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Öğe Biomechanical analysis of titanium fixation plates and screws in mandibular angle fractures(Wolters Kluwer Medknow Publications, 2016) Atik, Fatih; Ataç, Mustafa Sancar; Özkan, Arif; Kılınç, Yeliz; Arslan, MustafaObjective: The aim of this study was to evaluate the mechanical behavior of different rigid fixation methods in mandibular angle fractures. Materials and Methods: Three different three-dimensional finite element models of the mandible were developed to simulate the biomechanical responses of titanium plates and screws. The fracture lines were fixed with double 4-hole straight, 4-hole square, and 5-hole Y plates with monocortical screws. 150 N incisal occlusal loads were simulated on the models. The commercial ANSYS software was utilized to calculate the Von Mises stresses on fixative appliances. Results: The highest Von Mises stress values were observed in the Y plate, whereas the lowest stress values have been found in the square plate. Conclusions: The use of square plate led to better stability and lower mechanical stresses than other techniques.Öğe Biomechanical analysis of titanium fixation plates and screws in sagittal split ramus osteotomies(Wolters Kluwer Medknow Publications, 2016) Atik, Fatih; Ataç, Mustafa Sancar; Özkan, Arif; Kılınç, Yeliz; Arslan, MustafaObjective: The aim of the study was to evaluate the mechanical behavior of three different fixation methods used in the bilateral sagittal split ramus osteotomy. Materials and Methods: Three different three-dimensional finite element models were created, each corresponding to three different fixation methods. The mandibles were fixed with double straight 4-hole, square 4-hole, and 5-hole Y plates. 150 N incisal occlusal loads were simulated on the distal segments. ANSYS software ((v 10; ANSYS Inc., Canonsburg, PA) was used to calculate the Von Mises stresses on fixative appliances. Results: The highest Von Mises stress values were found in Y plate. The lowest values were isolated in double straight plate group. Conclusions: It was concluded that the use of double 4-hole straight plates provided the sufficient stability on the osteotomy site when compared with the other rigid fixation methods used in this study.Öğe Dar yapraklı dişbudak (Fraxinus angustifolia vahl.) fidanlarının su eksikliğine tepkisi(Düzce Üniversitesi, 2017) Arslan, Mustafa; Çiçek, EmrahBu çalışmada Dar Yapraklı Dişbudak (DYD, Fraxinus angustifolia Vahl.) fidanlarının su eksikliğine göstermiş oldukları fizyolojik ve morfolojik tepkiler belirlenmeye çalışılmıştır. Bu amaçla türün farklı ekolojik koşullardaki sekiz adet popülasyonundan tohum toplanarak 1+0 yaşlı tüplü fidanlar yetiştirilmiştir. İkinci vejetasyon döneminde fidanlara S1: 2-3 günde bir 280 ml (tarla kapasitesi miktarı), S2: 3-4 günde bir 140 ml (tarla kapasitesinin %50'si) ve S3: 3-4 günde bir 70 ml (tarla kapasitesinin %25'i) olmak üzere 3 farklı sulama işlemi gerçekleştirilmiştir. Haziran-Eylül döneminde, her ayın ortasında fidanlar üzerinde çeşitli fizyolojik ve morfolojik ölçümler yapılmıştır. Elde edilen sonuçlar analiz edilmiş ve böylece popülasyonların su eksikliğine karşı tepkileri belirlenmeye çalışılmıştır. Fizyolojik ölçüm sonuçlarına göre; su eksikliğinin artması ile birlikte (S1'den S3'e doğru) genel olarak Haziran ayı ölçümünden Eylül ayı ölçümüne doğru, bitki su potansiyeli, klorofil a, klorofil b, toplam klorofil ve karotenoit değerlerinde azalma; prolin ve çözünebilir karbonhidrat konsantrasyonlarında ise artış görülmüştür. Fotosentetik verimlilik (Fv/Fm) değerleri Haziran ayı ölçümünde S1'den S3'e doğru azalma, diğer aylarda ise S1 ve S2 işlemleri birbirine benzer ve S3'ten yüksek değer göstermiştir. Ulaşılan sonuçlar doğrultusunda; Çifteköy-Niğde, Yavuzeli-Gaziantep, Tufanbeyli-Adana ve Akıncı-Tokat popülasyonları kuraklıktan kaçınan; Sarıkum-Sinop, Bayramdere-Bursa, Yenidoğan-Sakarya ve İğneada-Kırklareli popülasyonları ise kuraklığa toleranslı olarak değerlendirilmiştir. Yine