Pollution levels and probability risk assessment of potential toxic elements in soil of Pb-Zn smelting areas.

Soil pollution around Pb-Zn smelters has attracted widespread attention around the world. In this study, we compiled a database of eight potentially toxic elements (PTEs) Pb, Zn, Cd, As, Cr, Ni, Cu, and Mn in the soil of Pb-Zn smelting areas by screening the published research papers from 2000 to 2023. The pollution assessment and risk screening of eight PTEs were carried out by geo-accumulation index (Igeo), potential ecological risk index (PERI) and health risk assessment model, and Monte Carlo simulation employed to further evaluate the probabilistic health risks. The results suggested that the mean values of the eight PTEs all exceeded the corresponding values in the upper crust, and more than 60% of the study sites had serious Pb and Cd pollution (Igeo > 4), with Brazil, Belgium, China, France and Slovenia having higher levels of pollution than other regions. Besides, PTEs in smelting area caused serious ecological risk (PERI = 10912.12), in which Cd was the main contributor to PREI (86.02%). The average hazard index (HI) of the eight PTEs for adults and children was 7.19 and 9.73, respectively, and the average value of total carcinogenic risk (TCR) was 4.20 × 10-3 and 8.05 × 10-4, respectively. Pb and As are the main contributors to non-carcinogenic risk, while Cu and As are the main contributors to carcinogenic risk. The probability of non-carcinogenic risk in adults and children was 84.05% and 97.57%, while carcinogenic risk was 92.56% and 79.73%, respectively. In summary, there are high ecological and health risks of PTEs in the soil of Pb-Zn smelting areas, and Pb, Cd, As and Cu are the key elements that cause contamination and risk, which need to be paid attention to and controlled. This study is expected to provide guidance for soil remediation in Pb-Zn smelting areas.

Immunosuppressive CD10+ALPL+ neutrophils promote resistance to anti-PD-1 therapy in HCC by mediating irreversible exhaustion of T cells.

BACKGROUND & AIMS: Remodeling the tumor microenvironment is a critical strategy for treating advanced hepatocellular carcinoma (HCC). Yet, how distinct cell populations in the microenvironment mediate tumor resistance to immunotherapies, such as anti-PD-1, remains poorly understood. METHODS: We analyzed the transcriptomic profile, at a single-cell resolution, of tumor tissues from patients with HCC scheduled to receive anti-PD-1-based immunotherapy. Our comparative analysis and experimental validation using flow cytometry and histopathological analysis uncovered a discrete subpopulation of cells associated with resistance to anti-PD-1 treatment in patients and a rat model. A TurboID-based proximity labeling approach was deployed to gain mechanistic insights into the reprogramming of the HCC microenvironment. RESULTS: We identified CD10+ALPL+ neutrophils as being associated with resistance to anti-PD-1 treatment. These neutrophils exhibited a strong immunosuppressive activity by inducing an apparent "irreversible" exhaustion of T cells in terms of cell number, frequency, and gene profile. Mechanistically, CD10+ALPL+ neutrophils were induced by tumor cells, i.e., tumor-secreted NAMPT reprogrammed CD10+ALPL+ neutrophils through NTRK1, maintaining them in an immature state and inhibiting their maturation and activation. CONCLUSIONS: Collectively, our results reveal a fundamental mechanism by which CD10+ALPL+ neutrophils contribute to tumor immune escape from durable anti-PD-1 treatment. These data also provide further insights into novel immunotherapy targets and possible synergistic treatment regimens. IMPACT AND IMPLICATIONS: Herein, we discovered that tumor cells reprogrammed CD10+ALPL+ neutrophils to induce the "irreversible" exhaustion of T cells and hence allow tumors to escape from the intended effects of anti-PD-1 treatment. Our data provided a new theoretical basis for the elucidation of special cell populations and revealed a molecular mechanism underpinning resistance to immunotherapy. Targeting these cells alongside existing immunotherapy could be looked at as a potentially more effective therapeutic approach.

Occurrence of halogenated methanesulfonic acids in water and sediment from the Hangzhou Bay, China.

Halogenated methanesulfonic acids (HMSAs) are an important new class of organic compounds as they were universal in the water cycle and drinking water sources. However, no study has investigated the presence of HMSAs in surface water and sediment from China. The present study reports the occurrence and spatiotemporal distribution of seven HMSAs in water and sediment samples from Hangzhou Bay, China. Trifluoromethanesulfonic acid (TFMSA) was the main contributor to the concentrations of HMSAs in water and sediment samples from spring, summer, autumn and winter which were 30.8-541 ng/L, n. d.-86.6 ng/L, 4.22-70.9 ng/L and 8.86-192 ng/L, separately, while in sediment samples were n. d.-11.1 ng/g, n. d.-12.9 ng/g, n. d.-22.5 ng/g, n. d.-4.60 ng/g, respectively. The levels of HMSAs in water from winter and spring were higher than those in summer and autumn, and the concentrations of the target HMSAs in water presents a seasonal pattern affected by the temperature, the precipitation and river flow variations. Nevertheless, the levels of HMSAs in sediment were highest in the area near the industrial area and the confluences of rivers. Correlation analysis revealed that the concentrations of TFMSA were significantly positively correlated with total organic carbon (TOC) in water samples. Although TFMSA is regarded as low toxic based on the EC50 value of acute toxicity, the potential risks to aquatic ecology should be paid more attention due to its high concentrations in the aquatic system and the environmental persistency.

Endoscopic retrograde appendicitis therapy versus laparoscopic appendectomy versus open appendectomy for acute appendicitis: a pilot study.

BACKGROUND: An increasing number of studies have shown the merits of endoscopic retrograde appendicitis therapy (ERAT) in diagnosing and treating acute uncomplicated appendicitis. However, no related prospective controlled studies have been reported yet. Our aim is to assess the feasibility and safety of ERAT in the treatment of acute uncomplicated appendicitis. METHODS: In this open-label, randomized trial, participants were randomly allocated to the ERAT group, laparoscopic appendectomy (LA) group and open appendectomy (OA) group. The primary outcome was the clinical success rate of the treatment. Intention-to-treat analysis was used in the study. RESULTS: The study comprised of 99 patients, with 33 participants in each group. The clinical success rate was 87.88% (29/33), 96.97% (32/33) and 100% (33/33) in the ERAT, LA and OA group, respectively. In the ERAT group, 4 patients failed ERAT due to difficult cannulation. In LA group, 1 patient failed because of abdominal adhesion. There were no significant differences among the three treatment groups regarding the clinical success rate (P = 0.123). The median duration of follow-up was 22 months. There were no significant differences (P = 0.693) among the three groups in terms of adverse events and the final crossover rate of ERAT to surgery was 21.21% (7/33). CONCLUSION: ERAT can serve as an alternative and efficient method to treat acute uncomplicated appendicitis. Trial registration The study is registered with the WHO Primary Registry-Chinese Clinical Trial Registry (ChiCTR1900025812).

Exposure to antibiotics and precocious puberty in children: A school-based cross-sectional study in China.

Foods and water can be contaminated with antibiotics in China, which may affect children's health, but evidence on antibiotic exposure with precocious puberty (PP) is limited. This study explored the association of antibiotic exposure with PP in a school-based setting. A cross-sectional study with multistage stratified cluster random sampling was conducted in Zhongshan City, Guangdong Province and Qufu City, Shandong Province in China from October 11 to December 5, 2019. A first-morning urine sample was collected to detect antibiotic exposure. We detected 33 of 45 types of antibiotics from eight categories in 928 primary school children aged 6-12 years using HPLS-MS/MS. Detection rate of antibiotics was stratified by sex, study site, and BMI. The Tanner stages were assessed by professional pediatricians from local hospitals. PP is defined as the onset of secondary characters before 8-year-old or menarche before 10-year-old for girls and before 9-year-old for boys. Multivariable logistic regression was performed to examine the association between antibiotic exposure and PP after adjusting potential confounders. The overall detection rate of antibiotics was 93.0% in 928 children. We found the detection rate of tetracyclines and fluoroquinolones in children with PP was significantly higher than that of children with normal puberty (41.4% vs 29.9%, 56.8% vs 50.6%, respectively, all p < 0.05). Both fluoroquinolones (odds ratio (OR): 1.835, 95% confidence interval (CI): 1.066-3.158) and tetracyclines (OR: 2.120, 95% CI: 1.175-3.825) were associated with increased OR of PP after adjusting sex, age, BMI, study site, and family income. Specifically, compared to the values less than the limits of detection, low concentration of ofloxacin from fluoroquinolones (OR: 2.056, 95% CI: 1.091-3.875) and high concentration of chlortetracycline (OR: 3.027, 95% CI: 1.126-8.140) and tetracycline from tetracyclines (OR: 2.756, 95% CI: 1.167-6.506) were associated with increased OR of PP. Exposure to antibiotics, especially fluoroquinolones and tetracyclines was positively associated with precocious puberty.

