Total Content Research Articles

Are Geotextiles Silent Contributors of Ultrashort Chain PFASs to the Environment?

We investigated the presence of per- and poly fluoroalkyl substances (PFASs) in woven and nonwoven polypropylene geotextiles and four nonwoven polyester geotextiles commonly used in modern geosynthetic composite lining systems for waste containment facilities such as landfills. Targeted analysis for 23 environmentally significant PFAS molecules and methods for examining "PFAS total" concentrations were utilized to assess their occurrence in geotextiles. This analysis showed that most geotextile specimens evaluated in the current investigation contained the ultrashort chain PFAS compound pentafluoropropionic acid (PFPrA). While the concentrations ranged from nondetectable to 10.84 μg/g, the average measured concentrations of PFPrA were higher in polypropylene than in polyester geotextiles. "PFAS total" parameters comprising total fluorine (TF) and total oxidizable precursors (TOPs) indicate that no significant precursor mass nor untargeted intermediates were present in geotextiles. Therefore, this study identified geotextiles as a possible source of ultrashort PFASs in engineered lined waste containment facilities, which may contribute to the overall PFAS total concentrations in leachates or liquors they are in contact with. The findings reported for the first time herein may lead to further implications on the fate and migration of PFASs in geosynthetic composite liners, as previously unidentified concentrations, particularly of ultrashort-chain PFASs, may impact the extent of PFAS migration through and attenuation by constituents of geosynthetic composite liner systems. Given the widespread use of geotextiles in various engineering activities, these findings may have other unknown impacts. The significance of these findings needs to be further elucidated by more extensive studies with larger geotextile sample sizes to allow broader, generalized conclusions to be drawn.

Exploration of the Lipid Profile of Edible Oleaginous Microgreens by Mass Spectrometry-Based Lipidomics.

The spreading awareness of the health benefits associated with the consumption of plant-based foods is fueling the market of innovative vegetable products, including microgreens, recognized as a promising source of bioactive compounds. To evaluate the potential of oleaginous plant microgreens as a source of bioactive fatty acids, gas chromatography-mass spectrometry was exploited to characterize the total fatty acid content of five microgreens, namely, chia, flax, soy, sunflower, and rapeseed (canola). Chia and flax microgreens appeared as interesting sources of α-linolenic acid (ALA), with total concentrations of 2.6 and 2.9 g/100 g of dried weight (DW), respectively. Based on these amounts, approximately 15% of the ALA daily intake recommended by the European Food Safety Authority can be provided by 100 g of the corresponding fresh products. Flow injection analysis with high-resolution Fourier transform single and tandem mass spectrometry enabled a semi-quantitative profiling of triacylglycerols (TGs) and sterol esters (SEs) in the examined microgreen crops, confirming their role as additional sources of fatty acids like ALA and linoleic acid (LA), along with glycerophospholipids. The highest amounts of TGs and SEs were observed in rapeseed and sunflower microgreens (ca. 50 and 4-5 μmol/g of DW, respectively), followed by flax (ca. 20 and 3 μmol/g DW). TG 54:9, 54:8, and 54:7 prevailed in the case of flax and chia, whereas TG 54:3, 54:4, and 54:5 were the most abundant TGs in the case of rapeseed. β-Sitosteryl linoleate and linolenate were generally prevailing in the SE profiles, although campesteryl oleate, linoleate, and linolenate exhibited a comparable amount in the case of rapeseed microgreens.

Folate and Synthetic Folic Acid Content in Canadian Fortified Foods Two Decades After Mandatory Fortification.

