TR-Dizin İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/396

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Apatinib Sensitizes Human Breast Cancer Cells Against Navitoclax and Venetoclax Despite Up-Regulated Bcl-2 and Mcl-1 Gene Expressions
(Kare Publ, 2021) Kavakcioglu Yardimci, Berna; Ozgun Acar, Ozden; Semiz, Asli; Sen, Alaattin; 01. Abdullah Gül University
OBJECTIVE Defects in apoptotic cell death which restrict the success of conventional cytotoxic therapies have pivotal roles in a number of pathological conditions including cancer. However, a novel drug class targeting pro-survival Bcl-2 protein family members has been developed with the understanding of the structures and interactions of Bcl-2 proteins. Within this new class, Bcl-2/Bcl-xL inhibitor Navitoclax and Bcl-2 specific inhibitor Venetoclax have been shown to demonstrate strong anticancer activities on several types of cancers. But their low affinity to other anti-apoptotic proteins limits their clinical usage. Here, we investigated the cytotoxic and apoptotic effects of Navitoclax/Venetoclax and their combinations with specific tyrosine kinase inhibitor Apatinib on estrogen receptor (ER)-positive MCF-7 and ER-negative MDA-MB-231 breast cancer cell lines. METHODS MTT assay was used for the evaluation of the inhibition of cancer cell proliferation. ELISA test and Quantitative real-time PCR assay was performed to determine the role of caspase-3, Bak, Bax, Bcl-2, Bcl-xL and Mcl-1 proteins in the inhibition of cell proliferation triggered by the tested agents. RESULTS We found that aggressive MDA-MB-231 cell line was more sensitive to all tested agents. Apatinib significantly enhanced Navitoclax/Venetoclax mediated inhibition of cell viability in both cancer cell lines despite up-regulation in the expression levels of Bcl-2 and Mcl-1 genes. We further demonstrated significant Bak/Bax and caspase-3 expression in less aggressive MCF-7 cells. CONCLUSION Our findings have impacts on Navitoclax/Venetoclax plus Apatinib based therapy for breast adenocarcinoma. On the other hand, further studies should be conducted to elucidate the mechanisms underlying synergistic effects of Navitoclax/Venetoclax plus Apatinib combinations.
Atatürk’ün Esir Aldığı Yunan General Nikolaos Trikupis ve Talas Üsera Garnizonu
(Sabit Dokuyan, 2023) Karataş, Murat; Metin, Mehmet; 01. Abdullah Gül University; 10. Rektörlük
After the First World War, especially with the support of England, the Greek army invaded Anatolian lands on the way to realize Megali Idea (Greater Greece). The regular army of the Turkish Grand National Assembly established on the Western Front dealt the final blow to the Greek army with The Great Offensive and the Battle of the Commander –in-Chief. In addition to the Greek soldiers captured in the wars before this victory, many Greek soldiers, as well as the commander –in-chief of the Greek army, General Trikupis, and her entourage were also captured after the said victory. As the number of prisoners increased rapidly after The Great Offensive and the Battle of the Commander –in-Chief, the captive officers were transferred to Afyon, Kırşehir and Kayseri. Other military and civilian prisoners were transferred to different parts of Anatolia. Greek prisoners of war were kept in the prisoner garrisons until the implementation of the document on the mutual release of prisoners signed between the states of Turkey and Greece at the Lausanne Peace Conference. Only Greek Officers remained in Talas Prisoner Garrison, one of these prisoner garrisons. The Talas Prisoner Garrison was inspected twice by international Committee of the Red Cross. The delegation prepared reports on the condition of the prisoners and the garrison. In this study, the captivity of General Trikupis on the battlefield, the Talas Prisoner Garrison and situation of the captive Greek officers staying here, the aid of the Red Crescent Society to the prisoners will be emphasized. The Study was planned to be prepared by making use archival resources, memoirs, newspapers and copyright-reviewed works. © 2023 Elsevier B.V., All rights reserved.
