bluuebunny/crossref_metadata_2025 huggingface dataset:
AIM‐1: An Antibiotic‐Degrading Metallohydrolase That Displays Mechanistic Flexibility
Authors: Selleck Christopher , Larrabee James A. , Harmer Jeffrey , Guddat Luke W. , Mitić Nataša , Helweh Waleed , Ollis David L. , Craig Whitney R. , Tierney David L. , Monteiro Pedroso Marcelo , Schenk Gerhard
Published: October 2016

Antibiotic resistance has emerged as a major threat to global health care. This is largely due to the fact that many pathogens have developed strategies to acquire resistance to antibiotics. Metallo‐β‐lactamases (MBL) have evolved to inactivate most of the commonly used β‐lactam antibiotics. AIM‐1 is one of only a few MBLs from the B3 subgroup that is encoded on a mobile genetic element in a major human pathogen. Here, its mechanism of action was characterised with a combination of spectroscopic and kinetic techniques and compared to that of other MBLs. Unlike other MBLs it appears that AIM‐1 has two avenues available for the turnover of the substrate nitrocefin, distinguished by the identity of the rate‐limiting step. This observation may be relevant with respect to inhibitor design for this group of enzymes as it demonstrates that at least some MBLs are very flexible in terms of interactions with substrates and possibly inhibitors.
Precision Construction of 2D Heteropore Covalent Organic Frameworks by a Multiple‐Linking‐Site Strategy
Authors: Qian Cheng , Xu Shun‐Qi , Jiang Guo‐Fang , Zhan Tian‐Guang , Zhao Xin
Published: October 2016

Integrating different kinds of pores into one covalent organic framework (COF) endows it with hierarchical porosity and thus generates a member of a new class of COFs, namely, heteropore COFs. Whereas the construction of COFs with homoporosity has already been well developed, the fabrication of heteropore COFs still faces great challenges. Although two strategies have recently been developed to successfully construct heteropore COFs from noncyclic building blocks, they suffer from the generation of COF isomers, which decreases the predictability and controllability of construction of this type of reticular materials. In this work, this drawback was overcome by a multiple‐linking‐site strategy that offers precision construction of heteropore COFs containing two kinds of hexagonal pores with different shapes and sizes. This strategy was developed by designing a building block in which double linking sites are introduced at each branch of a C3‐symmetric skeleton, the most widely used scaffold to construct COFs with homogeneous porosity. This design provides a general way to precisely construct heteropore COFs without formation of isomers. Furthermore, the as‐prepared heteropore COFs have hollow‐spherical morphology, which has rarely been observed for COFs, and an uncommon staggered AB stacking was observed for the layers of the 2D heteropore COFs.
Stabilizing Superacid Anions: The New [H(S4O13)2]3− Anion in the Crystal Structure of Li3[H(S4O13)2]
Authors: Schindler Lisa Verena , Becker Anna , Wickleder Mathias Siegfried
Published: October 2016

The unique hydrogenium‐bis‐tetrasulfate anion [H(S4O13)2]3− in the crystal structure of Li3[H(S4O13)2] (monoclinic, P21/n (No. 14), Z=2, a=552.46(4) pm, b=939.70(6) pm, c=1876.6(1) pm, β=97.492(3)°, V=965.9(1)⋅106 pm3) is the longest protonated polysulfate chain ever observed. Very strong symmetrical hydrogen bonds are a bold feature of the crystal structure. The protonation of a very weak base such as [S4O13]2− and accordingly the stabilization of the first base of the superacid H2S4O13 is a significant success towards the still elusive polysulfuric acids.
A Dendritic Supramolecular Complex as Uniform Hybrid Micelle with Dual Structure for Bimodal In Vivo Imaging
Authors: Zhang Simin , Zheng Yanmei , Yin Shengyan , Sun Jingzhi , Li Bao , Wu Lixin
Published: October 2016

