The involvement of oxidative stress mediated endoplasmic reticulum pathway in apoptosis of Golden Pompano (Trachinotus blochii) liver under PS-MPs stress.

Globally, microplastics (MPs) are highly prevalent, especially in coastal areas. Unfortunately, golden pompano as a major marine fish in China is typically raised in floating marine cages near coasts, facing these MPs sources. However, toxicological studies on Golden Pompano which farm in coastal areas and face actual microplastic exposure are rare. Therefore, golden pompano were exposed to 10.0 µg/L, 100.0 µg/L, and 1000.0 µg/L polystyrene MPs (PS-MPs) for 14 days to study the potential impact of the microplastics on the Golden Pompano. Fish show slowed growth after 14 days of exposure. Histopathology shows irregular shaped nuclei and nuclear and cytoplasmic vacuolation traits in liver. Oxidative stress-related enzyme activity and gene expression data show that oxidative damage occurs in the high-concentrations (100.0 µg/L and 1000.0 µg/L) of PS-MPs exposures. Up-regulation of Grp78, Xbp-1, Eif-2α and chop gene expression indicates the occurrence of endoplasmic reticulum stress, and the western blot results also confirmed this. Severe oxidative stress also caused ERS, which ultimately increased BAX/Bcl-2 ratios and induces apoptosis. Furthermore, up-regulated anaerobic respiration, altered lipid metabolism, and immune disturbance were exhibited during PS-MPs stress. Therefore, oxidative stress appeared to be the main toxicity issue caused by MPs, while ERS-mediated apoptosis, metabolic alterations, and immune responses were induced by this stress. Notably, endoplasmic reticulum stress and apoptosis are a self-protective mechanism, which may be an intermediate link in the toxicity of microplastics. This study highlights the role of endoplasmic reticulum stress in MPs toxicology and assesses the adverse effects of microplastics on Golden Pompano.

OfGNBP silencing enhances the toxicity of Serratia marcescens Bizio (SM1) to Odontotermes formosanus (Shiraki).

The immunity of insects plays a vital role in their survival. Our experiments found that lipopolysaccharide (LPS) and glucono-δ-lactone (GDL) could influence the virulence of Serratia marcescens Bizio (SM1) to Odontotermes formosanus (Shiraki) by affecting the immunity. Gram-negative binding proteins (GNBPs) are an important pattern recognition proteins that play a crucial role in the innate immune system. Therefore, two OfGNBPs were cloned in O. formosanus. The expression of OfGNBPs was significantly changed by LPS,SM1 and GDL, not prick. In addition, the immune-related gene expression, the phenoloxidase activity and antibacterial activity of donor termites and recipient termites were significantly induced by SM1. Furthermore, the knockdown of OfGNBP by RNA interference reduced not only individual immunity but also social immunity in O. formosanus, which increased the virulence of SM1 to O. formosanus. Importantly, dsOfGNBP alone also had good control effect on O. formosanus. In summary, we concluded that dsOfGNBPs are important termite immunosuppressants.

[Progress in stimuli-responsive molecularly imprinted polymers for enrichment analysis of trace components in traditional Chinese medicine].

Molecularly imprinted polymers demonstrate outstanding performance in the research on trace ingredients because of their high selectivity. Stimuli-responsive molecularly imprinted polymers(STR-MIPs) with the introduction of different responsive groups on the basis of traditionally imprinted materials can undergo reversible transformations when exposed to external stimuli such as temperature, magnetism, pH or light. Such responsiveness, combined with the specific recognition, endows STR-MIPs with excellent perfor-mance in trace component studies. Traditional Chinese medicine(TCM) contains complex components with trace content, and thus STR-MIPs have broad application prospects in the enrichment analysis of trace components in TCM. This paper elaborates on the application of STR-MIPs in the enrichment analysis of trace components in TCM from the perspectives of different stimuli, summarized relevant research achievements in the recent five years to broaden the application fields of molecular imprinting, and proposed a few opi-nions about their future development.

[Clinical characteristics of plastic bronchitis and risk factors for recurrence in children]. / å„¿ç«¥å¡‘åž‹æ€§æ”¯æ°”ç®¡ç‚Žä¸´åºŠç‰¹å¾åŠå¤å‘å±é™©å› ç´ åˆ†æž.

