bluuebunny/crossref_metadata_2025 huggingface dataset:
Systems Toxicology
Authors: Talikka Marja , Boué Stephanie , Frentzel Stefan , Kogel Ulrike , Sierro Nicolas , Titz Bjorn , Veljkovic Emilija , Hoeng Julia , Peitsch Manuel C.
Published: June 2016

The human respiratory tract is exposed to numerous contaminants; traditional toxicity testing methods are insufficient to understand the extent of their biological impact and to recommend dose guidelines for safe exposure. Systems toxicology approaches are starting to shape the way for a better assessment of toxicity associated with inhaled substances. A well‐designed assessment pipeline begins with the choice of the experimental system, exposure modality, and characterization of the exposure. The different omics technologies are a crucial part of modern toxicity testing by providing a holistic, unbiased view of a substance's impact. Transcriptomics technologies give insight into the differential expression of genes resulting from exposures, and genomics technologies assess the impact on the DNA itself. Large‐scale proteomics and metabolomics measurements provide additional layers of data and enable the detailed interpretation of the outcome of differential gene expression and the analysis of processes. Network biology is emerging as a powerful tool to filter relevant signal from noise using a priori knowledge. The quantitative aspect of network scoring allows the comparison of different doses and exposure durations and represents the impact as a single holistic score. Crowd sourcing facilitates the collaborative and transparent establishment and verification of toxicity testing methods.
ArylamineN‐Acetyltransferases
Authors: Grant Denis M.
Published: June 2016

ArylamineN‐acetyltransferases (NATs) are phase II xenobiotic‐conjugating enzymes that have a restricted substrate preference for theN‐ orO‐acetylation of aromatic amine and theirN‐oxidized metabolites. Although the number of clinically useful drugs whose disposition depends on acetylation is relatively small, the risk for toxicity from these agents is significant. In addition, a much larger number of potentially hazardous environmental aromatic amines may be acetylated, and this process may contribute to either the detoxication or the metabolic activation of such chemicals into reactive electrophiles with the potential to damage cellular macromolecules. The structures of the two human NAT enzymes NAT1 and NAT2 have been determined; the structural features allow for the detailed description of a two‐step catalytic mechanism and for a rationalization of their distinct substrate preferences. Although the human isoniazid acetylation polymorphism is controlled by allelic variation at theNAT2gene locus, a considerable variation exists in theNAT1gene. Numerous associations have been reported between variable NAT function and risk for cancers associated with exposure to aromatic amines. In addition, possible novel roles for NAT1 and its mammalian orthologs in folate homeostasis and in cellular proliferation are being actively explored.
Aluminum: Organometallic Chemistry
Authors: Mason Mark R.
Published: June 2016

The synthesis, reactivity, structures, and applications of the organometallic compounds of aluminum are reviewed. This article starts with a discussion of traditional synthetic approaches to aluminum alkyls, aryls, hydrides, and halides and continues with a discussion of their structures and reactivity. The following section focuses on the emerging organometallic chemistry of Al(0), Al(I), and Al(II) and specifically highlights recent developments in aluminum–aluminum bonding, insertions of small molecules and elements into Al–Al bonds, and the isolation of large metalloid clusters such as . Organoaluminum heterocycles and cage compounds are the subjects of the next section that briefly describes the common structural motifs and has separate subsections devoted to cage iminoalanes, alkylaluminoxanes, alkylaluminophosphinates, ‐phosphates, ‐phosphonates, and ‐arsonates. Structural relationships among these groups of compounds and comparisons to secondary building units in aluminophosphate molecular sieves are presented. The importance of alkylaluminoxanes to catalytic activity is also discussed. This article includes an independent section on cationic organoaluminum complexes. Although this includes more traditional cationic complexes ligated by crown ether and neutral nitrogen‐donor ligands, the section emphasizes the recent developments in generating two‐ and three‐coordinate cationic complexes. Alkide and hydride abstractions by trityl salts of weakly coordinating anions and tris(pentafluorophenyl)borane are described. Common anion decomposition pathways and successful cationic systems for oligomerizing and polymerizing alkenes are discussed. Two additional sections describe the applications of organoaluminum compounds to organic synthesis and applications in industry. Readers are referred to leading works that more adequately describe the extensive use of organoaluminum reagents in organic synthesis. Current and past applications of organoaluminum compounds for the production of long‐chain alkenes and alcohols, as cocatalysts for Ziegler–Natta and metallocene‐catalyzed polymerization of alkenes and dienes and catalysts for alkene oligomerization and epoxide polymerization, are summarized. Safety issues regarding the handling and disposal of pyrophoric organoaluminum reagents and waste are also discussed. One hundred thirty seven reviews and original works are cited.
Antimony: Inorganic Chemistry
Authors: Fischer Roland C.
Published: June 2016

This article covers the inorganic chemistry of the element antimony. Information on the occurrence, production, use, and properties of the element and of compounds with bonds between antimony and main group elements (except carbon) and transition metals are provided.
Antimony: Organometallic Chemistry
Authors: Fischer Roland C.
Published: June 2016

This article covers the organometallic chemistry of the element antimony. Information on the formation, reactions, and properties of compounds of the element carrying at least one antimony–carbon bond are provided. Furthermore, organometallic compounds with additional bonds between antimony and main group elements except carbon and transition metals are described.
Biomineralization
Authors: Dauphin Yannicke
Published: June 2016

Biominerals are a common feature in nature: they are bones and teeth, and also “shells”. They have been known for hundreds of millions of years in animals and plants. Three main categories exist: silica (sponges), calcium phosphates (bone, teeth), and calcium carbonates (shells). Calcium phosphates and calcium carbonates are mainly crystalline, whereas silica is not. Biominerals are a mixture of extracellular organic components and mineral, secreted by specialized cells and tissues. Their arrangement (micro‐ and nanostructure) and composition are species specific. Consequently, they clearly differ from their inorganically formed counterparts. The organic components are proteins, polysaccharides, and lipids. Biominerals are used as diagnostic criteria for phylogeny, paleoenvironmental recorders in archeology and geology, medical uses, aquaculture, and biomimetics.
Gallium and Indium Compounds in Homogeneous Catalysis
Authors: Dagorne Samuel , Fliedel Christophe , de Frémont Pierre
Published: June 2016

