Stationary inverted Lyman populations and free-free and bound-free emission of lower-energy state hydride ion formed by an exothermic catalytic reaction of atomic hydrogen and certain group I catalysts

Open Physics ◽  
2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Randell Mills ◽  
William Good ◽  
Peter Jansson ◽  
Jiliang He
Keyword(s):  
Catalytic Reaction ◽  
Atomic Hydrogen ◽  
Microwave Plasma ◽  
Energy State ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Hydrogen Atoms ◽  
Hydride Ion ◽  
Group I ◽  
Excess Power

AbstractRb+ to Rb2+ and 2K+ to K + K2+ each provide a reaction with a net enthalpy equal to the potential energy of atomic hydrogen. The presence of these gaseous ions with thermally dissociated hydrogen formed a plasma having strong VUV emission with a stationary inverted Lyman population. Significant Balmer α line broadening of 18 and 9 eV was observed from a rt-plasma of hydrogen with KNO3, and RbNO3, respectively, compared to 3 eV from a hydrogen microwave plasma. The reaction was exothermic since excess power of about 20 mW/cc was measured by Calvet calorimetry. We propose an energetic catalytic reaction involving a resonance energy transfer between hydrogen atoms and Rb+ or 2K+ to form a very stable novel hydride ion. Its predicted binding energy of 3.0471 eV with the fine structure was observed at 4071 Å, and its predicted bound-free hyperfine structure lines matched those observed for about 40 lines to within.01 percent. Characteristic emission from each catalyst was observed. This catalytic reaction may pump a CW HI laser.

scholarly journals AMPfret: synthetic nanosensor for cellular energy states

2020 ◽  
Vol 48 (1) ◽  
pp. 103-111
Author(s):  
Hannah Crocker ◽  
Martin Pelosse ◽  
Uwe Schlattner ◽  
Imre Berger
Keyword(s):  
Energy State ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Therapeutic Interventions ◽  
Cell Physiology ◽  
Dna Assembly ◽  
Cellular Energy ◽  
Energy States

Cellular energy is a cornerstone of metabolism and is crucial for human health and disease. Knowledge of the cellular energy states and the underlying regulatory mechanisms is therefore key to understanding cell physiology and to design therapeutic interventions. Cellular energy states are characterised by concentration ratios of adenylates, in particular ATP:ADP and ATP:AMP. We applied synthetic biology approaches to design, engineer and validate a genetically encoded nano-sensor for cellular energy state, AMPfret. It employs the naturally evolved energy sensing of eukaryotic cells provided by the AMP-activated protein kinase (AMPK). Our synthetic nano-sensor relies on fluorescence resonance energy transfer (FRET) to detect changes in ATP:ADP and ATP:AMP ratios both in vitro and in cells in vivo. Construction and iterative optimisation relied on ACEMBL, a parallelised DNA assembly and construct screening technology we developed, facilitated by a method we termed tandem recombineering (TR). Our approach allowed rapid testing of numerous permutations of the AMPfret sensor to identify the most sensitive construct, which we characterised and validated both in the test tube and within cells.

scholarly journals Removal of Covalent Heterogeneity Reveals Simple Folding Behavior for P4-P6 RNA

2011 ◽  
Vol 286 (22) ◽  
pp. 19872-19879 ◽  
Author(s):  
Max Greenfeld ◽  
Sergey V. Solomatin ◽  
Daniel Herschlag
Keyword(s):  
Single Molecule ◽  
Rna Folding ◽  
Tertiary Structure ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Molecular Heterogeneity ◽  
Group I ◽  
Single Molecule Studies ◽  
Covalent Modifications ◽  
Kinetic Effects

RNA folding landscapes have been described alternately as simple and as complex. The limited diversity of RNA residues and the ability of RNA to form stable secondary structures prior to adoption of a tertiary structure would appear to simplify folding relative to proteins. Nevertheless, there is considerable evidence for long-lived misfolded RNA states, and these observations have suggested rugged energy landscapes. Recently, single molecule fluorescence resonance energy transfer (smFRET) studies have exposed heterogeneity in many RNAs, consistent with deeply furrowed rugged landscapes. We turned to an RNA of intermediate complexity, the P4-P6 domain from the Tetrahymena group I intron, to address basic questions in RNA folding. P4-P6 exhibited long-lived heterogeneity in smFRET experiments, but the inability to observe exchange in the behavior of individual molecules led us to probe whether there was a non-conformational origin to this heterogeneity. We determined that routine protocols in RNA preparation and purification, including UV shadowing and heat annealing, cause covalent modifications that alter folding behavior. By taking measures to avoid these treatments and by purifying away damaged P4-P6 molecules, we obtained a population of P4-P6 that gave near-uniform behavior in single molecule studies. Thus, the folding landscape of P4-P6 lacks multiple deep furrows that would trap different P4-P6 molecules in different conformations and contrasts with the molecular heterogeneity that has been seen in many smFRET studies of structured RNAs. The simplicity of P4-P6 allowed us to reliably determine the thermodynamic and kinetic effects of metal ions on folding and to now begin to build more detailed models for RNA folding behavior.

Structural dynamics of P-type ATPase ion pumps

2019 ◽  
Vol 47 (5) ◽  
pp. 1247-1257 ◽  
Author(s):  
Mateusz Dyla ◽  
Sara Basse Hansen ◽  
Poul Nissen ◽  
Magnus Kjaergaard
Keyword(s):  
Structural Dynamics ◽  
Single Molecule ◽  
New Technologies ◽  
Atp Hydrolysis ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Time Resolved ◽  
Dynamics Simulations ◽  
Types Of Information ◽  
P Type

Abstract P-type ATPases transport ions across biological membranes against concentration gradients and are essential for all cells. They use the energy from ATP hydrolysis to propel large intramolecular movements, which drive vectorial transport of ions. Tight coordination of the motions of the pump is required to couple the two spatially distant processes of ion binding and ATP hydrolysis. Here, we review our current understanding of the structural dynamics of P-type ATPases, focusing primarily on Ca2+ pumps. We integrate different types of information that report on structural dynamics, primarily time-resolved fluorescence experiments including single-molecule Förster resonance energy transfer and molecular dynamics simulations, and interpret them in the framework provided by the numerous crystal structures of sarco/endoplasmic reticulum Ca2+-ATPase. We discuss the challenges in characterizing the dynamics of membrane pumps, and the likely impact of new technologies on the field.

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