Non-linear elastic thermal stress analysis with phase changes

The non-linear elastic, thermal stress analysis with temperature induced phase changes in the materials is presented. An infinite plate (or body) with a circular hole (or tunnel) is subjected to a thermal loading on its inner surface. The peak temperature around the hole reaches beyond the melting point of the material. The non-linear diffusion equation is solved numerically using the finite difference method. The material properties change rapidly at temperatures where the change of crystal structures and solid-liquid transition occur. The elastic stresses induced by the transient non-homogeneous temperature distribution are calculated. The stresses change remarkably when the phase changes occur and there are residual stresses remaining in the plate after one cycle of thermal loading.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22560/1/0000105.pd

Vanadium Supported on Alumina and/or Zirconia Catalysts for the Selective Transformation of Ethane and Methanol

[EN] Vanadium supported on pure (Al2O3, ZrO2) or mixed zirconia-alumina (with Al/(Al + Zr) ratio of 0.75 or 0.25) catalysts have been prepared by wet impregnation, using homemade prepared supports. The catalysts have been characterized and tested in the oxidative dehydrogenation (ODH) of ethane and in the methanol aerobic transformation. The catalytic performance strongly depends on the nature of the metal oxide support. Thus, activity decreases in the order: VOx/ZrO2 > VOx/(Al,Zr-oxides) > VOx/Al2O3. On the other hand, at low and medium ethane conversions, the selectivity to ethylene presents an opposite trend: VOx/Al2O3 > VOx/(Al,Zr-oxides) > VOx/ZrO2. The different selectivity to ethylene at high conversion is due to the lower/higher initial ethylene formation and to the extent of the ethylene decomposition. Interestingly, VOx/(Al,Zr-oxides) with low Zr-loading present the lowest ethylene decomposition. The catalytic results obtained mainly depend on the nature of the supports whereas the role of the dispersion of vanadium species is unclear. In methanol oxidation, the catalysts tested present similar catalytic activity regardless of the support (Al2O3, ZrO2 or mixed Al2O3-ZrO2) but strong differences in the selectivity to the reaction products. Thus, dimethyl ether was mainly observed on alumina-supported vanadium oxide catalysts (which is associated to the presence of acidic sites on the surface of the catalyst, as determined by TPD-NH3). Formaldehyde was the main reaction product on catalysts supported on Zr-containing oxides (which can be related to a low presence of acid sites). In this article, the importance of the presence of acid sites in ethane ODH, which can be estimated using the methanol transformation reaction, is also discussed.The authors would like to acknowledge the DGICYT (CTQ2015-68951-C3-1-R and MAT2017-84118-C2-1-R projects), the Secretary of State for International Cooperation in Spain (Project AP/040992/11) and FEDER for financial support. B.S. also thanks the University of Valencia (UV-INV-AE16-484416).Benomar, S.; Masso Ramírez, A.; Solsona Espriu, BE.; Isaadi, R.; López Nieto, JM. (2018). Vanadium Supported on Alumina and/or Zirconia Catalysts for the Selective Transformation of Ethane and Methanol. Catalysts. 8(4):1-18. https://doi.org/10.3390/catal8040126S11884Chieregato, A., López Nieto, J. M., & Cavani, F. (2015). Mixed-oxide catalysts with vanadium as the key element for gas-phase reactions. Coordination Chemistry Reviews, 301-302, 3-23. doi:10.1016/j.ccr.2014.12.003Nieto, J. M. L. (2006). The selective oxidative activation of light alkanes. From supported vanadia to multicomponent bulk V-containing catalysts. Topics in Catalysis, 41(1-4), 3-15. doi:10.1007/s11244-006-0088-4Wachs, I. E. (2013). Catalysis science of supported vanadium oxide catalysts. Dalton Transactions, 42(33), 11762. doi:10.1039/c3dt50692dJames, O. O., Mandal, S., Alele, N., Chowdhury, B., & Maity, S. (2016). Lower alkanes dehydrogenation: Strategies and reaction routes to corresponding alkenes. Fuel Processing Technology, 149, 239-255. doi:10.1016/j.fuproc.2016.04.016Blasco, T., & Nieto, J. M. L. (1997). Oxidative dyhydrogenation of short chain alkanes on supported vanadium oxide catalysts. Applied Catalysis A: General, 157(1-2), 117-142. doi:10.1016/s0926-860x(97)00029-xKung, H. H., & Kung, M. C. (1997). Oxidative dehydrogenation of alkanes over vanadium-magnesium-oxides. Applied Catalysis A: General, 157(1-2), 105-116. doi:10.1016/s0926-860x(97)00028-8Cavani, F., & Trifirò, F. (1997). 