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Due to the development and utilization of nuclear energy, the safe disposal of nuclear waste needs to be urgently addressed. In recent years, the utilization of microorganisms' adsorption capacity to dispose of radioactive waste has received increasing attention. When compared with conventional disposal methods, microbial adsorption exhibits the characteristics of high efficiency, low cost, and no secondary pollution. In the long term, microbial biomass shows significant promise as specific chemical-binding agents. Optimization of biosorption conditions, identification of rare earth element binding sites, and studies on the sorption capacities of immobilized cells provide compelling reasons to consider biosorption for industrial applications in heavy metal removal from solutions. However, the interaction mechanism between microorganisms and radioactive nuclides is very complex. This mini-review briefly provides an overview of the preparation methods, factors affecting the adsorption capacity, and the mechanisms of microbial adsorbents.
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Autism Spectrum Disorder (ASD), a complex neurodevelopmental disorder marked by social communication deficits and repetitive behaviors, may see symptom amelioration through gut microbiota modulation. This study investigates the effects of a synbiotic - specifically a probiotic amplified by prebiotic supplementation - on ASD-like mouse model's social deficiencies. This model was established via valproic acid injection into pregnant females. Post-weaning, male progeny received daily synbiotic treatment, a combination of Lactobacillus reuteri (L. reuteri) and inulin, for four weeks. Results indicated that the synbiotic rectified social impairments and attenuated inflammatory cytokine expressions in the brain. Moreover, synbiotic intervention protected gut barrier integrity and altered the gut microbiota composition, enhancing the butyrate-producing Bifidobacterium abundance. The synbiotic elevated metabolites such as butyrate and 3-hydroxybutyric acid (3-HB), alongside upregulated genes associated with 3-HB synthesis in the colon and liver, and brain receptors. Conclusively, the synbiotic combination of L. reuteri and inulin mitigated ASD-related social impairments, partially via their regulatory effect on the gut-brain axis.
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Trastorno del Espectro Autista , Limosilactobacillus reuteri , Simbióticos , Femenino , Masculino , Ratones , Animales , Inulina , Eje Cerebro-Intestino , Trastorno del Espectro Autista/terapia , ButiratosRESUMEN
A large amount of nuclear waste produced in the process of nuclear energy utilization has always been a key problem to be solved urgently for nuclear safety. At present, "deep geological disposal" is a feasible method and generally accepted by many countries. The oxygen content in the near field environment of the waste container will decrease to anaerobic conditions, and hydrogen will permeation into the internal materials of container for a long time. Hydrogen evolution corrosion may cause a risk of hydrogen embrittlement. The harm of hydrogen embrittlement in metal container is far more severe than predictable uniform corrosion. It is a research hotspot that the microorganisms impact on the corrosion behavior of container materials in the deep geological environment. Microbial corrosion in deep geological environments can be divided into two types: aerobic microbial corrosion and anaerobic microbial corrosion. There is a type of hydrogen consuming microorganism in the natural environment that uses the oxidation of hydrogen as the energy for its life activities. This provides a new approach for us to study reducing the hydrogen embrittlement sensitivity of nuclear waste container materials.
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SCOPE: Excessive iron contributes to oxidative damage and cognitive decline in Alzheimer's disease. Sesamol, a compound in sesame oil that exhibits both anti-inflammatory and neuroprotective properties, is examined in this study for its ability to alleviate cognitive impairments in iron overload mice model. METHODS AND RESULTS: An iron overload model is established by intraperitoneally injecting dextran iron (250 mg kg-1 body weight) twice a week for 6 weeks, while sesamol (100 mg kg-1 body weight) is administered daily for the same length of time. The results demonstrate that sesamol protects spatial working memory and learning ability in iron overload mice, and inhibits neuronal loss and brain atrophy induced by iron overload. Moreover, sesamol significantly decreases interleukin-6 and malondialdehyde, and increases glutathione peroxidase 4 in the brains of iron overload mice. Additionally, sesamol maintains iron homeostasis in the brain by regulating the expressions of transferrin receptors, divalent metal transporter 1, and hepcidin, and reducing iron accumulation. Furthermore, sesamol suppresses disturbed systemic iron homeostasis and inflammation, particularly liver interleukin-6 expression. CONCLUSION: These findings suggest that sesamol may be effective in mitigating neuroinflammatory responses and cognitive impairments induced by iron overload, potentially through its involvement in mediating the liver-brain axis.
