5 sonuçlar
Arama Sonuçları
Listeleniyor 1 - 5 / 5
Öğe Docking and molecular dynamics calculations of some previously studied and newly designed ligands to catalytic core domain of HIV-1 integrase and an investigation to effects of conformational changes of protein on docking results(Türkiye Kimya Derneği, 2017-01-09) Ercan, SelamiNowadays, AIDS still remains as a worldwide pandemic and continues to cause many deaths which arise from HIV-1 virus. For nearly 35 years, drugs that target various steps of virus life cycle have been developed. HIV-1 integrase constitutes one of these steps which is essential for virus life cycle. Computer-aided drug design is being used in many drug development and drug improvement studies as also used in development of the first HIV-1 integrase inhibitor Raltegravir. In this study, 3 ligands which are already used as HIV-1 integrase inhibitors and 4 newly designed ligands were docked to catalytic core domain of HIV-1 integrase. Each ligand docked to three different conformations of protein. Prepared complexes (21 items) were carried out by 50 ns MD simulations and results were analyzed. Finally, the binding free energies of ligands were calculated. It was determined that designed ligands L01 and L03 gave favorable results. The questions about the ligands which have low docking scores in a conformation of protein could give better scores in another conformation of protein and if the MD simulations carry the different oriented and different localized ligands in same position at the end of simulation were answered.Öğe Design, preparation and application of a Pirkle-type chiral stationary phase for enantioseparation of some racemic organic acids and molecular dynamics studies(ACG Publications, 2017-11) Çakmak, Reşit; Ercan, Selami; Sünkür, Murat; Yılmaz, Hayrullah; Topal, GirayThis study consists of two parts. In the first part of the study; a Pirkle-type chiral stationary phase was prepared by synthesizing an aromatic amine derivative of (R)-2-amino-1-butanol as a chiral selector and binding to L-tyrosine-modified cyanogen bromide (CNBr)-activated Sepharose 4B and then, packed into the separation column. The chromatographic performance of the separation column was evaluated with racemic mandelic acid and 2-phenylpropionic acid by using phosphate buffers at three different pHs as mobile phase. In the resolution processes, the prepared solutions were loaded onto the separation column at two different concentrations and at three different pHs for each racemic organic acid, separately. Enantiomeric excess (ee%) of the eluates was determined on CHIRALPAK AD-H chiral analytical column by HPLC. The maximum ee% for mandelic acid and 2-phenylpropionic acid was determined to be 60.84 and 27.4, respectively. Separation factors (k1 ’ , k2 ’ , α, and Rs) were calculated for each acid. The structures of the obtained compounds were characterized using the spectroscopic methods (NMR, and elemental analysis). In the second part of the study; enantioselective interactions between the prepared CSP and the analytes have been widely studied by docking, molecular dynamics simulation and quantum mechanical computation methods. The reason of column eluation of rac-2-phenylpropionic acid with lower enantiomeric yield was explained by these techniques.Öğe A fuzzy logic based approach to solve interval multiobjective nonlinear transportation problem(Springer Nature, 2019-06-01) Dalman, Hasan; Sivri, MustafaThis paper presents the solution procedure of multiobjective nonlinear transportation problem (MNOTP) where the cost coefficients of the objective functions, and the supply and the unknown demand parameters have been formulated as interval numbers by the decision maker. This problem has been converted into a conventional MNOTP where to minimize the interval nonlinear objective functions, the order relations that define the choice between intervals have been determined by the interval arithmetic. Also, the constraints with interval supply and unknown demand parameters have been transformed into its deterministic forms. Then the deterministic problems have been solved by two compromise programming methods. Finally, a numerical example is presented to illustrate the efficiency of the proposed procedure as well.Öğe Extraction of lanthanum and cerium from a bastnasite ore by direct acidic leaching(TMMOB Maden Mühendisleri Odası, 2020-06-01) Özsaraç, Şafak; Kurşunoğlu, Sait; Hussaini, Shokrullah; Gökçen, Hasan Serkan; Kaya, Muammer; Altıner, Mahmut; Top, SonerThe extraction of lanthanum (La) and cerium (Ce) from a bastnasite ore by direct acidic leaching was investigated. The effects of acid concentration and leaching temperature on the extraction of La and Ce from the ore were tested. Using nitric (NHO3 ), more than 85% of the La and Ce were simultaneously extracted into leach solution whereas the La and Ce dissolutions were determined as less than 85% by using sulfuric acid (H2 SO4 ). The La dissolution exceeded 90% by using hydrochloric acid (HCl); however, the Ce dissolution remained below 85% under the following conditions: solid-to-liquid ratio of 20% (w/v), the acid concentration of 20%, leaching temperature of 25 °C and leaching time of 1 h. The result revealed that HNO3 could be used as a solvent for the maximum simultaneous extraction of the La and Ce from the bastnasite ore. The leaching temperature had no crucial effect on the dissolution of La and Ce when HNO3 or HCl solutions were preferred as a solvating agent. However, the leaching temperature had a slight positive effect on the dissolutions of La and Ce when H2 SO4 was used as a solvent.Öğe Çalışan performansının incelenmesi: Sağlık sektörü örneği(Sağlık Bilimleri Üniversitesi, 2017) Uzuntarla, Yasin; Ceyhan, Sümeyra; Fırat, İbrahimTanımlayıcı nitelikteki bu çalışmanın amacı, sağlık çalışanlarının performanslarının incelenmesi ve bazı sosyodemografik faktörlere göre farklılık varsa bunların tespit edilmesidir. Araştırma Bingöl ilindeki sağlık kurumlarında çalışan personel üzerinde uygulanmış olup, 105 kişiye ulaşılabilmiştir. Çalışmada anket yöntemi kullanılmıştır. İlk bölümde sosyodemografik özellikleri belirlemeye yönelik 6 madde, ikinci bölümde ise çalışan performansının belirlenmesine yönelik 25 madde yer almaktadır. Verilerin analizinde SPSS 22.0 programı kullanılmış olup frekans analizi, Bağımsız T testi, Mann Whitney-U testinden yararlanılmıştır. Çalışan performansı anketi puan ortalaması 45,06±10,95 bulunduğundan, katılımcıların performansının ortalamanın altında olduğu değerlendirilmektedir. Ayrıca sosyodemografik faktörlere göre çalışan performansı puan ortalamalarında istatistiksel olarak anlamlı bir farklılık bulunmamıştır. Çalışanların performansının yükseltilmesine yönelik müdahaleler yapılmasının ve sağlık yöneticilerinin konuyla ilgili farkındalıklarının oluşturulmasının olumlu katkı sağlayacağı düşünülmektedir.
