TR Dizin İndeksli Yayınlar Koleksiyonu / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14365/4
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Article Aronia Melanocarpa (Michx.) Meyvesindeki Fenolik, Flavonoid, Toplam Antioksidan Kapasitesi, Vitamin ve Glutatyon İçeriğinin Araştırılması(2025-09-15) Özer, Dursun; Karatas, Fikret; Saydam, Sinan; Servi, RefikAronya meyvesindeki yağda ve suda gözünen vitaminler, glutatyon miktarları yüksek performanslı sıvı kromatografisi (HPLC) ile tayin edilmiştir. Toplam fenolik ve flavonoid bileşik miktarları ve toplam antioksidan kapasitesi spektrofotometre ile belirlenmiştir. Meyvedeki vitamin A, E, β-karoten ve likopen miktarları sırasıyla 12.44±0.40, 19.51±0.51, 51.64±1.41 ve 5.85±0.17 µg/g olarak bulundu. Aronya meyvesindeki suda çözünen vitaminlerden askorbik asit, tiamin, riboflavin, nikotinik asit, pantotenik asit, pridoksin, folik asit ve siyanokobalamin miktarları sırasıyla 412.92±7.29, 4.27±0.14, 16.43±0.48, 34.13±1.01, 36.37±0.59, 3.43±0.12, 14.0±0.55, 5.33±0.14 µg/g, iken redükte ve okside glutatyon (GSH, GSSG) miktarları ise 706.32±11.25, 133.67±4.79 µg/g olarak belirlendi. Meyvelerdeki toplam fenolik madde miktarı 81.28±1.86 µg Gallik Asit/g, flavonoid madde miktarı ise 65.55±1.45 µg Kuersettin/g olarak belirlenmiştir. Aronya meyvesindeki DPPH yöntemine göre belirlenen IC50 değeri 23.17±0.78 µg/mL, TEAK yöntemine göre hesaplanan antioksidan kapasite değeri ise 272.85±6.31 µmol Troloks/g olarak bulunmuştur. Olgun aronya meyvesindeki vitaminler, glutatyon, toplam fenolik ve flavonoid madde miktarları ile toplam antioksidan kapasite bakımından uygun dozda tüketildiğinde sağlık için yararlı olduğu söylenebilir.Article Porphyridium Cruentum as a Biological Component for the Green Synthesis of Metal Nanoparticles and for the Evaluation of Their Antimicrobial Activity(Field Crops Central Research Institute, 2025-08-21) Mutaf, Tugce; Çalışkan, Gülizar; Oncel, Suphi; Elibol, Murat; Mutaf-Kilic, TugceSilver nanoparticles are an alternative to new-generation antimicrobial agents with their antimicrobial activity. Iron and zinc nanoparticles can potentially be used as UV protection in various applications. Nowadays, green synthesis of nanoparticles as a sustainable alternative attracts attention. Microalgae are promising in nanoparticle synthesis among biological sources due to their high biomass productivity and heavy metal accumulation ability. The present study aimed to investigate the potential of synthesizing intracellular silver, zinc and iron nanoparticles from Porphyridium cruentum microalgae. For nanoparticle synthesis, the effects of metal solution concentration and amount of biomass on particle size were investigated. The nanoparticles were characterized by dynamic light scattering, UV-vis spectrophotometry, and antimicrobial activity test. Silver nanoparticles of 169.7 nm, zinc nanoparticles of 189 nm, and iron nanoparticles of 356.7 nm were characterized by DLS. 169.7 nm silver nanoparticles were synthesized with 9.83 mM AgNO3 concentration and 0.19 mg/ml biomass: metal solution mixing ratio. The surface plasmon resonance band of silver nanoparticles was observed in the 300-350 nm wavelength range. According to the antibacterial activity results of silver nanoparticles, inhibition zone diameters were obtained as 10.83±0.76 mm and 11.33±0.57 mm against Escherichia coli and Staphylococcus aureus bacteria, respectively.Article Bibliometric Analysis on Methods and Tools Developed for DGE Analysis: Current Trends and Future Perspectives(2025-04-29) Kochan, NeclaDiferansiyel gen ekspresyonu (DGE) analizi, yeni nesil dizileme teknolojilerinin ortaya çıkışıyla önemli bir ilgi kazanmıştır. Bu durum, DGE analizi için çeşitli yöntemlerin ve araçların geliştirilmesine yol açmıştır. Bu çalışmada, Biblioshiny ve VOSviewer yazılımları kullanılarak, incelenen dönem boyunca eğilimleri araştırmak amacıyla bibliyometrik analiz yapılmıştır. 2005-2023 yılları arasında Web of Science veri tabanından, diferansiyel gen ekspresyonu ile ilgili terimleri konu alan ilgili makaleler taranmıştır. İncelenen dönem boyunca yayımlanan eğilimleri göstermek için Biblioshiny ve VOSviewer yazılımları kullanılarak ağ haritaları oluşturulmuştur. Toplamda 729 çalışma, DGE analizi metodolojilerindeki, araçlarındaki ve paketlerindeki eğilimleri ortaya koymak amacıyla incelenmiştir. Bu amaçla, ülke, kurum, kaynak, yazar ve anahtar kelime üretkenliği açısından eş-yazarlık, bibliyografik eşleşme ve eş-oluşum analizleri yapılmıştır. 2005 yılından sonra çıktı ve atıf sayılarında artış gözlenmiştir. Çalışma süresince ABD ve Çin, DGE analizine en çok katkı sağlayan ülkeler olarak öne çıkmıştır. Zamansal çalışmalar, belirli aralıklarla bir miktar azalma olmakla birlikte, zaman içinde yayınlarda önemli bir artış olduğunu ortaya koymuştur. En büyük düşüş, 2008 ile 2010 yılları arasında gözlenmiştir. Bu düşüşlere rağmen, DGE analizi, herhangi bir hastalığın mekanizmalarını, gen işlevlerini ve terapötik hedefleri anlamadaki temel rolü nedeniyle genomikte kritik bir konu olmaya devam etmektedir. Bu eğilim, mevcut yöntemlerin ve araçların, çeşitli hastalıklarla ilişkili anahtar bilgilendirici genleri tanımlamak için yeterince güçlü kabul edildiğini göstermektedir.Article A Comparative study of DNA Alignment Algorithms and Boosting Performance Using Different Compilation Strategies(2024-12-30) Doluca, OsmanYeni nesil sekanslama teknolojilerinin yaygınlaşması ve biyolojik verilerin çoğalması ile beraber DNA ve protein dizi hizalama algoritmalarının daha yüksek performans ile calıştırılmasına olan ihtiyaç artmıştır. Bu çalışma iki iyi bilinen, Needleman-Wunsch ve Smith-Waterman, DNA ve Protein dizi hizalama algoritmalarının Python programlama dilinde farklı derlenme stratejilerinin sistematik kıyaslamasıdır. Sıkça kullanılan Biopython’un ikili hizalama modülü ile kendi yazdığımız yazılımın farklı derleme yaklaşımlarının performans farkının kıyaslanması amaçlanmıştır. Sonuçlar Numba’nın just-in-time derleme yönteminin PyPy ve Cython derleme yöntemleri ya da Biopython modülüne kıyasla genel olarak daha yüksek performans gösterdiğini ortaya koymuştur. Bu çalışmanın geniş çapta dizi hizalama gerektiren yazılım protipleme çalışmalarında verimliliği arttıracağı düşünülmektedir.Article Upregulated Acute Systemic Inflammation-Related Genes Based on Endotoxin Exposure Provide ‘Survival Benefit’ or Create ‘High Risk of Death’ in Leukaemia and Colon Cancer(Istanbul University, 2024-07-10) Duran, Gizem Ayna; Duran, Assist. Prof. Dr. Gizem Ayna; Ayna Duran, GizemObjective: Although endotoxin exposure has been shown to trigger innate immune responses and promote cancer, it has also been shown to prevent cancer formation. In our study, survival analysis was performed to determine whether the upregulated genes triggered by endotoxins have hazardous effects on cancers or provide a survival benefit. Materials and Methods: Gene intensity values of control and bacterial endotoxin-administered individuals were obtained from the Gene Expression Omnibus database. Using the R "Linear Models for Microarray Data" package, differentially expressed gene analyses were conducted to determine genes that differ between healthy and bacterial endotoxin-administered samples. "ShinyGo 0.80" web-based tool was used to determine the disease types indicated by these genes. The "Kaplan-Meier Plotter" web-based tool was used to conduct survival analysis. Results: Genes that create an innate immune response to bacterial endotoxin exposure and are upregulated differently than in individuals without exposure were identified. According to gene enrichment analyses, the two main types of cancer identified were leukaemia/lymoma and colon cancer. We detected that MLF1, STAT5B, and BCL3 genes led to poor survival; however, the ARHGAP26 gene was protective for acute myeloid leukaemia patients. In the case of colon cancer, SMAD7 and TLR2 genes were determined as leading to "high risk of death". Conclusion: Once the systemic inflammation-related genes identified in our study are confirmed through laboratory experiments in samples taken from solid tissue in the case of colon cancer and at the level of genes obtained from blood samples in leukemias, genetically targeted treatments will also be possible.Article Bioinformatics Based Drug Repurposing Approach for