Multifunctional hybrid nanomaterials with enhanced therapeutic efficiency at physiologically safe dosages for externally triggered, image-guided therapy are highly attractive for nanomedicine. Here, ...we demonstrate a novel class of multifunctional hybrid nanopatches comprised of graphene oxide (GO) and gold nanostars for enhanced photothermal effect and image-guided therapy. The hybrid nanopatches with tunable localized surface plasmon resonance into the near-infrared therapeutic window (650-900 nm) were realized using a biofriendly method that obviates the need for toxic shape-directing agents. Internalization of the intact nanopatches into epithelial breast cancer cells was confirmed by Raman imaging, transmission electron microscopy, and inductively coupled plasma mass spectrometry. It appears that the amphipathic nature and the large surface area of the graphene oxide enable it to serve as a soft, flexible, and biocompatible intracellular carrier for the in situ grown plasmonic nanostructures and provide long-term biocompatibility with extremely low cytotoxicity. Apart from a remarkably improved photothermal effect compared to that of either of the components at very low dosages of the hybrids (10 μg/mL GO) and using a low laser power (0.75 W cm(-2)), the hybrid nanopatches exhibit strong Raman scattering, making them excellent candidates for bioimaging, diagnostics, and image-guided therapy applications.
Polyamide (PA) semipermeable membranes typically used for reverse osmosis water treatment processes are prone to fouling, which reduces the amount and quality of water produced. By synergistically ...coupling the photothermal and bactericidal properties of graphene oxide (GO) nanosheets, gold nanostars (AuNS), and hydrophilic polyethylene glycol (PEG) on PA reverse osmosis membrane surfaces, we have dramatically improved fouling resistance of these membranes. Batch fouling experiments from three classes of fouling are presented: mineral scaling (CaCO3 and CaSO4), organic fouling (humic acid), and biofouling (Escherichia coli). Systematic analyses and a variety of complementary techniques were used to elucidate fouling resistance mechanisms from each layer of modification on the membrane surface. Both mineral scaling and organic fouling were significantly reduced in PA-GO-AuNS-PEG membranes compared to other membranes. The PA-GO-AuNS-PEG membrane was also effective in killing all near-surface bacteria compared to PA membranes. In the PA-GO-AuNS-PEG membrane, the GO nanosheets act as templates for in situ AuNS growth, which then facilitated localized heating upon irradiation by an 808 nm laser inactivating bacteria on the membrane surface. Furthermore, AuNS in the membrane assisted PEG in preventing mineral scaling on the membrane surface. In flow-through flux and foulant rejection tests, PA-GO-AuNS-PEG membranes performed better than PA membranes in the presence of CaSO4 and humic acid model foulants. Therefore, the newly suggested membrane surface modifications will not only reduce fouling from RO feeds, but can improve overall membrane performance. Our innovative membrane design reported in this study can significantly extend the lifetime and water treatment efficacy of reverse osmosis membranes to alleviate escalating global water shortage from rising energy demands.
Owing to their unique properties and potential applications in nanoelectronics, graphene and its derivatives have received extensive attention over the last decade. Noble metal nanostructures, on the ...other hand, enable the confinement and manipulation of light at the nanoscale. Integration of nanocarbons and plasmonic nanostructures is expected to result in synergistic optoelectronic properties that can potentially revolutionize the design and fabrication of optoelectronic devices. In this letter, we demonstrate a simple self-assembly approach to achieve synergistic ensemble of plasmonic gold nanostars and graphene oxide. Gold nanostars are directly nucleated and grown on the surface of graphene oxide by in situ reduction method producing differential surface charged hybrid macroanionic sheets, which are then kinetically rolled and simultaneously assembled into high aspect ratio hybrid nanorolls by means of the interplay of kinetics and graphene–gold interactions.
The Large Hadron electron Collider (LHeC) is a proposed future particle-physics project colliding 60 GeV electrons from a six-pass recirculating energy-recovery linac (ERL) with 7 TeV protons stored ...in the LHC. The ERL technology allows for much higher beam current and, therefore, higher luminosity than a traditional linac. The high-current, high-energy electron beam can also be used to drive a free electron laser (FEL). In this study, we investigate the performance of an LHeC-based FEL, operated in the self-amplified spontaneous emission mode using electron beams after one or two turns, with beam energies of, e.g., 10, 20, 30 and 40 GeV, and aim at producing x-ray pulses at wavelengths ranging from 8 to 0.5 Å. In addition, we explore a possible path to use the 40 GeV electron beam for generating photon pulses at much lower wavelengths, down to a few picometer. We demonstrate that such ERL-based high-energy FEL would have the potential to provide orders of magnitude higher average brilliance at Å wavelengths than any other FEL either existing or proposed. It might also allow a pioneering step into the picometer wavelength regime.
