155199 research outputs found
Sort by
Geochemical signature, detrital zircon U–Pb, and mica Ar–Ar age systematics from the Karadere Basement Unit of the İstanbul-Zonguldak Terrane (NW, Türkiye): evidence for an Avalonian-Cadomian active continental margin
No full textThe İstanbul-Zonguldak Terrane is located in northwest Anatolia and includes several outcrops with pre-Cambrian basement units. The Karadere Basement Unit represents the easternmost basement of this terrane and is composed of paragneiss, quartzite, and orthogneiss. The paragneiss and quartzite are cut by orthogneisses and disconformably overlain by Lower Ordovician to Middle Devonian cover units. Its pre-Cambrian to Palaeozoic tectonic evolution remains poorly understood, and therefore, this study reports whole-rock trace element signatures, detrital zircon U–Pb, and muscovite Ar–Ar age data for samples of paragneiss, quartzite, amphibolite, and orthogneiss. The whole-rock geochemical data indicate that the protoliths of the paragneiss and quartzite samples investigated here could have been derived from arc-related felsic magmatic units located in an active continental margin. The protoliths of amphibolites and orthogneiss samples are gabbro and granite, respectively, and their geochemical signatures are akin to those from continental arc igneous suites. The detrital zircon U–Pb data are characterized by predominantly Mesoproterozoic (84%) and lesser amount of Palaeoproterozoic and Neoproterozoic ages and suggest an early Tonian (youngest peak age of 915 ± 18 Ma) maximum depositional age. Moreover, zircon U–Pb dating analyses from an orthogneiss sample yielded an age of 603 ± 2 Ma, indicating the occurrence of mid-Ediacaran arc magmatism. This represents one of the oldest Ediacaran ages obtained from the metamagmatic basement rocks of the İstanbul-Zonguldak Terrane. Ar–Ar dating of muscovite from ortho- and paragneiss samples yielded ages of 533 ± 25 Ma and 530 ± 9 Ma, respectively, which are interpreted as early Cambrian cooling ages. Overall, the combined results reported here reveal that the Karadere Basement Unit is markedly different from NE African basement units but displays similarities to the basement rocks of both Avalonian and Amazonian terranes. It may have been formed and metamorphosed in an Avalonian–Cadomian active continental margin during the mid- to late Neoproterozoic and early Cambrian
Prognostic impact of Fusobacterium nucleatum in head and neck cancers: a meta-analysis of critical oncological outcomes
No full textBackgroundIt's a well-established fact that Fusobacterium nucleatum has been implicated in the pathogenesis and prognosis of several malignancies, but its role in head and neck cancers remains unclear. This systematic review and meta-analysis aimed to synthesize the evidence on the prognostic impact of Fusobacterium abundance in head and neck squamous cell carcinoma (HNSCC).MethodsA comprehensive literature search of PubMed/MEDLINE, Web of Science, Scopus, and Embase was performed from inception to January 1, 2000, to October 15, 2025. Studies evaluating the association between Fusobacterium and oncological outcomes in HNSCC were included. Hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) and disease-specific survival (DSS) were pooled using random and fixed-effects models. Methodological quality was assessed with the Newcastle–Ottawa Scale (NOS), and reporting adhered to the PRISMA 2020 guidelines. The study protocol was prospectively registered in INPLASY (Registration ID: INPLASY2025110054).ResultsA total of six studies met the inclusion criteria, and five studies were included in the quantitative synthesis. The pooled analysis demonstrated a significant association between high Fusobacterium abundance and improved OS (random-effects model: HR = 0.60; 95% CI: 0.38–0.95, p = 0.03; I² = 37.6%; fixed-effects model: HR = 0.61; 95% CI: 0.43–0.87, p = 0.01; I² = 40.2%) and DSS (random-effects model: HR = 0.34; 95% CI: 0.19–0.61, p < 0.001; I² = 41.6%,; fixed-effects model: HR = 0.37; 95% CI: 0.24–0.56, p < 0.001; I² = 40.1%) in patients with HNSCC. Heterogeneity was low-to-moderate, and no significant small study effect was detected based on funnel plot inspection.ConclusionsThis meta-analysis suggests that Fusobacterium nucleatum abundance is significantly associated with better OS and DSS in patients with head and neck cancers. Fusobacterium nucleatum may be a potentially useful prognostic biomarker; however, this interpretation should be made with caution due to the limited evidence base, small number of studies, and residual heterogeneity. Taken together, further validation in large-scale, prospective studies is required and critical.</p
