980 research outputs found

    High-Performance Light Field Reconstruction with Channel-wise and SAI-wise Attention

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    © Springer Nature Switzerland AG 2019. Light field (LF) images provide rich information and are suitable for high-level computer vision applications. To acquire capabilities of modeling the correlated information of LF, most of the previous methods have to stack several convolutional layers to improve the feature representation and result in heavy computation and large model sizes. In this paper, we propose channel-wise and SAI-wise attention modules to enhance the feature representation at a low cost. The channel-wise attention module helps to focus on important channels while the SAI-wise attention module guides the network to pay more attention to informative SAIs. The experimental results demonstrate that the baseline network can achieve better performance with the aid of the attention modules

    Validity and reliability analysis of the Chinese cancer pain assessment tool

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    2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Discovering universal statistical laws of complex networks

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    Different network models have been suggested for the topology underlying complex interactions in natural systems. These models are aimed at replicating specific statistical features encountered in real-world networks. However, it is rarely considered to which degree the results obtained for one particular network class can be extrapolated to real-world networks. We address this issue by comparing different classical and more recently developed network models with respect to their generalisation power, which we identify with large structural variability and absence of constraints imposed by the construction scheme. After having identified the most variable networks, we address the issue of which constraints are common to all network classes and are thus suitable candidates for being generic statistical laws of complex networks. In fact, we find that generic, not model-related dependencies between different network characteristics do exist. This allows, for instance, to infer global features from local ones using regression models trained on networks with high generalisation power. Our results confirm and extend previous findings regarding the synchronisation properties of neural networks. Our method seems especially relevant for large networks, which are difficult to map completely, like the neural networks in the brain. The structure of such large networks cannot be fully sampled with the present technology. Our approach provides a method to estimate global properties of under-sampled networks with good approximation. Finally, we demonstrate on three different data sets (C. elegans' neuronal network, R. prowazekii's metabolic network, and a network of synonyms extracted from Roget's Thesaurus) that real-world networks have statistical relations compatible with those obtained using regression models

    Role of cardiac mitofusins in cardiac conduction following simulated ischemia–reperfusion

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    Mitochondrial dysfunction induced by acute cardiac ischemia–reperfusion (IR), may increase susceptibility to arrhythmias by perturbing energetics, oxidative stress production and calcium homeostasis. Although changes in mitochondrial morphology are known to impact on mitochondrial function, their role in cardiac arrhythmogenesis is not known. To assess action potential duration (APD) in cardiomyocytes from the Mitofusins-1/2 (Mfn1/Mfn2)-double-knockout (Mfn-DKO) compared to wild-type (WT) mice, optical-electrophysiology was conducted. To measure conduction velocity (CV) in atrial and ventricular tissue from the Mfn-DKO and WT mice, at both baseline and following simulated acute IR, multi-electrode array (MEA) was employed. Intracellular localization of connexin-43 (Cx43) at baseline was evaluated by immunohistochemistry, while Cx-43 phosphorylation was assessed by Western-blotting. Mfn-DKO cardiomyocytes demonstrated an increased APD. At baseline, CV was significantly lower in the left ventricle of the Mfn-DKO mice. CV decreased with simulated-ischemia and returned to baseline levels during simulated-reperfusion in WT but not in atria of Mfn-DKO mice. Mfn-DKO hearts displayed increased Cx43 lateralization, although phosphorylation of Cx43 at Ser-368 did not differ. In summary, Mfn-DKO mice have increased APD and reduced CV at baseline and impaired alterations in CV following cardiac IR. These findings were associated with increased Cx43 lateralization, suggesting that the mitofusins may impact on post-MI cardiac-arrhythmogenesis

    The impact of sodium-glucose co-transporter-2 inhibitors on dementia and cardiovascular events in diabetic patients with atrial fibrillation

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    Aims: The effectiveness of sodium-glucose co-transporter-2 inhibitors (SGLT2i) on incident dementia in patients with diabetes and atrial fibrillation (AF) remains unknown. This study aimed to investigate the association between SGLT2i and the risk of incident dementia in diabetic patients with AF, and to explore the interactions with oral anticoagulants or dipeptidyl peptidase-4 inhibitors (DPP4i). Materials and Methods: We conducted a cohort study using Taiwan's National Health Insurance Research Database. Patients with diabetes and AFwithout a prior history of established cardiovascular diseases, were identified. Using propensity score matching, 810 patients receiving SGLT2i were matched with 1620 patients not receiving SGLT2i. The primary outcome was incident dementia, and secondary outcomes included composite cardiovascular events and mortality. Results: After up to 5 years of follow-up, SGLT2i use was associated with a significantly lower risk of incident dementia (hazard: 0.71, 95% confidence interval: 0.51–0.98), particularly vascular dementia (HR: 0.44, 95% CI: 0.24–0.82). SGLT2i was related to reduced risks of AF-related hospitalisation (HR: 0.72, 95% CI: 0.56–0.93), stroke (HR: 0.75, 95% CI: 0.60–0.94), and all-cause death (HR: 0.33, 95% CI: 0.24–0.44). The protective effects were consistent irrespective of the concurrent use of non-vitamin K antagonist oral anticoagulants (NOACs) or DPP4i. Conclusions: In diabetic patients with AF, SGLT2i was associated with reduced risks of incident dementia, AF-related hospitalisation, stroke, and all-cause death. The protective effects were independent of either concurrent use of NOACs or DPP4i

