Autowave Chemical Transformations of Highly Exothermic Mixture Based on Niobium Oxide with Aluminum

2017 ◽  
Keyword(s):  
Niobium Oxide ◽  
Chemical Transformations ◽  
Exothermic Mixture

Autowave chemical transformations of highly exothermic mixtures based on niobium oxide with aluminum

2017 ◽  
Vol 53 (5) ◽  
pp. 580-584
Author(s):  
V. I. Yukhvid ◽  
D. E. Andreev ◽  
V. N. Sanin ◽  
N. V. Sachkova
Keyword(s):  
Niobium Oxide ◽  
Chemical Transformations

Niobium Oxide as Catalyst for the Pyrolysis of Polypropylene and Polyethylene Plastic Waste

2016 ◽  
Vol 10 (4) ◽  
pp. 465-472 ◽  
Author(s):  
Debora Almeida ◽  
◽  
Maria de Fatima Marques ◽  
Keyword(s):  
Thermogravimetric Analysis ◽  
Niobium Oxide ◽  
Plastic Waste

In the present work, the pyrolysis of polypropylene and polyethylene was evaluated with and without the addition of niobium oxide as catalyst by means of thermogravimetric analysis and experiments in a glass reactor. The results revealed that niobium oxide performed well in the pyrolysis of both polypropylene and polyethylene separately. For the mixture of polypropylene with polyethylene, the catalyst reduced the pyrolysis time.

BODIPY Fluorophores for Membrane Potential Imaging

2019 ◽  
Author(s):  
Jenna Franke ◽  
Benjamin Raliski ◽  
Steven Boggess ◽  
Divya Natesan ◽  
Evan Koretsky ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Water Solubility ◽  
Water Soluble ◽  
Voltage Sensitivity ◽  
Chemical Transformations ◽  
Direct Modification ◽  
Biological Compatibility ◽  
Meso Position ◽  
Ionizable Groups ◽  
Boron Center

Fluorophores based on the BODIPY scaffold are prized for their tunable excitation and emission profiles, mild syntheses, and biological compatibility. Improving the water-solubility of BODIPY dyes remains an outstanding challenge. The development of water-soluble BODIPY dyes usually involves direct modification of the BODIPY fluorophore core with ionizable groups or substitution at the boron center. While these strategies are effective for the generation of water-soluble fluorophores, they are challenging to implement when developing BODIPY-based indicators: direct modification of BODIPY core can disrupt the electronics of the dye, complicating the design of functional indicators; and substitution at the boron center often renders the resultant BODIPY incompatible with the chemical transformations required to generate fluorescent sensors. In this study, we show that BODIPYs bearing a sulfonated aromatic group at the meso position provide a general solution for water-soluble BODIPYs. We outline the route to a suite of 5 new sulfonated BODIPYs with 2,6-disubstitution patterns spanning a range of electron-donating and -withdrawing propensities. To highlight the utility of these new, sulfonated BODIPYs, we further functionalize them to access 13 new, BODIPY-based voltage-sensitive fluorophores. The most sensitive of these BODIPY VF dyes displays a 48% ΔF/F per 100 mV in mammalian cells. Two additional BODIPY VFs show good voltage sensitivity (≥24% ΔF/F) and excellent brightness in cells. These compounds can report on action potential dynamics in both mammalian neurons and human stem cell-derived cardiomyocytes. Accessing a range of substituents in the context of a water soluble BODIPY fluorophore provides opportunities to tune the electronic properties of water-soluble BODIPY dyes for functional indicators.

Strongly Coupled Redox-Linked Conformational Switching at the Active Site of the Non-Heme Iron-Dependent Dioxygenase, TauD

2019 ◽  
Author(s):  
Christopher John ◽  
Greg M. Swain ◽  
Robert P. Hausinger ◽  
Denis A. Proshlyakov
Keyword(s):  
Active Site ◽  
Structural Model ◽  
Heme Iron ◽  
Chemical Transformations ◽  
Experimental Conditions ◽  
Strongly Coupled ◽  
Non Heme Iron ◽  
Reversible Redox ◽  
Wide Range ◽  
Complex Structural

2-Oxoglutarate (2OG)-dependent dioxygenases catalyze C-H activation while performing a wide range of chemical transformations. In contrast to their heme analogues, non-heme iron centers afford greater structural flexibility with important implications for their diverse catalytic mechanisms. We characterize an <i>in situ</i> structural model of the putative transient ferric intermediate of 2OG:taurine dioxygenase (TauD) by using a combination of spectroelectrochemical and semi-empirical computational methods, demonstrating that the Fe (III/II) transition involves a substantial, fully reversible, redox-linked conformational change at the active site. This rearrangement alters the apparent redox potential of the active site between -127 mV for reduction of the ferric state and 171 mV for oxidation of the ferrous state of the 2OG-Fe-TauD complex. Structural perturbations exhibit limited sensitivity to mediator concentrations and potential pulse duration. Similar changes were observed in the Fe-TauD and taurine-2OG-Fe-TauD complexes, thus attributing the reorganization to the protein moiety rather than the cosubstrates. Redox difference infrared spectra indicate a reorganization of the protein backbone in addition to the involvement of carboxylate and histidine ligands. Quantitative modeling of the transient redox response using two alternative reaction schemes across a variety of experimental conditions strongly supports the proposal for intrinsic protein reorganization as the origin of the experimental observations.

Production of Biodiesel by a Two-Step Niobium Oxide Catalyzed Hydrolysis and Esterification

2010 ◽  
Vol 7 (7) ◽  
pp. 571-578 ◽  
Author(s):  
Layla L.L. Rocha ◽  
Andre L.D. Ramos ◽  
Nelson Roberto Antoniosi Filho ◽  
Nelson C. Furtado ◽  
Carlton A. Taft ◽  
...  
Keyword(s):  
Niobium Oxide

An Overview on Steroids and Microwave Energy in Multi-Component Reactions towards the Synthesis of Novel Hybrid Molecules

2020 ◽  
Vol 17 (8) ◽  
pp. 594-609
Author(s):  
Preetismita Borah ◽  
Vhatkar Dattatraya Shivling ◽  
Bimal Krishna Banik ◽  
Biswa Mohan Sahoo
Keyword(s):  
Energy Consumption ◽  
Multicomponent Reactions ◽  
Biological Activities ◽  
Vital Role ◽  
Microwave Energy ◽  
Biosynthetic Pathways ◽  
Chemical Transformations ◽  
Carbon Carbon Bond ◽  
Hybrid Molecules ◽  
Time Required

In recent years, hybrid systems are gaining considerable attention owing to their various biological applications in drug development. Generally, hybrid molecules are constructed from different molecular entities to generate a new functional molecule with improved biological activities. There already exist a large number of naturally occurring hybrid molecules based on both non-steroid and steroid frameworks synthesized by nature through mixed biosynthetic pathways such as, a) integration of the different biosynthetic pathways or b) Carbon- Carbon bond formation between different components derived through different biosynthetic pathways. Multicomponent reactions are a great way to generate efficient libraries of hybrid compounds with high diversity. Throughout the scientific history, the most common factors developing technologies are less energy consumption and avoiding the use of hazardous reagents. In this case, microwave energy plays a vital role in chemical transformations since it involves two very essential criteria of synthesis, minimizing energy consumption required for heating and time required for the reaction. This review summarizes the use of microwave energy in the synthesis of steroidal and non-steroidal hybrid molecules and the use of multicomponent reactions.

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