84 research outputs found

    Endovascular therapy of arteriovenous malformation in a male patient with severe post-coital pelvic pain

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    Purpose: Congenital pelvic arteriovenous malformations (AVMs) are high-flow vascular lesions consisting of abnormal shunts between arteries and veins within a nidus. The rare presentation and extensive network of vasculature contributes to the difficulty in effective treatment. Optimal therapeutic options are determined based on the clinical presentation, the location of the lesion, and possible complications. Case report: A 24-year-old male patient with a history of recurrent pain following sexual intercourse presented with complaints of intense pelvic pain radiating to the perineal area. Computed tomography angiography (CTA) revealed a large venous aneurysm as an outflow vein of a right-sided pelvic AVM. Embolisation of the outflow veins was established along with direct percutaneous delivery of fibre coils and thrombin to the venous aneurysm of the AVM. With recurring symptoms and AVM recanalisation on angiography, another direct puncture and placement of pushable coils was made. Total AVM occlusion was achieved with no recanalisation on follow-up digital subtraction angiography (DSA), and the patient remained asymptomatic. Conclusions: Endovascular embolisation of the nidus area may result in a complete occlusion of an AVM. Therefore, a thorough understanding of the vascular anatomy of the AVM is essential in choosing an effective embolisation strategy and to minimise the risk of possible complications

    Central venous access ports in the interventional radiology suite : one-centre experience

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    Purpose: Central venous access ports (CVAP) are widely used to provide long-term vascular access for the delivery of chemotherapeutic medications. The aim of this study was to evaluate the clinical outcomes and complications following CVAP implantation in the interventional radiology suite. Material and methods: A retrospective analysis was conducted on 937 oncology patients who underwent CVAP implantation between January 2009 and June 2017. Information regarding patient characteristics, operative data, and procedural outcomes was collected and analysed. Results: A total of 937 patients scheduled for CVAP were included in the final analysis. Initial success was achieved in 930 patients (99.3%), and overall completion was achieved in 933 patients (99.6%). There were 63 complications overall. Among these, 19 (2.0%) occurred during the intra- and perioperative period and 44 were late complications (4.7%). No CVAP-related mortalities were observed. Conclusions: The analysis in the present study revealed that the CVAP is a safe and effective route for long-term administration of chemotherapy with an overall complication rate of 6.7% throughout the entire device duration. The CVAP implantation procedure carried out in the interventional radiology suite provides an advantage in the management of procedural, vascular and catheter-related complications

    Normalization and variant assessment methods in selection of road alignment variants – case study

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     The choice of the most beneficial road alignment variant is a multicriteria issue, based on transport, economic, social and environmental criteria. The criteria chosen for a multicriteria analysis can be expressed through measurable or immeasurable parameters. In order to compare and assess the variants it is necessary to normalize the criteria, which means a rescaling of their value, so that the criteria values fall into a specific range. The main aim of normalization is to assign an identical weight to each criterion in relation to other criteria. This article presents a review of the influence of criteria normalization methods and the variant assessment methods on the choice of the most beneficial road alignment variant on the example of the bypass of the town of Księżyno, which is a stretch of Regional Road 678 near Bialystok. Four variants of road alignment were compared and their ranking was created using six assessment methods. It was proven that the choices of the criteria normalization method as well as the variant assessment method both have signifi­cant influence on the result of the multicriteria analysis in the decision-making process of selecting the road alignment

    Active Brownian Particles. From Individual to Collective Stochastic Dynamics

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    We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a particular emphasis on nonlinear and stochastic dynamics of such self-propelled entities in the framework of statistical mechanics. Examples of such active units in complex physico-chemical and biological systems are chemically powered nano-rods, localized patterns in reaction-diffusion system, motile cells or macroscopic animals. Based on the description of individual motion of point-like active particles by stochastic differential equations, we discuss different velocity-dependent friction functions, the impact of various types of fluctuations and calculate characteristic observables such as stationary velocity distributions or diffusion coefficients. Finally, we consider not only the free and confined individual active dynamics but also different types of interaction between active particles. The resulting collective dynamical behavior of large assemblies and aggregates of active units is discussed and an overview over some recent results on spatiotemporal pattern formation in such systems is given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte

    Retrospective analysis of breast cancer prognosis among young and older women in a Brazilian cohort of 738 patients, 1985-2002

