1,720,982 research outputs found
Natural language to SQL: Where are we today?
No full textTranslating natural language to SQL (NL2SQL) has received extensive attention lately, especially with the recent success of deep learning technologies. However, despite the large number of studies, we do not have a thorough understanding of how good existing techniques really are and how much is applicable to real-world situations. A key difficulty is that different studies are based on different datasets, which often have their own limitations and assumptions that are implicitly hidden in the context or datasets. Moreover, a couple of evaluation metrics are commonly employed but they are rather simplistic and do not properly depict the accuracy of results, as will be shown in our experiments. To provide a holistic view of NL2SQL technologies and access current advancements, we perform extensive experiments under our unified framework using eleven of recent techniques over 10+ benchmarks including a new benchmark (WTQ) and TPC-H. We provide a comprehensive survey of recent NL2SQL methods, introducing a taxonomy of them. We reveal major assumptions of the methods and classify translation errors through extensive experiments. We also provide a practical tool for validation by using existing, mature database technologies such as query rewrite and database testing. We then suggest future research directions so that the translation can be used in practice.1
Extracellular matrix-based sticky sealants for scar-free corneal tissue reconstruction
No full text© 2022 The AuthorsRegenerative medicine requires both tissue restoration and ease of compliance for clinical application. Considering this, sticky tissue sealants have been shown to have great potentials over surgical suturing and wound treatment. However, tissue sealants currently used pose challenges such as uncontrollable adhesion formation, mechanical mismatch, and lack of tissue restoration. A new sticky sealant based on gelatinized cornea-derived extracellular matrix (GelCodE) with a visible light-activating system is firstly being introduced in this study. De novo tissue regeneration relies on the matrisome in charge of tissue-organization and development within GelCodE while visible light-based photopolymerization with ruthenium/sodium persulfate rapidly induces covalent bonds with the adjacent tissues. The ease of not only in vivo application, biocompatibility, and biointegration, but also exceptional de novo tissue formation is demonstrated in this study. Interestingly, newly regenerated tissues were shown to have normal tissue-like matrices with little scar formation. Hence, this work presents a promising strategy to meet clinical demands for scar-free tissue recovery with superior ease of clinical application.11Nsciescopu
3D Printed Extracellular Matrix Patches with Spatiotemporally Compartmentalized Multi-Growth Factors for Promoting Cerebral Angiogenesis
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Visible-Light Activated Tissue-Derived ECM Bioinks for Printing Biofunctional Tissue Equivalents in Centimeter-Scale
No full textIn the field of tissue engineering, decellularized extracellular matrix (dECM) has emerged as a highly biomimetic material, comprising of a complex of tissue-specific
proteins and growth factors. Recent studies have presented that tissue or organ-derived dECM can be utilized as a bioink for 3D cell printing to reproduce complex
tissue structures as well as biophysical and biochemical cues for tissue-specific function and maturation. Yet, dECM bioinks have been challenged with respect to their
printability, shape fidelity and physical properties, resulting in limited scalability. Here, we report dECM-based bioinks that can be mechanically reinforced by the
secondary crosslinking with visible-light irradiation (400–450 nm). The mechanism of crosslinking is mainly related to tyrosine radicals, generated by the visible light,
coupled with nearby radicals inherent to the dECM to rapidly produce dityrosine, of which synthesis was monitored by autofluorescence measurement. This rapid
reaction did not affect bioink viscosity profile but enhanced the compressive and complex moduli of the new bioinks by 4.3 and 10.8 times, respectively, compared
with those of original dECM bioinks. Photopolymerized dECM bioinks enabled successful fabrication of cylindrical constructs to 86% of the pre-designed height, 5.5
mm, whilst non-photocrosslinked constructs could only be fabricated to approximately 23% of original height. In addition, geometrically complex and large constructs
(e.g., the human ear and a hollow pyramid) could also be fabricated without any additional supports. Biocompatibility and tissue-specific functionality of the new
bioinks were then confirmed based on the cornea and the heart. Encapsulated keratocytes in cornea-derived dECM (Co-dECM) bioinks with crosslinker showed similar
level of functions to the cells in the original Co-dECM bioink, upregulated mRNA levels of cornea-specific genes (KERA and ALDH), and downregulated the level of
the myofibroblast marker, ACTA2. The residual crosslinkers were washed by immersion of the printed constructs into the basal medium for 30 min, indicating the
preservation of transparency and light transmittance of the 3D-printed cornea. In addition, iPSC-derived cardiomyocytes encapsulated in the heart-derived dECM
(hdECM) bioinks with crosslinker maintained their viability higher than 80% at day 2, with the similar level of cardiac-specific marker gene expression such as cTnT,
MYH6, CACNA1A, and ATP2A2 to that of the control group. Taken together, the visible-light activated dECM bioinks enable bioprinting of tissue constructs with
complex and scalable geometry and biofunctional capacity emulating native tissues, which may serve as a platform for a wider biofabrication window in the field of
tissue engineering.2
Compressed collagen intermixed with cornea-derived decellularized extracellular matrix providing mechanical and biochemical niches for corneal stroma analogue
No full textCompressed collagen is a promising scaffold for corneal stroma analogue due to its facile incorporation of keratocytes while mimicking the mechanical niche of a native cornea with dense collagen fibrillar structures. However, it does not offer the sufficient biochemical niche crucial for in vivo-like quiescent keratocyte phenotype. In this study, we engineered a scaffold for a corneal stroma analogue that mimics both the mechanical and biochemical niches of the corneal stroma by introducing cornea-derived decellularized extracellular matrix (Co-dECM) to the collagen compression process. The compressed collagen intermixed with Co-dECM (COLEM; Co-dECM content, < 50 wt%) maintained a uniform structure and showed an elastic modulus and tensile strength on the order of 100 kPa, which is comparable with that of conventional compressed collagen. The COLEM with the 50 wt% Co-dECM content was found to possess 2-fold higher amount of the glycosaminoglycans as compared to the compressed collagen. The biochemical components of Co-dECM in the COLEM were verified to significantly promote the expression of quiescent keratocyte-specific genes, i.e., KERA and ALDH3A1, while improving the optical transmittance of the COLEM by reducing the diameter of collagen fibrils. The ability of the COLEM to construct multicellular in vitro corneal tissue was demonstrated by an additional corneal epithelial cell culture. The results support the hypothesis that COLEM has strong potential use in the development of corneal equivalent for in vitro models and tissue transplantation.11Nsciescopu
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Shear-induced alignment of collagen fibrils using 3D cell printing for corneal stroma tissue engineering
No full textThe microenvironments of tissues or organs are complex architectures comprised of structural proteins including collagen. Particularly, the cornea is organized in a lattice pattern of collagen fibrils which play a significant role in its transparency. This paper introduces a transparent bioengineered corneal structure for transplantation. The structure is fabricated by inducing shear stress to a corneal stroma-derived decellularized extracellular matrix bioink based on a 3D cell printing technique. The printed structure recapitulates the native macrostructure of the cornea with aligned collagen fibrils which results in the construction of a highly matured and transparent cornea stroma analog. The level of shear stress, controlled by the various size of the printing nozzle, manipulates the arrangement of the fibrillar structure. With proper parameter selection, the printed cornea exhibits high cellular alignment capability, indicating a tissue-specific structural organization of collagen fibrils. In addition, this structural regulation enhances critical cellular events in the assembly of collagen over time. Interestingly, the collagen fibrils that remodeled along with the printing path create a lattice pattern similar to the structure of native human cornea after 4 weeks in vivo. Taken together, these results establish the possibilities and versatility of fabricating aligned collagen fibrils; this represents significant advances in corneal tissue engineering.11Nsciescopu
Light-activated Decellularized Extracellular Matrix-based Bioinks for Volumetric Tissue Analogs in Centimeter-scale
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