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1.
Microorganisms ; 12(1)2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38276177

RESUMO

Coal mining has caused significant soil nitrogen loss in mining areas, limiting reclamation and reuse in agriculture. This article studies the effects of organic fertilizer, inorganic fertilizer, and the combined application of Pseudomonas fluorescens with the ability of nitrogen fixation on soil nitrogen accumulation and composition in the reclamation area of the Tunlan Coal Mine from 2016 to 2022 under the conditions of equal nitrogen application, providing a scientific basis for microbial fertilization and the rapid increase in nitrogen content in the reclaimed soil of mining areas. The results showed that as the reclamation time increased, the nitrogen content and the composition and structure of the soil treated with fertilization rapidly evolved toward normal farmland soil. The soil nitrogen content increased most rapidly in the presence of added P. fluorescens + organic fertilizer (MB). Compared to other treatments (inorganic fertilizer (CF), organic fertilizer (M), and P. fluorescens + inorganic fertilizer (CFB)), MB increased total nitrogen (TN) to normal farmland soil levels 1-3 years earlier. The comprehensive scores of MB and CFB on the two principal components increased by 1.58 and 0.79 compared to those of M and CF treatments, respectively. This indicates that the combination of P. fluorescens and organic fertilizer improves soil nitrogen accumulation more effectively than the combination of P. fluorescens and inorganic fertilizer. In addition, the application of P. fluorescens increases the content of unknown nitrogen (UN) in acid-hydrolysable nitrogen (AHN) and decreases the content of amino acid nitrogen (AAN) and ammonia nitrogen (AN). However, there was no significant effect on the content of ammonium nitrogen (NH4+-N) and nitrate nitrogen (NO3--N) in soil-mineralized nitrogen (SMN). When combined with inorganic fertilizer, the contribution of SMN to TN increased by 14.78%, while when combined with organic fertilizer, the contribution of AHN to TN increased by 44.77%. In summary, the use of P. fluorescens is beneficial for nitrogen recovery in the reclaimed soil of coal-mining areas. The optimal fertilization method under the experimental conditions is the combination of P. fluorescens and organic fertilizer.

2.
Microorganisms ; 10(10)2022 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-36296258

RESUMO

Release of nanoceria (nCeO2) into the environment has caused much concern about its potential toxicity, which still remains poorly understood for soil microorganisms. In this study, nanoceria and cerium (III) nitrate at different doses (10, 100 and 500 mg/kg) were applied to bok choy (Brassica rapa subsp. chinensis), grown in potting soil, to investigate the responses of soil bacterial communities to nanoceria (NC) and ionic cerium (IC) applications. The results showed that bacterial richness was slightly increased in all cerium treatments relative to the negative control without cerium amendment (CK), but a significant increase was only found in IC500. The patterns of bacterial community composition, predicted functions and phenotypes of all NC treatments were significantly differentiated from IC and CK treatments, which was correlated with the contents of cerium, available potassium and phosphorus in soil. The co-occurrence network of bacterial taxa was more complex after exposure to ionic cerium than to nanoceria. The keystone taxa of the two networks were entirely different. Predicted functions analysis found that anaerobic and Gram-negative bacteria were enriched under nanoceria exposure. Our study implies that Proteobacteria and nitrifying bacteria were significantly enriched after exposure to nanoceria and could be potential biomarkers of soil environmental perturbation from nanoceria exposure.

3.
Environ Sci Technol ; 56(2): 896-906, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34983180

RESUMO

Bacterial extracellular polymeric substances (EPS) have been recently found to contribute most for metal removal in nanoenhanced bioremediation. However, the mechanism by which NPs affect EPS-metal interactions is not fully known. Here, Halomonas sp. was employed to explore the role of EPS after in vivo exposure to Cd/Pb and polyvinylpyrrolidone (PVP) coated iron oxide nanoparticles (IONPs, 20 mg L-1) for 72 h. Cd-IONPs produced the highest concentrations of EPS proteins (136.3 mg L-1), while Cd induced the most production of polysaccharides (241.0 mg L-1). IONPs increased protein/polysaccharides ratio from 0.2 (Cd) to 1.2 (Cd-IONPs). The increased protein favors the formation of protein coronas on IONPs surface, which would promote Cd adsorption during NP-metal-EPS interaction. FTIR analysis indicated that the coexistence of Cd and IONPs interacted with proteins more strongly than with polysaccharides. Glycosyl monomer analyses suggested mannose and glucose as target sugars for EPS complexation with metals, and IONPs reduced metal-induced changes in monosaccharide profiles. Protein secondary structures changed in all treatments, but we could not distinguish stresses induced by metals from those by IONPs. These findings provide greater understanding of the role of EPS in NP-metal-EPS interaction, providing a better underpinning knowledge for the application of NP-enhanced bioremediation.


