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Biomedical subjects

S Bhatia

Publications and source records attributed to S Bhatia.

At least 163 records · Page 9Linked to original sources

A survey of sterilization acceptors in a family planning program in rural Bangladesh.

The results of a survey of 275 Bangladeshi women who were sterilized at a rural family planning clinic are presented. The survey comprised two interviews of each woman: one conducted immediately prior to the sterilization procedure and the second conducted one month after each woman was sterilized. Sociodemographic data were gathered for the survey from the patients' clinic records. Reasons for the choice of sterilization and sociodemographic impact of the procedure are discussed, as are implications of the results on other rural family planning programs.

Adult↗

Design of peptides using alpha, beta-dehydro-residues: synthesis, crystal structure and molecular conformation of N-Boc-L-Val-delta Phe-delta Phe-L-Ala-OCH3.

To obtain general rules of peptide design using alpha, beta-dehydro-residues, a sequence with two consecutive delta Phe-residues, Boc-L-Val-delta Phe-delta Phe-L-Ala-OCH3, was synthesized by azlactone method in solution phase. The peptide was crystallized form its solution in an acetone/water mixture (70:30) in space group P6(1) with a = b = 14.912(3) A, c = 25.548(5) A, V = 4912.0(6) A3. The structure was determined by direct methods and refined by a full matrix least-squares procedure to an R value of 0.079 for 2891 observed [I > or = 3 delta (1)] reflections. The backbone torsion angles phi 1 = 54(1) degrees, psi 1 = 129(1) degrees, omega 1 = -177(1) degrees, phi 2 = 57(1) degrees, psi 2 = 15(1) degrees, omega 2 = -170(1) degrees, phi 3 = 80(1) degrees, psi 3 = 7(2) degrees, omega 3 = -177(1) degrees, phi 4 = -108(1) degrees and psi T4 = -34(1) degrees suggest that the peptide adopts a folded conformation with two overlapping beta-turns of types II and III'. These turns are stabilized by two intramolecular hydrogen bonds between the CO of the Boc group and the NH of delta Phe3 and the CO of Val1 and the NH of Ala4. The torsion angles of delta Phe2 and delta Phe3 side chains are similar and indicate that the two delta Phe residues are essentially planar. The folded molecules from head-to-tail intermolecular hydrogen bonds giving rise to continuous helical columns which run parallel to the c-axis. This structure established the formation of two beta-turns of types II and III' respectively for sequences containing two consecutive delta Phe residues at (i + 2) and (i + 3) positions with a branched beta-carbon residue at one end of the tetrapeptide.

Crystallization↗

Primary cerebral rhabdomyosarcoma.

Primary intracranial rhabdomyosarcomas are extremely rare tumors; those in the supratentorial location are commoner in adults. A 10 year old girl with primary cerebral rhabdomyosarcoma is presented.

Brain Neoplasms↗

Ruptured supratentorial dermoid cysts.

Two cases with ruptured supratentorial dermoid cysts are presented. Computerised tomography and magnetic resonance findings are illustrated. The pathology and differential diagnosis is discussed.

Adult↗

Correlations between esophageal diseases and manometric length: a study of 617 patients.

The purpose of this study was to measure the length of the esophagus and assess its relationship to sex, weight, age, height, and various esophageal disorders. A retrospective analysis was undertaken of 617 esophageal manometric studies, which included 51 normal control subjects (27 males and 24 females) and 566 patients (297 males and 269 females) with esophageal disorders (50 with achalasia, 6 with diffuse esophageal spasm, 64 with strictures, 38 with nutcracker esophagus, 398 with gastroesophageal reflux disease [GERD] with positive 24-hour pH monitoring, and 66 with possible GERD but negative 24-hour pH monitoring). Manometry was performed in all of them by the station pull-through technique. The length of the esophagus was defined as the distance between the proximal end of the upper esophageal sphincter and the distal end of the lower esophageal sphincter. In the control group the mean (+/- standard deviation) length of the esophagus was 28.3 +/- 2.41 cm. In patients with esophageal disorders the mean length of the esophagus was 28.0 +/- 2.87 cm. Length of the esophagus is related to height but not to weight, sex, age, diffuse esophageal spasm, or nutcracker esophagus. Achalasia is associated with a longer esophagus, and GERD is associated with a shorter esophagus. Stricture is associated with a shorter esophagus, but this is in part due to the association between stricture and GERD. Patients with possible GERD but negative 24-hour pH monitoring have an esophageal length similar to that of GERD patients with positive 24-hour pH monitoring. Patients with GERD and stricture formation showed esophageal shortening in shorter patients. Achalasia, GERD, and GERD with stricture formation influence esophageal length. GERD-related strictures shorten the esophagus more significantly in short patients.

