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Abstract The Middle Triassic Luoping Biota in south-west China represents the inception of modern marine ecosystems, with abundant and diverse arthropods, fishes and marine reptiles, indicating recovery from the Permian–Triassic mass extinction. Here we report a new specimen of the predatory marine reptile Diandongosaurus, based on a nearly complete skeleton. The specimen is larger than most other known pachypleurosaurs, and the body shape, caniniform teeth, clavicle with anterior process, and flat distal end of the anterior caudal ribs show its affinities with Diandongosaurus acutidentatus, while the new specimen is approximately three times larger than the holotype. The morphological characters indicate that the new specimen is an adult of D. acutidentatus, allowing for ontogenetic variation. The fang-like teeth and large body size confirm it was a predator, but the amputated hind limb on the right side indicate itself had been predated by an unknown hunter. Predation on such a large predator reveals that predation pressure in the early Mesozoic was intensive, a possible early hint of the Mesozoic Marine Revolution.

Photolithographically generated patterns are created on immobilized CdSe QD thin films by fine-tuning their optical properties postsynthetically. The optically modified QDs have shown enhanced selectivity for binding of different ligand, which has helped in preparing optically reconfigurable surfaces for display and sensing applications.

The specific ion effects on interfacial water structure next to macromolecules were examined by using vibrational sum frequency spectroscopy (VSFS). The results indicate that the interfacial water structure could be responsible for the consequence of macromolecule-ion interactions.

Protein ion-channel recordings are described by using a glass nanopore (GNP) membrane as the support structure for lipid bilayer membranes. The electrical and mechanical stability of the bilayer and the ability to control ion-channel insertion have provided a new and nearly optimal system for single ion-channel recordings.

Multivalent ligand-receptor interactions are explored between pentameric cholera toxin B subunits (CTB) and the corresponding membrane ligand, ganglioside [GM.sub.1]. The results have shown that CTB binding to [GM.sub.1] is inhibited by the clustering of the glycolipid within the phospholipid membrane.

Aqueous two-phase system (ATPS) formation is the macroscopic completion of liquid-liquid phase separation (LLPS), a process by which aqueous solutions demix into 2 distinct phases. We report the temperature-dependent kinetics of ATPS formation for solutions containing a monoclonal antibody and polyethylene glycol. Measurements are made by capturing dark-field images of protein-rich droplet suspensions as a function of time along a linear temperature gradient. The rate constants for ATPS formation fall into 3 kinetically distinct categories that are directly visualized along the temperature gradient. In the metastable region, just below the phase separation temperature, Tph, ATPS formation is slow and has a large negative apparent activation energy. By contrast, ATPS formation proceeds more rapidly in the spinodal region, below the metastable temperature, Tmeta, and a small positive apparent activation energy is observed. These region-specific apparent activation energies suggest that ATPS formation involves 2 steps with opposite temperature dependencies. Droplet growth is the first step, which accelerates with decreasing temperature as the solution becomes increasingly supersaturated. The second step, however, involves droplet coalescence and is proportional to temperature. It becomes the rate-limiting step in the spinodal region. At even colder temperatures, below a gelation temperature, Tgel, the proteins assemble into a kinetically trapped gel state that arrests ATPS formation. The kinetics of ATPS formation near Tgel is associated with a remarkably fragile solid-like gel structure, which can form below either the metastable or the spinodal region of the phase diagram. [ABSTRACT FROM AUTHOR]

Herein, a simple label-free biosensor fabrication method is demonstrated based on transmission localized surface plasmon resonance (T-LSPR). The platform, which consists of a silver nanoparticle array, can be prepared in just a few minutes using benchtop chemistry. The array was made by a templating technique in conjunction with the photoreduction of Ag ions from solution. This metal surface was functionalized with biotin-linked thiol ligands for binding streptavidin molecules from solution. For an array of 19 nm diameter silver nanoparticles, a redshift in the T-LSPR spectrum of 24 nm was observed upon protein-ligand binding at saturation. The binding constant was found to be 2×1012 M-1. Platforms were also fabricated with silver nanoparticles of 34, 55, and 72 nm diameters. The maximum LSPR wavelength shift was nanoparticle size dependent and the maximum sensitivity was obtained with the smaller nanoparticles. [ABSTRACT FROM AUTHOR]

