İstanbul Sağlık ve Teknoloji Üniversitesi Kurumsal Akademik Arşivi
DSpace@İSTÜN, Üniversite mensupları tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Aloe vera-derived Ag-doped TiO2 nanoparticles immobilized by chitosan films for photo(electro)catalytic and antimicrobial functions
(Elsevier, 2025) Kaba, İbrahim; Bozkurt, Rabia Nur; Altıner Kurt, Eda; Kerkez Kuyumcu, Özge; Koca, Atıf
In this study, as an environmentally friendly and sustainable approach, TiO2 nanoparticles (TiO2 NPs) were prepared by green synthesis method using deep eutectic solvent (DES, ChCl/glycerol (1:2)) based Aloe vera leaves extract obtained by Soxhlet extraction. The DES system functioned concurrently as a green solvent and a functional medium, while the bioactive chemicals in the Aloe vera leaves extract operated as natural reducing and stabilizing agents. The produced TiO2 NPs were doped with silver (Ag) at molar ratios of 0.25, 0.50, and 0.75, and immobilized on a chitosan matrix (Ag/TiO2-CS) to facilitate recovery from the reaction media. The materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), photoluminescence (PL) spectroscopy, scanning electron microscopy-energy dispersive X ray analysis (SEM-EDX) and X-ray photoelectron spectroscopy (XPS). Characterization validated the TiO2 phase, effective Ag incorporation, diminished band gap energy (from 3.34 eV to 2.83 eV), and uniform nanoparticle distribution. PL measurements confirmed that Ag doping reduces carrier charge recombination. The 0.50Ag/ TiO2-CS film displayed the best photocatalytic degradation efficiency for malachite green (93.3 %) under solar irradiation and exhibited a higher photocurrent response relative to undoped TiO2. Moreover, antimicrobial assays demonstrated that 0.50 and 0.75 Ag/TiO2 NPs exhibited significant suppression of S. aureus and E. coli, with low minimum inhibitory concentrations (MIC) (0.40–0.20 µg/mL) and minimum bactericidal concentra tions (MBC), signifying robust bactericidal efficacy. The findings indicate that DES-assisted Aloe vera-mediated synthesis provides an economical and scalable method for producing multifunctional nanocomposites with considerable potential in environmental remediation and biomedical fields.
The role of exosomal micrornas in cancer metastasis: An in-depth guide
(Türk Radyasyon Onkolojisi Derneği, 2025) Tahan, Rana; Yazıcı, Hülya
Exosomes and their contents play a vital role in forming a unique communication system that carries and transmits signal molecules, which alter the physiological state of cells and are linked to the on set and progression of numerous diseases including cancers. Focusing on exosomal cargo, microRNAs (miRNAs), which are small non-coding, single-stranded RNAs that regulate gene expression of target genes, are suggested to be transferred via exosomes in a selective manner that facilitates cancer progres sion and dissemination. In this context and through ongoing cancer research, researchers have currently been focusing on exosomal microRNA as a specific communication message delivered from cancer cells to the other cells that plays a crucial role in the immune response, tumor migration, tumor cell invasion, and development of metastasis In this review, we aim to evaluate the expected role of exosome-derived microRNAs in the development of cancer metastasis and their possible role of molecular markers in metastasis sites by the current literature on cancer research.
Çobanoğlu çekme helva işletmesi
(Gazi Kitabevi, 2025) Şensoy, Necdet; Şensoy, Fatma; Durmuş, Ahmet Fethi; İnanç, Rıdvan; Çemberlitaş, İbrahim; Yücel, Göksel; Kurt, Ganite; Adiloğlu, Burcu
Çobanoğlu Çekme Helva işletmesi, Kastamonu'nun geleneksel gıda üretiminde öne çıkan örneklerinden biridir. 1994 yılında Coşkun Çobanoğlu tarafından kurulan işletme, başlangıçta küçük ölçekli bir üretim tesisi olarak faaliyet göstermiştir. Kuruluş sürecinde sınırlı sermaye ve yoğun emek gücü ile üretim yapılırken, zamanla teknolojik gelişmelerin de etkisiyle makineleşmeye geçilmiştir. İşletme sahibi, görüşme sırasında özellikle 1994 sonrasında üretimde modern makinelerin kullanılmaya başlandığını ve bugün üretimin yaklaşık %60'ının makine destekli gerçekleştiğini, geri kalanının ise geleneksel yöntemlerle sürdürüldüğünü ifade etmiştir. Bu durum, işletmenin hem modern üretim kapasitesine ulaşmasını hem de geleneksel tat ve kalitenin korunmasını sağlamaktadır.
