bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genome Evolution in Plants
Authors: Marchant D Blaine , Soltis Douglas E , Soltis Pamela S 
Published: September 2016

Abstract

The genomes of land plants vary dramatically in size and chromosome number, and ongoing studies are clarifying the processes that shape their composition, structure and function. Polyploidy produces an entirely duplicated genome where the processes of nonfunctionalisation, subfunctionalisation and neofunctionalisation occur at individual loci or across entire genetic pathways, with both short‐ and long‐term effects. Transposable elements mould and alter genomes via a wide array of direct and indirect mechanisms extending well beyond their capacity to move throughout genomes. Horizontal gene transfer affects genome evolution of a lineage by incorporating novel genetic material from a separate lineage. Alternative splicing results in the inclusion and exclusion of a gene's exons and introns in processed messenger ribonucleic acid, altering the amino acid sequence and increasing an organism's protein repertoire without altering gene number. The impacts of these processes on plant genome evolution are just beginning to emerge as nonmodel genomes are sequenced.

Key Concepts

Polyploidy, or whole‐genome duplication, can result in immediate genomic and genetic variation.

Gene retention or loss following polyploidy may depend on gene function and expression levels.

Transposable elements can actively or passively alter genome composition and genetic networks via a variety of processes.

Horizontal gene transfer has been most commonly found in plant mitochondrial genomes, although more cases are being found in nuclear genomes.

Alternative splicing can provide multiple gene products from a single nucleotide sequence.

The conservation and evolutionary significance of alternative splicing patterns are just beginning to be elucidated in plants.

Genome size in plants varies from among the smallest eukaryotic genomes to the largest eukaryotic genomes yet determined.
Rare Earth Recycling fromNdFeB
Authors: Hua Zhongsheng 
Published: September 2016

AbstractRare earths are becoming increasingly important in modern industry due to their essential role in permanent magnets, nickel metal‐hydride batteries, lamp phosphors, catalysts, glass industry, and in other applications. Recycling is one of the main approaches by which to acquire rare earth metals for new production, and shows prominent advantages over processing natural ores with regard to separation process, economic effectiveness, and operator's health. Recycling of rare earths from NdFeB magnet scrap has attracted more attention because of the ever‐increasing demand for neodymium magnets. Presently, only in‐plant NdFeB magnet scrap has been recovered by manufacturers, and the out‐of‐plant scrap from end‐of‐life is hardly recycled. This is mainly attributed to inefficient collection, technological disadvantages, and lack of policy supports. The establishment of efficient, fully integrated recycling technologies free of new waste is highly needed and can probably be realized in the future by taking advantage of current literature on rare earth recycling from NdFeB magnet scrap. In this paper, the state of the art in preprocessing end‐of‐life products containing NdFeB magnets and the final rare earth extraction is reviewed, with the main attention to the fundamental understanding of chemistry in the recycling process.
Fluorous Hydrocarbon Oxidation
Authors: Pozzi Gianluca , Quici Silvio 
Published: September 2016

AbstractNumerous examples of easily separable fluorous catalysts and reagents have been reported in the past two decades, with interesting applications in major classes of organic transformations, including hydrocarbon oxidation processes. The initial motivation for the development of fluorous chemistry was for catalyst recycling via liquid–liquid biphase protocols, which are based on the mutual immiscibility of organic solvents and nonpolar, perfluorinated saturated inert fluids, known as perfluorocarbons, at room temperature. Because of the chemical inertness of perfluorocarbons and their ability to solubilize significant volumes of molecular oxygen, fluorous biphasic catalysis was readily recognized as a very attractive procedure for alkane and alkene oxidative functionalization. Recyclable catalytic systems for the epoxidation or allylic oxidation of olefins and for the aerobic oxidation of cycloalkanes and alkylated aromatic hydrocarbons, mostly based on transition metal complexes of robust fluorous nitrogen ligands designed to be selectively soluble in perfluorocarbons, have been developed starting from the late 1990s. Since then, fluorous chemistry has continued to evolve to include separation and recycling strategies that do not necessarily demand the use of perfluorocarbons at the reaction stage. The viability of fluorous protocols as alternatives to the classical liquid–liquid biphase scheme has been demonstrated for selective hydrocarbon oxidation reactions run under environmentally benign conditions. The development of this field of research is outlined here.
Mobile Apps for Green Chemistry
Authors: Clark Alex M. , Williams Antony J. , Ekins Sean 
Published: September 2016

