Search results for "BORON"
showing 10 items of 352 documents
Synthesis and structural elucidation of novel antifungal N-(fluorophenyl)piperazinyl benzoxaboroles and their analogues
2019
Abstract Series of novel N-(fluorophenyl)piperazine derivatives of phenylboronic compounds including benzoxaboroles, phenylboronic acids and phenylboronic methyl monoester have been obtained by facile synthetic methods starting from 2-formylphenylboronic acid. Molecular and crystal structures of those novel derivatives have been investigated by single crystal X-ray diffraction method. The Bond Valence Vector Model was used to describe strains in the boron coordination sphere. Microbiological activity of novel benzoxaboroles as well as their corresponding acid analogues against: A. niger, A. terreus, P. ochrochloron, C. tenuis and F. dimerum has been evaluated. The presence of heterocyclic b…
Dipolar and orientational glass formation in two-dimensional films of CO mixtures
2002
Heat-capacity and dielectric measurements have been performed to study orientational and dipolar order and disorder phenomena in submonolayer films of CO and binary mixtures of CO physisorbed on graphite and boron nitride (BN). With both methods transitions to quadrupolar and dipolar ordered low-temperature phases have been found for pure CO. Calorimetric measurements revealed that the dipolar transition of CO on graphite belongs to the universality class of the two-dimensional (2D) Ising model. It will be shown that in dilute mixtures of CO with CH 4 molecules a dramatic suppression of this phase transition occurs. This effect turned out to be much stronger than that previously observed in…
Computational modelling of boron nitride nanostructures based on density-functional tight-binding
2014
Boorinitridin (BN) nanorakenteet ovat sekä rakenteellisesti että lujuusominaisuuksiensa puolesta hyvin samankaltaisia vastaavien hiilirakenteiden kanssa. Suurimpana erona on BN:n sähköinen eristävyys kun taas hiilirakenteet ovat johteita tai puolijohteita. BN onkin hyvin lupaava nanomateriaali ja sille on odotettavissa sovelluksia muun muassa muiden nanorakenteiden suojaajana ja komposiittimateriaalien nanokudosaineena. BN:n nanorakenteiden ominaisuuksia tutkitaan laskennallisesti yleensä joko tiheysfunktionaaliteorialla (DFT) tai tiukan sidoksen (TB) malleilla. Ensin mainittu on tarkka mutta laskennallisesti vaativa, kun taas jälkimmäinen on laskennallisesti kevyt mutta epätarkka. Tässä ty…
Caratterizzazione dosimetrica della facility a neutroni termici del reattore TRIGA di Pavia: studio della dose da fotoni mediante rivelatori ESR di a…
2014
The optimization of the procedures of Neutron Capture Therapy (NCT) for cancer treatments involves research for beam characterization. One major issue for this therapy is the reliable dosimetric determination of the various (neutronic and photonic) components of the employed beam. In particular, the precise and accurate measurements of the gamma photon component is fundamental for evaluating the risks to healthy tissues hit by the mixed field. Among solid state dosimeters the alanine detectors read by Electron Paramagnetic Resonance (EPR) technique present several advantages such as: tissue equivalence for photon and electron beams, linearity of its dose-response over a wide range, high sta…
Synthesis, structure, properties and antimicrobial activity of para trifluoromethyl phenylboronic derivatives
2021
The [2-formyl-4-(trifluoromethyl)phenyl]boronic acid as well as its benzoxaborole and bis(benzoxaborole) derivatives were obtained and their properties studied. The 2-formyl compound displays an unusual structure in the crystalline state, with a significant twist of the boronic group, whereas in DMSO solution it tautomerizes with formation of a cyclic isomer. All the studied compounds exhibit relatively high acidity as well as a reasonable antimicrobial activity. Docking studies showed interactions of all the investigated compounds with the binding pocket of Candida albicans LeuRS. High activity against Bacillus cereus was determined for the 2-formyl compound as well as for the novel bis(be…
Cyclische chirale triarylborane mit einer B←N-Bindung
1985
Abstract The reaction of ortho-lithiated N,N-dimethyl-1-arylethyl-amines with triphenyl- boron leads, with elimination of phenyllithium, to (R)-(−)-2,2,3-trimethyl-1,1-diphenyl -1H-2-azonia-1-borata-indene (1), 2,3-dihydro-1,1,2-trimethyl-3,3-diphenyl- 1H-2-azonia-3-borata-benz[e]indene (2) and 2,3-dihydro-2,2,3-trimethyl-1,1-diphenyl -1H-2-azonia-1-borata-benz[e]indene (3) with a strongB←N bond. 1, 2 and 3 are stable against oxygen, water and alcohols. Triarylboron compounds sensitive to the same reagents are formed by the reaction of triphenylboron with some aryllithium compounds substituted with electron-donating groups.
A computational study of some electric and magnetic properties of gaseous BF3 and BCl3
2005
We present the results of an extended computational study of the electric and magnetic properties connected to Cotton-Mouton birefringences, on the trifluoro- and trichloroborides in the gas phase. The electric dipole polarizabilities, magnetizabilities, quadrupole moments, and higher-order hypersusceptibilities—expressed as quadratic and cubic frequency-dependent response functions—are computed within Hartree-Fock, density-functional, and coupled-cluster response theories employing singly and doubly augmented correlation-consistent basis sets and London orbitals in the magnetic property calculations. The results, which illustrate the capability of time-dependent density-functional theory f…
Preclinical evaluation of antitumor activity of the proteasome inhibitor MLN2238 (ixazomib) in hepatocellular carcinoma cells
2017
AbstractHepatocellular carcinoma (HCC) is one of the common malignancies and is an increasingly important cause of cancer death worldwide. Surgery, chemotherapy, and radiation therapy extend the 5-year survival limit in HCC patients by only 6%. Therefore, there is a need to develop new therapeutic approaches for the treatment of this disease. The orally bioavailable proteasome inhibitor MLN2238 (ixazomib) has been demonstrated to have anticancer activity. In the present study, we investigated the preclinical therapeutic efficacy of MLN2238 in HCC cells through in vitro and in vivo models, and examined its molecular mechanisms of action. MLN2238 inhibited cell viability in human HCC cells He…
Resolving Binding Events on the Multifunctional Human Serum Albumin
2020
Abstract Physiological processes rely on initial recognition events between cellular components and other molecules or modalities. Biomolecules can have multiple sites or mode of interaction with other molecular entities, so that a resolution of the individual binding events in terms of spatial localization as well as association and dissociation kinetics is required for a meaningful description. Here we describe a trichromatic fluorescent binding‐ and displacement assay for simultaneous monitoring of three individual binding sites in the important transporter and binding protein human serum albumin. Independent investigations of binding events by X‐ray crystallography and time‐resolved dyn…
Aza-BODIPY: A New Vector for Enhanced Theranostic Boron Neutron Capture Therapy Applications
2020
Boron neutron capture therapy (BNCT) is a radiotherapeutic modality based on the nuclear capture of slow neutrons by stable 10B atoms followed by charged particle emission that inducing extensive damage on a very localized level (<