204 research outputs found
A wire-loop technique for implantation of an iliac branched device in a patient with previous surgery for a ruptured abdominal aortic aneurysm
We described a modified technique for implanting a bridging stent-graft into an iliac branched device. A 79-year-old male who had received aortobiiliac synthetic graft surgery for a ruptured abdominal aortic aneurysm six months earlier was admitted to our unit for treatment of a left common iliac aneurysm involving the origin of the hypogastric artery. A standard technique was unsuccessful at implanting the bridging stent-graft, and therefore a wire-loop guidewire over the graft bifurcation was used to stabilize the contralateral sheaths and to complete the implantation. © Turkish Society of Radiology 2012
Impact of Temporal Features of Cattle Exchanges on the Size and Speed of Epidemic Outbreaks
International audienceDatabases recording cattle exchanges offer unique opportunities for a better understanding and fighting of disease spreading. Most studies model contacts with (sequences of) networks, but this approach neglects important dynamical features of exchanges, that are known to play a key role in spreading. We use here a fully dynamic modeling of contacts and empirically compare the spreading outbreaks obtained with it to the ones obtained with network approaches. We show that neglecting time information leads to significant overestimates of actual sizes of spreading cascades, and that these sizes are much more heterogeneous than generally assumed. Our approach also makes it possible to study the speed of spreading, and we show that the observed speeds vary greatly, even for a same cascade size
The network structure of visited locations according to geotagged social media photos
Businesses, tourism attractions, public transportation hubs and other points
of interest are not isolated but part of a collaborative system. Making such
collaborative network surface is not always an easy task. The existence of
data-rich environments can assist in the reconstruction of collaborative
networks. They shed light into how their members operate and reveal a potential
for value creation via collaborative approaches. Social media data are an
example of a means to accomplish this task. In this paper, we reconstruct a
network of tourist locations using fine-grained data from Flickr, an online
community for photo sharing. We have used a publicly available set of Flickr
data provided by Yahoo! Labs. To analyse the complex structure of tourism
systems, we have reconstructed a network of visited locations in Europe,
resulting in around 180,000 vertices and over 32 million edges. An analysis of
the resulting network properties reveals its complex structure.Comment: 8 pages, 3 figure
Efficacy of TachoSil® patches in controlling Dacron suture-hole bleeding after abdominal aortic aneurysm open repair
<p>Abstract</p> <p>Purpose</p> <p>The aim of this study is evaluate the efficacy of TachoSil<sup>® </sup>patches in controlling suture-hole bleeding after elective infrarenal abdominal aortic aneurysm (AAA) replacement with Dacron graft.</p> <p>Materials and methods</p> <p>Patients undergoing elective replacement of infrarenal AAA with Dacron grafts were prospectively randomized to TachoSil<sup>® </sup>patches (Group I) or standard compression with surgical swabs (Group II).</p> <p>We evaluated time to haemostasis, blood loss during the operation, blood loss after cross-clamp removal, duration of operation, drain volume, requirement for blood transfusion and surgeons rating of efficacy.</p> <p>Results</p> <p>Twenty patients were randomized (10 patients in each treatment Group). The mean time to haemostasis was 264 ± 127.1 s (range: 180-600 s) in Group I and 408 ± 159.5 s (range: 120-720 s) in Group II (p = 0.026); mean blood loss during the operation was 503.5 ± 20.7 cc (range: 474-545 cc) in Group I and 615.7 ± 60.3 cc (range: 530-720 cc) in Group II (p < 0.001); mean blood loss after cross-clamp removal was 26.5 ± 4 g (range: 22-34 g) in Group I and 45.4 ± 4.6 (range: 38-52 g) in Group II (p < 0.001) and mean drain volume was 116.7 ± 41.4 cc (range: 79-230 cc) in Group I and 134.5 ± 42.8 cc (range: 101-250 cc) in Group II (p = 0.034). There were no serious adverse events associated with use of TachoSil<sup>® </sup>patches.</p> <p>Conclusion</p> <p>For patients undergoing aortic reconstruction with Dacron grafts, TachoSil<sup>® </sup>patches were found to be safe and effective for the control of suture-hole bleeding.</p
Heterogeneous length of stay of hosts’ movements and spatial epidemic spread
