Microplastic pollution is increasingly becoming a great environmental concern worldwide. Microplastics have been found in many marine organisms as a result of increasing plastic pollution within ...marine environments. However, the relationship between micoplastics in organisms and their living environment is still relatively poorly understood. In the present study, we investigated microplastic pollution in the water and the mussels (Mytilus edulis, Perna viridis) at 25 sites along the coastal waters of China. We also, for the first time, conducted an exposure experiment in parallel on the same site using M. edulis in the laboratory. A strong positive linear relationship was found between microplastic levels in the water and in the mussels. Fibers were the dominant microplastics. The sizes of microplastics in the mussels were smaller than those in the water. During exposure experiments, the abundance of microbeads was significantly higher than that of fibers, even though the nominal abundance of fibers was eight times that of microbeads. In general, our results supported positive and quantitative correlations of microplastics in mussels and in their surrounding waters and that mussels were more likely to ingest smaller microplastics. Laboratory exposure experiment is a good way to understand the relative impacts of microplastics ingested by marine organisms. However, significant differences in the results between exposure experiments and field investigations indicated that further efforts are needed to simulate the diverse environmentally relevant properties of microplastics.
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•The abundance of microplastics in mussels depended on those in water.•Fibers accounted for >60% of the microplastics in field investigations.•Mussels were more likely to ingest smaller rather than larger microplastics.•The abundances and types of microplastic ingestion between field and laboratory observations were different.
High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal elements. Although in the infant ...stage, the emerging of this new family of materials has brought new opportunities for material design and property tailoring. Distinct from metals, the diversity in crystal structure and electronic structure of ceramics provides huge space for properties tuning through band structure engineering and phonon engineering. Aside from strengthening, hardening, and low thermal conductivity that have already been found in high-entropy alloys, new properties like colossal dielectric constant, super ionic conductivity, severe anisotropic thermal expansion coefficient, strong electromagnetic wave absorption, etc., have been discovered in HECs. As a response to the rapid development in this nascent field, this article gives a comprehensive review on the structure features, theoretical methods for stability and property prediction, processing routes, novel properties, and prospective applications of HECs. The challenges on processing, characterization, and property predictions are also emphasized. Finally, future directions for new material exploration, novel processing, fundamental understanding, in-depth characterization, and database assessments are given.
Chiral propargyl amines are valuable synthetic intermediates for the preparation of biologically active compounds and functionalized amines. Catalytic methods to access propargyl amines containing ...vicinal stereocenters with high diastereoselectivity are particularly rare. We report an unprecedented strategy for the synthesis of enantioenriched propargyl amines with two stereogenic centres. An iridium complex, ligated by a phosphoramidite ligand, catalyzes the hydroalkynylation of β,β‐disubstituted enamides to afford propargyl amides in a highly regio‐, diastereo‐, and enantioselective fashion. Stereodivergent synthesis of all four possible stereoisomers was achieved using this strategy.
One for all: A hydroalkynylation method for the synthesis of enantioenriched propargyl amines with two stereogenic centers was developed. The Ir‐catalyzed hydroalkynylation of β,β‐disubstituted enamides proceeds to give propargyl amides in a highly regio‐, diastereo‐, and enantioselective fashion. Stereodivergent synthesis of all four possible stereoisomers was achieved using this strategy.
Plastic pollution is a growing global concern. In the present study, we investigated plastic pollution in 21 species of sea fish and 6 species of freshwater fish from China. All of the species were ...found to ingest micro- or mesoplastics. The average abundance of microplastics varied from 1.1 to 7.2 items by individual and 0.2–17.2 items by gram. The average abundance of mesoplastics varied from 0.2 to 3.0 items by individual and 0.1–3.9 items by gram. Microplastics were abundant in 26 species, accounting for 55.9–92.3% of the total number of plastics items in each species. Thamnaconus septentrionalis contained the highest abundance of microplastics (7.2 items/individual). The average abundance of plastics in sea benthopelagic fishes was significantly higher than in freshwater benthopelagic fishes by items/individual. The plastics were dominanted by fiber in shape, transparent in color and cellophane in composition. The proportion of plastics in the stomach to the intestines showed great variation in different species, ranging from 0.5 to 1.9 by items/individual. The stomach of Harpodon nehereus and intestines of Pampus cinereus contained the highest number of plastics, (3.3) and (2.7), respectively, by items/individual. Our results suggested that plastic pollution was widespread in the investigated fish species and showed higher abundance in comparison with worldwide studies. The ingestion of plastics in fish was closely related to the habitat and gastrointestinal tract structure. We highly recommend that the entire gastrointestinal tract and digestion process be used in future investigations of plastic pollution in fish.
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•Plastic pollution was widespread in sea fishes and freshwater fishes from China.•The occurrence of microplastics was dominant in fishes.•Plastics in the stomach and intestine showed great variation in different species.•We recommend the entire GIT should be used in fish.
High levels of plastics occurred not only in the stomach but also in the intestines of fishes from China.
Microplastics are plastics that measure less than 5 mm in diameter. They enter the marine environment as primary sources directly from industrial uses, as well as secondary sources resulting from the ...degradation of large plastic debris. To improve the knowledge of microplastic pollution in China, we investigated samples from 53 estuarine sediment locations collected with a box corer within the Changjiang Estuary. Microplastics (<5 mm) were extracted from sediments by density separation, after which they were observed under a microscope and categorized according to shape, color and size. Identification was carried out using Micro-Fourier-Transform Infrared Spectroscopy (μ-FT-IR).
The abundance of microplastics in the Changjiang Estuary was mapped. The mean concentration was 121 ± 9 items per kg of dry weight, varying from 20 to 340 items per kg of dry weight. It was found that the concentration of microplastics was the highest on the southeast coast of Shanghai. The distribution pattern of microplastics may be affected by the Changjiang diluted water in summer. All of the microplastics collected were categorized according to shape, color and size. Among which fiber (93%), transparent (42%) and small microplastics (<1 mm) (58%) were the most abundant types. No clear correlation between microplastics and the finer sediment fraction was found. Rayon, polyester, and acrylic were the most abundant types of microplastics identified, indicating that the main source of microplastics in the Changjiang Estuary was from washing clothes (the primary source). It is possible to compare microplastic abundance in this study with the results of other related studies using the same quantification method. The identification of microplastics raises the awareness of microplastic pollution from drainage systems. The prevalence of microplastic pollution calls for monitoring microplastics at a national scale on a regular basis.
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•Microplastic concentration varied from 20 to 340 items/kg dry weight in the sediments of the Changjiang Estuary.•The average concentration was 121 items/kg dry weight.•Fiber, transparent and small microplastics (<1 mm) were the most abundant types.•Rayon, polyester and acrylic were the most abundant types according to identification results.•The source of microplastics in sediments of the Changjiang Estuary may be from washing clothes.
Microplastic concentration in sediments of the Changjiang Estuary varied from 20 to 340 items per kg of dry weight.
•Microplastics were isolated from specific organs of mussels.•The abundance of microplastic by weight differed in organs of field mussels.•Microfibers were observed in foot and mantle of mussels in ...uptake and clearance experiments.•Adherence contributed about 50% of the microplastic uptake in mussels.•Adherence is a novel way for animals to uptake microplastics beyond ingestion.
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Microplastic pollution is recognized as an emerging threat to aquatic ecosystems. One of the main environmental risks associated with microplastics is their bioavailability to marine organisms. Up to date, ingestion has been widely accepted as the sole way for the animals to uptake microplastics. Nevertheless, microplastics have also been found in some organs which are not involved in the process of ingestion. We hypothesize that the animal might uptake microplastics through adherence in addition to ingestion. To test this hypothesis, we collected mussels from the fishery farms, conducted exposure/clearance experiments and analyzed the accumulation of microplastics in specific organ of mussels. Our studies clearly showed the uptake of microplastic in multiple organs of mussels. In the field investigations, we found that the abundance of microplastic by weight but not by individual showed significant difference among organs, and the intestine contained the highest level of microplastics (9.2items/g). In the uptake and clearance experiment, the accumulation and retention of microfibers could also be observed in all tested organs of mussels including foot and mantle. Our results strongly suggest that adherence rather than ingestion led to the accumulation of microplastics in those organs which are not involved in ingestion process. To our best knowledge, it is the first time to propose that adherence is a novel way for animals to uptake microplastics beyond ingestion. This new finding makes us rethink about the bioavailability, accumulation and toxicity of microplastics to aquatic animals.
