Composite building materials based on nanomodified cement systems

ABSTRACT: Introduction. This research work investigates the combined influence of nano-sized silicon dioxide (nano-SiO2 ), carbon nanotubes and surfactants on the structural and technological characteristics of cement compositions. Materials and research methods. The paper reveals the findings of a study on the effects of various dispersion techniques of carbon nanotubes (CNT) in surfactants, such as mechanical dispersion, ultrasonic treatment, and a combined method. It considers the uniformity of CNT distribution within the plasticizer and within the cement system, along with their impacts on the physical and mechanical properties of cement stone and concrete. Differential thermal and electron microscopic analysis of aqueous dispersions of carbon nanotubes and hardened activated nanomodified cement stone was carried out. Results and discussion. It has been experimentally proven that mixing nanotubes in dry cement does not allow them to be evenly distributed throughout the volume of the mixture. When using carbon nanotubes, the maximum effect is achieved when they are introduced into aqueous dispersions of plasticizers. The percentage of plasticizer was 1%, CNT 0,1% per 1 liter of water. The most effective method of dispersing carbon nanotubes in a plasticizer is a combined one. The results obtained were used in the preparation of cement stone and concrete compositions. Conclusion. The results show that complex additives consisting of nano-SiO2 and aqueous dispersions of carbon nanotubes have a positive effect on the physical-mechanical and structural-technological properties of cement stone and concrete. Graphic dependencies are shown indicating the effectiveness of using complex additives in the production of cement composite

Genetic landscape in Russian patients with familial left ventricular noncompaction

BackgroundLeft ventricular noncompaction (LVNC) cardiomyopathy is a disorder that can be complicated by heart failure, arrhythmias, thromboembolism, and sudden cardiac death. The aim of this study is to clarify the genetic landscape of LVNC in a large cohort of well-phenotyped Russian patients with LVNC, including 48 families (n=214).MethodsAll index patients underwent clinical examination and genetic analysis, as well as family members who agreed to participate in the clinical study and/or in the genetic testing. The genetic testing included next generation sequencing and genetic classification according to ACMG guidelines.ResultsA total of 55 alleles of 54 pathogenic and likely pathogenic variants in 24 genes were identified, with the largest number in the MYH7 and TTN genes. A significant proportion of variants −8 of 54 (14.8%) −have not been described earlier in other populations and may be specific to LVNC patients in Russia. In LVNC patients, the presence of each subsequent variant is associated with increased odds of having more severe LVNC subtypes than isolated LVNC with preserved ejection fraction. The corresponding odds ratio is 2.77 (1.37 −7.37; p <0.001) per variant after adjustment for sex, age, and family.ConclusionOverall, the genetic analysis of LVNC patients, accompanied by cardiomyopathy-related family history analysis, resulted in a high diagnostic yield of 89.6%. These results suggest that genetic screening should be applied to the diagnosis and prognosis of LVNC patients

Hotspots in the grid: Avian sensitivity and vulnerability to collision risk from energy infrastructure interactions in Europe and North Africa

Wind turbines and power lines can cause bird mortality due to collision or electrocution. The biodiversity impacts of energy infrastructure (EI) can be minimised through effective landscape-scale planning and mitigation. The identification of high-vulnerability areas is urgently needed to assess potential cumulative impacts of EI while supporting the transition to zero carbon energy. We collected GPS location data from 1,454 birds from 27 species susceptible to collision within Europe and North Africa and identified areas where tracked birds are most at risk of colliding with existing EI. Sensitivity to EI development was estimated for wind turbines and power lines by calculating the proportion of GPS flight locations at heights where birds were at risk of collision and accounting for species' specific susceptibility to collision. We mapped the maximum collision sensitivity value obtained across all species, in each 5 × 5 km grid cell, across Europe and North Africa. Vulnerability to collision was obtained by overlaying the sensitivity surfaces with density of wind turbines and transmission power lines. Results: Exposure to risk varied across the 27 species, with some species flying consistently at heights where they risk collision. For areas with sufficient tracking data within Europe and North Africa, 13.6% of the area was classified as high sensitivity to wind turbines and 9.4% was classified as high sensitivity to transmission power lines. Sensitive areas were concentrated within important migratory corridors and along coastlines. Hotspots of vulnerability to collision with wind turbines and transmission power lines (2018 data) were scattered across the study region with highest concentrations occurring in central Europe, near the strait of Gibraltar and the Bosporus in Turkey. Synthesis and applications. We identify the areas of Europe and North Africa that are most sensitive for the specific populations of birds for which sufficient GPS tracking data at high spatial resolution were available. We also map vulnerability hotspots where mitigation at existing EI should be prioritised to reduce collision risks. As tracking data availability improves our method could be applied to more species and areas to help reduce bird-EI conflicts

