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•Kosmotropes induce the aggregation and fusion of PEG-liposomes.•The effect depends on both the kosmotrope and PEG concentration.•Aggregation is reversible under certain ...conditions.•Kosmotropes lead to a dehydration-related conformational change of the PEG polymer.•The likely driving force behind aggregation is the hydrophobic effect.
Polyethylene glycol (PEG) is widely used to sterically stabilize liposomes and improve the pharmacokinetic profile of drugs, peptides and nanoparticles. Here we report that ammonium sulfate (AS) can evoke the aggregation of PEGylated vesicles in a concentration-dependent manner. Liposomes with 5mol% PEG were colloidally stable at AS concentrations up to 0.7mM, above which they precipitated and formed micron-size aggregates with irregular shape. While aggregation was reversible up to 0.9M of AS, above 1M fusion occurred, which irreversibly distorted the size distribution. Zeta potential of liposomes markedly increased from −71±2.5mV to 2±0.5mV upon raising the AS concentration from 0 to 0.1M, but no considerable increase was seen during further AS addition, showing that the aggregation is independent of surface charge. There was no aggregation in the absence of the PEG chains, and increasing PEG molar% shifted the aggregation threshold to lower AS concentrations. Changes in the FTIR spectral features of PEGylated vesicles suggest that AS dehydrates PEG chains. Other kosmotropic salts also led to aggregation, while chaotropic salts did not, which indicates a general kosmotropic phenomenon. The driving force behind aggregation is likely to be the hydrophobic effect due to salting out the polymer similarly to what happens during protein purification or Hydrophobic Interaction Chromatography. Since liposome aggregation and fusion may result in difficulties during formulation and adverse reaction upon application, the phenomena detailed in this paper may have both technological and therapeutical consequences.
Introduction: Current research on sport motivation mostly focuses on the Self-Determination Theory, which has brought a qualitatively novel approach in the field by making a distinction between six ...types of motivation. The present study tested the reliability and validity of the Hungarian adaptation of the Sport Motivation Scale II (SMS-II) with a large sample of athletes. The assessment of the psychometric properties focused on the factor structure, construct validity and convergent validity of the Hungarian version. Methods: The sample included 1197 Hungarian athletes aged 11 to 67 years, who engaged in more than 50 different sports. The test battery comprised the Hungarian adaptations of the SMS-II, the Satisfaction With Life Scale (SWLS-H), the Rosenberg Self-Esteem Scale (RSES), the Competitive State Anxiety Inventory 2 (CSAI-2), and the Flow State Questionnaire (PPL-FSQ). Results: Considering that each subscale of the SMS-II consists of only three items, all subscales showed acceptable internal consistency. A confirmatory factor analysis revealed that the original six-factor model showed the best fit with the data. All fit indices obtained for this model fell within the acceptable range. The examination of construct validity revealed the expected simplex pattern of the subscales, while the associations between the SMS-II and the measures used to test convergent validity were consistent with those obtained in previous studies. Discussions: The Hungarian version of the SMS-II provides a reliable and valid measure of sport motivation based on the Self-Determination Theory. The only inconsistency between the observed data and the theoretical model was that intrinsic motivation did not show a closer association with integrated regulation than with identified regulation, which finding is probably related to the contents of the involved subscales. Conclusions: A possible future direction of construct validity analysis and improvement may be focused on content refinement. Specifically, the construct validity of the Hungarian SMS-II could possibly be improved by completing the items assessing intrinsic motivation with references to the positive experience directly related to the activity itself.
