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Öğe 2-(2,6-di-tert-butyl-4-methylphenoxy)-2,4,4,6,6,8,8-heptachlorocyclo-2 lambda(5),4 lambda(5),6 lambda(5),8 lambda(5)-tetraphosphazatetraene(Munksgaard Int Publ Ltd, 1996) Hokelek, T; Kilic, A; Begec, S; Kilic, Z; Yildiz, MThe title compound, C15H23Cl7N4OP4, consists Of a saddle-shaped cyclic tetrameric phosphazene ring and a bulky 2,6-di-tert-butyl-4-methylphenoxy side group. The bulky group substituent is instrumental in determining the molecular shape. The exo- and endocyclic angles about the P atoms both decrease on substitution whereas the P-N-P angles increase.Öğe A new model for tethered cord syndrome: A biochemical, electrophysiological, and electron microscopic study(Karger, 1997) Kocak, A; Kilic, A; Nurlu, G; Konan, A; Kilinc, K; Cirak, B; Colak, AIn order to investigate the pathophysiology of the tethered cord syndrome, a few experimental models have been developed and used previously. In this study, the authors present a new experimental model to investigate the biochemical, electrophysiological, and histopathological changes in the tethered spinal cord syndrome. A model was produced in guinea pigs using an application of cyanoacrylate to fixate the filum terminale and the surrounding tissue to the dorsal aspect of the sacrum following 5-gram stretching of the spinal cord. The experiments were performed on 40 animals divided into two groups. The responses to tethering were evaluated with hypoxanthine and lipid peroxidation, somatosensory and motor evoked potentials, and transmission electron microscope examination. The hypoxanthine and lipid peroxidation levels significantly increased, indicating an ischemic injury (p < 0.01). The average hypoxanthine level in the control group was 478.8 +/- 68.8 nmol/g wet tissue, while ii, was 651.2 +/- 71.5 nmol/g in the tethered cord group, The lipid peroxidation level in group I Nas 64.0 +/- 5.7 nmol/g wet tissue, whereas it Nas 84.0 +/- 4.7 nmol/g in group II. In the tethered cord group, the latencies of the somatosensory and motor evoked potentials significantly increased, and the amplitudes decreased. These changes indicated a defective conduction in the motor and sensorial nerve fibers. In the transmission electron microscopic examinations, besides the reversible changes like edema and destruction in the gray-white matter junction, irreversible changes like scarcity of neurofilaments and destruction in axons and damage in myelin sheaths were observed. We consider that this work can be used as an experimental model for tethered cord syndrome.Öğe Phenolysis of hexachlorocyclotriphosphazatriene(John Wiley & Sons Inc, 2005) Begec, S; Kilic, AThe reactions of hexachlorocyclotriphosphazatriene N3P3Cl6 (1) with the sodium salts of 2,4,6-trimethylphenol (2a), 4-tert-butyl-2methylphenol (2b), 2-tert-butyl-4-methylphenol (2c) have been investigated, and monoaryloxy-substituted phosphazenes N3P3Cl5OAr (3-5) were obtained. (c) 2005 Wiley Periodicals, Inc.Öğe The relationship between heart rate recovery and heart rate variability in coronary artery disease(Wiley, 2006) Evrengul, H; Tanriverdi, H; Kose, S; Amasyali, B; Kilic, A; Celik, T; Turhan, HBackground: Reduced heart rate recovery (HRR) in coronary artery disease (CAD) is predictive of increased cardiovascular mortality and is related to reduced parasympathetic tonus. Objective: To investigate HRR and heart rate variability (HRV) measured at steady state condition and the relationship between these two parameters in CAD. Materials and Methods: In our study, we enrolled 33 (28 males, mean age 52.4 +/- 9.6 years) patients with CAD who did not have