Phosphoinositide-dependent kinase 1 controls migration and malignant transformation but not cell growth and proliferation in PTEN-null lymphocytes

In normal T cell progenitors, phosphoinositide-dependent kinase l (PDK1)–mediated phosphorylation and activation of protein kinase B (PKB) is essential for the phosphorylation and inactivation of Foxo family transcription factors, and also controls T cell growth and proliferation. The current study has characterized the role of PDK1 in the pathology caused by deletion of the tumor suppressor phosphatase and tensin homologue deleted on chromosome 10 (PTEN). PDK1 is shown to be essential for lymphomagenesis caused by deletion of PTEN in T cell progenitors. However, PTEN deletion bypasses the normal PDK1-controlled signaling pathways that determine thymocyte growth and proliferation. PDK1 does have important functions in PTEN-null thymocytes, notably to control the PKB–Foxo signaling axis and to direct the repertoire of adhesion and chemokine receptors expressed by PTEN-null T cells. The results thus provide two novel insights concerning pathological signaling caused by PTEN loss in lymphocytes. First, PTEN deletion bypasses the normal PDK1-controlled metabolic checkpoints that determine cell growth and proliferation. Second, PDK1 determines the cohort of chemokine and adhesion receptors expressed by PTEN-null cells, thereby controlling their migratory capacity

Für | For Manfred from his Students

Dieses Buch enthält Beiträge von Personen, die ihre Magister- oder Doktorarbeit unter der Betreuung von Manfred Krifka geschrieben haben. Es ist als kleines Abschiedsgeschenk für Manfred Krifka zum Ende seiner Amtszeit als Direktor des Leibniz-Zentrums für Allgemeine Sprachwissenschaft gedacht. Die Herausgeberin und der Herausgeber haben Beiträge zu sprachwissenschaftlichen und nicht-sprachwissenschaftlichen Themen in einer Vielzahl von Genres gesammelt. Diese Vielfalt spiegelt die Interessen und Forschungsthemen von Manfred Krifka wider. Sie spiegelt auch die Vielfalt der Menschen wider, denen Manfred Krifka geholfen hat

Impact of Sodium Hexametaphosphate on the Flotation of Ultrafine Magnesite from Dolomite-Rich Desliming Tailings

The depletion of ore deposits, the increasing demand for raw materials, the need to process low-grade, complex and finely disseminated ores, and the reprocessing of tailings are challenges especially for froth flotation separation technologies. Even though they are capable of handling relatively fine grain sizes, the flotation separation of very fine and ultrafine particles faces many problems still. Further, the flotation of low-contrast semi-soluble salt-type minerals with very similar surface properties, many complex interactions between minerals, reagents and dissolved species often result in poor selectivity. This study investigates the flotation beneficiation of ultrafine magnesite rich in dolomite from desliming, currently reported to the tailings. The paper especially focuses on the impact of the depressant sodium hexametaphosphate (SHMP) on the following: (i) the froth properties using dynamic froth analysis (DFA), (ii) the separation between magnesite and dolomite/calcite, and (iii) its effect on the entrainment. As a depressant/dispersant, SHMP has a beneficial impact on the flotation separation between magnesite and dolomite. However, there is a trade-off between grade and recovery, and as well as the dewatering process which needs to be considered. When the SHMP increases from 200 g/t to 700 g/t, the magnesite grade increases from 67% to 77%, while recovery decreases massively, from 80% to 40%. The open circuit with four cleaning stages obtained a concentrate assaying 77.5% magnesite at a recovery of 45.5%. The dolomite content in the concentrate is about 20%, where 80% of dolomite was removed and importantly 98% of the quartz was removed, with only 0.3% of the quartz in the final concentrate. Furthermore, the application of 1-hydroxyethylene-1,1-diphosphonic acid (HEDP) as a more environmentally friendly and low-cost alternative to SHMP is presented and discussed. Using only 350 g/t of HEDP can achieve a similar grade (76.3%), like 700 g/t of SHMP (76.9%), while obtaining a 17% higher magnesite recovery as compared to 700 g/t of SHMP. Interestingly, the proportion of hydrophilic quartz minerals ending up in the concentrate is lower for HEDP, with only 1.9% quartz at a recovery of 21.5% compared to the 2.7% of quartz at a recovery of 24.9% when using SHMP. The paper contributes in general to understanding the complexity of the depressant responses in froth flotation

On the impact of grinding conditions in the flotation of semi-soluble salt-type mineral-containing ores driven by surface or particle geometry effects?

Grinding and flotation processes are often studied independently, despite the well-established grinding influence on flotation performance, which affects not only particle size and thus liberation but also shape and leads to complex changes in pulp chemistry affecting the particle surface properties relevant for selective bubble attachment. Yet, no study jointly investigated these possible causes and many are limited to single mineral flotation. We relate grinding conditions to changes in pulp chemistry and particle surface properties and assess their impact on upgrading. We studied three non-sulfide ores with different feed grades and valuables: scheelite, apatite, and fluorite. These were dry-, wet-, and wet conditioned-ground before flotation in a laboratory mechanical cell. Results were evaluated with bulk- and particle-specific methodologies. The selectivity of the process is higher after dry grinding for the fluorite and apatite ores and irrelevant for the scheelite ore. Variations in flotation kinetics of individual particles associated to their size and shape are not sufficient to explain these results. The higher concentration of Ca2+ and Mg2+ observed in the pulp after wet grinding, altering particle surface properties, better explains the phenomenon. Additionally, we demonstrate how particle shape impacts are system specific and related to both entrainment and true flotation

Characterisation of the Grain Morphology of Artificial Minerals (EnAMs) in Lithium Slags by Correlating Multi-Dimensional 2D and 3D Methods

Slags from the metallurgical recycling process are an important source of resources classified as critical elements by the EU. One example is lithium from Li-ion battery recycling. In this context, the thermodynamic properties of the recycled component system play a significant role in the formation of the Li-bearing phases in the slag, in this case, LiAlO2. LiAlO2 crystal formation could be engineered and result in varying sizes and occurrences by different metallurgical processing conditions. This study uses pure ingredients to provide a synthetic model material which can be used to generate the valuable phase in the slag, or so-called engineered artificial minerals (EnAMs). The aim is to investigate the crystallisation of LiAlO2 as an EnAM by controlling the cooling conditions of the model slag to optimise the EnAM formed during crystallisation. Characterisation of the EnAMs is an important step before further mechanically processing the material to recover the valuable element Li, the Li-bearing species, respectively. Investigations are conducted using powder X-ray diffraction (XRD), X-ray fluorescence (µXRF), and X-ray Computer Tomography (XCT) on two different artificial lithium slags from MnO-Al2O3-SiO2-CaO systems with different cooling temperature gradients. The result shows the different EnAM morphology along the height of the slag, which is formed under different slag production conditions in a semi-pilot scale experiment of 5 kg. Based on the different EnAM morphologies, three defined qualities of the EnAM are identified: granular, dendritic, and irregular-shape EnAM

Comparison of Elemental Analysis Techniques for the Characterization of Commercial Alloys

Better quality control for alloy manufacturing and sorting of post-consumer scraps relies heavily on the accurate determination of their chemical composition. In recent decades, analytical techniques, such as X-ray fluorescence spectroscopy (XRF), laser-induced breakdown spectroscopy (LIBS), and spark optical emission spectroscopy (spark-OES), found widespread use in the metal industry, though only a few studies were published about the comparison of these techniques for commercially available alloys. Hence, we conducted a study on the evaluation of four analytical techniques (energy-dispersive XRF, wavelength-dispersive XRF, LIBS, and spark-OES) for the determination of metal sample composition. It focuses on the quantitative analysis of nine commercial alloys, representing the three most important alloy classes: copper, aluminum, and steel. First, spark-OES is proven to serve as a validation technique in the use of certified alloy reference samples. Following an examination of the lateral homogeneity by XRF, the results of the techniques are compared, and reasons for deviations are discussed. Finally, a more general evaluation of each technique with its capabilities and limitations is given, taking operation-relevant parameters, such as measurement speed and calibration effort, into account. This study shall serve as a guide for the routine use of these methods in metal producing and recycling industries

Evaluation of Magnetic Separation Efficiency on a Cassiterite-Bearing Skarn Ore by Means of Integrative SEM-Based Image and XRF–XRD Data Analysis

Image analysis data obtained from scanning electron microscopy provided data for a detailed evaluation of the separation efficiency for various processes involving the beneficiation of particulate materials. A dry magnetic separation by a drum type magnetic separator served as a case study to visualize effects of processing of a skarn ore with a high content of cassiterite as ore mineral (~4 wt%). For this material, iron oxides and silicates are the main gangue mineral groups. Based on the obtained data, partition curves were generated with the help of local regression. From the partition curves, the separation efficiency was evaluated and the relevant particle properties deduced. A detailed analysis of the bias of the quantitative mineralogical data is presented. This bias was monitored and further analyzed in detail. Thorough analysis of feed and products of magnetic separation enabled identification of the most important factors that control losses of cassiterite to the magnetic product, namely the association with iron oxides and particle sizes below ~40 µm. The introduced methodology is a general approach applicable for the optimization of different separation processes and is not limited to the presented case study

Data from a pilot plant experiment for the processing of a complex tin skarn ore - 19.11.2018

This data set derives from a pilot plant campaign for the beneficiation of a complex tin bearing skarn ore, including different separation and classification steps. The aim of the pilot plant test work was to prove a flowsheet that had been developed based on detailed geometallurgical analysis and results from the research projects AFK (Aufbereitung feinkörniger Komplexerze, BMBF grant number 033R128) and FAME (European Union grant 641650) to produce a cassiterite concentrate for tin production, and further preconcentrates for iron, zinc, copper, indium, and arsenic. The tin mineralization is partially well localized in cassiterite, but also partially finely disseminated and thus unrecoverable as minor components in other minerals. The iron is located in magnetic and nonmagnetic iron oxides sometimes intergrown with cassiterite. Therefore, iron concentrates are recovered at larger grain sizes but need a further tin recovery step not implemented in the reported experiment. The other elements are mainly deported in sulfides, which are bulk recovered in a flotation step. A subsequent selective flotation is needed to recover them individually. This selective flotation is, however, not part of the reported experiment. The two tin concentrates recovered from the shaking table should be considered as preconcentrates, that can be enriched further e.g. through multi-stage gravity separation. The motivation for this data set is to provide a consistent basis for the application of new particle based geometallurgical methods enabled by automated mineralogy (e.g. Buchmann et al. 2018; Schach et al. 2019; Buchmann et al. 2020; Pereira et al. 2020). In addition, it should also allow for the comparison and evaluation of different analytical methods, which were used during the pilot plant experiments to generate a validated data set for the whole plant and to correlate different result from various methods. This is the basis for further investigations enabling the application of various analyzing methods in a synergetic way. Those synergies can help in the future to compensate drawbacks of certain methods by an adequate combination of multiple approaches. This repository includes raw data and processed data from November 19, 2018. The following data is included: X-ray fluorescence spectroscopy (XRF) X-ray diffraction (XRD) Automated Mineralogy (MLA) The balanced mass flows and element/mineral grades for the XRF- and the MLA data External certified analysis including different inductive coupled plasma (ICP) and XRF methods from ALS R scripts for the mass balance Please find further information in the "supplementary information" fil