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    Graphene quantum dots prepared from dried lemon leaves and microcrystalline mosaic structure
    (Wiley, 2021) Kir, Sifa; Dehri, Ilyas; Onal, Yunus; Esen, Ramazan
    The aim of this study is to obtain graphene quantum dots (GQDs) by using Citrus limonum leaves grown in Adana Province, Mediterranean region. Thus, dried Citrus limonum leaves were subjected to carbonization at temperatures of 200, 275, 350, 425 and 500 degrees C and 90, 180, and 270 min respectively at each temperature. Characterization of the material obtained at the end of the process was determined by using X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), fluorescence spectroscopy, elemental analyzer, scanning electron microscopy (SEM), ultraviolet (UV)-visible, UV-A and UV-C lamps. It was determined that the samples obtained in the carbonization process carried out at 350 and 425 degrees C for 3 h made blue colored fluorescence. The results of the experiments completed for characterization analysis verified the GQDs and mosaic crystal structure compared to the literature. It was observed that the GQDs obtained at 350 degrees C for 3 h had maximum fluorescence properties. Radical changes at the sample matrix was observed when carbonization temperature changed from 350 degrees C to 425 degrees C.
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    The investigation of structural alteration of raw materials used to attain graphene quantum dots in different prolysis conditions
    (Elsevier, 2022) Kir, Sifa; Dehri, Ilyas; Onal, Yunus; Esen, Ramazan; Basar, Canan Akmil
    Graphene quantum dots which is one of the carbon allotrope become widespread an industrial usage due to the unique optical and electrical properties. Graphene Quantum Dots (GQDs) is obtained from the materials such as graphite, glycine, alginate, glucose whose structure contains carbon atoms. In this study, molasses that are used to attain GQDs are carbonized at the temperature of 200, 250, 300, 350 and 400 degrees C for 2 h. The DTA method was used to determine the melting temperature of the molasses. In order to determine the elemental and optical properties of the obtained graphene quantum dots particles, XRD, SEM, Elemental Analysis, Fluorescence Spectrometry techniques and UV-Visible Spectroscopy are used. Mass loss values was also determined and studied its effects were the outcome. The results obtained from these techniques show that the material obtained from the molasses is GQDs.
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    A Multi-Center Study on the Efficacy of Eltrombopag in Management of Refractory Chronic Immune Thrombocytopenia: A Real-Life Experience
    (2019) Çekdemir, Demet; Güvenç, Serkan; Özdemirkıran, Füsun; Eser, Ali; Şahin Haydaroğlu, Handan; Turak Ermiş, Esra; Esen, Ramazan; Cömert, Melda; Sadri, Sevil; Aslaner, Müzeyyen; Uncu Ulu, Bahar; Karakuş, Abdullah; Bapur Selim, Derya; Alacacıoğlu, İnci; Aydın, Demet; Tekinalp, Atakan; Namdaroğlu, Sinem; Ceran, Funda; Tarkun, Pınar; Kiper, Demet; Çetiner, Mustafa; Yenerel, Mustafa; Demir, Muzaffer Ahmet; Yılmaz, Güven; Terzi, Hatice; Atilla, Erden; Malkan, Yavuz Ümit; Acar, Kadir; Öztürk, Erman; Tombak, Anıl; Sunu, Cenk; Salim, Ozan; Alayvaz, Nevin; Sayan, Özkan; Ozan, Ülkü; Ozan, Mesut; Gökgöz, Zafer; Andıç, Neslihan; Kızılkılıç, Ebru; Noyan, Figen; Özen, Mehmet; Tanrıkulu Pepedil, Funda; Alanoğlu, Güçhan; Özkan, Hasan Atilla; Aslan, Vahap; Çetin, Güven; Akyol Erikçi, Alev; Deveci, Burak; Ersoy Dursun, Fadime; Dermenci, Hasan; Aytan, Pelin; Gündüz, Mehmet; Karakuş, Volkan; Özlü, Can; Demircioğlu, Sinan; Akay Yanar, Olga Meltem; Özatlı, Düzgün
    Abstract: Objective: The aim of the present study was to evaluate the efficacyand safety of eltrombopag, an oral thrombopoietin receptor agonist,in patients with chronic immune thrombocytopenia (ITP).Materials and Methods: A total of 285 chronic ITP patients (187women, 65.6%; 98 men, 34.4%) followed in 55 centers were enrolledin this retrospective cohort. Response to treatment was assessedaccording to platelet count (/mm3) and defined as complete (plateletcount of >100,000/mm3), partial (30,000-100,000/mm3 or doublingof platelet count after treatment), or unresponsive (<30,000/mm3).Clinical findings, descriptive features, response to treatment, and sideeffects were recorded. Correlations between descriptive, clinical, andhematological parameters were analyzed.Results: The median age at diagnosis was 43.9±20.6 (range: 3-95)years and the duration of follow-up was 18.0±6.4 (range: 6-28.2)months. Overall response rate was 86.7% (n=247). Complete andpartial responses were observed in 182 (63.8%) and 65 (22.8%)patients, respectively. Thirty-eight patients (13.4%) did not respondto eltrombopag treatment. For patients above 60 years old (n=68),overall response rate was 89.7% (n=61), and for those above 80 years old (n=12), overall response rate was 83% (n=10). Consideringthrombocyte count before treatment, eltrombopag significantlyincreased platelet count at the 1st, 2nd, 3rd, 4th, and 8th weeks oftreatment. As the time required for partial or complete responseincreased, response to treatment was significantly reduced. The timeto reach the maximum platelet levels after treatment was quitevariable (1-202 weeks). Notably, the higher the maximum plateletcount after eltrombopag treatment, the more likely that side effectswould occur. The most common side effects were headache (21.6%),weakness (13.7%), hepatotoxicity (11.8%), and thrombosis (5.9%).Conclusion: Results of the current study imply that eltrombopag isan effective therapeutic option even in elderly patients with chronicITP. However, patients must be closely monitored for response andside effects during treatment. Since both response and side effectsmay be variable throughout the follow-up period, patients should beevaluated dynamically, especially in terms of thrombotic risk factors.