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In this work, we examined the effect of the length of alkyl chain attached to the benzene ring on the self-assembling phenomena for a series of phenyl alcohol (PhA) derivatives, from phenylmethanol (benzyl alcohol) to 7-phenyl-1-heptanol, by means of X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR) spectroscopy, and Broadband Dielectric Spectroscopy (BDS) methods. XRD data in the reciprocal and real spaces showed a gradual increase in the local order with the elongation of the alkyl chain. However, the position and full width at half maximum of the main diffraction peak exhibited a non-systematic behavior. To better understand this fact, PhAs were subjected to FTIR spectroscopic studies. These investigations revealed that the association degree and the activation energy of dissociation increase as the alkyl chain length grows. On the other hand, BDS data showed a non-monotonic variation in the Kirkwood correlation factor with increasing length of the alkyl chain, indicating a competition between interactions of the non-polar and polar parts of the molecules in the studied PhAs. Finally, it was also found that the molar surface entropy for PhAs increases with the number of methylene groups, approaching values reported for alkanes, which indicates suppression of the surface order for PhAs with a long alkyl chain. This variability of the various parameters as a function of the length of the side chain shows that the interplay between soft interactions has a strong impact on the local structure and intra and intermolecular dynamics of the studied PhAs. [ABSTRACT FROM AUTHOR]

Since 2005 December, recurrent outbursts have been observed for Centaur 174/P Echeclus, confirming it is an active object. Thanks to a large number of photometric data obtained between 2001 April and 2019 December, we were able to compute a shape model of this object. We obtain a sidereal rotation period P  = 26.785178 ± 10−6 h and six equally probable pole solutions, each with a large obliquity of the rotational axis (50° or more). We also find the object significantly elongated, with a semi-major axial ratio a / b  = 1.32 (and b / c ∼ 1.1 but this second ratio is poorly constrained by the photometric data). Additionally, we present a detailed analysis of the dust emission from the 2016 outburst. Different colour maps are presented that reveal a change in dust colour, which becomes bluer with increasing cometocentric distance. A blue ring-like structure around the nucleus clearly visible in the images obtained on October 4 in the V-R spectral interval points out that the innermost near nucleus region is considerably redder than the surrounding coma. Different jets are also apparent, the main one being oriented southward. A detailed dynamical study is done to investigate past and future orbital elements. These elements appear stable in the period ≈1200 CE to ≈2900 CE. For a period of 12 000 yr the main conclusion is that Echeclus' perihelion distance was greater than about 4 au, preventing it from following a typical cometary activity like a short-period comet. Close encounters with giant planets nevertheless prevent any study of orbital elements on longer timescale. [ABSTRACT FROM AUTHOR]

Pressure-Volume-Temperature (PVT) measurements and broadband dielectric spectroscopy were carried out to investigate molecular dynamics and to test the validity of thermodynamic scaling of two homologous compounds of pharmaceutical activity: itraconazole and ketoconazole in the wide range of thermodynamic conditions. The pressure coefficients of the glass transition temperature (dTg/dp) for itraconazole and ketoconazole were determined to be equal to 183 and 228 K/GPa, respectively. However, for itraconazole, the additional transition to the nematic phase was observed and characterized by the pressure coefficient dTn/dp = 258 K/GPa. From PVT and dielectric data, we obtained that the liquid-nematic phase transition is governed by the relaxation time since it occurred at constant tα = 10-5 s. Furthermore, we plotted the obtained relaxation times as a function of T-1u-γ, which has revealed that the validity of thermodynamic scaling with the exponent equals to 3.69 ± 0.04 and 3.64 ± 0.03 for itraconazole and ketoconazole, respectively. Further analysis of the scaling parameter in itraconazole revealed that it unexpectedly decreases with increasing relaxation time, which resulted in dramatic change of the shape of the thermodynamic scaling master curve. While in the case of ketoconazole, it remained the same within entire range of data (within experimental uncertainty). We suppose that in case of itraconazole, this peculiar behavior is related to the liquid crystals' properties of itraconazole molecule. [ABSTRACT FROM AUTHOR]

Chemically peculiar (CP) stars of the upper main sequence are characterized by specific anomalies in the photospheric abundances of some chemical elements. The group of CP2 stars, which encompasses classical Ap and Bp stars, exhibits strictly periodic light, spectral, and spectropolarimetric variations that can be adequately explained by the model of a rigidly rotating star with persistent surface structures and a stable global magnetic field. Using observations from the Kepler K2 mission, we find that the B9pSi star HD 174356 displays a light curve variable in both amplitude and shape, which is not expected in a CP2 star. Employing archival and new photometric and spectroscopic observations, we carry out a detailed abundance analysis of HD 174356 and discuss its photometric and astrophysical properties in detail. We employ phenomenological modelling to decompose the light curve and the observed radial velocity variability. Our abundance analysis confirms that HD 174356 is a silicon-type CP2 star. No magnetic field stronger than 110 G was found. The star's light curve can be interpreted as the sum of two independent strictly periodic signals with |$P_1=4{_{.}^{\rm d}}043\, 55(5)$| and |$P_2=2{_{.}^{\rm d}}111\, 69(3)$|⁠. The periods have remained stable over 17 yr of observations. In all spectra, HD 174356 appears to be single-lined. From the simulation of the variability characteristics and investigation of stars in the close angular vicinity, we put forth the hypothesis that the peculiar light variability of HD 174356 arises in a single star and is caused by rotational modulation due to surface abundance patches (P 1) and g-mode pulsation (P 2). [ABSTRACT FROM AUTHOR]

Context. Blue supergiant stars are known to display photometric and spectroscopic variability that is suggested to be linked to stellar pulsations. Pulsational activity in massive stars strongly depends on the star's evolutionary stage and is assumed to be connected with mass-loss episodes, the appearance of macroturbulent line broadening, and the formation of clumps in the wind. Aims. To investigate a possible interplay between pulsations and mass-loss, we carried out an observational campaign of the supergiant 55 Cyg over a period of five years to search for photospheric activity and cyclic mass-loss variability in the stellar wind. Methods. We modeled the H, He i, Si ii, and Si iii lines using the nonlocal thermal equilibrium atmosphere code FASTWIND and derived the photospheric and wind parameters. In addition, we searched for variability in the intensity and radial velocity of photospheric lines and performed a moment analysis of the line profiles to derive frequencies and amplitudes of the variations. Results. The Hα line varies with time in both intensity and shape, displaying various types of profiles: P Cygni, pure emission, almost complete absence, and double or multiple peaked. The star undergoes episodes of variable mass-loss rates that change by a factor of 1.7-2 on different timescales. We also observe changes in the ionization rate of Si ii and determine a multiperiodic oscillation in the He i absorption lines, with periods ranging from a few hours to 22.5 days. Conclusions. We interpret the photospheric line variations in terms of oscillations in p-, g-, and strange modes. We suggest that these pulsations can lead to phases of enhanced mass loss. Furthermore, they can mislead the determination of the stellar rotation. We classify the star as a post-red supergiant, belonging to the group of α Cyg variables. [ABSTRACT FROM AUTHOR]

The Kepler space mission provided near-continuous and high-precision photometry of about 207 000 stars, which can be used for asteroseismology. However, for successful seismic modeling it is equally important to have accurate stellar physical parameters. Therefore, supplementary ground-based data are needed. We report the results of the analysis of high-resolution spectroscopic data of A- and F-type stars from the Kepler field, which were obtained with the HERMES spectrograph on the Mercator telescope. We determined spectral types, atmospheric parameters and chemical abundances for a sample of 117 stars. Hydrogen Balmer, Fe i, and Fe ii lines were used to derive effective temperatures, surface gravities, and microturbulent velocities. We determined chemical abundances and projected rotational velocities using a spectrum synthesis technique. The atmospheric parameters obtained were compared with those from the Kepler Input Catalogue (KIC), confirming that the KIC effective temperatures are underestimated for A stars. Effective temperatures calculated by spectral energy distribution fitting are in good agreement with those determined from the spectral line analysis. The analysed sample comprises stars with approximately solar chemical abundances, as well as chemically peculiar stars of the Am, Ap, and À Boo types. The distribution of the projected rotational velocity, usin i, is typical for A and F stars and ranges from 8 to about 280 km s-1, with a mean of 134 km s-1. [ABSTRACT FROM AUTHOR]

