Search results for "INTERMED"

Competitive gold-activation modes in terminal alkynes: an experimental and mechanistic study.

2013

The competition between π- and dual σ,π-gold-activation modes is revealed in the gold(I)-catalyzed heterocyclization of 1-(o-ethynylaryl)urea. A noticeable effect of various ligands in gold complexes on the choice of these activation modes is described. The cationic [Au(IPr)](+) (IPr=2,6-bis(diisopropylphenyl)imidazol-2-ylidene) complex cleanly promotes the π activation of terminal alkynes, whereas [Au(PtBu3 )](+) favors intermediate σ,π species. In this experimental and mechanistic study, which includes kinetic and cross-over experiments, several σ-gold, σ,π-gold, and other gold polynuclear reaction intermediates have been isolated and identified by NMR spectroscopy, X-ray diffraction, or …

Contribución al análisis sociológico de la creatividad y la digitalización del campo cultural: creación, intermediación y crisis

2019

The so-called transition to the digital paradigm is eroding the autonomy of the cultural field achieved during the XIX and XX Centuries, subjugating them to economic and technological dynamics. However, the hegemonic discourse tends to interpret this as an overall positive process for the creative domain, focusing on the increase in information resource and creativity tool availability. However, an analysis of the theories and concepts of the sociology of culture reveals a more ambivalent balance. While the notion of authorship and creation can be interpreted from a more cooperative and relativistic view it is arguable whether this concept can be eliminated altogether. Also, although cultur…

Spectroscopic and DFT Characterization of a Highly Reactive Nonheme FeV–Oxo Intermediate

2018

The reaction of [(PyNMe3)FeII(CF3SO3)2], 1, with excess peracetic acid at −40 °C generates a highly reactive intermediate, 2b(PAA), that has the fastest rate to date for oxidizing cyclohexane by a nonheme iron species. It exhibits an intense 490 nm chromophore associated with an S = 1/2 EPR signal having g-values at 2.07, 2.01, and 1.94. This species was shown to be in a fast equilibrium with a second S = 1/2 species, 2a(PAA), assigned to a low-spin acylperoxoiron(III) center. Unfortunately, contaminants accompanying the 2(PAA) samples prevented determination of the iron oxidation state by Mossbauer spectroscopy. Use of MeO-PyNMe3 (an electron-enriched version of PyNMe3) and cyclohexyl pero…

Exploring Organized Interests in Post-Communist Policy-Making: The "Missing Link"

2021

This book examines organized interests in post-communist Central and Eastern Europe (CEE), providing incisive analyses in three critically important policy areas - healthcare, higher education and energy. The four countries surveyed – Poland, Hungary, Slovenia and the Czech Republic – afford rich diversity offering broad empirical material available for cross-country and cross-policy comparative analyses. Featuring interdisciplinary research, the book draws together recent developments in the evolution of post-communist advocacy organizations, their population ecology dynamics, interest intermediation, the influence of organized interests and their (bottom-up and top-down) Europeanization. …

Methicillin-resistant Staphylococcus pseudintermedius as causative agent of dairy cow mastitis.

2013

Staphylococcus pseudintermedius is a coagulase-positive specie similar to Staphylococcus intermedius , frequently associated with pyoderma, otitis and urinary tract infections of dogs and cats (van Duijkeren and others 2011). No information about bovine mastitis caused by S pseudintermedius is available in the literature. Antimicrobial resistance among S pseudintermedius strains is increasing: in the past, susceptibility to most antibiotics was common (Bond and Loeffler 2012), but in the last few years methicillin-resistant S pseudintermedius (MRSP) strains have emerged as a significant animal health problem in veterinary medicine (Schwarz and others 2008, van Duijkeren and others 2008, Wee…

Letter: Thalamotomy-Like Effects From Partial Removal of a Ventral Intermediate Nucleus Deep Brain Stimulator Lead in a Patient With Essential Tremor…

2017

Exchange-transfer in mixed-valence clusters with one migrating hole

1996

Abstract A new mechanism for exchange-transfer specific to hole-type mixed-valence clusters is proposed. The intermediate state in the second-order exchange-transfer process is achieved by the jump of the electron from the spin-core of the dn+1 ion into the empty orbital of the dn ion. As distinguished from the mixed-valence clusters with one delocalized electron this intermediate state is the high-spin one giving rise to a ferromagnetic contribution to the ground manifold. On the basis of angular momentum theory a general solution of the exchange-transfer problem is given for arbitrary nuclearity mixed-valence hole-type clusters with many-electron paramagnetic spin-cores. The interplay bet…

Reactions of rhodium trifluoroacetate with triphenylphosphine and pyridine. Molecular structure of Rh2(O2CCF3)4(py)4

1993

Abstract Rh 2 (O 2 CCF 3 ) 4 reacts with two mol of triphenylphosphine forming the adduct Rh 2 (O 2 CCF 3 ) 4 (PPh 3 ) 2 . This compound in solution, even at room temperature, undergoes slow stepwise orthometalation of the phosphine ligands forming the doubly metalated compound Rh 2 (O 2 CCF 3 ) 2 [(C 6 H 4 )P(C 6 H 5 ) 2 ] 2 . This reaction has been monitored by 31 P NMR spectroscopy detecting in solution three reaction intermediates. Rh 2 (O 2 CCF 3 ) 4 reacts with excess of pyridine to form the compound Rh 2 (O 2 CCF 3 ) 4 (py) 4 that can be structurally classified as a class III adduct. It contains two bridging and two monodentate equatorial carboxylates and two equatorial and two axial…

Efficiency range of the Belousov-Zhabotinsky reaction to induce the self-organization of transient bonds in metallo-supramolecular polymeric systems.

2020

The periodic change of the oxidation state of the metal catalyst in the oscillating Belousov-Zhabotinsky (BZ) reaction has been reported to establish a periodic organization of metallo-supramolecular bonds in polymeric systems, which results in autonomous viscosity oscillations. To appraise the possible extent of quantitative control on the viscosity oscillation features, we assess how the kinetics of the BZ reaction affects the periodic self-organization of the metal-ligand coordination, and vice versa. Our model system includes mono-, bis-, and tetra-functional polyethyleneglycol (PEG) precursors end grafted with terpyridine ligands that are complexed with ruthenium ions, which oscillate …

Expression of the transcription factor Pax6 in the adult rat dentate gyrus

2005

The transcription factor Pax 6 is expressed in precursor cells during embryonic CNS development, and it plays an important role in the regulation of cell proliferation and neuronal fate determination. Pax 6-expressing cells are also present in the adult hippocampal dentate gyrus and subventricular zone/rostral migratory stream, regions in which neuronal precursors exist during adult life. In the adult dentate gyrus, precursor cells are located in the innermost portion of the granule cell layer, and Pax 6-expressing nuclei are most abundant in this region. To examine the putative role of Pax 6 in adult hippocampal neurogenesis, we have studied the proliferative activity, distribution, and ph…