1107 research outputs found
Sort by
Dark and illuminated electrical characteristics of Si-based photodiode interlayered with CuCo5S8 nanocrystals
No full textDerived from the traditional dichalcogenide CuS structure, ternary transition metal chalcogenide nanoparticles in the form of CuCo5S8 are investigated under the aim of photodiode application. In addition to the detailed analysis on material characteristics of CuCo5S8 thin-film layer, the work is focused on the electrical characteristics of Au/CuCo5S8/Si diode to investigate its current–voltage, capacitance–voltage, and conductance–voltage characteristics under dark and illuminated conditions. CuCo5S8 nanocrystals with an average size of 5 nm are obtained using hot-injection method, and they are used to form thin-film interfacial layer between metal (Au) and semiconductor (Si). Under dark conditions, the diodes show about four orders in magnitude rectification rate and diode illumination results in efficient rectification with increase in intensity. The analysis of current–voltage curve results in non-ideal diode characteristics according to the thermionic emission model due to the existence of series resistances and interface states with interface layer. The measured current–voltage values are used to extract the main diode parameters under dark and illumination conditions. Under illumination, photogenerated carriers contribute to the current flow and linear photoconductivity behavior in photocurrent measurements with illumination shows the possible use of CuCo5S8 layer in Si-based photodiodes. This characteristic is also observed from the typical on/off illumination switching behavior for the photodiodes in transient photocurrent, photocapacitance, and photoconductance measurements with a quick response to the illumination. The deviations from ideality are also discussed by means of distribution of interface states and series resistance depending on the applied frequency and bias voltage. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.217M212This study was supported by TUBITAK (The Scientific and Technological Research Council of Turkey) under Project Number 217M212. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations
Cholinesterases, ?-glycosidase, and carbonic anhydrase inhibition properties of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives: Synthetic analogues for the treatment of Alzheimer's disease and diabetes mellitus
No full textIn this study, using the Cu(OTf)2 catalyst, 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivative molecules were carried out in one step and with high yield (86–91%). The previously synthesized 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives, carbonic anhydrase I and II isozymes (hCA I and II), acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and ?-glycosidase (?-Gly) enzymes with Ki values in the range of 4.88–15.94 nM for hCA I, 7.04–20.83 nM for hCA II, 68.25–158.27 for AChE, 60.17–91.27 for BChE and 0.36–2.36 nM for ?-Gly, respectively. In silico studies were performed on the molecules inhibiting hCA I, hCA II, AChE, BChE and ?-Gly receptors. When we evaluated the data obtained in this work, we determined the inhibition type of the 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives at the receptors. Reference inhibitors were used for all enzymes. © 2020 Elsevier Inc.Yildiz Teknik Ã?niversitesiThe synthesis part of this study was supported by Yildiz Technical University Research Fund. Project Number: 2012-01-02-GEP01
Bimetallic palladium-cobalt nanomaterials as highly efficient catalysts for dehydrocoupling of dimethylamine borane
No full textIn this work, we report the synthesis, characterization and application of graphene oxide stabilized PdCo nanoparticles (PdCo@GO) for the dehydrocoupling of dimethylamine borane (DMAB) as a model reaction. Bimetallic graphene oxide stabilized PdCo nanoparticles were readily synthesized using an ultrasonic reduction technique, in which both metals of Pd and Co were reduced with GO. The dispersion of PdCo nanoparticles on the surface of GO was enhanced with the help of the ultrasonic reduction method which result in the enhancing of dispersion of both metals without any agglomeration problem. The characterization studies revealed that graphene oxide stabilized PdCo nanoparticles have a uniform, homogeneous distribution on graphene oxide and an average particle size of 3.48 ± 0.22 nm. After fully characterization of graphene oxide stabilized PdCo nanoparticles, they have been tried in model reaction as a catalyst and exhibited a high catalytic performance compared the previous catalysts in literature with a TOF value of 226.80 h-1. The investigation of kinetic parameters showed that graphene oxide stabilized PdCo nanoparticles have very high negative entropy (?S: -170.85 J mol-1 K-1) value and a low activation energy value (Ea: 17.53 ± 2 kJ mol-1) for the model reaction. © 2019 Hydrogen Energy Publications LLC2014-05The authors would like to thank Kutahya Dumlupinar University ( 2014-05 ) for financial support. Appendix
Influence of some ß-lactam drugs on selected antioxidant enzyme and lipid peroxidation levels in different rat tissues
