585 research outputs found

    Carvedilol Compared With Metoprolol on Left Ventricular Ejection Fraction After Coronary Artery Bypass Graft

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    A number of elective coronary artery bypass graft (CABG) surgery patients have impaired underlying left ventricular function (poor ejection fraction). This study was performed to compare the effect of postoperative oral carvedilol versus metoprolol on left ventricular ejection fraction (LVEF) after CABG compared with metoprolol. In a double-blind clinical trial, 60 patients with coronary artery disease, aged 35 to 65 years, who had an ejection fraction of 15% to 35% were included. Either carvedilol or metoprolol was administered the day after CABG The patients were evaluated by the same cardiologist 14 days before and 2 and 6 months after elective CABG The results demonstrated better improvements in LVEF in the carvedilol group. No difference regarding postoperative arrhythmias or mortality was detected. The results suggest that carvedilol may exert more of an improved myocardial effect than metoprolol for the low ejection fraction patients undergoing CABG in the early postoperative months

    Respiration, heartbeat, and conscious tactile perception

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    Previous studies have shown that timing of sensory stimulation during the cardiac cycle interacts with perception. Given the natural coupling of respiration and cardiac activity, we investigated here their joint effects on tactile perception. Forty-one healthy female and male human participants reported conscious perception of finger near-threshold electrical pulses (33% null trials) and decision confidence while electrocardiography, respiratory activity, and finger photoplethysmography were recorded. Participants adapted their respiratory cycle to expected stimulus onsets to preferentially occur during late inspiration / early expiration. This closely matched heart rate variation (sinus arrhythmia) across the respiratory cycle such that most frequent stimulation onsets occurred during the period of highest heart rate probably indicating highest alertness and cortical excitability. Tactile detection rate was highest during the first quadrant after expiration onset. Inter-individually, stronger respiratory phase-locking to the task was associated with higher detection rates. Regarding the cardiac cycle, we confirmed previous findings that tactile detection rate was higher during diastole than systole and newly specified its minimum at 250 - 300 ms after the R-peak corresponding to the pulse wave arrival in the finger. Expectation of stimulation induced a transient heart deceleration which was more pronounced for unconfident decision ratings. Inter-individually, stronger post-stimulus modulations of heart rate were linked to higher detection rates. In summary, we demonstrate how tuning to the respiratory cycle and integration of respiratory-cardiac signals are used to optimize performance of a tactile detection task

    Respiration, heartbeat, and conscious tactile perception

    Get PDF
    Previous studies have shown that timing of sensory stimulation during the cardiac cycle interacts with perception. Given the natural coupling of respiration and cardiac activity, we investigated here their joint effects on tactile perception. Forty-one healthy female and male human participants reported conscious perception of finger near-threshold electrical pulses (33% null trials) and decision confidence while electrocardiography, respiratory activity, and finger photoplethysmography were recorded. Participants adapted their respiratory cycle to expected stimulus onsets to preferentially occur during late inspiration / early expiration. This closely matched heart rate variation (sinus arrhythmia) across the respiratory cycle such that most frequent stimulation onsets occurred during the period of highest heart rate probably indicating highest alertness and cortical excitability. Tactile detection rate was highest during the first quadrant after expiration onset. Inter-individually, stronger respiratory phase-locking to the task was associated with higher detection rates. Regarding the cardiac cycle, we confirmed previous findings that tactile detection rate was higher during diastole than systole and newly specified its minimum at 250 - 300 ms after the R-peak corresponding to the pulse wave arrival in the finger. Expectation of stimulation induced a transient heart deceleration which was more pronounced for unconfident decision ratings. Inter-individually, stronger post-stimulus modulations of heart rate were linked to higher detection rates. In summary, we demonstrate how tuning to the respiratory cycle and integration of respiratory-cardiac signals are used to optimize performance of a tactile detection task

    The effect of different bleaching protocols, used with and without sodium ascorbate, on bond strength between composite and enamel

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    This in vitro study aims to evaluate whether a solution of 10% sodium ascorbate (SA) may exert a beneficial effect on the bonding of composite to enamel after using different bleaching agents and protocols. Microtensile bond strength (μTBS) was evaluated on 72 freshly extracted human central incisors, divided into eight experimental groups and one control group (total n = 9): Group 1 serves as control (nonbleached). Group 2 was bleached with 5% carbamide peroxide. Group 3 was bleached with 5% carbamide peroxide and then treated with 10% SA. Group 4 was bleached with 10% carbamide peroxide. Group 5 was bleached with 10% carbamide peroxide, then treated with 10% SA. Group 6 was bleached with 16% carbamide peroxide. Group 7 was bleached with 16% carbamide peroxide, then treated with 10% SA. Group 8 was bleached with 6% hydrogen peroxide. Group 9 was bleached with 6% hydrogen peroxide, then treated with 10% SA. All groups were restored immediately after the different treatments using a resin composite. The μTBS values were measured using a universal testing machine and statistical analysis was performed by means of normality and variance analyses, SIDAK test for univariate test and multiple comparisons, and Student test to compare μTBS values of each group with the control. The mean μTBS values in groups 2, 4, 6, 8 were significantly lower than controls. For groups 3, 5, 7, 9, subjected to antioxidant (10% SA) application, all μTBS values increased significantly. However, only for Groups 3 and 5 there was no significant difference with the control. Applying 10% SA for 10 min may improve the bond strength composite/bleached enamel just when whitening is performed with 5% and 10% carbamide peroxide

