22 resultados para 560 Fossils
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
Objective. Estimate cataract surgical rates (CSR) for Brazil and each federal unit in 2006 and 2007 based on the number of surgeries performed by the Unified Health System to help plan a comprehensive ophthalmology network in order to eliminate cataract blindness in compliance with the target set by the World Health Organization (WHO) of 3 000 cataract surgeries per million inhabitants per year. Methods. This descriptive study calculates CSR by using the number of cataract surgeries carried out by the Brazilian Unified Health System for each federal unit and estimates the need for cataract surgery in Brazil for 2006-2007, with official population data provided by the Brazilian Institute of Geography and Statistics. The number of cataract surgeries was compared with the WHO target. Results. To reach the WHO goal for eliminating age-related cataract blindness in Brazil, 560 312 cataract surgeries in 2006 and 568 006 surgeries in 2007 needed to be done. In 2006, 179 121 cataract surgeries were done by the Unified Health System, corresponding to a CSR of 959 per million population; in 2007, 223 317 were performed, with a CSR of 1 179. With the Brazilian Council of Ophthalmology estimation of 165 000 surgeries each year by the non-public services, the CSR for Brazil would be 1 842 for 2006 and 2 051 for 2007. The proportions needed to achieve the proposed target were 38.6% in 2006 and 31.6% in 2007. Conclusions. Human resources, technical expertise, and equipment are crucial to reach the WHO goal. Brazil has enough ophthalmologists but needs improved planning and infrastructure in order to eliminate the problem, aspects that require greater financial investment and stronger political commitment.
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The study aimed at verifying the associated factors of self-perceived body changes in adults living with HIV in highly-active antiretroviral therapy (HAART) in the city of Sao Paulo, Brazil. This cross-sectional study was conducted among people living with HIV on HAART for at least three months. A standardized questionnaire was used for assessing self-perceived body changes. Associated factors relating to self-reported body changes in people living with HIV (PLHIV) were assessed with Student`s t-test and chi-square test. In total, 507 patients were evaluated. The mean time since diagnosis was 6.6 years [standard deviation (SD)+/-4.1], and the mean duration of HAART was 5.1 years (SD+/-3.3). Self-perceived body changes were reported by 79.5% of the participants and were associated with viral load and duration of HAART. Fibre intake was lower among males who gained in abdominal fat (p=0.035). HAART-related body changes were reported by the large majority of the population and were associated with demographic and clinical variables.
Resumo:
Endogenous contents of indolyl-3-acetic acid (IAA) and abscisic acid (ABA) were quantified in excised roots of Catasetum fimbriatum (Orchidaceae) cultured in vitro on solidified Vacin and Went medium with 1, 2, 4, 6, 8 and 10 % sucrose, as well as 2 % sucrose plus mannitol. Maximum root growth was observed in media with 4 % sucrose and 2 % sucrose plus 2.2 % mannitol, suggesting that a moderate water or osmotic stress promotes orchid root growth. Contents of both ABA and IAA increased in parallel to increasing sucrose concentration and a correlation between root elongation and the ABA/IAA ratio was observed. Incubating isolated C. fimbriatum roots with radiolabeled tryptophan, we showed an accumulation of IAA and its conjugates.
