Abstract The sex difference in perinatal mortality in developed countries is largely unexplained. The current study evaluated the differences in the impact of maternal smoking during pregnancy on the risk of perinatal death between males and females. The analysis involved 11,469 and 9,404 newborns derived from two population‐based birth cohorts in Northern Finland, for 1966 and 1985–86, respectively. The perinatal mortality rate was 23 per thousand in the 1966 cohort and 9 per thousand in the 1985–86 cohort. The rate ratio (RR) for mortality for males over females is 1.15 and 1.60 in the two cohorts, respectively. Among children whose mothers smoked during pregnancy, the RR was 2.2 (95% CI 1.0, 4.7) for the former cohort and 4.8 (95% CI 1.5, 15.2) for the later cohort; and among the children whose mothers did not smoke the corresponding RR was 1.2 (95% CI 0.9, 1.6) and 1.1 (95% CI 0.6, 1.9). Maternal smoking during pregnancy could be an important determinant accounting for the excess perinatal death for males over females. Our results encourage evaluation of the findings among other populations.
This paper presents a facile synthesis of single-crystalline Au nanowires by reduction of HAuCl4 in oleic acid and oleylamine. The diameter of these micron-meter-long Au nanowires is controlled to be 3 and 9 nm by volume ratio of oleylamine and oleic acid. When linked between two gold electrodes, the 9 nm Au nanowire shows good electron conductivity with its breakdown current density reaching 3.5 x 10(12) A/m2. This demonstrates that the chemically made ultrathin Au nanowires can be used as a molecular-scale interconnect for nanoelectronic applications.
Numerical results have been obtained for the plastic flow of a metal matrix composite material reinforced by rigid spheres, cylinders and ellipsoids. Align
The assignment of boundary values for the chemical potential and the calculation of energy‐release rates for the growth of creep cavities along grain boundaries by self‐diffusion are discussed. For simplicity, it is assumed that the boundaries are flat and that surface and grain‐boundary diffusion are the dominant transport mechanisms. As matter diffuses from the void surface into and along the grain boundary, misfit residual stresses are induced to alleviate the high stress concentration ahead of the cavity apex. As a result, the contribution of strain‐energy terms to the chemical potential can be neglected in typical cases. Also, contrary to the Griffith crack‐extension model, the energy dissipation incurred by diffusive removal of material from the cavity surface and deposition in the grain boundary is a major term in the energy transfers associated with cavity growth. The primary energy “sink” in diffusive cavity growth is shown to arise from the work done by the grain‐boundary normal stress when matter is inserted in the near‐tip region by diffusion, not from the loss of strain energy of matter that is removed from the cavity at its tip or from the work of bond separation. Thermodynamic restrictions on the angle formed by the void surfaces at their apex, where they join the grain boundary, are considered. Boundary values for the chemical potential are derived in a manner appropriate for arbitrarily large but elastic distortions of material near the cavity tip and, in contrast to most previous work in the area, the effects of surface tension (i.e. of “surface stress,” as distinct from surface energy) are included.
Field and laboratory observations show that shear deformation is often extremely localized at seismic slip rates, with a typical deforming zone width on the order of a few tens of microns. This extreme localization can be understood in terms of thermally driven weakening mechanisms. A zone of initially high strain rate will experience more shear heating and thus weaken faster, making it more likely to accommodate subsequent deformation. Fault zones often contain thermally unstable minerals such as clays or carbonates, which devolatilize at the high temperatures attained during seismic slip. In this paper, we investigate how these thermal decomposition reactions drive strain localization when coupled to a model for thermal pressurization of in situ groundwater. Building on Rice et al. (2014), we use a linear stability analysis to predict a localized zone thickness that depends on a combination of hydraulic, frictional, and thermochemical properties of the deforming fault rock. Numerical simulations show that the onset of thermal decomposition drives additional strain localization when compared with thermal pressurization alone and predict localized zone thicknesses of ∼7 and ∼13 μm for lizardite and calcite, respectively. Finally we show how thermal diffusion and the endothermic reaction combine to limit the peak temperature of the fault and that the pore fluid released by the reaction provides additional weakening of ∼20–40% of the initial strength.
This paper describes the use of micromolding in capillaries (MIMIC) to produce complex polymeric microstructures supported on different substrates and the applications of these microstructures in microfabrication. Patterned microstructures of several organic polymerspolyurethane, polyacrylate, and epoxywere formed by molding in enclosed, continuous channels formed by conformal contact between a solid support and an elastomeric mold whose surface had been patterned with a relief structure having micrometer-scale dimensions. A liquid prepolymer filled these channels by capillary action and was allowed to cure photochemically or thermally. The mold was then removed. Polymeric microstructures formed on films of Saran Wrap could be folded into different shapes, while these microstructures retained their forms; they could also be stretched uniaxially to generate microstructures having distorted forms. The patterned polymeric microstructures formed on SiO2, glass, and metals (Au, Ag, and Cr) could be used directly as resists in the selective etching of underlying substrates. Free-standing polymeric microstructures fabricated by lift-off were used as disposable masks to generate patterned microfeatures of metals on the surfaces of both planar and nonplanar substrates in two different procedures: (a) evaporation of gold through the polymeric mask supported on a substrate; (b) formation of patterned self-assembled monolayers (SAMs) by exposure of a silver film covered by a polymeric mask to hexadecanethiol (HDT) in vapor, followed by selective etching of the regions that were not exposed to HDT (that is, the parts of the surface protected by the mask) in an aqueous solution containing K2S2O3 and K3Fe(CN)6/K4Fe(CN)6.
The global obesity and diet-related chronic disease epidemics as well as the food production system’s environmental impacts are serious threats to human and planetary health that will continue to increase if no action is taken. Fortunately, dietary modifications can improve population health and sustainability simultaneously. Healthy dietary patterns (generally higher in plant-based foods, such as vegetables, fruits, whole grains and nuts) can reduce risk of obesity, type 2 diabetes and cardiovascular disease and are more sustainable than animal-based dietary patterns. Compared to plant-based foods, components of animal-based diets such as red and processed meat not only have a larger environmental impact but also have been associated with increased risk of chronic diseases and premature death. To alleviate the growing diet-related disease epidemics and future environmental crises and to shift populations towards dietary patterns higher in healthy plant-based foods and lower in animal-based foods, global interventions and policy changes are crucial.
No abstract is provided for this article.
In this chapter, we describe software that analyzes multilayers that are at steady-state conditions with respect to time; in order to be applicable, the multilayers’ width must be much larger than the total stack thickness, such that one can neglect lateral gradients in the direction of the layers. The software can be used to determine the temperature distribution in the layers, the deformation (elongation and stretch) and stress distribution in the layers of the multilayer, or any submultilayers formed by delamination cracks. The software is based on one-dimensional heat transfer described in Section 2.6 and general multilayer mechanics framework outlined in Chapter 5. The software is applicable to any number of layers, and using this framework, the results can be used to compute the energy release rates for semi-infinite delamination cracks located at any location in the stack. The code associated with this chapter has been dubbed LayerSlayer (LS).
