جستجوی مقالات مرتبط با کلیدواژه « central composite design » در نشریات گروه « پزشکی »

Lamotrigine is widely used in the management of partial epilepsy, generalized tonic-clonic epilepsy and Lenox-Gastut syndrome and is an add-on therapy in the treatment of complex and simple partial seizures and secondarily generalized tonic-clonic seizures resistant to multiple drug therapy.

In the current study, a fluorometric nanoprobe based on metal–organic frameworks (MOF) was designed for the determination of lamotrigine in exhaled breath condensate (EBC). The MOF nanoprobe consisted of Tb3+ ions as metal part and dimethylformamide (DMF) and 1,10-phenanthroline (Phen) as organic parts of nanoprobe.

The used probe shows a weak fluorescence in alkaline media owing to an energy transfer from nitrogen groups of DMF and Phen on carbonyl group of DMF as an antenna for Tb3+ luminescence. However, its fluorescence is enhanced in acidic conditions by protonation of DMF nitrogen atoms and Phen and deactivation of energy transfer pathways of nitrogen groups to carbonyl group. Lamotrigine addition to this fluorescent system leads to quenching in the fluorescence intensity due to reactivation of the above mentioned energy transfer pathways resulting in competitive interaction with H+ ions. Moreover, the inner filter effect (IFE) of lamotrigine on DMF–Tb–Phen MOF NPs is considered as another reason for the observed quenching in the fluorescence of DMF–Tb–Phen MOF NPs. The intensity of the fluorescence was recorded at λem = 545 nm and the difference between fluorescence signal in the absence and presence of lamotrigine was the analytical response. The factors affected on experimental conditions were optimized utilizing a multivariate optimization technique. The validation of nanoprobe response to lamotrigine gives a linear relationship in the range of 0.05 to 2.0 µg⋅mL‒1 with a detection limit of 11.0 ng⋅mL‒1 for lamotrigine.

The developed method reveals good repeatability and selectivity for lamotrigine in real samples.

Corchorus olitorius L. is a medicinal herb with anti-inflammatory, laxative, and tonic properties, which is effective on the treatment of cancer and tumors. In this study, the extraction efficiency of supercritical fluid extraction (SFE) and ultrasound-assisted extraction (UAE) of C. olitorius as well as their antioxidant activities were investigated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical. For this purpose, central composite block cube star and central composite design were employed to determine the optimal conditions. Thereafter, the qualification analysis of the effective ingredients of C. olitorius was done by LC-ESI-MS in negative mode. The results of LC-MS showed that C. olitorius includes phenolic and flavonoid compounds such as caffeic acid, p-coumaric acid, trans-ferulic acid, quercetin, naringenin, cirsiliol, cirsilineol, quercetrin, and naringin. Moreover, the SFE efficiency of extraction and IC50 value was obtained 4.25% and 1208.99 µg/mL, respectively. Also, the UAE efficiency of extraction and IC50 of antioxidant activity was obtained as 15.29% and 994.284 µg/mL, respectively. These results confirmed that the efficiencies of extraction and antioxidant activity of UAE were higher than that of SFE; however, the SFE is an environmentally friendly method and consumed less organic solvent.

Nowadays, enzyme-based removal of hazardous dyes that pollute the environment has been considered as a substitute and eco-friendly method compared to the physical and chemical method. The present study was conceived in order to obtain the optimal condition for laccase-mediated (purified from the Pleurotus ostreatus PKN04) decolorization of Remazol Brilliant Violet 5R dye; a mono-azo dye, using the central composite design of response surface methodology (RSM).

The design of experiment was suggested with 6 variables including pH, temperature, incubation time, agitation, dye concentration, and enzyme concentration, which were applied in order to optimize the decolorization process. The kinetic and energetic factors of laccases for the enzymatic removal of Remazol Brilliant Violet 5R dye was investigated.

Decolorization of Remazol Brilliant Violet 5R was maximally 95.72%, which had occurred at 6.0 pH, 40°C temperature, 60 minutes incubation time, 50 rpm agitation, 50 ppm dye concentration, and 100 IU/mL enzyme concentration. The obtained results of kinetic introduced the laccase-catalyzed decolorization of Remazol Brilliant Violet 5R as an endothermic reaction with Km and Vmax values of 0.801 mM and 387 mM/mg/min, respectively. In addition to the above results, the toxicity study against bacteria revealed that the toxicity of laccase-treated dye drastically reduced to the untreated dye.

The results of the present analysis reveal that the Pleurotus ostreatus laccase is an efficient biocatalyst for decolorization of synthetic dye Remazol Brilliant Violet 5R dye.

 The sonoelectrochemical mineralization of the synthetic aqueous solution of the perfluorooctanoic acid (PFOA) on Ti/PbO 2 anode was investigated using the response surface methodology based on a central composite design (CCD). 

 The CCD was performed using three different variables such as current density (CD) (mA/cm 2 ), pH, and supporting electrolyte (EL) concentration (mM). The total organic carbon (TOC) removal was determined as an indicator of PFOA mineralization. A Shimadzu TOC analyzer was used to measure the TOC of the samples. The Ti/PbO 2 electrode was prepared using the electrochemical deposition method. In order to enhance the electrochemical mineralization, ultrasonic (US) radiation was used. The US frequency was 20 kHz. 

 The optimum conditions for PFOA mineralization in synthetic solution were EL concentration of 94 mM, pH of 2, and CD of 83.64 mA/cm 2 , which resulted in complete TOC removal. The results indicated that the most effective factor for PFOA mineralization was CD. Besides, the TOC removal efficiency significantly increased with increasing CD. 

 Under optimum conditions, the mineralization of PFOA was almost completed after 90 min of sonoelectrolysis. Therefore, sonoelectrolysis was found to be a more effective technique for mineralization of an environmentally persistent compound.