Various types of structures self-organised by animals exist in nature, such as bird flocks and insect swarms, which stem from the local communications of vast numbers of limited individuals. Through ...the designing of algorithms and wireless communication, robotic systems can emulate some complex swarm structures in nature. However, creating a swarming robotic system at the microscale that embodies functional collective behaviours remains a challenge. Herein, we report a strategy to reconfigure paramagnetic nanoparticles into ribbon-like swarms using oscillating magnetic fields, and the mechanisms are analysed. By tuning the input fields, the microswarm can perform a reversible elongation with an extremely high aspect ratio, as well as splitting and merging. Moreover, we investigate the behaviours of the microswarm when it encounters solid boundaries, and demonstrate that under navigation, the colloidal microswarm passes through confined channel networks towards multiple targets with high access rates and high swarming pattern stability.
Micromachines with controllable motion, deformation, and collective behaviors provide advanced methods for performing tasks that traditional machines have difficulty completing thanks to the ...development of small-scale robotics, nanotechnology, biocompatible materials, and imaging techniques ...
HBO1 complexes are major acetyltransferase responsible for histone H4 acetylation in vivo, which belongs to the MYST family. As the core catalytic subunit, HBO1 consists of an N-terminal domain and a ...C-terminal MYST domain that are in charge of acetyl-CoA binding and acetylation reaction. HBO1 complexes are multimeric and normally consist of two native subunits MEAF6, ING4 or ING5 and two kinds of cofactors as chromatin reader: Jade-1/2/3 and BRPF1/2/3. The choices of subunits to form the HBO1 complexes provide a regulatory switch to potentiate its activity between histone H4 and H3 tails. Thus, HBO1 complexes present multiple functions in histone acetylation, gene transcription, DNA replication, protein ubiquitination, and immune regulation, etc. HBO1 is a co-activator for CDT1 to facilitate chromatin loading of MCM complexes and promotes DNA replication licensing. This process is regulated by mitotic kinases such as CDK1 and PLK1 by phosphorylating HBO1 and modulating its acetyltransferase activity, therefore, connecting histone acetylation to regulations of cell cycle and DNA replication. In addition, both gene amplification and protein overexpression of HBO1 confirmed its oncogenic role in cancers. In this paper, we review the recent advances and discuss our understanding of the multiple functions, activity regulation, and disease relationship of HBO1.
Various types of nanocellulose have been isolated from the cellulosic feedstock. It was expected that nanocellulose could be used to replace fossil-based plastic in certain areas because it is ...biodegradable, biocompatible, environment-friendly, and has outstanding performance. Unlike conventional plastic processing, nanocellulose is generally isolated and processed in aqueous environments. Therefore, dewatering and drying are essential unit operations for nanocellulose processing. Different drying methods for colloidal nanocellulose suspension mediated different self-assembly behaviors and thus resulted in different nanocellulose morphology and physical properties. The most utilized techniques for nanocellulose processing, such as spinning, vacuum/pressurized filtration, solvent casting and roll to roll casting, coating and roll to roll coating, and additive manufacturing are investigated. Process parameters such as temperature, pH, ion species, concentration, and external electrical field, affect the orientation and assembly behavior of nanocellulose, which in turn influence the properties of the prepared materials. Therefore, the method for assembling nanocellulose into bulk materials in a controlled way is vital for the properties of the fabricated nanocellulose composites. Here, some of the recent advances in the processing of nanocellulose for bulk materials are reviewed.
