Marine fisheries and aquaculture can match growing demand for marine protein from an increasing population. However, the microplastics (MPs) in marine environments may pose a threat to human health ...through food chains by seafood consumption. The MPs have been found lodged in the digestive tracts and other tissues of various sea animals, nevertheless, little is known in regard to the accumulation of MPs in fish from major fish farms and mariculture areas, especially in non-digestive tissues of fishes. This study investigated the accumulation of MPs in six major wild fish species (including Thryssa kammalensis, Amblychaeturichthys hexanema, Odontamblyopus rubicundus, Cynoglossus semilaevis, Chaeturichthys stigmatias and Collichthys lucidus), both in digestive and non-digestive tissues, from an important fish farm and mariculture area, Haizhou Bay, China. All fishes had items that were identified as MPs. The highest abundance of MPs was 22.21±1.70items/individual or 11.19±1.28items/g in T. kammalensis, which is filter-feeding and usually inhabits in estuary. The lowest abundance of MPs was observed in C. semilaevis (13.54±2.09items/individual) and C. stigmatias (1.61±0.56items/g). The abundance of MPs exponentially increased with the decrease of MPs size. The MPs were dominated by fiber in shape, black or grey in colour and cellophane in composition. As to different tissues, the total number of MPs on skin (800) or in gills (746) was higher than that in gut (514). In terms of skin, the abundances of MPs in three species of scaleless fish with mucus (A. hexanema, C. stigmatias and O. rubicundus) were generally higher than other three fishes with scales (C. lucidus, C. semilaevis and T. kammalensis), implying the potential high risk of scaleless fish consumption for human health in Haizhou Bay. More in-depth studies need to focus on the scaleless fish through mucus adsorbing enormous MPs.
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•All fish in the Haizhou Bay had high microplastic (MP) abundance.•The total number of MPs in skin or in gills was higher than in gut.•The abundance of MPs exponentially increased with the decrease of MPs size.•Scaleless fish had higher MPs abundance in skin than scaly fish.
A simple method for measuring the thickness of metal films based on eddy-current sensors (ECSs) immune to distance variation is proposed. The slope of the lift-off curve (LOC) in the RL impedance ...plane is a good feature for characterizing target thickness independent of lift-off distance variation. A simple equivalent model was built to deal with the ECS problem, and the essential relationship between the slope of LOC (SLOC) and target properties was obtained. Full finite element analysis was conducted to analyze the relationship between SLOC feature and target thickness, and the results matched the modeling results very well. A sensor coil probe was then manufactured and used to measure the thickness of copper films with high performance, and the capability of this technique for online noncontact thickness measurement was verified. The basic characteristics and performances of this thickness measurement technique were tested and discussed. The SLOC feature for thickness measurement had significant advantages, such as simplicity, reliability, immunity to the lift-off effect (most important), high speed, simple signal processing, and negligible design limitation of the sensor probe. The results of this paper revealed that online thickness measurement systems could be developed for various advanced industrial applications.
•Sedimentary PAHs in Guan River Estuary were investigated for the first time.•PAH concentrations were low in comparison with other estuaries around the world.•PAH concentrations appeared to be ...negatively correlated with sediment grain size.•Sedimentary PAHs in GRE mainly originated from pyrolytic sources.•Sedimentary PAHs in GRE indicated low negative effects except FLO.
The contamination of surface sediments in Guan River Estuary, China, by polycyclic aromatic hydrocarbons (PAHs) has been fully investigated. Total concentrations of 21 PAHs ranged from 90 to 218ng/g with an average of 132.7ng/g, which is relatively low in comparison with other estuaries around the world. PAH concentrations appeared to be positively correlated with clay content and negatively correlated with sediment grain size. Source identification implied that the PAHs originated mainly from pyrolytic sources. However, source patterns may be continuously changed to a petrogenic origin due to the heavy ship traffic and continuous discharge of oily sewage in this area. The PAH levels were also compared with international Sediments Quality Guidelines and Sediments Quality Criteria, and the results indicated low negative effects for most individual PAHs. However, toxic effects related to FLO would occur occasionally in most locations in the estuary.
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•Drifting macroalgae showed a higher microplastics (MPs) abundance than attached form.•MPs abundance in drifting macroalgae increased along the drifting path.•MPs abundance in driting ...macroalgae was 2204 times higher than that in seawater.•Ulva prolifera has diverse mechanisms to trap microplastics.•U. prolifera has a high tolerance to microplastics.
Macroalgal blooms and marine microplastics (MPs), as global challenges for oceans, are both showing a rising trend. However, none is known regarding the interaction of these two important issues. The Yellow Sea suffers the world’s largest green tides and severe MPs pollution as well. Therefore, we tracked the trapping of MPs by drifting Ulva prolifera in the Yellow Sea during the green-tide period. The abundance of MPs in drifting U. prolifera was 595–3917 times higher than that in seawater and increased along the drifting path from south to north in the Yellow Sea. In addition, four mechanisms of trapping plastics (twining, attachment, embedment, and wrapping) on or in U. prolifera were unmasked, which explains why the plant has such strong capacity to trap MPs. Laboratory incubation experiments showed that MPs (0.025–25 mg L−1) did not affect relative growth rate, effective photochemical efficiency of photosystem II (PSII), or saturating irradiance of U. prolifera until reaching an extremely high concentration (100 mg L−1), indicating a high tolerance to MPs. Due to tremendous biomass and coverage of the green tide and increased frequency as well, the plastics trap in drifting macroalgae can alter the spatio-temporal distribution of MPs in the oceans.
