Publications by authors named "Berzins R"

The current research is devoted to integrating naturally renewable cardanol derivatives into one-component silyl-terminated-polyether-based prepolymer systems to improve climatic resistance and obtain materials with versatile mechanical properties that could be significant to various sectors of the economy. Various cardanol-type products are used in industries that require high climatic resistance, and thus combining cardanol with commercially available silyl-terminated polyether prepolymers would improve its material climatic resistance, maintaining its market and application value as well as improving material sustainability. The results obtained in this work show that depending on how the cardanol prepolymer Ultra Lite 513 is modified, it is possible to increase the elasticity (670%) or tensile strength (104%) of the material as well as significantly increase the climatic resistance of the material, thus improving the quality and sustainability of the adhesive compared to existing silyl-terminated-prepolymer-based adhesives on the market.

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Article Synopsis
  • Birch outer bark extract (BBE) contains beneficial compounds like betulin and lupeol but suffers from low water solubility, making it hard for the body to absorb effectively.
  • * The study developed an oleogel through a special method to improve the absorption of BBE, showing significant increases in bioavailability with 42-80 times better results for betulin and lupeol in Wistar rats.
  • * The oleogel was safe for repeated use over 7 days and didn't show toxicity in major organs, although lupeol was found in some tissues while betulin and betulinic acid were not detected in organs like the heart and liver.
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Structuring liquid oils into oleogels using natural and abundant biomass components as gelling agents is of great significance in fields such as foods, pharmaceuticals, and cosmetics. In this work, a more energy-efficient and technologically simpler approach for directly preparing birch outer bark extract particles containing oleogel was used. This method involves introducing birch outer bark extract particles into the oil phase directly from the extract solution, combining both the evaporation of solution and gel formation.

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The aim of the study was to obtain untreated and treated betulin colloidal particles and assess their effect on the viability, morphology, proliferation and cytokine secretion of human dermal fibroblasts. To improve bioavailability, betulin treatment was performed by an antisolvent precipitation technique. The average particle size after treatment in the aqueous dispersion decreased from 552.

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The current research is devoted to the research of potential catalysts for the two-component silyl-terminated prepolymer/epoxy resin system. The catalyst system must catalyze the prepolymer of the opposite component while not curing the prepolymer in the component in which the catalyst is located. Mechanical and rheological characterization of the adhesive was performed.

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The current research is devoted to the investigation of the influence of a secondary amine compatibilizer and customized additive package on the tensile, rheological and adhesive properties of a Silyl-terminated polyether (SIL)/Epoxy resin (EP) model and completed two-component systems. A SIL/EP model and completed two-component systems were developed over a broad range of the both pre-polymer ratios (90/10-30/70 wt.-to-wt%).

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Background: Surveying the scientific literature is an important part of early drug discovery; and with the ever-increasing amount of biomedical publications it is imperative to focus on the most interesting articles. Here we present a project that highlights new understanding (e.g.

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  • The study focused on the population composition and dynamics of Caribbean green turtles in juvenile feeding grounds, particularly in Lac Bay, Bonaire, highlighting the importance of understanding migratory megafauna for conservation efforts.
  • Genetic analyses revealed a significant shift in population composition between 2006-2007 and 2015-2016, with juvenile recruitment patterns changing notably from different Caribbean regions.
  • The findings suggest potential issues in reproductive output at certain rookeries and emphasize the need for conservation of juvenile habitats and genetic monitoring to better track megafauna population trends.
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Satellite telemetry is an increasingly utilized technology in wildlife research, and current devices can track individual animal movements at unprecedented spatial and temporal resolutions. However, as we enter the golden age of satellite telemetry, we need an in-depth understanding of the main technological, species-specific and environmental factors that determine the success and failure of satellite tracking devices across species and habitats. Here, we assess the relative influence of such factors on the ability of satellite telemetry units to provide the expected amount and quality of data by analyzing data from over 3,000 devices deployed on 62 terrestrial species in 167 projects worldwide.

