bluuebunny/crossref_metadata_2025 huggingface dataset:
Interpreting the Ultraviolet Aerosol Index observed with the OMI satellite instrument to understand absorption by organic aerosols: implications for atmospheric oxidation and direct radiative effects
Authors: Hammer M. S. , Martin R. V. , van Donkelaar A. , Buchard V. , Torres O. , Ridley D. A. , Spurr R. J. D.
Published: October 2015

Abstract. Satellite observations of the Ultraviolet Aerosol Index (UVAI) are sensitive to absorption of solar radiation by aerosols; this absorption affects photolysis frequencies and radiative forcing. We develop a global simulation of the UVAI using the 3-D chemical transport model GEOS-Chem coupled with the Vector Linearized Discrete Ordinate Radiative Transfer model (VLIDORT). The simulation is applied to interpret UVAI observations from the Ozone Monitoring Instrument (OMI) for the year 2007. Simulated and observed values are highly consistent in regions where mineral dust dominates the UVAI, but a large negative bias (−0.32 to −0.97) exists between simulated and observed values in biomass burning regions. We determine effective optical properties for absorbing organic aerosol, known as brown carbon (BrC), and implement them into GEOS-Chem to better represent observed UVAI values over biomass burning regions. The addition of absorbing BrC decreases the mean bias between simulated and OMI UVAI values from −0.57 to −0.09 over West Africa in January, from −0.32 to +0.0002 over South Asia in April, from −0.97 to −0.22 over southern Africa in July, and from −0.50 to +0.33 over South America in September. The spectral dependence of absorption after adding BrC to the model is broadly consistent with reported observations for biomass burning aerosol, with Absorbing Angstrom Exponent (AAE) values ranging from 2.9 in the ultraviolet (UV) to 1.3 across the UV-Near IR spectrum. We assess the effect of the additional UV absorption by BrC on atmospheric photochemistry by examining tropospheric hydroxyl radical (OH) concentrations in GEOS-Chem. The inclusion of BrC decreases OH by up to 35 % over South America in September, up to 25 % over southern Africa in July, and up to 20 % over other biomass burning regions. Global annual mean OH concentrations in GEOS-Chem decrease due to the presence of absorbing BrC, increasing the methyl chloroform lifetime from 5.62 to 5.68 years, thus reducing the bias against observed values. We calculate the direct radiative effect (DRE) of BrC using GEOS-Chem coupled with the radiative transfer model RRTMG (GC-RT). Treating organic aerosol as containing absorbing BrC rather than as primarily scattering changes global annual mean all-sky top of atmosphere (TOA) DRE by +0.05 W m-2 and all-sky surface DRE by −0.06 W m-2. Regional changes of up to +0.5 W m-2 at TOA and down to −1 W m-2 at the surface are found over major biomass burning regions.
Phosphorus fertilisation under nitrogen limitation can deplete soil carbon stocks – evidence from Swedish meta-replicated long-term field experiments
Authors: Poeplau C. , Bolinder M. A. , Kirchmann H. , Kätterer T.
Published: October 2015

Abstract. Increasing soil organic carbon (SOC) in agricultural soils can mitigate atmospheric CO2 concentration and also contribute to increase soil fertility and ecosystem resilience. The role of major nutrients on SOC dynamics is complex, due to simultaneous effects on net primary productivity (NPP) that influence crop residue carbon inputs and on the rate of heterotrophic respiration (carbon outputs). This study investigated the effect on SOC stocks of three different levels of phosphorus and potassium (PK) fertilisation rates in the absence of nitrogen fertilisation and of three different levels of nitrogen in the absence of PK. This was done by analysing data from 10 meta-replicated Swedish long-term field experiments (> 45 years). With N fertilisation, SOC stocks followed yield increases. However, for all PK levels, we found average SOC losses ranging from −0.04 ± 0.09 Mg ha−1 yr−1 (ns) for the lowest to −0.09 ± 0.07 Mg ha−1 yr−1 (p = 0.008) for the highest application rate, while crop yields as a proxy for carbon input increased significantly with PK fertilization by 1, 10 and 15 %. We conclude that SOC dynamics are mainly output-driven in the PK fertilised regime but mostly input-driven in the N fertilised regime, due to the much more pronounced response of NPP to N than to PK fertilisation. It has been established that P rather than K is the element affecting ecosystem carbon fluxes, where P fertilisation has been shown to: (i) stimulate heterotrophic respiration, (ii) reduce the abundance of arbuscular mycorrhizal fungi and (iii) decrease crop root : shoot ratio, leading to lower root-derived carbon input. The higher export of N in the PK fertilised plots in this study could (iv) have led to increased N mining and thus mineralisation of organic matter. More integrated experiments are needed to gain a better understanding of the relative importance of each of the above-mentioned mechanisms leading to SOC losses after P addition.
Climate-driven expansion of blanket bogs in Britain during the Holocene
Authors: Gallego-Sala A. V. , Charman D. J. , Harrison S. P. , Li G. , Prentice I. C.
Published: October 2015

