Effect of sexual maturation on thermal stability, viscoelastic properties, and texture of female rainbow trout, Oncorhynchus mykiss, fillets

The nutrient and energy demand of sexual maturation in many fish cultivars causes structural change to key contractile proteins and thereby, affects fillet firmness. Thermal denaturation and viscoelastic properties of white muscle from diploid (2N; fertile) and triploid (3N; sterile) female rainbow trout were investigated at 6 age endpoints from July 2008 through spawning in March 2009. Differential scanning calorimetry showed, in March, that the actin denaturation temperature (T(max,actin)) of 2N females was higher than that observed in 3N females (78.17 versus 77.27 °C). From 35 to 45 °C, viscoelastic measurement revealed that muscle from 2N females and younger fish (July, 16 mo) had greater elasticity (lower tan δ) than muscle from 3N females and older fish (November to March; 20 to 24 mo), respectively. The highest elastic response and the firmest fillets were observed in July. Raw fillets were softer (Allo-Kramer shear; P < 0.05) from September to January (288.77 g/g on average) than those collected in July (475.15 g/g) and March (366.79 g/g). Soft fillets became firmer after cooking except for January samples. Greater cook yield and softer fillets were observed in January compared to December. Lipid accumulation in 3N females may lubricate muscle fibers and protect them from losing functionality during the spawning season for animals on a high plane of nutrition. PRACTICAL APPLICATION: The relationship between fish maturation, measured as egg development, and chemical characteristics of fillets from fertile and sterile fish was evaluated. Thermal denaturation and viscoelastic characterization revealed changes in stability and gelling properties of muscle proteins that were related to changes in fillet texture.     

Sorghum distillers dried grain lipid extract increases cholesterol excretion and decreases plasma and liver cholesterol concentration in hamsters

Grain sorghum is a rich source of phytochemicals. In this study, male hamsters were fed AIN-93M diets supplemented with a hexane-extractable lipid fraction from sorghum distillers dried grains with solubles (DDGS). Diets contained 0.0%, 0.5%, 1.0%, and 5.0% (w/w) DDGS lipid extract. After 4 wk, the 5.0% DDGS lipids group had significantly lower plasma non-HDL cholesterol and liver esterified cholesterol concentration. Faecal neutral sterol (i.e., cholesterol) excretion was significantly higher in the 5.0% DDGS lipids group compared to the other treatments (66% higher compared to controls). Bile acid excretion was not affected by DDGS lipid intake. Faecal cholesterol excretion was negatively correlated with liver cholesterol concentration (r = ?0.97, P = 0.026), and liver cholesterol concentration was directly correlated with plasma total cholesterol concentration (r = 0.96, P = 0.041). Thus, lipid extract of sorghum DDGS exhibited cholesterol-lowering properties due, at least in part, to increased cholesterol excretion from the body and could provide health benefits when incorporated into human diets.     

Application of amaranth protein isolate and hydrolysate on a reduced salt fish restructured product: antioxidant properties,textural and microbiological effects

This work evaluates amaranth protein ingredients [isolate (I) and alcalase‐hydrolysate (H)] acting as antioxidants and binders in restructured fish products. Gel products were obtained after thermal treatment (40 °C, 30 min; 90 °C, 30 min) of different formulations from fish muscle pastes, where salt (2%) was partially or totally replaced by I or H. Antioxidant activity was assessed by conjugated dienes and thiobarbituric acid‐reactive substances (TBARs) measurements during the chilled storage. Textural properties, water‐holding capacity, colour and microbiological quality were evaluated. Reduced‐salt content products containing 2% w/w of I or H partially inhibited lipid oxidation especially at the level of the decomposition of hydroperoxides into secondary products, due to about 50% and 60% of inhibition of TBARs, respectively, was registered. Also, these products showed acceptable microbiological quality and technological characteristics with only minimal changes in properties as gel hardness and colour parameters compared with control products (2% w/w salt).     

Molecular forces involved in heat-induced pea protein gelation: Effects of various reagents on the rheological properties of salt-extracted pea protein gels

The molecular forces involved in the gelation of heat-induced pea protein gel were studied by monitoring changes in gelation properties in the presence of different chemicals. At 0.3 M concentration, sodium thiocyanate (NaSCN) and sodium chloride (NaCl) showed more chaotropic characteristic and enhanced the gel stiffness, whereas sodium sulfate (Na₂SO₄) and sodium acetate (CH₃COONa) stabilized protein structure as noted by increasing denaturation temperatures (T_d) resulting in reduced storage moduli (G′). To determine the involvement of non-covalent bonds in pea protein gelation, guanidine hydrochloride (GuHCl), propylene glycol (PG), and urea were employed. The significant decrease in G′ of pea protein gels with the addition of 3 M GuHCl and 5 M urea indicated that hydrophobic interactions and hydrogen bonds are probably involved in pea protein gel formation. The increase in G′ with increasing PG concentration (5–20%), demonstrated hydrogen bonds and electrostatic interaction involvement. No significant influence was observed on G′ with addition of different concentrations of β-mercaptoethanol (2-ME), low levels of dithiothreitol (DTT), and up to 25 mM N-ethylmaleimide (NEM), which indicated that disulfide bonds are not required for gel formation, but data at higher DTT and NEM concentrations and slow cooling rates showed a minor contribution by disulfide bonds. Reheating and recooling demonstrated that gel strengthening during the cooling phase was thermally reversible but not all the hydrogen bonds disrupted in the reheating stage were recovered when recooled.     