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Oxidative Dehydrogenation of Alkanes over V-based Catalysts: Influence of Redox Properties on Catalytic Performance. Journal of Catalysis, 185(2), 324-332. doi:10.1006/jcat.1999.2467Argyle, M. D., Chen, K., Iglesia, E., & Bell, A. T. (2005). In situ UV−Visible Spectroscopic Measurements of Kinetic Parameters and Active Sites for Catalytic Oxidation of Alkanes on Vanadium Oxides†. The Journal of Physical Chemistry B, 109(6), 2414-2420. doi:10.1021/jp040166cAl-Ghamdi, S. A., & de Lasa, H. I. (2014). Propylene production via propane oxidative dehydrogenation over VOx/γ-Al2O3 catalyst. Fuel, 128, 120-140. doi:10.1016/j.fuel.2014.02.033SOLSONA, B., DEJOZ, A., GARCIA, T., CONCEPCION, P., NIETO, J., VAZQUEZ, M., & NAVARRO, M. (2006). Molybdenum–vanadium supported on mesoporous alumina catalysts for the oxidative dehydrogenation of ethane. Catalysis Today, 117(1-3), 228-233. doi:10.1016/j.cattod.2006.05.025Chen, S., Ma, F., Xu, A., Wang, L., Chen, F., & Lu, W. (2014). Study on the structure, acidic properties of V–Zr nanocrystal catalysts in oxidative dehydrogenation of propane. Applied Surface Science, 289, 316-325. doi:10.1016/j.apsusc.2013.10.158Elbadawi, A. H., Ba-Shammakh, M. S., Al-Ghamdi, S., Razzak, S. A., & Hossain, M. M. (2016). Reduction kinetics and catalytic activity of VO x /γ-Al 2 O 3 -ZrO 2 for gas phase oxygen free ODH of ethane. Chemical Engineering Journal, 284, 448-457. doi:10.1016/j.cej.2015.08.048Rostom, S., & de Lasa, H. I. (2017). Propane Oxidative Dehydrogenation Using Consecutive Feed Injections and Fluidizable VOx/γAl2O3 and VOx/ZrO2–γAl2O3 Catalysts. Industrial & Engineering Chemistry Research, 56(45), 13109-13124. doi:10.1021/acs.iecr.7b01369HERACLEOUS, E., & LEMONIDOU, A. (2006). Ni–Nb–O mixed oxides as highly active and selective catalysts for ethene production via ethane oxidative dehydrogenation. Part I: Characterization and catalytic performance. Journal of Catalysis, 237(1), 162-174. doi:10.1016/j.jcat.2005.11.002Skoufa, Z., Heracleous, E., & Lemonidou, A. A. (2015). On ethane ODH mechanism and nature of active sites over NiO-based catalysts via isotopic labeling and methanol sorption studies. Journal of Catalysis, 322, 118-129. doi:10.1016/j.jcat.2014.11.014Ipsakis, D., Heracleous, E., Silvester, L., Bukur, D. B., & Lemonidou, A. A. (2017). Reduction and oxidation kinetic modeling of NiO-based oxygen transfer materials. Chemical Engineering Journal, 308, 840-852. doi:10.1016/j.cej.2016.09.114Delgado, D., Solsona, B., Ykrelef, A., Rodríguez-Gómez, A., Caballero, A., Rodríguez-Aguado, E., … López Nieto, J. M. (2017). Redox and Catalytic Properties of Promoted NiO Catalysts for the Oxidative Dehydrogenation of Ethane. The Journal of Physical Chemistry C, 121(45), 25132-25142. doi:10.1021/acs.jpcc.7b07066Solsona, B., Concepción, P., López Nieto, J. M., Dejoz, A., Cecilia, J. A., Agouram, S., … Rodríguez Castellón, E. (2016). Nickel oxide supported on porous clay heterostructures as selective catalysts for the oxidative dehydrogenation of ethane. Catalysis Science & Technology, 6(10), 3419-3429. doi:10.1039/c5cy01811kGärtner, C. A., van Veen, A. C., & Lercher, J. A. (2014). Oxidative Dehydrogenation of Ethane on Dynamically Rearranging Supported Chloride Catalysts. Journal of the American Chemical Society, 136(36), 12691-12701. doi:10.1021/ja505411sTatibouët, J. M. (1997). Methanol oxidation as a catalytic surface probe. Applied Catalysis A: General, 148(2), 213-252. doi:10.1016/s0926-860x(96)00236-0Forzatti, P., Tronconi, E., Elmi, A. S., & Busca, G. (1997). Methanol oxidation over vanadia-based catalysts. Applied Catalysis A: General, 157(1-2), 387-408. doi:10.1016/s0926-860x(97)00026-4Wachs, I. E., Chen, Y., Jehng, J.-M., Briand, L. E., & Tanaka, T. (2003). Molecular structure and reactivity of the Group V metal oxides. Catalysis Today, 78(1-4), 13-24. doi:10.1016/s0920-5861(02)00337-1Shah, P. R., Baldychev, I., Vohs, J. M., & Gorte, R. J. (2009). Comparison of redox isotherms for vanadia supported on zirconia and titania. Applied Catalysis A: General, 361(1-2), 13-17. doi:10.1016/j.apcata.2009.03.036Baldychev, I., Gorte, R. J., & Vohs, J. M. (2010). The impact of redox properties on the reactivity of V2O5/Al2O3 catalysts. Journal of Catalysis, 269(2), 397-403. doi:10.1016/j.jcat.2009.11.022Hess, C. (2009). Nanostructured Vanadium Oxide Model Catalysts for Selective Oxidation Reactions. ChemPhysChem, 10(2), 319-326. doi:10.1002/cphc.200800585Smith, M. A., Zoelle, A., Yang, Y., Rioux, R. M., Hamilton, N. G., Amakawa, K., … Trunschke, A. (2014). Surface roughness effects in the catalytic behavior of vanadia supported on SBA-15. Journal of Catalysis, 312, 170-178. doi:10.1016/j.jcat.2014.01.011Wang, N., Qiu, J., Wu, J., You, K., & Luo, H. (2015). A Comparison of the Redox Properties of Bulk Vanadium Mixed Oxide Catalysts. 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Nox4 mediates skeletal muscle metabolic responses to exercise