We present spectroscopic and photometric analysis of the quintuple star HD 86222 with an eclipsing component. Until now three visual components A, B, and C of this multiple star were known. Four components in the A/B pair were detected during the examination of the cross correlation functions obtained from the spectra. We noticed that the visual components A and B, separated by 0".5, are in fact two binary stars - one eclipsing pair and one spectroscopic system. The pair with higher radial velocity amplitude corresponds to the eclipsing period. Photometric and spectroscopic observations of the eclipsing binary enable us to obtain the Wilson-Devinney model. The masses of this pair are M1 = 1.29 ±0.09 M☉ and M2= 1.33 ±0.09 M☉, respectively. The radii, slightly higher than for the main sequence stars, are R1 = 1.35 ±0.01 R☉ and R2= 1.36 ±0.01 R☉, respectively. The main parameters of the spectroscopic binary are also estimated, but they must be confirmed by future observations because of the uncertainty of the period. The farthest star named C, is 15 arc seconds from the main A and B components. Assuming that this object is gravitationally connected with the A and B binary pairs, HD 86222 has at least five components. [ABSTRACT FROM AUTHOR]

First spectroscopic and new photometric observations of the eclipsing binary FM Leo are presented. The main aims were to determine the orbital and stellar parameters of the two components and their evolutionary stage. First spectroscopic observations of the system were obtained with the David Dunlap Observatory and Poznań Spectroscopic Telescope spectrographs. The results of the orbital solution from radial velocity curves are combined with those derived from the light-curve analysis ( V-band photometry from the All Sky Automated Survey and supplementary observations of eclipses with the 1 and 0.35 m telescopes) to derive orbital and stellar parameters.jktebop, Wilson–Devinney binary modelling codes and a two-dimensional cross-correlation method were applied for the analysis. We find the masses to be and and the radii to be and for primary and secondary stars, respectively. The evolutionary stage of the system is briefly discussed by comparing physical parameters with current stellar evolution models. We find that the components are located at the main sequence, with an age of about 3 Gyr. [ABSTRACT FROM AUTHOR]

V440 Per is a Population I Cepheid with a period of 7.57 d and low-amplitude, almost sinusoidal light and radial velocity curves. With no reliable data on the first harmonic, its pulsation mode identification remained controversial. We obtained a radial velocity curve of V440 Per with our new high-precision and high-throughput Poznań Spectroscopic Telescope. Our data reach an accuracy of 130 m s−1 per individual measurement and yield a secure detection of the first harmonic with an amplitude of . The velocity Fourier phase φ21 of V440 Per is inconsistent at the 7.25σ level with those of fundamental-mode Cepheids, implying that the star must be an overtone Cepheid, as originally proposed by Kienzle et al. Thus, V440 Per becomes the longest-period Cepheid with securely established overtone pulsations. We show that a convective non-linear pulsation hydrocode can reproduce the Fourier parameters of V440 Per very well. The requirement to match the observed properties of V440 Per constrains the free parameters of the dynamical convection model used in the pulsation calculations, in particular the radiative loss parameter. [ABSTRACT FROM AUTHOR]

Reperfusion of ischemic myocardium evokes rapid release of free radicals in experimental models. The aim of the study was to investigate the oxidative stress and antioxidative defense during first minutes after reopening of the infarct related artery in patients treated for acute myocardial infarction. The study group consisted of 15 patients with first ST elevation myocardial infarction (STEMI) due to left anterior descending artery occlusion. The control group included ten patients with stable ischemic heart disease (IHD). Blood samples from coronary sinus were drawn before, immediately after and about 15 min after angioplasty. Activity of superoxide dysmutase (SOD), concentration of glutathione as well as the concentrations of lipid peroxides, malodialdehyde (MDA) and 4-hydroxy-2-nonenal (HNE) were measured. There was significantly higher concentration of MDA and HNE and higher SOD activity in STEMI patients before the reperfusion, as compared to the stable IHD group. After the reperfusion concentration of HNE in erythrocytes from STEMI patients was higher than in IHD group. At the same time the activity of SOD significantly decreased in patients with impaired tissue perfusion (myocardial blush grade <2). In conclusion, there is a slightly higher concentration of oxidative stress parameters in patients with STEMI. Diminished antioxidative defense after reperfusion is associated with impaired myocardial perfusion. [ABSTRACT FROM AUTHOR]

Glycoprotein IIIa (GpIIIa) is a membrane receptor, found in various tissues, that has two alleles: A1 and A2. Signalling cascade of GpIIIa is modulated by enzymes called calpains, proteases that may also influence glucose metabolism. There is one small study that shows a high association of A1/A2 polymorphism with type 2 diabetes mellitus. In our research we planned to evaluate the association of A1/A2 polymorphism with type 2 diabetes in a population of patients with ST elevation acute myocardial infarction (STEMI). The study comprised 352 individuals. From the cohort of patients hospitalised for STEMI we chose 113 patients with diagnosed diabetes (diabetic group) and 118 patients with STEMI and normal glucose metabolism (non-diabetic group). The population group consisted of 121 persons. Genotyping was performed by the restriction fragments length polymorphism (RFLP) method. The frequency of alleles in all groups was in Hardy-Weinberg equilibrium. The percentage of A2 allele carriers was comparable among all groups : 20.4% (diabetic patients), 23.7% (nondiabetic) and 21.5% (control group) ( p>0.05). There was no significant difference in frequency of A2 allele among the groups. We have not observed any association between GpIIIa polymorphism with either type 2 diabetes or STEMI. [ABSTRACT FROM AUTHOR]

Purpose: Prolonged physical training leads to compensatory changes in cardiovascular system. One of the most important of them is cardiac hypertrophy. The knowledge, which factors contribute to cardiomyocyte hypertrophy caused by physical exercise is still incomplete. Interleukin 6 (IL6) secreted by contracting skeletal muscles may affect cardiac hypertrophy and remodeling. The aim of the study was to investigate the role of IL6 in exercise induced cardiac hypertrophy. Material and methods: Female mice lacking functional IL6 gene C57BL6/JIL6-/-tm1Kopf (IL6KO) and age and sex matched controls C57BL6/J (WT) were subjected to 6 week swimming regime. Twenty-four hours after the last training session the mice were sacrificed, hearts were excised and weighed. Two other groups of sex and strain matched mice (9 in each group) not subjected to physical training, were sacrificed and served as controls. Weights of the heart and the left ventricle were related independently to the body weight and the tibia length as measures of hypertrophy. Statistical analysis was performed using multifactorial ANOVA and the Fisher test. Results: There was significantly higher heart/body weight ratio in both groups of mice which were trained as compared to the respective sedentary animals [F(3,30)=31.085 p<0.001] There were, however, no significant differences between respective WT and IL6KO groups. Similar relations were found for the left ventricle and also when the weights of the heart and the LV were related to the tibia length. Conclusion: IL6 is not necessary for cardiac hypertrophy induced by prolonged moderate physical exercise in mice. Additional study is warranted to elucidate this phenomenon. [ABSTRACT FROM AUTHOR]

The Global Astronomical Telescope System is a project managed by the Astronomical Observatory Institute of Adam Mickiewicz University in Poznań (Poland) and it is primarily intended for stellar medium/high resolution spectroscopy. The system will be operating as a global network of robotic telescopes. The GATS consists of two telescopes: PST 1 in Poland (near Poznań) and PST 2 in the USA (Arizona). The GATS project is also intended to cooperate with the BRITE satellites and supplement their photometry with spectroscopic observations. [ABSTRACT FROM PUBLISHER]