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Transition metal phosphides (TMPs) have been received widespread research attention and developed as electrode materials for their superior electrical conductivity and excellent redox activity. In ...this work, self-supported three-dimensional hierarchical core-shell NiCoP@NiCoP@CC electrode has been fabricated by a two-step hydrothermal and a phosphorization method, in which NiCoP@NiCoP core-shell leaf-like arrays are directly grown on carbon cloth. The electrode integrates the advantages of the 1D core for “hyperchannel” of the electron transport, 2D shell on core for a short diffusion distance for the ions and also the charge carrier meanwhile improvement of cycle stability, and 3D networked substrate for flexibility. The as-fabricated electrode shows superior electrochemical performance and delivers a high specific capacity of 1125 C g−1 (312 mAh g−1) at 1 A g−1, and outstanding rate capability with 78.0% retention even at 10 A g−1 and still retain 808 C g−1 (224 mAh g−1) (71.8% retention) after 2000 cycles. In addition, the asymmetric supercapacitor has also been assembled for actual use by employing NiCoP@NiCoP electrode as the anode and the activated carbon (AC) as the cathode, which displays a voltage window of 1.5 V and a high energy density of 34.8 Wh kg−1 at a power density of 750.0 W kg−1. The results demonstrate feasibility of NiCoP@NiCoP core-shell array on carbon cloth as electrode material for high performance hybrid supercapacitor applications.
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•Arbuscular mycorrhizal fungi (AM fungi) directly or indirectly alleviate heavy metal in host plant.•AM fungi improve nutrient uptake, plant biomass and antioxidants under heavy metal ...stress in the host plant.•AM fungi remediate heavy metal by accumulating large part of heavy metals in fungal structures.
The heavy metal pollution is a worldwide problem and has received a serious concern for the ecosystem and human health. In the last decade, remediation of the agricultural polluted soil has attracted great attention. Phytoremediation is one of the technologies that effectively alleviate heavy metal toxicity, however, this technique is limited to many factors contributing to low plant growth rate and nature of metal toxicities. Arbuscular mycorrhizal fungi (AMF) assisted alleviation of heavy metal phytotoxicity is a cost-effective and environment-friendly strategy. AMF have a symbiotic relationship with the host plant. The bidirectional exchange of resources is a hallmark and also a functional necessity in mycorrhizal symbiosis. During the last few years, a significant progress in both physiological and molecular mechanisms regarding roles of AMF in the alleviation of heavy metals (HMs) toxicities in plants, acquisition of nutrients, and improving plant performance under toxic conditions of HMs has been well studied. This review summarized the current knowledge regarding AMF assisted remediation of heavy metals and some of the strategies used by mycorrhizal fungi to cope with stressful environments. Moreover, this review provides the information of both molecular and physiological responses of mycorrhizal plants as well as AMF to heavy metal stress which could be helpful for exploring new insight into the mechanisms of HMs remediation by utilizing AMF.
Polylactic acid (PLA) is one of the most promising biodegradable and recyclable thermoplastic biopolymer derived from renewable feedstock. Nanocellulose reinforced PLA biocomposites have received ...increasing attention in academic and industrial communities. In the present study, cellulose nanofibrils (CNFs) was liberated by combined enzymatic pretreatment and high-pressure homogenization, and then subsequently incorporated into the PLA matrix to synthesize PLA/CNF biocomposite films via solution casting and melt compression. The prepared PLA/CNF biocomposite films were characterized in terms of transparency (UV-Vis spectroscopy), chemical structure (attenuated total reflectance-Fourier transform infrared, ATR-FTIR; X-ray powder diffraction, XRD), thermal (thermogravimetric analyzer, TGA; differential scanning calorimetry, DSC), and tensile properties. With 1.0-5.0 wt % additions of CNF to the PLA matrix, noticeable improvements in thermal and physical properties were observed for the resulting PLA/CNF biocomposites. The 2.5 wt % addition of CNF increased the tensile strength by 8.8%. The T
(initial degradation temperature) and T
(maximum degradation temperature) after adding 5.0 wt % CNF was increased by 20 °C, and 10 °C, respectively in the nitrogen atmosphere. These improvements were attributed to the good dispersibility and improved interfacial interaction of CNF in the PLA matrix.
An ultrasensitive photoelectrochemical (PEC) aptasensor was designed for detection of chloramphenicol (CAP) based on graphene quantum dots-sensitized TiO2 nanotube arrays (GQDs/TiO2 NTs). The ...GQDs/TiO2 NTs nanohybrids were prepared by a coupling technique of linker molecule binding and electrophoretic deposition. It exhibited significantly enhanced visible-light photoelectrochemical activity, which was firstly employed as the photoactive material for fabrication of PEC aptasensor. As the recognition unit, the aptamers of CAP were immobilized on GQDs/TiO2 NTs photoelectrode via π–π stacking interaction between GQDs and the nucleobases of the aptamer. In this signal-on proposal, the aptasensor was used for the label-free analysis of CAP by monitoring the increase in photocurrent that resulted from the formation of aptamer-CAP bioaffinity complexes with ascorbic acid as an efficient electron donor for scavenging photogenerated holes. Under the optimized conditions, the aptasensor showed a wide linear range from 0.5 nM to 100 nM for CAP detection with a low detection limit of 57.9 pM (S/N = 3). With good selectivity and sensitivity, the PEC aptasensor was applied to the determination of CAP in spiked honey samples with satisfactory results, suggesting that the GQDs/TiO2 NTs photoelectrode has a promising application in constructing PEC sensor platform.
A novel visible-light driven photoelectrochemical aptasensor based on graphene quantum dots-sensitized TiO2 nanotube arrays has been fabricated and used for the determination of chloramphenicol with good selectivity and high sensitivity. Display omitted
•A “signal-on” PEC aptasensor based on GQDs/TiO2 NTs was developed.•The GQDs/TiO2 NTs nanohybrids significantly improve photocurrent response.•The aptasensor exhibits high sensitivity for chloramphenicol detection.•The proposed method can be used in food safety detection.
•Location of polluted nearshore waters coincided with SGD hotspots on a local scale.•SGD-driven nutrients were one order of magnitude higher than riverine inputs in China.•Nutrients via SGD ...contributed >50% of the total sources to Chinese coastal waters.•SGD influences coastal water quality and nutrient budgets at small and large scales.
Submarine groundwater discharge (SGD) can be a significant source of chemical pollutants from land to ocean. Here, we first estimated SGD using radium isotopes and related nutrient fluxes at the local scale in Jiaozhou Bay (JZB), a typical Chinese system that is experiencing rapid urban and industrial development. We then summarized SGD studies off China to assess the large-scale implications of SGD to nutrient budgets. In JZB, the location of contaminated nearshore waters revealed by an integrative water quality index (WQI) coincided with the SGD hotspots. The total (fresh and saline) SGD flux in JZB was estimated to be (0.64–1.67) × 107 m3/d or (2.12–5.59) cm/d based on 224Ra and 228Ra mass balance models. This was approximately 8 times the discharge rate of local rivers. By combining these JZB results with the literature data, we provide the first estimate of SGD and associated nutrient fluxes off China. The magnitude of SGD at the China-scale was (5.40–10.2) × 1012 m3/yr, accounting for 5–9% of the global SGD flux. SGD-derived nutrient fluxes summarized from ∼40 previous studies were one order of magnitude higher than riverine inputs. These nutrients fluxes from SGD contributed >50% of the total dissolved inorganic nitrogen (DIN), phosphorous (DIP) and silicate (DSi) inputs into Chinese coastal waters, which can explain about 60% of the phosphorus required by primary production. The mean DIN/DIP ratio (121) in SGD was significantly higher than the Redfield ratio, with important implications for phytoplankton growth and structure. SGD can influence water quality, dominate nutrient budgets, and drive primary production not only at the local scale, but also at the regional and global scales.
In nature, various types of animals will form self-organised large-scale structures. Through designing wireless actuation methods, microrobots can emulate natural swarm behaviours, which have drawn ...extensive attention due to their great potential in biomedical applications. However, as the prerequisite for their in-vivo applications, whether microrobotic swarms can take effect in bio-fluids with complex components has yet to be fully investigated. In this work, we first categorise magnetic active swarms into three types, and individually investigate the generation and navigation behaviours of two types of the swarms in bio-fluids. The influences of viscosities, ionic strengths and mesh-like structures are studied. A strategy is then proposed to select the optimised swarms in different fluidic environments based on their physical properties, and the results are further validated in various bio-fluids. Moreover, we also realise the swarm generation and navigation in bovine eyeballs, which also validates the proposed prediction in the ex-vivo environment.
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