Paraoxonase 1 (PON1) is an A-esterase calcium-dependent enzyme that is associated with high-density lipoprotein (HDL) and capable of hydrolyzing a wide variety of substrates, including organophosphate (OP) pesticides. The PON1 phenotype can be modulated by multiple internal and external factors, thereby affecting the catalytic capacity of the enzyme. The aim of this study was to evaluate factors that could modulate PON1 activity in a sample occupationally exposed to pesticides. A cross-sectional, descriptive, and analytical study was carried out with 240 workers. The participants were stratified according to their level of pesticide exposure as reference, moderate-exposure, and high-exposure groups. PON1 activities (arylesterase/AREase, CMPAase, and ssPONase (salt-stimulated)) were determined by spectrophotometry, and the Q192R and L55M PON1 genotypes by real-time PCR. The most frequent genotypes were heterozygous (QR) and homozygous (LL) for PON1Q192R and PON1L55M polymorphisms, respectively. The internal factors associated with the activity of PON1 were the PON1 genotypes (55 and 192) and biochemical parameters related to the lipid profile, in contrast, various external factors related to diet and harmful habits as well as with exposure to pesticides were associated with the activity of PON1. However, using a multivariate mixed ordinal regression model, we found a significant reduction of ssPONase activity in the high-exposure group compared with the reference group only in haplotypes QQLL and RRLL.

In this paper, a crosslinked carboxymethyl starch (CCMS) was prepared with corn starch as the raw material, epichlorohydrin as the crosslinking agent, and chloroacetic acid as the etherifying agent through a series of crosslinking, alkalization, and etherification reactions, respectively. Nano-TiO₂ was loaded onto the surface of the CCMS by the sol-gel method to obtain a TiO₂/CCMS composite. The TiO₂/CCMS composite was characterized by XPS, XRD, SEM, and BET. XPS showed that the surface chemical composition of the TiO₂/CCMS composite material contained titanium; XRD diffraction patterns indicated that the crystal form of the TiO₂/CCMS composite was a combination of the CCMS and anatase TiO₂. The surface morphology obtained by SEM showed that there were nano-TiO₂ particles on the surface of the CCMS. The specific surface area of the TiO₂/CCMS composite was larger than that of CCMS. The adsorption-photodegradation performance of the TiO₂/CCMS composite was also studied under UV irradiation, and the results showed that significant adsorption-photodegradation synergies occurred.

The correct image of Figure 4 is shown in this paper. The original article has been corrected. Fig. 4: Scree plot of heavy metals in sediments. The graph shown in upper right corner shows the concentration of principle components variables in a loading plot.

Green behavior is an important part of the study of green development. To promote green development, it is necessary to engage in further innovation on the basis of lessons from international advancements in green behavior. To clarify the spatial and temporal distribution characteristics of international researchers in the study of green behavior, the research focus, and the research frontiers, a visual analysis was performed on 22,114 articles cited in the SSCI and SCI-EXPANDED databases from 2000 to 2017. This analysis was based on bibliometrics and mapping knowledge domain (MKD) analysis with CiteSpace 5.3.R4, a scientific and technological text-mining and visualization software. The results show that international green behavior research has the following main characteristics. First, a positive correlation was found between the number of papers and time. Second, research is highly valued by researchers in the natural sciences, such as ecology. The USA is involved in major research efforts and maintains a high level of cooperation with other countries and regions. International cooperation among institutions needs to be strengthened. The co-cited journals are primarily academic journals in the natural sciences. Third, research hotspots mainly focus on the theory of planned behavior (TPB), consumers, attitudes, performance, and environment, all of which evolve according to the phase path of “germination-growth.” Fourth, the research frontier issues are largely related to management science and environmental science, and the research objects and methods will become increasingly complex and interdisciplinary over time.

The present study quantifies the levels of five trace elements (TEs) Zn, Cu, Ni, Pb, and Cd in the leaves and rhizomes of Cymodocea nodosa as well as the surficial sediments from three semi-enclosed coastal areas in Tunisia, in the south Mediterranean Sea. Samples were taken from the Bizerte and Ghar El Melh lagoons and from marina Cap Monastir. The TE ranking was found to be Zn > Cu > Pb > Ni > Cd in sediments and Zn > Cu = Ni = Pb = Cd in C. nodosa leaves and rhizomes. Except for Ni, levels of Zn, Cu, Pb, and Cd significantly differed between the sites. Translocation factors (TFs) were > 1 for all trace elements proving the high capacity of C. nodosa to accumulate TEs in its above-ground tissues. Results show that marina Cap Monastir’s meadow exhibits higher TFs than the Bizerte and Ghar El Melh lagoons. This can be due to the presence of the non-indigenous species Halophila stipulacea. The present study highlights the need for further investigation on the effect of interspecific interaction on TE uptake by seagrasses.

