Thermal properties of Poly(trimethylene terephthalate)/Poly(ethylene terephthalate) melt blends

The thermal behavior, morphology, ester-interchange reaction of Poly(trimethylene terephthalate) (PTT)/Poly(ethylene terephthalate) (PET) melt blends were investigated over the whole composition range(xPTT/(1-x)PET) using a twinscrew Brabender. The melt blends were analyzed by differential scanning calorimetry (DSC), nuclear magnetic resonance spectroscopy (¹³C-NMR), and scanning electron microscopy (SEM). Single glass transition temperature (T _g ) and cold crystallization temperature (T _cc ) were observed in all melt blends. Melt blends were found to be due to the ester-interchange reaction in PTT/PET blend. Also the randomness of copolymer increases because transesterification between PTT and PET increases with increasing blending time. This reaction increases homogeneity of the blends and decreases the degree of crystallinity of the melt blends. In PTT-rich blends, mechanical properties decrease with increase of PET content compared with that of pure PTT. And, in PET-rich blends, tensile modulus decreases with increase of PTT content, but tensile strength and elongation is similar to that of pure PET.     

Sodium Reduction in Bread Using Low‐Sodium Sea Salt

Yeast bread is a major contributor of sodium in the American diet. Because of its functional impact on dough rheology and the quality of the final baked product, simply reducing the level of sodium chloride (salt) in the formula or replacing it with salt substitutes has found minimal success. The objective of this study was to determine the effect of sea salt containing 57 or 64% less sodium than common sea salt on the breadmaking properties and consumer acceptability of bread. The sodium content of the salt had no effect on dough strength, mixing time, gas production, loaf volume, or crumb grain. The flavor and overall liking of breads containing sea salt with 57 and 64% less sodium content were scored only slightly lower than bread containing the control salt by an untrained panel of 118 consumers. No difference in texture and no unacceptable flavor notes in the bread made with reduced‐sodium salts were reported. Thus, it appears that use of reduced‐sodium sea salt is a satisfactory alternative to reduce the sodium content of bread.     

A mixture of trans, trans conjugated linoleic acid induces apoptosis in MCF-7 human breast cancer cells with reciprocal expression of Bax and Bcl-2

The growth inhibitory effect of a mixture of trans, trans conjugated linoleic acid isomers (t, t CLA) was investigated in a human breast cancer cell line, MCF-7, with references to c9, t11 CLA, t10, c12 CLA, and linoleic acid. The t, t CLA treatment effectively induced a cytotoxic effect in a time-dependent (0-6 days) and concentration-dependent (0-40 microM) manner, as compared to the reference and control treatments. The apoptotic parameters were measured on cells treated with 40 microM t, t CLA for 4 days. The occurrence of the characteristic morphological changes and DNA fragmentation confirmed apoptosis. The t, t CLA treatment led to an increase in the level of p53 tumor suppressor protein and Bax protein, but suppressed the expression of Bcl-2 protein. In addition, cytochrome c was released from the mitochondria into the cytosol, and the activation of caspase-3 led to the cleavage of poly(ADP-ribose) polymerase (PARP). Moreover, the composition of the linoleic and arachidonic acids was decreased in cellular membranes. These findings suggest that incorporation of t, t CLA in the membrane induces a mitochondria-mediated apoptosis that can enhance the antiproliferative effect of t, t CLA in MCF-7 cells.     

LDL-antioxidant pterocarpans from roots of Glycine max (L.) Merr

The methanolic root extract of Glycine max (L.) Merr. was chromatographed, which yielded 10 flavonoids, including three isoflavones 1-3, five pterocarpans 4-8, one flavonol 9, and one anthocyanidin 10. All isolated compounds were examined for LDL-antioxidant activities using four different assay systems on the basis of Cu2+-mediated oxidation. Among them, seven compounds showed potent LDL-antioxidant activities in the thiobarbituric acid reactive substances (TBARS) assay, the lag time of conjugated diene formation, relative electrophoretic mobility (REM), and fragmentation of apoB-100 on copper-mediated LDL oxidation. Three pterocarpans 4, 6, and 7, never reported as LDL-antioxidant, showed potent activities with IC50 values of 19.8, 0.9, 45.0 microM, respectively, in comparison with probucol (IC50 = 5.6 microM) as positive control. Interestingly, coumestrol 6 (IC50 = 0.9 microM) showed 20 times more activity in the TBARS assay than genistein (IC50 = 30.1 microM) and daidzein (IC50 = 21.6 microM), representative antioxidants in soybean. Moreover, coumestrol 6 had an extended lag time of 190 min at 3.0 microM in measuring conjugated diene formation, while both genistein (120 min) and daidzein (93 min) lag times were extended to less than 120 min at the same concentration.     

