61 research outputs found
Universal SSE algorithm for Heisenberg model and Bose Hubbard model with interaction
We propose universal SSE method for simulation of Heisenberg model with
arbitrary spin and Bose Hubbard model with interaction. We report on the first
calculations of soft-core bosons with interaction by the SSE method. Moreover
we develop a simple procedure for increase efficiency of the algorithm. From
calculation of integrated autocorrelation times we conclude that the method is
efficient for both models and essentially eliminates the critical slowing down
problem.Comment: 6 pages, 5 figure
Application of Raman spectroscopy to study the inactivation process of bacterial microorganisms
Raman spectroscopy (RS) is one of the promising approaches for structural and functional studies of various biological
objects, including bacterial microorganisms. Both traditional biochemical tests and genetic methods which require
expensive reagents, consumables and are time-consuming are used for bacterial analysis. Spectroscopic methods are
positioned as noninvasive, highly sensitive, and requiring minimal sample preparation. In this work we investigated
the possibility of using the RS method using optical sensors based on gold anisotropic nanoparticles. The applicability
of the method was demonstrated by studying the effect of a broad-spectrum cephalosporin antibiotic and an extract of
Viburnum opulus L (VO) on Escherichia coli (E. Coli) colonies. The studies were performed by Raman spectroscopy
using a Virsa spectrometer (Renishaw). Raman signal amplification was carried out using two original optical sensors
proposed by the authors. To create sensors, we used a chemical method of depositing gold nanostars on APTES-modified
quartz glasses and a physical method for creating sensors based on anodizing titanium surfaces. The results of the study
showed the high sensitivity and information content of the proposed method. The possibility of using the RS method
for studying the inactivation of bacterial microorganisms is shown. Spectral Raman bands of E. Coli were determined
and identified before and after exposure to VO extract and antibiotic as a control. A decrease in the intensity of spectral
modes corresponding to amino acids and purine metabolites was found in the average Raman spectrum of E. Coli
after exposure to VO extract. For the first time, a study of the antimicrobial effect of an aqueous extract of VO fruits
was carried out by the method of Raman scattering. It has been shown that the use of plant extracts, including VO fruit
extracts, to inactivate the vital activity of bacterial colonies is a promising approach to the search for new alternative
antibacterial agents. The results obtained are in good agreement with the already known scientific studies and confirm
the effectiveness of the proposed method
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