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  • MDPI AG  (11)
  • 1
    Online Resource
    Online Resource
    Quantitative Long-Term Monitoring of the Circulating Gases in the KATRIN Experiment Using Raman Spectroscopy
    MDPI AG ; 2020
    In:  Sensors Vol. 20, No. 17 ( 2020-08-26), p. 4827-
    Details
    In: Sensors, MDPI AG, Vol. 20, No. 17 ( 2020-08-26), p. 4827-
    Abstract: The Karlsruhe Tritium Neutrino (KATRIN) experiment aims at measuring the effective electron neutrino mass with a sensitivity of 0.2 eV/c2, i.e., improving on previous measurements by an order of magnitude. Neutrino mass data taking with KATRIN commenced in early 2019, and after only a few weeks of data recording, analysis of these data showed the success of KATRIN, improving on the known neutrino mass limit by a factor of about two. This success very much could be ascribed to the fact that most of the system components met, or even surpassed, the required specifications during long-term operation. Here, we report on the performance of the laser Raman (LARA) monitoring system which provides continuous high-precision information on the gas composition injected into the experiment’s windowless gaseous tritium source (WGTS), specifically on its isotopic purity of tritium—one of the key parameters required in the derivation of the electron neutrino mass. The concentrations cx for all six hydrogen isotopologues were monitored simultaneously, with a measurement precision for individual components of the order 10−3 or better throughout the complete KATRIN data taking campaigns to date. From these, the tritium purity, εT, is derived with precision of 〈 10−3 and trueness of 〈 3 × 10−3, being within and surpassing the actual requirements for KATRIN, respectively.
    Type of Medium: Online Resource
    ISSN: 1424-8220
    URL: Article
    DOI: 10.3390/s20174827
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2052857-7
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  • 2
    Online Resource
    Online Resource
    Talent Identification in Football: Different Effects of Maturation on Sprinting, Change of Direction and Jumping in 13-Year-Old Players
    MDPI AG ; 2024
    In:  Applied Sciences Vol. 14, No. 13 ( 2024-06-26), p. 5571-
    Details
    In: Applied Sciences, MDPI AG, Vol. 14, No. 13 ( 2024-06-26), p. 5571-
    Abstract: The aim of this cross-sectional study was to assess the influence of the maturity status on speed, explosive power and change of direction (COD) in 13-year-old football players. Ninety-eight male players (age: 13.1 ± 1.0 y) were divided into late, average and early-maturation groups. Physical fitness testing included the following variables: 10 and 30 m sprint time and maximum speed in the 20–30 m segment of the 30 m sprint test, the T-test time, countermovement jump height and horizontal distance in the triple jump. The data showed a significant effect of maturity status on performance in three parameters: at maximum speed in the 20–30 m section (p = 0.024), but the only significant differences were found between the early-maturation group and average-maturation group (p = 0.033); in the COD (p = 0.024), where significant differences were confirmed between the late-maturation group and the average-maturation group (p = 0.033); and in the unilateral triple jump distance of the dominant and non-dominant (p = 0.007 and p = 0.001, respectively) lower limb. For both limbs, significant differences between the late-maturation group and average-maturation group (p = 0.005 and p = 0.013, respectively) as well as the late-maturation group and early-maturation group (p = 0.007 and p = 0.045, respectively) were shown. These results indicate that maximal speed, COD speed and unilateral lower limb reactive strength are moderated by biological age in football players aged 13 years.
    Type of Medium: Online Resource
    ISSN: 2076-3417
    URL: Article
    DOI: 10.3390/app14135571
    Language: English
    Publisher: MDPI AG
    Publication Date: 2024
    detail.hit.zdb_id: 2704225-X
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  • 3
    Online Resource
    Online Resource
    An In Vivo Microfluidic Study of Bacterial Load Dynamics and Absorption in the C. elegans Intestine
    MDPI AG ; 2021
    In:  Micromachines Vol. 12, No. 7 ( 2021-07-17), p. 832-
    Details
    In: Micromachines, MDPI AG, Vol. 12, No. 7 ( 2021-07-17), p. 832-
    Abstract: Caenorhabditiselegans (C. elegans) has gained importance as a model for studying host-microbiota interactions and bacterial infections related to human pathogens. Assessing the fate of ingested bacteria in the worm’s intestine is therefore of great interest, in particular with respect to normal bacterial digestion or intestinal colonization by pathogens. Here, we report an in vivo study of bacteria in the gut of C. elegans. We take advantage of a polydimethylsiloxane (PDMS) microfluidic device enabling passive immobilization of adult worms under physiological conditions. Non-pathogenic Escherichia coli (E. coli) bacteria expressing either pH-sensitive or pH-insensitive fluorescence reporters as well as fluorescently marked indigestible microbeads were used for the different assays. Dynamic fluorescence patterns of the bacterial load in the worm gut were conveniently monitored by time-lapse imaging. Cyclic motion of the bacterial load due to peristaltic activity of the gut was observed and biochemical digestion of E. coli was characterized by high-resolution fluorescence imaging of the worm’s intestine. We could discriminate between individual intact bacteria and diffuse signals related to disrupted bacteria that can be digested. From the decay of the diffuse fluorescent signal, we determined a digestion time constant of 14 ± 4 s. In order to evaluate the possibility to perform infection assays with our platform, immobilized C. elegans worms were fed pathogenic Mycobacterium marinum (M. marinum) bacteria. We analyzed bacterial fate and accumulation in the gut of N2 worms and mitochondrial stress response in a hsp-6::gfp mutant.
    Type of Medium: Online Resource
    ISSN: 2072-666X
    URL: Article
    DOI: 10.3390/mi12070832
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2620864-7
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  • 4
    Online Resource
    Online Resource
    Influence of Stoichiometry on the Two-Phase Flow Behavior of Proton Exchange Membrane Electrolyzers
    MDPI AG ; 2019
    In:  Energies Vol. 12, No. 3 ( 2019-01-23), p. 350-
    Details
    In: Energies, MDPI AG, Vol. 12, No. 3 ( 2019-01-23), p. 350-
    Abstract: In order for electrolysis cells to operate optimally, mass transport must be improved. The key initial component for optimal operation is the current collector, which is also essential for mass transport. Water as an educt of the reaction must be evenly distributed by the current collector to the membrane electrode assembly. As products of the reaction, hydrogen and oxygen must also be directed quickly and efficiently through the current collector into the channel and removed from the cell. The second key component is the stoichiometry, which includes the current density and water volume flow rate and represents the ratio between the water supplied and water consumed. This study presents the correlation of the stoichiometry, two-phase flow in the channel and gas fraction in the porous transport layer for the first time. The gas-water ratio in the channel and porous transport layer during cell operation with various stoichiometries was investigated by means of a model in the form of an ex situ cell without electrochemical processes. Bubble formation in the channel was observed using a transparent cell. The gas-water exchange in the porous transport layer was then investigated using neutron radiography.
    Type of Medium: Online Resource
    ISSN: 1996-1073
    URL: Article
    DOI: 10.3390/en12030350
    Language: English
    Publisher: MDPI AG
    Publication Date: 2019
    detail.hit.zdb_id: 2437446-5
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  • 5
    Online Resource
    Online Resource
    Mesothelin Gene Variants Affect Soluble Mesothelin-Related Protein Levels in the Plasma of Asbestos-Exposed Males and Mesothelioma Patients from Germany
    MDPI AG ; 2022
    In:  Biology Vol. 11, No. 12 ( 2022-12-14), p. 1826-
    Details
    In: Biology, MDPI AG, Vol. 11, No. 12 ( 2022-12-14), p. 1826-
    Abstract: Malignant mesothelioma (MM) is a severe disease mostly caused by asbestos exposure. Today, one of the best available biomarkers is the soluble mesothelin-related protein (SMRP), also known as mesothelin. Recent studies have shown that mesothelin levels are influenced by individual genetic variability. This study aimed to investigate the influence of three mesothelin (MSLN) gene variants (SNPs) in the 5′-untranslated promoter region (5′-UTR), MSLN rs2235503 C 〉 A, rs3764246 A 〉 G, rs3764247 A 〉 C, and one (rs1057147 G 〉 A) in the 3′-untranslated region (3′-UTR) of the MSLN gene on plasma concentrations of mesothelin in 410 asbestos-exposed males without cancer and 43 males with prediagnostic MM (i.e., with MM diagnosed later on) from the prospective MoMar study, as well as 59 males with manifest MM from Germany. The mesothelin concentration differed significantly between the different groups (p 〈 0.0001), but not between the prediagnostic and manifest MM groups (p = 0.502). Five to eight mutations of the four SNP variants studied were associated with increased mesothelin concentrations (p = 0.001). The highest mesothelin concentrations were observed for homozygous variants of the three promotor SNPs in the 5′-UTR (p 〈 0.001), and the highest odds ratio for an elevated mesothelin concentration was observed for MSLN rs2235503 C 〉 A. The four studied SNPs had a clear influence on the mesothelin concentration in plasma. Hence, the analysis of these SNPs may help to elucidate the diagnostic background of patients displaying increased mesothelin levels and might help to reduce false-positive results when using mesothelin for MM screening in high-risk groups.