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Disfunción Cognitiva , Sobrecarga de Hierro , Ratones , Animales , Interleucina-6 , Disfunción Cognitiva/tratamiento farmacológico , Disfunción Cognitiva/etiología , Inflamación/tratamiento farmacológico , Benzodioxoles/farmacología , Sobrecarga de Hierro/complicaciones , Sobrecarga de Hierro/tratamiento farmacológico , Peso Corporal , HierroRESUMEN
BACKGROUND: The World Health Organization (WHO) has proposed healthy aging framework, supposing that intrinsic capacity (IC), environment and their interaction may have influence on functional ability (FA). It was still unclear how the IC level and age-friendly living environment impact on FA. This study aims to confirm the relationship between the IC level and age-friendly living environment with FA, especially in older adults with low IC. METHODS: Four hundred eighty-five community-dwelling residents aged ≥ 60 years were enrolled. IC constructed by locomotion, cognition, psychological, vitality, and sensory domains was assessed using full assessment tools recommended by WHO. Age-friendly living environment was measured with 12 questions adapted from the spatial indicators framework of age-friendly cities. FA was assessed using activities of daily living (ADL) and one question about mobile payment ability. Multivariate logistic regression was used to explore the association between IC, environment and FA. The influence of the environment on electronic payment and ADL under the IC layer was assessed. RESULTS: Of 485 respondents, 89 (18.4%) had ADL impairment, and 166 (34.2%) had mobile payment function impairment. Limited IC (odds ratio [OR] = 0.783, 95% confidence interval [CI] = 0.621-0.988) and poor environment (OR = 0.839, 95% CI = 0.733-0.960) were associated with mobile payment ability impairment. Our results suggested that a supportive age-friendly living environment influenced FA was more prominent in older adults with poor IC (OR = 0.650, 95% CI = 0.491-0.861). CONCLUSIONS: Our results confirmed IC and the environment had an impact on mobile payment ability. The relationship between environment and FA showed differences according to IC level. These findings suggest that an age-friendly living environment is important to maintain and enhance elders' FA, especially in those with poor IC.
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Actividades Cotidianas , Envejecimiento Saludable , Humanos , Anciano , Vida Independiente , Estudios Transversales , Persona de Mediana Edad , Anciano de 80 o más AñosRESUMEN
PURPOSE: Studies have shown an average postoperative hidden blood loss (HBL) of 473.29 ml and an average Hb loss of 16.71 g/l after intramedullary nailing. Reducing HBL has become a primary consideration for orthopaedic surgeons. METHODS: Patients with only tibial stem fractures who visited the study clinic between December 2019 and February 2022 were randomized into two groups using a computer-generated form. Two grams of tranexamic acid (TXA) (20 ml) or 20 ml of saline was injected into the medullary cavity before implantation of the intramedullary nail. On the morning of the surgery, as well as on days one, three and five after surgery, routine blood tests and analyses of CRP and interleukin-6 were completed. The primary outcomes were total blood loss (TBL), HBL, and blood transfusion, in which the TBL and HBL were calculated according to the Gross equation and the Nadler equation. Three months after surgery, the incidence of wound complications and thrombotic events, including deep vein thrombosis and pulmonary embolism, was recorded. RESULTS: Ninety-seven patients (47 in the TXA group and 50 in the NS group) were analyzed; the TBL (252.10 ± 10.05 ml) and HBL (202.67 ± 11.86 ml) in the TXA group were significantly lower than the TBL (417.03 ± 14.60 ml) and HBL (373.85 ± 23.70 ml) in the NS group (p < 0.05). At the three month postoperative follow-up, two patients (4.25%) in the TXA group and three patients (6.00%) in the NS group developed deep vein thrombosis, with no significant difference in the incidence of thrombotic complications (p = 0.944). No postoperative deaths or wound complications occurred in either group. CONCLUSIONS: The combination of intravenous and topical TXA reduces blood loss after intramedullary nailing of tibial fractures without increasing the incidence of thrombotic events.
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Antifibrinolíticos , Fijación Intramedular de Fracturas , Ácido Tranexámico , Trombosis de la Vena , Humanos , Ácido Tranexámico/uso terapéutico , Antifibrinolíticos/efectos adversos , Pérdida de Sangre Quirúrgica/prevención & control , Fijación Intramedular de Fracturas/efectos adversos , Hemorragia Posoperatoria/epidemiología , Hemorragia Posoperatoria/etiología , Hemorragia Posoperatoria/prevención & control , ExsanguinaciónRESUMEN
To evaluate the effect of aging time on the quality of tangerine peel (TP) from the perspective of TP polysaccharide (TPP), five polysaccharide samples with different aging times named TPP-0/1/5/10/15 were prepared. Under the conditions of pH 0.5, solid-liquid ratio 1:25 and 80 °C, the TPPs extraction yield ranged from 20.35% to 27.68%. Compared with TPP-0, TPP-1/5/10/15 possesses low molecular weight (Mw) and high methoxy group content. In addition, TPP-15 had the most potent antioxidant activity. And the content of acidic polysaccharides in TPPs was negatively correlated with neutral polysaccharides during aging. Based on the analysis of 16srDNA, the dominant bacteria (Brevundimonas and Pseudomonas) in TP-10 might be critical flora to affect TP quality. This study provided basic information on the relationship between the TPPs and aging time, which could promote a new view to develop TP, and shorten the aging time during TP production.
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Antioxidantes , Polisacáridos , Antioxidantes/química , Bacterias , Frutas/química , Polisacáridos/química , Citrus sinensis/microbiologíaRESUMEN
Human communication not only involves the need to switch between the modalities of speaking and listening, but for bilinguals, it can also involve switching between languages. It is unknown as to whether modality and language switching share underlying control mechanisms or whether one type of switching affects control processes involved in the other. The present study uses behavioral and fMRI measures to examine neural circuits of control during communicative situations that required Chinese-English bilinguals to switch between modalities and their two languages according to associated color cues. The results showed that for both language and modality control, similar brain regions were recruited during speech production and comprehension. For modality control, the specific control processes partly depended on the corresponding modality. Finally, switching between modalities appears to exert more influence on language control in production compared to comprehension. These findings offer a first detailed characterization of the neural bases involved in control mechanisms in bilingual communication.
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Imagen por Resonancia Magnética , Multilingüismo , Humanos , Mapeo Encefálico , Lenguaje , EncéfaloRESUMEN
PURPOSE: To investigate the efficacy and safety of intravenous tranexamic acid (IV-TXA) in patients undergoing intertrochanteric fracture surgery. METHODS: A total of 122 patients were included in this double-blinded trial and equally randomized to receive 1 g of IV-TXA or normal saline 10 min before incision and 3 h later. The primary efficacy outcome was calculated hidden blood loss (HBL). The secondary efficacy outcome was allogeneic erythrocyte transfusion rate during hospitalization. Safety outcome was a composite of thromboembolic events including deep venous thrombosis (DVT) up to 90 days. A meta-analysis combining this study with previous randomized controlled trials in hip fracture surgery (total sample size: 1112 patients) was also conducted. RESULTS: The mean HBL in TXA group (640.96 ± 421.63 ml) was significantly lower than that in placebo group (1010.11 ± 398.96 ml, P < 0.001). The rate of erythrocyte transfusions was 29.5% in TXA group and 60.7% in placebo group (P = 0.001). The incidence of thromboembolic events at 90 days was 4.9% in TXA group and 1.6% in placebo group (P = 0.619). The updated meta-analysis showed that IV-TXA significantly reduced erythrocyte transfusion in hip fracture surgery (risk ratio 0.60, 95% confidence intervals 0.53-0.68), and IV-TXA caused no increased risk of thromboembolic events (risk difference 0.01, 95% confidence intervals - 0.02-0.04). CONCLUSION: IV-TXA could effectively reduce the HBL and allogeneic erythrocyte transfusion requirements in patients undergoing intertrochanteric fracture surgery without an increase of thromboembolic events including DVT. TRIAL REGISTRATION: Clinical trials: safety and efficiency of tranexamic acid in hip fracture patients. Date of registration: August 31, 2018. TRIAL REGISTRATION NUMBER: ChiCTR1800018110.
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Pérdida de Sangre Quirúrgica , Fracturas de Cadera , Ácido Tranexámico , Antifibrinolíticos/efectos adversos , Pérdida de Sangre Quirúrgica/prevención & control , Fracturas de Cadera/cirugía , Humanos , Metaanálisis como Asunto , Ácido Tranexámico/efectos adversos , Resultado del TratamientoRESUMEN
The flexor carpi radialis brevis (FCRB) is a rare abnormal muscle of the distal forearm or wrist. Its incidence varies in different reports, which oscillating between 2-8%. This paper reports a case of FCRB found in the anatomy of the forearm. The abnormal muscle, which started from the facies volaris distal radii, occupies the terminus of pronator quadratus, and was observed with dysplasia in the pronator quadratus. We also reviewed the literature on FCRB anatomy, especially the surgical exposure of distal radius fractures and the clinical symptoms caused by FCRB. Knowledge of the anomalous muscles of the forearm and wrist can highly improve clinician's understanding of the disease during surgery and imaging examination, and reduce unnecessary trauma caused by misdiagnosis.
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BACKGROUND: Minimally invasive surgery is becoming increasingly common, but evidence of the advantages of the minimally invasive transpiriformis approach in total hip arthroplasty is limited. Therefore, our single-centre randomized controlled trial evaluated the benefits of this approach versus the posterolateral approach. METHODS: Forty-nine patients undergoing the minimally invasive transpiriformis approach and 57 patients undergoing the posterolateral approach total hip arthroplasty were analyzed. The operative time, length of hospital stay, incision length, and peri-operative data related to the surgery were recorded. In both groups, serum CRP, IL-6, HGb, Hct, MB, CK-MB, and CK levels, Harris hip scores, and VAS scores were recorded. RESULTS: Patients who underwent the minimally invasive transpiriformis approach had a smaller surgical incision (9.10 ± 0.94 vs. 15.56 ± 1.20 cm, P = 0.00) and shorter hospital stay (6.20 ± 1.54 vs. 12.26 ± 2.97 days, P = 0.00) than those who underwent the posterolateral approach. Serum levels of CRP, IL-6, MB, CK-MB, and CK were also lower. According to the Harris hip score, the minimally invasive transpiriformis group showed significant improvement at one week and one month after surgery. CONCLUSION: Compared to the posterolateral approach, the minimally invasive transpiriformis approach for total hip arthroplasty provided rapid functional recovery, elicited a significantly reduced post-operative inflammatory response, and caused less muscle damage.
