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1.
J Environ Sci (China) ; 147: 630-641, 2025 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-39003078

RESUMEN

Cadmium (Cd) and arsenic (As) co-contamination has threatened rice production and food safety. It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors. Mg-loaded biochar with outstanding adsorption capacity for As and Cd was used for the first time to remediate Cd/As contaminated paddy soils. In addition, the effect of zero-valent iron (ZVI) on grain As speciation accumulation in alkaline paddy soils was first investigated. The effect of rice straw biochar (SC), magnesium-loaded rice straw biochar (Mg/SC), and ZVI on concentrations of Cd and As speciation in soil porewater and their accumulation in rice tissues was investigated in a pot experiment. Addition of SC, Mg/SC and ZVI to soil reduced Cd concentrations in rice grain by 46.1%, 90.3% and 100%, and inorganic As (iAs) by 35.4%, 33.1% and 29.1%, respectively, and reduced Cd concentrations in porewater by 74.3%, 96.5% and 96.2%, respectively. Reductions of 51.6% and 87.7% in porewater iAs concentrations were observed with Mg/SC and ZVI amendments, but not with SC. Dimethylarsinic acid (DMA) concentrations in porewater and grain increased by a factor of 4.9 and 3.3, respectively, with ZVI amendment. The three amendments affected grain concentrations of iAs, DMA and Cd mainly by modulating their translocation within plant and the levels of As(III), silicon, dissolved organic carbon, iron or Cd in porewater. All three amendments (SC, Mg/SC and ZVI) have the potential to simultaneously mitigate Cd and iAs accumulation in rice grain, although the pathways are different.


Asunto(s)
Arsénico , Cadmio , Carbón Orgánico , Magnesio , Oryza , Contaminantes del Suelo , Suelo , Oryza/química , Cadmio/análisis , Cadmio/química , Carbón Orgánico/química , Contaminantes del Suelo/análisis , Arsénico/análisis , Suelo/química , Magnesio/química , Hierro/química , Restauración y Remediación Ambiental/métodos
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 326: 125223, 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39348738

RESUMEN

Cysteine, as a vital endogenous small molecule mercaptan, plays a crucial role in various physiological processes. The high sensitivity and selectivity of fluorescent probes provide a method to monitor cysteine, which is helpful to understand the mechanism of cysteine in physiological processes more comprehensively. However, the detection of cysteine can be interfered by other small molecule biothiols. Therefore, the design of fluorescent probe based on the structural characteristics and reactivity of cysteine has become research focus currently. Given the biological compatibilities, biological targets, the metabolic pathway of 3-hydoxythalidomide, and its unique fluorescent properties, herein, we have designed a chemodosimeter, 2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-4-yl acrylate, for the detection of cysteine based on a tandem reaction of thiol-ene click chemistry and aminolysis involving 3-hydroxythalidomide as a parent compound. Experimental data exhibited that the probe showed unique selectivity and sensitivity for cysteine over other amino acid and biothiols. In addition, the fluorescent intensity at 511 nm increased linearly as a function of cysteine concentration in the range of 0-6 × 10-7 M (regression factor, R2 = 0.999), with a limit of detection of 6.1 nM. The sensing mechanism was confirmed through 1H NMR titration and density functional theory calculations. Additionally, the probe was also successfully utilized for the detection of cysteine in sewage and for bioimaging in HeLa cells.

