Biomedical subjects

R Shariff

Publications and source records attributed to R Shariff.

4 recordsLinked to original sources

PubMed2002

Model-based advanced process control of coagulation.

The drinking water treatment industry has seen a recent increase in the use of artificial neural networks (ANNs) for process modelling and offline process control tools and applications. While conceptual frameworks for integrating the ANN technology into the real-time control of complex treatment processes have been proposed, actual working systems have yet to be developed. This paper presents development and application of an ANN model-based advanced process control system for the coagulation process at a pilot-scale water treatment facility in Edmonton, Alberta, Canada. The system was successfully used to maintain a user-defined set point for effluent quality, by automatically varying operating conditions in response to changes in influent water quality. This new technology has the potential to realize significant operational cost saving for utilities when applied in full-scale applications.

Alberta↗

PubMed1993

Epidemiology of salmonellosis and its sensitivity in Karachi.

Over the past five years 25,000 blood cultures were screened for septicaemia. Of these 6.7% were positive for salmonella species, the commonest being salmonella typhi accounting for 92% of total salmonella isolates. Over the years, S. typhi showed a gradual decline ranging from 96.7 to 87%. While salmonella paratyphi A has shown a gradual increase ranging from 2.5% to 11.4%. Salmonellosis peaked in the year 1990 suggesting an epidemic. The antibiotic sensitivity pattern showed a gradual increase in resistance over the years and even resistance to the new quinolones has emerged. Thus salmonellosis poses a major threat to the community and we must look into the alternative antibiotics to combat the threat.

Bacteremia↗

PubMed1988

Increased lipid peroxidation after lipid infusion as measured by breath pentane output.

We studied the effect of intravenous lipid infusion on lipid peroxidation as measured by breath pentane. Pentane, plasma alpha-tocopherol (alpha-tox) and plasma gamma-tocopherol (gamma-toc), selenium, and Se-dependent glutathione peroxidase (Se-GSHPx) were measured in 10 normal control subjects and in 10 home parenteral nutrition (HPN) patients before and after infusion of 100 mL Nutralipid 10% over 30 min. Before infusion, breath pentane was significantly higher and alpha-toc was significantly lower in the HPN group than in the control subjects. These two measurements were significantly negatively correlated (r = -0.54, p less than 0.05). Pentane, alpha-toc, and Se-GSHPx were significantly increased in both groups after lipid was infused but were still significantly higher in HPN patients than in control subjects. Thus, infusion of a small amount of lipid rich in linoleic acid induced a significant increase in breath pentane, reflective of increased lipid peroxidation.

Adult↗

PubMedDate not supplied

Vitamin E suppresses increased lipid peroxidation in cigarette smokers.

Cigarette smoke contains many xenobiotics, including oxidants and free radicals, which can increase lipid peroxidation. Recently, breath pentane output (BPO) has been recognized as a good indicator of lipid peroxidation. Vitamin E is known to be a potent free radical scavenger which can protect biological membranes against oxidative damage. We investigated the effect of vitamin E (dl-alpha-tocopherol) on lipid peroxidation in 13 healthy smokers. The results showed (1) smokers had increased BPO as compared with 19 healthy non-smokers (16.3 +/- 1.9 vs 5.8 +/- 0.5, pmol/kg body weight/min, p less than 0.001) although both groups had comparable plasma vitamin E and selenium concentrations, (2) supplementation with vitamin E (800 mg/day for 2 weeks) decreased BPO in smokers, and (3) the concentration of plasma selenium-dependent glutathione peroxidase was restored to normal in those smokers (five out of 13) in whom this was low initially. We conclude that a normal plasma concentration of vitamin E does not prevent this increase of lipid peroxidation in smokers but that substantial doses of vitamin E will significantly reduce this increased lipid peroxidation. If a major function of vitamin E is to protect lipids from peroxidation, then smokers have a conditioned insufficiency of vitamin E on a normal diet.

Adult↗