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Heavy metal pollutants in sediment greatly impact the estuarine environment and ecosystems, increasingly influenced by anthropogenic perturbations. Here, we examined the surface sediments of the Modaomen estuary in 2003, 2015, and 2021 to understand how human-induced changes influence the fate of heavy metals in the estuary's sediments. The potential ecological risk index (RI) suggests Cd should be the priority pollutant for environmental pollution control due to its high toxicity coefficient. In each sampling period, two main sources were identified through normalized heavy metals and PCA-MLR: natural and mixed anthropogenic sources (agricultural, industrial, and traffic activities), reflecting an increase in heavy metals pollution, later mitigated by successful environmental protection measures. Moreover, anthropogenic activities have not only impacted the sources discharge of heavy metals but have also influenced their spatial and temporal distribution through factors such as land reclamation, leading to sediment coarsening and reduced heavy metal content in specific areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

How to quickly and safely identify blood species has always been an urgent problem for scientists. Smear test method has the risk of blood contamination, and the blood itself may carry some unknown viruses or pathogens, which will bring health risks to the testing personnel. Therefore, in order to meet the urgent needs of rapid and safe detection of blood, a technology which can detect dynamic confocal Raman spectroscopy of flowing blood in bionic blood vessel was proposed. The blood, which was sealed in the bionic blood vessel, flowed through the focus gaze area of laser by the microfluidic pump, to detect the dynamic blood Raman spectrum. Human blood and cattle blood were selected as experimental objects, and the experiments were carried out under the same parameters. Combined with PCA-LDA (principal component analysis and linear discriminate analysis) classification model, the predictive classification of the two species without error recognition was realized. The hidden weak Raman signals were mined by derivative spectra, and the fundamental differences of Raman spectra of two species were compared. Then the biochemical information that caused the differences was also analyzed. The results show the method can meet the detection requirements of sealed blood, and the Raman spectra of flowing blood is more representative than those of static blood., Competing Interests: Declaration of Competing Interest There are no conflicts to declare., (Copyright © 2021. Published by Elsevier B.V.)

Many rivers are facing human-induced system regime shifts that have great environmental, ecological and social implications, necessitating an increasing need to quantify the human influence on sediment properties and their impacts on the source-to-sink system of marginal seas. The Huanghe and Changjiang Rivers have experienced a dramatic reduction in sediment flux in recent decades, typifying the human influence on sediment properties of global large rivers. Sediment samples from the two rivers were analyzed to obtain grain size, magnetic and geochemical data. The results show a large difference in sediment properties between pre- and post-dam periods. We applied a discrepancy factor to re-examine the magnetic and geochemical tracers that were previously used in the two rivers. The discrepancy factors of most magnetic and geochemical tracers in the mud-sized sediments of the two rivers increased by an average of about 109% after dam construction. This suggests that human-induced changes in sediment properties have greatly improved the discriminatory ability between the sediments from the two rivers. The results also raise the uncertainty of using previous tracers to distinguish between sediments from the two rivers after damming. Furthermore, significant changes in sediment properties that happened in a relatively short time may provide future geological time markers for sedimentary records with a temporal resolution of 10 0 -10 1  years. For marine environments, an approach for identifying sediment sources based on multiple independent optimum tracers is also proposed, with composite magnetic (SIRM vs. HIRM) and geochemical (Na 2 O vs. Zn) tracers being considered. The results of this work can advance our knowledge of how human activities alter river systems, and identify a sustainable development model under system regime shifts for areas of high-intensity human activity., (Copyright © 2019 Elsevier B.V. All rights reserved.)

To study the fluvial interaction between Changjiang River and Poyang Lake, we analyze the observed changes of riverine flux of the mid-upstream of Changjiang River catchment, the five river systems of Poyang Lake and Poyang Lake basin. Inter-annual and seasonal variations of the water discharge and sediment exchange processes between Changjiang River and Poyang Lake are systematically explored to determine the influence of climate change as well as human impact (especially the Three Gorges Dam (TGD)). Results indicate that climate variation for the Changjiang catchment and Poyang Lake watershed is the main factor determining the changes of water exchanges between Changjiang River and Poyang Lake. However, human activities (including the emplacement of the TGD) accelerated this rate of change. Relative to previous years (1956-1989), the water discharge outflow from Poyang Lake during the dry season towards the Changjiang catchment increased by 8.98 km(3)y(-1) during 2003-2010. Evidently, the water discharge flowing into Poyang Lake during late April-late May decreased. As a consequence, water storage of Poyang Lake significantly reduced during late April-late May, resulting in frequent spring droughts after 2003. The freshwater flux of Changjiang River towards Poyang Lake is less during the flood season as well, significantly lowering the magnitude and frequency of the backflow of the Changjiang River during 2003-2010. Human activities, especially the emplacement and operation of the TGD and sand mining at Poyang Lake impose a major impact on the variation of sediment exchange between Changjiang main river and Poyang Lake. On average, sediments from Changjiang River deposited in Poyang Lake before 2000. After 2000, Changjiang River no longer supplied sediment to Poyang Lake. As a consequence, the sediment load of Changjiang River entering the sea increasingly exists of sediments from Lake Poyang during 2003-2010. As a result, Poyang Lake converted from a depositional to an erosional system, with a gross sediment loss of 120.19 Mty(-1) during 2001-2010, including sand mining., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The stability of nitric acid oxidized carbon nanotubes (CNTs) and the precipitation of oxidized CNTs in water by salts were investigated. Stability investigation shows that during an aging time of 30 days, oxidized CNTs dispersion shows characteristic UV-vis absorbance peak of individual CNTs at 252 nm and CNTs concentration in the dispersion after 30d aging is 85% of the initial concentration. The precipitation value of salts were measured and the precipitation value follows the order of NaCl>KCl>1/2(MgCl(2))>1/2(CaCl(2))>1/3(FeCl(3))>1/3(AlCl(3)). The nature of anions investigated has little effect on precipitation values of salts.

In this study, a Lagrangian particle tracking model driven by hydrodynamic fields was used to investigate the changes of flushing properties in Xiaohai Lagoon resulting from natural evolution and influences of human activities. Comparisons of residence times between 1936 and 2001 indicate that the flushing efficiency of the lagoon has deteriorated greatly during the past seven decades. Over this period, the average residence time of the lagoon has increased from 45 to 71 days, an increase of 59%. The Lagrangian residual velocity has decreased from 1936 to 2001 in the large portions of the lagoon, and the spatial distribution pattern of the residual current has changed significantly. The well-developed horizontal circulations in 1936 disappeared. Instead, the horizontal Lagrangian residual velocity showed uniformly seaward motion with reduced velocity in 2001. Human activities have incurred great impacts on the deterioration of flushing efficiency. The reduction of river inflow imposed the most significant impact, causing an increase of average residence time by 33%. The land reclamation in the lagoon came as the second most significant factor, causing an increase of 15%. Closure of the North Opening had posed minor impact. The model results suggest that restoring the river inflow, as well as the dredging of the tidal channel and the inner lagoon, should be the top proprieties for future water quality management.