bluuebunny/crossref_metadata_2025 huggingface dataset:
Present and Future Mercury Concentrations in Chinese Rice: Insights From Modeling
Authors: Kwon S. Y. , Selin N. E. , Giang A. , Karplus V. J. , Zhang D.
Published: February 2018

We construct a rice paddy biogeochemical cycle model to investigate processes governing rice mercury sources and to understand factors influencing spatiotemporal variability in Chinese rice mercury concentrations. The rice paddy model takes atmospheric mercury deposition, simulated from a global atmospheric chemistry transport model (GEOS‐Chem), and soil and irrigable surface water mercury concentrations obtained from literature and calculates rice inorganic (IHg) and methylmercury (MeHg) concentrations. We use ranges of GEOS‐Chem‐simulated future atmospheric mercury deposition—no policy and strict policy to regulate mercury emissions from Chinese coal‐fired power plants under the Minamata Convention on Mercury—to simulate future rice IHg and MeHg concentrations. Sensitivity analyses suggest that rice IHg and MeHg concentrations are more sensitive to the process of soil desorption than infiltration of recently introduced mercury (atmospheric and irrigation source). The rate of internal methylation via microbial activity has the largest modeled influence on rice MeHg concentration. We find that soil mercury, rather than atmospheric deposition, explains observed spatial variability in rice IHg and MeHg concentrations and captures locations of rice mercury hot spots (>20 ng/g; China National Standard Limit). Under our future scenarios, the Chinese median rice IHg and MeHg concentration increases by 13% and decrease by 18% under no policy and strict policy, respectively. Regions with the largest percentage decline in rice IHg and MeHg concentrations under strict policy are in central China, which have high rice mercury concentrations, rice production, and consumption. Our study suggests that addressing Chinese rice mercury contamination requires attention to contaminated soil and regulation of anthropogenic mercury emissions.
Mixing of Felsic Magmas in Granite Petrogenesis: Geochemical Records of Zircon and Garnet in Peraluminous Granitoids From South China
Authors: Rong Wei , Zhang Shao‐Bing , Zheng Yong‐Fei , Gao Peng
Published: February 2018

Mixing of felsic magmas from different sources may be common in granite petrogenesis, but challenging to unravel. Nevertheless, this is identified by a combined study of in situ zircon and garnet geochemistry with whole‐rock geochemistry for the Jiuling batholith in South China. The Jiuling batholith is composed of low‐Si granitoids and high‐Si granites. Although they show similar whole‐rock Sr‐Nd‐Hf isotope compositions, the low‐Si granitoids exhibit higher MgO, FeO, TiO2, Al2O3, and Middle rare earth elements contents, and higher Zr saturation temperature than the high‐Si granites. Two groups of zircons and garnets are identified in the form of either individual grains or different domains of a grain. Although they exhibit highly variable O and Hf isotope compositions, Group I zircons show higher δ18O and lower εHf(t) values than Group II zircons. Group I garnets are higher in FeO and MgO but lower in CaO and MnO than Group II garnets. Group I garnets show more remarkable negative Eu anomalies than Group II garnets. Groups I and II garnets exhibit distinct δ18O values, in equilibrium with Groups I and II zircons, respectively. These differences indicate that the two groups of zircons and garnets were derived from two different batches of felsic magmas. Batch I magma may be derived from partial melting of ancient sedimentary rocks at higher temperature, whereas Batch II magma would probably form by partial melting of relatively juvenile crust at lower temperature. Therefore, the Jiuling batholith is produced by mixing between two batches of granitic magmas with different trace element and isotope compositions.
A Century of Stability of Avannarleq and Kujalleq Glaciers, West Greenland, Explained Using High‐Resolution Airborne Gravity and Other Data
Authors: An L. , Rignot E. , Mouginot J. , Millan R.
Published: February 2018

The evolution of Greenland glaciers in a warming climate depends on their depth below sea level, flow speed, surface melt, and ocean‐induced undercutting at the calving front. We present an innovative mapping of bed topography in the frontal regions of Sermeq Avannarleq and Kujalleq, two major glaciers flowing into the ice‐choked Torssukatak Fjord, central west Greenland. The mapping combines a mass conservation algorithm inland, multibeam echo sounding data in the fjord, and high‐resolution airborne gravity data at the ice‐ocean transition where other approaches have traditionally failed. We obtain a reliable, precision (±40 m) solution for bed topography across the ice‐ocean boundary. The results reveal a 700 m deep fjord that abruptly ends on a 100–300 m deep sill along the calving fronts. The shallow sills explain the presence of stranded icebergs, the resilience of the glaciers to ocean‐induced undercutting by warm Atlantic water, and their remarkable stability over the past century.
Cytoprotective activity of mitochondrial uncoupling protein‐2 in lung and spleen
Authors: Jabůrek Martin , Ježek Jan , Ježek Petr
Published: February 2018

