12 research outputs found
MORE ON INTERVAL-VALUED INTUITIONISTIC FUZZY SOFT MULTI SETS
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 Morganās 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
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
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 āmeltedā 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
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 Xāray Fluorescence Spectrometry
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,
liquidāliquid 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 0.1ā1000 ng mL<sup>ā1</sup> and 0.02 ng mL<sup>ā1</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 (1Ļ)
Designed Tetrapeptide Interacts with Tubulin and Microtubule
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 āanchor
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
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 āanchor
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
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
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) Ć 10<sup>ā3</sup> min<sup>ā1</sup> and
(16.9 Ā± 0.6) Ć 10<sup>ā3</sup> min<sup>ā1</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)
Ć 10<sup>ā2</sup> min<sup>ā1</sup> and (12.6 Ā±
2.5) Ć 10<sup>ā2</sup> min<sup>ā1</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
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