Effects of wood vinegar on properties and mechanism of heavy metal competitive adsorption on secondary fermentation based composts.

In this study, secondary municipal solid waste composts (SC) and wood vinegar treated secondary compost (WV-SC) was prepared to investigate the capability for single-heavy metals and multi-metal systems adsorption. The adsorption sequence of WV-SC for the maximum single metals sorption capacities was Cd (42.7mgg-1) > Cu (38.6mgg-1) > Zn (34.9mgg-1) > Ni (28.7mgg-1) and showed higher than that of SC adsorption isotherm. In binary/quaternary-metal systems, Ni adsorption showed a stronger inhibitory effect compared with Zn, Cd and Cu on both SC and WV-SC. According to Freundlich and Langmuir adsorption isotherm models, as well as desorption behaviors and speciation analysis of heavy metals, competitive adsorption behaviors were differed from single-metal adsorption. Especially, the three-dimensional simulation of competitive adsorption indicated that the Ni was easily exchanged and desorbed. The amount of exchangeable heavy metal fraction were in the lowest level for the metal-loaded adsorbents, composting treated by wood vinegar improved the adsorbed metals converted to the residue fraction. This was an essential start in estimating the multiple heavy metal adsorption behaviors of secondary composts, the results proved that wood vinegar was an effective additive to improve the composts quality and decrease the metal toxicity.

Retention and transport of PFOA and its fluorinated substitute, GenX, through water-saturated soil columns.

Perfluoro-2-propoxypropanoic acid (GenX) has emerged as a substitute for perfluorooctanoic acid (PFOA) especially since PFOA was listed among the persistent organic pollutants (POPs) by the Stockholm Convention in 2019. However, limited knowledge exists regarding the behavior and mobility of GenX in natural soils hindering the prediction of its environmental fate. This study investigated the mobility and retention of GenX and PFOA in soils under batch and water-saturated flow-through conditions. Batch experiments revealed that GenX has a lower binding affinity to soil than longer-chained PFOA, potentially threatening groundwater resources. Unlike metal-oxides/minerals (ferrihydrite, gibbsite and manganese dioxide), biochar (BC) and activated carbon (AC) amendments significantly enhanced the sorption of both GenX and PFOA in soil. Sorption data on minerals and carbonaceous materials implied that for shorter-chained GenX, the predominant mode of sorption was through electrostatic (ionic) interactions, while for longer-chained PFOA, hydrophobic interactions became progressively more important with increasing chain length. The dynamic flow experiments demonstrated that these soil amendments enhanced the retention of both compounds, thereby decreasing their mobility. Simultaneous injection of both compounds into columns pre-loaded with either PFOA or GenX increased their retardation. GenX sorption was more affected by pre-sorbed PFOA compared to the minimal impact of pre-loaded GenX on PFOA sorption. A newly developed reactive transport model, which incorporates a two-site sorption model and accounts for kinetic-limited processes, accurately predicted the sorption and transport of both compounds in single and binary contamination systems. These findings have important implications for predicting and assessing the fate and mobility of per- and polyfluoroalkyl substances (PFAS) in soils and groundwaters.

Characteristics and mechanisms of resorption in lumbar disc herniation.

Lumbar disc herniation (LDH) can be spontaneously absorbed without surgical treatment. However, the pathogenesis and physiological indications for predicting protrusion reabsorption are still unclear, which prevents clinicians from preferentially choosing conservative treatment options for LDH patients with reabsorption effects. The purpose of this review was to summarize previous reports on LDH reabsorption and to discuss the clinical and imaging features that favor natural absorption. We highlighted the biological mechanisms involved in the phenomenon of LDH reabsorption, including macrophage infiltration, inflammatory responses, matrix remodeling, and neovascularization. In addition, we summarized and discussed potential clinical treatments for promoting reabsorption. Current evidence suggests that macrophage regulation of inflammatory mediators, matrix metalloproteinases, and specific cytokines in intervertebral disc is essential for the spontaneous reabsorption of LDH.