4.
Medicine (Baltimore) ; 103(34): e39461, 2024 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-39183439

RESUMEN

RATIONALE: Breast adenoid cystic carcinoma is an extremely rare tumor that is incompletely understood, accounting for less than <0.1% of all breast cancers, with an average diameter of 3 cm, and it is extremely rare to see a large, non-metastatic breast adenoid cystic carcinoma with a diameter of about 30 cm. Since this disease is extremely rare, there are few reports in the literature and limited data on clinical diagnosis and treatment. We present a case of a 71-year-old woman with a large, non-metastatic adenoid cystic carcinoma of the left breast and share our opinion on the diagnosis and treatment of this case. PATIENT CONCERNS: A 71-year-old woman with a 20-year-old left breast mass with local bleeding and rupture for 1 hour presented to our hospital for further diagnosis and treatment. A computed tomography scan showed a large soft tissue mass shadow in the left breast and malignancy was considered. Subsequently, tissue aspiration pathology was performed and the results confirmed adenoid cystic carcinoma of the breast. DIAGNOSIS: Intraoperative pathology results of radical mastectomy for left breast cancer diagnosed adenoid cystic carcinoma of the breast and immunohistochemistry results of triple-negative breast cancer. INTERVENTIONS AND OUTCOMES: Treatment of adenoid cystic carcinoma of the breast included neoadjuvant chemotherapy for breast cancer, radical mastectomy of the left breast, and postoperative chemotherapy. Initially, neoadjuvant chemotherapy for breast cancer was performed, and the TAC regimen was used to successfully reduce the size of the tumor and gain access to surgical treatment for breast cancer. The patient has recovered well after the surgery, with no wound infection or ulceration, and is now waiting for the patient's physical function to recover for postoperative chemotherapy, with no obvious discomfort. LESSONS: Adenoid cystic carcinoma tumors are usually around 3 cm; such a huge 30 cm adenoid cystic carcinoma of the breast is extremely rare, and it is extremely rare to find a breast malignancy that has not developed regional lymph node and distant metastases for more than 20 years. Clinicians must remain vigilant for early breast malignancies at a high age of incidence and conduct further research for diagnosis to avoid delays.


Asunto(s)
Neoplasias de la Mama , Carcinoma Adenoide Quístico , Humanos , Carcinoma Adenoide Quístico/cirugía , Carcinoma Adenoide Quístico/patología , Carcinoma Adenoide Quístico/diagnóstico , Carcinoma Adenoide Quístico/terapia , Femenino , Anciano , Neoplasias de la Mama/patología , Neoplasias de la Mama/diagnóstico
5.
Front Oncol ; 14: 1364608, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38978734

RESUMEN

Background: Breast cancer (BC) in adolescents and young adults (AYAs, aged 15-39 years), remains inadequately understood. The incidence of BC in AYAs has been steadily increasing, making it the second leading cause of cancer-related mortality among females aged 0-39 globally. This study aimed to elucidate the clinical characteristics and long-term outcomes of AYAs and older adults (OAs, aged > 39 years) with BC who underwent surgery. Methods: From January 2011 to June 2017, BC patients who underwent surgery were enrolled in this study and divided into AYA group and OA group. Clinical characteristics, recurrence-free survival (RFS), and overall survival (OS) were compared between these two groups, both before and after propensity score matching (PSM). Univariate and multivariate Cox proportional hazard regression analyses were performed to assess the influence of age on OS and RFS. Results: Compared to the OA group, the AYA group exhibited a younger age at menarche (p < 0.001), a lower prevalence of menopausal status (p < 0.001), a reduced occurrence of comorbid conditions (p < 0.001), fewer instances of undergoing mastectomy (p = 0.031), a higher incidence of Triple-Negative Breast Cancer (TNBC) (p = 0.046), and elevated Ki-67 levels (p = 0.036). In terms of prognostic outcomes, within the study cohort, AYAs had a higher mortality rate and poorer long-term survival compared to OAs, both before and after PSM. In the PSM cohort, AYAs experienced a significantly shorter median OS (p < 0.001) and RFS (p < 0.001). Young age (15-39 years) emerged as an independent risk factor for OS (HR 2.659, 95% CI 1.385-5.106, p = 0.003) and RFS (HR 3.235, 95% CI 2.085-5.022, p < 0.001) in BC patients following surgery. Conclusion: Significant differences were identified in the clinicopathological characteristics between AYA and OA patients with BC. In comparison to OA patients, AYA patients exhibited a less favorable long-term prognosis, with young age emerging as an independent prognostic risk factor for both OS and RFS in BC patients following surgery. Further investigations are warranted to develop age-specific therapeutic approaches for AYA BC patients.

6.
PLoS One ; 19(5): e0294923, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38758814

RESUMEN

BACKGROUND: The workload of breast cancer pathological diagnosis is very heavy. The purpose of this study is to establish a nomogram model based on pathological images to predict the benign and malignant nature of breast diseases and to validate its predictive performance. METHODS: In retrospect, a total of 2,723 H&E-stained pathological images were collected from 1,474 patients at Qingdao Central Hospital between 2019 and 2022. The dataset consisted of 509 benign tumor images (adenosis and fibroadenoma) and 2,214 malignant tumor images (infiltrating ductal carcinoma). The images were divided into a training set (1,907) and a validation set (816). Python3.7 was used to extract the values of the R channel, G channel, B channel, and one-dimensional information entropy from all images. Multivariable logistic regression was used to select variables and establish the breast tissue pathological image prediction model. RESULTS: The R channel value, B channel value, and one-dimensional information entropy of the images were identified as independent predictive factors for the classification of benign and malignant pathological images (P < 0.05). The area under the curve (AUC) of the nomogram model in the training set was 0.889 (95% CI: 0.869, 0.909), and the AUC in the validation set was 0.838 (95% CI: 0.7980.877). The calibration curve results showed that the calibration curve of this nomogram model was close to the ideal curve. The decision curve results indicated that the predictive model curve had a high value for auxiliary diagnosis. CONCLUSION: The nomogram model for the prediction of benign and malignant breast diseases based on pathological images demonstrates good predictive performance. This model can assist in the diagnosis of breast tissue pathological images.


Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/patología , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/diagnóstico , Persona de Mediana Edad , Adulto , Nomogramas , Fibroadenoma/patología , Fibroadenoma/diagnóstico por imagen , Fibroadenoma/diagnóstico , Estudios Retrospectivos , Mama/patología , Mama/diagnóstico por imagen , Anciano
7.
Sci Total Environ ; 896: 165226, 2023 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-37392888

RESUMEN

Arsenic and cadmium in rice grain are of growing concern in the global food supply chain. Paradoxically, the two elements have contrasting behaviors in soils, making it difficult to develop a strategy that can concurrently reduce their uptake and accumulation by rice plant. This study examined the combined impacts of watering (irrigation) schemes, different fertilizers and microbial populations on the bioaccumulation of arsenic and cadmium by rice as well as on rice grain yield. Compared to drain-flood and flood-drain treatments, continuously flooded condition significantly reduced the accumulation of cadmium in rice plant but the level of arsenic in rice grain remained above 0.2 mg/kg, which exceeded the China national food safety standard. Application of different fertilizers under continuously flooded condition showed that compared to inorganic fertilizer and biochar, manure addition effectively reduced the accumulation of arsenic over three to four times in rice grain and both elements were below the food safety standard (0.2 mg/kg) while significantly increasing the rice yield. Soil Eh was the critical factor in the bioavailability of cadmium, while the behavior of arsenic in rhizosphere was associated with the iron cycle. The results of the multi-parametric experiments can be used as a roadmap for low-cost and in-situ approach for producing safe rice without compromising the yield.


Asunto(s)
Arsénico , Oryza , Contaminantes del Suelo , Arsénico/análisis , Cadmio/análisis , Fertilizantes , Contaminantes del Suelo/análisis , Suelo
8.
PLoS One ; 18(6): e0287704, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37379301

RESUMEN

OBJECTIVE: Protective color restoration of faded digital pathology images based on color transfer algorithm. METHODS: Twenty fresh tissue samples of invasive breast cancer from the pathology department of Qingdao Central Hospital in 2021 were screened. After HE staining, HE stained sections were irradiated with sunlight to simulate natural fading, and every 7 days was a fading cycle, and a total of 8 cycles were experienced. At the end of each cycle, the sections were digitally scanned to retain clear images, and the color changes of the sections during the fading process were recorded. The color transfer algorithm was applied to restore the color of the faded images; Adobe Lightroom Classic software presented the histogram of the image color distribution; UNet++ cell recognition segmentation model was used to identify the color restored images; Natural Image Quality Evaluator (NIQE), Information Entropy (Entropy), and Average Gradient (AG) were applied to evaluate the quality of the restored images. RESULTS: The restored image color met the diagnostic needs of pathologists. Compared with the faded images, the NIQE value decreased (P<0.05), Entropy value increased (P<0.01), and AG value increased (P<0.01). The cell recognition rate of the restored image was significantly improved. CONCLUSION: The color transfer algorithm can effectively repair faded pathology images, restore the color contrast between nucleus and cytoplasm, improve the image quality, meet the diagnostic needs and improve the cell recognition rate of the deep learning model.


