Can Barrier to Relative Sliding of Carbon Nanotube Walls Be Measured?

Interwall interaction energies, as well as barriers to relative sliding of the walls along the nanotube axis, are first calculated for pairs of both armchair or both zigzag adjacent walls of carbon nanotubes with a wide range of radiuses. It is found that for the pairs with the radius of the outer wall greater than 5 nm both the interwall interaction energy and barriers to the relative sliding per one atom of the outer wall only slightly depends on the wall radius. A wide set of the measurable physical quantities determined by these barriers are estimated as a function of the wall radius: shear strengths and diffusion coefficients for relative sliding of the walls along the axis, as well as frequencies of relative axial oscillations of the walls. For nonreversible telescopic extension of the walls, maximum overlap of the walls for which threshold static friction forces are greater than capillary forces is estimated. Possibility of experimental verification of the calculated barriers by measurements of the estimated physical quantities is discussed.Comment: 16 pages, 8 figure

Current discourse on recurrent pregnancy loss (ESHRE Protocol 2023, National Clinical Guidelines "Recurrent Pregnancy Loss" 2021, materials of the World Congress of ESHRE 2023)

Yu.E. Dobrokhotova, P.A. Kuznetsov, L.S. Dzhokhadze Pirogov Russian National Research Medical University, Moscow, Russian Federation In January 2023, European Society of Human Reproduction and Embryology (ESHRE) has released updated recommendations on recurrent pregnancy loss to replace the previous 2017 version. All changes and addendum to the recommendations in the guidelines were formulated after evaluating the most qualitative and relevant evidence that appeared in the literature and their discussion by an expert group. The authors of this article have analyzed the main points of the updated ESHRE recommendations. The article discusses whether new tactics have appeared in the patient management with recurrent pregnancy loss, whether they should be adopted by a practicing physician, and whether they differ from the recommendations of the Russian Society of Obstetricians and Gynecologists regulating the actions of Russian medical specialists during the work with female patients having the appropriate diagnosis. Based on the analysis, the authors concluded that the expert groups that compiled clinical recommendations on recurrent pregnancy loss are mostly in solidarity on fundamental issues. On the one hand, the Russian recommendations look more reasonable in some issues, but on the other, the recommendations are likely to be revised taking into account new data. Keywords: recurrent pregnancy loss, habitual abortion, pregnancy, ESHRE, clinical recommendations, RSOG, assisted reproductive technologies. For citation: Dobrokhotova Yu.E., Kuznetsov P.A., Dzhokhadze L.S. Current discourse on recurrent pregnancy loss (ESHRE Protocol 2023, National Clinical Guidelines "Recurrent Pregnancy Loss" 2021, materials of the World Congress of ESHRE 2023). Russian Journal of Woman and Child Health. 2023;6(3):2019–225 (in Russ.). DOI: 10.32364/2618-8430-2023-6-3-1. </p

Peculiarities in fragment mass distribution in the 238U\bf{^{238}U} + 40Ar\bf{^{40}Ar} (243 MeV) reaction

A pronounced fine structure (FS) in the form of distinct peaks was observed in neutron gated mass spectra from the decay of the $^{278}$110 composite system produced in the reaction $\mathsf{^{238}U}$ + $\mathsf{^{40}Ar}$ (243 MeV) at an initial excitation energy $E^*> 70$ MeV. The FS peaks are located in the vicinity of mass numbers 70-80, 100, and 130, which correspond to those of magic nuclei (clusters). In the data there is also evidence for a new type of decay -collinear cluster tripartition of an excited nucleus