121 research outputs found
Orientation and solvatochromism of dyes in liquid crystals.
The orientation and solvatochromism of some dye molecules in a liquid crystal have been investigated. Interactions with the host and the structure of the dye molecule affect the macroscopic alignment of dichroic dye molecules in a liquid crystal: It was observed that some dye molecules show a large bathochromic shift of their absorption maxima in the liquid crystal host relative to the situation in isotropic solvents. It is suggested that this is due to the occurrence of a much weaker reaction field in the anisotropic, rigid host. These dye molecules show little or no apparent order in the anisotropic host despite the observation of a reduction in the electro optic switching time when the dye is present. The highest degree of macroscopic alignment was observed for a merocyanine compound, which showed the smallest solvatochromic shift in the liquid crystal host. These results are discussed in terms of the steric, dipolar and hydrogen bond interactions between the guest and the host
The cytotoxicity of 3-bromopyruvate in breast cancer cells depends on extracellular pH
Although the anti-cancer properties of 3BP have been described previously, its selectivity for cancer cells still needs to be explained. In the work reported here we characterized the kinetic parameters of radiolabelled [14C]-3BP uptake in three breast cancer cell lines that display different levels of resistance to 3BP: ZR-75-1 < MCF-7 < SK-BR-3. At pH 6.0 the affinity of cancer cells for 3BP transport, correlates with their sensitivity, a pattern that does not occur at pH 7.4. In the three cell lines, the uptake of 3BP is dependent on the proton motive force and is decreased by MCTs inhibitors. In the SK-BR-3 cell line, a sodium-dependent transport also occurs. Butyrate promotes the localization of MCT-1 at the plasma membrane and increases the level of MCT-4 expression, leading to a higher sensitivity for 3BP. Here, we demonstrate that this phenotype is accompanied by an increase in affinity for 3BP uptake. Our results confirm the role of MCTs, especially MCT-1 in 3BP uptake and the importance of CD147 glycosylation in this process. We find that the affinity for 3BP transport is higher when the extracellular milieu is acid. This is a typical phenotype of tumor microenvironment and explains the lack of secondary effects of 3BP already described in in vivo studies.FEDER (Fundo Europeu deDesenvolvimento
Regional), through POFC (Programa Operacional Factores de Competitividade) –
COMPETE, and by Portuguese National Funds from FCT (Fundac¸˜ao para a Ciˆencia e
Tecnologia) in the scope of the project PEst-OE/BIA/U14050/2014. JAS [grant number
SFRH/BD/76038/2011] received a fellowship from the Portuguese government from the
FCT through FSE (Fundo Social Europeu) and POPH (Programa Operacional Potencial
Humano)
Expression of glycolytic enzymes in ovarian cancers and evaluation of the glycolytic pathway as a strategy for ovarian cancer treatment
Table S2. Spearman correlation of the expression of four glycolytic enzymes in a cohort of 380 ovarian cancers. Spearman rho correlation values (top value) along with the respective adjusted P value (bottom value) of statistically significant correlations thresholded at FDR Pâ<â0.01 are summarised. (DOCX 21 kb
Ecological management system as a factor influencing egg yolk quality
Celem badań przeprowadzonych w Instytucie Zootechniki PIB była ocena jakości żółtek jaj konsumpcyjnych pochodzących
od krajowych kur stad zachowawczych, utrzymywanych zgodnie z wymogami rolnictwa ekologicznego. Materiał badawczy
stanowiły jaja pochodzące od kur czterech ras zachowawczych: sussex, rhode island red (RIR), żółtonóżka kuropatwiana i
zielononóżka kuropatwiana. Przeprowadzone badania wykazały, iż jaja niosek utrzymywanych systemem ekologicznym
charakteryzowały się żółtkami o cechach odpowiadających preferencjom konsumentów (intensywne i równomierne
wybarwienie, mniejszy udział tłuszczu – żółtonóżka kuropatwiana). Parametry te są ważnym czynnikiem kształtującym popyt
na jaja.The aim of the study conducted at the National Research Institute of Animal Production was to estimate the egg yolk quality
from domestic conservative flocks of hens kept in accordance with the requirements of ecological farming. The research
materials consisted of hen eggs from four conservative flocks: sussex, rhode island red (RIR), greenleg partridge, yellowleg
partridge. Studies have shown that the characteristic of egg yolk of the birds kept in ecological system meet the expectations
of consumers (intense and uniform colour, lower fat content - yellowleg partridge). These parameters are an important factor
affecting the supply of eggs
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