Refine
Year of publication
Document Type
- Article (68)
- Postprint (4)
- Conference Proceeding (2)
- Part of Periodical (2)
- Preprint (1)
- Review (1)
Is part of the Bibliography
- yes (78)
Keywords
- Pavlovian-to-instrumental transfer (2)
- alcohol (2)
- amygdala (2)
- biomaterials (2)
- hemocompatibility (2)
- high risk drinkers (2)
- polygenic risk (2)
- yedoma (2)
- A viruses (1)
- Active Galactic Nuclei (1)
- Air showers (1)
- Alaska (1)
- Alcohol dependence (1)
- Anisotropy (1)
- BEEBOOK (1)
- BL Lacertae objects: general (1)
- BL Lacertae objects: individual: Mrk501 (1)
- BeeScan (1)
- Beringia (1)
- Bibel (1)
- Bible (1)
- Biomaterial (1)
- COLOSS (1)
- Carbon (1)
- Caudate (1)
- Cell-free (1)
- Cherenkov Telescopes (1)
- Childhood adversity (1)
- Compton and Pair Creation Telescope (1)
- Compton and pair creation telescope (1)
- Cosmic Antimatter (1)
- Cosmic Rays (1)
- Counterparts of gravitational waves (1)
- Dark Matter (1)
- Depression (1)
- Design concepts (1)
- ENIGMA (1)
- Early Universe (1)
- Energy-transfer probe (1)
- Evolutionary ecology (1)
- Exciplex (1)
- FT-ICR MS (1)
- Fermi (1)
- Fluorescence (1)
- Gamma-Ray Bursts (1)
- Gamma-ray astronomy (1)
- Ground based gamma ray astronomy (1)
- Hebrew (1)
- Hebräisch (1)
- High-Energy Astrophysics (1)
- High-Energy Gamma-Ray Astronomy (1)
- Hippocampus (1)
- Human neuroimaging (1)
- ISM: individual objects (RX J1713.7-3946, G347.3-0.5) (1)
- In vitro translation (1)
- Insect lysate (1)
- Jets (1)
- Jewish Studies (1)
- Jiddisch (1)
- Jüdische Studien (1)
- Lake sediments (1)
- Limnology (1)
- MRI (1)
- Methane (1)
- Multiwavelength Observations of the Universe (1)
- Next generation Cherenkov telescopes (1)
- Nuclear Astrophysics (1)
- Nucleosynthesis (1)
- Nucleus accumbens (1)
- Outflows (1)
- Palaeoclimate (1)
- Pavlovian-instrumental transfer (1)
- Permafrost (1)
- Platelet (1)
- RFID (1)
- Relapse (1)
- Single chain antibody (scFv) (1)
- Supernovae (1)
- Surface plasmon resonance (1)
- Talik (1)
- TeV gamma-ray astronomy (1)
- Temperature sensitivity (1)
- Tendurek volcano (1)
- TerraSAR-X (1)
- TiO2 nanotubes (1)
- Translations (1)
- Volcan de Colima (1)
- X-rays: binaries (1)
- Yiddish (1)
- acceleration of particles (1)
- actin cytoskeleton (1)
- appetitive learning (1)
- arcuate fracture system (1)
- aryl diazonium salts (1)
- associative learning (1)
- astroparticle physics (1)
- aversive learning (1)
- avian influenza (1)
- behaviour (1)
- bioindicators (1)
- biosensor (1)
- caldera subsidence (1)
- carabid beetles (1)
- carbon (1)
- cardiovascular disease (1)
- cardiovascular implant (1)
- cell adhesion (1)
- chronic stress (1)
- cognitive speed (1)
- conifer plantations (1)
- cosmic rays (1)
- cryostratigraphy (1)
- cys-peptide (1)
- decision making (1)
- diazonium coupling (1)
- distribution patterns (1)
- electromagnetic field enhancement (1)
- entry (1)
- environmental-factors (1)
- fault reactivation (1)
- fibrinogen (1)
- fibroblast (1)
- finite element modeling (1)
- focal adhesion (1)
- forest management intensity (1)
- free-flying honey bees (1)
- gamma rays: ISM (1)
- gamma-ray polarization (1)
- gustatory responsiveness (1)
- harmonic radar (1)
- high-energy astrophysical phenomena (1)
- honey bee (1)
- honey bee dance (1)
- honey bee flight (1)
- honey bee mating (1)
- honey bee navigation (1)
- human Pavlovian-to-instrumental transfer (1)
- identification (1)
- invection (1)
- lava dome (1)
- lichen Lobaria pulmonaria (1)
- load stress (1)
- locomotion (1)
- mAb (1)
- maleimidophenyl (1)
- microbes (1)
- model-based learning (1)
- model-free learning (1)
- neuraminidase (1)
- neutralizing antibody (1)
