Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Langmuir ; 40(28): 14368-14383, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-38954527

RESUMEN

The synergistic treatment of oily wastewater containing organic hazards and emulsified oils remains a big challenge for membrane separation technology. Herein, the photocatalytic membrane, which combined the physical barrier and catalytic oxidation-driven degradation functionality, was fabricated via anchoring a nanoflower-branched CoAl-LDH@PANI Z-scheme heterojunction onto a porous polyacrylonitrile mat and using tannic acid as an adhesive. The assembly of such a Z-scheme heterojunction offered the superior photocatalytic degradation performance of soluble dyes and tetracycline (up to 94.3%) to the membrane with the improved photocatalytic activity of 2.33 times compared with the CoAl-LDH@pPAN membrane. Quenching experiments suggested that the •O2- was the most reactive oxygen species in the catalytic reaction system of the composite membrane. The greatly enhanced photocatalytic activity was attributed to the effective inhibition of photogenerated hole-electron combination using PANI as a carrier, with charge transferring from LDH to PANI. The possible photocatalytic degradation mechanism was proposed based on VB-XPS, electron spin resonance spectroscopy, and DRS technologies, which was confirmed by density functional theory calculation. Meanwhile, benefiting from the superhydrophilic/oleophobic feature and low oil adhesion, the membrane exhibited high permeability for isooctane emulsion (3990.39 L·m-2·h-1), high structure stability, and satisfactory cycling performance. This work provided a strategy to develop superwetting and photocatalytic composite membranes for treating complex multicomponent pollutants in the chemical industry.

2.
J Hazard Mater ; 473: 134615, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38761768

RESUMEN

Naturally strong ultraviolet irradiation at high altitudes causes photobleaching of plateau lake DOM (P-DOM) and affects its photochemical activity. However, the photoreactivity of P-DOM has remained unclear under natural photobleaching condition. Here, six P-DOM samples isolated from plateau lakes in Yunnan Province, China as well as two reference DOM as comparisons were used to explore the photogeneration of reactive species (RS) and their effects on 17ß-estradiol photodegradation. Compared with SRHA/SRFA, P-DOM has lower aromaticity, average molecular weight, and electron-donating capacity. The quantum yields of triplet state P-DOM (3P-DOM*), 1O2, and ∙OH produced in P-DOM solutions were greatly higher than those of reference DOM. The RS quantum yields had positive linear correlations with E2/E3 and SR, whereas were negatively linear correlated with SUVA25. Radical quenching experiments showed that 3P-DOM* was the prominent RS for 17ß-estradiol photodegradation, and its contribution exceeded 70% for each of P-DOM. 3P-DOM*-mediated photodegradation was mainly attributed to the electron-transfer reactions with an average second-order rate constant of 4.62 × 109 M-1s-1, indicating the strong photoreactivity towards 17ß-estradiol. These findings demonstrate that P-DOM is an efficient photosensitizer for RS production, among which 3P-DOM* may play an important role in enhanced photodegradation for organic micropollutants in plateau lake enriched with DOM.

3.
J Chem Phys ; 139(7): 074704, 2013 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-23968104

RESUMEN

Grand canonical Monte Carlo (GCMC) and liquid-vapor molecular dynamics (LVMD) simulations are performed to investigate the squeezing and phase transition of a simple liquid argon film confined between two solid surfaces. Simulation results show that the LVMD simulation is capable of capturing the major thermodynamic equilibrium states of the confined film, as predicted by the GCMC simulations. Moreover, the LVMD simulations reveal the non-equilibrium squeeze out dynamics of the confined film. The study shows that the solvation force hysteresis, observed in many surface force experiments, is attributed to two major effects. The first is related to the unstable jumps during the laying transitions of the confined film, in which the gradient of force profile is larger than the driving spring constant. The second effect is related to the squeeze out dynamics of the confined film even though the first effect is absent. In general, these two dynamic processes are non-equilibrium in nature and involve significant energy dissipations, resulting in the force hysteresis.