Asunto(s)
Algoritmos , Neoplasias de la Mama , Humanos , Femenino , Programas Informáticos , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Procesamiento de Imagen Asistido por Computador/métodos , Color
9.
Environ Int ; 174: 107911, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37030286

RESUMEN

Gut microbiota provides protection against arsenic (As) induced toxicity, and As metabolism is considered an important part of risk assessment associated with soil As exposures. However, little is known about microbial iron(III) reduction and its role in metabolism of soil-bound As in the human gut. Here, we determined the dissolution and transformation of As and Fe from incidental ingestion of contaminated soils as a function of particle size (<250 µm, 100-250 µm, 50-100 µm and < 50 µm). Colon incubation with human gut microbiota yielded a high degree of As reduction and methylation of up to 53.4 and 0.074 µg/(log CFU/mL)/hr, respectively; methylation percentage increased with increasing soil organic matter and decreasing soil pore size. We also found significant microbial Fe(III) reduction and high levels of Fe(II) (48 %-100 % of total soluble Fe) may promote the capacity of As methylation. Although no statistical change in Fe phases was observed with low Fe dissolution and high molar Fe/As ratios, higher As bioaccessibility of colon phase (avg. 29.4 %) was mainly contributed from reductive dissolution of As(V)-bearing Fe(III) (oxy)hydroxides. Our results suggest that As mobility and biotransformation by human gut microbiota (carrying arrA and arsC genes) are strongly controlled by microbial Fe(III) reduction coupled with soil particle size. This will expand our knowledge on oral bioavailability of soil As and health risks from exposure to contaminated soils.


Asunto(s)
Arsénico , Contaminantes del Suelo , Humanos , Arsénico/análisis , Compuestos Férricos , Suelo , Tamaño de la Partícula , Tracto Gastrointestinal , Hierro/metabolismo , Contaminantes del Suelo/análisis
10.
J Hazard Mater ; 416: 125899, 2021 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-34492837

RESUMEN

Incidental oral ingestion is considered to be an important exposure route for humans to soil contaminants, such as fluoride (F). For 25 soil samples containing 4000 mg F/kg from aluminium smelting site in southwestern China, this study investigated F bioaccessibility in the human gastrointestinal tract in vitro. Fluoride bioaccessibility (2.4-48.8%) in the gastric phase was primarily caused by the dissolution of F-Ca and F-Al compounds (assigned to residual phase), identified by X-ray photoelectron spectroscopy and sequential extraction. Following modification to the small intestinal phase, the variation in F bioaccessibility (2.5-38.8%) should be the result of concurrent processes, including the formation of F complexes and competitive adsorption, and inversely the precipitation of fluorite and surface adsorption of formed F-Al complexes. The colon incubation with human gut microbiota yielded a 1.3-fold increase in F bioaccessibility (3.9-45.7%), probably due to the dissolution of F bound to Fe (hydr)oxides. Bioaccessibility adjustment can reduce hazard quotient of fluoride, and non-carcinogenic risk for children should be noted that soil F intake contributed 21.7% on average, up to 76.6% of oral reference dose. This will result in better understanding of human health risk assessment associated with F exposures.


