1,802 research outputs found
A rare case of leiomyoma of the bladder
Bladder leiomyoma is a benign tumour of the bladder and constitute <0.5% of all bladder tumors. We report a clinical case of a 51âyearâold female who presented with with symptomatic bladder leiomyoma. An ultrasound examination showed well-defined bladder leiomyoma in the right posterior bladder wall, which was excised through a transurethral resection. The pathologic diagnosis was bladder leiomyoma
Path-Fault-Tolerant Approximate Shortest-Path Trees
Let be an -nodes non-negatively real-weighted undirected graph.
In this paper we show how to enrich a {\em single-source shortest-path tree}
(SPT) of with a \emph{sparse} set of \emph{auxiliary} edges selected from
, in order to create a structure which tolerates effectively a \emph{path
failure} in the SPT. This consists of a simultaneous fault of a set of at
most adjacent edges along a shortest path emanating from the source, and it
is recognized as one of the most frequent disruption in an SPT. We show that,
for any integer parameter , it is possible to provide a very sparse
(i.e., of size ) auxiliary structure that carefully
approximates (i.e., within a stretch factor of ) the true
shortest paths from the source during the lifetime of the failure. Moreover, we
show that our construction can be further refined to get a stretch factor of
and a size of for the special case , and that it can be
converted into a very efficient \emph{approximate-distance sensitivity oracle},
that allows to quickly (even in optimal time, if ) reconstruct the
shortest paths (w.r.t. our structure) from the source after a path failure,
thus permitting to perform promptly the needed rerouting operations. Our
structure compares favorably with previous known solutions, as we discuss in
the paper, and moreover it is also very effective in practice, as we assess
through a large set of experiments.Comment: 21 pages, 3 figures, SIROCCO 201
A 3D environment to rebuild virtually the so-called Augusteum in Herculaneum
Computer graphics and three-dimensional modelling techniques have extended the possibilities of archaeologists in the creation of virtual reconstruction of ancient sites and monuments. Modern computational systems allow the implementation of computer-generated scenarios tailored on human cognitive capacities. Although Virtual Archaeology is not a novelty in the panorama of archaeological methods, there is no agreement among scholars on the minimal parameters necessary to virtually rebuild an ancient context, nor is there any requirement needed to guarantee the accuracy and the effectiveness of the final reconstruction; the strength of a model is based mainly on the capacity of the archaeologist to check the final result in terms of comparison between interpretations and hypotheses. The paper aims at exploring how the archaeologists could perform their work in a computational laboratory thanks to shared 3D models. The case study selected is the recent virtual reconstruction of the so-called Basilica in Herculaneum, a monument - 250 years after its discovery - still largely unexplained. The building is completely buried by volcanic lava save for part of its entrance porch. It was extensively explored using tunnels and looted by its early excavators. Different scholars have rebuilt the monument mainly on the basis of two plans, drawn in the 18th century, and few notes taken by the archaeologists during the exploration. The 3D model, carried out by integrating cad modelling with close-range photogrammetry, is intended to highlight some controversial parts of the reconstructions. Metadata associated to the digital replica describe the physical object and register all phases from data-acquisition to data-visualization in order to allow the validation of the model and the use or re-use of the digital resource
The Impact of Primary Versus Secondary Muscle-invasive Bladder Cancer at Diagnosis on the Response to Neoadjuvant Chemotherapy.
Background
There might be differential sensitivity to neoadjuvant chemotherapy (NAC) in patients with primary muscle-invasive bladder cancer (MIBC) in comparison to patients with secondary MIBC after a history of nonâmuscle-invasive disease.
Objective
To investigate pathologic response rates and survival associated with primary versus secondary MIBC among patients treated with cisplatin-based NAC for cT2â4N0M0 MIBC.
Design, setting, and participants
Oncologic outcomes were compared for 350 patients with primary MIBC and 64 with secondary MIBC treated with NAC and radical cystectomy between 1992 and 2021 at 11 academic centers. Genomic analyses were performed for 476 patients from the Memorial Sloan Kettering/The Cancer Genome Atlas cohort.
Outcome measurements and statistical analysis
The outcome measures were pathologic objective response (pOR; â¤ypT1 N0), pathologic complete response (pCR; ypT0 N0), overall mortality, and cancer-specific mortality.
Results and limitations
The primary MIBC group had higher pOR (51% vs 34%; p = 0.02) and pCR (33% vs 17%; p = 0.01) rates in comparison to the secondary MIBC group. On multivariable logistic regression analysis, primary MIBC was independently associated with both pOR (odds ratio [OR] 0.49, 95% confidence interval [CI] 0.26â0.87; p = 0.02) and pCR (OR 0.41, 95% CI 0.19â0.82; p = 0.02). However, on multivariable Cox regression analysis, primary MIBC was not associated with overall mortality (hazard ratio 1.70, 95% CI 0.84â3.44; p = 0.14) or cancer-specific mortality (hazard ratio 1.50, 95% CI 0.66â3.40; p = 0.3). Genomic analyses revealed a significantly higher ERCC2 mutation rate in primary MIBC than in secondary MIBC (12.4% vs 1.3%; p < 0.001).
Conclusions
Patients with primary MIBC have better pathologic response rates to NAC in comparison to patients with secondary MIBC. Chemoresistance might be related to the different genomic profile of primary versus secondary MIBC.
Patient summary
We investigated the treatment response to neoadjuvant chemotherapy (NAC; chemotherapy received before the primary course of treatment) and survival for patients with a primary diagnosis of muscle-invasive bladder cancer (MIBC) in comparison to patients with a history of nonâmuscle-invasive bladder cancer that progressed to MIBC. Patients with primary MIBC had a better response to NAC but this did not translate to better survival after accounting for other tumor characteristics.post-print824 K
Spectral geometry of -Minkowski space
After recalling Snyder's idea of using vector fields over a smooth manifold
as `coordinates on a noncommutative space', we discuss a two dimensional
toy-model whose `dual' noncommutative coordinates form a Lie algebra: this is
the well known -Minkowski space.
We show how to improve Snyder's idea using the tools of quantum groups and
noncommutative geometry.
We find a natural representation of the coordinate algebra of
-Minkowski as linear operators on an Hilbert space study its `spectral
properties' and discuss how to obtain a Dirac operator for this space.
We describe two Dirac operators. The first is associated with a spectral
triple. We prove that the cyclic integral of M. Dimitrijevic et al. can be
obtained as Dixmier trace associated to this triple. The second Dirac operator
is equivariant for the action of the quantum Euclidean group, but it has
unbounded commutators with the algebra.Comment: 23 pages, expanded versio
Low-cost surveys of the <i>Domus</i> of Stallius Eros in Pompeii
In the framework of the Project 3D-ICONS (www.3dicons-project.eu), different large archaeological models were acquired in
Pompeii. In particular, the 3D Model of the House of Stallius Eros (Regio I, Insula VI, 13 - 14) was realized. This house conserves a
rich vertical stratigraphy covering a large chronological period and offers interesting information about the development of this side
of the ancient city. To implement a detailed survey of the house and to reconstruct the original structure of the domus, different types
of survey were carried out, in order to provide a complete 3D model of the house. Three data-acquisition methodologies were used
and their final results were compared in order to measure their accuracy, efficacy and velocity. At first, the domus was surveyed by
an electronical total station, then two different interventions with un-calibrated photogrammetry were planned. The paper presents
some preliminary results obtained by the three methodologies and the integration of the three models. The computational
environments reproducing the ancient Domus of Stallius Eros allows to propose new archaeological interpretations and hypothesis
about the reconstruction of the ancient House
Colorflow Studies in the ATLAS Boosted Higgs Boson Tagger
Enhancing the discrimination power to identify Higgs boson decay events into a pair of bottom quarks in the boosted regime is of significant importance within the ATLAS experiment at the Large Hadron Collider (LHC). Effectively iden- tifying this specific process enhances the collected sample of Higgs boson production events, hence reducing the statistical uncertainties in the determination of the prop- erties of this particle. The production of the Higgs boson in the so-called boosted regime, i.e., with large transverse momentum with respect to the beam direction, results in the final-state quark pair being highly collimated, reconstructed as a sin- gle large-radius jet (LargeR-jet). Discriminating between these signal events and the background is a rather challenging task. To enhance the discriminative power between signal and background events, it is possible to employ variables that are sensitive to the SU(3) color representation of the decaying particle, which produces the LargeR-jet. This study has demonstrated how the new ATLAS boosted Higgs boson tagger (GN2X) appears to autonomously utilize color information from the jet, showcasing its robustness, thus offering valuable insights for future analyses within the collaboration focusing on such events
Fully-dynamic Approximation of Betweenness Centrality
Betweenness is a well-known centrality measure that ranks the nodes of a
network according to their participation in shortest paths. Since an exact
computation is prohibitive in large networks, several approximation algorithms
have been proposed. Besides that, recent years have seen the publication of
dynamic algorithms for efficient recomputation of betweenness in evolving
networks. In previous work we proposed the first semi-dynamic algorithms that
recompute an approximation of betweenness in connected graphs after batches of
edge insertions.
In this paper we propose the first fully-dynamic approximation algorithms
(for weighted and unweighted undirected graphs that need not to be connected)
with a provable guarantee on the maximum approximation error. The transfer to
fully-dynamic and disconnected graphs implies additional algorithmic problems
that could be of independent interest. In particular, we propose a new upper
bound on the vertex diameter for weighted undirected graphs. For both weighted
and unweighted graphs, we also propose the first fully-dynamic algorithms that
keep track of such upper bound. In addition, we extend our former algorithm for
semi-dynamic BFS to batches of both edge insertions and deletions.
Using approximation, our algorithms are the first to make in-memory
computation of betweenness in fully-dynamic networks with millions of edges
feasible. Our experiments show that they can achieve substantial speedups
compared to recomputation, up to several orders of magnitude
The risk of falling
Abstract: In the late 1960s, much interest was raised in regard to biomedical applications of various ceramic materials. A little bit later, such materials were named bioceramics. This review is limited to bioceramics prepared from calcium orthophosphates only, which belong to the categories of bioactive and bioresorbable compounds. There have been a number of important advances in this field during the past 30â40 years. Namely, by structural and compositional control, it became possible to choose whether calcium orthophosphate bioceramics were biologically stable once incorporated within the skeletal structure or whether they were resorbed over time. At the turn of the millennium, a new concept of calcium orthophosphate bioceramicsâwhich is able to promote regeneration of bonesâwas developed. Presently, calcium orthophosphate bioceramics are available in the form of particulates, blocks, cements, coatings, customized designs for specific applications and as injectable composites in a polymer carrier. Current biomedical applications include artificial replacements for hips, knees, teeth, tendons and ligaments, as well as repair for periodontal disease, maxillofacial reconstruction, augmentation and stabilization of the jawbone, spinal fusion and bone fillers after tumor surgery. Exploratory studies demonstrate potential applications of calcium orthophosphate bioceramics as scaffolds, drug delivery systems, as well as carriers of growth factors, bioactive peptides and/or various types of cells for tissue engineering purposes
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