bluuebunny/crossref_metadata_2025_split huggingface dataset:
CuZn Catalysts Superior to Adkins Catalysts for Dimethyl Adipate Hydrogenolysis
Authors: Pospelova Violetta , Aubrecht Jaroslav , Kikhtyanin Oleg , Pacultová Kateřina , Kubička David 
Published: March 2019

AbstractIndustrial hydrogenolysis of esters to alcohols relies on the use of Adkins catalysts whose production and disposal is an environmental burden. This work is focused on CuZn catalysts that represent an ecological alternative to Adkins catalysts. Four CuZn catalysts with Cu/Zn atomic ratio ranging from 0.5 to 2.0 and single phase CuO and ZnO catalysts were prepared by co‐precipitation and their hydrogenolysis activity was compared with a commercial Adkins catalyst. Dimethyl adipate was used to test the catalyst performance in a flow reactor at temperatures ranging from 175 to 205 °C and hydrogen pressure of 16 MPa. The increase in ZnO content was directly responsible for the reduction in copper crystallite size and increase in the catalyst specific surface area. The CuZn catalysts exhibited higher conversion than the Adkins catalyst despite their specific surface area declined during the experiments more significantly than that of the Adkins catalyst. Nonetheless, the TOF of CuZn catalysts exceeded that of the commercial Adkins catalyst.
Alternatives for the Purification of the Blend Butanol/Ethanol from an Acetone/Butanol/Ethanol Fermentation Effluent
Authors: Contreras-Vargas Carlos Alfredo , Gómez-Castro Fernando Israel , Sánchez-Ramírez Eduardo , Segovia-Hernández Juan Gabriel , Morales-Rodríguez Ricardo , Gamiño-Arroyo Zeferino 
Published: March 2019

AbstractBiobutanol is a biofuel with potential to substitute gasoline. It can be generated through fermentation of lignocellulosic material, by which acetone, butanol, and ethanol (ABE) are obtained and subsequently separated. Nevertheless, the blend ethanol/butanol itself is a fuel, so its separation could be not even necessary. An alternative is proposed to simplify the purification step of the ABE mixture, avoiding the separation of the ethanol/butanol blend. Intensification alternatives are suggested for the resulting structure. The proposed schemes are optimized through a stochastic approach, minimizing the total annual cost and the eco‐indicator 99. The individual risk index is computed for selected designs. The suggested designs reduce the individual risk index by around 30–66 %.
Reversible Effects of Periodic Polarization on Anodic Electroactive Biofilms
Authors: Zhang Xu , Rabaey Korneel , Prévoteau Antonin 
Published: March 2019

AbstractAnodic electroactive biofilms (EABs) are commonly grown under continuous polarization of the underlying electrode. Their growth under appropriate periodic polarization was recently reported to considerably enhance their electrochemical properties (catalytic current and charge carriers concentration). This improvement was only investigated on relatively short term (ten days), and its resilience once the periodic polarizations are switched back to continuous (or vice versa) has not yet been assessed. Here, we first cultivated 16 Geobacter‐dominated EABs on glassy carbon electrodes under either continuous or periodic polarization for several days. The polarization mode was then switched from continuous to periodic and vice versa. The improvement induced by the initial periodic polarization was lost over only two days of continuous polarization. Conversely, it took about ten days of periodic polarization to fully improve the electroactivity of the EABs initially grown under continuous polarization. The periodic polarization favored biofilm detachments, which were followed by a full recovery of current within three days. The performance of EABs under periodic polarization was less negatively impacted under substrate‐limiting conditions, likely because of substrate replenishment during open circuit periods.
Electrochemical and Scalable Dehydrogenative C(sp3)−H Amination via Remote Hydrogen Atom Transfer in Batch and Continuous Flow
Authors: Nikolaienko Pavlo , Jentsch Marc , Kale Ajit P. , Cai Yunfei , Rueping Magnus 
Published: March 2019

AbstractA hydrogen atom transfer‐directed electrochemical intramolecular C−H amination has been developed in which the N‐radical species are generated at the anode, and the base required for the reaction is generated at the cathode. A broad range of valuable pyrrolidines were prepared in good yields and with high chemoselectivity. The reaction was easily scaled up in both batch and continuous flow systems.
Dispirocycles: Platforms for the Construction of High‐Performance Host Materials for Phosphorescent Organic Light‐Emitting Diodes
Authors: Liu Xiang‐Yang , Zhang Yi‐Jie , Fei Xiyu , Fung Man‐Keung , Fan Jian 
Published: March 2019

AbstractSpirocyclic compounds such as 9,9′‐spirobifluorene (SBF) are becoming more and more attractive for use as host materials in organic optoelectronic devices. Herein, two dispirocycles, namely, dispiro[fluorene‐9,9′‐anthracene‐10′,9′′‐fluorene] and 10,10′′‐diphenyl‐10H,10′′H‐dispiro[acridine‐9,9′‐anthracene‐10′,9′′‐acridine], were used for the construction of host materials 1–4. The attached triphenylamino group determines the thermal, photophysical, electrochemical, and charge‐transport properties, and therefore they have different electroluminescent performances. The device based on dispiro[fluorene‐9,9′‐anthracene‐10′,9′′‐fluorene] (2) and 10,10′′‐diphenyl‐10H,10′′H‐dispiro[acridine‐9,9′‐anthracene‐10′,9′′‐acridine] (3) molecular platforms exhibited external quantum efficiencies of greater than 21 % with a very high power efficiency (≈100 lm W−1). These results demonstrate the potential of extending the application of dispirocyclic molecular platforms with inherent rigidity for developing highly efficient host materials for organic light‐emitting diodes.
Dynamic Resolution of Piezosensitivity in Single Crystals of π‐Conjugated Molecules
Authors: Bhattacharyya Sohini , Sobczak Szymon , Półrolniczak Aleksandra , Roy Syamantak , Samanta Debabrata , Katrusiak Andrzej , Maji Tapas Kumar 
Published: March 2019

AbstractTargeted synthesis of piezoresponsive small molecules and in‐depth understanding of their mechanism is of utmost importance for the development of smart devices. This work reports the synthesis, structure and piezosensitivity of a bola‐amphiphile 1,4‐bis(pentyloxy)‐2,5‐bis(2‐pyridineethynyl)‐benzene (C5‐PPB). Depending on the rate of compression, two different phases in C5‐PPB can be generated. The ambient‐pressure α‐phase is stable up to 0.8 GPa, beyond which it undergoes an isostructural transformation to β‐phase, accompanied by a clearly visible elongation of the crystal. This α‐to‐β phase transition requires the sample to be compressed slowly. When quickly compressed, phase α persists to about 1.5 GPa, beyond which its amorphization starts, accompanied by the appearance of irregular grooves on the largest faces. Mechanical pressure also affects the optical property of C5‐PPB, which shows reversible mechanochromism with a green to cyan transformation in the emission, associated with a 15 nm shift in the maxima. The conductivity of C5‐PPB as a direct outcome of its crystal packing has also been studied.
Mechano‐ and Photoresponsive Behavior of a Bis(cyanostyryl)benzene Fluorophore
Authors: Kaneko Ryohei , Sagara Yoshimitsu , Katao Shouhei , Tamaoki Nobuyuki , Weder Christoph , Nakano Hideyuki 
Published: March 2019

AbstractThe mechanoresponsive behavior and photochemical response of a new bis(cyanostyryl)benzene fluorophore (CSB‐5) were investigated. Green fluorescence with λem,max of 507 nm was found for CSB‐5 in chloroform solution, mirroring the behavior of a previously reported similar dye (CSB‐6). Alternatively, crystalline samples of CSB‐5 exhibited orange fluorescence with λem,max of 620 nm, attributable to excimer emission. Although the emission color change was not clearly noticeable by naked eye, CSB‐5 exhibited mechanochromic luminescence, due to transformation into the amorphous state upon grinding the crystalline powder. Interestingly, rubbed films of CSB‐5 prepared on glass substrates exhibited a pronounced emission color change from orange to green when exposed to UV light. This response is the result of a photochemical reaction that occurs in the amorphous state and which causes a decrease of the excimer emission sites so that the emission color changes from excimer to monomer. The crystalline material did not display such a photoinduced emission color change and the difference in photochemical reactivity between crystalline and amorphous states was exploited to pattern the emission color of rubbed films.
Pt‐Like Oxygen Reduction Activity Induced by Cost‐Effective MnFeO2/N‐Carbon
Authors: Zhou Qixing , Su Zhangbin , Tang Yidan , Ai Li , Fu Gengtao , Wu Zexing , Sun Dongmei , Tang Yawen 
Published: March 2019

