Concentration Index Values Research Articles

Sağlık Hizmetleri Kullanımında Hakkaniyet: Türkiye Sağlık Sisteminin Değerlendirilmesi: Kesitsel Araştırma

Objective: This study aims to analyse and evaluate the equity level of healthcare utilization by years in Türkiye by exploring the relationship between health services utilization and the factors that are predisposing, enabling and need factors in 'Behavioural Model' developed by Andersen. Material and Methods: The concentration index and regression analyses were used to estimate equity levels and to explore the effects of predisposing, enabling and need factors. Data of 5 Türkiye Health Surveys conducted in years of 2008, 2010, 2012, 2014 and 2016 was used to reach this study's purposes. Equity in healthcare utilization was investigated for four healthcare utilization indicators: 1) Services provided by family/practitioner physicians, 2) Services provided by specialized physicians, 3) Day care/outpatient care services, and 4) Inpatient care services provided by hospitals. Results: Estimated concentration index values for income level, education level, and number of diseases showed that health services utilization was concentrated among people having less income and education level as well as more diseases. Regression analyses also indicated that the variables of income and education level, and disease existence and number of diseases as well as some other socio-demographic characteristics of individuals had significant effects on health services utilization. Conclusion: Considering the effects of predisposing, enabling and need factors on the utilization of health services in Türkiye by years, it might be concluded that equity level in Turkish Healthcare System has been improved.

An Analysis of Concentration and Competition in the Banking Sector of the Republic of Serbia

Abstract The degree of the banking sector concentration is a structural variable and refers to the number of banks in the system and the degree of their market power. The importance of measuring concentration in the banking sector stems from the causal relationship between the market structure and the competitive behaviour of market participants. Traditional models measuring the banking sector competition proceed from the market structure and concentration measures. In contrast, modern approaches to measuring competition rely on non-structural models and analysis of the behaviour of market participants. The paper analyzes the degree of concentration and competition in the banking sector of the Republic of Serbia. The traditional and most frequently used indices, the concentration ratio and the Herfindahl-Hirschman index, are used to measure concentration. The values of these indices show low banking sector concentration but a rise in the observed period. The values of the comprehensive industrial concentration index and the entropy coefficient confirm the concentration absence in the banking sector of the Republic of Serbia. In addition to the usual banking sector concentration measures, the authors use the Linda index to assess the banking sector concentration and competitiveness, to show the absence of an oligopolistic structure in terms of total balance sheet assets, lending and deposit activity of banks.

Anticancer activities of a metal-free phthalocyanine on MCF-7 and MDA-MB-231 cells and singlet oxygen production as a photosensitizer in PDT

Cancer, which is often described as an uncontrollable rapid proliferation of cells, is currently the leading cause of death in the world together with cardiac disease. Therefore, the main purpose of the current research work was to study the anticancer effects of a first-time-synthesized phthalocyanine (Pc) as photosensitizer in PDT against cancer and evaluate its effects on human cells in vitro. Quantum yields of singlet oxygen photogeneration were in air using the relative method with standard-ZnPc as reference and DPBF as chemical quencher for singlet oxygen. The concentration of DPBF was prepared almost 3 x 10-5 molar to avoid chain reactions induced by DPBF in the presence of singlet oxygen. Solutions of Pc as sensitizer (absorbance = 2.0 at the irradiation wavelength) containing DPBF were prepared in the dark and irradiated in the Q band region using the setup described. DPBF degradation at 417 nm was monitored with UV-Vis spectrophotometry. For in vitro studies, nine different MFPc-1 concentrations (0.2 µM- 0.4 µM- 0.8 µM- 1.6 µM- 3.2 µM- 6.4 µM- 12.8 µM- 25.6 µM- 51.2 µM) applied to MCF-7 and MDA-MB-231 breast cancer cell lines for 24 hours and MTT assay was carried out. After determination of optimum concentration, mitotic index, and apoptotic index values of cell lines were determined with administration of these concentrations. Singlet oxygen quantum yield (Φ), which is a measure of the efficiency, of MFPc-1 was found 0.50, although MFPc-1 is being metal-free phthalocyanine. For in vitro studies after the application of different concentrations to MCF-7 and MDA-MB-231 for 24 hours, the optimum concentration was determined as 12 µM for both cell lines by the MTT assay. After application of the determined optimum concentration for 24, 48 and 72 hours, there was a significant decrease in the mitotic index values and significant increase in the apoptotic index values of both MCF-7 and MDA-MB-231 breast cancer cell lines.

