Re-Programming Hydrogel Properties using a Fuel-driven Reaction Cycle

2019 ◽  
Author(s):  
Nishant Singh ◽  
Bruno Lainer ◽  
Georges Formon ◽  
Serena De Piccoli ◽  
Thomas Hermans
Keyword(s):  
Methionine Oxidation ◽  
Guanosine Triphosphate ◽  
Control Reaction ◽  
Reaction Cycle ◽  
Materials Properties ◽  
Assembly Kinetics ◽  
Control Assembly ◽  
Indispensable Tool ◽  
Reaction Cycles ◽  
Non Equilibrium

Nature uses catalysis as an indispensable tool to control assembly and reaction cycles in vital non-equilibrium supramolecular processes. For instance, enzymatic methionine oxidation regulates actin (dis)assembly, and catalytic guanosine triphosphate hydrolysis is found in tubulin (dis)assembly. Here we present a completely artificial reaction cycle which is driven by a chemical fuel that is catalytically obtained from a ‘pre-fuel’. The reaction cycle controls the disassembly and re-assembly of a hydrogel, where the rate of pre-fuel turnover dictates the morphology as well as the mechanical properties. By adding additional fresh aliquots of fuel and removing waste, the hydrogels can be re-programmed time after time. Overall, we show how catalysis can control fuel generation to control reaction / assembly kinetics and materials properties in life-like non-equilibrium systems.

scholarly journals Re-Programming Hydrogel Properties using a Fuel-driven Reaction Cycle

2019 ◽  
Author(s):  
Nishant Singh ◽  
Bruno Lainer ◽  
Georges Formon ◽  
Serena De Piccoli ◽  
Thomas Hermans
Keyword(s):  
Methionine Oxidation ◽  
Guanosine Triphosphate ◽  
Control Reaction ◽  
Reaction Cycle ◽  
Materials Properties ◽  
Assembly Kinetics ◽  
Control Assembly ◽  
Indispensable Tool ◽  
Reaction Cycles ◽  
Non Equilibrium

Nature uses catalysis as an indispensable tool to control assembly and reaction cycles in vital non-equilibrium supramolecular processes. For instance, enzymatic methionine oxidation regulates actin (dis)assembly, and catalytic guanosine triphosphate hydrolysis is found in tubulin (dis)assembly. Here we present a completely artificial reaction cycle which is driven by a chemical fuel that is catalytically obtained from a ‘pre-fuel’. The reaction cycle controls the disassembly and re-assembly of a hydrogel, where the rate of pre-fuel turnover dictates the morphology as well as the mechanical properties. By adding additional fresh aliquots of fuel and removing waste, the hydrogels can be re-programmed time after time. Overall, we show how catalysis can control fuel generation to control reaction / assembly kinetics and materials properties in life-like non-equilibrium systems.

Re-Programming Hydrogel Properties using a Fuel-driven Reaction Cycle

2019 ◽  
Author(s):  
Nishant Singh ◽  
Bruno Lainer ◽  
Georges Formon ◽  
Serena De Piccoli ◽  
Thomas Hermans
Keyword(s):  
Methionine Oxidation ◽  
Guanosine Triphosphate ◽  
Control Reaction ◽  
Reaction Cycle ◽  
Materials Properties ◽  
Assembly Kinetics ◽  
Control Assembly ◽  
Indispensable Tool ◽  
Reaction Cycles ◽  
Non Equilibrium

Nature uses catalysis as an indispensable tool to control assembly and reaction cycles in vital non-equilibrium supramolecular processes. For instance, enzymatic methionine oxidation regulates actin (dis)assembly, and catalytic guanosine triphosphate hydrolysis is found in tubulin (dis)assembly. Here we present a completely artificial reaction cycle which is driven by a chemical fuel that is catalytically obtained from a ‘pre-fuel’. The reaction cycle controls the disassembly and re-assembly of a hydrogel, where the rate of pre-fuel turnover dictates the morphology as well as the mechanical properties. By adding additional fresh aliquots of fuel and removing waste, the hydrogels can be re-programmed time after time. Overall, we show how catalysis can control fuel generation to control reaction / assembly kinetics and materials properties in life-like non-equilibrium systems.

