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A system-level metastable model of cancer evolution: integrating replication stress, cell cycle deregulation and chromosomal instability.

INTRODUCTION: Cancer cell proliferation occurs within the context of persistent genomic instability. In this review, we propose the RS-CCD-CIN axis as a systems-level framework in which replication stress (RS), cell cycle deregulation (CCD) and chromosomal instability (CIN) form an interdependent triad that shapes tumour evolution. This axis represents a constrained metastable state in which genomic instability is tolerated and buffered. The objective of this review is to synthesize the current understanding of how the RS-CCD-CIN axis contributes to tumour heterogeneity, adaptability and therapy response. DISCUSSION: Evidence indicates that RS, CCD and CIN operate as a dynamic, interconnected network rather than as independent processes. Replication stress induces DNA damage and mutagenesis, while partial checkpoint disruption permits cells with unresolved lesions to proliferate. Chromosomal instability generates both structural and numerical alterations, contributing to intratumoural heterogeneity. Together, these processes facilitate adaptation to environmental and therapeutic pressures. Extrachromosomal DNA, micronuclei formation and cytosolic DNA signalling, including the cGAS-STING pathway, connect genomic instability to adaptive responses and immune modulation. Single-cell and spatial profiling reveal temporal and spatial variability in RS, CCD and CIN states, highlighting the limitations of static biomarkers. Therapeutically, targeting individual components often yields limited durability, whereas approaches that simultaneously perturb multiple aspects of the RS-CCD-CIN axis may improve clinical outcomes. CONCLUSIONS: This review highlights the RS-CCD-CIN axis as a fragile and metastable architecture that supports cancer evolution, while also being susceptible to collapse. A deeper understanding of this interconnected framework may inform the development of therapeutic strategies and enhance the management of resistance.

Humans

Effect of demographic characteristics on the outcome of prostate cancer salvage radiotherapy: Analysis from a randomized controlled trial.

BACKGROUND: This study investigated the impact of advanced molecular imaging, race, socioeconomic status, and metabolic dysregulation on the outcome of salvage radiotherapy (sRT) for prostate cancer recurrence in a clinical trial setting. METHODS: The authors randomized post-prostatectomy men with detectable prostate-specific antigen to sRT guided by conventional imaging (arm A) or 18F-fluciclovine-positron emission tomography/computed tomography (arm B) and followed them up for up to 48 months to determine failure-free survival (FFS). The authors computed socioeconomic status (SES) and allostatic load (AL) scores to quantify socioeconomic status and level of metabolic dysregulation. They stratified patients by race as African American men (AAM) versus men of other races (MOR) and compared FFS between them using the z-test. RESULTS: Eighty-one (AAM = 29, MOR = 52) and 76 (AAM = 26, MOR = 50) men completed per-protocol sRT in arms A and B, respectively. Across study arms, AAM showed a higher FFS rate than MOR (72.8% [95% CI, 53.8%-85.0%] vs. 58.7% [95% CI, 46.6%-68.9%]; p = .002). In arm A, FFS rate was better for AAM than MOR, (64.0% [95% CI, 34.4%-82.9%] vs. 45.3% [95% CI, 28.8%-60.4%]; p = .008). In arm B, FFS improved for both groups but less so for AAM, (81.5% [95% CI, 57.2%-92.7%] vs. 73.0% [95% CI, 56.3%-84.1%]; p = .131). The authors found lower SES scores and higher AL scores for AAM in both study arms than MOR. CONCLUSION: Despite lower socioeconomic status and higher burden of metabolic dysregulation, in a clinical trial setting that controls for disparities in health care access, AAM have a more favorable sRT outcome than MOR.

Humans

Meta-analysis of prostacyclin therapy for persistent pulmonary hypertension with congenital diaphragmatic hernia.