In this study, a uniform complex dual micelle bearing a gadolinium‐substituted polyoxometalate core, a hydrophobic middle, and a biocompatible organic shell, which exhibits a uniform size and definite molecular weight and chemical composition, is constructed through a simple two‐step process for use as a fluorescence and magnetic resonance imaging (MRI) contrast agent. A paramagnetic polyoxometalate cluster, K13[Gd(β2‐SiW11O39)2], is first encapsulated with a cationic 3‐generation dendron (D‐3) bearing triethylene glycol monomethyl ether terminal groups through ionic substitution. The formed electrostatic complex, (D‐3)13[Gd(β2‐SiW11O39)2] (D‐GdSiW), which displays an ambivalent micellar structure, is then demonstrated to act as a suitable carrier for the uptake of cationic fluorescent dyes, forming a loaded complex. The dye‐loaded complex D‐GdSiW‐D is thus proven to display high relaxivity as a contrast agent, maintaining its structural stability under physiological conditions with low cell cytotoxicity. Confocal laser scanning microscopic observation also demonstrates the fluorescence imaging property of the prepared complex upon consumption by MCF‐7 cells. Both in vivo fluorescence imaging and MRI further confirm that the complex micelle with dual micellar structure may be a suitable liver‐specific contrast agent for clinical diagnosis.
Heterolytic (2 e) vs Homolytic (1 e) Oxidation Reactivity: N−H versus C−H Switch in the Oxidation of Lactams by Dioxirans
Authors: Annese Cosimo , D'Accolti Lucia , Fusco Caterina , Licini Giulia , Zonta Cristiano
Published: October 2016

Dioxiranes are powerful oxidants that can act via two different mechanisms: 1) homolytic (H abstraction and oxygen rebound) and 2) heterolytic (electrophilic oxidation). So far, it has been reported that the nature of the substrate dictates the reaction mode independently from the dioxirane employed. Herein, we report an unprecedented case in which the nature of the dioxirane rules the oxidation chemoselectivity. In particular, a switch from C−H to N−H oxidation is observed in the oxidation of lactams moving from dimethyl dioxirane (DDO) to methyl(trifluoromethyl)dioxirane (TFDO). A physical organic chemistry study, which combines the oxidation with two other dioxiranes methyl(fluoromethyl)dioxirane, MFDO, and methyl(difluoromethyl)dioxirane, DFDO, with computational studies, points to a diverse ability of the dioxiranes to either stabilize the homo or the heterolytic pathway.
Organocatalytic Asymmetric Benzylation and Aldol‐Hemiacetalization of α,β‐Unsaturated Trifluoromethyl Ketones: Efficient Enantioselective Construction of 3,4‐Dihydroisocoumarins
Authors: Duan Jindian , Cheng Yuyu , Cheng Jing , Li Rou , Li Pengfei
Published: October 2016

A new method has been developed for the organocatalytic enantioselective benzylation and aldol‐hemiacetalization of α,β‐unsaturated trifluoromethyl ketones with toluene derivatives in the presence of a tertiary amine‐thiourea catalyst. This method represents a facile and efficient strategy for the asymmetric synthesis of optically active 3,4‐dihydroisocoumarins bearing a trifluoromethylated tetrasubstituted carbon stereocenter with high enantioselectivity. Notably, this strategy was used to synthesize several chiral trifluoromethylated analogues of typharin with high efficiency.
Tris(imidazolin‐2‐ylidenamino)phosphine: A Crystalline Phosphorus(III) Superbase That Splits Carbon Dioxide
Authors: Mehlmann Paul , Mück‐Lichtenfeld Christian , Tan Tristan T. Y. , Dielmann Fabian
Published: October 2016

We report the synthesis and remarkable properties of the phosphine P(NIiPr)3 (NIiPr=1,3‐diisopropyl‐4,5‐dimethylimidazolin‐2‐ylidenamino), a crystalline solid accessible through a short and scalable route. Evaluation of the electron‐donor properties reveals a Tolman electronic parameter (TEP) value of 2029.7 cm−1 for the new phosphine that is significantly lower than those of all known phosphines or even N‐heterocyclic carbenes. Moreover, P(NIiPr)3 is more basic [pKBH+(MeCN)=38.8] than Verkade's proazaphosphatranes, thus being the strongest reported nonionic phosphorus(III) superbase. The coordination chemistry of the new phosphine towards different metal centers has been explored, and due to its unique electron‐releasing character, the phosphine is capable of capturing and cleaving the CO2 molecule.
ChemInform Abstract: Coupled Electronic and Magnetic Phase Transition in the Infinite‐Layer Phase LaSrNiRuO4.
Authors: Patino Midori Amano , Zeng Dihao , Bower Ryan , McGrady John E. , Hayward Michael A.
Published: October 2016

