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Showing papers by "University of Madras published in 2004"


Journal ArticleDOI
TL;DR: In this article, Petrographic, major, trace, and rare earth element compositions of sandstones from the upper Miocene Kudankulam Formation, Southern India, have been investigated to determine their provenance, tectonic setting, and weathering conditions.
Abstract: Petrographic, major, trace, and rare earth element compositions of sandstones from the upper Miocene Kudankulam Formation, Southern India, have been investigated to determine their provenance, tectonic setting, and weathering conditions. All sandstone samples are highly enriched in quartz (Q) but poor in feldspar (F) and lithic fragments (L). The major-element concentrations of these sandstones reveal the relative homogeneity of their source. Geochemically, the Kudankulam sandstones are classified as arkose, subarkose, litharenite, and sublitharenite. The CIA values (chemical index of alteration; mean value 44.5) for these sandstones and the A-CN-K diagram suggest their low-weathering nature. Similarly, their Fe2O3* + MgO (mean 2.7), Al2O3/SiO2 ( 0.09), K2O/Na2O ( 2.2) ratios and TiO2 contents ( 0.3) are consistent with a passive-margin setting. The Eu/Eu* ( 0.5), (La/Lu)cn ( 21), La/Sc ( 5.9), Th/Sc ( 1.9), La/Co ( 5.7), Th/Co ( 1.8), and Cr/Th ( 5.3) ratios support a felsic source for these sandstones. Chondrite-normalized REE patterns with LREE enrichment, flat HREE, and negative Eu anomaly also are attributed to felsic source-rock characteristics for Kudankulam sandstones. Total REE concentrations of these sandstones reflect the variations in their grain-size fractions. The source rocks are probably identified to be Proterozoic gneisses, charnockites, and granites of the Kerala Khondalite Belt, which must have been exposed at least since the late Miocene. Finally, the unusual Ni enrichment in the Kudankulam sandstones, unaccompanied by a similar enrichment in Cr, Co, and V, may be related to either the presence of pyrite in the sandstones or, more likely, the fractionation of garnet from the source rocks during transportation.

470 citations


Journal ArticleDOI
TL;DR: Both major elemental and trace metal concentrations indicated that the sediments represent weathered products of granite and charnockite, and shell fragments in the surface sediments are likely act as a carrier phase for nondetrital metals.

342 citations


Journal ArticleDOI
TL;DR: An increase in the level of lipid peroxides along with a concomitant decrease in the activities of superoxide dismutase, catalase, glutathione peroxidase and reduced glutathion content were observed in fluoride administered groups of rats, indicating altered antioxidant status may be attributed to the increased generation of free radicals.

207 citations


Journal ArticleDOI
TL;DR: The efficacy of Eugenia jambolana seed kernel in the amelioration of diabetes is revealed, which may be attributed to its hypoglycemic property along with its antioxidant potential.
Abstract: Oxidative stress plays an important role in chronic complications of diabetes. In the present study the antioxidant effect of oral administration of ethanolic extract of Eugenia jambolana seed kernel on tissue antioxidant enzymes and lipid peroxidation in liver and kidney of streptozotocin-induced diabetic rats was evaluated. Administration of seed kernel to diabetic rats significantly decreased the levels of blood glucose, glycosylated hemoglobin and increased body weight gain, plasma insulin and hemoglobin. The diabetic rats showed the low activities of superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione content in liver and kidney, which were restored to near normal levels by treatment with the seed kernel extract. The increased levels of lipid peroxidation and hydroperoxides in diabetic rats were reverted back to near normal levels after the treatment with seed kernel extract. Diabetic rats treated with seed kernel extract restored almost normal architecture of liver and kidney and were confirmed by histopathological examination. The present study reveals the efficacy of Eugenia jambolana seed kernel in the amelioration of diabetes, which may be attributed to its hypoglycemic property along with its antioxidant potential. The antioxidant effect of Eugenia jambolana seed kernel was also compared with glibenclamide, a standard hypoglycemic drug.

