Morphology and viscoelastic properties of melt‐spun HDPE/hydrotalcite nanocomposite fibers

Viscoelastic properties of nanocomposite fibers of high density polyethylene (HDPE) and organically modified hydrotalcite were studied. Neat and nanofilled HDPE fibers (with nanofiller content between 0.5 and 3 wt%) were produced by melt spinning and hot‐drawing at different draw ratios up to 20. Effect of temperature on storage modulus, loss modulus, and creep compliance were compared. Rising nanofiller content and/or drawing ratio accounted for an increase in storage modulus in the glassy (i.e., below the γ transition at −100°C) as well as in the rubbery state of non‐crystalline regions. The α relaxation temperature read‐off for the maximum of the loss modulus peak ranged from 20 to 60°C being dependent on frequency, filler content and draw ratio. Sumita model was successfully applied to evaluate the effective volume fraction of the dispersed phase; maximum fraction of immobilized matrix was observed for the composite with 1 wt% of nanofiller. Creep behavior was evaluated by fitting experimental data with the Burgers model. The addition of a small amount of well‐dispersed hydrotalcite (0.5–1 wt%) had a beneficial effect on the creep resistance of drawn fibers at room temperature as well as at 70°C. TEM analysis evidenced a good dispersion of 0.5% nanofiller in as‐spun fibers and improved interfacial adhesion after drawing. The best mechanical properties were observed for the composition with 1 wt% of hydrotalcite, due to combined effects of nanofiller reinforcement and stiffening produced by hot drawing. POLYM. COMPOS., 288–298, 2016. © 2014 Society of Plastics Engineers     

Longitudinal associations of depressive symptoms and pain with quality of life in patients receiving chronic hemodialysis

Depressive symptoms and pain are common in patients on chronic hemodialysis (HD), yet their associations with quality of life (QOL) are not fully understood. We sought to characterize the longitudinal associations of these symptoms with QOL. As part of a trial comparing two symptom management strategies in patients receiving chronic HD, we assessed depressive symptoms using the Patient Health Questionnaire‐9 (PHQ‐9), and pain using the Short Form McGill Pain Questionnaire (SF‐MPQ) monthly over 24 months. We assessed health‐related QOL (HR‐QOL) quarterly using the Short Form 12 (SF‐12) and global QOL (G‐QOL) using a single‐item survey. We used random effects linear regression to analyze the independent associations of depressive symptoms and pain, scaled based on 5‐point increments in symptom scores, with HR‐QOL and G‐QOL. Overall, 286 patients completed 1417 PHQ‐9 and SF‐MPQ symptom assessments, 1361 SF‐12 assessments, and 1416 G‐QOL assessments. Depressive symptoms were independently and inversely associated with SF‐12 physical HR‐QOL scores (β = ?1.09; 95% confidence interval [CI]: ?1.69, ?0.50, P < 0.001); SF‐12 mental HR‐QOL scores (β = ?4.52; 95% CI: ?5.15, ?3.89, P < 0.001); and G‐QOL scores (β = ?0.64; 95%CI: ?0.79, ?0.49, P < 0.001). Pain was independently and inversely associated with SF‐12 physical HR‐QOL scores (β = ?0.99; 95% CI: ?1.30, ?0.68, P < 0.001) and G‐QOL scores (β = ?0.12; 95%CI: ?0.20, ?0.05, P = 0.002); but not with SF‐12 mental HR‐QOL scores (β = ?0.16; 95%CI: ?0.050, 0.17, P = 0.34). In patients receiving chronic HD, depressive symptoms and to a lesser extent pain, are independently associated with reduced HR‐QOL and G‐QOL. Interventions to alleviate these symptoms could potentially improve patients' HR‐QOL and G‐QOL.     

Decontamination of seeds for seed sprout production by high hydrostatic pressure

Garden cress, sesame, radish, and mustard seeds immersed in water were treated with high pressure (250, 300, 350, and 400 MPa) for 15 min at 20 degrees C. After treatment, percentages of seeds germinating on water agar were recorded for up to 11 days. Of the seeds tested, radish seeds were found to be the most pressure sensitive, with seeds treated at 250 MPa reaching 100% germination 9 days later than untreated control seeds did. Garden cress seeds, on the other hand, were the most pressure resistant, with seeds treated at 250 MPa reaching 100% germination 1 day later than untreated control seeds did. Garden cress sprouts from seeds treated at 250 and 300 MPa also took about 1 day longer to reach average sprout length than sprouts from untreated control seeds did, indicating that sprout growth was not retarded once germination had occurred. Garden cress seeds were inoculated with suspensions of seven different bacteria (10(7) CFU/ml) and processed with high pressure. Treatment at 300 MPa (15 min, 20 degrees C) resulted in 6-log reductions of Salmonella Typhimurium, Escherichia coli MG1655, and Listeria innocua, > 4-log reductions of Shigella flexneri and pressure-resistant E. coli LMM1010, and a 2-log reduction of Staphylococcus aureus. Enterococcus faecalis was virtually not inactivated. For suspensions of the gram-positive bacteria, similar levels of inactivation in water in the absence of garden cress seeds were found, but the inactivation of E. coil LMM1010 and S. flexneri in water in the absence of garden cress seeds was significantly less extensive. These data suggest that garden cress seeds contain a component that acts synergistically with high hydrostatic pressure against gram-negative bacteria.     