    Type of Medium: Online Resource
    ISSN: 2079-7737
    URL: Article
    DOI: 10.3390/biology11121826
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2661517-4
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  • 6
    Online Resource
    Online Resource
    Impairment of Motor Function Correlates with Neurometabolite and Brain Iron Alterations in Parkinson’s Disease
    MDPI AG ; 2019
    In:  Cells Vol. 8, No. 2 ( 2019-01-29), p. 96-
    Details
    In: Cells, MDPI AG, Vol. 8, No. 2 ( 2019-01-29), p. 96-
    Abstract: We took advantage of magnetic resonance imaging (MRI) and spectroscopy (MRS) as non-invasive methods to quantify brain iron and neurometabolites, which were analyzed along with other predictors of motor dysfunction in Parkinson’s disease (PD). Tapping hits, tremor amplitude, and the scores derived from part III of the Movement Disorder Society-Sponsored Revision of the Unified Parkinson Disease Rating Scale (MDS-UPDRS3 scores) were determined in 35 male PD patients and 35 controls. The iron-sensitive MRI relaxation rate R2* was measured in the globus pallidus and substantia nigra. γ-aminobutyric acid (GABA)-edited and short echo-time MRS was used for the quantification of neurometabolites in the striatum and thalamus. Associations of R2*, neurometabolites, and other factors with motor function were estimated with Spearman correlations and mixed regression models to account for repeated measurements (hands, hemispheres). In PD patients, R2* and striatal GABA correlated with MDS-UPDRS3 scores if not adjusted for age. Patients with akinetic-rigid PD subtype (N = 19) presented with lower creatine and striatal glutamate and glutamine (Glx) but elevated thalamic GABA compared to controls or mixed PD subtype. In PD patients, Glx correlated with an impaired dexterity when adjusted for covariates. Elevated myo-inositol was associated with more tapping hits and lower MDS-UPDRS3 scores. Our neuroimaging study provides evidence that motor dysfunction in PD correlates with alterations in brain iron and neurometabolites.
    Type of Medium: Online Resource
    ISSN: 2073-4409
    URL: Article
    DOI: 10.3390/cells8020096
    Language: English
    Publisher: MDPI AG
    Publication Date: 2019
    detail.hit.zdb_id: 2661518-6
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  • 7
    Online Resource
    Online Resource
    Improving the Efficiency of PEM Electrolyzers through Membrane-Specific Pressure Optimization
    MDPI AG ; 2020
    In:  Energies Vol. 13, No. 3 ( 2020-02-01), p. 612-
    Details
    In: Energies, MDPI AG, Vol. 13, No. 3 ( 2020-02-01), p. 612-
    Abstract: Hydrogen produced in a polymer electrolyte membrane (PEM) electrolyzer must be stored under high pressure. It is discussed whether the gas should be compressed in subsequent gas compressors or by the electrolyzer. While gas compressor stages can be reduced in the case of electrochemical compression, safety problems arise for thin membranes due to the undesired permeation of hydrogen across the membrane to the oxygen side, forming an explosive gas. In this study, a PEM system is modeled to evaluate the membrane-specific total system efficiency. The optimum efficiency is given depending on the external heat requirement, permeation, cell pressure, current density, and membrane thickness. It shows that the heat requirement and hydrogen permeation dominate the maximum efficiency below 1.6 V, while, above, the cell polarization is decisive. In addition, a pressure-optimized cell operation is introduced by which the optimum cathode pressure is set as a function of current density and membrane thickness. This approach indicates that thin membranes do not provide increased safety issues compared to thick membranes. However, operating an N212-based system instead of an N117-based one can generate twice the amount of hydrogen at the same system efficiency while only one compressor stage must be added.
    Type of Medium: Online Resource
    ISSN: 1996-1073
    URL: Article
    DOI: 10.3390/en13030612
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2437446-5
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  • 8
    Online Resource
    Online Resource
    Olfaction as a Marker for Dystonia: Background, Current State and Directions
    MDPI AG ; 2020
    In:  Brain Sciences Vol. 10, No. 10 ( 2020-10-13), p. 727-
    Details
    In: Brain Sciences, MDPI AG, Vol. 10, No. 10 ( 2020-10-13), p. 727-
    Abstract: Dystonia is a heterogeneous group of hyperkinetic movement disorders. The unifying descriptor of dystonia is the motor manifestation, characterized by continuous or intermittent contractions of muscles that cause abnormal movements and postures. Additionally, there are psychiatric, cognitive, and sensory alterations that are possible or putative non-motor manifestations of dystonia. The pathophysiology of dystonia is incompletely understood. A better understanding of dystonia pathophysiology is highly relevant in the amelioration of significant disability associated with motor and non-motor manifestations of dystonia. Recently, diminished olfaction was found to be a potential non-motor manifestation that may worsen the situation of subjects with dystonia. Yet, this finding may also shed light into dystonia pathophysiology and yield novel treatment options. This article aims to provide background information on dystonia and the current understanding of its pathophysiology, including the key structures involved, namely, the basal ganglia, cerebellum, and sensorimotor cortex. Additionally, involvement of these structures in the chemical senses are reviewed to provide an overview on how olfactory (and gustatory) deficits may occur in dystonia. Finally, we describe the present findings on altered chemical senses in dystonia and discuss directions of research on olfactory dysfunction as a marker in dystonia.
    Type of Medium: Online Resource
    ISSN: 2076-3425
    URL: Article
    DOI: 10.3390/brainsci10100727
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2651993-8
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  • 9
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    Online Resource
    Design and Modeling of Metallic Bipolar Plates for a Fuel Cell Range Extender
    MDPI AG ; 2021
    In:  Energies Vol. 14, No. 17 ( 2021-09-02), p. 5484-
    Details
    In: Energies, MDPI AG, Vol. 14, No. 17 ( 2021-09-02), p. 5484-
    Abstract: Fuel cells, designed for mobile applications, should feature compact and low-weight designs. This study describes a design process that fulfills the specific needs of target applications and the production process. The key challenge for this type of metallic bipolar plate is that the combination of two plates creates three flow fields, namely an anode side, a cathode side, and a coolant. This illustrates the fact that each cell constitutes an electrochemical converter with an integrated heat exchanger. The final arrangement is comprised of plates with parallel and separate serpentine channel configurations. The anode and cathode sides are optimized for operation under dry conditions. The final plate offers an almost perfect distribution of coolant flow over the active area. The high quality of this distribution is almost independent of the coolant mass flow, even if one of the six inlet channels is blocked. The software employed (OpenFOAM and SALOME) is freely available and can be used with templates.
    Type of Medium: Online Resource
    ISSN: 1996-1073
    URL: Article
    DOI: 10.3390/en14175484
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2437446-5
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  • 10
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    Online Resource
    Deep Underground Neutrino Experiment (DUNE) Near Detector Conceptual Design Report
    MDPI AG ; 2021
    In:  Instruments Vol. 5, No. 4 ( 2021-09-29), p. 31-
    Details
    In: Instruments, MDPI AG, Vol. 5, No. 4 ( 2021-09-29), p. 31-
    Abstract: The Deep Underground Neutrino Experiment (DUNE) is an international, world-class experiment aimed at exploring fundamental questions about the universe that are at the forefront of astrophysics and particle physics research. DUNE will study questions pertaining to the preponderance of matter over antimatter in the early universe, the dynamics of supernovae, the subtleties of neutrino interaction physics, and a number of beyond the Standard Model topics accessible in a powerful neutrino beam. A critical component of the DUNE physics program involves the study of changes in a powerful beam of neutrinos, i.e., neutrino oscillations, as the neutrinos propagate a long distance. The experiment consists of a near detector, sited close to the source of the beam, and a far detector, sited along the beam at a large distance. This document, the DUNE Near Detector Conceptual Design Report (CDR), describes the design of the DUNE near detector and the science program that drives the design and technology choices. The goals and requirements underlying the design, along with projected performance are given. It serves as a starting point for a more detailed design that will be described in future documents.
    Type of Medium: Online Resource
    ISSN: 2410-390X
    URL: Article
    DOI: 10.3390/instruments5040031
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2911707-0
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