bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced waveguide effect for deep‐focus earthquakes in the subducting Pacific slab produced by a metastable olivine wedge
Authors: Furumura Takashi , Kennett Brian L. N. , Padhy Simanchal
Published: September 2016

Deep‐focus (>400 km) earthquakes in the subducting Pacific slab produce areas of anomalously large and lengthy shaking along the fore‐arc (Pacific ocean) side of northern Japan. This effect arises because the slab acts as an efficient waveguide for seismic waves from earthquakes at depth within the slab. The mechanism of such slab‐induced waveguide effect can be explained by efficient propagation of seismic waves in a cold and low‐attenuation (high Q) slab, with multiple forward scattering of high‐frequency (>1 Hz) waves in a quasi‐laminar stochastic waveguide. In this study, we demonstrate an additional mechanism to enhance the waveguide effect for deeper events, which is caused by reduction of the seismic wave speed in a metastable olivine wedge (MOW) in the core of the slab for depths between 400 and 600 km. We present evidence for the presence of the low‐wave speed MOW from analysis of broadband waveforms of deep‐focus earthquakes in the Pacific slab descending beneath the Sea of Japan. For events below 400 km depth, low‐frequency and slightly dispersed P and S phases arrive ahead of the most energetic high‐frequency direct phases. Numerical simulations of high‐frequency seismic wave propagation for both 2‐D and 3‐D heterogeneous subduction zone models demonstrate a strong waveguide effect from the MOW due to focusing of high‐frequency seismic waves toward the up‐dip direction in the slab. The presence of the metastable olivine in slabs allows the development of very large and lengthy ground motion for stations on the fore‐arc side of northern Japan in good agreement with the observations.
Cross‐shelf water exchange in the East China Sea as estimated by satellite altimetry and in situ hydrographic measurement
Authors: Ding Ruibin , Huang Daji , Xuan Jiliang , Mayer Bernhard , Zhou Feng , Pohlmann Thomas
Published: September 2016

Combining satellite altimetry and in situ hydrographic measurement, we estimated the cross‐shelf transport (CST) and its spatial and temporal variations across 200 m isobath in the East China Sea (ECS) from 1993 to 2014. The vertically integrated CST can be dynamically divided into three parts: surface Ekman transport, geostrophic transport, and bottom Ekman transport. The results show that the 22 year‐mean, sectionally integrated CST to be 1.7 ± 2.0 Sv (positive in the on‐shelf direction), comprised of bottom and surface Ekman transports of 2.7 ± 1.0 Sv and 0.6 ± 0.6 Sv, respectively, that are partially offset by a geostrophic transport of −1.5 ± 1.7 Sv. The sectionally integrated CST shows significantly high power at roughly annual period from 1999 to 2001, with lower power at intra‐annual period. The vertically integrated CST to the northeast of Taiwan is the main source of sectionally integrated CST. The vertically integrated CST also shows significant variations in the 6–15 month period band to the northeast of Taiwan as well. The temporal variations of the sectionally integrated and vertically integrated CST are both controlled primarily by geostrophic transport and modulated by bottom Ekman transport. In the upper 50 m, the geostrophic current to the northeast of Taiwan exhibits large mean and significant variability. The empirical orthogonal function analysis of vertical structure of geostrophic current shows two significant modes with strong annual signal. The first mode is associated with the migration of Kuroshio axis near Taiwan, while the second mode is associated with the variation of the meander of the Kuroshio to the northeast of Taiwan.
Chemical and dynamical impacts of stratospheric sudden warmings on Arctic ozone variability
Authors: Strahan S. E. , Douglass A. R. , Steenrod S. D.
Published: September 2016

We use the Global Modeling Initiative (GMI) chemistry and transport model with Modern‐Era Retrospective Analysis for Research and Applications (MERRA) meteorological fields to quantify heterogeneous chemical ozone loss in Arctic winters 2005–2015. Comparisons to Aura Microwave Limb Sounder N2O and O3 observations show the GMI simulation credibly represents the transport processes and net heterogeneous chemical loss necessary to simulate Arctic ozone. We find that the maximum seasonal ozone depletion varies linearly with the number of cold days and with wave driving (eddy heat flux) calculated from MERRA fields. We use this relationship and MERRA temperatures to estimate seasonal ozone loss from 1993 to 2004 when inorganic chlorine levels were in the same range as during the Aura period. Using these loss estimates and the observed March mean 63–90°N column O3, we quantify the sensitivity of the ozone dynamical resupply to wave driving, separating it from the sensitivity of ozone depletion to wave driving. The results show that about 2/3 of the deviation of the observed March Arctic O3 from an assumed climatological mean is due to variations in O3 resupply and 1/3 is due to depletion. Winters with a stratospheric sudden warming (SSW) before mid‐February have about 1/3 the depletion of winters without one and export less depletion to the midlatitudes. However, a larger effect on the spring midlatitude ozone comes from dynamical differences between warm and cold Arctic winters, which can mask or add to the impact of exported depletion.
Atmospheric structure favoring high sea surface temperatures in the western equatorial Pacific
Authors: Wirasatriya Anindya , Kawamura Hiroshi , Shimada Teruhisa , Hosoda Kohtaro
Published: September 2016

We investigated the atmospheric processes over high sea surface temperature called Hot Event (HE) in the western equatorial Pacific from climatological analysis and a case study of the HE which began on 28 May 2003 (hereafter, HE030528). Climatological analysis shows that during the development stage of HE, solar radiation inside the HE area is higher than its climatology and wind speed is lower than the decay stage. During the decay stage, strong westerly wind often occurs inside HE area. The case study of HE030528 shows that the suppressed convection above high SST area resulted from the deep convection from the northern and southern areas outside HE. The suppressed convection created a band‐shaped structure of low cloud cover along HE area increasing solar radiation during the development stage. Thus, the theory of “remote convection” was supported for the HE030528 formation mechanisms. The large sea level pressure gradient magnitude between the southern side of the terrain gap and the northern coast of the Solomon Islands, through which strong wind blew, indicated the role of land topography for the increase of wind speed during the decay of HE030528. Moreover, surface wind had an important role to influence the variability of solar radiation during the occurrence of HE030528 by controlling the water vapor supply in the upper troposphere through surface evaporation and surface convergence variation. Thus, surface wind was the key factor for HE030528 occurrence. The representativeness of HE030528 and the possible relation between HE and Madden‐Julian Oscillation are also discussed.
Percolation theory for solute transport in porous media: Geochemistry, geomorphology, and carbon cycling
Authors: Hunt Allen G. , Ghanbarian Behzad
Published: September 2016

Understanding the time‐dependent scaling of chemical weathering has been a significant research goal for over a decade. A percolation theoretical treatment of nonreactive solute transport that was previously shown compatible with the scaling of chemical weathering rates is here shown to be compatible with soil formation rates, and with C and N sequestration rates in the soil as well. In this theoretical framework, the percolation backbone fractal dimensionality, which generates the long‐time tail of the solute arrival time distribution, also predicts the scaling of the reaction rates, while laboratory proportionality to the fluid flow velocity translates to an analogous relevance of the vertical infiltration rate in the field. The predicted proportionality of solute transport to net infiltration generates simultaneously the variability in soil formation rates across 4 orders of magnitude of precipitation and 12 orders of magnitude of time scales.
Disordered Proteins
Authors: DeForte Shelly , Uversky Vladimir N
Published: September 2016

Intrinsically disordered proteins (IDPs) and disordered protein regions (IDPRs) do not have a specific three‐dimensional (3D) structure in their unbound states under physiological conditions, existing instead as dynamic structural ensembles. There are also subtler categories of disorder, such as conditional (or dormant) disorder and partial disorder. Both the ability of a protein/region to fold and the predisposition to stay intrinsically disordered are encoded in the amino acid sequence. Structurally, IDPs/IDPRs are characterised by high spatiotemporal heterogeneity. It is important to remember, however, that although structure and disorder are often treated as binary states, they actually sit on a structural continuum. Functionally, IDPs/IDPRs are often characterised by the ability to multitask and be promiscuous binders. The field of unstructural biology has arisen to explain proteins that fall outside of the classical structure–function paradigm. A major goal in the coming years will be to understand sequence‐to‐function relationships for disordered proteins.

Key Concepts

Many biologically important protein regions fail to form specific three‐dimensional (3D) structures in their unbound states under physiological conditions.

Amino acid sequences of these intrinsically disordered proteins (IDPs) are noticeably different from sequences of ordered proteins and reliable predictors can be developed to distinguish the tendency of a protein to be structured or disordered.

IDPs are highly abundant in nature and have numerous functions that complement the functional repertoire of ordered proteins.

IDPs are characterised by high structural heterogeneity, and there is a structural continuum, with highly ordered proteins on one end and highly disordered proteins on the other.

IDPs/IDPRs are commonly found in various human diseases where they often play crucial roles in pathogenesis.

IDPs are crucial constituents of various membraneless organelles abundantly found in the cytoplasm and nucleoplasm of eukaryotic cells.
Cystic Fibrosis: Modifier Genes
Authors: Saferali Aabida , Turvey Stuart E , Sandford Andrew J
Published: September 2016

Cystic fibrosis (CF) is a rare autosomal recessive disease that causes early death through respiratory failure. Although it is known that CF is caused by mutations in the cystic fibrosis transmembrane conductance regulator gene (
CFTR
) it has been found that other genetic factors make a large contribution to the severity of lung disease as well as several other CF traits. Several large‐scale genomewide association studies have been performed for CF lung disease severity, body mass index/nutritional status, CF‐related diabetes, meconium ileus and age of onset of chronic
Pseudomonas aeruginosa
infection. Several genes have been identified that modulate CF disease severity. In particular, apical membrane constituents have been associated with several phenotypes including lung function, meconium ileus and age of onset of
P. aeruginosa
infection. The results of these studies have provided insight into the pathophysiology of CF and have identified novel therapeutic targets.

Key Concepts

Lung disease severity in CF, along with several other CF traits, is influenced by non‐
CFTR
genetic factors.

Genomewide association studies and linkage analysis have identified several genes associated with CF severity.

Meta‐analysis of several patient cohorts is required to identify reproducible findings.

Apical membrane constituents, in particular
SLC6A14
,
SLC26A9
and
SLC9A3
, are a class of molecules associated with several CF phenotypes.