- non-associative learning (1)
- nucleus accumbens (1)
- observation hive (1)
- olfactory responsiveness (1)
- origin (1)
- oxygen plasma (1)
- palaeoenvironmental reconstruction (1)
- past land-use (1)
- permafrost (1)
- photogrammetry (1)
- photonic crystals (1)
- phototaxis (1)
- plant diversity (1)
- platelet aging (1)
- platelet function (1)
- platelet rich plasma (1)
- platelet storage (1)
- platelets (1)
- poly(n-butyl acrylate) (1)
- population-genetics (1)
- radiation mechanisms: non-thermal (1)
- real-life events (1)
- receptor-binding (1)
- relapse in alcohol use disorder (1)
- sites (1)
- space mission (1)
- species composition (1)
- spectro-electrochemistry (1)
- surface plasmon resonance (1)
- surface-enhanced Raman spectroscopy (1)
- temperature sensing (1)
- tephra (1)
- thermokarst lake dynamics (1)
- time-domain astronomy (1)
- viability (1)
- whole blood (1)
- Übersetzungen (1)
Institute
- Institut für Biochemie und Biologie (39)
- Institut für Physik und Astronomie (10)
- Institut für Chemie (9)
- Institut für Geowissenschaften (6)
- Department Sport- und Gesundheitswissenschaften (4)
- Department Psychologie (2)
- Mathematisch-Naturwissenschaftliche Fakultät (2)
- Strukturbereich Kognitionswissenschaften (2)
- Vereinigung für Jüdische Studien e. V. (2)
- Extern (1)
The development of an electrochemical piezoelectric sensor for the detection of glycated hemoglobin is presented. The total hemoglobin (Hb) content is monitored with a mass-sensitive quartz crystal modified with surfactants, and the glycated fraction of the immobilized Hb is determined by subsequent voltarnmetric measurement of the coupled ferroceneboronic acid. Different modifications of the sensor were tested for their hemoglobin binding ability. Deoxycholate (DOCA) was found to be the most suitable among the examined modifiers. Piezoelectric quartz crystals with gold electrodes were modified with DOCA by covalent binding to a pre-formatted 4-aminothiophenol monolayer. The properties of the Hb binding to DOCA and the pH effect on this interaction were studied. In the proposed assay for glycated hemoglobin at first an Hb sample is incubated with ferroceneboronic acid (FcBA), which binds to the fructosyl residue of the glycated Hb. Then this preincubated Hb sample is allowed to interact with the DOCA-modified piezoelectric quartz crystal. The binding is monitored by quartz crystal nanobalance QCN). The amount of FcBA present on the sensor surface is determined by square wave voltammetry. The binding of FcBA results in well-defined peaks with an EO' of +200 mV versus Ag/AgC1 (1 M KC1). The peak height depends on the degree of glycated Hb in the sample ranging from 0% to 20% of total Hb. The regeneration of the sensing surface is achieved by pepsin digestion of the deposited Hb. Thus the sensor can be re-used more than 30 times.
A novel electrochemical immunoassay based on the multiple affinity labeling of the indicator antibody with an electro-active tag is presented. The concept is illustrated for the determination of the glycated hemoglobin HbA1c in hemoglobin samples. Hemoglobin is adsorbed to the surfactant-modified surface of a piezoelectric quartz crystal. Whereas the quartz crystal nanobalance is used to validate the total Hb binding, the HbA1c on the sensor surface is recognized by an antibody and quantified electrochemically after the sugar moieties of the antibody have been labeled in-situ with ferroceneboronic acid. The sensitivity of this sensor is about threefold higher than the sensitivity of a hemoglobin sensor, where the ferroceneboronic acid is bound directly to HbA1c.
