Browsing by Author "Kaya, I"

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    Synthesis, characterization, optical, and electrochemical properties of thermal stable novel poly(azomethine-ether)s
    Kaya, I; Avci, A; Kolcu, F; Çulhaoglu, S
    In this study, the novel Schiff base monomers were synthesized by condensation reactions. Then, these monomers were converted to poly(azomethine-ether)s by oxidative polycondensation (OP) reactions in an aqueous alkaline medium. The structural characterizations of compounds were carried out by FT-IR, NMR, and size exclusion chromatography (SEC). According to the SEC analysis, the calculated number-average molecular weight (M-n), weight average molecular weight (M-w), and polydispersity index values of P-2 and P-4 were found to be 17,500gmol(-1), 24,400gmol(-1), and 1.39; and 18,700gmol(-1), 25,600gmol(-1), and 1.36, respectively. The HOMO-LUMO energy levels, electrochemical (E-g'), and optical (E-g) band gaps of polymers were calculated from cyclic voltammetry (CV) and UV-vis measurements, respectively. CV was used to determine the electrochemical oxidation-reduction characteristics of polymers. Thermal characterizations of compounds were made by using TG-DTA and DSC techniques. According to TG analysis, polymers with higher initial degradation temperatures (T-on) than those of their monomers indicate that the synthesized polyphenols have higher thermal stabilities than their monomer species.
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    Syntheses and characterization of poly(iminophenol)s derived from 4-bromobenzaldehyde: Thermal, optical, electrochemical and fluorescent properties
    Kaya, I; Avci, A; Gültekina, Ö
    Schiff base monomers [2-(4-bromobenzylideneamino)phenol and 2-(4-bromobenzylideneamino)-5-methylphenol] were synthesized by the condensation reaction of 4-bromobenzaldehyde with aromatic aminophenols. Then, the monomers were converted to their polyphenol derivatives by oxidative polycondensation reactions (OP) in an aqueous alkaline medium. The structures of the synthesized compounds were characterized by solubility tests, FT-IR, NMR, TG-DTA, DSC and SEC techniques. The HOMO-LUMO energy levels and electrochemical (E (g) ') and optical (E (g) ) band gaps were calculated from cyclic voltammetry (CV) and UV-Vis measurements, respectively. Cyclic voltammetry (CV) was used to determine the electrochemical oxidation-reduction characteristics. Optical properties were investigated by UV-Vis and fluorescence analyses. Solid state electrical conductivities were measured on polymer films by four point probe technique using a Keithley 2400 electrometer. The effects of electron-donating (-CH3) group at p-position of -NH2 group in aminophenol on electrochemical and thermal properties were also discussed. Photoluminescence (PL) properties of the synthesized materials were determined in solution forms using different solvents. Fluorescence measurements were carried out in various concentrated solutions to determine the optimum concentrations to obtain the maximal PL intensities.
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    Synthesis, characterization, and thermal degradation of new aromatic poly(azomethine-urethane)s and their polyphenol derivatives
    Kaya, I; Avci, A
    A new polyurethane was synthesized by condensation reaction of 2,4-dihydroxy benzaldehyde (DHB) with methylene-di-p-phenyl-diisocyanate (MDI) under argon atmosphere. The synthesized polyurethane was converted to its poly (azomethine urethane) species (MP-2AP, MP-3AP, and MP4AP) by graft copolymerization reactions with amino phenols (2-amino phenol, 3-amino phenol, and 4-amino phenol). Obtained poly(azomethine urethane) s (PAMUs) were converted to their polyphenol species (P-MP-2AP, P-MP-3AP, and P-MP-4AP) by oxidative polymerization reaction (OP) using NaOCl as the oxidant. The structures of the obtained compounds were confirmed by FT-IR, UV-vis, H-1-NMR, and C-13-NMR techniques. The molecular weight distribution parameters of the synthesized compounds were determined by the size exclusion chromatography (SEC). The synthesized compounds were also characterized by solubility tests, TGDTA, and DSC analyses. Thermal decomposition steps at various temperatures were clarified by FT-IR analyses of degraded products. Fluorescence measurements were carried out in various concentrated DMF solutions to determine the optimum concentrations to obtain the maximal PL intensities.
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    Photophysical and Thermal Properties of Polyazomethines Containing Various Flexible Units
    Kaya, I; Avci, A; Temizkan, K
    In this study, the poly(azomethine-ether-urethane), poly(azomethine-ester) and poly(azomethine-epoxyether) compounds were prepared to investigate effect of various flexible units on some physical properties like thermal stability and photophysical properties. Structural characterizations were made by FTIR, H-1 NMR, C-13 NMR, and UV-Vis analyses. The molecular weight distributions of polymers were performed by gel permeation chromatography (GPC) measurement. The chemical and physical properties of polymers were examined by thermogravimetry (TG), differential scanning calorimetry (DSC), photoluminescence (PL), dynamic mechanical analysis (DMA), scanning electron microscope (SEM) and atomic force microscopy (AFM) techniques. As a result, the outstanding properties related to the photoluminescence and thermal measurements of the polymers were obtained. Therefore, the presented photoluminescent polymers could be used in thermally stable photo-functional materials.
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    Synthesis, characterization, and thermal stability of novel poly(azomethine-urethane)s and polyphenol derivatives derived from 2,4-dihydroxy benzaldehyde and toluene-2,4-diisocyanate
    Kaya, I; Avci, A
    Up to date, only a few kinds of poly(azomethine-urethane)s (PAMUs) were synthesized and studied with thermal degradation steps. However, polyphenol based PAMUs including azomethine linkages have not been investigated yet. The polyurethanes were prepared by condensation reaction of 2,4-dihydroxybenzaldehyde (2,4-DHBA) with toluene-2,4-diisocyanate (TDI) under argon atmosphere. Synthesized polyurethane was converted to its poly(azomethine urethane) species (TP-2AP, TP-3AP, and TP-4AP) by graft copolymerization reactions with amino phenols (2-amino phenol, 3-amino phenol, and 4-amino phenol). Obtained poly(azomethine urethane)s were converted to their polyphenol species (P-TP-2AP, P-TP-3AP, and P-TP-4AP) by oxidative polymerization reaction (OP) using NaOCl as the oxidant. The structures of the obtained compounds were confirmed by FT-IR. UV-vis, H-1 NMR, and C-13 NMR techniques. The molecular weight distribution parameters of the synthesized compounds were determined by the size exclusion chromatography (SEC). The synthesized compounds were also characterized by solubility tests, TG-DTA, and DSC. Fluorescence measurements were carried out in various concentrated DMF solutions to determine the optimum concentrations to obtain the maximal PL intensities. (C) 2012 Elsevier B.V. All rights reserved.
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    Conducting polymer composites based on LDPE doped with poly(aminonaphthol sulfonic acid)
    Dogan, F; Sirin, K; Kolcu, F; Kaya, I
    The paper presents the mechanical, morphological, thermal and the electrostatic charge dissipative (ESD) properties of binary blends of low-density poly (ethylene) (LDPE) blended with poly (1-amino-2-hydroxy naphthalene-4-sulfonic acid) (PANSA). Blends were prepared by loading 0.5, 1.0 and 3 wt% of PANSA into LDPE matrix in the twin-screw micro extruder. The interaction between PANSA and LDPE was then characterized by FT-IR, DSC, TG, DMA, AFM, SEM and X-RD techniques. The resulting polyolefin-based blends were also investigated by stress-strain curves in order to analyze some physico-mechanical properties. Percentages of the crystallinity of the blends were calculated by FT-IR, DSC and X-RD analyses. The conductivity of PANSA/LDPE blends was determined to be in the range of 10(-11) - 10(-12) S cm(-1) using ESD applications. The antistatic decay time of blend films was found to be of the order of 0.103-1.721 secat corona voltages between -3 kV and 3 kV, concluding that PANSA can be used as an effective ESD material for antistatic coatings of LDPE.
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    Synthesis, Characterization and Conductivity Properties of Novel Oligomer Schiff Bases Derived from 4-Amino-3-hydrazino-5-mercapto-1, 2, 4-triazole and Their Reactions with VO(IV), Cu(II) Ions
    Kaya, I; Erçag, A; Avci, A; Çulhaoglu, S
    A new Schiff base, 4-(4-hydroxysalicylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole (4HSAHMT), and novel Schiff base oligomers of 4-salicylidenamino-3-hydrazino-5-mercapto-1,2,4-triazole (SAHMT), 4-(2-hydroxynaphthylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole (2HNAHMT), 4-(4-hydroxysalicylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole (4HSAHMT) and 4-(5-bromosalicylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole (BrSAHMT) were synthesized via oxidative polymerization using NaOCl as the oxidant. The structures of the oligomers were supported by FT-IR, UV-Vis, H-1-NMR, and C-13-NMR techniques. The compounds were further characterized by solubility tests, TG-DTA, and elemental analysis. The molecular weight distribution parameters of the compounds were determined by the size exclusion chromatography (SEC). According to SEC, the number average molecular weight (M (n) ) values of O-SAHMT, O-BrSAHMT, O-4HSAHMT and O-2HNAHMT were 2,700, 2,100, 2,700 and 1,000 g mol(-1), respectively. The weight losses of O-SAHMT, O-BrSAHMT, O-4HSAHMT and O-2HNAHMT were 73, 76, 80 and 54 %, respectively, at 1,000 A degrees C. TG analyses showed that the synthesized oligomers were stable toward thermal decomposition. The synthesized oligomers were converted to metal complexes with salts of VO(IV) and Cu(II). The doped and undoped electrical properties of oligomers and oligomer-metal complexes were determined by the four-point probe technique at room temperature and atmospheric pressure.
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    Synthesis of Novel crosslinked Poly(azomethine-urethane)s: Photophysical and thermal properties
    Avci, A; Kamaci, M; Kaya, I; Yildirim, M
    This paper describes synthesis, photophysical, electrochemical and thermal properties of some new flexible crosslinked poly(azomethine-urethane)s. Synthesis procedure includes two main steps: The first one is the synthesis of a polyurethane prepolymer (TP) using toluene-2,4-diisocyanate and 2,4-dihydroxy benzaldehyde, and the second step is the synthesis of resulting flexible crosslinked poly(azomethineurethane) derivatives by conventional polycondensation reaction of TP with different aliphatic diamines. Diamines with various chain lengths (6-12 methylene numbers) were used to obtain various resulting polymers with different physical properties. Photophysical properties of the flexible crosslinked poly(azomethine-urethane)s were investigated using photoluminescence (PL). PL results showed that the flexible crosslinked poly(azomethine-urethane)s exhibited multicolor emission behavior. A linear relationship was observed between the excitation energies and the obtained emission maxima. This characteristic enabled adjusting the PL color at the desired scale. Thermal and morphological properties of the polymers were also investigated using TG-DTA, DSC and AFM techniques. (C) 2015 Elsevier B.V. All rights reserved.
