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Biomedical subjects

S R Ahmad

Publications and source records attributed to S R Ahmad.

12 recordsLinked to original sources
PubMed2006

Gamma-radiation induced changes in the physical and chemical properties of lignocellulose.

gamma-radiation induced effects on the physical and chemical properties of natural lignocellulose (jute) polymer were investigated. Samples were irradiated to required total doses at a particular dose rate. The changes in the parameters such as the tensile strength, elongation at break, and work done at rupture for the lignocellulose samples on irradiation with the gamma-rays from a cobalt-60 source were measured. The mechanical properties were found to have nonlinear relations with the radiation doses. The chemical stability of irradiated fibers was found to degrade progressively with the increase of radiation dose. Additionally, other chemical changes of the samples due to exposure to high-energy radiation were also investigated using fluorescence and infrared spectroscopic analysis. Differential scanning calorimetry and thermogravimetric studies showed a significant reduction in thermal stability. The wide-angle X-ray diffraction study showed that structural changes of cellulose appeared due to the radiation-induced chemical reaction of lignocellulose.

Cellulose↗
PubMed2005

An optical technique for in situ monitoring of trace metals in effluent.

An optical technique for real time elemental analysis in water environment is evaluated. This is based on laser-induced breakdown in water and the subsequent monitoring of atomic emission lines from the elemental species. Metals, such as copper, lead, iron, sodium etc, in water samples were detected and quantified from their relevant strong atomic emission lines. Experimental results show that metal concentrations in water at a level of a few mg l(-1) are detectable in a non-optimized but versatile experimental system. Elemental constituents in a sample of water effluent from a metal polishing factory for discharge in to streams was analysed and presented. A prototype of a portable system based on original equipment manufacturer's components has been constructed and its potential as a cost-effective effluent discharge monitor for selected elements is evaluated.

Environmental Monitoring↗
PubMed2004

A new technology for automatic identification and sorting of plastics for recycling.

A new technology for automatic sorting of plastics, based upon optical identification of fluorescence signatures of dyes, incorporated in such materials in trace concentrations prior to product manufacturing, is described. Three commercial tracers were selected primarily on the basis of their good absorbency in the 310-370 nm spectral band and their identifiable narrow-band fluorescence signatures in the visible band of the spectrum when present in binary combinations. This absorption band was selected because of the availability of strong emission lines in this band from a commercial Hg-arc lamp and high fluorescence quantum yields of the tracers at this excitation wavelength band. The plastics chosen for tracing and identification are HDPE, LDPE, PP, EVA, PVC and PET and the tracers were compatible and chemically non-reactive with the host matrices and did not affect the transparency of the plastics. The design of a monochromatic and collimated excitation source, the sensor system are described and their performances in identifying and sorting plastics doped with tracers at a few parts per million concentration levels are evaluated. In an industrial sorting system, the sensor was able to sort 300 mm long plastic bottles at a conveyor belt speed of 3.5 m.sec(-1) with a sorting purity of -95%. The limitation was imposed due to mechanical singulation irregularities at high speed and the limited processing speed of the computer used.

Automation↗
PubMed2001

Congestive heart failure associated with itraconazole.

Itraconazole is a synthetic antifungal agent approved in the USA for the treatment of onychomycosis and serious systemic fungal infections. Animal and clinical pharmacology studies suggest negative inotropic effects with itraconazole. Data from the US Food and Drug Administration's Adverse Event Reporting System suggest that use of itraconazole is associated with congestive heart failure. We summarise the details of 58 cases suggestive of congestive heart failure in association with the use of itraconazole. Labelling of itraconazole has been changed to alert physicians to this new finding.

Adolescent↗
PubMed1996

Quality of adverse drug experience reports submitted by pharmacists and physicians to the FDA.

The US Food and Drug Administration (FDA)'s Spontaneous Adverse Experience Reporting System is a computerized database with over one million adverse drug experience (ADE) reports. In 1992, the FDA received over 100,000 ADE reports and pharmacists were major contributors to these reports. In 1993, the FDA launched MEDWatch, a new initiative to enhance direct reporting of adverse events by health professionals. thus far, majority of reports to MEDWatch are from pharmacists. Drug regulatory agencies of some countries do not accept reports submitted by pharmacists. We performed a study to assess the quality of information in ADE reports submitted directly to the FDA by pharmacists and physicians and compared that with manufacturer-channelled 15-day reports. We evaluated 589 ADE reports with serious outcomes associated with nine new molecular entities. Data were analysed using Epi Info. Our results showed no substantial difference in a subjective assessment of the quality of information in the reports submitted by pharmacists or physicians, irrespective of whether these reports were submitted directly or via manufacturers. This study suggests that reports from hospital pharmacists are valuable and of comparable quality. We believe that all health professionals contribute to the success of FDA's MEDWatch programme and thereby play an important part in protecting public health by promptly reporting serious adverse events.

Journal Article↗
PubMed1992

Lomotil overdose.

Explore the source record for details and available documents.

Atropine↗
PubMed1990

A survey of paediatric prescribing and dispensing in Karachi.

In an effort to understand the paediatric prescribing practices of family physicians and dispensing of medicines from pharmacies, a survey was conducted in Karachi. Another objective was to understand the factors influencing such practices. Hundred family physicians and 55 pharmacists were surveyed. Four groups of drugs namely antidiarrhoeals, appetite stimulants, multivitamins and brain tonics were identified for assessment, these being drugs widely promoted by the pharmaceutical industry. Some of these drugs are known to have deleterious effects and therapeutic benefit of most of them is dubious. It was observed that roughly 55% of all drugs prescribed by the physicians fell into the aforementioned drug categories. These drugs also constituted nearly 60% of all sales of the pharmacies surveyed. The survey indicates that the antidiarrhoeal drugs Imodium (Ioperamide) and Lomotil (diphenoxylate) are being commonly prescribed though they have hazardous side effects and are unsuitable for use in children. Thirteen percent of physicians are still prescribing the anabolic steroid Durabolin (nandrolone phenylpropionate) as an appetite stimulant long after promotion for this purpose has been dropped. The survey indicates that 95% of the physicians relied upon industry promotional material as their main source of information about drugs. The survey highlights the need to introduce the concept of rational drug use in the undergraduate and postgraduate education.

Child↗