We present a new grid of model photospheres for the SDSS-III/APOGEE survey of stellar populations of the Galaxy, calculated using the ATLAS9 and MARCS codes. New opacity distribution functions were ...generated to calculate ATLAS9 model photospheres. MARCS models were calculated based on opacity sampling techniques. The metallicity (M/H) spans from -5 to 1.5 for ATLAS and -2.5 to 0.5 for MARCS models. There are three main differences with respect to previous ATLAS9 model grids: a new corrected H2O line list, a wide range of carbon (C/M) and alpha element alpha /M variations, and solar reference abundances from Asplund et al. The added range of varying carbon and alpha -element abundances also extends the previously calculated MARCS model grids. Altogether, 1980 chemical compositions were used for the ATLAS9 grid and 175 for the MARCS grid. Over 808,000 ATLAS9 models were computed spanning temperatures from 3500 K to 30,000 K and log g from 0 to 5, where larger temperatures only have high gravities. The MARCS models span from 3500 K to 5500 K, and log g from 0 to 5. All model atmospheres are publicly available online.
The Sloan Digital Sky Survey III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a three-year survey that is collecting 10 super(5) high-resolution spectra in the ...near-IR across multiple Galactic populations. To derive stellar parameters and chemical compositions from this massive data set, the APOGEE Stellar Parameters and Chemical Abundances Pipeline (ASPCAP) has been developed. Here, we describe empirical calibrations of stellar parameters presented in the first SDSS-III APOGEE data release (DR10). These calibrations were enabled by observations of 559 stars in 20 globular and open clusters. The cluster observations were supplemented by observations of stars in NASA's Kepler field that have well determined surface gravities from asteroseismic analysis. We discuss the accuracy and precision of the derived stellar parameters, considering especially effective temperature, surface gravity, and metallicity; we also briefly discuss the derived results for the abundances of the alpha -elements, carbon, and nitrogen. Overall, we find that ASPCAP achieves reasonably accurate results for temperature and metallicity, but suffers from systematic errors in surface gravity. We derive calibration relations that bring the raw ASPCAP results into better agreement with independently determined stellar parameters. The internal scatter of ASPCAP parameters within clusters suggests that metallicities are measured with a precision better than 0.1 dex, effective temperatures better than 150 K, and surface gravities better than 0.2 dex. The understanding provided by the clusters and Kepler giants on the current accuracy and precision will be invaluable for future improvements of the pipeline.
Objectives: To examine the hypothesis that glyceryl trinitrate (GTN) may cause headache in patients with normal coronary arteries more often than in patients with obstructive coronary artery disease ...(CAD). This simple assessment may aid clinicians in the initial evaluation of chest pain syndrome and possible CAD. Patients and methods: 118 patients (66 men and 52 women) with new onset of chest pain were enrolled in this study. Patients were excluded from the study if they had a history of chronic headache, long term nitrates use, or any coronary artery procedures. Mean age of the patients was 62.5 years. Coronary angiography was performed within one month of GTN administration with the usual clinical indications such as recurrent chest pain, abnormal ECG, or abnormal results of stress tests. Thirty patients had normal coronary arteries or minimal or non-obstructive CAD. Eighty eight patients had obstructive CAD defined as luminal narrowing greater than 50% in any one or more of the left or right coronary arteries or their major branches. All the patients had a varying degree of relief of chest pain with GTN administration within 10 minutes. 36% of patients reported significant headache after GTN administration. Results: In patients with normal coronary arteries or minimal CAD, 73% had significant headache caused by sublingual GTN. In patients with obstructive CAD, only 23% had significant headache after GTN use (p < 0.001). There were no differences in patients’ sex and vascular risk factors concerning the frequency of headache in patients with or without obstructive CAD. Conclusions: GTN causes significantly more frequent headache episodes in patients with normal coronary arteries or minimal CAD than in patients with obstructive CAD. This unique finding may provide clinicians with an additional tool for the differential diagnosis of patients with chest pain syndrome.
