210 results
Search Results
Now showing 1 - 10 of 210
Article Citation - WoS: 96Citation - Scopus: 100Effect of Progesterone on Dppc Membrane: Evidence for Lateral Phase Separation and Inverse Action in Lipid Dynamics(Elsevier Science inc, 2005) Korkmaz, F; Severcan, FInteractions of progesterone with zwitterionic dipalmitoyl phosphatidylcholine (DPPC) triultilamellar liposomes were investigated as a function of temperature and progesterone concentration by using three non-invasive techniques namely Fourier transform infrared spectroscopy, turbidity at 440 nm, and differential scanning calorimetry. The results reveal that progesterone changes the physical properties of DPPC bilayers by decreasing the main phase-transition temperature, abolishing the pre-transition, broadening the phase-transition profile, disordering the system both in gel and liquid crystalline phase, increasing the dynamics at low concentrations whereas stabilizing the membrane at high concentrations, and inducing phase separation. Progesterone does not change the hydration of the C=O groups, while it strengthens the hydrogen bonding between the PO (2) over bar groups of lipids and the water molecules around. (c) 2005 Elsevier Inc. All rights reserved.Article Citation - WoS: 8Citation - Scopus: 8Surface Microbiota and Associated Staphylococci of Houseflies (musca Domestica) Collected From Different Environmental Sources(Academic Press Ltd- Elsevier Science Ltd, 2022) Sudagidan, Mert; Ozalp, Veli Cengiz; Can, Ozge; Eligul, Hakan; Yurt, Mediha Nur Zafer; Tasbasi, Behiye Busra; Kocak, OnerHouseflies (Musca domestica) are important mechanical vectors for the transmission of pathogenic microorganisms. In this study, 129 houseflies (69 males and 60 females) were collected from 10 different environmental sources and a laboratory population was used. The surface microbiota of houseflies was identified by NextGeneration Sequencing. Staphylococci from the surfaces of houseflies were selectively isolated and their virulence genes, antibiotic susceptibilities, biofilm formation, and clonal relatedness were determined. Metagenomic analysis results demonstrated that Staphylococcus, Bacillus, and Enterococcus were mostly present on the surface of houseflies at the genus level. Additionally, the isolated 32 staphylococcal strains were identified as Staphylococcus sciuri (n = 11), S. saprophyticus (n = 9), S. arlettae (n = 6), S. xylosus (n = 4), S. epidermidis (n = 1) and S. gallinarum (n = 1). tetK, tetM, tetL, ermC, msrAB, and aad6 genes were found to carry by some of the staphylococcal strains. The strains were mostly resistant to oxacillin, penicillin, and erythromycin and three strains were multi-drug resistant. There was a statistical difference between housefly collection places and antibiotic resistance of isolated staphylococci to penicillin G, gentamicin, and erythromycin (p < 0.05). Biofilm test showed that 17 strains were strong biofilm formers, and it plays important role in the transmission of these bacteria on the surface of houseflies. Staphylococcal strains showed extracellular proteolytic and lipolytic activity in 31 and 12 strains, respectively. Closely related species were found in PFGE analysis from different environmental sources. By this study, surface microbiota and carriage of pathogenic staphylococci on the surfaces of houseflies and their virulence properties were elucidated.Article Citation - WoS: 5The Evaluation of Serum Endocan, Interleukin-6, and Crp Levels Following Sleeve Gastrectomy(Dove Medical Press Ltd, 2023) Sariyildiz, Gulcin Turkmen; Demir, Canan Cicek; Demir, Mehmet Emin; Arslan, Aykut Ilker; Banli, Oktay; Dursun, Ali DoganBackground: The excessive accumulation of fat tissue in obesity is the source of chronic low-level inflammation and causes future dysmetabolic and cardiovascular disorders. Removal of this excessive fat tissue with the aid of bariatric surgery (BS) techniques, such as sleeve gastrectomy, may reverse adverse inflammatory outcomes. The aim of this study is to investigate the impact of sleeve gastrectomy on inflammatory markers, specifically endocan, IL-6, and CRP, in individuals with obesity.Methods: Thirty-two patients with class 3 obesity and