| 441. |
- Fernández-Pello, Sergio, et al.
(författare)
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Management of Sporadic Renal Angiomyolipomas : A Systematic Review of Available Evidence to Guide Recommendations from the European Association of Urology Renal Cell Carcinoma Guidelines Panel
- 2020
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Ingår i: European Urology Oncology. - : Elsevier. - 2588-9311. ; 3:1, s. 57-72
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Forskningsöversikt (refereegranskat)abstract
- Context: Little is known about the natural history of sporadic angiomyolipomas (AMLs); there is uncertainty regarding the indications of treatment and treatment options. Objective: To evaluate the indications, effectiveness, harms, and follow-up of different management modalities for sporadic AML to provide guidance for clinical practice. Evidence acquisition: A systematic review of the literature was undertaken, incorporating Medline, Embase, and the Cochrane Library (from 1 January 1990 to 30 June 2017), in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. No restriction on study design was imposed. Patients with sporadic AML were included. The main interventions included active surveillance, surgery (nephron-sparing surgery and radical nephrectomy), selective arterial embolisation, and percutaneous or laparoscopic thermal ablations (radiofrequency, microwaves, or cryoablation). The outcomes included indications for active treatment, AML growth rate, AML recurrence rate, risk of bleeding, post-treatment renal function, adverse events of treatments, and modalities of followup. Risk of bias assessment was performed using standard Cochrane methods. Evidence synthesis: Among 2704 articles identified, 43 were eligible for inclusion (zero randomised controlled trials, nine nonrandomised comparative retrospective studies, and 34 single-arm case series). Most studies were retrospective and uncontrolled, and had a moderate to high risk of bias. Conclusions: In active surveillance series, spontaneous bleeding was reported in 2% of patients and active treatment was undertaken in 5%. Active surveillance is the most chosen option in 48% of the cases, followed by surgery in 31% and selective arterial embolisation in 17% of the cases. Selective arterial embolisation appeared to reduce AML volume but required secondary treatment in 30% of the cases. Surgery (particularly nephron-sparing surgery) was the most effective treatment in terms of recurrence and need for secondary procedures. Thermal ablation was an infrequent option. The association between AML size and the risk of bleeding remained unclear; as such the traditional 4-cm cut-off should not per se trigger active treatment. In spite of the limitations and uncertainties relating to the evidence base, the findings may be used to guide and inform clinical practice, until more robust data emerge. Patient summary: Sporadic angiomyolipoma (AML) is a benign tumour of the kidney consisting of a mixture of blood vessels, fat, and muscle. Large tumours may have a risk of spontaneous bleeding. However, the size beyond which these tumours need to be treated remains unclear. Most small AMLs can be monitored without any active treatment. For those who need treatment, options include surgical removal of the tumour or stopping its blood supply (selective embolisation). Surgery has a lower recurrence rate and lower need for a repeat surgical procedure.
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| 442. |
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| 443. |
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| 444. |
- Furukawa, Toshi A., et al.
(författare)
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Initial severity of depression and efficacy of cognitive-behavioural therapy: individual-participant data meta-analysis of pill-placebo-controlled trials
- 2017
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Ingår i: British Journal of Psychiatry. - : ROYAL COLLEGE OF PSYCHIATRISTS. - 0007-1250 .- 1472-1465. ; 210:3, s. 190-196
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Forskningsöversikt (refereegranskat)abstract
- Background The influence of baseline severity has been examined for antidepressant medications but has not been studied properly for cognitive behavioural therapy (CBT) in comparison with pill placebo. Aims To synthesise evidence regarding the influence of initial severity on efficacy of CBT from all randomised controlled trials (RCTs) in which CBT, in face-to-face individual or group format, was compared with pill-placebo control in adults with major depression. Method A systematic review and an individual-participant data meta-analysis using mixed models that included trial effects as random effects. We used multiple imputation to handle missing data. Results We identified five RCTs, and we were given access to individual-level data (n=509) for all five. The analyses revealed that the difference in changes in Hamilton Rating Scale for Depression between CBT and pill placebo was not influenced by baseline severity (interaction P=0.43). Removing the non-significant interaction term from the model, the difference between CBT and pill placebo was a standardised mean difference of 0.22 (95% CI 0.42 to 0.02, P=0.03, l(2)=0%). Conclusions Patients suffering from major depression can expect as much benefit from CBT across the wide range of baseline severity. This finding can help inform individualised treatment decisions by patients and their clinicians.
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| 445. |
- Gaengel, K., et al.
