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Dengue fever (DF) or dengue haemorrhagic fever (DHF) has not previously been reported in Coimbatore and Erode districts in Tamil Nadu in India. In 1998, 20 hospitalized cases of fever tested positive for dengue virus IgM and/or IgG antibodies. All of them had dengue-compatible illness, and at least four had DHF. Two of them died. Sixteen cases were below 10 years of age. The cases were scattered in 15 distantly located villages and 5 urban localities that had a high Aedes aegypti population. Although the incidence of dengue-like illness has not increased recently, almost 89% (95/107) of samples from healthy persons in the community tested positive for dengue IgG antibodies. The study showed that dengue has been endemic in the area, but was not suspected earlier. A strong laboratory-based surveillance system is essential to monitor and control DF/DHF.

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Electrocyclic ring opening (ERO) reaction of 2H-Oxete (oxetene) has been carried out computationally in the gas phase and ring opening barrier has been computed. When comparing the ERO reaction of oxetene with the parent hydrocarbon (cyclobutene), the ring opening of cyclobutene is found to exhibit pericyclic behavior while oxetene shows mild pseudopericyclic nature. Computation of the nucleus-independent chemical shift (NICS) of oxetene adds evidence for pseudopericyclic behavior of oxetene. By locking of lone pair of electrons by hydrogen bonding, it is seen that the pseudopericyclic nature of the ring opening of oxetene is converted into a pericyclic one. CASSCF(5,6)/6-311+G** computation was carried out to understand the extent of involvement of lone pair of electrons during the course of the reaction. CR-CCSD(T)/6-311+G** computation was performed to assess the energies of the reactant, transition state and the product more accurately.

Synthesis and characterization of N-(phenylC-NMR and Mass Spectroscopy. The final compounds were tested anti-microbial culture study. In the antibacterial and anti-fungal study the compounds 1-N-(phenyl (thiomorpholino) methyl) carbamide (TBC) shows very good activity against Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli and N-(phenyl (thiomorpholino) methyl) acetamide (TBA) shows very good activity against Penicillium species, Candida albicans and Aspergillus niger, compare to other Mannich bases. Small reaction time, eco-friendly products, high yield and very good microbial activity are the main advantages of this procedure which makes it more economical than the other conventional methods.

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A benzalkonium chloride (BKC) catalyzed oxidation of pentaammine cobalt(III) complexes of both bound and unbound α-hydroxy acids by tributylammonium chlorochromate (TriBACC) has been studied. Perchloric acid is adapted as a medium and the oxidative kinetics was contrived spectrophotometrically at room temperature. Rate of TriBACC oxidation is carried out at pseudo-first order conditions and rate constant was calculated. Absence of salt effect is observed on increasing NaClO4 concentration. Abatement in UV-visible absorbance at 503 nm for Co(III) complex confirms to nearly 100 % of initial absorbance. The complex2+ shows inner sphere mechanism and induced electron transfer reaction yields 100 % Co(II). The product formed in this oxidation was analyzed and polymerization test was carried out. Comparative study of rate of TriBACC oxidation in presence of benzalkonium chloride is listed out.

Cr(VI) is removed efficiently from aqueous solution using Chitosan made films as the adsorbent. The efficiency of free Chitosan films is compared with the Chitosan-Silica and ChitosanCarbon, which are reinforced with biogenic Silica and Carbon obtained from Panicum miliare husk ashes, respectively. All the films were prepared by simple ageing method and swelling index was determined for all the three adsorbents independently. Adsorption studies of Cr(VI) heavy metal were carried out by varying pH, temperature, initial concentration of the adsorbate and quantity of adsorbent. On the otherhand, Cr(VI) was removed from the solution by Chitosan-Silica film better than free Chitosan and Chitosan-Carbon films. The optimum pH was found to be 3.0 and optimum temperature was 30°C. Thermodynamic, equilibrium and kinetic studies were carried out for all the three adsorbents, independently. Langmuir adsorption isotherm and Pseudo First Order kinetics were followed for the adsorption process. Concentration of metal ions was determined using a spectrophotometer. Oxidation states of the adsorbed Cr were determined by ESR. It was found that Chitosan-Silica film reduced Cr(VI) to Cr(III) almost completely in the aqueous solution.