Publications by authors named "Thomas Maier"

124 Publications

Discrimination of Species by Combining MALDI-TOF Protein Profile, Chaperonin Sequences, and Phenotypic Characteristics.

Pathogens 2021 Mar 1;10(3). Epub 2021 Mar 1.

Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio al. 7, 10257 Vilnius, Lithuania.

The description of was recently updated and three new species, including nine genome species within , were defined using whole genome sequences and matrix assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. A fast and simple method based on readily available techniques would be of immense use to identify species in research and clinical practice. Here we show that 34 previously characterized isolates were assigned to the species using partial chaperonin sequences. The MALDI Biotyper from Bruker Daltonik GmbH demonstrated the capability to differentiate the phylogenetically diverse groups composed of / and /. Among the phenotypic properties that characterize species are sialidase and β-galactosidase activities. Our data confirmed that the NanH3 enzyme is responsible for sialidase activity in spp. isolates. Almost all isolates displayed a sialidase positive phenotype, whereas the majority of strains were sialidase negative. and displayed a sialidase negative phenotype. β-galactosidase is produced exclusively in . strains. Earlier determined phenotypic characteristics associated with virulence of isolates now assigned to the defined species may provide insights on how diverse species contribute to shaping the vaginal microbiome.
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http://dx.doi.org/10.3390/pathogens10030277DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7998583PMC
March 2021

Toward genetic modification of plant-parasitic nematodes: delivery of macromolecules to adults and expression of exogenous mRNA in second stage juveniles.

G3 (Bethesda) 2021 Feb;11(2)

Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK.

Plant-parasitic nematodes are a continuing threat to food security, causing an estimated 100 billion USD in crop losses each year. The most problematic are the obligate sedentary endoparasites (primarily root knot nematodes and cyst nematodes). Progress in understanding their biology is held back by a lack of tools for functional genetics: forward genetics is largely restricted to studies of natural variation in populations and reverse genetics is entirely reliant on RNA interference. There is an expectation that the development of functional genetic tools would accelerate the progress of research on plant-parasitic nematodes, and hence the development of novel control solutions. Here, we develop some of the foundational biology required to deliver a functional genetic tool kit in plant-parasitic nematodes. We characterize the gonads of male Heterodera schachtii and Meloidogyne hapla in the context of spermatogenesis. We test and optimize various methods for the delivery, expression, and/or detection of exogenous nucleic acids in plant-parasitic nematodes. We demonstrate that delivery of macromolecules to cyst and root knot nematode male germlines is difficult, but possible. Similarly, we demonstrate the delivery of oligonucleotides to root knot nematode gametes. Finally, we develop a transient expression system in plant-parasitic nematodes by demonstrating the delivery and expression of exogenous mRNA encoding various reporter genes throughout the body of H. schachtii juveniles using lipofectamine-based transfection. We anticipate these developments to be independently useful, will expedite the development of genetic modification tools for plant-parasitic nematodes, and ultimately catalyze research on a group of nematodes that threaten global food security.
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http://dx.doi.org/10.1093/g3journal/jkaa058DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8022973PMC
February 2021

A new esophageal gland transcriptome reveals signatures of large scale de novo effector birth in the root lesion nematode Pratylenchus penetrans.

BMC Genomics 2020 Oct 23;21(1):738. Epub 2020 Oct 23.

USDA-ARS, Molecular Plant Pathology Laboratory, Beltsville, MD, 20705-2350, USA.

Background: The root lesion nematode Pratylenchus penetrans is a migratory plant-parasitic nematode responsible for economically important losses in a wide number of crops. Despite the importance of P. penetrans, the molecular mechanisms employed by this nematode to promote virulence remain largely unknown.

Results: Here we generated a new and comprehensive esophageal glands-specific transcriptome library for P. penetrans. In-depth analysis of this transcriptome enabled a robust identification of a catalogue of 30 new candidate effector genes, which were experimentally validated in the esophageal glands by in situ hybridization. We further validated the expression of a multifaceted network of candidate effectors during the interaction with different plants. To advance our understanding of the "effectorome" of P. penetrans, we adopted a phylogenetic approach and compared the expanded effector repertoire of P. penetrans to the genome/transcriptome of other nematode species with similar or contrasting parasitism strategies. Our data allowed us to infer plausible evolutionary histories that shaped the effector repertoire of P. penetrans, as well as other close and distant plant-parasitic nematodes. Two remarkable trends were apparent: 1) large scale effector birth in the Pratylenchidae in general and P. penetrans in particular, and 2) large scale effector death in sedentary (endo) plant-parasitic nematodes.

Conclusions: Our study doubles the number of validated Pratylenchus penetrans effectors reported in the literature. The dramatic effector gene gain in P. penetrans could be related to the remarkable ability of this nematode to parasitize a large number of plants. Our data provide valuable insights into nematode parasitism and contribute towards basic understating of the adaptation of P. penetrans and other root lesion nematodes to specific host plants.
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http://dx.doi.org/10.1186/s12864-020-07146-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7585316PMC
October 2020

Low-Valence Anionic α-Diimine Iron Complexes: Synthesis, Characterization, and Catalytic Hydroboration Studies.