OBJECTIVE: The immediate signals that couple exercise to metabolic adaptations are incompletely understood. Nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) produces reactive oxygen species (ROS) and plays a significant role in metabolic and vascular adaptation during stress conditions. Our objective was to determine the role of Nox4 in exercise-induced skeletal muscle metabolism. METHODS: Mice were subjected to acute exercise to assess their immediate responses. mRNA and protein expression responses to Nox4 and hydrogen peroxide (H2O2) were measured by qPCR and immunoblotting. Functional metabolic flux was measured via ex vivo fatty acid and glucose oxidation assays using (14)C-labeled palmitate and glucose, respectively. A chronic exercise regimen was also utilized and the time to exhaustion along with key markers of exercise adaptation (skeletal muscle citrate synthase and beta-hydroxyacyl-coA-dehydrogenase activity) were measured. Endothelial-specific Nox4-deficient mice were then subjected to the same acute exercise regimen and their subsequent substrate oxidation was measured. RESULTS: We identified key exercise-responsive metabolic genes that depend on H2O2 and Nox4 using catalase and Nox4-deficient mice. Nox4 was required for the expression of uncoupling protein 3 (Ucp3), hexokinase 2 (Hk2), and pyruvate dehydrogenase kinase 4 (Pdk4), but not the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc-1alpha). Global Nox4 deletion resulted in decreased UCP3 protein expression and impaired glucose and fatty acid oxidization in response to acute exercise. Furthermore, Nox4-deficient mice demonstrated impaired adaptation to chronic exercise as measured by the time to exhaustion and activity of skeletal muscle citrate synthase and beta-hydroxyacyl-coA-dehydrogenase. Importantly, mice deficient in endothelial-Nox4 similarly demonstrated attenuated glucose and fatty acid oxidation following acute exercise. CONCLUSIONS: We report that H2O2 and Nox4 promote immediate responses to exercise in skeletal muscle. Glucose and fatty acid oxidation were blunted in the Nox4-deficient mice post-exercise, potentially through regulation of UCP3 expression. Our data demonstrate that endothelial-Nox4 is required for glucose and fatty acid oxidation, suggesting inter-tissue cross-talk between the endothelium and skeletal muscle in response to exercise

Comparison of the structure and flexural properties of Moso, Guadua and Tre Gai bamboo

