Soil heavy metal contamination is a major environmental concern, and the ecological risk associated with heavy metals is increasing. In this paper, we investigated heavy metal contamination near ...Dabaoshan Mine by: using sequential indicator simulation to delineate the spatial patterns of soil data; fitting multiple linear regression models for heavy metal uptake by crops; interpreting land uses from remote sensing images and integrating the spatial patterns, uptake models and land uses into a dose–response model for human health risks from heavy metals. The areas with elevated soil heavy metal concentrations are mainly located at the Dabaoshan Mine site and in the watershed basins of the Hengshi, Tielong and Chuandu rivers. The average concentrations of Cu, Zn, Cd and Pb in soil in the study area are all above the natural soil background levels, but Cd is the major contributor to human health risk in the area. Areas of low soil pH are also found throughout the watershed basins of the Hengshi, Tielong and Chuandu rivers. Of the different land use types in the study area, agricultural and residential land uses have the highest human health risk because ingestion is the dominant exposure pathway for heavy metals. The spatial patterns of the heavy metal concentrations and soil pH indicate that the areas with the highest human health risk regions do not directly coincide with the areas of highest heavy metal concentrations, but do coincide with the areas of lower soil pH. The contamination with high concentrations of heavy metals provides the risk source, but the combination of high heavy metal concentrations, low pH and agricultural or residential land use is required for human health risks to be present. The spatial pattern of the hazard quotients indicates that Cd is the most important pollutant contributing to the human health risk.
►The distribution of Cu, Zn, Cd, Pb and pH in soil were analyzed near Dabaoshan Mine. ►Heavy metal uptake models in crops were established using multiple regression method. ►Land use was extracted from a remote sensing image. ►Cadmium was the major heavy metal pollutant near Dabaoshan Mine. ►Agricultural and residential land had greatest health risks due to Cd contamination.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Understanding Cd-resistant bacterial cadmium (Cd) resistance systems is crucial for improving microremediation in Cd-contaminated environments. However, these mechanisms are not fully understood in ...plant-associated bacteria. In the present study, we investigated the mechanisms underlying Cd sequestration and resistance in the strain AN-B15. These results showed that extracellular Cd sequestration by complexation in strain AN-B15 was primarily responsible for the removal of Cd from the solution. Transcriptome analyses have shown that the mechanisms of Cd resistance at the transcriptional level involve collaborative processes involving multiple metabolic pathways. The AN-B15 strain upregulated the expression of genes related to exopolymeric substance synthesis, metal transport, Fe-S cluster biogenesis, iron recruitment, reactive oxygen species oxidative stress defense, and DNA and protein repair to resist Cd-induced stress. Furthermore, inoculation with AN-B15 alleviated Cd-induced toxicity and reduced Cd uptake in the shoots of wheat seedlings, indicating its potential for remediation. Overall, the results improve our understanding of the mechanisms involved in Cd resistance in bacteria and thus have important implications for improving microremediation.
Display omitted
•Strain AN-B15 effectively sequestered Cd mainly by complexation.•Formation of CdS nanoparticles partially explains Cd sequestration by AN-B15.•Cd resistance in strain AN-B15 is a collaborative process involving multiple metabolic systems at the transcriptional level.•AN-B15 strain reduced Cd accumulation and phytotoxicity in plants.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Reactive oxygen species (ROS) are pivotal signaling molecules that control a variety of physiological functions. As a member of the ROS family, peroxynitrite (ONOO
) possesses strong oxidation and ...nitrification abilities. Abnormally elevated levels of ONOO
can lead to cellular oxidative stress, which may cause several diseases. In this work, based on the rhodamine fluorophore, we designed and synthesized a novel small-molecule fluorescent probe (
) for ONOO
. Upon reaction with ONOO
,
exhibited a significant fluorescence signal enhancement (approximately 34-fold). Moreover,
showed an excellent mitochondria-targeting capability. Confocal fluorescence imaging validated its ability to detect ONOO
changes in HeLa and RAW264.7 cells. Notably, we observed the ONOO
generation during the ferroptosis process by taking advantage of the probe.
