Search results for "complex"
showing 10 items of 5889 documents
Electrocatalytic Behavior of Tetrathiafulvalene (TTF) and Extended Tetrathiafulvalene (exTTF) [FeFe] Hydrogenase Mimics
2021
TTF- and exTTF-containing [(μ-S2)Fe2(CO)6] complexes have been prepared by the photochemical reaction of TTF or exTTF and [(μ-S2)Fe2(CO)6]. These complexes are able to interact with PAHs. In the absence of air and in acid media an electrocatalytic dihydrogen evolution reaction (HER) occurs, similarly to analogous [(μ-S2)Fe2(CO)6] complexes. However, in the presence of air, the TTF and exTTF organic moieties strongly influence the electrochemistry of these systems. The reported data may be valuable in the design of [FeFe] hydrogenase mimics able to combine the HER properties of the [FeFe] cores with the unique TTF properties
Traditional knowledge and practice of the Triassic variegated clay from Silesia (Krasiejów), Poland, in human medicine.
2021
AbstractBackgroundKrasiejów clay (in German: Krascheow) became famous following the discovery of numerous fossilised bones of Upper Triassic amphibians and reptiles, which have been extracted from clay deposits since the 1980s. These organic remnants remained in Krasiejów clay due to the large amount of slime deposits and the optimal concentration of basal mineral salts.The main aims of the paper are to determine the historical evolution of the use of clay in Silesia for therapeutic purposes and to provide a summary of the historical uses of Krasiejów clay as a medical treatment, based on the knowledge of the local population.MethodsThe mode of utilisation of Triassic variegated claystone t…
Syntactic complexity in Finnish-background EFL learners’ writing at CEFR levels A1–B2
2022
Eurooppalaisen viitekehyksen (EVK) merkitys kielikoulutukselle on lisännyt tutkimusta sen taitotasojen kielellisistä piirteistä; tarkempi tieto näistä piirteistä auttaisi EVK:n soveltamista opetusmateriaalien, kurssien ja arviointin laatimiseen. Tutkimuksessa selvitettiin eroavatko EVK:n tasot toisistaan syntaksin kompleksisuuden perusteella. Suomalaiset 14- ja 17-vuotiaat englannin oppijat (N=379) kirjoittivat kolme kirjoitelmaa, jotka arvioitiin EVK:n taitotasoille. Arviointiaineisto tutkittiin monitahoisella Rasch-analyysillä ja tekstien piirteet selvitettiin automaattisilla analyysiohjelmilla. Tuloksien perusteella alimpia EVK-tasoja (A1–A2) erotti selvimmin toisistaan lauseiden ja T-yk…
The role of diet in multiple sclerosis
2022
Multiple sclerosis (MS) is a disease of the central nervous system (CNS), characterized by chronic inflammation associated with autoimmune damage to myelin and axons leading to neurodegeneration. Although the etiology is not fully understood, some factors that increase the risk of disease have been identified. One of the key elements of multidisciplinary approach to the management of MS is a properly balanced diet, e.g. Swank diet. Its main assumption is to reduce the supply of animal fats in favor of fats of plant origin, which contain polyunsaturated fatty acids omega-3. One of the factors influencing the course of the disease is vitamin D deficiency. In 80-90% it is synthesized by exposu…
Role of curcumin in idiopathic pulmonary arterial hypertension treatment: A new therapeutic possibility
2013
The idiopathic pulmonary arterial hypertension is a complex disease that mainly affects pulmonary arterial circulation. This undergoes a remodeling with subsequent reduction of flow in the small pulmonary arteries. Because of this damage an increased vascular resistance gradually develops, and over time it carries out in heart failure. The inflammatory process is a key element in this condition, mediated by various cytokines. The inflammatory signal induces activation of NF-κB, and prompts TGF-β-related signaling pathway. Clinical evolution leads to progressive debilitation, greatly affecting the patient quality of life. The actual therapeutic approaches, are few and expensive, and include …
Minimal unit vector fields
2002
We compute the first variation of the functional that assigns each unit vector field the volume of its image in the unit tangent bundle. It is shown that critical points are exactly those vector fields that determine a minimal immersion. We also find a necessary and sufficient condition that a vector field, defined in an open manifold, must fulfill to be minimal, and obtain a simpler equivalent condition when the vector field is Killing. The condition is fulfilled, in particular, by the characteristic vector field of a Sasakian manifold and by Hopf vector fields on spheres.
Volume, energy and generalized energy of unit vector fields on Berger spheres: stability of Hopf vector fields
2005
We study to what extent the known results concerning the behaviour of Hopf vector fields, with respect to volume, energy and generalized energy functionals, on the round sphere are still valid for the metrics obtained by performing the canonical variation of the Hopf fibration.
Quantifying and Processing Biomedical and Behavioral Signals
2019
Synthesis, crystal structure and magnetic properties of a new cyanide-bridged mixed-valence copper(I)/copper(II) clathrate
2013
A unique cyanide-bridge mixed-valence CuI/CuII clathrate of formula [CuI2(CN)3][{CuII(tren)}2(μ-CN)](CF3SO3)2 [tren = tris(2-aminoethyl)amine] containing cyanide-bridged [{CuII(tren)}2(μ-CN)]3 + binuclear cations stacked between anionic honeycomb layered copper(I) cyanide networks, was synthesized and structurally characterized by single crystal X-ray diffraction. Variable-temperature magnetic susceptibility studies showed that the cyanide bridge mediates a strong antiferromagnetic interaction between the copper(II) centers (J = − 160 cm− 1, the spin Hamiltonian being defined as H = − JSA⋅SB).
Specific recognition of fluoride anion using a metallamacrocycle incorporating a uranyl-salen unit
2008
The design and synthesis of a novel fluoride receptor that uses a salen-complexed Lewis acidic uranyl center as the sole binding site is reported here. This receptor binds fluoride anions in DMSO with a high affinity constant (K > 106 M-1) and exhibits a negligible affinity (K < 10 M-1) towards otherwise effective competitors, such as acetate, phosphate and cyanide anions.