1,124 research outputs found
Patient Safety and the COVID-19 Pandemic in Germany: A Repeated Population-Based Cross-Sectional Survey.
The coronavirus (COVID-19) has presented Germany with major challenges and has led to concerns about patient safety. We conducted an observational, population-based, nationwide, repeated cross-sectional survey on patient safety in Germany in 2019, 2020, and 2021. Each of the three samples consisted of 1000 randomly recruited adults. Self-reported data via computer-assisted telephone interviews were taken from TK Monitor of Patient Safety. Perceptions, experience, and knowledge relating to patient safety were assessed. The majority of respondents considered medical treatment to involve risks to patient safety. This proportion decreased during the pandemic. The majority also had a high degree of self-efficacy regarding the prevention of medical errors, whereby the percentage that felt well informed with regard to patient safety rose throughout the pandemic. The proportion of persons that suspected they had in the past experienced an error in their treatment remained steady at one third as well as the reported errors. In 2020, 65% of respondents thought health communication with service providers (e.g., extent and comprehensibility of information) remained unchanged during the pandemic, while 35% reported that medical appointments had been cancelled or postponed. This study is the first to assess patient safety from a general population perspective during the coronavirus pandemic in Germany. COVID-19 had a positive impact on perceived patient safety but no impact on suspected and reported errors. Self-efficacy with regard to medical error prevention steadily increased in the general population, and people considered themselves well informed
Does entanglement depend on the timing of the impacts at the beam-splitters?
A new nonlocality experiment with moving beam-splitters is proposed. The
experiment is analysed according to conventional quantum mechanics, and to an
alternative nonlocal description in which superposition depends not only on
indistinguishability but also on the timing of the impacts at the
beam-splitters.Comment: 5 pages of Latex and 2 eps figures. Submitted to Phys. Lett.
Aptamer BC 007âs Affinity to Specific and Less-Specific Anti-SARS-CoV-2 Neutralizing Antibodies
COVID-19 is a pandemic respiratory disease that is caused by the highly infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Anti-SARS-CoV-2 antibodies are essential weapons that a patient with COVID-19 has to combat the disease. When now repurposing a drug, namely an aptamer that interacts with SARS-CoV-2 proteins for COVID-19 treatment (BC 007), which is, however, a neutralizer of pathogenic autoantibodies in its original indication, the possibility of also binding and neutralizing anti-SARS-CoV-2 antibodies must be considered. Here, the highly specific virus-neutralizing antibodies have to be distinguished from the ones that also show cross-reactivity to tissues. The last-mentioned could be the origin of the widely reported SARS-CoV-2-induced autoimmunity, which should also become a target of therapy. We, therefore, used enzyme-linked immunosorbent assay (ELISA) technology to assess the binding of well-characterized publicly accessible anti-SARS-CoV-2 antibodies (CV07-209 and CV07-270) with BC 007. Nuclear magnetic resonance spectroscopy, isothermal calorimetric titration, and circular dichroism spectroscopy were additionally used to test the binding of BC 007 to DNA-binding sequence segments of these antibodies. BC 007 did not bind to the highly specific neutralizing anti-SARS-CoV-2 antibody but did bind to the less specific one. This, however, was a lot less compared to an autoantibody of its original indication (14.2%, range 11.0â21.5%). It was also interesting to see that the less-specific anti-SARS-CoV-2 antibody also showed a high background signal in the ELISA (binding on NeutrAvidin-coated or activated but noncoated plastic plate). These initial experiments suggest that the risk of binding and neutralizing highly specific anti-SARS CoV-2 antibodies by BC 007 should be low.Transfer-BonunsPeer Reviewe
From classical to modern ether-drift experiments: the narrow window for a preferred frame
Modern ether-drift experiments look for a preferred frame by measuring the
difference \Delta \nu in the relative frequencies of two cavity-stabilized
lasers, upon local rotations of the apparatus or under the Earth's rotation. If
the small deviations observed in the classical ether-drift experiments were not
mere instrumental artifacts, by replacing the high vacuum in the resonating
cavities with a dielectric gaseous medium (e.g. air), the typical measured
\Delta\nu\sim 1 Hz should increase by orders of magnitude. This prediction is
consistent with the characteristic modulation of a few kHz observed in the
original experiment with He-Ne masers. However, if such enhancement would not
be confirmed by new and more precise data, the existence of a preferred frame
can be definitely ruled out.Comment: 15 pages, Latex fil
Neutron beta decay in effective field theory
Radiative corrections to the lifetime and angular correlation coefficients of
neutron beta-decay are evaluated in effecitive field theory. We also evaluate
the lowest order nucleon recoil corrections, including weak-magnetism. Our
results agree with those of the long-range and model-independent part of
previous calculations. In an effective theory the model-dependent radiative
corrections are replaced by well-defined low-energy constants. The effective
field theory allows a systematic evaluation of higher order corrections to our
results to the extent that the relevant low-energy constants are known.Comment: 13 pages, 1 figure; two references added, minor correctio
A derivation of quantum theory from physical requirements
Quantum theory is usually formulated in terms of abstract mathematical
postulates, involving Hilbert spaces, state vectors, and unitary operators. In
this work, we show that the full formalism of quantum theory can instead be
derived from five simple physical requirements, based on elementary assumptions
about preparation, transformations and measurements. This is more similar to
the usual formulation of special relativity, where two simple physical
requirements -- the principles of relativity and light speed invariance -- are
used to derive the mathematical structure of Minkowski space-time. Our
derivation provides insights into the physical origin of the structure of
quantum state spaces (including a group-theoretic explanation of the Bloch ball
and its three-dimensionality), and it suggests several natural possibilities to
construct consistent modifications of quantum theory.Comment: 16 pages, 2 figures. V3: added alternative formulation of Requirement
5, extended abstract, some minor modification
Quantum measurement occurrence is undecidable
In this work, we show that very natural, apparently simple problems in
quantum measurement theory can be undecidable even if their classical analogues
are decidable. Undecidability hence appears as a genuine quantum property here.
Formally, an undecidable problem is a decision problem for which one cannot
construct a single algorithm that will always provide a correct answer in
finite time. The problem we consider is to determine whether sequentially used
identical Stern-Gerlach-type measurement devices, giving rise to a tree of
possible outcomes, have outcomes that never occur. Finally, we point out
implications for measurement-based quantum computing and studies of quantum
many-body models and suggest that a plethora of problems may indeed be
undecidable.Comment: 4+ pages, 1 figure, added a proof that the QMOP is still undecidable
for exponentially small but nonzero probabilit
Three-dimensionality of space and the quantum bit: an information-theoretic approach
It is sometimes pointed out as a curiosity that the state space of quantum
two-level systems, i.e. the qubit, and actual physical space are both
three-dimensional and Euclidean. In this paper, we suggest an
information-theoretic analysis of this relationship, by proving a particular
mathematical result: suppose that physics takes place in d spatial dimensions,
and that some events happen probabilistically (not assuming quantum theory in
any way). Furthermore, suppose there are systems that carry "minimal amounts of
direction information", interacting via some continuous reversible time
evolution. We prove that this uniquely determines spatial dimension d=3 and
quantum theory on two qubits (including entanglement and unitary time
evolution), and that it allows observers to infer local spatial geometry from
probability measurements.Comment: 13 + 22 pages, 9 figures. v4: some clarifications, in particular in
Section V / Appendix C (added Example 39
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