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Silver nanoparticles (AgNPs) have attracted great interest due to their applications in various areas. In the present study ecofriendly biosynthesis of extracellular silver nanoparticles was carried out using Candida utilis NCIM 3469. Characterization of synthesized AgNPs was done by UV–visible spectroscopy, Scanning electron microscopy and antibacterial activity. AgNPs are found spherical in shape with size in the range of 20–80 nm. AgNPs showed antibacterial activity against pathogenic organisms such as Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. The SEM analysis confirms the antibacterial activity of Ag nanoparticles due to damage of cytoplasmic membrane. AgNPs synthesized by C. utilis could be applicable in the development of antibacterial water filters for treatment of water.

This study aimed to explore the changes in morphological, physiological and biochemical characteristics of lettuce (Lactuca sativa L.) in response to salt stress when grown using hydroponic techniques. The seedlings were subjected to five different concentrations (0 mM, 50 mM, 100 mM, 150 mM, and 200 mM) of NaCl for three weeks. During the salt stress, morphological properties (shoot length, root length, total plant weight, leaf number) were measured in every week. After 21 days of salt stress, physiological properties (water content and relative water content) and biochemical properties (proline, protein, phenol, reducing and non-reducing sugar content) were measured. Morphological and physiological properties were found decreased gradually with increasing salt concentrations. Biochemical properties such as proline and protein content increased remarkably, and total phenol content decreased gradually with increasing salt concentrations. Reducing sugar accumulation was higher in all treatments except 50 mM in comparison to control. Non-reducing sugar accumulation was decreased in 100 mM and 200 mM treatment, similar in 150 mM treatment, and increased in 50 mM treatment when compared to control. These findings render lettuce a salt-sensitive plant at higher salt concentration. However, changes in characteristics were realistic up to 50 mM salt concentration.

Alzheimer's disease is characterized by the presence of extracellular deposition of amyloid beta (Aβ) peptides.

Caffeine based N‐heterocyclic carbene (NHC)‐silver complex anchored on magnetic nanoparticles (MNP‐Caff‐NHC@Ag complex) has been prepared by covalent grafting of caffeine on the surface of chloro‐functionalized Fe3O4 magnetic nanoparticles followed by complexation with silver (I) acetate. The MNP‐Caff‐NHC@Ag complex has been characterized by Fourier transform infrared (FT‐IR) spectroscopy, energy‐dispersive X‐ray (EDX) spectroscopy, transmission electron microscopy (TEM), X‐ray diffraction (XRD), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM) analysis. The MNP‐Caff‐NHC@Ag complex displayed significant in vitro anticancer activity against human hepatocarcinoma HepG2 cell line and antibacterial activity against Escherichia coli (NCIM‐2832), Staphylococcus aureus (NCIM‐2654) and Bacillus cereus (NCIM‐2703). The hyperthermia studies revealed that MNP‐Caff‐NHC@Ag complex achieved good therapeutic temperature (47 °C) under physiological safe range of field and frequency thereby forecasting potential applications as heating mediators in magnetic hyperthermia for selectively killing of cancer cells.

The pathological hallmark of Alzheimer's disease is the accumulation of Aβ peptides in human brains. These Aβ peptides can be degraded by several enzymes such as hACE, hECE, hIDE and cathepsin B. Out of which cathepsin B also belongs to the papain super family and has been found in human brains, it has a role in Aβ peptide degradation through limited proteolysis. The Aβ concentrations are maintained properly by its production and clearance via receptor-mediated cellular uptake and direct enzymatic degradation. However, the reduced production of Aβ degrading enzymes as well as their Aβ degrading activity in human brains initiate the process of accumulation of Aβ peptides. So it becomes essential to investigate the molecular interactions involved in the process of Aβ degradation in detail at the atomic level. Hence, homology modeling, molecular docking and molecular dynamics simulation techniques have been used to explore the possible role of cathepsin B from Hordeum vulgare in the degradation of amyloid beta (Aβ) peptides. The homology model of cathepsin B from Hordeum vulgare shows good similarity with human cathepsin B. Molecular docking and MD simulation results revealed that the active site residues Cys32, HIS112, HIS113 are involved in the catalytic activity of cathepsin B. The sulfhydryl group of the Cys32 residue of cathepsin B from Hordeum vulgare cleaves the Aβ peptide from the carboxylic end of Glu11. Hence, this structural study might be helpful in designing alternative strategies for the treatment of AD.

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