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1.
Int J Biol Macromol ; 270(Pt 2): 132418, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38762994

RESUMO

With the gradual increase in environmental awareness and the growing demand for food safety, sustainable and environmentally friendly cellulose-based materials have become a promising alternative to petroleum-based plastics. However, in practice, packaging materials prepared from cellulose-based materials still have some unsatisfactory properties, such as monofunctionality, low transparency, and lack of UV shielding, antibacterial or antioxidant properties. Herein, a novel synthetic strategy is proposed in this paper, specifically, tannic acid (TA), a green natural extract with antibacterial and antioxidant properties, is used as a plasticizer and cross-linker, and oxidized cellulose nanocellulose (TOCN) modified with folic acid (FA) grafting is blended with TA, and cellulose-based biomass thin films with ultraviolet (UV) shielding, antibacterial, and antioxidant properties have been successfully prepared by using a simple vacuum-assisted filtration. The experimental results showed that the films could completely block ultraviolet light at wavelengths of 200-400 nm while providing 81.47 % transparency in the visible spectrum, while the introduction of TA conferred excellent antibacterial and antioxidant capabilities with antioxidant activity of up to 95 %, and also resulted in films with excellent mechanical properties. Therefore, this work provides ideas for the design and manufacture of competitive biomass green packaging materials, laying the foundation for future applications in food packaging.


Assuntos
Antibacterianos , Antioxidantes , Biomassa , Celulose , Taninos , Raios Ultravioleta , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Celulose/química , Taninos/química , Plásticos/química , Embalagem de Alimentos/métodos , Testes de Sensibilidade Microbiana
2.
Pestic Biochem Physiol ; 201: 105895, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38685222

RESUMO

In this study, the interaction of triazine herbicides with three kinds of different alkyl groups (simetryne, ametryn and terbutryn) with human serum albumin (HSA) are investigated through UV-vis, fluorescence, and circular dichroism (CD) spectra. The mechanisms on the fluorescence quenching of HSA initiated by triazine herbicides are obtained using Stern-Volmer, Lineweaver-Burk and Double logarithm equations. The quenching rate constant (Kq), Stern-Volmer quenching constant (Ksv), binding constant (KA), thermodynamic parameters such as enthalpy change (∆H), entropy change (∆S) and Gibbs free energy (∆G) and number of binding site (n) are calculated and compared. The variations in the microenvironment of amino acid residues are studied by synchronous fluorescence spectroscopy. The binding sites and subdomains are identified using warfarin and ibuprofen as site probes. The conformational changes of HSA are measured using CD spectra. The results reveal that the triazine herbicides with different alkyl groups can interact with HSA by static quenching. The combination of the three herbicides and HSA are equally proportional, and the binding processes are spontaneous. Hydrophobic interaction forces play important roles in simetryne-HSA and ametryn-HSA, while the interaction of terbutryn-HSA is Van der Waals forces and hydrogen bonding. Moreover, the three herbicides can bind to HSA at site I (sub-domain IIA) more than site II (subdomain IIIA), and combine with tryptophan (Trp) more easily than tyrosine (Tyr) residues, respectively. By comparison, the order of interaction strength is terbutryn-HSA > ametryn-HSA > simetryne-HSA. Terbutryn can destroy the secondary structure of HSA more than simetryne and ametryn, and the potential toxicity of terbutryn is higher. It is expected that the interactions of triazine herbicides with HSA via multi-spectral analysis can offer some valuable information for studying the toxicity and the harm of triazine herbicides on human health at molecular level in life science.


Assuntos
Herbicidas , Albumina Sérica Humana , Espectrometria de Fluorescência , Termodinâmica , Triazinas , Triazinas/química , Triazinas/metabolismo , Herbicidas/química , Herbicidas/metabolismo , Humanos , Albumina Sérica Humana/química , Albumina Sérica Humana/metabolismo , Dicroísmo Circular , Sítios de Ligação , Ligação Proteica , Interações Hidrofóbicas e Hidrofílicas
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 316: 124338, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38678839

