bluuebunny/crossref_metadata_2025 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

Industrial 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

Biobutanol 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

Anodic 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

A 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

Spirocyclic 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

Targeted 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

The 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

The 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

Establishing 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

NHC‐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

One 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

Various 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

Mass 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

Animal 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

We 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

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.
Response diversity in Mediterranean coralligenous assemblages facing climate change: Insights from a multispecific thermotolerance experiment
Authors: Gómez‐Gras Daniel , Linares Cristina , de Caralt Sonia , Cebrian Emma , Frleta‐Valić Maša , Montero‐Serra Ignasi , Pagès‐Escolà Marta , López‐Sendino Paula , Garrabou Joaquim
Published: March 2019

Climate change threatens coastal benthic communities on a global scale. However, the potential effects of ongoing warming on mesophotic temperate reefs at the community level remain poorly understood. Investigating how different members of these communities will respond to the future expected environmental conditions is, therefore, key to anticipating their future trajectories and developing specific management and conservation strategies. Here, we examined the responses of some of the main components of the highly diverse Mediterranean coralligenous assemblages to thermal stress. We performed thermotolerance experiments with different temperature treatments (from 26 to 29°C) with 10 species from different phyla (three anthozoans, six sponges and one ascidian) and different structural roles. Overall, we observed species‐specific contrasting responses to warming regardless of phyla or growth form. Moreover, the responses ranged from highly resistant species to sensitive species and were mostly in agreement with previous field observations from mass mortality events (MMEs) linked to Mediterranean marine heat waves. Our results unravel the diversity of responses to warming in coralligenous outcrops and suggest the presence of potential winners and losers in the face of climate change. Finally, this study highlights the importance of accounting for species‐specific vulnerabilities and response diversity when forecasting the future trajectories of temperate benthic communities in a warming ocean.
The more things change: species losses detected in Phoenix despite stability in bird–socioeconomic relationships
Authors: Warren Paige S. , Lerman Susannah B. , Andrade Riley , Larson Kelli L. , Bateman Heather L.
Published: March 2019

The science of urban ecology has increasingly grappled with the long‐term ramifications of a globally urbanized planet and the impacts on biodiversity. Some researchers have suggested that places with high species diversity in cities simply reflect an extinction debt of populations that are doomed to extinction but have not yet disappeared. The longitudinal studies conducted to date have found species composition shifting with urbanization but have not always documented continued species extirpations post‐urbanization. We used long‐term monitoring data on birds from the greater metropolitan area of Phoenix, Arizona, to measure changes in residential bird communities, species–habitat relationships, and human perceptions of bird species diversity over a five‐year period. Bird richness, occupancy, and abundance decreased, as did the percentage of respondents satisfied with bird variety in their neighborhoods. As in previous analyses for this region, we found that desert specialist species were associated with neighborhoods with xeric landscaping consisting of gravel groundcover, and drought‐tolerant, desert‐adapted vegetation. These species were also found in neighborhoods with high per capita income rates and lower percentages of renters and Hispanic/Latinx residents. Non‐native species were positively associated with neighborhoods containing mesic yards with grass and other water‐intensive vegetation. The proportions of yards in our surveyed neighborhoods with these distinct landscaping types likewise remained relatively stable over five‐year period. Although habitat–species relationships remained unchanged, we detected significant loss of species across the sampling period. Declines were not confined to desert specialist species but included generalist and invader species as well. The parallel reduction in residents’ satisfaction suggests that people perceive some aspect of this environmental degradation. Further investigation into the mechanisms underlying these species losses may reveal options for retaining some desert specialist species, and the uniqueness they contribute to urban fauna.
Haemodynamic simulation and the effect of early left ventricular unloading in pre‐shock acute coronary syndrome
Authors: Schäfer Andreas , Burkhoff Daniel , Bauersachs Johann
Published: March 2019

Aims

Understanding the pathophysiological background on haemodynamic changes in acute myocardial infarction and during its interventional treatment is important to adequately use mechanical circulatory support.

Methods and results

We describe haemodynamic simulations based on a real case scenario of infarct‐related ischaemia with beginning haemodynamic compromise illustrating the advantage of active haemodynamic support. The patient case used for computer simulation is that of an acute coronary syndrome, slightly hypotonic. The right coronary artery is chronically occluded, and both left main and a saphenous vein graft to the left anterior descending coronary artery (LAD) show subtotal stenosis. In this scenario used for computer modelling of haemodynamics, we illustrate how unprotected percutaneous coronary intervention would limit coronary blood flow and constantly reduce myocardial contractility until cardiac arrest occurs. The simulation demonstrates how an intra‐aortic balloon pump would delay but not prevent that compromise and how an Impella microaxial pump will actively support cardiac output and stabilize haemodynamics even when prolonged balloon inflations are performed, which will temporarily stop coronary perfusion.

Conclusions

The simulation illustrates how temporary circulatory support with an Impella microaxial pump can stabilize haemodynamics and allow for a safe procedure in an unstable patient. Using computer simulation of haemodynamics to understand changes in haemodynamics when performing interventions in unstable patients might help to properly select a suitable support device if needed.
An Inhospitable Cryptand: The Importance of Conformational Freedom in Host‐Guest Complexation
Authors: Gibson Harry W. , Huang Feihe , Zhao Run , Shao Li , Zakharov Lev N. , Slebodnick Carla , Rheingold Arnold L.
Published: March 2019

Two new cryptands were synthesized from bis(5‐bromomethyl‐1,3‐phenylene)‐32‐crown‐10 (4). The third arms, containing 19 or 21 atoms, were installed via Williamson ether syntheses with bisphenols containing 2,6‐disubstituted pyridines. 2,6‐Diaminopyridine was converted into the bis(p‐hydroxybenzoyl) derivative 3 for the first cryptand (5) and 2,6‐dicarboxypyridine was converted into the bis(p‐hydroxybenzylamide) 9 for the second cryptand (10). Cryptand 5 did not complex viologen derivatives 11–13 to an extent detectable by 1H NMR. We attribute the lack of complexation between viologen derivatives and 5 to its lack of conformational flexibility that prevents π‐stacking, a necessary component for complexation of viologens. In contrast longer and more flexible cryptand 10 did complex dimethyl paraquat (11) with Ka = 1.6 (±0.2) × 103 m–1 in acetone at 23 °C, probably by π‐stacking with the p‐oxybenzyl moieties of the host, made available by its enhanced flexibility.
Fluorescent Recognition of Functional Secondary Amines in the Fluorous Phase
Authors: Jiang Le , Tian Jun , Zhao Feng , Yu Shanshan , Shi Dan , Wang Xinjing , Yu Xiaoqi , Pu Lin
Published: March 2019

In a fluorous solvent (perfluorohexane, FC‐72), a perfluoroalkyl‐substituted 2‐hydroxy‐1‐naphthaldehyde (1) was found to show greatly enhanced fluorescence when treated with certain functional secondary amines but little fluorescence response was observed with unfunctional amines as well as functional primary and tertiary amines. The study of the reaction of 1 with 2‐methylamino ethanol (8) reveals a facile cyclocondensation of the aldehyde group of 1 with this 1,2‐amino alcohol to form a 5‐membered ring oxazolidine product which turns on the fluorescence. The reaction of 1 with the amino alcohol was found to be more favorable in the fluorous solvent than in a common organic solvent. The use of the fluorous phase‐based fluorescence measurement in this work provides a potentially more sensitive as well as selective method in amine sensing.
Challenging the Molecular Parameters of Vetiver: Can 4,5‐Dimethyl‐3‐(3′‐methylbut‐1′‐en‐2′‐yl)‐4‐phenylcyclopent‐2‐en‐1‐one Mimic Zizaenones in Structure and Odor?
Authors: Pfaff Patrick , Mouhib Halima , Kraft Philip
Published: March 2019

