A General FOFE-net Framework for Simple and Effective Question Answering over Knowledge Bases

Question answering over knowledge base (KB-QA) has recently become a popular research topic in NLP. One of the popular ways to solve the KBQA problem is to make use of a pipeline of several NLP modules, including entity discovery and linking (EDL) and relation detection. Recent success on KBQA task usually involves complex network structures with sophisticated heuristics. Inspired by a previous work that builds a strong KBQA baseline, we propose a simple but general neural model composed of fixed-size ordinally forgetting encoding (FOFE) and deep neural networks, called FOFE-net to solve KB-QA problem at different stages. For evaluation, we use two popular KB-QA datasets, SimpleQuestions, WebQSP, and our newly created dataset, FreebaseQA. The experimental results show that FOFE-net performs well on KBQA subtasks, entity discovery and linking (EDL) and relation detection, and in turn pushing overall KB-QA system to achieve strong results on all the datasets

Study on the technology and properties of 3D bioprinting SF/GT/n-HA composite scaffolds

In this paper, three kinds of natural polymer materials, silk fibroin (SF), gelatin (GT), and nano-hydroxyapatite (n-HA), are mixed as 3D printing bioink to mimic protein polysaccharide and collagen fibers in natural articular cartilage. By changing the SF content, SF/GT/n-HA composite scaffolds with different ratios are prepared using 3D bioprinting technology. The microstructure and morphology, biological properties and mechanical properties of composite scaffolds are characterized. The results show that the printing precision of the bioink with 10% SF is best, and the composite scaffold with 10% SF also exhibits better mechanical properties, whose tensile elastic modulus is 10.60 ± 0.32 MPa and the compression elastic modulus is 1.22 ± 0.06 MPa. These studies are helpful to understand the interaction between SF, GT and n-HA, and provide a theoretical basis for the preparation of better silk fibroin-based composite scaffolds

Preparation of PVA-GO Composite Hydrogel and Effect of Ionic Coordination on Its Properties

This paper adopts a method combining hybrid self-assembly, cyclic freezing-thawing and annealing treatment to prepare polyvinyl alcohol (PVA) and graphene oxide (GO) composite hydrogel. Then, the PVA-GO composite hydrogels are re-swelled in different ionic solutions (NaCl, MgCl2, CaCl2 and AlCl3) to improve mechanical strength, toughness and wear resistance by the ionic coordination bonds. The microstructure and morphology are characterized by Fourier transforms infrared spectroscopy (FTIR), x-ray diffraction (XRD) and Scanning electron microscopy (SEM), finding that the internal structure is porous three-dimensional network. Mechanical experiments indicate that the composite hydrogel with GO content of 0.05 wt% immersed in MgCl2 solution displays the best mechanical properties overall. Its tensile strength can reach 11.10 MPa and the elastic modulus reaches 1.72 MPa, which is 175% and 85% higher than the pure PVA, respectively. Sliding friction experiments illustrate that the composite hydrogel immersed in AlCl3 solution exhibits the lowest friction coefficient, and the higher the valence state of metal cation is, the better the wear reduction effect is. We expect to enrich the development of PVA-GO hydrogels in tissue engineering through synergy of hydrogen bonds and ionic coordination bonds

Research progress in degradable hydrogels as articular cartilage repair materials

Degradable hydrogels are widely used in the repair and regeneration of articular cartilage because of their good biocompatibility and biodegradability. Three application strategies of degradable hydrogels in cartilage tissue engineering were focused in this review. Firstly, the proteoglycan materials and nanocomposite materials for in-situ formed injectable hydrogels were reviewed. Secondly, the advantages and disadvantages of traditional technology for tissue engineering scaffolds and the preparation methods of combination of various technologies were systematically summarized. Importantly, the research progress of 3D printed tissue engineering scaffolds from pure cartilage to bone/cartilage integration, from single layer to multi-layer in recent years were summarized. Finally, the limitations of degradable hydrogel as articular cartilage scaffold material in micro-directional structure and bioactivity functionalization were discussed.It was prospected that developing highly biomimetic gradient scaffolds with multi-material, multi-scale and multi-inducement will be an important research direction of articular cartilage tissue engineering in the future