Süleyman Kavak - Academia.edu (original) (raw)

Papers by Süleyman Kavak

European Journal of Anaesthesiology, 2006

Acta Anaesthesiologica Scandinavica, 2007

Background: The aim of this study was to evaluate the characteristic features of the mechanical ... more Background: The aim of this study was to evaluate the characteristic features of the mechanical responses and membrane potential changes induced by remifentanil in human umbilical arteries (HUAs). The ionic mechanisms underlying the electrophysiological responses were pharmacologically assessed using two K+ channel blockers.Methods: Thirty-eight HUAs were obtained. Contraction–relaxation, membrane potential changes and electrical responses of the HUAs were recorded.Results: Remifentanil produced concentration-dependent relaxation in both endothelium-intact and endothelium-denuded HUA rings. Remifentanil produced a significantly greater relaxation response in intact than in denuded HUA rings. In endothelium-intact rings, pre-treatment with L-nitroarginine [Nw-NITRO-L-ARGININE (L-NO-ARG)] or indomethacin decreased the degree of remifentanil-induced relaxation. Remifentanil (10−9–10−6 mol/l) produced a transient concentration-dependent membrane hyperpolarization, which was not decreased by pre-treatment with L-NO-ARG or indomethacin. It also produced a small concentration-dependent hyperpolarization in the presence of charybdotoxin or tetraethylammonium.Conclusion: In both endothelium-intact and endothelium-denuded HUAs, remifentanil induces concentration-dependent vasorelaxation and simultaneously releases nitric oxide, prostaglandins and possibly an endothelium-derived hyperpolarizing factor. In addition, it produces hyperpolarization in a dose-dependent manner. Hyperpolarization induced by remifentanil involves the activation of Ca2+-dependent and Ca2+-independent potassium channels regulated by intracellular Ca2+.

This study was conducted to find out the effect of potassium fertilizer rate on yield, quality, d... more This study was conducted to find out the effect of potassium fertilizer rate on yield, quality, dry matter and mineral matter content of savoy cabbage in Ege Region. In the experiment 0-5-10-15-20 kg/da K 2 O fertilizer was applied. Unmarketable outer leaves, head diameter, head height, average head weight, yield, dry matter and mineral matter content were determined.

This research was conducted to determine the effect of phosphorus fertilization on yield, quality... more This research was conducted to determine the effect of phosphorus fertilization on yield, quality and mineral matter content in savoy cabbage. In the experiment 0-4-8-12-16 kg/da P 2 O 5 fertilizer was applied. After the harvest number of unmarketable outer leaves, head diameter, head height, average head weight, yield, dry matter and mineral matter content were determined in the experiment.

This research was carried out to determine the effects of different nitrogen sources on yield, qu... more This research was carried out to determine the effects of different nitrogen sources on yield, quality, mineral matters, nitrate and nitrite content in head lettuce. In this research calcium nitrate and ammonium sulfate fertilizers were applied as 0-5-10-15-20 kg N/da doses. As the plant quality characteristics; head weight, head diameter and height, number of discarded leaves, marketable head weight, number of leaves in marketable head and total yield were determined. Calcium nitrate doses significantly influenced on head weight, head diameter, height, marketable head weight and yield. The highest yield was determined 3531.4 kg/da in 15 kg N/da calcium nitrate dose. Moreover, ammonium sulfate doses significantly influenced on head weight, head diameter, number of discarded leaves, number of leaves in marketable head, marketable head weight and yield. The highest yield was determined as 3480.7 kg/da in 20 kg N/da ammonium sulfate doses.

Scientia Horticulturae, 2009

European Journal of Anaesthesiology, 2006

Acta Anaesthesiologica Scandinavica, 2007

Background: The aim of this study was to evaluate the characteristic features of the mechanical ... more Background: The aim of this study was to evaluate the characteristic features of the mechanical responses and membrane potential changes induced by remifentanil in human umbilical arteries (HUAs). The ionic mechanisms underlying the electrophysiological responses were pharmacologically assessed using two K+ channel blockers.Methods: Thirty-eight HUAs were obtained. Contraction–relaxation, membrane potential changes and electrical responses of the HUAs were recorded.Results: Remifentanil produced concentration-dependent relaxation in both endothelium-intact and endothelium-denuded HUA rings. Remifentanil produced a significantly greater relaxation response in intact than in denuded HUA rings. In endothelium-intact rings, pre-treatment with L-nitroarginine [Nw-NITRO-L-ARGININE (L-NO-ARG)] or indomethacin decreased the degree of remifentanil-induced relaxation. Remifentanil (10−9–10−6 mol/l) produced a transient concentration-dependent membrane hyperpolarization, which was not decreased by pre-treatment with L-NO-ARG or indomethacin. It also produced a small concentration-dependent hyperpolarization in the presence of charybdotoxin or tetraethylammonium.Conclusion: In both endothelium-intact and endothelium-denuded HUAs, remifentanil induces concentration-dependent vasorelaxation and simultaneously releases nitric oxide, prostaglandins and possibly an endothelium-derived hyperpolarizing factor. In addition, it produces hyperpolarization in a dose-dependent manner. Hyperpolarization induced by remifentanil involves the activation of Ca2+-dependent and Ca2+-independent potassium channels regulated by intracellular Ca2+.

This study was conducted to find out the effect of potassium fertilizer rate on yield, quality, d... more This study was conducted to find out the effect of potassium fertilizer rate on yield, quality, dry matter and mineral matter content of savoy cabbage in Ege Region. In the experiment 0-5-10-15-20 kg/da K 2 O fertilizer was applied. Unmarketable outer leaves, head diameter, head height, average head weight, yield, dry matter and mineral matter content were determined.

This research was conducted to determine the effect of phosphorus fertilization on yield, quality... more This research was conducted to determine the effect of phosphorus fertilization on yield, quality and mineral matter content in savoy cabbage. In the experiment 0-4-8-12-16 kg/da P 2 O 5 fertilizer was applied. After the harvest number of unmarketable outer leaves, head diameter, head height, average head weight, yield, dry matter and mineral matter content were determined in the experiment.

This research was carried out to determine the effects of different nitrogen sources on yield, qu... more This research was carried out to determine the effects of different nitrogen sources on yield, quality, mineral matters, nitrate and nitrite content in head lettuce. In this research calcium nitrate and ammonium sulfate fertilizers were applied as 0-5-10-15-20 kg N/da doses. As the plant quality characteristics; head weight, head diameter and height, number of discarded leaves, marketable head weight, number of leaves in marketable head and total yield were determined. Calcium nitrate doses significantly influenced on head weight, head diameter, height, marketable head weight and yield. The highest yield was determined 3531.4 kg/da in 15 kg N/da calcium nitrate dose. Moreover, ammonium sulfate doses significantly influenced on head weight, head diameter, number of discarded leaves, number of leaves in marketable head, marketable head weight and yield. The highest yield was determined as 3480.7 kg/da in 20 kg N/da ammonium sulfate doses.

Scientia Horticulturae, 2009