Abstract
We discuss the self-enrichment scenario by asymptotic giant branch (AGB) stars for the formation of multiple populations in globular clusters (GCs) by analysing data set of giant stars ...observed in nine Galactic GCs, covering a wide range of metallicities and for which the simultaneous measurements of C, N, O, Mg, Al, and Si are available. To this aim, we calculated six sets of AGB models, with the same chemical composition as the stars belonging to the first generation of each GC. We find that the AGB yields can reproduce the set of observations available, not only in terms of the degree of contamination shown by stars in each GC but, more important, also the observed trend with metallicity, which agrees well with the predictions from AGB evolution modelling. While further observational evidences are required to definitively fix the main actors in the pollution of the interstellar medium from which new generation of stars formed in GCs, the present results confirm that the gas ejected by stars of mass in the range $4\, \rm M_{{\odot }} \le \it M \le 8\, \rm M_{{\odot }}$ during the AGB phase share the same chemical patterns traced by stars in GCs.
Soil organic carbon （SOC） has primary importance in terms of soil physics, soil fertility and even of climate change control. One hundred soil samples were taken from an intensively cultivated ...Cambisol to quantify SOC redistribution triggered by soil erosion under a subhumid climate, by the simultaneous application of diffuse reflectance （240-1 900 nm） and traditional physico-chemical methods. The representative sample points were collected from the solum along the slopes at the depth of 20-300 cm with a mean SOC content of 12 g kg-1. Hierarchical cluster analyses were performed based on the determined SOC results. The spatial pattern of the groups created were similar, and even though the classifications were not the same, diffuse reflectance had proven to be a suitable method for soil/sediment classification even within a given arable field. Both organic and inorganic carbon distributions were found to be a proper tool for estimations of past soil erosion processes. The SOC enrichment was found on two sedimentary spots with different geomorphological positions. Soil organic matter composition also differed between the two spots due to selective deposition of the delivered organic matter. The components with low-molecular-weight reached the bottom of the slope where they could leach into the profile, while the more polymerised organic matter compositions were delivered and deposited even before on a higher segment of the slope in an aggregated form. This spatial difference appeared below the uppermost tilled soil layer as well, referring the lower efficiency of conventional ploughing tillage in soil spatial homogenisation.
Purpose
Reduced functional mobility is a risk factor for falls. The Timed Up and Go test is a complex measurement tool for functional mobility. Our aims were to assess the functional mobility of: ...(a) community-living elderly who were participating in an exercise programme (
n
= 40; mean age = 73.7 years), (b) community-living elderly who were physically inactive (
n
= 40; mean age = 74.1 years), and (c) institutionalized elderly (
n
= 40; mean age = 73.5 years) and to compare the results with cut-off values for risk of fall.
Materials and methods
After measuring functional mobility, one-way independent ANOVAs and sample
t
-tests were used for analysis.
Results
The functional mobility of the active participants was better than that of the inactive (
p
< .001) and institutionalized participants (
p
< .001). There was no significant difference between the inactive and institutionalized participants (
p
= .990). The functional mobility of the active participants was better, whereas the functional mobility of the inactive participants was worse than the cut-off value of 13.5 s for risk of fall for community-living elderly. The functional mobility of the institutionalized participants did not differ from the 15-s reference value for predicting risk of fall.
Conclusion
The results indicate that regular physical activity has a positive effect on maintaining functional mobility among both community-living and institutionalized elderly individuals.
The authors describe the case history of a patient who suffered from symptoms deriving from two different origins. The patient's voice was spasmodic dysphonia-like interrupted and pressed. At the ...same time, his voice was powerless, too. The reason for this was that besides the spasmodic dysphonia caused by hyperkinesis, an incomplete closure of the vocal cords during phonation in the middle third was present. It was caused by the atrophy of the vocal cords. In order to eliminate the symptoms, initially we injected 25 IU Botox into the left vocal cord transcutaneously under the direction of EMG control. It resulted in a fluent, though breathy voice. In order to manage the closing insufficiency during phonation, we performed lipoaugmentation on the left vocal cord under high-frequency jet anaesthesia. The result of the two-step procedure was a fluent and clear voice. The speech without interruption lasted for 5 months, until the drug was eliminated. Of course, to prolong the result, the Botox injection should be repeated.
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