In 1998, Health Canada mandated folic acid fortification of white flour and enriched grain products to prevent neural tube defects. At the time, neither the Canadian Nutrient File (CNF) nor product labels reflected the actual folate content of foods. We aimed to assess if 20 years post-fortification, the CNF values for total folate and synthetic folic acid accurately reflect amounts determined by direct analysis. Using the 2001 Food Expenditure Survey and ACNielsen Company data, we identified 10 to 15 of the most purchased fortified foods across 7 food categories in Canada. Total folate concentrations were determined by tri-enzyme digestion and microbial assay. Folic acid concentrations were determined using liquid chromatography tandem mass spectrometry. Except for "cooked pastas", mean total folate content of foods (n=89) were significantly higher than CNF values across categories (p<0.05), reflecting 167% ± 54 of CNF values. Similarly, mean folic acid content of foods was higher than CNF values for all categories except "cooked pastas" (p<0.05), with a mean of 188% ± 94 of CNF values; the latter CNF values included uncooked pasta. In sum, 20 years post-fortification, and 10 years since the last direct measurement, CNF and product label values still underestimate actual total folate and the folic acid content of foods. These findings emphasize that dietary estimates established using the CNF may significantly underestimate actual intakes and thus caution should be exercised when interpreting estimates of nutritional adequacy based on these values.

Machine learning and metagenomics identifies uncharacterized taxa inferred to drive biogeochemical cycles in a subtropical hypereutrophic estuary

Abstract Anthropogenic influences have drastically increased nutrient concentrations in many estuaries globally, and microbial communities have adapted to the resulting hypereutrophic ecosystems. However, our knowledge of the dominant microbial taxa and their potential functions in these ecosystems has remained sparse. Here, we study prokaryotic community dynamics in a temporal–spatial dataset, from a subtropical hypereutrophic estuary. Screening 54 water samples across brackish to marine sites revealed that nutrient concentrations and salinity best explained spatial community variations, whereas temperature and dissolved oxygen likely drive seasonal shifts. By combining short and long read sequencing data, we recovered 2459 metagenome-assembled genomes (MAGs), proposed new taxon names for previously uncharacterised lineages, and created an extensive, habitat specific genome reference database. Community profiling based on this genome reference database revealed a diverse prokaryotic community comprising 61 bacterial and 18 archaeal phyla, and resulted in an improved taxonomic resolution at lower ranks down to genus level. We found that the vast majority (61 out of 73) of abundant genus level taxa (&amp;gt;1% average) represented unnamed and novel lineages, and that all genera could be clearly separated into brackish and marine ecotypes with inferred habitat specific functions. Applying supervised machine learning and metabolic reconstruction, we identified several microbial indicator taxa responding directly or indirectly to elevated nitrate and total phosphorus concentrations. In conclusion, our analysis highlights the importance of improved taxonomic resolution, sheds light on the role of previously uncharacterised lineages in estuarine nutrient cycling, and identifies microbial indicators for nutrient levels crucial in estuary health assessments.

Effect of polymer concentration and cross-linking density on the microstructure and properties of polyimide aerogels

AbstractPolyimide aerogels display excellent mechanical strength, high thermal stability, low thermal conductivity, and outstanding dielectric properties. Typically, the synthesis of polyimide aerogels involves the polycondensation of dianhydride and diamine into poly(amic acid) (PAA) oligomers, which are then cross-linked and chemically imidized into polyimide. The stoichiometry of dianhydride and diamine determines the number of repeat units and length of the PAA oligomers, which in turn determines the cross-linking density. Despite the critical role of polymer concentration and number of repeating units in determining the microstructure and properties of polyimide aerogels, few detailed studies exist on these two parameters. Here, we synthesized and characterized 16 polyimide aerogel formulations from the common monomers biphenyl-3,3′,4,4′-tetracarboxylic dianhydride (BPDA) and 4,4′-oxydianiline (ODA), with different repeat units (n = 5, 15, 30, 45) and total polymer concentrations (4, 7, 10, 13 wt%). An increased polymer concentration accelerated gelation and enhanced the mechanical performance of aerogels, but surprisingly, it also led to higher volumetric shrinkage during aging, solvent exchange, and supercritical drying (SCD). Specific surface areas (SSAs) reached a maximum at intermediate polymer concentrations. A shorter oligomer chain length, i.e., a higher cross-linking density, led to moderately higher SSAs (between 320 and 400 m2/g) and reduced shrinkage, resulting in lower densities for a given polymer concentration. The density dependence of the thermal conductivity exhibits a pronounced U-shaped curve with a minimum in thermal conductivity of 21–23 mW/(m·K) between 0.080 and 0.120 g/cm3, with somewhat lower values for more highly cross-linked aerogels. This systematic study of polyimide aerogels forms the basis for designing polyimide aerogels with tailored properties for targeted applications. Graphical Abstract

Effect of particle size on liver MRI relaxometry: Monte Carlo simulation and phantom studies.

