7,586 research outputs found
Absence of a local rest frame in far from equilibrium quantum matter
In a collision of strongly coupled quantum matter we find that the dynamics
of the collision produces regions where a local rest frame cannot be defined
because the energy-momentum tensor does not have a real time-like eigenvector.
This effect is purely quantum mechanical, since for classical systems, a local
rest frame can always be defined. We study the relation with the null and weak
energy condition, which are violated in even larger regions, and compare with
previously known examples. While no pathologies or instabilities arise, it is
interesting that regions without a rest frame are possibly present in heavy ion
collisions.Comment: 5 pages, 4 figures; v2: fixed typo, v3: added references, matches
published versio
Annexin A5 Inhibits Myocardial Inflammation and Improves Cardiac Function during Endotoxemia in Mice
Sepsis is a complex clinical syndrome that results from a harmful or damaging
host response to infection. Sepsis is characterized by the production of proinflammatory
cytokines like TNF-a and IL-ip, which have been shown to contribute to cardiovascular
dysfunction. Annexin A5 is a phospholipid binding protein that has been shown to have
anti-inflammatory, anti-apoptotic and anti-coagulant properties. However, its effect on
cardiac function during sepsis has not been established. This thesis investigated the
effect of annexin A5 on myocardial cytokine production and cardiac function during
endotoxemia in mice. It was found that annexin A5 treatment at the onset of
endotoxemia abrogated TNF-a and IL-1P production and prevented cardiac dysfunction.
Annexin A5 likely interacts with cell-surface receptor TLR4 to inhibit myocardial
cytokine expression to protect against cardiac dysfunction during endotoxemia. These
results suggest that annexin A5 provides a novel protective role in the heart during
t
endotoxemia
Central Venous Catheter Complications during Home Parenteral Nutrition: A Prospective Pilot Study of 481 Patients with More than 30,000 Catheter Days
Background: Home parenteral nutrition (HPN) has been shown to delay deterioration in cancer patients with malnutrition. Its risk-benefit ratio, however, is determined by the threat of central venous catheter (CVC) complications. Only few prospective studies on this subject exist, most of them based on small samples. The objective of this study was to provide reliable estimates of incidence rates of CVC complications in everyday HPN patient care in Germany. Patients and Methods: Aiming for a large prospective cohort study, we cooperated with a service provider caring for HPN patients nationwide. Between July 1 and November 30, 2006, all consecutive adult patients with more than 10 infusion days and no previous history of HPN were recruited. Follow-up ended on January 31, 2007. Data were collected in a standardised way by the provider's staff. To prevent underreporting, we used computer-assisted telephone interviews with medical caregivers as a provider-independent data source. Results: 481 patients met the inclusion criteria, contributing a total of 31,337 catheter days. 52 patients experienced a total of 63 CVC complications, resulting in an incidence rate of 2.01 CVC complications per 1,000 catheter days including 1.02 CVC infections per 1,000 catheter days. Conclusion: HPN administration can be safely performed with a relatively low rate of CVC complications
The combinatorics of open covers (II)
We continue to investigate various diagonalization properties for sequences
of open covers of separable metrizable spaces introduced in Part I. These
properties generalize classical ones of Rothberger, Menger, Hurewicz, and
Gerlits-Nagy. In particular, we show that most of the properties introduced in
Part I are indeed distinct. We characterize two of the new properties by
showing that they are equivalent to saying all finite powers have one of the
classical properties above (Hurewicz property in one case and in the Menger
property in other). We consider for each property the smallest cardinality of
metric space which fails to have that property. In each case this cardinal
turns out to equal another well-known cardinal less than the continuum. We also
disprove (in ZFC) a conjecture of Hurewicz which is analogous to the Borel
conjecture. Finally, we answer several questions from Part I concerning
partition properties of covers
Laser cooling with a single laser beam and a planar diffractor
A planar triplet of diffraction gratings is used to transform a single laser
beam into a four-beam tetrahedral magneto-optical trap. This `flat' pyramid
diffractor geometry is ideal for future microfabrication. We demonstrate the
technique by trapping and subsequently sub-Doppler cooling 87Rb atoms to
30microKelvin.Comment: 3 pages, 4 figure
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