82 research outputs found
Diffusive entanglement generation by continuous homodyne monitoring of spontaneous emission
We consider protocols to generate quantum entanglement between two remote
qubits, through joint time-continuous detection of their spontaneous emission.
We demonstrate that schemes based on homodyne detection, leading to diffusive
quantum trajectories, lead to identical average entanglement yield as
comparable photodetection strategies; this is despite substantial differences
in the two-qubit state dynamics between these schemes, which we explore in
detail. The ability to use different measurements to achieve the same ends may
be of practical significance; the less-well-known diffusive scheme appears far
more feasible on superconducting qubit platforms in the near term.Comment: 6 pages, 3 figures. Supplementary information can be found in the
longer version at arXiv:1910.0120
Towards an International Classification for Patient Safety: key concepts and terms
Background. Understanding the patient safety literature has been compromised by the inconsistent use of language.
Objectives. To identify key concepts of relevance to the International Patient Safety Classification (ICPS) proposed by the World Alliance For Patient Safety of the World Health Organization (WHO), and agree on definitions and preferred terms.
Methods. Six principles were agreed uponāthat the concepts and terms should: be applicable across the full spectrum of healthcare; be consistent with concepts from other WHO Classifications; have meanings as close as possible to those in colloquial use; convey the appropriate meanings with respect to patient safety; be brief and clear, without unnecessary or redundant qualifiers; be fit-for-purpose for the ICPS.
Results. Definitions and preferred terms were agreed for 48 concepts of relevance to the ICPS; these were described and the relationships between them and the ICPS were outlined.
Conclusions. The consistent use of key concepts, definitions and preferred terms should pave the way for better understanding, for comparisons between facilities and jurisdictions, and for trends to be tracked over time. Changes and improvements, translation into other languages and alignment with other sets of patient safety definitions will be necessary. This work represents the start of an ongoing process of progressively improving a common international understanding of terms and concepts relevant to patient safety.
Keywords: patient safety, definitions, concepts, terminology, classificatio
Temperature dependent resistivity of spin-split subbands in GaAs 2D hole system
We calculate the temperature dependent resistivity in spin-split subbands
induced by the inversion asymmetry of the confining potential in GaAs 2D hole
systems. By considering both temperature dependent multisubband screening of
impurity disorder and hole-hole scattering we find that the strength of the
metallic behavior depends on the symmetry of the confining potential (i.e.,
spin-splitting) over a large range of hole density. At low density above the
metal-insulator transition we find that effective disorder reduces the
enhancement of the metallic behavior induced by spin-splitting. Our theory is
in good qualitative agreement with existing experiments
Metallicity and its low temperature behavior in dilute 2D carrier systems
We theoretically consider the temperature and density dependent transport
properties of semiconductor-based 2D carrier systems within the RPA-Boltzmann
transport theory, taking into account realistic screened charged impurity
scattering in the semiconductor. We derive a leading behavior in the transport
property, which is exact in the strict 2D approximation and provides a zeroth
order explanation for the strength of metallicity in various 2D carrier
systems. By carefully comparing the calculated full nonlinear temperature
dependence of electronic resistivity at low temperatures with the corresponding
asymptotic analytic form obtained in the limit, both within the
RPA screened charged impurity scattering theory, we critically discuss the
applicability of the linear temperature dependent correction to the low
temperature resistivity in 2D semiconductor structures. We find quite generally
that for charged ionized impurity scattering screened by the electronic
dielectric function (within RPA or its suitable generalizations including local
field corrections), the resistivity obeys the asymptotic linear form only in
the extreme low temperature limit of . We point out the
experimental implications of our findings and discuss in the context of the
screening theory the relative strengths of metallicity in different 2D systems.Comment: We have substantially revised this paper by adding new materials and
figures including a detailed comparison to a recent experimen
The relative importance of electron-electron interactions compared to disorder in the two-dimensional "metallic" state
The effect of substrate bias and surface gate voltage on the low temperature
resistivity of a Si-MOSFET is studied for electron concentrations where the
resistivity increases with increasing temperature. This technique offers two
degrees of freedom for controlling the electron concentration and the device
mobility, thereby providing a means to evaluate the relative importance of
electron-electron interactions and disorder in this so-called ``metallic''
regime. For temperatures well below the Fermi temperature, the data obey a
scaling law where the disorder parameter (), and not the
concentration, appears explicitly. This suggests that interactions, although
present, do not alter the Fermi-liquid properties of the system fundamentally.
Furthermore, this experimental observation is reproduced in results of
calculations based on temperature-dependent screening, in the context of
Drude-Boltzmann theory.Comment: 5 pages, 6 figure
Invasive characteristics of human prostatic epithelial cells: understanding the metastatic process
Prostate cancer has a predilection to metastasise to the bone marrow stroma (BMS) by an as yet uncharacterised mechanism. We have defined a series of coculture models of invasion, which simulate the blood/BMS boundary and allow the elucidation of the signalling and mechanics of trans-endothelial migration within the complex bone marrow environment. Confocal microscopy shows that prostate epithelial cells bind specifically to bone marrow endothelial-to-endothelial cell junctions and initiate endothelial cell retraction. Trans-endothelial migration proceeds via an epithelial cell pseudopodial process, with complete epithelial migration occurring after 232Ā±43āmin. Stromal-derived factor-1 (SDF-1)/CXCR4 signalling induced PC-3 to invade across a basement membrane although the level of invasion was 3.5-fold less than invasion towards BMS (P=0.0007) or bone marrow endothelial cells (P=0.004). Maximal SDF-1 signalling of invasion was completely inhibited by 10āĪ¼M of the SDF-1 inhibitor T140. However, 10āĪ¼M T140 only reduced invasion towards BMS and bone marrow endothelial cells by 59% (P=0.001) and 29% (P=0.011), respectively. This study highlights the need to examine the potential roles of signalling molecules and/or inhibitors, not just in single-cell models but in coculture models that mimic the complex environment of the bone marrow
Clinical applications of donor lymphocyte infusion from an HLA-haploidentical donor: consensus recommendations from the Acute Leukemia Working Party of the EBMT
Donor lymphocyte infusion has been used in the management of relapsed hematologic malignancies after allogeneic hematopoietic cell transplantation. It can eradicate minimal residual disease or be used to rescue a hematologic relapse, being able to induce durable remissions in a subset of patients. With the increased use of haploidentical hematopoietic cell transplantation, there is renewed interest in the use of donor lymphocytes to either treat or prevent disease relapse post transplant. Published retrospective and small prospective studies have shown encouraging results with therapeutic donor lymphocyte infusion in different haploidentical transplantation platforms. In this consensus paper, finalized on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation, we summarize the available evidence on the use of donor lymphocyte infusion from haploidentical donor, and provide recommendations on its therapeutic, pre-emptive and prophylactic use in clinical practice
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