An N-Rich Polymer for the Selective Recovery of Gold from Wastewater.

The recovery of valuable gold from wastewater is of great interest because of the widespread use of the precious metal in various fields and the pollution generated by gold-containing wastes in water. In this paper, a water-insoluble cross-linked adsorbent material (TE) based on cyanuric chloride (TCT) and ethylenediamine (EDA) was designed and used for the adsorption of Au(III) from wastewater. It was found that TE showed extremely high selectivity (D = 49,213.46) and adsorption capacity (256.19 mg/g) for Au(III) under acidic conditions. The adsorption rate remained above 90% eVen after five adsorption-desorption cycles. The adsorption process followed the pseudo-first-order kinetic model and the Freundlich isotherm model, suggesting that physical adsorption with a multilayer molecular overlay dominates. Meanwhile, the adsorption mechanism was obtained by DFT calculation and XPS analysis, and the adsorption mechanism was mainly the electrostatic interaction and electron transfer between the protonated N atoms in the adsorbent (TE) and AuCl4-, which resulted in the redox reaction. The whole adsorption process was the result of the simultaneous action of physical and chemical adsorption. In conclusion, the adsorbent material TE shows great potential for gold adsorption and recovery.

Precise Control of Dissipative Self-assembly by Light and Electricity.

Nature-inspired synthetic dissipative self-assemblies have attracted much attention recently. However, it remains a major challenge to achieve precise control over dissipative supramolecular assembly structures and functions of self-contained systems. Here we combine light and electricity as two clean, and spatiotemporally addressable fuels to provide precise control over the morphology for dissipative self-assembly of a perylene bisimide glycine (PBIg) building block in a self-contained solution. In this design, electrochemical oxidation provides the positive fuel to activate PBIg self-assembly while photoreduction supplies the negative fuel to deactivate the system for disassembly. Through programming the two counteracting fuels, we demonstrated the control of PBIg self-assembly into a variety of assembly morphologies in a self-contained system. In addition, by exerting light and electrical dual fuels simultaneously, we could create an active homeostasis exhibiting dynamic instability, leading to morphological change to asymmetric assemblies with curvatures. Such precise control over self-assembly of self-contained systems may find future applications in programming complex active materials as well as formulating pharmaceutical reagents with desired morphologies.

Efficient Photoredox Cycles to Control Perylenediimide Self-Assembly.

Photoreduction of perylenediimide (PDI) derivatives has been widely studied for use in photocatalysis, hydrogen evolution, photo-responsive gels, and organic semiconductors. Upon light irradiation, the radical anion (PDI⋅- ) can readily be obtained, whereas further reduction to the dianion (PDI2- ) is rare. Here we show that full 2-electron photoreduction can be achieved using UVC light: 1) in anaerobic conditions by 'direct photoreduction' of PDI aggregates, or 2) by 'indirect photoreduction' in aerobic conditions due to acetone ketyl radicals. The latter strategy is also efficient for other dyes, such as naphthalenediimide (NDI) and methylviologen (MV2+ ). Efficient photoreduction on the minute time-scale using simple LED light in aerobic conditions is attractive for use in dissipative light-driven systems and materials.

MAP3K11 facilitates autophagy activity and is correlated with malignancy of oral squamous cell carcinoma.

Autophagy-related 4B (ATG4B) is a protease required for core machinery of autophagy. Phosphorylation of ATG4B promotes autophagy and is correlated with poor outcome of cancer. However, little is known about the upstream kinases for ATG4B phosphorylation and their association with clinical outcomes of cancer patients. Through siRNA library screening, MAP3K11 was identified as a potential kinase that phosphorylates ATG4B and increases its proteolytic activity. Ablation of MAP3K11 attenuated pS383/392-ATG4B protein levels and autophagic flux in oral cancer cells. Moreover, loss of MAP3K11 inhibited oral cancer cell growth, migration/invasion, and synergized starvation-reduced cell viability. MAP3K11 knock-out cancer cells also showed growth inhibition in vivo. Furthermore, the protein level of MAP3K11 was higher in tumor tissues than that in adjacent normal tissues in patients with oral squamous cell carcinoma (OSCC), comprising 179 buccal mucosa squamous cell carcinoma (BMSCC) and 249 tongue squamous cell carcinoma (TSCC). MAP3K11 protein levels were positively correlated with ATG4B and pS383/392-ATG4B levels in patients with OSCC, particularly in TSCC. In addition, high coexpression of MAP3K11 and ATG4B was associated with poor disease-specific survival in BMSCC and TSCC, while high coexpression of MAP3K11 and pS383/392-ATG4B was associated with unfavorable disease-free survival in BMSCC and TSCC. Taken together, our results indicated that MAP3K11 stimulated activity of ATG4B and autophagy, which may confer to malignancy of cancer cells. The expression of MAP3K11 and ATG4B was further associated with poor survival of OSCC, suggesting MAP3K11 could serve as a theranostic target of patients with OSCC.

Evaluation of cell-free DNA accuracy as diagnostic biomarker for prostate cancer: A systematic review and meta-analysis.

PURPOSE: This updated meta-analysis aimed to assess the diagnostic performance of circulating cell-free DNA (cf-DNA) for prostate cancer (PCa). METHODS: A systematic search was conducted in PubMed, Scopus, Web of Science, and Embase databases to retrieve related studies. Several diagnostic estimates, including sensitivity (SE), specificity (SP), likelihood ratios (LRs), and diagnostic odds ratio (DOR) were also used to perform the meta-synthesis. Additionally, the area under hierarchical summary receiver operating characteristic curves (AU-HSROC) was used as a global measure of test accuracy. RESULTS: Twenty-nine unique articles were enrolled in the meta-analysis. Pooled SE and SP for overall accuracy of cf-DNA in PCa were obtained as 0.54 (95% CI: 0.47-0.61) and 0.92 (95% CI: 0.88-0.95), respectively. Positive LR (PLR) was 6.8 (95% CI: 4.9-9.5, I2 : 92.98%) and negative LR (NLR) was 0.5 (95% CI: 0.43-0.58). Pooled DOR was 13.56 (95% CI: 9.49-19.37) and the AU-HSROC was 0.83 (95% CI: 0.79-0.86). CONCLUSION: The present study suggested that cf-DNA assays have comparable SE as well as remarkably higher SP (qualitative assays) than common biomarkers in the detection of PCa like prostate-specific antigen (PSA). In addition, cf-DNA assays have better performance in PCa confirmation and almost similar performance to PSA in excluding PCa patients.

Effect of EGFR on SQSTM1 Expression in Malignancy and Tumor Progression of Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) is one of the most common types of malignant tumor. Sequestosome 1 (SQSTM1) serves as an adaptor of autophagy for degrading protein aggregates. The regulation of autophagy by EGFR and its clinical impacts are indicated in various types of cancer. However, the association of EGFR and SQSTM1 in OSCC is still unknown. Our results show that the expression levels of SQSTM1 and EGFR proteins are higher in tumor tissues than in the corresponding tumor-adjacent (CTAN) tissues of OSCC patients. The expression levels of SQSTM1 were positively associated with the EGFR expression level. High co-expression of SQSTM1 and EGFR is associated with poor prognosis in OSCC patients. Moreover, SQSTM1 expression is decreased in EGFR-knockdown cells. Cell growth and invasion/migration are also decreased in cells with single/combined knockdowns of EGFR and SQSTM1 or in SQSTM1-knockdown cells without EGFR kinase inhibitor Lapatinib treatment compared to that in scrambled cells. However, cell growth and invasion/metastasis were not significantly different between the scrambled cells and SQSTM1-knockdown cells in the presence of Lapatinib. This study is the first to indicate the biological roles and clinical significance of SQSTM1 regulation by EGFR in OSCC.

Jungle rubber facilitates the restoration of degraded soil of an existing rubber plantation.

Conversion of forest to rubber plantation is one of the most common land-use change in the humid tropical region. It is one of the fastest expanding farms that lead to various socioenvironmental issues. We investigated the effect of this land-use change on soil physico-chemical properties by surveying different succession stage rubber plantations, including monoculture and a mixture derived by mixing jungle rubber and a reference tropical rainforest. We also assessed the impact on stoichiometric ratios and allocation relationships of soil carbon (C), nitrogen (N), and phosphorus (P). Our results demonstrated that conversion of tropical rainforest to rubber monoculture resulted in serious soil degradation, with a lower level of water content, water holding capacities, total porosity, pH, and soil nutrients, and a higher level of soil bulk density. However, after transforming a rubber monoculture into a jungle rubber, the concentrations of soil total C, N, P, Ca, and Mg significantly increased, by 28%, 24%, 23%, 17%, and 39%, respectively. Meanwhile, soil salinity declined by 15%. Jungle rubber also exerted some desirable effects on soil physical properties, such as decreased soil bulk density, increased field capacity and non-porosity by 6%, 2%, and 33%, respectively. Like other tropical regions, soils in the present study areas are mainly under P limitation, but jungle rubber increased soil P turnover and thereby increases P availability. In conclusion, jungle rubber correcting the soil degradation resulted from rubber plantation on tropical forest soil. Given the improvements in soil quality, constructing multiple-strata and multi-species rubber agroforestry (e.g., jungle rubber) can be a promising approach to facilitate the restoration of the existing monoculture rubber plantations.

Effects of hillslope position on soil water infiltration and preferential flow in tropical forest in southwest China.

The hillslope is an essential natural spatial gradient that influences hydrological processes by affecting water distribution, surface flow, soil erosion, and groundwater recharge. To date, few studies have addressed only the hydrological processes of tropical forest hillslopes. To reveal the effect of hillslope on soil hydrological functioning-including water distribution and exchange, infiltration capacity, and flow behaviour-we conducted 36 field infiltration and nine dye-tracer investigations of different hillslope locations in the natural rainforest of Xishuangbanna, southwest China. The soil physical properties-including soil noncapillary and total porosity, saturated water capacity, and field water capacity-decreased with decreasing elevation from hilltop to middle slope and the valley bottom. The water infiltration capacity-including the initial infiltration rate, saturated soil hydraulic conductivity, and average infiltration rate-decreased from the hilltop to the valley bottom. Preferential flow dominated soil water movement more in the upper locations than in the valley bottom. The infiltration capacity parameters and preferential flow were significantly correlated with soil water content, noncapillary and total porosity, root biomass, and termite holes. These results indicated that along with the soil physical properties, root systems, animal activity, cracks, and stones affected the soil infiltration capacity and preferential flow. Differences in the hydraulic processes of each hillslope position contributed to the redistribution, transportation, and storage of surface and belowground water, resulting in differing availabilities of soil water resources and utilisation by plants. The findings of this study can help understand eco-hydrological processes in the context of water resources management in tropical mountain ecosystems.

Soil quality assessment of different Hevea brasiliensis plantations in tropical China.

Land degradation is a global problem caused by improper agricultural practices. In tropical China, the rubber (Hevea brasiliensis) plantations are predominantly practiced on forest-cleared lands, considering their sustainable land management potential compared to annual cropping. However, all rubber plantations may not have similar land management capacity. Soil quality index (SQI) can reveal the overall soil status with a single score, which is an efficient tool to evaluate the soil quality of each category of rubber plantations. We investigated 23 soil physical and chemical parameters of three categories of rubber plantations and a primary rainforest, and derived SQI based on these parameters. Soil samples were collected from a rubber monoculture (RM), a rubber-Camellia sinensis agroforestry (RT), a rubber-Dracaena cochinchinensis agroforestry (RD), and a primary rainforest (RF). The results showed that the SQI value of the RM decreased by 15.50% compared to the RF, with a significant degree of soil nutrient loss (18.90%). This indicates that monocultural rubber cultivation is causing land degradation to some extent. However, the SQI was significantly enhanced by rubber-based agroforestry practices (25.30% by RT and 33.10% by RD) compared to the RM, suggesting that polyculture practices are suitable to recover the soil quality in degraded agricultural lands. Moreover, the chemical parameters contributed more to the SQI than did the physical parameters, indicating that nutrient management is important in soil quality recovery. Overall, our results suggest that agroforestry should be preferred over monoculture in the rubber plantations for sustainable land management in tropical China.

Osteomyocutaneous Free Fibula Flap Prevents Osteoradionecrosis and Osteomyelitis in Head and Neck Cancer Reconstruction.

BACKGROUND: Osteoradionecrosis (ORN) is one of the most severe complications of free fibula reconstruction after radiotherapy. The gold standard treatment of osteomyelitis involves extensive debridement, antibiotics, and sufficiently vascularized muscle flap coverage for better circulation. Therefore, we hypothesized that free fibula flap with muscle could decrease the risk of ORN. METHODS: This study consisted of 85 patients who underwent reconstruction with free fibula flap in head and neck cancer by a single reconstructive surgeon at Kaohsiung Veterans General Hospital over a period of 19 years (1998-2016). Patients with postoperative adjuvant radiotherapy were included in the study and were grouped by either free fibula osteocutaneous flap or free fibula osteomyocutaneous flap (with flexor hallucis longus muscle), and the incidence of ORN was compared. RESULTS: Of the 85 patients, 15 were reconstructed with osteocutaneous fibula flap and 70 were with osteomyocutaneous fibula flap. The rate of ORN or osteomyelitis was significantly lower in the muscle group (18.6%, n = 13/70 vs. 46.7%, n = 7/15, p = 0.020, Chi-square test). CONCLUSION: Vascularized muscle transfer increases perfusion of surrounding tissues and the bone flap, thereby decreasing the incidence of osteomyelitis or osteonecrosis.

A novel and sensitive electrochemical sensor based on nanoporous gold for determination of As(III).

Three-dimensional porous gold nanoparticles (NPG) were synthesized in situ on indium-doped tin oxide (ITO) substrates by a green and convenient one-step electrodeposition method to achieve super-sensitive As(III) detection. The introduction of NPG method not only greatly improves the electron transfer capacity and surface area of sensor interface but provides more active sites for As(III) enrichment, thus boosting sensitivity and selectivity. The sensor was characterized by scanning electron microscopy, energy dispersion spectroscopy, differential pulse anode stripping voltammetry (DPASV), and electrochemical impedance to evaluate its morphology, composition, and electrochemical performance. The wall thickness of NPG was customized by optimizing the concentration of electroplating solution, dissolved electrolyte, deposition potential, and reaction time. Under optimal conditions, the electrochemical sensor showed a wide linear range from 0.1 to 50 µg/L As(III), with a detection limit (LOD) of 0.054 µg/L (S/N = 3). The LOD is far below 10 µg/L, the recommended maximum value by the world health organization for drinking water. Stability, reproducibility, and repeatability of NGP/ITO were determined to be 2.77%, 4.9%, and 4.1%, respectively. Additionally, the constructed sensor has been successfully applied to determine As(III) in three actual samples, and the results are in good agreement with that of hydride generation atomic fluorescence spectrometry (AFS). Graphical abstract.

Decay and erosion-related transport of sulfur compounds in soils of rubber based agroforestry.

Elemental sulfur is intensively used to control weeds and rubber leaf diseases. However, the mechanisms contributing to elemental sulfur dissipation and decay (hereafter decay) in rubber agroforestry remains unclear. This study relates hydrological processes such as runoff and soil loss to the changes in soil total sulfur (Stot) and sulfate (S-SO4) in typical hillslope rubber agroforestry intercropped with cocoa in Xishuangbanna. The elemental sulfur decay kinetics were studied at two slopes (top and bottom) and three agrosystems (weed, no-weed and mixed). The results show that soil moisture and hydraulic conductivity was uniformly distributed in the experimental rubber agroforestry settings. Higher soil loss and runoff occurred in the bottom slope than the top slope, and in no-weed agrosystem than the herbaceous agrosystems (weed and mixed). The soil loss was mainly driven by runoff. Moreover, Stot and S-SO4 in runoff water were higher in weed agrosystem than no-weed agrosystems. Soil Stot best fit a two-compartments kinetics model, with lower kinetic rates in elemental sulfur applied treatments than in the no-added elemental sulfur treatments, particularly for the weed agrosystem. The soil Stot dissipation time 50% (DT50) was 10-14 times higher in top slope than bottom slope; but 4 and 20 times higher in mixed and no-weed agrosystems, respectively, compared to the weed agrosystem. The soil Stot and S-SO4 contents negatively correlated with soil microbial respiration (CO2 efflux), indicating an adverse influence of elemental sulfur on soil microbial activity. In short, elemental sulfur decay and its S-SO4 transformation depended on soil moisture, runoff, soil erosion and soil CO2, which are in turn affected by slope and agrosystem. This study not only clarifies the mechanisms of elemental sulfur dissipation and decay for its use as an environmental friendly agrochemical; but it also provides information to understand the contribution of runoff and soil loss on these mechanisms in rubber agroforestry.

An Efficient Synthesis of Spiro[indoline-3,9'-xanthene]trione Derivatives Catalyzed by Magnesium Perchlorate.

A simple and efficient method for the synthesis of spiro[indoline-3,9'-xanthene]trione derivatives by means of condensation between isatins and 1,3-cyclohexanedione in the presence of a catalytic amount of magnesium perchlorate at 80 °C in 50% aqueous ethanol medium has been described. Notably, the present method offers desirable advantages of good yields, simplicity of workup procedure, easy purification, and reduced reaction times.

Supramolecular Chirality of the Two-Component Supramolecular Copolymer Gels: Who Determines the Handedness?

Natural supramolecular systems typically contain a wide variety of chiral molecules. Studying the chiral conflict within different supramolecular assemblies not only can be very helpful for understanding the inherent principles of supramolecular chirality but also can guide the preparation of many functional chiral soft matters. For assemblies containing only structurally similar molecules, supramolecular chirality is determined by enantiomeric excess of molecular building blocks. For supramolecular systems assembled by structurally different chiral molecules, however, the optical activity of the systems and the chiral conflict among different chiral molecules can be very complex. We found rather unexpected results regarding the chiral conflict within two-component supramolecular copolymer gels in this study. The handedness of the chirality of supramolecular copolymer gels, which were formed by the coassembly of bolaamphiphilic L-histidine derivatives and tartaric acids, was found to be dependent on the ordering molecular packing, instead of the preponderance of certain chiral molecules.

Serum leptin level measured 48 h after delivery is associated with development of postpartum depressive symptoms: a 3-month follow-up study.

The aim of this study was to assess the possible relationship between leptin status and postpartum depressive symptoms using serum levels of leptin collected 24-48 h after delivery in a cohort Chinese sample. Women delivering a full-term, singleton, and live-born infant in the period from August 2013 to March 2014 were enrolled immediately postpartum. A blood sample was obtained 24-48 h after childbirth to test serum levels of leptin. Participation consisted of a visit in an obstetric unit at 3 months after delivery. The Edinburgh Postnatal Depression Scale (EPDS), completed at 3 months postpartum, was used to classify each woman's depression symptom severity. Demographic, obstetric, behavioral risk, mental health, and psychosocial factors were considered. Multiple logistic regression analyses were used to identify risk factors most predictive of postpartum depressive symptoms. During the study period, 407 individuals were included and completed follow-up. At 3 months, according to EPDS score, 53 women (13.0 %) were considered as postpartum depressive symptoms. Serum leptin levels in women with PPD were significantly greater than those in women without depressive symptoms (36.5 [IQR, 25.5-50.4] vs. 14.5 [IQR, 9.4-22.4] ng/ml, P < 0.0001). Based on the ROC curve, the optimal cutoff value of serum leptin levels as an indicator for predicting of depressive symptoms was projected to be 24.3 ng/mL, which yielded a sensitivity of 88.7 % and a specificity of 73.4 %, with the area under the curve at 0.867 (95 % CI, 0.817-0.916). In multivariate analysis, there was an increased risk of depressive symptoms associated with leptin levels ≥24.3 ng/ml (OR 8.234; 95 % CI, 3.572-15.876; P < 0.0001) after adjusting for possible confounders. Elevated serum leptin levels at delivery could eventually serve as a biological marker for the prediction of depressive symptoms. These associations were independent of other possible variables.

