39 research outputs found

    Evaluation of atrial electromechanical conduction delay in case of hemodynamically insignificant rheumatic heart disease: A tissue Doppler study

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    Background: Atrial electromechanical delay (AEMD) that reflects delayed conduction may show us the clinical reflection of pathological changes in the atria. The main objective of the present study is to investigate AEMD in patients who had previous rheumatic carditis but without hemodynamically significant valvular disease. Methods: A total of 40 patients, previously diagnosed as rheumatic carditis but without significant valvular stenosis/regurgitation and atrial enlargement; and 39 age- and-sex matched controls were enrolled for the present study. Parameters of AEMD (lateral mitral annulus electromechanical delay, septal mitral annulus electromechanical delay and lateral tricuspid annulus electromechanical delay) were measured with tissue Doppler echocardiography and left intra-atrial and inter-atrial conduction times were calculated accordingly. A 24h ambulatory Holter monitoring was used in both groups to detect atrial fibrillation episodes and quantify atrial extrasystoles. Results: Parameters of AEMD, including left intra-atrial and inter-atrial conduction times of subjects in the study group were longer compared to the control group (23.7 ± 7.0 vs. 18.3 ± 6.2). Conclusions: Increased AEMD is observed in patients with previous rheumatic carditis and no significant valvular stenosis/regurgitation and atrial enlargement, which may partly explain the increased incidence of atrial fibrillation observed in these patients

    Thermal management of electric vehicle battery cells with homogeneous coolant and temperature distribution

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    WOS: 000542961200001Electric vehicles play an integral role in eliminating pollution related to transportation, especially if the electricity is generated via renewable sources. However, storing electricity onboard requires many battery cells. If the temperature of the cells is not strictly regulated, their capacity decreases in time, and they may burn or explode due to thermal runaway. Battery thermal management systems emerged for safe operations by keeping the battery cell temperatures under limit values. However, the current solutions do not yield uniform temperature distribution for all the cells in a pack. Here, we document that constant temperature distribution can be achieved with uniform coolant distribution to the channels located between batteries. The design process of the developed battery pack begins with a design used in current packs. Later, how the shape of the distributor channel affects flow uniformity is documented. Then, the design complexity was increased to satisfy the flow uniformity condition, which is essential for temperature uniformity. The design was altered based on a constructal design methodology with an iterative exhaustive search approach. The uncovered constructal design yields a uniform coolant distribution with a maximum of 0.81% flow rate deviation along channels. The developed design is palpable and easy to manufacture relative to the tapered manifold designs. The results also document that the peak temperature difference between the cells decreases from a maximum of 12K to 0.4K. Furthermore, homogenous distribution of air is one of the limiting factors of the development of metal-air batteries. This paper also documents how air can be distributed uniformly to metal-air battery cells in a battery pack

    A case of anomalous origin of circumflex artery from right sinus of valsalva recognized by three-dimensional transesophageal echocardiography and coronary computed tomography angiography

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    Anomalous origin of the circumflex coronary artery from the right sinus of Valsalva is the most common coronary anomaly. It is thought to be of no clinical relevance unless cardiac surgery is performed. We report a 53-year-old patient with aberrant circumflex coronary artery origin from the right aortic sinus of Valsalva which was first suspected from transthoracic 2D and transesophageal 3D echocardiographic views and confirmed by coronary CT angiography. The patient did not receive further diagnostic or therapeutic options. Therefore, we recommended medical therapy with optimal treatment of his cardiovascular risk factors together with regular clinical follow up

    Utilizing aluminum etching wastewater for tannery wastewater coagulation: performance and feasibility

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    2nd International Conference on Recycling and Reuse -- JUN 04-06, 2014 -- Istanbul, TURKEYThe main objective of this study was to investigate the feasibility of utilizing etching wastewater (EW) of aluminum (Al) coating industry as an alum substitute in industrial wastewater treatment. Our hypothesis was that Al-rich EW could be an effective substitute for commercial liquid alum used in a nearby (<10km) tannery wastewater treatment plant (Corlu, Turkey). Bench-scale alum and EW jar tests along with an economic analysis were performed to test this hypothesis. Jar test results conducted using identical pH and Al doses showed that Al-rich EW performed similar to alum in terms of chemical oxygen demand (COD), suspended solids (SS), and turbidity removal. Regardless of its origin (alum or EW), 1 g of Al approximately removed 30g COD and 20g SS via a combined effect of coagulation and plain settling. Commercial alum and EW removed more than 95% of COD and turbidity; 60% of total COD from the tannery wastewater. Preliminary cost analysis showed that coagulant expenditure could be reduced by 40% if alum was substituted with EW.Namik Kemal UniversityNamik Kemal UniversityThe authors would like to thank Namik Kemal University for technical assistance and financial support for this research project. We would like to thank three anonymous reviewers for their invaluable comments, which improved an earlier version of the manuscript

