791 research outputs found

    What is the effect of MRI with targeted biopsies on the rate of patients discontinuing active surveillance? A reflection of the use of MRI in the PRIAS study

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    Background The reduction of overtreatment by active surveillance (AS) is limited in patients with low-risk prostate cancer (PCa) due to high rates of patients switching to radical treatment. MRI improves biopsy accuracy and could therewith affect inclusion in or continuation of AS. We aim to assess the effect of MRI with target biopsies on the total rate of patients discontinuing AS, and in particular discontinuation due to Grade Group (GG) reclassification. Methods Three subpopulations included in the prospective PRIAS study with GG 1 were studied. Group A consists of patients diagnosed before 2009 without MRI before or during AS. Group B consists of patients diagnosed without MRI, but all patients underwent MRI within 6 months after diagnosis. Group C consists of patients who underwent MRI before diagnosis and during follow-up. We used cumulative incidence curves to estimate the rates of discontinuation. Results In Group A (n = 500), the cumulative probability of discontinuing AS at 2 years is 27.5%; GG reclassification solely accounted for 6.9% of the discontinuation. In Group B (n = 351) these numbers are 30.9 and 22.8%, and for Group C (n = 435) 24.2 and 13.4%. The three groups were not randomized, however, baseline characteristics are highly comparable. Conclusions Performing an MRI before starting AS reduces the cumulative probability of discontinuing AS at 2 years. Performing an MRI after already being on AS increases the cumulative probability of discontinuing AS in comparison to not performing an MRI, especially because of an increase in GG reclassification. These results suggest that the use of MRI could lead to more patients being considered unsuitable for AS. Considering the excellent long-term cancer-specific survival of AS before the MRI era, the increased diagnostic accuracy of MRI could potentially lead to more overtreatment if definitions and treatment options of significant PCa are not adapted.Peer reviewe

    Resolution of Biphasic Binding of the Opioid Antagonist Naltrexone in Brain Membranes

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    In synaptosomal membranes from rat brain cortex, in the presence of 150 m M NaC1, the opioid antagonist [ 3 H] naltrexone bound to two populations of receptor sites with affinities of 0.27 and 4.3 n M , respectively. Guanosine-5′-(3-thiotriphosphate) had little modulating effect and did not alter the biphasic nature of ligand binding. On the other hand, receptor-selective opioids differentially inhibited the two binding components of [ 3 H] naltrexone. As shown by nonlinear least-squares analysis, the Μ opioids Tyr-D-Ala-Gly-(Me)Phe-Gly-ol or sufentanil abolished high-affinity [ 3 H] naltrexone binding, whereas the Δ-selective ligands [D- Pen 2 , D-Pen 5 ] enkephalin, ICI 174, 864, and oxymorphindole inhibited and eventually eliminated the low-affinity component in a concentration-dependent manner. These results indicate that, in contrast to the guanine nucleotide-sensitive biphasic binding of opioid-alkaloid agonists, the heterogeneity of naltrexone binding in brain membranes reflects ligand interaction with different opioid-receptor types.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66340/1/j.1471-4159.1991.tb08288.x.pd

    Generalized Interpolation Material Point Approach to High Melting Explosive with Cavities Under Shock

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    Criterion for contacting is critically important for the Generalized Interpolation Material Point(GIMP) method. We present an improved criterion by adding a switching function. With the method dynamical response of high melting explosive(HMX) with cavities under shock is investigated. The physical model used in the present work is an elastic-to-plastic and thermal-dynamical model with Mie-Gr\"uneissen equation of state. We mainly concern the influence of various parameters, including the impacting velocity vv, cavity size RR, etc, to the dynamical and thermodynamical behaviors of the material. For the colliding of two bodies with a cavity in each, a secondary impacting is observed. Correspondingly, the separation distance DD of the two bodies has a maximum value DmaxD_{\max} in between the initial and second impacts. When the initial impacting velocity vv is not large enough, the cavity collapses in a nearly symmetric fashion, the maximum separation distance DmaxD_{\max} increases with vv. When the initial shock wave is strong enough to collapse the cavity asymmetrically along the shock direction, the variation of DmaxD_{\max} with vv does not show monotonic behavior. Our numerical results show clear indication that the existence of cavities in explosive helps the creation of ``hot spots''.Comment: Figs.2,4,7,11 in JPG format; Accepted for publication in J. Phys. D: Applied Physic

