Inhibitory effect of aqueous spinach extract on degranulation of RBL-2H3 cells

The inhibitory effect of an aqueous extract from spinach on degranulation of RBL-2H3 cells is herein reported. The extract significantly suppressed antigen-induced degranulation in a dose-dependent manner without affecting cell viability. Active substances in the extract were heat-stable and trypsin-resistant with molecular weights ranging from 500 Da to 14 kDa. The extract inhibited elevation of the intracellular Ca²⁺ concentration caused by stimulation by antigen, while not suppressing degranulation induced by a calcium ionophore A23187. Immunoblot analysis revealed that the inhibitory effect results from downregulation of phosphorylation of both Syk kinase and phosphatidylinositol 3-kinase in the signalling pathways involved in degranulation caused by the antigen–antibody interaction. Taken together, these findings suggest that aqueous spinach extract has an anti-allergic activity that controls degranulation.     

Division of mitochondria in cultured human fibroblasts

Ovate mitochondria in cultured human fibroblasts divide by pinching. In the process, as observed by transmission electron microscopy, a deep incisure of the surface membranes separates the organelle into two lobes connected by a slender isthmus. A single element of smooth endoplasmic reticulum (SER) invariably accompanies each incisure, extending deep into the cleft. When the ingrowing membranes meet and fuse with the antipodal membranes, fission occurs. Elongated mitochondria that give no indication of division often are cloaked by a single, continuous cistern of SER. Microsc. Res. Tech. 76:1213–1216, 2013. © 2013 Wiley Periodicals, Inc.     

Identification of a novel food-derived collagen peptide,hydroxyprolyl-glycine,in human peripheral blood by pre-column derivatisation with phenyl isothiocyanate

Peptides in the blood of subjects before and after collagen hydrolysate ingestion were fractionated by ion exchange and size-exclusion chromatographies and then derivatised with phenyl isothiocyanate. The derivatives were characterised by reserved phase (RP)-HPLC. Prolyl-hydroxyproline (Pro-Hyp), which has been identified in the previous studies, was detected as a major food-derived collagen peptide in the blood of all subjects (n = 5). Another major peptide was identified as hydroxyprolyl-glycine (Hyp-Gly) in the blood of four subjects, which has not been detected in previous studies. The ratio of Hyp-Gly to Pro-Hyp depended on subjects and ranged from 0.00 to 5.04. Hyp-Gly was less susceptible to human serum peptidase than Pro-Hyp. Hyp-Gly enhanced the growth of mouse primary fibroblasts on collagen gels in a higher extent than Pro-Hyp. These findings suggest that Hyp-Gly plays a significant role in exerting the biological effects by ingestion of collagen hydrolysate.     

Load Tests of Piled Raft Models with Different Pile Head Connection Conditions and Their Analyses

A series of experimental and analytical studies on the behaviours of model pile groups and model piled rafts in dry sand subjected to static vertical loading and static cyclic horizontal loading were carried out in order to investigate the influence of various pile head connection conditions between the raft and the piles on the behaviours of the foundations models and to examine the applicability of an simplified analytical method to simulate the load tests. In the load tests, the behaviours of the model foundations were investigated in detail, with particular focus on cyclic horizontal loading, and behaviour such as horizontal stiffness and the rotation of the foundation, the load proportions between the raft and the piles, and the bending moments and shear forces generated in the piles. A simplified three-dimensional deformation analysis method was used to simulate the experiments.     

Phase transformation and precipitation hardening behavior of Cr and Fe in BS40CrFeSn alloy

Phase transformation and precipitation hardening behavior of the water atomized copper alloy powder was studied by aging treatment, to develop high strength Cu–40Zn–X (X: Cr, Fe, Sn) alloys by powder metallurgy process. Super-saturated solid solution elements of Cr and Fe are formed in the brass matrix, and single β phase was retained in the raw powder after water atomization. Solid solubility of Cr and Fe decreased with increase of aging temperature, and phase transformation evolved from single β phase to α + β duplex phase structure after aged at the elevated temperature of 773 K and over. It was clarified that Cr showed higher precipitation potential than Fe in the brass matrix. The hardness depended strongly upon solid solubility of Cr and Fe, and upon phase transformation.     

