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Continuous lipid bilayers derived from cell membranes for spatial molecular manipulation

Progress with respect to enrichment and separation of native membrane components in complex lipid environments, such as native cell membranes, has so far been very limited. The reason for the slow progress can be related to the lack of efficient means to generate continuous and laterally fluid supported lipid bilayers (SLBs) made from real cell membranes. We show in this work how the edge of a hyd

Accumulation and separation of membrane-bound proteins using hydrodynamic forces

The separation of molecules residing in the cell membrane remains a largely unsolved problem in the fields of bioscience and biotechnology. We demonstrate how hydrodynamic forces can be used to both accumulate and separate membrane-bound proteins in their native state. A supported lipid bilayer (SLB) was formed inside a microfluidic channel with the two proteins streptavidin (SA) and cholera toxin

Effects of surface pressure and internal friction on the dynamics of shear-driven supported lipid bilayers

Supported lipid bilayers (SLBs) are one of the most common model systems for cell membrane studies. We have previously found that when applying a bulk flow of liquid above an SLB the lipid bilayer and its constituents move in the direction of the bulk flow in a rolling type of motion, with the lower monolayer being essentially stationary. In this study, a theoretical platform is developed to model

Sealing of submicrometer wells by a shear-driven lipid bilayer

A supported lipid bilayer (SLB) was formed in a microfluidic channel by vesicle fusion. The SLB, formed on a flat part of the surface, was driven by the shear forces of a bulk flow above the SLB to a part of the surface with embedded submicrometer wells. When using a bulk solution with a pH of 9.5 the advancing lipid bilayer sealed the wells, creating free-spanning membranes, whereas at a pH of 8.

Improving the limit of detection of nanoscale sensors by directed binding to high-sensitivity areas

The revelation of protein-protein interactions is one of the main preoccupations in the field of proteomics. Nanoplasmonics has emerged as an attractive surface-based technique because of its ability to sense protein binding under physiological conditions in a label-free manner. Here, we use short-range ordered holes with a diameter of approximately 150 nm and a depth of approximately 50 nm as a n

Site-specific DNA-controlled fusion of single lipid vesicles to supported lipid bilayers

We investigate the Ca(2+)-triggered fusion of lipid vesicles site-selectively tethered to a DNA-modified supported lipid bilayer array, with the DNA strands designed such that hybridization occurs in a zipperlike fashion. Prior to the addition of Ca(2+), which is observed to induce docking and subsequent fusion (within 200 ms), the vesicles display lateral mobility determined by the number of teth

Self-assembly formation of multiple DNA-tethered lipid bilayers

Inspired by natural cell-cell junctions, where membrane-residing proteins control the separation between two or more membranes without interfering with their integrity, we report a new self-assembly route for formation of multiple highly fluid tethered lipid bilayers with the inter-membrane volume geometrically confined by membrane-anchored DNA duplexes. The formation of multiple planar membrane-m

Kinetic and thermodynamic characterization of single-mismatch discrimination using single-molecule imaging

A single-molecule detection setup based on total internal reflection fluorescence (TIRF) microscopy has been used to investigate association and dissociation kinetics of unlabeled 30mer DNA strands. Single-molecule sensitivity was accomplished by letting unlabeled DNA target strands mediate the binding of DNA-modified and fluorescently labeled liposomes to a DNA-modified surface. The liposomes, ac

Hydrodynamic separation of proteins in supported lipid bilayers confined by gold barriers

Hydrodynamic drag forces generated by liquid flow above a supported lipid bilayer (SLB) can be used to induce lateral movement of molecules protruding from the SLB. Since the velocity of the individual molecules depends on their size and coupling to the lipid bilayer, these forces can also be used to enrich and separate different types of membrane-bound molecules. To improve and better quantify hy

The Preterm Heart in Childhood : Left Ventricular Structure, Geometry, and Function Assessed by Echocardiography in 6-Year-Old Survivors of Periviable Births

BACKGROUND: Preterm birth has been associated with increased risk of cardiovascular morbidity in adult life. We evaluated whether preterm birth is associated with deviating cardiac structure and function before school start.METHODS AND RESULTS: In total, 176 children aged 6 years and born extremely preterm (EXPT; gestational age of 22-26 weeks) and 134 children born at term (control [CTRL]) were s

Swedish Art History : A Selection of Introductory Texts

This is the first extensive overview of Swedish art history written in English. The essays by Swedish scholars of art history present a broad and varied collection of texts including periodic overviews that cover prehistorical times to the 21st century, as well as thematic studies that introduce discussions on everything from political contexts, artist groups and organizations to aspects of gender

Impact of capacitive coupling element design on antenna bandwidth

A coupling element is typically used to excite one of more characteristic modes of a structure to form some desired radiation properties. In particular, non-resonant coupling elements (CEs) are attractive, since it is electrically small and can be more conveniently integrated into the structure, such as the chassis of a mobile terminal. In this case, the chassis is the primary radiator of the mobi

Benchmark problem definition and cross-validation for characteristic mode solvers

In October 2016, the Special Interest Group on Theory of Characteristic Modes (TCM) initiated a coordinated effort to perform benchmarking work for characteristic mode (CM) analysis. The primary purpose is to help improve the reliability and capability of existing CM solvers and to provide the means for validating future tools. Significant progress has already been made in this joint activity. In

Susceptibility mapping of visceral leishmaniasis based on fuzzy modelling and group decision-making methods

Visceral leishmaniasis (VL) is a vector-borne disease, highly influenced by environmental factors, which is an increasing public health problem in Iran, especially in the north-western part of the country. A geographical information system was used to extract data and map environmental variables for all villages in the districts of Kalaybar and Ahar in the province of East Azerbaijan. An attempt t