RESUMO

In this work, the interaction between different chloro-substituted phenylurea herbicides (diuron (DIU) and chlortoluron (CHL)) and BSA were investigated and compared at three different temperatures (283 K, 298 K and 310 K) adopting UV-vis, fluorescence, and circular dichroism spectra. The quenching mechanism of the interaction was also proposed. The energy transfer between BSA and DIU/CHL was investigated. The binding sites of DIU/CHL and BSA and the variations in the microenvironment of amino acid residues were studied. The changes of the secondary structure of BSA were analyzed. The results indicate that both DIU and CHL can significantly interact with BSA, and the degree of the interaction between DIU/CHL and BSA increases with the increase of the DIU/CHL concentration. The fluorescence quenching of BSA by DIU/CHL results from the combination of static and dynamic quenching. The DIU/CHL has a weak to moderate binding affinity for BSA, and the binding stoichiometry is 1:1. Their binding processes are spontaneous, and hydrophobic interaction, hydrogen bonds and van der Waals forces are the main interaction forces. DIU/CHL has higher affinity for subdomain IIA (Site I) of BSA than subdomain IIIA (Site II), and also interacts with tryptophan more than tyrosine residues. The energy transfer can occur from BSA to DIU/CHL. By comparison, the strength of the interaction of DIU-BSA is always greater than that of CHL-BSA, and DIU can destroy the secondary structure of BSA molecules greater than CHL and thus the potential toxicity of DIU is higher due to DIU with more chlorine substituents than CHL. It is expected that this study on the interaction can offer in-depth insights into the toxicity of phenylurea herbicides, as well as their impact on human and animal health at the molecular level.


Assuntos
Herbicidas , Soroalbumina Bovina , Espectrometria de Fluorescência , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Herbicidas/química , Herbicidas/metabolismo , Animais , Bovinos , Diurona/química , Diurona/metabolismo , Espectrofotometria Ultravioleta , Sítios de Ligação , Ligação Proteica , Dicroísmo Circular , Transferência de Energia , Termodinâmica , Ligação de Hidrogênio
4.
Environ Pollut ; 347: 123805, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38493863

RESUMO

The effect of concentration and origin of dissolved organic matter (DOM) on acenaphthene (Ace) photodegradation in liquid water and ice was investigated, and the components in DOM which were involved in Ace photodegradation were identified. The DOM samples included Suwannee River fulvic acid (SRFA), Elliott soil humic acid (ESHA), and an effluent organic matter (EfOM) sample. Due to the production of hydroxyl radical (•OH) and triplet excited-state DOM (3DOM*) which react with Ace, DOM had promotion effects on Ace photodegradation. However, the promotion effects of DOM were prevailed over by their suppressing effect of DOM including screening light effect, intermediates reducing effect and RS quenching effect, and thus, the photodegradation rates of Ace decreased in the presence of the three DOM with concentrations of 0.5-7.5 mg C/L in liquid water and ice. ESHA had higher light absorption and thus had higher screening light effect on Ace photodegradation in liquid water than SRFA and EfOM. At each DOM concentration, ESHA exhibited higher promotion effect on Ace photodegradation than SRFA and EfOM, in liquid water and ice. The binding of Ace with DOM was indicated by decreases in fluorescence intensity of Ace when coexisted with DOM. However, the binding of Ace to DOM played an unimportant role in suppressing Ace photodegradation. The photodegradation behavior of fluorophores in Ace with DOM present in ice was not similar to that in liquid water. C-O, C═O, carboxyl groups O-H and aliphatic C-H functional groups in DOM were involved in the interaction of DOM with Ace. The presence of Ace seemed to have no influence on the photodegradation behavior of functional groups in DOM.


Assuntos
Poluentes Químicos da Água , Água , Fotólise , Gelo/análise , Matéria Orgânica Dissolvida , Acenaftenos , Solo , Substâncias Húmicas/análise , Poluentes Químicos da Água/química
5.
Int J Biol Macromol ; 263(Pt 2): 130087, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38342262

RESUMO

UV protection has become crucial as increasing environmental pollution has led to the destruction of the ozone layer, which has a weakened ability to block UV rays. In this paper, we successfully prepared cellulose-based biomass films with high UV shielding effect, high transparency and high tensile strength by graft-modifying oxidized cellulose nanocellulose (TOCN) with folic acid (FA) and borrowing vacuum-assisted filtration. The films had tunable UV shielding properties depending on the amount of FA added. When the FA addition was 20 % (V/V), the film showed 0 % transmittance in the UV region (200-400 nm) and 90.61 % transmittance in the visible region (600 nm), while the tensile strength was up to 150.04 MPa. This study provides a new integrated process for the value-added utilization of nanocellulose and a new route for the production of functional biomass packaging materials. The film is expected to be applied in the field of food packaging with UV shielding.


