Low-temperature specific heat of real crystals: Possibility of leading contribution of optical and short-wavelength acoustical vibrations

We point out that the repeatedly reported glass-like properties of crystalline materials are not necessarily associated with localized (or quasilocalized) excitations. In real crystals, optical and short-wavelength acoustical vibrations remain damped due to defects down to zero temperature. If such a damping is frequency-independent, e.g. due to planar defects or charged defects, these optical and short-wavelength acoustical vibrations yield a linear-in-$T$ contribution to the low-temperature specific heat of the crystal lattices. At low enough temperatures such a contribution will prevail over that of the long-wavelength acoustical vibrations (Debye contribution). The crossover between the linear and the Debye regime takes place at $T^* \propto \sqrt N$, where $N$ is the concentration of the defects responsible for the damping. Estimates show that this crossover could be observable.Comment: 5 pages. v4: Error in Appendix corrected, which does not change the main results of the pape

Influence of cobalt and molybdenum additives on the structure and shape memory parameters of reaction-sintered porous nickel titanium alloys

We have studied the structure and properties of porous nickel titanium (TiNi) alloys obtained upon reaction sintering of Ti and Ni powders with Co and Mo additives. It is established that Co and Mo doping additives retain the compaction of Ni powder achieved at the initial stage of sintering. The maximum deformation of porous samples loaded in the austenite state was observed upon adding Co, while the addition of Mo resulted in minimum deformation. The addition of Co leads to single-stage martensitic transformation in TiNi phase, while the addition of Mo leads to the two-stage transformation that is more homogeneous over the volume. Both Co and Mo additives lead to increase in the maximum accumulated strain due to the formation of favorably oriented stress-induced martensite and reoriented quench-induced martensite

Chalcogenide nanoparticles and organic photosensitizers for synergetic antimicrobial photodynamic therapy

Synergistic antimicrobial effects were observed for copper sulfide (CuS) nanoparticles together with indocyanine green (ICG) in the elimination of wild type pathogenic bacteria (Staphylococcus aureusATCC 29213 andPseudomonas aeruginosaATCC 27853) and also opportunistic fungal infective yeast (Candida albicansATCC 10231). Furthermore, large antibacterial effects were observed for clinical isolates of Methicillin-resistantS. aureus(MRSA) PFGE strain-type USA300. This efficient antimicrobial action was attributed to the combined extra- and intracellular generation of reactive oxygen species upon light irradiation. Instead of the use of visible-light for the activation of common photosensitizers, both ICG and CuS nanoparticles can be activated in the near infrared (NIR)-region of the electromagnetic spectrum and therefore, superior tissue penetration would be expected in a potential elimination of pathogenic microorganisms not only on the skin but also in the soft tissue. In the different bacteria studied a 3-log reduction in the bacterial counts was achieved after only 6 min of NIR irradiation and treatment with ICG or CuS alone at concentrations of 40 and 160 µg mL-1, respectively. A maximum bactericidal effect againstS. aureusand USA300 strains was obtained for the combination of both photosensitizers at the same concentration. RegardingP. aeruginosa, a 4-log reduction in the CFU was observed for the combination of CuS and ICG at various concentrations. InCandida albicansthe combination of both ICG and CuS and light irradiation showed an antimicrobial dose-dependent effect with the reduction of at least 3-log in the cell counts for the combination of ICG + CuS at reduced concentrations. The observed antimicrobial effect was solely attributed to a photodynamic effect and any photothermal effect was avoided to discard any potential thermal injury in a potential clinical application. The generation of reactive oxygen species upon near infrared-light irradiation for those photosensitizers used was measured either alone or in combination. The cytocompatibility of the proposed materials at the doses used in photodynamic therapy was also demonstrated in human dermal fibroblasts and keratinocytes by cell culturing and flow cytometry studies. © The Royal Society of Chemistry 2021