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The green turtle Chelonia mydas undertakes wide-ranging migrations between feeding and nesting sites, resulting in mixing and isolation of genetic stocks. We used mtDNA control region to characterize the genetic composition, population structure, and natal origins of C. mydas in the West Atlantic Ocean, at one feeding ground (State of Rio de Janeiro, Brazil), and three Caribbean nesting grounds (French Guiana, Guadeloupe, and Suriname).

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In response to seasonality and spatial segregation of resources, sea turtles undertake long journeys between their nesting sites and foraging grounds. While satellite tracking has made it possible to outline their migration routes, we still have little knowledge of how they select their foraging grounds and adapt their migration to dynamic environmental conditions. Here, we analyzed the trajectories and diving behavior of 19 adult green turtles (Chelonia mydas) during their post-nesting migration from French Guiana and Suriname to their foraging grounds off the coast of Brazil.

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Polecat populations show a very low genetic diversity and a high inbreeding coefficient. Furthermore, the estimate of effective population size is alarmingly low. Polecats Mustela putorius populations are structured into scattered breeding sub-units usually made up of one male and two females, according to a polygynous mating system.

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Sogn hemoglobinopathy was identified in a young American woman and in a young American man of apparently unrelated families of Norwegian ancestry. Both persons were asymptomatic and without clinical or hematologic manifestations. Hemoglobin Sogn, beta(A11)14 Leu----Arg, is an unstable hemoglobin that may easily be mistaken for hemoglobin S, G, or D by alkaline hemoglobin electrophoresis.

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We measured transhepatic C-peptide and insulin concentrations in plasma, and hepatic removal of insulin, to examine whether the practice of reporting the C-peptide:insulin molar ratio as a measure of the hepatic removal of insulin is valid. In anesthetized dogs (n = 6), during electromagnetic hepatic blood flow monitoring, endogenous insulin was suppressed with somatostatin, while equimolar proportions of porcine insulin and simian C-peptide (2.4 and 6.

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The mechanisms of time-related reduction in lidocaine clearance were studied using a "one-pass" perfused rat liver system. Lidocaine was infused continuously for a period up to 150 min (concentration ranged from 9.6 to 278 microM).

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We simultaneously measured hepatic insulin removal invasively and estimated hepatic clearance and extraction of insulin pharmacokinetically from cardiac output and peripheral plasma concentrations (relatively) noninvasively. The invasive methods involved continuous electromagnetic measurements of portal venous and hepatic arterial blood flow and simultaneous intermittent sampling of blood from the portal and hepatic veins and femoral artery for assay of insulin concentrations. The noninvasive method assumed that hepatic plasma flow is proportional to cardiac output and that hepatic clearance is a constant fraction of total body clearance of insulin.

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Rates of entry of alanine and glycerol and their contribution to glucose synthesis were studied in 48-h fasted White Leghorn cockerels using primed constant intravenous infusions of L-[U-14C]alanine and [U-14C]glycerol. Entry rates of alanine and glycerol were 112 and 401 mumol/h per kg body weight, respectively. Of the total glucose irreversible loss (entry rate), 1.

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Rates of entry and oxidation of D(-)-3-hydroxybutyrate (DBHB) and glucose and their contribution to the total metabolic production of CO2 were studied in fed and 48-hr fasted Leghorn roosters using primed constant intravenous infusions of NaH14CO3, D(-)-3-[3-14C]-hydroxybutyrate, and D-[U-14C] glucose. Fasting increased plasma DBHB concentrations sixfold but did not change plasma glucose levels. In both states of nutrition, rates of CO2 production were identical (P greater than .

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Twenty-four feedlot steers and four sheep were fed roughage or grain rations while three other sheep received intraduodenal infusions of amino acids, glucose, volatile fatty acids, and proteins to determine whether the release of plasma glucagon-like immunoreactivity is influenced by dietary factors and the composition of duodenal chyme. Plasma glucagon-like immunoreactivity rose in both cattle and sheep as the proportion of grain in their rations was increased. In response to intraduodenal infusions, only glucose stimulated glucagon-like immunoreactivity release.

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