Water Leads (water + lead)

Distribution by Scientific Domains

Selected Abstracts

Self-Association Based on Interfacial Structured Water Leads to {Mo154},1165 Super Clusters: A Dielectric Study

CHEMPHYSCHEM, Issue 5 2007
Alla Oleinikova Dr.
Surface water does the job: Molybdenum blue solutions contain unique nanosized wheel-shaped polyoxometalate-type clusters, while structured surface water on the clusters initiates the assembly, leading to the super cluster shown in the figure, which contains an internal "water pool". [source]

Facile Fabrication of Pure ,-Fe2O3 Nanoparticles via Forced Hydrolysis Using Microwave-Assisted Esterification and their Sensing Property

Yafeng Li
In this paper we firstly demonstrate a facile approach for the rapid fabrication of ,-Fe2O3 using microwave-assisted esterification. In situ -generated water leads to the forced hydrolysis of Fe3+. Microwave irradiation greatly promotes the growth of ,-Fe2O3 nanoparticles compared with conventional solvothermal approach, and agitation can assure the obtainment of pure hematite phase. The akaganeite phase is preserved without stirring. The BET specific surface area reaches 83 m2/g although high concentration of FeCl3 is adopted. Our approach can assure the very rapid acquisition of hematite nanoparticles. Electrochemical studies indicate that our product can function as a candidate for high-performance sensor. [source]

Cationic and Anionic Conjugated Polyelectrolytes: Aggregation-Mediated Fluorescence Energy Transfer to Dye-Labeled DNA

Youngeup Jin
Abstract An electrostatic complex of water-soluble conjugated polyelectrolytes (CPs) between anionic poly(9,9-bis(4,-sulfonatobutyl)fluorene- co-alt -1,4-phenylene) disodium salt (a-PFP) and cationic poly(9,9-bis((6,- N,N,N,-trimethylammonium)hexyl)fluorene- co -2,1,3-bezothiadiazole) dibromide (85:15) (c-PFB15) was tested as a fluorescence resonance energy transfer (FRET) donor to Texas Red (TR)-labeled single-stranded DNA (ssDNA-TR) via two-step FRET processes. Electrostatic complexation of a-PFP and c-PFB15 in water leads to aggregation of polymer chains, a concomitant reduction of intersegment distances, and energy transfer to the benzothiadiazole (BT) segments. The following complexation with ssDNA-TR leads to energy transfer from BT to TR via two-step FRET processes. This detection schematic shows an FRET-induced signal amplification, which can be achieved by adjusting the charge ratio in the cationic/anionic CP complex and controlling the number density of the binding CPs around the acceptor, resulting in enhanced antenna effects and sensitivity in CP-based FRET DNA detection assays. [source]

Heating-induced conformational change of a novel ,-(1,3)- D -glucan from Pleurotus geestanus

BIOPOLYMERS, Issue 2 2010
Mei Zhang
Abstract Recently, we isolated and purified a neutral polysaccharide (PGN) from edible fungus Pleurotus geestanus. Its structure was characterized by a range of physical,chemical methods, including high performance anion exchange chromatography, uronic acid, and protein analyses, size exclusion chromatography with ultraviolet, refractive index and light scattering detectors, and nuclear magnetic resonance. Our results revealed that PGN is a novel ,-(1,3)- D -glucan with glucose attached to every other sugar residues at Position 6 in the backbone. It has a degree of branching of 1/2. Such structure is different from typical ,-(1,3)- D -glucans schizophyllan and lentinan in which DB is 1/3 and 2/5, respectively. Rheological study showed a very interesting melting behavior of PGN in water solution: heating PGN in water leads to two transitions, in the range of 8,12.5C and 25,60C, respectively. The melting behavior and conformational changes were characterized by rheometry, micro-differential scan calorimetry, atomic force microscopy, static and dynamic light scattering at different temperatures. The first heating-induced transition corresponds to the disintegration of polymer bundles into small helical clusters, resembling the heating-induced dissociation of SPG in water at 7C; the second one might correspond to the dissociation of helical strands to individual chains. The ability of PGN to undergo a conformation/viscosity transition in water upon heating is very valuable to immobilize cells or enzymes or therapeutic DNA/RNA, which makes PGN a potentially useful biomaterial. 2009 Wiley Periodicals, Inc. Biopolymers 93: 121,131, 2010. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source]