Esophageal Hemorrhagic Syndromes

Esophageal  bleeding is  one of  the most  common medical emergencies. It takes  the  3rd place among  all digestive hemorrhages, and accounts for 14–16 % among all gastrointestinal bleeding. The most common cause of esophageal hemorrhages is Mallory – Weiss esophageal tear (10–12 %), less often – varicose veins of the esophagus in portal hypertension syndrome (up to 4 %) and, in some cases, is esophagitis of various etiologies (up to 1.6 %). The problem of  esophageal  bleeding  is  characterized  by  high  incidence,  high  mortality  rate  due  to  constant  increase  of  portal hyper tension cases, recurrences, difficulties in diagnosis, anatomical and physiological features of the esophagus, low efficiency of the main methods of hemostasis. There are various surgical and conservative methods of hemostasis, which show a variety of opinions in the solution to the problem of stopping esophageal bleeding. In Mallory – Weiss syndrome, endoscopic hemostasis is considered to be the preferred method of treatment. Management of portal hypertension is the most difficult task; a wide range of operations is used from the minimally invasive operations to the liver transplantation, as well as endoscopic hemostasis (ligation, sclerotherapy). In esophageal bleeding, due to reflux esophagitis, mainly conservative treatment is suggested, operations are performed with recurrences or complications. Each kind of esophageal hemorrhage is considered as a separate problem

O1 Serogroup Cholera Vibrios Isolated from the Rostov-on-Don Water Bodies in the Course of Surveillance in 2008–2012

Identified are the peculiarities of biological properties and origin of cholera vibrio O1 serogroup strains isolated from the Rostov-on-Don water bodies in the course of surveillance in 2008–2012. 41 atoxigenic V. cholerae O1 strains have been isolated from 767 water samples and investigated. Stable tendency of isolation of increased numbers of atoxigenic V. cholerae O1 strains over time has been demonstrated. In addition, in the strains under study detected have been the genes of additional pathogenicity factors, by PCR genotyping using specific primers for 45 nucleotide sequences associated with V. cholerae pathogenicity. The strains have also been classified according to 19 VNTR-genotypes grouped into 6 clusters based on VNTR-typing using exclusive copyright locus-specific primers. Discovered have been the strains with similar genotypes though isolated at different points both throughout the year and over the period of several years. These ones have probably been imported. They are characterized by a capacity to persist in ambient water bodies for a certain period of time

Cholera Forecast for the Year 2019 Based on Assessment of Epidemiological Situation Around the World, Across CIS and Russia in 2009–2018

Analysis of cholera incidence for the period of 2009–2018 was performed. The upward tendency in the morbidity rate dynamics around the world (compared to 2009) with an average annual growth rate of 5,352 % was revealed. For the first time during the 7th pandemic caused by V. cholerae O1 El Tor, WHO reported 1227391 cases of cholera world-wide in 2017, out of which 1032481 (84.1%) were registered in Yemen, where the war continues and one of the largest epidemics in the world. There have been cross-border epidemiological complications in several African countries. Endemic foci continue to exist and spread in Asia, Africa and the Caribbean. Under the epidemiological surveillance in Russia, 744 strains of V. cholerae El Tor – ctxA– tcpA–, ctxA– tcpA+ and V. cholerae О139 ctxA– and tcpA– were isolated from the surface water bodies, as well as single strains of El Tor ctxA+ tcpA+. As a result of INDEL- and  PCR-genotyping, the isolation of strains with identical genotypes and new ones was established. To make the prognosis for 2019, the risk of activation (continuation) of the cholera epidemic process in the world was assessed, taking into account emergencies of different origin and risk factors. The cholera forecast at the global level and in  Russia for 2019 is unfavorable

Recent advances on thermoelectric materials

By converting waste heat into electricity through the thermoelectric power of solids without producing greenhouse gas emissions, thermoelectric generators could be an important part of the solution to today's energy challenge. There has been a resurgence in the search for new materials for advanced thermoelectric energy conversion applications. In this paper, we will review recent efforts on improving thermoelectric efficiency. Particularly, several novel proof-of-principle approaches such as phonon disorder in phonon-glasselectron crystals, low dimensionality in nanostructured materials and charge-spin-orbital degeneracy in strongly correlated systems on thermoelectric performance will be discussed.Comment: 12 pages, 12 figure