    Evaluation of diurnal responses of Tetradesmus obliquus under nitrogen limitation

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    Tetradesmus obliquus is an oleaginous microalga with high potential for triacylglycerol production. We characterized the biochemical composition and the transcriptional landscape of T. obliquus wild-type and the starchless mutant (slm1), adapted to 16:8 h light dark (LD) cycles under nitrogen limitation. In comparison to the nitrogen replete conditions, the diurnal RNA samples from both strains also displayed a cyclic pattern, but with much less variation which could be related to a reduced transcription activity in at least the usually highly active processes. During nitrogen limitation, the wild-type continued to use starch as the preferred storage compound to store energy and carbon. Starch was accumulated to an average content of 0.25 g·gDW−1, which is higher than the maximum observed under nitrogen replete conditions. Small oscillations were observed, indicating that starch was being used as a diurnal energy storage compound, but to a lesser extent than under nitrogen replete conditions. For the slm1 mutant, TAG content was higher than for the wild-type (average steady state value was 0.26 g·gDW−1 for slm1 compared to 0.06 g·gDW−1 for the wild-type). Despite the higher TAG content in the slm1, the conversion efficiency of photons into biomass components for the slm1 was only half of the one obtained for the wild-type. This is related to the observed decrease in biomass productivity (from 1.29 gDW·L−1·day−1 for the wild-type to 0.52 gDW·L−1·day−1 for the slm1). While the transcriptome of slm1 displayed clear signs of energy generation by degrading TAG and amino-acids during the dark period, no significant variation of these metabolites could be measured. When looking through the diurnal cycle, the photosynthetic efficiency was lower for the slm1 mutant compared to the wild-type especially during the second half of the light period, where starch accumulation occurred in the wild-type.publishedVersionPaid Open Acces

    Apixaban versus no anticoagulation after anticoagulation-associated intracerebral haemorrhage in patients with atrial fibrillation in the Netherlands (APACHE-AF):a randomised, open-label, phase 2 trial

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    Background In patients with atrial fibrillation who survive an anticoagulation-associated intracerebral haemorrhage, a decision must be made as to whether restarting or permanently avoiding anticoagulation is the best long-term strategy to prevent recurrent stroke and other vascular events. In APACHE-AF, we aimed to estimate the rates of non-fatal stroke or vascular death in such patients when treated with apixaban compared with when anticoagulation was avoided, to inform the design of a larger trial. Methods APACHE-AF was a prospective, randomised, open-label, phase 2 trial with masked endpoint assessment, done at 16 hospitals in the Netherlands. Patients who survived intracerebral haemorrhage while treated with anticoagulation for atrial fibrillation were eligible for inclusion 7-90 days after the haemorrhage. Participants also had a CHA2DS2-VASc score of at least 2 and a score on the modified Rankin scale (mRS) of 4 or less. Participants were randomly assigned (1:1) to receive oral apixaban (5 mg twice daily or a reduced dose of 2.5 mg twice daily) or to avoid anticoagulation (oral antiplatelet agents could be prescribed at the discretion of the treating physician) by a central computerised randomisation system, stratified by the intention to start or withhold antiplatelet therapy in participants randomised to avoiding anticoagulation, and minimised for age and intracerebral haemorrhage location. The primary outcome was a composite of non-fatal stroke or vascular death, whichever came first, during a minimum follow-up of 6 months, analysed using Cox proportional hazards modelling in the intention-to-treat population. APACHE-AF is registered with ClinicalTrials.gov (NCT02565693) and the Netherlands Trial Register (NL4395), and the trial is closed to enrolment at all participating sites. Findings Between Jan 15, 2015, and July 6, 2020, we recruited 101 patients (median age 78 years [IQR 73-83]; 55 [54%] were men and 46 [46%] were women; 100 [99%] were White and one [1%] was Black) a median of 46 days (IQR 21-74) after intracerebral haemorrhage. 50 were assigned to apixaban and 51 to avoid anticoagulation (of whom 26 [51%] started antiplatelet therapy). None were lost to follow-up. Over a median follow-up of 1.9 years (IQR 1.0-3.1; 222 person-years), non-fatal stroke or vascular death occurred in 13 (26%) participants allocated to apixaban (annual event rate 12.6% [95% CI 6.7-21.5]) and in 12 (24%) allocated to avoid anticoagulation (11.9% [95% CI 6.2-20.8]; adjusted hazard ratio 1.05 [95% CI 0.48-2.31]; p=0.90). Serious adverse events that were not outcome events occurred in 29 (58%) of 50 participants assigned to apixaban and 29 (57%) of 51 assigned to avoid anticoagulation. Interpretation Patients with atrial fibrillation who had an intracerebral haemorrhage while taking anticoagulants have a high subsequent annual risk of non-fatal stroke or vascular death, whether allocated to apixaban or to avoid anticoagulation. Our data underline the need for randomised controlled trials large enough to allow identification of subgroups in whom restarting anticoagulation might be either beneficial or hazardous. Copyright (C) 2021 Elsevier Ltd. All rights reserved

