271 research outputs found
High diversity and morphological convergence among melanised fungi from rock formations in the Central Mountain System of Spain
Melanised fungi were isolated from rock surfaces in the Central Mountain System of Spain. Two hundred sixty six isolates were recovered from four geologically and topographically distinct sites. Microsatellite-primed PCR techniques were used to group isolates into genotypes assumed to represent species. One hundred and sixty three genotypes were characterised from the four sites. Only five genotypes were common to two or more sites. Morphological and molecular data were used to characterise and identify representative strains, but morphology rarely provided a definitive identification due to the scarce differentiation of the fungal structures or the apparent novelty of the isolates. Vegetative states of fungi prevailed in culture and in many cases could not be reliably distinguished without sequence data. Morphological characters that were widespread among the isolates included scarce micronematous conidial states, endoconidia, mycelia with dark olive-green or black hyphae, and mycelia with torulose, isodiametric or moniliform hyphae whose cells develop one or more transverse and/or oblique septa. In many of the strains, mature hyphae disarticulated, suggesting asexual reproduction by a thallic micronematous conidiogenesis or by simple fragmentation. Sequencing of the internal transcribed spacers (ITS1, ITS2) and 5.8S rDNA gene were employed to investigate the phylogenetic affinities of the isolates. According to ITS sequence alignments, the majority of the isolates could be grouped among four main orders of Pezizomycotina: Pleosporales, Dothideales, Capnodiales, and Chaetothyriales. Ubiquitous known soil and epiphytic fungi species were generally absent from the rock surfaces. In part, the mycota of the rock surfaces shared similar elements with melanised fungi from plant surfaces and fungi described from rock formations in Europe and Antarctica. The possibility that some of the fungi were lichen mycobionts or lichen parasites could not be ruled out
The chemical consequences of the gradual decrease of the ionic radius along the Ln-series
[Abstract] In the periodical system, the lanthanides (the 15 elements in the periodic table between barium and hafnium) are unique in the sense that their trivalent cations have their valence electrons hidden behind the 5s and 5p electrons. They show a gradual decrease in ionic radius with increasing atomic number (also known as the lanthanide contraction). The resulting steric effects determine to a large extent the geometries of complexes of these ions. Here, we discuss these effects, particularly upon the properties of the complexes in aqueous solution, for selected families of Ln3+-complexes of oxycarboxylate and aminocarboxylate ligands. The physical properties of the cations are very different, which is very useful for the elucidation of the configuration, conformation and the dynamics of the complexes by X-ray techniques, NMR spectroscopy, and optical techniques. Often the structural analysis is assisted by computational methods
Effect of a halogenide substituent on the stability and photophysical properties of lanthanide triple-stranded helicates with ditopic ligands derived from bis(benzimidazolyl)pyridine
Mono- and bimetallic lanthanide(III) phenolic cryptates obtained by template reaction: solid state structure, photophysical properties and relaxivity
Mono- and bimetallic lanthanide(III) phenolic cryptates obtained by template reaction: solid state structure, photophysical properties and relaxivityââ
Distinct DNA methylomes of newborns and centenarians
Human aging cannot be fully understood in terms of the constrained genetic setting. Epigenetic drift is an alternative means of explaining age-associated alterations. To address this issue, we performed whole-genome bisulfite sequencing (WGBS) of newborn and centenarian genomes. The centenarian DNA had a lower DNA methylation content and a reduced correlation in the methylation status of neighboring cytosine--phosphate--guanine (CpGs) throughout the genome in comparison with the more homogeneously methylated newborn DNA. The more hypomethylated CpGs observed in the centenarian DNA compared with the neonate covered all genomic compartments, such as promoters, exonic, intronic, and intergenic regions. For regulatory regions, the most hypomethylated sequences in the centenarian DNA were present mainly at CpG-poor promoters and in tissue-specific genes, whereas a greater level of DNA methylation was observed in CpG island promoters. We extended the study to a larger cohort of newborn and nonagenarian samples using a 450,000 CpG-site DNA methylation microarray that reinforced the observation of more hypomethylated DNA sequences in the advanced age group. WGBS and 450,000 analyses of middle-age individuals demonstrated DNA methylomes in the crossroad between the newborn and the nonagenarian/centenarian groups. Our study constitutes a unique DNA methylation analysis of the extreme points of human life at a single-nucleotide resolution level
Gd(III) complexes intercalated into hydroxy double salts as potential MRI contrast agents
The ion exchange intercalation of two Gd-based magnetic resonance imaging contrast agents into hydroxy double salts (HDSs) is reported. The presence of Gd3+ diethylenetriaminepentaacetate and Gd3+ diethylenetriaminepenta(methylenephosphonate) complexes in the HDS lattice after intercalation was confirmed by microwave plasma-atomic emission spectroscopy. The structural aspects of the HDS-Gd composites were studied by X-ray diffraction, with the intercalates having an interlayer spacing of 14.5â18.6 Ă
. Infrared spectroscopy confirmed the presence of characteristic vibration peaks associated with the Gd3+ complexes in the intercalation compounds. The proton relaxivities of the Gd3+ complex-loaded composites were 2 to 5-fold higher in longitudinal relaxivity, and up to 10-fold higher in transverse relaxivity, compared to solutions of the pure complexes. These data demonstrate that the new composites reported here are potentially potent MRI contrast agents
A prospective study of the clinical outcomes and prognosis associated with comorbid COPD in the atrial fibrillation population
Background: Patients with COPD are at higher risk of presenting with atrial fibrillation (AF). Information about clinical outcomes and optimal medical treatment of AF in the setting of COPD remains missing. We aimed to describe the prevalence of COPD in a sizeable cohort of real-world AF patients belonging to the same healthcare area and to examine the relationship between comorbid COPD and AF prognosis. Methods: Prospective analysis performed in a specific healthcare area. Data were obtained from several sources within the "data warehouse of the Galician Healthcare Service" using multiple analytical tools. Statistical analyses were completed using SPSS 19 and STATA 14.0. Results: A total of 7,990 (2.08%) patients with AF were registered throughout 2013 in our healthcare area (n=348,985). Mean age was 76.83+/-10.51 years and 937 (11.7%) presented with COPD. COPD patients had a higher mean CHA2DS2-VASc (4.21 vs 3.46; P=0.02) and received less beta-blocker and more digoxin therapy than those without COPD. During a mean follow-up of 707+/-103 days, 1,361 patients (17%) died. All-cause mortality was close to two fold higher in the COPD group (28.3% vs 15.5%; P<0.001). Independent predictive factors for all-cause mortality were age, heart failure, diabetes, previous thromboembolic event, dementia, COPD, and oral anticoagulation (OA). There were nonsignificant differences in thromboembolic events (1.7% vs 1.5%; P=0.7), but the rate of hemorrhagic events was significantly higher in the COPD group (3.3% vs 1.9%; P=0.004). Age, valvular AF, OA, and COPD were independent predictive factors for hemorrhagic events. In COPD patients, age, heart failure, vasculopathy, lack of OA, and lack of beta-blocker use were independent predictive factors for all-cause mortality. Conclusion: AF patients with COPD have a higher incidence of adverse events with significantly increased rates of all-cause mortality and hemorrhagic events than AF patients without COPD. However, comorbid COPD was not associated with differences in cardiovascular death or stroke rate. OA and beta-blocker treatment presented a risk reduction in mortality while digoxin use exerted a neutral effect
2D Cu(I)-I Coordination Polymer with Smart Optoelectronic Properties and Photocatalytic Activity as a Versatile Multifunctional Material
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