scholarly journals Parasitic Behavior in Competing Chemically Fueled Reaction Cycles

2021 ◽  
Author(s):  
Patrick S. Schwarz ◽  
Sudarshana Laha ◽  
Jacqueline Janssen ◽  
Tabea Huss ◽  
Job Boekhoven ◽  
...  
Keyword(s):  
Dynamic Behavior ◽  
Model Systems ◽  
Reaction Networks ◽  
Reaction Cycles ◽  
Non Equilibrium

Non-equilibrium, fuel-driven reaction cycles serve as model systems of the intricate reaction networks of life. Rich and dynamic behavior is observed when reaction cycles regulate assembly processes, such as phase...

scholarly journals Stability of a Nonequilibrium Biochemical Cycle Revealed by Single-Molecule Spectroscopy

2021 ◽  
Author(s):  
Saurabh Talele ◽  
John T King
Keyword(s):  
Entropy Production ◽  
Single Molecule ◽  
Nonequilibrium Dynamics ◽  
Single Molecule Spectroscopy ◽  
Reaction Cycle ◽  
Central Interest ◽  
Thermodynamic Driving Force ◽  
Reaction Cycles ◽  
Thermal Stability Of

Biological machinery relies on nonequilibrium dynamics to maintain stable directional fluxes through complex reaction cycles. In stabilizing the reaction cycle, the role of microscopic irreversibility of elementary transitions, and the accompanying entropy production, is of central interest. Here, we use multidimensional single-molecule spectroscopy to demonstrate that the reaction cycle of bacteriorhodopsin is coupled through both reversible and irreversible transitions, with directionality of trans-membrane H+ transport being ensured by the entropy production of irreversible transitions. We observe that thermal destabilization of the process is the result of diminishing thermodynamic driving force for irreversible transitions, leading to an exponentially increasing variance of flux through the transitions. We show that the thermal stability of the reaction cycle can be predicted from the Gibbs-Helmholtz relation.

scholarly journals Space and Time Crystal Engineering in Developing Futuristic Chemical Technology

2021 ◽  
Vol 5 (4) ◽  
pp. 67
Author(s):  
Pathik Sahoo ◽  
Subrata Ghosh
Keyword(s):  
Crystal Engineering ◽  
Chemical Engineering ◽  
Chemical System ◽  
Smart Devices ◽  
Active Centers ◽  
Reaction Cycle ◽  
Time Space ◽  
Catalytically Active ◽  
Reaction Cycles ◽  
Competitive Products

In the coming years, multipurpose catalysts for delivering different products under the same chemical condition will be required for developing smart devices for industrial or household use. In order to design such multipurpose devices with two or more specific roles, we need to incorporate a few independent but externally controllable catalytically active centers. Through space crystal engineering, such an externally controllable multipurpose MOF-based photocatalyst could be designed. In a chemical system, a few mutually independent secondary reaction cycles nested within the principal reaction cycle can be activated externally to yield different competitive products. Each reaction cycle can be converted into a time crystal, where the time consuming each reaction step could be converted as an event and all the reaction steps or events could be connected by a circle to build a time crystal. For fractal reaction cycles, a time polycrystal can be generated. By activating a certain fractal event based nested time crystal branch, we can select one of the desired competitive products according to our needs. This viewpoint intends to bring together the ideas of (spatial) crystal engineering and time crystal engineering in order to make use of the time–space arrangement in reaction–catalysis systems and introduce new aspects to futuristic chemical engineering technology.

scholarly journals Non‐equilibrium large‐scale membrane transformations driven by MinDE biochemical reaction cycles

2020 ◽  
Author(s):  
MEIFANG FU ◽  
Henri G. Franquelim ◽  
Simon Kretschmer ◽  
Petra Schwille
Keyword(s):  
Large Scale ◽  
Biochemical Reaction ◽  
Reaction Cycles ◽  
Non Equilibrium

Applications of Transmission Electron Microscopy in the Characterization of Metal Machinability

1968 ◽  
Vol 26 ◽  
pp. 442-443 ◽  
Author(s):  
L.E. Murr ◽  
A.B. Draper
Keyword(s):  
Electron Microscopy ◽  
State Physics ◽  
Test Material ◽  
Milling Machine ◽  
Rotary Table ◽  
Solid State Physics ◽  
Materials Properties ◽  
Transmission Electron ◽  
Selection Of