OBJECTIVE: To evaluate the efficacy and safety of prostacyclin in the treatment of persistent pulmonary hypertension in congenital diaphragmatic hernia. METHODS: A systematic literature search was conducted in four main databases (PubMed, Web of Science, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL). The protocol was registered in advance in the International Prospective of Systematic Reviews (CRD420261325458). RESULTS: A total of nine studies were included involving a total of 7009 infants in this systematic review and meta-analysis. GRADE assessment revealed substantial heterogeneity in the quality of evidence across outcomes, with most outcomes rated very low quality and only one rated moderate quality. Studies were performed meta-analysis, which showed the use of prostacylin resulted a statistically significant decrease in the OI compared to the control group (Mean Difference (MD), 9.34; I2 0%; p < 0.00001), no statistically significant in mortality (OR, 0.83; I2 84%; p = 0.70), ECMO (OR = 4.9; I2 98%; p = 0.27), BNP (std MD, 6.98; I2 98%; p = 0.31), FiO2 (SMD = 8.0;, I2 64%; p = 0.11), Systolic orientation of IVS curvature (SMD = 0.69; I2 97%; p = 0.32), Diastolic orientation of IVS differences (MD = 0.62; I2 93% p = 0.26). After applying the Hartung-Knapp adjustment, with the exception of BNP, the pooled effects of the other outcomes were not statistically significant, and there was high heterogeneity in measures such as ECMO and ventricular septal curvature. CONCLUSION: In conclusion, this meta-analysis has confirmed that prostacyclin may temporarily improve oxygenation. However, after applying the Hartung-Knapp adjustment, with the exception of BNP, the pooled effects of the other outcomes were not statistically significant, and there was high heterogeneity in measures such as ECMO and ventricular septal curvature. Further validation through high-quality studies are still needed. TRIAL REGISTRATION: PROSPERO: CRD420261325458.

Humans

Induction Paclitaxel-Cisplatin-Capecitabine for Nasopharyngeal Carcinoma.

BACKGROUND: We previously reported higher failure-free survival (FFS) with induction paclitaxel, cisplatin, and capecitabine (TPC) compared with cisplatin and fluorouracil (PF) in high-risk locoregionally advanced nasopharyngeal carcinoma (LA-NPC). We now report 5-year FFS, with prespecified secondary outcomes. METHODS: In this multicenter, randomized trial, patients with high-risk LA-NPC (T4N0-2M0 or TanyN3M0) received two 21-day cycles of induction chemotherapy with TPC or PF, followed by concurrent chemoradiotherapy. The primary endpoint was FFS; secondary endpoints included distant metastasis-free, locoregional relapse-free, and overall survival (OS), tumor response, and safety. RESULTS: Among 238 patients (TPC, n=118; PF, n=120), with median follow-up of 89.1 months, 5-year FFS was 77.6% in the TPC group and 62.9% in the PF group (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.34-0.82). At 5 years, distant metastasis-free survival was 87.8% in the TPC group and 78.8% in the PF group (HR, 0.51; 95% CI, 0.28-0.95); locoregional relapse-free survival was 92.0% and 82.1%, respectively (HR, 0.43; 95% CI, 0.21-0.88); and OS was 89.6% and 82.2%, respectively (HR, 0.51; 95% CI, 0.27-0.95). Among patients with pretreatment Epstein-Barr virus (EBV) DNA <3000 copies/ml, 5-year OS was 92.3% in the TPC group and 84.4% in the PF group. Among those with higher EBV DNA levels, rates were 84.2% in TPC group and 81.1% in PF group. Grade 3 or 4 adverse events occurred in 68 patients (57.6%) receiving TPC and 79 patients (65.8%) receiving PF. Treatment adherence was similar in the two groups. CONCLUSIONS: Among patients with high-risk LA-NPC, TPC induction chemotherapy was associated with higher 5-year FFS than PF. (Funded by National Natural Science Foundation of China and State Key Laboratory of Respiratory Disease; ClinicalTrials.gov number, NCT02940925.).

Humans

Human-Centered Workspace Optimization: A 2 &#xd7; 2 Factorial Study of Adjustable Furniture and Indoor Environmental Quality.

