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Background: End-of-life dreams and visions (ELDVs) are prevalent experiences that provide comfort and meaning to dying individuals. Limited research has examined the impact of ELDVs on the bereaved...

A linear free energy model is presented that predicts the second-order rate constant for the abiotic reduction of nitroaromatic compounds (NACs). Previously presented models use the one-electron reduction potential E H 1 ( ArNO 2 ) of the NAC reaction ArNO 2 + e - → ArNO 2 • - . If E H 1 ( ArNO 2 ) is not available, it has been proposed that E H 1 ( ArNO 2 ) be computed directly or estimated from the gas-phase electron affinity (EA). The model proposed uses the Gibbs free energy of the hydrogen atom transfer (HAT) reaction ArNO 2 + H • → ArNOOH • as the parameter in the linear free energy model. Both models employ quantum chemical computations for the required thermodynamic energies. The available and proposed models are compared using experimentally determined second-order rate constants from 5 investigations from the literature in which a variety of NACs were exposed to a variety of reductants. A comprehensive analysis utilizing all the NACs and reductants demonstrate that the HAT energy model and the experimental one-electron reduction potential model have similar root mean square errors and residual error probability distributions. In contrast, the model using the computed EA has a more variable residual error distribution with a significant number of outliers. The results suggest that a linear free energy model utilizing computed HAT reaction free energy produces a more reliable prediction of the NAC abiotic reduction second-order rate constant than previously available methods. The advantages of the proposed HAT energy model and its mechanistic implications are discussed as well. Environ Toxicol Chem 2020;39:1678-1684. © 2020 SETAC.

The processes of aging and confronting mortality are often accompanied by unique psychological challenges. From the perspective of positive psychology, such challenges can yield opportunities for growth, including increased wisdom. This qualitative study explored 15 terminally ill hospice patients’ perspectives on wisdom, the dying process, and the meaning of life using consensual qualitative research methods. Most participants cited humility as a key component of wisdom, emphasizing that “Wisdom is when we realize ‘I don’t really know much’.” Other components of wisdom included self-knowledge, rationality, experiential learning, listening to and learning from others, and sharing knowledge with others. Participants also suggested that the process of facing illness and death presents opportunities for positive growth, including changing priorities and learning to appreciate life more fully in the present moment. In considering the sources of meaning in their lives, participants emphasized relational connec...

A growing number of correctional facilities train inmates to provide end-of-life care for dying inmates. This study explores the phenomenological perspective of inmate-caregivers participating in an inmate-facilitated hospice program (IFHP) with regard to meaning and purpose in life, attitudes on death and dying, and perceived personal impact of participation. Twenty-two inmate-caregivers were interviewed at a maximum-security state correctional facility in the United States. The interviews were transcribed verbatim and analyzed using the Consensual Qualitative Research Methodology. Results suggest that participating in an IFHP may facilitate personal growth and transformation that mirrors the tenets of posttraumatic growth.

Research indicates that informal caregiving can have intense physical and mental impact on the individual. Relative to caregivers of adults, pediatric palliative caregivers appear less in literature despite experiencing greater mental, physical, financial, and social strain. There is limited research on the creation and evaluation of interventions specifically for this population despite clear need.This study aims to evaluate the feasibility and engagement of the Photographs of Meaning Program, a modified meaning-making intervention for pediatric palliative caregivers.Participants completed a pre-post intervention meaning-in-life measure. Over a 9-week period, participants followed a meaning-making curriculum whereby they created and shared photo narratives via social media. As part of the intervention, a community photo exhibition was held featuring these photo narratives. Exit interviews were also conducted at study close.Nine individuals providing informal care to children in a pediatric palliative care program participated in the intervention. All participants were female and are older than 18 years. Settings for research include participant homes and at The Center for Hospice and Palliative Care in Cheektowaga, New York.Participants posted 95 photographs and 96 narratives during the intervention, posting on average once each week. Statistical analysis within the small sample indicated an increased presence of meaning in the lives of participants ( P = .022). Exit interviews conveyed satisfaction with the intervention.Findings suggest that the Photographs of Meaning Program is a practical intervention with life-enhancing potential for pediatric palliative. Future research should aim to collect additional evidence of the intervention's effectiveness.

