DIBENZO-18-CROWN-6/POLYCAPROLACTONE COMPOSITE NANOFIBERS FOR SELECTIVE ADSORPTION OF CATIONS

Electrospun nanofibers are attractive alternatives to traditional adsorbents due to their high surface-to-volume ratio, porosity, and loading capacity. Functionalization of nanofibers with macrocycles can contribute to further enhancement in selective adsorption of ions. In this study, polycaprolactone (PCL) nanofibers were functionalized with a crown ether, namely dibenzo-18-crown-6 (DB18C6), and the potential of the resultant electrospun PCL/DB18C6 nanofibers for selective ion adsorption, particularly the selective recovery for K+, was investigated. The morphology, chemical structure and thermal properties of PCL/DB18C6 nanofibers were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The average diameter of PCL/DB18C6 nanofibers was 529±196 nm. Single-ion adsorption experiments indicated that the adsorption capacity for K+ ion was 137 mg·g−1 and the selectivity sequence was found as K+>Ca2+>Na+. The adsorption selectivity coefficients of K+/Ca2+ and K+/Na+ were calculated respectively as 1.37 and 4.28 for single ion experiments and as 1.13 and 5.11 for mixed ion adsorptions which illustrate that the difference between the adsorption capacities of K+ and Ca2+ decreased in mixed ion adsorption experiments. Overall results demonstrate that the electrospun PCL/DB18C6 nanofibers are amenable for use as polymer adsorbents for the selective ion recovery

Mindfulness: A Current Review

The concept of mindfulness, defined by Kabat-Zinn, refers to a mechanism where the experiences are always at the center of attention. This concept, which dates back almost 2500 years, attracted the attention of several researchers in recent years. It was suggested that mindfulness could contribute to the treatment of psychopathologies and various intervention methods were developed. On the other hand, there are also studies on the action mechanisms of these intervention methods in the literature. The present literature review aimed to describe the concept of mindfulness, to investigate the correlations between mindfulness and psychopathologies and transdiagnostic variables, and to provide a general framework on awareness skills and techniques designed to develop these skills

The Effect of Quantum Learning Model on Science Teacher Candidates’ Self-Efficacy and Communication Skills

The aim of this study was to investigate the effect of quantum learning model on science teacher candidates’ self-efficacy and communication skills. One group pre-test post-test experimental design was performed in the study. The research was carried out with 20 teacher candidates having education in third grade of Division of Science Education in Ahi Evran University. A total of 16 hours’ seminar was given to the teacher candidates in the research group about “Quantum Learning Model” and the techniques used in quantum learning model. The application of the research was performed in 8 weeks and in a total of 32 hours with laboratory experiments arranged in accordance with the “Quantum Learning Model” in the course of Science Teaching Laboratory Practices-II. Before and after the experimental studies, “Science Teaching Self-Efficacy Belief Questionnaire” and “Self-Awareness Inventory” were performed on teacher candidates. The obtained data were analyzed by SPSS package program. According to the results of the research, there was no significant difference between the science teacher candidates’ science teaching self-efficacy pre-test and post-test mean scores. Between the mean scores of science teacher candidates in science teaching self-efficacy pre-test and post-test, there was a significant difference in favor of post-test

Electrospun nanofibers for skin-contact applications

The use of nanofibers is expanding from academic into industry as these lightweight and highly porous materials are advantageous in many application areas. The main objectives of this roject is to reveal the potential of the bioeconomy in Europe, to decrease the use of fossil-based products, lead to greener and more environmentally friendly growth by fighting against climate change. For this purpose, nonwovens are prepared from bio-based polymers using solution electrospinning method for cosmetics and wound-care applications

An Empirical Evaluation of the Relationship between Trade Openness and External Debt: Turkish Case

This paper aims to analyze the empirical relationship between trade openness and external debt for the Turkish economy, using quarterly time series data from the 1990:1- 2012:2 periods. We utilize the bounds testing procedure to establish the cointegration relationship among variables and the ARDL analysis to detect short run and log run static effects. We support the results from the ARDL model through the application of GMM estimation, achieved with different model definitions. Empirical results indicate that increasing trade openness affects external debt positively in both the short run and long run

A combined 32‐channel receive‐loops/8‐channel transmit‐dipoles coil array for whole‐brain MR imaging at 7T