Mitochondrial uncoupling protein‐2 (UCP2) mediates free fatty acid (FA)‐dependent H+ translocation across the inner mitochondrial membrane (IMM), which leads to acceleration of respiration and suppression of mitochondrial superoxide formation. Redox‐activated mitochondrial phospholipase A2 (mt‐iPLA2γ) cleaves FAs from the IMM and has been shown to acts in synergy with UCP2. Here, we tested the mechanism of mt‐iPLA2γ‐dependent UCP2‐mediated antioxidant protection using lipopolysaccharide (LPS)‐induced pro‐inflammatory and pro‐oxidative responses and their acute influence on the overall oxidative stress reflected by protein carbonylation in murine lung and spleen mitochondria and tissue homogenates. We provided challenges either by blocking the mt‐iPLA2γ function by the selective inhibitor R‐bromoenol lactone (R‐BEL) or by removing UCP2 by genetic ablation. We found that the basal levels of protein carbonyls in lung and spleen tissues and isolated mitochondria were higher in UCP2‐knockout mice relative to the wild‐type (wt) controls. The administration of R‐BEL increased protein carbonyl levels in wt but not in UCP2‐knockout (UCP2‐KO) mice. LPS further increased the protein carbonyl levels in UCP2‐KO mice, which correlated with protein carbonyl levels determined in wt mice treated with R‐BEL. These results are consistent with the UCP2/mt‐iPLA2γ antioxidant mechanisms in these tissues and support the existence of UCP2‐synergic mt‐iPLA2γ‐dependent cytoprotective mechanism in vivo.
Grooming
Authors: McFarland Richard
Published: February 2018

Grooming behavior is seen throughout the animal kingdom, but is particularly prevalent among the primates. Primate grooming is typically a bimanual process, whereby the groomer sweeps through the pelt with their hands, while removing dirt and ectoparasites from the skin or hair fibers with their hands or mouth. Grooming is thought to have evolved primarily for its hygienic function. The persistence of grooming in the absence of a hygienic demand, and its tactical importance to primate group members, however, supports the view that grooming also plays an important role in servicing social relationships and, in turn, can have a positive impact on an individual's reproductive fitness.
Isotope analysis
Authors: Schoeninger Margaret
Published: February 2018

Isotope data are used in reconstructing diet, paleodiet, ecology, paleoecology, climate, paleoclimate, aridity, pathology and health, migration assessments, and weaning and other life‐history patterns in humans and nonhuman primates, a large number of other animals, and their fossil precursors and relatives. Isotope analysis originated in physics and chemistry, and was quickly assimilated by biological anthropologists, bioarchaeologists, and archaeologists, who used carbon and nitrogen isotopes for diet reconstruction, oxygen isotopes for climate and paleoclimate, and strontium isotopes for migration studies. Isotope analysis now routinely informs in acculturation studies, status differences in diet, diet in health and disease, and the paleoecology of our fossil ancestors and relatives.
Taxonomy and classification: conceptual history
Authors: Cartmill Matt
Published: February 2018

The history of zoological classification has passed through three phases: (1) Linnaeanessentialist classification, in which animals are grouped on the basis of traits deemed essential to defining “natural” groups; (2)evolutionary classification, in which boundaries delimiting groups differing in adaptations are drawn on an evolutionary tree; and (3)phylogenetic classification, in which the classification simply maps the pattern of sequential phylogenetic divergences within the group being classified.
Surface Textures Fabricated by Laser Surface Texturing and Diamond Cutting – Influence of Texture Depth on Friction and Wear
Authors: Zhang Jun‐Jie , Zhang Jian‐Guo , Rosenkranz Andreas , Zhao Xiao‐Li , Song Ye‐Lin
Published: February 2018

In the present work, the authors study the tribological characteristics of textured stainless steel surfaces with different texture depths ranging from 1.3 to 23 µm created by laser surface texturing and ultra‐precision diamond cutting. The periodicity of the surface textures is kept constant at 90 µm for each fabrication technique and texture depth. Subsequent ball‐on‐disk friction tests show that friction and wear can be effectively reduced by the surface texturing. It is found that the effectiveness of the surface textures greatly depends on the depth and the geometry of the textures, as well as on testing parameters such as the applied load and the sliding velocity. Surface textures with the lowest depth demonstrate a slightly increased COF as well as an increased mass loss under low loads or sliding velocities. On the other hand, surface textures with intermediate depths show a significant reduction in the COF and wear. The observed friction and wear reduction can be mainly attributed to a combined effect of the surface textures consisting of the generation of an additional hydrodynamic pressure, the storage of produced wear particles as well as the action as secondary source for lubricant (reservoir effect).
Electrical Double‐Slope Nonideality in Organic Field‐Effect Transistors
Authors: Phan Hung , Ford Michael J. , Lill Alexander T. , Wang Ming , Bazan Guillermo C. , Nguyen Thuc‐Quyen
Published: February 2018

The field effect transistor (FET) is arguably one of the most important circuit elements in modern electronics. Recently, a need has developed for flexible electronics in a variety of emerging applications. Examples include form‐fitting healthcare‐monitoring devices, flexible displays, and flexible radio frequency identification tags. Organic FETs (OFETs) are viable candidates for producing such flexible devices because they incorporate semiconducting π‐conjugated materials, including small molecules and conjugated polymers, which are intrinsically soft and mechanically compatible with flexible substrates. For OFETs to be industrially viable, however, they must achieve not only high charge carrier mobility, but also ideal and comprehensible electrical characteristics. Most recently, nonideal double‐slope characteristics in the transfer curves of OFETs (i.e., high slope at low gate voltage and low slope at high gate voltage), have stirred debate, which has led to different mechanistic rationales in the literature. This review focuses on the general observations, mechanistic understanding, and possible solutions associated with phenomena that result in FETs with double‐slope characteristics. By surveying and systematically summarizing in a single source relevant literature that deals with the issue of double slope, the experimental framework and theoretical basis for interpreting and avoiding this electrical nonideality in OFETs is provided.
Facilitated Water Transport through Graphene Oxide Membranes Functionalized with Aquaporin‐Mimicking Peptides
Authors: Lee Chang Seon , Choi Moon‐ki , Hwang Ye Young , Kim Hyunki , Kim Moon Ki , Lee Yun Jung
Published: February 2018