Infectious diseases outbreaks are often characterized by a spatial component induced by hosts’ distribution, mobility, and interactions. Spatial models that incorporate hosts’ movements are being used to describe these processes, to investigate the conditions for propagation, and to predict the spatial spread. Several assumptions are being considered to model hosts’ movements, ranging from permanent movements to daily commuting, where the time spent at destination is either infinite or assumes a homogeneous fixed value, respectively. Prompted by empirical evidence, here we introduce a general metapopulation approach to model the disease dynamics in a spatially structured population where the mobility process is characterized by a heterogeneous length of stay. We show that large fluctuations of the length of stay, as observed in reality, can have a significant impact on the threshold conditions for the global epidemic invasion, thus altering model predictions based on simple assumptions, and displaying important public health implications
A single-center experience on below-the-knee endovascular treatment in diabetic patients
Diabetic ulceration of the foot is a major global
medical, social and economic problem and is the most
frequent end-point of diabetic complications. A
retrospective analysis from February 2017 to May
2019 of diabetic patients presenting below-the-knee
artery disease (PAD) was carried out. Only patients
treated with endovascular techniques as first choice
treatment were evaluated. Outcome measured was
perioperative mortality and morbidity. Freedom from
occlusion, secondary patency and amputation rate
were all registered. Additional maneuvers including
stenting or angioplasty with drug eluting balloon
(DEB) were reported. A total of 167 (101 male/66
female) patients with a mean age of 71 years were
included in the study. A Rutherford 3, 4, 5 and 6
categories were reported in 5, 7, 110 and 45 patients,
respectively. No perioperative mortality was reported.
Morbidity occurred in 4 (4.4%) cases and consisted of
pseudoaneurysm. Additional stenting during first
procedure was required in 7 (4%) patients, drug
eluting balloon was needed in 56 (33%) patients. At
1-year follow-up, estimated freedom from occlusion
and secondary patency was 70% and 80%
respectively. Major amputation rate was 2.4%, minor
amputation rate was 41.9%. In our experience,
extreme revascularization in search of distal direct
flow reduce the rate of amputations with an increase
in ulcer healing. New materials and techniques such
as drug eluting technology, used properly, can
improve outcome
Temporal networks of face-to-face human interactions
The ever increasing adoption of mobile technologies and ubiquitous services
allows to sense human behavior at unprecedented levels of details and scale.
Wearable sensors are opening up a new window on human mobility and proximity at
the finest resolution of face-to-face proximity. As a consequence, empirical
data describing social and behavioral networks are acquiring a longitudinal
dimension that brings forth new challenges for analysis and modeling. Here we
review recent work on the representation and analysis of temporal networks of
face-to-face human proximity, based on large-scale datasets collected in the
context of the SocioPatterns collaboration. We show that the raw behavioral
data can be studied at various levels of coarse-graining, which turn out to be
complementary to one another, with each level exposing different features of
the underlying system. We briefly review a generative model of temporal contact
networks that reproduces some statistical observables. Then, we shift our focus
from surface statistical features to dynamical processes on empirical temporal
networks. We discuss how simple dynamical processes can be used as probes to
expose important features of the interaction patterns, such as burstiness and
causal constraints. We show that simulating dynamical processes on empirical
temporal networks can unveil differences between datasets that would otherwise
look statistically similar. Moreover, we argue that, due to the temporal
heterogeneity of human dynamics, in order to investigate the temporal
properties of spreading processes it may be necessary to abandon the notion of
wall-clock time in favour of an intrinsic notion of time for each individual
node, defined in terms of its activity level. We conclude highlighting several
open research questions raised by the nature of the data at hand.Comment: Chapter of the book "Temporal Networks", Springer, 2013. Series:
Understanding Complex Systems. Holme, Petter; Saram\"aki, Jari (Eds.
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