scholarly journals Water-structuring molecules and nanomaterials enhance radiofrequency heating in biologically relevant solutions

2016 ◽  
Vol 52 (85) ◽  
pp. 12630-12633 ◽  
Author(s):  
Nadia C. Lara ◽  
Asad A. Haider ◽  
Jason C. Ho ◽  
Lon J. Wilson ◽  
Andrew R. Barron ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Electric Fields ◽  
Biologically Relevant ◽  
Water Structuring ◽  
Radiofrequency Heating ◽  
Potential Applications ◽  
Cancer Hyperthermia

For potential applications in nano-mediated radiofrequency cancer hyperthermia, the nanomaterial under investigation must increase the heating of any aqueous solution in which it is suspended when exposed to radiofrequency electric fields.

scholarly journals Donor Atom Preference of Organoruthenium and Organorhodium Cations on the Interaction with Novel Ambidentate (N,N) and (O,O) Chelating Ligands in Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3586
Author(s):  
Sándor Nagy ◽  
András Ozsváth ◽  
Attila Cs. Bényei ◽  
Etelka Farkas ◽  
Péter Buglyó
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Platinum Group Metal ◽  
Molecular Structures ◽  
Chelating Ligands ◽  
Metal Ion Binding ◽  
Biologically Relevant ◽  
X Ray Crystallography ◽  
Ligand Ratio ◽  
Ph Range

Two novel, pyridinone-based chelating ligands containing separated (O,O) and (Namino,Nhet) chelating sets (Namino = secondary amine; Nhet = pyrrole N for H(L3) (1-(3-(((1H-pyrrole-2-yl)methyl)amino)propyl)-3-hydroxy-2-methylpyridin-4(1H)-one) or pyridine N for H(L5) (3-hydroxy-2-methyl-1-(3-((pyridin-2-ylmethyl)amino)propyl)pyridin-4(1H)-one)) were synthesized via reduction of the appropriate imines. Their proton dissociation processes were explored, and the molecular structures of two synthons were assessed by X-ray crystallography. These ambidentate chelating ligands are intended to develop Co(III)/PGM (PGM = platinum group metal) heterobimetallic multitargeted complexes with anticancer potential. To explore their metal ion binding ability, the interaction with Pd(II), [(η6-p-cym)Ru]2+ and [(η5-Cp*)Rh]2+ (p-cym = 1-methyl-4-isopropylbenzene, Cp* = pentamethyl-cyclopentadienyl anion) cations was studied in aqueous solution with the combined use of pH-potentiometry, NMR and HR ESI-MS. In general, organorhodium was found to form more labile complexes over ruthenium, while complexation of the (N,N) chelating set was slower than the processes of the pyridinone unit with (O,O) coordination. Formation of the organoruthenium complexes starts at lower pH (higher thermodynamic stabilities of the corresponding complexes) than for [(η5-Cp*)Rh]2+ but, due to the higher affinity of [η6-p-cym)Ru]2+ towards hydrolysis, the complexed ligands are capable of competing with hydroxide ion in a lesser extent than for the rhodium systems. As a result, under biologically relevant conditions, the rhodium binding effectivity of the ligands becomes comparable or even slightly higher than their effectivity towards ruthenium. Our results indicate that H(L3) is a less efficient (N,N) chelator for these metal ions than H(L5). Similarly, due to the relative effectivity of the (O,O) and (N,N) chelates at a 1:1 metal-ion-to-ligand ratio, H(L5) coordinates in a (N,N) manner to both cations in the whole pH range studied while, for H(L3), the complexation starts with (O,O) coordination. At a 2:1 metal-ion-to-ligand ratio, H(L3) cannot hinder the intensive hydrolysis of the second metal ion, although a small amount of 2:1 complex with [(η5-Cp*)Rh]2+ can also be detected.

scholarly journals Visible-Light Photoswitching of G-Quadruplex Ligand Binding Mode Allows Reversible Control of G-Tetrad Structure

2020 ◽  
Author(s):  
Michael O'Hagan ◽  
Javier Ramos Soriano ◽  
Susanta Haldar ◽  
Juan Carlos Morales ◽  
Adrian Mulholland ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Visible Light ◽  
Uv Light ◽  
Binding Mode ◽  
High Energy ◽  
Light Sources ◽  
Biologically Relevant ◽  
G Quadruplex ◽  
Potential Applications ◽  
Robust Regulation

