685 research outputs found

    Three Dimensional Electrical Impedance Tomography

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    The electrical resistivity of mammalian tissues varies widely and is correlated with physiological function. Electrical impedance tomography (EIT) can be used to probe such variations in vivo, and offers a non-invasive means of imaging the internal conductivity distribution of the human body. But the computational complexity of EIT has severe practical limitations, and previous work has been restricted to considering image reconstruction as an essentially two-dimensional problem. This simplification can limit significantly the imaging capabilities of EIT, as the electric currents used to determine the conductivity variations will not in general be confined to a two-dimensional plane. A few studies have attempted three-dimensional EIT image reconstruction, but have not yet succeeded in generating images of a quality suitable for clinical applications. Here we report the development of a three-dimensional EIT system with greatly improved imaging capabilities, which combines our 64-electrode data-collection apparatus with customized matrix inversion techniques. Our results demonstrate the practical potential of EIT for clinical applications, such as lung or brain imaging and diagnostic screening

    Virtual outreach: economic evaluation of joint teleconsultations for patients referred by their general practitioner for a specialist opinion

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    Objectives To test the hypotheses that, compared with conventional outpatient consultations, joint teleconsultation (virtual outreach) would incur no increased costs to the NHS, reduce costs to patients, and reduce absences from work by patients and their carers.Design Cost consequences study alongside randomised controlled trial.Setting Two hospitals in London and Shrewsbury and 29 general practices in inner London and Wales.Participants 3170 patients identified; 2094 eligible for inclusion and willing to participate. 1051 randomised to virtual outreach and 1043 to standard outpatient appointments.Main outcome measures NHS costs, patient costs, health status (SF-12), time spent attending index consultation, patient satisfaction.Results Overall six month costs were greater for the virtual outreach consultations (pound724 per patient) than for conventional outpatient appointments (pound625): difference in means pound99 ($162; is not an element of138) (95% confidence interval pound10 to pound187, P=0.03). if the analysis is restricted to resource items deemed "attributable" to the index consultation, six month costs were still greater for virtual outreach: difference in means pound108 (pound73 to pound142, P < 0.0001). In both analyses the index consultation accounted for the excess cost. Savings to patients in terms of costs and time occurred in both centres: difference in mean total patient cost 8 pound (5 pound to 10 pound, P < 0.0001). Loss of productive time was less in the virtual outreach group: difference in mean cost pound11 (pound10 to pound12, P < 0.0001).Condusion The main hypothesis that virtual outreach would be cost neutral is rejected, but the hypotheses that costs to patients and losses in productivity would be lower are supported

    The Incidence Of Prescribing Errors In An Eye Hospital

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    BACKGROUND: Relatively little is known about the incidence of prescribing errors and there has been no work on this in a single specialty ophthalmic hospital. Knowing where and when errors are most likely to occur is generally felt to be the first step in trying to prevent these errors. This study is an attempt in, the setting of an eye hospital, to try to identify and attribute these medication errors. METHODS: The study setting was a single specialty eye hospital geographically separated from the main general hospital. Pharmacists prospectively recorded the number of errors of prescribing during a 4 week period at an eye hospital in UK. The errors were categorised as error of prescription writing or drug error. Potential significance of the errors was not addressed. RESULTS: Overall 144/1952 (8%)prescription sheets had errors. 7% of the total errors were errors of prescription writing while 1% were drug errors. The majority of errors were made by junior doctors and no drug errors were made by senior doctors. The outpatients department had by far the highest prevalence of errors. CONCLUSION: Certain areas within the hospital and certain grades of staff are more prone to drug errors. Further study is required to look at the reasons why this is so and what systems can be put in place to reduce these errors

    One-step isolation and biochemical characterization of a highlyactive plant PSII monomeric core

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    We describe a one-step detergent solubilization protocol for isolating a highly active form of Photosystem II (PSII) from Pisum sativum L. Detailed characterization of the preparation showed that the complex was a monomer having no light harvesting proteins attached. This core reaction centre complex had, however, a range of low molecular mass intrinsic proteins as well as the chlorophyll binding proteins CP43 and CP47 and the reaction centre proteins D1 and D2. Of particular note was the presence of a stoichiometric level of PsbW, a low molecular weight protein not present in PSII of cyanobacteria. Despite the high oxygen evolution rate, the core complex did not retain the PsbQ extrinsic protein although there was close to a full complement of PsbO and PsbR and partial level of PsbP. However, reconstitution of PsbP and PsbPQ was possible. The presence of PsbP in absence of LHCII and other chlorophyll a/b binding proteins confirms that LHCII proteins are not a strict requirement for the assembly of this extrinsic polypeptide to the PSII core in contrast with the conclusion of Caffarri et al. (2009)

    Strategies to self-manage side-effects of adjuvant endocrine therapy among breast cancer survivors: an umbrella review of empirical evidence and clinical guidelines

