5,721 research outputs found

    Prognostic variables and scores identifying the last year of life in COPD: a systematic review protocol

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    Introduction People living with advanced chronic obstructive pulmonary disease (COPD) suffer from significant morbidity, reduced quality of life and high mortality, and are likely to benefit from many aspects of a palliative care approach. Prognostic estimates are a meaningful part of decision-making and better evidence for such estimates would facilitate advance care planning. We aim to provide quality evidence on known prognostic variables and scores which predict a prognosis in COPD of <12 months for use in the community. Methods and analysis We will conduct a systematic review of randomised or quasi-randomised controlled trials, prospective and retrospective longitudinal cohort and case–control studies on prognostic variables, multivariate scores or models for COPD. The search will cover the period up to April 2016. Study selection will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, with data extraction using fields from the Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS) checklist for multivariate models, and study quality will be assessed using a modified version of the Quality In Prognosis Studies (QUIPS) tool. Ethics and dissemination The results will be disseminated through peer-reviewed publications and national and international conference presentations

    Dynamics of one-dimensional tight-binding models with arbitrary time-dependent external homogeneous fields

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    The exact propagators of two one-dimensional systems with time-dependent external fields are presented by following the path-integral method. It is shown that the Bloch acceleration theorem can be generalized to the impulse-momentum theorem in quantum version. We demonstrate that an evolved Gaussian wave packet always keeps its shape in an arbitrary time-dependent homogeneous driven field. Moreover, that stopping and accelerating of a wave packet can be achieved by the pulsed field in a diabatic way.Comment: 8 pages, 6 figure

    Su(3) Algebraic Structure of the Cuprate Superconductors Model based on the Analogy with Atomic Nuclei

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    A cuprate superconductor model based on the analogy with atomic nuclei was shown by Iachello to have an su(3)su(3) structure. The mean-field approximation Hamiltonian can be written as a linear function of the generators of su(3)su(3) algebra. Using algebraic method, we derive the eigenvalues of the reduced Hamiltonian beyond the subalgebras u(1)⨂u(2)u(1)\bigotimes u(2) and so(3)so(3) of su(3)su(3) algebra. In particular, by considering the coherence between s- and d-wave pairs as perturbation, the effects of coherent term upon the energy spectrum are investigated

    While We Waited: Incidence and Predictors of Falls in Older Adults With Cataract.

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    PURPOSE: Strong evidence indicates an increased fall risk associated with cataract. Although cataract surgery can restore sight, lengthy wait times are common for public patients in many high-income countries. This study reports incidence and predictors of falls in older people with cataract during their surgical wait. METHODS: Data from a prospective study of falls in adults aged ≥65 years who were awaiting cataract surgery in public hospitals in Australia were analyzed. Participants underwent assessment of vision, health status, and physical function, and recalled falls in the previous 12 months. Falls were self-reported prospectively during the surgical wait. RESULTS: Of 329 participants, mean age was 75.7 years; 55.2% were female. A total of 267 falls were reported by 101 (30.7%) participants during the surgical wait (median observation time, 176 days): an incidence of 1.2 falls per person-year (95% confidence interval [CI] 1.0-1.3). Greater walking activity (incidence rate ratio [IRR] 1.06, 95% CI 1.01-1.10; P = 0.02, per additional hour/week), poorer health-related quality of life (IRR 1.12, 95% CI 1.05-1.20; P < 0.001, per 5-unit decrease), and a fall in the prior 12 months (IRR 2.48, 95% CI 1.57-3.93; P < 0.001) were associated with incident falls. No visual measure independently predicted fall risk. More than one-half (51.7%) of falls were injurious. CONCLUSIONS: We found a substantial rate of falls and fall injury in older adults with cataract who were awaiting surgery. Within this relatively homogenous cohort, measures of visual function alone inadequately predicted fall risk. Assessment of exposure to falls through physical activity frequency may prove valuable in identifying those more likely to fall during the surgical wait

    Optimizing the feeding operation of recombinant Escherichia coli during fed-batch cultivation based on Pontryagin's minimum principle

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    Recombinant Escherichia coli BL21 was used to produce human-like collagen in fed-batch culture. After building and analyzing the kinetic models of fed-batch cultures, the maximum specific growth rate, Yx/s and Yp/s were 0.411 h-1 , 0.428 g·g-1 and 0.0716 g/g, respectively. The square error of cell growth models, glucose consumption model and human-like collagen formation were almost all around 94%, which indicated that the kinetic model could describe the actual change well. According to the target, that is, to gain the highest productivity of human-like collagen, the feeding rate (F) was worked out on the basis of Pontryagin's minimum principle. In the verification experiments, the specific growth rate was controlled at 0.15 and 0.04 h-1 at the fed-batch and induction phase, respectively. The result showed that the concentrations of cell and human-like collagen could reach 87.6 and 6.11 g·L-1, and they were raised by 17.9 and 18.6%, respectively.Key words: Fed-batch culture, human-like collagen, maximum specific growth rate, Pontryagin's minimum principle, recombinant Escherichia coli