H2dpa derivatives containing pentadentate ligands: An acyclic adjuvant potentiates meropenem activity invitro and invivo against metallo-β-lactamase-producing Enterobacterales.

The emergence and dissemination of metallo-β-lactamases (MBLs) producing Enterobacterales is a great concern for public health due to the limited therapeutic options. No MBL inhibitors are currently available in clinical practice. Herein, we synthesized a series of H2dpa derivatives containing pentadentate-chelating ligands and evaluated their inhibitory activity against MBLs. Related compounds inhibited clinically relevant MBLs (Imipenemase, New Delhi metallo-β-lactamase (NDM) and Verona integron-encoded metallo-β-lactamase) with IC50 values of 1-4.9μM. Invitro, the most promising compounds, 5b and 5c, which had a chiral methyl at the acid adjacent to 5a, demonstrated potent synergistic activity against engineered strains, with fractional inhibitory concentration index values as low as 0.07-0.18. The addition of 5b and 5c restored meropenem efficacy against 42 MBL-producing Enterobacterales and Pseudomonas aeruginosa to satisfactory clinical levels. In addition, safety tests revealed that 5b/5c showed no toxicity in red blood cells, cell lines or mouse model. Further studies demonstrated that compounds 5b and 5c were non-competitive MBL inhibitors. Invivo compounds 5b and 5c potentiated meropenem efficacy and increased the survival rate from 0 to at least 83% in mice with sepsis caused by an NDM-1-positive clinical strain. The activity of the compounds exhibited consistency at the molecular, cellular, and invivo levels. These data indicated that H2dpa derivatives 5b and 5c containing pentadentate-chelating ligands may be worthy of further study.

Reanalysis of the daily precipitation concentration index in the Río Grande of Morelia basin

The daily precipitation concentration index is a useful tool for the analysis of the statistical structure of rainfall. However, it is necessary to be careful with the data used for its calculation since this index can be sensitive to both the temporal location of the data and the length of the records. Thus, the objective of this work consisted of a re-analysis of the daily precipitation concentration index (CI) in the Río Grande de Morelia basin to determine how the temporal location of the data and the length of the records affect the CI values. In addition to analyzing the behavior of the CI under three different conditions. The results show that the temporary location of the records can affect the value of the CI, increasing it if the last available years are analyzed or decreasing it if records before 1980 are taken. Regarding the length of the records, it was found that the value of this index tends to stabilize in most of the cases studied for record lengths greater than 20 years. The behavior of the CI at the annual level is within that reported in the literature, and at the decade level and for the 30-year, a decrease in its variability was observed. Therefore, it is recommended that in studies of this type, a common recording period be chosen for the analyzes and a length according to the objectives pursued.

Comparing checkerboard, isobologram and CCD methods for drug combination: A case study of ciprofloxacin and plant extracts on Escherichia coli and Shigella

To investigate the interactive antimicrobial activity of conventional antibiotics, namely ciprofloxacin and Mangifera indica bark ethanol extract, Psidium guajava leaves essential oil against two Gram-negative bacteria using checkerboard, isobologram, and central composite design (CCD) methods. The checkerboard method was used for the determination of the fractional inhibitory concentration index (FICI) value needed for the interpretation of the interaction. The isobologram was constructed and the geometrical disposition of the combinations used to define the type of interaction. The CCD experimental plan was used to obtain the bactericidal probability. In general the results indicated that the methods do have few similarities in their output for the same combination. According to the results, the isobologram method can be considered as more adapted and can be confirmed using the CCD method for antimicrobials combination because of the flexibility in the testing ratio of antimicrobials to be used. This study brings into light the fact that isobologram and CCD methods should be compared when studying drug interaction. Key words: Antibiotics, central composite design, checkerboard, isobologram, plant extracts, Escherichia coli, Shigella species.

