Chemistry / Kimya
Permanent URI for this collectionhttps://hdl.handle.net/11147/4072
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Article Citation - WoS: 7Citation - Scopus: 6Visceral Leishmaniasis Caused by Leishmania Tropica(Springer, 2023) Özbilgin, Ahmet; Tunalı, Varol; Çavuş, İbrahim; Vardarlı Tetik, Aslı; Dinç, Melike; Yalçın, Talat; Gündüz, Cumhur; Beyaz, Merve; Köse, ŞükranPurposeIn Turkey, the main causative agent of visceral leishmaniasis (VL) is Leishmania. infantum and the main causative agent of cutaneous leishmaniasis (CL) is Leishmania tropica. In this study, we aimed to discuss the possible mechanisms, clinical aspects, and threat of visceralizing L. tropica.MethodsThis study includes seven cases of VL caused by L. tropica.Five patients were male (71%) and four were adults (57%).ResultsAll the VL patients complained of fever and splenomegaly. Fatigue, pancytopenia, and hepatomegaly were present in six patients each (86%), while weight loss and gastrointestinal system (GIS) symptoms were present in 5 patients (71%).ConclusionsIn this study, we have evaluated seven cases of visceralized L. tropica (VLT) in the context of the changing leishmaniasis epidemiology in Turkey. We have evaluated the possible mechanisms of visceralization; inter- and intraspecies genetic exchange with all the old world leishmaniasis agents present in the region, stress induced by inappropriate use of drugs, and possible ongoing adaptation mechanisms of Leishmania spp. The threat posed by VLT is significant as L. tropica is the most widespread and most common cause of leishmaniasis in Turkey. We do not know the vectorial capacity of the sand flies for the transmission of VLT strains or if these strains are in circulation in Turkey. Future studies should be carried out to investigate these issues as the transition of L. tropica from a mild disease-causing agent to a mortal one poses a significant public health concern for Turkey and Europe.Article Citation - WoS: 2Citation - Scopus: 2Tuning the Solid Phase Fluorescence Emission From Long Wavelength Visible To Near-Infrared in Oxazol-5 Derivatives: Structure–property Relationship, Theoretical and Experimental Studies(Springer, 2023) Nazlı, İbrahim Hanif; Yakalı, Gül; Topkaya, Derya; İzmirli, Merve; Uzun, Sema Demirci; Alp, SerapMost of the fluorescent molecules among organic π-conjugated materials show blue or green emission in the solid phase but few of them emit red-shifted visible and near-infrared light in the material science. To create molecules emitting for this feature, two π-conjugated oxazol-5-one derivatives containing donor (OCH3) and acceptor groups (NO2) were synthesized. Their optical and charge-transport properties were investigated through experimental and theoretical methods including the single crystal X-ray crystallography, Hirshfeld Surface Analysis, photophysical studies and Density Functional Theory (DFT), respectively. In addition, FT-IR, 1H-NMR, 13C-NMR spectroscopy, cyclic voltammetry (CV) measurements were performed. According to our results, both molecules may provide the significant pathway of development of long wavelength visible and red emissive features in solid phase with the aggregation induced enhanced emission (AIEE) properties particularly in the fields of OLEDs, optical communication, defence and bioimaging.Article Citation - WoS: 6Citation - Scopus: 5Charmm Force Field Generation for a Cationic Thiophene Oligomer With Fftk(Springer, 2021) Kıbrıs, Erman; Nalıncı Barbak, Nehir; Elmacı Irmak, NuranIn the present work, CHARMM force field parameters are generated for a cationic oligomer of N, N, N-trimethyl-3-(4-methylthiophen-3-yl) oxy) propan-1-aminium) which has the potential for sensing biological molecules such as nucleic acids, nucleobases. We have used ffTK (force field tool kit) to obtain potential parameters. MD simulations are performed for 20-mer and its complexes with AMP and ATP. The simulation results are analyzed to see the number of phosphates in adenosine nucleotides effects on the structure of the backbone of oligomer. The UV-VIS calculations for the conformers which possess the most probable radius of gyration are carried out and compared to the experimental ones to validate the generated force field. Recent studies have shown that, biologically important anions (ATP, AMP, vb.) change the spectroscopic properties of cationic polythiophenes (CPT) in the solutions. This work aims to generate CHARMM compatible force field parameters for a CPT to explain experimental studies. The type of interactions will be investigated deeply to lead new biosensor studies by examining the formation and the structure of complexes that consist of a oligothiophene and biological molecules, ATP, AMP by molecular dynamic simulations.Article Citation - WoS: 7Citation - Scopus: 8Investigation of Oxygen Evolution Reaction Performance of Silver Doped Ba0.5sr0.5co0.8fe0.2o3-Delta Perovskite Structure(Springer, 2020) Göl, Emre Yusuf; Aytekin, Ahmet; Özkahraman, Ecem Ezgi; Karabudak, EnginStudies on novel electrochemical catalyst synthesis for efficient oxygen evolution reaction (OER) attract the attention of researchers. In general, changing of synthesis method and the doping metal affect the electrochemical activities of BSCF. In this work, silver doped Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF-Ag) perovskite structure is shown to be a better electrocatalyst for oxygen evolution reaction (OER) due to its lower overpotential and extended durability. BSCF structure was synthesized by the EDTA-citric acid method. Appropriate amount of Ba(NO3)(2) and EDTA were dissolved 0.1 M NH4OH solution. Nitrate salts of other metals were dissolved in distilled water, then mixed with prepared Ba(NO3)(2) solution. The mixture was stirred at 70 degrees C until gelation occurred. The gelled samples obtained were baked in a drying oven at 250 degrees C for 24 h before being calcined at 1000 degrees C for 12 h. To achieve a current density of 10 mA cm(-2), BSCF-Ag has required an overpotential of 0.36 V, which is very low compared to BSCF. To determine the stability of BSCF-Ag, continuous chronopotentiometry tests were carried out for 5 h and at a constant current density of 10 mA cm(-2). BSCF-Ag was characterized by XRD, SEM, and XPS.Article Citation - WoS: 9Citation - Scopus: 9Tuning Photoinduced Intramolecular Electron Transfer by Electron Accepting and Donating Substituents in Oxazolones(Springer, 2013) Öztürk, Gülsiye; Karabıyık, Hasan; Aygün, Muhittin; Alp, Serap; Özçelik, SerdarThe solvatochromic and spectral properties of oxazolone derivatives in various solvents were reported. Fluorescence spectra clearly showed positive and negative solvatochromism depending on substituents. The solvatochromic plots and quantum chemical computations at DFT-B3LYP/6-31+G(d,p) level were used to assess dipole moment changes between the ground and the first excited singlet-states. The electron accepting nitro substituent at the para-position increased the π-electron mobility, however, the 3,5-dinitro substituent decreased the π-electron mobility as a result of inverse accumulation of the electronic density as compared with that of its ground state. Experimental and computational studies proved that the photoinduced intramo- lecular electron transfer (PIET) is responsible for the observed solvatochromic effects. We demonstrate that PIET can be finely tailored by the position of the electron accepting and donating substituents in the phenyl ring of the oxazolone de- rivatives.We propose that the photoactive CPO derivatives are new molecular class of conjugated push-pull structures using azlactone moiety as the π-conjugated linker and may find applications in photovoltaic cells and light emitting diodes.