1,714 research outputs found
Properties of protective oxide scales containing cerium on Incoloy 800H in oxidizing and sulfidizing environments. I. Constant-extension-rate study of mechanical properties
The mechanical properties of ceramic coatings containing cerium oxide, prepared by the sol-gel method and used to protect Incoloy 800H against aggressive environments, are reported. Deformation and cracking behavior in oxidizing and sulfidizing environments has been investigated by constant-extension-rate tests. Extension rates were between 9.3Ă10â6 and 3.7Ă10â7 secâ1 at 823 <T<973 K. Under these conditions, cerium oxide sol-gel-coated specimens do not show any failure at extensions of 1.0% or more, but in hydrogen, sulfide failure is found at lower extensions than in air
Functional consequences of sphingomyelinase-induced changes in erythrocyte membrane structure.
Inflammation enhances the secretion of sphingomyelinases (SMases). SMases catalyze the hydrolysis of sphingomyelin into phosphocholine and ceramide. In erythrocytes, ceramide formation leads to exposure of the removal signal phosphatidylserine (PS), creating a potential link between SMase activity and anemia of inflammation. Therefore, we studied the effects of SMase on various pathophysiologically relevant parameters of erythrocyte homeostasis. Time-lapse confocal microscopy revealed a SMase-induced transition from the discoid to a spherical shape, followed by PS exposure, and finally loss of cytoplasmic content. Also, SMase treatment resulted in ceramide-associated alterations in membrane-cytoskeleton interactions and membrane organization, including microdomain formation. Furthermore, we observed increases in membrane fragility, vesiculation and invagination, and large protein clusters. These changes were associated with enhanced erythrocyte retention in a spleen-mimicking model. Erythrocyte storage under blood bank conditions and during physiological aging increased the sensitivity to SMase. A low SMase activity already induced morphological and structural changes, demonstrating the potential of SMase to disturb erythrocyte homeostasis. Our analyses provide a comprehensive picture in which ceramide-induced changes in membrane microdomain organization disrupt the membrane-cytoskeleton interaction and membrane integrity, leading to vesiculation, reduced deformability, and finally loss of erythrocyte content. Understanding these processes is highly relevant for understanding anemia during chronic inflammation, especially in critically ill patients receiving blood transfusions
See the cake and have it too? Investigating the effect of watching a TV cooking show on unhealthy food choices
Contains fulltext :
233413.pdf (Publisherâs version ) (Open Access)This study tested whether exposure to food-related (vs. non-food related) TV content would increase unhealthy food choices in unsuccessful restrained eaters (i.e., chronic dieters with low perceived self-regulatory success; PSRS), decrease unhealthy food choices in successful restrained eaters (i.e., chronic dieters with high PSRS), and would not affect food choices in unrestrained eaters (i.e., non-dieters). As such, we attempted to (1) explain previous mixed findings on behavioral effects of exposure to food-related TV content, and (2) generalize previous findings on successful and unsuccessful restrained and unrestrained eaters' differential reactivity to isolated food cues (e.g., food words) to food cues embedded in TV content. In a one-factorial between-subjects experiment, participants viewed a cooking segment in which high-calorie cakes were prepared (n = 50) or a non-food segment (n = 62) of a TV show. The percentage of unhealthy (vs. healthy) food choices in a computerized choice task served as dependent variable. Eating restraint and PSRS were measured afterwards. In contrast to the hypothesis, no three-way interaction between TV content, eating restraint, and PSRS on the percentage of unhealthy food choices was found. However, it was found that overall, people with lower levels of PSRS made a higher percentage of unhealthy food choices compared to people with higher levels of PSRS. Contrasting findings from previous research using isolated food cues, this study showed no evidence of unsuccessful restrained eaters' heightened susceptibility to food cues in TV content, possibly explained by a lower salience of or attention to food cues.8 p
Postgraduate Coursework Studies handbook
2002 handbook for Postgraduate Coursework Studie
Evolution of E2 transition strength in deformed hafnium isotopes from new measurements on Hf, Hf, and Hf
The available data for E2 transition strengths in the region between
neutron-deficient Hf and Pt isotopes are far from complete. More and precise
data are needed to enhance the picture of structure evolution in this region
and to test state-of-the-art nuclear models. In a simple model, the maximum
collectivity is expected at the middle of the major shell. However, for actual
nuclei, this picture may no longer be the case, and one should use a more
realistic nuclear-structure model. We address this point by studying the
spectroscopy of Hf. We remeasure the 2^+_1 half-lives of 172,174,176Hf, for
which there is some disagreement in the literature. The main goal is to
measure, for the first time, the half-lives of higher-lying states of the
rotational band. The new results are compared to a theoretical calculation for
absolute transition strengths. The half-lives were measured using \gamma-\gamma
and conversion-electron-\gamma delayed coincidences with the fast timing
method. For the determination of half-lives in the picosecond region, the
generalized centroid difference method was applied. For the theoretical
calculation of the spectroscopic properties, the interacting boson model is
employed, whose Hamiltonian is determined based on microscopic energy-density
functional calculations. The measured 2^+_1 half-lives disagree with results
from earlier \gamma-\gamma fast timing measurements, but are in agreement with
data from Coulomb excitation experiments and other methods. Half-lives of the
4^+_1 and 6^+_1 states were measured, as well as a lower limit for the 8^+_1
states. We show the importance of the mass-dependence of effective boson charge
in the description of E2 transition rates in chains of nuclei. It encourages
further studies of the microscopic origin of this mass dependence. New data on
transition rates in nuclei from neighboring isotopic chains could support these
studies.Comment: 16 pages, 16 figures, 7 tables; Abstract shortened due to character
limi
On the Metric Dimension of Cartesian Products of Graphs
A set S of vertices in a graph G resolves G if every vertex is uniquely
determined by its vector of distances to the vertices in S. The metric
dimension of G is the minimum cardinality of a resolving set of G. This paper
studies the metric dimension of cartesian products G*H. We prove that the
metric dimension of G*G is tied in a strong sense to the minimum order of a
so-called doubly resolving set in G. Using bounds on the order of doubly
resolving sets, we establish bounds on G*H for many examples of G and H. One of
our main results is a family of graphs G with bounded metric dimension for
which the metric dimension of G*G is unbounded
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