Owing to their unique optical properties such as large absorption and scattering cross section and large enhancement of electromagnetic field at the surface, plasmonic nanostructures have received ...extensive attention as a highly promising class of materials for nano-oncology. Most of the existing plasmonic nanostructures require extensive post-synthesis treatments and biofunctionalization routines to mitigate their cytotoxicity and/or make them tumor-specific. Here, we report one-pot synthesis of a novel class of plasmonic nanostructures, namely, gold nanoraspberries (GRBs) with tunable size and localized surface plasmon resonance by using a naturally abundant polysaccharide, chitosan, which acts as a template and capping agent. Significantly, the GRBs, which do not require any further biofunctionalization, exhibit excellent selectivity to tumor cells, thus enabling locoregional therapy at the cellular level. We demonstrate the tumor-selectivity of GRBs by photothermal ablation of tumor cells selectively from their co-culture with normal cells. The simple, scalable and tumor-selective nature of GRBs makes them excellent candidates for translational plasmonics-based nanomedicine.
Free electron laser (FEL) facilities provide broadly tunable and highly coherent photon beams. These machines still have an unexplored potential and development. The XLS-CompactLight design aims at a ...flexible hard plus soft X-ray FEL facility exploiting the latest concepts in terms of short period magnetic undulators, paving the road towards more compact photon sources.
Gamma-proton collisions allow unprecedented investigations of the low
x and high
Q
2
regions in quantum chromodynamics. In this paper, we investigate the luminosity for “
ILC”
×
LHC
(
s
ep
=
1.3
TeV
...)
and “
CLIC”
×
LHC
(
s
ep
=
1.45
TeV
)
based
γ
p
colliders. Also we determine the laser properties required for high conversion efficiency.
We report new evidence on the surface defect dependent fibrillation of cysteine-free gold-binding peptides (identified from a phage-display peptide library) upon adsorption onto the Au(111) surface ...revealed using atomic force microscopy (AFM). Dramatic changes in the persistence length and binding conformation of the peptide fibrils on Au(111) have been demonstrated to occur via surface reorganization of the peptide. Moreover, surface defect sites played a governing role in initiating fibrillation. These observations could provide new insight into engineering bio-nano interfaces for self-assembly, biotemplating and biotic-abiotic hybrid material systems and device platforms.
Doped yttrium aluminum garnet, Y3Al5O12 (YAG), has drawn considerable attention for solid‐state industrial, medical, and scientific laser applications. The crystal optical activity is closely related ...to the type and amount of doping element. Studies on highly yttrium‐doped, creep‐resistant alumina ceramics with Ca and Si contamination have indicated that YAG precipitates in the ceramic had a propensity to allow the simultaneous incorporation of Ca and Si impurities on the order of 1% into their structure. The cosolubility potential for Ca and Si in YAG crystals was investigated through systematic doping and codoping of YAG polycrystals with Ca2+ and/or Si4+. It was shown via X‐ray diffraction and electron probe microanalysis techniques that the ceramic can accommodate more than an order of magnitude amounts of Ca2+ and Si4+ when they are incorporated in equal amounts simultaneously than when they are introduced alone. The cosolubility limit for Ca and Si was determined to be between 3% and 4% of the cation amount in pure YAG. Enhanced co‐solubility was discussed in terms of size and charge compensations in the lattice. Codoping with a suitable element is introduced as a possible way to increase the solubility of useful cations in this ceramic, which is the host material for lasers.
Demineralized Beypazari lignite were thermally decarboxylated using Cr
2+
, Fe
2+
, and Co
2+
as decarboxylation catalysts. Effective loadings of Cr
2+
, Fe
2+
, and Co
2+
were 2, 5, and 3%, ...respectively. The calorific values of the demineralized lignite samples increased after the thermal decarboxylation experiments to values about 6, 12, and 15% higher than that of the untreated demineralized sample, when Cr
2+
, Fe
2+
, and Co
2+
, respectively, were used as catalysts. The most effective catalyst, with respect to the lowest activation energy attained, was Cr
2+
. Decarboxylation temperatures using Cr
2+
, Fe
2+
, and Co
2+
as catalysts were 150, 100, and 200°C, respectively.
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