Experimental and Theoretical Study on Behaviour of Geometrically Asymmetric Composite Marine Sandwich Beams under Bending Load

This study presents a detailed investigation on the three-point and four-point bending behaviour of asymmetric sandwich beams composed of polyvinyl chloride (PVC) foam core and E-glass fibre reinforced polymer face sheets. The effects of mid-plane asymmetry on the bending load-displacement behaviour and failure mechanism of the sandwich beams were examined. Simple analytical expressions accounting for flexural and shear rigidities of the sandwich beams were proposed to predict the failure load, mid-span deflection and equivalent bending stiffness of the specimens and validated against experimental results. By shifting the loading direction, the flexural behaviour of asymmetric beams may be controlled. On the loading side, the use of face sheet with thick or high in-plane mechanical characteristics resulted in a delay in compressive failure of the top face sheet. The effective bending stiffness was overestimated since the applied formula did not account for shear deformations. First-order shear deformation theory was used to estimate the mid-span displacement values of sandwich beams in elastic regime and showed good agreement with the experimental results

Bilateral Sigmoid Sinus Thrombosis and Otitis Media

Sigmoid sinus thrombosis is a rare complication of otitis media and is known to be unilateral. In this report, we present a case of bilateral sigmoid sinus thrombosis secondary to bilateral otitis. To the best of our knowledge, there are no bilateral-simultaneous cases reported in literature to date. Here, the diagnosis of and treatment for the disease as well as predisposing factors are discussed

Severe iron overload and hyporegenerative anemia in a case with rhesus hemolytic disease: therapeutic approach to rare complications

A 33 weeks’ gestation, a baby with rhesus hemolytic disease (RHD), who had received intrauterine transfusions twice, developed cholestatic hepatic disease and late hyporegenerative anemia. Her serum ferritin and bilirubin levels increased to 8842 ng/ml and 17.9 mg/dl, respectively. Liver biopsy showed cholestasis and severe iron overload. Treatment with recombinant erythropoietin (rHuEPO) decreased the transfusion need, and intravenous deferoxamine resulted in a marked decreased in serum ferritin levels and normalization of liver function. In patients who have undergone intrauterine transfusions due to RHD, hyperferritinemia and late hyporegenerative anemia should be kept in mind. Chelation therapy in cases with symptomatic hyperferritinemia and rHuEPO treatment in cases with severe hyporegenerative anemia should be considered

Bir Geminin Hikâyesi: Germanic/Gülcemal Vapuru (1874-1950)

The New Continent, which Christopher Columbus discovered unconsciously in 1492 and which would unlucky be called America, would change the way the world was perceived. Within a few centuries following the discovery of America, the whole world would be shared by colonial empires. There would be uninterrupted trade networks between Western European countries and the New World developing in the Atlantic trade. The Sailing ships, which are the only means of transport on the trade routes, left their place to steam ships, which provided faster and safer travel after the Industrial Revolution. The Ottoman Empire quickly adapted to the steam ships, they met during the 2nd Mahmut period. From the middle of 19th century on, steam ships became only ruler of the seas. The steamer Germanic/Gul Djemal, purchased by the Ottoman Empire just Balkan Wars, it is the first transatlantic ship possessed by the Turks. Gul Djemal, who will serve for many years, would witness many important events of the periods.1492 yılında Kristof Kolomb’un farkında olmadan keşfettiği ve talihsiz bir biçimde Amerika olarak adlandırılacak olan yeni kıta Dünya’nın algılanış biçimini değiştirecekti. Amerika’nın keşfini izleyen birkaç yüzyıl içerisinde dünyanın tamamı sömürge imparatorlukları tarafından paylaşılacaktı. Atlantik ticareti ile gelişen Batı Avrupa Ülkeleri ile Yeni Dünya arasında kesintisiz ticaret ağları oluşacaktı. Ticaret yolları üzerindeki yegâne ulaşım aracı olan yelkenli gemiler, Sanayi Devrimi sonrası yerlerini daha hızlı ve güvenli yolculuk imkânı sunan buharlı gemilere bırakacaktı. Osmanlı Devleti; II. Mahmut Dönemi’nde tanıştığı buharlı gemilere çabuk adapte olmuştur. Balkan Savaşları’nın hemen öncesinde Osmanlı Devleti tarafından satın alınan Germanic/Gülcemal Vapuru, Türklerin sahip olduğu ilk transatlantik yolcu gemisidir. Uzun yıllar hizmet verecek olan Gülcemal, devrin birçok önemli hadisesine şahitlik edecekti

The frequency of interferon-gamma gene polymorphism in children with idiopathic thrombocytopenic purpura and the investigation of its relationship with clinical findings

Amaç: İdiopatik trombositopenik purpura (İTP), etyolojisi henüz bilinmeyen, sıklıkla iyi seyirli akkiz, otoimmün bir hastalıktır. Genetik zeminde çevresel faktörlerin etkisi ile ortaya çıkabileceği düşünülmektedir. İTP patogenezini aydınlatmaya yönelik birçok genetik çalışma yapılmıştır. Son yıllarda yapılmış bir çalışmada kronik İTP'li hastalarda özellikle interferon-gamma ilişkili genler ile Toll-benzeri reseptör genlerinin ekspresyonunun belirgin olarak arttığı saptanmıştır. Bu da İTP'nin genetik zeminde gelişen bir hastalık olduğu hipotezini desteklemektedir. İnterferon-gamma immünregülasyonda önemli rol oynayan bir proteindir. Ortamda interferon-gamma yüksek iken öncül T lenfositler TH1 yönünde değişmekte ve otoimmün hastalık gelişimine yatkınlık oluşturmaktadır. Sistemik lupus eritematozis (SLE), romatoid artrit ve kronik İTP gibi otoimmün hastalıklarda TH1/TH2 oranının arttığı bildirilmiştir. Ayrıca interferon-gamma ile ilişkili genlerde olan bazı yapısal değişikliklerin tip 1 diyabet, Hashimato tiroiditi, Graves hastalığı, multiple skleroz, romatoid artrit ve SLE gibi otoimmün hastalıkların gelişimine neden olabileceği, interferon-gamma geninin ilk intronundaki +874A/T polimorfizminin hastalık gelişimi ve klinik fenotipi etkileyebileceği rapor edilmiştir. Bu bilgiler ışığında çalışmamızda interferon-gamma +874A/T polimorfizminin İTP etyolojisindeki rolünü ve hastalığın klinik seyri ve tedavi yanıtındaki etkisini araştırmayı planladık. Hastalar ve yöntem: En az 6 aydır İTP tanısıyla izlenen 35 akut, 40 kronik İTP'li çocuk çalışmaya alındı. Kontrol grubunu 90 sağlıklı çocuk oluşturdu. ITP tanısı öykü, fizik muayene ve laboratuvar bulguları ile konuldu. Diğer trombositopeni yapabilecek durumlar dışlandı. Hasta ve kontrol grubundan 2 ml kan örneği %0.1 EDTA'lı steril tüpe alınarak -20°C'de depolandı. Tüm kan numunelerinin DNA izolasyonu yapıldı. İnterferon-gamma +874A/T polimorfizm sonuçları real-time PCR ve LightCyclerTM ile elde edildi. Bulgular: Akut İTP'li hastaların yaşları 6 ay-15 yaş (ortanca 7), kronik İTP'li hastaların yaşları 6 ay-18 yaş (ortanca 10,3) idi. Kronik İTP'li hastaların yaş ortalaması anlamlı olarak yüksekti (p=0,01). Tanı anında kronik İTP'li hastaların trombosit sayıları akut İTP'li hastalara göre yüksekti, ancak fark istatistiksel olarak anlamlı değildi (sırasıyla 17,7?18,29, 12,51?17,37, p=0,2). Tüm İTP'li hastalar arasında 21 hastada AA (%28), 35 hastada AT (%44,8) ve 19 hastada TT (%27,2) genotipi saptandı. Kontrol grubunda ise 47 hastada AA (%52,2), 36 hastada AT (%40) ve 7 hastada TT (%7,8) genotipi vardı. İTP'li hastalar ve kontrol grubu arasında genotip açısından anlamlı fark olduğu görüldü (p=0,001). Allel sıklığı açısından incelendiğinde İTP'li hastalarda A alleli 78 hastada (%52), T alleli 72 hastada (%48) mevcuttuæ kontrol grubunda A alleli 130 hastada (%72,2), T alleli 50 