45 research outputs found

    EEG-Based Neurocognitive Metrics May Predict Simulated and On-Road Driving Performance in Older Drivers

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    The number of older drivers is steadily increasing, and advancing age is associated with a high rate of automobile crashes and fatalities. This can be attributed to a combination of factors including decline in sensory, motor, and cognitive functions due to natural aging or neurodegenerative diseases such as HIV-Associated Neurocognitive Disorder (HAND). Current clinical assessment methods only modestly predict impaired driving. Thus, there is a need for inexpensive and scalable tools to predict on-road driving performance. In this study EEG was acquired from 39 HIV+ patients and 63 healthy participants (HP) during: 3-Choice-Vigilance Task (3CVT), a 30-min driving simulator session, and a 12-mile on-road driving evaluation. Based on driving performance, a designation of Good/Poor (simulator) and Safe/Unsafe (on-road drive) was assigned to each participant. Event-related potentials (ERPs) obtained during 3CVT showed increased amplitude of the P200 component was associated with bad driving performance both during the on-road and simulated drive. This P200 effect was consistent across the HP and HIV+ groups, particularly over the left frontal-central region. Decreased amplitude of the late positive potential (LPP) during 3CVT, particularly over the left frontal regions, was associated with bad driving performance in the simulator. These EEG ERP metrics were shown to be associated with driving performance across participants independent of HIV status. During the on-road evaluation, Unsafe drivers exhibited higher EEG alpha power compared to Safe drivers. The results of this study are 2-fold. First, they demonstrate that high-quality EEG can be inexpensively and easily acquired during simulated and on-road driving assessments. Secondly, EEG metrics acquired during a sustained attention task (3CVT) are associated with driving performance, and these metrics could potentially be used to assess whether an individual has the cognitive skills necessary for safe driving

    Radiographic knee osteoarthritis in ex-elite table tennis players

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    <p>Abstract</p> <p>Background</p> <p>Table tennis involves adoption of the semi-flexed knee and asymmetrical torsional trunk movements creating rotational torques on the knee joint which may predispose players to osteoarthritis (OA) of the knee. This study aims to compare radiographic signs of knee OA and associated functional levels in ex-elite male table tennis players and control subjects.</p> <p>Methods</p> <p>Study participants were 22 ex-elite male table tennis players (mean age 56.64 ± 5.17 years) with 10 years of involvement at the professional level and 22 non-athletic males (mean age 55.63 ± 4.08 years) recruited from the general population. A set of three radiographs taken from each knee were evaluated by an experienced radiologist using the Kellgren and Lawrence (KL) scale (0-4) to determine radiographic levels of OA severity. The intercondylar distance was taken as a measure of lower limb angulation. Participants also completed the pain, stiffness, and physical function categories of the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) 3.1 questionnaire.</p> <p>Results</p> <p>The results showed 78.3% of the ex-elite table tennis players and 36.3% of controls had varying signs of radiographic knee OA with a significant difference in the prevalence levels of definite radiographic OA (KL scale > 2) found between the two groups (<it>P </it>≤ 0.001). Based on the WOMAC scores, 68.2% of the ex-elite table tennis players reported symptoms of knee pain compared with 27.3% of the controls (<it>p </it>= 0.02) though no significant differences were identified in the mean physical function or stiffness scores between the two groups. In terms of knee alignment, 73.7% of the ex-elite athletes and 32% of the control group had signs of altered lower limb alignment (genu varum) (<it>p </it>= 0.01). Statistical differences were found in subjects categorized as having radiographic signs of OA and altered lower limb alignment (<it>p </it>= 0.03).</p> <p>Conclusions</p> <p>Ex-elite table tennis players were found to have increased levels of radiological signs of OA in the knee joint though this did not transpire through to altered levels of physical disability or knee stiffness in these players when compared with subjects from the general population suggesting that function in these players is not severely impacted upon.</p

    Experimental investigation of heat transfer and friction coefficient of the water/graphene oxide nanofluid in a pipe containing twisted tape inserts under air cross-flow

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    The water/graphene oxide nanofluid effect in a pipe equipped by twisted tape inserts under air cross-flow is investigated and the optimal tape geometry is determined. The range of internal and external Reynolds numbers are: 3800&lt;21500 and 550&lt;2000. Heat transfer and pressure drop increase by increasing Re and inserts width and heat transfer performance coefficient increased up to 1.4, indicating enhanced heat transfer compared to undesirable pressure drop. On the other hand, the heat transfer coefficient is 26% higher when compared with water in a plain tube. According to the results, this method is a good alternative in heat exchangers

