2,084 research outputs found
A cytoplasmic Slo3 isoform is expressed in somatic tissues
Slo3 is a pH-sensitive and weakly voltage-sensitive potassium channel that is essential for male fertility in mouse and whose expression is regarded as sperm-specific. These properties have proposed Slo3 as a candidate target for male contraceptive drugs. Nonetheless, the tissue distribution of Slo3 expression has not been rigorously studied yet. Applying computational and RT-PCR approaches, we identified expression of two short Slo3 isoforms in somatic mouse tissues such as brain, kidney and eye. These isoforms, which seem to result of transcription starting sites between exons 20 and 21, have an identical open reading frame, both encoding the terminal 381 amino acids of the cytosolic Slo3 domain. We corroborated the expression of these isoforms in mouse brain and testis by Western-blot. The complete isoform encoding the Slo3 ion channel was uniquely detected in testis, both at transcript and protein level. Although the functional role of the cytosolic Slo3 isoforms remains to be established, we propose that they may have a functional effect by modulating Slo channels trafficking and/or activity. This study confirms that expression of full-length Slo3 is sperm-specific but warns against developing contraceptive drugs targeting the C-terminal tail of Slo3 channels
ANTIMYCOBACTERIAL AND CYTOTOXICITY ACTIVITIES OF FREE AND LIPOSOME-ENCAPSULATED 3-(4 '-BROMO[1,1 '-BIPHENYL-4-YL)-3-(4-BROMO-PHENYL)-N,N-DIMETHYL-2-PROPEN-1-AMINE
Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)The antimycobacterial activity of 3-(4'-bromo[1,1'-bipheny1-4-yl)-3-(4-bromo-phenyl-N,N-dimethyl-2-propen-1-amine (BBAP), free or incorporated in preformed liposomes, on extracellular M. tuberculosis H37Rv was 8 and 25 mu M (MIC), respectively. Extracellular antimycobacterial activity was not significantly improved by entrapment of BBAP in liposomes, but there was a 6.1-fold reduction of BBAP cytotoxicity on J774 macrophages. Liposomal BBAP or its free form showed IC(50) values of 165 and 27 mu M, resulting in a selectivity index (SI=IC(50)/MIC) of 3.4 and 6.6, respectively. Free BBAP in concentrations from 10 to 80 mu M were quite effective in eliminating intracellular M. tuberculosis while liposomal formulation was less effective at these concentrations.334871874Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq
Fracturing ranked surfaces
Discretized landscapes can be mapped onto ranked surfaces, where every
element (site or bond) has a unique rank associated with its corresponding
relative height. By sequentially allocating these elements according to their
ranks and systematically preventing the occupation of bridges, namely elements
that, if occupied, would provide global connectivity, we disclose that bridges
hide a new tricritical point at an occupation fraction , where
is the percolation threshold of random percolation. For any value of in the
interval , our results show that the set of bridges has a
fractal dimension in two dimensions. In the limit , a self-similar fracture is revealed as a singly connected line
that divides the system in two domains. We then unveil how several seemingly
unrelated physical models tumble into the same universality class and also
present results for higher dimensions
Synthesis of hydrogels of cellulose acetate (AC) cross-linked with 3,3?,4,4? benzophenonetetracarboxylic dianhydride (BTDA) : characterization and adsorption physicochemical study.
Este trabalho descreve as s?nteses de hidrog?is superabsorventes a base de acetato de celulose (AC), com grau de substitui??o 2.5, reticulado com dianidrido 3, 3?, 4, 4? benzofenona tetracarbox?lico (BTDA). As caracteriza??es das mat?rias primas foram realizadas por an?lises t?rmicas (TG/DTG) e espectroscopia na regi?o do infravermelho (FTIR). O grau de substitui??o do acetato de celulose foi determinado por via ?mida. A confirma??o da rea??o de esterifica??o foi poss?vel a partir da t?cnica de FTIR, espectroscopia UV-vis e an?lises t?rmicas (TG/DTG). A presen?a de poros no novo material foi analisada por microscopia eletr?nica de varredura (MEV) e porosimetria (BET). A influ?ncia da concentra??o de dianidrido no meio reacional foi investigada, bem como a influ?ncia do aumento no grau de reticula??o no comportamento t?rmico do material. Foram obtidas isotermas de absor??o de ?gua em diferentes temperaturas para os hidrog?is com diferentes graus de reticula??o. Os coeficientes de difus?o dos g?is foram determinados, juntamente com a energia de ativa??o para o processo de inchamento usando a equa??o de Arrhenius. A entalpia de mistura do sistema gel-?gua foi determinada pela medida da quantidade m?xima de ?gua absorvida no equil?brio a diferentes temperaturas, empregando a equa??o de Gibbs/Helmholtz.This work describes the synthesis of hydrogels of cellulose acetate (AC), with a nominal degree of substitution DS = 2.5, cross-linked with 3,3?,4,4? benzophenonetetracarboxylic dianhydride (BTDA). The raw materials were characterized by thermal analysis (TG/DTG) and by Fourier transform