Asunto(s)
Aluminio , Contaminantes del Suelo , Aluminio/metabolismo , Aluminio/toxicidad , Disponibilidad Biológica , Niño , Fluoruros/toxicidad , Tracto Gastrointestinal/metabolismo , Humanos , Medición de Riesgo , Suelo , Contaminantes del Suelo/metabolismo
11.
Environ Pollut ; 279: 116943, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33770653

RESUMEN

To identify the role of gut microbiota in human health risk assessment, the bioaccessibility of heavy metals in 14 soil samples were determined in simulated gastrointestinal fluids. Compared to the small intestinal phase, the bioaccessibility values of the colon phase varied, either increased by 3.5-fold for As, by 2.2-fold for Cr, and by 1.6-fold for Ni, or reduced by 4.4-fold for Cu, respectively. The colon incubation with adult gut microbiota yielded higher bioaccessibility value of As (1.3 times) and Fe (3.4 times) than that of the child in most soil samples. Colon bioaccessibility was about 60% greater of Cd for the adult and 30% higher of Cr for the child. Congruent data on the bioaccessibility of Cu and Ni was observed. In addition, correlation analysis indicated that in vitro bioaccessibility was primarily related to total concentrations of heavy metals in soils, followed by soil pH and active Fe/Mn oxide. Significantly, risk assessment calculated based on colon bioaccessibility indicated that the target hazard quotient (THQ > 1) of As was presented in 3 soil samples for the adult (1.05-3.35) and in 9 soil samples for the child (1.06-26.93). The hazard index (HI) of the child was 4.00 on average, greater than that of the adult (0.62), primarily due to the contribution of As and Cd. It suggested non-carcinogenic risks are likely to occur in children through typical hand-to-mouth behavior. The adjustment of colon bioaccessibility will result in more accurate risk assessment of human exposure to heavy metals from oral ingestion of contaminated soils.


Asunto(s)
Microbioma Gastrointestinal , Metales Pesados , Contaminantes del Suelo , Adulto , Niño , China , Ingestión de Alimentos , Monitoreo del Ambiente , Humanos , Metales Pesados/análisis , Metales Pesados/toxicidad , Medición de Riesgo , Suelo , Contaminantes del Suelo/análisis
12.
Huan Jing Ke Xue ; 42(3): 1158-1165, 2021 Mar 08.
Artículo en Chino | MEDLINE | ID: mdl-33742912

RESUMEN

The remediation potential of large biomass energy grasses in cadmium-contaminated soil remains ambiguous. A field experiment was carried out in a cadmium-contaminated farmland using two energy grasses and two control plants. The two energy grasses were hybrid pennisetum (Pennisetum americanum×P. purpureum, PAP) and purple elephant grass (P. purpureum 'Purple', PPP), and the two control plants were Iris lactea var. chinensis (ILC) and a cadmium hyperaccumulator, Noccaea caerulescens (NC). The results showed that the aboveground biomass of PAP was the largest among the four plants, and 126 and 36 times that of NC and ILC, respectively, but no significant difference with that of PPP. The concentrations of cadmium and zinc in the shoots and roots of NC were significantly higher than in the other plants. Zinc concentrations in the shoots and roots of ILC were lower than in the other plants, while cadmium concentrations were significantly higher than in PAP and PPP (P<0.05). The amounts of cadmium and zinc accumulated in the shoots of PPP were the highest among the four plants, while cadmium concentrations in the shoots and roots of PPP were significantly lower than in ILC and NC (P<0.05). Cadmium amounts accumulated in PPP shoots were 7.0 and 4.1 times that of ILC and NC, respectively. Zinc amounts accumulated in PPP shoots were 41 and 11 times that of ILC and NC, respectively (P<0.05). Cadmium accumulation in the shoots of PAP was 19.4% lower than in PPP, and zinc accumulation had no significant difference with that of PPP. NC, having a bioconcentration factor of shoot (BCFS) and a translocation factor (TF) for cadmium and zinc both larger than 1, is usable for phytoextraction of soils contaminated by cadmium and zinc. ILC, having a bioconcentration factor of root (BCFR) larger than 1 and a TF lower than 1 for cadmium, is usable for the phytostabilization of soils contaminated by cadmium. PPP, having a BCFR larger than 1 and a TF lower than 1 for zinc, can be used in the phytostabilization of soils contaminated by zinc. Under field conditions, PPP and PAP showed great potential for the extraction and removal of cadmium and zinc from soil due to their large biomass and ability to produce economic benefits, have good application prospects.


