871 resultados para Radioisotopes in the body


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Abstract The final disposal of residues generated at sewage treatment plants (STPs) has become a major problem for cities, due to the increase in the amount of treated sewage. One of the alternatives for the residue, labeled sewage sludge, is its reuse in agriculture and in degraded soil. However, not all pathogens and metals present in it are eliminated during treatment. Diplopods have been used as bioindicators in ecotoxicological tests as they are constantly in close contact with the soil. Owing to this fact, the purpose of this study was to expose specimens of the diplopod Rhinocricus padbergi to substrate containing sewage sludge collected at STPs to analyze morphological alterations in their parietal and perivisceral fat body, where substances are stored. The exposures were held for 7, 15, or 90 days at different concentrations of sewage sludge (control, 1%, 10%, and 50%). The parietal fat body showed no alterations in any of the three exposure periods or concentrations. Alterations in the perivisceral fat body were observed for all exposure periods. According to the results, we suggest that the sludge used has toxic agents responsible for changing the animal's perivisceral fat body. © 2012 Microscopy Society of America.

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Some crustaceans show variations of their reproductive biology within their geographical distribution, and knowledge about such variations is important for the comprehension of their reproductive adaptations. This study compared two populations of the fiddler crab Uca uruguayensis from two locations on the south-western Atlantic coast: Ubatuba Bay, São Paulo, Brazil and Samborombón Bay, Buenos Aires, Argentina. The population features analysed were the body size variation (carapace width = CW) and the size at the onset of sexual maturity (SOM) in order to test the hypothesis that the size at SOM, should be the same in relative terms (RSOM), independently of the latitudinal position. In the Brazilian population the CW ranged from 4.18 to 11.60 mm for males and 3.90 to 9.80 mm for females, and in the Argentinean population from 3.60 to 14.10 mm for males and 2.85 to 12.00 mm for females. In the Brazilian population the SOM was 7.1 (RSOM = 0.58) and 5.9 mm CW (RSOM = 0.57) for males and females, respectively, and in the Argentinean population it was 7.0 (RSOM = 0.42) and 6.75 mm CW (RSOM = 0.53) for males and females, respectively. This fact is probably related to a great plasticity in the life history features of Uca uruguayensis under different environmental conditions. © 2012 Marine Biological Association of the United Kingdom.

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Central α2-adrenoceptors and the pontine lateral parabrachial nucleus (LPBN) are involved in the control of sodium and water intake. Bilateral injections of moxonidine (α2-adrenergic/imidazoline receptor agonist) or noradrenaline into the LPBN strongly increases 0.3 M NaCl intake induced by a combined treatment of furosemide plus captopril. Injection of moxonidine into the LPBN also increases hypertonic NaCl and water intake and reduces oxytocin secretion, urinary sodium, and water excreted by cell-dehydrated rats, causing a positive sodium and water balance, which suggests that moxonidine injected into the LPBN deactivates mechanisms that restrain body fluid volume expansion. Pretreatment with specific α2-adrenoceptor antagonists injected into the LPBN abolishes the behavioral and renal effects of moxonidine or noradrenaline injected into the same area, suggesting that these effects depend on activation of LPBN α2-adrenoceptors. In fluid-depleted rats, the palatability of sodium is reduced by ingestion of hypertonic NaCl, limiting intake. However, in rats treated with moxonidine injected into the LPBN, the NaCl palatability remains high, even after ingestion of significant amounts of 0.3 M NaCl. The changes in behavioral and renal responses produced by activation of α2-adrenoceptors in the LPBN are probably a consequence of reduction of oxytocin secretion and blockade of inhibitory signals that affect sodium palatability. In this review, a model is proposed to show how activation of α2-adrenoceptors in the LPBN may affect palatability and, consequently, ingestion of sodium as well as renal sodium excretion.

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INTRODUCTION: Regenerative therapies using biomaterials require accurate information on interactions between the implanted material and the human body. To improve the process of bone regeneration it is necessary to obtain a better understanding of the influence of the surfaces on the early stages of osseointegration. This work aims to investigate the dynamic interaction between simulated body fluid (SBF) and titanium surfaces (Ti cp) immediately after their first contact. METHODS: Ti cp samples were passed through physicochemical treatments after immersion in acid solution, alkaline solution and solutions containing TiO2 and Ca2+, to obtain three different surfaces. These were characterized by electron microscopy and free energy estimates. The evaluation of the interaction with SBF was performed by measuring the dynamic contact angles after contacting the surfaces. RESULTS: The effects of SBF wettability were more significant on surfaces according to high energy estimates. A comparative analysis of the three types of surfaces showed that fluid spreading was greater in samples with greater polar components, indicating that the surface nature influences interactions in the early stages of osseointegration. CONCLUSION: The results indicate the influence of polar interactions in the dynamic wettability of the SBF. It is possible that these interactions can also influence cellular viability on surfaces. Based on these results, new experiments are being designed to improve the presented methodology as a tool for the evaluation of biomaterials without the need for in vivo experiments.

