Objectives We aimed to evaluate the personal, professional, and psychological impact of the COVID... more Objectives We aimed to evaluate the personal, professional, and psychological impact of the COVID-19 pandemic on hospital workers and their perceptions about mitigating strategies. Design Cross-sectional web-based survey consisting of (1) a survey of the personal and professional impact of the COVID-19 pandemic and potential mitigation strategies, and (2) two validated psychological instruments (Kessler Psychological Distress Scale [K10] and Impact of Events Scale Revised [IES-R]). Regression analyses were conducted to identify the predictors of workplace stress, psychological distress, and post-traumatic stress. Setting and participants Hospital workers employed at 4 teaching and 8 non-teaching hospitals in Ontario, Canada during the COVID-19 pandemic. Results Among 1875 respondents (84% female, 49% frontline workers), 72% feared falling ill, 64% felt their job placed them at great risk of COVID-19 exposure, and 48% felt little control over the risk of infection. Respondents percei...
Obesity is associated with increased oesophageal acid exposure time (AET) in patients with gastro... more Obesity is associated with increased oesophageal acid exposure time (AET) in patients with gastro-oesophageal reflux (GER), and may decrease the effects of proton pump inhibitors (PPIs). To evaluate the effects of increased body mass on the ability of PPI therapy to decrease AET in patients with reflux symptoms. Acid exposure time profiles collected from adult patients using wireless pH-metry while on or off PPI therapy was retrospectively reviewed. Patients were separated into five body mass index (BMI) categories as defined by the World Health Organization. A multivariable logistic regression evaluated the association between abnormal AET and BMI groups while controlling for age, gender and pH capsule placement methods. The study group comprised 968 patients with 336 (34.7%) studied on a PPI and 632 (65.3%) studied off PPI therapy. AET (total greater than 5.3%) was found more frequently in the overweight (67%) and obese classes (74-80%) compared to those who were normal weight (40...
Although there are no clinical decision rules for radiograph use among persons with shoulder pain... more Although there are no clinical decision rules for radiograph use among persons with shoulder pain, they are ordered for most patients. Previously published reviews have demonstrated that radiography is overutilized in evaluating emergency department (ED) patients with shoulder pain, and clinical factors might define patients in whom plain film radiography need not be performed. The objectives of this study were to identify predictors of clinically significant shoulder pain and develop a clinical decision radiograph-ordering rule for adult ED patients with shoulder pain. Records from adult ED visits resulting in shoulder radiographs were reviewed. Potential predictors of clinically significant shoulder pain were then identified. Univariate screening was performed to find variables associated with injury and were subsequently included in a multivariable prediction model. Five of the predetermined factors were found to be associated with the likelihood of injury: history of trauma, ran...
The standard technique for electron therapy has several inherent problems. First, the cutouts in ... more The standard technique for electron therapy has several inherent problems. First, the cutouts in electron cones for field shaping are labour intensive to produce, cumbersome to use and reduce the clearance between the treatment machine and the patient. Secondly, it is difficult to modulate treatment depth and match multiple fields with electron beams due to electron multiple scattering. We propose the use of photonMLC for electron field shaping to improve treatment efficiency and convenience. Unfortunately, using the photonMLC to shape an electron beam significantly increases the penumbra of the treatment field, which can be reduced using a subsequent photonIMRT boost field. Electron beams shaped with a Varian Millennium MLC were recently commissioned in Pinnacle V7.6 (Philips). Using forward or inverse intensity‐modulated radiotherapy(IMRT) planning techniques, MLC segments for a step‐and‐shoot IMRT field were determined for improving electron beam penumbra, depth modulation and electron‐photon field. The technique has been applied to a few clinical cases, such as whole CNS irradiation and cancer of parotid. Inverse planned IMRT will be used to optimize photon‐electron‐combined irradiation for cancer of the parotid. Generated plans are verified using film and ion chamber measurements. Using boost IMRT fields, we showed a similar 50%–95% penumbra for the MLC shaped electron field compared to the penumbra with an electron applicator (100cm SSD). In conclusion, combined photonIMRT and electron beam improves dose uniformity, beam junction, and depth modulation.
A case of cervical thorotrast granuloma and its surgical complications is presented. The properti... more A case of cervical thorotrast granuloma and its surgical complications is presented. The properties and usage of thorotrast and its later complications are described, and the management of the complications is discussed. It is emphasized that there is usually a long latent period between thorotrast exposure and the advent of complications and perhaps more cases of similar difficulty may be anticipated in the future.
... CRACKS AKHTAR S. KHAN, XINWH WANG and SYED SARWAR SHAH School of Aerospace and Mechanical Eng... more ... CRACKS AKHTAR S. KHAN, XINWH WANG and SYED SARWAR SHAH School of Aerospace and Mechanical Engineering University of Oklahoma, Norman, OK 73019, USA Abstract Numerical failure analyses are presented for jet engine starter's breech pressure chambers. ...
The redox behaviour of a potential anticancer organic compound, 5,8-dihydroxynaphthalene-1,4-dion... more The redox behaviour of a potential anticancer organic compound, 5,8-dihydroxynaphthalene-1,4-dione (DND), was investigated in 1 : 1 buffered aqueous ethanol using cyclic, differential pulse, and square wave voltammetry. The redox processes were found to occur in a pH-dependent diffusion-controlled manner. Presence of an α-hydroxyl group stabilised semiquinone radical of DND, formed by the gain of 1 e– and 1 H+, prevented the second step reduction, which is in contrast to the general mechanism previously reported for quinines in protic and aprotic media. In addition, our results supported an independent oxidation and reduction process. Square wave voltammetry provided evidence about the reversible and quasi-reversible nature of oxidation and reduction peaks. Based on the voltammetric results, the electrode reaction mechanism of DND was proposed. Parameters including pKa, transfer coefficient, diffusion coefficient, and electron transfer rate constant were evaluated. The values of pKa...
Objectives We aimed to evaluate the personal, professional, and psychological impact of the COVID... more Objectives We aimed to evaluate the personal, professional, and psychological impact of the COVID-19 pandemic on hospital workers and their perceptions about mitigating strategies. Design Cross-sectional web-based survey consisting of (1) a survey of the personal and professional impact of the COVID-19 pandemic and potential mitigation strategies, and (2) two validated psychological instruments (Kessler Psychological Distress Scale [K10] and Impact of Events Scale Revised [IES-R]). Regression analyses were conducted to identify the predictors of workplace stress, psychological distress, and post-traumatic stress. Setting and participants Hospital workers employed at 4 teaching and 8 non-teaching hospitals in Ontario, Canada during the COVID-19 pandemic. Results Among 1875 respondents (84% female, 49% frontline workers), 72% feared falling ill, 64% felt their job placed them at great risk of COVID-19 exposure, and 48% felt little control over the risk of infection. Respondents percei...
Obesity is associated with increased oesophageal acid exposure time (AET) in patients with gastro... more Obesity is associated with increased oesophageal acid exposure time (AET) in patients with gastro-oesophageal reflux (GER), and may decrease the effects of proton pump inhibitors (PPIs). To evaluate the effects of increased body mass on the ability of PPI therapy to decrease AET in patients with reflux symptoms. Acid exposure time profiles collected from adult patients using wireless pH-metry while on or off PPI therapy was retrospectively reviewed. Patients were separated into five body mass index (BMI) categories as defined by the World Health Organization. A multivariable logistic regression evaluated the association between abnormal AET and BMI groups while controlling for age, gender and pH capsule placement methods. The study group comprised 968 patients with 336 (34.7%) studied on a PPI and 632 (65.3%) studied off PPI therapy. AET (total greater than 5.3%) was found more frequently in the overweight (67%) and obese classes (74-80%) compared to those who were normal weight (40...
