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1.
Glob Chang Biol ; 30(5): e17311, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38742695

RESUMEN

The soil microbial carbon pump (MCP) is increasingly acknowledged as being directly linked to soil organic carbon (SOC) accumulation and stability. Given the close coupling of carbon (C) and nitrogen (N) cycles and the constraints imposed by their stoichiometry on microbial growth, N addition might affect microbial growth strategies with potential consequences for necromass formation and carbon stability. However, this topic remains largely unexplored. Based on two multi-level N fertilizer experiments over 10 years in two soils with contrasting soil fertility located in the North (Cambisol, carbon-poor) and Southwest (Luvisol, carbon-rich), we hypothesized that different resource demands of microorganism elicit a trade-off in microbial growth potential (Y-strategy) and resource-acquisition (A-strategy) in response to N addition, and consequently on necromass formation and soil carbon stability. We combined measurements of necromass metrics (MCP efficacy) and soil carbon stability (chemical composition and mineral associated organic carbon) with potential changes in microbial life history strategies (assessed via soil metagenomes and enzymatic activity analyses). The contribution of microbial necromass to SOC decreased with N addition in the Cambisol, but increased in the Luvisol. Soil microbial life strategies displayed two distinct responses in two soils after N amendment: shift toward A-strategy (Cambisol) or Y-strategy (Luvisol). These divergent responses are owing to the stoichiometric imbalance between microbial demands and resource availability for C and N, which presented very distinct patterns in the two soils. The partial correlation analysis further confirmed that high N addition aggravated stoichiometric carbon demand, shifting the microbial community strategy toward resource-acquisition which reduced carbon stability in Cambisol. In contrast, the microbial Y-strategy had the positive direct effect on MCP efficacy in Luvisol, which greatly enhanced carbon stability. Such findings provide mechanistic insights into the stoichiometric regulation of MCP efficacy, and how this is mediated by site-specific trade-offs in microbial life strategies, which contribute to improving our comprehension of soil microbial C sequestration and potential optimization of agricultural N management.


Asunto(s)
Carbono , Fertilizantes , Nitrógeno , Microbiología del Suelo , Suelo , Suelo/química , Carbono/metabolismo , Carbono/análisis , Nitrógeno/metabolismo , Nitrógeno/análisis , Fertilizantes/análisis , Ciclo del Carbono , Microbiota
2.
J Environ Manage ; 358: 120911, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38631164

RESUMEN

Dissolved organic matter (DOM) is important in determining the drinking water treatment and the supplied water quality. However, a comprehensive DOM study for the whole water supply system is lacking and the potential effects of secondary water supply are largely unknown. This was studied using dissolved organic carbon (DOC), absorption spectroscopy, and fluorescence excitation-emission matrices-parallel factor analysis (EEM-PARAFAC). Four fluorescent components were identified, including humic-like C1-C2, tryptophan-like C3, and tyrosine-like C4. In the drinking water treatment plants, the advanced treatment using ozone and biological activated carbon (O3-BAC) was more effective in removing DOC than the conventional process, with the removals of C1 and C3 improved by 17.7%-25.1% and 19.2%-27.0%. The absorption coefficient and C1-C4 correlated significantly with DOC in water treatments, suggesting that absorption and fluorescence could effectively track the changes in bulk DOM. DOM generally remained stable in each drinking water distribution system, suggesting the importance of the treated water quality in determining that of the corresponding network. The optical indices changed notably between distribution networks of different treatment plants, which enabled the identification of changing water sources. A comparison of DOM in the direct and secondary water supplies suggested limited impacts of secondary water supply, although the changes in organic carbon and absorption indices were detected in some locations. These results have implications for better understanding the changes of DOM in the whole water supply system to help ensure the supplied water quality.


Asunto(s)
Abastecimiento de Agua , Calidad del Agua , Purificación del Agua/métodos , Sustancias Húmicas/análisis , Agua Potable/química , Agua Potable/análisis , Carbono/análisis
3.
Fungal Genet Biol ; 143: 103431, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32610064

RESUMEN

Cordyceps genus, such as C. militaris and C. kyushuensis, is a source of a rare traditional Chinese medicine that has been used for the treatment of numerous chronic and malignant diseases. Cordycepin, 3'-deoxyadenosine, is a major active compound found in most Cordyceps. Cordycepin exhibits a variety of biological activities, including anti-tumor, immunomodulation, antioxidant, and anti-aging, among others, which could be applied in health products, medicine, cosmeceutical etc. fields. This review focuses on the synthesis methods for cordycepin. The current methods for cordycepin synthesis involve chemical synthesis, microbial fermentation, in vitro synthesis and biosynthesis; however, some defects are unavoidable and the production is still far from the demand of cordycepin. For the future study of cordycepin synthesis, based on the illumination of cordycepin biosynthesis pathway, genetical engineering of the Cordyceps strain or introducing microbes by virtue of synthetic biology will be the great potential strategies for cordycepin synthesis. This review will aid the future synthesis of the valuable cordycepin.