Assuntos
Matriz Extracelular de Substâncias Poliméricas , Nanopartículas , Adsorção , Biodegradação Ambiental , Matriz Extracelular de Substâncias Poliméricas/química , Metais/análise
4.
MethodsX ; 8: 101550, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34754817

RESUMO

Metals being released into the environment are posing an increasing risk to both environments and public health. Developing improved approaches to remove these metals from the environment is urgent. A current publication discovered that metal bioremediation was significantly improved by nanoparticles (NPs), and the remediation duration was shortened. However, there is no relevant method for the preparation and evaluation of this novel idea. Hence, we developed this method for bacteria in-situ-EPS (Extracellular Polymeric Substances) cultivation, bacteria sub-cellular fractionation, and metal determinations in cultivating solution, EPS and different fractions of bacteria to evaluate metal removal by the combination of NPs and bacteria, including (1) the enhancement of metal bioremediation by NPs, (2) the influence of NPs on bacteria growth and metal toxicity alleviation, (3) the ability of EPS to adsorb metals and the influence of NPs on the EPS metal adsorption, (4) the contribution of bacteria to metal removal in different part, the effects of NPs on metal distribution patterns in bacteria, and the role of NPs in this process.•The design and experimental procedure for the evaluation of metal removal by combing bacteria and NPs.•In-situ EPS cultivation and separation in the study of bioremediation for metals.

5.
Nanotoxicology ; 15(8): 1005-1015, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34612156

RESUMO

Children are potentially exposed to products that contain nanoparticles (NPs). In particular, silver NPs are commonly present both in products used by and around children, primarily due to their antibacterial properties. However, very few data are available regarding the ability of silver NPs to penetrate through the oral mucosa in children. In the present work, we used baby porcine buccal mucosa mounted on vertical Franz diffusion cells, as an in vitro model to investigate penetration of silver NPs (19 ± 5 nm). Permeability experiments were performed using pristine physiologically-relevant saline solution in the receiver chamber and known concentrations of NPs or ions in the donor chamber; conditions mimicked the in vivo physiological pH conditions. After physicochemical characterization of silver nanoparticles dispersed in physiological solution, we evaluated the passage of ions and NPs through the mucosa, using single particle inductively coupled plasma mass spectrometry. A flux of 4.1 ± 1.7 ng cm-2 min-1 and a lag time of 159 ± 17 min were observed through mucosa exposed to silver nanoparticles. The latter suggests nanoparticle penetration through the baby porcine mucosa and release Ag+ ions in the receptor fluid, as confirmed by computational model. Due to physiological similarity between human and pig membranes it is reasonable to assume that a trans-oral mucosa penetration could occur in children upon contact with silver nanoparticles.


Assuntos
Nanopartículas Metálicas , Prata , Animais , Nanopartículas Metálicas/toxicidade , Mucosa , Tamanho da Partícula , Permeabilidade , Análise Espectral , Suínos
6.
Beilstein J Nanotechnol ; 12: 282-294, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33842185

RESUMO

Silver nanoparticles (AgNPs) are widely used in medical applications due to their antibacterial and antiviral properties. Despite the extensive study of AgNPs, their toxicity and their effect on human health is poorly understood, as a result of issues such as poor control of NP properties and lack of proper characterization. The aim of this study was to investigate the combined characterization, bio-uptake, and toxicity of well-characterized polyvinylpyrrolidone (PVP)-coated AgNPs in exposure media during exposure time using primary human cells (peripheral blood mononuclear cells (PBMCs)). AgNPs were synthesized in-house and characterized using a multimethod approach. Results indicated the transformation of NPs in RPMI medium with a change in size and polydispersity over 24 h of exposure due to dissolution and reprecipitation. No aggregation of NPs was observed in the RPMI medium over the exposure time (24 h). A dose-dependent relationship between PBMC uptake and Ag concentration was detected for both AgNP and AgNO3 treatment. There was approximately a two-fold increase in cellular Ag uptake in the AgNO3 vs the NP treatment. Cytotoxicity, using LDH and MTS assays and based on exposure concentrations was not significantly different when comparing NPs and Ag ions. Based on differential uptake, AgNPs were more toxic after normalizing toxicity to the amount of cellular Ag uptake. Our data highlights the importance of correct synthesis, characterization, and study of transformations to obtain a better understanding of NP uptake and toxicity. Statistical analysis indicated that there might be an individual variability in response to NPs, although more research is required.

7.
NanoImpact ; 21: 100283, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-35559775

RESUMO

Bacteria efficiently take up small organic molecules and ions. However, the internalization of particulate forms, specifically nanoparticles (NPs) has been understudied and is a newly-emerging area of interest. However, determination of true cellular internalization is challenging owing to the difficulty of separating the aqueous phase from bacteria-associated NPs and, more importantly, of differentiating between internalized and NPs sorbed on bacteria surfaces. In this work, we developed and validated an extraction method which can operationally estimate internalization of metal NPs into Gram-negative bacteria. The outer cell membrane and cell wall, collectively called the periplasm, was successfully removed from bacteria using ethylenediaminetetraacetic acid (EDTA) at an optimized exposure period and concentration, without lysis of bacteria. This was followed by standard digestion and metal measurements. Verification of each step of the methodology was conducted by assessing both cellular and metal behavior. Specifically, the combined approaches of live/dead staining of bacteria, optical density measurements, transmission electron microscopy (TEM) and metal analyses of the supernatant indicated that the method operationally separated externally-sorbed NPs from those internalized actually localized within the bacterial cytoplasm. However, this new method is ideally used alongside other methods in a multi-method approach, to provide improved data quality. Therefore, it should be used with CSLM, FACS, TEM and other available methods.


Assuntos
Antibacterianos , Nanopartículas Metálicas , Antibacterianos/uso terapêutico , Bactérias , Parede Celular , Bactérias Gram-Negativas , Nanopartículas Metálicas/uso terapêutico
8.
J Cancer Educ ; 36(6): 1193-1200, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-32314309

RESUMO

African-American (AA) women experience higher mortality from breast cancer than any other racial group. Understanding community-held perceptions of environmental contaminants as risk factors for breast cancer can inform the development of tailored prevention and education efforts for improve health outcomes. Six focus groups were conducted with AA participants in two counties in South Carolina, and themes were identified using open and axial coding. Perceived environmental risks for breast cancer most frequently discussed by participants were compared to findings from published systematic reviews. Frequently discussed environmental risk factors by participants were deodorants containing aluminum, plastics, pesticides, and air and water pollution. While perceptions of aluminum and air pollution as risk factors did not align with the state of the science, perceived risk factors of chemicals in plastics and pesticides were found to be in alignment. There is some congruence between perceived environmental risks for breast cancer within the AA community and the current state of the science; however, there is a need to communicate information that reflects current science regarding commonly held misconceptions. Development of evidence-based, clear, and culturally appropriate messaging that reflects the current state of the science is warranted.


Assuntos
Negro ou Afro-Americano , Neoplasias da Mama , Neoplasias da Mama/prevenção & controle , Feminino , Grupos Focais , Humanos , South Carolina
9.
Int Q Community Health Educ ; 41(3): 267-274, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32660340

RESUMO

African-American (AA) women are at higher risk of breast cancer mortality than women of other races. Factors influencing breast cancer risk, including exogenous environmental exposures, and debate around timing of exposure and dose-response relationship, can cause misunderstanding. Collaboration with priority populations encourages culturally relevant health messaging that imparts source reliability, influences message adoption, and improves understanding. Through six focus groups with AA individuals in rural and urban counties in the southeastern United States, this study used a community-engaged participatory approach to design an innovative visual tool for disseminating breast cancer information. Results demonstrated that participants were generally aware of environmental breast cancer risks and were willing to share new knowledge with families and community members. Recommended communication channels included pastors, healthcare providers, social media, and the Internet. Participants agreed that a collaboratively designed visual tool serves as a tangible, focused "conversation starter" to promote community prevention and education efforts.