Small workspaces function as integrated systems, yet ergonomic furniture and indoor environmental conditions are usually evaluated separately. A six-site, assessor-blinded, randomized 2 &#xd7; 2 factorial controlled study was conducted of two multicomponent packages-adjustable furniture and optimized indoor environmental quality (IEQ)-among 240 office workers for four weeks. Each group included 60 participants. Overall comfort in week 4 was highest for both packages (5.62 &#xb1; 0.53 versus 3.99 &#xb1; 0.60 with fixed furniture and basic IEQ). In a site-adjusted factorial model with HC3 robust standard errors, the adjustable-furniture effect was 0.86 points (95% confidence interval [CI], 0.62-1.09), the optimized-IEQ effect was 0.34 points (95% CI, 0.12-0.55), and their interaction was 0.44 points (95% CI, 0.14-0.74). Adjustable furniture improved postural comfort and reduced neck and lower back discomfort; optimized IEQ improved environmental comfort; both packages improved perceived productivity, satisfaction, and fatigue. The task-accuracy interaction did not remain significant after false-discovery-rate adjustment, and exploratory mediation and spline analyses did not support indirect or nonlinear effects. These results support coordinated ergonomic and environmental implementation while preserving distinct outcome pathways.

Interior Design and Furnishings

Air Pollution and Heat Impacts on Respiratory Morbidity and Mortality Outcomes in Africa: A Systematic Review Towards a Meta-analysis.

PURPOSE OF THE REVIEW: This review synthesised evidence on associations between air pollution and respiratory morbidity in Africa. Following PRISMA guidelines, we systematically searched PubMed, ScienceDirect and Elicit for case-control studies published between 2015 and 2025. RECENT FINDINGS: Thirteen studies from ten African countries reported pollutant levels far exceeding WHO guidelines. Indoor PM&#x2082;.&#x2085; in biomass-using homes ranged from 96 to 177&#xa0;&#xb5;g/m&#xb3;, and ambient PM&#x2082;.&#x2085; reached 259&#xa0;&#xb5;g/m&#xb3;. Nitrogen oxides were consistently associated with reduced lung function in children, while household air pollution increased risks of under-five mortality and low birthweight. Associations with acute respiratory infections varied across settings. Vulnerability was greatest among young children, those with airway hyperresponsiveness, and households with poor ventilation. Only three studies included temperature, and none examined heat-respiratory interactions. Across African case-control studies, particulate matter and household air pollution remain consistently linked to adverse respiratory outcomes, highlighting urgent needs for cleaner fuels, improved ventilation, and stronger evidence on combined pollution and heat exposures.

Humans

Health risk assessment of inorganic arsenic: an umbrella review.

Inorganic arsenic (iAs) is a toxic environmental pollutant linked to serious health risks, prompting global regulatory efforts. This study identifies major health conditions associated with iAs exposure using text network analysis, and assesses health risk assessments through an umbrella review and dose-response analysis. It synthesizes previous systematic reviews to offer a broader perspective on iAs-related health effects. An optimized text network analysis-based search strategy was applied across multiple databases to identify relevant systematic reviews. An umbrella review framework was employed to synthesize and reinterpret findings across systematic reviews. The methodological quality of included systematic reviews was assessed using the A MeaSurement Tool to Assess systematic Reviews 2 tool. Extracted data on study characteristics, exposure levels, and risk estimates were analyzed to evaluate the dose-response relationship between iAs exposure and health outcomes. From 922 systematic reviews, 36 were included and categorized into 10 health condition groups. For example, seven SRs found a significant dose-response relationship between iAs and bladder cancer, with one systematic review reporting relative risks of 2.70, 4.20, and 5.80 at 10, 50, and 150&#x202f;&#xb5;g/L, respectively. Individual study analysis further showed that each 10&#x202f;&#xb5;g/L increase in iAs raised bladder cancer risk by 3.11&#x202f;% (p=0.003). iAs exposure is associated with hypertension, diabetes, cardiovascular disease, and adverse fetal outcomes. Dose-dependent increases in bladder cancer, lung cancer, and hypertension risks were observed. These findings support more precise health risk assessments and regulatory strategies.

Humans

Coordinated use of three homocysteine methyltransferases supports l-methionine biosynthesis and environmental adaptation among plant-associated bacteria.