LaSrNiRuO4 is obtained by topochemical reduction of LaSrNiRuO6 with CaH2 at 360 °C.
ChemInform Abstract: Synthesis and Structure Determination of the Novel Aluminophosphate TL‐1: A New Layered Compound with Corner‐Sharing AlX6 Chains.
Authors: Pastero Linda , Arletti Rossella , Camara Fernando , Gigli Lara , Cagnoni Monica
Published: October 2016

The new compound (HMor)4[AlPO4F(H2O)] (HMor: protonated morpholine) is prepared by hydrothermal reaction of an aq.
ChemInform Abstract: Accessing Alkali‐Free NASICON‐Type Compounds Through Mixed Oxoanion Sol—Gel Chemistry: Hydrogen Titanium Phosphate Sulfate, H1‐xTi2(PO4)3‐x (SO4)x (x = 0.5—1).
Authors: Mieritz Daniel , Davidowski Stephen K. , Seo Dong‐Kyun
Published: October 2016

The Ti4+:PO43‐ ratio (1.0—1.5) and the calcination temperature (400—750 °C) are systematically varied in the preparation of the title NASICON‐type compounds.
ChemInform Abstract: New Ternary Tantalum Borides Containing Boron Dumbbells: Experimental and Theoretical Studies of Ta2OsB2 and TaRuB.
Authors: Mbarki Mohammed , Touzani Rachid St. , Rehorn Christian W. G. , Gladisch Fabian C. , Fokwa Boniface P. T.
Published: October 2016

Ta2OsB2 (I) and TaRuB (II) are prepared by arc‐melting of stoichiometric amounts of the elements.
ChemInform Abstract: Cascade Photoredox/Iodide Catalysis: Access to Difluoro‐γ‐Lactams via Aminodifluoroalkylation of Alkenes.
Authors: Zhang Muliang , Li Weipeng , Duan Yingqian , Xu Pan , Zhang Songlin , Zhu Chengjian
Published: October 2016

The reaction has a broad substrate scope, thus tolerating diversely functionalized styrene derivatives as well as cyclic and acyclic internal alkenes and various N‐arylated bromodifluoroacetamides, but no N‐alkylated derivatives thereof.
ChemInform Abstract: Copper‐Catalyzed Diesterification of 1,3‐Diene for the Synthesis of Allylic Diester Compounds.
Authors: Qian Bo , Xiong Haigen , Zhu Nengbo , Ye Changqing , Jian Wujun , Bao Hongli
Published: October 2016

A Cu‐catalyzed addition of aroyloxy radicals to conjugated dienes is studied to provide a synthesis of structural diverse allylic diester derivatives.
ChemInform Abstract: Catalyst‐Free Singlet Oxygen‐Promoted Decarboxylative Amidation of α‐Keto Acids with Free Amines.
Authors: Xu Wen‐Tao , Huang Bei , Dai Jian‐Jun , Xu Jun , Xu Hua‐Jian
Published: October 2016

The mild reaction can be scaled up.
ChemInform Abstract: I2/TBHP Mediated C—N and C—H Bond Cleavage of Tertiary Amines Toward Selective Synthesis of Sulfonamides and β‐Arylsulfonyl Enamines: The Solvent Effect on Reaction.
Authors: Lai Junyi , Chang Liming , Yuan Gaoqing
Published: October 2016

Performing the reaction in H2O delivers sulfonamides whereas DMSO as the solvent provides β‐arylsulfonyl enamines.
ChemInform Abstract: A Cross‐Coupling Synthesis of Functionalized Biaryls Using Knochel‐Type Organozinc Reagents and a Pyridine Enhanced Palladium Catalyst.
Authors: Wang Min , Liu Fang , Zeng Meng‐Tian , Xu Wan , Liu Min , Dong Zhi‐Bing
Published: October 2016

The protocol enables smooth, rapid, and mild Negishi reactions to give the biaryls in excellent yields.
ChemInform Abstract: CuSO4·5H2O‐Catalyzed Aminobenzannulation of ortho‐Alkynylaromatic Ketones with Anilines Approach Towards 1‐Aminonaphthalenes.
Authors: Guo Biao , Hua Ruimao
Published: October 2016