Inorg Chem 2020 Nov 20;59(21):16035-16052. Epub 2020 Oct 20.

Institute of Inorganic Chemistry, University of Göttingen, Tammannstrasse 4, 37077 Göttingen, Germany.

The synthesis of rare anionic heteroleptic and homoleptic α-diimine iron complexes is described. Heteroleptic BIAN (bis(aryl)iminoacenaphthene) complexes -[K([18]c-6)(thf)] and -[K([18]c-6)(thf)] were synthesized by reduction of the [(BIAN)FeBr] precursor complex using stoichiometric amounts of potassium graphite in the presence of the corresponding olefin. The electronic structure of these paramagnetic species was investigated by numerous spectroscopic analyses (NMR, EPR, Fe Mössbauer, UV-vis), magnetic measurements (Evans NMR method, SQUID), and theoretical techniques (DFT, CASSCF). Whereas anion is a low-spin complex, anion consists of an intermediate-spin Fe(III) center. Both complexes are efficient precatalysts for the hydroboration of carbonyl compounds under mild reaction conditions. The reaction of bis(anthracene) ferrate(1-) gave the homoleptic BIAN complex -[K([18]c-6)(thf)], which is less catalytically active. The electronic structure was elucidated with the same techniques as described for complexes -[K([18]c-6)(thf)] and -[K([18]c-6)(thf)] and revealed an Fe(II) species in a quartet ground state.
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http://dx.doi.org/10.1021/acs.inorgchem.0c02606DOI Listing
November 2020

Evaluation of Microsatellite Typing, ITS Sequencing, AFLP Fingerprinting, MALDI-TOF MS, and Fourier-Transform Infrared Spectroscopy Analysis of .

J Fungi (Basel) 2020 Aug 25;6(3). Epub 2020 Aug 25.

Westerdijk Fungal Biodiversity Institute, 3584 CT Utrecht, The Netherlands.

is an emerging opportunistic yeast species causing nosocomial outbreaks at a global scale. A few studies have focused on the genotypic structure. Here, we compared five epidemiological typing tools using a set of 96 isolates from 14 geographical areas. Isolates were analyzed by microsatellite typing, ITS sequencing, amplified fragment length polymorphism (AFLP) fingerprint analysis, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), and Fourier-transform infrared (FTIR) spectroscopy methods. Microsatellite typing grouped the isolates into four main clusters, corresponding to the four known clades in concordance with whole genome sequencing studies. The other investigated typing tools showed poor performance compared with microsatellite typing. A comparison between the five methods showed the highest agreement between microsatellite typing and ITS sequencing with 45% similarity, followed by microsatellite typing and the FTIR method with 33% similarity. The lowest agreement was observed between FTIR spectroscopy, MALDI-TOF MS, and ITS sequencing. This study indicates that microsatellite typing is the tool of choice for outbreak investigations. Additionally, FTIR spectroscopy requires further optimization and evaluation before it can be used as an epidemiological typing method, comparable with microsatellite typing, as a rapid method for tracing nosocomial fungal outbreaks.
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http://dx.doi.org/10.3390/jof6030146DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7576496PMC
August 2020

Heterogeneous Olefin Hydrogenation Enabled by a Highly-Reduced Nickel(-II) Catalyst Precursor.

Chemistry 2020 May 30;26(28):6089. Epub 2020 Apr 30.

University of Regensburg, Institute of Inorganic Chemistry, 93040, Regensburg, Germany.

Invited for the cover of this issue is the group of Robert Wolf at the University of Regensburg and colleagues at the University of Hamburg. The image depicts the hydrogenation of triphenylethylene. Read the full text of the article at 10.1002/chem.201905537.
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http://dx.doi.org/10.1002/chem.202001019DOI Listing
May 2020

Lateral silicon oxide/gold interfaces enhance the rate of electrochemical hydrogen evolution reaction in alkaline media.

J Chem Phys 2020 Apr;152(15):154705

Nonequilibrium Chemical Physics, Department of Physics, Technical University of Munich, 85748 Garching, Germany.

The production of solar hydrogen with a silicon based water splitting device is a promising future technology, and silicon-based metal-insulator-semiconductor (MIS) electrodes have been proposed as suitable architectures for efficient photocathodes based on the electronic properties of the MIS structures and the catalytic properties of the metals. In this paper, we demonstrate that the interfaces between the metal and oxide of laterally patterned MIS electrodes may strongly enhance the catalytic activity of the electrode compared to bulk metal surfaces. The employed electrodes consist of well-defined, large-area arrays of gold structures of various mesoscopic sizes embedded in a silicon oxide support on silicon. We demonstrate that the activity of these electrodes for hydrogen evolution reaction (HER) increases with an increase in gold/silicon oxide boundary length in both acidic and alkaline media, although the enhancement of the HER rate in alkaline electrolytes is considerably larger than in acidic electrolytes. Electrodes with the largest interfacial length of gold/silicon oxide exhibited a 10-times larger HER rate in alkaline electrolytes than those with the smallest interfacial length. The data suggest that at the metal/silicon oxide boundaries, alkaline HER is enhanced through a bifunctional mechanism, which we tentatively relate to the laterally structured electrode geometry and to positive charges present in silicon oxide: Both properties change locally the interfacial electric field at the gold/silicon oxide boundary, which, in turn, facilitates a faster transport of hydroxide ions away from the electrode/electrolyte interface in alkaline solution. This mechanism boosts the alkaline HER activity of p-type silicon based photoelectrodes close to their HER activity in acidic electrolytes.
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http://dx.doi.org/10.1063/5.0003295DOI Listing
April 2020

Heterogeneous Olefin Hydrogenation Enabled by a Highly-Reduced Nickel(-II) Catalyst Precursor.

Chemistry 2020 May 24;26(28):6113-6117. Epub 2020 Apr 24.

University of Regensburg, Institute of Inorganic Chemistry, 93040, Regensburg, Germany.

The hydrogenation of olefins, styrenes, enoates, imines, and sterically hindered tri-substituted olefins was accomplished using the pre-catalyst dilithiumbis(cycloocta-1,5-diene)nickelate(-II) (1). The mild conditions tolerate hydroxyl, halide, ester, and lactone functionalities. Mechanistic studies, including reaction progress analyses, poisoning experiments, and multinuclear NMR monitoring, indicate that a heterotopic (nickel nanoparticle) catalyst is in operation.
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http://dx.doi.org/10.1002/chem.201905537DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7318650PMC
May 2020

Differentiation of Rodentibacter pneumotropicus, Rodentibacter heylii and Muribacter muris by MALDI-TOF MS.

J Microbiol Methods 2020 02 7;169:105836. Epub 2020 Jan 7.

Institute of Bacteriology and Mycology, Faculty of Veterinary Medicine, University Leipzig, Leipzig, Germany. Electronic address:

The pathogens Rodentibacter (R.) pneumotropicus and R. heylii as well as the commensal Muribacter (M.) muris are frequently isolated in mice. In this study, a MALDI-TOF MS database was extended with spectra of well characterized strains of these species. Compared to a multiplex PCR, all examined out-of-sample isolates were correctly identified.
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http://dx.doi.org/10.1016/j.mimet.2020.105836DOI Listing
February 2020

Multicenter Study Demonstrates Standardization Requirements for Mold Identification by MALDI-TOF MS.

Front Microbiol 2019 20;10:2098. Epub 2019 Sep 20.

Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, United States.

Objectives: Rapid and accurate mold identification is critical for guiding therapy for mold infections. MALDI-TOF MS has been widely adopted for bacterial and yeast identification; however, few clinical laboratories have applied this technology for routine mold identification due to limited database availability and lack of standardized processes. Here, we evaluated the versatility of the NIH Mold Database in a multicenter evaluation.

Methods: The NIH Mold Database was evaluated by eight US academic centers using a solid media extraction method and a challenge set of 80 clinical mold isolates. Multiple instrument parameters important for spectra optimization were evaluated, leading to the development of two specialized acquisition programs (NIH method and the Alternate-B method).

Results: A wide range in performance (33-77%) was initially observed across the eight centers when routine spectral acquisition parameters were applied. Use of the NIH or the Alternate-B specialized acquisition programs, which are different than those used routinely for bacterial and yeast spectral acquisition (MBT_AutoX), in combination with optimized instrument maintenance, improved performance, illustrating that acquisition parameters may be one of the key limiting variable in achieving successful performance.

Conclusion: Successful mold identification using the NIH Database for MALDI-TOF MS on Biotyper systems was demonstrated across multiple institutions for the first time following identification of critical program parameters combined with instrument optimization. This significantly advances our potential to implement MALDI-TOF MS for mold identification across many institutions. Because instrument variability is inevitable, development of an instrument performance standard specific for mold spectral acquisition is suggested to improve reproducibility across instruments.
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http://dx.doi.org/10.3389/fmicb.2019.02098DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6764242PMC
September 2019

Direct synthesis of an anionic 13-vertex closo-cobaltacarborane cluster.

Dalton Trans 2019 Nov 15;48(42):15772-15777. Epub 2019 Oct 15.

University of Regensburg, Institute of Inorganic Chemistry, 93040 Regensburg, Germany.

Reaction of 1,2-bis(diphenylphosphino)-ortho-carborane (L) with [K(thf){(BIAN)Co(η-cod)}] (1, BIAN = bis(mesityliminoace-naphthene)diimine, cod = 1,5-cyclooctadiene) affords an anionic 13-vertex closo-cobaltacarborane cluster (2) in one step. The mechanism of this transformation has been studied by experimental and quantum chemical techniques, which suggest that a series of outer-sphere electron transfer and isomerisation processes occurs. This work shows that low-valent metalate anions are promising reagents for the synthesis of anionic metallacarborane clusters.
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http://dx.doi.org/10.1039/c9dt03111aDOI Listing
November 2019

[3+2] Fragmentation of a Pentaphosphido Ligand by Cyanide.

Angew Chem Int Ed Engl 2019 Dec 7;58(52):18931-18936. Epub 2019 Nov 7.

University of Regensburg, Institute of Inorganic Chemistry, 93040, Regensburg, Germany.

