bluuebunny/crossref_metadata_2025 huggingface dataset:
Enzymes as Enhancers for the Biodegradation of Synthetic Polymers in Wastewater
Authors: Haernvall Karolina , Zitzenbacher Sabine , Biundo Antonino , Yamamoto Motonori , Schick Michael Bernhard , Ribitsch Doris , Guebitz Georg M.
Published: November 2017

Synthetic polyesters are today the second‐largest class of ingredients in household products and are entering wastewater treatment plants (WWTPs) after product utilization. One approach to improve polymer biodegradation in wastewater would be to complement current processes with polyester‐hydrolyzing enzymes and their microbial producers. In this study, the hydrolysis of poly(oxyethylene terephthalate) polymer by hydrolases from wastewater microorganisms was investigated in vitro and under realistic WWTP conditions. An esterase and a cutinase from Pseudomonas pseudoalcaligenes and a lipase from Pseudomonas pelagia were heterologously expressed in Escherichia coli BL21‐Gold(DE3) and were purified by a C‐terminal His6 tag. The hydrolases were proven to hydrolyze the polymer effectively, which is a prerequisite for further biodegradation. The hydrolases maintained high activity up to 50 % upon lowering the temperature from 28 to 15 °C to mimic WWTP conditions. The hydrolases were also not inhibited by the wastewater matrix. Polyester‐hydrolyzing enzymes active under WWTP conditions and their microbial producers thus have the potential to improve biological treatment of wastewater rich in synthetic polymers.
Simultaneous laparoscopic cholecystectomy and transabdominal preperitoneal hernioplasty: two case reports evaluate the safety and surgical complications
Authors: Arafat Shawqi , Alsabek Mhd Belal
Published: November 2017

Key Clinical Message

The safety of combining transabdominal preperitoneal (TAPP) hernioplasty and cholecystectomy in one laparoscopic surgery is still for many years questionable. We report two cases describing the safety and discussing the main concerns regarding the complications. As there are only few cases discuss this kind of combination, we aim to further clarify this subject to provide the best practice for our patients.
Ambient Pressure Photoelectron Spectroscopy: Opportunities in Catalysis from Solids to Liquids and Introducing Time Resolution
Authors: Roy Kanak , Artiglia Luca , van Bokhoven Jeroen A.
Published: November 2017

Photoelectron spectroscopy is an excellent technique to explore chemically complex systems in catalysis. However, due to a small mean free path of photoelectrons in gas, liquid, and solid media, the study of the gas–solid, liquid–gas, solid–liquid interfaces, as well as liquid homogeneous systems are a serious challenge. With differentially pumped analyzers this limitation ceases to exist and no longer restricts photoelectron spectroscopy only to ultra‐high vacuum conditions. Presently, photoemission studies at tens of mbar of pressure are possible. To reach atmospheric pressure and even higher, membrane‐covered closed cells have been developed. Graphene membranes are impermeable to molecules and almost transparent to photoelectrons. They are used as a pressure barrier between the enclosed cell at atmospheric pressure and the electron analyzer at vacuum while allowing transmission of photoelectrons. By accessing to atmospheric pressure range, with this kind of cell, photoemission studies will become a versatile in situ and operando tool for catalysis. Studies involving liquids in static conditions are an important aspect in this direction, which can be extended to homogeneous catalytic systems. Liquids are presently accessible using micro‐jets. Another aspect which is of paramount interest to investigate catalysts is time resolution. By improving the time resolution of photoemission measurements to the sub‐second regime it is possible to follow the kinetic changes that are crucial of a catalytic reaction, the changes that occur during catalyst pretreatment and activation, and notably to differentiate active species from spectator ones, which may be the dominating species in a classical experiment.
Pd‐Catalyzed versus Uncatalyzed, PhI(OAc)2‐Mediated Cyclization Reactions of N6‐([1,1′‐Biaryl]‐2‐yl)Adenine Nucleosides
Authors: Satishkumar Sakilam , Poudapally Suresh , Vuram Prasanna K. , Gurram Venkateshwarlu , Pottabathini Narender , Sebastian Dellamol , Yang Lijia , Pradhan Padmanava , Lakshman Mahesh K.
Published: November 2017

The front cover artwork for Issue 21/2017 is provided by the Lakshman Group at The City College of New York (USA). The image shows the beautifully delicate architecture of Hawa Mahal, in Jaipur, as a symbol of the delicate balance of various factors in the described C−N bond formation of N6‐([1,1′‐biaryl]‐2‐yl)adenine nucleosides promoted by PhI(OAc)2 under both Pd‐mediated and uncatalyzed reaction conditions, which ultimately leads to relatively complex product structures. See the Full Paper itself at https://doi.org/10.1002/cctc.201700918.
Reduced Shuttle Effect of Lithium−sulfur Batteries by using a Simple Graphite‐Modified Separator with a Preformed SEI Film
Authors: Zeng Pan , Huang Liwu , Han Yamiao , Zhang Xinling , Zhang Ruixue , Chen Yungui
Published: November 2017

Lithium−sulfur (Li−S) batteries, which possess a high theoretical capacity of 1675 mAh g−1 and energy density of 2600 Wh kg−1, are regarded as appealing candidates for next‐generation power storage systems. However, poor electrochemical performance, mainly attributed to polysulfide diffusion, obstructs their practical application. Herein, a simple graphite‐modified separator with a preformed solid electrolyte interphase (SEI) is first fabricated to suppress the polysulfide shuttle. Particularly, the formed SEI film on the graphite surface inhibits the graphite exfoliation caused by co‐intercalation of solvents. Thus, the stable graphite layer with a preformed SEI can function as an effective physical barrier to suppress the polysulfide shuttle and enhance the utilization of the trapped active material. As a result, the cell using the graphite‐modified separator exhibits a high capacity of 698 mAh g−1 (0.2 C) after 100 cycles with a low capacity decay of 0.13 % per cycle. Even under relatively high sulfur loading (2.5 mg cm−2), it shows a reversible capacity of 519 mAh g−1 after 200 cycles.
Simultaneous Electrospinning and Electrospraying: Fabrication of a Carbon Nanofibre/MnO/Reduced Graphene Oxide Thin Film as a High‐Performance Anode for Lithium‐Ion Batteries
Authors: Wang Fan , Cai Jianxin , Yu Ji , Li Chao , Yang Zhenyu
Published: November 2017

Rational fabrication of flexible thin‐film electrodes with superior electrochemical performance is challenging now in consumer electronics miniaturization. In this work, we combine electrospinning with electrospraying in a simultaneous process to achieve the CNFs/MnO/rGO composite film electrodes (CNFs=carbon nanofibres; rGO=reduced graphene oxide) for lithium‐ion batteries. For the as‐obtained thin‐film electrode, the 2D reduced graphene sheets are dispersed on each of the 1D CNFs/MnO composite filaments, in which the nanofibres and rGO nanosheets can form interconnected morphologies simultaneously. The thin‐film electrodes with enhanced electrical conductivity and flexibility could efficiently accommodate the volume changes of MnO particles by the very elastic buffer space. As expected, the composite electrode exhibits a high discharge capacity of 1118 mAh g−1 at 0.1 A g−1, and then back to 0.1 A g−1 after 80 cycles, the capacity retention is still up to 98 %; at high rates (e. g. 5 A g−1), the composite is still able to maintain a high reversible capacity of 574 mAh g−1 after 3000 cycles with a significant Coulombic efficiency of 99 %. This is the best specific capacity at 5 A g−1 and longest cycling life reported for MnO thin‐film anodes. In addition, the technique provides a facile path to combine 1D fibres/2D nanosheets layer‐by‐layer in a composite film with tunable fibre diameter. This is the first time that the fabrication of 1D CNFs/MnO fibres and 2D rGO sheet network film electrodes via simultaneous electrospinning and electrospraying methods has been reported.
Quantitative structure‐property relationship modeling of small organic molecules for solar cells applications
Authors: Tortorella Sara , De Angelis Filippo , Cruciani Gabriele
Published: November 2017

Despite the need of a reliable technology for solar energy harvesting, research on new materials for third generation photovoltaics is slowed down by the diffuse use of trial and error rather than rational material design approaches. The proposed study investigates the use of alternative strategies to material discovery inspired by drug design and molecular modeling. In particular, training set and test set (for validation purposes) comprising well‐known small molecule‐bulk heterojunction organic photovoltaics were built. Molecules were characterized by semiempirical calculated and 3D molecular interaction fields–based descriptors. Then partial least squares algorithm was applied to rationalize structure‐photovoltaic activity relationships, and coefficients were investigated to clarify contributions played by the different molecular properties to the final performance. In addition, a photovoltaic desirability function (PhotD) was also proposed as alternative and versatile novel tool for ranking potential candidates. The partial least squares model and PhotD function were both internally and externally validated demonstrating their ability in estimating new candidates performances. The proposed approach demonstrates that, in the context of computational materials science, chemometrics and molecular modeling tools could effectively boost the discovery of novel promising candidates for photovoltaic application.
Blessing of randomness against the curse of dimensionality
Authors: Kucheryavskiy Sergey
Published: November 2017

Modern hyperspectral images, especially acquired in remote sensing and from on‐field measurements, can easily contain from hundreds of thousands to several millions of pixels. This often leads to a quite long computational time when, eg, the images are decomposed by Principal Component Analysis (PCA) or similar algorithms. In this paper, we are going to show how randomization can tackle this problem. The main idea is described in detail by Halko et al in 2011 and can be used for speeding up most of the low‐rank matrix decomposition methods. The paper explains this approach using visual interpretation of its main steps and shows how the use of randomness influences the speed and accuracy of PCA decomposition of hyperspectral images.
Automated data mining of secondary ion mass spectrometry spectra
Authors: Tuccitto Nunzio
Published: November 2017

Time of flight secondary ion mass spectrometry (ToF‐SIMS) allows the reliable analytical determination of organic and polymeric materials. Since a typical raw data may contain thousands of peaks, the amount of information to deal with is accordingly large, so that data reduction techniques become indispensable for extracting the most significant information from the given dataset. Here, the use of the wavelet‐principal component analysis–based signal processing of giant raw data acquired during ToF‐SIMS experiments is presented. The proposed procedure provides a straightforwardly “manageable” dataset without any binning procedure neither detailed integration. By studying the principal component analysis results, detailed and reliable information about the chemical composition of polymeric samples have been gathered.
Phosphorescence Tuning through Heavy Atom Placement in Unsymmetrical Difluoroboron β‐Diketonate Materials
Authors: Liu Tiandong , Zhang Guoqing , Evans Ruffin E. , Trindle Carl O. , Altun Zikri , DeRosa Christopher A. , Wang Fang , Zhuang Meng , Fraser Cassandra L.
Published: November 2017

Difluoroboron β‐diketonates (BF2bdks) show both fluorescence (F) and room‐temperature phosphorescence (RTP) when confined to a rigid matrix, such as poly(lactic acid). These materials have been utilized as optical oxygen sensors (e.g., in tumors, wounds, and cells). Spectral features include charge transfer (CT) from the major aromatic donor to the dioxaborine acceptor. A series of naphthyl–phenyl dyes (BF2nbm) (1–6) were prepared to test heavy‐atom placement effects. The BF2nbm dye (1) was substituted with Br on naphthyl (2), phenyl (3), or both rings (4) to tailor the fluorescence/phosphorescence ratio and RTP lifetime—important features for designing O2 sensing dyes by means of the heavy atom effect. Computational studies identify the naphthyl ring as the major donor. Thus, Br substitution on the naphthyl ring produced greater effects on the optical properties, such as increased RTP intensity and decreased RTP lifetime compared to phenyl substitution. However, for electron‐donating piperidyl‐phenyl dyes (5), the phenyl aromatic is the major donor. As a result, Br substitution on the naphthyl ring (6) did not alter the optical properties significantly. Experimental data and computational modeling show the importance of Br position. The S1 and T1 states are described by two singly occupied MOs (SOMOs). When both of these SOMOs have substantial amplitude on the heavy atom, passage from S1 to T1 and emission from T1 to S0 are both favored. This shortens the excited‐state lifetimes and enhances phosphorescence.
Efficient endo Cycloisomerization of Terminal Alkynols Catalyzed by a New Ruthenium Complex with 8‐(Diphenylphosphino)quinoline Ligand and Mechanistic Investigation
Authors: Cai Tao , Yang Yu , Li Wei‐Wei , Qin Wen‐Bing , Wen Ting‐Bin
Published: November 2017

Several new ruthenium complexes supported by the P,N‐donor ligand 8‐(diphenylphosphino)quinoline (DPPQ) were synthesized, including [RuCl2(DPPQ)2] (1), [Ru(μ‐Cl)(DPPQ)2]2(BPh4)2 (2), and [RuCl(DPPQ)2Py](BF4) (3). Complex 2, with only 1 mol % loading, was found to be catalytically active for the endo cycloisomerization of various terminal alkynols to endo‐cyclic enol ethers in moderate to excellent yields. In particular, the 7‐ and 8‐endo heterocyclization can be achieved efficiently to give the seven‐membered 3‐benzoxepine and eight‐membered 3‐benzo[d]oxocine derivatives. The stoichiometric reactions of 2 with various alkynol substrates have been carried out to investigate the mechanism, which led to a series of seven‐, six‐, and five‐membered oxacyclocarbene ruthenium complexes including [RuCl(DPPQ)2{=CCH2C6H4CH2CH2O}](BPh4) (12) and [RuCl(DPPQ)2{=CCH2(CH2)nCH2O}](BPh4) (n=3, 12′; n=2, 13; n=1, 14). The quantitative transformation of oxacyclocarbene 12 into catalyst 2 and 3‐benzoxepine 5 a as well as the efficient catalytic activity of 12 for the endo‐cyclization of 2‐(2‐ethynylphenyl)ethanol (4 a) demonstrated that 12 is a key intermediate involved in the catalytic cycle. Moreover, comparative studies on the modeling reactions and catalytic activity of the series of oxacyclocarbene complexes indicated that the different catalytic activity of 2 for the endo‐cycloisomerization of different types of alkynols can be related to the reactivity of the respective ruthenium oxacyclocarbene intermediates.
Well‐Defined Chiral Copper NHC Complex in the Asymmetric Conjugated β‐Borylation and One‐Pot Metathesis‐Asymmetric β‐Borylation Reactions
Authors: Jana Anupam , Trzybiński Damian , Woźniak Krzysztof , Grela Karol
Published: November 2017

Highly stereoselective conjugate β‐borylation, using a new chiral NHC‐based copper catalyst, has been achieved. The chiral NHC copper complex was prepared in gram scale and showed high enantioselectivity and activity (up to 10 000 turnovers at 100 ppm of catalyst loading). This method was employed in the synthesis of a chiral β‐borylated ester from simple unconjugated alkenes though an unprecedented one‐pot cross metathesis‐asymmetric borylation sequence.
Preparation and Characterization of P2BCh Ring Systems (Ch=S, Se) and Their Reactivity with N‐Heterocyclic Carbenes
Authors: Graham Cameron M. E. , Millet Clément R. P. , Price Amy N. , Valjus Juuso , Cowley Michael J. , Tuononen Heikki M. , Ragogna Paul J.
Published: November 2017

Four‐membered rings with a P2BCh core (Ch=S, Se) have been synthesized by the reaction of phosphinidene chalcogenide (Ar*P=Ch) and phosphaborene (Mes*P=BNR2). The mechanistic pathways towards these rings are explained by detailed computational work that confirmed the preference for the formation of P−P, not P−B, bonded systems, which seems counterintuitive given that both phosphorus atoms contain bulky ligands. The reactivity of the newly synthesized heterocycles, as well as that of the known (RPCh)n rings (n=2, 3), was probed by the addition of N‐heterocyclic carbenes, which revealed that all investigated compounds can act as sources of low‐coordinate phosphorus species.
A Magic Ratio Rule for Beginners: A Chemist's Guide to Quantum Interference in Molecules
Authors: Lambert Colin J. , Liu Shi‐Xia
Published: November 2017

