9 sonuçlar
Arama Sonuçları
Listeleniyor 1 - 9 / 9
Öğe The effect of Plantago major Linnaeus on serum total sialic acid, lipid-bound sialic acid, some trace elements and minerals after administration of 7,12-dimethylbenz(a)anthracene in rats(SAGE, 2012-04) Oto, Gökhan; Ekin, Suat; Özdemir, Hülya; Levent, Abdulkadir; Berber, İsmetThe present study was designed to evaluate the effect of Plantago major Linnaeus (PM) extract on serum total sialic acid (TSA), lipid-bound sialic acid (LSA), some trace elements (copper (Cu), zinc (Zn) and iron) and mineral levels (magnesium, calcium and sodium) in Wistar albino rat administrated 7,12-dimethylbenz(a)anthracene (DMBA). Rats were divided into three equal groups (n = 6). Group I comprised the control group, group II was treated with DMBA (100 mg/kg, single dose) and group III was treated with DMBA (100 mg/kg single dose) and aqueous extract of PM 100 mg/kg/day for 60 days. After 60 days, statistical analyses showed that TSA and LSA levels in DMBA and DMBA + PM groups were significantly higher compared to the control group (TSA: p < 0.01, p < 0.05; LSA: p < 0.05, p < 0.05, respectively). Serum Zn levels were decreased in subjects treated with DMBA (p < 0.01) and DMBA + PM (p < 0.05) compared to the control group values. Serum Cu levels were increased in DMBA group and PM-treated group compared to the control group values. The results of this investigation showed that the levels of TSA and LSA changed significantly, which are sensitive markers for detecting the toxic effects of DMBA. On the other hand, observed decline in Zn levels in rats from DMBA + PM group might be due to decreased generation of free radicals and oxidative stress. Results from this study suggest that PM may be partially effective in preventing carcinogenesis initiated by environmental carcinogen DMBA.Öğe Plantago major protective effects on antioxidant status after administration of 7,12-dimethylbenz(a)anthracene in rats(Asian Pacific Organization for Cancer Prevention, 2011) Oto, Gökhan; Ekin, Suat; Özdemir, Hülya; Demir, Halit; Yaşar, Semih; Levent, Abdulkadir; Berber, İsmet; Kaki, BarışAim: The present study was designed to evaluate effects of Plantago major extract on oxidative status in Wistar albino rats administrated 7,12-dimethylbenz(a)anthracene (DMBA). Methods: Rats were divided into three equal groups of 6 animals each: Group 1 controls, group 2 treated with DMBA (100 mg/kg, single dose) and group 3 receiving the DMBA and the aqueous extract at 100 mg/kg/d for 60 days. Results: Significant decrease in catalase (P<0.05), carbonic anhydrase (p≤0.01), reduced glutathione (GSH) (P<0.01) and total protein (P<0.01) values was observed in the DMBA group compared with the healthy controls and DMBA + Plantago major groups. Conclusion: The results suggest preventive effects of Plantago major on DMBA induced oxidative damage in Wistar albino rats that might be due to decreased free radical generation.Öğe An experimentally investigation of usability of a blend of tallow methyl ester and diesel fuel substitution of diesel fuel in diesel engines(Gazi Üniversitesi, 2010-07-06) Aydın, Hüseyin; Altun, Şehmus; Öner, Cengiz; Yücel, Halit LutfiBiodiesel fuels is one of the most attractive alternative fuels to reduce both emissions and petroleum based fuel consumption resulted from diesel engines. Therefore, the effects of biodiesel fuels on long-term engine operation and deposits in engine are considerably important, when biodiesel was evaluated as the alternative fuel for diesel engines. In this study, a 100 h engine test was performed on a single cylinder diesel engine using diesel fuel and tallow methyl ester as biodiesel fuel in order to compare the effects of the fuels on engine operation and deposits. The biodiesel was blended with 80 vol% diesel fuel and 20 vol % tallow methyl ester. Also, short-term engine performance and emissions were investigated and compared using both fuels. The test engine was disassembled before and after the experiment to determine the difference and clean carbon deposits. Experimental results were similar for both fuels in long-term engine tests, and indicated that the engine was satisfactorily operated for 100 hours with blend fuel. Deposits in engine at the end of the 100 h test were comparable in amount, but slightly different in color and adhesive, with the blend fuel when compared with those of diesel fuel. Besides, the blend fuel was comparable with the performance of diesel fuel and the exhaust emissions were lower than that of diesel fuel. It is concluded at the results of engine tests; the blend fuel can be a suitable alternative fuel for diesel engines to substitute diesel.Öğe Ahmet Mithat Efendi’nin ilk romanlarında Mısır ve Mısırlılar(Atatürk Üniversitesi, 2011-06) Korkmaz, FerhatAhmet Mithat Efendi, Şemsettin Sami’den sonra ikinci telif romanı yazan Türk romancısıdır. Osmanlı Devleti açısından 18. Yüzyıldan itibaren başlayan Mısır sorunu, 19. Yüzyılda özellikle Kavalalı Mehmet Ali Paşa döneminde en karmaşık halini alır. 1517’de fethedilen; ancak 1882’de Osmanlı Devleti’nin elinden çıkan Mısır bu ilk romancılarımızın ilgisini çekmiş ve Tanzimat dönemi romanlarında bu ülkeye ait kimi konular işlenmiştir. Tanzimat romanında Mısır coğrafyası mekân olarak kullanılmış, roman yazarları ise romanlarının kimi bölümlerini Mısır, Mısırlılar veyahut Mısır’daki meselelere ayırmıştır. Ahmet Mithat Efendi de bir Tanzimat romancısı olarak Mısır konusuna bîgâne kalmamıştır. Onun romanlarını Osmanlı ülkesinin yaşayan halklarının siyasi, ekonomik, coğrafi, sosyal, psikolojik ve kültürel tarihi olarak değerlendirdiğimizden makalemizde, Ahmet Mithat Efendi’nin romanlarında Mısır coğrafyası ve Mısırlılar ele alınmıştırÖğe Electrical properties of safranine T p Si organic inorganic semiconductor devices(Cambridge University, 2010-04-25) Güllü, Ömer; Asubay, Sezai; Biber, Mehmet; Kılıçoğlu, Tahsin; Turut, AbdulmecitWe investigated the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of identically prepared safranine T/p-Si organic/inorganic Schottky devices (total 26 diodes) formed by evaporation of organic compound solution on p-Si semiconductor substrate. It was seen that the safranine T organic thin film on the p-Si substrate showed a good rectifying behavior. The barrier heights and ideality factors of all devices were extracted from the electrical characteristics. The mean barrier height and mean ideality factor from I-V measurements were calculated as 0.59±0.02 eV and 1.80±0.20, respectively. Also, the mean barrier height and mean acceptor doping concentration from C-V measurements were calculated as 0.67±0.10 eV and (6.96±0.37)×1014 cm-3, respectively. The discrepancy in the barrier height values obtained from I-V and C-V characteristics has been attributed to different nature of the measurements. The discrepancy between these values can also be due to the existence of the interfacial native oxide and the organic safranine T thin layer between the semiconductor substrate and top contact metal.Öğe Enantioselevtive compexation of chiral lariat crown ethers and chiral primary alkylamonum perchlorates(Turkish Journal Chemistry, 2011-02-01) Aral, Tarık; Köylü, Mehmet Zafer; Kocakaya, Şafak Özhan; Karakaplan, Mehmet; Hoşgören, HalilIn order to investigate the enantiomeric recognition abilities toward 2 chiral alkylammonium perchlorates (AmI, AmII) by 1 H-NMR titration method in CDCl 3, 4 chiral lariat ethers 8-11 with a (p-methoxyphenoxy) methyl flexible side arm were used. The most effective enantiomeric recognition was obtained by LCEs 9 and 11 toward AmII, by KR /KS 6.58 and KS /KR 6.63, respectively. The effect of macroring size, subunit of macroring, and side arm appeared to have strong influence on the binding ability of these alkylammonium ions.Öğe Experimental investigation of thermal performance in a concentric tube heat exchanger with wavy inner pipe(SpringerLink, 2012-06) Argunhan, Zeki; Çakmak, Gülşah; Yücel, Halit Lutfi; Yıldız, CengizIn this article, the heat transfer, friction factor, and thermal performance factor characteristics of a concentric-tube heat exchanger are examined experimentally. A wavy inner pipe is mounted in the tube with the purpose of generating swirl flow that would help to increase the heat transfer rate of the tube. The examination is performed for a Reynolds number ranging from 2700 to 8800. An empirical correlation is also formulated to match with experimental data of the Nusselt number using the Wilson plot method. In addition, to obtain the real benefits in using the swirl generator at a constant pumping power, the thermal enhancement factor is also determined. Over the range considered, the increases in the Nusselt number, friction factor, and thermal performance factor are found to be, respectively, about 113 %, 81 %, and 196 % higher than those obtained from a smooth-surface inner pipe.Öğe Determination of 7,12-dimethylbenz[a]anthracene in orally treated rats by high-performance liquid chromatography and transfer stripping voltammetry(Bentham, 2012-06) Yardım, Yavuz; Levent, Abdulkadir; Ekin, Suat; Keskin, Ertuğrul; Oto, Gökhan; Şentürk, ZühreA number of polycyclic aromatic hydrocarbons (PAHs) have been shown to be toxicants, and induce carcinogenic and immunotoxic effects. As a model PAH agent, 7,12-dimethylbenz[a]anthracene (DMBA) was the strongest one tested in terms of its biological activities and biotransformation. A new and simple high-performance liquid chromatographic (HPLC) method with diode-array detection at 290 nm was developed and validated for monitoring of DMBA in different matrices (serum, liver and kidney) of rats orally treated with DMBA. Furthermore, the applicability of adsorptive transfer stripping voltammetry (AdTSV) on the pencil-lead graphite electrode to these samples was illustrated using our previously reported data for bulk aqueous solutions of DMBA. HPLC and AdTSV methods, which were compatible with each other, allowed DMBA to be detected down to the levels of 3.82x10-9 M (0.98 ppb) and 6.73x10-9 M (1.73 ppb), respectively. Olive oil solutions of DMBA in dose 50 mg/kg were orally administered. 60 days after a single dose of DMBA, its concentrations in these biological samples from rats were measured by means of both methods. Because of rapid biotransformation, DMBA could not be detected in serum. Only low levels of the compounds were deposited unchanged in kidney whereas its levels were considerably higher in liver. These methods were also applied to the assay whether there is an influence of the intake of aqueous extracts of Hypericum Perforatum L. plant on the parent DMBA levels accumulated in rat tissues.Öğe Synthesis of some novel pyrimidine derivatives and investigation of their electrochemical behavior(Wiley-Blackwell, 2010-12-20) Akbaş, Esvet; Levent, Abdulkadir; Gümüş, Selçuk; Sümer, Mehmet Rauf; Akyazı, İnci2-Iminopyrimidines (1a-e) and 2-thioxopyrimidine (2) were synthesized using the Biginelli three component cyclocondensation reaction of an appropriate β-diketone, arylaldehyde, and guanidine (for 1a-e) or thiourea (for 2). The electrochemical properties of the novel systems were investigated by CV and DPV. Moreover, B3LYP/6-31G(d,p) method was applied to the present structures in order to gather some structural and physicochemical data