OBJECTIVES: To study the clinical characteristics of plastic bronchitis (PB) in children and investigate the the risk factors for recurrence of PB. METHODS: This was a retrospective analysis of medical data of children with PB who were hospitalized in Children's Hospital of Chongqing Medical University from January 2012 to July 2022. The children were divided into a single occurrence of PB group and a recurrent PB group and the risk factors for recurrence of PB were analyzed. RESULTS: A total of 107 children with PB were included, including 61 males (57.0%) and 46 females (43.0%), with a median age of 5.0 years, and 78 cases (72.9%) were over 3 years old. All the children had cough, 96 children (89.7%) had fever, with high fever in 90 children. Seventy-three children (68.2%) had shortness of breath, and 64 children (59.8%) had respiratory failure. Sixty-six children (61.7%) had atelectasis and 52 children (48.6%) had pleural effusion. Forty-seven children (43.9%) had Mycoplasma pneumoniae infection, 28 children (26.2%) had adenovirus infection, and 17 children (15.9%) had influenza virus infection. Seventy-one children (66.4%) had a single occurrence of PB, and 36 cases (33.6%) had recurrent occurrence of PB (≥2 times). Multivariate logistic regression analysis showed that involvement of ≥2 lung lobes (OR=3.376) under bronchoscopy, continued need for invasive ventilation after initial removal of plastic casts (OR=3.275), and concomitant multi-organ dysfunction outside the lungs (OR=2.906) were independent risk factors for recurrent occurrence of PB (P<0.05). CONCLUSIONS: Children with pneumonia accompanied by persistent high fever, shortness of breath, respiratory failure, atelectasis or pleural effusion should be highly suspected with PB. Involvement of ≥2 lung lobes under bronchoscopy, continued need for invasive ventilation after initial removal of plastic casts, and concomitant multi-organ dysfunction outside the lungs may be risk factors for recurrent occurrence of PB.

Termicin silencing enhances the toxicity of Serratia marcescens Bizio (SM1) to Odontotermes formosanus (Shiraki).

Termites are often exposed to a variety of pathogens during their life cycle, which has led to the development of an innate immune system to resist these pathogens. Antimicrobial peptides (AMPs) play a crucial role in the innate immune system in insects. However, clear information on AMPs in termites has not been obtained. Therefore, exploring the function of AMPs in the subterranean termite Odontotermes formosanus (Shiraki) can lead to the development of novel termite control strategies that integrate RNA interference (RNAi) and pathogens. Here we first obtained two Oftermicins from O. formosanus and observed that the expression of these Oftermicin genes was significantly upregulated at the mRNA level after treatment with lipopolysaccharide (LPS) or Serratia marcescens Bizio (SM1). Interestingly, the expression of these Oftermicins increased not only in the donor termites but also in the recipient termites through transmission experiments. Bioassay experiments showed that the mortality of O. formosanus treated with SM1 after RNAi was significantly higher than that of other groups. In summary, dsOftermicins are important immunosuppressants for termite control and Oftermicins are optimal targets for termite control based on the combined use of RNAi and pathogens.

Prophenoloxidase of Odontotermes formosanus (Shiraki) (Blattodea: Termitidae) Is a Key Gene in Melanization and Has a Defensive Role during Bacterial Infection.

Melanization mediated by the prophenoloxidase (PPO)-activating system is an important innate immunity to fight pathogens in insects. In this study, the in vitro time-dependent increase in the intensity of melanization and phenoloxidase (PO) activity from the hemolymph of Odontotermes formosanus (Shiraki) challenged by pathogenic bacteria was detected. PPO is one of the key genes in melanization pathway, whereas the molecular characteristics and functions of O. formosanus PPO are unclear. The OfPPO gene was cloned and characterized. The open reading frame of OfPPO is 2085 bp in length and encodes a 79.497 kDa protein with 694 amino acids. A BLASTx search and phylogenetic analyses revealed that OfPPO shares a high degree of homology to the Blattodea PPOs. Moreover, real-time fluorescent quantitative PCR analysis showed that OfPPO is ubiquitously expressed in all castes and tissues examined, with the highest expression in workers and variable expression patterns in tissues of different termite castes. Furthermore, the expression of OfPPO was significantly induced in O. formosanus infected by pathogenic bacteria. Intriguingly, in combination with silencing of OfPPO expression, pathogenic bacteria challenge caused greatly increased mortality of O. formosanus. These results suggest that OfPPO plays a role in defense against bacteria and highlight the novel termite control strategy combining pathogenic bacteria application with termite PPO silencing.