Inequality in dental care expenditure in Iranian households: analysis of income quintiles and educational levels

BackgroundOral health is a major public health issue which affects the human life. Access to dental care is one of the important factors in maintaining oral health. This study was aimed to investigate inequality in dental care expenditure in Iranian households.MethodsThe present study is a secondary analysis of a national cross-sectional survey. The data collected from the Households Income and Expenditure Survey in 2016 and 2017. The final sample consisted of 54,354 households living in rural and urban regions of all the provinces. Inequalities in household’s dental care expenditure per capita in respect to income quintiles and educational level were measured based on the Gini coefficient and concentration index.ResultsThe results showed that about 8% of households had paid for dental care during the month before sampling. The Gini coefficient value was estimated to be 0.97 and 0.96 for dental care expenditure per capita respectively in absolute and relative measure. It indicated a significant inequality in the dental expenditure among the sample households. The values of concentration index were positive and significant for all dental care subcategories in respect to the provincial and national income quintiles as well as the educational level of the head of the household.ConclusionsIncome and educational inequality in the both absolute and relative dental services expenditure of the Iranian households were in favor of higher income groups as well as higher educational level of household heads. Income inequality was higher in total dental care expenditure per capita and all its subcategories than the educational inequalities of dental expenditure. In order to reduce these inequalities, the policymakers need to pay special attention to low-income households, particularly those with low-educated heads.

In vitro and in vivo analysis of monotherapy and dual therapy with ethyl caffeate and fluconazole on virulence factors of Candida albicans and systemic candidiasis

Candida albicans is the most clinically prevalent cause of systemic fungal infections in the immunocompromised population. The biofilm-forming ability of C. albicans confers resistance to conventional antifungal agents. The main aim of this study was to investigate the antifungal effects of ethyl caffeate (EC) alone and in combination with fluconazole (FLU) against C. albicans isolates. The single and combined antifungal activities of EC and FLU were evaluated against planktonic and biofilm cells of C. albicans by the checkerboard assay, time-kill test, crystal violet assay, live/dead staining, rhodamine 6G (R6G) efflux analysis and hydrolase activity. Monotherapy and dual therapy of EC and FLU against systemic candidiasis in a mouse model was also evaluated. The results showed that EC+FLU displayed synergism in 14/26 planktonic C. albicans isolates and 11/26 C. albicans biofilms with fractional inhibitory concentration index (FICI) values ranging between 0.06-0.49 and 0.02-0.38, respectively. Compared with monotherapy, the combination of EC+FLU can markedly inhibit adhesion, yeast-to-hyphae transition, premature and mature biofilm metabolism, hydrolase secretion and drug efflux function of C. albicans Z1407 and Z4935. Moreover, EC can potentiate the antifungal activity of FLU to improve mouse survival, reduce fungal burden and alleviate pathological damage in both C. albicans isolates compared with EC or FLU used alone. EC exhibits a moderate antifungal potential but can be a strong synergist with FLU against C. albicans, highlighting the potential of EC in clinical antifungal therapy as a sensitiser.

Radon potential mapping in Jangsu-gun, South Korea using probabilistic and deep learning algorithms

The adverse health effects associated with the inhalation and ingestion of naturally occurring radon gas produced during the uranium decay chain mean that there is a need to identify high-risk areas. This study detected radon-prone areas using a geographic information system (GIS)-based probabilistic and machine learning methods, including the frequency ratio (FR) model and a convolutional neural network (CNN). Ten influencing factors, namely elevation, slope, the topographic wetness index (TWI), valley depth, fault density, lithology, and the average soil copper (Cu), calcium oxide (Cao), ferric oxide (Fe2O3), and lead (Pb) concentrations, were analyzed. In total, 27 rock samples with high activity concentration index values were divided randomly into training and validation datasets (70:30 ratio) to train the models. Areas were categorized as very high, high, moderate, low, and very low radon areas. According to the models, approximately 40% of the study area was classified as very high or high risk. Finally, the radon potential maps were validated using the area under the receiver operating characteristic curve (AUC) analysis. This showed that the CNN algorithm was superior to the FR method; for the former, AUC values of 0.844 and 0.840 were obtained using the training and validation datasets, respectively. However, both algorithms had high predictive power. Slope, lithology, and TWI were the best predictors of radon-affected areas. These results provide new information regarding the spatial distribution of radon, and could inform the development of new residential areas. Radon screening is important to reduce public exposure to high levels of naturally occurring radiation.

