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Micromechanical response of fibre-reinforced materials using the boundary element technique
The Boundary Element Method (BEM) and the Embedded Cell Approach (ECA) have been used to analyse the effects of constituent material properties and fibre spatial distribution on the localised behaviour of a transversely loaded, unidirectional fibre-reinforced composite. The geometrical structures examined were perfectly periodic, uniformly spaced fibre arrangements in square and hexagonal embedded cells and ten cells in which 60 fibres were randomly placed within the matrix. The models involve both elastic fibres and matrix, with the interfaces between the different phases being fully bonded. The results indicate that both the fibre packing and the material properties of the constituent phases have a significant effect on the overall stress distribution and the magnitude of localised stress concentrations within a composite. Non-periodic arrangements give rise to higher local stresses, and the magnitudes of these stress concentrations have a strong dependence on the ligament length (distance between the two neighbouring fibres that have a common high-stress region), and to a lesser extent on the angle relative to the applied load (angle between a plane containing the two fibre centres and the applied load). Furthermore, analysis of a three-phase composite, comprised of a mixture of both stiff and compliant fibres, had higher stress concentrations than the equivalent two-phase composites
Benefits of current percolation in superconducting coated conductors
The critical currents of MOD/RABiTS and PLD/IBAD coated conductors have been
measured as a function of magnetic field orientation and compared to films
grown on single crystal substrates. By varying the orientation of magnetic
field applied in the plane of the film, we are able to determine the extent to
which current flow in each type of conductor is percolative. Standard
MOD/RABiTS conductors have also been compared to samples whose grain boundaries
have been doped by diffusing Ca from an overlayer. We find that undoped
MOD/RABiTS tapes have a less anisotropic in-plane field dependence than
PLD/IBAD tapes and that the uniformity of critical current as a function of
in-plane field angle is greater for MOD/RABiTS samples doped with Ca.EPSRC
US Department of Energ
Antibodies to Basement-Membrane Heparan-Sulfate Proteoglycans Bind to the Laminae Rarae of the Glomerular-Basement-Membrane (Gbm) and Induce Subepithelial Gbm Thickening
High Expression of Galectin-1, VEGF and Increased Microvessel Density are Associated with MELF Pattern in Stage I-III Endometrioid Endometrial Adenocarcinoma
This is the final version. Available on open access via the DOI in this recordBackground: In this study, we investigate the expression of markers of angiogenesis and microvessel density (MVD) in cases of microcystic, elongated and fragmented (MELF) pattern, with its prognostic role in the survival of endometrioid endometrial cancer (EA) patients. Materials and Methods: In this study, 100 cases of EA, 49 cases with MELF pattern and 51 without, were immunohistochemically stained for galectin-1, vascular endothelial growth factor (VEGF), and MVD. Morphometry and statistical (univariate and multivariate) analyses were performed to assess overall survival (OS) and disease-free survival. Results: The expression of VEGF (p<.001) and galectin-1 (p<.001), as well asMVD area (p=.0003) and number of vessels/mm2 (p=.0043), were significantly higher in the +MELF pattern group compared to the -MELF group. A low negative correlation between MELF-pattern and the number of days of survival (p<.001, r=-0.47) was also found. A low positive correlation of MELF-pattern with galectin-1 expression (p<.001, r=0.39), area of vessels/mm2 (p<.001, r=0.36), outcome of EA (p<.001, r = 0.42) and VEGF expression (p<.001, r=0.39) suggests potential pathological relevance of these factors in the prognosis of EA. A univariate survival analysis indicated a role for all parameters of survival. Multivariate Cox proportional hazard regression analysis revealed that only area of vessels/mm2 (hazard ratio [HR], 1.018; 95% confidence interval [CI], 1.002 to 1.033), galectin-1 (HR, 1.049; 95% CI, 1.025 to 1.074) and VEGF (HR, 1.049; 95% CI, 1.022 to 1.077) play key roles in OS. Conclusion: This study reports an increase in MVD, VEGF and galectin-1 expression in EA with MELF pattern and suggests that MELF pattern, along with the angiogenic profile, may be a prognostic factor in EA.FORCE Cancer CharityGomel State Medical Universit
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Lithium outdiffusion in LiTi<inf>2</inf>O<inf>4</inf> thin films grown by pulsed laser deposition
We report surface chemical cation composition analysis of high quality superconducting LiTiO thin films, grown epitaxially on MgAlO (111) substrates by pulsed laser deposition. The superconducting transition temperature of the films was ~13.8 K.
