Development of low-temperature thermochemical conversion reactors for coal power engineering

The main principles applied in developing a technology for low-temperature thermochemical conversion of brown coals to obtain fuel gas and semicoke intended for being fired in two-fuel power installations are considered on the basis of a set of experimental and calculated investigations. The obtained results are compared with the experimental data obtained using other methods and with the results of previous industrial tests. © 2013 Pleiades Publishing, Inc

Low-temperature barrier discharge plasma modification of scaffolds based on polylactic acid

We have explored the effect of low-temperature barrier discharge plasma treatment in oxygen, nitrogen, and argon on modification of the physicochemical properties of polylactic acid (PLA)-based scaffolds. The cellular-mediated immune response to the interaction of macrophages of three donors with the modified surface of PLA-based scaffolds was also nvestigated. Carbonization of the PLA surface accompanied by a carbon atomic concentration increase is shown to occur following plasma treatment. Argon plasma significantly affects the wettability characteristics of PLA; the hydrophilicity and lipophilicity are improved, and the surface energy is increased. The viability of cells in the presence of plasma-modified PLA scaffolds is lower than that for unmodified PLA but remains greater than that for the negative control. We find that PLA scaffolds do not cause increased expression of the proinflammatory (TNFα, IL-6, IL-1β) cytokines after 6 days of cell cultivation. At the same time, PLA scaffolds do not affect the increased production of anti-inflammatory cytokines (IL-10)

Directional Sensitivity of the NEWSdm Experiment to Cosmic Ray Boosted Dark Matter

We present a study of a directional search for Dark Matter boosted forward when scattered by cosmic-ray nuclei, using a module of the NEWSdm experiment. The boosted Dark Matter flux at the edge of the Earth's atmosphere is expected to be pointing to the Galactic Center, with a flux 15 to 20 times larger than in the transverse direction. The module of the NEWSdm experiment consists of a 10 kg stack of Nano Imaging Trackers, i.e.~newly developed nuclear emulsions with AgBr crystal sizes down to a few tens of nanometers. The module is installed on an equatorial telescope. The relatively long recoil tracks induced by boosted Dark Matter, combined with the nanometric granularity of the emulsion, result in an extremely low background. This makes an installation at the INFN Gran Sasso laboratory, both on the surface and underground, viable. A comparison between the two locations is made. The angular distribution of nuclear recoils induced by boosted Dark Matter in the emulsion films at the surface laboratory is expected to show an excess with a factor of 3.5 in the direction of the Galactic Center. This excess allows for a Dark Matter search with directional sensitivity. The surface laboratory configuration prevents the deterioration of the signal in the rock overburden and it emerges as the most powerful approach for a directional observation of boosted Dark Matter with high sensitivity. We show that, with this approach, a 10 kg module of the NEWSdm experiment exposed for one year at the Gran Sasso surface laboratory can probe Dark Matter masses between 1 keV/c$^2$ and 1 GeV/c$^2$ and cross-section values down to $10^{-30}$~cm$^2$ with a directional sensitive search.Comment: 15 pages, 14 figures, updated references, clarified discussion in intro section. Submitted to JCA

NEWSdm Collaboration

Direct Dark Matter searches are nowadays one of the most fervid research topics with many experimental efforts devoted to the search for nuclear recoils induced by the scattering of Weakly Interactive Massive Particles (WIMPs). Detectors able to reconstruct the direction of the nucleus recoiling against the scattering WIMP are opening a new frontier to possibly extend Dark Matter searches beyond the neutrino background. Exploiting directionality would also prove the galactic origin of Dark Matter with an unambiguous signal-to-background separation. Indeed, the angular distribution of recoiled nuclei is centered around the direction of the Cygnus constellation, while the background distribution is expected to be isotropic. Current directional experiments are based on gas TPC whose sensitivity is limited by the small achievable detector mass. In this paper we present the discovery potential of a directional experiment based on the use of a solid target made of newly developed nuclear emulsions and of optical read-out systems reaching unprecedented nanometric resolution

Ремоделирование против реимплантации в хирургии корня аорты: сравнительные результаты и факторы риска аортальной недостаточности