A method has been designed for patterning supported phospholipid bilayers (SLBs) on planar substrates and inside microfluidic channels. To do this, bovine serum albumin (BSA) monolayers were formed via adsorption at the liquid/solid interface. Next, this interfacial protein film was selectively patterned by using deep UV lithography. Subsequently, SLBs could be deposited in the patterned locations by vesicle fusion. By cycling through this process several times, spatially addressed bilayer arrays could be formed with intervening protein molecules serving as two-dimensional corrals. By employing this method, phospholipid bilayers containing various concentrations of ganglioside GM1 were addressed along the length of individual microfluidic channels. Therefore, the binding of GM1 with pentameric cholera toxin B (CTB) subunits could be probed. A seven-channel microfluidic device was fabricated for this purpose. Each channel was simultaneously patterned with four chemically distinct SLBs containing 0, 0.2, 0.5, and 2.0 mol % GM1, respectively. Varying concentrations of CTB were then introduced into each of the channels. With the use of total internal reflection fluorescence microscopy, it was possible to simultaneously abstract multiple equilibrium dissociation constants as a function of ligand density for the CTB-GM1 system in a single shot. [ABSTRACT FROM AUTHOR]

The present studies explore multivalent ligand-receptor interactions between pentameric cholera toxin B subunits (CTB) and the corresponding membrane ligand, ganglioside GM1. CTB binding was monitored on supported phospholipid bilayers coated on the walls and floors of microfluidic channels. Measurements were made by total internal reflection fluorescence microscopy (TIRFM). Apparent dissociation constants were extracted by fitting the binding data to both the Hill-Waud and Langmuir adsorption isotherm equations. Studies of the effect of ligand density on multivalent CTB-GM1 interactions revealed that binding weakened with increasing GM1 density from 0.02 mol % to 10.0 mol %. Such a result could be explained by the clustering of GM1 on the supported phospholipid membranes, which in turn inhibited the binding of CTB. Atomic force microscopy (AFM) experiments directly verified GM1 clustering within the supported POPC bilayers. [ABSTRACT FROM AUTHOR]

Investigates the ambivalent antibody binding on fluid-supported phospholipid membranes. Effect of hapten density on phospholipid membranes; Ligand-receptor binding between bivalent antibodies and membrane-boun ligands; Function of hapten density in a two-dimensionally fluid environment.

Examines the method of microfluidic measurement to generate a linear temperature gradient for parallel data and combinatorial measurements. Involvement of short length scales of microfluidics; Extension of method to protein crystallization; Additional variable of temperature in combinatorial tool box.

Investigates the design and characterization of immobilized enzymes in microfluidic systems. Possibility of rapid determination of enzyme kinetics by laminar flow controlled dilution; Mechanism of the enzyme immobilization on multiple chemical reactions; Employment of avidinD-conjugated glucose oxidase and streptavidin-conjugated horseradish peroxidase.

Describes a class of microfluidic immunoassays based upon solid supported lipid bilayers. Characteristics of the fluid bilayers used in the experiment; Method of deriving an entire binding curve in a single experiment; Advantages of the methodology for performing heterogeneous assays developed in the experiment over traditional procedures.

Reports on the use of microcontact displacement to generate addressable arrays of aqueous solutions above fluid lipid bilayers. Use of a patterned poly(dimethylsiloxane) mold; Conformal contact of the mold with a phospholipid membrane on a solid supported substrate; Use of the procedure for screening a small library of aqueous-phase molecules.

The article presents a study on lithosynthesis process using luminescent cadmium selenide (CdSe) quantum dots (QDs) thin film. It states that the ability of QD to create spatially addressable platforms with selective optical properties can be used to enhance various applications such as optoelectronics. It illustrates the visible light illumination using CdSe QD thin films and the QDs reversible surface modification.