Biological Earth observation with animal sensors

Space-based tracking technology using low-cost miniature tags is now delivering data on fine-scale animal movement at near-global scale. Linked with remotely sensed environmental data, this offers a biological lens on habitat integrity and connectivity for conservation and human health; a global network of animal sentinels of environmen-tal change

Evaporation as a Method for Obtaining Plant Concentrates

Low-pressure vacuum evaporation is an effective way to obtain dry concentrates. However, some factors may affect its efficiency and speed. This article introduces the effect of technological factors on the evaporation process in a rotary evaporator. The research objective was to select the optimal mode to obtain concentrates and extracts from plant materials. The experimental studies involved standard research methods and a BUCHI Rotavapor laboratory rotary evaporator (BUCHI, Switzerland). The research featured a water-alcohol extract of wild blueberries and an enzymatic hydrolysate of grain sorghum (durra), obtained by biotechnological treatment with amylolytic enzyme preparations. The optimal evaporation mode included the following values: the volume of the evaporation flask was 1 L; the wall thickness of the flask was 1.8 mm; the angle of inclination was 25°; the rotation speed was 280 rpm; the temperature heating bath was 50–60°C; the steam temperature in the evaporator was 30–40°C. For condensation, the temperature of the refrigerant in the condenser was 10–20°C. The experiment yielded a concentrate of blue-violet blueberries with 70–72% solids. The content of polyphenolic compounds was 1.86 times as high as in the original water-alcohol extract while that of anthocyanins was 1.4 times as high. The enzymatic hydrolysate of grain sorghum yielded a condensed sugar syrup with 78–80% solids and 91–92% reducing sugars in terms of glucose equivalent. The research provided optimal modes of evaporation for extracts and enzymatic hydrolysates from plant raw materials in a rotary evaporator. The plant concentrates had a high content of solids and maintained the sensory properties of the raw material

Binding ability of first and second generation/carbazolylphenyl dendrimers with Zn(II) tetraphenylporphyrin core towards small heterocyclic substrates

A study of complex formation of Zn(ii) tetraarylporphyrin dendrimers with carbazolylphenyl branches towards 1,4-diazabicyclo-[2.2.2]octane, pyridine, imidazole, N-methylimidazole and 1,2,3-triazole was carried out by spectrophotometric and 1H NMR titration methods. It has been shown that the binding ability of the porphyrin receptors towards mono and bidentate N-containing substrates depends on the nature, number and generation of the branches. Bulky substituents are able either to significantly reduce the binding ability of the tetrapyrrolic cores due to the shielding of the porphyrin reaction centres, or to significantly increase it by forming intramolecular cavities for complementary binding of substrates. It has been determined that due to a good geometric match of the ligand's size with the size of the intramolecular cavities of the porphyrin receptors, and by the existence of additional hydrogen bonding and/or π-π interactions between the ligand and the triazole fragments of the porphyrin the Zn-tetraarylporphyrins with eight 4-carbazolylphenyl-1,2,3-triazole end groups of the first and the second generations could be used as effective receptors for imidazole, N-methylimidazole and 1,2,3-triazole. Taking into account the fact that binding is accompanied by a clear and easily identifiable response in the UV-Vis spectra of the reaction mixture, these metalloporphyrins could be considered as molecular optical sensing devices for small heterocyclic substrates. © 2014 the Partner Organisations.status: publishe

Correspondence

Assessing the causes of breeding failure among the rough-legge

Expression pattern of dd4, a sole member of the d4 family of transcription factors in Drosophila melanogaster

