Leaching of copper converter slag withAspergillus niger culture filtrate

Leaching of copper converter slag of M/s Hindustan Copper Ltd, Ghatshila (Bihar, India) was carried out usingAspergillus niger culture filtrate. The effects of the duration of leaching, temperature, pulp density and the addition of hydrochloric acid were studied.A. niger culture filtrate solubilized metals from the converter slag at levels of 18.70% copper, 7.40% nickel and 4.00% cobalt. Addition of hydrochloric acid was found to improve copper, nickel and cobalt solubilization to 46.52, 27.90 and 37.96%, respectively. HPLC analysis of the fungal culture filtrate revealed the presence of succinic and citric acids. Therefore, leaching of the slag was also carried out with matching concentrations of these organic acids individually as well as with both mixed together. Results are discussed.     

Enzymatic responses of transplanted tumour cells towards estrogen, progesterone and testosterone.

The influence of estrogen, progesterone and testosterone on the activities of alkaline and acid phosphatases, adenosine triphosphatase and succinate dehydrogenase were determined by cytochemical methods in sarcoma 180 and Ehrlich's carcinoma cells transplanted in male and female Swiss mice. The results revealed differential effects of the sex hormones on different enzymes which seemed to depend on the type of tumour cell studied and the sex of the host mice.     

A comparative study of the gradual degradation of exines,resulting from the effects of temperature

The gradual degradation of three types of pollen exines from different plant groups (gymnosperms and angiosperms) with rising temperature has been observed and comparisons made. Pollen grains are heated to different temperatures (100°C–350°C) in a sealed copper tube, placed in a nichrome wire resistance furnace. In each case the pollen grains are heated for 100 hours.The colour change and the size reduction with rising temperature are common to all pollen types. The sexine or ornamented part of the pollen exine is affected first by rising temperature. In angiosperm pollen, the sexibe pattern is not recognisable at 300°C, but pine pollen retains its pattern up to 350°C. The nexine seems to be more stable at high temperatures than the sexinous elements and either remains unaltered with remnants of the sexinous pattern, or becomes altered and amorphous.The lamellar part of the nexine appears to be important and the evolutionary significance of the exine is discussed. The present work shows that the gymnosperm pollen has more stable exines, and may be better adapted for survival than angiosperm exines.