Publications by authors named "Lehmann M"

Lubrication is a critical aspect of the metal forming process and it is strongly influenced by the surface texture of the tool-forming surfaces. This study is focused on determining the effect of surface finish and heat treatment on wettability involving commonly used lubrication agents. Three different finishing states are evaluated (as-ground, as-polished and as-nitrided).

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Transfusion of platelet concentrates (PC) can be a life-saving measure in case of severe thrombocytopenia or thrombocytopathy, particularly in bleeding patients. Although acaryote, platelets are involved in several important functions including immunomodulation, but their most important function is in primary and secondary haemostasis. In this German review, apheresis and whole blood derived PC are compared and indications as well as transfusion triggers and dosage of PC are discussed.

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Cross-linking mass spectrometry (XL-MS) enables the mapping of protein-protein interactions on the cellular level. When applied to all compartments of mitochondria, the sheer number of cross-links and connections can be overwhelming, rendering simple cluster analyses convoluted and uninformative. To address this limitation, we integrate the XL-MS data, 3D electron microscopy data, and localization annotations with a supra coarse-grained molecular dynamics simulation to sort all data, making clusters more accessible and interpretable.

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Rationale: Determining several isotope ratios in one analysis multiplies the information that can be retrieved from a sample in a cost-efficient way. The stable isotope ratios of hydrogen (δH), carbon (δC), and oxygen (δO) in organic compounds are highly relevant due to their complimentary hydroclimatic and physiological signals. Different types of organic material reflect different processes and integration times, like short term in leaf sugars and long term in tree ring cellulose, but currently, no simple method exists for their triple isotope analysis.

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Article Synopsis
  • Live-cell imaging of cholesterol trafficking requires suitable fluorescent cholesterol analogs, but current options have significant drawbacks, such as differing properties or requiring UV excitation.
  • The study introduces two new fluorescent sterol probes that resemble cholesterol closely, enhancing their applicability for imaging.
  • One probe features visible emissions suitable for conventional microscopy, while the other proves unstable and unusable, making the first a better choice for studying sterol transport in live cells.*
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The urgent need for effective treatments for acute and chronic lung diseases underscores the significance of developing innovative preclinical human research tools. The 2023 ATS Workshop on Precision Cut Lung Slices (PCLS) brought together 35 experts to discuss and address the role of human tissue-derived PCLS as a unique tool for target and drug discovery and validation in pulmonary medicine. With increasing interest and usage, along with advancements in methods and technology, there is a growing need for consensus on PCLS methodology and readouts.

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Flavonoids represent a diverse group of plant specialised metabolites which are also discussed in the context of dietary health and inflammatory response. Numerous studies have revealed that flavonoids play a central role in plant acclimation to abiotic factors like low temperature or high light, but their structural and functional diversity frequently prevents a detailed mechanistic understanding. Further complexity in analysing flavonoid metabolism arises from the different subcellular compartments which are involved in biosynthesis and storage.

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The perturbation of the reference wave due to electric stray fields represents a major challenge in quantitative electron holographic investigations. By introducing a focused-ion-beam-milled rectangular hole, the reference window, in an area of nearly constant electrostatic potential of the sample, this perturbation can be significantly reduced. The edge of the window forms a closed conducting loop, acting similarly to a Faraday cage, shielding the influence of the stray field on the reference wave to some extent.

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Background And Objective: Metastatic urothelial carcinoma (mUCa) ranks as the costliest cancer to treat per patient due to frequent interventions and expensive follow-ups. Investigating first-line therapies, combinations such as enfortumab vedotin + pembrolizumab (EV + P) and gemcitabine/cisplatin + nivolumab exhibit significant overall survival benefits compared with the standard treatment (SoC; gemcitabine/cisplatin). Here, we conducted a cost-effectiveness analysis for mUCa.

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The global nitrogen (N) cycle has been strongly altered by anthropogenic activities, including increased input of bioavailable N into aquatic ecosystems. Freshwater sediments are hotspots with regards to the turnover and elimination of fixed N, yet the environmental controls on the microbial pathways involved in benthic N removal are not fully understood. Here, we analyze the abundance and expression of microbial genes involved in N transformations using metagenomics and -transcriptomics across sediments of 12 Swiss lakes that differ in sedimentation rates and trophic regimes.