    Hierarchy measure for complex networks

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    Nature, technology and society are full of complexity arising from the intricate web of the interactions among the units of the related systems (e.g., proteins, computers, people). Consequently, one of the most successful recent approaches to capturing the fundamental features of the structure and dynamics of complex systems has been the investigation of the networks associated with the above units (nodes) together with their relations (edges). Most complex systems have an inherently hierarchical organization and, correspondingly, the networks behind them also exhibit hierarchical features. Indeed, several papers have been devoted to describing this essential aspect of networks, however, without resulting in a widely accepted, converging concept concerning the quantitative characterization of the level of their hierarchy. Here we develop an approach and propose a quantity (measure) which is simple enough to be widely applicable, reveals a number of universal features of the organization of real-world networks and, as we demonstrate, is capable of capturing the essential features of the structure and the degree of hierarchy in a complex network. The measure we introduce is based on a generalization of the m-reach centrality, which we first extend to directed/partially directed graphs. Then, we define the global reaching centrality (GRC), which is the difference between the maximum and the average value of the generalized reach centralities over the network. We investigate the behavior of the GRC considering both a synthetic model with an adjustable level of hierarchy and real networks. Results for real networks show that our hierarchy measure is related to the controllability of the given system. We also propose a visualization procedure for large complex networks that can be used to obtain an overall qualitative picture about the nature of their hierarchical structure.Comment: 29 pages, 9 figures, 4 table

    PDADMAC/Alginate-Coated Gold Nanorod For Eradication of Staphylococcus Aureus Biofilms

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    Malarmugila Manimaran,1,* Yin Yin Teo,2 James Chen Yong Kah,3 Adilet Beishenaliev,1 Yean Leng Loke,2 Yiing Yee Foo,1 Shiow-Fern Ng,4 Chin Fei Chee,5 Sek Peng Chin,6 Farid Nazer Faruqu,1 Chia-Yu Chang,7 Misni Misran,2 Lip Yong Chung,6 Bey Fen Leo,8,* Shih-Hwa Chiou,9,10 Chia-Ching Chang,7,11– 13 Sun Tee Tay,14 Lik Voon Kiew1,7 1Department of Pharmacology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia; 2Department of Chemistry, Faculty of Science, Universiti Malaya, Kuala Lumpur, Malaysia; 3Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, Singapore, Singapore; 4Centre for Drug Delivery Technology and Vaccine, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia; 5Nanotechnology Catalysis Research Centre, Universiti Malaya, Kuala Lumpur, Malaysia; 6Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Universiti Malaya, Kuala Lumpur, Malaysia; 7Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, Republic of China; 8Department of Molecular Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia; 9Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China; 10Institute of Pharmacology, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China; 11Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, Republic of China; 12Center for Intelligent Drug Systems and Smart Bio-devices, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, Republic of China; 13Institute of Physics, Academia Sinica, Nankang, Taipei, Taiwan, Republic of China; 14Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia*These authors contributed equally to this workCorrespondence: Chia-Ching Chang; Lik Voon Kiew, Email [email protected]; [email protected]: Over 75% of clinical microbiological infections are caused by bacterial biofilms that grow on wounds or implantable medical devices. This work describes the development of a new poly(diallyldimethylammonium chloride) (PDADMAC)/alginate-coated gold nanorod (GNR/Alg/PDADMAC) that effectively disintegrates the biofilms of Staphylococcus aureus (S. aureus), a prominent pathogen responsible for hospital-acquired infections.Methods: GNR was synthesised via seed-mediated growth method, and the resulting nanoparticles were coated first with Alg and then PDADMAC. FTIR, zeta potential, transmission electron microscopy, and UV–Vis spectrophotometry analysis were performed to characterise the nanoparticles. The efficacy and speed of the non-coated GNR and GNR/Alg/PDADMAC in disintegrating S. aureus-preformed biofilms, as well as their in vitro biocompatibility (L929 murine fibroblast) were then studied.Results: The synthesised GNR/Alg/PDADMAC (mean length: 55.71 ± 1.15 nm, mean width: 23.70 ± 1.13 nm, aspect ratio: 2.35) was biocompatible and potent in eradicating preformed biofilms of methicillin-resistant (MRSA) and methicillin-susceptible S. aureus (MSSA) when compared to triclosan, an antiseptic used for disinfecting S. aureus colonisation on abiotic surfaces in the hospital. The minimum biofilm eradication concentrations of GNR/Alg/PDADMAC (MBEC50 for MRSA biofilm = 0.029 nM; MBEC50 for MSSA biofilm = 0.032 nM) were significantly lower than those of triclosan (MBEC50 for MRSA biofilm = 10,784 nM; MBEC50 for MRSA biofilm 5967 nM). Moreover, GNR/Alg/PDADMAC was effective in eradicating 50% of MRSA and MSSA biofilms within 17 min when used at a low concentration (0.15 nM), similar to triclosan at a much higher concentration (50 μM). Disintegration of MRSA and MSSA biofilms was confirmed by field emission scanning electron microscopy and confocal laser scanning microscopy.Conclusion: These findings support the potential application of GNR/Alg/PDADMAC as an alternative agent to conventional antiseptics and antibiotics for the eradication of medically important MRSA and MSSA biofilms.Keywords: biofilm, gold nanorod, S. aureus, PDADMAC, MRSA, MSS

