629 research outputs found
Anotação semùntica de dados geoespaciais para a agricultura.
Dados geoespaciais sĂŁo base para sistemas de decisĂŁo em vĂĄrios domĂnios. Para serem usados esses dados precisam ser analisados e interpretados por especialistas. Essas interpretaçÔes geralmente nĂŁo sĂŁo armazenadas ou correspondem apenas a alguma informação textual e em linguagem prĂłpria, gravadas em arquivos tĂ©cnicos. A ausĂȘncia de soluçÔes eficientes para armazenĂĄ-las leva a problemas como retrabalho e dificuldades de compartilhamento de informação. Este trabalho apresenta uma solução para esse problema que baseia-se no uso de anotaçÔes semĂąnticas, uma abordagem que promove um entendimento comum dos conceitos usados. Com a adoção de workflows cientĂficos e tambĂ©m de um esquema de metadados e de ontologias bem conhecidos, foi especificado e parcialmente implementado um framework para anotação semĂąntica de dados geoespaciais, focando na solução de problemas em agricultura.bitstream/item/32414/1/BolPesq25.pd
Does sars-cov-2 trigger stress-induced autoimmunity by molecular mimicry? A hypothesis
Viruses can generate molecular mimicry phenomena within their hosts. Why should severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) not be considered one of these? Information in this short review suggests that it might be so and, thus, encourages research aiming at testing this possibility. We propose, as a working hypothesis, that the virus induces antibodies and that some of them crossreact with hostâs antigens, thus eliciting autoimmune phenomena with devasting consequences in various tissues and organs. If confirmed, by in vitro and in vivo tests, this could drive researchers to find effective treatments against the virus
Functions and Therapeutic Potential of Extracellular Hsp60, Hsp70, and Hsp90 in Neuroinflammatory Disorders
Neuroinflammation is implicated in central nervous system (CNS) diseases, but the molecular mechanisms involved are poorly understood. Progress may be accelerated by developing a comprehensive view of the pathogenesis of CNS disorders, including the immune and the chaperone systems (IS and CS). The latter consists of the molecular chaperones; cochaperones; and chaperone cofactors, interactors, and receptors of an organism and its main collaborators in maintaining protein homeostasis (canonical function) are the ubiquitin-proteasome system and chaperone-mediated autophagy. The CS has also noncanonical functions, for instance, modulation of the IS with induction of proinflammatory cytokines. This deserves investigation because it may be at the core of neuroinflammation, and elucidation of its mechanism will open roads toward developing efficacious treatments centered on molecular chaperones (i.e., chaperonotherapy). Here, we discuss information available on the role of three members of the CS-heat shock protein (Hsp)60, Hsp70, and Hsp90-in IS modulation and neuroinflammation. These three chaperones occur intra- and extracellularly, with the latter being the most likely involved in neuroinflammation because they can interact with the IS. We discuss some of the interactions, their consequences, and the molecules involved but many aspects are still incompletely elucidated, and we hope that this review will encourage research based on the data presented to pave the way for the development of chaperonotherapy. This may consist of blocking a chaperone that promotes destructive neuroinflammation or replacing or boosting a defective chaperone with cytoprotective activity against neurodegeneration
Probability distributions of radiocarbon in open linear compartmental systems at steady-state
153 MHz GMRT follow-up of steep-spectrum diffuse emission in galaxy clusters
In this paper we present new high sensitivity 153 MHz Giant Meterwave Radio
Telescope follow-up observations of the diffuse steep spectrum cluster radio
sources in the galaxy clusters Abell 521, Abell 697, Abell 1682. Abell 521
hosts a relic, and together with Abell 697 it also hosts a giant very steep
spectrum radio halo. Abell 1682 is a more complex system with candidate steep
spectrum diffuse emission. We imaged the diffuse radio emission in these
clusters at 153 MHz, and provided flux density measurements of all the sources
at this frequency. Our new flux density measurements, coupled with the existing
data at higher frequencies, allow us to study the total spectrum of the halos
and relic over at least one order of magnitude in frequency. Our images confirm
the presence of a very steep "diffuse component" in Abell 1682. We found that
the spectrum of the relic in Abell 521 can be fitted by a single power-law with
