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Integrated calculations of pollution load and water environmental capacity (WEC) are essential for effective water quality management. However, few studies have focused on the dynamic WEC and pollution load in a nonpoint source pollution (NPS)-dominant temperate monsoon watershed under changing rainfall conditions. In this study, a new framework based on the watershed model and WEC calculation with stochastic rainfall input (SR-WEC), was proposed to reveal the dynamic WEC and pollution load under changing rainfall conditions. Stochastic rainfall series was generated by a first-order Markov chain and gamma distribution, and further input into the Soil and Water Assessment Tool (SWAT) to explore the dynamic response of water quality to rainfall. The framework was applied to the Daning River watershed, Three Georges Reservoir Region, China. The results suggested that compared with the new SR-WEC, the traditional return period method with limited observed rainfall input would result in an underestimation of ideal WEC and NPS pollution load by 23% and 48% for TN and 48% and 51% for TP, respectively. Approximately 46% of the annual TN reduction and 51% of the annual TP reduction were concentrated from April to June in a relatively small area. The regression relationships between rainfall and the ideal WEC, pollution load and remnant WEC obtained by the SR-WEC were superior to those of the traditional method, with R 2 values increasing from 0.005-0.797 to 0.718-0.989. Specific threshold (120 mm/month for the study area) was observed for the effect of rainfall on water quality, beyond which the remnant WEC of organic N would change from decreasing to increasing. The new framework proposed identifies the key periods and areas with consideration of uncertainty of rainfall on water quality, and provides basis for NPS pollution management., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A novel genipin crosslinked calcium alginate/chitosan/polydopamine composite beads (g-Alg/CS/PDA) was synthesized for the removal of residual difenoconazole and nitenpyram during the clarification of apple juice. The composite beads with low potential health risks for all of the main materials were natural, green and biocompatible. Since g-Alg/CS/PDA can both clarify and adsorb, pesticide residues could be removed during the clarification of juice without additional steps. The g-Alg/CS/PDA beads were characterized, and the adsorption parameters, including the pesticide residue levels, adsorption time, pH, ionic strength, fructose concentration and adsorbent dose, were optimized. The adsorption data were fitted to the Freundlich isotherm model (R 2  = 0.9604, 0.9625) and the pseudo-second-order kinetic model (R 2  = 0.9993, 0.9999). The results indicated that the adsorption behavior of beads was heterogeneous. Moreover, the rate was controlled by several factors. The adsorption mechanism of two pesticides was also discussed. Hydrophobic and π-π conjugation interactions played a dominant role for the adsorption of difenoconazole, while hydrogen bonding and electrostatic interactions were the main factors for nitenpyram., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

