Search results for " complex"
showing 10 items of 3391 documents
Increased conformational rigidity of humic substances by oxidative biomimetic catalysis
2005
A synthetic water-soluble meso-tetra(2,6-dichloro-3-sulfonatophenyl)porphyrinate of iron(III) chloride, Fe(TDCPPS)Cl, was employed as a biomimetic catalyst in the oxidative coupling of terrestrial humic materials. High-performance size-exclusion chromatography (HPSEC), solid-state nuclear magnetic resonance (CPMAS-(13)C NMR), electron paramagnetic resonance (EPR), and diffuse reflectance infrared spectroscopy (DRIFT) were used to follow conformational and structural changes brought about in different humic materials by the oxidative coupling. Increase in apparent weight-average molecular weight (Mw(a)) occurred invariably for all humic substances with the oxidative polymerization catalyzed …
Epigenetic involvement in Hutchinson-Gilford progeria syndrome: a mini-review.
2013
Hutchinson-Gilford progeria syndrome (HGPS) is a rare human genetic disease that leads to a severe premature ageing phenotype, caused by mutations in the <i>LMNA</i> gene. The <i>LMNA</i> gene codes for lamin-A and lamin-C proteins, which are structural components of the nuclear lamina. HGPS is usually caused by a de novo <i>C1824T</i> mutation that leads to the accumulation of a dominant negative form of lamin-A called progerin. Progerin also accumulates physiologically in normal ageing cells as a rare splicing form of lamin-A transcripts. From this perspective, HGPS cells seem to be good candidates for the study of the physiological mechanisms of ageing…
Functional Assessment of Variants in the TSC1 and TSC2 Genes Identified in Individuals with Tuberous Sclerosis Complex
2011
The effects of missense changes and small in-frame deletions and insertions on protein function are not easy to predict, and the identification of such variants in individuals at risk of a genetic disease can complicate genetic counselling. One option is to perform functional tests to assess whether the variants affect protein function. We have used this strategy to characterize variants identified in the TSC1 and TSC2 genes in individuals with, or suspected of having, Tuberous Sclerosis Complex (TSC). Here we present an overview of our functional studies on 45 TSC1 and 107 TSC2 variants. Using a standardized protocol we classified 16 TSC1 variants and 70 TSC2 variants as pathogenic. In add…
Huntingtin controls neurotrophic support and survival of neurons by enhancing BDNF vesicular transport along microtubules.
2004
AbstractPolyglutamine expansion (polyQ) in the protein huntingtin is pathogenic and responsible for the neuronal toxicity associated with Huntington's disease (HD). Although wild-type huntingtin possesses antiapoptotic properties, the relationship between the neuroprotective functions of huntingtin and pathogenesis of HD remains unclear. Here, we show that huntingtin specifically enhances vesicular transport of brain-derived neurotrophic factor (BDNF) along microtubules. Huntingtin-mediated transport involves huntingtin-associated protein-1 (HAP1) and the p150Glued subunit of dynactin, an essential component of molecular motors. BDNF transport is attenuated both in the disease context and b…
Incorporation of Pt(II) complex with [amino-2(methylthio)(1,2,4)triazole-(1,5-a)pyrimidine-6-carboxylic-acid] ligand in MCM41 for controlled release
2015
Drug carriers play a critical role for the loading and the release of the drug. A promising frontier is represented by a new class of innovative medicines that represents directional transport vehicles "drug delivery" and consist of assembled structures carrier (nano)-drug. Silica-based materials, nontoxic, biocompatible, have been used as adjuvant and excipient in pharmaceutical technology. In this class of compounds, the mesoporous materials, such as MCM41, SBA-15 and hexagonal mesoporous silica, have been investigated for medication and drug delivery due to their properties. In fact, these materials show a large specific pore volume made up of regular pores having a diameter in the nanom…
Application of Silsesquioxanes in the Preparation of Polyolefin-Based Materials
2023
This paper is a review of studies on the use of the polyhedral oligomeric silsesquioxanes (POSS) of various structures in the synthesis of polyolefins and the modification of their properties, namely: (1) components of organometallic catalytic systems for the polymerization of olefins, (2) comonomers in the copolymerization with ethylene, and (3) fillers in composites based on polyolefins. In addition, studies on the use of new silicon compounds, i.e., siloxane–silsesquioxane resins, as fillers for composites based on polyolefins are presented. The authors dedicate this paper to Professor Bogdan Marciniec on the occasion of his jubilee.
Species size affects hatching response to different temperature regimes in a rotifer cryptic species complex
2013
The strategy of decreasing size with increasing temperature known as Bergmann’s rule operates at geographic scale and in spite of extensive studies still presents a puzzle to researches. The aim of this work was to verify whether patterns of diapausing egg hatching of closely related species are consistent with the expectations from Bergmann’s rule. In a laboratory study of the cryptic species complex of the rotifer Brachionus plicatilis, the response to temperature (17.5, 22.5, and 25.0 °C) of diapausing eggs collected in a pond where the three tested species coexist was assessed by (1) the number of hatchlings emerging or (2) the time needed to hatch. Our results show that the response to…
Catena-poly[[di-n-butyltin(IV)]-mu-trifluoromethanesulfonato-[[di-n-butyl(trifluoromethanesulfonato)tin(IV)]-di-mu-hydroxo]]
2006
International audience
Double-CO32− Centered [CoII5] Wheel and Modeling of Its Magnetic Properties
2010
A high-spin Co(II) cluster with a rare pentagonal molecular structure and formula [Co(5)(CO(3))(2)(bpp)(5)]ClO(4) (1; Hbpp is 2,6-bis(phenyliminomethyl)-4-methylphenolate) has been synthesized and characterized by single-crystal X-ray diffraction. This topology arises from fusing five [Co(2)(bpp)] moieties in a cyclic manner around two CO(3)(2-) central ligands, resulting in propeller-like configuration. The irregular coordination of the carbonate ions to the metal centers results in a combination of coordination numbers (CNs) of the Co(II) ions of five and six. The bulk magnetization of this complicated magnetically exchanged system has been modeled successfully by employing a matrix diago…
Chlorido(2,2′-{[2-(1-methyl-1H-imidazol-2-yl-κN 3)imidazolidine-1,3-diyl-κN]bis(methylene)}bis(1-methyl-1H-imidazole-κN 3))copper(II) perchlorate
2019
In the crystal structure of the title complex, [CuCl(C17H24N8)]ClO4, the copper(II) metal exhibits an N4Cl pentacoordinate environment in a distorted square-pyramidal geometry. Coordination to the metal centre occurs through the three 1-methylimidazole N atoms from the pendant groups, one amine N atom from the imidazolidine moiety and one chlorido anion. Intermolecular interactions take place at two of the 1-methyl-imidazole rings in the form of parallel-displaced π–π stacking interactions forming chains parallel to the a axis. Three O atoms of the perchlorate anion are rotationally disordered between two orientations with occupancies of 0.5.