2,744 research outputs found
Spin wave vortex from the scattering on Bloch point solitons
The interaction of a spin wave with a stationary Bloch point is studied. The
topological non-trivial structure of the Bloch point manifests in the
propagation of spin waves endowing them with a gauge potential that resembles
the one associated with the interaction of a magnetic monopole and an electron.
By pursuing this analogy, we are led to the conclusion that the scattering of
spin waves and Bloch points is accompanied by the creation of a magnon vortex.
Interference between such a vortex and a plane wave leads to dislocations in
the interference pattern that can be measurable by means of magnon holography
Development of a fast screening method for the direct determination of chlorinated persistent organic pollutants in fish oil by high-resolution continuum source graphite furnace molecular absorption spectrometry
The authors are grateful to the Conselho Nacional de Desenvolvimento Científico and Tecnológico (CNPq); the present research was mostly financed through Project no. CNPq 406877/2013-0. The authors are also grateful to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for financial support and scholarships, and to Analytik Jena for financial support and donation of the contrAA 600 high-resolution continuum source atomic absorption spectrometer.Peer reviewedPostprin
Economic–Sanitation–Environmental (Dis)Connections in Brazil: A Trans-Scale Perspective From Minas Gerais State and BH Microregion
Brazil’s economic, environmental, and infrastructural landscape is characterised by local and regional inequalities, particularly evident in Minas Gerais state and the municipalities surrounding its capital, Belo Horizonte (BH) microregion. This research examines three primary domains: (a) economic metrics such as GDP per capita, wages, and formal employment; (b) the availability of clean water and sewage systems; and (c) the frequency of emergency decrees. It aims to ascertain whether these factors can delineate economic, health, and socio-environmental divides within the BH microregion and between its urban and rural areas. Economically, a pronounced gap exists between GDP growth and wage stability, underscoring disparities between the BH microregion and the broader state. While the BH microregion boasts higher salaries and GDP, it also grapples with a heightened cost of living. Disparities in water and sewage infrastructure are stark between urban and non-urban locales, with the latter often lacking access. Emergency decrees are correlated with municipal GDP, with lower-GDP areas experiencing more crises, albeit to a lesser extent in the BH microregion. Cluster analysis reveals a nexus between frequent emergencies, lower GDP, and improved access to water and sewage services. Addressing these challenges requires comprehensive public policies to foster local well-being and alleviate economic, infrastructural, and environmental disparities within both the state and the BH microregion
Evolutionary history, biogeography, and a new species of Sphoeroides (Tetraodontiformes: Tetraodontidae): how the major biogeographic barriers of the Atlantic Ocean shaped the evolution of a pufferfish genus
ABSTRACT: Tetraodontidae is the most speciose family of Tetraodontiformes and is represented by fish popularly known as pufferfishes. They are characterized by modified jaws with four dental plates and the ability to inflate their bodies. Tetraodontids are distributed throughout the world and have a wide range of habitat use. One of its genera, Sphoeroides, shows a biogeographical pattern, with 19 of its 21 species restricted to coastal regions of the Americas. Although represented in large-scale phylogenies, the evolutionary history and biogeography of the genus have not been explored in detail. The present study aims to understand the historical and biogeographic processes that shaped the evolutionary history of Sphoeroides. Including samples from all biogeographic regions of its occurrence, we reconstruct a phylogenetic/biogeographic history hypothesis for the genus. Our results show that Sphoeroides is a paraphyletic group comprising Colomesus; indicate a central role of the biogeographic barriers of the Atlantic Ocean in the diversification of the genus; and identified a cryptic species in Brazilian waters, formally known as S. spengleri, described here through integrative taxonomy. We also propose nomenclatural changes given the position of Colomesus deeply nested within Sphoeroides.info:eu-repo/semantics/publishedVersio
MKP-1 mediates glucocorticoid-induced ERK1/2 dephosphorylation and reduction in pancreatic beta-cell proliferation in islets from early lactating mothers