Modeling the Conditional Fragmentation-Induced Microplastic Distribution.

Microplastics (MPs) are drawing increasing attention from the international community due to their potential threats to the ecosystem and human health. Although their occurrence and spatial distribution have been extensively studied in recent years, the relationship between their abundance and sizes remains unclear. Moreover, the underlying mechanisms dominating their size distribution have rarely been explored. In the present study, we developed a novel conditional fragmentation model to describe MP size distribution in the soil environment. It is proposed that the distribution of MPs is not a coincidence but controlled by conditional aging. The applicability of this model was tested using data collected from different land use settings in Beijing, China. A distinct downsizing phenomenon from fibers, films, and fragments to granules is observed. Undisturbed land use types accumulated larger sized MPs with higher stability, while human interference accelerated the fragmentation of MPs. Both morphological analysis and time-of-flight secondary ion mass spectroscopy (TOF-SIMS) observations provided direct evidence for the conditional fragmentation process. Furthermore, the model has proven to be suitable for describing the size distribution of MPs from various sources (including atmospheric deposition, transportation, and agriculture) and aging processes (such as mechanical abrasion, chemical oxidation, and photochemical transformation). It is proposed that this model can be used for various purposes in MP-related studies, especially source identification, transport modeling, and risk assessment.

[Effects of Heat Treatment Conditions on Shape Memory Recovery of NiTi Self-expanding Vascular Stents].

Effects of heat treatment conditions (including temperature and time) on the shape memory recovery and corrosion resistance of NiTi self-expanding vascular stents were studied based on working mechanism and clinical use. The Af temperature, dimensional recovery, crush resistance with radially applied load and point applied load of stents and corrosion resistance were characterized in diffident heat treatment conditions. The research results allow the conclusion that the stent treated at 500 ℃ for 10 min has optimum performance, and corrosion resistance meets the requirements.

Engineering Responses to Amino Acid Substitutions in the VP0- and VP3-Coding Regions of PanAsia-1 Strains of Foot-and-Mouth Disease Virus Serotype O.

The presence of sequence divergence through adaptive mutations in the major capsid protein VP1, and also in VP0 (VP4 and VP2) and VP3, of foot-and-mouth disease virus (FMDV) is relevant to a broad range of viral characteristics. To explore the potential role of isolate-specific residues in the VP0 and VP3 coding regions of PanAsia-1 strains in genetic and phenotypic properties of FMDV, a series of recombinant full-length genomic clones were constructed using Cathay topotype infectious cDNA as the original backbone. The deleterious and compensatory effects of individual amino acid substitutions at positions 4008 and 3060 and in several different domains of VP2 illustrated that the chain-based spatial interaction patterns of VP1, VP2, and VP3 (VP1-3), as well as between the internal VP4 and the three external capsid proteins of FMDV, might contribute to the assembly of eventually viable viruses. The Y2079H site-directed mutants dramatically induced a decrease in plaque size on BHK-21 cells and viral pathogenicity in suckling mice. Remarkably, the 2079H-encoding viruses displayed a moderate increase in acid sensitivity correlated with NH4Cl resistance compared to the Y2079-encoding viruses. Interestingly, none of all the 16 rescued viruses were able to infect heparan sulfate-expressing CHO-K1 cells. However, viral infection in BHK-21 cells was facilitated by utilizing non-integrin-dependent, heparin-sensitive receptor(s) and replacements of four uncharged amino acids at position 3174 in VP3 of FMDV had no apparent influence on heparin affinity. These results provide particular insights into the correlation of evolutionary biology with genetic diversity in adapting populations of FMDV.IMPORTANCE The sequence variation within the capsid proteins occurs frequently in the infection of susceptible tissue cultures, reflecting the high levels of genetic diversity of FMDV. A systematic study for the functional significance of isolate-specific residues in VP0 and VP3 of FMDV PanAsia-1 strains suggested that the interaction of amino acid side chains between the N terminus of VP4 and several potential domains of VP1-3 had cascading effects on the viability and developmental characteristics of progeny viruses. Y2079H in VP0 of the indicated FMDVs could affect plaque size and pathogenicity, as well as acid sensitivity correlated with NH4Cl resistance, whereas there was no inevitable correlation in viral plaque and acid-sensitive phenotypes. The high affinity of non-integrin-dependent FMDVs for heparin might be explained by the differences in structures of heparan sulfate proteoglycans on the surfaces of different cell lines. These results may contribute to our understanding of the distinct phenotypic properties of FMDV in vitro and in vivo.