Asunto(s)
Cadmio , Contaminantes del Suelo , Biodegradación Ambiental , Cadmio/análisis , Raíces de Plantas/química , Suelo , Contaminantes del Suelo/análisis , Zinc/análisis
13.
J Hazard Mater ; 412: 125131, 2021 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-33516100

RESUMEN

Arsenic (As) is a well-known human carcinogen, and rice consumption is the main way Chinese people are exposed to As. In this study, 14 kinds of paddy soils were collected from the main rice-producing areas in China. The results showed that rice roots and leaves accumulated more As than stems and grains in the following sequence: Asroot> Asleaf> Asstem> Asgrain. The accumulation of As by rice grains mainly depends on the total As and bioavailable As (0.43 mol/L HNO3 extractable As), which explained 32.2% and 22.2% of the variation in the grain As, respectively. In addition, soil pH, organic matter (OM) and clay contents were the major factors affecting grain As, explaining 13.1%, 7.9% and 5.3% of the variation, respectively. An effective prediction model was established via multiple linear regression as Asgrain= 0.024 BAs - 0.225 pH+ 0.013 OM+ 0.648 EC - 0.320 TN - 0.088 TP - 0.002 AS+ 2.157 (R2 =0.68, P < 0.01). Through the verification of the samples from both pot experiments and paddy fields, the model successfully provided accurate predictions for rice grain As.


Asunto(s)
Arsénico , Oryza , Contaminantes del Suelo , Arsénico/análisis , China , Humanos , Suelo , Contaminantes del Suelo/análisis
14.
J Hazard Mater ; 383: 121160, 2020 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-31518812

RESUMEN

The application of current soil quality standards based on total arsenic (As) fails to assess the ecological risks of soil arsenic or to ensure the safety of crops and foods. In this study, bioavailable arsenic instead of total arsenic was applied to improve predictive models for arsenic transfer from soil to wheat (Triticum turgidum L.). The stepwise multiple-linear regression analysis showed that bioavailable arsenic and amorphous iron oxides (FeOX) were the two most important factors contributing to arsenic accumulation in wheat grain, with the explained percentage of variation being up to 82%. Compared with the bioavailable arsenic extracted by NH4H2PO4, bioavailable arsenic extracted by HNO3 from soils generated better predictions of the amount of arsenic in grain. The best reliable model was log[Asgrain] = 0.917 log[HNO3-As] - 0.452 log[FeOX] - 1.507 (R2 = 0.82, P <  0.001). Consistently, bioavailable arsenic and FeOX were also the key factors to predict arsenic accumulation in wheat straw, leaves and spikes. Our prediction models was successfully verified for three independent soils. Our results highlight the role of soil bioavailable heavy metals in predicting their transfer in soil-plant systems and can be used to improve existing Chinese soil quality standards.


Asunto(s)
Arsénico/farmacocinética , Compuestos Férricos/farmacocinética , Contaminantes del Suelo/farmacocinética , Triticum/metabolismo , Disponibilidad Biológica
15.
Environ Sci Technol ; 53(15): 8533-8542, 2019 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-31269402

RESUMEN

Global paddy soil is the primary source of methane, a potent greenhouse gas. It is therefore highly important to understand the carbon cycling in paddy soil. Microbial reduction of iron, which is widely found in paddy soil, is likely coupled with the oxidation of dissolved organic matter (DOM) and suppresses methanogenesis. However, little is known about the biotransformation of small molecular DOM accumulated under flooded conditions and the effect of iron reduction on the biotransformation pathway. Here, we carried out anaerobic incubation experiments using field-collected samples amended with ferrihydrite and different short-chain fatty acids. Our results showed that less than 20% of short-chain fatty acids were mineralized and released to the atmosphere. Using Fourier transform ion cyclotron resonance mass spectrometry, we further found that a large number of recalcitrant molecules were produced during microbial consumption of these short-chain fatty acids. Moreover, the biotransformation efficiency of short-chain fatty acids decreased with the increasing length of carbon chains. Ferrihydrite addition promoted microbial assimilation of short-chain fatty acids as well as enhanced the activation and biotransformation of indigenous stable carbon in the soil replenished with formate. This study demonstrates the significance of ferrihydrite in the biotransformation of labile DOM and promotes a more comprehensive understanding of the coupling of iron reduction and carbon cycling in paddy soils.