    Phosphorylation of the androgen receptor is associated with reduced survival in hormonerefractory prostate cancer patients

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    Cell line studies demonstrate that the PI3K/Akt pathway is upregulated in hormone-refractory prostate cancer (HRPC) and can result in phosphorylation of the androgen receptor (AR). The current study therefore aims to establish if this has relevance to the development of clinical HRPC. Immunohistochemistry was employed to investigate the expression and phosphorylation status of Akt and AR in matched hormone-sensitive and -refractory prostate cancer tumours from 68 patients. In the hormone-refractory tissue, only phosphorylated AR (pAR) was associated with shorter time to death from relapse (&lt;i&gt;P&lt;/i&gt;=0.003). However, when an increase in expression in the transition from hormone-sensitive to -refractory prostate cancer was investigated, an increase in expression of PI3K was associated with decreased time to biochemical relapse (&lt;i&gt;P&lt;/i&gt;=0.014), and an increase in expression of pAkt&lt;sup&gt;473&lt;/sup&gt; and pAR&lt;sup&gt;210&lt;/sup&gt; were associated with decreased disease-specific survival (&lt;i&gt;P&lt;/i&gt;=0.0019 and 0.0015, respectively). Protein expression of pAkt&lt;sup&gt;473&lt;/sup&gt; and pAR&lt;sup&gt;210&lt;/sup&gt; also strongly correlated (&lt;i&gt;P&lt;/i&gt;&#60;0.001, c.c.=0.711) in the hormone-refractory prostate tumours. These results provide evidence using clinical specimens, that upregulation of the PI3K/Akt pathway is associated with phosphorylation of the AR during development of HRPC, suggesting that this pathway could be a potential therapeutic target

    Delocalized single-photon Dicke states and the Leggett- Garg inequality in solid state systems

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    We show how to realize a single-photon Dicke state in a large one-dimensional array of two- level systems, and discuss how to test its quantum properties. Realization of single-photon Dicke states relies on the cooperative nature of the interaction between a field reservoir and an array of two-level-emitters. The resulting dynamics of the delocalized state can display Rabi-like oscillations when the number of two-level emitters exceeds several hundred. In this case the large array of emitters is essentially behaving like a mirror-less cavity. We outline how this might be realized using a multiple-quantum-well structure and discuss how the quantum nature of these oscillations could be tested with the Leggett-Garg inequality and its extensions.Comment: 29 pages, 5 figures, journal pape

    Sex-specific incidence and temporal trends in solid tumours in young people from Northern England, 1968–2005

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    <p>Abstract</p> <p>Background</p> <p>This study examined sex-specific patterns and temporal trends in the incidence of solid tumours in the Northern Region of England from 1968 to 2005. This updates earlier analyses from the region where sex was not considered in depth. Sex-specific analyses were carried out to determine whether sex differences might provide clues to aetiology.</p> <p>Methods</p> <p>Details of 3576 cases, aged 0–24 years, were obtained from a specialist population-based cancer registry. There were 1843 males (886 aged 0–14 years and 957 aged 15–24 years) and 1733 females (791 aged 0–14 years and 942 aged 15–24 years). Age-standardized incidence rates (per million population) were calculated. Linear regression was used to analyze temporal trends in incidence and annual percentage changes were estimated. Analyses were stratified by sex and by age-group.</p> <p>Results</p> <p>There were marked differences in incidence patterns and trends between males and females and also between age-groups. For males central nervous system (CNS) tumours formed the largest proportion of under-15 cases and germ cell tumours was the largest group in the 15–24's, whilst for females CNS tumours dominated in the under-15's and carcinomas in the older group. For 0–14 year olds there were male-specific increases in the incidence of rhabdomyosarcoma (2.4% per annum; 95% CI: 0.2%–4.5%) and non-melanotic skin cancer (9.6%; 95% CI: 0.0%–19.2%) and female-specific increases for sympathetic nervous system tumours (2.2%; 95% CI: 0.4%–3.9%), gonadal germ cell tumours (8.6%; 95% CI: 4.3%–12.9%) and non-gonadal germ cell tumours (5.4%; 95% CI: 2.8%–7.9%). For 15–24 year olds, there were male-specific increases in gonadal germ cell tumours (1.9%; 95% CI: 0.3%–3.4%), non-gonadal germ cell tumours (4.4%; 95% CI: 1.1%–7.7%) and non-melanotic skin cancer (4.7%; 95% CI: 0.5%–8.9%) and female-specific increases for osteosarcoma (3.5%; 95% CI: 0.5%–6.5%), thyroid cancer (2.8%; 95% CI: 0.1%–5.6%) and melanoma (4.6%; 95% CI: 2.2%–7.1%).</p> <p>Conclusion</p> <p>This study has highlighted notable differences between the sexes in incidence patterns and trends for solid tumours. Some of these sex-specific differences could have been obscured if males and females had been analysed together. Furthermore, they suggest aetiological differences or differential susceptibility to environmental factors between males and females.</p
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