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Article Citation - WoS: 10Citation - Scopus: 12Detection of Viruses by Probe-Gated Silica Nanoparticles Directly From Swab Samples(Elsevier, 2022) Tuna, Bilge Guvenc; Durdabak, Dilara Buse; Ercan, Meltem Kazak; Dogan, Soner; Kavruk, Murat; Dursun, Ali Dogan; Ozalp, Veli CengizViral infection has been one of the major health issues for human life. The real-time reverse transcription polymerase chain reaction (RT-PCR)-based detection has primarily been used for virus detection as a highly reliable procedure. However, it is a relatively long and multi-stage process. In addition, required skilled personnel and complex instrumentation presents difficulties in large scale monitoring efforts. Therefore, we report here a direct and fast detection method for CoV-2 genome as applied in the nose-throat swab samples without any further processing. The detection principle is based on fluorescein-loaded mesoporous silica nanoparticles capped by specific gene sequences probes immobilized on the surface of the nanoparticles. Upon hybridization with the target viral genome, the fluorescein molecules were released from the mesopores. Testing with synthetic oligonucleotides, the NSP12 gene-based detection resulted in a strong signal. Target detection time could be optimized to 15 min and the limit of detection was 1.4 RFU with 84% sensitivity with clinical samples (n = 43).Article Citation - WoS: 16Citation - Scopus: 19A Pumpless Monolayer Microfluidic Device Based on Mesenchymal Stem Cell-Conditioned Medium Promotes Neonatal Mouse in Vitro Spermatogenesis(Bmc, 2023) Onen, Selin; Atik, Ali Can; Gizer, Merve; Kose, Sevil; Yaman, Onder; Kulah, Haluk; Korkusuz, PetekBackgroundChildhood cancer treatment-induced gonadotoxicity causes permanent infertility/sub-infertility in nearly half of males. The current clinical and experimental approaches are limited to cryopreservation of prepubertal testicular strips and in vitro spermatogenesis which are inadequate to achieve the expanded spermatogonial stem/progenitor cells and spermatogenesis in vitro. Recently, we reported the supportive effect of bone marrow-derived mesenchymal cell co-culture which is inadequate after 14 days of culture in static conditions in prepubertal mouse testis due to lack of microvascular flow and diffusion. Therefore, we generated a novel, pumpless, single polydimethylsiloxane-layered testis-on-chip platform providing a continuous and stabilized microfluidic flow and real-time cellular paracrine contribution of allogeneic bone marrow-derived mesenchymal stem cells.MethodsWe aimed to evaluate the efficacy of this new setup in terms of self-renewal of stem/progenitor cells, spermatogenesis and structural and functional maturation of seminiferous tubules in vitro by measuring the number of undifferentiated and differentiating spermatogonia, spermatocytes, spermatids and tubular growth by histochemical, immunohistochemical, flow cytometric and chromatographic techniques.ResultsBone marrow-derived mesenchymal stem cell-based testis-on-chip platform supported the maintenance of SALL4(+) and PLZF(+) spermatogonial stem/progenitor cells, for 42 days. The new setup improved in vitro spermatogenesis in terms of c-Kit(+) differentiating spermatogonia, VASA(+) total germ cells, the meiotic cells including spermatocytes and spermatids and testicular maturation by increasing testosterone concentration and improved tubular growth for 42 days in comparison with hanging drop and non-mesenchymal stem cell control.ConclusionsFuture fertility preservation for male pediatric cancer survivors depends on the protection/expansion of spermatogonial stem/progenitor cell pool and induction of in vitro spermatogenesis. Our findings demonstrate that a novel bone marrow-derived mesenchymal stem cell-based microfluidic testis-on-chip device supporting the maintenance of stem cells and spermatogenesis in prepubertal mice in vitro. This new, cell therapy-based microfluidic platform may contribute to a safe, precision-based cell and tissue banking protocols for prepubertal fertility restoration in future.Article On the Resolvent of the Laplace-Beltrami Operator in Hyperbolic Space(Cambridge Univ Press, 2015) Guseinov, Gusein Sh.In this paper, a detailed description of the resolvent of the Laplace-Beltrami operator in n-dimensional hyperbolic space is given. The resolvent is an integral operator with the kernel (Green's function) being a solution of a hypergeometric differential equation. Asymptotic analysis of the solution of this equation is carried out.Article Citation - WoS: 1Citation - Scopus: 1Early Posterior Corneal Changes and Belin/Ambrosio Scores Following Photorefractive Keratectomy: a Pentacam Study(Springer int Publ Ag, 2025) Yakar, Konuralp; Alacamli, Goeksu; Ozgur, GoekhanIntroduction: To evaluate early postoperative changes in the posterior corneal surface, anterior chamber parameters, and Belin/Ambrosio Enhanced Ectasia Display (BAD) scores following photorefractive keratectomy (PRK) using Pentacam tomography. Methods: This observational study included 102 eyes of 51 patients (mean age 28.43 +/- 6.27 years) undergoing alcohol-assisted PRK for myopia and/or astigmatism. Preoperative and 1-month postoperative assessments were performed using the Pentacam system, measuring, anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness, posterior keratometry, posterior elevation, and BAD scores. PRK was conducted with a WaveLight (R) EX 500 excimer laser, followed by mitomycin-C application. Statistical analysis utilized paired t-tests and Pearson's correlation. Results: At 1 month post-PRK, ACV significantly decreased (p < 0.01), while ACD reduction was not significant (p = 0.40). Posterior keratometry (K1, K2, Kmean) and astigmatism decreased (p < 0.01), with a mean posterior elevation increase of -2.50 +/- 2.94 mu m (p < 0.01). A weak negative correlation was observed between maximum posterior elevation difference and ablation depth (p = 0.03, r = -0.20) and ablation depth/preoperative pachymetry ratio (p = 0.03, r = -0.20). BAD-D scores (Dp, Dt, Da, total D) significantly increased (p < 0.01), except for Df (p = 0.41). No correlation was found with preoperative pachymetry or residual stroma. Conclusions: PRK induces minimal posterior corneal protrusion and BAD score changes at 1 month, potentially mimicking early ectasia. Multimodal testing is advised for accurate ectasia detection. Larger, longer-term studies are needed to validate these findings.Article Citation - Scopus: 16Fixed Point Theory for the Α-Admissible Meir-Keeler Type Set Contractions Having Kkm* Property on Almost Convex Sets(Natural Sciences Publishing, 2017) Chen,C.