For most complex traits, the majority of SNPs identified through genome-wide association studies (GWAS) reside within noncoding regions that have no known function. However, these regions are enriched for the regulatory enhancers specific to the cells relevant to the specific trait. Indeed, many of the GWAS loci that have been functionally characterized lie within enhancers that regulate expression levels of key genes. In order to identify polymorphisms with potential allele-specific regulatory effects, we developed a bioinformatics pipeline that harnesses epigenetic signatures as well as transcription factor (TF) binding motifs to identify putative enhancers containing a SNP with potential allele-specific TF binding in linkage disequilibrium (LD) with a GWAS-identified SNP. We applied the approach to GWAS findings for blood lipids, revealing 7 putative enhancers harboring associated SNPs, 3 of which lie within the introns of LCAT and ABCA1, genes that play crucial roles in cholesterol biogenesis and lipoprotein metabolism. All 3 enhancers demonstrated allele-specific in vitro regulatory activity in liver-derived cell lines. We demonstrated that these putative enhancers are in close physical proximity to the promoters of their respective genes, in situ, likely through chromatin looping. In addition, the associated alleles altered the likelihood of transcription activator STAT3 binding. Our results demonstrate that through our approach, the LD blocks that contain GWAS signals, often hundreds of kilobases in size with multiple SNPs serving as statistical proxies to the true functional site, can provide an experimentally testable hypothesis for the underlying regulatory mechanism linking genetic variants to complex traits.

Objective Zero-valent iron sand filtration can remove multiple contaminants, including some types of pathogenic bacteria, from contaminated water. However, its efficacy at removing complex viral populations, such as those found in reclaimed water used for agricultural irrigation, has not been fully evaluated. Therefore, this study utilized metagenomic sequencing and epifluorescent microscopy to enumerate and characterize viral populations found in reclaimed water and zero-valent iron-sand filtered reclaimed water sampled three times during a larger greenhouse study. Results Zero-valent iron-sand filtered reclaimed water samples had significantly less virus-like particles than reclaimed water samples at all collection dates, with the reclaimed water averaging between 108 and 109 and the zero-valent iron-sand filtered reclaimed water averaging between 106 and 107 virus-like particles per mL. In addition, for both sample types, viral metagenomes (viromes) were dominated by bacteriophages of the order Caudovirales, largely Siphoviridae, and genes related to DNA metabolism. However, the proportion of sequences homologous to bacteria, as well as the abundance of genes possibly originating from a bacterial host, was higher in the viromes of zero-valent iron-sand filtered reclaimed water samples. Overall, zero-valent iron-sand filtered reclaimed water had a lower total concentration of virus-like particles and a different virome community composition compared to unfiltered reclaimed water. Electronic supplementary material The online version of this article (10.1186/s13104-019-4251-y) contains supplementary material, which is available to authorized users.

Nitrogen (N) removal in conventional bioretention systems is highly variable owing to the low nitrate (NO3−) elimination efficiency. We hypothesized that amending bioretention cells with biochar and zero-valent iron (ZVI) could improve the NO3− removal performance. A well-instrumented, bi-layer pilot-scale bioretention cell was developed to test the hypothesis by investigating its hydrologic performance and NO3− removal efficacy as affected by biochar and ZVI amendments. The cell containing 18% (v/v) wood biochar in the vadose zone and 10% (v/v) ZVI in the saturation zone was monitored for 18 months of field infiltration tests using synthetic stormwater amended with bromide (tracer) and NO3−. Compared to the Control cell without amendments, the Biochar/ZVI cell increased water retention by 11–27% and mean residence time by 0.7–3.8 h. The vadose zone of the Biochar/ZVI cell removed 30.6–95.7% (0.6–12.7 g) of NO3-N from the influent, as compared with −6.1–89.6% (−0.1–2.9 g) by that of the Control cell. While the performance varied with synthetic storm events and seasons, in all cases the Biochar/ZVI cell resulted in greater NO3− removal than the Control cell. This improvement was presumably due to biochar's ability to improve water retention, facilitate anoxic conditions, increase residence time, and provide electrons for microbial denitrification. The saturation zone with ZVI amendment further promoted NO3− removal: removal was 1.8 times greater relative to the control in the first infiltration test, but was minimal in following tests. The reduction in performance of the ZVI amendment in subsequent tests might be due to diminished NO3-N input to the saturation zone after treatment by the biochar-amended vadose zone. The redox potential and dissolved oxygen content at the vadose/saturation zone interface also indicated more favorable denitrification conditions in the Biochar/ZVI cell. Biochar amendment demonstrated significant promise for increasing nitrate removal in bioretention systems.

