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1.
J Colloid Interface Sci ; 559: 197-205, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31627143

RESUMO

Mesoporous silica nanoparticle (MSN) demonstrates great potentials as a loading platform for bactericidal agents, but may be limited by its application form of bulk or powder. Herein, we developed MSN surface-enriched composite membranes with remarkable photodynamic antimicrobial activities via a facile electrospinning method. The mixture of zein and polycaprolactone (PCL) was served as the polymeric matrix, while the methylene blue (MB) loaded MSN was modified by trichloro (1H, 1H, 2H, 2H-heptadecafluorodecyl) silane (THFS) and acted as reactive oxygen species (ROS) generator to exert their antimicrobial performances. Owing to its low surface energy, the fluorinated MSN tended to be enriched on the surface of the nanofiber, hence significantly enhancing the ROS generation. Moreover, benefiting from the surface enrichment of the fluorinated nanoparticles, the composite membrane displayed obvious surface hydrophobicity and exhibited discernible bacterial repellency. Subsequently, upon visible light (660 nm) irradiation, the composite membrane demonstrated remarkable photodynamic antibacterial activities against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) but without essential detrimental impacts on the mammalian cells. We envision that this self-enriched MSN composite membrane may find broad applications in bacterial infection-resistant areas.


Assuntos
Anti-Infecciosos/química , Azul de Metileno/química , Nanopartículas/química , Fotoquimioterapia/métodos , Dióxido de Silício/química , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Fibroblastos/citologia , Flúor/química , Interações Hidrofóbicas e Hidrofílicas , Luz , Camundongos , Poliésteres/química , Porosidade , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Zeína/química
2.
J Environ Sci (China) ; 87: 39-48, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31791512

RESUMO

Carbon-silica materials with hierarchical pores consisting of micropores and mesopores were prepared by introducing nanocarbon microspheres derived from biomass sugar into silica gel channels in a hydrothermal environment. The physicochemical properties of the materials were characterized by nitrogen physical adsorption (BET), scanning electron microscopy (SEM), and thermogravimetric (TG), and the adsorption properties of various organic waste gases were investigated. The results showed that microporous carbon materials were introduced successfully into the silica gel channels, thus showing the high adsorption capacity of activated carbon in high humidity organic waste gas, and the high stability and mechanical strength of the silica gel. The dynamic adsorption behavior confirmed that the carbon-silica material had excellent adsorption capacity for different volatile organic compounds (VOCs). Furthermore, the carbon-silica material exhibited excellent desorption characteristics: adsorbed toluene was completely desorbed at 150°C, thereby showing superior regeneration characteristics. Both features were attributed to the formation of hierarchical pores.


Assuntos
Modelos Químicos , Compostos Orgânicos Voláteis/química , Adsorção , Biomassa , Carvão Vegetal , Umidade , Interações Hidrofóbicas e Hidrofílicas , Microesferas , Porosidade , Dióxido de Silício/química , Tolueno/química
3.
J Colloid Interface Sci ; 558: 137-144, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31586733

RESUMO

Platinum oxide (PtOx) nanoparticles (NPs) have been shown to possess anticancer activity by releasing ionic Pt species under biological conditions. However, the dissolution kinetics and the changes in the chemical state of Pt during PtOx dissolution have not yet been studied. To fill this gap, we prepared a composite (designated as PtOx@MMT-2) containing PtOx NPs on hollow mesoporous silica nanospheres and studied the dissolution of the material in different biorelevant media. We found that the release of Pt was retarded due to the adsorption of biomolecules on PtOx NPs during the degradation of host silica. The biomolecules adsorption also lowered the accessibility of PtOx NPs, resulting in the reduced catalase-like activity of the NPs. In line with the results, the cytotoxicity of PtOx@MMT-2, which was positively correlated to the amount of Pt uptake, was reduced by biomolecules adsorption. Our findings should be applicable to other metal (oxide) NPs under biological conditions and may provide implications for the design of nanomaterials for practical therapeutic applications.


Assuntos
Materiais Biocompatíveis/química , Nanopartículas/química , Óxidos/química , Platina/química , Dióxido de Silício/química , Adsorção , Materiais Biocompatíveis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células HeLa , Humanos , Nanopartículas/uso terapêutico , Solubilidade
4.
J Environ Manage ; 254: 109787, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31710978

RESUMO

As an emerging class of silica-based mesoporous materials with incorporation of active components (e.g., transition metals/metal oxides and nanocarbons), SBA-15-based composites (X@SBA-15) have been attracting increasing attention in the field of water treatment owing to their unique characteristics and excellent remediation performance. This paper reviews recent advances in catalytic applications of X@SBA-15 to remove organic contaminants from water. Emphasis is made on the use of X@SBA-15 in four advanced oxidation processes (AOPs) (i.e., photocatalysis, Fenton-like oxidation, catalytic ozonation, and sulfate radical-based oxidation). Impregnation and hydrothermal methods are two most widely used synthetic approaches to combine the active composites with SBA-15, obtaining a synergistic effect with significant improvement in their individual catalytic activity for pollution remediation. The enhanced generation of highly reactive hydroxyl radicals from the surface of X@SBA-15 was widely recognized as being responsible for water decontamination using these AOPs, while sulfate radicals were also involved during activation of persulfate or peroxymonosulfate. Especially, X@SBA-15 could significantly enhance the light harvest and reduce the recombination of photo-induced electrons and holes during photocatalytic treatment, which also played the critical role in oxidizing the organics. The superior catalytic performance of X@SBA-15 without leaching metal ions during successive runs demonstrated the excellent reusability and structural stability. Together with the reduced toxicity of the treated solutions and the cost-effective characteristics of X@SBA-15 nanohybrids reported in the published literature, their great potential as the efficient and environmentally friendly heterogeneous catalysts in a real use scenario is suggested. Finally, the future perspectives on the development and practical utilization of X@SBA-15 are addressed.


Assuntos
Poluentes Químicos da Água , Água , Descontaminação , Dióxido de Silício
5.
J Environ Manage ; 254: 109785, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31733484

RESUMO

It is important to understand the migration of Cesium (Cs) in soils, particularly after the nuclear power plant accident at Fukushima Dai-ichi, Japan. Dissolved organic matter (DOM) is one of factors affecting the migration of Cs in soils under flowing water conditions. We investigated the effect of DOM on the migration of Cs adsorbed to the clay planar site via laboratory column experiments. The sequence of DOM application had a significant influence on Cs transport in the soil. When DOM was applied concurrently with or prior to Cs application, the DOM adsorbed on to the clay planar site adsorbed onto the soil solid surface and enhanced Cs adsorption; consequently, it slowed Cs migration in the soil. In particular, in the case of DOM loaded prior to the application of Cs solution, a noticeable delay in Cs migration was observed. On the other hand, when DOM was applied to the soil where the Cs solution had been previously applied, the DOM desorbed Cs from the soil. DOM in liquid phase enhanced the migration of Cs through the formation of binding to organic matter. Majority of Cs affected by DOM was the exchangeable fraction that adsorbed to the clay planar site. In other words, DOM attached to the soil would adsorb Cs as a easily exchangeable form and depress migration of Cs. On the other hand, DOM in the soil solution may up take adsorbed Cs from the soil and enhanced the transport in the form of Cs bound to DOM.


Assuntos
Acidente Nuclear de Fukushima , Monitoramento de Radiação , Poluentes Radioativos do Solo , Césio , Radioisótopos de Césio , Japão , Dióxido de Silício , Solo
6.
Chemosphere ; 240: 124937, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31574441

RESUMO

Nowadays, silica nanoparticles (SiNPs) as one of the most productive nano-powder, has been extensively applied in various filed. The potential harm of SiNPs has previously received severe attention. A bulk of researches have proven the adverse effect of SiNPs on the health of ecological organisms and human. However, neurotoxic impacts of SiNPs, still remain in the stage of exploration. The potential neurotoxic effects of SiNPs need to be further explored. And the toxic mechanism needs comprehensive clarification. Herein, the neurotoxicity of SiNPs of various concentrations (100, 300, 1000 µg/mL) on adult zebrafish was determined by behavioral phenotyping and confirmed by molecular biology techniques such as qPCR. Behavioral phenotype revealed observable effects of SiNPs on disturbing light/dark preference, dampening exploratory behavior, inhibiting memory capability. Furthermore, the relationship between neurotoxic symptom and the transcriptional alteration of autophagy- and parkinsonism-related genes was preliminarily assessed. Importantly, further investigations should be carried out to determine the effects of SiNPs to cause neurodegeneration in the brain as well as to decipher the specific neurotoxic mechanisms. In sum, this work comprehensively evaluated the neurotoxic effect of small-sized SiNPs on overall neurobehavioral profiles and indicated the potential for SiNPs to cause Parkinson's disease, which will provide a solid reference for the research on the neurotoxicity of SiNPs.


Assuntos
Comportamento Animal/efeitos dos fármacos , Síndromes Neurotóxicas/patologia , Dióxido de Silício/toxicidade , Peixe-Zebra/fisiologia , Animais , Autofagia/efeitos dos fármacos , Autofagia/genética , Humanos , Nanopartículas/toxicidade , Peixe-Zebra/genética
7.
Water Res ; 168: 115179, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31639593

RESUMO

The transport of per- and poly-fluoroalkyl substances (PFAS) in the vadose zone is complicated by the fact that multiple mass-transfer processes can contribute to their retention and retardation. In addition, PFAS transport at some sites can be further complicated by the presence of organic immiscible liquids (OIL). Mass-transfer processes are inherently rate limited and, therefore, have the potential to cause nonideal transport of PFAS. The objectives of this research were to: (1) develop a solute-transport model that explicitly accounts for multiple retention processes, including adsorption at air-water and OIL-water interfaces, adsorption by the solid phase, and diffusive mass-transfer between advective and nonadvective domains, and (2) apply the model to measured transport data to delineate which processes are rate limited and contribute to observed nonideal transport. Breakthrough curves for transport of two PFAS and one hydrocarbon surfactant in sand obtained from prior miscible-displacement experiments exhibited nonideal transport. The multiprocess model effectively simulated the measured transport data. The results of the analyses indicate that adsorption at the air-water and OIL-water interface can generally be treated as effectively instantaneous for transport in porous media. The rate limitations associated with solid-phase adsorption and diffusive mass transfer between advective and nonadvective domains were of greater significance.


Assuntos
Fluorcarbonetos , Adsorção , Porosidade , Dióxido de Silício , Água
8.
J Biomed Nanotechnol ; 15(11): 2240-2250, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31847938

RESUMO

Therapeutic efficacy of solid tumor is often severely hampered by poor penetration of therapeutics into diseased tissues and lack of tumor targeting. In this study, the functionalized upconversion nanoparticles (UCNP)-based delivery vector targeting cancer cells was developed. Firstly, NaYF4:Yb/Tm (UCNP) was prepared with the solvothermal method for the uniform nanoparticle size and brilliant lattice structure. The SiO2 coated UCNP was demonstrated a high upconversion emission and good monodispersity, which was coupled with polyetherimide (PEI) and miR-145 vector. Then, it was further functionalized via hyaluronic acid (HA) (UCNP/PEI/HA Nanocomplex, UCNPs) coating for the targeted delivery and improved biocompatibility. The UCNPs/miR-145 displays an excellent biocompatibility, a high level of cellular uptake and miR-145 expression, which results in a significant cell cycle arrest in G1, and induces CCND1, CDK6 and CCNE2 proteins downregulation. In vivo, the HA-coated UCNPs were enriched at the tumor site by targeting and retention effects, which resulted in a significant inhibition of tumor growth. Histological experiments demonstrated that UCNPs did not show significant toxicity in mice colon cancer model. Taken together, a UCNPs-based delivery platform was successfully constructed and used for miRNA target delivery, which provided a new method and idea for bioengineering and nanotechnology-based tumor therapy.


Assuntos
Neoplasias do Colo , Nanopartículas , Animais , Camundongos , MicroRNAs , Nanotecnologia , Dióxido de Silício
9.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 44(10): 1089-1098, 2019 Oct 28.
Artigo em Chinês | MEDLINE | ID: mdl-31857501