Bamboo is an underutilized resource widely available in countries with rapidly developing economies. Structural bamboo products, analogous to wood products, allow flexibility in the shape and dimensions of bamboo structural members. Here, the ultrastructure, microstructure, cell wall properties and flexural properties of three species of bamboo (Moso, Guadua and Tre Gai) are compared. At a given density, the axial modulus of elasticity of Guadua is higher than that of Moso or Tre Gai, which are similar; ultrastructural results suggest that Guadua has a higher solid cell wall stiffness. At a given density, their moduli of rupture are similar.National Science Foundation (U.S.) (OISE-1258574

MUC1 expression and anti-MUC1 serum immune response in head and neck squamous cell carcinoma (HNSCC): a multivariate analysis

BACKGROUND: HNSCC progression to adjacent tissue and nodes may be mediated by altered glycoproteins and glycolipids such as MUC1 mucin. This report constitutes a detailed statistical study about MUC1 expression and anti-MUC1 immune responses in relation to different clinical and pathological parameters which may be useful to develop new anti HNSCC therapeutic strategies. PATIENTS AND METHODS: Fifty three pre treatment HNSCC patients were included: 26 (49.1%) bearing oral cavity tumors, 17 (32.1%) localized in the larynx and 10 (18.8%) in the pharynx. Three patients (5.7%) were at stage I, 5 (9.4%) stage II, 15 (28.3%) stage III and 30 (56.6%) at stage IV. MUC1 tumor expression was studied by immunohistochemistry employing two anti-MUC1 antibodies: CT33, anti cytoplasmic tail MUC1 polyclonal antibody (Ab) and C595 anti-peptidic core MUC1 monoclonal antibody. Serum levels of MUC1 and free anti-MUC1 antibodies were detected by ELISA and circulating immune complexes (CIC) by precipitation in polyethylene glycol (PEG) 3.5%; MUC1 isolation from circulating immune complexes was performed by protein A-sepharose CL-4B affinity chromatography followed by SDS-PAGE and Western blot. Statistical analysis consisted in Multivariate Principal Component Analysis (PCA); ANOVA test (Tukey's test) was employed to find differences among groups; nonparametrical correlations (Kendall's Tau) were applied when necessary. Statistical significance was set to p < 0.05 in all cases. RESULTS: MUC1 cytoplasmic tail was detected in 40/50 (80%) and MUC1 protein core in 9/50 (18%) samples while serum MUC1 levels were elevated in 8/53 (15%) patients. A significant statistical correlation was found between MUC1 serum levels and anti-MUC1 IgG free antibodies, while a negative correlation between MUC1 serum levels and anti-MUC1 IgM free antibodies was found. Circulating immune complexes were elevated in 16/53 (30%) samples and were also statistically associated with advanced tumor stage. MUC1 was identified as an antigenic component of IgG circulating immune complexes. Moreover, poorly differentiated tumors were inversely correlated with tumor and serum MUC1 detection and positively correlated with node involvement and tumor mass. CONCLUSION: Possibly, tumor cells produce MUC1 mucin which is liberated to the circulation and captured by IgG antibodies forming MUC1-IgG-CIC. Another interesting conclusion is that poorly differentiated tumors are inversely correlated with tumor and serum MUC1 detection

Nonpsychotropic plant cannabinoids, cannabidivarin (CBDV) and cannabidiol (CBD), activate and desensitize transient receptor potential vanilloid 1 (TRPV1) channels in vitro: potential for the treatment of neuronal hyperexcitability

Epilepsy is the most common neurological disorder, with over 50 million people worldwide affected. Recent evidence suggests that the transient receptor potential cation channel subfamily V member 1 (TRPV1) may contribute to the onset and progression of some forms of epilepsy. Since the two nonpsychotropic cannabinoids cannabidivarin (CBDV) and cannabidiol (CBD) exert anticonvulsant activity in vivo and produce TRPV1-mediated intracellular calcium elevation in vitro, we evaluated the effects of these two compounds on TRPV1 channel activation and desensitization and in an in vitro model of epileptiform activity. Patch clamp analysis in transfected HEK293 cells demonstrated that CBD and CBDV dose-dependently activate and rapidly desensitize TRPV1, as well as TRP channels of subfamily V type 2 (TRPV2) and subfamily A type 1 (TRPA1). TRPV1 and TRPV2 transcripts were shown to be expressed in rat hippocampal tissue. When tested on epileptiform neuronal spike activity in hippocampal brain slices exposed to a Mg2+-free solution using multielectrode arrays (MEAs), CBDV reduced both epileptiform burst amplitude and duration. The prototypical TRPV1 agonist, capsaicin, produced similar, although not identical effects. Capsaicin, but not CBDV, effects on burst amplitude were reversed by IRTX, a selective TRPV1 antagonist. These data suggest that CBDV antiepileptiform effects in the Mg2+-free model are not uniquely mediated via activation of TRPV1. However, TRPV1 was strongly phosphorylated (and hence likely sensitized) in Mg2+-free solution-treated hippocampal tissue, and both capsaicin and CBDV caused TRPV1 dephosphorylation, consistent with TRPV1 desensitization. We propose that CBDV effects on TRP channels should be studied further in different in vitro and in vivo models of epilepsy

