296 research outputs found

    A simple heart valve replacement technique which improves surgical time

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    Aim of the study: Different heart valve replacement techniques have been described in the literature. In the present study, a simple and very fast heart valve replacement technique is presented. Material and methods: In a two-year period, 87 patients with the diagnosis of mitral valve disease, aortic valve disease or combined valve disease underwent valve replacement performed by the same surgeon. In this technique, the valve was implanted with the valve clamped to the surgical dressing without the assistant holding it. Patients with coexisting surgical pathologies were excluded from the study. A control group was created among the patients who were operated on during the same time period by different surgeons with the assistant holding the prosthesis. Control group operations were done by conventional valve holding and suturing techniques. Results: Mean age of the patients was 61.6 ± 3.2 years. Mitral valve replacement (MVR) was done to 51 patients, aortic valve replacement (AVR) to 12 patients and both aortic and MVR to 24 patients. Aortic cross clamp duration was 30.7 ± 3.3 min for MVR, 34.8 ± 6.2 min for AVR and 69.1 ± 6.1 min for both valve replacements. Aortic clamping durations were significantly higher in the conventional implantation technique. Discussion: The described technique has many advantages such as short myocardial ischemia duration, better exposure of the surgical field and facilitation of assistance. © 2014 Termedia Sp. z o.o. All rights reserved

    The Relationship between Authentic Leadership and Employees' Virtual Loafing and Cynic Behaviors

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    The main purpose of this study is to investigate whether the managers’ authentic leadership styles affect employees’ organizational cynicism and virtual loafing behavior. The sample of the study consists of 208 administrative staff at Ahi Evran University. According to the results of the study, it is clear that the authentic leadership reduces organizational cynicism and does not reduce the virtual loafing; and organizational cynicism behaviors have an increasing effect on virtual loafing. Sample of the research consists of administrative personnel working at Ahi Evran University located in Kırşehir. First of all, descriptive statistics, correlation, and hierarchical regression analyses were conducted related to the hypotheses tests. The results of these analyses revealed that a negative relationship existed between authentic leadership and organizational cynism, while there was a positive relationship between organizational cynism and virtual loafing. Moreover, no negative relation was found between authentic leadership and virtual loafing, which was one of the hypotheses of the research

    New Bryophyte Records from Turkey and Southwest Asia

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    Five bryophytes collected during bryological forays to the Ordu and Burdur regions of Turkey were of particular interest. Among them, Orthotrichum hookeri, Plagiothecium neckeroideum and Thamnobryum neckeroides were found to be new to Turkey. Orthotrichum hookeri and Plagiothecium neckeroideum are also new to Southwest Asia. Descriptions, illustrations, ecology, geographic distribution and comparisons with morphologically similar taxa are presented. Two species, Hookeria acutifolia and Orthotrichum sordidum, were recorded only for the second time in Turkey

    Çokal Barajı (Çanakkale) çökme modeli ve taşkın risk analizi

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    The source of the hazard which is the main factor of disasters can be made by naturally or man. These are generally independent sources, but sometimes reason of one hazard such as flood can be both naturally and man-made. Certainly, all examples in our country and the world show that, the fail of constructed structures on the rivers (e.g. dam, embankment) produce a very large amount of water and damage more than the normal river floods. In this study, based on cofferdam of Çokal Dam breaching which occurred in 16 November 2007 on the Kavak River (Çanakkale), 1D modeling of probable Çokal Dam break take in the account tectonic properties of the area and analyzing of the flood risk have been done. For these purposes, Digital Elevation Model (DEM) gathered contours from 1:25000 scaled topographic maps and GPS points, high and medium resolution satellite images, hydrological soil data gathered from soil maps scaled 1:25000, precipitation and discharge data in 30 years, technical properties of structures on the Kavak River and field measurement have been used as a database. All these data is processed and analyzed using Geographic Information System (GIS), Hec-GeoRAS and HEC-RAS hydraulic models and hydrologic model. Hence, Çokal Dam break modeling based on cofferdam breach modeling reveals that probable flood after the dam-break will affect Evreşe Plain and the people which get livelihood from the plain. General probable lost in agricultural product after probable flood reaches TL 12 million. Thus, as a result of human interventions to the nature will cause great harm to himself again.   Afetlerin oluşmasında önemli etkiye sahip tehlikeler, doğa kaynaklı olabildikleri gibi insan kaynaklı da olabilmektedir. Bunlar genelde birbirinden bağımsız tehlike türleri iken bazen taşkınlar gibi kaynağını hem doğadan hem insandan alan tehlikeler olarak da karşımıza çıkmaktadır. Şüphesiz ki ülkemizdeki ve dünyadaki örneklerin tamamı ortaya koymuştur ki, insan kaynaklı olarak akarsular üzerine inşaa edilen yapıların (baraj, set vb.) bir şekilde zarar görmesiyle sonuçları normal taşkınlardan da fazla olmuştur. Bu çalışmada, 16 Kasım 2007'de Kavak Deresi (Çanakkale) üzerindeki Çokal Barajı menba batardosunda meydana gelen çökmenin oluşturduğu taşkına bağlı olarak, günümüz itibariyle halen yapımına devam edilen Çokal Barajı'nın sahanın tektonik özellikleri de gözönünde tutularak, olası çökmesinin tek boyutlu (1D) hidrolik modellemesi yapılmış ve buna bağlı taşkın risk analizi gerçekleştirilmiştir. Çalışmada altlık verileri, 1:25000 ölçekli topografik eşyükselti eğrisi ve saha GPS verileriyle üretilmiş Sayısal Yükselti Modeli (SYM), yüksek ve orta çözünürlüklü uydu görüntüleri, hidrolojik toprak  verileri, 30 yıllık yağış ve akım verileri, Kavak Dere üzerindeki yapılara ait teknik özellikler ve arazi ölçümleri oluşturmaktadır. Bütün bu altlık veriler Coğrafi Bilgi Sistemleri (CBS), Hec-GeoRAS ve HECRAS hidrolik modelleri  ve hidrolojik modellerde kullanılmış ve analiz edilmiştir. Sonuç olarak, menba batardosu çökme modeli temelinde oluşturulan Çokal Barajı çökme modeli göstermiştirki, olası baraj çökmesi sonucunda oluşacak taşkın, Evreşe Ovası ve buradan geçimini sağlayan insanlar için büyük zararlar ortaya çıkartacaktır. Sadece tarım ürünleri üzerindeki genel tahmini kayıplar 12 milyon TL yi bulmaktadır. Böylelikle insanın doğaya yapmış olduğu müdahale sonucunda yine insanın kendisi büyük zararlar görecektir.     &nbsp

    MÜZİK ÖĞRETMENLİĞİ ÖĞRENCİLERİNİN ÇALGI PERFORMANSI ÖZYETERLİK İNANÇLARININ ÇEŞİTLİ DEĞİŞKENLER AÇISINDAN İNCELENMESİ (KLASİK GİTAR ÖRNEĞİ)

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    Bu araştırmada, müzik öğretmenliği bireysel çalgı eğitimi dersi kapsamında gerçekleştirilen klasik gitar eğitiminde, öğrencilerin klasik gitar performansı öz-yeterlik inançları cinsiyet, mezun oldukları lise türü, öğrenim gördükleri üniversite, devam etmekte oldukları sınıf, klasik gitara başlama yaşları ve günlük klasik gitar çalışma süresi değişkenleri açısından incelenmiştir. Araştırmanın çalışma grubunu, 2017- 2018 eğitim-öğretim yılında, Marmara Üniversitesi, Ondokuz Mayıs Üniversitesi, Karadeniz Teknik Üniversitesi, Balıkesir Üniversitesi, Abant İzzet Baysal Üniversitesi ve Harran Üniversitesi’nin Eğitim Fakültesi Güzel Sanatlar Eğitimi Bölümü Müzik Öğretmenliği Anabilim Dalı lisans programlarında öğrenim gören birinci, ikinci, üçüncü ve dördüncü sınıf klasik gitar öğrencileri oluşturmaktadır. Araştırmaya toplam 80 klasik gitar öğrencisi katılmıştır. Araştırma, öğrencilerin özyeterlik inanç durumlarının ortaya konması amacıyla tarama modelinin kullanıldığı betimsel bir araştırmadır. Araştırmada, klasik gitar öğrencilerinin demografik özelliklerinin belirlenmesi amacıyla araştırmacı tarafından geliştirilen Kişisel Bilgi Formu ile birlikte, klasik gitar performansı öz-yeterlik inanç düzeylerini saptamak için Girgin (2015) tarafından geliştirilen Çalgı Performansı Öz-yeterlik İnancı Ölçeği kullanılmıştır. Araştırma sonucunda elde edilen verilere göre, klasik gitar öğrencilerin klasik gitar performansı öz-yeterlik inançlarının cinsiyet, öğrenim gördükleri üniversite, devam etmekte oldukları sınıf, klasik gitara başlama yaşı ve günlük klasik gitar çalışma süresi değişkenlerine göre anlamlı düzeyde fark olduğu, mezun oldukları lise türü değişkenine göre istatistiksel olarak anlamlı düzeyde bir fark olmadığı sonucuna ulaşılmıştır

    Psikolojik Sözleşme İhlali ile İşten Ayrılma Niyeti İlişkisinde Demografik Değişkenlerin Düzenleyici Rolü (The Role of Perceived Demographic Variables as Moderator in the Link between Psychological Contract Breach and Turnover Intention)

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    Psikolojik sözleşme ihlali ile işten ayrılma niyeti, işletmeler için çok önemli konulardır. Psikolojik sözleşmesi ihlal edilen bireyler, işten ayrılmak isteyebilirler. Bu çalışma psikolojik sözleşme ihlali ile işten ayrılma niyeti ilişkisinde demografik değişkenlerin düzenleyici rolünü incelemeyi amaçlamaktadır. Çalışmanın amacını gerçekleştirmek için anket formu ile elde edilen veriler analiz edilmiştir. Bu bağlamda, anketler Türkiye'de vakıf üniversitelerden 412 öğretim görevlisi tarafından tamamlanmıştır. Elde edilen sonuçlara göre, psikolojik sözleşme ihlali ile işten ayrılma niyeti arasında pozitif bir ilişki olduğu görülmektedir. Ayrıca, demografik değişkenlerin psikolojik sözleşme ihlali ve işten ayrılma niyeti üzerinde çeşitli etkileri olduğu saptanmıştır. Psychological contract breach and turnover intention are crucial issues for organizations. İndividuals whose psychological contract is violated may intend to leave from their organizations. This study aims to examine the moderating role of demographic variables in the link between psychological contract breach and turnover intention. Data obtained by means of the questionnaire was analysed in order to realize the aim of the study. In this regard, the questionnaires were completed by 412 academicians from private universities, in Turkey. According to the results, it appeared to be a positive relationship between psychological contract breach and turnover intention.On the contrary, it is determined that demographic variables have various effect on psychological contract breach and turnover intentio

    Stereotactic body radioablation therapy as an immediate and early term antiarrhythmic palliative therapeutic choice in patients with refractory ventricular tachycardia

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    Background: Stereotactic body radioablation therapy (SBRT) has recently been introduced with the ability to provide ablative energy noninvasively to arrhythmogenic substrate while reducing damage to normal cardiac tissue nearby and minimizing patients’ procedural risk. There is still debate regarding whether SBRT has a predominant effect in the early or late period after the procedure. We sought to assess the time course of SBRT’s efficacy as well as the value of using a blanking period following a SBRT session. Methods: Eight patients (mean age 58 ± 14 years) underwent eight SBRT sessions for refractory ventricular tachycardia (VT). SBRT was given using a linear accelerator device with a total dose of 25 Gy to the targeted area. Results: During a median follow-up of 8 months, all patients demonstrated VT recurrences; however, implantable cardioverter-defibrillator (ICD) and anti-tachycardia pacing therapies were significantly reduced with SBRT (8.46 to 0.83/per month, p = 0.047; 18.50 to 3.29/per month, p = 0.036, respectively). While analyzing the temporal SBRT outcomes, the 2 weeks to 3 months period demonstrated the most favorable outcomes. After 6 months, one patient was ICD therapy-free and the remaining patients demonstrated VT episodes. Conclusions: Our findings showed that the SBRT was associated with a marked reduction in the burden of VT and ICD interventions especially during first 3 months. Although SBRT does not seem to succeed complete termination of VT in long-term period, our findings support the strategy that SBRT can be utilized for immediate antiarrhythmic palliation in critically ill patients with otherwise untreatable refractory VT and electrical storm