Abstract. Blanket bog occupies approximately 6 % of the area of the UK today. The Holocene expansion of this hyperoceanic biome has previously been explained as a consequence of Neolithic forest clearance. However, the present distribution of blanket bog in Great Britain can be predicted accurately with a simple model (PeatStash) based on summer temperature and moisture index thresholds, and the same model correctly predicts the highly disjunct distribution of blanket bog worldwide. This finding suggests that climate, rather than land-use history, controls blanket-bog distribution in the UK and everywhere else. We set out to test this hypothesis for blanket bogs in the UK using bioclimate envelope modelling compared with a database of peat initiation age estimates. We used both pollen-based reconstructions and climate model simulations of climate changes between the mid-Holocene (6000 yr BP, 6 ka) and modern climate to drive PeatStash and predict areas of blanket bog. We compiled data on the timing of blanket-bog initiation, based on 228 age determinations at sites where peat directly overlies mineral soil. The model predicts large areas of northern Britain would have had blanket bog by 6000 yr BP, and the area suitable for peat growth extended to the south after this time. A similar pattern is shown by the basal peat ages and new blanket bog appeared over a larger area during the late Holocene, the greatest expansion being in Ireland, Wales and southwest England, as the model predicts. The expansion was driven by a summer cooling of about 2 °C, shown by both pollen-based reconstructions and climate models. The data show early Holocene (pre-Neolithic) blanket-bog initiation at over half of the sites in the core areas of Scotland, and northern England. The temporal patterns and concurrence of the bioclimate model predictions and initiation data suggest that climate change provides a parsimonious explanation for the early Holocene distribution and later expansion of blanket bogs in the UK, and it is not necessary to invoke anthropogenic activity as a driver of this major landscape change.
Inconsistent strategies to spin up models in CMIP5: implications for ocean biogeochemical model performance assessment
Authors: Séférian R. , Gehlen M. , Bopp L. , Resplandy L. , Orr J. C. , Marti O. , Dunne J. P. , Christian J. R. , Doney S. C. , Ilyina T. , Lindsay K. , Halloran P. , Heinze C. , Segschneider J. , Tjiputra J.
Published: October 2015

Abstract. During the fifth phase of the Coupled Model Intercomparison Project (CMIP5) substantial efforts were carried out on the systematic assessment of the skill of Earth system models. One goal was to check how realistically representative marine biogeochemical tracer distributions could be reproduced by models. Mean-state assessments routinely compared model hindcasts to available modern biogeochemical observations. However, these assessments considered neither the extent of equilibrium in modeled biogeochemical reservoirs nor the sensitivity of model performance to initial conditions or to the spin-up protocols. Here, we explore how the large diversity in spin-up protocols used for marine biogeochemistry in CMIP5 Earth system models (ESM) contribute to model-to-model differences in the simulated fields. We take advantage of a 500 year spin-up simulation of IPSL-CM5A-LR to quantify the influence of the spin-up protocol on model ability to reproduce relevant data fields. Amplification of biases in selected biogeochemical fields (O2, NO3, Alk-DIC) is assessed as a function of spin-up duration. We demonstrate that a relationship between spin-up duration and assessment metrics emerges from our model results and is consistent when confronted against a larger ensemble of CMIP5 models. This shows that drift has implications on their performance assessment in addition to possibly aliasing estimates of climate change impact. Our study suggests that differences in spin-up protocols could explain a substantial part of model disparities, constituting a source of model-to-model uncertainty. This requires more attention in future model intercomparison exercices in order to provide realistic ESM results on marine biogeochemistry and carbon cycle feedbacks.
L’Église-nation canadienne-française au siècle des nationalités : regard croisé sur l’ultramontanisme et le nationalisme
Authors: Laniel Jean-François
Published: October 2015

L’influence de la doctrine et de la pensée ultramontaines au Canada français, de ses réseaux et de ses luttes politico-religieuses, a fait l’objet de nombreuses recherches. Cependant, l’étude de ses aspects originaux eu égard à la question nationale reste peu explorée. Contrairement à l’ultramontanisme français – monarchiste, critique des Églises nationales et résolument en faveur d’un catholicisme universaliste – sa variante canadienne-française a fait sienne une certaine idée romantique de la nation : l’avènement d’une « contre-société » intégralement catholique s’y est fait projet d’édification nationale. C’est sur cette « affinité élective » entre l’ultramontanisme et le nationalisme canadien-français que porte cet article. En effet, la traduction sociopolitique de l’ultramontanisme mennaisien en sol canadien-français n’est pas sans réserver plusieurs surprises, qu’aident à cerner le rôle providentiel dévolu au peuple et à ses coutumes, son ambition d’institutionnalisation du social et son parti pris farouche pour l’autonomie de l’Église. À ce titre, la pensée « réformiste » d’Étienne Parent, sur laquelle Fernand Ouellet a déjà souligné l’influence des « doctrines théocratiques », exprime ce mélange de nationalisme et d’ultramontanisme, et suggère l’attrait plus large qu’il suscite dans le cadre tumultueux de l’Acte d’Union du Haut et du Bas Canada, puis du « renouveau religieux ». Une telle analyse permet a fortiori de situer le nationalisme canadien-français parmi les types d’édification nationale, ceux des « nations culturelles sans État souverain », où précisément la constitution d’une « Église-nation » est susceptible d’advenir.
Clercs et historiens : le discours d’enracinement et la Société historique du Nouvel-Ontario
Authors: St-Pierre Stéphanie
Published: October 2015

