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Biomedical subjects

P K Sharma

Publications and source records attributed to P K Sharma.

At least 127 records · Page 7Linked to original sources
PubMed1982

Age-related changes in the total protein in the brain of Periplaneta americana (L.).

Quantitative changes in the total protein in the brain of aging male and female Periplaneta americana have been observed. A significant increase of total protein and neurosecretory cells in the brain up to 5 months, followed by a considerable decline in later age, points to a direct relationship between the neurosecretory cell number and reproductive phenomenon. Higher total protein concentration and cell number maintain reproduction up to 5 months while a decline after 6 months of adult life adversely affects reproduction. This suggests that neurosecretory cell number and protein concentration are related to reproduction and thereby aging.

Aging↗
PubMed1980

A versatile SAMI--a self contained digital heart beat counter.

The existing SAMI's (Socially acceptable monitoring instruments) as used for monitoring the variations in physiological parameters were considered to have certain drawbacks, such as trigger level adjustments and the need for frequent contact with the clinician/investigator. In the present system these drawbacks have been overcome by incorporating an automatic gain control into the circuitry and by using CMOS devices.

Computers↗
PubMed1980

Optimization of carrier frequency and duty cycle for pulse modulation of biological signals.

Digital modulation techniques are commonly used for the recording and transmission of biological signals. Hitherto, the choice of subcarrier frequency for recording or transmission of biological signals has been arbitary and this usually results in poor signal to noise ratio (SNR) due to the limited frequency characteristics of the system. In the present study the frequency characteristics of the system (first order approximation) has been taken to be that of a Butterworth filter. Computations based on this assumption show that for a given input signal there exists an optimum subcarrier frequency and a corresponding optimum duty cycle which would give maximum SNR of the system. For convenience, a nomogram has been prepared and it has been shown that for a given frequency response of the system, the nomogram could be used for selecting an optimum subcarrier frequency and a corresponding duty cycle. The theoretical formulations have been verified with experimental work.

Biomedical Engineering↗
PubMed1976

Biochemical and histochemical studies on non-specific phosphomonoesterases of swine kidney worm Stephanurus dentatus (Diesing, 1839).

Biochemical and histochemical studies have been made on non-specific acid and alkaline phosphomonoesterases of S. dentatus. The two forms of acid phosphomonoesterases have been found active at pH 4.0 and 6.0. The pH optima for the two forms of aklaline phosphomonoesterases lie at 8.0 and 10.0. Studies on the distribution of acid and alkaline phosphomonoesterases in various tissues have revealed an abundance of acid phosphomonoesterase in various parts of the alimentary canal and various organs of the reproductive system. The excretory ducts show alkaline phosphomonoesterase activity only.

Acid Phosphatase↗