205 citations


Journal ArticleDOI
TL;DR: An attempt has been made to evaluate the presence of hypoglycemic activity in the alcoholic extract of Aloe vera gel, which is believed to maintain the glucose homeostasis by controlling the carbohydrate metabolizing enzymes.
Abstract: In the present study an attempt has been made to evaluate the presence of hypoglycemic activity in the alcoholic extract of Aloe vera gel. Effects of oral administration of A. vera extract at a concentration of 200 and 300 mg/kg of body weight on (a) normal fasted rats, (b) oral glucose-loaded rats, and (c) streptozotocin-induced diabetic rats have been studied. A. vera extract maintain the glucose homeostasis by controlling the carbohydrate metabolizing enzymes.

198 citations


Journal ArticleDOI
TL;DR: The effect of 1H-pyrazole carboxylates on the mycelial growth of plant pathogenic fungi is revealed and the first X-ray structure in the family of microbicidal 1 H- pyrazole-4-carboxylate is presented.

172 citations


Journal Article
TL;DR: Protective action of Solanum trilobatum extract was evaluated in an animal model of hepatotoxicity induced by carbon tetrachloride to suggest the recovery from CCl4 induced hepatic damage due to its antioxidant and hepatoprotective property.
Abstract: Results: Levels of marker enzymes such as alanine transminase (ALT), aspartate transa- minase (AST), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) were increased significantly in CCl 4 treated rats (group II). STE brought about a significant decrease in the activities of all these enzymes. Lipid peroxidation (LP) was increased significant in liver tissue in the CCl 4 treated rats (group II) while the activities of glutathione peroxidase (GP x ), catalase (CAT) and superoxide dismutase (SOD) were decreased. STE treatment led to the recovery of these levels to near normal. Interpretation & conclusion: The present observations suggested that the treatment with S. trilobatum extract enhance the recovery from CCl 4 induced hepatic damage due to its antioxidant and hepatoprotective property.

169 citations


Journal ArticleDOI
TL;DR: The present study shows that Eugenia jambolana seed kernel decreased oxidative stress in diabetic rats, which inturn may be due to its hypoglycemic property.

166 citations


Journal ArticleDOI
TL;DR: In this article, selected triazole derivatives have been synthesised and evaluated as corrosion inhibitors for mild steel in natural aqueous environment by weight loss, potentiodynamic polarisation and ac impedance methods.

162 citations


Journal ArticleDOI
TL;DR: It is concluded that apigenin prevents LPO and protects antioxidant system in DEN induced and phenobarbital promoted hepatocellular carcinogenesis and protects oxidative stress caused by the carcinogen.

154 citations


Journal ArticleDOI
TL;DR: In this paper, seven new copper(II) complexes of 2-hydroxyacetophenone N(4)-substituted thiosemicarbazones (H2L) and bidentate polypyridyl compounds 2,2′-bipyridine and 1,10-phenanthroline (B) were prepared and characterized.

Journal ArticleDOI
TL;DR: In this paper, the authors analyzed surface sediment samples from two seasons to obtain a preliminary view of its environmental conditions, geochemical distribution of major elements (Si, Al, Fe, Ca, Mg, Na, K, P), trace elements (Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd) and acid leachable elements (Fe, Mn, Cr., Cd, Cu and Zn) in the Gulf of Mannar.
Abstract: The Gulf of Mannar along the Tuticorin coast is a coral base of the southeast coast of India. To obtain a preliminary view of its environmental conditions, geochemical distribution of major elements (Si, Al, Fe, Ca, Mg, Na, K, P), trace elements (Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd) and acid leachable elements (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd) were analyzed in surface sediment samples from two seasons. Geochemical fractionation confirmed the lithogenic origin of metals, which were mainly associated with the detrital phase. The sediments in the gulf are sandy with abundant calcareous debris, which controls the distribution of total and acid leachable elements. Enrichment factors relative to crust vary by a magnitude of two to three and the presence of trace metals indicates the input of Cr, Pb, Cd, Cu and Zn in both forms through industrial activities. Factor analysis supports the above observation with higher loadings on acid leachable elements and its association with CaCO3. The increase in concentration of trace metals (Cr, Pb, Cd, Cu, Co, Ni, Zn) along the Gulf of Mannar indicates that the area has been contaminated by the input from riverine sources and the industries nearby. The present study indicates that other sources should be evaluated in the long-term monitoring program.

