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191.
Leila Samandari Azam Bahrami Beshare Hashemi 《International journal of environmental analytical chemistry》2019,99(2):172-186
Cadmium (Cd) is known as one of the most toxic elements among the heavy metals. This study proposes an electrochemical preconcentration method using the ion imprinted polymer nanoparticles modified carbon paste electrode (IIP-CPE) for the stripping voltammetry determination of Cd2+ in the environmental and biological samples. These IIP NPs were synthesised using ethylene glycol dimethacrylate as the cross-linker, 2,2?-azobisisobutyronitrile as the free radical initiator and 4?-(4-vinylphenyl)-2,2?:6?,2?-terpyridine as the Cd-binding ligand. The calibration plot was linear in the concentration range of 4–500 nM (R2 = 0.9936) with a sensitivity of 918 µA µM?1 cm?2. The LOD based on 3Sb/m (where m is the slope of the calibration curve and Sb is the standard deviation for five blank measurements) was found to be 1.94 nM. The relative standard deviations (RSDs) for single-electrode repeatability and electrode-to-electrode reproducibility were 3.0% and 5.6% (n = 5), respectively. The accuracy of the current method was confirmed by the analysis of urine quality control material (QCM, SeronormTM Trace Elements Urine, REF NO 201205, Norway) and spiked blood, rice and water samples. Recoveries were found to be above 95.0% for all samples, which confirms the good performance of the proposed voltammetry method. 相似文献
192.
Mounir Gahgah;Mohamed Kezzar;Naveen Dwivedi;Abdelaziz Nehal;Mohamed Rafik Sari;Ismail Tabet;Sultan Alshehery;Abdulrahman F. Aljohani;Ilyas Khan; 《ZAMM - Journal of Applied Mathematics and Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik》2024,104(12):e202300911
The mathematical modeling of blood flow with the incorporation of ternary hybrid nanoparticles (i.e., titania, silica, and alumina nanoparticles) is the focus of this work. The flow of blood is simulated using the Casson fluid model. The impacts of ternary hybrid nanoparticles, shape factor, and Geometry of solid nanoparticles are visualized and investigated. The momentum and thermal characteristics of a flowing liquid are determined by considering magnetization, porosity, and nonlinearized radiating thermal flux. The basic partial differential equations resulting from mathematical modeling are turned into non-linear ordinary differential equations using suitable velocity transforms. The derived nonlinear equations are then numerically calculated using the 4th-5th order Runge-Kutta-Fehlberg method with the shooting technique and analytically solved by the Adomian decomposition method (ADM). The effects of the factors involved on the dimensionless profiles produced are fully addressed. It is found that the Skin friction factor and heat transfer rate in the radial direction upsurge with the augment of both rotation parameter and nanoparticles volume fraction; however, the Skin friction factor drops in the azimuthal direction. Also, results obtained reveal an enhancement in the local Nusselt number with the upsurge in the magnitude of radiation parameter, Rd, solid nanoparticles concentration, φ$ varphi $, shape factor value, s, and disk temperature, θf${{theta }_f}$. For validation, the outcomes of this inquiry were compared to the outcomes of the HAM-based Mathematica software. In addition, the acquired analytical DRA data are compared to numerical RKF45 values and those given in the literature. 相似文献
193.
Malik Abdul Rub Naved Azum Abdullah M. Asiri Mohie E. M. Zayed Abdulrahman O. Al‐Youbi 《Journal of Physical Organic Chemistry》2016,29(9):476-489
The current work deals with the mixed micellization phenomena of surface active promazine hydrochloride (PMZ) drug with cationic hydrotropes (para‐toluidine hydrochloride and ortho‐toluidine hydrochloride) in absence and occurrence of 50 mmol kg−1 NaCl at five different temperature (293.15–313.15 K). PMZ is an amphiphilic phenothiazine drug and employed for the cure of mania and schizophrenia. Conductometry measurement was employed to gain a detailed picture of the interactions between drug and hydrotrope molecules. The experimental data were analyzed according to different mixing models within the outline of the pseudophase separation model. The evaluated values of critical micelle concentration (cmc) were found to be inferior than cmcid values signifying attractive interactions involving the both components in the solutions. NaCl further reduces the cmc of pure amphiphiles and their mixed systems as a result of screening of the electrostatic repulsion between the polar head groups. The micellar mole fractions (X1) of hydrotropes evaluated by various proposed models were constantly more than ideal values ( ) signifying high involvements of hydrotrope in mixed micelles. Activity coefficients ( and ) were always below one in all cases signifying synergism in mixed micelles. Thermodynamic parameters favor the process of micellization which is found to be entropy driven. The negative values of free energies of mixing demonstrated the stability of the mixed systems of drug and hydrotrope. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
194.
