979 research outputs found
Role of mashups, social networking platforms and semantic in revolutionizing web integration: Key insights and enterprise implications
The article examines the emergence and role of mashups in integrating data across the web, how social networking platforms penetrated the web by adding social experiences and how they helped in web integration, while solving some of the issues of mashups. We also discuss how semantic markups evolved in parallel, trying to bring in structured data and why social networking platforms need semantics for building the social graph of users. We take the case of Facebook‟s Open Graph protocol and discuss how semantic markups enhanced web integration by simplifying the process of creating mashups, giving more personalized experiences to the users. Finally, we present an integrated view of the role of mashups, social networking platforms and semantics from the angle of web integration and the insights that enterprises can learn from them
DNA-amine interactions: from monolayers to nanoparticles
DNA is a polyanionic molecule that can electrostatically interact with positively charged ligands. Interaction with surfactants such as CTAB leads to cooperative binding of detergent molecules through synergistic effects of electrostatic and hydrophobic forces. DNA can also form a monolayer at air-water interface with positively charged octylamine and nanoparticles with cationic lysine capped gold nanoparticles. Formation of such electrostatic composites of DNA has practical implications for developing DNA diagnostic systems and for lipidencapsulated DNA delivery systems
Quantum dimer model on fullerenes: resonance, scarring and confinement
The earliest known examples of quantum superposition were found in organic
chemistry -- in molecules that `resonate' among multiple arrangements of
-bonds. Small molecules such as benzene resonate among a few bond
arrangements. In contrast, a large system that stretches over a macroscopic
lattice may resonate among an extensive number of configurations. This is
analogous to a quantum spin liquid as described by Anderson's resonating
valence bond (RVB) picture. In this article, we study the intermediate case of
somewhat large molecules, the C and C fullerenes. We build a
minimal description in terms of quantum dimer models, allowing for local
resonance processes and repulsion between proximate -bonds. This allows us
to characterize ground-states, e.g., with C forming a superposition of
5828 dimer covers. Despite the large number of contributing dimer covers, the
ground state shows strong dimer-dimer correlations. Going beyond the ground
state, the full spectrum of C shows many interesting features. Its
Hilbert space is bipartite, leading to spectral reflection symmetry. It has a
large number of protected zero-energy states. In addition, the spectrum
contains many scar-like states, corresponding to localized
dimer-rearrangement-dynamics. Resonance dynamics in QDMs can manifest in the
behaviour of defects, potentially binding defects via an effective attractive
interaction. To test this notion, we introduce pairs of vacancies at all
possible separations. Resonance energy reaches its lowest value when the
vacancies are closest to one another. This suggests confinement of monomers,
albeit within a finite cluster. We discuss qualitative pictures for
understanding bonding in fullerenes and draw connections with results from
quantum chemistry.Comment: 9 pages, 8 figure
PNA C-C<SUP>+</SUP> i-motif: superior stability of PNA TC<SUB>8</SUB> tetraplexes compared to DNA TC<SUB>8</SUB> tetraplexes at low pH
Study of self-assembly of PNA TC8 monitored by UV thermal transition at 295 nm indicates formation of a C-C+ tetraplex (i-motif) in acidic pH, with higher stability than the analogous dTC8
Expanding the repertoire of pyrrolidyl PNA analogues for DNA/RNA hybridization selectivity: aminoethylpyrrolidinone PNA (aepone-PNA)
New PNA analogues derived from aminoethylpyrrolidin- 5-one backbone show stabilization of aepone-PNA:DNA hybrids and destabilization of the corresponding RNA hybrids compared to unmodified PNA
Fluorescent d (CGCGAATTCGCG): characterization of major groove polarity and study of minor groove interactions through a major groove semantophore conjugate
The major and minor groove in duplex DNA are sites of specific molecular recognition by DNA-binding agents such as proteins, drugs and metal complexes and have functional significance. In view of this, understanding of the inherent differences in their environment and the allosteric information transfer between them induced by DNA-binding agents assumes importance. Site-specific incorporation of 5-aminodansyl-dU, (U) in oligonucleotides d(CGCGAAUTCGCG) and d(CGCGAATUCGCG) leads to fluorogenic nucleic acids, in which the reporter group resides in the major groove. The fluorescent observables from such a probe are used to estimate the dielectric constant of the major groove to be -55D, in comparison to the reported non polar environment of the minor groove (-20D) in poly d[AT]-poly d[AT]. An exclusive minor groove event such as DNA-netropsin association can be quantitatively monitored by fluorescence of the dansyl moiety located in the major groove. This suggests existence of an information network among the two grooves. The fluorescent DNA probes as reported here may have potential applications in the study of structural polymorphisms in DNA, DNA ligand interactions and triple helix structure
(α,α-dimethyl)glycyl (dmg) PNAs: Achiral PNA analogs that form stronger hybrids with cDNA relative to isosequential RNA
The design and facile synthesis of sterically constrained new analogs of PNA having gem-dimethyl substitutions on glycine (dmg-PNA-T) is presented. The PNA oligomers [aminoethyl dimethylglycyl (aedmg) and aminopropyl dimethylglycyl (apdmg)] synthesized from the monomers 6 and 12) effected remarkable stabilization of homothyminePNA2:homoadenine DNA/RNA triplexes and mixed base sequence duplexes with target cDNA or RNA. They show a higher binding to DNA relative to that with isosequential RNA. This may be a structural consequence of the sterically rigid gem-dimethyl group, imposing a pre-organized conformation favorable for complex formation with cDNA. The results complement our previous work that had demonstrated that cyclohexanyl-PNAs favor binding with cRNA compared with cDNA and imply that the biophysical and structural properties of PNAs can be directed by introduction of the right rigidity in PNA backbone devoid of chirality. This approach of tweaking selectivity in binding of PNA constructs by installing gem-dimethyl substitution in PNA backbone can be extended to further fine-tuning by similar substitution in the aminoethyl segment as well either individually or in conjunction with present substitution
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