The activation of white phosphorus (P ) by transition-metal complexes has been studied for several decades, but the functionalization and release of the resulting (organo)phosphorus ligands has rarely been achieved. Herein we describe the formation of rare diphosphan-1-ide anions from a P ligand by treatment with cyanide. Cobalt diorganopentaphosphido complexes have been synthesized by a stepwise reaction sequence involving a low-valent diimine cobalt complex, white phosphorus, and diorganochlorophosphanes. The reactions of the complexes with tetraalkylammonium or potassium cyanide afford a cyclotriphosphido cobaltate anion 5 and 1-cyanodiphosphan-1-ide anions [R PPCN] (6-R). The molecular structure of a related product 7 suggests a novel reaction mechanism, where coordination of the cyanide anion to the cobalt center induces a ligand rearrangement. This is followed by nucleophilic attack of a second cyanide anion at a phosphorus atom and release of the P fragment.
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http://dx.doi.org/10.1002/anie.201908744DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6972699PMC
December 2019

Construction of alkyl-substituted pentaphosphido ligands in the coordination sphere of cobalt.

Chem Sci 2019 Feb 4;10(5):1302-1308. Epub 2018 Dec 4.

University of Regensburg , Institute of Inorganic Chemistry , 93040 Regensburg , Germany . Email:

Rare mono- and diorganopentaphosphido cobalt complexes are accessible by P-P condensation using the unprecedented, reactive cobalt-gallium tetraphosphido complex [K(dme){(BIAN)Co(μ-η:η-P)Ga(nacnac)}] (). Compound was prepared in good yield by reaction of [K(EtO){(BIAN)Co(η-1,5-cod)}] [, BIAN = bis(mesitylimino)acenaphthene diimine, cod = 1,5-cyclooctadiene] with [Ga(nacnac)(η-P)] (nacnac = CH[CMeN(2,6-iPrCH)]). Reactions with RPCl (R = iPr, Bu, and Cy) selectively afford [(BIAN)Co(-PR)] (), which feature η-coordinated 1,1-diorganopentaphosphido ligands. The mechanism of formation of these species has been studied by P{H} NMR spectroscopy and DFT calculations. In the case of (R = iPr), it was possible to identify the intermediate [(BIAN)Co(μ-η:η-PiPr)Ga(nacnac)] () by single-crystal X-ray diffraction. A related, monosubstituted organopentaphosphido cobalt complex [(BIAN)Co(μ-η:η-PBu)GaCl(nacnac)] () was isolated by reacting dichloroalkylphosphane BuPCl with . Heterobimetallic complexes such as thus may enable the targeted construction of a range of new metal-coordinated polyphosphorus frameworks by P-P condensation.
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http://dx.doi.org/10.1039/c8sc04745fDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6357856PMC
February 2019

Re-targeting of a plant defense protease by a cyst nematode effector.

Plant J 2019 06 1;98(6):1000-1014. Epub 2019 Apr 1.

Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA.

Plants mount defense responses during pathogen attacks, and robust host defense suppression by pathogen effector proteins is essential for infection success. 4E02 is an effector of the sugar beet cyst nematode Heterodera schachtii. Arabidopsis thaliana lines expressing the effector-coding sequence showed altered expression levels of defense response genes, as well as higher susceptibility to both the biotroph H. schachtii and the necrotroph Botrytis cinerea, indicating a potential suppression of defenses by 4E02. Yeast two-hybrid analyses showed that 4E02 targets A. thaliana vacuolar papain-like cysteine protease (PLCP) 'Responsive to Dehydration 21A' (RD21A), which has been shown to function in the plant defense response. Activity-based protein profiling analyses documented that the in planta presence of 4E02 does not impede enzymatic activity of RD21A. Instead, 4E02 mediates a re-localization of this protease from the vacuole to the nucleus and cytoplasm, which is likely to prevent the protease from performing its defense function and at the same time, brings it in contact with novel substrates. Yeast two-hybrid analyses showed that RD21A interacts with multiple host proteins including enzymes involved in defense responses as well as carbohydrate metabolism. In support of a role in carbohydrate metabolism of RD21A after its effector-mediated re-localization, we observed cell wall compositional changes in 4E02 expressing A. thaliana lines. Collectively, our study shows that 4E02 removes RD21A from its defense-inducing pathway and repurposes this enzyme by targeting the active protease to different cell compartments.
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http://dx.doi.org/10.1111/tpj.14295DOI Listing
June 2019

Heterodera glycines utilizes promiscuous spliced leaders and demonstrates a unique preference for a species-specific spliced leader over C. elegans SL1.

Sci Rep 2019 02 4;9(1):1356. Epub 2019 Feb 4.

Plant Pathology & Microbiology Department, Iowa State University, Ames, IA, 50011, USA.