To investigate the effect of particle size on liver by Monte Carlo simulation and phantom studies at both 1.5 T and 3.0 T. Two kinds of particles (i.e., iron sphere and fat droplet) with varying sizes were considered separately in simulation and phantom studies. MRI signals were synthesized and analyzed for predicting , based on simulations by incorporating virtual liver model, particle distribution, magnetic field generation, and proton movement into phase accrual. In the phantom study, iron-water and fat-water phantoms were constructed, and each phantom contained 15 separate vials with combinations of five particle concentrations and three particle sizes. measurements in the phantom were made at both 1.5 T and 3.0 T. Finally, differences in predictions or measurements were evaluated across varying particle sizes. In the simulation study, strong linear and positively correlated relationships were observed between predictions and particle concentrations across varying particle sizes and magnetic field strengths ( ). The relationships were affected by iron sphere size ( ), where smaller iron sphere size yielded higher predicted , whereas fat droplet size had no effect on predictions ( ) for constant total fat concentration. Similarly, the phantom study showed that measurements were relatively sensitive to iron sphere size ( ) unlike fat droplet size ( ). Liver is affected by iron sphere size, but is relatively unaffected by fat droplet size. These findings may lead to an improved understanding of the underlying mechanisms of relaxometry in vivo, and enable improved quantitative MRI phantom design.

Efficient Removal of Water Soluble Fraction of Diesel Oil by Biochar Sorption Supported by Microbiological Degradation

The contamination of the water bodies by diesel oil (DO) and its water-soluble fraction (WSF) represents one of the most challenging tasks in the management of polluted water streams. This paper contains data related to the synthesis and characteristics of the plum stone biochar material (PmS-B), which was made from waste plum stones (PmS), along with its possible application in the sorption of the WSF of DO from contaminated water. Techniques applied in sample characterisation and comparisons were: Elemental Organic Analysis (EOA), Scanning Electron Microscopy−Energy Dispersive X-ray Spectroscopy (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), pH (pHsus) and point of zero charge (pHpzc). In order to increase the overall efficiency of the removal process, sorption and bioremediation were subsequently combined. Firstly, PmS-B was used as a sorbent of WSF, and then the remaining solution was additionally treated with a specific consortium of microorganisms. After the first treatment phase, the initial concentration of diesel WSF was reduced by more than 90%, where most of the aromatic components of DO were removed by sorption. The sorption equilibrium results were best fitted by the Sips isotherm model, where the maximum sorption capacity was found to be 40.72 mg/g. The rest of the hydrocarbon components that remained in the solution were further subjected to the biodegradation process by a consortium of microorganisms. Microbial degradation lasted 19 days and reduced the total diesel WSF concentration to 0.46 mg/L. In order to confirm the non-toxicity of the water sample after this two-stage treatment, eco-toxicity tests based on a microbial biosensor (Aliivibrio fischeri) were applied, confirming the high efficiency of the proposed method.

Pollution characteristics and risk assessment of organophosphate esters (OPEs) in typical industrial parks in Southwest China.

