Antibiotic resistance peculiarities of S. aureus isolates, obtained from nasal and throat mucosa of outpatients, Chernivtsi city

The purpose of this study was to determine the specificity of sensitivity to antibiotics of S. aureus strains isolated from nasal mucous membranes and tonsils, as well as to identify the factors of antibiotic resistance. Materials and methods. The pure culture method was used to study smears of the palatine tonsils, the nose and the secret of the external auditory canal of 561, 56 and 15 cultures, respectively. Identification of isolated cultures was carried out according to morphological, tinctorial, physiological and biochemical characteristics. The sensitivity of S. aureus strains to antibiotics was studied and analyzed, 211 of which were isolated from the mucous of the palatine tonsils and 18 - from the nasal mucous. All the isolated strains of S. aureus were determined for the presence of antibiotic resistance factors (FA) -ß-lactamases (BL) and penicillin-binding protein (PВPs). Results. High percentage of strains resistant to ß-lactam antibiotics and macrolides was found in both groups of studied cultures. However, the number of resistant forms to these antibiotics was higher among nasal strains. At the same time, none of the resistant strain to aminoglycosides, fluoroquinolones, lincosamides, tetracyclines, and vancomycin was detected among them. 9.57 % of the strains isolated from the tonsillar mucosa were resistant to the last one. BL and PВPs antibiotic resistance factors of isolated S. aureus strains were more frequent among nasal isolates (BL – 83.3 %, PВPs – 66.7 %) than in strains isolated from the palatine tonsils (BL – 66.3 %, PВPs – 38.6 %), P < 0.05. Sensitivity to antibiotics of S. aureus strains having both FA simultaneously (30 strains) and strains having none of them (26 strains) turned out to be different. Among the strains having both FA, 100 % were resistant to penicillin, 93.3 % to oxacillin, and 36.7 % to vancomycin. Whereas there were 3.9 %, 0.0 %, and 7.7 % strains without FA resistant to these antibiotics, respectively. Resistance to azithromycin was greater in the group of strains with FA: 26.7 % versus 7.7 % in the group without FA. The strains of both groups were highly sensitive with an insignificant difference to other studied antibiotics (aminoglycosides, fluoroquinolones, macrolides, lincosamides and tetracyclines). Conclusions. S. aureus strains isolated from the mucous membranes of the nose and tonsils differ in sensitivity to antibiotics and the presence of FA. The nasal strains of S. aureus are more likely to be resistant to ß-lactam antibiotics and macrolides. Vancomycin resistant strains of S. aureus are significantly more common among strains with FA

Quantum-critical spin dynamics in quasi-one-dimensional antiferromagnets

By means of nuclear spin-lattice relaxation rate 1/T1, we follow the spin dynamics as a function of the applied magnetic field in two gapped one-dimensional quantum antiferromagnets: the anisotropic spin-chain system NiCl2-4SC(NH2)2 and the spin-ladder system (C5H12N)2CuBr4. In both systems, spin excitations are confirmed to evolve from magnons in the gapped state to spinons in the gapples Tomonaga-Luttinger-liquid state. In between, 1/T1 exhibits a pronounced, continuous variation, which is shown to scale in accordance with quantum criticality. We extract the critical exponent for 1/T1, compare it to the theory, and show that this behavior is identical in both studied systems, thus demonstrating the universality of quantum critical behavior

In Brain Multi-Photon Imaging of Vaterite Drug Delivery Cargoes loaded with Carbon Dots

Biocompatible fluorescent agents, such as phenylenediamine carbon dots (CDs), are key contributors to the theragnostic paradigm, enabling real-time in vivo imaging of drug delivery cargoes. This study explores the optical properties of these CDs, demonstrating their potential for two-photon fluorescence imaging in brain vessels. Using an open aperture z-scan technique, we measured the wavelength-dependent nonlinear absorption cross-section of the CDs, achieving a peak value near 50 GM. This suggests the potential use of phenylenediamine CDs for efficient multiphoton excitation in the 775 - 895 nm spectral range. Mesoporous vaterite nanoparticles were loaded with fluorescent CDs to examine the possibility of a simultaneous imaging and drug delivery platform. Efficient one and two-photon imaging of the CD-vaterite composites, uptaken by macrophage and genetically engineered C6-Glioma cells, was demonstrated. For an in vivo scenario, vaterite nanoparticles loaded with CDs were directly injected into the brain of a living mouse, and their flow was monitored in real-time within the blood vessels. The facile synthesis of phenylenediamine carbon dots, their significant nonlinear responses, and biological compatibility show a viable route for implementing drug tracking and sensing platforms in living systems

