65 research outputs found
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
Use of Opuntia ficus-indica (L.) Mill extracts from Brazilian Caatinga as an alternative of natural moisturizer in cosmetic formulations
LADUMA: looking at the distant universe with the MeerKAT array
The cosmic evolution of galaxiesâ neutral atomic gas content is a major science driver for the Square Kilometre Array (SKA), as well as for its South African (MeerKAT) and Australian (ASKAP) precursors. Among the H I large survey programs (LSPs) planned for ASKAP and MeerKAT, the deepest and narrowest tier of the âwedding cakeâ will be defined by the combined L-band+UHF-band Looking At the Distant Universe with the MeerKAT Array (LADUMA) survey, which will probe H I in emission within a single âcosmic vuvuzelaâ that extends to z = 1.4, when the universe was only a third of its present age. Through a combination of individual and stacked detections (the latter relying on extensive multi-wavelength studies of the surveyâs target field), LADUMA will study the redshift evolution of the baryonic TullyâFisher relation and the cosmic H I density, the variation of the H I mass function with redshift and environment, and the connection between H I content and galaxiesâ stellar properties (mass, age, etc.). The survey will also build a sample of OH megamaser detections that can be used to trace the cosmic merger history. This proceedings contribution provides a brief introduction to the survey, its scientific aims, and its technical implementation, deferring a more complete discussion for a future article after the implications of a recent review of MeerKAT LSP project plans are fully worked out
Mechanisms of relaxant activity of the nitric oxide-independent soluble guanylyl cyclase stimulator BAY 41-2272 in rat tracheal smooth muscle
FAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOThe soluble guanylyl cyclase is expressed in airway smooth muscle, and agents that stimulate this enzyme activity cause airway smooth muscle relaxation and bronchodilation. The compound 5-Cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-pyrimidin-4-ylamine (BAY 41-2272) is a potent nitric oxide (NO)-independent soluble guanylyl cyclase stimulator, but little is known about its effects in airway smooth muscle. Therefore, this study aimed to investigate the mechanisms underlying the relaxations of rat tracheal smooth muscle induced by BAY 41-2272. Tracheal rings were mounted in 10-ml organ baths for isometric force recording. BAY 41-2272 concentration-dependently relaxed carbachol-precontracted tracheal rings (pEC(50) = 6.68 +/- 0.14). Prior incubation with the NO synthesis inhibitor L-NAME (100 mu M) or the soluble guanylyl cyclase inhibitor ODQ (10 mu M) caused significant rightward shifts in the concentration-response curves to BAY 41-2272. Sodium nitroprusside caused concentration-dependent relaxations, which were greatly potentiated by BAY 41-2272 and completely inhibited by ODQ. In addition, BAY 41-2272 shifted to the right the tracheal contractile responses to either carbachol (0.01-1 mu M) or electrical field stimulation (EFS, 1-32 Hz). BAY 41-2272 (1 mu M) also caused a marked rightward shift and decreased the maximal contractile responses to extracellular CaCl2, and such effect was not modified by pretreatment with ODQ. In addition, BAY 41-2272 (up to 1 mu M) significantly increased the cGMP levels, and that was abolished by ODQ. Our results indicate that BAY 41-2272 causes cGMP-dependent rat tracheal smooth muscle relaxations in a synergistic fashion with exogenous NO. BAY 41-2272 has also an additional mechanism independently of soluble guanylyl cyclase activation possibly involving Ca(2+) entry blockade6451-3158164FAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOFAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOsem informaçã
The role of superoxide anion in the inhibitory effect of SIN-1 in thrombin-activated human platelet adhesion
CAPES â COORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL E NĂVEL SUPERIORReactive oxygen species have an important role in the control of platelet activity. Superoxide anion (O(2)(-)) is a free radical that can be converted into other reactive oxygen species such as peroxynitrite (ONOO(-)) that is formed from the reaction between O(2)(-) and nitric oxide (NO). There are conflicting data on ONOO(-) effects in platelets because it presents pro- or anti-aggregatory actions. 3-morpholinosydnonimine (SIN-1) co-generates NO and O(2)(-), yielding ONOO(-). Therefore, the present study aimed to investigate the mechanisms involved in the inhibition of human platelet adhesion by SIN-1. Microtiter plates were coated with human fibrinogen, after which washed platelets (6 x 10(8) platelets/ml) were added to adhere. Exposure of non-activated and thrombin-activated platelets to SIN-1 (0.001-100 mu M) concentration-dependently inhibited adhesion, which was accompanied by marked increases in the cyclic GMP levels. In non-activated platelets, the soluble guanylate cyclase inhibitor ODQ prevented the SIN-1 -induced cGMP elevations and adhesion inhibition. In thrombin-activated platelets, ODQ fully prevented the SIN-1-induced cGMP elevations, but only partly prevented the adhesion inhibition. The O(2)(-) and ONOO(-) scavengers superoxide dismutase (SOD) and -(-)epigallocatechin gallate, respectively, had minimal effects in non-activated platelets. The inhibition of activated platelets by SIN-1 1 was reversed by SOD and partly reduced by ECG. Western blot analysis of SIN-1-treated platelets showed a single 105 kDa-nitrated band. Nanospray LC-MS-MS identified the protein containing 3-nitrotyrosine residues as human alpha-actinin-1-cytoskeletal isoform. Our data show that platelet adhesion inhibition by SIN-1 in activated platelets involves cGMP-independent mechanism through O(2)(-) generation. Superoxide anion signaling pathway includes ONOO(-) formation and alpha-actinin nitration6271-3229234CAPES â COORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL E NĂVEL SUPERIORCAPES â COORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL E NĂVEL SUPERIORsem informaçã
Characterization of a new platelet aggregating factor from crotoxin Crotalus durissus cascavella venom
FAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOCNPQ â CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICOIn this article we investigated the platelet aggregating activity of whole crotoxin and its subunits isolated from Crotalus durissus cascavella venom. During the purification protocols of the venom, using HPLC molecular exclusion, we detected the presence of two different serine protease activities in the gyroxin fraction, and another in the crotoxin fraction, which induced strong and irreversible platelet aggregation, in addition to blood coagulation. From crotoxin, we isolated PLA(2), crotapotin (both fractions corresponding approximately 85% of whole crotoxin) and another minor fraction (F20) that exhibited serine protease activity. After a new fractionation on reverse phase HPLC chromatography, we obtained three other fractions named as F201, F202 and F203. F202 was obtained with high degree of molecular homogeneity with molecular mass of approximately 28 kDa and a high content of acidic amino residues, such as aspartic acid and glutamic acid. Other important amino acids were histidine, cysteine and lysine. This protein exhibited a high specificity for BApNA, a Michaelis-Menten behavior with Vmax estimated in 5.64 mu M/min and a Km value of 0.58 mM for this substrate. In this work, we investigated the ability of F202 to degrade fibrinogen and observed alpha and beta chain cleavage. Enzymatic as well as the platelet aggregation activities were strongly inhibited when incubated with TLCK and PMSF, specific inhibitors of serine protease. Also, F202 induced platelet aggregation in washed and platelet-rich plasma, and in both cases, TLCK inhibited its activity. The N-terminal amino acid sequence of F202 presented a high amino acid sequence homology with other thrombin-like proteins, but it was significantly different from gyroxin. These results showed that crotoxin is a highly heterogeneous protein composed of PLA(2), thrombin-like and other fractions that might explain the diversity of physiological and pharmacological activities of this proteinSpringer253183192FAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOCNPQ â CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICOFAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOCNPQ â CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO2004/00040-3300211.2004New York, N
Measuring Lower Extremity Strength in Older Adults: The Stability of Isokinetic versus 1RM Measures
Characterization of a New Platelet Aggregating Factor from Crotoxin Crotalus durissus cascavella Venom
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