Exome‐wide sequencing can be used as an alternative approach to discover novel modifier genes.
Phloem Long‐Distance Trafficking of
RNAs
and Proteins
Authors: Xoconostle‐Cázares Beatriz , Martínez‐Navarro Angélica C , Ruiz‐Medrano Roberto
Published: September 2016

The vascular tissue has been essential for the evolutionary radiation of land plants, and has allowed them to colonise a wide range of habitats. The phloem is involved in the distribution of fixed carbon throughout the whole plant. The concept of this tissue as a central distributor of signals that regulate plant development and responses to environmental cues has emerged recently. Indeed, several phenomena, such as post‐transcriptional gene silencing, flowering and tuber induction, as well as systemic acquired resistance to pathogens rely on signals, originating in source leaves, and transported via the phloem to systemic tissues. Considering that the phloem translocation stream contains a large array of macromolecules. Given that the functional phloem consists of interconnected enucleate cells, the sieve elements (SEs), the majority of proteins and ribonucleic acids (RNAs) found in phloem sap exudates must originate from the adjoining companion cell (CC). While several proteins play a role in the maintenance of the SEs, it is possible that several species of proteins and RNAs function in long‐distance signalling. In this article the current state of the art of this subject is described, as well as perspectives and possible applications for crop improvement.

Key Concepts

The vascular tissue consists of xylem and phloem.

The xylem is composed of vessels that are dead cells upon maturity that transport mineral nutrients from roots to shoots.

The phloem is composed of vessels formed from enucleated living cells involved in the transport of fixed carbon from photosynthetic to heterotrophic organs.

The phloem is involved in the delivery of signals that control development as well as responses to external stimuli, such as defence response, post‐transcriptional gene silencing and response to phosphate starvation.

Viruses and viroids are transported through the phloem during systemic infection.

These probably take advantage of a system enabling long‐distance transport of endogenous proteins and RNAs.

The phloem translocation stream contains a wide variety of proteins and RNAs, some of which appear to have a signalling function.

RNA and protein exchange can occur between plant pathogenic fungi and parasitic plants and their hosts.

Knowledge of this RNA and protein phloem transport system can have applications for crop improvement.
Plant Polycomb‐Group Proteins: Epigenetic Regulators of Development
Authors: Perera Pumi , Goodrich Justin
Published: September 2016

Although all cells in a multicellular organism contain the same set of genes, the spatiotemporal expression of these genes needs to be dynamically regulated for proper development (i.e. morphogenesis and life cycle transitions) to take place. Epigenetic mechanisms (i.e. heritable but reversible changes to chromatin) are important to maintain such gene expression patterns. Polycomb‐group proteins are evolutionarily conserved epigenetic regulators that function – via epigenetic marks such as histone modifications and alterations to chromatin structure – to maintain the repression of developmentally important genes so that these genes are expressed appropriately. Although they maintain specific patterns of gene repression, Polycomb‐group proteins are ubiquitously expressed. How their activity is regulated is a largely unexplored area but recent research in both metazoans and plants suggests myriad methods of regulation, including control of mRNA (messenger ribonucleic acid) and protein abundance and stability, post‐translational modifications and interactions with proteins and noncoding
RNAs
.

Key Concepts

Chromatin comprises of DNA folded up to form higher order structures, the basic unit of which is a nucleosome, which consists of DNA wrapped around histone proteins.

Epigenetic changes can regulate transcription and include alterations to DNA packaging and covalent modifications of histones or DNA.

Epigenetic changes are important for development because they can cause gene expression patterns that are heritable through cell divisions but more easily reversible than changes to DNA sequence.

Polycomb‐group proteins are conserved epigenetic regulators that maintain the repression of developmentally important genes in plants and animals.

Polycomb‐group proteins form various complexes that can modify chromatin (by adding epigenetic marks such as H3K27me3 and H2Aub to histones and altering chromatin structure and accessibility).

Polycomb‐group proteins are expressed ubiquitously and therefore need to be finely regulated to allow for specific and dynamic repression of their target genes.

Polycomb‐group protein levels or activity may be regulated by post‐translational modifications and controlled degradation.

Polycomb‐group proteins associate with other proteins or long noncoding RNAs that may regulate their activity or recruitment to specific targets.

Polycomb‐group repression can be reversed by antagonistic transcriptional activators and removers of Polycomb‐group epigenetic marks, some of which are part of the evolutionarily conserved trithorax‐group of proteins.
Genetics of Early Miscarriages
Authors: Vaiman Daniel
Published: September 2016

Early miscarriage or early pregnancy loss (EPL) is defined by an embryonic foetal loss occurring before 13 weeks of gestation. In this article, we focus on the genetics of this complex human disease from studies of human patients, sometimes including foetal losses occurring before 20 weeks. Most of the mouse studies on EPL are based on gene invalidation experiments having much wider and pleiotropic effects than a mere defect of implantation or placental development, and therefore they will not be analyzed here. In addition, many good reviews are already available on gene polymorphisms relevant to early miscarriage and are only briefly summarised here. We develop more in‐depth aspects connected to microRNA and copy number variations with EPL, issues that have been much less reviewed in the past.

Key Concepts

Early pregnancy loss is a complex multifactorial disease, leading to embryo loss in an estimated >70% of the fertilisation events in humans.

