Development of polyvinyl chloride biofilms for succession of selected marine bacterial populations.

Present investigation was made to bring out the pattern of biofilm formation by heterotrophic bacteria on nontoxic material, polyvinyl chloride (PVC) sheet fitted wooden rack that was immersed in seawater and the study was conducted in Tuticorin coast. Samplings were made over a period of 7 days with the following time period intervals: 30 min, 1, 2, 4, 24, 48, 72, 96, 120 and 144 hr. Bacterial enumeration was made by spread plate method on nutrient agar medium and characterization of bacterial isolates up to generic level was done. Gram-negative bacteria like Pseudomonas sp., Enterobacter sp., Aeromonas sp., Cytophaga sp. and Flavobacterium sp. were found to be the pioneer in colonizing the surface within 30 min and seven genera were represented in the biofilm. Among them two genera were found belonging to Gram-positive groups which included Micrococcus and Bacillus sp. The early stage biofilm i.e. up to 24th hr was wholly constituted by Gram-negative groups. However, the population density of Pseudomonas sp. was found to be higher (315 CFU) when compared to other Gram-negative forms. Occurrence of Gram-positive group was noted only at 48th hr old biofilm (28 to 150 CFU). The period between 48 and 96th hr was the transition where both the Gram-negative and Gram-positive groups co- existed. After 96th hr, the biofilm was found constituted only by Gram-positive groups. The isolates of early stage biofilm were found to produce allelopathic substance like bacteriocin.

Corrosion behaviour and biofouling characteristics of structural steel in the coastal waters of the Gulf of Mannar (Bay of Bengal), India.

The corrosion behaviour and biofouling characteristics of structural steel coupons at three different locations in the Gulf of Mannar were studied over a period of 2 years. Oyster fouling was predominant at Tuticorin open sea, while barnacle fouling was more pronounced at Mandapam and Tuticorin harbour. Among the three locations, Tuticorin open sea showed a markedly higher biomass, particularly after 12 and 18 months. The extent of crevice corrosion caused by hard foulers was more pronounced at Tuticorin harbour when compared to that at the other two locations. The corrosion rate of the structural steel coupons for 24 months was in the order, Mandapam > Tuticorin harbor > Tuticorin open sea. The loss in tensile strength at 12 and 24 months was in the order, Tuticorin open sea > Tuticorin harbor > Mandapam. The corrosion behaviour of the structural steel coupons was strongly influenced by the variations in the biofouling assemblage at the three different coastal locations.

The influence of sunlight on the localized corrosion of UNS S31600 in natural seawater.

Tests were conducted on the performance of UNS S31600 stainless steel (SS) in a natural day/night cycle vs full darkness under conditions of natural marine biofilm accumulation. In quiescent flowing seawater tests in the laboratory as well as under natural immersion in the sea, diffuse sunlight (∼10% of natural) counteracted the influence of marine biofilms and produced substantial inhibition of the corrosion of SS. Thus, the probabilities (percentage attack) and propagation rates (depths of attack) in multiple crevice tests were substantially lower in the day/night cycle than in the dark. A benefit was also observed for welded SS in terms of the time to corrosion initiation and the mass loss. SS in the passive state showed broader passive regions, well-defined breakdown potentials and markedly smaller anodic and cathodic current densities under the diurnal cycle. The overall reduction in corrosion is attributed to a combination of electrochemical photoinhibition and simultaneous photoinactivation of microbially mediated metal redox reactions linked to cathodic kinetics. These data offer fresh insights into the behaviour of SS under practical seawater situations and the proposed potential use of illumination in the mitigation of biologically influenced consequences.

Elecrokinetic separation of sulphate and lead from sludge of spent lead acid battery.

