Doped zinc oxide nanoparticles: Synthesis, characterization and potential use in nanomedicine

Smart nanoparticles for medical applications have gathered considerable attention due to an improved biocompatibility and multifunctional properties useful in several applications, including advanced drug delivery systems, nanotheranostics and in vivo imaging. Among nanomaterials, zinc oxide nanoparticles (ZnO NPs) were deeply investigated due to their peculiar physical and chemical properties. The large surface to volume ratio, coupled with a reduced size, antimicrobial activity, photocatalytic and semiconducting properties, allowed the use of ZnO NPs as anticancer drugs in new generation physical therapies, nanoantibiotics and osteoinductive agents for bone tissue regeneration. However, ZnO NPs also show a limited stability in biological environments and unpredictable cytotoxic effects thereof. To overcome the abovementioned limitations and further extend the use of ZnO NPs in nanomedicine, doping seems to represent a promising solution. This review covers the main achievements in the use of doped ZnO NPs for nanomedicine applications. Sol-gel, as well as hydrothermal and combustion methods are largely employed to prepare ZnO NPs doped with rare earth and transition metal elements. For both dopant typologies, biomedical applications were demonstrated, such as enhanced antimicrobial activities and contrast imaging properties, along with an improved biocompatibility and stability of the colloidal ZnO NPs in biological media. The obtained results confirm that the doping of ZnO NPs represents a valuable tool to improve the corresponding biomedical properties with respect to the undoped counterpart, and also suggest that a new application of ZnO NPs in nanomedicine can be envisioned

PARTIAL PURIFICATION AND IMMUNO-BIOCHEMICAL CHARACTERISATION OF FERTILITY ASSOCIATED PROTEIN OF KARAN FRIES BULL SEMINAL PLASMA

The objective of the present study was detection, isolation, partial purification and immunobiochemical characterization of fertility associated protein in the seminal plasma of high prolific Karan fries bull. Seminal plasma of Karan Fries bull was partially purified by gel filtration chromatography and analyzed by 10% SDS-PAGE for their polypeptide profile. PAGE analysis revealed major band of 55 kDa, and 26 kDa. Hyperimmune serum was raised in rabbit against crude seminal plasma protein. Single precipitin line was observed in DID test when each of the partially purified 26 kDa and 55 kDa proteins were reacted with hyperimmune serum. These proteins were also found to be immunoreactive against hyperimmune serum in Western blot technique

Design of digitally controlled DC-DC boost converter for the operation in DC microgrid

Renewable energy sources (RESs) are becoming increasingly important day by day to tranquilize the world’s energy crisis and consume fossil fuels in the lower rung. A microgrid system that assimilates clean and green energy-based sources such as solar, wind, and biogas is acquiring much prominence over the conventional grid-based power systems in this day and age. For the up and running of the inexhaustible energy sources in the AC power network, numerous conversions of the power sources occur. In the process of conversion, some amount of power is lost, which minimizes conversion efficiency. However, with the increasing use of DC loads and Distributed Energy Resources (DERs), DC Microgrid could be more beneficial than the conventional AC power system by avoiding several types of drawbacks. This paper demonstrates an efficient system of digitally controlled boost converter for the parallel operation in DC microgrid. Here, the converter of 2.5kW 400V is designed and implemented to validate its functioning in a Microgrid. The whole system has been simulated in MATLAB with an input voltage range of 220–380 V. It has been found that the designed converter can maintain the desired output voltage in the DC Busbar at and around 400 V. Finally, some simulation results have been presented to analyze the converter's operational characteristics and effectiveness in the practical domain

BOVINE PLASMA FIBRINOGEN AS MARKER IN CLINICAL AND SUB-CLINICAL MASTITIS

Plasma samples were collected from healthy as well as clinical and sub-clinical mastitis affected cows from Barasat, West Bengal, India. Plasma samples, after ammonium sulphate precipitation, were dialyzed against several changes of PBS (pH 7.2) to remove the excess ammonium sulphate. Then plasma fibrinogens were purified by gel filtration chromatography on Sephacryl S-200 HR. SDS-PAGE (10%) of purified fibrinogen from plasma of healthy cow revealed polypeptide bands of 74, 67 and 57 kDa which represent the α (alpha), β (beta) and γ (gamma)- chains respectively. On the other hand, purified fibrinogen from plasma of sub-clinical and clinical mastitis affected cow revealed polypeptide bands of 73 (α-chain), 68 kDa (β-chain) and 72 (γ-chain), 68 kDa (β-chain) respectively. The SDS-PAGE analysis showed the absence of gamma (γ)- chain of fibrinogen in both the samples of sub-clinical and clinical mastitis positive cow. Single precipitin line was observed in double immunodiffusion test when purified fibrinogen from healthy, clinical and subclinical mastitis positive cows reacted with hyper immune sera raised in rabbit. No precipitin line was found against the normal control serum. These purified fibrinogens also showed cross reactivity against antibody raised in rabbit when analyzed by western blot technique

Size-dependent apoptotic activity of gold nanoparticles on osteosarcoma cells correlated with SERS signal

In the last decade, gold nanoparticles have emerged as promising agents for in vitro bio-sensing and in vivo cancer theranostics. However, different investigations have reported widely varying cytotoxicity and uptake efficiency of gold nanoparticles depending upon their size. Therefore, more extensive studies are needed to standardize these biological effects as a function of size on a particular cell line. In addition, to obtain robust confirmation on the correlation of a size to biological effect, thorough mechanistic study must also be performed. In this study, the size dependent biological activities of gold nanoparticles on osteosarcoma cells is investigated towards exploring their potential theranostic application in bone cancer, for which very scarce literature reports are available. Tris-assisted citrate based method was optimized to synthesize stable gold naoparticles of 40–60 nm sizes. Nanoparticles were characterized through UV–Vis spectroscopy, field emission scanning electron microscope (FESEM) and dynamic light scattering (DLS). Increasing concentrations of gold nanoparticles (AuNPs) of 46 nm size, enhanced the rate of reactive oxygen species (ROS)-induced apoptosis in MG63 cells by disrupting their mitochondrial membrane potential. Considerably higher cell death was observed for 46 and 60 nm AuNPs compared to 38 nm at all concentrations of 200, 400 and 800 ng/mL. Further, molecular signatures of cellular apoptosis under nanoparticle treatment were optically assessed through surface enhanced Raman scattering (SERS). A significant Raman enhancement in cancer cells under treatment of larger gold nanoparticles (46 and 60 nm) at fixed wavelength of 785 nm and laser power of 8.0 mW was evident. In corroboration with molecular biology techniques, SERS observation confirmed the size-dependent apoptotic phenomena in osteosarcoma cells under treatment of gold nanoparticles. Study demonstrates a facile, non-active targeting approach for detection of size-dependent AuNP-induced apoptosis in osteosarcoma cells through label-free SERS method

Some studies of solar flare effects on the propagation of sferics and a transmitted signal

260-265Apart from diurnal and seasonal variations, integrated field intensity of sferics (IFIS) exhibits characteristic variations in relation to various geophysical and solar events like geomagnetic storms, meteor showers, solar X-ray flares and solar radio emission. Continuous monitoring of IFIS at frequencies 1, 3, 6, 9 and 12 kHz from Agartala (latitude 23ºN) are being made over the last several years. The analyses of some preliminary observations in relation to solar flares are reported in the paper. Solar flare effects on the propagation of transmitted signals at 16.3 kHz recorded in Kolkata (latitude 22.56ºN) during November 2004 have also been presente