Citation - WoS: 3
Combined Effect of Midostaurin and Sphingosine Kinase-1 Inhibitor on FMS-Like Tyrosine Kinase 3 (FLT3) Wild Type Acute Myeloid Leukemia Cells
(Walter de Gruyter Gmbh, 2022) Sahin, Hande Nur; Adan, Aysun; 01. Abdullah Gül University; 04. Yaşam ve Doğa Bilimleri Fakültesi; 04.02. Moleküler Biyoloji ve Genetik
Objectives Therapeutic potential of clinically approved FLT3 inhibitor midostaurin has been neglected in wild-type FLT3 positive acute myeloid leukemia (AML). Sphingosine kinase-1 (SK-1) having anti-proliferative functions is studied in various cancers, but not in FLT3 wild-type AML. We aimed to develop new therapeutic strategies to combat FLT3 wild-type AML by combining midostaurin with SK-1 inhibitor (SKI II) in THP1 cells. Methods The anti-proliferative effects of midostaurin, SKI II and in combination on THP1 cells were determined by MTT assay. The combination indexes were calculated using calcusyn software. SK-1 expression and PARP cleavage were checked by western blot. Cell cycle distributions (PI staining) and apoptosis (annexin-V/PI dual staining) were assessed by flow cytometry for each agent alone and in combinations. Results Midostaurin decreased SK-1 protein level. Midostaurin, SKI II and certain combinations decreased cell viability in a dose dependent manner. The combined anti-leukemic effects of the aforementioned drug combination afforded additive effect. Co-administration induced both necrosis and apoptosis via phosphatidylserine externalization, PARP cleavage and cell cycle arrest at G0/G1 and S phases. Conclusions Targeting sphingosine kinase-1 together with FLT3 inhibition could be a novel mechanism to increase limited clinic response to midostaurin in wild-type FLT3 overexpressing AML after further pre-clinical studies.
Citation - Scopus: 1
Comparison of Mechanical and Physical Properties of Screed With and Without Expanded Polystyrene (EPS) Particles
(Yildiz Technical University, 2022) Kiliç, Fikret Merih; Yorulmaz, Hediye; Özuzun, Sümeyye; Durak, Uğur; İLkentapar, Serhan; Karahan, Okan; Atis, C. D.; 01. Abdullah Gül University; 02.03. İnşaat Mühendisliği; 02. Mühendislik Fakültesi
In this study, in order to observe the mechanical and physical properties of ordinary screed, sandy-lightweight screed and lightweight screed samples, expanded polystyrene (EPS) was used as fine aggregate and lightweight screed systems were produced by replacing sand at 100%, 50% and 0%. Samples of cement dosages of 250, 300, 350 kg/m3 were produced for lightweight screeds, sandy-lightweight screeds and ordinary screeds. Unit weight, water absorption capacity, flexural strength, compressive strength, fire resistance, abrasion and thermal conductivity tests were performed on the produced screed systems. As a result of the research, it was determined that as EPS ratio increases in screed system; unit weights decreased, water absorption rates increased. Besides, the flexural and compressive strengths, fire and abrasion resistance are also decreased. However, it was observed that the thermal conductivity coefficient reduced with the increment of EPS particles in the screed. In normal, sandy-lightweight and lightweight screeds, it was determined that as the cement dosage increased; the unit weights, flexural and compressive strengths, fire and abrasion resistance increased, water absorption capacity and the thermal conductivity coefficient decreased. © 2022 Elsevier B.V., All rights reserved.
