Comparisons of the acoustic radiation force of ultrasonic standing waves in half-wavelength and quarter-wavelength micro-resonators of cylindrical geometry.

Ultrasonic standing waves with specific wavelengths generated in the multi-layered micro-resonators were numerically and experimentally analyzed. Using a three-dimensional scanning fluorescence microscope, the acoustophoretic motion of fluorescent microparticles within the micro-resonators was carefully and accurately measured. The manufactured micro-resonators were validated by comparing the location of the acoustic pressure nodal plane and the average energy density curves derived from numerical and experimental results. Results confirmed that the acoustic radiation force of the induced ultrasonic standing waves drives the microparticles vertically within the micro-resonators and their average energy density increases as the sinusoidal voltage applied to the piezoelectric transducer increases. Semi-empirical correlations were developed for the average energy density, based on experimental results for a wide range of the applied voltage amplitudes. The correlations were in good agreement, within less than 20 % of the experimental values measured for both the half-wavelength and quarter-wavelength micro-resonators.

Subjective criteria underlying noise-tolerance in the presence of speech.

OBJECTIVE: The objective was to determine the relative contribution of four criteria (loudness, annoyance, distraction, speech interference) to participants' noise-tolerance thresholds (NTT). DESIGN: While listening to speech in noise set at the highest signal-to-noise ratio at which noise became unacceptable (noise tolerance threshold), participants completed paired-comparison judgments of loudness, annoyance, distraction, and speech interference to determine the noise domain(s) that were most important in their noise tolerance judgments. Participants also completed absolute ratings of the noise using the same noise domains, which were combined with the paired comparison data for analysis. STUDY SAMPLE: Sixty-three adults with normal hearing participated. RESULTS: For the entire group, speech interference and distraction were the largest contributors to noise tolerance. A cluster analysis indicated three distinct groups: criteria were dominated by either annoyance (33%); distraction (48%), or speech interference (19%). Significant differences in NTT among the groups revealed the highest mean NTT for the annoyance group and lowest NTT for the speech interference group. CONCLUSION: The majority of participants based NTTs on criteria related to the noise itself (annoyance or distraction) and had greater noise sensitivity than the smaller group of participants who focused more on speech intelligibility in the noise.

Sol⁻Gel-Processed Organic⁻Inorganic Hybrid for Flexible Conductive Substrates Based on Gravure-Printed Silver Nanowires and Graphene.

In this study, an organic⁻inorganic (O⁻I) nanohybrid obtained by incorporating an alkoxysilane-functionalized amphiphilic polymer precursor into a SiO2⁻TiO2 hybrid network was successfully utilized as a buffer layer to fabricate a flexible, transparent, and stable conductive substrate for solution-processed silver nanowires (AgNWs) and graphene under ambient conditions. The resulting O⁻I nanohybrid sol (denoted as AGPTi) provided a transmittance of the spin-coated AgNWs on an AGPTi-coated glass of 99.4% and high adhesion strength after a 3M tape test, with no visible changes in the AgNWs. In addition, AGPTi acted as a highly functional buffer layer, absorbing the applied pressure between the conductive materials, AgNWs and graphene, and rigid substrate, leading to a significant reduction in sheet resistance. Furthermore, gravure-printed AgNWs and graphene on the AGPTi-based flexible substrate had uniform line widths of 490 ± 15 and 470 ± 12 µm, with 1000-cycle bending durabilities, respectively.

Ex situ soil washing of highly contaminated silt loam soil using core-crosslinked amphiphilic polymer nanoparticles.

Non-ionic surfactants (Triton X-100 and Brij 30) and core-crosslinked amphiphilic polymer (CCAP) nanoparticles were used as extractants in the ex situ soil washing of silt loam soil contaminated with large quantities of petroleum oil, and their soil-washing performances were compared. Following washing with the surfactants, highly turbid aqueous solutions containing large numbers of soil and petroleum oil particles were produced. In contrast, the CCAP nanoparticles successfully extracted the petroleum oils from the soil samples without the formation of such a turbid aqueous solution. In addition, the CCAP nanoparticles extracted 96% of the petroleum oils, which is a significantly larger quantity than that by Brij 30 and Triton X-100 under equivalent conditions. Indeed, owing to their crosslinked micelle-like structure, the CCAP nanoparticles maintained their nanostructure even upon contact with a highly contaminated silt loam soil matrix, thereby resulting in the extraction of only the hydrophobic oily contaminants from the soil matrix and avoiding the formation of dispersions of soil particles and hydrophobic contaminants. As such, CCAP nanoparticles could be considered as suitable washing materials for highly contaminated silt loam soils.

Use of hybrid composite particles prepared using alkoxysilane-functionalized amphiphilic polymer precursors for simultaneous removal of various pollutants from water.

In this study, we present new inorganic-organic hybrid particles and their possible application as an adsorbent for simultaneous removal of hydrophobic and hydrophilic pollutants from water. These hybrid particles were prepared using tailor-made alkoxysilane-functionalized amphiphilic polymer precursors (M-APAS), which have amphiphilic polymers and reactive alkoxysilane groups attached to the same backbone. Through a single conventional sol-gel process, the polymerization of M-APAS and the chemical conjugation of M-APAS onto silica nanoparticles was simultaneous, resulting in the formation of hybrid particles (M-APAS-SiO2) comprised of hyperbranch-like amphiphilic polymers bonded onto silica nanoparticles with a relatively high grafting efficiency. A test for the adsorption of water-soluble dye (organe-16) and water insoluble dye (solvent blue-35) onto the hybrid particles was performed to evaluate the possibility of adsorbing hydrophilic and hydrophobic compound within the same particle. The hybrid particle was also evaluated as an adsorbent for the removal of contaminated water containing various pollutants by wastewater treatment test. The hybrid particle could remove phenolic compounds from wastewater and the azo dye reactive orange-16 from aqueous solutions, and it was easily separated from the treated wastewater because of the different densities involved. These results demonstrate that the hybrid particles are a promising sorbent for hydrophilic and/or hydrophobic pollutants in water.

Tumor suppression via paclitaxel-loaded drug carriers that target inflammation marker upregulated in tumor vasculature and macrophages.

Clinically approved chemotherapeutic nanoparticles may provide advantages over free drugs by achieving slower clearance and preferential accumulation in tumors. However, the lack of leaky vasculatures can create barriers to the permeation of ~100 nm-sized nanoparticles in solid tumors. We hypothesized that nanoparticles designed to target both tumor and tumor stroma would penetrate deeper into the tumors. To construct such comprehensive drug carriers, we utilized cross-linked amphiphilic polymer nanoparticles and functionalized them to target ICAM-1, a biomarker prevalent in various tumors and inflamed tumor stroma. The targeting moiety was derived from the modular domain present in α(L) integrin, which was engineered for high affinity and cross-reactivity with human and murine ICAM-1. ICAM-1-selective delivery of paclitaxel produced potent tumor suppression of not only ICAM-1-positive cervical cancer cells but also ICAM-1-negative tumors, presumably by causing cytotoxicity in tumor-associated endothelium (CD31(+)) and macrophages (CD68(+)) over-expressing ICAM-1. Contrary to the strategies of targeting only the tumor or specific tumor stromal constituents, we present a strategy in delivering therapeutics to the major cellular components of solid tumors. Drug carriers against inflammation-biomarkers may be effective against many different types of tumors, while being less susceptible to the highly mutable nature of tumor markers.