Abstract
Mobile apps are being used in many areas of business productivity as well as in science in general and are normally focused on one task or provide data in a narrow area (e.g., periodic tables). Mobile apps also represent an alternative approach to provide information on green chemistry information as well as concepts to scientists. We describe three apps, Green Solvents, Lab Solvents, and Green Lab Notebook and their utility for green chemistry. Green Solvents and Lab Solvents deliver public data on solvents and their scores for safety, health, environment (air, water, and waste) categories. These would help a scientist substitute particular solvents with those that are greener. The Green Lab Notebook is a structure‐centric tool designed for capturing chemical reactions. Green chemistry metrics are always displayed for a reaction whenever there is enough information to calculate them. These represent first attempts at developing standalone mobile apps for Apple and Android devices. Such apps represent useful tools in the lab and will likely be extended in future.
Catalytic Cyclic Carbonate Synthesis with Sustainable Metals
Authors: Comerford James W. , Ingram Ian D.V. , North Michael , Wu Xiao 
Published: September 2016

AbstractCyclic carbonates, which are useful and nontoxic electrolytes, solvents, and chemical intermediates, can be produced by the 100% atom efficient addition of carbon dioxide to epoxides. In this chapter, we discuss the use of sustainable catalysts based on earth‐abundant metals potassium, aluminum, and iron for this reaction, showcasing the most important and recent examples and their mechanism of operation.
Sustainable Synthesis of Metal Oxide Nanostructures
Authors: Nasir Baig R.B. , Nadagouda Mallikarjuna N. , Polshettiwar Vivek 
Published: September 2016

Abstract

The importance of metal oxide nanostructures and their synthetic methods have been highlighted. The selected applications of metal oxide nanostructures have been discussed in different sections. The structure–activity relationship (SAR) and
in silico
study for the prediction of metal oxide nanostructure zeta potential have been accentuated.
Radical Reactions in Aqueous Media
Authors: Perchyonok Victoria T. 
Published: September 2016

AbstractThe recent focus in the field of biomaterials has been on the design of intelligent materials. Toward this goal, materials have been developed, which can provide specific bioactive signals to control the biological environment around them during the process of materials integration and wound healing. In addition, materials have been developed that can respond to changes in their environment, such as a change in pH or cell‐associated enzymatic activity. In designing such novel biomaterials, researchers have sought not merely to create bioinert materials, but rather materials that can respond to the cellular environment around them to improve device integration and tissue regeneration. Since their discovery, β‐cyclodextrins (CDs) and, more recently, chitosan have served as prototypes for novel host compounds and catalysts. The use of CDs and chitosan as microvessels to perform chemical reactions has attracted the interest of chemists since the 1960s. This review mainly concentrates on the recent developments of organic reactions mediated by native or simply modified CDs and chitosan and in the use of the CDs as well as chitosan as the extra reaction field rather than the enzyme model in aqueous and alternative media as well as the recent use of the materials as bioactive restorative materials in dentistry, highlighting the enormous potential of such materials in biomedical applications and health sciences in general.
Catalytic Epoxidation of Organics from Vegetable Sources
Authors: Guidotti Matteo , Palumbo Chiara 
Published: September 2016

Abstract
Unsaturated fatty acids, fatty acid esters, and terpenes are alkenic molecules that can be extracted directly from vegetable sources and converted into a broad range of intermediates, commodities, and high value‐added products by means of epoxidation reactions. Conventional stoichiometric epoxidation techniques using environmentally unfriendly oxidants are still performed at the industrial scale. However, several examples, at the laboratory level, show how it is possible to use more sustainable oxidants, such as alkyl hydroperoxides, hydrogen peroxide or, in the best cases, molecular oxygen, in the presence of catalytic systems. Homogeneous, heterogeneous, enzymatic catalysts or, even, metal‐free organocatalysts can help in avoiding the use of hazardous oxidants and noxious solvents and in performing an efficient, selective, and safe epoxidation of C=C bonds in oils, fatty derivatives, and terpenic compounds.
Challenges in Green Analytical Chemistry
Authors: Garrigues Salvador , Armenta Sergio , de la Guardia Miguel 
Published: September 2016

