Search results for "Mechanisms"
showing 10 items of 587 documents
A Molecular Electron Density Theory Study of the Reactivity of Azomethine Imine in [3+2] Cycloaddition Reactions
2017
The electronic structure and the participation of the simplest azomethine imine (AI) in [3+2] cycloaddition (32CA) reactions have been analysed within the Molecular Electron Density Theory (MEDT) using DFT calculations at the MPWB1K/6-311G(d) level. Electron localisation function (ELF) topological analysis reveals that AI has a pseudoradical structure, while the conceptual DFT reactivity indices characterise this TAC as a moderate electrophile and a good nucleophile. The non-polar 32CA reaction of AI with ethylene takes place through a one-step mechanism with low activation energy, 5.3 kcal/mol-1. A bonding evolution theory (BET) study indicates that this reaction takes place through a non-…
Editorial: Understanding Gamma Delta T Cell Multifunctionality - Towards Immunotherapeutic Applications.
2020
Introduction: gd T cells have been characterized by the expression of a gd T cell receptor (TCR).When the gd TCR and the corresponding ab TCR were first discovered it was assumed that the corresponding cell types were likely to be functionally very similar. However, some 30 years later, we have realized that they are not. Unlike ab T cells, gd T cells (i) sense target antigens independent of MHC molecules; (ii) display NK-cell like innate reactivities, including killing of infected cells as well as microbes; (iii) are able to take up large particulates, including bacteria, and (iv) can act as professional antigen presenting cells. The “stress sensing” abilities of gd T cells have led to a g…
Anti- Toxoplasma Activities of 24 Quinolones and Fluoroquinolones In Vitro: Prediction of Activity by Molecular Topology and Virtual Computational Te…
2000
ABSTRACT The apicoplast, a plastid-like organelle of Toxoplasma gondii , is thought to be a unique drug target for quinolones. In this study, we assessed the in vitro activity of quinolones against T. gondii and developed new quantitative structure-activity relationship models able to predict this activity. The anti- Toxoplasma activities of 24 quinolones were examined by means of linear discriminant analysis (LDA) using topological indices as structural descriptors. In parallel, in vitro 50% inhibitory concentrations (IC 50 s) were determined in tissue culture. A multilinear regression (MLR) analysis was then performed to establish a model capable of classifying quinolones by in vitro acti…
The corticotrophin-releasing factor/urocortin system regulates white fat browning in mice through paracrine mechanisms.
2015
Objectives:\ud The corticotrophin-releasing factor (CRF)/urocortin system is expressed in the adipose tissue of mammals, but its functional role in this tissue remains unknown.\ud \ud Methods:\ud Pharmacological manipulation of the activity of CRF receptors, CRF1 and CRF2, was performed in 3T3L1 white pre-adipocytes and T37i brown pre-adipocytes during in vitro differentiation. The expression of genes of the CRF/urocortin system and of markers of white and brown adipocytes was evaluated along with mitochondrial biogenesis and cellular oxygen consumption. Metabolic evaluation of corticosterone-deficient or supplemented Crhr1-null (Crhr1−/−) mice and their wild-type controls was performed alo…
The role of radiative losses in the late evolution of pulse-heated coronal loops/strands
2012
Radiative losses from optically thin plasma are an important ingredient for modeling plasma confined in the solar corona. Spectral models are continuously updated to include the emission from more spectral lines, with significant effects on radiative losses, especially around 1 MK. We investigate the effect of changing the radiative losses temperature dependence due to upgrading of spectral codes on predictions obtained from modeling plasma confined in the solar corona. The hydrodynamic simulation of a pulse-heated loop strand is revisited comparing results using an old and a recent radiative losses function. We find significant changes in the plasma evolution during the late phases of plas…
Does Population Density Determine the Mating Strategy in Males of the Water Strider Aquarius paludum?
2018
Mating behavior of a large Aquarius paludum paludum (Fabricius 1794) (Hemiptera: Gerridae: Gerrini) population was investigated on several field surveys during the mating season. Both types of mating behavior known for semi-aquatic true bugs were observed in the studied population: aggressive Type I mating for non-territorial males and unaggressive Type II mating for the territorial males. Some males establish individual territories at the lake shores that they defend for around one hour and switch to aggressive mating if they fail to attract a female to mate, while most males remain non-territorial. Radial 1–1.5 meter territories were aggressively defended from other males, conflicts being…
Synthesis of Densely Functionalised 5-Halogen-1,3-oxazin-2-ones byHalogen-Mediated Regioselective Cyclisation of N-Cbz-ProtectedPropargylic Amines: A…
2013
A very efficient synthesis of 5-halogen-1,3-oxazin-2-ones has been accomplished by the halocyclisation reaction of chiral nonracemic N-carbobenzyloxy (N-Cbz)-protected propargylic amines by using I-2, Br-2 and Cl-2 as electrophile sources. The nature of the halogen influences the reaction time and yield. However, in all cases the reaction is totally regioselective taking place through a 6-endo-dig process regardless of the nature of the halogen and of the substituents in the starting material. To rationalise the experimental results, theoretical studies at the B3LYP/6-311G* level have been performed.
Correction: Corrigendum: Long-term, open-labeled extension study of idursulfase in the treatment of Hunter syndrome
2013
CORRIGENDUM: Long-term, open-labeled extension study of idursulfase in the treatment of Hunter syndrome
AE Aurigae: First detection of non-thermal X-ray emission from a bow shock produced by a runaway star
2012
Runaway stars produce shocks when passing through interstellar medium at supersonic velocities. Bow shocks have been detected in the mid-infrared for several high-mass runaway stars and in radio waves for one star. Theoretical models predict the production of high-energy photons by non-thermal radiative processes in a number sufficiently large to be detected in X-rays. To date, no stellar bow shock has been detected at such energies. We present the first detection of X-ray emission from a bow shock produced by a runaway star. The star is AE Aur, which was likely expelled from its birthplace due to the encounter of two massive binary systems and now is passing through the dense nebula IC 405…
Development of a high performance thin layer chromatography method for the rapid qualification and quantification of phenolic compounds and abscisic …
2019
Honey is a natural product with a complex chemical composition consisting of sugars and other bioactive compounds. It is important in many traditional systems of medicine, exhibiting interesting bioactivities, in particular antimicrobial, anti-inflammatory and antioxidant effects. Authentication of botanical origin of honeys is particularly important in this context. Therefore, methods for quality control of honey and detection of its adulteration are very important. A HPTLC method for the quantitative determination of phenolic compounds in honey was developed for the first time. Seven phenolic compounds were detected and determined quantitatively in lime and acacia honey samples. The obtai…