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    New Poly(azomethine-urethane)s Including Melamine Derivatives in the Main Chain: Synthesis and Thermal Characterization
    Kaya, I; Yildirim, M; Kamaci, M; Avci, A
    Up to date, only a few kinds of poly (azomethine-urethane)s (PAMUs) derived from aromatic hydroxy compounds were obtained and studied with thermal degradation steps. Novel PAMUs were prepared using the hydroxy-functionalized Schiff bases derived from melamine and toluene-2,4-diisocyanate. Schiff base prepolymers were synthesized by the condensation reaction of melamine with 4-hydroxybenzaldehyde and 2hydroxy-1-naphtaldehyde. Characterization was made by UV-Vis, FTIR, NMR, and SEC techniques. Thermal characterizations of the novel PAMUs were carried out by TG-DTA and DSC techniques. Thermal decomposition steps at various temperatures were also clarified and the physical changes of the synthesized PAMUs with exposing to the thermal degradation steps were displayed. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 120: 3027-3035, 2011
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    Synthesis and thermal characterization of novel poly(azomethine-urethane)s derived from azomethine containing phenol and polyphenol species
    Kaya, I; Yildirim, M; Avci, A; Kamaci, M
    Oligophenol-based poly(azomethine-urethane)s (PAMUs) were newly synthesized in two steps. At the first step, the prepolymers including the phenol and oligophenol based-Schiff bases were prepared by a condensation reaction of o-dianisidine with 4-hydroxybenzaldehyde/3-ethoxy-4-hydroxybenzaldehyde, and the polycondensation reactions of the corresponding Schiff bases in an aqueous alkaline media. At the second step, the PAMUs were obtained by copolymerization of the prepolymers with toluene-2,4-diisocyanate (TDI) under an argon atmosphere. The structures of the obtained compounds were confirmed by FTIR, UV-vis, H-1 NMR, and C-13 NMR, and size exclusion chromatography (SEC) techniques. The synthesized compounds were also characterized by TG-DTA and DSC analyses. Thermal decomposition steps at various temperatures were clarified by FTIR analyses of the degraded products. The physical changes to the synthesized PAMUs after exposing them to the thermal degradation steps are displayed.
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    The crosslinked poly(azomethine-urethane)s containing o-hydroxyazomethine: Tunable multicolor emission, photophysical and thermal properties
    Kamaci, M; Avci, A; Kaya, I
    This article presents synthesis, photophysical, electrochemical, thermal, and morphological properties of the crosslinked polyurethanes (CLPUs). CLPUs were synthesized in two main steps. In the first step, aldehyde functionalized polyurethane prepolymer was synthesized using 2,4-dihydroxy benzaldehyde and hexamethylene diisocyanates. In the second step, the prepared prepolymer was converted to the crosslinked polyurethane derivatives using different diamines via condensation reaction. Diamines with various chain length and side-group substitutions were used as crosslinker. Photophysical properties of the crosslinked polyurethanes were investigated using UV-vis and photoluminescence (PL) spectra techniques. Fluorescence measurements showed that CLPUs exhibited multicolor emission behavior. Additionally, a linear relationship is determined between the excitation energies and the obtained emission maxima and, this property allows tuning the PL color by changing the source light energy on the desired scale. (C) 2015 Elsevier B.V. All rights reserved.
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    Fluorescence, thermal and electrochemical properties of poly(azomethine-urethane)s containing sulfone group
    Avci, A; Temizkan, K; Kaya, I
    In this study, the new sulfone group-containing poly(azomethine-urethane)s (PAZUs) were synthesized to investigate the effects various diisocyanates on the thermal, fluorescence, electrochemical and morphological properties. The structures of PAZUs have been confirmed by FT-IR, NMR, and SEC analyses. The electrochemical behaviors of the PAZUs were examined by cyclic voltammetry. Optical properties were investigated by UV-Vis and fluorescence measurements. The PAZUs were further characterized by TGA, DSC, SEM, and AFM techniques. TGA analyses results showed considerable increase in the thermal stability of polyurethanes due to the introduction of azomethine bond in the main chain. Consequently, because of the fine thermal properties the obtained materials can be used to produce thermally stable materials.
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    Effect of CaCO3 Filler Component on Solid State Decomposition Kinetic of PP/LDPE/CaCO3 Composites
    Sirin, K; Dogan, F; Balcan, M; Kaya, I
    In this study, the effect of addition Calcium carbonate (CaCO3) filler component on solid state thermal decomposition procedures of Polypropylene-Low Density Polyethylene (PP-LDPE; 90/10 wt%) blends involving different amounts (5, 10, 20 wt%) Calcium carbonate (CaCO3) was investigated using thermogravimetry in dynamic nitrogen atmosphere at different heating rates. An integral composite procedure involving the integral iso-conversional methods such as the Tang (TM), the Kissinger-Akahira-Sunose method (KAS), the Flynn-Wall-Ozawa (FWO), an integral method such as Coats-Redfern (CR) and master plots method were employed to determine the kinetic model and kinetic parameters of the decomposition processes under non-isothermal conditions. The Iso-conversional methods indicated that the thermal decomposition reaction should conform to single reaction model. The results of the integral composite procedures of TG data at various heating rates suggested that thermal processes of PP-LDPE-CaCO3 composites involving different amounts of CaCO3 filler component (5, 10, 20 wt%) followed a single step with approximate activation energies of 226.7, 248.9, and 252.0 kJ.mol- 1 according to the FWO method, respectively and those of 231.3, 240.1 and 243.0 kJ mol- 1 at 5 degrees C min- 1 according to the Coats-Redfern method, the reaction mechanisms of all the composites was described from the master plots methods and are Pn model for composite C-1, Rn model for composites C-2 and C-3, respectively. It was found that the thermal stability, activation energy and thermal decomposition process changed by the increasing CaCO3 filler weight in composite structure.
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    The influence of CaCO3 filler component on thermal decomposition process of PP/LDPE/DAP ternary blend
    Dogan, F; Sirin, K; Kaya, I; Balcan, M
    Polypropylene-low density polyethylene (PP-LDPE) blends involving PP-LDPE (90/10 wt%.) with (0.06 wt%) dialkyl peroxide (DAP) and different amounts (5, 10, 20 wt%) of calcium carbonate (CaCO3) were prepared by melt-blending with a single-screw extruder. The effect of addition of CaCO3 on thermal decomposition process and kinetic parameters, such as activation energy and pre-exponential factor of PP-LDPE blend with DAP matrix, was studied. The kinetics of the thermal degradation of composites was investigated by thermogravimetric analysis in dynamic nitrogen atmosphere at different heating rates. TG curves showed that the thermal decomposition of composites occurred in one weight-loss stage. The apparent activation energies of thermal decomposition for composites, as determined by the Tang method (TM), the Kissinger-Akahira-Sunose method (KAS), the Flynn-Wall-Ozawa method (FM)), and the Coats-Redfern (CR) method were 156.6, 156.0, 159.8, and 167.7 KJ.mol(-1) for the thermal decomposition of composite with 5 wt% CaCO3, 191.5, 190.8, 193.1, and 196.8 kJ.mol(-1) for the thermal decomposition of composite with 10 wt% CaCO3, and 206.3, 206.1, 207.5, and 203.8 kJ mol(-1) for the thermal decomposition of composite with 20 wt% CaCO3, respectively. The most likely decomposition process for weight-loss stages of composites with CaCO3 content 5 and 10 wt% was an A sigmoidal type. However, the most likely decomposition process for composite with CaCO3 content 20 wt% was an R-n contracted geometry shape type in terms of the CR and master plots results. It was also found that the thermal stability, activation energy, and thermal decomposition process were changed with the increase in the CaCO3 filler weight in composite structure. Copyright (C) 2009 John Wiley & Sons, Ltd.
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    Synthesis, characterization and non-isothermal decomposition kinetic of a new galactochloralose based polymer
    Kök, G; Ay, K; Ay, E; Dogan, F; Kaya, I
    A glycopolymer, poly(3-O-methacroyl-5,6-O-isopropylidene-1,2-O-(S)-trichloroethylidene-alpha-D-galactofuranose) (PMIPTEG) was synthesized from the sugar-carrying methacrylate monomer, 3-O-methacroyl-5,6-O-isopropylidene-1,2-O-(S)-trichloroethylidene-alpha-D-galactofuranose (MIPTEG) via conventional free radical polymerization with AIBN in 1,4-dioxane. The structures of glycomonomer and their polymers were confirmed by UV-vis, FT-IR, H-1 NMR, C-13 NMR, GPC, TG/DTG-DTA, DSC, and SEM techniques. SEM images showed that PMIPTEG had a straight-chain length structure. On the other hand, the thermal decomposition kinetics of polymer were investigated by means of thermogravimetric analysis in dynamic nitrogen atmosphere at different heating rates. The apparent activation energies for thermal decomposition of the PMIPTEG were calculated using the Kissinger, Kim-Park, Tang, Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS) and Friedman methods and were found to be 100.15, 104.40, 102.0, 102.2, 103.2 and 99.6 kJ/mol, respectively. The most likely process mechanism related to the thermal decomposition stage of PMIPTEG was determined to be a D deceleration type in terms of master plots results. (C) 2013 Elsevier Ltd. All rights reserved.
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    Eating attitudes of migraine patients in Turkey: a prospective multi-center study
    Ocal, R; Karakurum-Goksel, B; Van, M; Coskun, O; Karaaslan, C; Ucler, S; Gokcay, F; Celebisoy, N; Sirin, H; Ak, AK; Saritas, AS; Sirin, TC; Bayir, BRH; Ekizoglu, E; Orhan, EK; Bayram, D; Tanik, N; Bicakci, S; Ozturk, V; Inan, LE; Metin, KM; Eren, Y; Dora, B; Oguz-Akarsu, E; Karli, N; Celik, EU; Atalar, AC; Celik, RGG; Mutluay, B; Aydinlar, EI; Dikmen, PY; Semercioglu, S; Emre, U; Buldukoglu, OC; Er, B; Kilboz, BB; Ibis, S; Yagiz, S; Koklu, H; Kamaci, I; Aliyeva, G; Ates, BE; Kara, MM; Altunc, FZ; Kaya, I; Sisman, C
    Background Migraine is a disease characterized by headache attacks. The disease is multifactorial in etiology and genetic and environmental factors play role in pathogenesis. Migraine can also be accompanied by psychiatric disorders like neurotism and obsessive compulsive disorder. Stress, hormonal changes and certain food intake can trigger attacks in migraine. Previous studies showed that eating attitudes and disorders are prevalant in patients with migraine. Eating disorders are psychiatric disorders related to abnormal eating habits. Both migraine and eating disorders are common in young women and personality profiles of these patient groups are also similar. A possible relationship which shows that migraine and eating habits are related can lead to a better understanding of disease pathogenesis and subsequently new therapeutic options on both entities. Association of migraine in relation to severity, depression and anxiety and eating habits and disorders were aimed to be investigated in this study.Methods The study was designed as a prospective, multi-center, case control study. Twenty-one centers from Turkey was involved in the study. The gathered data was collected and evaluated at a single designated center. From a pool of 1200 migraine patients and 958 healthy control group, two groups as patient group and study group was created with PS matching method in relation to age, body-mass index, marital status and employment status. Eating Attitudes Test-26 (EAT-26), Beck's Depression Inventory (BDI) and Beck's Anxiety Inventory (BAI) were applied to both study groups. The data gathered was compared between two groups.Results EAT-26 scores and the requirement for referral to a psychiatrist due to symptoms related to eating disorder were both statistically significantly higher in patient group compared to control group (p = 0.034 and p = 0.0001 respectively). Patients with migraine had higher scores in both BDI and BAI compared to control group (p = 0.0001 and p = 0.0001 respectively). Severity of pain or frequency of attacks were not found to be related to eating attitudes (r:0.09, p = 0.055).Conclusions Migraine patients were found to have higher EAT-26, BDI and BAI scores along with a higher rate of referral to a psychiatrist due to symptoms. Results of the study showed that eating habits are altered in migraine patients with higher risk of eating disorders. Depression and anxiety are also found to be common amongst migraine patients.
