712 research outputs found
A self-insulating, high-power, microwave source
We present first predictions for the performance of a novel, mildly relativistic (500keV, 2kA), X-band Cherenkov oscillator, nominally a variant of the backward-wave oscillator. The source operates with no externally-applied magnetic insulation, relying only on the self-fields of the electron beam for propagation. This significantly reduces the overall energy requirements for operation, along with the complexity; conventional (magnetically insulated) sources of this type typically require magnetic field strengths of 1 – 2T for efficient beam propagation, translating to a relatively large solenoid and associated power-supply. By eliminating this factor, the overall-efficiency of the source is tightly coupled to the conversion-efficiency between the beam and the wave. Conversion efficiencies in excess of 30% have been predicted for the source, when driven by a high-quality electron beam; the parameters of which were determined via numerical modelling of the electron gun. A tolerance study of variation in the beam parameters shows the efficiency remains better than ∼25% over the variation in critical control parameters expected in experiment, with clean excitation of the intended TM01 operating mode achieved at a stable output frequency of ~9.4GHz. The resonant frequency of the source was found to be insensitive to variation in the electron energy over an extended range (400-600keV)
Can Comprehensive Geriatric Assessment be delivered without the need for geriatricians? A formative evaluation in two perioperative surgical settings
Introduction
The aim of this study was to design an approach to improving care for frail older patients in hospital services where Comprehensive Geriatric Assessment (CGA) was not part of the clinical tradition.
Methods
The intervention was based on the principles of CGA, using quality improvement methodology to embed care processes. Qualitative methods and coproduction were used to inform development of the intervention, which was directed towards the health care professionals involved in peri-operative/surgical cancer care pathways in two large UK teaching hospitals.
A formative, qualitative evaluation was undertaken; data collection and analysis were guided by Normalisation Process Theory.
Results
The clinicians involved agreed to use the toolkit, identifying potential benefits including improved surgical decision making and delivery of interventions pre-operatively. However, sites concluded that pre-operative assessment was not the best place for CGA, and at the end of the 12-month trial, implementation was still nascent.
Efforts competed against the dominance of national time-limited targets, and concerns relating to patients’ immediate treatment and recovery.
Some participants involved in the peri-operative pathway felt that CGA required ongoing specialist input from geriatricians, but it was not clear that this was sustainable.
Conclusions
Clinical toolkits designed to empower non-geriatric teams to deliver CGA were received with initial enthusiasm, but did not fully achieve their stated aims due to the need for an extended period of service development with geriatrician support, competing priorities, and divergent views about appropriate professional domains.NIH
Ergodic Jacobi matrices and conformal maps
We study structural properties of the Lyapunov exponent and the
density of states for ergodic (or just invariant) Jacobi matrices in a
general framework. In this analysis, a central role is played by the function
as a conformal map between certain domains. This idea goes
back to Marchenko and Ostrovskii, who used this device in their analysis of the
periodic problem
Understanding variation in unplanned admissions of people aged 85 and over:a systems-based approach
AIM: To examine system characteristics associated with variations in unplanned admission rates in those aged 85+.DESIGN: Mixed methods.SETTING: Primary care trusts in England were ranked according to changes in admission rates for people aged 85+ between 2007 and 2009, and study sites selected from each end of the distribution: three 'improving' sites where rates had declined by more than 4% and three 'deteriorating' sites where rates had increased by more than 20%. Each site comprised an acute hospital trust, its linked primary care trust/clinical commissioning group, the provider of community health services and adult social care.PARTICIPANTS: A total of 142 representatives from these organisations were interviewed to understand how policies had been developed and implemented. McKinsey's 7S framework was used as a structure for investigation and analysis.RESULTS: In general, improving sites provided more evidence of comprehensive system focused strategies backed by strong leadership, enabling the development and implementation of policies and procedures to avoid unnecessary admissions of older people. In these sites, primary and intermediate care services appeared more comprehensive and better integrated with other parts of the system, and policies in emergency departments were more focused on providing alternatives to admission.CONCLUSIONS: Health and social care communities which have attenuated admissions of people aged 85+ prioritised developing a shared vision and strategy, with sustained implementation of a suite of interventions.</p
Dynamics of DNA Ejection From Bacteriophage
The ejection of DNA from a bacterial virus (``phage'') into its host cell is
a biologically important example of the translocation of a macromolecular chain
along its length through a membrane. The simplest mechanism for this motion is
diffusion, but in the case of phage ejection a significant driving force
derives from the high degree of stress to which the DNA is subjected in the
viral capsid. The translocation is further sped up by the ratcheting and
entropic forces associated with proteins that bind to the viral DNA in the host
cell cytoplasm. We formulate a generalized diffusion equation that includes
these various pushing and pulling effects and make estimates of the
corresponding speed-ups in the overall translocation process. Stress in the
capsid is the dominant factor throughout early ejection, with the pull due to
binding particles taking over at later stages. Confinement effects are also
investigated, in the case where the phage injects its DNA into a volume
comparable to the capsid size. Our results suggest a series of in vitro
experiments involving the ejection of DNA into vesicles filled with varying
amounts of binding proteins from phage whose state of stress is controlled by
ambient salt conditions or by tuning genome length.Comment: 17 pages, 5 figure
Why are we misdiagnosing urinary tract infection in older patients? A qualitative inquiry and roadmap for staff behaviour change in the emergency department
Purpose - The aim of this study was to identify the psychological and behavioural factors influencing clinicians managing older people with possible UTI in urgent care settings, and to develop an improvement roadmap. Methods - Michie’s behaviour change wheel and COM-B (Capability, Opportunity, Motivation, Behaviour Change) models were used as the theoretical basis for this study. Semi-structured interviews were undertaken with 21 purposively selected medical and nursing staff in a large urban emergency department in the East Midlands, United Kingdom. Analysis was informed by the framework approach. A participatory design approach was used to develop an improvement roadmap. Results - Key themes emerging from the semi-structured interviews included lack of knowledge on the role of urine dipstick testing, bias towards older people, automatic testing, time and resource constraints, pressures from peers and patients, and fear of the legal consequences of inaction. A thematic networks map indicated complex interactions between psychological and behavioural factors. Among more than 50 different intervention ideas identified by the workshop participants, two interventions were prioritised for implementation: i) controlling the use of dip stick urine tests; ii) providing individualised feedback to staff regarding the outcomes of patients diagnosed and treated for UTI. Conclusions - Psychological and behavioural factors play a significant role in the misdiagnosis of UTI in older people. Systematic approaches incorporating these factors might improve patient outcomes. Future studies should focus on implementation and evaluating their effectiveness and sustainability
East Midlands Research into Ageing Network (EMRAN) Discussion Paper Series
Academic geriatric medicine in Leicester
.
