bluuebunny/crossref_metadata_2025_split huggingface dataset:
Volatile diterpene emission by two Mediterranean Cistaceae shrubs
Authors: Yáñez-Serrano A. M. , Fasbender L. , Kreuzwieser J. , Dubbert D. , Haberstroh S. , Lobo-do-Vale R. , Caldeira M. C. , Werner C. 
Published: April 2018

AbstractMediterranean vegetation emits a wide range of biogenic volatile organic compounds (BVOCs) among which isoprenoids present quantitatively the most important compound class. Here, we investigated the isoprenoid emission from two Mediterranean Cistaceae shrubs, Halimium halimifolium and Cistus ladanifer, under controlled and natural conditions, respectively. For the first time, diurnal emission patterns of the diterpene kaurene were detected in real-time by Proton-Transfer-Reaction-Time-of-Flight-Mass-Spectrometer. Kaurene emissions were strongly variable among H. halimifolium plants, ranging from 0.01 ± 0.003 to 0.06 ± 0.01 nmol m−2 s−1 in low and high emitting individuals, respectively. They were in the same order of magnitude as monoterpene (0.01 ± 0.01 to 0.11 ± 0.04 nmol m−2 s−1) and sesquiterpene (0.01 ± 0.01 to 0.52 nmol m−2 s−1) emission rates. Comparable range and variability was found for C. ladanifer under natural conditions. Labelling with 13C-pyruvate suggested that emitted kaurene was not derived from de novo biosynthesis. The high kaurene content in leaves, the weak relationship with ecophysiological parameters and the tendency of higher emissions with increasing temperatures in the field indicate an emission from storage pools. This study highlights significant emissions of kaurene from two Mediterranean shrub species, indicating that the release of diterpenes into the atmosphere should probably deserve more attention in the future.
UNG-1 and APN-1 are the major enzymes to efficiently repair 5-hydroxymethyluracil DNA lesions in C. elegans
Authors: Papaluca Arturo , Wagner J. Richard , Saragovi H. Uri , Ramotar Dindial 
Published: April 2018

AbstractIn Caenorhabditis elegans, two DNA glycosylases, UNG-1 and NTH-1, and two AP endonucleases, APN-1 and EXO-3, have been characterized from the base-excision repair (BER) pathway that repairs oxidatively modified DNA bases. UNG-1 removes uracil, while NTH-1 can remove 5-hydroxymethyluracil (5-hmU), an oxidation product of thymine, as well as other lesions. Both APN-1 and EXO-3 can incise AP sites and remove 3′-blocking lesions at DNA single strand breaks, and only APN-1 possesses 3′- to 5′-exonulease and nucleotide incision repair activities. We used C. elegans mutants to study the role of the BER pathway in processing 5-hmU. We observe that ung-1 mutants exhibited a decrease in brood size and lifespan, and an elevated level of germ cell apoptosis when challenged with 5-hmU. These phenotypes were exacerbated by RNAi downregulation of apn-1 in the ung-1 mutant. The nth-1 or exo-3 mutants displayed wild type phenotypes towards 5-hmU. We show that partially purified UNG-1 can act on 5-hmU lesion in vitro. We propose that UNG-1 removes 5-hmU incorporated into the genome and the resulting AP site is cleaved by APN-1 or EXO-3. In the absence of UNG-1, the 5-hmU is removed by NTH-1 creating a genotoxic 3′-blocking lesion that requires the action of APN-1.
Generation and annihilation time of magnetic droplet solitons
Authors: Hang Jinting , Hahn Christian , Statuto Nahuel , Macià Ferran , Kent Andrew D. 
Published: April 2018

AbstractMagnetic droplet solitons were first predicted to occur in materials with uniaxial magnetic anisotropy due to a long-range attractive interaction between elementary magnetic excitations, magnons. A non-equilibrium magnon population provided by a spin-polarized current in nanocontacts enables their creation and there is now clear experimental evidence for their formation, including direct images obtained with scanning x-ray transmission microscopy. Interest in magnetic droplets is associated with their unique magnetic dynamics that can lead to new types of high frequency nanometer scale oscillators of interest for information processing, including in neuromorphic computing. However, there are no direct measurements of the time required to nucleate droplet solitons or their lifetime–experiments to date only probe their steady-state characteristics, their response to dc spin-currents. Here we determine the timescales for droplet annihilation and generation using current pulses. Annihilation occurs in a few nanoseconds while generation can take several nanoseconds to a microsecond depending on the pulse amplitude. Micromagnetic simulations show that there is an incubation time for droplet generation that depends sensitively on the initial magnetic state of the nanocontact. An understanding of these processes is essential to utilizing the unique characteristics of magnetic droplet solitons oscillators, including their high frequency, tunable and hysteretic response.
Recent climate warming drives ecological change in a remote high-Arctic lake
Authors: Woelders Lineke , Lenaerts Jan T. M. , Hagemans Kimberley , Akkerman Keechy , van Hoof Thomas B. , Hoek Wim Z. 
Published: April 2018

AbstractThe high Arctic is the fastest warming region on Earth, evidenced by extreme near-surface temperature increase in non-summer seasons, recent rapid sea ice decline and permafrost melting since the early 1990’s. Understanding the impact of climate change on the sensitive Arctic ecosystem to climate change has so far been hampered by the lack of time-constrained, high-resolution records and by implicit climate data analyses. Here, we show evidence of sharp growth in freshwater green algae as well as distinct diatom assemblage changes since ~1995, retrieved from a high-Arctic (80 °N) lake sediment record on Barentsøya (Svalbard). The proxy record approaches an annual to biennial resolution. Combining remote sensing and in-situ climate data, we show that this ecological change is concurrent with, and is likely driven by, the atmospheric warming and a sharp decrease in the length of the sea ice covered period in the region, and throughout the Arctic. Moreover, this research demonstrates the value of palaeoclimate records in pristine environments for supporting and extending instrumental records. Our results reinforce and extend observations from other sites that the high Arctic has already undergone rapid ecological changes in response to on-going climate change, and will continue to do so in the future.
Allosteric modulation of the farnesoid X receptor by a small molecule
Authors: Gabler Matthias , Kramer Jan , Schmidt Jurema , Pollinger Julius , Weber Julia , Kaiser Astrid , Löhr Frank , Proschak Ewgenij , Schubert-Zsilavecz Manfred , Merk Daniel 
Published: April 2018

AbstractThe bile acid activated transcription factor farnesoid X receptor (FXR) regulates numerous metabolic processes and is a rising target for the treatment of hepatic and metabolic disorders. FXR agonists have revealed efficacy in treating non-alcoholic steatohepatitis (NASH), diabetes and dyslipidemia. Here we characterize imatinib as first-in-class allosteric FXR modulator and report the development of an optimized descendant that markedly promotes agonist induced FXR activation in a reporter gene assay and FXR target gene expression in HepG2 cells. Differential effects of imatinib on agonist-induced bile salt export protein and small heterodimer partner expression suggest that allosteric FXR modulation could open a new avenue to gene-selective FXR modulators.
Structural Evolution of Hydrothermally Derived Reduced Graphene Oxide
Authors: Huang Hsin-Hui , De Silva K. Kanishka H. , Kumara G. R. A. , Yoshimura Masamichi 
Published: April 2018

AbstractHydrothermal reduction is a promising approach for graphene oxide (GO) reduction since it is environmentally friendly, simple, and cost effective. We present a detailed study of structural changes occurring in graphene oxide during the reduction process. The correlations between the interlayer spacing, chemical states, work functions, surface morphology, level of disorders, the number of layers, and processing time are elucidated. The results reveal that GO flakes remain in the early stage of the reduction process and that they are fully reduced after a 4-h hydrothermal treatment. With an increase in the reduction time, the resulting product, i.e., reduced graphene oxide, has a low oxygen content, small interlayer spacing, and crumbled and wrinkled structures. We are convinced that these properties can be tuned to a desired level for various applications.
A randomized, double-blind, placebo-controlled trial on the efficacy of ginger in the prevention of abdominal distention in post cesarean section patients
Authors: Tianthong Wasinee , Phupong Vorapong 
Published: April 2018

AbstractThe objective of the study was to evaluate the efficacy of ginger in the prevention of abdominal distention in post cesarean section patients. A randomized, double-blind, placebo controlled trial was conducted. One hundred and seventy-eight post cesarean section patients were either randomized to the study group receiving oral ginger capsules or to the placebo group receiving oral placebo capsules. The average age of the studied women was 32.3 years. The incidence of postoperative abdominal distention was not different between the ginger and the placebo groups (20.2% vs 29.2%, p = 0.328). The efficacy to relieve abdominal distention was superior in the ginger group than the placebo group (91% vs 65.2%, p < 0.001). With regards to quality of life, the number of patients who had the ability to eat was higher in the ginger group than in the placebo group (59.6% vs 43.8%, p = 0.035). There were no significant differences in time to first flatus, maternal satisfaction, and side effects. Ginger does not decrease the incidence of post cesarean section abdominal distention. But, ginger is more effective than the placebo in relieving the severity of abdominal distention on the fourth day after operation and improving the ability to eat.
Predicting drug resistance related to ABC transporters using unsupervised Consensus Self-Organizing Maps
Authors: Estrada-Tejedor Roger , Ecker Gerhard F. 
Published: April 2018

AbstractATP binding cassette (ABC) transporters play a pivotal role in drug elimination, particularly on several types of cancer in which these proteins are overexpressed. Due to their promiscuous ligand recognition, building computational models for substrate classification is quite challenging. This study evaluates the use of modified Self-Organizing Maps (SOM) for predicting drug resistance associated with P-gp, MPR1 and BCRP activity. Herein, we present a novel multi-labelled unsupervised classification model which combines a new clustering algorithm with SOM. It significantly improves the accuracy of substrates classification, catching up with traditional supervised machine learning algorithms. Results can be applied to predict the pharmacological profile of new drug candidates during the drug development process.
Zinc use efficiency is enhanced in wheat through nanofertilization
Authors: Dapkekar Ashwin , Deshpande Paresh , Oak Manoj D. , Paknikar Kishore M. , Rajwade Jyutika M. 
Published: April 2018

AbstractFerti-fortification of wheat with zinc, an essential micronutrient is one of the strategies for combating ‘hidden hunger’ in a large proportion of people all over the world. During fertilization, application of large quantities of micronutrients often results in nutrient wastage and subsequent environmental pollution. Here, we report zinc complexed chitosan nanoparticles (Zn-CNP) for ferti-fortification of durum wheat in field-scale experiments. The efficacy of Zn-CNP was assessed vis-à-vis conventionally applied ZnSO4 (0.2%; 400 mgL−1 zinc) in two durum wheat genotypes (MACS 3125, an indigenous high yielding genotype and UC 1114, a genotype containing the Gpc-B1gene). The observed grain zinc enrichment using Zn-CNP nanocarrier (~36%) and conventional ZnSO4 (~50%) were comparable, despite 10 folds less zinc (40 mgL−1) used in the former. Nanofertilizer application increased grain zinc content without affecting grain yield, protein content, spikelets per spike, thousand kernel weight, etc. Grain zinc enrichment observed in the four-year field trials on plots with varying soil zinc content was consistent, proving the utility of Zn-CNP as a novel nanofertilizer which enhanced fertilizer use efficiency. Our work describes a new paradigm in micronutrient fortification, viz. ‘use nanofertilizers at the right place, right time and in right doses’.
Local structure of molten AuGa2 under pressure: Evidence for coordination change and planetary implications
Authors: Kalkan Bora , Godwal Budhiram , Raju Selva Vennila , Jeanloz Raymond 
Published: April 2018

AbstractIn situ x-ray diffraction measurements and inverse Monte Carlo simulations of pair distribution functions were used to characterize the local structure of molten AuGa2 up to 16 GPa and 940 K. Our results document systematic changes in liquid structure due to a combination of bond compression and coordination increase. Empirical potential structure refinement shows the first-neighbor coordination of Ga around Au and of Au around Ga to increase from about 8 to 10 and 4 to 5, respectively between 0 and 16 GPa, and the inferred changes in liquid structure can explain the observed melting-point depression of AuGa2 up to 5 GPa. As intermetallic AuGa2 is an analogue for metallic SiO2 at much higher pressures, our results imply that structural changes documented for non-metallic silicate melts below 100 GPa are followed by additional coordination changes in the metallic state at pressures in the 0.2–1 TPa range achieved inside large planets.
Self‐assembled 3D NiCo2S4 nanotubes‐graphene aerogel composites as an excellent anode for Li‐ion batteries
Authors: Zhang Lixin , Wang Qi , Jiu Hongfang , Xie Chunmei , Zhang Shaomei 
Published: April 2018