Spliced leader trans-splicing (SLTS) plays a part in the maturation of pre-mRNAs in select species across multiple phyla but is particularly prevalent in Nematoda. The role of spliced leaders (SL) within the cell is unclear and an accurate assessment of SL occurrence within an organism is possible only after extensive sequencing data are available, which is not currently the case for many nematode species. SL discovery is further complicated by an absence of SL sequences from high-throughput sequencing results due to incomplete sequencing of the 5'-ends of transcripts during RNA-seq library preparation, known as 5'-bias. Existing datasets and novel methodology were used to identify both conserved SLs and unique hypervariable SLs within Heterodera glycines, the soybean cyst nematode. In H. glycines, twenty-one distinct SL sequences were found on 2,532 unique H. glycines transcripts. The SL sequences identified on the H. glycines transcripts demonstrated a high level of promiscuity, meaning that some transcripts produced as many as nine different individual SL-transcript combinations. Most uniquely, transcriptome analysis revealed that H. glycines is the first nematode to demonstrate a higher SL trans-splicing rate using a species-specific SL over well-conserved Caenorhabditis elegans SL-like sequences.
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http://dx.doi.org/10.1038/s41598-018-37857-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6362198PMC
February 2019

Hexaammineruthenium (II)/(III) as alternative redox-probe to Hexacyanoferrat (II)/(III) for stable impedimetric biosensing with gold electrodes.

Biosens Bioelectron 2019 Feb 13;127:25-30. Epub 2018 Dec 13.

AIT Austrian Institute of Technology GmbH, 1210 Vienna, Austria.

Gold electrodes have been used in a wide range of electrochemical biosensors because their functionalization process with thiols has been well described and, in general, they offer good chemical stability. However, one of the most commonly used redox-pairs in electrochemical impedance spectroscopy, Hexacyanoferrate (II)/(III), causes corrosion of the gold electrodes and consequently damages the surface modification. This leads to alterations of the sensing signals, and thus, renders the quantitative and sensitive detection of target molecules virtually impossible. To overcome this problem we introduced the in-situ generation of Hexaammineruthenium (II)/(III) as redox-pair during the impedimetric measurement by applying a DC-bias. This DC-bias was chosen in such a way that it supplied Hexaammineruthenium (II) in a suitable concentration at the electrode surface by reducing Hexaammineruthenium (III). We compared the stability of photolithographically fabricated thin-film and screen-printed gold electrodes in Hexacyanoferrate and Hexaammineruthenium solutions. Further, long-time characterization of the electrochemical properties with cyclic voltammetry and electrochemical impedance spectroscopy revealed that Hexaammineruthenium (II)/(III) was an excellent redox-pair for stable impedimetric measurements with gold electrodes. To demonstrate the suitability of Hexaammineruthenium for biosensing we applied it for the impedimetric detection of human-IgG. This biosensor exhibited a linear range from 11.3 ng/mL to 113 μg/mL, which is a suitable range for diagnostic applications.
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http://dx.doi.org/10.1016/j.bios.2018.12.007DOI Listing
February 2019

Influence of wheel rim width on rolling resistance and off-road speed in cross-country mountain biking.

J Sports Sci 2019 Apr 18;37(7):833-838. Epub 2018 Dec 18.

a Section for Elite Sport , Swiss Federal Institute of Sport , Magglingen , Switzerland.

The rim width of cross-country mountain bike wheel sets has increased in recent years, but the effect of this increase on performance remains unknown. The aim of this study was to analyse the influence of rim width on rolling resistance and off-road speed. We compared 3 tubeless wheel sets: 25 mm inner width as baseline, 30 mm width with the same tyre stiffness, and 30 mm width with the same tyre pressure. Three riders conducted 75 rolling resistance tests for each wheel set on a cross-country course. We determined rolling resistance using the virtual elevation method and calculated off-road speeds for flat and uphill conditions using a mathematical model. Baseline rolling resistance (C) was 0.0298, 90% CI [0.0286, 0.0310], which decreased by 1.4%, [0.7, 2.2] with the wider rim and the same tyre stiffness and increased by 0.9%, [0.1, 1.6] with the wider rim and the same tyre pressure. The corresponding effects on off-road speed were most likely trivial (0.0% to 0.7% faster and 0.1% to 0.6% slower, respectively). Because the effect of rim width on off-road speed seems negligible, athletes should choose the rim width that offers the best bike handling and should experiment with low tyre pressures.
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http://dx.doi.org/10.1080/02640414.2018.1530057DOI Listing
April 2019

Effect of Endurance Training on Hemoglobin Mass and V˙O2max in Male Adolescent Athletes.

Med Sci Sports Exerc 2019 05;51(5):912-919

Section for Elite Sport, Swiss Federal Institute of Sport, Magglingen, SWITZERLAND.

Purpose: It is unknown, whether endurance training stimulates hemoglobin mass (Hbmass) and maximal oxygen uptake (V˙O2max) increases during late adolescence. Therefore, this study assessed the influence of endurance training on Hbmass, blood volume parameters, and V˙O2max in endurance athletes and control subjects from age 16 to 19 yr.

Methods: Hemoglobin mass, blood volume parameters, V˙O2max and anthropometric parameters were measured in male elite endurance athletes from age 16 to 19 yr in 6-month intervals (n = 10), as well as in age-matched male controls (n = 12).

Results: Neither the level of Hbmass per lean body mass (LBM) (P = 0.80) nor the development of Hbmass during the 3 yr (P = 0.97) differed between athletes and controls. Hbmass at age 16 yr was 13.24 ± 0.89 g·kg LBM and increased by 0.74 ± 0.58 g·kg LBM (P < 0.01) from age 16 to 19 yr. There was a high correlation between Hbmass at age 16 and 19 yr (r = 0.77; P < 0.001). Plasma volume, blood volume, and V˙O2max were higher in athletes compared to controls (P < 0.05). Blood volume and V˙O2max increased with age (P < 0.01, similarly in both groups).

Conclusions: Endurance training volumes do not explain individual differences in Hbmass levels nor Hbmass and V˙O2max development in the age period from 16 to 19 yr. The higher V˙O2max levels of athletes may be partially explained by training-induced higher plasma and blood volumes, as well as other training adaptations. Since Hbmass at age 16 yr varies substantially and the development of Hbmass in late adolescence is comparably small and not influenced by endurance training, Hbmass at age 16 yr is an important predictor for Hbmass at adult age and possibly for the aptitude for high-level endurance performance.
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http://dx.doi.org/10.1249/MSS.0000000000001867DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6493676PMC
May 2019

Differential Associations Among PTSD and Complex PTSD Symptoms and Traumatic Experiences and Postmigration Difficulties in a Culturally Diverse Refugee Sample.

J Trauma Stress 2018 12 15;31(6):795-804. Epub 2018 Nov 15.

Department of Psychology, University of Zurich, Zurich, Switzerland.

Forced migration is one of the major challenges currently facing the international community. Many refugees have been affected by traumatic experiences at home and during their flight, putting them at a heightened risk of developing trauma-related disorders. The new version of the International Classification of Diseases (ICD-11) introduced two sibling disorders, posttraumatic stress disorder (PTSD) and complex PTSD (CPTSD). So far, little is known about risk and protective factors in refugees that are specifically associated with the disturbances in self-organization (DSO) characteristic of CPTSD. In this study, we aimed to investigate the association between PTSD and DSO symptoms and traumatic experiences, postmigration difficulties, and social support in a culturally diverse sample of refugees who resettled in Switzerland. A total of 94 refugees (85.1% male; M age = 31.60 years, SD = 10.14, range: 18-61 years) participated in this study. Trained assessors performed either guided questionnaire assessments or structured interviews. In our advice- and help-seeking sample, 32.9% of individuals suffered from PTSD and 21.3% from CPTSD. After controlling for potential gender differences, we found positive associations between PTSD symptoms and trauma exposure, β = .22, as well as between DSO symptoms and postmigration living difficulties, β = .42, and lack of social support, β = .22. Our findings support the notion that it is highly important to consider differential associations among PTSD and DSO symptoms and risk and protective factors to gain a deeper understanding of the trauma-related problems refugees face.
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http://dx.doi.org/10.1002/jts.22342DOI Listing
December 2018

Amine-Borane Dehydrogenation and Transfer Hydrogenation Catalyzed by α-Diimine Cobaltates.

Chemistry 2019 Jan 11;25(1):238-245. Epub 2018 Dec 11.

Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany.

Anionic α-diimine cobalt complexes, such as [K(thf) {( BIAN)Co(η -cod)}] (1; Dipp=2,6-diisopropylphenyl, cod=1,5-cyclooctadiene), catalyze the dehydrogenation of several amine-boranes. Based on the excellent catalytic properties, an especially effective transfer hydrogenation protocol for challenging olefins, imines, and N-heteroarenes was developed. NH BH was used as a dihydrogen surrogate, which transferred up to two equivalents of H per NH BH . Detailed spectroscopic and mechanistic studies are presented, which document the rate determination by acidic protons in the amine-borane.
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http://dx.doi.org/10.1002/chem.201804811DOI Listing
January 2019

Tight regulation of FOXO1 is essential for maintenance of B-cell precursor acute lymphoblastic leukemia.

Blood 2018 06 5;131(26):2929-2942. Epub 2018 Apr 5.

Institute of Physiological Chemistry, University of Ulm, Ulm, Germany.

The FOXO1 transcription factor plays an essential role in the regulation of proliferation and survival programs at early stages of B-cell differentiation. Here, we show that tightly regulated FOXO1 activity is essential for maintenance of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Genetic and pharmacological inactivation of FOXO1 in BCP-ALL cell lines produced a strong antileukemic effect associated with CCND3 downregulation. Moreover, we demonstrated that CCND3 expression is critical for BCP-ALL survival and that overexpression of CCND3 protected BCP-ALL cell lines from growth arrest and apoptosis induced by FOXO1 inactivation. Most importantly, pharmacological inhibition of FOXO1 showed antileukemia activity on several primary, patient-derived, pediatric ALL xenografts with effective leukemia reduction in the hematopoietic, lymphoid, and central nervous system organ compartments, ultimately leading to prolonged survival without leukemia reoccurrence in a preclinical in vivo model of BCP-ALL. These results suggest that repression of FOXO1 might be a feasible approach for the treatment of BCP-ALL.
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http://dx.doi.org/10.1182/blood-2017-10-813576DOI Listing
June 2018

Predicting biathlon shooting performance using machine learning.

J Sports Sci 2018 Oct 22;36(20):2333-2339. Epub 2018 Mar 22.

a Swiss Federal Institute of Sport , Section for Elite Sport , Magglingen , Switzerland.

Shooting in biathlon competitions substantially influences final rankings, but the predictability of hits and misses is unknown. The aims of the current study were A) to explore factors influencing biathlon shooting performance and B) to predict future hits and misses. We explored data from 118,300 shots from 4 seasons and trained various machine learning models before predicting 34,340 future shots (in the subsequent season). A) Lower hit rates were discovered in the sprint and pursuit disciplines compared to individual and mass start (P < 0.01, h = 0.14), in standing compared to prone shooting (P < 0.01, h = 0.15) and in the 1 prone and 5 standing shot (P < 0.01, h = 0.08 and P < 0.05, h = 0.05). B) A tree-based boosting model predicted future shots with an area under the ROC curve of 0.62, 95% CI [0.60, 0.63], slightly outperforming a simple logistic regression model and an artificial neural network (P < 0.01). The dominant predictor was an athlete's preceding mode-specific hit rate, but a high degree of randomness persisted, which complex models could not substantially reduce. Athletes should focus on overall mode-specific hit rates which epitomise shooting skill, while other influences seem minor.
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http://dx.doi.org/10.1080/02640414.2018.1455261DOI Listing
October 2018

Identification of candidate effector genes of Pratylenchus penetrans.

Mol Plant Pathol 2018 Feb 9. Epub 2018 Feb 9.

Floral and Nursery Plants Research Unit, U.S. National Arboretum, U.S. Department of Agriculture, Beltsville, MD 20705-2350, USA.

Pratylenchus penetrans is one of the most important species of root lesion nematodes (RLNs) because of its detrimental and economic impact in a wide range of crops. Similar to other plant-parasitic nematodes (PPNs), P. penetrans harbours a significant number of secreted proteins that play key roles during parasitism. Here, we combined spatially and temporally resolved next-generation sequencing datasets of P. penetrans to select a list of candidate genes aimed at the identification of a panel of effector genes for this species. We determined the spatial expression of transcripts of 22 candidate effectors within the oesophageal glands of P. penetrans by in situ hybridization. These comprised homologues of known effectors of other PPNs with diverse putative functions, as well as novel pioneer effectors specific to RLNs. It is noteworthy that five of the pioneer effectors encode extremely proline-rich proteins. We then combined in situ localization of effectors with available genomic data to identify a non-coding motif enriched in promoter regions of a subset of P. penetrans effectors, and thus a putative hallmark of spatial expression. Expression profiling analyses of a subset of candidate effectors confirmed their expression during plant infection. Our current results provide the most comprehensive panel of effectors found for RLNs. Considering the damage caused by P. penetrans, this information provides valuable data to elucidate the mode of parasitism of this nematode and offers useful suggestions regarding the potential use of P. penetrans-specific target effector genes to control this important pathogen.
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http://dx.doi.org/10.1111/mpp.12666DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6638058PMC
February 2018

Realization of a Hole-Doped Mott Insulator on a Triangular Silicon Lattice.

Phys Rev Lett 2017 Dec 27;119(26):266802. Epub 2017 Dec 27.

Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA.

The physics of doped Mott insulators is at the heart of some of the most exotic physical phenomena in materials research including insulator-metal transitions, colossal magnetoresistance, and high-temperature superconductivity in layered perovskite compounds. Advances in this field would greatly benefit from the availability of new material systems with a similar richness of physical phenomena but with fewer chemical and structural complications in comparison to oxides. Using scanning tunneling microscopy and spectroscopy, we show that such a system can be realized on a silicon platform. The adsorption of one-third monolayer of Sn atoms on a Si(111) surface produces a triangular surface lattice with half filled dangling bond orbitals. Modulation hole doping of these dangling bonds unveils clear hallmarks of Mott physics, such as spectral weight transfer and the formation of quasiparticle states at the Fermi level, well-defined Fermi contour segments, and a sharp singularity in the density of states. These observations are remarkably similar to those made in complex oxide materials, including high-temperature superconductors, but highly extraordinary within the realm of conventional sp-bonded semiconductor materials. It suggests that exotic quantum matter phases can be realized and engineered on silicon-based materials platforms.
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http://dx.doi.org/10.1103/PhysRevLett.119.266802DOI Listing
December 2017

Molecular epidemiology of Trichophyton quinckeanum - a zoophilic dermatophyte on the rise.

J Dtsch Dermatol Ges 2018 Jan;16(1):21-32

Laboratory for Medical Microbiology, Mölbis, Germany.

Background: Formerly only referred to as a subspecies (T. mentagrophytes var. quinckeanum), T. quinckeanum once again constitutes a distinct species according to the updated taxonomy of dermatophytes.

Patients And Methods: During routine diagnostic tests conducted at the Mycology Laboratory, Mölbis, Germany, between 11/2013 to 1/2017 (three years and three months), all specimens sent in were examined for T. quinckeanum. Molecular biology methods employed included: 1) DNA hybridization (PCR ELISA), 2) gene sequencing of the ITS region and TEF-1α, and 3) in some cases, MALDI-TOF mass spectrometry.

Results: Overall, 62 strains of T. quinckeanum were found. Sixty-eight percent of patients were female; 43 % were children and adolescents (≤ 19 years of age). Cats were a frequent source of infection. Sequencing of all 62 strains revealed a concordance of 100 % with T. quinckeanum sequences contained in the NCBI database. Isolates analyzed by MALDI-TOF mass spectrometry showed specific spectra.

Conclusions: In Germany, the zoophilic dermatophyte T. quinckeanum currently appears to be more prevalent than expected. T. quinckeanum strains were isolated from children and adults with dermatomycosis and tinea capitis. Sources of infection with T. quinckeanum include small rodents (mice), horses, and - remarkably commonly -  cats. Given that unequivocal morphological identification of this dermatophyte is not always possible, molecular methods have to be employed in the diagnosis.
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http://dx.doi.org/10.1111/ddg.13408DOI Listing
January 2018

Hoarding: Symptom oder Syndrom?

Authors:
Thomas Maier

Praxis (Bern 1994) 2017;106(10):539-544

1 Psychiatrie St. Gallen Nord, Wil.

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http://dx.doi.org/10.1024/1661-8157/a002679DOI Listing
July 2017

Accuracy of Cycling Power Meters against a Mathematical Model of Treadmill Cycling.

Int J Sports Med 2017 Jun 8;38(6):456-461. Epub 2017 May 8.

Section for Elite Sport, Swiss Federal Institute of Sport, Magglingen, Switzerland.

The aim of this study was to compare the accuracy among a high number of current mobile cycling power meters used by elite and recreational cyclists against a first principle-based mathematical model of treadmill cycling. 54 power meters from 9 manufacturers used by 32 cyclists were calibrated. While the cyclist coasted downhill on a motorised treadmill, a back-pulling system was adjusted to counter the downhill force. The system was then loaded 3 times with 4 different masses while the cyclist pedalled to keep his position. The mean deviation (trueness) to the model and coefficient of variation (precision) were analysed. The mean deviations of the power meters were -0.9±3.2% (mean±SD) with 6 power meters deviating by more than±5%. The coefficients of variation of the power meters were 1.2±0.9% (mean±SD), with Stages varying more than SRM (p<0.001) and PowerTap (p<0.001). In conclusion, current power meters used by elite and recreational cyclists vary considerably in their trueness; precision is generally high but differs between manufacturers. Calibrating and adjusting the trueness of every power meter against a first principle-based reference is advised for accurate measurements.
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http://dx.doi.org/10.1055/s-0043-102945DOI Listing
June 2017

Qualitative Video Analysis of Track-Cycling Team Pursuit in World-Class Athletes.

Int J Sports Physiol Perform 2017 Nov 22;12(10):1305-1309. Epub 2017 Dec 22.

Context: Track-cycling team pursuit (TP) is a highly technical effort involving 4 athletes completing 4 km from a standing start, often in less than 240 s. Transitions between athletes leading the team are obviously of utmost importance.

Purpose: To perform qualitative video analyses of transitions of world-class athletes in TP competitions.

Methods: Videos captured at 100 Hz were recorded for 77 races (including 96 different athletes) in 5 international track-cycling competitions (eg, UCI World Cups and World Championships) and analyzed for the 12 best teams in the UCI Track Cycling TP Olympic ranking. During TP, 1013 transitions were evaluated individually to extract quantitative (eg, average lead time, transition number, length, duration, height in the curve) and qualitative (quality of transition start, quality of return at the back of the team, distance between third and returning rider score) variables. Determination of correlation coefficients between extracted variables and end time allowed assessment of relationships between variables and relevance of the video analyses.

Results: Overall quality of transitions and end time were significantly correlated (r = .35, P = .002). Similarly, transition distance (r = .26, P = .02) and duration (r = .35, P = .002) were positively correlated with end time. Conversely, no relationship was observed between transition number, average lead time, or height reached in the curve and end time.

Conclusion: Video analysis of TP races highlights the importance of quality transitions between riders, with preferably swift and short relays rather than longer lead times for faster race times.
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http://dx.doi.org/10.1123/ijspp.2016-0596DOI Listing
November 2017

Reliability of the virtual elevation method to evaluate rolling resistance of different mountain bike cross-country tyres.

J Sports Sci 2018 Jan 9;36(2):156-161. Epub 2017 Feb 9.

a Swiss Federal Institute of Sport, Section for Elite Sport , Magglingen , Switzerland.

Although a low rolling resistance is advantageous in mountain bike cross-country racing, no studies have used the virtual elevation method to compare tyres from different manufacturers as used in international competitions so far. The aims of this study were to assess the reliability of this method, to compare the off-road rolling resistance between tyres and to calculate the influence on off-road speed. Nine 29-in. mountain bike cross-country tyres were tested on a course representing typical ground surface conditions 5 or 6 times. The coefficient of rolling resistance was estimated with the virtual elevation method by 3 investigators and corresponding off-road speeds were calculated. The virtual elevation method was highly reliable (typical error = 0.0006, 2.8%; limits of agreement <0.0005, r ≥ 0.98). The mean coefficient of rolling resistance was 0.0219 and differed from 0.0205 to 0.0237 (P < 0.001) between tyres. The calculated differences in off-road speed amounted to 2.9-3.2% (0% slope) and 2.3-2.4% (10% slope) between the slowest and the fastest tyre. The reliability of the method and the differences in rolling resistance between the tyres illustrate the value of testing tyres for important competitions on a representative ground surface using the virtual elevation method.
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http://dx.doi.org/10.1080/02640414.2017.1287935DOI Listing
January 2018