A novel electrokinetic (EK) technique is applied to separate lead and sulphate from the sludge of used/spent lead acid battery. XRD reveals that the sludge is a mixture of (PbO)(4) [Pb(SO(4))], Pb(2)O(3), PbSO(4), Pb(S(2)O(3)) and Pb(2)(SO(4)) which upon DC voltage application in a EK cell employing either titanium electrodes or titanium substrate insoluble anode as electrodes caused migration of sulphates and lead ions respectively into anode and cathode compartments, and accumulation of insoluble lead oxides at the central compartment. The insoluble lead oxides accumulated at the central compartment in the ratio 1:3, respectively for the high oxygen over-voltage Ti-anode (Ti-EK cell) and low oxygen over-voltage TSIA-anode (TSIA-EK cell) shows the superiority of Ti anode over TSIA anode. Also thermal investigation reveals Pb deposited at Ti-cathode is superior to that from TSIA cathode. This process does not release air/soil pollutants which are usually associated with high temperature pyrotechnic process.

Formulation and Evaluation of Hydroxypropyl Methylcellulose-based Controlled Release Matrix Tablets for Theophylline.

The objectives of the study were to formulate hydroxypropyl methyl cellulose-based controlled release matrix tablets for theophylline with varying drug:polymer ratios (1:1 and 1:2) and differing tablet hardness (5, 6 and 7 kg/cm(2)), and to evaluate the tablet's physico-chemical properties such as hardness, uniformity of weight, friability, drug content and in vitro drug release. Initially, granules were made by wet granulation technique and evaluated for angle of repose, bulk density, tapped density, bulkiness, compressibility index and hausner ratio. The results indicate good flow property of the granules and thus, the evaluated tablet physical properties were within the acceptable limits. The FT-IR study for the F-6 formulation showed that there was no interaction between the drug and the polymer. In vitro release studies were performed using Disso-2000 (paddle method) in 900 ml of pH 7.4 at 50 rpm. The result indicated that at high drug:polymer ratio (1:2) and hardness value 7 kg/cm(2), prolonged drug release was observed than the low drug: polymer ratio (1:1) and hardness values (5 and 6 kg/cm(2)). The release kinetics was found to follow korsmeyers-peppas model and the mechanism of drug release was by non-fickian or anomalous diffusion. The F-6 formulation was chosen for stability studies. F-6 formulation was stable when it was kept at different temperatures for a period of 6 months.

Formulation and Evaluation of Theophylline Controlled Release Matrix Tablets using Guar gum

Theophylline controlled release matrix tablets were prepared with guar gum in two ratios and with three different hardness of 5, 6 and 7kg/cm2. Theophylline controlled release granules were prepared and evaluated for the angle of repose, bulk density, tapped density, compressibility index and hausners ratio. All the formulation showed good flow properties. The compressed tablets were evaluated for the hardness, uniformity of weight, friability, drug content and invitro dissolution studies. All the formulations showed compliance with pharmacopial standards. There was no interaction between drug, polymer and other excipients. It was confirmed by FTIR studies. Among all the formulations F6 (i.e. polymer ratio1:2 and hardness 7kg/cm2) showed prolong release when compare to other formulations. The drug release kinetics showed zero order. The optimum formulation (F6) was stable when it was stored at 40 + 20 C, 280 + 20 C and at 450 + 20 C for 6 months(AU)

Evaluation of electrochemical oxidation techniques for degradation of dye effluents--a comparative approach.

The high energy cost of an electrochemical method is the fatal drawback that hinders its large scale application in wastewater treatment. The traditional single-chamber electrochemical method used in the waste water treatment mainly focused on anodic oxidation, but hydrogen produced on the cathode and indirect electrochemical treatment involves application of an electrical current to the wastewater containing chloride to convert into chlorine/hypochlorite. The two-compartment electrolytic cell, separated by an anion exchange membrane, has been developed in this work. In the new reactor, indirect oxidation at anode, indirect oxidation by hydrogen peroxide and ultraviolet/hydrogen peroxide (UV/H(2)O(2)) at cathode can occur simultaneously. The electrochemically produced hydrogen peroxide at the cathode by reduction of oxygen is affected by passing atmospheric air. Therefore "dual electrochemical oxidation" in one electrochemical reactor was achieved successfully. Compared to a traditional one-cell reactor, this reactor reduces the energy cost approximately by 25-40%, and thus the present work becomes significant in wastewater treatment. Experiments were carried out at different current densities using Ti/RuO(2)/IrO(2) as anode and carbon felt gas diffusion electrode used as a cathode fed with oxygen containing gases to produce hydrogen peroxide. During the various stages of electrolysis, the parameters such as, effect of pH, chemical oxygen demand (COD), colour, energy consumption were monitored. UV-vis spectrometry, Fourier transform infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC) studies were carried out to assess efficiencies of dye degradation.

Cathodic behaviour of stainless steel in coastal Indian seawater: calcareous deposits overwhelm biofilms.

Type-316 stainless steel (SS) was investigated as the cathode in galvanic couples in full-strength seawater from the Gulf of Mannar on the southeast coast of India. Tests were devised to examine the impact of SS cathodes on anode materials with or without the accrual of marine biofilms. Biofilmed SS cathodes significantly enhanced the rate of corrosion of nickel, causing noble shifts in the couple potentials. With mild steel and zinc as the anodes, calcareous deposits developed quite rapidly on the SS cathodes and led to a significant reduction of bacterial numbers. The calcareous deposits also caused substantial reduction of galvanic corrosion rates for mild steel, whereas there was no difference for zinc. The deposits were identified by XRD as essentially carbonates, oxides and hydroxides of calcium and magnesium. Potentiodynamic polarization performed on the actual couples after disconnection and equilibration provided reasonable interpretations of the galvanic corrosion trends. Data from this work suggest that a potential of about -0.70 V vs. saturated calomel electrode (SCE) should provide optimum protection of SS in warmer, full-strength seawater that supports the precipitation of calcareous deposits. The criterion commonly recommended for temperate conditions of lower water temperature and estuarine waters of lower alkalinity is -1.0 V (SCE).

Formulación y evaluación de comprimidos matriciales de clorhidrato de ambroxol, usando un polímero natural hidrofílico / Formulation and Evaluation of Matrix tablets of Ambroxol hydrochloride using Natural hydrophilic polymer

Se prepararon comprimidos matriciales de liberación prolongada de clorhidrato de ambroxol con diversas proporciones de fármaco: polímero tales como F-1(1:1), F-2(1:1,5) y F-3 (1:2). Se utilizó goma xántica para la formación de la matriz y celulosa microcristalina como diluyente. Se prepararon y evaluaron gránulos para determinar la densidad aparente sin compactar, la densidad compactada, el índice de compresibilidad, el índice de Hausner y el ángulo de reposo. Todos los gránulos se lubricaron y comprimieron con punzones planos de 9 mm. Los comprimidos se evaluaron para determinar la uniformidad de peso, el contenido de principios activos, la friabilidad, la dureza y la disolución in vitro. Todas las formulaciones se ajustaron a los estándares farmacopeicos. F-3 mostró una liberación prolongada de fármaco durante 12 horas con una liberación del 97,3% y el perfi l de liberación fue similar al de la muestra de clorhidrato de ambroxol comercial (A-MS). Además, se realizaron estudios de estabilidad según la guía ICH. La liberación de fármaco sigue cinéticas de orden cero (0,9661) y se determinó que el mecanismo era difusión combinada con erosión (AU)

Sustained release matrix tablets of ambroxol hydrochloride of different drug: polymer ratios, such as F-1(1:1), F- 2(1:1.5) and F-3 (1:2). Xanthan gum was used as matrix former and microcrystalline cellulose was used as diluent. Granules were prepared and evaluated for loose bulk density, tapped density, compressibility index, hausners ratio and angle of repose. All the granules were lubricated and compressed using 9mm fl at-faced punches. Compressed tablets were evaluated for uniformity of weight, content of active ingredient, friability, hardness and In-vitro dissolution. All the formulations showed compliance with Pharmacopoeial standards. F-3 showed the sustained release of drug for 12 hours with 97.3% release and the release profi le was close to the marketed sample of ambroxol hydrochloride (A-MS) and Stability studies were performed as per ICH guide. The drug release follows zero order kinetics (0.9661) and the mechanism was found to be diffusion coupled with erosion (AU)

Plasma CRP level predicts left ventricular function and exercise capacity in patients with acute myocardial infarction.

BACKGROUND: C-reactive protein estimation can help in predicting short- and long-term prognosis after acute myocardial infarction. High plasma C-reactive protein level in the acute phase strongly indicates a poor clinical outcome of the patients with myocardial infarction. METHODS AND RESULTS: One hundred consecutive patients admitted with ST elevation myocardial infarction in the intensive coronary care unit in our hospital who were able to do symptom-limited treadmill test during early recovery phase were studied. Plasma C-reactive protein was measured at the time of admission by immunoturbidity method. The normal value of the C-reactive protein was taken as 0.8 mg/dl. Echocardiographic study was done on day three of admission and ejection fraction was estimated by modified Simpson's method. Symptom-limited treadmill exercise test was done in all the patients. Patients were classified into two groups based on level of C-reactive protein: those with low C-reactive protein level (1.26 +/- 0.91 mg/dl, n=40) and those with high C-reactive protein level (6.52 +/- 3.97 mg/dl, n=60). Ejection fraction was lower in high C-reactive protein group (46.7 +/- 11.9%) compared to low C-reactive protein group (56.9 +/- 7.7%) (p = 0.011). Exercise capacity was lower in high C-reactive protein group (2.8 +/- 1.4 METs) compared to low C-reactive protein group (5.5 +/- 2.5 METs) p = 0.027). CONCLUSIONS: C-reactive protein levels are an index of the severity of myocardial necrosis which translate to worse left ventricular function. Higher the C-reactive protein level, lower the ejection fraction and worse may be the prognosis.

Analgesic activity of Cassia alata leaf extract and kaempferol 3-o-sophoroside.

The analgesic activity of an extract of the leaves of Cassia alata and kaempferol 3-O-sophoroside were studied after intraperitoneal injection in mice and rats using the tail clip, tail flick, tail immersion and acetic acid-induced writhing methods and the results compared with morphine. Maximum analgesic activity of the extract was apparent 120 min after injection. Fifty milligrams of kaempferol 3-O-sophoroside appeared equivalent to 100 mg of the extract.

Seasonal variations of organochlorine insecticide residues in air from Porto Novo, South India.

Air samples collected from Porto Novo (11 degrees 29' N, 79 degrees 46' E), Tamil Nadu State, South India from December, 1987 to January, 1989 were analysed to determine the seasonal variations of the levels of organochlorine insecticides such as HCH (BHC) and DDT. Both these insecticides showed higher levels from August to January, although this trend was more marked in HCH than DDT, reflecting the application of HCH largely, and probably small quantities of DDT during the flowering season of rice. The alpha-HCH was detected as a dominant isomer for all seasons monitored followed by gamma-HCH. Among DDT compounds, p,p'-DDT was the highest except in dry season (January to April) when p,p-DDE showed higher percentage. The levels and percentage composition of these insecticides recorded in the present study may aid in interpreting the role of a 'point source' area since India is one of the countries still using the persistent organochlorine pesticides in large quantities.

Effect of Cassia alata leaf extract on hyperglycemic rats.

The oral effectiveness of Cassia alata leaf extract on streptozotocin-induced hyperglycemia in rats has been studied and the results compared with glybenclamide. While the extract has no effect on glucose levels in normoglycemic animals, it reduced the blood sugar value in streptozotocin-induced hyperglycemic animals.

Sublethal effects of carbaryl on surfacing behaviour and food utilization in the air-breathing fish, Macropodus cupanus.

Sublethal effects of carbaryl on surfacing behaviour and food utilization in the obligatory air-breathing fish Macropodus cupanus were studied by rearing the fish individually in freshwater (pesticide-free) and four different sublethal concentrations of carbaryl (1 to 2.5 ppm). M. cupanus exhibited increased surfacing with the increased concentration of carbaryl. Enhanced rate of surfacing may be the result of stress exerted by the toxicant. Food intake of M. cupanus reared in different concentrations of carbaryl did not vary significantly. Growth decreased with increased concentrations of carbaryl, possibly due to excessive expenditure of energy on metabolism that otherwise could have been channelled into fish growth. Frequent surfacing may also account for the expenditure on metabolism. Hence, the conversion efficiency of M. cupanus reared at higher concentrations of carbaryl was poor and was inversely related with higher concentrations of carbaryl.