Book ChapterDOI
TL;DR: Adhesion of Chlorella vulgaris, Nitzschia amphibia and Chroococcus minutus to hydrophobic, glass and toxic substrata and the number of attached cells was found to be directly proportional to the culture density.
Abstract: Adhesion of Chlorella vulgaris (chlorophyceae), Nitzschia amphibia (bacillariophceae) and Chroococcus minutus (cyanobacteria) to hydrophobic (perspex, titanium and stainless steel 316-L), hydrophilic (glass) and toxic (copper, aluminium brass and admiralty brass) substrata were studied in the laboratory. The influence of surface wettability, surface roughness, pH of the medium, culture age, culture density, cell viability and presence of organic and bacterial films on the adhesion of Nitzschia amphibia was also studied using titanium, stainless steel and glass surfaces. All three organisms attached more on titanium and stainless steel and less on copper and its alloys. The attachment varied significantly with respect to exposure time and different materials. The attachment was higher on rough surfaces when compared to smooth surfaces. Attachment was higher on pH 7 and above. The presence of organic film increased the attachment significantly when compared to control. The number of attached cells was found to be directly proportional to the culture density. Attachment by log phase cells was significantly higher when compared to stationary phase cells. Live cells attached more when compared to heat killed and formalin killed cells. Bacterial films of Pseudomonas putida increased the algal attachment significantly.

Proceedings ArticleDOI
05 Apr 2004
TL;DR: In this article, the significance of the steganographic techniques that are employed in information processing algorithms for data security is brought out, focusing mainly on images, and tries to state the various properties and characteristics that the Steganographic algorithms should possess.
Abstract: With the ever increasing amount and variety of data to be stored and transmitted in various mediums, the specification of security which has to be established at various levels of medium access and the accompanying issues of authentication and authorization has become a critical factor. Various steganographic, watermarking and data-embedding algorithms have usually manipulated the actual data in order to either hide any coveted information or to provide some level of access control over the medium. The mediums are usually images, video, audio etc., wherein specific portions or the overall space is usually 'corrupted' with 'significant' data. We attempt to bring out the significance of the steganographic techniques that are employed in information processing algorithms for data security. It deals with the problem of data security, focusing mainly on images, and tries to state the various properties and characteristics that the steganographic algorithms should possess. We also highlight the technique of masking used in the conventional steganographic LSB algorithms and in its variants.

Journal ArticleDOI
TL;DR: MSM in Chennai slums are at high risk for HIV, and prevention strategies aimed at changing unsafe drug and sexual practices should target the general population of men, with specific attention to areas with high rates of MSM.
Abstract: Objective: To estimate HIV and sexually transmitted disease (STD) prevalence and behavioral risk characteristics of men who have sex with men (MSM) in Chennai, India. Methods: A cross-sectional population-based random sample survey was conducted in 2001. Randomly selected residents of 30 slums in Chennai were interviewed for behavioral risk factors through face-to-face interviews. Sera and urine were examined for syphilis, HIV-1, gonorrhea, and chlamydia. Logistic regression analyses were used to assess associations between MSM status and HIV infection and to identify risk characteristics of MSM. Results: Of 774 men, 46 reported (5.9%) sex with other men. MSM were more likely to be seropositive for HIV (odds ratio [OR] = 8.57; 95% confidence interval [Cl]: 1.83, 40.23) and were more likely to have a history of STD (OR = 2.66; 95% CI: 1.18, 6.02) than non-MSM. Men who used illicit drugs in past 3 months (adjusted odds ratio [AOR] = 4.01; 95% CI: 1.92, 8.41), ever exchanged money for sex (AOR = 3.93; 95% CI: 1.97, 7.84), or were ever tested for HIV (AOR = 3.72; 95% Cl: 1.34, 10.34) were significantly more likely to report sex with men. Conclusions: MSM in Chennai slums are at high risk for HIV. HIV prevention strategies aimed at changing unsafe drug and sexual practices should target the general population of men, with specific attention to areas with high rates of MSM.

