bluuebunny/crossref_metadata_2025_split huggingface dataset:
A further insight into methyltestosterone metabolism: New evidences from in vitro and in vivo experiments
Authors: Martinez‐Brito Dayamin , Iannone Michele , Tatangelo Maria Antonietta , Molaioni Francesco , de la Torre Xavier , Botrè Francesco 
Published: June 2020

RationaleAlthough the metabolism of methyltestosterone (MT) has been extensively studied since the 1950s using different techniques, the aim of this study was to investigate the hydroxylation in positions C2, C4 and C6 after in vitro experiments and in vivo excretion studies using gas chromatography time‐of‐flight (GC/TOF) and gas chromatography/tandem mass spectrometry (GC/MS/MS). The results could be influenced by the mass spectrometric analyser used.MethodsIncubations were carried out with human liver microsomes and six enzymes belonging to the cytochrome P450 family using MT as a substrate. The trimethylsilyl derivatives of the samples were analysed using GC/TOF and GC/MS/MS once the correct MS/MS transitions had been selected, mainly for 6‐hydroxymethyltestosterone (6‐OH‐MT) to avoid artefact interferences. A urinary excretion study was then performed after the administration of a 10 mg single oral dose of MT to a volunteer.ResultsThe formation of hydroxylated metabolites of MT in the C6, C4 and C2 positions after both in vitro and in vivo experiments was observed. Sample evaluation using GC/TOF showed an interference for 6‐OH‐MT that could only be resolved in GC/MS/MS by monitoring specific transitions. The transitory detection of these hydroxylated metabolites in urine agrees with previous investigations that had described this metabolic route as being of little significance.ConclusionsIn doping analysis, the formation of 4‐hydroxymethyltestosterone (oxymesterone) from MT cannot be underestimated. Although it is only detected as a minor and short‐term excretion metabolite, it cannot be overlooked as it was found in both in vitro and in vivo experiments. The use of a combination of different mass spectrometric instruments allowed reliable conclusions to be reached, and it was shown that special attention must be given to artefact formation.
Effect of Ball Milling and Oxidation on Dispersibility and Dispersion Stability of Multiwalled Carbon Nanotubes in High Viscous Heat Exchange Fluids
Authors: Vishal Chachin , Raju Chinthalapati Siva Kesava , Krishna Kanala Raghava , Raman Ravishankar , Rao Bojja Ramachandra , Kanaparthi Ramesh 
Published: June 2020

AbstractMultiwalled carbon nanotubes (MWCNTs) tend to agglomerate resulting in poor dispersion in most of the common solvents due to possessing long tubular structure, high Vander Waal force of attractions and poor interfacial interactions with the surrounding matrix. To improve the dispersion stability, MWCNT, were subjected to ball milling with 300 rpm for 1 h to reduce the length of the MWCNT to improve the functional groups to the MWCNT wall during chemical functionalization. MWCNTs were subjected to thermal oxidation in air at different temperatures before acid treatment to remove the amorphous carbon from MWCNT. Morphology studies of MWCNTs nanofluids were carried out by using a SEM and TEM methods to characterize the surface deformity of MWCNT structure and extent of defect formation, respectively. FT IR and XRD methods were used for the identification of different functional groups and crystalline nature of pristine, ball milled and oxidized MWCNT, respectively. Raman spectroscopy was applied to measure the relative intensities (ID/IG) to estimate the defect ratios. Preparation of nanofluid by dispersing high defect ratio MWCNTs with a concentration of 100 ppm in the base fluid by the ultra‐sonication method. Nanofluids dispersion stability and cycle stability were studied by using UV‐Visible spectroscopy and MWCNTs treated with combined ball milling and oxidation method have exhibited high stability and high dispersibility.
Novel γ‐Al2O3 Supported Low Concentrated Pd Nanoalloy Catalyst for Improved Hydrogenation Ability of 2‐Methylfuran
Authors: Shang Fangfang , Yu Haoxuan , Chu Qingyan , Yang Haiyu , Wang Ping , Cui Hongyou , Wang Ming 
Published: June 2020

AbstractPd−Al was constructed to deal with the issue that cyclic unsaturated compounds are unstable in hydrogenation reaction. Hydrogenation of 2‐methylfuran as a probe reaction in the fixed‐bed reactor afforded up to 99.9% yield and 100% chemo‐selectivity requiring only 100 °C and 2 MPa pressure. Compared with the previous hydrogenation catalyst, such as Ni based catalyst, Pd−Al nanoalloy catalyst employs better performance. Enhancement of catalytic activity, selectivity and stability was attributed to the construction of nano‐effect and Pd−Al alloy structure with low loading amount of Pd. Furthermore, Pd−Al nanoalloy catalyst presented excellent catalytic stability in hydrogenation reaction running for 150 h. Finally, a feasible mechanism of the reaction was proposed and proved by collecting intermediate.
Preparation of Maleimide‐Based Enediynes with Propargyl Ester for Efficient Tumor Cell Suppression
Authors: Chen Huimin , Li Baojun , Zhang Mengsi , Lu Haotian , Wang Yue , Wang Wenbo , Ding Yun , Hu Aiguo 
Published: June 2020

AbstractAcyclic enediynes are much easier to be synthesized comparing to natural or synthetic cyclic enediynes. However, the conditions for their thermal reactions to produce free radicals through Bergman cyclization (BC) are typically demanding, limiting their applications as antitumor agents. On the other hand, the acyclic compounds with enyne‐allene structures prone to proceed through Myers‐Saito cyclization (MCS) under much milder conditions. Therefore, it is vital to design acyclic enediynes which can permit propargyl‐allenyl rearrangement and then undergo MSC at low temperature for antitumor applications. In this work, we synthesized a series of maleimide‐based enediyne compounds with propargyl ester functionalities. The facile propargyl‐allenyl tautomerization assisted by the maleimide group enabled the formation of enyne‐allene structures and the subsequent occurrence of MSC. The generation of free radicals, which further raised the reactive oxygen species level in physiological environments, was confirmed by electron paramagnetic resonance analysis. The highly reactive radicals showed excellent DNA‐cleaving ability as confirmed with DNA gel electrophoresis. In addition, this kind of acyclic enediynes effectively inhibited the proliferation of HeLa cells with half inhibition concentration down to submicromolar level, comparable or even superior to many clinically used antitumor agents, showing promising application aspect.
Gluconate‐Stabilized Silver Nanoparticles as pH Dependent Dual‐Nanosensor for Quantitative Evaluation of Methionine and Cysteine
Authors: Khan Shamim Ahmed , Choudhury Rupasree , Majumdar Moumita , Nandi Nishithendu Bikash , Roy Shaktibrata , Misra Tarun Kumar 
Published: June 2020

AbstractSilver nanoparticles (AgNPs) based naked‐eye and spectrophotometric dual‐nanosensor for two most important biothiols: methionine and cysteine would be highly useful for an analyst. We have explored potential use of gluconate‐stabilized AgNPs (Glu‐AgNPs) for such unique purpose. Simply, aggregation of Glu‐AgNPs by the analyte, methionine/cysteine technique was adopted. Gluconate ions make the AgNPs anionic in nature. The anionic Glu‐AgNPs, as a pH‐ dependent nanosensor are selective to sensing methionine and cysteine over other amino acids in aqueous solution. By tuning pH of the particles’ solution we have at different demonstrated that the equilibria components of methionine/cysteine at different pH may play guiding roles in aggregating the particles, consequently in selectivity and sensitivity of the nanosensor. The LOL, LOQ, and LOD for methionine are 42, 9.89 and 2.97 μM, and for cysteine are 1.4, 0.49 and 0.14 μM, respectively. The interactions of cysteine (Kasso, 3.07x105 M−1) with the anionic Glu‐AgNPs are greater than that of methionine (Kasso, 1.635x104 M−1). Overall, the recovery results from the real samples: urine, blood serum and aCsF are excellent, which may make the developed nanosensor attractive to an analyst.
Peroxy‐Benzoic Acid Mediated Domino C[sp2] Hydroxylation /Annulation of Enaminones for the Synthesis of 3‐Hydroxy Chromones
Authors: Gudipati Ramakrishna , Kandula Venu , Raghavulu K. , Basavaiah K. , Yennam Satyanarayana , Behera Manoranjan 
Published: June 2020

AbstractAn efficient, facile, and clean synthesis of various 3‐hydroxy‐chromones (3‐hydroxy‐4H‐chromene‐4‐ones) via enamino ketone followed by cyclization using m‐chloroperbenzoic acid (MCPBA) has been described. The significant features of this method include simple method, high purity and excellent regio‐selectivity of the products. This is the first report for the two step one pot synthesis of 3‐hydroxyl chromone using MCPBA.
In Situ Grown Single‐Atom Cobalt on Polymeric Carbon Nitride with Bidentate Ligand for Efficient Photocatalytic Degradation of Refractory Antibiotics
Authors: Yang Yang , Zeng Guangming , Huang Danlian , Zhang Chen , He Donghui , Zhou Chengyun , Wang Wenjun , Xiong Weiping , Song Biao , Yi Huan , Ye Shujing , Ren Xiaoya 
Published: June 2020

