesis of AgNPs (AgNPs) was characterized by ultraviolet-visible absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Furthermore, the antibacterial and anti-biofilm activity of antibiotics or AgNPs, or combinations of AgNPs with an antibiotic was evaluated using a series of assays: such as in vitro killing assay, disc diffusion assay, biofilm inhibition, and reactive oxygen species generation in Pseudomonas aeruginosa, Shigella flexneri, Staphylococcus aureus, and Streptococcus pneumonia. The results suggest that, in combination with antibiotics, there were significant antimicrobial and anti-biofilm effects at lowest concentration of AgNPs using a novel plant extract of A. cobbe, otherwise sublethal concentrations of the antibiotics. The significant enhancing effects were observed for ampicillin and vancomycin against Gram-negative and Gram-positive bacteria, respectively. These data suggest that combining antibiotics and biogenic AgNPs can be used therapeutically for the treatment of infectious diseases caused by bacteria. This study presented evidence of antibacterial and anti-biofilm effects of A. cobbe-mediated synthesis of AgNPs and their enhanced capacity against various human pathogenic bacteria. These results suggest that AgNPs could be used as an adjuvant for the treatment of infectious diseases. 相似文献
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Sangiliyandi Gurunathan Jae Woong Han Ahmed Abdal Dayem Vasuki Eppakayala Mi-Ryung Park Deug-Nam Kwon Jin-Hoi Kim 《Journal of Industrial and Engineering Chemistry》2013,19(4):1280-1288
A green and simple approach is described for the large scale synthesis of reduced graphene oxide (rGO). The transition of graphene oxide (GO) into graphene was confirmed using various analytical techniques. Raman spectroscopy data indicate the partial removal of oxygen-containing functional groups from the surface of GO and formation of graphene. X-ray diffraction (XRD) was used to investigate the crystallinity of graphene nanosheets. The antibacterial activity of GO and rGO was evaluated using cell viability, reactive oxygen species (ROS) production and DNA fragmentation assays. The results suggest that GO and rGO possessed an excellent antimicrobial activity against Escherichia coli. 相似文献
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Enzymatic mitigation of acrylamide in fried potato chips using asparaginase from Aspergillus terreus 总被引:2,自引:0,他引:2 下载免费PDF全文
Ravi Aiswarya Gurunathan Baskar 《International Journal of Food Science & Technology》2018,53(2):491-498
Acrylamide in foods is declared as carcinogen. In the present work, the effect of enzymatic pretreatment and other parameters like enzyme concentration, frying conditions with respect to temperature and time, size of potato chips, and effect of sodium chloride and citric acid on mitigation of acrylamide were studied. The concentration of acrylamide in fried potatoes after the pretreatment was found to be 815.63 μg kg?1. The optimised asparaginase concentration for the mitigation of acrylamide was calibrated as 4 U mL?1, and optimised frying time and temperature were 15 min and 170 °C, respectively. An in‐depth kinetic relationship for the effect of asparaginase on the mitigation of acrylamide was studied. The prime novelty of the project is focused on the immobilisation of asparaginase to nanomagnetic particles for redundant usage with stabilised enzyme activity. The work projected three stables cycles of asparaginase activity and on further usage of the immobilised enzyme resulted in decreased activity. The repeated use of immobilised asparaginase provides the advantage of decreasing cost in processing. 相似文献
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Manisha Jain Mariya Sebatini Govindasamy Sharmila Chandrasekaran Muthukumaran Gurunathan Baskar Krishnamurthi Tamilarasan 《化学工程与技术》2015,38(8):1444-1451
The preparation of chitosan‐coated magnetic nanoparticles (MNPs) and covalent immobilization of α‐amylase for starch hydrolysis was investigated. Surface morphology, chemical composition, and structural characteristics of the MNPs were analyzed by scanning electron microscopy, energy dispersion spectrometry, and X‐ray diffractometry, respectively. Surface functional groups of MNPs, chitosan‐coated MNPs, and α‐amylase‐immobilized MNPs were characterized by Fourier transform infrared spectroscopy. Response surface methodology based on three levels was implemented to optimize three immobilization conditions and a regression model was developed. α‐Amylase‐immobilized MNPs provided better stability towards pH and temperature. The prepared thermostable nanobiocatalyst is well‐suited for industrial processes involving starch hydrolysis. 相似文献
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Hyperbranched Polymers for Coating Applications: A Review 总被引:1,自引:0,他引:1
T. Gurunathan Smita Mohanty Sanjay K. Nayak 《Polymer-Plastics Technology and Engineering》2016,55(1):92-117
In the present era, hyperbranched polymers have been received much progress in the structural understanding and their unique chemical and physical properties as well as their potential applications in coatings. In a new perspective, low Volatile Organic Compounds (VOC) coatings and films with previously nonachievable properties can now be produced due to the innovation of a new class of macromolecular architecture, called hyperbranched polymers revolution. This review describes notable efforts on the synthesis of hyperbranched polymers, characterization techniques, and some of the key approaches that have been made in the application of these hyperbranched polymers in the areas of PU coatings. 相似文献
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