amounts of input material. [1,2] While the sequencing-by-synthesis technology dominates currently, this technology requires significant sample preparation and amplification steps, the use of costly biological reagents such as fluorescently labeled molecules, and expensive imaging and data handling instruments. [3][4][5][6][7] Singlemolecule sequencing, which does not require amplification and labeling steps, would simplify the entire sequencing process significantly reducing costs and time of acquiring sequencing data, and is thus more adaptable to clinical translation to enable precision medicine even from mass-limited samples such as those provided by liquid biopsies. [8] Nanopores offer a fast and low-cost sequencing platform that does not require labeling and sample amplification. [6,7,[9][10][11][12][13] The basic principle of nanopore sequencing is to electrically drive charged single molecules, either an intact DNA molecule in strand sequencing or individual nucleotides cleaved from the DNA in exonuclease sequencing, [10,[13][14][15] through a nanopore and determine the identity of each constituent nucleotide by monitoring small changes in the ionic current flowing through the pore while individual nucleotides temporarily reside within the pore (i.e., resistive pulse sensing, RPS). [13,16] Strand nanopore sequencing has demonstrated whole-genome sequencing [14] Nanoscale electrophoresis allows for unique separations of single molecules, such as DNA/RNA nucleobases, and thus has the potential to be used as single molecular sensors for exonuclease sequencing. For this to be envisioned, label-free detection of the nucleotides to determine their electrophoretic mobility (i.e., time-of-flight, TOF) for highly accurate identification must be realized. Here, for the first time a novel nanosensor is shown that allows discriminating four 2-deoxyribonucleoside 5'-monophosphates, dNMPs, molecules in a label-free manner by nanoscale electrophoresis. This is made possible by positioning two sub-10 nm in-plane pores at both ends of a nanochannel column used for nanoscale electrophoresis and measuring the longitudinal transient current during translocation of the molecules. The dual nanopore TOF sensor with 0.5, 1, and 5 µm long nanochannel column lengths discriminates different dNMPs with a mean accuracy of 55, 66, and 94%, respectively. This nanosensor format can broadly be applicable to label-free detection and discrimination of other single molecules, vesicles, and particles by changing the dimensions of the nanochannel column and in-plane nanopores and integrating different pre-and postprocessing units to the nanosensor. This is simple to accomplish because the nanosensor is contained within a fluidic network made in plastic via replication.

Various nano- and micro-sized fillers can be integrated into polymers to enhance their flame-retardant performance. In this work, a diglycidyl-ether bisphenol A epoxy was used as the matrix and nanostructured silica aerogel (AG) and ammonium polyphosphate (APP) microparticles were investigated as fillers to improve the flame-retardant and thermal properties of the epoxy. The anti-flame, thermal, and mechanical properties of the composites were investigated for different volume fractions of filler particles. It was found that APP decreased the burning rate while significantly improving the thermal stability. To investigate the flame resistant properties of combined AG and APP, an optimized ratio of AG and APP was added to the epoxy, leading to a stable flame-retardant epoxy with a low thermal conductivity and improved glass transition temperature (Tg). The synergy between the AG and APP in composite samples resulted in an interesting burning behavior where sample core was relatively less deteriorated compared with the samples containing only APP or AG. This was attributed to the decrease of thermal conductivity due to the addition of AG. Lastly, samples containing APP showed the highest limiting oxygen index percentage and it was found that only small amounts of APP are required to make the epoxy flame-retardant.

We report a simple method for tailoring the size of in-plane nanopores fabricated in thermoplastics for single-molecule sensing. The in-plane pores were fabricated via nanoimprint lithography (NIL) from resin stamps, which were generated from Si masters. We could reduce the size of the in-plane nanopores from 30 to ∼10 nm during the thermal fusion bonding (TFB) step, which places a cover plate over the imprinted polymer substrate under a controlled pressure and temperature to form the relevant nanofluidic devices. Increased pressures during TFB caused the cross-sectional area of the in-plane pore to be reduced. The in-plane nanopores prepared with different TFB pressures were utilized to detect single-λ-DNA molecules via resistive pulse sensing, which showed a higher current amplitude in devices bonded at higher pressures. Using this method, we also show the ability to tune the pore size to detect single-stranded (ss) RNA molecules and single ribonucleotide adenosine monophosphate (rAMP). However, due to the small size of the pores required for detection of the ssRNA and rAMPs, the surface charge arising from carboxylate groups generated during O2 plasma oxidation of the surfaces of the nanopores to make them wettable had to be reduced to allow translocation of coions. This was accomplished using EDC/NHS coupling chemistry and ethanolamine. This simple modification chemistry increased the event frequency from ∼1 s–1 to >136 s–1 for an ssRNA concentration of 100 nM.

The primary objective of this study is to investigate the benefits of adding tire rubber as an inclusion to backfill behind integral bridge abutments. In this respect, four physical model tests that enable cyclic loading of the backfill-abutment are conducted and evaluated. Each test consisted of 120 load cycles, and both the horizontal force applied to the top of the abutment wall and the pressures along the wall-backfill interface is measured. The primary variable in this study is the tire rubber content in the backfill soil behind the abutment. Results show adding tire rubber to the backfill would be beneficial for both pressure and settlement behind the abutment. According to results, adding tire rubber to soil decreases the equivalent peak lateral soil coefficient (Keq-peak) up to 55% and earth pressure coefficient ($${K}^{*}$$ K ∗ ) at upper parts of the abutment up to 59%. Moreover, the settlements of the soil behind the wall are decreased up to 60%.