bluuebunny/crossref_metadata_2025 huggingface dataset:
Expansión urbana y turismo en la Comarca del Campo de Cartagena-Mar Menor (Murcia). Impacto en el sellado del suelo
Authors: Romero Díaz Asunción , Caballero Pedraza Agustín , Pérez Morales Alfredo
Published: July 2017

En las últimas décadas, la comarca estudiada ha experimentado una expansión urbana sin precedentes motivada por el turismo residencial. Esto ha supuesto un notable impacto medioambiental. Para estudiar este fenómeno y sus impactos, se han analizado los tipos de viviendas y población, digitalizando las superficies urbanas de tres fechas (1956, 1981 y 2011) y estimado la longitud y superficie de la red viaria. La superficie de suelo sellada, por este tipo de usos se ha evaluado en un 16% con respecto al total. Consecuencia de lo anterior es el aumento en la frecuencia de las inundaciones.
Discussion à visée philosophique et résilience : déontologie, pratique de l’enseignant et style d’animation dans la conduite de discussions philosophiques à visée résiliente1
Authors: Henrion-Latché Johanna , Tozzi Michel
Published: July 2017

La discussion à visée philosophique à l’école avec des enfants et des adolescents est une pratique qui permet de se saisir de la démarche philosophique afin de développer différentes modalités de pensée (critique, dialogique). Cette pratique novatrice se pose comme unepraxisdont les objectifs terminaux divergent selon un diagnostic des besoins fondamentaux de penser des élèves, depuis la méthode jusqu’aux dispositifs et contenus de pensée. Il appartient alors à l’enseignant de définir les modalités de mise en oeuvre de ses séances et de l’orientation de sa posture, afin de converger vers son objectif terminal, qui est celui d’établir un lien dialogique avec l’élève non-pensant et non communicant. Auprès d’adolescents manifestant des troubles du comportement et un refus de l’autorité, inadaptés aux institutions, et face au constat de souffrance de ces lycéens en échec social et scolaire, il est possible de s’appuyer sur les théories de la résilience à l’école pour incorporer, dans des séances comportant de la médiation, des facteurs conduisant au processus de résilience, qui relance les bases du processus de pensée sous une guidance spécifique de l’enseignant. Selon les recherches de Tozzi (2001,2004, 2006, 2007, 2012) sur le rôle du maître dans les discussions à visée philosophique, cet article expose une recherche sur la nécessité de conduire des adolescents déviants à penser par eux-mêmes, selon le processus émancipateur de la résilience.
Comparaison de deux stratégies pédagogiques dans l’apprentissage du toucher thérapeutique
Authors: Choplin Arnaud , Laporte Julie
Published: July 2017

L’objectif de cet article est de montrer que la performance pédagogique est à l’origine de modifications des pratiques professionnelles massothérapiques dans la prise en charge de la douleur fibromyalgique. Deux méthodologies quantitatives retracent le versant pédagogique. D’une part, un questionnaire montre de façon statistiquement significatif une déficience d’habiletés lors du démarrage palpatoire et lors de la palpation d’un élément précis et profond ; d’autre part, une étude expérimentale montre qu’une pédagogie par imitation modélisation-interactive est plus performante qu’un apprentissage behavioriste sur l’appropriation d’habiletés palpatoires. Un tel résultat est significatif (p < 1 %) dans l’acquisition de cinq habiletés sur six, et ce, indépendamment du genre et des connaissances théoriques anatomiques préalables. En conclusion, cette pédagogique est contributive à la performance d’un massage, base du traitement non médicamenteux de la douleur chronique de patients fibromyalgiques.
The Estrangement of Youth and the Quest for a different Society
Authors: Ferrarotti Franco
Published: July 2017

The author contends that any contestation or countercultural movement, no matter how generous, is bound to failure unless it develops as a rational project. Violence, as such, might help visibility, but, in the last analysis, it amounts to nothing more than self-gratifying narcissism, incapable to produce positive results, even less to satisfy the request of present day youth for a different, more open society.
The Role of Interreligious and Interfaith Dialogue in the Post-Secular World
Authors: Popovska Biljana , Ristoska Zhanet , Payet Pablo
Published: July 2017

Today, western liberal democratic societies are secular, or in other words, religion is set apart from the state. However, the beginning of the 21st century has seen a re-politicizing of the religion. This paper argues that religion plays an important role in current global politics and events. Moreover, it has been used as tool to recruit masses for a wrong cause. Hence, Interreligious and interfaith dialog can play a role of catalysts and a future trend in cultural diplomacy. The paper provides definitions of a secular and post secular society. Then, it discusses the general concept of dialogue and explores it from an interreligious and interfaith point of view as a way to mitigate the role religion has undertaken. Finally, it provides examples of what European Union has been doing in that respect.
State, Nation, and Sociology
Authors: Cipriani Roberto
Published: July 2017

The sociological science must be employed in the amelioration of society. The intellectual climate of a nation is a determinant feature for the success of sociology. Actually, there are areas in which the frame seems more favourable. The establishment of new electronic journals, regional and national associations and sociological societies reflects the expanding range of interests and professional specialization.
Gaming mirrors at play through ludic data-selves
Authors: Gandolfi Enrico
Published: July 2017

