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Biomedical subjects

J S Briggs

Publications and source records attributed to J S Briggs.

10 recordsLinked to original sources
PubMed2006

Absorption spectra of quantum aggregates interacting via long-range forces.

We present a simple formula by which the shape of the absorption spectrum of an aggregate of quantum "monomers" (cold atoms, molecules, quantum dots, nanoparticles, etc.) interacting via dipole-dipole forces can be calculated from the averaged spectrum of the quantum monomer itself. Spectral broadening, due to a wide variety of causes, is included explicitly so that the formula is applicable not only to the idealization of a discrete spectrum but also to the practical situation of a continuously broadened spectrum. In simple cases, analytic results are obtained showing the strong dependence of the aggregate spectrum on the precise nature of the broadening of the quantum monomer spectrum. The formula is compared with results of exact diagonalization of model aggregate Hamiltonians and with experiment.

Journal Article↗
PubMed2005

Vibronic energies and spectra of molecular dimers.

We consider three distinct methods of calculating the vibronic levels and absorption spectra of molecular dimers coupled by dipole-dipole interactions. The first method is direct diagonalization of the vibronic Hamiltonian in a basis of monomer eigenstates. The second method is to use creation and annihilation operators leading in harmonic approximation to the Jaynes-Cummings Hamiltonian. The adiabatic approximation to this problem provides insight into spectral behavior in the weak and strong coupling limits. The third method, which serves as a check on the accuracy of the previous methods, is a numerically exact solution of the time-dependent Schrodinger equation. Using these methods, dimer spectra are calculated for three separate dye molecules and show good agreement with measured spectra.

Journal Article↗
PubMed2005

The ISABEL user survey.

ISABEL is a web-based clinical decision-support system for use by health care professionals. The Web site has been developed by the ISABEL Medical Charity. The system has come to the attention of the Department of Health, which is examining its potential effectiveness in the wider clinical context and exploring options for promoting its wider use in the NHS. The objectives of the work reported here were to review the existing use of ISABEL and to identify impediments to its development. A questionnaire was sent by e-mail to selected users of the system. Based on an analysis of the results (n=518), we found ISABEL to be a useful tool with many users. We believe that there is evidence of its success sufficient to support its continued availability and development. However, the largest hurdles to its increased use are systemic ones within the NHS and the way services are delivered.

Consumer Behavior↗
PubMed2005

Measuring clinical performance using routinely collected clinical data.

Following the well-publicized problems with paediatric cardiac surgery at the Bristol Royal Infirmary, there is wide public interest in measures of hospital performance. The Kennedy report on the BRI events suggested that such measures should be meaningful to the public, case-mix-adjusted, and based on data collected as part of routine clinical care. We have found that it is possible to predict in-hospital mortality (a measure readily understood by the public) using simple routine data-age, mode of admission, sex, and routine blood test results. The clinical data items can be obtained at a single venesection, are commonly collected in the routine care of patients, are already stored on hospital core IT systems, and so place no extra burden on the clinical staff providing care. Such risk models could provide a metric for use in evidence-based clinical performance management. National application is logistically feasible.

Cardiology Service, Hospital↗
PubMed2003

Shape-amplitude representation of N-particle photofragmentation processes.

The general form of the multiparticle photofragmentation matrix element in dipole approximation is derived. Using two noncolinear momentum vectors to create a coordinate system enables the extraction of shape amplitudes depending only on lengths and mutual angles of the momentum vectors, i.e., on body fixed quantities, defining the fragmentation configuration. This is in contrast to previous parametrizations and, in particular, allows selection rules to be derived in a simpler and more transparent way.

Journal Article↗
PubMed2002

Elimination of body-frame singularities in the separation of three collective angles in quantum N-body problems.

The appearance of body-frame singularities in gauge potentials when three collective angles are separated by means of Wigner D-functions is a fundamental difficulty in the quantum N-body problem. We show that the use of the overcomplete basis of minimal multipolar harmonics allows these singularities to be avoided at the expense of increasing the dimension of the resulting system of coupled equations describing the internal motion of the system.

Journal Article↗
PubMed2000

Measuring the readership of a health-related Website.

A national database of telemedicine was set up with the sponsorship of the British government to provide a source of information to anyone researching the field or proposing a telemedicine project. To monitor the readership of the database we subscribed to a free Internet service called Extreme Tracking. Since the Website was launched there have been over 9000 visits from over 5000 different Internet addresses. The peak was in the week after launch, when it had 400 visitors in four days. Subsequently, the number of visits tailed off slightly, but nine months later the database was still attracting about 800 visits per month. The majority of visits were via links from other Websites. Of the 288 different Websites identified, the one operated by the UK National Health Service (NHS) Information Authority generated the most visits, suggesting that many readers were from within the NHS. The second most common form of referral was from search engines. Most visits were on weekdays and during normal UK working hours. Taken together with the fact that the Internet domain that generated most visits was the '.uk' one, we concluded that most readers were based in the UK and accessed the site as part of their jobs rather than as a spare-time activity. This is encouraging for the take-up of telemedicine in the UK.

Bibliometrics↗
PubMedDate not supplied

Internet developments and their significance for healthcare.

This paper reviews some recent developments in the technology of the Internet, and shows how they may affect the way in which healthcare is provided. Starting with a brief technical history of the Internet, the paper discusses some of the technical developments that have taken place or been proposed in recent years, and speculates on the realities of their adoption within the next five years. The paper also discusses trends in public accessibility to the Internet and the development of Internet services. Finally, the impact of the technological developments on the way in which new healthcare services may be provided is discussed. Our conclusions are that the growth rate in Internet access and the improvements in performance resulting from the new technologies will make the Internet the focus of many new healthcare developments, in particular in the areas of telemedicine and in communication between patient and healthcare professionals. Increasingly, the Internet will be used to convey more 'real-time' information.

Delivery of Health Care↗
PubMedDate not supplied

Lessons learned from an Internet GP information system.

We describe the prototype of an application that in actual use would allow GPs to find out more information about consultants at hospitals. This would aid the GP in making the decision about which consultant a patient should be referred to. The requirements of the application from the GP's perspective are described, together with some of the issues that have to be resolved before hospitals can provide the necessary information in a standard format. The application is implemented as a client--server system using standard Internet technologies such as Java and HTML. This architecture has a number of advantages but also revealed some issues concerning security and the format of data, among other things. The project showed that there is a desire for such a system and that that desire can be fulfilled at a relatively low cost.

Family Practice↗