Search results for "Solid-state"
showing 10 items of 530 documents
Self-assembly of 1- and 2-Dimensional Multicompartmental Arrays via the 2-Aminopyrimidine H-Bonding Motif and Selective Guest Inclusion
2000
Abstract The H-bond mediated self-assembly of aminopyrimidine substituted anthracene derivatives 4 and 5, respectively, generate 1- and 2-dimensional multicompartmental arrays in the solid state as revealed by X-ray crystallographic analysis. The derived ‘pigeon-hole’ lattice is defined by syn-coplanar positioning of anthracene moieties at a distance of ca. 7 A, allowing the formation of selective clathrate-type inclusion entities with guests of appropriate shape and size, in particular phenazine, which presents both structural and interactional complementarity. These data provide insight into the interplay of the different structural and interactional features of the molecular components t…
Mechanochemical synthesis of antifungal bis(benzoxaboroles)
2020
Several piperazine bis(benzoxaboroles) have been obtained both in solution as well as in the solid state. The environmentally friendly mechanochemical approach – hitherto not applied for the preparation of benzoxaboroles – was particularly beneficial in the case of two products afforded in low yields in solution. The in vitro studies showed high potential of the studied bis(fluorobenzoxaboroles) as antifungal agents, highlighting also the influence of the fluorine substituent position on their microbiological activity. The highest activity against A. niger, A. terreus, P. ochrochloron, C. tenuis and C. albicans was displayed by the analogue of the known benzoxaborole antifungal drug Kerydin…
A biocompatible ZnNa2-based metal–organic framework with high ibuprofen, nitric oxide and metal uptake capacity
2020
Metal organic frameworks (MOFs) have received significant attention in recent years in the areas of biomedical and environmental applications. Among them, mixed metal MOFs, although promising, are relatively few in number in comparison with their homometallic analogues. The employment of benzophenone-4,4′-dicarboxylic acid (bphdcH2) in mixed metal MOF chemistry provided access to a 3D MOF, [Na2Zn(bphdc)2(DMF)2]n (NUIG1). NUIG1 displays a new topology and is a rare example of a mixed metal MOF based on 1D rod secondary building units. UV-vis, HPLC, TGA, XRPD, solid state NMR and computational studies indicated that NUIG1 exhibits an exceptionally high Ibuprofen (Ibu) and nitric oxide adsorpt…
Screening and authentication of herbal formulations based on microextraction-assisted voltammetry of microparticles
2015
A simple solid state electrochemical methodology for screening and authentication of herbal formulations is described. The proposed method is based on the recording of the voltammetric response, in contact with aqueous buffers, of microparticulate films of antioxidant compounds resulting from micro-extraction of dried herbal samples with ethanol or acetone. The obtained voltammetric responses led us to differentiate between diverse active components upon application of bivariate and multivariate chemometric techniques. Resolution of herbal preparations containing two or more components is possible when well-separated voltammetric signals are recorded. In favorable cases, such characteristic…
Discovery of indigoid-containing clay pellets from La Blanca: significance with regard to the preparation and use of Maya Blue
2014
Analytical studies using extraction/liquid chromatography, pyrolysis–silylation gas chromatography–mass spectrometry, visible and infrared spectroscopies, solid state voltammetry and electron microscopy on a set of spherical greenish pellets discovered in the Structure 4H1 of the ancient Maya site of La Blanca (Peten Department, Guatemala), dated in the Terminal Classic period, confirm the presence of indigoids (dehydroindigo, indigo) associated to palygorskite. The appearance of such pieces, whose origin and function is uncertain, but most likely correspond to residuals of a decorative plaster, can be considered as indicative of the use of Maya Blue in a quotidian context, thus suggesting …
Solid-State Fermentations of the Genus Aspergillus
1994
For the majority of filamentous fungal species, solid-state media are the natural life media. Growth can occur on the surface or within the whole substrate, depending on the porosity. Industrial solid-state fermentations have been developed largely in traditional food industries such as cheese, Oriental fermentations, fermented vegetables, meat, and other products, and in modern biotechnological industries such as antibiotics and enzymes. At the industrial scale, the latter fermentations allow for a decrease in the drying costs of the final products.
The FRAM robotic telescope for atmospheric monitoring at the Pierre Auger Observatory
2021
FRAM (F/Photometric Robotic Atmospheric Monitor) is a robotic telescope operated at the Pierre Auger Observatory in Argentina for the purposes of atmospheric monitoring using stellar photometry. As a passive system which does not produce any light that could interfere with the observations of the fluorescence telescopes of the observatory, it complements the active monitoring systems that use lasers. We discuss the applications of stellar photometry for atmospheric monitoring at optical observatories in general and the particular modes of operation employed by the Auger FRAM. We describe in detail the technical aspects of FRAM, the hardware and software requirements for a successful operati…
Measurement of untruncated nuclear spin interactions via zero- to ultralow-field nuclear magnetic resonance
2015
Zero- to ultra-low-field nuclear magnetic resonance (ZULF NMR) provides a new regime for the measurement of nuclear spin-spin interactions free from effects of large magnetic fields, such as truncation of terms that do not commute with the Zeeman Hamiltonian. One such interaction, the magnetic dipole-dipole coupling, is a valuable source of spatial information in NMR, though many terms are unobservable in high-field NMR, and the coupling averages to zero under isotropic molecular tumbling. Under partial alignment, this information is retained in the form of so-called residual dipolar couplings. We report zero- to ultra-low-field NMR measurements of residual dipolar couplings in acetonitrile…
Bile acid–cysteamine conjugates: Structural properties, gelation, and toxicity evaluation
2011
Abstract Design, synthesis, and characterization of six novel bile acid–cysteamine conjugates together with investigation of their structural studies, gelation properties, and preliminary toxicity evaluation, are reported. Solid state properties of selected compounds were studied by means of X-ray diffraction and 13C CPMAS NMR spectroscopy. N-(2-thioethyl)-3α,7α,12α-trihydroxy-5β-cholan-24-amide was shown to exhibit (pseudo)polymorphism, and a single crystal structure of its non-stoichiometric hydrate is reported herein. Cholyl and dehydrocholyl derivatives bearing three functionalities in their steroidal backbone were shown to undergo self-assembly leading to gelation in certain organic so…
Rapid online solid-state battery diagnostics with optically pumped magnetometers
2020
Applied Sciences 10(21), 7864 (2020). doi:10.3390/app10217864