154 research outputs found

    Fuchs Heterochromic Iridocyclitis-Associated Glaucoma: A Retrospective Comparison of Primary Ahmed Glaucoma Valve implantation and Trabeculectomy with MMC

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    Purpose: To compare the safety and efficacy of a primary trabeculectomy with mitomycin C (T) and an Ahmed glaucoma valve (AGV) implantation in patients with Fuchs heterochromic iridocyclitis (FHIC) related glaucoma, a rare complication of an uncommon form of uveitis. Design: Retrospective comparative case series. Method: Twenty-six patients with uncontrolled FHIC-associated glaucoma received T (n=12) or an AGV (n=14). Primary outcome measures were the surgical success defined as IOP ≤ 21 mmHg and decreased ≥ 20% from the baseline and no secondary glaucoma surgery. Secondary outcome measures were the number of glaucoma medications, complications, best corrected visual acuity (BCVA), and intraocular pressure. Results: The follow-up (mean±SD) was 34.0±17.7 in T and 33.4±18.6 months in AGV (p = 0.837). The cumulative probability of success rate at the final follow-up at three years was 41.7% for T and 85.7% for AGV. There was no significant difference in complications between the two groups (P>0.05). The mean preoperative IOP in T was 23.4±3.3 mmHg and 21.6±5.2 mmHg at the final visit (P= 0.041). In AGV, the preoperative IOP was 24±7.8 and 17.1±2.6 mmHg at the final visit (P= 0.003), respectively. AGV had a significantly lower average IOP at the final follow-up visit compared to T (P= 0.018). The number of glaucoma medications at baseline was 3.3±0.5 in T and 3±0.6 in AGV (P= 0.233). This decreased significantly to 2.4±1.0 and 1.7±0.6 at the final follow-up (P= 0.008 and 0.002, respectively). Patients in AGV needed fewer glaucoma medications (P= 0.041). BCVA was equal in both groups and did not change (p>0.05). Conclusion: Primary AGV had a higher success rate than T in the management of FHIC-associated glaucoma. The risk of cataract formation and progression was significantly higher following T in these patients

    Scottish and Newcastle antiemetic pre-treatment for paracetamol poisoning study (SNAP)

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    BACKGROUND: Paracetamol (acetaminophen) poisoning remains the commonest cause of acute liver injury in Europe and North America. The intravenous (IV) N-acetylcysteine (NAC) regimen introduced in the 1970s has continued effectively unchanged. This involves 3 different infusion regimens (dose and time) lasting over 20 hours. The same weight-related dose of NAC is used irrespective of paracetamol dose. Complications include frequent nausea and vomiting, anaphylactoid reactions and dosing errors. We designed a randomised controlled study investigating the efficacy of antiemetic pre-treatment (ondansetron) using standard NAC and a modified, shorter, regimen. METHODS/DESIGN: We designed a double-blind trial using a 2 × 2 factorial design involving four parallel groups. Pre-treatment with ondansetron 4 mg IV was compared against placebo on nausea and vomiting following the standard (20.25 h) regimen, or a novel 12 h NAC regimen in paracetamol poisoning. Each delivered 300 mg/kg bodyweight NAC. Randomisation was stratified on: paracetamol dose, perceived risk factors, and time to presentation. The primary outcome was the incidence of nausea and vomiting following NAC. In addition the frequency of anaphylactoid reactions and end of treatment liver function documented. Where clinically necessary further doses of NAC were administered as per standard UK protocols at the end of the first antidote course. DISCUSSION: This study is primarily designed to test the efficacy of prophylactic anti-emetic therapy with ondansetron, but is the first attempt to formally examine new methods of administering IV NAC in paracetamol overdose. We anticipate, from volunteer studies, that nausea and vomiting will be less frequent with the new NAC regimen. In addition as anaphylactoid response appears related to plasma concentrations of both NAC and paracetamol anaphylactoid reactions should be less likely. This study is not powered to assess the relative efficacy of the two NAC regimens, however it will give useful information to power future studies. As the first formal randomised clinical trial in this patient group in over 30 years this study will also provide information to support further studies in patients in paracetamol overdose, particularly, when linked with modern novel biomarkers of liver damage, patients at different toxicity risk. TRIAL REGISTRATION: EudraCT number 2009-017800-10, ClinicalTrials.gov IdentifierNCT0105027

    The prevalence of glaucoma in Tehran, Iran

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    Purpose: To determine the prevalence of glaucoma in adults 40 years of age or older in Tehran, Iran. Methods: This stratified random-sampling cross-sectional population survey was performed on residents of Tehran, the capital of Iran, aged 40 years and older in the year 2001. Refraction, best-corrected visual acuity, slitlamp biomicroscopy, Goldmann applanation tonometry, funduscopy, and gonioscopy were performed in all subjects. Automated perimetry was performed in selected cases. Results: Out of 4418 sampled subjects, 2184 individuals (49.4) participated in the survey. Eventually data from 2160 individuals including 814 (38) male and 1346 (62) female subjects with mean age of 55.1±10.2 (range 40-92) years were analyzed. The overall prevalence of glaucoma was 1.44 (95 confidence interval, 0.94-1.94) including primary open angle glaucoma 0.46, chronic angle closure glaucoma 0.33, normal tension glaucoma 0.28, pseudoexfoliation glaucoma 0.23, and other types of glaucoma 0.14. More than 80 of affected subjects were unaware of their condition. Conclusion: The prevalence of glaucoma in adults 40 years of age or older in Tehran is 1.44, which is in the lower range reported in other populations. The large majority of cases are unaware of their condition