Three different long‐chain branch (LCB) formation mechanisms for ethylene polymerization with metallocenes in solution polymerization semi‐batch and continuous stirred‐tank reactors are modeled to predict the microstructure of the resulting polymer. The three mechanisms are terminal branching, C–H bond activation, and intramolecular random incorporation. Selected polymerization parameters are varied to observe how each mechanism affects polymer microstructure. Increasing the ethylene concentration during semi‐batch polymerization reduces the LCB frequency of polymers made with the terminal branching and intramolecular mechanisms, but has no effect on those made with the C–H bond activation mechanism, which disagrees with most previous data published in the literature. The intramolecular mechanism predicts that LCB frequencies hardly depend on polymerization time or ethylene conversion, which also disagrees with the published experimental data for these systems. For continuous polymerization reactors, experimental data relating polydispersity to LCB frequency can be well described with the terminal branching mechanism, but both C–H bond activation and intramolecular models fail to describe this experimental relationship. Therefore, detailed simulations confirm that the terminal branching mechanism is indeed the most likely mechanism for LCB formation when ethylene is polymerized with single‐site coordination catalysts such as metallocenes in solution polymerization reactors. 相似文献
195.
Susan Najari Mohammad Jafarzadeh Kiumars Bahrami 《Journal of heterocyclic chemistry》2019,56(10):2853-2865
A zirconium‐based metal–organic framework, UiO‐66‐NH2, modified by melamine (Mlm) was used as a support for CuO nanoparticles (NPs). Melamine offered a platform for uniform and homogeneous distribution of NPs on the surface of the frameworks and made a strong bonding to the NPs to avoid undesirable leaching. UiO‐66‐NH2‐Mlm/CuO NPs were used for the Buchwald–Hartwig C–N cross‐coupling reaction to synthesize arylated anilines from phenyl iodide, bromide, and chloride and primary and secondary amines in DMF at 110°C. The catalyst was also employed for the synthesis of 2‐substituted benzimidazole derivatives from various aromatic aldehydes and o‐phenylenediamine in the absence of an oxidant in EtOH at room temperature. The catalyst was recyclable and reusable for several times and exhibited good stability (examined by BET, XRD, and SEM–EDX) in reaction conditions. 相似文献
196.
Sajad Saberi Sarmoor S. Jafar Hoseini Roghayeh Hashemi Fath Mahmoud Roushani Mehrangiz Bahrami 《应用有机金属化学》2018,32(1)
PtSnZn nanosheet thin film with stable and high activity towards methanol electro‐oxidation was synthesized via a simple reduction of organometallic precursors including [PtCl2(cod)] (cod = cis,cis‐1,5‐cyclooctadiene) and [Sn(CH3)4] complexes, in the presence of [Zn(acac)2] (acac = acetylacetonate) complex at toluene–water interface. Catalytic activities of PtSnZn nanosheets were investigated in the p‐nitrophenol (p‐Nip) reduction and methanol oxidation reactions. The obtained results demonstrate that PtSnZn nanosheets exhibit a good electrocatalytic performance for methanol oxidation reaction, the catalytic activity of the PtSnZn nanosheets being at least 3.5 times higher than that of Pt nanoparticle thin film. Also, the apparent rate constant obtained for p‐Nip reduction with the PtSnZn nanosheets is at least 2.3 times higher than that for Pt nanoparticle thin film due to the appropriate interaction between platinum, tin and zinc metals and geometric properties of PtSnZn nanosheet thin film. Nanosheets are highly favourable for superior catalytic performances due to their geometric properties. A facile and efficient route was used to synthesize trimetallic alloy thin film at oil–water interface. 相似文献
197.
Maryam Hussein Abdulameer;Ali B. M. Ali;Ahmed K. Nemah;Prakash Kanjariya;Asha Rajiv;Mohit Agarwal;Parjinder Kaur;Abdulrahman A. Almehizia; 《International journal of quantum chemistry》2024,124(22):e27505
The Pὃschl–Teller potential is a molecular potential energy function that has only been reported for bound state. This Pὃschl–Teller potential is a good representation of many molecules and has not been examined for any thermodynamic property irrespective of its fitness for molecular study. In this study, the molar entropy of four molecules (Pbr, BBr, CsCl, and CsO molecules) is calculated via the molar partition function. The predicted results are compared with the experimental data recorded in the National Institute of Standards and Technology (NIST) database. It is noted that the predicted values for the studied molecules perfectly agree with the experimental results with the following average absolute percentage deviation, PBr is 0.0158%, BBr is 0.0053%, CsCl is 0.0020%, and CsO is 0.0052%. The present model reproduces better results for CsCl and CsO molecules compared to the shifted Tietz–Wei potential and improved Tietz-oscillator previously reported whose average absolute percentage deviation are 0.361% and 0.284% for CsCl and 0.272% and 0.228% for CsO, respectively. 相似文献
198.
199.
Mai E. Hussein Osama G. Mohamed Ahlam M. El-Fishawy Hesham I. El-Askary Amira S. El-Senousy Ahmed A. El-Beih Eman S. Nossier Ahmed M. Naglah Abdulrahman A. Almehizia Ashootosh Tripathi Ahmed A. Hamed 《Molecules (Basel, Switzerland)》2022,27(3)
The rapid spread of bacterial infection caused by Staphylococcus aureus has become a problem to public health despite the presence of past trials devoted to controlling the infection. Thus, the current study aimed to explore the chemical composition of the extract of endophytic fungus Aspergillus fumigatus, isolated from Albizia lucidior leaves, and investigate the antimicrobial activity of isolated metabolites and their probable mode of actions. The chemical investigation of the fungal extract via UPLC/MS/MS led to the identification of at least forty-two metabolites, as well as the isolation and complete characterization of eight reported metabolites. The antibacterial activities of isolated metabolites were assessed against S. aureus using agar disc diffusion and microplate dilution methods. Compounds ergosterol, helvolic acid and monomethyl sulochrin-4-sulphate showed minimal inhibitory concentration (MIC) values of 15.63, 1.95 and 3.90 µg/mL, respectively, compared to ciprofloxacin. We also report the inhibitory activity of the fungal extract on DNA gyrase and topoisomerase IV, which led us to perform molecular docking using the three most active compounds isolated from the extract against both enzymes. These active compounds had the required structural features for S. aureus DNA gyrase and topoisomerase IV inhibition, evidenced via molecular docking. 相似文献
200.
Uday M. Muddapur Sultan Alshehri Mohammed M. Ghoneim Mater H. Mahnashi Mohammed Abdulrahman Alshahrani Aejaz Abdullatif Khan S. M. Shakeel Iqubal Amal Bahafi Sunil S. More Ibrahim Ahmed Shaikh Basheerahmed Abdulaziz Mannasaheb Noordin Othman Muazzam Sheriff Maqbul Mohammad Zaki Ahmad 《Molecules (Basel, Switzerland)》2022,27(4)
Bionanotechnology is a branch of science that has revolutionized modern science and technology. Nanomaterials, especially noble metals, have attracted researchers due to their size and application in different branches of sciences that benefit humanity. Metal nanoparticles can be synthesized using green methods, which are good for the environment, economically viable, and facilitate synthesis. Due to their size and form, gold nanoparticles have become significant. Plant materials are of particular interest in the synthesis and manufacture of theranostic gold nanoparticles (NPs), which have been generated using various materials. On the other hand, chemically produced nanoparticles have several drawbacks in terms of cost, toxicity, and effectiveness. A plant-mediated integration of metallic nanoparticles has been developed in the field of nanotechnology to overcome the drawbacks of traditional synthesis, such as physical and synthetic strategies. Nanomaterials′ tunable features make them sophisticated tools in the biomedical platform, especially for developing new diagnostics and therapeutics for malignancy, neurodegenerative, and other chronic disorders. Therefore, this review outlines the theranostic approach, the different plant materials utilized in theranostic applications, and future directions based on current breakthroughs in these fields. 相似文献