hastada (%27,8) saptandı. Aradaki fark anlamlı idi (p Çalışmaya alınan çocuklar akut İTP, kronik İTP ve kontrol grubu olmak üzere üç gruba ayrıldığında gruplar arasında AA, AT ve TT genotipi açısından anlamlı bir ilişki olduğu gözlendi (p=0,002). AA, AT, TT polimorfizmi genotip sıklıkları açısından akut İTP grubu ile kontrol grubu ve kronik İTP grubu ile kontrol grubu arasında anlamlı fark vardı (p=0,002, p=0,008). Akut İTP ve kronik İTP hastaları arasında anlamlı fark saptanmadı (p=0,285). Allel sıklığı açısından değerlendirildiğinde akut İTP ile kontrol grubu ve kronik İTP ile kontrol grubu arasında anlamlı fark bulunurken, akut İTP ve kronik İTP grupları arasında anlamlı fark saptanmadı (sırasıyla p=0,002, p=0,002, p=0,896). Kanama semptomlarının şiddeti (hafif, orta, ağır) ve interferon-gamma polimorfizmi arasındaki ilişki incelendiğinde istatistiksel olarak anlamlı bir ilişki saptanmadı (p=0,09). Ayrıca kronik İTP'li hastaların uzun dönem tedavi yanıtları ile interferon-gamma +874A/T gen polimorfizmi arasında anlamlı fark saptanmadı (p=0,568). Sonuç: İnterferon-gamma +874A/T polimorfizmi sıklığı akut ve kronik İTP'li olgularda kontrol grubuna göre anlamlı olarak yüksek bulundu ve diğer otoimmün hastalıklardaki literatür verileri de göz önüne alındığında +874A/T polimorfizminin bizim olgularımızda akut ve kronik İTP etyopoatogenezinde bir risk faktörü olabileceği düşünüldü. Idiopathic thrombocytopenic purpura (ITP) is an acquired, autoimmune, and frequently good prognostic disease in which the etiology is still unknown. It is suggested that the disease occurs with the influence of environmental factors under a genetic basis. There are many genetic studies which have been done to clarify the pathogenesis of ITP. A recent study showed that expression of Toll-like receptor and interferon-gamma associated genes is significantly increased in patients with chronic ITP. This study supports the hypothesis that ITP is a disease occurring under a genetic base. Interferon-gamma is an important protein which takes place in immunoregulation. When the amount of interferon-gamma is high, TH0 lymphocytes are converted to TH1 cells. This leads a predisposition to the occurrence of autoimmune disorders. The ratio of TH1/TH2 increases in many autoimmune disorders including SLE, RA, and chronic ITP. On the other hand, structural changes in interferon-gamma related genes are also associated with the development of autoimmune disorders, such as type 1 diabetes mellitus, Hashimato thyroiditis, Graves' disease, multiple sclerosis, rheumatoid arthritis, and SLE. +874A/T polymorphism in the first introne of interferon-gamma gene is associated with the development and clinical phenotype of these autoimmune diseases. The aim of this study is to investigate whether interferon gamma +874A/T polymorphism is a risk factor for the development of ITP, and whether it affects the clinical course and response to the treatment. Methods Thirty five patients with acute ITP and 40 patients with chronic ITP who were