Fen Edebiyat Fakültesi / Faculty of Letters and Science

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    Sustainable Biomaterials For Tissue Engineering: Electrospun Polycaprolactone Fibers Enriched With Freshwater Snail Calcium Carbonate And Waste Human Hair Keratin
    (Başkent Üniversitesi Fen Edebiyat Fakültesi, 2024-06-08) Erdemli, Ozge; Yilmaz, Bengi; Saran, Irem Goksu; Serin, Erdal
    This study focuses on developing a sustainable and biocompatible polycaprolactone (PCL)-based scaffold for bone tissue engineering through electrospinning, utilizing calcium carbonate (CaCO3) from Pomacea canaliculata shells and keratin from human hair, known for stimulating bone regeneration. The isolated CaCO3 has been identified to demonstrate two polymorphs, vaterite and calcite, as determined by X-ray diffraction. The isolation of keratin from human hair was confirmed through sodium dodecyl sulfate polyacrylamide gel electrophoresis and Fourier transform infrared spectroscopy analysis, revealing the presence of alpha-keratin structures around 45-50 kDa and beta-keratin structures around 55-60 kDa. According to scanning electron microscope observations, the addition of keratin to PCL fibers reduced their diameter from 457 +/- 345 to 371 +/- 103 nm. Further addition of calcium carbonate led to a mean diameter of 258 +/- 76 nm. The melting temperature of PCL fibers containing keratin and CaCO3 was determined to be 76.17 degrees C via differential scanning calorimetry, while thermogravimetric analysis, conducted at temperatures up to 600 degrees C, revealed a remaining ash content of 9.59%. Calcium phosphate accumulation was observed to initiate on PCL fibers containing keratin and CaCO3 following a 7-day exposure to simulated body fluid. The fibers exhibit cytocompatibility, showing no toxicity while supporting the growth and proliferation of Saos-2 osteosarcoma cells. The results suggest that the innovative incorporation of keratin and CaCO3 into PCL nanofibers could serve as a bioactive matrix compared to pure PCL matrices, thereby offering enhanced potential for bone tissue engineering applications. (c) 2024 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Electrospun PCL fibers with human hair keratin and snail shell calcium carbonate were developed, analyzed via SEM, FTIR, DSC and TGA and tested for bioactivity and in vitro cell viability. image
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    Residual Protein Analysis By SDS-PAGE In Clinically Manufactured BM-MSC Products
    (Başkent Üniversitesi Fen Edebiyat Fakültesi, 2024-05-11) Kilic, Pelin; Karabudak, Sema; Cosar, Begum; Savran, Busra Nigar; Yalcin, Merve
    Residual substances that are considered hazardous to the recipient must be removed from final cellular therapeutic products manufactured for clinical purposes. In doing so, quality rules determined by competent authorities (CAs) for the clinical use of tissue- and cell-based products can be met. In our study, we carried out residual substance analyses, and purity determination studies of trypsin and trypsin inhibitor in clinically manufactured bone marrow-derived mesenchymal stromal/stem cell products, using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method. Despite being a semiquantitative method, SDS-PAGE has several benefits over other methods for protein analysis, such as simplicity, convenience of use, and affordability. Due to its convenience and adaptability, SDS-PAGE is still a commonly used method in many laboratories, despite its limits in dynamic range and quantitative precision. Our goal in this work was to show that SDS-PAGE may be used effectively for protein measurement, especially where practicality and affordability are the major factors. The results of our study suggest a validated method to guide tissue and cell manufacturing sites for making use of an agreeable, accessible, and cost-effective method for residual substance analyses in clinically manufactured cellular therapies.
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    What Drives Mating Effort: Fear of Singlehood, Relationship Status, and Self-Esteem
    (Başkent Üniversitesi Fen Edebiyat Fakültesi, 2024-04-27) Apostolou, Menelaos; Tekes, Burcu; Kagialis, Antonios
    Purpose Attracting and maintaining a romantic partner requires considerable effort. In the current study, we aimed to test the hypothesis that fear of singlehood is a primary factor driving individuals to allocate scarce resources in the mating domain.Methods We conducted a close-ended survey with a sample of 990 Greek and Turkish-speaking participants.Results We found that that a stronger fear of singlehood was associated with higher mating effort. Moreover, voluntarily single participants experienced lower fear of singlehood compared to other categories of singles and individuals in intimate relationships. Additionally, higher self-esteem was associated with lower fear of singlehood. We also identified a significant indirect effect of relationship status and self-esteem on mating effort through fear of singlehood. Specifically, involuntarily single individuals tended to exert more mating effort due to heightened fear of singlehood compared to those in other relationship status categories. Furthermore, higher self-esteem was associated with reduced mating effort, as it was associated with lower fear of singlehood. These findings held true across both the Greek and Turkish samples.Conclusion Relationship status and self-esteem play a role in mating effort through fear of singlehood.
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    The Influence of Gender Roles on Eating Attitudes: A Study Among Female College Students Abstract
    (Başkent Üniversitesi Fen Edebiyat Fakültesi, 2024-10-12) Ozel, B.; Alici, Y. Hosgoren; Kocak, O. M.; Ceran, S.
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    The Influence of Gender Roles on Eating Attitudes: A Study Among Female College Students
    (Başkent Üniversitesi Fen Edebiyat Fakültesi, 2024-10-12) Ozel, B.; Alici, Y. Hosgoren; Kocak, O. M.
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    Is There A Relationship Between The Severity Of Disease İn Major Depressive Disorder Patients And Dry Eye Disease?
    (Başkent Üniversitesi Fen Edebiyat Fakültesi, 2024-04-05) Gokce, Gizem Dogan; Metin, Merve
    PurposeTo investigate dry eye disease (DED) in newly diagnosed patients with depressive disorder (MDD). MethodThis observational study included 48 MDD patients in Group 1 and 20 healthy controls in Group 2. Psychiatric and ophthalmic examinations, Beck Depression Inventory (BDI), Ocular Surface Disease Index (OSDI), Schirmer's test, tear breakup time (TBUT), Meibomian gland dysfunction (MGD), and ocular staining were conducted. The results were statistically compared. ResultsThe participants, comprising 32 men and 36 women, had a mean age of 31.08 +/- 11.7 years (18-64 years). Group 1 had a mean BDI score of 30.87 +/- 8.56, while Group 2 had a score of 1.3 +/- 1.3 (p < 0.001). In Group 1, 28 patients were diagnosed with DED, whereas in Group 2, six subjects were diagnosed with DED. The mean Schirmer's results in Group 1 and Group 2 were (mm/5 min) 10.87 +/- 2.44 and 12.70 +/- 2.3, respectively, and were significantly lower in Group 1 (p < 0.001). The mean OSDI scores in Group 1 (34.95 +/- 15.8) were significantly higher compared to Group 2 (3.2 +/- 3.1) (p < 0.001). There was no significant difference in mean TBUT between Group 1 (9.41 +/- 2.6 s) and Group 2 (9.8 +/- 0.61 s) (p > 0.05). Significant correlations were found between BDI scores and Schirmer's results as well as OSDI scores (p < 0.05, p = 0.02, respectively). No statistically significant correlations were found between BDI scores and TBUT or MGD (p > 0.05). ConclusionDED was found to be more prevalent in the MDD group. The severity of MDD and DED, as indicated by BDI, OSDI, and Schirmer's results, was found to be correlated. It was observed that patients with higher depression scores had more severe dry eye. As a result, we recommend performing ophthalmic examinations in newly diagnosed MDD patients.
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    The Detect Consensus Report on Attention Deficit/Hyperactivity Disorder and Its Management Among Turkish Children And Adolescents (Detect: consensus report on ADHD among Turkish youth)
    (Başkent Üniversitesi Fen Edebiyat Fakültesi, 2024-04-07) Ogutlu, Hakan; Kutuk, Ozlem Meryem; Tufan, Ali Evren; Akay, Aynur Pekcanlar; Gundogdu, Ozlem Yildiz; Ercan, Eyup Sabri
    Attention Deficit/Hyperactivity Disorder (ADHD) is one of the most common and heritable neurodevelopmental disorders which may last through the life-span. A consensus report on diagnosis and management of ADHD among Turkish youth was prepared previously. However, the participants as well as the management options were rather limited and developments in the past decade necessitated a revision and update of the consensus. Therefore, this review aims to summarize the consensus among Child and Adolescent Psychiatrists from Turkiye on the nature and management of pediatric ADHD. For those aims, the etiology of ADHD, diagnostic and evaluation process, epidemiology, developmental presentations, differential diagnoses and comorbidities, course/outcome and pharmacological as well as non-pharmacological management options were reviewed and suggestions for clinical practice are presented. Since ADHD is a chronic disorder with wide-ranging effects on functionality that is frequently accompanied by other mental disorders, a multidimensional therapeutic approach is recommended. However, since the disorder has neurobiological basis, pharmacotherapy represents the mainstay of treatment. Additional therapies may include psychosocial therapy, behavioral therapy, school-based therapeutic approaches, and family education. This review provides recommendations for ADHD at the national and global levels. It contains information about ADHD that will contribute to and facilitate clinicians' decision-making processes. It is advisable to consider this guideline in clinical practice.
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    Functional Connectivity In Rumination: A Systematic Review Of Magnetic Resonance Imaging Studies
    (Başkent Üniversitesi, 2024-02-18) Misir, Emre; Alici, Yasemin Hosgoren; Kocak, Orhan Murat
    IntroductionRumination, defined as intrusive and repetitive thoughts in response to negative emotions, uncertainty, and inconsistency between goal and current situation, is a significant risk factor for depressive disorders. The rumination literature presents diverse findings on functional connectivity and shows heterogeneity in research methods. This systematic review seeks to integrate these findings and provide readers diverse perspectives.MethodFor this purpose, the literature on functional connectivity in rumination was reviewed according to the PRISMA guidelines. Regional connectivity and network connectivity results were scrutinized according to the presence of depression, research methods, and type of rumination. After screening 492 articles, a total of 36 studies were included.ResultsThe results showed that increased connectivity of the default mode network (DMN) was consistently reported. Other important findings include alterations in the connectivity between the DMN and the frontoparietal network and the salience network (SN) and impaired regulatory function of the SN. Region-level connectivity studies consistently show that increased connectivity between the posterior cingulate cortex and the prefrontal cortex is associated with rumination, which may cause the loss of control of the frontoparietal network over self-referential processes. We have seen that the number of studies examining brooding and reflective rumination as separate dimensions are relatively limited. Although there are overlaps between the connectivity patterns of the two types of rumination in these studies, it can be thought that reflective rumination is more associated with more increased functional connectivity of the prefrontal cortex.ConclusionsAlthough there are many consistent functional connectivity outcomes associated with trait rumination, less is known about connectivity changes during state rumination. Relatively few studies have taken into account the subjective aspect of this thinking style. In order to better explain the relationship between rumination and depression, rumination induction studies during episode and remission periods of depression are needed.
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    The Capacitance/Conductance And Surface State Intensity Characteristics Of The Al/(Cmat)/P-Si Structures
    (Başkent Üniversitesi Fen Edebiyat Fakültesi, 2024-02-01) Cetinkaya, H. G.; Bengi, S.; Sevgili, O.; Altindal, S.
    To determine the Al/(CMAT)/p-Si structure's admittance analysis, capacitance/conductance versus frequency (C/G-V-f) data was obtained in the 3 kHz-3 MHz and -2/4 V ranges at room temperature. The powder form of CeMgAl11O19: Tb (CMAT) was thermally evaporated onto the front of p-Si wafer at 10-6 Torr as interfacial layer. From the Nicollian and Brews method, voltage-dependent spectra of Rs were derived for various frequencies. The parallel conductance and low-high frequency capacitance (CLF-CHF) techniques, respectively, were used to determine the voltage and frequency dependent spectra of Nss and their lifetime (tau). Surface states (Nss), which are identified by admittance measurements, emerge at the M/S interlayer because of high capacitance and conductance values at low frequencies. This can also be explained by the Nss's ability to track ac signals well at lower frequencies. The normalized parallel conductance versus frequency (Gp/omega-f) plot under various biases shows a peak because of Nss existence. x-ray diffractometer (XRD) was used for structural investigation and the average crystal size (D) of the nanocrystals (CMAT) was found to be less than 0.34 nm by using the Debye-Scherer's equation.
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    Mass Migration Governance And Openness Toward Refugees: Comparing Germany And Turkey
    (INTERNATIONAL MIGRATION, 2024-01-22) Erden, Yigit; Ozcurumez, Saime
    This study seeks answers to the question: 'Under what conditions do communities with migration experience in refugee-receiving states become more open toward accepting more refugees and why?'. The research seeks answers to this question by examining the attitudes of individuals (N = 37) from Turkey who have been living in Germany for at least a year and who have sufficient familiarity with the characteristics of governance of mass migration in both countries. The findings suggest that the respondents are more pessimistic about the consequences of Turkey accepting more refugees in the future, while they are optimistic about the outcomes of the arrival of more refugees in Germany. This study posits that receiving communities' perceptions about the host state's regulatory and institutional capacity in managing mass migration and integration of refugees shape their attitudes toward the possibility of the influx of more refugees over time. The findings indicate that efficient mass migration governance in a receiving state is identified through four characteristics: (i) admission of educated refugees, (ii) proper refugee registration procedures, (iii) systematic integration processes, and (iv) effective monitoring and law enforcement mechanisms. The study concludes that local communities view public authorities as the key actors in managing the consequences of mass migration and establishing and sustaining good mass migration governance at the receiving state level is likely to facilitate positive attitudes towards accepting more refugees.