Asunto(s)
Antioxidantes/química , Vías Biosintéticas/genética , Cordyceps/química , Desoxiadenosinas/biosíntesis , Antioxidantes/uso terapéutico , Desoxiadenosinas/genética , Desoxiadenosinas/uso terapéutico , Fermentación , Humanos , Medicina Tradicional China
4.
Environ Sci Technol ; 53(5): 2539-2548, 2019 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-30754969

RESUMEN

Neonicotinoid insecticides have been widely consumed worldwide, particularly in China. There is a growing interest in the environmental research community about the occurrence, fates, sources, and risks of neonicotinoids. Nine neonicotinoids in river/lake water were measured at 12 sites along the Yangtze River Basin during the dry and wet seasons in 2016, and nonpoint sources were also identified based on a modified mass balance method. A significantly higher concentration of neonicotinoids was found during the dry season probably due to the dilution effect and insecticide consumption. The high pollution levels are due to posing high ecological risks compared with the recommended thresholds. In 2016, 1190 (95% confidence interval (CI) = 822-1690) tons of neonicotinoids were transferred into the adjacent sea. Nonpoint source pollution (1700 (CI = 1200-2370) tons) was the major contributor (91.3%) to the total input of neonicotinoids into the system. Composition profiles identifying specific neonicotinoid sources indicated some changes in usage patterns from old to new types of neonicotinoids. This spatial and seasonal field study and source identification is expected to fill the data gap regarding the limited information on neonicotinoid use patterns and to inform further effective policy-making and intervention programs in China that should be urgently promoted in the near future.


Asunto(s)
Contaminación Difusa , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Neonicotinoides , Ríos
5.
Microb Cell Fact ; 15: 14, 2016 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-26785630

RESUMEN

BACKGROUND: Protoilludene is a valuable sesquiterpene and serves as a precursor for several medicinal compounds and antimicrobial chemicals. It can be synthesized by heterologous expression of protoilludene synthase in Escherichia coli with overexpression of mevalonate (MVA) or methylerythritol-phosphate (MEP) pathway, and farnesyl diphosphate (FPP) synthase. Here, we present E. coli as a cell factory for protoilludene production. RESULTS: Protoilludene was successfully produced in E. coli by overexpression of a hybrid exogenous MVA pathway, endogenous FPP synthase (IspA), and protoilludene synthase (OMP7) of Omphalotus olearius. For improving protoilludene production, the MVA pathway was engineered to increase synthesis of building blocks isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) by sequential order permutation of the lower MVA portion (MvL), the alteration of promoters and copy numbers for the upper MVA portion (MvU), and the coordination of both portions, resulting in an efficient entire MVA pathway. To reduce the accumulation of mevalonate observed in the culture broth due to lower efficiency of the MvL than the MvU, the MvL was further engineered by homolog substitution with the corresponding genes from Staphylococcus aureus. Finally, the highest protoilludene production of 1199 mg/L was obtained from recombinant E. coli harboring the optimized hybrid MVA pathway in a test tube culture. CONCLUSIONS: This is the first report of microbial synthesis of protoilludene by using an engineered E. coli strain. The protoilludene production was increased by approx. Thousandfold from an initial titer of 1.14 mg/L. The strategies of both the sequential order permutation and homolog substitution could provide a new perspective of engineering MVA pathway, and be applied to optimization of other metabolic pathways.


Asunto(s)
Escherichia coli/metabolismo , Ácido Mevalónico/metabolismo , Geraniltranstransferasa/metabolismo , Hemiterpenos/metabolismo , Compuestos Organofosforados/metabolismo
6.
Sensors (Basel) ; 14(1): 1771-86, 2014 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-24448170