from 153 MHz to 5 GHz. Moreover, we confirm that the halos
in Abell 521 and Abell 697 have a very steep spectrum, with
and respectively. Even with the inclusion of the 153 MHz
flux density information it is impossible to discriminate between power-law and
curved spectra, as derived from homogeneous turbulent re-acceleration. The
latter are favored on the basis of simple energetic arguments, and we expect
that LOFAR will finally unveil the shape of the spectra of radio halos below
100 MHz, thus providing clues on their origin.Comment: 11 pages, 6 figures, 3 tables, accepted for publication in A&
The challenging riddle about the janusâtype role of hsp60 and related extracellular vesicles and miRNAs in carcinogenesis and the promises of its solution
Hsp60 is one of the most ancient and evolutionarily conserved members of the chaperoning system. It typically resides within mitochondria, in which it contributes to maintaining the organelleâs proteome integrity and homeostasis. In the last few years, it has been shown that Hsp60 also occurs in other locations, intracellularly and extracellularly, including cytosol, plasmacell membrane, and extracellular vesicles (EVs). Consequently, nonâcanonical functions and interacting partners of Hsp60 have been identified and it has been realized that it is a hub molecule in diverse networks and pathways and that it is implicated, directly or indirectly, in the development of various pathological conditions, the Hsp60 chaperonopathies. In this review, we will focus on the multiâfaceted role of this chaperonin in human cancers, showing the contribution of intraâ and extracellular Hsp60 in cancer development and progression, as well as the impact of miRNAâmediated regulation of Hsp60 in carcinogenesis. There are still various aspects of this intricate biological scenario that are poorly understood but ongoing research is steadily providing new insights and we will direct attention to them. For instance, we will highlight the possible applications of the Hsp60 involvement in carcinogenesis not only in diagnosis, but also in the development of specific antiâcancer therapies centered on the use of the chaperonin as therapeutic target or agent and depending on its role, proâ or antiâtumor
Molecular chaperones and thyroid cancer
Thyroid cancers are the most common of the endocrine system malignancies and progress must be made in the areas of differential diagnosis and treatment to improve patient management. Advances in the understanding of carcinogenic mechanisms have occurred in various fronts, including studies of the chaperone system (CS). Components of the CS are found to be quantitatively increased or decreased, and some correlations have been established between the quantitative changes and tumor type, prognosis, and response to treatment. These correlations provide the basis for identi-fying distinctive patterns useful in differential diagnosis and for planning experiments aiming at elucidating the role of the CS in tumorigenesis. Here, we discuss studies of the CS components in various thyroid cancers (TC). The chaperones belonging to the families of the small heat-shock proteins Hsp70 and Hsp90 and the chaperonin of Group I, Hsp60, have been quantified mostly by immunohistochemistry and Western blot in tumor and normal control tissues and in extracellular vesicles. Distinctive differences were revealed between the various thyroid tumor types. The most frequent finding was an increase in the chaperones, which can be attributed to the augmented need for chaperones the tumor cells have because of their accelerated metabolism, growth, and division rate. Thus, chaperones help the tumor cell rather than protect the patient, exemplifying chaperonopathies by mistake or collaborationism. This highlights the need for research on chaperonotherapy, namely the development of means to eliminate/inhibit pathogenic chaperones
How Aromatic Fluorination Exchanges the Interaction Role of Pyridine with Carbonyl Compounds: The Formaldehyde Adduct
The rotational spectrum of the weakly bound complex pentafluoropyridineâ
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formaldehyde has been investigated using Fourier transform microwave spectroscopy. From the analysis of the rotational parameters of the parent species and of the 13C and 15N isotopologues, the structural arrangement of the adduct has been unambiguously established. The full ring fluorination of pyridine has a dramatic effect on its binding properties: It alters the electron density distribution at the Ï-cloud of pyridine creating a Ï-hole and changing its electron donor-acceptor capabilities. In the complex, formaldehyde lies above the aromatic ring with one of the oxygen lone pairs, as conventionally envisaged, pointing toward its centre. This lone pairâ