Maternal pancreatic islets undergo a robust increase of mass and proliferation during pregnancy, which allows a compensation of gestational insulin resistance. Studies have described that this adaptation switches to a low proliferative status after the delivery. the mechanisms underlying this reversal are unknown, but the action of glucocorticoids (GCs) is believed to play an important role because GCs counteract the pregnancy-like effects of PRL on isolated pancreatic islets maintained in cell culture. Here, we demonstrate that ERK1/2 phosphorylation (phospho-ERK1/2) is increased in maternal rat islets isolated on the 19th day of pregnancy. Phospho-ERK1/2 status on the 3rd day after delivery (L3) rapidly turns to values lower than that found in virgin control rats (CTL). MKP-1, a protein phosphatase able to dephosphorylate ERK1/2, is increased in islets from L3 rats. Chromatin immunoprecipitation assay revealed that binding of glucocorticoid receptor (GR) to MKP-1 promoter is also increased in islets from L3 rats. in addition, dexamethasone (DEX) reduced phospho-ERK1/2 and increased MKP-1 expression in RINm5F and MIN-6 cells. Inhibition of transduction with cycloheximide and inhibition of phosphatases with orthovanadate efficiently blocked DEX-induced downregulation of phospho-ERK1/2. in addition, specific knockdown of MKP-1 with siRNA suppressed the downregulation of phosphoERK1/2 and the reduction of proliferation induced by DEX. Altogether, our results indicate that downregulation of phospho-ERK1/2 is associated with reduction in proliferation found in islets of early lactating mothers. This mechanism is probably mediated by GC-induced MKP-1 expression.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de PesquisaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ São Paulo, Inst Biomed Sci, Dept Physiol & Biophys, BR-05508 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biol Sci, Diadema, SP, BrazilUniv Estadual Campinas, Fac Med Sci, Dept Pharmacol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biol Sci, Diadema, SP, BrazilWeb of Scienc
R534C mutation in hERG causes a trafficking defect in iPSC-derived cardiomyocytes from patients with type 2 long QT syndrome
Patient-specific cardiomyocytes obtained from induced pluripotent stem cells (CM-iPSC) offer unprecedented mechanistic insights in the study of inherited cardiac diseases. The objective of this work was to study a type 2 long QT syndrome (LQTS2)-associated mutation (c.1600C > T in KCNH2, p.R534C in hERG) in CM-iPSC. Peripheral blood mononuclear cells were isolated from two patients with the R534C mutation and iPSCs were generated. In addition, the same mutation was inserted in a control iPSC line by genome editing using CRISPR/Cas9. Cells expressed pluripotency markers and showed spontaneous differentiation into the three embryonic germ layers. Electrophysiology demonstrated that action potential duration (APD) of LQTS2 CM-iPSC was significantly longer than that of the control line, as well as the triangulation of the action potentials (AP), implying a longer duration of phase 3. Treatment with the IKr inhibitor E4031 only caused APD prolongation in the control line. Patch clamp showed a reduction of IKr on LQTS2 CM-iPSC compared to control, but channel activation was not significantly affected. Immunofluorescence for hERG demonstrated perinuclear staining in LQTS2 CM-iPSC. In conclusion, CM-iPSC recapitulated the LQTS2 phenotype and our findings suggest that the R534C mutation in KCNH2 leads to a channel trafficking defect to the plasma membrane.Fil: Mesquita, Fernanda C. P.. Universidade Federal do Rio de Janeiro; BrasilFil: Arantes, Paulo C.. Universidade Federal do Rio de Janeiro; BrasilFil: Kasai Brunswick, Tais H.. Universidade Federal do Rio de Janeiro; BrasilFil: Araujo, Dayana S.. Universidade Federal do Rio de Janeiro; BrasilFil: Gubert, Fernanda. Universidade Federal do Rio de Janeiro; BrasilFil: Monnerat, Gustavo. Universidade Federal do Rio de Janeiro; BrasilFil: Silva dos Santos, Danúbia. Universidade Federal do Rio de Janeiro; BrasilFil: Neiman, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Leitão, Isabela C.. Universidade Federal do Rio de Janeiro; BrasilFil: Barbosa, Raiana A. Q.. Universidade Federal do Rio de Janeiro; BrasilFil: Coutinho, Jorge L.. National Institute Of Cardiology; BrasilFil: Vaz, Isadora M.. Pontificia Universidad Catolica de Parana; BrasilFil: dos Santos, Marcus N.. Universidade Federal do Rio de Janeiro; BrasilFil: Borgonovo, Tamara. Pontificia Universidad Catolica de Parana; BrasilFil: Cruz, Fernando E. S.. National Institute of Cardiology; BrasilFil: Miriuka, Santiago Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Medei, Emiliano H.. Universidade Federal do Rio de Janeiro; BrasilFil: Campos de Carvalho, Antonio C.. Universidade Federal do Rio de Janeiro; Brasil. National Institute of Cardiology; Brasil. National Institute for Science and Technology in Regenerative Medicine; BrasilFil: Carvalho, Adriana B.. Universidade Federal do Rio de Janeiro; Brasil. National Institute for Science and Technology in Regenerative Medicine; Brasi
Visualization of membrane loss during the shrinkage of giant vesicles under electropulsation
We study the effect of permeabilizing electric fields applied to two
different types of giant unilamellar vesicles, the first formed from EggPC
lipids and the second formed from DOPC lipids. Experiments on vesicles of both
lipid types show a decrease in vesicle radius which is interpreted as being due
to lipid loss during the permeabilization process. We show that the decrease in
size can be qualitatively explained as a loss of lipid area which is
proportional to the area of the vesicle which is permeabilized. Three possible
mechanisms responsible for lipid loss were directly observed: pore formation,
vesicle formation and tubule formation.Comment: Final published versio
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