<div><p>Photoresponsive ligands for G-quadruplex oligonucleotides (G4) offer exciting opportunities for the reversible regulation of these assemblies with potential applications in biological chemistry and responsive nanotechnology. However, achieving the robust regulation of G4 ligand activity with low-energy visible light sources that are easily accessible and compatible with biological systems remains a significant challenge to realizing these applications. Herein, we report the G4-binding properties of a photoresponsive dithienylethene (DTE). We demonstrate the first example of G4-specific acceleration of the photoswitching kinetics of a small molecule and the visible-light mediated switching of the G4 ligand binding mode in physiologically-relevant conditions, which in turn allows control over the G4 tetrad structure of telomeric G4 in potassium buffer. The process is fully reversible and avoids the need for high-energy UV light. This affords an efficient, practical and biologically-relevant means of control that may be applied in the generation of new responsive G4/ligand supramolecular systems.</p></div><br>

Effect of Dielectric Imperfections on the Electroactive Deformations of Polar Dielectric Elastomers

2019 ◽  
Vol 86 (8) ◽  
Author(s):  
Yanhui Jiang ◽  
Yang Liu
Keyword(s):  
Dielectric Permittivity ◽  
Shear Modulus ◽  
Electric Fields ◽  
Nonlinear Deformation ◽  
Dielectric Elastomers ◽  
Inhomogeneous Deformation ◽  
Polar Dielectric ◽  
Polar Groups ◽  
Deformation Stability ◽  
Potential Applications

We find that the ratio of dielectric permittivity to shear modulus is linearly related to the number of polar groups per polymer chain in polar dielectric elastomers (PDEs). Our discovery is verified via computational modeling and validated by experimental evidences. Based on the finding, we introduce the new concept of dielectric imperfection (DI) and provide some physical insights into understanding it through demonstrating the large nonlinear deformation of PDEs with DIs under electric fields. The results show remarkable DI-induced inhomogeneous deformation and indicate that the size and dielectric permittivity of DIs have a significant impact on the deformation stability of PDEs under electric fields. With this concept, we propose some potential applications of PDEs with DIs.

Development of tannic acid/chitosan/pullulan composite nanofibers from aqueous solution for potential applications as wound dressing

2015 ◽  
Vol 115 ◽  
pp. 16-24 ◽  
Author(s):  
Fenghua Xu ◽  
Baicheng Weng ◽  
Robert Gilkerson ◽  
Luis Alberto Materon ◽  
Karen Lozano
Keyword(s):  
Aqueous Solution ◽  
Tannic Acid ◽  
Wound Dressing ◽  
Composite Nanofibers ◽  
Potential Applications

NOVEL POLYETHYLENIMINE NANOGELS AS POTENTIAL GENE CARRIERS PRODUCED VIA PHOTOCHEMISTRY IN SURFACTANT-FREE AQUEOUS SOLUTION

2006 ◽  
Vol 05 (06) ◽  
pp. 753-756 ◽  
Author(s):  
DONGMEI XU ◽  
JIAHUI YU ◽  
YONGBIAO LIU ◽  
HANWEN SUN ◽  
JINGYING XU ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Transfection Efficiency ◽  
In Vitro Tests ◽  
Gene Carriers ◽  
Polymeric Particles ◽  
Potential Applications ◽  
Novel Method ◽  
Low Toxicity

Cationic polymer nanogels, positively-charged submicrometer polymeric particles that swell in water, have attracted an increasing research attentions in recent years because of their potential applications as gene carriers. In this paper, we report a novel method to synthesize polyethylenimine (PEI) nanogels with sizes ranging from 80 nm to 200 nm via UV irradiation at room temperature in aqueous solution without adding any kind of surfactants. The morphology of the nanoparticles is determined to be spherical. The nanogels are of high stability, high transfection efficiency, low toxicity and low immunogenicity, as having been confirmed by in vivo tests with mice as an animal model, and by in vitro tests with human lung and liver cancer cells as well.

