https://hdl.handle.net/20.500.12294/434 Biyomedikal Mühendisliği Bölümüne ait makaleler bu koleksiyonda listelenir. Fri, 22 May 2026 20:54:51 GMT 2026-05-22T20:54:51Z https://hdl.handle.net/20.500.12294/4139 Adsorption and desorption of hydroxychloroquine onto sulphur doped graphene powders as a potential drug for COVID-19 Acar, Tayfun; Arvas, Melih Besir; Arvas, Busra; Ucar, Burcu; Sahin, Yucel Hydroxychloroquine (HCQ) is a very substantial drug active substance that was approved for emergency use by the FDA during the peak of the COVID-19 pandemic due to its potent antiviral properties. In this study, adsorption and desorption of hydroxychloroquine on sulfur (S)-doped graphene powders were investigated. While the adsorption experiments were carried out in the environment of distilled water (pH 5.0-6.0), HEPES buffer (pH 7.6), and Tris.HCl buffer (pH 8.0) the desorption studies were performed in distilled water. The HCQ adsorbed S-doped graphene powders were characterized by UV-Vis, FT-IR, XRD, BET and TEM techniques. According to UV-Vis measurements, the adsorption efficiency in the HEPES buffer medium at pH 7.6 was the highest (68.72% for H3 (HCQ adsorption with SGr3 graphene in HEPES medium)). FT-IR and XRD analyses confirmed the presence of HCQ on the graphene powders' surface. While morphological changes on the surfaces of graphene powders were imaged by TEM, BET surface area changes proved the HCQ adsorption. The in vitro toxicity of the developed H3 was found to be lower than that of HCQ alone on the L929 cell line. These fundamental findings of the surface interaction between HCQ and graphene are precious for the design and optimization of a targeted drug based on this molecule and material. The adsorption/desorption features of HCQ onto graphene-based carrier systems which in particular doped with sulfur from functional metals have been investigated for the first time. Mon, 01 Jan 2024 00:00:00 GMT https://hdl.handle.net/20.500.12294/4139 2024-01-01T00:00:00Z https://hdl.handle.net/20.500.12294/4122 High antibiotic resistance rates in Helicobacter pylori strains in Turkey over 20 years Sarikaya, Burak; Cetinkaya, Riza Aytac; Ozyigitoglu, Derya; Isik, Sinem Akkaya; Kaplan, Mustafa; Kirkik, Duygu; Gorenek, Levent Objective Helicobacter pylori (Hp) eradication therapy is crucial for preventing the development of gastritis, peptic ulcers, and gastric cancer. An increase in resistance against antibiotics used in the eradication of Hp is remarkable. This meta-analysis aims to examine the resistance rates of Hp strains isolated in Turkey over the last 20 years against clarithromycin (CLR), metronidazole (MTZ), levofloxacin (LVX), tetracycline (TET), and amoxicillin (AMX) antibiotics. Basic methods Literature search was carried out in electronic databases, by searching articles published in Turkish and English with the keywords 'helicobacter pylori' or 'Hp' and 'antibiotic resistance' and 'Turkey'. That meta-analysis was carried out using random-effect model. First, the 20-year period data between 2002 and 2021 in Turkey were planned to be analyzed. As a second stage, the period between 2002 and 2011 was classified as Group 1, and the period between 2012 and 2021 as Group 2 for analysis, with the objective of revealing the 10-year temporal variation in antibiotic resistance rates. Main results In gastric biopsy specimens, 34 data from 29 studies were included in the analysis. Between 2002-2021, CLR resistance rate was 30.9% (95% CI: 25.9-36.2) in 2615 Hp strains. Specifically, in Group 1, the CLR resistance rate was 31% in 1912 strains, and in Group 2, it was 30.7% in 703 strains. The MTZ resistance rate was found to be 31.9% (95% CI: 19.8-45.4) in 789 strains, with rates of 21.5% in Group 1 and 46.6% in Group 2. The overall LVX resistance rate was 25.6%, with rates of 26.9% in Group 1 and 24.8% in Group 2. The 20-year TET resistance rate was 0.8%, with 1.50% in Group 1 and 0.2% in Group 2. The overall AMX resistance rate was 2.9%, 3.8% between 2002-2011, and 1.4% between 2012-2021. Principal conclusion Hp strains in Turkey exhibit high resistance rates due to frequent use of CLR, MTZ, and LVX antibiotics. However, a significant decrease has been observed in TET and AMX resistance to Hp in the last 10 years. Considering the CLR resistance rate surpasses 20%, we suggest reconsidering the use of conventional triple drug therapy as a first-line treatment. Instead, we recommend bismuth-containing quadruple therapy or sequential therapies (without bismuth) for first-line treatment, given the lower rates of TET and AMX resistance. Regimens containing a combination of AMX, CLR, and MTZ should be given priority in second-line therapy. Finally, in centers offering culture and antibiogram opportunities, regulating the Hp eradication treatment based on the antibiogram results is obviously more appropriate. Mon, 01 Jan 2024 00:00:00 GMT https://hdl.handle.net/20.500.12294/4122 2024-01-01T00:00:00Z https://hdl.handle.net/20.500.12294/4093 Effects of MWCNT and Sodium Dodecyl Sulfate (SDS) contents on the electrical conductivity and sensor properties of thermoplastic polyurethane nanosurfaces Inan, Rusen; Usta, Ismail; Sahin, Yesim Muge Recently, strain sensors have significant areas of usage with their strain, stretching and wearable features for various applications such as personal health monitoring, joint movement detection, robotics, etc. To achieve this, various studies are conducted to optimize the production of MWCNT-based nanocomposites. In the present study, a total of 12 solutions were formulated by introducing Multi -Walled Carbon Nanotubes (MWCNT) and Sodium Dodecyl Sulfate (SDS) at different concentrations and ratios into the Thermoplastic Polyurethane (TPU) solution, and then nanocomposite surfaces were produced from these solutions through an electrospinning process. These samples were subjected to resistance changes due to elongation, gauge factor changes due to elongation to evaluate the sensor property and cycle tests to evaluate the sustainability of the sensor feature. According to the results, the best sensor properties were obtained in the samples with SDS added at a rate of 1/20 (MWCNT:SDS) for 0.3 MWCNT and 0.5 MWCNT; on the other hand 1/26 weight ratio of MWCNT:SDS for 0.7 MWCNT. Mon, 01 Jan 2024 00:00:00 GMT https://hdl.handle.net/20.500.12294/4093 2024-01-01T00:00:00Z https://hdl.handle.net/20.500.12294/4075 Advanced Bioresin Formulation for 3D-Printed Bone Scaffolds Sakarya, Deniz; Zorlu, Tolga; Yucel, Sevil; Sahin, Yesim Muge; Ozarslan, Ali Can In bone tissue engineering, scaffold attributes such as pore dimensions and mechanical strength are crucial. This study synthesized polycaprolactone dimethacrylate (PCLDMA) from polycaprolactone (PCL), incorporating epichlorohydrin (Epi-PCL) and methacryloyl chloride (Meth-Cl). PCLDMA was blended with polylactic acid (p-PLA) to 3D-print bone scaffolds using stereolithography (SLA). Analytical techniques included nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and compression testing. Degradation kinetics and cell viability were investigated using human osteoblast (HOB) cells. Findings revealed PCLDMA/p-PLA composite scaffold superiority over the original polymers. Notably, PCLDMA-60 (60% PCLDMA, 40% p-PLA) displayed optimal properties. Compressive strength varied from 0.019 to 16.185 MPa, porosity from 2% to 50%, and degradation rates from 0% to 0.4% over three days. Cell viability assays affirmed biocompatibility across various PCLDMA ratios. In conclusion, PCLDMA/p-PLA composite scaffolds, particularly PCLDMA-60, show great potential in bone tissue engineering. © 2024 by the authors. Mon, 01 Jan 2024 00:00:00 GMT https://hdl.handle.net/20.500.12294/4075 2024-01-01T00:00:00Z