58 research outputs found
Test of a theoretical equation of state for elemental solids and liquids
We propose a means for constructing highly accurate equations of state (EOS)
for elemental solids and liquids essentially from first principles, based upon
a particular decomposition of the underlying condensed matter Hamiltonian for
the nuclei and electrons. We also point out that at low pressures the neglect
of anharmonic and electron-phonon terms, both contained in this formalism,
results in errors of less than 5% in the thermal parts of the thermodynamic
functions. Then we explicitly display the forms of the remaining terms in the
EOS, commenting on the use of experiment and electronic structure theory to
evaluate them. We also construct an EOS for Aluminum and compare the resulting
Hugoniot with data up to 5 Mbar, both to illustrate our method and to see
whether the approximation of neglecting anharmonicity et al. remains viable to
such high pressures. We find a level of agreement with experiment that is
consistent with the low-pressure results.Comment: Minor revisions for consistency with published versio
Four--dimensional Gravity from Singular Spaces
The modification to four--dimensional Einstein gravity at low energy in two
brane models is investigated within supergravity in singular spaces. Using
perturbation theory around a static BPS background, we study the effective
four--dimensional gravitational theory, a scalar--tensor theory, and derive the
Brans--Dicke parameter when matter is present on the positive tension brane
only. We show there is an attractor mechanism towards general relativity in the
matter dominated era. The dynamics of the interbrane distance are discussed.
Finally, when matter lives on both branes, we find that there is a violation of
the equivalence principle whose magnitude is governed by the warping of the
extra dimension.Comment: 9 pages, LaTe
A population-scale temporal case–control evaluation of COVID-19 disease phenotype and related outcome rates in patients with cancer in England (UKCCP)
Patients with cancer are at increased risk of hospitalisation and mortality following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, the SARS-CoV-2 phenotype evolution in patients with cancer since 2020 has not previously been described. We therefore evaluated SARS-CoV-2 on a UK populationscale from 01/11/2020-31/08/2022, assessing case-outcome rates of hospital assessment(s), intensive care admission and mortality. We observed that the SARS-CoV-2 disease phenotype has become less severe in patients with cancer and the non-cancer population. Case-hospitalisation rates for patients with cancer dropped from 30.58% in early 2021 to 7.45% in 2022 while case-mortality rates decreased from 20.53% to 3.25%. However, the risk of hospitalisation and mortality remains 2.10x and 2.54x higher in patients with cancer, respectively. Overall, the SARS-CoV-2 disease phenotype is less severe in 2022 compared to 2020 but patients with cancer remain at higher risk than the non-cancer population. Patients with cancer must therefore be empowered to live more normal lives, to see loved ones and families, while also being safeguarded with expanded measures to reduce the risk of transmission
Measuring symptom occurrence and symptom distress: development of the symptom experience index
A numerical approach based on transient thermal analysis to estimate the safe operating frequencies of thyristors
In vitro metabolism of dehydroepiandrosterone and testosterone by canine hair follicle cells
The psychological needs of patients receiving chemotherapy: an exploration of nurse perceptions
This study explored the perceptions of a group of registered oncology nurses about the psychological needs of patients with cancer receiving chemotherapy and how the nurses meet these. Eight nurses who provided chemotherapy and were working in a local oncology centre participated. A semi-structured interview was used to explore nurses’ perceptions, and how they meet these patients’ needs. The analysis of interview transcripts revealed that these nurses agreed that patients with cancer receiving chemotherapy had psychological needs. Moreover, they were conscious that some of the physical side-effects could have a psychological impact on the patients. Although nurses did not use any assessment tool for psychological assessment, they identified two main stages during the treatment when patients needed more psychological support: at the beginning and at the end of the chemotherapy. They explained how they tried to meet patients’ psychological needs but they also mentioned several factors that influenced the psychological support that patients received
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