1,8-Naphthyridine Modified Rhodamine B Derivatives: Turn-On Colorimetric Sensor for Cu2+

2014 ◽  
Vol 881-883 ◽  
pp. 1079-1082 ◽  
Author(s):  
Gao Zhang Gou ◽  
He Ping Yan ◽  
Shi Juan Xu ◽  
Na Wu ◽  
Bo Zhou ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Metal Complex ◽  
Rhodamine B ◽  
Ring Opening ◽  
High Selectivity ◽  
Colour Change ◽  
Detection Mechanism ◽  
Biologically Relevant ◽  
Turn On

A 1,8-naphthyridine modified rhodamine B derivative, one Cu2+-selective chemosensors was designed, synthesized and characterized, which display a high selectivity for Cu2+among environmentally and biologically relevant metal ions. It can detect Cu2+in aqueous solution selectively with a dramatic colour change from colorless to magenta. The detection mechanism involves a ring-opening process as a consequence of metal complex formation. Jobs plots study indicated that the chemosensor chelated Cu2+with 2:1 stoichiometry.

Monoaromatic Pollutant Removal by Carbon Nanotubes from Aqueous Solution

2012 ◽  
Vol 488-489 ◽  
pp. 934-939 ◽  
Author(s):  
Hamidreza Pourzamani ◽  
Bijan Bina ◽  
Mohammad Mehdi Amin ◽  
Alimorad Rashidi
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Water Solubility ◽  
Pollutant Removal ◽  
Water And Wastewater Treatment ◽  
Potential Applications ◽  
Good Potential ◽  
Equilibrium Amount ◽  
Water And Wastewater ◽  
Best Fit

The removal of monoaromatic (benzene (B) and toluene (T)) from aqueous solution by multi walled, single walled, and hybrid carbon nanotubes (MWCNTs, SWCNTs, and HCNTs) was evaluated for a nanomaterial dose of 1 g/l, concentration of 10-100 mg/l, and pH 7. The equilibrium amount removed by SWCNTs (B: 9.98 mg/g and T: 9.96 mg/g) was higher than for MWCNTs and HCNTs. Toluene has a higher adsorption tendency on CNTs than benzene, which is related to the increasing water solubility and the decreasing molecular weight of the compounds. The SWCNTs performed better for B and T sorption than the MWCNTs and HCNTs. Isotherms study based on isofit program, indicate that the Generalized Langmuir-Freundlich (GLF) isotherm expression provides the best fit for benzene sorption and Brunauer-Emmett-Teller (BET) isotherm is the best fit for toluene adsorption by SWCNT. SWCNTs are efficient B and T adsorbents and possess good potential applications to water and wastewater treatment and maintain water of high quality that could be used for cleaning up environmental pollution.

scholarly journals Mechanoresponsive scatterers for high-contrast optical modulation

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Donghwi Cho ◽  
Haomin Chen ◽  
Jonghwa Shin ◽  
Seokwoo Jeon
Keyword(s):  
Energy Consumption ◽  
Electric Fields ◽  
Structural Parameters ◽  
Future Research ◽  
Great Promise ◽  
Design Strategies ◽  
Smart Windows ◽  
Advantages And Disadvantages ◽  
Potential Applications ◽  
External Stimuli

Abstract Smart chromatic materials with optical transmittances that can be modified by light scattering upon external stimuli are attracting extensive interest because of their appealing applications in smart windows, privacy protection, electronic displays, etc. However, the development of these scatterers, which are mostly activated by electric fields, is hindered by their intrinsic energy consumption, slow responses, and poor stability. Recently, mechanoresponsive scatterers based on a strain-driven reconfiguration of the surface or internal structure have emerged, featuring fast responses and a simple composition/fabrication. Because there is no energy consumption to maintain the transparency/opacity, this novel scheme for scatterers holds great promise to break the existing bottleneck. This article presents recent advances in the development of mechanoresponsive scatterers and compares different structural design strategies. The scatterers are categorized into 2D, 3D, and other types according to the dimensions of their functioning structures. The fabrication methods, mechanisms, and relationships between the structural parameters and optical modulating performances are discussed for each category. Next, the potential applications of these scatterers are outlined. Finally, the advantages and disadvantages of the mainstream 2D and 3D categories are summarized, followed by a perspective on future research directions.

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