Field demonstration of successful bioaugmentation to achieve dechlorination of tetrachloroethene to ethene

A laboratory microcosm study and a pilot scale field test were conducted to evaluate biostimulation and bioaugmentation to dechlorinate tetrachloroethene (PCE) to ethene at Kelly Air Force Base. The site groundwater contained about 1 mg/L of PCE and lower amounts of trichloroethene (TCE) and cis-1,2-dichloroethene (cDCE). Laboratory microcosms inoculated with soil and groundwater from the site exhibited partial dechlorination of TCE to cDCE when amended with lactate or methanol. Following the addition of a dechlorinating enrichment culture, KB-1, the chlorinated ethenes in the microcosms were completely converted to ethene. The KB-1 culture is a natural dechlorinating microbial consortium that contains phylogenetic relatives of Dehalococcoides ethenogenes. The ability of KB-1 to stimulate biodegradation of chlorinated ethenes in situ was explored using a closed loop recirculation cell with a pore volume of approximately 64,000 L The pilot test area (PTA) groundwater was first amended with methanol and acetate to establish reducing conditions. Under these conditions, dechlorination of PCE to cDCE was observed. Thirteen liters of the KB-1 culture were then injected into the subsurface. Within 200 days, the concentrations of PCE, TCE, and cis-1,2-DCE within the PTA were all below 5 microg/L, and ethene production accounted for the observed mass loss. The maximum rates of dechlorination estimated from field date were rapid (half-lives of a few hours). Throughout the pilot test period, groundwater samples were assayed for the presence of Dehalococcoides using both a Dehalococcoides-specific PCR assay and 16S rDNA sequence information. The sequences detected in the PTA after bioaugmentation were specific to the Dehalococcoides species in the KB-1 culture. These sequences were observed to progressively increase in abundance and spread downgradient within the PTA. These results confirm that organisms in the KB-1 culture populated the PTA aquifer and contributed to the stimulation of dechlorination beyond cDCE to ethene.     

Angiotensin converting enzyme inhibition of fish protein hydrolysates prepared from alkaline‐aided channel catfish protein isolate

Peptides derived from aquatic animals have been shown to have inhibitory activity against angiotensin converting enzyme (ACE), which is a key enzyme behind elevated blood pressure. In this study a catfish protein isolate was prepared and hydrolyzed to 5%, 15% and 30% degrees of hydrolysis (% DH) and soluble peptides separated from the total hydrolysate. The hydrolysate and its soluble peptide fraction were studied separately. Increased hydrolysis produced smaller peptides, with the smallest peptides remaining in the soluble fraction. Both hydrolysates and its soluble fraction had high ACE inhibition activities, from 70% to 90.6%, depending on fraction and % DH. Results suggested that there is not a simple relationship between average peptide size and extent of % DH and ACE inactivation, but clearly the soluble fraction of the hydrolysate, containing the smallest peptides, is responsible for most of the ACE inhibition activity of the hydrolysate. Hydrolysates prepared from a pure and uniform catfish protein isolate substrate do therefore show a potential for ACE inhibition and may find use as bioactive ingredients. Copyright © 2007 Society of Chemical Industry     

Task-specific ionic liquids incorporating novel cations for the coordination and extraction of Hg2+ and Cd2+: synthesis,characterization, and extraction studies