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    Lung cancer from suspicion to treatment: An indicator of healthcare access in Turkey
    Kizilirmak, D; Kaya, ZY; Gökçimen, G; Havlucu, Y; Özyurt, BC; Gündogus, B; Esendagli, D; Kaya, BS; Yilmam, I; Aydemir, Y; Çolak, M; Afsin, E; Çetin, N; Idikut, A; Degirmenci, C; Tapan, ÖO; Gürkan, CG; Kocatürk, CI; Simsek, GÖ; Kalafat, CE; Niksarlioglu, EYÖ; Serdaroglu, ME; Karcioglu, O; Özyurt, S; Madran, EK; Bayrak, BY; Alasgarova, Z; Toprak, OB; Uçar, EY; Topal, BN; Baris, SA; Guliyev, E; Güzel, E; Küçük, S; Ocakli, B; Ketencioglu, BB; Selçuk, NT; Akyüz, MS; Özgür, ES; Yetkin, NA; Çetinkaya, PD; Deniz, PP; Atli, S; Çetindogan, H; Karakas, FG; Yilmaz, ES; Ergün, D; Ergcn, R; Tulay, CM; Ünsal, M; Demirkaya, I; Marim, F; Kaya, I; Demirdögen, E; Dilektasli, AG; Ursavas, A; Çelik, P
    Background: Lung cancer is the leading cause of cancer-related deaths worldwide. Before beginning lung cancer treatment, it is necessary to complete procedures such as suspecting lung cancer, obtaining a pathologic diagnosis, and staging. This study aimed to investigate the processes from suspicion of lung cancer to diagnosis, staging, and treatment initiation. Metbods: The study was designed as a multicenter and cross-sectional study. Patients with lung cancer from various health institutions located in all geographic regions of Turkey were included in the study. The socio-demographic and clinical characteristics of the patients, the characteristics of the health institutions and geographic regions, and other variables of the lung cancer process were recorded. The time from suspicion of lung cancer to pathologic diagnosis, radiologic staging, and treatment initiation, as well as influencing factors, were investigated. Results: The study included 1410 patients from 29 different medical centers. The mean time from the initial suspicion of lung cancer to the pathologic diagnosis was 48.0 +/- 52.6 days, 39.0 +/- 52.7 days for radiologic staging, and 74.9 +/- 65.5 days for treatment initiation. The residential areas with the most suspected lung cancer cases were highly developed socioeconomic zones. Primary healthcare services accounted for only 0.4% of pa-tients with suspected lung cancer. The time to pathologic diagnosis was longer in the Marmara region, and the wait time for staging and treatment initiation was longer in Eastern and Southeastern Anatolia. Patients who presented to chest disease referral hospitals with peripheral lesions, those with early-stage disease, and those who were diagnosed surgically had significantly longer wait times. Conclusion: The time between pathologic diagnosis, staging, and treatment initiation in lung cancer was longer than expected. Increasing the role of primary healthcare services and distributing socioeconomic resources more equally will contribute to shortening the time to diagnosis and improve treatment processes for lung cancer.
