bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing the CO2 Separation Performance of Matrimid 5218 Membranes for CO2/CH4 Binary Mixtures
Authors: Castro-Muñoz Roberto , Fíla Vlastimil , Ahmad Mohd Zamidi
Published: January 2019

The effect of CO2‐philic additive polyethylene glycol (PEG) 200 in Matrimid 5218 on the separation performance of prepared membranes was evaluated in a binary gas mixture. Matrimid/PEG 200 flat‐sheet blended membranes with low PEG concentrations were prepared by the dense film‐casting method. Pure Matrimid and blended membranes were characterized by FTIR spectroscopy, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and permeation measurements. The addition of 4–5 % of PEG enhanced considerably the CO2 permeability of the Matrimid matrix. The best formulation, Matrimid/PEG 200 (96/4), showed in comparison to pure Matrimid a more than threefold increase in CO2 permeability and an increase in separation factor of about 40 %.
Influence of Molecular Size on the Electrochemical Oxidation of Fractioned Cork Boiling Wastewater
Authors: Fernandes Annabel , Gomes Arlindo C. , Pereira Christopher , Magdziak Anna , Pacheco Maria J. , Ciríaco Lurdes , Simões Rogério , Lopes Ana
Published: January 2019

The performance of electrochemical oxidation (EO) using a boron doped diamond (BDD) anode was assessed for cork boiling wastewater (CBW) molecular size fractions of >100 kDa, 50–100 kDa, 20–50 kDa, 10–20 kDa and <10 kDa, obtained through sequential use of ultrafiltration (UF) membranes. The best EO results were found in the experiments performed with no addition of supporting electrolyte and at the lowest applied stirring speed, the more economical and environmentally friendly conditions. The highest EO treatment efficiency was observed for the fraction >100 kDa, which presented also the highest organic load. EO treatment led to an increase in the biodegradability of the fraction >100 kDa and to a decrease in the biodegradability of the fraction <10 kDa. Moreover, samples toxicity was not affected by the EO process, suggesting that the treated samples can be forwarded to biological post‐treatment processes. UF fractionation showed to be advantageous in combination with EO, since it enables the selective use of EO where it is more effective regarding biodegradability and current efficiency.
Vertically Grown Few‐Layer MoS2 Nanosheets on Hierarchical Carbon Nanocages for Pseudocapacitive Lithium Storage with Ultrahigh‐Rate Capability and Long‐Term Recyclability
Authors: Liu Meng , Fan Hao , Zhuo Ou , Du Xiao , Yang Longqi , Wang Peng , Yang Lijun , Wu Qiang , Wang Xizhang , Hu Zheng
Published: January 2019

Molybdenum disulfide (MoS2) is an intensively studied anode material for lithium‐ion batteries (LIBs) owing to its high theoretical capacity, but it is still confronted by severe challenges of unsatisfactory rate capability and cycle life. Herein, few‐layer MoS2 nanosheets, vertically grown on hierarchical carbon nanocages (hCNC) by a facile hydrothermal method, introduce pseudocapacitive lithium storage owing to the highly exposed MoS2 basal planes, enhanced conductivity, and facilitated electrolyte access arising from good hybridization with hCNC. Thus, the optimized MoS2/hCNC exhibits reversible capacities of 1670 mAh g−1 at 0.1 A g−1 after 50 cycles, 621 mAh g−1 at 5.0 A g−1 after 500 cycles, and 196 mAh g−1 at 50 A g−1 after 2500 cycles, which are among the best for MoS2‐based anode materials. The specific power and specific energy, which can reach 16.1 kW 
and 252.8 Wh 
after 3000 cycles, respectively, indicate great potential in high‐power and long‐life LIBs. These findings suggest a promising strategy for exploring advanced anode materials with high reversible capacity, high‐rate capability, and long‐term recyclability.
The Crystal Structure of α‐F2: Solving a 50 Year Old Puzzle Computationally
Authors: Mattsson Stefan , Paulus Beate , Redeker Frenio A. , Beckers Helmut , Riedel Sebastian , Müller Carsten
Published: January 2019

The cohesive energy of α‐fluorine, with C2/c space group symmetry, was calculated at benchmark quality by applying the method of increments. The known experimental X‐ray structure data needed to be refined, since the reported intramolecular bond length was unrealistically large. At the CCSD(T) level, including corrections for zero‐point energy, the basis set superposition error, and extrapolated to the complete basis set limit, a cohesive energy of −8.72 kJ mol−1 was calculated, which agrees well with the 0 K‐extrapolated experimental value of −8.35 kJ mol−1. Comparison of the C2/c structure with a Cmca structure, isotypic to that of chlorine, bromine, and iodine reveals that the origin of the different structure of solid fluorine, compared to the heavier halogens, is the lack of significantly stabilizing σ‐hole interactions. In addition, the wave numbers of the stretching mode in solid fluorine were calculated at coupled cluster level and compared to newly recorded Raman spectra of condensed fluorine. Both experiment and calculation indicate a slight up‐shift for the stretching mode by 2 or 5 cm−1, respectively, with respect to a free F2 molecule in the gas phase.
Heat‐Resistant Properties in the Phosphorescence of trans‐Bis[β‐(iminomethyl)aryloxy]platinum(II) Complexes: Effect of Aromaticity on d–π Conjugation Platforms
Authors: Inoue Ryo , Naito Masaya , Ehara Masahiro , Naota Takeshi
Published: January 2019

