171 research outputs found
Synthetic analogue of the natural product piperlongumine as a potent inhibitor of breast cancer cell line migration
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORPiperlongumine is a natural amide alkaloid isolated from several species of Piper and is described in the literature as selectively cytotoxic to several cancer cell lines. Inhibiting cell migration has gained considerable interest as an approach for disco283475484FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR2013/07600-32003/02176-72010/52327-52010/17329-72010/06741-42007/56140-4SEM INFORMAÇÃOSEM INFORMAÇÃOThis work was supported by the State of São Paulo Research Foundation (FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo), grant No. 2013/07600-3; Biota-FAPESP, grant No. 2003/02176-7; SISBIOTA-CNPq-FAPESP, grant No. 2010/52327-5; Coordenação
Precise phylogenetic analysis of microbial isolates and genomes from metagenomes using PhyloPhlAn 3.0
Microbial genomes are available at an ever-increasing pace, as cultivation and sequencing become cheaper and obtaining metagenome-assembled genomes (MAGs) becomes more effective. Phylogenetic placement methods to contextualize hundreds of thousands of genomes must thus be efficiently scalable and sensitive from closely related strains to divergent phyla. We present PhyloPhlAn 3.0, an accurate, rapid, and easy-to-use method for large-scale microbial genome characterization and phylogenetic analysis at multiple levels of resolution. PhyloPhlAn 3.0 can assign genomes from isolate sequencing or MAGs to species-level genome bins built from >230,000 publically available sequences. For individual clades of interest, it reconstructs strain-level phylogenies from among the closest species using clade-specific maximally informative markers. At the other extreme of resolution, it scales to large phylogenies comprising >17,000 microbial species. Examples including Staphylococcus aureus isolates, gut metagenomes, and meta-analyses demonstrate the ability of PhyloPhlAn 3.0 to support genomic and metagenomic analyses
Eight basic principles for the elaboration of public policies and development projects for the Pantanal.
Abstract: The Pantanal is considered the largest continuous freshwater wetland in the world, and its sustainable use requires a unified conceptual framework. The lengthy process to establish public policies has contributed to the increasing vulnerability of the Pantanal. Given the need for a conceptual basis to help this process, we elaborate a list of eight basic principles based on the accumulated scientific evidence: (i) Consider the Paraguay River Basin a management unity; (ii) Establish rules that follow the concept of restricted use approach; (iii) Ensure the ecologically sustainable use of the Pantanal; (iv) Maintain the environmental heterogeneity and functionality in the Pantanal landscapes; (v) Maintain the hydrological integrity and connectivity; (vi) Ensure the environmental representativeness of the protected areas network; (vii) Provide economic incentives for conservationist use of the land; and (viii) Recognize and protect traditional people, their values, resources, and way of living. However, the elaboration of public policies should be a participatory and inclusive decision‐making process towards a more just and sustainable future.Online first
Recurrent dynamical symmetry breaking and restoration by Wilson lines at finite densities on a torus
In this paper we derive the general expression of a one-loop effective
potential of the nonintegrable phases of Wilson lines for an SU(N) gauge theory
with a massless adjoint fermion defined on the spactime manifold
at finite temperature and fermion density. The Phase
structure of the vacuum is presented for the case with and N=2 at zero
temperature. It is found that gauge symmetry is broken and restored alternately
as the fermion density increases, a feature not found in the Higgs mechanism.