Les contributions de l’Église catholique sont nombreuses en ce qui a trait aux communautés minoritaires de langue française de l’Amérique du Nord, mais qu’en est-il de l’historiographie? La production historique de langue française en Amérique du Nord nous permet de constater que les membres du clergé forment la majorité des auteurs de la première heure. Cet article porte sur le rôle du clergé dans l’émergence d’une réflexion historique de langue française en milieu minoritaire avec, comme moment charnière, la fondation de la Société historique du Nouvel-Ontario en 1942. Nous nous intéresserons au rôle du clergé à titre de membres et d’auteurs en ciblant plus particulièrement les contributions de Lorenzo Cadieux et Stéphane Côté au cours des premières années d’existence de la Société. En rattachant cette production historique à l’historiographie régionale, nous chercherons à mieux comprendre l’émergence d’un discours à saveur identitaire, par l’entremise des références au passé, au cours des premières années d’existence de la Société.
Multi-Dimensional Responsible Rural Tourism Capacity (RRTC) Framework: A Proposed Environmental Responsibility and Management Model for Malaysia
Authors: Nair Vikneswaran , Mohamed Badaruddin , Chiun Lo May
Published: October 2015

Malaysia is regarded as a heaven for ecotourism and natural resources. Nonetheless, the very concept of ecotourism is confused with massive “greenwashing” that is destroying many pristine destinations especially in the rural settings. Various tourism models emphasising on the environment have been developed in the past in Malaysia with no holistic understanding of their impact to the natural environment. With this challenge in mind, this paper aims to understand and propose an environmental model that is able to balance the natural and economic environment in line with Malaysia’s Economic Transformation Programme where rural tourism is expected to alleviate from a low-yield to a high-yield economy. This will be achieved by developing suitable indicators to make the rural tourism business model sustainable. The first three years of the five year research (2011-2016) were involved in developing the fundamental aspects of the study, with emphasis on the establishment of baseline data and carrying out situational analyses at the ten selected study areas to help develop the indicators. The final two years will evaluate the performance of these sites using the developed indicators. Hence, this fundamental study is necessary to understand the various dimensions that are essential in investigating the relationships between different tourism models and how they are closely linked to the local economies and environments in key “natural” destinations in Malaysia.
Destination Performance: Importance of Redefining DMOs
Authors: Kaurav Rahul Pratap Singh , Baber Ruturaj , Chowdhary Nimit , Kapadia Shakir
Published: October 2015

There is a huge gap in defining the core concept of destination, performance and its marketing / management organisation. This review paper intends to study the aforesaid gap and aid the concept in defining it from different perspectives. The chosen study also highlights the burning need of researchers and students alike in serving the definitional aspect from the literature point of view. The main focus is however on the gaps between defining Destination, Destination Performance and Destination Management / Marketing Organisations (DMOs). We bring in the literature review to define the concepts for today’s scholars as transfiguring for the current tourism industry. In considering the factors affecting the performance of a destination, the research considered eight specific variables i.e., revenue generation, employment generation, investment in tourism-related business, development of basic infrastructure, cultural exchange between tourists and host communities, increasing number of parks and recreational facilities, intra-generational equity and inter-generational equity. These variables were chosen on the merits that make a destination successful in the true sense. The findings also bring insights from the tourism industry to understand better all the key stakeholders. The definitions and model derived can be a supporting pillar for planners and managers of DMOs in crafting a suitable strategy to obtain a better performance from all stakeholders. The main significance of the findings is to help various government departments, agencies, consultancies and NTOs who can visualise and actively use these definitions for policy planning and implementation. This is also a step forward towards regaining the importance of destination with performance, management, marketing and organisation.
IPCC Report Calls Climate Changes Unprecedented
Authors: Showstack Randy
Published: October 2015

Warming of the Earth's climate “is unequivocal and since the 1950s many of the observed changes are unprecedented over decades to millennia,” according to a new assessment report by the Intergovernmental Panel on Climate Change (IPCC). The 27 September summary for policy makers of IPCC's report “Climate Change 2013: The Physical Science Basis” also states that “it is extremely likely that human influence has been the dominant cause of the observed warming since the mid‐20th century.”
Hayes Receives 2012 Ronald Greeley Early Career Award in Planetary Science: Citation
Authors: Leshin Laurie A.
Published: October 2015

Alexander G. Hayes Jr. received the 2012 Ronald Greeley Early Career Award in Planetary Science at the 2012 AGU Fall Meeting, held 3–7 December in San Francisco, Calif. The award recognizes significant early‐career contributions to planetary science.
Squyres Receives 2012 Whipple Award: Response
Authors: Squyres Steven W.
Published: October 2015

I started down this road a long time ago, and I've had the good fortune to be guided by many people along the way. Joe Veverka was my advisor in grad school, and he taught me both how to do science and, by his example, how to be a generous mentor and colleague. Joe was last year's recipient of the Whipple Award, and in a lovely twist, Joe's advisor when he was in grad school was none other than Fred Whipple himself. So I dedicate this to my academic father and my academic grandfather.
Crowdsourcing urban air temperature measurements using smartphones
Authors: Balcerak Ernie
Published: October 2015

Crowdsourced data from cell phone battery temperature sensors could be used to contribute to improved real‐time, high‐resolution air temperature estimates in urban areas, a new study shows. Temperature observations in cities are in some cases currently limited to a few weather stations, but there are millions of smartphone users in many cities. The batteries in cell phones have temperature sensors to avoid damage to the phone.
Drawing Time
Authors: Clear Nic
Published: October 2015

Head of the Department of Architecture and Landscape Architecture at the University of Greenwich, Nic Clear is renowned for his role in championing film and animation techniques in architectural education. Here he challenges architects to put aside their assigned roles as mere imagers or practice technicians and embrace ‘the spatial possibilities offered by a whole range of emerging design activities ‐ actual, augmented and virtual’.
Self‐Assembled Proteins and Peptides as Scaffolds for Tissue Regeneration
Authors: Loo Yihua , Goktas Melis , Tekinay Ayse B. , Guler Mustafa O. , Hauser Charlotte A. E. , Mitraki Anna
Published: October 2015