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    What We Learned about COVID-19 So Far? Notes from Underground
    Akyil, FT; Karadogan, D; Gürkan, CG; Yüksel, A; Arikan, H; Eyüboglu, TS; Emiralioglu, N; Gürsoy, TR; Serifoglu, I; Toreyin, ZN; Marim, F; Kara, BY; Özakinci, H; Develi, E; Çakmakci, S; Kusbeci, TC; Karcioglu, O; Gulhan, PY; Erçelik, M; Er, B; Ataoglu, Ö; Polat, D; Kaya, I; Önyilmaz, TA; Aydin, A; Kizilirmak, D; Er, AB; Kilinç, M; Günaydin, FE; Gürz, S; Karaoglanoglu, S; Çelik, S; Esendagli, D; Toptay, H; Sertçelik, UÖ; Akgün, M
    The novel coronavirus pandemic poses a major global threat to public health. Our knowledge concerning every aspect of COVID-19 is evolving rapidly, given the increasing data from all over the world. In this narrative review, the Turkish Thoracic Society Early Career Taskforce members aimed to provide a summary on recent literature regarding epidemiology, clinical findings, diagnosis, treatment, prevention, and control of COVID-19. Studies revealed that the genetic sequence of the novel coronavirus showed significant identity to SARS-CoV and MERS-CoV. Angiotensin-converting enzyme 2 receptor is an important target of the SARS-CoV-2 while entering an organism. Smokers were more likely to develop the disease and have a higher risk for ICU admission. The mean incubation period was 6.4 days, whereas asymptomatic transmission was reported up to 25 days after infection. Fever and cough were the most common symptoms, and cardiovascular diseases and hypertension were reported to be the most common comorbidities among patients. Clinical manifestations range from asymptomatic and mild disease to severe acute respiratory distress syndrome. Several patients showed typical symptoms and radiological changes with negative RT-PCR but positive IgG and IgM antibodies. Although radiological findings may vary, bilateral, peripherally distributed, ground-glass opacities were typical of COVID-19. Poor prognosis was associated with older age, higher Sequential Organ Failure Assessment score, and high D-dimer level. Chloroquine was found to be effective in reducing viral replication in vitro. Likewise, protease inhibitors, including lopinavir/ritonavir, favipiravir, and nucleoside analogue remdesivir were proposed to be the potential drug candidates in COVID-19 management. Despite these efforts, we still have much to learn regarding the transmission, treatment, and prevention of COVID-19.
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    A new selective fluorescent sensor for Zn(II) ions based on poly(azomethine-urethane)
    Avci, A; Kaya, I
    A new and selective fluorescent sensor based on poly(azomethine-urethane) (PAMU) is synthesized and characterized by FT-IR, H-1 NMR, and size exclusion chromatography (SEC) techniques. The new sensor shows a high selectivity for Zn(II) over other metal cations in DMF/deionized H2O (1:2, v/v). The fluorescence sensor gives a linearly and highly stable response to Zn(II) as an increasing emission peak at 595 nm. The sensitivity limit of the new sensor is found to be 11.4 x 10(-3) mol L-1. The results show that the proposed sensor can be efficiently used as a simple method for the detection of Zn(II) ions. (C) 2015 Elsevier Ltd. All rights reserved.
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    Synthesis of thermally stable and low band gap poly(azomethine-urethane)s containing fluorene unit in the backbone
    Kaya, I; Avci, A; Temizkan, K
    New poly(azomethine-urethane)s (PAMU)s were prepared to investigate the effects of different four diisocyanates on some physical properties such as thermal stability, optical and electrochemical properties. First, the fluorene Schiff base was synthesized as in the literature. Then, this Schiff base was converted to poly(azomethine-urethane)s using diisocyanates (2,4-toluenediisocyanate, 1,4-phenylene diisocyanate, methylene-di-p-phenyl-diisocyanate, and hexamethylene-diisocyanate) via condensation reaction. Second, the structures of PAMUs were confirmed by FT-IR, NMR, and UV-Vis spectral analyses. Cyclic voltammetry (CV) was used to determine the electrochemical oxidationreduction characteristics of (PAMU)s. The CV results of PAMUs compounds showed to have an electrochemical band gap below such as 2.0 eV. The PAMUs were characterized by TGA, DSC, SEM, SEC and AFM techniques. TGA analysis results of compounds showed considerable increasing of the thermal stability of polymers, because of finding of azomethine bond in the main chain.