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1.
Hilal Goktas Dogan Mansuroglu Betul Atalay Sinan Bilikmen Ismet Kaya 《Plasma Chemistry and Plasma Processing》2012,32(1):35-44
The synthesis of polyfluorene (PF) thin films by simultaneously superposing a continuous and pulsed discharge and the characterizations
of these samples are presented. The double discharge plasma system is constructed by superposing two discharges; namely, a
low pressure dc glow one and a high current pulsed one. The fluorene monomer in powder form was vaporized in the system at
argon plasma without any modification, at 0.5 mbar operating pressure. The structure of the thin films was investigated via
XPS, UV–visible, FTIR, XRD and SEM. The FTIR and the UV–visible results revealed that the fluorene structure was retained
at the produced samples. Semi-conducting behavior was established, and upon the iodine doping, the optical energy band gap
(E
g
) dropped down from 3.7 to 2.4 eV. The morphology of the synthesized PF thin films was amorphous, with granular structures
of different sizes depending on the location of the substrate. 相似文献
2.
Development and validation of an LC‐MS/MS method for simultaneous quantitative analysis of free and conjugated bisphenol A in human urine 下载免费PDF全文
Dilek Battal Ismet Cok Irfan Unlusayin Bahar Tunctan 《Biomedical chromatography : BMC》2014,28(5):686-693
Bisphenol A (BPA) is an environmental endocrine‐disrupting chemicals that is widely used in common consumer products. There is an increasing concern regarding human exposure to BPA owing to the potential adverse effects associated with its estrogenic activity. For assessing environmental exposure to BPA, it is essential to have a sensitive, accurate and selective analytical method, especially one that can detect low BPA levels in complex sample matrices. In this study, we developed and validated an accurate, sensitive, and robust liquid chromatography–tandem mass spectrometry method for simultaneous quantification of free BPA and BPA β‐d ‐glucuronide (BPA‐gluc) concentrations in human urine with only a single injection. Calibration curves were linear over a concentration range of 1–100 ng/mL for BPA and 10–1000 ng/mL for BPA‐gluc. The levels of the analytes were determined quantitatively with HPLC/ESI‐MS/MS by using negative electrospray ionization in the select ion monitoring mode and a pentaflouraphenyl propyl column. The validated method was applied to the analysis of spot urine specimens collected from randomly selected healthy human subjects. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
3.
The aerodynamics of thin, flat-plate wings of various planforms (rectangular, elliptical and Zimmerman) have been studied
in free-to-roll experiments in a wind tunnel. Non-zero trim angles at low angles of attack, self-induced roll oscillations
with increasing angle of attack and even autorotation in some cases were observed. The rectangular wings with round leading-edge
had non-zero trim angles at low incidences due to the asymmetric development of the three-dimensional separation bubble at
these low Reynolds numbers. With increasing angle of attack, the bubble increases in length and once reattachment is lost,
large amplitude roll oscillations develop. The Strouhal number of the roll oscillations is of the order of 10−2, which is in the same range as those expected for small aircraft experiencing atmospheric gusts. Velocity measurements revealed
that variations in the strength of the vortices drove the rolling motion. At the mean roll angle, because of the time lag
in the strength of the vortices, an asymmetric flow is generated, which results in a net rolling moment in the direction of
the rolling motion. 相似文献
4.
The Ni(II), Cu(II) Co(II) and Zn(II) complexes of 2,3‐hydroxyimino‐4‐phenyl‐6‐phenyazo‐1‐thia‐4,5‐diaza‐ cyclohexa‐5‐diene (H2L) were synthesized. Thermal behavior of these complexes was studied in dynamic nitrogen atmosphere by TA (thermogravimetric analysis), DTA (differential thermal analysis) and DTG (differential thermal gravimetry) techniques. The reaction order, the activation energies, the entropies, the enthalpies, the free energies, and the pre‐exponential factors of the thermal decomposition reactions were calculated from the thermogravimetric curves. The kinetic analysis of the thermogravimetric data was performed by using several methods such as MacCallum‐Tanner (MT), van Krevelen (vK), Madhusudanan‐Krishnan‐Ninan (MKN), Wanjun‐Yuwen‐Hen‐Cunxin (WYHC), Horowitz‐Metzger (HM) and Coats‐Redfern method (CR) based on the single heating rate. Most appropriate methods were determined for each decomposition step according to the least‐square linear regression. The Ni(II), Cu(II) Co(II) and Zn(II) complexes displayed one‐ or two‐stage decomposition pattern when heating in a dynamic nitrogen atmosphere and metal oxides remained as end products of the complexes. The characterization of the end products of the decomposition was performed by X‐ray diffraction. 相似文献
5.
Duygu Ayyildiz-Tamis Ayse Nalbantsoy Murat Elibol Saime Ismet Deliloglu-Gurhan 《Applied biochemistry and biotechnology》2014,172(1):224-236
In this study, different cultivation systems such as roller bottles (RB), 5-L stirred-tank bioreactor (STR), and disposable bioreactors were used to cultivate hybridoma for lab-scale production of Salmonella Enteritidis O-antigen-specific monoclonal antibody (MAb). Hybridoma cell line was cultivated in either serum-containing or serum-free medium (SFM) culture conditions. In STR, MAb production scaled up to 4 L, and production capabilities of the cells were also evaluated in different featured production systems. Moreover, the growth parameters of the cells in all production systems such as glucose consumption, lactate and ammonia production, and also MAb productivities were determined. Collected supernatants from the reactors were concentrated by a cross-flow filtration system. In conclusion, cells were not adapted to SFM in RB and STR. Therefore, less MAb titer in both STR and RB systems with SFM was observed compared to the cultures containing fetal bovine serum-supplemented medium. A higher MAb titer was gained in the membrane-aerated system compared to those in STR and RB. Although the highest MAb titer was obtained in the static membrane bioreactor system, the highest productivity was obtained in STR operated in semicontinuous mode with overlay aeration. 相似文献
6.
7.
Mahmut Erzengin Ismet Basaran Umit Cakir Aynur Aybey Selma Sinan 《Applied biochemistry and biotechnology》2012,168(6):1540-1548
Human serum paraoxonase 1 (PON1; EC 3.1.8.1) is a high-density lipoprotein associated, calcium-dependent enzyme that hydrolyses aromatic esters, organophosphates and lactones and can protect the low-density lipoprotein against oxidation. In this study, in vitro inhibition effect of some dihydroxy coumarin compounds namely 6,7-dihydroxy-3-(2-methylphenyl)-2H-chromen-2-one (A), 6,7-dihydroxy-3-(3-methylphenyl)-2H-chromen-2-one (B) and 6,7-dihydroxy-3-(4-methylphenyl)-2H-chromen-2-one (C) on purified PON1 were investigated by using paraoxon as a substrate. PON1 was purified using two-step procedures, namely ammonium sulphate precipitation and Sepharose-4B-l-tyrosine-1-naphthylamine hydrophobic interaction chromatography. The purified enzyme had a specific activity of 11.76?U/mg. The dihydroxy coumarin derivatives of A and B compounds inhibited PON1 enzyme activity in a noncompetitive inhibition manner with K i of 0.0080?±?0.256 and 0.0003?±?0.018?mM values, respectively. C compound exerted an uncompetitive inhibition of PON1 enzyme activity with K i of 0.0010?±?0.173?mM. Moreover, dihydroxy coumarin derivatives of A, B and C compounds were effective inhibitors on purified human serum PON1 activity with IC50 of 0.012, 0.022 and 0.003?mM values, respectively. IC50 value of unsubstituted 6,7 dihydroxy coumarin was found as 0.178?mM. The present study has demonstrated that PON1 activity is very highly sensitive to studied coumarin derivatives. 相似文献
8.
Four new trinuclear Fe(III) complexes involving tetradenta Schiff bases N,N
1
-bis(salicylidene) ethylenediamine-(salenH2) or bis(salicylidene)-o-phenylenediamine-(salophH2) with 2,4,6-tris(2,5-dicarboxyphenylimino-4-formylphenoxy)-1,3,5-triazine (DCPI-TRIPOD) or 2,4,6-tris(4-carboxyphenylimino-4′-formylphenoxy)-1,3,5-triazine (CPI-TRIPOD) have been synthesized and characterized by means of elemental
analysis carrying out 1H-n.m.r., i.r. spectroscopy, thermal analyses and magnetic susceptibility measurements. The complexes can also be characterized
as high-spin distorted octahedral FeIII bridged by carboxylic acids. The tricarboxylic acids play a role as bridges for weak antiferromagnetic intramolecular exchange. 相似文献
9.
H. Ibrahim Ugras Ismet Basaran Turgut Kilic Umit Cakir 《Journal of heterocyclic chemistry》2006,43(6):1679-1684
A new macrocyclic ligand, L was synthesized using the high dilution condition with condensation of triethylene glycol diamine and terephtalaldehyde in ethanol. The obtained product, L was identified by FT‐IR, 1H‐NMR, 13C‐NMR and Mass spectroscopy. The extraction equilibrium constants were estimated using dichloromethane/water membranes transfer with ICP‐AES and AES spectroscopy. Biological studies of this compound was determinated with disc diffusion method. The biological activity results showed that the synthesized ligand L has high activity against the studied microorganisms and high complexation ability against the Fe2+ cation. 相似文献
10.
Ismet Karaca 《Transactions of the American Mathematical Society》1999,351(2):547-558
K. G. Monks has recently shown that the element has nilpotence height in the mod Steenrod algebra. Here the method and result are generalized to show that for an odd prime the element has nilpotence height in the mod Steenrod algebra.