Self‐assembling proteins and peptides are increasingly gaining interest for potential use as scaffolds in tissue engineering applications. They self‐organize from basic building blocks under mild conditions into supramolecular structures, mimicking the native extracellular matrix. Their properties can be easily tuned through changes at the sequence level. Moreover, they can be produced in sufficient quantities with chemical synthesis or recombinant technologies to allow them to address homogeneity and standardization issues required for applications. Here. recent advances in self‐assembling proteins, peptides, and peptide amphiphiles that form scaffolds suitable for tissue engineering are reviewed. The focus is on a variety of motifs, ranging from minimalistic dipeptides, simplistic ultrashort aliphatic peptides, and peptide amphiphiles to large “recombinamer” proteins. Special emphasis is placed on the rational design of self‐assembling motifs and biofunctionalization strategies to influence cell behavior and modulate scaffold stability. Perspectives for combination of these “bottom‐up” designer strategies with traditional “top‐down” biofabrication techniques for new generations of tissue engineering scaffolds are highlighted.
Hierarchical Nanofibrous Microspheres with Controlled Growth Factor Delivery for Bone Regeneration
Authors: Ma Chi , Jing Yan , Sun Hongchen , Liu Xiaohua
Published: October 2015

The integration of controlled growth factor delivery and biomimetic architecture into a microsphere is a challenging but attractive strategy for developing new injectable biomaterials. In this work, a unique hierarchical nanosphere‐encapsulated‐in‐microsphere scaffolding system is developed. First, heparin‐conjugated gelatin (HG) is synthesized, which provides binding domains for bone morphogenetic protein 2 (BMP2) to stabilize this growth factor, protect it from denaturation and proteolytic degradation, and subsequently prolong its sustained release. Next, a unique approach is developed which includes a water‐in‐oil‐in‐oil double emulsion process and a thermally induced phase separation to encapsulate BMP2‐binding HG nanospheres into nanofibrous microspheres. The nanofibrous microsphere is self‐assembled from synthetic nanofibers, and has superior surface area, high porosity, low density, and is an excellent carrier to support cell adhesion and tissue in‐growth. BMP2 in the hierarchical microsphere is released in a multiple‐controlled manner by the binding with heparin and encapsulation of the nanosphere and microsphere. An in vivo calvarial defect model confirms that this microsphere is an excellent osteoinductive scaffold for enhanced bone regeneration. By choosing different growth factors, this hierarchical microsphere system can easily be applied to other types of tissue regeneration. The work expands the ability to develop new injectable biomaterials for advanced regenerative therapies.
Silver Tetrafluoroborate‐Catalyzed Oxa‐Diels–Alder Reaction Between Electrically Neutral Dienes and Aldehydes
Authors: Zou Xiaodong , Yang Lizheng , Liu Xiangli , Sun Hao , Lu Hongjian
Published: October 2015

Chemoselective oxa‐Diels–Alder reactions between electrically neutral 1,3‐dienes and various aldehydes were achieved using the commercially available silver tetrafluoroborate (AgBF4) as catalyst. This catalytic process has high functional group tolerance. Heteroatoms at the β‐position of the aryl aldehydes can greatly promote the reactivity of the substrates even with heterocyclic aldehydes that were previously believed to be unreactive for the oxa‐Diels–Alder reaction. In addition, acroleins with β‐heteroatom substitution are also good substrates. High chemoselectivity and regioselectivity were achieved at room temperature for the oxa‐Diels–Alder reaction between acroleins and stoichiometric simple 1,3‐dienes.

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Homogeneous Gold‐Catalyzed Cyclization Reactions of Alkynes with N‐ and S‐Nucleophiles
Authors: Debrouwer Wouter , Heugebaert Thomas S. A. , Roman Bart I. , Stevens Christian V.
Published: October 2015

This review covers the formation of N‐ and S‐containing heterocycles, initiated by gold‐catalyzed nucleophilic attack of N‐ or S‐nucleophiles onto alkynes. These types of nucleophiles have been somewhat overlooked as compared to their C‐ or O‐counterparts in other reviews. In this particular work, their intramolecular gold‐mediated attack onto alkynes is reviewed in depth. It is structured in such a fashion that the reader will get a clear view of which substrates react in which cyclization mode.

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Palladium‐Catalyzed Carbonylations of Arylboronic Acids: Synthesis of Arylcarboxylic Acid Ethyl Esters
Authors: Liang Apeng , Han Shuaijun , Wang Liang , Li Jingya , Zou Dapeng , Wu Yangjie , Wu Yusheng
Published: October 2015

An approach for the palladium‐catalyzed ethoxycarbonylations of arylboronic acids using diethyl pyrocarbonate as carbon monoxide/carbon dioxide (CO/CO2) surrogate in moderate to good yields has been investigated.

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Ynones Merge Activation/Conjugate Addition of Chalcogenoborates ArE‐Bpin (E=Se, S)
Authors: Civit Marc G. , Sanz Xavier , Vogels Christopher M. , Bo Carles , Westcott Stephen A. , Fernández Elena
Published: October 2015

The “pull–push” effect of the Bpin moiety in ArE‐Bpin reagents (E=Se, S) is demonstrated by the Lewis acid interaction with the carbonyl group of ynones and the concomitant delivery of ArSe or ArS to the electron‐deficient alkyne with impressive stereoselectivity. The two component reactivity is carried out in methanol to generate (Z)‐β‐(arylseleno)‐α,β‐unsaturated ketones and (Z)‐β‐(arylsulfuro)‐α,β‐unsaturated ketones with a consensus between experimental and theoretical understanding of the mechanism.

