824 research outputs found

    Ethnicity and prostate cancer: The way to solve the screening problem?

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    In their analysis in BMC Medicine, Lloyd et al. provide individual patient lifetime risks of prostate cancer diagnosis and prostate cancer death stratified by ethnicity. This easy to understand information is helpful for men to decide whether to start prostate-specific antigen testing (i.e. screening). A higher lifetime risk of prostate cancer death in some ethnic groups is not automatically a license to start screening. The potential benefit in the form of reducing metastases and death should still be weighed against the potential risk of over diagnosis. In case of ethnicity, this harm-to-benefit ratio does not differ between groups. Stratifying men for screening based on ethnicity is therefore not optimal and will not solve the current screening problem. Other methods for risk-stratifying men have been proven to produce a more optimal harm-to-benefit ratio

    Structural Invariance of Sunspot Umbrae Over the Solar Cycle: 1993-2004

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    Measurements of maximum magnetic flux, minimum intensity, and size are presented for 12 967 sunspot umbrae detected on the NASA/NSO spectromagnetograms between 1993 and 2004 to study umbral structure and strength during the solar cycle. The umbrae are selected using an automated thresholding technique. Measured umbral intensities are first corrected for a confirming observation of umbral limb-darkening. Log-normal fits to the observed size distribution confirm that the size spectrum shape does not vary with time. The intensity-magnetic flux relationship is found to be steady over the solar cycle. The dependence of umbral size on the magnetic flux and minimum intensity are also independent of cycle phase and give linear and quadratic relations, respectively. While the large sample size does show a low amplitude oscillation in the mean minimum intensity and maximum magnetic flux correlated with the solar cycle, this can be explained in terms of variations in the mean umbral size. These size variations, however, are small and do not substantiate a meaningful change in the size spectrum of the umbrae generated by the Sun. Thus, in contrast to previous reports, the observations suggest the equilibrium structure, as testified by the invariant size-magnetic field relationship, as well as the mean size (i.e. strength) of sunspot umbrae do not significantly depend on solar cycle phase.Comment: 17 pages, 6 figures. Published in Solar Physic

    Magnetically actuated glaucoma drainage device for regulating intraocular pressure after implantation

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    The key risk factor for glaucoma is increased intraocular pressure (IOP). Glaucoma drainage devices implanted in the eye can reduce IOP and thus stop disease progression. However, most devices currently used in clinical practice are passive and do not allow for postsurgical IOP control, which may result in serious complications such as hypotony (i.e., excessively low IOP). To enable noninvasive IOP control, we demonstrate a novel, miniature glaucoma implant that will enable the repeated adjustment of the hydrodynamic resistance after implantation. This is achieved by integrating a magnetic microvalve containing a micropencil-shaped plug that is moved using an external magnet, thereby opening or closing fluidic channels. The microplug is made from biocompatible poly(styrene-block-isobutylene-block-styrene) (SIBS) containing iron microparticles. The complete implant consists of an SIBS drainage tube and a housing element containing the microvalve and fabricated with hot embossing using femtosecond laser-machined glass molds. Using in vitro and ex vivo microfluidic experiments, we demonstrate that when the microvalve is closed, it can provide sufficient hydrodynamic resistance to overcome hypotony. Valve function is repeatable and stable over time. Due to its small size, our implant is a promising, safe, easy-to-implant, minimally invasive glaucoma surgery device. [Figure not available: see fulltext.]</p

    Long-term follow-up after active surveillance or curative treatment: quality-of-life outcomes of men with low-risk prostate cancer

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    Purpose: To compare long-term (4–10 years) quality of life (QoL) of men with low-risk prostate cancer (PCa) treated by different modalities and a reference group without PCa. Methods: In this cross-sectional study, four groups were sent a one-time QoL-questionnaire; PCa patients (1) following the structured Prostate cancer Research International Active Surveillance protocol, (2) who underwent radical prostatectomy (RP) in the context of t

    Research needs for optimising wastewater-based epidemiology monitoring for public health protection