Water purification by membranes is widely investigated to address concerns related to the scarcity of clean water. Achieving high flux and rejection simultaneously is a difficult challenge using such membranes because these properties are mutually exclusive in common artificial membranes. Nature has developed a method for this task involving water‐channel membrane proteins known as aquaporins. Here, the design and fabrication of graphene oxide (GO)‐based membranes with a surface‐tethered peptide motif designed to mimic the water‐selective filter of natural aquaporins is reported. The short RF8 (RFRFRFRF, where R and F represent arginine and phenylalanine, respectively) octapeptide is a concentrated form of the core component of the Ar/R (aromatic/arginine) water‐selective filter in aquaporin. The resulting GO‐RF8 shows superior flux and high rejection similar to natural aquaporins. Molecular dynamics simulation reveal the unique configuration of RF8 peptides and the transport of water in GO‐RF8 membranes, supporting that RF8 effectively emulates the core function of aquaporins.
Soft Somatosensitive Actuators via Embedded 3D Printing
Authors: Truby Ryan L. , Wehner Michael , Grosskopf Abigail K. , Vogt Daniel M. , Uzel Sebastien G. M. , Wood Robert J. , Lewis Jennifer A.
Published: February 2018

Humans possess manual dexterity, motor skills, and other physical abilities that rely on feedback provided by the somatosensory system. Herein, a method is reported for creating soft somatosensitive actuators (SSAs) via embedded 3D printing, which are innervated with multiple conductive features that simultaneously enable haptic, proprioceptive, and thermoceptive sensing. This novel manufacturing approach enables the seamless integration of multiple ionically conductive and fluidic features within elastomeric matrices to produce SSAs with the desired bioinspired sensing and actuation capabilities. Each printed sensor is composed of an ionically conductive gel that exhibits both long‐term stability and hysteresis‐free performance. As an exemplar, multiple SSAs are combined into a soft robotic gripper that provides proprioceptive and haptic feedback via embedded curvature, inflation, and contact sensors, including deep and fine touch contact sensors. The multimaterial manufacturing platform enables complex sensing motifs to be easily integrated into soft actuating systems, which is a necessary step toward closed‐loop feedback control of soft robots, machines, and haptic devices.
Synthesis, Application and Kinetic Studies of Chiral Phosphite‐Oxazoline Palladium Complexes as Active and Selective Catalysts in Intermolecular Heck Reactions
Authors: Mazloomi Zahra , Magre Marc , Del Valle Efrem , Pericàs Miquel A. , Pàmies Oscar , van Leeuwen Piet W. N. M. , Diéguez Montserrat
Published: February 2018

This study identifies new phosphite‐oxazoline ligands that have been successfully applied in the palladium‐catalyzed intermolecular asymmetric Heck reaction. The design of the new phosphite‐oxazoline ligands derives from a previous successful generation of phosphine‐oxazoline ligands, by replacing the phosphine group with several π‐acceptor biaryl phosphite moieties. With these simple modifications, the new phosphite‐based ligands, unlike previous phosphine‐oxazoline, not only present a modular design with numerous potential phosphite groups available, but they are also air‐stable solids, which can be made in the same number of synthetic steps as the phosphine analogues. The substitution of the phosphine by a biaryl phosphite group extended the range of substrates and triflates sources that can be coupled with regio‐, enantioselectivities and activities comparable to the few best ones reported. In addition, the ligands that provided the best selectivities contained an isopropyl oxazoline moiety instead of the tert‐butyl group found in the related phosphine‐oxazoline ligands, which is made from a much more expensive precursor. In this paper we have also carried out kinetic studies and a Hammett plot analysis to determine the rate determining step of this system in the regime of interest. We suggest a likely explanation for the fast Heck reaction of the phosphite‐oxazoline catalysts.

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Selective Synthesis of Primary Amines from Nitriles under Hydrogenation Conditions
Authors: Yoshimura Masatoshi , Komatsu Akira , Niimura Masaru , Takagi Yukio , Takahashi Tohru , Ueda Shun , Ichikawa Tomohiro , Kobayashi Yutaka , Okami Hiroki , Hattori Tomohiro , Sawama Yoshinari , Monguchi Yasunari , Sajiki Hironao
Published: February 2018

The hydrogenation of aliphatic nitriles over Pd/C, Pd/Al2O3, and Pd−Au/Al2O3 catalysts were evaluated for the selective hydrogenation of aliphatic nitriles to the corresponding primary amines. The highest selectivity (>99%) toward primary amines was achieved when the reaction was carried out in acetic acid using 10 mol% of 25% Pd‐5% Au/Al2O3 under relatively low hydrogen pressure (0.8 MPa). Characterization of the catalysts by XRD, CO adsorption experiments, and EXAFS revealed that the excellent selectivity of 25% Pd‐5% Au/Al2O3 toward the synthesis of primary amines is determined by the electronic properties and/or the surface structure resulting from alloying Pd with Au.

