TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7149
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Article Can Fish Kills in Izmir Bay Be Explained With Satellite Image Analysis(Osman Orhan, 2025) Elçi, Sebnem; Erdem, Ahmet Adnan; Şekerci, HalilMotivated by a significant environmental crisis that emerged, where large numbers of dead fish washed ashore in İzmir Bay in the summer of 2024, this study aims to analyze the spatial and temporal dynamics of water quality in the inner bay prior to this incidence. By calculating indices such as NDCI, SABI, and UWQV, and correlating them with climatic data (air temperature, wind speed and relative humidity), this research seeks to document the occurrence and drivers of algal blooms in the bay using Landsat 8 and Sentinel-2 satellite data from 2017 to 2025. This is the first comprehensive study conducted for İzmir Bay that investigates the relationships between water quality indices and climatic variables. It also incorporates aerial analysis of the inner bay to provide a broader spatial perspective. A customized code using Python is developed for this study to independently download and analyze raw satellite data with respect to defined corrections/masks. The results of eight years of analysis indicated that critical conditions arise every summer with air temperatures reaching 40 degrees in the study area. Estimated aerial averaged NDCI index and Chl-a concentration values show a strong positive correlation with air temperature, particularly in the Spearman’s rank correlation (rs = 0.67 and 0.62 respectively), indicating a significant relationship between these parameters. Aerial distribution of the indices for the selected critical dates also revealed a significant increase in estimated Chl-a levels during the summer months, specifically in the regions determined from the risk maps produced as a result of this study. The areas with the greatest vulnerability coincide where Poligon, Ilıca streams in the south and Bostanlı and Çiğli streams in the north discharging into the bay. It is recommended that any planned external intervention methods for managing algal blooms should start with these highly vulnerable areas as presented by this study.Article Kentlerin Depreme Dirençliliğinin Bina Bazlı Bölgesel Risk Dağılımı Yöntemi İle İncelenmesi: İzmit Kenti Örneği(Afet ve Acil Durum Yonetimi Baskanligi, 2024) Kurt, Deniz Gerçek; Guven, Ismaıl Talıh; Erdogan, HakanTürkiye, yıkıcı deprem üretme potansiyeli yüksek fay hatlarının yer aldığı bir bölgede konumlanmaktadır. Tarih boyunca, Anadolu yarımadasında meydana gelen depremler büyük can ve mal kayıplarına sebep olmuştur. Bu bağlamda, nüfusun ve sanayileşmenin çok yoğun olduğu Marmara Bölgesinde deprem risk değerlendirme çalışmalarının yoğunlaşması ve gerekli önlemlerin alınması büyük önem arz etmektedir. Bu çalışmada, 6306 sayılı \"Afet Riski Altındaki Alanların Dönüştürülmesi Hakkında Kanun\" kapsamında tanımlanan binaların bölgesel deprem riski dağılımının belirlenmesi için riskli yapıların tespitine ilişkin esaslar başlığı altında öngörülen basitleştirilmiş yöntemler kullanılarak Kocaeli ili İzmit ilçesinde bulunan 19940 bina incelenmiştir. Söz konusu yöntem, hızlı sokak taraması prensiplerini dikkate alarak bölgesel deprem risk önceliklendirmesini hedeflemektedir. Saha incelemelerinden elde edilen sonuçlar, nüfus yoğunluğu ve dağılımı, acil toplanma alanı dağılımı, toplam yapı alanı gibi parametrelerle beraber değerlendirilerek İzmit ilçesinde deprem risk öncelikli bölgelerin belirlenmesine çalışılmıştır.Article Gypsophila Eriocalyx Roots Inhibit Proliferation, Migration, and Tgf-Β Signaling in Melanoma Cells(Walter de Gruyter GmbH, 2025) Azbazdar, Yagmur; Ozhan, Gunes; Helvacioglu, SelinObjectives: Melanoma is a highly malignant and serious form of skin cancer. In addition to the standard treatments, complementary approaches, including phytotherapy, are also used to alleviate symptoms and improve patient well- being. This study aims to investigate the anticancer effects of Gypsophila eriocalyx (GE), an endemic species from Türkiye, on melanoma cells. We set out to determine the efficacy of GE in inhibiting melanoma cell proliferation, migration, and growth, and to explore its underlying mechanisms. Methods: We examined the impact of GE on the prolifera- tion of two melanoma cell lines, Malme-3M and SK-MEL-28, and assessed its developmental toxicity in zebrafish em- bryos. Next, we evaluated GE’s influence on colony forma- tion and wound healing in melanoma cells, as well as its ability to induce apoptosis and affect the TGF-β/Smad signaling pathway, by measuring pathway reporter activity and target gene expression. Results: GE inhibited cell proliferation in melanoma cell lines at concentrations 104 to 488 times lower than those required for normal non-malignant L929 fibroblast cells. In zebrafish embryos, GE demonstrated developmental toxicity only at concentrations above 50 μg/mL. GE treatment significantly impaired the colony formation and wound healing abilities of melanoma cells, indicating reduced pro- liferation and migration. Moreover, GE induced apoptosis in melanoma cells and inhibited the TGF-β/Smad signaling pathway, as evidenced by decreased pathway reporter activity and target gene expression. Conclusions: This study highlights the potential of GE as a novel therapeutic agent in melanoma treatment by demon- strating its ability to inhibit tumor growth and progressionArticle Citation - Scopus: 3University Librarians’ Perceptions of Artificial Intelligence, Its Application Areas in Libraries, and The Future(University and Research Librarians Association (UNAK), 2024) Gürdal, Gültekin; Çuhadar, Sami; Mert, Selma; Gezer, Çağatay; Helvacıoğlu, Ece; Arus, Oya; Aslan, Özlem; Karslı, Melahat; Sönmez, Çiğdem; Taş, Ali; Açıkalın, Cansu; Mazlumoğlu, Ayça Aydemir; Erken, Mehmet; Yılmaz, Müberra; Çerkez, Özlem Araz; Uğur, Emrullah; Menemenlioğlu, Alper; Şenoğlu, Aysel; Atlı, Songül; Cuhadar, Sami; Gurdal, Gultekin; Erken, Mehmet; Mert, Selma; Gezer, Cagatay; Helvacıoğlu, Ece; Atli, SongülGünümüzde 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 olduğu ortaya çıkmıştır.Article Citation - WoS: 1Citation - Scopus: 1Investigation of Flow and Heat Transfer Performance of Gyroid Structure as Porous Media(Turkish Soc Thermal Sciences Technology, 2024) Genc, Alper Mete; Karadeniz, Ziya HaktanThere are active and passive methods used to improve heat transfer. One of the passive methods is utilising porous media with high heat transfer surface area. Porous media are divided into two groups: regular and irregular structures. One of the regular structures is triply periodic minimal surfaces (TPMS), which have been studied quite frequently recently. In this study, heat transfer and flow analysis of a Gyroid geometry, one of the most used TPMS in the literature, is investigated numerically considering the conjugate heat transfer conditions. A single porosity is considered (epsilon = 0.6), and aluminium, ceramic and PLA are selected for the heat exchanger material to examine the temperature change in the heat exchanger. To understand the different flow characteristics, Reynolds numbers are assumed to be 19.12, 95.61 and 172.09. The fluid inlet temperature is assumed to be constant at 298.15 K, and the initial temperature of the heat exchanger is assumed to be constant at 278.15 K to be consistent with the regenerative heat recovery temperature difference in ventilation standards. Nusselt numbers under different operating conditions are compared, and it is the ceramic material with low thermal diffusivity is at the highest level despite its low thermal conductivity. At the highest Reynolds number, it provided approximately 6% better heat transfer than the aluminium heat exchanger.Article Cytoplasmically Localized Trna-Derived Fragments Inhibit Translation\rin Drosophila S2 Cells(2022) Hamıd, Syed Muhammad; Akgül, BünyaminTransfer ribonucleic acids (tRNAs) serve not only as amino acid carriers during translation but also as a template for the biogenesis of short fragments that can regulate gene expression. Despite recent progress in the function of tRNA-derived fragments (tRFs), their intracellular localization, protein partners, and role in regulating translation are not well understood. We used synthetic tRFs to investigate their localization and function in Drosophila S2 cells. Under our experimental setting, all synthetic tRFs tested were localized at distinct sites within the cytoplasm in a similar manner in Drosophila S2 cells. Cytoplasmically-localized tRFs were positioned in close proximity to GW182 and XRN1 proteins. Functionally, tRFs, which slightly suppressed proliferation in S2 cells, inhibited translation without any major shift in the polysome profile. These results suggest that 5’-tRFs are cytoplasmically-localized and regulate gene expression through inhibition of translation in Drosophila.Article Citation - Scopus: 3Zinc Borate Chemical Garden and Zinc Borate Powders From Tincal Mineral and Zinc Sulfate Heptahydrate(Turkish Energy Nuclear and Mining Research Institute, 2021) Gönen, Mehmet; Alp, Fatma Burcu; Savrık, Sevdiye; Balkose, DevrimThe formation of the first membrane, the swelling of the crystal by incoming water from the semipermeable membrane and the formation of irregular shaped branches were observed by optical microscopy, when zinc sulfate heptahydrate crystals were immersed in saturated borax solution. The powders obtained by mixing dilute aqueous borax and zinc sulfate solutions had B, O, Na, S and Zn elements. Presence of $Na Zn_{1/2}B_4O_7.xH_2O$ was indicated by EDX analysis. The molar ratio of $B_2O_3/ZnO$ in powders was around 2. FTIR analysis indicated the ratio of absorbance values of asymmetric stretching vibrations of B(3)-O at 1351 cm-1 to that of B(4)-O at 1026 cm-1 increased with their heating time at 90ºC during their preparation. X-ray diffraction patterns indicated the presence of $Zn(OH)_2and Zn_4(OH)_6(SO_4)·4H_2O$. The zinc borate compounds in the powders were not crystalline since no sharp peaks related to zinc borates were present in x-ray diffraction diagram. There were two mass loss steps in TG curves of the powders. The first step at 150-350ºC and the second step at 700-950ºC were due to elimination of water and due to decomposition of sulfate ions respectively. The submicron powders were a mixture of zinc borate, $Zn(OH)_2, Zn_4(OH)_6(SO_4)·4H_2O and Na Zn_{1/2}B_4O_7.xH_2O$ and they could be used as lubricant additive due to their small particle size of 600 nm.Article