Highlights. The main approaches to the aortic root valve-sparing surgery of are reimplantation and remodeling;The literature review demonstrates either the relative identity of the reimplantation and remodeling clinical outcomes, or the advantage of reimplantation in relation to long-term results.Abstract. In recent decades, valve-sparring methods of aortic root replacement, including reimplantation and remodeling, as well as their modifications, have been developed and put into widespread practice. The effectiveness and durability of these two approaches is the subject of discussions in the modern cardiac surgery community. The global experience in performing remodeling and reimplantation procedures allows  for a comprehensive literature review to compare the results of these approaches.  The presented review is devoted to the comparison of surgical aspects and clinical outcomes of reimplantation and remodeling techniques, the analysis of the feasibility of restoring the physiological architectonics of the aortic root in valve-sparring operations using Valsalva grafts, as well as the assessment of risk factors for residual aortic insufficiency after such interventions. The search strategy included the analysis of international (PubMed, Scopus, Embase) databases for the following keywords: “reimplantation versus remodeling for aortic root valve-sparring procedures”, “David procedure versus Yacoub procedure”, “Valsalva graft for aortic root valve-sparring procedures”, “Valve-sparing aortic root repair with an anatomically shaped sinus prosthesis”. Literature analysis demonstrates either the relative identity of early and long-term results of reimplantation and remodeling procedures, or the advantage of reimplantation in terms of freedom from late mortality and residual aortic insufficiency. Preservation of the physiology of the aortic root by implantation of Valsalva grafts or remodeling provides better hemodynamics and reduces stress on the leaflets, however, these postulates run counter to the data of clinical studies analyzing postoperative outcomes and demonstrating the lack of advantages of Valsalva grafts over linear prostheses in terms of freedom from aortic valve surgery. Residual postoperative regurgitation of a mild degree, a decrease in the effective height below 9 mm and additional interventions on the leaflets are reliable factors of significant aortic insufficiency in the long-term period after valve-sparring operations on the aortic root.Основные положения. Основными методами клапаносохраняющей хирургии корня аорты являются реимплантация и ремоделирование.Анализ литературы демонстрирует либо относительную идентичность клинических исходов реимплантации и ремоделирования, либо преимущество реимплантации в отношении отдаленных результатов.Резюме. В последние десятилетия разработаны и внедрены в широкую практику клапаносохраняющие методики протезирования корня аорты, включая реимплантацию и ремоделирование, а также их модификации. Эффективность   и долговечность этих двух подходов служит предметом бурных обсуждений в современном кардиохирургическом сообществе. Накопленный за три десятилетия глобальный опыт выполнения процедур ремоделирования и реимплантации позволяет провести всесторонний обзор результатов этих подходов. Представленный обзор литературы посвящен сравнению хирургических аспектов и клинических исходов методик реимплантации и ремоделирования, анализу целесообразности восстановления физиологической архитектоники корня аорты при клапаносберегающих операциях с использованием Вальсальва-графтов, а также оценке факторов риска резидуальной аортальной недостаточности после таких вмешательств. Стратегия поиска включила анализ международных баз данных (PubMed, Scopus, Embase) по следующим ключевым словам: reimplantation versus remodeling for aortic root valve-sparring procedures, David procedure versus Yacoub procedure, Valsalva graft for aortic root valve-sparring procedures, Valve-sparing aortic root repair with an anatomically shaped sinus prosthesis. Анализ литературы демонстрирует либо относительную идентичность ранних и отдаленных результатов реимплантации и ремоделирования, либо преимущество реимплантации в отношении свободы от поздней летальности и резидуальной аортальной недостаточности. Сохранение физиологичности корня аорты путем имплантации Вальсальва-графтов или ремоделирования обеспечивает лучшую гемодинамику и снижает напряжение на створки, однако эти постулаты идут вразрез с данными клинических исследований, посвященных анализу послеоперационных исходов и демонстрирующих отсутствие преимущества Вальсальва-графтов над линейными протезами в отношении свободы от реопераций на аортальном клапане. Остаточная послеоперационная регургитация легкой степени, эффективная высота ниже 9 мм и дополнительные вмешательства на створках являются достоверными факторами значимой аортальной недостаточности в отдаленном периоде после клапаносохраняющих операций на корне аорты