Research on the environmental impacts of black carbon has focused largely on sorption. Besides being a strong geosorbent, black carbon is redox-active and may facilitate abiotic and microbial transformation. Using a wood-derived black carbon (biochar) and the bacterium Geobacter metallireducens (GS-15), we showed that air-oxidized biochar served as an electron acceptor to enable acetate oxidation, and that chemically or biotically reduced biochar served as an electron donor for nitrate reduction. The bioavailable (to GS-15) electron storage capacities (ESCs) of the biochar, estimated on the basis of acetate oxidation and nitrate reduction, were 0.85 and 0.87 mmol e–/g, respectively, comparable to the ESCs of humic substances and other biochars measured electrochemically. We propose that black carbon should be regarded as a rechargeable reservoir of bioavailable electrons in anaerobic environments. The redox cycling of biochar in natural and engineered systems and its impact on microbial processes and cont...

Transient changes in wettability complicate the prediction of biochar's hydrologic effects. Biochar wetting properties were characterized from poultry litter biochar (PLBC) produced from slow pyrolysis at temperatures between 300 and 600°C with water drop penetration time (persistence of hydrophobicity) and contact angle (CA; severity of hydrophobicity) measurements. Hydrophobicity was associated with semivolatile organic compounds coating PLBC surfaces, which resulted in 24.4 carbon layers and CAs of 101.1 ± 2.9° at a pyrolysis temperature of 300°C but only 0.4 layers of surface coverage and CAs of 20.6 ± 1.3° when pyrolyzed at 600°C. Mixing PLBC with water removed organic coatings, and storage in water for 72 h decreased CA as much as 81° for the most hydrophobic PLBCs. When mixed with quartz sand of the same particle size, CAs of PLBC-sand mixtures increased from 6.6 ± 1.4° at 0% PLBC mass fraction to 48.3 ± 2.0° at 15% mass fraction. Hydrophobic and hydrophilic PLBCs increased CA by nearly identical amounts at 2 and 5% mass fractions, which was explained by the influence of PLBC particle topology on macroscopic surface roughness of PLBC-sand mixtures. For environmentally relevant situations, PLBC-sand mixtures at mass fractions ≤15% remained water wetting. However, all PLBC additions increased CA, which may alter infiltration rates and induce preferential water flow.

Disorders of water balance, an excess or deficit of total body water relative to body electrolyte content, are common and ascertained by plasma hypo- or hypernatremia, respectively. We performed a two-stage genome-wide association study meta-analysis on plasma sodium concentration in 45,889 individuals of European descent (stage 1 discovery) and 17,637 additional individuals of European descent (stage 2 replication), and a transethnic meta-analysis of replicated single-nucleotide polymorphisms in 79,506 individuals (63,526 individuals of European descent, 8765 individuals of Asian Indian descent, and 7215 individuals of African descent). In stage 1, we identified eight loci associated with plasma sodium concentration at P-6. Of these, rs9980 at NFAT5 replicated in stage 2 meta-analysis (P=3.1 3 x 10-5), with combined stages 1 and 2 genomewide significance of P=5.6 x 10-10. Transethnic meta-analysis further supported the association at rs9980 (P=5.9 x 10-12). Additionally, rs16846053 at SLC4A10 showed nominally, but not genome-wide, significant association in combined stages 1 and 2 meta-analysis (P=6.7 x 10-8). NFAT5 encodes a ubiquitously expressed transcription factor that coordinates the intracellular response to hypertonic stress but was not previously implicated in the regulation of systemic water balance. SLC4A10 encodes a sodium bicarbonate transporter with a brain-restricted expression pattern, and variant rs16846053 affects a putative intronic NFAT5 DNA binding motif. The lead variants for NFAT5 and SLC4A10 are cis expression quantitative trait loci in tissues of the central nervous systemand relevant to transcriptional regulation. Thus, genetic variation in NFAT5 and SLC4A10 expression and function in the central nervous system may affect the regulation of systemic water balance.

Background: Elevated levels of low-density lipoprotein cholesterol (LDL-C) are a major risk factor for cardiovascular disease via its contribution to the development and progression of atherosclerotic lesions. Although the genetic basis of LDL-C has been studied extensively, currently known genetic variants account for only ≈20% of the variation in LDL-C levels. Methods: Through an array-based association analysis in 1102 Amish subjects, we identified a variant strongly associated with LDL-C levels. Using a combination of genetic analyses, zebrafish models, and in vitro experiments, we sought to identify the causal gene driving this association. Results: We identified a founder haplotype associated with a 15 mg/dL increase in LDL-C on chromosome 5. After recombination mapping, the associated region contained 8 candidate genes. Using a zebrafish model to evaluate the relevance of these genes to cholesterol metabolism, we found that expression of the transcribed pseudogene, APOOP1 , increased LDL-C and vascular plaque formation. Conclusions: Based on these data, we propose that APOOP1 regulates levels of LDL-C in humans, thus identifying a novel mechanism of lipid homeostasis.

Background: The age demographic of the incarcerated is quickly shifting from young to old. Correctional facilities are responsible for navigating inmate access to healthcare; currently, there is no standardization for access to end-of-life care. There is growing research support for prison-based end-of-life care programs that incorporate inmate peer caregivers as a way to meet the needs of the elderly and dying who are incarcerated. Aim: This project aims to (a) describe a prison-based end-of-life program utilizing inmate peer caregivers, (b) identify inmate-caregiver motivations for participation, and (c) analyze the role of building trust and meaningful relationships within the correctional end-of-life care setting. Design: A total of 22 semi-structured interviews were conducted with inmate-caregivers. Data were analyzed using Consensual Qualitative Research methodology. Setting/participants: All inmate-caregivers currently participating in the end-of-life peer care program at Briarcliff Correctional Facility were given the opportunity to participate. All participants were male, over the age of 18, and also incarcerated at Briarcliff Correctional Facility, a maximum security, state-level correctional facility. Results: In total, five over-arching and distinct domains emerged; this manuscript focuses on the following three: (a) program description, (b) motivation, and (c) connections with others. Conclusion: Findings suggest that inmate-caregivers believe they provide a unique and necessary adaptation to prison-based end-of-life care resulting in multilevel benefits. These additional perceived benefits go beyond a marginalized group gaining access to patient-centered end-of-life care and include potential inmate-caregiver rehabilitation, correctional medical staff feeling supported, and correctional facilities meeting end-of-life care mandates. Additional research is imperative to work toward greater standardization of and access to end-of-life care for the incarcerated.

Blast exposure is a major source of injury among Service members in the Iraq and Afghanistan conflicts. Many of these blast-exposed veterans report hearing-related problems such as difficulties understanding speech in noise and rapid speech, and following instructions and long conversations that are disproportionate to their measured peripheral hearing sensitivity. Evidence is mounting that these complaints result from damage to the central auditory processing system.To evaluate the effectiveness of audiological rehabilitative interventions for blast-exposed veterans with normal or near-normal peripheral hearing and functional hearing difficulties.A randomized controlled trial with four intervention arms.Ninety-nine blast-exposed veterans with normal or near-normal peripheral hearing who reported functional hearing difficulties.Four interventions were compared: compensatory communication strategies (CCS) education, CCS and use of a personal frequency modulation system (FM + CCS), CCS and use of an auditory training program (AT + CCS), and use of all three interventions combined (FM + AT + CCS).All participants tested before, and immediately following an 8-week intervention period. The primary outcome measures upon which the study was powered assessed speech understanding in noise and self-reported psychosocial impacts of the intervention. In addition, auditory temporal processing, auditory working memory, allocation of attention, and hearing and cognitive self-report outcomes were assessed.Use of FM + CCS resulted in significant benefit for speech understanding in noise and self-reported hearing benefits, and FM + AT + CCS provided more self-reported cognitive benefits than FM + CCS, AT + CCS, or CCS. Further, individuals liked and reported using the FM system, but there was poor adherence to and high attrition among individuals assigned to receive AT.It is concluded that a FM system (or remote microphone via Bluetooth system) is an effective intervention for blast-exposed veterans with normal or near-normal hearing and functional hearing difficulties and should be routinely considered as an intervention approach for this population when possible.

Delirium is a challenging occurrence among people at end of life. It can be difficult to detect and treat because of its episodic nature. The Buffalo Delirium Scale (BDS) was designed to identify risk factors for hospice patients in the prodromal stage of delirium.This study evaluated the psychometric properties of items assessing delirium risk factors related to cognitive problems, psychological distress, and sleep problems.Hospice nursing staff assessed patients with the 11-item BDS over a 6-month period as part of standard weekly visits to monitor for emerging signs of delirium, for example, sleep patterns, cognition, and behavior.The rating period produced 4992 assessments from 817 hospice home care patients.Factor analysis of nurses' ratings identified 3 factors: (1) cognitive problems, (2) distress, and (3) sleep problems. Coefficient αs for these factors and total score were moderate to high (range = .66-.82). Nurses' ratings of presence of delirium highly correlated with scores on distress ( r = .40, P.01), while dementia highly correlated with cognitive problems ( r = .50, P.01). Analysis of at-risk cases with high BDS total scores where no delirium was assessed indicated that quality sleep may mitigate delirium onset.Preliminary psychometric testing suggests BDS to be a valid and appropriate measure for hospice patients. Use of BDS may help differentiate individuals in prodromal stage of delirium versus dementia. Examination of BDS scores may help identify patients for whom sleep interventions may delay onset of or reduce the frequency of delirium.

Longitudinal assessment of patient-caregiver relationships will determine whether caregiver self-esteem determines patient relationship satisfaction at end of life.Research on close relationships and caregiving supports the idea that informal caregivers' self-esteem may influence their relationships with their terminally ill loved ones. However, this connection has not yet been investigated longitudinally, nor has it been applied specifically to care recipients' relationship satisfaction.A sample of 24 caregivers and 24 patients in a hospice home care program were recruited. Multiple patient and caregiver interviews were used to conduct a longitudinal study to measure fluctuations in patient health, changes in patient and caregiver relationship satisfaction, and self-esteem over a three-month period.An interaction between caregiver self-esteem and patient relationship satisfaction demonstrated the role that self-esteem plays between caregivers and patients enrolled in hospice care. Specifically, for patients with caregivers with low self-esteem, patient relationship satisfaction significantly decreased as the patient's physical health decreased, whereas for patients whose caregivers had high self-esteem, patient relationship satisfaction marginally increased during poorer physical health.High self-esteem may allow caregivers to overcome feelings of burden and maladaptive anticipatory grief to remain satisfied in their relationship with the patient. Caregiver self-esteem appears to play a role in fostering patient relationship satisfaction at the end of life.

In the United States, 5% of the population is responsible for nearly half of all health care expenditures, with a large concentration of spending driven by individuals with expensive chronic conditions in their last year of life. Outpatient palliative care under the Medicare Hospice Benefit excludes a large proportion of the chronically ill and there is widespread recognition that innovative strategies must be developed to meet the needs of the seriously ill while reducing costs.This study aimed to evaluate the impact of a home-based palliative care program, implemented through a hospice-private payer partnership, on health care costs and utilization.This was a prospective, observational database study where insurance enrollment and claims data were analyzed. The study population consisted of Home Connections (HC) program patients enrolled between January 1, 2010 and December 31, 2012 who subsequently expired (n=149) and who were also Independent Health members. A control group (n=537) was derived using propensity-score matching. The primary outcome variable was overall costs within the last year of life. Costs were also examined at six months, three months, one month, and two weeks. Inpatient, outpatient, ancillary, professional, and pharmacy costs were compared between the two groups. Medical service utilization and hospice enrollment and length of stay were also evaluated.Cost savings were apparent in the last three months of life—$6,804 per member per month (PMPM) cost for palliative care participants versus $10,712 for usual care. During the last two weeks of life, total allowed PMPM was $6,674 versus $13,846 for usual care. Enhanced hospice entry (70% versus 25%) and longer length of stay in hospice (median 34 versus 9 days) were observed.Palliative care programs partnered with community hospice providers may achieve cost savings while helping provide care across the continuum.

Hyperlipidemia and arterial cholesterol accumulation are primary causes of cardiovascular events. Monogenic forms of hyperlipidemia and recent genome-wide association studies indicate that genetics plays an important role. Zebrafish are a useful model for studying the genetic susceptibility to hyperlipidemia owing to conservation of many components of lipoprotein metabolism, including those related to LDL, ease of genetic manipulation, and in vivo observation of lipid transport and vascular calcification. We sought to develop a genetic model for lipid metabolism in zebrafish, capitalizing on one well-understood player in LDL cholesterol (LDL-c) transport, the LDL receptor (ldlr), and an established in vivo model of hypercholesterolemia. We report that morpholinos targeted against the gene encoding ldlr effectively suppressed its expression in embryos during the first 8 days of development. The ldlr morphants exhibited increased LDL-c levels that were exacerbated by feeding a high cholesterol diet. Increased LDL-c was ameliorated in morphants upon treatment with atorvastatin. Furthermore, we observed significant vascular and liver lipid accumulation, vascular leakage, and plaque oxidation in ldlr-deficient embryos. Finally, upon transcript analysis of several cholesterol-regulating genes, we observed changes similar to those seen in mammalian systems, suggesting that cholesterol regulation may be conserved in zebrafish. Taken together, these observations indicate conservation of ldlr function in zebrafish and demonstrate the utility of transient gene knockdown in embryos as a genetic model for hyperlipidemia.

