Showing papers by "Universidade Federal de Santa Catarina published in 2011"

O método da revisão integrativa nos estudos organizacionais

Abstract: As diferentes formas de revisao da literatura baseiam-se desde a revisao bibliografica tradicional (revisao narrativa), ate o uso de mecanismos e metodologias, utilizados nos campos da saude e educacao por pesquisadores para descrever o estado da arte de um tema, chamado de revisao bibliografica sistematica. O objetivo deste artigo e discutir o processo de revisao da literatura nos estudos organizacionais, trazendo para esse escopo metodologias de revisao da literatura de outras areas do saber, como por exemplo, a revisao bibliografica sistematica. Como metodologia adotada o estudo discute o metodo da revisao integrativa, pertecente a revisao bibliografica sistematica. Os resultados da pesquisa mostram que a revisao integrativa, permite ao pesquisador aproximar-se da problematica que deseja apreciar, tracando um panorama sobre a sua producao cientifica, de forma que o pesquisador possa conhecer a evolucao do tema ao longo do tempo e, com isso, visualizar possiveis oportunidades de pesquisa nos estudos organizacionais.

A comprehensive classification of galaxies in the Sloan Digital Sky Survey: how to tell true from fake AGN?

Abstract: We use the W Hα versus [NII]/Hα (WHAN) diagram introduced by us in previous work to provide a comprehensive emission-line classification of Sloan Digital Sky Survey galaxies. This classification is able to cope with the large population of weak line galaxies that do not appear in traditional diagrams due to a lack of some of the diagnostic lines. A further advantage of the WHAN diagram is to allow the differentiation between two very distinct classes that overlap in the low-ionization nuclear emission-line region (LINER) region of traditional diagnostic diagrams. These are galaxies hosting a weakly active galactic nucleus (wAGN) and 'retired galaxies' (RGs), i.e. galaxies that have stopped forming stars and are ionized by their hot low-mass evolved stars. A useful criterion to distinguish true from fake AGN (i.e. the RGs) is the value of ξ, which measures the ratio of the extinction-corrected Hα luminosity with respect to the Hα luminosity expected from photoionization by stellar populations older than 10 8 yr. We find that ξ follows a markedly bimodal distribution, with a ξ≫1 population composed by systems undergoing star formation and/or nuclear activity, and a peak at ξ~1 corresponding to the prediction of the RG model. We base our classification scheme not on ξ but on a more readily available and model-independent quantity which provides an excellent observational proxy for ξ: the equivalent width of Hα. Based on the bimodal distribution of W Hα , we set the practical division between wAGN and RGs at W Hα = 3 A. Five classes of galaxies are identified within the WHAN diagram: (i) pure star-forming galaxies: log[N II]/Hα 3 A; (ii) strong AGN (i.e. Seyferts): log[NII]/Hα > -0.4 and W Hα > 6A; (iii) weak AGN: log[N n]/Hα > -0.4 and W Hα between 3 and 6 A; (iv) RGs (i.e. fake AGN): W Hα < 3 A; (v) passive galaxies (actually, lineless galaxies): W Hα and W [NII] < 0.5 A. A comparative analysis of star formation histories and of other physical and observational properties in these different classes of galaxies corroborates our proposed differentiation between RGs and wAGN in the LINER-like family. This analysis also shows similarities between strong and weak AGN on the one hand, and retired and passive galaxies on the other.

Omega-3 Fatty Acid-Derived Mediators 17(R)-Hydroxy Docosahexaenoic Acid, Aspirin-Triggered Resolvin D1 and Resolvin D2 Prevent Experimental Colitis in Mice

Abstract: Resolvins of the D series are generated from docosahexaenoic acid, which are enriched in fish oils and are believed to exert beneficial roles on diverse inflammatory disorders, including inflammatory bowel disease (IBD). In this study, we investigated the anti-inflammatory effects of the aspirin-triggered resolvin D1 (AT-RvD1), its precursor (17(R)-hydroxy docosahexaenoic acid [17R-HDHA]) and resolvin D2 (RvD2) in dextran sulfate sodium (DSS)- or 2,4,6-trinitrobenzene sulfonic acid-induced colitis. Our results showed that the systemic treatment with AT-RvD1, RvD2, or 17R-HDHA in a nanogram range greatly improved disease activity index, body weight loss, colonic damage, and polymorphonuclear infiltration in both colitis experimental models. Moreover, these treatments reduced colonic cytokine levels for TNF-α, IL-1β, MIP-2, and CXCL1/KC, as well as mRNA expression of NF-κB and the adhesion molecules VCAM-1, ICAM-1, and LFA-1. Furthermore, AT-RvD1, but not RvD2 or 17R-HDHA, depended on lipoxin A4 receptor (ALX) activation to inhibit IL-6, MCP-1, IFN-γ, and TNF-α levels in bone marrow-derived macrophages stimulated with LPS. Similarly, ALX blockade reversed the beneficial effects of AT-RvD1 in DSS-induced colitis. To our knowledge, our findings showed for the first time the anti-inflammatory effects of resolvins of the D series and precursor 17R-HDHA in preventing experimental colitis. We also demonstrated the relevant role exerted by ALX activation on proresolving action of AT-RvD1. Moreover, AT-RvD1 showed a higher potency than 17R-HDHA and RvD2 in preventing DSS-induced colitis. The results suggest that these lipid mediators possess a greater efficacy when compared with other currently used IBD therapies, such as monoclonal anti-TNF, and have the potential to be used for treating IBD.

β-Caryophyllene inhibits dextran sulfate sodium-induced colitis in mice through CB2 receptor activation and PPARγ pathway.

Abstract: Cannabinoid receptor 2 (CB2) activation is suggested to trigger the peroxisome proliferator-activated receptor-γ (PPARγ) pathway, and agonists of both receptors improve colitis. Recently, the plant metabolite ( E )-β-caryophyllene (BCP) was shown to bind to and activate CB2. In this study, we examined the anti-inflammatory effect of BCP in dextran sulfate sodium (DSS)-induced colitis and analyzed whether this effect was mediated by CB2 and PPARγ. Oral treatment with BCP reduced disease activity, colonic macro- and microscopic damage, myeloperoxidase and N -acetylglucosaminidase activities, and levels and mRNA expression of colonic tumor necrosis factor-α, IL-1β, interferon-γ, and keratinocyte-derived chemokine. BCP treatment also inhibited the activation of extracellular signal-regulated kinase 1/2, nuclear factor κB, IκB-kinase α/β, cAMP response element binding and the expression of caspase-3 and Ki-67. Moreover, BCP enhanced IL-4 levels and forkhead box P3 mRNA expression in the mouse colon and reduced cytokine levels (tumor necrosis factor-α, keratinocyte-derived chemokine, and macrophage-inflammatory protein-2) in a culture of macrophages stimulated with lipopolysaccharide. The use of the CB2 antagonist AM630 or the PPARγ antagonist GW9662 significantly reversed the protective effect of BCP. Confirming our results, AM630 reversed the beneficial effect of BCP on pro-inflammatory cytokine expression in IEC-6 cells. These results demonstrate that the anti-inflammatory effect of BCP involves CB2 and the PPARγ pathway and suggest BCP as a possible therapy for the treatment of inflammatory bowel disease.

Novel-design ultra-thin CAD/CAM composite resin and ceramic occlusal veneers for the treatment of severe dental erosion

Abstract: Statement of problem Ultra-thin bonded posterior occlusal veneers represent a conservative alternative to traditional inlays and complete coverage crowns for the treatment of severe erosive lesions. There is a lack of data regarding selection of the most appropriate material and its influence on fatigue resistance, which may affect restoration longevity. Purpose The purpose of this study was to assess the influence of CAD/CAM restorative material (ceramic vs. composite resin) on fatigue resistance of ultra-thin occlusal veneers. Material and methods A standardized nonretentive tooth preparation (simulating advanced occlusal erosion) was applied to 40 extracted molars including removal of occlusal enamel, and immediate dentin sealing (Optibond FL). All teeth were restored with a 0.6 mm-thick occlusal veneer (Cerec3 chairside CAD/CAM system). Reinforced ceramics (Empress CAD and e.max CAD) and composite resins (Paradigm MZ100 and XR (experimental blocks)) were used to mill the restorations (n=10). The intaglio surfaces were HF-etched and silanated (reinforced ceramics) or airborne-particle abraded and silanated (composite resins). Preparations were airborne-particle abraded and etched before restoration insertion. All restorations were adhesively luted with preheated Filtek Z100. Cyclic isometric loading was applied at 5 Hz, beginning with a load of 200N (x5,000), followed by stages of 400, 600, 800, 1000, 1200 and 1,400N at a maximum of 30,000 cycles each. The number of cycles at initial failure (first cracks) was recorded. Specimens were loaded until catastrophic failure (lost restoration fragment) or to a maximum of 185,000 cycles. Groups were compared using the life table survival analysis (α=.008, Bonferroni-method). Results Empress CAD and e.max CAD initially failed at an average load of 500N and 800N, respectively with no specimen withstanding all 185,000 load cycles (survival 0%); with MZ100 and XR the survival rate was 60% and 100%, respectively. Conclusions Both composite resins (MZ100 and XR) increased the fatigue resistance of ultra-thin occlusal veneers (P

Genome of Herbaspirillum seropedicae Strain SmR1, a Specialized Diazotrophic Endophyte of Tropical Grasses

Abstract: The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The ParanaState Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/ hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.

The precursor of resolvin D series and aspirin‐triggered resolvin D1 display anti‐hyperalgesic properties in adjuvant‐induced arthritis in rats

Abstract: BACKGROUND AND PURPOSE Resolution of inflammation is mediated by endogenous molecules with anti-inflammatory and pro-resolving activities and they have generated new possibilities for the treatment of inflammatory diseases. Here, we have investigated the possible anti-hyperalgesic effects of two lipids, aspirin-triggered resolvin D1 (AT-RvD1) and its precursor, 17(R)-hydroxy-4Z,7Z,10Z,13Z,15E,17R,19Z-docosahexaenoic acid (17(R)HDoHE). EXPERIMENTAL APPROACH The anti-hyperalgesic effects of both lipid mediators were evaluated, using mechanical and thermal stimuli, at different time-points in adjuvant-induced arthritis in rats. Cytokine levels were measured, and immunohistochemistry and real-time PCR for pro-inflammatory mediators were also performed. KEY RESULTS The precursor of resolvin D series, 17(R)HDoHE, given systemically, inhibited the development and the maintenance of mechanical hyperalgesia in acute inflammation. Such effects were likely to be associated with modulation of both NF-κB and COX-2 in dorsal root ganglia and spinal cord. 17(R)HDoHE was also effective against sub-chronic pain. Unexpectedly, repeated treatment with 17(R)HDoHE did not modify paw and joint oedema in the sub-chronic model, while joint stiffness was prevented. Notably, AT-RvD1 exhibited marked anti-hyperalgesic effects in acute inflammation when given systemically. The efficacy of long-term treatment with either 17(R)HDoHE or AT-RvD1 was partly related to decreased production of TNF-α and IL-1β in rat hind paw. CONCLUSIONS AND IMPLICATIONS Our findings provide fresh evidence for the anti-hyperalgesic properties of 17(R)HDoHE and its pro-resolution metabolite AT-RvD1. Such lipid mediators might be useful for treating pain associated with acute or chronic inflammation. LINKED ARTICLE This article is commented on by Xu and Ji, pp. 274–277 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2011.01348.x

Analgesic Effects of Callus Culture Extracts from Selected Species of Phyllanthus in Mice

