A Danger-Theory-Based Immune Network Optimization Algorithm

Existing artificial immune optimization algorithms reflect a number of shortcomings, such as premature convergence and poor local search ability. This paper proposes a danger-theory-based immune network optimization algorithm, named dt-aiNet. The danger theory emphasizes that danger signals generated from changes of environments will guide different levels of immune responses, and the areas around danger signals are called danger zones. By defining the danger zone to calculate danger signals for each antibody, the algorithm adjusts antibodies’ concentrations through its own danger signals and then triggers immune responses of self-regulation. So the population diversity can be maintained. Experimental results show that the algorithm has more advantages in the solution quality and diversity of the population. Compared with influential optimization algorithms, CLONALG, opt-aiNet, and dopt-aiNet, the algorithm has smaller error values and higher success rates and can find solutions to meet the accuracies within the specified function evaluation times

Microfluidic mass production of stabilized and stealthy liquid metal nanoparticles

Functional nanoparticles comprised of liquid metals, such as eutectic gallium indium (EGaIn) and Galinstan, present exciting opportunities in the fields of flexible electronics, sensors, catalysts, and drug delivery systems. Methods used currently for producing liquid metal nanoparticles have significant disadvantages as they rely on both bulky and expensive high-power sonication probe systems, and also generally require the use of small molecules bearing thiol groups to stabilize the nanoparticles. Herein, we describe an innovative microfluidics-enabled platform as an inexpensive, easily accessible method for the on-chip mass production of EGaIn nanoparticles with tunable size distributions in an aqueous medium. We also report a novel nanoparticle-stabilization approach using brushed polyethylene glycol chains with trithiocarbonate end-groups negating the requirements for thiol additives whilst imparting a ‘stealth’ surface layer. Furthermore, we demonstrate a surface modification of the nanoparticles using galvanic replacement, and conjugation with antibodies. We envision that the demonstrated microfluidic technique can be used as an economic and versatile platform for the rapid production of liquid metal-based nanoparticles for a range of biomedical applications.

Author Correction:3D-printed liquid metal polymer composites as NIR-responsive 4D printing soft robot

Correction to: Nature Communications https://doi.org/10.1038/s41467-023-43667-4, published online 28 November 2023

Multi-source excited travelling-wave bowtie antenna based on a meander series of YBCO bicrystal Josephson junctions

Series superconducting Josephson junctions (JJs), as terahertz (THz) mixers, have attracted increasing attentions due to their advantages in solving the saturation problem of superconducting mixers, achieving higher mixing harmonics and higher sensitivity in THz band. However, the normal-state resistances of the series JJs are so low that there exists an impedance mismatch between the coupled antenna and the JJs. In this paper, a meander embedding travelling-wave bowtie antenna is proposed for a series of bicrystal JJs. With this antenna, not only the problem of impedance mismatch can be solved, but also more series JJs can be inserted into the antenna. Five and even seven series JJs in the meander match the proposed antenna well. Furthermore, combined current distribution, far-field radiation patterns and parameter study are investigated in the numerical simulation to analyze this antenna

Pathological Tau From Alzheimer’s Brain Induces Site-Specific Hyperphosphorylation and SDS- and Reducing Agent-Resistant Aggregation of Tau in vivo

Neurofibrillary tangles (NFTs) made up of hyperphosphorylated tau are a histopathological hallmark of Alzheimer’s disease (AD) and related tauopathies. Hyperphosphorylation of tau is responsible for its loss of normal physiological function, gain of toxicity and its aggregation to form NFTs. Injection of misfolded tau seeds into mouse brain induces tau aggregation, but the nature of tau phosphorylation in pathologic tau seeded pathology is unclear. In the present study, we injected hyperphosphorylated and oligomeric tau isolated from AD brain (AD P-tau) into hippocampus of human tau transgenic mice and found that in addition to tau aggregation/pathology, tau was hyperphosphorylated at Ser202/Thr205, Thr212, Ser214, Thr217, Ser262, and Ser422 in AD P-tau injected hippocampus and at Ser422 in the contralateral hippocampus and in the ipsilateral cortex. AD P-tau-induced AD-like high molecular weight aggregation of tau that was SDS- and reducing agent-resistant and site-specifically hyperphosphorylated in the ipsilateral hippocampus. There were no detectable alterations in levels of tau phosphatases or tau kinases in AD P-tau-injected brains. Furthermore, we found that hyperphosphorylated tau was easier to be captured by AD P-tau and that aggregated tau was more difficult to be dephosphorylated than the non-aggregated tau by protein phosphatase 2A (PP2A). Based on these findings, we speculate that AD P-tau seeds hyperphosphorylated tau to form aggregates, which resist to the dephosphorylation by PP2A, resulting in hyperphosphorylation and pathology of tau