Fluorinated compounds have become prevalent in ecosystems because of their widespread use, yet few methods that can effectively degrade these pollutants exist. We investigated the catalytic reduction of vinyl fluoride (VF), a regulated high-volume chemical and probable carcinogen, over rhodium in H2 gas or aqueous solution. Water controlled both the kinetics and products of VF reduction. In dry H2 gas, VF was reduced through primarily hydrogenation, at rates that were too fast to measure. In liquid water, reaction was first-order in both VF and rhodium concentrations and proceeded predominantly through hydrodefluorination. Experiments and calculations show the reaction was mass transfer-limited. Even adsorbed water molecules on the catalyst surface posed a significant mass transfer barrier and dramatically altered product selectivity. These results provide insights into the kinetics and pathway of VF defluorination and are important for the design of studies that aim to elucidate the reduction mechanisms ...

Objective:Hospice patients often struggle with loss of meaning, while many experience meaningful dreams. The purpose of this study was to conduct a preliminary exploration into the process and therapeutic outcomes of meaning-centered dream work with hospice patients.Method:A meaning-centered variation of the cognitive–experiential model of dream work (Hill, 1996; 2004) was tested with participants. This variation was influenced by the tenets of meaning-centered psychotherapy (Breitbart et al., 2012). A total of 12 dream-work sessions were conducted with 7 hospice patients (5 women), and session transcripts were analyzed using the consensual qualitative research (CQR) method (Hill, 2012). Participants also completed measures of gains from dream interpretation in terms of existential well-being and quality of life.Results:Participants' dreams generally featured familiar settings and living family and friends. Reported images from dreams were usually connected to feelings, relationships, and the concerns of waking life. Participants typically interpreted their dreams as meaning that they needed to change their way of thinking, address legacy concerns, or complete unfinished business. Generally, participants developed and implemented action plans based on these interpretations, despite their physical limitations. Participants described dream-work sessions as meaningful, comforting, and helpful. High scores on a measure of gains from dream interpretation were reported, consistent with qualitative findings. No adverse effects were reported or indicated by assessments.Significance of Results:Our results provided initial support for the feasibility and helpfulness of dream work in this population. Implications for counseling with the dying and directions for future research were also explored.

Inpatient palliative care (IPC) has been associated with numerous clinical benefits. Observational and randomized studies of cost savings associated with IPC provide conflicting results, and the association with readmission is not well understood.We aimed to estimate the influence of IPC on hospitalization costs and readmission rates.We measured hospitalization costs and 30-day readmission rates among 1004 patients who received IPC at two western New York hospitals in 2012. Using propensity score matching, we compared outcomes among patients receiving palliative care with those among 1004 similar adults who were hospitalized during the same period and did not receive palliative care.On average, cost per admission was $1,401 (13%) lower among patients receiving palliative care than comparison patients (p0.05). Cost reductions were evident within intensive care and laboratory services. Readmission rates were significantly lower among palliative care patients discharged with hospice care (1.1%) than comparison patients (6.6%), but significantly higher among palliative care patients discharged to other locations (12.1%).Receipt of IPC appears to reduce hospitalization costs among adult western New Yorkers. Furthermore, care coordinated with postdischarge hospice services appears to substantially reduce the likelihood of readmission.

The objective of this study is to investigate the fate of redox-sensitive nitro compounds in the presence of black carbon (BC) materials in electron-rich subsurface environments. The ability of various types of BC was examined, including graphite, carbon nanotubes, chemically converted graphene, activated carbon, diesel soot, and biochar, to promote the reduction of 2,4-dinitrotoluene, pendimethalin, and trifluralin by hydrogen sulfide, a naturally occurring reductant, through batch experiments. Compared to removal in sorption control experiments with BC materials and direct transformation with hydrogen sulfide, the presence of BC markedly enhanced the reduction of nitro compounds by hydrogen sulfide, indicating that BC can be an electron-transfer mediator in the presence of hydrogen sulfide. Possible mechanisms and environmental implications of BC-mediated reduction reactions in soils and sediments are discussed.