Reticular materials rely on a unique building concept where inorganic and organic building units are stitched together giving access to an almost limitless number of structured ordered porous materials. Given the versatility of chemical elements, underlying nets, and topologies, reticular materials provide a unique platform to design materials for timely technological applications. Reticular materials have now found their way in important societal applications, like carbon capture to address climate change, water harvesting to extract atmospheric moisture in arid environments, and clean energy applications.
View Article and Find Full Text PDFObjective: To describe the practice of ventilator-associated pneumonia (VAP) prevention and control through the incremental introduction of prevention strategies and assess the effect on VAP incidence.
Design: Historical observational surveillance study conducted over 13 years.
Setting: A 12-bed adult intensive care unit (ICU) in a general hospital in Belgium.
Vibrational spectroscopy is an omnipresent spectroscopic technique to characterize functional nanostructured materials such as zeolites, metal-organic frameworks (MOFs), and metal-halide perovskites (MHPs). The resulting experimental spectra are usually complex, with both low-frequency framework modes and high-frequency functional group vibrations. Therefore, theoretically calculated spectra are often an essential element to elucidate the vibrational fingerprint.
View Article and Find Full Text PDFA cluster of Legionnaires' disease (LD) with 10 confirmed, three probable and four possible cases occurred in August and September 2016 in Dendermonde, Belgium. The incidence in the district was 7 cases/100 000 population, exceeding the maximum annual incidence in the previous 5 years of 1.5/100 000.
View Article and Find Full Text PDFA standard local density approximation and its self-interaction corrected version are applied to study spontaneous magnetization, promoted by localized p electron holes, of polar oxygen-terminated ZnO surfaces. The electronic properties and magnetic exchange interactions of three different facets are calculated. It is demonstrated that partially filled oxygen p orbitals of the polar surfaces exhibit magnetic moment formation and long range magnetic order leading to the occurrence of a ferromagnetic ground state.
View Article and Find Full Text PDFUsing first-principles calculations we have studied the valence and structural transitions of the rare earth monotellurides RTe (R = Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb) under pressure. The self-interaction corrected local spin-density approximation is used to establish the ground state valence configuration as a function of volume for the RTe in both the NaCl (B1) and CsCl (B2) structures. We find that in ambient conditions all the RTe are stabilized in the B1 structure.
View Article and Find Full Text PDFMol Plant Microbe Interact
September 2010
The phytopathogenic actinomycete Rhodococcus fascians D188 relies mainly on the linear plasmid-encoded fas operon for its virulence. The bacteria secrete six cytokinin bases that synergistically redirect the developmental program of the plant to stimulate proliferation of young shoot tissue, thus establishing a leafy gall as a niche. A yeast-based cytokinin bioassay combined with cytokinin profiling of bacterial mutants revealed that the fas operon is essential for the enhanced production of isopentenyladenine, trans-zeatin, cis-zeatin, and the 2-methylthio derivatives of the zeatins.
View Article and Find Full Text PDFJ Phys Condens Matter
January 2009
We apply to transition metal monoxides the self-interaction corrected (SIC) local spin density approximation, implemented locally in the multiple scattering theory within the Korringa-Kohn-Rostoker (KKR) band structure method. The calculated electronic structure and in particular magnetic moments and energy gaps are discussed in reference to the earlier SIC results obtained within the linear muffin-tin orbital atomic sphere approximation band structure method, involving transformations between Bloch and Wannier representations, in order to solve the eigenvalue problem and calculate the SIC charge and potential. Since the KKR method can be easily extended to treat disordered alloys, by invoking the coherent potential approximation (CPA), in this paper we compare the CPA approach and supercell calculations to study the electronic structure of NiO with cation vacancies.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2009
Decades ago, the importance of cytokinins (CKs) during Rhodococcus fascians pathology had been acknowledged, and an isopentenyltransferase gene had been characterized in the fas operon of the linear virulence plasmid, but hitherto, no specific CK(s) could be associated with virulence. We show that the CK receptors AHK3 and AHK4 of Arabidopsis thaliana are essential for symptom development, and that the CK perception machinery is induced upon infection, underlining its central role in the symptomatology. Three classical CKs [isopentenyladenine, trans-zeatin, and cis-zeatin (cZ)] and their 2-methylthio (2MeS)-derivatives were identified by CK profiling of both the pathogenic R.
View Article and Find Full Text PDFWe report measured dipolar asymmetry ratios at the LIII edges of the heavy rare-earth metals. The results are compared with a first-principles calculation and excellent agreement is found. A simple model of the scattering is developed, enabling us to reinterpret the resonant x-ray scattering in these materials and to identify the peaks in the asymmetry ratios with features in the spin and orbital moment densities.
