71 research outputs found
Electronic properties of carbon nanostructures based on bipartite nanocages units
We use first principles simulations to investigate the electronic properties
of a set of carbon nanocages with a bipartite structure. These nanocages are
exclusively formed by hexagonal and tetragonal rings and we show they feature
frontier states with particular symmetries as dictated by well defined rules
based on the size of the structure. We also show that spin-polarized
configuration emerge at the edges of open versions of these 0D systems. These
cages are further proposed as elementary building blocks for periodic 1D and 2D
systems. Even though we find different ways to define the particular bonds
making the connection between the cage-like units, these systems always show a
semiconducting behavior, both for 1D and 2D cases. However, the details of
linking hierarchies interfere in the degree of localization of the frontier
states of these crystalline systems
Central activities of hydroalcoholic extract from Lafoensia pacari A. St.-Hil. stem bark
Lafoensia pacari A. St.-Hil. can be found from Amapá to Rio Grande do Sul states, and also in Paraguay and Bolivia. It is popularly known as pacari or mangava-brava and is used to promote weight loss, as an anti-thermal or tonic, to treat gastritis, ulcers, scarring, itching, discouragement, and cancer. In the open field tests, the hydroalcoholic extract from L. pacari stem bark (HEP) decreased the number of rearings, number of invaded squares, and increased immobility time compared to control animals. In the pentobarbital-induced sleep time test, HEP decreased latency time to sleep and increased sleeping time. In the rota-rod test, no changes in the studied parameters were observed. In the elevated plus maze, HEP increased the percentage time and percentage entries in the open arms, indicating that this extract exerts an anxiolytic-like activity.Lafoensia pacari A. St.-Hil., uma espécie vegetal presente no Brasil, do Amapá ao Rio Grande do Sul, no Paraguai e na Bolívia, é popularmente conhecida como pacari ou mangava-brava e é utilizada como emagrecedor, cicatrizante, antitérmico, tônico e para tratar gastrite, úlcera, coceira, desânimo e câncer. No teste do campo aberto, o tratamento com o extrato hidro-alcoólico de pacari (HEP) reduziu o número de rearings e o número de quadrados invadidos além de aumentar o tempo de imobilidade dos animais em relação ao controle. No sono induzido por pentobarbital sódico o tratamento com HEP causou redução na latência e aumento na duração do sono. No rota-rod, o tratamento com HEP não alterou os parâmetros observados. No teste de labirinto em cruz elevado, com o tratamento com HEP foi observado aumento do percentual do tempo de permanência e de entradas nos braços abertos, caracterizando uma atividade tipo ansiolítica
Radish production under different shading screens and mulching
Shading Screens and mulching may provide a favorable environment for radish growing in regions of adverse climates. This work aimed to evaluate the radish productivity under the influence of different shading screens associated with the presence and absence of mulch in two different years. The experiment was carried out in two different seasons (2017 dry season and 2018 rainy season), in the vegetable garden of Liberdade campus, at the University of International Integration of Afro-Brazilian Lusophony (Unilab), municipality of Redenção-CE. The experimental design was in randomized blocks in a split-plot arrangement, with four repetitions, in which the plots consisted of growing with and without mulching and in the subplots, five shading screens: 50% Black Shading Screen (50% BSS), 50% Red Shading Screen (50% RSS), 30% White Shading Screen (30% WSS), 70% Black Shading Screen (70% BSS) ), and full sunlight (FS). The red shading screens 50% and white 30%, in addition to cultivation under full sunlight, provide higher performance in terms of the number of leaves, tuberous root diameter, tuberous root matter, and the radish crop productivity, regardless of the evaluated period. The applied mulch does not influence the productivity of the rabante, influencing only the gain of dry mass of the aerial part, soluble solids and length of the tuberous root.Shading Screens and mulching may provide a favorable environment for radish growing in regions of adverse climates. This work aimed to evaluate the radish productivity under the influence of different shading screens associated with the presence and absence of mulch in two different years. The experiment was carried out in two different seasons (2017 dry season and 2018 rainy season), in the vegetable garden of Liberdade campus, at the University of International Integration of Afro-Brazilian Lusophony (Unilab), municipality of Redenção-CE. The experimental design was in randomized blocks in a split-plot arrangement, with four repetitions, in which the plots consisted of growing with and without mulching and in the subplots, five shading screens: 50% Black Shading Screen (50% BSS), 50% Red Shading Screen (50% RSS), 30% White Shading Screen (30% WSS), 70% Black Shading Screen (70% BSS) ), and full sunlight (FS). The red shading screens 50% and white 30%, in addition to cultivation under full sunlight, provide higher performance in terms of the number of leaves, tuberous root diameter, tuberous root matter, and the radish crop productivity, regardless of the evaluated period. The applied mulch does not influence the productivity of the rabante, influencing only the gain of dry mass of the aerial part, soluble solids and length of the tuberous root
CARACTERIZAÇÃO GEOMORFOLÓGICA DOS MACROCOMPARTIMENTOS DE RELEVO NO NORDESTE SETENTRIONAL BRASILEIRO
A Geografia tem como objetivo entender as relações existentes no espaço geográfico, diante desse pressuposto entra a geomorfologia, que é o resultado dos processos da dinâmica física no espaço. Nesse sentido, buscou-se entender as dinâmicas ambientais na formação do relevo nordestino. Dessa forma, o artigo de por objetivos reconhecer as mudanças ambientas e caracterizar os macrocompartimentos do Nordeste setentrional. Na condução do estudo foram realizados levantamentos bibliográficos, documentais, cartográficos e trabalho de campo. Tendo como resultados a caracterização dos seguintes macrocompartimentos: Costa do Nordeste setentrional, Planície costeira, Tabuleiros costeiros, Depressão sertaneja setentrional, Planalto da Borborema, Chapada do Apodi e Chapada do Araripe. Foi possível observar que esses macrocompartimentos estão condicionados à diferentes dinâmicas e resultando diferentes feições
Biodiversity and community structure of zooplankton in the Sub-basin of Rio Poxim, Sergipe, Brazil
The zooplankton of aquatic environments is composed mostly of protozoans, rotifers, cladocerans and copepods, which play an important role in the food chain, transferring mass and energy from primary producers to higher trophic levels. This work was prepared with the objective of contributing to the knowledge of zooplankton biodiversity that occurs in the Sub-basin of Rio Poxim. Water samples were taken at monthly intervals at four sampling stations located along the sub-basin in the period August 2009 to July 2010. To obtain the zooplankton community, 100 L of water were filtered on nylon net with an aperture of 50 mm. Were identified 72 taxa distributed in the following taxonomic categories Rotifera, Protozoa, Porifera, Nematoda, Anellida, Cladocera, Copepoda, Ostracoda, Isopoda and Insecta. In terms of species richness, the phylum Rotifera followed by the Protoctista were the most relevant with forty and fifteen taxa, respectively. The most representative taxa in numerical terms were Arcella vulgaris, Notholca sp. Rotary sp. and nematodes. Regarding the community diversity index, the community was characterized as low diversity, but the taxa were distributed evenly in all monitoring points
Subclavian Access for Transcatheter CoreValve® Aortic Prosthesis Implantation: Data from the Brazilian Registry
ABSTRACTBackgroundTransfemoral access is the preferred approach for transcatheter aortic valve implantation. However, some situations, such as the presence of peripheral vascular disease, preclude the use of such access. In these cases, subclavian access is an alternative approach for this procedure. This study aimed at evaluating the Brazilian experience using the subclavian approach for transcatheter CoreValve® prosthesis implantation.MethodsAortic valve area<1cm2, aortic valve ring≥20mm and≤27mm (26mm and 29mm CoreValve®), ascending aorta≤43mm and subclavian artery with a diameter≥6mm, without significant obstructive lesions, marked tortuosity and excess calcification were requisites for the procedure. The access through the subclavian artery was obtained by surgical dissection and, under direct vision, a subclavian artery puncture was performed. Once artery access was obtained, the standard technique was used.ResultsBetween January 2008 and April 2012, 8 patients with peripheral vascular disease underwent CoreValve® prosthesis implantation through the subclavian artery in 4 institutions. The procedure was successful in all cases with reduction of the mean transvalvular pressure gradient from 46.4±17.5mmHg to 9.3±3.6mmHg (P=0.0018) and improvement of symptoms. At 30 days and after 275±231 days of follow-up, 87.5% and 62.5% of the patients, respectively, were free from major adverse events (death, myocardial infarction, stroke and urgent cardiac suregery).ConclusionsIn the Brazilian experience, the subclavian access was a safe and effective alternative for transcatheter CoreValve® implantation
Estudo da diversidade da comunidade tecamebiana (protozoa: rhizopoda) na sub-bacia hidrográfica do Rio Poxim-SE
Dos protozoários que constituem o zooplâncton, ressalta-se o grupo das amebas testáceas (Protoctista:Rhizopoda), protozoários amebóides, cujo citoplasma está encerrado dentro de uma concha ou teca. Estas são abundantes na maioria dos ecossistemas aquáticos e terrestres, apresentado uma grande produção de biomassa e uma importante contribuição no fluxo de energia e na ciclagem de nutrientes através do consumo direto de outros microorganismos e dos detritos. Diante da contribuição do grupo para os ambientes lênticos e lóticos, o presente estudo objetivou conhecer a biodiversidade das tecamebas que ocorrem na sub-bacia hidrográfica do Rio Poxim-SE. Para obtenção do material biológico foram demarcadas quatro estações distintas. As coletas foram efetuadas mensalmente de agosto a dezembro de 2009. O material biológico foi obtido através da filtração de 100 L da água local, através de uma tela de nylon com 50 m de abertura de malhas. Em campo, o material coletado foi fixado em solução 6.3.1 (60% de água destilada, 30% de álcool e 10% de formaldeído) e em laboratório, examinado sob microscópio óptico e contado em uma lâmina do tipo Sedgwick-Rafter. A comunidade tecamebiana esteve constituída por 8 táxons, distribuídos nas seguintes famílias: Arcellidae, Difflugidae, Centropyxidae e Trinematiidae. As duas primeiras famílias se apresentaram com maior riqueza de táxons e apenas uma espécie foi enquadrada na categoria de muito freqüente a Arcella vulgaris, sendo que a mesma se apresentou dominante na Estação 1, abundante nas Estações 2 e 4; na Estação 3, pouco abundante.