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Chromatoid body (CB) is a typical cytoplasmic organelle of germ cells, and it seems to be involved in RNA/protein accumulation for later germ-cell differentiation. Despite most of the events in mammals spermatogenesis had been widely described in the past decades and the increase in the studies related to the CB molecular composition and physiology, the origins and functions of this important structure of male germ cells are still unclear. The aims of this study were to describe the nucleolar cycle and also to find some relationship between the nucleolar organization and the CB assembling during the spermatogenesis in mammals. Cytochemical and cytogenetics analysis showed nucleolar fragmentation in post-pachytene spermatocytes and nucleolar reorganization in post-meiotic spermatids. Significant difference in the number and in the size of nucleoli between spermatogonia and round spermatids, as well as differences in the nucleolar position within the nucleus were also observed. Ultrastructural analysis showed the CB assembling in the cytoplasm of primary spermatocytes and the nucleolar fragmentation occurring at the same time. In conclusion our results suggest that the CB may play important roles during the spermatogenesis process in mammals and that its origin may be related to the nucleolar cycle during the meiotic cell cycle.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Nychthemeral and annual rhythms of the rectal temperature were determined for Corriedale sheep in a tropical climate. The minimum rectal temperature averaged 39.55 degrees C at 0500 hours in summer, and 38.87 degrees C at 0600 hours in winter. The maximum was 40.03 degrees C in summer (1700 hours) and 39.33 degrees C in winter (1830 hours). Annual cycle of the rectal temperature showed a minimum in July and maximum in December.

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Human activities generate a great amount of sewage daily, which is dumped into the sewer system. After sewage-treatment processes, sewage sludge is generated. Such byproduct can be treated by different methods; the result of treatment is a stabilized compost of reduced pathogenicity that has a similar inorganic chemical composition to the raw sewage sludge. After such pretreatment, sewage sludge is called a biosolids, and it can be used in agriculture. In this contest, the present study evaluated the effects of a sample of biosolids on the perivisceral fat body of a diplopod. These invertebrates are soil organisms that play an important role in the dynamics of terrestrial ecosystems, and as a consequence, they are in contact with xenobiotics present in this environmental compartment. Special emphasis is given on the interpretation of the effects of complex mixtures in target organs of diplopods. A semiquantitative analysis for the evaluation of histopathological changes in the perivisceral fat body was proposed. The sample-induced histopathological and ultrastructural changes in individuals exposed to it, and the severity of the effects was positively related to the exposure time, resulting in the deaths of exposed individuals after 90 days. Thus, the results indicate the need for caution in the use of biosolids as well as the need for improving waste management techniques, so they will produce environmentally innocuous final products.

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Central α2-adrenoceptors and the pontine lateral parabrachial nucleus (LPBN) are involved in the control of sodium and water intake. Bilateral injections of moxonidine (α2-adrenergic/imidazoline receptor agonist) or noradrenaline into the LPBN strongly increases 0.3 M NaCl intake induced by a combined treatment of furosemide plus captopril. Injection of moxonidine into the LPBN also increases hypertonic NaCl and water intake and reduces oxytocin secretion, urinary sodium, and water excreted by cell-dehydrated rats, causing a positive sodium and water balance, which suggests that moxonidine injected into the LPBN deactivates mechanisms that restrain body fluid volume expansion. Pretreatment with specific α2-adrenoceptor antagonists injected into the LPBN abolishes the behavioral and renal effects of moxonidine or noradrenaline injected into the same area, suggesting that these effects depend on activation of LPBN α2-adrenoceptors. In fluid-depleted rats, the palatability of sodium is reduced by ingestion of hypertonic NaCl, limiting intake. However, in rats treated with moxonidine injected into the LPBN, the NaCl palatability remains high, even after ingestion of significant amounts of 0.3 M NaCl. The changes in behavioral and renal responses produced by activation of α2-adrenoceptors in the LPBN are probably a consequence of reduction of oxytocin secretion and blockade of inhibitory signals that affect sodium palatability. In this review, a model is proposed to show how activation of α2-adrenoceptors in the LPBN may affect palatability and, consequently, ingestion of sodium as well as renal sodium excretion.

