453 research outputs found
Extension of TOPSIS for Group Decision-Making Based on the Type-2 Fuzzy Positive and Negative Ideal Solutions
Abstract In this paper based on the interval type-2 fuzzy sets, we introduce an extension of fuzzy TOPSIS for handling fuzzy multiple attributes group decision making problems. In the proposed method the fuzzy positive ideal solution and fuzzy negative ideal solution are obtained in the form of interval type-2 fuzzy sets without ranking the elements of decision matrix, using the proposed method the solution of decision problem is obtained with less computational attempt than existing methods
Synthesis and characterization of Sm2(MoO4)3, Sm2(MoO4)3/GO and Sm2(MoO4)3/C3N4 nanostructures for improved photocatalytic performance and their anti-cancer the MCF-7 cells
Samarium molybdate nanoparticles (Sm2(MoO4)3) were prepared through a hydrothermal procedure and were used to form various composites with graphene oxide (GO) and carbon nitride (C3N4). The changes in the dimensions and morphology of the products were prepared using template agents like cetyltrimethyl ammonium bromide (CTAB), Sodium dodecyl sulfate (SDS) (�90), Triton X-100 (90), Polyvinyl alcohol (95), Ethylene glycol (�99), and polyvinylpyrrolidone (PVP). DRS analysis indicated band gap for the Sm2(MoO4), Sm2(MoO4)3/GO, and Sm2(MoO4)3/C3N4 as 3.75, 3.15, and 3.4 respectively. The characteristics of the prepared nanostructures were studied through X-ray diffraction (XRD), energy dispersive X-ray (EDX), and scanning electron microscopy (SEM). Finally, the activity of the prepared Sm2(MoO4)3 as photo-catalysts for the degradation of different organic dyes such as methyl orange (MO), methylene blue (MB), and rhodamine B (Rh B) was evaluated. The photocatalytic property of Sm2(MoO4)3/C3N4 and Sm2(MoO4)3/GO for the degradation of MO, was obtained. Based on the empirical data Sm2(MoO4)3/C3N4 had the strongest photodegradation effect as compared to the other compounds tested after around 40 min. BET analysis revealed that the specific surface area of the Sm2(MoO4)3 nanocomposite prepared using C3N4 is 15 times that of in the absence of C3N4. Also, the cytotoxicity of synthesized samples was evaluated using MTT assay against human cell lines MCF-7 (cancer), and its IC50 was about 125 mg/L. © 202
A modified sensitive carbon paste electrode for 5-fluorouracil based using a composite of praseodymium erbium tungstate
This paper describes the modification of a modified carbon paste electrode (CPE) using nanoparticles of praseodymium erbium tungstate (Pr:Er). The modified electrode was used for the sensitive voltammetric detection of an anticancer drug (5-fluorouracil (5-FU)) using. The modified-CPE was evaluated using cyclic voltammetry (CV), square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) and the resulting data showed the irreversible 5-fluorouracil oxidation peak around 1.0 V vs. Ag/AgCl. Some key parameters such as pH, the amount of the modifier, potential amplitude, step potential and frequency were studied and optimized. The square wave voltammetry (SWV) analytical calibration curve was linear in the range of 0.01�50 μM, with a detection limit of 0.98 nM analyses. The electron transfer coefficient (α) was also determined to be 0.76. The analyte concentration was also determined in pharmaceutical formulations and recovery percentages were found to be in the range of 96�102. The sensor had good reproducibility and repeatability with acceptable RSD values of 3.6, and 1.02 and a rather long-term stability of around one month. The as-synthesized nanoparticles were also characterized using FESEM, TEM, FTIR and XRD techniques. © 2020 Elsevier B.V
Electrochemical determination of the antipsychotic medication clozapine by a carbon paste electrode modified with a nanostructure prepared from titania nanoparticles and copper oxide
A nanostructure was prepared from titania nanoparticles and copper oxide (TiO2NP@CuO) and used to modify a carbon paste electrode (CPE). The modified CPE is shown to enable sensitive voltammetric determination of the drug clozapine (CLZ). The sensor was characterized by various techniques and some key parameters were optimized. Under the optimum conditions and at a working potential of 0.6 V (vs. Ag/AgCl), the modified CPE has two linear response ranges, one from 30 pmol L�1 to 4 nmol L�1 of CLZ, the other from 4 nmol L�1 to 10 μmol L�1. The detection limit is as low as 9 pM. The transfer coefficient (α) and catalytic rate constant (kcat) were calculated and the reliability of the sensor was estimated for CLZ sensing in real samples where it gave satisfactory results. Figure not available: see fulltext.. © 2019, Springer-Verlag GmbH Austria, part of Springer Nature
Preparation and characterization of magnetic Fe3O4/CdWO4 and Fe3O4/CdWO4/PrVO4 nanoparticles and investigation of their photocatalytic and anticancer properties on PANC1 cells
Fe3O4/CdWO4 and Fe3O4/CdWO4/PrVO4 magnetic nanoparticles were prepared at different molar ratios of PrVO4 to previous layers (Fe3O4/CdWO4) via the co-precipitation method assisted by a sonochemical procedure, in order to investigate the photocatalytic performance of these systems and their cytotoxicity properties. The physico-chemical properties of these magnetic nanoparticles were determined via several experimental methods: X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier transformation infrared spectroscopy and ultraviolet-visible diffuse reflection spectroscopy, using a vibrating sample magnetometer and a scanning electron microscope. The average sizes of these nanoparticles were found to be in the range of 60-100 nm. The photocatalytic efficiency of the prepared nanostructures was measured by methylene blue degradation under visible light (assisted by H2O2). The magnetic nanosystem with a 1:2:1 ratio of three oxide components showed the best performance by the degradation of ca. 70 after 120 min of exposure to visible light irradiation. Afterwards, this sample was used for the photodegradation of methyl orange, methyl violet, fenitrothion, and rhodamine-B pollutants. Finally, the mechanism of the photocatalytic reaction was examined by releasing �OH under UV light in a system including terephthalic acid, as well as O2-, OH, and hole scavengers. Additionally, the cytotoxicity of each synthesized sample was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay against the human cell line PANC1 (cancer), and its IC50 was approximately 125 mg/L. © 2019 by the authors
Sonochemical synthesis of ErVO4/MnWO4 heterostructures: Application as a novel nanostructured surface for electrochemical determination of tyrosine in biological samples
Present strategy introduces a novel method established for the synthesis of spherical shape ErVO4/MnWO4 heterostructures by a sonochemical method. This heterostructures with optima morphology can be synthesized by changing power and time ultrasound irradiation without any capping agent. BET analysis revealed that ErVO4/MnWO4 prepared in the presence of ultrasonic procedure has 75 times specific surface area as much as that of those was produced in the absence of ultrasonic rays. A variety of analyses (i.e., BET, XRD, TEM, EDS, FT-IR, and SEM) were applied for characterization of the ErVO4/MnWO4. Next, a selective and sensitive nanostructured sensor based on ErVO4/MnWO4 nanocomposite modified carbon paste electrode (ErVO4/MnWO4/CPE) was constructed for electrochemical detection of tyrosine (Tyr). The electrochemical characterizations were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). Compared with the unmodified CPE, the oxidation peak current was significantly enhanced for Tyr. The impact of effective parameters on voltammetric response of Tyr was analyzed with design of experiments (DOE) and response surface methodology (RSM). Under the optimized conditions, the oxidation peak current of Tyr was linear over a range of 0.08�400.0 μM with a detection limit of 7.7 nM. Finally, the usage of the proposed method was confirmed by the recovery tests of Tyr in biological samples. © 201
Acceptability of HIV Rapid Testing in Diverse Clinical Settings in Iran
Introduction: Rapid HIV testing in clinical settings can identify previously undiagnosed persons and link them to care, as well provide patients with knowledge of their serostatus and risk reduction counseling. We conducted a survey to characterize factors affecting the acceptance or declining of rapid HIV testing among Iranian patients.Methods: This cross-sectional survey was conducted from October 2014 to December 2014 with patients in three different health care centers (an emergency department in an urban hospital, a rural health centre, a voluntary counseling and testing centre (VCT) within Imam Khomeini Hospital, Tehran, Iran and a rural health centre). Participants completed a semi-structured face-to-face questionnaire and were tested by an HIV rapid test (Chembio Sure Check).Results: Of 222 participants, 25 participants were from the urban emergency department, 40 from the urban VCT program, and 157 from the rural health care centre. All did the rapid HIV test; all were HIV negative. HIV-related risk profiles found the urban emergency department patients more likely to have multiple partners (26%, P<0.01) and history of sexually transmitted diseases (27%, P<0.001) compared to VCT patients (9% and 3%, respectively) and rural clinic patients (4% and 1%, respectively). Emergency department patients were also more willing to pay for a HIV rapid test (44%, P<0.01), doing a rapid self-test at home (84%,P=0.01), preferring pharmacies as a place for providing rapid tests (80%, P=0.001). Also level of participants’ awareness was considerably different between mentioned centres (median=11, 12, 10 for emergency department, VCT and rural Health care centre respectively; P=0.012).Conclusions: Increasing knowledge about HIV rapid testing, its availability, and keeping costs low can expand the desire to use the test and ultimately prevent the spread of HIV through lack of knowing one’s serostatus and lack of treatment. Emergency departments in urban Iran may be an opportunity to test persons at high risk for HIV infection
Synthesis of magnetic fe3o4/znwo4 and fe3o4/znwo4/cevo4 nanoparticles: The photocatalytic effects on organic pollutants upon irradiation with uv-vis light
Magnetic Fe3O4/ZnWO4 and Fe3O4/ZnWO4/CeVO4 nanoparticles with different molar ratios of CeVO4 to other inorganic components were synthesized through co-precipitation with a sonochemical-assisted method. X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, vibrating sample magnetometry, and scanning electron microscopy (SEM) methods were used for the physico�chemical characterization of the obtained nanoparticles. As shown in the SEM images, the average sizes of the Fe3O4 /ZnWO4 and Fe3O4 /ZnWO4 /CeVO4 nanoparticles that formed aggregates were approximately 50�70 nm and 80�100 nm, respectively. The photocatalytic performance of these nanoparticles was examined by measuring methylene blue degradation under visible light (assisted by H2O2). The sample with a mass ratio of 1:2:1 (Fe3O4/ZnWO4/CeVO4, S4) exhibited optimal photocatalytic performance, and thus this sample was subsequently used for the photodegradation of different organic pollutants upon irradiation with ultraviolet (UV) and visible light. Approximately 90 and 70 degradation of methyl violet and methylene blue, respectively, was observed after visible light irradiation. Additionally, the mechanism of the photocatalytic reaction was investigated by measuring ·OH release under UV light in a system with terephthalic acid and by measuring the release of·O2 �,·OH, and hole scavengers. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
Specific fluorometric assay for direct determination of amikacin by molecularly imprinting polymer on high fluorescent g-C 3 N 4 quantum dots
Here, a specific and reliable fluorometric method for the rapid determination of amikacin was developed based on the molecularly imprinting polymer (MIP) capped g-C 3 N 4 quantum dots (QDs). g-C 3 N 4 QDs were obtained by facile and one-spot ethanol-thermal treatment of bulk g-C 3 N 4 powder and showed a high yield fluorescence emission under UV irradiation. The MIP layer was also created on the surface on QDs, via usual self-assembly process of 3-aminopropyl triethoxysilane (APTES) functional monomers and tetraethyl ortho-silicate (TEOS) cross linker in the presence of amikacin as template molecules. The synthesized MIP-QDs composite showed an improved tendency toward the amikacin molecules. In this state, amikacin molecules located adjacent to the g-C 3 N 4 QDs caused a remarkable quenching effect on the fluorescence emission intensity of QDs. This effect has a linear relationship with amikacin concentration and so, formed the basis of a selective assay to recognize amikacin. Under optimized experimental conditions, a linear calibration graph was obtained as the quenched emission and amikacin concentration, in the range of 3�400 ng mL �1 (4.4�585.1 nM) with a detection limit of 1.2 ng mL �1 (1.8 nM). The high selectivity of MIP sites as well as individual fluorescence properties of g-C 3 N 4 QDs offers a high specific and sensitive monitoring method for drug detection. The method was acceptably applied for the measurement of amikacin in biological samples. © 2019 Elsevier B.V
- …