Scopus İndeksli Yayınlar

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12597/3197

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Now showing 1 - 20 of 2043

1,2,3-Triazole substituted phthalocyanine metal complexes as potential inhibitors for anticholinesterase and antidiabetic enzymes with molecular docking studies
(2022-01-01) Koçyiğit Ü.M.; Taslimi P.; Tüzün B.; Yakan H.; Muğlu H.; Güzel E.
In recent years, acetylcholinesterase (AChE) and α-glycosidase (α-gly) inhibition have emerged as a promising and important approach for pharmacological intervention in many diseases such as glaucoma, epilepsy, obesity, cancer, and Alzheimer's. In this manner, the preparation and enzyme inhibition activities of peripherally 1,2,3-triazole group substituted metallophthalocyanine derivatives with strong absorption in the visible region were presented. These novel metallophthalocyanine derivatives (2-6) effectively inhibited AChE, with Ki values in the range of 40.11 ± 5.61 to 78.27 ± 15.42 µM. For α-glycosidase, the most effective Ki values of compounds 1 and 2 were with Ki values of 16.11 ± 3.13 and 18.31 ± 2.42 µM, respectively. Also, theoretical calculations were investigated to compare the chemical and biological activities of the ligand (1) and its metal complexes (2–6). Biological activities of 1 and its complexes against acetylcholinesterase for ID 4M0E (AChE) and α-glycosidase for ID 1R47 (α-gly) are calculated. Theoretical calculations were compatible with the experimental results and these 1,2,3-triazole substituted phthalocyanine metal complexes were found to be efficient inhibitors for anticholinesterase and antidiabetic enzymes. Communicated by Ramaswamy H. Sarma.
1958 Iraq military coup with regard to Baghdad pact
(2018-03-01) Bostanci M.; Karaca E.
2-(6-Oxo-3,4-diphenyl-1,6-dihydro-pyridazin-1-yl)acetic acid
(2007-11-09) Aydin A.; Doǧruer D.; Akkurt M.; Büyükgüngör O.
In the title compound, C18H14N2O3, the pyridazine ring makes dihedral angles of 72.73 (11) and 49.97 (10)° with the two phenyl rings. The dihedral angle between the two phenyl rings is 52.42 (12)°. The crystal structure is stabilized by inter-molecular O - H⋯O and C - H⋯O hydrogen-bonding inter-actions. © International Union of Crystallography 2007.
21.2 mV/K High-Performance Ni(50 nm)-Au(100 nm)/Ga2O3/p-Si Vertical MOS Type Diode and the Temperature Sensing Characteristics with a Novel Drive Mode
(2022-12-15) Cicek O.; Arslan E.; Altindal S.; Badali Y.; Ozbay E.
Sensitivity (S) and drive mode are crucial issues for the vertical metal-oxide-semiconductor (MOS) type diode applied in temperature sensing. In this study, experimentally, we indicated that the {S} values of the Ni50nm - Au100nm /Ga2O3/ p -Si vertical MOS type diode, using the measured capacitance-voltage (Cm - V) outputs, are obtained with a novel drive mode. We applied the constant capacitance mode to drive the silicon thermo-diodes as well as constant current mode, and constant voltage mode, which are known as two different methods in the literature. Meanwhile, the S value is 21.2 mV/K at 1 nF. This value is the highest value proven in the literature excepting the cryogenic temperature region, and near room temperature. This study provided an original structure for the silicon thermo-diodes and a novel way to drive them.
3-[6-(2-Chlorobenzoyl)-2-oxo-2,3-dihydro-1,3-benzothiazol-3-yl] propanenitrile
(2006-12-01) Aydin A.; Akkurt M.; Önkol T.; Büyükgüngör O.
The title compound, C17H11ClN2O 2S, crystallizes with two crystallographically independent molecules in the asymmetric unit. In the molecular structure, there are intramolecular weak C-H⋯O hydrogen bonds, which consolidate the molecular conformation. © 2006 International Union of Crystallography All rights reserved.
3-Parameter Generalized Quaternions
(2022-09-01) Şentürk T.D.; Ünal Z.
In this article, we give a general form of the quaternions algebra depending on 3-parameters. We define 3-parameter generalized quaternions (3PGQs) and study various properties and applications. Firstly we present the definiton, the multiplication table and algebraic properties of 3PGQs. We give matrix representation and Hamilton operators for 3PGQs. We derive the polar represenation, De Moivre’s and Euler’s formulas with the matrix representations for 3PGQs. Additionally, we derive relations between the powers of the matrices associated with 3PGQs. Finally, Lie groups and Lie algebras are studied and their matrix representations are given. Also the Lie multiplication and the Killing bilinear form are given.
