8,565 research outputs found
Managing Opioid-Tolerant Patients in the Perioperative Surgical Home.
Management of acute postoperative pain is important to decrease perioperative morbidity and improve patient satisfaction. Opioids are associated with potential adverse events that may lead to significant risk. Uncontrolled pain is a risk factor in the transformation of acute pain to chronic pain. Balancing these issues can be especially challenging in opioid-tolerant patients undergoing surgery, for whom rapidly escalating opioid doses in an effort to control pain can be associated with increased complications. In the perioperative surgical home model, anesthesiologists are positioned to coordinate a comprehensive perioperative analgesic plan that begins with the preoperative assessment and continues through discharge
Isolation and characterisation of 17 microsatellite loci for the red-billed chough (Pyrrhocorax pyrrhocorax)
Peer reviewedPostprin
Effects of Circulating and Local Uteroplacental Angiotensin II in Rat Pregnancy.
The renin-angiotensin (Ang) system is important during placental development. Dysregulation of the renin-Ang system is important in preeclampsia (PE). Female rats transgenic for the human angiotensinogen gene crossed with males transgenic for the human renin gene develop the PE syndrome, whereas those of the opposite cross do not. We used this model to study the role of Ang II in trophoblast invasion, which is shallow in human PE but deeper in this model. We investigated the following groups: PE rats, opposite-cross rats, Ang II–infused rats (1000 ng/kg per day), and control rats. Ang II infusion increased only circulating Ang II levels (267.82 pg/mL), opposite cross influenced only uteroplacental Ang II (13.52 fmol/mg of protein), and PE increased both circulating (251.09 pg/mL) and uteroplacental (19.24 fmol/mg of protein) Ang II. Blood pressure and albuminuria occurred in the models with high circulating Ang II but not in the other models. Trophoblast invasion increased in PE and opposite-cross rats but not in Ang II–infused rats. Correspondingly, uterine artery resistance index increased in Ang II–infused rats but decreased in PE rats. We then studied human trophoblasts and villous explants from first-trimester pregnancies with time-lapse microscopy. Local Ang II dose-dependently increased migration by 75%, invasion by 58%, and motility by 282%. The data suggest that local tissue Ang II stimulates trophoblast invasion in vivo in the rat and in vitro in human cells, a hitherto fore unrecognized function. Conceivably, upregulation of tissue Ang II in the maternal part of the placenta represents an important growth factor for trophoblast invasion and migration
Two-particle decay and quantum criticality in dimerized antiferromagnets
In certain Mott-insulating dimerized antiferromagnets, triplet excitations of
the paramagnetic phase can decay into the two-particle continuum. When such a
magnet undergoes a quantum phase transition into a magnetically ordered state,
this coupling becomes part of the critical theory provided that the lattice
ordering wavevector is zero. One microscopic example is the staggered-dimer
antiferromagnet on the square lattice, for which deviations from O(3)
universality have been reported in numerical studies. Using both symmetry
arguments and microscopic calculations, we show that a non-trivial cubic term
arises in the relevant order-parameter quantum field theory, and assess its
consequences using a combination of analytical and numerical methods. We also
present finite-temperature quantum Monte Carlo data for the staggered-dimer
antiferromagnet which complement recently published results. The data can be
consistently interpreted in terms of critical exponents identical to that of
the standard O(3) universality class, but with anomalously large corrections to
scaling. We argue that the two-particle decay of critical triplons, although
irrelevant in two spatial dimensions, is responsible for the leading
corrections to scaling due to its small scaling dimension.Comment: 14 pages, 7 fig
Block-Spin Approach to Electron Correlations
We consider an expansion of the ground state wavefunction of quantum lattice
many-body systems in a basis whose states are tensor products of block-spin
wavefunctions. We demonstrate by applying the method to the antiferromagnetic
spin-1/2 chain that by selecting the most important many-body states the
technique affords a severe truncation of the Hilbert space while maintaining
high accuracy.Comment: 17 pages, 3 Postscript figure
Complementary stereotyping of ethnic minorities predicts system justification in Poland
We investigate the phenomenon of complementary stereotyping of ethnic minorities in Poland and its relationship to system justification. Using results from a nationally representative survey we test the hypothesis that complementary stereotypes—according to which ethnic minorities are seen as possessing distinctive, offsetting strengths and weaknesses—would be associated with system justification among Polish majority citizens. For four minorities, results indicated that stereotyping them as (a) low in morality but high in competence or (b) high in morality but low in competence predicted greater system justification. These results suggest that even in a context that is low in support for the status quo, complementary stereotyping of ethnic minorities is linked to system justification processes. For the three minority groups that were lowest in social status, complementary stereotyping was unrelated to system justification. It appears that negative attitude towards these groups can be expressed openly, regardless of one’s degree of system justification
Emergence of chaotic scattering in ultracold Er and Dy
We show that for ultracold magnetic lanthanide atoms chaotic scattering
emerges due to a combination of anisotropic interaction potentials and Zeeman
coupling under an external magnetic field. This scattering is studied in a
collaborative experimental and theoretical effort for both dysprosium and
erbium. We present extensive atom-loss measurements of their dense magnetic
Feshbach resonance spectra, analyze their statistical properties, and compare
to predictions from a random-matrix-theory inspired model. Furthermore,
theoretical coupled-channels simulations of the anisotropic molecular
Hamiltonian at zero magnetic field show that weakly-bound, near threshold
diatomic levels form overlapping, uncoupled chaotic series that when combined
are randomly distributed. The Zeeman interaction shifts and couples these
levels, leading to a Feshbach spectrum of zero-energy bound states with
nearest-neighbor spacings that changes from randomly to chaotically distributed
for increasing magnetic field. Finally, we show that the extreme temperature
sensitivity of a small, but sizeable fraction of the resonances in the Dy and
Er atom-loss spectra is due to resonant non-zero partial-wave collisions. Our
threshold analysis for these resonances indicates a large collision-energy
dependence of the three-body recombination rate
Numerical study of the one-dimensional quantum compass model
The ground state magnetic phase diagram of the one-dimensional quantum
compass model (QCM) is studied using the numerical Lanczos method. A detailed
numerical analysis of the low energy excitation spectrum is presented. The
energy gap and the spin-spin correlation functions are calculated for finite
chains. Two kind of the magnetic long-range orders, the Neel and a type of the
stripe-antiferromagnet, in the ground state phase diagram are identified. Based
on the numerical analysis, the first and second order quantum phase transitions
in the ground state phase diagram are identified.Comment: 6 pages, 8 figures. arXiv admin note: text overlap with
arXiv:1105.211
Interaction induced collapse of a section of the Fermi sea in in the zig-zag Hubbard ladder
Using the next-nearest neighbor (zig-zag) Hubbard chain as an one
dimemensional model, we investigate the influence of interactions on the
position of the Fermi wavevectors with the density-matrix renormalization-group
technique (DMRG). For suitable choices of the hopping parameters we observe
that electron-electron correlations induce very different renormalizations for
the two different Fermi wavevectors, which ultimately lead to a complete
destruction of one section of the Fermi sea in a quantum critical point
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