In vertebrates, three members of the d4 gene family code for proteins, which are believed to function as transcription factors and involved in regulation of various intracellular processes. One member of the family, ubi-d4/requiem is ubiquitously expressed gene and two other, neuro-d4 and cer-d4, are expressed predominantly in the neural tissues (Nucleic Acids Res. 20 (1992) 5579; Biochim. Biophys. Acta 14 (1992) 172; Mamm. Genome 11 (2000) 72; Mamm. Genome 12 (2001) 862). Typically, d4 proteins show distinct domain organisation with domain 2/3 in the N-terminal, Krüppel-type zinc finger in the central and two adjacent PHD-fingers (d4-domain) in the C-terminal part of the molecule. However, alternative splicing, which is responsible for complex expression patterns of both neurospecific members of the family, generates multiple protein isoforms lacking certain domains (Nucleic Acids Res. 20 (1992) 5579; Genomics 36 (1996) 174; Mamm. Genome 11 (2000) 72; Mamm. Genome 12 (2001) 862). Exact function of d4 proteins is unclear but their involvement in regulation of differentiation and apoptotic cell death has been proposed (J. Biol. Chem. 269 (1994) 29515; Mamm. Genome 11 (2000) 72; Mamm. Genome 12 (2001) 862). Here we identified a single gene, dd4, in the genome of Drosophila melanogaster, the protein product of which could be assigned to the d4 family. Expression of dd4 is regulated during Drosophila development, and is most prominent in syncytial embryos and later in the embryonic nervous and reproductive systems. In flies dd4 mRNA is found in most tissues but the highest level of expression is detected in ovaries

Estimation of Uptake of Humic Substances from Different Sources by Escherichia coli Cells under Optimum and Salt Stress Conditions by Use of Tritium-Labeled Humic Materials▿

The primary goal of this paper is to demonstrate potential strengths of the use of tritium-labeled humic substances (HS) to quantify their interaction with living cells under various conditions. A novel approach was taken to study the interaction between a model microorganism and the labeled humic material. The bacterium Escherichia coli was used as a model microorganism. Salt stress was used to study interactions of HS with living cells under nonoptimum conditions. Six tritium-labeled samples of HS originating from coal, peat, and soil were examined. To quantify their interaction with E. coli cells, bioconcentration factors (BCF) were calculated and the amount of HS that penetrated into the cell interior was determined, and the liquid scintillation counting technique was used as well. The BCF values under optimum conditions varied from 0.9 to 13.1 liters kg−1 of cell biomass, whereas under salt stress conditions the range of corresponding values increased substantially and accounted for 0.2 to 130 liters kg−1. The measured amounts of HS that penetrated into the cells were 23 to 167 mg and 25 to 465 mg HS per kg of cell biomass under optimum and salt stress conditions, respectively. This finding indicated increased penetration of HS into E. coli cells under salt stress

Nest association between two predators as a behavioral response to the low density of rodents

Many birds nest in association with aggressive birds of other species to benefit from their protection against predators. We hypothesized that the protective effect also could extend to foraging resources, whereby the resultant resource-enriched habitats near a nest of aggressive raptors could be an alternative cause of associations between nesting bird species with non-overlapping foraging niches. In the Arctic, the Rough-legged Hawk (Buteo lagopus) and the Peregrine Falcon (Falco peregrinus) are 2 raptor species with non-overlapping food resources that have been reported to nest sometimes in close proximity. Since nesting Peregrine Falcons are very aggressive, they may protect the small rodent prey near their nests from predation, and Rough-legged Hawks could use these hot spots as a nesting territory. In 2 regions in low Arctic Russia we found that (1) the nesting territories of Peregrine Falcons were indeed enriched with small rodents as compared to control areas, (2) the probability of nest association between the 2 raptors increased when rodent abundance was generally low in the region where hawks did not use alternative prey, and (3) hawk reproductive success increased when nesting close to Peregrine Falcons. These results suggest that implications of aggressive nest site defense in birds in certain cases may involve more mechanisms than previously explored. A key ecological process in tundra, rodent population cycles, may explain the occurrence and adaptive significance of a specific behavior pattern, the nesting association between 2 raptor species