Plant pathogens colonize multiple plant-associated habitats throughout their life cycle, encountering distinct nutrient conditions and microbial communities. l-methionine is required for bacterial growth and environmental adaptation. However, how plant pathogens coordinate l-methionine biosynthetic pathways to adapt to different plant-associated environments remains poorly understood. Here, using the plant pathogen Xanthomonas campestris pv. campestris strain XC1 as a model, we show that three homocysteine methyltransferase pathways allow XC1 to catalyze the final step of l-methionine biosynthesis using different methyl donors and cofactors under different environmental conditions. Bioinformatic and transcriptional analyses identified three homocysteine methyltransferase-associated operons in XC1, mesMXD, mmuPM, and metHRHaHb, corresponding to the MesD-, MmuM-, and MetHaHb-dependent pathways, respectively. MesD uses an endogenously synthesized methyl donor and functions as the dominant homocysteine methyltransferase under l-methionine-limiting conditions, supporting bacterial growth, intracellular l-methionine accumulation, and full virulence. Furthermore, MmuM enables XC1 to use plant-derived S-methylmethionine for l-methionine biosynthesis, whereas MetHaHb enables XC1 to use vitamin B12 supplied by a neighboring bacterium for l-methionine biosynthesis in co-culture. Expression analyses showed that mesMXD was the only homocysteine methyltransferase-associated operon that responded to l-methionine availability, and its expression also decreased when S-methylmethionine- or vitamin B12-dependent pathways supported l-methionine biosynthesis. Comparative genomic analysis further showed that the three-homocysteine methyltransferase configuration is conserved in Xanthomonas and is also present in other plant-associated bacteria. Together, these findings show that a plant pathogen can coordinate endogenous, plant-derived, and microbially supported homocysteine methyltransferase pathways to maintain l-methionine biosynthesis, providing a metabolic strategy for adaptation to plant-associated environments.

Methionine

Urban Design Quality and Clinical Mental Health: A Systematic Review.

ObjectivesThis systematic review synthesizes empirical evidence on core urban design dimensions that affect clinical mental health outcomes and examines how environmental exposures mediate or moderate these relationships.BackgroundUrban design has increasingly been recognized as a determinant of psychological well-being, yet a standardized framework to evaluate its mental health impact remains underdeveloped.MethodsFollowing PRISMA 2020 guidelines, we systematically reviewed 19 quantitative empirical studies published through January 2025, examining relationships between outdoor urban design features and validated clinical mental health indicators across four major databases.ResultsFindings reveal that urban design influences clinical mental health outcomes (depression, anxiety, stress, cognitive decline) through two objective spatial scales: street-level features (imageability, enclosure, human scale, complexity) and neighborhood environments (land use mix, density, green infrastructure). Environmental exposures (traffic, noise, air pollution) operate as perceptual and experiential mechanisms that mediate or moderate the mental health effects of these spatial design features.ConclusionsWe propose an integrated three-domain conceptual framework distinguishing objective spatial design scales from subjective exposure mechanisms. This framework provides evidence-based guidance for urban planners and policymakers toward creating mentally healthier urban environments.

Humans

Engineering copper ferrite (CuFe2O4) nanocomposites for enhanced eco-friendly photocatalysis: a systematic critical review on mechanisms, performance, and environmental applications.

Water pollution caused by organic and inorganic contaminants, particularly dyes and pharmaceuticals, represents a major environmental challenge. Advanced oxidation processes based on photocatalysts have emerged as efficient and sustainable approaches for water and wastewater treatment. Copper ferrite (CuFe2O4) is considered a promising photocatalyst owing to its narrow bandgap, visible-light activity, chemical stability, and magnetic properties. Despite extensive experimental investigations, a comprehensive systematic comparison of CuFe2O4-based photocatalysts under diverse operational conditions has remained limited. In this study, a systematic review following PRISMA guidelines was conducted using studies published between January 2014 and November 2025 indexed in Scopus, PubMed, Web of Science, and ScienceDirect. From an initial pool of 397 studies, 98 articles met the inclusion criteria. Key parameters&#xa0;-&#xa0;including pollutant type, pH, catalyst dosage, initial pollutant concentration, irradiation time, light source, and degradation efficiency&#xa0;-&#xa0;were quantitatively compared to identify performance trends and operational optima. The results demonstrate that CuFe2O4-based nanocomposites, particularly heterojunction, Z-scheme, and S-scheme architectures combined with TiO2, g-C3N4, graphene, and metal oxides, achieve high degradation efficiencies (often >90&#x202f;%) for a wide&#xa0;range of organic pollutants and selected inorganic contaminants (e.g., Cr(VI)). Enhanced charge separation and suppressed electron-hole recombination were identified as the primary factors contributing to improved photocatalytic activity. In addition, the intrinsic magnetic properties of these&#xa0;nanocomposites enable facile catalyst recovery and reuse. In conclusion, CuFe2O4-based nanocomposites, especially those&#xa0;incorporating advanced heterojunction architectures, emerge as highly efficient and magnetically recoverable photocatalytic platforms for sustainable water and wastewater treatment, with strong potential for scalable implementation and real-wastewater applications.

