Magnetic field dependence of the neutron spin resonance in CeB6

In zero magnetic field, the famous neutron spin resonance in the f-electron superconductor CeCoIn5 is similar to the recently discovered exciton peak in the non-superconducting CeB6. Magnetic field splits the resonance in CeCoIn5 into two components, indicating that it is a doublet. Here we employ inelastic neutron scattering (INS) to scrutinize the field dependence of spin fluctuations in CeB6. The exciton shows a markedly different behavior without any field splitting. Instead, we observe a second field-induced magnon whose energy increases with field. At the ferromagnetic zone center, however, we find only a single mode with a non-monotonic field dependence. At low fields, it is initially suppressed to zero together with the antiferromagnetic order parameter, but then reappears at higher fields inside the hidden-order phase, following the energy of an electron spin resonance (ESR). This is a unique example of a ferromagnetic resonance in a heavy-fermion metal seen by both ESR and INS consistently over a broad range of magnetic fields.Comment: 7 pages, 6 figures including one animation, accepted to Phys. Rev.

Magnon spectrum of the helimagnetic insulator Cu2OSeO3

Complex low-temperature-ordered states in chiral magnets are typically governed by a competition between multiple magnetic interactions. The chiral-lattice multiferroic Cu2OSeO3 became the first insulating helimagnetic material in which a long-range order of topologically stable spin vortices known as skyrmions was established. Here we employ state-of-the-art inelastic neutron scattering to comprehend the full three-dimensional spin-excitation spectrum of Cu2OSeO3 over a broad range of energies. Distinct types of high- and low-energy dispersive magnon modes separated by an extensive energy gap are observed in excellent agreement with the previously suggested microscopic theory based on a model of entangled Cu4 tetrahedra. The comparison of our neutron spectroscopy data with model spin-dynamical calculations based on these theoretical proposals enables an accurate quantitative verification of the fundamental magnetic interactions in Cu2OSeO3 that are essential for understanding its abundant low-temperature magnetically ordered phases

Superconducting properties and pseudogap from preformed Cooper pairs in the triclinic (CaFe1−x_{1-x}Ptx_xAs)10_{10}Pt3_3As8_8

Using a combination of muon-spin relaxation ($\mu$SR), inelastic neutron scattering (INS) and nuclear magnetic resonance (NMR), we investigated the novel iron-based superconductor with a triclinic crystal structure (CaFe$_{1-x}$Pt$_x$As)$_{10}$Pt$_3$As$_8$ (T$_{\rm c}$ = 13 K), containing platinum-arsenide intermediary layers. The temperature dependence of the superfluid density obtained from the $\mu$SR relaxation-rate measurements indicates the presence of two superconducting gaps, $\Delta_\text{1}\gg\Delta_\text{2}$. According to our INS measurements, commensurate spin fluctuations are centered at the ($\pi$, 0) wave vector, like in most other iron arsenides. Their intensity remains unchanged across T$_\text{c}$, indicating the absence of a spin resonance typical for many Fe-based superconductors. Instead, we observed a peak in the spin-excitation spectrum around $\hslash\omega_0=\,$7 meV at the same wave vector, which persists above T$_{\rm c}$ and is characterized by the ratio $\hslash\omega_0/k_\text{B}T_\text{c}\approx\,$6.2, which is significantly higher than typical values for the magnetic resonant modes in iron pnictides (~4.3). The temperature dependence of magnetic intensity at 7 meV revealed an anomaly around T* = 45 K related to the disappearance of this new mode. A suppression of the spin-lattice relaxation rate, $1/T_1T$, observed by NMR immediately below T* without any notable subsequent anomaly at T$_{\rm c}$, indicates that T* could mark the onset of a pseudogap in (CaFe$_{1-x}$Pt$_x$As)$_{10}$Pt$_3$As$_8$, which is likely associated with the emergence of preformed Cooper pairs

Роль ультразвуковой оценки коэффициента массы селезенки в динамике наблюдения детей с хронической формой ВЭБ-инфекцией