This study reports a microfluidic chip-based wearable colorimetric sensor for detecting sweat glucose. The device consisted of five microfluidic channels branching out from the center and connected ...to the detection microchambers. The microchannels could route the sweat excreted from the epidermis to the microchambers, and each of them was integrated with a check valve to avoid the risk of the backflow of the chemical reagents from the microchamber. The microchambers contained the pre-embedded glucose oxidase (GOD)–peroxidase–o-dianisidine reagents for sensing the glucose in sweat. It was found that the color change caused by the enzymatic oxidation of o-dianisidine could show a more sensitive response to the glucose than that of the conventional GOD–peroxidase–KI system. This sensor could perform five parallel detections at one time. The obtained linear range for sweat glucose was 0.1–0.5 mM with a limit of detection of 0.03 mM. The sensor was also used to detect the glucose in sweat samples from a group of subjects engaged in both fasting and postprandial trials. The results showed that our wearable colorimetric sensor can reveal the subtle differences existing in the sweat glucose concentration after the fasting and the oral glucose uptake.
We consider the problem of inferring what happened to a person in a social task from momentary facial reactions. To approach this, we introduce several innovations. First, rather than predicting what ...(observers think) someone feels, we predict objective features of the event that immediately preceded the facial reactions. Second, we draw on appraisal theory, a key psychological theory of emotion, to characterize features of this immediately-preceded event. Specifically, we explore if facial expressions reveal if the event is expected, goal-congruent, and norm-compatible. Finally, we argue that emotional expressivity serves as a better feature for characterizing momentary expressions than traditional facial features. Specifically, we use supervised machine learning to predict third-party judgments of emotional expressivity with high accuracy, and show this model improves inferences about the nature of the event that preceded an emotional reaction. Contrary to common sense, "genuine smiles" failed to predict if an event advanced a person's goals. Rather, expressions best revealed if an event violated expectations. We discussed the implications of these findings for the interpretation of facial displays and potential limitations that could impact the generality of these findings.
Microplastic has been confirmed as an emerging pollutant in marine environments. One of the primary environmental risks of microplastics is their bioavailability for aquatic organisms. Bivalves are ...of particular interest because their extensive filter-feeding activity exposes them directly to microplastics present in the water column. In the present study, we investigated microplastic pollution in mussels (Mytilus edulis) from 22 sites along 12,400 mile coastlines of China in 2015. The number of total microplastics varied from 0.9 to 4.6 items/g and from 1.5 to 7.6 items/individual. M. edulis contained more microplastics (2.7 items/g) in wild groups than that (1.6 items/g) in farmed groups. The abundance of microplastics was 3.3 items/g in mussels from the areas with intensive human activities and significantly higher than that (1.6 items/g) with less human activities. The most common microplastics were fibers, followed by fragments. The proportion of microplastics less than 250 μm in size arranged from 17% to 79% of the total microplastics. Diatom was distinguished from microplastics in mussels for the first time using Scanning Electron Microscope. Our results suggested that the numbers of microplastic kept within a relatively narrow range in mussels and were closely related to the contamination of the environments. We proposed that mussels could be used as a potential bioindicator of microplastic pollution of the coastal environment.
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•Microplastics varied from 0.9 to 4.6 items/g in Mytilus edulis.•M. edulis contained more microplastics in wild groups than farmed groups.•The most common microplastics were fibers.•Diatom was distinguished from microplastics in mussels.•Mussels could be used as a potential bioindicator of microplastic.
Microplastics varied from 0.9 to 4.6 items/g in wild and farmed Mytilus edulis from 22 sites along the coastal waters of China.
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