Assuntos
Negro ou Afro-Americano , Neoplasias da Mama , Neoplasias da Mama/prevenção & controle , Comunicação , Feminino , Grupos Focais , Humanos , Reprodutibilidade dos Testes
10.
Environ Health Prev Med ; 25(1): 29, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32664857

RESUMO

Plastics are extensively used in our daily life. However, a significant amount of plastic waste is discharged to the environment directly or via improper reuse or recycling. Degradation of plastic waste generates micro- or nano-sized plastic particles that are defined as micro- or nanoplastics (MNPs). Microplastics (MPs) are plastic particles with a diameter less than 5 mm, while nanoplastics (NPs) range in diameter from 1 to 100 or 1000 nm. In the current review, we first briefly summarized the environmental contamination of MNPs and then discussed their health impacts based on existing MNP research. Our review indicates that MNPs can be detected in both marine and terrestrial ecosystems worldwide and be ingested and accumulated by animals along the food chain. Evidence has suggested the harmful health impacts of MNPs on marine and freshwater animals. Recent studies found MPs in human stool samples, suggesting that humans are exposed to MPs through food and/or drinking water. However, the effect of MNPs on human health is scarcely researched. In addition to the MNPs themselves, these tiny plastic particles can release plastic additives and/or adsorb other environmental chemicals, many of which have been shown to exhibit endocrine disrupting and other toxic effects. In summary, we conclude that more studies are necessary to provide a comprehensive understanding of MNP pollution hazards and also provide a basis for the subsequent pollution management and control.


Assuntos
Exposição Ambiental , Microplásticos/efeitos adversos , Poluentes da Água/efeitos adversos , Monitoramento Ambiental , Microplásticos/análise , Poluentes da Água/análise
11.
J Glob Antimicrob Resist ; 22: 811-817, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32653724

RESUMO

OBJECTIVES: The aim of this study was to examine how the concentrated delivery of less effective antibiotics, such as the ß-lactam penicillin G, by linkage to nanoparticles (NPs), could influence the killing efficiency against various pathogenic bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and other multidrug resistant (MDR) strains. METHODS: The ß-lactam antibiotic penicillin G (PenG) was passively sorbed to fluorescent polystyrene NPs (20nm) that were surface-functionalized with carboxylic acid (COO--NPs) or sulfate groups (SO4--NPs) to form a PenG-NP complex. Antimicrobial activities of PenG-NPs were evaluated against Gram-negative and Gram-positive bacteria, including antibiotic resistant strains. Disc diffusion, microdilution assays and live/dead staining were performed for antibacterial assessments. RESULTS: The results showed that bactericidal activities of PenG-NP complexes were statistically significantly (P<0.05) enhanced against Gram-negative and Gram-positive strains, including MRSA and MDR strains. Fluorescence imaging verified that NPs comigrated with antibiotics throughout clear zones of MIC agar plate assays. The increased bactericidal abilities of NP-linked antibiotics are hypothesized to result from the greatly increased densities of antibiotic delivered by each NP to a given bacterial cell (compared with solution concentrations of antibiotic), which overwhelms the bacterial resistance mechanism(s). CONCLUSIONS: As a whole, PenG-NP complexation demonstrated a remarkable activity against different pathogenic bacteria, including MRSA and MDR strains. We term this the 'grenade hypothesis'. Further testing and development of this approach will provide validation of its potential usefulness for controlling antibiotic-resistant bacterial infections.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Nanopartículas , Antibacterianos/farmacologia , Sistemas de Liberação de Medicamentos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana
12.
RSC Adv ; 10(6): 3266-3276, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-35497719

RESUMO

Water pollution is a major global challenge given the increasing growth in industry and human population, and certain metals can be highly toxic and contribute to this significantly. In this study, polyvinylpyrrolidone-coated magnetic nanoparticles (PVP-Fe3O4 NPs) were used to remove metals (Cd, Cr, Ni, and Pb) from synthetic soft water and sea water in the presence and absence of fulvic acid. Nanoparticle (NP) suspensions were added to water media at a range of metal concentrations (0.1-100 mg L-1). Removal at different time points (1.5, 3, 6, 12, 24 hours) was also evaluated. Results showed that 167 mg L-1 PVP-Fe3O4 NPs could remove nearly 100% of four metals at 0.1 mg L-1 and more than 80% at 1 mg L-1. The removal decreased as the initial metal concentration increased, although essentially 100% of the Pb was removed under all conditions. The kinetic adsorption fitted well to the pseudo-second-order model and in general, the majority of metal adsorption occurred within the first 1.5 hours. These NPs are a reliable method to remove metals under a wide range of environmentally relevant conditions. Our previous research showed the NPs effectively removed oil from waters, so these NPs offer the possibility of combined in situ remediation of oil and metals.

