Synthesis, characterization and effects of citric acid and PVA on magnetic properties of CoFe2O4

Cobalt ferrite (CoFe2O4) particles were synthesized by sol-gel method using metal nitrates, citric acid (CA) and polyvinyl alcohol (PVA). X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), thermogravimetry/differential scanning calorimetry analysis and vibrating sample magnetometer were used to study the structural, thermal and magnetic properties of the CoFe2O4 powder. XRD results indicate that the resultant particles have crystalline, pure single phase spinel structure. From HR-SEM images, a systematic decrease in particle size is observed with an increase in PVA concentration, along with addition of CA. CA at various concentrations of PVA significantly enhance the magnetic properties of the materials

Green synthesis of silver nanoparticle using goniothalamus wightii on graphene oxide nanocomposite for effective voltammetric determination of metronidazole

Graphene oxide (GO) has piqued the interest of both academia and industry owing to its polar and two-dimensional (2D) layered structure. Antibiotic concentrations can be detected with advanced GO composites to reduce the risk of bacterial resistance, which can be done with electrochemical sensors. Herein, we have developed an eco-friendly synthesis approach, one-pot strategy towards Goniothalamus wightii biomass-derived solution preparation of Ag nanoparticle-decorated graphene oxide (GO@AgNPs) composites. As- synthesized GO@AgNPs nanocomposites were analyzed using various analytical tools including Raman, X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). The Metronidazole (MIZ) determination was then investigated using cycle volumetric and amperometric (i-t) techniques by the GO@AgNPs composites. Prepared composites exhibit a wide-linear range of 0.09 μM to 4.594 mM, low detection limit of 69 nM and a limit of quantification detection of 786 nM. Furthermore, the practical applicability of the prepared GO@AgNPs nanocomposites were examined in pharmaceutical drug Flagyl (500 mg) with satisfactory recovery results

Manglicolous fungi from atolls of Maldives, Indian Ocean

141-142Thirty nine species represented by 29 species of Ascomycetes, 2 of Basidiomycetes and 8 of Deuteromycetes were collected from partially submerged and submerged, dead and decayed parts of 5 mangrove species. The dominant species were Dactylospora haliotrepha, Lineolata rhizophorae, Lophiostoma mangrovei, Massarina thalassiae and Verruculina enalia. The maximum number of fungal species were recorded on Rhizophora mucronata

Risk factors of tuberculosis (TB) among homeless population in Chennai city

Background: Tuberculosis (TB) is a major concern among high-risk populations such as the homeless. Tuberculosis (TB) is a major public health problem. The Chennai City has a large population of homeless persons and caregivers and is estimated to be the largest TB-endemic area in the intermediate-prevalence country, India. However, there have been few studies of homeless persons and caregivers. The objective of this study to assess the prevalence and risk factors for pulmonary TB among homeless population around Chennai. Methods: We conducted a cross-sectional study for screening TB symptoms using questionnaire. The study participants were recruited from 15 zones, which included 47-night shelters around Chennai under the control of the Chennai City in Tamil Nadu. Data was collected from homeless people who were living in night shelters in the northern, central, and southern regions of Chennai City. Results: Complete responses were available from 484 individuals (263 homeless persons and 173 caregivers). Four active TB cases (1.5%) among homeless persons were found, while there were no cases among caregivers

Arsenic content in certain marine brown algae and mangroves from Goa coast

283-285Arsenic has been estimated in 7 species each of brown algae and mangroves, including different parts of Sargassum cinereun. Arsenic is more concentrated in brown algae [concentration/factor(CF) range 1.5 - 7 x 10(3)] as compared to mangroves (CF < 1). In brown algae organic As is accounted for about 75-90% of total, but in S. cinereum and Sphacelaria furcigera about 50-60% inorganic As is noted. Basal thallus and reproductive organs of S. cinereum have higher concentration of total and organic As than active photosynthetic portions. However, holdfast accumulates lesser As but its organic As is high (80%). Arsenic in younger leaves of mangroves is marginally more (0.23 mg.kg-1 dry wt.) than that of mature and yellow leaves (0.16 mg. kg-1)

Nanostructured titanium surfaces exhibit recalcitrance towards Staphylococcus epidermidis biofilm formation

Titanium-based implants are ubiquitous in the healthcare industries and often suffer from bacterial attachment which results in infections. An innovative method of reducing bacterial growth is to employ nanostructures on implant materials that cause contact-dependent cell death by mechanical rupture of bacterial cell membranes. To achieve this, we synthesized nanostructures with different architectures on titanium surfaces using hydrothermal treatment processes and then examined the growth of Staphylococcus epidermidis on these surfaces. The structure obtained after a two-hour hydrothermal treatment (referred to as spear-type) showed the least bacterial attachment at short times but over a period of 6 days tended to support the formation of thick biofilms. By contrast, the structure obtained after a three-hour hydrothermal treatment (referred to as pocket-type) was found to delay biofilm formation up to 6 days and killed 47% of the initially attached bacteria by penetrating or compressing the bacteria in between the network of intertwined nano-spears. The results point to the efficacy of pocket-type nanostructure in increasing the killing rate of individual bacteria and potentially delaying longer-term biofilm formation