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Thirty years ago, the Global Solar UV Index (UVI) has been introduced as a health promotion instrument to improve sun protection. We assessed systematically global levels of awareness and use of the UVI as a prerequisite for the preventive effectiveness of this public health tool. We conducted a comprehensive literature search across 10 databases, including PubMed, Scopus and Web of Science Core Collection, as well as clinical trial registries and gray literature databases.

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Communication between cells is largely orchestrated by proteins on the cell surface, which allow information transfer across the cell membrane. Super-resolution and single-molecule visualization of these proteins can be achieved by genetically grafting HTP (HaloTag Protein) into the protein of interest followed by brief incubation of cells with a dye-HTL (dye-linked HaloTag Ligand). This approach allows for use of cutting-edge fluorophores optimized for specific optical techniques or a cell-impermeable dye-HTL to selectively label surface proteins without labeling intracellular copies.

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Electron holography is a powerful tool to investigate the properties of micro- and nanostructured electronic devices. A meaningful interpretation of the holographic data, however, requires an understanding of the 3D potential distribution inside and outside the sample. Standard approaches to resolve these potential distributions involve projective tilt series and their tomographic reconstruction, in addition to extensive simulations.

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Despite considerable experimental effort, the physiological mechanisms governing temperate tree species' water and carbon dynamics before the onset of the growing period remain poorly understood. We applied H-enriched water during winter dormancy to the soil of four potted European tree species. After 8 weeks of chilling, hydrogen isotopes in stem, twig and bud water were measured six times during 2 consecutive weeks of forcing conditions (Experiment 1).

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Background: Eukaryotic cells are highly compartmentalized by a variety of organelles that carry out specific cellular processes. The position of these organelles within the cell is elaborately regulated and vital for their function. For instance, the position of lysosomes relative to the nucleus controls their degradative capacity and is altered in pathophysiological conditions.

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Arabidopsis uracil phosphoribosyltransferase (UPP) is an essential enzyme and plants lacking this enzyme are strongly compromised in chloroplast function. Our analysis of UPP amiRNA mutants has confirmed that this vital function is crucial to establish a fully functional photosynthesis as the RIESKE iron sulfur protein (PetC) is almost absent, leading to a block in photosynthetic electron transport. Interestingly, this function appears to be unrelated to nucleotide homeostasis since nucleotide levels were not altered in the studied mutants.

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Mangrove forests represent important sources of methane, partly thwarting their ecosystem function as an efficient atmospheric carbon dioxide sink. Many studies have focused on the spatial and temporal variability of methane emissions from mangrove ecosystems, yet little is known about the microbial and physical controls on the release of biogenic methane from tidally influenced mangrove sediments. Here, we show that aerobic methane oxidation is a key microbial process that effectively reduces methane emissions from mangrove sediments.

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Idiopathic pulmonary fibrosis (IPF) is a lethal chronic lung disease characterized by aberrant intercellular communication, extracellular matrix deposition, and destruction of functional lung tissue. While extracellular vesicles (EVs) accumulate in the IPF lung, their cargo and biological effects remain unclear. We interrogated the proteome of EV and non-EV fractions during pulmonary fibrosis and characterized their contribution to fibrosis.

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Chlorothalonil (CTL) is a pesticide widely used in Brazil, yet its mutagenic potential is not fully determined. Thus, we assessed the mutagenicity of CTL and its bioactivation metabolites using the somatic mutation and recombination test (SMART) in Drosophila melanogaster, by exposing individuals, with basal and high bioactivation capacities (standard and high bioactivation cross offspring, respectively), from third instar larval to early adult fly stages, to CTL-contaminated substrate (0.25, 1, 10 or 20 μM).

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Article Synopsis
  • Chronic social defeat (CSD) stress in mice leads to a significant accumulation of neutrophils in the meningeal area, while acute stress does not have the same effect.
  • The study utilizes various techniques, like cytometry and single-cell sequencing, to show that CSD increases neutrophil movement from bone marrow through vascular channels.
  • Blocking type I interferon (IFN-I) signaling can prevent negative behaviors linked to CSD stress, suggesting that targeting this pathway could help develop new treatments for stress-related disorders.
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Climate change not only leads to higher air temperatures but also increases the vapour pressure deficit (VPD) of the air. Understanding the direct effect of VPD on leaf gas exchange is crucial for precise modelling of stomatal functioning. We conducted combined leaf gas exchange and online isotope discrimination measurements on four common European tree species across a VPD range of 0.

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