RESUMO

OBJECTIVE: To analyze the differential expression of RAW264.7 macrophage-derived exosomes miRNA stimulated by free silicon dioxide (SiO2).
 Methods: RAW264.7 was stimulated with SiO2 (200 mg/L) for 48 h (exo_48 h group), and the supernatant was collected. The exosomes in the supernatant were extracted by ultracentrifugation. Transmission microscopy, nanoparticle tracking analysis (NTA) and Western blotting were used to identify exosomes. High-throughput sequencing was performed to compare the differential expression of exosome miRNAs between the exo_control group (RAW264.7 cultured for 48 h without SiO2) and the exo_48 h group; miRanda, TargetScan and starBase were used to predict target genes of differential miRNAs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed on target genes to further analyze the biological functions of genes.
 Results: The transmission microscopy showed that the exosomes were lipid membrane coated vesicles, which were heterogeneously distributed, with a diameter ranging from 30 to 100 nm, and the shape was round or elliptical. The volume kurtosis was concentrated between 40 and 100 nm and the exosome marker protein TSG101 was positive. High-throughput sequencing screened 148 differentially expressed exosomal miRNAs. MiR-219c-3p, let-7d-3p, let-7a-1-3p, miR-328-3p, miR-365-3p, and miR-7219-3p were significantly up-regulated, and miR-378d and miR-5106 were significantly down-regulated compared with the control group. Target genes were mainly enriched in mTOR signaling pathway, Wnt signaling pathway, TGF-ß signaling pathway, and so on.
 Conclusion: The exosomes secreted by SiO2-induced macrophages contain abundant miRNAs, and their expressions are significantly different. These differential miRNAs may be involved in the activation of lung fibroblasts and epithelial-mesenchymal transition.


Assuntos
Exossomos , Macrófagos , Animais , Linhagem Celular , Sequenciamento de Nucleotídeos em Larga Escala , Camundongos , MicroRNAs , Dióxido de Silício
10.
Nihon Shokakibyo Gakkai Zasshi ; 116(11): 944-951, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31708507

RESUMO

This case report presents two males with drug-induced liver injury acquired from working at a glass factory dealing with silica and 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123). Within one month of work, both patients presented with fever, icterus with liver dysfunction, and eosinophilia. Case 1 had experienced recurrence of symptoms twice while working and showed positive results for the drug-induced lymphocyte stimulation test (DLST). Meanwhile, case 2 was diagnosed by liver biopsy and clinical course but was negative for DLST. Hazard of exposure to non-crystalline silica is low, but drug-induced liver injury after exposure to HCFC-123 has been reported. Allergic liver injury is also caused by chemical substances;however, the insight into whether this injury is caused by exposure to silica or HCFC-123 remains unclear. Further studies are required to examine the influence of silica and HCFC-123 on drug-induced liver injury among glass-factory employees.


Assuntos
Poluentes Ocupacionais do Ar/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Etano Clorofluorcarbonos/toxicidade , Clorofluorcarbonetos , Dióxido de Silício/toxicidade , Humanos , Masculino , Exposição Ocupacional
11.
J Biomed Nanotechnol ; 15(12): 2363-2375, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31748017

RESUMO

Breast cancer tends to spread to other organs and bone metastasis has the highest frequency in breast cancer metastasis, while its mechanisms are not clear and the current treatments are not very effective. To better study the mechanisms and facilitate drug screening for breast cancer bone metastasis, an in vivo mouse model needs to be constructed. However, the construction of the humanized mouse model for cancer bone metastasis which will mimick real interactions between cancer tissue and bone tissue in the human microenvironment remains a challenge. In this study, we constructed a human engineering bone tissue composed with the human osteoblast-like cells (SaOS-2 cells) and the silica nanoparticlesincorporated human demineralized bone matrix (Si/DBM). The engineered bone was then transplanted into a nude mouse to build a humanized bone microenvironment. The human breast cancer cells were then injected into the fat pads of the nude mouse to form an orthotopic tumor. The results showed that the engineered bone tissue-constructed humanized bone microenvironment had significant advantages when inducing human cancer cells to metastasize into the engineered bone tissue. Further, the SaOS-2/Si/DBM had a stronger ability to entice cancer-bone metastasis through promoting osteogenesis compared to the SaOS-2/DBM. Accordingly, this study highlights a novel, facile and effective mouse model for human cancer-bone metastasis, which will provide a platform to explore the mechanisms and anti-tumor drug screening for cancer-bone metastasis.


Assuntos
Neoplasias Ósseas , Nanopartículas , Animais , Matriz Óssea , Humanos , Camundongos , Dióxido de Silício , Engenharia Tecidual , Microambiente Tumoral
12.
J Biomed Nanotechnol ; 15(12): 2428-2438, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31748022

RESUMO

Limited understanding of mitochondria disorders that induced by nanoparticles is a stumbling block for anti-cancer drug delivery targeting strategy. In present study, C6 glioma cells were exposed to aminated and alkylated SiO2 nanoparticles for mitochondrion disordering and cell metabolism study. Collective results showed that aminated nanoparticles tend to trigger the cell-repair mechanism in cancer cells while alkylated nanoparticles could cause irreversible damages on cancer cells, although both types of the particles were proved to damage mitochondrion. The underlying mechanism show that aminated nanoparticles induced proton-stuck effect in mitochondrion and self-repairing in cancer cells by up-regulating p21. Otherwise, alkylated nanoparticles damaged mitochondrion and induced phosphorylated cyclin E accumulation lead to Fbw7 down-regulation caused further S phase arrest and severe late apoptosis. This work can help us elucidate the mechanism of the clinic application of nano-drug carriers.


Assuntos
Nanopartículas , Apoptose , Cátions , Linhagem Celular Tumoral , Humanos , Mitocôndrias , Dióxido de Silício
13.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi ; 37(10): 781-784, 2019 Oct 20.
Artigo em Chinês | MEDLINE | ID: mdl-31726512

RESUMO

Objective: To discuss the difference between pyrophosphoric acid method and infrared spectrophotometry for the determination of silica content in dust. Methods: The content of silica in the laboratory comparison samples organized by CDC Occupational Health Institute in China in 2018, and purchased quality control samples were determined by pyrophosphate method. Meanwhile, the samples were qualitatively and quantitatively analyzed by infrared spectrophotometry, and the results obtained by the two methods were compared. Results: Four samples (062C1、062C2、GDOHZKTG012-1、GDOHZKTG012-2) were detected by pyrophosphate method and infrared spectrophotometry. The results of pyrophosphate method were 55.49%, 5.24%, 4.90% and 54.72%, respectively. The results of infrared spectrophotometry were 0.91%, 1.87%, 1.29% and 1.16% respectively. Conclusion: The content of silica in dust determined by pyrophosphate method is higher than that by infrared spectrophotometry.


Assuntos
Poluentes Ocupacionais do Ar/análise , Difosfatos , Poeira/análise , Dióxido de Silício/análise , Espectrofotometria Infravermelho , China
15.
Environ Sci Technol ; 53(22): 13302-13311, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31621307

RESUMO

Composite magnetic aluminum hydroxide at iron oxide nanomaterials, Al(OH)3@Fe3O4, with a well-defined core-shell structure, were used as pretreatment adsorbents for the removal of silica in brackish water. The Al(OH)3 outer shell confers silica adsorption capacity, and the superparamagnetic Fe3O4 core allows material separation and magnetic recovery. The as-prepared nanomaterials (2 g L-1) remove ∼95 and ∼80% silica from Si-rich solutions with 0.5 and 2 mM initial silica concentrations, respectively. Regeneration under basic conditions was evaluated, and post-adsorption treatment with 0.05 M NaOH yielded optimal material reusability. After four regeneration cycles, the Al(OH)3@Fe3O4 nanomaterials retain their magnetic property while still being able to remove ∼40% silica from solutions at an adsorbent concentration of 2 g L-1. The mechanism of silica adsorption onto the surface of the nanomaterials was probed using several spectroscopic techniques. ATR-FTIR (attenuated total reflection-Fourier transform infrared) integrated with two-dimensional correlation analysis shows that silica species vary from Q2 to Q4 with adsorption time corresponding to silica polymerization. 29Si solid-state NMR spectra show an upfield chemical shift displacement of the Q2 signal, which indicates the formation of Q4 units, suggesting silica polymerization onto the Al(OH)3 shell. In addition, a laboratory-scale reverse osmosis setup was used to evaluate Al(OH)3@Fe3O4 as pretreatment materials for silica removal. Results show that silica scaling was significantly alleviated, and water recovery was enhanced when feed waters were pretreated with the magnetic nanomaterials. Taken together, our study highlights the promise of magnetic Al(OH)3@Fe3O4 nanomaterials in treating brackish water and achieving higher water recovery for inland desalination.


Assuntos
Dióxido de Silício , Poluentes Químicos da Água , Adsorção , Alumínio , Ferro , Osmose
16.
Environ Sci Technol ; 53(21): 12706-12714, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31593449

RESUMO

Viral contamination of drinking water due to fecal contamination is difficult to detect and treat effectively, leading to frequent outbreaks worldwide. The purpose of this paper is to report on the molecular mechanism for unprecedented high virus removal from a practical sand filter. Sand filters functionalized using a water extract of Moringa oleifera (MO) seeds, functionalized sand (f-sand) filters, achieved a ∼7 log10 virus removal. These tests were conducted with MS2 bacteriophage, a recognized surrogate for pathogenic norovirus and rotavirus. We studied the molecular mechanism of this high removal since it can have important implications for sand filtration, the most common water treatment technology worldwide. Our data reveal that the virus removal activity of f-sand is due to the presence of a chitin-binding protein, M. oleifera chitin-binding protein (MoCBP) on f-sand. Standard column experiments were supported by proteomic analysis and molecular docking simulations. Our simulations show that MoCBP binds preferentially to MS2 capsid proteins demonstrating that specific molecular interactions are responsible for enhanced virus removal. In addition, we simplified the process of making f-sand and evinced how it could be regenerated using saline water. At present, no definitive solution exists for the challenge of treating fecally contaminated drinking and irrigation water for viruses without using technologies that demand high energy or chemical consumption. We propose functionalized sand (f-sand) filters as a highly effective, energy-efficient, and practical technology for virus removal applicable to both developing and developed countries.


Assuntos
Proteômica , Purificação da Água , Filtração , Levivirus , Simulação de Acoplamento Molecular , Dióxido de Silício
17.
J Cosmet Sci ; 70(5): 259-270, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31596228

RESUMO

The aim of the study was to investigate skin microcirculation, flux, and temperature changes induced by the application of Dead Sea mud (DSM) formulas with different mud salts and mineral contents using laser Doppler flowmetry. Instrumental analysis of eight over-the-shelf DSM products and four different samples of nonformulated Dead Sea mud were carried out to determine their contents of various salts and elements, including K, Na, Cl, Mg, Mn, Ca, SO3, SiO2, Al, Br, Fe, Hg, Cr, Co, Ni, Cu, Zn, As, Cd, Pb, and Sr. Three DSM samples with different levels of salts were then used to study the influence of salt content on skin irritation potential using laser Doppler flowmetry. Fifteen healthy nonsmoking females aged 18-45 years participated in the study. Subjects were randomly assigned to either "Salted" mud group (n = 5), "As is" mud group (n = 5), or "Over-the-Shelf" mud group (n = 5). Five circular areas were marked on the ventral aspect of each forearm. One forearm was assigned randomly for mud treatment and the other forearm was untreated. Ten milliliters of mud was applied on the assigned forearm and left for 30 minutes. Two reading protocols were designed and used to study the effects of tested type of mud on skin blood flux and temperature during mud application (protocol 2) as well as before and after mud removal (protocol 1). All types of tested mud were not associated with a significant measurable elevation in skin temperature and skin blood flow. All types of Dead Sea mud did not cause detectable microcirculatory and skin temperature changes regardless of their different mineral and salts contents.


Assuntos
Fluxometria por Laser-Doppler , Adolescente , Adulto , Feminino , Humanos , Microcirculação , Pessoa de Meia-Idade , Minerais , Dióxido de Silício , Pele , Adulto Jovem
18.
Water Sci Technol ; 80(3): 507-516, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31596262

RESUMO

Adsorption characteristics of high-silica zeolites (HSZSM-5) for two selected sulfonamide antibiotics (SAs) (sulfamethoxazole and sulfadiazine) were investigated. The SAs were almost completely (>90%) removed from the water by HSZSM-5. Adsorption followed second-order kinetics with liquid-film diffusion as the dominant mechanism. SA adsorption capacity on high-silica zeolites was examined in terms of pH, temperature, and the presence of natural organic matter (NOM). HSZSM-5 had better adsorption performance in acidic conditions, and the apparent distribution coefficient indicated that SA0 species were the major contribution to the overall adsorption at pH of 2-10. Adsorption of SAs on HSZSM-5 was a spontaneous and exothermic physisorption process. SA removal by HSZSM-5 was a mixed mechanism through ion-exchange and hydrophobic interaction. HSZSM-5 has potential application prospects in removing SAs from wastewater.


Assuntos
Antibacterianos/análise , Sulfonamidas/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Cinética , Dióxido de Silício
19.
Int J Nanomedicine ; 14: 7237-7247, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31564876

RESUMO

Background: The health hazards of silica nanoparticle (SiNP) are raising worldwide concern as SiNPs has become the second largest manufactured nanomaterial in global markets. However, insufficient data for the adverse health effects and safety evaluation of SiNPs are remaining a big question. Purpose: We evaluated the effects and related mechanism of SiNPs on pulmonary inflammation and collagen production through repeated intravenous administration in mice in a 45-day observation period. Methods: Morphological and ultrastructural change, ultradistribution of SiNPs in lungs were observed in ICR mice through intravenous administration. Oxidative damage, pro-inflammatory cytokines, hydroxyproline content, the marker of fibroblasts and epithelial-mesenchymal transition (EMT), and JAK2/STAT3 and TGF-ß1/Smad3 signaling pathways were detected to explore the lung injuries and related mechanism. Results: The results showed repeated intravenous exposure of SiNPs increased the weight of lung tissues and destroyed pulmonary histomorphological structure. The increased MDA content, depletion of SOD and GSH-Px in lungs were observed in SiNP-treated mice. The protein expressions of JAK2/STAT3 pathway were upregulated in lungs, and the levels of inflammatory cytokines TNF-α, IL-1ß, and IL-6 in serum and lungs were also elevated in SiNPs treated group. The increased hydroxyproline content indicated collagen accumulation in lungs of SiNP-treated mice. Meanwhile, the protein expressions of the marker of myofibroblast (a-SMA), the regulators in connective tissue remodeling (CTGF), TGF-ß, and p-Smad3 were all upregulated in lungs. In addition, we found intravenous administration of SiNPs-induced ultrastructural changes in type II alveolar epithelial cells but without downregulation of the protein expression of the key markers of epithelial cells (E-Cadherin). Conclusion: Our results revealed that oxidative stress and inflammation contributed to the collagen accumulation through activation of JAK2/STAT3 and TGF-ß/Smad3 pathways. It suggests that pulmonary aberrant inflammation and collagen accumulation induced by nanoparticles should be seriously considered for the safety application in diagnostics or therapeutics.


Assuntos
Colágeno/metabolismo , Janus Quinase 2/metabolismo , Nanopartículas/administração & dosagem , Pneumonia/patologia , Transdução de Sinais , Dióxido de Silício/administração & dosagem , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Administração Intravenosa , Animais , Caderinas/metabolismo , Citocinas/metabolismo , Transição Epitelial-Mesenquimal , Fibroblastos/metabolismo , Pulmão/patologia , Pulmão/ultraestrutura , Lesão Pulmonar/patologia , Masculino , Camundongos Endogâmicos ICR , Modelos Biológicos , Miofibroblastos/metabolismo , Nanopartículas/ultraestrutura , Estresse Oxidativo , Fator de Transcrição STAT3/metabolismo
20.
J Agric Food Chem ; 67(44): 12264-12272, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31613615

RESUMO

While silica particles are used extensively in food products, different grades and temperature variants of silica particles have not been compared for their physiochemical and biological properties. Different grades of silica (food-grade nanoparticles (FG-NPs), nonfood-grade nanoparticles (NFG-NPs), and food-grade micron particles (FG-MPs)) and the temperature variants generated by exposing FG-NPs to wet heating, dry heating, and refrigeration were compared for their physicochemical properties and interaction with trypsin. FG-NPs were similar to NFG-NPs and FG-MPs in their elemental composition and amorphous nature but had relatively less branched and ring siloxane groups than the latter ones. There were subtle but noticeable changes in the agglomeration behavior and relative abundance of different silica groups in FG-NPs exposed to food-handling temperatures. Secondary structure and function of trypsin were negatively impacted by FG-NPs and their temperature variants. Silica particles showed a "mixed-type inhibition" of trypsin resulting in partial digestion of bovine serum albumin. In conclusion, our studies showed differences in the surface chemistry of different grades of silica particles and temperature variants of FG-NPs and their negative impact on the structure and function of trypsin.


Assuntos
Aditivos Alimentares/química , Nanopartículas/química , Dióxido de Silício/química , Tripsina/química , Animais , Biocatálise , Bovinos , Hidrodinâmica , Tamanho da Partícula , Soroalbumina Bovina/química , Propriedades de Superfície , Temperatura Ambiente
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