Besides chromosome anomalies, detected by cytogenetics or CGH arrays (array‐based comparative genomic hybridisation), gene variants are associated with an increased risk of pregnancy loss. These genes may be regulators of immune response including cytokines, modulators of the coagulation cascade, equilibrators of the oxidative stress or, rarely, genes involved in chromosome segregation at meiosis or mitosis. Other genes may be found by genome‐wide association studies.

Recent novel studies are developing on the impact of epigenetic regulators (essentially microRNAs) on miscarriages. These can be relevant markers to categorise gene expression deregulation in pregnancy losses.
The Nuclear Envelope Protein Emerin and Its Interacting Proteins
Authors: Collins Carol M , Nee Kimbre A , Holaska James M
Published: September 2016

Emerin is a highly conserved and ubiquitously expressed inner nuclear membrane protein of the nuclear envelope. Mutations in the gene encoding emerin cause X‐linked Emery–Dreifuss muscular dystrophy (EDMD), a tissue‐specific, progressive disease that selectively affects skeletal muscle, the cardiac conduction system and tendons. Emerin regulates a number of nuclear functions through interactions with many different binding partners. These emerin‐regulated cellular functions include regulating genomic architecture, maintaining nuclear structure and regulating gene transcription in response to mechanical and chemical signals. Emerin regulation of these activities is important for controlling the coordinated temporal expression of myogenic differentiation genes during skeletal muscle regeneration. This article focuses on the mechanisms by which emerin regulates chromatin architecture and gene transcription and how these mechanisms may function in the development of EDMD.

Key Concepts

Proteins of the nuclear lamina are important for chromatin architecture and regulation of gene transcription.

Emerin is a nuclear lamina protein that plays key roles in regulating chromatin organisation and gene expression.

Emerin regulates the coordinated temporal expression of myogenic differentiation genes.

Emerin is required for proper myogenic differentiation.

Loss of emerin causes Emery–Dreifuss muscular dystrophy.
Reverse Signalling
Authors: Ross Emily F , Ali Maria F , Woo Laura A , Chadwick Sean R , Lee Eunji , Sangston Ryan M , Sood Chhavi , Zhang Qi , Zhang Xiaomu , Deppmann Christopher D
Published: September 2016

Cellular signal transduction is defined as the conversion of an extracellular signal to a response within a cell. Commonly referred to as forward signalling, this extracellular signal often comes in the form of a soluble ligand that binds to a membrane‐spanning receptor. However, many ligands or their precursors are also transmembrane or membrane associated. It is now appreciated that these ligands may also act as receptors in a process referred to as reverse signalling. There is a growing body of evidence that reverse signalling occurs for several classes of ligands including: ephrins, semaphorins, interleukins, tumour necrosis factor family members and Notch‐associated ligands. This type of signalling has been linked to immune responses, axon guidance, cell proliferation and differentiation. Here we review reverse signalling of ligands categorised by how they associate with the membrane: transmembrane type 1 (TM1), transmembrane type 2 (TM2), or GPI‐linked. Within this structure we will emphasize the physiological and pathological roles of reverse signaling.

Key Concepts

Ligand classes that possess the ability to reverse signal include, but are not limited to, members of the tumour necrosis factor superfamily (TNFSF), ephrin family, semaphorin family, interleukin family and Notch‐associated ligands.

These ligands can be categorized into the following subgroups: transmembrane type 1 (TM1), transmembrane type 2 (TM2), and GPI‐linked.

Ligands can reverse signal by directly recruiting adaptor or effector proteins, acting in concert with coreceptors or by liberation of the intracellular domain to influence transcription.

Reverse signalling has been shown to be involved in processes including axon guidance, tissue development and immune responses.

Ectopic regulation of reverse signalling is associated with a range of pathologies including cancer, developmental defects and osteoporosis.
Micellar Nanoreactors
Authors: Scarso Alessandro
Published: September 2016

All chemical disciplines, primarily homogeneous catalysis, are experiencing a great revolution owing to the emerging and increasingly stringent requirements represented by green chemistry principles. Replacement of traditional organic solvents with water is nowadays a viable solution where the use surfactants for the formation of nanometric micelles in water as a place to carry out reactions plays a key role. The use of micelles in catalysis is a simple and economic approach to circumvent solubilization problems in water. Moreover, the confinement of the catalyst in several cases enables simple catalyst recycling together with facile product isolation by means of extraction with an apolar solvent in limited amounts. Micelles operate as nanometric reactors where substrates and catalysts are confined and this proves to favor catalytic activity and, more importantly, selectivity at all levels for a wide range of chemical transformations, also in the stereoselective manner, in most cases with better performance compared to traditional organic solvents. In this contribution, after a brief introduction on surfactants, their aggregation properties in water, and micelle formation, a wide selection of catalytic reactions in micellar conditions is discussed with the aim of making this approach to homogeneous catalysis more familiar for students and colleagues in the academia as well as in chemical companies.
Ionic Liquids: Applications by Computational Design
Authors: Karunanithi Arunprakash T. , Farahipour Reza , Dilmurat Kamila
Published: September 2016