Aromatic and aliphatic amines are suitable reactants in the title process.
ChemInform Abstract: 2,5‐Oxyarylation of Furans: Synthesis of Spiroacetals via Palladium‐Catalyzed Aerobic Oxidative Coupling of Boronic Acids with α‐Hydroxyalkylfurans.
Authors: Li Jiuyi , Peng Hui , Wang Furong , Wang Xiujun , Jiang Huanfeng , Yin Biaolin
Published: October 2016

The scalable protocol is used for a novel transformation of sustainable furans into 2,5‐oxarylated derivatives.
ChemInform Abstract: Simple Alumina‐Mediated Synthesis of 2‐(2‐Hydroxypropan‐2‐yl)benzofuran‐3(2H)‐ones.
Authors: Fang Lizhen , Han Lili , Liu Saisai , Li Huanhuan
Published: October 2016

A novel protocol for the cross‐aldol condensation of acetone (II) and other carbonyl compounds (IV) with benzofuranones is developed using excess basic alumina as the promotor.
ChemInform Abstract: An Acyl‐Claisen/Paal‐Knorr Approach to Fully Substituted Pyrroles.
Authors: Dittrich Nora , Jung Eun‐Kyung , Davidson Samuel J. , Barker David
Published: October 2016

A wide variety of syn‐substituted 1,4‐diketones is synthesized using the acyl‐Claisen rearrangement.
ChemInform Abstract: Accessing Benzimidazoles via a Ring Distortion Strategy: An Oxone Mediated Tandem Reaction of 2‐Aminobenzylamines.
Authors: Hati Santanu , Kumar Dutta Pratip , Dutta Sanjay , Munshi Parthapratim , Sen Subhabrata
Published: October 2016

The efficient title reaction of 2‐aminobenzylamines with aryl, hetaryl, and alkyl aldehydes is described.
ChemInform Abstract: Controlling Asymmetric Remote and Cascade 1,3‐Dipolar Cycloaddition Reactions by Organocatalysis.
Authors: Poulsen Pernille H. , Vergura Stefania , Monleon Alicia , Joergensen Danny Kaare Bech , Joergensen Karl Anker
Published: October 2016

A regio‐ and stereoselective 1,3‐dipolar cycloaddition of 2,4‐dienals with nitrones is described to give the remote cycloadducts (III) in the presence of a diarylprolinolsilyl ether as catalyst.
ChemInform Abstract: Conformational Control of Chiral Amido‐Thiourea Catalysts Enables Improved Activity and Enantioselectivity.
Authors: Lehnherr Dan , Ford David D. , Bendelsmith Andrew J. , Kennedy C. Rose , Jacobsen Eric N.
Published: October 2016

The theoretical insights gained are experimentally examined performing an enantioselective oxocarbenium alkylation of α‐chloroisochroman with silyl enolates.
ChemInform Abstract: Base Free Regioselective Synthesis of α‐Triazolylazine Derivatives.
Authors: Harisha Mysore Bhyrappa , Nagaraj Muthupandi , Muthusubramanian Shanmugam , Bhuvanesh Nattamai
Published: October 2016

A facile regioselective α‐heteroarylation/deoxygenation reaction allows the synthesis of α‐triazolylazines from azine N‐oxides and N‐tosyltriazoles.
ChemInform Abstract: Organocatalytic Stereoselective Addition of Aldehydes to Acylquinolinium Ions.
Authors: Mengozzi Luca , Gualandi Andrea , Cozzi Pier Giorgio
Published: October 2016

A direct and simple activation of quinolines, without isolating unstable intermediates, or using isolated N,O‐acetals in the presence of Lewis or Broensted acids, is described.
ChemInform Abstract: A Multicomponent Access to 1,3‐Thiazine‐6‐phenylimino‐5‐carboxylates.
Authors: Trinh Trieu N. , McCluskey Adam
Published: October 2016

This facile method exhibits limited functional group tolerance providing the target products in low to moderate yields.
ChemInform Abstract: Ruthenium‐Catalyzed Dehydrogenative C—H Borylation of Arenes with Pinacolborane.
Authors: Murata Miki , Ueda Yosuke , Hyogo Mayu , Kohari Yoshihito , Namikoshi Takeshi , Watanabe Shinji
Published: October 2016