In order to investigate the molecular parameters of vetiver odorants and scrutinize the significance of ziza‐6(13)‐en‐3‐ones as structural templates in the design of new vetiver odorants, 4,5‐dimethyl‐3‐(3′‐methylbut‐1′‐en‐2′‐yl)‐4‐phenylcyclopent‐2‐en‐1‐one (10) was synthesized in 6 steps from cyclopentane‐1,3‐dione (20) following a Stork–Danheiser strategy after synthetic approaches by Ni‐catalyzed [3+2] annulation and enyne metathesis had failed. Addition of EtOH, α‐methylation of the resulting vinylogous ester 18, Pd‐catalyzed α‐arylation, and CeCl3·2LiCl mediated alkylation with (3‐methylbut‐1‐en‐2‐yl)lithium, generated by Shapiro reaction from the corresponding hydrazone 23, furnished after a concluding α‐methylation the target compound that possessed only a weak woody odor devoid of typical vetiver characteristics. While the design approach utilizing London dispersion forces could not reveal the secret of vetiver, it showed that the molecular parameters are far more complex than initially expected.
Thermodynamic analysis of energy storage supported multigeneration system
Authors: Okonkwo Eric C. , Adedeji Michael J. , Abid Muhammad , Ratlamwala Tahir A. H.
Published: March 2019

This article investigates the thermodynamic performance of a solar‐powered integrated multigeneration system with thermal storage. It aims at evaluating the effect of thermal storage on the overall performance of a multigeneration system. A solar heliostat field system, thermal energy storage, Rankine power cycle, electrolyzer, and a double effect absorption chiller make up the multigeneration system. Energy and exergy analyses of the system are performed, and the energy and exergy efficiencies are found to be 35.03% and 27.9%, respectively. The solar heliostat and receiver system obtained 3500 kW of heat, the thermal storage system had a thermal efficiency of 87.4% with the capacity to store 2700 kWth energy for 12 hours, the Rankine cycle produced 1068 kW of electricity and the electrolyzer which receives 20% of the net power produced was able to generate 0.0009035 kg/s of hydrogen. The absorption chiller also produced 271.9 kW of cooling. Furthermore, a parametric study was carried out to observe the effect of varying factors like direct normal irradiance (DNI), the mass fraction of the steam bled from the turbine (j), the pressure of the high‐temperature generator (HTG) inlet steam, and a combination of the DNI and the pressure of the HTG inlet steam on the system performance. While an increase in the DNI led to an improved thermal and exergetic efficiency, the addition of storage led to an increase of 27.7% in the utilization factor of the multigeneration system which means that the performance of the system is increased over time.
Investigation of the effect of using graded porosity on the thermal performance of the encapsulated ice thermal energy storage tank
Authors: Erdemir Dogan , Altuntop Necdet
Published: March 2019

The storage tank has great impact on the performance of ice thermal energy storage (ITES) system. Previous researches show that enhanced temperature gradient in the tank improves the thermal performance of system. This study deals with the investigation for determining the effect of using graded porosity in the storage tank of encapsulated ITES system. In this study, it was researched that the effects of uniform, two‐graded, and three‐graded porosities inside the storage tank. Energy equation in porous medium was solved analytically to determine the centerline temperature changing in the tank. At the end of study, it was found that the lower porosity supplied higher thermal performance. However, lower porosity requires higher tank volume. Graded porosity provided the almost equal thermal performance with lower uniformly distributed porosity, although it had a higher porosity. Energy efficiency values were very high and changed between 95.23% and 99.98% in all porosity structure and working conditions. On the contrary to the energy efficiency values, exergy efficiency values were changed over a wider range between 35.80% and 88.71%. The highest exergy efficiency of 88% was seen in ε = 0.4 uniform porosity. Also, (ε1 = 0.4, ε2 = 0.5) two‐graded porosity and (ε1 = 0.4, ε2 = 0.5, ε3 = 0.6) three‐graded porosity provided higher exergy efficiency. While exergy efficiency increased with increasing heat transfer fluid (HTF) flow rate, decreased with decreasing HTF inlet temperature.
Response to Spaniol and Rowland: “Defining Scenario”
Authors: Chermack Thomas J.
Published: March 2019

This article is a response to Spaniol and Rowland’s article “Defining Scenario”. Specifically this article responds to claims made in the categories of scenario definitions, scenario theory and scenario methods. The purpose is to engage in a thoughtful and collegial debate and it contains the raising of some issues the scenario community may wish to consider.
A network approach to prioritizing susceptibility genes for genome‐wide association studies
Authors: Kafaie Somayeh , Chen Yuanzhu , Hu Ting
Published: March 2019

