scholarly journals Setting an Upper Limit on the Myoglobin Iron(IV)Hydroxide pKa: Insight into Axial Ligand Tuning in Heme Protein Catalysis

2014 ◽  
Vol 136 (25) ◽  
pp. 9124-9131 ◽  
Author(s):  
Timothy H. Yosca ◽  
Rachel K. Behan ◽  
Courtney M. Krest ◽  
Elizabeth L. Onderko ◽  
Matthew C. Langston ◽  
...  
Keyword(s):  
Heme Protein ◽  
Axial Ligand ◽  
Upper Limit ◽  
Insight Into ◽  
Protein Catalysis

scholarly journals Compressive strength of comet 67P/Churyumov-Gerasimenko derived from Philae surface contacts

2019 ◽  
Vol 630 ◽  
pp. A2 ◽  
Author(s):  
P. Heinisch ◽  
H.-U. Auster ◽  
B. Gundlach ◽  
J. Blum ◽  
C. Güttler ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Surface Material ◽  
Laboratory Measurements ◽  
Camera System ◽  
Upper Limit ◽  
Rosetta Mission ◽  
Ballistic Trajectory ◽  
Comet 67P ◽  
Insight Into ◽  
Impact Probe

Context. The landing and rebound of the Philae lander, which was part of the ESA Rosetta mission, enabled us to study the mechanical properties of the surface of comet 67P/Churyumov-Gerasimenko, because we could use Philae as an impact probe. Aims. The aim is to approximate the descent and rebound trajectory of the Philae lander and use this information to derive the compressive strength of the surface material from the different surface contacts and scratches created during the final touchdown. Combined with laboratory measurements, this can give an insight into what comets are made of and how they formed. Methods. We combined observations from the ROMAP magnetometer on board Philae with observations made by the Rosetta spacecraft, particularly by the OSIRIS camera system and the RPC-MAG magnetometer. Additionally, ballistic trajectory and collision modeling was performed. These results are placed in context using laboratory measurements of the compressibility of different materials. Results. It was possible to reconstruct possible trajectories of Philae and determine that a pressure of ~100 Pa is enough to compress the surface material up to a depth of ~20 cm. Considering all errors, the derived compressive strength shows little dependence on location, with an overall upper limit for the surface compressive strength of ~800 Pa.

An Insight into the Mechanism of the Axial Ligand Exchange Reaction in Boron Subphthalocyanine Macrocycles

2014 ◽  
Vol 136 (40) ◽  
pp. 14289-14298 ◽  
Author(s):  
Julia Guilleme ◽  
Lara Martínez-Fernández ◽  
David González-Rodríguez ◽  
Inés Corral ◽  
Manuel Yáñez ◽  
...  
Keyword(s):  
Exchange Reaction ◽  
Ligand Exchange ◽  
Axial Ligand ◽  
Ligand Exchange Reaction ◽  
Boron Subphthalocyanine ◽  
Insight Into

Mechanistic insight into the increase in the upper limit of vulnerability for rapid pacing

Heart Rhythm ◽  
2005 ◽  
Vol 2 (5) ◽  
pp. S219
Author(s):  
Mary M. Maleckar ◽  
David W. Bourn ◽  
Blanca Rodriguez ◽  
Natalia A. Trayanova
Keyword(s):  
Upper Limit ◽  
Mechanistic Insight ◽  
Upper Limit Of Vulnerability ◽  
Rapid Pacing ◽  
Insight Into

scholarly journals Versatility in Corrinoid Salvaging and Remodeling Pathways Supports Corrinoid-Dependent Metabolism in Dehalococcoides mccartyi

2012 ◽  
Vol 78 (21) ◽  
pp. 7745-7752 ◽  
Author(s):  
Shan Yi ◽  
Erica C. Seth ◽  
Yu-Jie Men ◽  
Sally P. Stabler ◽  
Robert H. Allen ◽  
...  
Keyword(s):  
De Novo ◽  
Chlorinated Solvents ◽  
Axial Ligand ◽  
Content Type ◽  
Dehalococcoides Mccartyi ◽  
Axial Ligands ◽  
The Common ◽  
Enzyme Cofactors ◽  
Lower Ligand ◽  
Insight Into

ABSTRACTCorrinoids are cobalt-containing molecules that function as enzyme cofactors in a wide variety of organisms but are produced solely by a subset of prokaryotes. Specific corrinoids are identified by the structure of their axial ligands. The lower axial ligand of a corrinoid can be a benzimidazole, purine, or phenolic compound. Though it is known that many organisms obtain corrinoids from the environment, the variety of corrinoids that can serve as cofactors for any one organism is largely unstudied. Here, we examine the range of corrinoids that function as cofactors for corrinoid-dependent metabolism inDehalococcoides mccartyistrain 195.Dehalococcoidesbacteria play an important role in the bioremediation of chlorinated solvents in the environment because of their unique ability to convert the common groundwater contaminants perchloroethene and trichloroethene to the innocuous end product ethene. All isolatedD. mccartyistrains require exogenous corrinoids such as vitamin B12for growth. However, like many other corrinoid-dependent bacteria, none of the well-characterizedD. mccartyistrains has been shown to be capable of synthesizing corrinoidsde novo. In this study, we investigate the ability ofD. mccartyistrain 195 to use specific corrinoids, as well as its ability to modify imported corrinoids to a functional form. We show that strain 195 can use only specific corrinoids containing benzimidazole lower ligands but is capable of remodeling other corrinoids by lower ligand replacement when provided a functional benzimidazole base. This study of corrinoid utilization and modification byD. mccartyiprovides insight into the array of strategies that microorganisms employ in acquiring essential nutrients from the environment.

DFT insight into axial ligand effects on electronic structure and mechanistic reactivity of oxoiron(iv) porphyrin

2020 ◽  
Vol 22 (21) ◽  
pp. 12173-12179
Author(s):  
Zhifeng Ma ◽  
Naoki Nakatani ◽  
Hiroshi Fujii ◽  
Masahiko Hada
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Axial Ligand ◽  
Functional Theory ◽  
Ligand Effects ◽  
Insight Into

The nature of axial ligand effects is revealed by density functional theory calculations, the ability of axial ligand bound to iron is strong, and the reaction is more reactive.

scholarly journals The upper limit and lift force within inertial focusing in high aspect ratio curved microfluidics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Javier Cruz ◽  
Klas Hjort
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Lift Force ◽  
Complex Fluids ◽  
Scaling Law ◽  
Valuable Insight ◽  
High Quality ◽  
Inertial Focusing ◽  
Upper Limit ◽  
Insight Into

AbstractMicrofluidics exploiting the phenomenon of inertial focusing have attracted much attention in the last decade as they provide the means to facilitate the detection and analysis of rare particles of interest in complex fluids such as blood and natural water. Although many interesting applications have been demonstrated, the systems remain difficult to engineer. A recently presented line of the technology, inertial focusing in High Aspect Ratio Curved microfluidics, has the potential to change this and make the benefits of inertial focusing more accessible to the community. In this paper, with experimental evidence and fluid simulations, we provide the two necessary equations to design the systems and successfully focus the targets in a single, stable, and high-quality position. The experiments also revealed an interesting scaling law of the lift force, which we believe provides a valuable insight into the phenomenon of inertial focusing.

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