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Der präexponentielle Faktor in der Elektrochemie
Authors: He Zheng‐Da , Chen Yan‐Xia , Santos Elizabeth , Schmickler Wolfgang
Published: February 2018

Wie in vielen Zweigen der Wissenschaft, um nicht von der Kultur im Allgemeinen zu reden, so gibt es auch in der Elektrochemie eine Reihe von wiederkehrenden Themen: Forschungsgebiete, die eine Zeit lang populär sind, dann verblassen, wenn ihre Möglichkeiten erschöpft scheinen, um Jahrzehnte später wieder aktuell zu werden, wenn Fortschritte in experimentellen oder theoretischen Techniken neue Forschungsmöglichkeiten eröffnen. Ein gutes Beispiel sind Brennstoffzellen, die fünf solcher Zyklen durchlaufen haben; aber hier soll ein allgemeineres Konzept der Kinetik diskutiert werden, nämlich der präexponentielle Faktor einer Geschwindigkeitskonstanten, der bisher zwei solcher Zyklen durchlaufen hat. Der erste Zyklus umfasst etwa die Zeitspanne 1950 bis 1980, als die Methoden der elektrochemischen Kinetik entwickelt wurden und die Interpretationen auf der Theorie des Übergangszustands basierten. Der zweite wurde durch die Wiederentdeckung der Kramers‐Theorie für Reaktionen in kondensierten Phasen ausgelöst. Dieser Kurzaufsatz soll zeigen, dass es Zeit für einen dritten Zyklus ist, der auf neuen Ergebnissen in der Elektrokatalyse beruht.
Elektronentransfer um eine molekulare Ecke
Authors: Schmidt Hauke C. , Larsen Christopher B. , Wenger Oliver S.
Published: February 2018

Die Distanzabhängigkeit des intramolekularen Elektronentransfers (ET) wird typischerweise in linearen Modellverbindungen mit starrer Geometrie untersucht, wobei Studien über molekulare Kabel, die einen 90°‐Winkel aufweisen, nur sehr selten sind. Über Variation des Substitutionsmusters an einer Spirobifluoreneinheit als zentralen Brückenbaustein konnten zwei isomere Serien von Donor‐Brücke‐Akzeptor‐Verbindungen mit näherungsweise linearer bzw. gewinkelter Geometrie erhalten werden. Der lichtinduzierte ET erfolgt über einen raschen Lochtransfer über die Oligofluorenbrücke über Distanzen von bis zu 70 Å in beiden Serien. Ungeachtet der konformationellen Flexibilität ist ein direkter ET (durch den Raum oder das Lösungsmittel) selbst in der gewinkelten Serie vernachlässigbar. Die Geschwindigkeitskonstante des ET in der gewinkelten Serie ist unabhängig von der Anzahl der Fluorenbrückeneiheiten, was einem geschwindigkeitsbestimmenden Tunnelschritt durch die Spirobifluorenecke zugeschrieben werden kann. Dieser Befund besitzt große Relevanz für multidimensionale ET‐Systeme sowie (supramolekulare) Gitternetze, in denen die Verbindungen der einzelnen molekularen Kabel einen 90°‐Winkel aufweisen.
Synthesis and Applications of Compartmentalised Molecular Polymer Brushes
Authors: Pelras Théophile , Mahon Clare S. , Müllner Markus
Published: February 2018

Polymer science is rapidly advancing towards the precise construction of synthetic macromolecules of formidable complexity. Beyond the impressive advances in control over polymer composition and uniformity enabled by the living polymerisation revolution, the introduction of compartmentalisation within polymer architectures can elevate their functionality beyond that of their constituent parts, thus offering immense potential for the production of tailor‐made nanomaterials. In this Minireview, we discuss synthetic routes to complex molecular brushes with discrete chemical compartments and highlight their potential in the development of advanced materials with applications in nanofabrication, optics and functional materials.
Morphology enhancement of TiO2/PVP composite nanofibers based on solution viscosity and processing parameters of electrospinning method
Authors: Mirmohammad Sadeghi Soraya , Vaezi Mohammadreza , Kazemzadeh Asghar , Jamjah Roghayeh
Published: February 2018

In this work, different sol solutions with various titanium tetraisopropoxide (TIP)/glacial acetic acid ratios in 2‐propanol with 5 wt % poly(vinyl pyrrolidone) (PVP) (Mw = 360,000 g/mol) were prepared and electrospun. Composition of the prepared sols and as‐spun TiO2/PVP nanofibers were determined by Fourier transform infrared and Raman spectroscopy methods. Morphology of the electrospun TiO2/PVP nanofibers was studied by scanning electron microscopy and transmission electron microscopy (TEM) techniques. Rheometry measurements of the sol solutions showed decrease of viscosity upon the addition of TIP to the polymer solutions with constant polymer and acid concentrations. The sol solution having the lowest viscosity (at shear rate 10 s−1) but the highest TIP/glacial acetic acid ratio showed beaded nanofibers morphology when electrospun under 10 and 12 kV applied voltage while injection rate, needle tip to collector distance, and needle gauge were kept constant. However, smooth electrospun TiO2/PVP composite nanofibers with the average nanofibers diameters (148 ± 79 nm) were achieved under the same condition when applied voltage increased to 15 kV. TEM micrographs of the electrospun TiO2/PVP nanofiber showed that the TiO2 particles with continuous structure are formed at the middle of the nanofiber and distributed along its axis. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46337.
Microwave‐Assisted Preparation and Characterization of a Polyoxometalate‐Based Inorganic 2D Framework Anode for Enhancing Lithium‐Ion Battery Performance
Authors: Nie Yan‐Mei , Liang Shuang , Yu Wei‐Dong , Yuan Hao , Yan Jun
Published: February 2018

A pure inorganic 2D network molybdophosphate, [Mn3Mo12O24(OH)6(HPO3)8(H2O)6]4− (1 a), synthesized through microwave irradiation with the existence of Mn2+ and organic cations and isolated as [(CH3)2NH2]3Na[Mn3Mo12O24(OH)6(HPO3)8(H2O)6]⋅12 H2O (1), is found to possess highly enhanced performance in lithium‐ion batteries’ anode materials. The molecule shows multielectron redox properties suitable for producing anode materials with a specific capacity of 602 mA h g−1 at 100 mA g−1 after 50 cycles in lithium‐ion batteries, although its specific capacity is the highest among all the reported pure inorganic 2D polyoxometalates to date, the cyclic stability is not that satisfactory. A hybrid nanocomposite of this 2D network and polypyrrole cations effectively reduces the capacity fading in initial cycles, and increases the stability and improves the electrochemical performance of lithium‐ion batteries as well.
Projected trends of extreme rainfall events from CMIP5 models over Central Africa
Authors: Fotso‐Nguemo Thierry C. , Chamani Roméo , Yepdo Zéphirin D. , Sonkoué Denis , Matsaguim Cédric N. , Vondou Derbetini A. , Tanessong Roméo S.
Published: February 2018

In this study, the projections of daily rainfall from an ensemble mean of 20 global climate models (GCMs) are used to examine projected trends in heavy rainfall distribution over Central Africa (CA), under the representative concentration pathway 8.5. For this purpose, two analyses periods of 40‐years have been selected (2006–2045 and 2056–2095) to compute trends in the 90th and 99th percentiles of the daily rainfall distributions. We found that large increase trend is mostly found in the 99th percentile of rainfall events, over southern Chad, northern Cameroon, northern Zambia, and in the Great Lakes Area. This can be attributed to the increase of moisture convergence intensified by the presence of the Congo Basin rainforest. It is also shown that the largest number of GCMs with a trend of the same sign as the average trend is observed over the above regions. It is thus clear that the projected increase trends in heavy rainfall events may further worse floods which are real problems in the CA countries. Therefore, strong subregional policies are needed to help design effective adaptation and mitigation measures for the region's countries.
Analysis and prediction of a mesoscale convective system over East China with an ensemble square root filter radar data assimilation approach
Authors: Gao Shibo , Min Jinzhong
Published: February 2018

A mesoscale convective system (MCS) over East China on June 5, 2009 was thoroughly analyzed using an Advanced Regional Prediction System (ARPS) ensemble square root filter (EnSRF) system. The analyzed reflectivity structure, location and intensity compared well with observation, and were substantially better than an experiment without radar data assimilation. The cold pool and wind speed in the convective regions were strengthened. With improved initial conditions, the impact of single‐moment (SM), double‐moment (DM) and triple‐moment (TM) microphysics parameterization (MP) schemes on ensemble forecasts of MCSs was evaluated. The use of multi‐moment (MM) MP schemes showed some improvements in neighborhood ensemble probability for reflectivity and precipitation. Quantitative reflectivity and precipitation forecast skills were also improved in MM forecasts, with those of the TM forecast the best.
Teachers ‘liking’ their work? Exploring the realities of teacher Facebook groups
Authors: Bergviken Rensfeldt Annika , Hillman Thomas , Selwyn Neil
Published: February 2018

Social media are now an important aspect of the professional lives of school teachers. This paper explores the growing use of mass ‘teacher groups’ and ‘teacher communities’ on social media platforms such as Facebook. While these online communities are often welcomed as a means of professional learning and support, the paper considers the extent to which Facebook groups also expose teachers to some of the less beneficial aspects of social media, such as various forms of ‘digital labour’, commercialisation of exchanges and predominance of individualised reputation‐driven behaviours. Drawing on a detailed examination of a Swedish teacher Facebook group of over 13,000 members, the paper first addresses aspects of the online community that could be seen as professionally beneficial and/or valuable—particularly in terms of information exchange and social support. Yet while perceived by participants as a relatively beneficial and uncontroversial aspect of their working lives, the research also points to characteristics of the Facebook group that constituted disadvantaging, exploitative and/or disempowering forms of technological engagement. In these terms, the paper highlights tensions between what appears to ‘work’ for individual teachers in the short term and likely longer‐term implications that these practices might have for diminished professionalism and expertise of teachers.
Need (more than) two to Tango: Multiple tools to adapt to changes in oxygen availability
Authors: Fratantonio Deborah , Cimino Francesco , Speciale Antonio , Virgili Fabio
Published: February 2018

Oxygen is a fundamental element for the life of a large number of living organisms allowing an efficient energetic utilization of substrates. Organisms relying on oxygen evolved complex structures for oxygen delivery and biochemical machineries dealing with its safe utilization and the ability to overcome the potentially harmful consequences of changes in oxygen availability. On fact, cells composing complex Eukaryotic organisms are set to live within an optimum narrow range of oxygen, quite specific for each cell type. Minute modifications of oxygen availability, either positive or negative, induce the expression of specific genes, the major actors of this responses being the transcription factors HIF and Nrf2 that control the attempt to cope with low oxygen (hypoxia) or to either high oxygen or to an oxygen “overflow,” respectively. This review describes the interaction between these two transcription factors and their interaction with the transcription factor NF‐κB acting as a pivotal determinant of final cell response. © 2018 BioFactors, 44(3):207–218, 2018
Transcription Factor‐Based Biosensors in High‐Throughput Screening: Advances and Applications
Authors: Cheng Feng , Tang Xiao‐Ling , Kardashliev Tsvetan
Published: February 2018

The molecular mechanisms that cells use to sense changes in the intra‐ and extracellular environment are increasingly utilized in synthetic biology to build genetic reporter constructs for various applications. Although in nature sensing can be RNA‐mediated, most existing genetically‐encoded biosensors are based on transcription factors (TF) and cognate DNA sequences. Here, the recent advances in the integration of TF‐based biosensors in metabolic and protein engineering screens whereas distinction is made between production‐driven and competitive screening systems for enzyme evolution under physiological conditions are discussed. Furthermore, the advantages and disadvantages of existing TF‐based biosensors are examined with respects to dynamic range, sensitivity, and robustness, and compared to other screening approaches. The application examples discussed in this review demonstrate the promising potential TF‐based biosensors hold as screening tools in laboratory evolution of proteins and metabolic pathways, alike.
Site‐Specific Photoconjugation of Beta‐Lactamase Fragments to Monoclonal Antibodies Enables Sensitive Analyte Detection via Split‐Enzyme Complementation
Authors: Yu Feifan , Alesand Veronica , Nygren Per‐Åke
Published: February 2018

