İstanbul Sağlık ve Teknoloji Üniversitesi Kurumsal Akademik Arşivi
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Güncel Gönderiler
Assessment of antioxidant performance of silybum marianum extract as a natural antioxidant additive in polyethylene by time-dependent melt rheology tests
(Springer Nature Link, 2026) Alanalp, Mine Begüm; Şıdım, Gizem; Mirmahmutoğulları, Esra; Pınar, Özlem; Durmuş, Ali
In this study, Silybum marianum (SM) extract as a natural primary antioxidant (PAO) additive was introduced into low density polyethylene. This primary antioxi dant was supported by a commercial grade secondary antioxidant (SAO, Irgafos® 168). The effect of compositional variations, mainly amount of SM and the weight ratio of PAO: SAO in the composition, on the thermooxidative stability of low density polyethylene (LDPE) was characterized by determining the thermal param eters, oxygen induction time (OIT) and oxidation onset temperature (OOT) using conventional thermal analysis methods performed in a DSC in air atmosphere. Fur thermore, time-dependent rheology test procedures were suggested for monitoring the thermooxidative degradation behavior of antioxidant-loaded compounds. It was found that SM loading of 0.2 or 0.5 wt% provided sufficient oxidation stability in polyethylene, at least 5 min at 240 °C under air when supported by introducing two- or three-fold of SAO. It can be concluded that these SM-Irgafos® 168 antioxi dant packages can be successfully used in polyethylenes processed in conventional melt processing windows that can be varied in 180–240 °C, in processing devices (e.g., compounder, kneader, extruders, injection molding, rotomolding) because the obtained thermorheooxidative stability times are longer than the residence time of polymer melts, approximately in the range of 1–4 min from the melting zone to die during the extrusion process.
Survival at stake: Surgical decision-making in metastatic femoral
(Acta Medica Belgica, 2025) Yücesan, Ali; Arıkan, Yavuz; Toy, Serdar; Karaduman, Volkan; Özer, Devrim
Pathological femoral fractures resulting from primary or metastatic tumors represent a complex clinical challenge for orthopedic surgeons, often requiring individualized treatment strategies. This retrospective study aimed to evaluate and compare the outcomes of different surgical approaches used in the management of pathological femoral fractures secondary to metastatic disease. A total of 46 patients (52 femoral fractures) who underwent surgical treatment between 2020 and 2023 were included in the study. Data collected encompassed demographic characteristics, tumor histology, surgical techniques employed, and clinical outcomes. Statistical analysis was conducted using appropriate parametric and non-parametric tests, depending on data distribution. Of the patients included, 51% underwent tumor resection followed by endoprosthetic reconstruction, 40% were treated with intramedullary nailing, and 9.4% underwent plate osteosynthesis. The highest postoperative mortality rate was observed among patients with lung cancer metastases. Blood transfusions were necessary in 66% of cases. The overall mean survival time following surgery was 4.5 months, with significant variation according to tumor type and metastatic burden. The findings of this study underscore the importance of a multidisciplinary approach in the surgical management of pathological femoral fractures caused by metastatic tumors. Surgical interventions such as intramedullary nailing, plate fixation, and endoprosthetic reconstruction can effectively restore mechanical stability and contribute to improved patient quality of life. Selection of the optimal surgical technique should be guided by tumor histopathology, anatomical location and extent of bone involvement, number of metastatic lesions, and overall patient prognosis. Timely and appropriate surgical intervention remains critical to minimizing complications and enhancing survival outcomes in this patient population.
Microwave assisted hydrothermal synthesis of flower shaped bismuth sulfide nanomaterial and its usage for copper removal from spiked tap water samples
(Springer Nature Link, 2026) Tezgin, Emine; Dalgıç Bozyiğit, Gamze; Zaman, Buse Tuğba; Serbest, Hakan; Turak, Fatma; Bakırdere, Sezgin
This study was designed to enhance the removal efficiency of copper ions from tap water samples by developing an adsorptive treatment method employing bismuth sulfide based nanoflowers (Bi2S3 NFs) and evaluating with the flame atomic absorption spectrophotometry (FAAS) system. A fast, and easy microwave assisted hydrothermal method was developed to synthesize Bi2S3 NFs for this application. The equilibrium adsorption investigations were conducted in tap water samples following the full optimization of all experimental parameters through univariate optimization research. As the result of optimization studies, the removal process was conducted in the conditions of 30 mg of Bi2S3 NFs for 40 mL of aqueous copper solution which was adjusted to pH 7.0 with 2.0 mL of buffer solution. The adsorption process was enhanced utilizing a sonication bath for 2.0 min before the effluent separation. The removal efficiency values, expressed as percentages, were found to be between 83.8 and 98.9% for various concentrations of copper ions in the tap water samples. Langmuir adsorption isotherm was used to model the equilibrium data. Equilibrium constant of Langmuir was calculated as 5.887 L/mg. The results obtained indicate that the adsorption mechanism of Bi2S3 NFs, when used as adsorbents, is effective to remove copper from tap water samples.