Adult↗

Kinetics study of palm oil hydrolysis using immobilized lipase Candida rugosa in packed bed reactor.

Continuous hydrolysis of palm oil triglyceride in organic solvent using immobilized Candida rugosa on the Amberlite MB-1 as a source of immobilized lipase was studied in packed bed reactor. The enzymatic kinetics of hydrolysis reaction was studied by changing the substrate concentration, reaction temperature and residence time(tau) in the reactor. At 55 degrees C, the optimum water concentration was found to be 15 % weight per volume of solution (%w/v). The Michaelis-Menten kinetic model was used to obtain the reaction parameters, Km(app) and V max(app). The activation energies were found to be quite low indicating that the lipase-catalyzed process is controlled by diffusion of substrates. The Michaelis-Menten kinetic model was found to be suitable at low water concentration 10-15 %w/v of solution. At higher water concentration, substrate inhibition model was used for data analysis. Reactor operation was found to play an important role in the palm oil hydrolysis kinetic.

Bioreactors↗

Ability of Pycnoporus sanguineus to remove copper ions from aqueous solution.

The equilibrium sorption capacity of a macro-fungi, Pycnoporus sanguineus biomass was studied using a single-metal system comprising copper ions. The rate and extent for the removal of copper were subjected to environmental parameters such as pH, biomass loading, temperature, and contact time. Results showed that the uptake of copper increased as the pH increased. However, as the biomass loading increased, the amount of metal uptake decreased. Instead, temperature does not have a significant effect on the metal uptake, especially between 30 to 40 degrees C. A maximum adsorption of copper ions was also observed within 15 minutes of reaction time for the entire sample tested. Furthermore, pre-treatment with sodium bicarbonate and boiling water significantly improved the sorption capacity of copper by Pycnoporus sanguineus.

Biomass↗

Modeling and simulation of an enzymatic reactor for hydrolysis of palm oil.

Hydrolysis of palm oil has become an important process in Oleochemical industries. Therefore, an investigation was carried out for hydrolysis of palm oil to fatty acid and glycerol using immobilized lipase in packed bed reactor. The conversion vs. residence time data were used in Michaelis-Menten rate equation to evaluate the kinetic parameters. A mathematical model for the rate of palm oil hydrolysis was proposed incorporating role of external mass transfer and pore diffusion. The model was simulated for steady-state isothermal operation of immobilized lipase packed bed reactor. The experimental data were compared with the simulated results. External mass transfer was found to affect the rate of palm oil hydrolysis at higher residence time.

Biomass↗

Binding mechanism of heavy metals biosorption by Pycnoporus sanguineus.

Non-living biomass of Pycnoporus sanguineus has an ability to take up lead,copper and cadmium ions from an aqueous solution. The role played by various functional groups in the cell wall and the mechanism uptake of lead, copper and cadmium by Pycnoporus sanguineus were investigated. Modification of the functional groups such as lipids, carboxylic and amino was done through chemical pretreatment in order to study their role in biosorption of metal ions. Results showed that the chemical modification of these functional groups has modified the ability of biomass to remove lead, copper and cadmium ions from the solution. Scanning electron microscopy was also used to study the morphological structure of the biomass before and after adsorption. The electron micrograph indicated that the structure of biomass changed due to the adsorption of the metals onto the cell walls. Furthermore, the X-ray energy dispersion analysis (EDAX) showed that the calcium ion present in the cell wall of biomass was released and replaced by lead ions. This implied that an ion exchange is one of the principal mechanisms for metal biosorption.

Adsorption↗

Outbreak of kala-azar in Bombay.

A chance diagnosis of kala-azar in a patient referred from Acworth Leprosy Home in Bombay was followed up, resulting in an investigation of a total of 25 patients (inpatients and residents) for the presence of the disease. 30.3% of the patients investigated were found to be suffering from the disease. This confirms the earlier suspicion that Bombay and especially the Acworth Leprosy Home is an endemic area for kala-azar.

Adolescent↗