Correlation of ciprofloxacin resistance with the AdeABC efflux system in Acinetobacter baumannii clinical isolates

Background: Acinetobacter baumannii is one of the most important pathogens capable of colonization in burn patients, leading to drug-resistant wound infections. This study evaluated the distribution of the AdeABC efflux system genes and their relationship to ciprofloxacin resistance in A. baumannii isolates collected from burn patients. Methods: A total of 68 A. baumannii clinical strains were isolated from patients hospitalized in Motahari Burns Center in Tehran, Iran. Ciprofloxacin susceptibility was tested by the disk diffusion and agar dilution methods. PCR amplification of the adeRS-adeB drug efflux genes was performed for all resistant and susceptible isolates. To assess the role of the drug efflux pump in ciprofloxacin susceptibility, carbonyl cyanide 3-chlorophenylhydrazone (CCCP) was used as an efflux pump inhibitor (EPI). Results: Approximately 95.6% of the Acinetobacter isolates were resistant to ciprofloxacin, with minimum inhibitory concentration (MIC) values ranging from 4 to ≥128 μg/mL. The susceptibility of 86.1% of the resistant isolates increased by factors of 2 to 64 in the presence of CCCP. All resistant isolates were positive for the adeRS-adeB genes, and 73.2% of them had mutations in the AdeRS regulatory system. Conclusions: The results showed that AdeABC genes are common in A. baumannii, which might be associated with ciprofloxacin non-susceptibility, as indicated by the observed linkage to the presence of the genes essential for the activity of the AdeABC, several single mutations occurring in the adeRS regulatory system, and an increase of ciprofloxacin susceptibility in the presence of a CCCP EPI. © The Korean Society for Laboratory Medicin

Personlighetstrekk, matverdier og forbrukeratferd

The thesis consists of four papers investigating the effects of personality traits and food values on food-related choices and behavior. The analysis uses data from the Norwegian Monitor Survey (NMS) and an online survey (OS) conducted in Norway and the US. Both data sets include a twenty-item version of the Big Five personality traits: openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism. The OS include a bestworst choice experiment with twelve food values: naturalness, safety, environmental impact, origin, fairness, nutrition, taste, appearance, convenience, price, animal welfare, and novelty. In the NMS, a simplified version of the method is used. The overall findings of the thesis can be summarized in four points: (1) Personality traits influence the preference structure for food values. Openness to experience and agreeableness are associated with more altruistic preferences. (2) The effects of personality traits on attitudes towards GM food are neither large nor consistent across products and samples. Food values are more important in determining the attitudes towards GM food. A large part of the resistance towards GM food seems to be based on perceptions that these products are less natural, less fair to stakeholders in the supply chain, more harmful to the environment, and bad for the welfare of animals. (3) Respondents’ food consumption patterns reflect their differences in personalities and food values. More open and agreeable respondents adopt the dietary patterns that they perceive to have lower environmental impacts, fairer towards farmers, processors, and retailers, and protect local production. (4) Food values have larger and more consistent effects on food behavior than personality traits.Avhandlingen omhandler effekter av personlighetsfaktorer og matverdier på matrelatert atferd. Det blir brukt tverrsnittsdata fra Norsk Monitor (NM) i 2015 og fra en internettbasert spørreundersøkelse (IS) som ble gjennomført i 2015 i Norge og USA. En norsk versjon av Femfaktormodellen, som er basert på 20 spørsmål, blir brukt for å måle de fem personlighetsfaktorene åpenhet, planmessighet, ekstroversjon, omgjengelighet og nevrotisisme. De tolv matverdiene som måles er naturlighet, trygghet, miljøpåvirkning, opprinnelse, rettferdighet, ernæring, smak, utseende, enkelhet, pris, dyrevelferd og nyhet. IS kartlegger hvilke matverdier forbrukerne har ut fra «best-worst scaling»-metoden. NM bruker en forenklet utgave av metoden. Det er fire hovedfunn i avhandlingen. (1) Personlighetsfaktorene påvirker preferansestrukturen for matverdier. Åpenhet og omgjengelighet er assosiert med mer altruistiske preferanser. (2) Effektene av personlighetsfaktorene på holdningene til genmodifisert mat er verken store eller konsistente over produkter eller datasett. Matverdiene er viktigere for holdningene til genmodifisert mat. En stor del av motstanden mot genmodifisert mat er tilsynelatende basert på oppfatninger om at disse produktene er mindre naturlige, mindre rettferdige overfor deltakerne i matforsyningskjeden, farligere for miljøet og negative for dyrevelferden. (3) Kostholdsmønstre reflekterer forskjeller i personlighetsfaktorer og matverdier. Åpne og mer omgjengelige respondenter velger kostholdsmønstre som de tror har lavere miljøpåvirkning, er mer rettferdig overfor bønder, matindustri og dagligvarehandel og beskytter lokal matproduksjon. (4) Matverdiene har større og mer konsistente effekter på matrelatert atferd enn personlighetsfaktorene

Process Simulation: When Programming is Easier Than User-Friendly Packages

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Evaluation of electroless nickel-phosphorus (EN) coatings