3D neutronic analysis in MHD calculations at ARIES-ST fusion reactors systems
(2014-01-01) Hançerliogulları A.; Cini M.
In this study, we developed new models for liquid wall (FW) state at ARIES-ST fusion reactor systems. ARIES-ST is a 1,000 MWe fusion reactor system based on a low aspect ratio ST plasma. In this article, we analyzed the characteristic properties of magnetohydrodynamics (MHD) and heat transfer conditions by using Monte-Carlo simulation methods (ARIES Team et al. in Fusion Eng Des 49-50:689-695, 2000; Tillack et al. in Fusion Eng Des 65:215-261, 2003). In fusion applications, liquid metals are traditionally considered to be the best working fluids. The working liquid must be a lithium-containing medium in order to provide adequate tritium that the plasma is self-sustained and that the fusion is a renewable energy source. As for Flibe free surface flows, the MHD effects caused by interaction with the mean flow is negligible, while a fairly uniform flow of thick can be maintained throughout the reactor based on 3-D MHD calculations. In this study, neutronic parameters, that is to say, energy multiplication factor radiation, heat flux and fissile fuel breeding were researched for fusion reactor with various thorium and uranium molten salts. Sufficient tritium amount is needed for the reactor to work itself. In the tritium breeding ratio (TBR) >1.05 ARIES-ST fusion model TBR is >1.1 so that tritium self-sufficiency is maintained for DT fusion systems (Starke et al. in Fusion Energ Des 84:1794-1798, 2009; Najmabadi et al. in Fusion Energ Des 80:3-23, 2006). © 2013 Springer Science+Business Media New York.
3D Printing of Gelatine/Alginate/β-Tricalcium Phosphate Composite Constructs for Bone Tissue Engineering
(2019-11-08) Kalkandelen C.; Ulag S.; Ozbek B.; Eroglu G.O.; Ozerkan D.; Kuruca S.E.; Oktar F.N.; Sengor M.; Gunduz O.
Bone tissue engineering studies have brought three-dimensional scaffolds into focus that can provide tissue regeneration with designed porosity and strengthened structure. Current research has concentrated on the fabrication of natural and synthetic polymer-based complex structures that closely mimic biological tissues due to their superior biocompatibility and biodegradabilities. Gelatine/Sodium Alginate hydrogels reinforced with different concentrations of β-Tricalcium Phosphate (TCP) (10, 13, and 15 wt.%) were studied to form 3D bone tissue. Physical, mechanical, chemical, morphological properties and biodegradability of the constructs were investigated. Furthermore, in vitro biological assay with human osteosarcoma cell line (SAOS-2) was performed to determine the biocompatibility of the constructs. It is found that cell viability rates for all constructs were increased and maximum cell viability rate was attained for 20%Gelatine/2%Alginate/10%TCP (wt.). The present work demonstrates that 3D printed Gelatine/Alginate/TCP constructs with porous structures are potential candidates for bone tissue engineering applications.
5-HT7 receptors as a new target for prostate cancer physiopathology and treatment: an experimental study on PC-3 cells and FFPE tissues
(2021-06-01) Cinar I.; Sirin B.; Halici Z.; Palabiyik-Yucelik S.S.; Akpinar E.; Cadirci E.
Prostate cancer (PCa) is one of the most common types of cancer seen among men worldwide. Previous studies have demonstrated that serotonin regulates cell proliferation, migration, and invasion in vitro; the presence of 5-HT receptors in cancer cells; and the role of serotonin in tumor development. The most recently discovered of these receptors is 5-HT7 but also least characterized receptors of serotonin. The aim of this study is to investigate the existence and possible role of 5-HT7 receptors in healthy and cancerous prostate tissues and also investigate effects of receptor agonists and antagonists on PC-3 cells to evaluate potential therapeutic effects. PC-3 cells were cultured and effects of 5-HT7 receptor agonist (LP-44) and antagonist (SB-269970) were evaluated on these cells. After proliferation analyses, relative expression of apoptotic markers and 5-HT7 receptor mRNA expression levels were determined through real-time PCR. Annexin V-FITC/PI double staining and Hoechst 33258 staining assay methods were applied to determine apoptosis. Additional PCR studies were performed on healthy and cancerous prostate tissue to see existence of receptors in human samples. The viability of PC-3 cells was decreased by SB-269970 after 48 and 72 h of incubation. However, LP-44 increased PC-3 cell proliferation at all time points. In 10-6 M SB-269970 treated PC-3 cells, there was significant increase in the expression of CAS-3 (4-fold), CAS-9 (2.5-fold), BAX (1.9-fold), and Tp-53 (4.8-fold) gene mRNA levels when compared to non-treated control group. Conversely, there was a significant decrease in NF-κB (2.9-fold) and 5-HT7 receptor (3.6-fold) mRNA expression in cells treated with SB-269970 when compared to control. SB-269970 that antagonized 5-HT7 receptors also induced apoptosis in Annexin V-FITC/PI double staining assay and Hoechst 33258 staining assays when compared with other groups. In human samples, 5-HT7 receptor mRNA expression was approximately 200-fold higher than that of heathy ones. In this study, for the first time, the 5-HT7 receptor antagonist SB-269970 has been shown to inhibit proliferation in PC-3 cells and to be associated with an apoptosis-inducing effect. These results suggest blocking 5-HT7 receptors can be a novel therapeutic target for the treatment of prostate cancer.
A 2-year aeropalynological survey of allergenic pollen in the atmosphere of Kastamonu, Turkey
(2012-09-01) Çeter T.; Pinar N.M.; Güney K.; Yildiz A.; Aşci B.; Smith M.
Knowledge of airborne pollen concentrations and the weather conditions influencing them is important for air quality forecasters, allergists and allergy sufferers. For this reason, a 7-day recording volumetric spore trap of the Hirst design was used for pollen monitoring between January 2006 and December 2007 in Kastamonu, Turkey. A total of 293,427 pollen grains belonging to 51 taxa were recorded during the study period. In the 2 years of study, the period March-August was identified as the main pollination season for Kastamonu. The highest monthly pollen counts were observed in May in both years. Six taxa made up 86.5% of the total amount of pollen recorded in the atmosphere of Kastamonu. These were as follows: Pinaceae (42.9%), Cupressaceae (20.6%), Poaceae (9.7%), Quercus (5.5%) Betula (5.3%) and Carpinus (2.6%). Four of these are considered to be highly allergenic (Betula, Carpinus, Cupressaceae and Poaceae). There were also a greater percentage of highly allergenic taxa found within the city, including Betula pendula that is not part of the local flora. This shows that through urban planting, the public and municipalities can unconsciously create a high risk for allergy sufferers. Daily average pollen counts from the six most frequently recorded pollen types were entered into Spearman's correlation analysis with meteorological data. Mean daily temperature, relative humidity, daily rainfall and wind speed were found to significantly (p < 0.05) affect atmospheric pollen concentrations, but the relationships between pollen concentrations and meteorological variables can vary and so there is a need for more local studies of this nature. © 2011 Springer Science+Business Media B.V.
A B3LYP/DFT Study on the Structure Activity Relationship for Benzimidazole Derivatives in Water Solution
(2022-08-01) Al-Sawaff Z.H.; Basaran M.A.; Kandemirli F.
Abstract: In this article, a theoretical chemical study on 41 benzimidazole derivatives compounds used to treat osteoporosis was performed in water phase using density functional theory (DFT) based on the 6-311 basis set and B3LYP method as the level of theory to calculate energetic behavior and quantitative chemical descriptors such as energy gap between HOMO and LUMO, the total energy of different orbital transitions, chemical hardness, softness, electrophilicity index, and electronegativity. The results showed a noticeable difference between the compounds concerning chemical parameters due to substituting the active chemical molecules at the compounds’ R1, R2, R3, and R4 sites. The results showed that compound no. 3 could be considered the most exciting compound due to its unique values obtained. On the other hand, it was found an appropriate relationship between the quantitative arithmetic variables and the IC50 values for each compound. Statistical analysis between the compounds under test and a quantitative descriptor of the ten traits were included to produce two different prediction models based on artificial neural networks due to negative and positive IC50 values after data pre-processing.
A Bayesian network model for prediction and analysis of possible forest fire causes
(2020-02-01) Sevinc V.; Kucuk O.; Goltas M.
Possible causes of a forest fire ignition could be human-caused (arson, smoking, hunting, picnic fire, shepherd fire, stubble burning) or natural-caused (lightning strikes, power lines). Temperature, relative humidity, tree species, distance from road, wind speed, distance from agricultural land, amount of burnt area, month and distance from settlement are the risk factors that may affect the occurrence of forest fires. This study introduces the use of Bayesian network model to predict the possible forest fire causes, as well as to perform an analysis of the multilateral interactive relations among them. The study was conducted in Mugla Regional Directorate of Forestry area located in the southwest of Turkey. The fire data, which were recorded between 2008 and 2018 in the area, were provided by General Directorate of Forestry. In this study, after applying some different structural learning algorithms, a Bayesian network, which is built on the nodes relative humidity, temperature, wind speed, month, distance from settlement, amount of burnt area, distance from agricultural land, distance from road and tree species, was estimated. The model showed that month is the first and temperature is the second most effective factor on the forest fire ignitions. The Bayesian network model approach adopted in this study could also be used with data obtained from different areas having different sizes.
A broad-spectrum biological activities of Heracleum humile extracts: A first report of the antiviral, anti-cancer and chemical properties
(2024-12-01) Ocal M.; Duran Yelken S.; Altunoglu Y.C.; Baloglu M.C.; Soomro S.I.; Zengin G.; Angeloni S.; Mustafa A.M.; Caprioli G.; Paksoy M.Y.
A change in the amount of CO2 at the center of the examination halls: Case study of Turkey
(2016-04-01) Cetin M.
The performances of candidates during the exam period depend on several factors, such as the temperature in exam halls. The indoor amount of CO2 is over 1000 ppm, which in turn, could directly affect the performances of the candidates directly via headache, dizziness, fatigue, and a loss of concentration. In this study, changes in the indoor amount of CO2 in some central exam were examined, and certain evaluations were made. The findings of the present study indicate that the threshold value is usually exceeded within 10 minutes, following the start of exams, and when indoor CO2 amounts are higher than 1500 ppm, which is considered in most exams as the limit of harm to health, and circulating air in the hallways and keeping the doors of exam halls open throughout the exam period are not adequate for keeping the indoor CO2 amounts below 1000 ppm. Air circulation is a must in exam halls to ensure healthy exam environments.
A combined electrochemical and theoretical study into the effect of 2-((thiazole-2-ylimino)methyl)phenol as a corrosion inhibitor for mild steel in a highly acidic environment
(2016-10-01) Yilmaz N.; Fitoz A.; Ergun Ü.; Emregül K.
2-((Thiazole-2-ylimino)methyl)phenol (THYMP) was studied as a corrosion inhibitor for the protection of mild steel in 2 M HCl solution by means of weight loss, polarization, electrochemical impedance spectroscopy and scanning electron microscopy. The potential of zero charge (Epzc), was also determined for evaluation of the adsorption mechanism. Quantum chemical parameters such as highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO), energy gap (ΔE), dipole moment (μ) etc. were calculated using density functional theory (DFT) at B3LYP/6-31G(d,p) level. Theoretical and experimental results were in fairly good agreement.
A combined experimental and computational study of electrochemical and photophysical properties of new benzophenone derivatives functionalized with N-substituted-phenyl-1,3,4-thiadiazole-2-amine
(2020-03-05) Şener İ.; Şahin Ç.; Demir S.; Şener N.; Gür M.
New benzophenone derivatives with N-substituted-1,3,4-thiadiazole including different substituents were synthesized and characterized by using FTIR, NMR, UV/Visible, and fluorescence spectroscopies and cyclic voltammetry. The effect of –F, -Cl, –OCH3 and –NO2 substitutions at ortho-, meta-, para-positions on the photoluminescence properties of the molecules have been investigated. The results indicate that the electron-donating and electron-withdrawing moieties at the ortho-, meta-, and para-positions have an important effect on the photoluminescence properties of the molecules. The calculated the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels are in the range of (−5.55) to (−5.65) eV and (−2.83) to (−3.02), respectively. The lower LUMO energy levels were observed for the molecules with –OCH3 substituents due to the donor strength of the substituent. Excited states and electrochemical properties of the molecules were also comprehensively and quantitatively studied by Density Functional Theory and Time-Dependent Density Functional Theory calculations. Experimental trends were successfully revealed by calculated data.
A combined experimental and DFT investigation of disazo dye having pyrazole skeleton
(2017-02-05) Şener N.; Bayrakdar A.; Kart H.; Şener İ.
Disazo dye containing pyrazole skeleton has been synthesized. The structure of the dye has been confirmed by using FT-IR, 1H NMR, 13C NMR, HRMS spectral technique and elemental analysis. The molecular geometry and infrared spectrum are also calculated by the Density Functional Theory (DFT) employing B3LYP level with 6-311G (d,p) basis set. The chemical shifts calculation for 1H NMR of the title molecule is done by using by Gauge-Invariant Atomic Orbital (GIAO) method by utilizing the same basis sets. The total density of state, the partial density of state and the overlap population density of state diagram analysis are done via Gauss Sum 3.0 program. Frontier molecular orbitals such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and molecular electrostatic potential surface on the title molecule are predicted for various intramolecular interactions that are responsible for the stabilization of the molecule. The experimental results and theoretical values have been compared.