followed for at least 6 months were included. Control group consisted 90 healthy children. The diagnosis of ITP was established with history, physical examination and laboratory findings. Other causes of thrombocytopenia were excluded. Two millilitres of blood sample was taken into sterile tubes containing 0.1% EDTA from each child and all blood samples were stored at -20 until analysis. DNA was isolated from blood samples and interferon gamma +874A/T polymorphism was studied with real-time PCR and LightCyclerTM. Results The median age of patients with acute and chronic ITP was 7 years and 10.3 years, respectively. The mean age of patients with chronic ITP was significantly higher (p=0.01). The platelet counts of patients with chronic ITP at the time of diagnosis were higher compared to patients with acute ITP, but this was not statistically significant (p=0.2). Regarding all patients with ITP, 21 patients had AA, 35 patients had AT, and 19 patients had TT genotype. In the control group, 47 children had AA, 36 children had AT, and 7 children had TT genotype. There was a statistical difference between ITP and control group regarding the genotype (p=0.001). The frequency of A and T alleles in ITP group was 52% and 48%, respectively. The frequency of A and T alleles in control group was 72.7% and 27.8%, respectively. The frequency of allele distribution was statistically different between the ITP and control groups (p When the children were divided into three groups (acute ITP, chronic ITP and control group), there was a statistical significant difference between the groups regarding the AA, AT, and TT genotypes (p=0.002). There was a statistical significant difference between acute ITP and control group regarding the frequency of AA, AT, and TT gene polymorphisms (p=0.002). Similarly, there was a statistical significant difference between chronic ITP and control group regarding the frequency of AA, AT, and TT gene polymorphisms (p=0.008). There was no statistical difference between acute and chronic ITP groups (p=0.285). There was a statistical significant difference between acute ITP and control group regarding allele frequency (p=0.002). Similarly, there was a statistical significant difference between chronic ITP and control group regarding allele frequency (p=0.002). There was no statistical difference between acute and chronic ITP groups regarding allele frequency (p=0.896). There was no correlation between interferon gamma +874A/T polymorphism and severity of bleeding (mild, moderate and severe) (p=0.09). Again, there was no correlation between interferon gamma +874A/T polymorphism and response to lon term treatment in patients with chronic ITP (p=0.568). Conclusions In conclusion, there was a significant difference between patients with ITP and control group regarding interferon gamma +874A/T polymorphism and in the light of recent data involving other autoimmune disorders, we thought that interferon gamma +874A/T polymorphism may be a risk factor for ITP in our patient groups

MEME KANSERLİ 640 HASTADA HORMON RESEPTÖR DURUMU VE HER-2/neu DÜZEYİ İLE TEDAVİ SONUÇLARI ARASINDAKİ İLİŞKİ

Meme kanserinde tedavi yöntemlerinin saptanması, tedaviye yanıtın öngörülebilmesi ve tedavi sonuçlarının tahmin edilebilmesi amacı ile birçok prognostik faktörler bulunmaktadır. Bu prognostik faktörler içerisinde hormon reseptör durumu ve HER-2/neu düzeyleri kuşkusuz büyük öneme sahiptir. Bu çalışmada Gazi Üniversitesi Tıp Fakültesi Radyasyon Onkolojisi Anabilim Dalı’nda küratif amaçla radyoterapi uygulanan 640 meme kanserli hasta ÖR durumu, PR durumu, HER-2/neu düzeyleri ve bunların genel ve hastalıksız sağkalım üzerine olan etkileri yönünden incelenmiştir. Hastaların yaş aralıkları 20,8-79,4 yaş olup ortalama 49,7 olarak bulunmuştur. Hastalar ortalama 59,1 ay takip edilmiştir. Hasta gruplarında sağkalım analizleri amacı ile SPSS 16.0 versiyonu kullanılarak Kaplan-Meier yöntemi ile genel sağkalım ve hastalıksız sağkalım oranları bulunmuştur. Prognostik faktörlerin etkilerinin karşılaştırılması amacı ile Log Rank testi kullanılmıştır. İstatistik sonuçları herbir prognostik faktör için ayrı ayrı hesaplanmıştır. Östrojen reseptörü ve PR pozitifliğinin hem genel sağkalım hemde hastalıksız sağkalım oranlarını anlamlı derecede arttırdıkları saptanmış ve önemli prognostik faktörler oldukları gösterilmiştir. HER-2/neu aşırı salınımı ise genel ve hastalıksız sağkalımı olumsuz yönden etkilemektedir. Prognostik faktörler birlikte değerlendirildiğinde en kötü prognozun ÖR(-), PR(-), HER-2/neu(+) hastalar olduğu gösterilmiştir. Çalışma sonuçlarına dayanılarak ÖR, PR ve HER-2/neu düzeylerinin meme kanserinde büyük önem arzettiği gösterilmiş ve hasta takiplerinde dikkat edilmesi gereken faktörler olduğu belirtilmiştir.There was many prognostic factors for detection of treatment method, provide for treatment response and estimating treatment outcomes in breast cancer. Hormone receptor status and HER-2/neu levels have undoubtedly great importance in this prognostic factors. In this study, the ER status, PR status and HER-2/neu levels and their impact at overall and disease-free survival are evaluated in 640 patients with breast cancer who are curatively treated in Gazi University Faculty of Medicine, Radiation Oncology Department. The average age of patients are 49,7, range from 20,8- 79,4. The mean follow-up time was 59,1 months. The patients survival analysis were found with SPSS version 16.0 using Kaplan-Meier method for overall survival and disease-free survival. Log Rank test was used for the aim of comparison of prognostic factors. Statistical results were calculated seperately for each prognostic factor. Estrogen receptor and PR positivity were significantly increased both overall and disease-free survival and their importance for prognosis were shown. The over-expression of HER-2/neu was adversely affect overall and disease-free survival. While these prognostic factors evaluated together the worst prognosis has been shown in ER(-), PR(-), HER-2/neu(+) patients. Based on the study results, ER, PR and HER-2/neu levels have great importance in breast cancer and must be well considered in patients follow-up

Rektal kanserlerde radyoterapi planlaması

Radiotherapy can be applied more effectively on rectal cancer like other cancers as a result of tecnological advances in radiation oncology. Nowadays, the current approach is conformal tecniques. The target volume and critical organs at risk should be identified according to international criteria by making the best patient simulation. Three-dimensional treatment with multiple fields purposed for rectal cancer radiotherapy. Three fields often used as one posterior and two lateral fields. Four field "box" technique or other techniques are identified according to target volume differences. 45-50.4 Gy radiotherapy at convantional fractionation is required for treatment of microscopic disease. 5.4 Gy boost dose added to tumour or tumour bed by keeping the small bowel outside the high dose volume after 45 Gy radiotherapy to pelvis. The effect of the dose above 50.4 Gy is not clear for local control. The results of new studies should be expected for dose escalation and the use of advanced radiotherapy techniques. © 2013 Association of Oncology

Rektal kanserlerde radyoterapi zamanlamasi{dotless}

Presently, rectal cancer requires a multimodality approach to therapy. In this scheme, radiation therapy may play an important role in increasing the local control rate, improving disease-free and overall survival rates, and protection of organ function. Many studies have been conducted to improve treatment response rates. Radiation therapy schedule is the most studied issues among them. The advantages and disadvantages of preoperative radiotherapy when compared to postoperative administration have been studied in several phase II and phase III studies. In addition, it has been demonstrated that the preoperative approach increases the local control rates with a reduction in acute and late toxicity. Preoperative radiotherapy can be either applied as long-term or short-term. The main advantage of the long-term approach is that it can be applied with concomitant chemotherapy which results in higher response rates and complete pathological reduction. The aim of this review article is to summarize the evidence in literature and determine the most appropriate form of radiotherapy in the management of rectal cancer. © 2014 Association of Oncology