A simulation program for efficient analysis of linear circuits

Ankara : Department of Electrical and Electronics Engineering and Institute of Engineering and Sciences, Bilkent University, 1996.Thesis (Master's) -- Bilkent University, 1996.Includes bibliographical references leaves 45-46.circuit simulation program using generalized asymptotic waveform evaluation technique is introduced. The program analyzes circuits with lumped a.nd distributed components. It computes the moments ci.t a few Irecjuency points and extracts the coefficients of an approximating rational by employing one of t,he two different methods. One of the examined methods is proposed to compare the accuracy of results and the execution times with conventional simulators and sevei’cil examples are demonstrated, indicating that our sirnulcv tor provides a. speed improvement without a significant loss of accuracy.Sungur, MustafaM.S

Bilateral avascular necrosis of the femoral head due to the use of heroin: A case report

AbstractIntroductionFemoral head avascular necrosis is caused by disruption of the blood supply of the femoral head, which finally results in hip dysfunction. Non traumatic osteonecrosis may related with corticosteroid use, alcohol abuse, SLE, hemoglobinopathies or exposure to cytotoxic agents. But avascular necrosis of the femoral head (ANFH) due to heroin use is a rare condition. We report a patient with bilateral ANFH due to heroin use treated by simultaneous bilateral hip arthroplasty.Presentation of case37 year-old male patient presented with bilateral hip pain that had been occurring for four years. The patient had no history of smoking, excessive drinking, using corticosteroid and the other drugs or trauma but used heroin for 10 years. In clinic and radiologic examination indicated advanced degenerative changes on both hip due to femoral head avascular necrosis. The patient was treated with simultaneous bilateral total hip arthroplasty. After 6 months postoperatively the active hip range of motion was painless.DiscussionAvascular femoral head necrosis caused by the using of heroin is rare. Ultimately, osteonecrosis of the femoral head occurs through one final common pathway, which is decreased blood flow to the femoral head that leads bone ischemia and death. But it is still unknown that heroin’s systemic effects. Intravenous drug use more as a serious problem for today. There is a need for comprehensive studies to demonstrate effects of heroin on bone and vascularity metabolism.ConclusionHeroin use will be important problem for population. That’s why is crucial to understand the effect of heroin

Postoperative mechanical alignment analysis of total knee replacement patients operated with 3d printed patient specific instruments: A prospective cohort study

Objective: Total knee replacement (TKR) is a surgical treatment for final stage gonarthrosis. The lifespan of the prosthetic implants used in TKR surgery is a major interest for the orthopaedic research community.Previously, proper implant alignment of the implants has been advocated for longevity of the TKR surgery. Recently, patient-specific (PSI) instruments have been proposed to improve the mechanical alignment of the TKR by permitting better implant positioning over conventional TKR surgery. The aim of this study is to compare the mechanical alignment results of patients operated with PSIs and conventional instruments. Methods: Two groups of 20 patients chosen in a quasi-random manner have been compared in this study. In the first group femoral distal and tibial osteotomies were made by a PSI which was produced by the patients’ computed tomography scans. All osteotomies in the control group were made with the TKR set's routine instruments by conventional means. Patients’ preoperative and postoperative mechanical femorotibal angles (mFTA), femoral coronal angles (FCA), tibial coronal angles (TCA) were measured and the number of outliers which showed more than 3° of malalignment were counted in both groups for comparison. Results: The average postoperative mFTA was found to be 2.09° for the PSI group and in was found to be 284° for the control which was not statistically significant. The comparison of postoperative FCA and TCA also did not show significant difference between the groups. The number of outliers showing more than 3° of malalignment per group were found to be 1 out of 20 (5%) for the PSI group and 7 out of 20 (35%) for the control which was statistically significant. Conclusion: In this study patient-specific instrumentation provided significantly better mechanical alignment compared to conventional TKR for the frequency of outlier cases with malalignment beyond 3°. PSI proved no significant difference when the groups were compared for mFTA, FCA and TCA. Our findings support that PSI may improve TKR alignment by improving the ratio of the outlier patients with marked malalignment. Level of Evidence: Level III, Therapeutic Study