Assuntos
Celulose Oxidada , Celulose , Resistência à Tração
6.
Water Sci Technol ; 88(10): 2633-2645, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38017682

RESUMO

The effect of carboxyl and hydroxyl groups attached to the benzene ring on the photodegradation of anthracene (Ant) and pyrene (Pyr) in ice was investigated. The present study aims to explore the inhibition mechanism of five dissolved organic matter (DOM) model compounds' materials such as benzoic acid, o-hydroxybenzoic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, and 3-phenyl propionic acid on the degradation of Ant and Pyr in ice. The photodegradation rate of Ant and Pyr were 50.33 and 37.44% in ice, with the photodegradation rate of Ant being greater than that of Pyr. The five DOM model compounds inhibited the photolysis of Ant and Pyr, and the influence mechanism on the photodegradation of Ant and Pyr depended upon the types and positions of functional groups on the benzene. Among them, the structure in which the carboxyl group was directly connected to the benzene ring and carboxyl was located at the ortho position of a hydroxy group had a strong inhibitory effect on the photodegradation of Ant and Pyr. Light-screening effects and quenching effects were the main inhibiting mechanism, and the binding ability of DOM model compounds material and PAHs is dominantly correlated with its inhibiting effect.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Hidrocarbonetos Policíclicos Aromáticos/química , Gelo , Fotólise , Benzeno
7.
Water Res ; 246: 120714, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37837902

RESUMO

Dissolved organic matter (DOM) is an ubiquitous component of environmental snow and ice, which can absorb light and produce reactive species (RS) and thus is of importance in ice photochemistry. The photodegradation of sulfachloropyridazine (SCP) without and with DOM present in liquid water and ice were investigated in this study. The photodegradation rate constants for SCP without DOM present was enhanced by 52.5 % in ice relative to liquid water, likely due to the enhanced role of SCP self-sensitized RS in ice. DOM significantly promoted SCP photolysis in both liquid water and ice, which was mainly attributed to roles of singlet oxygen (1O2) and triplet excited-state DOM (3DOM*) generated from DOM. 1O2 production from DOM was significantly enhanced in ice relative to liquid water. Hydroxyl radical (•OH) production from DOM in ice was similar to those in liquid water. Enhancement in 3DOM* production in ice was observed at low DOM concentrations. Suwannee River Fulvic Acid (SRFA) and Elliott Soil Humic Acid (ESHA) exhibited differences in RS production in liquid water and ice, as well as in enhancement of 1O2 and 3DOM* produced in ice relative to liquid water. DOM induced reaction pathways of SCP different from those without DOM present, and therefore affected toxicity of SCP photoproducts. There were differences in photodegradation pathways of SCP as well as in toxicity of SCP photoproducts between liquid water and ice.


Assuntos
Sulfacloropiridazina , Poluentes Químicos da Água , Água , Fotólise , Gelo , Matéria Orgânica Dissolvida
8.
J Synchrotron Radiat ; 29(Pt 6): 1446-1453, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36345753

RESUMO

A new quick-scanning extended X-ray absorption fine-structure (QEXAFS) system for in situ studies has been developed and tested on the general XAFS beamline at the Shanghai Synchrotron Radiation Facility. In the new system, an analog-to-digital converter (ADC) with 1 MHz sampling rate is used to acquire the detector data while one scaler is used to precisely calculate the scanning energy. Two external hardware trigger signals were adopted to synchronize the data collection of the ADC and the scaler. The software development platforms of the double-crystal monochromator control system and the new QEXAFS system have been unified with the Experimental Physics and Industrial Control System. By comparing the spectra acquired by the conventional step-by-step XAFS system with an energy range of 1200 eV at the 7.5um Cu foil K-edge, the new system demonstrates satisfactory signal-to-noise ratio and energy resolution. The previous shortcomings, including distortion of the spectrum and energy shift, have been overcome. The tests with different integration times indicated that appropriate parameters not only ensure good experimental results but also enhance the smoothness of the XAFS spectrum at high energy zones. The reliability of the new system has also been verified.

