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SMA actuators are a group of lightweight actuators that offer advantages over conventional technology and allow for simple and compact solutions to the increasing demand for electrical actuation. In particular, an increasing number of SMA torsional actuator applications have been published recently due to their ability to supply rotational motion under load, resulting in advantages such as module simplification and the reduction of overall product weight. This paper presents the conceptual design, operating principle, experimental characterization and working performance of torsional actuators applicable in active rudder in aeronautics. The proposed application comprises a pair of SMA torsion springs, which bi-directionally actuate the actuator by Joule heating and natural cooling. The experimental results confirm the functionality of the torsion springs actuated device and show the rotation angle of the developed active rudder was about 30° at a heating current of 5 A. After the design and experiment, one of their chief drawbacks is their relatively slow operating speed in rudder positioning, but this can be improved by control strategy and small modifications to the actuator mechanism described in this work.
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Flexible films of a conductive polymer nanocomposite-based castor oil polyurethane (PUR), filled with different concentrations of carbon black (CB) nanoparticles or multiwall carbon nanotubes (MWCNTs), were obtained by a casting method. The piezoresistive, electrical, and dielectric properties of the PUR/MWCNT and PUR/CB composites were compared. The dc electrical conductivity of both PUR/MWCNT and PUR/CB nanocomposites exhibited strong dependences on the concentration of conducting nanofillers. Their percolation thresholds were 1.56 and 1.5 mass%, respectively. Above the threshold percolation level, the electrical conductivity value increased from 1.65 × 10-12 for the matrix PUR to 2.3 × 10-3 and 1.24 × 10-5 S/m for PUR/MWCNT and PUR/CB samples, respectively. Due to the better CB dispersion in the PUR matrix, the PUR/CB nanocomposite exhibited a lower percolation threshold value, corroborated by scanning electron microscopy images. The real part of the alternating conductivity of the nanocomposites was in accordance with Jonscher's law, indicating that conduction occurred by hopping between states in the conducting nanofillers. The piezoresistive properties were investigated under tensile cycles. The nanocomposites exhibited piezoresistive responses and, thus, could be used as piezoresistive sensors.
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In the present study, the volatile components and cytotoxic, antibacterial, antioxidant, and antiprotozoal activities of the essential oil obtained from the leaves of Eugenia stipitata McVaugh (Myrtaceae) grown in the Brazilian Northeast region (Araripe) were investigated. The essential oil was obtained by hydrodistillation. The leaves of E. stipitata provided an oil yield of 0.13 ± 0.01% (w/w). The volatile compounds in the essential oil of E. stipitata were analysed using gas chromatography, and the volatile chemical composition was mainly composed of ß-eudesmol (15.28%), γ-eudesmol (10.85%), elemol (10.21%) and caryophyllene oxide (6.65%). The essential oil of E. stipitata was highly selective against Leishmania braziliensis and L. infantum promastigotes. The essential oil exhibited good antibacterial activity. E. stipitata essential oil showed low free-radical scavenging activity. Our results suggest that the E. stipitata essential oil is a relevant source of the primary compounds required for the development of antibacterial and antiprotozoal drugs.
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Sexual violence is ubiquitous in the history of human relationships, with the victim being perceived as responsible for their own misfortune. This phenomenon is labelled secondary victimization and is manifested in blaming, minimizing the suffering, and avoiding the victim. This article presents evidence of the validity of a scale that measures individual differences in these three types of secondary victimization of rape victims. In Study 1, we developed the scale items and analyzed their content validity. In Study 2, we carried out an exploratory analysis of its factorial structure and verified the set-up of the items in three theoretically predicted factors (blaming, minimizing the suffering, and avoiding the victim), which had convergent validity with the Rape Myth Acceptance Scale, and discriminant validity with the Big Five Personality Traits, in addition to having concurrent validity with the Belief in a Just World Scale (BJWS). In Study 3, we confirmed this tri-factor structure using confirmatory analysis. In Study 4, we analyzed the predictive validity of the Secondary Victimization Scale (SVS), proposing the hypothesis that secondary victimization mediates the effect of BJWS on the participants' behavior towards a rape victim. The summary of the results shows consistent evidence of the SVS's validity.
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Vítimas de Crime , Estupro , Delitos Sexuais , HumanosRESUMO
Casual sexual relationships (CSRs) are frequent relationship experiences in young adulthood that provide opportunities for many to explore sexual relationships and to construct their sexual identity. Empirical research on casual sex is still lacking outside North-American countries, despite evidence pointing to the need to contextualize sexual interactions in their own sociocultural context. In order to better understand casual sexual relationships, these should be examined in with novel samples in other countries where a "hookup culture" as it is described in the North-American university campus is apparently absent. Through a qualitative study, we explored what casual sexual relationships consist of according to the perceptions of Portuguese college students (N = 35). The thematic analysis of eight focus group interviews resulted in the generation of six themes, three of which are presented here: (1) What CSRs are, regarding features and types of CSRs, (2) Why individuals engage in CSRs, focusing on positive and negative motivations, and (3) What one gets from CSRs, focusing on positive and negative outcomes of CSRs. Our findings showed that Portuguese emerging adults are familiarized with CSRs, particularly with one-night stand, friends with benefits and "curte"/hookup. Sexual interactions associated with other CSRs, such as booty call or fuck buddies, were mentioned but rarely associated with a distinctive label and established characteristics. Participants described the CSRs in a partially overlapping manner presenting some areas of ambiguity, such as with regard to sexual exclusivity and still-unlabeled sexual interactions. CSRs are generally evaluated as positively motivated and mainly beneficial. This study adds to the literature around casual sexual relationships by exploring and describing CSRs in a different sociocultural context, as well as indicating directions for future research in order to better prepare and empower young adults in their sexual and relational trajectories.
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This article aims to examine the role of Belief in a Just World (BJW) in the legitimation of economic inequality. Using data from 27 European countries (N=47,086), we conducted multilevel analyses and found that BJW positively predicted the legitimation of economic inequality, measured by three indicators: the perceived fairness of the overall wealth inequality, and the fairness of the earnings made by the Top 10% and the Bottom 10% of society. These results persisted after controlling for individual- and country-level variables. Moreover, the BJW effect was stronger on the legitimation of the Bottom 10% incomes, compared to the legitimation of the Top 10%. We also found that economic inequality at the country-level reduced the BJW effect on legitimation of inequality. Finally, BJW displayed a negative indirect effect on support for redistribution, via the legitimation of economic inequalities.
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Renda , Europa (Continente) , Humanos , Fatores SocioeconômicosRESUMO
Casual sexual relationships (CSR) are increasingly common but limited empirical research has addressed their terminology and distinctive characteristics. This study sought to identify the most clear-cut terms and to consider how culture-sensitive characteristics distinguish casual sexual relationships among Portuguese emerging adults (N = 262, 18-29 years old). We combined two qualitative studies - one by association and another by free recall - to ascertain the clarity of the terms, plus a quantitative study to further characterize and differentiate them. Participants were asked to match descriptions of CSRs with the respective terms by which they are known (Study 1). The same was investigated using an evocation task requesting that participants produce the terms by which the described CSRs are known (Study 2). Binary logistic regressions were performed to analyze the associations between encounters and labels chosen, taking the effect of gender and age into account. In the third study, participants rated the degree to which eight characteristics were present in the types of CSR, a simultaneous task that led to greater understanding of their descriptive and differentiating characteristics. Multivariate analysis of variance was used, with gender and age as covariates. We conclude that two types of CSR - friends with benefits and one-night stand - and, to a lesser extent, making out, are understood and associated with consensual labels, also found by free-recall. These CSRs proved to be distinct, as they are understood as more different than similar in a set of psychoemotional, behavioral, and sexual characteristics. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12119-021-09859-0.
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Abstract: Parasites are an important component of the global biomass, having significant roles in several regulatory mechanisms in the ecosystem. Parasitism is one of the most common ecological interactions on the planet. Studies have shown that the helminth fauna of only 8% of amphibian species in Brazil have been studied, and this percentage is lower for the Odontophrynidae family, with only four of the 50 species kown to occur in Brazil having been investigated. Here, we present the helminth fauna of Proceratophrys ararype, an anuran endemic to the "Brejo de Altitude" Chapada do Araripe (Araripe Plateau), northeastern Brazil. The infection parameters analyzed were prevalence, mean intensity of infection and mean abundance of parasites. We used the Pearson's linear correlation coefficient to check the correlations between the abundance of the parasites with the snout-vent length (SVL) of hosts. To verify the degree of aggregation of parasites in hosts, we used the dispersion index. Out of 40 specimens examined, 19 specimens were infected with at least one parasite. The overall prevalence was 47.5% with a mean infection intensity of 18.93 ± 10.77. The endoparasitic community associated with P. ararype consisted of six species of parasites, with Falcaustra mascula having the highest prevalence (25%). Most parasites had a uniform dispersion index in the hosts and their abundance was unrelated to host size. Here, we also present a compilation of all parasites associated with host species of the genus Proceratophrys from South America. Overall, we found 23 species of parasites associated with five host species (P. ararype, P. appendiculata, P. boiei, P. cristiceps, P. mantiqueira). Of these, two species of parasites (Oswaldocruzia mazzai and Strongyloides sp.) represent new records for the genus Proceratophrys. Our results demonstrate the lack of studies on amphibian helminth fauna and fill an important knowledge gap on the diversity of parasites of Proceratophrys ararype, an endemic frog from the Araripe Plateau, northeastern Brazil.
Resumo: Os parasitas são um componente importante da biomassa global, tendo papel significativo em vários mecanismos reguladores no ecossistema. O parasitismo é uma das interações ecológicas mais comuns no planeta. Estudos demonstraram que somente 8% da fauna de helmintos das espécies de anfíbios que ocorrem no Brasil foi estudada, sendo esta porcentagem mais baixa para a família Odontophrynidae, tendo sido investigadas apenas quatro das 50 espécies com ocorrência conhecida para o Brasil. Aqui, apresentamos a helmintofauna de Proceratophrys ararype, um anuro endêmico do "Brejo de Altitude" Chapada do Araripe, nordeste do Brasil. Os parâmetros de infecção analisados foram prevalência, intensidade média de infecção e abundância média de parasitas. Utilizamos o coeficiente de correlação linear de Pearson para verificar as correlações entre a abundância dos parasitas com o comprimento rostro-cloacal dos hospedeiros. Para verificar o grau de agregação dos parasitas nos hospedeiros, utilizamos o índice de dispersão. Dos 40 espécimes examinados, 19 estavam infectados com pelo menos um parasita. A prevalência geral foi de 47.5% com intensidade média de infecção de 18.93 ± 10.77. A comunidade endoparasitária associada a P. ararype constituiu de seis espécies de parasitas, com Falcaustra mascula tendo a maior prevalência (25%). A maioria dos parasitas apresentaram índice de dispersão uniforme nos hospedeiros e sua abundância não esteve relacionada ao tamanho do hospedeiro. Aqui, nós também apresentamos uma compilação de todos os parasitas associados as espécies de hospedeiros do gênero Proceratophrys na América do Sul. No geral, nós encontramos 23 espécies de parasitas associadas a cinco espécies de hospedeiros (P. ararype, P. appendiculata, P. boiei, P. cristiceps, P. mantiqueira). Destas, duas espécies de parasitas (Oswaldocruzia mazzai e Strongyloides sp.) representam novos registros para o gênero Proceratophrys. Nossos resultados demonstram a carência de estudos sobre a helmintofauna de anfíbios e preenchem uma importante lacuna de conhecimento sobre a diversidade de parasitas de Proceratophrys ararype, um sapo endêmico do Planalto do Araripe, nordeste do Brasil.
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AIM: This study investigates the joint role of volitional predictors of oral hygiene behaviours of flossing and brushing in adults with gingivitis, framed by the Health Action Process Approach model (HAPA). MATERIALS AND METHODS: In a longitudinal online survey, 201 participants aged 18-75, of which 56.7% were women, completed assessments at baseline(T1), 2 weeks(T2) and 4 months(T3). Oral hygiene behaviours(OH) (brushing and flossing) and social cognitive determinants of behaviour in the HAPA: action and maintenance self-efficacy(ASE & MSE), intention(INT), coping planning(CP) and action control(AC) were evaluated. Structural equation modelling was used to test a series of three nested models. In Model 1, action self-efficacy would determine MSE and INT, and INT would determine OH; in Model 2, INT would determine both CP and AC and the two OH behaviours; and in Model 3, CP and AC would be sequential mediators between INT and OH. RESULTS: Model 3, predicting a mediating process from intention to behaviour via coping planning and action control, showed the best fit according to the fit indices and explained more of the variance in dental hygiene. The mediating role of coping planning and action control between intention and oral hygiene behaviours was thus confirmed. Importantly, coping planning did not mediate between intention and oral hygiene behaviours, which means that oral hygiene intention influences action control through coping planning, and both sequentially mediate this influence on behaviour. CONCLUSIONS: For individuals who are not yet following the recommendations for specific oral hygiene behaviours, coping planning and action control represent psychological mechanisms by which intentions are put into practice.
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Gengivite , Higiene Bucal , Adaptação Psicológica , Adolescente , Adulto , Idoso , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Intenção , Masculino , Pessoa de Meia-Idade , Autoeficácia , Escovação Dentária , Adulto JovemRESUMO
Objective: The main purpose of this study was to investigate the factor structure of the Beck Depression Inventory - Second Edition (BDI-II) in a sample of adults. Specifically, we evaluated the BDI-II based on confirmatory factor analysis of different measurement models, and compared the optimal factor structure of the BDI-II by gender using measurement invariance analysis. Method: A cross-sectional survey with 717 community-dwelling adults was conducted. The Brazilian Portuguese version of the BDI-II was administered. Seven different models (one-, two-, three-factor models and their bifactor structures) were tested through CFA. CFA and multigroup analysis were executed with the software MPLUS (Weighted Least Squares Estimator - WLSMV). Results: Four bifactor models reached acceptable fit indices. A bifactor model with two specific factors (Cognitive-Affective, and Somatic-Affective) provided the best fit to the data. The multigroup analysis of this model demonstrated invariance by gender. Conclusions: Our findings support the use of the total BDI-II score to identify depressive symptoms, including gender comparisons. Since a bifactor structure fit the data better, the scores of the specific factors should not be used as the first choice, or at least should be used with caution. The analysis of the severity of depression, based on a total score, seems to be the most appropriate option.
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AIM: To investigate the relationship between the microbiota of periodontal pockets (PP) and root canals (RC) in dogs submitted to experimental periodontal disease (ExPD). METHODS: ExPD was induced by combining cotton and wire ligatures. After 125 days, microbiological samples were collected from PP and RC. Strains isolated from 19 teeth were submitted to DNA extraction, 16S rRNA gene amplification and gene sequencing. Pearson's χ2 - and Fisher's exact tests and McNemar's test were used when appropriate. RESULTS: The number of species in PP was greater than in RC, with prevalence of obligate anaerobes and Gram-negative bacteria. In the PP predominated Fusobacterium necrophorum, Porphyromonas gingivalis, Prevotella loescheii, Campylobacter gracilis and Veillonella parvula. In the RC samples, 9 had microbial growth, with predominance of the following genera: Staphylococcus, Streptococcus and Neisseria. Eight genera were common to both sites in the same tooth. PP presented a greater number of species than the RC. No significant difference was observed in the species found in PP and RC in the same tooth. CONCLUSION: Microbial composition of the RC could be modulated by the presence of periodontal disease, especially in cases of severe periodontal destruction. RC microbiota was less complex and diverse than the PP.
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Microbiota , Doenças Periodontais , Animais , Cavidade Pulpar , Cães , Bolsa Periodontal , RNA Ribossômico 16SRESUMO
Using representative probabilistic samples of Portuguese citizens and framed by an intergroup perspective, we carried out two studies aiming to address how national identification and belief in a just world (BJW) jointly predict secondary victimization of an ingroup as a whole (specifically ingroup blame). We conducted Study 1 (N = 779) in 2014, at the height of the European austerity policies imposed on Portugal by an institutional outgroup, specifically the Troika (the European Union, the European Central Bank, and the International Monetary Fund). Study 2 (N = 1140) was conducted after the Troika intervention. An environment of ongoing ingroup suffering caused by an outgroup is more threatening for the BJW of individuals who are more identified with the ingroup. We therefore predicted and found that BJW was positively associated with ingroup blame in participants higher in national identification when the victimization provoked by an institutional outgroup was higher (Study 1). However, when the suffering caused by the outgroup decreased, the association between BJW and secondary victimization was not moderated by individuals' national identification (Study 2). Indeed, a three-way interaction was found between BJW, national identification, and social context (high vs. low victimization). These results are an important contribution for the literature about justice motivation in terms of intergroup relations, because they show that secondary victimization produced by a threat to BJW has a group-based identity function.
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OBJECTIVE: Scorpion stings are registered worldwide, but the incidence and the features of the envenomations vary depending on the region. The aim of this review was to summarize the epidemiological, clinical, diagnostic, and therapeutic data worldwide regarding humans stung by scorpions. METHODS: A systematic review of the literature was conducted through the online databases of the Virtual Health Library (VHL), which hosts Medline and the Latin American and Caribbean Center on Health Sciences Informational (LILACS) database. We selected articles published between January 1, 2002 and July 31, 2014. RESULTS: Scorpion envenomation reports were found throughout the world, mainly in subtropical and tropical regions. The clinical manifestations were sympathetically and parasympathetically mediated, depending on the species of scorpion. Some of the most common severe complications of scorpionism included respiratory distress syndrome, pulmonary edema, cardiac dysfunction, impaired hemostasis, pancreatitis, and multiple organ failure. Scorpion envenomation could be classified as mild, moderate, and severe, and the therapeutic approach was based on the case severity. The treatment comprised 3 components: symptomatic measures, vital functions support, and injection of antivenom. Moreover, the time that elapsed between the sting and administration of the appropriate medical care was extremely important to the patient's prognosis. CONCLUSIONS: The large number of scorpion stings worldwide is concerning and reaffirms the need for new prevention measures and policies to reduce the incidence, prevalence, morbidity, and mortality rates from these poisonous arachnids.
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Picadas de Escorpião/epidemiologia , Picadas de Escorpião/terapia , Animais , Antivenenos/uso terapêutico , Humanos , Picadas de Escorpião/etiologia , Escorpiões , Clima TropicalRESUMO
BACKGROUND: In order to understand the mechanisms involved in how overweight adolescents adhere to weight management and perceive its benefits, a few variables have been identified, namely, body mass index (BMI), body self-esteem (BSE) and positive perspective of life (PPL). METHODS: In a sample of 112 adolescents, we investigated whether BMI would predict adolescents' self-efficacy/adherence (SEA) to weight management and perception of its benefits. A structural equation modeling approach was chosen. We hypothesized that perceived quality of life (PQL) would mediate the relationships between BMI and SEA and between BMI and perception of benefits (PB). RESULTS: The results suggested that BMI is not directly associated with SEA and PB. However, PQL was identified as a mediator between BMI and SEA and PB. CONCLUSION: These findings bring important implications for understanding overweight adolescents' adherence to weight management. There is evidence that adolescents' adherence to weight management and PB are not predicted by their BMI. However, it has been shown that PQL mediates this process. For a long time, health professionals have been too focused on BMI. Time has come to be more focused on quality of life and how to improve it.
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Previous research on the motivation for environmentally responsible behaviour has focused mainly on individual variables, rather than organizational or collective variables. Therefore, the results of those studies are hardly applicable to environmental management. This study considers individual, collective, and organizational variables together that contribute to the management of environmental waste. The main aim is to identify, through the development of a multilevel model, those predictive variables of recycling behaviour that help organizations to increase the recycling rates in their communities. Individual (age, gender, educational level, self-efficacy with respect to residential recycling, individual recycling behaviour), organizational (satisfaction with the quality of the service provided by a recycling company), and collective (community recycling rates, number of inhabitants, community efficacy beliefs) motivational factors relevant to recycling behaviour were analysed. A sample of 1501 residents from 55 localities was surveyed. The results of multilevel analyses indicated that there was significant variability within and between localities. Interactions between variables at the level of the individual (e.g. satisfaction with service quality) and variables at the level of the collective (e.g. community efficacy) predicted recycling behaviour in localities with low and high community recycling rates and large and small populations. The interactions showed that the relationship between self-efficacy and recycling is stronger in localities with weak community efficacy beliefs than in communities with strong beliefs. The findings show that the relationship between satisfaction with service quality and recycling behaviour is stronger in localities with strong community efficacy beliefs than in communities with weaker beliefs and a smaller population. The results are discussed accordingly in relation to theory and possible contribution to waste management. Those findings may be incorporated in national and international environmental policies in order to promote environmentally responsible behaviour in citizenship.
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Reciclagem , Fatores Socioeconômicos , Gerenciamento de Resíduos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Motivação , Satisfação Pessoal , Autoeficácia , Espanha , Inquéritos e QuestionáriosRESUMO
Bright field microscopy and atomic force microscopy techniques are used to investigate morphological properties of synthetic eumelanin, obtained by oxidation of L-DOPA solution, deposited on glass and mica substrates. Deposits of eumelanin are characterized by aggregates with different shape and size. On a micrometric scale, filamentous as well as granular structures are present on glass and mica substrates, with a larger density on the former than on the latter. On a nanometric scale, filamentous aggregates, several microns long and about 100 nm wide and high, and granular aggregates, â¼50 nm high and 100 nm wide, are found on both substrates, whereas point-like deposits less than 10nm high and less than 50 nm wide are found on mica substrate. Dynamic light scattering measurements and atomic force microscopy images support the evidence that eumelanin presents only nanometric point-like aggregates in aqueous solution, whereas such nanoaggregates organize themselves according to granular and filamentous structures when deposition occurs, as a consequence of interactions with the substrate surface.
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Silicatos de Alumínio/química , Vidro/química , Levodopa/química , Melaninas/química , Microscopia de Força Atômica/métodos , Soluções/químicaRESUMO
The aim of this study was to investigate the involvement of noradrenaline, serotonin, and subtypes of glutamate receptors in the antidepressant-like effects of N-acetylcysteine (NAC). The tail suspension test was used with male CF1 albino mice. D,L-α-methyl-ρ-tyrosine and ρ-chlorophenylalanine methyl ester hydrochloride were used as synthesis inhibitors of noradrenaline and serotonin, respectively. N-methyl-D-aspartate (NMDA) and 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f]quinoxaline-2,3-dione were used as an NMDA receptor agonist and an α-amino acid-3-hydroxy-5-methyl-4-isoxazol propionic acid (AMPA) receptor antagonist, respectively. NAC (10, 25, and 50 mg/kg intraperitoneally) significantly (P<0.05) decreased tail suspension test immobility time, whereas pretreatment with D,L-α-methyl-ρ-tyrosine, ρ-chlorophenylalanine methyl ester hydrochloride, and NMDA partially prevented (P<0.05) the effects of NAC (25 mg/kg), and pretreatment with 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f]quinoxaline-2,3-dione completely abolished (P<0.01) this effect. The study corroborates the antidepressant-like effects of NAC in the TST, a model with a well-established predictive value. The results point to the key role of AMPA receptors in the mechanism of the antidepressant-like action of NAC. Like other AMPA potentiators, NAC indirectly modulates noradrenaline and serotonin pathways. It is suggested that the value of NAC as an antidepressant arises from combined and intertwined effects on a variety of pathways.