Therapeutic effect in patients with coronary heart disease based on information analysis from traditional Chinese medicine four diagnostic methods.

OBJECTIVE: To study information gained by Traditional Chinese Medicine (TCM) four diagnostic methods and characteristics of syndrome development before and after treatment in patients with coronary heart disease, and to probe into assessment indexes of therapeutic effects with distinctive TCM features. METHODS: Information from the four diagnostic methods before and after treatment in 100 patients with coronary heart disease was collected using the TCM interrogation scale, a pulse condition instrument, a tongue-face diagnosis instrument, and a voice diagnosis information collection system. Changes in the four diagnostic method results from before and after treatment were analyzed with frequency analysis and t-test methods. RESULTS: Before treatment, deficiency syndrome complicated with hyperactivity of pathogenic factors was most common. After treatment, deficiency syndrome was most common. This change from complex syndromes to single syndromes indicates disease and syndrome alleviation. Frequencies of symptoms gained by interrogation after treatment for syndrome of deficiency of heart-Qi, syndrome of deficiency of heart-Yin, and turbid phlegm syndrome were all less severe than those before treatment. Parameters of face color, color on all sub-regions of tongue, color of tongue fur, septic and greasy fur, and lip color after treatment all had significant changes. After treatment, part of the voice diagnosis parameters in the deficiency of heart-Yin and turbid phlegm syndromes had significant changes, but no significant changes were found in the deficiency of heart-Qi syndrome. CONCLUSION: Use of the TCM four diagnostic methods can provide an effective basis for TCM syndrome diagnosis, observation of development of state of illness, and evaluation of clinical therapeutic effects.

Use of customized 3-dimensional printed mandibular prostheses with a dental implant pressure-reducing device in mandibular body defect: A finite element study performing multiresponse surface methodology.

Background/purpose: Segmental body defects of the mandible result in the complete loss of the affected region. In our previous study, we investigated the clinical applicability of a customized mandible prosthesis (CMP) with a pressure-reducing device (PRD) in an animal study. In this study, we further incorporated dental implants into the CMP and explored the use of dental implant PRD (iPRD) designs. Materials and methods: By employing a finite element analysis approach, we created 4 types of CMP: CMP, CMP with iPRD, CMP-PRD, and CMP-PRD with iPRD. We developed 2 parameters for the iPRD: cone length (CL) in the upper part and spring pitch (SP) in the lower part. Using the response surface methodology (RSM), we determined the most suitable structural assignment for the iPRD. Results: Our results indicate that CMP-PRD had the highest von Mises stress value for the entire assembly (1076.26 MPa). For retentive screws and abutments, CMP with iPRD had the highest von Mises stress value (319.97 and 452.78 MPa, respectively). CMP-PRD had the highest principal stress (131.66 MPa) in the anterior mandible. The iPRD reduced principal stress in both the anterior and posterior mandible. Using the RSM, we generated 25 groups for comparison to achieve the most favorable results for the iPRD and we might suggest the CL to 12 mm and the SP to 0.4 mm in the further clinical trials. Conclusion: Use of the PRD and iPRD in CMP may resolve the challenges associated with CMP, thereby promoting its usage in clinical practice.

Oral soft tissue biopsy surgery: Current principles and key tissue stabilization techniques.