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    Wastewater-based epidemiology (WBE) is an unobtrusive method used to observe patterns in illicit drug use, poliovirus, and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The pandemic and need for surveillance measures have led to the rapid acceleration of WBE research and development globally. With the infrastructure available to monitor SARS-CoV-2 from wastewater in 58 countries globally, there is potential to expand targets and applications for public health protection, such as other viral pathogens, antimicrobial resistance (AMR), pharmaceutical consumption, or exposure to chemical pollutants. Some applications have been explored in academic research but are not used to inform public health decision-making. We reflect on the current knowledge of WBE for these applications and identify barriers and opportunities for expanding beyond SARS-CoV-2. This paper critically reviews the applications of WBE for public health and identifies the important research gaps for WBE to be a useful tool in public health. It considers possible uses for pathogenic viruses, AMR, and chemicals. It summarises the current evidence on the following: (1) the presence of markers in stool and urine; (2) environmental factors influencing persistence of markers in wastewater; (3) methods for sample collection and storage; (4) prospective methods for detection and quantification; (5) reducing uncertainties; and (6) further considerations for public health use

    Sarcomania? The Inapplicability of Sarcopenia Measurement in Predicting Incisional Hernia Development

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    Background: Incisional hernia is a frequent complication after abdominal surgery. A risk factor for incisional hernia, related to body composition, is obesity. Poor skeletal muscle mass might also be a risk factor, as it may result in weakness of the abdominal wall. However, it remains unknown if sarcopenia (i.e. low skeletal muscle mass) is a risk factor for incisional hernia. Therefore, this study aims to investigate whether a relation between sarcopenia and incisional hernia exists. Methods: Patients from the STITCH trial, who underwent elective midline laparotomy, were included. Computed tomography examinations performed within 3 months preoperatively were used to measure the skeletal muscle index (SMI; cm2/m2). Primarily, SMI measured continuously, sarcopenia based on previously described cut-off values for the SMI, and sarcopenia as the lowest gender-specific SMI quartile were assessed as measures to predict incisional hernia occurrence. Secondary, the association between these three measures and post-operative complications was investigated. Results: In total, 283 patients (45.2% male; mean age 63.7 years; mean BMI 25.36 kg/m2) were included, of whom 52 (18%) devel

    Facial onset sensory and motor neuronopathy: new cases, cognitive changes and pathophysiology

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    Purpose of review To improve our clinical understanding of facial onset sensory and motor neuronopathy (FOSMN). Recent findings We identified 29 new cases and 71 literature cases, resulting in a cohort of 100 patients with FOSMN. During follow-up, cognitive and behavioral changes became apparent in 8 patients, suggesting that changes within the spectrum of frontotemporal dementia (FTD) are a part of the natural history of FOSMN. Another new finding was chorea, seen in 6 cases. Despite reports of autoantibodies, there is no consistent evidence to suggest an autoimmune pathogenesis. Four of 6 autopsies had TAR DNA-binding protein (TDP) 43 pathology. Seven cases had genetic mutations associated with neurodegenerative diseases. Summary FOSMN is a rare disease with a highly characteristic onset and pattern of disease progression involving initial sensory disturbances, followed by bulbar weakness with a cranial to caudal spread of pathology. Although not conclusive, the balance of evidence suggests that FOSMN is most likely to be a TDP-43 proteinopathy within the amyotrophic lateral sclerosis–FTD spectrum

    Sterols sense swelling in lipid bilayers

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    In the mimetic membrane system of phosphatidylcholine bilayers, thickening (pre-critical behavior, anomalous swelling) of the bilayers is observed, in the vicinity of the main transition, which is non-linear with temperature. The sterols cholesterol and androsten are used as sensors in a time-resolved simultaneous small- and wide angle x-ray diffraction study to investigate the cause of the thickening. We observe precritical behavior in the pure lipid system, as well as with sterol concentrations less than 15%. To describe the precritical behavior we introduce a theory of precritical phenomena.The good temperature resolution of the data shows that a theory of the influence of fluctuations needs modification. The main cause of the critical behavior appears to be a changing hydration of the bilayer.Comment: 11 pages, 7 ps figures included, to appear in Phys.Rev.