_________________________________________________________________________________________ ABSTRACT: Of protozoa which constitute the zooplankton, it em
phasizes the group of testate amoebae (Protoctista:
Rhizopoda), amoeboid protozoa, whose cytoplasm is e
nclosed within a shell or teak.
These are abundant
in most aquatic and terrestrial ecosystems, present
ed a large biomass production and an important
contribution in the energy flow and nutrient cyclin
g through the direct consumption of other
microorganisms and debris. Given the contribution o
f the group for the lentic and lotic environments,
this
study investigated the biodiversity of testate amoe
bae occurring in sub-basin of Rio Poxim-SE. For
obtaining biological material were demarcated four
distinct seasons. The samples were taken monthly
from August to December 2009. The biological materi
al was obtained by filtration of 100 L of the local
water through a nylon net with 50 μ m aperture mesh.
In the field, the material collected was fixed in
6.3.1
solution (60% distilled water, 30% alcohol and 10%
formaldehyde) and in laboratory and examined under
light microscope and counted in a blade-type Sedgwi
ck-Rafter. The community was made up of nine
tecamebiana taxa, distributed in the following fami
lies: Arcellidae, Difflugidae, Centropyxidae and
Trinematiidae. The first two families are presented
with more taxa and only one species was framed in
the
category of very frequent
Arcella vulgaris
, and the same appeared dominan in station 1, abund
ant in
stations 2 and 4, in season 3, slightly abundant
Avaliação da inserção de radiopacificadores na medicação intracanal em diferentes proporções associados ao Hidróxido de Cálcio: Evaluation of the insertion of radiopacificators in intracannel medication in different proportions associated with Calcium Hydroxide
A medicação intracanal contribui para o sucesso do tratamento endodôntico, sendo a radiopacidade uma propriedade física requerida. Um agente radiopacificante deve ser adicionado ao cimento ou medicação para permitir que a qualidade da obturação do canal ou escoamento da substância seja visualizado radiograficamente. Objetivo: Avaliar a inserção de óxido de zinco, óxido de zircônio e iodofórmio como radiopacificadores na medicação intracanal em diferentes proporções, associados ao hidróxido de cálcio. Estudo laboratorial, intervencional, longitudinal de caráter quantitativo. Para os testes de radiopacidade foram adicionados hidróxido de cálcio, óxido de zircônio, óxido de zinco e iodofórmio como radiopacificadores em percentual de 20%,30%, 40%, 50% e 60%; conforme ISO 6876/2012. O mesmo parâmetro foi utilizado para determinar a radiopacidade. As pastas manipuladas foram inseridas em anéis metálicos, medindo 10,0 mm de diâmetro interno e 1,0 mm de altura (n = 3). Os espécimes ficaram apoiados sobre película oclusal com penetrômetro de alumínio. Os filmes foram sensibilizados com aparelho de raios-X e analisados pelo programa Photopea, que determinou o valor de radiopacidade de acordo com a densidade radiográfica, convertida em milímetros de alumínio (mm Al). O Iodofórmio mostrou melhor percentual em 40%, óxido de zircônia em 30%, não havendo diferença estatística em nenhuma proporção do óxido de zinco, sendo este o único grupo que não apresentou diferença para o grupo controle na comparação entre todos materiais. Na endodontia, a desinfecção é fator importante. Em alguns casos, é indicada uma medicação que possua valores radiográficos suficientes para a visualização do composto dentro do canal
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