The heat‐resistant properties towards thermal emission quenching of trans‐bis[(β‐iminomethyl)aryloxy]platinum(II) complexes bearing 3‐iminomethyl‐2‐naphtholato‐ (1), 1‐iminomethyl‐2‐naphtholato‐ (2), 2‐iminomethyl‐1‐naphtholato‐ (3), and 2‐iminomethyl‐1‐phenolato (4) moieties, and a mechanistic rationale of these properties, are described in this report. Complex 1 a, with N,N′‐dipentyl groups, exhibits intense red emission in 2‐methyl‐2,3,4,5‐tetrahydrofuran (2‐MeTHF) at 298 K, whereas the analogues 2 a–4 a are less or non‐emissive under the same measurement conditions. All four complexes are highly emissive at 77 K. The heat‐resistant properties toward thermal emission quenching (Φ298 K/Φ77 K) increase in the order 1 a (0.52)>2 a (0.09)>3 a (0.02)>>4 a (0.00). We investigated the emission decay and thermal‐deactivation processes using density functional theory (DFT), time‐dependent (TD) DFT, and double‐hybrid density functional theory (DHDF) calculations of N,N′‐diethyl forms 1 b–4 b, and discuss the results with a focus on the energy levels, molecular structures, and electronic configurations in the triplet excited states. The energy differences between the triplet metal–ligand charge transfer (3MLCT) state and minimum‐energy crossing point between the lowest triplet state and singlet ground state (MECP) increase in the order 1 a>2 a, 3 a>4 a, consistent with the experimental results for the heat‐resistant properties of these complexes. The origin of the present structure dependence of the 3MLCT–MECP energy gap is ascribed to the ease or difficulty of the high‐lying dσ* orbital participating in the MECP upon thermal structural distortion. The structure dependence in energy gaps between the π* and dσ* orbitals, which is key for facilitating the thermal deactivation process, is rationally correlated with the extent of aromaticity on the coordination platforms (1 b>(2 b, 3 b)>4 b).
Identification of Active Sites and Structural Characterization of Reactive Ionic Intermediates by Cryogenic Ion Trap Vibrational Spectroscopy
Authors: Schwarz Helmut , Asmis Knut R.
Published: January 2019

Cryogenic ion trap vibrational spectroscopy paired with quantum chemistry currently represents the most generally applicable approach for the structural investigation of gaseous cluster ions that are not amenable to direct absorption spectroscopy. Here, we give an overview of the most popular variants of infrared action spectroscopy and describe the advantages of using cryogenic ion traps in combination with messenger tagging and vibrational predissociation spectroscopy. We then highlight a few recent studies that apply this technique to identify highly reactive ionic intermediates and to characterize their reactive sites. We conclude by commenting on future challenges and potential developments in the field.
Modifying LnHPDO3A Chelates for Improved T1 and CEST MRI Applications
Authors: Ferrauto Giuseppe , Delli Castelli Daniela , Leone Loredana , Botta Mauro , Aime Silvio , Baranyai Zsolt , Tei Lorenzo
Published: January 2019

The new ligand HPDO3MA [(R,R,R,R)‐10‐(2‐hydroxypropyl)‐α,α′,α′′‐trimethyl‐1,4,7,10‐tetraazacyclododecane‐1,4,7‐triacetic acid] was designed to combine and optimize the chemical properties of the macrocyclic ligands HPDO3A and DOTMA. The presence of the methyl groups on the acetic pendant arms of HPDO3A is expected to rigidify the structure of the ligand and favor an increase of the kinetic inertness of the Ln complexes. 1H NMR spectra of Eu(HPDO3MA) displayed the presence of two pairs of diastereoisomers: SAP (square antiprismatic) and TSAP (twisted square antiprismatic) isomers (56 and 44 %, respectively). In addition, 1H and 17O relaxometric NMR studies of Gd(HPDO3MA) showed approximately a 10 % increase in relaxivity and a faster water exchange rate with respect to Gd(HPDO3A). Moreover, a detailed chemical exchange saturation transfer (CEST) characterization of Yb(HPDO3MA) displayed a sensitivity about two times larger than that of Yb(HPDO3A) both in phantom and in cell labeling experiments. Finally, the kinetic inertness of Yb(HPDO3MA) was measured to be twice as high as that of Yb(HPDO3A), with a dissociation half‐life at physiological pH of about 2500 years.
A Diketopyrrolopyrrole‐Based Dimer as a Blue Pigment
Authors: Casutt Manuela , Dittmar Benedikt , Makowska Hanna , Marszalek Tomasz , Kushida Soh , Bunz Uwe H. F. , Freudenberg Jan , Jänsch Daniel , Müllen Klaus
Published: January 2019

1,4‐Diketopyrrolo[3,4‐c]pyrroles (DPPs) constitute a class of hydrogen‐bonded pigments covering a color range from yellow–orange to dark violet. We report facile dimerization of a Boc‐substituted 3,6‐dithienyl‐DPP. The formed dimer shows brilliantly blue color as a result of the expansion of the chromophore. The soluble dimer acts as latent pigment and is converted to the corresponding pigment either via thermocleavage or acidic deprotection of the Boc groups. The synthesized pigment is characterized by high migrational stability in a polymer matrix and a clear blue color.
Ce(IO3)2F2⋅H2O: The First Rare‐Earth‐Metal Iodate Fluoride with Large Second Harmonic Generation Response
Authors: Abudouwufu Tushagu , Zhang Min , Cheng Shichao , Yang Zhihua , Pan Shilie
Published: January 2019