13.
Sci Total Environ ; 704: 135378, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31806322

RESUMO

Polyvinylpyrrolidone (PVP) coated iron oxide nanoparticles (NPs) were used to explore the potential for improved bioremediation of metals by interaction with the Gram-negative bacterium Halomonas sp. The combined approach improved metal removal and shortened metal remediation times (approx. 100% removal of Pb after 24 h, of Cd after 48 h) compared with bacteria- or NP-only controls. NPs also demonstrated the ability to reduce metal toxicity to bacteria and enhance bacterial growth efficiencies in an additive manner. Cd, Pb, and Fe (from NPs) were analyzed in the following operationally-defined components: EPS, cell-wall, cell membrane, and cytoplasmic fractions; EPS was most important in metal removal. There was a significant promotion of Cd intracellular transportation, but not Pb, by NPs. Reduced Pb internalization may have resulted from EPS acting as an uptake barrier coupled with an effective efflux system of Halomonas sp. as a resistance mechanism. In addition, the majority of Fe was present in bacterial membranes, compared with Cd or Pb, suggesting that bacteria may take up iron oxide NPs as a potential nutrient while recognizing Cd or Pb as toxicants.


Assuntos
Recuperação e Remediação Ambiental/métodos , Metais , Poluentes do Solo , Bactérias , Biodegradação Ambiental , Nanotecnologia
14.
Sci Total Environ ; 707: 135528, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-31780146

RESUMO

BACKGROUND: This pilot study was conducted to determine if we could identify intrauterine exposure to metals in meconium, as a measure of exposure for mother-child pairs living in proximity to a mining operation. OBJECTIVES: We used meconium as a means to measure metal exposure in utero. We set out to quantify the exposure to selected metals that are currently being mined and also are found in the Superfund site in Butte, Montana, and to compare it to that of Columbia, South Carolina, US, where mining is not occurring. METHODS: This cross-sectional study was conducted between May and November 2018. We received Institutional Review Board approval and we consented women following the birth of their newborns, and collected meconium within 24 h of birth, without any identifiers. Each laboratory used the same protocol for collection, transport, and storage; and the same laboratory protocol was used for the analysis of all samples. Samples were digested using standard acid/peroxide digestion methods and measured by inductively coupled plasma mass spectroscopy. RESULTS: We collected meconium specimens from 17 infants in Columbia, South Carolina and 15 infants in Butte, Montana. The concentrations found in Columbia were in the low µg kg-1 range (or less) and were similar to the low levels that have been identified in other studies of meconium. The magnitude of the differences in concentrations found in Butte compared to Columbia was 1792 times higher for Cu, 1650 times higher for Mn, and 1883 times higher for Zn. CONCLUSION: Using meconium to measure exposure of newborns has implications for risk assessment in a mining-exposed population. This approach was inexpensive and thorough. The magnitude of the differences in the metal levels identified from the two study sites suggests there is an urgent need for further research to learn if there are health consequences to these highly exposed infants.


Assuntos
Mecônio , Estudos Transversais , Feminino , Humanos , Recém-Nascido , Metais , Montana , Projetos Piloto , South Carolina
15.
Nanotoxicology ; 13(9): 1149-1160, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31284796