Surface chemical composition is crucial for the formation of a good metal/insulator interface for integrating LiTiO into full-oxide spin-filtering devices in order to minimize the formation of structural defects and increase the spin polarisation efficiency. In consideration of this, we report a detailed angle resolved x-ray photoelectron spectroscopy analysis. Results show Li segregation at the surface of LiTiO films. We attribute this process due to outdiffusion of Li toward the outermost LiTiO layers.The research leading to these results has received funding from the European Union Seventh Framework Programme ([FP7/2007–2013] [FP7/2007–2011]) under Grant agreement 316657 (SpinIcur), the European Research Council AdG (291442 “Superspin”), European Research Council AdG (247276 “NOVOX”) and the EPSRC (Equipment Account Grant EP/K035282/1).This is the final version of the article. It first appeared from Elsevier via https://doi.org/10.1016/j.jcrysgro.2016.09.01
Mode Conversion of Guided Waves by Defects in Pipes
The corrosion of pipework is a major problem for the oil and gas and petro-chemical industries. Large facilities operate hundreds of kilometres of pipes which may carry corrosive substances. General wall-thinning and localised pitting corrosion can occur both from the inside and the outside of pipe walls. A high proportion of these pipes are insulated, so that even the external defects cannot be detected by conventional NDE techniques without the expense of removing of the insulation
Laparoscopic Sleeve Gastrectomy in 108 Obese Children and Adolescents Ages 5 to 21 Years by Alqahtani AR, Antonisamy B, Alamri H, Elahmedi M, Zimmerman VA
A Clinical, Neuropathological and Genetic Study of Homozygous A467T POLG-Related Mitochondrial Disease
Mutations in the nuclear gene POLG (encoding the catalytic subunit of DNA polymerase gamma) are an important cause of mitochondrial disease. The most common POLG mutation, A467T, appears to exhibit considerable phenotypic heterogeneity. The mechanism by which this single genetic defect results in such clinical diversity remains unclear. In this study we evaluate the clinical, neuropathological and mitochondrial genetic features of four unrelated patients with homozygous A467T mutations. One patient presented with the severe and lethal Alpers-Huttenlocher syndrome, which was confirmed on neuropathology, and was found to have a depletion of mitochondrial DNA (mtDNA). Of the remaining three patients, one presented with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), one with a phenotype in the Myoclonic Epilepsy, Myopathy and Sensory Ataxia (MEMSA) spectrum and one with Sensory Ataxic Neuropathy, Dysarthria and Ophthalmoplegia (SANDO). All three had secondary accumulation of multiple mtDNA deletions. Complete sequence analysis of muscle mtDNA using the MitoChip resequencing chip in all four cases demonstrated significant variation in mtDNA, including a pathogenic MT-ND5 mutation in one patient. These data highlight the variable and overlapping clinical and neuropathological phenotypes and downstream molecular defects caused by the A467T mutation, which may result from factors such as the mtDNA genetic background, nuclear genetic modifiers and environmental stressors
Arginase attenuates inhibitory nonadrenergic noncholinergic nerve-induced nitric oxide generation and airway smooth muscle relaxation
BACKGROUND: Recent evidence suggests that endogenous arginase activity potentiates airway responsiveness to methacholine by attenuation of agonist-induced nitric oxide (NO) production, presumably by competition with epithelial constitutive NO synthase for the common substrate, L-arginine. Using guinea pig tracheal open-ring preparations, we now investigated the involvement of arginase in the modulation of neuronal nitric oxide synthase (nNOS)-mediated relaxation induced by inhibitory nonadrenergic noncholinergic (iNANC) nerve stimulation. METHODS: Electrical field stimulation (EFS; 150 mA, 4 ms, 4 s, 0.5 – 16 Hz)-induced relaxation was measured in tracheal preparations precontracted to 30% with histamine, in the presence of 1 μM atropine and 3 μM indomethacin. The contribution of NO to the EFS-induced relaxation was assessed by the nonselective NOS inhibitor L-NNA (0.1 mM), while the involvement of arginase activity in the regulation of EFS-induced NO production and relaxation was investigated by the effect of the specific arginase inhibitor nor-NOHA (10 μM). Furthermore, the role of substrate availability to nNOS in EFS-induced relaxation was measured in the presence of various concentrations of exogenous L-arginine. RESULTS: EFS induced a frequency-dependent relaxation, ranging from 6.6 ± 0.8% at 0.5 Hz to 74.6 ± 1.2% at 16 Hz, which was inhibited with the NOS inhibitor L-NNA by 78.0 ± 10.5% at 0.5 Hz to 26.7 ± 7.7% at 8 Hz (P < 0.01 all). In contrast, the arginase inhibitor nor-NOHA increased EFS-induced relaxation by 3.3 ± 1.2-fold at 0.5 Hz to 1.2 ± 0.1-fold at 4 Hz (P < 0.05 all), which was reversed by L-NNA to the level of control airways in the presence of L-NNA (P < 0.01 all). Similar to nor-NOHA, exogenous L-arginine increased EFS-induced airway relaxation (P < 0.05 all). CONCLUSION: The results indicate that endogenous arginase activity attenuates iNANC nerve-mediated airway relaxation by inhibition of NO generation, presumably by limiting L-arginine availability to nNOS
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