As alternative substances of PBDEs, organophosphate esters (OPEs), an emerging organic pollutant, were increasingly produced and used in many kinds of industries and consumer products. However, OPEs also have various adverse toxic effects. Information on the pollution levels and exposure to OPEs in related industries is still limited. This study presented data on OPE contamination in the soil, leaf, and river water samples from seven typical industrial parks in Southwest China. Total concentration of seven OPEs (Σ7OPE) including tri-n-butyl phosphate (TnBP), tris-(2-ethylhexyl) phosphate (TEHP), tris-(2-butoxyethyl) phosphate (TBEP), tris-(2-carboxyethyl) phosphine (TCEP), triphenyl phosphate (TPhP), tris-(1,3-dichloro-2-propyl) ester (TDCPP), and tris-(chlorisopropyl) phosphate (TCPP) in the soil samples (36.2 ~ 219.7 ng/g) and the surrounding river water samples (118.9 ~ 287.7 ng/L) were mostly lower than those in other studies, while the Σ7OPE level in the leaves (2053.3 ~ 8152.7 ng/g) was relatively high. There were significant differences in the concentration and distribution of OPEs in the surrounding environment of different industrial parks. TDCPP, TnBP, and TCPP could be used as the characteristic compound in soil samples from auto industrial park, river samples from shoe making industrial park, and leaf samples from logistics park, respectively. The parameter m (the content ratio of chlorinated OPEs to alkyl OPEs) was suggested to distinguish the types of industrial park preliminary. When m ≥ 1, it mainly refers to heavy industries sources such as automobiles, electronics, and machinery, etc. When m<1, it mainly for the light industrial sources such as textile industry, transportation services, and resources processing, etc. For logistics park, furniture park and Wuhou comprehensive industrial park, the volatilization of materials was the main sources of OPEs in the surrounding environment, while more effort was required to strengthen the pollution control and management of the waste water and soil in the pharmacy industrial park, shoe making industrial park and auto industrial park. Risk assessment showed that there was a negligible non-cancer and carcinogenic risk in the soil, while high attention should be paid to the non-cancer risk for children.

Dietary fatty acids modulate oxidative stress response to air pollution but not to infection

Anthropogenic changes to the environment expose wildlife to many pollutants. Among these, tropospheric ozone is of global concern and a highly potent pro-oxidant. In addition, human activities include several other implications for wildlife, e.g., changed food availability and changed distribution of pathogens in cities. These co-occurring habitat changes may interact, thereby modulating the physiological responses and costs related to anthropogenic change. For instance, many food items associated with humans (e.g., food waste and feeders for wild birds) contain relatively more ω6-than ω3-polyunsaturated fatty acids (PUFAs). Metabolites derived from ω6-PUFAs can enhance inflammation and oxidative stress towards a stimulus, whereas the opposite response is linked to ω3-derived metabolites. Hence, we hypothesized that differential intake of ω6-and ω3-PUFAs modulates the oxidative stress state of birds and thereby affects the responses towards pro-oxidants. To test this, we manipulated dietary ω6:ω3 ratios and ozone levels in a full-factorial experiment using captive zebra finches (Taeniopygia guttata). Additionally, we simulated an infection, thereby also triggering the immune system’s adaptive pro-oxidant release (i.e., oxidative burst), by injecting lipopolysaccharide. Under normal air conditions, the ω3-diet birds had a lower antioxidant ratio (GSH/GSSG ratio) compared to the ω6-diet birds. When exposed to ozone, however, the diet effect disappeared. Instead, ozone exposure overall reduced the total concentration of the key antioxidant glutathione (tGSH). Moreover, the birds on the ω6-rich diet had an overall higher antioxidant capacity (OXY) compared to birds fed a ω3-rich diet. Interestingly, only the immune challenge increased oxidative damage, suggesting the oxidative burst of the immune system overrides the other pro-oxidative processes, including diet. Taken together, our results show that ozone, dietary PUFAs, and infection all affect the redox-system, but in different ways, suggesting that the underlying responses are decoupled despite that they all increase pro-oxidant exposure or generation. Despite lack of apparent cumulative effect in the independent biomarkers, the combined single effects could together reduce overall cellular functioning and efficiency over time in wild birds exposed to pathogens, ozone, and anthropogenic food sources.

Microplastics and Endocrine Disruptors in Typical Wastewater Treatment Plants in Megacity Shanghai

