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•N-DMA, 5-OH-IMI and Of-IMI were dominant among detected NEOs.•Regional, seasonal, gender- and age-related differences in NEOs exposure levels were observed.•Vulnerable and ...occupationally exposed population had higher potential health risks.•The toxicity of both NEOs and their metabolites warrant further investigation.
Neonicotinoids (NEOs) are a class of broad-spectrum insecticides dominant in the global market. They were distributed extensively in the environment and occurred frequently in humans. Potential health effects of NEOs, such as neurological toxicity and diabetes to non-targeted mammals, have raised concerns. This review summarizes analytical methods of NEOs in human samples, their internal exposure levels and composition profiles in urine, blood, hair, breast milk, saliva and tooth samples with global comparisons, and daily NEOs exposure dose and relative health risks.Urinary NEOs levels in Asian populations were substantially higher than those in the U.S. and Europe, which may be due to different dietary patterns and insecticide applications across regions. N-desmethyl acetamiprid, 5-hydroxy-imidacloprid and olefin-imidacloprid were dominant among detected NEOs. NEO metabolites exhibited higher detection frequencies and levels than their parent compounds in humans, while investigations on NEO metabolites remain much limited. Current exposure assessments mainly focused on short-term urine analysis, while biomaterials for long-term monitoring, such as hair, nail and other alternatives, should also be considered. Large-scale epidemiological studies are critically needed to elucidate potential health outcomes associated with NEOs exposure.
•Emerging technologies such as Deep Learning and Internet of Things was introduced.•The technology behind Google Translation was adapted to solve hydrology problem.•Deep learning neural network ...architectures was compared with traditional methods.•Deep learning could be of great use in predicting hydrological time series.
Combined sewer overflow causes severe water pollution, urban flooding and reduced treatment plant efficiency. Understanding the behavior of CSO structures is vital for urban flooding prevention and overflow control. Neural networks have been extensively applied in water resource related fields. In this study, we collect data from an Internet of Things monitoring CSO structure and build different neural network models for simulating and predicting the water level of the CSO structure. Through a comparison of four different neural networks, namely multilayer perceptron (MLP), wavelet neural network (WNN), long short-term memory (LSTM) and gated recurrent unit (GRU), the LSTM and GRU present superior capabilities for multi-step-ahead time series prediction. Furthermore, GRU achieves prediction performances similar to LSTM with a quicker learning curve.
•CO2 can be used as a curing agent to improve performance of cement-based materials.•Mechanisms, processing and material performance associated to carbonation curing are summarized.•Lower energy ...minerals and suitable wastes can be activated by CO2 as raw building materials.•Perpetual CO2 sequestration mitigates carbon footprint of construction industry.
Carbonation for the curing of cement-based materials has been gaining increased attention in recent years, especially in light of emerging initiatives regarding carbon emissions. This article reviews the status quo of the carbonation curing process with insight into the approach’s scientific premise, industrial scalability, and commercial spin-offs. Calcium-silicate-based binders, such as Portland cement and its lower energy alternatives, experience very rapid hardening when adequately moistened and exposed to high concentrations of carbon dioxide. Concretes processed as such display improved physical performance and better overall resistance to freeze-thaw cycles, sulfate salts, and acids. In addition to binder activation, carbonation’s valorizing potential can also be exploited to recycle suitable industrial wastes into raw building materials. The perpetual fixation of carbon dioxide in building products conduces a more sustainable stance for the concrete industry as it fulfills mandates for lower carbon footprint. In this article, topics relevant to carbonation curing including reaction mechanisms, processing and impacts on material performance and sustainability are comprehensively reviewed. Further laboratory and industrial research are also proposed.
Engineered Cementitious Composites (ECC) have demonstrated superior mechanical and durability performance than conventional concrete. In the micromechanical reinforcing system of ECC, fibers play a ...pivotal role in establishing the ultrahigh tensile ductility and autogenous crack width control. This article reviews the state-of-the-art of discontinuous micro-fibers as intrinsic reinforcement of ECC regarding technical performance as well as environmental and economic impacts. Mechanical properties of ECC made with different micro-fibers, man-made or natural, and their embodied energy, emissions and material cost, are comprehensively surveyed. Further, studies on fiber hybridization are discussed regarding the combination of different types of fibers to form synergetic reinforcements that mitigate total material cost, and potentially enhance the composite performance. Recommendations on fiber selections are highlighted and directions for future research are suggested.
An efficient photocatalytic functionalization of compounds with benzylic C−H bonds by sulfoximidation in visible light is described. The mild reaction conditions allow the use of a broad array of ...substrates, including diarylmethane, alkyl arenes, arylacetonitrile, 2‐arylacetate, and alkynyl aryl methanes. The sulfoximidation process is highly chemoselective and leads to the corresponding sulfoximines in generally good yields. Mechanistic investigations suggested the intermediacy of sulfoximidoyl radicals.
Benzylic C−H bonds were selectively functionalized through photoredox catalysis starting from a sulfoximidoyl‐containing hypervalent iodine(III) reagent. The process is highly chemoselective and allows the conversion of a broad range of substrates. Mechanistic studies suggest the intermediacy of a sulfoximidoyl radical. Conceptionally, this represents a new approach towards sulfoximines.