Control of Shear Thickening Onsets by Nanoparticles

With various applicability of shear thickening fluids (STFs), control of rheological properties of STFs has been a major interest to industry. While carbon nanotubues and graphene have often been employed as fillers of STFs, little has been examined for their individual and combined effects on shear thickening behavior. In this study, the onset of viscosity increase of STFs was examined for the addition of: 1D functionalized multi-walled carbon nanotubes (fMWCNTs); 2D reduced graphene oxides (rGO); 3D network of MWCNTs-rGO hybrids (H); and spherical iron oxides (Fe₃O₄). To overcome the poor dispersibility of carbon particles, carbon nanotubes were functionalized to attach carboxylic groups (fMWCNTs), and graphene oxides (GOs) were reduced using TiO₂ particles. Large hydrodynamic diameters of fMWCNT, rGO, and their hybrids of percolated network facilitated the interactions with silica particles in STF, decreasing the onset of shear thickening. Among the tested particles, STF with hybrids (H-STF) exhibited the lowest critical shear rate and the highest viscosity, due to the hybrid’s 3D network structure in which long and tortuous fMWCNTs bridged adjacent rGOs. The addition of Fe₃O₄ to HSTF shifted the shear thickening onset to a higher shear rate. The results demonstrate that the shear thickening onsets can be controlled by the selective additions of nanoparticles.     

Thermal Insulation Performance of Cotton and PET-based Hybrid Fabrics Impregnated with Silica Aerogel via a Facile Dip-dry Process

We report the morphological features and thermal insulation properties of a series of cotton- and PET-based hybrid fabrics impregnated with silica aerogel. For the purpose, commercially available cotton and PET knitted fabrics were dipped into aqueous dispersions including different silica aerogel contents, dried, and stacked to 1, 3, and 5 layers. The SEM images revealed that the silica aerogel particles were well incorporated into cotton or PET knitted fabrics. The thermal insulating performance of the hybrid fabrics as functions of the silica aerogel content and the number of layers of stacked fabrics were characterized by monitoring the surface temperatures of the fabrics on a plate with a wide temperature range of ~50-80 oC using an infrared camera. The higher thermal insulation performance was attained for both cotton- and PET-based hybrid fabrics with higher silica aerogel contents. In addition, 3-layered hybrid fabrics exhibited noticeably improved thermal insulation performance, compared to 1- or 5-layered fabrics. The thermal insulation property of the cotton-based hybrid fabrics was dominantly influenced by silica aerogel than that of PET-based hybrid fabrics. The overall results demonstrated that the cotton- and PET-based hybrid fabrics with silica aerogel manufactured by a facile dip-dry process could be utilized as protective garments, heat-sensitive devices, pipes, automotive, aircrafts, and buildings for thermal insulation applications.     

Antioxidant Properties of Scomber japonicus Hydrolysates Prepared by Enzymatic Hydrolysis

The antioxidant properties of the Pacific chub mackerel (Scomber japonicus) muscle protein hydrolysates prepared by enzymatic hydrolysis were investigated. After enzyme hydrolysis at 50°C for 60 min, more than 80% of the S. japonicus muscle protein was hydrolyzed. The highest 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity (71.69%) occurred in whole muscle protein hydrolysates treated at 50°C for 30 min with Protamex, and the highest 2,2?-azino-bis(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) radical-scavenging activity (95.39%) was observed in white muscle protein hydrolysates treated at 50°C for 30 min with Neutrase. The highest superoxide dismutase (SOD)-like activity (32.84%) was recorded in white muscle protein hydrolysates treated at 50°C for 120 min with Protamex. Changes in the molecular weight distribution of S. japonicus muscle proteins after enzymatic hydrolysis were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). A robust and a convenient enzyme hydrolysis technique for obtaining S. japonicus muscle protein hydrolysates with useful biological activities, within a short time (<2 h) is proposed.     

Comparisons of bearing properties for various oriented glulam using digital image correlation

The goal of this study was to analyze the bearing properties of the differently oriented glulam using digital image correlation (DIC). Six differently oriented specimens associated with three anatomical directions including longitudinal (L), radial (R), and tangential (T), and 12-mm drift pins were used to analyze the bearing properties, including yield load and bearing strength. The highest bearing strength of 22.57 MPa from RL was found, whereas the lowest bearing strength of 6.47 MPa from LR was found. Different strain distributions were observed from the differently oriented bearing specimens using DIC. Different failure ratios of the differently oriented specimens were highly related to the strain distributions. Although the bearing properties were found to be different between the differently oriented specimens, for the connection design aspect, the bearing properties of glulam could be grouped as RL and TL specimens, RT and TR specimens, and LR and LT specimens.