Material characterization of superplastically formed titanium (Ti-6Al-2Sn-4Zr-2Mo) sheet

The aerospace industry has focused considerable interest on the near-alpha titanium alloy Ti-6Al-2Sn-4Zr-2Mo (Ti-6242) because of both its high-temperature properties and its superplastic forming (SPF) capabilities. This paper describes current research to characterize selected mechanical properties of Ti-6242 sheet in the SPF-strained condition, both with and without heat treatment, and compares the results with those obtained on as-received material. Tensile and creep tests were conducted, and metallographic analysis was performed to show the effect of 100 to 700 percent SPF strain on titanium properties. Analysis shows that as a result of SPF processing, both tensile and yield strengths, as well as elongation, are moderately reduced. Creep tests at 800 F and 1000 F show that the SPF processed material displays superior creep resistance compared with the as-received material. A post-SPF duplex-anneal heat treatment had no beneficial effect on tensile and creep properties

Obesity and Stroke: Does the Paradox Apply for Stroke?

Historically, obesity has been identified as one of the most important risk factors for developing cardiovascular diseases including stroke; however, a theory called “The Obesity Paradox” has been recently considered. The paradoxical theory is that obese or overweight patients (according to body mass index score) can have better outcomes compared to leaner or malnourished patients. The paradox was initially discovered in patients with heart failure. The purpose of this manuscript was to investigate whether this paradox also applies to stroke patients, according to information available in the current literature

Factores asociados a la elección de carrera y universidad

RESUMEN: Con el fin de identificar factores asociados a la elección de carrera y universidad, se realizó un estudio, mediante una encuesta, a los estudiantes de undécimo grado de establecimientos educativos ubicados en la zona urbana de los municipios de Santas Bárbara, La Pintada, Fredonia y Barbosa en el departamento de Antioquia. Los resultados muestran que el 28% de los estudiantes se inclinan por carreras del área de salud tales como medicina, veterinaria, enfermería y odontología. Además, se detectó que en la elección del estudiante ejercen influencia los padres, familiares más cercanos y amigos. Esta influencia se ejerce, muchas veces, de manera indirecta, ya que tanto los padres como los hijos no reconocen conscientemente la influencia que está en juego. Por otro lado, se halló que el 80% de los estudiantes prefieren estudiar en las universidades públicas como la Universidad de Antioquia y la Universidad Nacional, pues consideran que "son favorables económicamente" y "tienen calidad académica”. El proceso de elección de carrera y universidad, al margen de los determinantes externos, se encuentra regulado por las elecciones particulares de cada individuo, las cuales se reflejan en los imaginarios en los que basa el estudiante para hacer su elección

Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

Silk® Flow Diverter Device for Intracranial Aneurysm Treatment: A Systematic Review and Meta-Analysis

Flow diverters have become a critical instrument for complex aneurysms treatment. However, limited data are currently available regarding short and long-term outcomes for the Silk flow diverter. The objective of the study is to determine neurological prognosis and mortality rates for the Silk flow diversion device used in intracranial aneurysms. A systematic review with meta-analysis was performed using databases. The following descriptors were used for the search: “SILK”, “Flow Diverter”, “Mortality”, and “Prognosis”. The following data were extracted: mortality, good functional outcome, Glasgow outcome scale, complete or near-complete occlusion rates, rate of retreatment, and complications (thromboembolic and hemorrhagic complications). A total of 14 studies were selected. Among the 14 studies, 13 were retrospective observational cohort studies and 1 was a prospective observational cohort study. The mortality rate was 2.84%. The clinical good outcomes rate was 93.3%. The poor outcome rate was 6.6%. The overall thromboembolic complication rate was 6.06% (95% confidence interval [CI] 0.00–6.37, P=0.12, I2=3.13%). The total hemorrhagic complication rate was 1.62% (95% CI 0.00–5.34, P=0.28, I2=1.56%). The complete aneurysm occlusion rate was 80.4% (95% CI 8.65–9.38, P<0.0001, I2=9.09%). The Silk diverter device has a good safety and efficacy profile for treating intracranial aneurysms with high complete occlusion rates

Expression quantitative trait locus fine mapping of the 17q12–21 asthma locus in African American children: a genetic association and gene expression study