Although there are no clinical decision rules for radiograph use among persons with shoulder pain... more Although there are no clinical decision rules for radiograph use among persons with shoulder pain, they are ordered for most patients. Previously published reviews have demonstrated that radiography is overutilized in evaluating emergency department (ED) patients with shoulder pain, and clinical factors might define patients in whom plain film radiography need not be performed. The objectives of this study were to identify predictors of clinically significant shoulder pain and develop a clinical decision radiograph-ordering rule for adult ED patients with shoulder pain. Records from adult ED visits resulting in shoulder radiographs were reviewed. Potential predictors of clinically significant shoulder pain were then identified. Univariate screening was performed to find variables associated with injury and were subsequently included in a multivariable prediction model. Five of the predetermined factors were found to be associated with the likelihood of injury: history of trauma, ran...
The standard technique for electron therapy has several inherent problems. First, the cutouts in ... more The standard technique for electron therapy has several inherent problems. First, the cutouts in electron cones for field shaping are labour intensive to produce, cumbersome to use and reduce the clearance between the treatment machine and the patient. Secondly, it is difficult to modulate treatment depth and match multiple fields with electron beams due to electron multiple scattering. We propose the use of photonMLC for electron field shaping to improve treatment efficiency and convenience. Unfortunately, using the photonMLC to shape an electron beam significantly increases the penumbra of the treatment field, which can be reduced using a subsequent photonIMRT boost field. Electron beams shaped with a Varian Millennium MLC were recently commissioned in Pinnacle V7.6 (Philips). Using forward or inverse intensity‐modulated radiotherapy(IMRT) planning techniques, MLC segments for a step‐and‐shoot IMRT field were determined for improving electron beam penumbra, depth modulation and electron‐photon field. The technique has been applied to a few clinical cases, such as whole CNS irradiation and cancer of parotid. Inverse planned IMRT will be used to optimize photon‐electron‐combined irradiation for cancer of the parotid. Generated plans are verified using film and ion chamber measurements. Using boost IMRT fields, we showed a similar 50%–95% penumbra for the MLC shaped electron field compared to the penumbra with an electron applicator (100cm SSD). In conclusion, combined photonIMRT and electron beam improves dose uniformity, beam junction, and depth modulation.
A case of cervical thorotrast granuloma and its surgical complications is presented. The properti... more A case of cervical thorotrast granuloma and its surgical complications is presented. The properties and usage of thorotrast and its later complications are described, and the management of the complications is discussed. It is emphasized that there is usually a long latent period between thorotrast exposure and the advent of complications and perhaps more cases of similar difficulty may be anticipated in the future.
... CRACKS AKHTAR S. KHAN, XINWH WANG and SYED SARWAR SHAH School of Aerospace and Mechanical Eng... more ... CRACKS AKHTAR S. KHAN, XINWH WANG and SYED SARWAR SHAH School of Aerospace and Mechanical Engineering University of Oklahoma, Norman, OK 73019, USA Abstract Numerical failure analyses are presented for jet engine starter's breech pressure chambers. ...
The redox behaviour of a potential anticancer organic compound, 5,8-dihydroxynaphthalene-1,4-dion... more The redox behaviour of a potential anticancer organic compound, 5,8-dihydroxynaphthalene-1,4-dione (DND), was investigated in 1 : 1 buffered aqueous ethanol using cyclic, differential pulse, and square wave voltammetry. The redox processes were found to occur in a pH-dependent diffusion-controlled manner. Presence of an α-hydroxyl group stabilised semiquinone radical of DND, formed by the gain of 1 e– and 1 H+, prevented the second step reduction, which is in contrast to the general mechanism previously reported for quinines in protic and aprotic media. In addition, our results supported an independent oxidation and reduction process. Square wave voltammetry provided evidence about the reversible and quasi-reversible nature of oxidation and reduction peaks. Based on the voltammetric results, the electrode reaction mechanism of DND was proposed. Parameters including pKa, transfer coefficient, diffusion coefficient, and electron transfer rate constant were evaluated. The values of pKa...
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