254 research outputs found

    On the true identity of Mendoncia “stellate” trichomes

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    ABSTRACT The present survey of leaf-blade trichomes of Mendoncia used SEM and light microscopy to investigate the diversity of trichome types in Neotropical and Paleotropical species of the genus. The eglandular trichomes are filiform, uniseriate, with asymmetric epidermal cells arranged radially around the trichome, these epidermal cells may be short or elongated, oriented in two groups. These cells, when elongated, are covered with epicuticular wax, forming smooth thick plates. African species have dendritic but not stellate trichomes. Character states such as number and length of basal cells were shown to overlap within the same species and therefore their use in isolation is not recommended for subgeneric classification of Mendoncia. Neotropical Mendoncia trichomes with well-developed epidermal cells arranged radially around the trichome appear to be unique to this group, without parallel in other plant families

    Essential oils from leaves of cryptocarya spp from the atlantic rain forest

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    The essential oils from leaves of four Cryptocarya spp endemic in the Brazilian Atlantic rain forest were obtained by hydrodistillation and shown by GC-MS analysis to contain mono and sesquiterpenes. The major components of the oil of Cryptocarya moschata were linalool (34.3%), a-terpinene (17.0%), g-terpinene (10.4%), 1,8-cineole (5.8%) and trans-ocimene (4.8%), whilst those of C. botelhensis were a-pinene (22.7%), b-pinene (9.2%), trans-verbenol (8.4%), trans-pinocarveol (5.5%) and myrtenal (5.4%). The principal compounds of C. mandioccana oil were b-caryophyllene (13.8%), spathulenol (10.2%), caryophyllene oxide (7.8%), d-cadinene (6.9%) and bicyclogermacrene (6.4%), whilst those of C. saligna were germacrene D (15.5%), bicyclogermacrene (13.8%), spathulenol (11.8%) and germacrene B (5.7%)

    Essential oils from leaves of cryptocarya spp from the atlantic rain forest

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    The essential oils from leaves of four Cryptocarya spp endemic in the Brazilian Atlantic rain forest were obtained by hydrodistillation and shown by GC-MS analysis to contain mono and sesquiterpenes. The major components of the oil of Cryptocarya moschata were linalool (34.3%), a-terpinene (17.0%), g-terpinene (10.4%), 1,8-cineole (5.8%) and trans-ocimene (4.8%), whilst those of C. botelhensis were a-pinene (22.7%), b-pinene (9.2%), trans-verbenol (8.4%), trans-pinocarveol (5.5%) and myrtenal (5.4%). The principal compounds of C. mandioccana oil were b-caryophyllene (13.8%), spathulenol (10.2%), caryophyllene oxide (7.8%), d-cadinene (6.9%) and bicyclogermacrene (6.4%), whilst those of C. saligna were germacrene D (15.5%), bicyclogermacrene (13.8%), spathulenol (11.8%) and germacrene B (5.7%).503507Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Exercise training in the aerobic/anaerobic metabolic transition prevents glucose intolerance in alloxan-treated rats

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    <p>Abstract</p> <p>Background</p> <p>Ninety percent of cases of diabetes are of the slowly evolving non-insulin-dependent type, or Type 2 diabetes. Lack of exercise is regarded as one of the main causes of this disorder. In this study we analyzed the effects of physical exercise on glucose homeostasis in adult rats with type 2 diabetes induced by a neonatal injection of alloxan.</p> <p>Methods</p> <p>Female Wistar rats aged 6 days were injected with either 250 mg/kg of body weight of alloxan or citrate buffer 0.01 M (controls). After weaning, half of the animals in each group were subjected to physical training adjusted to meet the aerobic-anaerobic metabolic transition by swimming 1 h/day for 5 days a week with weight overloads. The necessary overload used was set and periodically readjusted for each rat through effort tests based on the maximal lactate steady state procedure. When aged 28, 60, 90, and 120 days, the rats underwent glucose tolerance tests (GTT) and their peripheral insulin sensitivity was evaluated using the HOMA index.</p> <p>Results</p> <p>The area under the serum glucose curve obtained through GTT was always higher in alloxan-treated animals than in controls. A decrease in this area was observed in trained alloxan-treated rats at 90 and 120 days old compared with non-trained animals. At 90 days old the trained controls showed lower HOMA indices than the non-trained controls.</p> <p>Conclusion</p> <p>Neonatal administration of alloxan induced a persistent glucose intolerance in all injected rats, which was successfully counteracted by physical training in the aerobic/anaerobic metabolic transition.</p

    Didactic Sequence for Teaching Exponential Function

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    This paper presents a methodological proposal for the teaching of exponential function, resulting from the application of a didactic sequence involving exponential function, where evidence of learning and the consolidation and application of mathematical concepts in problem solving were identified and analyzed. The Didactic Engineering of Michèle Artigue (1988) was used as a research methodology. As theoretical contributions that guided and enabled the development of the research, we chose the use of Mathematical Investigation in the classroom; Didactic Sequence in the conception of Zabala (1999); the Articulated Units of Conceptual Reconstruction proposed by Cabral (2017) and assumptions of Vygotsky\u27s theory. A didactic sequence composed of five UARC\u27s was elaborated to work the exponential function, with a view to minimizing the difficulties naturally imposed by the content to be explained. Microgenetic analysis of verbal interactions between teacher and students was used to analyze the results of the application. The results show that the students participating in the experiment showed evidence of learning, recorded during the process, and began to have a good understanding of the concepts and properties related to the topic, in addition to a good performance in carrying out the activities, facts that corroborate the potential of the didactic sequence proposed herein

    Pediatric tuberculosis in the metropolitan area of Rio de Janeiro

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    Aim: To evaluate the clinical characteristics, diagnostic approach, and treatment outcomes of tuberculosis (TB) in children living in a high-burden metropolitan area. Methods: This was a retrospective study, based on a medical chart review, involving children under 15 years old treated for TB between 2007 and 2016, in four primary health units (PHU) and three reference centers (RC) in five cities of Rio de Janeiro metropolitan area. Factors associated with TB treatment setting, microbiological diagnosis, and treatment outcomes were evaluated. Results: A total of 544 children were enrolled; 71% were treated in PHU, 36% were under 5 years old, and 72% had pulmonary TB (PTB). The HIV prevalence was 10% (31/322). Fifty-three percent had at least one microbiological test for TB, 68% of them (196/287) had TB confirmed. Among 222 children with previous TB contact, information on LTBI was available for 78 (35%), and only 17% (13/78) were treated. Extrapulmonary TB (56% vs 32%), microbiologically confirmed TB (77% vs 60%), and HIV positivity (18.5% vs 4.0%) were significantly more frequent in RC. Treatment in RC (odds ratio (OR) 3.08, 95% confidence interval (CI) 1.74–5.44) and PTB (OR 2.47, 95% CI 1.34–4.56) were independently associated with a microbiological diagnosis of TB. The treatment success rate was 85%. In the logistic regression analysis, HIV-infected children had a 2.5-fold higher risk of an unfavorable outcome (OR 2.53, 95% CI 1.0–6.38; p = 0.05). Conclusions: Opportunities for TB prevention and early TB treatment are missed due to suboptimal close contact screening. Microbiological diagnosis of TB and drug susceptibility testing in children should be made available through more sensitive and accessible tests
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