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Acetilcisteína/farmacologia , Antidepressivos/farmacologia , Elevação dos Membros Posteriores/fisiologia , Receptores de AMPA/agonistas , Acetilcisteína/antagonistas & inibidores , Animais , Antidepressivos/antagonistas & inibidores , Relação Dose-Resposta a Droga , Interações Medicamentosas/fisiologia , Inibidores Enzimáticos/farmacologia , Agonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Fenclonina/análogos & derivados , Fenclonina/farmacologia , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos , N-Metilaspartato/farmacologia , Quinoxalinas/farmacologia , Receptores de AMPA/antagonistas & inibidores , Receptores de AMPA/fisiologia , alfa-Metiltirosina/farmacologiaRESUMO
We isolated two novel cell lines from different types of sporadic human malignant melanoma: the hmel1 line was obtained from a melanoma skin metastasis and the hmel9 cell line from a primary superficial spreading melanoma. The karyotype and pigmentation parameters were assessed in these cell lines. Cytogenetic analysis in early stages of culture revealed that both cell lines had chromosome instability and simultaneous growth of heteroploid subpopulations. The molecular analysis of some genes involved in melanoma showed that both cell lines harbor BRAF mutations. The unpigmented hmel1 and the pigmented hmel9 lines were found to express the tyrosinase gene. The tyrosine hydroxylase activity was detectable only in hmel9 cells and practically absent in the hmel1 cell line. This activity was found to be correlated with the relative tyrosinase protein amount in both melanoma cell lines. The biological behaviour in the two melanoma cell lines, derived from two different types of melanoma lesions displaying distinct clinical and histopathological features, confirms the heterogeneous characteristics of sporadic melanoma. Similarities and/or differences between cell lines extracted from different melanoma cases could be useful in the future for diagnostic, prognostic and therapeutic purposes.
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Linhagem Celular Tumoral/citologia , Regulação Neoplásica da Expressão Gênica , Melanoma Amelanótico/genética , Melanoma/genética , Monofenol Mono-Oxigenase/metabolismo , Proteínas Proto-Oncogênicas B-raf/metabolismo , Neoplasias Cutâneas/genética , Biomarcadores/análise , Instabilidade Cromossômica , Análise Citogenética , Variação Genética , Humanos , Cariotipagem , Melanoma/diagnóstico , Melanoma/patologia , Melanoma Amelanótico/diagnóstico , Melanoma Amelanótico/patologia , Monofenol Mono-Oxigenase/genética , Pigmentação/genética , Poliploidia , Prognóstico , Proteínas Proto-Oncogênicas B-raf/genética , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/patologiaRESUMO
The increased risk of venous thrombosis within and below the inferior vena cava (IVC) is the main long-term complication of IVC filter placement. In this article, we discuss current concepts regarding the incidence, risks, and management of IVC filter thrombosis. Evidence of the association of each of the following factors is reviewed: type and design of the filter device, population demographics, underlying hypercoagulable states/anticoagulation, modality used to assess for thrombosis, and length of time elapsed since filter placement. Certain double-basket filter designs and a hypercoagulable state are associated with increased incidence of IVC filter thrombosis. Most cases of IVC filter thrombosis are asymptomatic. While large series data on the use of magnetic resonance imaging for the detection of filter thrombosis remain unavailable, evidence suggests that contrast-enhanced computed tomography is preferable to Doppler sonography. A proposed algorithm for the management of IVC filter thrombosis is provided.