The focus of the article is on data-self technology in digital entertainment - virtual entities that replicate and/or are influenced by players’ behaviors and actions, working as agential mirrors on the screen. Little efforts have been done in investigating their potential in social research and educational technology; however, data-selves can serve as promising self-revealing tools toward personal identities and narrations. In order to enlighten their effectiveness, a multidisciplinary framework led by the core concepts of “narrative identity” and “discursive-practical consciousness” is advanced. The proposal has been tested (pre-post interviews and play sessions) with an empirical exploration involving n:32 participants and the video games Black and White 2 and Forza: Motorsprint 5, which include data-self features. Results show that this technology can make a difference in engaging and stimulating subjects’ interest and feedback, but further researches are needed to deepen its scope and range of application.
Pragmatism and Evolutionary Epistemology
Authors: Marsonet Michele
Published: July 2017

To understand the significance of a pragmatist stance in this matter we must address a basic question: which kind of evolution are we referring to when talking of “evolutionary epistemology”? If we take evolution to be an undifferentiated concept, such that no useful distinction can be found in it, we are on a wrong track. The evolutionary “pattern” is certainly one, but this should not lead us to assume that the specific characteristics of mankind must be left out of the picture, either because they are not important or because no specifically human characteristic is admitted. Nicholas Rescher’s evolutionary framework, for example, is instead pluralistic and multi-sided. It is worth noting how and why Rescher’s evolutionary epistemology differs from the one delineated in a famous book by Karl Popper. The Austrian-born philosopher based his approach on the “random conjectures and refutation” model. A scientist, for example, faces the problem of explaining nature’s doings by one of the endlessly many hypotheses that he has at his disposal. Subsequently he chooses to endorse a conjecture from this infinite range, and the testing itself, via falsification, furnishes the necessary selection. According to Popper’s picture we have, in sum, a sort of blind and random mechanism: his “trial-and-error” search procedure. Rescher’s opinion about this issue is that, on such Popperian grounds, scientific progress becomes more or less inexplicable. In particular, the success in providing explanatory theories that perform well in prediction and the guidance of applications in a complex world is now an accident of virtually miracolous proportions.
Spatiotemporal regulation of autophagy during Caenorhabditis elegans aging
Authors: Chang Jessica T , Kumsta Caroline , Hellman Andrew B , Adams Linnea M , Hansen Malene
Published: July 2017

Autophagy has been linked to longevity in many species, but the underlying mechanisms are unclear. Using a GFP-tagged and a new tandem-tagged Atg8/LGG-1 reporter, we quantified autophagic vesicles and performed autophagic flux assays in multiple tissues of wild-type Caenorhabditis elegans and long-lived daf-2/insulin/IGF-1 and glp-1/Notch mutants throughout adulthood. Our data are consistent with an age-related decline in autophagic activity in the intestine, body-wall muscle, pharynx, and neurons of wild-type animals. In contrast, daf-2 and glp-1 mutants displayed unique age- and tissue-specific changes in autophagic activity, indicating that the two longevity paradigms have distinct effects on autophagy during aging. Although autophagy appeared active in the intestine of both long-lived mutants, inhibition of intestinal autophagy significantly abrogated lifespan extension only in glp-1 mutants. Collectively, our data suggest that autophagic activity normally decreases with age in C. elegans, whereas daf-2 and glp-1 long-lived mutants regulate autophagy in distinct spatiotemporal-specific manners to extend lifespan.
Longevity is impacted by growth hormone action during early postnatal period
Authors: Sun Liou Y , Fang Yimin , Patki Amit , Koopman Jacob JE , Allison David B , Hill Cristal M , Masternak Michal M , Darcy Justin , Wang Jian , McFadden Samuel , Bartke Andrzej
Published: July 2017

Life-long lack of growth hormone (GH) action can produce remarkable extension of longevity in mice. Here we report that GH treatment limited to a few weeks during development influences the lifespan of long-lived Ames dwarf and normal littermate control mice in a genotype and sex-specific manner. Studies in a separate cohort of Ames dwarf mice show that this short period of the GH exposure during early development produces persistent phenotypic, metabolic and molecular changes that are evident in late adult life. These effects may represent mechanisms responsible for reduced longevity of dwarf mice exposed to GH treatment early in life. Our data suggest that developmental programming of aging importantly contributes to (and perhaps explains) the well documented developmental origins of adult disease.
An intersectional gene regulatory strategy defines subclass diversity of C. elegans motor neurons
Authors: Kratsios Paschalis , Kerk Sze Yen , Catela Catarina , Liang Joseph , Vidal Berta , Bayer Emily A , Feng Weidong , De La Cruz Estanisla Daniel , Croci Laura , Consalez G Giacomo , Mizumoto Kota , Hobert Oliver
Published: July 2017

A core principle of nervous system organization is the diversification of neuron classes into subclasses that share large sets of features but differ in select traits. We describe here a molecular mechanism necessary for motor neurons to acquire subclass-specific traits in the nematode Caenorhabditis elegans. Cholinergic motor neuron classes of the ventral nerve cord can be subdivided into subclasses along the anterior-posterior (A-P) axis based on synaptic connectivity patterns and molecular features. The conserved COE-type terminal selector UNC-3 not only controls the expression of traits shared by all members of a neuron class, but is also required for subclass-specific traits expressed along the A-P axis. UNC-3, which is not regionally restricted, requires region-specific cofactors in the form of Hox proteins to co-activate subclass-specific effector genes in post-mitotic motor neurons. This intersectional gene regulatory principle for neuronal subclass diversification may be conserved from nematodes to mice.
‘The new but lonely voice against the authoritarianism’: humor and irony in Turkish political discourse after the Taksim Gezi Park Protests
Authors: Aksan Gunes Ekin
Published: July 2017

