85 research outputs found
Acrylamide: Increased concentrations in homemade food and first evidence of its variable absorption from food, variable metabolism and placental and breast milk transfer in humans
We have developed a liquid chromatography/mass spectrometry (LC-MS/MS) assay to determine acrylamide in various body fluids. The assay also allows the reliable quantitation of acrylamide in food. In a total of 11 healthy male and female subjects, we were able to show that acrylamide from food given to humans is in fact absorbed from the gut. The half-lives determined in two male subjects were 2.2 and 7 h. Acrylamide was found in human breast milk and penetrated the human placenta (n = 3). The variability of acrylamide concentrations found in this investigation is most likely caused by variable intersubject bioavailability and metabolism. This may be an important indication that the assessment of the risk from acrylamide for the individual may be very difficult without knowing the concentrations of acrylamide in the body. This should be considered in the design of any risk assessment study or post hoc analysis of earlier studies. At this time, we suggest that pregnant women and breast-feeding mothers avoid acrylamide-containing food. Copyright (C) 2002 S. Karger AG, Basel
Mean-field Study of Charge, Spin, and Orbital Orderings in Triangular-lattice Compounds ANiO2 (A=Na, Li, Ag)
We present our theoretical results on the ground states in layered
triangular-lattice compounds ANiO2 (A=Na, Li, Ag). To describe the interplay
between charge, spin, orbital, and lattice degrees of freedom in these
materials, we study a doubly-degenerate Hubbard model with electron-phonon
couplings by the Hartree-Fock approximation combined with the adiabatic
approximation. In a weakly-correlated region, we find a metallic state
accompanied by \sqroot3x\sqroot3 charge ordering. On the other hand, we obtain
an insulating phase with spin-ferro and orbital-ferro ordering in a wide range
from intermediate to strong correlation. These phases share many
characteristics with the low-temperature states of AgNiO2 and NaNiO2,
respectively. The charge-ordered metallic phase is stabilized by a compromise
between Coulomb repulsions and effective attractive interactions originating
from the breathing-type electronphonon coupling as well as the Hund's-rule
coupling. The spin-orbital-ordered insulating phase is stabilized by the
cooperative effect of electron correlations and the Jahn-Teller coupling, while
the Hund's-rule coupling also plays a role in the competition with other
orbital-ordered phases. The results suggest a unified way of understanding a
variety of low-temperature phases in ANiO2. We also discuss a keen competition
among different spin-orbital-ordered phases in relation to a puzzling behavior
observed in LiNiO2
Interplay between localized and itinerant d electrons in a frustrated metallic antiferromagnet, 2H-AgNiO2
We report the electronic and magnetic behaviour of the frustrated triangular
metallic antiferromagnet 2H-AgNiO2 in high magnetic fields (54 T) using
thermodynamic and transport measurements. Here localized d electrons are
arranged on an antiferromagnetic triangular lattice nested inside a honeycomb
lattice with itinerant d electrons. When the magnetic field is along the easy
axis we observe a cascade of field-induced transitions, attributed to the
competition between easy-axis anisotropy, geometrical frustration and coupling
of the localized and itinerant system. The quantum oscillations data suggest
that the Fermi surface is reconstructed by the magnetic order but in high
fields magnetic breakdown orbits are possible. The itinerant electrons are
extremely sensitive to scattering by spin fluctuations and a significant mass
enhancement (~ 3) is found.Comment: 4 page
Recovery of cefazolin and clindamycin in in vitro pediatric CPB systems
Cardiopulmonary bypass (CPB) is often necessary for congenital cardiac surgery, but CPB can alter drug pharmacokinetic parameters resulting in underdosing. Inadequate plasma levels of antibiotics could lead to postoperative infections with increased morbidity. The influence of pediatric CPB systems on cefazolin and clindamycin plasma levels is not kn
In Vitro Recovery of Sufentanil, Midazolam, Propofol, and Methylprednisolone in Pediatric Cardiopulmonary Bypass Systems
Objectives: To evaluate in vitro drug recovery in cardiopulmonary bypass (CPB) systems used for pediatric cardiac surgery. Design: Observational in vitro study. Setting: Single-center university hospital. Participants: In vitro CPB systems used for pediatric cardiac surgery. Interventions: Three full neonatal, infant, and pediatric CPB systems were primed according to hospital protocol and kept running for 6 hours. Midazolam, propofol, sufentanil, and methylprednisolone were added to the venous side of the systems in doses commonly used for induction of general anesthesia. Blood samples were taken from the postoxygenator side of the circuit immediately after injection of the drugs and after 2, 5, 7, 10, 30, 60, 180, and 300 minutes. Measurements and Main Results: Linear mixed model analyses were performed to assess the relationship between log-transformed drug concentration (dependent variable) and type of CPB system and sample time point (independent variables). The mean percentage of drug recovery after 60 and 180 minutes compared with T1 was 41.7% (95% confidence interval [CI] 35.9-47.4) and 23.0% (95% CI 9.2-36.8) for sufentanil, 87.3% (95% CI 64.9-109.7) and 82.0% (95% CI 64.6-99.4) for midazolam, 41.3% (95% CI 15.5-67.2) and 25.0% (95% CI 4.7-45.3) for propofol, and 119.3% (95% CI 101.89-136.78) and 162.0% (95% CI 114.09-209.91) for methylprednisolone, respectively. Conclusions: The present in vitro experiment with neonatal, infant, and pediatric CPB systems shows a variable recovery of routinely used drugs with significant differences between drugs, but not between system categories (with the exception of propofol). The decreased recovery of mainly sufentanil and propofol could lead to suboptimal dosing of patients during cardiac surgery with CPB
Theater seit den 1990er Jahren
The volume addresses the return of the dramatist to the European theatre since the mid-1990s. Beginning with the British avant-garde of instantly written, aggressive “in-yer-face” dramatic texts by Sarah Kane and Mark Ravenhill text became again a theatrical force to count on as many young directors like Rene Pollesch also write their own plays. Global crises are discussed and address the pressing political issues of our time, although these texts lack direct political engagement. The act of instantaneous playwriting thus appears as an effort to decidedly construct reality as to affirm theatre’s social relevance in times of crisis. The volume presents articles by renowned theatre and drama scholars on the topic from a cross-cultural perspective
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