Sort by
Structural forming of soil composites using as a pavement subgrade strengthening

The article substantiates the possibility of obtaining composite materials with improved functional properties to strengthen the subgrade, containing technogenic soil stabilized by an additive based on a gelling polymer. The introduction of technogenic soils into composites will not only reduce the consumption of expensive materials, but also solve a complex of acute environmental problems. Composite materials can be used in the construction of structural layers of road pavements, foundations of buildings and structures, sites for various purposes, for the prevention and elimination of defects in the foundations of engineering structures during their construction, reconstruction and repair, including in permafrost areas. Stabilized technogenic soils are more durable, frost-resistant and waterproof, which makes them applicable for creating impervious curtains in hydraulic structures and sealing storage facilities for hazardous substances. The cryogenic effect on a composite material allows one to vary its properties within a wide range and modify its macroporous structure. Studying the process of structure formation of the resulting organic-inorganic materials, consisting of macromolecules of high-molecular substances and inorganic inclusions that have undergone cryogenic treatment, will make it possible to specifically regulate their performance characteristics. The best values of strength characteristics were obtained for samples with a stabilizing additive concentration of 100g/l. The resulting composite materials are hydrophobic, frost-resistant, characterized by a compressive strength of 2.3-6.5MPa and a thermal conductivity of 0.19-0.20W/(m·K). Data from differential scanning calorimetry and thermogravimetry and IR spectroscopy revealed that the binding of mineral particles by a stabilizing additive occurs due to the formation of organomineral complexes with the participation of clay minerals and the restructuring of hydration shells. SEM data indicate that crystallinity zones formed due to hydrogen bonds of hydroxyl groups of neighboring polymer chains can participate in the formation of the composite structure. An increase in the number of cryogenic treatment cycles promotes additional structuring and strengthening of the polymer phase due to the formation of additional nodes of the supramolecular network, ordering of crystallinity zones and the appearance of compacted areas in the structure. Computed X-ray tomography revealed an increase in the density of the composite upon drying, which helps to increase its strength characteristics. The structure of the sample is characterized by heterogeneity of the pore space, which is characterized by the presence of both fine-porous and large-porous regions, which determines its thermophysical properties.

Open Access Just Published
Relevant
Interventions aiming to improve advance care planning uptake in oncology: a scoping review of recent randomized controlled trials.

The evidence regarding the effectiveness of interventions aiming to improve ACP uptake appears mixed. The purpose of this scoping review is to summarize findings from recent RCTs assessing the efficacy of interventions designed to increase ACP uptake in cancer care. The PubMed database was searched for studies published between 2021 and 2023. Ten RCTs were identified that evaluated a wide range of interventions aimed at encouraging or facilitating ACP communication among patients with advanced cancer, caregivers, and HCPs. Three RCTs developed ACP facilitation tools for patients and sometimes caregivers. Six RCTs involved integrating trained ACP facilitators into patient care, and one RCT used nudges to encourage oncologists trained in ACP discussions to initiate discussions with patients at highest risk of short-term mortality. Most of the reviewed interventions were based on previously tested intervention approaches or tools. The key effects identified in this review are the facilitation of ACP discussions among patients, caregivers, and HCPs, and the documentation of patient preferences in the medical record. The direct involvement of facilitators in ACP document drafting and inclusion in patient files, as well as interventions prompting end-of-life discussions, contributed to this effect.

Open Access Just Published
Relevant
The relationship between a comprehensive index of prosperity and suicide rates in former Soviet countries, including a comparison with European and Asian countries: Discussion from a new perspective

Investigations of suicide in countries of the former Soviet Union, which broke into 15 different countries in the early 1990s, require examinations of a combination of economic, social, and health factors. It is important to address these factors individually and to examine the various composite indicators for each. Moreover, it would be worthwhile to explore the potential applicability of a comprehensive worldwide index. We analyzed data from nine of the former Soviet countries for which both the annual suicide rate and the Global Competitiveness Index (GCI) were available for the years 2006–2017. We determined the precise relationships between the suicide rate and the GCI during this period in these nine countries as well as in nine countries with high suicide rates in Europe and Asia. The results indicated the following: (i) In six of the nine former Soviet countries with complete data, the suicide rate showed a relationship with the GCI. Notably, this relationship was inverse in all but one country. (ii) Among the nine European and Asian countries with high suicide rates, three exhibited a correlation between the suicide rate and the GCI. Measures to prevent suicide should be devised especially in countries of the former Soviet Union through collaboration among multiple fields and organizations, as necessary, with particular attention paid to countries with worse or worsening GCI values.

Just Published
Relevant
Short- and long-term reproducibility of body surface gastric mapping using the Gastric Alimetry® system.

Many diagnostic tests for gastroduodenal symptoms, such as gastric emptying scintigraphy (GES), gastric emptying breath tests (GEBT), and electrogastrography (EGG) show variable intra-individual reproducibility over time. This study investigated the short- and long-term reproducibility of body surface gastric mapping (BSGM), a non-invasive test for assessing gastric function, in controls and patients with chronic gastroduodenal disorders. Participants completed three standardized BSGM tests using Gastric Alimetry® (Alimetry, New Zealand). The test encompassed a fasting baseline (30 min), a 482 kCal standard meal, and a 4 h postprandial recording. The first two tests were >6 months apart and the last occurred ~1 week after the second test, to evaluate long and short-term reproducibility. Fourteen patients with upper gastrointestinal symptoms and 14 healthy controls were recruited. There were no significant differences in any BSGM metrics between the tests at short and long term (all p > 0.180). Lin's concordance correlation coefficients (CCC) for the primary metrics were high, ranging from 0.58 to 0.96, with intra-individual coefficients of variance (CVintra) ranging from 0.2% to 1.9%. Reproducibility was higher, and intra-individual variation lower, than in previous studies of GES (CCC = 0.54-0.83, CVintra = 3%-77%), GEBT (CVintra = 8%-11%), and EGG (CVintra = 3%-78%). BSGM spectral metrics demonstrate high reproducibility and low intra-individual variation at both short and long term, with superior results to comparable tests. The high reproducibility of Gastric Alimetry supports its role as a diagnostic aid for gastric dysfunction and a reliable tool for evaluating treatment outcomes and disease progression over time.

Open Access Just Published
Relevant
Sole-source Lighting of Lettuce that Increased Yield Had No Negative Effect on Postharvest Longevity

The effects of sole-source lighting on the growth and yield of hydroponically grown lettuce have been extensively studied, but research of postharvest performance is limited. We grew frill-leaf lettuce (Lactuca sativa) ‘Green Incised’ and ‘Hydroponic Green Sweet Crisp’ hydroponically in an indoor vertical research farm under daily light integrals (DLIs) of 12 or 18 mol⋅m−2⋅d−1 and the following three ratios of blue (B; 400–499 nm) and red (R; 600–699 nm) light from light-emitting diode fixtures: B5:R95, B20:R80, and B35:R65. We postulated that biomass accumulation would increase with the DLI and decrease with the B light fraction, and that postharvest longevity would increase with the DLI and the B light fraction. As expected, shoot fresh weight, leaf length and width, leaf number, and relative chlorophyll content (SPAD; ‘Green Incised’ only) decreased as the proportion of B light increased from 5% to 35%. Decreasing the DLI from 18 to 12 mol⋅m−2⋅d−1 reduced the shoot fresh weight and leaf number of both cultivars. Leaves of ‘Green Incised’ were up to 27% wider under B5:R95 and 60% longer under B5:R95 at 12 mol⋅m−2⋅d−1 than those under treatments with a higher DLI or more B light. The shoot fresh weight of ‘Hydroponic Green Sweet Crisp’ was greatest when grown under B5:R95 at 18 mol⋅m−2⋅d−1 and decreased as B light increased or DLI decreased. At the time of harvest, leaves of each cultivar and treatment were placed in clamshells and stored at 7 °C in darkness and evaluated for decay. ‘Green Incised’ that grew under B35:R65 and a DLI of 18 mol⋅m−2⋅d−1 had the shortest storage life, with 9.5 d and 11.4 d for replications 1 and 2, respectively, which were ∼2.5 to 4.0 d and 1.4 to 3.6 d earlier, respectively, than the storage life of lettuce grown under other treatments. In contrast, ‘Hydroponic Green Sweet Crisp’ was not influenced by light quality or DLI and had a storage life of 12.6 to 13.3 d and 13.5 to 14.3 d for replications 1 and 2, respectively. Therefore, a B light fraction between 5% and 20% and a DLI of 18 mol⋅m−2⋅d−1 produced high-yielding frill-leaf lettuce with a relatively long storage life.

Just Published
Relevant