    Investigation of the prevalence of genes conferring resistance to carbapenems in Pseudomonas aeruginosa isolates from burn patients

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    Azar Dokht Khosravi,1,2 Shahab Taee,3 Aram Asarehzadegan Dezfuli,1 Hossein Meghdadi,2 Fatemeh Shafie21Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; 2Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; 3Department of Biology, Faculty of Basic Sciences, Yasouj Branch, Islamic Azad University, Yasouj, IranBackground and aim: Currently, the rate of hospital-acquired infections due to drug-resistant Pseudomonas aeruginosa strains shows an increasing trend and remains one of the principal reasons for mortalilty in burn patients. This study aimed to investigate the prevalence of genes conferring resistance to carbapenems in P. aeruginosa isolates from burn patients.Methods: A total of 50 P. aeruginosa isolates were tested for antibiotic susceptibility and presence of multidrug-resistant (MDR) and extensively drug resistant (XDR) isolates, using phenotypic tests. Screening for genes conferring resistance to carbapenems was investigated by multiplex PCR method.Results: Susceptibility testing demonstrated the highest resistance against amikacin, ceftazidime (n=44/88% each), and gentamicin (84%), while colistin sulfate was the most effective antibiotic. The rate of MDR and XDR isolates was revealed as 50% and 40% respectively. We detected the following carbapenemase genes: blaNDM (32%), followed by blaOXA-48 (18%), and blaBIC-1 (14%). This study revealed a high antibiotic resistance in P. aeruginosa isolates with a total of 40% and 50% MDR and XDR isolates respectively, and 70% carbapenem resistance. The prevalence of carbapenem conferring genes tested among carbapenem-resistant isolates was demonstrated as 65.7%.Conclusion: Due&nbsp;to the prevalence of P. aeroginosa strains carrying blaOXA-48 and blaNDM genes in our hospital, more attention and implementation of effective control measures against nosocomial infection are recommended.Keywords: Pseudomonas aeruginosa, carbapenems, encoding genes, antibiotics, drug susceptibility tes

    An experimental study on heat transfer and pressure drop of water/graphene oxide nanofluid in a copper tube under air cross-flow: Applicable as a heat exchanger

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    The effect of using water/graphene oxide nanofluid as a working fluid on heat transfer and pressure drop was studied experimentally. For this purpose, subsonic wind tunnel and a closed heat transfer cycle were used at the same time. The effect of different concentrations (0, 0.05, 0.1, 0.2% by volume) of water/graphene oxide nanofluid at different Reynolds numbers in a tube under air cross-flow was evaluated in wind tunnel tests. The range of Reynolds number of the flow around the tube was between 3800 and 21500 3800⩽Reo⩽21500. The friction factor of the nanofluid flow inside the tube and the mean Nusselt number of the external air flow around the copper tube were calculated by measuring the variables. Results showed that by using water/graphene oxide nanofluid, the average Nusselt number enhanced by up to 51.4% compared to pure water. The use of nanofluid increased the friction factor by 21% in comparison with pure water. Because of changes in heat transfer and friction factor, heat transfer performance coefficient increased by up to 42.2%, indicating enhanced heat transfer compared to undesirable pressure drop in the test. According to the results, this nanofluid can be a good alternative in similar applications such as heat exchangers

    Synthesis, X-ray structure, electrochemistry, and theoretical studies of palladium(II) complex with a tetradentate bis(quinoline-2-carboxamide) ligand

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    The title complex [Pd(Me(2)bqb)] (1), [Me(2)bqb(2-) = 1,2-bis(quinoline-2-carboxamide)-4,5-dimethyl-benzene dianion], has been synthesized and characterized by elemental analyses and spectroscopic methods, and the crystal and molecular structure of [Pd(Me(2)bqb)] has been determined by X-ray crystallography. The complex exhibits distorted square-planar PdN4 coordination geometry with two short and two long Pd-N bonds (Pd-N similar to 1.957 and similar to 2.095 angstrom, respectively). In addition to the molecular geometry from X-ray experiment, theoretical studies have been carried out on the structure of the complex at the density functional theory (DFT-B3LYP) level in conjunction with effective core potential basis set (LANL2DZ) for Pd atom and 6-311++G(d,p) basis set for N, O, C and H atoms. Electrochemical studies in CH2Cl2 solution revealed A reversible redox process corresponding to the Pd-II/Pd-III couple with E (1/2) at 0.924 V (vs. SCE)
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