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4,476 results on '"Erkan, E"'

2. In vitro and in vivo evaluation of the osseointegration capacity of a polycarbonate‐urethane zirconium‐oxide composite material for application in a focal knee resurfacing implant.

Author

van Hugten, Pieter P. W., Jeuken, Ralph M., Asik, Erkan E., Oevering, Henk, Welting, Tim J. M., van Donkelaar, Corrinus C., Thies, Jens C., Emans, Peter J., and Roth, Alex K.

Abstract

Currently available focal knee resurfacing implants (FKRIs) are fully or partially composed of metals, which show a large disparity in elastic modulus relative to bone and cartilage tissue. Although titanium is known for its excellent osseointegration, the application in FKRIs can lead to potential stress‐shielding and metal implants can cause degeneration of the opposing articulating cartilage due to the high resulting contact stresses. Furthermore, metal implants do not allow for follow‐up using magnetic resonance imaging (MRI).To overcome the drawbacks of using metal based FKRIs, a biomimetic and MRI compatible bi‐layered non‐resorbable thermoplastic polycarbonate‐urethane (PCU)‐based FKRI was developed. The objective of this preclinical study was to evaluate the mechanical properties, biocompatibility and osteoconduction of a novel Bionate® 75D ‐ zirconium oxide (B75D‐ZrO2) composite material in vitro and the osseointegration of a B75D‐ZrO2 composite stem PCU implant in a caprine animal model. The tensile strength and elastic modulus of the B75D‐ZrO2 composite were characterized through in vitro mechanical tests under ambient and physiological conditions. In vitro biocompatibility and osteoconductivity were evaluated by exposing human mesenchymal stem cells to the B75D‐ZrO2 composite and culturing the cells under osteogenic conditions. Cell activity and mineralization were assessed and compared to Bionate® 75D (B75D) and titanium disks. The in vivo osseointegration of implants containing a B75D‐ZrO2 stem was compared to implants with a B75D stem and titanium stem in a caprine large animal model. After a follow‐up of 6 months, bone histomorphometry was performed to assess the bone‐to‐implant contact area (BIC). Mechanical testing showed that the B75D‐ZrO2 composite material possesses an elastic modulus in the range of the elastic modulus reported for trabecular bone. The B75D‐ZrO2 composite material facilitated cell mediated mineralization to a comparable extent as titanium. A significantly higher bone‐to‐implant contact (BIC) score was observed in the B75D‐ZrO2 implants compared to the B75D implants. The BIC of B75D‐ZrO2 implants was not significantly different compared to titanium implants. A biocompatible B75D‐ZrO2 composite approximating the elastic modulus of trabecular bone was developed by compounding B75D with zirconium oxide. In vivo evaluation showed an significant increase of osseointegration for B75D‐ZrO2 composite stem implants compared to B75D polymer stem PCU implants. The osseointegration of B75D‐ZrO2 composite stem PCU implants was not significantly different in comparison to analogous titanium stem metal implants. [ABSTRACT FROM AUTHOR]

Published
2024
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15. Treatment of multiresistant gram negative ventriculitis with intraventricular ciprofloxacin

Author

BİLGEN, H., ÖZEK, E., ERKAN, E., ÖRS, R., ÖZEK, Mm., İNCE, Z., and SÖYLETİR, G.

Subjects
Treatment of multiresistant gram negative ventriculitis with intraventricular ciprofloxacin, Medicine, Tıp
Abstract

Central nervous system infection remains an important cause of mortality and morbidity in patients with open spinal dysraphism.Two cases of myelochisis with multiresistant Klebsiella Ventriculitis were treated with intraventricular ciprofloxacin for persistently positive CSF cultures after commencement of iv quinolone treatment. The patients were cured both clinically and microbiologically. No significant adverse effects were observed in any of these patients.