It is the manifestation of the quantum effects of the nonintegrable phases.Comment: 17 pages, 2 figure
Chemical, Structural, and Morphological Changes of a MoVTeNb Catalyst during Oxidative Dehydrogenation of Ethane
MoVTeNb mixed oxide, a highly active and
selective catalyst for the oxidative dehydrogenation of ethane to
produce ethylene, exhibits the so-called M1 and M2 crystalline
phases. The thermal stability of the MoVTeNb catalytic system
was assessed under varying reaction conditions; to this end, the
catalyst was exposed to several reaction temperatures spanning
from 440 to 550 °C. Both the pristine and spent materials were
analyzed by several characterization techniques. The catalyst
was stable below 500 °C; a reaction temperature of ≥500 °C
brings about the removal of tellurium from the intercalated
framework channels of the M1 crystalline phase. Rietveld
refinement of X-ray diffraction patterns and microscopy results showed that the tellurium loss causes the progressive partial
destruction of the M1 phase, thus decreasing the number of active sites and forming a MoO2 crystalline phase, which is inactive
for this reaction. Raman spectroscopy confirmed the MoO2 phase development as a function of reaction temperature. From highresolution
transmission electron microscopy and energy-dispersive X-ray spectroscopy analyses it was noticed that tellurium
departure occurs preferentially from the end sides of the needlelike M1 crystals, across the [001] plane. Detailed analysis of a
solid deposited at the reactor outlet showrf that it consisted mainly of metallic tellurium, suggesting that the tellurium
detachment occurs via reduction of Te4+ to Te0 due to a combination of reaction temperature and feed composition. Thus, in
order to sustain the catalytic performance exhibited by MoVTeNb mixed oxide, hot spots along the reactor bed should be
avoided or controlled, maintaining the catalytic bed temperature below 500 °C.This work was financially supported by the Instituto Mexicano del Petroleo.Valente, JS.; Armendariz-Herrera, H.; Quintana-Solorzano, R.; Del Angel, P.; Nava, N.; Masso Ramírez, A.; López Nieto, JM. (2014). Chemical, Structural, and Morphological Changes of a MoVTeNb Catalyst during Oxidative Dehydrogenation of Ethane. ACS Catalysis. 4:1292-1301. doi:10.1021/cs500143jS12921301
Protective Effects of a Rhodiola Crenulata Extract and Salidroside on Hippocampal Neurogenesis against Streptozotocin-Induced Neural Injury in the Rat
Previously we have demonstrated that a Rhodiola crenulata extract (RCE), containing a potent antioxidant salidroside, promotes neurogenesis in the hippocampus of depressive rats. The current study was designed to further investigate the protective effect of the RCE on neurogenesis in a rat model of Alzheimer's disease (AD) induced by an intracerebroventricular injection of streptozotocin (STZ), and to determine whether this neuroprotective effect is induced by the antioxidative activity of salidroside. Our results showed that pretreatment with the RCE significantly improved the impaired neurogenesis and simultaneously reduced the oxidative stress in the hippocampus of AD rats. In vitro studies revealed that (1) exposure of neural stem cells (NSCs) from the hippocampus to STZ strikingly increased intracellular reactive oxygen species (ROS) levels, induced cell death and perturbed cell proliferation and differentiation, (2) hydrogen peroxide induced similar cellular activities as STZ, (3) pre-incubation of STZ-treated NSCs with catalase, an antioxidant, suppressed all these cellular activities induced by STZ, and (4) likewise, pre-incubation of STZ-treated NSCs with salidroside, also an antioxidant, suppressed all these activities as catalase: reduction of ROS levels and NSC death with simultaneous increases in proliferation and differentiation. Our findings indicated that the RCE improved the impaired hippocampal neurogenesis in the rat model of AD through protecting NSCs by its main ingredient salidroside which scavenged intracellular ROS
The Embrace Magnetometer Network for South America: Network Description and Its Qualification
The present work is the first of a two-part paper on the Embrace Magnetometer Network. In this part, we present the new Embrace Magnetometer Network (Embrace MagNet) in South America, which is originally planned to cover most of the eastern portion of the Southern America longitudinal sector by installing and operating fluxgate magnetometer stations. We discuss the purpose and scientific goals of the network, associated with aeronomy and space weather. We provide details on the instrumentation, location of the sensors, sensitivity matching process, gain matching process, and magnetometer installation. In addition, we present and discuss details about the data storage, near-real time display, and availability.Facultad de Ciencias Astronómicas y Geofísica
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