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Distance-normal congruence of rotational surfaces in euclidean 3-space
No full textIn this study, we considered simple linear congruences of some curves/surfaces to generate parametric families of curves/surfaces. The method depends essentially on the position vector of a curve/surface and its signed unit normal. The shape of the normal congruence of the curve/surface can be predictably changed based on the sign of its unit normal. On the other hand, symmetry of surfaces refers to invariance under transformations such as reflections, rotations, or translations, which can also involve normal congruence. Considering the normal congruences of the surface of revolution to be minimal, some results on the meridian curves are obtained. Furthermore, some surface models are constructed over the meridian curves
Evaluation of β-thalassemias in the premarital hemoglobinopathy screening program: A retrospective study
No full textObjective: To retrospectively evaluate B-thalassemias in the premarital hemoglobinopathy screening program in primary care. Methods: The retrospective study was carried out in Bursa Uludag University Family Health Center in Turkey between 1-30 September 2023. In the study, the data of individuals who applied to the Family Health Center for premarital health examination within the four years between January 1, 2019, and December 31, 2022, were taken from the database and evaluated retrospectively. Family history of hemoglobinopathy, sociodemographic findings, existing diseases, allergies, cancer, and genetic disease conditions were obtained. Complete blood count, and high-performance liquid chromatography (HPLC) results were examined. P-values below 0.05 were considered statistically significant. Analyzes were made in the SPSS 25.0 program. Results: A total of 327 people, 171 men (52.3%) and 156 (47.7%) women, participated in the study. It was determined that the age of the individuals was 30.17 +/- 6.16. The average Mentzer index levels were found to be 12.95 +/- 4.56. Places of birth are Mediterranean with 8.3% and other regions with 91.7%. B-thalassemia type detected in family medicine was suspected with a rate of 1.5% and carrier with a rate of 0.6%. The rate of patients referred to a hematologist was found to be 2.1%. The rate of patients with a definitive diagnosis was determined as 1.8%. It was determined that B-thalassemia definitive diagnosis rates were higher in groups whose place of birth was the Mediterranean region, with a family history of thalassemia, with a diagnosis of cancer, and with a genetic, allergic, and chronic disease diagnosis (p=0.01). Conclusion: Although it is not located in the Mediterranean region, the high prevalence of B-thalassemia in our population and its relationship with diseases are important. We emphasize the importance of a premarital screening program for the diagnosis of B-thalassemia due to its increasing frequency and complications in the globalizing world
Investigation of the regulatory effects of long non-coding RNAs on polycomb suppressor complex 2 in atypical teratoid rhabdoid tumor in vıtro and retrospectively
No full textAtipik teratoid / rabdoid tümör (AT/RT), merkezi sinir sisteminin (MSS) nadir ve agresif pediatrik bir beyin tümörüdür. AT/RT patogenezinde ana olay, SWI/SNF kromatin yeniden modelleyici kompleksin üyesi SMARCB1 proteinini kodlayan gendeki kayıp sonucu bu proteinin antagonistiği polikomb baskılayıcı kompleks 2 (PRC2) alt birimi enhansır zeste homolog 2 (EZH2)’nin anormal üretimi ve tümör baskılayıcı gen bölgelerinin histon 3’ün 27. lizin kalıntısında istenmeyen trimetilasyon (H2K27me3) birikimi gerçekleşmesidir. H3K27me3 birikiminin önüne geçebilmek için tazemetostat bileşiği faz çalışmaları devam eden bir EZH2 inhibitörüdür. Farklı kanserlerin PRC2 aktivitesinde EZH2’ye bağlanabilen uzun kodlanmayan RNA’ların (LncRNA), kompleksi genlere yönlendirilerek H3K27me3 oluşumundaki önemi tanımlanmış olmasına rağmen AT/RT’de PRC2’nin lncRNA temeli bilinmemektedir. Mevcut tez çalışmasında EZH2’ye bağlı lncRNA’ların tanımlanması ve etkinliklerinin araştırılması ve lncRNA MALAT1’in inhibisyonuyla H3K27me3 seviyeleri başta olmak üzere hücrelerin agresifliğinde etkili migrasyon, invazyon ve tümör boyutu üzerindeki etkilerinin tazemetostat ile kıyaslanarak araştırılması hedeflenmiştir. Bu amaç ve hedefler doğrultusunda EZH2 proteinine bağlı lncRNA’ları belirlemek için RNA immünopresipitasyon (RIP) yöntemi kullanılmıştır. MALAT1 inhibitörü ve tazemetostat varlığında, H3K27me3 seviyelerindeki değişkenlik immünofloresan yöntemi ile, kanser hücrelerinin agresifliğine etkisi yara iyileşmesi, transwell sistem invazyon testi ve 3D tümör oluşturabilme deneyleri ile araştırılmıştır. İn vitro araştırmalar, AT/RT tanısı almış 10 hastanın tümör doku örneklerindeki lncRNA seviyeleri ile klinikopatolojik verileri arasındaki ilişkilendirme çalışmasıyla klinik düzeyde desteklenmiştir. Sonuçta, nadir bir beyin tümörü AT/RT için ilk defa PRC2 aracılı lncRNA düzenlemesinin önemi agresiflik ve klinikopatolojik açıdandan değerlendirilmiştir. Ayrıca, bu lncRNA’lardan MALAT1’i hedeflemenin AT/RT için EZH2 aracılı PRC2 inhibisyonuna alternatif terapötik hedef olabileceği gösterilmiştir.Atypical teratoid/rhabdoid tumor (AT/RT) is a rare and aggressive pediatric brain tumor of the central nervous system (CNS). The main event in the AT/RT pathogenesis is the abnormal production of polycomb repressor complex 2 (PRC2) subunit enhansir zeste homolog 2 (EZH2), which is antagonistic to this protein as a result of the loss of the gene encoding SMARCB1, a member of the SWI/SNF chromatin remodeling complex, and unwanted trimethylation (H2K27me3) accumulation of tumor suppressor gene regions at the lysine residue 27. of histone 3. In order to prevent the accumulation of H3K27me3, the tazemetostat compound is an EZH2 inhibitor whose phase studies are ongoing. Although the importance of long non-coding RNAs (LncRNA) that can bind to EZH2 in the PRC2 activity of different cancers in the formation of H3K27me3 has been identified by directing the complex to genes, the lncRNA basis of PRC2 in AT/RT is unknown. In the current thesis, it was aimed to identify and investigate the effectiveness of lncRNAs related to EZH2 and to investigate the effects of inhibition of lncRNA MALAT1 on the aggressiveness of cells, especially H3K27me3 levels, effective migration, invasion and tumor size by comparing with tazemetostat. In line with these goals and objectives, RNA immunoprecipitation (RIP) method was used to determine the lncRNAs bound to the EZH2 protein. In the presence of MALAT1 inhibitor and tazemetostat, the variability in H3K27me3 levels was investigated by immunofluorescence method, its effect on the aggressiveness of cancer cells by wound healing, transwell system invasion test and 3D tumor formation experiments. In vitro research was supported at the clinical level by the correlation study between lncRNA levels and clinicopathological data in tumor tissue samples of 10 patients diagnosed with AT/RT. As a result, the importance of PRC2-mediated lncRNA regulation for a rare brain tumor AT/RT has been evaluated for the first time in terms of aggressiveness and clinicopathology. It has also been shown that targeting MALAT1 from these lncRNAs may be the alternative therapeutic target to EZH2-mediated PRC2 inhibition for AT/RT
Evaluation of metabolism-related molecules in rat model of autism spectrum disorders
No full textAutism spectrum disorders (ASD) are neurodevelopmental pathologies. Investigating both sexes is crucial for understanding sex-specific manifestations of ASD. This study aims to examine ASD-like behaviours and metabolic alterations in male and female rats prenatally exposed to valproic acid (VPA). Pregnant Wistar albino rats were administered 400 mg/kg VPA or saline on embryonic day 12. Pups were subjected to various behavioural tests, including olfactory discrimination, sociability, locomotion, anxiety and exploratory behaviour assessments. On postnatal day 35, pups were sacrificed, and blood glucose levels were measured. Serum and brain leptin, orexin-A, nesfatin-1 and ghrelin levels were assessed by the ELISA method. VPA-exposed pups exhibited increased latency to reach maternal bedding, reduced sociability, decreased locomotion and increased immobility in both sexes. In the elevated plus maze, VPA-exposed females showed an increase in open-arm entries, while males showed a reduction compared to control groups. Blood glucose levels were significantly elevated in VPA-exposed males but not females. Significant sex-independent changes were observed in serum and brain levels of leptin and nesfatin-1 in the VPA groups. Brain orexin-A and serum ghrelin levels were altered in the VPA group in a sex-dependent manner. Prenatal VPA exposure induces ASD-like symptoms in both sexes, with notable sex-specific differences in behaviour and metabolic regulation. These findings highlight the importance of including both sexes in ASD research to better understand sex-dependent characteristics of the disorder, particularly concerning metabolic dysregulation
Investigation of the effect of geometry on the strength performance of sandwich panels
No full textGünümüzde sürdürülebilirlik kavramının önemli hale gelmesi ile mühendislik alanında yeni tasarım konseptleri ortaya atılmaktadır. Minimum ağırlık ile daha yüksek mekanik performansların sağlanması amacı ile geliştirilen kompozit sandviç panel yapılar yeni bir araştırma alanı sağlamaktadır. İki yüksek mukavemetli ince panel arasına yerleştirilen hafif, oluklu bir çekirdekten oluşan sandviç paneller, gelişen üretim teknolojileri sayesinde farklı tasarım ve uygulama olanakları sunmaktadır. Bu çalışmada sandviç panel geometrilerinin, dayanım performanslarına etkisinin incelenmesi amaçlanmıştır. Literatür araştırması sonrasında seçilen kare, trapez ve sinüs çekirdek kesite sahip yapılar tasarlandıktan sonra statik analizler yapılıp, mekanik davranışlar incelendi. Sandviç panelde oluklu çekirdek dökme poliamid (Pa6) ve yüzey panelleri Al 6063-T5 malzemesinden oluşmaktadır. Tasarım parametreleri yüzey katmanlarının kalınlığı, çekirdek kalınlığı ve çekirdek yüksekliği seçildi. Aynı koşullar altında trapez sandviç panelin, daha yüksek yük ve emilen enerjiye sahip olduğu görülmüştür. Ayrıca aynı koşullar altında çekirdek kalınlığında yapılan iyileştirmeler, ağırlıkta daha az bir artış sağlayıp daha yüksek yük ve emilen enerji vermiştir. Analizler sonucunda en uygun performansı veren 1,5 mm çekirdek kalınlığına göre 3D yazıcı ile PLA malzemesinden sandviç paneller üretildi. Üretilen panellere basma testleri yapıldı. Test ve analiz sonuçları karşılaştırılmış olup malzemeden bağımsız olarak, uygun bir malzemede, panel geometrilerinde yapılan değişiklikler ile mekanik performanslarının önemli derecede iyileştirilebileceği görülmüştür.With the increasing importance of the concept of sustainability today, new design concepts have emerged in the field of engineering. Composite sandwich panel structures, developed to achieve higher mechanical performance with minimal weight, have provided a new area of research. Sandwich panels, consisting of a lightweight corrugated core placed between two high-strength thin face sheets, offer various design and application possibilities due to advancements in manufacturing technologies. This study aims to investigate the effect of sandwich panel geometries on strength performance. After a literature review, structures with square, trapezoidal, and sinusoidal core cross-sections were designed, followed by static analyses to examine their mechanical behavior. The sandwich panel consists of a corrugated core made of cast polyamide (PA6) and face sheets made of Al 6063-T5 material. The design parameters were selected as the thickness of the face layers, core thickness, and core height. Under the same conditions, the trapezoidal sandwich panel exhibited higher load and absorbed energy. Additionally, improvements in core thickness provided higher load and absorbed energy with a minimal increase in weight. As a result of the analyzes, sandwich panels were produced from PLA material with a 3D printer according to the core thickness of 1.5 mm, which gives the most suitable performance. Compression tests were performed on the produced panels. The test and analysis results were compared and it was seen that the mechanical performance of the panels can be significantly improved with changes in panel geometries in a suitable material, regardless of the material
Atmospheric polycyclic aromatic hydrocarbon concentrations in a semi-urban site: Temporal variation, risk assessment, source identification, and estimation of levels in diverse environments
No full textThis study evaluates atmospheric polycyclic aromatic hydrocarbon (PAH) concentrations in a semi-urban area, G & ouml;r & uuml;kle, Turkey, from June 2021 to February 2022. The average concentration of & sum;16 PAHs was 24.85 +/- 19.16 ng/m3, ranging from 6.70 to 59.11 ng/m3. Seasonal variations were observed, with winter concentrations approximately five times higher than those in summer, driven by increased residential heating emissions and adverse meteorological effects. The results were compared to literature values, revealing lower PAH levels than those found in other urban and industrial areas. Meteorological factors were statistically analyzed. Polycyclic aromatic hydrocarbon concentrations exhibited an inverse relationship with temperature and mixing height, while relative humidity showed a positive linear correlation. The study also estimated PAH concentrations in various environmental media using gas-particle partitioning and equilibrium models. The concentrations of PAHs in the particulate phase were minimal, suggesting that most PAHs were present in the gas phase. Additionally, the equilibrium concentrations of PAHs in soil, leaves, bark, and water were modeled, emphasizing the accumulation of heavier PAHs in these media yet 2- and 3-ring PAHs were predominant in the ambient air samples. Source apportionment and principal component analysis studies identified vehicle emissions and combustion for heating purposes as the primary sources of pollution. However, air mass trajectory analysis indicated contributions from Kocaeli, an area with significant industrial activity. The cancer risk assessment yielded low risks for both adults and children
Investigation of the effects of abscisic acid on epithelial mesenchymal transition and cell adhesion in prostate cancer cells
No full textProstat kanseri, dünya genelindeki erkeklerde oldukça yaygın bir şekilde gözlenen ve sağkalım oranı düşük olan bir kanser türüdür. Prostat bezinde gelişen bu kanser hücreleri oldukça agresif şekilde çoğalmakla birlikte metastaz yeteneği yüksek bir kanserdir. Tümör hücrelerinin metastaz yapabilmesi ve diğer dokulara yayılım göstermesi için çeşitli faktörlerin etkisi gereklidir. Tümör gelişimi esnasında patolojik epitelyal mezenkimal geçiş (EMT) gözlenmektedir. EMT sürecinde epitel dokudaki hücreler özelliklerini kaybederek mezenkimal hücre özellikleri kazanmaktadır. Bu süreçte; E-kaderin, N-kaderin, klaudin gibi hücre adezyon molekülleri, Vimentin, TWİST, ZEB gibi EMT-TF (transkripsiyon faktörleri)’leri rol oynamaktadır. Literatür çalışmalarına bakıldığında bitki hormonu olan absisik asitin (ABA) hücre adezyonuna ve EMT sürecine etkisine dair çalışmalar oldukça azdır. Bu çalışmada PC3 hücrelerinde ABA’nın hücre adezyonundaki ve EMT sürecindeki etkileri araştırılmıştır. Bu kapsamda MTT ile hücre canlılık oranları, koloni formasyon deneyi ile hücrelerin koloni oluşturabilme yetenekleri, immünofloresans görüntüleme ile hücre içindeki proteinlerin düzeyleri ile lokalizasyonları ve western blot yöntemi ile hedef protein seviyelerinin tespiti sağlanmıştır. Çalışma verilerinde ABA’nın EMT sürecinde etkili ve yüksek seviyede ifade edilen Vimentin, -katenin gibi proteinlerin ifadesini azalttığı ve ZO1 gibi proteinlerin seviyelerinin arttığı gözlenmiştir. Bu durum tümör hücrelerinin epitel özellikler kazanmaya başladığını ve metastazın azaldığını göstermektedir. Sonuç olarak ABA’nın hücre adezyon molekülleri ve EMT sürecine dair etkilerine dair daha fazla çalışma yapılarak gelecekte yeni terapötik ajanların geliştirilmesinde önemli bir rol oynayacağı düşünülmektedir.Prostate cancer is a type of cancer that is quite common in men worldwide and has a low survival rate. These cancer cells, which develop in prostate gland, proliferate quite aggressively and have a high metastatic ability. The effect of various factors is necessary for tumor cells to metastasize and spread to other tissues. Pathological EMT is observed in tumor development process. During EMT, cells in the epithelial tissue lose their characteristics and gain mesenchymal cell characteristics. In this process; Cell adhesion molecules such as E-cadherin, N-cadherin, claudin, and EMT-TFs such as Vimentin, TWIST, ZEB play an important role. In the literature, studies on the effect of the plant hormone abscisic acid (ABA) on cell adhesion and EMT process are quite few. In this study, the effects of ABA on cell adhesion and EMT process in PC3 cells were investigated. In this context, cell viabilityrates were determined with MTT, the ability of cells to form colonies was determined with the colony formation assay, the levels and localization of proteins within the cell were determined with immunofluorescence imaging and target protein levels were determined with western blot method. In this thesis, it was observed that ABA reduced the expression of proteins such as Vimentin, and -catenin, which are effective and expressed at high levels in EMT process and increased the levels of proteins such as ZO1. This situation shows that tumor cells may have begun to acquire epithelial properties and metastasis may have decreased. As a result, it is thought that further studies on the effects of ABA on cell adhesion molecules and EMT process will play an important role in the development of new therapeutic agents in the future
The SPICE modeling of a radiation sensor based on a mosfet with a dielectric hfo2/sio2 double-layer
No full textWe report on a procedure for extracting the SPICE model parameters of a RADFET sensor with a dielectric HfO2/SiO2 double-layer. RADFETs, traditionally fabricated as PMOS transistors with SiO2, are enhanced by incorporating high-k dielectric materials such as HfO2 to reduce oxide thickness in modern radiation sensors. The fabrication steps of the sensor are outlined, and model parameters, including the threshold voltage and transconductance, are extracted based on experimental data. Experimental setups for measuring electrical characteristics and irradiation are described, and a method for determining model parameters dependent on the accumulated dose is provided. A SPICE model card is proposed, including parameters for two dielectric thicknesses: (30/10) nm and (40/5) nm. The sensitivities of the sensors are 1.685 mV/Gy and 0.78 mV/Gy, respectively. The model is calibrated for doses up to 20 Gy, and good agreement between experimental and simulation results validates the proposed model.North Atlantic Treaty Organization
G5974North Atlantic Treaty OrganizationMinistarstvo Prosvete, Nauke i Tehnološkog Razvoja
451-03-65/2024-03/200102, 451-03-66/2024-03/200026Ministarstvo Prosvete, Nauke i Tehnološkog Razvoj
Attitudes toward the military: Need for recognition and national and political identifications
No full textThis paper reports on a quantitative study that examined the relationship between need for recognition and militaristic attitudes, and tested the mediating roles of identification with Turkish society and left/right-wing political ideology in this relationship. The sample included 436 (297 women and 139 men) Turkish university students (living in T & uuml;rkiye) aged between 18 and 36 years (M = 22.18, SD = 2.68). Results indicated that after controlling demographic variables (age, gender, and military affiliation), Turkish identification and political orientation significantly mediated the relationships of need for recognition with attitudes toward value of the military, militaristic system, compulsory military service, and masculine structure of military. Accordingly, the need for recognition was positively related to identification with Turkish society, while it was negatively related to identification with right-wing political ideology. Besides, people -who identified more with Turkish society and right-wing political ideology- reported stronger militaristic attitudes. In addition to the well-known relationships of national identification and right-wing political ideology with militaristic attitudes, our study sheds light on the processes preceding these known associations by adding the variable of need for recognition to this equation. These results point to theoretical and practical implications in the process of making sense of the variables associated with militaristic attitudes
The effect of frailty on balance, fear of falling, and dual-task performance in individuals with type 2 DM
Get PDFThe aim of this study was to compare balance, fear of falling, and dual-task performance in frail, pre-frail, and non-frail individuals with type 2 DM. The study included 110 voluntary individuals diagnosed with type 2 DM. Individuals with type 2 DM were divided into three groups according to the FRAIL Scale: frail (n = 26), pre-frail (n = 52), and non-frail (n = 32). The FRAIL Scale evaluated individuals’ frailty levels, Timed Up and Go Test evaluated dual-task performance (cognitive and motor), and Tinetti Balance and Gait Scale evaluated balance and risk of falls. Considering the Fall Efficacy Scale, Tinetti Balance and Gait Scale, TUGstandard (sec), TUGcognitive (sec), and TUGmotor (sec) results of frail, pre-frail, and non-frail individuals with type 2 DM, a statistically significant difference was found between the groups (p < 0.05). This difference originated from the frail group. Considering the increase in old age and chronic syndromes, such as DM, it brings about, it was concluded that the early evaluation of older adults for frailty and balance was essential and that individually planned intervention could improve prognosis, reduce falls that might occur due to a loss of balance and muscle strength, and enhance the quality of life in older adults