Vibrational Behavior of Metal Nanowires under Tensile Stress

We have investigated the vibrational density of states (VDOS) of a thin Cu nanowire with $$ axial orientation and considered the effect of axial strain. The VDOS are calculated using a real space Green's function approach with the force constant matrices extracted from interaction potential based on the embedded atom method. Results for the vibrational density of states of a strain-free nanowire show quite distinctive characteristics compared to that of a bulk atom, the most striking feature of which is the existence of high frequency modes above the top of the bulk spectrum. We further predict that the low frequency characteristics of the VDOS reveal the quasi-1 dimensional (Q1D) behavior only when the wire is extremely thin. Through decomposition of VDOS into local atoms we also exhibit that while the anomalous increase in low frequency density of states is mainly due to the corner atoms, the enhancement in high frequency modes is primarily moderated by core atoms. We, additionally, find that while the high frequency band above the top of the bulk phonon shifts to higher frequencies, the characteristics at low frequencies remains almost the same upon stretching the nanowire along the axial direction

CT taramalarında absorbe edilen dozun hastanın boyuna göre değişimi

Kanser tedavilerinde çekilen Bilgisayarlı Tomografi (CT) görüntüleri, tedavi portalı tasarımı ve planlamasında önemlidir. Hastanın CT taramalarında aldığı doz, tedavi planlaması doz hesaplamasında dikkate alınmaz ve kritik doz eşiğine sahip kritik organların sınır dozlarının hesaplanmasında önem kazanır. Bu çalışmada bazı kritik organlar olan kalp, karaciğer ve böbreklerin hastanın boyuna göre aldığı dozun değişimi Monte Carlo tekniği kullanılarak NCICT kodu ile araştırıldı. Sonuç olarak, dozlar hastaların boyuna göre değiştirildi.Computed Tomography (CT) images taken in cancer treatments are important in treatment portal design and planning. The dose received by the patient in CT scans are not considered in the treatment planning dose calculation and becomes important in calculating the limit doses of the critical organs with critical dose threshold. In this study, the change of the dose received by some of the critical organs, namely the heart, liver, and kidneys, according to the height of the patient was investigated with the NCICT code using the Monte Carlo technique. As a result, doses were changed by the height of the patients

Content based network model with duplication and divergence

We construct a minimal content-based realization of the duplication and divergence model of genomic networks introduced by Wagner [A. Wagner, Proc. Natl. Acad. Sci. {\bf 91}, 4387 (1994)] and investigate the scaling properties of the directed degree distribution and clustering coefficient. We find that the content based network exhibits crossover between two scaling regimes, with log-periodic oscillations for large degrees. These features are not present in the original gene duplication model, but inherent in the content based model of Balcan and Erzan. The scaling exponents $\gamma_1$ and $\gamma_2=\gamma_1-1/2$ of the Balcan-Erzan model turn out to be robust under duplication and point mutations, but get modified in the presence of splitting and merging of strings. The clustering coefficient as a function of the degree, $C(d)$, is found, for the Balcan-Erzan model, to behave in a way qualitatively similar to the out-degree distribution, however with a very small exponent $\alpha_1= 1-\gamma_1$ and an envelope for the oscillatory part, which is essentially flat, thus $\alpha_2= 0$. Under duplication and mutations including splitting and merging of strings, $C(d)$ is found to decay exponentially.Comment: 12 pages, 6 figure

Female prime minister Tansu Çiller's policy on women: an assessment based on basic laws