Purpose of the study: to show the significance of ultrasound diagnostics in assessing the dynamics of the spleen mass coefficient in children of various age against the background of a chronic form of EBV virus.Materials and methods. The study was performed on 146 children aged 3 to 18 years suffering from chronic EBV virus. Depending on age, the children were divided into 3 groups. Group 1 included 63 patients aged 3 to 7 years; Group 2 consisted of 28 children aged 8 to 11 years; Group 3 included 55 children aged 12 to 18 years. The clinical, laboratory and ultrasound examination was conducted including ultrasound of the spleen with the further determination of its mass coefficient (SMC).Results. In the acute period of EBV virus, children of all age groups revealed an increase in SMC, while the maximum increase was observed in children aged 3 to 7 years and amounted to 6,88. Against the background of a complete clinical and laboratory recovery in this age group, the SMC remained at the level of 4.66 and did not reach the average values of healthy children of the same age. The follow-up dynamics for 15–18 months demonstrated the normalization of the SMC to the average values of healthy patients in accordance with their age (in children aged 12 years and older).Findings. Children in the age group from 3 to 7 years old had the maximum value of the spleen mass coefficient, both in the acute period and after complete clinical and laboratory recovery. The use of ultrasound technique with the assessment of the spleen mass coefficient in the chronic course of EBV virus allows expanding and determining the children contingent for further dynamic monitoring for prevention of possible complications.Цель исследования: показать значимость ультразвуковой диагностики  в оценке динамики коэффициента массы селезенки у детей различных возрастных групп на фоне хронической формы ВЭБ - инфекции.Материалы и методы. В исследование включили 146 детей в возрасте от 3 до 18 лет с хронической формой ВЭБ - инфекции. В зависимости от возраста, дети были разделены на 3 группы. В 1-ю группу вошло 63 пациента от 3 до 7 лет; 2 – ю группу составили 28 детей с 8 до 11 лет; 3 – ю группу - 55 детей от 12 до 18 лет. Проводили клиническое, лабораторное и ультразвуковое обследование, включая ультразвуковое исследование селезенки с определением коэффициента массы (КМС).Результаты. В остром периоде ВЭБ инфекции дети всех возрастных групп имели увеличение КМС, при этом максимальное увеличение отмечалось у детей от 3 до 7 лет и колебалось в диапазоне от 4,9 до 9,2. При наличии полного клинико-лабораторного выздоровления у данного возрастного контингента КМС оставался на уровне 4,2-5,8 и не достигал средних значений здоровых детей данного возраста. Динамика наблюдения в течение 15-18 месяцев выявляла нормализацию КМС до средневозрасных значений здоровых пациентов у детей 12 лет и старше.Выводы. Дети в группе от 3 до 7 лет имели максимальное значение коэффициента массы селезенки, как в остром периоде, так и после полного клинико - лабораторного выздоровления. Применение ультразвуковой методики с оценкой коэффициента массы селезенки при хроническом течении ВЭБ-инфекции позволяет расширить и определить контингент детей для дальнейшего динамического наблюдения с целью профилактики возможных осложнений

Way of life and health of Grodno University students

students, health, way of life, risk factors, preventive measuresIntroduction. Preservation and strengthening of youth's health is one of the state priorities in the Republic of Belarus. Aim. To reveal peculiarities of students' way of life and health factors. Material & method. The survey answers of 350 students of Grodno State Medical University and Yanka Kupala Grodno State University questionnaire were analyzed. The students were surveyed in May-October of 2009 under the program of a sociological research «Health of students» organized in different regions of Belarus and Russia (the head was professor I.V. Zhuravlyova). Self-estimations of health and the attitude to it, factors of nutrition, physical activity, emotional background, behavior in relation to psychoactive substances, sexual behavior, behavior of students in relation to medical aid, preventive measures, the relation to health services were studied. Results. Only 34.9% of the students estimated their own health as «good». The majority (54.4%) of students considered their health as «satisfactory». More than a half of the students considered good health as a priority to achieve success in life. Simultaneously, according to the students' opinion, their own efforts were the most significant for their health status. The majority (87%) of the students considered that they took care of their health. In every fifth case self-health care was caused by its deterioration. Despite the positive relation to health, high prevalence of risk factors in relation to nutrition was revealed; 22.8% of the students smoked. The problem of the frequent use of beer was especially manifested: 17.1 % of young women and 47.9 % of young men answered that they used beer often. About 7.1% of the students tried drugs; 18.6% had acquaintances that used drugs. Only 9.5% were engaged daily in physical activity. Despite a high need for health-related information, low medical activity and insufficient knowledge about public health services system as a whole was revealed among the students. The expressed gender distinctions on a number of factors were significant. Conclusion. The study results allowed to allocate directions of preventive measures for the formation of health-oriented behaviors in students of Grodno universities

LESHEK PARADOVSKY, KAZIMIERZ NIKOLAI IMELINSKY, ZBIGNIEW PUHALSKY, RICHARD JERZY GRIGLEVSKY, LEON DROBNIK AND SLAVOY KUKHARSKY – - DOCTORS HONORIS CAUSA OF THE GRODNO STATE MEDICAL UNIVERSITY AND PROMINENT FIGURES IN SCIENCE, HIGHER EDUCATION AND MEDICINE OF POLAND

The article presents the features of biography, creative growth, some historical facts of life, professional activities and cooperation with the Grodno State Medical University of outstanding representatives of science and education of Poland and Honorary Doctors of the Grodno State Medical University, experts with a world-wide name: professors Leshek Paradovsky, Kazimierz Nikolai Imelinsky, Zbigniew Puhalsky, Richard Jerzy Griglevsky, Leon Drobnik and Slavoy Kukharsky. The period of their active professional activities coincided with the time when the Grodno State Medical Institute was transformed into a University. To restore and clarify the autobiographical data, one of the authors of the article – Professor Yaroslav Baransky – talked with the Honorary Doctors themselves, with their colleagues, and their relatives