Three‐dimensional nickel cobalt sulphide (NiCo2S4) nanotubes‐graphene aerogel composites (NGAs) are firstly assembled by an electrostatic interaction between the diallyldimethylammonium chloride‐modified NiCo2S4 nanotubes and graphene oxide (GO) sheets, followed by a steerable hydrothermal and freeze‐drying process. The final samples are characterised by scanning electron microscope, transmission electron microscopy, X‐ray diffraction and Brunauer–Emmett–Teller. The results reveal that the NiCo2S4 nanotubes with a uniform diameter of about 200 nm tightly anchor onto the crumpled surface of graphene sheets and GO sheets self‐assemble into an interconnected porous structure. When the composites are evaluated as an anode for lithium‐ion batteries (LIBs), presenting an extremely admirable cycling stability (967.5 mAh g−1 after 100 cycles at a current density of 100 mA g−1) and excellent rate capability (as high as 654.7 mAh g−1 at a large rate of at 2000 mA g−1). This work proved that the NGAs may have a great application in LIBs.
Variability of the adiabatic parameter in monoatomic thermal and non-thermal plasmas
Authors: de Avillez Miguel A. , Anela Gervásio J. , Breitschwerdt Dieter 
Published: April 2018

Context. Numerical models of the evolution of interstellar and integalactic plasmas often assume that the adiabatic parameter γ (the ratio of the specific heats) is constant (5/3 in monoatomic plasmas). However, γ is determined by the total internal energy of the plasma, which depends on the ionic and excitation state of the plasma. Hence, the adiabatic parameter may not be constant across the range of temperatures available in the interstellar medium.
Aims. We aim to carry out detailed simulations of the thermal evolution of plasmas with Maxwell–Boltzmann and non-thermal (κ and n) electron distributions in order to determine the temperature variability of the total internal energy and of the adiabatic parameter.
Methods. The plasma, composed of H, He, C, N, O, Ne, Mg, Si, S, and Fe atoms and ions, evolves under collisional ionization equilibrium conditions, from an initial temperature of 109 K. The calculations include electron impact ionization, radiative and dielectronic recombinations and line excitation. The ionization structure was calculated solving a system of 112 linear equations using the Gauss elimination method with scaled partial pivoting. Numerical integrations used in the calculation of ionization and excitation rates are carried out using the double-exponential over a semi-finite interval method. In both methods a precision of 10−15 is adopted.
Results. The total internal energy of the plasma is mainly dominated by the ionization energy for temperatures lower than 8 × 104 K with the excitation energy having a contribution of less than one percent. In thermal and non-thermal plasmas composed of H, He, and metals, the adiabatic parameter evolution is determined by the H and He ionizations leading to a profile in general having three transitions. However, for κ distributed plasmas these three transitions are not observed for κ < 15 and for κ < 5 there are no transitions. In general, γ varies from 1.01 to 5/3. Lookup tables of the γ parameter are presented as supplementary material.
The effect of the ionosphere on ultra-low-frequency radio-interferometric observations
Authors: de Gasperin F. , Mevius M. , Rafferty D. A. , Intema H. T. , Fallows R. A. 
Published: April 2018

Context. The ionosphere is the main driver of a series of systematic effects that limit our ability to explore the low-frequency (<1 GHz) sky with radio interferometers. Its effects become increasingly important towards lower frequencies and are particularly hard to calibrate in the low signal-to-noise ratio (S/N) regime in which low-frequency telescopes operate.
Aims. In this paper we characterise and quantify the effect of ionospheric-induced systematic errors on astronomical interferometric radio observations at ultra-low frequencies (<100 MHz). We also provide guidelines for observations and data reduction at these frequencies with the LOw Frequency ARray (LOFAR) and future instruments such as the Square Kilometre Array (SKA).
Methods. We derive the expected systematic error induced by the ionosphere. We compare our predictions with data from the Low Band Antenna (LBA) system of LOFAR.
Results. We show that we can isolate the ionospheric effect in LOFAR LBA data and that our results are compatible with satellite measurements, providing an independent way to measure the ionospheric total electron content (TEC). We show how the ionosphere also corrupts the correlated amplitudes through scintillations. We report values of the ionospheric structure function in line with the literature.
Conclusions. The systematic errors on the phases of LOFAR LBA data can be accurately modelled as a sum of four effects (clock, ionosphere first, second, and third order). This greatly reduces the number of required calibration parameters, and therefore enables new efficient calibration strategies.
Erster epileptischer Anfall im erwerbsfähigen Alter: Prognose-adaptiertes Management
Authors: Specht Ulrich , Bien Christian 
Published: April 2018

