Search results for "complex"
showing 10 items of 5889 documents
Experimental FTIR-MI and Theoretical Studies of Isocyanic Acid Aggregates
2023
Homoaggregates of isocyanic acid (HNCO) were studied using FTIR spectroscopy combined with a low-temperature matrix isolation technique and quantum chemical calculations. Computationally, the structures of the HNCO dimers and trimers were optimized at the MP2, B3LYPD3 and B2PLYPD3 levels of theory employing the 6-311++G(3df,3pd) basis set. Topological analysis of the electron density (AIM) was used to identify the type of non-covalent interactions in the studied aggregates. Five stable minima were located on the potential energy surface for (HNCO)2, and nine were located on the potential energy surface for (HNCO)3. The most stable dimer (D1) involves a weak, almost linear N-H⋯N hydrog…
Matrix Isolation FTIR and Theoretical Study of Weakly Bound Complexes of Isocyanic Acid with Nitrogen.
2021
Weak complexes of isocyanic acid (HNCO) with nitrogen were studied computationally employing MP2, B2PLYPD3 and B3LYPD3 methods and experimentally by FTIR matrix isolation technique. The results show that HNCO interacts specifically with N2. For the 1:1 stoichiometry, three stable minima were located on the potential energy surface. The most stable of them involves a weak, almost linear hydrogen bond from the NH group of the acid molecule to nitrogen molecule lone pair. Two other structures are bound by van der Waals interactions of N⋯N and C⋯N types. The 1:2 and 2:1 HNCO complexes with nitrogen were computationally tracked as well. Similar types of interactions as in the 1:1 complexes were …
La promozione della capacità di analisi di situazioni educative complesse nei futuri insegnanti di scuola primaria.The promotion of future primary sc…
2011
Il tema della capacità di risoluzione di problemi educativi da parte di coloro che si accingono a svolgere la professione di insegnante, implica l’acquisizione di strategie per reagire in modo adeguato alla complessità dei problemi che connotano le situazioni educative. Si presentano i risultati di una ricerca triennale che ha coinvolto in totale 450 studenti del corso di Laurea in Scienze della Formazione Primaria dell’Università di Palermo. Con la ricerca ci si è posti l’obiettivo di rilevare la capacità degli studenti di affrontare lo studio con un atteggiamento volto alla comprensione e alla soluzione dei problemi concreti con i quali ci si confronta nel lavoro educativo. Si è inteso pr…
La méthode de la complexité pour comprendre la plurisémiocité des discours numériques : de l’efficacité de TikTok
2023
Based on a corpus of videos collected on the Tik Tok platform, our study aims to analyse the plurisemicity and memetic functioning of these productions. We seek to show the effectiveness of these native productions of Tik Tok through a strategic and integrated use of different semis. This is why we are working on the analysis of digital discourses and post-dualist epistemological work in this field of language sciences. Through our analytical work, we wish to contribute to the questioning of written/oral, man/machine and text/image oppositions.
Firsts lysidinyl- and lysidinium-triphosphines Pd(II) complexes
2010
International audience; The preparation of first lysidinyl-triphosphine ligand (named Triphosline) is described in three steps which are first a Michael type addition of imidazolidine (or lysidine) to diethylvinylphosphonate, second a phosphonate reduction with LiAlH4 and third an anti-Markovnikov radical addition of the primary phosphine to diphenylvinylphosphine. The Triphosline behaves as a tridentate P-coordinating ligand in palladium(II) complexes. The dangling lysidine function is then cleanly and totally alkylated by methyl iodide to lead to a new kind of lysidinium-triphosphine complexes. Subsequent anion exchange with TlPF6 affords the first example of a chloride free lysidinium-tr…
Nuclear entry and egress of parvoviruses.
2022
Parvoviruses are small non-enveloped single-stranded DNA viruses, which depend on host cell nuclear transcriptional and replication machinery. After endosomal exposure of nuclear localization sequence and a phospholipase A2 domain on the capsid surface, and escape into the cytosol, parvovirus capsids enter the nucleus. Due to the small capsid diameter of 18–26 nm, intact capsids can potentially pass into the nucleus through nuclear pore complexes (NPCs). This might be facilitated by active nuclear import, but capsids may also follow an alternative entry pathway that includes activation of mitotic factors and local transient disruption of the nuclear envelope. The nuclear entry is followed b…
Improving soil and water conservation and ecosystem services by sustainable soil management practices: From a global to an Italian soil partnership
2020
The UN Sustainable Development Goals (SDGs) identify the need to restore degraded soils in order to improve productivity and the provision of ecosystem services. The aim is to support food production, store and supply clean water, conserve biodiversity, sequester carbon, and improve soil resilience in a context of climate change. Within this framework, in order to achieve the SDGs and to correct land management in the long-term, soil management is considered mandatory. The reduction of land degradation should be based on various sustainable soil management practices that improve and maintain soil organic matter levels, increase water infiltration, and improve soil water management. This tec…
Droplet digital PCR as a tool for investigating dynamics of cryptic symbionts
2021
Abstract Interactions among symbiotic organisms and their hosts are major drivers of ecological and evolutionary processes. Monitoring the infection patterns among natural populations and identifying factors affecting these interactions are critical for understanding symbiont–host relationships. However, many of these interactions remain understudied since the knowledge about the symbiont species is lacking, which hinders the development of appropriate tools. In this study, we developed a digital droplet PCR (ddPCR) assay based on apicomplexan COX1 gene to detect an undescribed agamococcidian symbiont. We show that the method gives precise and reproducible results and enables detecting cryp…
La complejidad del conocimiento: retos para su eficaz creación y transferencia en la organización innovadora
2012
Una eficaz creación y transferencia de conocimiento es esencial para promover el aprendizaje organizativo y la innovación. Con este postulado como idea principal, este artículo explora sendos casos de proyectos de gestión del conocimiento en dos empresas españolas, profundizando en tres características problemáticas del conocimiento: dispersión, ambigüedad y perturbación. Los resultados recomiendan diseñar cuidadosamente el proyecto de gestión de conocimiento teniendo en cuenta: (i) el propósito de la estrategia de gestión de conocimiento, (ii) el equipo coordinador del proyecto y la distribución de responsabilidades, y (iii) los requerimientos y restricciones organizativos, incluyendo proc…
Nitrated Fatty Acids Modulate the Physical Properties of Model Membranes and the Structure of Transmembrane Proteins
2017
Nitrated fatty acids (NO2 -FAs) act as anti-inflammatory signal mediators, albeit the molecular mechanisms behind NO2 -FAs' influence on diverse metabolic and signaling pathways in inflamed tissues are essentially elusive. Here, we combine fluorescence measurements with surface-specific sum frequency generation vibrational spectroscopy and coarse-grained computer simulations to demonstrate that NO2 -FAs alter lipid organization by accumulation at the membrane-water interface. As the function of membrane proteins strongly depends on both, protein structure as well as membrane properties, we consecutively follow the structural dynamics of an integral membrane protein in presence of NO2 -FAs. …