Removal of Cd(II) from aqueous solutions using clarified sludge.

Clarified sludge is a major waste generating during steel making process. In India and in most industrial countries, the use of clarified sludge as a road ballast and land filter has had a very long history. In present study, clarified sludge has been characterized and used for the removal of Cd(II) from aqueous solutions. The effect of pH, adsorbent dosage, adsorbate concentration, contact time and temperature on adsorption process was studied in batch experiments. Kinetics data were best described by pseudo-second order model. The effective diffusion co-efficient of Cd(II) is of the order of 10(-11) m(2)/s. The maximum uptake was 36.23 mg/g. The adsorption data can be well described by Langmuir isotherm. The result of the equilibrium studies showed that the solution pH was the governing factor affecting the adsorption. Mass transfer analysis was also carried out for the adsorption process. The thermodynamic studies indicated that the adsorption was spontaneous and exothermic in nature. The sorption energy calculated from Dubinin-Radushkevich isotherm indicated that the adsorption process is chemical in nature. Desorption as well as the application studies were carried out considering the economic viewpoint of wastewater treatment plant operations.

Organochlorine pesticide residues in sediment cores of sunderban wetland, northeastern part of Bay of Bengal, India, and their ecotoxicological significance.

This paper presents the first comprehensive report of the organochlorine pesticide residues (OCs) such as hexachlorocyclohexane isomers (HCHs), dichlorodiphenyltrichloroethane and its six metabolites (DDTs), and hexachlorobenzene (HCB) in core sediments (<63-microm particle size) from the Indian Sunderban wetland. The pooled mean values of the mass fraction of SigmaHCHs, HCB, and SigmaDDTs in the sediments were 0.05-12, 0.05-1.4, and 0.05-11.5 ng g(-1) dry weight, respectively. The vertical distribution of pesticides reveals an erratic pattern. The concentration of four isomers of HCHs reveals a heterogenic distribution where gamma-HCH (lindane) and beta-HCH shared the dominant part. The mass fraction of HCB did not show any sharp spatial variation. The prevailing sequence of DDT metabolites indicates an active degradation of the parent compound in the sediments and/or inputs of already degraded pp'DDT to the region. Peak concentrations of HCH isomers and DDT metabolites have the potential to induce ecotoxicological impact as per the sediment quality guidelines.

Oxidants and ocular tumors.

Serum superoxide dismutase and catalase assays were performed using spectrophotometry in 60 adults and children with benign or malignant tumors and in controls. There was a statistically significant difference in the antioxidative status of children with intraocular tumors (primary retinoblastoma) compared with children without tumors. The difference was not significant in adults. These enzymes may be of value in the early diagnosis of malignant intraocular tumor, especially retinoblastoma.

Maximum entropy and the problem of moments: a stable algorithm.

We present a technique for entropy optimization to calculate a distribution from its moments. The technique is based upon maximizing a discretized form of the Shannon entropy functional by mapping the problem onto a dual space where an optimal solution can be constructed iteratively. We demonstrate the performance and stability of our algorithm with several tests on numerically difficult functions. We then consider an electronic structure application, the electronic density of states of amorphous silica, and study the convergence of the Fermi level with increasing number of moments.

Essential oil yield and quality of methyl eugenol rich Ocimum tenuiflorum L.f. (syn. O. sanctum L.) grown in south India as influenced by method of harvest.

A field experiment carried out during 2001--2002 under semi-arid conditions of Hyderabad, India investigated the effect of three different methods of harvesting at full bloom stage, on essential oil yield and quality of methyl eugenol rich sacred/holy basil (Ocimum tenuiflorum L.f.; Lamiaceae). The harvest methods were: harvesting of primary branches, secondary branches and shoot biomass cut at 30 cm above ground level. Four harvests at 102, 192, 287 and 360 days after transplanting of the crop were taken in 1 year in each method of harvest. Harvesting of secondary branches led to maximum plant height and number of secondary branches per plant compared to harvesting of primary branches or shoot biomass cut at 30 cm above ground during second, third and fourth harvests. On the contrary, secondary branch harvest gave least biomass yield in all the four harvests. But due to higher essential oil content, secondary branch harvest gave 25.2 and 15.4% higher total (sum total of all four harvests) essential oil yield (kg/ha per year) over primary branches and shoot biomass cut at 30 cm above ground methods of harvesting, respectively. A similar treatment difference was observed in respect of oil composition studied in the first harvest. Harvesting shoot biomass at 30 cm above ground produced oil containing highest amount of methyl eugenol. The content of methyl eugenol decreased in the order of shoot biomass cut at 30 cm above ground > primary branch > secondary branch treatments. A reverse trend was observed, however, in respect of (E)-cinnamyl acetate, eugenol and beta-elemene constituents of the oil. Little variability was, however, observed among the treatments in respect of 24 other constituents of the oils.

A simple microbiological assay for the stereospecific differentiation of alpha and beta isomers of arteether.

A new rapid bioassay has been developed which can precisely differentiate between stereospecific alpha and beta isomers of the antimalarial drug arteether. This method was developed through the disc diffusion bioactivity tests wherein semisynthetically produced alpha arteether was able to inhibit the growth of E. coli strains which are defective in DNA gyrase enzyme. The wild type E. coli with intact DNA gyrase did not show this sensitivity to alpha arteether. The beta isomer of arteether was, however, ineffective against both the mutant and wild type strains. Direct experimental proof of gyrase involvement was obtained through mobilization of gyr genes by transformation of E. coli gyr- mutant strains with wild type gyrA clone pMK90 (carried on the thermo-inducible lambda Col E1 vector). This resulted in alpha arteether resistant and nalidixic acid sensitive phenotype clearly demonstrating the use of gyrA mutant strains in differentiating alpha and beta isomers of arteether by this simple bioassay.

Modulation of alpha 5 beta 1 and alpha V beta 3 integrins on the cell surface during mitosis.

One of the hallmarks of cells undergoing mitotic division is their rounded morphology and reduced adhesion to the substratum. We have studied and compared the attachment of interphase and mitotic cells to substrata coated with fibronectin and vitronectin. We have found that adhesion of mitotic cells, as compared to interphase cells, is significantly reduced to fibronectin, but is higher to vitronectin. These results correlate well with the expression of alpha 5 beta 1 and alpha V beta 3 integrins, the respective receptors for fibronectin and vitronectin, on the cell surface. Mitotic cells show higher levels of alpha V beta 3 and very low levels of alpha 5 beta 1 proteins on the cell surface as compared to interphase cells. This difference in the levels of these integrins also reflects in the total amounts of fibronectin and vitronectin present on the cell surface of these cells. We have further shown, by flow cytometry, that binding of vitronectin, or the synthetic peptide -GRGDSP-, causes an increase in the intracellular levels of Ca2+ in mitotic cells, but no change is seen in the interphase cells. Binding of fibronectin to either of these cells fails to elicit any response. One interesting feature of our results is that the levels of total, i.e., cytoplasmic plus membrane bound, alpha 5 beta 1 and alpha V beta 3 integrins of mitotic and interphase cells remain the same, thus implying an alteration in the distribution of integrin chains between the plasma membrane and the cytoplasm during the conversion of interphase cells into the mitotic phase.

Sebaceous adenoma in the region of the medial canthus causing proptosis.

A case of sebaceous adenoma in the region of the medial canthus causing proptosis is presented along with a review of the medical literature. The clinicopathological aspects of the tumour are discussed. The mode of treatment was surgical excision. A six month follow-up showed a reduction in the proptosis with no recurrence.

Foot and mouth disease in gayals (Bos gaurus frontalis) in Calcutta Zoo.

A brief description is given of an outbreak of foot and mouth disease in gayals (Bos gaurus frontalis) which occurred in Calcutta Zoo in October 1990. Four of the five affected animals died within ten days of onset of the disease. The disease did not spread to other animals in the Zoo.

Percutaneous interstitial laser therapy of a patient with recurrent hepatoma in a transplanted liver.

We report in situ treatment, by focal hyperthermia, of a recurrent hepatoma in the transplanted liver of a 53-year-old man. Hyperthermia was generated by neodymium-yttrium-aluminum-garnet laser, which was delivered through a fiber placed inside a 19-gauge needle and inserted percutaneously into the liver under ultrasound guidance. The effect was monitored in real time by ultrasound and subsequently confirmed by computerized tomography and needle core biopsy. Objectively the tumor growth was halted for 3 months, indicating partial response to this minimally invasive treatment.

Effect of gamma-irradiation of Escherichia coli on cyclic AMP binding activity.

Cyclic AMP binding in the extract of E. coli was taken as a measure of cAMP receptor protein (CRP) present in the cells. The gamma-irradiation of cells caused a dose-dependent inhibition of cAMP binding activity indicating that CRP gene is affected by gamma-irradiation. The binding activity in cells irradiated with 240 Gy gamma-ray dose remained unaltered by post-irradiation incubation. This supports previous finding that the enhanced inhibition of the L-arabinose isomerase synthesizing capacity, following incubation of gamma-irradiated cells at higher doses, must be due to a different cause than the catabolite repression.