Numerical and Experimental Studies of an Arc-heated Nonequilibrium Nozzle Flow

The arc-heated high-temperature gas is rotationally and vibrationally excited, and partially dissociated and ionized. When such gas flows inside a nozzle, energy transfers from rotational and vibrational energy modes to translational energy mode, and, in addition, recombination reactions occur. These processes are in thermal and chemical nonequilibrium. The present computations treat arc-heated nonequilibrium nozzle flows using a six temperature model (translational, rotational, N2 vibrational, O2 vibrational, NO vibrational and electron temperatures), and nonequilibrium chemical reactions of air. From the calculated flow properties, emission spectra at the nozzle exit were re-constructed by using the code for computing spectra of high temperature air. On the other hand, measurements of N2+(1-) emission spectra were conducted at the nozzle exit in the 20 kW arc-heated wind tunnel. Vibrational and rotational temperatures of N2 were determined using a curve fitting method on N2+(1-) emission spectra, with     

Simulation of two regime sodium flows in a parallel plate channel during buoyancy-driven flow

Due to the remaining decay heat, the reactor core has yet to be cooled after shutdown. As the reactor power is low, the core can be sufficiently cooled by natural convection. The coolant flow is driven by buoyancy, as the heated fluid decreases its density. During buoyancy-driven flow, a reverse flow may take place when a heat sink exists close to the heat source, such as in a wall (edge) or corner subchannels. For simplicity in applying boundary condition, the reverse flow is simulated by two parallel plates, one as a heat source having positive heat flux and the other as heat sink with negative heat flux.     

A Facile Approach to Chemically Modified Graphene and its Polymer Nanocomposites

A scalable approach for the mass production of chemically modified graphene has yet to be developed, which holds the key to the large‐scale production of stable graphene colloids for optical electronics, energy conversion, and storage materials, catalysis, sensors, composites, etc. Here, a facile approach to fabricating covalently modified graphene and its polymer nanocomposites is presented. The method involves: i) employing a common furnace, rather than a furnace installed with a quartz tube and operated in inert gas as required in previous studies, to treat a commercial graphite intercalation compound with thermal shocking and ultrasonication and fabricate graphene platelets (GnPs) with a thickness of 2.51 ± 0.39 nm that contain only 7 at% oxygen; ii) grafting these GnPs with a commercial, long‐chain surfactant, which is able to create molecular entanglement with polymer matrixes by taking advantage of the reactions between the epoxide groups of the platelets and the end amine groups of the surfactant, to produce chemically modified graphene platelets (m‐ GnPs); and iii) solution‐mixing m‐GnPs with a commonly used polymer to fabricate nanocomposites. These m‐GnPs are well dispersed in a polymer with highly improved mechanical properties and a low percolation threshold of electrical conductivity at 0.25 vol%. This novel approach could lead to the future scalable production of graphene and its nanocomposites.     

The Role of Momilactones in Rice Allelopathy

Large field screening programs and laboratory experiments in many countries have indicated that rice is allelopathic and releases allelochemical(s) into its environment. A number of compounds, such as phenolic acids, fatty acids, phenylalkanoic acids, hydroxamic acids, terpenes, and indoles, have been identified as potential rice allelochemicals. However, the studies reviewed here demonstrate that the labdane-related diterpenoid momilactones are the most important, with momilactone B playing a particularly critical role. Rice plants secrete momilactone B from their roots into the neighboring environments over their entire life cycle at phytotoxic levels, and momilactone B seems to account for the majority of the observed rice allelopathy. In addition, genetic studies have shown that selective removal of the momilactones only from the complex mixture found in rice root exudates significantly reduces allelopathy, demonstrating that these serve as allelochemicals, the importance of which is reflected in the presence of a dedicated momilactone biosynthetic gene cluster in the rice genome.