The fast development of China’s urbanization has led to a notable release of emerging pollutants, including microplastics (MPs) and endocrine disruptors (EDCs). Generally, these pollutants enter the coastal environment through the discharge of wastewater treatment plants (WWTPs) and finally threaten the organisms in the receiving waterbody. The study investigated the environmental behavior of MPs and EDCs in two typical WWTPs in one of the megacities in China, Shanghai. The abundance of MPs in the influent ranged from 321 to 976 items/L. Four shapes (films, fragments, fibers, and microbead) were found, while fibers and films dominated. Transparent (31–63%) and white (20–47%) MPs were more frequently observed, while polyethylene terephthalate, cellulose, and cellophane were the main polymetric materials. The size of the MPs fell between 15.8 μm and 2220 μm, and the smaller one (&lt;500 μm) dominated. The removal efficiencies of the two WWTPs for MPs ranged from 64% to 92%, and both WWTPs performed better for large pieces of MPs (&gt;500 μm). For EDCs, total concentrations in the influent were detected, ranging from 113 to 2780 ng/L. Two groups, including phenolic estrogens (PEs) and steroid estrogens (SEs), were detected, and PEs, especially bisphenol A (BPA), were the predominant individuals among the studied EDCs. Specifically, PEs ranged from 82.8 to 2637 ng/L, while SEs ranged from 27.3 to 143 ng/L. The removal efficiencies of the WWTPs for EDCs varied (82.8–100%) as well, possibly due to the different treatment compartments and contamination load in the influent. Seasonal variations for both MPs and EDCs were observed. Specifically, concentrations of MPs and EDCs in WWTPs influent were higher in the wet season, as well as the removal efficiency. Furthermore, there was a correlation observed between the concentrations of MPs and EDCs, suggesting that MPs and EDCs may originate from the same source and that EDCs released by MPs cannot be ignored during treatment. Finally, the study evaluated the environmental risk of the effluents. MPs led to a minor risk (Level I), while EDCs might lead to an adverse impact on algae (RQs = 0.0014–0.024) and fish (RQs = 3.4–30.2). In summary, WWTPs received considerable amounts of MPs and EDCs. Although the WWTPs removed the contaminants efficiently, the environmental risk of the effluent needs to be noted.

[Effects of Pesticides Use on Pesticides Residues and Its Environmental Risk Assessment in Xingkai Lake（China）].

Xingkai Lake, located in Heilongjiang Province, is an important fishery and agricultural base and is seriously polluted by agricultural non-point sources. To clarify the residual status of many pesticides in the surface water of Xingkai Lake, 27 types of pesticides, herbicides, and their degradation products were analyzed in rice paddy, drainage, and surface water around Xingkai Lake (China) during the rice heading and maturity periods. The results showed that all 27 types of pesticides, herbicides, and their degradation products were detected during the rice heading period, and the total concentration ranged from 247.97 to 6 094.49 ng·L-1. Additionally, 25 species were detected during the rice maturity period, and the total concentration ranged from 485.36 to 796.23 ng·L-1. In comparison, more pesticides, herbicides, and derived degradation products were detected during the heading period, and their total concentration was higher as well. During the rice heading period, atrazine, simetryn, and paclobutrazol were the main detected pesticides, atrazine and isoprothiolane were the main pesticides detected during the maturity period. The distribution characteristics of pesticides and herbicides in the surface water around Xingkai Lake (China) was similar to that in drainage, so they were probably imported from the drainage and rice paddy. The average risk quotient (RQ) values of atrazine, simetryn, prometryn, butachlor, isoprothiolane, and oxadiazon were higher than 0.1 in drainage and Xingkai Lake (China), which showed a potential risk to aquatic organisms.

Longitudinal in vivo cationic contrast-enhanced computed tomography classifies equine articular cartilage injury and repair.

Cationic contrast-enhanced computed tomography (CECT) capitalizes on increased contrast agent affinity to the charged proteoglycans in articular cartilage matrix to provide quantitative assessment of proteoglycan content with enhanced images. While high resolution microCT has demonstrated success, we investigate cationic CECT use in longitudinal in vivo imaging at clinical resolution. We hypothesize that repeated administration of CA4+ will have no adverse side effects or complications, and that sequential in vivo imaging assessments will distinguish articular cartilage repair tissue from early degenerative and healthy cartilage in critically sized chondral defects. In an established equine translational preclinical model, lameness and synovial effusion scores are similar to controls after repeated injections of CA4+ (eight injections over 16 weeks) compared to controls. Synovial fluid total protein, leukocyte concentration, and sGAG and PGE2 concentrations and articular cartilage and synovial membrane scores are also equivalent to controls. Longitudinal in vivo cationic CECT attenuation in repair tissue is significantly lower than peripheral to (adjacent) and distantly from defects (remote sites) by 4 weeks (p < 0.001), and this difference persists until 16 weeks. At the 6- and 8-week time points, the adjacent locations exhibit significantly lower cationic CECT attenuation compared with the remote sites, reflecting peri-defect degeneration (p < 0.01). Cationic CECT attenuation at clinical resolution significantly correlates with cationic CECT (microCT) (r = 0.69, p < 0.0001), sGAG (r = 0.48, p < 0.0001), and ICRS II histology score (r = 0.63, p < 0.0001). In vivo cationic CECT imaging at clinical resolution distinguishes fibrous repair tissue from degenerative and healthy hyaline cartilage and correlates with molecular tissue properties of articular cartilage.