Asunto(s)
Oryza , Suelo , Carbono , Ciclo del Carbono , Hierro , Metano , Microbiología del Suelo
16.
Environ Sci Technol ; 52(3): 963-971, 2018 02 06.
Artículo en Inglés | MEDLINE | ID: mdl-29301078

RESUMEN

Organic matter (OM), and dissolved organic matter (DOM), have a major influence upon biogeochemical processes; most significantly, the carbon cycle. To date, very few studies have examined the spatial heterogeneity of DOM in paddy soils. Thus, very little is known about the DOM molecular profiles and the key environmental factors that underpin DOM molecular chemodiversity in paddy soils. Here, Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry was applied to unambiguously resolve 11 361 molecular formulas in 16 paddy soils; thereby elucidating the molecular characteristics of paddy soil DOM. Soil pH, iron complexing index (Fep/FeR) and C/N ratio were established to be key factors controlling DOM profiles. Polycyclic aromatics (derived from combustion) and polyphenols (derived from plants) increased with increasing pH, while polyphenols molecules, pyrogenic aromatics, and carboxylic compounds decreased with increasing iron complexing index. Patterns in molecular profiles indicated DOM in paddy soils to become more recalcitrant at higher soil C/N ratio and higher pH. Furthermore, plant-derived polyphenols and pyrogenic DOM were retained favorably by iron and the chemodiversity of DOM in paddy soil increased with increasing soil C/N ratios. This study provides critical information about DOM characteristics at a molecular level and will inform better global management of soil carbon in paddy soil ecosystems.


Asunto(s)
Contaminantes del Suelo , Suelo , Carbono , Ciclo del Carbono , Ecosistema
17.
Sci Rep ; 7(1): 7741, 2017 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-28798375

RESUMEN

The toxic metalloid arsenic has been environmentally ubiquitous since life first arose nearly four billion years ago and presents a challenge for the survival of all living organisms. Its bioavailability has varied dramatically over the history of life on Earth. As life spread, biogeochemical and climate changes cyclically increased and decreased bioavailable arsenic. To elucidate the history of arsenic adaptation across the tree of life, we reconstructed the phylogeny of the arsM gene that encodes the As(III) S-adenosylmethionine (SAM) methyltransferase. Our results suggest that life successfully moved into arsenic-rich environments in the late Archean Eon and Proterozoic Eon, respectively, by the spread of arsM genes. The arsM genes of bacterial origin have been transferred to other kingdoms of life on at least six occasions, and the resulting domesticated arsM genes promoted adaptation to environmental arsenic. These results allow us to peer into the history of arsenic adaptation of life on our planet and imply that dissemination of genes encoding diverse adaptive functions to toxic chemicals permit adaptation to changes in concentrations of environmental toxins over evolutionary history.


Asunto(s)
Adaptación Biológica/efectos de los fármacos , Adaptación Biológica/genética , Arsénico/toxicidad , Transferencia de Gen Horizontal , Metiltransferasas/genética , Animales , Archaea/efectos de los fármacos , Archaea/genética , Arsénico/metabolismo , Bacterias/efectos de los fármacos , Bacterias/genética , Eucariontes/efectos de los fármacos , Eucariontes/genética , Hongos/efectos de los fármacos , Hongos/genética , Metilación , Metiltransferasas/metabolismo , Modelos Biológicos , Filogenia
18.
Environ Sci Pollut Res Int ; 24(7): 6532-6542, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28074369