BackgroundAfrican ancestry is associated with a higher prevalence and greater severity of asthma than European ancestries, yet genetic studies of the most common locus associated with childhood-onset asthma, 17q12-21, in African Americans have been inconclusive. The aim of this study was to leverage both the phenotyping of the Children's Respiratory and Environmental Workgroup (CREW) birth cohort consortium, and the reduced linkage disequilibrium in African Americans, to fine map the 17q12-21 locus.MethodsWe first did a genetic association study and meta-analysis using 17q12-21 tag single-nucleotide polymorphisms (SNPs) for childhood-onset asthma in 1613 European American and 870 African American children from the CREW consortium. Nine tag SNPs were selected based on linkage disequilibrium patterns at 17q12-21 and their association with asthma, considering the effect allele under an additive model (0, 1, or 2 effect alleles). Results were meta-analysed with publicly available summary data from the EVE consortium (on 4303 European American and 3034 African American individuals) for seven of the nine SNPs of interest. Subsequently, we tested for expression quantitative trait loci (eQTLs) among the SNPs associated with childhood-onset asthma and the expression of 17q12-21 genes in resting peripheral blood mononuclear cells (PBMCs) from 85 African American CREW children and in upper airway epithelial cells from 246 African American CREW children; and in lower airway epithelial cells from 44 European American and 72 African American adults from a case-control study of asthma genetic risk in Chicago (IL, USA).Findings17q12-21 SNPs were broadly associated with asthma in European Americans. Only two SNPs (rs2305480 in gasdermin-B [GSDMB] and rs8076131 in ORMDL sphingolipid biosynthesis regulator 3 [ORMDL3]) were associated with asthma in African Americans, at a Bonferroni-corrected threshold of p&lt;0·0055 (for rs2305480_G, odds ratio [OR] 1·36 [95% CI 1·12-1·65], p=0·0014; and for rs8076131_A, OR 1·37 [1·13-1·67], p=0·0010). In upper airway epithelial cells from African American children, genotype at rs2305480 was the most significant eQTL for GSDMB (eQTL effect size [β] 1·35 [95% CI 1·25-1·46], p&lt;0·0001), and to a lesser extent showed an eQTL effect for post-GPI attachment to proteins phospholipase 3 (β 1·15 [1·08-1·22], p&lt;0·0001). No SNPs were eQTLs for ORMDL3. By contrast, in PBMCs, the five core SNPs were associated only with expression of GSDMB and ORMDL3. Genotype at rs12936231 (in zona pellucida binding protein 2) showed the strongest associations across both genes (for GSDMB, eQTLβ 1·24 [1·15-1·32], p&lt;0·0001; and for ORMDL3 (β 1·19 [1·12-1·24], p&lt;0·0001). The eQTL effects of rs2305480 on GSDMB expression were replicated in lower airway cells from African American adults (β 1·29 [1·15-1·44], p&lt;0·0001).InterpretationOur study suggests that SNPs regulating GSDMB expression in airway epithelial cells have a major role in childhood-onset asthma, whereas SNPs regulating the expression levels of 17q12-21 genes in resting blood cells are not central to asthma risk. Our genetic and gene expression data in African Americans and European Americans indicated GSDMB to be the leading candidate gene at this important asthma locus.FundingNational Institutes of Health, Office of the Director

The Effects of Cinacalcet in Older and Younger Patients on Hemodialysis: The Evaluation of Cinacalcet HCl Therapy to Lower Cardiovascular Events (EVOLVE) Trial.

This article contains supplemental material online at http://cjasn. asnjournals.org/lookup/suppl/doi:10.2215/CJN.07730814/-/ DCSupplemental.BACKGROUND AND OBJECTIVES: The calcimimetic cinacalcet reduced the risk of death or cardiovascular (CV) events in older, but not younger, patients with moderate to severe secondary hyperparathyroidism (HPT) who were receiving hemodialysis. To determine whether the lower risk in younger patients might be due to lower baseline CV risk and more frequent use of cointerventions that reduce parathyroid hormone (kidney transplantation, parathyroidectomy, and commercial cinacalcet use), this study examined the effects of cinacalcet in older (≥65 years, n=1005) and younger (3-fold higher in younger relative to older patients and were more frequent in patients randomized to placebo. In older patients, the adjusted relative hazard (95% confidence interval) for the primary composite (CV) end point (cinacalcet versus placebo) was 0.70 (0.60 to 0.81); in younger patients, the relative hazard was 0.97 (0.86 to 1.09). Corresponding adjusted relative hazards for mortality were 0.68 (0.51 to 0.81) and 0.99 (0.86 to 1.13). Reduction in the risk of severe unremitting HPT was similar in both groups. CONCLUSIONS: In the EVOLVE trial, cinacalcet decreased the risk of death and of major CV events in older, but not younger, patients with moderate to severe HPT who were receiving hemodialysis. Effect modification by age may be partly explained by differences in underlying CV risk and differential application of cointerventions that reduce parathyroid hormone.The Evaluation of Cinacalcet HCl Therapy to Lower Cardiovascular Events (EVOLVE) trial was funded by Amgen