Search results for " HOMO"
showing 10 items of 1143 documents
Wpływ podstawienia karbazolu pierścieniem fulwenowym na ich strukturę elektronową
2019
Na właściwości optoelektroniczne układów organicznych, w znacznym stopniu ma wpływ ich struktura elektronowa. Poznanie zatem czynników determinujących ich strukturę elektronową stanowi istotny punkt wyjścia w badaniach nad możliwościami potencjalnego ich zastosowania. Wśród wielu narzędzi, którymi można modyfikować π-elektronową delokalizację w układach aromatycznych jest efekt podstawnikowy. Rolę podstawników mogą również pełnić układy cykliczne a w szczególności te, które nie spełniają reguły Hückla, gdyż ich dążność do stanu aromatycznego, jest czynnikiem generującym ruch elektronów π w strukturach. Przykładem takiego pierścienia może być fulwen, który posiada 5 elektronów π i w miarę mo…
Rola efektu podstawnikowego w sprzężeniu π-elektronowym w N-podstawionym karbazolu
2019
Modyfikacja właściwości optoelektronowych materiałów organicznych w wielu przypadkach sprowadza się do wywołania zmian w ich strukturze elektronowej, a w szczególności w π-elektronowej delokalizacji w obrębie całej molekuły. Dużą uwagę zajmują w tych badaniach układy skondensowane zawierające pierścienie aromatyczne, niearomatyczne oraz hetero atomy. Do układów tych można zaliczyć, między innymi, karbazol i jego pochodne, który znajduje zastosowanie w organicznych materiałach optycznych i elektronowych. W niniejszej publikacji zaprezentowano wyniki z przeprowadzonych badań nad wpływem podstawienia pierścienia fulwenowego na atomie azotu oraz podstawników o zróżnicowanym charakterze elektron…
Chromosome Painting in Cercopithecus petaurista (Schreber, 1774) Compared to Other Monkeys of the Cercopithecini Tribe (Catarrhini, Primates)
2023
The Cercopithecini tribe includes terrestrial and arboreal clades whose relationships are controversial, with a high level of chromosome rearrangements. In order to provide new insights on the tribe’s phylogeny, chromosome painting, using the complete set of human syntenic probes, was performed in Cercopithecus petaurista, a representative species of the Cercopithecini tribe. The results show C. petaurista with a highly rearranged karyotype characterized by the fission of human chromosomes 1, 2, 3, 5, 6, 8, 11, and 12. These results compared with the literature data permit us to confirm the monophyly of the Cercopithecini tribe (fissions of chromosomes 5 and 6), as previously proposed by ch…
Multi-scale modelling of heterogeneous shell structures
2011
International audience; This paper reviews multi-scale computational homogenisation frameworks for the non-linear behaviour of heterogeneous thin planar shells. Based on a review of some of the currently available methods, a computational homogenisation scheme for shells is applied on to representative volume elements for plain weave composites. The effect of flexural loading on the potential failure modes of such materials is analysed, focusing on the reinforcement-matrix delamination mechanism. The attention is next shifted toward failure localisation in masonry unit cells. Subsequently, a recently developed computational FE2 solution scheme accounting for damage localisation at structura…
Eksperimenti ar topoloģisko datu analīzi
2022
Maģistra darba mērķis ir iepazīstināt ar topoloģisko datu analīzi, kas ir pieeja datu kopu analīzei, izmantojot topoloģijas, kā matemātikas novirziena, metodes. Šī inovatīvā datu analīzes metode pasaulē pēdējos gados strauji attīstās un ar vien plašāk tiek pielietota, lai iegūtu informāciju no sarežģītiem, liela apjoma, daudzdimensionāliem datiem. Pašreiz nekur nav atrodams topoloģiskās datu analīzes apraksts un pielietojamība, latviešu valodā. Darbā tiek apskatīti divi dažādi uz topoloģiskās datu analīzes balstīti algoritmi - Mapper un ToMATo, kuru veiksmīgā izmantošanā noteicošais ir pareizu parametru izvēle. Darbā tiek pētītas un piedāvātas šo algoritmu parametru optimizācijas metodes un…
The prolyl-isomerase PIN1 is essential for nuclear Lamin-B structure and function and protects heterochromatin under mechanical stress.
2021
Summary: Chromatin organization plays a crucial role in tissue homeostasis. Heterochromatin relaxation and consequent unscheduled mobilization of transposable elements (TEs) are emerging as key contributors of aging and aging-related pathologies, including Alzheimer’s disease (AD) and cancer. However, the mechanisms governing heterochromatin maintenance or its relaxation in pathological conditions remain poorly understood. Here we show that PIN1, the only phosphorylation-specific cis/trans prolyl isomerase, whose loss is associated with premature aging and AD, is essential to preserve heterochromatin. We demonstrate that this PIN1 function is conserved from Drosophila to humans and prevents…
Regulation of type 1 fimbriae synthesis and biofilm formation by the transcriptional regulator LrhA of Escherichia coli
2005
Type 1 fimbriae ofEscherichia colifacilitate attachment to the host mucosa and promote biofilm formation on abiotic surfaces. The transcriptional regulator LrhA, which is known as a repressor of flagellar, motility and chemotaxis genes, regulates biofilm formation and expression of type 1 fimbriae. Whole-genome expression profiling revealed that inactivation oflrhAresults in an increased expression of structural components of type 1 fimbriae.In vitro, LrhA bound to the promoter regions of the twofimrecombinases (FimB and FimE) that catalyse the inversion of thefimApromoter, and to the invertible element itself. TranslationallacZfusions with these genes and quantification offimEtranscript le…
Biochemical properties of hepatitis C virus NS5B RNA-dependent RNA polymerase and identification of amino acid sequence motifs essential for enzymati…
1997
The NS5B protein of the hepatitis C virus (HCV) is an RNA-dependent RNA polymerase (RdRp) (S.-E. Behrens, L. Tomei, and R. De Francesco, EMBO J. 15:12-22, 1996) that is assumed to be required for replication of the viral genome. To further study the biochemical and structural properties of this enzyme, an NS5B-hexahistidine fusion protein was expressed with recombinant baculoviruses in insect cells and purified to near homogeneity. The enzyme was found to have a primer-dependent RdRp activity that was able to copy a complete in vitro-transcribed HCV genome in the absence of additional viral or cellular factors. Filter binding assays and competition experiments showed that the purified enzym…
Hölder regularity for the gradient of the inhomogeneous parabolic normalized p-Laplacian
2018
In this paper, we study an evolution equation involving the normalized [Formula: see text]-Laplacian and a bounded continuous source term. The normalized [Formula: see text]-Laplacian is in non-divergence form and arises for example from stochastic tug-of-war games with noise. We prove local [Formula: see text] regularity for the spatial gradient of the viscosity solutions. The proof is based on an improvement of flatness and proceeds by iteration.
The mitogen-activated protein kinase p38 pathway is conserved in metazoans: Cloning and activation of p38 of the SAPK2 subfamily from the sponge Sube…
2000
Our recent data suggest that during auto- and allograft recognition in sponges (Porifera), cytokines are differentially expressed. Since the mitogen-activated protein kinase (MAPK) signal transduction modulates the synthesis and release of cytokines, we intended to identify one key molecule of this pathway. Therefore, a cDNA from the marine sponge Suberites domuncula encoding the MAPK was isolated and analyzed. Its encoded protein is 366 amino acids long (calculated Mr 42 209), has a TGY dual phosphorylation motif in protein kinase subdomain VIII and displays highest overall similarity to the mammalian p38 stress activated protein kinase (SAPK2), one subfamily of MAPKs. The sponge protein w…