infrared spectroscopy (FTIR). DS of cellulose acetate was determined by titration with a known amount of standard NaOH solution. Hydrogels of BTDA were synthesized with 0.5, 0.75 and 1.0 mol of BTDA/mol of AC. FTIR proved to be a suitable method to monitor the course of reactions and the progress of purification. UV-vis spectroscopy and analysis confirmed the esterification of the free hydroxyl groups. Surface modification of AC structure after the cross-linking reaction was analyzed by Scanning Electron Microscope (SEM) and density and porosity of the hydrogels were determined by BET. The influence of the concentration of dianhydride on the time necessary for formation of the gel was investigated. The influence from the increase in the degree of cross-linking on the thermal behavior of the material was also documented. Water absorption isotherms were obtained for hydrogels with different reticulating agents and reticulation degrees at different temperatures. The Arrhenius equation was used to determine the diffusion coefficient of the different hydrogels at distinct temperatures and the threshold energy for the swelling process. The enthalpy of mixture was determined through the measurement of the maximum quantity of water absorbed at equilibrium at different temperatures, with the Gibbs/Helmholtz equation
Pneumonia and poverty: a prospective population-based study among children in Brazil
<p>Abstract</p> <p>Background</p> <p>Children in developing country suffer the highest burden of pneumonia. However, few studies have evaluated associations between poverty and pneumonia.</p> <p>Methods</p> <p>A prospective population-based study on pneumonia was carried out as part of the Latin America Epidemiological Assessment of Pneumococcus (LEAP study). Chest x-rays were obtained for children one to 35 months old with suspected pneumonia presenting to emergency care centers and hospital emergency rooms in Goiania, Brazil. Chest radiographs were evaluated according to WHO guidelines. Clustering of radiologically-confirmed pneumonia were evaluated using a Poisson-based spatial scan statistic. Associations between census socioeconomic indicators and pneumonia incidence rates were analyzed using generalized linear models.</p> <p>Results</p> <p>From May, 2007 to May, 2009, chest radiographs were obtained from 11 521 children with clinical pneumonia; 3955 episodes were classified as radiologically-confirmed. Incidence rates were significantly higher in very low income areas (4825.2 per 10<sup>5</sup>) compared to high income areas (1637.3 per 10<sup>5</sup>). Spatial analysis identified clustering of confirmed pneumonia in Western (RR 1.78; p = 0.001) and Southeast (RR 1.46; p = 0.001) regions of the city, and clustering of hospitalized pneumonia in the Western region (RR 1.69; p = 0.001). Lower income households and illiteracy were associated with pneumonia incidence.</p> <p>Conclusions</p> <p>In infants the risk of developing pneumonia is inversely associated with the head of household income and with the woman educational level. Areas with deprived socioeconomic conditions had higher incidence of pneumonia and should be targeted for high vaccination coverage.</p
COMPARATIVE VOLUME EQUATIONS ADJUSTED WITH DATA OF STEM MEASUREMENTS AND STEM ANALYSIS
Este trabalho teve como objetivo comparar estimativas de volume com
casca, obtidas com equa\ue7\uf5es originadas partindo de dados da
cubagem com casca e an\ue1lise de tronco sem casca respectivamente. A
base de informa\ue7\uf5es para o desenvolvimento deste estudo foi
obtida em povoamentos de Pinus taeda L. no munic\uedpio de Ponte
Alta do Norte, Santa Catarina, sendo composta de duzentos e quarenta
\ue1rvores cubadas com casca em diferentes idades, as quais foram
selecionadas aleatoriamente e distribu\ueddas por classe de
di\ue2metro. Outra fonte de dados foi obtida com a an\ue1lise de
tronco sem casca de trinta \ue1rvores-amostra, distribu\ueddas
entre m\ue9dias e dominantes. Foram testados modelos matem\ue1ticos
para cada fonte de dados, afim de selecionar o de melhor ajuste e
precis\ue3o, com base no crit\ue9rio de sele\ue7\ue3o do Valor
Ponderado dos Escores dos Par\ue2metros Estat\uedsticos (VP). O
resultado do VP revelou a equa\ue7\ue3o de Schumacher-Hall como
mais adequada na estimativa do volume para as respectivas fontes de
dados. A compara\ue7\ue3o entre as estimativas de volume dos
modelos ajustados, partindo de dados da cubagem com casca e da
an\ue1lise de tronco sem casca, foi realizada com o teste
Qui-quadrado, que demonstrou n\ue3o haver diferen\ue7a
significativa entre elas, permitindo afirmar que \ue9 poss\uedvel
obter o volume com casca com base em uma equa\ue7\ue3o gerada com
dados de volume sem casca, obtidos pela an\ue1lise de tronco.This work aimed at comparing volume estimates with bark, obtained with
equations originated from data of the stem measurements with bark and
stem analysis without bark, respectively. The base of information for
the development of this study was obtained in forest of Pinus taeda
L. in the municipal district of Ponte Alta do Norte, Santa Catarina,