There has never been a better time to consider joining us. We have recently appointed a
Professor in Geriatric Medicine, alongside Tom Robinson in stroke and Victoria Haunton,
who has just joined as a Senior Lecturer in Geriatric Medicine. We have fantastic
opportunities to support students in their academic pursuits through a well-established
intercalated BSc programme, and routes on through such as ACF posts, and a successful
track-record in delivering higher degrees leading to ACL post. We collaborate strongly
with Health Sciences, including academic primary care. See below for more detail on our
existing academic set-up.
Leicester Academy for the Study of Ageing
We are also collaborating on a grander scale, through a joint academic venture focusing
on ageing, the ‘Leicester Academy for the Study of Ageing’ (LASA), which involves the
local health service providers (acute and community), De Montfort University; University
of Leicester; Leicester City Council; Leicestershire County Council and Leicester Age UK.
Professors Jayne Brown and Simon Conroy jointly Chair LASA and have recently been
joined by two further Chairs, Professors Kay de Vries and Bertha Ochieng. Karen
Harrison Dening has also recently been appointed an Honorary Chair.
LASA aims to improve outcomes for older people and those that care for them that takes
a person-centred, whole system perspective. Our research will take a global perspective,
but will seek to maximise benefits for the people of Leicester, Leicestershire and Rutland,
including building capacity. We are undertaking applied, translational, interdisciplinary
research, focused on older people, which will deliver research outcomes that address
domains from: physical/medical; functional ability, cognitive/psychological; social or
environmental factors. LASA also seeks to support commissioners and providers alike for
advice on how to improve care for older people, whether by research, education or
service delivery. Examples of recent research projects include: ‘Local History Café’
project specifically undertaking an evaluation on loneliness and social isolation; ‘Better
Visits’ project focused on improving visiting for family members of people with dementia
resident in care homes; and a study on health issues for older LGBT people in Leicester.
Clinical Geriatric Medicine in Leicester
We have developed a service which recognises the complexity of managing frail older
people at the interface (acute care, emergency care and links with community services).
There are presently 17 consultant geriatricians supported by existing multidisciplinary
teams, including the largest complement of Advance Nurse Practitioners in the country.
Together we deliver Comprehensive Geriatric Assessment to frail older people with
urgent care needs in acute and community settings.
The acute and emergency frailty units – Leicester Royal Infirmary
This development aims at delivering Comprehensive Geriatric Assessment to frail older
people in the acute setting. Patients are screened for frailty in the Emergency
Department and then undergo a multidisciplinary assessment including a consultant
geriatrician, before being triaged to the most appropriate setting. This might include
admission to in-patient care in the acute or community setting, intermediate care
(residential or home based), or occasionally other specialist care (e.g. cardiorespiratory).
Our new emergency department is the county’s first frail friendly build and includes
fantastic facilities aimed at promoting early recovering and reducing the risk of hospital
associated harms.
There is also a daily liaison service jointly run with the psychogeriatricians (FOPAL); we
have been examining geriatric outreach to oncology and surgery as part of an NIHR
funded study.
We are home to the Acute Frailty Network, and those interested in service developments
at the national scale would be welcome to get involved.
Orthogeriatrics
There are now dedicated hip fracture wards and joint care with anaesthetists,
orthopaedic surgeons and geriatricians. There are also consultants in metabolic bone
disease that run clinics.
Community work
Community work will consist of reviewing patients in clinic who have been triaged to
return to the community setting following an acute assessment described above.
Additionally, primary care colleagues refer to outpatients for sub-acute reviews. You will
work closely with local GPs with support from consultants to deliver post-acute, subacute,
intermediate and rehabilitation care services.
Stroke Medicine
24/7 thrombolysis and TIA services. The latter is considered one of the best in the UK
and along with the high standard of vascular surgery locally means one of the best
performances regarding carotid intervention
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