Recombination laser-assisted

Luntz and co-workers have recently carried out an impressive study that follows in the spirit of the Eley-Rideal work.44 Specifically, laser-assisted recombination of N-atoms desorbing to form gas-phase N2 on Ru(0001) was investigated. Experimental measurements of state-selectively detected N2 recoiling from the surface recombination event were obtained using resonance enhanced multiphoton ionization and ion time-of-flight methods. In this way translational energy distributions of individual rovibrational states could be obtained experimentally. In addition, N2-vibrational population distributions could be derived. 

Direct laser-assisted myocardial revascularization (DMR) is an approved technique in the US, Europe, and parts of Asia to create numerous myocardial channels. This results in the induction of a massive inflammatory reaction, which in turn induces angiogenesis. The other FDA-approved pro-angiogenic therapy is the use of recombinant human platelet-derived growth factor (Regranex) for use in the treatment of diabetic neuropathic foot ulcer s. 

The conclusion that can be drawn from the experiments just discussed is that, except for the very small particles, the photoluminescence of our Si nanocrystals, which are produced by CO2 laser-assisted pyrolysis of silane and which are gently oxidized in air under normal conditions, can be perfectly explained on the basis of the quantum confinement model, that is, by the radiative recombination of electron-hole pairs confined in the nanocrystals [15]. In order to obtain high quantum yields, the nanoparticles must be defect-free in particular, they must be perfectly monocrystalline and all dangling bonds must be passivated, for example by a silicon oxide layer. Indeed, high-resolution electron microscopy (HREM) studies have shown that our Si nanoparticles are composed of a perfect diamond-phase crystalline core and a surrounding layer of SiO [19]. 

Parker, C. E. Papac, D. L Tomer, K. B. Monitoring cleavage of fusion protein by matrix-assisted laser desorption ionization/mass spectrometry Recombinant HIV-1IIIB p26. Anal. Biochem. 1996, 239, 25-34. 

Jebanathirajah, J. A. Andersen, S. Blagoev, B. Roepstorff, P. A rapid screening method to monitor expression of recombinant proteins from various prokaryotic and eukaryotic expression systems using matrix-assisted laser desorption ioniza-tion-time-of-flight mass spectrometry. Anal. Biochem. 2002, 305, 242-250. 

Zhou, G. H., Luo, G. A., Zhou, Y, Zhou, K. Y, Zhang, X. D., and Huang, L. Q. (1998). Application of capillary electrophoresis, liquid chromatography, electrospray mass spectrometry and matrix-assisted laser desorption/ionization time of flight mass spectrometry to the characterization of recombinant human erythropoietin. Electrophoresis 19, 2348—2355. 

Chakel, J. A., Erno, J., Hancock, W. S., and Swedberg, S. A. (1997). Analysis of recombinant DNA-derived glycoproteins via high-performance capillary electrophoresis coupled with off-line matrix-assisted laser desorption ionization time-of-fiight mass spectrometry. /. Chromatogr. B 689, 215—220. 

Fig. 1.16 Mass spectra of a recombinant protein obtained by (A) matrix assisted laser desorption ionization-time of flight, (B) electrospray-quadrupole time of flight, cps Counts per second.

A. Tsarbopoulos, M. Karas, K. Strupat, B. N. Pramanlk, T. L. Nagabhushan, and F. Hillen-kamp, Comparative mapping of recombinant proteins and glycoproteins by plasma desorption and matrix-assisted laser desorption/ionization mass-spectrometry, Anal. Chem., 66 (1994) 2062-2070. 

Lazar AC, Kloczewiak MA, Mazsaroff I (2004), Matrix-assisted laser desorption/ ionization mass spectrometry for the evaluation of the C-terminal lysine distribution of a recombinant monoclonal antibody, Rapid Commun. Mass Spectrom. 18 239-244. 

Correct mass of purified proteins is determined using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF). N-terminal sequencing and/ or LC-ES-MS can verify correct amino acid sequence. Folding of the recombinant protein should be compared to the natural counterpart by measuring CD-spectra. Furthermore, nuclear magnetic resonance (NMR) analysis can be performed to ensure the presence of tertiary structure, important for IgE binding activity (Neudecker et al. 2003). 

Flensburg, J. and Belew, M. (2003) Characterization of recombinant human serum albumin using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. 

Y. H. Liu, G. Vellekamp, G. Chen, U. A. Mirza, D. WyUe, B. Twarowska, J. T. Tang, F. W. Porter, S. Wang, T. L. Nagabhushan, and B. N. Pramanik, Proteomic study of recombinant adenovirus 5 encoding hmnan p53 by matrix-assisted laser desorp-tion/ionization mass spectrometry in combination with database search, Int. J. Mass Spectrom. 226 (2003), 55-69. 

Recombinant wild type hIL-ip, the K138C mutant and the K138C, R4A, L6A triple mutant (mutant 1) were isolated from the soluble fraction of E. coli lysates by ammonium sulfate fractionation and hydrophobic interaction chromatography. The purified proteins were characterized by SDS-PAGE, western blots, N-terminal sequence, size exclusion chromatography (SEC), isoelectric focusing (lEF), matrix assisted laser desorption ionization mass spectrometry (MALDI-MS), and electrospray mass spectrometry (ESMS). 

LC under critical conditions of adsorption (LACCC) and SEC methods with matrix-assisted laser desorption/ioniza-tion-time-of-flight spectrometry (MALDI-TOF) and postcolumn derivatization. The critical conditions of polymer adsorption in the LC and an optimal matrix system for MALDI-TOF are reported. The changes of molar mass distribution and chemical heterogeneity are said to be due to the simultaneous processes of degradation and recombination. ... 

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