187 research outputs found
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MicroRNA detection on microsensor arrays by SPR imaging measurements with enzymatic signal enhancement.
We investigated sequence-specific and simultaneous microRNA (miRNA) detections by surface plasmon resonance (SPR) imaging measurements on SPR chips possessing an Au spot array modified with probe DNAs based on a miRNA-detection-selective SPR signal amplification method. MiRNAs were detected with the detection limit of the attomole level by SPR imaging measurements for different miRNA concentrations on a single chip. SPR signals were enhanced based on a combination process of sequence-specific hybridization of the miRNA to the probe DNAs, extension reaction of polyadenine (poly(A)) tails by poly(A) polymerase, binding of a ternary complex of T30-biotin/horseradish peroxidase (HRP)-biotin/streptavidin to the poly(A) tails, and the oxidation reaction of tetramethylbenzidine (TMB) on the HRP by providing a blue precipitate on the surface. This process sequence-specifically and dramatically amplified the SPR signals. This is a simple, cost-effective, and feasible signal amplification method based on the organic compound TMB instead of metal nanoparticles
Characterizing Single Polymeric and Protein Nanoparticles with Surface Plasmon Resonance Imaging Measurements
Near-infrared surface plasmon resonance imaging (SPRI) microscopy is used to detect and characterize the adsorption of single polymeric and protein nanoparticles (PPNPs) onto chemically modified gold thin films in real time. The single-nanoparticle SPRI responses, Δ%R_(NP), from several hundred adsorbed nanoparticles are collected in a single SPRI adsorption measurement. Analysis of Δ%R_(NP) frequency distribution histograms is used to provide information on the size, material content, and interparticle interactions of the PPNPs. Examples include the measurement of log-normal Δ%R_(NP) distributions for mixtures of polystyrene nanoparticles, the quantitation of bioaffinity uptake into and aggregation of porous NIPAm-based (N-isopropylacrylamide) hydrogel nanoparticles specifically engineered to bind peptides and proteins, and the characterization of the negative single-nanoparticle SPRI response and log-normal Δ%R_(NP) distributions obtained for three different types of genetically encoded gas-filled protein nanostructures derived from bacteria
Aerosol delivery of trail pheromone disrupts the foraging of the red imported fire ant, \u3ci\u3eSolenopsis invicta\u3c/i\u3e
BACKGROUND: The fire ant, Solenopsis invicta, is one of the most aggressive and invasive species in the world. The trail pheromone Z,E-α-farnesene (91% purity)was prepared, and disruption of worker trail orientation was tested using an ethanol based aerosol formulation presenting a single puff of this compound by airbrush and compressed air. Trail-following behavior was recorded by overhead webcam and ants digitized before and after presentation of the aerosol treatment at four rates (1.6, 16, 160 and 1600 ng cm−2).
RESULTS: Ants preferred 110 ng cm−1 over 11, 1.1 and 0.11 ng cm−1 for trail following. Within seconds of presentation of 1600 ng cm−2, the highest dose tested, trail disruption was observed. Disruption was evident as reduced arrival success and reduction in the trail integrity statistic (r2), as well as increased deviation from the trail (deg). The distribution of walking track angles was also flattened.
CONCLUSIONS: The feasibility of using aerosol for delivery of trail pheromone was demonstrated, but the need for high purity combined with the difficulty of commercial supply makes this technique impractical. However, the commercial production of Z,E-α-farnesene of high purity by industrial biotechnology or from (E)-nerolidol may be possible in future, which would facilitate further development of trail pheromone disruption of S. invicta
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110th Congress
This report will identify and discuss oversight issues and legislation introduced in the 110th Congress to address specific concerns related to how ESA is implemented and how endangered species are managed
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111th Congress
The Endangered Species Act has been one of the more contentious environmental laws. This may stem from its strict substantive provisions, which can affect the use of both federal and nonfederal lands and resources. This report discusses oversight issues and legislation introduced in the 11th Congress to address Endangered Species Act implementation and management of endangered and threatened species
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109th Congress
The 109th Congress is considering proposals to amend the Endangered Species Act (ESA; P.L. 93-205, 16 U.S.C. §§1531-1543). Major issues in recent years have included changing the role of science in decision-making, modifying critical habitat (CH) procedures, incorporating further protection and incentives for property owners, and increasing protection of listed species, among others. In addition, many have advocated enacting as law some ESA regulations promulgated during the Clinton Administration. This report identifies other bills that have been introduced in the 109th Congress to address specific concerns related to how the ESA is implemented and how endangered species are managed
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110th Congress
This report will identify and discuss oversight issues and legislation introduced in the 110th Congress to address specific concerns related to how ESA is implemented and how endangered species are managed, and will be updated periodically to reflect legislative action
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