AbstractSemiconductor photocatalysis is a promising technology to tackle refractory antibiotics contamination in water. Herein, a facile in situ growth strategy is developed to implant single‐atom cobalt in polymeric carbon nitride (pCN) via the bidentate ligand for efficient photocatalytic degradation of oxytetracycline (OTC). The atomic characterizations indicate that single‐atom cobalt is successfully anchored on pCN by covalently forming the CoO bond and CoN bond, which will strengthen the interaction between single‐atom cobalt and pCN. This single‐atom cobalt can efficiently expand optical absorption, increase electron density, facilitate charge separation and transfer, and promote OTC degradation. As the optimal sample, Co(1.28%)pCN presents an outstanding apparent rate constant for OTC degradation (0.038 min−1) under visible light irradiation, which is about 3.7 times than that of the pristine pCN. The electron spin resonance (ESR) tests and reactive species trapping experiments demonstrate that the 1O2, h+, •O2−, and •OH are responsible for OTC degradation. This work develops a new way to construct single‐atom‐modified pCN and provides a green and highly efficient strategy for refractory antibiotics removal.
Spectral Field Campaigns: Planning and Data Collection
Authors: Schweiger Anna K. 
Published: June 2020

AbstractThis chapter focuses on planning field campaigns and data collection relevant to plant biodiversity. Particular emphasis is placed on sampling spectra of plants across scales, from the leaf to the canopy and airborne level, considering the issue of matching ecological data with spectra. The importance of planning is highlighted from the perspective of the long-term sustainability of a project, which includes using and contributing to the development of standards for project documentation and archiving. These issues are critical to biodiversity researchers involved in data collection in situ and via remote sensing (RS).
The monodromy groups of lisse sheaves and overconvergent F-isocrystals
Authors: D’Addezio Marco 
Published: June 2020

AbstractIt has been proven by Serre, Larsen–Pink and Chin, that over a smooth curve over a finite field, the monodromy groups of compatible semi-simple pure lisse sheaves have “the same” $$\pi _0$$

π
0

and neutral component. We generalize their results to compatible systems of semi-simple lisse sheaves and overconvergent F-isocrystals over arbitrary smooth varieties. For this purpose, we extend the theorem of Serre and Chin on Frobenius tori to overconvergent F-isocrystals. To put our results into perspective, we briefly survey recent developments of the theory of lisse sheaves and overconvergent F-isocrystals. We use the Tannakian formalism to make explicit the similarities between the two types of coefficient objects.
Analyse der Spontanmotorik im 1. Lebensjahr: Markerlose 3-D-Bewegungserfassung zur Früherkennung von Entwicklungsstörungen
Authors: Parisi Carmen , Hesse Nikolas , Tacke Uta , Pujades Rocamora Sergi , Blaschek Astrid , Hadders-Algra Mijna , Black Michael J. , Heinen Florian , Müller-Felber Wolfgang , Schroeder A. Sebastian 
Published: June 2020

ZusammenfassungKinder mit motorischer Entwicklungsstörung profitieren von einer frühen Entwicklungsförderung. Eine frühe Diagnosestellung in der kinderärztlichen Vorsorge (U2–U5) kann durch ein automatisiertes Screening verbessert werden. Bisherige Ansätze einer automatisierten Bewegungsanalyse sind jedoch teuer und aufwendig und nicht in der Breite anwendbar. In diesem Beitrag soll ein neues System zur Videoanalyse, das Kinematic Motion Analysis Tool (KineMAT) vorgestellt werden. Es kann bei Säuglingen angewendet werden und kommt ohne Körpermarker aus. Die Methode wird anhand von 7 Patienten mit unterschiedlichen Diagnosen demonstriert.Mit einer kommerziell erhältlichen Tiefenbildkamera (RGB-D[Red-Green-Blue-Depth]-Kamera) werden 3‑minütige Videosequenzen von sich spontan bewegenden Säuglingen aufgenommen und mit einem virtuellen Säuglingskörpermodell (SMIL[Skinned Multi-infant Linear]-Modell) in Übereinstimmung gebracht. Das so erzeugte virtuelle Abbild erlaubt es, beliebige Messungen in 3‑D mit hoher Präzision durchzuführen. Eine Auswahl möglicher Bewegungsparameter wird mit diagnosespezifischen Bewegungsauffälligkeiten zusammengeführt.Der KineMAT und das SMIL-Modell erlauben eine zuverlässige, dreidimensionale Messung der Spontanaktivität bei Säuglingen mit einer sehr niedrigen Fehlerrate. Basierend auf maschinellen Lernalgorithmen kann der KineMAT trainiert werden, pathologische Spontanmotorik automatisiert zu erkennen. Er ist kostengünstig und einfach anzuwenden und soll als Screeninginstrument für die kinderärztliche Vorsorge weiterentwickelt werden.
Resistance of different wood-based materials against mould fungi: a comparison of methods
Authors: Imken Arne A.P. , Brischke Christian , Kögel Sebastian , Krause Kim C. , Mai Carsten 
Published: June 2020