Dünyada İnsan haklarının ve sosyal demokrasinin gelişmesi kadın haklarına verilen önem ile doğrudan ilişkili bir durumdur. Bu açıdan bakıldığında kadın hakları ile ilgili sorunların çözümüne yönelik çabalara yönelmek hükümetler açısından kaçınılmaz bir görevdir. Genel olarak, kadınların siyasal alanda etkin bir şekilde temsillerinin sağlanması bu yöndeki çabaların artacağı yönünde bir umut uyandırmaktadır. Ancak kadınların aktif siyaset alanında göstermiş oldukları eğilimler bazen de bu yöndeki umutları boşa çıkarmaktadır. Bu araştırmada söz konusu bu durum Türkiye'nin şimdiye kadar ki tek kadın başbakanı unvanını taşıyan Tansu Çiller örneğinde döneminde çıkarılan temel yasalar üzerinden açıklanmıştır. Araştırma, literatüre dayalı araştırmalar bağlamında tarihsel ve betimsel yöntemler kullanılarak yapılandırılmıştır. Araştırma ülkenin tek başbakan konumundaki bir liderin kadın politikalarına bakış açısını ortaya koyması ve kadın haklarına yönelik politika başarısızlıklarını kadın siyasetçilerin politika yapma tarzı ile ilişkilendirmesi bakımından önem taşımaktadırThe development of human rights and social democracy in the world is directly related to the importance given to women's right, s. From this point of view, it is an inevitable task for governments to tackle the struggle to solve the problems of women's right, s. In general, the provision of women's representation in the political arena effectively proves the hope that these efforts will increase. However, women's tendencies in active politics sometimes dismiss prospects in this direction. In this research, this situation is explained by the basic laws issued during the period of Tansu Çiller, which is the only woman prime minister of Turkey until now. The research is structured using historical and descriptive methods in the context of literature based research. It is important for the research country to set a single prime minister's point of view on women's policies as well as to link policy failures for women's rights with the politics of women politician

Female Prime Minister Tansu Çiller's Policy on Women: An Assessment Based on Basic Laws

Dünyada İnsan haklarının ve sosyal demokrasinin gelişmesi kadın haklarına verilen önem ile doğrudan ilişkili bir durumdur. Bu açıdan bakıldığında kadın hakları ile ilgili sorunların çözümüne yönelik çabalara yönelmek hükümetler açısından kaçınılmaz bir görevdir. Genel olarak, kadınların siyasal alanda etkin bir şekilde temsillerinin sağlanması bu yöndeki çabaların artacağı yönünde bir umut uyandırmaktadır. Ancak kadınların aktif siyaset alanında göstermiş oldukları eğilimler bazen de bu yöndeki umutları boşa çıkarmaktadır. Bu araştırmada söz konusu bu durum Türkiye'nin şimdiye kadar ki tek kadın başbakanı unvanını taşıyan Tansu Çiller örneğinde döneminde çıkarılan temel yasalar üzerinden açıklanmıştır. Araştırma, literatüre dayalı araştırmalar bağlamında tarihsel ve betimsel yöntemler kullanılarak yapılandırılmıştır. Araştırma ülkenin tek başbakan konumundaki bir liderin kadın politikalarına bakış açısını ortaya koyması ve kadın haklarına yönelik politika başarısızlıklarını kadın siyasetçilerin politika yapma tarzı ile ilişkilendirmesi bakımından önem taşımaktadırThe development of human rights and social democracy in the world is directly related to the importance given to women's right, s. From this point of view, it is an inevitable task for governments to tackle the struggle to solve the problems of women's right, s. In general, the provision of women's representation in the political arena effectively proves the hope that these efforts will increase. However, women's tendencies in active politics sometimes dismiss prospects in this direction. In this research, this situation is explained by the basic laws issued during the period of Tansu Çiller, which is the only woman prime minister of Turkey until now. The research is structured using historical and descriptive methods in the context of literature based research. It is important for the research country to set a single prime minister's point of view on women's policies as well as to link policy failures for women's rights with the politics of women politician

Multiple evanescent white dot syndrome presenting that as central serous chorioretinopathy

A 28-year-old man presented to the clinic with metamorphopsia, central scotoma, and visual loss in his right eye. After detailed ophthalmicexamination, fundoscopy showed localized elevation of the macula,and optical coherence tomography also showed subretinal serofi brinousaccumulation temporal to the fovea. He was evaluated as idiopathic central serous chorioretinopathy (CSCR). At the fi fth day of presentationhe was seen by the retinal consultant with fl uorescein angiography (FA) and indocyanine green angiography (ICGA) which were characteristicof multiple evanescent white dot syndrome (MEWDS) in the right eye. The diagnosis was changed as MEWDS presenting that as CSCR, andit was seen that the serofi brinous elevation began to decline after the fi rst week of presentation. Symptoms and visual disturbance recoveredwithout any further treatment at sixth month in this case