heart failure, atrial fibrillation, pacemaker, and any disease state that could affect the autonomic functions and 38 age-matched healthy subjects (21 males, mean age 48.3 +/- 7.8 years). All the patients underwent submaximal treadmill exercise testing (Bruce protocol). HRR was calculated by subtracting the heart rate values at the 1st, 2nd, and 3rd minutes of the recovery phase from the peak heart rate (HRR1, HRR2, HRR3). Before exercise testing, short-term steady state HRV analyses of all subjects were obtained with the time- and frequency-domain methods and were correlated to HRR. For frequency-domain analysis, low-frequency HRV (LF, 0.004-0.15 Hz), high-frequency HRV (HF, 0.15-0.5 Hz), and LF/HF ratio were measured for 5 minutes in the morning. For time-domain analysis, standard deviation of the normal-to-normal NN intervals (SDNN), square root of the mean squared differences of successive N-N intervals (RMSSD), and proportion derived by dividing the number of interval differences of successive N-N intervals greater than 50 ms by the total number of N-N intervals (pNN50) were obtained. Only HRR3 was used for the correlation analysis. Results: In CAD groups, the HF, an indicator of parasympathetic activation, was significantly reduced, whereas the LF and LF/HF values, which are indicators of sympathetic activity, were increased (P = 0.0001 for each parameter). The time-domain parameters SDNN, RMSSD, and pNN50 were significantly reduced in the patient group (P = 0.0001, P = 0.009, and P = 0.0001, respectively). Similar to the HRV parameters, the HRR1, HRR2, and HRR3 values were significantly reduced in the patient group (P = 0.0001 for each parameter). We observed a significant negative correlation between HRR3 and LF (r =-0.67, P = 0.0001) and between HRR3 and LF/HF (r =-0.62, P < 0.0001), while there was a significant positive correlation between HRR3 and HF, SDNN, RMSSD, and pNN50 (r = 0.69, P = 0.0001; r = 0.41, P = 0.0001; r = 0.31, P = 0.008; and r = 0.44, P = 0.0001). Conclusions: HRR and HRV are significantly reduced in CAD. The reduction in HRR is parallel to the changes in HRV parameters. HRR, which can be measured easily in the recovery phase of exercise testing, can be used to detect the depression of parasympathetic tonus and to evaluate the basal autonomic balance in this patient group.Öğe Unusual products in the reactions of hexachlorocyclotriphosphazatriene with sodium aryloxides(Wiley, 1996) Kilic, A; Begec, S; Cetinkaya, B; Hokelek, T; Kilic, Z; Gunduz, N; Yildiz, MReactions of hexachlorocyclotriphosphazatriene, N3P3Cl6 1, with sodium aryloxides have been studied. Compound 1 was found to react by the nucleophilic substitution path way to yield monocyclophosphazenes [N3P3Cl5(OC(6)H(2)Bu(3)(t)-2, 4, 6) 5 and N3P3Cl4(OC(6)H(2)Me-4-Bu(2)(t)-2, 6)(2) 6] and bi(cyclophosphazenes) ([Cl5N3P3-P3N3Cl4(OC(6)H(3)Bu(2)(t)-2, 6)] 7 and [N3P3(OC(6)H(3)Bu(2)(t)-2, 6)(5)](2) 8]. The unusual bi(cyclophosphazenes) 7 and 8 are the first examples of two cyclotriphosphazene rings linked by a P-P bond [2.193 (2) Angstrom], which have been obtained by reacting 1 with ArONa. The structures of compounds 5-8 ave ascertained by elemental analyses, H-1-, P-31-C-13-NMR, IR, and MS spectra. The molecular structure of monocyclic-phosphazene 5 was determined by X-ray diffraction techniques for further structural assignment. It crystallizes in the monoclinic space group P2(1)/m with a = 6.144(2), b = 17.079(9), c = 13.181(9) Angstrom, beta = 92.79(7), and Z = 2, R = 0.074. Compound 5 is on a crystallographic mirror plane, and there is only a half molecule in the asymmetric unit. (C) 1996 John Wiley & Sons, Inc.