Green waste compost as a substitute for turfy soil in external-soil spray seeding substrate.

The scarcity of turfy soil (TS), which is the most commonly used external-soil spray seeding (ESSS) substrate component, has recently increased. The aim of this study was to introduce a substitute for TS as an organic matter additive in substrate. Green waste compost (GWC) that was combined with sandy loam soil, polyacrylamide (PAM), and super absorbent polymer (SAP) was used for preparing the soil substrate. Further, a modified soil-spraying experiment and artificial rainfall experiments with an orthogonal design (L1643) were conducted. These experiments assessed the feasibility of GWC as a component of ESSS substrate and the optimal formulation. The results indicated that the degree of influence of the three factors controlling the amended substrate is GWC > PAM > SAP. GWC improved the physical and chemical properties of the substrate, as well as the seed germination rate and seedling growth. Significant improvements can be observed with respect to the soil bulk density, soil porosity, steady infiltration rate, and anti-shearing strength (p < .01). Additionally, the runoff and soil loss decreased under heavy rainfall. Except for the soil nutrients and seedling height, all other indicators of the GWC substrates were better than those of the commercially available TS substrates. Principal component analysis and range analysis revealed that the optimum values of various design parameters were 40% for the compost volume content, 200 g m-3 for PAM and 100 g m-3 for SAP. Based on these results, GWC can be considered to be an effective alternative to TS for ESSS.

Direct and efficient reduction of perfluorooctanoic acid using bimetallic catalyst supported on carbon.

A variety of metal elements have exhibited strong reductive and dehalogenative capabilities for the removal of persistent organic pollutants, owing to electron transfer or electron-hole activation through various methods. Herein, a bimetallic CNi-Al2O3 structure (AlCNi) was successfully synthesized to simultaneously function as sorbent and catalyst in the reduction of perfluoroalkyl carboxylic acids (PFOA) polluted wastewater. Using a reaction period of 3 h, 98% of PFOA was removed by AlCNi through a mechanochemical stirring method and 70.43% of fluorine ions was released from PFOA anchored onto the surface of AlCNi. Both thermocatalysis and photocatalysis technologies were incorporated and compared when utilized in tandem with AlCNi to mitigate the PFOA. In addition, peroxymonosulfate (PMS) and sodium sulfite (Na2SO3) were also integrated into experiments, separately, as a strong oxidant and reductant to improve the degradation effect of PFOA. However, the degradation efficiency of both were lower than that of AlCNi, even when assisted by elevated temperatures and ultraviolet irradiation. The feasibility of employing AlCNi for PFOA degradation was further investigated at various temperature and pH conditions. The data obtained from HPLC-MS/MS, TOC, and IC with multiple characterizations of AlCNi/PFOA, proposed the predominant degradation pathways comprising adsorption, defluorination-hydroxylation, and decarboxylation. This study provides a valuable remediation method without utilizing chemical agents and special activation for PFOA by AlCNi, which can be suitable for large-scale sewage treatment applications.

Comprehensive adsorption behavior and mechanism of PFOA and PFCs in various subsurface systems in China.

The adsorption-desorption performance of perfluorooctanoic acid (PFOA), one of the environmentally persistent pollutants which is refractory to degrade in soil, was investigated and reported. The adsorption-desorption process of PFOA was firstly conducted using different fractions (sand, coarse silt and fine silt) of soil collected from Shanghai, China. More than 50% of PFOA (2.0 mg/L) could be adsorbed by soils while only less than 10% of which could be desorbed once contamination occurs. The kinetics and particle diffusion rates of PFOA in different fractions of soil were calculated and analyzed in detail. Apart from this, the retention of short-chained PFCs, which can be generated as degradation products of PFOA, were also measured. In single solute systems, the adsorption of pollutants in soils dramatically increased as the chain length of PFCs grew longer. Similarly, in mixed solutions, preferential adsorption of longer-chained PFCs over shorter chains in soils were sited, attributable to the stronger hydrophobicity of the pollutants. However, the desorption of them performed in reverse, where the desorption rates of longer-chained PFCs were far lower than those of shorter ones. Furthermore, influencing factors including pH, temperature and co-existing matters were studied during the adsorption process. After comprehending the adsorption behavior of PFOA in soil fractions, the situation of the adsorption of PFOA in various soils chosen from nine provinces in China was investigated and compared. There was an obvious discrepancy, whether it be from the rate or the amount of adsorption of PFOA (approximately 10%), in the nine different soils. Finally, a multiple linear regressive equation was employed to sort influencing parameters which are prone to affect the adsorption of PFOA in soils, the contribution of these are provided in order of relevance. These results demonstrate the adsorption performance and behavior of PFOA and PFCs in different soils, which can be utilized as a scientific reference for maximizing remediation of PFOA polluted sites in the future.

