110 research outputs found

    NON-FREE VORTEX FLOW EFFECTS IN AN AXIAL FLOW ROTOR

    Get PDF
    This paper presents the analysis of three-dimensional flow field developing through an industrial axial flow fan rotor of non-free vortex design carried out on the basis of concerted experimental and numerical investigations. The paper focuses on non-free vortex flow effects requiring consideration in rotor blade design theories. The distortion of stream surfaces through the blading has been observed and a quantitative analysis of its effects on the blade loading condition has been carried out in the through-flow core region. The streamlines close to the blades have been modelled fitting to outward and inward conical stream tubes on the blade suction and pressure sides, respectively - termed `cone couple model´. It has been pointed out that the blade lift can be satisfactorily described at midspan on the basis of the cone couple model, with use of pitch-averaged flow data. The loading aspects of the tested axial rotor have been discussed on the basis of both the pressure distribution in the vicinity of the blades and pitch-averaged flow data obtained upstream and downstream of the rotor. Sample calculations suggested that separate optimisation of the blade suction and pressure sides is essential if the three-dimensional blade-to-blade flow is intended to be considered in NFV fan design with use of two-dimensional cascade data

    Single, dual and multiple respiratory virus infections and risk of hospitalization and mortality

    Get PDF
    Respiratory virus infections cause a significant number of hospitalization and deaths globally. This study investigated the association between single and multiple respiratory virus infections and risk of admission to a general ward, intensive care unit or death in patients aged 0–105 years (mean ± s.d. = 24·4 ± 24·1 years), from North West England, that were tested for respiratory virus infections between January 2007 and June 2012. The majority of infections were in children aged ⩽5 years. Dual or multiple infections occurred in 10·4% (1214/11 715) of patients, whereas single infection occurred in 89·6% (10 501/11 715). Rhinovirus was the most common co-infecting virus (occurring in 69·5%; 844/1214 of co-infections). In a multivariate logistic regression model, multiple infections were associated with an increased risk of admission to a general ward [odds ratio (OR) 1·43, 95% confidence interval (CI) 1·2–1·7, P < 0·0001]. On the other hand, patients with respiratory syncytial virus (RSV) and human parainfluenza virus types 1–3 (hPIV1–3), as a single infection, had a higher risk of being admitted to a general ward (OR 1·49, 95% CI 1·28–1·73, P < 0·0001 and OR 1·34, 95% CI 1·003–1·8, P = 0·05, respectively); admitted to an intensive-care unit or dying (OR 1·5, 95% CI 1·20–2·0, P = 0·001 and OR 1·60, 95% CI 1·02–2·40, P = 0·04, respectively). This result emphasizes the importance of RSV, hPIV and mixed infections and calls for research on vaccines, drugs and diagnostic tests targeting these respiratory viruses

    Immunogenicity of vaccination against influenza, Streptococcus pneumoniae and Haemophilus influenzae type B in patients with multiple myeloma

    Get PDF
    Vaccination against influenza and Streptococcus pneumoniae is recommended for elderly and immunocompromised individuals. However, there is little information concerning the efficacy of vaccination in specific groups of patients. In this study, 52 patients underwent vaccination against influenza, S. pneumoniae and Haemophilus influenzae type b (Hib) as they attended hospital outpatient clinics. Serum was analysed prior to vaccination and 4–6 weeks afterwards. Antibody titres against S. pneumoniae and Hib were compared with reference values corresponding to the geometric mean titres of a healthy UK population. For influenza vaccination, haemagglutination inhibition (HI) titres were measured against three inactivated strains; a titre of ≥ 1/40 was considered protective. No patient had protective titres to all three antigens prior to vaccination and 41 patients (85%) had titres < 1/40 to all 3 strains. Post vaccination only 9/48 patients (19%) achieved protective antibody titres. Resistance to S. pneumoniae and response to Pneumovax II was also poor: prevaccination, 45 patients (93%) had suboptimal antibody titres and in 26/43 patients (61%) titres remained low post vaccination. Resistance to Hib and response to vaccination was comparable with the healthy adult UK population. These results question the practice of routine influenza and pneumococcal vaccination in myeloma patients. © 2000 Cancer Research Campaig

    Visualizing Sets with Linear Diagrams.