Invited for the cover of this issue is Shilie Pan and co‐workers at Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences. The first rare‐earth iodate fluoride, Ce(IO3)2F2⋅H2O, has been synthesized, which produces a large second harmonic generation response. Read the full text of the article at 10.1002/chem.201804995.
Palladium‐Catalyzed Asymmetric Dihydroxylation of 1,3‐Dienes with Catechols
Authors: Fan Tao , Shen Hong‐Cheng , Han Zhi‐Yong , Gong Liu‐Zhu
Published: January 2019

Summary of main observation and conclusion

A palladium‐catalyzed asymmetric dihydroxylation of 1,3‐dienes with catechols is developed using chiral pyridinebis(oxazoline) ligands. Various chiral 2‐substituted 1,4‐benzodioxanes could be synthesized with moderate to high yields and enantioselectivities from readily available starting materials. The reaction is proposed to proceed through a cascade Wacker‐type hydroxypalladation/asymmetric allylation process.
Unpacking the Pathogen Box—An Open Source Tool for Fighting Neglected Tropical Disease
Authors: Veale Clinton G. L.
Published: January 2019

The Pathogen Box is a 400‐strong collection of drug‐like compounds, selected for their potential against several of the world's most important neglected tropical diseases, including trypanosomiasis, leishmaniasis, cryptosporidiosis, toxoplasmosis, filariasis, schistosomiasis, dengue virus and trichuriasis, in addition to malaria and tuberculosis. This library represents an ensemble of numerous successful drug discovery programmes from around the globe, aimed at providing a powerful resource to stimulate open source drug discovery for diseases threatening the most vulnerable communities in the world. This review seeks to provide an in‐depth analysis of the literature pertaining to the compounds in the Pathogen Box, including structure–activity relationship highlights, mechanisms of action, related compounds with reported activity against different diseases, and, where appropriate, discussion on the known and putative targets of compounds, thereby providing context and increasing the accessibility of the Pathogen Box to the drug discovery community.
Schwann cell guidance of nerve growth between synaptic sites explains changes in the pattern of muscle innervation and remodeling of synaptic sites following peripheral nerve injuries
Authors: Kang Hyuno , Tian Le , Thompson Wesley J.
Published: January 2019

Terminal Schwann cells (SCs) are nonmyelinating glia that are a prominent component of the neuromuscular junction (NMJ) where motor neurons form synapses onto muscle fibers. These cells play important roles not only in development and maintenance of the neuromuscular synapse but also restoring synaptic function after nerve damage. In response to muscle denervation, terminal SCs undergo dramatic changes in their gene expression patterns as well as in their morphology, such as extending elaborate processes into inter‐junctional space. These SC processes serve as a path to guide axon terminal sprouts from nearby innervated junctions, promoting rapid reinnervation of denervated fibers. We studied the role of terminal SCs in synapse reformation by using two different fluorescent proteins to simultaneously label motor axons and SCs; we examined these junctions repeatedly in living animals using a fluorescence microscope. Here, we show that alterations in the patterns of muscle innervation following recovery from nerve injury can be explained by SC guidance of regenerating axons. In turn, this guidance leads to remodeling of the NMJ itself.
Differential innervation within a transverse plane of spinal gray matter by sensorimotor cortices, with special reference to the somatosensory cortices
Authors: Kameda Hiroshi , Murabe Naoyuki , Odagaki Kaoru , Mizukami Hiroaki , Ozawa Keiya , Sakurai Masaki
Published: January 2019

The corticospinal (CS) neurons projecting to the cervical cord distribute not only in motor‐related cortical areas, but also in somatosensory areas, including the primary somatosensory cortex (S1). The exact functions of these widely distributed CS neurons are largely unknown, however. In this study, we injected mice with adeno‐associated virus encoding membrane‐binding fluorescent proteins to investigate the distribution of axons from CS neurons in different regions within a broad cortical area. We found that CS axons from the primary motor cortex (M1), the rostral part of S1 (S1r), and the caudal part of S1 (S1c) differentially project to specific compartments within the spinal gray matter of the seventh cervical cord segment: (a) M1 projects mainly to intermediate and ventral areas, (b) S1r to the mediodorsal area, and (c) S1c to the dorsolateral area. We also found that the projection from S1r, which corresponds to the forelimb area, largely overlaps the cutaneous afferent terminals from the forepaw (hand) in the dorsal horn, and we detected a similar relation between S1c and the trunk. Our findings suggest the existence of considerably fine somatotopic compartments within the dorsal horn that process somatosensation and descending information, which is provided mainly by S1 CS neurons and contribute to delicate control of sensory information in generation of movement.
Excited‐State Dynamics of [Ru(bpy)3]2+ Thin Films on Sensitized TiO2 and ZrO2
Authors: Leandri Valentina , Liu Peng , Sadollahkhani Azar , Safdari Majid , Kloo Lars , Gardner James M.
Published: January 2019

The excited state dynamics of Tris(2,2′‐bipyridine)ruthenium(II) hexafluorophosphate, [Ru(bpy)3(PF6)2], was investigated on the surface of bare and sensitized TiO2 and ZrO2 films. The organic dyes LEG4 and MKA253 were selected as sensitizers. A Stern–Volmer plot of LEG4‐sensitized TiO2 substrates with a spin‐coated [Ru(bpy)3(PF6)2] layer on top shows considerable quenching of the emission of the latter. Interestingly, time‐resolved emission spectroscopy reveals the presence of a fast‐decay time component (25±5 ns), which is absent when the anatase TiO2 semiconductor is replaced by ZrO2. It should be specified that the positive redox potential of the ruthenium complex prevents electron transfer from the [Ru(bpy)3(PF6)2] ground state into the oxidized sensitizer. Therefore, we speculate that the fast‐decay time component observed stems from excited‐state electron transfer from [Ru(bpy)3(PF6)2] to the oxidized sensitizer. Solid‐state dye sensitized solar cells (ssDSSCs) employing MKA253 and LEG4 dyes, with [Ru(bpy)3(PF6)2] as a hole‐transporting material (HTM), exhibit 1.2 % and 1.1 % power conversion efficiency, respectively. This result illustrates the possibility of the hypothesized excited‐state electron transfer.
Density Functional Theory Study of Aspirin Adsorption on BCN Sheets and their Hydrogen Evolution Reaction Activity: a Comparative Study with Graphene and Hexagonal Boron Nitride
Authors: Yadav Vivek K. , Mir Showkat H. , Singh Jayant K.
Published: January 2019

We explored the aspirin adsorption and their hydrogen evolution reaction (HER) activity in waste water of borocarbonitride sheets. Our results indicate that BCN sheets considered here show HER activity and exhibit superior performance regarding adsorption of aspirin in waste water in comparison with graphene and hexagonal boron nitride (h‐BN). The drug molecule (aspirin) possesses a strong affinity to BCN, with the order of binding energy on following the order BCN∼h‐BN>graphene. Upon drug adsorption, the band gap of h‐BN is found to be reduced by up to 33 %, whereas the bandgaps of graphene and BCN remain unaltered that makes BCN a potential candidate for HER in waste water.
Effects of cognitive behavioural therapy on verbal learning and memory in major depression: Results of a randomized controlled trial
Authors: Dannehl Katharina , Rief Winfried , Euteneuer Frank
Published: January 2019

Major depression (MD) is often accompanied by deficits in cognitive functioning. Cognitive behavioural therapy (CBT) has beneficial effects on MD. The aim of this study was to examine whether CBT affects verbal learning and memory in patients with MD and whether CBT that emphasizes exercise during behavioural activation has additional effects on verbal performance. Ninety‐eight patients with MD were randomly assigned to CBT emphasizing either exercise during behavioural activation (CBT‐E) or CBT emphasizing pleasurable low‐energy activities (CBT‐C). A passive waiting list control group was also involved (WL). Thirty nondepressed age‐ and sex‐matched controls were included to examine potential verbal learning and memory alterations in MD at baseline. Neuropsychological measures were assessed at baseline and after 16 weeks of CBT and waiting time, respectively. Patients with MD demonstrated worse cognitive performance than healthy controls in verbal learning, recognition, and memory at baseline. After treatment, we found no improvements concerning verbal learning and memory performance compared with WL, with the exception of recognition memory. No differences were found between CBT conditions. Psychological treatments such as CBT seem to have limited influence on memory functions. Concerning recognition memory, our results contradict, in part, previous assumptions that cognitive impairments persists despite depressive symptom reduction.
Fluorine‐Substituted Tetraphenylethene Isomers with Different Triboluminescence Properties
Authors: Tu Jin , Liu Fan , Wang Jiaqiang , Li Xiaoyu , Gong Yanbin , Fan Yunhao , Han Mengmeng , Li Qianqian , Li Zhen
Published: January 2019

Three isomers of fluorine‐substituted tetraphenylethenes (TPE) demonstrate totally different triboluminescence (TL) properties resulting from minor structural differences. Studying the photophysical properties, packing models, and the single‐crystal structure combined with density functional theory (DFT) calculations confirmed that bright TL emission can be attributed to the high emission intensity, strongintermolecular interactions and large dipole moments in the solid state, indicating that the introduction of fluorine atoms is an effective approach to obtain and modify the TL performance.
Approach to problem of minimizing network power consumption based on robust optimization
Authors: Das Bimal Chandra , Takahashi Satoshi , Oki Eiji , Muramatsu Masakazu
Published: January 2019

In this paper, a green and robust optimization model is introduced to minimize network power consumption, which allows fluctuations of traffic demands between source‐destination pairs in the network. Our model is based on the green hose model, where the traffic is bounded by just total outgoing and incoming amount at each node. In addition to the green hose model, we use the ellipsoidal uncertainty set to allow a different type of fluctuations in traffic demands. Here, the total amount of squared errors in traffic demands is bounded by a constant which controls the total admissible fluctuations over the network. Applying the conic duality, we formulate our model in the form of mixed‐integer second order cone programming (MISOCP) problem. Furthermore, we establish a relationship between our model and the green hose model with bound of link traffic (HLT) model, an developed version of the hose model known as the HLT. Numerical results demonstrate that each of the MISOCP problems can be solved to its optimality in a reasonable time by a general MISOCP solver, and that the proposed model has different tendency in performance with the green hose and green HLT models.
Analytical modeling of RLC protocol of LTE using stochastic reward nets
Authors: Gupta Shivani , Gupta Vandana
Published: January 2019

RLC (radio link control) is a layer 2 protocol of LTE used for reliable transmission of data packets in communication networks. This protocol operates in three modes, namely, transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM). In this paper, analytical models are developed to study the flow of data streams in all the three modes of the RLC protocol. Stochastic reward net (SRN) is adopted as a modeling technique as it easily captures various aspects of this protocol such as protocol data unit (PDU) transmission, assigning header with each PDU, requesting for status report, retransmission of PDU(s), management of PDU losses due to expiration of various timers (quick repeat timer, poll timer, status timer). Throughput, average delay and probability of PDU loss are evaluated as the performance measures using the SRN models. Based on these performance measures, a comparative study between the UM and AM is presented which depicts that the modes are performing their key functions decently. Analytical results are also validated via simulation.
Book Review
Authors: Pomper Markus
Published: January 2019

Up and Running: Starting and Growing a Leadership Program at a Community College
Wnt/β‐catenin signaling in the mouse embryonic cranial mesenchyme is required to sustain the emerging differentiated meningeal layers
Authors: DiNuoscio Gregg , Atit Radhika P.
Published: January 2019

Cranial neural crest cells (CNCCs) give rise to cranial mesenchyme (CM) that differentiates into the forebrain meningeal progenitors in the basolateral and apical regions of the head. This occurs in close proximity to the other CNCC‐CM‐derivatives, such as calvarial bone and dermal progenitors. We found active Wnt signaling transduction in the forebrain meningeal progenitors in basolateral and apical populations and in the non‐meningeal CM preceding meningeal differentiation. Here, we dissect the source of Wnt ligand secretion and requirement of Wnt/β‐catenin signaling for the lineage selection and early differentiation of the forebrain meninges. We find persistent canonical Wnt/β‐catenin signal transduction in the meningeal progenitors in the absence of Wnt ligand secretion in the CM or surface ectoderm, suggesting additional sources of Wnts. Conditional mutants for Wntless and β‐catenin in the CM showed that Wnt ligand secretion and Wnt/β‐catenin signaling were dispensable for specification and proliferation of early meningeal progenitors. In the absence of β‐catenin in the CM, we found diminished laminin matrix and meningeal hypoplasia, indicating a structural and trophic role of mesenchymal β‐catenin signaling. This study shows that β‐catenin signaling is required in the CM for maintenance and organization of the differentiated meningeal layers in the basolateral and apical populations of embryonic meninges.
The effect of landscape structure on dispersal distances of the Eurasian red squirrel
Authors: Hämäläinen Suvi , Fey Karen , Selonen Vesa
Published: January 2019

Landscape structure can affect dispersal and gene flow in a species. In urban areas, buildings, roads, and small habitat patches make the landscape highly fragmented and can inhibit movement and affect dispersal behavior. Similarly, in rural forested areas, large open areas, such as fields, may act as barriers to movement. We studied how landscape structure affects natal dispersal distances of Eurasian red squirrels (Sciurus vulgaris) in an urban area and a rural area in Finland, by monitoring juvenile red squirrels with radio telemetry. We observed extremely long dispersal distances—up to 16 km—in the rural study area, but shorter distances—on average only half a kilometer—in the urban study area. The landscape structure affected the eventual dispersal paths; in the rural landscape, dispersers favored spruce dominated areas and avoided fields along their dispersal route, although they occasionally even crossed wide fields. In the urban landscape, squirrels preferred areas with deciduous or coniferous trees. The movement steps made by dispersers were longer in the more hostile landscape compared to forested areas. Despite these effects on movement path, the landscape structure only had a minor effect on straight line dispersal distances moved from the natal nest. In other words, individuals moved longer distances and were likely to circumvent barriers in their path, but this did not affect how far they settled from their natal home. This result indicates that, although landscape structure has obvious effects on movement, it still may have only a small effect on other aspects of the population, for example, gene flow.
Ecological relevance of anabranch confluences: Hydrological and morphological effects
Authors: Blettler Martín C. M. , Amsler Mario L. , Espinola Luis A. , Rabuffetti Ana Pía , De Drago Ines Ezcurra , Drago Edmundo E.
Published: January 2019

The aim of the current study was to determine the ecological role of anabranch confluences at diverse hydrological regimes, taking into consideration the floodplain secondary channels of a large river as a case of study. In conducting this study, we used unpublished data from sampling campaigns performed in the past. Triplicate benthic sediment samples were taken at each station using a bottom grab and according to sampling protocols equal to the current ones. Benthic taxa were identified at the species and genus levels. According to our results, a protracted effect by the El Niño–Southern Oscillation (ENSO) phenomenon on benthic fauna structure was evident. This effect was observed not only in the confluences but also all along the rivers, reflecting its ecological effect at least 1.5 years after its occurrence. Thus, the ENSO effect on benthic organisms should not be treated like a “physical action–reaction” but rather as an ecological relationship with lag periods (“ecological inertia”) after its occurrence. On the other hand, one of the studied confluences was categorized as a “hydro‐geomorphic patch” along the river channel, resulting from shifts in hydraulic and sedimentological conditions, which are explained by local morphological features. This hydro‐geomorphic patch created a critical site of abrupt changes in ecological patterns, enhancing the biodiversity of the river system. However, this hydro‐geomorphic patch was not detected in another anabranch confluence, where the benthic assemblage was comparable with that recorded in straight sections. Accordingly, we concluded that the mere presence of an anabranch confluence is not a sufficient reason to assume enhancing local habitat heterogeneity or biodiversity.
Cardiac arrest in Wilson's disease after curative liver transplantation: a life‐threatening complication of myocardial copper excess?
Authors: Bobbio Emanuele , Forsgard Niklas , Oldfors Anders , Szamlewski Piotr , Bollano Entela , Andersson Bert , Lingbrant Marie , Bergh Niklas , Karason Kristjan , Polte Christian L.
Published: January 2019

We report the case of a 38‐year‐old man who presented with cardiac arrest 1 year after curative liver transplantation for Wilson's disease. Clinical work‐up proofed myocardial copper and iron accumulation using mass spectrometry, which led most likely to myocardial fibrosis as visualized by cardiovascular magnetic resonance (unprecedented delayed enhancement pattern) and endomyocardial biopsy. Consequently, cardiac arrest due to ventricular fibrillation and subsequent episodes of sustained ventricular tachycardia were considered as primary cardiac manifestation of Wilson's disease. This can, as illustrated by our case, occur even late after curative liver transplantation, which is an important fact that treating physicians should be aware of during clinical follow‐up of these patients.
Unified Synthesis of Densely Functionalized Amino Acid Building Blocks for the Preparation of Caprazamycin Nucleoside Antibiotics
Authors: Linder Ruth , Ducho Christian
Published: January 2019

Naturally occurring caprazamycin nucleoside antibiotics are promising lead structures for the development of novel antimicrobial agents. However, efficient synthetic access to the structurally complex caprazamycin scaffold is not trivial. The stereocontrolled construction of the seven‐membered diazepanone core moiety is particularly challenging. So far, two main strategies to build up the diazepanone system (by reductive amination or Mitsunobu reaction) have been established, but they require different non‐proteinogenic amino acid building blocks to be connected with the nucleoside moiety. Previously, these amino acid structures were obtained from different starting materials with no overlap of the according synthetic routes. In this work, we describe an efficient unified synthetic access to densely functionalized amino acid building blocks for both approaches towards the diazepanone core. This will enable the preparation of caprazamycin analogues with high modularity and variability.
Rewarded placebo analgesia: A new mechanism of placebo effects based on operant conditioning
Authors: Adamczyk Wacław M. , Wiercioch‐Kuzianik Karolina , Bajcar Elżbieta A. , Bąbel Przemysław
Published: January 2019

Background

Placebo analgesia is explained by two learning processes: classical conditioning and observational learning. A third learning process, operant conditioning, has not previously been investigated as a mechanism of placebo effects. We aimed to induce placebo analgesia by operant conditioning.

Methods

Three groups of participants received electrocutaneous pain stimuli of the same intensity, preceded by either an orange or blue stimulus. In the conditioning phase of the study, participants from the experimental group were rewarded for low pain responses following one of the colour stimuli (placebo) and for high pain responses following the other colour stimuli (non‐placebo). Moreover, they were punished when their pain responses were high following placebo stimuli and low following non‐placebo stimuli. To investigate the role of contingency, that is dependent relation between rewards/punishers and pain responses, the random‐control group received rewards and punishers in a non‐contingent manner. The colour‐control group did not receive any rewards or punishers to control for nonassociative learning. Pain intensity ratings were used as an outcome measure, and verbal feedback on pain ratings was used as rewards/punishers.

Results

When rewarding and punishment were stopped, only participants from the experimental group experienced less pain following the placebo than following the non‐placebo stimuli; that is, placebo analgesia was found in this group. This effect was not extinguished during the study.

Conclusions

Placebo analgesia can be induced by operant conditioning, which should be considered a third mechanism for producing placebo effects. Moreover, the contingency between pain responses and rewards/punishers is crucial to induce placebo analgesia through operant conditioning.

Significance

According to the current placebo literature, placebo analgesia can be explained by two learning processes: classical conditioning and observational learning. A third learning process, operant conditioning, has not previously been investigated as a mechanism of placebo effects. Our study reveals that patients can learn placebo analgesia as a result of operant conditioning, suggesting that randomized controlled trials could be improved by controlling the reinforcement that might occur spontaneously when patients interact with, for example, medical personnel.
Bioavailability of mercury in contaminated soils assessed by the diffusive gradient in thin film technique in relation to uptake by Miscanthus × giganteus
Authors: Ridošková Andrea , Pelfrêne Aurélie , Douay Francis , Pelcová Pavlína , Smolíková Vendula , Adam Vojtěch
Published: January 2019

We assessed the relationship between the diffusive gradient in thin film (DGT) technique using the new ion-exchange resin Ambersep GT74 and the uptake of mercury (Hg) by a model plant cultivated on metal-contaminated agricultural soils under greenhouse conditions. Based on the total Hg content, 0.37 to 1.17% of the Hg passed to the soil porewater from the solid phase, and 2.18 to 9.18% of the Hg is DGT-available. These results were confirmed by calculating the R value (the ratio of the concentrations of bioavailable Hg measured by DGT and soil solution), which illustrated the strong bonding of Hg to the solid phase of soil and its extremely low mobility. Only inorganic Hg2+ species were found in the metal-contaminated agricultural soils, as determined by a high-performance liquid chromatography–cold vapor atomic fluorescence spectrometry speciation analysis. The Hg was distributed in Miscanthus × giganteus organs in the following order for all sampling sites: roots (55–82%) >> leaves (8–27%) > stems (7–16%) > rhizomes (4–7%). Environ Toxicol Chem 2019;38:321–328. © 2018 SETAC
Gonadosomatic index as a confounding variable in fish-based screening assays for the detection of anti-estrogens and nonaromatizable androgens
Authors: Roush Kyle S. , Jeffries Marlo K. Sellin
Published: January 2019

