The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Hartmut Schlüter - One of the best experts on this subject based on the ideXlab platform.
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Sampling of Tissues with Laser Ablation for Proteomics: Comparison of Picosecond Infrared Laser and Microsecond Infrared Laser
Journal of proteome research, 2019Co-Authors: A. Krutilin, Stephanie Maier, Raphael Schuster, Sebastian Kruber, Marcel Kwiatkowski, Wesley D. Robertson, R.j.d. Miller, Nils-owe Hansen, Hartmut SchlüterAbstract:It was recently shown that sampling of tissues with a picosecond Infrared Laser (PIRL) for analysis with bottom-up proteomics is advantageous compared to mechanical homogenization. Because the cold ablation of tissues with PIRL irradiation is soft, proteins remain intact and even enzymatic activities are detectable in PIRL homogenates. In contrast, it was observed that irradiation of tissues with a microsecond Infrared Laser (MIRL) heats the tissue, thereby causing significant damage. In this study, we investigated the question if sampling of tissues with a MIRL for analysis of their proteomes via bottom-up proteomics is possible and how the results are different from sampling of tissues with a PIRL. Comparison of the proteomes of the MIRL and PIRL tissue homogenates showed that the yield of proteins identified by bottom-up proteomics was larger in PIRL homogenates of liver tissue, whereas the yield was higher in MIRL homogenates of muscle tissue, which has a significantly higher content of connective tissue than liver tissue. In the PIRL homogenate of renal tissue, enzymatic activities were detectable, whereas in the corresponding MIRL homogenate, enzymatic activities were absent. In conclusion, MIRL and PIRL pulses are suited for sampling tissues for bottom-up proteomics. If it is important for bottom-up proteomic investigations to inactivate enzymatic activities already in the tissue before its ablation, MIRL tissue sampling is an option, because the proteins in the tissues are denatured and inactivated by the heating of the tissue during irradiation with MIRL irradiation prior to the ablation of the tissue. This heating effect is absent during irradiation of tissue with a PIRL; therefore, sampling of tissues with a PIRL is a choice for purifying enzymes, because their activities are maintained.
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Sampling of Tissues with Laser Ablation for bottom-up Proteomics: Comparison of Picosecond Infrared Laser (PIRL) and Microsecond Infrared Laser (MIRL)
2018Co-Authors: A. Krutilin, Stephanie Maier, Raphael Schuster, Sebastian Kruber, Marcel Kwiatkowski, Wesley D. Robertson, R.j.d. Miller, Hartmut SchlüterAbstract:The analysis of proteomes directly from tissues requires the proteins to be released from the cells and their compartments and solubilized, which usually is achieved by mechanical homogenization. It was recently shown, that sampling of tissues with the novel picosecond Infrared Laser (PIRL) offers higher yields of proteins with respect to the total amount and total number of individual proteins in comparison to mechanical homogenization. Furthermore, proteins obtained from tissues by homogenization with PIRL are significantly less enzymatically degraded, giving improved access to the original composition of proteoforms. The effective cold vaporization of tissue with PIRL is very soft, which is responsible for the phenomenon, that even enzymatic activities of proteins in the tissue aerosol are maintained. In contrast, the energy following irradiation of tissue with microsecond Infrared Laser (MIRL) pulses is not thermally and acoustically confined to the ablated volume. In this study, PIRL (1 J·cm-2) and MIRL (40-60 J·cm-2) were compared for sampling different tissue types for bottom-up proteomics. We showed that PIRL at low fluence is optimal for soft tissue and desired in scenarios were enzymatic activities of proteins must be maintained as well as were no residual tissue damage is a requirement. MIRL could be well suited for scenarios were enzymatic activities must be suppressed within the intact tissue and thermal and acoustic damage is not a concern.<br>
Adenilson De Souza Da Fonseca - One of the best experts on this subject based on the ideXlab platform.