Purpose Multichannel receive arrays provide high SNR and parallel‐imaging capabilities, while transmit‐only dipole arrays have been shown to achieve a large coverage of the whole‐brain including the cerebellum. The aim of this study was to develop and characterize the performances of a 32‐channel receive‐only loop array combined with an 8‐channel dipole coil array at 7T for the first time. Methods The 8Tx‐dipoles/32Rx‐loops coil array was characterized by the SNR, g‐factors, noise correlation matrix, accelerated image quality, and urn:x-wiley:07403194:media:mrm27808:mrm27808-math-0003 maps, and compared with a commercial 1Tx‐birdcage/32Rx‐loops array. Simulated and measured urn:x-wiley:07403194:media:mrm27808:mrm27808-math-0004 maps were shown for the 8Tx‐dipoles/32Rx‐loops coil array and compared with the 8Tx/Rx dipole array. Results The in‐house built 32‐channel receive coil demonstrated a large longitudinal coverage of the brain, particularly the upper neck area. G‐factors and accelerated MR acquisitions demonstrated robust performances up to R = 4 in 2D, and R = 8 (4 × 2) in 3D. A 83% increase in SNR was measured over the cerebellum with the in‐house built 8Tx/32Rx coil array compared to the commercial 1Tx/32Rx, while similar performances were obtained in the cerebral cortex. Conclusions The combined 32‐channel receive/8‐channel transmit coil array demonstrated high transmit‐receive performances compared to the commercial receive array at 7T, notably in the cerebellum. We conclude that in combination with parallel transmit capabilities, this coil is particularly suitable for whole‐brain MR studies at 7T

Preclinical evaluation of scorzonera sp root extracts and major compounds against acute hepatotoxicity induced by carbon tetrachloride

WOS: 000419284200007Evaluation of hepatoprotective activities of Scorzonera roots and their major compounds, was aimed in current study. Scorzonera latifolia, S. tomentosa, S. mollis ssp. szowitsii, S. parviflora and S. cana var. jacquiniana roots, methanol-water (80:20) extracts together with chlorogenic acid, scorzotomentosin-4'-O-beta-glucoside, hydrangenol-8-O-beta-glucoside as major compounds isolated from S. latifolia roots were tested for their hepatoprotective activities. Sprague Dawley rats were used for experiment and hepatotoxicity was induced by carbon tetrachloride. Aspartate aminotransferase and alanine aminotransferase levels were measured and all results were confirmed by histopathological examination. Plasma aspartate aminotransferase and alanine aminotransferase levels of examined groups were not significant when compared to carbon tetrachloride-treated groups. However histopathological results have revealed that all tested groups have less damage when compared to carbon tetrachloride group except scorzotomentosin-4'-O-beta-glucoside and hydrangenol-8-O-beta-glucoside groups. Scorzonera species displayed moderate hepatoprotective activities against carbon tetrachloride induced acute toxicity. Chlorogenic acid, among tested compounds exhibited higher activity than all tested Scorzonera species as well as other isolated compounds. Therefore chlorogenic acid could be suggested as responsible compound

Investigation of Carbapenemase Resistance Genes in Multidrug-Resistant Providencia rettgeri Strains

Objectives: Resistant bacterial pathogens are important causes of both community and healthcare associated infections. Providencia genus are Gram-negative bacilli in the Enterobacterales order, which mostly cause urinary tract infections. P.rettgeri is known to be a causative agent of catheter-related urinary system infections, especially in patients hospitalized in the intensive care unit recently. As with other resistant bacteria, the spread of hospital infections caused by Providencia species is mostly blamed on the failure of healthcare personnel to comply with infection control measures. Methods: In our study, a total of 22 multi-drug resistant P. rettgeri strains isolated from urine culture samples of 11 (50%) male and 11 (50%) female inpatients in our hospital between November 2017 and November 2021 were examined. Bacteria were evaluated for the presence of resistance genes by the mCIM, the BD Phoenix CPO detect panel, and conventional PCR. Results: By mCIM test, 18 (81.8%) strains were positive, three (13.6%) strains were negative, and one (4.6%) strain was indeterminate. All strains were identified as “class B carbapenemase producer” with the BD Phoenix CPO detection kit. With conventional PCR, OXA-48, IMP, VIM and KPC genes were not found to be positive in any of the strains, while all of the strains were found to be positive for the blaNDM gene. Conclusion:NDM is among class B carbapenemases and is common in the Enterobacteralesfamily. P. rettgeri has recently been recognized as the key organism in the spread of NDM-1. It is very important to control the spread of this bacteria, which has resistance genes that can be transferred with plasmids against many antibacterials in hospitals. Our study shows that it is necessary to follow these strains in our hospital and take necessary infection control measures to prevent their spread