Daily precipitation concentration in Central Coast Vietnam

Empirical frequency distribution of daily precipitation amounts can be fitted by a negative exponential distribution, because anywhere there are many small daily totals and few large ones. Therefore, the cumulative percentages of days with precipitation, sorted in increasing order according to their amounts, against the cumulative percentage of the rainfall amounts that they contribute are fitted by positive exponential curves Y = aXebx, a and b constants. Based on these curves, the Concentration Index (CI) evaluates the contribution of the rainiest days to the total amount. In this study the CI has been calculated for 15 meteorological stations in Da Nang city and Quang Nam province in Central Coast Vietnam, for the 1979–2016 period. The results show high values of CI, ranging from 0.62 to 0.72. Conversely, the linear correlation between altitude and CI is negative (R = -0.60, p < 0.01). There are no correlations between the latitude nor the annual mean number of precipitation days and the CI. CI change for the sub-periods of 1979–1997 and 1998–2016 is also analyzed.

Design, Synthesis, and Antibacterial Evaluation of Novel Ocotillol Derivatives and Their Synergistic Effects with Conventional Antibiotics

The improper use of antibiotics has led to the development of bacterial resistance, resulting in fewer antibiotics for many bacterial infections. Especially, the drug resistance of hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) is distinctly serious. This research designed and synthesized two series of 3-substituted ocotillol derivatives in order to improve their anti-HA-MRSA potency and synergistic antibacterial activity. Among the synthesized compounds, 20–31 showed minimum inhibitory concentration (MIC) values of 1–64 µg/mL in vitro against HA-MRSA 18–19, 18–20, and S. aureus ATCC29213. Compound 21 showed the best antibacterial activity, with an MIC of 1 μg/mL and had synergistic inhibitory effects. The fractional inhibitory concentration index (FICI) value was 0.375, when combined with chloramphenicol (CHL) or kanamycin (KAN). The structure–activity relationships (SARs) of ocotillol-type derivatives were also summarized. Compound 21 has the potential to be developed as a novel antibacterial agent or potentiator against HA-MRSA.

New Insight into the Chemical Composition, Antimicrobial and Synergistic Effects of the Moroccan Endemic Thymus atlanticus (Ball) Roussine Essential Oil in Combination with Conventional Antibiotics.

This study reported the volatile profile, the antimicrobial activity and the synergistic potential of essential oil (EO) from the Moroccan endemic Thymus atlanticus (Ball) Roussine, in combination with the antibiotics ciprofloxacin and fluconazole for the first time, to the best of our knowledge. The EO chemical composition was determined by gas chromatography coupled to mass spectrometry (GC-MS) analysis and the antimicrobial activity assessed by the disc diffusion method against three Gram positive (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus) and three Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli and one clinical isolate, Klebsiella pneumonia). The antifungal activity was evaluated in four pathogenic yeasts (Candida albicans, C. glabrata, C. krusei and C. parapsilosis). The minimum inhibition concentration (MIC) and the synergistic effect with ciprofloxacin and fluconazole were determined by the two-fold dilution technique and checkerboard test, respectively. Twenty-one constituents were identified by GC-MS in the EO, including carvacrol (21.62%) and borneol (21.13%) as the major components. The EO exhibited a significant antimicrobial activity with inhibition zones ranging from 0.7 mm to 22 mm for P. aeruginosa and B. subtilis, respectively, and MIC values varying from 0.56 mg/mL to 4.47 mg/mL. The fractional inhibitory concentration index (FICI) values ranged from 0.25 to 0.50 for bacteria and from 0.25 to 0.28 for yeasts. The maximum synergistic effect was observed for K. pneumonia with a 256-fold gain of antibiotic MIC. Our results have suggested that EO from T. atlanticus may be used alone or in association with antibiotics as a new potential alternative to prevent and control the emergence of resistant microbial strains both in the medical field and in the food industry.

Impact of climate change on rainfall variability in the Blue Nile basin

Monthly rainfall data for Blue Nile Basin (BNB) were obtained from the Ethiopian Meteorological Authority (1950–2018). Long-term trends in the BNB annual and monthly rainfall are investigated in this study. The challenges of the paper were to explore the impact of climate change on the study area using sound practical methods. The paper used the widely used statistical methods to find precisely the significance of the impact of climate change rainfall variability and distribution both spatially and temporally in the BNB. The statistical significance of the trend in the study is calculated by the Mann-Kendall (MK) test. Data were analyzed using the coefficient of variation, anomaly index, and precipitation concentration index. The coefficient of variation is high in Kiremt rainfall which implies more inter-annual variability of Bega rainfall than Kiremt (Coefficient of Variation (CV): Bega˃ Belg˃ Kiremt season). Based on Precipitation Concentration Index (PCI) value, the number of moderate concentration years (89.9%) has been increasing through time and the study area has encountered successive years of drought. The results showed that the annual, Bega, Belg, and Kiremt precipitation over the whole of BNB is significantly decreasing except Bega season with a magnitude of 36.38, 3.8, 7.8, and 24.7 mm per decade respectively. The rainfall in the study area is characterized by a high CV. Moreover, prolonged droughts have become common which adversely affects the agricultural system. It was also found that very low values of rainfall anomalies that correspond to severe droughts were associated with El Niño Southern Oscillation (ENSO) events.

In vitro antimicrobial and synergistic effect of essential oil from the red macroalgae Centroceras clavulatum (C. Agardh) Montagne with conventional antibiotics

Objective: To study the chemical profile, antimicrobial properties, and synergistic effect with known antibiotics of essential oil extracted from the marine red macroalgae Centroceras clavulatum (C. Agardh) Montagne, collected in Morocco. Methods: The chemical composition of the oil was analyzed by gas chromatography-mass spectrometry. The oil was evaluated for antibacterial (Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, and Klebsiella pneumoniae), and antifungal activity (Candida albicans, Candida glabrata, Candida krusei, and Candida parapsilosis), by the disc diffusion method. The minimum inhibitory and minimum microbicidal concentrations of the oil were determined, as well as the synergistic effects of its application combined with the antibiotics ciprofloxacin and fluconazole, by the checkerboard method. Results: Thirty molecules were identified in the essential oil, comprising 96.27% of the total oil composition. Monoterpenes such as carvacrol (36.06%) were the most abundant compounds, followed by caryophyllene (14.67%), endo-borneol (9.04%), pyroterebic acid (3.23%) and caryophyllene oxide (3.13%). The oil exhibited a moderate antimicrobial activity with inhibition zone diameters ranging from 9.0 to 15.0 mm. The minimum inhibitory concentration values varied between 0.9 and 14.7 mg/mL, and Bacillus subtilis and Escherichia coli were the more sensitive bacteria with 0.9 and 1.9 mg/mL, respectively. The minimum microbicidal concentration values ranged from 0.4 to 14.7 mg/mL. A significant synergic action was observed when the oil was applied in combination with ciprofloxacin and fluconazole, with fractional inhibitory concentration index values ranging from 0.31 to 0.50. Synergy was found in 80% of the combinations and a 2 to 16-fold reduction of antibiotics MIC was observed. Conclusions: Our findings suggest that the essential oil of Centroceras clavulatum should be further appraised for its potential use in the management of multi-drug resistant microorganisms, with the purpose to restore the activity of standard antimicrobial drugs.

Design, synthesis and antibacterial activity of chalcones against MSSA and MRSA planktonic cells and biofilms

Staphylococcus aureus is the one of the most successful modern pathogens. The same bacterium that lives as a skin and mucosal commensal can be transmitted in health-care and community-settings and causes severe infections. Thus, there is a great challenge for a discovery of novel anti-Staphylococcus aureus compounds, which should act against resistant strains. Herein, we designed and synthesized a series of 17 chalcones, substituted by amino group on ring A, which were evaluated against methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus MRSA planktonic cells. The antibacterial potency was improved by substituents on ring B, which were designed according to Topliss’ manual method. 4-bromo-3′-aminochalcone (5f) was the most active, demonstrating minimum inhibitory concentration (MIC) values of 1.9 μg mL−1 and 7.8 µg mL−1 against MSSA and MRSA, respectively. The association of 5f with vancomycin demonstrated synergistic effect against MSSA and MRSA, with Fractional Inhibitory Concentration Index (FICI) values of 0.4 and 0.3, respectively. Subinhibitory concentration of 5f inhibited the MSSA and MRSA adhesion to human keratinocytes. Chalcone 5f was able to reduce MSSA and MRSA biofilm formation, as well as acts on preformed biofilm in concentration-dependent mode. Scanning electron microscopy analyses confirmed severe perturbations caused by 5f on MSSA and MRSA biofilm architecture. The acute toxicity assay, using Galleria mellonella larvae, indicated a low toxic effect of 5f after 72 h, displaying lethality of 20% and 30% at 7.8 μg mL−1 and 78.0 μg mL−1, respectively. In addition, the antibacterial activity spectrum of 5f indicated action against planktonic cells of Enterococcus faecalis (MIC = 7.8 μg mL−1), Acinetobacter baumannii (MIC = 15.6 μg mL−1) and Mycobacterium tuberculosis (MIC = 5.7 μg mL−1). Altogether, these results open new avenues for 5f as an anti-Staphylococcus aureus agent, with potential applications as antibacterial drug, adjunct of antibiotics and medical devices coating.

Differences in the Content of Zn Fractions in the Profiles of Soils from Allotment and Domestic Gardens in South-Eastern Poland

The aim of the research was to show the distribution of fractions as well as bioavailability and the total forms of Zn in the profiles of soils from domestic gardens and family allotment gardens in six cities in south-eastern Poland. Results found that the level of Zn total form varied in the ranges from A horizon: 12.75–154.75 mg·kg−1 in sandy soils and 18.20–104.00 mg·kg−1 in silty soils. Accumulation of metals was assessed using concentration indices, Igeo, and the Cav/Ct and BF indices of bioavailable forms. The analysis took into account the role of organic matter as an important component in binding the analyzed metals in soil horizons subjected to long-term horticultural cultivation. In the two groups of sandy and silty soils distinguished according to their particle size distribution, horticultural treatments were found to exert a greater impact on sandy soils. Additionally, higher contents of the examined element were stated in the humus horizons, as indicated by the high values of concentration and Igeo indices showing high Zn pollution in the soils. The content of bioavailable zinc forms was significantly high, especially in soils with a higher metal content.

PHYTOEXTRACTION OF CADMIUM AND LEAD FROM A CONTAMINATED SOIL USING EUCALYPTUS SEEDLINGS

This study aims to estimate critical concentrations of cadmium (Cd) and lead (Pb) in the soil which negatively affect growth of Eucalyptus camaldulensis Dehnh. seedlings, and to estimate some phytoextraction parameters for heavy metals (HM) from the soil to evaluate efficiency of seedlings in their potential use in phytotechnology to improve the environment with phytoremediation. Eucalyptus seedlings were treated with Cd concentrations 0, 25, 55, 85, and 110 mg kg-1 dry soil as CdCl2, and Pb concentrations 0, 125, 250, 450, and 550 mg kg-1 dry soil as PbCl2, and the experiment was designed using the completely randomized design (CRD) as a two-factor factorial experiments and the data were analyzed using SAS system. Results showed that the highest percentage decrease in dry weight of stems, leaves and roots were 55, 68.6, and 67.2%, respectively, at the interaction (110 Cd and 550 Pb) mg kg-1 dry soil compared with control, and Cd concentrations in stems, leaves and roots ranged between (0.375-372.167), (0.417-128.167) and (0.583-162.083) mg kg-1, respectively and Pb concentrations in stems, leaves and roots ranged between (9.583-62.375), (10.042-20.417) and (2.875-73.500) mg kg-1. It was found that values ​​of translocation factor (TF), biological accumulation coefficient (BAC), bioconcentration factor (BCF) and concentration index (CI) for Cd ranged between (0.611-4.239), (1.333-28.790), (0.383- 16.840) and (1-490.812) respectively, and values ​​of TF, BAC, BCF, and CI of Pb ranged between (0.275-5.702), (0.769-4.246), (0.295-7.539) and (1-3.833) respectively, and tolerance index (TI) values ​​ranged between (0.370-1). We concluded that Eucalyptus seedlings are suitable for phytoextraction applications within phytoremediation processes of soils contaminated with Cd and Pb.

