Biological tissue defects are typically characterized by various shaped defects, and they are prone to inflammation and the excessive accumulation of reactive oxygen species. Therefore, it is still urgent to develop functional materials which can fully occupy and adhere to irregularly shaped defects by injection and promote the tissue repair process using antioxidant and anti-inflammatory mechanisms. Herein, in this work, phenylboronic acid modified oxidized hyaluronic acid (OHAPBA) was synthesized and dynamically crosslinked with catechol group modified glycol chitosan (GCHCA) and guar gum (GG) into a hydrogel loaded with curcumin liposomes (Cur-LPs) which were relatively uniformly distributed around 180 nm.
View Article and Find Full Text PDFIt is challenging to treat peripheral nerve injury (PNI) clinically. As the gold standard for peripheral nerve repair, autologous nerve grafting remains a critical limitation, including tissue availability, donor-site morbidity, immune rejection, . Recently, conductive hydrogels (CHs) have shown potential applications in neural bioengineering due to their good conductivity, biocompatibility, and low immunogenicity.
View Article and Find Full Text PDFThis work proposed a novel approach based on principal component analyses (PCAs) to monitor the very early-age hydration of self-compacting concrete (SCC) with varying replacement ratios of fly ash (FA) to cement at 0%, 15%, 30%, 45%, and 60%, respectively. Based on the conductance signatures obtained from electromechanical impedance (EMI) tests, the effect of the FA content on the very early-age hydration of SCCs was indicated by the predominant resonance shifts, the statistical metrics, and the contribution ratios of principal components, quantitatively. Among the three, the PCA-based approach not only provided robust indices to predict the setting times with physical implications but also captured the liquid-solid transition elongation (1.
View Article and Find Full Text PDFThe usage of carbon fiber-reinforced polymer (CFRP) to strengthen cracked steel structures can effectively improve its bear capacity, so it has been extensively used in recent years. The degradation of interfacial bonding is one of the most important factors affecting the durability of CFRP-steel structures under a freeze-thaw(F-T)/wet-dry (W-D) environment. In this study, epoxy resin adhesive (ERA) dog-bone specimens and CFRP-steel double-lap joints (bonded joints) were prepared.
View Article and Find Full Text PDFThe development of cheap and easily available injectable hydrogel is an urgent problem in the field of biomedical engineering. Herein, we used chitosan quaternary ammonium salt and sodium alginate to prepare a dual crosslinking hydrogel. The hydrogel formed in-situ crosslinking and can be injected continuously.
View Article and Find Full Text PDFGreen tea extract epigallocatechin-3-gallate (EGCG), as a kind of natural active compounds, has become a research hotspot in cancer treatment. However, poor stability, low bioavailability and antitumor efficacy limit the application of EGCG. In this study, mesoporous dopamine (MPDA) with high drug loading and good biocompatibility loaded EGCG, garlic extract diallyl trisulfide (DATS) and photosensitizer (indocyanine green, ICG) by π-π stacking and hydrophobic-hydrophobic interaction, and the nano-system involved filling the mesoporous of the MPDA with phase change material (1-tetradecanol, 1-TD) molecules, which acted as a thermosensitive gatekeeper.
View Article and Find Full Text PDFSilicon (Si) nanostructures are widely used in microelectronics and nanotechnology. Brittle to ductile transition in nanoscale Si is of great scientific and technological interest but this phenomenon and its underlying mechanism remain elusive. By conducting in situ temperature-controlled nanomechanical testing inside a transmission electron microscope (TEM), here we show that the crystalline Si nanowires under tension are brittle at room temperature but exhibit ductile behavior with dislocation-mediated plasticity at elevated temperatures.
View Article and Find Full Text PDFThe popular performance profiles and data profiles for benchmarking deterministic optimization algorithms are extended to benchmark stochastic algorithms for global optimization problems. A general confidence interval is employed to replace the significance test, which is popular in traditional benchmarking methods but suffering more and more criticisms. Through computing confidence bounds of the general confidence interval and visualizing them with performance profiles and (or) data profiles, our benchmarking method can be used to compare stochastic optimization algorithms by graphs.
View Article and Find Full Text PDFWe propose and demonstrate optofluidic tunable manipulation of polystyrene microparticles based on the combination of a graded-index fiber (GIF) taper and a microcavity. The tunability on the manipulation length is experimentally explored by changing the balance between the optical force and the microfluidic flow force, as well as by tuning the focus of light emitting from the GIF taper via adjusting the length of an air microcavity. By optimizing the geometric shape of the GIF taper, as well as the flow rate and laser power, a manipulation length of 177 μm is achieved, more than 4 times longer than the state-of-the-art optical fiber tweezers.
View Article and Find Full Text PDFLong manipulation length is critical for optical fiber tweezers to enhance the flexibility of non-contact trapping. In this paper a long manipulation distance of more than 40 μm is demonstrated experimentally by the graded-index fiber (GIF) tweezers, which is fabricated by chemically etching a GIF taper with a large cone angle of 58°. The long manipulation distance is obtained by introducing an air cavity between the lead-in single mode fiber and the GIF as well as by adjusting the laser power in the existence of a constant background flow.
View Article and Find Full Text PDFSeveral stability analyses and stable regions of particle swarm optimization (PSO) have been proposed before. The assumption of stagnation and different definitions of stability are adopted in these analyses. In this paper, the order-2 stability of PSO is analyzed based on a weak stagnation assumption.
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