Influence of crosslinkers and crosslinking method on the properties of gelatin films extracted from leather solid waste

Gelatin was extracted from chrome tanned leather waste with the aim to produce a durable coating or film. Crosslinking has shown to improve the physical performance of a film/coating. The effect of the method of crosslinking and the use of different crosslinking agents were studied. The extracted gelatin was crosslinked either by immersion of preformed films into a crosslinker solution (Method A) or by the addition of the crosslinking reagent to the gelatin solution prior to film formation (Method B). The different results obtained between both methods may be due to: the relative concentration of crosslinking reagent, the introduction of crosslinks within different regions of gelatin (triple helical regions and random coil regions), and the reaction rate. Method A of crosslinking is more likely to form crosslinks outside but close to the triple helical regions, disrupting the order and stability of the helical structure. Crosslinks may form preferentially within the random coil regions when Method B of crosslinking is used. Both methods led to the formation of chemical crosslinks in the extracted gelatin films, as demonstrated by the reduction of the degree of aqueous swelling and the proportion of low molecular weight fractions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Usefulness of bandage contact lenses in the immediate postoperative period after uneventful myopic LASIK

Purpose

To determine the usefulness of a silicone-hydrogel bandage contact lens (BCL) in the immediate postoperative period after uneventful myopic laser in-situ keratomileusis (LASIK).

Polyphenols and human health: a prospectus

The lay press often heralds polyphenols as panacea for all sorts of diseases. The rationale is that their antioxidant activity would prevent free radical damage to macromolecules. However, basic and clinical science is showing that the reality is much more complex than this and that several issues, notably content in foodstuff, bioavailability, or in vivo antioxidant activity are yet to be resolved. We summarize the recent findings concerning the effects of polyphenols on human health, analyze the current limitations at pitfalls, and propose future directions for research.     

What Lies Beneath: The Linguistic Traces of Deception in Online Dating Profiles

This article investigates whether deceptions in online dating profiles correlate with changes in the way daters write about themselves in the free‐text portion of the profile, and whether these changes are detectable by both computerized linguistic analyses and human judges. Computerized analyses (Study 1) found that deceptions manifested themselves through linguistic cues pertaining to (a) liars' emotions and cognitions and (b) liars' strategic efforts to manage their self‐presentations. Technological affordances (i.e., asynchronicity and editability) affected the production of cognitive cues more than that of emotional cues. Human judges (Study 2) relied on different and nonpredictive linguistic cues to assess daters' trustworthiness. The findings inform theories concerned with deception, media, and self‐presentation, and also expound on how writing style influences perceived trustworthiness.     

Flow distribution analysis by helical scanning in polysulfone hemodialyzers: effects of fiber structure and design on flow patterns and solute clearances

The efficiency of a hemodialyzer is largely dependent on its ability to facilitate diffusion, as this is the main mechanism by which small solutes are removed. The diffusion process can be impaired if there is a mismatch between blood and dialysate flow distribution in the dialyzer. The objective of the paper was to study the impact of different fiber bundle configurations on blood and dialysate flow distribution and urea clearances. The Optiflux 200 NR hemodialyzer was studied and the standard F 80 A hemodialyzer was used as a control for the study. Six dialyzers of each type were studied in vitro in the radiology department utilizing a new generation of helical computed tomography (CT) scan following contrast medium injection into the blood and dialysate compartment. Dynamic sequential imaging of longitudinal sections of the dialyzer was undertaken to detect flow distribution, average and peak velocities, and calculate wall shear rates. Six patients were dialyzed with 2 different dialyzers in random consecutive sequence. In these patients, 2 consecutive dialyses were carried out with identical operational parameters (Qb = 300 mL/min, Qd = 500 mL/min). In each session, blood and dialysate side urea clearances were measured at 30 and 150 min of treatment. Macroscopic and densitometrical analysis revealed that flow distribution was most homogeneous in the dialyzer with a new bundle configuration. Significantly increased urea clearances (p < 0.001) were seen with the Optiflux dialyzer compared with the standard dialyzer. In conclusion, more homogeneous dialysate blood and dialysate flow distribution and improved small solute clearances can be achieved by modifying the configuration of the filter bundle. These effects are achieved probably as a result of reduced blood to dialysate mismatch with reduction of flow channeling. The used radiological technique allows detailed flow distribution analysis and has the potential for testing future modifications to dialyzer design.     

Impact of paint and wall-paper on mould growth on plasterboards and aluminum

Biocide-free and biocide-treated plasterboards as well as aluminum plate as a reference material normally considered as being insensitive to mould growth have been used as substrate to check the influence of different common wall coverings, i.e. paints and wall papers, on fungal growth. The results described in this paper show that any non-biodegradable material (such as aluminum) can become a substrate to fungal infestation once painted or wall paper applied, depending on the type of paint or wall paper used. Moreover, a biodegradable material treated with a biocide (biocide-treated plasterboard) offers partial resistance to fungal growth at a biodegradable surface covering.     

Quantitative determination of octylphenol, nonylphenol, alkylphenol ethoxylates and alcohol ethoxylates by pressurized liquid extraction and liquid chromatography-mass spectrometry in soils treated with sewage sludges

Surfactants have one of the highest production rates of all organic chemicals. Non-ionic surfactants, especially alkylphenol ethoxylates, received most attention as precursors of estrogenic metabolic products generated during wastewater treatment. Alkylphenols (octyl and nonylphenol), alkylphenol polyethoxylates (APEOs), and alcohol ethoxylates (AEOs) have been determined in a Mediterranean forest soil (Mediterranean Rendzic Leptosol) amended with sludges from six waste water treatment plants (WWTPs) located in the Valencian Community. These compounds were isolated from soil by pressurized liquid extraction (PLE) using a mixture acetone-hexane (50:50 v/v), the extracts were cleaned up by solid-phase extraction (SPE) with C(18), and determined by liquid chromatography atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) using analytical standards for quantification. The method enabled high-reliable identification by monitoring the corresponding ammonium adduct [M+NH(3)](+) for AEOs and APEOs, and the deprotonated molecule [M-H](-) for octyl and nonylphenol. Recoveries, determined spiking soil samples at different concentrations, ranged from 89 to 94%, with limits of quantification from 1 to 100 microg kg(-1). Data obtained from a soil sample mixed with biosolids in the laboratory showed that these compounds are present at concentrations ranging from 0.02 to 5 mg kg(-1). According to these concentrations, levels of possible risk can be concluded for the presence of non-ionic surfactants in soil. However, further assessment will be necessary to establish the relationship between exposure and effect findings.