    Get PDF
    This paper presents the first design principles that optimize the visualization of sets using linear diagrams.These principles are justified through empirical studies that evaluate the impact of graphical features on taskperformance. Linear diagrams represent sets using straight line segments, with line overlaps correspondingto set intersections. This study builds on recent empirical research, which establishes that linear diagramscan be superior to prominent set visualization techniques, namely Euler and Venn diagrams. We addressthe problem of how to best visualize overlapping sets using linear diagrams. To solve the problem, weinvestigate which graphical features of linear diagrams significantly impact user task performance. Tothis end, we conducted seven crowdsourced empirical studies involving a total of 1,760 participants. Thesestudies allowed us to identify the following design principles, which significantly aid task performance: usea minimal number of line segments, use guidelines where overlaps start and end, and draw lines that arethin as opposed to thick bars. We also evaluated the following graphical properties that did not significantlyimpact task performance: color, orientation, and set order. The results are brought to life through a freelyavailable software implementation that automatically draws linear diagrams with user-controlled graphicalchoices. An important consequence of our research is that users are now able to create effective visualizationsof sets automatically, thus improving human–computer interaction

    MYC Overexpression Induces Prostatic Intraepithelial Neoplasia and Loss of Nkx3.1 in Mouse Luminal Epithelial Cells

    Get PDF
    Lo-MYC and Hi-MYC mice develop prostatic intraepithelial neoplasia (PIN) and prostatic adenocarcinoma as a result of MYC overexpression in the mouse prostate[1]. However, prior studies have not determined precisely when, and in which cell types, MYC is induced. Using immunohistochemistry (IHC) to localize MYC expression in Lo-MYC transgenic mice, we show that morphological and molecular alterations characteristic of high grade PIN arise in luminal epithelial cells as soon as MYC overexpression is detected. These changes include increased nuclear and nucleolar size and large scale chromatin remodeling. Mouse PIN cells retained a columnar architecture and abundant cytoplasm and appeared as either a single layer of neoplastic cells or as pseudo-stratified/multilayered structures with open glandular lumina—features highly analogous to human high grade PIN. Also using IHC, we show that the onset of MYC overexpression and PIN development coincided precisely with decreased expression of the homeodomain transcription factor and tumor suppressor, Nkx3.1. Virtually all normal appearing prostate luminal cells expressed high levels of Nkx3.1, but all cells expressing MYC in PIN lesions showed marked reductions in Nkx3.1, implicating MYC as a key factor that represses Nkx3.1 in PIN lesions. To determine the effects of less pronounced overexpression of MYC we generated a new line of mice expressing MYC in the prostate under the transcriptional control of the mouse Nkx3.1 control region. These “Super-Lo-MYC” mice also developed PIN, albeit a less aggressive form. We also identified a histologically defined intermediate step in the progression of mouse PIN into invasive adenocarcinoma. These lesions are characterized by a loss of cell polarity, multi-layering, and cribriform formation, and by a “paradoxical” increase in Nkx3.1 protein. Similar histopathological changes occurred in Hi-MYC mice, albeit with accelerated kinetics. Our results using IHC provide novel insights that support the contention that MYC overexpression is sufficient to transform prostate luminal epithelial cells into PIN cells in vivo. We also identified a novel histopathologically identifiable intermediate step prior to invasion that should facilitate studies of molecular pathway alterations occurring during early progression of prostatic adenocarcinomas

    Effects of fluoxetine on functional outcomes after acute stroke (FOCUS): a pragmatic, double-blind, randomised, controlled trial

    Get PDF
    Background Results of small trials indicate that fluoxetine might improve functional outcomes after stroke. The FOCUS trial aimed to provide a precise estimate of these effects. Methods FOCUS was a pragmatic, multicentre, parallel group, double-blind, randomised, placebo-controlled trial done at 103 hospitals in the UK. Patients were eligible if they were aged 18 years or older, had a clinical stroke diagnosis, were enrolled and randomly assigned between 2 days and 15 days after onset, and had focal neurological deficits. Patients were randomly allocated fluoxetine 20 mg or matching placebo orally once daily for 6 months via a web-based system by use of a minimisation algorithm. The primary outcome was functional status, measured with the modified Rankin Scale (mRS), at 6 months. Patients, carers, health-care staff, and the trial team were masked to treatment allocation. Functional status was assessed at 6 months and 12 months after randomisation. Patients were analysed according to their treatment allocation. This trial is registered with the ISRCTN registry, number ISRCTN83290762. Findings Between Sept 10, 2012, and March 31, 2017, 3127 patients were recruited. 1564 patients were allocated fluoxetine and 1563 allocated placebo. mRS data at 6 months were available for 1553 (99·3%) patients in each treatment group. The distribution across mRS categories at 6 months was similar in the fluoxetine and placebo groups (common odds ratio adjusted for minimisation variables 0·951 [95% CI 0·839–1·079]; p=0·439). Patients allocated fluoxetine were less likely than those allocated placebo to develop new depression by 6 months (210 [13·43%] patients vs 269 [17·21%]; difference 3·78% [95% CI 1·26–6·30]; p=0·0033), but they had more bone fractures (45 [2·88%] vs 23 [1·47%]; difference 1·41% [95% CI 0·38–2·43]; p=0·0070). There were no significant differences in any other event at 6 or 12 months. Interpretation Fluoxetine 20 mg given daily for 6 months after acute stroke does not seem to improve functional outcomes. Although the treatment reduced the occurrence of depression, it increased the frequency of bone fractures. These results do not support the routine use of fluoxetine either for the prevention of post-stroke depression or to promote recovery of function. Funding UK Stroke Association and NIHR Health Technology Assessment Programme
    corecore