Zusammenfassung
Hintergrund Die Frage des angemessenen Managements nach einem ersten epileptischen Anfall verursacht nicht selten Unsicherheit. Dies betrifft vier Themenbereiche: die Diagnostik; die Einschätzung des Rezidivrisikos; die Beratung des Patienten bezüglich einer antiepileptischen Pharmakotherapie sowie deren weiterer ärztlicher Begleitung; und die sozialmedizinische Bewertung (Fahreignung, berufliche Eignung).
Methodik Zusammenfassung der relevanten Datenlage zu diesen Themenfeldern und daraus abgeleitete Empfehlungen zum praktischen Umgang mit ersten epileptischen Anfällen im erwerbsfähigen Alter.
Ergebnis Nach der Klärung, ob es sich um einen epileptischen Anfall gehandelt hat, dient die Diagnostik einerseits dazu, akut-symptomatische und potenziell behandlungsbedürftige Ursachen zu erkennen, andererseits zur Abschätzung des Rezidivrisikos. Dieses hängt weniger davon ab, ob eine Epilepsie diagnostiziert werden kann. Risikoerhöhend sind vielmehr – auch additiv – das Vorliegen folgender Merkmale: epilepsietypische Aktivität im EEG, bildgebender Nachweis einer Hirnläsion, zerebrale Vorerkrankung oder Auftreten des Anfalls aus dem Schlaf. Je höher das Rezidivrisiko, desto stärker scheint der rezidivprophylaktische Effekt einer antiepileptischen Pharmakotherapie zu sein und desto eher wird man dafür optieren. Die Entscheidung hierüber wird gemeinsam mit dem Patienten getroffen unter Berücksichtigung seiner Präferenzen und seiner sozialen Situation (z. B. Angewiesensein auf die Fahreignung, berufliche Besonderheiten). In der weiteren Begleitung kommt der Sicherung der Adhärenz eine entscheidende Rolle zu. Für die Frist bis zur Wiedererlangung der Fahreignung und der Eignung, bestimmte berufliche Tätigkeiten (wieder) auszuüben, gibt es verbindliche Regelungen.
Fallbericht einer steroidsensitiven, mit Mycoplasma pneumoniae assoziierten, schweren Autoimmunenzephalitis beim Erwachsenen
Authors: Hildebrand Jacob , Sliwka Ulrich 
Published: April 2018

ZusammenfassungEin 51-jähriger Patient wird uns mit rechtshemisphärisch betontem, enzephalitischem Syndrom mit Somnolenz, Apathie, Hemiparese links und Dysarthrie vorgestellt. Zuvor war der Patient stationär bis 2 Tage vorher wegen einer Mykoplasmenpneumonie behandelt worden, die zur Aufnahme bei uns klinisch wie laborchemisch ausbehandelt war. Im Voraufenthalt war ein durchgeführtes cMRT ohne pathologischen Befund. Das cMRT bei uns bildete eine enzephalitische Läsionslast im Marklager beidseits und links betont ab. Im Liquor war eine Eiweißerhöhung auf 78,8 mg/dl bei 13 Zellen/µl vorhanden. Im Verlauf trafen positive IgG-ASIs für Mycoplasma pneumoniae-Antikörper sowie schwach positiven Antikörpern für Borrelien IgM bei negativen Borrelien ASIs und sonst nicht pathologischer Antikörperserologie ein. Der Patient kam mit einer gerade abgeschlossenen Doxycyclintherapie. Eine dreitätige Cortisonstoßtherapie mit 1 g Methylprednisolon erbrachte eine deutliche Beschwerdebesserung, weshalb sie auf 6 Tage Gesamtdauer verlängert wurde. Eine anschließende, pragmatische Therapie mit Ceftriaxon brachte keine weitere Besserung. Leider wurden nicht ausreichend viele der zu dem Zeitpunkt bekannten Autoimmunenzephalitis-Antikörper bei diesem Patienten angefordert. Drei Monate nach Aufnahme bei uns zeigen sich nur noch minimale Läsionen im cMRT im Kern der vorher erheblichen betroffenen Areale. Der Patient wurde anschließend stationär rehabilitiert und ist jetzt wieder in seinem alten handwerklichen Beruf tätig. Die deutliche klinische Besserung unter Steroidgabe spricht für eine Autoimmunenzephalitis. Eine konkurrierende Diagnose ist eine akute, disseminierte Enzephalomyelitis (ADEM). Bemerkenswert ist die Assoziation mit einer Mykoplasmenpneumonie und entsprechender intrathekaler Antikörpersynthese gegen Mykoplasmen. Nach unserem Wissen wäre dies die erste beschriebene mit Mycoplasma pneumoniae assoziierte Autoimmunenzephalitis des Erwachsenen.