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    Purpose: Side-effects of adjuvant endocrine therapy (AET) are common in breast cancer survivors, and can affect adherence to treatment. We synthesised the evidence for strategies to self-manage these side-effects. Methods: We searched for systematic reviews and clinical guidelines on self-management strategies for AET side-effects (arthralgia, fatigue, hot flashes, gastrointestinal discomfort, nausea, vulvovaginal symptoms, and sleep disturbance). We searched oncology organisation’s websites and eight databases (Inception-November 2020). Screening, data extraction and quality assessment were completed independently in duplicate. PROSPERO: 2019CRD4201914001. Results: We identified 33 systematic reviews and 18 clinical guidelines. 21% of reviews were high quality, and the average quality score for guidelines was 44%. Evidence for most strategies was absent or weak. There was consensus from a low-quality review and multiple guidelines to recommend moisturisers, gels and lubricants for vulvovaginal symptoms. Evidence was weak for physical activity for self-managing most symptoms, although two high-quality reviews indicated yoga and aerobic exercise could reduce fatigue. Primary research was often biased by weak and underpowered study designs. Eleven reviews did not report information on adverse events. Conclusions: Most self-management strategies for breast cancer survivors experiencing side-effects from AET lack evidence. Primary research is needed using high-quality well-powered designs focusing on implementable strategies. Implications for Cancer Survivors: Patients and clinicians should be aware that although the risk of harm is low for these self-management strategies, the likelihood of benefit is often unclear. Women should consider moisturisers, gels or lubricants for self-managing vulvovaginal symptoms, and yoga or aerobic exercise for alleviating fatigue

    Optimizing Optical Flow Cytometry for Cell Volume-Based Sorting and Analysis

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    Cell size is a defining characteristic central to cell function and ultimately to tissue architecture. The ability to sort cell subpopulations of different sizes would facilitate investigation at genomic and proteomic levels of mechanisms by which cells attain and maintain their size. Currently available cell sorters, however, cannot directly measure cell volume electronically, and it would therefore be desirable to know which of the optical measurements that can be made in such instruments provide the best estimate of volume. We investigated several different light scattering and fluorescence measurements in several different cell lines, sorting cell fractions from the high and low end of distributions, and measuring volume electronically to determine which sorting strategy yielded the best separated volume distributions. Since we found that different optical measurements were optimal for different cell lines, we suggest that following this procedure will enable other investigators to optimize their own cell sorters for volume-based separation of the cell types with which they work

    Cost-effectiveness of the SEN-concept: Specialized Emergency Nurses (SEN) treating ankle/foot injuries

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    <p>Abstract</p> <p>Background</p> <p>Emergency Departments (EDs) are confronted with progressive overcrowding. As a consequence, the workload for ED physicians increases and waiting times go up with the risk of unnecessary complications and patient dissatisfaction. To cope with these problems, Specialized Emergency Nurses (SENs), regular ED-nurses receiving a short, injury-specific course, were trained to assess and treat minor injuries according to a specific protocol.</p> <p>Methods</p> <p>An economic evaluation was conducted alongside a randomized controlled trial comparing House Officers (HOs) and SENs in their assessment of ankle and foot injuries. Cost prices were established for all parts of healthcare utilization involved. Total costs of health care utilization were computed per patient in both groups. Cost-effectiveness was investigated by comparing the difference in total cost between groups with the difference in sensitivity and specificity between groups in diagnosing fractures and severe sprains. Finally, cost-effectiveness ratios were calculated and presented on a cost-effectiveness plane.</p> <p>Results</p> <p>No significant differences were seen between treatment groups for any of the health care resources assessed. However, the waiting times for both first assessment by a treatment officer and time spent waiting between hearing the diagnosis and final treatment were significantly longer in the HO group. There was no statistically significant difference in costs between groups. The total costs were € 186 (SD € 623) for patients in the SEN group and € 153 (SD € 529) for patients in the HO group. The difference in total costs was € 33 (95% CI: – € 84 to € 155). The incremental cost-effectiveness ratio was € 27 for a reduction of one missed diagnosis and € 18 for a reduction of one false negative.</p> <p>Conclusion</p> <p>Considering the benefits of the SEN-concept in terms of decreased workload for the ED physicians, increased patient satisfaction and decreased waiting times, SENs appear to be a useful solution to the problem of ED crowding.</p

    Killing of Targets by CD8+ T Cells in the Mouse Spleen Follows the Law of Mass Action

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    It has been difficult to correlate the quality of CD8 T cell responses with protection against viral infections. To investigate the relationship between efficacy and magnitude of T cell responses, we quantify the rate at which individual CD8 effector and memory T cells kill target cells in the mouse spleen. Using mathematical modeling, we analyze recent data on the loss of target cells pulsed with three different peptides from the mouse lymphocytic choriomeningitis virus (LCMV) in mouse spleens with varying numbers of epitope-specific CD8 T cells. We find that the killing of targets follows the law of mass-action, i.e., the death rate of individual target cells remains proportional to the frequency (or the total number) of specific CD8 T cells in the spleen despite the fact that effector cell densities and effector to target ratios vary about a 1000-fold. The killing rate of LCMV-specific CD8 T cells is largely independent of T cell specificity and differentiation stage. Our results thus allow one to calculate the critical T cell concentration at which growth of a virus with a given replication rate can be prevented from the start of infection by memory CD8 T cell response
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