The present contribution highlights the most recent and representative developments on the use of Ga and In species in homogeneous catalysis. Recent studies of various ligand‐supported Ga(III) and In(III) compounds in cyclic esters polymerization catalysis for the production of biodegradable polyester materials are also included. Various organic transformations may now be catalyzed using Ga(III) and In(III) Lewis acids allowing access to a wide range of valuable organic molecules through diverse reaction sequences. The recent use of stable and robustN‐heterocyclic carbene Ga(III) and In(III) compounds as strong π‐Lewis acid catalysts for various organic reactions is also discussed: such species are certainly promising for the future developments of Ga(III)‐ and In(III)‐mediated reactions. Although Lewis acid‐assisted reactions certainly dominate the field in Ga(III) and In(III) chemistry, discrete low‐valent In(I) species, presently emerging in catalysis, clearly display a distinct reactivity allowing their exploitation both as soft Lewis acids and alkyl‐/allyl‐/arylating agents.
Extracytoplasmic Nickel‐Binding Proteins
Authors: Cavazza Christine
Published: June 2016

In bacteria, nickel is required for the activation of at least nine enzymes. Among several nickel import systems dedicated to Ni(II) acquisition, canonical ABC‐type importers possess an extracytoplasmic nickel‐binding protein (or Ni‐BP) that serves as the initial receptor and the major determinant of the transporter specificity. Ni‐BPs evolved from peptide‐BPs from at least four independent evolutionary origins. Their evolutionary history is dominated by horizontal gene transfers among bacteria and Archaea, among Gram‐positive and Gram‐negative bacteria, and among organisms having different lifestyles. Phylogeny of Ni‐BPs explains the promiscuous behavior of this class of Ni(II) carriers. In the Ni‐BPs family, a diversity of nickel‐binding motifs was identified, precluding the determination of a common consensus nickel‐binding mode. Different strategies to bind Ni(II) in the protein cavity have been described. Ni‐BPs binds either free nickel ions or chelated Ni(II). Naked nickel binds to the protein via three histidine residues. In several Ni‐BPs, only one histidine residue is involved in direct nickel–protein contact and a chelator that binds to the protein via supramolecular interactions is required to complete the coordination sphere of the metal. InStaphylococcus aureus, Ni‐BPs do not possess any histidine in their nickel‐binding motifs and the nickel complex is stabilized in the binding pockets via salt bridges with arginines and interactions with aromatic residues. Depending on the growth conditions and nickel availability in the environment, the chelators are either available molecules in the environment such as L‐histidine or by‐products of the metabolism or putative endogenous biosynthetic nickelophores.
BacillussubtilisPhosphodiesterasePhoD
Authors: Rodriguez Fernanda , Lillington James
Published: June 2016

Bacillus subtilisPhoD is an extracytoplasmic alkaline phosphodiesterase that liberates phosphate from organic compounds. PhoD active site contains one Fe3+ion and two Ca2+ions. Structurally, PhoD is similar to the metallophosphatase family of eukaryotic purple acid phosphatases (PAPs). PAPs have two metal ions at their active site, Fe3+and M2+of variable identity. M2+is frequently an Fe or Zn. As in the PAPs, the Fe3+ion in PhoD is coordinated to a tyrosine. However, PhoD has a Ca2+at the M2+site, and a second supporting Ca2+. PhoD also exhibits a C‐terminal α‐helix, which buries the active site. It is probable that the C‐terminal α‐helix has a regulatory role in PhoD activity.
The Ectoine Hydroxylase: A Nonheme‐Containing Iron(
II
) and 2‐Oxoglutarate‐Dependent Dioxygenase
Authors: Widderich Nils , Bremer Erhard , Smits Sander HJ
Published: June 2016

Ectoine and 5‐hydroxyectoine are well‐recognized members of the compatible solutes and are widely employed by microorganisms as osmostress protectants. The EctABC enzymes catalyze the synthesis of ectoine. A subgroup of the ectoine producers can convert ectoine into 5‐hydroxyectoine through a region‐selective and stereospecific hydroxylation reaction catalyzed by the EctD protein, a member of the nonheme‐containing iron(II) and 2‐oxoglutarate‐dependent dioxygenase superfamily.

Structures of EctD are known from the
Virgibacillus salexigens
EctD protein in its apo‐ and iron‐bound forms. Furthermore, a set of crystal structures is known from the EctD protein from
Sphingopyxis alaskensis
in its apo‐ and Fe(II)‐bound forms and also from a dead‐end complex of EctD together with the substrate 2‐oxogluterate and the product 5‐hydroxyectoine. In this article, we describe the purification and biochemically characterization of nine different EctD proteins from different species. Furthermore, the importance of the Fe(II) ligand and its binding site is described. The octahedral geometry of Fe(II) binding is mediated
via
two histidine and one aspartate side chain together with water molecules. The latter are replaced by the binding of the 2‐oxoglutarate substrate to the EctD enzyme. The binding mechanism of Fe(II) is strictly conserved within the EctD protein superfamily.
Bacterial Siderophore‐Binding ProteinFepB
Authors: Krewulak Karla D , Vogel Hans J
Published: June 2016