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1,5‐Diketones Synthesis via Three‐Component Cascade Reaction
Authors: Xing Li‐Juan , Lu Tao , Fu Wei‐Li , Lou Mei‐Mei , Chen Bo , Wang Zhi‐Shen , Jin Yang , Li Dan , Wang Bin
Published: October 2015

A mild and efficient cascade synthesis of 1,5‐diketones from readily available N,N‐dicyclohexylmethylamine, 1,3‐dicarbonyl compounds, and trifluoromethyl β‐diketones has been developed. This cascade reaction occurs via an oxidation/Mannich reaction/Cope elimination/Michael addition/retro‐Claisen reaction sequence, and provides multiple CC bond formations in one pot. In addition, exquisite chemoselectivity is achieved in the reaction between 1,3‐dicarbonyl compounds and trifluoromethyl β‐diketones.

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Enantioselective Michael Addition of Nitroalkanes to Nitroalkenes Catalyzed by Chiral Bifunctional Quinine‐Based Squaramides
Authors: Kanberoğlu Esra , Tanyeli Cihangir
Published: October 2015

A family of chiral bifunctional acid‐/base‐type quinine/squaramide organocatalysts is shown to be highly active promoters of the conjugate addition of 1‐nitropropane to various trans‐β‐nitroalkenes. The cooperation of the quinine and the sterically encumbered squaramide moieties catalyzed the Michael addition reactions at 0 °C by using a catalyst loading of only 2 mol % to afford the 1,3‐dinitro Michael adducts with excellent enantioselectivity and diastereoselectivity (up to 95 % ee and syn/anti isomers up to 96:4).
Einfacher Zugang zu α‐Fluoralkylammoniumsalzen
Authors: Baxter Amanda F. , Christe Karl O. , Haiges Ralf
Published: October 2015

Eine Serie neuartiger α‐Fluoralkylammoniumsalze wurde aus den entsprechenden Cyanverbindungen durch Reaktion mit wasserfreiem HF hergestellt. Raumtemperaturbeständige Trifluormethylammoniumsalze wurden in quantitativer Ausbeute durch eine einfache Reaktion aus den kommerziell verfügbaren Ausgangsverbindungen BrCN und ClCN erhalten. Die neuen Kationen [CF3CF2NH3]+, [HCF2CF2NH3]+ und [(NH3CF2)2]2+ wurden aus HF und CF3CN, HCF2CN bzw. (CN)2 hergestellt. Die genannten fluorierten Ammoniumkationen wurden als bei Raumtemperatur stabile [AsF6]−‐ und/oder [SbF6]−‐Salze isoliert und durch multinukleare NMR‐ sowie Schwingungsspektroskopie charakterisiert. Die Salze [HCF2NH3][AsF6] und [CF3NH3][Sb2F11] wurden zusätzlich durch ihre Röntgenkristallstrukturen charakterisiert.
Clickable Nucleic Acids: Sequence‐Controlled Periodic Copolymer/Oligomer Synthesis by Orthogonal Thiol‐X Reactions
Authors: Xi Weixian , Pattanayak Sankha , Wang Chen , Fairbanks Benjamin , Gong Tao , Wagner Justine , Kloxin Christopher J. , Bowman Christopher N.
Published: October 2015

Synthetic polymer approaches generally lack the ability to control the primary sequence, with sequence control referred to as the holy grail. Two click chemistry reactions were now combined to form nucleobase‐containing sequence‐controlled polymers in simple polymerization reactions. Two distinct approaches are used to form these click nucleic acid (CNA) polymers. These approaches employ thiol–ene and thiol‐Michael reactions to form homopolymers of a single nucleobase (e.g., poly(A)n) or homopolymers of specific repeating nucleobase sequences (e.g., poly(ATC)n). Furthermore, the incorporation of monofunctional thiol‐terminated polymers into the polymerization system enables the preparation of multiblock copolymers in a single reaction vessel; the length of the diblock copolymer can be tuned by the stoichiometric ratio and/or the monomer functionality. These polymers are also used for organogel formation where complementary CNA‐based polymers form reversible crosslinks.
A General Strategy for Targeting Drugs to Bone
Authors: Jahnke Wolfgang , Bold Guido , Marzinzik Andreas L. , Ofner Silvio , Pellé Xavier , Cotesta Simona , Bourgier Emmanuelle , Lehmann Sylvie , Henry Chrystelle , Hemmig René , Stauffer Frédéric , Hartwieg J. Constanze D. , Green Jonathan R. , Rondeau Jean‐Michel
Published: October 2015

Targeting drugs to their desired site of action can increase their safety and efficacy. Bisphosphonates are prototypical examples of drugs targeted to bone. However, bisphosphonate bone affinity is often considered too strong and cannot be significantly modulated without losing activity on the enzymatic target, farnesyl pyrophosphate synthase (FPPS). Furthermore, bisphosphonate bone affinity comes at the expense of very low and variable oral bioavailability. FPPS inhibitors were developed with a monophosphonate as a bone‐affinity tag that confers moderate affinity to bone, which can furthermore be tuned to the desired level, and the relationship between structure and bone affinity was evaluated by using an NMR‐based bone‐binding assay. The concept of targeting drugs to bone with moderate affinity, while retaining oral bioavailability, has broad application to a variety of other bone‐targeted drugs.
Spontaneous Resolution of an Electron‐Deficient Tetrahedral Fe4L4 cage
Authors: Bonakdarzadeh Pia , Pan Fangfang , Kalenius Elina , Jurček Ondřej , Rissanen Kari
Published: October 2015

