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The role of the type of layered silicate platelets, OMMT and rectorite on the mechanical properties, aging resistance and oxygen permeation properties of HNBR/layered silicate nanocomposites was investigated. The effect of peroxide vulcanising agent on the dispersion of layered silicate in the HNBR matrix was also studied. HNBR was mechanically mixed with layered silicate via melt blending method. The results of the test show remarkable improvement in tensile strength, tear strength, aging resistance and oxygen permeation properties of HNBR nanocomposites than that of unfilled HNBR. It is obvious that the OMMT filled nanocomposites have far better properties than that of rectorite filled HNBR.

The herb Astragalus membranaceusis used in traditional Chinese medicine to boost immunity. This study investigated the effects of Astragaluspolysaccharides (APS) and astragalosides (AS) on the phagocytosis of Mycobacterium tuberculosisby macrophages. Peritoneal macrophages were obtained by peritoneal lavage from mice stimulated by starch gravy culture medium and cultured with M. tuberculosisand varying concentrations of APS and AS. Phagocytotic activity was measured using a real-time polymerase chain reaction assay to detect M. tuberculosisDNA. Levels of interleukin-1β, interleukin-6 and tumour necrosis factor-α secreted by activated macrophages in the culture supernatant were determined using an enzyme-linked immunosorbent assay. Macrophage phagocytotic activity and secreted cytokine levels were significantly increased after treatment with APS and AS. This study provides evidence that APS and AS have strong promoting effects on the phagocytosis of M. tuberculosisby macrophages and the secretion of interleukin-1β, interleukin-6 and tumour necrosis factor-α by activated macrophages.

The trilayered films of La2/3Ca1/3MnO3/(La0.3Nd0.7)2/3Ca1/3MnO3/La2/3Ca1/3MnO3 (LNL) with different thickness combinations are prepared by dc magnetron sputtering technique. The electrical transport and magnetic properties of the LNL films are investigated systematically. It is found that the performance of magnetoresistance effect in some of the LNL films can be improved. The electrical transport are mainly determined by the top-layer of La2/3Ca1/3MnO3 when the thickness of top-layer is larger than 150 nm, and the middle-layer and crossover-layer in the interface between top-layer and middle-layer caused by the diffusion of La³⁺ and Nd³⁺ ions will play an important role with decreasing the thickness of top-layer. However, the magnetic properties are determined by the whole of films associated with the crossover-layers and the strong magnetic coupling interaction between the inter-layers. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The influence of Nd doping on the charge ordering (CO) state of polycrystalline (La1−zNdz)Sr2Mn2O7 (z = 0, 0.2, 0.5, 0.7, 1) is investigated by magnetic and electric transport property measurements. The temperature dependence of the resistivity of all samples shows the formation of the CO state at above 200 K and the re-entrant-type CO state exists only when z ≤ 0.7. The result of magnetization measurements shows that all samples exhibit an antiferromagnetic (AFM) transition accompanying the existence of the CO state at TCO. Double peaks of the M(T) curve are observed for heavily doped samples with z ≥ 0.5 due to the disorder of the Nd doping. The transport mechanism of all the samples is also discussed. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Intercellular adhesion molecule-1 (ICAM-1) is a glycoprotein expressed on endothelial cells that facilitates leukocyte adhesion. To test the hypothesis that reduction of leukocytes in an ischemic lesion reduces ischemic brain damage, we measured the effect of administration of an anti-ICAM-1 monoclonal antibody on ischemic brain damage after transient middle cerebral artery occlusion in the rat. ICAM-1 expression increased in the ischemic lesion, and the lesion volume was significantly reduced by 41 in the anti-ICAM-1 antibody group compared with the control group (p< 0.05). Numbers of polymorphonuclear leukocytes (PMNs) were significantly reduced in the cortices of the anti-ICAM-1 antibody group compared with the control animals (p< 0.05). Our data indicate that administration of anti-ICAM-1 antibody results in a significant reduction of ischemic brain damage concomitant with a reduction of PMNs in the lesion after transient focal cerebral ischemia in the rat.

We explored the therapeutic potential of a peptide (F20) derived from the filamentous hemagglutinin of Bordetella pertussisin a model of ischemic cell injury after transient (2 hours) middle cerebral artery (MCA) occlusion in the rat. Animals were divided into two groups-(1) F20 peptide group: rats (n = 11) were subjected to 2 hours of transient MCA occlusion, and F20 peptide was administered intravenously (50 nmol) at 0 hours of reperfusion and intraperitoneally (150 nmol/dose) at 2, 4, 6, 8, 22, and 30 hours of reperfusion; (2) control group: rats (n = 10) were administered peptide F23 (a scrambled version of peptide F20) with the same experimental protocol as the F20 peptide group. Forty-six hours after reperfusion, animals were sacrificed, and brain tissue was stained with triphenyltetrazolium chloride for evaluation of tissue damage. To measure neutrophil numbers in ischemic tissue, myeloperoxidase (MPO) immunostaining was performed on a coronal cerebral section in each animal. There was a significant reduction of ischemic infarct volume (36, p<0.05) in the F20 group of animals compared with the F23 group. The area of the ischemic lesion was highly correlated with the numbers of the immunoreactive MPO cells (r = 0.78, p<0.001). The data demonstrate that the F20 peptide significantly reduces infarct volume and intraparenchymal neutrophil numbers after transient MCA occlusion.

Model polymer composites containing carbon nanotube (CNTs) and graphene oxide (GO) grafted carbon fiber provides a means to investigate the influence of nanostructures on interfacial properties. The morphology, together with the change of composition was related to the interfacial performance of model composites, which was studied using scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). In addition, the wetting and surface energy along with contact angles was explored using dynamic contact angle analysis test (DCAT). Furthermore A significant improvement of the interfacial shear strength (IFSS), measured by a micromechanical test derived from the pull-out test, was obtained.