displayed good biocompatibility, facile synthesis, and high selectivity, and may have potential applications in the study of ONOO
-associated diseases in biosystems.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Layer-number modulation in graphene has become a recent focus of research due to the superior degree of freedom that can be achieved in terms of magic-angle, wettability, superconductivity, and ...superlattices. However, the intrinsic transport of multilayer graphene is indistinguishable in atmospheric adsorbates and supporting environment, and its underlying charge transfer mechanism has not yet been thoroughly determined. In this study, a shift in the charge neutrality point of trilayer graphene (TLG) is demonstrated to be regulated by three governing factors: oxygen gas (O2), water molecules (H2O), and thermally activated electrons. Absorbed O2 induces a high work function in semimetallic TLG, while H2O is not an evident dopant but can strengthen binding against O2 desorption. A simplified model is developed to elucidate the competitive mechanism and charge transfer among these two dopants (O2, H2O) and thermal electrons, and the model is demonstrated by work function regulation and Bader charge transfer based on density functional theory calculations. This study provides a strategy to explore transport modulation of multilayer graphene in the fields of ballistic transport and low power consumption of graphene field-effect transistors.
The shift of charge neutrality point for trilayer graphene is demonstrated to be regulated by three governing factors: oxygen gas (O2), water molecular (H2O), and thermally activated electron originating from the underlying dielectric layer. Basing on DFT theoretical calculations, the doping competitive model is demonstrated to be rationality and supporting the experimental results. Display omitted
•Design two regulating strategies of work temperature and vacuum pressure, and distinguish oxygen gas (O2) and water molecular (H2O) contribution in a shift for the charge neutrality point of trilayer graphene.•Establish a competitive doping model, and reveal three dominating factors of O2, H2O, and thermally activated electron stemming from underlying SiO2 dielectric in competitive doping behavior.•DFT calculations demonstrate the rationalization of the competitive doping mechanism model.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Display omitted
•A ratiometric fluorescent probe for sensing Hg2+ based on new pyrido1,2-abenzimidazole fluorophore has been synthesized.•The probe exhibits highly sensitivity and selectivity toward ...Hg2+ (detection limit: 18.8nM).•The ratiometric fluorescent probe displays a remarkable emission shift (up to 204nm).•The probe shows low cytotoxicity and can be applied in cells.
A novel pyrido1,2-abenzimidazole-rhodamine ratiometric fluorescent probe TMUHg-3 for Hg2+ based on a fluorescence resonance energy transfer mechanism has been developed. In this system, the energy transfer efficiency is 87.3%. The probe can detect Hg2+ with a very low detection limit of 18.8nM, and very high selectivity toward Hg2+. Furthermore, it can be used for imaging Hg2+ in living cells.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
A novel fluorophore pyrido1,2-abenzimidazole was synthesized and used as a donor to construct FRET system. The probe shows a large Stokes shifts (190 nm), high selectivity, fast response (within ...2 min), and high sensitivity toward Cu2+ (detection limit 42 nM). A significant colour change from colourless to pink could be observed, enabling naked-eye detection of Cu2+. Furthermore, it could be used for imaging Cu2+ in living cells which demonstrated its value of practical applications in biological systems.
