2,237 research outputs found
(−)-Kolavenic acid
In the two, almost identical, molecules in the asymmetric unit of the title compound [systematic name: (E)-3-methyl-5-(1,2,4a,5-tetramethyl-1,2,3,4,4a,7,8,8a-octahydronaphthalen-1-yl)pent-2-enoic acid], C20H32O2, the rings are trans fused. The cyclohexane ring has a chair conformation and the cyclohexene ring a distorted half-boat conformation. The two independent molecules are connected into a dimer via O—H⋯O hydrogen bonds. The dimers are associated into supramolecular chains along c via C—H⋯O contacts
Protein Disulfide Isomerase and Host-Pathogen Interaction
Reactive oxygen species (ROS) production by immunological cells is known to cause damage to pathogens. Increasing evidence accumulated in the last decade has shown, however, that ROS (and redox signals) functionally regulate different cellular pathways in the host-pathogen interaction. These especially affect (i) pathogen entry through protein redox switches and redox modification (i.e., intra- and interdisulfide and cysteine oxidation) and (ii) phagocytic ROS production via Nox family NADPH oxidase enzyme and the control of phagolysosome function with key implications for antigen processing. The protein disulfide isomerase (PDI) family of redox chaperones is closely involved in both processes and is also implicated in protein unfolding and trafficking across the endoplasmic reticulum (ER) and towards the cytosol, a thiol-based redox locus for antigen processing. Here, we summarise examples of the cellular association of host PDI with different pathogens and explore the possible roles of pathogen PDIs in infection. A better understanding of these complex regulatory steps will provide insightful information on the redox role and coevolutional biological process, and assist the development of more specific therapeutic strategies in pathogen-mediated infections
Molybdenum (VI) binded to humic and nitrohumic acid models in aqueous solutions. Salicylic, 3-nitrosalicylic, 5-nitrosalicylic and 3,5 dinitrosalicylic acids: part 2
Antiproliferative activity of synthetic fatty acid amides from renewable resources
AbstractIn the work, the in vitro antiproliferative activity of a series of synthetic fatty acid amides were investigated in seven cancer cell lines. The study revealed that most of the compounds showed antiproliferative activity against tested tumor cell lines, mainly on human glioma cells (U251) and human ovarian cancer cells with a multiple drug-resistant phenotype (NCI-ADR/RES). In addition, the fatty methyl benzylamide derived from ricinoleic acid (with the fatty acid obtained from castor oil, a renewable resource) showed a high selectivity with potent growth inhibition and cell death for the glioma cell line—the most aggressive CNS cancer
Multiple origins of green coloration in frogs mediated by a novel biliverdin-binding serpin
Many vertebrates have distinctive blue-green bones and other tissues due to unusually high biliverdin concentrations—a phenomenon called chlorosis. Despite its prevalence, the biochemical basis, biology, and evolution of chlorosis are poorly understood. In this study, we show that the occurrence of high biliverdin in anurans (frogs and toads) has evolved multiple times during their evolutionary history, and relies on the same mechanism—the presence of a class of serpin family proteins that bind biliverdin. Using a diverse combination of techniques, we purified these serpins from several species of nonmodel treefrogs and developed a pipeline that allowed us to assemble their complete amino acid and nucleotide sequences. The described proteins, hereafter named biliverdinbinding serpins (BBS), have absorption spectra that mimic those of phytochromes and bacteriophytochromes. Our models showed that physiological concentration of BBSs fine-tune the color of the animals, providing the physiological basis for crypsis in green foliage even under near-infrared light. Additionally, we found that these BBSs are most similar to human glycoprotein alpha-1-antitrypsin, but with a remarkable functional diversification. Our results present molecular and functional evidence of recurrent evolution of chlorosis, describe a biliverdin-binding protein in vertebrates, and introduce a function for a member of the serpin superfamily, the largest and most ubiquitous group of protease inhibitors.Fil: Taboada, Carlos Alberto. University of Duke; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidade de Sao Paulo; BrasilFil: Brunetti, Andrés Eduardo. Universidade de Sao Paulo; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; ArgentinaFil: Lucio Lyra, Mariana. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fitak, Robert R.. University of Duke; Estados Unidos. University of Central Florida; Estados UnidosFil: Faigon Soverna, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Ron, Santiago R.. Pontificia Universidad Católica del Ecuador; EcuadorFil: Lagorio, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Inorgánica, Analítica y Química Física; ArgentinaFil: Baptista Haddad, Célio Fernando. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Peporine Lopes, Norberto. Universidade de Sao Paulo; BrasilFil: Johnsen, Sönke. University of Duke; Estados UnidosFil: Faivovich, Julián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Chemes, Lucia Beatriz. Universidad Nacional de San Martín; ArgentinaFil: Bari, Sara Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin
The Luminosity Function of the NoSOCS Galaxy Cluster Sample
We present the analysis of the luminosity function of a large sample of
galaxy clusters from the Northern Sky Optical Cluster Survey, using latest data
from the Sloan Digital Sky Survey. Our global luminosity function (down to
M_r<= -16) does not show the presence of an upturn at faint magnitudes, while
we do observe a strong dependence of its shape on both richness and
cluster-centric radius, with a brightening of M^* and an increase of the dwarf
to giant ratio with richness, indicating that more massive systems are more
efficient in creating/retaining a population of dwarf satellites. This is
observed both within physical (0.5 R_200) and fixed (0.5 Mpc) apertures,
suggesting that the trend is either due to a global effect, operating at all
scales, or to a local one but operating on even smaller scales. We further
observe a decrease of the relative number of dwarf galaxies towards the cluster
center; this is most probably due to tidal collisions or collisional disruption
of the dwarfs since merging processes are inhibited by the high velocity
dispersions in cluster cores and, furthermore, we do not observe a strong
dependence of the bright end on the environment. We find indication that the
dwarf to giant ratio decreases with increasing redshift, within 0.07<z<0.2. We
also measure a trend for stronger suppression of faint galaxies (below M^*+2)
with increasing redshift in poor systems, with respect to more massive ones,
indicating that the evolutionary stage of less massive galaxies depends more
critically on the environment. Finally we point out that the luminosity
function is far from universal; hence the uncertainties introduced by the
different methods used to build a composite function may partially explain the
variety of faint-end slopes reported in the literature as well as, in some
cases, the presence of a faint-end upturn.Comment: 16 pages, 12 figures. Accepted for publication in MNRA
Genetic comparison of sickle cell anaemia cohorts from Brazil and the United States reveals high levels of divergence
Genetic analysis of admixed populations raises special concerns with regard to study design and data processing, particularly to avoid population stratification biases. The point mutation responsible for sickle cell anaemia codes for a variant hemoglobin, sickle hemoglobin or HbS, whose presence drives the pathophysiology of disease. Here we propose to explore ancestry and population structure in a genome-wide study with particular emphasis on chromosome 11 in two SCA admixed cohorts obtained from urban populations of Brazil (Pernambuco and Sao Paulo) and the United States (Pennsylvania). Ancestry inference showed different proportions of European, African and American backgrounds in the composition of our samples. Brazilians were more admixed, had a lower African background (43% vs. 78% on the genomic level and 44% vs. 76% on chromosome 11) and presented a signature of positive selection and Iberian introgression in the HbS region, driving a high differentiation of this locus between the two cohorts. The genetic structures of the SCA cohorts from Brazil and US differ considerably on the genome-wide, chromosome 11 and HbS mutation locus levels9CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP8367/2011-1; 150398/2013-1; 304455/2012-1; 310938/2014-7; 305218/2017-48367/2011-1; 150398/2013-1; 304455/2012-1; 310938/2014-7; 305218/2017-42008/57441-0; 2014/00984-3; 2012/06438-5; 2015/13152-9; 2008/10596-
O sapo dourado do arquivo pessoal de Mário de Andrade analisado com o método não destrutivo de fluorescência de raios X
Peri-personal space encoding in patients with disorders of consciousness and cognitive-motor dissociation
Behavioral assessments of consciousness based on overt command following cannot differentiate patients with disorders of consciousness (DOC) from those who demonstrate a dissociation between intent/awareness and motor capacity: cognitive motor dissociation (CMD). We argue that delineation of peri-personal space (PPS) – the multisensory-motor space immediately surrounding the body – may differentiate these patients due to its central role in mediating human-environment interactions, and putatively in scaffolding a minimal form of selfhood. In Experiment 1, we determined a normative physiological index of PPS by recording electrophysiological (EEG) responses to tactile, auditory, or audio-tactile stimulation at different distances (5 vs. 75 cm) in healthy volunteers (N = 19). Contrasts between paired (AT) and summed (A + T) responses demonstrated multisensory supra-additivity when AT stimuli were presented near, i.e., within the PPS, and highlighted somatosensory-motor sensors as electrodes of interest. In Experiment 2, we recorded EEG in patients behaviorally diagnosed as DOC or putative CMD (N = 17, 30 sessions). The PPS-measure developed in Experiment 1 was analyzed in relation with both standard clinical diagnosis (i.e., Coma Recovery Scale; CRS-R) and a measure of neural complexity associated with consciousness. Results demonstrated a significant correlation between the PPS measure and neural complexity, but not with the CRS-R, highlighting the added value of the physiological recordings. Further, multisensory processing in PPS was preserved in putative CMD but not in DOC patients. Together, the findings suggest that indexing PPS allows differentiating between groups of patients whom both show overt motor impairments (DOC and CMD) but putatively distinct levels of awareness or motor intent
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