[Analysis of related factors and evaluation of quality of life of osteonecrosis of femoral head after internal fixation of femoral neck fracture].

OBJECTIVE: To explore the risk factors of osteonecrosis of femoral head after internal fixation of femoral neck fracture in young patients, to describe the quality of life of patients with surviving femoral head, and to quantify the predictive factors. METHODS: From January 2013 to December 2016, 172 patients (174 hips) with femoral neck fracture treated by closed reduction and cannulated screw internal fixation were selected for retrospective analysis. The general data of the patients were summarized, including age, gender, body mass index, trauma mechanism, trauma operation interval, trauma season and whether the internal fixation was removed. The imaging data included the Garden classification and Pauwel classification of fractures, femoral head retroversion angle, postoperative fracture reduction, screw distribution. Single factor analysis and multi-factor Logistic regression analysis were carried out to explore the risk factors of femoral head necrosis and internal fixation failure. The patients who survived the internal fixation were followed up. The quality of life of the patients was evaluated by the health survey of SF-36. The Harris score of hip joint function was used to evaluate the hip joint function. The predictors of the quality of life of the patients after the operation of femoral neck fracture were analyzed by multiple linear regression analysis. RESULTS: Total 172 patients(174 hips) were included in the study, 29 patients(16.67%) had necrosis of the femoral head. In multivariate Logistic regression analysis, the significant differences were reduction quality (OR=0.126, P=0.027) and posterior inclination angle (OR=4.380, P=0.010). One hundred and thirty six patients (137 hips) who survived the femoral head were included in the quality of life survey. Harris score was 90.14±7.92, including excellent 96 hips (70.07%), good 28 hips (20.44%), medium 13 hips (9.49%) and poor 0 hip. In SF-36 score, physical health summary (PCS) was 46.12±9.12, mental health summary(MCS) was 50.21±3.97, there was no linear correlation between them (P>0.05). In multiple linear regression analysis, the variables with significant difference in PCS were reduction quality and retroversion angle, and the variables with significant difference in MCS were fracture displacement and trauma mechanism. CONCLUSION: Poor reduction quality and posterior inclination angle>15° are the risk factors of femoral head necrosis. The function of hip joint and MCS of patients with femoral neck fracture recovered well, but PCS could not recover to the average level of normal people. The reduction quality and retroversion angle could be used as the predictors of PCS, and the displacement and trauma mechanism of fracture could be used as the predictors of MCS.

In Vitro and In Vivo Evaluations of ß-Lactam/ß-Lactamase Mono- and Combined Therapies against Carbapenem-Nonsusceptible Enterobacteriaceae in Taiwan.