View Article and Find Full Text PDFThe heavy rare earth elements crystallize into hexagonally close packed (h.c.p.
View Article and Find Full Text PDFPhys Rev Lett
October 2006
The ab initio self-interaction-corrected local-spin-density approximation is used to study the electronic structure of both stoichiometric and nonstoichiometric nickelates. From total energy considerations it emerges that, in their ground state, both LiNiO2 and NaNiO2 are insulators, with the Ni ion in the Ni3+ low-spin state (t(2g)(6)e(g)(1)) configuration. It is established that a substitution of a number of Li/Na atoms by divalent impurities drives an equivalent number of Ni ions in the NiO2 layers from the Jahn-Teller (JT)-active trivalent low-spin state to the JT-inactive divalent state.
View Article and Find Full Text PDFIntroduction: The diagnosis of invasive pulmonary aspergillosis, according to the criteria as defined by the European Organisation for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG), is difficult to establish in critically ill patients. The aim of this study is to address the clinical significance of isolation of Aspergillus spp. from lower respiratory tract samples in critically ill patients on the basis of medical and radiological files using an adapted diagnostic algorithm to discriminate proven and probable invasive pulmonary aspergillosis from Aspergillus colonisation.
View Article and Find Full Text PDFThe electronic structure of PuO(2+/-x) was studied using first-principles quantum mechanics, realized with the self-interaction corrected local spin density method. In the stoichiometric PuO2 compound, Pu occurs in the Pu(IV) oxidation state, corresponding to a localized f4 shell. If oxygen is introduced onto the octahedral interstitial site, the nearby Pu atoms turn into Pu(V) (f3) by transferring electrons to the oxygen.
View Article and Find Full Text PDFThe glyoxylate cycle and the glycine cleavage system are part of conserved metabolic pathways involved in the chronic persistence of microorganisms in animal hosts. In the chromosome of the plant pathogen Rhodococcus fascians, the vic locus has been identified as a region containing genes essential for persistence inside induced leafy galls. Sequence analysis showed that this 18-kb locus is syntenic with chromosomal regions of Mycobacterium species that encompass the 'persistence' loci of these mammalian pathogens.
View Article and Find Full Text PDFThe electronic structures of URh (3), UPd (3), UPt (3), and UAu (3) are calculated with the self-interaction corrected local-spin-density approximation. We find that only in URh (3) the f electrons are fully delocalized. UPt (3) has one f electron localized at each U site, while a localized f(2) configuration of the U ion is found for UPd (3).
View Article and Find Full Text PDFThe gram-positive plant pathogen Rhodococcus fascians provokes leafy gall formation on a wide range of plants through secretion of signal molecules that interfere with the hormone balance of the host. Crucial virulence genes are located on a linear plasmid, and their expression is tightly controlled. A mutant with a mutation in a chromosomal locus that affected virulence was isolated.
View Article and Find Full Text PDFAn ab initio local spin density study of YBa2Cu3O6, YBa2Cu3O6.5, and YBa2Cu3O7 is presented. The method includes self-interaction corrections for the Cu d states, which enables a description of various valency configurations of both planar and chain Cu atoms.
View Article and Find Full Text PDFThe effect of Rhodococcus fascians, the causal agent of leafy gall disease, on the mitotic behavior of synchronized tobacco Bright Yellow-2 (BY-2) cells was investigated. Incubation of aphidicolin-synchronized BY-2 cells with R. fascians cells specifically resulted in a broader mitotic index peak, an effect that was linked to an intact and expressed fas virulence locus.
View Article and Find Full Text PDFRhodococcus fascians can interact with many plant species and induce the formation of either leafy galls or fasciations. To provoke symptoms, R. fascians strain D188 requires pathogenicity genes that are located on a linear plasmid, pFiD188.
View Article and Find Full Text PDFIsoniazid (INH) is the most widely used of the antituberculosis drugs. An acute overdose is potentially fatal and is characterized by the clinical triad of repetitive seizures unresponsive to the usual anticonvulsants, metabolic acidosis with a high anion gap and coma. The diagnosis of INH overdose should be considered in any patient who presents with an unexplained metabolic acidosis and convulsions.
View Article and Find Full Text PDFThe heavy-fermion compound [Formula: see text] has been studied using the fully relativistic spin-polarized mean muffin-tin orbital method within the local density approximation. Two separate calculations, one where the f electron is treated as a valence electron and the other where it is treated as part of the core, have been performed and the Fermi surface is obtained. The angular-dependent de Haas - van Alphen (dHvA) frequencies are calculated in both cases and they are compared with the experimental dHvA frequencies.
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