Santral Seröz Koryoretinopati Şeklinde Prezente Olan Multipl Geçici Beyaz Nokta Sendromu

A 28-year-old man presented to the clinic with metamorphopsia, central scotoma, and visual loss in his right eye. After detailed ophthalmicexamination, fundoscopy showed localized elevation of the macula,and optical coherence tomography also showed subretinal serofi brinousaccumulation temporal to the fovea. He was evaluated as idiopathic central serous chorioretinopathy (CSCR). At the fi fth day of presentationhe was seen by the retinal consultant with fl uorescein angiography (FA) and indocyanine green angiography (ICGA) which were characteristicof multiple evanescent white dot syndrome (MEWDS) in the right eye. The diagnosis was changed as MEWDS presenting that as CSCR, andit was seen that the serofi brinous elevation began to decline after the fi rst week of presentation. Symptoms and visual disturbance recoveredwithout any further treatment at sixth month in this case.Yirmisekiz yaşında erkek hasta metamorfopsi, santral skotom ve görme kaybı ile kliniğimize başvurdu. Detaylı oftalmolojik muayenede fundusta makulada lokalize seröz dekolman, optik koherens tomografi ile de foveanın temporalinde subretinal seröfi brinöz birikim tespit edildi ve hastamız idiopatik santral seröz koryoretinopati (SSKR) tanısı ile retina bölümüne yönlendirildi. Beşinci günde tekrar görülen hastanın fundus fl öresein ve indosiyanin yeşili anjiografi sinde multipl geçici beyaz nokta sendromuna (MGBNS) karakteristik bulgular saptandı. Hastanın tanısı SSKR şeklinde prezente olan MGBNS olarak değiştirildi. Birinci haftadan sonra seröfi brinöz elevasyon azalmaya başladı. Semptomlar ve görme bozukluğu 6. ayın sonunda hiçbir tedavi gerektirmeden tamamiyle düzeldi

Effect of Topical Nepafenac on Macular Thickness in Eyes with Diabetic Macular Edema without Previous Treatment

Amaç: Diyabetik maküla ödemi olan hastalarda topikal nepafenak damla kullanımının maküla kalınlığına etkisinin optik koherans tomografi ile değerlendirilmesi.Gereç ve Yöntem: Mart 2011- Haziran 2015 tarihleri arasında retina biriminde değerlendirilen ve ilk kez makulopati tanısı konan intravitreal enjeksiyon ya da lazer tedavisini kabul etmeyen/uygun olmayan ve günde 4 kez topikal %0,1'lik nepafenak damla başlanılan tip 2 diyabetli hastalar çalışmaya dahil edildi. Yaşa bağlı maküla dejenerasyonu, glokom, üveit ve oküler cerrahi öyküsü olan hastalar ile optik koherans tomografi ölçümleri alınamayanlar ve ödemi maküla santrali dışında olanlar çalışma dışı bırakıldı. Hastalara tam kapsamlı oftalmik muayene, optik koherans tomografi ve gerekli durumlarda flöresein anjiyografi yapıldı. Topikal tedavi öncesi ve sonrasındaki 1.,3. ve 6. ay bulguları değerlendirildi. Bulgular: Yirmisekizi erkek, 48 hastanın 48 gözü çalışmaya dahil edildi. Topikal tedavi öncesi en iyi düzeltilmiş görme keskinliği ortalaması 0,61±0,33, tedavi sonrası 1.,3. ve 6. ay görmeleri sırasıyla 0,61±0,32; 0,59±0,30 ve 0,57±0,30 idi. Değerler arasında istatistiksel olarakanlamlı fark yoktu. Tedavi öncesi ve sonrası 1.,3. ve 6. ay takiplerde santral fovea kalınlığı sırasıyla 323,81±92,94, 33,56±107,36,335,93±105,55 ve 326,58±99,70 µm idi. Değerler arasında istatistiksel olarak anlamlı fark yoktu (p=0,562). Diğer kadranlarda da kalınlık değerleri takipler esnasında anlamlı farklılık göstermedi (p>0,05). Sonuç: Santral tutulumlu diyabetik maküla ödeminde topikal nepafenak kullanımı 6 aylık takipte maküla kalınlığında ve görme düzeyindeherhangi bir değişimle sonuçlanmamıştır. Kalınlıkta artışın olmaması kan şekeri regülasyonuyla birlikte topikal NSAİ damla kullanımının uygun tedavi uygulanamayan hastalarda güvenli ve denenebilir olduğunu göstermektedir.Objective: Evaluation of the effect of topical nepafenac on macular retinal thickness in eyes with diabetic macular edema via optical coherence tomography. Material and Method: This study included patients who were admitted to our retinal disease section between 2011 March and 2015 June with type 2 diabetes that had been diagnosed as having macular edema for the first time. All patients received topical nepafenac (qid) treatment as they did not accepted or had suitable health conditions for intravitreal injections and laser treatment. Patients that had age related macular degeneration, glaucoma, uveitis, edema not involving fovea and cases that lack optical coherence tomography accurate reports due to media opacities were excluded. All cases had complete ophthalmic and optical coherence tomography examinations at the initial evaluation and in the 1st, 3rd and 6th month during treatment. Fluorescein angiography was performed if necessary. Results: One eye of 48 patients (28 male, 20 female) were evaluated, the mean best corrected visual acuity was 0.61±0.33, 0.61±0.32; 0.59±0.30, and 0.57±0.30 at the initial examination and 1st, 3rd and 6th month during treatment respectively. There was no statistical significant difference between best corrected visual acuity values. Mean central foveal thicknesses on optical coherence tomography were 323.81±92.94, 33.56±107.36, 335.93±105.55, and 326.58±99.70 µm at the initial examination and 1st, 3rd and 6th month during treatment respectively. There was no statistical significant difference between foveal thickness values (p= 0.562). Also no statistical significant changes were found during the study in the outer macular quadrants in terms of retinal thickness values (p>0.05). Conclusion: No significant changes were found in terms of macular thicknesses or visual acuity in eyes with diabetic macular edema with topical nepafenac treatment during 6 months follow-up. The lack of edema progression suggests that topical nonsteroidal anti-inflammatory treatment together with systemic regulation of diabetes may be a safe alternative in patients that other treatment modalities cannot be applied

Correlation of ocular pulse amplitude, choroidal thickness, and internal carotid artery doppler ultrasound findings in normal eyes

Introduction: The choroid receives about 65-85% of ocular blood flow, which comes from the ophthalmic artery (OA), the first branch of the internal carotid artery (ICA). In the foveal avascular zone, there is no retinal vascular supply; therefore, choroidal blood supply plays a significant role in this subfoveal region. The ocular pulse amplitude (OPA) provides useful information about intraocular blood flow and is an indirect indicator of choroidal perfusion. In this study, we aimed to assess the correlation between the OPA, subfoveal choroidal thickness (CT), and ICA Doppler ultrasound findings in healthy eyes. Methods: In total, 48 eyes of 48 healthy volunteers were included in this study. All eyes underwent detailed ophthalmic evaluation, including slit-lamp biomicroscopy, fundus examination, axial length, OPA measurements, and optical coherence tomography (OCT) with enhanced depth imaging mode. Carotid Doppler ultrasound examination was performed by the radiologist. The correlation between the OPA, subfoveal CT, and ICA Doppler findings [peak systolic velocity (PSV) and enddiastolic velocity (EDV)] were evaluated, considering gender and age. Results: The mean OPA was 3.06 +/- 1.34 mmHg. The mean subfoveal CT was 305.85 +/- 33.98 mu m. The mean PSV and EDV of ICA were 73.25 +/- 23.63 cm/s and 26.93 +/- 13.42 cm/s, respectively. A moderate positive correlation was found between OPA and subfoveal CT (p = 0.001; rho = 0.481). This relationship was present in both men and women. While a positive correlation was found between the OPA and subfoveal CT in subjects under the age of 50 years, there was no correlation in those over the age of 50 years. Conclusions: A fair correlation was found between the OPA and subfoveal CT in healthy subjects under the age of 50