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Artroplastia de Reemplazo de Cadera , Biología , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos , Tempo Operativo , Estudios Prospectivos , Resultado del TratamientoRESUMEN
AIM: To assess the attitudes of newly graduated nurses in China toward their work environment and identify the factors affecting their perception. BACKGROUND: Newly graduated nurses are the primary supply to cover the nursing shortage, but their stressful transition into clinical work has contributed to high turnover for decades. Although serving as a source of stress, the work environment can also be a source of support for new nurses. METHODS: A total of 2361 new nurses at 31 tertiary hospitals in 20 provinces were surveyed from June to November 2018, using the Chinese version of the Practice Environment Scale-Nursing Work Index. Basic information and their perception about work environment were collected. RESULTS: New nurses rated their work environment with an overall score of 84.67 (12.85). Multiple linear regression identified that education level, monthly income, hospital type and location, participation (or not) in standardized training programmes and having (or not) a mentor/preceptor were factors significantly associated with their perception of the work environment. CONCLUSION: The perception of newly graduated nurses in China was mainly positive overall. Nursing managers may take full advantage of factors affecting the perception of work environment to support newly graduated nurses better, to help their retention and transition.
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Enfermeras Administradoras , Enfermeras y Enfermeros , Estudios Transversales , Humanos , Reorganización del Personal , Encuestas y Cuestionarios , Lugar de TrabajoRESUMEN
BACKGROUND: To evaluate the role of high-resolution computed tomography (HRCT) in the diagnosis of 2019 novel coronavirus (2019-nCoV) pneumonia and to provide experience in the early detection and diagnosis of 2019-nCoV pneumonia. METHODS: Seventy-two patients confirmed to be infected with 2019-nCoV from multiple medical centers in western China were retrospectively analyzed, including epidemiologic characteristics, clinical manifestations, laboratory findings and HRCT chest features. RESULTS: All patients had lung parenchymal abnormalities on HRCT scans, which were mostly multifocal in both lungs and asymmetric in all patients, and were mostly in the peripheral or subpleural lung regions in 52 patients (72.22%), in the central lung regions in 16 patients (22.22%), and in both lungs with "white lung" manifestations in 4 patients (5.56%). Subpleural multifocal consolidation was a predominant abnormality in 38 patients (52.78%). Ground-glass opacity was seen in 34 patients (47.22%). Interlobular septal thickening was found in 18 patients, 8 of whom had only generally mild thickening with no zonal predominance. Reticulation was seen in 8 patients (11.11%), and was mild and randomly distributed. In addition, both lungs of 28 patients had 2 or 3 CT imaging features. Out of these 72 patients, 36 were diagnosed as early stage, 32 patients as progressive stage, and 4 patient as severe stage pneumonia. Moreover, the diagnostic accuracy of HRCT features combined with epidemiological history was not significantly different from the detection of viral nucleic acid (all P >0.05). CONCLUSIONS: The HRCT features of 2019-nCoV pneumonia are characteristic to a certain degree, which when combined with epidemiological history yield high clinical value in the early detection and diagnosis of 2019-nCoV pneumonia.
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In this study, P. kudriavzevii was isolated and identified as an effective antagonistic yeast, which could significantly inhibit the rotting rate, weight loss, and delay the color change, with no effect on total soluble solids (TSS), titratable acid (TA), or firmness during cherry tomato storage. High-throughput sequencing was used to survey the effect of P. kudriavzevii on fungal community throughout cold storage. The results showed that the biological succession of predominant pathogens was disrupted by P. kudriavzevii. The abundance of Botrytis and Alternaria was higher in the control than upon P. kudriavzevii treatment at 28 d, but some yeast genera such as Naganishia, Wickerhamomyces, and Cutaneotrichosporon at 14 d, Pichia and Sporidiobolus at 21 d, and Cystofilobasidium at 28 d, had relatively higher abundances in P. kudriavzevii treatments than the control. Oddly, as an antagonist agent, P. kudriavzevii was not the dominant population, indicating that altering the course of succession of the fungal community may be an effective mechanism of antagonistic yeast. Furthermore, the total network correlation analysis of fungal community revealed that the community development was more dependent on similarities in function than on taxonomic relationships.