The multifaceted effects of rosmarinic acid on breast cancer, regulating autophagy and increasing apoptosis
(Taylor & Francis, 2026) Erol Kutucu, Deniz; Erkısa Genel, Merve; Üvez, Ayça; Armutak, Elif İlkay; Yılmazer, Nadim; Demirci, Huri; Soluk Tekkesin, Merva; Ulukaya, Engin; Gürel Gürevin, Ebru
Cancer remains a complex and formidable disease that necessitates the development of diverse therapeutic strategies, including the investigation of natural products as complementary agents. Rosmarinic acid (RA), a phenolic compound, has demonstrated promising anticancer activity across various malignancies. Combining RA with conventional chemotherapeutic agents may represent a novel therapeutic approach. In the present study, the efficacy of these combinations was evaluated in vitro through the assessment of cell viability, apoptosis, autophagy, and proliferation, and in vivo by examining their effects on tumor growth in an Ehrlich Ascites Carcinoma (EAC) model. Among the tested combinations, RA and Paclitaxel (PTX) exhibited enhanced cytotoxicity and synergistic activity compared with individual treatments, whereas other combinations demonstrated limited efficacy. Morphological and moleculer analyses indicated induction of apoptosis, evidenced by increased expression of FAS, FADD, and cleaved caspases detected by Western blotting. Moreover, the RA+PTX (Rosmarinic acid+Paclitaxel) combination was associated with impaired autophagic flux, as reflected by elevated LC3 and p62 levels. Although the combined treatment reduced tumor volume in vivo, its antitumor efficacy was comparable to that of RA monotherapy. Collectively, these findings indicate that while the RA+PTX combination enhanced cytotoxicity activity against triple-negative breast cancer in vitro, its therapeutic advantage in vivo requires further investigation.
The effect of phosphoric acid on the development of neural tube defects in chick embryos
(International Scientific Information, Inc., 2026) Yücel, Murat; Çetin, Eyüp; Canbaz, Halime Tuba; Karip, Betül Zehra; Demir, Emine; Kocaoğlu, Sarper; Demir, Hüseyin
Introduction: Neural tube defects (NTDs) are among the most common congenital malformations and arise from disruption of early neurulation. Phosphoric acid is a widely used food additive; however, its potential effects on early neu ral tube development have not previously been evaluated in experimental neurulation models. This proof-of concept study aimed to investigate the embryotoxic and teratogenic effects of phosphoric acid on neural tube development in a chick-embryo model of neurulation, at a single tested concentration. Material/Methods: Fertilized pathogen-free chicken eggs (n=30) were randomly allocated into 2 groups. Control embryos (n=15) received no injection, whereas embryos in the experimental group (n=15) were injected beneath the embryon ic disc with 0.25 mM phosphoric acid, at Hamburger-Hamilton stage 9. Embryos were incubated for 72 hours, after which survival was recorded and neural tube development was evaluated macroscopically and histopath ologically. Statistical comparisons were performed using Fisher’s exact test. Results: All control embryos survived (15/15, 100%) and exhibited normal neural tube closure. In the phosphoric acid–treat ed group, survival was significantly reduced (10/15, 66.7%; P=0.0421). Among surviving treated embryos, 80% (8/10) demonstrated NTDs, including cranial and caudal closure abnormalities (P<0.001). Histopathological ex amination confirmed incomplete neural fold closure, irregular notochord morphology, and disrupted somite or ganization in affected embryos. Conclusions: Phosphoric acid exposure at the tested concentration and developmental stage markedly reduced embryo sur vival and induced a high incidence of neural tube closure defects in a chick-embryo model. These findings pro vide the first experimental proof-of-concept evidence that phosphoric acid can directly disrupt early neurula tion in a vertebrate neurulation model. However, vehicle-controlled replication, dose–response analyses, and exposure-bridging studies are required to distinguish teratogenic specificity from general embryotoxicity and to assess potential relevance to human embryogenesis.