A series of hydrophobic task-specific ionic liquids designed to extract Hg2+ and Cd2+ from water were prepared by appending urea-, thiourea-, and thioether-substituted alkyl groups to imidazoles and combining the resulting cationic species with PF6-. The new ionic liquids were characterized and investigated for their metal ion extraction capabilities. When used in liquid/liquid extraction of Hg2+ and Cd2+ from aqueous solutions, the metal ion distribution ratios increased several orders of magnitude, regardless of whether the ionic liquids were used as the sole extracting phase or doped into a series of [1-alkyl-3-methylimidazolium][PF6] (alkyl = n-C4-C8) ionic liquids to form a 1:1 solution. In the 1:1 mixtures, as the length of the alkyl chain increased from butyl to hexyl to octyl, the metal ion distribution ratios increased. Increasing the ratio TSIL/[C4mim][PF6] resulted in higher distribution ratios for both Hg2+ and Cd2+. Overall, the thiourea- and urea-derivatized cations yielded the highest distribution ratios, and those for Hg2+ were higher than those for Cd2+; however, a change in aqueous-phase pH does not promote the stripping of metal ions from the extracting phase. The combination of these imidazolium cations and PF6- produced ionic liquids with decreased thermal stability in comparison to [C(n)mim]-[PF6]. Gaussian98 restricted Hartree-Fock geometry optimizations for one of the thiourea-appended cations shows the charge delocalization around the ring and suggests that the thiourea group may aid in deprotonating the imidazolium ring and may be responsible for the lowered thermal stability of these cations.     

The Effect of Endogenous Pectinases on the Consistency of Tomato–Carrot Purée Mixes

Tomato and carrot were subjected to a split-stream process designed to produce a tomato–carrot suspension with reduced consistency. Raw tomatoes, containing pectinmethylesterase and endo-polygalacturonase, were mixed with thermally pretreated (blanched versus cooked) carrots containing different levels of solubilized pectin. After mixing the vegetables, tomato pectinases were shown to act on both tomato and carrot pectin in case an incubation step at medium temperature level (30 min, 40 °C), to allow enzyme action, was performed. Carrot pectin, when present in a mix of tomato and blanched (5 min, 95 °C) carrot, was solubilized as well as depolymerized, whereas depolymerization of the thermo-solubilized carrot pectin by the tomato pectinases was observed in the tomato–carrot purée containing cooked (30 min, 95 °C) carrots. The final serum pectin properties were however similar for both purée types. Carrot contributed more to the consistency of the purée mix compared with tomato but by stimulating the action of the tomato pectinases at mild temperature (30 min, 40 °C), this contribution was lost which resulted in a consistency reduction of the purée mix. This purée liquefaction was larger for the tomato–carrot purée containing blanched instead of cooked carrots. Based on the results, it is suggested that the liquefying effect is related to solubilization and degradation of pectin that is counteracted by a reduction in particle size. The purée mix containing cooked carrot showed in this respect smaller particle sizes than the mix containing blanched carrot.     

Intestinal passage of microencapsulated fish oil in rats following oral administration

Fish oil labelled with [(14)C-linolenin] tracer was orally administered by gavage as an oil-water mixture (free oil) or as an oil-in-water emulsion formulation (microencapsulated oil) to fasted rats. Groups of rats were then given food after gavage or alternatively not fed to examine the effect of food on intestinal passage. Feeding after gavage drives lumenal free oil faster through the gastrointestinal (GI) tract. Microencapsulation slows down the lumenal progression in the GI tract with feeding. Non-feeding also slows down the lumenal progress of free oil in the GI tract but this is not influenced by microencapsulation. Analysis of the relative distribution of the label along the GI tract tissue wall showed that the upper small intestine was the main site of label accumulation in the GI tract. Of the oil that remained in the lumen, there was slight protection against early uptake and metabolism in the stomach and upper GI tract in rats that were either fed or not fed after dosing when microencapsulated oil was administered. Microencapsulation increased the levels of radiolabel in the liver and blood. The primary organ for accumulation of radiolabel for both free and microencapsulated oils in rats that were fed or fasted after dosing was the liver.     

Managing countertransference.

In this article, we review the history and definition of countertransference as well as empirical research on countertransference, its management, and the relation of both to psychotherapy outcome. Three meta-analyses are presented, as well as studies that illustrate findings from the meta-analyses. The first meta-analysis indicated that countertransference reactions are related inversely and modestly to psychotherapy outcomes (overall weighted effect r = ?.16, p = .002, 95% CI [?.26, ?.06], k = 10 studies, N = 769 participants). The second meta-analysis suggested that countertransference management factors that have been studied to date play little to no role in actually attenuating countertransference reactions (r = ?.14, p = .10, 95% CI [?.30, .03], k = 11 studies, N = 1065 participants). However, the final meta-analysis revealed that managing countertransference successfully is related to better therapy outcomes (r = .56, p = .000, 95% CI [.40, .73], k = 7 studies, N = 478 participants). We conclude by summarizing the limitations of the research base and highlighting the therapeutic practices predicated on research. (PsycINFO Database Record (c) 2011 APA, all rights reserved)