A highly electron‐deficient C3‐symmetric tris(bipyridyl) ligand was prepared in four steps and used for the coordination of Fe(OTf)2, thereby resulting in the homochiral assembly of a new family of robust tetrahedral M4L4 cages. This homochiral T‐symmetric cage containing a relatively large cavity of 330 Å3 is capable of encapsulating an anionic guest, as was determined by mass spectrometry, 19F NMR spectroscopy, and finally shown from its crystal structure. Moreover, crystallization of the cage from CH3CN led to crystals containing both (ΔΔΔΔ and ΛΛΛΛ) enantiomers, while crystallization from CH3OH resulted in crystals containing only the right‐handed (ΔΔΔΔ) cage. The difference in the crystal packing of the two crystal structures is discussed and a feasible explanation for the unique phenomenon among supramolecular cages—spontaneous resolution—is given.
Cell morphology and mechanical properties of microcellular mucell® injection molded polyetherimide and polyetherimide/fillers composite foams
Authors: Li Jingli , Chen Zhenglun , Wang Xianzhong , Liu Tao , Zhou Yufeng , Luo Shikai
Published: October 2015

Microcellular polyetherimide (PEI) foams were prepared by microcellular injection molding using supercritical nitrogen (SC‐N2) as foaming agent. The effects of four different processing parameters including shot size, injection speed, SC‐N2 content, and mold temperature on cell morphology and material properties were studied. Meanwhile, multiwalled carbon nanotube (MWCNT), nano‐montmorillonoid (NMMT), and talcum powder (Talc) were introduced into PEI matrix as heterogeneous nucleation agents in order to further improve the cell morphology and mechanical properties of microcellular PEI foams. The results showed that the processing parameters had great influence on cell morphology. The lowest cell size can reach to 18.2 μm by optimizing the parameters of microcellular injection molding. Moreover, MWCNT can remarkably improve the cell morphology of microcellular PEI foams. It was worth mentioning that when the MWCNT content was 1 wt %, the microcellular PEI/MWCNT foams displayed optimum mechanical properties and the cell size decreased by 28.3% compared with microcellular PEI foams prepared by the same processing parameters. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4171–4181, 2013
Polyacrylate emulsion containing IBOMA for removable pressure sensitive adhesives
Authors: Zhang Lei , Cao Yingjie , Wang Lei , Shao Lu , Bai Yongping
Published: October 2015

In the area of pressure sensitive adhesives (PSAs), corona treatment or other preprocessing on the carrier was commonly utilized for the enhancement of the interaction between the adhesive layer and the carrier, with complicated procedures and operations. To make it easy, one‐pot emulsion polymerization using n‐butyl acrylate, isobornyl methacrylate (IBOMA), 2‐hydroxyethyl acrylate and acrylic acid was conducted in the presence of a reactive emulsifier SR‐20 to obtain a reinforced adhesive tape. First, the emulsion had good stabilities, especially freeze‐thaw stability, which was helpful to the fabrication of PSAs. Second, IBOMA increased the binding strength between adhesive layer and adherend. The properties of the final tapes well fulfilled the requirements of this areas, such as that the 180° peel strength of 125.9 N/m when coated on non‐corona surfaces, the tack of 19 #, and the shear holding time of more than 100 h. Third, the tapes produced using the above emulsion could be removed many times, with no PSAs residue on the adherend even when coated on untreated PP, which showed the potential of recycling and environmental protection. Thus, these properties make the polyacrylate emulsion have great potential for practical applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42886.
Effects of l‐aspartic acid and poly(butylene succinate) on thermal stability and mechanical properties of poly(propylene carbonate)
Authors: Yun Xueyan , Wu Jiaxin , Wang Yu , Zhao Zilong , Jin Ye , Dong Tungalag
Published: October 2015

Poly(propylene carbonate) (PPC) was modified by l‐aspartic acid (Asp) and poly(butylene succinate) (PBS). To assess the effects of Asp and PBS on the thermal stability, mechanical properties of PPC, different PPC/Asp, PPC/PBS, and PPC/PBS/Asp blends were prepared by twin‐screw extruder. The results indicated that the thermal stability improved with the Asp content increasing from 0.5 to 5%. With trace presence of 2% Asp, the degradation temperature of PPC was greatly increased upon extruding and the Yield strength and Young's modulus increased 62 and 849 times, respectively, at 20°C. The flexibility of PPC was effectively improved by blending with PBS, the PBS has no significant effect on the thermal stability of PPC until PBS up to enough amount. Besides the Asp additive in PPC/PBS blends not only improved the thermal stability PPC, but improved the interfacial compatibility of the blend. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42970.
Recent Developments in Androgen Receptor Antagonists
Authors: Ran Fansheng , Xing Hualu , Liu Yang , Zhang Daoguang , Li Pengzhan , Zhao Guisen
Published: October 2015

