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Biomedical subjects

S Saha

Publications and source records attributed to S Saha.

At least 271 records · Page 15Linked to original sources
PubMed1977

Relations between tensile impact properties and microstructure of compact bone.

Standardized human and beef femoral compact bone specimens were tested in tensile impact and the dynamic mechanical properties were determined. The microstructure of 45 beef and 47 human bone specimens were examined histologically to determine if there is a structural basis to account for strength differences in the bone samples. Strong negative correlations were obtained between the maximum stress and the percentage area of secondary osteons in each specimen. For human bone samples, the energy absorption capacity and the modulus of elasticity were also found to have strong negative correlations with the percentage area of secondary osteons present in each specimen. Linear regression equations were obtained describing the impact strength properties in terms of the percentage areas of secondary osteons and cavities in the samples. Fracture surfaces of the tested bone specimens were examined in a scanning electron microscope. Most surfaces exhibited a fairly rough texture indicating a quasi-cleavage type of failure. Fractographic analysis of bone fracture surface was helpful in understanding the micromechanics of bone fracture.

Animals↗
PubMed1977

Tensile strength of wire-reinforced bone cement and twisted stainless-steel wire.

To assess the tensile strength of wire-reinforced bone cement as used for posterior spine fusion, standardized bone-cement specimens reinforced with stainless steel and Vitallium wires 0.5 and one millimeter in diameter were tested in tension. The results showed that tensile strength of bone cement was increased significantly by reinforcing it with metal wires, the increase in strength being proportional to the number of wires used. Even after failure of the cement, the reinforcing wires still carried an appreciable amount of load, thus avoiding the catastrophic failure of the cement alone. Specimens reinforced with Vitallium wires in general failed at higher loads than specimens reinforced with similar stainless-steel wires. Pull-out studies showed that a hook or a loop at the embedded end of straight wires significantly increased the load necessary to pull the wires out. The tensile strength of twisted stainless-steel wire composed of two 0.5-millimeter strands increased with the number of turns up to about eight turns per inch (2.54 centimeters) and then decreased.

Bone Cements↗
PubMed1976

A method for the estimation of free and esterified cholesterol involving thin-layer chromatography.

A method for the estimation of both free and bound cholesterol in serum and plasma involving thin-layer chromatography has been developed. The serum or plasma is applied as a band directly on the plate. Extraction of lipid material from this band and the chromatographic separation of the above components are carried out on the same plate. The components are extracted from the adsorbent directly with acetic acid and measured colorimetrically using iron(III) chloride-sulphuric acid reagent.

Acetates↗
PubMed1975

Triglyceride composition of Sapindus mukorossi seed oil.

The fatty acid composition of Sapindus mukorossi seed oil was determined by spectrophotometry, urea complexation, and gas liquid chromatography (GLC). The percentages of individual acids were found to be: palmitic, 4.0; stearic, 0.2; arachidic, 4.4; oleic 62.8; linoleic, 4.6; linolenic, 1.6; and eicosenoic, 22.4. Triglyceride composition was calculated from the fatty acid compositions of the native oil and of the monoglycerides produced from it by pancreatic lipase hydrolysis. The oil is composed of 0.1, 2.1, 22.0, and 75.8% trisaturated, monounsaturated disaturatd, diunsaturated monosaturated, and triunsaturated glycerides, respectively. The special characteristic of the Sapindus mukorossi seed oil is its content of 26.3 and 26.7% triolein and eicoseno-di-oleins, respectively.

Chromatography, Gas↗
PubMed1972

Portal hypertension in kala-azar.

The present study records haemodynamic studies in three patients with kala-azar, a parasitic disease. All the three patients had high intrasplenic pressure, mild to moderate elevation of wedged hepatic vein pressure, and increased or normal estimated hepatic blood flow. Liver histology showed marked proliferation and swelling of Kupffer cells in the sinusoids. One patient was studied serially for nine months following treatment which showed persistent elevation of intrasplenic pressure though wedge pressure and liver blood flow touched normal levels. Liver biopsy was essentially normal at this stage. These findings may have some relevance to the role of different parasitic infections in the pathogenesis of a heterogeneous group of non-cirrhotic portal fibroses.

Adult↗