WoS
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14411/18
Browse
14 results
Search Results
Article Serum Progesterone Variability on Embryo Transfer Day in Hormone Replacement Therapy Cycles Using Intramuscular Injections During Frozen Embryo Transfers(Springer/plenum Publishers, 2025) Boynukalin, Fazilet Kubra; Tohma, Yusuf Aytac; Demir, Berfu; Gultomruk, Meral; Polyzos, Nikolaos P.; Bahceci, Mustafa; Bozda, Gurkan; Bozdağ, GürkanPurpose To assess the intra-individual variability of serum progesterone (P) levels on embryo transfer (ET) day, when the same dose of intramuscular progesterone (IM-P) was used in two consecutive hormone replacement therapy (HRT) frozen embryo transfer (FET) cycles. Methods A total of 75 patients undergoing two consecutive HRT-FET cycles in one year performed at Bahceci Ankara IVF Center between November 2019 and February 2022 were retrospectively analyzed. Serum P levels were measured at the 117th-119th hours of support by a single laboratory. The two measurements of P levels performed on the day of the first and the second FET were compared to evaluate the intra-individual variability of serum P levels. Results Comparisons between the 1st and 2nd FET cycles revealed statistically significant intra-individual variation, with an average difference of -2.47 ng/mL (95% CI: -4.65 to -0.29, p = 0.027) between the two consecutive measurements. To assess their consistency, the limit of agreement was also tested with the Bland-Altman method, in which the mean difference (+ 1.96 x SD and -1.96 x SD) was -2.47 (16.1 and -21.1). Based on a previous study, the frequency of low P levels, as expressed by being > 20.6 ng/mL on ET day, was similar between the 1st and 2nd FET cycles (14.7% vs. 9.3%, p = 0.31). Notably, most patients had improved P levels in the second cycle if initially low, while decreases were rare among those with initially higher levels. Conclusion Serum P levels may vary within the same individual across FET cycles despite the use of the same dosage of IM-P. Increasing maternal age, high body mass index, and fluctuating estradiol levels on the day of ET were identified as risk factors contributing to this variability.Article Citation - WoS: 7Citation - Scopus: 8Young Adults' Perceptions of Social Clock and Adulthood Roles in the Turkish Population(Springer/plenum Publishers, 2019) Pekel-Uludagli, Nilay; Akbas, GulcinThe aim of this study was to examine how adulthood roles (marriage and parenthood) and the perceived timing of the achievement of these roles (early, on-time, late) were related to well-being (depression and life satisfaction) and need satisfaction (autonomy, competence, and relatedness) in young adults. The sample consisted of 433 female and 244 male (N = 685) participants. Results revealed that individuals who perceived themselves as on-time for marriage reported higher levels of well-being and need satisfaction compared with individuals who perceived themselves as early or late. In addition, individuals who perceived themselves as having children on-time reported lower levels of depression and higher levels of need satisfaction compared with individuals who perceived themselves as early. For female participants, employed women have higher relatedness than non-employed women. In addition, married participants have more relatedness and life-satisfaction, and less depression than unmarried participants. The results suggest that fulfilling adulthood roles and the perceived timing of these roles affects well-being and need satisfaction.Article Citation - WoS: 1Citation - Scopus: 1On the Invariant Manifolds of the Fixed Point of a Second-Order Nonlinear Difference Equation(Springer/plenum Publishers, 2020) Turan, MehmetThis paper addresses the asymptotic approximations of the stable and unstable manifolds for the saddle fixed point and the 2-periodic solutions of the difference equationx(n+ 1)=alpha+beta x(n- 1)+x(n- 1)/x(n), where alpha> 0,0 <=beta<1$0\leqslant \beta and the initial conditionsx(- 1)andx(0)are positive numbers. These manifolds determine completely global dynamics of this equation. The theoretical results are supported by some numerical examples.Article Citation - WoS: 14Citation - Scopus: 15Leptin Promotes Proliferation of Neonatal Mouse Stem/Progenitor Spermatogonia(Springer/plenum Publishers, 2020) Yersal, Nilgun; Kose, Sevil; Horzum, Utku; Ozkavukcu, Sinan; Orwig, Kyle E.; Korkusuz, PetekPurpose To keep and increase spermatogonial stem cell number (SSC) is the only available option for pediatric cancer survivors to maintain fertility. Leptin is secreted by the epididymal white adipose tissue and has receptors on stem/progenitor spermatogonia. The purpose of this study is to demonstrate dose- and time-dependent proliferative effect of leptin on stem/progenitor spermatogonia cultures from prepubertal mice testes. Methods CD90.2 (+) stem/progenitor