135 research outputs found

    Efficient parallel processing of all-pairs shortest paths on multicore and GPU systems

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    Finding the shortest path between any two nodes in a graph, known as the All-Pairs Shortest Paths (APSP), is a fundamental problem in many data analysis problems, such as supply chains in logistics, routing protocols in IoT networks that involve consumer electronics as well as data analysis for social networking apps and Google Maps apps used by the general public on their smartphones. In this work, we present a novel approach to solve the APSP problem on multicore and GPU systems. In our approach, a graph is first pre-processed by partitioning the graph into sub-graphs. Then, each sub-graph is processed in parallel using any existing shortest path algorithm such as the Floyd-Warshall algorithm or Dijkstra’s algorithm. Finally, the distance results in individual sub-graphs are aggregated to obtain the distances of APSP for the entire graph. OpenMP and CUDA are used to implement the parallelization on multicore CPUs and GPUs, respectively. We conduct the extensive experiments with both synthetic and real-world graphs on the JADE (Joint Academic Data Science Endeavour) cluster at the University of Oxford, which is part of the Tier-2 high performance computing facilities in the UK. In the experiments, we compared our methods with three existing APSP algorithms in the literature, including n-Dijkstra, ParAPSP and SuperFW. The results show that our methods outperform the existing algorithms, achieving the speedup of up to 8.3x over Dijkstra

    7. Long term results of quadrangular autologous pericardial patch reconstruction of the pulmonary artery during arterial switch operation on post-

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    The aim of this retrospective study is to evaluate the technique of Quadrangular Fresh Autologous Pericardial Patch for the reconstruction of the pulmonary artery in Arterial Switch Operation (ASO) to prevent the post-operative pulmonary artery stenosis (PAS). A total of 287 consecutive infants with transposition of great arteries were treated with ASO in our center between January 2000 and September 2014. The mean age was (7.76days) and mean weight was (3.67kg). The new pulmonary arterial root was reconstructed with a fresh quadrangular autologous patch. The technique includes extensive mobilization of both pulmonary artery branches and direct suturing of the parch to 2/3 of the annulus of the new pulmonary artery trunk first, and then reconstruction finish by the re-suspension of the posterior commissure of the new pulmonary valve inside the patch. Patients were examined using trans-thoracic echocardiography consecutively at discharge form the hospital, and at 3–6 months and yearly after discharge. The mean follow up time was 78 months. The early mortality was 5.19% (17 patients), and there were no late mortality. The highest mortality was reported during the beginning of the pediatric surgical program. The mortality for the last 100 patients was 1%. The pressure gradient across the pulmonary valve in 249 patients (87%, was less than 20mmHg. Mild pulmonary stenosis (pressure gradient of 20–40mmHg) was present in 32 patients (11.14%) and moderate pulmonary stenosis with gradient 40–60mmHg was manifested in 4 patients (1.39%). Reconstruction of the new Pulmonary artery during the ASO, using the quadrangular autologous fresh pericardial patch, is effective and reproducible in reducing the incidence of post-operative pulmonary stenosis

    Role of Stem Cells in Orthopaedic Surgery: Theoretical Survey

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    This study aims at analyzing the Stem cell application is a burgeoning field of medicine that is likely to influence the future of orthopaedic surgery. Stem cells are associated with great promise and great controversy. For the orthopaedic surgeon, stem cells may change the way that orthopaedic surgery is practiced and the overall approach of the treatment of musculoskeletal disease. Stem cells may change the field of orthopaedics from a field dominated by surgical replacements and reconstructions to a field of regeneration and prevention. This review will introduce the basic concepts of stem cells pertinent to the orthopaedic surgeon and proceed with a more in depth discussion of current developments in the study of stem cells in orthopaedic surgery. Keywords: Stem cell, orthopaedic, surgery

    A review of constraints and adjustable parameters in microgrids for cost and carbon dioxide emission reduction

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    In a world grappling with escalating energy demand and pressing environmental concerns, microgrids have risen as a promising solution to bolster energy efficiency, alleviate costs, and mitigate carbon emissions. This article delves into the dynamic realm of microgrids, emphasizing their indispensable role in addressing today's energy needs while navigating the hazards of pollution. Microgrid operations are intricately shaped by a web of constraints, categorized into two essential domains: those inherent to the microgrid itself and those dictated by the external environment. These constraints, stemming from component limitations, environmental factors, and grid connections, exert substantial influence over the microgrid's operational capabilities. Of particular significance is the three-tiered control framework, encompassing primary, secondary, and energy management controls. This framework guarantees the microgrid's optimal function, regulating power quality, frequency, and voltage within predefined parameters. Central to these operations is the energy management control, the third tier, which warrants in-depth exploration. This facet unveils the art of fine-tuning parameters within the microgrid's components, seamlessly connecting them with their surroundings to streamline energy flow and safeguard uninterrupted operation. In essence, this article scrutinizes the intricate interplay between microgrid constraints and energy management parameters, illuminating how the nuanced adjustment of these parameters is instrumental in achieving the dual objectives of cost reduction and Carbon Dioxide emission minimization, thereby shaping a more sustainable and eco-conscious energy landscape. This study investigates microgrid dynamics, focusing on the nuanced interplay between constraints and energy management for cost reduction and Carbon Dioxide minimization. We employ a three-tiered control framework—primary, secondary, and energy management controls—to regulate microgrid function, exploring fine-tuned parameter adjustments for optimal performance

    Aberrant right subclavian artery in a cadaver: a case report of an aortic arch anomaly

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    In early embryogenesis, aortic anomalies occur as a consequence of disorders in the development of the primitive aortic arches system. Aberrant right subclavian artery, also known as arteria lusoria, is one of the important congenital anomalies of the aortic arch, in which the right subclavian artery arises from the arch of aorta instead of the brachiocephalic trunk. During routine dissection of a female cadaver, we observed retro-oesophageal aberrant right subclavian artery arising as the fourth branch from the aortic arch. In this case, the brachiocephalic trunk was absent. Early detection of aortic arch anomalies through diagnostic interventions is helpful to avoid complications during surgical procedures

    Interaction Analysis of MRP1 with Anticancer Drugs Used in Ovarian Cancer: In Silico Approach

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    Multidrug resistance (MDR) is one of the major therapeutic challenges that limits the efficacy of chemotherapeutic response resulting in poor prognosis of ovarian cancer (OC). The multidrug resistance protein 1 (MRP1) is a membrane-bound ABC transporter involved in cross resistance to many structurally and functionally diverse classes of anticancer drugs including doxorubicin, taxane, and platinum. In this study, we utilize homology modelling and molecular docking analysis to determine the binding affinity and the potential interaction sites of MRP1 with Carboplatin, Gemcitabine, Doxorubicin, Paclitaxel, and Topotecan. We used AutoDock Vina scores to compare the binding affinities of the anticancer drugs against MRP1. Our results depicted Carboplatin \u3c Gemcitabine \u3c Topotecan \u3c Doxorubicin \u3c Paclitaxel as the order of binding affinities. Paclitaxel has shown the highest binding affinity whereas Carboplatin displayed the lowest affinity to MRP1. Interestingly, our data showed that Carboplatin, Paclitaxel, and Topotecan bind specifically to Asn510 residue in the transmembrane domains 1 of the MRP1. Our results suggest that Carboplatin could be an appropriate therapeutic choice against MRP1 in OC as it couples weakly with Carboplatin. Further, our findings also recommend opting Carboplatin with Gemcitabine as a combinatorial chemotherapeutic approach to overcome MDR phenotype associated with recurrent OC. View Full-Tex

    Computer Aided Autism Diagnosis Using Diffusion Tensor Imaging

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    © 2013 IEEE. Autism Spectrum Disorder (ASD), commonly known as autism, is a lifelong developmental disorder associated with a broad range of symptoms including difficulties in social interaction, communication skills, and restricted and repetitive behaviors. In autism spectrum disorder, numerous studies suggest abnormal development of neural networks that manifest itself as abnormalities of brain shape, functionality, and/ or connectivity. The aim of this work is to present our automated computer aided diagnostic (CAD) system for accurate identification of autism spectrum disorder based on the connectivity of the white matter (WM) tracts. To achieve this goal, two levels of analysis are provided for local and global scores using diffusion tensor imaging (DTI) data. A local analysis using the Johns Hopkins WM atlas is exploited for DTI atlas-based segmentation. Furthermore, WM integrity is examined by extracting the most notable features representing WM connectivity from DTI. Interactions of WM features between different areas in the brain, demonstrating correlations between WM areas were used, and feature selection among those associations were made. Finally, a leave-one-subject-out classifier is employed to yield a final per-subject decision. The proposed system was tested on a large dataset of 263 subjects from the National Database of Autism Research (NDAR) with their Autism Diagnostic Observation Schedule (ADOS) scores and diagnosis (139 typically developed: 66 males, and 73 females, and 124 autistics: 66 males, and 58 females), with ages ranging from 96 to 215 months, achieving an overall accuracy of 73%. In addition to this achieved global accuracy, diagnostically-important brain areas were identified, allowing for a better understanding of ASD-related brain abnormalities, which is considered as an essential step towards developing early personalized treatment plans for children with autism spectrum disorder

    Highly efficient GaN Doherty power amplifier for N78 sub-6 GHz band 5G applications

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    In this paper, a high-efficiency GaN Doherty power amplifier (DPA) for 5G applications in the N78 sub-6 GHz band is introduced. The theoretical analysis of the matching networks for the peak and carrier transistors is presented, with a focus on the impact of unequal power splitting for both transistors and the recommendation of a post-harmonic suppression network. The proposed design features an unequal Wilkinson power divider at the input and a post-harmonic suppression network at the output, both of which are crucial for achieving high efficiency. The Doherty power amplifier comprises two GaN 10 W HEMTs, measured across the 3.3 GHz to 3.8 GHz band (the N78 band), and the results reveal significant improvements in gain, output power, drain efficiency, and power-added efficiency. Specifically, the proposed design achieved a power gain of over 12 dB and 42 dBm saturated output power. It also achieved a drain efficiency of 80% at saturation and a power-added efficiency of 75.2%. Furthermore, the proposed harmonic suppression network effectively attenuated the harmonics at the output of the amplifier from the second to the fourth order to more than −50 dB, thus enhancing the device’s linearity

    Avoidable emergency department visits among palliative care cancer patients: novel insights from Saudi Arabia and the Middle East

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    Background Several studies emerging from developed countries have highlighted a significant number of potentially avoidable emergency department (ED) visits by cancer patients during the end-of-life period. However, there is a paucity of information from developing nations regarding palliative care practices and the utilization of the ED by palliative care patients. Herein, we aim to characterize ED admissions among patients receiving palliative care at our tertiary center in Saudi Arabia. Methods This is a retrospective, cross-sectional study evaluating ED visits amongst adult patients with advanced cancer who were receiving treatment under the palliative care department. This study took place over a period of 12 months from July 2021 through to July 2022. Three palliative care specialist physicians independently and blindly reviewed each patient’s ED visits and determined whether the visit was avoidable or unavoidable. Results A total of 243 patients were included in the final analysis, of which 189 (78.1%) patients had unavoidable visits and 53 (21.9%) patient visits were classified as avoidable. A significantly higher proportion of breast cancer patients presented with unavoidable admissions (14.3% vs. 3.8%, P = 0.037) compared to other cancer types. The incidence of dyspnea (23.8% vs. 5.7%, P < 0.001) and fevers/chills (23.3% vs. 5.7%, P = 0.005) was significantly higher in patients with unavoidable visits. Patients with avoidable visits had a significantly greater proportion of visits for dehydration (13.2% vs. 2.1%, P = 0.002). Notably, although hospital stay was significantly longer in the unavoidable group (P = 0.045), mortality for palliative care patients—regardless of whether their ED visit was avoidable or unavoidable—was not statistically different (P=-0.069). Conclusion To our knowledge, this is the largest and most comprehensive study from Saudi Arabia and the Middle East providing insights into the utilization of palliative care services in the region and the propensity of advanced cancer patients towards visiting the ED. Future studies ought to explore interventions to reduce the frequency of avoidable ED visits
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