The androgen receptor (AR), a ligand‐dependent transcription factor that regulates the expression of a series of downstream target genes after the binding of androgens, has been a target for the discovery of drugs used to treat prostate cancer. Prostate cancer always progresses to castration‐resistant prostate cancer after a period of androgen deprivation therapy. Thus, developing potent androgen receptor antagonists for the therapy of castration‐resistant prostate cancer possesses great significance. This review summarizes the preclinical development of androgen receptor antagonists, conventional androgen receptor antagonists that competitively bind to the ligand binding domain of the androgen receptor and coactivator antagonists of the androgen receptor, including both activation function‐2 antagonists and binding function‐3 antagonists. We hope that this review can help other researchers find new scaffolds and sites for the treatment of prostate cancer.
Design and Synthesis of Novel Phenylpiperazine Derivatives as Potential Anticonvulsant Agents
Authors: Habib Monica M. W. , Abdelfattah Mohamed A. O. , Abadi Ashraf H.
Published: October 2015

Eighteen new 5‐benzylidene‐3‐(4‐arylpiperazin‐1‐ylmethyl)‐2‐thioxo‐imidazolidin‐4‐ones were designed as hybrid structures from previously reported anticonvulsant compounds, synthesized and tested for anticonvulsant activity. Initial anticonvulsant screening was performed using the strychnine (2 mg/kg IP) potent generalized‐induced seizure and pentylenetetrazole (PTZ) (60 mg/kg IP) acute clonic‐induced convulsion screens in mice. All the molecules were found to be effective in at least one seizure model, compounds 10, 13, 15, 17, and 18 were active against both types of seizures induced. Compound 13 turned out to be the most active candidate within the strychnine model, having an average survival time of 6 min close to that of the positive control phenytoin, while compound 8 showed 100% protection from the induced PTZ seizures, resembling the protection of the positive control phenobarbital. Initial SAR studies for anticonvulsant activity are discussed.
A pilot study of the radio‐continuum emission from MASH planetary nebulae
Authors: Bojičić I.S. , Parker Q.A. , Frew D.J. , Vaughan A.E. , Filipović M.D. , Gunawardhana M.L.P.
Published: October 2015

We report an Australia Telescope Compact Array (ATCA) radio‐continuum observations of 26 planetary nebulae (PNe) at wavelengths of 3 and 6 cm. This sample of 26 PNe were taken from the Macquarie/AAO/Strasbourg Hα PNe (MASH) catalogue and previous lists. We investigate radio detection quality including measured and derived parameters for all detected or marginally detected PNe from this combined sample. Some 11 objects from the observed sample have been successfully detected and parametrized. Except for one, all detected PNe have very low radio surface brightnesses. We use a statistical distance scale method to calculate distances and ionised masses of the detected objects. Nebulae from this sample are found tobe large (>0.2 pc in diameter) and highly diluted which indicates old age. For 21 PNe from this sample we list integrated Hα fluxes and interstellar extinction coefficients, either taken from the literature or derived here from the Balmer decrement and radio to Hα ratio methods. Finally, our detected fraction of the MASH pilot sample is relatively low compared to the non‐MASH sub‐sample. We conclude that future radio surveys of the MASH sample must involve deeper observations with better uv coverage in order to increase the fraction of detected objects and improve the quality of the derived parameters (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparing life cycle energy andGHGemissions of bio‐basedPET, recycledPET,PLA, and man‐made cellulosics
Authors: Shen Li , Worrell Ernst , Patel Martin K
Published: October 2015

The purpose of this paper is to review the environmental profiles of petrochemicalPET, (partially) bio‐basedPET, recycledPET, and recycled (partially) bio‐basedPET, and compare them with other bio‐based materials, namelyPLA(polylactic acid, a bio‐based polyester) and man‐made cellulose fibers (cellulose fiber produced from wood pulp, i.e. Viscose, Modal and Tencel). Life cycle assessment (LCA) studies on polymers, fibers and bottles made from these materials are reviewed. Only non‐renewable energy use and greenhouse gas (GHG) emissions are considered. The scope is cradle to grave excluding the use phase. The results show that both recycled and bio‐based materials offer important environmental benefits over single‐use petrochemicalPET. Among the fourPETproduct systems studied, recycled (partially) bio‐basedPEThas the lowest impacts, followed by recycledPET, (partially) bio‐basedPET, and petrochemicalPET.PLAand man‐made cellulose fibers produced in an integrated plant have lower impacts than both petrochemicalPETand bio‐basedPET. The impacts of recycled products are strongly influenced by the choice of the allocation method applied to open‐loop recycling. © 2012 Society of Chemical Industry and John Wiley & Sons Ltd
Risk factors for the occurrence of spina bifida (a case–control study) and the prevalence rate of spina bifida in Japan
Authors: Kondo Atsuo , Morota Nobuhito , Ihara Satoshi , Saisu Takeshi , Inoue Katsumi , Shimokawa Shoko , Fujimaki Hiroya , Matsuo Keisuke , Shimosuka Yoichi , Watanabe Tomoyuki
Published: October 2015

BACKGROUND

The Japanese government recommended in 2000 that women planning pregnancy should take 400 μg of folic acid daily to decrease the risk of having an infant with spina bifida. We aimed to identify risk factors for the occurrence of spina bifida and to evaluate how the prevalence rate has altered over the past 3 decades.

METHODS

Subjects comprised 360 women who gave birth to spina bifida‐affected offspring and 2333 women who gave birth to offspring without spina bifida between 2001 and 2012. A self‐administered questionnaire was used to collect data, which were analyzed by multiple logistic regression models. The prevalence rate of spina bifida was obtained through data provided by international and domestic organizations.

