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RF exposure during MR exams induces heating of the exposed tissues. Measurement of tympanic membrane temperature with an infrared sensor has been used to estimate noninvasively the global RF-induced temperature rise. In this study, the tympanic membrane temperature was measured before and after having the volunteers lying for 15 minutes with earplugs with neither an RF nor a static magnetic field. Large physiological variations of temperature rise were observed across the volunteers after this dummy “exposure”, showing the low reliability of this metric to measure small temperature rises, that make it problematic for RF-induced temperature rise estimation.

The magnetic hyperfine structure constants have been calculated for low-lying levels in neutral potassium atom taking into account the Bohr--Weisskopf (BW) and Breit--Rosenthal (BR) effects. According to our results the $4p_{1/2}$ state of K~I is free from both BR and BW corrections on the level of the current theoretical uncertainties. Using this finding and the measured values of the $A(4p_{1/2})$ constants, we corrected the nuclear magnetic moments for several short-lived potassium isotopes. The BW correction is represented as a product of atomic and nuclear factors. We calculated the atomic factor for the ground state of K I, which allowed us to extract nuclear factors for potassium $I^\pi = 3/2^+$ isotopes from the experimental data. In this way the application range of the single-particle nuclear model for nuclear-factor calculation in these isotopes has been clarified.

Determination of the loads on the elastic elements of the car suspension is a necessary part of the overall calculation of the car as a complex technical system. Considerable attention is paid to this issue both in fundamental works on automobiles and in educational literature. The authors of works devoted to the problem of car vibrations, in most cases, vibrations are considered from the point of view the smoothness of the movement of the car, which is quite logical because the smoothness of the ride determines many indicators of movement and, first of all, the physical well-being of the driver and passengers as well as the safety of transported fragile goods. In this case, the car is considered as a system with several masses connected by elastic elements. This approach requires reducing the masses and stiffnesses of elastic elements to specific points of the vehicle structure, compiling several differential equations of mass motion and, accordingly, significantly complicates solving a problem that is not always required by specific design problems. This article presents a variant of calculating dynamic loads based on a single-mass dynamic system, in which the sprung masses are considered as a single mass concentrated in the center of mass of the body and resting on elastic suspension elements. The solution of the dynamic problem in this case is much simpler, and the results solving a problem that is not always required by specific design problems. This article presents a variant of calculating dynamic loads based on a single-mass dynamic system, in which the sprung masses are considered as a single mass concentrated in the center of mass of the body and resting on elastic suspension elements. The solution of the dynamic problem in this case is much simpler, and the results of the solution may well satisfy the requirements for the accuracy of calculations, since end obtaining specific formulas for the dynamic factor of the loads on the vehicle structure depending on the speed of the vehicle hitting an obstacle. In addition, knowledge of the maximum deformation of the elastic elements of the suspension makes it possible to optimally determine the required depth of the wheel arches of the car, to calculate the required stiffness of the elastic elements of the axles of the car in accordance with the parts of the weight of the entire car falling on them. Keywords: automobile, elastic elements, vibrations, loads.

Based on the analysis of ancient Russian chronicles, archaeological data and folklore sources, the publication reconstructs the ideas and beliefs of the Eastern Slavs of the Old Russian era associated with wells, which represented in the minds of our ancestors a certain mythological space between the world of people and the sacred underground world. The authors point to the obvious connection of the pagan cult of wells with the cults of water and earth, as well as the ideas of our ancestors about the afterlife. In their opinion, the custom of worshiping wells is one of the oldest traditions in ancient Slavic paganism, which existed for several centuries after the adoption of Christianity.

In the publication, based on the analysis of ancient Russian chronicles, archeological data and folklore sources, the reconstruction of the main stages of the biography of one of the most beloved epic heroes of the Russian people - Dobrynya Malkovich is carried out. The authors presented several hypotheses for the origin of Dobrynya, consistently modeled historical events associated with the main milestones in the biography of the main associate of Prince Vladimir Svyatoslavich. The study emphasizes the exceptional role of Dobrynya in the historical events associated with the coming to power of his nephew in Novgorod and Kiev, as well as in carrying out the religious reforms of Prince Vladimir.

The precision measurements of the ratio between the hyperfine structure constants for the s1/2 and p1/2 states has allowed us to estimate the difference between the hyperfine magnetic anomalies for these levels. This work deals with the retrieval of the absolute values of the hyperfine magnetic anomalies from their difference. Taking into account the correction for the hyperfine magnetic anomaly to the g factor has made it possible to increase the determination accuracy of g factors of short-lived isotopes by more than an order of magnitude.

Heating induced by radio frequency (RF) energy may be generated in tissues near active or passive devices implanted in a patient undergoing magnetic resonance imaging (MRI) examination. Recent normative documents for the assessment of RF energy-induced heating state that the net temperature increase (Δ T ) depends on the physical characteristics of the surrounding tissues and on the squared incident tangential electric field ( E tan( l )). The documents do not address the possible effect of multiple scattering from surrounding reflective interfaces, such as, for example, a plastic enclosure of the container (“phantom”) used for implant testing. In our study, we investigated the effect of multiple scattering on Δ T / E tan( l )2 in relation to the implant location when tested in a phantom filled with a gel. The test implant was a titanium alloy rod of 100 mm in length, used as a reference implant in standard documents. The applied RF was in the 128 MHz band, corresponding to the RF generated in a 3 T MRI system. Both the numerical model and measurement provided substantial evidence that Δ T / E tan( l )2 depends on the distance between the rod and phantom box enclosure. In the numerical model, up to 38% variation of this quantity was observed, suggesting that location of the implant with respect to the phantom enclosure would need to be included as a parameter when evaluating RF-induced heating of implants.

Purpose The purpose of the present study was to develop a numerical workflow for simulating temperature increase in a high-resolution human head and torso model positioned in a whole-body magnetic resonance imaging (MRI) radio-frequency (RF) coil in the presence of a transcranial electric stimulation (tES) setup. Methods A customized human head and torso model was developed from medical image data. Power deposition and temperature rise (ΔT) were evaluated with the model positioned in a whole-body birdcage RF coil in the presence of a tES setup. Multiphysics modeling at 3T (123.2 MHz) on unstructured meshes was based on RF circuit, 3D electromagnetic, and thermal co-simulations. ΔT was obtained for (1) a set of electrical and thermal properties assigned to the scalp region, (2) a set of electrical properties of the gel used to ensure proper electrical contact between the tES electrodes and the scalp, (3) a set of electrical conductivity values of skin tissue, (4) four gel patch shapes, and (5) three electrode shapes. Results Significant dependence of power deposition and ΔT on the skin’s electrical properties and electrode and gel patch geometries was observed. Differences in maximum ΔT (> 100%) and its location were observed when comparing the results from a model using realistic human tissue properties and one with an external container made of acrylic material. The electrical and thermal properties of the phantom container material also significantly (> 250%) impacted the ΔT results. Conclusion Simulation results predicted that the electrode and gel geometries, skin electrical conductivity, and position of the temperature sensors have a significant impact on the estimated temperature rise. Therefore, these factors must be considered for reliable assessment of ΔT in subjects undergoing an MRI examination in the presence of a tES setup.

Urbanization is recognized as an important driver of the diversity and abundance of tree associated insect herbivores, but its consequences for insect herbivory are controversial. A likely source of variability among studies is the insufficient consideration of intra-urban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effect of urbanization and local canopy cover on insect herbivory in the pedunculate oak (Quercus robur) throughout most of its geographic range in Europe. The damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing urbanization around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of urbanization. In contrast, an increase in local canopy cover buffered the negative effect of urbanization on leaf-miners and strengthened its effect on gall-inducers. These results show the complexity of plant-herbivore interactions in urbanized areas, highlighting that the presence of local canopy cover within cities has the potential to attenuate or modify the effect of urbanization on biotic interactions.

Heating induced by radio frequency (RF) energy may appear in tissues near implants located in a human subject undergoing magnetic resonance imaging examination. Lead shielding was proposed to reduce such heating below dangerous levels. In this article, we employed 3-D electromagnetic (EM) and thermal co-simulations to quantify the effectiveness of metallic shielding in the presence of two large sets of nonuniform incident fields at 128 MHz. Specifically, we used a lead EM model (LEM) and computed the RF responses, i.e., the net dissipated power and net temperature increase, above background, at the electrodes. We considered a set of single electrode leads with both straight and helical wires, comparing regular unshielded configurations to different implementations of a metallic shield. The lead length, the relative permittivity of the insulator material, and the lead electrode geometry were all independently varied. For leads with helical wires we observed that: 1) the metallic shield significantly modified the LEM; 2) in most cases, the RF responses substantially increased if metallic shielding was applied; and 3) the net temperature increase in close proximity to the shield can be substantially higher than the net temperature increase in close proximity to the lead electrode. Leads with helical and straight wires exhibited significantly different behavior. Using the results obtained from generic straight wire leads to predict the results for leads with helical wires can be significantly misleading.

Purpose To present a modeling workflow for the evaluation of a lead electromagnetic model (LEM) consisting of a transfer function (TF) and a calibration factor. The LEM represents an analytical relationship between the RF response of a lead and the incident electromagnetic field. The study also highlights the importance of including key geometric details of the lead and the electrode when modeling multi-electrode leads. Methods The electrical and thermal responses of multi-electrode leads with helical and straight wires were investigated using 3D electromagnetic (EM) and thermal co-simulations. The net dissipated power (P) around each lead electrode and the net temperature increase at the electrodes (ΔT) were obtained for a set of incident EM fields with different spatial distributions. A reciprocity approach was used to determine a TF for each electrode based on the results of the computational model. The evaluation of the calibration factors and the TF validation were performed using the linear regression of P versus the LEM predictions. Results P and ΔT were investigated for four multi-electrode leads and four single-electrode leads containing either helical or straight wires. All electrodes of the multi-electrode lead were found to be points of high power deposition and temperature rise. The LEMs for the individual electrodes varied substantially. A significant dependence of the calibration factors on the surrounding tissue medium was also found. Finally, the model showed that the TF, the calibration factor, P and ΔT for multi-electrode leads differ significantly from those for single-electrode leads. Conclusion These results highlight the need to evaluate a LEM for each electrode of a multi-electrode lead as well as for each possible surrounding medium. It is also shown that the results derived from simulations based on simplified single-electrode leads can significantly mislead multi-electrode lead analyses.

The solvent-free sulfur-mediated reactions of phosphinic chlorides with alkyl diamines were developed for the practical synthesis of unknown phosphoryl-substituted 4,5-dihydro-1H-imidazoles, 1,4,5,6-tetrahydropyrimidines, and thioamides. Their good tolerance to functional groups, broad substrate scope, and easy scalability were shown. The chemoselective preparation of a variety of phosphoryl-substituted bis(thioamides) was accomplished via the adjustment of a solvent.

