388 research outputs found
Degree of approximation of Conjugate Series of a Fourier Series by (E,r)(N,p,q) Means
In this paper a theorem on degree of approximation of a function f Lip ? by product Summability(E,r)(N,p,q)of conjugate series of Fourier series associated with f, has been established
Synthesis And Characterization of Cationic Lipids And Carbon Nanomaterials Based Composites for the Delivery Of Bioactive Oligo/Polynucleotides and Drugs In Vitro and In Vivo
The biggest hurdle in success of gene and drug therapy is designing and preparation of suitable bio-nanomaterials to carry the desired nucleic acid and drug to the targeted site. The work described in the present thesis encompasses two different approaches for the delivery of bioactive oligo/polynucleotides and drugs in vitro and in vivo using either cationic lipids or their nanocomposites with different carbon nanomaterials. The idea of using carriers for oligo/polynucleotides and drugs came into existence because of numerous physiological barriers in pathway of delivery of naked oligo/polynucleotides or drugs which reduces the overall activity of these bioactives in biological systems. These barriers trigger scientific research toward the preparation of appropriate biomaterials which can overcome the physiological barriers and improve the activity of bioactive oligo/polynucleotides and drugs in cellular systems. Toward this end, the design and synthesis of different cationic lipids and carbon nanomaterials were undertaken as described in seven chapters of the thesis.
A series of novel cationic lipids with structural variability was prepared and used for gene delivery in vitro. They were further tuned chemically to sustain delivery efficiency in high serum percentage during in vitro transfection. These serum compatible lipids were used to perform transfection of reporter gene plasmid and found to be more efficient compared to the some well known commercial products for the same purpose.
Another series of novel lipids were synthesized for the targeted gene delivery in vitro. These tryptophan based cholesteryl lipids were used to prepare mixed liposomes. These mixed liposomes were highly efficient in targeting sigma receptor rich HEK293T over sigma receptor negative HeLa cells. Mixed liposomes were also prepared for selective targeting of αvβ3 and αvβ5 integrins in gene transfection protocol using a palmitoyl-RAFT-RGD4 template.
A mixed liposomal formulation was developed to carry out anti-sense siRNA mediated knockdown of Smad-2 protein with better efficiency compared to some of the best known commercial products for the same purpose. These mixed liposomes were also highly efficient for regression via induction of p53 mediated apoptosis in xenograft tumors developed in nude mice.
Carbon nanomaterials have been extensively explored as nanoscale gene/drug carriers for potential applications. But the challenge is to solubilize these highly hydrophobic materials in aqueous medium for use in biological systems. Although there are reports for covalent modifications of such nanomaterials but it could be done only with the loss of some beneficial features of these materials. Herein a non-covalent technique has been efficiently used to suspend single walled carbon nanotubes in water using biocompatible cationic lipids. These nanosuspensions were used to complex plasmid DNA and transfect them in vitro. They proved to be highly serum compatible DNA carriers which did not drop the efficiency even in very high percentage of serum. Similarly exfoliated graphene was modified with cationic lipid and serum components to improve IC50 of Tamoxifen citrate and Methotrexate to a considerable extent in vitro. The improved Methotrexate formulations were highly efficient for regression in size of xenograft tumors developed in nude mice.
Thus, the present thesis entails generation of cationic lipids and carbon nanomaterials based nanocomposites which were not only highly biocompatible themselves but their efficiency was found many fold better compare to some of the best commercial delivery agents. These were useful for the delivery of various bioactive oligo/polynucleotides and drugs in vitro and in vivo
A Hierarchical Framework of Challenges for Blockchain Adoption in Public Services. Implications for decision-makers
This study attempts to identify critical challenges for blockchain adoption in government, particularly public-service delivery in India, a developing country context. Through an extensive literature review and focus-group discussions with policymakers and blockchain experts, we have identified 12 adoption challenges for Blockchain in public service delivery. We then collected data and analysed using interpretive structural modeling and Cross-Impact Matrix Multiplication Applied to Classification (MICMAC) Analysis to develop a hierarchical framework of the challenges. Our findings indicate that governments must first ensure legislative support for blockchain-based transactions. This research contributes to information systems strategic planning literature and provides a framework for policymakers to craft a strategic approach to facilitate blockchain adoption
AstroSat-CZTI detection of variable prompt emission polarization in GRB 171010A
We present spectro-polarimetric analysis of \thisgrb\ using data from \asat,
\fermi, and \swift, to provide insights into the physical mechanisms of the
prompt radiation and the jet geometry.
Prompt emission from \thisgrb\ was very bright (fluence
~ergs~cm) and had a complex structure composed of the
superimposition of several pulses. The energy spectra deviate from the typical
Band function to show a low energy peak ~keV --- which we interpret as
a power-law with two breaks, with a synchrotron origin. Alternately, the prompt
spectra can also be interpreted as Comptonized emission, or a blackbody
combined with a Band function. Time-resolved analysis confirms the presence of
the low energy component, while the peak energy is found to be confined in the
range of 100--200~keV.
Afterglow emission detected by \fermi-LAT is typical of an external shock
model, and we constrain the initial Lorentz factor using the peak time of the
emission. \swift-XRT measurements of the afterglow show an indication for a jet
break, allowing us to constrain the jet opening angle to 6\degr.
Detection of a large number of Compton scattered events by \asat-CZTI
provides an opportunity to study hard X-ray polarization of the prompt
emission. We find that the burst has high, time-variable polarization, with the
emission {\bf have higher polarization} at energies above the peak energy.
We discuss all observations in the context of GRB models and polarization
arising due to {\bf due to physical or geometric effects:} synchrotron emission
from multiple shocks with ordered or random magnetic fields, Poynting flux
dominated jet undergoing abrupt magnetic dissipation, sub-photospheric
dissipation, a jet consisting of fragmented fireballs, and the Comptonization
model.Comment: Accepted for publication in Ap
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