Facile immobilization of potassium-copper hexacyanoferrate nanoparticles using a room-temperature ionic liquid as an ionic binder and its application towards BHA determination

In this paper, a facile immobilization of copper hexacyanoferrate nanoparticles (CuHCFNP) on a paraffin wax-impregnated graphite electrode (PIGE) was carried out using the room-temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF₄) as an ionic binder. The characteristics of the CuHCFNP/EMIMBF₄ gel-modified electrode were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques, and the modified electrode morphology was also characterized using field emission scanning electron microscopy (FESEM). The electrocatalytic behavior of butylated hydroxyl anisole (BHA) at the modified electrode has been investigated in 0.1 M KNO₃ in static and dynamic conditions. Under the optimum conditions, the oxidation peak current was proportional to the BHA concentration in the range from 1.5 to 1000 μM with a detection limit of 0.5 μM (S/N = 3). The proposed method was applied to determine BHA content in real samples with satisfactory results.

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Synthesis and characterization of immobilized activated carbon doped TiO2 thin films

Immobilized activated carbon doped TiO₂ thin films were prepared by sol–gel dip coating method by using Titanium IV isopropoxide as a precursor. Aim of our work is to synthesize and investigate the structural, surface morphology and optical properties of the synthesized thin film. X-ray diffraction pattern reveals that the crystallinity of the film increases with increase in temperature. Also, the structural parameters such as particle size, microstrain and dislocation density have been calculated. The formation of nanosphere of diameter ranging from 300 nm to 500 nm has been confirmed by Scanning electron microscope. Photocatalytic active large optical band gap at 3.75 eV was found by using UV–visible sspectrum.     

Scaffold tailoring by a newly detected Pictet-Spenglerase activity of strictosidine synthase: from the common tryptoline skeleton to the rare piperazino-indole framework

The Pictet-Spenglerase strictosidine synthase (STR1) has been recognized as a key enzyme in the biosynthesis of some 2000 indole alkaloids in plants, some with high therapeutic value. In this study, a novel function of STR1 has been detected which allows for the first time a simple enzymatic synthesis of the strictosidine analogue 3 harboring the piperazino[1,2-a]indole (PI) scaffold and to switch from the common tryptoline (hydrogenated carboline) to the rare PI skeleton. Insight into the reaction is provided by X-ray crystal analysis and modeling of STR1 ligand complexes. STR1 presently provides exclusively access to 3 and can act as a source to generate by chemoenzymatic approaches libraries of this novel class of alkaloids which may have new biological activities. Synthetic or natural monoterpenoid alkaloids with the PI core have not been reported before.     

Experimental investigations on plasticized PMMA/PVA polymer blend electrolytes

Blend based polymer electrolytes composed of poly (methyl methacrylate) (PMMA), poly(vinylalcohol) (PVA) and LiClO₄ are prepared using solvent casting technique. The polymer films are characterized by XRD and FTIR studies to determine the molecular environment for the conducting ions. These polymer films have been investigated in terms of ionic conductivity using the results of impedance studies. The influence of the blend composition on the electrochemical behaviour is also discussed. The highest room temperature conductivity obtained for the film consisting of PMMA, PVA, LiClO₄ and DMP is 0.06×10⁻³ S/cm at 303 K. The PMMA-PVA blend based polymer electrolytes look very desirable and promising for lithium battery applications.     

Rubus Capped Zinc Oxide Nanoparticles Induce Apoptosis in MCF-7 Breast Cancer Cells

Rubus fairholmianus (RF) has widely been used to treat various ailments, including pain, diabetes, and cancer. Zinc oxide nanoparticles (ZnO NPs) have drawn attention in modern healthcare applications. Hence, we designed this study to synthesize zinc oxide (ZnO) nanoparticles using R. fairholmianus root extract to investigate its synergistic cytotoxic effect on MCF-7 cells and explore the possible cell death mechanism. ZnO NPs were synthesized via green synthesis using R. fairholmianus root extract, and the effect on MCF-7 cells was determined by looking at cellular morphology, proliferation, cytotoxicity, apoptosis, and reactive oxygen species (ROS). The results showed that cellular proliferation was reduced following treatment with R. fairholmianus capped zinc oxide nanoparticles (RFZnO NPs), while cytotoxicity and ROS were increased. There was also an increase in apoptosis as indicated by the significant increase in cytoplasmic cytochrome c and caspase 3/7 (markers of apoptosis), as well as increased levels of pro-apoptotic proteins (p53, Bax) and decreased levels of anti-apoptotic protein (Bcl-2). In conclusion, these results showed that RFZnO NPs induce apoptosis in breast cancer cells via a mitochondria-mediated caspase-dependent apoptotic pathway and suggest the use of acetone root extract of R. fairholmianus for the treatment of cancer-related ailments.     

One-pot synthesis of [2+2]-helicate-like macrocycle and 2+4-μ4-oxo tetranuclear open frame complexes: Chiroptical properties and asymmetric oxidative coupling of 2-naphthols

Synthesis of binuclear Cu(II) terminally closed [ 2+2 ]- double-stranded helicate-like macrocycles 1, 1′ , 1″ , 2 , 2′ , 2″ and 2+4- μ₄-oxo tetranuclear open frame complexes 3 , 3′ , 3″ , 4 , 4′ , 4″ are established. Adapting one-pot self-assembly technique from simple three components systems: 1,1′-binaphthyl-2,2′-diamine, 4-methyl-2,6-diformyl phenol and cupric salts, the helicate-like [ 2+2 ]- macrocyclic complexes 1–1″, 2–2″ and 2+4- μ₄-oxo tetranuclear complexes 3–3″ , 4–4″ were obtained by appropriately altering the reaction condition such as temperature and subcomponent ratio. Density Functional Theory (DFT) calculations were carried out for understanding the structural geometries, intermediates involved in the diverse formation of [ 2+2 ] and 2+4 frameworks. The single crystal X-ray structures obtained for 1′ , 2 and 3 confirms the self-assembly process in line with DFT. This detailed analysis tempted us to derive a plausible mechanism for this long standing challenge in the synthesis of such macrocycles using 1,1′-binaphthyl-2,2′-diamine (BNDA) and aromatic aldehyde. The chiroptical properties of enantiopure complexes and their catalytic applications in asymmetric oxidative coupling of 2-naphthol to chiral 1,1’-Bi-2-naphthol (BINOL) achieved in good yield and ee were discussed.     

Constrained melting of graphene-based phase change nanocomposites inside a sphere

Journal of Thermal Analysis and Calorimetry - In the present work, the melting behavior of a fatty acid-based phase change material (PCM) with the addition of functionalized graphene nanoplatelets...     

Effect of thermostatic expansion valve tuning on the performance enhancement and environmental impact of a mobile air conditioning system

Journal of Thermal Analysis and Calorimetry - In this work, the performance enhancement of a HFO-1234yf mobile air conditioning (MAC) system with a suction/liquid line heat exchanger (SLHX) was...