Catalysis

Persistent cloaca without vaginal-common channel fistula: A Case series characterizing a rare phenotype.

INTRODUCTION: Persistent cloaca occurs in approximately 1 in 25,000 live births. Among patients with cloaca, the absence of a vaginal connection to the common channel represents a rare phenotype with distinct anatomic and management considerations. We describe the urologic, gynecologic, and surgical characteristics of this patient subset. METHODS: We performed a retrospective analysis of a single-institution cohort of patients with persistent cloaca managed at a quaternary-care children's hospital between 2019 and 2025. Patients were eligible if they underwent primary cloacal repair by our multidisciplinary team and met all three diagnostic criteria for absent vaginal-common channel fistula: no hydrocolpos on imaging, no identified vaginal opening on cystoscopy or cloacagram, and no visible lumen between m&#xfc;llerian and cloacal structures identified intraoperatively. RESULTS: Of 51 patients who underwent primary repair, 6 (12%) met criteria for absent vaginal-common channel fistula. All met criteria for VACTEGRLS association. Common channel length ranged from 1.1 to 7.0 cm and urethral length from 0.5 to 2.2 cm. Urologic anomalies were nearly universal: five patients (83%) had a solitary functional kidney and four (67%) had vesicoureteral reflux. All underwent posterior sagittal anorectoplasty (PSARP) for rectal repair with the common channel repurposed as the neourethra. Five (83%) underwent diagnostic laparoscopy during which the m&#xfc;llerian structures were examined but left in situ. At last follow-up (median 17.5 months, range 4-35 months), three patients (50%) had volitional voiding and three (50%) required assisted bladder emptying via vesicostomy or Mitrofanoff. CONCLUSION: Persistent cloaca without a vaginal-common channel fistula represents a rare but clinically distinct phenotype characterized by severe urologic anomalies. Recognition of this phenotype is essential for surgical planning and long-term urologic and gynecologic surveillance. Because there was no connection between the vagina and the urinary tract, delaying management of the m&#xfc;llerian structures did not adversely affect the urinary tract.

Humans

A systematic review of human avoidance learning: Cognition, computation, and methods.

Avoidance behaviour is fundamental for survival but can become maladaptive in clinical conditions. A large body of literature has accumulated on the dynamics of human avoidance learning. However, current theories and overviews do not provide an exhaustive account of this evidence. In this systematic review, we identify N = 116 studies on human avoidance learning. We analyse these studies with the goal of distilling robust empirical phenomena as a basis for theory-building, and examine their diagnostic value in differentiating between competing theories. We find that the evidence is difficult to reconcile with foundational two-factor and classical safety-signal accounts, and most strongly supports expectancy- and inference-based views, in which avoidance responses are selected with respect to represented consequences. At the same time, no current framework provides a complete account of the evidence: several findings point to an additional role for operant valuation, Pavlovian influences, and contextual or latent-state control over the expression of avoidance. Methodologically, we observe that the problem setting in the most common experimental paradigms is radically simpler than real-world avoidance and therefore unlikely to expose the limits of inferential or reflective mechanisms. Consequently, we argue that paradigms with greater computational demands and more realistic action affordances are required to identify the mechanisms underlying avoidance learning. Collectively, these insights provide a foundation for theoretical refinement, computational modelling, and methodological innovation, with implications for advancing interventions targeting maladaptive avoidance.

Humans

Metabolic Stress Testing Reveals Persistent Lipid-Handling Dysfunction in Women With Polycystic Ovary Syndrome Despite Exercise Training.

AIM: Polycystic ovary syndrome (PCOS) is associated with insulin resistance and metabolic dysfunction, yet baseline metabolomic studies show inconsistent findings. We investigated whether metabolic abnormalities in PCOS emerge under physiological stress and how these responses are modified by exercise training. MATERIALS AND METHODS: Twelve women with PCOS and 10 controls completed hyperinsulinaemic-euglycaemic clamps with randomised saline or lipid infusion, before and after 8&#x2009;weeks of supervised exercise. Plasma metabolomics (163 metabolites) were measured at baseline, post-infusion and post-clamp. Linear mixed-effects models assessed Group&#x2009;&#xd7;&#x2009;Timepoint&#x2009;&#xd7;&#x2009;Intervention interactions. RESULTS: No baseline metabolite differences were observed between groups. A significant three-way interaction (p&#x2009;=&#x2009;0.008) indicated condition-dependent trajectory divergence. Post hoc analysis revealed a specific divergence during post-exercise lipid challenge (p&#x2009;=&#x2009;0.048). Women with PCOS showed reduced suppression of ether-linked phosphatidylcholines during insulin-stimulated lipid loading (PC ae C44:4, p&#x2009;=&#x2009;0.031), despite exercise-induced improvements in fitness and normalisation of amino acid profiles. Exploratory metabolite ratios suggested impaired substrate coordination under stress. CONCLUSIONS: Metabolic defects in PCOS are stress-dependent and not detectable at rest. Exercise training improves resting metabolism but reveals persistent impairment in adaptive lipid handling during combined insulin and lipid challenges, suggesting impaired coordination of substrate supply during metabolic stress. TRIAL REGISTRATION: ClinicalTrials.gov identifier: ISRCTN42448814.

Humans

Sex-stratified mortality trends in preterm birth complications in Sierra Leone: progress, persistence, and equity implications.

BACKGROUND: Preterm birth complications remain a leading cause of neonatal mortality in Sierra Leone, despite recent health system gains. Evidence on long-term sex-specific disparities in mortality due to preterm birth complications is limited, constraining equitable neonatal care planning. OBJECTIVE: To examine two&#x2011;decade trends in sex&#x2011;stratified mortality from preterm birth complications using standardized equity indicators. METHODS: We conducted a retrospective longitudinal analysis of sex-disaggregated mortality estimates from the World Health Organization (WHO) Global Health Estimates (GHE), accessed through the WHO Health Equity Assessment Toolkit (HEAT), Built-in Database Edition (Version 6.0). Mortality rates per 100,000 population were extracted for 2001, 2006, 2011, 2016, and 2021. Inequality was assessed using absolute difference (D), relative ratio (R), population attributable risk (PAR), and population attributable fraction (PAF). RESULTS: Mortality declined substantially between 2001 and 2021 for both males (85.1-49.3 per 100,000) and females (71.2-39.9 per 100,000). Male mortality remained consistently higher across all years, with relative ratios indicating approximately 20-25% excess mortality among male neonates. Absolute inequalities narrowed modestly over time, whereas relative inequalities remained largely unchanged. PAR and PAF remained close to zero throughout the study period. Wider uncertainty intervals in earlier years reflected limited empirical data availability. CONCLUSION: Although preterm mortality declined over two decades, a persistent male disadvantage remained in Sierra Leone. These findings highlight the importance of integrating sex-disaggregated equity monitoring into neonatal policies and programmes. Future research should evaluate strategies to reduce the persistent excess mortality among male neonates while sustaining overall improvements in neonatal survival and progress toward Sustainable Development Goal 3.2.

Humans

Depth-dependent multi-kingdom microbial interactions and biogeochemical cycling genes in eutrophic shallow lake sediments.

Microorganisms are pivotal to lake ecosystem biogeochemical cycles, yet existing research often focuses on single microbial kingdoms or surface sediments, neglecting multi-kingdom interactions and depth-resolved dynamics. To address these gaps, we used metagenomic sequencing to characterize microbial communities and their functional associations across overlying water and 0-45 cm sediments in four shallow lakes of the middle Yangtze River basin, China. Despite increasing bacterial and fungal diversity with depth, the 0-9 cm surface sediments exhibited the strongest multi-kingdom network connectivity and the greatest microbial stability. Functional genes exhibited clear depth-dependent patterns: nitrogen cycling genes, including those involved in dissimilatory nitrate reduction to ammonium, were most enriched in the upper 0-9 cm of sediment; methane cycling genes were positively correlated with depth; phosphorus cycling genes and some sulfur cycling genes, such as assimilatory sulphate reduction, declined with depth. Sediment microbial assembly was dominated by deterministic processes, in which the vertical distribution of functional genes was primarily dictated by heavy metals and conventional environmental indicators. These findings highlight depth-specific multi-kingdom microbial interactions and their associations with biogeochemical cycling, advancing lacustrine microbial ecology understanding and providing references for lake conservation under environmental change.

