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Abstract: In order to reveal the high-velocity deformation mechanisms of 5052 aluminum alloy sheets, this work compares the dynamic plastic deformation behavior and the microstructure evolutions with those of the quasi-static case by scanning electron microscopy (SEM) observations, electron back scattering diffraction (EBSD) analysis, and transmission electron microscopy (TEM) studies. Results show that the dynamic process exhibits a very different macro fracture shape and a much similar micro deformation pattern as compared with the quasi-static case, and under both conditions, the dislocation-slip mechanism works during deformation. For the shock effect of high-velocity deformation, much denser dislocations are generated and the tendency of cross-slip of dislocations increases. The dislocation bands are more narrow and denser than those shown in the quasi-static case, and a much more uniform dislocation configuration is also exhibited after dynamic loadings. In addition, under dynamic conditions, the existing of pre-strain will introduce an accommodated effect on the dynamically induced dislocations, a slight reduction of density combining with a higher movement tendency. The characteristics of multi-slips and homogenization effect of dislocations under dynamic conditions will result in much higher plasticity and strength of materials over the quasi-static ones. [Copyright &y& Elsevier]

Abstract: The effects of geometric structures of coated particles on the dielectric properties of composites are derived. For a dilute suspension of coated ellipsoids with dielectric core and metallic shell embedded in a linear dielectric host, we find that the optical absorption peak of maximum wavelength shifts due to the core–shell structure, and has a significant red shift from that of pure metallic particles, especially for thin metallic coating. Meanwhile, the shape of coated ellipsoid can tune the absorption peak in a wide frequency range by properly choosing the depolarization factor. When the composite is made of linear materials, we obtain the condition of partial resonance for coated ellipsoids, which is relative to the particle shape. Under such a condition, the property of the inner core can be extended to the outer shell. When the inner core is a weakly nonlinear material, the nonlinearity of the composite can be greatly enhanced at the linear partial resonance. To achieve the condition of partial resonance, a metallic shell may be suitable to reach the case if the frequency is far away from the plasmon frequency. It indicates that the nonlinearity can also be enhanced in terms of the geometric structure of materials as well as the properties of themselves. [Copyright &y& Elsevier]

The classic renin–angiotensin system (RAS) is a complex system in which angiotensin II (Ang II) has been identified as an important endogenous regulator that influences both smooth muscle contraction and cell growth. Although a local RAS is known to exist in the gastrointestinal tract, it is unclear whether Ang II is involved in the loss of gastric interstitial cells of Cajal (ICC) in diabetic mice. The present study was designed to investigate the effect of Ang II on ICC survival in streptozotocin (STZ)-induced diabetic mice. Western blot, immunofluorescence, isometric muscle recording, enzyme-linked immunosorbent assay (ELISA) and a cell counting kit-8 were used in this research. Our results demonstrate that the c-Kit and membrane-bound stem cell factor (mSCF) protein expression levels in gastric smooth muscle were decreased in STZ-induced diabetic mice. However, the angiotensin receptor type 1 (AT1R) expression levels in gastric smooth muscle and angiotensin-converting enzyme (ACE) expression levels in gastric mucosa were increased. The effect of Ang II on the tonic contraction of gastric smooth muscle was potentiated in diabetic mice, and the plasma Ang II level was enhanced. Ang II increased mSCF expression, cell proliferation, and Akt-Ser473 phosphorylation in cultured gastric smooth muscle cells (GSMCs). These effects were reduced by specific inhibitors ZD7155 (an AT1R antagonist) and LY294002 (a PI3-kinase inhibitor). Our results suggest that Ang II increases mSCF expression and cell proliferation in cultured GSMCs in a PI3K/Akt signaling-dependent manner. ACE and AT1R up-regulation in the stomach may help compensate for ICC loss in STZ-induced diabetic mice. [ABSTRACT FROM AUTHOR]

Abstract: To understand the phytoremediation capability of poplar 107 (Populus × euramericana cv. ‘Neva’) and poplar 118 (Populus nigra × Populus ussuriensis) stressed by cadmium (Cd), a hydroponic culture was performed. Cd accumulation and translocation were evaluated, activities of antioxidant enzymes and lipid peroxidation were assessed and ultrastructural alterations in root tip cells were investigated. The superoxide dismutase (SOD) activity in the leaves of the two cultivars exposed to 50μM and 100μM Cd was significantly higher (P <0.05) than that of the control and SOD activity in the roots was low. The levels of peroxisome (POD) and catalase (CAT) were significantly higher (P <0.05) than those of the control. The content of malondialdehyde (MDA) increased during the treatment. The morphological alterations in plasma membrane, dictyosomes and ER reflect the features of detoxification and tolerance under Cd stress. Reduction in number of ER, mitochondria and dictyosomes, swelling of rER and significant expansion of mitochondrial cristae were observed. The plasma membrane was damaged and cytoplasmic electron density increased, revealing a pool-like structure. Some electronic-dense granules occurred in the cytoplasm or cell wall. Plasmolysis occurred in some cells. The poplar cultivars used in the present study could be efficient phytoextraction plants as they have considerable ability to accumulate Cd (Cd concentration in shoot exceeding 0.01% (w/w)). The alterations of antioxidant enzymes and MDA content and ultrastructural changes in the poplar cultivars can serve as useful biomarkers in ecotoxicological tests with Cd. [Copyright &y& Elsevier]

Abstract: Background: Anti-CD25 monoclonal antibodies (Mabs) have been evaluated for the treatment of steroid-refractory acute graft-versus-host disease (GVHD) in patients undergoing hematopoietic stem cell transplantation (HSCT) mainly with matched donors for years, but there is little attention concerning patients with unmanipulated human leukocyte antigen (HLA)-mismatched/haploidentical transplantations. We investigated the efficacy and safety of the chimeric Mab, basiliximab, to treat steroid-refractory acute GVHD after unmanipulated mismatched/haploidentical HSCT. Methods: Fifty-three patients who developed steroid-refractory acute GVHD between July 2005 and July 2009 were treated at our institute with basiliximab. No prisoners were used in this study. Results: Forty-six among 53 patients responded, including 37 complete remissions at a median response of 6 days from Mab initiation. There were 29 episodes of viral reactivations, 25 bacterial infections, and 11 probable fungal infections. Thirty-four out of 49 patients who could be evaluated developed chronic GVHD. Twenty-eight of 53 subjects (52.8%) were alive at a median follow-up of 16 months (range, 2–57) posttransplantation. The Kaplan–Meier probability of a 3-year event-free survival was 47.7%. The causes of death were infection alone (n = 15), progressive GVHD with infection (n = 3), relapse (n = 3), and other etiologies (n = 4). Conclusion: These data suggested that basiliximab was effective to treat steroid-refractory acute GVHD after unmanipulated HLA-mismatched/haploidentical stem cell transplantation. [Copyright &y& Elsevier]