Resumo:
Limb-girdle muscular dystrophies are a heterogeneous group of disorders characterized by progressive degeneration of skeletal muscle caused by the absence or deficiency of muscle proteins. The murine model of Limb-Girdle Muscular Dystrophy 2B, the SJL mice, carries a deletion in the dysferlin gene. Functionally, this mouse model shows discrete muscle weakness, starting at the age of 4-6 weeks. The possibility to restore the expression of the defective protein and improve muscular performance by cell therapy is a promising approach for the future treatment of progressive muscular dystrophies (PMD). We and others have recently shown that human adipose multipotent mesenchymal stromal cells (hASCs) can differentiate into skeletal muscle when in contact with dystrophic muscle cells in vitro and in vivo. Umbilical cord tissue and adipose tissue are known rich sources of multipotent mesenchymal stromal cells (MSCs), widely used for cell-based therapy studies. The main objective of the present study is to evaluate if MSCs from these two different sources have the same potential to reach and differentiate in muscle cells in vivo or if this capability is influenced by the niche from where they were obtained. In order to address this question we injected human derived umbilical cord tissue MSCs (hUCT MSCs) into the caudal vein of SJL mice with the same protocol previously used for hASCs; we evaluated the ability of these cells to engraft into recipient dystrophic muscle after systemic delivery, to express human muscle proteins in the dystrophic host and their effect in functional performance. These results are of great interest for future therapeutic application.
Thyroid hormone stimulates NO production via activation of the PI3K/Akt pathway in vascular myocytes
Resumo:
Aims Thyroid hormone (TH) rapidly relaxes vascular smooth muscle cells (VSMCs). However, the mechanisms involved in this effect remain unclear. We hypothesize that TH-induced rapid vascular relaxation is mediated by VSMC-derived nitric oxide (NO) production and is associated with the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signalling pathway. Methods and results NO levels were determined using a NO-specific fluorescent dye (DAF-2) and nitrite (NO(2)) levels. Expression of NO synthase (NOS) isoforms and proteins of the PI3K/Akt pathway was determined by both western blotting and immunocytochemistry. Myosin light chain (MLC) phosphorylation levels were also investigated by western blotting. Exposure of cultured VSMCs from rat thoracic aortas to triiodothyronine (T3) resulted in a significant decrease of MLC phosphorylation levels. T3 also induced a rapid increase in Akt phosphorylation and increased NO production in a dose-dependent manner (0.001-1 mu M). VSMCs stimulated with T3 for 30 min showed an increase in the expression of all three NOS isoforms and augmented NO production, effects that were prevented by inhibitors of PI3K. Vascular reactivity studies showed that vessels treated with T3 displayed a decreased response to phenylephrine, which was reversed by NOS inhibition. These data suggest that T3 treatment induces greater generation of NO both in aorta and VSMCs and that this phenomenon is endothelium independent. In addition, these findings show for the first time that the PI3K/Akt signalling pathway is involved in T3-induced NO production by VSMCs, which occurs with expressive participation of inducible and neuronal NOS. Conclusion Our data strongly indicate that T3 causes NO-dependent rapid relaxation of VSMC and that this effect is mediated by the PI3K/Akt signalling pathway.
Resumo:
Background and purpose: The present study was designed to assess whether cyclooxygenase-2 (COX-2) activation is involved in the effects of chronic aldosterone treatment on endothelial function of mesenteric resistance arteries (MRA) from Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Experimental approach: Relaxation to acetylcholine was measured in MRA from both untreated and aldosterone-treated strains. Vasomotor responses to prostacyclin and U46619 were also analysed. Release of 6-oxo-prostaglandin (PG)F(1 alpha) and thromboxane B(2) (TxB(2)) was determined by enzyme immunoassay. COX-2 protein expression was measured by western blot. Key results: Aldosterone reduced acetylcholine relaxation in MRA from both strains. In MRA from both aldosterone-treated strains the COX-1/2 or COX-2 inhibitor (indomethacin and NS-398, respectively), Tx2 synthesis inhibitor (furegrelate), prostacyclin synthesis inhibitor (tranylcypromine) or Tx2/PG2 receptor antagonist (SQ 29 548), but not COX-1 inhibitor SC-560, increased acetylcholine relaxation. In untreated rats this response was increased only in SHR. Prostacyclin elicited a biphasic vasomotor response: lower concentrations elicited relaxation, whereas higher concentrations elicited contraction that was reduced by SQ 29 548. Aldosterone increased the acetylcholine-stimulated production of 6-oxo-PGF(1 alpha) and TxB(2) in MRA from both strains. COX-2 expression was higher in both strains of rats treated with aldosterone. Conclusions and implications: Chronic treatment with aldosterone impaired endothelial function in MRA under normotensive and hypertensive conditions by increasing COX-2-derived prostacyclin and thromboxane A(2). As endothelial dysfunction participates in the pathogenesis of many cardiovascular disorders we hypothesize that anti-inflammatory drugs, specifically COX-2 inhibitors, could ameliorate vascular damage in patients with elevated aldosterone production.
Resumo:
Potassium content in tea brew was determined by gamma-ray spectroscopy, Using the 1461 keV gamma-ray fro M (40)K, the naturally occurring radioactive isotope of potassium. We measured radiation with a shielded HPGe detector from individual test samples of tea leaves, before and after infusion preparation, and from commercial instant tea powder. The correction factor for the gamma-ray self-absorption in the extended source was determined with the help of Monte-Carlo simulations. This gamma-ray spectroscopy technique enabled the absolute determination of potassium content with a relative uncertainty smaller than 4%, at the one standard deviation confidence level, showing the feasibility of this method. An experiment to evaluate a possible systematic Uncertainty due to K distribution heterogeneity in the sample was performed, with file result that the corresponding relative standard deviation is smaller than 2% at 95% confidence level. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
This work reports on the excited-state absorption spectrum of oxidized Cytochrome c (Fe(3+)) dissolved in water, measured with the Z-scan technique with femtosecond laser pulses. The excited-state absorption cross-sections between 460 and 560 nm were determined with the aid of a three-energy-level model. Reverse saturable absorption was observed below 520 nm, while a saturable absorption process occurs in the Q-band, located around 530 nm. Above 560 nm, a competition between saturable absorption and two-photon absorption was inferred. These results show that Cytochrome c presents distinct nonlinear behaviors, which may be useful to study electron transfer chemistry in proteins by one- and two-photon absorption. In addition, owing to these nonlinear optical features, this molecule may be employed in applications involving photodynamics therapy and saturable absorbers. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
In this paper, we report the measurement of Rb(2) molecule formation rate constant due to a two body process in a magneto-optical trap as a function of the sample temperature. The ground state molecules are detected by two-photon ionization, through the intermediate a(3)Sigma(+)(u) -> 2(3)Pi(g) molecular band. Our results show that the Rb(2) molecules formed in the MOT could be due to a wave shape resonance, which enhances the molecule formation rate. This effect may be used to enhance the molecule production; and therefore it maybe important to future experiments involving production and trapping of cold ground state molecules.
Resumo:
The Mantiqueira Province represents a series of supracrustal segments of the South-American counterpart formed during the Gondwana Supercontinent agglutination. In this crustal domain, the process of escape tectonics played a conspicuous role, generating important NE-N-S-trending lineaments. The oblique component of the motions of the colliding tectonic blocks defined the transpressional character of the main suture zones: Lancinha-Itariri, Cubato-Arcadia-Areal, Serrinha-Rio Palmital in the Ribeira Belt and Sierra Ballena-Major Gercino in the Dom Feliciano Belt. The process as a whole lasted for ca. 60 Ma, since the initial collision phase until the lateral escape phase predominantly marked by dextral and subordinate sinistral transpressional shear zones. In the Dom Feliciano Belt, southern Brazil and Uruguay, transpressional event at 630-600 Ma is recognized and in the Ribeira Belt, despite less coevally, the transpressional event occurred between 590 and 560 Ma in its northern-central portion and between ca. 625 and 595 Ma in its central-southern portion. The kinematics of several shear zones with simultaneous movement in opposite directions at their terminations is explained by the sinuosity of these lineaments in relation to a predominantly continuous westward compression.