The heritability of complex diseases including cancer is often attributed to multiple interacting genetic alterations. Such a non‐linear, non‐additive gene–gene interaction effect, that is, epistasis, renders univariable analysis methods ineffective for genome‐wide association studies. In recent years, network science has seen increasing applications in modeling epistasis to characterize the complex relationships between a large number of genetic variations and the phenotypic outcome. In this study, by constructing a statistical epistasis network of colorectal cancer (CRC), we proposed to use multiple network measures to prioritize genes that influence the disease risk of CRC through synergistic interaction effects. We computed and analyzed several global and local properties of the large CRC epistasis network. We utilized topological properties of network vertices such as the edge strength, vertex centrality, and occurrence at different graphlets to identify genes that may be of potential biological relevance to CRC. We found 512 top‐ranked single‐nucleotide polymorphisms, among which COL22A1, RGS7, WWOX, and CELF2 were the four susceptibility genes prioritized by all described metrics as the most influential on CRC.
Transforming growth factor‐beta renders ageing microglia inhibitory to oligodendrocyte generation by CNS progenitors
Authors: Baror Roey , Neumann Björn , Segel Michael , Chalut Kevin J. , Fancy Stephen P. J. , Schafer Dorothy P. , Franklin Robin J. M.
Published: March 2019

It is now well‐established that the macrophage and microglial response to CNS demyelination influences remyelination by removing myelin debris and secreting a variety of signaling molecules that influence the behaviour of oligodendrocyte progenitor cells (OPCs). Previous studies have shown that changes in microglia contribute to the age‐related decline in the efficiency of remyelination. In this study, we show that microglia increase their expression of the proteoglycan NG2 with age, and that this is associated with an altered micro‐niche generated by aged, but not young, microglia that can divert the differentiation OPCs from oligodendrocytes into astrocytes in vitro. We further show that these changes in ageing microglia are generated by exposure to high levels of TGFβ. Thus, our findings suggest that the rising levels of circulating TGFβ known to occur with ageing contribute to the age‐related decline in remyelination by impairing the ability of microglia to promote oligodendrocyte differentiation from OPCs, and therefore could be a potential therapeutic target to promote remyelination.
State ownership and international expansion: The S‐curve relationship
Authors: Kalasin Kiattichai , Cuervo‐Cazurra Alvaro , Ramamurti Ravi
Published: March 2019

Research Summary

We study how state ownership affects the international expansion of emerging‐market firms. Building on agency theory and the resource‐based view, we propose an S‐curve relationship: Firms with a low level of state ownership have a limited level of international expansion, those with a medium level of state ownership have an increasing level, and those with a high level of state ownership have a decreasing level. This S‐curve is the outcome of the interaction between the “hindering hand” of state ownership, arising from multilevel agency problems, and the “helping hand,” arising from state‐ownership advantages. Analyses of 674 publicly traded firms from 16 emerging markets support these ideas and reveal that the inflection points in the S‐curve appear at state‐ownership levels of 19 and 43%.

Managerial Summary

State ownership of emerging‐market firms results in their international expansion following an S‐curve pattern because state ownership has hindering and helping influences. Firms with low state ownership have a limited level of international expansion because they are subject to government interference but receive limited support. Firms with a medium level of state ownership have an increasing level of international expansion because they have greater access to resources while the negative effects of state control are restrained by the dominance of private owners. Finally, firms with a high level of state ownership have a decreasing level of international expansion because the advantage of resource provision is offset by tight state controls. We illustrate these ideas through the analyses of 674 firms from 16 emerging markets.
Microscopic positive margins strongly predict reduced disease‐free survival in pT4a papillary thyroid cancer
Authors: Abraham Earl , Roshan David , Tran Bryan , Graham Susannah , Lehane Christopher , Wykes James , Campbell Peter , Ebrahimi Ardalan
Published: March 2019

Background

Although microscopic positive margins appear to have no independent prognostic impact in papillary thyroid cancer (PTC), this may not be the case in pT4a tumors.

Methods

Retrospective analysis of 610 patients with PTC, 39 with pT4a tumors, to determine if microscopic positive margins impact disease‐free survival (DFS) in pT4a PTC.