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DNA repair in bacterial cultures and plasmid DNA exposed to Infrared Laser for treatment of pain
Laser Physics Letters, 2013Co-Authors: K S Canuto, Luiz Philippe Da Silva Sergio, Roberta Da Silva Marciano, Giovanni Augusto Castanheira Polignano, Flavia De Paoli, Mauro Geller, Oscar Roberto Guimarães, Adenilson De Souza Da FonsecaAbstract:Biostimulation of tissues by low intensity Lasers has been described on a photobiological basis and clinical protocols are recommended for treatment of various diseases, but their effects on DNA are controversial. The objective of this work was to evaluate effects of low intensity Infrared Laser exposure on survival and bacterial filamentation in Escherichia coli cultures, and induction of DNA lesions in bacterial plasmids. In E. coli cultures and plasmids exposed to an Infrared Laser at fluences used to treat pain, bacterial survival and filamentation and DNA lesions in plasmids were evaluated by electrophoretic profile. Data indicate that the Infrared Laser (i) increases survival of E. coli wild type in 24 h of stationary growth phase, (ii) induces bacterial filamentation, (iii) does not alter topological forms of plasmids and (iv) does not alter the electrophoretic profile of plasmids incubated with exonuclease III or formamidopyrimidine DNA glycosylase. A low intensity Infrared Laser at the therapeutic fluences used to treat pain can alter survival of E. coli wild type, induce filamentation in bacterial cells, depending on physiologic conditions and DNA repair, and induce DNA lesions other than single or double DNA strand breaks or alkali-labile sites, which are not targeted by exonuclease III or formamidopyrimidine DNA glycosylase.
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Low intensity Infrared Laser effects on Escherichia coli cultures and plasmid DNA
Laser Physics, 2012Co-Authors: Adenilson De Souza Da Fonseca, Giuseppe Antonio Presta, A. F. Teixeira, Samuel Santos Valença, Mauro Geller, Flavia De PaoliAbstract:Biostimulative effect of low intensity Laser in tissues has been described on a photobiological basis and clinical protocols are recommended for treatment of various diseases. The aim of this work was to evaluate effects of Laser exposure on the survival of Escherichia coli cultures and plasmid topological forms. Escherichia coli cultures and plasmids were exposed to Infrared Laser to study bacterial survival and electrophoretic profile, respectively. Data indicate low intensity Infrared Laser: (i) had no effect on E. coli wild type, endonuclease IV, exonuclease III, formamidopyrimidine DNA glycosylase/MutM protein and endonuclease III deficient cultures, but decreased the survival of E. coli UvrA protein deficient cultures; (ii) there was no alteration in the electrophoretic profile of plasmids. Exposure to low intensity Infrared Laser decreases survival of Escherichia coli cultures deficient in nucleotide excision repair of DNA and this effect could depend on fluences, wavelength and tissues conditions.
Kyungha Hong - One of the best experts on this subject based on the ideXlab platform.
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optimal generation of high harmonics in the water window region by synthesizing 800 nm and mid Infrared Laser pulses
Optics Letters, 2015Co-Authors: Kyungha HongAbstract:We propose a method to optimally synthesize a strong 800-nm Ti:sapphire Laser pulse and a relatively weak mid-Infrared Laser pulse to enhance harmonic yields in the water-window region. The required wavelength of the mid-Infrared Laser is varied from about 2.0 to 3.2 μm. The optimized waveforms generate comparable harmonic yields as the waveforms proposed in [Sci. Rep.4, 7067 (2014)], but with much weaker intensity for the mid-Infrared Laser. This method provides an alternative scheme based on the available Laser technology to help realize tabletop light source in the water-window region by high-order harmonic generation.
