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A new approach towards the design of folic acid conjugated magnetic nanoparticles for enhancing their site specific intracellular uptake against a folate receptor overexpressing cancer cells is reported. Magnetite nanoparticles were prepared by coprecipitation from an Fe3+ and Fe2+ solution followed by surface modification with 2-carboxyethyl phosphonic acid to form carboxyl group terminated nanoparticles. Then folic acid and fluorescein isothiocyanate (FITC) were conjugated with carboxylic acid functionalized magnetite nanoparticles using 2,2′-(ethylenedioxy)-bis-ethylamine. These folate-conjugated nanoparticles were characterized in terms of their size by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Surface functional groups and surface composition were analyzed by Fourier transform infrared (FTIR) spectroscopy and x-ray photoelectron spectroscopy (XPS), respectively. Vibration sample magnetometry (VSM) measurements showed the superparamagnetic nature of the particles at room temperature. Folate-conjugated magnetic nanoparticles are noncytotoxic and receptor mediated internalization by HeLa and B16 melanoma F0 cancer cells was confirmed by flow cytometry and confocal microscopy.

The development of smart targeted nanoparticle that can deliver drugs to direct cancer cells, introduces better efficacy and lower toxicity for treatment. We report the development and characterizations of pH-sensitive carboxymethyl chitosan modified folic acid nanoparticles and manifest their feasibility as an effective targeted drug delivery vehicle. The nanoparticles have been synthesized from carboxymethyl chitosan with covalently bonded bifunctional 2,2'-(ethylenedioxy)-bis-(ethylamine) (EDBE) through the conjugation with folic acid. The conjugation has been analyzed by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The resultant nanoparticles with an average size less then 200 nm measured by dynamic light scattering and transmission electron microscopy. Confocal microscopy and flow cytometric analysis have revealed that folate-mediated targeting significantly enhances the cellular uptake of the nanoparticle and thus facilitates apoptosis of cancer cells (HeLa, B16F1). For the application of the nanoparticles as a drug carrier, Doxorubicin a potent anticancer drug has been loaded into the nanoparticles, with the drug loading amount and the drug release pattern observed.

The electrochemical reduction of oxygen to water and the evolution of oxygen from water are two important electrode reactions extensively studied for the development of electrochemical energy conversion and storage technologies based on oxygen electrocatalysis. The development of an inexpensive, highly active, and durable nonprecious-metal-based oxygen electrocatalyst is indispensable for emerging energy technologies, including anion exchange membrane fuel cells, metal-air batteries (MABs), water electrolyzers, etc. The activity of an oxygen electrocatalyst largely decides the overall energy storage performance of these devices. Although the catalytic activities of Pt and Ru/Ir-based catalysts toward an oxygen reduction reaction (ORR) and an oxygen evolution reaction (OER) are known, the high cost and lack of durability limit their extensive use for practical applications. This review article highlights the oxygen electrocatalytic activity of the emerging non-Pt and non-Ru/Ir oxygen electrocatalysts including transition-metal-based random alloys, intermetallics, metal-coordinated nitrogen-doped carbon (M–N–C), and transition metal phosphides, nitrides, etc., for the development of an air-breathing electrode for aqueous primary and secondary zinc-air batteries (ZABs). Rational surface and chemical engineering of these electrocatalysts is required to achieve the desired oxygen electrocatalytic activity. The surface engineering increases the number of active sites, whereas the chemical engineering enhances the intrinsic activity of the catalyst. The encapsulation or integration of the active catalyst with undoped or heteroatom-doped carbon nanostructures affords an enhanced durability to the active catalyst. In many cases, the synergistic effect between the heteroatom-doped carbon matrix and the active catalyst plays an important role in controlling the catalytic activity. The ORR activity of these catalysts is evaluated in terms of onset potential, number of electrons transferred, limiting current density, and durability. The bifunctional oxygen electrocatalytic activity and ZAB performance, on the other hand, are measured in terms of potential gap between the ORR and OER, ΔE = E j10 OER – E 1/2 ORR, specific capacity, peak power density, open circuit voltage, voltaic efficiency, and charge–discharge cycling stability. The nonprecious metal electrocatalyst-based ZABs are very promising and they deliver high power density, specific capacity, and round-trip efficiency. The active site for oxygen electrocatalysis and challenges associated with carbon support is briefly addressed. Despite the considerable progress made with the emerging electrocatalysts in recent years, several issues are yet to be addressed to achieve the commercial potential of rechargeable ZAB for practical applications.

The growing demand for the renewable energy storage technologies stimulated the quest for efficient energy storage devices. In recent years, the rechargeable aqueous zinc-based battery technologies are emerging as a compelling alternative to the lithium-based batteries owing to safety, eco-friendliness, and cost-effectiveness. Among the zinc-based energy devices, rechargeable zinc-ion batteries (ZIBs) are drawing considerable attention. However, they are plagued with several issues, including cathode dissolution, dendrite formation, etc.. Despite several efforts in the recent past, ZIBs are still in their infant stages and have yet to reach the stage of large-scale production. Finding stable Zn 2 + intercalation cathode material with high operating voltage and long cycling stability as well as dendrite-free Zn anode is the main challenge in the develop-ment of efficient zinc-ion storage devices. This Review discusses the various strategies, in terms of the engineering of cathode, anode and electrolyte, adopted for improving the charge storage performance of ZIBs and highlights the recent ZIB technological innovations. A brief account on the history of zinc-based devices and various cathode materials tested for ZIB fabrication in the last five years are also included. The main focus of this Review is to provide a detailed account on the rational engineering of the electrodes, electrolytes, and separators for improving the charge storage performance with a future perspective to achieving high energy density and long cycling stability and large-scale production for practical application.

Blastocystis hominis has been reclassified as a protozoan parasite. Its role as a human pathogen is somewhat controversial. There has been a dramatic increase in the frequency of B. hominis infection in association with diarrhea especially in immunocompromised hosts like AIDS patients, travelers, homosexuals, day care children, animal handlers especially zoo keepers, etc. Recent reports suggest that B. hominis is an emerging pathogen; hence, we have undertaken this study to detect B. hominis from stool samples of patients attending our hospital. About 200 stool samples were tested by light microscopic examination, for observing wet mounts with saline and Lugol's iodine. Permanent staining of fecal smear by Gram's staining and modified acid fast staining was done. The stool sample which was microscopically positive for B. hominis was cultured on Lowenstein-Jensen's (LJ) medium. In one patient, the vacuolated form of B. hominis was observed in wet mount with saline preparation of stool sample. This was very clearly seen in wet mount with Lugol's iodine. In Gram's stained preparation, also the vacuolated form was observed. Detection of B. hominis was not possible by modified acid fast staining. B. hominis was also grown on LJ medium which is an egg-containing medium. Clinical microbiology laboratories should start screening of stool samples for B. hominis as it is an emerging pathogen.

Supramolecular colorless copper(I)-thiourea hydrogel (Cu-TU gel) has been made a mechanically strong functional hybrid material in graphene oxide (GO) framework.Mild heat treatment (85 ºC) of the hybrid material fetches black colored hierarchical copper sulfide decorated reduced graphene oxide nanosheets (CuS-rGO) through an obvious inhouse redox transformation reaction between Cu(I) and GO without any additive. The assynthesized CuS-rGO nanocomposite exhibits impressive peroxidase-like activity where oxidation of colorless 3, 3', 5, 5'-tetramethylbenzidine (TMB) to blue colored product is observed in solution phase with H 2 O 2 . Systematic control experiments suggest that strong covalent interaction between CuS and rGO synergistically enhances the catalytic activity of CuS-rGO in comparison to its individual counterparts. Furthermore, important biomolecule, dopamine has been found to selectively inhibit, in succession, the oxidizing action of H 2 O 2 for TMB oxidation reaction. Thus dopamine dependent successive inhibition reaction creates a one-pot reporter platform to sense dopamine down to 0.48 µM concentration level by UVvis spectrophotometry.