RESULTS

Four variables were significantly associated with the increased risk of having newborns afflicted with spina bifida: not taking folic acid supplements (odds ratios [OR], 2.50; 95% confidence interval [CI], 1.72–3.64), presence of spina bifida patients within third‐degree relatives (OR, 4.26; 95% CI, 1.12–16.19), taking anti‐epileptic drugs without folic acid (OR, 20·20; 95% CI, 2.06–198.17), and low birth weight in the newborns ≤ 2500 g (OR, 4.21; 95% CI, 3.18–5.59). The prevalence rate of spina bifida has remained 5 to 6 per 10,000 total births and has not shown any decreasing trend over the past 11 years.

CONCLUSION

Four risk factors were identified among Japanese women. Because recommendations and information have not decreased the occurrence of spina bifida, the Japanese government should implement mandatory food fortification. Birth Defects Research (Part A) 97:610–615, 2013. © 2013 Wiley Periodicals Inc.
Effect of Himatanthus sucuuba in Maternal Reproductive Outcome and Fetal Anomaly Frequency in Rats
Authors: de Sousa Soares Thaigra , Damasceno Débora Cristina , Kempinas Wilma De Grava , Resende Flávia Mayara Campos , Correa dos Santos Maria Aparecida , Hiruma‐Lima Clélia Akiko , Volpato Gustavo Tadeu
Published: October 2015

The aim of this study was to evaluate the effect of Himatanthus sucuuba on the maternal reproductive outcome and fetal anomaly incidence in rats. Pregnant rats were randomly divided into three experimental groups as follows: Control = treated with water (vehicle), treated 250 = treated with H. sucuuba at dose 250 mg/kg, and treated 500 = treated with H. sucuuba at dose 500 mg/kg. The rats were orally treated, by gavage, with H. sucuuba or vehicle (water) during preimplantation and organogenic period (from gestational day 0–14). At day 21 of pregnancy, all rats were killed to obtain maternal–fetal data. The treatment with H. sucuuba at dose of 250 mg/kg caused reduction in placental efficiency and an increase preimplantation loss rate and placenta weight compared with the control. The treated 500 group presented a significant decrease in maternal weight gain, maternal weight gain minus gravid uterus weight, fetal weight, and placental efficiency compared with the control. In this group, there was a decrease in body weight at day 20 of pregnancy and metacarpus ossification and an increase in the preimplantation loss rate and skeletal anomalies compared with other groups. Himatanthus sucuuba extract caused intrauterine growth restriction, preimplantation loss, and developmental delay in the high doses tested
Zero‐inflated regression models for radiation‐induced chromosome aberration data: A comparative study
Authors: Oliveira María , Einbeck Jochen , Higueras Manuel , Ainsbury Elizabeth , Puig Pedro , Rothkamm Kai
Published: October 2015

Within the field of cytogenetic biodosimetry, Poisson regression is the classical approach for modeling the number of chromosome aberrations as a function of radiation dose. However, it is common to find data that exhibit overdispersion. In practice, the assumption of equidispersion may be violated due to unobserved heterogeneity in the cell population, which will render the variance of observed aberration counts larger than their mean, and/or the frequency of zero counts greater than expected for the Poisson distribution. This phenomenon is observable for both full‐ and partial‐body exposure, but more pronounced for the latter. In this work, different methodologies for analyzing cytogenetic chromosomal aberrations datasets are compared, with special focus on zero‐inflated Poisson and zero‐inflated negative binomial models. A score test for testing for zero inflation in Poisson regression models under the identity link is also developed.
Luminescence studies and infrared emission of erbium‐doped calcium zirconate phosphor
Authors: Tiwari Neha , Dubey Vikas
Published: October 2015

The near‐infrared‐to‐visible upconversion luminescence behaviour of Er3+‐doped CaZrO3 phosphor is discussed in this manuscript. The phosphor was prepared by a combustion synthesis technique that is suitable for less‐time‐taking techniques for nanophosphors. The starting materials used for sample preparation were Ca(NO3)2.4H2O, Zr(NO3)4 and Er(NO3)2, and urea was used as a fuel. The prepared sample was characterized by X‐ray diffraction (XRD). The surface morphology of prepared phosphor was determined by field emission gun scanning electron microscopy (FEGSEM). The functional group analysis was determined by Fourier transform infrared (FTIR) spectroscopy. All prepared phosphors with variable Er3+ concentrations (0.5–2.5 mol%) were studied by photoluminescence analysis. It was found that the excitation spectra of the prepared phosphor showed a sharp excitation peak centred at 980 nm. The emission spectra with variable Er3+ concentrations showed strong peaks in the 555 nm and 567 nm range, with a dominant peak at 555 nm due to the (2H11/2,4S3/2) transition and a weaker transition at 567 nm associated with 527 nm. Spectrophotometric determination of the peak was evaluated by the Commission Internationale de I'Eclairage (CIE) method These upconverted emissions were attributed to a two‐photon process. The excitation wavelength dependence of the upconverted luminescence, together with its time evolution after infrared pulsed excitation, suggested that energy transfer upconversion processes were responsible for the upconversion luminescence. The upconversion mechanisms were studied in detail through laser power dependence. Excited state absorption and energy transfer processes were discussed as possible upconversion mechanisms. The cross‐relaxation process in Er3+ was also investigated. Copyright © 2015 John Wiley & Sons, Ltd.