Increasing carbapenem resistance rates worldwide underscored the urgent need of novel antimicrobials. Ceftazidime-avibactam and aztreonam-avibactam combinations are developed to combat carbapenem resistance, but biological and geographic variations must be considered for antibiotic susceptibility patterns varied. Thus, we sought to assess the susceptibilities of ceftazidime-avibactam and aztreonam-avibactam against 660 carbapenem-nonsusceptible Enterobacteriaceae isolates (472 Klebsiella pneumoniae and 188 Escherichia coli) collected during an earlier Taiwan surveillance study. Agar dilution method was used to determine ceftazidime-avibactam and aztreonam-avibactam susceptibility. Metallo-carbapenemase's contribution to resistance were investigated with EDTA addition. The in vivo efficacies were evaluated using a Caenorhabditis elegans model. High susceptibility rates were observed for ceftazidime-avibactam and aztreonam-avibactam against the 472 carbapenem-nonsusceptible K. pneumoniae (CnsKP) (85.2% and 95.3%, respectively) and 188 carbapenem-nonsusceptible E. coli (CnsEC) isolates (91.5% and 94.1%, respectively). For non-metallo-carbapenemase producers, the susceptibility rates for ceftazidime-avibactam were 93.6% for CnsKP and 97.7% for CnsEC, whereas only 7.1% CnsKP and 11.1% CnsEC in metallo-carbapenemase producers were susceptible to ceftazidime-avibactam. Of all isolates, 95.3% CnsKP and 94.1% CnsEC were susceptible to aztreonam-avibactam. In C. elegans model, ceftazidime-avibactam and aztreonam-avibactam revealed effective against a blaKPC-producing K. pneumoniae isolate in vivo. Our results propose a positive therapeutic approach for both combinations against carbapenem-nonsusceptible Enterobacteriaceae in Taiwan.

[Clinical observation of Yishen Huoxue decoction(YSHXD) for the treatment of non-traumatic osteonecrosis of femoral head at early and middle stage].

OBJECTIVE: To observe clinical efficacy of Yishen Huoxue decoction(YSHXD) for the treatment of non-traumatic osteonecrosis of femoral head at early and middle stage. METHODS: From January to June 2016, 69 patients (72 hips) with non-traumatic osteonecrosis of femoral head at early and middle stage were divided into treatment group and control group according to therapeutic methods. In treatment group, there were 35 patients 43 hips, including 15 males and 20 females, aged from 28 to 62 years old with an average of(41.80±11.03) years old, 6 hips were at the stage I, 27 hips were at the stageII, 10 hips were at the stage IIIa according to ARCO classification; and treated by using YSHXD, one dose a day for 12 months. In control group, there were 34 patients 39 hips, including 16 males and 18 females, aged from 31 to 61 years old with an average of (43.35±13.52) years old, 5 hips were at the stage I, 26 hips were at the stageII, 8 hips were at the stage IIIa according to ARCO classification; and treated by using alendronate sodium tablets 70 mg every week for 12 months. Preoperative and postoperative HSS score at 2 weeks were observed and compared, EQ-5D index was used to compare clinical effects. ARCO classification was applied to imaging evaluation, the stage of ARCO over IIIa was considered as end point of observation. The final following-up time and ARCO classification were recorded and performed Kaplan-Meier survival analysis. RESULTS: All patients were followed-up from 26 to 76 months with an average of(43.50±13.26) months. Postoperative Harris score at 2 years in treatment group (84.92±7.56) was higher than that of before treatment (73.58±10.02) (P<0.05), and higher than that of control group(79.61±10.92)(P<0.05), especially the scores of joint function and activity were higher than those of control group(P<0.05). EQ-5D index in treatment group 0.66±0.12 was higher than that of control group 0.59±0.12(P<0.05). Nine hips were collapsed in treatment group at final follow-up, and 10 hips were collapsed in control group, and had no statistical difference between two groups (P>0.05). There was no statistical difference in kaplan-meier survival analysis curves between two groups (P>0.05). There were statistical difference in survival rate between the early, middle ARCO stage and different Harris evaluation. CONCLUSIONS: YSHXD for the treatment of non-traumatic osteonecrosis of femoral head at early and middle stage has obviously clinical effects, could improve hip joint function, and quality of life, and delay the process of femoral head necrosis collapse.

Efficient novel amphiphilic double shells layer coupled with nanoscale zero-valent composite for the degradation of trichloroethylene.

