Innovative inorganic binder systems for the production of cores for non-ferrous metal alloys reflecting the product quality requirements

The aim of this study is the evaluation of the parameters of core mixtures using different binder systems with regard to the collapsibility of cores after casting and the resulting product quality of castings reflecting surface requirements based on non-ferrous alloys. The research compares organically bonded core mixtures based on phenol-formaldehyde resins for the production of cores with the shell molding (resin coated sand), currently used in the production of aluminum alloy castings in the Brembo Czech s.r.o., and mixtures using innovative inorganic binder systems based on geopolymers; GEOPOL(R) W. The aim of the research is to compare the advantages and disadvantages of these binder systems in order to evaluate the potential of inorganically bonded mixtures to replace organically bonded mixtures, which would lead to a significant reduction in the environmental impacts of industrial production of castings.Web of Science115art. no. 73

Chemistry and Sr–Nd isotope signature of amphiboles of the magnesio-hastingsite-pargasite-kaersutite series in Cenozoic volcanic rocks: Insight into lithospheric mantle beneath the Bohemian Massif

Amphibole phenocrysts and xenocrysts from Cenozoic volcanic rocks of the Bohemian Massif (BM) belong to the magnesio-hastingsite-pargasite-kaersutite series. Their host rocks are mostly basaltic lavas, dykes and breccia pipe fills, less commonly also felsic rocks from rift zones along lithospheric block boundaries of the BM. The calculated p–T conditions suggest that almost all amphiboles crystallized in a relatively narrow temperature range (1020–1100 °C) at depths of 20–45 km (0.7–1.2 GPa) during the magma ascent. The initial 143Nd/144Nd and 87Sr/86Sr ratios of amphiboles (0.51266–0.51281 and 0.70328–0.70407, respectively) are similar to those of their whole rocks (0.51266–0.51288 and 0.70341–0.70462, respectively). This testifies to locally elevated proportions of recycled Variscan crustal material during melting of mantle peridotites rich in clinopyroxene–amphibole veins. These veins were formed by metasomatic fluids enriched in High Field Strength Elements and are isotopically similar to EM-1 mantle type.Fenokrysty a xenokrysty amfibolů kenozoických vulkanických hornin Českého masivu (ČM) náleží svým složením do magnesiohastingsit-pargasit-kaersutitové série. Jejich hostitelské horniny jsou především bazaltické lávy, žíly nebo brekciovité výplně komínů, méně často také felsické horniny z riftových zón podél hranic litosférických bloků ČM. Vypočtené p-T podmínky ukazují, že téměř všechny amfiboly krystalizovaly v relativně úzkém teplotním rozmezí (1020–1100 °C) v hloubkách 20–45 km (0,7–1,2 GPa) během výstupu magmatu. Iniciální izotopové poměry 143Nd/144Nd a 87Sr/86Sr v amfibolech jsou v rozmezí 0,51266–0,51281 a 0,70328–0,70407. To vypovídá o lokálně zvýšeném množství recyklovaného variského korového materiálu během tavení plášťového peridotitu bohatého na klinopyroxen-amfibolové žíly. Tyto žíly vznikly z metasomatických fluid obohacených o prvky s velkým iontovým potenciálem a jsou izotopově podobné obohacenému plášti typu 1 (EM-1)

Air pollution exposure during critical time periods in gestation and alterations in cord blood lymphocyte distribution: a cohort of livebirths

<p>Abstract</p> <p>Background</p> <p>Toxic exposures have been shown to influence maturation of the immune system during gestation. This study investigates the association between cord blood lymphocyte proportions and maternal exposure to air pollution during each gestational month.</p> <p>Methods</p> <p>Cord blood was analyzed using a FACSort flow cytometer to determine proportions of T lymphocytes (CD3⁺cells and their subsets, CD4⁺and CD8⁺), B lymphocytes (CD19⁺) and natural killer (NK) cells. Ambient air concentrations of 12 polycyclic aromatic hydrocarbons (PAH) and particulate matter < 2.5 micrometer in diameter (PM_2.5) were measured using fixed site monitors. Arithmetic means of these pollutants, calculated for each gestational month, were used as exposure metrics. Data on covariates were obtained from medical records and questionnaires. Multivariable linear regression models were fitted to estimate associations between monthly PAH or PM_2.5and cord blood lymphocytes, adjusting for year of birth and district of residence and, in further models, gestational season and number of prior live births.</p> <p>Results</p> <p>The adjusted models show significant associations between PAHs or PM_2.5during early gestation and increases in CD3⁺and CD4⁺lymphocytes percentages and decreases in CD19⁺and NK cell percentages in cord blood. In contrast, exposures during late gestation were associated with decreases in CD3⁺and CD4⁺fractions and increases in CD19⁺and NK cell fractions. There was no significant association between alterations in lymphocyte distribution and air pollution exposure during the mid gestation.</p> <p>Conclusions</p> <p>PAHs and PM_2.5in ambient air may influence fetal immune development via shifts in cord blood lymphocytes distributions. Associations appear to differ by exposure in early versus late gestation.</p

The Impact of Individualized Hemodynamic Management on Intraoperative Fluid Balance and Hemodynamic Interventions during Spine Surgery in the Prone Position: A Prospective Randomized Trial

Background and Objectives: The effect of individualized hemodynamic management on the intraoperative use of fluids and other hemodynamic interventions in patients undergoing spinal surgery in the prone position is controversial. This study aimed to evaluate how the use of individualized hemodynamic management based on extended continuous non-invasive hemodynamic monitoring modifies intraoperative hemodynamic interventions compared to conventional hemodynamic monitoring with intermittent non-invasive blood pressure measurements. Methods: Fifty adult patients (American Society of Anesthesiologists physical status I&ndash;III) who underwent spinal procedures in the prone position and were then managed with a restrictive fluid strategy were prospectively randomized into intervention and control groups. In the intervention group, individualized hemodynamic management followed a goal-directed protocol based on continuously non-invasively measured blood pressure, heart rate, cardiac output, systemic vascular resistance, and stroke volume variation. In the control group, patients were monitored using intermittent non-invasive blood pressure monitoring, and the choice of hemodynamic intervention was left to the discretion of the attending anesthesiologist. Results: In the intervention group, more hypotensive episodes (3 (2&ndash;4) vs. 1 (0&ndash;2), p = 0.0001), higher intraoperative dose of ephedrine (0 (0&ndash;10) vs. 0 (0&ndash;0) mg, p = 0.0008), and more positive fluid balance (680 (510&ndash;937) vs. 270 (196&ndash;377) ml, p &lt; 0.0001) were recorded. Intraoperative norepinephrine dose and postoperative outcomes did not differ between the groups. Conclusions: Individualized hemodynamic management based on data from extended non-invasive hemodynamic monitoring significantly modified intraoperative hemodynamic management and was associated with a higher number of hemodynamic interventions and a more positive fluid balance

Modeling unobserved heterogeneity in susceptibility to ambient benzoapyrene concentration among children with allergic asthma using a mixture-based clustering approach

Current studies of gene × air pollution interaction typically seek to identify unknown heritability of common complex illnesses arising from variability in the host’s susceptibility to environmental pollutants of interest. Accordingly, a single component generalized linear models are often used to model the risk posed by an environmental exposure variable of interest in relation to a priori determined DNA variants. However, reducing the phenotypic heterogeneity may further optimize such approach, primarily represented by the modeled DNA variants. Here, we reduce phenotypic heterogeneity of asthma severity, and also identify single nucleotide polymorphisms (SNP) associated with phenotype subgroups. Specifically, we first apply an unsupervised learning algorithm method and a non-parametric regression to find a biclustering structure of children according to their allergy and asthma severity. We then identify a set of SNPs most closely correlated with each sub-group. We subsequently fit a logistic regression model for each group against the healthy controls using benzo[a]pyrene (B[a]P) as a representative airborne carcinogen. Application of such approach in a case-control data set shows that SNP clustering may help to partly explain heterogeneity in children’s asthma susceptibility in relation to ambient B[a]P concentration with greater efficiency.Peer ReviewedPostprint (published version