Characterization of cell cultures with ToF-SIMS and laser-SNMS

2002 ◽  
Vol 34 (1) ◽  
pp. 63-66 ◽  
Author(s):  
M. Fartmann ◽  
S. Dambach ◽  
C. Kriegeskotte ◽  
H. P. Wiesmann ◽  
A. Wittig ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Tof Sims

scholarly journals Chemical Evaluation of Eumelanin Maturation by ToF-SIMS and Alkaline Peroxide Oxidation HPLC Analysis

2020 ◽  
Vol 22 (1) ◽  
pp. 161
Author(s):  
Martin Jarenmark ◽  
Peter Sjövall ◽  
Shosuke Ito ◽  
Kazumasa Wakamatsu ◽  
Johan Lindgren
Keyword(s):  
Molecular Structure ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Characterization ◽  
Experimental Treatment ◽  
Negative Ion ◽  
Pressure Treatment ◽  
Peroxide Oxidation ◽  
Specific Chemical ◽  
Tof Sims

Residual melanins have been detected in multimillion-year-old animal body fossils; however, confident identification and characterization of these natural pigments remain challenging due to loss of chemical signatures during diagenesis. Here, we simulate this post-burial process through artificial maturation experiments using three synthetic and one natural eumelanin exposed to mild (100 °C/100 bar) and harsh (250 °C/200 bar) environmental conditions, followed by chemical analysis employing alkaline hydrogen peroxide oxidation (AHPO) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Our results show that AHPO is sensitive to changes in the melanin molecular structure already during mild heat and pressure treatment (resulting, e.g., in increased C-C cross-linking), whereas harsh maturation leads to extensive loss of eumelanin-specific chemical markers. In contrast, negative-ion ToF-SIMS spectra are considerably less affected by mild maturation conditions, and eumelanin-specific features remain even after harsh treatment. Detailed analysis of ToF-SIMS spectra acquired prior to experimental treatment revealed significant differences between the investigated eumelanins. However, systematic spectral changes upon maturation reduced these dissimilarities, indicating that intense heat and pressure treatment leads to the formation of a common, partially degraded, eumelanin molecular structure. Our findings elucidate the complementary nature of AHPO and ToF-SIMS during chemical characterization of eumelanin traces in fossilized organismal remains.

4A combined XPS/ToF-SIMS approach for the 3D compositional characterization of Zr-based conversion of galvanized steel

2021 ◽  
pp. 150166
Author(s):  
Vanina Cristaudo ◽  
Kitty Baert ◽  
Priya Laha ◽  
Mary Lyn Lim ◽  
Elizabeth Brown-Tseng ◽  
...  
Keyword(s):  
Galvanized Steel ◽  
Tof Sims ◽  
Compositional Characterization

Characterization of a new type of molybdenum cofactor-mutant in cell cultures of Nicotiana tabacum

1984 ◽  
Vol 195 (1-2) ◽  
pp. 186-189 ◽  
Author(s):  
Ralf R. Mendel ◽  
Roger J. Buchanan ◽  
John L. Wray
Keyword(s):  
Nicotiana Tabacum ◽  
Cell Cultures ◽  
Molybdenum Cofactor ◽  
New Type

Virulence and Genetic Characterization of Six Baculovirus Strains Isolated From Different Populations of Spodoptera Frugiperda (Lepidoptera: Noctuidae)

2021 ◽  
Author(s):  
Ingrid Zanella-Saenz ◽  
Elisabeth A. Herniou ◽  
Jorge E. Ibarra ◽  
Ma.Cristina Del Rincón-Castro ◽  
Ilse Alejandra Huerta-Arredondo
Keyword(s):  
Biological Control ◽  
Cell Cultures ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
The United States ◽  
Infection Mechanisms ◽  
Different Populations

Abstract Fall armyworm (FAW), Spodoptera frugiperda (Smith, 1797), is a polyphagous, voracious, and economically important agricultural pest. Biological control of FAW is a strategy that must be further explored. This study evaluated six baculovirus strains isolated from infected FAW larvae from Mexico, Argentina, Honduras, and the United States. Five alphabaculoviruses (SfNPV-An2, SfNPV-Arg, SfNPV-Fx, SfNPV-Ho and SfNPV-Sin) and one betabaculovirus (SfGV-RV), were tested against FAW larvae, showing a wide diversity of virulence levels among strains when their estimated LC50s were compared, being SfNPVArg, SfNPV-Ho and SfNPV-Fx more virulent than SfNPV-An 2 , SfNPV-Sin and SfGV-RV. To determine any virulence difference in vitro studies of these isolates, Sf9 cell cultures were used. Interestingly, only ODVs from four of the test SfNPV strains showed infectivity on Sf9 cell cultures, and some differences in virulence were observed. Genomic restriction analyses and partial sequences of lef-8, lef-9 , and polh/granulin genes showed little variability among alphabaculoviruses, both, among them and with previously reported sequences. However, sequences from SfGV-RV were closer to previously reported sequences from the SfGVVG008 strain than the SfGV-Arg and SfGV-VG014 strains. The great difference in the in vivo virulence was not correlated with great similarity among the isolates. The characterization of these six baculoviruses isolates offers the basis for exploring their potential as biological control agents against S. frugiperda, as well the initial studies on their specific infection mechanisms, evolution, and ecology.

Characterization of a range of alkyl-bonded silica HPLC stationary phases: XPS and ToF-SIMS studies

1994 ◽  
Vol 21 (5) ◽  
pp. 263-273 ◽  
Author(s):  
V. A. Brown ◽  
D. A. Barrett ◽  
P. N. Shaw ◽  
M. C. Davies ◽  
H. J. Ritchie ◽  
...  
Keyword(s):  
Stationary Phases ◽  
Tof Sims
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