Pt(II) complexes immobilized on polymer‐modified magnetic carbon nanotubes as a new platinum drug delivery system

We combine nanotechnology and chemical synthesis to create a novel multifunctional platinum drug delivery vehicle based on magnetic carbon nanotubes (multiwall carbon nanotubes/Fe₃O₄@poly(citric acid)/cis‐[(Pt(1,7‐phenanthroline)(DMSO)Cl₂)]‐b‐poly(ethylene glycol) (MCNTs/FO@PC/Pt(II)‐b‐PEG)) for targeted cancer therapy. MCNTs/FO@PC/Pt(II)‐b‐PEG was conveniently prepared by conjugating cis‐[Pt(1,7‐phenanthroline)(DMSO)Cl₂] complex to MCNTs/FO@PC‐b‐PEG via strong hydrogen‐bonding interactions. In comparison with free cisplatin and Pt(II) complex, MCNTs/FO@PC/Pt(II)‐b‐PEG shows higher solubility in aqueous solution and higher cytotoxicity towards human cervical cancer HeLa cells and human breast cancer MDA‐MB‐231 cells. In vitro release experiments revealed that the platinum drug‐loaded delivery system is relatively stable under physiological conditions (pH = 7.4 and 37 °C) but susceptible to acidic environments (pH = 5.6 and 37 °C) which would trigger the release of loaded drugs. Fluorescence microscopy studies revealed that this magnetic nanohybrid system possesses marked cell‐specific targeting in vitro in the presence of an external magnetic field. The results indicated that the prepared superparamagnetic MCNTs/FO@PC/Pt(II)‐b‐PEG nanohybrid system is a promising candidate for inhibiting the proliferation of cancer cells.     

Magnetically recoverable AlFe/Te nanocomposite as a new catalyst for the facile esterification reaction under neat conditions

In this work, a new Fe₃O₄/AlFe/Te nanocomposite was synthesized by a one‐step sol–gel method. The Fe₃O₄ magnetic nanoparticles (MNPs) were prepared and then mixed with aluminum telluride (Al₂Te₃) in an alkali medium to produce the desired catalyst. After characterization of the Fe₃O₄/AlFe/Te nanocomposite by SEM, TEM, EDS, XRD, and ICP analyses, it was used in the esterification reaction. This heterogeneous catalyst showed high catalytic activity in the esterification of commercially available carboxylic acids with various alcohols to produce the desired esters at high conversions under neat conditions. The Fe₃O₄/AlFe/Te nanocomposites were separated from the reaction mixture via an external magnet and re‐used 8 times without significant loss of catalytic activity.     

Rapid Determination of Simple Polyphenols in Grapes by LC Using a Monolithic Column

The development of a rapid, reliable and reproducible LC method for the determination and quantification of 13 polyphenols (gallic acid, protocatechuic aldehyde, gentisic acid, catechin, vanillinic acid, caffeic acid, vanillin, epicatechin, syringaldehyde, p-coumaric acid, ferulic acid, sinapic acid and resveratrol) in grapes and derived products is reported. The polyphenols were separated in less than 8 min. Employed was an RP-18e (100 mm × 4.6 mm) monolithic type column. A gradient method with the following solvents was utilised for the chromatographic separation: A: 90% water, 2% acetic acid in methanol, and B: 90% methanol, 2% acetic acid in water. Two detectors in series were employed: a UV–Vis detector and a fluorescence excitation/emission detector. Influence of temperature (15–40 °C) and solvent flow rate (2–5 mL min^?1) on the separation were studied, and 25 °C and 2.5 mL min^?1 were found to be the optimum conditions. The relative standard deviations of the resulting peak areas, for both intra- and inter- experiments, were less than 2.4 and 2.6%, respectively. Finally, the developed method has been utilised for the quantification of the polyphenols in real samples.     

Switched system modeling and robust steering control of the tail end phase in a hot strip mill

In this article, a robust steering control for the last phase of the rolling process in a hot strip mill is proposed. This phase, called tail end phase, may be modelled as a linear switched system. The switchings make the system unstable and the task of the tail end steering control consists in guaranteeing the safety of the industrial plant. The system involves a two time scales dynamics. Hence, the singular perturbation method is used in order to design the control law. The controller has to take into account the physical variations of the rolled products and an uncertainty in the switching time. Results concerning the ArcelorMittal hot strip mill of Eisenhüttenstadt are presented.     

Photoinduced,Direct C(sp2)−H Bond Azo Coupling of Imidazoheteroarenes and Imidazoanilines with Aryl Diazonium Salts Catalyzed by Eosin Y

Herein, a greener approach to the eosin Y-Na₂ catalyzed, C(sp²)−H bond azo coupling of imidazoheteroarene with aryl diazonium salts is described, under acid free conditions. This direct photoredox process resulted in the corresponding azo products in good to excellent yields. Besides, this new approach could also be applicable to anilines, which is a poorly reactive substrate by other methods. The main features of this reaction are that it provides high yields and is gram-scalable and applicable to biologically relevant imidazoheteroarenes and -anilines.     

Synthesis and characterization of Mn:CdS nanoflower thin films prepared by hydrothermal method for photocatalytic activity

Journal of Sol-Gel Science and Technology - Mn-CdS nanoflowers were successfully deposited using hydrothermal technique at 150 °C for 2 h. The effect of changing the dopant...