For in vitro studies assessing the interaction of platelets with implant materials, common and standardized protocols for the preparation of platelet rich plasma (PRP) are lacking, which may lead to non-matching results due to the diversity of applied protocols. Particularly, the aging of platelets during prolonged preparation and storage times is discussed to lead to an underestimation of the material thrombogenicity. Here, we study the influence of whole blood-and PRP-storage times on changes in platelet morphology and function.
Whole blood PFA100 closure times increased after stimulation with collagen/ADP and collagen/epinephrine. Twenty four hours after blood collection, both parameters were prolonged pathologically above the upper limit of the reference range. Numbers of circulating platelets, measured in PRP, decreased after four hours, but no longer after twenty four hours. Mean platelet volumes (MPV) and platelet large cell ratios (P-LCR, 12 fL - 40 fL) decreased over time. Immediately after blood collection, no debris or platelet aggregates could be visualized microscopically. After four hours, first debris and very small aggregates occurred. After 24 hours, platelet aggregates and also debris progressively increased. In accordance to this, the CASY system revealed an increase of platelet aggregates (up to 90 mu m diameter)with increasing storage time.
The percentage of CD62P positive platelets and PF4 increased significantly with storage time in resting PRP. When soluble ADP was added to stored PRP samples, the number of activatable platelets decreased significantly over storage time. The present study reveals the importance of a consequent standardization in the preparation of WB and PRP. Platelet morphology and function, particularly platelet reactivity to adherent or soluble agonists in their surrounding milieu, changed rapidly outside the vascular system. This knowledge is of crucial interest, particularly in the field of biomaterial development for cardiovascular applications, and may help to define common standards in the in vitro hemocompatibility testing of biomaterials.
Dust has the potential to modify global climate by influencing the radiative balance of the atmosphere and by supplying iron and other essential limiting micronutrients to the ocean(1,2). Indeed, dust supply to the Southern Ocean increases during ice ages, and 'iron fertilization' of the subantarctic zone may have contributed up to 40 parts per million by volume (p. p. m. v.) of the decrease (80-100 p. p. m. v.) in atmospheric carbon dioxide observed during late Pleistocene glacial cycles(3-7). So far, however, the magnitude of Southern Ocean dust deposition in earlier times and its role in the development and evolution of Pleistocene glacial cycles have remained unclear. Here we report a high-resolution record of dust and iron supply to the Southern Ocean over the past four million years, derived from the analysis of marine sediments from ODP Site 1090, located in the Atlantic sector of the subantarctic zone. The close correspondence of our dust and iron deposition records with Antarctic ice core reconstructions of dust flux covering the past 800,000 years (refs 8, 9) indicates that both of these archives record large-scale deposition changes that should apply to most of the Southern Ocean, validating previous interpretations of the ice core data. The extension of the record beyond the interval covered by the Antarctic ice cores reveals that, in contrast to the relatively gradual intensification of glacial cycles over the past three million years, Southern Ocean dust and iron flux rose sharply at the Mid-Pleistocene climatic transition around 1.25 million years ago. This finding complements previous observations over late Pleistocene glacial cycles(5,8,9), providing new evidence of a tight connection between high dust input to the Southern Ocean and the emergence of the deep glaciations that characterize the past one million years of Earth history.
Although genetic diversity is one of the key components of biodiversity, its drivers are still not fully understood. While it is known that genetic diversity is affected both by environmental parameters as well as habitat history, these factors are not often tested together. Therefore, we analyzed 14 microsatellite loci in Abax parallelepipedus, a flightless, forest dwelling ground beetle, from 88 plots in two study regions in Germany. We modeled the effects of historical and environmental variables on allelic richness, and found for one of the regions, the Schorfheide-Chorin, a significant effect of the depth of the litter layer, which is a main component of habitat quality, and of the sampling effort, which serves as an inverse proxy for local population size. For the other region, the Schwabische Alb, none of the potential drivers showed a significant effect on allelic richness. We conclude that the genetic diversity in our study species is being driven by current local population sizes via environmental variables and not by historical processes in the studied regions. This is also supported by lack of genetic differentiation between local populations sampled from ancient and from recent woodlands. We suggest that the potential effects of former fragmentation and recolonization processes have been mitigated by the large and stable local populations of Abax parallelepipedus in combination with the proximity of the ancient and recent woodlands in the studied landscapes.
Abstract
Although genetic diversity is one of the key components of biodiversity, its drivers are still not fully understood. While it is known that genetic diversity is affected both by environmental parameters as well as habitat history, these factors are not often tested together. Therefore, we analyzed 14 microsatellite loci in Abax parallelepipedus, a flightless, forest dwelling ground beetle, from 88 plots in two study regions in Germany. We modeled the effects of historical and environmental variables on allelic richness, and found for one of the regions, the Schorfheide-Chorin, a significant effect of the depth of the litter layer, which is a main component of habitat quality, and of the sampling effort, which serves as an inverse proxy for local population size. For the other region, the Schwabische Alb, none of the potential drivers showed a significant effect on allelic richness. We conclude that the genetic diversity in our study species is being driven by current local population sizes via environmental variables and not by historical processes in the studied regions. This is also supported by lack of genetic differentiation between local populations sampled from ancient and from recent woodlands. We suggest that the potential effects of former fragmentation and recolonization processes have been mitigated by the large and stable local populations of Abax parallelepipedus in combination with the proximity of the ancient and recent woodlands in the studied landscapes.
We report on deep multi-color imaging (R5sigma = 26) of the Chandra Deep Field South, obtained with the Wide Field Imager (WFI) at the MPG/ESO 2.2 m telescope on La Silla as part of the multi-color survey COMBO-17. As a result we present a catalogue of 63 501 objects in a field measuring 31farcm5 x 30arcmin with astrometry and BVR photometry. A sample of 37 variable objects is selected from two-epoch photometry. We try to give interpretations based on color and variation amplitude.
Bright or dark immune complexes of anti-TAMRA antibodies for adapted fluorescence-based bioanalysis
(2015)
Fluorescence labels, for example fluorescein or rhodamin derivatives, are widely used in bioanalysis applications including lateral-flow assays, PCR, and fluorescence microscopy. Depending on the layout of the particular application, fluorescence quenching or enhancement may be desired as the detection principle. Especially for multiplexed applications or high-brightness requirements, a tunable fluorescence probe can be beneficial. The alterations in the photophysics of rhodamine derivatives upon binding to two different anti-TAMRA antibodies were investigated by absorption and fluorescence-spectroscopy techniques, especially determining the fluorescence decay time and steady-state and time-resolved fluorescence anisotropy. Two monoclonal anti-TAMRA antibodies were generated by the hybridoma technique. Although surface-plasmon-resonance measurements clearly proved the high affinity of both antibodies towards 5-TAMRA, the observed effects on the fluorescence of rhodamine derivatives were very different. Depending on the anti-TAMRA antibody either a strong fluorescence quenching (G71-DC7) or a distinct fluorescence enhancement (G71-BE11) upon formation of the immune complex was observed. Additional rhodamine derivatives were used to gain further information on the binding interaction. The data reveal that such haptens as 5-TAMRA could generate different paratopes with equal binding affinities but different binding interactions, which provide the opportunity to adapt bioanalysis methods including immunoassays for optimized detection principles for the same hapten depending on the specific requirements.
A recombinant single chain antibody fragment (designated scDE1) of the murine monoclonal anti-fluorescein antibody B13-DE1 was generated using the original hybridoma cells as source for the variable antibody heavy and light chain (VH and VL) genes. After cloning the variable genes into a phage vector a functional antibody fragment was selected by phage display panning. Recombinant antibody could be expressed as phage antibody and as soluble single chain antibody in Escherichia coli. High yield of scDE1 could also be detected in bacterial culture supernatant. The scDE1 showed the same binding specificity as the parental monoclonal antibody, i.e. it bound fluorescein, fluorescein derivatives and a fluorescein peptide mimotope. Surface plasmon resonance revealed a K(D) of 19 nM for the scDE1 compared to 0.7 nM for the monoclonal antibody. The isolated soluble scDE1 could easily be conjugated to horseradish peroxidase which allowed the use of the conjugate as universal indicator for the detection of fluorescein-labelled proteins in different immunoassays. Detection of hCG in urine was performed as a model system using scDE1. In addition to E. coli the scFv genes could also be transferred and expressed in eukaryotic cells. Finally, we generated HEK293 cells expressing the scDE1 at the cell surface.