A flexible ultrasound transducer array with micro-machined bulk PZT.

This paper proposes a novel flexible piezoelectric micro-machined ultrasound transducer, which is based on PZT and a polyimide substrate. The transducer is made on the polyimide substrate and packaged with medical polydimethylsiloxane. Instead of etching the PZT ceramic, this paper proposes a method of putting diced PZT blocks into holes on the polyimide which are pre-etched. The device works in d31 mode and the electromechanical coupling factor is 22.25%. Its flexibility, good conformal contacting with skin surfaces and proper resonant frequency make the device suitable for heart imaging. The flexible packaging ultrasound transducer also has a good waterproof performance after hundreds of ultrasonic electric tests in water. It is a promising ultrasound transducer and will be an effective supplementary ultrasound imaging method in the practical applications.

Long-read single-cell sequencing reveals expressions of hypermutation clusters of isoforms in human liver cancer cells.

The protein diversity of mammalian cells is determined by arrays of isoforms from genes. Genetic mutation is essential in species evolution and cancer development. Accurate long-read transcriptome sequencing at single-cell level is required to decipher the spectrum of protein expressions in mammalian organisms. In this report, we developed a synthetic long-read single-cell sequencing technology based on LOOPSeq technique. We applied this technology to analyze 447 transcriptomes of hepatocellular carcinoma (HCC) and benign liver from an individual. Through Uniform Manifold Approximation and Projection analysis, we identified a panel of mutation mRNA isoforms highly specific to HCC cells. The evolution pathways that led to the hyper-mutation clusters in single human leukocyte antigen molecules were identified. Novel fusion transcripts were detected. The combination of gene expressions, fusion gene transcripts, and mutation gene expressions significantly improved the classification of liver cancer cells versus benign hepatocytes. In conclusion, LOOPSeq single-cell technology may hold promise to provide a new level of precision analysis on the mammalian transcriptome.

Foot-and-mouth disease virus-like particles produced by a SUMO fusion protein system in Escherichia coli induce potent protective immune responses in guinea pigs, swine and cattle.

Foot-and-mouth disease virus (FMDV) causes a highly contagious infection in cloven-hoofed animals. The format of FMD virus-like particles (VLP) as a non-replicating particulate vaccine candidate is a promising alternative to conventional inactivated FMDV vaccines. In this study, we explored a prokaryotic system to express and assemble the FMD VLP and validated the potential of VLP as an FMDV vaccine candidate. VLP composed entirely of FMDV (Asia1/Jiangsu/China/2005) capsid proteins (VP0, VP1 and VP3) were simultaneously produced as SUMO fusion proteins by an improved SUMO fusion protein system in E. coli. Proteolytic removal of the SUMO moiety from the fusion proteins resulted in the assembly of VLP with size and shape resembling the authentic FMDV. Immunization of guinea pigs, swine and cattle with FMD VLP by intramuscular inoculation stimulated the FMDV-specific antibody response, neutralizing antibody response, T-cell proliferation response and secretion of cytokine IFN-γ. In addition, immunization with one dose of the VLP resulted in complete protection of these animals from homologous FMDV challenge. The 50% protection dose (PD50) of FMD VLP in cattle is up to 6.34. These results suggest that FMD VLP expressed in E. coli are an effective vaccine in guinea pigs, swine and cattle and support further development of these VLP as a vaccine candidate for protection against FMDV.

Microplastics in urban runoff: Global occurrence and fate.