11.
Environ Res ; : 110475, 2020 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-33197419

RESUMO

This article has been withdrawn at the request of the authors. Zhaohong Zhang is listed as an author on the manuscript but has informed the journal that this occurred without their consent or knowledge of the submission, and the email address provided was fake. Zhaohong Zhang does not support the scientific conclusions of the article. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

12.
Sci Rep ; 10(1): 3413, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32099003

RESUMO

Toxicity and transformation process of polycyclic aromatic hydrocarbons (PAHs) is strongly depended on the interaction between PAHs and dissolved organic matters (DOM). In this study, a 125W high-pressure mercury lamp was used to simulate the sunlight experiment to explore the inhibition mechanism of four dissolved organic matters (SRFA, LHA, ESHA, UMRN) on the degradation of anthracene and pyrene in water environment. Results indicated that the photodegradation was the main degradation approach of PAHs, which accorded with the first-order reaction kinetics equation. The extent of degradation of anthracene and pyrene was 36% and 24%, respectively. DOM influence mechanism on PAHs varies depending upon its source. SRFA, LHA and ESHA inhibit the photolysis of anthracene, however, except for SRFA, the other three DOM inhibit the photolysis of pyrene. Fluorescence quenching mechanism is the main inhibiting mechanism, and the binding ability of DOM and PAHs is dominantly correlated with its inhibiting effect. FTIR spectroscopies and UV-Visible were used to analyze the main structural changes of DOM binding PAHs. Generally, the stretching vibration of N-H and C-O of polysaccharide carboxylic acid was the key to affect its binding with anthracene and C-O-C in aliphatic ring participated in the complexation of DOM and pyrene.

13.
J Hazard Mater ; 375: 161-173, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31055193

RESUMO

A novel Z-scheme system, Ag/ZnFe2O4/Ag/BiTa1-xVxO4 with enhanced electron transfer capacity was constructed for degrading sulfanilamide (SAM) using solar light. The photocatalytic activity of Ag/ZnFe2O4/Ag/BiTa1-xVxO4 was investigated. The effects of the mass ratio (ZnFe2O4:BiTaO4), doped V dose, Ag wt.% content, and irradiation time on the catalytic performance were evaluated. The reasonable mechanism of Ag/ZnFe2O4/Ag/BiTa1-xVxO4 solar photocatalytic degradation was also presented. These results reveal Ag/ZnFe2O4/Ag/BiTa1-xVxO4 possesses enhanced photocatalytic performance. The loaded Ag as electron mediator increases the electron transfer rate. Particularly, the doped V and the Fe ions from ZnFe2O4 form a powerful electron driving force, which enhances the electron transfer capacity. Ag/ZnFe2O4/Ag/BiTa1-xVxO4 shows optimal photocatalytic performance at 2.0 wt.% Ag and 0.5% doped V dose (ZnFe2O4:BiTaO4 = 1.0:0.5). Also, Ag/ZnFe2O4/Ag/BiTa1-xVxO4 exhibits high stability and repeatability in photocatalytic degradation. Several active species (•OH, •O2-, and h+) are produced in the Z-scheme photodegradation of SAM. These results on the enhanced photocatalytic activity of Ag/ZnFe2O4/Ag/BiTa1-xVxO4 are ascribed to synergistic photocatalytic effects of ZnFe2O4 and BiTa1-xVxO4 mediated through Ag and driven by doped V and Fe ions. Therefore, the Z-scheme Ag/ZnFe2O4/Ag/BiTa1-xVxO4 photocatalytic technology proves to be promising for the solar photocatalytic treatment of antibiotics under solar light.