This study investigates the diffusion of a new political language based on humour and irony into Turkish politics. The Taksim Gezi Park Protests, in addition to introducing a new subject to Turkish politics, led to a new language that places humour at the centre. The Government’s neoliberal and authoritarian policies and tight control over traditional media shaped the resistance to be humoristic and indirect. People used alternative media to voice their dissent, mainly in the form of social media messages in addition to street performances, graffiti, videos and murals. This new wave of humour, which I prefer to call the “public square humour” emphasised creativity, improvisation and pluralism via the usage of traditional conversational humour mechanisms of the Turkish folk narratives. I investigate the effect of this new wave of humour on the professional politicians over the course of following years after the protests in an increasingly authoritarian political climate. I analyse the Twitter messages of four major party leaders and politicians who are active in Twitter, both qualitatively and quantitatively. With the methods of the discourse analysis I identify the political parties that embrace the new language of the political opposition. Finally, I conclude that Demirtas embraces the public square humour better and makes use of it to underline the transformation of HDP (People’s Democratic Party) from a defendant of ethnic politics to the representative of the new voice of Turkish political opposition.
Russian attitudes towards humour and laughter
Authors: Ivanova Alyona , Stefanenko Ekaterina , Enikolopov Sergey
Published: July 2017

Different phenomena related to humour and laughter, such as humour styles, gelotophobia, gelotophilia and katagelasticism, were investigated in a series of psychological studies in Russia. As far as the samples were rather heterogeneous in regard with age, gender, region of Russia, and included besides big cities also small towns and villages, the data allows to discuss not only psychological, but also a certain cultural perspective. It is concluded that self-defeating humour style plays an important role in the structure of Russian cultural attitude towards humour and laughter. The most adaptive affiliative humour style is highly connected with self-defeating and aggressive styles. Similar pattern was shown for humour and laughter perception: a fear of being laughed at paradoxically provokes active involvement into exchange of jokes. A comparison between the two Russian capitals and regional sample revealed more similarities of Moscow and Saint Petersburg with western data than with the regional Russian sample which is supposed to reflect more of traditional national character.
Amino acids suppress the expression of PAT1 on lysosomes via inducing the cleavage of a targeting signal
Authors: Ji Xin , Zhao Lingling , Luo Hongjie , Zhang Xiangxiang , Jin Yaping , Liu Wei
Published: July 2017

The lysosome‐associated transporter proton‐coupled amino acid transporter 1 (PAT1) promotes nutrient recycling through releasing luminal amino acids into the cytosol. Using HEK293 cells expressing an EGFP‐tagged PAT1 (EGFP‐PAT1) as a model, we identified a consensus tyrosine‐based targeting signal in the cytosolic N‐terminal region of PAT1, which facilitates its expression on the lysosome. Interestingly, this signal can be removed via protein cleavage in an amino acid‐sensitive manner. The cleavage is suppressed upon amino acid starvation and is induced by amino acid replenishment. However, amino acid deficiency does not suppress the cleavage of amino acid‐binding mutants of EGFP‐PAT1. Our data support a mechanism, whereby amino acid binding induces PAT1 cleavage to remove a targeting signal, thus suppressing the expression of PAT1 on the lysosome.
Birth, life, and demise of the Andean–syn‐collisional Gissar arc: Late Paleozoic tectono‐magmatic‐metamorphic evolution of the southwestern Tian Shan, Tajikistan
Authors: Worthington James R. , Kapp Paul , Minaev Vladislav , Chapman James B. , Mazdab Frank K. , Ducea Mihai N. , Oimahmadov Ilhomjon , Gadoev Mustafo
Published: July 2017

The amalgamation of the Central Asian Orogenic Belt in the southwestern Tian Shan in Tajikistan is represented by tectono‐magmatic‐metamorphic processes that accompanied late Paleozoic ocean closure and collision between the Karakum‐Tarim and Kazakh‐Kyrgyz terranes. Integrated U‐Pb geochronology, thermobarometry, pseudosection modeling, and Hf geochemistry constrain the timing and petro‐tectonic nature of these processes. The Gissar batholith and the Garm massif represent an eastward, along‐strike increase in paleodepth from upper‐batholith (~21–7 km) to arc‐root (~36–19 km) levels of the Andean–syn‐collisional Gissar arc, which developed from ~323–288 Ma in two stages: (i) Andean, I‐type granitoid magmatism from ~323–306 Ma due to northward subduction of the Gissar back‐arc ocean basin under the Gissar microcontinent, which was immediately followed by (ii) syn‐collisional, I‐S‐type granitoid magmatism in the Gissar batholith and the Garm massif from ~304–288 Ma due to northward subduction/underthrusting of Karakum marginal‐continental crust under the Gissar microcontinent. A rapid isotopic pull‐up from ~288–286 Ma signals the onset of juvenile, alkaline‐syenitic, post‐collisional magmatism by ~280 Ma, which was driven by delamination of the Gissar arclogite root and consequent convective asthenospheric upwelling. Whereas M–HT/LP prograde metamorphism in the Garm massif (650–750°C/6–7 kbar) from ~310–288 Ma was associated with subduction‐magma inundation and crustal thickening, HT/LP heating and decompression to peak‐metamorphic temperatures (~800–820°C/6–4 kbar) at ~288 ± 6 Ma was driven by the transmission of a post‐collisional, mantle‐derived heat wave through the Garm‐massif crust.
Quantifying the heterogeneity of the tectonic stress field using borehole data
Authors: Schoenball Martin , Davatzes Nicholas C.
Published: July 2017

