Assessing the contact‐activation of coagulation during hemodialysis with three different polysulfone filters: A prospective randomized cross‐over trial

Introduction: During hemodialysis (HD) the interaction of the blood with the dialyzer triggers both an inflammatory reaction and an activation of the coagulation cascade. An accepted parameter to quantify the extent of coagulation activation during HD is not available. This study aims to evaluate its amplitude, comparing dialyzers made of different polysulfone polymers, by measuring D‐dimers in the filter‐rinsing fluids (Frf) and to test whether Frf D‐dimers are suitable candidate markers to assess contact coagulation activation during HD. Methods: In a prospective, cross‐over study 41 hemodialysis patients were randomly allocated to nine HD sessions with three types of polysulfone membranes: Filter A: Poliflux®RevaclearMAX; Filter B: Helixone®Fx80, Filter C: Polyflux®H210. Findings: A total of 117 HD sessions were studied. The mean (SD) filter (Frf) D‐dimers were 0.19 µg/L (0.56) for Filter A; 0.66 µg/L (2.81) for Filter B; 0.33 µg/L (1.13) for Filter C. Significant differences were found: A vs. B (P < 0.01), A vs. C (P = 0.01); B vs. C not significant. A large between‐patient variability of D‐dimer filter levels was found. D‐Dimers in blood showed a similar trend but differences were not significant. Discussion: The contact activation of coagulation during HD may also vary among filters made up with similar polysulfones. D‐dimer in the filter rinsing fluid but not in the blood can be considered a candidate marker for the evaluation of thrombogenicity during HD. Further studies are needed to elucidate the mechanism(s) and to confirm the usefulness of filter rinsing fluid D‐Dimers as a clotting activation marker during HD.     

Bionanocomposite Polylactic Acid/Organoclay Films: Functional Properties and Measurement of Total and Lactic Acid Specific Migration

The aim of the work was to manufacture, using a laboratory‐scale film production pilot plant, nanocomposite polylactic acid (PLA) films added with Cloisite 30B clay‐derived nanofiller having one nanometric dimension, and to characterize and to assess the migration of the obtained systems, in view of food packaging applications. The study demonstrated that it is possible to obtain nanocomposite PLA films with intercalated/exfoliated morphology of the dispersed layered nanofiller using conventional film production technologies. With increasing the silicate content in the film, the developed systems show a marked improvement of the mechanical performance, with a rise in the modulus and in the elongation at break with respect to the unfilled PLA, a significant lowering in the oxygen permeability and a slight increase in the surface wettability, without given significant alteration of film transparency and chromatic perception. Compared with the unfilled PLA, no significant changes can be observed about the migration behaviour of the nanocomposite PLA systems. In fact, both the overall migration and the specific migration, measured as lactic acid, remain always well below the applicable generic specific migration limit of 60 mg/kg food (10 mg/dm²) of the Regulation EU 10/2011. Copyright © 2013 John Wiley & Sons, Ltd.     

Assessment of refractive index gradients by standard rainbow thermometry

Up to now the application of rainbow thermometry has been limited to particle systems possessing a uniform refractive index. This is mostly due to the absence of an appropriate data inversion algorithm that takes into account the presence of a refractive index gradient. In this paper, for the first time to our knowledge, exploiting a generalization of the Airy theory, a data inversion algorithm for a single droplet, presenting a parabolic refractive index gradient, is proposed. This data inversion algorithm is used to compute the diameter and the refractive index at the core and at the surface of a simulated burning droplet. The results are compared to the analytical solutions showing a satisfactory agreement.     

Turning Donepezil into a Multi-Target-Directed Ligand through a Merging Strategy

Thanks to the widespread use and safety profile of donepezil ( 1 ) in the treatment of Alzheimer's disease (AD), one of the most widely adopted multi-target-directed ligand (MTDL) design strategies is to modify its molecular structure by linking a second fragment carrying an additional AD-relevant biological property. Herein, supported by a proposed combination therapy of 1 and the quinone drug idebenone, we rationally designed novel 1 -based MTDLs targeting Aβ and oxidative pathways. By exploiting a bioisosteric replacement of the indanone core of 1 with a 1,4-naphthoquinone, we ended up with a series of highly merged derivatives, in principle devoid of the “physicochemical challenge” typical of large hybrid-based MTDLs. A preliminary investigation of their multi-target profile identified 9 , which showed a potent and selective butyrylcholinesterase inhibitory activity, together with antioxidant and antiaggregating properties. In addition, it displayed a promising drug-like profile.     

Potentiometric titrations in a poly(dimethylsiloxane)-based microfluidic device

This paper describes a microfluidic device, fabricated in poly(dimethylsiloxane), that is used for potentiometric titrations. This system generates step gradients of redox potentials in a series of microchannels. These potentials are probed by microelectrodes that are integrated into the chip; the measured potentials were used to produce a titration curve from which the end point of a reaction was measured.     

Proteolytic patterns and plasmin activity in ewes' milk as affected by somatic cell count and stage of lactation

A total of 120 milk samples were collected from Comisana ewes throughout lactation. The ewes were ranked into two somatic cell count (SCC) categories: normal milk (N Milk) with SCC lower than 5.00x 10(5)/ml and high somatic cell milk (HSC Milk) with SCC higher than 1.00 x 10(6)/ml. Milk samples were analysed in triplicate for pH, fat and protein contents, renneting parameters, and plasmin and plasminogen activities. The peptide profile due to total proteolytic activity (endogenous and exogenous enzymes) on alpha- and beta-CNs were determined using urea-PAGE on sodium caseinate (pH 8.0 and pH 5.0) incubated at 37 degrees C for 4 d after sampling. The peptide profile due to non-plasmin enzyme activities at pH 5.0 was also determined using urea-PAGE. Plasmin activity was higher in the HSC milk than in the N milk throughout the study period. A decrease in plasmin activity was observed in the N milk during mid-lactation, which was probably related to decrease in pH, and in the HSC milk during late lactation, which may be ascribed to an enhanced influx of plasmin inhibitors from the blood stream. Proteolytic patterns in Comisana ewe milk were mainly affected by plasmin activity that increased with the SCC in milk. Also non-plasmin proteolytic activity was strongly enhanced by elevated SCC and resulted in a higher degradation of alpha-casein than of beta-casein. In general, plasmin activity did not increase with the advancement of lactation and exhibited a different trend in HSC and N milk, suggesting that physiological factors did not play a key role in regulating the plasminogen-plasmin system in ewes' milk. Plasmin activity, detected with the colorimetric assay was consistent with proteolytic activity on sodium caseinate shown in urea-PAGE electrophoregram.     

Different packaging strategies for fresh-cut 'barattiere' melon cultivar (cucumis melo L.)

Optimising packaging for minimally processed 'Barattiere' melon cultivar ( Cucumis melo L.) is addressed in this work. Melon slices were dipped in water solution containing ascorbic acid (1%) and calcium chloride (0.2%). Dipped and untreated fresh-cut produce was packaged in four different polymeric materials (two biodegradable films, a commercially available multilayer film (MLF) and polypropylene), before storing at 5 °C. During storage, headspace gas composition, microbial quality, pH and mass loss were monitored for a period of 2 weeks. Results suggest that film characteristics strongly influenced gas concentrations in the headspace, microbial growth and weight. Among the tested packaging materials, the MLF seemed to delay significantly the detrimental phenomena involved in quality acceptance, even if clearly anaerobic atmospheres were recorded. The biodegradable films, combined with a dipping pre-treatment, could represent a good compromise between film performance and environmental impact.