39 research outputs found
DNP Enhanced Frequency-Selective TEDOR Experiments in Bacteriorhodopsin
We describe a new approach to multiple [superscript 13]C–[superscript 15]N distance measurements in uniformly labeled solids, frequency-selective (FS) TEDOR. The method shares features with FS-REDOR and ZF- and BASE-TEDOR, which also provide quantitative [superscript 15]N–[superscript 13]C spectral assignments and distance measurements in U-[[superscript 13]C,[superscript 15]N] samples. To demonstrate the validity of the FS-TEDOR sequence, we measured distances in [U-[superscript 13]C,15N]-asparagine which are in good agreement with other methods. In addition, we integrate high frequency dynamic nuclear polarization (DNP) into the experimental protocol and use FS-TEDOR to record a resolved correlation spectrum of the Arg-[superscript 13]Cγ–[superscript 15]Nε region in [U-[superscript 13]C,15N]-bacteriorhodopsin. We resolve six of the seven cross-peaks expected based on the primary sequence of this membrane protein.National Institute of Biomedical Imaging and Bioengineering (U.S.) (Grant Number EB-001960)National Institute of Biomedical Imaging and Bioengineering (U.S.) (Grant Number EB-002804)National Institute of Biomedical Imaging and Bioengineering (U.S.) (Grant Number EB-001035)National Institute of Biomedical Imaging and Bioengineering (U.S.) (Grant Number EB-002026
A benzene-degrading nitrate-reducing microbial consortium displays aerobic and anaerobic benzene degradation pathways
All sequence data from this study were deposited at the European Bioinformatics Institute under the accession numbers ERS1670018 to ERS1670023. Further, all assigned genes, taxonomy, function, sequences of contigs, genes and proteins can be found in Table S3.In this study, we report transcription of genes involved in aerobic and anaerobic benzene degradation pathways in a benzene-degrading denitrifying continuous culture. Transcripts associated with the family Peptococcaceae dominated all samples (2136% relative abundance) indicating their key role in the community. We found a highly transcribed gene cluster encoding a presumed anaerobic benzene carboxylase (AbcA and AbcD) and a benzoate-coenzyme A ligase (BzlA). Predicted gene products showed >96% amino acid identity and similar gene order to the corresponding benzene degradation gene cluster described previously, providing further evidence for anaerobic benzene activation via carboxylation. For subsequent benzoyl-CoA dearomatization, bam-like genes analogous to the ones found in other strict anaerobes were transcribed, whereas gene transcripts involved in downstream benzoyl-CoA degradation were mostly analogous to the ones described in facultative anaerobes. The concurrent transcription of genes encoding enzymes involved in oxygenase-mediated aerobic benzene degradation suggested oxygen presence in the culture, possibly formed via a recently identified nitric oxide dismutase (Nod). Although we were unable to detect transcription of Nod-encoding genes, addition of nitrite and formate to the continuous culture showed indication for oxygen production. Such an oxygen production would enable aerobic microbes to thrive in oxygen-depleted and nitrate-containing subsurface environments contaminated with hydrocarbons.This study was supported by a grant of BE-Basic-FES funds from the Dutch Ministry of Economic Affairs. The research of A.J.M. Stams is supported by an ERC grant (project 323009) and the gravitation grant “Microbes for Health and Environment” (project 024.002.002) of the Netherlands Ministry of Education, Culture and Science. F. Hugenholtz was supported by the same gravitation grant (project 024.002.002). B. Hornung is supported by Wageningen University and the Wageningen Institute for Environment and Climate Research (WIMEK) through the IP/OP program Systems Biology (project KB-17-003.02-023).info:eu-repo/semantics/publishedVersio
Beiträge zum 28. Darmstädter Geotechnik-Kolloquium am 09. März 2022
Themenschwerpunkte:
1. Modell- und Feldversuche
2. Digitalisierung und künstliche Intelligenz in der Geotechnik
3. Nationale und internationale Großprojekte
4. Normung und Rechtliche
Beiträge zum 28. Darmstädter Geotechnik-Kolloquium am 09. März 2022
Themenschwerpunkte:
1. Modell- und Feldversuche
2. Digitalisierung und künstliche Intelligenz in der Geotechnik
3. Nationale und internationale Großprojekte
4. Normung und Rechtliche
Genetics ignite focus on microglial inflammation in Alzheimer’s disease
In the past five years, a series of large-scale genetic studies have revealed novel risk factors for Alzheimer’s disease (AD). Analyses of these risk factors have focused attention upon the role of immune processes in AD, specifically microglial function. In this review, we discuss interpretation of genetic studies. We then focus upon six genes implicated by AD genetics that impact microglial function: TREM2, CD33, CR1, ABCA7, SHIP1, and APOE. We review the literature regarding the biological functions of these six proteins and their putative role in AD pathogenesis. We then present a model for how these factors may interact to modulate microglial function in AD
Direct estimation of the wall shear rate using parametric motion models in 3D
Abstract We present a new optical-flow-based technique to estimate the wall shear rate using a special illumination technique that makes the brightness of particles dependent on the distance from the wall. The wall shear rate is derived directly (that means, without previous calculation of the velocity vector field) from two of the components of the velocity gradient tensor which in turn describes the kinematics of fluid flows up to the first order. By incorporating this into a total least squares framework, we can apply a further extension of the structure tensor technique. Results obtained both from synthetical and real data are shown, and reveal a substantial improvement compared to conventional techniques.
On-line state estimation of automotive batteries using in-situ impedance spectroscopy
Safe operation of Li-ion traction batteries in electric cars is one of the main requirements for a broad acceptance of this technology. Safety critical factors such as over-temperature conditions must be reliably monitored and captured. Increasingly strict safety regulations in the automotive sector imply rising challenges to both car manufacturers and battery system suppliers and hence resilient, reliable yet inexpensive tools for battery state diagnosis are necessary to address these topics. The approach presented here is a battery diagnosis tool based on in-situ galvanostatic electrochemical impedance spectroscopy which can be integrated into a standard battery management system. The algorithms which are used to convert the impedance measurements into valuable battery temperature estimations are based on numeric correlations between the impedance and these state variables. It is shown that the method can be used even in non-equilibrium state of the battery thus improving the functional safety in electric cars during the usage of a battery pack by redundant monitoring of the battery temperature