Many bacteria can produce and secrete ferric‐iron‐specific chelators, called siderophores, to remove bound ferric iron from host proteins. The catecholate‐type siderophore enterobactin is a high‐affinity siderophore that is used by many Gram‐negative and Gram‐positive bacteria to acquire iron. In Gram‐negative bacteria, the ferric‐enterobactin (Fep) uptake system includes the outer membrane receptor FepA, the periplasmic binding protein (PBP) FepB, and the cytoplasmic membrane ABC transporter FepDG and FepC. FepB is a PBP with a type III structure fold, which has two independently folded domains linked together by a long α‐helix. This article will provide a comprehensive look at the structural and functional aspects of the 34 kDa PBP FepB.
Fe‐S‐Basedl‐Serine Dehydratases
Authors: Holden Hazel M , Thoden James B , Grant Gregory A
Published: June 2016

l‐Serine dehydratases are nonredox iron‐sulfur proteins that convertl‐serine to pyruvate and ammonia. They are found only in bacteria and contain a diamagnetic [4Fe‐4S]2+center that acts as a Lewis acid. In addition to a catalytic domain that contains the Fe‐S cluster, they also possess at least one other structural domain that may be involved in the regulation of catalytic activity. At least four types are known that are differentiated based on their domain arrangements and number of polypeptide chains. The available crystal structure is that fromLegionella pneumophila, which shows a bilobal molecule with the active site at the interface of two domains. In this structure, a C‐terminal cysteine residue forms a fourth coordination site with the Fe‐S cluster that appears to act as an intrinsic competitive inhibitor as it interacts with the cluster in a manner very similar to that which would be required by the substrate. Kinetic evidence supports a model wherel‐serine binds to a second noncatalytic site to activate the enzyme and induce the opening of the active site to substrate.
Anisotropic3DColloidal Quantum Nanostructures
Authors: Govan Joseph , Spiridonov Igor , Fedorov Anatoly , Baranov Alexander , Gun'ko Yurii K.
Published: June 2016

3D anisotropic semiconductor nanostructures have unique physical properties including a high aspect ratio, optical polarization anisotropy, polarized photoluminescence, giant birefringence, and many others. Theoretical studies of anisotropic semiconductor nanostructures have shown that their electronic and optical properties dramatically depend on their shape and size. These factors open up an access to new generation of optical, optoelectronic, and light‐harvesting devices. In this article, we demonstrate advances in the development of new 3D quantum‐confined colloidal nanostructures such as semiconductor nanotetrapods, nanomultipods, nanoflowers, nanostar and other shapes. We present the latest progress in various colloidal chemistry approaches for the synthesis of these nanostructures. We also consider the self‐organization of quantum dots in 3D superparticles. We discuss structure–property relations as well as the corresponding potential applications of these nanomaterials in light‐harvesting, energy‐conversion devices, sensing, photocatalysis, biology, and other areas. Finally, we provide conclusions and an outlook for the future development of anisotropic semiconductor nanomaterials and their technological prospects.
Ring‐Opening/Expansion Rearrangement of Cycloprop[2,3]inden‐1‐ols Catalyzed by p‐Toluenesulfonic Acid
Authors: Li Pei‐Fang , Yi Cheng‐Bo , Ren Shu‐Jian , Qu Jin
Published: June 2016

A divergent approach to generate either 1‐hydroxymethylindenes (which could then be converted to benzofulvenes through a dehydration reaction) or naphthalenes by the rearrangement of cycloprop[2,3]inden‐1‐ols is reported. The effect of the cyclopropyl ring substitution pattern on ring‐opening/expansion rearrangements of the substrates was systemically studied.

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Dopant‐Free Hole Transporting Polymers for High Efficiency, Environmentally Stable Perovskite Solar Cells
Authors: Liao Hsueh‐Chung , Tam Teck Lip Dexter , Guo Peijun , Wu Yilei , Manley Eric F. , Huang Wei , Zhou Nanjia , Soe Chan Myae Myae , Wang Binghao , Wasielewski Michael R. , Chen Lin X. , Kanatzidis Mercouri G. , Facchetti Antonio , Chang Robert P. H. , Marks Tobin J.
Published: June 2016

Over the past five years, a rapid progress in organometal‐halide perovskite solar cells has greatly influenced emerging solar energy science and technology. In perovksite solar cells, the overlying hole transporting material (HTM) is critical for achieving high power conversion efficiencies (PCEs) and for protecting the air‐sensitive perovskite active layer. This study reports the synthesis and implementation of a new polymeric HTM series based on semiconducting 4,8‐dithien‐2‐yl‐benzo[1,2‐d;4,5‐d′]bistriazole‐alt‐benzo[1,2‐b:4,5‐b′]dithiophenes (pBBTa‐BDTs), yielding high PCEs and environmentally‐stable perovskite cells. These intrinsic (dopant‐free) HTMs achieve a stabilized PCE of 12.3% in simple planar heterojunction cells—the highest value to date for a polymeric intrinsic HTM. This high performance is attributed to efficient hole extraction/collection (the most efficient pBBTa‐BDT is highly ordered and orients π‐face‐down on the perovskite surface) and balanced electron/hole transport. The smooth, conformal polymer coatings suppress aerobic perovskite film degradation, significantly enhancing the solar cell 85 °C/65% RH PCE stability versus typical molecular HTMs.
Mesoporous MoO3–x Material as an Efficient Electrocatalyst for Hydrogen Evolution Reactions
Authors: Luo Zhu , Miao Ran , Huan Tran Doan , Mosa Islam M. , Poyraz Altug S. , Zhong Wei , Cloud Jacqueline E. , Kriz David A. , Thanneeru Srinivas , He Junkai , Zhang Yashan , Ramprasad Rampi , Suib Steven L.
Published: June 2016

A unique approach for the synthesis of nonstoichiometric, mesoporous molybdenum oxide (MoO3–x) with nanosized crystalline walls by using a soft template (PEO‐b‐PS) synthesis method is introduced. The as‐synthesized mesoporous MoO3–x is very active and stable (durability > 12 h) for the electrochemical hydrogen evolution reaction (HER) under both acidic and alkaline conditions. The intrinsic MoO3 serves as an HER electrocatalyst without the assistance of carbon materials, noble metals, or MoS2 materials. The results from transmission electron microscopy and N2 sorption techniques show that the as‐synthesized mesoporous MoO3–x has large accessible pores (20–40 nm), which are able to facilitate mass transport and charge transfer during HER. In terms of X‐ray diffraction, X‐ray photoelectron spectroscopy, temperature‐programmed oxidation, and diffusive reflectance UV–vis spectroscopy, the mesoporous MoO3–x exhibits mixed oxidation states (Mo5+, Mo6+) and an oxygen‐deficient structure. The as‐synthesized MoO3–x only requires a low overpotential (≈0.14 V) to achieve a 10 mA cm−2 current density in 0.1 m KOH and the Tafel slope is as low as 56 mV dec−1. Density functional theory calculations demonstrate a change of electronic structure and the possible reaction pathway of HER. Oxygen vacancies and mesoporosity serve as key factors for excellent performance.
A generalized stochastic modelling approach for crystal size distribution in antisolvent crystallization operations
Authors: Baratti Roberto , Tronci Stefania , Romagnoli Jose A.
Published: June 2016