RESUMO

Core-shell silver nanoparticles (NPs) consisting of an inner Ag core and successive layers of Au and Ag (Ag@Au@Ag) were used to measure the simultaneous association of Ag NPs and ionic Ag by the green alga Chlamydomonas (C.) reinhardtii. Dissolution of the inner Ag core was prevented by a gold (Au) layer, while the outer Ag layer was free to dissolve. In short-term experiments, we exposed C. reinhardtii to a range of environmentally realistic Ag concentrations added as AgNO3 or as NPs. Results provide three lines of evidence for the greater cell-association of NPs compared to dissolved Ag over the concentration range tested, assuming that cell-association comprises both uptake and adsorption. First, the cell-association rate constants (kuw) for total Ag (AgNP+D), NPs (AgNP) and AuNP were similar and 2.2-fold higher than the one from AgD exposure, suggesting predominant association of the particles over the dissolved form. Second, model calculations based on Ag fluxes suggested that only 6-33% of algal burden was from AgD. Third, the significantly lower AgNP/Au ratio measured with the algae after exposure (2.1 ± 0.1) compared to the AgNP/Au ratio of the NPs in the media (2.47 ± 0.05) suggests cell-association of NPs depleted in Ag. Core-shell NPs provide an innovative tool to understand NP behavior and to directly delineate Ag accumulation from ion and NPs in aquatic systems.


Assuntos
Chlamydomonas reinhardtii/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Ouro/química , Nanopartículas Metálicas/química , Prata/química , Solubilidade
16.
Appl Microbiol Biotechnol ; 103(11): 4623-4632, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30997552

RESUMO

Recent studies from our laboratory indicate that engineered silver nanoparticles can inhibit aflatoxin biosynthesis even at concentrations at which they do not demonstrate antifungal activities on the aflatoxin-producing fungus. Whether such inhibition can be modified by altering the nanoparticles' physical properties remains unclear. In this study, we demonstrate that three differently sized citrated-coated silver nanoparticles denoted here as NP1, NP2, and NP3 (where, sizes of NP1 < NP2 < NP3) inhibit aflatoxin biosynthesis at different effective doses in Aspergillus parasiticus, the plant pathogenic filamentous fungus. Recapping NP2 with polyvinylpyrrolidone coating (denoted here as NP2p) also altered its ability to inhibit aflatoxin production. Dose-response experiments with NP concentrations ranging from 10 to 100 ng mL-1 indicated a non-monotonic relationship between aflatoxin inhibition and NP concentration. The maximum inhibitory concentrations differed between the NP types. NP1 demonstrated maximum inhibition at 25 ng mL-1. Both NP2 and NP3 showed maximum inhibition at 50 ng mL-1, although NP2 resulted in a significantly higher inhibition than NP3. While both NP2 and NP2p demonstrated greater aflatoxin inhibition than NP1 and NP3, NP2p inhibited aflatoxin over a significantly wider concentration range as compared to NP2. Our results, therefore, suggest that nano-fungal interactions can be regulated by altering certain NP physical properties. This concept can be used to design NPs for mycotoxin prevention optimally.


Assuntos
Aflatoxinas/antagonistas & inibidores , Aflatoxinas/biossíntese , Antifúngicos/metabolismo , Aspergillus/efeitos dos fármacos , Metabolismo/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/metabolismo , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Nanopartículas Metálicas/ultraestrutura , Venenos
17.
Environ Sci Technol ; 53(8): 4426-4432, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30888155

RESUMO

Oil spills can have dramatic impacts on the environment. The limitations of current oil remediation techniques have inspired researchers to study the application of nanotechnology for oil cleanup. Previously, we reported essentially 100% removal of a reference MC252 oil using polyvinylpyrrolidone (PVP)-coated iron oxide nanoparticles (NPs) from oil-water mixtures under a wide range of environmentally relevant conditions. Our previous results showed that in the synthetic water samples, the concentration of cations and natural organic macromolecules (NOM) can significantly affect the oil removal efficiency of NPs. Here, we studied the application of these NPs for oil removal from natural freshwater samples and compared the results with the synthetic water samples with the same concentrations of major ions and NOM. For both natural and synthetic samples, concentrations of NOM, calcium, and magnesium were positively correlated with oil removal ( p-value <0.05). NPs show an average of 30% higher oil removal efficiency from natural samples compared to the synthetic samples. Using up to 50 ppm of NP, essentially 100% oil removal was observed under most conditions specially hardwater samples (initial 0.15 g L-1 oil concentration). Results show that these NPs are a facile and reliable technique for removing oil under realistic conditions.