Exosomes are nanovesicles secreted by cells and contain various molecules including protein, lipid, and DNA/RNA. They are crucial mediators of the intercellular communication and serve as promising ...vehicles for drug delivery and gene therapy. Recently, accumulating evidence suggests that microRNAs (miRNAs) may serve as new and potentially powerful targets for therapeutic interventions against various human diseases. However, steadily and effectively delivering miRNA mimics or inhibitors to target cells remains a major obstacle. To enhance the efficacy of exosome-mediated delivery of miRNA molecules, it is crucial to develop a convenient and efficient method to enrich specific miRNAs or antisense oligos in isolated exosomes. Here we report a novel method to prepare specific miRNA molecule-loaded exosomes. Using a modified calcium chloride-mediated transfection method, we successfully enhanced the designated miRNA mimics or inhibitors in isolated exosomes directly, instead of transfecting their mother cells. We also compared this method with direct transfection of exosomes using electroporation. Both methods confirmed that exosomes can serve as cargos to deliver a robustly increased amount of selected miRNA mimic(s) or inhibitor(s) to the recipient cells. Delivery of these miRNA molecule enriched-exosomes subsequently results in highly efficient overexpression or deletion of the designated miRNAs in the recipient cells both in vivo and in vitro. Additionally, we confirmed that exosome-delivered miRNA mimics or inhibitors are functional in the recipient cells. Collectively, we developed a novel protocol to conveniently manipulate exosomal miRNAs with high efficiency and successfully deliver the exosomal miRNA molecules to recipient cells.
•CO2 curing enhances surface scaling resistance of concretes with/without fly ash.•Concrete early strength is improved by CO2 curing.•CO2 curing refines pore structure of cement pastes and ...concretes.•Refinement of pore structure by CO2 curing maintains with subsequent hydration.
Surface scaling of concrete is one of the major durability issues for cold-region concrete materials. This study presents a solution of using CO2 curing to mitigate the concrete surface salt scaling induced by the freeze-thaw exposure. A laboratory freeze-thaw cyclic test was performed on the concrete made with Portland cement and fly ash. To understand the underlying mechanism, the pore structure of cement paste was evaluated by mercury intrusion porosimetry (MIP) and nitrogen adsorption/desorption (NAD). It was found that the total pore volume and pore size were noticeably reduced in the CO2-cured samples. CO2 curing leads to a dramatic refinement of the capillary pores, hence lessening the available microporous space for the ice formation. The densified concrete surface accounts for the enhanced resistance to the surface scaling.
Corrosion by seawater is an electrochemical Corrosion, and all types of metals or alloys when they are in contact with seawater have a specific corrosion potential at a certain level of seawater ...alkalinity or acidity. Metal corrosion is a major technical problem and plenty of methods have been developed to provide solution. Inhibitor-enhanced coating can be recognized as the most efficient method. In this research, Halloysite nanotube (HNT) was used to create HNT-epoxy composite as protection towards corrosion without the inhibitor. The electrochemical impedance spectroscopy (EIS) study was done on HNT-epoxy composite coatings for corrosion protection carbon steel in 3.5% NaCl solution. The morphology analysis of the HNT was done by optical microscope and field emission scanning electron microscope(FESEM). The EIS characterizations showed a turning point of the composite coating from good to poor corrosion resistance performance. According to EIS measurements, increasing the halloysite concentration had resulted in the enhancement of the barrier effect and an increase in the ability to protect corrosion coating in NaCl solution. The corrosion morphology observations indicated that an increase in nanoparticle loading lead to an increase in the intercalation site and make the composite opaquer. Furthermore, the nanoparticles loading showed poor interaction with the epoxy composite, due to clustering of the nanoparticles and visible as wavy opaque surface. The findings show that the HNT is a very good alternative as a corrosion barrier in coating due to their viability and compatibility with diversity of water- and oil- based coatings onto a protected surface.
Hericium erinaceus (H. erinaceus), an edible mushroom with medicinal value, has a long history of usage in China and other oriental countries. Polysaccharide is supposed to be one of the major ...bioactive compounds in H. erinaceus, which possesses immunomodulating, anti-cancer, antioxidant, gastroprotection and intestinal health promotion, neuroprotective, hepatoprotective, antihpyerglycemic and hypolipidemic activities. In this review, the current advancements on extraction, purification, structural characteristics and biological activities of polysaccharide from different sources (fruiting body, mycelium and culture broth) of H. erinaceus were summarized. Among these aspects, summaries of the structural characteristics focused on the purified polysaccharides. Meanwhile, comparisons on the structural characteristics among the purified polysaccharides obtained from above three sources were made. Moreover, their biological activities were introduced on the basis of in vivo and in vitro experiments, and some possible action mechanisms were listed. Furthermore, the structure-activity relationship of the polysaccharide was discussed. New perspectives for the future work of Hericium erinaceus polysaccharide were also proposed.
HIGHLIGHTS
Extraction, purification, structural characteristics and biological activities of Hericium erinaceus polysaccharide (HEP) were summarized.
Structural characteristics of the purified polysaccharides from different sources (fruiting body, mycelium and culture broth) of Hericium erinaceus were summarized and compared.
Structure-activity relationship of HEP was discussed, and new perspectives for the future work of this polysaccharide were proposed.
Geometric approximation errors of periodically distributed surface facets of cable-network reflector antennas can result in grating lobes undesired in some space missions. As the surface is shaped by ...the tensioned flexible cable-network structure, the electromagnetic (EM) and structural parameters are highly correlated, and the well-designed surface obtained only concerning the EM performance may not be shaped by the tension-only cable network with specified cable-tension constraints. To address the problem, this study proposes an integrated structural-EM optimization method to enable low grating lobe cable-network antenna design. In this method, force densities of the cables, which can determine both the cable tensions and surface node positions that decide the boundary conditions of the EM field, are selected as the design variables. An adaptive objective/constraint function is proposed, which enables the grating lobe level (GLL) to be minimized with constrained cable tensions, antenna gain, and first sidelobe level (SLL) in a simultaneous, feasible and relatively fast way. To demonstrate the feasibility and effectiveness of the proposed method, it was implemented on a 12 m-diameter cable-network antenna. The results indicate that the grating lobes are greatly degraded and the achieved surface can be formed by well tensioned cables.
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