Effect of the extract of Thespesia populnea leaves on mice testis

Male swiss mice were administered with the leaf extract of Thespesia populnea at a daily dose of 400 mg/kg body weight for 15 days and the testis were subjected to structural analysis. The structure of the seminiferous tubule in the testis of treated animal was elongated. Sertoli cells were enlarged in its structure and spermatids became round and disintegrated. It is suggested that the extract of T. populnea treatment leads to pathological changes in the seminiferous tubules, Sertoli cells and spermatids of the testis.     

Changes in the excretory patterns of the fresh-water field crab Paratelphusa hydrodromous upon adaptation to higher salinities

Changes in the exeretory patterns of the fresh-water field crab Paratelphusa hydrodromous were studied in relation to salinity adaptation. Fifty percent sea-water medium was found to be the threshold of a change from ammonotelism to ureotelism in the crabs. Adaptation for 11 days in the 100% (=34 S) sea water brought about this change. Sea-water-adapted crabs excreted more urea, uric acid, and trimethylamine than controls, irrespective of starvation. Starvation reduced the quantitative excretion. Blood aspartic and glutamic acid levels increased on adaptation to sea water, in contrast to the levels of asparagine and glutamine. The activities of asparaginase and glutaminase in the tissues decreased on salinity adaptation. The reduction in amidase activity in 100% sea-water-adapted crabs is discussed with reference to acid-base homeostasis in the crabs.Dedicated to the memory of the late Professor K. Pampapathi Rao, who died on 23 June, 1973.     

Heavy metals in two fish species (Carangoidel malabaricus and Belone stronglurus) from Pulicat Lake, North of Chennai, Southeast Coast of India

We present the results from a detailed study based on five metals (Cr, Cd, Zn, Pb and Fe) measured in four organs (gills, liver, intestine and muscle) of two fish species (Carangoidel malabaricus and Belone stronglurus) from Pulicat Lake in southeast coast of India. The results show marked differences between the two species and organs as well as significant variations within the five analyzed metals. Although the metal concentrations measured in fish muscle are low, high levels of Pb and Fe were observed in the liver and gills of the two fish species. The concentrations of heavy metals in edible parts (muscle) of fish were within the permissible levels and are safe for the human consumption.     

Click chemistry approach to conventional vegetable tanning process: accelerated method with improved organoleptic properties

Click chemistry approaches are tailored to generate molecular building blocks quickly and reliably by joining small units together selectively and covalently, stably and irreversibly. The vegetable tannins such as hydrolyzable and condensed tannins are capable to produce rather stable radicals or inhibit the progress of radicals and are prone to oxidations such as photo and auto-oxidation, and their anti-oxidant nature is well known. A lot remains to be done to understand the extent of the variation of leather stability, color variation (lightening and darkening reaction of leather), and poor resistance to water uptake for prolonged periods. In the present study, we have reported click chemistry approaches to accelerated vegetable tanning processes based on periodates catalyzed formation of oxidized hydrolysable and condensed tannins for high exhaustion with improved properties. The distribution of oxidized vegetable tannin, the thermal stability such as shrinkage temperature (T _s) and denaturation temperature (T _d), resistance to collagenolytic activities, and organoleptic properties of tanned leather as well as the evaluations of eco-friendly characteristics were investigated. Scanning electron microscopic analysis indicates the cross section of tightness of the leather. Differential scanning calorimetric analysis shows that the T _d of leather is more than that of vegetable tanned or equal to aldehyde tanned one. The leathers exhibited fullness, softness, good color, and general appearance when compared to non-oxidized vegetable tannin. The developed process benefits from significant reduction in total solids and better biodegradability in the effluent, compared to non-oxidized vegetable tannins.     

Carbohydrate metabolism in the leg muscles of the fresh-water field crab Paratelphusa hydrodromous adapted to high salinities

Utilization of marine plants and their constituents by bacteria isolated from the guts of echinoids was investigated to determine the potential role bacteria may have in carbohydrate digestion in echinoids. Bacteria from the guts of the regular echinoids Lytechinus variegatus (Lamarck) and Arbacia punctulata (Lamarck) could physically degrade the marine plants Ulva lactuca and Eucheuma nudum, but not Caulerpa prolifera. Diplanthera wrightii and Thalassia testudinum were only slightly degraded by the gut bacteria. Bacteria from the guts of the irregular echinoids Mellita quinquiesperforata (Leske) and Encope aberrans (Martens) could not physically degrade any of these marine plants. Mixed and some isolated bacteria from the gut of L. variegatus could utilize xylose, rhamnose, glucose, galactose, laminarin, carageenan, starch and agar, but not cellulose or chitin. The results with isolates suggest that the bacteria of the echinoid gut are fairly non-selective. The bacteria of the guts of the two regular echinoids could utilize certain marine plants that the echinoids eat and certain of the plant constituents. The bacteria could not utilize plant fibers.     

Estimation of 210Po and 210Pb and its dose to human beings due to consumption of marine species of Ennore Creek, South India

A systemic study on the natural radionuclides such as (210)Po and (210)Pb in the environmental matrices and biota of Ennore Creek has been undertaken to establish a baseline data on the radiation profile of Ennore Creek environment. The environmental samples such as water, sediment, and biota (seaweeds, molluscs, crustaceans, and fishes) have been subjected to analyses. It has been observed that the concentration of (210)Po and (210)Pb in the water samples of Ennore Creek as 2.7 and 1.63 m Bq L(-1), respectively. The activity concentration of (210)Po and (210)Pb in the sediment sample was 17.9 and 28.9 Bq kg(-1), respectively. The bivalve mollusk Perna viridis have been identified to accumulate higher concentrations of (210)Po and (210)Pb suggesting that they could serve as bioindicator of radionuclides in the Ennore Creek environment. The committed effective dose for human beings was found at 81.13-216.8 and 2.1-297.2 μSv year(-1) for (210)Po and (210)Pb, respectively.     

Diesel reformulation using bio-derived propanol to control toxic emissions from a light-duty agricultural diesel engine

In the Indian agricultural sector, millions of diesel-driven pump-sets were used for irrigation purposes. These engines produce carcinogenic diesel particulates, toxic nitrogen oxides (NOx), and carbon monoxide (CO) emissions which threaten the livelihood of large population of farmers in India. The present study investigates the use of n-propanol, a less-explored high carbon bio-alcohol that can be produced by sustainable pathways from industrial and crop wastes that has an attractive opportunity for powering stationary diesel engines meant for irrigation and rural electrification. This study evaluates the use of n-propanol addition in fossil diesel by up to 30% by vol. and concurrently reports the effects of exhaust gas recirculation (EGR) on emissions of an agricultural DI diesel engine. Three blends PR10, PR20, and PR30 were prepared by mixing 10, 20, and 30% by vol. of n-propanol with fossil diesel. Results when compared to baseline diesel case indicated that smoke density reduced with increasing n-propanol fraction in the blends. PR10, PR20, and PR30 reduced smoke density by 13.33, 33.33, and 60%, respectively. NOx emissions increased with increasing n-propanol fraction in the blends. Later, three EGR rates (10, 20, and 30%) were employed. At any particular EGR rate, smoke density remained lower with increasing n-propanol content in the blends under increasing EGR rates. NOx reduced gradually with EGR. At 30% EGR, the blends PR10, PR20, and PR30 reduced NOx emissions by 43.04, 37.98, and 34.86%, respectively when compared to baseline diesel. CO emissions remained low but hydrocarbon (HC) emissions were high for n-propanol/diesel blends under EGR. Study confirmed that n-propanol could be used by up to 30% by vol. with diesel and the blends delivered lower soot density, NOx, and CO emissions under EGR.     

Assessment of heavy metals (Cd, Cr and Pb) in water, sediment and seaweed (Ulva lactuca) in the Pulicat Lake, South East India

The concentrations of three heavy metals chromium (Cr), cadmium (Cd) and lead (Pb) were examined in water, sediment and green algae (Ulva lactuca); collected from six different stations at Pulicat Lake, which receives effluents from industries located in North Chennai Coastal region. Concentrations of Cd (64.21 microg g(-1)) and Cr (28.51 microg g(-1)) were found to be high in sediment, whereas in green algae concentration of Pb (8.32 microg g(-1)) was higher than water and sediment samples. The relative abundance of these heavy metals in U. lactuca and sediment were found to be in the order Cd>Cr>Pb, whereas in water the ratio was found to be Cr>Pb>Cd. The seasonal variations in Cd and Pb followed a similar pattern in both seaweeds and sediments, but not in water samples. Spearman correlation coefficient study showed no significant correlation in the concentration of metals in U. lactuca, water and sediment samples.     

Metal ion-induced enhanced oxidation of organic contaminants by ferrate: a review

Environmental Chemistry Letters - The global contamination of water resources by organic contaminants such as pharmaceuticals and pesticides is calling for advanced remediation techniques, yet...     

Intake of Chromium by the Adult Population of Mumbai City

Electro Thermal Atomic Absorption Spectrophotometry (ET-AAS), is used for the determination of chromium (Cr) in a variety of environmental matrices. The detection limit for the estimation of Cr is 2 pg absolute for a volume injection of 20 l. The precision of the method is established by analysing Cr from a synthetic mixture containing various elements in different qualities (0.5–10 ppm) and is found to be within ± 8%. The reliability of estimation is further assessed through the analysis of Standard Reference Materials (SRMs) of soil, hay, milk powder and lake sediment obtained from IAEA.The total intake of Cr through air, water and food works out to be 54 g/day for the adult population of Mumbai city. The dietary intake through food is the major contributor to the total intake of Cr. The concentration of Cr in atmospheric air and drinking water collected from different suburbs showed geometric mean concentrations of 0.09 g/m³ and 0.3 g/l, respectively. The daily intake of Cr, though lower, is closer to the lower bound of the recommended value of 50–200 g/day.