Abstract: — The aim of this study was to evaluate the analgesic effect of the methanolic extract from callus culture of Phyllanthus tenellus, P. corcovadensis and P. niruri in several models of pain in mice. The extracts (medium containing 2,4-dichlorophenoxyacetic acid) of P. corcovadensis, P. niruri and P. tenellus (3–90 mg kg−1, i.p.) caused graded inhibition of abdominal constrictions induced by acetic acid (0·6%), with ID50 (i.e. dose that reduced response of control by 50%) values of about 30, 19 and >30 mg kg−1, respectively. The extract of callus of Phyllanthus obtained in indole-3-butyric acid and indole-3-acetic acid media (3–90 mg kg−1, i.p.) caused a similar analgesic effect. In the formalin test, the extract of P. tenellus obtained in indole butyric acid medium (3–100 mg kg−1, i.p.) inhibited only the second phase of formalin-induced pain with an ID50 value of about 100 mg kg−1. Both the indole acetic acid and indole butyric acid methanolic extracts of P. tenellus and P. corcovadensis (10–100 mg kg−1, i.p.) dose-dependently inhibited both phases of formalin-induced pain (ID50 values for the second phase were approx. 100 and 52 mg kg−1, respectively). However, the extract of callus from Phyllanthus failed to affect formalin-induced paw oedema, as well as the response to radiant heat in the tail-flick test. In addition, the analgesic effect of morphine, but not the analgesic effects caused by Phyllanthus callus extract, was fully antagonized by naloxone. Preliminary phytochemical analysis revealed the presence of several compounds having no apparent relationship with alkaloids or flavonoids but showing the presence of phenols. These results indicate that, similar to previous reported data from the extract of P. corcovadensis, the methanolic extracts of callus culture of P. niruri, P. corcovadensis and P. tenellus exhibit potent analgesic properties against neurogenic and inflammatory pain that seem to be unrelated to the activation of opioid mechanisms.

Study of measured pulsar masses and their possible conclusions

Abstract: We study the statistics of 61 measured masses of neutron stars (NSs) in binary pulsar systems, including 18 double NS (DNS) systems, 26 radio pulsars (10 in our Galaxy) with white dwarf (WD) companions, 3 NSs with main-sequence companions, 13 NSs in X-ray binaries, and one undetermined system. We derive a mean value of M = 1.46 +/- 0.30 M-circle dot. When the 46 NSs with measured spin periods are divided into two groups at 20 milliseconds, i.e., the millisecond pulsar (MSP) group and others, we find that their mass averages are, respectively, M = 1.57 +/- 0.35 M-circle dot and M = 1.37 +/- 0.23 M-circle dot. In the framework of the pulsar recycling hypothesis, this suggests that an accretion of approximately similar to 0.2 M-circle dot is sufficient to spin up a neutron star and place it in the millisecond pulsar group. Based on these estimates, an approximate empirical relation between the accreting mass (Lambda M) of recycled pulsar and its spin period is proposed as Delta M = 0.43 (M-circle dot)(P/1 ms)(-2/3). If we focus only on the DNS, the mass average of all 18 DNSs is 1.32 +/- 0.14 M-circle dot, and the mass averages of the recycled DNSs and the non-recycled NS companions are, respectively, 1.38 +/- 0.12 M-circle dot and 1.25 +/- 0.13 M-circle dot. This is consistent with the hypothesis that the masses of both NSs in DNS system have been affected by accretion. The mass average of MSPs is higher than the Chandrasekhar limit 1.44 M-circle dot, which may imply that most of binary MSPs form via the standard scenario by accretion recycling. If we were to assume that the mass of a MSP formed by the accretion induced collapse (AIC) of a white dwarf must be less than 1.35 M-circle dot, then the portion of the binary MSPs involved in the AICs would not be higher than 20%, which imposes a constraint on the AIC origin of MSPs. With accreting mass from the companion, the nuclear matter composition of MSP may experience a transition from the "soft" equation of state (EOS) to a "stiff" EOS or even neutron to quark matter.