RESUMEN

This study aimed at monitoring the changes of fluorescent components in wastewater samples from 22 Korean biological wastewater treatment plants and exploring their prediction capabilities for total organic carbon (TOC), dissolved organic carbon (DOC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), and the biodegradability of the wastewater using an optical sensing technique based on fluorescence excitation emission matrices and parallel factor analysis (EEM-PARAFAC). Three fluorescent components were identified from the samples by using EEM-PARAFAC, including protein-like (C1), fulvic-like (C2) and humic-like (C3) components. C1 showed the highest removal efficiencies for all the treatment types investigated here (69% ± 26%-81% ± 8%), followed by C2 (37% ± 27%-65% ± 35%), while humic-like component (i.e., C3) tended to be accumulated during the biological treatment processes. The percentage of C1 in total fluorescence (%C1) decreased from 54% ± 8% in the influents to 28% ± 8% in the effluents, while those of C2 and C3 (%C2 and %C3) increased from 43% ± 6% to 62% ± 9% and from 3% ± 7% to 10% ± 8%, respectively. The concentrations of TOC, DOC, BOD, and COD were the most correlated with the fluorescence intensity (Fmax) of C1 (r = 0.790-0.817), as compared with the other two fluorescent components. The prediction capability of C1 for TOC, BOD, and COD were improved by using multiple regression based on Fmax of C1 and suspended solids (SS) (r = 0.856-0.865), both of which can be easily monitored in situ. The biodegradability of organic matter in BOD/COD were significantly correlated with each PARAFAC component and their combinations (r = -0.598-0.613, p < 0.001), with the highest correlation coefficient shown for %C1. The estimation capability was further enhanced by using multiple regressions based on %C1, %C2 and C3/C2 (r = -0.691).


Asunto(s)
Monitoreo del Ambiente/métodos , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisis , Biodegradación Ambiental , Análisis de la Demanda Biológica de Oxígeno , Análisis Factorial
7.
Environ Pollut ; 341: 122982, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-37984478

RESUMEN

Dissolved organic matter (DOM) is very important in determining the speciation, behaviors, and risk of metal pollutants in aquatic ecosystems. Photochemical and microbial degradation are key processes in the cycling of DOM, yet their effects on the DOM-Pb(II) interaction remain largely unknown. This was studied by examining the complexation of river DOM with Pb(II) after degradation, using fluorescence quenching titration and excitation-emission matrices-parallel factor analysis (EEMs-PARAFAC). Three humic-like and two protein-like components were identified, with strong removals of humic-like components and decreasing average molecular weight and humification degree of DOM by photo- and photo-microbial degradation. The changes in humic-like abundance and structure resulted in notable weakening of their interaction with Pb(II). The tryptophan-like C2 was also mainly removed by photo-degradation, while the tyrosine-like C3 could be either removed or accumulated. The Pb(II)-binding of protein-like components was generally weaker but was enhanced in some degradation groups, which might be related to the lowering competition from humic-like components. The binding parameters correlated significantly with the DOM indices, which were dominated by photo-degradation for humic-like components but by seasonal variations for the tyrosine-like component. These results have implications for understanding the key mechanisms underlying the variability of the DOM-metal interaction in aquatic environments.


Asunto(s)
Materia Orgánica Disuelta , Ecosistema , Plomo , Sustancias Húmicas/análisis , Fluorescencia , Tirosina , Espectrometría de Fluorescencia/métodos , Análisis Factorial
8.
Br J Radiol ; 97(1158): 1169-1179, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38688660

RESUMEN

OBJECTIVES: This study aimed to develop a model to predict World Health Organization/International Society of Urological Pathology (WHO/ISUP) low-grade or high-grade clear cell renal cell carcinoma (ccRCC) using 3D multiphase enhanced CT radiomics features (RFs). METHODS: CT data of 138 low-grade and 60 high-grade ccRCC cases were included. RFs were extracted from four CT phases: non-contrast phase (NCP), corticomedullary phase, nephrographic phase, and excretory phase (EP). Models were developed using various combinations of RFs and subjected to cross-validation. RESULTS: There were 107 RFs extracted from each phase of the CT images. The NCP-EP model had the best overall predictive value (AUC = 0.78), but did not significantly differ from that of the NCP model (AUC = 0.76). By considering the predictive ability of the model, the level of radiation exposure, and model simplicity, the overall best model was the Conventional image and clinical features (CICFs)-NCP model (AUC = 0.77; sensitivity 0.75, specificity 0.69, positive predictive value 0.85, negative predictive value 0.54, accuracy 0.73). The second-best model was the NCP model (AUC = 0.76). CONCLUSIONS: Combining clinical features with unenhanced CT images of the kidneys seems to be optimal for prediction of WHO/ISUP grade of ccRCC. This noninvasive method may assist in guiding more accurate treatment decisions for ccRCC. ADVANCES IN KNOWLEDGE: This study innovatively employed stability selection for RFs, enhancing model reliability. The CICFs-NCP model's simplicity and efficacy mark a significant advancement, offering a practical tool for clinical decision-making in ccRCC management.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Clasificación del Tumor , Tomografía Computarizada por Rayos X , Humanos , Carcinoma de Células Renales/diagnóstico por imagen , Carcinoma de Células Renales/patología , Neoplasias Renales/diagnóstico por imagen , Neoplasias Renales/patología , Tomografía Computarizada por Rayos X/métodos , Masculino , Persona de Mediana Edad , Femenino , Anciano , Organización Mundial de la Salud , Estudios Retrospectivos , Valor Predictivo de las Pruebas , Adulto , Imagenología Tridimensional/métodos , Sensibilidad y Especificidad , Anciano de 80 o más Años , Radiómica
9.
J Diabetes Metab Disord ; 22(2): 1029-1038, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37975092

RESUMEN

Purpose: Correcting intestinal microecological imbalance has become one of the core strategies to treat chronic diseases. Some traditional microecology-based therapies targeting intestine, such as prebiotic therapy, probiotic therapy and fecal microbiota transplantation therapy, have been used in the prevention and treatment of clinical chronic diseases, which still facing low safety and poor controllability problems. The development of synthetic biology technology has promoted the development of intestinal microecology-based therapeutics for chronic diseases, which exhibiting higher robustness and controllability, and become an important part of the next generation of microecological therapy. The purpose of this review is to summarize the application of synthetic biology in intestinal microecology-based therapeutics for chronic diseases. Methods: The available literatures were searched to find out experimental studies and relevant review articles on the application of synthetic biology in intestinal microecology-based therapeutics for chronic diseases from year 1990 to 2023. Results: Evidence proposed that synthetic biology has been applied in the intestinal microecology-based therapeutics for chronic diseases, covering metabolic diseases (e.g. diabetes, obesity, nonalcoholic fatty liver disease and phenylketonuria), digestive diseases (e.g. inflammatory bowel disease and colorectal cancer), and neurodegenerative diseases (e.g. Alzheimer's disease and Parkinson's disease). Conclusion: This review summarizes the application of synthetic biology in intestinal microecology-based therapeutics for major chronic diseases and discusses the opportunities and challenges in the above process, providing clinical possibilities of synthetic biology technology applied in microecological therapies.

10.
Water Res ; 228(Pt A): 119362, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36427460

RESUMEN

Biodegradable dissolved organic carbon (BDOC) constitutes the most labile fraction of dissolved organic matter (DOM), which also functions as a source of CO2 emissions from inland waters. However, no systematic review is available on DOM indicators of BDOC and CO2 production potential. Optical and molecular indices can be used to track small changes in DOM composition during biodegradation. In this review, we identified four different methods for measuring BDOC together with their strengths and limitations. In addition, we discuss the potential of using documented optical indices based on absorption and fluorescence spectroscopy and molecular indices based on Fourier transform ion cyclotron mass spectrometry as proxies for estimating BDOC and biodegradation-induced CO2 production based on previously reported relationships in the literature. Many absorbance- and fluorescence-based indices showed inconsistent relationships with BDOC depending on watershed characteristics, hydrology, and anthropogenic impacts. Nevertheless, several indices, including specific UV absorbance at 254 nm (SUVA254), humification index (HIX), and terrestrial humic-like fluorescent DOM (FDOM) components, tended to have negative relationships with BDOC in tropical and temperate watersheds under baseflow or drought periods. Protein-like FDOM exhibited the strongest correlation with BDOC in different systems, except during storms and flood events. Despite the limited number of studies, DOM molecular indices exhibited consistent relationships with BDOC, suggesting that the relative abundance of aliphatic formulas and the molecular lability index could act as reliable proxies. The DOM optical indices explain up to 96% and 78% variability in BDOC and CO2, respectively; nonetheless, there were limited studies on molecular indices, which explain up to 74% variability in BDOC. Based on literature survey, we recommend several sensitive indices such as SUVA254, HIX, and terrestrial humic- and protein-like FDOM, which could be useful indicators of BDOC and dissolved CO2 in inland water. Future research should incorporate a wider range of geographic regions with various land use, hydrology, and anthropogenic disturbances to develop system- or condition-specific DOM optical or molecular proxies for better prediction of BDOC and CO2 emissions.