Enhanced Production of Erythritol from Glucose by the Newly Obtained UV Mutant Yarrowia lipolytica K1UV15

Erythritol is a polyol with a sweet taste but low energy value. Thanks to its valuable properties, as well as growing social awareness and nutritional trends, its popularity is growing rapidly. The aim of this study was to increase the effectiveness of erythritol production from glucose using new UV mutants of the yeast Yarrowia lipolytica obtained in the Wratislavia K1 strain. The ability of the new strains to biosynthesize erythritol and utilize this polyol was examined in shake-flask cultures and fed-batch processes conducted in a stirred tank reactor with a total glucose concentration of 300 and 400 g/L. The Wratislavia K1 strain produced erythritol most efficiently (97.5 g/L; 192 h) at an initial glucose concentration of 250 g/L (total: 300 g/L). New strains were assessed under such conditions, and it was noted that the highest erythritol concentration (145 g/L; 183 h) was produced by the K1UV15 strain. A significant improvement in the erythritol biosynthesis efficiency (148 g/L; 150 h) was achieved upon the increase in (NH4)2SO4 to 3.6 g/L. Further, in the culture with such a concentration of the nitrogen source and increased total glucose level (400 g/L), the K1UV15 strain produced 226 g/L of erythritol within 281 h.

Isolation of the Antifungal Compound Alliodorin from the Heartwood of Cordia elaeagnoides A. DC. and the In Silico Analysis of the Laccase

Cordia elaeagnoides A. DC. is an endemic species of Mexico valued for its timber. Renowned for its durability, resistance, and versatile applications in medicine, this tree holds significant commercial importance. Tetrahydrofuran (THF) extract from the heartwood of C. elaeagnoides was studied. Through chromatographic column purification, the compound 8-(2,5-Dihydroxyphenyl)-2,6-dimethylocta-2,6-dienal, also known as alliodorin, was successfully isolated. Identification of alliodorin was confirmed through comprehensive analysis utilizing NMR, IR, and mass spectrometry techniques. Inhibition tests were conducted using both the THF extract and alliodorin against the rotting fungus Trametes versicolor (L.) Lloyd, employing the agar well diffusion assay. Remarkably, alliodorin exhibited 100% inhibition with a median lethal concentration of 0.079 mg/mL and a total lethal concentration of 0.127 mg/mL, in comparison to the commercial fungicide benomyl, which requires a concentration of 1 mg/mL. In silico analysis through molecular docking on the laccase enzyme was proposed in order to explain the inhibitory activity against the fungus T. versicolor, as this enzyme is one of the main sources of nutrients and development for the fungus. Based on these findings, we deduced that alliodorin holds promise as a potent antifungal agent, potentially applicable in a wide array of technological and environmentally friendly initiatives.

[Pollution Characteristics, Source, and Health Risk Assessment of Metal Elements in PM2.5 Between Winter and Spring in Zhengzhou].