Study on cosmogenic activation above ground for the DarkSide-20k project

The activation of materials due to the exposure to cosmic rays may become an important background source for experiments investigating rare event phenomena. DarkSide-20k is a direct detection experiment for galactic dark matter particles, using a two-phase liquid argon time projection chamber filled with 49.7 tonnes (active mass) of Underground Argon (UAr) depleted in 39Ar. Here, the cosmogenic activity of relevant long-lived radioisotopes induced in the argon and other massive components of the set-up has been estimated; production of 120 t of radiopure UAr is foreseen. The expected exposure above ground and production rates, either measured or calculated, have been considered. From the simulated counting rates in the detector due to cosmogenic isotopes, it is concluded that activation in copper and stainless steel is not problematic. Activation of titanium, considered in early designs but not used in the final design, is discussed. The activity of 39Ar induced during extraction, purification and transport on surface, in baseline conditions, is evaluated to be 2.8% of the activity measured in UAr from the same source, and thus considered acceptable. Other products in the UAr such as 37Ar and 3H are shown to not be relevant due to short half-life and assumed purification methods

Measurement of isotopic separation of argon with the prototype of the cryogenic distillation plant Aria for dark matter searches

The Aria cryogenic distillation plant, located in Sardinia, Italy, is a key component of the DarkSide-20k experimental program for WIMP dark matter searches at the INFN Laboratori Nazionali del Gran Sasso, Italy. Aria is designed to purify the argon, extracted from underground wells in Colorado, USA, and used as the DarkSide-20k target material, to detector-grade quality. In this paper, we report the first measurement of argon isotopic separation by distillation with the 26 m tall Aria prototype. We discuss the measurement of the operating parameters of the column and the observation of the simultaneous separation of the three stable argon isotopes: 36Ar , 38Ar , and 40Ar . We also provide a detailed comparison of the experimental results with commercial process simulation software. This measurement of isotopic separation of argon is a significant achievement for the project, building on the success of the initial demonstration of isotopic separation of nitrogen using the same equipment in 2019

Directionality of nuclear recoils in a liquid argon time projection chamber

The direct search for dark matter in the form of weakly interacting massive particles (WIMP) is performed by detecting nuclear recoils (NR) produced in a target material from the WIMP elastic scattering. A promising experimental strategy for direct dark matter search employs argon dual-phase time projection chambers (TPC). One of the advantages of the TPC is the capability to detect both the scintillation and charge signals produced by NRs. Furthermore, the existence of a drift electric field in the TPC breaks the rotational symmetry: the angle between the drift field and the momentum of the recoiling nucleus can potentially affect the charge recombination probability in liquid argon and then the relative balance between the two signal channels. This fact could make the detector sensitive to the directionality of the WIMP-induced signal, enabling unmistakable annual and daily modulation signatures for future searches aiming for discovery. The Recoil Directionality (ReD) experiment was designed to probe for such directional sensitivity. The TPC of ReD was irradiated with neutrons at the INFN Laboratori Nazionali del Sud, and data were taken with 72 keV NRs of known recoil directions. The direction-dependent liquid argon charge recombination model by Cataudella et al. was adopted and a likelihood statistical analysis was performed, which gave no indications of significant dependence of the detector response to the recoil direction. The aspect ratio R of the initial ionization cloud is estimated to be 1.037 +/- 0.027 and the upper limit is R < 1.072 with 90% confidence levelComment: 20 pages, 10 figures, submitted to Eur. Phys. J.

Sensitivity projections for a dual-phase argon TPC optimized for light dark matter searches through the ionization channel

Dark matter lighter than 10 GeV/c$^2$ encompasses a promising range of candidates. A conceptual design for a new detector, DarkSide-LowMass, is presented, based on the DarkSide-50 detector and progress toward DarkSide-20k, optimized for a low-threshold electron-counting measurement. Sensitivity to light dark matter is explored for various potential energy thresholds and background rates. These studies show that DarkSide-LowMass can achieve sensitivity to light dark matter down to the solar neutrino floor for GeV-scale masses and significant sensitivity down to 10 MeV/c$^2$ considering the Migdal effect or interactions with electrons. Requirements for optimizing the detector's sensitivity are explored, as are potential sensitivity gains from modeling and mitigating spurious electron backgrounds that may dominate the signal at the lowest energies

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe