•Copper nanoparticles increase the fluorescence in doped glasses.•Increase the emission of Rh B is result of its interaction with Cu NPs surface plasmons.•Optimal distances would be increase of fluorescence by orders of magnitude.We present the possibility to increase the emission of Rhodamine B (Rh B) as a result of its interaction with surface plasmons (SF) created by copper nanoparticles (Cu NPs). The optical absorption and emission of Rh B with Cu NPs incorporated into glass films formed by sol–gel method were studied by steady state and picosecond spectroscopy. The observed increased luminescence is the result of interaction of the excited state of the dye with scattered light created by copper plasmons and possible energy transfer from the excited Cu NPs which occur at femptosecond time range. The steady state absorption, excitation, fluorescence and lifetimes excited by picosecond pulses were measured. The quantum efficiencies of the films were obtained by comparative method.
In recent years carbon based devices are exploited for a wide range of applications related to electronics and optoelectronics, due to their unique electrical, optical and mechanical properties. Many sensors, emitters, transistors and logic devices use carbon nanotubes as their major building block. Here we present a technology for inkjet printing of a hybrid tunable detector composed of carbon nanotubes and nanocrystals. The printing can be performed on flexible elastic transparent substrates, as well as on a rigid semiconductor or dielectric substrates. The presented detector is low cost, operates at room temperature and can be printed easily in a large format. We show that these types of sensor function with high quantum efficiency due to a gating effect induced by the light excitation.
In this paper we describe the preparation of novel Near Infrared (NIR) fluorescent nanoparticles for application in medical imaging of colorectal tumors. The nanoparticles are prepared by using only non-covalent binding processes of molecules which are approved for clinical use. The preparation process is based on the precipitation of a polycation, Eudragit-RS, followed by sequential adsorption of a blocking protein, sodium caseinate, NIR fluorescent dye, Indocyanine Green (ICG) and optionally, a targeting molecule, anti-CEA antibody. Fluorescence measurements have shown that these nanoparticles have higher resistance to photobleaching and higher quantum yield relatively to free ICG. Imaging experiments in orthotopic colorectal cancer mice models have shown that these fluorescent nanoparticles are capable of binding to LS174T human colon tumors in vivo with high specificity, even without the targeting molecule. These nanoparticles, composed of all FDA approved materials, open the way to clinical bioimaging and diagnostics of colon cancer.
This is a review on recent developments in the field of conductive nanomaterials and their application in printed electronics, with particular emphasis on inkjet printing of ink formulations based on metal nanoparticles, carbon nanotubes, and graphene sheets. The review describes the basic properties of conductive nanomaterials suitable for printed electronics (metal nanoparticles, carbon nanotubes, and graphene), their stabilization in dispersions, formulations of conductive inks, and obtaining conductive patterns by using various sintering methods. Applications of conductive nanomaterials for electronic devices (transparent electrodes, metallization of solar cells, RFID antennas, TFTs, and light emitting devices) are also briefly reviewed.
Vanadium dioxide is a well-known near room temperature phase transition material with a transition temperature (tau(C)) at 68 degrees C. In this paper, Eu3+ dopant with different doping levels was introduced into the crystal lattice of VO2. The thermochromic properties, including the integrated visible transmittance (T-lum) and the solar modulating ability (Delta T-sol) were favorably affected by the Eu-doping. It is of great interest that the substitution of V4+ by Eu3+ in the VO2 crystal structure reduced the tau(C) from 68 degrees C to 47.5 degrees C with an approximate decreasing rate of 6.5 degrees C/at% up to 4 at%. More importantly, the Eu dopant helped in improving the properties of luminous transmittance and solar modulating ability, which were difficult to be achieved by other dopants.
The welding and sintering of nanomaterials is relevant, for example, to form electrical contacts between metallic particles in printed electronic devices. Usually the welding of nanoparticles is achieved at high temperatures. Here we find that merging of two different metals, silver and gold nanoparticles, occurs on contact at room temperature. The merging process was investigated by experimental and molecular dynamics simulations. We discovered that the merging of these particles is driven by selective wettability of silver nanoparticles, independent of their size and shape (spheres or rods); silver behaves as a soft matter, whereas gold as a hard surface being wetted and retaining its original morphology. During that process, the silver atoms move towards the surface of the Au nanoparticles and wrap the Au nanoparticles in a pulling up-like process, leading to the wetting of Au nanoparticles.
Vanadium dioxide is the most widely researched thermochromic material with a phase transition temperature (tau(c)) of around 68 degrees C, and its thermochromic performance can be enhanced by adding nanoporosity. Freeze-drying has been employed to fabricate nanostructures with different porosities from 16 to 45% by varying the prefreezing temperature and precursor concentration. The luminous transmittance (T-lum) and solar modulating ability (Delta T-sol) are greatly enhanced as a result of increasing pore size and pore density. The freeze-dried sample with 7.5 mL of H2O2 precursor dip-coated at 300 mm/min gives the best combination of thermochromic properties (T-lum approximate to 50%, Delta T-sol = 14.7%), which Surpasses the best combined thermochromic performance reported to date that we are aware of (T-lum approximate to 41%, Delta T-sol = 14.1%).
Neurodegenerative diseases generate the accumulation of specific misfolded proteins, such as PrPSc prions or A-beta in Alzheimer's diseases, and share common pathological features, like neuronal death and oxidative damage. To test whether reduced oxidation alters disease manifestation, we treated TgMHu2ME199K mice, modeling for genetic prion disease, with Nano-PSO, a nanodroplet formulation of pomegranate seed oil (PSO). PSO comprises large concentrations of a unique polyunsaturated fatty acid, Punicic acid, among the strongest natural antioxidants. Nano-PSO significantly delayed disease presentation when administered to asymptomatic TgMHu2ME199K mice and postponed disease aggravation in already sick mice. Analysis of brain samples revealed that Nano-PSO treatment did not decrease PrPSc accumulation, but rather reduced lipid oxidation and neuronal loss, indicating a strong neuroprotective effect. We propose that Nano-PSO and alike formulations may be both beneficial and safe enough to be administered for long years to subjects at risk or to those already affected by neurodegenerative conditions.From the Clinical Editor This team of authors report that a nanoformulation of pomegranade seed oil, containing high levels of a strong antioxidant, can delay disease onset in a mouse model of genetic prion diseases, and the formulation also indicates a direct neuroprotective effect.
The present disclosure is directed to dispersions of a Dead Sea material in oil, the Dead Sea material is present in the dispersions in the form of solid nanoparticles. Further disclosed are formulations comprising the dispersions, method of treating and/or preventing diseases or disorders of the skin comprising topical application of the dispersions or formulations thereof onto a skin of a subject, method of inducing a heat sensation on the skin of a subject by topically applying the dispersions or formulations thereof onto a skin of a subject and methods of prepg. the dispersions. Thus, an oil phase was prepd. by dissolving 1.8 g (9 wt%) Abil Em 90 in 11.48 g (57.4 wt%) cyclomethicone, 1 g (5 wt%) DOW 9041, 0.02 g (0.1 wt%) Vitamin E Acetate and 0.2 g (1 wt%) Retinyl palmitate mixt.; an aq. phase was prepd. by adding a 0.5 g (2.5 wt%) Dead Sea water (40 % dead sea salt, 1 % DSS final concn.) to 4.2 g (21 wt%) deionized water, 0.2 g (1 wt%) glycerol, 0.4 g (2 wt%) 1,3-propane diol and 0.2 g (1 wt%) PVP (MW = 40000); the total wt. of water and oil phase was 20 g; the aq. phase was added to the oil phase while being mixed for 10 min with a high speed homogenizer at a speed of 13000 rpm with or without addnl. sonication; the nanoparticles were obtained by water evapn. at reduced pressure (15 mbar, 50 °C for 40 min); the nanoparticles size obtained in the two processes, with and without sonication, measured by DLS was 99 nm and 255 nm, resp. [on SciFinder(R)]
Disclosed are novel ink formulations based on metal salts and metal complexes dispersed in a suitable liq. carrier. Also disclosed are a method of forming a printing formulation, a process for forming a conductive pattern on a surface region of a substrate using the printing formulation, and a conductive pattern obtainable by the process, wherein said conductive pattern has high oxidn. resistance at ambient atm and low sheet resistance. [on SciFinder(R)]
The present invention relates to the use of pomegranate seed oil and fractions thereof for preventing and treating neurodegenerative diseases. Particularly, the present invention relates to emulsions of the pomegranate oil or fractions thereof for the prevention and treatment of brain diseases, including Creutzfeldt-Jacob disease (CJD) and multiple sclerosis (MS). The pomegranate seed oil or fraction thereof is administered in a form of an emulsion as a medical food, a functional food, a food additive, or a dietary supplement. A self-emulsifying drug delivery system (SEDDS) comprising pomegranate seed oil 31.46%, Tween 80 44%, Span 80 19.5%, and ethanol 4.97% was exemplified. Also, pomegranate oil and punicic acid significantly inhibited the toxic effect of copper in a transgenic mouse model of genetic prion disease, as measured by elevated percentage of cell survival. [on SciFinder(R)]
The introduction of nanostructures has been considered as one of the promising strategies to enhance the thermoelectric performance of bulk materials. In this work, we report a low-cost and facile aqueous solution method to prepare (Sb, Bi)2(Te, Se)3 nanocrystals with controllable composition and morphology by using short ligands containing thiol, acid and amine groups. The control of the morphology of the nanostructures such as nanowires and nanosheets is studied, and both n-type and p-type nanoparticles have been prepared successfully. The results show that the thermal conductivities of these nanocrystals are effectively reduced due to phonon scattering and the thermoelectric performance is affected greatly by the morphology. TE measurements show that the electrical conductivity can be enhanced significantly by using Bi2Te3 nanosheets, and as a result, a maximum thermoelectric figure-of-merit (ZT) of 0.86 is obtained for Bi2Te3 nanosheets at 225 °C. [ABSTRACT FROM AUTHOR]Copyright of Journal of Materials Chemistry C is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)