Two new ternary complexes of copper(II) with tetracycline or doxycycline and 1,10-phenanthroline and their potential as antitumoral: cytotoxicity and DNA cleavage.

Abstract: This paper reports on the synthesis and characterization of two new ternary copper(II) complexes: [Cu(doxycycline)(1,10-phenanthroline)(H(2)O)(ClO(4))](ClO(4)) (1) and [Cu(tetracycline)(1,10-phenanthroline)(H(2)O)(ClO(4))](ClO(4)) (2). These compounds exhibit a distorted tetragonal geometry around copper, which is coordinated to two bidentate ligands, 1,10-phenanthroline and tetracycline or doxycyline, a water molecule, and a perchlorate ion weakly bonded in the axial positions. In both compounds, copper(II) binds to tetracyclines via the oxygen of the hydroxyl group and oxygen of the amide group at ring A and to 1,10-phenanthroline via its two heterocyclic nitrogens. We have evaluated the binding of the new complexes to DNA, their capacity to cleave it, their cytotoxic activity, and uptake in tumoral cells. The complexes bind to DNA preferentially by the major groove, and then cleave its strands by an oxidative mechanism involving the generation of ROS. The cleavage of DNA was inhibited by radical inhibitors and/or trappers such as superoxide dismutase, DMSO, and the copper(I) chelator bathocuproine. The enzyme T4 DNA ligase was not able to relegate the products of DNA cleavage, which indicates that the cleavage does not occur via a hydrolytic mechanism. Both complexes present an expressive plasmid DNA cleavage activity generating single- and double-strand breaks, under mild reaction conditions, and even in the absence of any additional oxidant or reducing agent. In the same experimental conditions, [Cu(phen)(2)](2+) is approximately 100-fold less active than our complexes. These complexes are among the most potent DNA cleavage agents reported so far. Both complexes inhibit the growth of K562 cells with the IC(50) values of 1.93 and 2.59 μmol L(-1) for compounds 1 and 2, respectively. The complexes are more active than the free ligands, and their cytotoxic activity correlates with intracellular copper concentration and the number of Cu-DNA adducts formed inside cells.

BSA adsorption on differently charged polystyrene nanoparticles using isothermal titration calorimetry and the influence on cellular uptake.

Abstract: BSA adsorption onto negatively and positively charged polystyrene nanoparticles was investigated. The nanoparticles were characterized in terms of particle size, zeta potential, surface group density, and morphology. The adsorption behavior of BSA on the particle surface, as a function of pH and overall charge of the particle, was studied using ITC. Different thermodynamic data such as enthalpy changes upon binding and stoichiometry of the systems were determined and discussed. The degree of surface coverage with BSA was calculated using the thermodynamic data. The cellular uptake of particles before and after BSA adsorption was studied using HeLa cells in the presence and absence of supplemented FCS in the cell culture medium.

Discriminação racial e saúde: uma revisão sistemática de escalas com foco em suas propriedades psicométricas (Racial discrimination and health: a systematic review of scales with a focus on their psychometric properties)

