bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxygen diffusion in ellipsoidal tumour spheroids
Authors: Grimes David Robert , Currell Frederick J.
Published: August 2018

Oxygen plays a central role in cellular metabolism, in both healthy and tumour tissue. The presence and concentration of molecular oxygen in tumours has a substantial effect on both radiotherapy response and tumour evolution, and as a result the oxygen micro-environment is an area of intense research interest. Multi-cellular tumour spheroids closely mimic real avascular tumours, and in particular they exhibit physiologically relevant heterogeneous oxygen distribution. This property has made them a vital part of
in vitro
experimentation. For ideal spheroids, their heterogeneous oxygen distributions can be predicted from theory, allowing determination of cellular oxygen consumption rate (OCR) and anoxic extent. However, experimental tumour spheroids often depart markedly from perfect sphericity. There has been little consideration of this reality. To date, the question of how far an ellipsoid can diverge from perfect sphericity before spherical assumptions break down remains unanswered. In this work, we derive equations governing oxygen distribution (and, more generally, nutrient and drug distribution) in both prolate and oblate tumour ellipsoids, and quantify the theoretical limits of the assumption that the spheroid is a perfect sphere. Results of this analysis yield new methods for quantifying OCR in ellipsoidal spheroids, and how this can be applied to markedly increase experimental throughput and quality.
Drawing power of virtual crowds
Authors: Jorjafki Elham Mohammadi , Sagarin Brad J. , Butail Sachit
Published: August 2018

In 1969, social psychologist Milgram and his colleagues conducted an experiment on a busy city street where passers-by witnessed a set of actors spontaneously looking up towards a building. The experiment showed that the crowd's propensity to mimic the actor's gaze increased with the number of actors that looked up. This form of behavioural contagion is found in many social organisms and is central to how information travels through large groups. With the advancement of virtual reality and its continued application towards understanding human response to crowd behaviour, it remains to be verified if behavioural contagion occurs in walkable virtual environments, and how it compares with results from real-world experiments. In this study, we adapt Milgram's experiment for virtual environments and use it to reproduce behavioural contagion. Specifically, we construct a replica of an indoor location and combine two established pedestrian motion models to create an interactive crowd of 60 virtual characters that walk through the indoor location. The stimulus group comprised a subset of the characters who look up at a random time as the participants explore the virtual environment. Our results show that the probability of looking up by a participant is dependent on the size of the stimulus group saturating to near certainty when three or more characters look up. The role of stimulus size was also evident when participant actions were compared with survey responses which showed that more participants selected to not look up even though they saw characters redirect their gaze upwards when the size of the stimulus group was small. Participants also spent more time looking up and exhibited frequent head turns with a larger stimulus group. Results from this study provide evidence that behavioural contagion can be triggered in the virtual environment, and can be used to build and test complex hypotheses for understanding human behaviour in a variety of crowd scenarios.
Convex skeletons of complex networks
Authors: Šubelj Lovro
Published: August 2018

A convex network can be defined as a network such that every connected induced subgraph includes all the shortest paths between its nodes. A fully convex network would therefore be a collection of cliques stitched together in a tree. In this paper, we study the largest high-convexity part of empirical networks obtained by removing the least number of edges, which we call a convex skeleton. A convex skeleton is a generalization of a network spanning tree in which each edge can be replaced by a clique of arbitrary size. We present different approaches for extracting convex skeletons and apply them to social collaboration and protein interactions networks, autonomous systems graphs and food webs. We show that the extracted convex skeletons retain the degree distribution, clustering, connectivity, distances, node position and also community structure, while making the shortest paths between the nodes largely unique. Moreover, in the Slovenian computer scientists coauthorship network, a convex skeleton retains the strongest ties between the authors, differently from a spanning tree or high-betweenness backbone and high-salience skeleton. A convex skeleton thus represents a simple definition of a network backbone with applications in coauthorship and other social collaboration networks.
Synthesis of citric acid-modified resins and their adsorption properties towards metal ions
Authors: Liu Xiong , Xu Longqi , Liu Yaqing , Zhou Wenqi
Published: August 2018

Types of resins anchored on citric acid were synthesized and identified. The citric acid-modified resins PS-CA, PS-O-CA and PS-N-CA were synthesized by anchoring citric acid on PS-Cl, PS-OH and PS-NH
2
, respectively. The PS-CA, PS-O-CA and PS-N-CA were used to adsorb Fe
3+
, Al
3+
, Cu
2+
, Pb
2+
, Cd
2+
and Hg
2+
. The influences of pH, adsorption time and metal ion concentration on the adsorption capacities of the resins were investigated. After optimization, PS-CA was a good adsorbent to Fe
3+
, Cu
2+
, Pb
2+
and Cd
2+
with

q
m

values of 143.9 mg g
−1
, 77.4 mg g
−1
, 18.9 mg g
−1
and 119.9 mg g
−1
, respectively. PS-N-CA was a good adsorbent to Al
3+
and Hg
2+
with

q
m

values of 176.6 mg g
−1
and 114.9 mg g
−1
, respectively. The adsorption kinetics and adsorption isotherm experiments indicated that the pseudo-first-order rate equation was more appropriate for characterizing the kinetic data and the Langmuir model was more suitable for fitting the equilibrium data. The reusability of the citric acid-modified resins was also evaluated and these resins exhibited considerable reusability.
Seasonal characteristics of phosphorus sorption by sediments from plain lakes with different trophic statuses
Authors: Huang Wei , Chen Xing , Wang Kun , Jiang Xia
Published: August 2018

Phosphorus (P) sorption in sediments plays a significant role in trophic status of a lake. This study investigated the characteristics of P sorption in sediments from three lakes with different trophic statuses (moderately eutrophic, lightly eutrophic and moderately trophic) through kinetic, batch equilibrium and thermodynamic experiments. Results show that pseudo-second-order kinetics best describe P sorption in sediments from the three lakes. Fitting by modified Langmuir and Freundlich isotherms indicates that the moderately trophic lake sediment has higher sorption capacity (maximum of 0.848 mg g
−1
at 35°C) than the sediments of the other two lakes at different temperatures (5, 15, 25 and 35°C). Thermodynamic results indicate that the processes of P sorption of the three sediments are spontaneous, entropy-driven and endothermic reactions. The risk of P release in sediments was analysed according to the calculated results of isotherms combined with the change in P fraction. Sediments from the moderately eutrophic lake act as a source in summer. The lightly eutrophic and moderately trophic lakes act as sources in spring and winter, and a pool in summer and autumn, respectively. Furthermore, the amounts of reductant-soluble P, calcium-bound P and iron-bound P are significantly related to the sorption capacity of sediments from the three lakes (
p
< 0.05). The different sediments have different P release risk, and P fraction in sediment is one of the significant factors of P sorption.
Improved mould resistance and antibacterial activity of bamboo coated with ZnO/graphene
Authors: Wang Jin , Li Jingpeng , Zhuang Xiaowei , Pan Xin , Yu Haixia , Sun Fangli , Song Jiangang , Jin Chunde , Jiang Yingti
Published: August 2018

Bamboo is susceptible to mould and attack by fungi because of its high content of starch and sugar. To make bamboo-based outdoor materials, a new type of bamboo timber with improved mould resistance and antibacterial activity, coated with reduced graphene oxide and nanocrystal ZnO (abbreviated as RGO@ZnOBT), was fabricated by a two-step dip-dry and hydrothermal process. A possible synthesis mechanism for RGO@ZnOBT was investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscope, energy-dispersal X-ray analysis, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. According to the China standard test method, the
Aspergillus niger
mould resistance of RGO@ZnOBT is grade 2, whereas the
Trichoderma viride
and
Penicillium citrinum
mould resistance of RGO@ZnOBT is grade 0, both of which are better than the grade 4 of original bamboo timber. The
Escherichia coli
resistance test showed that the antibacterial circle of RGO@ZnOBT is 3 mm, which is significantly higher than that of original bamboo timber (0 mm). The antibacterial activity of treated bamboo is significantly improved compared with that of untreated bamboo.
NiS submicron cubes with efficient electrocatalytic activity as the counter electrode of dye-sensitized solar cells
Authors: Yu Qiongzhe , Pang Yashuai , Jiang Qiwei
Published: August 2018

In this work, nickel sulfide (NiS) submicron cubes, synthesized by an easy hydrothermal method, were investigated as an efficient electrocatalytic material of dye-sensitized solar cells (DSSCs), to our knowledge, for the first time. Part of the NiS submicron cubes were grown together in a hydrothermal procedure and formed the connected submicron cube cluster. The NiS submicron cubes (with a diameter of 300–800 nm) showed excellent electrocatalytic activity and presented superior photovoltaic performance when it was used as an electrocatalytic material for the counter electrode (CE) of DSSCs. The CE composed of the NiS submicron cubes could achieve a photovoltaic efficiency of 6.4%, showing their superior performance compared with the typical Pt electrode (which with the corresponding conversion efficiency was 5.3% at the same condition). The low-cost NiS submicron cube electrode could be a competitive candidate to replace the traditional Pt electrode in DSSCs. The simple composition procedure of NiS submicron cubes could enable the low-cost mass production of an efficient NiS submicron cube electrode to be easily accomplished.
Revisiting behaviour of monometallic catalysts in chemical vapour deposition synthesis of single-walled carbon nanotubes
Authors: Xiang Rong , Maruyama Shigeo
Published: August 2018

A catalyst is essential for the controlled synthesis of single-walled carbon nanotubes (SWNTs) by chemical vapour deposition (CVD). However, it is difficult to observe these nanosized particles in their original forms and in a statistical manner, which has resulted in a vague understanding of the behaviours of these particles. We present a technique to solve this long-standing issue. The key is to have an MEMS fabricated suspended SiO
2
layer, which is thick enough to support catalyst deposition and nanotube growth but thin enough to allow electron beams to transit. On a 20 nm SiO
2
film, we confirm that catalyst can be observed at an atomic resolution, and the catalyst–SWNT junctions can also be routinely observed. As a demonstration of this technique, we revisited the behaviour of monometallic catalysts through a systematic investigation of the size, chemical state and crystal structure of particles before and after high-temperature CVD. The active catalyst is found to follow a tangential growth mode, while the inactive catalyst is divided into three mechanisms: size growth, metal loss and inappropriate precipitation. The latter two mechanisms were not possible to observe by previous techniques.
Data availability, reusability, and analytic reproducibility: evaluating the impact of a mandatory open data policy at the journal
Cognition
Authors: Hardwicke Tom E. , Mathur Maya B. , MacDonald Kyle , Nilsonne Gustav , Banks George C. , Kidwell Mallory C. , Hofelich Mohr Alicia , Clayton Elizabeth , Yoon Erica J. , Henry Tessler Michael , Lenne Richie L. , Altman Sara , Long Bria , Frank Michael C.
Published: August 2018

Access to data is a critical feature of an efficient, progressive and ultimately self-correcting scientific ecosystem. But the extent to which in-principle benefits of data sharing are realized in practice is unclear. Crucially, it is largely unknown whether published findings can be reproduced by repeating reported analyses upon shared data (‘analytic reproducibility’). To investigate this, we conducted an observational evaluation of a mandatory open data policy introduced at the journal
Cognition
. Interrupted time-series analyses indicated a substantial post-policy increase in data available statements (104/417, 25% pre-policy to 136/174, 78% post-policy), although not all data appeared reusable (23/104, 22% pre-policy to 85/136, 62%, post-policy). For 35 of the articles determined to have reusable data, we attempted to reproduce 1324 target values. Ultimately, 64 values could not be reproduced within a 10% margin of error. For 22 articles all target values were reproduced, but 11 of these required author assistance. For 13 articles at least one value could not be reproduced despite author assistance. Importantly, there were no clear indications that original conclusions were seriously impacted. Mandatory open data policies can increase the frequency and quality of data sharing. However, suboptimal data curation, unclear analysis specification and reporting errors can impede analytic reproducibility, undermining the utility of data sharing and the credibility of scientific findings.
The shark-tuna dichotomy: why tuna lay tiny eggs but sharks produce large offspring
Authors: Sibly Richard M. , Kodric-Brown Astrid , Luna Susan M. , Brown James H.
Published: August 2018

Teleosts such as tunas and billfish lay millions of tiny eggs weighing on the order of 0.001 g, whereas chondrichthyes such as sharks and rays produce a few eggs or live offspring weighing about 2% of adult body mass, as much as 10 000 g in some species. Why are the strategies so extreme, and why are intermediate ones absent? Building on previous work, we show quantitatively how offspring size reflects the relationship between growth and death rates. We construct fitness contours as functions of offspring size and number, and show how these can be derived from juvenile growth and survivorship curves. Convex contours, corresponding to Pearl Type 1 and 2 survivorship curves, select for extremes, either miniscule or large offspring; concave contours select for offspring of intermediate size. Of particular interest are what we call critical straight-line fitness contours, corresponding to log-linear Pearl Type 3 survivorship curves, which separate regimes that select for opposite optimal offspring sizes.
Species’ ecological functionality alters the outcome of fish stocking success predicted by a food-web model
Authors: Uusi-Heikkilä Silva , Perälä Tommi , Kuparinen Anna
Published: August 2018

Fish stocking is used worldwide in conservation and management, but its effects on food-web dynamics and ecosystem stability are poorly known. To better understand these effects and predict the outcomes of stocking, we used an empirically validated network model of a well-studied lake ecosystem. We simulate two stocking scenarios with two native fish species valuable for fishing. In the first scenario, we stock planktivorous fish (whitefish) larvae in the ecosystem. This leads to a 1% increase in adult whitefish biomasses and decreases the biomasses of the top predator (perch). In the second scenario, we also stock perch larvae in the ecosystem. This decreases the planktivorous whitefish and the oldest top predator age class biomasses, and destabilizes the ecosystem. Our results demonstrate that the effects of stocking depend on the species' position in the food web and thus cannot be assessed without considering interacting species. We further show that stocking can lead to undesired outcomes from both management and conservation perspectives. The gains of stocking can remain minor and have adverse effects on the entire ecosystem.
A giant dapediid from the Late Triassic of Switzerland and insights into neopterygian phylogeny
Authors: Latimer Ashley E. , Giles Sam
Published: August 2018

A new Triassic neopterygian is described on the basis of a large three-dimensional neurocranium from the Rhaetian (Late Triassic) of the Kössen Formation (Schesaplana, Grisons, Switzerland). CT scanning reveals neurocranial features similar toDapedium, suggesting that this new genus,Scopulipiscis saxciputgen. et sp. nov., was deep-bodied and potentially durophagous, although no associated dental material is known. An expanded phylogenetic analysis of actinopterygians resolves Dapediidae as a clade (inclusive ofTetragonolepis), although fails to recover any characters supporting the monophyly of the genusDapedium. Dapediids are resolved as stem holosteans, filling a conspicuous gap in early neopterygian relationships. Pycnodonts, previously suggested as either stem teleosts or the sister group to dapediids, are resolved as a clade on the neopterygian stem. Similarities between the new taxon described here andDapediumprovide insights into morphological disparity within early members of the group—suggesting that the ecological expansion of dapediids originated prior to the End-Triassic extinction—as well as contributing to a growing understanding of endocranial anatomy in Palaeozoic and Early Mesozoic actinopterygians.
Enhanced cycle stability of a NiCo
2
S
4
nanostructured electrode for supercapacitors fabricated by the alternate-dip-coating method
Authors: Kang Jinhyeon , Yim Sanggyu
Published: August 2018

Nanostructured nickel cobalt sulfide (NiCo
2
S
4
) electrodes are successfully fabricated using a simple alternate-dip-coating method. The process involves dipping a TiO
2
nanoparticles-covered substrate in a nickel/cobalt precursor solution and sulfur precursor solution alternately at room temperature. The fabricated bimetallic sulfide electrode exhibits a synergetic improvement compensating for the disadvantages of the two single metal sulfide electrodes, i.e. the poor cycle stability of the nickel sulfide electrode and the low specific capacitance (
C
sp
) of the cobalt sulfide electrode. The two capacitive properties are optimized by adjusting the ratio of nickel and cobalt concentrations in the metal precursor solution, reaching a
C
sp
of 516 F g
−1
at a current density of 1 mA cm
−2
, with its retention being 99.9% even after 2000 galvanostatic charge–discharge cycles.
Solution properties and aggregating structures for a fluorine-containing polymeric surfactant with a poly(ethylene oxide) macro-monomer
Authors: Wu Xiaogang , Zhong Chuanrong , Lian Xiaofei , Yang Yan
Published: August 2018

A polymeric surfactant (PFSA) was synthesized by the aqueous free-radical copolymerization using acrylamide, sodium 2-acrylamido-2-methylpropane sulfonate, allyl-capped octylphenoxy poly(ethylene oxide) (PEO) with the polymerization degree of 20 (AOP) and 1H,1H,2H,2H-perfluoro-1-decylp-vinylbenzyl ether (VF). PFSA exhibited both the good surface and interfacial activities and the thickening behaviour. It could be used in enhanced oil recovery to increase both sweep and oil displacement efficiencies. The critical micelle concentration (CMC) of PFSA was 0.1 g l−1in aqueous solution. The spherical micelles with the diameter of 100 nm were formed at CMC, and numerous compact worm-shaped micelles were observed above CMC. The interfacial tension was 0.027 mN m−1for the 0.1 g l−1PFSA solution containing 5 g l−1NaCl and 0.209 g l−1SDBS. The PFSA solutions still showed low interfacial tensions at high NaCl concentrations and temperatures, respectively, because of the incorporation of both VF and AOP containing long PEO.
Incorporation of reduced graphene oxide into faceted flower-like {001} TiO
2
for enhanced photocatalytic activity
Authors: Liu Haijin , Li Peiyao , Bai Haokun , Du Cuiwei , Wei Dandan , Su Yuzhao , Wang Yuqian , Yang Lin
Published: August 2018

Anatase TiO
2
with {001} facets is much more active than that with {101} facets, which has been verified via experiments and theoretical calculations. Graphene has garnered much attention since it was initially synthesized, due to its unique properties. In this study, reduced graphene oxide (RGO)/{001} faceted TiO
2
composites were fabricated via a solvothermal method. The composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectrophotometry, photoluminescence and Raman analysis. The results revealed that the graphene oxide was reduced during the preparation process of the {001} faceted TiO
2
, and combined with the surface of {001} TiO
2
. The photocatalytic activities of the composites were evaluated through the degradation of basic violet, under both white light (
λ
> 390 nm) and visible light (
λ
= 420 nm) irradiation. The results indicated that the photocatalytic activities of the {001} faceted TiO
2
were significantly improved following the incorporation of RGO, particularly under visible light irradiation. Theoretical calculations showed that the band structure of the {001} faceted TiO
2
was modified via graphene hybridization, where the separation of photoinduced electron–hole pairs was promoted; thus, the photocatalytic activity was enhanced.
Zebrafish aggression on the sub-second time scale: evidence for mutual motor coordination and multi-functional attack manoeuvres
Authors: Laan Andres , Iglesias-Julios Marta , de Polavieja Gonzalo G.
Published: August 2018

Most animals fight by repeating complex stereotypic behaviours, yet the internal structure of these behaviours has rarely been dissected in detail. We characterized the internal structure of fighting behaviours by developing a machine learning pipeline that measures and classifies the behaviour of individual unmarked animals on a sub-second time scale. This allowed us to quantify several previously hidden features of zebrafish fighting strategies. We found strong correlations between the velocity of the attacker and the defender, indicating a dynamic matching of approach and avoidance efforts. While velocity matching was ubiquitous, the spatial dynamics of attacks showed phase-specific differences. Contest-phase attacks were characterized by a paradoxical sideways attraction of the retreating animal towards the attacker, suggesting that the defender combines avoidance manoeuvres with display-like manoeuvres. Post-resolution attacks lacked display-like features and the defender was avoidance focused. From the perspective of the winner, game-theory modelling further suggested that highly energetically costly post-resolution attacks occurred because the winner was trying to increase its relative dominance over the loser. Overall, the rich structure of zebrafish motor coordination during fighting indicates a greater complexity and layering of strategies than has previously been recognized.
Effects of azo dye on simultaneous biological removal of azo dye and nutrients in wastewater
Authors: Chen Aihui , Yang Bairen , Zhou Yuanqiang , Sun Yuze , Ding Cheng
Published: August 2018

The potential disrupting effects of Azo dye on wastewater nutrients removal deserved more analysis. In this study, 15 days exposure experiments were conducted with alizarin yellow R (AYR) as a model dye to determine whether the dye caused adverse effects on biological removal of both the dye and nutrients in acclimated anaerobic–aerobic–anoxic sequencing batch reactors. The results showed that the AYR removal efficiency was, respectively, 85.7% and 66.8% at AYR concentrations of 50 and 200 mg l
−1
, while higher AYR inlet (400 mg l
−1
) might inactivate sludge. Lower removal of AYR at 200 mg l
−1
of AYR was due to the insufficient support of electron donors in the anaerobic process. However, the decolorized by-products
p
-phenylenediamine and 5-aminosalicylic were completely decomposed in the following aerobic stage at both 50 and 200 mg l
−1
of AYR concentrations. Compared with the absence of AYR, the presence of 200 mg l
−1
of AYR decreased the total nitrogen removal efficiency from 82.4 to 41.1%, and chemical oxygen demand (COD) removal efficiency initially decreased to 68.1% and then returned to around 83.4% in the long-term exposure time. It was also found that the inhibition of AYR, nitrogen and COD removal induced by a higher concentration of AYR was due to the increased intracellular reactive oxygen species production, which caused the rise of oxidation–reduction potential value and decreased ammonia monooxygenase and nitrite oxidoreductase activities.
Porous poly-
l
-lactide-co-ɛ-caprolactone scaffold: a novel biomaterial for vaginal tissue engineering
Authors: Sartoneva Reetta , Kuismanen Kirsi , Juntunen Miia , Karjalainen Sanna , Hannula Markus , Kyllönen Laura , Hyttinen Jari , Huhtala Heini , Paakinaho Kaarlo , Miettinen Susanna
Published: August 2018

The surgical reconstruction of functional neovagina is challenging and susceptible to complications. Therefore, developing tissue engineering-based treatment methods for vaginal defects is important. Our aim was to develop and test a novel supercritical carbon dioxide foamed poly-
l
-lactide-co-ɛ-caprolactone (scPLCL) scaffold for vaginal reconstruction. The scaffolds were manufactured and characterized for porosity (65 ± 4%), pore size (350 ± 150 µm) and elastic modulus (2.8 ± 0.4 MPa). Vaginal epithelial (EC) and stromal cells (SC) were isolated, expanded and characterized with flow cytometry. Finally, cells were cultured with scPLCL scaffolds in separate and/or co-cultures. Their attachment, viability, proliferation and phenotype were analysed. Both cell types strongly expressed cell surface markers CD44, CD73 and CD166. Strong expression of CD326 was detected with ECs and CD90 and CD105 with SCs. Both ECs and SCs attached and maintained viability on scPLCL. Further, scPLCL supported the proliferation of especially ECs, which also maintained epithelial phenotype (cytokeratin expression) during 14-day assessment period. Interestingly, ECs expressed uroplakin (UP) Ia, UPIb and UPIII markers; further, UPIa and UPIII expression was significantly higher on ECs cultured on scPLCL than on cell culture plastic. In conclusion, the scPLCL is potential scaffold for vaginal tissue engineering and the results of this study further illustrate the excellent biocompatibility of PLCL.
Castor oil: a suitable green source of capping agent for nanoparticle syntheses and facile surface functionalization
Authors: Mensah M. B. , Awudza J. A. M. , O'Brien P.
Published: August 2018

Castor oil (CO) is an inedible vegetable oil (VO) that has been employed extensively as a bioresource material for the synthesis of biodegradable polymers, cosmetics, lubricants, biofuels, coatings and adhesives. It is used in medicine, pharmaceuticals and biorefineries, due to its versatile chemistry. However, there has been less focus on CO as an alternative to toxic and expensive solvents, and capping/stabilizing agents routinely used in nanoparticle syntheses. It provides a richer chemistry than edible VOs as a solvent for green syntheses of nanoparticles. CO, being the only rich source of ricinoleic acid (RA), has been used as a solvent, co-solvent, stabilizing agent and polyol for the formation of polymer–nanoparticle composites. RA is a suitable alternative to oleic acid used as a capping and/or stabilizing agent. Unlike oleic acid, it provides a facile route to the functionalization of surfaces of nanoparticles and the coating of nanoparticles with polymers. For applications requiring more polar organic solvents, RA is more preferred than oleic acid. In this review, we discuss the production, chemical and physical properties, triglyceride and fatty acid (FA) compositions and applications of CO, focusing on the use of CO and RA as well as other VOs and FAs in syntheses of nanoparticles and surface functionalization.
Fixation of CO
2
along with bromopyridines on a silver electrode
Authors: Zhang Yingtian , Yu Shuxian , Luo Peipei , Xu Shisong , Zhang Xianxi , Zhou Huawei , Du Jiyuan , Yang Jie , Xin Nana , Kong Yuxia , Liu Junhai , Chen Baoli , Lu Jiaxing
Published: August 2018

Resulting from the drastic increase of atmospheric CO
2
concentration day by day, global warming has become a serious environmental issue nowadays. The fixation of CO
2
to obtain desirable, economically competitive chemicals has recently received considerable attention. This work investigates the fixation of CO
2
along with three bromopyridines via a facile electrochemical method using a silver cathode to synthesize picolinic acids, which are important industrial and fine chemicals. Cyclic voltammetry is employed to investigate the cyclic voltammetric behaviour of bromopyridines. In addition, systematic study is conducted to study the relationships between the picolinic acids' yield and the electrolysis conditions and intrinsic parameters. The results show that the target picolinic acids' yields are strongly dependent on various conditions such as solvent, supporting electrolyte, current density, cathode material, charge passed, temperature and the nature of the substrates. Moreover, in the studied electrode materials such as Ag, Ni, Ti, Pt and GC, electrolysis and cyclic voltammetry show that Ag has a good electrocatalytic effect on the reduction and carboxylation of bromopyridine. This facile electrochemical route for fixation of CO
2
provides an indispensable reference for the conversion and utilization of CO
2
under mild conditions.
Editorial for ‘New talent’ collection: introducing New Talent in chemistry and material science
Authors: Sanders Jeremy K. M. , Stace Anthony
Published: August 2018

We introduce 14 articles published as part of the ‘New talent’ special collection of invited articles to showcase some of the exciting work being funded by the Royal Society. As Royal Society University Research Fellows or Dorothy Hodgkin Fellowship holders, the contributors to this collection are rising stars in their areas of research. This collection also illustrates the close collaboration between
Royal Society Open Science
and the Royal Society of Chemistry. The collection spans the range of the chemical and material sciences, reflecting the breadth of research areas receiving Royal Society grant support.
Mortality attributable to seasonal influenza in Greece, 2013-2017: variation by type and age, and a possible harvesting effect
Authors: Lytras Theodore , Pantavou Katerina , Mouratidou Elisavet , Tsiodras Sotirios
Published: August 2018

BACKGROUND

Estimating the contribution of influenza to excess mortality in the population presents substantial methodological challenges. We combined environmental, epidemiological and laboratory surveillance data to estimate influenza-attributable mortality in Greece, over four seasons (2013-2014 to 2017-2018), specifically addressing the lag dimension and the confounding effect of temperature.

METHODS

Associations of influenza type-specific incidence proxies and of daily mean temperature with mortality were estimated with a distributed-lag non-linear model with 30 days of maximum lag, separately for each age group. Total and weekly deaths attributable to influenza and cold temperatures were calculated.

RESULTS

Overall influenza-attributable mortality was 23.6 deaths per 100,000 population (95%CI: 17.8, 29.2), and varied greatly between seasons, by influenza type and by age group, with the vast majority occurring in persons 65 years or older. Most deaths were attributable to A/H3N2, followed by type B influenza. During periods of A/H1N1 circulation, weekly attributable mortality to this subtype among older people increased rapidly in the first half, but then fell to zero and even negative, suggesting a mortality displacement (harvesting) effect. Mortality attributable to non-optimum temperatures was much higher than that attributable to influenza.

CONCLUSIONS

Studies of influenza-attributable mortality need to take distributed-lag effects into account, stratify by age group and adjust for circulating influenza types and daily mean temperatures, in order to produce reliable estimates. Our approach is useful and readily applicable in the context of influenza surveillance.
The Metabotropic Glutamate Receptor 5 Negative Allosteric Modulator Fenobam: Pharmacokinetics, Side Effects, and Analgesic Effects in Healthy Human Subjects
Authors: Cavallone Laura F. , Montana Michael C. , Frey Karen , Kallogjeri Dorina , Wages James M. , Rodebaugh Thomas. , Doshi Tina , Kharasch Evan D. , Gereau Robert W.
Published: August 2018

Metabotropic glutamate receptor 5 (mGlu5) has been shown to modulate nociception in animals, but no mGlu5 antagonists have been developed commercially as analgesics. The mGlu5 antagonist fenobam [N-(3-chlorophenyl)-N’-(4,5-dihydro-1-methyl-4-oxo-1H-imidazole-2-yl)urea] was originally evaluated for development as a non-benzodiazepine anxiolytic. Fenobam is analgesic in numerous mouse pain models, acting exclusively via mGlu5 blockade. Furthermore, fenobam showed no signs of analgesic tolerance with up to two weeks of daily dosing in mice. Analgesic effects of fenobam in humans have not been reported. The purpose of this investigation was to evaluate fenobam pharmacokinetics and analgesic effects in humans. We first evaluated single-dose oral fenobam disposition in a parallel-group dose-escalation study in healthy volunteers. A second investigation tested the analgesic effects of fenobam in an established experimental human pain model of cutaneous sensitization utilizing capsaicin cream and heat, in a double-blind placebo-controlled study. The primary outcome measure was the area of hyperalgesia and allodynia around the area applied with heat/capsaicin. Secondary outcome measures included nociception, measured as pain rating on a visual analog scale, heat-pain detection threshold, and effects on cognition and mood. Fenobam plasma exposures showed considerable inter-individual variability, and were not linear with dose. Fenobam reduced sensitization vs placebo at a single time-point (peak plasma concentration); we found no other difference between fenobam and placebo. Our results suggest highly variable fenobam disposition, and minimal analgesic effects at the dose tested. We suggest that future studies testing analgesic effects of mGlu5 blockade are warranted, but such studies should employ molecules with improved pharmacokinetic profiles.
Biological control protects tropical forests
Authors: Wyckhuys K.A.G. , Hughes A.C. , Buamas C. , Johnson A.C. , Vasseur L. , Reymondin L. , Deguine J.P. , Sheil D.
Published: August 2018

Biological control of invasive species can restore crop yields, and thus ease land pressure and contribute to forest conservation. In this study, we show how biological control against the mealybug Phenacoccus manihoti (Hemiptera) slowed deforestation across Southeast Asia. In Thailand, the newly-arrived mealybug caused an 18% decline in cassava yields over 2009-2010, a shortfall in national production and an escalation in the price of cassava products. This spurred an expansion of cassava cropping in neighboring countries from 713,000 ha in 2009 to >1 million ha by 2011: satellite imagery reveal 388%, 330%, 185% and 608% increases in peak deforestation rates in Cambodia, Lao PDR, Myanmar and Viet Nam focused in cassava crop expansion areas. Following release of the host-specific natural enemy Anagyrus lopezi (Hymenoptera) in 2010, mealybug outbreaks were reduced, cropping area contracted and associated deforestation slowed by 31-94% in individual countries. When used with due caution and according to current guidelines, biological control offers broad benefits for people and the environment.
Forecasting the global extent of invasion of the cereal pest Spodoptera frugiperda, the fall armyworm
Authors: Early Regan , González-Moreno Pablo , Murphy Sean T. , Day Roger
Published: August 2018

Fall armyworm, Spodoptera frugiperda, is a crop pest native to the Americas, which has invaded and spread throughout sub-Saharan Africa within two years. Recent estimates of 20-50% maize yield loss in Africa suggest severe damage to livelihoods. Fall armyworm is still infilling its potential range in Africa, and could spread to other continents. In order to understand fall armyworm’s year-round, global, potential distribution, we used evidence of the effects of temperature and precipitation on fall armyworm life-history, combined with data on native and African distributions to construct Species Distribution Models (SDMs). Fall armyworm has only invaded areas that have a climate similar to the native distribution, validating the use of climatic SDMs. The strongest climatic limits on fall armyworm’s year-round distribution are the coldest annual temperature and the amount of rain in the wet season. Much of sub-Saharan Africa can host year-round fall armyworm populations, but the likelihoods of colonising North Africa and seasonal migrations into Europe are hard to predict. South and Southeast Asia and Australia have climate that would permit fall armyworm to invade. Current trade and transportation routes reveal Australia, China, India, Indonesia, Malaysia, Philippines, and Thailand face high threat of fall armyworm invasions originating from Africa.
Eye movements during text reading align with the rate of speech production
Authors: Gagl Benjamin , Gregorova Klara , Golch Julius , Hawelka Stefan , Sassenhagen Jona , Tavano Alessandro , Poeppel David , Fiebach Christian J.
Published: August 2018

Across languages, the speech signal is characterized by a predominant modulation of the amplitude spectrum between about 4.3-5.5Hz, reflecting the production and processing of linguistic information chunks (syllables, words) every ∼200ms. Interestingly, ∼200ms is also the typical duration of eye fixations during reading. Prompted by this observation, we demonstrate that German readers sample written text at ∼5Hz. A subsequent meta-analysis with 142 studies from 14 languages replicates this result, but also shows that sampling frequencies vary across languages between 3.9Hz and 5.2Hz, and that this variation systematically depends on the complexity of the writing systems (character-based vs. alphabetic systems, orthographic transparency). Finally, we demonstrate empirically a positive correlation between speech spectrum and eye-movement sampling in low-skilled readers. Based on this convergent evidence, we propose that during reading, our brain’s linguistic processing systems imprint a preferred processing rate, i.e., the rate of spoken language production and perception, onto the oculomotor system.
MeCP2-E1 isoform is a dynamically expressed, weakly DNA-bound protein with different protein and DNA interactions compared to MeCP2-E2
Authors: de Paz Alexia Martínez , Khajavi Leila , Martin Hélène , Claveria-Gimeno Rafael , Dieck Susanne tom , Cheema Manjinder S. , Sanchez-Mut Jose V. , Moksa Malgorzata M. , Carles Annaick , Brodie Nick I. , Sheikh Taimoor I. , Freeman Melissa E. , Petrotchenko Evgeniy V. , Borchers Christoph H. , Schuman Erin M. , Zytnicki Matthias , Velazquez-Campoy Adrian , Abian Olga , Hirst Martin , Esteller Manel , Vincent John B. , Malnou Cécile E. , Ausió Juan
Published: August 2018

MeCP2 – a chromatin-binding protein associated with Rett syndrome – has two main isoforms, MeCP2-E1 and MeCP2-E2, with 96% amino acid identity differing in a few N-terminal amino acid residues. Previous studies have shown brain region-specific expression of these isoforms which, in addition to their different cellular localization and differential expression during brain development, suggest they may also have non-overlapping molecular mechanisms. However, differential functions of MeCP2-E1 and E2 remain largely unexplored. Here, we show that the N-terminal domains (NTD) of MeCP2-E1 and E2 modulate the ability of the methyl binding domain (MBD) to interact with DNA as well as influencing the turnover rates, binding dynamics, response to nuclear depolarization, and circadian oscillations of the two isoforms. Our proteomics data indicate that both isoforms exhibit unique interacting protein partners. Moreover, genome-wide analysis using ChIP-seq provide evidence for a shared as well as a specific regulation of different sets of genes. Our findings provide insight into the functional complexity of MeCP2 by dissecting differential aspects of its two isoforms.

Significance

Whether the two E1 and E2 isoforms of MeCP2 have different structural and/or functional implications has been highly controversial and is not well known. Here we show that the relatively short N-terminal sequence variation between the two isoforms impinges them with an important DNA binding difference. Moreover, MeCP2-E1 and E2 exhibit a different cellular dynamic behavior and have some distinctive interacting partners. In addition, while sharing genome occupancy they specifically bind to several distinctive genes.
Filter paper-based spin column for low throughput nucleic acid purification
Authors: Shi Rui , Lewis Ramsey S. , Panthee Dilip R.
Published: August 2018

We describe a method of recharging used spin column or assembling homemade spin column using filter paper as binding material for low throughput nucleic acid purification. We evaluated the efficiency of filter paper based spin columns in the purification of different type of nucleic acids. For instance, by following protocols of respective commercial kits, we found that filter paper to be a useful binding material for purification of many types of nucleic acids, including plant genomic DNA, plant total RNA, PCR product, and DNA from agarose gels. We also found that filter paper has a weak binding affinity to plasmid DNA in tested miniprep protocols. Also, we present the protocols of using filter paper recharged spin column or homemade spin column for low throughput purification of plant genomic DNA and plant total RNA with commercial kit buffer leftover and less expensive homemade buffer.
MicroRNAs are likely part of the molecular toolkit regulating adult reproductive diapause in the mosquito, Culex pipiens
Authors: Meuti Megan E. , Bautista Robin , Reynolds Julie A.
Published: August 2018

For many arthropods, including insects, diapause is the primary mechanism for survival during unfavorable seasons. Although the exogenous signals and endogenous hormones that induce and regulate diapause are well-characterized, we still lack a mechanistic understanding of how environmental information is translated into molecular regulators of the diapause pathway. However, short, non-coding microRNAs (miRNAs) are likely involved in generating both the arrested egg follicle development and fat hypertrophy in diapausing females of the Northern house mosquito, Culex pipiens. To determine whether miRNAs might respond to changes in day length and/or regulate diapause pathways, we measured the abundance of candidate miRNAs in diapausing and nondiapausing females of Cx. pipiens across the adult lifespan. Of the selected miRNAs nearly all were more abundant in nondiapausing females relative to diapausing females, but at different times. Specifically, miR-13b-3p, miR-14-3p, miR-277-3p, and miR-305-5p were upregulated in nondiapausing females early in adulthood, while miR-309-3p and miR-375-3p were upregulated later in adult life, and miR-8-3p and miR-275-3p were upregulated both early and late in adult life. Taken together, our data demonstrate that miRNA expression is dynamic, changing across adult lifespan. Further, differential miRNA expression between diapausing and nondiapausing females of Cx. pipiens suggests that this epigenetic mechanism is part of the molecular toolkit regulating diapause.
Plasticity in striatal dopamine release is governed by release-independent depression and the dopamine transporter
Authors: Condon Mark D. , Platt Nicola J. , Zhang Yan-Feng , Roberts Bradley M. , Clements Michael A. , Vietti-Michelina Stefania , Tseu Min-Yee , Brimblecombe Katherine R. , Threlfell Sarah , Mann Ed O. , Cragg Stephanie J.
Published: August 2018

Mesostriatal DA neurons possess extensively branched axonal arbours. Whether action potentials are converted to DA output in striatum will be influenced dynamically and critically by axonal properties and mechanisms that are poorly understood. We addressed the roles for mechanisms governing release probability and axonal activity in determining short-term plasticity of DA release, using fast-scan cyclic voltammetry inex vivomouse striatum. Brief short-term facilitation (STF) and longer short-term depression (STD) were only weakly dependent on the level of initial release, i.e. were release-insensitive. Rather, short-term plasticity was strongly determined by mechanisms which governed axonal activation, including K+-gated excitability and the dopamine transporter (DAT), particularly in dorsal striatum. We identify the DAT as a master regulator of DA short-term plasticity, governing the balance between release-dependent and independent mechanisms that also show region-specific gating.

Key Findings

Short-term plasticity in dopamine release is only weakly governed by initial release

Short-term depression is strongly dependent on axonal excitability and activation

The dopamine transporter controls short-term plasticity and drives short-term depression

Dopamine transporters govern the balance between release-dependent and -independent mechanisms
New topology of direct current claw-pole machines for stop-start application
Authors: Bazhar Sara , Ristagno Baptiste , Fontchastagner Julien , Takorabet Noureddine , Labbe Nicolas
Published: August 2018

Purpose

This paper aims to propose a new topology of direct current (DC) machine using claw-pole stator to replace standard DC starter in micro-hybrid vehicles. The main interest of such a topology is the reduction of copper volume.

Design/methodology/approach

The design of the claw-pole machine is based on a multi-objective optimization of several topologies, based on a three-dimensional (3D) reluctance network modeling. The 3D finite element (FE) model is used to check the results of the optimization, and a prototype is manufactured and tested with satisfactory results.

Findings

The claw-pole topology with wave-shape windings allows to replace the current DC series classical starter because of to its copper volume saving.

Research limitations/implications

This model is only limited to the optimization of the claw-pole stator for a fixed geometry of the rotor.

Practical implications

The research outcome shows that claw-pole machine can replace the series-excited DC machines of starters and at the same time achieve the same performance at reduced copper volume.

Originality/value

The paper deals with a new DC machine topology to reduce the copper volume through the suppression of the classical stator end-windings. The use of Claw-Pole inductors ensures this copper reduction.