Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Anal Sci ; 40(4): 755-763, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38379121

RESUMO

The primary aim of the present investigation was to evaluate the efficiency of pure zeolite and activated dithizone zeolite for arsenic(V) removal from aqueous solutions. The analytical eco-scale and analytical greenness for sample preparation results confirm that the proposed method is environmentally friendly. Zeolite adsorbents were characterized and tested for their ability to adsorb arsenic(V) from wastewater. Our study delved into arsenic(V) sorption behavior on pristine and activated zeolites. Through steady-state experiments using pure zeolite and activated dithizone zeolite, we examined the sorption of arsenic from aqueous solutions. We optimized operational parameters, including pH, adsorbent dosage, contact time, and arsenic(V) concentration. Our findings revealed that the Langmuir and Freundlich adsorption isothermal models were highly influential in fitting the experimental data, resulting in statistically significant outcomes. This study highlights the potential of zeolites as outstanding adsorbents for removing arsenic(V) from aqueous solutions. The calculated maximum adsorption capacity (qmax) of pure zeolite and activated dithizone zeolite was 18.2 and 21.1(mg/g), respectively, with R2 = 0.999. According to Freundlich's linear model, the experimental isothermal data indicated that activated dithizone zeolite has a higher value of kf constant and a lower value of the 1/n constant than that obtained for pure zeolite. These results imply favorable adsorption of arsenic(V) on activated dithizone zeolite.

2.
BMC Chem ; 17(1): 136, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37817268

RESUMO

Economical, highly robust, selective, precise, and eco-friendly RP-UPLC and spectrophotometric methods were developed and validated for the concurrent estimation of selected pharmaceutical drugs represented in ceftazidime (CFZ) and pyridine (PYD) in their solutions using Agilent Zorbax SB-C18 RRHD (50 × 2.1 mm, 1.8 µm) column at flow rate 0.3 mL/min with wavelength 254 nm. Box-Behnken design (BBD) established Response surface methodology (RSM) to achieve the optimum chromatographic condition with minimal trials conducted. Three independent variables specifically acetonitrile ratio 60-70%, pH 3-7, and temperature 25-35 °C were implemented to evaluate the influences of these variables on the responses as resolution and retention time. Desirability and overlay plots were carried out to adjust the optimal condition that achieved the shortest retention time of less than 2 min and desired resolution of more than 1.5 using a mobile phase consisting of acetonitrile: purified water (70:30, v/v) at pH 5.0 adjusted by 0.1% orthophosphoric acid with the column oven temperature 30 °C and column void volume 0.46 mL. Mean centering of ratio spectra (MCR) and ratio subtraction (RS) methods were effectively applied to resolve drugs' spectral superposition at 220 nm, 255.4 nm, 260.3 nm, and 254.6 nm for CFZ and PYD, respectively. Linearity range was accomplished for UPLC, MCR, and RS methods over the concentration range of 2-100, 1-50,3-30 and 5-30 µg/mL for CFZ and PYD, respectively with correlation coefficient > 0.999 and good recovery results within 98-102%. Six Sigma methodology was achieved using the process capability index (Cpk) to compare the suggested and USP methods showing that both are highly capable with Cpk > 1.33. The proposed method was successfully validated depending on ICH guidelines and ANOVA results and applied for the accelerated stability study.

3.
Artigo em Inglês | MEDLINE | ID: mdl-32098178

RESUMO

It has been reported that spinal deformity was induced in developing fish by the addition of polycyclic aromatic hydrocarbons (PAHs). To examine the mechanism of the disruption of fish bone metabolism, the effect of benz[a]anthracene (BaA), a kind of PAH, on plasma calcium, inorganic phosphorus, osteoblasts, and osteoclasts was investigated in this study. We also measured several plasma components to analyze the toxicity of BaA on other metabolisms. BaA (1 or 10 ng/g body weight) was intraperitoneally injected (four times) into nibbler fish during breeding, for 10 days, and it was indicated, for the first time, that injecting high doses of BaA to nibbler fish induced both hypocalcemia and hypophosphatemia. Furthermore, in the scales of nibbler fish treated with high doses of BaA, both osteoclastic and osteoblastic marker messengerRNA (mRNA) expressions decreased. These results are a cause of disruption of bone metabolism and, perhaps, the induction of spinal deformities. In addition, we found that total protein, metabolic enzymes in the liver, total cholesterol, free cholesterol, and high-density lipoprotein cholesterol levels significantly decreased in BaA-injected fish. These results indicate that BaA may affect liver diseases and emphasize the importance of prevention of aquatic PAH pollution.


Assuntos
Antracenos , Peixes , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Antracenos/toxicidade , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Osteoclastos , Poluentes Químicos da Água/toxicidade
4.
RSC Adv ; 9(56): 32544-32561, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-35529712

RESUMO

Nowadays, improving the physico-chemical properties of nanomaterials to enhance their performance towards various applications is urgent. Accordingly, gamma irradiation (GI) has evolved and attracted wide attention as a promising green technique to meet this need. In the current study, a Co-Fe LDH was used as a model 2D nanomaterial and was irradiated by GI (dose = 100 kGy). The sample was characterized via XRD, FTIR, FESEM, HRTEM, hydrodynamic size, zeta potential, and BET surface area measurements. The results showed that after irradiation, the surface area of the sample increased from 83 to 89 m2 g-1. Moreover, irradiation increased its dielectric constant, dielectric loss and AC conductivity. In addition, the sample showed superparamagnetic behavior, where its saturation magnetization increased from 1.28 to 52.04 emu g-1 after irradiation. Furthermore, the adsorption capacity of the irradiated LDH towards malachite green (MG) and methylene blue (MB) as model wastewater pollutants was also studied. The exposure of LDH to GI enhanced its adsorption capacity for MG from 44.73 to 54.43 mg g-1. The Langmuir-Freundlich, Sips, and Baudu models were well suited for both MG and MB adsorption among the six fitted isotherm models. The pseudo-first and second order models fit the adsorption kinetics better than the intraparticle diffusion model for both dyes. The interaction of MB and MG with the LDH surface was further investigated in dry and aqueous solution using Grand canonical Monte Carlo and molecular dynamics simulations. These two techniques provided insight into the adsorption mechanism, which is vital to understand the adsorption process by the LDH nanosheets and their possible use in practical applications. Moreover, the Co-Fe LDH showed good antibacterial activity against both Gram-positive and Gram-negative bacteria strains. Furthermore, due to its magnetic property, the Co-Fe LDH could be simply recovered from water by magnetic separation at a low magnetic field after the adsorption process.

5.
Mar Pollut Bull ; 127: 618-625, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29475705

RESUMO

Dioxins have global concerns because of the bioaccumulation tendency and persistency in the environment. Water, seabream Pagrus auratus and seabass Dicentrarchus labrax samples were collected from Abu Qir, Alexandria to evaluate the concentration of dioxin. Fourier Transform Infrared Spectrometer (FTIR) and molecular modeling was applied for elucidating the molecular structure of fish samples. Furthermore, HPLC with UV detection was used to determine the concentration of dioxins (2,8-dichloro dibenzo-p-dioxin). RT-PCR assay was conducted to verify the expression of some immune genes in the fish species as a result of water pollution. The average detected concentrations varied from 0.2 to 1.3µg/l. Gene expression revealed that MHC class 1 and C3 were highly upregulated in liver and muscle of seabass and seabream while T2BP was highly regulated in seabass liver and seabream muscle and seabass muscle for transferrin, FTIR and molecular modeling indicate that dioxin finds its way to fish protein.


Assuntos
Bass/genética , Dano ao DNA , Dioxinas/toxicidade , Monitoramento Ambiental/métodos , Mutagênicos/toxicidade , Dourada/genética , Poluentes Químicos da Água/toxicidade , Animais , Egito , Proteínas de Peixes/genética , Mar Mediterrâneo
6.
Zoolog Sci ; 33(4): 407-13, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27498800

RESUMO

We have developed an original in vitro bioassay using teleost scale, that has osteoclasts, osteoblasts, and bone matrix as each marker: alkaline phosphatase (ALP) for osteoblasts and tartrate-resistant acid phosphatase (TRAP) for osteoclasts. Using this scale in vitro bioassay, we examined the effects of seawater polluted with highly concentrated polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) on osteoblastic and osteoclastic activities in the present study. Polluted seawater was collected from two sites (the Alexandria site on the Mediterranean Sea and the Suez Canal site on the Red Sea). Total levels of PAHs in the seawater from the Alexandria and Suez Canal sites were 1364.59 and 992.56 ng/l, respectively. We were able to detect NPAHs in both seawater samples. Total levels of NPAHs were detected in the seawater of the Alexandria site (12.749 ng/l) and the Suez Canal site (3.914 ng/l). Each sample of polluted seawater was added to culture medium at dilution rates of 50, 100, and 500, and incubated with the goldfish scales for 6 hrs. Thereafter, ALP and TRAP activities were measured. ALP activity was significantly suppressed by both polluted seawater samples diluted at least 500 times, but TRAP activity did not change. In addition, mRNA expressions of osteoblastic markers (ALP, osteocalcin, and the receptor activator of the NF-κB ligand) decreased significantly, as did the ALP enzyme activity. In fact, ALP activity decreased on treatment with PAHs and NPAHs. We conclude that seawater polluted with highly concentrated PAHs and NPAHs influences bone metabolism in teleosts.


Assuntos
Carpa Dourada , Tegumento Comum , Osteoblastos/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Água do Mar/química , Poluentes Químicos da Água/toxicidade , Animais , Regulação da Expressão Gênica , Marcadores Genéticos , Hidrocarbonetos Policíclicos Aromáticos/química , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Poluentes Químicos da Água/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...