Daily Enteral DHA Supplementation Alleviates Deficiency in Premature Infants

Docosahexaenoic acid (DHA) is an essential fatty acid (FA) important for health and neurodevelopment. Premature infants are at risk of DHA deficiency and circulating levels directly correlate with health outcomes. Most supplementation strategies have focused on increasing DHA content in mother's milk or infant formula. However, extremely premature infants may not reach full feedings for weeks and commercially available parenteral lipid emulsions do not contain preformed DHA, so blood levels decline rapidly after birth. Our objective was to develop a DHA supplementation strategy to overcome these barriers. This double‐blind, randomized, controlled trial determined feasibility, tolerability and efficacy of daily enteral DHA supplementation (50 mg/day) in addition to standard nutrition for preterm infants (24–34 weeks gestational age) beginning in the first week of life. Blood FA levels were analyzed at baseline, full feedings and near discharge in DHA (n = 31) or placebo supplemented (n = 29) preterm infants. Term peers (n = 30) were analyzed for comparison. Preterm infants had lower baseline DHA levels (p < 0.0001). Those receiving DHA had a progressive increase in circulating DHA over time (from 3.33 to 4.09 wt% or 2.88 to 3.55 mol%, p < 0.0001) while placebo‐supplemented infants (receiving standard neonatal nutrition) had no increase over time (from 3.35 to 3.32 wt% or 2.91 to 2.87 mol%). Although levels increased with additional DHA supplementation, preterm infants still had lower blood DHA levels than term peers (4.97 wt% or 4.31 mol%) at discharge (p = 0.0002). No differences in adverse events were observed between the groups. Overall, daily enteral DHA supplementation is feasible and alleviates deficiency in premature infants.     

The Effects of Annealing After Equal Channel Angular Extrusion (ECAE) on Mechanical and Magnetic Properties of 49Fe-49Co-2V Alloy

Metallurgical and Materials Transactions A - Equal channel angular extrusion (ECAE) of 49Fe-49Co-2V, also known as Hiperco® 50A or Permendur-2V, greatly improves the strength and ductility of...     

Immunologic Effects of Stereotactic Body Radiotherapy in Dogs with Spontaneous Tumors and the Impact of Intratumoral OX40/TLR Agonist Immunotherapy

Stereotactic body radiotherapy (SBRT) is known to induce important immunologic changes within the tumor microenvironment (TME). However, little is known regarding the early immune responses within the TME in the first few weeks following SBRT. Therefore, we used the canine spontaneous tumor model to investigate TME responses to SBRT, and how local injection of immune modulatory antibodies to OX40 and TLR 3/9 agonists might modify those responses. Pet dogs with spontaneous cancers (melanoma, carcinoma, sarcoma, n = 6 per group) were randomized to treatment with either SBRT or SBRT combined with local immunotherapy. Serial tumor biopsies and serum samples were analyzed for immunologic responses. SBRT alone resulted at two weeks after treatment in increased tumor densities of CD3+ T cells, FoxP3+ Tregs, and CD204+ macrophages, and increased expression of genes associated with immunosuppression. The addition of OX40/TLR3/9 immunotherapy to SBRT resulted in local depletion of Tregs and tumor macrophages and reduced Treg-associated gene expression (FoxP3), suppressed macrophage-associated gene expression (IL-8), and suppressed exhausted T cell-associated gene expression (CTLA4). Increased concentrations of IL-7, IL-15, and IL-18 were observed in serum of animals treated with SBRT and immunotherapy, compared to animals treated with SBRT. A paradoxical decrease in the density of effector CD3+ T cells was observed in tumor tissues that received combined SBRT and immunotherapy as compared to animals treated with SBRT only. In summary, these results obtained in a spontaneous large animal cancer model indicate that addition of OX40/TLR immunotherapy to SBRT modifies important immunological effects both locally and systemically.     

Cross-Omics Analysis of Fenugreek Supplementation Reveals Beneficial Effects Are Caused by Gut Microbiome Changes Not Mammalian Host Physiology

Herbal remedies are increasing in popularity as treatments for metabolic conditions such as obesity and Type 2 Diabetes. One potential therapeutic option is fenugreek seeds (Trigonella foenum-graecum), which have been used for treating high cholesterol and Type 2 diabetes. A proposed mechanism for these benefits is through alterations in the microbiome, which impact mammalian host metabolic function. This study used untargeted metabolomics to investigate the fenugreek-induced alterations in the intestinal, liver, and serum profiles of mice fed either a 60% high-fat or low-fat control diet each with or without fenugreek supplementation (2% w/w) for 14 weeks. Metagenomic analyses of intestinal contents found significant alterations in the relative composition of the gut microbiome resulting from fenugreek supplementation. Specifically, Verrucomicrobia, a phylum containing beneficial bacteria which are correlated with health benefits, increased in relative abundance with fenugreek. Metabolomics partial least squares discriminant analysis revealed substantial fenugreek-induced changes in the large intestines. However, it was observed that while the magnitude of changes was less, significant modifications were present in the liver tissues resulting from fenugreek supplementation. Further analyses revealed metabolic processes affected by fenugreek and showed broad ranging impacts in multiple pathways, including carnitine biosynthesis, cholesterol and bile acid metabolism, and arginine biosynthesis. These pathways may play important roles in the beneficial effects of fenugreek.     

测量不可测的:与可步行性相关的城市设计品质

本研究试图全面客观地衡量城市街道环境的与人们感受有关的品质.使用专家小组评级的方法,使得根据街道及其边缘的物质环境特征来衡量城市设计的五个品质——意象、围合空间、人的尺度、透明度和复杂性——成为可能.可操作的定义并不总与定性的定义相一致,可操作定义针对城市设计品质(urban design qualities)的性质提供了新见解.本研究的直接目的是为研究者提供(这五个城市设计品质的)可操作性定义,这样他们可以测量街道环境并测试其与步行行为之间的显著性联系.纽约市目前正在进行验证研究.最终目的是,根据本研究和其他后续研究的成果,来指导城市设计实践.