Measuring health-related quality of life in men with osteoporosis or osteoporotic fracture

<p>Abstract</p> <p>Background</p> <p>Osteoporosis is a serious health problem that worsens the quality of life and the survival rate of individuals with this disease on account the osteoporotic fractures. Studies have long focused on women, and its presence in men has been underestimated. While many studies conducted in different countries mainly assess health-related quality of life and identify fracture risks factors in women, few data are available on a Spanish male population.</p> <p>Methods/Design</p> <p>Observational study.</p> <p>Study population</p> <p>Men ≥ 40 years of age with/without diagnosed osteoporosis and with/without osteoporotic fracture included by their family doctor.</p> <p>Measurements</p> <p>The relationship between customary clinical risk factors for osteoporotic fracture and health-related quality of life in a Spanish male population. A telephone questionnaire on health-related quality of life is made.</p> <p>Statistical analysis</p> <p>The association between qualitative variables will be assessed by the Chi-square test. The distribution of quantitative variables by Student's t-test. If the conditions for using this test are not met, the non-parametric Mann-Whitney's U test will be used.</p> <p>The validation of the results obtained by the FRAX™ tool will be performed by way of the Hosmer-Lemeshow test and by calculating the area under the Receiver Operating Characteristic (ROC) curve (AUC). All tests will be performed with a confidence intervals set at 95%.</p> <p>Discussion</p> <p>The applicability and usefulness of Health-related quality of life (HRQOL) studies are well documented in many countries. These studies allow implementing cost-effective measures in cases of a given disease and reducing the costly consequences derived therefrom. This study attempts to provide objective data on how quality of life is affected by the clinical aspects involved in osteoporosis in a Spanish male population and can be useful as well in cost utility analyses conducted by health authorities.</p> <p>The sample selected is not based on a high fracture risk group. Rather, it is composed of men in the general population, and accordingly comparisons should not lead to erroneous interpretations.</p> <p>A possible bias correction will be ensured by checking reported fractures against healthcare reports and X-rays, or by consulting health care centers as applicable.</p

Prediction of absolute risk of fragility fracture at 10 years in a Spanish population: validation of the WHO FRAX ™ tool in Spain

<p>Abstract</p> <p>Background</p> <p>Age-related bone loss is asymptomatic, and the morbidity of osteoporosis is secondary to the fractures that occur. Common sites of fracture include the spine, hip, forearm and proximal humerus. Fractures at the hip incur the greatest morbidity and mortality and give rise to the highest direct costs for health services. Their incidence increases exponentially with age.</p> <p>Independently changes in population demography, the age - and sex- specific incidence of osteoporotic fractures appears to be increasing in developing and developed countries. This could mean more than double the expected burden of osteoporotic fractures in the next 50 years.</p> <p>Methods/Design</p> <p>To assess the predictive power of the WHO FRAX™ tool to identify the subjects with the highest absolute risk of fragility fracture at 10 years in a Spanish population, a predictive validation study of the tool will be carried out. For this purpose, the participants recruited by 1999 will be assessed. These were referred to scan-DXA Department from primary healthcare centres, non hospital and hospital consultations. Study population: Patients attended in the national health services integrated into a FRIDEX cohort with at least one Dual-energy X-ray absorptiometry (DXA) measurement and one extensive questionnaire related to fracture risk factors. Measurements: At baseline bone mineral density measurement using DXA, clinical fracture risk factors questionnaire, dietary calcium intake assessment, history of previous fractures, and related drugs. Follow up by telephone interview to know fragility fractures in the 10 years with verification in electronic medical records and also to know the number of falls in the last year. The absolute risk of fracture will be estimated using the FRAX™ tool from the official web site.</p> <p>Discussion</p> <p>Since more than 10 years ago numerous publications have recognised the importance of other risk factors for new osteoporotic fractures in addition to low BMD. The extension of a method for calculating the risk (probability) of fractures using the FRAX™ tool is foreseeable in Spain and this would justify a study such as this to allow the necessary adjustments in calibration of the parameters included in the logarithmic formula constituted by FRAX™.</p