(författare)
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The Sphingosine-1-Phosphate Receptor S1PR1 Restricts Sprouting Angiogenesis by Regulating the Interplay between VE-Cadherin and VEGFR2
- 2012
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Ingår i: Developmental Cell. - : Elsevier BV. - 1534-5807 .- 1878-1551. ; 23:3, s. 587-599
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Tidskriftsartikel (refereegranskat)abstract
- Angiogenesis, the process by which new blood vessels arise from preexisting ones, is critical for embryonic development and is an integral part of many disease processes. Recent studies have provided detailed information on how angiogenic sprouts initiate, elongate, and branch, but less is known about how these processes cease. Here, we show that S1PR1, a receptor for the blood-borne bioactive lipid sphingosine-1-phosphate (S1P), is critical for inhibition of angiogenesis and acquisition of vascular stability. Loss of S1PR1 leads to increased endothelial cell sprouting and the formation of ectopic vessel branches. Conversely, S1PR1 signaling inhibits angiogenic sprouting and enhances cell-to-cell adhesion. This correlates with inhibition of vascular endothelial growth factor-A (VEGF-A)-induced signaling and stabilization of vascular endothelial (VE)-cadherin localization at endothelial junctions. Our data suggest that S1PR1 signaling acts as a vascular-intrinsic stabilization mechanism, protecting developing blood vessels against aberrant angiogenic responses.
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| 446. |
- Garcia, A. E., et al.
(författare)
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Direct air to ground communications for flying vehicles : Measurement and scaling study for 5g
- 2019
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Ingår i: IEEE 5G World Forum, 5GWF 2019 - Conference Proceedings. - : IEEE. - 9781728136271 ; , s. 310-315
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Konferensbidrag (refereegranskat)abstract
- Broadband connectivity in the sky for unmanned aerial vehicles (UAVs) and commercial aircraft is the next step toward the ambitious goal of connectivity anywhere. To achieve it, direct air-to-ground communications (DA2GC) is a more promising solution than satellite communications due to its lower latency and higher throughput capabilities. In this paper, we develop a DA2GC system with tilted up directional antennas at ground base station and perform a measurement campaign using a UAV at low altitudes to study the DA2GC link at a carrier frequency of 3.7 GHz in terms of signal-to-noise ratio and throughput. Our designed DA2GC system is a general setup that can enable new frequency spectrum and new applications for 5G implementation. We also scale the obtained results from the measurements to a scenario of an aircraft flying at an altitude of 13 km. We study the physical limits of current cellular networks and analyze link budget for the scaling. A maximum of 14 Mbps is achieved during the measurement campaign. By scaling the measurement results with existing communications techniques such as carrier aggregation and techniques toward 5G such as higher antenna gains due to beamforming, extrapolated throughput could reach up to 257 Mbps with a maximum inter-site distance of 200 km due to limitations of current cellular networks. These results show that cellular networks with communication techniques toward 5G can be utilized for providing high-capacity connectivity for current aircraft at high altitudes as well as next-generation flying vehicles at low altitudes.
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| 447. |
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| 448. |
- Hahn, S., et al.
(författare)
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Spectral transfer from phase to intensity in Fresnel diffraction
- 2016
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Ingår i: PHYSICAL REVIEW A. - : American Physical Society. - 2469-9926. ; 93:5
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Tidskriftsartikel (refereegranskat)abstract
- We analyze theoretically and investigate experimentally the transfer of phase to intensity power spectra of spatial frequencies through free-space Fresnel diffraction. Depending on lambda z (where lambda is the wavelength and z is the free-space propagation distance) and the phase-modulation strength S, we demonstrate that for multiscale and broad phase spectra critical behavior transmutes a quasilinear to a nonlinear diffractogram except for low frequencies. On the contrary, a single-scale and broad phase spectrum induces a critical transition in the diffractogram at low frequencies. In both cases, identifying critical behavior encoded in the intensity power spectra is of fundamental interest because it exhibits the limits of perturbative power counting but also guides resolution and contrast optimization in propagation-based, single-distance, phase-contrast imaging, given certain dose and coherence constraints.
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| 449. |
- Hassan, S. Fawad, et al.
(författare)
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Brane induced gravity, its ghost and the cosmological constant problem
- 2011
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :1, s. 020-
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Tidskriftsartikel (refereegranskat)abstract
- Brane Induced Gravity is regarded as a promising framework for addressing the cosmological constant problem, but it also suffers from a ghost instability for parameter values that make it phenomenologically viable. We carry out a detailed analysis of codimension > 2 models employing gauge invariant variables in a flat background approximation. It is argued that using instead a curved background sourced by the brane would not resolve the ghost issue, unless a very specific condition is satisfied (if satisfiable at all). As for other properties of the model, from an explicit analysis of the 4-dimensional graviton propagator we extract a mass, a decay width and a momentum dependent modification of the gravitational coupling for the spin 2 mode. In the flat space approximation, the mass of the problematic spin 0 ghost is instrumental in filtering out a brane cosmological constant. The mass replaces a background curvature that would have had the same function. The optical theorem is used to demonstrate the suppression of graviton leakage into the uncompactified bulk. Then, we derive the 4-dimensional effective action for gravity and show that general covariance is spontaneously broken by the bulk-brane setup. This provides a natural realization of the gravitational Higgs mechanism. We also show that the addition of extrinsic curvature dependent terms has no bearing on linearized brane gravity.
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| 450. |
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