61 research outputs found

    Synthesis of Multiwalled Carbon Nanotubes-Titania Nanomaterial for Desulfurization of Model Fuel

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    This work reported on the development of novel nanomaterials of multiwalled carbon nanotubes doped with titania (CNT/TiO2) for the adsorptive desulfurization of model fuel oils. Various analytical techniques such as field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR) were used for the characterization of the nanomaterials. The initial results indicated the effectiveness of the prepared CNT/TiO2 nanomaterials in removing sulfur compounds from model fuel oil. The adsorption of DBT, BT, and thiophene from model fuel onto the derived sorbents was performed using batch mode system. These CNT/TiO2 nanomaterials initially afforded approximately 45% removal of DBT, 55% BT, and more than 65% thiophene compounds from model fuels. The CNT/TiO2 nanomaterials provided an excellent activity towards interaction with organosulfur compounds. More experiments are underway to optimize the parameters for the adsorptive desulfurization processes. We believe that these nanomaterials as adsorbents will find useful applications in petroleum industry because of their operational simplicity, high efficiency, and high capacity

    Validation of a screening questionnaire for hip and knee osteoarthritis in old people

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    <p>Abstract</p> <p>Background</p> <p>To develop a sensitive and specific screening tool for knee and hip osteoarthritis in the general population of elderly people.</p> <p>Methods</p> <p>The Knee and Hip OsteoArthritis Screening Questionnaire (KHOA-SQ) was developed based on previous studies and observed data and sent to 11,002 people aged 60 to 90 years, stratified by age and gender, who were selected by random sampling. Algorithms of the KHOA-SQ were created. Respondents positive for knee or hip OA on the KHOA-SQ were invited to be evaluated by an orthopedic surgeon. A sample of 300 individuals negative for knee or hip OA on the KHOA-SQ were also invited for evaluation. Sensitivity and specificity were determined for the KHOA-SQ, as well as for KHOA-SQ questions. Classification and Regression Tree analysis was used to find alternative screening algorithms from the questionnaire.</p> <p>Results</p> <p>Of 11,002 individuals contacted, 7,577 completed the KHOA-SQ. Of 1,115 positive for knee OA, on the KHOA-SQ, 710 (63.6%) were diagnosed with it. For hip OA, 339 of the 772 who screened positive (43.9%) were diagnosed it. Sensitivity for the hip algorithm was 87.4% and specificity 59.8%; for the knee, sensitivity was 94.5% and specificity 43.8%. Two alternative algorithms provided lower specificity.</p> <p>Conclusion</p> <p>The KHOA-SQ offers high sensitivity and moderate specificity. Although this tool correctly identifies individuals with knee or hip OA, the high false positive rate could pose problems. Based on our questions, no better algorithm was found.</p

    Conjunctival nevi: clinical and histopathologic features in a Saudi population

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    Background and Objective : Conjunctival nevi are benign lesions with wide variation in clinical and histopathological features. The differentiation between benign nevi and other pigmented lesions is essential. The aim of our study was to identify the distribution of the histopathologic types of conjunctival nevi among the Saudi population and to provide the basic knowledge needed for proper clinical diagnosis. Patients and Methods : This retrospective study of surgically excised benign conjunctival nevi was conducted at a tertiary care eye hospital from 1995 to 2006. Clinical data was collected from medical records and the histopathologic features reviewed by a single pathologist. Results : A total 105 conjunctival nevi were included from 104 consecutive patients (mean age, 26 years, 54 males and 50 females). The anatomical location was the bulbar conjunctiva in 83&#x0025;, juxtalimbal in 12&#x0025;, caruncle in 4&#x0025; and palpebral in 1&#x0025;. The lesion was removed for cosmetic reasons in 38&#x0025; while 8&#x0025; of the lesions were removed to rule out malignancy. The compound nevus was the commonest (72&#x0025;) in all age groups, followed by subepithelial nevus (24&#x0025;) and finally junctional nevus (3&#x0025;). Conclusions : The distribution of the histopathologic types of this tumor in our population matches the pattern in other areas of the world with the compound nevus being the commonest lesion. However, fewer lesions among our patients are removed to rule out malignancy
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