    Continence technologies whitepaper: Informing new engineering science research

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    Advances in healthcare technology for continence have historically been limited compared to other areas of medicine, reflecting the complexities of the condition and social stigma which act as a barrier to participation. This whitepaper has been developed to inspire and direct the engineering science community towards research opportunities that exist for continence technologies that address unmet needs in diagnosis, treatment and long-term management. Our aim is to pinpoint key challenges and highlight related research opportunities for novel technological advances. To do so, we draw on experience and expertise from academics, clinicians, patients and patient groups linked to continence healthcare. This is presented in four areas of consideration: the clinical pathway, patient perspective, research challenges and effective innovation. In each we introduce seminal research, background information and demonstrative case-studies, before discussing their relevance to engineering science researchers who are interested in approaching this overlooked but vital area of healthcare

    A review of communication-oriented optical wireless systems

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    Ageing condition of tensile specimens: fracture behavior of notched Al2024 sheet under tensile loading

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    The effect of different (T6 and T8) heat treatments on tensile properties and fracture behavior of Al2024 in presence and absence of notch by means of microhardness, tensile tests and scanning electron microscopy were investigated. Tensile and hardness specimens were subjected to two different artificial ageing (T6 and T8 heat treatment) for various times. These included under ageing (UA), peak ageing (PA) and over ageing (OA). T8 heat treatment, which has a cold rolling between solutionizing and ageing in its steps, showed a higher value of hardness and yield strength in comparison with common artificial ageing of T6 heat treatment. In notched-tensile specimens, yield stress was found to increase up to the peak ageing condition with a simultaneously decrease in elongation at fracture. This behavior was converse at OA condition. Although introducing of notch increase the yield stress of samples under T6 and T8 conditions in comparison with un-notched samples, the notch strengthening phenomenon was observed only under T8 treatment. Despite of an enhancement in strengthening by applying notch on tensile samples, the elongation to failure was notably lessen in both notched-heat treated samples in comparison with un-notches ones. Also, it was confirmed that the toughness of notched samples of both heat treatments at PA condition were significantly lower than un-notched ones. Consequently, toughness decrement was considerably dominated by the role of deformability compared to strengthening factor, however, the presence of cold rolling in the process of heat treatment (T8) could reduce the harmful effects of notch by increasing the stress bearing capacity in contrary with T6 heat treatment. Moreover, inserting the mechanical properties of peak aged samples from the un-notched tensile test in Abaqus finite element software; the V-shaped notch tensile test was simulated and confirmed the experimental results. It was shown in SEM results that the presence of notch enhanced the contribution of cracked particles, compared to particle/matrix deboning and matrix deformation, therefore, the non-homogeneous distribution of fracture features confirmed the harmful effect of notch. In the following, the distribution of three fracture micro-mechanisms were homogeneous in un-notched samples, which demonstrated the superior values of toughness in smooth samples. The present finding sheds light on development of processing techniques to optimize the mechanical properties of Al 2024 alloy

    Dose enhancement in brachytherapy in the presence of gold nanoparticles : a Monte Carlo study on the size of gold nanoparticles and method of modelling

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    The aim of this study was to evaluate the effect of the size of gold nanoparticles (GNPs) on dose enhancement in brachytherapy with photon emitting sources. Four photon emitting sources, 125I, 169Yb, 103Pd, and 192Ir were simulated and dose rate constant and radial dose functions were compared with published corresponding data for these sources. Dose enhancement factor in the presence of gold nanoparticles of 30 mg/ml concentration was calculated separately for nanoparticles with a diameter of 50, 100 and 200 nm. Gold nanoparticles were simulated precisely as nanospheres utilizing a lattice option in the MCNPX Monte Carlo code and the results were compared with those obtained with a simple model in which gold atoms are distributed uniformly in tumor volume as a simple mixture. Among the four mentioned sources, the dose enhancement related to 125I source is higher. Our results have shown that with gold nanoparticles of higher diameter, the level of dose enhancement is higher in the tested tumor. It has been also observed that the simple model overestimates the dose enhancement factor when compared with the precise model in which nanoparticles are defined according to the Monte Carlo code. In the energy range produced by the brachytherapy sources, the dose enhancement is higher when using brachytherapy sources with lower energy. Among the size range of gold nanoparticles used in medicine, it is predicted that nanoparticles with higher diameter can be more useful when are utilized in brachytherapy. It is also recommended that when calculating dose enhancements, a precise model be used for modelling of nanoparticles in the Monte Carlo simulations
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