Assuntos
Antibacterianos/química , Compostos Férricos , Metais Pesados , Nanocompostos , Óxidos , Sulfanilamida/química , Compostos de Zinco , Catálise , Compostos Férricos/química , Compostos Férricos/efeitos da radiação , Metais Pesados/química , Metais Pesados/efeitos da radiação , Nanocompostos/química , Nanocompostos/efeitos da radiação , Oxirredução , Óxidos/química , Óxidos/efeitos da radiação , Fotólise , Luz Solar , Compostos de Zinco/química , Compostos de Zinco/efeitos da radiação
14.
J Hazard Mater ; 361: 30-36, 2019 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-30176413

RESUMO

The effect of dissolved organic matter (DOM) fractions on photodegradation of phenanthrene (PHE) in ice was investigated. DOM in surface water and wastewater samples was fractionated using XAD-8/XAD-4 resins into five fractions: hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), transphilic acid (TPI-A), transphilic neutral (TPI-N) and hydrophilic fraction (HPI). The photodegradation rate of PHE in ice was about 40% greater than that in water. The screening effect and quenching effect contributed 3-12% and 88-97% toward the inhibition of DOM fractions on PHE photodegradation in ice, respectively. The contribution ratios of singlet oxygen (1O2) and hydroxyl radical (OH) produced from DOM fractions to PHE photodegradation rates in ice were 9-31% and 2-13%, respectively. Among five DOM fractions, HPO-A was most efficient in advancing PHE photodegradation in ice through 1O2 mechanism. When excluding the photosensitized effect of 1O2 and OH produced from DOM fractions, the quencing effect of DOM fractions on PHE photodegradation in ice was closely related to their PHE binding ability.

15.
J Hazard Mater ; 350: 1-9, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29448208

RESUMO

In this study, novel spinel-NiFe2O4/natural mineral (sepiolite, diatomite and kaolinite) composites were developed using microwave (MW) hydrothermal method, and applied in MW-induced catalytic degradation (NiFe2O4/natural mineral/MW) of organic pollutants such as sodium dodecyl benzene sulfonate (SDBS), azo fuchsine (AF), methyl parathion (MP), and crystal violet (CVL) in solution. Catalytic activities of three NiFe2O4/natural mineral composites were compared. The effects of material synthesis process parameters such as molar ratios of NiFe2O4 and natural mineral, and pH of precursor solutions for synthesizing catalysts, and degradation parameters such as MW irradiation time and catalyst reuse cycles were also investigated. The principle on NiFe2O4/natural mineral/MW degradation was provided. The results reveal that organic pollutants in wastewater can be removed completely using NiFe2O4/natural mineral/MW within minutes. NiFe2O4/sepiolite shows higher catalytic activity than the others. The calculated degradation rate constants are 1.865, 0.672, 0.472, and 0.329 min-1 for SDBS, AF, MP, and CVL, respectively, using NiFe2O4/sepiolite/MW system. The performance of NiFe2O4/natural mineral can be maintained for three reuse cycles. Active species OH, O2-, and h+ play main roles in NiFe2O4/sepiolite/MW degradation. Hence, NiFe2O4/sepiolite/MW technology with rapid and cost-effective degradation, magnetic separation, and no secondary pollution, demonstrates to be promising in treating organic contaminants in wastewater.

16.
Chemosphere ; 179: 395-404, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28377117

RESUMO

The reductions of dissolved organic matter (DOM) and disinfection byproduct precursors in four full-scale wastewater treatment plants (WWTPs) (Liaoning Province, China) where different biological treatment processes were employed in winter were investigated. The total removal efficiencies of dissolved organic carbon (DOC), ultraviolet light at 254 nm (UV-254), trihalomethane formation potential (THMFP), and haloacetic acid formation potential (HAAFP) were in the range of 70.3-76.0%, 49.6-57.3%, 54.4-65.0%, and 53.7-63.8% in the four WWTPs, respectively. The biological treatment was the predominant process responsible for the removal of DOC, THMFP, and HAAFP in WWTPs. Differences in the reduction of UV-254 were not significant (p > 0.05) among biochemical reaction pool, secondary sedimentation tank, and disinfection tank. Biological aerated filter and suspended carrier activated sludge processes achieved higher DOM removal than the conventional active sludge and anaerobic-anoxic-oxic processes. Hydrophobic neutral and hydrophilic fraction were removed to a higher degree through biological treatment than the other three DOM fractions. HAAFP removal was more efficient than THMFP reduction during biological treatment. During primary treatment, fluorescent materials in secondary sedimentation tanks were preferentially removed, as compared to the bulk DOM. Humic-like fluorescent compounds were not readily eliminated during biological treatment. The fluorescent materials were more susceptible to chlorine than nonfluorescent compounds.