Asunto(s)
Dióxido de Carbono , Materia Orgánica Disuelta , Efectos Antropogénicos , Biodegradación Ambiental , Colorantes
11.
Chin J Integr Med ; 29(1): 19-27, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36369612

RESUMEN

OBJECTIVE: To investigate the protective effects and its possible mechanism of Wuzi Yanzong Pill (WYP) on Parkinson's disease (PD) model mice. METHODS: Thirty-six C57BL/6 male mice were randomly assigned to 3 groups including normal, PD, and PD+WYP groups, 12 mice in each group. One week of intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was used to establish the classical PD model in mice. Meanwhile, mice in the PD+WYP group were administrated with 16 g/kg WYP, twice daily by gavage. After 14 days of administration, gait test, open field test and pole test were measured to evaluate the movement function. Tyrosine hydroxylase (TH) neurons in substantia nigra of midbrain and binding immunoglobulin heavy chain protein (GRP78) in striatum and cortex were observed by immunohistochemistry. The levels of TH, GRP78, p-PERK, p-eIF2α, ATF4, p-IRE1α, XBP1, ATF6, CHOP, ASK1, p-JNK, Caspase-12, -9 and -3 in brain were detected by Western blot. RESULTS: Compared with the PD group, WYP treatment ameliorated gait balance ability in PD mice (P<0.05). Similarly, WYP increased the total distance and average speed (P<0.05 or P<0.01), reduced rest time and pole time (P<0.05). Moreover, WYP significantly increased TH positive cells (P<0.01). Immunofluorescence showed WYP attenuated the levels of GRP78 in striatum and cortex. Meanwhile, WYP treatment significantly decreased the protein expressions of GRP78, p-PERK, p-eIF2α, ATF4, p-IRE1 α, XBP1, CHOP, Caspase-12 and Caspase-9 (P<0.05 or P<0.01). CONCLUSIONS: WYP ameliorated motor symptoms and pathological lesion of PD mice, which may be related to the regulation of unfolded protein response-mediated signaling pathway and inhibiting the endoplasmic reticulum stress-mediated neuronal apoptosis pathway.


Asunto(s)
Fármacos Neuroprotectores , Enfermedad de Parkinson , Ratones , Masculino , Animales , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo , Endorribonucleasas/metabolismo , Chaperón BiP del Retículo Endoplásmico , Caspasa 12/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Ratones Endogámicos C57BL , Estrés del Retículo Endoplásmico , Respuesta de Proteína Desplegada , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Modelos Animales de Enfermedad
12.
J Environ Sci (China) ; 24(7): 1181-8, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23513437

RESUMEN

Photo-production of dissolved inorganic carbon (DIC) from chromophoric dissolved organic matter (CDOM) is an important transformation process in marine carbon cycle, but little is known about this process in Chinese coastal systems. This study investigated an estuarine water sample and a coastal seawater sample from the subtropical waters in southeast of China. Water samples were exposed to natural sunlight and the absorption and fluorescence of CDOM as well as the DIC concentration were measured in the summer of 2009. The estuarine water had higher CDOM level, molecular weight and proportion of humic-like fluorescent components than the seawater that exhibited abundant tryptophan-like fluorescent component. After a 3-day irradiation, the CDOM level decreased by 45% in the estuarine water and 20% in the seawater, accompanied with a decrease in the molecular weight and aromaticity of DOM which was inferred from an increase in the absorption spectral slope parameter. The photo-degradation rates of all the five fluorescent components were also notable, in particular two humic-like components (C4 and C5) were removed by 78% and 69% in the estuarine water and by 69% and 56% in the seawater. The estuarine water had a higher photo-production rate of DIC than the seawater (4.4 vs. 2.5 micromol/(L x day)), in part due to its higher CDOM abundance. The differences in CDOM compositions between the two types of waters might be responsible for the higher susceptibility of the estuarine water to photo-degradation and hence could also affect the photo-production process of DIC.


Asunto(s)
Ciclo del Carbono , Carbono/análisis , Compuestos Orgánicos/química , Fotólisis , Agua de Mar/química , China , Fluorescencia , Agua de Mar/análisis , Espectrofotometría Ultravioleta
13.
Environ Sci Pollut Res Int ; 29(37): 56676-56683, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35347618

