Observation on the morphological and gonadal aspects of Cladonema radiatum (Class: Hydrozoa) from Tuticorin Bay, Southeast coast of India.

Studies on the hydrozoan fauna (Phylum: Cnidaria; Class: Hydrozoa) of the Indian waters during the 20th century were few in number (Nagale and Apte, 2013a, b). They originated in the early 1900s (Annandale, 1907; Ritchie, 1910, Thornely, 1916, Gravely, 1927), focussing on the taxonomy of hydroids in the 1960s along the southern coast, including Lakshadweep and Andaman Islands (Mammen, 1963, 1965a, b) and in the 1980s along the northern coast (Venugopalan Wagh, 1986). Species of the hydrozoan family Cladonematidae (Anthoathecata; Capitata) include benthic, creeping and swimming hydroids comprising four genera viz., Cladonema, Eleutheria, Staurocladia and the nomen dubium Dendronema (Schuchert, 2021). Cladonema differs from other genera of Cladonematidae by the branched tentacles either with an adhesive structure or cnidocytes and having nematocysts in oral knobs (Ghory et al., 2020 Farias et al., 2020). The taxonomy of Cladonema is uncertain and species in the genus have undergone several rounds of grouping and splitting. Gershwin Zeidler (2008) gave a detailed account of 13 putative species of Cladonema. However, Schuchert (2021) considered six species to be valid viz., C. radiatum, C. californicum, C. myersi, C. novaezelandiae, C. pacificum and C. timmsii. Studies on the genus Cladonema from Indian waters are patchy, with a brief report of its occurrence among other hydroids (Sastry and Chandramohan, 1989; Santhakumari and Nair, 1999; Arun et al., 2018). Among these records from India, C. myersi was collected from an experimental aquarium with seawater from an unknown location (Prasad, 1961). The present study documents the occurrence and describes the morphology and gonadal features of Cladonema radiatum from Tuticorin Bay, Gulf of Mannar, Southeast coast of India.

Understanding the structural and chemical changes in vertical graphene nanowalls upon plasma nitrogen ion implantation.

Shallow plasma ion implantation is a versatile method for nitrogen incorporation in vertical graphene nanowalls (VGNs). However, the defects introduced by the process and the preference of nitrogen to occupy various locations in the 2D layered structure make the characterization complex. We have simplified the analysis of 2 kV nitrogen plasma ion implanted VGNs by correlating the binding energy of N1s electrons with the chemical state of nitrogen as lone-pair localized (N1), lone-pair de-localized (N2) and quaternary nitrogen (N3). This new approach helps to understand the electronic nature of implanted VGNs, based on the occupancy of structural locations by nitrogen. The C1s photoelectron spectra and G-peak intensity normalized comparison of the entire Raman spectra revealed large scale sp2C to sp3C conversion and generation of defects upon implantation. The increase in relative stiffness of implanted VGNs, as observed in atomic force acoustic microscopic studies, was correlated with the formation of graphitic CNx (N2), crosslinking of layers by nitrogen (N3) and interlayer sp3 carbon.

Aptamer-based label-free detection of PDGF using ruthenium(II) complex as luminescent probe.

We report a simple, cost-effective, and label-free detection method, consisting of a platelet-derived growth factor (PDGF) binding aptamer and hydrophobic Ru(II) complex as a sensor system for PDGF. The binding of PDGF with the aptamer results in the weakening of the aptamer-Ru(II) complex, monitored by luminescence signal. A substantial enhancement in the luminescence intensity of Ru(II) complex is observed in the presence of aptamer due to the hydrophobic interaction. Upon addition of PDGF, the luminescence intensity is decreased, due to the stronger interaction between the aptamer and PDGF resulting in the displacement of Ru(II) complex to the aqueous solution. Our assay can detect a target specifically in a complex medium such as the mixture of proteins, at a concentration of 0.8 pM.

Antioxidant and antibacterial studies of arylazopyrazoles and arylhydrazonopyrazolones containing coumarin moiety.

A series of novel 1-(4-methylcoumarinyl-7-oxyacetyl)-3,5-dimethyl-4(arylazo)pyrazoles and 1-(4-methylcoumarinyl-7-oxyacetyl)-3-methyl-4-(substituted phenyl) hydrazono-2-pyrazolin-5-ones were synthesised and evaluated for antibacterial and antioxidant activities. Compounds 3b, 3g, 5b, 5d and 5g showed good antibacterial activity and compound 5e was found to be the most active antioxidant in the series, and thus represent a new class of promising lead compounds.