bazı analiz sonuçlarından Akıncı-Tokat popülasyonunun kuraklığa karşı tolerans, Yenidoğan-Sakarya popülasyonunun ise kuraklıktan kaçınma özelliği/eğilimi gösterdiği belirlenmiştir. Morfolojik özellikler bakımdan, bütün popülasyonlar kök kuru ağırlığı/gövde kuru ağırlığı bakımından 2.14'ün üzerinde bir değerle yeterli kök gelişimi sağlamıştır. Kuraklıktan kaçınan popülasyonların kök kuru ağırlığı/gövde kuru ağırlığı değerleri kuraklığa toleranslı olanlardan yüksek çıkmıştır. Kuraklığa toleranslı olan popülasyonların gövde kuru ağırlığı, S3 işleminde bile, kuraklıktan kaçınan popülasyonların S1 işleminden daha yüksek saptanmıştır. Kuraklıktan kaçınma davranışı gösteren popülasyonların yetişme ortamı koşullarında genel olarak daha uzun süreli su açığı bulunmaktadır. Çalışma sonuçları doğrultusunda; yarı kurak mıntıkalardaki erozyon kontrolü çalışmalarında özellikle kuraklıktan kaçınan, ağaçlandırma ve endüstriyel plantasyonlarda ise kuraklığa toleranslı DYD popülasyonların kullanılması önerilebilir.Öğe Novel Tetrazole And 1,3,4-Oxadiazole Derivatives Synthesis, Molecular Docking, Adme, Potential Activator For Rabbit Muscle Pyruvate Kinase(Univ Babes-Bolyai, 2024) Kaya, Mustafa Oguzhan; Demirci, Tuna; Karipcin, Selman; Ozdemir, Oguzhan; Kaya, Yesim; Arslan, Mustafa. The activation of muscle pyruvate kinase (PK) increases the conversion of phosphoenolpyruvate (PEP) to pyruvate, which results in the production of ATP. This is critical for supplying the energy needed for muscle contraction. In this study, we synthesized 1,4-dihydropyridine/pyridine compounds bearing tetrazole and 1,3,4-oxadiazole groups by using Hantzsch method and characterized by FT-IR spectroscopy, elemental analysis, and The studies revealed that all original synthesized compounds activated PK and AC50 (half-maximal activating concentration) values of the compounds were extremely effective (1.30 mu M to 14.65 mu M).Öğe One-pot synthesis of Hantzsch dihydropyridines using a highly efficient and stable PdRuNi@GO catalyst(Royal Soc Chemistry, 2016) Demirci, Tuna; Çelik, Betül; Yıldız, Yunus; Eriş, Sinan; Arslan, Mustafa; Şen, Fatih; Kılbaş, BenanAddressed herein, highly monodispersed PdRuNi nanoparticles furnished with graphene oxide (PdRuNi@GO NPs) were prepared as novel, stable, efficient and exceptionally reusable heterogeneous catalysts for 1,4-dihydropyridine synthesis via multicomponent condensation reactions of various aldehydes with dimedone, ammonium acetate and ethyl acetoacetate at 70 degrees C in DMF with efficient catalytic performance. These synthesized novel materials were characterized by transmission electron microscopy (TEM), high resolution electron microscopy (HRTEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). This presented one pot catalytic process is described as a new methodology of the Hantzsch synthesis, which can be assessed as quite simple and efficient as well as exceptionally reusable. At the end of the reaction, one of the highest yields and the shortest times were obtained for the model reaction in the presence of novel monodisperse PdRuNi@GO NPs.Öğe Rabbit muscle pyruvate kinase activators: Synthesis, molecular docking and theoretical studies of N-substituted sulfonamide derivatives(Elsevier, 2024) Kaya, Mustafa Oguzhan; Demirci, Tuna; Musatat, Ahmad Badreddin; Ozdemir, Oguzhan; Sonmez, Fatih; Kaya, Yesim; Arslan, MustafaPyruvate kinase (PK) activators have potential therapeutic applications in diseases such as sickle cell anemia. In this study, N-Substituted sulfonamide derivatives of 1,4-dihydropyridines were synthesized and evaluated as PK activators in vitro and using molecular docking studies. The compounds were synthesized by reacting dicarbonyl compounds with ammonium acetate, 5-nitrobenzaldehyde, and alumina sulfuric acid (ASA), followed by reduction and sulfonylation. The structures of the compounds were analyzed using spectroscopic techniques. DFT calculations provided insights into the electronic properties. Molecular docking of the compounds into the active site of PK showed favorable binding interactions. ADME evaluation indicated suitable solubility, BBB permeation, and lack of CYP450 inhibition. Overall, this study demonstrates the potential of new hybrid 1,4-dihydropyridine substituted sulfonamides as PK activators for further development. According to AC50 values, the compound (DTS-F-7, 0.97 mu M) is about 100-fold higher affective than the clinically used sulfonamide compound (AC50 = 90 mu M) for PK.Öğe Rational Design, Synthesis, and Computational Investigation of Dihydropyridine [2,3-d] Pyrimidines as Polyphenol Oxidase Inhibitors with Improved Potency(Springer, 2024) Kaya, Mustafa Oguzhan; Kerimak-Oner, Mine Nazan; Demirci, Tuna; Musatat, Ahmad Badreddin; Ozdemir, Oguzhan; Kaya, Yesim; Arslan, MustafaPolyphenol oxidase (PPO) is an industrially important enzyme associated with browning reactions. In the present study, a set of ten new dihydropyridine [2,3-d] pyrimidines (TD-Hid-1-10) were synthesized and was found to be proven characteristically by 1H NMR, 13C NMR, IR, elemental analysis, and assessed as possible PPO inhibitors. PPO was purified from banana using three-phase partitioning, achieving an 18.65-fold purification and 136.47% activity recovery. Enzyme kinetics revealed that the compounds TD-Hid-6 and TD-Hid-7 are to be the most potent inhibitors, exhibiting mixed-type inhibition profile with IC50 values of 1.14 mu M, 5.29 mu M respectively against purified PPO enzyme. Electronic structure calculations at the B3LYP/PBE0 level of theories using def-2 SVP, def2-TZVP basis sets with various molecular descriptors characterized the electronic behavior of studied derivatives TD-Hid-1-10. Molecular electrostatic potential (MEP) and reduced density gradient analyses of RDG-NCI provided insights into charge distributions and weak intermolecular interactions. Docking study simulations predicted binding poses within crucial amino acid sequence in the 2y9x enzyme's active site, which is typically similar in sequence to the PPO form is not allowed. Ligands were analysed in terms of binding energies, inhibitor concentrations (mM) and various molecular interactions such as H-bonds, H-carbon, pi-carbon, pi-sigma, pi-sigma, pi-pi T-shaped, pi-pi stacked, pi-alkyl, Van der Waals and Cu interactions. The lowest binding energy (-7.83 kcal/mol) and the highest inhibitory effect (1.83 mM) were shown by the ligand Td-Hid-6, which forms H-bonds with Met280 and Asn260, exhibits pi-sigma interactions with His61 and pi-alkyl interactions with Val283. Other ligands also showed different interactions with various amino acids; for example, the Td-Hid-1 ligand formed H-bonds with His244 and showed pi-sigma interactions with His244 and Val283.Öğe Silicified woods from two previously undescribed early Miocene forest sites near Seben, northwest Turkey(Elsevier Science Bv, 2016) Akkemik, Ünal; Arslan, Mustafa; Poole, Imogen; Tosun, Suat; Köse, Nesibe; Kılıç, Nurgül Karlıoğlu; Aydın, AbdurrahimThis paper introduces two new Miocene fossil forest sites in northwest Turkey. Both sites lie at an altitude of 900 m close to the town of Seben in the province of Bolu. One locality is near the village of Hocas; the second lies 17 km to the northwest of the village of Kozyaka. The silicified wood represents lower parts of trunks that were felled by an eruption associated with volcanic activity in the Galatean Volcanic Province. The Hops site yielded a total of 64 samples (51 in situ and 13 ex situ). Eight in situ trunks have been identified as Salix L/Populus L, Palmae,Juniperus L, Liquidambar L and Quercus L (evergreen); ex situ Cedrus Trew., Picea Mill. and Acer L were found lying on the surface of the soil. The Kozyaka site yielded a total of 26 samples (six in situ, 20 ex situ) including Cedrus, Pinus L., Acer, Salix/Populus, evergreen Quercus and Ulmus L. Today in Turkey these genera grow in coastal locations across a narrow altitudinal range. Collating data found herein with evidence from previous studies suggests that during the early Miocene subtropical to warm temperate conditions prevailed that supported a lakeside vegetation at the Hops site and a more typical upland or mountainous zone assemblage around the Kozyaka site. (C) 2016 Elsevier B.V. All rights reserved.