    Assessment of Readiness of Newly Graduated Health Professionals to Communicate with Patients in Duhok, Kurdistan Region, Iraq

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    Communication Skills (CS) are essential to health workforce to conduct effective professional-patient interaction. In Iraq, majority of newly graduated health professionals are engaged in provision of direct health services. However, undergraduate curricula preparing these professionals include no distinct component to train them on CS. This study aims at assessing the status of CS among Health Professions Education (HPE) graduates of University of Duhok (UoD) and estimating the perception of their patients toward those skills. This cross-sectional study was conducted in 2014. Data on communication skills was obtained, from samples of different health professionals which included: medical doctors (junior residents, nurses, dentists and pharmacists) who recently graduated from different colleges at the UoD. Also, data from was obtained, their patients, to assess their satisfaction of the professionals’ CS. For assessing core CS, a specially designed checklist was adopted from Calgary-Cambridge Guide. Also, senior clinicians were asked on CS performed by their junior residents. Results show that 88% of the senior academic staff regarded CS as “highly essential” and 66% of them were not satisfied with interns’ conduct and suggested that CS should clearly be included in the medical curricula. The basic CS were perceived by patients as either not practiced or wrongly practiced. Patients were unsatisfied with the CS of their attending HPs during observed consultation sessions. The study shows obvious lack of CS among HPE graduates of UoD with patients’ dissatisfaction of their CSs. It seems legitimate to propose that relevant training elements to be designed and incorporated within training modules are needed to realize as a core element of the curriculum of all HPE colleges at the UoD. Keywords: Communication, skills, perception, graduates, Kurdistan-Iraq. DOI: 10.7176/JHMN/73-02 Publication date: April 30th 202

    Serum C - Reactive Protein Level in Diabetic Foot Patients and Their Relation with Bacterial Isolates

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    Background: Foot infections are one of the major complications of diabetes mellitus and a significant risk factor for lower extremity amputation. C-reactive protein is an acute-phase reactant, rises dramatically in response to infection.   Aim: To determine the microbial isolates of patients with diabetic foot infections and their relation with C-reactive protein level in their sera. Materials and Methods: A prospective study of 90 patients with diabetic foot infections admitted to different public and private hospitals in Erbil city center-Iraq between June 2011 and May 2012 was undertaken. Bacteriological specimens were obtained and processed using standard procedure. The patients serum had been tested for C-reactive protein by high sensitive Enzyme linked Immunosorbent Assay (ELISA). Results: A total of 130 pathogens were isolated from 90 diabetic foot patients 46 (51%) of the patients had polymicrobial infection, 37 (41%) had single organism and 7 (8%) had no growth. Gram positive (G+ve) bacteria 60(53%) were more commonly isolated than Gram negative (G-ve) bacteria 53(47%). Staphylococcus aureus and Escherichia coli were the most frequently among G+ve and G-ve isolates respectively. No significant difference was found between mean serum levels of C-reactive protein in patients infected with G+ve bacteria versus G-ve bacteria, although their concentration was more in the later. However, highly significant differences (P<0.01) were observed between both G+ve and G-ve bacteria versus no bacterial isolate in patients. Conclusion: C-reactive protein serum level was higher in patient with diabetic foot infected by G-ve bacteria, although G+ve bacteria represented a major bacterial isolates.

    Investigation into the characteristics of proton exchange membrane fuel cell-based power system

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    © The Institution of Engineering and Technology.Fuel cells (FCs) use hydrogen as their prime fuel source, which promotes them as one of the attractive options for clean energy generators. Though they have been around for some time, their characteristics are not yet fully understood. This study offers a thorough investigation into the characteristics of proton exchange membrane (PEM) type of FCs based power system. This study first presents a concise explanation of the working principles of the PEM electrolyser and FCs supported by novel modelling using MATLAB. The simulation results are then validated by a series of experiments carried out on operational 500 mW FC followed by detailed performance parameters of such type of FCs. Parameters affect the efficiencies of each part of the system are investigated and the total system's efficiency is then calculated. The efficiency of the electrolyser and PEM FC was found to be 85 and 60%, respectively. Polarisation curve has been used in order to evaluate FC's performance. From the polarisation curve, it is noted the efficiency of the FC increases with increasing pressure and temperature. The activation losses are reduced when the temperature increased. Moreover, the mass transfer is enhanced toward reducing the PEMFC's resistance
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