    Macrophage-derived human resistin is induced in multiple helminth infections and promotes inflammatory monocytes and increased parasite burden.

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    Parasitic helminth infections can be associated with lifelong morbidity such as immune-mediated organ failure. A better understanding of the host immune response to helminths could provide new avenues to promote parasite clearance and/or alleviate infection-associated morbidity. Murine resistin-like molecules (RELM) exhibit pleiotropic functions following helminth infection including modulating the host immune response; however, the relevance of human RELM proteins in helminth infection is unknown. To examine the function of human resistin (hResistin), we utilized transgenic mice expressing the human resistin gene (hRetnTg+). Following infection with the helminth Nippostrongylus brasiliensis (Nb), hResistin expression was significantly upregulated in infected tissue. Compared to control hRetnTg- mice, hRetnTg+ mice suffered from exacerbated Nb-induced inflammation characterized by weight loss and increased infiltration of inflammatory monocytes in the lung, along with elevated Nb egg burdens and delayed parasite expulsion. Genome-wide transcriptional profiling of the infected tissue revealed that hResistin promoted expression of proinflammatory cytokines and genes downstream of toll-like receptor signaling. Moreover, hResistin preferentially bound lung monocytes, and exogenous treatment of mice with recombinant hResistin promoted monocyte recruitment and proinflammatory cytokine expression. In human studies, increased serum resistin was associated with higher parasite load in individuals infected with soil-transmitted helminths or filarial nematode Wuchereria bancrofti, and was positively correlated with proinflammatory cytokines. Together, these studies identify human resistin as a detrimental factor induced by multiple helminth infections, where it promotes proinflammatory cytokines and impedes parasite clearance. Targeting the resistin/proinflammatory cytokine immune axis may provide new diagnostic or treatment strategies for helminth infection and associated immune-mediated pathology

    Identification of an INa-dependent and Ito-mediated proarrhythmic mechanism in cardiomyocytes derived from pluripotent stem cells of a Brugada syndrome patient

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    Brugada syndrome (BrS) is an inherited cardiac arrhythmia commonly associated with SCN5A mutations, yet its ionic mechanisms remain unclear due to a lack of cellular models. Here, we used human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from a BrS patient (BrS1) to evaluate the roles of Na+ currents (INa) and transient outward K+ currents (Ito) in BrS induced action potential (AP) changes. To understand the role of these current changes in repolarization we employed dynamic clamp to "electronically express" IK1 and restore normal resting membrane potentials and allow normal recovery of the inactivating currents, INa, ICa and Ito. HiPSC-CMs were generated from BrS1 with a compound SCN5A mutation (p. A226V & p. R1629X) and a healthy sibling control (CON1). Genome edited hiPSC-CMs (BrS2) with a milder p. T1620M mutation and a commercial control (CON2) were also studied. CON1, CON2 and BrS2, had unaltered peak INa amplitudes, and normal APs whereas BrS1, with over 75% loss of INa, displayed a loss-of-INa basal AP morphology (at 1.0 Hz) manifested by a reduced maximum upstroke velocity (by ~80%, p < 0.001) and AP amplitude (p < 0.001), and an increased phase-1 repolarization pro-arrhythmic AP morphology (at 0.1 Hz) in ~25% of cells characterized by marked APD shortening (~65% shortening, p < 0.001). Moreover, Ito densities of BrS1 and CON1 were comparable and increased from 1.0 Hz to 0.1 Hz by ~ 100%. These data indicate that a repolarization deficit could be a mechanism underlying BrS
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