This Concept article will give a glimpse into chemical design principles for exploiting quantum interference (QI) effects in molecular‐scale devices. Direct observation of room temperature QI in single‐molecule junctions has stimulated growing interest in fabrication of tailor‐made molecular electronic devices. Herein, we outline a new conceptual advance in the scientific understanding and technological know‐how necessary to control QI effects in single molecules by chemical modification. We start by discussing QI from a chemical viewpoint and then describe a new magic ratio rule (MRR), which captures a minimal description of connectivity‐driven charge transport and provides a useful starting point for chemists to design appropriate molecules for molecular electronics with desired functions. The MRR predicts conductance ratios, which are solely determined by QI within the core of polycyclic aromatic hydrocarbons (PAHs). The manifestations of QI and related quantum circuit rules for materials discovery are direct consequences of the key concepts of weak coupling, locality, connectivity, mid‐gap transport and phase coherence in single‐molecule junctions.
Construction of Zeolite‐Like Cluster Organic Frameworks from 3 d–4 d/3 d–3 d Heterometallic Supertetrahedral Secondary Building Units: Syntheses, Structures, and Properties
Authors: Lin Li‐Dan , Deng Chu‐Chu , Zhao D. , Li Xin‐Xiong , Zheng Shou‐Tian
Published: November 2017

Two zeolite‐like cluster organic frameworks based on Cd‐Cu/Mn‐Cu heterometallic supertetrahedral secondary building units have been successfully constructed under solvothermal conditions, namely, Cu[Cd4Cu6(L)4(H2O)18](Ac)9⋅DMA⋅3 H2O (1), and Cu[Mn4Cu6(L)4(Ac)3(H2O)12](Ac)6⋅CH3CN⋅13 H2O (2), where H3L=2‐(hydroxymethyl)‐2‐(pyridin‐4‐yl)‐1,3‐propanediol, Ac=CH3COO−, DMA=N,N′‐dimethylacetamide. Single‐crystal X‐ray structural analysis reveals that both 1 and 2 exhibit 3‐dimensional zeolite‐like architectures with similar 4‐connected components, but possess definitely different topologies of diamondoid (dia) and uncommon lonsdaleite (lon), respectively. 1 and 2 represent the first cases of zeolite‐like cluster organic frameworks containing Cd‐Cu/Mn‐Cu heterometallic supertetrahedral secondary building units. Furthermore, the magnetic properties and porous nature of 1 and 2 were also studied.
Exponential Activation of Carbonic Anhydrase by Encapsulation in Dynameric Host Matrices with Chiral Discrimination
Authors: Zhang Yan , Supuran Claudiu T. , Barboiu Mihail
Published: November 2017

Herein an unexpected exponential activation of bovine carbonic anhydrase (bCA) in aqueous solutions in the presence of dynameric host matrices is reported. Successive experiments confirmed the important role of dynamic imine exchange within the dynameric host structures for direct enzyme activation. This allows for optimal encapsulation of the guest enzyme, whereas the presence of external proton‐sponge amino groups is less important. Non‐exchanging polymeric sec‐amine congeners formed from imine reduction of dynameric structures show no obvious activation on bCA. Although the dynamers synthesized from diamino chiral‐pair precursors displayed similar activation constants toward bCA, different activation delay times were observed from these two dynamers of opposite optical activity. The circular dichroism (CD) spectra demonstrate selective structural changes in the secondary structure of bCA upon dynameric encapsulation in aqueous solution. The different interaction molds observed in CD spectra for the dynamers with opposite chirality explain the longer activation time required for one of the dynamers.
Structural Insights from 59Co Solid‐State NMR Experiments on Organocobalt(I) Catalysts
Authors: Burgess Kevin M. N. , Widdifield Cory M. , Xu Yang , Leroy César , Bryce David L.
Published: November 2017

A series of fumarate‐based organocobalt(I) [CoCp(CO)(fumarate)] catalysts is synthesized and characterized by X‐ray crystallography, multinuclear (13C and 59Co) solid‐state NMR spectroscopy, and 59Co NQR spectroscopy. Given the dearth of 59Co solid‐state NMR studies on CoI compounds, the present work constitutes the first systematic characterization of the 59Co electric field gradient and chemical shift tensors for a series of cobalt complexes in this oxidation state. Using X‐ray crystallography, the molecular geometry about the CoI centre is found to be nearly identical in all compounds studied herein. Owing to the 59Co nucleus’ large chemical shift range, solid‐state NMR experiments are found to be able to detect small structural differences between the individual organocobalt(I) compounds. With the aid of density functional theory calculations on these complexes, it is shown that the 59Co chemical shift anisotropy and the 59Co quadrupolar coupling constant are both extremely sensitive gauges of the Fu‐Co‐Cp bond angle, providing a link between these 59Co NMR observables and the catalysts’ structures.
ELISA for Molluscum Contagiosum Virus
Authors: Sherwani Subuhi , Chowdhury Mohammed , Bugert Joachim J.
Published: November 2017

Molluscum contagiosum virus (MCV) is a common skin pathogen of children and young adults. Infection with MCV causes benign skin tumors in children and young adults and is mostly self‐limiting. In contrast to orthopoxviruses, MCV infections tend to take a subacute clinical course but may persist for up to 12 months. Current numbers for MCV seroprevalence in different geographical areas are based on a variety of historical serological methods from complement fixation assays to MCV ELISAs based on purified MCV virions and MC133 antigen expressed in a Semliki Forest Virus expression system. A standardized ELISA for the assessment of MCV seroprevalence would be useful to determine global MCV seroprevalence. The methods described show that polypeptides derived from MCV open reading frames MC084 (residues V123 to R230 and V33 to G117), mc133 (residues M1 to N370), and glutathione S‐transferase (GST)‐H3L (residues I142 to W251) expressed in E. coli RIL+ as GST fusion proteins can be used to assess antibody binding in a GST capture ELISA. We show how the ELISA can be used to screen a panel of patient sera previously characterized with the mc084 V123‐R230 ELISA. © 2017 by John Wiley & Sons, Inc.
Estimands: A More Strategic Approach to Study Design and Analysis
Authors: Akacha Mouna , Kothny Wolfgang
Published: November 2017

Do we always precisely define the treatment effects that our clinical trial will estimate? Our tenet is that this is not always done, or is done inadequately. This lack of clarity can result in a misalignment among trial objectives, trial design, and statistical methods. We will discuss these challenges and present an improved framework using estimands that is proposed in a draft International Council for Harmonization (ICH) E9 addendum.
Complete Depolymerization and Repolymerization of a Sugar Poly(orthoester)
Authors: Li Lingyao , Maiti Sampa , Thompson Nicole A. , Milligan Ian J. , Du Wenjun
Published: November 2017

The capability of a polymer to depolymerize, regenerating its original monomer for further polymerization, is very attractive in terms of sustainability. Recently discovered sugar poly(orthoesters) are an important class of glycopolymer. The high sensitivity of the backbone orthoester linkage toward acidolysis provides a valuable model to study the depolymerization. Herein, a sugar poly(orthoester) is shown to be completely depolymerized under acidic conditions. Interestingly, instead of the original monomer, the depolymerization gave a stable cyclic product (1,6‐anhydro glucopyranose) in most cases, which was kinetically and thermodynamically favored. However, this pathway could be inhibited by chemically deactivating a key intermediate and thus favoring the formation of the original monomer. Efficient repolymerizaton of the regenerated monomer is also demonstrated.
Gradient correction and Bohm potential for two‐ and one‐dimensional electron gases at a finite temperature
Authors: Moldabekov Zh.A. , Bonitz M. , Ramazanov T.S.
Published: November 2017

From the static polarization function of electrons in the random phase approximation, the quantum Bohm potential for the quantum hydrodynamic description of electrons and the density gradient correction to the Thomas–Fermi free energy at a finite temperature for the two‐ and one‐dimensional cases are derived. The behaviour of the Bohm potential and of the density gradient correction as a function of the degeneracy parameter is discussed. Based on recent developments in the fluid description of quantum plasmas, the Bohm potential for the high‐frequency domain is presented.
Dynamic preferential allocation to arbuscular mycorrhizal fungi explains fungal succession and coexistence
Authors: Bachelot Benedicte , Lee Charlotte T.
Published: November 2017

Evidence accumulates about the role of arbuscular mycorrhizal (AM) fungi in shaping plant communities, but little is known about the factors determining the biomass and coexistence of several types of AM fungi in a plant community. Here, using a consumer‐resource framework that treats the relationship between plants and fungi as simultaneous, reciprocal exploitation, we investigated what patterns of dynamic preferential plant carbon allocation to empirically‐defined fungal types (on‐going partner choice) would be optimal for plants, and how these patterns depend on successional dynamics. We found that ruderal AM fungi can dominate under low steady‐state nutrient availability, and competitor AM fungi can dominate at higher steady‐state nutrient availability; these are conditions characteristic of early and late succession, respectively. We also found that dynamic preferential allocation alone can maintain a diversity of mutualists, suggesting that on‐going partner choice is a new coexistence mechanism for mutualists. Our model can therefore explain both mutualist coexistence and successional strategy, providing a powerful tool to derive testable predictions.
Analyzing community‐weighted trait means across environmental gradients: should phylogeny stay or should it go?
Authors: Duarte Leandro D. S. , Debastiani Vanderlei J. , Carlucci Marcos B. , Diniz‐Filho José Alexandre F.
Published: November 2017

Functional traits mediate ecological responses of organisms to the environment, determining community structure. Community‐weighted trait means (CWM) are often used to characterize communities by combining information on species traits and distribution. RelatingCWMvariation to environmental gradients allows for evaluating species sorting across the metacommunity, either based on correlation tests or ordinary least squares (OLS) models. Yet, it is not clear if phylogenetic signal in both traits and species distribution affect those analyses. On one hand, phylogenetic signal might indicate niche conservatism along clade evolution, reinforcing the environmental signal in trait assembly patterns. On the other hand, it might introduce phylogenetic autocorrelation to mean trait variation among communities. Under this latter scenario, phylogenetic signal might inflate type I error in analysis relatingCWMvariation to environmental gradients. We explore multiple ways phylogenetic history may influence analysis relatingCWMto environmental gradients. We propose the concept of neutral trait diffusion, which predicts that for a functional traitx,CWMvariation among local communities does not deviate from the expectation thatxevolved according to a neutral evolutionary process. Based on this framework we introduce a graphical tool called neutral trait diffusion representation (NTDR) that allows for the evaluation of whether it is necessary to carry out phylogenetic correction in the trait prior to analyzing the association betweenCWMand environmental gradients. We illustrate theNTDRapproach using simulated traits, phylogenies and metacommunities. We show that even under moderate phylogenetic signal in both the trait used to defineCWMand species distribution across communities,OLSmodels relatingCWMvariation to environmental gradients lead to inflated type I error when testing the null hypothesis of no association betweenCWMand environmental gradient. To overcome this issue, we propose a phylogenetic correction forOLSmodels and evaluate its statistical performance (type I error and power). Phylogeny‐correctedOLSmodels successfully control for type I error in analysis relatingCWMvariation to environmental gradients but may show decreased power. Combining the exploratory tool ofNTDRand phylogenetic correction in traits, when necessary, guarantees more precise inferences about the environmental forces driving trait‐mediated species sorting across metacommunities.
A Polyselenide with a Novel Se78– Unit: the Structure of Sr19–xPbxGe11Se44 with x = 5.0 and 6.4
Authors: Assoud Abdeljalil , Kleinke Holger
Published: November 2017

An unprecedented, planar Se78– unit with a threefold rotation axis was discovered in the new polyselenide Sr19–xPbxGe11Se44. Sr12.6Pb6.4Ge11Se44 crystallizes in the non‐centrosymmetric hexagonal space group P63 with unit cell dimensions of a = b = 19.9867(2) Å, c = 12.0546(1) Å, V = 4170.28(7) Å3, with two formula units per cell. Its structure contains isolated [GeSe4] tetrahedra, [Ge2Se7] dimers, and a novel, planar propeller‐shaped Se78– unit. The latter is unprecedented, but reminiscent of the isoelectronic pyramidal Se78– and I7– units. It consists of a central Se atom, to which three Se2 pairs with a short Se–Se bond are attached through a longer Se–Se distance, resulting in a central Se atom featuring 120° bond angles, and bridging Se atoms featuring an approximately linear coordination with a 179° bond angle. It can thus be written as [Se(Se2)3]8–. We characterized this unit using Gaussian calculations in comparison to the pyramidal Se78– unit, which may be described also as [Se(Se2)3]8–. The solid‐state material is a black semiconductor with an optical band‐gap of 1.8 eV, which supports the assignment of this charge.
Cycloheptatrienyl Cyclopentadienyl Titanium Phosphane Ligands in Palladium‐Catalyzed Suzuki–Miyaura Cross‐Coupling Reactions
Authors: Tröndle Sabrina , Tagne Kuate Alain C. , Freytag Matthias , Jones Peter G. , Tamm Matthias
Published: November 2017

The reaction of the cycloheptatrienyl cyclopentadienyl (Cht‐Cp) titanium sandwich complexes [(η7‐C7H7)Ti(η5‐C5R5)] (R = H, Me) with nBuLi followed by treatment with the chlorophosphanes ClPR′2 (R′ = Cy, tBu) afforded the Cht‐substituted phosphanes [(η7‐C7H6PR′2)Ti(η5‐C5R5)] (R = H, Me; R′ = Cy, tBu). Together with their previously reported Cp‐substituted analogues [(η7‐C7H7)Ti(η5‐C5H4PR2)] (R = Cy, tBu), these complexes were employed as ancillary phosphane ligands in palladium‐catalyzed Suzuki–Miyaura coupling between sterically encumbered aryl bromides and aryl boronic acids. The unusually short reaction times indicated rapid generation of catalytically active Pd0 species, and the reaction of Pd(OAc)2 with an excess of the phosphorus ligands afforded linear bis‐phosphane palladium(0) complexes. These reactions gave no indication of phosphane oxide formation, and it is supposed that the Cht‐Cp titanium sandwich moiety serves as an integrated reducing agent. Accordingly, the reaction of [(η7‐C7H7)Ti(η5‐C5M5)] with Pd(OAc)2 or Ag(OAc) resulted in a three‐electron redox reaction with formation of the half‐sandwich complex [(η5‐C5Me5)Ti(OAc)3] together with 7,7′‐bi‐1,3,5‐cycloheptatriene (ditropyl) and elemental Pd or Ag metal. On reaction with silver(I) trifluoromethanesulfonate, a four‐electron redox process furnished the tropylium titanate complex [C7H7][(η5‐C5Me5)Ti(OTf)4].
Sequential Copper‐Catalyzed Sonogashira Coupling, Hydroamination and Palladium‐Catalyzed Intramolecular Direct Arylation: Synthesis of Azepino‐Fused Isoindolinones
Authors: Saini Hitesh Kumar , Nandwana Nitesh Kumar , Dhiman Shiv , Rangan Krishnan , Kumar Anil
Published: November 2017

A sequential copper‐catalyzed Sonogashira coupling followed by an intramolecular hydroamination and palladium‐catalyzed intramolecular direct arylation reaction was developed to provide a convenient and modular approach for the synthesis of useful azepino‐fused isoindolinones. Nineteen azepino‐fused isoindolinones were prepared in moderate to high (22–90 %) yields. The developed protocol tolerated various functional groups and involved the formation of one carbon–nitrogen and two carbon–carbon bonds in a one‐pot fashion. The palladium‐catalyzed intramolecular direct arylation step involved formation of an unusual eight‐membered palladacycle.
Cell‐free production of pore forming toxins: Functional analysis of thermostable direct hemolysin from Vibrio parahaemolyticus
Authors: Dondapati Srujan Kumar , Wüstenhagen Doreen A , Strauch Eckhard , Kubick Stefan
Published: November 2017

The pore forming characteristic of TDH1 and TDH2 variants of thermostable direct hemolysin (TDH), a major toxin involved in the pathogenesis of Vibrio parahaemolyticus, was studied on a planar lipid bilayer painted over individual picoliter cavities containing microelectrodes assembled in a multiarray. Both proteins formed pores upon insertion into the lipid bilayer which was shown as a shift in the conductance from the baseline current. TDH2 protein was able to produce stable currents and the currents were influenced by external factors like concentration, type of salt and voltage. The pore currents were influenced and showed a detectable response in the presence of polymers which makes them suitable for biotechnology applications.
Quantitative differentiation of whole smoke solution‐induced mutagenicity in the mouse lymphoma assay
Authors: Guo Xiaoqing , Heflich Robert H. , Dial Stacey L. , De Mamata , Richter Patricia A. , Mei Nan
Published: November 2017