A generalized formulation for the development of stochastic models to predict the crystal size distribution (CSD) in antisolvent crystallization processes is proposed. Exploiting the result of the noise induced dynamic in stochastic processes, new results are provided to represent the CSD as function of the operational parameters. The generalized formulation enables the full description of the CSD using nonlinear drift term in conjunction with multiplicative noise, i.e., state dependent diffusion. For the first time a deterministic nonlinear differential equation to represent the mean and most probable size (mode) time evolution as function of the model parameters is provided. Furthermore, the analytical solution of the asymptotic probability distribution of the CSD can also be obtained. Finally, a global model formulation is finally presented by defining relationships between the model parameters and the operating conditions. Experimental results and validations are provided using the ternary system of NaCl, water, and ethanol. © 2016 American Institute of Chemical Engineers AIChE J, 63: 551–559, 2017
Mathematical modeling of erythrocyte chimerism informs genetic intervention strategies for sickle cell disease
Authors: Altrock Philipp M. , Brendel Christian , Renella Raffaele , Orkin Stuart H. , Williams David A. , Michor Franziska
Published: June 2016

Recent advances in gene therapy and genome‐engineering technologies offer the opportunity to correct sickle cell disease (SCD), a heritable disorder caused by a point mutation in the β‐globin gene. The developmental switch from fetal γ‐globin to adult β‐globin is governed in part by the transcription factor (TF) BCL11A. This TF has been proposed as a therapeutic target for reactivation of γ‐globin and concomitant reduction of β‐sickle globin. In this and other approaches, genetic alteration of a portion of the hematopoietic stem cell (HSC) compartment leads to a mixture of sickling and corrected red blood cells (RBCs) in periphery. To reverse the sickling phenotype, a certain proportion of corrected RBCs is necessary; the degree of HSC alteration required to achieve a desired fraction of corrected RBCs remains unknown. To address this issue, we developed a mathematical model describing aging and survival of sickle‐susceptible and normal RBCs; the former can have a selective survival advantage leading to their overrepresentation. We identified the level of bone marrow chimerism required for successful stem cell‐based gene therapies in SCD. Our findings were further informed using an experimental mouse model, where we transplanted mixtures of Berkeley SCD and normal murine bone marrow cells to establish chimeric grafts in murine hosts. Our integrative theoretical and experimental approach identifies the target frequency of HSC alterations required for effective treatment of sickling syndromes in humans. Our work replaces episodic observations of such target frequencies with a mathematical modeling framework that covers a large and continuous spectrum of chimerism conditions. Am. J. Hematol. 91:931–937, 2016. © 2016 Wiley Periodicals, Inc.
Recent Advances in Highly Selective Applications of Nitroso Compounds
Authors: Huang Jiapian , Chen Zhiyuan , Yuan Jianjun , Peng Yiyuan
Published: June 2016

Over the past few years, substantial progress has been achieved in nitroso‐related organic chemistry. Annulation reactions of nitroso compounds with other π‐conjugated systems, in particular through the notable hetero‐Diels–Alder‐type reaction, have drawn much interest from organic chemists because of their high regioselectivities, enantioselectivities, and efficiencies. In addition, the N‐nitroso moiety can also be employed as a powerful and transformable directing group in direct C−H functionalization reactions. Herein, we summarize recent reports on the versatile applications of nitroso compounds as useful building blocks in the selective synthesis of a diverse range of molecules.
Totalsynthese von Aurantosid G, einer N‐β‐glycosylierten 3‐Oligoenoyltetramsäure aus Theonella swinhoei
Authors: Petermichl Markus , Loscher Sebastian , Schobert Rainer
Published: June 2016

Erstmals wurde eine natürliche N‐glycosylierte 3‐Acyltetramsäure synthetisiert. Aurantosid G ist ein tiefroter, in Reinsubstanz höchst empfindlicher Metabolit des Meeresschwammes Theonella swinhoei. Es hat eine chlorsubstituierte Dodecapentaenoyl‐Seitenkette an einer l‐Asparagin‐abgeleiteten Tetramsäure, deren Lactam‐Stickstoffatom eine β‐konfigurierte d‐Xylose trägt. Die Seitenkette wurde über konsekutive Wittig‐ und HWE‐Olefinierungen aufgebaut und für die N‐Acylierung eines Asparaginats verwendet, dessen Aminogruppe bereits vorher über eine Fukuyama‐Mitsunobu‐Reaktion mit einer d‐Xylose verknüpft worden war. In diesem N‐Acylierungsschritt wurde auch die für die fungizide Aktivität essenzielle β‐Konfiguration der Xylose festgelegt, wofür große, elektronenreiche PMB‐Schutzgruppen am Zucker verantwortlich sind. Der Heterocyclus wurde zuletzt quantitativ durch eine basische Lacey‐Dieckmann‐Kondensation eines vollständig entschützten N‐(β‐Ketoacyl)aminosäuresters geschlossen.
Highly Stereoselective Cobalt(III)‐Catalyzed Three‐Component C−H Bond Addition Cascade
Authors: Boerth Jeffrey A. , Hummel Joshua R. , Ellman Jonathan A.
Published: June 2016