Assuntos
Nanopartículas de Magnetita , Nanopartículas , Poluentes Químicos da Água , Polímeros , Povidona
18.
Environ Int ; 121(Pt 1): 111-118, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30195624

RESUMO

Among women living in the United States, breast cancer is the second leading cause of cancer death. Disproportionate racial disparities in breast cancer exist, with African American (AA) women consistently having the highest rates of breast cancer related mortality despite lower incidence. This study attends to the Institute of Medicine's (IOM) call to action recommending the identification of effective strategies for communicating accurate and reliable breast cancer risk information to diverse audiences. Using focus group methodology, this study explores how AAs perceive and decipher information related to breast cancer and its relationship to their environment. Six focus groups were conducted. The sample (n = 50) was African American, 98% female, with an average age of 50.1 years. The focus group protocol consisted of open-ended questions designed to elicit information about participants' perceptions of their environment and its link to breast cancer. Focus groups were audio recorded and professionally transcribed. Analysis of the focus group transcripts revealed themes pertaining to these categories: (1) general knowledge and beliefs about breast cancer, (2) perceived environmental risks factors for breast cancer, (3) importance of seeking knowledge about breast cancer and the environment, and (4) recommended communication strategies. The emergent themes reflect the knowledge participants possessed about breast cancer and environmental risk factors, in addition to concerns about the importance of possessing accurate information, and how culturally appropriate health communication strategies can be used to disseminate breast cancer knowledge in the community. Findings from this study can be used for culturally appropriate communication about breast cancer and the environment with AA communities.


Assuntos
Negro ou Afro-Americano/psicologia , Neoplasias da Mama/psicologia , Comunicação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Percepção , Adulto , Idoso , Idoso de 80 Anos ou mais , Meio Ambiente , Feminino , Grupos Focais , Humanos , Masculino , Pessoa de Meia-Idade , Risco , Sudeste dos Estados Unidos , Adulto Jovem
19.
Am J Health Educ ; 49(4): 222-233, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30079123

RESUMO

BACKGROUND: Effective online communication about the environmental risk factors of breast cancer is essential because of the multitude of environmental exposures and debate regarding the conclusiveness of scientific evidence. PURPOSE: The aim of this study was to assess the content, readability, and cultural sensitivity of online resources focused on the environmental risks factors of breast cancer. METHODS: A purposive sample of webpages focused on environmental risk factors of breast cancer was obtained through a Google search using 17 search terms. Using nonparametric statistics, we assessed the content, readability, and cultural appropriateness of 235 webpages. RESULTS: Eighty-two percent of webpages referred to research studies in their content. For the majority of sites, readability was at a high-school reading grade level. Webpages were not explicitly intended for specific racial/ethnic groups. DISCUSSION: Technical language and non-culturally specific messages may hinder users' attention to and comprehension of online breast cancer information. Additional research is needed to examine in-depth the accuracy of this online content. TRANSLATION TO HEALTH EDUCATION PRACTICE: Findings suggest that collaborations between scientists, health educators, website designers/media professionals, and the community will be critical to the delivery of accurate, up-to-date, plain-language, and culturally sensitive information about breast cancer and the environment.

20.
J Environ Prot (Irvine, Calif) ; 9(4): 385-404, 2018 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-29910967

RESUMO

Nanotechnology has significant economic, health, and environmental benefits, including renewable energy and innovative environmental solutions. Manufactured nanoparticles have been incorporated into new materials and products because of their novel or enhanced properties. These very same properties also have prompted concerns about the potential environmental and human health hazard and risk posed by the manufactured nanomaterials. Appropriate risk management responses require the development of models capable of predicting the environmental and human health effects of the nanomaterials. Development of predictive models has been hampered by a lack of information concerning the environmental fate, behavior and effects of manufactured nanoparticles. The United Kingdom (UK) Environmental Nanoscience Initiative and the United States (US) Environmental Protection Agency have developed an international research program to enhance the knowledgebase and develop risk-predicting models for manufactured nanoparticles. Here we report selected highlights of the program as it sought to maximize the complementary strengths of the transatlantic scientific communities by funding three integrated US-UK consortia to investigate the transformation of these nanoparticles in terrestrial, aquatic, and atmospheric environment. Research results demonstrate there is a functional relationship between the physicochemical properties of environmentally transformed nanomaterials and their effects and that this relationship is amenable to modeling. In addition, the joint transatlantic program has allowed the leveraging of additional funding, promoting transboundary scientific collaboration.

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