İstinye Üniversitesi Kurumsal Akademik Arşivi

DSpace@İstinye, İstinye Üniversitesi 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 yayınların etkisini artırmak için telif haklarına uygun olarak Açık Erişime sunar.

 

Güncel Gönderiler

Öğe
How reliable is the high-volume definition in prostate cancer patients: the potential game-changing role of PSMA
(Lippincott Williams & Wilkins, 2023) Guven, Osman; Karyagar, Savas; Arici, Serdar; Ozulker, Tamer; Can, Orcun
PurposeTo evaluate whether metabolic and volumetric data from Ga-68-PSMA PET/CT performed during staging of de-novo high-volume mCSPC patients who received docetaxel could be used to predict survival. MethodsForty-two de-novo high-volume mCSPC patients, who received ADT + Docetaxel and underwent Ga-68-PSMA PET/CT for staging, were included in the study. The association between patients' pathological data, all PSA measurements, treatments they received, the data obtained from Ga-68-PSMA PET/CT and progression-free and overall survival were examined. ResultsIn the multivariate analysis, PSMA-TV (primary) and PSMA-TV (WB) variables were shown to be independent negative predictors of overall survival. For the threshold value of 19.91 cm(3) obtained for PSMA-TV (primary), HR was calculated as 6.31, the 95% confidence interval (CI): 1.01-39.18, P = 0.048. For the threshold value of 1226.5 cm(3) obtained for PSMA-TV (WB) variable, HR was calculated as 58.62, the 95% CI: 2.55-1344.43, P = 0.011. In our study, SUVmax (WB) variable was found to be an independent and negative predictor of progression-free survival. For the determined threshold value of 17.74, HR was calculated as 16.24, 95% CI: 1.18-22.76, P = 0.037. ConclusionMetabolic and volumetric data obtained from Ga-68-PSMA PET/CT can be used to predict survival in de-novo high-volume mCSPC. Our results show that in ADT + Docetaxel receiving patients, a subgroup with higher PSMA-TV (WB) values have a significantly worse prognosis. This situation suggests that the high-volume disease definition in the literature may be insufficient for this group, and that Ga-68-PSMA PET/CT can play an essential role in demonstrating the heterogeneity within the group.
Öğe
Effect of embelin on inhibition of cell growth and induction of apoptosis in Acanthamoeba castellanii
(Springer, 2023) Ahmed, Usman; Ong, Seng-Kai; Khan, Khalid Mohammed; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed; Shaikh, Mohd Farooq; Alawfi, Bader Saleem
Acanthamoeba castellanii is the causative agent of fatal encephalitis and blinding keratitis. Current therapies remain a challenge, hence there is a need to search for new therapeutics. Here, we tested embelin (EMB) and silver nanoparticles doped with embelin (EMB-AgNPs) against A. castellanii. Using amoebicidal assays, the results revealed that both compounds inhibited the viability of Acanthamoeba, having an IC50 of 27.16 +/- 0.63 and 13.63 +/- 1.08 mu M, respectively, while causing minimal cytotoxicity against HaCaT cells in vitro. The findings suggest that both samples induced apoptosis through the mitochondria-mediated pathway. Differentially expressed genes analysis showed that 652 genes were uniquely expressed in treated versus untreated cells, out of which 191 were significantly regulated in the negative control vs. conjugate. Combining the analysis, seven genes (ARIH1, RAP1, H3, SDR16C5, GST, SRX1, and PFN) were highlighted as the most significant (Log2 (FC) value +/- 4) for the molecular mode of action in vitro. The KEGG analysis linked most of the genes to apoptosis, the oxidative stress signaling pathway, cytochrome P450, Rap1, and the oxytocin signaling pathways. In summary, this study provides a thorough framework for developing therapeutic agents against microbial infections using EMB and EMB-AgNPs.
Öğe
INFECTIVITY AND REPLICATION INHIBITION EFFECT OF 5-FLUOROURACIL ON HERPES SIMPLEX VIRUS TYPE-1 ASSOCIATED WITH MUTATIONS IN THYMIDINE KINASE GENE
(Soc Stiinte Farmaceutice Romania, 2022) Taskin, Mehmet Hakan; Kurucay, Hanne Nur; Kadi, Hamza; Tamer, Cuneyt; Ozan, Emre; Muftuoglu, Bahadir; Albayrak, Harun
Two pandemics over the first two decades of the 21st century have shown that viruses with epidemic and pandemic potentials constitute a major threat to human health due to the lack of effective antivirals. Developing new antivirals and treatment strategies is also as important as vaccines play a crucial role in the first line of preventing viral infections. Using base analogues that directly target viruses and understanding their action mechanisms can present essential alternative treatment strategies to combat viral diseases. The current study investigated the effects of a base analogue on herpes simplex virus type1 (HSV-1) replication in a cell culture system using the pyrimidine analogue 5-fluorouracil (FU). After that, the full-length UL-23 gene encoding thymidine kinase (TK) of HSV-1 was sequenced to detect induced mutations. The results showed a diminishing viral titre and viral load at 2 logs and 663 times, respectively, at the end of 10 consecutive passages with 5-FU. Furthermore, two mutations substitute amino acids in the non-conserved region of the TK gene, which confers drug resistance, were also identified. The current research is a feasibility study to investigate the antiviral effects of 5-FU on DNA viruses and has reinforced the fact that 5-FU can have an antiviral effect on HSV-1. However, drug resistance for viruses should not be underestimated.
Öğe
Bending, buckling and free vibration behaviours of 2D functionally graded curved beams
(Elsevier Science Inc, 2023) Karamanli, Armagan; Wattanasakulpong, Nuttawit; Lezgy-Nazargah, M.; Vo, Thuc P.
The flexural, free vibration and buckling responses of 2D-FG curved beams with various shear deformation theories are presented by using finite element model. Their material properties via both directions (length and thickness) are varied with power-law distribution. A two-node beam element satisfying C1 continuity requirement is employed to solve the problems. Various problems including isotropic, 1D- and 2D-FG curved beams are analysed and the obtained results are verified with those available in the literature. Comprehensive parameter examinations are carried out to depict the effects of gradation indexes in both directions, open angles, end conditions and aspect ratios on structural behaviours of 2D-FG curved beams.
Öğe
Task Scheduling in Cloud Computing: A Priority-Based Heuristic Approach
(Ieee-Inst Electrical Electronics Engineers Inc, 2023) Lipsa, Swati; Dash, Ranjan Kumar; Ivkovic, Nikola; Cengiz, Korhan
In this paper, a task scheduling problem for a cloud computing environment is formulated by using the M/M/n queuing model. A priority assignment algorithm is designed to employ a new data structure named the waiting time matrix to assign priority to individual tasks upon arrival. In addition to this, the waiting queue implements a unique concept based on the principle of the Fibonacci heap for extracting the task with the highest priority. This work introduces a parallel algorithm for task scheduling in which the priority assignment to task and building of heap is executed in parallel with respect to the non-preemptive and preemptive nature of tasks. The proposed work is illustrated in a step-by-step manner with an appropriate number of tasks. The performance of the proposed model is compared in terms of overall waiting time and CPU time against some existing techniques like BATS, IDEA, and BATS+BAR to determine the efficacy of our proposed algorithms. Additionally, three distinct scenarios have been considered to demonstrate the competency of the task scheduling method in handling tasks with different priorities. Furthermore, the task scheduling algorithm is also applied in a dynamic cloud computing environment.