A highly stereoselective three‐component C(sp2)−H bond addition across alkene and polarized π‐bonds is reported for which CoIII catalysis was shown to be much more effective than RhIII. The reaction proceeds at ambient temperature with both aryl and alkyl enones employed as efficient coupling partners. Moreover, the reaction exhibits extremely broad scope with respect to the aldehyde input; electron rich and poor aromatic, alkenyl, and branched and unbranched alkyl aldehydes all couple in good yield and with high diastereoselectivity. Multiple directing groups participate in this transformation, including pyrazole, pyridine, and imine functional groups. Both aromatic and alkenyl C(sp2)−H bonds undergo the three‐component addition cascade, and the alkenyl addition product can readily be converted into diastereomerically pure five‐membered lactones. Additionally, the first asymmetric reactions with CoIII‐catalyzed C−H functionalization are demonstrated with three‐component C−H bond addition cascades employing N‐tert‐butanesulfinyl imines. These examples represent the first transition metal catalyzed C−H bond additions to N‐tert‐butanesulfinyl imines, which are versatile and extensively used intermediates for the asymmetric synthesis of amines.
Total Synthesis of Aurantoside G, an N‐β‐Glycosylated 3‐Oligoenoyltetramic Acid from Theonella swinhoei
Authors: Petermichl Markus , Loscher Sebastian , Schobert Rainer
Published: June 2016

The first synthesis of a natural N‐glycosylated 3‐acyltetramic acid is reported. Aurantoside G (1 g), a deep‐red metabolite of the marine sponge Theonella swinhoei, is highly delicate in the pure state. It features a chlorinated dodecapentaenoyl side chain at an l‐asparagine‐derived tetramic acid, the ring nitrogen atom of which is linked to a β‐configured d‐xylose. The side chain was built through consecutive Wittig and HWE reactions and used to N‐acylate the amino group of an asparaginate that had already been N‐xylosylated through a Fukuyama–Mitsunobu reaction. This N‐acylation step fixes the β‐configuration of the xylose, which is essential for the antifungal activity, but only if the sugar carries bulky, electron‐rich protecting groups such as PMB. In the final step, the heterocycle was closed quantitatively through a basic Lacey–Dieckmann condensation of an entirely unprotected precursor.
A Cinchona Alkaloid‐Functionalized Mesostructured Silica for Construction of Enriched Chiral β‐Trifluoromethyl‐β‐Hydroxy Ketones over An Epoxidation‐Relay Reduction Process
Authors: Li Cuibao , Shu Xiaomin , Li Liang , Zhang Genwei , Jin Ronghua , Cheng Tanyu , Liu Guohua
Published: June 2016

A cinchona alkaloid‐functionalized heterogeneous catalyst is prepared through a thiol‐ene click reaction of chiral N‐(3,5‐ditrifluoromethylbenzyl)quininium bromide and a mesostructured silica, which is obtained by co‐condensation of 1,2‐bis(triethoxysilyl)ethane and 3‐(triethoxysilyl)propane‐1‐thiol. Structural analyses and characterizations disclose its well‐defined chiral single‐site active center, and electron microscopy images reveal its monodisperse property. As a heterogenous catalyst, it enables an efficient asymmetric epoxidation of achiral β‐trifluoromethyl‐β,β‐disubstituted enones, the obtained chiral products can then be converted easily into enriched chiral β‐trifluoromethyl‐β‐hydroxy ketones through a sequential epoxidation‐relay reduction process. Furthermore, such a heterogeneous catalyst can be recovered conveniently and reused in asymmetric epoxidation of 4,4,4‐trifluoro‐1,3‐diphenylbut‐2‐enone, showing an attractive feature in a practical construction of enriched chiral β‐CF3‐substituted molecules.
Use of azathioprine and corticosteroids during pregnancy and birth outcome in women diagnosed with inflammatory bowel disease
Authors: Plauborg Anne Veie , Hansen Anne Vinkel , Garne Ester
Published: June 2016

Background

The aim of this study was to describe prescription patterns for azathioprine and corticosteroids for pregnant women with inflammatory bowel diseases (IBD) before, during, and after pregnancy and to describe pregnancy outcomes.

Methods

A cohort composed of all singleton pregnancies in Danish registries from 1996 to 2009 was divided by maternal IBD status: Crohn's disease (CD, n = 827), ulcerative colitis (UC, N = 1361), or no IBD diagnosis (background population, n = 814,231). The number of women with a prescription for azathioprine, local and systemic steroids within a 3‐month period was computed for each of the pregnancy trimesters and the year before and after pregnancy. Outcomes of interest were stillbirth, perinatal mortality, low birth weight (LBW), preterm birth, and small for gestational age (SGA).

Results

Number of prescriptions for azathioprine decreased just before and during pregnancy and increased after birth. Number of prescriptions for local and systemic corticosteroids decreased approximately 30% compared with before pregnancy and increased in the second trimester. There was an increased risk among mothers with IBD of LBW (adjusted odds ratio [adjOR]: CD: 2.25 [95% confidence interval {CI}, 1.74–2.91], UC: 1.81 [95% CI, 1.42–2.30]), preterm birth (adjOR: CD: 2.54 [95% CI, 2.04–3.15], UC: 1.86 [95% CI, 1.52–2.27]), and SGA (adjOR: CD: 1.99 [95% CI, 1.26–3.15], UC: 1.80 [95% CI, 1.18–2.75]).

Conclusion

Use of azathioprine and corticosteroids was often reduced or discontinued before or during early pregnancy followed by an increased use of corticosteroids later in pregnancy. Women diagnosed with IBD and with prescriptions for azathioprine and/or corticosteroids, have an increased risk of LBW, pre‐term birth, and SGA. Birth Defects Research (Part A) 106:494–499, 2016. © 2016 Wiley Periodicals, Inc.
Multitalentierte Biominerale
Authors: Schröder Heinz C. , Wang Xiaohong , Müller Werner E. G.
Published: June 2016

Biomineral bildende Systeme sind weitverbreitet in der Natur, haben jedoch erst in den letzten Jahren größere Aufmerksamkeit erlangt im Hinblick auf die Entwicklung neuer Materialien und deren Anwendung in Medizin und Technik. Beigetragen haben hier insbesondere die Entwickung der modernen Nanotechnologie sowie die Erkenntnis, dass die Hauptklassen der Biominerale, Silica, Calciumcarbonat und Calciumphosphat/Hydroxylapatit, über einen enzymatischen Mechanismus gebildet werden können. Dieser ermöglicht die biokatalytische Herstellung sowohl von organisch‐anorganischen Hybridmaterialien mit neuartigen Eigenschaftskombinationen als auch von definierten Strukturen aus diesen Biomineralen. Die Anwendungen reichen von der Optik über Oberflächenbeschichtungen, der Verkapselung von Zellen, Core‐Shell‐Materialien bis hin zu Implantaten.
Stadtamseln sind anders
Authors: Bosch Stefan , Lurz Peter W. W.
Published: June 2016

Abiotische Faktoren wie Straßenlärm und vor allem Kunstlicht beeinflussen nicht nur Tiere in der Stadt, sondern verändern sie auch. Am Beispiel der Amsel zeigt sich, wie die Anpassung an sich verändernde Rahmenbedingungen mikroevolutionäre Prozesse in Gang setzen kann. Kunstlicht verändert deutlich die Tagesperiodik und Fortpflanzung: Es lässt die Amseln länger wach sein, morgens früher singen und früher im Jahr brüten. Lärm beeinflusst ihren Gesang. Um den Verkehrslärm zu übertönen, singen Stadtamseln lauter und in höheren Tonlagen. Außerdem zeigen Amseln im Verstädterungsprozess ein geringeres Neugier‐ und ein verändertes, dynamisches Furchtverhalten.

Städte haben das Potenzial, Tierarten zu beherbergen, aber auch um sie zu verändern, und eine große Frage für die Zukunft ist daher, ob die Anpassung an die weltweit wachsenden, urbanen Lebensräume zu einer Evolution von neuen “Stadt‐Arten” führt.
Bei Kulturpflanzen der Tomate geht die innere Uhr nach
Authors: Staiger Dorothee
Published: June 2016

Die Tomate hat ihren Ursprung in Südamerika in der Nähe des Äquators und wurde vom Menschen in die gemäßigten Breiten von Amerika und nach Europa gebracht. Während der Domestizierung hat die innere Uhr der Tomate ihre Geschwindigkeit verringert. Dies könnte eine Anpassung an die längeren Tage in unseren Breiten darstellen.
Kommentar zu “Arctic Apples”
Authors: Nellen Wolfgang
Published: June 2016

Kommentar zu: “Arctic Apples” von Christiane Högermann in BIUZ 2/2016, S. 87f.
Systematic review of outcomes after distal pancreatectomy with coeliac axis resection for locally advanced pancreatic cancer
Authors: Klompmaker S , de Rooij T , Korteweg J J , van Dieren S , van Lienden K P , van Gulik T M , Busch O R , Besselink M G
Published: June 2016

Background

Pancreatic cancer involving the coeliac axis is considered unresectable by most guidelines, with a median survival of 6–11 months. A subgroup of these patients can undergo distal pancreatectomy with coeliac axis resection, but consensus on the value of this procedure is lacking. The evidence for this procedure, including the impact of preoperative hepatic artery embolization and (neo)adjuvant therapy, was evaluated.

Methods

A systematic review was performed according to the PRISMA guidelines until 27 May 2015. The primary endpoint was overall survival; secondary endpoints included morbidity and radical resection rates.

Results

A total of 19 retrospective studies, involving 240 patients, were included. The methodological quality of the studies ranged from poor to moderate. A radical resection was reported in 74·5 per cent (152 of 204), major morbidity in 27 per cent (26 of 96), ischaemic morbidity in 9·0 per cent (21 of 223) and 90-day mortality in 3·5 per cent (4 of 113). Overall, 35·5 per cent of patients (55 of 155) underwent preoperative hepatic artery embolization without an apparent beneficial impact on ischaemic morbidity. Overall, 15·7 per cent (29 of 185) had neoadjuvant and 51·0 per cent (75 of 147) had adjuvant therapy. There was a difference in survival between patient series where less than half of patients had (neo)adjuvant chemotherapy and series where more than half were receiving this treatment: case-weighted median overall survival was 16 (range 9–48) versus 18 (10–26) months respectively (P = 0·002). Overall median survival for the whole study population was 14·4 (range 9–48) months.

Conclusion

Distal pancreatectomy with coeliac axis resection seems a valuable option for selected patients with pancreatic cancer involving the coeliac axis with acceptable morbidity and mortality, and a median survival of 18 months when combined with (neo)adjuvant therapy.
Sex determines cortisol and alpha‐amylase responses to acute physical and psychosocial stress in patients with avoidant personality disorder
Authors: Tanaka Yoshihiro , Ishitobi Yoshinobu , Inoue Ayako , Oshita Harumi , Okamoto Kana , Kawashima Chiwa , Nakanishi Mari , Aizawa Saeko , Masuda Koji , Maruyama Yoshihiro , Higuma Haruka , Kanehisa Masayuki , Ninomiya Taiga , Akiyoshi Jotaro
Published: June 2016

Introductions

Avoidant personality disorder (AVPD) has excessive and pervasive anxiety and discomfort in social situations. The aims of this study were to explore the relationship between AVPD and physical and psychological stress and psychological tests.

Methods

We evaluated 93 AVPD patients and 355 nonpatient controls by salivary amylase and cortisol responses during exposure to the Trier Social Stress Test (TSST) and electrical stimulation stress. Spielberger state‐trait anxiety inventory (STAI), Profile of Mood State (POMS), Beck Depression Inventory (BDI), Depression and Anxiety Cognition Scale (DACS), and Childhood Trauma Questionnaire (CTQ) were administered.

Results

Following electrical stimulation, salivary cortisol levels in female AVPD decreased significantly less than that in female's controls, but salivary cortisol levels did not show a difference between male AVPD patients and controls. Salivary alpha‐amylase (sAA) levels did not show a difference between females or male AVPD patients and controls. Following TSST exposure, sAA levels did not show a difference between females or male AVPD patients and controls. Salivary cortisol levels did not show a difference between females or male AVPD patients and controls. In the AVPD patients, POMS scores were significantly higher compared with the controls. STAI, BDI, DACS scores, and CTQ significantly increased in the AVPD patients compared with the controls. LF in heart rate variability in AVPD significantly increased more compared with controls.

Conclusions

These results suggest that heightened sympathetic reactivity in female AVPD co‐occurs with attenuated salivary cortisol responses to electric stimulation stress and there is a significant difference between AVPD and controls in mood, anxiety, social cognition, and automatic nerve systems.
Eudistomin C, an Antitumor and Antiviral Natural Product, Targets 40S Ribosome and Inhibits Protein Translation
Authors: Ota Yu , Chinen Takumi , Yoshida Keisuke , Kudo Shun , Nagumo Yoko , Shiwa Yuh , Yamada Ryosuke , Umihara Hirotatsu , Iwasaki Kotaro , Masumoto Hiroshi , Yokoshima Satoshi , Yoshikawa Hirofumi , Fukuyama Tohru , Kobayashi Junichi , Usui Takeo
Published: June 2016

Eudistomin C (EudiC), a natural product, shows potent antitumor and antiviral activities, but the target molecule and the mechanism of action remain to be revealed. Here, we show that the 40S ribosome is the target in EudiC cytotoxicity. We isolated EudiC‐resistant mutants from a multidrug‐sensitive yeast strain, and a genetic analysis classified these YER (yeast EudiC resistance) mutants into three complementation groups. A genome‐wide study revealed that the YER1‐6 mutation is in the uS11 gene (RPS14A). Biotinylated EudiC pulled down Rps14p‐containing complexes from 40S and 80S ribosomes, but not from the 60S ribosome. EudiC strongly inhibited translation of the wild‐type strain but not of YER1‐6 in cells and in vitro. These results indicate that EudiC is a protein synthesis inhibitor targeting the uS11‐containing ribosomal subunit, and shows cytotoxicity by inhibiting protein translation.
Role of Nitrogen Doping on the Performance of Carbon Nanotube Catalysts: A Catalytic Wet Peroxide Oxidation Application
Authors: Martin‐Martinez Maria , Ribeiro Rui S. , Machado Bruno F. , Serp Philippe , Morales‐Torres Sergio , Silva Adrián M. T. , Figueiredo José L. , Faria Joaquim L. , Gomes Helder T.
Published: June 2016

Four magnetic carbon nanotube (CNT) samples (undoped, completely N‐doped, and two selectively N‐doped) were synthesized by chemical vapor deposition. The materials were tested in the catalytic wet peroxide oxidation (CWPO) of highly concentrated 4‐nitrophenol solutions (4‐NP, 5 g L−1). Relatively mild operating conditions were considered (atmospheric pressure, T=50 °C, pH 3), using a catalyst load of 2.5 g L−1 and the stoichiometric amount of H2O2 needed for the complete mineralization of 4‐NP. N‐doping was identified to influence considerably the CWPO performance of the materials. In particular, undoped CNTs, with a moderate hydrophobicity, favor the controllable and efficient decomposition of H2O2 into highly reactive hydroxyl radicals (HO.), thus showing high catalytic activity for 4‐NP degradation. On the other hand, the completely N‐doped catalyst, fully hydrophilic, favors a quick decomposition of H2O2 into nonreactive O2 and H2O species. The selectively N‐doped amphiphilic catalysts, that is, hybrid structures containing undoped sections followed by N‐doped ones, provided intermediate results, namely, a higher N content favored H2O2 decomposition towards nonreactive H2O and O2 species, whereas a lower N content resulted in the formation of HO., increasing 4‐NP mineralization. Catalyst stability and reusability were also investigated by consecutive CWPO runs.
Role of Crystalline Structure in Allyl Alcohol Selective Oxidation over Mo3VOx Complex Metal Oxide Catalysts
Authors: Murayama Toru , Katryniok Benjamin , Heyte Svetlana , Araque Marcia , Ishikawa Satoshi , Dumeignil Franck , Paul Sébastien , Ueda Wataru
Published: June 2016

The role of the crystalline phase of Mo3VOx in the catalytic oxidation of allyl alcohol over four kinds of crystalline (orthorhombic, trigonal, tetragonal, amorphous) Mo3VOx catalysts was investigated to determine the active sites for the reactions. Tetragonal Mo3VOx was found less active for the formation of acrylic acid from allyl alcohol, although acrolein was obtained selectively at higher temperature. For orthorhombic and trigonal Mo3VOx catalyst, allyl alcohol converted to acrolein and propanal competitively at the mouth of the heptagonal channel over the a–b plane of the rod‐type crystalline particles, and these aldehydes were oxidized consecutively to acrylic acid. Acrylic acid was formed effectively at increased reaction temperature over orthorhombic, trigonal and amorphous Mo3VOx catalysts, and the maximum yields of acrylic acid were 73 % for the orthorhombic Mo3VOx catalyst and 72 % for the trigonal Mo3VOx catalyst at 350 °C.
Side Effect of Good's Buffers on Optical Properties of Gold Nanoparticle Solutions
Authors: Engelbrekt Christian , Wagner Michal , Christiansen Mikkel Undall‐Behrend , Christensen Hans Erik Mølager , Qian Xiuzhen , Ulstrup Jens , Zhao Chongjun , Zhang Jingdong
Published: June 2016

In search of fluorescent nanoclusters (NCs) for bioimaging, several methods of synthesis have been attempted. Particularly, formation of gold NCs (AuNCs) during synthesis of gold nanoparticles (AuNPs) using Good's buffers has been reported based on the optical properties of the reaction mixtures. Here we chose Good's buffers 2‐(N‐morpholino)ethanesulfonic acid (MES), 3‐(N‐morpholino)propanesulfonic acid (MOPS) and 4‐(N‐morpholino)butanesulfonic acid (MOBS) as [AuCl4]−‐reducing agents. Resulting AuNP solutions were subjected to electrochemical investigations along with UV/Vis and fluorescence spectroscopy. Distinct absorption features at approximately 290 and 360 nm and fluorescence emission in the 408–484 nm range in filtered AuNP‐free solutions were observed. Electrochemical oxidation of these buffers generates similar optical properties, suggesting that the degradation products of the buffers contribute to the optical properties of AuNP solutions. This work indicates that a deeper evaluation of fluorescence signals based on metal NPs or NCs is needed.
H2O2 Generation at a Carbon‐Paste Electrode with Decamethylferrocene in 2‐Nitrophenyloctyl Ether as a Binder: Catalytic Effect of MoS2 Particles
Authors: Jedraszko Justyna , Krysiak Olga , Adamiak Wojciech , Nogala Wojciech , Girault Hubert H. , Opallo Marcin
Published: June 2016

Here, we report hydrogen peroxide generation at the 2‐nitrophenyloctyl ether (NPOE)/water interface with decamethylferrocene as an electron donor. The progress of this reaction was detected by the observation of a color change in the organic and aqueous phases in a series of shake‐flask experiments. The shape change in cyclic voltammograms recorded at a carbon‐paste electrode with decamethylferrocene in NPOE also indicates a (electro)catalytic reaction. Hydrogen peroxide was electrochemically detected at a Pt microelectrode tip positioned next to the carbon‐paste electrode. For this purpose, scanning electrochemical microscopy (SECM) approach curves were recorded. Analogous experiments demonstrated the possibility of electrochemical regeneration of the electron donor. The (electro)catalytic effect of MoS2 on hydrogen peroxide generation was found by using both shake‐flask and SECM experiments.
Tuning Mixed‐Valent Eu2+/Eu3+ in Strontium Formate Frameworks for Multichannel Photoluminescence
Authors: Liu Wei , Liu Lijia , Wang Yanlong , Chen Lanhua , McLeod John A. , Yang Linju , Zhao Jia , Liu Zhiyong , Diwu Juan , Chai Zhifang , Albrecht‐Schmitt Thomas E. , Liu Guokui , Wang Shuao
Published: June 2016

Cooperative performance of mixed‐valent Eu2+/Eu3+ in single‐compound phosphors offers significant advantages in color rendering and luminescence efficiency, but their synthesis is challenging because of Eu2+ oxidation. Using the tunable nature of the metal‐ion nodes in metal–organic frameworks (MOFs), we present an in situ reduction and crystallization route for preparing MOFs and doping Eu2+/Eu3+ with a controlled ratio. These materials exhibit rich photoluminescence, including intrinsic‐ and sensitized‐emissions of Eu2+ and Eu3+, and long‐lived luminescence from charge transfer. Color rendering can be easily achieved by fine‐tuning the valence states of Eu. A linear relation between temperature and the intensity ratio of Eu2+/Eu3+ emissions provides outstanding properties for applications as self‐calibrated luminescent thermometers with a wide working temperature range. Further incorporation of Tb3+ into the MOFs results in white light, utilizing all Eu2+,Tb3+, and Eu3+ emissions in a single crystalline lattice.
ChemInform Abstract: Incorporation of Platinum Atoms in a Silicon‐Free Boride of the YB50‐Type Structure.
Authors: Sologub Oksana , Salamakha Leonid P. , Michor Herwig , Bauer Ernst , Stoeger Berthold , Rogl Peter F.
Published: June 2016

YB45‐xPty (x = 2.12, y = 0.21) is prepared by arc‐melting of the elements and subsequent annealing (Ta foil in evacuated quartz tube, 1123 K, 1 week).
ChemInform Abstract: Designing a Beryllium‐Free Deep‐Ultraviolet Nonlinear Optical Material Without a Structural Instability Problem.
Authors: Zhao Sangen , Kang Lei , Shen Yaoguo , Wang Xiaodong , Asghar Muhammad Adnan , Lin Zheshuai , Xu Yingying , Zeng Siyuan , Hong Maochun , Luo Junhua
Published: June 2016

K3Ba3Li2Al4B6 O20F is prepared by solid state reaction of a stoichiometric mixture of K2CO3, BaCO3, Li2CO3, Al2O3, LiF, and H3BO3 (1.
ChemInform Abstract: Neodymium Electrowinning into Copper‐Neodymium Alloys by Mixed Oxide Reduction in Molten Fluoride Media.
Authors: Ciumag M. , Gibilaro M. , Massot L. , Laucournet R. , Chamelot P.
Published: June 2016

Galvanostatic electrolysis of Nd2O3—CuO pellets in molten LiF—CaF2 eutectics containing Li2O between 900 and 1040 °C leads to the formation of metallic neodymium in the form of liquid Cu—Nd alloys.
ChemInform Abstract: A Bismuth‐Halide Double Perovskite with Long Carrier Recombination Lifetime for Photovoltaic Applications.
Authors: Slavney Adam H. , Hu Te , Lindenberg Aaron M. , Karunadasa Hemamala I.
Published: June 2016

Cs2AgBiBr6 is prepared by reaction of CsBr, BiBr3, and AgBr in 9 M HBr solution (110 °C, 2 h, 59% yield).
ChemInform Abstract: Pyrrolidine Modified PANF Catalyst for Asymmetric Michael Addition of Ketones to Nitrostyrenes in Aqueous Phase.
Authors: Du Jianguo , Shuai Bin , Tao Minli , Wang Guangwei , Zhang Wenqin
Published: June 2016

Three chiral pyrrolidine functionalized polyacrylonitrile fiber catalysts are designed, prepared, and evaluated for their catalytic performance in asymmetric Michael addition of ketones to nitrostyrenes in water.
ChemInform Abstract: General Copper‐Catalyzed Coupling of Alkyl‐, Aryl‐, and Alkynylaluminum Reagents with Organohalides.
Authors: Shrestha Bijay , Thapa Surendra , Gurung Santosh K. , Pike Ryan A. S. , Giri Ramesh
Published: June 2016

A wide range of cross‐coupled products are obtained by reactions of aryl‐, alkyl‐ and alkynylaluminium reagents with aryl‐, heteroaryl halides and vinyl bromides.