AbstractThe challenges on Green Inorganic Analysis, in the frame of a sustainable analytical chemistry free from the deleterious side effects of the analytical practices, are presented and discussed. Special attention will be paid on the evaluation of the method greenness, the different approaches available in the scientific literature to do inorganic analysis, the inorganic materials used as analytical tools and their synthesis, and the special character of inorganic wastes that are really difficult to be degraded but can be easily mobilized in the environment suffering bioaccumulation processes and transformation in the food chain.
Sustainable Nanomaterials
Authors: Ahmad Shahzad , Tripathy Divya Bajpai , Mishra Anuradha 
Published: September 2016

Abstract
Nanotechnology had a major impact in our society, as the diverse nature of nanomaterials shows its necessity in various fields including electronics, energy production, medical, and drug development. Nevertheless, the nanomaterials also show some serious problems on environment, human health and safety upon its exposure either directly or via consumer products. The prime objective of sustainable nanotechnology is to minimize environmental and human health risks associated with the nanomaterials and to encourage replacement of existing materials with new nanomaterials that are more eco‐friendly throughout their lifecycle. Authors briefly discuss on the classification of nanomaterials and their applications.
Ionic Liquids: Industrial Applications
Authors: Durga Geeta , Mishra Anuradha 
Published: September 2016

Abstract
Ionic liquids (ILs) constitute a class of solvents containing organic cation along with organic/inorganic anion characterized by low melting point (<100 °C) and negligible vapor pressure. These solvents are promising alternatives for conventional organic solvents by virtue of being environmentally benign. No toxic gases are released by ILs upon their usage. The physicochemical properties of ILs can easily be tailored by varying the structure/combination of cation and anion ranging from lipophilic to lipophobic, viscous to nonviscous, polar to nonpolar, and water miscible to immiscible. Other desirable properties of ILs are high thermal stability, nonflammability, and large electrochemical window. ILs have been emerged as “green solvents” over the period of time, and the industrial applications of ILs have been increasing progressively, which are diversified from the solvent for the syntheses (organic, inorganic, or polymer) to catalysis, analytical separations, extractions, electrochemistry, lubrication, and so on. Some of the relatively newer industrial applications of ILs are the fabrication of supported liquid membranes (SILM) for the selective separation of different metal ions/organic compounds/biologically important compounds in dilute streams, and gas mixtures, biomass transformation into fuel, and chemicals and nuclear waste management. Many of these have been developing at pilot plant and commercial levels.
Siroheme Decarboxylase in Complex with Iron‐Uroporphyrin
III
Authors: Layer Gunhild 
Published: September 2016

Abstract

Siroheme decarboxylase catalyzes the conversion of siroheme to 12,18‐didecarboxysiroheme during heme
d
1
biosynthesis in denitrifying bacteria and during the alternative heme biosynthesis in archaea and sulfate‐reducing bacteria. The crystal structure of siroheme decarboxylase from
Hydrogenobacter thermophilus
in complex with the substrate analog iron‐uroporphyrin III is available as well as the structure of siroheme decarboxylase from
Desulfovibrio desulfuricans
in complex with the reaction product didecarboxysiroheme. The two structures reveal two possible binding modes for the iron‐containing tetrapyrroles. In both cases, the central iron ion is coordinated by a histidine residue as the axial ligand, however, these histidines are located at different positions of the enzyme. Moreover, although identical amino acid residues coordinate the substrate analog and reaction product, the respective equivalent residues interact with different parts of the respective tetrapyrrole macrocycle. The two observed tetrapyrrole binding modes might hint toward two different binding sites for the initial substrate, siroheme, and the reaction intermediate monodecarboxysiroheme.
Production of Biopropylene Using Biomass‐Derived Sources
Authors: Vasiliadou Efterpi S. , Lemonidou Angeliki A. 
Published: September 2016

