Synthesis of silymarin−selenium nanoparticle conjugate and examination of its biological activity in vitro

Silymarin (Sil) was conjugated to selenium nanoparticles (SeNPs) to increase Sil bioavailability. The conjugates were monodisperse; the average diameter of the native SeNPs was ~ 20-50 ± 1.5 nm, whereas that of the conjugates was 30-50 ± 0.5 nm. The use of SeNPs to increase the bioavailability of Sil was examined with the MH-22a, EPNT-5, HeLa, Hep-2, and SPEV-2 cell lines. The EPNT-5 (glioblastoma) cells were the most sensitive to the conjugates compared to the conjugate-free control. The conjugates increased the activity of cellular dehydrogenases and promoted the penetration of Sil into the intracellular space. Possibly, SeNPs play the main part in Sil penetration of cells and Sil penetration is not associated with phagocytosis. Thus, SeNPs are promising for use as a Sil carrier and as protective antigens

Fundamental dissipation due to bound fermions in the zero-temperature limit

The ground state of a fermionic condensate is well protected against perturbations in the presence of an isotropic gap. Regions of gap suppression, surfaces and vortex cores which host Andreev-bound states, seemingly lift that strict protection. Here we show that in superfluid 3He the role of bound states is more subtle: when a macroscopic object moves in the superfluid at velocities exceeding the Landau critical velocity, little to no bulk pair breaking takes place, while the damping observed originates from the bound states covering the moving object. We identify two separate timescales that govern the bound state dynamics, one of them much longer than theoretically anticipated, and show that the bound states do not interact with bulk excitations

Effect of the boundary condition on the Kapitza resistance between superfluid 3He-B and sintered metal

Understanding the temperature dependence of thermal boundary resistance, or Kapitza resistance, between liquid helium and sintered metal has posed a problem in low temperature physics for decades. In the ballistic regime of superfluid 3He-B, we find the Kapitza resistance can be described via scattering of thermal excitations (quasiparticles) with a macroscopic geometric area, rather than the sintered metal's microscopic area. We estimate that a quasiparticle needs on the order of 1000 collisions to successfully thermalize with the sinter. Finally, we find that the Kapitza resistance is approximately doubled with the addition of two mono-layers of solid 4He on the sinter surface, which we attribute to an extra magnetic channel of heat transfer being closed as the non-magnetic solid 4He replaces the magnetic solid 3He

Transport of bound quasiparticle states in a two-dimensional boundary superfluid

The B phase of superfluid 3He can be cooled into the pure superfluid regime, where the thermal quasiparticle density is negligible. The bulk superfluid is surrounded by a quantum well at the boundaries of the container, confining a sea of quasiparticles with energies below that of those in the bulk. We can create a non-equilibrium distribution of these states within the quantum well and observe the dynamics of their motion indirectly. Here we show that the induced quasiparticle currents flow diffusively in the two-dimensional system. Combining this with a direct measurement of energy conservation, we conclude that the bulk superfluid 3He is effectively surrounded by an independent two-dimensional superfluid, which is isolated from the bulk superfluid but which readily interacts with mechanical probes. Our work shows that this two-dimensional quantum condensate and the dynamics of the surface bound states are experimentally accessible, opening the possibility of engineering two-dimensional quantum condensates of arbitrary topology

Problems of personnel irradiation in modern medical technologies

BACKGROUND: The widespread use of radiation sources in medical practice (cardio-endovascular surgery, endoscopy, traumatology, urology, neurosurgery, dentistry, and radioisotope diagnostics departments) leads to irradiation of the lens of the eye and the skin of the hands. The introduction of new recommendations by the IAEA to reduce the limit of the annual equivalent dose to the lens (20 mSv) has led to an inaccurate dose assessment based on the effective dose. AIM: To analyze approaches and assess equivalent doses of irradiation of the lens of the eye and skin of the hands of medical personnel during various diagnostic studies under the influence of X-rays and radiopharmaceuticals studies and to compare the results obtained with previously published data. MATERIALS AND METHODS: Thermo-luminescent dosimetry was used. Dose assessment was performed by cardio-endovascular surgery, endoscopy, isotope diagnostics, dentistry, and urology personnel. RESULTS: The estimated annual equivalent doses to the lens of the eye for doctors of cardio-endovascular surgery departments, in most cases, ranging 3590 mSv, 619 mSv for the average medical staff (in some cases, the doctor [225 mSv] and the nurse [180 mSv]) and 4.59 mSv for the staff of the department of radioisotope diagnostics. The annual calculated equivalent doses to the skin of the hands for cardio-endovascular surgery personnel were 17100 and 24220 mSv for the staff working with radiopharmaceuticals. It is shown that the use of an estimate of the average dose per operation by cardio-endovascular surgery doctors, as a rule, inevitably leads to an excess of the equivalent dose to the lens of the eye after a certain number of operations. CONCLUSION: When a certain number of operations are exceeded (100200), equivalent doses to the eyes lens in cardio-endovascular surgery doctors above 20 mSv per year can be formed. At current radiation levels, a lesion of the eyes lens was found in a cardio-endovascular surgery doctor. The results indicate the need for further dosimetric measurements and epidemiological studies, based on which recommendations for radiation protection of the eyes lens and the skin of the hands of medical personnel working in low-intensity, scattered, gamma X-ray radiation can be developed

Вопросник для первичной самооценки здоровья пациентов, перенесших новую коронавирусную инфекцию: Рекомендации Междисциплинарного совета экспертов по проведению скрининга симптомов постковидного периода при углубленной диспансеризации

The post-COVID symptom complex is wide enough and requires special vigilance during clinical examination of patients after the novel coronavirus infection. The aim of the Multidisciplinary Expert Board study was to develop a standardized questionnaire for initial self-assessment by patients who had had COVID-19 before the expanded medical check-up.Methods. The existing validated international and national questionnaires and scales were analyzed to assess their relevance, convenience, and ease of filling out. Results of the analysis were used to set up a screening for post-COVID symptoms.Results. The work of the Multidisciplinary Expert Board in June-August 2021 resulted in a new screening questionnaire for the initial assessment of the health status of patients who have COVID-19. The questionnaire is intended for self-filling before the further clinical examination.Conclusion. A new standardized patient questionnaire to screen for post-COVID symptoms may significantly optimize the doctor’s working time, increase the efficiency of diagnosis, improve the principles of selection and formation of risk groups of patients during an expanded medical check-up.Симптомокомплекс нарушений постковидного периода достаточно широк и требует специальной настороженности врача при проведении диспансеризации пациентов, перенесших новую коронавирусную инфекцию.Целью работы Междисциплинарного Совета экспертов явилась разработка унифицированного вопросника для самостоятельного заполнения пациентом при подготовке к углубленной диспансеризации после перенесенного COVID-19.Материалы и методы. Проведен анализ существующих международных и отечественных анкет и шкал с целью оценки их релевантности, удобства и простоты заполнения для возможного скрининга расстройств постковидного периода. Результаты. Итогом работы Междисциплинарного Совета Экспертов в июне-августе 2021 г. явилось создание нового скрининг-вопросника по первичной оценке состояния здоровья пациентов, перенесших COVID-19, предназначенного для самостоятельного заполнения ими при подготовке к углубленной диспансеризации.Заключение. Создание унифицированного вопросника пациента при скрининге постковидных нарушений позволит существенно оптимизировать рабочее время врача, повысить эффективность диагностики заболеваний, совершенствовать принципы отбора и формирования групп риска пациентов при углубленной диспансеризации

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements