12 research outputs found

    MORE ON INTERVAL-VALUED INTUITIONISTIC FUZZY SOFT MULTI SETS

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    In 2013, Mukherje et al. developed the concept of interval-valued intuitionistic fuzzy soft multi set as a mathematical tool for making descriptions of the objective world more realistic, practical and accurate in some cases, making it very promising. In this paper we define some operations in interval-valued intuitionistic fuzzy soft multi set theory and show that the associative, distribution and De Morganā€™s type of results hold in interval-valued intuitionistic fuzzy soft multi set theory for the newly defined operations in our way. Also, we define the necessity and possibility operations on interval-valued intuitionistic fuzzy soft multi set theory and study their basic properties and some results

    Diffusion of Polymers through Periodic Networks of Lipid-Based Nanochannels

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    We present an experimental investigation of the diffusion of unfolded polymers in the triply-periodic water-channel network of inverse bicontinuous cubic phases. Depending on the chain size, our results indicate the presence of two different dynamical regimes corresponding to Zimm and Rouse diffusion. We support our findings by scaling arguments based on a combination of blob and effective-medium theories and suggest the presence of a third regime where dynamics is driven by reptation. Our experimental results also show an increasing behavior of the partition coefficient as a function of the polymer molecular weight, indicative of a reduction in the conformational degrees of freedom induced by the confinement

    Catalytically Initiated Gel-in-Gel Printing of Composite Hydrogels

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    Herein, we describe a method to 3D print robust hydrogels and hydrogel composites via gel-in-gel 3D printing with catalytically activated polymerization to induce cross-linking. A polymerizable shear-thinning hydrogel ink with tetramethylethylenediamine as catalyst was directly extruded into a shear-thinning hydrogel support bath with ammonium persulfate as initiator in a pattern-wise manner. When the two gels came into contact, the free radicals generated by the catalyst initiated the free-radical polymerization of the hydrogel ink. Unlike photocuring, a catalyst-initiated polymerization is suitable for printing hydrogel composites of varying opacity, since it does not depend upon light penetration through the sample. The hydrogel support bath also exhibited a temperature-responsive behavior in which the gel ā€œmeltedā€ upon cooling below 16 Ā°C. Therefore, the printed object was easily removed by cooling the gel to a liquid state. Hydrogel composites with graphene oxide and multiwalled carbon nanotubes (MWCNTs) were successfully printed. The printed composites with MWCNTs afforded photothermally active objects, which have utility as stimuli-responsive actuators

    Synthesis of Excitation Independent Highly Luminescent Graphene Quantum Dots through Perchloric Acid Oxidation

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    We demonstrate a facile liquid phase exfoliation method by only using perchloric acid to synthesize graphene quantum dots (GQDs) having excitation independent strong emission with a quantum yield of about 14%. The proposed simplified synthesis strategy can help in overcoming the limitations of existing aqueous routes which produce GQDs with excitation dependent emission and of low quantum efficiency. Photoluminescence (PL) properties of GQDs have been studied in detail to understand the origin of emission. As-synthesized GQDs show excitation independent photoluminesce (PL) which suggests that the synthesized materials do not have any significant defects. Spectral analysis suggests that the PL emission of the well-defined GQDs originates mainly from the peripheral functional groups conjugated with carbon backbone planes. We also demonstrate a relatively longer PL lifetime (average lifetime of about 10 ns) of the synthesized GQDs determined by time correlated single photon counting (TCSPC) measurement and this high lifetime suggests that the synthesized GQDs may be suitable for biomacromolecular probing. In addition, as-synthesized GQDs interestingly show delayed fluorescence and steady state anisotropy, which make the material an appropriate candidate for application in sensing and bioimaging of cells and organisms

    Selective Micellar Extraction of Ultratrace Levels of Uranium in Aqueous Samples by Task Specific Ionic Liquid Followed by Its Detection Employing Total Reflection Xā€‘ray Fluorescence Spectrometry

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    A task specific ionic liquid (TSIL) bearing phosphoramidate group, viz., <i>N</i>-propylĀ­(diphenylphosphoramidate)Ā­trimethylammonium bisĀ­(trifluoromethanesulfonyl)Ā­imide, was synthesized and characterized by <sup>1</sup>H NMR, <sup>13</sup>C NMR, <sup>31</sup>P NMR, and IR spectroscopies, elemental (C H N S) analysis, and electrospray ionization mass spectrometry (ESI-MS). Using this TSIL a cloud point extraction (CPE) or micelle mediated extraction procedure was developed for preconcentration of uranium (U) in environmental aqueous samples. Total reflection X-ray fluorescence spectrometry was utilized to determine the concentration of U in the preconcentrated samples. In order to understand the mechanism of the CPE procedure, complexation study of the TSIL with U was carried out by isothermal calorimetric titration, liquidā€“liquid extraction, <sup>31</sup>P NMR and IR spectroscopies, and ESI-MS. The developed analytical technique resulted in quantitative extraction efficiency of 99.0 Ā± 0.5% and a preconcentration factor of 99 for U. The linear dynamic range and method detection limit of the procedure were found to be 0.1ā€“1000 ng mL<sup>ā€“1</sup> and 0.02 ng mL<sup>ā€“1</sup>, respectively. The CPE procedure was found to tolerate a higher concentration of commonly available interfering cations and anions, especially the lanthanides. The developed analytical method was validated by determining the concentration of U in a certified reference material, viz., NIST SRM 1640a natural water, which was found to be in good agreement at a 95% confidence limit with the certified value. The method was successfully applied to the U determination in three natural water samples with ā‰¤4% relative standard deviation (1Ļƒ)

    Designed Tetrapeptide Interacts with Tubulin and Microtubule

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    Microtubules regulate eukaryotic cell functions, which have tremendous implication in tumor progression. Thus, the design of novel approaches for controlling microtubule function is extremely important. In this manuscript, a novel tetrapeptide Ser-Leu-Arg-Pro (SLRP) has been designed and synthesized from a small peptide library consisting of 14 tetrapeptides, which perturbs microtubule function through interaction in the ā€œanchor regionā€. We have studied the role of peptides on microtubule function on a chemically functionalized 2D platform. Interestingly, we have found that SLRP binds with tubulin and inhibits the kinesin-driven microtubule motility on a kinesin-immobilized chemically functionalized 2D platform. Further, this peptide modulator interacts with intracellular tubulin/microtubule and depolymerizes the microtubule networks. These interesting findings of perturbation of microtubule function both on engineered platforms and inside the cell by this small peptide modulator inspired us to study the effect of this tetrapeptide on cancer cell proliferation. We found that the novel tetrapeptide modulator causes moderate cytotoxicity to the human breast cancer cell (MCF-7 cell), induces the apoptotic death of MCF-7 cell, and activates the tumor suppressor proteins p53 and cyclin-dependent kinase inhibitor 1 (p21). To the best of our knowledge, this is the shortest peptide discovered, which perturbs microtubule function both on an engineered 2D platform and inside the cell

    Designed Tetrapeptide Interacts with Tubulin and Microtubule

    No full text
    Microtubules regulate eukaryotic cell functions, which have tremendous implication in tumor progression. Thus, the design of novel approaches for controlling microtubule function is extremely important. In this manuscript, a novel tetrapeptide Ser-Leu-Arg-Pro (SLRP) has been designed and synthesized from a small peptide library consisting of 14 tetrapeptides, which perturbs microtubule function through interaction in the ā€œanchor regionā€. We have studied the role of peptides on microtubule function on a chemically functionalized 2D platform. Interestingly, we have found that SLRP binds with tubulin and inhibits the kinesin-driven microtubule motility on a kinesin-immobilized chemically functionalized 2D platform. Further, this peptide modulator interacts with intracellular tubulin/microtubule and depolymerizes the microtubule networks. These interesting findings of perturbation of microtubule function both on engineered platforms and inside the cell by this small peptide modulator inspired us to study the effect of this tetrapeptide on cancer cell proliferation. We found that the novel tetrapeptide modulator causes moderate cytotoxicity to the human breast cancer cell (MCF-7 cell), induces the apoptotic death of MCF-7 cell, and activates the tumor suppressor proteins p53 and cyclin-dependent kinase inhibitor 1 (p21). To the best of our knowledge, this is the shortest peptide discovered, which perturbs microtubule function both on an engineered 2D platform and inside the cell

    Apoferritin Nanocage Delivers Combination of Microtubule and Nucleus Targeting Anticancer Drugs

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    An ideal nano drug delivery agent must be potent enough to carry high dose of therapeutics and competent enough in targeting specific cell of interest, having adequate optimized physiochemical properties and biocompatibility. Carrying differentially polar therapeutics simultaneously will make them superior in their class. However, it is of enormous challenge to the researchers to find such a unique nanocarrier and to engineer all of the above-mentioned features into it. In this manuscript, we have shown for the first time that apoferritin (Apf) can carry and deliver high dose of doxorubicin (Dox), docetaxel (Doc), and combination of both Dox and Doc specifically into the cancer cell and enhances killing compared to free drug without any functionalization or property modulation. In addition, we have shown that Apf alone is noncytotoxic in nature and interacts with intracellular tubulin/microtubule. Drug loaded Apf specifically bound and consequently internalized into the human breast cancer cell line (MCF7) and human cervical cancer cell line (HeLa) through receptor mediated endocytosis process and releases either single or combination of drugs in the endosome. We have also checked the binding efficacy of both drugs using molecular docking. Further, using fluorescence microscopy, we have shown that Apf can deliver combination of drugs inside cancer cells and the drugs exerts their effect thereof. Finally, we have studied the efficacy of Apf complexes with individual drugs and in combination compared to free drugs in a tumor mimicking 3D multicellular spheroid model of HeLa cell

    Investigation into the Catalytic Activity of Porous Platinum Nanostructures

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    The catalytic activity of porous platinum nanostructures, viz. platinum nanonets (PtNNs) and platinum nanoballs (PtNBs), synthesized by radiolysis were studied using two model reactions (i) electron transfer reaction between hexacyanoferrate (III) and sodium thiosulfate and (ii) the reduction of <i>p</i>-nitrophenol by sodium borohydride to <i>p</i>-aminophenol. The kinetic investigations were carried out for the platinum nanostructure-catalyzed reactions at different temperatures. The pseudofirst-order rate constant for the electron transfer reaction between hexacyanoferrate (III) and sodium thiosulfate catalyzed by PtNNs and PtNBs at 293 K are (9.1 Ā± 0.7) Ɨ 10<sup>ā€“3</sup> min<sup>ā€“1</sup> and (16.9 Ā± 0.6) Ɨ 10<sup>ā€“3</sup> min<sup>ā€“1</sup>, respectively. For the PtNN- and PtNB-catalyzed reduction of <i>p</i>-nitrophenol to <i>p</i>-aminophenol by sodium borohydride, the pseudofirst-order rate constant was (8.4 Ā± 0.3) Ɨ 10<sup>ā€“2</sup> min<sup>ā€“1</sup> and (12.6 Ā± 2.5) Ɨ 10<sup>ā€“2</sup> min<sup>ā€“1</sup>, respectively. The accessible surface area of the PtNNs and PtNBs determined before the reaction are 99 and 110 m<sup>2</sup>/g, respectively. These nanostructures exhibit significantly higher catalytic activity, consistent with the largest accessible surface area reported so far for the solid platinum nanoparticles. The equilibrium of the reactants on the surface of the platinum nanostructures played an important role in the induction time (<i>t</i><sub>0</sub>) observed in the reaction. A possible role of structural modifications of PtNBs catalyzed the reaction leading to change in the accessible surface area of PtNBs is being explored to explain the nonlinear behavior in the kinetic curve. The activation energy of the PtNN- and PtNB-catalyzed reduction of <i>p</i>-nitrophenol are 26 and 6.4 kJ/mol, respectively. These observations open up new challenges in the field of material science to design and synthesize platinum nanostructures which could withstand such reaction conditions

    Spatial Position Regulates Power of Tryptophan: Discovery of a Major-Groove-Specific Nuclear-Localizing, Cell-Penetrating Tetrapeptide

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    Identification of key amino acids is required for development of efficient cell-penetrating peptides (CPPs) and has tremendous implications in medicine. Extensive research work has enlightened us about the importance of two amino acids, arginine and tryptophan, in cell penetration. Here, we present a top-down approach to show how spatial positions of two tryptophans regulate the cellular entry and nuclear localization. This enables us to develop short, non-toxic tetrapeptides with excellent potential for cell penetration and nuclear localization. Among them, Glu-Thr-Trp-Trp (ETWW) emerges as the most promising. Results suggest that it enters into cancer cells following an endocytic pathway and binds at the major groove of nuclear DNA, where successive tryptophan plays major role. We subsequently show that it is not a P-glycoprotein substrate and is non-toxic to PC12-derived neurons, suggesting its excellent potential as a CPP. Furthermore, its potential as a CPP is validated in multi-cellular 3D cell culture (spheroid) and in <i>in vivo</i> mice model. This study provides major fundamental insights about the positional importance of tryptophan and opens new avenues toward the development of next-generation CPPs and major-groove-specific anticancer drugs
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