Unilateral Yasunari nodule-like appearance in a patient without neurofibromatosis type 1
No full textMagnesium L-Threonate Reduces Hippocampal Amyloid-β Load without Cognitive Improvement in a PTU-induced Hypothyroidism Model in Young Rats
No full textThe brain is among the most critical target organs for thyroid hormones. Therefore, both congenital and acquired hypothyroidism can have significant neuropsychiatric consequences. Learning and memory problems, concentration disorders, and some psychiatric disorders such as depression can be observed in diseases causing acquired hypothyroidism. Although thyroid hormone therapy is the standard treatment, it does not always fully reverse these neuropsychiatric complications. Several studies have demonstrated the positive effects of magnesium L-threonate (MgT) supplementation on cognitive functions. Research suggests that MgT may help alleviate cognitive deficits, particularly in neurodegenerative conditions like Alzheimer’s disease, where it has been associated with improvements in memory and reductions in hippocampal amyloid-β accumulation. However, there is limited data on the effect of MgT supplementation on hypothyroid conditions in the brain. The purpose of this study was to evaluate the effects of MgT supplementation on cognitive functions in hypothyroid rats. We report that while MgT supplementation did not significantly improve cognitive performance in behavioral tasks or inflammatory markers in hypothyroid rats, it did increase hippocampal BDNF levels in euthyroid animals and reduced hippocampal amyloid-β load under both euthyroid and hypothyroid conditions. The reduction in amyloid beta load under hypothyroid conditions suggests that MgT may exert partial therapeutic effects even in the absence of thyroid hormone replacement. These findings highlight the need for further studies to evaluate the therapeutic potential of MgT, particularly in combination with thyroid hormone replacement
Effect of rivaroxaban on DNA damage in an ischemia-reperfusion model: Evaluation of 8‑OHdG levels
No full textIschemia‑reperfusion (I/R) injury is a notable cause of tissue damage, particularly in patients with peripheral artery disease. Rivaroxaban is a novel oral anticoagulant that can reduce cardiovascular events. However, its potential antioxidant properties remain poorly understood. Therefore, the present study aimed to investigate the effect of rivaroxaban on oxidative DNA injury in a rat model of I/R injury by measuring 8‑hydroxy‑2'‑deoxyguanosine (8‑OHdG) levels, a key biomarker of oxidative DNA injury. A total of 21 female Wistar albino rats were randomly divided into three groups, namely the sham, control (I/R) and rivaroxaban treatment (3 mg/kg/day) groups. Following treatment for 10 days, hind limb ischemia was induced in rats for 1 h, followed by reperfusion for 2 h. Subsequently, blood and skeletal muscle samples were collected and analyzed for oxidative stress markers, including 8‑OHdG, glutathione (GSH), oxidized GSH and malondialdehyde (MDA), using ELISA and high‑performance liquid chromatography. The results demonstrated that compared with those in the sham group, rats in the control group exhibited significantly elevated 8‑OHdG, GSSG and MDA levels, coupled with decreased GSH levels. By contrast, treatment with rivaroxaban notably reversed the elevated 8‑OHdG and MDA levels whilst restoring GSH levels compared with those in the control group, indicating an improved oxidative status. Overall, these findings suggested that in addition to its established anticoagulant properties, rivaroxaban can also protect against I/R‑induced oxidative DNA injury.</p
Hemolysis and Renal Safety of Pulsed-Field Versus Thermal Ablation for Atrial Fibrillation: A Systematic Review and Meta-Analysis
