1,237 research outputs found
Net electrophilicity as computational route for the choice of favorable ionic liquids in nanoparticle production
In the last years, the potential of using ionic liquids (IL)s as an
environment for nanoparticle (NP) synthesis has been demonstrated and in
particular, triggering NP formation in ILs by electron irradiation has been
reported as a very simple and clean route for NP production. Starting from the
recent evidence for a correlation between an IL's capability to support NP
production and the radiochemical instability of the IL's cation, we used
conceptual Density Functional Theory (DFT) to provide a pre-screening of a set
of different IL cations. The screened quantity is the net electrophilicity
which we suggest as possible measure of this instability. Therefore, our work
not only gives a measure for the likelihood of NP generation in different ILs,
but it also provides a model which can further be extended and applied to
obtain information about any other IL of interest. Moreover, our theoretical
approach outlines a strategy which may reduce a lengthy experimental
investigation for the identification of the most suitable IL for a particular
reaction.Comment: 12 pages, 11 figures, 2 tables (including SI
" Candidatus Mesochlamydia elodeae” (Chlamydiae: Parachlamydiaceae ), a novel chlamydia parasite of free-living amoebae
Vannella sp. isolated from waterweed Elodea sp. was found infected by a chlamydia-like organism. This organism behaves like a parasite, causing the death through burst of its host. Once the vannellae degenerated, the parasite was successfully kept in laboratory within a Saccamoeba sp. isolated from the same waterweed sample, which revealed in fine through electron microscopy to harbor two bacterial endosymbionts: the chlamydial parasite we introduce and another endosymbiont initially and naturally present in the host. Herein, we provide molecular-based identification of both the amoeba host and its two endosymbionts, with special focus on the chlamydia parasite. High sequence similarity values of the 18S rDNA permitted to assign the amoeba to the species Saccamoeba lacustris (Amoebozoa, Tubulinea). The bacterial endosymbiont naturally harbored by the host belonged to Sphingomonas koreensis (Alpha-Proteobacteria). The chlamydial parasite showed a strict specificity for Saccamoeba spp., being unable to infect a variety of other amoebae, including Acanthamoeba, and it was itself infected by a bacteriophage. Sequence similarity values of the 16S rDNA and phylogenetic analysis indicated that this strain is a new member of the family Parachlamydiaceae, for which we propose the name "Candidatus Mesochlamydia elodeae.
Complex translational regulation of BACE1 involves upstream AUGs and stimulatory elements within the 5′ untranslated region
BACE1 is the protease responsible for the production of amyloid-β peptides that accumulate in the brain of Alzheimer's disease (AD) patients. BACE1 expression is regulated at the transcriptional, as well as post-transcriptional level. Very high BACE1 mRNA levels have been observed in pancreas, but the protein and activity were found mainly in brain. An up-regulation of the protein has been described in some AD patients without a change in transcript levels. The features of BACE1 5′ untranslated region (5′ UTR), such as the length, GC content, evolutionary conservation and presence of upstream AUGs (uAUGs), indicate an important regulatory role of this 5′ UTR in translational control. We demonstrate that, in brain and pancreas, almost all of the native BACE1 mRNA contains the full-length 5′ UTR. RNA transfection and in vitro translation show that translation is mainly inhibited by the presence of the uAUGs. We provide a mutational analysis that highlight the second uAUG as the main inhibitory element while mutations of all four uAUGs fully de-repress translation. Furthermore, we have evidence that a sequence within the region 222-323 of the BACE1 5′ UTR has a stimulatory effect on translation that might depend on the presence of trans-acting factors
Molecular Identification of a Phage-infected Protochlamydia Strain Naturally Harboured by Non-Encysting Naegleria