Ionic liquids (ILs) are molten salts that exist as liquids at relatively low temperatures and have unique properties. The most exciting aspect of ILs is the opportunity to fine‐tune their physicochemical and thermodynamic properties based on careful selection of cations and anions. There are no limits to the number of possible IL combinations as there are a large number of cation and anion variants that can be combined together to form binary and ternary ionic liquids. To effectively identify task‐specific ILs, we propose a computer‐aided ionic liquid design (CAILD) approach with an aim to screen thousands of IL combinations to identify optimal candidates for a given application. We present a novel approach that uses the concept of group contribution modeling to predict surface charge density of ionic liquid structures generated by DFT calculations, which is further combined with COSMO‐SAC model to enable thermodynamic property predictions of systems involving ionic liquids without any need for experimental data. This allows us to consider more diverse set of ionic liquids for design purposes. In this chapter, we summarize these methodological advancements and present two proof‐of‐concept case studies.
Toxicity Assessment of Molecular Rhenium(VII) Epoxidation Catalysts
Authors: Cokoja Mirza , Markiewicz Marta , Stolte Stefan , Kühn Fritz E.
Published: September 2016

Methyltrioxorhenium(VII) (MTO) is a highly efficient epoxidation catalyst with a broad substrate scope. Evaluation of its hazard potential shows that it is able to cause short‐term (eco)toxicological effects with indications for genotoxicity. However, under catalytic conditions, MTO (and its catalytically active derivatives) decomposes slowly to perrhenates, displaying low toxicity. In aqueous solutions, particularly in the presence of bases, this decomposition is rather quick. Accordingly, MTO is not long‐time stable in an aqueous environment, yielding far less toxic decomposition products. Perrhenate‐containing ionic liquids are also of low toxicity (at least with respect to the rhenium‐containing anion); their epoxidation activity, however, is ‐ so far—no match for MTO. The latter molecule, however, due to its limited stability in aqueous environments and the low toxicity of its decomposition products, combined with its high catalytic activity and selectivity may be regarded as a useful catalyst for practical applications under controlled and safe reaction conditions.
Solvent Systems for Sustainable Chemistry
Authors: Kerton Francesca M.
Published: September 2016

Reduced use of volatile organic compounds as solvents in chemical processes is highly desirable from a sustainability point of view. This is because many conventional organic solvents have high vapor pressures, which can lead to hazards including low flash points, high flammability, toxicity, and atmospheric pollution. In order to make decisions regarding solvent use in a chemical process, it is important to evaluate the options available both from a chemical point of view and also with regards to the environment and safety. The typical physicochemical properties and parameters that need to be considered are briefly described. An overview of the environmental, health, and safety criteria used to assess all solvent systems (traditional and environmentally friendly) is provided. The concept of life‐cycle assessment when applied to solvents in either a quantitative or a qualitative way is introduced. Guidance provided by industrial users of solvents, especially the pharmaceutical industry, is highlighted. A range of sustainable solvent systems are described in this chapter. These include: water, supercritical carbon dioxide, carbon dioxide‐expanded liquids, solvents of switchable polarity and volatility, room temperature ionic liquids and deep eutectic solvents, bio‐derived solvents (e.g., 2‐methyltetrahydrofuran and glycerol), and solvent‐free systems. Their advantages, disadvantages, and properties are discussed, and examples of chemistries performed in them are given. Biphasic systems based on sustainable solvents and aimed at allowing their more efficient use and potential catalyst recycling are described. These include water/bio‐derived solvent, supercritical carbon dioxide/water, and supercritical carbon dioxide/ionic liquid systems.
Sustainable Synthesis of Fine Chemicals from Aliphatic Nitro Compounds
Authors: Ballini Roberto , Palmieri Alessandro
Published: September 2016

The demands of modern society for new functional chemical entities have driven the development of novel methods that are revolutionizing the way we think, plan, and optimize chemical processes. Chemical industries, in general, use a large volume of organic solvents and catalysts in their manufacturing processes. However, the toxic and volatile nature of many organic solvents have posed serious threats to the environment. Hence, industries are finding it very difficult to meet the standards set by pollution regulatory boards while using traditional methods. Thus, redesign of chemical processes for reducing or avoiding hazardous organic solvents and toxic catalysts is highly desirable. In 1998, Anastas and Warner teamed up to write the best‐selling and most cited book in the field of Green Chemistry, “Green Chemistry: Theory and Practice”, which explicated the 12 principles of Green Chemistry. The application of many of these principles could be strongly favored by the right choice of the starting material in a synthetic process, in particular those such as nitroalkanes that show high chemical versatility. This article deals with this issue and highlights some representative examples on the application of nitroalkanes as key starting molecules for the sustainable synthesis of fine chemicals via (i) one‐pot synthetic processes, (ii) reactions in aqueous medium, and (iii) solvent‐free reactions (SolFR).
Sustainable Surfactants Based on Amino Acids
Authors: Pérez Lourdes , Infante M. Rosa , Pinazo Aurora
Published: September 2016

Surfactants are chemical products consumed in large quantities every day on a worldwide scale. In recent years, environmental concerns and regulatory pressure have emerged as the driving forces to partly replace petrochemical‐based surfactants with those based on naturally occurring renewable sources. The hope that such surfactants would be biodegradable and biocompatible has provided strong incentive for the research of less irritant and less toxic consumer‐friendly surfactants. Biodegradability, low toxicity, and antimicrobial activity are properties common to surfactants derived from amino acids. In this chapter we offer an overview of the synthesis methods and properties published in the literature concerning four families of amino acid based surfactants: single chain, amino acid based surfactants, diacyl‐glycerolipid conjugates, gemini surfactants from amino acids, and polydispersed lipopeptides from a mixture of amino acids. Whenever present in the source material, specific applications are described.
Dimethylcarbonate for the Catalytic Upgrading of Amines and Bio‐Based Derivatives
Authors: Selva Maurizio , Perosa Alvise , Guidi Sandro , Cattelan Lisa
Published: September 2016

An archetype of a green and sustainable strategy for the catalytic upgrading of both anilines and bio‐based derivatives including glycerol acetals,
p
‐coumaryl‐like alcohols, and lactones can be devised by the use of dimethyl carbonate (DMC). In the presence of different heterogeneous catalysts such as alkaline carbonates and alkali metal‐exchanged faujasites, DMC allows quantitative mono‐N‐methylation and O‐methylation processes with excellent selectivity up to 99% and no by‐products except for methanol (recyclable to the synthesis of DMC) and CO
2
. Also, selective transesterifications of DMC with glycerol acetals and lactones can be achieved under thermal or catalytic conditions. The mechanism of such reactions has been formulated based on the steric requisites and the amphoteric nature of faujasites, the combined effect of the temperature and base catalysts, and the ambident electrophilic reactivity of DMC. Overall, methylations and methoxycarbonylations mediated by DMC are not only more selective but far safer than conventional procedures involving noxious phosgene and methyl halides or dimethyl sulfate.
Water Treatment by Electrocoagulation
Authors: Kuokkanen Ville V.
Published: September 2016

Electrocoagulation (EC) is an emerging technology that is applied in water and wastewater treatment, which combines the functions and advantages of conventional chemical coagulation (CC), flotation, and electrochemistry. Although EC has been known for over a century, it is currently under a strongly renewed global research, and has also gained industrial interest. This is mainly due to its cost‐, material‐, and eco‐efficiency. Furthermore, environmental regulations regarding wastewater discharge are becoming increasingly stringent. Therefore, it has become a necessity to develop more effective alternative and automatic treatment methods for water purification and/or enhance the operation of the existing, more classical methods. As a result, the range of feasible EC applications is expanding. Innovations in this field have also been made recently. At its simplest, an EC system may consist of two plate electrodes, an anode and a cathode, and a direct current power source. In short, EC is based on coagulation brought about by aluminum or iron derived (in situ) from electrochemical dissolution of the anode metal, which is used as the so‐called sacrificial anode. Simultaneously with the anodic reaction, hydrogen gas bubbles are generated at the cathode surface, promoting electroflotation (EF). Furthermore, in an EC system, a variety of minor side reactions may take place. EC also neutralizes solution pH, mainly due to cathodic OH
−
ion generation. This is converse to CC. Since CC may naturally be seen as the main competitor to EC, comparison between the two technologies is inevitable. EC has multiple advantages over CC. Firstly, these include economic aspects: EC is energy‐efficient, and its running costs as well as investment costs in establishing EC systems are low due to their small size and simplicity. Second, since no chemicals are needed in EC, secondary pollution is avoided, which makes EC “a green technology”. Third, EC is also readily automated and hybridizable with other methods, and produces low amounts of sludge of a better quality than CC sludge. The most obvious disadvantage of EC is the need to periodically replace the electrodes, along with the need for sufficient water conductivity. Electrode passivation may also occur.
Role of Mixed Metal Oxides in Heterogeneous Catalysis
Authors: Burange Anand S. , Gawande Manoj B.
Published: September 2016

In this article, we include numerous types of mixed metal oxides (MMOs) including their properties and catalytic applications for several types of reactions, focusing on their active sites (acidic and basic). Owing to the acid–base and redox properties of MMOs, they establish a largest family of catalysts in heterogeneous catalysis. Generally, in most of the examples, MMOs have superior properties in terms of acidic or basic sites and surface area than single oxide. In addition, some examples of mixed metal ratio are also discussed on specific catalytic applications.
Helping and hurting others: Person and situation effects on aggressive and prosocial behavior as assessed by the Tangram task
Authors: Saleem Muniba , Barlett Christopher P. , Anderson Craig A. , Hawkins Ian
Published: September 2016

The Tangram Help/Hurt Task is a laboratory‐based measure designed to simultaneously assess helpful and hurtful behavior. Across five studies we provide evidence that further establishes the convergent and discriminant validity of the Tangram Help/Hurt Task. Cross‐sectional and meta‐analytic evidence finds consistently significant associations between helpful and hurtful scores on the Tangram Task and prosocial and aggressive personality traits. Experimental evidence reveals that situational primes known to induce aggressive and prosocial behavior significantly influence helpful and hurtful scores on the Tangram Help/Hurt Task. Additionally, motivation items in all studies indicate that tangram choices are indeed associated with intent of helping and hurting. We discuss the advantages and limitations of the Tangram Help/Hurt Task relative to established measures of helpful and hurtful behavior. Aggr. Behav. 43:133–146, 2017. © 2016 Wiley Periodicals, Inc.
Tandem Chemoselective 1,2‐/1,4‐Migration of the Thio Group in Keto Thioesters: An Efficient Approach to Substituted Butenolides
Authors: Mal Kanchan , Naskar Sandip , Sen Shovan Kumar , Natarajan Ramalingam , Das Indrajit
Published: September 2016

We report herein an efficient and mechanistically unique tandem chemoselective 1,2‐/1,4‐migration of the thio group in keto thioesters that provides substituted butenolides in moderate to excellent yields. Thus, α‐keto thioesters in the presence of stabilized phosphonate carbanions undergo tandem 1,2‐sulfur migration; whereas 1,4‐migration of the thio group has been achieved with the same thioesters after the treatment with Wittig reagents followed by BF3⋅OEt2‐catalyzed tandem reaction. The crossover experiments and the isolation of intermediates reveal a stepwise mechanism for both of these transformations.

