The Effect of High Fat Diet on Cerebrovascular Health and Pathology: A Species Comparative Review

In both humans and animal models, consumption of a high-saturated-fat diet has been linked to vascular dysfunction and cognitive impairments. Laboratory animals provide excellent models for more invasive high-fat-diet-related research. However, the physiological differences between humans and common animal models in terms of how they react metabolically to high-fat diets need to be considered. Here, we review the factors that may affect the translatability of mechanistic research in animal models, paying special attention to the effects of a high-fat diet on vascular outcomes. We draw attention to the dissociation between metabolic syndrome and dyslipidemia in rodents, unlike the state in humans, where the two commonly occur. We also discuss the differential vulnerability between species to the metabolic and vascular effects of macronutrients in the diet. Findings from animal studies are better interpreted as modeling specific aspects of dysfunction. We conclude that the differences between species provide an opportunity to explore why some species are protected from the detrimental aspects of high-fat-diet-induced dysfunction, and to translate these findings into benefits for human health.     

Robust partial least squares regression—part III,outlier analysis and application studies

This paper is the third part of the work on robust partial least squares (RPLS) regression. The paper focuses on implementation issues for outlier detection and diagnosis. Furthermore, the paper introduces a numerically more efficient algorithm for determining the Stahel–Donoho estimator (SDE). This has been identified as a potential drawback of the new proposed RPLS algorithm, detailed in Part II of this work. Finally, a total of three application studies are presented which involve data recorded from (i) a calibration experiment (similar number of variables/observations), (ii) a distillation process for purifying benzene (considerably more observations than variables) and (iii) an experiment of a multi‐component concentration determination using Raman spectroscopy (considerably more variables than observations). Copyright © 2008 John Wiley & Sons, Ltd.     

Topology-based signal separation

Traditional noise-filtering techniques are known to significantly alter features of chaotic data. In this paper, we present a noncausal topology-based filtering method for continuous-time dynamical systems that is effective in removing additive, uncorrelated noise from time-series data. Signal-to-noise ratios and Lyapunov exponent estimates are dramatically improved following the removal of the identified noisy points.     

Rigidity of polycarbonate in the presence of sulfur dioxide

A torsional pendulum method was used to study the transient effects of sulfur dioxide at pressures up to 700 torr on the rigidity of Bisphenol-A polycarbonate at 25°C. Incremental increases in pressure led to a decrease and then to an increase in rigidity. Removal of sulfur dioxide at the rigidity minimum led to a rapid recovery in rigidity, but after apparent equilibrium had been reached the rigidity was not fully reversible. These observations provide evidence that sorption of sulfur dioxide results in structural reorganization of the polymer. A qualitative discussion of the data is presented.     

Solid-state Photoinduced Polymerization of 3-Methoxy-4-benzyloxystyrene

Abstract

The photoinduced polymerization of 3-methoxy-4-benzyloxystyrene (MBS) in the solid state has been studied by infrared spectroscopy, liquid chromatography, and scavenging experiments. In the absence of added photoinitiator, polymerization rates were found to accelerate as polymerization progressed. Reaction products consisted of unreacted MBS, dimer, and high-molecular-weight polymer. The polymerization was shown to proceed by a free-radical mechanism.     

YOYO as a Dye to Track Penetration of LK15 DNA Complexes in Spheroids: Use and Limits

To elucidate the reasons underlying the poor penetration of non-viral vectors in tissues, relating transport properties to physico-chemical parameters of vectors may be crucial. These properties can be influenced by the presence of multiples labels that are used. Therefore utilizing a vector with minimum of labels preferably not more than one is important to studying penetration in tissues. The cell impermeant bisintercalating dye YOYO-1 was found suitable to both monitor the formation of complexes between DNA and an amphipathic peptide LK15 and, to track their penetration in HCT116 spheroids by confocal microscopy. The results revealed a limited decrease of fluorescence ascribed to the high affinity of YOYO-1 to bind DNA. The residual fluorescence of complexes can be exploited to monitor penetration into spheroids, after correction for YOYO-1 attenuation, and to revealing hyaluronidase-induced reduced binding. Hence high affinity dyes such as YOYO-1 with inefficiently quenched fluorescence may be important to establish a relation between novel medicines characteristics and penetration in tissues.     

Neuropeptide delivery to the brain: a von Willebrand factor signal peptide to direct neuropeptide secretion

Background  

Multiple neuropeptides, sometimes with opposing functions, can be produced from one precursor gene. To study the roles of the different neuropeptides encoded by one large precursor we developed a method to overexpress minigenes and establish local secretion.     

Directly Bound Deuterons Increase X-Nuclei Hyperpolarization using Dynamic Nuclear Polarization

Deuterated ¹³C sites in sugars (D-glucose and 2-deoxy-D-glucose) showed 6.3-to-17.5-fold higher solid-state dynamic nuclear polarization (DNP) levels than their respective protonated sites at 3.35T. This effect was found to be unrelated to the protonation of the bath. Deuterated ¹⁵N in sites bound to exchangeable protons ([¹⁵N₂]urea) showed a 1.3-fold higher polarization than their respective protonated sites at the same magnetic field. This relatively smaller effect was attributed to incomplete deuteration of the ¹⁵N sites due to the solvent mixture. For a ¹⁵N site that is not bound to protons or deuterons ([¹⁵N]nitrate), deuteration of the bath did not affect the polarization level. These findings suggest a phenomenon related to DNP of X-nuclei directly bound to deuteron(s) as opposed to proton(s). It appears that direct binding to deuterons increases the solid-state DNP polarization level of X-nuclei which are otherwise bound to protons.