Display omitted
•A Cu2+ ratiometric fluorescent probe based on new pyrido1,2-abenzimidazole fluorescent dye has been synthesized.•The probe exhibits highly sensitivity and selectivity toward Cu2+ (detection limit: 42 nM).•The ratiometric fluorescent probe displays a remarkable emission shift (up to 190 nm).•The probe show low cytotoxicity and can be applied in cells.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Gravel-based subsurface-flow constructed wetlands (CWs) amended with a walnut shell (WS) substrate were established to treat synthetic acid mine drainage (AMD) in this study, and artificial domestic ...wastewater (DW) and plant litter broth (PLB) were supplemented to enhance the performance. The CW media rapidly reached adsorption saturation with respect to metals (except Fe and Cr) without an external carbon source, while the addition of DW and PLB stimulated sulfate reduction activity and achieved efficient biogenic metal removal, primarily by the formation of hydroxide and sulfide precipitates and concomitant co-precipitation. The WS-amended CWs performed notably better than the control systems, not only in sequestering more metals and rapidly establishing favourable environments for biogenic metal abatement but also in supporting better growth of plants and functional microbes. The external organic carbon input greatly shaped the bacterial community compositions in the CWs, with substantial increases in the proportions of core functional populations involved in AMD biotreatment. Cooperation among Cellulomonas, Propioniciclava and sulfate-reducing bacteria (SRB), dominated by Desulfobulbus and Desulfatirhabdium, was the primary biogenic mechanism of AMD remediation in the CWs. Cellulosic waste-amended CWs with DW and PLB addition offer a promising eco-technology for AMD remediation.
Display omitted
•Constructed wetlands amended with walnut shells performed better than those with gravel in AMD remediation.•Domestic wastewater and plant litter broth efficiently enhanced the treatment effectiveness.•Precipitation as hydroxides/oxides and sulfides was the dominant mechanism of metal removal.•External carbon increases the functional population abundances greatly.•Synergy among Cellulomonas, Propioniciclava and SRB was responsible for AMD bioremediation.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Many fluorophores/probes suffer from the interference of albumin in biosystems. Herein, we propose an effective strategy to overcome this interference by virtue of both an albumin‐insensitive ...fluorophore and its changeable π‐conjugation, and demonstrate the strategy by designing an oxazine‐based fluorogenic probe for aminopeptidase N (APN). The modification on the N atom in the oxazine fluorophore with alanine through a cleavable linker locks the resulting probe in a non‐conjugated, colorless and non‐fluorescent state, so the non‐specific interaction of albumin produces no spectroscopic response. APN can selectively cleave the alanine moiety, restoring the large π‐conjugation and strong fluorescence. The capability of the probe to eliminate the albumin influence has been demonstrated by imaging APN in different cell lines, and by quantitatively determining APN in human serum and mouse urine. The present strategy may be useful for developing more specific fluorogenic probes for other enzymes.
An oxazine‐based fluorogenic probe with a changeable π‐conjugated system for sensing the enzyme aminopeptidase N was developed, which effectively eliminated the false‐positive interference of albumin. The probe was used to detect the enzyme in cells, human serum and the mouse urine without the influence of albumin.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Silicon is one of the most promising alternative active materials for next-generation lithium-ion battery (LIB) applications due to its advantage of high specific capacity. However, the enormous ...volume variations during lithiation/delithiation still remain to be an obstacle to commercialization. In this work, binder-free pure silicon and silicon/carbon (Si/C) multilayer thin-film electrodes, prepared by scalable one-step magnetron sputtering, are systematically investigated by an interlayer strategy. Herein, we present a rationally structural modification by an amorphous carbon film to enhance the electrical conductivity, mechanical integrity, and electrochemical performance of Si film-based LIBs. Therefore, to maintain the consistency of the direct-contact layer with the electrolyte and current collection, symmetrical Si/C/Si and Si/C/Si/C/Si/C/Si electrodes are deliberately designed to study the influence of embedded carbon. An anode with a carbon content of 10.38 wt % yields an initial discharge specific capacity of 1888.74 mAh g–1 and a capacity retention of 96.82% (1243.56 mAh g–1) after 150 cycles at a high current density of 4000 mA g–1. It also shows that the best rate capability remains 96.0% of the initial capacity in the 70th cycle. At last, three mechanisms are proposed for an in-depth understanding of the interface effect. This work offers a new perspective scheme toward Si/C-based LIBs with a capability of high rate and high energy density.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
![A new pyrido[1,2-a]benzimid...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0003-2670/small "A new pyrido[1,2-a]benzimidazole-rhodamine FRET system as an efficient ratiometric fluorescent probe for Cu2+ in living cells")