RESUMEN

Dissolved organic matter (DOM) is important for determining the speciation, environmental behavior, and effects of metal pollutants in aquatic environments. However, little is known about the difference between DOM from natural and anthropogenic sources for binding Pb(II). This study examined the Pb(II) binding with DOM from four typical sources including river, leaf litter leachate, and the influent and effluent of a wastewater treatment plant, using fluorescence quenching titration and excitation-emission matrices-parallel factor analysis (EEMs-PARAFAC). Four humic-like and one protein-like fluorescent components were identified, with much higher protein-like fraction and lower humification degree for the influent than for other sources. In the river water and leaf litter leachate, the abundant humic-like components were quenched by 6-17% while the protein-like component kept stable (2-4%) by the addition of Pb(II). In contrast, the influent DOM showed stronger fluorescence quenching of the protein-like component (46%) with higher conditional stability constant and binding fraction of fluorophore than the humic-like components (15-21%). The effluent DOM displayed weak quenching for all fluorescent components (4-6%) and thus weak complexation with Pb(II), indicating notable changes in the chemical composition and metal-binding affinity of DOM by wastewater treatments. These results demonstrated significant impacts of DOM source and chemical composition on its Pb(II) complexation properties, which have implications for understanding the interactions between DOM and heavy metals.


Asunto(s)
Materia Orgánica Disuelta , Sustancias Húmicas , Colorantes/análisis , Análisis Factorial , Sustancias Húmicas/análisis , Plomo/análisis , Ríos/química , Espectrometría de Fluorescencia/métodos
14.
Artículo en Inglés | MEDLINE | ID: mdl-36361148

RESUMEN

Chromophoric dissolved organic matter (CDOM) plays important roles in aquatic environments, and its optical properties provide a series of indices for evaluating the source and composition of dissolved organic matter (DOM). However, little is known about the varying photodegradation of CDOM from different sources and the effects on the optical indices of DOM composition. This was studied for typical natural and anthropogenic sources (plant and leaf litter leachates, the influent and effluent of a wastewater treatment plant, and a river). The CDOM absorption (a280) showed a lower degradability for the plant leachate than other sources, mainly due to its low molecular weight and aromaticity. Four fluorescent components were identified with excitation-emission matrices-parallel factor analysis (EEMs-PARAFAC), namely benzoic acid/monolignol-like C1, humic-like C2 and C3, and tryptophan-like C4. The plant leachate contained mainly C1, which was photodegraded moderately, while other sources had more C2 and C3 with higher photodegradability. C4 was photodegraded in most sources but was photoproduced in the leaf litter leachate. The absorption slope (S275-295) and slope ratio (SR) increased while the humification index (HIX) decreased, suggesting a decreasing molecular weight and humic content by photodegradation. This was consistent with the decreasing %C2 and %C3 but increasing %C4, which indicated preferential removal of humic-like components. The %C1, %C2, biological index (BIX), and fluorescence index (FI) were less affected by photodegradation than other indices for most sources. These results have implications for a better understanding of the photochemistry of CDOM and the applications of optical indices.


Asunto(s)
Materia Orgánica Disuelta , Compuestos Orgánicos , Compuestos Orgánicos/análisis , Fotólisis , Espectrometría de Fluorescencia , Ríos/química , China
15.
Chemosphere ; 307(Pt 2): 135875, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35932920

RESUMEN

Dissolved organic matter (DOM) can strongly influence the behavior and risk of metal pollutants in aquatic ecosystems. However, a comprehensive study on the effects of DOM level and environmental factors on the binding of DOM with Pb(II) is lacking. This study examined the DOM-Pb(II) interaction in the river water under variable DOM level, pH, and major ions, using fluorescence excitation-emission matrices-parallel factor analysis (EEMs-PARAFAC). Four humic-like and one protein-like component were identified, and the abundant humic-like components showed higher Pb(II)-binding fractions (f) than the protein-like component. The f of PARAFAC components decreased while the conditional stability constants (logKM) increased for the diluted DOM, indicating the influence of DOM level on its metal binding. The DOM-Pb(II) interaction was sensitive to changes in pH, with generally higher f and lower logKM at the alkaline condition due to changes in the DOM conformation. The addition of major ions significantly decreased the fluorescence quenching by Pb(II), due to competitive effects and potential DOM conformation changes at elevated ions. Overall, our results show that the DOM-Pb(II) complexation is highly dependent on both the DOM properties and environmental factors, which have implications for optimizing the experimental conditions and for comparing the results in different environments.


Asunto(s)
Contaminantes Ambientales , Sustancias Húmicas , Colorantes/análisis , Materia Orgánica Disuelta , Ecosistema , Contaminantes Ambientales/análisis , Análisis Factorial , Sustancias Húmicas/análisis , Iones , Plomo , Espectrometría de Fluorescencia/métodos , Agua
16.
Water Res ; 223: 118951, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-35994784

RESUMEN

Sediment organic matter (SOM) is important in the biogeochemical cycling of carbon, nutrients, and pollutants in the coastal environment, which is increasingly disturbed by aquaculture that is particularly intense in China. However, the identification of aquaculture signals in SOM is rather challenging in the complex coastal environment that receives materials from a variety of sources. This was studied in a typical culture area of shellfish and algae in SE China from July 2019 to October 2020, using a combination of elemental (OC, TN, N/C), isotopic (δ13C and δ15N), spectral (absorption spectroscopy and fluorescence EEMs-PARAFAC), and statistical analysis (principal component analysis, PCA). All indices of SOM quantity and several spectral indices for the SOM composition correlated significantly with grain size, with lower SOM quantity and higher autochthonous contribution in coarse sediments. The strong correlations between elemental and spectral indices suggested that optical analysis could provide valuable indices for assessing the quantity of bulk organic matter. The comparison of SOM indices between different zones and between different months showed an overall limited influence of shellfish and laver culture. This indicated the sustainability of these types of aquaculture that require no manual addition of feeds and thus are generally clean. The further applications of end-member mixing analysis using the IsoSource program and PCA were more sensitive, which identified the removal of SOM by shellfish in the growing season and the contribution from shellfish residuals after the harvest and the cultured laver at some locations. Overall, our results have implications for a better understanding of the biogeochemical processes and ecosystem sustainability in the coastal environment under intense aquaculture activities.


Asunto(s)
Contaminantes Ambientales , Sedimentos Geológicos , Acuicultura , Carbono , China , Ecosistema , Monitoreo del Ambiente , Sedimentos Geológicos/química
17.
Sci Total Environ ; 824: 153833, 2022 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-35151752

RESUMEN

In this study, a novel and low-cost seawater-modified biochar (SBC) was fabricated via the pyrolysis of fir wood waste followed by co-precipitation modification using seawater as the Ca/Mg source. The co-precipitation pH was a vital factor during modification, and the optimal pH was 10.50 according to calculations using PHREEQC 2.5 and experiments. The characterizations indicated that Ca and Mg were loaded on the SBC as irregular CaCO3 and nanoflake-like Mg(OH)2, respectively, with the latter dominating. The SBC exhibited a high maximum adsorption capacity of 181.07 mg/g for phosphate, calculated using the Langmuir model, excellent adsorption performance under acidic and neutral conditions (pH = 3.00-7.00), and remarkable selectivity against Cl-, NO3-, and SO42-. The presence of HCO3- promoted adsorption. The mechanisms behind phosphate adsorption involved electrostatic attraction, ligand exchange, precipitation, and inner-sphere complexation. Mg, rather than Ca, was served as the main adsorptive sites for phosphate. Additionally, the feasibility of treating real-world wastewater was tested in batch (using SBC powders) and fixed-bed column (using SBC granules) experiments. The results indicate that the SBC powders could reduce the phosphate concentration from 1.26 mg P/L to below 0.5 mg P/L at a low dose of 0.50 g/L, and the SBC granules exhibited a high removal efficiency with excellent recyclability; the capacity still remained at 78.92% of the initial capacity after five adsorption-desorption runs. Furthermore, the modification process almost did not increase the production cost of the SBC, which was estimated to be 0.41 $/kg. Our results demonstrate that seawater is a low-cost and efficient modifier for biochar modification, and the resultant SBC demonstrates great potential for treating actual phosphate-containing wastewater.


Asunto(s)
Aguas Residuales , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Cinética , Fosfatos , Polvos , Agua de Mar , Contaminantes Químicos del Agua/análisis
18.
Front Oncol ; 12: 979613, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36387121

RESUMEN

Objectives: To explore the feasibility of predicting the World Health Organization/International Society of Urological Pathology (WHO/ISUP) grade and progression-free survival (PFS) of clear cell renal cell cancer (ccRCC) using the radiomics features (RFs) based on the differential network feature selection (FS) method using the maximum-entropy probability model (MEPM). Methods: 175 ccRCC patients were divided into a training set (125) and a test set (50). The non-contrast phase (NCP), cortico-medullary phase, nephrographic phase, excretory phase phases, and all-phase WHO/ISUP grade prediction models were constructed based on a new differential network FS method using the MEPM. The diagnostic performance of the best phase model was compared with the other state-of-the-art machine learning models and the clinical models. The RFs of the best phase model were used for survival analysis and visualized using risk scores and nomograms. The performance of the above models was tested in both cross-validated and independent validation and checked by the Hosmer-Lemeshow test. Results: The NCP RFs model was the best phase model, with an AUC of 0.89 in the test set, and performed superior to other machine learning models and the clinical models (all p <0.05). Kaplan-Meier survival analysis, univariate and multivariate cox regression results, and risk score analyses showed the NCP RFs could predict PFS well (almost all p < 0.05). The nomogram model incorporated the best two RFs and showed good discrimination, a C-index of 0.71 and 0.69 in the training and test set, and good calibration. Conclusion: The NCP CT-based RFs selected by differential network FS could predict the WHO/ISUP grade and PFS of RCC.