The heterogeneity of the tectonic stress field is a fundamental property which influences earthquake dynamics and subsurface engineering. Self‐similar scaling of stress heterogeneities is frequently assumed to explain characteristics of earthquakes such as the magnitude‐frequency relation. However, observational evidence for such scaling of the stress field heterogeneity is scarce. We analyze the local stress orientations using image logs of two closely spaced boreholes in the Coso Geothermal Field with subvertical and deviated trajectories, respectively, each spanning about 2 km in depth. Both the mean and the standard deviation of stress orientation indicators (borehole breakouts, drilling‐induced fractures, and petal‐centerline fractures) determined from each borehole agree to the limit of the resolution of our method although measurements at specific depths may not. We find that the standard deviation in these boreholes strongly depends on the interval length analyzed, generally increasing up to a wellbore log length of about 600 m and constant for longer intervals. We find the same behavior in global data from the World Stress Map. This suggests that the standard deviation of stress indicators characterizes the heterogeneity of the tectonic stress field rather than the quality of the stress measurement. A large standard deviation of a stress measurement might be an expression of strong crustal heterogeneity rather than of an unreliable stress determination. Robust characterization of stress heterogeneity requires logs that sample stress indicators along a representative sample volume of at least 1 km.
Snowmelt onset hinders bromine monoxide heterogeneous recycling in the Arctic
Authors: Burd Justine A. , Peterson Peter K. , Nghiem Son V. , Perovich Don K. , Simpson William R.
Published: July 2017

Reactive bromine radicals (bromine atoms, Br, and bromine monoxide, BrO) deplete ozone and alter tropospheric oxidation chemistry during the Arctic springtime (February–June). As spring transitions to summer (May–June) and snow begins to melt, reactive bromine events cease and BrO becomes low in summer. In this study, we explore the relationship between the end of the reactive bromine season and snowmelt timing. BrO was measured by Multi‐AXis Differential Optical Absorption Spectrometer at Utqiaġvik (Barrow), AK, from 2012 to 2016 and on drifting buoys deployed in Arctic sea ice from 2011 to 2016, a total of 13 site and year combinations. The BrO seasonal end date (SED) was objectively determined and was compared to surface‐air‐temperature‐derived melt onset date (MOD). The SED was highly correlated with the MOD (N = 13, R2 = 0.983, RMS = 1.9 days), and BrO is only observed at subfreezing temperatures. In subsets of these sites and years where ancillary data were available, we observed that snowpack depth reduced and rain precipitation occurred within a few days of the SED. These data are consistent with snowpack melting hindering BrO recycling, which is necessary to maintain enhanced BrO concentrations. With a projected warmer Arctic, a shift to earlier snowmelt seasons could alter the timing and role of halogen chemical reactions in the Arctic with impacts on ozone depletion and mercury deposition.
Arctic sea ice response to the eruptions of Agung, El Chichón, and Pinatubo
Authors: Gagné M.‐È. , Kirchmeier‐Young M. C. , Gillett N. P. , Fyfe J. C.
Published: July 2017

Using a large initial condition ensemble of climate model simulations, we examine the impact of volcanic activity on Arctic sea ice cover from 1960 to 2005, a period that includes three very large tropical eruptions. Ensemble averaging across simulations with natural (volcanic and solar) forcings alone reduces noise due to internal variability to show a decade of increased Arctic sea extent (of up to half a million square kilometers) following each of the Mount Agung (1963), Mount El Chichón (1982), and Mount Pinatubo (1991) eruptions. A similar impact is seen when averaging over a large ensemble of simulations with natural and all‐known anthropogenic forcings. We show that the volcanic response in sea ice cover is sensitive to preeruption temperature, with warmer conditions before an eruption being associated with a larger than average response. Finally, a detection and attribution analysis using second‐generation Canadian Earth System Model (CanESM2) did not identify a significant response in the observations, while finding no evidence of inconsistency between observations and CanESM2 since regression coefficients were consistent with unity. A similar detection and attribution analysis using the somewhat stronger volcanic response from the simulations in the average of the CMIP5 models did identify a detectable natural forcing response in four observational sea ice extent data sets.
Imaging Bacterial Colonies and Phage–Bacterium Interaction at Sub‐Nanometer Resolution Using Helium‐Ion Microscopy
Authors: Leppänen Miika , Sundberg Lotta‐Riina , Laanto Elina , de Freitas Almeida Gabriel Magno , Papponen Petri , Maasilta Ilari J.
Published: July 2017