Journal ArticleDOI
TL;DR: In this paper, the authors fitted the Orange II exptl. points in the presence of the Co2+/oxone reagent and followed the trend known for reactions presenting a chain radical branched mechanism.
Abstract: Accelerated bleaching, photobleaching and mineralization of the non-biodegradable azo-dye, Orange II, was obsd. with oxone in solns. with Co2+-ions. The bleaching rate of Orange II in the dark was found to follow a first-order kinetics with respect to [Co2+] with a rate const. of 20 M-1 s-1. Fitting of the Orange II photobleaching exptl. points in the presence of the Co2+/oxone reagent was carried out and followed the trend known for reactions presenting a chain radical branched mechanism. The photobleaching trace could be fitted by a single math. expression with an error <5% with respect to the exptl. data. The bleaching trace obsd. for the Orange II soln. in the dark followed zero-order decay kinetics. In a typical run, Orange II (0.20 mM or TOC 30 mg C/L) in the presence of oxone and Co2+ was bleached under visible light within .apprx.15 s. The Co2+-ion concns. necessary to catalyze the Orange II mineralization by oxone was obsd. to be .apprx.100 times lower than the oxone concn. A 100% TOC decrease, under visible light irradn., was attained for an Orange II (0.2 mM) soln. in the presence of Co2+-ions (0.06 mM) and oxone (20 mM) within times .apprx.70 min for solns. purged with oxygen. Under visible light irradn., Orange II mineralization in the presence of O2 involves the photo-dissocn. of reaction intermediates leading to org. peroxides in the second step of the mineralization process. [on SciFinder (R)]

Journal ArticleDOI
TL;DR: In combination LA and DMSA completely ameliorated the lead induced oxidative damage and either compound alone was however only partially protective against lead damage.
Abstract: Oxidative stress with subsequent lipid peroxidation has been postulated as one mechanism for lead toxicity. Hence in assessing the protective effects of lipoic acid (LA) and meso 2,3-dimercaptosuccinic acid (DMSA) on lead toxicity, they were tested either separately or in combination for their effects on selected indices of hepatic oxidative stress. Elevated levels of lipid peroxides were accompanied by altered antioxidant defense systems. Lead acetate (Pb - 0.2%) was administered in drinking water for five weeks to induce toxicity. LA (25 mg kg−1 body wt. day−1 i.p) and DMSA (20 mg kg−1 body wt. day−1 i.p) were administered individually and also in combination during the sixth week. Lead damage to the liver was evident in the decreases in hepatic enzymes alanine transaminase (−38%), aspartate transaminase (−42%) and alkaline phosphatase (−43%); increases in lipid peroxidation (+38%); decreases in the antioxidant enzymes catalase (−45%), superoxide dismutase (−40%), glutathione peroxidase (−46%) and decreases in glutathione (−43%) and decreases in glutathione metabolizing enzymes, glutathione reductase (−59%), glucose-6-phosphate dehydrogenase (−27%) and glutathione-S-transferase (−42%). In combination LA and DMSA completely ameliorated the lead induced oxidative damage. Either compound alone was however only partially protective against lead damage.

Journal Article
TL;DR: T. chebula extract pretreatment was found to ameliorate the effect of isoproterenol on lipid peroxide formation and retained the activities of the diagnostic marker enzymes.
Abstract: Cardioprotective effect of ethanolic extract of Terminalia chebula fruits (500 mg/kg body wt) was examined in isoproterenol (200 mg/kg body wt) induced myocardial damage in rats. In isoproterenol administered rats, the level of lipid peroxides increased significantly in the serum and heart. A significant decrease was observed in the activity of the myocardial marker enzymes with a concomitant increase in their activity in serum. Histopathological examination was carried out to confirm the myocardial necrosis. T. chebula extract pretreatment was found to ameliorate the effect of isoproterenol on lipid peroxide formation and retained the activities of the diagnostic marker enzymes.

Journal ArticleDOI
TL;DR: It could be concluded that Cassia fistula bark extracts (CFA & CFM) possess significant anti-inflammatory and anti oxidant properties.
Abstract: Anti-inflammatory and Antioxidant activities of the aqueous (CFA) and methanolic extracts (CFM) of the Cassia fistula Linn. bark were assayed in wistar albino rats. The extracts were found to posses significant anti-inflammatory effect in both acute and chronic models. Cassia fistula bark extracts showed significant radical scavenging by inhibiting lipid peroxidation initiated by CCl4 and FeSO4 in rat liver and kidney homogenates. Both extracts exhibited significant antioxidant activity in DPPH, Nitric oxide and Hydroxyl radical induced invitro assay methods. Both extracts showed Dose-dependent protective effect against lipid peroxidation and free radical generation in liver and kidney homogenates. Further, the acute toxicity study with the extracts showed no sign of toxicity up to a dose level of 2000 mg/ po. Thus it could be concluded that Cassia fistula bark extracts (CFA & CFM) possess significant anti-inflammatory and anti oxidant properties.

Journal ArticleDOI
TL;DR: In this paper, aqueous extract of aerial parts (HAA) and root (HAR) were screened for its anti-nociceptive property using both chemical and thermal methods of nociception in mice.
Abstract: Hygrophila auriculata (Schum) Heine (syn) Asteracantha longifolia Nees, Acanthaceae was described in ayurvedic literature as Ikshura, Ikshugandha, and Kokilasha. The plant was extensively used in traditional system of medicine for various ailments like rheumatism, inflammation, jaundice, hepatic obstruction, pain, etc. The aqueous extract of aerial parts (HAA) and root(HAR) were screened for its anti-nociceptive property using both chemical and thermal methods of nociception in mice. In chemical method acetic acid writhing test and in thermal methods hot plate and tail flick tests were performed. Both the extracts at doses 100 and 200 mg/kg/p.o inhibited the abdominal constrictions induced by acetic acid and also increased the pain threshold of mice towards the thermal source in a dose dependent manner. The activity exhibited by the extracts was comparable to that of the standard drug aspirin (100 mg/kg/p.o). From the results it was concluded that both extracts exhibited anti-nociceptive activity by central and peripheral mechanism(s).

Journal ArticleDOI
TL;DR: The effect of naphthalene on lipid peroxidation and antioxidants status was studied in hepatopancreas, haemolymph and ovary of the Scylla serrata with reference to the active vitellogenic stage.

Journal ArticleDOI
TL;DR: Pre-co-treatment with Centella asiatica (200 mg/kg of body wt/oral) extract significantly prevented these alterations and restored the enzyme activities to near normal levels during adriamycin induced cardiac damage in rats.

Journal ArticleDOI
TL;DR: The phenotype of LCA in patients with AIPL1 mutations is relatively severe, with a maculopathy in most patients and keratoconus and cataract in a large subset, and the ERG of a parent heterozygote carrier revealed significantly reduced rod function.
Abstract: Objectives: To describe the phenotype of Leber congenital amaurosis (LCA) in 26 probands with mutations in aryl hydrocarbon receptor interacting protein-like 1 protein (AIPL1) and compare it with phenotypes of other LCA-related genes. To describe the electroretinogram (ERG) in heterozygote carriers. Methods: Patients with AIPL1-related LCA were identified in a cohort of 303 patients with LCA by polymerase chain reaction single-strand confirmational polymorphism mutation screening and/or direct sequencing. Phenotypic characterization included clinical and ERG evaluation. Seven heterozygous carrier parents also underwent ERG testing. Results: Seventeen homozygotes and 9 compound heterozygotes were identified. The W278X mutation was most frequent (48% of alleles). Visual acuities ranged from light perception to 20/400. Variable retinal appearances, ranging from near normal to varying degrees of chorioretinal atrophy and intraretinal pigment migration, were noted. Atrophic and/or pigmentary macular changes were present in 16 (80%) of 20 probands. Keratoconus and cataracts were identified in 5 (26%) of 19 patients, all of whom were homozygotes. The ERG of a parent heterozygote carrier revealed significantly reduced rod function, while ERGs for 6 other carrier parents were normal. Conclusions: The phenotype of LCA in patients with AIPL1 mutations is relatively severe, with a maculopathy in most patients and keratoconus and cataract in a large subset. Rod ERG abnormalities may be present in heterozygous carriers of AIPL1 mutations. Clinical Relevance: Understanding and recognizing the phenotype of LCA may help in defining the course and severity of the disease. Identifying the gene defect is the first step in preparation for therapy since molecular diagnosis in LCA will mandate the choice of treatment.

Journal ArticleDOI
TL;DR: The present study suggests that Aroclor 1254 exposure induces oxidative stress in rat Sertoli cells and furthermore that simultaneous administration of Vitamin C or E ameliorated these effects.

Journal ArticleDOI
TL;DR: Cardiotoxicity, evident from increased activities of serum creatine phosphokinase, lactate dehydrogenase, aspartatetransaminase and alanine transaminase in CP administered rats, was reversed by LA treatment, highlighting the efficacy of LA as a cytoprotectant in CP induced cardiotoxicity.

Journal ArticleDOI
TL;DR: Piperine could effectively inhibit B(a)P-induced lung carcinogenesis in albino mice by offering protection from protein damage and also by suppressing cell proliferation.

Journal ArticleDOI
TL;DR: In this paper, single crystals of cadmium thiourea acetate (CTA) have been grown from a low-temperature solution method by a slow evaporation method at ambient temperature.

Journal ArticleDOI
TL;DR: Administration of the ethanolic extract of kernel at a concentration of 100 mg/kg of body weight significantly decreased the levels of blood glucose, blood urea, and cholesterol, increased glucose tolerance and levels of total proteins and liver glycogen, and decreased the activities of glutamate oxaloacetatetransaminase and glutamate pyruvate transaminase in experimental diabetic rats.
Abstract: The present study evaluated the hypoglycemic activity of different parts of Eugenia jambolana seeds such as whole seed, kernel, and seed coat on streptozotocin-induced diabetic rats. Administration of the ethanolic extract of kernel at a concentration of 100 mg/kg of body weight significantly decreased the levels of blood glucose, blood urea, and cholesterol, increased glucose tolerance and levels of total proteins and liver glycogen, and decreased the activities of glutamate oxaloacetate transaminase and glutamate pyruvate transaminase in experimental diabetic rats. Whole seed showed a moderate hypoglycemic effect, and seed coat did not show any hypoglycemic effect. The hypoglycemic efficacy was compared with that of glibenclamide, a standard hypoglycemic drug.

Journal ArticleDOI
TL;DR: Findings indicate a cytoprotective role of lipoic acid in this experimental model of testicular toxicity, and show normal lipid peroxidation and antioxidant defenses during cyclophosphamide-induced injury.

Journal ArticleDOI
TL;DR: In D-galactosamine/lipopolysaccharide (D-GalN/LPS)-induced hepatitis rats, a significant increase of lipid peroxidation and decreased liver antioxidant enzyme levels are observed and Pretreatment with allicin prevented these alterations.