Patrick Das Gupta

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The demonstration of 5′-nucleotide phosphodiesterase at both the light and electron microscopic levels has been made possible with the use of a mixture of 5′-(5-iodo-3-indolyl)-5-fluorodeoxyuridine phosphodiester and 5′-(5-nitro-3-indolyl)-5-fluorodeoxyuridine phosphodiester as synthetic substrates. This mixture resulted in a stacking indigo dye with good(More)
The retinal structures of the compound eyes of insects are being investigated as par t of a comparative study of the s tructure and biochemistry of visual organs (1 5). T he compound eye of the insect is composed of numerous ommatidia , each of which consists of f rom four to eight re t inula cells. Each re t inula cell contains a differentiated structure,(More)
Protocols were developed for plant regeneration from callus induced in mature embryos of rice. Somaclonal variation was scored by genome mutation, chromosome mutation and plasmon mutation in R0, R1 and R2 plant progenies. The frequency of haploids and diploids appeared in the ratio of 20:33. Variation in the chromosome number in callus cells was found to be(More)
Three dimensional structure of developing ovarian follicles in the cat and the mouse were examined to clarify the cellular and the extra cellular components during follicular maturation by scanning electron microscopy. Epithelial cells of the membrana granulosa (MG) and the cumulus oophorus (CO) show variable morphology, which depends on the location of the(More)
Periodic acid methenamine silver staining has been used for proof of the existence of carbohydrates in both paraffin and resin embedded tissues. The staining was applied to delineate macrophages that have been well known as cells of mononuclear phagocyte system by stainable nature for lysosomes, and it is found to be useful method for detection of(More)
Terminally differentiated intermediate layers of vaginal epithelial cells from the late follicular phase of the pig show crystalline structures. Analysis of two dimensional images by transmission electron microscopy revealed that these structures are composed of rhomboid subunits. The longer side measures 26 nm whereas the smaller side measures 24 nm. The(More)
Incorporating a realistic model for accretion of ultra-relativistic particles by primordial blackholes (PBHs), we study the evolution of an Einstein-de Sitter universe consisting of PBHs embedded in a thermal bath from the epoch ∼ 10−33 sec to ∼ 5 × 10−9 sec. In this paper we use Barrow et al’s ansatz to model blackhole evaporation in which the modified(More)
In this paper, we study a sample of 65 short duration bursts contained in the 3B catalogue. We fit the time profiles of these GRBs with lognormal functions and study various temporal properties. In most of the multi-peaked bursts, our analysis leads to a statistical evidence for the evolution of temporal asymmetry in individual pulses i.e. subsequent pulses(More)
The binding of colloidal lanthanum to isolated biological membranes and lipid vesicles was studied by optical and X-ray spectroscopy, and by electron microscopy. Excellent correlation was observed using these techniques. The increase in turbidity and electron density appeared to be directly proportional to the extent of negative charge in the system. X-ray(More)
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