Quantifying loopy network architectures

Biology presents many examples of planar distribution and structural networks having dense sets of closed loops. An archetype of this form of network organization is the vasculature of dicotyledonous leaves, which showcases a hierarchically-nested architecture containing closed loops at many different levels. Although a number of methods have been proposed to measure aspects of the structure of such networks, a robust metric to quantify their hierarchical organization is still lacking. We present an algorithmic framework, the hierarchical loop decomposition, that allows mapping loopy networks to binary trees, preserving in the connectivity of the trees the architecture of the original graph. We apply this framework to investigate computer generated graphs, such as artificial models and optimal distribution networks, as well as natural graphs extracted from digitized images of dicotyledonous leaves and vasculature of rat cerebral neocortex. We calculate various metrics based on the Asymmetry, the cumulative size distribution and the Strahler bifurcation ratios of the corresponding trees and discuss the relationship of these quantities to the architectural organization of the original graphs. This algorithmic framework decouples the geometric information (exact location of edges and nodes) from the metric topology (connectivity and edge weight) and it ultimately allows us to perform a quantitative statistical comparison between predictions of theoretical models and naturally occurring loopy graphs.Comment: 17 pages, 8 figures. During preparation of this manuscript the authors became aware of the work of Mileyko at al., concurrently submitted for publicatio

Why are Prices Sticky? Evidence from Business Survey Data

This paper offers new insights on the price setting behaviour of German retail firms using a novel dataset that consists of a large panel of monthly business surveys from 1991-2006. The firm-level data allows matching changes in firms' prices to several other firm-characteristics. Moreover, information on price expectations allow analyzing the determinants of price updating. Using univariate and bivariate ordered probit specifications, empirical menu cost models are estimated relating the probability of price adjustment and price updating, respectively, to both time- and state- dependent variables. First, results suggest an important role for state-dependence; changes in the macroeconomic and institutional environment as well as firm-specific factors are significantly related to the timing of price adjustment. These findings imply that price setting models should endogenize the timing of price adjustment in order to generate realistic predictions concerning the transmission of monetary policy. Second, an analysis of price expectations yields similar results providing evidence in favour of state-dependent sticky plan models. Third, intermediate input cost changes are among the most important determinants of price adjustment suggesting that pricing models should explicitly incorporate price setting at different production stages. However, the results show that adjustment to input cost changes takes time indicating "additional stickiness" at the last stage of processing

Changes in catastrophic health expenditure in post-conflict Sierra Leone: an Oaxaca-blinder decomposition analysis.

BACKGROUND: At the end of the eleven-year conflict in Sierra Leone, a wide range of policies were implemented to address both demand- and supply-side constraints within the healthcare system, which had collapsed during the conflict. This study examines the extent to which households' exposure to financial risks associated with seeking healthcare evolved in post-conflict Sierra Leone. METHOD: This study uses the 2003 and 2011 cross-sections of the Sierra Leone Integrated Household Survey to examine changes in catastrophic health expenditure between 2003 and 2011. An Oaxaca-Blinder decomposition approach is used to quantify the extent to which changes in catastrophic health expenditure are attributable to changes in the distribution of determinants (distributional effect) and to changes in the impact of these determinants on the probability of incurring catastrophic health expenditure (coefficient effect). RESULTS: The incidence of catastrophic health expenditure decreased significantly by 18% from approximately 50% in 2003 t0 32% in 2011. The decomposition analysis shows that this decrease represents net effects attributable to the distributional and coefficient effects of three determinants of catastrophic health expenditure - ill-health, the region in which households reside and the type of health facility used. A decrease in the incidence of ill-health and changes in the regional location of households contributed to a decrease in catastrophic health expenditure. The distributional effect of health facility types observed as an increase in the use of public health facilities, and a decrease in the use of services in facilities owned by non-governmental organizations (NGOs) also contributed to a decrease in the incidence of catastrophic health expenditure. However, the coefficient effect of public health facilities and NGO-owned facilities suggests that substantial exposure to financial risk remained for households utilizing both types of health facilities in 2011. CONCLUSION: The findings support the need to continue expanding current demand-side policies in Sierra Leone to reduce the financial risk of exposure to ill health

Evidence of a dynamic association between intergroup contact and intercultural competence

Three studies explored the association between intergroup contact and intercultural competence. Study 1 and Study 2 provided evidence of a cross-sectional association between intergroup contact and intercultural competence in which positive contact was associated with increased intercultural competence and negative contact was associated with reductions in this outcome. In Study 3 longitudinal data allowed us to test the possibility of mutual influence between these variables whereby intercultural competence is not only a consequence of intergroup contact, but is also predictive of the quality of future intergroup contact. Results showed that positive contact was longitudinally associated with improvements in intercultural competence, and that higher intercultural competence was associated with a reduction in future negative contact. Findings speak to the importance of taking a dynamic outlook on contact effects. The beneficial consequences of positive contact may be the same variables capable of transforming future contact encounters and reducing the likelihood of negative interactions