19.
Cancer Imaging ; 22(1): 23, 2022 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-35549776

RESUMEN

BACKGROUND: Transcatheter arterial chemoembolization (TACE) is the mainstay of therapy for intermediate-stage hepatocellular carcinoma (HCC); yet its efficacy varies between patients with the same tumor stage. Accurate prediction of TACE response remains a major concern to avoid overtreatment. Thus, we aimed to develop and validate an artificial intelligence system for real-time automatic prediction of TACE response in HCC patients based on digital subtraction angiography (DSA) videos via a deep learning approach. METHODS: This retrospective cohort study included a total of 605 patients with intermediate-stage HCC who received TACE as their initial therapy. A fully automated framework (i.e., DSA-Net) contained a U-net model for automatic tumor segmentation (Model 1) and a ResNet model for the prediction of treatment response to the first TACE (Model 2). The two models were trained in 360 patients, internally validated in 124 patients, and externally validated in 121 patients. Dice coefficient and receiver operating characteristic curves were used to evaluate the performance of Models 1 and 2, respectively. RESULTS: Model 1 yielded a Dice coefficient of 0.75 (95% confidence interval [CI]: 0.73-0.78) and 0.73 (95% CI: 0.71-0.75) for the internal validation and external validation cohorts, respectively. Integrating the DSA videos, segmentation results, and clinical variables (mainly demographics and liver function parameters), Model 2 predicted treatment response to first TACE with an accuracy of 78.2% (95%CI: 74.2-82.3), sensitivity of 77.6% (95%CI: 70.7-84.0), and specificity of 78.7% (95%CI: 72.9-84.1) for the internal validation cohort, and accuracy of 75.1% (95% CI: 73.1-81.7), sensitivity of 50.5% (95%CI: 40.0-61.5), and specificity of 83.5% (95%CI: 79.2-87.7) for the external validation cohort. Kaplan-Meier curves showed a significant difference in progression-free survival between the responders and non-responders divided by Model 2 (p = 0.002). CONCLUSIONS: Our multi-task deep learning framework provided a real-time effective approach for decoding DSA videos and can offer clinical-decision support for TACE treatment in intermediate-stage HCC patients in real-world settings.


Asunto(s)
Carcinoma Hepatocelular , Quimioembolización Terapéutica , Aprendizaje Profundo , Neoplasias Hepáticas , Angiografía de Substracción Digital , Inteligencia Artificial , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/terapia , Quimioembolización Terapéutica/métodos , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/terapia , Estudios Retrospectivos , Resultado del Tratamiento
20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(2): 427-30, 2011 Feb.
Artículo en Zh | MEDLINE | ID: mdl-21510396

RESUMEN

The fluorescent components and their distribution and variation of dissolved organic matter (DOM) were examined using excitation emission matrix fluorescence spectroscopy-parallel factor analysis technique (EEMs-PARAFAC) for samples collected during June, 2008 from Minjiang River, a typical subtropical reservoir-type river ecosystem. Three separate fluorescent components were identified by PARAFAC, including two dominant humic-like components (C1: < 250, 325/424 nm; C2: 270, 395/482 nm) and one protein-like component (C3: < 250, 280/358 nm), of which humic-like components were dominant. Fluorescence analysis provided a 'fingerprint' technique to trace the mixing of DOM between three tributaries in the upstream of Minjiang River. The nearly constant concentration and composition in the main stream of Minjiang River reflected the effect of dam construction Correlation and principal component analysis (PCA) revealed that humic-like components were principally derived from flushing of watershed soils, while protein-like component was formed from in-situ production which could be used as a proxy of the concentration of total dissolved nitrogen (TDN). Multi-linear regression of fluorescent components C2 and C3 can be used to trace the variation of dissolved organic carbon (DOC) concentration. This study demonstrates that Minjiang is a typical subtropical reservoir-type river which still keeps relatively 'unpolluted' aquatic environment.


Asunto(s)
Compuestos Orgánicos/análisis , Ríos/química , Espectrometría de Fluorescencia/métodos , Análisis Factorial
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