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1.
J Contam Hydrol ; 250: 104052, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35908294

RESUMO

Graphene and its composites with semiconductor materials have been received highly attention in many research areas because of their unique properties. Efficient application of graphene is hindered by the lack of cost-effective synthesis methods. In this work, an economic and facile route for mass production of graphene-titanate nanocomposite has been discussed. Graphene was prepared by exfoliation of graphite powder in 40% ethanol aqueous solution. Titanate nanotubes were grown on graphene sheets by hydrothermal method, where the dispersed graphene sheets were mixed with titanate solution and then placed in autoclave and placed in oven for 16 h at 160 °C. The prepared composite was characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), Fourier transforms infrared spectroscopy (FTIR), thermogravimetric analysis (TGA). All the obtained results confirmed the synthesis of graphene and its composite with titanate in highly uniform and pure form. The adsorption efficiency of the prepared composite was tested using methylene blue (MB) as a model dye. The adsorption isotherm was investigated using Freundlich and Langmuir models. The adsorption capacity of MB was 270.27 mg/g. The obtained correlation coefficients (R2) by Freundlich and Langmuir model were 0.996 and 0.973, respectively. The adsorption kinetics was investigated and discussed using different models. The thermal stability of the developed composite is improved after MB adsorption.


Assuntos
Grafite , Nanocompostos , Poluentes Químicos da Água , Purificação da Água , Adsorção , Etanol , Grafite/química , Cinética , Azul de Metileno/química , Nanocompostos/química , Pós , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química , Poluentes Químicos da Água/química , Purificação da Água/métodos
2.
Toxicol Ind Health ; 36(4): 272-286, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32552542

RESUMO

The present research investigated the impact of the morphology change of titanate (TiO2) nanostructures on its tissue distribution and toxicity. The TiO2 nanotubes, rods, and ribbons were synthesized by the hydrothermal technique, and the morphology was adjusted by alteration of the hydrothermal duration time. The characterization techniques were X-ray diffraction, high-resolution transmission electron microscopy, dynamic light scattering, and the Brunauer-Emmett-Teller method for measuring the surface area. The intravenously administrated dose (5 mg/kg) was injected as a single dose for 1 day and consecutively for 42 days. The quantitative analysis of accumulated TiO2 nanostructures in the liver, spleen, and the heart was performed using an inductively coupled plasma emission spectrometer, and the organs' toxicity was estimated by histopathological analysis. The prepared nanostructures exhibited differences in morphology, crystallinity, size distribution, surface area, zeta potential, and aspect ratio. The results revealed a tissue distribution difference between the liver, spleen, and heart of these nanostructures, the distribution order was the liver, spleen, and the heart for all TiO2 nanostructures. The toxicity was induced with different degrees. The nanotubes were the most harmful among the three formats. In summary, changes in the morphology of the TiO2 nanostructures change its distribution and toxicity.


Assuntos
Coração/efeitos dos fármacos , Fígado/efeitos dos fármacos , Nanotubos/toxicidade , Baço/efeitos dos fármacos , Titânio/toxicidade , Animais , Egito , Fígado/patologia , Masculino , Miocárdio/patologia , Nanoestruturas/toxicidade , Ratos , Baço/patologia
3.
Int J Nanomedicine ; 15: 619-631, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32099355

RESUMO

BACKGROUND: Certainly, there is a demand for stronger recognition of how nanoparticles can move through the cell membrane. Prostate cancer is one of the forcing sources of cancer-relevant deaths among men. AIM OF THE WORK: The current research studied the power of prostate cancer cells to uptake a ternary nanocomposite TNT/CuFe2O4/Zn-Fe mixed metal oxides (MMO). METHODOLOGY: The nanocomposite was synthesized by a chemical method and characterized by a High-resolution transmission electron microscope, Field emission scanning electron microscope, X-ray diffraction, Fourier transmission infra-red, X-ray photoelectron spectroscopy, dynamic light scattering. Besides, it was implemented as an inorganic anticancer agent versus Prostate cancer PC-3 cells. RESULTS: The results revealed cellular uptake validity, cell viability reduction, ultra-structures alterations, morphological changes and membrane damage of PC-3 cells. CONCLUSION: The prepared ternary nanocomposite was highly uptake by PC-3 cells and possessed cytotoxicity that was dose and time-dependent. To conclude, the study offered the potential of the investigated ternary nanocomposite as a promising prostate anticancer agent.


Assuntos
Antineoplásicos/farmacocinética , Nanocompostos/química , Nanotubos/química , Neoplasias da Próstata/tratamento farmacológico , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular , Cobre/química , Difusão Dinâmica da Luz , Humanos , Ferro/química , Masculino , Microscopia Eletrônica de Transmissão , Nanocompostos/administração & dosagem , Óxidos/química , Espectroscopia Fotoeletrônica , Neoplasias da Próstata/patologia , Titânio/química , Difração de Raios X , Zinco/química
4.
Int J Biol Macromol ; 146: 1169-1179, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31739021

RESUMO

For cost effective fatty acid methyl esters (FAME) production, nanoparticles are used to make microbial lipase more stable and reusable. Sodium titanate nanotubes (TNT) were prepared by simple hydrothermal method for immobilization of different concentrations of lipase. All samples were characterized by XRD, FTIR and HRTEM. Samples of different concentrations of immobilized lipase on titanate nanotubes (TNT-L) were tested for FAME production against free lipase & pure TNT at 40 °C for 90 min. It was found that TNT-L achieved high conversion percentages even at low immobilized lipase concentrations, compared to free lipase. Immobilized lipase on TNT demonstrated enhanced recycling stability for 10 consecutive cycles, suggesting its use for FAME production.


Assuntos
Aspergillus niger/enzimologia , Enzimas Imobilizadas/metabolismo , Ésteres/metabolismo , Ácidos Graxos/metabolismo , Lipase/metabolismo , Nanotubos/química , Óxidos/química , Titânio/química , Metilação , Nanocompostos/química , Nanotubos/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
5.
Epidemiol Infect ; 143(13): 2856-64, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25591942

RESUMO

We aimed to reparameterize and validate an existing dengue model, comprising an entomological component (CIMSiM) and a disease component (DENSiM) for application in Malaysia. With the model we aimed to measure the effect of importation rate on dengue incidence, and to determine the potential impact of moderate climate change (a 1 °C temperature increase) on dengue activity. Dengue models (comprising CIMSiM and DENSiM) were reparameterized for a simulated Malaysian village of 10 000 people, and validated against monthly dengue case data from the district of Petaling Jaya in the state of Selangor. Simulations were also performed for 2008-2012 for variable virus importation rates (ranging from 1 to 25 per week) and dengue incidence determined. Dengue incidence in the period 2010-2012 was modelled, twice, with observed daily weather and with a 1 °C increase, the latter to simulate moderate climate change. Strong concordance between simulated and observed monthly dengue cases was observed (up to r = 0·72). There was a linear relationship between importation and incidence. However, a doubling of dengue importation did not equate to a doubling of dengue activity. The largest individual dengue outbreak was observed with the lowest dengue importation rate. Moderate climate change resulted in an overall decrease in dengue activity over a 3-year period, linked to high human seroprevalence early on in the simulation. Our results suggest that moderate reductions in importation with control programmes may not reduce the frequency of large outbreaks. Moderate increases in temperature do not necessarily lead to greater dengue incidence.


Assuntos
Aedes , Mudança Climática , Dengue/epidemiologia , Dengue/transmissão , Entomologia/métodos , Modelos Teóricos , Animais , Humanos , Malásia/epidemiologia , Software
6.
Acta Biol Med Ger ; 38(11-12): 1485-95, 1979.
Artigo em Inglês | MEDLINE | ID: mdl-399422

RESUMO

Oral administration of carnitine in normal and diabetic subjects showed a marked decrease in the level of blood glucose during the oral glucose tolerance test (OGTT) except for the three hour samples in diabetic subjects, while a decrease in the level of subsequent blood pyruvate samples was observed during the OGTT in normal and diabetic subjects after the administration of carnitine. During the OGTT, the peak of blood glucose and blood pyruvate level was generally delayed in the diabetic subjects. Furthermore, the mean blood pyruvate levels were elevated above those of normal subjects during the late stages of the test. The mean levels of blood glucose and blood pyruvate of all samples after the administration of carnitine were significantly higher in diabetics than the corresponding values in noramls. Carnitine administration decreased the total blood amino acid nitrogen level only in diabetic subjects. Carnitine caused a highly significant increase in the activity of serum alanine aminotransferase in normal and diabetic subjects, while it had no effect on the activity of serum aspartate aminotransferase. In goats, the level of blood glucose during the intravenous glucose tolerance test (IVGTT) was not affected by carnitine (1,3 or 6 mg/kg body weight). Carnitine in all doses used had no effect on the total blood amino acid nitrogen during the IVGTT, or on the activity of serum alanine aminotransferase and serum aspartate aminotransferase in the fasting samples. Acetyl-D,L-beta-methylcholine had no effect on the level of blood glucose, total blood amino acid nitrogen, the activity of serum alanine aminotransferase or serum aspartate aminotransferase in normal and diabetic subjects. The level of blood pyruvate decreased both in normal and diabetic subjects, in the samples that represented the peak of the curve. Glycine betaine had no effect on blood glucose, pyruvate, total blood amino acid nitrogen and the activity of serum alanine aminotransferase or serum aspartate amino transferase in normal and diabetic subjects or in goats.


Assuntos
Betaína/farmacologia , Glicemia/metabolismo , Carnitina/farmacologia , Cabras/sangue , Compostos de Metacolina/farmacologia , Adulto , Idoso , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Diabetes Mellitus/sangue , Jejum , Feminino , Teste de Tolerância a Glucose , Humanos , Masculino , Cloreto de Metacolina , Pessoa de Meia-Idade , Nitrogênio/sangue , Piruvatos/sangue
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