An efficient novel amphiphilic material composed of core-double shells nanocomposite (CDSN) with nanoscale zero-valent iron (NZVI) as the core and PS100-b-PAA16 as inner shell and chitosan as outmost shell has been synthesized successfully. Its application to remove the trichloroethylene (TCE) in stimulated TCE solution with 7.3 ±â€¯0.3 mg/L dissolved oxygen was investigated. The results showed that CDSN after exposure to air for a month could still remove 92.6% of TCE as compared to 61.5% removal rate of NZVI in 360 min (the gram ratio of material: TCE equals to 10:1), exhibiting the great oxidation resistance performance. Specifically, dynamic research of the total removal divided into adsorption by shell layer and degradation by reducibility of NZVI at a predetermined interval was engaged to understand the complete mass transfer process of TCE. The results revealed that CDSN adsorbed 1.5 to 2 folds time TCE as compared to NZVI in the same initial pH = 8.5 aqueous solution. Importantly, CDSN could sustain fixed reactivity to remove about 94.8% of TCE from the start to end. NZVI exhibited greater removal capacity in first 180 min, but later it lost the reducibility and finial removal rate was 89%. The selective adsorption to protonated CDSN was strengthened to increase the removal of TCE at pH 3.5 while NZVI had a worse removal in pH 3.5 performance than pH 8.5.

A novel fluorescent probe (dtpa-bis(cytosine)) for detection of Eu(III) in rare earth metal ions.

In this paper, a novel fluorescent probe, dtpa-bis(cytosine), was designed and synthesized for detecting europium (Eu3+) ion. Upon addition of Eu3+ ions into the dtpa-bis(cytosine) solution, the fluorescence intensity can strongly be enhanced. Conversely, adding other rare earth metal ions, such as Y3+, Ce3+, Pr3+, Nd3+, Sm3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Yb3+ and Lu3+, into dtpa-bis(cytosine) solution, the fluorescence intensity is decreased slightly. Some parameters affecting the fluorescence intensity of dtpa-bis(cytosine) solution in the presence of Eu3+ ions were investigated, including solution pH value, Eu3+ ion concentration and interfering substances. The detection mechanism of Eu3+ ion using dtpa-bis(cytosine) as fluorescent probe was proposed. Under optimum conditions, the fluorescence emission intensities of EuIII-dtpa-bis(cytosine) at 375nm in the concentration range of 0.50×10-5mol∙L-1-5.00×10-5mol∙L-1 of Eu3+ ion display a better linear relationship. The limit of detection (LOD) was determined as 8.65×10-7mol∙L-1 and the corresponding correlation coefficient (R2) of the linear equation is 0.9807. It is wished that the proposed method could be applied for sensitively and selectively detecting Eu3+ ion.

Design and synthesis of a novel lanthanide fluorescent probe (TbIII-dtpa-bis(2,6-diaminopurine)) and its application to the detection of uric acid in urine sample.

In this study, a novel fluorescent probe, TbIII-dtpa-bis(2,6-diaminopurine) (Tb-dtpa-bdap), is designed based on the principle of complementary base pairing and synthesized for uric acid detection. The synthesized fluorescent probe is characterized by 1H NMR, 13C NMR, infra-red (IR) spectrum and ultraviolet-visible (UV-vis) spectra. It is found that the fluorescence of Tb-dtpa-bdap solution can be quenched obviously in the presence of uric acid. The affecting factors, including solution acidity, uric acid concentration and interfering substances, on the detection of uric acid using this probe are examined. Under optimized conditions, the fluorescence intensities of Tb-dtpa-bdap solution towards different uric acid concentrations show a linear response in the range from 1.00 × 10-5 mol·L-1 to 5.00 × 10-5 mol·L-1 with a linear correlation coefficient (R2) of 0.9877. And the obtained limit of detection (LOD) is about 5.80 × 10-6 mol·L-1, which is lower than the level of uric acid in actual urine. The mechanism on the detection of uric acid by using Tb-dtpa-bdap is inferred from the experimental results. The facts demonstrate that the proposed fluorescent probe can be successfully applied for the determination of uric acid in human urine samples.