A. Krutilin - One of the best experts on this subject based on the ideXlab platform.
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Sampling of Tissues with Laser Ablation for Proteomics: Comparison of Picosecond Infrared Laser and Microsecond Infrared Laser
Journal of proteome research, 2019Co-Authors: A. Krutilin, Stephanie Maier, Raphael Schuster, Sebastian Kruber, Marcel Kwiatkowski, Wesley D. Robertson, R.j.d. Miller, Nils-owe Hansen, Hartmut SchlüterAbstract:It was recently shown that sampling of tissues with a picosecond Infrared Laser (PIRL) for analysis with bottom-up proteomics is advantageous compared to mechanical homogenization. Because the cold ablation of tissues with PIRL irradiation is soft, proteins remain intact and even enzymatic activities are detectable in PIRL homogenates. In contrast, it was observed that irradiation of tissues with a microsecond Infrared Laser (MIRL) heats the tissue, thereby causing significant damage. In this study, we investigated the question if sampling of tissues with a MIRL for analysis of their proteomes via bottom-up proteomics is possible and how the results are different from sampling of tissues with a PIRL. Comparison of the proteomes of the MIRL and PIRL tissue homogenates showed that the yield of proteins identified by bottom-up proteomics was larger in PIRL homogenates of liver tissue, whereas the yield was higher in MIRL homogenates of muscle tissue, which has a significantly higher content of connective tissue than liver tissue. In the PIRL homogenate of renal tissue, enzymatic activities were detectable, whereas in the corresponding MIRL homogenate, enzymatic activities were absent. In conclusion, MIRL and PIRL pulses are suited for sampling tissues for bottom-up proteomics. If it is important for bottom-up proteomic investigations to inactivate enzymatic activities already in the tissue before its ablation, MIRL tissue sampling is an option, because the proteins in the tissues are denatured and inactivated by the heating of the tissue during irradiation with MIRL irradiation prior to the ablation of the tissue. This heating effect is absent during irradiation of tissue with a PIRL; therefore, sampling of tissues with a PIRL is a choice for purifying enzymes, because their activities are maintained.
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Sampling of Tissues with Laser Ablation for bottom-up Proteomics: Comparison of Picosecond Infrared Laser (PIRL) and Microsecond Infrared Laser (MIRL)
2018Co-Authors: A. Krutilin, Stephanie Maier, Raphael Schuster, Sebastian Kruber, Marcel Kwiatkowski, Wesley D. Robertson, R.j.d. Miller, Hartmut SchlüterAbstract:The analysis of proteomes directly from tissues requires the proteins to be released from the cells and their compartments and solubilized, which usually is achieved by mechanical homogenization. It was recently shown, that sampling of tissues with the novel picosecond Infrared Laser (PIRL) offers higher yields of proteins with respect to the total amount and total number of individual proteins in comparison to mechanical homogenization. Furthermore, proteins obtained from tissues by homogenization with PIRL are significantly less enzymatically degraded, giving improved access to the original composition of proteoforms. The effective cold vaporization of tissue with PIRL is very soft, which is responsible for the phenomenon, that even enzymatic activities of proteins in the tissue aerosol are maintained. In contrast, the energy following irradiation of tissue with microsecond Infrared Laser (MIRL) pulses is not thermally and acoustically confined to the ablated volume. In this study, PIRL (1 J·cm-2) and MIRL (40-60 J·cm-2) were compared for sampling different tissue types for bottom-up proteomics. We showed that PIRL at low fluence is optimal for soft tissue and desired in scenarios were enzymatic activities of proteins must be maintained as well as were no residual tissue damage is a requirement. MIRL could be well suited for scenarios were enzymatic activities must be suppressed within the intact tissue and thermal and acoustic damage is not a concern.<br>
C. Hirose - One of the best experts on this subject based on the ideXlab platform.
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The applications of Infrared Laser pulses to surface vibrational spectroscopy
Applied Catalysis A: General, 1997Co-Authors: Kazunari Domen, C. HiroseAbstract:Abstract Several applications of Infrared Laser pulses to the study of the kinetics and dynamics of surface chemical reactions are briefly summarized. Specific emphasis is placed on results obtained by the authors' group using methods made possible by recent progress in the generation of intense and frequency-tunable Infrared Laser pulses. This progress has enabled us to carry out vibrational spectroscopic measurements of the species adsorbed on insulator materials as well as on metal surfaces, providing us with a unique and powerful tool for the study of surface reactions.