A ruthenium complex is shown to be efficient for the aromatic C—H borylation with pinacolborane.
ChemInform Abstract: Copper‐Catalyzed 8‐Aminoquinoline‐Directed Selenylation of Arene and Heteroarene C—H Bonds.
Authors: Mandal Anup , Sahoo Harekrishna , Baidya Mahiuddin
Published: October 2016

The scalable reaction between various aryl amides and diaryl diselenides provides diversely functionalized ortho‐diselenated products in high yields.
ChemInform Abstract: Palladium‐Catalyzed Direct C—H Arylation of Ferrocenecarboxamides with Aryl Halides.
Authors: Qiao Huijie , Sun Suyan , Yang Fan , Zhu Yu , Zhu Weiguo , Wu Yusheng , Wu Yangjie
Published: October 2016

A convenient protocol is developed for the ortho C—H arylation of substrates having a quinolin‐8‐ylamino directing group with aryl bromides.
ChemInform Abstract: Two New Nimbolinin‐Type Limonoids from the Fruits of Melia toosendan.
Authors: Zhang Qiong , Zhang Yong‐Gang , Li Qing‐Shan , Min Zhi‐Da
Published: October 2016

isolation, structure determination and cytotoxic activity of the two new limonoids (I), 12‐ethoxynimbolinius E and F, and seven known analogues
ChemInform Abstract: 2‐Trifluoromethylthiolation of Glycals.
Authors: Yu Yang , Xiong De‐Cai , Ye Xin‐Shan
Published: October 2016

Application of the title reaction to the 2‐trifluoromethylthiolation of lactals and deprotection of the products is demonstrated.
ChemInform Abstract: Iriomoteolides‐10a and 12a, Cytotoxic Macrolides from Marine Dinoflagellate Amphidinium Species.
Authors: Akakabe Mai , Kumagai Keiko , Tsuda Masayuki , Konishi Yuko , Tominaga Akira , Kaneno Daisuke , Fukushi Eri , Kawabata Jun , Masuda Atsunori , Tsuda Masashi
Published: October 2016

The cytotoxicity of the newly isolated compounds is examined.
ChemInform Abstract: Eu2+‐Activated Phase‐Pure Oxonitridosilicate Phosphor in a Ba—Si—O—N System via Facile Silicate‐Assisted Routes Designed by First‐Principles Thermodynamic Simulation.
Authors: Yun Young Jun , Kim Jin Kyu , Ju Ji Young , Choi Seul Ki , Park Woon Ik , Jung Ha‐kyun , Kim Yongseon , Choi Sungho
Published: October 2016

Phase‐pure, green‐emitting Ba3Si6O12N2:Eu2+ phosphor is obtained by firing (Ba1‐xEux)Si2O5 silicates in alumina crucibles with overcoated graphite powder under a flow of nitrogen containing 5% of H2 (1300 °C, <10 h).
ChemInform Abstract: Recent Progress of Silicon Composites as Anode Materials for Secondary Batteries
Authors: Wang Jingjing , Xu Tingting , Huang Xiao , Li Huan , Ma Tingli
Published: October 2016

Review: 117 refs.
ChemInform Abstract: Pt(II) and Pd(II) Interactions with Nucleosides‐Binding Sites‐New Compounds
Authors: Hadjiliadis Nick
Published: October 2016

Review: 49 refs.
ChemInform Abstract: From Phosphine‐Promoted to Phosphine‐Catalyzed Reactions by in situ Phosphine Oxide Reduction
Authors: Voituriez Arnaud , Saleh Nidal
Published: October 2016

Review: 46 refs + subrefs.
ChemInform Abstract: Ruthenium‐Catalyzed Metathesis of Conjugated Polyenes
Authors: Balla Aron , Al‐Hashimi Mohammed , Hlil Antisar , Bazzi Hassan S. , Tuba Robert
Published: October 2016

Review: [71 refs.
ChemInform Abstract: Recent Advances in Photoinduced Trifluoromethylation and Difluoroalkylation
Authors: Pan Xiaolin , Xia Hongguang , Wu Jie
Published: October 2016

Review: [74 refs.
ChemInform Abstract: Intramolecular Baylis‐Hillman Reaction: Synthesis of Heterocyclic Molecules
Authors: Basavaiah Deevi , Reddy Guddeti Chandrashekar
Published: October 2016

Review: 69 refs.
ChemInform Abstract: Helical Phosphorus Derivatives: Synthesis and Applications
Authors: Virieux David , Sevrain Nicolas , Ayad Tahar , Pirat Jean‐Luc
Published: October 2016

Review: 81 refs.
ChemInform Abstract: Glycomics: New Challenges and Opportunities in Regenerative Medicine
Authors: Russo Laura , Cipolla Laura
Published: October 2016

Review: [47 refs.
ChemInform Abstract: Engineering Multimetallic Nanocrystals for Highly Efficient Oxygen Reduction Catalysts
Authors: Wang Wei , Lei Bo , Guo Shaojun
Published: October 2016

Review: 88 refs.
ChemInform Abstract: Biological Synthesis of Nanosized Sulfide Semiconductors: Current Status and Future Prospects
Authors: Pinto da Costa Joao , Girao Ana Violeta , Trindade Tito , Costa Maria Clara , Duarte Armando , Rocha‐Santos Teresa
Published: October 2016

Review: 218 refs.
Morphology of visual sector thalamic reticular neurons in the macaque monkey suggests retinotopically specialized, parallel stream‐mixed input to the lateral geniculate nucleus
Authors: Bragg Elise M. , Fairless Elizabeth A. , Liu Shiyuan , Briggs Farran
Published: October 2016

The thalamic reticular nucleus (TRN) is a unique brain structure at the interface between the thalamus and the cortex. Because the TRN receives bottom‐up sensory input and top‐down cortical input, it could serve as an integration hub for sensory and cognitive signals. Functional evidence supports broad roles for the TRN in arousal, attention, and sensory selection. How specific circuits connecting the TRN with sensory thalamic structures implement these functions is not known. The structural organization and function of the TRN is particularly interesting in the context of highly organized sensory systems, such as the primate visual system, where neurons in the retina and dorsal lateral geniculate nucleus of the thalamus (dLGN) are morphologically and physiologically distinct and also specialized for processing particular features of the visual environment. To gain insight into the functional relationship between the visual sector of the TRN and the dLGN, we reconstructed a large number of TRN neurons that were retrogradely labeled following injections of rabies virus expressing enhanced green fluorescent protein (EGFP) into the dLGN. An independent cluster analysis, based on 10 morphological metrics measured for each reconstructed neuron, revealed three clusters of TRN neurons that differed in cell body shape and size, dendritic arborization patterns, and medial‐lateral position within the TRN. TRN dendritic and axonal morphologies are inconsistent with visual stream‐specific projections to the dLGN. Instead, TRN neuronal organization could facilitate transmission of global arousal and/or cognitive signals to the dLGN with retinotopic precision that preserves specialized processing of foveal versus peripheral visual information. J. Comp. Neurol. 525:1273–1290, 2017. © 2016 Wiley Periodicals, Inc.
Color of absence and presence: Reconsidering black in architecture
Authors: Yılmaz Ahenk
Published: October 2016

Abstract: This article explores the effects of using black on spatial experience by means of phenomenological analysis of its architectural examples with a special focus on Serpentine Gallery Pavilion designed by Peter Zumthor. Contrary to the growing interest in the color in contemporary architecture, black rarely found a place in architectural history and in studies on color design. Whereas, the distinct achromatic qualities of the color that appear highly self‐contradictory swinging back and forth from absence to presence cover a wide range of potentials to be used in architectural design. Through insights delved into the spatial experience constructed around these qualities, this paper attempts to analyze how black is used as a design element in built environments. This analysis revolves around Zumthor s pavilion, which stood as a uniform black box on the expanse of green grass of London Kensington Gardens for more than three months in 2011. Encompassing various oppositions, the box built to surround a hortus conclusus, an enclosed garden inside, provided its visitors with a unique spatial experience depending predominantly on the combination of its form, tectonics and the qualities of its color, black. The phenomenological analysis of these qualities manifests that the architect utilized the contradictory characteristics of the color intentionally in order to create a complex and manifold spatial experience for visitors in and outside the box. In an interplay of absence and presence, momentary crystallizations of the vision of black provide architects with uncharted opportunities for creative use of color in the design of built environments. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 378–387, 2017
Inverted Micelle‐in‐Micelle Configuration in Cationic/Carbohydrate Surfactant Mixtures
Authors: Das Saikat , Xu Wenjin , Lehmler Hans‐Joachim , Miller Anne‐Frances , Knutson Barbara L. , Rankin Stephen E.
Published: October 2016

