| 1. |
- Hautmann, Richard E., et al.
(author)
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ICUD-EAU International Consultation on Bladder Cancer 2012: Urinary Diversion
- 2013
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In: European Urology. - : Elsevier BV. - 1873-7560 .- 0302-2838. ; 63:1, s. 67-80
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Research review (peer-reviewed)abstract
- Context: A summary of the 2nd International Consultation on Bladder Cancer recommendations on the reconstructive options after radical cystectomy (RC), their outcomes, and their complications. Objective: To review the literature regarding indications, surgical details, postoperative care, complications, functional outcomes, as well as quality-of-life measures of patients with different forms of urinary diversion (UD). Evidence acquisition: An English-language literature review of data published between 1970 and 2012 on patients with UD following RC for bladder cancer was undertaken. No randomized controlled studies comparing conduit diversion with neobladder or continent cutaneous diversion have been performed. Consequently, almost all studies used in this report are of level 3 evidence. Therefore, the recommendations given here are grade C only, meaning expert opinion delivered without a formal analysis. Evidence synthesis: Indications and patient selection criteria have significantly changed over the past 2 decades. Renal function impairment is primarily caused by obstruction. Complications such as stone formation, urine outflow, and obstruction at any level must be recognized early and treated. In patients with orthotopic bladder substitution, daytime and nocturnal continence is achieved in 85-90% and 60-80%, respectively. Continence is inferior in elderly patients with orthotopic reconstruction. Urinary retention remains significant in female patients, ranging from 7% to 50%. Conclusions: RC and subsequent UD have been assessed as the most difficult surgical procedure in urology. Significant disparity on how the surgical complications were reported makes it impossible to compare postoperative morbidity results. Complications rates overall following RC and UD are significant, and when strict reporting criteria are incorporated, they are much higher than previously published. Fortunately, most complications are minor (Clavien grade 1 or 2). Complications can occur up to 20 yr after surgery, emphasizing the need for lifelong monitoring. Evidence suggests an association between surgical volume and outcome in RC; the challenge of optimum care for elderly patients with comorbidities is best mastered at high-volume hospitals by high-volume surgeons. Preoperative patient information, patient selection, surgical techniques, and careful postoperative follow-up are the cornerstones to achieve good long-term results. (C) 2012 European Association of Urology. Published by Elsevier B. V. All rights reserved.
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| 2. |
- Pajola, Maurizio, et al.
(author)
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Aswan site on comet 67P/Churyumov-Gerasimenko : Morphology, boulder evolution, and spectrophotometry
- 2016
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 592
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Journal article (peer-reviewed)abstract
- Aims. We provide a detailed morphological analysis of the Aswan site on comet 67P/Churyumov-Gerasimenko (67P). We derive the size-frequency distribution of boulders >= 2 m and correlate this distribution with the gravitational slopes for the first time on a comet. We perform the spectral analysis of this region to understand if possible surface variegation is related to the different surface textures observable on the different units. Methods. We used two OSIRIS Narrow Angle Camera (NAC) image data sets acquired on September 19 and 22, 2014, with a scale of 0.5 m/px. Gravitational slopes derived from the 3D shape model of 67P were used to identify and interpret the different units of the site. By means of the high-resolution NAC data sets, boulders >= 2.0 m can be unambiguously identified and extracted using the software ArcGIS. Coregistered and photometrically corrected color cubes were used to perform the spectral analyses, and we retrieved the spectral properties of the Aswan units. Results. The high-resolution morphological map of the Aswan site (0.68 km(2)) shows that this site is characterized by four different units: fine-particle deposits located on layered terrains, gravitational accumulation deposits, taluses, and the outcropping layered terrain. Multiple lineaments are identified on the Aswan cliff, such as fractures, exposed layered outcrops, niches, and terraces. Close to the terrace margin, several arched features observed in plan view suggest that the margin progressively retreats as a result of erosion. The size-frequency of boulders >= 2 m in the entire study area has a power-law index of -3.9 +0.2/-0.3 (1499 boulders >= 2 m/km(2)), suggesting that the Aswan site is mainly dominated by gravitational events triggered by sublimation and/or thermal insolation weathering causing regressive erosion. The boulder size-frequency distribution versus gravitational slopes indicates that when higher gravitational slope terrains are considered, only boulders <= 10 m are identified, as well as steeper power-slope indices. In addition, no boulders >= 2 m are observed on slopes >= 50 degrees. This may indicate that larger blocks detached from a sublimating cliff cannot rest at these slopes and consequently fall down. The spectral analysis performed on the site shows that despite different morphologic units, no spectral differences appear in the multiple textures. This may confirm a redistribution of particles across the nucleus as a consequence of airfall, whether coming from Hapi or from the southern hemisphere when it is active during perihelion.
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| 3. |
- Sierks, Holger, et al.
(author)
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On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko
- 2015
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 347:6220
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Journal article (peer-reviewed)abstract
- Images from the OSIRIS scientific imaging system onboard Rosetta show that the nucleus of 67P/Churyumov-Gerasimenko consists of two lobes connected by a short neck. The nucleus has a bulk density less than half that of water. Activity at a distance from the Sun of >3 astronomical units is predominantly from the neck, where jets have been seen consistently. The nucleus rotates about the principal axis of momentum. The surface morphology suggests that the removal of larger volumes of material, possibly via explosive release of subsurface pressure or via creation of overhangs by sublimation, may be a major mass loss process. The shape raises the question of whether the two lobes represent a contact binary formed 4.5 billion years ago, or a single body where a gap has evolved via mass loss.
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| 4. |
- Vincent, Jean-Baptiste, et al.
(author)
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Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse
- 2015
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 523:7558, s. 63-66
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Journal article (peer-reviewed)abstract
- Pits have been observed on many cometary nuclei mapped by spacecraft(1-4). It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments(5,6) andmodels(7,8) cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts(8,9). Alternative mechanisms like explosive activity(10) have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.
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