In vitro genotoxicity dose–response data have been investigated for their utility in modeling and assessing potential differences in mutagenic responses between machine‐generated whole smoke solutions (WSSs) from combusted cigarette tobacco products. Our previous study observed that potency ranking by benchmark dose (BMD) analysis was a useful modeling approach for quantitative assessment of differences between the mutagenicity of several structurally diverse chemical constituents of cigarette smoke. To follow‐up on these observations, we used the mouse lymphoma assay (MLA) to evaluate the mutagenicity of WSSs prepared from two commercial cigarettes smoked under two different smoking machine regimens. L5178Y cells were exposed to ≥5 concentrations of each WSS for 4 hr ± S9 activation. S9 reduced the cytotoxicity and enhanced the mutagenicity of the WSSs. The resulting S9‐mediated mutagenicity dose–responses were compared between test articles using BMD analysis, the lowest dose exceeding the Global Evaluation Factor, the no observed or lowest observed genotoxic effect level, and the mutagenic potency. The BMD10, BMD50, BMD100, and BMD200, indicating a 10%, 50%, 100%, or 200% increase in the background mutant frequency, respectively, were calculated using the PROAST software package. Overall, the quantitative approaches resulted in a similar rank order of mutagenic potency for the MLA tested WSSs, with potency increasing with the level of tar. The BMD approach using covariate analysis produced the most informative comparisons. Differences in potency were associated with the number of cigarettes smoked, the cigarette product smoked, and the smoking machine protocol used to prepare the sample. Under the conditions of this study, these results suggest that our hypothesis of modeling MLA data using the BMD approach to quantitatively discriminate between the mutagenic potential of WSSs from combustible cigarettes might be an useful method. Environ. Mol. Mutagen. 59:103–113, 2018. Published 2017. This article is a US Government work and is in the public domain in the USA.
Effects of exposure to winter oilseed rape grown from thiamethoxam-treated seed on the red mason bee Osmia bicornis
Authors: Ruddle Natalie , Elston Charlotte , Klein Olaf , Hamberger Anja , Thompson Helen
Published: November 2017

There has been increasing interest in the effects of neonicotinoid insecticides on wild bees. In solitary bee species the direct link between each individual female and reproductive success offers the opportunity to evaluate effects on individuals. The present study investigated effects of exposure to winter oilseed rape grown from thiamethoxam-treated seed on reproductive behavior and output of solitary red mason bees (Osmia bicornis) released in 6 pairs of fields over a 2-yr period and confined to tunnels in a single year. After adjustment to the number of females released, there was significantly lower production of cells and cocoons/female in tunnels than in open field conditions. This difference may be because of the lack of alternative forage within the tunnels. Under open field conditions, palynology of the pollen provisions within the nests demonstrated a maximum average of 31% oilseed rape pollen at any site, with Quercus (oak) contributing up to 86% of the pollen. There were no significant effects from exposure to oilseed rape grown from thiamethoxam-treated seed from nest establishment through cell production to emergence under tunnel or field conditions. Environ Toxicol Chem 2018;37:1071–1083. © 2017 SETAC
An integrative approach to assess X‐chromosome inactivation using allele‐specific expression with applications to epithelial ovarian cancer
Authors: Larson Nicholas B. , Fogarty Zachary C. , Larson Melissa C. , Kalli Kimberly R. , Lawrenson Kate , Gayther Simon , Fridley Brooke L. , Goode Ellen L. , Winham Stacey J.
Published: November 2017

X‐chromosome inactivation (XCI) epigenetically silences transcription of an X chromosome in females; patterns of XCI are thought to be aberrant in women's cancers, but are understudied due to statistical challenges. We develop a two‐stage statistical framework to assess skewed XCI and evaluate gene‐level patterns of XCI for an individual sample by integration of RNA sequence, copy number alteration, and genotype data. Our method relies on allele‐specific expression (ASE) to directly measure XCI and does not rely on male samples or paired normal tissue for comparison. We model ASE using a two‐component mixture of beta distributions, allowing estimation for a given sample of the degree of skewness (based on a composite likelihood ratio test) and the posterior probability that a given gene escapes XCI (using a Bayesian beta‐binomial mixture model). To illustrate the utility of our approach, we applied these methods to data from tumors of ovarian cancer patients. Among 99 patients, 45 tumors were informative for analysis and showed evidence of XCI skewed toward a particular parental chromosome. For 397 X‐linked genes, we observed tumor XCI patterns largely consistent with previously identified consensus states based on multiple normal tissue types. However, 37 genes differed in XCI state between ovarian tumors and the consensus state; 17 genes aberrantly escaped XCI in ovarian tumors (including many oncogenes), whereas 20 genes were unexpectedly inactivated in ovarian tumors (including many tumor suppressor genes). These results provide evidence of the importance of XCI in ovarian cancer and demonstrate the utility of our two‐stage analysis.
Endoscopic endonasal surgery for pituitary adenomas extending to the oculomotor cistern
Authors: Taniguchi Masaaki , Nakai Tomoaki , Kimura Hidehito , Fujita Yuichi , Uozumi Yoichi , Kohta Masaaki , Kohmura Eiji
Published: November 2017

Background

Extension of a pituitary adenoma to the oculomotor cistern harbors the risk of oculomotor nerve impairment and further extension into the interpeduncular cistern. The role of endoscopic endonasal surgery for those lesions was investigated.

Methods

The medical records were retrospectively analyzed. Attention was paid to the oculomotor nerve function and removal rate of the tumor within the oculomotor and interpeduncular cisterns.

Results

Six patients were eligible for the study, including 2 with oculomotor nerve palsy. The tumor from the oculomotor and interpeduncular cistern was removed in all except on one side of the case with bilateral tumor extension. The oculomotor nerve palsy demonstrated partial recovery in both cases during the 3‐month follow‐up.