Phosphorus (P), an irreplaceable nutrient for all living organisms, is facing scarcity via phosphate resources. In this research, the effect of suitable additives and temperature on P and heavy metals speciation during sewage sludge (SS) thermochemical treatment was investigated. The results demonstrated that additives (CaO and MgO) could promote the conversion of non-apatite inorganic phosphorus (NAIP) to apatite phosphorus (AP). X-ray diffraction measurements indicated that the phosphorus mineral phase in sewage sludge ash (SSA) mainly was AP, with addition of MgO and CaO. Moreover, orthogonal testing revealed that the optimal molar ratio of Mg:Ca:P for P recovery as AP was 1:3.5:1 at 750 °C. Risk index results implied that the heavy metals in the phosphorus-enriched SSA have low potential ecological risk. Thermodynamic equilibrium calculations revealed that P reacted with the other metal ions was in the following order: Ca²⁺ > Mg²⁺ > Al³⁺ > Fe³⁺ > Zn²⁺ > K⁺. Graphical Abstract

This paper proposes a stress wave monitoring method for monitoring and locating leakage through the impervious layer at a landfill to resolve the “first pollution, then discovery” problem caused by the existing electrical monitoring method. The experimental results show that the linear distance to the geophones from the leak point should be less than 31.5 m to provide a well-defined rupture signal. The amplitudes of the stress wave signals generated during the yield and rupture stages of the high-density polyethylene (HDPE) film are more obvious and easily identified by the geophones; the rupture signal duration is approximately 100 ms, and the bandwidth is distributed within 0 kHz to 1 kHz. By studying the stress wave first arrival times calculated by the picking model, the average error of the picking model is approximately 0.35 ms, and the iteration of the model is ceased when the thresholds of the discriminating indices are 3.5 and 0.9. Experiments reveal that the positioning model should stop iterating when the absolute value of each element in the calibration vector is less than 140. The average positioning error is 0.248 m, and the maximum fiducial errors of the positioning model in the X-axis and Y-axis directions are 0.32% and 0.58%, respectively.

Intrusion of seawater into the coastal aquifers is a major concern as it affects the quality of groundwater. The objective of this study is to delineate the extent of seawater intrusion in the Indian coast based on previous studies and estimate the area as well as locations of seawater intrusion and submarine groundwater discharge based on the groundwater level of the years 2007 and 2017. Several researchers have reported seawater intrusion in the coastal regions of India by different methods of investigation. These studies indicate that the east coast of India is affected greater than the west coast by seawater intrusion. The maximum extent (about 14 km) of seawater intrusion in India is reported in regions north of Chennai. It is estimated that around 7% of the total coastal area is affected by seawater intrusion, where groundwater is below mean sea level. Around 57% of the coastal area of India has groundwater level in the range from 0 to 10 m msl. Future research needs to focus on the areas where seawater intrusion and submarine groundwater discharge were identified based on this study.

The influence of flue gas composition on the specific resistance of coal-fired fly ash is studied in this paper. We conclude that the negative electrons of NO₂ and SO₂ gases are strong. The probabilities of electron desorption on SO₂ and NO₂ negative ions are lower than that in air atmosphere at high temperature. Therefore, the introduction of SO₂ causes NO₂ to reduce the specific resistance value of coal-fired fly ash. When the pores on the surface of fly ash particles are filled with SO₂, no change will occur in NO₂, average pore size, pore volume, and specific surface area of fly ash particles, thereby resulting in fly ash that remains unchanged from the resistance value. When humidity increases, the surface conduction effect is greatly enhanced, and the specific resistance value is lowered considerably. Therefore, the specific resistance of dust can be reduced by humidification.

The widespread use of thiram has raised concerns for health and its toxic effects, but the underlying toxicity mechanism on platelets and bones is poorly defined. Here, we found a significant increase in the number of platelets in chickens with the thiram intake, due to the increased expression of thrombopoietin mRNA in the dysfunction liver. Furthermore, the decreased vascular distribution and cell death of chondrocytes in the tibial growth plates (TGPs) were observed, resulting in bone growth inhibition, which is associated with the abnormal activation of platelets leading to the extraordinary decrease of vascular endothelial growth factor A (VEGFA) and angiopoietin-1 protein were released and their corresponding receptors VEGFR2 and Tie-2 expressions were also reduced in the TGPs. Taken together, these findings revealed that thiram has an adverse effect on bones and platelets, which may have a high risk of thrombosis and osteoarthritis.