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Single‐Biocatalyst Synthesis of Enantiopure d‐Arylalanines Exploiting an Engineered d‐Amino Acid Dehydrogenase
Authors: Parmeggiani Fabio , Ahmed Syed T. , Thompson Matthew P. , Weise Nicholas J. , Galman James L. , Gahloth Deepankar , Dunstan Mark S. , Leys David , Turner Nicholas J.
Published: September 2016

A practical and efficient biocatalytic synthesis of aromatic d‐amino acids has been developed, based on the reductive amination of the corresponding α‐keto acids via a recombinant whole cell system composed of an engineered dehydrogenase and cofactor recycling apparatus. The reaction was shown to give excellent enantioselectivity (≥98%) and good yields at the preparative scale across a broad range of substrates. Additionally, the structure of the variant enzyme was solved to allow rationalisation of the observed reaction rates. The engineered whole cell catalyst was also used to mediate the production of d‐phenylalanine derivatives from racemic mixtures and cheaper l‐amino acids by combining it with an enantiocomplementary deaminase.

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Mutations in idiopathic cytopenia of undetermined significance assist diagnostics and correlate to dysplastic changes
Authors: Hansen Jakob Werner , Westman Maj Karoline , Sjö Lene Dissing , Saft Leonie , Kristensen Lasse Sommer , Ørskov Andreas Due , Treppendahl Marianne , Andersen Mette Klarskov , Grønbæk Kirsten
Published: September 2016

Cytopenia is common in the elderly population and etiology may be difficult to assess. Here, we investigated the occurrence of mutations in patients with idiopathic cytopenia of undetermined significance and the usefulness in improving diagnostics. We included 60 patients with persistent cytopenia > 6 months without definite diagnosis of hematological neoplasm after routine assessment. Bone marrow material underwent a blinded morphology review and DNA was sequenced with a targeted 20 gene panel representing the most commonly mutated genes in myelodysplastic syndrome. Thirty seven (62%) patients carried at least one mutation at inclusion, and of these 95% carried a mutation in TET2, ASXL1, SRSF2, or DNMT3A. The most commonly mutated gene was TET2 observed in 43% of all patients. During one to eight years follow‐up seven patients progressed to a myeloid neoplasm and six of these had a detectable mutation at study entry. Median time to progression was 53 months (range 10–78), and at time of progression each patient had at least two mutations detected. Mutations in TP53 and NRAS were not present in patients at inclusion, but identified as secondary hits triggering progression. The morphology review was concordant in 68% of all cases, and 93% of the cases reclassified into the group “highly suspicious for MDS” had a mutation. All patients who had a concordant review “highly suspicious for MDS” had at least two mutations detected. Overall, we show that morphology examination is challenging in this heterogeneous group and targeted sequencing helps identify patients at risk of progression. Am. J. Hematol. 91:1234–1238, 2016. © 2016 Wiley Periodicals, Inc.
The presentation and outcomes of mucosal melanoma in 695 patients
Authors: Konuthula Neeraja , Khan Mohemmed N. , Parasher Arjun , Del Signore Anthony , Genden Eric M. , Govindaraj Satish , Iloreta Alfred M.
Published: September 2016

Background

Most data on sinonasal mucosal melanoma come from small institutional studies, and therefore optimal treatment methods are not well understood. The purpose of this study was to analyze the association between treatment and survival in sinonasal mucosal melanoma.

Methods

Six hundred ninety–five patients diagnosed with sinonasal mucosal melanoma between 2004 and 2010 were identified from the National Cancer Data Base. Treatment modalities and overall survival rates were determined.

Results

The 5–year overall survival was 21.7%, with a mean survival of 38.4 ± 1.7 months. The majority of patients were treated with surgery alone (31.5%) or surgery with adjuvant radiotherapy (41.4%). There was no statistical difference between survival with surgery alone and surgery with adjuvant radiation therapy (25.1% vs 25.1%, p = 0.93). Between the surgery and surgery–with–adjuvant–therapy groups, there was no difference in the number of patients with positive margins (p = 0.54), regional lymph node metastases at diagnosis (p = 0.55), morbidity scores (p = 0.58), insurance status (p = 0.13), age > 60 years (p = 0.24), or treatment at academic centers (p = 0.12).

