69 research outputs found
Strong effect of stress on the seismic signature of the post-stishovite phase transition in the Earth’s lower mantle
The stishovite to post-stishovite phase transition may modify the scattering of seismic waves by stishovite-bearing rocks in the Earth's lower mantle. A series of continuous compression experiments on sintered polycrystalline stishovite was performed to study the effect of stress on the phase transition. The experimental results show that the phase transition shifts to lower pressures as the magnitude of deviatoric stress increases. Our results further show that the bulk modulus of sintered polycrystalline stishovite differs from that derived from single crystal measurements and decreases at the phase transition. In cold regions, such as subducted slabs, stresses may accumulate and shift the phase transition to a shallower depth. In hot regions with less stress, such as rising plumes, the phase transition is shifted to a greater depth. In addition, the phase transition may have varying seismic signatures depending on the behavior of the grain boundaries in mantle rocks and the micro-stresses present in neighboring grains
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Digitalizing the Chemical Landscape: A Comprehensive Overview and Progress Report of NFDI4Chem
The Chemistry consortium NFDI4Chem aims to digitalise key steps in chemical research, supporting scientists in managing research data throughout its life cycle. The SmartLab, embedded in a federation of services, integrates various tools such as electronic lab notebooks, data repositories, and search services, to create a smart lab environment for structured data gathering. Utilizing terminology services and adhering to data format standards, NFDI4Chem promotes secure and FAIR data sharing, fostering collaboration and expediting scientific discoveries. This development is supported by community building measures, workshops, and training initiatives, along with collaboration on international minimum information standards
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NFDI4Chem - A Research Data Network for International Chemistry
Research data provide evidence for the validation of scientific hypotheses in most areas of science. Open access to them is the basis for true peer review of scientific results and publications. Hence, research data are at the heart of the scientific method as a whole. The value of openly sharing research data has by now been recognized by scientists, funders and politicians. Today, new research results are increasingly obtained by drawing on existing data. Many organisations such as the Research Data Alliance (RDA), the goFAIR initiative, and not least IUPAC are supporting and promoting the collection and curation of research data. One of the remaining challenges is to find matching data sets, to understand them and to reuse them for your own purpose. As a consequence, we urgently need better research data management
CT differentiation of enlarged mediastinal lymph node due to anthracosis from metastatic lymphadenopathy: a comparative study proven by endobronchial US-guided transbronchial needle aspiration
PURPOSEAnthracosis often results in mediastinal nodal enlargement. The aim of this comparative study was to evaluate if it is possible to differentiate endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) proven anthracotic lymph nodes from malignant lymph node enlargement by means of multislice computed tomography (MSCT).METHODSWe compared the MSCT findings of 89 enlarged lymph nodes due to anthracosis with 54 malignant lymph nodes (non-small cell lung cancer 75.9%, small cell lung cancer 18.5%, and non-Hodgkin lymphoma 5.6%). The lymph nodes were assessed for density (calcification, fat, and necrosis), shape (oval, round), contrast enhancement, and contour (sharp, ill-defined).RESULTSMalignant lymph nodes showed significantly greater axis diameters (P < 0.001). Both anthracotic and malignant nodes were most often oval (86.5% of all malignant nodes vs. 81.5% of all anthracotic nodes, P = 0.420) and showed confluence in a remarkable percentage (28.1% vs. 42.6%, P = 0.075). Anthracotic nodes showed calcifications more often (18% vs. 0%, P < 0.001). Malignant lymph nodes showed a significantly greater short and long axis diameter (P < 0.001), and they had a higher frequency of ill-defined contours (27.8% vs. 2.2%, P < 0.001) and contrast enhancement (27.8% vs. 5.6%, P < 0.001). Nodal necrosis, which appeared in one third of the malignant nodes, was not observed in anthracosis (35.2% vs. 0%, P < 0.001). Confluence of enlarged lymph nodes was seen in malignant lymph nodes (42.6%), as well as in lymph node enlargement due to anthracosis (28.1%, P = 0.075).CONCLUSIONOur results show that there are significant differences in MSCT findings of malignant enlarged lymph nodes and benign lymph node enlargement due to anthracosis
Interim Report NFDI4Chem 2023
The progress of the DFG-funded NFDI4Chem consortium (NFDI 4/1 - project number 441958208) in data management in chemistry is outlined in our latest report, highlighting the steps we have taken to integrate a data-centric approach within the chemistry community. This interim report offers a comprehensive overview of our data management activities, covering the reporting period from October 2020 to August 2023.The shift to digital tools in research documentation is driven by our work with Electronic Laboratory Notebooks (ELNs), such as Chemotion ELN, offering systematic data storage for easy retrieval and sharing. Additionally, we focus on developing repositories, such as Chemotion repository and RADAR4Chem, which fulfil the needs for the storage of chemical data. The NFDI4Chem Search Service ensures easy data access from our repositories. Our efforts extend to community engagement through conference visits and online presence, aimed at creating awareness for (digital) research data management and connecting to chemistry students and researchers. Our training programs have reached over 600 participants to date. Initiatives like the FAIR4Chem award and the Chemistry Data Days promote cultural change towards FAIR data. Our Editors4Chem initiative collaborates with publishers for standardised data management and the Ontologies4Chem workshops organised by our consortium promote the ontology development in the field.Apart from the consortium's engagement for chemists, NFDI4Chem members played key roles in the development of the NFDI as a whole. Being actively involved in the sections and task forces, NFDI4Chem promotes collaborative solutions across NFDI consortia
Synthesis of lamellarin u and lamellarin g trimethyl ether by alkylation Of a deprotonated alpha-aminonitrile
1,2,3,4-Tetrahydroisoquinoline-1-carbonitriles can serve as starting materials for the one-pot synthesis of 5,6-dihydropyrrolo[2,1a]isoquinolines and 1-benzyl-3,4-dihydroisoquinolines. The latter compounds were transformed to lamellarin G trimethyl ether and lamellarin U in short reaction sequences. This method allows the introduction of acid-sensitive protecting groups for the phenolic hydroxy functions which would be cleaved under the harsh conditions of the classical Bischler-Napieralski reaction
Ganodermycin, a novel inhibitor of cxcl10 expression from ganoderma applanatum
CXCL10 (inducible protein-10) is a highly inducible chemoattractant, which contributes to the recruitment of inflammatory cells, such as macrophages and T-lymphocytes, and thereby has important roles in chronic inflammatory conditions. In a search for new inhibitors of CXCL10 expression in MonoMac6 cells, a novel compound, designated as Ganodermycin, was isolated from fermentations of the basidiomycete Ganoderma applanatum. The structure was determined by a combination of spectroscopic techniques. Ganodermycin inhibited the lipopolysaccharide (LPS)/interferon (IFN)-gamma-induced CXCL10 promoter activity in transiently transfected MonoMac6 cells in a dose-dependent manner with IC(50) values of 15-20 mu g ml(-1) (53-71 mu M). Ganodermycin also reduced LPS/IFN-gamma-induced CXCL10 protein synthesis and excretion. The Journal of Antibiotics (2011) 64, 683-686; doi:10.1038/ja.2011.64; published online 27 July 201
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