    MAX-DOAS measurements of HONO slant column densities during the MAD-CAT campaign: Inter-comparison, sensitivity studies on spectral analysis settings, and error budget

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    In order to promote the development of the passive DOAS technique the Multi Axis DOAS – Comparison campaign for Aerosols and Trace gases (MAD-CAT) was held at the Max Planck Institute for Chemistry in Mainz, Germany, from June to October 2013. Here, we systematically compare the differential slant column densities (dSCDs) of nitrous acid (HONO) derived from measurements of seven different instruments. We also compare the tropospheric difference of SCDs (delta SCD) of HONO, namely the difference of the SCDs for the non-zenith observations and the zenith observation of the same elevation sequence. Different research groups analysed the spectra from their own instruments using their individual fit software. All the fit errors of HONO dSCDs from the instruments with cooled large-size detectors are mostly in the range of 0.1 to 0.3  ×  1015 molecules cm−2 for an integration time of 1 min. The fit error for the mini MAX-DOAS is around 0.7  ×  1015 molecules cm−2. Although the HONO delta SCDs are normally smaller than 6  ×  1015 molecules cm−2, consistent time series of HONO delta SCDs are retrieved from the measurements of different instruments. Both fits with a sequential Fraunhofer reference spectrum (FRS) and a daily noon FRS lead to similar consistency. Apart from the mini-MAX-DOAS, the systematic absolute differences of HONO delta SCDs between the instruments are smaller than 0.63  ×  1015 molecules cm−2. The correlation coefficients are higher than 0.7 and the slopes of linear regressions deviate from unity by less than 16 % for the elevation angle of 1°. The correlations decrease with an increase in elevation angle. All the participants also analysed synthetic spectra using the same baseline DOAS settings to evaluate the systematic errors of HONO results from their respective fit programs. In general the errors are smaller than 0.3  ×  1015 molecules cm−2, which is about half of the systematic difference between the real measurements. The differences of HONO delta SCDs retrieved in the selected three spectral ranges 335–361, 335–373 and 335–390 nm are considerable (up to 0.57  ×  1015 molecules cm−2) for both real measurements and synthetic spectra. We performed sensitivity studies to quantify the dominant systematic error sources and to find a recommended DOAS setting in the three spectral ranges. The results show that water vapour absorption, temperature and wavelength dependence of O4 absorption, temperature dependence of Ring spectrum, and polynomial and intensity offset correction all together dominate the systematic errors. We recommend a fit range of 335–373 nm for HONO retrievals. In such fit range the overall systematic uncertainty is about 0.87  ×  1015 molecules cm−2, much smaller than those in the other two ranges. The typical random uncertainty is estimated to be about 0.16  ×  1015 molecules cm−2, which is only 25 % of the total systematic uncertainty for most of the instruments in the MAD-CAT campaign. In summary for most of the MAX-DOAS instruments for elevation angle below 5°, half daytime measurements (usually in the morning) of HONO delta SCD can be over the detection limit of 0.2  ×  1015 molecules cm−2 with an uncertainty of  ∼  0.9  ×  1015 molecules cm−2
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