Cytotoxic and Cytostatic Effects of Targeting mTOR and Hedgehog Pathways in Acute Myeloid Leukemia
(Istanbul Univ, 2022) Cicek, Enes; Kucuktas, Fulya Mina; Yenigul, Munevver; Akcok, Emel Basak Gencer; 01. Abdullah Gül University; 04. Yaşam ve Doğa Bilimleri Fakültesi; 04.02. Moleküler Biyoloji ve Genetik
Objectives: Acute myeloid leukemia (AML) is a highly aggressive heterogeneous hematopoietic malignancy characterized by a rapid and abnormal proliferation of immature myeloid leukemia cells in the bone marrow and peripheral blood. Aberrant alterations in signal transduction pathways are strongly associated with the progression of AML. This study aimed to investigate cell viability and the cell cycle in AML cells by targeting the Hedgehog and mTOR signaling pathways with rapamycin and GANT61. Materials and Method: The antiproliferative effect of rapamycin and GANT61 was assessed by the MTT cell viability assay in two AML cell lines: CMK and MOLM-13. The effect of the inhibitors on cell-cycle distribution was determined using propidium iodide staining and measured with flow cytometry. Results: Rapamycin, an mTOR inhibitor, and GANT61, a Gli-1 inhibitor, decreased the cell proliferation of CMK and MOLM-13 cells. The IC20 values, which is the drug concentration that inhibits cell growth by 20%, were combined and administered to the cells. The results show the drugs to have a combinatorial inhibitory effect on CMK cells but not on MOLM-13 cells. In addition, the combination of drugs arrested the cells during the G0/G1 phase. Conclusion: This study suggests a novel combination therapy approach for AML via mTOR and Hedgehog signaling pathway inhibition using rapamycin and GANT61, respectively. It also suggest further studies be performed to reveal the mechanism of action.
Citation - Scopus: 1
Düzce Kent Merkezi Zeminlerinin Sıvılaşma Potansiyelinin Değerlendirilmesi
(TMMOB - Jeoloji Muhendisleri Odasi jmo@jmo.org.tr, 2019) Akin, Muge K.; 01. Abdullah Gül University; 02.03. İnşaat Mühendisliği; 02. Mühendislik Fakültesi
Soil liquefaction is one of the ground deformations occurred during an earthquake which may cause serious damages such as settlement and tilting of structures due to loss of bearing capacity of foundations. Düzce and its surrounding settle on a plain which consists of silty and sandy layers with shallow groundwater level. Besides, the North Anatolian Fault Zone is a major seismic source which is capable of producing large magnitude earthquakes. All these data point out that the ground deformations like liquefaction and lateral spreading may occur during a probable large earthquake around Düzce and its close vicinity. In this study, the geotechnical data of 40 boreholes drilled to determine the local ground conditions and the groundwater level in Düzce were considered. Based on the field studies, it was aimed to evaluate the liquefaction potential considering the fact that the groundwater level is shallow as well as the subsurface soil is composed of loose alluvium. Liquefaction Potential Index (LPI) and Liquefaction Severity Index (LSI) methods were taken into account and the liquefaction potential of Düzce province was determined and mapped with respect to various earthquake scenarios in GIS environment. These maps are compared on the basis of different scenarios. Accordingly, it is concluded that the liquefaction potential is high-very high in the south and south-eastern sections of the study area where the construction of new residential buildings progressively continues. © 2019 Elsevier B.V., All rights reserved.