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    Invasive breast cancer (BC) is infrequent among women aged.5.40 years, however, the disease outlook in these younger patients is generally worse than among older women. The present study aimed to compare socio-demographic, clinical and pathological characteristics, and their association with long-term survival, between two random cohorts of young (<= 40 years) and older (50-69 years) Brazilian patients with BC. The cohort comprised of 738 randomly selected women who were diagnosed with BC at Barretos Cancer Hospital, Pio XII Foundation (Barretos, Brazil) between January 1985 and December 2002; the patients included young women (n=376) and older women (n=362). The current analysis suggested that BC in young women is associated with numerous pathological features of aggressiveness. Second cancer and bilateral BC were independent predictors of a poor outcome in the younger group. Furthermore, C-erB-2 was positively correlated with poor outcome in the older group, whereas estrogen receptor status and TNM stage were associated with disease prognosis in both groups. The overall survival rates of the two age groups were similar except when analyzed according the treatment period (1997-2002). Although patients aged <= 40 years harbored tumors with more aggressive clinicopathological characteristics, these characteristics were not independent predictors of overall survival. The present study indicates that medical advances associated with prevention of breast cancer may improve screening programs, which may therefore increase early diagnosis and subsequently lower mortality rates.The authors thank the Public Ministry of Labor (Research, Prevention and Education of Occupational Cancer) in Campinas, Brazil, and the Lions Club of Brazil for partial financial support of the present study and Dr. Vinicius de Lima Vazquez (Department of Skin cancer and Melanoma, Barretos Cancer Hospital, Pio XII Foundation, Barretos, Brazil) for assistance with the statistical analysis. The abstract was previously published in The Breast 23 (Suppl): S11, 2014.info:eu-repo/semantics/publishedVersio

    Motor Cognition and Neuroscience in Sport Psychology

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    Advances in technology have allowed research in cognitive neuroscience to contribute significantly to the discipline of sport psychology. In most cases, the research has become more rigorous and has directed current thinking on the mechanisms subserving a number of psychological theories and models of practice. Currently, the three most common neuroscience techniques informing sport and exercise research are electroencephalography, transcranial magnetic stimulation and functional magnetic resonance imaging. In this review, we consider the recent contribution of each with a focus on the development of expertise, motor cognition, motor imagery and action observation

    Cancer recurrence times from a branching process model

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    As cancer advances, cells often spread from the primary tumor to other parts of the body and form metastases. This is the main cause of cancer related mortality. Here we investigate a conceptually simple model of metastasis formation where metastatic lesions are initiated at a rate which depends on the size of the primary tumor. The evolution of each metastasis is described as an independent branching process. We assume that the primary tumor is resected at a given size and study the earliest time at which any metastasis reaches a minimal detectable size. The parameters of our model are estimated independently for breast, colorectal, headneck, lung and prostate cancers. We use these estimates to compare predictions from our model with values reported in clinical literature. For some cancer types, we find a remarkably wide range of resection sizes such that metastases are very likely to be present, but none of them are detectable. Our model predicts that only very early resections can prevent recurrence, and that small delays in the time of surgery can significantly increase the recurrence probability.Comment: 26 pages, 9 figures, 4 table

    The representation of motor (inter)action, states of action, and learning: Three perspectives on motor learning by way of imagery and execution

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    Frank C, Schack T. The representation of motor (inter)action, states of action, and learning: Three perspectives on motor learning by way of imagery and execution. Frontiers in Psychology. 2017;8: 678.Learning in intelligent systems is a result of direct and indirect interaction with the environment. While humans can learn by way of different states of (inter)action such as the execution or the imagery of an action, their unique potential to induce brain- and mind-related changes in the motor action system is still being debated. The systematic repetition of different states of action (e.g., physical and/or mental practice) and their contribution to the learning of complex motor actions has traditionally been approached by way of performance improvements. More recently, approaches highlighting the role of action representation in the learning of complex motor actions have evolved and may provide additional insight into the learning process. In the present perspective paper, we build on brain-related findings and sketch recent research on learning by way of imagery and execution from a hierarchical, perceptual-cognitive approach to motor control and learning. These findings provide insights into the learning of intelligent systems from a perceptual-cognitive, representation-based perspective and as such add to our current understanding of action representation in memory and its changes with practice. Future research should build bridges between approaches in order to more thoroughly understand functional changes throughout the learning process and to facilitate motor learning, which may have particular importance for cognitive systems research in robotics, rehabilitation, and sports
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