AbstractWood-based materials are generally prone to colonization by mould fungi and other discoloring microorganisms, but their resistance to fungal discoloration varies. Different standardized test methods for determining the susceptibility to mould fungi have been used to evaluate various wood-based materials, but the obtained results suggest that mould resistance depends on the method applied. Therefore, this study aimed at a comparative evaluation of two commonly used methods for determining the mould resistance of wood-based materials, i.e. the chamber method according to BS 3900—Part G6 and the malt agar plate method according to ISO 16869. Solid wood, wood fiber insulation boards and wood polymer composites were inoculated, incubated for different time intervals, and assessed with regard to superficial mould growth. Mould growth ratings obtained with the two methods did not correlate well, neither within one type of material nor across different materials, which can be attributed to higher moisture contents and additional nutrients available for the specimens in the agar plate test compared to those in the chamber test. It was concluded, that the experimental set up could have an overriding effect on the results of mould resistance tests.
Development of a capillary electrophoresis–mass spectrometry method for the analysis of metformin and its transformation product guanylurea in biota
Authors: Knoll Sarah , Jacob Stefanie , Mieck Susanna , Triebskorn Rita , Braunbeck Thomas , Huhn Carolin 
Published: June 2020

AbstractA method with capillary electrophoresis coupled to mass spectrometry was optimized to determine the uptake of metformin and its metabolite guanylurea by zebrafish (Danio rerio) embryos and brown trout (Salmo trutta f. fario) exposed under laboratory conditions. Metformin was extracted from fish tissues by sonication in methanol, resulting in an absolute recovery of almost 90%. For the extraction of guanylurea from brown trout, solid-phase extraction was implemented with a recovery of 84%. The use of a mixture of methanol and glacial acetic acid as a non-aqueous background electrolyte was vital to achieve robust analysis using a bare fused-silica capillary with an applied voltage of +30 kV. Problems with adsorption associated with an aqueous background electrolyte were eliminated using a non-aqueous background electrolyte made of methanol/acetic acid (97:3) with 25 mM ammonium acetate (for zebrafish embryos) or 100 mM ammonium acetate (for brown trouts), depending on the sample complexity and matrix influences. High resolution and high separation selectivity from matrix components were achieved by optimization of the ammonium acetate concentration in the background electrolyte. An extensive evaluation of matrix effects was conducted with regard to the complex matrices present in the fish samples. They required adapting the background electrolyte to higher concentrations. Applying this method to extracts of zebrafish embryos and brown trout tissue samples, limits of detection for both metformin and guanylurea in zebrafish embryos (12.2 μg/l and 15 μg/l) and brown trout tissues (15 ng/g and 34 ng/g) were in the low μg/l or ng/g range. Finally, metformin and guanylurea could be both quantified for the first time in biota samples from exposure experiments.
Work above shoulder level and shoulder complaints: a systematic review
Authors: Wærsted Morten , Koch Markus , Veiersted Kaj Bo 
Published: June 2020

Abstract
Objective
To investigate the association and the exposure–response relationship between work above shoulder height and shoulder pain or disorders.

Methods
A systematic search was performed in Medline, Embase, and Health and Safety Science Abstracts. Included were articles with prospective cohort, case–control, cross-sectional, or intervention study designs. Quality assessment was based on an evaluation scheme adjusted to study design and normalized to 100%. The cut-off for sufficient quality to include articles was above 40% and cut-off for high-quality articles was above 50% of maximal score. The level of strength of evidence for an association between exposure and effect was assessed according to the GRADE guidelines.

Results
Thirty-four articles were included. Articles that document large effects (higher risk estimates; OR ≥ 2) have higher quality score, include analyses of severe arm elevation, more often use clinical outcome, and report an exposure–response relationship compared to studies reporting lower risk estimates. The studies that reported large effects were all significant.
An exposure–response relationship was found in many high-quality studies when relating exposure intensity of arm elevation (level of arm elevation, amplitude) as well as duration of arm elevation, especially > 90°.

Conclusion
We conclude on a limited evidence for an association between arm elevation at work and shoulder disorders. Severe arm elevation with elbows above shoulder level (i.e., > 90°) shows a moderate evidence for an association with shoulder disorders.
Evidence for 9R-SiC?
Authors: Kaiser U. , Chuvilin A. , Kyznetsov V. , Butenko Y. 
Published: June 2020

AbstractComplementary to our first paper on the origin of threefold contrast on SiC high resolution transmission electron microscopy (HRTEM) images, we now provide an example of threefold contrast produced by a stacking layer sequence which corresponds to one unit cell of the 9R polytype.
Scattering Cross Sections in Electron Microscopy and Analysis
Authors: Rez Peter 
Published: June 2020

AbstractThe scattering cross section is the fundamental measure of the strength of a scattering interaction. All scattering in electron microscopy arises from the Coulomb interaction, and scattering cross sections, whether elastic or inelastic, will therefore all have common features. Simple forms of both elastic and inelastic cross sections are reviewed in the context of high resolution and analytical microscopy. Some recent developments, such as the calculation of Fano resonances in electron energy loss spectra of transition metals and rare earth elements are also discussed.
Differential Image Distortion Correction
Authors: Pollak C. , Stubbings T. , Hutter H. 
Published: June 2020

AbstractImaging techniques often suffer from distortion effects. Former methods of reducing these distortions have been based either on improving the imaging technique (i.e., to avoid distortions) or on the use of reference samples (i.e., to determine the distortion field by imaging of a known structure. We present a novel method of correcting image distortion by evaluating the imaged position changes due to two small sample position shifts. The algorithm allows us to calculate a vector field, which enables us to determine the “undistorted” position of any point of the image. The presented method has very low presuppositions about the sample, requires no reference samples, and is applicable to any type of image distortion. In addition to the presentation of the method's theoretical basis and a description of the computational method, we present corrected secondary ion mass spectroscopy (SIMS) images of a regular structure (a copper grid) as well as a stochastic distribution (sodium impurities) to show the results of empirical data.
Electron Beam Current Loss at the High-Vacuum– High-Pressure Boundary in the Environmental Scanning Electron Microscope
Authors: Danilatos Gerasimos D. , Phillips Matthew R. , Nailon John V. 
Published: June 2020

AbstractA significant loss in electron probe current can occur before the electron beam enters the specimen chamber of an environmental scanning electron microscope (ESEM). This loss results from electron scattering in a gaseous jet formed inside and downstream (above) the pressure-limiting aperture (PLA), which separates the high-pressure and high-vacuum regions of the microscope. The electron beam loss above the PLA has been calculated for three different ESEMs, each with a different PLA geometry: an ElectroScan E3, a Philips XL30 ESEM, and a prototype instrument. The mass thickness of gas above the PLA in each case has been determined by Monte Carlo simulation of the gas density variation in the gas jet. It has been found that the PLA configurations used in the commercial instruments produce considerable loss in the electron probe current that dramatically degrades their performance at high chamber pressure and low accelerating voltage. These detrimental effects are minimized in the prototype instrument, which has an optimized thin-foil PLA design.
Design and Applications of Environmental Cell Transmission Electron Microscope for In Situ Observations of Gas–Solid Reactions
Authors: Sharma Renu 
Published: June 2020

AbstractThe environmental transmission electron microscopy (E-TEM) is a budding technique for in situ study of gas–solid chemical reactions with numerous applications. Recent improvements in the design have made it possible not only to obtain atomic level information but also the chemical information during the reaction by incorporating an imaging filter or electron energy-loss spectrometer to an E-TEM. We have been involved in modifying a couple of microscopes to incorporate environmental cells in order to convert them into E-TEMs. These microscopes have been used to obtain atomic level information of the structural and chemical changes during dynamic processes by in situ electron diffraction, high-resolution imaging, and electron energyloss spectroscopy. The applications include, but are not limited to, oxidation, reduction, polymerization, nitridation, dehydroxylation, hydroxylation, chemical vapor deposition, etc. We report recent developments in the design and application along with the limitations of an E-TEM.