At present, the contradiction between survival and ecology necessitates the integration of crop planting, chemical fertilizer application, and livestock and poultry breeding. Reasonably integrated crop-livestock systems (ICLSs) have become an important part of regional ecological and agricultural development. In this study, the relationship between manure nutrient demands for crops and manure nutrient supply from livestock is considered based on the balance of ICLSs in Jiangxi Province, China. The land carrying capacity index and potential of livestock breeding under uncoordinated systems are further discussed. The study also addresses water environmental risk due to surplus nutrients by integrating a traditional land carrying capacity framework and hydrological model. The results show that phosphorus absorption in land areas is the main limiting factor for the development of the livestock and poultry industries. In addition, manure nutrient demand exceeded supply in most districts, while the unbalanced regions with nutrient pollution are located in the upper and middle reaches of the Ganjiang basin. In addition, expanding the crop demand for manure or increasing the manure collection rate will help reduce environmental harm; however, attention should be paid to the risk of excessive manure returns. Additional livestock manure can be transferred to regions with developed crop planting systems. This study supports more harmonious and common ICLSs construction., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Alzheimer's disease (AD) is a chronic, progressive, and fatal neurodegenerative disorder that is characterized by memory failure, cognitive impairment, as well as behavioral and psychological manifestations. Drugs can only moderately manage, but not alleviate, clinical symptoms. Results, based on animal models, have demonstrated that cell therapy is a promising strategy for treating neurodegenerative disorders. The homing effect of mesenchymal stem cells (MSCs) replaces damaged cells, while some scholars believe that the paracrine effects play a crucial role in treating diseases. In fact, these cells have rich sources, exhibit high proliferation rates, low tumorigenicity, and immunogenicity, and have no ethical concerns. Consequently, MSCs have been used across various disease aspects, such as regulating immunity, nourishing nerves, and promoting regeneration. Deterioration of public health status have exposed both Alzheimer's patients and researchers to various difficulties during epidemics. In this review, we discuss the advances and challenges in the application of mesenchymal stem cell therapy for treatment of Alzheimer's disease., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The classic export coefficient model has been questioned due to its fixed coefficient, especially for those large-scale watersheds where great temporal-spatial heterogeneity exists. In this paper, a dynamic export coefficient model (DECM) was proposed for simulating non-point source (NPS) pollution by incorporating the impacts of factors on export coefficients. The relationships between rainfall, slope, soil, land use, other factors and export coefficients were constructed at relatively smaller catchment based on the information of mechanistic-based model, while these dynamic export coefficients were then extended to the large ungauged basins. This new model was tested in the Three Gorges Reservoir Region (TGRR), China. The results indicated the new method improved the accuracy of large-scale NPS prediction as well as reducing the computation burden. The rainfall temporal variability was identified as the major factor influencing the variability of flow and NPS pollution with the coefficient of variation being 0.1678 and 0.2046, respectively. Using the new method, the Long watershed, the Jialing watershed, the Quxi watershed, the Xiangxi watershed and the main stream in the TGRR were identified as those sensitive regions under the changing environment. The DECM could be extended to other large scale to quantify the NPS pollution, especially data-poor watersheds., 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 © 2020 Elsevier B.V. All rights reserved.)

Optimizing long-term best management practices (BMPs) is of vital importance for water quality management, especially for nonpoint source (NPS) pollution. However, changes in the efficiency of BMPs over time have not been incorporated and a proper method for determining long-term BMP configuration strategies is still lacking. In this study, the long-term BMP optimization method (LBMP-OM) was developed for recommending the BMP maintenance-replacement strategies and optimizing the BMP configuration. This new method was then tested in the Daning Watershed, Three Gorges Reservoir Region, China. Based on the results, a 1-year maintenance period and a 3-year replacement period was recommended for a filter strip by considering a changing BMP effectiveness rather than a constant effectiveness and by discussing the rationality of experts' suggestions for maintenance and replacement strategies regarding the regulation of NPS pollution. At the watershed scale, the total cost dropped by 57.36% by introducing the LBMP-OM method compare to the original method. This new method extended the long-term management and configuration of BMPs., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and company that could be construed as influencing the position presented in, or the review of this manuscript., (Copyright © 2020 Elsevier B.V. All rights reserved.)

As one typical land use change, the mechanism of returning farmland to forests (RFF) on nonpoint source pollution (NPS) is not clear, especially at multiple spatial scales. In this study, by using the Soil and Water Assessment Tool (SWAT), the changes in several flow-related and NPS-related indicators across several nested catchments were quantified and compared in the Three Gorges Reservoir Region, China. The results indicated that RFF could reduce the total flow and total phosphorus (TP), which are higher in the dry season (41% and 79%, respectively) than in the wet season (21% and 47%, respectively) at the watershed with a total area of 2423.74 km 2 . In comparison, RFF has a larger impact on the baseflow index during the wet season (367.02%) than during the dry season (166.54%). The results also indicated that a spatial scaling effect did exist, while the reduction in TP increased from 24.57% to 48.46% as the drainage area increased from 65.92 km 2 to 2104.35 km 2 . Specific thresholds of RFF efficiency were also observed (approximately 2000 km 2 for the study area). It is suggested that other source control measures could supplement RFF by stabilizing the efficiency of RFF across different spatial scales. The results of this study could provide valuable suggestions for land use development and water quality protection, especially for large, complex watersheds., (Copyright © 2019 Elsevier Ltd. All rights reserved.)