The utilization of Electroless Nickel-Phosphorus (EN) coatings has witnessed a staggering increase during the last two decades. Many outstanding characteristics of the EN coating method have generated a lot of interest in various industries including oil and gas, electronic, chemical, automotive, aerospace, and mining. Some of the highlighted characteristics of EN coatings are superior corrosion and wear resistance especially in environments containing H2S and CO2, superior mechanical properties, uniform coating thickness, excellent surface finish properties, superb adhesion characteristics, and wide range of thickness. The EN coating process is based on a redox reaction in which a reducing agent is oxidized and Ni+2 ions are reduced on the surface of the substrate materials. Once the first layer of Ni is deposited, it acts as a catalyst for the process. Consequently, a linear relationship between coating thickness and time usually occurs. If the reducing agent is sodium hypophosphite, the deposit obtained will be a nickel-phosphorus alloy. The objective of this research was to evaluate various properties of three types of EN coatings, namely, low, medium, and high phosphorus. In the first phase of this work an automated prototype EN bath was designed and engineered. As a result, three types of EN coatings were deposited on various substrates. In the second phase of this research, various qualitative and quantitive methods were implemented to evaluate various properties of EN coatings. Also, the effects of various coating parameters including coating thickness and phosphorus content on properties of EN coatings were comprehensively investigated. Furthermore, the effect of post heat treatment on various properties of EN coatings was studied. Heat treatment on EN deposits in the range of 300-400 °C for one hour caused the hardness to increase due to the formation of various types of nickel phosphide (NixPy). The results of this study showed that various properties of EN coatings are directly related to the phosphorus content of the coatings. EN coatings with lower phosphorus content are crystalline, hard and brittle. As a result, they have superior wear resistance. On the other hand, EN coatings with higher phosphorus content are amorphous with superior corrosion resistance. iii EN coatings in general have excellent adhesion properties. However, the degree of adhesion is affected by several parameters including coating thickness, phosphorus content, post heat treatment, and ductility of the substrate. Moreover, it was shown that due their brittle nature EN coatings in general and heat-treated low phosphorus EN coating in particular have a detrimental effect on fatigue properties of their substrates. It was also shown that EN coatings in general, improve the kinetic coefficient of friction. In other words, EN coatings exhibit a self-lubricating behavior. Also, it was shown that EN coatings completely follow the surface profile of their substrate unlike conventional electroplating. Corrosion and wear studies on EN coatings revealed that EN coatings are excellent candidates for materials subjected to excessive corrosion and wear in a potash brine environment. Finally, the microstructure study of EN coatings using TEM and STEM electron microscopy revealed valuable information regarding the phase transformation during the heat treatment. It was shown that heat treatment at 400°C for one hour caused the precipitation of various nickel phosphide particles. As a result, significant changes in various properties of EN coatings occurred

Application of silicon-polymer composite varistors to protect sensitive medical imaging circuits and performing better voltage bias for SiPMs

Nowadays, Silicon photomultipliers (SiPM) become a reasonable choice for Time-of-Flight Positron Emission Tomography (TOF-PET). To achieve the best performance of SiPMs, it is necessary to adjust a suitable voltage bias. In this article, we are using varistors which protect SiPM from voltage fluctuations. The silicon-polymer composite varistors prepared using hot press method have been investigated. Research on (current-voltage) characteristics of samples shows that by increasing silicon content in the mixture, the breakdown voltage decreases from 110 V to 70 V. The results also show that increasing silicon content decreases the potential barrier height from 0.29 eV to 0.26 eV, however, leakage current increases. Increasing silicon content increases nonlinear coefficient from 4.1 to 4.8. Using these techniques gives us ability to produce suitable surge protector for medical imaging modalitie

Iranian Consumers’ Willingness to Pay for Fresh Fish

This paper explores attitudes and willingness to pay (WTP) for Norwegian salmon, Iranian rainbow trout, and Iranian narrow-barred Spanish mackerel among Iranian consumers. An interval regression model found that consumption frequency and product attributes affected WTP. Salmon was ranked highest on taste, nutrition, and convenience but lowest on price. The average estimated WTP for salmon was US $14.82, which is higher than for the other species but below the market price. The main challenges for salmon exporters will be to reduce the current high price and to differentiate salmon further in the market

A Comparative Study of the Optimum Tuned Mass Damper for High-rise Structures Considering Soil-structure Interaction

The present paper focuses on the optimum design of tuned mass damper (TMD) as a device for control of the structures. The optimum free vibration parameters such as period and damping ratio depend on the soil condition. For this reason, the seven meta-heuristic algorithms namely colliding bodies optimization (CBO), enhanced colliding bodies optimization (ECBO), water strider algorithm (WSA), dynamic water strider algorithm (DWSA), ray optimization (RO) algorithm, teaching-learning-based optimization (TLBO) algorithm and plasma generation optimization (PGO) are used to find the TMD parameters considering soil-structure interaction (SSI) effects. These optimization methods are applied to a benchmark 40-story structure. For comparison, the obtained results of these algorithms are compared. The capability and robustness of the algorithms are investigated through the benchmark problem. The results are shown that the soil type affects the optimum values of the TMD parameters, especially for the soft soil. To evaluate the performance of the obtained parameters in both the frequency and time domains, time history displacement and acceleration transfer function of the top story of the structure are calculated for the model with and without considering the SSI effects

New Techniques for Thermo-electrochemical Analysis of Lithium-ion Batteries for Space Applications

The overall goal of this study was achieved: Replicated the numerical assessment performed by Chen et. al. (2005). Displayed the ability of Thermal Desktop to be coupled with thermo-electrochemical analysis techniques. such that the local heat generated on the cells is a function of the model itself using logic blocks and arrays. Differences in the TD temperature vs. depth of discharge profiles and Chen's was most likely due to differences in two primary areas: Contact regions and conductance values. Differences in density and specific heat values. center dot The model results are highly dependent on the accuracy of the material properties with respect to the multiple layers of an individual cell