Evaluation of Healthy Lifestyle Behaviours: A Research on Hospitalized Patients

Bu çalışmanın amacı, morbidite ve mortalite oranlarının daha yüksek olduğu klinik birimlerden sağlık hizmeti alan bireylerin Sağlıklı Yaşam Biçimi Davranışı (SYBD) alışkanlıklarını incelemek ve buna etki eden faktörleri ortaya koymaktır. Bu amaçla bir eğitim araştırma hastanesinin göğüs hastalıkları-göğüs cerrahisi, onkoloji-hematoloji, kalp-damar cerrahisi ve kardiyoloji klinikleri olmak üzere toplamda 4 farklı klinikte sağlık hizmeti alan 137 kişi üzerinde SYBD ölçeği uygulanmıştır. Anket verileri SPSS 21 paket programı ile analiz edilmiş, Tek Yönlü Varyans Analizi (ANOVA) ile Kruskal Wallis Testi uygulanmıştır. Demografik özellikler ve hizmet alınan klinik açısından SYBD’nin gruplar arasında farklılık gösterdiği bulunmuştur. Bu bağlamda özellikle potansiyel sağlık riski olan 65 yaş üstü kişiler ile onkoloji ve kalp damar hastalık riski gruplarının SYBD açısından özendirilmesinin gerekli olduğu düşünülmektedir.The aim of this study is to investigate the healthy lifestyle behaviours (HLB) of patients who received health care from clinical units with higher morbidity and mortality rates and to put forth the factors which affect the HLB. To this end, SYBD scale was applied to 137 people who received health services in 4 clinics, including thoracic diseases-thoracic surgery, oncology-haematology, cardiovascular surgery and cardiology clinics in a training and research hospital. The survey data analyzed with SPSS 21 package program, One-Way ANOVA and Kruskal Wallis tests were applied. It was found that SYBD varied between the groups in terms of demographic characteristics and clinical service. In this context, it is considered that especially those with 65 years of age who have potential health risks and the risk groups of oncology and cardiovascular disease should be encouraged with regard to HLB

Arıburnu yalıtaşının (Gelibolu Yarımadası, Türkiye) kökeni ve yaşı üzerine

The beachrock formation on the Ariburnu coast situated in the Gelibolu Peninsula has been studied by field observation, thin-section interpretation, physicochemical analyses including ICP-AES and SEM/EDS, and OSL dating. These analyses reveal the presence of different amounts of major (Si, Ca, Mg, K, Fe, Al and Na) and trace elements within the beachrock cement with Si (36.2%) and Ca (32.68%) dominating the overall composition. Beachrocks composed of highly-fractured and friable beds reach a total thickness of 80 cm extending from + 60 cm at the uppermost level down to-1 m at their most seaward extent and grade from conglomerate to lithic arkose in vertical section. The total amount of CaCO(3) ranges between 59.08% and 36% and the cement consists of high-Mg calcite based on EDS analysis. From SEM examination, four main morphologies were identified in cement material: (1) micritic coatings, (2) cryptocrystalline pore-filling cement, (3) meniscus cement and (4) microbial cement and suggest the presence of marine phreatic conditions with the exception of meniscus bridges, which imply that cementation may have been dominated by carbonate-rich meteoric waters at any successive stage of cementation. Five buried beachrock samples under unconsolidated beach sand were sampled for Optically Stimulated Luminescence (OSL) dating and show that the minimum and maximum ages of beachrock are 1.42 +/- 0.20 ka and 2.28 +/- 0.28 ka BP, respectively.Bu çalışmada Gelibolu Yarımadası’nda, Arıburnu kıyılarındaki yalıtaşı oluşumu arazi verileri, ince kesit yorumlamaları, ICP-AES, EDS ve SEM analizleri ve OSL yaşlandırması ile ele alındı. Analizler yalıtaşı çimentosu içinde Si, Ca, Mg, K, Fe, Al ve Na gibi ana ve iz elementlerin nispeten farklı oranlarda bulunduğunu göstermektedir. Bileşimde Si (36.2%) ve Ca (32.68%) egemendir. Yalıtaşları bol kırıklı ve kırılgan, toplam 80 cm tabaka kalınlığına sahip olup, en yüksek seviyede +60 cm’den deniz içinde –1 m’ye kadar takip edilirler. Düşey kesitte çakıltaşlarından litik arkoza geçişlidirler. Toplam CaCO3 miktarı 59.08% ve 36% arasında değişir. EDS analizlerine gore çimento maddesi yüksek magnezyum kalsittir. SEM analizlerine göre çimento maddesinde 4 ana morfoloji tanımlanmıştır; (1) mikritik tabakalar, (2) kriptokristalin boşluk dolgusu çimento, (3) menisküs çimento ve (4) mikrobial çimento. Bu çimentolar, çimentolanmanın izleyen bir devresinde karbonat bakımından zengin meteorik sularca meydana getirildiğini gösteren menisküs çimento hariç, denizel freatik koşullarda geliştiğini göstermektedir. Kıyı çizgisi gerisindeki plaj kumları altından çıkarılan 5 örneğin ‘optik uyarımlı ışınım tekniği (OSL)’ yöntemi ile yaşlandırması yapıldı. Analizler yalıtaşının oluşum yaşı için minimum 1.42±0.20 bin yıl ve maksimum 2.28±0.28 bin yıl yaşlarını vermektedir.Publisher's Versio

Bir Asrı Geçen Birikimle Misak-ı Milli'ye Yeniden Bakmak

Kitap, "Bir Asrı Geçen Birikimle Misak-ı Milli'ye Yeniden Bakmak-Misak-ı Milli Anma Programı" konulu panelde sunulan tebliğleri içermektedir

Risk factors affecting success of urethroplasty in male patients – Single center results

Amaç: Bu çalışmada kliniğimizde üretroplasti yapılan erkek hastalar incelenerek olguların sonuçları ve üret- roplasti başarısı üzerine etkili risk faktörleri araştırıldı. Materyal ve metod: Bu retrospektif çalışmada, üretra darlığı olan erkek hastalarda tek cerrah tarafından uygulanan farklı üretroplasti tekniklerini takiben tedavi başarısını etkileyen faktörleri belirlemek için tek değişkenli ve çok değişkenli analizler kullanılmıştır. Bulgular: 102 erkek hastada gerçekleştirilen üretroplasti vakalarında ortalama yaş 49 yıl, ortalama darlık uzunluğu 3,9 cm ve başarı oranı % 84 olarak belirlendi. Çok değişkenli analiz sonuçlarına göre diyabetes mellitus (DM) varlığı, önceden geçirilmiş üretratomi interna (İÜ) sayısı ve darlık uzunluğu üretroplasti başarısını öngören faktörler olarak tanımlandı. (OR 1.257; 95% CI 0.073-0.909; p=0.035, OR 5.343; 95% CI 2.233-12.782; p=0.005 ve OR 8.683;% 95 CI 2.950-25.561; p=0.025) Sonuç: Üretroplasti, üretra darlığı tedavisinde altın standart bir cerrahi prosedür olmakla beraber DM varlığı, birden çok İÜ öyküsü ve uzun darlıklar tedavi başarısızlığı ile ilişkilidir. Üretroplasti teknikleri birden çok faktör ile değerlendirilmeli ve deneyimli merkezlerde gerçekleştirilmelidir.Background: In this study, male patients who underwent urethroplasty in our clinic were examined, and the outcome of the cases and the risk factors affecting the success of urethroplasty were investigated. Materials and Methods: In this retrospective study, univariate and multivariate analyzes were used to de- termine the factors affecting treatment success following different urethroplasty techniques performed by a single surgeon in male patients with urethral stricture. Results: In the urethroplasty cases performed in 102 male patients, the mean age was 49 years, the mean stenosis length was 3.9 cm, and the success rate was 84%. According to the results of the multivariate analysis, the presence of diabetes mellitus (DM), the number of previous urethratomy interna (IU) and the length of the stenosis were defined as the factors predicting the success of urethroplasty. (OR 1.257; 95% CI 0.073-0.909; p=0.035, OR 5.343; 95% CI 2.233-12.782; p=0.005 and OR 8.683; 95% CI 2.950-25.561; p=0.025) Conclusions: Although urethroplasty is the gold standard surgical procedure in the treatment of urethral strictures, the presence of DM, multiple IU history, and long strictures are associated with treatment fail- ure. Urethroplasty techniques should be evaluated with multiple factors and performed in experienced centers

Scientific contribution of Turkey in prostate literature. Where are we? Where are we going?

Prostate cancer is a common malignancy in the world. The established risk factors are increasing age, race and family history. The incidence of prostate cancer is low in Asia, but the overall age-adjusted incidence rate of PCa was reported as 35/100,000 from years of 2008 to 2009 in Turkey. The aim of the study is to investigate the articles from Turkey about prostate cancer for ten years period. The data from the Institute for Scientific Information Web of Science was reviewed and ‘prostate adenocarcinoma’ in the title was searched in each year from 2006 to 2015. The article, review and letter were selected. Number of articles from Turkey and world was recorded and localization of the top ten countries were noted. There were 28,714 articles between 2006 and 2015 years. The articles increased from 11,998 to 16,716 in last 5 years. In Turkey; the articles was 120 in first 5 year and increased to 205 in the last 5 years. The percentage of increases was 39.3 and 70.8% in the world and Turkey. Ranking to the countries according to the article numbers; Turkey was between 17–23 and 16–27 in first and second five years. The number of the countries whom published prostate cancer articles reached to 89 in ten years. The number of the articles is increased during the years. When we think the nüfüs of the country and number of the academicians, the number of the articles would be more than today. The urologists must work more than last to improve the Turkish scientific localization. The clinical chefs of the university and training hospitals can organize well designed clinical studies and Turkish Association of Urology and Oncology promote the clinical studies, we can publish more and more studies