No full textPubMed: 31060396Antioxidant enzymes play an important role in body defense and free radical removal. Cephalosporins are ß-lactam antibiotics. In this work, the effects of cefazolin, cefuroxime and cefoperazone which are cephalosporins on some selected antioxidant enzyme and levels of malondialdehyde (MDA) as lipid peroxidation product were investigated in kidney, liver, and brain tissues of albino female rats. Ninety-six albino rats were randomly divided into 16 groups of equal number (n = 6). 50 mg/kg cefazolin, 25 mg/kg cefuroxime, and 100 mg/kg cefoperazone were injected intraperitoneally to the groups (5th–8th and 9th–12th, and 13th–16th groups), respectively. The changes in glutathione reductase (GR), glutathione S-transferase (GST), superoxide dismutase (SOD), peroxidase (POD), and glutathione peroxidase (GSH-Px) levels were studied in each time point group and a time-dependent manner (at the 1st, 3rd, 5th and 7th hour). In addition, MDA levels were examined in all the tissues. The drugs evaluated in this study had different effects on the same enzyme in different tissues depending on time. MDA levels especially in cefazolin and cefoperazone experiments were lower in all the tissues; however, MDA levels were higher in brain and kidney tissues in the cefuroxime groups in a time-dependent manner (p < 0.05). These results revealed the complex effects of the tested drugs on different tissues at different time points. Therefore, the dose and use of these drugs should be adjusted correctly. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.2018-SBE-A11This study was supported by Scientific Research Fund of I?d?r University. Project Number: 2018-SBE-A11
An ethnobotanical research in Şanlıurfa central district and attached villages (Turkey)
No full textThe objective of present study is to identify the plants traditionally utilized by local communities, who reside at the rural areas attached to Central District of Şanlıurfa located in Southeast Anatolia Region, for various purposes, and to reveal the significant of such use in terms of ethnobotany. The study conducted in this respect identified 137 taxa of 87 genera from 47 families (86 species, 34 sub-species, and 17 varieties), 21 of them are cultigens. 1 taxon is from Terfeziaceae of Ascomycota division of Fungi kingdom, while the others are from Gymnospermae and Angiospermae sub-division of Spermatophyte division from the Plantae kingdom. In general, local community utilizes taxa identified in field of study as follows: 56 taxa as food, 37 as medicinal purposes, 5 for belief, 5 for pests, 4 as household goods, 3 as seasoning, 3 as ornaments, 3 as cosmetics, 2 as beverages, 2 as knick-knack, 2 as fuel, 2 as building materials, 1 as dulling, 1 as canopy, 1 as aphrodisiac, 1 as clarifying, 1 as repellent, 1 as doddle, 1 as preventive and 1 as aroma. Moreover, 11 taxa are not utilized, but 7 of them are known by their local names and 4 with their harmful effects. © 2020, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved.13152We hereby acknowledge Harran University Scientific Research Committee (Project No: 13152) for offering financial support and Hakkı Sazak, Survey Technician, for drawing the map of the study area
Changes in growth parameter and essential oil composition of sage (Salvia officinalis L.) leaves in response to various salt stresses
No full textSalt stress imposes major limitations on the growth, development, crop productivity, and quality in many regions of the world. Therefore, the studies concerned with salinity and its effects on plants are of the fundamental interests for agricultural issues. Herein, the present study was designed to investigate the effects of different salt compounds (NaCl, KCl, MgSO4, MgCl2, Na2SO4, and CaCl2) with different salinity levels (0, 50, 100, 150, and 200 mM) on growth and leaf essential composition of sage (Salvia officinalis L.). In this context, sage seedlings were irrigated with different salinity levels for forty-days. Concerning the composition, twenty-two compounds were collectively identified using gas-chromatography coupled with headspace system. Of those compounds (over 5% content), ?-pinene, camphene, 1, 8-cineole, ?-thujone, ß-thujone, and camphor are of the major compounds. Along with the study, ?-pinene and camphor percentages increased under all salt stress but depending concentration and salt compound. The percentage of camphene was also augmented under all stress types except CaCl2 treatment whereas ß-thujone percentage increased except MgCl2 treatment. Moreover, NaCl and KCl treatments decreased the percentage of ?-thujone while other treatments caused an increase in the percentage. 1,8-cineole percentage was not influenced by NaCl treatments. However, CaCl2 and MgCl2 treatments decreased the percentage of 1,8-cineole whereas other salt treatments increased the percentage of the compound. It should be emphasized that the degree and severity of the stress were also variable according to the treatments and compounds. Herewith the study, due to the high number of treatments and compounds identified, principal component analysis was applied to reduce, discriminate and identify the treatments according to their effects on essential components. The results were well clarified, visualized and discriminated according to the treatments. As a conclusion, the chemical composition of the common sage was found to be strongly affected by salt treatments and concentration of the salt compounds because each salt treatment with their concentration induced different new chemotypes in essential oil composition of common sage. The results also suggest the plausible role of metabolites in response to the changing environmental conditions. © 2019 Elsevier B.V
The effects of n-butanol on oxidative stress and apoptosis in zebra fish (Danio rerio) larvae
No full textPubMed: 31669665In recent years, n-butanol has growing use in many areas, including the food industry. In this study, acute toxic effects of n-butanol to zebrafish (Danio rerio) larvae by applying different concentrations (10, 50, 250, 500, 750, 1000 and 1250 mg/L) to embryos were evaluated. For this purpose the data of oxidative stress, antioxidant - acetyl cholinesterase enzyme activities, malondialdehyde level and apoptosis were taken into consideration. At the end of the 96 h, antioxidant (Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx)) and acetylcholinesterase (AChE) enzyme activities were decreased, however lipid peroxidation level, apoptotic cells, and reactive oxygen species increased (p < .05). As a result, it has been observed that high concentrations of n-butanol with its amphiphilic structure causes quite intense toxic effects in zebrafish embryos. © 2019 Elsevier Inc
Improved by potassium chloride (KCl) dilution predictive ability of attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to determine nutrient contents of sunflower meal
No full textWOS: 000487318800007Predctive ability of attenuated total reflectance (ATR) Fourier transform (FT) infrared (IR) spectroscopy to determine nutrient contents of sunflower meal (SFM) high in fibre and ash was investigated by testing the effect of potassium chloride (KCl) spiking. The partial least square regression (PLSR) models were generated using original IR spectrum, and its first and second derivate data followed by the normalisation, smoothing and multiplicative scatter correction in order to predict nutrient contents of spiked and non-spiked SFM samples. The results showed that the best model for the prediction was the one derived from the second derivate IR data with high degree of precision and accuracy (R-2 = 0.99, r(2) = 0.95, residual mean square error of cross-validation (RMSECV) = 0.66 for dry matter and 1.30 for crude ash). Furthermore, the precision and accuracy of all three models were improved by the KCl levels spiked at 27.5 and 57.0%, while no effects of further spiking with KCl was observed. In conclusion, the model generated from the second derivate IR data was highly recommended to predict the SFM nutrient contents, and the KCl dilution up to 57% improved the prediction accuracy and precision irrespective to the models used
The protective role of jervine against radiation-induced gastrointestinal toxicity
No full textPubMed: 30871382In this study, we investigated whether jervine (J) could prevent gastrointestinal (GI) side effects of abdominopelvic radiotherapy (RT) in Wistar-Albino female rats. Rats were divided into five groups: control (C), J only (J), J administered at 5 mg/kg/days for 7 days, RT only (RT), J before RT (J + RT), J administered for seven days before RT, J both before and after RT (J + RT + J), and J administered for 7 days before RT and after RT for 3 days. The weights of rats were measured on the 1st, 7th, and 10th days of the study. Rats were sacrificed to obtain tissues from the liver and intestine, which was followed by taking blood samples intracardially. In addition, the tissues were stained with pyruvate dehydrogenase (PDH) immunohistochemically. In our study, J supplementation markedly reduced weight loss, and histopathological, immunohistochemical, biochemical results suggest that J had a protective effect on GI toxicity following RT. © 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
Comparison of chemical, physical, and ultrasound treatments on the shelf life of fresh-cut quince fruit (Cydonia oblonga Mill.)
No full textThe study was conducted to examine the effect of chemical treatment (ascorbic acid and calcium chloride), physical treatment (water bath at 65 °C), and ultrasound (US) in ultrasonic bath for the prevention of enzymatic browning of fresh-cut quince slices during 14 days of storage. The treated quince slices were analyzed in terms of color, polyphenol oxidase, and pectin methyl esterase activity, bioactive compounds, sensory, and microbial analysis. The results showed that US treatment inhibited (p <.05) the growth of bacteria, mold, and yeast in fresh-cut quince slices during 4 °C storage. The US-treated slices showed a significant (p <.05) improvements in bioactive compounds as well as improved physical properties as compared to all other treatments. Similarly, US-treated samples showed the best color values with the lowest value of enzyme activities showing less enzymatic browning. Moreover, the findings showed that the lowest score for decay and off-odor were obtained for the quinces treated with US. Practical applications: A significant improvement in the quality of US-treated fresh-cut quinces with the comparison of other chemical and physical treatments was achieved. This study will contribute a novel method to develop US-treated fresh-cut fruit and vegetables with an enhanced product quality and extended shelf life. In overall, processing of fresh-cut quince fruit with a US treatment might be applied to get a high-quality and browning-free product. © 2019 Wiley Periodicals, Inc