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Antibiosis , Frutas/microbiología , Microbiota , Micobioma , Pichia/fisiología , Solanum lycopersicum/microbiología , Agentes de Control Biológico , Almacenamiento de Alimentos/métodosRESUMEN
INTRODUCTION: The efficacy and safety of intravenous (IV) tranexamic acid (TXA) during hip fracture surgery remain controversial. This meta-analysis aimed to assess the efficacy of IV-TXA administration during hip fracture surgery for reducing the transfusion requirement and blood loss as well as its safety regarding the risk of thrombolysis. MATERIALS AND METHODS: PubMed, EMBASE, Web of Science, and the Cochrane Library Database were systematically searched for randomized controlled trials (RCTs) that focused on the efficacy and safety of IV-TXA in patients during hip fracture surgery. The primary outcome was the transfusion requirement. Secondary outcomes included total blood loss (TBL), deep vein thrombosis (DVT), and total thromboembolic events (TTEs). Risk ratio (RR), risk difference (RD), and mean difference (MD) for dichotomous and continuous data outcomes were determined from the meta-analysis. Data were analyzed using Rev Man 5.3. RESULTS: Altogether, 11 RCTs were included (total sample size 892 patients). IV-TXA significantly reduced the transfusion requirement [RR 0.60, 95% confidence interval (CI) 0.38-0.93, P = 0.02] and TBL (MD 326.64 ml, 95% CI - 462.23 to - 191.06, P < 0.00001) vs. cosntrol group. IV-TXA caused no increased risk of DVT (RD 0.02, 95% CI - 0.01 to 0.04, P = 0.13) or TTEs (RD 0.02, 95% CI - 0.01 to 0.05, P = 0.12). CONCLUSION: Available evidence indicates that IV-TXA efficaciously reduces TBL and transfusion requirements during hip fracture surgery without significantly increasing the risk of TTEs including DVT.
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Pérdida de Sangre Quirúrgica/prevención & control , Transfusión Sanguínea/estadística & datos numéricos , Fijación de Fractura , Fracturas de Cadera/cirugía , Ácido Tranexámico/administración & dosificación , Administración Intravenosa , Antifibrinolíticos/administración & dosificación , Antifibrinolíticos/efectos adversos , Antifibrinolíticos/uso terapéutico , Fijación de Fractura/efectos adversos , Fijación de Fractura/métodos , Humanos , Cuidados Intraoperatorios/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del TratamientoRESUMEN
Nowadays, despite the easy fabrication and low cost of metal oxide gas sensors, it is still challenging for them to detect gases at low concentrations. In this study, resistance-matched p-type Cu2O and n-type Ga-doped ZnO, as well as p-type CdO/LaFeO3 and n-type CdO/Sn-doped ZnO sensors were prepared and integrated into p + n sensor arrays to enhance their gas-sensing performance. The materials were characterized by scanning electron microscopy, transmittance electron microscopy, and X-ray diffractometry, and gas-sensing properties were measured using ethanol and acetone as probes. The results showed that compared with individual gas sensors, the response of the sensor array was greatly enhanced and similar to the gas response product of the p- and n-type gas sensors. Specifically, the highly sensitive CdO/LaFeO3 and CdO/Sn-ZnO sensor array had a high response of 21 to 1 ppm ethanol and 14 to 1 ppm acetone, with detection limits of <0.1 ppm. The results show the effect of sensor array integration by matching the two sensor resistances, facilitating the detection of gas at a low concentration.
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Transformation from natural forests to planted forests in tropical regions is an expanding global phenomenon causing major modifications of land cover and soil properties, e.g. soil organic carbon (SOC). This study investigated accumulations of POPs in soils under eucalyptus and rubber forests as compared with adjacent natural forests on Hainan Island, China. Results showed that due to the greater forest filter effect and the higher SOC, the natural forest have accumulated larger amounts of POPs in the top 20 cm soil. Based on correlation and air-soil equilibrium analysis, we highlighted the importance of SOC in the distribution of POPs. It is assumed that the elevated mobility of POPs in the planted forests was caused by greater loss of SOC and extensive leaching in the soil profile. This suggests that a better understanding of global POPs fate should take into consideration the role of planted forests.
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Monitoreo del Ambiente , Bosques , Éteres Difenilos Halogenados/análisis , Bifenilos Policlorados/análisis , Contaminantes del Suelo/análisis , Suelo/química , Carbono/análisis , China , IslasRESUMEN
Semivolatile persistent organic pollutants (POP) are bioaccumulative and toxic contaminants. Their global distribution depends on source distribution, atmospheric transport, degradation, and the exchange with ocean and land surfaces. Forests are crucial terrestrial reservoirs due to the commonly envisaged high capacity of their surface soils to store and immobilize airborne contaminants bound to soil organic matter. Our results show that POPs can be unexpectedly mobile in the soil of a tropical rainforest due to fast litter turnover (leading to rapid POP transfer to the subsoil) and leaching rates exceeding degradation rates especially for more hydrophobic congeners. Co-transport in association with leaching fine particulate and dissolved organic matter appears as a relevant driver of this PCB export. A markedly different distribution pattern is displayed in this soil in comparison to soils of colder environments with lower overall storage capacity. These findings show that biogeochemistry of organic matter degradation and weathering can influence POP soil fate. Because tropical forests represent 60% of the global terrestrial productivity, the highlighted dynamics might have an implication for the general distribution of these contaminants.
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Compuestos Orgánicos/análisis , Contaminantes del Suelo/análisis , Bosque Lluvioso , Suelo/química , Clima TropicalRESUMEN
The levels and distribution of polybrominated diphenylethers (PBDEs), novel brominated flame retardants (NBFRs) and Dechlorane Plus (DP) in soils and their dependence on environmental and anthropological factors were investigated in 159 soil samples from 30 background forested mountain sites across China. Decabromodiphenylethane (DBDPE) was the most abundant flame retardant (25-18,000 pg g(-1) and 5-13,000 pg g(-1) in O-horizon and A-horizon, respectively), followed by BDE 209 (nd-5900 pg g(-1) and nd-2400 pg g(-1) in O-horizon and A-horizon, respectively). FRs distributions were primarily controlled by source distribution. The distributions of most phasing-out PBDEs, DP isomers and TBPH were in fact correlated to a population density-based index used as proxy of areas with elevated usage and waste of FR containing products. High concentrations of some NBFRs were however observed in industrialized regions and FR manufacturing plants. Strongly positive correlations were observed between PBDEs and their replacement products suggesting similar emission pattern and environmental behavior. Exposure of mineral subsoils depended on precipitations driving leaching of FRs into the soil core. This was especially evident for some emerging BFRs (TBE, TBPH, and TBB etc.) possibly indicating potential for diffuse groundwater contamination.
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Retardadores de Llama/análisis , Bosques , Éteres Difenilos Halogenados/análisis , Contaminantes del Suelo/análisis , Suelo , China , Monitoreo del AmbienteRESUMEN
Organic and mineral soil horizons from forests in 30 mountains across China were analysed for polychlorinated biphenyl (PCB). Soil total organic carbon (TOC) content was a key determinant of PCB distribution explaining over 90% of the differences between organic and mineral soils, and between 30% and 60% of the variance along altitudinal and regional transects. The residual variance (after normalization by TOC) was small. Tri- to tetra-CB levels were higher in the South in relation to high source density and precipitation. Heavier congeners were instead more abundant at mid/high-latitudes where the advection pattern was mainly from long range transport. This resulted in a latitudinal fractionation opposite to theoretical expectations. The study showed that exposure to sources with different characteristics, and possibly accumulation/degradation trends of different congeners in soils being out-of-phase at different latitudes, can lead to an unsteady large scale distribution scenario conflicting with the thermodynamic equilibrium perception.