Lakes

Detoxifying biotransformation of chloramphenicol by Exiguobacterium sp. CAP4 and its bioaugmentation of chloramphenicol biodegradation in simulated wastewater.

The extensive use of chloramphenicol (CAP) in livestock leads the accumulation of CAP in livestock manures, threatening environmental and human health. Therefore, eliminating or reducing CAP concentration in manures before its re-utilization and application through microbial remediation is necessary. Exiguobacterium sp. CAP4, isolated from the plastisphere in duck manures, was capable of degrading CAP with the biodegradation efficiency of 97.8 % at initial CAP concentration of 5 mg/L within 4 days. A total of twenty-four biotransformation products were determined, including two novel transformation products, TP166 and TP203, enriched the integrity of CAP biodegradation pathways. Furthermore, the biotransformation process was proposed as a detoxifying process through biotransformation products toxicity evaluation. Notably, Exiguobacterium sp. CAP4 successfully colonized in the cow manures after inoculation, and bioaugmented the biodegradation of CAP in virgin cow manures. This study significantly extended our understanding of the CAP biotransformation fate, and provided a promising bacterial strain for bioremediation of CAP containing wastewater in situ.

Chloramphenicol

Influence of microplastics on microalgal performance during wastewater polishing.

Microplastics (MPs) are emerging contaminants that are increasingly accumulating in aquatic ecosystems due to excessive anthropogenic activity and insufficient mitigation strategies, posing serious environmental and public health risks. Their impact on wastewater (WW) treatment processes remains poorly understood. This study evaluated the effects of five MPs commonly found in WW - polypropylene, polystyrene, polyamide, low-density polyethylene, and high-density polyethylene - on the physiology and bioremediation performance of the microalga Chlorella vulgaris in synthetic WW (SWW). Metabolic responses were assessed via esterase activity and intracellular reactive oxygen species (ROS), while nitrogen (N), phosphorus (P), and glucose removal were monitored to evaluate bioremediation efficiency. MPs inhibited esterase activity and elevated ROS levels, indicating oxidative stress. Nevertheless, C. vulgaris maintained a high bioremediation capacity (> 75 % N, > 60 % P, and > 70 % for glucose). Environmental conditions modulated microalga response to MPs exposure. Under N-limited conditions, C. vulgaris exhibited enhanced nutrient uptake and biomass production, but a 12 h/12 h light/dark photoperiod reduced N removal but stimulated glucose consumption via heterotrophic metabolism. In contrast, C-limited conditions exacerbated oxidative stress and compromised nutrient removal, resulting in residual concentrations exceeding legal limits. These findings highlight that environmental factors can either mitigate or exacerbate the physiological stress induced by MPs, ultimately affecting WW polishing. This work provides a comprehensive insight into the cellular and metabolic effects of MPs on microalgae and supports C. vulgaris as a resilient and sustainable approach for nutrient and carbon removal in MP-contaminated WW systems.

Microalgae

Cooperative anaerobic catabolism of chlorinated organic compounds: implications for sustainable bioremediation.

Biodegradation research historically followed a reductionist approach focused on axenic (pure) cultures capable of catabolizing the specific contaminant(s) of interest. While this approach has substantially advanced our understanding of the microbiology, physiology, biochemistry, and genetics of contaminant degradation under laboratory conditions, it does not capture the complexity of natural and engineered environments. During in situ bioremediation, microbiomes are exposed to mixtures of contaminants, and microbial interactions profoundly influence contaminant transformation and fate. In anoxic environments, degradation of chlorinated compounds is often sustained by metabolic cooperation among taxonomically and physiologically distinct microorganisms. Through the exchange of metabolites such as hydrogen, formate, acetate, and other nutrients, microbial populations establish interdependent networks that overcome thermodynamic and physiological constraints, enabling self-sustaining systems of contaminant transformations that would be inefficient or impossible with individual organisms. We highlight examples of microbial interactions that underpin anaerobic catabolism of chlorinated contaminants, including systems resulting in self-sustained anaerobic bioremediation.

Biodegradation, Environmental