Abstract
Propylene along with ethylene forms the backbone of the petrochemical industry. Propylene is the second most important key intermediate for the production of a variety of end‐use chemicals. Industrial processes producing propylene today are primarily steam cracking and fluid catalytic cracking, which amount up to 90% of propylene production. Apart from steam cracking and fluid catalytic cracking, on‐purpose propylene production processes (e.g., dehydrogenation, metathesis, and methanol to olefins) are becoming more important owing to increasing propylene demand. On the other hand, there is intense research interest to sustainable production of propylene using biomass resources instead of fossil raw materials. In this sense, various renewable processes have been developed utilizing lignocellulosic and triglyceride‐based biomass sources. The most important among them are bioethylene and biobutene metathesis as well as biomethanol to propylene. In addition to these technologies, novel catalytic routes based on biomass‐derived oxygenates, the most important being glycerol, have demonstrated high potential for future commercialization. Glycerol‐selective conversion to propylene is realized via catalytic deoxygenation routes at mild operating conditions (200–300 °C). These reactions are catalyzed by either metal catalysts or metal oxide and carbide systems. Molybdenum oxides and carbides have shown unique catalytic performance by selectively activating CO/CO bonds, while retarding CC bonds of the oxygenates. In most cases, propylene is the main product formed achieving very high yields, up to 90%. These processes will definitely play an important role in propylene production in the near future realizing the concept of biorefineries.
Copper‐Catalyzed Ring‐Expansion/Thiolactonization via Azidation of Internal Olefinic C–H Bond under Mild Conditions
Authors: Guo Tenglong , Jiang Quanbin , Yu Zhengkun 
Published: September 2016

AbstractA copper(I)‐catalyzed, (diacetoxyiodo)benzene [PhI(OAc)2]‐mediated ring‐expansion/thiolactonization of α‐oxo ketene dithioacetals was efficiently realized via azidation of the internal olefinic C−H bond with sodium azide under mild conditions. Sequential amination, ring‐expansion rearrangement, and thiolactonization occurred to form aminated thiolactones in the presence of acetic anhydride as the additive, while only C−H amination to afford the unprotected enamines occurred when using ammonium sulfide as a reducing additive. The in situ generated vinyl azides were confirmed as the reactive intermediates, which were captured by phenylacetylene to produce triazoles. This protocol provides a concise route to thiolactone derivatives and unprotected enamines.magnified image
Outcomes of outpatient endoscopic repair of cerebrospinal fluid rhinorrhea
Authors: Adams Austin S. , Francis David O. , Russell Paul T. 
Published: September 2016

BackgroundEndoscopic repair of anterior skull‐base defects has become the gold standard for management of cerebrospinal fluid (CSF) rhinorrhea. Both improved techniques and adjuvant therapies have led to accepted success rates of greater than 90%. As management has evolved, shorter hospitalizations have been required and the goal of this study is to analyze the outcomes of patients repaired on an outpatient basis vs those managed as inpatients postoperatively.MethodsPatients undergoing endoscopic repair of CSF rhinorrhea between 2004 and 2014 were identified by review of medical records. Demographic and clinical data were collected and compared between patients having surgery with and without postoperative admission. Patients managed with lumbar drains were not included. Statistical analyses were preformed to determine if any differences in patient demographics and outcomes existed.ResultsA total of 86 patients were identified; 39 of 86 patients (45.3%) underwent outpatient surgery; 47 patients were admitted postoperatively with a mean hospital stay of 1.66 days with a median and mode of 1 day. No statistically significant differences were found between leak location, etiology, rates of recurrence, or complications. The outpatient group was found to have a greater proportion of small defects <1 cm2 (p = 0.003). Repair technique was also significantly different between groups (p = 0.001).ConclusionEndoscopic management of CSF rhinorrhea is a safe method of treatment with reliable success rates. Our retrospective analysis revealed comparable outcomes in patients treated with and without postoperative hospital admission, and supports the idea that outpatient management may be reasonable in certain patients, especially those with defects <1 cm2.
The Nucleophilicity of Persistent α‐Monofluoromethide Anions
Authors: Zhang Zhe , Puente Ángel , Wang Fang , Rahm Martin , Mei Yuncai , Mayr Herbert , Prakash G. K. Surya 
Published: September 2016

Abstractα‐Fluorocarbanions are key intermediates in nucleophilic fluoroalkylation reactions. Although frequently discussed, the origin of the fluorine effect on the reactivity of α‐fluorinated CH acids has remained largely unexplored. We have now investigated the kinetics of a series of reactions of α‐substituted carbanions with reference electrophiles to elucidate the effects of α‐F, α‐Cl, and α‐OMe substituents on the nucleophilic reactivities of carbanions.
Cycloaddition von P‐C‐Einfachbindungen: Stereoselektive Bildung von Benzo‐1,3,6,2‐trioxaphosphepinkomplexen über einen ditopischen Van‐der‐Waals‐Komplex
Authors: Malik Payal , Espinosa Ferao Arturo , Schnakenburg Gregor , Streubel Rainer 
Published: September 2016