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Ï-hole interaction, reinforced by a weak CâHâ
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N interaction, indicates an exchange of the electron-acceptor roles of both molecules when compared to the pyridineâ
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formaldehyde adduct. Tunnelling doublets due to the internal rotation of formaldehyde have also been observed and analysed leading to a discussion on the competition between lone pairâ
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Ï-hole and Ïâ
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Ï stacking interactions
Hsp60 Post-translational Modifications: Functional and Pathological Consequences
Hsp60 is a chaperone belonging to the Chaperonins of Group I and typically functions inside mitochondria in which, together with the co-chaperonin Hsp10, maintains protein homeostasis. In addition to this canonical role, Hsp60 plays many others beyond the mitochondria, for instance in the cytosol, plasma-cell membrane, extracellular space, and body fluids. These non-canonical functions include participation in inflammation, autoimmunity, carcinogenesis, cell replication, and other cellular events in health and disease. Thus, Hsp60 is a multifaceted molecule with a wide range of cellular and tissue locations and functions, which is noteworthy because there is only one hsp60 gene. The question is by what mechanism this protein can become multifaceted. Likely, one factor contributing to this diversity is post-translational modification (PTM). The amino acid sequence of Hsp60 contains many potential phosphorylation sites, and other PTMs are possible such as O-GlcNAcylation, nitration, acetylation, S-nitrosylation, citrullination, oxidation, and ubiquitination. The effect of some of these PTMs on Hsp60 functions have been examined, for instance phosphorylation has been implicated in sperm capacitation, docking of H2B and microtubule-associated proteins, mitochondrial dysfunction, tumor invasiveness, and delay or facilitation of apoptosis. Nitration was found to affect the stability of the mitochondrial permeability transition pore, to inhibit folding ability, and to perturb insulin secretion. Hyperacetylation was associated with mitochondrial failure; S-nitrosylation has an impact on mitochondrial stability and endothelial integrity; citrullination can be pro-apoptotic; oxidation has a role in the response to cellular injury and in cell migration; and ubiquitination regulates interaction with the ubiquitin-proteasome system. Future research ought to determine which PTM causes which variations in the Hsp60 molecular properties and functions, and which of them are pathogenic, causing chaperonopathies. This is an important topic considering the number of acquired Hsp60 chaperonopathies already cataloged, many of which are serious diseases without efficacious treatment
The triad hsp60-mirnas-extracellular vesicles in brain tumors: Assessing its components for understanding tumorigenesis and monitoring patients
Brain tumors have a poor prognosis and progress must be made for developing efficacious treatments, but for this to occur their biology and interaction with the host must be elucidated beyond current knowledge. What has been learned from other tumors may be applied to study brain tumors, for example, the role of Hsp60, miRNAs, and extracellular vesicles (EVs) in the mechanisms of cell proliferation and dissemination, and resistance to immune attack and anticancer drugs. It has been established that Hsp60 increases in cancer cells, in which it occurs not only in the mitochondria but also in the cytosol and plasma-cell membrane and it is released in EVs into the extracellular space and in circulation. There is evidence suggesting that these EVs interact with cells near and far from their original cell and that this interaction has an impact on the functions of the target cell. It is assumed that this crosstalk between cancer and host cells favors carcinogenesis in various ways. We, therefore, propose to study the triad Hsp60-related miRNAs-EVs in brain tumors and have standardized methods for the purpose. These revealed that EVs with Hsp60 and related miRNAs increase in patientsâ blood in a manner that reflects disease status. The means are now available to monitor brain tumor patients by measuring the triad and to dissect its effects on target cells in vitro, and in experimental models in vivo
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