Assuntos
Desinfecção/métodos , Águas Residuárias/química , Purificação da Água/métodos , Biodegradação Ambiental , China , Cloro/farmacologia , Compostos Orgânicos/química , Esgotos , Trialometanos/análise , Raios Ultravioleta
17.
Cancer Immunol Immunother ; 66(6): 717-729, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28246881

RESUMO

Non-Hodgkin lymphoma (NHL) is an incurable lymphoproliferative cancer, and patients with NHL have a poor prognosis. The present study explored the regulatory mechanism of expression and possible roles of the immunosuppressive B7-H4 molecule in human NHL. For functional studies, NHL-reactive T cell lines were generated via the isolation of allogeneic CD3+ T cells from healthy donors and repeated in vitro stimulation with irradiated NHL cells isolated from patients. B7-H4 was found to be distributed in NHL cells and tissues, and its surface protein expression levels were further upregulated by the incubation of NHL cells with interleukin (IL)-6, IL-10, or interferon-γ. Additionally, the supernatants of tumor-associated macrophages (tMφs) upregulated B7-H4 surface expression by producing IL-6 and IL-10. B7-H4 expressed in NHL cells inhibited the cytotoxic activity of NHL-reactive T cells. Conversely, the inhibition of B7-H4 in NHL cells promoted T cell immunity and sensitized NHL cells to cytolysis. Furthermore, tMφs induced B7-H4 promoted NHL cell evasion of the T cell immune response. In conclusion, this study shows that NHL-expressed B7-H4 is an important immunosuppressive factor that inhibits host anti-tumor immunity to NHL. Targeting tumor-expressed B7-H4 may thus provide a new treatment strategy for NHL patients.


Assuntos
Interleucina-10/metabolismo , Interleucina-6/metabolismo , Linfoma não Hodgkin/imunologia , Linfoma não Hodgkin/metabolismo , Macrófagos/imunologia , Linfócitos T Reguladores/imunologia , Evasão Tumoral , Inibidor 1 da Ativação de Células T com Domínio V-Set/metabolismo , Comunicação Celular/imunologia , Humanos , Linfoma não Hodgkin/patologia , Células Tumorais Cultivadas
18.
Chemosphere ; 168: 599-605, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27838032

RESUMO

In this study, the interaction between DNA and several cationic surfactants with different head groups such as ethyl hexadecyl dimethyl ammonium bromide (EHDAB), hexadecyl dimethyl benzyl ammonium chloride (HDBAC), and cetyl pyridinium bromide (CPB) were investigated by UV-vis absorption, fluorescence and circular dichroism (CD) spectroscopy, gel electrophoresis, and viscosity technologies. The results show that these cationic surfactants can interact with DNA and major binding modes are electrostatic and hydrophobic. Also, CPB and HDBAC molecules interact with DNA by partial intercalation, and CPB has slightly stronger intercalation than HDBAC, while EHDAB interacts with DNA by non-intercalation. The different head groups of the surfactant molecules can influence the interaction strength. CPB has the stronger interaction with DNA than the others. Moreover, surfactant concentration, the ratio of DNA and fluorescence probe, ionic strength can influence the interaction. The surfactants may interact with DNA by the competition reactions with BR for DNA-BR. The increase of ionic strength may favor the surface binding between DNA and surfactants to some extent. This work provides deep mechanistic insight on the toxicity of cationic surfactants with different head groups to DNA molecules.