RESUMEN

Greenhouse experiments were conducted to investigate the influence of rice straw biochar (RSB) on soil cadmium (Cd) availability and accumulation in lettuce. The RSB was applied either in bands or broadcast in the test site of four greenhouses with soil Cd concentrations ranging from 1.70-3.14 µg g-1. Biochar doses applied in bands were half of those broadcast. The Cd levels in the shoots of lettuce were observed to be reduced by up to 57% with increasing RSB application rate (0, 6, 12, 18 t ha-1). Following RSB application, shoot Cd concentrations of lettuce were reduced to below the Chinese threshold value set for food, and hazard quotients for Cd associated with vegetable consumption were reduced from 0.70-1.11 to 0.42-0.65. A decrease in soil bulk density (11%) and increases in water holding capacity (16%), available phosphorus (30%), available potassium (197%), and lettuce yield (15%) were observed after RSB application. Multiple linear regression analysis suggested that the soil extractable Cd level (but not biomass dilution) and soil bulk density, as influenced by RSB addition, were the dominant contributors to the shoot Cd levels in lettuce and lettuce yield, respectively. These results highlight the potential for RSB to mitigate the phytoaccumulation of Cd and thereby to reduce human exposure from vegetable consumption. Application of biochar in band, rather than broadcasting over the entire area, represents an opportunity to halve the biochar cost while retaining a good remediation effect.


Asunto(s)
Cadmio/análisis , Carbón Orgánico/química , Lactuca/crecimiento & desarrollo , Contaminantes del Suelo/análisis , Suelo/química , Agricultura , Biomasa , Cadmio/metabolismo , Lactuca/metabolismo , Oryza/química , Contaminantes del Suelo/metabolismo
19.
Biosens Bioelectron ; 80: 288-293, 2016 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-26852196

RESUMEN

A diketopyrrolopyrrole-based probe DPP-PyR was able to recognize Fe(3+) and Au(3+) with fluorescent turn-on response via different emission modes with relatively low detection limit. Moreover, DPP-PyR exhibited preferential second mode of selectivity for Au(3+) as it ratiometrically displaced Fe(3+) from the [DPP-PyR+Fe(3+)] complex. Furthermore, the imaging experiments indicated that this probe was cell-permeable and could be used to detect Fe(3+) and Au(3+) ions within living cell. To the best of our knowledge, it was the first probe for detection Fe(3+) and Au (3+) at the same time ever reported.


Asunto(s)
Colorantes Fluorescentes/química , Oro/análisis , Hierro/análisis , Imagen Óptica/métodos , Pirroles/química , Técnicas Biosensibles/métodos , Cationes/análisis , Línea Celular Tumoral , Supervivencia Celular , Fluorescencia , Humanos
20.
Environ Sci Pollut Res Int ; 23(4): 3781-8, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26498817

RESUMEN

A field experiment was established to support the hypothesis that application of different silicon (Si) fertilizers can simultaneously reduce cadmium (Cd) and arsenic (As) concentration in rice grain. The "semi-finished product of Si-potash fertilizer" treatment at the high application of 9000 kg/ha (NP+S-KSi9000) significantly reduced the As concentration in rice grain by up to 20.1%, compared with the control. Si fertilization reduces the Cd concentration in rice considerably more than the As concentration. All Si fertilizers apart from sodium metasilicate (Na2SiO3) exhibited a high ability to reduce Cd concentration in rice grain. The Si-calcium (CaSi) fertilizer is the most effective in the mitigation of Cd concentration in rice grain. The CaSi fertilizer applied at 9000 kg/ha (NPK+CaSi9000) and 900 kg/ha (NPK+CaSi900) reduced the Cd concentration in rice grain about 71.5 and 48.0%, respectively, while the Si-potash fertilizer at 900 kg/ha (NP+KSi900), the semi-finished product of Si-potash fertilizer at both 900 kg/ha (NP+S-KSi900) and 9000 kg/ha (NP+S-KSi9000), and the rice straw (NPK+RS) treatments reduced the Cd concentration in rice grain about 42, 26.5, 40.7, and 23.1%, respectively. The results of this investigation demonstrated the potential effects of Si fertilizers in reducing Cd and As concentrations in rice grain.


Asunto(s)
Arsénico/análisis , Cadmio/análisis , Grano Comestible/crecimiento & desarrollo , Fertilizantes/análisis , Oryza/crecimiento & desarrollo , Silicio/química , Contaminantes del Suelo/análisis , Arsénico/metabolismo , Cadmio/metabolismo , Grano Comestible/química , Oryza/química , Contaminantes del Suelo/metabolismo
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