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Abstract This study introduces localized surface plasmon resonance (L-SPR) mediated heating filter membrane (HFM) for inactivating universal viral particles by using the photothermal effect of plasmonic metal nanoparticles (NPs). Plasmonic metal NPs were coated onto filter membrane via a conventional spray-coating method. The surface temperature of the HFM could be controlled to approximately 40–60 °C at room temperature, owing to the photothermal effect of the gold (Au) NPs coated on them, under irradiation by visible light-emitting diodes. Due to the photothermal effect of the HFMs, the virus titer of H1Npdm09 was reduced by > 99.9%, the full inactivation time being

Hwang et al. demonstrate that a high axial resolution can be achieved even with low numerical aperture (NA) objectives. They show the nano-profile of a basal cell membrane using metal-induced energy transfer and biexponential fluorescence lifetime analysis. The low-NA objective provides a larger field-of-view (FOV), thereby overcoming the limitations of a small FOV of the usually used high-NA objectives.

Abstract Backgrounds Despite the advances of rheumatoid arthritis (RA) therapeutics, several patients do not receive adequate treatment due to the toxicity and/or insufficient response of drugs. The aim of this study is to design photothermally controlled drug release from multifunctional nanoparticles (MNPs) at a near-infrared (NIR) irradiated site to improve therapeutic efficacy for RA and reduce side effects. Methods Au film was deposited onto methotrexate (MTX)-loaded poly(ethylene glycol)-poly(lactic-co-glycolic acid) (PLGA) nanoparticles, resulting in MTX-loaded MNPs. The synergistic effects of MTX-loaded MNPs with NIR irradiation were investigated using RA fibroblast-like synoviocytes (FLSs) and collagen-induced arthritis (CIA) mice. Results Upon NIR irradiation, NIR resonance of the Au half-shell generated heat locally, accelerating MTX release from PLGA nanoparticles. In vivo NIR images of MTX-loaded MNPs indicated effective delivery of the MNPs to the inflamed joints. Moreover, in collagen-induced arthritis mice, MTX-loaded MNPs containing 1/1400 of MTX solution (repeated-dose administration) had therapeutic effects comparable to conventional treatment with MTX solution. In vitro experiments showed higher therapeutic efficacy of MTX-loaded MNPs with NIR irradiation than that of chemotherapy alone. Conclusions A combination therapy of MTX-loaded MNP and NIR irradiation showed durable and good treatment efficacy for the suppression of arthritis in a single administration of small dose of MTX. Our results demonstrate that the treatment modality using drug-loaded MNP with NIR irradiation may be a promising therapeutic strategy for the treatment of RA and allow in vivo NIR optical imaging.

LDL plays an important role in atherosclerotic plaque formation and macrophage differentiation. However, there is no report regarding the oxidation degree of LDL and macrophage differentiation. Our study has shown that the differentiation into M1 or M2 macrophages is related to the lipid oxidation level of LDL. Based on the level of lipid peroxidation, LDL is classified into high-oxidized LDL (hi-oxLDL) and low-oxidized LDL (low-oxLDL). The differentiation profiles of macrophages were determined by surface receptor expression and cytokine secretion profiles. Low-oxLDL induced CD86 expression and production of TNF-α and IL-12p40 in THP-1 cells, indicating an M1 macrophage phenotype. Hi-oxLDL induced mannose receptor expression and production of IL-6 and monocyte chemoattractant protein-1, which mostly match the phenotype of M2 macrophages. Further supporting evidence for an M2 polarization by hi-oxLDL was the induction of LOX-1 in THP-1 cells treated with hi-oxLDL but not with low-oxLDL. Similar results were obtained in primary human monocytes. Therefore, our results strongly suggest that the oxidation degree of LDL influences the differentiation of monocytes into M1 or M2 macrophages and determines the inflammatory fate in early stages of atherosclerosis.

An efficient method for the fabrication of a single electron transistor (SET) using DNA-assisted assembly of nanoparticles is reported. In this method, the DNA molecules function not only as the assembler, but also as the modulator for the electron tunneling behaviors of single electron transistors.

In this paper, the feasibility of utilization of a single element double split-ring resonator as a biosensing device has been demonstrated. The compact resonator has been excited by time-varying magnetic fields generated from the 50 Ω microstrip transmission line. In this work, DNA hybridization is recognized with shift in S21 resonant frequency. When thiol-linked single stranded-DNA is immobilized onto a gold (Au) surface and is then coupled with complementary-DNA, the frequency changes by Δfss-DNA=20 MHz and Δfhybridization=60 MHz, respectively. Thus, it is clear that the resonator can be utilized as a DNA sensing element in the microwave regime. [ABSTRACT FROM AUTHOR]

A study was conducted to analyze the electron t r ansport for a GaN nanorod p-n junction diode grown by molecular beam epitaxy. The data from the study provided insights into the temperature dependent changes in current-voltage curves and thermionic emission.

A long one-dimensional (1D) mesoporous carbon nanofiber was fabricated by using a mesoporous silica nanofiber template. The resulting mesoporous carbon nanofiber showed the unique mesoporous structure of circularly wound nanochannel alignment perpendicular to the long fiber axis and the high gas sorption property, displaying a p-type semiconducting behavior.

An easy and reliable method for the production of patterned monolayers of Co nanoparticles is described. A two-dimensional monolayer of Co nanoparticles is fabricated by spreading a nanoparticle solution over an air-water interface and then transferring it to a hydrophobic substrate by using the Langmuir-Blodgett (LB) method.

We investigated the relationship between defects in graphene and NO2 gas sensitivity of graphene-based gas sensors. Defects were introduced by hydrogen plasma or ultraviolet (UV)/ozone treatment. As the defect concentration increased, the sensitivity was enhanced, and sub-ppb level detection limit was achieved. UV irradiation was used for recovery at room temperature. However, defects generated by ozone treatment, like graphene oxide, were reduced back to graphene by UV irradiation, so the ozone-treated graphene sensor was not stable over time. In contrast, the response of the hydrogenated graphene sensor was very repeatable because defects generated by hydrogenation was stable enough not to be dehydrogenated by UV irradiation. These results demonstrate that the hydrogenated graphene sensor is a highly sensitive and stable NO2 sensor at room temperature. [ABSTRACT FROM AUTHOR]

Neural stem cells (NSCs) are characterized by a capacity for self-renewal, differentiation into multiple neural lineages, all of which are considered to be promising components for neural regeneration. However, for cell-replacement therapies, it is essential to monitor the process of in vitro NSC differentiation and identify differentiated cell phenotypes. We report a real-time and label-free method that uses a capacitance sensor array to monitor the differentiation of human fetal brain-derived NSCs (hNSCs) and to identify the fates of differentiated cells. When hNSCs were placed under proliferation or differentiation conditions in five media, proliferating and differentiating hNSCs exhibited different frequency and time dependences of capacitance, indicating that the proliferation and differentiation status of hNSCs may be discriminated in real-time using our capacitance sensor. In addition, comparison between real-time capacitance and time-lapse optical images revealed that neuronal and astroglial differentiation of hNSCs may be identified in real-time without cell labeling. [ABSTRACT FROM AUTHOR]

We investigated scaling behaviors for NiO nanowire array devices with different nanowire diameters. Plots of the reset current and the third harmonic generation signal as a function of the on-state resistance (R0) show scaling behaviors for all devices, such as NiO film devices. However, the scaling exponents of NiO nanowire devices were different from those of NiO film devices, and hence the fractal dimension estimated from the scaling exponent was smaller for the NiO nanowire devices than for the NiO film devices. This decrease in the fractal dimension was attributed to the confinement of the conducting filaments within each nanowire. [ABSTRACT FROM AUTHOR]

We fabricated a single-electron transistor using DNA-assisted assembly of Au nanoparticles. Most devices exhibited clear Coulomb blockade and oscillations. In contrast to conventional single-electron transistors, however, the period of Coulomb oscillations was observed to depend on the temperature. This temperature dependence is probably ascribed to the temperature dependence of gate capacitance. [ABSTRACT FROM PUBLISHER]

We have synthesized mesoporous TiO2 nanofibers loaded with Au nanoparticles (MTNF-Au) and fabricated single nanofiber-based devices. MTNF-Au devices exhibited surface plasmon enhanced photoconductance under visible light, whereas MTNF devices without Au nanoparticles did not. Moreover, Coulomb oscillations were observed at 4.2 K in MTNF-Au devices, indicating that Au nanoparticles embedded in MTNF-Au played a role of Coulomb islands. These results suggested that the enhanced photoconductance was ascribed to electron tunneling of hot electrons generated by the surface plasmon resonance. [ABSTRACT FROM AUTHOR]

A functional protein of bacteriorhodopsin has been employed for an approach to develop molecular single-electron transistors. A purple-membrane nanofragment shows a characteristic, cyclic, and reproducible I-V curve having negative differential resistance and an on-off peak-to-valley ratio of 660. The conductance increases exponentially with temperature increase with an activation energy of 47 meV, comparable to the charging energy of a bacteriorhodopsin molecule. This with observed I-V scaling relationship indicates that the Coulomb blockade is the primary conductance-limiting feature and that charges are carried by arrayed Coulomb islands of bacteriorhodopsin. [ABSTRACT FROM AUTHOR]

We have investigated resistive switching phenomena in NiO nanowires fabricated using anodized aluminum oxide membranes. We show that NiO nanowires exhibit reversible and bistable resistive switching behaviors like those in NiO thin films. However, compared to NiO thin films, electroforming in NiO nanowires takes place at much lower electric fields. Thus, a 1-μm-long NiO nanowire device operates under 2.5 V and even a 25-μm-long NiO nanowire array operates under 20 V. These results suggest the possibility of developing nanowire-based resistance memory devices. [ABSTRACT FROM AUTHOR]

We have studied the electrical properties of a GaN nanorod p-n junction diode by deep level transient spectroscopy measurements. The p-n junction nanorods were patterned on a SiO2 substrate by using e-beam lithography. In order to confirm the formation of p-n junction, cathodoluminescence and current-voltage measurements, as a function of temperature, were made. The current-voltage curve exhibits strong temperature dependence, suggesting that thermionic emission over a barrier dominates. This barrier most likely corresponds to emission from a deep level in the band. The deep level appears to be an electron trap at Ec-0.40 eV below the conduction band with a capture cross section of 2.22×10 cm2 near the depletion region of the p-n junction. [ABSTRACT FROM AUTHOR]

Uniaxially p-n junction gallium nitride nanowires have been synthesized via metal-organic chemical vapor deposition method. Nanowires prepared on Si(111) substrates were found to grow perpendicular to the substrate, and the transmission electron microscopy studies demonstrated that the nanowires had singlecrystalline structures with a <0001> growth axis. The parallel assembly of the p-n junction nanowire was prepared on a Si substrate with a thermally grown SiO2 layer. The transport studies of horizontal gallium nitride nanowire structures assembled from p- and n-type materials show that these junctions correspond to well-defined p-n junction diodes. The p-n junction devices based on GaN nanowires suspended over the electrodes were fabricated and their electrical properties were investigated.The horizontally assembled gallium nitride nanowire diodes suspended over the electrodes exhibited a substantial increase in conductance under UV light exposure. Apart from the selectivity to different light wavelengths, high responsivity and extremely short response time have also been obtained. [ABSTRACT FROM AUTHOR]