Protein fragment complementation assays (PCA) rely on a proximity‐driven reconstitution of a split reporter protein activity, typically via interaction between bait and prey units separately fused to the reporter protein halves. The PCA principle can also be formatted for use in immunossays for analyte detection, e.g., via the use of small immunoglobulin binding proteins (IgBp) as fusion partners to split‐reporter protein fragments for conversion of pairs of antibodies into split‐protein half‐probes. However, the non‐covalent binding between IgBp and antibodies is not ideal for development of robust assays. Here, the authors describe how split‐enzyme reporter halves can be both site‐specifically and covalently photoconjugated at antibody Fc‐parts for use in homogeneous dual‐antibody in vitro immunoassays based on analyte‐dependent split‐enzyme fragment complementation. The half‐probes consist of parts of a beta‐lactamase split‐protein reporter fused to an immunoglobulin Fc binding domain equipped with a unique cysteine residue at which a photoactivable maleimide benzophenone group (MBP) is attached. Using such antibody conjugates the authors obtain an analyte‐driven complementation of the reporter enzyme fragments monitored via conversion of a chromogenic substrate. Results from detection of human interferon‐gamma and the extracellular domain of HER2 is shown. The described principles for site‐specific conjugation of proteins to antibodies should be broadly applicable.
Synthesis and Antiproliferative Activities of 1‐Hydroxyindole‐2‐Carboxylates
Authors: Park Yeon Kyeong , Ryu Yea Seong , Cho Hyunsung , Chung Ha Sook , Lee Sang Hyup
Published: February 2018

Synthesis and evaluation of antiproliferative activities of 1‐hydroxyindole‐2‐carboxylates 1 were described. The toluene compounds 3 were treated with dimethyl oxalate and then, dimethylmethyleneammonium chloride to give intermediates 2. Compounds 2 were converted to desired compounds 1 by application of the reaction of 1‐hydroxyindole formation using SnCl2·2H2O and thiol (or alcohol). The measurements of antiproliferative activities of compounds 1a, 1b, and 1c against several cell lines revealed that compounds 1a and 1c showed strong antiproliferative activities in HCT116 and A2058 cancer cells and could serve as promising lead compounds for further development of anticancer agents.
Mannose‐Decorated Multicomponent Supramolecular Polymers Trigger Effective Uptake into Antigen‐Presenting Cells
Authors: Straßburger David , Stergiou Natascha , Urschbach Moritz , Yurugi Hajime , Spitzer Daniel , Schollmeyer Dieter , Schmitt Edgar , Besenius Pol
Published: February 2018

A modular route to prepare functional self‐assembling dendritic peptide amphiphiles decorated with mannosides, to effectively target antigen‐presenting cells, such as macrophages, is reported. The monomeric building blocks were equipped with tetra(ethylene glycol)s (TEGs) or labeled with a Cy3 fluorescent probe. Experiments on the uptake of the multifunctional supramolecular particles into murine macrophages (Mφs) were monitored by confocal microscopy and fluorescence‐activated cell sorting. Mannose‐decorated supramolecular polymers trigger a significantly higher cellular uptake and distribution, relative to TEG carrying bare polymers. No cytotoxicity or negative impact on cytokine production of the treated Mφs was observed, which emphasized their biocompatibility. The modular nature of the multicomponent supramolecular polymer coassembly protocol is a promising platform to develop fully synthetic multifunctional vaccines, for example, in cancer immunotherapy.
Pneumothorax secondary to pulmonary alveolar microlithiasis
Authors: Devine Oliver P. , Harborne Andrew C.
Published: February 2018

Key Clinical Message

Pulmonary alveolar microlithiasis (PAM) is a rare impairment of pulmonary phosphate clearance that leads to gradual precipitation of intra‐alveolar calcium phosphate microliths. There is often a striking difference between alarming clinical imaging and a relatively well patient. Pneumothorax in PAM often only respond to surgical intervention.
Feasibility of peak volume algorithm in electrothermal vaporization microwave plasma atomic emission spectrometry
Authors: Shan Jin , Jin Wei , Yu Bingwen , Ying Yangwei , Zhu Dan , Yu Haixiang , Yan Yuwei , Jin Qinhan
Published: February 2018

Electro‐thermal vaporization has served as an alternative sample introduction method in atomic spectrometry for some time and provided a better solution for quick analysis of complicated samples because of its high sensitivity and effective separation of analyte from matrix materials. The quick heating process produces sharp signals that can provide much better limits of detection with significant improvements compared with the nebulization sample introduction method. However, it also makes the results worse repeatable, which leads to a worse analytical precision. To improve the precision of the newly developed electrothermal vaporization microwave plasma atomic emission spectrometry and to make good use of the limited data obtained in a limited period of time, some different evaluation methods, such as peak height (symbol, Ih), peak area (symbol, IΣt), and peak volume (symbol, IΣλ‐t) for the results treatment are compared in this paper. It comes out that the results calculated by the optimized peak volume algorithm can significantly improve the precision and retain the high linearity at the same time. Limit of detection of this electrothermal vaporization microwave plasma atomic emission spectrometry system used in this paper for Cu was shown to be 1 μg/L, and the relative standard deviation of 11 repeated measurements can be improved from 10% to 5.6% while retaining good linearity, as expressed by both the squared correlation coefficient obtained with optimized peak volume algorithm and with raw peak height method (squared correlation coefficient of the standard curve R2 > 0.999).
Multifunctional Ionic Liquids from Rhodium(I) Isocyanide Complexes: Thermochromic, Fluorescence, and Chemochromic Properties Based on Rh−Rh Interaction and Oxidative Addition
Authors: Tominaga Takumi , Mochida Tomoyuki
Published: February 2018

Square‐planar rhodium(I) isocyanide complexes exhibit unique chemical reactivities such as the formation of Rh−Rh bonds and oxidative addition. This paper details the syntheses and properties of multifunctional ionic liquids containing RhI isocyanide complexes [Rh(nBuNC)4]X (X=Tf2N (=N(SO2CF3)2−), Nf2N (=N(SO2C4F9)2−), FSA (=N(SO2F)2−), CF3BF3−). Salts with Tf2N and Nf2N were liquids, whereas those with FSA and CF3BF3 were solids at room temperature. The salts exhibited thermochromism in the liquid state, changing from orange at high temperatures to blue‐purple at lower temperatures. This is based on the equilibrium between monomer, dimer, and other oligomers associated with Rh−Rh bond formation. The salts also exhibited fluorescence. Exposure of the Tf2N salt to methyl iodide vapor produced ionic liquid mixtures [Rh(nBuNC)4]x[Rh(nBuNC)4IMe](1−x)[Tf2N], concomitant with a color change from purple to red, orange, and yellow, extending the thermochromic color range. The reaction of the Tf2N salt and iodine produced mononuclear and polynuclear iodine adducts. Thus, these liquids exhibit thermochromism, fluorescence, vapochromism, chemical reactivities, and characteristic properties of ionic liquids.
Methanol Synthesis by CO2 Hydrogenation over Cu/ZnO/Al2O3 Catalysts under Fluctuating Conditions
Authors: Zurbel Alexander , Kraft Michael , Kavurucu‐Schubert Sena , Bertau Martin
Published: February 2018

Methanol synthesis through CO2 hydrogenation under fluctuating conditions was investigated over a CuO/ZnO/Al2O3 catalyst in an integral reactor. The performance of the catalyst was examined under stable conditions at 563 K and 80 bar. For dynamic experiments, the H2/CO2 ratio of the feed gas was changed sequentially. Although the activity and selectivity towards methanol of the catalyst was affected more under dynamic conditions, long‐term stability of the synthesis process was not influenced. The results show that it is possible to operate methanol synthesis with a fluctuating feed gas composition, as it is the case when CO2 is captured from a power plant and H2 from an electrolysis unit driven by a regenerative energy source, such as solar or wind power.
Chemical Conversion of Carbon Dioxide
Authors: Behr Arno , Kuhlmann René
Published: February 2018

Eine Minimierung von Kohlendioxid‐Emissionen wird seit einigen Jahren von Gesellschaft und Politik gefordert. Die hohen verfügbaren Mengen an leicht gewinnbarem CO2 machen auch eine chemische Verwendung des Abfallstoffes zunehmend interessant. Während bereits einige wenige industrielle Prozesse Kohlendioxid großtechnisch verwenden, sind weitere Forschungs‐ und Pilotprojekte mit dem Ziel einer wirtschaftlichen CO2‐Nutzung bereits in Planung. Einige vielversprechende Ansätze zur chemischen CO2‐Verwendung werden in diesem Übersichtsartikel vorgestellt.
Kinetic Modeling of the Palladium‐Catalyzed Isomerizing Methoxycarbonylation of 1‐Decene
Authors: Gerlach Martin , Kirschtowski Sabine , Seidel‐Morgenstern Andreas , Hamel Christof
Published: February 2018

The experimental and model‐based investigation of the palladium‐catalyzed methoxycarbonylation of 1‐decene using methanol and carbon monoxide is presented. The reaction was studied in a thermomorphic solvent system using the industrially applied ligand DTBPMB in order to describe the kinetics of the main and the most relevant side reactions. Based on a reaction analysis, kinetic models including main influencing variables were derived and successfully parametrized. Thus, inhibition effects of the substrate 1‐decene as well as carbon monoxide on the isomerization and methoxycarbonylation rate could be identified.
Hypertension in pregnancy: Taking cues from pathophysiology for clinical practice
Authors: Sava Ruxandra I. , March Keith L. , Pepine Carl J.
Published: February 2018

Pregnancy‐related hypertension (PHTN) syndromes are a frequent and potentially deadly complication of pregnancy, while also negatively impacting the lifelong health of the mother and child. PHTN appears in women likely to develop hypertension later in life, with the stress of pregnancy unmasking a subclinical hypertensive phenotype. However, distinguishing between PHTN and chronic hypertension is essential for optimal management. Preeclampsia (PE) is linked to potentially severe outcomes and lacks effective treatments due to poorly understood mechanisms. Inadequate remodeling of spiral uterine arteries (SUAs), the cornerstone of PE pathophysiology, leads to hypoperfusion of the developing placenta. In normal pregnancies, extravillous trophoblast (EVT) cells assume an invasive phenotype and invade SUAs, transforming them into large conduits. Decidual natural killer cells play an essential role, mediating materno‐fetal immune tolerance, inducing early SUA remodeling and regulating EVT invasiveness. Notch signaling is important in EVT phenotypic switch and is dysregulated in PE. The hypoxic placenta releases antiangiogenic and proinflammatory factors that converge upon maternal endothelium, inducing endothelial dysfunction, hypertension, and organ damage. Hypoxia‐inducible factor 1‐α is upstream of such molecules, whereas endothelin‐1 is a major effector. We also describe important genetic links and evidence of incomplete materno‐fetal immune tolerance, with PE patients presenting with autoantibodies, lower Treg, and higher Th17 cells. Thus, PE manifestations arise as a consequence of mal‐placentation or/and because of a predisposition of the maternal vascular bed to excessively react to pathogenic molecules. From this pathophysiological basis, we provide current and propose future therapeutic directions for PE.
Sex differences in heart failure
Authors: Eisenberg Evann , Di Palo Katherine E. , Piña Ileana L.
Published: February 2018

