SIMULTANEOUS ANALYSIS OF TWO-COMPONENT SYSTEMS BY DIFFUSE REFLECTANCE SPECTROSCOPY

1966 ◽  
Vol 44 (16) ◽  
pp. 1945-1950 ◽  
Author(s):  
R. W. Frei ◽  
D. E. Ryan ◽  
V. T. Lieu
Keyword(s):  
Diffuse Reflectance ◽  
Diffuse Reflection ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
Adsorbed State ◽  
Reflection And Transmission ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems ◽  
Layer Chromatography

Diffuse reflectance spectroscopy can be used for the analysis of multicomponent systems in the adsorbed state. The Kubelka–Munk theory for diffuse reflection and transmission on light-scattering layers has been applied for this analysis. Simple dye mixtures adsorbed on thin-layer chromatography-grade adsorbents were employed. The method can be adapted directly to the analysis of incompletely separated components on chromatographic adsorbents.

Reflectance spectroscopic determination of cobalt, nickel, and copper with pyridine-2-aldehyde-2-quinolylhydrazone

1968 ◽  
Vol 46 (2) ◽  
pp. 167-173 ◽  
Author(s):  
R. W. Frei ◽  
R. Liiva ◽  
D. E. Ryan
Keyword(s):  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
Good Reproducibility ◽  
Optimum Conditions ◽  
Cobalt Nickel ◽  
Nickel Cobalt ◽  
Cellulose Layers ◽  
Layer Chromatography

Nickel, cobalt, and copper are separated from interfering metals by thin-layer chromatography on silica gel and cellulose layers. The metals are sprayed with pyridine-2-aldehyde-2-quinolylhydrazone solution and determined by diffuse reflectance spectroscopy. Under optimum conditions, 0.01 µg per spot can be determined easily and with good reproducibility.

Diffusive layering during film growth in two-component systems with limited mutual solubility

2000 ◽  
Author(s):  
Grigory V. Merkulov ◽  
Valentin M. Ievlev ◽  
Evgeny V. Shvedov ◽  
Vadim P. Ampilogov
Keyword(s):  
Film Growth ◽  
Mutual Solubility ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems

scholarly journals Regulation of virulence and β-lactamase gene expression in Staphylococcus aureus isolates: cooperation of two-component systems in bloodstream superbugs

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sanaz Dehbashi ◽  
Hamed Tahmasebi ◽  
Behrouz Zeyni ◽  
Mohammad Reza Arabestani
Keyword(s):  
Staphylococcus Aureus ◽  
Real Time ◽  
Real Time Pcr ◽  
Quantitative Real Time Pcr ◽  
Gene Expressions ◽  
Resistance Development ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems ◽  
Lactamase Gene

Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA)-bloodstream infections (BSI) are predominantly seen in the hospital or healthcare-associated host. Nevertheless, the interactions of virulence factor (VFs) regulators and β-lactam resistance in MRSA-BSI are unclear. This study aims to characterize the molecular relationship of two-component systems of VFs and the expression of the β-lactamase gene in MRSA-BSI isolates. In this study, 639 samples were collected from BSI and identified by phenotypic methods. We performed extensive molecular characterization, including SCCmec type, agr type, VFs gene profiles determinations, and MLST on isolates. Also, a quantitative real-time PCR (q-RT PCR) assay was developed for identifying the gene expressions. Results Ninety-one (91) S. aureus and 61 MRSA (67.0%) strains were detected in BSI samples. The presence of VFs and SCCmec genes in MRSA isolates were as follows: tst (31.4%), etA (18.0%), etB (8.19%), lukS-PVL (31.4%), lukF-PV (18.0%), lukE-lukD (16.3%), edin (3.2%), hla (16.3%), hlb (18.0%), hld (14.7%), hlg (22.9%), SCCmecI (16.3%), SCCmecII (22.9%), SCCmecIII (36.0%), SCCmecIV (21.3%), and SCCmecV (16.3%). Quantitative real-time PCR showed overexpression of mecRI and mecI in the toxigenic isolates. Moreover, RNAIII and sarA genes were the highest expressions of MRSA strains. The multi-locus sequence typing data confirmed a high prevalence of CC5, CC8, and CC30. However, ST30, ST22, and ST5 were the most prevalent in the resistant and toxigenic strains. Conclusion We demonstrated that although regulation of β-lactamase gene expressions is a significant contributor to resistance development, two-component systems also influence antibiotic resistance development in MRSA-BSI isolates. This indicates that resistant strains might have pathogenic potential. We also confirmed that some MLST types are more successful colonizers with a potential for MRSA-BSI.

Monte Carlo Simulation of Electronic Excitation Migrationand Trappingin Disordered Two-Component Systems. A Comparison with Analytical Theories

1989 ◽  
Vol 44 (4) ◽  
pp. 257-261 ◽  
Author(s):  
Sławomir Błonski ◽  
Czesław Bojarski
Keyword(s):  
Monte Carlo ◽  
Electronic Excitation ◽  
Two Component System ◽  
Component System ◽  
Steady State Fluorescence ◽  
Donor And Acceptor ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems ◽  
Viscous Solution

Abstract Monte Carlo simulations of quantum yield and anisotropy of fluorescence in two-component systems have been conducted with various donor and acceptor concentrations and Förster radii ratios RDAO/RDDO. The influence of excitation migration and trapping on the fluorescence of the viscous solution has been considered. The results of the simulations have shown that steady-state fluorescence of a two-component system depends on the RDAO/RDDO ratio as predicted in LAF theory.

Sign in / Sign up

Export Citation Format

Share Document