Imaging of microbial interactions has so far been based on well‐established electron microscopy methods. This study presents a new way to study bacterial colonies and interactions between bacteria and their viruses, bacteriophages (phages), in situ on agar plates using helium ion microscopy (HIM). In biological imaging, HIM has advantages over traditional scanning electron microscopy with its sub‐nanometer resolution, increased surface sensitivity, and the possibility to image nonconductive samples. Furthermore, by controlling the He beam dose or by using heavier Ne ions, the HIM instrument provides the possibility to mill out material in the samples, allowing for subsurface imaging and in situ sectioning. Here, the first HIM‐images of bacterial colonies and phage–bacterium interactions are presented at different stages of the infection as they occur on an agar culture. The feasibility of neon and helium milling is also demonstrated to reveal the subsurface structures of bacterial colonies on agar substrate, and in some cases also structure inside individual bacteria after cross‐sectioning. The study concludes that HIM offers great opportunities to advance the studies of microbial imaging, in particular in the area of interaction of viruses with cells.
Application of X‐Ray Microtomography to Evaluate Complex Microstructure and Predict the Lower Bound Fatigue Potential of Cast Al–7(0.7)Si–4Cu–3Ni–Mg Alloys
Authors: Mbuya Thomas O. , Sinclair Ian , Soady Katherine A. , Reed Philippa A. S.
Published: July 2017

The 3D architecture of intermetallics and porosity in two multicomponent cast Al–7(0.7)Si–4Cu–3Ni–Mg alloys is characterized using conventional microscopy and X‐ray microtomography. The two alloys are found to contain intermetallic phases such as Al3Ni, Al3(NiCu)2, Al9FeNi, and Al5Cu2Mg8Si6 that have complex networked morphology in 3D. The results also show that HIPping does not significantly affect the volume fraction, size, and shape distribution of the intermetallic phases in both alloys. A novel technique similar to serial sectioning that circumvents quantification difficulties associated with interconnected particles is used to quantify the intermetallics. The largest particle size distribution is then correlated to fatigue performance using extreme value analysis to predict the maximum particle size in a sample of S‐N fatigue specimens and subsequently, the lower bound fatigue life. The predictions are found to correlate well with fatigue data. The effect of HIPping on porosity characteristics is also characterized. Large pore clusters with complex morphology are observed in the unHIPped versions of both alloys, but more significant in the low Si (Al–0.7Si–4Cu–3Ni–Mg) alloy. However, these are significantly reduced after HIPping. The differences between 2D and 3D pore morphology and size distribution is discussed in terms of the appropriate pore size parameter for fatigue life prediction.
Rietveld Texture Analysis for Metals Having Hexagonal Close‐Packed Phase by Using Time‐of‐Flight Neutron Diffraction at iMATERIA
Authors: Onuki Yusuke , Hoshikawa Akinori , Nishino Soichiro , Sato Shigeo , Ishigaki Toru
Published: July 2017

Texture is an important property especially for metallic materials having hexagonal close‐packed crystal structure. In order to understand the overall property or change in the microstructure of materials, neutron diffraction is a powerful tool of investigation. In this study, we attempt to measure the textures of Ti­–6Al–­4V (mass%) alloy by using a time‐of‐flight neutron diffractometer, iMATERIA. The results indicate that the texture measurement for the hexagonal phase is possible with the same method as for cubic metals. The texture of cubic β phase, whose volume fraction is several percent, can simultaneously be determined together with the hexagonal α phase.
Microstructure Evolution and Ablation Mechanism of C/C and C/C‐SiC Composites Under a Hypersonic Flowing Propane Torch
Authors: Jin Xiaochao , Fan Xueling , Jiang Peng , Wang Qiang
Published: July 2017

The high‐velocity oxygen fuel thermal spray system can provide a hypersonic flowing environment in which the temperature, pressure, and speed are all sufficiently high to represent a more realistic environment of hypersonic vehicles than that produced by traditional oxyacetylene flame. In this work, the ablation resistance of C/C and C/C‐SiC composites under hypersonic flowing propane flame is investigated, and the microstructure evolution during the ablation process is examined. It is found that different ablation regions are formed depending on the size, and the distributions of temperature and pressure on the front surface of the samples. With the increase of ablation time, a dense and continuous oxide layer forms, which acts as a barrier to prevent the interaction of oxidizing gases and composites, and can also block the conducted heat and resist high temperature scouring of hypersonic flowing flame. In addition, a numerical analysis is performed using ANSYS Fluent software to investigate the fields of velocity, pressure, and temperature on the front surface and around the carbon fibers of the sample. The simulation results further demonstrate the evolution of microstructures of C/C and C/C‐SiC composites.
Surface Functionalization of Micro/Nanostructured Titanium with Bioactive Ions to Regulate the Behaviors of Murine Osteoblasts
Authors: Wang Guisen , Wan Yi , Ren Bing , Wang Teng , Liu Zhanqiang
Published: July 2017

Surface topography and chemical composition are centrally important in current implants for enhancing cellular responses. To investigate the synergistic effect of micro/nanostructure and bioactive ions on the spreading, proliferation, and differentiation of murine osteoblasts, the micro/nanostructured titanium surface containing bioactive ions (Zn2+and Sr2+) was fabricated via sandblasting, acid etching, alkali‐heat treatment, and ion exchange. Compared to polished titanium substrates, micro/nanostructured titanium substrates displayed the enhanced roughness and hydrophilicity. And surface functionalization of micro/nanostructured using Zn2+/Sr2+ions exhibited the sustained release for a period of time. Meanwhile, cell experiments indicated that the Zn/Sr loaded micro/nanostructured titanium surfaces had a great potential to promote cell spreading, proliferation, and differentiation. This study provides a more promising method to design the surface of titanium implants for enhancing osseointegration.
3D Printing of Free‐Standing Stretchable Electrodes with Tunable Structure and Stretchability
Authors: Wei Hong , Li Kai , Liu Wen Guang , Meng Hong , Zhang Pei Xin , Yan Chao Yi
Published: July 2017

Free‐standing stretchable electrodes with high stretchability and resistance stability are desired for future wearable electronic applications. However, it is very difficult to achieve high stretchability (typically restricted by the substrate) and meanwhile maintain low resistance change upon stretching. Innovative designs and fabrication strategies need to be developed to meet the required characteristics. We report the successful fabrication of free‐standing wavy elastic electrodes achieving very high stretchability (>300% for PDMS) and outstanding resistance stability (only 5% relative resistance change at 100% strain), simultaneously. We systematically studied designs with different joining angles and shapes to optimize the electrode performances. The 3D free‐standing electrodes with outstanding stretchability and electrical stability has great potential for further optimizations and applications in future stretchable and wearable electronic devices.
Open‐Porous Silicon Nitride‐Based Ceramics in Tubular Geometry Obtained by Slip‐Casting and Gelcasting
Authors: Brouczek Dominik , Konegger Thomas
Published: July 2017

Owing to its unique properties, silicon nitride is a frequently used materials choice in highly demanding applications in terms of thermal and mechanical load. In this work, porous silicon nitride‐based support materials in hollow‐tube configuration are generated through colloidal forming, and their respective properties for potential applications in the fields of membrane‐based separation, filtration, or catalysis are evaluated. Shaping of the ceramics is achieved by two distinct casting techniques, slip‐casting, and gelcasting, and the results of the respective methods are set in relation. Furthermore, a special focus is set on the correlation between sintering parameters and resulting porosity. Subsequently, air permeabilities of the generated structures are determined, illustrating a direct relation between processing parameters and resulting permeability. Darcian permeability values of up to 9 · 10−16 m2 are observed for samples exhibiting total porosities between 32 and 41 %. The findings allow for a predictability of suitable permeation properties for the structures’ anticipated application as complex‐shaped non‐oxide ceramic supports for membrane‐based separation or catalysis, or as high‐performance filter materials.
Robust Red Organic Nanoparticles for In Vivo Fluorescence Imaging of Cancer Cell Progression in Xenografted Zebrafish
Authors: Lin Gengwei , Manghnani Purnima Naresh , Mao Duo , Teh Cathleen , Li Yinghao , Zhao Zujin , Liu Bin , Tang Ben Zhong
Published: July 2017

Bright and red‐emissive organic nanoparticles (NPs) are demonstrated as promising for in vivo fluorescence imaging. However, most red organic dyes show greatly weakened or quenched emission in the aggregated state. In this work, a robust red fluorophore (t‐BPITBT‐TPE) with strong aggregate‐state photoluminescence and good biocompatibility is presented. The NPs comprised of t‐BPITBT‐TPE aggregates encapsulated within 1,2‐distearoyl‐sn‐glycero‐3‐phosphoethanolamine‐N‐[methoxy(polyethylene glycol) (DSPE‐mPEG) micelles exhibit a photoluminescence peak at 660 nm with a high fluorescence quantum yield of 32% in aqueous media. The NPs can be facilely charged by using the same polymeric matrix with different terminal groups, e.g., methoxy (DSPE‐mPEG), amine (DSPE‐PEG‐NH2), or carboxymethyl (DSPE‐PEG‐COOH) groups. The biocompatibility, toxicity, circulation, and biodistribution of the NPs are assessed using the zebrafish model through whole embryo soaking and intravenous delivery. Furthermore, HeLa and MCF‐7 cells tagged with t‐BPITBT‐TPE in DSPE‐PEG‐NH2‐TAT polymer NPs are xenografted into zebrafish larvae to successfully track the cancer cell proliferation and metastasis, demonstrating that these new NPs are efficient cancer cell trackers. In addition, the NPs also show good in vivo imaging ability toward 4T1 tumors in xenografted BALB/c mice.
Synergistic Effect of Si Doping and Heat Treatments Enhances the Photoelectrochemical Water Oxidation Performance of TiO2 Nanorod Arrays
Authors: Chen Changlong , Wei Yuling , Yuan Guangzheng , Liu Qinglong , Lu Ranran , Huang Xing , Cao Yi , Zhu Peihua
Published: July 2017