Lubricants Having Zinc Borate by Homogeneous Precipitation and Span 60 in Spindle Oil(Turkish Energy Nuclear and Mining Research Institute, 2021) Gönen, Mehmet; Alp, Burcu; Savrık, Sevdiye; Balköse, Devrim; Alp, Fatma Burcu; Balkose, DevrimNano particles of zinc borate were obtained by homogeneous precipitation method which is based on dissolving zinc borate in ammonia and precipitating it as nano particles by slow evaporation of ammonia. The synthesized zinc borates were characterized by advanced analytical techniques. Zinc borate nano particles were used as a lubricant additive to spindle oil having Span 60 dispersant. The particles were well dispersed in spindle oil as shown by optical microscopy of the oils. Four ball tests of the lubricants indicated zinc borate lowered (61.8%) the wear scar diameter significantly. The hardness of wear surfaces of test balls was reduced from 688 HV to 618 HV and presence of zinc borate particles embedded on the surface indicated a flexible skin was formed. Therefore the pressure was decreased due to increase of the contact area of the balls. The surface roughness was also decreased from 35.63 nm to 27.60 nm by the addition of zinc borate to spindle oil having Span 60. Zinc borate prepared by homogeneous precipitation technique lowered the wear of the surfaces that rub to each other.Article Citation - WoS: 4Citation - Scopus: 3Expression Patterns of M6a Rna Methylation Regulators Under Apoptotic Conditions in Various Human Cancer Cell Lines(TUBITAK, 2024) Alasar, Azime Akçaöz; Sağlam, Buket; Vatansever, İpek Erdoğan; Akgül, BünyaminBackground/aim: Cancer is a complex disease that involves both genetic and epigenetic factors. While emerging evidence clearly suggests that changes in epitranscriptomics play a crucial role in cancer pathogenesis, a comprehensive understanding of the writers, erasers, and readers of epitranscriptomic processes, particularly under apoptotic conditions remains lacking. The aim of this study was to uncover the changes in the expression of m6A RNA modifiers under apoptotic conditions across various cancer cell lines. Materials and methods: Initially, we quantified the abundance of m6A RNA modifiers in cervical (HeLa and ME180), breast (MCF7 and MDA-MB-231), lung (A549 and H1299), and colon (Caco-2 and HCT116) cancer cell lines using qPCR. Subsequently, we induced apoptosis using cisplatin and tumor necrosis factor-alpha (TNF-α) to activate intrinsic and extrinsic pathways, respectively, and assessed apoptosis rates via flow cytometry. Further, we examined the transcript abundance of m6A RNA modifiers under apoptotic conditions in cervical, breast, and lung cancer cell lines using qPCR. Results: Overall, treatment with cisplatin increased the abundance of m 6A modifiers, whereas TNF-α treatment decreased their expression in cervical, breast, and lung cancer cell lines. Specifically, cisplatin-induced apoptosis, but not TNF-α-mediated apoptosis, resulted in decreased abundance of METTL14 and FTO transcripts. Additionally, cisplatin treatment drastically reduced the abundance of IGF2BP2 and IGF2BP3 readers. Conclusion: These results suggest that the differential response of cancer cells to apoptotic inducers may be partially attributed to the expression of m6A RNA modifiers.Article Accessibility in Intensive Care Units: a Qualitative Study on Exploring Architects’ Perspective(İstanbul Teknik Üniversitesi, 2023) Khoojıne, Negar Sioofy; Kasalı, Altuğ; Bayar, Mualla ErkılıçThisstudyaddresseshealthcaredesigners’perspectivesconcerningthearchitectural features within the Intensive Care Unit (ICU) environments that can impact visual and physical access to patients. In line with patient-centered approaches, providing accessible environments in ICUs is becoming increasingly critical for healthcare providers. The existing literature suggests various architectural features to influence levels of access to patients. How architects prioritize these features and translate them into the configuration of ICU environments has not been explored extensively. A series of semi-structured interviews were conducted to understand the perspectives of healthcare architects in the context of Turkey. The interviews were conducted with twelve participants with recent experiences in ICU design. The research followed a thematic analysis to link the qualitative data with the participants’ drawings that emerged during interviews. Five essential themes emerged, including: “Unit Model,” “Unit Layout,” “Unit Size,” “Bed Position,” and “Transparent Material.” The participants implied configurational models, including “open ward” and “single-patient room,” to facilitate high levels of accessibility. Beyond the key decisions concerning layouts, the participants also emphasized the strategic use of transparent materials, which was considered critical in establishing visual access within units. The findings suggest that healthcare architects mostly favor open wards as a suitable model to provide high levels of physical access by decreasing nurses’ walking distances during shifts and visual accessibility by enhancing nurses’ capacity to supervise the patients within ICU environments. The findings can advance our understanding of how the issue of access is formulated and implemented in ICU settings.