Ethyl Vinyl Acetate (EVA) Composites With Nanoclays and Boric Acid: Thermal and Mechanical Properties
(Turkish Energy, Nuclear and Mining Research Agency, 2025) Erdem, İlker; Kapçı, Mehmet Fazıl; Avcı, Şeyma; 01. Abdullah Gül University; 02.07. Malzeme Bilimi ve Nanoteknoloji Mühendisliği; 02. Mühendislik Fakültesi
Polimerler pek çok uygulamada kullanılmaktadırlar fakat yanabilir olmaları sorun teşkil etmektedir. Polimerlere yanma dayanımı seramikler gibi (oksitler, hidroksitler, killer, vb.) inorganik malzemeler kullanılarak kazandırılabilir. Bu katkıların ilavesi polimer-inorganik kompozitlerin mekanik özelliklerini de değiştirebilir ki kompozit hazırlamada bu da dikkate alınmalıdır. Bu çalışmada etil vinil asetata (EVA) iki faklı nano-kil (ağırlıkça 20/100 oranına kadar) ve borik asit eklenerek polimerin yanmasında olası gecikme araştırılmıştır. Nano-kil ve BA ilavesinin etkisini belirlemek için saf polimer ve polimer-inorganik kompozitler için mekanik özellikler de belirlenmiştir. Hazırlanan nanokompozitlerin kimyasal yapıları (FT-IR, XRD), ısıl özellikleri (TGA), mekanik özellikleri (çekme testi) ve yanma davranışları değerlendirilmiştir. En yüksek nano-kil içeriğine sahip NC 1.4 örneği en uzun sürede yanmıştır. NC 2 örneğinin diğer örneklerden daha yüksek gerilim dayanımına ve Young katsayısına sahip olduğu bulunmuştur. Nano-killerdeki organik yüzey dönüştürücüler ve BA ilavesi nano-kil/EVA kompozitlerinin ısıl ve mekanik özellikleri üzerinde etkili olmuştur.
Citation - Scopus: 2
Evaluating the Microbial Growth Kinetics and Artificial Gastric Digestion Survival of a Novel Pichia Kudriavzevii FOL-04
(Field Crops Central Research Institute, 2022) Gumustop, Ismail; Ortakci, Fatih; 01. Abdullah Gül University
Present study aims to explore Pichia kudriavzevii FOL-04 (FOL-04)’s: i) survival against artificial gastric juice (AGJ) and artificial bile juice (ABJ), ii) growth kinetics in shake flask (SF) and fed-batch trials (FBT). Survival of FOL-04 as measured by relative cell density (RCD) against AGJ and ABJ was screened at four different pH-levels (control, 3, 2, 1.5) and ox-bile concentrations (control, 0.2%, 1%, 2%), respectively. Growth kinetics was calculated by periodic measurement of OD600 in SF (225 rpm, 30°C) or in FBT using exponential feeding regimen where pH, dissolved-oxygen and temperature were controlled at 5.5, 21%, and 30°C, respectively. The doubling-time, maximum specific growth rate, and final cell densities achieved for SF and FBT were 81.7min, 1.67, 11.79 and 170.4 min, 4.75, 37.95, respectively. RCDs calculated were similar for pH=3 and control vs both were significantly higher(p<0.05) than pH=1.5 and 2 with the latter two pH-levels were not significantly different(p>0.05). RCDs were similar across control, 0.2%, and 1% ox-bile levels(p>0.05). However, 2% ox-bile yielded significantly lower RCD (p<0.05) compared to all except 1%. FOL-04 is a potential probiotic candidate showing robustness against AGJ and ABJ and remarkable biomass increase was achieved when grown under FBT which could pave the way for developing a yeast-based probiotic using this strain. © 2023 Elsevier B.V., All rights reserved.
Citation - Scopus: 2
Kalsitik ve Dolomitik Kireçtaşlarının Çimentolu Macun Dolgunun Çevresel Davranışına Etkisi
(Chamber of Mining Engineers of Turkey, 2022) Yılmaz, Tekin; Ercikdi, Bayram; 01. Abdullah Gül University
To enhance the strength and stability of cemented paste backfill (CPB), many alkaline materials are utilised as replacement or additive to binder or tailings in CPB. However, the effect of these materials on groundwater pollution of CPB needs to be comprehensively investigated. In this study, effects of the utilization of calcitic and dolomitic limestone (CL and DL) as replacement (10 wt.%) to sulphide mine tailings (S-MT) in CPB mixture on the long-term environmental behaviour of CPB were investigated. For this purpose, CPB samples (CPBs) were subjected to dynamic tank leaching tests over 360-days and the analyses of pH, sulphate (SO4 2-) and heavy metals (HMs) on the leachates were carried out. The effects of mineralogy and microstructure on the environmental behavior of CPBs were also examined by X-ray diffractometry and porosity tests. The findings showed that with the utilization of CL and DL, the pH of leachates remained at alkaline levels and the release of SO4 2- was significantly reduced. Furthermore, the denser microstructure in CPBs of CL and DL contributed to be prevented or be remarkably reduced the HMs-releases (except Cu, Mo and Pb). The results reveal that the mechanical properties of CPB as well as its impact on the groundwater pollution should be carefully evaluated. © 2022 Elsevier B.V., All rights reserved.
Citation - Scopus: 8
Kaya Tutma Hendek Performansının 3-Boyutlu Kaya Düşme Analizleriyle Değerlendirilmesi: Akköy (Ürgüp) Örneği
(TMMOB - Jeoloji Muhendisleri Odasi jmo@jmo.org.tr, 2019) Akin, Mutluhan; Dinçer, İsmail; Orhan, Ahmet H.; Ok, Ali Özgün; Akin, Muge K.; Topal, Tamer; 01. Abdullah Gül University; 02.03. İnşaat Mühendisliği; 02. Mühendislik Fakültesi
Rockfall ditches or areas can be constructed in order to protect against rockfalls in settlements that are in danger of rockfalls when the population density is not high. Nevertheless, in the design of such protection structures, essential site-specific engineering studies and analyzes are often not carried out appropriately. Therefore, rockfallditches are occasionally not capable of preventing rockfalls. Within the scope of this study, the performance of a 2 m-deep and 1 km-long rockfall ditch excavated at the upper elevation of touristic Akköy (Ürgüp) settlement in 2012 in order to prevent the entrance of falling rocks to the residential area was evaluated on the basis of 3-dimensional rockfall analyses. According to the rockfall risk classification, the settlement is under moderate rockfall risk. The digital surface model used in 3-dimensional rockfall analyses was generated by point cloud data obtained from photogrammetric images taken by unmanned aerial vehicle. During field observations, it was determined that the dimension of the previously fallen ignimbrite blocks could reach up to 2 m. On the other hand, the high persistency of discontinuities in the source zone indicates that the dimensions of the potential rockfall blocks may be large. As a result of the 3-dimensional rockfall analyses carried out in RocPro3D software, it was defined that the falling blocks are generally caught by the ditch excavated between the source zone and the settlement, but in some sections of the ditch those blocks may continue to roll over the rockfall ditch. Eventually, Akköy settlement is still partially under the danger of rockfalls. If the rockfall ditch is not periodically cleaned in the course of time, the extent of danger will enlarge with the decrease in the capacity of the trench. © 2020 Elsevier B.V., All rights reserved.
Manganzı Demir Cevherinden Manganın Çözündürülmesinde Farklı İndirgeme Maddelerinin Etkisi
(Chamber of Mining Engineers of Turkey, 2022) Top, S.; Altiner, Mahmut; Kursunoglu, Sait; 01. Abdullah Gül University; 02.07. Malzeme Bilimi ve Nanoteknoloji Mühendisliği; 02. Mühendislik Fakültesi
IIn this paper, the manganese extraction from a manganiferous iron ore was investigated using reductive leaching. Various chemicals were used as a reducing agent to leach manganese selectively from the ore in the presence of sulfuric acid (H2SO4) solution. Firstly, optimum dissolution values were determined for selective manganese dissolution without using a reducing agent. As it was aimed at the selective extraction of manganese from the ore, the reductive leaching tests were conducted by adding the reducing agents under the following optimal parameters: a leaching time of 1 h, a stirring speed of 300 rpm, a temperature of 70°C, a sulfuric acid concentration of 1 M where the ore was leached with an extraction ratio of 11.54% Mn and 2.16% Fe. Manganese was dissolved with high efficiencies (up to 97.46%) from the ore by using different organic compounds (tartaric acid (C4H6O6), oxalic acid (C2H2O4), citric acid (C6H8O7), glucose (C6H12O6), sucrose (C12H22O11), and maleic acid (C4H4O4)) as the reducing agents. © 2022 Elsevier B.V., All rights reserved.
Citation - Scopus: 10
Paclitaxel-Loaded Polycaprolactone Nanoparticles for Lung Tumors: Formulation, Comprehensive In Vitro Characterization, and Release Kinetic Studies
(University of Ankara, 2022) Ünal, Sedat; Dogan, Osman Talha; Aktaş, Yeşim; 01. Abdullah Gül University
Objective: Today, cancer is still among the most common chronic diseases. Nanoparticular drug delivery systems prepared with biocompatible and biodegradable polymers such as polycaprolactone are rational solution for anticancer agents with poor solubility and low bioavailability. The aim of this study is to prepare paclitaxel-loaded polycaprolactone nanoparticles, which is known to be a potent anticancer, and to elucidate in vitro characteristics and release kinetic mechanisms. Material and Method: It was aimed to prepare paclitaxel-loaded polycaprolactone nanoparticles by nanoprecipitation. Preformulation studies were carried out with different molecular weights of polycaprolactone (Mw: 14.000, Mw: 80.000). Nanoparticles were coated with Chitosan or Poly-l-lysine to obtain cationic surface charge and to increase cellular interaction. Comprehensive characterization of formulations and release kinetic studies were performed. Result and Discussion: The particle size of the formulations ranged from 188 nm to 383 nm. Encapsulation efficiency increased to 77% in different formulations. SEM analysis confirmed the nanoparticles were spherical. Within the scope of in vitro release studies, the release continued for up to 96 hours and less than 50% of the therapeutic load was released in the first 24 hours. Mathematical modeling indicated that the release kinetics fit more than one model with the Korsmeyer-Peppas, Peppas-Sahlin and Weibull models, which show high correlation. © 2023 Elsevier B.V., All rights reserved.
Citation - Scopus: 2
University Librarians’ Perceptions of Artificial Intelligence, Its Application Areas in Libraries, and the Future
(University and Research Librarians Association (UNAK), 2024) Cuhadar, Sami; Gurdal, Gultekin; Erken, Mehmet; Mert, Selma; Gezer, Cagatay; Helvacıoğlu, Ece; Atli, Songül; 01. Abdullah Gül University; 10. Rektörlük
Günümüzde kütüphaneler, değişen teknoloji ve yeniliklerden etkilenen kurumlar arasında yer almaktadır. Yapay zeka teknolojilerinin popüler hale gelmesi, kütüphane hizmetlerini de dönüştürmeye başlamıştır. Bu araştırmada, Türkiye’deki üniversite kütüphanelerinin yapay zeka teknoloji ve uygulamalarının gelişim sürecinde yapmış olduğu ve yapmayı planladığı düzenlemeleri tespit etmek ve ilgili döneme özel geliştirdikleri hizmetleri belirlemek amacıyla bir anket uygulanmıştır. Anket, Türkiye’deki 208 üniversite kütüphanesinden 111 üniversite kütüphanesi yöneticisinin katılımıyla gerçekleştirilmiştir. Verilerin analizi ile üniversite kütüphanelerinin yapay zeka teknolojileri ve uygulamaları hakkındaki durumu, bilgi ve farkındalık düzeyleri belirlenmiş, eksik ve zayıf yönlerin geliştirilmesine yönelik önlemler ve öneriler sunulmuştur. İlgili araştırma, yapay zeka konusunda Türkiye’de üniversite kütüphanesi yöneticilerinden görüş ve öneri alarak gerçekleştirilen ilk ve en kapsamlı çalışmadır. Araştırma bulguları, üniversite kütüphanelerinin ChatGPT, Gemini, Grammarly vb. yapay zeka uygulamalarını belirli düzeyde kullandıklarını ancak yapay zeka ile ilgili kurumsal politika geliştirme, personele yetkinlik kazandırma ve planlama konularında ihtiyaçlarının olduğunu ortaya çıkarmıştır.

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