-M.; Abkar,A.; Ghods,S.; Karapinar,E.The purpose of this paper is to study fixed points for the KKM* family satisfying the a-admissible Meir-Keeler-type set contractions with respect to the set measure σp of noncompactness in the context of Hausdorff topological vector spaces. Our results generalize or improve many recent fixed point theorems for the KKM family in the literature. Subject class: [2000]46T99,47H10, 54C60, 54H25, 55M20. © 2017 NSP.Conference Object Multispectral Plasmonic Structures Using Native Aluminum Oxide and Aluminum(Optica Publishing Group (formerly OSA), 2017) Ayas,S.; Bakan,G.; Dana,A.We report the use of native aluminum oxide to fabricate periodic metal-insulator-metal resonators with simultaneous resonances in the visible and IR wavelengths. The cavity size is in the order of λ3/25000 in the NIR. © 2017 OSA.Article Citation - WoS: 8Citation - Scopus: 9Effect of Alpha-1-Adrenoceptor Blocker on Cytosolic Enzyme Targets for Potential use in Cancer Chemotherapy(Asian Network Scientific information-ansinet, 2012) Isgor, Belgin S.; Isgor, Yasemin G.Doxazosin is one of the quinazoline-based alpha 1-adrenergic receptor antagonists in clinical use for the treatment of hypertension and benign prostate hyperplasia. Doxazosin-induced cytotoxicity studies, resulted in growth inhibition and apoptosis, show its potential therapeutic benefits for several forms of cancers. These effects on cells occur as adrenoceptor-independent mechanisms, as observed with other quinazoline family of alpha-1 blockers. Moreover, Doxazosin induced apoptosis is associated with pathways, including EGFR, NF-kappa beta and TGF-beta signaling which typically engage Src as a central signaling component. Recent evidences show that glutathione transferases, may also contribute to these signaling events, through the kinases that share signaling pathways with Src, responsible for the regulation of transferase activity. In addition, the overactive glutathione transferases are related with anticancer drug resistance, as well as cancer development. Therefore, in the present study, the anticancer potential of Doxazosin was investigated by in vitro enzyme assays that were used to develop full dose-response profiles of drug at varying doses. The drug dose that exerts 50% inhibition of enzyme activity is defined as IC50 value and determined through the nonlinear regression analysis of dose-response data. The IC50 values determined for Src kinase, total protein tyrosine kinase, cytosolic total Src family kinase and total glutathione transferase enzymes were within nanomolar to low micromolar range. These results suggest that Doxazosin may be used to improve multifunctional therapeutic formulations to provide reduced drug resistance and enhanced cytotoxicity at target tissues.Article Citation - WoS: 1Citation - Scopus: 2Software Evolution in Turkey(Univ Osijek, Tech Fac, 2016) Mishra, Alok; Yazici, Ali; Cetin, SemihAccording to a recent Gartner report, Turkey is now to be considered in one of the world's outsourcing destinations since it has secured its place in the list of top 30 countries for Information Technology ( IT), and offshore services. In the last decade, the country has made excellent progress in the software sector, and this is reflected in the rise of its exports to many countries. In this article, we present an overview of advancement of Turkey's software sector, including current trends in software process, testing, quality, and the adoption of agile methods along with techno parks and incentives provided by the government.Article Citation - WoS: 20Citation - Scopus: 49Coupled Coincidence Points in Partially Ordered Cone Metric Spaces With a c-distance(Hindawi Ltd, 2012) Shatanawi, Wasfi; Karapinar, Erdal; Aydi, HassenCho et al. (2012) proved some coupled fixed point theorems in partially ordered cone metric spaces by using the concept of a c-distance in cone metric spaces. In this paper, we prove some coincidence point theorems in partially ordered cone metric spaces by using the notion of a c-distance. Our results generalize several well-known comparable results in the literature. Also, we introduce an example to support the usability of our results.Article Performance Evaluation of Empirical Path Loss Models for a Linear Wireless Sensor Network Deployment in Suburban and Rural Environments(2020) Dalveren, Yaser; Kara, AliThis article presents a preliminary propagation study on the accuracy of empirical path loss models for efficient planning and deployment of a linear wireless sensor network (LWSN) based on long range (LoRa) enabled sensor nodes in suburban and rural environments. Real-world deployment of such network requires accurate path loss modelling to estimate the network coverage and performance. Although several models have been studied in the literature to predict the path loss for LoRa links, the assessment of empirical path loss models within the context of low-height peer to peer configured system has not been provided yet. Therefore, this study aims at providing a performance evaluation of well-known empirical path loss models including the Log-distance, Okumura, Hata, and COST-231 Hata model in a peer to peer configured system where the sensor nodes are deployed at the same low heights. To this end, firstly, measurement campaigns are carried out in suburban and rural environments by utilizing LoRa enabled sensor nodes operating at 868 MHz band. The measured received signal strength values are then compared with the predicted values to assess the prediction accuracy of the models. The results achieved from this study show that the Okumura model has higher accuracy