    Knowledge and attitudes towards hypertriglyceridaemia and associated residual risk amongst cardiologists in Turkey

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    BACKGROUND: Hypertriglyceridemia (HTG) is an important component of residual risk. The knowledge regarding its treatment might not be at a desired level which might prevent patients from receiving the maximum benefit. We aimed to investigate the knowledge and attitudes of Turkish cardiologists who responded to a survey regarding HTG treatment

    Packet Size Optimization in Wireless Sensor Networks for Smart Grid Applications

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    Wireless sensor networks (WSNs) are envi-sioned to be an important enabling technology for smart grid (SG) due to the low cost, ease of deployment, and versatility of WSNs. Limited battery energy is the tightest resource constraint on WSNs. Transmission power control and data packet size optimization are powerful mechanisms for prolonging network lifetime and improving energy effi-ciency. Increasing transmission power will reduce the bit error rate (BER) on some links, however, utilizing the high-est power level will lead to inefficient use of battery energy because on links with low path loss achieving low BER is possible without the need to use the highest power level. Utilizing a large packet size is beneficial for increasing the payload-to-overhead ratio, yet, lower packet sizes have the advantage of lower packet error rate. Furthermore, trans-mission power level assignment and packet size selection are interrelated. Therefore, joint optimization of transmission power level and packet size is of utmost importance in WSN lifetime maximization. In this study, we construct a de-tailed link layer model by employing the characteristics of Tmote Sky WSN nodes and channel characteristics based on actual measurements of SG path loss for various envi-ronments. A novel mixed integer programming framework is created by using the aforementioned link layer model for WSN lifetime maximization by joint optimization of trans-mission power level and data packet size. We analyzed the WSN performance by systematic exploration of the parameter space for various SG environments through the numer-ical solutions of the optimization model.The work of V. C. Gungor was supported by the Turkish National Academy of Sciences Distinguished Young Scientist Award Program (TUBA-GEBIP) under Grant V.G./TBA-GEBP/2013-14

    Oocyte pick up day mucus removal: Does it have a positive effect on pregnancy rates?

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    Aim: Mucus removal that would be done on the day of embryo transfer could be done on Oocyte pick up(OPU) day, and this practice might be related with better pregnancy rates since it is unlikely to cause uterine contractions during the embryo transfer. We compared the effects of mucus removal done on OPU day, transfer day or no removal at all on success rates of the treatment in three groups. Material and Method: We designed a prospective match control study. There were 131 cycles in which mucus removal was done on either OPU day or embryo transfer day (64 and 67 cycles respectively) and in 411 cycles mucus removal was not done, and these patients constituted the control group. Results: After mucus removal on OPU day, mucus removal on embryo transfer day and no mucus removal done at all, pregnancy rates were calculated as 40,6%, 29,9%, and 23,1% respectively and the difference among the groups was statistically significant (p=0,009). Discussion: Mucus removal on OPU day or on embryo transfer day improves pregnancy rates. It can be included in the routine practice, since it may potentially minimize cervical trauma and uterine contractions and thus improve success in IVF/ICSI treatments

    Aggressive Angiomyxoma of the Pelviperineum: Surgical Treatment through a Perineal Incision

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    Aggressive angiomyxoma is a rare benign tumor of the pelvic soft tissue in women of reproductive age. The tumor is locally infiltrative and tends to recur. Herein is presented a case report of aggressive angiomyxoma that was totally excised using a transperineal approach. A 35-year-old woman had an aggressive angiomyxoma of the vulva and pelvis, with swelling of the right labium majus pudendi. Three years previously, she had undergone incomplete excision of the same type of pelviperineal mass via the transabdominal route. After a complete workup, a transperineal minimally invasive approach was used to excise the 20-cm mass filling the right side of the pelvis. Histopathologic findings were consistent with a diagnosis of aggressive angiomyxoma. Although often misdiagnosed as various other benign genital disorders, angiomyxoma usually is manifested as a soft nontender mass. After a thorough examination and full radiologic workup, a small transperineal incision may be sufficient for complete removal of the tumor. Journal of Minimally Invasive Gynecology (2011) 18, 541-544 (C) 2011 AAGL. All rights reserved
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