The industrial characterization of the machinability of metals and alloys has always been a very arbitrarily defined property, subject to the selection of various reference or test materials; and the adoption of rather naive and misleading interpretations and standards. However, it seems reasonable to assume that with the present state of knowledge of materials properties, and the current theories of solid state physics, more basic guidelines for machinability characterization might be established on the basis of the residual machined microstructures. This approach was originally pursued by Draper; and our presentation here will simply reflect an exposition and extension of this research.The technique consists initially in the production of machined chips of a desired test material on a horizontal milling machine with the workpiece (specimen) mounted on a rotary table vice. A single cut of a specified depth is taken from the workpiece (0.25 in. wide) each at a new tool location.

Application of analytical electron microscopy to studies of equilibrium and non-equilibrium segregation in materials

1992 ◽  
Vol 50 (2) ◽  
pp. 1214-1215
Author(s):  
Edward A Kenik
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Extended Defects ◽  
Probe Diameter ◽  
Specimen Holder ◽  
Analytical Electron ◽  
Scanning Transmission ◽  
Solute Atoms ◽  
Equilibrium Segregation ◽  
Non Equilibrium

Segregation of solute atoms to grain boundaries, dislocations, and other extended defects can occur under thermal equilibrium or non-equilibrium conditions, such as quenching, irradiation, or precipitation. Generally, equilibrium segregation is narrow (near monolayer coverage at planar defects), whereas non-equilibrium segregation exhibits profiles of larger spatial extent, associated with diffusion of point defects or solute atoms. Analytical electron microscopy provides tools both to measure the segregation and to characterize the defect at which the segregation occurs. This is especially true of instruments that can achieve fine (<2 nm width), high current probes and as such, provide high spatial resolution analysis and characterization capability. Analysis was performed in a Philips EM400T/FEG operated in the scanning transmission mode with a probe diameter of <2 nm (FWTM). The instrument is equipped with EDAX 9100/70 energy dispersive X-ray spectrometry (EDXS) and Gatan 666 parallel detection electron energy loss spectrometry (PEELS) systems. A double-tilt, liquid-nitrogen-cooled specimen holder was employed for microanalysis in order to minimize contamination under the focussed spot.

Swallow Pattern Generator Reconfiguration of the Respiratory Neural Network

2009 ◽  
Vol 18 (1) ◽  
pp. 3-12
Author(s):  
Andrea Vovka ◽  
Paul W. Davenport ◽  
Karen Wheeler-Hegland ◽  
Kendall F. Morris ◽  
Christine M. Sapienza ◽  
...  
Keyword(s):  
Behavioral Control ◽  
Upper Airway ◽  
Pattern Generator ◽  
Breathing Patterns ◽  
Motor Patterns ◽  
Control Assembly ◽  
Pharyngeal Swallow ◽  
Laryngeal Vestibule ◽  
Lower Airways ◽  
Swallow Apnea

Abstract When the nasal and oral passages converge and a bolus enters the pharynx, it is critical that breathing and swallow motor patterns become integrated to allow safe passage of the bolus through the pharynx. Breathing patterns must be reconfigured to inhibit inspiration, and upper airway muscle activity must be recruited and reconfigured to close the glottis and laryngeal vestibule, invert the epiglottis, and ultimately protect the lower airways. Failure to close and protect the glottal opening to the lower airways, or loss of the integration and coordination of swallow and breathing, increases the risk of penetration or aspiration. A neural swallow central pattern generator (CPG) controls the pharyngeal swallow phase and is located in the medulla. We propose that this swallow CPG is functionally organized in a holarchical behavioral control assembly (BCA) and is recruited with pharyngeal swallow. The swallow BCA holon reconfigures the respiratory CPG to produce the stereotypical swallow breathing pattern, consisting of swallow apnea during swallowing followed by prolongation of expiration following swallow. The timing of swallow apnea and the duration of expiration is a function of the presence of the bolus in the pharynx, size of the bolus, bolus consistency, breath cycle, ventilatory state and disease.

Sign in / Sign up

Export Citation Format

Share Document