being composed by two hundred and forty trees measured with bark in
different ages, which were selected aleatorily and distributed by
diameter class. Another source of data was obtained with the stem
analysis without bark of thirty sample trees, distributed among
averages and dominant. Mathematical models were tested for each source
of data, in order to select the one of better adjustment and precision,
with base in the selection criterion of the Score Pondered Value of the
Statistical Parameters (VP). The result of VP revealed the equation of
Schumacher-Hall as the most appropriated one in the estimate of the
volume for the respective sources of data. The comparison between the
estimates of volume of the adjusted models starting from data of the
stem measurements with bark and of the stem analysis without bark was
accomplished with the test Qui-square, which demonstrated that there
area no significant differences to be significant difference among the
them allowing to affirm that it is possible to obtain the volume with
bark starting from an equation generated with volume data without bark,
obtained through the stem analysis
Mortalidade infantil e acesso geográfico ao parto nos municÃpios brasileiros
OBJETIVO: Analisar o acesso geográfico ao parto hospitalar nos municÃpios brasileiros. MÉTODOS: Foram analisadas informações de óbitos e nascimentos quanto à sua adequação para o cálculo do coeficiente de mortalidade infantil no perÃodo de 2005 a 2007 para os 5.564 municÃpios brasileiros. O acesso geográfico foi expresso por indicadores de deslocamento, oferta e acesso aos serviços de saúde. A associação entre o acesso geográfico ao parto e o coeficiente de mortalidade infantil em municÃpios com adequação de suas informações vitais foi avaliada por meio de regressão múltipla. RESULTADOS: Dentre os municÃpios analisados, 56% apresentaram adequação das informações vitais, correspondendo a 72% da população brasileira. O deslocamento geográfico ao parto mostrou-se inversamente associado ao porte populacional, à renda per capita, e à mortalidade infantil, mesmo controlado por fatores demográficos e socioeconômicos. CONCLUSÕES: Embora tenham sido desenvolvidas estratégias importantes para a melhoria da qualidade do atendimento à s gestantes no Brasil, as ações para garantir o acesso igualitário à assistência ao parto ainda são insuficientes. O maior deslocamento intermunicipal para o parto se mostrou como um fator de risco para a mortalidade infantil, aliado à desigualdade de oferta de serviços qualificados e à falta de integração com a atenção básica de saúde
ANNUAL INCREMENT VARIATION ALONG STEM OF Pinus taeda L. IN DIFFERENT AGES AND POPULATION DENSITIES
A varia\ue7\ue3o do crescimento anual em diferentes alturas do
fuste de Pinus taeda L. foi estudada por meio da an\ue1lise de tronco
em \ue1rvores do estrato dominante e m\ue9dio. Foram coletadas
sec\ue7\uf5es transversais ao longo do fuste de 9
\ue1rvores-amostra, tomadas na base, \ue0 altura do peito (DAP), e
ap\uf3s, a cada metro. A amostragem foi constitu\uedda de 4
\ue1rvores provenientes de Canela, Rio Grande do Sul, em floresta com
17 anos de idade, submetida a um desbaste, e 5 \ue1rvores de Ponte
Alta do Norte, Santa Catarina, em floresta com 34 anos, submetida a
cinco desbastes. Os resultados, expressos na forma percentual do
incremento em \ue1rea basal na posi\ue7\ue3o \u201ci\u201d,
sobre o incremento em \ue1rea basal ao n\uedvel do DAP, mostraram a
forte varia\ue7\ue3o na deposi\ue7\ue3o anual de lenho ao longo
do fuste em fun\ue7\ue3o da densidade populacional, caracterizando
os efeitos da competi\ue7\ue3o e da libera\ue7\ue3o pela
execu\ue7\ue3o do desbaste. \uc1rvores sujeitas \ue0
competi\ue7\ue3o mostraram maior crescimento nas partes superiores
do fuste, enquanto que \ue1rvores sob menor concorr\ueancia
apresentaram maior crescimento em posi\ue7\uf5es inferiores,
facilmente identificadas pela forma e inclina\ue7\ue3o das curvas
de incremento.The variation of the annual growth in different heights of the stem of
Pinus taeda L. was studied through the stem analysis, accomplished in
dominant and medium stratum trees. Cross sections were collected along
the stem from 9 sample trees on the base, breast height diameter (BHD)
and after these positions, at every meter. The sampling was constituted
of 4 trees coming from Canela, Rio Grande do Sul, in a 17-years-old
stand, submitted to one thinning, and 6 trees from Ponte Alta do Norte,
Santa Catarina, in a 34-years-old stand, submitted to five thinnings.
The results, expressed in percentage of the basal area increment in
several positions of the tree height, showed strong variation in the
annual deposition of wood along the stem in function of the
populational density, characterizing the effects of the competition and
of the thinning liberation. Trees subjected to the competition showed
larger growth on top parts of the stem, while trees under smaller
competition presented larger growth on lower positions, easily
identified by the form and inclination of the increment curves
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