1,268 research outputs found

    Determining the Mechanical Properties of Microcrystalline Cellulose (MCC)-Filled PET-PTT Blend Composites

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    Polymer composite materials consisting of poly(ethylene terephthalate) (PET)-poly(trimethylene terephthalate) (PTT) blends and microcrystalline cellulose (MCC) were prepared by injection molding. The composites were analyzed for tensile, flexural, and impact strength as well as density determinations. There was no statistical difference in terms of mechanical properties between the control PET-PTT blend and 2.5 wt% MCC-filled composites. Because of better compatibility as well as better stress-transfer properties, the tensile strength of the composites was larger (reaching values from 24.8-36.3 MPa with the addition of 20 wt% MCC). Elongation at break of the composites was greater (reaching values from 2.3-3.3% with the addition of 20 wt% MCC). The tensile modulus of MCC-filled composites systemically increased with increasing MCC loading (reaching values from 1.11-1.68 GPa with the addition of 30 wt% MCC). The flexural modulus of composites was higher than the control PET-PTT blend. The modulus also increased with increasing MCC loading (reaching values from 2.10-3.37 GPa with the addition of 30 wt% MCC). The Izod impact strength of the composites decreased as the MCC loading increased and this observation was in good agreement with commonly observed filled polymer systems

    GCN-RL Circuit Designer: Transferable Transistor Sizing with Graph Neural Networks and Reinforcement Learning

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    Automatic transistor sizing is a challenging problem in circuit design due to the large design space, complex performance trade-offs, and fast technological advancements. Although there has been plenty of work on transistor sizing targeting on one circuit, limited research has been done on transferring the knowledge from one circuit to another to reduce the re-design overhead. In this paper, we present GCN-RL Circuit Designer, leveraging reinforcement learning (RL) to transfer the knowledge between different technology nodes and topologies. Moreover, inspired by the simple fact that circuit is a graph, we learn on the circuit topology representation with graph convolutional neural networks (GCN). The GCN-RL agent extracts features of the topology graph whose vertices are transistors, edges are wires. Our learning-based optimization consistently achieves the highest Figures of Merit (FoM) on four different circuits compared with conventional black-box optimization methods (Bayesian Optimization, Evolutionary Algorithms), random search, and human expert designs. Experiments on transfer learning between five technology nodes and two circuit topologies demonstrate that RL with transfer learning can achieve much higher FoMs than methods without knowledge transfer. Our transferable optimization method makes transistor sizing and design porting more effective and efficient.Comment: Accepted to the 57th Design Automation Conference (DAC 2020); 6 pages, 8 figure

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    Prediction of Advanced Fibrosis in Nonalcoholic Fatty Liver Disease: An Enhanced Model of BARD Score.

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    UNLABELLED: BACKGROUNDAIMS: The BARD score is a model to detect advanced liver fibrosis in nonalcoholic fatty liver disease (NAFLD) patients. The aims of this study were to identify additional factors and then to build an enhanced version of the BARD score. METHODS: One hundred seven patients with biopsy-proven NAFLD were enrolled retrospectively. Logistic regressions were performed to identify independent risk factors for advanced liver fibrosis (stage 3 or 4). An enhanced model of the BARD score (BARDI score) was built and evaluated with a receiver operating characteristic (ROC) curve. RESULTS: In multivariate analysis, age (odds ratio [OR], 0.89; p=0.04), aspartate aminotransferase/alanine aminotransferase ratio (OR, 1.73; p CONCLUSIONS: The BARDI score had an improved PPV over the BARD score and maintained an excellent NPV. Further study is warranted for its external validation and comparison with other models

    Heterologous gene expression using self-assembled supra-molecules with high affinity for HSP70 chaperone

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    Contrary to the results of direct expression, various human proteins (ferritin light-chain, epithermal growth factor, interleukin-2, prepro-ghrelin, deletion mutants of glutamate decarboxylase and arginine deiminase, and mini-proinsulin) were all soluble in Escherichia coli cytoplasm when expressed with the N-terminus fusion of ferritin heavy-chain (FTN-H). Through systematic investigations, we have found that a specific peptide motif within FTN-H has a high affinity to HSP70 chaperone DnaK, and that the peptide motif was composed of a hydrophobic core of three residues (Ile, Phe and Leu) and two flanking regions enriched with polar residues (Gly, Gln and Arg). It was also observed that all the recombinant proteins expressed with the fusion of FTN-H formed spherical nanoparticles with diameters of 10–15 nm, as confirmed by the transmission electron microscopy image. The protein nanoparticles are non-covalently cross-linked supra-molecules formed by the self-assembly function of FTN-H. Upon the formation of the supra-molecule, its size is likely to be limited by the assembly properties of FTN-H, thereby keeping the self-assembled particles soluble. This study reports on the dual function of FTN-H for fusion expression and solubility enhancement of heterologous proteins: (i) high-affinity interaction with DnaK and (ii) formation of self-assembled supra-molecules with limited and constant sizes, thereby avoiding the undesirable formation of insoluble macro-aggregates of heterologous proteins

    Postoperative occlusion of visual axis with fibrous membrane in the presence of anterior capsular phimosis in a patient with pseudoexfoliation syndrome: a case report

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    This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Abstract Background To report a case of postoperative fibrous membrane formation occluding the visual axis in the presence of anterior capsular phimosis in a patient with pseudoexfoliation syndrome. Case presentation A 79-year-old Asian woman with pseudoexfoliation syndrome underwent uneventful phacoemulsification and implantation of one-piece hydrophilic acrylic square-edged intraocular lens (Cristalens) in the right eye. Two months later, she had blurred vision in the right eye with the best-corrected visual acuity (BCVA) of 20/40. Formation of fibrous membrane occluding the capsulorhexis opening with contraction of anterior capsule was observed, which was confirmed by anterior segment optical coherence tomography. Clear visual axis was achieved by lysis of the membrane using Nd:YAG laser. The BCVA improved to 20/20. Conclusions Occlusion of the visual axis with fibrous membrane can develop in the presence of anterior capsular phimosis in a patient with pseudoexfoliation syndrome
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