Untersuchungen zur Elimination von natürlichen Uranspezies aus Wässern mit Hilfe schwach basischer Anionenaustauscher

Die Gleichgewichtslage, die Kinetik und die Filterdynamik der Sorption von Uranspezies an verschiedene schwach basische Ionenaustauscher aus pH-neutralen Wässern wurden untersucht. Die ermittelten Gleichgewichtsbeladungen sind außerordentlich hoch. Haupteinflussfaktoren sind der pH-Wert und die Calciumkonzentration in der Lösung. Filterexperimente zeigen sehr lange Laufzeiten der Austauscher. Die Modellierung des Filterverhaltens zeigt für die Anfangsphase des Durchbruchs sehr gute Vorhersagen

Sorptive removal of short‑chain perfluoroalkyl substances (PFAS) during drinking water treatment using activated carbon and anion exchanger

Laboratory tests and column tests were carried out in a waterwoks to investigate the removal of short- and longchain PFAS using activated carbon filtration and ion exchange treatment. For all adsorbents, the sorption affinity of short-chain per- and polyfluoroalkyl carboxylic acids (PFCA) was significantly lower than that of long-chain PFAS or short-chain per- and polyfluoroalkyl sulfonic acids (PFSA). In the PFAS-polluted groundwater matrix, the short-chain PFCA PFBA and PFPeA could only be sufficiently removed with activated carbon over short run times of 6000 and 11,000 bed volumes (BV), respectively. Longer PFCA with a chain length of C6 or more were removed over longer run times. The removal of short-chain PFCA using ion exchange media could also only be achieved over relatively short run times of 5000 BV for PFBA, 10,000BV for PFPeA and 18,000 BV for PFHxA. These are sometimes significantly longer than those of activated carbon. Due to the higher material costs for ion exchange media, there are nevertheless no lower operating costs when the ion exchangers are used in single-use mode. However, ion exchangers can be regenerated and then reused which can result in economic advantages compared to activated carbon filtration. However, for the extensive regeneration, especially for the elution of the long-chain PFAS, the additional use of ethanol is needed in the process. In contrast, the short-chain PFBA and PFPeA can be extracted without organic solvent from a weakly basic ion exchanger

Single-Molecule Real-Time (SMRT) Full-Length RNA-Sequencing Reveals Novel and Distinct mRNA Isoforms in Human Bone Marrow Cell Subpopulations.

Hematopoietic cells are continuously replenished from progenitor cells that reside in the bone marrow. To evaluate molecular changes during this process, we analyzed the transcriptomes of freshly harvested human bone marrow progenitor (lineage-negative) and differentiated (lineage-positive) cells by single-molecule real-time (SMRT) full-length RNA-sequencing. This analysis revealed a ~5-fold higher number of transcript isoforms than previously detected and showed a distinct composition of individual transcript isoforms characteristic for bone marrow subpopulations. A detailed analysis of messenger RNA (mRNA) isoforms transcribed from the ANXA1 and EEF1A1 loci confirmed their distinct composition. The expression of proteins predicted from the transcriptome analysis was evaluated by mass spectrometry and validated previously unknown protein isoforms predicted e.g., for EEF1A1. These protein isoforms distinguished the lineage negative cell population from the lineage positive cell population. Finally, transcript isoforms expressed from paralogous gene loci (e.g., CFD, GATA2, HLA-A, B, and C) also distinguished cell subpopulations but were only detectable by full-length RNA sequencing. Thus, qualitatively distinct transcript isoforms from individual genomic loci separate bone marrow cell subpopulations indicating complex transcriptional regulation and protein isoform generation during hematopoiesis

Impaired CXCL12 signaling contributes to resistance of pancreatic cancer subpopulations to T cell-mediated cytotoxicity

Pancreatic cancer remains largely unresponsive to immune modulatory therapy attributable in part to an immunosuppressive, desmoplastic tumor microenvironment. Here, we analyze mechanisms of cancer cell-autonomous resistance to T cells. We used a 3D co-culture model of cancer cell spheroids from the KPC (LSL-Kras(G12D/+)/LSL-Trp53(R172H/+)/p48-Cre) pancreatic ductal adenocarcinoma (PDAC) model, to examine interactions with tumor-educated T cells isolated from draining lymph nodes of PDAC-bearing mice. Subpopulations of cancer cells resistant to these tumor-educated T cells were isolated from the in vitro co-culture and their properties compared with sensitive cancer cells. In co-culture with resistant cancer cell subpopulations, tumor-educated T cells showed reduced effector T cell functionality, reduced infiltration into tumor cell spheroids and decreased induction of apoptosis. A combination of comparative transcriptomic analyses, cytometric and immunohistochemistry techniques allowed us to dissect the role of differential gene expression and signaling pathways between sensitive and resistant cells. A decreased expression of the chemokine CXCL12 (SDF-1) was revealed as a common feature in the resistant cell subpopulations. Adding back CXCL12 reversed the resistant phenotype and was inhibited by the CXCR4 inhibitor AMD3100 (plerixafor). We conclude that reduced CXCL12 signaling contributes to PDAC subpopulation resistance to T cell-mediated attack

Decreased cortical thickness mediates the relationship between premature birth and cognitive performance in adulthood

Cortical thickness (CTh) reflects cortical properties such as dendritic complexity and synaptic density, which are not only vulnerable to developmental disturbances caused by premature birth but also highly relevant for cognitive performance. We tested the hypotheses whether CTh in young adults is altered after premature birth and whether these aberrations are relevant for general cognitive abilities. We investigated CTh based on brain structural magnetic resonance imaging and surface‐based morphometry in a large and prospectively collected cohort of 101 very premature‐born adults (<32 weeks of gestation and/or birth weight [BW] below 1,500 g) and 111 full‐term controls at 26 years of age. Cognitive performance was assessed by full‐scale intelligence quotient (IQ) using the Wechsler Adult Intelligence Scale. CTh was reduced in frontal, parietal, and temporal associative cortices predominantly in the left hemisphere in premature‐born adults compared to controls. We found a significant positive association of CTh with both gestational age and BW, particularly in the left hemisphere, and a significant negative association between CTh and intensity of neonatal treatment within limited regions bilaterally. Full‐scale IQ and CTh in the left hemisphere were positively correlated. Furthermore, CTh in the left hemisphere acted as a mediator on the association between premature birth and full‐scale IQ. Results provide evidence that premature born adults have widespread reduced CTh that is relevant for their general cognitive performance. Data suggest lasting reductions in cortical microstructure subserving CTh after premature birth

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements