Temperature-dependent quantum electron transport in 2D point contact

We consider a transmission of electrons through a two-dimensional ballistic point contact in the low-conductance regime below the 0.7-anomaly. The scattering of electrons by Friedel oscillations of charge density results in a contribution to the conductance proportional to the temperature. The sign of this linear term depends on the range of the electron-electron interaction and appears to be negative for the relevant experimental parameters.Comment: 10 pages, 5 figure

Electrostatic and electrokinetic contributions to the elastic moduli of a driven membrane

We discuss the electrostatic contribution to the elastic moduli of a cell or artificial membrane placed in an electrolyte and driven by a DC electric field. The field drives ion currents across the membrane, through specific channels, pumps or natural pores. In steady state, charges accumulate in the Debye layers close to the membrane, modifying the membrane elastic moduli. We first study a model of a membrane of zero thickness, later generalizing this treatment to allow for a finite thickness and finite dielectric constant. Our results clarify and extend the results presented in [D. Lacoste, M. Cosentino Lagomarsino, and J. F. Joanny, Europhys. Lett., {\bf 77}, 18006 (2007)], by providing a physical explanation for a destabilizing term proportional to \kps^3 in the fluctuation spectrum, which we relate to a nonlinear ($E^2$) electro-kinetic effect called induced-charge electro-osmosis (ICEO). Recent studies of ICEO have focused on electrodes and polarizable particles, where an applied bulk field is perturbed by capacitive charging of the double layer and drives flow along the field axis toward surface protrusions; in contrast, we predict "reverse" ICEO flows around driven membranes, due to curvature-induced tangential fields within a non-equilibrium double layer, which hydrodynamically enhance protrusions. We also consider the effect of incorporating the dynamics of a spatially dependent concentration field for the ion channels.Comment: 22 pages, 10 figures. Under review for EPJ

Analysis of the restoration of cardiology diagnostics scope in the Russian Federation during the COVID-19 pandemic: results of the Russian segment of the INCAPS COVID 2 study under the auspices of the International Atomic Energy Agency

Aim. To assess the changes in cardiology diagnostics scope in the Russian Federation during the coronavirus disease 2019 (COVID-19) pandemic.Material and methods. In an online survey organized by the Division of Human Health of the International Atomic Energy Agency (IAEA), including questions about changes in the workflow of diagnostic laboratories and the scope of cardiac diagnostics from March 2019 (pre-pandemic) to April 2020 (first wave of the pandemic) and April 2021 (recovery stage), 15 Russian medical centers from 5 cities took part.Results. The decrease in the diagnostics scope by April 2020 by 59,3% compared to March 2019, by April 2021, stopped and was replaced by growth (+7,1%, the recovery rate, 112,1%). The greatest increase was in routine examinations, such as echocardiography (+11,6%), stress echocardiography (+18,7%), stress single photon emission computed tomography (+9,7%), and to a lesser extent resting computed tomography angiography (+7,0%) and magnetic resonance imaging (+6,6%). The performance of stress electrocardiography, stress magnetic resonance imaging and positron emission tomography for the diagnosis of endocarditis in April 2021 compared to March 2019 decreased by 10,3%, 63,2% and 62,5%, respectively.Conclusion. Due to the resumption of patient admissions for cardiac examinations during the ongoing COVID-19 pandemic, with the anti-epidemic measures taken and certain changes in the workflow, there has been a recovery in the diagnostics scope in most of the included centers

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Phylogenetic relationships between Lubomirskiidae, Spongillidae and some marine sponges according to partial sequences of 18S rDNA

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Endemic Lake Baikal sponges from deep water. 2: Taxonomy and Bathymetric Distribution

Itskovich, Valeria B., Kaluzhnaya, Oxana V., Veynberg, Elena, Erpenbeck, Dirk (2017): Endemic Lake Baikal sponges from deep water. 2: Taxonomy and Bathymetric Distribution. Zootaxa 4236 (2): 335-342, DOI: https://doi.org/10.11646/zootaxa.4236.2.

Impact of the first wave of coronavirus disease 2019 (COVID-19) pandemic on the diagnosis of heart disease in the Russian Federation: results from the Russian segment of the IAEA INCAPS COVID study

Aim. To assess the impact of the first wave of coronavirus disease 2019 (COVID-19) pandemic on the diagnosis of heart disease in the Russian Federation. Material and methods. Fifteen Russian medical centers from 5 cities took part in an online survey organized by the Division of Human Health of the International Atomic Energy Agency (IAEA), containing questions regarding alterations in cardiovascular procedure volumes resulting from COVID-19 in March-April 2020. Results. A number of outpatients undergoing cardiac diagnostic procedures was noted in 80% of clinics. Cardiovascular procedure volumes in the period from March 2019 to March 2020 in general decreased by 9,5%, and from March 2019 to April 2020, by 56,5%. Stress electrocardiography decreased by 38,4%, stress echocardiography by 72,5%, stress single-photon emission computed tomography by 66,9%, computed tomography angiography by 49,7%, magnetic resonance imaging by 42,7%, invasive coronary angiography by 40,7%. The decrease in diagnostic procedure volumes in selected regions (Tomsk Oblast, Kemerovo Oblast, Tatarstan) was not so pronounced compared to Moscow and St. Petersburg (-20,7%,-75,2%,-93,8% in April 2020, respectively, p&lt;0,001). Conclusion. The first wave of the COVID-19 pandemic caused a sharp decrease in the number of diagnostic cardiac procedures in Russia. This has potential long-term implications for patients with cardiovascular disease. Understanding these implications can help guide diagnostic strategies during the ongoing COVID-19 pandemic and minimize the future losses