The article was submitted on 01.09.2019. Представлен исторический анализ эволюции мифологического образа медведя в религиозном сознании восточных славян X–XVII вв. Авторы подчеркивают, что тотемистические представления наших предков о медведях-проводниках в царство мертвых начали распространяться в восточнославянских землях лишь с середины X в. под влиянием верований и культов соседних финно-угорских и летто-литовских племен и не были характерны для традиционного восточнославянского язычества. Опираясь на памятники древнерусской письменности и материалы археологических раскопок древнерусских языческих святилищ, авторы очерчивают период зарождения и становления на всех восточнославянских землях мифа о сверхъестественном предке-медведе – защитнике человеческого рода. С помощью археозоологических материалов с раскопок древнерусских поселений домонгольской эпохи, а также нескольких древнерусских письменных документов ими определен период превращения в народном сознании восточных славян мифологического образа медведя из властителя судеб и проводника царства мертвых в одного из лесных бесов. Подчеркивается, что миф о сверхъестественном предке-медведе породил обычай водить дрессированных медведей по улицам древнерусских городов для их очищения от нечистой силы, а также в целях народных гаданий. Авторы приходят к выводу о том, что в сознании наших предков образ медведя прошел несколько этапов: от представления о нем как о племенном тотеме до образа одного из доброжелательных духов, защитника людей от нечистой силы. Отголоски древних языческих воззрений о медведе – языческом божестве сохранились в представлениях восточно-славянских народов вплоть до начала XX в. и нашли свои отражения в народных сказках, легендах, преданиях, традициях. The subject of this study is the evolution of the image of the bear among the Eastern Slavs between the tenth and seventeenth centuries. The authors maintain that totemic ideas about bears as creatures that escort the souls of the deceased to the kingdom of the dead began to spread in the East Slavic lands only from the mid-tenth century. Such ideas were influenced by the beliefs and cults of the neighbouring Finno-Ugric and Baltic tribes and were not characteristic of traditional East Slavic paganism. Based on ancient Russian writings and archaeological excavations into ancient pagan sanctuaries, the authors outline the origin and formation of the myth of the supernatural ancestor bear, the protector of the human race, in all East Slavic lands. With the help of archaeological and zoological materials from the excavations of Russian settlements from the pre-Mongol era, as well as several ancient Russian written documents, the authors determine the period of transformation in the folk mythological consciousness of the Eastern Slavs of the mythological image of the bear from the ruler of destinies and guide in the kingdom of the dead into a forest demon. This paper emphasises that the myth of the supernatural ancestor bear gave rise to the custom of taking trained bears around Russian cities to rid them of evil spirits, as well as folk divination. The authors conclude that in the minds of these ancestors, the image of the bear went through several stages – from the idea of the bear as a tribal totem to the image of a benevolent spirit, a protector of people from evil spirits. The ancient pagan ideas about the bear as a deity remained part of the worldview of the East Slavic peoples until the early twentieth century, finding their reflection in folk fairytales, legends, and traditions.

The magnetic hyperfine-structure constants have been calculated for low-lying levels in a neutral gold atom and a goldlike ion of mercury taking into account the Bohr-Weisskopf (BW) effect. The BW effect is represented as a product of atomic and nuclear (${d}_{\mathrm{nuc}}$) factors. We have calculated the atomic factors, which enable one to extract BW-correction values for far from stability gold nuclei from the experimental data. The possible uncertainty of our atomic calculations have been estimated by the comparison with the available experimental data. It has been shown that the standard single-particle approach in ${d}_{\mathrm{nuc}}$ calculation reasonably well describes experimental data for $11/{2}^{\ensuremath{-}}$ gold isomers and the $3/{2}^{+}$ ground state of $^{199}\mathrm{Au}$. At the same time, it fails to describe the hyperfine constant in $^{197}\mathrm{Au}$. This indicates the more pronounced configuration mixing in $^{197}\mathrm{Au}$ than in $^{199}\mathrm{Au}$.

Particular advantages of chiral molecules for direct detection of the time-dependence of pseudoscalar and the timelike-component of pseudovector cosmic fields are highlighted. Such fields are invoked in different models for cold dark matter or in the Lorentz-invariance violating standard model extensions and thus are signatures of physics beyond the standard model. The sensitivity of a twenty year old experiment with the molecule CHBrClF to pseudovector cosmic fields as characterized by the parameter $|b^\mathrm{e}_0|$ is estimated to be $\mathcal{O}(10^{-12}\,\mathrm{GeV})$ and allows to predict the sensitivity of future experiments with favorable choices of chiral molecular probes to be $\mathcal{O}(10^{-17}\,\mathrm{GeV})$, which will be an improvement of the present best limits by at least two orders of magnitude., Comment: 6 pages, 2 figures

Recent experimental progress in cooling, trapping, and quantum logic spectroscopy of highly charged ions (HCIs) made HCIs accessible for high-resolution spectroscopy and precision fundamental studies. Based on these achievements, we explore a possibility to develop optical clocks using transitions between the ground and a low-lying excited state in ${\mathrm{Cf}}^{15+}$ and ${\mathrm{Cf}}^{17+}$ ions. Using a high-accuracy relativistic method of calculation, we predicted the wavelengths of clock transitions, calculated relevant atomic properties, and analyzed a number of systematic effects (such as the electric quadrupole, micromotion, and quadratic Zeeman shifts of the clock transitions) that affect the accuracy and stability of the optical clocks. We also calculated magnetic dipole hyperfine-structure constants of the clock states and the blackbody radiation shifts of the clock transitions.

Pseudoscalar or pseudovector cosmic fields, that serve as a source of parity ($\mathcal{P}$) violation, are invoked in different models for cold dark matter or in the standard model extension that allows for Lorentz invariance violation. A direct detection of the timelike-component of such fields requires a direct measurement of $\mathcal{P}$-odd potentials or their evolution over time. Herein, advantageous properties of chiral molecules, in which $\mathcal{P}$-odd potentials lead to resonance frequency differences between enantiomers, for direct detection of such $\mathcal{P}$-odd cosmic fields are demonstrated. Scaling behavior of electronic structure enhancements of such interactions with respect to nuclear charge number and the fine-structure constant is derived analytically. This allows a simple estimate of the effect sizes for arbitrary molecules. The analytical derivation is supported by quasi-relativistic numerical calculations in the molecules H$_2$X$_2$ and H$_2$XO with X $=$ O, S, Se, Te, Po. Parity violating effects due to cosmic fields on the C--F stretching mode in CHBrClF are compared to electroweak parity violation and influences of non-separable anharmonic vibrational corrections are discussed. On this basis it was estimated from a twenty year old experiment with CHBrClF that bounds on Lorentz invariance violation as characterized by the parameter $|b^\mathrm{e}_0|$ can be pushed down to the order of $10^{-17}\,\mathrm{GeV}$ in modern experiments with suitably selected molecular system, which will be an improvement of the current best limits by at least two orders of magnitude. This serves to highlight the particular opportunities that precision spectroscopy of chiral molecules provides in the search for new physics beyond the standard model., 16 pages, 6 tables, 5 figures

Hyperfine-structure constants for the 6s2S1/2 and 6p2P1/2 atomic states of the Iπ=11/2− gold isomers Aum177,191,193,195 have been measured at CERN-ISOLDE, using the in-source laser resonance-ionization spectroscopy technique. From the measured hyperfine constants the differences between hyperfine anomalies for these atomic states have been deduced. These differential hyperfine anomaly values have been used to determine the 6s-state hyperfine anomaly relative to the stable Au197 with advanced atomic calculations. Magnetic dipole moments for the gold isomers in question have been deduced, taking into account the corresponding relative hyperfine-anomaly values. It has been shown that the commonly used prescription for the extraction of the magnetic moment values for the gold isotopes should be reconsidered. The magnetic moments calculated by this prescription have been reevaluated by properly accounting for the hyperfine anomaly, which is as large as 10% for several gold isotopes.

One of the major components of magnetic resonance imaging safety for patients with an active implantable medical device is the evaluation of in vivo radio frequency induced heating of tissue near a lead electrode, which can result in tissue damage. This numerical case study investigated a number of the recommendations, assumptions, and requirements of Clause 8 of the technical specification ISO/TS10974. For this, a lead electromagnetic model (LEM) of a generic coax lead at 128 MHz was evaluated with 3-D electromagnetic and thermal cosimulations of the entire lead. Two sets of 120 incident electric fields with different profiles were generated in a homogenous medium using the electrical properties of blood by an array of four antennas. Substantial dependence of power deposition and temperature profiles around lead electrodes on the incident electric field did not reduce the quotient of the variances of the fitted LEM values, observed values of power deposition, and the net temperature increase, above background, with the presence of the generic coax lead. Our results indicate that the power injection approach based only on the comparison of the temperature increase in the medium along the lead tip electrode axis can result in substantial underestimation or overestimation of power deposition around lead electrodes.

Purpose The purpose of the paper was to help resolve the problem if only the universities possessing strategic entrepreneurship manage to advance significantly in their global ranking positions, while most of their competitors fail. Design/methodology/approach Conceptual part of the study introduces a new strategic entrepreneurial latecomer university framework, based on the combination of the resource-based view, dynamic capabilities, strategic innovation, strategic entrepreneurship and latecomer organization concepts. For verification of the proposed conceptual framework, case study of the Lausanne Federal Polytechnic Institute is considered by structuring the materials of its well-documented success story of its advancing in global rankings in terms of the construct dimensions. Findings The case study findings were identification of entrepreneurial mindset, managing human resources strategically and strategic innovativeness. It confirms conceptual findings that the presence of strategic entrepreneurship construct dimensions in latecomer university is instrumental in sensing business opportunities at most lucrative market segments of scientific research, carrying out its strategic innovation responsible for university difference in strategic transformational development and exploiting the opportunities ahead of its competitors so as to become more competitive and overtake them. Research limitations/implications The main limitations of this study are that only one case of university transition to catch-up development is explored and not all strategic entrepreneurship construct distinctive dimensions are considered. The research will be further elaborated to incorporate all strategic entrepreneurship construct dimensions. Practical implications The approach introduced here has shown that to advance in global rankings, university should carry out its strategic innovation ahead of its competitors. Originality/value The study is supposed to be the first where university at the stage of its transition to catch-up development is considered using new framework based on strategic entrepreneurship construct dimensions.

International audience; Many intrinsically disordered proteins (IDPs) and protein regions (IDRs) engage in transient, yet specific, interactions with a variety of protein partners. Often, if not always, interactions with a protein partner lead to partial folding of the IDR. Characterizing the conformational space of such complexes is challenging: in solution-­‐state NMR, signals of the IDR in the interacting region become broad, weak and often invisible; while X-­‐ray crystallography only provides information on fully ordered regions. There is thus a need for a simple method to characterize both fully and partially ordered regions in the bound state of IDPs. Here, we introduce an approach based on monitoring chemical ex-­‐ change by NMR to investigate the state of an IDR that folds upon binding through the observation of the free state of the protein. Structural constraints for the bound state are obtained from chemical shifts and site-­‐specific dynamics of the bound state are characterized by relaxation rates. The conformation of the interacting part of the IDR was determined and subsequently docked onto the structure of the folded partner. We apply the method to investigate the interaction between the disordered C-­‐terminal region of Artemis and the DNA binding domain of Ligase IV. We show that we can accurately reproduce the structure of the core of the complex determined by X-­‐ray crystallography and identify a broader interface. The method is widely applicable to the biophysical investigation of complexes of disordered proteins and folded proteins.

The lead electromagnetic model (LEM) and the radiofrequency responses, i.e., the net dissipated electrode power and net temperature increase, above background, at the electrodes, were modelled for two coax-type insulated leads with inner and outer helical wires with a pitch of 0.35 mm. The quotient of the variances of the fitted LEM values and observed values (R2) of the radiofrequency responses was substantially different for the lead electrode versus the ring electrode, where R2 of the ring quotient was a function of the duration of the RF-induced heating.