585 research outputs found
Single-Center Experience with Simultaneous Mural Aortic Thrombosis and Peripheral Obstructive Disease in Pre-COVID-19 and COVID-19 Era
Background: Mural aortic thrombosis associated with chronic peripheral obstruction of the lower limbs is an unusual event. Repeated embolism of instability aortic mural thrombosis caused acute limb ischemia (Rutherford 2 classification) in patients with peripheral arterial disease (PAD). We report a single-center experience for patients with transmural aortic thrombosis and peripheral artery disease. Methods: We retrospectively analyzed data of 54 patients with aortic mural thrombus disease with PAD presentation, treated at our center between 2013 and 2022. Results: Thirty patients (six with proven SARS-CoV-2 infection) underwent hybrid or staged treatment for an aortic lesion and for lower limb ischemia, by the placement of an endovascular aortic stent graft and a femoro-distal or a popliteal-distal bypass graft. The remaining 24 cases were only subjected to an intravascular treatment of the thoracic or abdominal aorta. Transient renal failure occurred in three patients. No embolic events were detected during the procedures. Aortic-related mortality was reported in just one patient who died from multiple organ failure. There was an embolic stroke in one patient with proven SARS-CoV-2 infection, three major amputations in patients with proven SARS-CoV-2 infection and no aortic-related mortality. Conclusions: Stent coverage of complex aortic lesions, alone or in association with a distal bypass graft, supports this approach in a variety of settings. The COVID-19 pandemic caused an increased mortality and amputation rate
The TU Wien Turbulent Water Channel: Flow control loop and three-dimensional reconstruction of anisotropic particle dynamics
A horizontal water channel facility was built to study particle dynamics in a turbulent flow. The channel is sufficiently long to produce fully developed turbulence at the test section, and the width-to-height ratio is sufficiently large to avoid the sidewall effect for a large proportion of the cross-section. The system was designed to study the dynamics of complex-shaped particles in wall-bounded turbulence, the characteristics of which can be finely controlled. A maximum bulk velocity of up to 0.8 m s−1 can be achieved, corresponding to a bulk Reynolds number of up to 7 × 104 (shear Reynolds number ≈ 1580 ), and flow parameters can be controlled within ±0.1%. The transparent channel design and aluminum structures allow easy optical access, which enables multiple laser and camera arrangements. With the current optical setup, a measurement volume of up to 54 × 14 × 54 mm3 can be imaged and reconstructed with six cameras from the top, bottom, and sides of the channel. Finally, the in-house developed reconstruction and tracking procedure allows us to measure the full motion of complex objects (i.e., shape reconstruction, translational, and rotational motions), and in this instance, it is applied to the case of microscopic, non-isotropic polyamide fibers
Minimal Unitary Models and The Closed SU(2)-q Invariant Spin Chain
We consider the Hamiltonian of the closed invariant chain. We
project a particular class of statistical models belonging to the unitary
minimal series. A particular model corresponds to a particular value of the
coupling constant. The operator content is derived. This class of models has
charge-dependent boundary conditions. In simple cases (Ising, 3-state Potts)
corresponding Hamiltonians are constructed. These are non-local as the original
spin chain.Comment: 19 pages, latex, no figure
Fermionic representations for characters of M(3,t), M(4,5), M(5,6) and M(6,7) minimal models and related Rogers-Ramanujan type and dilogarithm identities
Characters and linear combinations of characters that admit a fermionic sum
representation as well as a factorized form are considered for some minimal
Virasoro models. As a consequence, various Rogers-Ramanujan type identities are
obtained. Dilogarithm identities producing corresponding effective central
charges and secondary effective central charges are derived. Several ways of
constructing more general fermionic representations are discussed.Comment: 14 pages, LaTex; minor correction
Local height probabilities in a composite Andrews-Baxter-Forrester model
We study the local height probabilities in a composite height model, derived
from the restricted solid-on-solid model introduced by Andrews, Baxter and
Forrester, and their connection with conformal field theory characters. The
obtained conformal field theories also describe the critical behavior of the
model at two different critical points. In addition, at criticality, the model
is equivalent to a one-dimensional chain of anyons, subject to competing two-
and three-body interactions. The anyonic-chain interpretation provided the
original motivation to introduce the composite height model, and by obtaining
the critical behaviour of the composite height model, the critical behaviour of
the anyonic chains is established as well. Depending on the overall sign of the
hamiltonian, this critical behaviour is described by a diagonal coset-model,
generalizing the minimal models for one sign, and by Fateev-Zamolodchikov
parafermions for the other.Comment: 34 pages, 5 figures; v2: expanded introduction, references added and
other minor change
Response of Foraminifera to Anthropogenic Nicotine Pollution of Cigarette Butts: An Experimental Approach
The most often dispersed environmental pollutants that are released both directly and indirectly into the environment that may eventually reach aquatic ecosystems and contaminate aquatic biomes are cigarette butts (CBs). Toxicants such as nicotine, dangerous metals, total particulate matter, and recognized carcinogens can be introduced and transported via CBs into aquatic ecosystems. The examination of the effects of synthetic nicotine on three different species of cultured benthic foraminifera was the focus of this study. Three foraminiferal species from three distinct biomineralization pathways were specifically examined for viability and cellular ultrastructure, including the calcareous perforate Rosalina globularis, the calcareous imperforate Quinqueloculina spp., and the agglutinated Textularia agglutinans. The survival rate, cellular stress, and decalcification were used to assess the toxicological effects of synthetic nicotine. We were able to analyze the reaction of major macromolecules and calcium carbonate to this pollutant using FTIR (Fourier Transform Infrared) spectroscopy. High Performance Liquid Chromatography (HPLC) study was performed to increase our understanding of nicotine bioavailability in the medium culture. Different acute experiments were performed at different dates, and all indicated that synthetic nicotine is acutely hazardous to all three cultured foraminiferal taxa at lethal and sublethal concentrations. Each species responded differently depending on the type of shell biomineralization. Synthetic nicotine enhances shell decalcification and affects the composition of cytoplasmic macromolecules such as lipids and proteins, according to the FTIR spectroscopy investigations. The lipid content rose at lethal concentrations, possibly due to the creation of vesicles. The proteins signal evidences general cellular dyshomeostasis. The integration among the acute toxicity assay, synchrotron, and chemical HPLC analyses provided a valuable approach for the assessment of nicotine as a biomarker of exposure to the toxicants associated with smoking and the impact of this emerging and hazardous material on calcifying marine species
Exceptional structure of the dilute A model: E and E Rogers--Ramanujan identities
The dilute A lattice model in regime 2 is in the universality class of
the Ising model in a magnetic field. Here we establish directly the existence
of an E structure in the dilute A model in this regime by expressing
the 1-dimensional configuration sums in terms of fermionic sums which
explicitly involve the E root system. In the thermodynamic limit, these
polynomial identities yield a proof of the E Rogers--Ramanujan identity
recently conjectured by Kedem {\em et al}.
The polynomial identities also apply to regime 3, which is obtained by
transforming the modular parameter by . In this case we find an
A_1\times\mbox{E}_7 structure and prove a Rogers--Ramanujan identity of
A_1\times\mbox{E}_7 type. Finally, in the critical limit, we give
some intriguing expressions for the number of -step paths on the A
Dynkin diagram with tadpoles in terms of the E Cartan matrix. All our
findings confirm the E and E structure of the dilute A model found
recently by means of the thermodynamic Bethe Ansatz.Comment: 9 pages, 1 postscript figur
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