Sea urchins serve as an essential niche for benthic ecosystems and are valuable seafood for humans. However, little is known about the microplastics (MPs) accumulation in sea urchins. Here, we ...investigated the abundances and characteristics of MPs in specific tissues of wild sea urchins for 12 sites across 2, 900 km of coastlines in northern China. Sea urchins from all sites were detected to have MPs, with a total detection rate of 89.52%. The MPs abundance in sea urchins from all sites ranged from 2.20 ± 1.50 to 10.04 ± 8.46 items/individual or 0.16 ± 0.09 to 2.25 ± 1.68 items/g wet weight. The samples from Dalian were found to have the highest value by individual, and samples from Lianyungang had the highest value by gram. Furthermore, MPs were found in different tissues of sea urchins, i.e., gut, coelomic fluid and gonads. The highest abundance of MPs was found in the gut of sea urchins, followed by coelomic fluid and gonads. The size of MPs ranged from 27 to 4742 μm, and the mean size found in gut was bigger than coelomic fluid and gonads. More interestingly, the MPs abundance increased with the decrease of anus size, shell diameter and gonad index (the wet weight ratio of gonad to total soft tissues). The MPs were dominated by fiber in shape, blue-green in colour and cellophane in composition. The high MPs abundance in sea urchins indicates the potential risks to human as they are consumed in many parts of the world, particularly in Asia and Europe.
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•A very high detection rate of MPs was found in wild sea urchins in northern China•Apart from gut, coelomic fluid and gonads could also accumulate MPs.•The mean size of MPs in gut was bigger than coelomic fluid and gonads.•MPs abundance increased with the decrease of anus size and shell diameter.•MPs abundance was negatively related to gonad index.
This paper proposes a high-speed measurement system for the thickness of metal films based on the eddy-current method. Theoretical derivation shows the effects of film thickness on the impedance of ...the sensor coil. In a voltage division circuit, the thickness information is converted to the phase difference of two measured signals. The tangent value of the phase difference is proportional to thickness h, which is a result that has been verified theoretically and experimentally. The prototype used in this paper can cover a measurement range of 10 μm-0.5 mm for copper films, and can achieve a high measurement speed (up to excitation frequency) without a complex demodulation circuit. The measurement error caused by the temperature variation is roughly -0.2%/°C. The influence of external magnetic field on the prototype is also tested. The entire sensor size can be easily controlled in 50 × 50 × 30 mm 3 as a handheld device. The instrument can meet many industrial requirements for both online measurement and postinspection.
•An existing historic building influenced by nearby shield construction in loess stratum is analyzed.•Field monitoring and numerical simulation are carried out on the entire construction ...process.•Treatment effect of the pre-reinforcement measures is analyzed.•Settlement-time curves of the historic building and laws of ground settlement slot are obtained.
The influence of metro shield construction in congested urban areas on nearby buildings is of great concern in practice. In this study, 3D-FEM model, validated through comparison with field monitoring results were used to investigate the influence of Xi’an Metro Line 4 excavation on existing city wall of the Ming Dynasty at Heping Gate in loess ground. The research results were found to be in good agreement with field measurement results. Furthermore, the results indicated that because of pre-reinforcement by sleeve valve pipe grouting and supporting by I-shaped steel at openings, the surface settlement within the foundation area on the city wall is reduced by 4 mm compared with that without the reinforcement, and the settlement of the city wall structure is reduced by approximately 2.2 mm, which prevents excessive local heave of the city wall foundation and out-of-limit of inclination. Additionally, the settlement-time curves of the city wall structure and change laws of surface settlement slot were also obtained. This study provides a valid reference value for protecting historical buildings adjacent shield construction in similar loess areas.
SMA is an inherited disease that leads to loss of motor function and ambulation and a reduced life expectancy. We have been working to develop orally administrated, systemically distributed small ...molecules to increase levels of functional SMN protein. Compound 2 was the first SMN2 splicing modifier tested in clinical trials in healthy volunteers and SMA patients. It was safe and well tolerated and increased SMN protein levels up to 2-fold in patients. Nevertheless, its development was stopped as a precautionary measure because retinal toxicity was observed in cynomolgus monkeys after chronic daily oral dosing (39 weeks) at exposures in excess of those investigated in patients. Herein, we describe the discovery of 1 (risdiplam, RG7916, RO7034067) that focused on thorough pharmacology, DMPK and safety characterization and optimization. This compound is undergoing pivotal clinical trials and is a promising medicine for the treatment of patients in all ages and stages with SMA.
The nonlinear dynamic behavior of ballooning yarn in the ring spinning system is investigated. An improved dynamic model of ballooning yarn with axial conveying speed is established. Based on ...Hamilton’s law of variation principle, the three-dimensional dynamic differential equations are derived. Then, the shooting method is employed to solve the two-point boundary value problem of ordinary differential equations. The numerical results of balloon profiles and distribution tension curves of ballooning yarns are discussed. The numerical results imply that with the increase of Ω, the yarn conveying speed increases, the minimum tension at the guide eye increases, and the helical loops of the balloon profile decrease. It is also found that as Ω increases, the spatial area of the guide eye tension
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0
that forms the dynamic balloon decreases. When the yarn conveying speed is medium or high, under different tensions at the guide eye, the yarn tensions along the height direction of the balloon change in the same trend, and the tensions of the ballooning yarn at the same height are very close. In addition, with the increase of Ω, the distribution tension of the ballooning yarn changes significantly under the same guide eye tension.
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