Notes
![]() ![]() Notes - notes.io |
From the extracted time constants, two glass transition temperatures Tg1 and Tg2 can be derived, showing a non-trivial concentration dependence for Tg2. Supplementary, we find a β-relaxation. The total relaxation strength Δε strongly deviates from ideal mixing, and therefore care has to be taken interpreting the corresponding Δεαi as representation of molecular populations.The Watson-Crick base pair proton transfer tautomers would be widely considered as a source of spontaneous mutations in DNA replication if not for their short lifetimes and thermodynamic instability. This work investigates the effects external electric fields have on the stability of the guanine-cytosine proton transfer tautomers within a realistic strand of aqueous DNA using a combination of ensemble-based classical molecular dynamics (MD) coupled to quantum mechanics/molecular mechanics (QM/MM). Performing an ensemble of calculations accounts for the stochastic aspects of the simulations while allowing for easier identification of systematic errors. The methodology applied in this work has previously been shown to estimate base pair proton transfer rate coefficients that are in good agreement with recent experimental data. A range of electric fields in the order of 104 to 109 V m-1 is investigated based on their real-life medicinal applications which include gene therapy and cancer treatments. The MD trajectories confirm that electric fields up to 1.00 × 109 V m-1 have a negligible influence on the structure of the base pairs within DNA. The QM/MM results show that the application of large external electric fields (1.00 × 109 V m-1) parallel to the hydrogen bonds increases the thermodynamic population of the tautomers by up to one order of magnitude; moreover, the lifetimes of the tautomers remain insignificant when compared to the timescale of DNA replication.In this study, we used mixtures of carboxylic acids and amines as solvents for the liquid-liquid extraction of copper salts with various anions from aqueous phase, and systematically varied the acid/amine ratio to determine its influence on extraction efficiency. The organic phases resulting from these extraction experiments were studied using small-angle X-ray scattering (SAXS), establishing a connection between the extraction process and the liquid structure. A relationship is found between the extent of extraction for the metal salt, the strength of the Hofmeister effect of the anions of the salt, and the characteristic lengthscale of the observed liquid nanoscale structure before and after extraction.The reactions of SbH3 with one or two equivalents of (Dipp2NacNac)Ga (Dipp2NacNac = HCC(Me)N(Dipp)2; Dipp = 2,6-iPr2C6H3) yield the primary and secondary stibanes (Dipp2NacNac)GaH(SbH2) (3) and (Dipp2NacNac)GaH2(SbH) (5). Their lighter homologs were obtained from the analogous reactions with phosphine and arsine. All compounds were characterized using heteronuclear NMR-spectroscopy, IR-spectroscopy and single-crystal X-ray diffraction.Photoelectrochemical (PEC) splitting of water to make hydrogen is a promising clean-energy technology. The oxygen evolution reaction (OER) largely determines the energy efficiency in PEC water-splitting. Hematite, which is a cheap and sustainable semiconductor material with excellent chemical properties, a favourable band gap (2.1 eV) and composed of earth abundant elements is a suitable model photoanode material for studying OER. To understand the design of energy efficient anodes, it is highly desirable to have mechanistic insight into OER at an atomistic level which can be directly connected to experimentally measured quantities. We present a multiscale computational model of OER which connects the thermodynamics and kinetics of elementary charge transfer reactions in OER to kinetics of OER at laboratory length and time scales. We couple density functional theory (DFT) and DFT based molecular dynamics (DFT-MD) simulations with solvent effects at an atomistic level with kinetic Monte Carlo (kMC) simulations at a coarse-grained level in our multiscale model. The time and applied bias potential dependent surface coverage, which are experimentally not known, and the O2 evolution rate during OER at the hematite-water interface are calculated by the multiscale model. Furthermore, the multiscale model demonstrates the effect of explicitly modelling the interaction of water with the electrode surface via direct adsorption.We reply to the comment on our recent paper entitled "Impact of water on the BrO + HO2 gas-phase reaction mechanism, kinetics and products" by Chow et al. In their comment, the authors raised the differences between our results and their results in an earlier paper (R. Chow, D. K. W. Mok, E. P. F. Lee and J. M. Dyke, Phys. Chem. Chem. Phys., 2016, 18, 30554-30569), in terms of kinetics and potential energy surface, and they attributed these differences to the use of a small integration grid size and closed-shell wavefunctions for geometry optimizations in our study. Indeed, in our original manuscript, we did not ensure the proper use of UHF wavefunctions for singlet states, which led the singlet states to be treated with restricted M06-2X wavefunctions during optimizations. Furthermore, the default integration grid was used. CDK inhibitor New geometry optimizations have been performed where reactant complexes on the singlet surface were treated in their open-shell singlet states (ensured by using unrestricted-spin wave-functions) and using very tight convergence criteria, and new reaction rate constants have been calculated based on new energy barriers. No barrierless hydrogen abstraction reactions were observed as reported in our previous results and, consequently, the outer rate coefficient in the two-transition state approach (given by eqn (5) in Tsona et al., 2019) was determined by the collision theory. Overall rate constants exhibit a negative temperature dependency in the 200-400 K range. Despite the changes on the reaction energies and kinetics due to wrong UHF wavefunctions, our main conclusion that water has no net effect on the BrO + HO2 → BrOH + O2 reaction is still valid.
My Website: https://www.selleckchem.com/CDK.html
![]() |
Notes is a web-based application for online taking notes. You can take your notes and share with others people. If you like taking long notes, notes.io is designed for you. To date, over 8,000,000,000+ notes created and continuing...
With notes.io;
- * You can take a note from anywhere and any device with internet connection.
- * You can share the notes in social platforms (YouTube, Facebook, Twitter, instagram etc.).
- * You can quickly share your contents without website, blog and e-mail.
- * You don't need to create any Account to share a note. As you wish you can use quick, easy and best shortened notes with sms, websites, e-mail, or messaging services (WhatsApp, iMessage, Telegram, Signal).
- * Notes.io has fabulous infrastructure design for a short link and allows you to share the note as an easy and understandable link.
Fast: Notes.io is built for speed and performance. You can take a notes quickly and browse your archive.
Easy: Notes.io doesn’t require installation. Just write and share note!
Short: Notes.io’s url just 8 character. You’ll get shorten link of your note when you want to share. (Ex: notes.io/q )
Free: Notes.io works for 14 years and has been free since the day it was started.
You immediately create your first note and start sharing with the ones you wish. If you want to contact us, you can use the following communication channels;
Email: [email protected]
Twitter: http://twitter.com/notesio
Instagram: http://instagram.com/notes.io
Facebook: http://facebook.com/notesio
Regards;
Notes.io Team