Breast and Gynecological Cancers: RECQL4/FAM13C Genes Address Common Hub Genes and Drugs(Galenos Publ House, 2025-01-02) Duran, Gizem Ayna; Duran, Assist. Prof. Dr. Gizem AynaObjective: The prevalence of breast cancer and gynaecological cancers is high, and these cancer types can occur consecutively as secondary cancers. The aim of our study is to determine the genes commonly expressed in these cancers and to identify the common hub genes and drug components. Materials and Methods: Gene intensity values of breast cancer, gynaecological cancers such as cervical, ovarian and endometrial cancers were used from the Gene Expression Omnibus database Affymetrix Human Genome U133 Plus 2.0 Array project. Using the linear modelling method included in the R LIMMA package, genes that differ between healthy individuals and cancer patients were identified. Hub genes were determined using cytoHubba in Cytoscape program. “ShinyGo 0.80” tool was used to determine the disease-specific biological KEGG pathways. Drug.MATADOR from the ShinyGo 0.80 tool was used to predict drug-target relationships. Results: The RecQ Like Helicase 4 and Family with Sequence Similarity 13 Member C genes were found to be similarly expressed in breast cancer and gynaecological cancers. Upon KEGG pathway analyses with hub genes, Drug.MATADOR analysis with hub genes related to cancer related pathways was performed. We have determined these gene/drug interactions: NBN (targeted by Hydroxyurea), EP300 (targeted by Acetylcarnitine) and MAPK14 (targeted by Salicylate and Dibutyryl cyclic AMP). Conclusion: The drugs associated with hub genes determined in our study are not routinely used in cancer treatment. Our study offers the opportunity to identify the target genes of drugs used in breast and gynaecological cancers with the drug repurposing approach.Article Fluorescence Microscopy Denoizing Via Neighbor Linear Embedding(Istanbul University, 2024-01-31) Kırmızıay, Çağatay; Aydeniz, Burhan; Türkan, MehmetOne of the difficulties in studying fluorescence imaging of biological structures is the presence of noise corruption. Even though hardware- and software-related technologies have undergone continual improvement, the unavoidable effect of Poisson–Gaussian mixture type is generally encountered in fluorescence microscopy images. This noise should be mitigated to allow the extraction of valuable information from fluorescence images for various types of biological analysis. Thus, this study introduces a new and efficient learning-based denoizing approach for fluorescence microscopy. The proposed approach is based mainly on linear transformations between noise-free and noisy submanifold structures of patch spaces, benefiting from linear neighbor embeddings of local image patches. According to visual and statistical results, the developed algorithm called "neighbor linear-embedding denoizing" algorithm has a highly competitive and generally superior performance in comparison with the other algorithms used for fluorescence microscopy image denoizing in the literature. © 2024 Istanbul University. All rights reserved.Article Identification of the Role of Tg2 on the Expression of Tgf-Β, Timp-1 and Timp-2 in Aged Skin(Walter De Gruyter Gmbh, 2024-02-12) Ergülen, Elvan; Akdoğan, Gül; Guner, Gul AkdoganObjectives Transglutaminase 2 (TG2) is a unique protein having enzymatic and nonenzymatic functions that have been implicated in various biological and pathological processes such as cell survival and apoptosis, cell signaling, differentiation, adhesion and migration, wound healing and inflammation. As reported in previous studies, TG2 expression and activity increase by age suggesting that TG2 possibly has roles in cellular aging process. In this study, we aimed to explore the role of TG2 in chronological skin aging through its impact on the expression of some important extracellular matrix (ECM) proteins including TGF-beta, TIMP-1 and TIMP-2. Methods We have compared TG2 expression and activity in young and in vitro chronologically aged human dermal fibroblasts via Western blot and in situ TG2 activity assays. Afterwards, we inhibited TG2 expression via siRNA transfection and activity via active site inhibitor of TG2 separately in aged dermal fibroblasts and monitored the expression levels of TGF-beta, TIMP-1 and TIMP-2 in these cells by Western blot and compared to that of untreated control cells. Results We obtained evidence that both TG2 expression and activity increase in aged cells. However, protein levels of TGF-beta, TIMP-1 and TIMP-2 do not exhibit any significant difference in TG2 downregulated or TG2 activity inhibited aged cells compared to control cells. Conclusions Our results indicate that changes in the expression and activity of TG2 in (in vitro) chronologically aged human dermal fibroblasts do not impact the expression patterns of TGF-beta, TIMP-1 and TIMP-2 proteins.Article Citation - WoS: 2Differences in the Differential Expression of Micrornas Between Patients With Familial Multiple Sclerosis and Those With Sporadic Multiple Sclerosis(Galenos Publ House, 2023-12-28) Güllüoğlu, Halil; Uysal, Hasan Armağan; Poyraz, Turan; Altun, Zekiye; Kaya, Derya; Özcelik, Pınar; İdiman, Egemen; Poyraz, TuranObjective: Multiple sclerosis (MS) is a heterogeneous disease with clinical and immunological features. Most MS cases occur sporadically, but a considerable proportion of patients have a family history of MS. The etiology and pathophysiology of MS remain unclear. Recent epidemiological and gene expression studies have indicated that dysregulation of microRNAs (miRNAs) may play a role in MS pathogenesis. This study aimed to evaluate the differential expression of miRNAs in sporadic MS (sMS) and familial MS Materials and Methods: This cross-section, single-center study was conducted in 20 FMS and 10 sMS patients and 8 healthy controls. The patients were in the remission. In total, 2,549 miRNA genes were screened in the blood mononuclear cells from the whole blood samples of MS patients depending on miRBase 21. Differential expression of miRNAs in MS patients was identified compared with the control group, and miRNAs with a fold change >= 2 were validated using reverse transcription-polymerase chain reaction. Differentially expressed miRNAs were then compared between FMS and sMS patients. Results: Initial findings showed that miR-5100 and hsa-miR-16-2-3p were increased and miR-432-3p was decreased in FMS compared with sMS, whereas miR-548-aa, hsa-miR-142-3p, and miR-451-b were increased in both sMS and FMS, but miR-548-v was increased only in sMS. Some miRNAs showed the same expression patterns in both groups. Conclusion: Differential expression of certain miRNAs may be a useful biomarker in the diagnosis of MS. This study showed that miRNAs may discriminate between FMS and sMS cases and MS subtypes, as indicated in earlier studies.Article Classification of Colon Cancer Patients Into Consensus Molecular Subtypes Using Support Vector Machines(2023-12-28) Koçhan, Necla; Dayanç, Barış EmreBackground/aim: The molecular heterogeneity of colon cancer has made classification of tumors a requirement for effective treatment. One of the approaches for molecular subtyping of colon cancer patients is the consensus molecular subtypes (CMS), developed by the Colorectal Cancer Subtyping Consortium. CMS-specific RNA-Seq-dependent classification approaches are recent, with relatively low sensitivity and specificity. In this study, we aimed to classify patients into CMS groups using their RNA-seq profiles. Materials and methods: We first identified subtype-specific and survival-associated genes using the Fuzzy C-Means algorithm and log- rank test. We then classified patients using support vector machines with backward elimination methodology. Results: We optimized RNA-seq-based classification using 25 genes with a minimum classification error rate. In this study, we reported the classification performance using precision, sensitivity, specificity, false discovery rate, and balanced accuracy metrics. Conclusion: We present a gene list for colon cancer classification with minimum classification error rates and observed the lowest sensitivity but the highest specificity with CMS3-associated genes, which significantly differed due to the low number of patients in the clinic for this group.