Published
2016

25. Akt links insulin signaling to albumin endocytosis in proximal tubule epithelial cells

Author

Coffey, S, Costacou, T, Orchard, T, Erkan, E, Coffey, S, Costacou, T, Orchard, T, and Erkan, E

Abstract

Diabetes mellitus (DM) has become an epidemic, causing a significant decline in quality of life of individuals due to its multisystem involvement. Kidney is an important target organ in DM accounting for the majority of patients requiring renal replacement therapy at dialysis units. Microalbuminuria (MA) has been a valuable tool to predict end-organ damage in DM but its low sensitivity has driven research efforts to seek other alternatives. Albumin is taken up by albumin receptors, megalin and cubilin in the proximal tubule epithelial cells. We demonstrated that insulin at physiological concentrations induce albumin endocytosis through activation of protein kinase B (Akt) in proximal tubule epithelial cells. Inhibition of Akt by a phosphorylation deficient construct abrogated insulin induced albumin endocytosis suggesting a role for Akt in insulin-induced albumin endocytosis. Furthermore we demonstrated a novel interaction between Akt substrate 160kDa (AS160) and cytoplasmic tail of megalin. Mice with type 1 DM (T1D) displayed decreased Akt, megalin, cubilin and AS160 expression in their kidneys in association with urinary cubilin shedding preceding significant MA. Patients with T1D who have developed MA in the EDC (The Pittsburgh Epidemiology of Diabetes Complications) study demonstrated urinary cubilin shedding prior to development of MA. We hypothesize that perturbed insulin-Akt cascade in DM leads to alterations in trafficking of megalin and cubilin, which results in urinary cubilin shedding as a prelude to MA in early diabetic nephropathy. We propose that utilization of urinary cubilin shedding, as a urinary biomarker, will allow us to detect and intervene in diabetic nephropathy (DN) at an earlier stage. Copyright

Published
2015

35. Composites of bovine hydroxyapatite (BHA) and ZnO

Author

Gunduz, O., Erkan, E. M., Daglilar, S., Salman, S., Agathopoulos, S., and Oktar, F. N.

Subjects
zinc release, mechanical-properties, glass-ceramics, apatite, enamel, coatings, bone, sintering temperature
Abstract

Composites of calcinated bovine bone-derived hydroxyapatite (BHA), doped with 2.5, 5, and 10 wt.% ZnO were produced by sintering. Scanning electron microscopy (SEM) and X-ray diffraction analysis together with measurements of density, compressive strength, and Vickers microhardness were carried out in the sintered samples. The experimental results showed that the best mechanical properties were achieved in the samples with 5% addition of ZnO. The highest value of compression strength was achieved after sintering at 1200 degrees C (72 MPa) and of microhardness at 1300 degrees C (548 HV). Prolong heat treatment at 1300 degrees C results in vulnerable BHA-ZnO composites to over-firing effect. Journal of Materials Science

Published
2008

36. Relation between blood vitamin B12 levels with premature ejaculation: case-control study.

Author

Kadihasanoglu, M., Kilciler, M., Kilciler, G., Yucetas, U., Erkan, E., Karabay, E., Toktas, M. G., and Kendirci, M.

Subjects
VITAMIN B12, PREMATURE ejaculation, VAGINAL contraceptives, BECK Depression Inventory, MENTAL illness
Abstract

The aim of this study was to investigate whether vitamin B12 levels are associated with premature ejaculation ( PE). A total of 109 subjects (56 PE and 53 controls) were included in this study. PE was defined as self-reported intravaginal ejaculatory latency time ( IELT) based on the Diagnostic and Statistical Manual of Mental Disorders IV criteria and those who had had an IELT of <2 min was considered as PE. All participants were evaluated using premature ejaculation diagnostic tool ( PEDT), International Index of Erectile Function ( IIEF) and Beck Depression Inventory ( BDI). The vitamin 12 levels were measured in all subjects. The mean age between the PE and controls was comparable ( p = .084). Mean IIEF and BDI scores between the two groups did not statistically differ. The mean IELT values in the PE group were significantly lower than in the control group ( p < .0001). PE patients reported significantly lower vitamin B12 levels compared with the controls (213.14 vs. 265.89 ng ml−1; p < .001). The ROC analysis showed a significant correlation between the diagnosis of PE and lower vitamin B12 levels. This study has demonstrated that lower vitamin B12 levels are associated with the presence of PE. This work also shows a strong correlation between vitamin B12 levels and the PEDT scores as well as the IELT values. [ABSTRACT FROM AUTHOR]