Assuntos
DNA/química , Disruptores Endócrinos/química , Poluentes Ambientais/química , Substâncias Intercalantes/química , Tensoativos/química , Brometos/química , Dicroísmo Circular , Eletroforese em Gel de Ágar , Corantes Fluorescentes , Interações Hidrofóbicas e Hidrofílicas , Concentração Osmolar , Compostos de Amônio Quaternário/química , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Eletricidade Estática , Viscosidade
19.
Surg Endosc ; 30(11): 5099-5107, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27005293

RESUMO

INTRODUCTION: Endoscopic submucosal dissection (ESD) has been used for the treatment of gastric submucosal tumors (SMTs). This study aims to compare clinical outcomes of ESD versus laparoscopic wedge resection (LWR) for gastric SMTs. METHODS: This is a retrospective cohort study. Patients with SMTs who underwent ESD or LWR were enrolled in this study at a university-affiliated hospital from January 2010 to October 2015. Preoperative endoscopic ultrasound and computed tomography were performed to determine origin of layer and growth pattern. Clinical outcomes including baseline demographics, tumor size, operation time, blood loss, hospital stay, cost, pathology and postoperative complications were compared. RESULTS: From January 2010 to October 2015, 68 patients with SMTs received ESD and 47 patients with SMTs received LWR. There was no difference in age, gender, body mass index, origin of layer and proportion with symptoms between ESD group and LWR group. However, tumor size was significantly larger in the LWR group (37.1 mm) than in the ESD group (25.8 mm, P = 0.041). For patients with tumors smaller than 20 mm, ESD was associated with shorter mean operation time (89.7 ± 23.5 vs 117.6 ± 23.7 min, P = 0.043), less blood loss (4.9 ± 1.7 vs 72.3 ± 23.3 ml, P < 0.001), shorter length of hospital stay (3.6 ± 1.9 vs 6.9 ± 3.7 days, P = 0.024) and lower cost (2471 ± 573 vs 4498 ± 1257 dollars, P = 0.031) when compared with LWR. For patients with tumors between 20 mm and 50 mm, ESD was associated with shorter mean operation time (99.3 ± 27.8 vs 125.2 ± 31.5 min, P = 0.039), less blood loss (10.1 ± 5.3 vs 87.6 ± 31.3 ml, P < 0.001), shorter length of hospital stay (4.0 ± 1.7 vs 7.3 ± 4.5 days, P = 0.027) and lower cost (2783 ± 601 vs 4798 ± 1343 dollars, P = 0.033) when compared with LWR. There were no significant differences in terms of rates of en bloc resection, complete resection and complication and histological diagnosis regardless of tumor size. CONCLUSIONS: ESD can achieve similar oncological outcomes when compared with surgery for treatment of gastric SMT smaller than 50 mm.


Assuntos
Tumores do Estroma Gastrointestinal/cirurgia , Músculo Liso/patologia , Neoplasias Gástricas/cirurgia , Estudos de Coortes , Ressecção Endoscópica de Mucosa/métodos , Feminino , Mucosa Gástrica/cirurgia , Gastroscopia/métodos , Humanos , Laparoscopia/métodos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Retrospectivos , Resultado do Tratamento
20.
J Hazard Mater ; 310: 226-34, 2016 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-26937869

RESUMO

In this study, a new catalytic degradation technology using microwave induced carbon nanotubes (MW/CNTs) was proposed and applied in the treatment of organic pollutants in aqueous solution. The catalytic activity of three CNTs of 10-20nm, 20-40nm, and 40-60nm diameters were compared. The results showed that organic pollutants such as methyl orange (MO), methyl parathion (MP), sodium dodecyl benzene sulfonate (SDBS), bisphenol A (BPA), and methylene blue (MB) in aqueous solution could be degraded effectively and rapidly in MW/CNTs system. CNTs with diameter of 10-20nm exhibited the highest catalytic activity of the three CNTs under MW irradiation. Further, complete degradation was obtained using 10-20nm CNTs within 7.0min irradiation when 25mL MO solution (25mg/L), 1.2g/L catalyst dose, 450W, 2450MHz, and pH=6.0 were applied. The rate constants (k) for the degradation of SDBS, MB, MP, MO and BPA using 10-20nm CNTs/MW system were 0.726, 0.679, 0.463, 0.334 and 0.168min(-1), respectively. Therefore, this technology may have potential application for the treatment of targeted organic pollutants in wastewaters.

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