A total of 18 metal elements in ambient PM2.5 in Zhengzhou were continuously determined using an online heavy metal observation instrument in January and April, 2021, and the changes in element concentrations were analyzed. Metal elements were traced via enrichment factors, positive matrix factorization (PMF), and a characteristic radar chart. The US EPA health risk assessment model was used to assess the health risks of heavy metals, and the backward trajectory method and the concentration-weighted trajectory (CWT) method were used to evaluate the potential source regions of health risks. The results showed that the element concentrations were higher in spring, and the sum of Fe, Ca, Si, and Al concentrations accounted for 89.8% and 87.5% of the total element concentrations in winter and spring, respectively. Cd was enriched significantly, which was related to human activities. The concentrations of Pb, Se, Zn, Ni, Sb, and K in winter and Cr, Ni, Fe, Mn, V, Ba, Ca, K, Si, and Al in spring increased with the increasing pollution level. The results of PMF and the characteristic radar chart showed that the main sources of metal elements in winter and spring were industry, crust, motor vehicles, and mixed combustion, with industry and mixed combustion pollution occurring more often in winter and crust pollution occurring more often in spring. Significant non-carcinogenic risks existed in both winter and spring with more severe health risks in winter, and Mn caused significant non-carcinogenic risks. The health risks in winter were mainly influenced by Zhengzhou and surrounding cities and long-distance transport in the northwest, and the health risks in spring were mainly influenced by Zhengzhou and surrounding cities.

Cellular absorption and cytotoxic mitigation of heavy metals in mining vegetables in southwest China: Mechanistic insights and health implications

The existing health risk assessment models often rely on total concentrations of contaminants, neglecting cellular absorption, leading to an overestimation of risks due to a lack of toxicological verification. In this study, the content, bioaccessibility, and health risk evaluation of Cr, Ni, Cu, and As in vegetables from mining areas in Southwest China were examined. The cytotoxicity and gastric absorption of heavy metals and underlying mechanisms as well as the toxic mitigation approach after consumption of risky vegetables were explored. Our results showed that the heavy metals in cabbage, celery, and garlic seedlings were within the safety limit, even though grown in contaminated soils. The bioaccessibility of As, Cu, Ni, and Cr in vegetables in the gastric phase is from 6.92% to 81.15%, with mint having the highest bioaccessible concentrations of Cr (32.7 μg/kg), Cu (540.1 μg/kg), and As (103.9 μg/kg). The Hazard Quotient and Hazard Index values of the bioaccessible metals suggested an unacceptable cancer risk. Besides, the vegetable extracts increased cell apoptosis and tight junction disruption. Unexpectedly, the high-risk mint extract with the greatest bioaccessibility didn't cause cytotoxicity but inhibited cell apoptosis and enhanced cellular tight junction, evidenced by the upregulation of Zonula Occludens-1, Occludin, and Claudin 3, and a decrease in cellular heavy metal uptake. Furthermore, the mint extract could alleviate garlic seedling extract-induced cytotoxicity, indicating that the special substance in mint has protective effects. Taken together, special components in vegetables, cellular uptake, and toxicity of heavy metals should be considered in the accurate assessment of health risks.

Agricultural management could reduce soil N2O emissions while increasing grain yields via enhancing soil moisture harvesting and improving soil nutrient status

Intercropping can improve system productivity, but the effect of intercropping integrated with conservation tillage practices on soil N2O emissions remains unclear at the present stage. A 4-yr field experiment was performed in northwest China to examine soil moisture harvesting, soil nutrient status, and soil N2O emissions of wheat-maize intercropping with stubble residues and films management. We found that intercropping increased crop yields and reduced soil N2O emissions over monocultures. Across the intercropping treatments, NTSMFI (no-tillage with mulching stubbles and re-using residual films) and NTSSFI (no-tillage with standing stubbles and re-using residual films) boosted grain-yields by 13.8–17.1 % and 12.9–15.4 % over CTFI (conventional tillage without returning stubbles and mulching new films). NTSMFI and NTSSFI reduced soil N2O emissions by 18.4–28.7 % and 15.5–24.9 % compared to CTFI, respectively. So, NTSMFI and NTSSFI obtained a higher soil N2O emission efficiency than CTFI. The greater effect on soil N2O emissions reduction was detected in NTSMFI, and decreased by 5.1–5.4 % over NTSSFI. The main reason for NTSMFI to improve grain-yields and reduce soil N2O emissions was to enhance soil moisture harvesting and optimize the soil nutrient status. Compared to CTFI, NTSMFI increased the ratio of transpiration to evaporation by 14.4–32.0 %, improved soil organic carbon and total nitrogen concentrations, and soil C:N ratio of 0 to 60 cm soil depth by 14.1 %, 7.1 %, and 6.5 %, respectively. Adopting an environmentally clean strategy exemplified by NTSMFI was recommended as an effective technique for increasing-yields and reducing soil N2O emissions in arid irrigated regions.

Evaluating the Role of Nicotine Stereoisomer on Nicotine Pouch Abuse Liability: A Randomized Crossover Trial.

Many oral nicotine pouch (ONP) brands use synthetic nicotine, which typically contains a racemic (50:50) mixture of nicotine's two stereoisomers: S-nicotine and R-nicotine. Because tobacco-derived nicotine contains more than 99% S-nicotine, the effects of R-nicotine in humans are not well known. We compared systemic nicotine exposure and product appeal of ONPs containing more than 99% S-nicotine versus racemic nicotine. N = 18 adult smokers (Mage = 45 years, 66.7% male, 77.8% White) enrolled in a three-visit single-blind, randomized crossover study. During each visit, participants used one wintergreen-flavored, 3mg nicotine ONP for 30min following at least12h nicotine abstinence. Study ONP #1 contained more than 99% S-nicotine and the other two study ONPs contained racemic nicotine (collapsed for analyses). Plasma nicotine assessments and measures of withdrawal relief occurred at t = 0, 5, 15, 30, 60, and 90min; measures of product appeal were assessed following ONP use. Using the ONP with more than 99% S-nicotine resulted in greater plasma nicotine concentration from 15 to 90min (p < .0001) and greater maximum plasma nicotine concentration than the ONPs with racemic nicotine (M = 9.9ng/mL [SD = 2.5] vs. M = 5.7ng/mL [SD = 2.8], respectively; p < .0001). Product liking and withdrawal relief were similar across ONPs, although participants reported more "bad effects" when using the ONP with more than 99% S-nicotine. Participants reported few subjective differences in ONPs according to nicotine stereoisomer, but plasma nicotine concentration was greater for ONPs using more than 99% S-nicotine. ONPs with more than 99% S-nicotine (vs. racemic nicotine) might be better substitutes for cigarettes, but research into other ONP characteristics (eg flavors, freebasenicotine) is needed to inform regulation. Little is known about the effects of racemic (vs. S-) nicotine in humans. In a sample of adults who smoke cigarettes, we identified that oral nicotine pouches containing racemic nicotine exposed participants to less nicotine than oral nicotine pouches containing only S-nicotine, but both types of oral nicotine pouches held similar, moderate appeal. Additional research evaluating the roles that flavorings, total nicotine concentration, and freebase nicotine play in the abuse liability of oral nicotine pouches would inform comprehensive product regulations to support public health.

Correlating Gas/Particle-Phase Concentration of Indicator Polychlorinated Biphenyls with Meteorological Factors in Bayburt, an Important University City of Turkey

Correlating Gas/Particle-Phase Concentration of Indicator Polychlorinated Biphenyls with Meteorological Factors in Bayburt, an Important University City of Turkey

The relative contributions of traffic and non-traffic sources in ultrafine particle formations in Tehran mega city

Emissions of ultrafine particles (UFPs; diameter < 100 nm) are strongly associated with traffic-related emissions and are a growing global concern in urban environments. The aim of this study was to investigate the variations of particle number concentration (PNC) with a diameter > 10 nm at nine stations and understand the major sources of UFPs (primary vs. secondary) in Tehran megacity. The study was carried out in Tehran in 2020. NOx and PNC were reported from a total of nine urban site locations in Tehran and BC concentrations were examined at two monitoring stations. Data from all stations showed diurnal changes with peak morning and evening rush hours. The hourly PNC was correlated with NOx. PNCs in Tehran were higher compared to those of many cities reported in the literature. The highest concentrations were at District 19 station (traffic) and the lowest was at Punak station (residential) such that the average PNC varied from 8.4 × 103 to 5.7 × 104 cm−3. In Ray and Sharif stations, the average contributions of primary and secondary sources of PNC were 67 and 33%, respectively. Overall, we conclude that a decrease in primary emission leads to a decrease in the total concentration of aerosols, despite an increase in the formation of new particles by photo nucleation.