spermatogonia were isolated from the C57BL/6 mouse testis on postnatal day 6 and placed in culture. The proliferative effect of leptin supplementation was assessed by colony formation (diameter and number), WST proliferation assays, and xCELLigence real-time cell analysis (RTCA) on days 3, 5, and 7 of culture. Expressions of p-ERK1/2, p-STAT3, total STAT3, and p-SHP2 levels were determined by western blot analysis. Results Leptin supplementation of 100 ng/ml increased the diameter (p= 0.001) and number (p= 0.01) of colonies in stem/progenitor spermatogonial cultures and caused higher proliferation by WST-1 (p= 0.009) compared with the control on day 7. The EC50 was calculated as 114 ng/ml for leptin by RTCA. Proliferative dose of leptin induced increased expression of p-ERK1/2 (p= 0.009) and p-STAT3 (p= 0.023) on stem/progenitor spermatogonia when compared with the untreated group. Conclusion The results indicated that leptin supplementation exhibited a dose- and time-dependent proliferative effect on stem/progenitor spermatogonia that was associated with increased expression of ERK1/2 and STAT3 pathways while maintaining their undifferentiated state. This output presents a new agent that may help to expand the stem/progenitor spermatogonia pool from the neonatal testis in order to autotransplant after cancer treatment.Article Citation - WoS: 13Citation - Scopus: 15Atomistic Engineering of Chemiluminogens: Synthesis, Properties and Polymerization of 2,3-Dihydro Scaffolds(Springer/plenum Publishers, 2017) Algi, Melek Pamuk; Tirkeş, Seha; Oztas, Zahide; Cihaner, Atilla; Tirkes, Seha; Cihaner, Atilla; Algi, Fatih; Tirkeş, Seha; Cihaner, Atilla; Chemical Engineering; Chemical EngineeringTwo chemiluminescent compounds containing 2,5-di(thien-2-yl)pyrrole and pyridazine units, namely 5,7-di(thiophen-2-yl)-2,3-dihydro-1H-pyrrolo[3,4-d]pyridazine-1,4(6H)-dione (5) and 6-phenyl-5,7-di(thiophen-2-yl)-2,3-dihydro-1H-pyrrolo[3,4-d]pyridazine-1,4(6H)-dione (6), were successfully synthesized and electrochemically polymerized. The compounds have chemiluminescent properties and glow in the presence of hydrogen peroxide in basic medium. The intensity of the glow can be increased dramatically by using Fe3+ ions, hemin (1.0 ppm) or blood samples (1.0 ppm) as catalyst. The compounds 5 and 6 have one well-defined irreversible oxidation peak at 1.08 V and 1.33 V vs Ag/AgCl, respectively. Electrochemical polymerization of both 5 and 6 were carried out successfully by repeating potential scanning in the presence of BF3. Et2O in an electrolyte solution of 0.1 M LiClO4 dissolved in acetonitrile. The electronic band gaps (E-g) of the polymers P5 and P6 were found to be 2.02 eV and 2.16 eV, respectively. On the other hand, the corresponding polymers are electroactive and exhibited electrochromic features.Article Synthesis and Characterization of a Luminol Based Chemiluminescent Trimeric System(Springer/plenum Publishers, 2023) Kesimal, Busra; Balci, Burcu; Cakal, Deniz; Onal, Ahmet M.; Cihaner, AtillaA luminol based chemiluminescent trimeric system, namely 2,3-dihydro-5,8-di(thiophen-2-yl)phthalazine-1,4-dione (T2B-Lum), bearing thiophene rings as donor units and 2,3-dihydrophthalazine-1,4-dione as an acceptor unit was synthesized in two steps via donor-acceptor-donor approach using two different methods. It was found that T2B-Lum emits chemiluminescent light when exposed to H2O2 in a basic medium, and the presence of substituents and the type of aromatic ring bearing chemiluminescent active group have a direct effect on the compound's sensitivity. Among the members of a large family of metal ions, fluorescent and chemiluminescent T2B-Lum exhibited high sensitivity to Cu2+ and Fe3+ ions. Except for other metal cations (silver(I), cadmium(II), cobalt(II), iron(III), lithium(I), magnesium(II), manganese(II), nickel(II), zinc(II)), it has been observed that T2B-Lum is mostly sensitive to copper(II) ions with a detection limit value of 2.2 x 10(- 3) M. On the other hand, T2B-Lum was also found to exhibit a high sensitivity to extremely dilute aqueous solutions (e.g., 1:50.000 dilution) of blood samples, making it a promising candidate for use in forensic applications.Article Citation - WoS: 4Citation - Scopus: 4Detection of spermatogonial stem/progenitor cells in prepubertal mouse testis with deep learning(Springer/plenum Publishers, 2023) Kahveci, Burak; Onen, Selin; Akal, Fuat; Korkusuz, PetekPurposeRapid and easy detection of spermatogonial stem/progenitor cells (SSPCs) is crucial for clinicians dealing with male infertility caused by prepubertal testicular damage. Deep learning (DL) methods may offer visual tools for tracking SSPCs on testicular strips of prepubertal animal models. The purpose of this study is to detect and count the seminiferous tubules and SSPCs in newborn mouse testis sections using a DL method.MethodsTesticular sections of the C57BL/6-type newborn mice were obtained and enumerated. Odd-numbered sections were stained with hematoxylin and eosin (H&E), and even-numbered sections were immune labeled (IL) with SSPC specific marker, SALL4. Seminiferous tubule and SSPC datasets were created using odd-numbered sections. SALL4-labeled sections were used as positive control. The YOLO object detection model based on DL was used to detect seminiferous tubules and stem cells.ResultsTest scores of the DL model in seminiferous tubules were obtained as 0.98 mAP, 0.93 precision, 0.96 recall, and 0.94 f1-score. The SSPC test scores were obtained as 0.88 mAP, 0.80 precision, 0.93 recall, and 0.82 f1-score.ConclusionSeminiferous tubules and SSPCs on prepubertal testicles were detected with a high sensitivity by preventing human-induced errors. Thus, the first step was taken for a system that automates the detection and counting process of these cells in the infertility clinic.Correction The Roles of Intrusive Visual Imagery and Verbal Thoughts in Pre-Sleep Arousal of Patients With Insomnia Disorder: a Path Model ( Oct , 2023 , 10.1007/S10608-023-10442-0)(Springer/plenum Publishers, 2024) Turkarslan, Kutlu Kagan; Cinarbas, Deniz Canel; Perogamvros, Lampros[No Abstract Available]Article Citation - WoS: 3Citation - Scopus: 3The Role of Honor Concerns in Disclosing (vs. Hiding) COVID-19 Diagnosis: Insights from Turkiye(Springer/plenum Publishers, 2023) Ceylan-Batur, Suzan; Dogulu, Canay; Akbas, Gulcin; Yet, Barbaros; Uskul, Ayse K. K.Members of honor cultures value engaging in moral behaviors and managing their social image to maintain their honor. These two goals reflect reputation and integrity concerns, which also have bearing on gender roles. In the current study, we examined a) evaluations of women and men described as diagnosed with COVID-19 and as either hiding or disclosing their diagnosis, b) the moderating role of honor concerns (reputation and integrity) and the gender of the infected person in these evaluations, and c) the relationship between honor concerns and individuals' own disclosure preferences among participants living in Turkiye, a country that exemplifies an honor culture. Findings revealed that participants with stronger reputation concerns evaluated a woman's hiding behavior more favorably than that of a man's. Moreover, higher integrity concerns were associated with lower levels of participants' own preference to hide a diagnosis for both men and women, whereas reputation concerns were positively associated with a preference for hiding a diagnosis among men only. Furthermore, a content analysis of participants' open-ended explanations of their views on women's and men's motivation to hide a diagnosis revealed further evidence for the gendered nature of reputation concerns. Our findings point to the importance of prioritizing integrity concerns (and downplaying reputation concerns) in public health campaigns in honor cultures.Article Citation - WoS: 5Citation - Scopus: 3The Roles of Intrusive Visual Imagery and Verbal Thoughts in Pre-Sleep Arousal of Patients With Insomnia Disorder: a Path Model(Springer/plenum Publishers, 2023) Turkarslan, Kutlu Kagan; Cinarbas, Deniz Canel; Perogamvros, LamprosPurpose Researchers have proposed that multiple factors such as hyperarousal, conditioning, worrying, or cortical arousal play roles in the predisposition to, initiation, and perpetuation of insomnia disorder. Previously, only a few studies investigated the differential effects of intrusive visual imagery (IVI) and intrusive verbal thoughts (IVT) on pre-sleep arousal or insomnia severity. The aim of the current cross-sectional study was to examine these effects as well as the moderator role of visual imagery ability (VIA) on the relationship between IVI and pre-sleep arousal.Methods A path model comprising the variables of IVI, IVT, pre-sleep arousal, and insomnia severity was tested with 166 of 1444 participants (M-age = 25.5, SD = 5.26) who were identified as having insomnia disorder based on a 12-question form corresponding to DSM-5 criteria for insomnia disorder and Insomnia Severity Index scores (>= 8). The moderator role of VIA on the relationship between IVI and pre-sleep arousal was evaluated with a moderation analysis.Results It was found that IVI (beta = 0.44, p < .001), but not IVT (beta = 0.15, p = .12), significantly predicted pre-sleep arousal and pre-sleep arousal (beta = 0.44, p < .001) significantly predicted insomnia severity. In addition, the indirect effect of IVI via pre-sleep arousal (IE = 0.19, p < .001) on insomnia severity was significant. Finally, the moderator role of VIA on the relationship between IVI and pre-sleep arousal (p = .07) was not significant.Conclusions IVI may play a more important role in insomnia disorder than IVT. Interventions targeting pre-sleep visual imagery can help poor sleepers alleviate insomnia severity.