Nuclear magnetic resonance is applied to investigate the relative positions and interactions between cationic and non‐ionic carbohydrate‐based surfactants in mixed micelles with D2O as the solvent. This is accomplished by using relaxation measurements [spin‐lattice (T1) and spin‐spin (T2) analysis] and nuclear Overhauser effect spectroscopy (NOESY). This study focuses on the interactions of n‐octyl β‐d‐glucopyranoside (C8G1) and β‐d‐xylopyranoside (C8X1) with the cationic surfactant hexadecyltrimethylammonium bromide (C16TAB). Whereas the interactions between carbohydrate and cationic surfactants are thermodynamically favorable, the NOESY results suggest that both of the sugar head groups are located preferentially at the interior core of the mixed micelles, so that they are not directly exposed to the bulk solution. The more hydrophilic sugar headgroups of C8G1 have more mobility than sugar heads of C8X1 owing to increased hydration. Herein, an inverted carbohydrate configuration in mixed micelles is proposed for the first time and supported by fluorescence spectroscopy experiments. This inverted carbohydrate headgroup configuration would limit the use of these mixed surfactants when access to the carbohydrate headgroup is important, but may present new opportunities where the carbohydrate‐rich core of the micelles can be exploited.
Creating an Efficient Methanol‐Stable Biocatalyst by Protein and Immobilization Engineering Steps towards Efficient Biosynthesis of Biodiesel
Authors: Gihaz Shalev , Weiser Diána , Dror Adi , Sátorhelyi Péter , Jerabek‐Willemsen Moran , Poppe László , Fishman Ayelet
Published: October 2016

Two ternary sol–gel matrices, an octyltriethoxysilane‐based aliphatic matrix and a phenyltriethoxysilane (PTEOS)‐based aromatic matrix, were used to immobilize a methanol‐stable variant of lipase from Geobacillus stearothermophilus T6 for the synthesis of biodiesel from waste oil. Superior thermal stability of the mutant versus the wildtype in methanol was confirmed by intrinsic protein fluorescence measurements. The influence of skim milk and soluble E. coli lysate proteins as bulking and stabilizing agents in conjunction with sol–gel entrapment were investigated. E. coli lysate proteins were better stabilizing agents of the purified lipase mutant than skim milk, as evidenced by reverse engineering of the aromatic‐based system. This was also shown for commercial Candida antarctica lipase B (CaLB) and Thermomyces lanuginosus lipase (TLL). Uniform, dense, and nonaggregated particles imaged by scanning electron microscopy and a small particle size of 13 μm pertaining to the system comprising PTEOS and E. coli lysate proteins correlated well with high esterification activity. Combining protein and immobilization engineering resulted in a durable biocatalyst with efficient recycling ability and high biodiesel conversion rates.
Migratory herds of wildebeests and zebras indirectly affect calf survival of giraffes
Authors: Lee Derek E. , Kissui Bernard M. , Kiwango Yustina A. , Bond Monica L.
Published: October 2016

In long‐distance migratory systems, local fluctuations in the predator–prey ratio can exhibit extreme variability within a single year depending upon the seasonal location of migratory species. Such systems offer an opportunity to empirically investigate cyclic population density effects on short‐term food web interactions by taking advantage of the large seasonal shifts in migratory prey biomass.

We utilized a large‐mammal predator–prey savanna food web to evaluate support for hypotheses relating to the indirect effects of “apparent competition” and “apparent mutualism” from migratory ungulate herds on survival of resident megaherbivore calves, mediated by their shared predator. African lions (Panthera leo) are generalist predators whose primary, preferred prey are wildebeests (Connochaetes taurinus) and zebras (Equus quagga), while lion predation on secondary prey such as giraffes (Giraffa camelopardalis) may change according to the relative abundance of the primary prey species.

We used demographic data from five subpopulations of giraffes in the Tarangire Ecosystem of Tanzania, East Africa, to test hypotheses relating to direct predation and indirect effects of large migratory herds on calf survival of a resident megaherbivore. We examined neonatal survival via apparent reproduction of 860 adult females, and calf survival of 449 giraffe calves, during three precipitation seasons over 3 years, seeking evidence of some effect on neonate and calf survival as a consequence of the movements of large herds of migratory ungulates.

