Combination of glass nanocapillaries with optical tweezers allowed us to detect DNA-protein complexes in physiological conditions. In this system, a protein bound to DNA is characterized by a simultaneous change of the force and ionic current signals from the level observed for the bare DNA. Controlled displacement of the protein away from the nanocapillary opening revealed decay in the values of the force and ionic current. Negatively charged proteins EcoRI, RecA, and RNA polymerase formed complexes with DNA that experienced electrophoretic force lower than the bare DNA inside nanocapillaries. Force profiles obtained for DNA-RecA in our system were different than those in the system with nanopores in membranes and optical tweezers. We suggest that such behavior is due to the dominant impact of the drag force comparing to the electrostatic force acting on a DNA-protein complex inside nanocapillaries. We explained our results using a stochastic model taking into account the conical shape of glass nanocapillaries.
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http://dx.doi.org/10.1021/acs.nanolett.5b03264 | DOI Listing |
Bioinspir Biomim
January 2025
School of Mechatronical Engineering, Beijing Institute of Technology, 5 South Zhonghuancun, Haidian District, Beijing 100081, Beijing, 100081, CHINA.
The wings of birds contain complex morphing mechanisms that enable them to perform remarkable aerial maneuvers. Wing morphing is often described using five wingbeat motion parameters: flapping, bending, folding, sweeping, and twisting. However, owing to a lack of real bird flight data, in-depth studies on the aerodynamic properties of these coupled motions remain scarce.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemical Engineering, Indian Institute of Technology, Guwahati 781039, Assam, India.
Self-organized contact line instabilities (CLI) of a macroscopic liquid crystal (LC) droplet can be an ingenious pathway to generate a large collection of miniaturized LC drops. For example, when a larger drop of volatile solvent (e.g.
View Article and Find Full Text PDFMicromachines (Basel)
December 2024
Department of Mechanical Engineering, Brigham Young University, 350 Engineering Building, Provo, UT 84602, USA.
Recent advancements in Electrowetting on Dielectric (EWOD) systems, such as simplified fabrication, low-voltage actuation, and the development of more reliable materials, are expanding the potential applications of electrowetting actuators. One application of EWOD actuators is in RF devices to enable dynamic reconfiguration and allow real-time adjustments to frequency and bandwidth. In this paper, a method is introduced to actuate a panel using EWOD forces.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Mechanical Engineering, College of Engineering, University of Ha'il, 81451, Ha'il City, Saudi Arabia.
Non-Newtonian fluids are also widely used in a variety of scientific, engineering, and industrial domains, including the petroleum sector and polymer technologies. They are vital in the development of drag-reducing agents, damping and braking systems, food manufacturing, personal protective equipment, and the printing industry. Fluid movement and transport via porous materials draw a lot of attention; they are important in science and technology.
View Article and Find Full Text PDFAnal Chem
January 2025
Nano Lithography and Manufacturing Research Center, Korea Institute of Machinery and Materials, 156 Gajeongbuk-ro, Daejeon 34103, South Korea.
Efficient separation and preconcentration of nanoparticles are crucial in a wide range of biomedical applications, particularly as target substances continue to diminish in size. In this study, we introduce an electric field-assisted membrane system that synergistically combines oversized-pore membranes with an electrokinetic particle retention mechanism. Utilizing Ti/Au-coated poly(tetrafluoroethylene) (PTFE) membranes, our approach generates electrokinetic forces to effectively separate and retain charged nanoparticles even smaller than the pores, achieving a separation efficiency over 99% and a preconcentration factor of 1.
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