The presence of reproductive endocrine-disrupting compounds (REDCs) in the environment poses a potential threat to fish and wildlife, because exposures are capable of altering sexual development, reproductive success, and behavior. Fish-based screening assays are often utilized to screen for the presence of REDCs in surface waters and to assess single chemicals for potential endocrine-disrupting activity. In an effort to improve such screening assays, the goal of the present study was to determine whether the gonadosomatic index (GSI) of female fathead minnows (Pimephales promelas), as assessed via external characteristics, influences their response to REDC exposure. Specifically, we sought to determine whether low-GSI females differed from high-GSI females in their responses to the model anti-estrogen fadrozole and the model androgen 17β-trenbolone, and whether there was a preferable classification in the context of REDC screening. Low-GSI females were more sensitive to fadrozole at the lower concentration of fadrozole (5 µg/L) and to the higher concentration of trenbolone (50 ng/L), whereas high-GSI females were more sensitive at the lower concentration of trenbolone (5 ng/L). The differential response of low- and high-GSI females to REDCs indicates that GSI influences exposure outcome, and should subsequently be taken into consideration in the implementation of screening assays, as failure to utilize fish of the appropriate reproductive status may skew the test results. Environ Toxicol Chem 2019;38:603–615. © 2019 SETAC
Experimental and numerical analysis of the influence of cable tray arrangements on the resulting mass loss rate and fire spreading
Authors: Siemon Matthias , Riese Olaf , Forell Burkhard , Krönung Dominic , Klein‐Heßling Walter
Published: January 2019

In the context of industrial buildings and power plants, electrical installations and cable trays represent a main fuel load and a potential initial fire source due to possible short circuits or comparable malfunction. Furthermore, a fire can spread from one tray to additional trays mounted above and/or horizontally on one tray. Because of the high significance of cable fires, several research projects have been carried out, investigating the fire behaviour of cables from small‐scale tests, eg, the cone calorimeter, up to large‐scale tests, analysing complete cable tray constructions. The goal of the work presented in this paper is the extension of the knowledge regarding the influence of geometrical parameters like the packing density and tray distance on the burning behaviour and fire spread of cable tray installations. The results are considered, together with test results from the literature, to quantify the main physical parameters describing the burning behaviour. In a next step, the general applicability of these parameters as input data for the parametrization of the source term of numerical simulations is shown. The test results show that the burning behaviour and the fire spreading highly depend on the cable arrangement of the cables on the cable tray, in combination with other boundary conditions. By applying the results as input for a fire simulation, the mass loss rate is considered appropriately.
Die wahren Abenteuer liegen woanders
Authors: Griem Julika
Published: January 2019

Wissenschaftskommunikation ist in aller Munde. Doch Storytelling und Eventisierung allein werden der Realität und Komplexität der Wissenschaften nicht gerecht. Gefragt ist eine Vermittlung, die aus Konflikten, Widersprüchen und Perspektivenvielfalt Funken schlagen lässt. Dazu braucht es Handwerk und Haltung zugleich.
Früchte der Tiefsee
Authors: Erbacher Jochen
Published: January 2019

International Ocean Discovery Program: Der weltweit größte geowissenschaftliche Forschungsverbund feiert seinen 50. Geburtstag. Wissenschaftlich und finanziell unter maßgeblicher deutscher Beteiligung, liefern die IODP‐Expeditionen und ihre Bohrkerne grundlegende Einsichten in Erdaufbau und Klimageschichte.
Liberal oder restriktiv?
Authors: Simon Stephan , Helbling Marc
Published: January 2019

In den hitzigen Einwanderungsdebatten in Politik, Medien und Öffentlichkeit sind Zahlen und Fakten mehr denn je gefragt. Sozialwissenschaftler haben die Migrationspolitik in 33 OECD‐Staaten zwischen 1980 und 2010 im Vergleich untersucht. Die so entstandene Datenbank soll mit verschiedensten Kennzahlen auch die künftige Forschung erleichtern.
The Spanish Mediterranean Fishing Guilds (Cofradías): An Example of Collaborative Management with a Key Role in Sustainable Fisheries
Authors: Herrera-Racionero Paloma , Lizcano Emmánuel , Miret-Pastor Lluis , Mascarell Yesmina
Published: January 2019

The management of Spanish coastal fisheries is based on a mixed model where the centralised action of the government is combined with the self-organisation of fishers in cofradías (guilds). These institutions have economic and political functions, intermediating between the State and the fishing sector and mediating in the conflicts that may occur. They also have welfare and mutualist tasks. This original and traditional co-management model is part of the social capital of traditional Spanish fishing. The aim of this article is to explore the possibilities of these Spanish fishers’ organisations in order to improve the legitimacy of the fishery system and the sustainability of fisheries. Our hypothesis is that updating and adapting some aspects of the cofradías model could produce efficient forms of collaborative management and lead to improvements in the sustainability of fisheries. To validate this hypothesis the study analysed 69 face-to-face interviews in 21 Spanish–Mediterranean guilds. The analysis focused on three core aspects: the control of fishing resources; the integration of fishing knowledge in the management system; and, finally, the guilds contribution to the legitimacy of the system in the eyes of the fishers.
A simple and accurate method to determine genomewide significance for association tests in sequencing studies
Authors: Lin Dan‐Yu
Published: January 2019