class 2 obesity + comorbidities were enrolled in the study. Clinical characteristics including age, comorbidity, body mass index (BMI), waist, and hip circumferences of the participants were noted before and 3 months after sleeve gastrectomy. Blood samples were collected during those periods to assess biochemical features such as serum endocan, interleukin-6 (IL-6), C-reactive peptide, fasting insulin, glycosylated hemoglobin A1c levels, and lipid panel. A statistical package program was used for the analysis of those parameters, and p<0.05 was accepted as significant at a 95.0% confidence interval.Results: BMI reduced from 43.55 +/- 6.78 to 36.16 +/- 6.14 kg/m(2) within 3 months following BS (p<0.001). Preoperative serum endocan, IL-6, and CRP levels were correlated with BMI, and in line with BMI reduction, their serum levels decreased after BS (p<0.05). HOMA-IR also reduced after BS, and both in the pre and post-BS periods correlated with BMI, IL-6, endocan, and CRP levels (p<0.05). The mean total body weight loss was 20.4% within 3 months post-BS.Conclusion: BS techniques are effective in weight loss and reversing the inflammatory processes caused by obesity. Serum endocan, IL-6, and CRP levels are promising markers for describing obesity-related inflammation and objectively checking the alleviation of inflammation following BS.Correction Correction: Evaluating Anterior Segment Stability and Corneal Endothelium After Prolene Gonioscopy Assisted Transluminal Trabeculotomy (GATT) in Open-Angle Glaucoma(Springer, 2025) Aribas, Yavuz Kemal; Aktas, Zeynep; Ertop, MestanArticle Transcatheter Aortic Valve Implantation in Nonagenarians: A Comparative Analysis of Baseline Characteristics and 1-Year Outcomes(MDPI, 2025) Guney, Murat Can; Bozkurt, EnginBackground: Transcatheter aortic valve implantation (TAVI) is increasingly used in elderly patients with severe aortic stenosis, yet data on nonagenarians remain limited. This study aimed to compare clinical characteristics and outcomes of patients aged >= 90 years with those aged <90 years undergoing TAVI. Methods: We retrospectively analyzed 620 patients who underwent transfemoral TAVI. Patients were divided into two groups: <90 years (n = 545) and >= 90 years (n = 75). Baseline clinical, procedural, and outcome data were compared. Results: Nonagenarians had lower body mass index (BMI) and a lower prevalence of comorbidities such as diabetes, hyperlipidemia, and prior coronary artery bypass grafting CABG (all p < 0.05). All-cause mortality was higher in nonagenarians at 1 month (8.0% vs. 5.5%, p = 0.425), 6 months (9.3% vs. 7.9%, p = 0.838), and 1 year (21.3% vs. 16.7%, p = 0.405), though these differences were not statistically significant. In-hospital stroke occurred more frequently in patients >= 90 years (6.7% vs. 2.2%, p = 0.044). Conclusions: Despite a higher rate of in-hospital stroke, nonagenarians undergoing TAVI had comparable mortality outcomes to younger patients. These findings support the feasibility of TAVI in selected very elderly patients, while highlighting the need for tailored stroke prevention strategies. Trial Registration: The trial is retrospectively registered, and a clinical trial number is not applicable.Article Citation - WoS: 19Citation - Scopus: 24A Novel Hybrid Machine Learning Based System To Classify Shoulder Implant Manufacturers(Mdpi, 2022) Sivari, Esra; Guzel, Mehmet Serdar; Bostanci, Erkan; Mishra, AlokIt is necessary to know the manufacturer and model of a previously implanted shoulder prosthesis before performing Total Shoulder Arthroplasty operations, which may need to be performed repeatedly in accordance with the need for repair or replacement. In cases where the patient's previous records cannot be found, where the records are not clear, or the surgery was conducted abroad, the specialist should identify the implant manufacturer and model during preoperative X-ray controls. In this study, an auxiliary expert system is proposed for classifying manufacturers of shoulder implants on the basis of X-ray images that is automated, objective, and based on hybrid machine learning models. In the proposed system, ten different hybrid models consisting of a combination of deep learning and machine learning algorithms were created and statistically tested. According to the experimental results, an accuracy of 95.07% was achieved using the DenseNet201 + Logistic Regression model, one of the proposed hybrid machine learning models (p < 0.05). The proposed hybrid machine learning algorithms achieve the goal of low cost and high performance compared to other studies in the literature. The results lead the authors to believe that the proposed system could be used in hospitals as an automatic and objective system for assisting orthopedists in the rapid and effective determination of shoulder implant types before performing revision surgery.Article Investigation of Sars-Cov Antibody Levels After Covid-19 Vaccine in Chronic Hepatitis B Patients(Aepress Sro, 2024) Kinikli, Sami; Afsar, Fatma Elcin; Dursun, Ali Dogan; Aksoy, Altan; Karahan, Gizem; Cesur, Salih; Urtimur, UfukAIM: The aim was to compare SARS-CoV-2 IgG antibody levels in chronic hepatitis B patients and healthcare personnel selected as the control group and to determine factors such as age, gender, vaccine type, and number of vaccines that may affect the antibody levels. MATERIALS AND METHODS: 87 chronic hepatitis B (CHB) patients followed in Ankara Training and Research Hospital Infectious Diseases Clinic and Mamak State Hospital Infectious Diseases outpatient clinic and 89 healthcare personnel selected as the control group were included in the study. SARS-CoV-2 IgG antibody levels in the serum samples of patients and healthcare personnel who received the COVID-19 vaccine were studied with the ELISA method in the Microbiology Laboratory of Ankara Training and Research Hospital, using a commercial ELISA kit (Abbott, USA) in line with the recommendations of the manufacturer. In the study, SARS-CoV-2 IgG levels were compared in CHB patients and healthcare personnel. In addition, the relationship between SARS-CoV-2 antibody level, gender, average age, natural history of the disease, number of vaccinations, vaccine type (Coronavac TM vaccine alone, BNT162b2 vaccine alone or Coronavac TM and BNT162b2 vaccine (heterologous vaccination)), treatment duration of CHB was investigated. Statistical analyses were made in the SPSS program. A value of p <= 0.05 was considered statistically significant. FINDINGS: A total of 167 people, including 87 CKD patients and 80 healthcare personnel as the control group, were included in the study. SARS-CoV-2 IgG antibody levels were detected above the cut-off level in the entire study group, regardless of the vaccine type. No difference was detected in SARS-CoV-2 IgG titers after COVID-19 vaccination between CHB patients and healthcare personnel. There was a statistically significant difference in SARS-CoV-2 IgG antibody levels among individuals participating in the study according to vaccine types. Compared to those who received Coronavac TM vaccine alone, the average SARS-CoV-2 IgG level was found to be statistically significantly higher in those who received BNT162b2 vaccine alone or heterologous vaccination with Coronavac TM + BNT162b2 vaccine. There was no difference between the groups in terms of age, gender, number of vaccinations, natural transmission of the disease, and duration of antiviral therapy in the CHD patient group. CONCLUSION: As a result, SARS-CoV-2 IgG antibody levels above the cut-off value were achieved with Coronavac TM and BNT162b2 vaccines in both CHD patients and healthy control groups. however, both CHD patients and healthcare personnel had higher antibody levels than those who received BNT162b2 alone or those who received heterologous vaccination had higher antibody levels than those with Coronavac TM alone. Therefore, if there are no contraindications, BNT162b2 vaccine may be preferred in CHB and health personnel (Tab. 2, Ref. 14) .Article Citation - WoS: 5Citation - Scopus: 5Further Development of Polyepichlorohydrin Based Anion Exchange Membranes for Reverse Electrodialysis by Tuning Cast Solution Properties(Mdpi, 2022) Eti, Mine; Cihanoglu, Aydin; Guler, Enver; Gomez-Coma, Lucia; Altiok, Esra; Arda, Muserref; Kabay, NalanRecently, there have been several studies done regarding anion exchange membranes (AEMs) based on