Results

On univariate analysis, microscopic positive margins were not associated with reduced DFS in patients with no extrathyroidal extension (ETE) (hazard ratio [HR], 1.7; P = 0.32), microscopic ETE (HR, 1.6; P = 0.36), or macroscopic ETE limited to strap muscles (HR, 1.2; P = 0.87). In contrast, microscopic positive margins were associated with reduced DFS in T4a disease (HR, 4.1; P = 0.04). Disease recurrence was nodal, distant, or biochemical, and did not occur directly at the site of positive margins.

Conclusion

Although microscopic positive margins do not influence DFS in the majority of patients with PTC, they are associated with a fourfold increased risk of recurrence in pT4a disease.
Applying pragmatic approaches to complex program evaluation: A case study of implementation of the New South Wales Get Healthy at Work program
Authors: Crane Melanie , Bauman Adrian , Lloyd Beverley , McGill Bronwyn , Rissel Chris , Grunseit Anne
Published: March 2019

Issue addressed

Complex health promotion programs, which can have multilevels of implementation and multi‐components with nonlinear causal pathways, present many evaluation challenges. Traditional evaluation methods often fail to account for the complexity inherent in assessing these programs. In real‐world settings, evaluations of complex programs are often beset by additional constraints of limited budgets and short timeframes. Determining whether a complex program is successful and how a program worked requires evaluators of complex programs to adopt a level of pragmatism.

Methods

This paper describes a pragmatic evaluation approach used to evaluate the Get Healthy at Work workplace health promotion program, implemented in New South Wales, Australia. Using the program as a case study, we describe some key principles for applying a pragmatic evaluation approach and use these principles to develop an appropriate evaluation strategy.

Results

The evaluation includes multiple research methods to assess program outputs and implementation; and identify emergent program impacts, within constrained resources. The evaluation was guided by epistemological flexibility, methodological comprehensiveness and operational practicality.

Conclusion

Health promotion programs, such as state‐wide obesity prevention programs, require appropriate evaluation methods which address their inherent complexity amidst the real‐world evaluation constraints, and focuses on the essential evaluation needs.

So what

The main complex program evaluation principles are applicable to other multilevel health promotion programs, challenged by methodological and practical or political constraints.
Second law analysis in radiative mixed convective squeezing flow of Casson fluid between parallel disks with Soret and Dufour effects
Authors: Ramesh Kesetti , Ojjela Odelu , Nareshkumar N.
Published: March 2019

The present communication deals the entropy generation by cause of heat and mass transform in an unsteady mixed convective radiative squeezing flow of a Casson fluid confined between two parallel disks in the presence of diffusion‐thermo and thermal‐diffusion effects and temperature jump. The lower disk is taken to be porous and the upper one is impermeable. The governing PDE is converted as nonlinear ordinary differential equations (ODE) by using well‐established similarity transformations; then, the reduced nonlinear ODE are solved by shooting method with Runge‐Kutta fourth‐order approach. The influence of distinct nondimensional fluid and geometric‐related parameters on the velocity profiles, temperature, concentration, entropy generation number, and Bejan number are studied in detail and represented in the form of graphs. The entropy of the Casson fluid is increased with the Eckert number, whereas the concentration profile is decreased by squeezing Reynolds number. The current results are correlated with existing results for the viscous case and found to be in better agreement.
A new empirical correlating equation for calculating effective viscosity of nanofluids
Authors: Dhahri Maher , Aouinet Hana , sammouda Habib
Published: March 2019

In this paper, an empirical correlation for the nanofluid viscosity is proposed. The new equation for the nanofluid effective dynamic viscosity, normalized by the dynamic viscosity of the base liquid, is derived from a wide selection of experimental data available in the literature. This correlation presented the viscosity of the nanofluid as a function of the base fluid viscosity, nanoparticle volume fraction, nanoparticle diameter, nanoparticle temperature, and mass density of the base fluid. The new correlation was evaluated against 898 experimental data for the viscosities of nanofluid collected from the literature. The experimental data included different working nanofluids, such as alumina, Iron, and silica, where the diameter of nanoparticles was ranging between 10 and 350 nm, suspended in water, propylene glycol, and kerosene. The predicted results were then compared with many other published experimental results for different nanofluids and very good concordance between these results was observed. In general, this correlation has higher accuracy and precision.