Liquid metal particles and polymers: a soft-soft system with exciting properties

Conspectus Gallium-based liquid metal alloys are a special type of material that is in the liquid state at (or near) room temperature. They are particularly attractive due to their unique combination of a fluidic and metallic body, together with a chemically reactive and functionable surface. As a fluid, liquid metals provide the best union of stretchability, deformability, and electrical conductivity among all soft materials. Such an advantage in combination with their low toxicity and relatively good biocompatibility have imparted liquid metals with unique features that can be harnessed for versatile applications in fields such as electronics, energy, chemistry, and biomedical research. More importantly, the fluidic nature of liquid metals allows them to be readily processed using shear for making particles with variable sizes (from nm to mm), which is not possible with solid materials. These particles have a liquid metal core-solid metal oxide shell (conductor-semiconductor) structure, allowing them to merge, transform shape, change phase, respond to stimuli, and self-heal.Despite these unique features, limited surface stability and functionality, unpredictable reactivity, and uncontrollable hydrophilicity of liquid metal particles niche their wider applications in biomedical fields. To bestow liquid metal particles with desirable surface properties while taking the benefits offered by soft features, another important soft material-polymers-can be synthesized and engineered on an on-demand basis to coat or embed liquid metal particles. This leads to the formation of liquid metal-polymer soft composites with versatile surface properties. More specifically, polymer segments with corresponding functions for surface anchoring, tuning solubility, enhancing biocompatibility, providing stimuli-responsive properties, and further bioconjugation can be linked together, thereby forming macromolecules to graft liquid metal particles for yielding soft-soft systems with exciting properties.Herein, we provide a concise review of our contributions to the production, investigation, characterization, and application of liquid metal particle-polymer composites. First, we summarize various top-down techniques developed for producing micro- to nanosized liquid metal particles. We highlight two platforms we developed for tackling long-existing problems encountered by sonication-the most widely adopted method for producing liquid metal particles. Second, we discuss the design of polymers for surface modification of particles. Various grafting strategies for polymers synthesized using different approaches are elaborated. We also discuss factors that affect the colloidal and chemical stability of the composite in biological buffers. Methods for further surface functionalization of the composite are presented, followed by providing examples of biomedical and sensing applications for the system. Next, we introduce the fabrication, unique properties, and applications of elastomeric hybrid composites incorporating liquid metal particle fillers. Finally, we offer a perspective on the opportunities and challenges for the future development of this exciting soft-soft system for realizing synergistic outcomes.</p

Modular and Integrated Systems for Nanoparticle and Microparticle Synthesis-A Review

Nanoparticles (NPs) and microparticles (MPs) have been widely used in different areas of research such as materials science, energy, and biotechnology. On-demand synthesis of NPs and MPs with desired chemical and physical properties is essential for different applications. However, most of the conventional methods for producing NPs/MPs require bulky and expensive equipment, which occupies large space and generally need complex operation with dedicated expertise and labour. These limitations hinder inexperienced researchers to harness the advantages of NPs and MPs in their fields of research. When problems individual researchers accumulate, the overall interdisciplinary innovations for unleashing a wider range of directions are undermined. In recent years, modular and integrated systems are developed for resolving the ongoing dilemma. In this review, we focus on the development of modular and integrated systems that assist the production of NPs and MPs. We categorise these systems into two major groups: systems for the synthesis of (1) NPs and (2) MPs; systems for producing NPs are further divided into two sections based on top-down and bottom-up approaches. The mechanisms of each synthesis method are explained, and the properties of produced NPs/MPs are compared. Finally, we discuss existing challenges and outline the potentials for the development of modular and integrated systems

Peroxidase-triggered formation of fluorescent peptide-based nanoarchitectonics

Fluorescent dye labeled peptides and oligonucleotides are important tools for biochemical and cellular research. Dityrosine bond is easily formed in vitro and shows blue fluorescence, so it can be used as a useful symbol of oxidation conditions in biological systems. The formation of dityrosine can be carried out by enzymatic reaction, Fenton reaction and photoinitiation reaction. The enzymatic reaction has attracted much attention because of its mild reaction conditions, which can be performed at room temperature and pressure, and the reaction rates are faster than the corresponding non-catalytic reaction. In this study, peroxidase is selected to catalyze the dipeptides containing tyrosine, resulting nanostructures containing dipeptides with stable blue fluorescence under mild conditions. Nanostructured peptides with stable fluorescence can be applied to fluorescent labeling, and the reaction catalyzed by enzymes to produce blue fluorescence can be used as candidates for lighting inflammatory cells and designing visual materials