A comparative analysis of the effects of rotor molding clinches on torque ripple of mutually coupled SRMS
(2011-01-01) Sahin C.; Amac A.E.; Karacor M.; Emadi A.
In this study, the mitigation of torque ripples at mutually coupled switched reluctance motor (MCSRM) is investigated experimentally. Although, MCSRMs have higher performance than classical switched reluctance machines (SRMs), they are not attractive enough due to their high torque ripples. There are many different methods to solve this problem. One of the methods is to change the geometric structure of the machine. The analyses of previous studies show that despite there being favorable results in applications, the molding pins of the machines are neglected in those works. A motor that gives positive results may get affected negatively by its random molding during generation. In this research, a 3-phase average 100 watt MCSRM is chosen for analysis and effects on torque of the geometric point of molding pins in the machine are studied comparatively. Maxwell 2D program is used for analyses and two different models are compared with each other. The obtained results show that torque ripple of the machine is lower when molding pins are closer to the rotor post, and it is reduced by 12% at 6 Amps in the proposed MCSRM. © 2011 Praise Worthy Prize S.r.l. - All righs reserved.
A comparative analysis of water quality assessment methods for heavy metal pollution in karasu stream, Turkey
(2013-04-05) Sönmez A.; Hisar O.; Yanik T.
Heavy metals are among the most persistent of pollutants in aquatic systems due to their resistance to decomposition in nature. Four assessment methods (two pollution indexes and two fuzzy mathematical models - single-factor deciding and weighted average models) were used to check the level and characteristics of heavy metal pollution in the Karasů stream water. Several heavy metals such as Copper (Cu), Zinc (Zn), Manganese (Mn), Lead (Pb), Nickel (Ni), Cadmium (Cd) and Iron (Fe) were tested with these methods. A data set (12 months, total 180 measurements) was collected from 5 sampling points (A-E) of the River. The used criteria were classes, I-IV represents from clear to polluted one. Water quality was assessed as class IV from all water samples collected from the each station with single-factor index method. It was identified to be class IV from the samples of A, B, C and D stations, and class III from the sample of E station with the comprehensive index model. By using the fuzzy mathematical methods, the water quality were determined as classes of IV, IV, IV, II and II from the water samples of A, B, C, D and E stations respectively. Introduction of membership degree and weight of each factor to fuzzy mathematical models made the methods more reasonable in the field of water quality assessment. Therefore, these fuzzy mathematical methods might be quite convenient in evaluation of water pollution and classification considering the results of the present study. © by PSP.
A comparative DFT study on Al- and Si- doped single-wall carbon nanotubes (SWCNTs) for Ribavirin drug sensing and detection
(2023-05-01) Dalgic S.S.; Al-Sawaff Z.H.; Dalgic S.; Kandemirli F.
In this work, we have presented a comparative study on Ribavirin (RBV) drug sensing and detection on the pristine and functionalized single-wall carbon nanotubes (f-SWCNTs) by Density Functional Theory (DFT) method. The pristine and metal-doped zigzag (4,0) and (6,0) SWCNTs were first considered for the RBV adsorption. All the probable positions of RBV adsorption were investigated to find which one is energetically favourable. The topology analysis of the Quantum theory of atoms in a molecule (QTAIM) with non-covalent interactions (NCI-RDG), Frontier molecular orbitals (FMO), Density of states (DOS), and non-linear optical (NLO) analysis were carried out to understand the molecular structure, electrical, electronic and optical properties of complexes. The charge analysis indicates that charge transfer is from the adsorbed RBV to the pristine and metal-doped (4,0) and (6,0) SWCNTs. The highest values of adsorption energies for Al-, Si-doped and pristine (4,0) SWCNTs were determined as −34.688, −87.999 and −10.382 kcal/mol, respectively, whereas corresponding values for metal-doped and pristine (6,0) SWCNTs are about −43.592, −20.661 and −12.414 kcal/mol, respectively. The results suggest that those bare and metal-doped (4,0) SWCNTs and (6,0) Si-SWCNTs can serve as promising sensors in practical applications to detect, recognize and carrier RBV drug for its medicinal drug delivery applications. Based on the NLO properties of (6,0) Si-SWCNTs and pristine (6,0) SWCNT (with an acceptable recovery time of 279s and first hyper polarizability value of β = 229.25 × 10−30 cm5 esu−1), those nanotubes may be possible candidates to be used as the optoelectronic sensor for RBV drug. The appropriate short length of nanotubes was obtained.

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