Published
2017
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37. Yükseköğretime giriş puanları ile birlikte mesleki ilgi alanları puanlarının akademik başarıyı yordama gücünün araştırılması

Author

Erkan, E. Gökhan, Kutlu, Ömer, and Diğer

Subjects
Eğitim ve Öğretim, Education and Training
Abstract

ÖZET YÜKSEKÖĞRETİME GİRİŞ PUANLARI İLE BİRLİKTE MESLEKİ İLGİ ALANLARI PUANLARININ AKADEMİK BAŞARİYİ YORDAMA GÜCÜNÜN ARAŞTIRILMASI Erkan, Emre Gökhan Yüksek Lisans, Ölçme ve Değerlendirme (Psikometri) Anabilim Dalı Tez Danışmanı: Yard. Doç. Dr. Ömer Kutlu Haziran 2004, 52 Sayfa Bu araştırmada, yükseköğretime giriş puanları ile birlikte mesleki ilgi alanları puanlarının akademik başarıyı yordama gücünün araştırılması amaçlanmıştır. İlişkisel tarama modelinde olan araştırmanın çalışma grubunu 2002 yılı ÖSS - Eşit Ağırlıklı (ÖSS-EA) puan türü ile Ankara Üniversitesi Eğitim Bilimleri Fakültesi'nin Okul Öncesi ve Sınıf öğretmenliği bölümlerine girmiş olan 160 ikinci sınıf öğrencisi oluşturmuştur. Çalışma grubunda yer alan öğrencilerin mesleki ilgi alanı puanları Kuder İlgi Alanları Tercih Envanteri uygulanarak elde edilmiştir. Elde edilen verilerin çözümlenmesin de SPSS programından yararlanılmıştır. Öğrencilerin ÖSS giriş puanlan ile birlikte mesleki ilgi alanları puanlarının üniversitedeki akademik başarılarını yordama gücü Çoklu Regresyon Analizi ile incelenmiştir. Bu araştırmadan elde edilen bulgular, öğrencilerin ÖSS giriş puanlarının üniversitedeki akademik başarını anlamlı bir şekilde yordamadığını, mesleki ilgi alanları puanlarının da yordayıcı birer değişken olarak ele alındığında ise yordayıcı değişkenlerin akademik başarı üzerindeki göreli önem sırası; Edebiyat İlgisi, Büro İlgisi, El İşi İlgisi, Açık Hava İlgisi, Müzik İlgisi, İlim İlgisi, Sosyal İlgisi, Hesap İlgisi, Sanat İlgisi, Giriş Puanı, İkna İlgisi'dir. Regresyon katsayılarının anlamlılığına ilişkin t - testi sonuçları incelendiğinde ise, yalnızca Edebiyat İlgisi değişkeninin Akademik başarı üzerinde anlamlı bir yordayıcı olduğu, diğer değişkenlerin anlamlı bir etkiye sahip olmadığı gözlenmiştir. in ABSTRACT Erkan, Emre Gökhan Graduate Program, Measurement and Evaluation (Psycometry) Department Thesis Advisor: Assistant Assosiated Professor Dr. Ömer Kutlu June 2004, Total 52 pages A RESEARCH ON THE PREDICTION POWER OF UNIVERSITY ENTRANCE TEST SCORES TOGETHER WITH OCCUPATIONAL INTEREST SURVEY SCORE FOR ACADEMIC SUCCESS The purpose of this research is to study the prediction power of university entrance test scores together with occupational interest survey scores for academic success. The study group of the research in Correlation Survey Model include 160 students in the 2nd year of the preschool and primary school teacher departmant of Educational Sciences Faculty in Ankara University, who had been accepted to university with the score type- ÖSS-EA (Equal Weighted Score) in 2002. The occupatioal interest of the students in the study group is provided by Kuder Occupational Interest Survey. The SPSS program is used for analyzing the obtained data. The prediction power of university entrance test scores and occupational interest scores of the students are studied with Multiple Regression Analysis. The obtained findings of the research are as follows: University Entrance Test (ÖSS) scores of the students has no significant meaning on their academic success in the university; and when Occupational Interest scores are assumed as predictive variable, the relative order of priority of predictive IVvariable is listed as Literature Interest, Office Interest, Handicraft Interest, Open Air Interest, Music Interest, Science Interest, Social Interest, Account Interest, Entrance Test Scores and Persuadion Interest. However, when the result of t-test regarding the significance of regression analysis are analysed, it is seen that only the literature interest variable is a significant predictive on academic success, while the other variables has no significant effect. V 62