A thermophilic strain of Naegleria clarki, isolated from a pond, has previously been investigated for its peculiarity to host a cytoplasmic symbiont, which causes a loss of the ability to form cysts. This endosymbiont, called Pcb, was itself infected by a phage, and exhibited chlamydia-like features resembling to another symbiont of Naegleria previously described as Protochlamydia naegleriophila. We report in this study, the results of amoeba host range and 16S rDNA molecular phylogeny of this strain, showing that Pcb is a new strain of the Naegleria endosymbiont chlamydial species Protochlamydia naegleriophila (Chlamydiae: Parachlamydiaceae)
Rockfall susceptibility analysis through 3D simulations in marine protected areas of the Portofino coastline: case studies of San Fruttuoso and Paraggi bays
The research focuses on the assessment of the potential geomorphological hazards affecting the stability of the Promontory of Portofino (Regional Natural Park of Portofino, Northern Italy), mainly on the bays of San Fruttuoso and Paraggi. The study area constitutes one of the most representative and most populated environments, both by locals and tourists, of the entire Liguria area. For this reason, there is a growing need for investigation on the natural dynamics of these landscapes, based on detailed topographic information. The research starts from a regional geological and geomorphological analysis specific to the study area, combined with a multi-model comparison algorithm (M3C2), which allows comparing two LiDAR datasets acquired in 2008 and 2020, respectively, to assess the overall dynamics of the promontory development. Then, a detailed study of San Fruttuoso and Paraggi bays, two key points for visitors and therefore for management, is performed. Three-dimensional modeling of rockfalls is carried out, which allows the development of a specific management oriented to the use of nature-based solutions (NBSs) strategies, respecting the environment and increasing safety against instability processes in these areas.This study has been carried out in the framework of a collaboration among ISPRA, GISIG, Universita di Genova, and Universidad del Pais Vasco (UPV/EHU, IT1678-22 Research Group, PES-18/92 Project) within the RECONECT Project (Regenerating ECOsystems with Nature-based solutions for hydro-meteorological risk rEduCTion)
Complete Genome Sequence of the Linear Plasmid pJD12 Hosted by Micrococcus sp. D12, Isolated from a High-Altitude Volcanic Lake in Argentina
The linear plasmid pDJ12 from Micrococcus D12, isolated from the high-altitude volcanic Diamante Lake in the northwest of Argentina, was completely sequenced and annotated. It is noteworthy that the element is probably conjugative and harbors genes potentially instrumental in coping with stress conditions that prevail in such an extreme environmentFil: Dib, Julian Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Angelov, Angel. Technische Universitat Munchen; AlemaniaFil: Liebl, Wolfang. Technische Universitat Munchen; AlemaniaFil: Döbber, Johannes. Westfalische Wilhelms Universitat; AlemaniaFil: Voget, Sonja. Georg-August University; AlemaniaFil: Schuldes, Jörg. Georg-August University; AlemaniaFil: Gorriti, Marta Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); ArgentinaFil: Meinhardt, Friedhelm. Westfalische Wilhelms Universitat; AlemaniaFil: Daniele, Rolf. Georg-August University; Alemani
Microsporidia-like parasites of amoebae belong to the early fungal lineage Rozellomycota
Molecular phylogenies based on the small subunit ribosomal RNA gene (SSU or 18S ribosomal DNA (rDNA)) revealed recently the existence of a relatively large and widespread group of eukaryotes, branching at the base of the fungal tree. This group, comprising almost exclusively environmental clones, includes the endoparasitic chytrid Rozella as the unique known representative. Rozella emerged as the first fungal lineage in molecular phylogenies and as the sister group of the Microsporidia. Here we report rDNA molecular phylogenetic analyses of two endonuclear parasites of free-living naked amoebae having microsporidia-like ultrastructural features but belonging to the rozellids. Similar to microsporidia, these endoparasites form unflagellated walled spores and grow inside the host cells as unwalled nonphagotrophic meronts. Our endonuclear parasites are microsporidia-like rozellids, for which we propose the name Paramicrosporidium, appearing to be the until now lacking morphological missing link between Fungi and Microsporidia. These features contrast with the recent description of the rozellids as an intermediate wall-less lineage of organisms between protists and true Fungi. We thus reconsider the rozellid clade as the most basal fungal lineage, naming it Rozellomycota
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