AbstractWährend für Phosphaalkene und Phosphane die Teilnahme an [4+n]‐Cycloadditionen bekannt ist, sind P‐C‐Einfachbindungen diesbezüglich inert. Wir stellen hier Reaktionen von Oxaphosphirankomplexen mit Tetrachlor‐ortho‐benzochinon (TOB) vor, die eine Reaktion an der endocyclichen P‐C‐Bindung zeigen, welche stereoselektiv zu Benzo‐1,3,6,2‐trioxaphosphepinkomplexen führt. DFT‐Rechnungen auf höchstem Niveau liefern Hinweise darauf, dass das endgültige Produkt aus einer Sequenz dreier konsekutiver Schritte stammt, die einen ditopischen Van‐der‐Waals‐Komplex beinhalten.
Sodium and Manganese Stoichiometry of P2‐Type Na2/3MnO2
Authors: Kumakura Shinichi , Tahara Yoshiyuki , Kubota Kei , Chihara Kuniko , Komaba Shinichi 
Published: September 2016

AbstractTo realize a reversible solid‐state MnIII/IV redox couple in layered oxides, co‐operative Jahn–Teller distortion (CJTD) of six‐coordinate MnIII (t2g3–eg1) is a key factor in terms of structural and physical properties. We develop a single‐phase synthesis route for two polymorphs, namely distorted and undistorted P2‐type Na2/3MnO2 having different Mn stoichiometry, and investigate how the structural and stoichiometric difference influences electrochemical reaction. The distorted Na2/3MnO2 delivers 216 mAh g−1 as a 3 V class positive electrode, reaching 590 Wh (kg oxide)−1 with excellent cycle stability in a non‐aqueous Na cell and demonstrates better electrochemical behavior compared to undistorted Na2/3MnO2. Furthermore, reversible phase transitions correlated with CJTD are found upon (de)sodiation for distorted Na2/3MnO2, providing a new insight into utilization of the MnIII/IV redox couple for positive electrodes of Na‐ion batteries.
Entgiftung von VX und anderen V‐Stoffen in Wasser bei 37 °C und pH 7.4 durch substituierte Sulfonatocalix[4]arene
Authors: Schneider Christian , Bierwisch Anne , Koller Marianne , Worek Franz , Kubik Stefan 
Published: September 2016

AbstractSulfonatocalix[4]arene mit einem geeigneten Hydroxamsäurerest können neurotoxische Organophosphonate der Klasse der V‐Stoffe mit Halbwertszeiten bis hinunter zu 3 min in wässriger Pufferlösung bei 37 °C und pH 7.4 entgiften. Diese Aktivität ist auf die millimolare Affinität des Calixarenrings für kationische V‐Stoffe in Kombination mit einer geeigneten Positionierung des Hydroxamsäurerests zurückzuführen. Bei der Reaktion wird zunächst die Hydroxamsäure phosphonyliert. Anschließend erfolgt eine Lossen‐Umlagerung, sodass der Wirkmechanismus dieser Verbindungen insgesamt stöchiometrischer und nicht katalytischer Natur ist. Dennoch stellen die entwickelten Calixarene momentan die effizientesten synthetischen Scavenger dar, die persistente V‐Stoffe unter milden Bedingungen entgiften. Sie können als Leitverbindungen für neue Wirkstoffe aufgefasst werden, die eine Behandlung von Vergiftungen mit hochtoxischen Nervenkampfstoffen ermöglichen.
Detoxification of VX and Other V‐Type Nerve Agents in Water at 37 °C and pH 7.4 by Substituted Sulfonatocalix[4]arenes
Authors: Schneider Christian , Bierwisch Anne , Koller Marianne , Worek Franz , Kubik Stefan 
Published: September 2016

AbstractSulfonatocalix[4]arenes with an appended hydroxamic acid residue can detoxify VX and related V‐type neurotoxic organophosphonates with half‐lives down to 3 min in aqueous buffer at 37 °C and pH 7.4. The detoxification activity is attributed to the millimolar affinity of the calixarene moiety for the positively charged organophosphonates in combination with the correct arrangement of the hydroxamic acid group. The reaction involves phosphonylation of the hydroxamic acid followed by a Lossen rearrangement, thus rendering the mode of action stoichiometric rather than catalytic. Nevertheless, these calixarenes are currently the most efficient low‐molecular‐weight compounds for detoxifying persistent V‐type nerve agents under mild conditions. They thus represent lead structures for novel antidotes that allow treatment of poisonings by these highly toxic chemicals.