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Dynamic analysis of restrained short-fiber-reinforced and functionally graded nanobeams via stress-driven model
Get PDFIn this work, the lateral dynamic response of two types of restrained composite nanobeams is studied. One of these nanobeams consists of a functionally graded composite material, while the other is in the form of a matrix reinforced with short fibers. These composite nanobeams rest on deformable springs. In the dynamic problem, stress-driven theory is considered to highlight the small-scale effect. To provide the general solution for calculating the free lateral vibration frequencies of the composite nanobeams, Fourier sine series and Stokes' transform are utilized. The effects of damping on the dynamic behavior of nanobeams are also demonstrated using the Kelvin-Voigt viscoelastic model. After the mathematical steps, a general eigenvalue problem is derived that includes small-scale, elastic spring, and damping effects. The validation of the model and the effects of various parameters on the free lateral vibration frequencies of the restrained composite nanobeams are presented in tables and graphs
Low sirtuin-1 levels are linked to erythropoietin resistance in hemodialysis patients
Get PDFIntroduction: Erythropoiesis-stimulating agents (ESAs) are widely used to manage anemia in chronic hemodialysis patients. However, some individuals exhibit ESA resistance, and its underlying mechanisms remain unclear. Sirtuin-1 (SIRT1), a key regulator of hypoxia and iron metabolism, may influence ESA responsiveness. This study investigates the relationship between SIRT1 levels and ESA resistance. Methods: This cross-sectional study analyzed 391 chronic hemodialysis patients, including ESA-treated and untreated individuals. ESA responsiveness was assessed using the Erythropoietin Resistance Index (ERI), calculated as weekly body-weight-adjusted ESA dose divided by hemoglobin concentration. Associations between SIRT1 levels, ERI quartiles, and ESA responsiveness were examined. Results: A total of 385 patients were included in the analysis. Serum SIRT1 levels were significantly lower in ESA-treated patients than in untreated individuals. A negative correlation was found between SIRT1 levels and ERI (r = -0.179, p = 50th percentile) had significantly lower SIRT1 levels. Logistic regression indicated that only SIRT1 was significantly associated with high ERI (B = -0.035, p = 0.018). Conclusion: This study examined the relationship between SIRT1 levels and ESA hyporesponsiveness in patients undergoing hemodialysis. The findings demonstrate that lower SIRT1 levels are associated with higher ERI values, suggesting a potential role for SIRT1 in modulating ESA resistance
The recurrence outcome with respect to treatment choices in idiopathic granulomatous mastitis: A retrospective cohort study with 10-year single-center experience
Get PDFBackground: This study aimed to investigate the recurrence outcome with respect to treatment choices in patients with idiopathic granulomatous mastitis (IGM). Methods: A total of 175 female patients (mean +/- SD age: 36.3 +/- 8.9 years) with histopathologically confirmed IGM were included in this retrospective cohort study. Data on patient age, presenting symptoms, treatment protocols (medical and/or surgery), the recurrence rate, recurrence-free survival (RFS) and progression-free survival (PFS) were recorded. RFS time (month) and PFS and time (month) were compared across medical treatment subgroups (antibiotic, steroid, steroid-sparing immunosuppressant). Results: The treatment protocols involved surgery plus medical treatment in 82(46.9 %) patients, medical treatment alone in 82(46.9) and surgery alone in 11(6.2 %) patients. The medical treatment included the immunosuppressive therapy (42.1 %), antibiotic therapy (29.3 %) and steroid therapy (28.7 %). Within a median 36 months of follow-up, recurrence was noted in 64(39.5 %) patients and was significantly more common in the surgery plus medical treatment group than in the medical treatment alone group (53.7 % vs. 25.0 %, p < 0.001). Overall, median (95 % CI) RFS time and PFS time were 29(21.9-36.1) months and 12(5.8-18.2) months, respectively. No significant difference was noted between medical treatment subgroups in terms of RFS time (log-rank p value: 0.176) and PFS time (log-rank p value: 0.421). Nonetheless, immunosuppressive therapy showed a non-significant tendency for longer RFS (vs. steroid therapy) and longer PFS (vs. both antibiotic and steroid therapy). Conclusions: In conclusion, this retrospective cohort study in patients with IGM revealed the association of systemic therapy, particularly the steroid-sparing immunosuppressive treatment, with favorable long-term RFS and PFS outcome. (c) 2025 Asian Surgical Association and Taiwan Society of Coloproctology. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/ by-nc-nd/4.0/)
An empirical study on social media user motivations
Get PDFTeknoloji, tarihsel süreç boyunca bireylerin toplumsal ilişkilerini kurmalarında, anlam üretiminde ve bilgi aktarımında belirleyici bir rol üstlenmiştir. Özellikle dijitalleşmeyle birlikte iletişim alışkanlıklarında köklü dönüşümler yaşanmıştır. Geleneksel ve tek yönlü medya yapısından, etkileşim temelli ve kullanıcı odaklı dijital platformlara geçiş söz konusu olmuştur. İnternetin yaygınlaşması ve Web 2.0 teknolojilerinin gelişimi, bireyleri yalnızca içerik tüketicisi olmaktan çıkararak aynı zamanda içerik üreticisi ve dağıtıcısı haline getirmiştir. Bu dönüşümün somut yansımaları sosyal medya platformlarında açıkça gözlemlenmektedir. Sosyal medya, yalnızca dijital iletişimin temel bir aracı olmakla kalmayıp, bireylerin çok katmanlı sosyal, psikolojik ve bilişsel ihtiyaçlarına yanıt veren dinamik bir mecra olarak da öne çıkmaktadır. Sosyal medya ilişki kurmanın ötesinde; ilişki kurma ve sosyalleşme, bilgilenme ve kişisel gelişim, kendini ifade etme, eğlence ve vakit geçirme, fırsat arayışları ve sosyal etki gibi çeşitli amaçlarla kullanılmaktadır. Farklı sosyal medya platformlarının sunduğu içerik formatları ve etkileşim olanakları, kullanıcıların tercihlerini etkileyen temel unsurlar arasında yer almaktadır. Bu durum, sosyal medya kullanım motivasyonlarının çok boyutlu bir yaklaşımla ele alınmasını gerekli kılmaktadır. Bu çalışma, bireylerin sosyal medya kullanıcı motivasyonlarını analiz ederek söz konusu motivasyonların demografik değişkenlerle ilişkisini incelemeyi amaçlamaktadır. Çalışmada belirlenen demografik değişkenler bağlamında sosyal medya kullanıcı motivasyonları hakkında karşılaştırmalar yapılmış; bu kapsamda bağımsız örneklem t-testi uygulanarak anlamlı farklılıklara ilişkin sonuçlara ulaşılmıştır. Elde edilen bulgular doğrultusunda, sosyal medya kullanıcı motivasyonlarına dair kapsamlı bir çerçeve sunulması ve gelecek çalışmalara katkı sağlanması hedeflenmektedir.Communication has played a decisive role throughout history in establishing social relationships, creating meaning, and transferring information among individuals. Especially with digitalization, profound transformations have occurred in communication habits. There has been a shift from traditional, one-way media structures to interactive and user-centered digital platforms. The widespread adoption of the internet and the development of Web 2.0 technologies have transformed individuals from mere content consumers into active content creators and distributors. This transformation is clearly reflected in social media platforms. Social media not only serves as a fundamental tool of digital communication but also emerges as a dynamic medium that responds to individuals' multifaceted social, psychological, and cognitive needs. Beyond establishing connections, it is used for various purposes such as socializing, information seeking, personal development, self-expression, entertainment, leisure, opportunity seeking, and social influence. The content formats and interactive features offered by different social media platforms are key factors affecting user preferences. This situation necessitates a multidimensional approach to understanding social media usage motivations. This study aims to analyze individuals' social media usage motivations and examine their relationships with demographic variables. Based on the data obtained, comparisons were made according to specified demographic variables, and independent samples ttests were conducted to identify significant differences. The findings provide a comprehensive framework for understanding social media usage motivations and aim to contribute to future research in this field
Investigation of fresh state, mechanical and durability properties of cementitious systems reinforced with different plastic waste fiber materials: An experimental study
No full textUtilization of fibers obtained from waste plastics in mortar mixtures was investigated in this study. For this purpose, fibers obtained from polyethylene terephthalate, high density polyethylene and polypropylene type plastic waste were used in mortar mixtures at the rate of 0.5%, 1% and 1.5% by volume. 10 mortar mixtures were produced. Flowability, unit weight, compressive strength and flexural strength of the produced mixtures were investigated. Also, water absorption and porosity ratio, capillary water absorption, sulfate resistance and abrasion resistance of some selected mixtures were investigated. Regardless of the waste plastic fiber type a decrease of 1.8% to 8% in flow performance of the mixture was detected. This effect became more pronounced for all waste fibers as the fiber content increased. Also, this negative effect is more dominant in polypropylene fiber mixtures. It was determined that the mixtures with the highest compressive strength value were the mixtures containing high density polyethylene fiber, and an increase of 3.8% was achieved compared to the control mixture. The transport properties of mortar mixtures were negatively affected by the use of fiber. Mixtures containing high density polyethylene fiber are more effective on mechanical performance of systems and more resistant to abrasion compared to other fibers.Turkish Academy of Science
Diagnostic accuracy and predictive value of the QuantiFERON-TB gold plus assay for tuberculosis in immunocompromised individuals: A prospective TBnet study
No full textBackground In low tuberculosis (TB)-endemic countries, tuberculosis preventive therapy (TPT) is recommended for immunocompromised individuals with a positive immunodiagnostic test. This study aimed to assess the performance of the QuantiFERON-TB Gold Plus (QFT+) assay and predictive power for future tuberculosis in immunocompromised individuals. Methods In this prospective observational study, immunocompromised adults >= 18 years of age including people living with HIV (PLHIV), chronic renal failure, rheumatoid arthritis, solid-organ transplantation or stem-cell transplantation, and immunocompetent adults with and without TB-disease were recruited at 21 sites in 11 European countries and tested with the QFT+ assay. Individuals without TB-disease were followed up for the development of tuberculosis. TB incidence rates (IR) were calculated, stratified by QFT+ results and acceptance of TPT. This study is registered with Clinicaltrials.gov, NCT02639936. Findings A total of 2663 individuals (1115 female, 1548 male) were enrolled from 03/11/2015 to 29/03/2019. Persons without tuberculosis were followed up for at least two years. Among 1758 immunocompromised individuals without active tuberculosis, 13.6% had positive QFT+ results. Sensitivity and specificity for TB-disease were 70.0% (52.1-83.3%) and 91.4% (89.6-92.9%), respectively, in immunocompromised, and 81.4% (76.6-85.3%) and 96.0% (92.5-97.9%), respectively, in immunocompetent individuals. During 2457 cumulative years of follow-up among 932 individuals with chronic renal failure, rheumatoid arthritis, solid-organ transplantation or stem-cell transplantation, including 83 persons with a positive QFT+ test without TPT, no-one developed active tuberculosis. In contrast, among 642 PLHIV without TPT, one with an indeterminate QFT+ and 3/30 individuals with a positive QFT+ developed active tuberculosis; all had detectable HIV-replication and low CD4 T-cell counts (incidence 4.1 (95% CI (1.3-12.4) per 100 person-years). No individuals receiving TPT developed active tuberculosis during 269 years of follow-up. Interpretation In immunocompromised individuals in low TB-endemic countries, the 2-year-risk for active tuberculosis was highest among PLHIV with detectable HIV-replication and low CD4-counts. In this study, the QFT+ assay did not strongly predict progression to active tuberculosis, which emphasises the need to incorporate additional risk factors. Funding None. Copyright (c) 2025 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
Exploring knowledge production and policy shifts in global higher education
No full textHigher education is undergoing significant transformation in response to global pressures such as policy shifts, internationalization, and changing governance models. As institutions adapt to these trends, they must find ways to balance academic excellence with equity, sustainability, and responsiveness to societal needs. The production and dissemination of knowledge play a central role in shaping how universities contribute to global challenges. These shifts demand reimagined curricula, cross-border collaboration, and inclusive leadership to ensure higher education remains a driver of progress and innovation. Understanding these dynamics is essential for aligning institutional practices with the broader goals of global development and social impact. Exploring Knowledge Production and Policy Shifts in Global Higher Education examines the essential dimensions shaping higher education amidst current global trends in policy, governance, and internationalization, with a focus on how knowledge production contributes to these dynamics and influences the evolving role of higher education. It provides a comprehensive overview of how institutions can respond to global challenges. Covering topics such as curriculum reform, knowledge development, and sustainable development, this book is an excellent resource for scholars, educators, policymakers, institutional leaders, and more
Mosques constructive by Gazi Süleyman Pasha
Get PDFGazi Süleyman Paşa, Osmanlı Devleti’nin erken dönem fetih hareketlerinde üstlendiği idari ve askeri rollerinin yanı sıra önemli imar faaliyetleri gerçekleştirmiştir. Bu araştırmada Süleyman Paşa’nın baniliğini üstlendiği camiler, Sanat Tarihi yöntemleri ışığında plan, malzeme, teknik özellikler, süsleme unsurları ve tarihî süreçte geçirdikleri restorasyonlar açısından incelenmiştir. Ele alınan camiler günümüz Marmara Bölgesi, Trakya ve Balkanlar coğrafyasını kapsamaktadır. Yapılar, literatür taraması ve saha araştırması yöntemleri ile analiz edilmiştir. Araştırmanın ilk aşamasında arşiv belgeleri, vakfiyeler, evkaf ve tahrir defterleri, seyahatnameler ve kronikler gibi birincil kaynaklarla dijital kütüphane ve matbu eserlerden oluşan ikincil kaynaklar kullanılarak kapsamlı bir literatür taraması yapılmıştır. İkinci aşamada gerçekleştirilen saha çalışmasında ise eserlerin mevcut durumları yerinde incelenerek fotoğraflama, ölçüm ve belgeleme çalışmaları yürütülmüştür. Bu çalışmayla, Süleyman Paşa’ya atfedilen eserler üç kategoriye ayrılmıştır: günümüze ulaşan, ulaşılamayan ve banilikleri tartışmalı olanlar. Yapıların tarihî kimliği, mimari gelişimi ve geçirdikleri dönüşümler değerlendirilmiş, böylelikle eserlerin dönemin mimari anlayışı içindeki özgünlüğü tespit edilmeye çalışılmıştır. Araştırma kapsamında toplam 20 cami değerlendirilmiştir. Elde edilen bulgular kronolojik ve bütüncül bir yaklaşımla analiz edilerek Süleyman Paşa’nın imar faaliyetlerinin Osmanlı şehirciliğinin oluşumundaki yeri ve önemi ortaya konmuştur. Araştırma, ilgili alanlardaki gelecekteki çalışmalara temel teşkil edecek veri ve belgeleri içermektedir.Gazi Süleyman Pasha played an important role in the early conquests of the Ottoman Empire, both administratively and militarily, and also carried out significant construction projects. In this study, the mosques built under Süleyman Pasha's patronage were examined in terms of their plans, materials, technical characteristics, decorative elements, and restorations undergone throughout history, using art history methods. The mosques examined cover the geography of today's Marmara Region, Thrace, and the Balkans. The structures were analysed using literature review and field research methods. In the first phase of the research, a comprehensive literature review was conducted using primary sources such as archival documents, waqf deeds, waqf and tahrir registers, travelogues, and chronicles, as well as secondary sources consisting of digital libraries and printed works. In the second phase, fieldwork was conducted to examine the current state of the structures, including photography, measurement, and documentation. With this study, the works attributed to Süleyman Pasha were divided into three categories: those that have survived to the present day, those that cannot be reached, and those whose authorship is controversial. The historical identity of the structures, their architectural development, and the transformations they underwent were evaluated, thus attempting to determine the originality of the works within the architectural understanding of the period. A total of 20 mosques were evaluated within the scope of the research. The findings were analysed using a chronological and holistic approach, revealing the place and importance of Süleyman Pasha's urban development activities in the formation of Ottoman urbanism. The research contains data and documents that will serve as a basis for future studies in related fields
Evaluation of the effect of using different types of clinker grinding aids on grinding performance by numerical analysis
Get PDFTo develop more environmentally friendly and sustainable cementitious systems, the use of grinding aids (GAs) during the clinker grinding process has increasingly gained attention. Although the mechanisms of the action of grinding aids (GAs) are known, the selection of an effective grinding aid (GA) can be difficult due to the complexity of appropriate selection criteria. For this reason, it is important to model the effect of GA properties on grinding performance. In this study, seven different types of GAs were used in four different dosages, and time-dependent grinding was performed. The Blaine fineness values of cements were compared after each grinding process. In addition, the modeling of these parameters using machine learning and ensemble learning methods was discussed. The Synthetic Minority Over-sampling Technique (Smote) was used to generate artificial data and increase the number of data for the grinding efficiency experiment. The data were modeled using methods such as Artificial Neural Networks (ANNs), Attentive Interpretable Tabular Learning (TabNet), Random Forests (RFs), and the XGBoost Regressor (XGBoost), and the ranking of the parameters affecting the Blaine properties was determined using the XGBoost method. The XGBoost method achieved the best results in the MAE, RMSE, and LogCosh metrics with values of 21.0384, 33.7379, and 15.4846, respectively, in the experimental modeling studies with augmented data. This study contributes to a better understanding of the relationship between GA selection and milling process performance