No full textBackgroundPulsed-field ablation (PFA) is a non-thermal modality for atrial fibrillation (AF) ablation; concerns persist regarding intravascular hemolysis and acute kidney injury (AKI).ObjectiveTo compare biomarker-defined hemolysis and clinical AKI after PFA versus thermal ablation.MethodsPRISMA-adherent systematic review and random-effects meta-analysis of comparative observational studies in adults undergoing AF ablation. Major databases and trial registries were searched. Risk of bias was assessed with ROBINS-I. Co-primary outcomes were change-from-baseline hemolysis biomarkers (lactate dehydrogenase [LDH], haptoglobin, bilirubin) and AKI incidence (preferentially KDIGO-defined).ResultsTwelve studies (n=5,158; AKI analysis n=4,884; 2,122 PFA, 2,762 thermal) met criteria. Versus thermal ablation, PFA produced significantly greater hemolysis: LDH mean difference (MD) +63.79 U/L (p<0.001); haptoglobin MD −0.30 g/L (p=0.036); bilirubin MD +1.91 μmol/L (p=0.023). AKI risk did not differ (risk ratio [RR] 1.14, 95% CI 0.42–3.12; p=0.80; absolute rates 3.5% vs 3.1%). PFA was associated with significantly lower major bleeding (RR 0.15, 95% CI 0.04–0.62; p=0.009) and shorter procedure time (MD −25.81 min, 95% CI −49.26 to −2.36; p=0.031). Hemolysis magnitude varied by PFA platform; AKI did not. Limitations include observational designs and heterogeneity.ConclusionPFA increases biomarker-defined intravascular hemolysis relative to thermal ablation without increasing population-level AKI. Coupled with reduced major bleeding and enhanced procedural efficiency, these data support PFA use; dose discipline, hydration, and platform selection remain important for high-risk patients.BackgroundPulsed-field ablation (PFA) is a non-thermal modality for atrial fibrillation (AF) ablation; concerns persist regarding intravascular hemolysis and acute kidney injury (AKI).ObjectiveTo compare biomarker-defined hemolysis and clinical AKI after PFA versus thermal ablation.MethodsPRISMA-adherent systematic review and random-effects meta-analysis of comparative observational studies in adults undergoing AF ablation. Major databases and trial registries were searched. Risk of bias was assessed with ROBINS-I. Co-primary outcomes were change-from-baseline hemolysis biomarkers (lactate dehydrogenase [LDH], haptoglobin, bilirubin) and AKI incidence (preferentially KDIGO-defined).ResultsTwelve studies (n=5,158; AKI analysis n=4,884; 2,122 PFA, 2,762 thermal) met criteria. Versus thermal ablation, PFA produced significantly greater hemolysis: LDH mean difference (MD) +63.79 U/L (p<0.001); haptoglobin MD −0.30 g/L (p=0.036); bilirubin MD +1.91 μmol/L (p=0.023). AKI risk did not differ (risk ratio [RR] 1.14, 95% CI 0.42–3.12; p=0.80; absolute rates 3.5% vs 3.1%). PFA was associated with significantly lower major bleeding (RR 0.15, 95% CI 0.04–0.62; p=0.009) and shorter procedure time (MD −25.81 min, 95% CI −49.26 to −2.36; p=0.031). Hemolysis magnitude varied by PFA platform; AKI did not. Limitations include observational designs and heterogeneity.ConclusionPFA increases biomarker-defined intravascular hemolysis relative to thermal ablation without increasing population-level AKI. Coupled with reduced major bleeding and enhanced procedural efficiency, these data support PFA use; dose discipline, hydration, and platform selection remain important for high-risk patients.</div
Prostaglandin İlişkili Periorbitopatide Meibomian Bezi Fonksiyon ve Morfolojisinin Prognostik Rolü
No full textGİRİŞ VE AMAÇ:Topikal prostaglandin analogları(PGA) ve prostaglandin ilişkiliperiorbitopatinin meibomian fonksiyonu ve morfolojisine etkilerini belirlemek.YÖNTEM:Çalışmaya glokom veya oküler hipertansiyon tanısı almış, en az üç aydır unilateraltopikal PGA tedavisi gören hastalar dahil edildi. Tüm hastaların gözyaşı kırılmazamanı(TBUT), Schirmer I testi, kornea boyanma skoru, kapak kenarı anormallik skoru,meibum ekspresyonu, meibografi skoru ve meibomian bez kaybı değerlendirildi. Meibomianbez morfolojisi(anormal boşluk, atrofik, bozulmuş, bulanık, hayalet, kalın, kancalı, kapakkenarına uzanmayan, kısa, kıvrımlı, tadpole, üst üste binmiş) incelendi. PGA’lar latanoprost,bimatoprost ve travoprost olarak gruplandırılarak karşılaştırıldı. Ayrıca, periorbitopati varlığı veşiddeti (grade 0, 1, 2, 3) ile meibomian fonksiyonu ve morfolojisi karşılaştırıldı.BULGULAR:64 hastanın 26'sı latanoprost, 23’ü bimatoprost ve 15’i travoprost kullanıyordu.PGA kullananlarda kornea boyanması, kapak kenarı anormallikleri, meibum ekspresyonbozukluğu ve meibomian bez kaybı anlamlı derecede yüksek, TBUT ve Schirmer değerleri isedaha düşüktü (p<0.05). PGA kullananların kapaklarında bozulmuş, kıvrımlı, kancalı, atrofik vehayalet bezlerin sıklığı kontrol grubundan yüksekti (p<0.05). Bimatoprost ve travoprostkullanan gözlerde, latanoprosta göre kancalı, atrofik ve hayalet bez oranları daha yüksekti(p<0.05). Grade 3 periorbitopati hastalarında kapak kenarı anormallik skoru, meibomianekspresyonu, meibografi skoru, atrofik, hayalet ve kenara uzanmayan bezler anlamlı olarakyüksekti(p<0.05) ve periorbitopati şiddetiyle pozitif korelasyon gösterdi(p<0.05). ROCanalizine göre, meibomian ekspresyonu, meibografi skoru, atrofik ve hayalet bezlerperiorbitopatiyi öngörmede en güçlü belirteçlerdi(p<0.05, AUC>0.80).TARTIŞMA VE SONUÇ:Topikal PGA’lar, karakteristik meibomian bezi morfolojikdeğişikliklerine yol açmakta olup, bu değişiklikler periorbitopati varlığı ve şiddeti ile ilişkilidirve periorbitopati gelişimini öngörmede etkilidir. </p
Bevacizumab combined with irinotecan or temozolomide in recurrent glioblastoma: a Turkish Oncology Group (TOG) study
No full textPurpose: Given the lack of an effective systemic therapy for recurrent glioblastoma, this study aims to compare response rates, progression-free survival, overall survival, and toxicity profiles of bevacizumab in combination with temozolomide (TMZ) versus irinotecan. Methods: We retrospectively analyzed patients with recurrent glioblastoma from seventeen oncology centers in Türkiye who received bevacizumab combined with either TMZ or irinotecan after progression. Outcomes included response rates, progression-free survival (PFS), overall survival (OS), and adverse events assessed by CTCAE v4.0. Results: Among 210 patients with recurrent glioblastoma, the median PFS was 7.9 months overall (5.2 months with TMZ–bevacizumab and 8.2 months with irinotecan–bevacizumab), and the median OS was 10.6 months overall (11.3 and 10.3 months, respectively). Six-month PFS and OS rates were 60% and 68% for the entire cohort, with no statistically significant differences between treatment regimens. Both combinations were generally well tolerated, with hypertension more frequent in the TMZ arm and liver enzyme elevation more common in the irinotecan arm. Conclusion: In this multicenter cohort of patients with recurrent glioblastoma, bevacizumab combined with either temozolomide or irinotecan demonstrated comparable PFS and OS outcomes. Both regimens were generally well tolerated, suggesting that treatment choice may be guided by individual patient profiles and toxicity considerations rather than differences in efficacy
Novel numerical technique for the second order Fredholm integro-differential equations using Bézier curves
No full textIn this study, a novel approach is proposed to approximate the solution of second order Fredholm integro-differential equations. The proposed method extends the residual method used for solving ordinary differential equations. This method is based on approximating the solution of initial value problems using a Bézier curve. For the extension of the method, some novel formulas are derived to obtain the integral of the product of Bernstein basis functions and analytic functions. The proposed method is also applied to boundary value problems with minor modifications. The most significant feature of the proposed method is its ease of application to various problems, due to its simplicity and flexibility. Error analysis is provided for both initial and boundary value problems, demonstrating that this method achieves a high order of accuracy. In order to demonstrate the accuracy and efficiency of the method, several numerical examples are provided, and their results are compared with those obtained by other methods in the literature. The findings indicate that the proposed method is highly effective and can serve as a viable alternative to existing techniques for solving Fredholm integro-differential equations