AbstractThe development of effective and affordable electrocatalysts for the oxygen reduction reaction (ORR) is critical for the renewable‐energy technologies. Here, we present a new manganese iron oxide (MnFeO2) as a cost‐effective material for the ORR with Pt‐like electrochemical properties. Pyrolysis of hybrid agar hydrogel on NaCl nanocrystals furnishes a unique structure in which the active MnFeO2 particles are uniformly immobilized in the nitrogen‐doped porous carbon aerogels (MnFeO2/NPC). Nitrogen‐doped carbon is introduced to construct porous mass‐transfer channels and reduce self‐aggregation of the MnFeO2 particles. It is found that the formation of the MnFeO2 phase greatly depends on the pyrolysis temperature. Benefiting from the synergy of MnFeO2 and NPC, the MnFeO2/NPC can actually be as good as the Pt/C catalyst for the ORR, with an onset‐potential of 0.98 V and a half‐wave potential of 0.86 V, combined with demonstrating a superior stability and tolerance to methanol.
Electronic Push–Pull Modulation by Peripheral Substituents in Pentaaryl Boroles
Authors: Heitkemper Tobias , Sindlinger Christian P. 
Published: March 2019

AbstractEstablishing access to a bulky tetraaryl dilithiobutadiene (Ph*C)4Li2 (Ph*=3,5‐tBu2(C6H3)) allowed for the synthesis of five‐membered heterocycles with incorporated main‐group elements. Along with an amino borole, a set of substituted pentaaryl boroles (Ph*C)4BAr has been synthesized. The examination of their absorption spectra and computational studies by means of DFT granted insight into the influence of peripheral substituents on the electronic features of the parent pentaphenyl borole (PhC)4BPh. Introduction of the more electron‐rich Ph* residue at the carbon atoms increases the HOMO energy, redshifting the visible π/π*‐absorption bands compared with the parent pentaphenyl borole. The influence on the frontier orbitals of three different boron‐bound aryls with electronically modulating substituents in the remote 3,5‐positions Ar=3,5‐R2‐C6H3 (R=Me, H, CF3) was studied. The substituents were found to increase (+I effect, Me) or decrease (−I effect, CF3) the LUMO energy, thus directly affecting the visible absorption spectra. This represents the first study on HOMO–LUMO‐gap adjustments by a combined push–pull approach of a substituted pentaphenylborole.
Stoichiometric and Catalytic Aryl−Cl Activation and Borylation using NHC‐stabilized Nickel(0) Complexes
Authors: Kuehn Laura , Jammal Dominik G. , Lubitz Katharina , Marder Todd B. , Radius Udo 
Published: March 2019

AbstractNHC‐nickel (NHC=N‐heterocyclic carbene) complexes are efficient catalysts for the C−Cl bond borylation of aryl chlorides using NaOAc as a base and B2pin2 (pin=pinacolato) as the boron source. The catalysts [Ni2(ICy)4(μ‐(η2:η2)‐COD)] (1, ICy=1,3‐dicyclohexylimidazolin‐2‐ylidene; COD=1,5‐cyclooctadiene), [Ni(ICy)2(η2‐C2H4)] (2), and [Ni(ICy)2(η2‐COE)] (3, COE=cyclooctene) compare well with other nickel catalysts reported previously for aryl‐chloride borylation with the advantage that no further ligands had to be added to the reaction. Borylation also proceeded with B2neop2 (neop=neopentylglycolato) as the boron source. Stoichiometric oxidative addition of different aryl chlorides to complex 1 was highly selective affording trans‐[Ni(ICy)2(Cl)(Ar)] (Ar=4‐(F3C)C6H4, 11; 4‐(MeO)C6H4, 12; C6H5, 13; 3,5‐F2C6H3, 14).
Proportional loss of parvalbumin‐immunoreactive synaptic boutons and granule cells from the hippocampus of sea lions with temporal lobe epilepsy
Authors: Cameron Starr , Lopez Ariana , Glabman Raisa , Abrams Emily , Johnson Shawn , Field Cara , Gulland Frances M. D. , Buckmaster Paul S. 
Published: March 2019

AbstractOne in 26 people develop epilepsy and in these temporal lobe epilepsy (TLE) is common. Many patients display a pattern of neuron loss called hippocampal sclerosis. Seizures usually start in the hippocampus but underlying mechanisms remain unclear. One possibility is insufficient inhibition of dentate granule cells. Normally parvalbumin‐immunoreactive (PV) interneurons strongly inhibit granule cells. Humans with TLE display loss of PV interneurons in the dentate gyrus but questions persist. To address this, we evaluated PV interneuron and bouton numbers in California sea lions (Zalophus californianus) that naturally develop TLE after exposure to domoic acid, a neurotoxin that enters the marine food chain during harmful algal blooms. Sclerotic hippocampi were identified by the loss of Nissl‐stained hilar neurons. Stereological methods were used to estimate the number of granule cells and PV interneurons per dentate gyrus. Sclerotic hippocampi contained fewer granule cells, fewer PV interneurons, and fewer PV synaptic boutons, and the ratio of granule cells to PV interneurons was higher than in controls. To test whether fewer boutons was attributable to loss versus reduced immunoreactivity, expression of synaptotagmin‐2 (syt2) was evaluated. Syt2 is also expressed in boutons of PV interneurons. Sclerotic hippocampi displayed proportional losses of syt2‐immunoreactive boutons, PV boutons, and granule cells. There was no significant difference in the average numbers of PV‐ or syt2‐positive boutons per granule cell between control and sclerotic hippocampi. These findings do not address functionality of surviving synapses but suggest reduced granule cell inhibition in TLE is not attributable to anatomical loss of PV boutons.
High‐Spin Mononuclear Iron(III) Complexes with Pentadentate Schiff Base Ligands: Structural Analysis and Magnetic Properties
Authors: Pogány Lukáš , Moncol Ján , Pavlik Ján , Mazúr Milan , Šalitroš Ivan 
Published: March 2019

AbstractVarious substituted 2‐hydroxybenzophenones were combined with aliphatic linear triamines to form pentadentate Schiff base ligands. Twelve new iron(III) complexes with the general formula [Fe(Ln)X].mCH3CN (n=1–10; X=N3−, NCS− or NCSe−; m=0–2) have been synthesized, and spectrally as well as structurally characterized. The structural analysis revealed a notable dependence of coordination polyhedra deformation as well as the spatial configuration of donor atoms on the length and symmetry of the Schiff base ligands. The magnetic properties of the compounds were investigated and the permanent high‐spin state (S=5/2) for all reported compounds was established, and allowed calculation of zero‐field‐splitting parameters as well as coupling constants, which were further confirmed with DFT calculations. The solid‐state EPR spectra were recorded at 293 K and 98 K, and in accordance with the magnetic measurements, showed a high‐spin state in the measured temperature range.
Predicting Cell Populations in Single Cell Mass Cytometry Data
Authors: Abdelaal Tamim , van Unen Vincent , Höllt Thomas , Koning Frits , Reinders Marcel J.T. , Mahfouz Ahmed 
Published: March 2019

AbstractMass cytometry by time‐of‐flight (CyTOF) is a valuable technology for high‐dimensional analysis at the single cell level. Identification of different cell populations is an important task during the data analysis. Many clustering tools can perform this task, which is essential to identify “new” cell populations in explorative experiments. However, relying on clustering is laborious since it often involves manual annotation, which significantly limits the reproducibility of identifying cell‐populations across different samples. The latter is particularly important in studies comparing different conditions, for example in cohort studies. Learning cell populations from an annotated set of cells solves these problems. However, currently available methods for automatic cell population identification are either complex, dependent on prior biological knowledge about the populations during the learning process, or can only identify canonical cell populations. We propose to use a linear discriminant analysis (LDA) classifier to automatically identify cell populations in CyTOF data. LDA outperforms two state‐of‐the‐art algorithms on four benchmark datasets. Compared to more complex classifiers, LDA has substantial advantages with respect to the interpretable performance, reproducibility, and scalability to larger datasets with deeper annotations. We apply LDA to a dataset of ~3.5 million cells representing 57 cell populations in the Human Mucosal Immune System. LDA has high performance on abundant cell populations as well as the majority of rare cell populations, and provides accurate estimates of cell population frequencies. Further incorporating a rejection option, based on the estimated posterior probabilities, allows LDA to identify previously unknown (new) cell populations that were not encountered during training. Altogether, reproducible prediction of cell population compositions using LDA opens up possibilities to analyze large cohort studies based on CyTOF data. © 2019 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry.
Peripubertal stress of male, but not female rats increases morphine‐induced conditioned place preference and locomotion in adulthood
Authors: Wang Dong‐Mei , Zhang Jian‐Jun , Huang Yan‐Bei , Zhao Yin‐Zhu , Sui Nan 
Published: March 2019