TiO2 is a very promising photocatalytic material due to its merits including low cost, nontoxicity, high chemical stability, and photocorrosion resistance. However, it is also known that TiO2 is a wide bandgap material, and it is still challenging to achieve high photocatalytic performance driven by solar light. In this paper, silicon‐doped TiO2 nanorod arrays are vertically grown on fluorine‐doped tin oxide substrates and then are heat treated both in air and in vacuum. It is found that the silicon doping together with the heat treatment brings synergic effect to TiO2 nanorod films by increasing the crystallinity, producing abundant oxygen vacancies, enhancing the hydrophilicity as well as improving the electronic properties. When used as photoanodes in photoelectrochemical water splitting, under the condition of AM 1.5G simulated solar irradiation and without using any cocatalysts, these nanorod films show photocurrent density as high as 0.83 mA cm−2 at a potential of 1.23 V versus reversible hydrogen electrode, which is much higher than that of the TiO2 nanorod films without doping or heat treating. The silicon‐doped TiO2 nanorod array films described in this paper are envisioned to provide valuable platforms for supporting catalysts and cocatalysts for efficient solar‐light‐assisted water oxidation and other solar‐light‐driven photocatalytic applications.
Gold Nanoparticles and g‐C3N4‐Intercalated Graphene Oxide Membrane for Recyclable Surface Enhanced Raman Scattering
Authors: Qu Lulu , Wang Na , Xu Hui , Wang Weipeng , Liu Yang , Kuo Lidia , Yadav T. P. , Wu Jingjie , Joyner Jarin , Song Yanhua , Li Haitao , Lou Jun , Vajtai Robert , Ajayan Pulickel M.
Published: July 2017

Toxic organic pollutants in the aquatic environment cause severe threats to both humans and the global environment. Thus, the development of robust strategies for detection and removal of these organic pollutants is essential. For this purpose, a multifunctional and recyclable membrane by intercalating gold nanoparticles and graphitic carbon nitride into graphene oxide (GNPs/g‐C3N4/GO) is fabricated. The membranes exhibit not only superior surface enhanced Raman scattering (SERS) activity attributed to high preconcentration ability to analytes through π–π and electrostatic interactions, but also excellent catalytic activity due to the enhanced electron–hole separation efficiency. These outstanding properties allow the membrane to be used for highly sensitive detection of rhodamine 6G with a limit of detection of 5.0 × 10−14m and self‐cleaning by photocatalytic degradation of the adsorbed analytes into inorganic small molecules, thus achieving recyclable SERS application. Furthermore, the excellent SERS activity of the membrane is demonstrated by detection of 4‐chlorophenol at less than nanomolar level and no significant SERS or catalytic activity loss was observed when reusability is tested. These results suggest that the GNPs/g‐C3N4/GO membrane provides a new strategy for eliminating traditional, single‐use SERS substrates, and expands practical SERS application to simultaneous detection and removal of environmental pollutants.
An Overview of the Development of Flexible Sensors
Authors: Han Su‐Ting , Peng Haiyan , Sun Qijun , Venkatesh Shishir , Chung Kam‐Sing , Lau Siu Chuen , Zhou Ye , Roy V. A. L.
Published: July 2017

Flexible sensors that efficiently detect various stimuli relevant to specific environmental or biological species have been extensively studied due to their great potential for the Internet of Things and wearable electronics applications. The application of flexible and stretchable electronics to device‐engineering technologies has enabled the fabrication of slender, lightweight, stretchable, and foldable sensors. Here, recent studies on flexible sensors for biological analytes, ions, light, and pH are outlined. In addition, contemporary studies on device structure, materials, and fabrication methods for flexible sensors are discussed, and a market overview is provided. The conclusion presents challenges and perspectives in this field.
Tunneling Photocurrent Assisted by Interlayer Excitons in Staggered van der Waals Hetero‐Bilayers
Authors: Luong Dinh Hoa , Lee Hyun Seok , Neupane Guru Prakash , Roy Shrawan , Ghimire Ganesh , Lee Jin Hee , Vu Quoc An , Lee Young Hee
Published: July 2017

Vertically stacked van der Waals (vdW) heterostructures have been suggested as a robust platform for studying interfacial phenomena and related electric/optoelectronic devices. While the interlayer Coulomb interaction mediated by the vdW coupling has been extensively studied for carrier recombination processes in a diode transport, its correlation with the interlayer tunneling transport has not been elucidated. Here, a contrast is reported between tunneling and drift photocurrents tailored by the interlayer coupling strength in MoSe2/MoS2 hetero‐bilayers (HBs). The interfacial coupling modulated by thermal annealing is identified by the interlayer phonon coupling in Raman spectra and the emerging interlayer exciton peak in photoluminescence spectra. In strongly coupled HBs, positive photocurrents are observed owing to the inelastic band‐to‐band tunneling assisted by interlayer excitons that prevail over exciton recombinations. By contrast, weakly coupled HBs exhibit a negative photovoltaic diode behavior, manifested as a drift current without interlayer excitonic emissions. This study sheds light on tailoring the tunneling transport for numerous optoelectronic HB devices.
On the Relationship Between Donor/Acceptor Interface Energy Levels and Open‐Circuit Voltages
Authors: Li Peicheng , Hong Weiji , Li Yiying , Ingram Grayson , Lu Zheng‐Hong
Published: July 2017

Energy offset (EDA) from a number of donor/acceptor heterojunctions is measured using ultraviolet photoemission spectroscopy. It is found that substrate work functions have little impact on the energy level alignments at donor/acceptor heterojunctions. Planar‐heterojunction organic photovoltaic cells are made to test the relationship between energy offset and open‐circuit voltage (VOC). VOC is found to increase linearly as a function of EDA. The VOC, however, takes a surprising turn at EDA = 1.5 eV and starts to decrease as a function of donor–acceptor energy levels. To explain this experimental observation, a theoretical model to quantify the relationship between VOC and EDA is developed. The proposed model well explains the experimental data and, in particular, the reverse trend of VOC on EDA. By grouping several material constants into one variable, a simple universal plot that well describes the experimental data for both planar‐heterojunction and bulk‐heterojunction cells is generated.
Vertically Aligned Graphene Nanosheet Arrays: Synthesis, Properties and Applications in Electrochemical Energy Conversion and Storage
Authors: Zhang Zhenyu , Lee Chun‐Sing , Zhang Wenjun
Published: July 2017

In the pursuit of better electrode kinetics and mass transportation for electrochemical energy applications, 3D graphene‐based electrodes have been receiving increasing research interest. Distinguished from other kinds of 3D graphene structures, the well‐developed, vertically aligned graphene nanosheet arrays (VAGNAs) could be grown on a variety of substrates by plasma‐enhanced chemical vapor deposition (PECVD), forming a 3D interconnected structure with intimate contact with substrates and largely exposed edges, and easily accessible open surfaces of the graphene nanosheets. Ascribing to the combined superior inherent properties of graphene and the special structure configuration, e.g., large surface area, excellent electron transfer capability, outstanding mechanical strength, great chemical and thermal stabilities, and enhanced electrochemical activity, VAGNAs have demonstrated promising applications in supercapacitors, batteries, and fuel cell catalysts. This progress report provides a brief review on the nucleation and growth of VAGNAs, their growth mechanism and properties, and highlights the recent important progress in their electrochemical energy conversion and storage applications, in the views of their pros and cons in comparison with other 3D graphene‐based structures. Challenges and perspectives for future advance are discussed in the end.
Burn‐in Free Nonfullerene‐Based Organic Solar Cells
Authors: Gasparini Nicola , Salvador Michael , Strohm Sebastian , Heumueller Thomas , Levchuk Ievgen , Wadsworth Andrew , Bannock James H. , de Mello John C. , Egelhaaf Hans‐Joachim , Baran Derya , McCulloch Iain , Brabec Christoph J.
Published: July 2017

Organic solar cells that are free of burn‐in, the commonly observed rapid performance loss under light, are presented. The solar cells are based on poly(3‐hexylthiophene) (P3HT) with varying molecular weights and a nonfullerene acceptor (rhodanine‐benzothiadiazole‐coupled indacenodithiophene, IDTBR) and are fabricated in air. P3HT:IDTBR solar cells light‐soaked over the course of 2000 h lose about 5% of power conversion efficiency (PCE), in stark contrast to [6,6]‐Phenyl C61 butyric acid methyl ester (PCBM)‐based solar cells whose PCE shows a burn‐in that extends over several hundreds of hours and levels off at a loss of ≈34%. Replacing PCBM with IDTBR prevents short‐circuit current losses due to fullerene dimerization and inhibits disorder‐induced open‐circuit voltage losses, indicating a very robust device operation that is insensitive to defect states. Small losses in fill factor over time are proposed to originate from polymer or interface defects. Finally, the combination of enhanced efficiency and stability in P3HT:IDTBR increases the lifetime energy yield by more than a factor of 10 when compared with the same type of devices using a fullerene‐based acceptor instead.
The Critically Endangered western chimpanzee declines by 80%
Authors: Kühl Hjalmar S. , Sop Tenekwetche , Williamson Elizabeth A. , Mundry Roger , Brugière David , Campbell Genevieve , Cohen Heather , Danquah Emmanuel , Ginn Laura , Herbinger Ilka , Jones Sorrel , Junker Jessica , Kormos Rebecca , Kouakou Celestin Y. , N'Goran Paul K. , Normand Emma , Shutt‐Phillips Kathryn , Tickle Alexander , Vendras Elleni , Welsh Adam , Wessling Erin G. , Boesch Christophe
Published: July 2017

African large mammals are under extreme pressure from unsustainable hunting and habitat loss. Certain traits make large mammals particularly vulnerable. These include late age at first reproduction, long inter‐birth intervals, and low population density. Great apes are a prime example of such vulnerability, exhibiting all of these traits. Here we assess the rate of population change for the western chimpanzee,Pan troglodytes verus, over a 24‐year period. As a proxy for change in abundance, we used transect nest count data from 20 different sites archived in the IUCN SSC A.P.E.S. database, representing 25,000 of the estimated remaining 35,000 western chimpanzees. For each of the 20 sites, datasets for 2 different years were available. We estimated site‐specific and global population change using Generalized Linear Models. At 12 of these sites, we detected a significant negative trend. The estimated change in the subspecies abundance, as approximated by nest encounter rate, yielded a 6% annual decline and a total decline of 80.2% over the study period from 1990 to 2014. This also resulted in a reduced geographic range of 20% (657,600 vs. 524,100 km2). Poverty, civil conflict, disease pandemics, agriculture, extractive industries, infrastructure development, and lack of law enforcement, are some of the many reasons for the magnitude of threat. Our status update triggered the uplisting of the western chimpanzee to “Critically Endangered” on the IUCN Red List. In 2017, IUCN will start updating the 2003 Action Plan for western chimpanzees and will provide a consensus blueprint for what is needed to save this subspecies. We make a plea for greater commitment to conservation in West Africa across sectors. Needed especially is more robust engagement by national governments, integration of conservation priorities into the private sector and development planning across the region and sustained financial support from donors.