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Examination of scatological motifs in Théophile de Viau’s (1590-1626) libertine, or ‘cabaret’ poetry is important in terms of how the scatological contributes to the depiction of the Early Modern body in the French lyric.1 This essay does not examine Théophile’s portrait of the body strictly in terms of the ‘Baroque’ or the ‘neo-Classical.’ Rather, it argues that the scatological context in which he situates the body (either his, or those of others), reflects a keen sensibility of the body representative of the transition between these two eras. Théophile reinforces what Bernard Beugnot terms the body’s inherent ‘eloquence’ (17), or what Patrick Dandrey describes as an innate ‘textuality’ in what the body ‘writes’ (31), and how it discloses meaning. The poet’s scatological lyric, much of which was published in the Pamasse Satyrique of 1622, projects a different view of the body’s ‘eloquence’ by depicting a certain realism and honesty about the body as well as the pleasure and suffering it experiences. This Baroque realism, which derives from a sense of the grotesque and the salacious, finds itself in conflict with the Classical body which is frequently characterized as elegant, adorned, and ‘domesticated’ (Beugnot 25). Théophile’s private body is completely exposed, and, unlike the public body of the court, does not rely on masking and pretension to define itself. Mitchell Greenberg contends that the body in late sixteenth-century and early seventeenth-century French literature is often depicted in a chaotic manner because, ‘the French body politic was rent by tumultuous religious and social upheavals’ (62).2 While one could argue that Théophile’s portraits of a syphilis-ridden narrators are more a reflection of his personal agony rather than that of France as a whole, what emerges in Théophile is an emphasis on the movement, if not decomposition of the body.3 Given Théophile’s public persona and the satirical dimension of his work, it is difficult to imagine that the degeneration he portrays is limited only to his individual experience. On a collective level, Théophile reflects what Greenberg calls ‘a continued, if skewed apprehension of the world in both its physical and metaphysical dimensions’(62–3) typical of the era. To a large extent, the body Théophile depicts is a scatological body, one whose deterioration takes the form of waste, disease, and evacuation as represented in both the private and public domain. Of course, one could cast aside any serious reading of Théophile’s libertine verse, and virtually all of scatological literature for that matter, as an immature indulgence in the prurient. Nonetheless, it was for his dissolute behavior and his scatological poetry that Théophile was imprisoned and condemned to death. Consequently, this part of his work merits serious consideration in terms of the personal and poetic (if not occasionally political) statement it represents. With the exception of Claire Gaudiani’s outstanding critical edition of Théophile’s cabaret lyric, there exist no extensive studies of the poet’s libertine œuvre.4 Clearly however, these poems should be taken seriously with respect to their philosophical and aesthetic import. As a consequence, the objective becomes that of enhancing the reader’s understanding of the lyric contexts in which Théophile’s scatological offerings situate themselves. Structurally, the reader sees how the poet’s libertine ceuvre is just that — an integrated work in which the various components correspond to one another to set forth a number of approaches from which the texts are to be read. These points of view are not always consistent, and Théophile cannot be thought of as writing in a sequential manner along the lines of devotional Baroque poets such as Jean de La Ceppède and Jean de Sponde. However, there is a tendency not to read these poems in their vulgar totality, and to overlook the formal and substantive unity in this category of Théophile’s work. The poet’s resistance to poetic and cultural standards takes a profane, if not pornographic form because it seeks to disgust and arouse while denigrating the self, the lyric other, and the reader. Théophile’s pornography makes no distinction between the erotic and scatological. The poet conflates sex and shit because they present a double form of protest to artistic and social decency while titillating and attacking the reader’s sensibilities. Examination of the repugnant gives way to a cathartic experience which yields an understanding of, if not ironic delight in, one’s own filthy nature.

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Objective: To analyze the shear forces on the vertebral body L4 when submitted to a compression force by means of transmission photoelasticity. Methods: Twelve photoelastic models were divided into three groups, with four models per group, according to the positioning of the sagittal section vertebrae L4-L5 (sections A, B and C). The simulation was performed using a 15N compression force, and the fringe orders were evaluated in the vertebral body L4 by the Tardy compensation method. Results: Photoelastic analysis showed, in general, a homogeneous distribution in the vertebral bodies. The shear forces were higher in section C than B, and higher in B than A. Conclusion: The posterior area of L4, mainly in section C, showed higher shear concentrations, corresponding to a more susceptible area for bone fracture and spondylolisthesis. Economic and Decision Analyses Development of an Economic or Decision Model. Level I

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The neutron-rich lead isotopes, up to Pb-216, have been studied for the first time, exploiting the fragmentation of a primary uranium beam at the FRS-RISING setup at GSI. The observed isomeric states exhibit electromagnetic transition strengths which deviate from state-of-the-art shell-model calculations. It is shown that their complete description demands the introduction of effective three-body interactions and two-body transition operators in the conventional neutron valence space beyond Pb-208.