Programming circuitry for synthetic biology As techniques become more powerful, researchers are anticipating a future in which the design of biological circuits will be similar to integrated electronics. Nielsen et al. describe what is essentially programming language computational living cells. The generated on plasmids expressed Escherichia coli required careful insulation from their genetic context, but primarily functioned as specified. could, example, regulate cellular functions...

A technique is described for the measurement of fluid temperatures in microfluidic systems based on temperature-dependent fluorescence. The easy to implement with a standard fluorescence microscope and CCD camera. In addition, method can be used measure micrometer spatial resolution millisecond time resolution. efficacy demonstrated by measuring temperature distributions resulting from Joule heating variety circuits that are electrokinetically pumped. With equipment these measurements,...

A preformed T-microchannel imprinted in polycarbonate was postmodified with a pulsed UV excimer laser (KrF, 248 nm) to create series of slanted wells at the junction. The presence leads high degree lateral transport within channel and rapid mixing two confluent streams undergoing electroosmotic flow. Several mixer designs were fabricated investigated. All relatively successful low flow rates (0.06 cm/s, ≥75% mixing), but had varying degrees success (0.81 45−80% mixing). For example, one...

Research Article| March 01, 2007 Shale gas potential of the Lower Jurassic Gordondale Member, northeastern British Columbia, Canada Daniel J.K. Ross; Ross Department Geological Sciences, University 6339 Stores Road, Vancouver, BC V6T 1Z4, dross@eos.ubc.ca Search for other works by this author on: GSW Google Scholar R. Marc Bustin 1Z4 Author and Article Information Publisher: Canadian Society Petroleum Geologists Received: 27 Sep 2006 Accepted: 15 Dec First Online: 02 Mar 2017 Online ISSN:...

When a liquid droplet is put onto surface, two situations distinguishable by the contact angle may result. If zero, spreads across situation referred to as complete wetting. On other hand, if between 0° and 180°, does not spread, called partial A wetting transition surface phase from We review key experimental findings on this transition, together with simple theoretical models that account for experiments.

A new technique is described for the concentration and separation of ionic species in solution within microchannels or capillaries. Concentration achieved by balancing electrophoretic velocity an analyte against bulk flow presence a temperature gradient. With appropriate buffer, gradient can generate corresponding velocity, so that velocities sum to zero at unique point, will be focused point. The demonstrated variety analytes, including fluorescent dyes, amino acids, DNA, proteins,...

Abstract Accurate measurements of promoter activities are crucial for predictably building genetic systems. Here we report a method to simultaneously count plasmid DNA, RNA transcripts, and protein expression in single living bacteria. From these data, the activity units RNAP/s can be inferred. This work facilitates reporting promoters absolute units, variability their across population, quantitative toll on cellular resources, all which provide critical insights engineering.

Electroosmotic flow (EOF) is commonly utilized in microfluidics. Because the direction of EOF can be determined by substrate surface charge, control chemical state offers potential, addition to voltage control, direct microfluidic devices. We report use polyelectrolyte multilayers (PEMs) alter charge and polystyrene acrylic Relatively complex patterns with simple arrangements applied voltages are realized derivatization different arms a single device oppositely charged polyelectrolytes. In...

We have characterized electroosmotic flow in plastic microchannels using video imaging of caged fluorescent dye after it has been uncaged with a laser pulse. studied composed single material, poly(methyl methacrylate) (acrylic) or poly(dimethylsiloxane) (PDMS), as well hybrid both materials. Plastic used this study were fabricated by imprinting molding micromachined silicon template the stamping tool. examined dispersion and compared results obtained fused-silica capillary. For PDMS...

Article30 March 2021Open Access Source DataTransparent process The genotype-phenotype landscape of an allosteric protein Drew S Tack orcid.org/0000-0002-9380-4643 National Institute Standards and Technology, Gaithersburg, MD, USA Search for more papers by this author Peter D Tonner orcid.org/0000-0003-2840-0930 Abe Pressman Nathan Olson orcid.org/0000-0003-2585-3037 Sasha F Levy orcid.org/0000-0002-0923-1636 SLAC Accelerator Laboratory, Menlo Park, CA, Joint Initiative Metrology in Biology,...

Large-scale measurements linking genetic background to biological function have driven a need for models that can incorporate these data reliable predictions and insight into the underlying biophysical system. Recent modeling efforts, however, prioritize predictive accuracy at expense of model interpretability. Here, we present LANTERN (landscape interpretable nonparametric model, https://github.com/usnistgov/lantern ), hierarchical Bayesian distills genotype–phenotype landscape (GPL)...

A pulsed UV excimer laser (KrF, 248 nm) was used to modify the surface charge on side wall of hot-embossed microchannels fabricated in a poly(methyl methacrylate) substrate. Subablation level fluences, less than 2,385 mJ/cm2, were prevent any changes physical morphology surface. It is shown that electroosmotic mobility, induced by an electric field applied along length channel, increases average 4% regions have been exposed pulses compared nonexposed regions. Furthermore, application...

Acrylamide-modified DNA probes are immobilized in polycarbonate microfluidic channels via photopolymerization a polyacrylamide matrix. The resulting polymeric, hydrogel plugs porous under electrophoretic conditions and hybridize with fluorescently tagged complementary DNA. double-stranded can be chemically denatured, the chip may reused new analytical sample. Conditions for photopolymerization, hybridization, denaturation discussed. We also demonstrate of containing different probe sequences...

Flow instabilities are well known to occur in macroscopic flows when elastic fluids flow along curved streamlines. In this work we use visualization study the mechanism underlying a purely instability for Poiseuille micro (μ)channel having zigzag path (curved streamlines) and quantitatively investigate its implications fluid mixing (studied by fluorescence microscopy) μchannel. We find that enhances over range of applied rates. For Newtonian streams, occurs molecular diffusion, and, as...

Abstract Glycolytic interconversion of phosphoglycerate isomers is catalysed in numerous pathogenic microorganisms by a cofactor-independent mutase (iPGM) structurally distinct from the mammalian cofactor-dependent (dPGM) isozyme. The iPGM active site dynamically assembles through substrate-triggered movement phosphatase and transferase domains creating solvent inaccessible cavity. Here we identify alternate ligand binding regions using nematode to select enrich lariat-like ligands an...

<title>Abstract</title> Biocatalysts are championed for their exquisite stereochemistry, but slow chromatographic separations necessary to measure enantiomeric excess can bottleneck development. To overcome this limitation, we generate enantioselective transcription factors (eTFs) that convert enantiomer-specific analyte concentrations into programmable gene expression outputs. Using a massively parallel reporter assay, dose-response curves over 300,000 factor variants in response...

The prediction of epistasis, or the interaction between mutations, is a complex challenge impacting protein science, healthcare, and biotechnology. For allosteric proteins, epistatic effects further complicated by intricate networks conformational states binding interactions inherent to their function. Here, we explore these issues systematically comparing biophysical phenomenological models analyze mutational epistasis for lac repressor protein, LacI. Using an extensive dataset consisting...

We have measured the wetting phase diagram of ${}^{3}$He${\ensuremath{-}}^{4}$He mixtures on cesium between 0.6 and 2.1 K, pure ${}^{4}$He temperature. The surface tensions which determine behavior are strongly dependent excess ${}^{3}$He. shows that there bound states ${}^{3}$He at Cs-He interface, analogous to Andreev liquid-vapor interface. binding energy these is approximately 2 K.

A new technique is demonstrated for the simultaneous concentration and high-resolution separation of chiral compounds. With temperature gradient focusing, a combination gradient, an applied electric field, buffer with temperature-dependent ionic strength used to cause analytes move equilibrium, zero-velocity points along microchannel or capillary. Different are thus separated spatially concentrated in manner that resembles isoelectric focusing but applicable greater variety including small...

The adsorption of ${}^{3}$He${\ensuremath{-}}^{4}$He mixtures on a cesium substrate has been measured near bulk liquid phase separation. A first order wetting transition is found the three coexistence line at ${T}_{w}\ensuremath{\cong}0.53$ K. ${}^{3}$He rich wets surface below ${T}_{w}$, and layered films ${}^{4}$He under layer wet above ${T}_{w}$. associated with this to extend both sides line. On side it becomes triple point induced dewetting transitions.

Research Article| December 01, 2006 Sediment geochemistry of the Lower Jurassic Gordondale Member, northeastern British Columbia Daniel J.K. Ross; Ross Department Geological Sciences, University Columbia, 6339 Stores Road, Vancouver, BC V6T 1Z4 Search for other works by this author on: GSW Google Scholar R. Marc Bustin Author and Article Information Publisher: Canadian Society Petroleum Geologists Received: 04 Jan Accepted: 20 Sep First Online: 09 Mar 2017 Online ISSN: 2368-0261 Print...