Resumo:
The Itajai Basin located in the southern border of the Luis Alves Microplate is considered as a peripheral foreland basin related to the Dom Feliciano Belt. It presents an excellent record of the Ediacaran period, and its upper parts display the best Brazilian example of Precambrian turbiditic deposits. The basal succession of Itajai Group is represented by sandstones and conglomerates (BaA(0) Formation) deposited in alluvial and deltaic-fan systems. The marine upper sequences correspond to the Ribeiro Carvalho (channelized and non-channelized proximal silty-argillaceous rhythmic turbidites), Ribeiro Neisse (arkosic sandstones and siltites), and Ribeiro do Bode (distal silty turbidites) formations. The ApiA(0)na Formation felsic volcanic rocks crosscut the sedimentary succession. The Cambrian Subida leucosyenogranite represents the last felsic magmatic activity to affect the Itajai Basin. The Brusque Group and the Florianpolis Batholith are proposed as source areas for the sediments of the upper sequence. For the lower continental units the source areas are the Santa Catarina, So Miguel and CamboriA(0) complexes. The lack of any oceanic crust in the Itajai Basin suggests that the marine units were deposited in a restricted, internal sea. The sedimentation started around 600 Ma and ended before 560 Ma as indicated by the emplacement of rhyolitic domes. The Itajai Basin is temporally and tectonically correlated with the Camaqu Basin in Rio Grande do Sul and the Arroyo del Soldado/Piriapolis Basin in Uruguay. It also has several tectono-sedimentary characteristics in common with the African-equivalent Nama Basin.
Resumo:
The South-American continent is constituted of three major geologic-geotectonic entities the homonym platform (consolidated at the end of the Cambrian) the Andean chain (essentially Meso-Cenozoic) and the Patagonian terrains affected by tectonism and magmatism through almost all of the Phanerozoic The platform is constituted by a series of cratonic nuclei (pre-Tonian fragments of the Rodinia fission) surrounded by a complex fabric of Neoproterozoic structural provinces Two major groups of orogenic processes (plate interaction cycles) constitute the evolution of these provinces the older occurred in the Tonian (smaller in area) and the younger Brasiliano that is present in all provinces The Tonian cycles (pre-Rodinia fission?) are still being sorted out and many questions still need to be answered The Brasiliano orogenic collage events (post-Rodinia fission?) developed in three main stages in part coeval from a province to another and are 650-600 580-560 and 540-500 Ma respectively (the late event reaching the Ordovician) The first group of orogenies is recorded in practically all provinces The third group is restricted to part of the Mantiqueira Province (southeast of the platform Buzios Orogeny) and present in the Pampean province (SW of the platform) For all these groups of orogenic events there are considerable records of rock assemblages related to processes of convergent plate interaction opening accretion collision and further extrusion There is a good correlation between the geologic and geotectonic data and geochemical and isotopic data The late tectonic processes (post-orogenic magmatism foreland basins etc) of the first two groups compete in time in distinct spaces with the peak of orogenic processes in the third group The introduction of the SHRIMP U-Pb methodology was fundamental to separate the Tonian and post-Tonian orogenic groups and their respective divisions in time and space Thus there are still many open points/problems which lead to expectations of addressing these issues in the near future with the more Intense use of this methodology (C) 2010 Elsevier B V All rights reserved
Resumo:
The Corumba Group cropping out in the southern Paraguay Belt in Brazil is one of the most complete Ediacaran sedimentary archives of palaeogeographic climatic biogeochemical and biotic evolution in southwestern Gondwana The unit hosts a rich fossil record including acritarchs vendotaenids (Vendo taenia Eoholynia) soft-bodied metazoans (Corumbella) and skeletal fossils (Cloudina Titanotheca) The Tamengo Formation made up mainly of limestones and marls provides a rich bio- and chemostratigraphic record Several outcrops formerly assigned to the Cuiaba Group are here included in the Tamengo Formation on the basis of lithological and chemostratigraphical criteria High-resolution carbon isotopic analyses are reported for the Tamengo Formation showing (from base to top) (1) a positive delta(13)C excursion to +4 parts per thousand PDB above post-glacial negative values (2) a negative excursion to -3 5 parts per thousand associated with a marked regression and subsequent transgression (3) a positive excursion to +5 5 parts per thousand and (4) a plateau characterized by delta(13)C around +3 parts per thousand A U-Pb SHRIMP zircon age of an ash bed Interbedded in the upper part of the delta(13)C positive plateau yielded 543 +/- 3 Ma which is considered as the depositional age (Babinski et al 2008a) The positive plateau in the upper Tamengo Formation and the preceding positive excursion are ubiquitous features in several successions worldwide including the Nama Group (Namibia) the Dengying Formation (South China) and the Nafun and Ara groups (Oman) This plateau is constrained between 542 and 551 Ma thus consistent with the age of the upper Tamengo Formation The negative excursion of the lower Tamengo Formation may be correlated to the Shuram-Wonoka negative anomaly although delta(13)C values do not fall beyond -3 5 parts per thousand in the Brazilian sections Sedimentary breccias occur just beneath this negative excursion in the lower Tamengo Formation One possible interpretation of the origin of these breccias is a glacioeustatic sea-level fall but a tectonic interpretation cannot be completely ruled out Published by Elsevier B V
Resumo:
The Major Gercino Shear Zone is one of the NE-SW lineaments that separate the Neoproterozoic Dom Feliciano Belt, of Brazil and Uruguay, into two different domains: a northwestern supracrustal domain from a southeastern granitoid domain. The shear zone, striking NE, is composed of protomylonites to ultramylonites with mainly dextral kinematic indicators. In Santa Catarina State, southern Brazil, the shear zone is composed of two mylonite belts. The mylonites have mineral orientations produced under greenschist fades conditions at a high strain rate. Strong flattening and coaxial deformation indicate the transpressive character, while the role of pure shear is emphasized by the orientation of the mylonite belts in relation to the inferred stress field component. The quartz microstructures point out that different dynamic recrystallization regimes and crystal plasticity were the dominant mechanisms of deformation during the mylonitization process. Additionally, the fabrics suggest that the glide systems are activated for deformation conditions compatible with the metamorphism in the middle greenschist facies. Elongated granitoid intrusions belonging to two petrographically, geochemically and isotopically distinct rock associations occur between the two mylonite belts. The structures observed in the granites result from a deformation range from magmatic to solid-state conditions points to a continuum of magma straining during and just after its crystallization. Conventional U-Pb analysis of multi-crystal zircon fractions yielded essentially identical ages of 609 +/- 16 Ma and 614 +/- 2 Ma for the two granitic associations, and constrain the transpressive phase of the shear zone. K-Ar ages of biotites between 585 and 560 Ma record the slow cooling and uplift of the intrusions. Some K-Ar ages of micas in regional mylonites are similar, suggesting that thermo-tectonic activity was intense up to this time, probably related to the agglutination of the granite belt to the supracrustal belt NW of the MGSZ. (C) 2009 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
Resumo:
Three species of chondrichthyans are reported from conglomeratic sandstone at the base of the Lower Permian (Artinskian) Irati Formation (Parana Basin) near Rio Claro, Sao Paulo State, Brazil. The fossils include: 1) dispersed teeth of the petalodont ltapyrodus punctatus Silva Santos 1990, first described from the Permian (Artinskian) Pedra do Fogo Formation, Parnaiba Basin, Northeast Brazil; 2) a new species of tooth of the Order Orodontiformes; and 3) a new species of finspine of the Order Ctenacanthiformes. These fossils occur in an allochthonous assemblage of vertebrate remains including other Chondrichthyes, Xenacanthiformes and cladodonts, paleonisciform bony fish, and tetrapods. This discovery is a significant contribution to the sparse record of South American Chondrichthyes from the Early Permian and raises questions regarding the paleoenvironmental adaptations among these fish within Paleozoic basins of Brazil at this time. (C) 2010 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.