QSAR model and mechanism research on color removal efficiency of dying wastewater by FeCl3 coagulation.

Coagulation is the most widely used method in the treatment of printing and dying wastewater. To better understand the relationship between the coagulation effect and dye molecular structures, quantitative structure activity relationship (QSAR) analyses were performed to elucidate the factors affecting the coagulation in ferric chloride (FeCl3) coagulation process. First, the coagulation experiments on 38 dye molecules were conducted to determine their color removal rates (Rexp) by FeCl3 under different pH conditions (i.e., pH = 4 and 10). The results showed that the average Rexp of dyes were 41.36% ± 2.40% at pH value of 4 and 55.70% ± 2.83% at pH value of 10. Subsequently, a multiple linear regression (MLR) method was used to construct QSAR models based on Rexp and 42 molecular parameters calculated by Gaussian 09, Materials Studio 7.0 and Multiwfn. The developed QSAR models exhibited excellent stability, reliability, and robustness with values of R2 = 0.7950, 0.8170, Q2INT = 0.6401, 0.7382, Q2EXT = 0.5168, 0.5441, at pH values of 4 and 10, respectively. Through analysis of quantum parameter values, electrostatic adsorption and hydrogen bonding adsorption were primarily responsible for the coagulation process. Therefore, this study could be useful in providing critical information for evaluating the removal efficiency and a feasible way to predict the removal rate of dyes by FeCl3 when no coagulation experiments were conducted.

Application of QSAR for investigation on coagulation mechanisms of textile wastewater.

Coagulation is an effective preliminary treatment process for textile wastewater. In order to evaluate the effectiveness of the coagulation process, we performed quantitative structure activity relationship (QSAR) analyses with total organic carbon (TOC) removal rates (Rexp) as an index by three different coagulants (AlCl3, FeCl3, and MgCl2). The experimental results showed that the average Rexp of the three coagulants was 39.12% ± 2.60%, 51.60% ± 2.88%, and 49.95% ± 3.17%. Subsequently, 42 molecular descriptors of dye molecules were calculated by quantitative calculation softwares Gaussian 09, Material Studio 7.0, and Multiwfn 3.7, and then QSAR models were constructed by a multiple linear regression (MLR) method for the three coagulation systems. The developed QSAR models demonstrated excellent stability, robustness, and predictability with values of R2 = 0.7677, 0.8015, and 0.7035, Q2INT = 0.6067, 0.7026, and 0.5898, Q2EXT = 0.5505, 0.5076, and 0.5697, respectively. Based on the analysis of quantum parameters, the coagulation mechanism for AlCl3, FeCl3 is primarily electrostatic adsorption as well as hydrogen bonding, while MgCl2 coagulates dyes mainly by electrostatic adsorption. This study provides an assessment of the removal rules and a feasible method for predicting dye removal rates in AlCl3, FeCl3, and MgCl2 coagulation process.

Antibiotic exposure and risk of overweight/obesity in school children: A multicenter, case-control study from China.

BACKGROUND: Although the use of antibiotics during early life has been associated with increased risk of adipogenesis, effect of antibiotic exposure from various sources, including food or drinking water, on adiposity in children is largely unknown. OBJECTIVE: To investigate associations between urinary biomarkers of multiple antibiotics and risk of adipogenesis in school children. METHODS: This case-control study recruited 410 overweight/obese school children aged 6-9 years and 410 controls from Shandong and Guangdong Province, China, matched on sex, age and school. Diagnosis of overweight and obesity was based on body mass index-based criteria derived from national data. Urinary concentrations of 45 antibiotics from 8 categories (macrolides, ß-lactams, tetracyclines, fluoroquinolones, sulfonamides, phenicols, lincosamides, and quinoxalines), including 6 human antibiotics (HAs), 6 antibiotics preferred as HAs (PHAs), 16 veterinary antibiotics (VAs), and 17 antibiotics preferred as VA (PVAs), were measured by ultra-performance liquid chromatography coupled to triple-quadrupole tandem mass spectrometry. Conditional logistic regression analyses were used to assess odds ratios (ORs) of childhood overweight/obesity in relation to urinary antibiotic concentrations. RESULTS: A total of 32 antibiotics were found in urine samples with an overall detection frequency of 92.93 %. Children with overweight/obesity have higher veterinary antibiotic levels than those with normal weight. Compared with undetected levels of antibiotics, the multivariable-adjusted ORs (95 % confidence interval) of overweight/obesity for high levels of antibiotics divided according to median values were 1.63 (1.02, 2.62) for florfenicol, 1.62 (1.04, 2.54) for phenicols, and 1.41 (0.97, 2.04) for sum of VAs and PVAs. These associations predominantly existed in boys and remained significant in florfenicol after FDR multiple testing correction (FDR adjusted p < 0.05). CONCLUSION: Exposure to certain antibiotic for veterinary use mainly from food or drinking water was associated with an increased risk of adipogenesis in children. Further studies are needed to confirm our findings and clarify the underlying mechanisms.

Occurrence, health risk assessment and water quality criteria derivation of six personal care products (PCPs) in Huangpu River, China.

Personal care products (PCPs) have shown adverse health effects on humans. However, their health risk associated with fish consumption and relevant water quality criteria are still not well documented. This study investigated the occurrence and health risk of six PCPs (triclosan, bisphenol-A, and four commonly used organic ultraviolet (UV) filters, i.e., homosalate (HMS), 4-methylbenzylidene camphor (4-MBC), oxybenzone (BP-3), and octocrylene (OC)). River water and three trophic levels of fish species were collected from Huangpu River in Shanghai. The concentration range of the six PCPs were 1.48-89.76 ng/L in water and 0.40-10.75 ng/g dry weight in fish. Estimated daily intake (EDI) and target hazard quotient (THQ) of the PCPs indicated that consuming these fish would not pose non-carcinogenic risks. The maximum allowable fish consumption rates ranged from 85 to 1760 and 155 to 3230 meals per month for children and adults, respectively. As to the four organic UV filters, it is the first time to report the fish consumption advisories. Finally, the human health ambient water quality criteria (AWQC) values of HMS, 4-MBC, BP-3, OC, TCS, and BPA (i.e., 0.1218, 0.7311, 0.3494, 0.0477, 235.8, and 154.7 µg/L, respectively) were proposed, and they can serve as a valuable technical reference for global development and revision of aquatic environmental quality standards for these emerging contaminants.

Metabolic syndrome components and acute pancreatitis: a case-control study in China.

BACKGROUND: Acute pancreatitis (AP) is a common inflammatory disorder of the pancreas. Recent evidence has shown that metabolic syndrome is positively correlated with the severity of AP. However, only a few studies have revealed the relationship between metabolic syndrome and the occurrence of AP. We therefore elucidated the association between metabolic syndrome and the occurrence of AP. METHODS: A hospital-based case-control study was conducted. A total of 705 patients admitted to our hospital from January 2016 to December 2018 were included in the study. Subjects were divided into case and control groups according to their diagnosis: (1) According to the revised Atlanta classification from 2012, patients diagnosed with AP were enrolled in the case group. (2) Patients without a history of AP or any disease related to metabolic syndrome were allocated into the control group. Controls were matched to cases individually by sex and age (control/case ratio = 1). RESULTS: The incidence rate of metabolic syndrome in AP patients was 30.9%, which was more frequent than that in controls (13.2%) (OR 2.837; 95% CI 1.873-4.298, p < 0.001). In the multivariate regression analysis, a history of smoking or alcohol consumption and biliary stones were significantly associated with AP (OR 2.441; 95% CI 1.865-5.172, p < 0.001; OR 1.777; 95% CI 1.060-2.977, p = 0.029; OR 28.995; 95% CI 13.253-63.435, p < 0.001). In addition, the occurrence of AP was significantly associated with total cholesterol (TC) (OR 1.992; 95% CI 1.246-3.183, p = 0.004), triglyceride (TG) (OR 2.134; 95% CI 1.403-3.245, p < 0.001), hyperglycaemia (OR 2.261; 95% CI 1.367-3.742, p = 0.001), and apolipoprotein A (Apo A) (OR 0.270; 95% CI 0.163-0.447, p < 0.001). CONCLUSIONS: Metabolic syndrome and its components were associated with AP occurrence.

Boosting electrochemical nitrogen reduction reaction performance of two-dimensional Mo porphyrin monolayers via turning the coordination environment.

Designing atomically dispersed metal catalysts for the nitrogen reduction reaction (NRR) is an effective approach to achieve better energy conversion efficiencies. In this study, we designed a series of single molybdenum (Mo) atom-anchored porous two-dimensional Mo porphyrin (2D Mo-Pp) monolayers modified by B, C, O, P and S as efficient NRR catalysts to improve the catalytic performance. We introduced two key parameters, θ (pz orbital filling of heteroatoms) and φ (Bader charge of central Mo atoms). It shows that θ and φ play important roles in nitrogen absorption by analyzing the regression models. In particular, the theoretical results suggested that the 2D Mo-Pp monolayer modified by B has an ultralow limiting potential of 0.35 V and can suppress the hydrogen evolution reaction, making the 2D Mo-Pp monolayer modified by B a promising NRR electrocatalyst with high efficiency and selectivity. This work provides insights into the rational design of the elaborate structure of single-atom catalysts with tunable electrocatalytic activities.

Acute toxicity assessment of indoor dust extracts by luminescent bacteria assays with Photobacterium Phosphoreum T3.

In the last decades, there has been an increasing concern about the human exposure to indoor dust. Therefore, it is imperative to assess the toxicity of indoor dust and associated dust extracts. In this study, the acute toxicity assessment of indoor dust was performed using a bioluminescence test, with Photobacterium phosphoreum T3 (PPT3) chosen as the test bacterium. The different indoor dust samples were collected from residences, offices, dormitories and laboratories in Shanghai, China. Our data reveal that PPT3 is more active to water-soluble ions and organic contaminants at low concentrations, while extract solutions elicit increased bacterial toxicity at high concentrations. The results of a bioluminescence assay by PPT3 indicated that the dust organic extracts exhibited increased toxicity compared with the water exacts. Dust extracts from the laboratory exhibited the greatest bacterial toxicity when compared with office, dormitory and residence samples. Moreover, office dust exhibited higher bacterial toxicity than residence dust. Furthermore, the comprehensive toxicity of dust on PPT3 was assessed by extracts toxicity -addition (i.e. IRaddition). The calculated values were close to the corresponding experimental data. The bioluminescence test showed the indoor dust samples are weakly toxic to PPT3, which are equivalent to 0.046-0.123 mg Hg•L-1. Different dust extracts among the different sampling sites showed varying toxicity to PPT3. This study provides some important information to understand the potential health risk from different indoor environment using a rapid bioluminescence assay.

Strain effects on Co,N co-decorated graphyne catalysts for overall water splitting electrocatalysis.

Lattice strain, either tensile or compressive, can fine-tune the electronic structure of surfaces via altering the distances between surface atoms, thereby modifying the catalytic activity of catalysts. Numerous examples of strain engineering have been applied to various electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), but strain-optimized 2D carbon-based single-atom electrocatalysts for catalyzing the overall water splitting reaction have received little attention. Here, we applied the lattice strain of Co,N co-decorated graphyne (Co@N1-GY) to directly optimize its catalytic activity for the overall water splitting reaction based on first-principles calculations. Our calculations suggest that compressive strain and tensile strain lead to less stability of Co@N1-GY and the distances between C and Co atoms increase linearly with the strain changing from compressive to tensile, thus linearly upshifting the p-band center of C atoms and the d-band center of Co atoms. In addition, biaxial strain has more remarkable effects on these properties than uniaxial strain. From compressive to tensile strain, the chemisorption of electrochemically generated intermediates in both HER and OER becomes weaker and weaker. A tensile strain of 0.5% on Co@N1-GY gives an ideal HER performance, while the OER reaches the minimum overpotential of 0.33 V under the biaxial tensile strain of 3%.

Urinary concentration of personal care products and polycystic ovary syndrome: A case-control study.

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorder among females of reproductive age. Many emerging contaminants in personal care products have been confirmed with endocrine disruptive effects. We performed a case-control study to explore the association between the concentrations of certain emerging contaminants (organic UV filters, bisphenol A, and triclosan) and the risk of PCOS. Urine samples were collected from 40 women with PCOS (case group) and 83 healthy women (control group). No significant differences were found in detection rate or total concentrations of analytes in women with PCOS and controls (p > 0.05). In addition, no association was found between certain emerging contaminants and PCOS either in an unadjusted binary logistic regression model or in a model adjusted for potential confounders. However, with stratification according to body mass index, one organic UV filter - octocrylene(OC) was significantly associated with PCOS in women with BMI ≥ 24 (adjusted OR = 1.512, 95% CI: 1.043, 2.191). It's the first time to investigate the association between exposure of organic UV filters and PCOS risk. We conclude that there is positive association between OC and PCOS risk in obese and overweight women.

Synthesis of methanol from CO2 hydrogenation promoted by dissociative adsorption of hydrogen on a Ga3Ni5(221) surface.

Catalytic carbon dioxide (CO2) hydrogenation to liquid fuels including methanol (CH3OH) has attracted great attention in recent years. In this work, density functional theory (DFT) calculations have been employed to study the reaction mechanisms of CO2 hydrogenation to CH3OH on Ga3Ni5(221) surfaces. The results show that all intermediates except for the O atom prefer to adsorb on Ni sites, and dissociative adsorption of hydrogen (H2) on the Ga3Ni5(221) surface is almost barrierless and highly exothermic, favoring CO2 hydrogenation. Moreover, the presence of Ga indeed enhances the dissociative adsorption of H2, and this is verified by the projected density of states (PDOS) analysis. Importantly, three possible reaction pathways based on formate (HCOO) and hydrocarboxyl (COOH) formations and reverse water gas shift (rWGS) with carbon monoxide (CO) hydrogenation have been discussed. It is found that CO2 reduction to CH3OH in these pathways prefers to occur entirely via the Langmuir-Hinshelwood (L-H) mechanism. COOH generation is the most favorable pathway because the HCOO and rWGS with CO hydrogenation pathways have high energy barriers and the resulting HCOOH intermediate in the HCOO pathway is unstable. In the COOH reaction pathway, CO2 is firstly hydrogenated to trans-COOH, followed by the formation of COH via three isomers of COHOH, its hydrogenation to trans-HCOH, and then the production of CH3OH via a CH2OH intermediate.

Relationship between reaction rate constants of organic pollutants and their molecular descriptors during Fenton oxidation and in situ formed ferric-oxyhydroxides.

Fenton oxidation is a promising water treatment method to degrade organic pollutants. In this study, 30 different organic compounds were selected and their reaction rate constants (k) were determined for the Fenton oxidation process. Gaussian09 and Material Studio software sets were used to carry out calculations and obtain values of 10 different molecular descriptors for each studied compound. Ferric-oxyhydroxide coagulation experiments were conducted to determine the coagulation percentage. Based upon the adsorption capacity, all of the investigated organic compounds were divided into two groups (Group A and Group B). The percentage adsorption of organic compounds in Group A was less than 15% (wt./wt.) and that in the Group B was higher than 15% (wt./wt.). For Group A, removal of the compounds by oxidation was the dominant process while for Group B, removal by both oxidation and coagulation (as a synergistic process) took place. Results showed that the relationship between the rate constants (k values) and the molecular descriptors of Group A was more pronounced than for Group B compounds. For the oxidation-dominated process, EHOMO and Fukui indices (f(0)x, f(-)x, f(+)x) were the most significant factors. The influence of bond order was more significant for the synergistic process of oxidation and coagulation than for the oxidation-dominated process. The influences of all other molecular descriptors on the synergistic process were weaker than on the oxidation-dominated process.

The effect of nitrogen doping on mercury oxidation/chemical adsorption on the CuCo2O4(110) surface: a molecular-level description.

Based on density functional theory (DFT) calculations, the detailed mercury oxidation/chemical adsorption mechanisms on the N-doped CuCo2O4(110) surface are studied. The DFT calculations show that Ow (bonded with one Cu(2+) ion and one Co(3+) ion) is far more active than Os (bonded with three Co(3+) ions) and the mercury oxidation/chemical adsorption activation energy (Ea) on the virgin CuCo2O4(110) surface involving Ow is 0.85 eV. The physically adsorbed mercury overcomes the Ea and enters the energy well that plays an important role in mercury oxidation/chemical adsorption. Nitrogen doping can greatly increase the activity of Ow and decrease the activity of Os at the same time, which greatly affect the mercury oxidation/chemical adsorption abilities on the CuCo2O4(110) surface, and the Ea variation of mercury oxidation/chemical adsorption is as follows: 0.85 eV (virgin CuCo2O4(110)) → 0.76 eV (one N-doped CuCo2O4(110)) → 0.69 eV (two N-doped CuCo2O4(110)) → 0.48 eV (three N-doped CuCo2O4(110)). In addition, N-doping can decrease the adsorption energy of mercury and mercuric oxide. The effect of N-doping on the bonding mechanism of mercury adsorption on the CuCo2O4(110) surface is analyzed by the local density of state (LDOS) and the natural bonding orbital (NBO). The calculation results correspond well to the experimental data.

Temperature sensitivity of organic compound destruction in SCWO process.

To study the temperature sensitivity of the destruction of organic compounds in supercritical water oxidation process (SCWO), oxidation effects of twelve chemicals in supercritical water were investigated. The SCWO reaction rates of different compounds improved to varying degrees with the increase of temperature, so the highest slope of the temperature-effect curve (imax) was defined as the maximum ratio of removal ratio to working temperature. It is an important index to stand for the temperature sensitivity effect in SCWO. It was proven that the higher imax is, the more significant the effect of temperature on the SCWO effect is. Since the high-temperature area of SCWO equipment is subject to considerable damage from fatigue, the temperature is of great significance in SCWO equipment operation. Generally, most compounds (imax > 0.25) can be completely oxidized when the reactor temperature reaches 500°C. However, some compounds (imax > 0.25) need a higher temperature for complete oxidation, up to 560°C. To analyze the correlation coefficients between imax and various molecular descriptors, a quantum chemical method was used in this study. The structures of the twelve organic compounds were optimized by the Density Functional Theory B3LYP/6-311G method, as well as their quantum properties. It was shown that six molecular descriptors were negatively correlated to imax while other three descriptors were positively correlated to imax. Among them, dipole moment had the greatest effect on the oxidation thermodynamics of the twelve organic compounds. Once a correlation between molecular descriptors and imax is established, SCWO can be run at an appropriate temperature according to molecular structure.

A comprehensive assessment of superabsorbent resin produced using modified quinoa husk and coal fly ash - Preparation, characterization and application.

About 200 million tons of coal fly ash (CFA) is not effectively used in China every year. To enhance the utilization of biomass waste quinoa husk (QH) and solid waste CFA and reduce the preparation cost of superabsorbent resin (SAR), a low-cost, biodegradable modified quinoa husk-g-poly (acrylic acid)/coal fly ash superabsorbent resin (MQH-g-PAA/CFA SAR) was synthesized using modified quinoa husk (MQH), acrylic acid and CFA and used to improve the drought resistance and fertilizer conservation ability of soil. The surface morphology and performance of SAR were characterized by Fourier transform infrared (FTIR) spectrometry, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA), which provided evidence for improving the properties of SAR by grafting MQH and adding CFA. In addition, the synthesis conditions were studied and optimized, together with the contents of initiator, crosslinker, MQH, and CFA to acrylic acid as well as the neutralization degree of acrylic acid. After optimization, the optimum water absorbency of SAR in deionized water, tap water, and physiological saline was 1302, 356, and 91 g/g respectively. The swelling and water-retention mechanisms of SARs were analyzed by a dynamic model and the results were in good agreement with the experimental data. In the soil experiment, the addition of SAR improved the drought resistance ability of soil, and reduced the leaching loss of fertilizer in the soil (from 49.5 % to 36.7 %). Therefore, this material exhibits significant potential in the field of agriculture and offers a novel approach with economic benefit for the utilization of MQH and CFA.

Molecular insight into the enhanced performance of CALB toward PBDF degradation.

Poly(butylene diglycolate-co-furandicarboxylate) (PBDF) is a newly developed biodegradable copolyester. Candida antarctica lipase B (CALB) has been identified as an effective catalyst for PBDF degradation. The mechanism is elucidated using a combination of molecular dynamics simulations and quantum chemistry approaches. The findings unveil a four-step catalytic reaction pathway. Furthermore, bond analysis, charge and interaction analysis are conducted to gain a more comprehensive understanding of the PBDF degradation process. Additionally, through the introduction of single-point mutations to crucial residues in CALB's active sites, two mutants, T138I and D134I, are discovered to exhibit improved catalytic efficiency. These significant findings contribute to the advancement of our comprehension concerning the molecular mechanism of underlying copolyesters degradation, while also presenting a novel approach for expediting the degradation rate by the CALB enzyme modification.