Search results for "Organic Chemical"
showing 10 items of 733 documents
Hydration dependence of myoglobin dynamics studied with elastic neutron scattering, differential scanning calorimetry and broadband dielectric spectr…
2014
In this work we present a thorough investigation of the hydration dependence of myoglobin dynamics. The study is performed on D2O-hydrated protein powders in the hydration range 0<h<0.5 (h≡gr[D2O]/gr[protein]) and in the temperature range 20-300K. The protein equilibrium fluctuations are investigated with Elastic Neutron Scattering using the spectrometer IN13 at ILL (Grenoble), while the relaxations of the protein + hydration water system are investigated with Broadband Dielectric Spectroscopy; finally, Differential Scanning Calorimetry is used to obtain a thermodynamic description of the system. The effect of increasing hydration is to speed up the relaxations of the myoglobin + hydration …
Determination of the Absolute Density of Fe3+ and Ni2+ Ions in Langmuir-Blodgett Films
1996
By means of the Langmuir–Blodgett (LB) technique, mono- and multilayers of Ni2+ and Fe3+ containing fatty acid salts are transferred onto silicon wafers. After thermal treatment, oxidic layers can be produced. The absolute amounts of Fe3+ and Ni2+ ions per monolayer of LB film were measured and calculated by three different methods. In the case of nickel, the amount expected from theory and preparation conditions was obtained experimentally. In contrast, about twice the number of Fe3+ ions as expected is transferred. An explanation can be given by the presence of hydroxide groups bound to iron. The mean film thickness of the oxidic layers after thermal treatment was estimated where the thic…
Chemically mediated sexual isolation between Zimbabwean endemic and cosmopolitan populations of Drosophila melanogaster
2010
Chemically mediated sexual isolation between Zimbabwean endemic and cosmopolitan populations of [i]Drosophila melanogaster[/i]. ISCE 26. annual meeting
Covalent Organic Frameworks for the detection of CO
2021
International audience; Every year in the world, carbon monoxide (CO) is responsible for thousands of intoxications and hundreds of deaths. The detection (CO) at few ppm levels is thus a critical point for the control of the air quality. Corrole belongs to the family of porphyrinoids which is largely used for sensing applications [1]. We have shown that cobalt metallocorroles are able to bind carbon monoxide in the axial position with a high affinity even in the presence of nitrogen and dioxygen, the two main components of the atmosphere [2]. We have recently prepared sensing devices for low CO detection level (sub-ppm) using cobalt corroles deposited as films on a Surface Acoustic Wave dev…
The Use of Ca- and Mg-Rich Fly Ash as a Chemical Precipitant in the Simultaneous Removal of Nitrogen and Phosphorus - Recycling and Reuse
2019
The European Union’s circular economy strategy aims to increase the recycling and re-use of products and waste materials. According to the strategy, the use of industry waste material should be more effective. A chemical precipitation method to simultaneously remove phosphorus and nitrogen from synthetic (NH4)2HPO4 solution and the liquid phase of anaerobic digestate using fly ash as a precipitant was tested. Fly ash is a waste material formed in the power plant process. It mainly contains calcium oxide (CaO) and magnesium oxide (MgO). Saturated precipitant solution was prepared from fly ash, which was added in small proportions to (NH4)2HPO4 solution during the experiment. Fly ash’s effect…
MONENSIN ENHANCES DIGOXIN-INDUCED ARRHYTHMIAS IN GUINEA-PIGS
1993
Effects of pretreatment with monensin (150 ug/kg), atenolol (0.3 mg/kg), atenolol plus monensin, verapamil (0.38 mg/kg), verapamil plus monensin, glibenclamide(0.38 mg/kg) and glibenclamide plus monensin on the dose of digoxin required to induce premature ventricular contractions (PVCS) in anaesthetized guinea-pigs were studied. Monensin reduced while atenolol increased the dose of digoxin required to produce PVCS. Atenolol plus monensin increased the dose of digoxin required to produce PVCS in presence of monensin alone. Verapamil reduces the arrhythmogenic effect of monensin on digoxin. Glibenclamide antagonises the effect of monensin on digoxin induced PVCS. From the present data it coul…
3,4′,5,5′-Tetramethoxy-2′-methylbiphenyl-4-ol
2019
The asymmetric unit of the title compound, C17H20O5, contains two independent molecules, A and B, with similar geometries [dihedral angles between the phenyl rings = 56.19 (8) and 54.98 (7)°, respectively]. Intramolecular O—H...O hydrogen bonds occur in both molecules. In the crystal, the A molecules form [1\overline{1}0] chains linked by O—H...O hydrogen bonds from the hydroxyl group to one of the methoxy O atoms. The B molecules form O—H...O hydrogen bonds to the hydroxyl O atoms of the A molecules and thus act as fixed spacers between the chains of molecule A. Some weak C—H...O contacts are also present.
Predicting the activity of single isolated Lewis acid sites in solid catalysts.
2006
An experimental study of the activity of Ti-, Zr- and Sn-beta catalysts in different types of oxidation reactions is combined with a quantum-chemical analysis of the electronic properties of the active sites and the adsorbed reactants. The differences observed in the catalytic behaviour of the three materials are explained in terms of the molecular orbital distribution of each system. The intrinsic Lewis acid strength of the isolated active site, the degree of back-donation from the catalyst to the empty orbitals of the organic reactant and the net atomic charges on selected atoms are proposed as predictors of reactivity.
Globins and hypoxia adaptation in the goldfish, Carassius auratus
2008
Goldfish (Carassius auratus) may survive in aquatic environments with low oxygen partial pressures. We investigated the contribution of respiratory proteins to hypoxia tolerance in C. auratus. We determined the complete coding sequence of hemoglobin α and β and myoglobin, as well as partial cDNAs from neuroglobin and cytoglobin. Like the common carp (Cyprinus carpio), C. auratus possesses two paralogous myoglobin genes that duplicated within the cyprinid lineage. Myoglobin is also expressed in nonmuscle tissues. By means of quantitative real-time RT-PCR, we determined the changes in mRNA levels of hemoglobin, myoglobin, neuroglobin and cytoglobin in goldfish exposed to prolonged hypoxia (48…
Organic solvent-soluble contents of nickel and cobalt in some algae
1990
In pursuit of our work on metal contents of lipid fractions isolated from plant material, we now show by means of highly sensitive analytical methods that nickel and cobalt are also present in organic extracts of algae in detectable amounts