    Rule-based versus probabilistic selection for active surveillance using three definitions of insignificant prostate cancer

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    To study whether probabilistic selection by the use of a nomogram could improve patient selection for active surveillance (AS) compared to the various sets of rule-based AS inclusion criteria currently used. We studied Dutch and Swedish patients participating in the European Randomized study of Screening for Prostate Cancer (ERSPC). We explored which men who were initially diagnosed with cT1-2, Gleason 6 (Gleason pattern a parts per thousand currency sign3 + 3) had histopathological indolent PCa at RP [defined as pT2, Gleason pattern a parts per thousand currency sign3 and tumour volume (TV) a parts per thousand currency sign0.5 or TV a parts per thousand currency sign 1.3 ml, and TV no part of criteria (NoTV)]. Rule-based selection was according to the Prostate cancer Research International: Active Surveillance (PRIAS), Klotz, and Johns Hopkins criteria. An existing nomogram to define probability-based selection for AS was refitted for the TV1.3 and NoTV indolent PCa definitions. 619 of 864 men undergoing RP had cT1-2, Gleason 6 disease at diagnosis and were analysed. Median follow-up was 8.9 years. 229 (37 %), 356 (58 %), and 410 (66 %) fulfilled the TV0.5, TV1.3, and NoTV indolent PCa criteria at RP. Discriminating between indolent and significant disease according to area under the curve (AUC) was: TV0.5: 0.658 (PRIAS), 0.523 (Klotz), 0.642 (Hopkins), 0.685 (nomogram). TV1.3: 0.630 (PRIAS), 0.550 (Klotz), 0.615 (Hopkins), 0.646 (nomogram). NoTV: 0.603 (PRIAS), 0.530 (Klotz), 0.589 (Hopkins), 0.608 (nomogram). The performance of a nomogram, the Johns Hopkins, and PRIAS rule-based criteria are comparable. Because the nomogram allows individual trade-offs, it could be a good alternative to rigid rule-based criteria

    Constraining primordial non-Gaussianity with cosmological weak lensing: shear and flexion

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    We examine the cosmological constraining power of future large-scale weak lensing surveys on the model of \emph{Euclid}, with particular reference to primordial non-Gaussianity. Our analysis considers several different estimators of the projected matter power spectrum, based on both shear and flexion, for which we review the covariances and Fisher matrices. The bounds provided by cosmic shear alone for the local bispectrum shape, marginalized over σ8\sigma_8, are at the level of ΔfNL∼100\Delta f_\mathrm{NL} \sim 100. We consider three additional bispectrum shapes, for which the cosmic shear constraints range from ΔfNL∼340\Delta f_\mathrm{NL}\sim 340 (equilateral shape) up to ΔfNL∼500\Delta f_\mathrm{NL}\sim 500 (orthogonal shape). The competitiveness of cosmic flexion constraints against cosmic shear ones depends on the galaxy intrinsic flexion noise, that is still virtually unconstrained. Adopting the very high value that has been occasionally used in the literature results in the flexion contribution being basically negligible with respect to the shear one, and for realistic configurations the former does not improve significantly the constraining power of the latter. Since the flexion noise decreases with decreasing scale, by extending the analysis up to ℓmax=20,000\ell_\mathrm{max} = 20,000 cosmic flexion, while being still subdominant, improves the shear constraints by ∼10\sim 10% when added. However on such small scales the highly non-linear clustering of matter and the impact of baryonic physics make any error estimation uncertain. By considering lower, and possibly more realistic, values of the flexion intrinsic shape noise results in flexion constraining power being a factor of ∼2\sim 2 better than that of shear, and the bounds on σ8\sigma_8 and fNLf_\mathrm{NL} being improved by a factor of ∼3\sim 3 upon their combination. (abridged)Comment: 30 pages, 4 figures, 4 tables. To appear on JCA
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