Published
2004

39. miR-200a-mediated suppression of non-muscle heavy chain IIb inhibits meningioma cell migration and tumor growth in vivo

Author

Senol, O, primary, Schaaij-Visser, T B M, additional, Erkan, E P, additional, Dorfer, C, additional, Lewandrowski, G, additional, Pham, T V, additional, Piersma, S R, additional, Peerdeman, S M, additional, Ströbel, T, additional, Tannous, B, additional, Saydam, N, additional, Slavc, I, additional, Knosp, E, additional, Jimenez, C R, additional, and Saydam, O, additional

Published
2014
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41. Real estate investment trusts (REITS): A new urban development instrument for public lands in Turkey

Author

Erkan, E. Ayşe, Pınarcıoğlu, M. Melih, and Diğer

Subjects
Planning, Şehircilik ve Bölge Planlama, Project management, Urban and Regional Planning, Public land
Abstract

öz GAYRİMENKUL YATIRIM ORTAKLIKLARI (GYO) TÜRKİYE'DEKİ KAMU ARAZİLERİ İÇİN YENİ BİR KENTSEL GELİŞTİRME ARACI ERKAN, E. AYŞE M.S., Şehir Planlama Bölümü Tez Yöneticisi: Doç. Dr. M. Melih PINARCIOĞLU Aralık 2002, 190 sayfa Bu tez, kamu arazilerinin değerlendirilmesinde gayrimenkul yatırım ortaklıklarının alternatif bir kentsel geliştirme aracı olarak kullanılıp kullanılamayacağı konusunu tartışmaktadır. Gayrimenkul Yatırım Ortaklıkları (GYO'lar), kamu sektörünün büyük ölçekli kentsel projeleri gerçekleştirme sürecinde karşılaştığı mali ve proje yönetimi gibi temel zorlukların aşılması açısından önemlidir. Bu tez Türkiye'de uzun vadeli, etkin ve uygulanabilir arsa/arazi politikalarının geliştirilememesi, alınan kararların planlama süreciyle uyumunu sağlayacak herhangi bir kurum kuruluşun olmaması ve özellikle uzun vadede kentsel geliştirme projelerini destekleyecek kurumsal bir finansman sistemi geliştirilememesinin sebeplerini ortaya koymakta ve bu konulardaki eksiklikleri dünya örnekleriyle karşılaştırılarak değerlendirmiştir. Gayrimenkul projelerinin finansmanında, gayrimenkul(ler) veya gayrimenkule dayalı sermaye piyasası araçlarından oluşan portföylerinin, menkul kıymetleştirme yoluyla finansal bir araç olarak kullanılmasını sağlayan Gayrimenkul Yatırım Ortaklıkları (GYO'lar) önplana çıkmıştır. Gayrimenkul Yatırım Ortaklıkları tüm dünyada,finansman kaynağı sağlama kolaylığı ve iyi proje yönetimi araçlarını kullanmak suretiyle başarılı olurken eldeki arazilerin değerlendirilmesi için devletin sahip olduğu bir gayrimenkul yatırım ortaklığının başarılı olması mümkün görünmemektedir. Bu bağlamda, kamuya ait gayrimenkul yatırım ortaklıklarının neden başarılı olamıyacağı konusuna açıklık getirilmiştir. Anahtar Kelimeler: kamu arazileri, planlama, gayrimenkul finansmanı, GYO, kamu GYO'su, project management vı ABSTRACT REAL ESTATE INVESTMENT TRUSTS (REITS): A NEW URBAN DEVELOPMENT INSTRUMENT FOR PUBLIC LANDS IN TURKEY ERKAN, E. AYŞE M.S., Department of City Planning Supervisor: Assoc. Prof. Dr. M. Melih PINARCIO?LU December 2002, 190 pages In this thesis, it is discussed whether real estate investment trusts can be an alternative way of urban development instrument for the evaluation of public lands or not. Real Estate Investment Trusts (REITs) can enable public sector to conquer some of the fundamental problems like financial and project management, which it has faced in the realization of large-scale development projects. This thesis lays down first reasoning of the deficiencies in the long term, effective, and applicable public land policies and an agency for the harmonization of public land use decisions and planning process, and particularly institutional structure for financing mechanisms for large scale development projects in the long run in Turkey. Above mentioned issues are also assessed together with the world practices. Real Estate Investment Trusts (REITs) have become an important financing mechanism for real estate development projects, by enabling to use their portfolios, composed of real estate(s) and capital market tools based on real estate(s), as a financing tool through insecuritization. Although Real Estate Investment Trusts are flourishing throughout the world by using easy financing and good project management instruments, success of REIT that is totally owned by state, and established for the evaluation of lands, is envisioned impossible. In that respect, it has been clarified that why REITs owned by the state will fail to succeed. Keywords: public lands, planning, real estate financing, REITs, public REIT, project management IV 190