    Transhepatic left ventricular only pacing after left bundle branch area pacing attempt with high pacing threshold

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    A 50-year-old male with a permanent dual chamber pacemaker (DDD) 23 years ago was referred for a rapid increase in right ventricular (RV) pacing impedance. His left ventricular (LV) ejection fraction was 45%. Since the patient was pacemaker-dependent, the insertion of a new RV lead was planned. However, the venography and imaging studies revealed both left and right subclavian veins to be occluded/non-accessible. We failed also to cross the lesion by percutaneous approach. Then, we planned the extraction procedure as a first stage with the thought that it can provide a new venous route via extraction sheath; however, the patient did not accept the procedure as its high risk. Therefore, the surgical epicardial LV lead was implanted and connected to the left subpectoral pocket by using the previous functional right atrial (RA) lead for DDD pacing. Unfortunately, 1 month later, the patent presented with a left-sided pocket infection, and we had to remove all endocardial RA and RV leads using the lead extraction system. We could not again pass the calcified superior vena cava despite the successful lead extraction. Due to an active pocket infection, the surgically placed pacemaker was removed from the skin leaving the epicardial LV lead in place to remove or drain the infected fluid. A leadless pacemaker was an option, but due to financial constraints could not be done for this patient. The femoral venous access could not be taken due to the non-availability of 69 cm RV lead. The hepatic vein was the only available access to implant a DDD pacemaker

    Paradoxical para-hisian pacing response

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    Para-Hisian pacing (PHP) is among the most useful maneuvers in cardiac electrophysiology during sinus rhythm and identifies whether retrograde conduction is dependent on the atrioventricular (AV) node. In this maneuver, the retrograde activation time and pattern are compared during capture and loss of capture of the His bundle while pacing from a paraHisian position. A common misconception about PHP is that it is useful only for septal accessory pathways (APs). However, even with left or right lateral pathways, as long as pacing from the para-Hisian region conducts to the atrium with the activation sequence being analyzed, it can be used to determine whether that activation is AV node–dependent or AP-dependent

    Double-application of platelet-rich plasma on bone healing in rabbits

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    Objective: Platelet-rich plasma (PRP) is considered to enhance bone formation especially at early stages of wound healing, depending on the limited and short life-span of platelets and growth factors. The aim of this study was to evaluate efficacy of double-application of PRP (DA-PRP) on bone healing in a rabbit calvarial defect model. Study design: Twenty-eight rabbits, each had two surgically prepared calvarial bone defects (10mm diameter), were included in this study and randomly divided into six groups. Defects (n=56) were treated with single-application of PRP (SA-PRP)(n=10), SA-PRP and beta-tricalciumphosphate (SA-PRP+TCP)(n=10), DA-PRP (n=8), DA-PRP and beta-tricalciumphosphate (DA-PRP+TCP)(n=8), beta-tricalciumphosphate (TCP)(n=10) or left empty (Control)(n=10). Animals were sacrificed at 30 days postoperatively. Results: The new bone (NB%) and defect fill (DF%) percentages were calculated from histological slides by image-analyzer software and statistically analysed. All test groups showed higher NB% than control, but differences among all groups were insignificant. The TCP treated groups had significantly higher DF% than groups treated without TCP, however the DF% differences between control, SA-PRP and DA-PRP or TCP, SA-PRP+TCP or DA-PRP+TCP were insignificant. Conclusion: Although new bone formation was histomorphologically remarkable at double-application PRP groups, statistical analyses of the histomorphometric data revealed no significant difference. © Medicina Oral S. L
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