Long-term dynamics of flora of karst lakes: Changes and current state

Long-term observations of the rates and pattern of changes in flora and vegetation contribute to understanding of one of the most important contemporary global problems, the eutrophication of water bodies. In this study, using classical floristic methods, we attempt to determine (for a period of almost 80 years) the nature and possible causes of changes in the floristic composition of the lakes of karst origin, Velikoe and Parovoe (Pustinskaya lake-river system, the right bank of Nizhny Novgorod oblast). The paper shows that over a long period of observations a significant transformation of the vegetation cover has occurred in the lakes. The process was accompanied by the disappearance of a number of native species and appearance of others, including adventitious ones (for example, Elodea canadensis Michx., Zizania latifolia (Griseb.) Stapf, Bidens frondosa L. and Epilobium adenocaulon Hausskn.). The weak saturation of the flora with adventive species indicates that the reservoirs are subject to moderate anthropogenic transformation. This is also indicated by the presence of characteristic indicator species, for example, Najas minor All., Glyceria fluitans (L.) R. Br., Hydrocharis morsus-ranae L. and Stratiotes aloides L. in the plant communities. In addition, the studied water bodies are subject to a further increase in the degree of eutrophication. This can be judged by scattered records of Potamogeton trichoides Cham. et Schlecht., the disappearance of a number of species (such as Elatine alsinastrum L. and Callitriche hermaphroditica L.), as well as the presence of a significant number of macrophyte indicators of the eutrophic state of water bodies. We suggest that a gradual increase in the trophicity of the studied water bodies is due to a combination of anthropogenic impact (water withdrawal for economic needs, recreational load), natural and climatic features of the region (alternation of high and low water periods) and the natural succession processes associated with the current fundamental changes in the conditions of the runoff formation in the Volga River basin. As a result of studies conducted by authors in 2014–2015, it has been shown that in general the taxonomic and ecological structures of the flora of both lakes are quite diverse and traditional for the territory and the European part of Russia. Meanwhile, the flora of these two reservoirs insignificantly differs in taxonomic composition, which is due to their individual morphometric characteristics, the physical and chemical properties of the aquatic environment, and the nature of the anthropogenic load. At the same time, the equilibrium balance of coastal and aquatic plants in the flora of Lake Parovoe (in contrast to Lake Velikoe) indicates a degree of successional stability of its floristic complex.Long-term observations of the rates and pattern of changes in flora and vegetation contribute to understanding of one of the most important contemporary global problems, the eutrophication of water bodies. In this study, using classical floristic methods, we attempt to determine (for a period of almost 80 years) the nature and possible causes of changes in the floristic composition of the lakes of karst origin, Velikoe and Parovoe (Pustinskaya lake-river system, the right bank of Nizhny Novgorod oblast). The paper shows that over a long period of observations a significant transformation of the vegetation cover has occurred in the lakes. The process was accompanied by the disappearance of a number of native species and appearance of others, including adventitious ones (for example, Elodea canadensis Michx., Zizania latifolia (Griseb.) Stapf, Bidens frondosa L. and Epilobium adenocaulon Hausskn.). The weak saturation of the flora with adventive species indicates that the reservoirs are subject to moderate anthropogenic transformation. This is also indicated by the presence of characteristic indicator species, for example, Najas minor All., Glyceria fluitans (L.) R. Br., Hydrocharis morsus-ranae L. and Stratiotes aloides L. in the plant communities. In addition, the studied water bodies are subject to a further increase in the degree of eutrophication. This can be judged by scattered records of Potamogeton trichoides Cham. et Schlecht., the disappearance of a number of species (such as Elatine alsinastrum L. and Callitriche hermaphroditica L.), as well as the presence of a significant number of macrophyte indicators of the eutrophic state of water bodies. We suggest that a gradual increase in the trophicity of the studied water bodies is due to a combination of anthropogenic impact (water withdrawal for economic needs, recreational load), natural and climatic features of the region (alternation of high and low water periods) and the natural succession processes associated with the current fundamental changes in the conditions of the runoff formation in the Volga River basin. As a result of studies conducted by authors in 2014–2015, it has been shown that in general the taxonomic and ecological structures of the flora of both lakes are quite diverse and traditional for the territory and the European part of Russia. Meanwhile, the flora of these two reservoirs insignificantly differs in taxonomic composition, which is due to their individual morphometric characteristics, the physical and chemical properties of the aquatic environment, and the nature of the anthropogenic load. At the same time, the equilibrium balance of coastal and aquatic plants in the flora of Lake Parovoe (in contrast to Lake Velikoe) indicates a degree of successional stability of its floristic complex

Prioritizing otological surgery during the COVID-19 Pandemic

The initial cases of pulmonary infection with the novel corona virus SARS-CoV-2, causing COVID-19, occurred in Wuhan, Hubei Province, China in December 2019 and January 2020 (1). The spread through human-to-human transmission has led to a pandemic with disastrous consequences all over the world. The exponential rate of transmission and no existing vaccine has been a great challenge for all health care systems. A strategy to flatten the curve of transmission was put forward to adjust to the capacities of hospitals and particularly the intensive care units. Governments implemented isolation and social distancing upon societies either with laws or with strong recommendations

Impact of multimorbidity on disability and quality of life in the Spanish older population

Background Population aging is closely related to high prevalence of chronic conditions in developed countries. In this context, health care policies aim to increase life span cost-effectively while maintaining quality of life and functional ability. There is still, however, a need for further understanding of how chronic conditions affect these health aspects. The aim of this paper is to assess the individual and combined impact of chronic physical and mental conditions on quality of life and disability in Spain, and secondly to show gender trends. Methods Cross-sectional data were collected from the COURAGE study. A total of 3,625 participants over 50 years old from Spain were included. Crude and adjusted multiple linear regressions were conducted to detect associations between individual chronic conditions and disability, and between chronic conditions and quality of life. Separate models were used to assess the influence of the number of diseases on the same variables. Additional analogous regressions were performed for males and females. Results All chronic conditions except hypertension were statistically associated with poor results in quality of life and disability. Depression, anxiety and stroke were found to have the greatest impact on outcomes. The number of chronic conditions was associated with substantially lower quality of life [ß for 4+ diseases: -18.10 (-20.95,-15.25)] and greater disability [ß for 4+ diseases: 27.64 (24.99,30.29]. In general, women suffered from higher rates of multimorbidity and poorer results in quality of life and disability. Conclusions Chronic conditions impact greatly on quality of life and disability in the older Spanish population, especially when co-occurring diseases are added. Multimorbidity considerations should be a priority in the development of future health policies focused on quality of life and disability. Further studies would benefit from an expanded selection of diseases. Policies should also deal with gender idiosyncrasy in certain cases

Флора карстовых озер государственного природного заказника «Пустынский» (Нижегородская область)

Pustynsky State Natural Reserve of Regional Importance (area 19,730 hectares) was established by decree of the administration of Nizhny Novgorod oblast on September 16, 2013. It is located in the Tyoshe-Seryozhinsky karst area of the Oka-Sura karst region or Seryozhe-Panskoy karst lake district. Its creation is justified by the need to protect the rare species of living organisms, diverse types of vegetation, unique landscapes and plant communities that are concentrated in this territory. Despite the fact that in 1934 on the shore of the Great Lake in the Staraya Pustyn village the biological station of the State University of Nizhny Novgorod was founded, local flora of the karst lakes which are linked into a single system by the channel of the River Seryozha, remains insufficiently studied. In 2014 and 2015 the authors conducted a study of the flora of the Pustynsky lake-river complex. The collection of material for study of the taxonomic composition of the flora of the reservoirs and the collection of herbarium material were carried out by the route method from a rowing boat and, in part, by traversing along the shore. Taxonomic, ecological (including the spectrum of life forms of plants) and ecobiomorphological analysis of the flora, including the analysis of the ratio of its latitudinal and longitude elements, was carried out in cameral conditions. The taxonomic analysis of flora showed 162 species of vascular plants from 61 genera and 42 families, 6 of these species – Najas minor All., N. major All., Trapa natans L., Potamogeton praelongus Wulf., P. trichoides Cham. et Schlecht. and Carex bohemica Schreb, being included in the List of Rare and Protected Species on the Territory of Nizhny Novgorod oblast. On the basis of the annotated list of plant species, taxonomic, geographic, ecological-coenotic and ecobiomorphological analysis of the flora of the water reservoirs was made. We confirmed that the flora of the lake-river complex is traditional for this territory. Poaceae, Cyperaceae, Potamogetonaceae, Polygonaceae and Asteraceae belong to the dominant families and Potamogeton L., Carex L., Juncus L. and Salix L. belong to the dominant genera of the Pustynsky lake-river system. The level of the hybrid component of the flora is extremely low, which is typical for the watershed lakes. We found that a 6.5 km stretch of the Seryozha River accounts for about 30% of species of the vascular plants belonging to the flora in the Volga River basin. The high species richness of the flora of this territory is due, primarily, to the specific features of the shoreline, forming a broad range of habitats and the relatively stable water level regime despite the strong fluctuation in the level of anthropogenic pressure. We found that boreal and plurizonal elements dominate zonally but Holarctic and Eurasian species – regionally. The predominance of species typical for the ecotone zones of lakes (hygrophytes, hydrophytes and mesophytes) is an integral feature of the ecological-coenotic diversity which is characteristic of the Volga River basin. According to the Raunkiaer classification of life forms, hemicryptophytes are the most numerous group and the hamephytes are the least numerous one. A biomorphological analysis shows the predominance of vegetative mobile, clearly polycentric and vegetative immobile monocentric ecobiomorphs. Государственный природный заказник регионального значения «Пустынский» площадью 19 730 га, образован постановлением правительства Нижегородской области от 16 сентября 2013 г., и расположен в Теше-Сережинском карстовом районе Окско-Сурской карстовой области или Сереже-Пьянском карстовом озерном районе. Его создание обосновано необходимостью охраны редких видов живых организмов, разнообразных типов растительности, уникальных ландшафтов и фитоценозов, сосредоточенных на данной территории. Несмотря на то, что уже в 1934 г. на берегу оз. Великое в с. Старая Пустынь образована биологическая станция Нижегородского государственного университета, флора местных озер карстового происхождения, связанных между собой в единую систему руслом р. Сережа, по-прежнему изучена недостаточно полно. В 2014 и 2015 годах авторами проведено исследование флоры Пустынского озерно-речного комплекса. Выявлен таксономический состав флоры сосудистых растений, насчитывающий 162 вида, из них 6 (Najas minor All., N. major All., Trapa natans L., Potamogeton praelongus Wulf., P. trichoides Cham. et Schlecht. и Carex bohemica Schreb) входят в перечень редких и особо охраняемых видов Нижегородской области. На основе представленного в работе аннотированного списка видов выполнен таксономический, географический, эколого-ценотический и экобиоморфологический анализ флоры водоемов. По таксономической и экологической структуре флора исследуемого озерно-речного комплекса традиционна для данной территории. Различия во флоре отдельных озер обусловлены разнообразием биотопов, степенью сохранности растительного покрова и характером антропогенной нагрузки. Особенностью озерно-речной системы является то, что на участке длиной 6,5 км сосредоточено около 30% таксонов сосудистых растений, входящих в состав флоры бассейна р. Волга.&nbsp

Prevalence, beliefs and impact of drug-drug interactions between antiretroviral therapy and illicit drugs among people living with HIV in Spain

Altres ajuts: ViiV Healthcare (grant 001/2016)Drug use implies important challenges related to HIV management, particularly due to an increased risk of potential interactions between antiretroviral therapy (ART) and illicit drugs (pDDIs). This study analyses the prevalence and severity of pDDIs among people living with HIV (PLHIV). It also explores their awareness of pDDIs and their beliefs about the toxicity that they may cause, as well as the impact of pDDIs on selected health variables. We conducted an on-line cross-sectional survey across 33 Spanish hospitals and NGOs to collect demographics and clinical data. pDDIs were checked against the Interaction Checker developed by Liverpool University. The sample of the present study was composed of 694 PLHIV who used illicit drugs. They represented 49.5% of the 1,401 PLHIV that participated in the survey. After excluding 38 participants due to lack of information on their ART or illicit drug use, 335 (51.1%) participants consuming drugs presented with some potentially significant pDDIs between their ART and illicit drugs, with a mean of 2.1±1.7 (1-10) pDDIs per patient. The drugs most frequently involved in pDDIs were cocaine, cannabis, MDMA and nitrates ("poppers"). The prevalence of pDDIs across ART regimens was: protease inhibitors (41.7%); integrase inhibitor-boosted regimens (32.1%), and non-nucleoside reverse transcriptase inhibitors (26.3%). An awareness of pDDIs and beliefs about their potential toxicity correlated positively with intentional non-adherence (p<0.0001). Participants with pDDIs exhibited a higher prevalence of intentional non-adherence (2.19±1.04 vs. 1.93±0.94; p = 0.001). The presence of pDDIs was not associated with poorer results in the clinical variables analysed. A significant proportion of PLHIV who use drugs experience pDDIs, thereby requiring close monitoring. pDDIs should be considered in the clinical management of HIV patients. Adequate information about pDDIs and indicators about how to manage ART when PLHIV use drugs could improve ART non-adherence