Whole‐exome sequencing (WES) and whole‐genome sequencing (WGS) studies are underway to investigate the impact of genetic variants on complex diseases and traits. It is customary to perform single‐variant association tests for common variants and region‐based association tests for rare variants. The latter may target variants with similar or opposite effects, interrogate variants with different frequencies or different functional annotations, and examine a variety of regions. The large number of tests that are performed necessitates adjustment for multiple testing. The conventional Bonferroni correction is overly conservative as the test statistics are correlated. To address this challenge, we propose a simple and accurate method based on parametric bootstrap to assess genomewide significance. We show that the correlations of the test statistics are determined primarily by the genotypes, such that the same significance threshold can be used in different studies that share a common sequencing platform. We demonstrate the usefulness of the proposed method with WES data from the National Heart, Lung, and Blood Institute Exome Sequencing Project and WGS data from the 1000 Genomes Project. We recommend the p value of as the genomewide significance threshold for testing all common and low‐frequency variants (MAFs 0.1%) in the human genome.
A simple approximation to the bias of gene–environment interactions in case–control studies with silent disease
Authors: Lobach Iryna , Sampson Joshua , Lobach Siarhei , Alekseyenko Alexander , Piryatinska Alexandra , He Tao , Zhang Li
Published: January 2019

One of the most important research areas in case–control Genome‐Wide Association Studies is to determine how the effect of a genotype varies across the environment or to measure the gene–environment interaction (G × E). We consider the scenario when some of the “healthy” controls actually have the disease and when the frequency of these latent cases varies by the environmental variable of interest. In this scenario, performing logistic regression with the clinically diagnosed disease status as an outcome variable and will result in biased estimates of G × E interaction. Here, we derive a general theoretical approximation to the bias in the estimates of the G × E interaction and show, through extensive simulation, that this approximation is accurate in finite samples. Moreover, we apply this approximation to evaluate the bias in the effect estimates of the genetic variants related to mitochondrial proteins a large‐scale prostate cancer study.
Extracellular ATP and glutamate drive pyruvate production and energy demand to regulate mitochondrial respiration in astrocytes
Authors: Juaristi Inés , Llorente‐Folch Irene , Satrústegui Jorgina , del Arco Araceli
Published: January 2019

Astrocytes respond to energetic demands by upregulating glycolysis, lactate production, and respiration. This study addresses the role of respiration and calcium regulation of respiration as part of the astrocyte response to the workloads caused by extracellular ATP and glutamate. Extracellular ATP (100 μM to 1 mM) causes a Ca2+‐dependent workload and fall of the cytosolic ATP/ADP ratio which acutely increases astrocytes respiration. Part of this increase is related to a Ca2+‐dependent upregulation of cytosolic pyruvate production. Conversely, glutamate (200 μM) causes a Na+, but not Ca2+, dependent workload even though glutamate‐induced Ca2+ signals readily reach mitochondria. The glutamate workload triggers a rapid fall in the cytosolic ATP/ADP ratio and stimulation of respiration. These effects are mimicked by D‐aspartate a nonmetabolized agonist of the glutamate transporter, but not by a metabotropic glutamate receptor agonist, indicating a major role of Na+‐dependent workload in stimulated respiration. Glutamate‐induced increase in respiration is linked to a rapid increase in glycolytic pyruvate production, suggesting that both glutamate and extracellular ATP cause an increase in astrocyte respiration fueled by workload‐induced increase in pyruvate production. However, glutamate‐induced pyruvate production is partly resistant to glycolysis blockers (iodoacetate), indicating that oxidative consumption of glutamate also contributes to stimulated respiration. As stimulation of respiration by ATP and glutamate are similar and pyruvate production smaller in the first case, the results suggest that the response to extracellular ATP is a Ca2+‐dependent upregulation of respiration added to glycolysis upregulation. The global contribution of astrocyte respiratory responses to brain oxygen consumption is an open question.
Effect of repetitive elbow holding tasks with low‐level muscular exertion on perceived muscle discomfort
Authors: Chihara Takanori , Nozawa Ayana , Seo Akihiko , Sakamoto Jiro
Published: January 2019

This study aimed to investigate the effect of task repetition on perceived muscle discomfort (PMD). The experimental trial consisted of fatigue and recovery periods. In the fatigue period, an elbow‐holding task was performed with an external load of 10%, 20%, and 30% of the premeasured maximum voluntary contraction (MVC) for 7.0, 4.5, and 3.0 min, respectively. In the recovery period, the participants released the load and rested until they felt no PMD. The trial was repeated six times sequentially (Trials 1–6). PMD at the end of the fatigue period increased with task repetition at all %MVCs. The interclass correlation coefficients between Trial 1 and the other trials were lower than those for the combinations of Trials 2–6, irrespective of %MVC. In the recovery period, the absolute sensitivity of PMD in the range of 0–10 (or the speed of recovery) of Trial 1 was faster than that of Trials 2–6. The findings of this study could lead to the development of work regimes that limit the risk of PMD in workers. Possible changes include allowing for a longer recovery time if the task requires a relatively large flexion angle, such as those performed in narrow spaces.