Öğe Synthesis and Biological Evaluation of Novel Dihydro [2,3D] Pyridine Substituted Enaminosulfonamide Compounds as Potent Human Erythrocyte Carbonic Anhydrase II (hCAII) Inhibitors(2021) Demirci, Tuna; Özdemir, Oğuzhan; Kaya, Mustafa Oğuzhan; Arslan, MustafaDihydro [2,3D] pyridine substituted enaminosulfonamide compounds have been synthesizedand their effects on carbonic anhydrase II (hCAII) have been evaluated. Pyrido [2,3 d] pyrimidines were synthesized from barbituric acid derivatives, malonanitrile, aldehyde derivatives inbasic condition and then hydrolyzed with hydrochloric acid. The targeted compounds were synthesized from amino sulfanilamide, dihydro [2,3D] pyridine compounds, and triethylorthoformate. 1H NMR, 13C NMR, FT-IR and elemental analysis were used for the structural analysisof the compounds. The half maximal inhibitory concentration (IC50) values of the compoundswere determined to be between 27.03 and 104.39 ?M for hCA II and 19.85-76.64 ?M for Ki.Öğe Synthesis, activatory effects, molecular docking and ADME studies as rabbit muscle pyruvate kinase activators of ureido phenyl substituted 1,4-dihydropyridine derivatives(Springer, 2024) Kaya, Mustafa Oguzhan; Demirci, Tuna; Calisir, Umit; Ozdemir, Oguzhan; Kaya, Yesim; Arslan, MustafaIn this study, the activation of pyruvate kinase enzyme in vitro via different urea substituents in the para position as functional groups of 1,4-dihydropyridine derivatives synthesized by Hantzsch reaction method was investigated. Elemental analysis, 1H-NMR, 13C-NMR and FT-IR spectroscopy were used to identify the ureido phenyl substituted 1,4-dihydropyridine derivatives. Virtual screening based on molecular docking supported the results of possible in vitro pyruvate kinase (PK) activators among the synthesized substances. The results showed that all compounds successfully activated PK. The strongest activator effect was shown by ethyl-4-(4-(4-(3-(3-methoxyphenyl)thioureido)phenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,7,8-hexahydroquinolin-3 (7) with an AC50 value of 87.70 mu M. In molecular docking studies, full compatibility (- 3016.93 FF), binding affinities (Delta G = - 8.58 kcal/mol), LUMO-HOMO energy gap (Delta E = 7.85 eV) in Density functional theory (DFT) studies and drug similarity score of the compounds were found to be 0.69. These results shed light on the therapeutic potential of the produced compounds to treat PK-related diseases.Öğe Synthesis, inhibition effects, molecular docking and theoretical studies as Paraoxonase 1 (PON1) inhibitors of novel 1,4-dihydropyridine substituted sulfonamide derivatives(Springer Birkhauser, 2023) Kaya, Mustafa Oguzhan; Demirci, Tuna; Özdemir, Oğuzhan; Çalışır, Ümit; Sönmez, Fatih; Arslan, MustafaThe novel sulfonamide substitute 1,4-dihydropyridine derivatives were synthesized by the method of Hantzsch reaction. They have been characterized by FT-IR spectroscopy, H-1-NMR, C-13-NMR, and elemental analysis. PON1 which is an antioxidant enzyme has important functions in cardiovascular systems. The enzyme has been purified using a two-step method such as ammonium sulfate precipitation and sepharose-4B-l-tyrosine-9-aminophenanthrene hydrophobic interaction chromatography. The results demonstrated that all the synthesized compounds inhibited PON1 enzyme. The best inhibition effect was observed in compound (1) for PON1 enzyme (IC50: 8.04 mu M, K-i: 5.43 mu M). The free radical scavenging for PON1 was discovered as 20.16 mg/mL, while drug score value was reported as 0.13 for compound (1). Furthermore, the lowest binding energy (-1.31 kcal/mol) determined by molecular docking for PON1 enzyme and the lowest LUMO-HOMO gap ( increment E = 3.12 eV) were calculated for compound (1).