Abstract: A literatura abordando o uso da variavel raca no estudo de causas das iniquidades raciais em saude e caracterizada por uma profunda discussao sobre os problemas envolvidos na interpretacao de associacoes estatisticas como relacoes de causa e efeito. Em contrapartida, um numero menor de estudos tem abordado o uso de escalas de discriminacao racial para estimar os efeitos deste tipo de tratamento injusto sobre a saude, e nenhum deles realizou uma avaliacao abrangente das propriedades psicometricas destes instrumentos. O objetivo deste trabalho foi revisar sistematicamente a literatura sobre escalas de discriminacao racial, com vistas a descrever seus processos de desenvolvimento e prover uma sintese de suas propriedades psicometricas. Uma busca eletronica nas bases de dados PubMed, LILACS, PsycInfo, Scielo, Scopus e Web of Science foi realizada sem qualquer restricao, utilizando-se vocabulario livre e controlado. Apos identificar 3.060 referencias, 24 escalas foram incluidas na revisao. Apesar de a discriminacao racial constituir um tema de relevância internacional, 23 (96%) escalas foram desenvolvidas nos Estados Unidos. A maior parte dos estudos (67%, N = 16) foi publicada nos ultimos 12 anos, documentando tentativas iniciais de desenvolvimento de escalas, com uma escassez de investigacoes sobre o refinamento ou a adaptacao trans-cultural destes instrumentos. As propriedades psicometricas relatadas foram boas; dezesseis entre todas as escalas apresentaram confiabilidade acima de 0,7, 19 entre 20 instrumentos confirmaram, pelo menos, 75% das hipoteses relacionadas aos construtos avaliados e a estrutura dimensional foi corroborada por analises fatoriais em 17 de 21 escalas. Entretanto, pesquisadores independentes raramente examinaram estas escalas. O uso de terminologia racial e como isto pode afetar o relato de experiencias de discriminacao racial nao foi extensamente avaliado. A necessidade de considerar outras formas de tratamento discriminatorio como exposicoes danosas a saude igualmente importantes e a ideia de um instrumento universal, adaptavel a diferentes contextos socioculturais, deveriam ser discutidas entre os pesquisadores deste emergente campo de investigacao. ABSTRACT – The literature addressing the use of the race variable to study causes of racial inequities in health is characterized by a dense discussion on the pitfalls in interpreting statistical associations as causal relationships. In contrast, fewer studies have addressed the use of racial discrimination scales to estimate discrimination effects on health, and none of them provided a thorough assessment of the scales’ psychometric properties. Our aim was to systematically review self-reported racial discrimination scales to describe their development processes and to provide a synthesis of their psychometric properties. A computer-based search in PubMed, LILACS, PsycInfo, Scielo, Scopus and Web of Science was conducted without any type of restriction, using search queries containing free and controlled vocabulary. After initially identifying 3,060 references, 24 scales were included in the review. Despite the fact that discrimination stands as topic of international relevance, 23 (96%) scales were developed within the United States. Most studies (67%, N = 16) were published in the last 12 years, documenting initial attempts at scale development, with a dearth of investigations on scale refinements or cross-cultural adaptations. Psychometric properties were acceptable; sixteen of all scales presented reliability scores above 0.7, 19 out of 20 instruments confirmed at least 75% of all previously stated hypotheses regarding the constructs under consideration, and conceptual dimensional structure was supported by means of any type of factor analysis in 17 of 21 scales. However, independent researchers, apart from the original scale developers, have rarely examined such scales. The use of racial terminology and how it may influence self-reported experiences of discrimination has not yet been thoroughly examined. The need to consider other types of unfair treatment as concurrently important health-damaging exposures, and the idea of a universal instrument, which would permit cross-cultural adaptations, should be discussed among researchers in this emerging field of inquiry. Key words: Race Relations; Prejudice; Causality; Questionnaires; Psychometrics

Minimising the stress of weaning of beef calves: a review.

Abstract: Weaning of beef calves is usually done abruptly and early compared to the natural weaning of the species, and is associated with simultaneous exposure of calves to a range of social and environmental stressors. Behavioural and physiological responses to weaning indicate detrimental effects on the welfare of these animals. The development and assessment of weaning methods aiming at reducing or avoiding this problem must be supported by scientific knowledge of the morphological, physiological and psychological mechanisms involved in the establishment, maintenance and braking of the cow-calf bond. Solutions also depend on the understanding of the various stressors associated with weaning, among which are the change in diet, cessation of nursing, separation from the dam, the change to a new spatial environment and the need for social reorganization following removal of the adults from the group. This review discusses these issues and assesses the effectiveness of the methods so far proposed for improving the welfare of beef calves during the weaning period.