Search results for "dati"

Dioxomolybdenum(VI) and -Tungsten(VI) Amino Bisphenolates as Epoxidation Catalysts

2016

Low-cost metallate salts Na2MO4·2H2O (M = molybdenum, tungsten) react with a tridentate amine bisphenol bis(2-hydroxy-3-tert-butyl-5-methylbenzyl)methylamine (H2ONOtBu) under ambient conditions in acidic methanol solutions. The reactions lead to the formation of isostructural dioxo complexes [MO2(ONOtBu)(MeOH)]·MeOH in convenient yields. Spectral data as well as X-ray analyses reveal these complexes to be isostructural. Both compounds were tested as catalysts for epoxidation of olefins using cis-cyclooctene, cyclohexene, norbornene and styrene as substrates and tert-butyl hydroperoxide and hydrogen peroxide as oxidants. The molybdenum complex catalyses selectively the oxidation of cis-cyclo…

Black Queen Evolution and Trophic Interactions Determine Plasmid Survival after the Disruption of the Conjugation Network

2018

Bacterial antibiotic resistance is often a part of mobile genetic elements that move from one bacterium to another. By interfering with the horizontal movement and the maintenance of these elements, it is possible to remove the resistance from the population. Here, we show that a so-called plasmid-dependent bacteriophage causes the initially resistant bacterial population to become susceptible to antibiotics. However, this effect is efficiently countered when the system also contains a predator that feeds on bacteria. Moreover, when the environment contains antibiotics, the survival of resistance is dependent on the resistance mechanism. When bacteria can help their contemporaries to degrad…

Tracking mite trophic interactions by multiplex PCR

2020

Background A thorough knowledge of trophic webs in agroecosystems is essential to achieve successful biological pest control. Phytoseiid mites are the most efficient natural enemies of tetranychid mites, which include several important pests worldwide. Nevertheless, phytoseiids may feed on other food sources including other microarthropods, plants and even other phytoseiids (intraguild predation), which can interfere with biological control services. Molecular gut content analysis is a valuable tool for characterizing trophic interactions, mainly when working on microarthropods such as mites. We have designed new primers for Phytoseiidae, Tetranychidae and Thysanoptera identification and th…

Randomized Trial : D-Glyceric Acid Activates Mitochondrial Metabolism in 50–60-Year-Old Healthy Humans

2021

Background: Based on earlier studies, natural metabolite D-glyceric acid (DGA) does not seem to play any role in whole-body metabolism. Nevertheless, one ethanol oxidation-related rat study with controversial results raised our interest. According to preparatory studies for the regulatory approval of DGA, some highly conserved mechanism seems to subtly activate the cellular energy metabolism. Therefore, the present 25-days double-blind human study with placebo control was initiated. Purpose: The main target in the present study with 27 healthy 50–60-year-old human volunteers was to find out whether an “acute” 4-days and a longer 21-days exogenous DGA regimen caused moderate activation of th…

An experimental and theoretical study of a heptacoordinated tungsten(VI) complex of a noninnocent phenylenediamine bis(phenolate) ligand

2018

Abstract [W(N2O2)(HN2O2)] (H4N2O2 = N,N′-bis(3,5-di-tert-butyl-2-hydroxyphenyl)-1,2-phenylenediamine) with a noninnocent ligand was formed by reaction of the alkoxide precursor [W(eg)3] (eg = the 1,2-ethanediolate dianion) with two equivalents of ligand. The phenol groups on one of the ligands are completely deprotonated and the ligand coordinates in a tetradentate fashion, whereas the other ligand is tridentate with one phenol having an intact OH group. The molecular structure, magnetic measurements, EPR spectroscopy, and density functional theory calculations indicate that the complex is a stable radical with the odd electron situated on the tridentate amidophenoxide ligand. The formal ox…

On the mechanism of imine elimination from Fischer tungsten carbene complexes

2016

(Aminoferrocenyl)(ferrocenyl)carbene(pentacarbonyl)tungsten(0) (CO)5W=C(NHFc)Fc (W(CO)5(E-2)) is synthesized by nucleophilic substitution of the ethoxy group of (CO)5W=C(OEt)Fc (M(CO)5(1Et)) by ferrocenyl amide Fc-NH– (Fc = ferrocenyl). W(CO)5(E-2) thermally and photochemically eliminates bulky E-1,2-diferrocenylimine (E-3) via a formal 1,2-H shift from the N to the carbene C atom. Kinetic and mechanistic studies to the formation of imine E-3 are performed by NMR, IR and UV–vis spectroscopy and liquid injection field desorption ionization (LIFDI) mass spectrometry as well as by trapping experiments for low-coordinate tungsten complexes with triphenylphosphane. W(CO)5(E-2) decays thermally i…

I cordati invertebrati: tunicati e cefalocordati

2010

Electrooxidation of diesel fuel in alkaline electrolyte

2016

In recent decades the demand of energy has increased significantly.Providing more and more energy is an essential task of today’s energetic industry. In the last few years, addition to traditional methods of energy production, alternative energy sources have been developing fast.One of these sources is fuel cell, mainly due to their high efficiency. Generally fuel cells are powered by hydrogen. However, problems with the storage of hydrogen are the reason for the search of new fuels for fuel cells. Moreover, fuel cells can provide an additional/emergency electricity source in energy systems using combustion engines. So, it is important using the main fuel for powering the fuel cell. One of …

IMI Prevention of Myopia and Its Progression

2021

The prevalence of myopia has markedly increased in East and Southeast Asia, and pathologic consequences of myopia, including myopic maculopathy and high myopia-associated optic neuropathy, are now some of the most common causes of irreversible blindness. Hence, strategies are warranted to reduce the prevalence of myopia and the progression to high myopia because this is the main modifiable risk factor for pathologic myopia. On the basis of published population-based and interventional studies, an important strategy to reduce the development of myopia is encouraging schoolchildren to spend more time outdoors. As compared with other measures, spending more time outdoors is the safest strategy…

2020 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation

2020

2020 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation