(1) However, at a 50-fold higher strand concentration, the single-stranded oligomer is gradually converted into the quadruplex.
(2) We propose a model in which duplex or hairpin forms of G-DNA are folding intermediates in the formation of either 1-, 2-, or 4-stranded quadruplex structures.
(3) There has been much recent interest in the self-association of short deoxyguanosine-rich motifs within single-stranded DNAs to generate monovalent cation modulated four-stranded helical segments called G-quadruplexes stabilized by hydrogen-bonded G-tetrad alignments.
(4) Thus the number of T residues surrounding the dG cluster might control the rigidity of the quadruplex structure.
(5) Equilibrium ultracentrifugation studies confirm that these quadruplexes are composed of two strands of d(G3T4G3).
(6) The only precedent known (to us) for a cation-specific stabilization is that seen in the quadruplex structure formed by poly I.
(7) The quadruplex, [d(TTGGGGTT)]4, is resistant to denaturation in 7 M urea, in which the Watson-Crick type d(TTGGGGTT).d(AACCCCAA) duplex dissociates.
(8) We observe well-resolved proton NMR spectra corresponding to a G-quadruplex monomer conformation predominant at 50 mM K cation concentration and a G-quadruplex dimer conformation predominant at 300 mM K cation concentration.
(9) Our results indicate that specific differences in ionic interactions can result in a switch in telomeric DNAs between intramolecular hairpin-like or quadruplex-containing species and intermolecular quadruplex structures, all of which involve G.G base pairing interactions.
(10) The possible biological function of quadruplexes is discussed.
(11) The DNA oligonucleotide d(CGCG3GCG) can form either a Watson-Crick (WC) hairpin or a parallel-stranded quadruplex structure containing six G-quartet base pair assemblies.
(12) We find that these molecules fold to form a symmetrical bimolecular and an intramolecular quadruplex, respectively.
(13) An increase in ionic strength stabilizes the single-stranded structure, so it seems to inhibit the formation of the quadruplex.
(14) Experiments on ethidium bromide binding to the oligonucleotides have shown that the oligomer anti(A-T) exists, at a low ionic strength, as a four stranded complex ("quadruplex") contains two antiparallel helices, d(A).d(T), which have a parallel orientation and are bound to one another owing to the formation of additional hydrogen bonds between nucleic acid bases.
(15) The quadruplex is stable in the presence of 40 mM K+ at micromolar DNA concentration and can be kinetically trapped as a metastable form when prepared at millimolar DNA concentration and then diluted into buffer containing 40 mM Na+.
(16) Cations stabilize the quadruplex in the order K+ greater than Ca2+ greater than Na+ greater than Mg2+ greater than Li+ and K+ greater than Rb+ greater than Cs+, indicating that K+ has an optimum ionic radius for complex formation and that ionic charge affects the extent of ion-induced stabilization.
(17) Comparison with the corresponding CD spectral characteristics suggests that the electrophoretic intensity enhancement of the intermolecular G-quadruplex band is correlated to the intensity enhancement of of the positive CD maximum at 265 nm.
(18) Similar but less dramatic enhancement of the intermolecular quadruplex band is also observed in T4.
(19) Since K+ and NH4+ are known to stabilize a parallel-stranded quadruplex structure of poly[r(I)4], we infer that the multistranded structure is a quadruplex.
(20) UV thermal denaturation curves show a single concentration-dependent transition and provide data for quantitating the thermodynamics of quadruplex formation.
Wire
Definition:
(n.) A thread or slender rod of metal; a metallic substance formed to an even thread by being passed between grooved rollers, or drawn through holes in a plate of steel.
(n.) A telegraph wire or cable; hence, an electric telegraph; as, to send a message by wire.
(v. t.) To bind with wire; to attach with wires; to apply wire to; as, to wire corks in bottling liquors.
(v. t.) To put upon a wire; as, to wire beads.
(v. t.) To snare by means of a wire or wires.
(v. t.) To send (a message) by telegraph.
(v. i.) To pass like a wire; to flow in a wirelike form, or in a tenuous stream.
(v. i.) To send a telegraphic message.
Example Sentences:
(1) They could go out and trade for a pitcher such as the New York Mets’ Bartolo Colón , an obvious choice despite his 41 years, but he would come with an $11m price tag for next season and have to pass through the waiver wires process first – considering the wily mood Billy Beane is in this year, the A’s could be the team that blocks such a move.
(2) The solution to these problems would seem either to reduce the time spent in rectangular wires or to change to a bracket with reduced torque, together with appropriate second order compensations in the archwire or the bracket.
(3) The major difficulty encountered with the current technique is the danger of neurologic injury during the passage and handling of conventional wires, especially in extensive procedures.
(4) I have the BBC app on my phone and it updates me, and I saw the wire ‘Malaysian flight goes missing over Ukraine.’ I’m like, well it’s probably the Russians who shot it down.
(5) For the attachment of adherent cells, microcarriers or wire springs can be applied to increase the internal surface of the bioreactor.
(6) Extraction tools included flexible, telescoping sheaths advanced over the lead to dilate scar tissue and apply countertraction, deflection catheters, and wire basket snares.
(7) It is not same to the stainless steel wire of traditional removable appliances which must be activated every time to produce a little tooth movement.
(8) Whereas in flexion stress all methods showed a sufficient stability, the rotation tests proved, that in case of a dorsal instability of the lower cervical spine, posterior interlaminar wiring or anterior plate stabilization showed no reliable stabilization effect.
(9) Medial canthal tendon resection and tucks or transnasal wiring are then performed.
(10) Overhead wire problems were causing delays on the east coast mainline into London King's Cross.
(11) The steerable guide wire enabled the angioscopic catheter to be accurately and safely inserted into the target lesion in all cases.
(12) The use of wire stylets to facilitate passage of these tubes has increased the chances of unrecognized tracheal intubations, particularly in obtunded patients.
(13) Kirschner improved the wire traction procedure decisevely.
(14) Conservative treatment (immobilisation in a plaster alone) was compared to percutaneous K-wire fixation.
(15) The procedure consists of a Kirschner wire used as the means of traction on the remaining soft tissue of the lower lip, using the upper teeth or pyriform aperture bone as remote fixed points for tissue traction.
(16) Electroencephalographic activity and extracellular discharges from neurons in deep temporal lobe structures were recorded from fine wire microelectrodes chronically implanted in seven psychomotor epileptic patients for diagnostic localization of seizure foci.
(17) Masseter EMG was recorded by fine wire electrodes and amplified by a specially designed amplifier.
(18) Guide-wire fragments retained in the coronary artery system after PTCA are removed either immediately by means of catheter techniques or by urgent operation.
(19) It was smaller than that reported for patients who had received stabilization of the maxilla with intraosseous and maxillomandibular wiring.
(20) At Charity Hospital in New Orleans transverse Kirschner wires have been routinely used to stabilize the zygoma in these cases.