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101.
102.
MJ Lazaro AA Herod M Domin Y Zhuo CA Islas R Kandiyoti 《Rapid communications in mass spectrometry : RCM》1999,13(14):1401-1412
Three methods for determining a 'safe' estimate for high-mass limits of MALDI spectra of coal derived liquids were explored, using a sample of coal-tar pitch and its pyridine-insoluble fraction. Co-addition of increasing numbers of single-shot spectra (10, 30, 50 and 100 pulses) showed visually observable reductions in noise levels, consistent with robust and statistically meaningful signals. Three separate types of post-acquisition calculation were used to identify high-mass limits of the spectra. (i) A literature method indicated high-mass limits similar to those observed visually-as a shift from baseline at the highest masses, nearly 350 000 u for the coal tar pitch and about 390 000 u for its pyridine insoluble fraction. (ii) Comparing instrument signal with pre-selected multiples of the standard deviation, upper mass estimates of between 40-60 000 u for the coal-tar pitch and about 95 000 u for its pyridine-insoluble fraction were found. (iii) Calculation of the slope was used to identify 'lift-off' of the spectrum from baseline. The angle between the smoothed spectrum and the baseline was matched to a pre-selected value (e.g. 0.5 degrees and 1 degrees ). However, the arbitrary specification of the key parameter did not establish this last method on a firm basis. The choice of a criterion for estimating high-mass limits of MALDI spectra remains a semi-quantitative procedure; a reasonably conservative high-mass limit may be estimated by comparison of signal with five times the standard deviation. However, evaluation of size exclusion chromatograms of the present samples using polystyrene standards suggests that molecular mass distributions of pitch samples arrived at by MALDI mass spectrometry are, at least partly, determined by the limitations of available instruments. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
103.
Eda Korkmaz Erem Ahmetali Gknur Yaa Atmaca Hande Pekbelgin Karaolu Ali Erdomu Makbule Burkut Koak 《Monatshefte für Chemie / Chemical Monthly》2020,151(2):181-190
This study presents synthesis of novel peripherally tetrasubstituted Zn(II) and In(III) phthalocyanine complexes bearing 3,5-bis(trifluoromethyl)phenoxy groups. These phthalocyanines were characterized by performing elemental analysis, mass spectrometry, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and ultraviolet visible spectrophotometric techniques. Aggregation properties of the resulting phthalocyanines were studied in different concentrations of DMSO. Aggregation behavior of the newly synthesized phthalocyanines was investigated in various organic solvents, as well. Photochemical and photophysical characterization of the resulting compounds were carried out to evaluate their photodynamic therapy properties in DMSO. The new metallophthalocyanines have high singlet oxygen quantum yields ranging from 0.72 to 0.88. 相似文献
104.
Shaoguang Yang Yuxuan Xie Wenrong Yang Rongkun Zheng Frankie Stevens Emine Korkmaz Anthony S. Weiss Simon P. Ringer Filip Braet 《Micron (Oxford, England : 1993)》2009,40(4):476-479
The recent discovery of arsenic-based high temperature superconductors has reignited interest in the study of superconductor: biological interfaces. However, the new superconductor materials involve the chemistry of arsenic and their toxicity remains unclear [Hand, E., 2008. Nature 452 (24), 922]. In this study the possible adverse effects of this new family of superconductors on cells have been examined. Cell culture studies in conjunction with microscopy and viability assays were employed to examine the influence of arsenic-based superconductor PrOxFeAs (x = 0.75) material in vitro. Imaging data revealed that cells were well adhered and spread on the surface of the superconductor. Furthermore, cytotoxicity studies showed that cells were unaffected during the time-course of the experiments, providing support for the biocompatibility aspects of PrOxFeAs-based superconductor material. 相似文献
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109.
M.S. Osman Alper Korkmaz Hadi Rezazadeh Mohammad Mirzazadeh Mostafa Eslami Qin Zhou 《Chinese Journal of Physics (Taipei)》2018,56(5):2500-2506
The present study implements the unified method to the conformable time fractional non linear Schrdinger equation with perturbation terms. Reduction of the governing equation to a simpler ODE by compatible complex transform is the first step of the procedure. The predicted solutions in finite series forms of various functions satisfying some particular ODEs are substituted into the reduced form of the governing equation. The algebra is resulted in forming the explicit exact solutions in optical solitary, periodic, elliptic and soliton wave forms represented in polynomial or rational functions. 相似文献
110.
Nurten?Korkmaz Esin?HamuryudanEmail author 《Monatshefte für Chemie / Chemical Monthly》2004,135(5):513-518
Summary. Unsymmetrical metal-free and metalo-porphyrazines (M=Mg, Zn, Co) made up of three phthalonitrile units and a single maleonitrile moiety on the periphery were prepared by cyclization of bis(2-dimethylaminoethylthio)maleonitrile and phthalonitrile. The magnesium derivative (Mgpz) was converted into the quaternized product by reaction with methyl iodide. The new compounds were characterized by elemental analysis, IR, NMR, mass, and electronic spectra. 相似文献