Formation of the structure of commodity markets and barriers to entry to them in the conditions of digitalization of the economy: the advertising factor

The article is addressed to a wide range of readers, including research economists, as well as those who teach and study the theory of industrial markets in universities, and is devoted to the formation of the structure of commodity markets — both traditional and modern digital. The authors try to make progress in revealing the nature of the influence of the intensity of advertising activity in the industry on the values of concentration indicators, the size of entry barriers, and other structural parameters of industry markets.&#x0D; &#x0D; Based on the analysis of data on the Russian markets of mobile communication services and pharmaceuticals, the fundamental applicability of the concept of «U-shaped inverted curve» for characterizing the relationship between the level of advertising intensity in the industry and the values of concentration indices is established. On this basis, the hypothesis is formulated that the influence of the level of advertising intensity, including as an industry entry barrier, on the structure of markets is more significant in conditions of low and / or moderate concentration.&#x0D; &#x0D; The authors argue that the processes of digitalization of the economy today not only dynamically change the boundaries of modern industry markets and the nature of competition in them, but also strengthen the potential of advertising communications as a significant factor in the formation of the structure of digital markets.

Silver Nanoparticles Enhance Antimicrobial Efficacy of Antibiotics and Restore That Efficacy against the Melioidosis Pathogen

Melioidosis is an infectious disease caused by Gram-negative bacillus bacteria Burkholderia pseudomallei. Due to the emerging resistance of B. pseudomallei to antibiotics including ceftazidime (CAZ), the development of novel antibiotics and alternative modes of treatment has become an urgent issue. Here, we demonstrated an ability to synergistically increase the efficiency of antibiotics through their combination with silver nanoparticles (AgNPs). Combinations of four conventional antibiotics including CAZ, imipenem (IMI), meropenem (MER), and gentamicin sulfate (GENT) with starch-stabilized AgNPs were tested for their antibacterial effects against three isolates of B. pseudomallei. The combination of each antibiotic with AgNPs featured fractional inhibitory concentration (FIC) index values and fractional bactericidal concentration (FBC) index values ranging from 0.312 to 0.75 µg/mL and 0.252 to 0.625 µg/mL, respectively, against the three isolates of B. pseudomallei. The study clearly showed that most of the combinatorial treatments exhibited synergistic antimicrobial effects against all three isolates of B. pseudomallei. The highest enhancing effect was observed for GENT with AgNPs. These results confirmed the combination of each antibiotic with AgNPs restored their bactericidal potency in the bacterial strains that had previously been shown to be resistant to the antibiotics. In addition, morphological changes examined by SEM confirmed that the bacterial cells were severely damaged by combinations at the FBC level. Although bacteria produce fibers to protect themselves, ultimately the bacteria were killed by the antibiotic–AgNPs combinations. Overall, these results suggest the study of antibiotic–AgNPs combinations as an alternative design strategy for potential therapeutics to more effectively combat the melioidosis pathogen.

Transcriptomic Analysis of Drug-Resistance Acinetobacter baumannii under the Stress Condition Caused by Litsea cubeba L. Essential Oil via RNA Sequencing.

Litsea cubeba L. essential oil (LCEO) can affect the growth of drug-resistance bacteria. However, research on stress response of drug-resistant A. baumannii under sub-lethal LCEO concentrations had been limited so far. Therefore, transcriptomic analysis of A. baumannii under 1/2 minimum inhibitory concentration (MIC, 0.54 mg/mL) of LCEO was performed. Results of transcriptomic analysis showed that 320/352 genes were significantly up/down-regulated, respectively, in LCEO-treated A. baumannii. Both up and down-regulated genes were significantly enriched in three GO terms (oxidation-reduction process; oxidoreductase activity; oxidoreductase activity, acting on the CH-CH group of donors), which indicated that the redox state of A. baumannii was significantly affected by LCEO. LCEO may also inhibit aerobic respiration, synthesis of ketone bodies and the metabolism of some amino acids while, meanwhile, promoting fatty acid degradation of A. baumannii according to Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. The permeability and the stress of cell membrane of A. baumannii were significantly affected by LCEO. After crystal violet dyeing, the biofilm formation of A. baumannii was promoted/inhibited by extremely low/relatively high concentration of LCEO, respectively. LCEO and chloramphenicol have synergistic growth inhibitory effect against A. baumannii according to the Fractional Inhibitory Concentration Index (FICI) value = 0.375. Our results indicate that the growth of A. baumannii was inhibited by LCEO, and give insights into the stress response of A. baumannii under sub-lethal concentrations of LCEO. These results provided evidence that A. baumannii was inhibited by LCEO, and expanded knowledges of stress response of A. baumannii under sub-lethal concentration of LCEO.