polyepichlorohydrin (PECH), an attractive polymer enabling safe membrane fabrication due to its inherent chloromethyl groups. However, there are still undiscovered properties of these membranes emerging from different compositions of cast solutions. Thus, it is vital to explore new membrane properties for sustainable energy generation by reverse electrodialysis (RED). In this study, the cast solution composition was easily tuned by varying the ratio of active polymer (i.e., blend ratio) and quaternary agent (i.e., excess diamine ratio) in the range of 1.07-2.00, and 1.00-4.00, respectively. The membrane synthesized with excess diamine ratio of 4.00 and blend ratio of 1.07 provided the best results in terms of ion exchange capacity, 3.47 mmol/g, with satisfactory conductive properties (area resistance: 2.4 omega center dot cm(2), electrical conductivity: 6.44 mS/cm) and high hydrophilicity. RED tests were performed by AEMs coupled with the commercially available Neosepta CMX cation exchange membrane (CEMs).Article Citation - WoS: 8Citation - Scopus: 8Complex Nodal Structure Phonons Formed by Open and Closed Nodal Lines in Coass and Na2cup Solids(Royal Soc Chemistry, 2022) Ding, Guangqian; Sun, Tingting; Surucu, Gokhan; Surucu, Ozge; Gencer, Aysenur; Wang, XiaotianTopological phononic states with nodal lines not only have updated our knowledge of the phases of matter in a fundamental way, but also have become a major frontier research direction in condensed matter physics. From a mathematical perspective, nodal line phonons can be divided into open and closed types. The present attempt is a report on the coexistence of such open and closed nodal line phonons in two realistic solids, CoAsS and Na2CuP, based on first-principles calculations. Furthermore, it is shown that the closed and the open nodal line states in CoAsS and Na2CuP have touching points and can form a complex nodal structure phonon in a momentum space. Due to the topologically non-trivial behavior of the complex nodal structure in both phonons, evident phononic surface states occur in the projected surfaces of both materials. In this way, these states, arising from the projected crossing points, can benefit experimental detection in follow-up studies. It has been stated that the open and closed nodal line states are formed by the crossings of two phonon branches and, hence, these two types of nodal line phonons are coupled with each other. The results obtained here could be considered as a breakthrough in clearly demonstrating the coexistence of the open and closed nodal line states in phonons and, for this reason, may inspire researchers seeking materials with such topological states in other bosons, such as photons.Article Citation - WoS: 2Citation - Scopus: 2Assessment of Anticancer Effects of Aloe Vera on 3D Liver Tumor Spheroids in a Microfluidic Platform(Wiley, 2025) Tevlek, Atakan; Kibar, Gunes; Cetin, BarbarosThe search for effective anticancer therapies has increasingly focused on natural compounds like Aloe vera, renowned for its therapeutic properties. This study investigates the anticancer properties of Aloe vera on 3D liver tumor spheroids via a PDMS-based microfluidic device, providing a more physiologically realistic model compared to traditional 2D cultures. HepG2 cells were cultivated to generate 3D spheroids on-chip, thereafter subjected to different concentrations of Aloe vera and the chemotherapeutic drug Doxorubicin to evaluate cytotoxic effects. The microfluidic system, validated by COMSOL simulations, facilitated continuous perfusion and real-time assessment of cell viability over a duration of 10 days. The results indicated that Aloe vera markedly diminished cell viability by triggering apoptosis at concentrations over 12.5 mg/mL. IC50 values were determined at 72 h: 25 +/- 0.10 mg/mL for Aloe vera and 5.47 +/- 0.03 mu g/mL for Doxorubicin in 2D cultures, but in 3D cultures, the IC50 values were 31.25 +/- 0.14 mg/mL for Aloe vera and 8.33 +/- 0.05 mu g/mL for Doxorubicin. This study underscores the promise of Aloe vera as a natural anticancer agent and illustrates the efficacy of microfluidic platforms for enhanced drug screening and customized medicine applications.