Public concerns on microplastic (MP) pollution and its prevalence in urban runoff have grown exponentially. Huge amounts of MPs are transported from urban environments via surface runoff to different environment compartments, including rivers, lakes, reservoirs, estuaries, and oceans. The global concentrations of MPs in urban runoff range from 0 to 8580 particles/L. Understanding the sources, abundance, composition and characteristics of MPs in urban runoff on a global scale is a critical challenge because of the existence of multiple sources and spatiotemporal heterogeneity. Additionally, dynamic processes in the mobilization, aging, fragmentation, transport, and retention of MPs in urban runoff have been largely overlooked. Furthermore, the MP flux through urban runoff into rivers, lakes and even oceans is largely unknown, which is very important for better understanding the fate and transport of MPs in urban environments. Here, we provide a critical review of the global occurrence, transport, retention process, and sinks of MPs in urban runoff. Relevant policies, regulations and measures are put forward. Future global investigations and mitigation efforts will require us to address this issue cautiously, cooperating globally, nationally and regionally, and acting locally.

Nanoplastic stimulates metalloid leaching from historically contaminated soil via indirect displacement.

It is generally believed that the ability of nanoplastics (NPs) to mobilize other contaminants is due to direct adsorption; however, this intuitive belief is questioned in this study when it comes to a historically contaminated soil where mining activities since 1958 have resulted in arsenic (As) and cadmium (Cd) enrichment. Negatively charged polystyrene (PS) NPs were used in this study, which should theoretically stimulate Cd (metal cation) instead of As (negatively charged oxyanion) leaching if direct adsorption accounted for co-transport. Surprisingly, PS NPs enhanced the leaching of As by up to over 5 times (p value < 0.05), but had almost no effect on Cd leaching (p value > 0.05). A novel indirect displacement model was therefore developed to describe the phenomenon of enhanced As leaching. It has been found that negatively charged NPs interacted with As via competition for soil binding sites. Underlying mechanistic insights were further explored via both theoretical calculations with the Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) approach, and direct characterization using Scanning Electron Microscopy (SEM) and Computed X-ray Microtomography (µCT) showing binding sites and flow channels, respectively. The overall results provide new and valuable insights into NP-metal(loid) interactions in the natural soil environment, which can be integrated in future studies regarding the transport and risk assessment of NPs, and toxic metal(loid)s.

Co-encapsulation systems for delivery of bioactive ingredients.

To improve the solubility, stability and bioavailability of bioactive compounds, a series of delivery systems have been designed and developed in recent years. However, most delivery systems are limited to loading a single nutrient. Co-delivery systems that encapsulate two or more nutrients have great sense to enhance the nutritional values and health benefits of food products. In this paper, the recent advancements of co-encapsulation systems including emulsions, nanoparticles, microcapsules, liposomes, hydrogels, and related products have been reviewed. The co-encapsulation mechanisms of bioactive ingredients in various delivery systems were illustrated. Furthermore, the release, digestion and absorption mechanisms of bioactive ingredients in the human digestive system were also discussed. Co-encapsulation systems have the ability to mask astringency of different bioactive ingredients and enhance their stability and bioavailability, as well as to maximize the biological function of bioactive ingredients with synergistic effect. The present review provides examples for the application of co-encapsulation systems in food industries.

Emamectin benzoate nanogel suspension constructed from poly(vinyl alcohol)-valine derivatives and lignosulfonate enhanced insecticidal efficacy.

To reduce the negative impact of nanopesticide carriers of on the environment, a greener nanodelivery system is necessary. Nanogels are nontoxic and degradable carriers, however, the potential of nanogels for delivering pesticides has not been proven. In this study, poly(vinyl alcohol)-valine, an ecofriendly polymer, was synthesized and used to fabricate emamectin benzoate nanogel suspension (EB NS). The nanoformulation showed favorable stability at low temperature, high temperature or one year storage, and in water with different hardnesses. The retention of the EB NS solution on leaves was higher than that of an EB emulsifiable concentrate (EC) by approximately 9% at a concentration of 10 mg L-1. The half-life of EB nanogels under Ultra Violet irradiation was prolonged by 3.3-fold. Moreover, the bioactivity of the EB NS against Plutella xylostella was higher than that of the EB EC. These advantages resulted in a relatively long duration of pest control. The response of nanogels to laccase, a digestive enzyme in the digestive tract of lepidopteran pests, enables pesticide release on demand. Nanogels have the advantages of being ecofriendly carriers, exhibiting higher utilization, and prolonged pest control periods, and they have a brilliant future in pesticide delivery.

A simple and rapid procedure for purification of haptoglobin from human plasma fraction IV.

Human plasma fraction IV is an intermediate precipitate during the production of human serum albumin using cold ethanol method. Haptoglobin locates in this fraction can be purified for various applications. A new process integration of polyethylene glycol (PEG) precipitation and ion-exchange chromatography (IEC) was developed for purification of haptoglobin, which could effectively purify the haptoglobin from 16.6% to 95%. The recovery of the new process was 58.2% in comparison to 30.3% of the conventional affinity chromatography. Furthermore, 175 mg haptoglobin production in a scaled-up process showed the method to be simple, fast, and low-cost.

Assessment of transportation processes of polyacrylamide in chernozem and saline soil by numerical model.

Polyacrylamide (PAM) was studied in two characteristic soils in Daqing City: chernozem and saline soil. 120 mg L-1 of KBr was used as a conservation tracer to estimate diffusion coefficients and pore velocities of chernozem and saline soil by using the breakthrough curves (BTCs) of Br-. Isothermal adsorption equations were coupled with the traditional two-site model to establish the transportation equation of PAM. The results of comparing the simulation curve with the BTCs of PAM at different rates showed that the transportation equation of PAM could simulate the transport process of PAM in soil column accurately. PAM behaved as non-equilibrium adsorption in both soils by calculating the kinetic parameters in this equation. The results of this work not only confirmed the kinetic parameters of PAM in both soils, but also found that there is a good liner relationship between the mass transfer coefficient and pore velocity. The R2 values of the two linear equations are 0.983 and 0.979. These linear equations provide a good prediction basis for site prediction. In addition, it was found that organic matter is the main influence factor for the adsorption capacity of chernozem causing significantly larger than that of saline soil.

Self-Assembled Degradable Nanogels Provide Foliar Affinity and Pinning for Pesticide Delivery by Flexibility and Adhesiveness Adjustment.

At present, it is highly important to develop a simple and compatible nano delivery system for pesticides for foliar application, which can improve their insecticidal efficacy and resistance to adverse climates while reducing the environmental risks. Polyethylene glycol and 4,4-methylenediphenyl diisocyanate are used as hydrophilic soft and hydrophobic hard segments, respectively, for polymer self-assembly and polyurethane gelation in a nanoreactor. The nanocarrier synthesis and the pesticide loading are realized by a one-step integration procedure and suited well for hydrophobic active compounds. Modifying the molecular structure of the soft segment can adjust the flexibility of the nanocarriers and result in viscosity and deformation characteristics. After foliar spray application, the foliar flattening state of the nanogels increases the foliar protection area by 2.21 times and improves both pesticide exposure area and target contact efficiency. Concurrently, the flexibility and viscosity of the nanogels increase the washing resistance and the retention rate of the pesticide by approximately 80 times under continuous washing. The encapsulation of the nanogels reduces the foliar ultraviolet (UV) degradation and aquatic pesticide exposure, which increase the security of λ-cyhalothrine by 9.33 times. Moreover, the degradability of nanogels is beneficial for pesticide exposure and reducing pollution. This system has simple preparation, good properties, and environmental friendliness, making the nanocarriers promising for delivering pesticides.

Vertical migration of microplastics in porous media: Multiple controlling factors under wet-dry cycling.

Terrestrial soils are not only a large reservoir for Microplastics (MPs), but also a possible entrance to the subsurface environment, posing potential risks to the subterranean habitats and groundwater. In this study, we examined the vertical transport of MPs of four polymers, i.e., polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP) and polyamide (PA), in porous sand media driven by wet-dry cycling. The effects of polymer properties, MP size, sand particle size, wet-dry cycles, and dissolved organic matter (DOM) on their migration behavior were investigated. Surface hydrophobicity showed a strong positive correlation with MP mobility, with PA exhibiting the greatest movement potential, followed by PE, PET, and PP. The penetration depth of MP particles increased with decreasing MP particle size (dMP) and increasing sand diameter (dsand). MP particles migrated deeper in sand media when dMP/dsand < 0.11. Furthermore, frequent wet-dry cycles and the presence of DOM promoted the vertical migration of MPs in the sand. The results revealed multiple factors influencing the vertical migration of MPs in sand, which is instructive for understanding the ecological risk of MPs in potentially contaminated soil (e.g., farmland with long-term mulching) to the subsurface environment and potential negative impact to public health.