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1.
J Hazard Mater ; 417: 126038, 2021 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-34015714

RESUMO

In the present work, spherical carboxymethyl cellulose-cellulose-nickel (CMC-C-Ni) composite beads as novel adsorbent was synthesized to make a stable expanded bed adsorption (EBA) column for the treatment of the oily wastewater collected from the downstream of rapeseed industry. The morphology and structure of the CMC-C-Ni composite beads were studied by scanning electron microscopy (SEM) and optical microscope. The SEM images revealed that the synthesized composite beads were spherical with porous structure. The pore size of the beads was in the range of 90-200 nm. The physical characteristics of the CMC-C-Ni composite beads including wet density, porosity, and water content were respectively in the ranges of 1.23-1.63 g/cm3, 82.29-90.75%, and 52-76%. The factor of bed expansion in the range of 2-3 was corresponded with Richardson-Zaki equation. The results showed that by increasing the fluid viscosity, the terminal settling velocity (Ut) was reduced. The expansion index values were between 2.77 and 3.14 that were close to 4.8 (commonly utilized index in the laminar flow regimes). CMC-C-Ni composite beads were tested when the velocity of fluid was ˂ 700 cm/h, and the Daxl was found to be ˂ 1 × 10-5 m2/s (steady state).


Assuntos
Níquel , Águas Residuárias , Adsorção , Carboximetilcelulose Sódica , Porosidade
2.
Food Chem ; 356: 129731, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33839533

RESUMO

The aim of this study was to optimize the preparation of whey protein concentrate (WPC)-pectin nanocomplexes as a carrier for rose essential oil (REO) via response surface methodology (RSM); with initial concentrations of WPC (4-8%) and pectin (0.5-1%) at different pH values ​​(3-9). The highest encapsulation efficiency of REO was 96.97% for 4.0:0.5 ratio of WPC:pectin at pH = 3. The highest viscosity was obtained at 4:1 ratio of WPC:pectin and pH = 3, and the highest stability (96.5%) was related to 4:1 ratio of WPC:pectin at pH = 9; the lowest stability (81%) was observed at 4:1 ratio of WPC:pectin at pH = 3. Finally, the highest solubility occurred at pH = 9 while the lowest solubility was seen in the treatments prepared at pH = 3 due to the creation of a strong WPC-pectin coacervate complex.


Assuntos
Nanoestruturas/química , Óleos Voláteis/química , Pectinas/química , Rosa/química , Proteínas do Soro do Leite/química , Cápsulas , Concentração de Íons de Hidrogênio , Solubilidade , Viscosidade
3.
Talanta ; 221: 121620, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33076148

RESUMO

In this study, a magnetic molecularly imprinted polymer (MMIP (Fe3O4@SiO2-MIP)) was used for the dispersive magnetic solid-phase microextraction (d-MSP-µ-E) to design an easy and effective method for melatonin (MLT) extraction in the methanolic extract of Portulaca oleracea, human urine and plasma, and water samples. HPLC with UV detection was utilized, and pH, the type and volume of eluent, MMIP mass, and contact time were considered as effective factors in the study of MLT separation and pre-concentration. These factors were optimized by Plackett-Burman and multi-objective response surface methodology (RSM). The values were 10 mg, 14 min, 4.2, methanol, 0.180 mL, 2.5 min, for the MMIP mass, time of sorption, sample pH, eluent type, eluent volume, and time of elution, respectively. At the optimum conditions, the limit of detection (LOD) was 0.046 ng mL-1, and the limit of quantification (LOQ) was 0.156 ng mL-1. The sorption capacity of the proposed MMIP sorbent was 109.1 mg g-1 at the optimum conditions. Besides, linear dynamic range (LDR) was 0.2-4200 ng mL-1, and the precision of the method (RSD %) for triplicate measurements was <6.1%. The MMIP showed saturation magnetization of 19.75 emu g-1, resulting in fast separation of the sorbent. The sorption test revealed the high sorption capacity of the MMIP for MLT and its homogeneous binding sites. In all spiked levels (50, 100, 200, and 500 ng mL-1), 93.07-104.1% was the range obtained for the recovery of MLT. The relative selectivity factor (ß) values of MLT/tryptophan, MLT/serotonin, MLT/ferulic acid, MLT/mefenamic acid, MLT/quercetin, MLT/luteolin, and MLT/chlorogenic acid were 1.60, 1.68, 2.02, 2.38, 2.32, 2.40, and 2.50, respectively. The results of desorption-regeneration cycles (seven times) by employing the MMIP showed the high stability of the resultant material. In conclusion, the MMIP combined with the magnetic separation showed a specific sorption behavior for MLT and suggested a simple, flexible, selective, and powerful analytical tool.


Assuntos
Melatonina , Impressão Molecular , Portulaca , Adsorção , Cromatografia Líquida de Alta Pressão , Humanos , Limite de Detecção , Metanol , Extratos Vegetais , Polímeros , Dióxido de Silício , Água
4.
J Sep Sci ; 43(24): 4469-4479, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33048447

RESUMO

In the present work, nickel-1,4-benzenedioxyacetic acid was synthesized as a rod-like metal organic material and then modified with alumina nanoparticles to synthesize nickel metal organic modified-Al2 O3 nanoparticles. The material was found as an efficient sorbent for the enrichment of atorvastatin in human blood plasma. After the extraction of the sample of plasma by ultrasound-assisted dispersive solid phase extraction, high performance liquid chromatography-ultraviolet was used to determine the quantitatively pre-concentrated interest analyte. The conditions for optimum extraction were achieved by the optimization of the volume of eluent, dosage of the sorbent, and time of sonication. Solution pH of 7.0, 250 µL of ethanol, 45 mg of the sorbent, and 10 min of sonication time were the conditions for extracting the atorvastatin maximum recovery of higher than 97.0%. By using desirability function for the optimization of the process, the present method showed a response that was linear ranging from 0.2 to 800 ng/mL with regression coefficient of 0.999 in the plasma of human blood with a satisfactory detection limit of 0.05 ng/mL, while the precision of interday for the current method was found to be <5%. It can be concluded that dispersive solid phase extraction method is effective for the extraction of atorvastatin from human plasma samples (97.4-102%) due to its easy operation, simplicity, repeatability, and reliability.


Assuntos
Óxido de Alumínio/química , Atorvastatina/sangue , Estruturas Metalorgânicas/química , Nanopartículas/química , Extração em Fase Sólida , Ondas Ultrassônicas , Ácido Acético/química , Cromatografia Líquida de Alta Pressão , Humanos , Estruturas Metalorgânicas/síntese química , Níquel/química , Tamanho da Partícula
5.
Res Pharm Sci ; 13(5): 404-412, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30271442

RESUMO

Stachys pilifera (S. pilifera) Benth (Lamiaceae) is used in traditional medicine to treat a variety of diseases. Despite some reports on the antitumor effects of some species of this genus, anticancer activity of S. pilifera has not been yet reported. Here, we examined the cytotoxic effect and cell death mechanisms of methanolic extract of S. pilifera and its alkaloid and terpenoid fractions on the HT-29 colorectal cell line. HT-29 cells were cultivated and then incubated in the methanolic extract of S. pilifera and its fractions at various concentrations for 24 h. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Morphology of cells was evaluated by contrast microscopy. Furthermore, effects of the tested extract and fractions were tested on some regulators of cell death and proliferation such as caspase-8, caspase-9, nuclear factor-κB (NF-κB), and nitric oxide (NO). Cisplatin was used as positive control. The estimated IC50 values of the methanolic extract, alkaloid and terpenoid fractions, and cisplatin against HT29 cell after 24 h were determined to be 612, 48.12, 46.44, and 4.02 µg/mL, respectively. Morphological changes such as plasma membrane blebbing, cell size reduction, and apoptotic bodies were observed in cells faced with the extract and fractions. S. pilifera extract and its fractions induced apoptosis through inhibition of NF-κB, NO, and activation of caspase-8 and caspase-9. Data showed considerable cytotoxic and antiproliferative effects of S. plifera on colorectal cell line through induction of apoptosis. These findings provide a basis for the therapeutic potential of S. pilfera in the treatment of colon cancer.

6.
J Pharm Biomed Anal ; 149: 166-171, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29121570

RESUMO

In this research, a facile and selective method was described to extract l-cysteine (l-Cys), an essential α-amino acid for anti-ageing playing an important role in human health, from human blood plasma sample. The importance of this research was the mild and time-consuming synthesis of zinc organic polymer (Zn-MOP) as an adsorbent and evaluation of its ability for efficient enrichment of l-Cys by ultrasound-assisted dispersive micro solid-phase extraction (UA-DMSPE) method. The structure of Zn-MOP was investigated by FT-IR, XRD and SEM. Analysis of variance (ANOVA) was applied for the experimental data to reach the best optimum conditions. The quantification of l-Cys was carried out by high performance liquid chromatography with UV detection set at λ=230nm. The calibration graph showed reasonable linear responses towards l-Cys concentrations in the range of 4.0-1000µg/L (r2=0.999) with low limit of detection (0.76µg/L, S/N=3) and RSD≤2.18 (n=3). The results revealed the applicability and high performance of this novel strategy in detecting trace l-Cys by Zn-MOP in complicated matrices.


Assuntos
Cisteína/sangue , Estruturas Metalorgânicas/química , Microextração em Fase Sólida/métodos , Zinco/química , Adsorção , Envelhecimento/sangue , Análise de Variância , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Cisteína/química , Estudos de Viabilidade , Humanos , Limite de Detecção , Estruturas Metalorgânicas/ultraestrutura , Microscopia Eletrônica de Varredura , Difração de Pó/instrumentação , Difração de Pó/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/instrumentação , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Propriedades de Superfície , Ondas Ultrassônicas , Difração de Raios X/instrumentação , Difração de Raios X/métodos
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