SrAuSi3 Ve SrAu2Si2 kristallerinin fiziksel özelliklerinin teorik olarak hesaplanması

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Geleneksel süperiletkenlerde kristal yapının tersinir simetrisi Cooper çiftlerinin biçimlenmesinde etkin rol oynarlar. Bu nedenle BaNiSn3-tipi c-ekseni boyunca tersinir simetrisi olmayan materyallerde süperiletkenliğin ortaya çıkmasıyla merkezi simetrik olmayan süperiletkenler hem teorik hem de deneysel açıdan oldukça güncel bir konudur. Ve yine aynı sebeple Hacim Merkezli Tetragonal BaNiSn3 yapıda kristalleşen yeni merkezi simetrik olmayan süperiletkenlerin keşfedilmesi için çok sayıda deneysel çalışma yapılmıştır. Bunun sonucunda SrAuSi3 malzemesinde süperiletkenlik keşfedildi. Her ne kadar süperiletkenlik deneysel olarak bulunmuş olsa da elektronik ve fonon özellikleri detaylı olarak incelenmemiştir. Fononlar ve elektronlar süperiletkenlik için çok önemlidirler, çünkü Bardeen-Cooper-Schrieffer'in BCS teorisinde açıklandığı gibi fononlar, Cooper çiftleri oluşumunda etkin rol oynarlar. Bu nedenle çok kuvvetli bir şekilde SrAuSi3 malzemesinde süperiletkenliğin anlaşılması için elektronik ve titreşim özelliklerin incelenmesinin şart olduğunu düşünüyoruz. Son yıllardaki çalışmalar, ilk-prensip hesaplamaların malzemelerin fiziksel ve kimyasal özelliklerinin araştırılmasında en uygun yöntem olduğunu göstermektedir. Bu nedenle SrAuSi3 ve SrAu2Si2 malzemelerinin yapısal, elektronik ve titreşim özelliklerinin ilk-prensip metodu ile incelemesinin faydalı olacağını düşünüyoruz. Bu materyallerin elektronik yapısını Fermi enerjisi yakınlarında inceleyeceğiz çünkü BCS teorisine göre Cooper çiftleri Fermi seviyesine yakın elektronlar tarafından oluşturulur. Bu sonuçların ışığında bu materyallerde fononların çalışılması için lineer tepki metodu uygulanacaktır. Bu materyallerde fonon dağılım eğrileri ve durum yoğunlukları detaylı olarak incelenecektir. Özel olarak alan-merkezi fonon modları farklı katıların örgü dinamiğinde farklı deneysel metotlarla elde edildiklerinden özel bir yer tutarlar. Bu nedenle alan-merkezli fonon modlarının özuzanımları bu materyallerde analiz edilecektir. Son olarak bu materyaller için Fermi seviyesinde durum yoğunlukları N(EF), Eliashberg spektral fonksiyonu α2F(ω), elektron-fonon etkileşim parametresi (λ) ve süperiletkenlik geçiş sıcaklığı (Tc) gibi parametrelerin hesaplanması için elektron-fonon etkileşimlerinin ab initio hesaplamaları yapılacaktır. Bu hesaplayacağımız süperiletkenlik parametreleri kullanarak bu materyallerde süperiletkenliğin kaynağı açıklanacaktır.The inversion symmetry of a crystal structure plays a central role in the formation of Cooper pairs in conventional super- conductors. Therefore, with the occurrence of superconductivity in BaNiSn3 type materials, which lacks inversion symmetry along the c-axis, noncentrosymmetric superconductors have considered as a hot topic of current research from both experimental and theoretical points of view. Thus, considerable experimental works have been made for the discovery of new noncentrosymmetric superconductors which crystallize in the body-centred tetragonal BaNiSn3 structure. Then, superconductivity has been discovered for SrAuSi3 material. Although superconductivity has been found experimentally, their electronic and phonon structures have not been studied in detail. Phonons and electrons are essential in the phenomenon of superconductivity because phonons play the role of bringing about the coupling between electrons to form Cooper pairs which are amenable for superconductivity, as explained in the Bardeen, Cooper, and Schrieffer (BCS) theory. Thus, we strongly believe that electronic and vibrational properties of SrAuSi3 material must be studied in order to understand the origin of superconductivity in this material. Recent years show that first-principles calculations offer an invaluable tool for carrying out theoretical studies of an important number of physical and chemical properties of the condensed matter with great accuracy. Therefore, we think that it is worthwhile to perform first-principles calculations for the structural and electronic properties the SrAuSi3 and SrAu2Si2. With the availability of these results, a linear response method will be applied to study phonons in these materials. Phonon dispersion curves and phonon density of states for these BaNiSn3 compounds will be presented and discussed in detail. In particular, the zone-centre phonon modes are of special interest in the lattice dynamics of solids since they can be obtained by various experimental methods. Thus, the eigendisplacement of zone-centre phonon modes in these materials will be analysed. Finally, we will carry out ab initio calculations of electron-phonon interaction for this material in order to calculate their superconducting parameters such as the density of states at the Fermi level (N(EF )), the Eliashberg spectral function (α2F(ω)), the electron-phonon coupling parameter (λ), and superconducting transition temperature (Tc). Using the calculated superconducting parameters, we will explain the origin of superconductivity in these material

Yüksek Dereceli Kasa İnvaze Olmayan Mesane Tümörlerinde Histolojik Derecelendirme Oranının Progresyona Etkisi

Aim: Histopathological classification is one of the main prognostic factors for non-muscle invasive bladder tumors (NMIBT). Weevaluated the relationship between tumor progression and the ratio of high-grade differentiation plus other routine pathologicalparameters in NMIBT.Materials and Methods: Ninety-two patients diagnosed with high grade NIMBT were analyzed between 2010-2018. Demographicinformation, tumor size, localization, multicentricity, and recurrence/progression situation were evaluated retrospectively. The high/lowgrade percentage ratio of tumor cells, tumor stage, differentiation, necrosis, lamina-propria invasion, lymphovascular invasion, andcarcinoma in-situ presence were also examined by two uro-pathologist. The effect on tumor progression was evaluated with pathologicalfindings.Results: Seventy-four (80.4%) of the patients were reported as T1 and 18 (19.6%) as Ta. The mean ratio of high-grade findings was11.9±8.5% and 69.5±28.1% for Ta and T1 patients, respectively(p25%, >50% and >75% was found to be 67(72.8%),54(58.7%) and 43(46.7%), respectively. The high-grade ratio for >25% was in only 1 Ta patient while it was in 66 of the T1patients(p75%(p50%(p=0.025).Conclusion: When evaluating the nuclear grade, defining tumors solely as high-grade leads to stratifying a highly heterogeneouspopulation in a single group. Higher rate of progression is observed in NIMBT patients with high-grade ratio >50%.KİOMT’de yüksek dereceli hücresel farklılaşma oranı ve diğer rutin patolojik parametrelerin progresyona etkisi değerlendirildi. Materyal ve Metot: Çalışmaya 2010-2018 yılları arasında transüretral mesane rezeksiyonu sonrası yüksek dereceli KİOMT tanısı alan 92 hasta dahil edildi. Hastaların demografik bilgileri, tümör çapı, lokalizasyonu, multisantrisitesi ve nüks/progresyon varlığı-süresi retrospektif olarak değerlendirildi. Ayrıca tümör hücrelerinin yüksek derece/düşük derece yüzdesi, tümör evresi, diferansiyasyon, nekroz, lamina propria invazyonu, lenfovasküler invazyon ve karsinoma in-situ varlığı iki üro-patolog tarafından incelendi. Elde edilen bulguların tümör progresyonu üzerine etkisi araştırıldı. Bulgular: Hastaların 74’ü(%80,4) T1, 18’i(%19,6) Ta olarak rapor edildi. Ta tanılı hastalarda yüksek derece oranı %11,9±8,5 iken, T1’lerde %69,5±28,1 olarak tespit edildi (p%25,>%50 ve>%75 olan hasta sayısının sırasıyla 67(%72,8), 54(%58,7) ve 43(%46,7) olduğu görüldü. Ta olan hastaların sadece 1’inde yüksek derece oranı>%25 olarak gözlenirken, T1 hastalarının 66’sında yüksek derece oranının>%25 olduğu belirlendi (p%75 olduğu görüldü. T1 yüksek derece oranları>%50 olan hastalarda progresyon, patolojik evresi T1 yüksek derece oranları %50 olan hastalarda progresyon anlamlı derecede artmaktadır

Van İli Çevresi Kabuk Deformasyon Analizi ve Deprem Tehlike Değerlendirmesi

Van ili ve çevresi, bölgesinde var olan güçlü tektonik hareketler ve deformasyonların etkisi altındadır. Bu deformasyonların esas kaynağını Arabistan levhasının Anadolu levhasına göre göreceli kuzey ve kuzey batı yönlü hareketi oluşturur. Bu bağıl hareket sonucunda Bitlis Zagros Kenet Kuşağı, Doğu Anadolu ve Kuzey Anadolu Fay sistemleri bölgenin depremselliğinde önemli rol oynamaktadır. Bölgede var olan gerilme analizlerinin belirlenmesi, Van ili ve çevresinde oluşacak deprem tehlikesini daha net ortaya çıkaracaktır. Bu bağlamda bölgede var olan GPS verileri ve Global CMT kataloğundan elde edilen depremsellik verileri kullanılarak çalışma alanında deformasyon oranı tespit edilmiştir. Buna göre çalışma alanında 40 n gerinim/yıl deformasyon alanı elde edilmiş, bölgesel gerilim içerisindeki bu küçük KB-GD sıkışma bileşeninin, 2011 Van depreminde olduğu gibi deprem mekanizmasında beklenenden daha büyük bir rol oynayabileceği saptanmıştır. Bölgede hâkim olan dilatasyon mekanizması incelendiğinde ise; Van ili ve çevresinde 25 n gerinim/yıl olan kesme bileşeni Karlıova bölgesine yaklaşıldıkça 170 n gerinim/yıl mertebesine erişmektedir. 2003 yılında bu bölgede meydana gelen Mw 6.4 Bingöl depreminin sağ yanal bir yapıda olması, Kuzey Anadolu Fay mekanizmasının Van ili civarına kadar uzanabileceğini işaret etmektedir. Bu alanda meydana gelebilecek büyük ölçekte deprem, Van Ovası’nda yerel zemin koşullarına bağlı olarak, yerleşim yerlerinde potansiyel tehlike oluşturabileceği ön görülmektedir

Pacemaker lead ilişkili ciddi triküspit stenozu ve ciddi COVID-19 pnömoni hikayesi: Olgu sunumu

Tricuspid stenosis occurs after the implantation of a ventricular pacemaker lead and is a rare complication. An inflammatory response is stimulated when the pacemaker leads are passing through the tricuspid valve which leads to fibrosis in the long-term. In our case report, we aim to present a patient with asymptomatic multiple pacemaker lead- related tricuspid stenosis and with a history of severe COVID-19 pneumonia.Triküspit stenozu ventriküler pacemaker lead implantasyonu sonrası gelişen ve nadir görülen bir komplikasyondur. Pacemaker lead triküspit kapağı geçtiğinde inflamatuvar yanıt gelişir ve bu durum uzun dönemde fibroz ile sonuçlanır. Bu olgu sunumunun amacı, ağır geçirilmiş COVID-19 pnömonisi ve pacemaker lead ilişkili asemptomatik ciddi triküspit stenozu olan bir olguyu sunmaktır

Combined metabolic activators improve cognitive functions in Alzheimer's disease patients: A randomised, double-blinded, placebo-controlled phase-II trial

Background: Alzheimer’s disease (AD) is associated with metabolic abnormalities linked to critical elements of neurodegeneration. We recently administered combined metabolic activators (CMA) to the AD rat model and observed that CMA improves the AD-associated histological parameters in the animals. CMA promotes mitochondrial fatty acid uptake from the cytosol, facilitates fatty acid oxidation in the mitochondria, and alleviates oxidative stress. Methods: Here, we designed a randomised, double-blinded, placebo-controlled phase-II clinical trial and studied the effect of CMA administration on the global metabolism of AD patients. One-dose CMA included 12.35 g L-serine (61.75%), 1 g nicotinamide riboside (5%), 2.55 g N-acetyl-L-cysteine (12.75%), and 3.73 g L-carnitine tartrate (18.65%). AD patients received one dose of CMA or placebo daily during the first 28 days and twice daily between day 28 and day 84. The primary endpoint was the difference in the cognitive function and daily living activity scores between the placebo and the treatment arms. The secondary aim of this study was to evaluate the safety and tolerability of CMA. A comprehensive plasma metabolome and proteome analysis was also performed to evaluate the efficacy of the CMA in AD patients. Results: We showed a significant decrease of AD Assessment Scale-cognitive subscale (ADAS-Cog) score on day 84 vs day 0 (P = 0.00001, 29% improvement) in the CMA group. Moreover, there was a significant decline (P = 0.0073) in ADAS-Cog scores (improvement of cognitive functions) in the CMA compared to the placebo group in patients with higher ADAS-Cog scores. Improved cognitive functions in AD patients were supported by the relevant alterations in the hippocampal volumes and cortical thickness based on imaging analysis. Moreover, the plasma levels of proteins and metabolites associated with NAD + and glutathione metabolism were significantly improved after CMA treatment. Conclusion: Our results indicate that treatment of AD patients with CMA can lead to enhanced cognitive functions and improved clinical parameters associated with phenomics, metabolomics, proteomics and imaging analysis. Trial registration ClinicalTrials.gov NCT04044131 Registered 17 July 2019, https://clinicaltrials.gov/ct2/show/NCT04044131

Combined metabolic activators improve metabolic functions in the animal models of neurodegenerative diseases

Background: Neurodegenerative diseases (NDDs), including Alzheimer's disease (AD) and Parkinson's disease (PD), are associated with metabolic abnormalities. Integrative analysis of human clinical data and animal studies have contributed to a better understanding of the molecular and cellular pathways involved in the progression of NDDs. Previously, we have reported that the combined metabolic activators (CMA), which include the precursors of nicotinamide adenine dinucleotide and glutathione can be utilized to alleviate metabolic disorders by activating mitochondrial metabolism. Methods: We first analysed the brain transcriptomics data from AD patients and controls using a brain-specific genome-scale metabolic model (GEM). Then, we investigated the effect of CMA administration in animal models of AD and PD. We evaluated pathological and immunohistochemical findings of brain and liver tissues. Moreover, PD rats were tested for locomotor activity and apomorphine-induced rotation. Findings: Analysis of transcriptomics data with GEM revealed that mitochondrial dysfunction is involved in the underlying molecular pathways of AD. In animal models of AD and PD, we showed significant damage in the high-fat diet groups' brain and liver tissues compared to the chow diet. The histological analyses revealed that hyperemia, degeneration and necrosis in neurons were improved by CMA administration in both AD and PD animal models. These findings were supported by immunohistochemical evidence of decreased immunoreactivity in neurons. In parallel to the improvement in the brain, we also observed dramatic metabolic improvement in the liver tissue. CMA administration also showed a beneficial effect on behavioural functions in PD rats. Interpretation: Overall, we showed that CMA administration significantly improved behavioural scores in parallel with the neurohistological outcomes in the AD and PD animal models and is a promising treatment for improving the metabolic parameters and brain functions in NDDs.PoLiMeR Innovative Training Network ; SNIC ; ScandiBio Therapeutics ; ScandiBio Therapeutics and Knut ; Knut och Alice Wallenbergs Stiftels

Combined metabolic activators improve cognitive functions in Alzheimer’s disease patients: a randomised, double-blinded, placebo-controlled phase-II trial

Background: Alzheimer’s disease (AD) is associated with metabolic abnormalities linked to critical elements of neurodegeneration. We recently administered\ua0combined metabolic activators (CMA) to the AD rat model and observed that CMA improves the AD-associated histological parameters in the animals. CMA promotes mitochondrial fatty acid uptake from the cytosol, facilitates fatty acid oxidation in the mitochondria, and alleviates oxidative stress. Methods: Here, we designed a randomised, double-blinded, placebo-controlled phase-II clinical trial and studied the effect of CMA administration on the global metabolism of AD patients. One-dose CMA included 12.35\ua0g L-serine (61.75%), 1\ua0g nicotinamide riboside (5%), 2.55\ua0g\ua0N-acetyl-L-cysteine (12.75%), and 3.73\ua0g L-carnitine tartrate (18.65%). AD patients received one dose of CMA or placebo daily during the first 28\ua0days and twice daily between day 28 and day 84. The primary endpoint was the difference in the cognitive function and daily living activity scores between the placebo and the treatment arms. The secondary aim of this study was to evaluate the safety and tolerability of CMA. A comprehensive plasma metabolome and proteome analysis was also performed to evaluate the efficacy of the CMA in AD patients. Results: We showed a significant decrease of AD Assessment Scale-cognitive subscale (ADAS-Cog) score on day 84 vs day 0 (P = 0.00001, 29% improvement) in the CMA group. Moreover, there was a significant decline (P = 0.0073) in ADAS-Cog scores (improvement of cognitive functions) in the\ua0CMA compared to the placebo group in patients with higher ADAS-Cog scores. Improved cognitive functions in AD patients were supported by the relevant alterations in the hippocampal volumes and cortical thickness based on imaging analysis. Moreover, the plasma levels of proteins and metabolites associated with NAD + and glutathione metabolism were significantly improved after CMA treatment. Conclusion: Our results indicate that treatment of AD patients with CMA can lead to enhanced cognitive functions and improved clinical parameters associated with phenomics, metabolomics, proteomics and imaging analysis. Trial registration\ua0ClinicalTrials.gov NCT04044131 Registered 17 July 2019, https://clinicaltrials.gov/ct2/show/NCT04044131

el-Ḳarâfî ve İstisna Hakkındaki Görüşleri

626 yılında Mısır’ın Behnesâ bölgesinin Bûş köyünde doğan Ḳarâfî’nin ilk eğitimi babası Şeyh İdris ile başlar. Babasından aldığı eğitimden sonra Sahibiyye, Kamhiyye ve Fazıliyye medreselerinde eğitim görmüştür. Asıl alanı fıkıh ve fıkıh usulü olan Ḳarâfî’nin bu ilimler dışında da çalışmaları mevcuttur. Nahiv alanında üç eser bırakmış ve bıraktığı bu eserlerdeki içeriklerden anlaşıldığına göre nahiv ekollerinden Basra ekolüne uymuştur. Bu eserlerden biri olan el-Ḫasâis adlı kitabında bazı konularda nahivcilerin çoğunluğunun kabul ettiği görüşleri eleştirmiş ve bu konularda kendi görüşünü ortaya koymuştur. el-İstiġna adlı eserinde ise istisna hakkında zengin bilgiler vermiş ve bazı konularda ilk sayılabilecek şeylere değinmiştir

The evaluation of FFR for interference management in coordinated hybrid terrestrial-aerial network

Recent works have tried to incorporate unmanned aerial vehicle (UAV) base stations in conventional networks, however, the inter-cell interference mitigation techniques for such networks have not been studied comprehensively. In this paper, we consider a new heterogeneous cellular network, where terrestrial base stations (TBSs) and low altitude platforms (LAPs) collaborate to construct a hybrid network. We believe that it can serve as the stepping stone to a full-fledged coordinated multi-point implementation for 5G and beyond networks. The proposed network is simple, open to improvement and also makes use of available TBS. It promises to increase minimum signal-to-interference ratio (SIR) value of users and also overall throughput by using fractional frequency reuse. The hovering LAP is used for edge users that have lower SIR than TBSs threshold. Furthermore, we simulated a few scenarios, analyzed the effect of radius and UAV altitude, found optimum values for both.Türkiye Bilimsel ve Teknolojik Araştırma Kurumu (TÜBİTAK

Effect of Intraluminal Thrombus Burden on the Risk of Abdominal Aortic Aneurysm Rupture

Abdominal aortic aneurysm (AAA) is a critical health disorder, where the abdominal aorta dilates more than 50% of its normal diameter. Enlargement in abdominal aorta alters the hemodynamics and flow-induced forces on the AAA wall. Depending on the flow conditions, the hemodynamic forces on the wall may result in excessive mechanical stresses that lead to AAA rupture. The risk of rupture can be predicted using advanced computational techniques such as computational fluid dynamics (CFD) and fluid–structure interaction (FSI). For a reliable rupture risk assessment, formation of intraluminal thrombus (ILT) and uncertainty in arterial material properties should be taken into account, mainly due to the patient-specific differences and unknowns in AAAs. In this study, AAA models are computationally investigated by performing CFD simulations combined with FSI analysis. Various levels of ILT burdens are artificially generated in a realistic AAA geometry, and the peak effective stresses are evaluated to elucidate the effect of material models and ILT formation. The results indicate that increasing the ILT burden leads to lowered effective stresses on the AAA wall. The material properties of the artery and ILT are also effective on the stresses; however, these effects are limited compared to the effect of ILT volume in the AAA sac