4.
Comb Chem High Throughput Screen ; 26(3): 595-609, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35598238

RESUMEN

BACKGROUND: Endometrial cancer is ranked fourth in women's cancers worldwide. SUMOylation is a process of post-translational modification and some evidence indicate that SUMOylation may influence the occurrence and development of cancer. Until now, the prognostic value of SUMOylation-related genes in endometrial cancer remains unclear. Therefore, we aimed at exploring the prognostic value of SUMOylation-related genes in endometrial cancer in this study. METHODS: The transcriptome of endometrial cancer from TCGA database was downloaded and then differentially expressed SUMOylation-related genes were extracted. The risk model was constructed with the use of the least absolute shrinkage and selection operator Cox regression. Samples were divided into low-risk and high-risk group based on the risk score. Survival analysis and Cox analysis were performed between groups. A validation cohort from Fudan University Shanghai Cancer Center were obtained to verify the model. Gene ontology and Kyoto Encylopedia of Genes and Genomes analyses were conducted based on differentially expressed genes between groups. RESULTS: Samples in low-risk group possess better outcome than in high-risk group. (P<0.001) The results of univariate (P<0.001) and multivariate (P=0.018) analysis showed that the risk score was independently correlated to worse outcome for patients with endometrial cancer. In Fudan University Shanghai Cancer Center validation cohort, the low-risk group possessed better survival outcome than the high-risk group (P=0.0393). Functional analysis demonstrated that most of the immune cell infiltration levels and immune pathways activity in low-risk group were higher than in high-risk group. CONCLUSIONS: In short, the SUMOylation-related signature had good predictability in endometrial cancer and SUMOylation-related genes play important roles in tumour immunity. Also, our study might have some merits in elucidating potential mechanism of SUMOylation in endometrial cancer.


Asunto(s)
Neoplasias Endometriales , Sumoilación , Humanos , Femenino , Sumoilación/genética , China , Neoplasias Endometriales/genética , Factores de Riesgo , Bases de Datos Factuales
5.
Langmuir ; 28(6): 3152-8, 2012 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-22242704

RESUMEN

We performed molecular dynamics simulations to investigate hydrophobic interactions between two parallel hydrophobic plates immersed in water. The two plates are separated by a distance D ranging from contact to a few nanometers. To mimic the attractive hydrophobic force measurement in a surface force experiment, a driving spring is used to measure the hydrophobic force between two hydrophobic plates. The force-distance curves, in particular the force variations from spontaneous drying to hydrophobic collapse are obtained. These details are usually not accessible in the surface force measurement due to the unstable jump into contact. The length-scale effect on the hydrophobic drying during normal approach and the hydrophobic hysteresis during retraction has been studied. We find that the critical distance at which a spontaneous drying occurs is determined by the shorter characteristic dimension of the plate, whereas the hydrophobic hysteresis is determined by the longer characteristic dimension of the plate. The variations of the potential of mean force versus separation during approach and retraction are also calculated. The results show that water confined between two parallel hydrophobic plates is in a thermodynamic metastable state. This comparably high energy state leads to the spontaneous drying at some critical distance.

6.
Sci Total Environ ; 815: 152934, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35007586

RESUMEN

The triplet excited state of dissolved organic matter (3DOM⁎) is highly effective in the photodegradation of a broad spectrum of trace organic pollutants (TOPs), and its photoactivity is affected by concomitant metal ions in surface waters. However, the impact of environmental metal ions on the 3DOM⁎-induced photodegradation of TOPs has not been systemically explored. Herein, we investigated the effect of environmental Cu2+ on the 3DOM⁎-induced photodegradation kinetics of 16 TOPs. A fluorescence quenching experiment showed that a Cu(II)-DOM complex was formed. For the TOPs with stronger electron-donating groups (triplet-labile moieties, e.g., phenols and anilines), Cu2+ complexation notably inhibited 3DOM⁎-induced photodegradation. This may be ascribed to the decrease of 3DOM⁎ steady-state concentration because Cu2+ complexation reduces its formation rates and enhances scavenging rates tested by sorbic acid isomerization experiment. Meanwhile, it was found that Cu2+ complexation facilitated the photolysis of refractory TOPs (lower triplet reactivity) because of enhanced electron transfer between DOM and Cu(II), causing photoinduced OH formation. These findings implied that 3DOM⁎ reactivity differences in TOPs could affect the photodegradation rates in the complex system, which was confirmed via a linear correlation of photodegradation rate ratios for 16 TOPs induced by 3DOM⁎ in the presence/absence of Cu2+ with their 3DOM⁎ reactivity. These findings helped to improve our understanding of the photochemical reactivity of 3DOM⁎ in natural waters, especially the effects of environmentally concomitant metal ions.


Asunto(s)
Contaminantes Ambientales , Contaminantes Químicos del Agua , Materia Orgánica Disuelta , Metales , Fotólisis
7.
Environ Sci Pollut Res Int ; 29(15): 21517-21527, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34766222

RESUMEN

Dissolved black carbon (DBC) is regarded as an important part of the natural organic matter pool. However, it is unclear about DBC's photochemical activity and the relationships between reactive intermediates (RIs) and the molecular structure of DBC remain unclear. In this study, we investigate the photochemical formation ability of RIs and spectral parameters (E2/E3, S275-295) of DBC made from five types of plants at five pyrolysis temperatures. The results showed that there were good linear regressions between the RI quantum yields and the spectral parameters (E2/E3, S275-295), and this was indicative of the RI generation prediction from DBC under solar irradiation. The DBC-mediated photochemical experiment of sulfadiazine revealed that 3DBC* was the primary active species for the indirect photodegradation of sulfadiazine. Further studies indicated that a linear relationship was observed between the indirect photodegradation ability of sulfadiazine induced directly by 3DBC* at different pyrolysis temperatures and the 3DBC* quantum yields or E2/E3. These findings indicate that the simple models of the RI quantum yield as a function of spectral parameters can be used to evaluate the degradation of pollutants with known DBC spectral parameters.


Asunto(s)
Luz Solar , Contaminantes Químicos del Agua , Carbono , Procesos Fotoquímicos , Fotólisis , Sulfadiazina , Contaminantes Químicos del Agua/análisis
8.
Phys Rev Lett ; 107(14): 147801, 2011 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-22107235

RESUMEN

Shearing of a simple nonpolar film, right after the liquid-to-solid phase transition under nanometer confinement, is studied by using a liquid-vapor molecular dynamics simulation method. We find that, in contrast with the shear melting and recrystallization behavior of the solidlike phase during the stick-slip motion, interlayer slips within the film and wall slips at the wall-film interface are often observed. The ordered solidified film is well maintained during the slip. Through the time variations of the frictional force and potential energy change within the film, we find that both the friction dissipation during the slip and the potential energy decay after the slip in the solidified film take a fairly large portion of the total energy dissipation.

9.
J Agric Food Chem ; 69(22): 6100-6118, 2021 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-34048228

RESUMEN

Agrometallomics, as an independent interdiscipline, is first defined and described in this review. Metallic elements widely exist in agricultural plants, animals and edible fungi, seed, fertilizer, pesticide, feedstuff, as well as the agricultural environment and ecology, and even functional and pathogenic microorganisms. So, the agrometallome plays a vital role in molecular and organismic mechanisms like environmetallomics, metabolomics, proteomics, lipidomics, glycomics, immunomics, genomics, etc. To further reveal the inner and mutual mechanism of the agrometallome, comprehensive and systematic methodologies for the analysis of beneficial and toxic metals are indispensable to investigate elemental existence, concentration, distribution, speciation, and forms in agricultural lives and media. Based on agrometallomics, this review summarizes and discusses the advanced technical progress and future perspectives of metallic analytical approaches, which are categorized into ultrasensitive and high-throughput analysis, elemental speciation and state analysis, and spatial- and microanalysis. Furthermore, the progress of agrometallomic innovativeness greatly depends on the innovative development of modern metallic analysis approaches including, but not limited to, high sensitivity, elemental coverage, and anti-interference; high-resolution isotopic analysis; solid sampling and nondestructive analysis; metal chemical species and metal forms, associated molecular clusters, and macromolecular complexes analysis; and metal-related particles or metal within the microsize and even single cell or subcellular analysis.


Asunto(s)
Metabolómica , Metales , Animales , Espectrometría de Masas , Plantas , Proteómica
10.
Water Res ; 202: 117445, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34303168

RESUMEN

The UV/chlorine system has been regarded as an efficient oxidation technology for the removal of aqueous micropollutants. However, the roles of the possible radical species for this system on the elimination under environmentally relevant conditions/real waters were still largely unknown. Herein, the specific roles of radical species in the UV/chlorine oxidation degradation of gemfibrozil and naproxen as representative micropollutants were quantified by a steady-state kinetic prediction model considering the effects of water matrices. Overall, the model predicted results are consistent with the experimental data well. •OH and reactive chlorine species (RCS, such as Cl•, ClO•, and Cl2•-) contributions to gemfibrozil and naproxen degradation were water matrix specific. In pure water, both primary reactive species (i.e., •OH and Cl•) and secondary species ClO• dominated gemfibrozil and naproxen degradation, and their individual and the sum of the contributions to degradation rates reduced with pH increase of from 5 to 9. In the presence of Cl-, we found that Cl2•- and in particular ClO• were responsible for the enhanced degradation with increasing Cl- concentrations due to the considerable ClO• reactivity of gemfibrozil (1.93 × 109 M-1 s-1) and naproxen (9.24 × 109 M-1 s-1) and the rapid transformation of Cl2•- to ClO•. The presence of HCO3- notably facilitated the degradation in the UV/chlorine process because of the generation of CO3•-. CO3•- showed high reactivity with gemfibrozil and naproxen corresponding to respective second-order reaction rate constants of 2.45 × 107 and 3.50 × 107 M-1 s-1. Dissolved organic matter induced obvious scavenging for •OH, Cl•, and ClO• and greatly retarded the degradation. The constructed model considering the effects of above water matrix has successfully predicted the oxidation degradation kinetics in real waters, and both •OH and CO3•- are the predominant reactive species in the degradation. This study is helpful for comprehensive understanding the roles of possible radical species in micropollutant removal by UV/chlorine oxidation under real water matrix.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Cloro , Gemfibrozilo , Cinética , Naproxeno , Oxidación-Reducción , Rayos Ultravioleta , Agua , Contaminantes Químicos del Agua/análisis
11.
Curr Probl Cancer ; 45(2): 100660, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33012523

RESUMEN

To explore the prognostic value of tumor mutation burden (TMB) and its correlation with immune infiltrates in endometrial cancer. Transcriptome and somatic mutation profiles of Uterine Corpus Endometrial Carcinoma (UCEC) were downloaded from TCGA database. Somatic mutations were analyzed by "maftools" and visualized in waterfall plot. We calculated TMB of each patients and divided all patients into the high-TMB group and the low-TMB group by the median threshold. Survival analysis and Wilcoxon test were used to investigate the prognostic value of TMB and its association with clinical variables. Differentially expressed genes (DEGs) were identified in 2 TMN groups and functional analysis was performed to find out significant biological pathways. A TMB-related signature was conducted by multivariate analysis, receiver operating characteristic (ROC) curve was performed to predict accuracy of the model, meanwhile, a validation cohort from Fudan University Shanghai Cancer Center (FUSCC) was obtained to verify the signature. Then we estimated association between TMB and immune infiltrates by CIBERSORT algorithm and figured out prognostic immune cells of UCEC in TIMER database. Total 575 samples including 25 normal tissues and 552 tumor samples were enrolled from TCGA database. PTEN mutations accounted for the most and single nucleotide polymorphism and C>T transitions were most frequent forms of somatic mutations in UCEC. The low-TMB group possessed worse survival than the high-TMB group (P = 0.004). DEGs in 2 TMB groups were mostly enriched in adaptive immune response and immunoglobulin/immune receptor component. A TMB-related signature consisting of GFAP, EDN3, CXCR3, PLXNA4, SST presented good predictability with area under the curve (AUC) = 0.686. In FUSCC validation cohort, the high-risk group possessed worse survival outcome than the low-risk group (P = 0.015). Immune infiltrates was correlated to survival in UCEC and low TMB were associated with less immune infiltrates, which suggested poor immune response. TMB was not only related to overall survival but also immune infiltrates in UCEC. The TMB-related signature (GFAP, EDN3, CXCR3, PLXNA4, SST) had good predictability for overall survival in endometrial cancer. Our study might have some merits in elucidating potential mechanism of TMB and immune infiltrates in UCEC and providing guidance of immunotherapy for endometrial cancer.


Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias Endometriales/genética , Mutación/genética , Adulto , Anciano , Anciano de 80 o más Años , China , Neoplasias Endometriales/inmunología , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Pronóstico , Análisis de Supervivencia
12.
Environ Pollut ; 276: 116692, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33592446

RESUMEN

Photodegradation is a major elimination route of many pharmaceutically active compounds (PhACs) in natural surface waters, yet their photolytic behavior in estuarine waters with salinity gradient change is largely unknown. Herein, sulfamethazine and carbamazepine were taken as representative PhACs to explore the photolytic kinetic differences in Qinzhou Bay estuarine water samples collected from upper to lower reaches. Rapid photodegradation of sulfamethazine was found in lower estuarine water relative to upstream estuarine water; whereas for carbamazepine, photolytic rate was inversely proportional to the salinity of estuarine waters. Experiments with extracted estuarine dissolved organic matter (E-DOM) imply that the multivariate effects of triplet-excited E-DOM (3E-DOM∗) and halide ions are responsible for the enhancement photolysis of sulfamethazine. Radical scavenging experiments suggest that the photolysis enhancement can be ascribed to the contribution of reactive halogen species (RHS), while their contribution to carbamazepine is negligible and 3E-DOM∗ is the dominant reactive species for its photodegradation. This indicates that the reactivity differences with RHS and 3DOM∗ affect the photolytic kinetics of PhACs from upper estuarine waters to lower reaches, which is also supported by a good linear relationship between the ratios of photolytic rates for ten PhACs in E-DOM solution with/without halides and the ratios of the reactivity of these pollutants with RHS and 3DOM∗. These findings show that the different reactivity of PhACs with 3E-DOM∗ and RHS influences the photolytic kinetics in estuarine waters with different salinity, and highlights the photochemical behavior of organic micropollutants from upstream to downstream estuarine waters.


Asunto(s)
Halógenos , Contaminantes Químicos del Agua , Cinética , Fotólisis , Sulfametazina
13.
Biosci Rep ; 40(11)2020 11 27.
Artículo en Inglés | MEDLINE | ID: mdl-33141168

RESUMEN

Tumor mutation burden (TMB) is an essential biomarker to predict immunotherapy response. TMB measurement was mainly evaluated by whole-exome sequencing (WES), which was costly and difficult to be widely applied. In the present study, we aimed to establish and validate a miRNA signature to predict TMB level in endometrial cancer using The Cancer Genome Atlas (TCGA) database. MiRNA expression and somatic mutation profiles of uterine corpus endometrial carcinoma (UCEC) were downloaded from TCGA database. Total 518 patients with UCEC were randomly classified into training set (n=311) and validation set (n=207). Thirty-five differentially expressed miRNAs between high-TMB and low-TMB group were identified in training set. Least absolute shrinkage and selection operator (LASSO) method was performed to select out 26 miRNAs to establish the optimal signature. The accuracy of the miRNA signature for predicting TMB level was 0.833 for training set, 0.749 for validation set and 0.799 for total set. Moreover, the miRNA signature had significant correlation with immune checkpoints related genes (PD-1, PD-L1, CTLA-4) and mismatch repair related genes (BRCA1, BRCA2, MLH1, MSH6) expression. In conclusion, this miRNA signature could predict TMB level in endometrial cancer and might have some merits in providing guidance for immunotherapy in endometrial cancer.


Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias Endometriales/genética , Perfilación de la Expresión Génica , MicroARNs/genética , Mutación , Transcriptoma , Anciano , Toma de Decisiones Clínicas , Análisis Mutacional de ADN , Bases de Datos Genéticas , Neoplasias Endometriales/inmunología , Neoplasias Endometriales/metabolismo , Neoplasias Endometriales/terapia , Femenino , Predisposición Genética a la Enfermedad , Humanos , Persona de Mediana Edad , Fenotipo , Medicina de Precisión , Valor Predictivo de las Pruebas , Pronóstico , Reproducibilidad de los Resultados
14.
ACS Appl Mater Interfaces ; 12(32): 36568-36577, 2020 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-32686398

RESUMEN

It is well-known that attractive electromagnetic interference (EMI) shielding performance depends on functional (e.g., electrical and magnetic) fillers and structural designs. This paper presents a novel three-layered sandwich structure of poly(vinylidene fluoride) (PVDF)-based nanocomposites, consisting of graphene nanoplatelets (GNP), nickel (Ni), and carbon nanotubes (CNT). The unique three-layered sandwich structure of GNP-Ni-CNT exhibited excellent EMI shielding ability due to the several interfaces of the multilayered structure with electric loss by the conductive fillers and magnetic loss by the magnetic filler. The overall shielding performance could be further improved by increasing the overall thickness and the number of layers. With a fixed thickness of 0.6 mm, the shielding effectiveness of the PVDF/GNP-Ni-CNT three-layered and six-layered structure composite at 15 GHz was 41.8 and 46.4 dB, respectively. These results provide a useful strategy to prepare various EMI shielding materials with a sandwich structure, presenting tremendous opportunities to design and manufacture advanced EMI shielding materials and equipment.

15.
Phys Rev E Stat Nonlin Soft Matter Phys ; 82(4 Pt 1): 040501, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21230229

RESUMEN

We use molecular dynamics simulations to explore the force oscillation mechanism of a simple fluid confined between two surfaces. Force profiles obtained through simulations are qualitatively similar to those in surface force measurements. Our results demonstrate that the layering transition is an abrupt, liquid-to-solid phase transition. The nucleation of solid phase starts at the central region of the confined film that can sustain a finite shear stress. The packing structure of the solid film is a hexagonal close-packed (hcp) crystalline structure, whose mechanical property is highly asymmetric. The elastic modulus and repulsive peaks of oscillatory forces during normal approach are always larger than those during retraction.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA