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Notch1 and Major Vault Proteins Modulate Temozolomide Resistance in Glioblastoma
Get PDFThe development of resistance to chemotherapy in the case of aggressive glioblastoma multiforme (GBM) presents a significant treatment challenge. Dysregulation of the Notch signalling pathway promotes tumour proliferation in GBM cells. This study was that targeting the Notch signalling pathway could be a potential therapeutic approach for GBM. Initially, temozolomide-(TMZ)-resistant GBM cells were generated, and the effect of Notch1 on the expression of multiple resistance proteins within these cells was investigated. Subsequently, the expression of Notch-1 in GBM cells was reduced using siRNA. Results revealed a significant reduction in TMZ sensitivity in TMZ-resistant GBM cells, accompanied by a substantial increase in the expression of major vault protein-(MVP), O6-methylguanine-DNA-methyltransferase-(MGMT), and ATP-binding-cassette transporter-G2-(ABCG2). Furthermore, TMZ-resistant U87-R and U251-R cells exhibited higher proliferation rates compared to their parental control cells (U87 and U251). Additionally, we observed that downregulating Notch-1 signalling inhibited the proliferation of TMZ-resistant U87-R and U251-R cells. This downregulation led to the inactivation of MGMT, ABCG2, and MVP. Importantly, it increased chemosensitivity to TMZ, particularly by downregulating MVP expression. Consequently, Notch1 could serve as a potential therapeutic target for GBM cells and may be effective in preventing TMZ resistance by targeting MVP, as well as MGMT and ABCG2 in GBM cells
Investigation of electric vehicle charging station installation and management system in a public institution in Mardin province
Get PDFSınırsız olmayan fosil yakıtlar gün geçtikçe azalmakta, yerini yenilenebilir enerji kaynaklarına bırakmaya başlamıştır. Ulaşım sektöründe fosil yakıtla çalışan araçlar karbon emisyonuna neden olduklarından çevreyi kirletmekte ve yerlerini doğa dostu elektrikli araçlara bırakmaktadır. Gelişmiş ülkeler özellikle Amerika Birleşik Devletleri ve Çin elektrikli araçlar konusunda rekabet yarışı içerisindedirler. Türkiye ve diğer dünya ülkelerinde de elektrikli araçlar üretilmeye başlanmış ve elektrikli araçlara olan yönelim hızla artmıştır. Ancak elektrikli araç kullanıcılarının elektrikli araç şarj istasyonlarına ulaşım endişesi bulunmaktadır. Bundan dolayı elektrikli araç şarj istasyon sayısı ve ulaşılabilirliği önem arz etmektedir. Günümüzde hızlı elektrikli araç şarj istasyonlarının güçleri 400 kW'ın üstündedir. Bu yüksek güçlü şarj istasyonları ve bu istasyonlara bağlanarak şarj olan elektrikli araçlar şebeke üzerinde aşırı bir yükün oluşmasına neden olabilecektir. Bu çalışmada Mardin ili merkez ilçesinde kamu kurumlarının bulunduğu Valilik yerleşkesinde bulunan ve sadece kamu personelinin araçlarının park edildiği, enerjisini valilik yerleşkesini besleyen özel trafodan alan valilik otoparkına senaryonlar halinde, 22 kW, 100 kW ve 180 kw'lık elektrikli şarj istasyonlarına batarya doluluk oranı %20 olan ve %100' e kadar şarj olacak elektrikli araçlar bağlanarak Matlab Simulink programı ile trafodan çekilen yük ve akım miktarları ölçülmüştür. Gerilim düşümü hesaplanmıştır. Trafonun maksimum %80 doluluk oranına göre sonuçlar analiz edilmiştir. Ayrıca trafonun %80 doluluk oranını aşmayacak şekilde valilik otoparkına kurulabilecek elektrikli araç şarj istasyon sayısı ve tipleri belirlenmiştir. Trafo değeri iki katına çıkarıldığında sonuçlar karşılaştırılmış, elde edilen veriler ayrıntılı olarak analiz edilmiştir.Unlimited fossil fuels are decreasing day by day and have begun to be replaced by renewable energy sources. In the transportation sector, fossil fuel-powered vehicles pollute the environment as they cause carbon emissions and are being replaced by environmentally friendly electric vehicles. Developed countries, especially the United States and China, are in a competitive race for electric vehicles. Electric vehicles have also begun to be produced in Turkey and other countries around the world, and the trend towards electric vehicles has increased rapidly. However, electric vehicle users have concerns about access to electric vehicle charging stations. Therefore, the number of electric vehicle charging stations and their accessibility are important. Today, the power of fast electric vehicle charging stations is over 400 kW. These high-power charging stations and electric vehicles that are charged by connecting to these stations can cause an excessive load on the network. In this study, in the governorate campus where public institutions are located in the central district of Mardin province, electric vehicles with a battery charge rate of 20% and that will charge up to 100% were connected to the governorate parking lot, which is located in the governorate campus where only public personnel vehicles are parked and receives its energy from the special transformer that feeds the governorate campus, in scenarios, and the load and current amounts drawn from the transformer were measured with the Matlab Simulink program. The voltage drop was calculated. The results were analyzed according to the maximum 80% charge rate of the transformer. In addition, the number and types of electric vehicle charging stations that can be installed in the governorate parking lot were determined so that the transformer would not exceed 80% charge rate. The results were compared when the transformer value was doubled, and the obtained data were analyzed in detail
Prevalence of adolescent pregnancy and evaluation of pregnancy outcomes: a retrospective study
Get PDFIntroductionAccording to the World Health Organization, adolescent pregnancy is defined as pregnancies of women aged 19 and below. The study aims to analyze the rates of adolescent pregnancies and maternal and fetal outcomes among births within the hospital and compare them with adult pregnancies.MethodsThe study is conducted retrospectively in one of Turkey's socio-economically underdeveloped provinces. The study comprises 16,985 women: 1719 adolescents and 15,266 adults who gave birth in the hospital between January 1, 2020, and December 31, 2023. All data were recorded in the SPSS 28.0 program, and the Kolmogorov-Smirnov test, Chi-Square test, ANOVA, and Independent Simple T-test were applied to analyze the data.ResultsIn the study, the adolescent pregnancy rate is found to be 10,1%. The mean maternal age (p = 0.000), gravida (p = 0.000), parity (p = 0.000), and number of abortions (p = 0.002) are significantly higher in the adult group. No difference is found between the groups in terms of gestational age (p = 0.067). Newborn birth weight was significantly higher in the adult group (p = 0.000). Cesarean section rates are higher in the adult group (p = 0.001). No difference is found in terms of stillbirth rates. No difference is found between the groups in terms of pre-eclampsia (p = 0.792). No difference is found between the groups in terms of preterm birth (p = 0.664).ConclusionIn conclusion, it came out that, according to the results of the study, the rates of premature birth, pre-eclampsia, and stillbirth in adolescents and the first and fifth-minute Apgar scores are similar to adults. However, newborn birth weights are lower in the babies of adolescent pregnant women. In addition, cesarean section rates are higher in the adult group.Scientific and Technological Research Council of Turkiye (TUBITAK)Open access funding provided by the Scientific and Technological Research Council of Turkiye (TUBITAK). No financial support was received from any institution or organization during the prepara-tion of this stud
A Hybrid Model for Enhancing Risk Management and Operational Performance of AEC (Architectural, Engineering, and Construction) Consultants: An Integrated Partial Least Squares-Artificial Neural Network (PLS-ANN) Approach
Get PDFThe operational effectiveness of Architectural, Engineering, and Construction (AEC) consultants, whose services have a substantial impact on project execution and results, depends on effective risk management. Using 336 survey responses from professionals in the construction industry, such as consultants, contractors, and employers working on a range of infrastructure and building projects, this study validates a hybrid Partial Least Squares Structural Equation Modeling-Artificial Neural Network (-ANN) approach. In order to ensure both causal analysis and predictive insights for AEC consultant performance assessment, this study combines PLS-SEM and ANN to develop an integrated performance evaluation framework. While ANN ordered their relative relevance in a non-linear predictive model, the PLS-SEM analysis found that the two most important predictors of consultant performance were communication and relationship management (G03) and document and record management (G06). The hybrid approach is a more efficient and data-driven tool for evaluating AEC consultants than traditional regression models since it accurately captures both causal links and predictive performance. These results contribute to a robust and sustainable framework for performance evaluation in the AEC sector by offering practical insights into risk reduction and operational improvement
Carvacrol: A Protective Agent Against Cadmium Nitrate Toxicity in Allium cepa L.
Get PDFMonoterpenes are isoprene derivatives that contain conjugated double bonds and are synthesized in many plant families. In this study, the aim was to measure the protective effect of carvacrol, one of these monoterpenes, against cadmium nitrate-induced oxidative stress using parameters such as morphologic, cytogenetic, and antioxidant activity via the Allium cepa L. model. The control group was treated with distilled water, while the treatment groups were treated with low (25 ppm) and high (100 ppm) doses of carvacrol, cadmium nitrate (80 ppm), carvacrol (25 ppm) + cadmium nitrate (80 ppm), and carvacrol (100 ppm) + cadmium nitrate (80 ppm) for 96 h. Improvements were observed in the adverse effects induced by cadmium nitrate with increasing doses of carvacrol. When the MI values of carvacrol at concentrations of 25 and 100 ppm were compared with the negative control, a statistically significant increase was observed. Furthermore, the high dose (100 ppm) of carvacrol co-administered with cadmium nitrate caused a decrease in the number of abnormalities induced by cadmium nitrate. It was observed that the activities of superoxide dismutase and catalase increased in the cadmium nitrate. However, in the samples where cadmium nitrate and carvacrol were co-administered, the activities of superoxide dismutase and catalase decreased depending on the concentration. As a result, it was determined that none of the concentrations of carvacrol had cytotoxic and genotoxic effects, and carvacrol at a concentration of 100 ppm exhibited a protective effect against the toxicity induced by cadmium nitrate
Preoccupation with Social Media and Employee Performance
Get PDFSocial media usage patterns and norms vary significantly across industries and cultures. This study investigates how cognitive preoccupation with social media affects employee performance. More specifically, it focuses on the role the regulatory mechanisms of task-oriented and relationship-oriented uses of social media play in the relationship between cognitive preoccupation and employees' performance in T & uuml;rkiye. Survey questionnaires were administered to 331 healthcare professionals in six private and public hospitals in Istanbul. A significant negative relationship between cognitive preoccupation and employee performance was observed. This relationship was positively moderated by task-oriented and relationship-oriented social media use. The study makes social cognition theory more specific by applying it to the case of social media use while generalizing it to the healthcare industry in T & uuml;rkiye. Moreover, it refines social capital theory by providing insights into mitigating the negative consequences of excessive use of social media on employee performance. The development of a cross-cultural theory of the use of social media would require comparable studies that should be conducted in other industries and cultures
Mitigating Post-Subarachnoid Hemorrhage Complications: Anti-Inflammatory and Anti-Apoptotic Effects of Anakinra in an Experimental Study
Get PDFBackground: Subarachnoid hemorrhage (SAH) is a severe neurological condition with high mortality and morbidity rates, often exacerbated by secondary complications such as inflammation, cerebral vasospasm, and apoptosis. Proinflammatory cytokines, including interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6), play critical roles in these pathological processes. Anakinra, an IL-1 receptor antagonist, has demonstrated significant anti-inflammatory effects in various disease models. This study aimed to evaluate the efficacy of anakinra in mitigating inflammation, vasospasm, and apoptosis in an experimental rat model of SAH. Methods: Thirty-two male Sprague Dawley rats were divided into four groups: Control (healthy), SAH (no treatment), Saline (0.2 mL saline subcutaneously), and Anakinra (50 mg/kg subcutaneously, twice daily). Proinflammatory markers (CRP, TNF-alpha, IL-1, IL-6, and fibrinogen) were measured in serum and cerebrospinal fluid (CSF) at 3, 7, and 10 days post-SAH. Basilar artery diameter was evaluated histopathologically, and Caspase-3 expression was assessed immunohistochemically to determine apoptotic activity. Results: SAH significantly increased levels of CRP, TNF-alpha, IL-1, IL-6, and fibrinogen in both serum and CSF, reduced basilar artery diameter, and elevated Caspase-3 expression compared to the Control group. Saline treatment provided limited improvements, with inflammatory markers and histopathological parameters remaining elevated. Anakinra treatment significantly reduced inflammatory markers, restored basilar artery diameter, and lowered Caspase-3 expression, highlighting its efficacy in mitigating inflammation, vasospasm, and apoptosis. Conclusions: Anakinra effectively suppresses inflammation, alleviates cerebral vasospasm, and inhibits apoptosis in an experimental model of SAH. These findings suggest its potential as a therapeutic agent for managing SAH and its complications. Further research is needed to explore its clinical applicability and long-term effects
Modern Arap Edebiyatında Engelli Bireylerin Temsili: İbrahim Nasrallah ve Kilimanjaro’nun Ruhları Romanı Örneği
Get PDFBu çalışma, İbrâhim Nasrallâh’ın Kilimanjaro’nun Ruhları adlı romanı üzerinden engelliliğin Modern Arap romanında temsiline odaklanmaktadır. Engellilik sosyal dışlanma, ayrımcılık ve baskılarla şekillenen kültürel bir tanımlamadır. Edebiyat, engelli bireylerin toplumsal rollerini ve bu bireylerin iç dünyalarını anlamamıza yardımcı olmak için önemli bir araçtır. Batı edebiyatında engellilik genellikle bir eksiklik olarak resmedilse de Arap edebiyatı bu bireylerin yaşadığı zorlukları ve başarılarını ayrıntılı bir şekilde ele almaktadır. Nasrallâh, bu eserinde bizzat yaşadığı bir tecrübenin tarihi kaydını tutmaktadır. Bu roman, Tanzanya’da bulunan ve dünyanın dördüncü en yüksek zirvesi olan Kilimanjaro Dağı’nda dokuz gün sürecek bir tırmanış öyküsünü anlatmaktadır. Romanın gerçek kahramanları olan Yasmîn en-Neccâr ve Muʿtasım Ebû Keriş’in protez bacaklarla zirveye doğru attıkları her adım, aslında özgürlüğe doğru attıkları bir adımdır. Dış dünyada olduğu gibi insan ruhunda da zirveler vardır. Eserin üçüncü engelli karakteri Ğassân’a hayat veren Ahmed ed-Devâbşe’nin ulaşmak istediği zirve ise Yahudi yerleşimcilerin işgalinden evini kurtarmaktır. Yazarına 2016 yılında Katara Arap Roman Ödülü’nü kazandıran bu roman, engelliliğin bedensel olmaktan çok ruhsal bir durum olduğunu ortaya koyan güçlü örnekler sunmaktadır
Development of volatile corrosion inhibitor (VCI) with potential for use in packaging industry
Get PDFBu araştırmada, bor-amin kompleksi, karboksilik asit ve ester gruplarını içeren uçucu korozyon inhibitörü (VCI) karışımının, %3,5 NaCl çözeltisi içindeki St37 karbon çeliğinin korozyon davranışı üzerindeki etkisi değerlendirilmiştir. VCI'nin korozyona karşı ne kadar etkili koruma sağladığını belirlemek için elektrokimyasal empedans spektroskopisi (EIS) ve tafel polarizasyonu (TP) testleri gerçekleştirilmiştir. Ayrıca, inhibitörün etkinliğini doğrulamak için sanayide yaygın bir şekilde kullanılan TL-8135-0043 standardına uygun VCI testleri gerçekleştirilmiştir. Buna ek olarak, inhibitörün çelik yüzeyinde oluşturduğu koruyucu kaplamayı incelemek için taramalı elektron mikroskobu (SEM), enerji dağılımlı X-ışını spektroskopisi (EDAX) ve atomik kuvvet mikroskopu (AFM) kullanılmıştır. EIS bulguları, daha yüksek VCI konsantrasyonları ile ilişkili olarak korozyon direncinde belirgin bir artış olduğunu göstermiştir. Nyquist grafiklerinin analizi, VCI'nın %71,24 koruma sağladığını ortaya koydu. Karakterizasyon sonuçları, inhibitörün yüzeye yapışarak yük transferini engellediğini ve korozyon hızını azalttığını göstermiştir. TP testleri, VCI'nın anodik tip inhibitör olarak işlev gördüğünü ve esas olarak anodik çözünmeyi engellediğini ortaya koymuştur. VCI testi TL-8135-0043 standartlarına göre gerçekleştirilmiştir ve VCI ile emprenye edilmiş kağıtla kaplı metal numunelerde 30 güne kadar korozyon belirtisi görülmemiştir. SEM-EDAX ve AFM değerlendirmeleri, inhibitörün metal yüzeye yapıştığını ve koruyucu bir tabaka oluşturduğunu doğrulamıştır.In this study, the effect of a volatile corrosion inhibitor (VCI) mixture containing boron-amine complex, carboxylic acid, and ester groups on the corrosion behavior of St37 carbon steel in a 3.5% NaCl solution was evaluated. The efficacy of the VCI in providing corrosion protection was determined through the implementation of electrochemical impedance spectroscopy (EIS) and Tafel polarization (TP) tests. Furthermore, VCI tests that were compliant with the TL-8135-0043 standard, a prevalent industry standard, were performed to validate the effectiveness of the inhibitor. In addition, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDAX), and atomic force microscopy (AFM) were utilized to examine the protective coating formed by the inhibitor on the steel surface. The findings of the Electrochemical Impedance Spectroscopy (EIS) analysis indicated a substantial enhancement in corrosion resistance that was concomitant with elevated Vanadium-based Corrosion Inhibitors (VCI) concentrations. A thorough analysis of the Nyquist plots indicated that VCI offered 71.24% protection. The characterization results demonstrated that the inhibitor adheres to the surface, thereby impeding charge transfer and decreasing the corrosion rate. The results of the TP tests demonstrated that VCI functions as an anodic-type inhibitor, primarily inhibiting anodic dissolution. The VCI test was conducted in accordance with the standards delineated in TL-8135-0043, and no indications of corrosion were observed on metal samples covered with VCI-impregnated paper for a period of up to 30 days. The use of SEM-EDAX and AFM evaluations revealed that the inhibitor adheres to the metal surface, forming a protective layer
Effect of different cooling/lubrication regimes on machinability properties in the miling of Hastelloy X super alloy
Get PDFUzay ve havacılık sektörünün son yıllarda gösterdiği ciddi gelişmeler malzeme teknolojisinin de gelişmesine katkıda bulunmuştur. Malzeme teknolojisinin gelişmesine paralel olarak üstün özelliklere sahip süper alaşım malzemeler geliştirilmiştir. Süper alaşım adı verilen bu malzemelerin üstün özelliklerinin yanında, şekillendirilmesinde zorluklar yaşanabilmektedir. Yaşanan bu zorlukların üstesinden gelebilme adına araştırmacılar sürdürülebilir yöntemlerin geliştirilmesi için çalışmalarına hız vermiştir. Bu çalışmada uzay ve havacılık alanında kullanılan, Hastelloy X süper alaşım malzemesi sürdürülebilir soğutma/yağlama koşulları altında frezelenmiştir. Frezeleme deneyleri iki aşamada gerçekleştirilmiştir. Birinci aşamada nano akışkanların partikül boyutlarının işleme performansı üzerindeki etkilerinin incelenmesi amaçlanmıştır. Bu amaç doğrultusunda, kuru, minimum miktarda yağlama (MMY), 4 nm boyutlu Al2O3, 48 nm boyutlu Al2O3 ve 136 nm boyutlu Al2O3 nano akışkan soğutma/yağlama koşulları tercih edilmiştir. İkinci aşamada ise kuru, MMY, Al2O3 ilaveli nano akışkan, vorteks, CO2, MMY+vorteks, nano akışkan+vorteks, CO2+MMY, CO2+nano akışkan soğutma/yağlama koşullarının işleme performansı üzerine etkilerinin incelenmesi amaçlanmıştır. Soğutma/yağlama koşullarının etkilerini inceleme adına kesme hızı, ilerleme ve kesme derinliği parametreleri, sırasıyla 50 m/dak, 0,10 mm/dev ve 0,5 mm sabit alınmıştır. Performans kriteri olarak olarak yüzey pürüzlülüğü Ra, kesme sıcaklığı ve güç tüketimi değeri belirlenmiştir. Birinci aşama deneylerden elde edilen sonuçlara göre, diğer koşullara kıyasla 4 nm boyutlu Al2O3 nano akışkanı daha üstün performans sergilemiştir. 4 nm boyutlu Al2O3 nano akışkan koşulu kuru koşula göre, yüzey pürüzlülüğü, kesme sıcaklığı ve güç tüketim sonuçlarında sırasıyla %37,43, %36,02 ve %8,33 oranında düşüş göstermiştir. İkinci aşama deneylerden elde edilen sonuçlara göre Al2O3+CO2 hibrit koşulunda diğer koşullara göre daha iyi performans elde edilmiştir. Al2O3+CO2 hibrit koşulunda kuru koşula göre yüzey pürüzlülüğü, kesme sıcaklığı güç tüketim sonuçlarında sırasıyla %50,98, %51,84 ve %9,37 oranında düşüş göstermiştir.The serious developments in the space and aviation sector in recent years have also contributed to the development of material technology. In parallel with the development of material technology, superalloy materials with superior properties have been developed. In addition to the superior properties of these materials called superalloys, there may be difficulties in their shaping. In order to overcome these difficulties, researchers have accelerated their work to develop sustainable methods. In this study, the Hastelloy X superalloy material used in the space and aviation field was milled under sustainable cooling/lubrication conditions. Milling experiments were carried out in two stages. In the first stage, it was aimed to investigate the effects of particle sizes of nanofluids on machining performance. For this purpose, dry, minimum quantity lubrication (MQL), 4 nm sized Al2O3, 48 nm sized Al2O3 and 136 nm sized Al2O3 nanofluid cooling/lubrication conditions were preferred. In the second stage, it was aimed to investigate the effects of dry, MQL, Al2O3 added nanofluid, vortex, CO2, MQL+vortex, nanofluid+vortex, CO2+MQL, CO2+nanofluid cooling/lubrication conditions on the machining performance. In order to investigate the effects of cooling/lubrication conditions, the cutting speed, feed rate and cutting depth parameters were taken as 50 m/min, 0.10 mm/rev and 0.5 mm, respectively. Surface roughness Ra, cutting temperature and power consumption values were determined as performance criteria. According to the results obtained from the first stage experiments, 4 nm sized Al2O3 nanofluid exhibited superior performance compared to other conditions. 4 nm sized Al2O3 nanofluid condition showed a decrease of 37.43%, 36.02% and 8.33% in surface roughness, cutting temperature and power consumption results, respectively, compared to the dry condition. According to the results obtained from the second stage experiments, better performance was obtained in Al2O3+CO2 hybrid condition compared to other conditions. In Al2O3+CO2 hybrid condition, surface roughness, cutting temperature and power consumption results decreased by 50.98%, 51.84% and 9.375%, respectively, compared to the dry condition