Elimination of hepatitis c in Turkey
(IntechOpen, 2025) Örmeci, Necati; Musabaev, Erkin Isakovich
This manuscript examines the epidemiological patterns, transmission routes, and genotypic distribution of hepatitis C virus (HCV) in Türkiye, highlighting national progress toward elimination targets set by the World Health Organization (WHO). The main objective is to evaluate the effectiveness of national screening, diagnostic, and treatment strategies, with a focus on the scale-up of direct-acting antiviral (DAA) therapies and their associated cost-effectiveness. Drawing on recent multicenter and population-based studies, the paper outlines the shifting prevalence of HCV geno types, particularly among high-risk populations such as people who inject drugs (PWID), prisoners, and individuals undergoing hemodialysis. The analysis demon strates that genotype 1b remains predominant, though genotype diversity is increas ing due to migration and changing transmission dynamics. Findings reveal that despite improved availability of DAA treatments and health policy initiatives like the 2018–2023 National Viral Hepatitis Program, gaps persist in diagnostic follow-up and referral. The manuscript emphasizes the dual approach of micro- and macro elimination, advocating for integrated care models, increased physician engagement, and enhanced awareness efforts. Projections suggest that achieving WHO goals is feasible in Türkiye if testing and treatment rates significantly improve. Ultimately, this study underscores the necessity of sustained political commitment, intersectoral collaboration, and targeted public-health interventions to reduce HCV-related mor bidity and mortality by 2030.
A high geometric albedo and small size for the haumea cluster member (24835) 1995 SM55 determined from a stellar occultation and photometric observations
(EDP Sciences, 2025) Ortiz, Jose L.; Morales Palomino, Nicolas F.; Sicardy, Bruno; Rommel, Flavia Luane; Braga Ribas, Felipe; Kılıç, Yücel; Fernández-Valenzuela, Estela; Rizos García, Juan Luis; Solmaz, Arif; Morgado, Bruno
Context. Trans-Neptunian objects (TNOs) are thought to be some of the most ancient and primitive bodies in our Solar System. Understanding their basic physical properties is crucial to unraveling their origin and the evolution of the outer Solar System beyond Neptune. Stellar occultations are a highly effective and sensitive method of studying these distant and faint objects, allowing us to gather essential information about their physical characteristics. (24835) 1995 SM55 is one of the few members of the Haumea orbital cluster and, therefore, is an especially relevant body to study within the TNO population. Aims. The main objectives of the present work are to determine the projected size, absolute magnitude, and geometric albedo of 1995 SM55 and to analyze the results compared to Haumea. Methods. We predicted a stellar occultation by this TNO for February, 25, 2024, carried out a specific campaign to observe the occultation, and derived the projected size and shape from the occultation observations using an elliptical fit to the occultation chords. We also analyzed a large set of photometric observations of (24835) 1995 SM55 to obtain the absolute magnitude and the rotational period. Finally, we combined these results to derive the geometric albedo of this TNO. Results. The occultation was successfully detected from seven instruments located at five different sites; 33 other sites reported negative detections. Using an elliptical fit to the occultation chords, we determined the size and shape of the limb of (24835) 1995 SM55 during the occultation: an ellipse with semi-axes (104.3 ± 0.4) × (83.5 ± 0.5) km. The area-equivalent diameter (Deq,A) for this ellipse is 186.7 ± 1.8 km. This is consistent with the upper limit of 250 km estimated from Herschel Observatory thermal data. From our photometric observations, we derived an absolute magnitude (HV ) of 4.55 ± 0.03, a phase slope parameter of 0.04 ± 0.02 mag/deg, and a V − R value of 0.37 ± 0.05. The rotational variability has a maximum peak-to-valley amplitude (∆m) of 0.05 mag, but we could not derive an unambiguous rotational period. Combining the projected size from the occultation with the absolute photometry, we obtained a geometric albedo in the V band (pV ) of 0.80 ± 0.04 for 1995 SM55. This value is remarkably high for a TNO and somewhat higher than that of Haumea, but consistent with the concept that 1995 SM55 is a member of the orbital cluster of Haumea.