AbstractAnimal studies demonstrate that peripubertal social stress markedly increases the risk for subsequent substance use in adulthood. However, whether non‐social stress has a similar long‐term impact is not clear, and whether male and female animals show different sensitivity to peripubertal non‐social stress has not been examined. In the present study, we addressed these issues by introducing two non‐social stressors (elevated platform and predator odor 2,5‐Dihydro‐2,4,5‐trimethylthiazoline) to male and female Wistar rats during adolescence (postnatal days 28–30, 34, 36, 40, and 42), then tested reward‐related behaviors during adulthood, including morphine‐induced conditioned place preference (CPP, 1 mg/kg morphine or 5 mg/kg morphine) and hyperlocomotor activity (5 mg/kg morphine). We found that adult male rats, but not females who were exposed to peripubertal non‐social stressors showed enhanced morphine‐induced CPP. Moreover, morphine‐induced increase in locomotor activity was also significantly increased in adult male rats, but not in females. These results indicate that peripubertal exposure to repeated non‐social stress may enhance sensitivity to the rewarding effects of opioids in adulthood in a sex‐dependent manner, with males being even more sensitive than females in this regard.
Numbers and distribution of the Great Cormorant in Iceland: Limitation at the regional and metapopulation level
Authors: Gardarsson Arnthor , Jónsson Jón Einar 
Published: March 2019

AbstractWe studied a metapopulation of great cormorant(Phalacrocorax carbo)in Iceland, using complete aerial censuses of nests in 25 years during 1975–2015. Age composition was estimated in 1998–2014 by ground surveys in September and February. Brood size was estimated from aerial photographs in 2007–2015.Weather, food, breeding habitat, and density were considered as explanatory variables when examining numerical and distributional changes in the cormorant metapopulation.In 1975–1990 total nest numbers changed little, very low numbers about 1992 were followed by an annual increase of 3.5% in 1994–2015. Total nest numbers were positively correlated with estimates of spawning stocks of cod and saithe and inversely related to the subpolar gyre index (SPG‐I).During the increase in 1994–2015, average colony size at first increased and then declined. Habitat use also changed: the proportion of nests on small rocky islets (skerries) at first declined, from 69% to 44% in 1995–2003 and then increased again to about 58% in 2012–2014. Habitat changes were probably a response to changed patterns of human disturbance.Breeding density, as nests per km2sea <20 m deep, was rather uniform among five defined regions in 1975–1996. Thereafter, densities became much higher in two sheltered regions with kelp forests and in one mostly exposed region. A second exposed region remained low and in the third nest numbers declined markedly. Thus, carrying capacity was higher in sheltered regions where cormorant breeding had historically been depressed by human disturbance.Brood size varied little among regions but declined with the years from about 2.5 to 1.8.The proportion of juveniles in September (fecundity) declined in 1998–2015 from over 0.4 to 0.3 and was inversely correlated with year and nest numbers, if outlier years were excluded, suggesting resource limitation. Survival of juvenile cormorants in September–February was estimated at 0.471 ± 0.066 SE. Commercial fish stocks and climate indices were not correlated with the proportion of juveniles.Annual survival of adults (breeding and nonbreeding) was estimated from nest counts and age composition 1999–2014, as 0.850 ± 0.026 SEand showed no trend in 1998–2014.We conclude that the metapopulation of cormorants in Iceland was resource‐limited at two levels: fecundity at the regional and winter survival at the total level.
When to cut your losses: Dispersal allocation in an asexual filamentous fungus in response to competition
Authors: Chan Justin Y. , Bonser Stephen P. , Powell Jeff R. , Cornwell William K. 
Published: March 2019

Abstract

Fungal communities often form on ephemeral substrates and dispersal is critical for the persistence of fungi among the islands that form these metacommunities. Within each substrate, competition for space and resources is vital for the local persistence of fungi. The capacity to detect and respond by dispersal away from unfavorable conditions may confer higher fitness in fungi. Informed dispersal theory posits that organisms are predicted to detect information about their surroundings which may trigger a dispersal response. As such, we expect that fungi will increase allocation to dispersal in the presence of a strong competitor.

In a laboratory setting, we tested how competition with other filamentous fungi affected the development of conidial pycnidiomata (asexual fruiting bodies) in Phacidium lacerum over 10 days.

Phacidium lacerum was not observed to produce more asexual fruiting bodies or produce them earlier when experiencing interspecific competition with other filamentous fungi. However, we found that a trade‐off existed between growth rate and allocation to dispersal. We also observed a defensive response to specific interspecific competitors in the form of hyphal melanization of the colony which may have an impact on the growth rate and dispersal trade‐off.

Our results suggest that P. lacerum have the capacity to detect and respond to competitors by changing their allocation to dispersal and growth. However, allocation to defence may come at a cost to growth and dispersal. Thus, it is likely that optimal life history allocation in fungi constrained to ephemeral resources will depend on the competitive strength of neighbors surrounding them.