Bioretention cells, or rain gardens, can effectively reduce many contaminants in polluted stormwater through phytoremediation and bioremediation. The vegetated soil structure develops bacterial communities both within the soil and around the vegetation roots that play a significant role in the bioremediative process. Prediction of a bioretention cell's performance and efficacy is essential to the design process, operation, and maintenance throughout the design life of the cell.
View Article and Find Full Text PDFHydrogel structures with microscale morphological features have extensive application in tissue engineering owing to their capacity to induce desired cellular behavior. Herein, we describe a novel biofabrication method for fabrication of grooved solid and hollow hydrogel fibers with control over their cross-sectional shape, surface morphology, porosity, and material composition. These fibers were further configured into three-dimensional structures using textile technologies such as weaving, braiding, and embroidering methods.
View Article and Find Full Text PDFIndividually-addressable nano-electro-mechanical (NEMS) devices have been used to demonstrate sensitive mass detection to the single-proton level, as well as neutral-particle mass spectrometry. The cost of individually securing or patterning such devices is proportional to their number or the chip area covered. This limits statistical support for new research, as well as paths to the commercial availability of extraordinarily sensitive instruments.
View Article and Find Full Text PDFThere is widespread interest in circulating tumor cells (CTCs) in blood. Direct detection of CTCs (often < 1/mL) is complicated by a number of factors, but the presence of ∼10(3) to 10(4) copies of target RNA per CTC, coupled with simple enrichments, can greatly increase detection capability. In this study we used resonance frequency shifts induced by mass-amplifying gold nanoparticles to detect a hybridization sandwich bound to functionalized nanowires.
View Article and Find Full Text PDFThere is great interest in the detection of circulating tumour cells (CTCs) as an important diagnostic and prognostic indicator for patients with many (if not all) types of cancer, and many studies have established that the absolute level of CTCs is a critical determinant. Given that, most studies in the field now utilise reverse transcription/polymerase chain reaction-based measurements, focussing on selected marker RNAs for the particular tumour type. However, such measurements mandate choosing the marker RNAs in advance, and only a limited number of markers can be examined in the reactions.
View Article and Find Full Text PDFDirected-assembly of nanowire-based devices will enable the development of integrated circuits with new functions that extend well beyond mainstream digital logic. For example, nanoelectromechanical resonators are very attractive for chip-based sensor arrays because of their potential for ultrasensitive mass detection. In this letter, we introduce a new bottom-up assembly method to fabricate large-area nanoelectromechanical arrays each having over 2,000 single-nanowire resonators.
View Article and Find Full Text PDFMetal resonators can significantly extend the scope of nanoelectromechanical systems (NEMS) through access to a broader range of electrical, thermal, and surface properties. The material behavior of template-electrodeposited gold (Au) and rhodium (Rh) nanowires (NWs) and their performance as resonators was investigated. Nanowire integration by a bottom-up assembly scheme enabled creation of fixed-free metal beams without distortion or tension.
View Article and Find Full Text PDFWe demonstrate electrorotation of metal nanowires phase-locked to a driving alternating current electric field. Field rotation was accomplished by a low-frequency signal that modulates the amplitude of the high-frequency field. Steady, synchronous rotation of the nanowires was observed for frequencies up to a maximum rotational frequency, which depends on the magnitude of the applied electric field.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
March 2004
Resonance oscillations of micrometer and nanometer scale beams in gases and liquids have increasingly important applications in physics and biology. In this work, we calculate fluid damping and its effect on damped resonance frequency omega(d), and quality factor Q, for oscillating long beams at micrometer and submicrometer scales. For beams of nanometer scale, which are smaller than the mean free path of air molecules at standard conditions, the continuum limit breaks down and the commonly used Stokes drag calculation must be replaced by the appropriate calculation for rarefied gas flow.
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