43 research outputs found
Systematic studies on the determination of Hg-labelled proteins using laser ablation-ICPMS and isotope dilution analysis
A method was developed for the precise and accurate determination of ovalbumin labelled with p-hydroxy-mercuribenzoic acid (pHMB) using polyacrylamide gel electrophoresis with ns-laser ablation-inductively coupled plasma mass spectrometry. Following systematic optimisation of the ablation process in terms of detection sensitivity, two different quantification strategies were applied: external calibration using standards of the derivatized protein after 13C+ normalization and, as a proof of concept, label-specific isotope dilution analysis (IDA) using pHMB enriched in the isotope 199Hg. Due to the inhomogeneous distribution of the protein within the gel bands, it could be demonstrated that the IDA approach was superior in terms of precision and accuracy. Furthermore, it permits a reliable quantification, if more complex separation protocols are applied, as typically occurring analyte loss and degradation can be compensated for as soon as complete mixture of spike and sample is achieved. The estimated limit of detection was 160fmol in the case of ovalbumin. In contrast to earlier studies using metals naturally present in proteins, no loss of mercury was observed during separation under denaturing conditions and other sample preparation steps. Using label-specific IDA, the measured isotope ratios in the gel corresponded to recoveries between 95% and 103
Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.
Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field
On Ancient Grammars of Space. Linguistic Research on the Expression of Spatial Relations and Motion in Ancient Languages
This volume presents new research by the Topoi group "The Conception of Spaces in Language" on the expression of spatial relations in ancient languages. The six articles in this volume discuss static and dynamic aspects of the spatial grammars of Ancient to Medieval Greek, Akkadian, Hittite, and Hieroglyphic Ancient Egyptian, as well as field data on eight modern languages (Arabic, Hebrew, English, German, Russian, French, Italian, and Spanish). Among the grams discussed are spatial particles, motion verbs, case and, most prominently, spatial prepositions. All ancient language data are fully explained in linguistic word-by-word glosses and are therefore accessible to scholars who are not themselves experts on the respective languages. Taken together, these contributions extend the scope of research on spatial grammar back to the third millennium BCE
Systematic studies on the determination of Hg-labelled proteins using laser ablation-ICPMS and isotope dilution analysis
ISSN:1618-2650ISSN:1618-264
Quantifying cobalt in doping control urine samples - a pilot study
Since first reports on the impact of metals such as manganese and cobalt on erythropoiesis were published in the late 1920s, cobaltous chloride became a viable though not widespread means for the treatment of anaemic conditions. Today, its use is de facto eliminated from clinical practice; however, its (mis)use in human as well as animal sport as an erythropoiesis-stimulating agent has been discussed frequently. In order to assess possible analytical options and to provide relevant information on the prevalence of cobalt use/misuse among athletes, urinary cobalt concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS) from four groups of subjects. The cohorts consisted of (1) a reference population with specimens of 100 non-elite athletes (not being part of the doping control system), (2) a total of 96 doping control samples from endurance sport athletes, (3) elimination study urine samples collected from six individuals having ingested cobaltous chloride (500 mu g/day) through dietary supplements, and (4) samples from people supplementing vitamin B-12 (cobalamin) at 500 mu g/day, accounting for approximately 22 mu g of cobalt. The obtained results demonstrated that urinary cobalt concentrations of the reference population as well as the group of elite athletes were within normal ranges (0.1-2.2ng/mL). A modest but significant difference between these two groups was observed (Wilcoxon rank sum test, p22ng/mL) up to 33h. Oral supplementation of 500 mu g of cobalamin did not result in urinary cobalt concentrations>2ng/mL. Based on these pilot study data it is concluded that measuring the urinary concentration of cobalt can provide information indicating the use of cobaltous chloride by athletes. Additional studies are however required to elucidate further factors potentially influencing urinary cobalt levels. Copyright (c) 2014 John Wiley & Sons, Ltd
ICN Research Challenges
draft-kutscher-icnrg-challenges-01This memo describes research challenges for Information-Centric Networking. Information-centric networking is an approach to evolve the Internet infrastructure to directly support this use by introducing uniquely named data as a core Internet principle. Data becomes independent from location, application, storage, and means of transportation, enabling in-network caching and replication. Challenges include naming, security, routing, system scalability, mobility management, wireless networking, transport services, in- network caching, and network management