Conclusions

Based on this large review of patients with sinonasal mucosal melanoma, adjuvant radiation therapy may not provide a survival benefit as patients tended to do poorly regardless of adjuvant radiation status.
Gold‐katalysierte Synthese von Chinolinen aus Propargylsilylethern und Anthranilen über die Umpolung eines Goldcarben‐Kohlenstoffatoms
Authors: Jin Hongming , Tian Bin , Song Xinlong , Xie Jin , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K.
Published: September 2016

Die Gold‐katalysierte Kaskaden‐Anellierung propargylischer Silylether mit Anthranilen verläuft sequenziell über eine Ringöffnung/1,2‐H‐Verschiebung/Protodesaurierung/Mukaiyama‐Aldol‐Cyclisierung. Dieses Protokoll bietet einen regiospezifischen und modularen Zugang zu 2‐Aminochinolinen und anderen Chinolinderivaten unter milden Bedingungen bei guter Kompatibilität mit funktionellen Gruppen. Die Reaktionen gelingen im Gramm‐Maßstab, was den präparativen Nutzen der Methode unterstreicht. Die Vielseitigkeit der erhaltenen Molekülgerüste wurde anhand nützlicher Folgereaktionen demonstriert.
3,6‐Dinitropyrazolo[4,3‐c]pyrazole‐Based Multipurpose Energetic Materials through Versatile N‐Functionalization Strategies
Authors: Yin Ping , Zhang Jiaheng , Mitchell Lauren A. , Parrish Damon A. , Shreeve Jean'ne M.
Published: September 2016

A family of 3,6‐dinitropyrazolo[4,3‐c]pyrazole‐based energetic compounds was synthesized by using versatile N‐functionalization strategies. Subsequently, nine ionic derivatives of the N,N′‐(3,6‐dinitropyrazolo[4,3‐c]pyrazole‐1,4‐diyl)dinitramidate anion were prepared by acid‐base reactions and fully characterized by infrared, multinuclear NMR spectra, and elemental analysis. The structures of four of these compounds were further confirmed by single‐crystal X‐ray diffraction. Based on their different physical and detonation properties, these compounds exhibit promising potential as modern energetic materials and can be variously classified as green primary explosives, high‐performance secondary explosives, fuel‐rich propellants, and propellant oxidizers.
Poly(ionic liquid)‐Mediated Morphogenesis of Bismuth Sulfide with a Tunable Band Gap and Enhanced Electrocatalytic Properties
Authors: Gao Min‐Rui , Yu Shu‐Hong , Yuan Jiayin , Zhang Weiyi , Antonietti Markus
Published: September 2016

Conventional polymer additives have a substantial impact on synthetic inorganic chemistry, but critical shortcomings remain; for example, low solubility in organic solvents and potential thermodynamic aggregates. Poly(ionic liquid)s have now been used as efficient additives that enable a high level control of bismuth sulfide crystals with significant size and morphological diversities. The bismuth sulfides exhibit tunable band structure as a result of the quantum size effects. Moreover, poly(ionic liquid)s are able to couple with as‐synthesized bismuth sulfides chemically and endow a modified surface electronic structure, which allows resultant products to possess outstanding electrocatalytic performance for water oxidation, although its commercial counterpart is catalytically inert.
Cycloaddition of P−C Single Bonds: Stereoselective Formation of Benzo‐1,3,6,2‐trioxaphosphepine Complexes via a Ditopic van der Waals Complex
Authors: Malik Payal , Espinosa Ferao Arturo , Schnakenburg Gregor , Streubel Rainer
Published: September 2016

While phosphaalkenes and phosphanes are known to participate in [4+n] cycloaddition reactions, P−C single bonds are inert in this respect. Herein, reactions of oxaphosphirane complexes with tetrachloro‐ortho‐benzoquinone are presented that reveal a stereoselective reaction of the endocyclic P−C bond to afford benzo‐1,3,6,2‐trioxaphosphepine complexes. High‐level DFT calculations provide evidence that the final product is derived from a sequence of three consecutive steps involving a ditopic van der Waals complex.
An Ultrasensitive Cyclization‐Based Fluorescent Probe for Imaging Native HOBr in Live Cells and Zebrafish
Authors: Xu Kehua , Luan Dongrui , Wang Xiaoting , Hu Bo , Liu Xiaojun , Kong Fanpeng , Tang Bo
Published: September 2016

Bromine has been reported recently as being the 28th essential element for human health. HOBr, which is generated in vivo from bromide, is a required factor in the formation of sulfilimine crosslinks in collagen IV. However, to date, no method for the specific detection of native HOBr in vivo has been reported. Herein, we develop a simple small molecular probe for imaging HOBr based on a specific cyclization catalyzed by HOBr. The probe can be easily synthesized in high yield through a Suzuki cross‐coupling reaction. The probe exhibits ultrahigh sensitivity at the picomole level, in addition to specificity for HOBr and real‐time response. Importantly, without Br− stimulation, this probe reports native HOBr levels in HepG2 cells. Thus, the probe is a promising new tool for imaging endogenous HOBr and may provide a means for finding new physiological functions of HOBr in living organisms.
Distributed Consensus of Multi‐Agent Networks Via Event‐Triggered Pinning Control
Authors: Liu Dan , Hu Aihua , Zhao Dan
Published: September 2016

This paper is concerned with distributed consensus between two multi‐agent networks with the same topology structure. Considering one network as the leaders' network and the other one as the followers' network, a new event‐triggered pinning control scheme is proposed to realize distributed consensus between these two networks. By utilizing the graph theory and Lyapunov functional method, consensus criteria are derived in the form of linear matrix inequalities. Moreover, distributed consensus of multi‐agent networks with Lipschitz nonlinear dynamics is also discussed. Numerical simulations are provided to demonstrate the effectiveness of the theoretical analysis.