scholarly journals 17O-EPR determination of the structure and dynamics of copper single-metal sites in zeolites

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Paolo Cleto Bruzzese ◽  
Enrico Salvadori ◽  
Stefan Jäger ◽  
Martin Hartmann ◽  
Bartolomeo Civalleri ◽  
...  
Keyword(s):  
Copper Ions ◽  
Water Pressure ◽  
Open Shell ◽  
Isotopic Labelling ◽  
Zeolite Framework ◽  
Metal Framework ◽  
Versatile Tool ◽  
Dft Modelling ◽  
Reversible Transfer

AbstractThe bonding of copper ions to lattice oxygens dictates the activity and selectivity of copper exchanged zeolites. By 17O isotopic labelling of the zeolite framework, in conjunction with advanced EPR methodologies and DFT modelling, we determine the local structure of single site CuII species, we quantify the covalency of the metal-framework bond and we assess how this scenario is modified by the presence of solvating H216O or H217O molecules. This enables to follow the migration of CuII species as a function of hydration conditions, providing evidence for a reversible transfer pathway within the zeolite cage as a function of the water pressure. The results presented in this paper establish 17O EPR as a versatile tool for characterizing metal-oxide interactions in open-shell systems.

scholarly journals Real-Time PCR as a Versatile Tool for Investigating the Susceptibility of Human Herpesvirus 6 to Antiviral Agents

2003 ◽  
Vol 47 (9) ◽  
pp. 3021-3024 ◽  
Author(s):  
Muriel Macé ◽  
Chaysavanh Manichanh ◽  
Pascale Bonnafous ◽  
Stéphanie Précigout ◽  
David Boutolleau ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Antiviral Agents ◽  
Antiviral Drug ◽  
Human Herpesvirus ◽  
Drug Susceptibility ◽  
Human Herpesvirus 6 ◽  
Versatile Tool ◽  
Herpesvirus 6

ABSTRACT A quantitative real-time PCR assay was developed for the determination of antiviral drug susceptibility and growth kinetics of human herpesvirus 6. The susceptibility and fitness of a sensitive strain, HST, and its ganciclovir-resistant derivative, GCVR1, were then characterized, leading us to conclude that the mutations of this latter virus did not alter its fitness significantly.

scholarly journals High-Resolution Single-Molecule FRET via DNA eXchange (FRET X)

2020 ◽  
Author(s):  
Mike Filius ◽  
Sung Hyun Kim ◽  
Ivo Severins ◽  
Chirlmin Joo
Keyword(s):  
Structural Analysis ◽  
High Resolution ◽  
Single Molecule ◽  
Single Object ◽  
Single Molecule Fret ◽  
Dna Strands ◽  
Versatile Tool ◽  
Fret Efficiency ◽  
Fret Pair

ABSTRACTSingle-molecule FRET is a versatile tool to study nucleic acids and proteins at the nanometer scale. However, currently, only a couple of FRET pairs can be reliably measured on a single object. The limited number of available FRET pair fluorophores and complicated data analysis makes it challenging to apply single-molecule FRET for structural analysis of biomolecules. Currently, only a couple of FRET pairs can be reliably measured on a single object. Here we present an approach that allows for the determination of multiple distances between FRET pairs in a single object. We use programmable, transient binding between short DNA strands to resolve the FRET efficiency of multiple fluorophore pairs. By allowing only a single FRET pair to be formed at a time, we can determine the FRET efficiency and pair distance with sub-nanometer resolution. We determine the distance between other pairs by sequentially exchanging DNA strands. We name this multiplexing approach FRET X for FRET via DNA eXchange. We envision that our FRET X technology will be a tool for the high-resolution structural analysis of biomolecules and other nano-structures.

scholarly journals Preconcentration of Copper with Solid Phase Extraction and its Determination by Flame Atomic Absorption Spectrometry

2008 ◽  
Vol 5 (4) ◽  
pp. 878-883 ◽  
Author(s):  
Ayob Parchehbaf Jadid ◽  
Habibollah Eskandari
Keyword(s):  
Detection Limit ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Copper Ions ◽  
Absorption Spectrometry ◽  
Phase Extraction ◽  
Flame Atomic Absorption ◽  
Low Levels ◽  
Determination Of Copper

A new method for the solid phase extraction (SPE) and determination of copper ions at low levels is presented. Extraction percent and the effects of some factors were evaluated. The detection limit was in the range of 2.26 µg·L-1. This procedure has been successfully applied to determination of copper in water samples.

Prior Determination of Flash Floods: Artificial Intelligence Based Predictive Analysis Using Modified Cuckoo Search

2020 ◽  
Vol 17 (2) ◽  
pp. 990-995
Author(s):  
Talha Ahmed Khan ◽  
Muhammad Alam ◽  
Kushsairy Kadir ◽  
Zeeshan Shahid ◽  
M. S. Mazliham
Keyword(s):  
Artificial Intelligence ◽  
Water Pressure ◽  
Cuckoo Search ◽  
Flash Floods ◽  
Rapid Identification ◽  
Predictive Analysis ◽  
Direct Observations ◽  
The Pacific ◽  
The Pacific Ocean

Flash floods are considered as the most intense hazard therefore rapid identification is needed. Tsunami also causes flash floods as it is commonly generated around the Pacific Ocean. Flash floods are also caused by the severely blocked streams in heavy rainfall. Floods have ended up so many lives more than the other natural hazards and also devastated precious belongings and infrastructures. Cattles have also been affected by the floods event. Floods devastate the construction and infrastructure like roads, bridges and buildings that comes in the vicinity of effected area by flood. Breakdown and overflow of dams may produce the deadly flash floods to the populated area and environs. Many strategies and methods have been followed to determine the flash floods on early basis so that evacuation announcements may be propagated. Numerous researches have been studied and carried out to accomplish this task. Development of dams and reservoirs have been given more significance. Artificial Intelligence based competent decision-making algorithms like Bayesian classifier, PSO, ANN, NNARX, SVM and GA have been applied to achieve more accuracy in predictive analysis. Direct observations from the sensors and data from the meteorological department have also been used for the predictive analysis of flash floods. Many yardstick parameters have been proposed in past researches to identify the flash floods vigorously like environmental CO2 levels, precipitation velocity, wind speed, upstream level, height of the water, pressure, temperature and cloud to ground flashes. In this research papers a novel Artificial Intelligence based approach Modified Cuckoo Search (MCS) has been adopted to forecast the flash floods more rapidly and accurately. Obtained results in the MATLAB have proved that Modified cuckoo search with the combination of Artificial Neural Network worked better than the recent available methods. Results have also been validated by comparing the MLP-PSO.

Determination of Geometry Arrangement of Copper Ions in HKUST-1 by XAFS During a Prolonged Exposure to Air

2017 ◽  
Vol 121 (44) ◽  
pp. 24853-24860 ◽  
Author(s):  
Michela Todaro ◽  
Luisa Sciortino ◽  
Franco Mario Gelardi ◽  
Gianpiero Buscarino
Keyword(s):  
Prolonged Exposure ◽  
Copper Ions
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