Conclusion

The pituitary adenoma extending to the oculomotor cistern can be removed under the endoscope. Improvement of oculomotor nerve palsy can be achieved, and further tumor extension into the interpeduncular cistern can be prevented.
Association of total cholesterol, low‐density lipoprotein cholesterol, and non‐high‐density lipoprotein cholesterol with atherosclerotic cardiovascular disease and cancer in a Chinese male population
Authors: Guan Xu‐Min , Wu Shou‐Ling , Yang Xiao‐Lei , Han Xu , Yang Yi‐Heng , Li Xin‐Tao , Bin Waleed Khalid , Yue Du  , Zhan Si‐Yan , Liu Ying , Li Hui‐Hua , Xia Yun‐Long
Published: November 2017

This prospective study included 68,759 Chinese male adults from Kailuan cohort of China who had a standardized medical examination between 2006 and 2007 and were followed up for approximately 8 years until occurrence of ASCVD, cancer or death or until December 31, 2014. Subjects were divided into four categories based on the quartiles of TC, LDL‐C and non‐HDL‐C. Cox regression models were used to estimate hazard ratios (HRs) and their 95% confidence intervals (CIs). During follow‐up, 2,916 males developed ASCVD and 1,884 developed cancer. Compared with the lowest quartile, the upper‐most quartiles of TC, LDL‐C and non‐HDL‐C were all associated with increased ASCVD risk (HR 1.53; HR 1.16; HR 1.55); however, the upper‐most quartiles of TC, LDL‐C and non‐HDL‐C were all negatively associated with cancer (HR0.84; HR 0.82; HR 0.80) and these associations were present after exclusion of incident cancers during the first 4 years of follow‐up. In a word, we report that high TC, LDL‐C and non‐HDL‐C concentrations increased ASCVD incidence in a male population and that these lipid profiles were inversely associated with total cancer and several individual cancers.
FATHER–CHILD PLAY DURING THE PRESCHOOL YEARS AND CHILD INTERNALIZING BEHAVIORS: BETWEEN ROBUSTNESS AND VULNERABILITY
Authors: Ahnert Lieselotte , Teufl Lukas , Ruiz Nina , Piskernik Bernhard , Supper Barbara , Remiorz Silke , Gesing Alexander , Nowacki Katja
Published: November 2017

Play observations with a total of 400 toddlers and preschoolers were videotaped and rated for Intensity and Quality of play with their parents. Parents were asked about perceived stress and personality characteristics (Big 5). Child's motor, cognitive skills, temperament, and internalizing behaviors were assessed. Study 1 investigated the robustness of play across child age and gender, and examined differences between fathers and mothers. Study 2 explored the vulnerability of play with fathers of children born preterm (PT‐fathers) and fathers who had experienced adverse childhoods (AC‐fathers). Study 3 investigated child internalizing behaviors. Intensity of play was maintained almost independently of child age and gender. It was similar for AC‐ and PT‐fathers, and similar to maternal Intensity. In contrast, paternal Quality of play was higher with boys and independent of fathers’ personality and perceived parenting stress whereas maternal Quality of play was higher with girls and linked to mothers’ perceived parenting competence, acceptability of the child, and neuroticism. AC‐fathers scored significantly low on Quality, as did PT‐fathers, but the Quality of their play became better with growing child age, birth weight, and cognitive (but not motor and temperament) scores. Finally, child internalizing behaviors were negatively related to paternal Quality of play.
Disentangling and ranking the influence of multiple stressors on macroinvertebrate communities in a tropical river system
Authors: Mwedzi Tongayi , Zimunya Tapiwa G. , Bere Taurai , Tarakini Tawanda , Mangadze Tinotenda
Published: November 2017

Spatial contrasts in lotic macroinvertebrate assemblages have been ascribed to physico‐chemical, hydrological, and physical habitat conditions. The objective of this study was to disentangle and rank the influences of multiple stressors on benthic macroinvertebrates in the Manyame Catchment, Zimbabwe. Sampling sites were chosen according to their relative location from dams (upstream of dams; 0–10 km downstream of dams; 11–20 km downstream of dams; and >20 km downstream of dams). Benthic macroinvertebrates, physico‐chemical, physical habitat structure; and sediment grain size data were collected at 12 sites in two seasons and paired with long‐term hydrological data. Principal component analysis (PCA) was employed to identify key variables that describe the major sources of variation while minimizing redundancy. Subsequently, generalised linear models (GLMs) were used to investigate the relationship between these key variables and macroinvertebrate community structure and composition. Finally, we used canonical correspondence analysis (CCA) and partial CCA to illustrate the significant relationships from the GLMs across site categories. Macroinvertebrate community structure and composition was significantly driven by four physico‐chemical variables (dissolved oxygen, pH, total nitrogen, total dissolved solids), five hydrological variables (base flow index, low pulse duration, December low flow, small flood timing, extreme low flow duration) and interactions among these variables. Interactions of physico‐chemical conditions and low flows demonstrated that pollution will aggravate impacts of hydrological alteration on biota. Partial CCA showed that physico‐chemical variables had the greatest influence on macroinvertebrate communities. Hence, physico‐chemical conditions remain the most important in structuring macroinvertebrates in the Manyame Catchment. The study highlights the importance of accounting for multiple stress factors in in‐stream ecology.
Charitable Dictators? Determinants of Giving to NGOs in Uganda
Authors: Lehrer Kim , Porter Catherine
Published: November 2017

We play a dictator game in Uganda with students, civil servants and individuals from the private sector. In the game, participants divide a sum of money between themselves and a local charity. In a turning a ‘blind eye’ treatment, participants are first given the choice of knowing the identity of the recipient. Finally, participants are asked whether they wish to additionally donate their own money. Contrary to many experimental findings, the average donation of non‐students (civil servants) is significantly lower than that of students. Very few individuals donate their own money, despite 30 per cent of participants donating the full endowment. Copyright © 2017 John Wiley & Sons, Ltd.