Publications by authors named "Jawad Saleem"

3 Publications

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Investigation of 9000 hours multi-stress aging effects on High-Temperature Vulcanized Silicone Rubber with silica (nano/micro) filler hybrid composite insulator.

PLoS One 2021 28;16(7):e0253372. Epub 2021 Jul 28.

Manchester Metropolitan University, Manchester, United Kingdom.

Degradation in the polymeric insulators is caused due to the environmental stresses. The main aim of this paper is to explore the improved aging characteristics of hybrid samples by adding nano/micro silica in High Temperature Vulcanized Silicone Rubber (HTV-SiR) under long term accelerated aging conditions for 9000 hours. As HTV-SiR is unable to sustain environmental stresses for a long time, thus a long term accelerated aging behavior is an important phenomenon to be considered for field application. The aging characteristics of nano/micro filled HTV-SiR are analyzed by using techniques such as Scanning Electron Microscopy (SEM), Leakage Current (LC), Fourier Transform Infrared Microscopy (FTIR), Hydrophobicity Classification (HC), and breakdown strength for the aging time of 9000 hours. FTIR and leakage currents are measured after every cycle. All the co-filled samples revealed escalated aging characteristics as compared to the neat sample except the SN8 sample (8% nano-silica+20% micro-silica) after 9000 hours of aging. The highest loading of 6% and 8% nano-silica with 20% micro-silica do not contribute to the improved performance when compared with the neat and hybrid samples. However, from the critical experimental analysis, it is deduced that SN2 sample (2% nano-silica+20% micro-silica) is highly resistant to the long term accelerated aging conditions. SN2 has no cracks, lower loss percentages in the important FTIR absorption peaks, higher breakdown strength and superior HC after aging as compared to the unfilled and hybrid samples.
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July 2021

Hyperoxia After Return of Spontaneous Circulation in Cardiac Arrest Patients.

J Cardiothorac Vasc Anesth 2021 Mar 8. Epub 2021 Mar 8.

Department of Anesthesiology and Perioperative Medicine, University of Louisville, Louisville, KY; Department of Cardiovascular and Thoracic Surgery, University of Louisville, Louisville, KY.

Current guidelines emphasize the use of 100% oxygen during cardiopulmonary resuscitation after cardiac arrest. When patients are ventilated for variable periods after return of spontaneous circulation (ROSC), hyperoxia causes increased morbidity and mortality by overproduction of reactive oxygen species. Various patient, volunteer, and animal studies have shown the harmful effects of hyperoxia. This mini-review article aims to expand the potential clinical spectrum of hyperoxia on individual organ systems leading to organ dysfunction. A framework to achieve and maintain normoxia after ROSC is proposed. Despite the harmful considerations of hyperoxia in critically ill patients, additional safety studies including dose-effect, level and onset of the reactive oxygen species effect, and safe hyperoxia applicability period after ROSC, need to be performed in various animal and human models to further elucidate the role of oxygen therapy after cardiac arrest.
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March 2021

Iliofemoral pulsion endarterectomy.

Ann Vasc Surg 2009 Mar 9;23(2):259-63. Epub 2008 Aug 9.

Department of Vascular Surgery, University Hospital Birmingham, NHS Foundation Trust, Birmingham, UK.

We present our experience with a technique of endarterectomy for use in patients with iliofemoral occlusive disease, in which the atheromatous plug is extruded from the intact artery by external manipulation (pulsion). A retrospective review of consecutive patients who underwent surgical iliofemoral pulsion endarterectomy (IFPE) in two vascular surgery units between 1998 and 2006 was performed. Primary and secondary graft patency, limb salvage, and patient survival rates were determined using Kaplan-Meier methods. Fifty-eight IFPEs were carried out successfully on 54 patients (36 men, 18 women, median age 66 years) presenting with critical limb ischemia (n=23), with claudication (n=29), or in conjunction with abdominal aortic aneurysm repair (n=6). Mean (range) follow-up was 17 months (1-69). During this period six patients (all male, mean age 64 years) underwent iliofemoral bypass using a prosthetic graft when the iliac arteries were found unsuitable for endarterectomy because of hypoplasia or heavy calcification. Two-year cumulative primary patency of IFPE was 95%, secondary patency 100%, limb salvage 98.5%, and patient survival 73%. This modification of iliac endarterectomy is a relatively simple and safe technique that eschews prosthetics and offers a durable solution for the majority of patients with extensive iliofemoral occlusive disease.
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March 2009