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Precipitation can lead to significant leaching of heavy metals from abandoned tailings，resulting in a decline in the quality of the surrounding environment. This study aimed to simulate and quantify the migration patterns and fate of heavy metals in tailings caused by precipitation in various environmental media (tailings, air, water, soil, and sediments) using leaching tests, source apportionment, and a fugacity model. Results revealed that the average contents of Cd, Cu, As, Pb, Zn, and Cr in the un-weathered tailings were 3.43, 495.56, 160.70, 138.94, 536.57, and 69.52 mg/kg, respectively. The ecological risk factors in the tailings as well as in sediments and soils, were in the following order: Cd >Cu >As >Pb >Zn >Cr. A fugacity model based on the mass-balance methods was established, achieving a good agreement between simulation and measured values. The total amounts of Cd, Cu, As, Pb, and Zn leached from abandoned tailings over the 30-year evaluation period were estimated to be 1.09, 62.44, 0.16, 0.94, and 102.12 t, respectively. Soil and sediments are important reservoirs for heavy metals. The sum of the As, Cd, Cu, Pb, and Zn storage capacities in the soil and sediment accounted for 77.28%, 75.63%, 73.94%, 69.39%, and 57.80% of the total storage capacity, respectively. This study could provide the means for the establishment of a targeted pollution control plan, a guide for restoration projects, and will aid in controlling pollution risk and improving the surrounding environment. • Heavy metal (HMs) leaching by precipitation degrades water, soil, and sediments. • A fugacity model was developed to simulate HMs migration in different environments. • HMs properties and environmental parameters determine HMs distribution and transport. • Our results can help establish a targeted pollution control plan. [ABSTRACT FROM AUTHOR]

The effects of chitosan-epigallocatechin gallate (EGCG) coating on sensory properties and retention of volatile flavor compounds (VFCs) in chilled bighead carp fillets were examined. Scores of odor and overall acceptability indicated that as compared with the control group and group coated with chitosan, chitosan-EGCG coating had the best retention effect on the flavor and quality of the fillets. Twenty-eight VFCs, mainly alcohols, ketones, and aldehydes, were identified from the fillets by GC-IMS analysis. Fillets in the control group showed unique characteristic VFCs distribution at different storage stages: 2-butanone in the early stage; 3-methylbutanal and 2-methylbutanal in the middle stage; and heptanal and 1-octen-3-ol in the final stage. However, the VFCs signals in chitosan-EGCG coated fillets were delayed along with the sharply suppressed intensities of off-odor VFCs such as 1-octen-3-ol, indicating that chitosan-EGCG coating was able to inhibit the formation of off-odors effectively. Principal component analysis and clustering analysis distinguished samples with different storage times and treatments. This study indicated that chitosan-EGCG coating could maintain the flavor quality of bighead carp fillets, and the characteristic VFCs of different storage stages could be considered as signal indicators to identify fish freshness. [Display omitted] • Chitosan-EGCG coating was conducive to the retention of natural flavor of fillets. • Chitosan-EGCG coating significantly inhibited the formation of off-flavors. • The fillets had unique characteristic VFCs distribution at different storage stages. • Chitosan-EGCG coating was suggested as the preservative for bighead carp fillets. [ABSTRACT FROM AUTHOR]

• Verify that turbulence noise in water pipelines can be used for passive imaging. • Extract time-domain Green's functions from correlation-based noise functions. • Propose passive methods to extract wave speed and detect faults in the pipelines. Ambient noise generated by flowing water turbulence is harnessed as a signal source for imaging key parameters and fault detection in water pipelines. This approach is important because it can aid in the estimation of wave speed or detection of water pipeline defects such as blockages and leakages. More importantly it overcomes the challenging problem of generating a signal source of sufficient power to provide the necessary signal-to-noise ratios for conventional water pipeline imaging and fault detection techniques. In this paper, the expressions of the auto- and cross-correlation functions of the ambient noise between sensors are derived using wave theory. It is shown that the time-domain Green's functions can be extracted from the correlation functions. Experimental and numerical examples are provided for water pipelines to demonstrate that wave speed can be estimated from the time-domain Green's functions. A method for extending the technique, by using straightforward but accurate approximations of the correlation functions, to detect the presence of defects in the profile of the water pipeline is also proposed. [ABSTRACT FROM AUTHOR]

Constructing nanoscale coordination polymers (CPs) with different micro- or nanoscale morphologies and sizes is crucial for the functionalization of CPs-based heterogeneous catalysts. Herein, surfactant polyvinylpyrrolidone (PVP), surface-supported frameworks (filter paper or Ni foam), and Co-based CPs (1), [Co 2 (pdpa)(py) 4 (H 2 O)] n (H 4 pdpa ​= ​5,5'-(pentane-1,2-diyl)-bis(oxy)diisophthalic; py ​= ​pyridine)) were employed to develop highly ordered micro- or nanoscale CPs, achieving microscale 1a (without surface-supported framework) and nanoscale 1b-c (filter paper and Ni foam as surface-supported frameworks for 1b and 1c , respectively). Furthermore, the catalytic performance of nanoscale 1c with spheric particles for the tandem conversion reactions of aromatic nitriles and diamines into imidazoline or tetrahydropyrimidine frameworks was much more prominent than that of large scale 1 , microscale 1a , and nanoscale 1b because of the easily accessible catalytic active sites in the nanoscale spheric particles, which offered a functionalizable platform for the tandem reactions by minimizing the diffusion distance but did little for their activity. By introducing surfactant and surface-supported frameworks, different morphologies and particle sizes of Co-based CPs with micro- or nanoscale 1a-c were constructed and were used as efficient heterogeneous catalysts to execute tandem conversion reactions. [Display omitted] • A new Co-based CPs was constructed under solvothermal conditions. • Co-based CPs with different morphologies and particle sizes were obtained. • The catalytic performance of all the prepared particles for tandem reactions was conducted. [ABSTRACT FROM AUTHOR]

Introducing charged terminal groups to polymers that graft nanoparticles enable Coulombic control over their assembly by tuning the pH and salinity of their aqueous suspensions. Gold nanoparticles (AuNPs) are grafted with poly (ethylene glycol) (PEG) terminated with ▪ (charge-neutral), ▪ (negatively charged) or ▪ groups (positively charged), and characterized with dynamic light scattering, ζ -potential, and thermal gravimetric analysis. Liquid surface X-ray reflectivity (XR) and grazing incidence small-angle X-ray scattering (GISAXS) are used to determine the density profile and in-plane structure of the AuNPs assembly at the aqueous surface. Assembly of PEG-AuNPs at the liquid/vapor interface is tunable by adjusting pH or salinity for COOH but less for ▪ terminals. The distinct assembly behaviors are attributed to the overall charge of PEG-AuNPs as well as PEG conformation. COOH-PEG corona is more compact than those of the other terminal groups, leading to a crystalline structure with a smaller superlattice. The net charge per particle depends not only on the PEG terminal groups but also on the cation sequestration of PEG and the intrinsic negative charge of the AuNP surface. [1] The closeness to overall charge neutrality, and hydrogen bonding in play, brought by ▪-PEG, drive ▪-PEG-AuNPs to assembly and crystallinity without additives to the suspensions. [ABSTRACT FROM AUTHOR]

Spoilage bacteria, which ubiquitously contribute to food spoilage, pose a global public health risk. In this study, we developed a centrifugal microfluidic chip integrating fluorogenic loop-mediated isothermal amplification (LAMP) to detect six important spoilage bacteria: Bacillus cereus , Clostridium botulinum , Photobacterium phosphoreum , Pseudomonas putida , Streptococcus agalactiae , and Shewanella putrefaciens. The LAMP reaction components were pre-mixed (primers pre-embedded in each reaction chamber of the chip) and evenly pipetted into the two inlet holes, enabling the simultaneous analysis of six genetic targets from a single sample. This facilitates the automated detection of up to four samples simultaneously using a single chip. The LAMP reactions were conducted in a 5-μL volume at 65 °C for 60 min, achieving limits of detection ranging from 10−1 to 10−2 pg/μL of bacterial genomic DNA. Almost all coefficients of variation for time-to-positive values consistently remained under 10% when genomic DNA was used at concentrations within the limits of detection for the six bacteria. This demonstrated excellent reproducibility across replicates. The clinical sensitivity and specificity for field sample detection were 93.3% and 97.5%, respectively. This method offers ease of operation, rapid analysis, and minimal reagent usage and has great potential for the on-site detection of multiple spoilage bacteria. • We develop a fluorogenic LAMP assay integrated on a centrifugal microfluidic chip. • This assay enables parallel analysis of six genetic markers through two pipetting operations. • This assay detects six spoilage bacteria within 60 min with high specificity and sensitivity. • This assay is easy to operate and suitable for routine detection of multiple spoilage bacteria. [ABSTRACT FROM AUTHOR]

Soil nitrogen (N) is an essential nutrient for tree growth, and excessive N is a source of pollution. This paper aims to define the effects of plant diversity and forest structure on various aspects of soil N cycling. Herein, we collected soils from 720 plots to measure total N content (TN), alkali-hydrolyzed N (AN), nitrate N (NO 3 −-N), ammonium N (NH 4 +-N) in a 7.2 ha experimental forest in northeast China. Four plant diversity indices, seven structural metrics, four soil properties, and in situ N 2 O efflux were also measured. We found that: 1) high tree diversity had 1.3–1.4-fold NO 3 −-N, 1.1-fold NH 4 +-N, and 1.5–1.8-fold N 2 O efflux (p < 0.05). 2) Tree growth decreased soil TN, AN, and NO 3 −-N by more than 13%, and tree mixing and un-uniform distribution increased TN, AN, and NH 4 +-N by 11–22%. 3) Soil organic carbon (SOC) explained 34.3% of the N variations, followed by soil water content (1.5%), tree diameter (1.5%) and pH (1%), and soil bulk density (0.5%). SOC had the most robust linear relations to TN (R2 = 0.59) and AN (R2 = 0.5). 4) The partial least squares path model revealed that the tree diversity directly increased NO 3 −-N, NH 4 +-N, and N 2 O efflux, and they were strengthened indirectly from soil properties by 1%–4%. The effects of tree size-density (−0.24) and spatial structure (0.16) were mainly achieved via their soil interaction and thus indirectly decreased NH 4 +-N, AN, and TN. Overall, high tree diversity forests improved soil N availability and N 2 O efflux, and un-uniform spatial tree assemblages could partially balance the soil N consumed by tree growth. Our data support soil N management in high northern hemisphere temperate forests from tree diversity and forest structural regulations. We found that plant diversity directly increased NO 3 −-N, NH 4 +-N and N 2 O efflux in soil. Soil physicochemical properties played a strong mediating role in the effect of forest structure on soil nitrogen availability. Tree size-density indirectly decreased the soil N availability via soil physicochemical properties, but the forest spatial distribution (mixing and un-uniform distribution) balanced part of the negative effect on soil N. Our results provide new insights into forest management and deepen our understanding of plant diversity and forest structure on the N cycle. [Display omitted] • Four soil N parameters from 720 soils, and 18054 trees were measured in 720 plots in NE China. • High tree diversity accompanied with 1.3–1.4-fold nitrate-N, 1.1-fold ammonium-N, and 1.5–1.8-fold N 2 O efflux. • The best predictors for soil N were soil organic carbon, water content, and diameter at breast height. • Tree growth decreased soil N availability, and tree mixing and distribution patterns balance part of these declines. • Tree size-density and spatial distribution contrarily affect soil N availability via soil properties. [ABSTRACT FROM AUTHOR]

Accurate information on urban forests of tree sizes, health state, community structures, and spatial distribution is still limited in African cities. Using a Google Street View (GSV)-based tree-size measuring method developed by our team, this paper aims to evaluate street trees of four African metropolitan cities using GSV data. The study compiled a large dataset with 46,016 street trees in 3454 sites in Kampala, Nairobi, Bloemfontein, and Johannesburg. The data including tree size (diameter at breast height, DBH; tree height, TH; underbranch height, UBH; canopy size), tree floristic composition (apical dominance types, broadleaf-conifer-palm leaf, flowering or not), tree health (leaf color, diebacks, dead tree, and bracket-supporting percent), streetside development (lane number, roadside shops, parking vehicle, and pedestrian density), and geolocation (latitude, longitude). These data can be spatially visualized with the help of ArcGIS, and the large dataset favors reliable maps from the street-view level. Data statistics showed that four cities were dominated by broad-leaved, apical dominance, and flowering trees, with a low level of unhealthy leaves and a tiny percentage of dead. The arbor-shrubs-herb structure vegetation dominated all four cities. Kampala had the most slender trees (DBH = 23 cm, TH = 8.4 m), while Nairobi and Johannesburg had the thickest trees (DBH = 38 cm, TH = 8.5–8.6 m). Bare land rates were lowest at 23% in Bloemfontein and highest at 33% in Nairobi. Principal analysis and Pearson correlations showed that these tree variations were closely associated with street development and local land use configuration. By comparing the urban tree data in other regions of the world, we found that the trees in African cities are generally giant but have a lower density (the trees within a 100-m street segment). Our findings emphasized that GSV data is feasible enough for urban forest monitoring in Africa, and the database is helpful for urban landscape planning and management. • Google Street View pictures were used to evaluate urban forest in Africa. • Street forest characteristics can be quantified at both site and city levels. • Data from >3000 sites, >46 thousand trees enabled ArcGIS-based spatial mapping. • This method is a supplement of remote sensing and field measurement methods. • The data fill the data gap in Africa, facilitating urban planning and management. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of 11-aminoalkoxy benzophenanthridine derivatives were synthesized. • 14 shows the most TDP1 inhibition. • 14 induces the cellular TDP1cc formation in MCF-7 cells. • 14 shows synergistic effect with topotecan in MCF-7, A549, H460 and HepG2 cells. • Benzophenanthridine scaffold is a chemotype for the discovery of TDP1 inhibitors. Tyrosyl-DNA phosphodiesterase 1 (TDP1) is an enzyme that repairs DNA lesions caused by the trapping of DNA topoisomerase IB (TOP1)-DNA break-associated crosslinks. TDP1 inhibitors have synergistic effect with TOP1 inhibitors in cancer cells and can overcome cancer cell resistance to TOP1 inhibitors. Here, we report the synthesis of 11-aminoalkoxy substituted benzophenanthridine derivatives as selective TDP1 inhibitors and show that six compounds 14 , 16, 18 , 20 , 25 and 27 exhibit high TDP1 inhibition potency. The most potent TDP1 inhibitor 14 (IC 50 = 1.7 ± 0.24 μM) induces cellular TDP1cc formation and shows synergistic effect with topotecan in four human cancer cell lines MCF-7, A549, H460 and HepG2. [ABSTRACT FROM AUTHOR]

The effect of dipping frozen bighead carp fillets in tea polyphenols (TPs) on biogenic amines (BAs) and free amino acids (FAAs) was examined to investigate the inhibition of BA formation in fish during frozen storage. The TP dipping treatment effectively retarded the formation of BAs and the loss of FAAs in the bighead carp fillets during frozen storage. In particular, the BA content in the TP-treated samples was 30%–46% lower than that of the control samples. Additionally, the pH and total volatile basic nitrogen (TVB-N) value in the TP treated samples decreased by 3%–5% and 14%–22%, respectively. Lower storage temperatures contributed to reducing the above attribute values. Redundancy analysis (RDA) indicated positive correlations between histidine and histamine and between phenylalanine and 2-phenylethylamine. However, there were negative correlations between other BAs, such as cadaverine, tyramine, spermidine and spermine, and their precursor FAAs. This study provides updated information on the associations between BAs and FAAs in fish during frozen storage, and it introduced an advanced protocol for improving the freshness and safety of aquatic products during frozen storage. [Display omitted] • Tea polyphenols could effectively reduce the formation of biogenic amines. • Correlations between biogenic amines and free amino acids were revealed. • Histidine-abundant fish contributed to more histamine accumulation during storage. • Dipping in a tea polyphenols solution improved fish safety. [ABSTRACT FROM AUTHOR]