Published
2002

43. Alemtuzumab pre-conditioning with tacrolimus monotherapy in pediatric renal transplantation

Author

Shapiro, R, Ellis, D, Tan, HP, Moritz, ML, Basu, A, Vats, AN, Kayler, LK, Erkan, E, McFeaters, CG, James, G, Grosso, MJ, Zeevi, A, Gray, EA, Marcos, A, Starzl, TE, Shapiro, R, Ellis, D, Tan, HP, Moritz, ML, Basu, A, Vats, AN, Kayler, LK, Erkan, E, McFeaters, CG, James, G, Grosso, MJ, Zeevi, A, Gray, EA, Marcos, A, and Starzl, TE

Abstract

We employed antibody pre-conditioning with alemtuzumab and posttransplant immunosuppression with low-dose tacrolimus monotherapy in 26 consecutive pediatric kidney transplant recipients between January 2004 and December 2005. Mean recipient age was 10.7 ± 5.8 years, 7.7% were undergoing retransplantation, and 3.8% were sensitized, with a PRA >20%. Mean donor age was 32.8 ± 9.2 years. Living donors were utilized in 65% of the transplants. Mean cold ischemia time was 27.6 ± 6.4 h. The mean number of HLA mismatches was 3.3 ± 1.3. Mean follow-up was 25 ± 8 months. One and 2 year patient survival was 100% and 96%. One and 2 year graft survival was 96% and 88%. Mean serum creatinine was 1.1 ± 0.6 mg/dL, and calculated creatinine clearance was 82.3 ± 29.4 mL/min/1.73 m 2. The incidence of pre-weaning acute rejection was 11.5%; the incidence of delayed graft function was 7.7%. Eighteen (69%) of the children were tapered to spaced tacrolimus monotherapy, 10.5 ± 2.2 months after transplantation. The incidence of CMV, PTLD and BK virus was 0%; the incidence of posttransplant diabetes was 7.7%. Although more follow-up is clearly needed, antibody pre-conditioning with alemtuzumab and tacrolimus monotherapy may be a safe and effective regimen in pediatric renal transplantation. © 2007 The Authors.

Published
2007

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