Multifractal fluctuations in zebrafish (Danio rerio) polarization time series.

In this work, we study the polarization time series obtained from experimental observation of a group of zebrafish (Danio rerio) confined in a circular tank. The complex dynamics of the individual trajectory evolution lead to the appearance of multiple characteristic scales. Employing the Multifractal Detrended Fluctuation Analysis (MF-DFA), we found distinct behaviors according to the parameters used. The polarization time series are multifractal at low fish densities and their average scales with ρ - 1 / 4 . On the other hand, they tend to be monofractal, and their average scales with ρ - 1 / 2 for high fish densities. These two regimes overlap at critical density ρ c , suggesting the existence of a phase transition separating them. We also observed that for low densities, the polarization velocity shows a non-Gaussian behavior with heavy tails associated with long-range correlation and becomes Gaussian for high densities, presenting an uncorrelated regime.

Zebrafish (Danio rerio) larvae show behavioral and embryonic development defects when exposed to opioids at embryo stage.

Opioid abuse continues to plague society, and in recent years, there has been an epidemic, leading to increased addiction and death. It is poorly understood how prenatal opioid use affects the lives of children. The aim of this work was to evaluate the effect of early embryonic codeine or morphine exposure in zebrafish (Danio rerio), examining gastrulation progression (epiboly), teratogenic effects, mortality and locomotor behavior response to light/dark cycles. Zebrafish embryos were exposed to codeine or morphine (designated C or M) at 1, 5 or 10 mg/L (designated 01, 05 or 10, respectively) from 3 to 24 h postfertilization (hpf) or from 3 to 48 hpf (designated -24 or - 48 for 1 or 2 days of exposure, respectively). The C10-24, C01-48, C05-48 and C10-48 groups showed significantly smaller eyes than control larvae at 7 days postfertilization (dpf). Locomotor behavior of control larvae in light/dark cycles showed greater swimming time and distance in dark cycles. Two-day codeine exposure produced strong effects, showing no significant response due to light/dark cycles in distance moved. Morphine exposed groups showed similar effects as observed in 2-day codeine exposed groups, showing less large movement activity and also no significant difference between inactive duration in response to light/dark cycles. In conclusion, we observed low teratogenic effects and mortality effects. Animals exposed to high levels and higher exposure times of opioids were hypoactive, relative to controls, in the dark period. Future studies will be needed to understand the neural defects producing behavior changes.

Nanoencapsulation of quercetin and resveratrol into elastic liposomes.

Based on the fact that quercetin (QUE) and resveratrol (RES) induce a synergic inhibition of the adipogenesis and increase apoptosis in adipocytes, and that sodium deoxycholate (SDC) has necrotic effects, the nanoencapsulation of QUE and RES into SDC-elastic liposomes is proposed as a new approach for dissolving the subcutaneous fat. The concentration of constituents and the effect of the drug incorporation into cyclodextrin inclusion complexes on the stability of QUE/RES-loaded liposomes were studied. The best liposomal formulation reduced the use of phosphatidylcholine and cholesterol in 17.7% and 68.4%, respectively. Liposomes presented a mean diameter of 149nm with a polydispersion index of 0.3. The zeta potential of liposomes was slightly negative (-13.3mV) due to the presence of SDC in the phospholipid bilayer. Encapsulation efficiency of QUE and RES into liposomes was almost 97%. To summarize, QUE/RES-loaded elastic liposomes are stable and suitable for subcutaneous injection, thereby providing a new strategy for reducing subcutaneous fat.

Physical-chemical parameters and validation of a colorimetric method for deoxycholic and ursodeoxycholic acids: kit reagent and optical sensor.

The simple and low cost ß-cyclodextrin (ß-CD)-phenolphthalein (PHP) inclusion complex was used for both the study of physical-chemical parameters and validation of analytical procedures for deoxycholic acid (DCA) and ursodeoxycholic acid (UDCA) determinations in different formulations. The usefulness of this inclusion complex is proposed either in the form of kit reagent and as an original optical sensor for DCA and UDCA. The results showed that temperature had a negative effect on the equilibrium constant resulting in high negative values of enthalpy and positive values of entropy. The half-life values for DCA and UDCA measurements were 68.71 and 294.71 days, respectively. The method was validated showing limits of detection and quantification of 4.92×10(-5) mol L(-1) and 1.64×10(-4) mol L(-1) for DCA, 1.14×10(-5) mol L(-1) and 3.79×10(-5) mol L(-1) for UDCA, respectively. The developed optical sensor also showed response linearity, ease of implementation and potential application in fast screening tasks even out of the laboratory.

Kinetics and bioreactor studies of immobilized invertase on polyurethane rigid adhesive foam.

A new support, polyurethane rigid adhesive foam (PRAF), which can be used to cover internal surface of metallic tubes, was used to immobilize invertase for application in an enzymatic bioreactor. The kinetic parameters were: Km--46.5±1.9 mM (PRAF-invertase) and 61.2±0.1 mM (free enzyme) and Vmax 42.0±4.3 U/mg protein/min (PRAF-invertase) and 445.3±24.0 U/mg protein/min (free invertase). The PRAF-invertase derivative maintained 50.1% of initial activity (69.17 U/g support) for 8 months (4°C) and was not observed microbial contamination. The bioreactor showed the best production of inverted sugar syrup using up-flow rate (0.48 L/h) with average conversion of 10.64±1.5% h(-1) at feeding rate (D) of 104 h(-1). The operational inactivation rate constant (kopi) and half-life were 1.92×10(-4) min(-1) and 60 h (continue use). The PRAF spray support looks promising as a new alternative to produce immobilized derivatives on reactor surfaces.

Simple determination of deoxycholic and ursodeoxycholic acids by phenolphthalein-beta-cyclodextrin inclusion complex.

An expeditious colorimetric methodology for the determination of the deoxycholic acid (DCA) and of the ursodeoxycholic acid (UDCA) in pharmaceutical formulations is reported. The method is based on their competitive complexation reaction with a color indicator to form beta-cyclodextrin-inclusion complexes. Several pH color indicators were tested, but phenolphthalein (PHP) showed the best interaction with the beta-cyclodextrin (beta-CD) with an inclusion yield higher than 95%. The best concentrations of beta-cyclodextrin to form inclusion complexes were 1.24 x 10(-3) and 6.2 x 10(-4) M at pH 9.5 and 10.5. Statistical analysis of the results showed that the pH had a significant effect on the DCA determination and that high beta-CD-PHP inclusion complex concentrations had a significant negative effect on the UDCA determination (p < 0.05). The limit of detection and limit of quantification were 3.94 x 10(-5) and 1.31 x 10(-4) M for DCA (range: 6.1 x 10(-6)-3.13 x 10(-3) M), 4.08 x 10(-5) and 1.36 x 10(-4) M for UDCA (range: 6.05 x 10(-6)-3.88 x 10(-4) M). This simple and cheap method showed high stability and feasible instrumentation.