There are different kinds of benign and malignant lesions in the oral cavity. Clinically, definite diagnosis can be confirmed only by doing adequate surgical biopsy and subsequent histopathological examination. Inadequate biopsy technique, unsuitable selection of the location for biopsy, inappropriate tissue handling and record of patients' information may lead to artifacts and misdiagnosis by the oral pathologists. Soft tissue stabilization is a challenge during oral surgery procedures. It needs the cooperation of operator, assistants, and patients to overcome the difficulty and ensure the successful outcome. In this article, we reviewed the procedures for clinical surgical biopsy, and raised three current tissue stabilization methods including fingers and gauze stabilization, stabilization with chalazion forceps and adapted instruments, and stabilization with retraction sutures. Moreover, some limitations were also presented. Clinician should examine the clinical characteristics of the oral lesion, the surrounding anatomical structures, and their own clinical experience and preference to select the appropriate tool. More understanding of these biopsy and tissue stabilization methods can effectively improve the biopsy procedures and obtain adequate tissues for histopathological examination and subsequent issue of an accurate pathological report.

The use of customized 3D-printed mandibular prostheses with pressure-reducing device: A clinical trial.

BACKGROUND: Segmental bone defects of the mandible result in the complete loss of the affected region. We had incorporated the pressure-reducing device (PRD) designs into the customized mandible prostheses (CMP) and conducted a clinical trial to evaluate this approach. METHODS: Seven patients were enrolled in this study. We examined the association among the history of radiotherapy, the number of CMP regions, the number of chin regions involved, and CMP exposure. RESULTS: We included five men and two women with an average age of 55 years. We excised tumors with an average weight of 147.8 g and the average weight of the CMP was 68.5 g. No significant difference between the two weights was noted (p = 0.3882). Three patients received temporary dentures and the CMP remained stable in all patients. CONCLUSION: The use of PRD in CMP may address the previous challenges associated with CMP, but further research is necessary.

Investigating the recovery in ecosystem functions and multifunctionality after 10 years of natural revegetation on fly ash technosol.

Technogenic soil (technosol) developed from coal fly ash (FA) landfilling has been considered a critical environmental problem worldwide. Drought-tolerant plants often naturally grow on FA technosol. However, the impact of these natural revegetations on the recovery of multiple ecosystem functions (multifunctionality) remains largely unexplored and poorly understood. Here we assessed the response of multifunctionality, including nutrient cycling (i.e., carbon, nitrogen, and phosphorus), carbon storage, glomalin-related soil protein (GRSP), plant productivity, microbial biomass carbon (MBC), microbial processes (soil enzyme activities), and soil chemical properties (pH and electrical conductivity; EC) to FA technosol ten years' natural revegetation with different multipurpose species in Indo-Gangetic plain, and identified the key factors regulating ecosystem multifunctionality during reclamation. We evaluated four dominant revegetated species: Prosopis juliflora, Saccharum spontaneum, Ipomoea carnea, and Cynodon dactylon. We found that natural revegetation initiated the recovery of ecosystem multifunctionality on technosol, with greater recovery under higher biomass-producing species (P. juliflora and S. spontaneum) than lower biomass-producing ones (I. carnea and C. dactylon). The individual functions (11 of the total 16 variables) at higher functionality (70 % threshold) also exhibited this pattern among revegetated stands. Multivariate analyses revealed that most of the variables (except EC) significantly correlated with multifunctionality, indicating the capability of multifunctionality to consider the tradeoff between individual functions. We further performed structural equation modeling (SEM) to detect the effect of vegetation, pH, nutrients, and microbial activity (MBC and microbial processes) on ecosystem multifunctionality. Our SEM model predicted 98 % of the variation in multifunctionality and confirmed that the indirect effect of vegetation mediated by microbial activity is more important for multifunctionality than their direct effect. Collectively, our results demonstrate that FA technosol revegetation with high biomass-producing multipurpose species promotes ecosystem multifunctionality and emphasizes the significance of microbial activity in the recovery and maintenance of ecosystem attributes.