Heart failure (HF) numbers continue to grow in the United States and approximately 50% of patients living with HF are women. For the provider, it is critical to understand the role that gender plays in recognition, diagnosis, and management. The purpose of this literature review is to highlight the prevalence of heart failure in women and discuss gender variations in epidemiology, symptoms, pharmacology, and treatment as well as examine the representation of women in clinical trials.
TrpM8‐mediated somatosensation in mouse neocortex
Authors: Beukema Patrick , Cecil Katherine L. , Peterson Elena , Mann Victor R. , Matsushita Megumi , Takashima Yoshio , Navlakha Saket , Barth Alison L.
Published: February 2018

Somatosensation is a complex sense mediated by more than a dozen distinct neural subtypes in the periphery. Although pressure and touch sensation have been mapped to primary somatosensory cortex in rodents, it has been controversial whether pain and temperature inputs are also directed to this area. Here we use a well‐defined somatosensory modality, cool sensation mediated by peripheral TrpM8‐receptors, to investigate the neural substrate for cool perception in the mouse neocortex. Using activation of cutaneous TrpM8 receptor‐expressing neurons, we identify candidate neocortical areas responsive for cool sensation. Initially, we optimized TrpM8 stimulation and determined that menthol, a selective TrpM8 agonist, was more effective than cool stimulation at inducing expression of the immediate‐early gene c‐fos in the spinal cord. We developed a broad‐scale brain survey method for identification of activated brain areas, using automated methods to quantify c‐fos immunoreactivity (fos‐IR) across animals. Brain areas corresponding to the posterior insular cortex and secondary somatosensory (S2) show elevated fos‐IR after menthol stimulation, in contrast to weaker activation in primary somatosensory cortex (S1). In addition, menthol exposure triggered fos‐IR in piriform cortex, the amygdala, and the hypothalamus. Menthol‐mediated activation was absent in TrpM8‐knock‐out animals. Our results indicate that cool somatosensory input broadly drives neural activity across the mouse brain, with neocortical signal most elevated in the posterior insula, as well as S2 and S1. These findings are consistent with data from humans indicating that the posterior insula is specialized for somatosensory information encoding temperature, pain, and gentle touch.
Dipeptidyl Peptidase 1 Inhibitor AZD7986 Induces a Sustained, Exposure‐Dependent Reduction in Neutrophil Elastase Activity in Healthy Subjects
Authors: Palmér Robert , Mäenpää Jukka , Jauhiainen Alexandra , Larsson Bengt , Mo John , Russell Muir , Root James , Prothon Susanne , Chialda Ligia , Forte Pablo , Egelrud Torbjörn , Stenvall Kristina , Gardiner Philip
Published: February 2018

Neutrophil serine proteases (NSPs), such as neutrophil elastase (NE), are activated by dipeptidyl peptidase 1 (DPP1) during neutrophil maturation. High NSP levels can be detrimental, particularly in lung tissue, and inhibition of NSPs is therefore an interesting therapeutic opportunity in multiple lung diseases, including chronic obstructive pulmonary disease (COPD) and bronchiectasis. We conducted a randomized, placebo‐controlled, first‐in‐human study to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of single and multiple oral doses of the DPP1 inhibitor AZD7986 in healthy subjects. Pharmacokinetic and pharmacodynamic data were analyzed using nonlinear mixed effects modeling and showed that AZD7986 inhibits whole blood NE activity in an exposure‐dependent, indirect manner—consistent with in vitro and preclinical predictions. Several dose‐dependent, possibly DPP1‐related, nonserious skin findings were observed, but these were not considered to prevent further clinical development. Overall, the study results provided confidence to progress AZD7986 to phase II and supported selection of a clinically relevant dose.
Organ‐on‐Chip Recapitulates Thrombosis Induced by an anti‐CD154 Monoclonal Antibody: Translational Potential of Advanced Microengineered Systems
Authors: Barrile Riccardo , van der Meer Andries D. , Park Hyoungshin , Fraser Jacob P. , Simic Damir , Teng Fang , Conegliano David , Nguyen Justin , Jain Abhishek , Zhou Mimi , Karalis Katia , Ingber Donald E. , Hamilton Geraldine A. , Otieno Monicah A.
Published: February 2018

Clinical development of Hu5c8, a monoclonal antibody against CD40L intended for treatment of autoimmune disorders, was terminated due to unexpected thrombotic complications. These life‐threatening side effects were not discovered during preclinical testing due to the lack of predictive models. In the present study, we describe the development of a microengineered system lined by human endothelium perfused with human whole blood, a “Vessel‐Chip.” The Vessel‐Chip allowed us to evaluate key parameters in thrombosis, such as endothelial activation, platelet adhesion, platelet aggregation, fibrin clot formation, and thrombin anti‐thrombin complexes in the Chip‐effluent in response to Hu5c8 in the presence of soluble CD40L. Importantly, the observed prothrombotic effects were not observed with Hu5c8‐IgG2σ designed with an Fc domain that does not bind the FcγRIIa receptor, suggesting that this approach may have a low potential risk for thrombosis. Our results demonstrate the translational potential of Organs‐on‐Chips, as advanced microengineered systems to better predict human response.