We found that local lion predation pressure (lion density divided by primary prey density) was significantly negatively correlated with giraffe neonatal and calf survival probabilities. This supports the apparent mutualism hypothesis that the presence of migratory ungulates reduces lion predation on giraffe calves.

Natural predation had a significant effect on giraffe calf and neonate survival, and could significantly affect giraffe population dynamics. If wildebeest and zebra populations in this ecosystem continue to decline as a result of increasingly disrupted migrations and poaching, then giraffe calves will face increased predation pressure as the predator–prey ratio increases. Our results suggest that the widespread population declines observed in many migratory systems are likely to trigger demographic impacts in other species due to indirect effects like those shown here.
Aboveground and belowground mammalian herbivores regulate the demography of deciduous woody species in conifer forests
Authors: Endress Bryan A. , Naylor Bridgett J. , Pekin Burak K. , Wisdom Michael J.
Published: October 2016

Mammalian herbivory can have profound impacts on plant population and community dynamics. However, our understanding of specific herbivore effects remains limited, even in regions with high densities of domestic and wild herbivores, such as the semiarid conifer forests of western North America. We conducted a seven‐year manipulative experiment to evaluate the effects of herbivory by two common ungulates, Cervus elaphus (Rocky Mountain elk) and cattle Bos taurus (domestic cattle) on growth and survival of two woody deciduous species, Populus trichocarpa (cottonwood) and Salix scouleriana (Scouler's willow) in postfire early‐successional forest stands. Additionally, we monitored belowground herbivory by Thomomys talpoides (pocket gopher) and explored effects of both aboveground and belowground herbivory on plant vital rates. Three, approximately 7 ha exclosures were constructed, and each was divided into 1‐ha plots. Seven herbivory treatments were then randomly assigned to the plots: three levels of herbivory (low, moderate, and high) for both cattle and elk, and one complete ungulate exclusion treatment. Treatments were implemented for seven years. Results showed that cattle and elk substantially reduced height and growth of both cottonwood and willow. Elk had a larger effect on growth and subsequent plant height than cattle, especially for cottonwood, and elk effects occurred even at low herbivore densities. Pocket gophers had a strong effect on survival of both plant species while herbivory by ungulates did not. However, we documented significant interaction effects of aboveground and belowground herbivory on survival. Our study is one of the first to evaluate top‐down regulation by multiple herbivore species at varying densities. Results suggest that traditional exclosure studies that treat herbivory as a binary factor (either present or absent) may not be sufficient to characterize top‐down regulation on plant demography. Rather, the strength of top‐down regulation varies depending on a number of factors including herbivore species, herbivore density, interactions among multiple herbivore species, and varying tolerance levels of different plant species to herbivory.
Negative impacts of invasive plants on conservation of sensitive desert wildlife
Authors: Drake K. Kristina , Bowen Lizabeth , Nussear Kenneth E. , Esque Todd C. , Berger Andrew J. , Custer Nathan A. , Waters Shannon C. , Johnson Jay D. , Miles A. Keith , Lewison Rebecca L.
Published: October 2016

Habitat disturbance from development, resource extraction, off‐road vehicle use, and energy development ranks highly among threats to desert systems worldwide. In the Mojave Desert, United States, these disturbances have promoted the establishment of nonnative plants, so that native grasses and forbs are now intermixed with, or have been replaced by invasive, nonnative Mediterranean grasses. This shift in plant composition has altered food availability for Mojave Desert tortoises (Gopherus agassizii), a federally listed species. We hypothesized that this change in forage would negatively influence the physiological ecology, immune competence, and health of neonatal and yearling tortoises. To test this, we monitored the effects of diet on growth, body condition, immunological responses (measured by gene transcription), and survival for 100 captive Mojave tortoises. Tortoises were assigned to one of five diets: native forbs, native grass, invasive grass, and native forbs combined with either the native or invasive grass. Tortoises eating native forbs had better body condition and immune functions, grew more, and had higher survival rates (>95%) than tortoises consuming any other diet. At the end of the experiment, 32% of individuals fed only native grass and 37% fed only invasive grass were found dead or removed from the experiment due to poor body conditions. In contrast, all tortoises fed either the native forb or combined native forb and native grass diets survived and were in good condition. Health and body condition quickly declined for tortoises fed only the native grass (Festuca octoflora) or invasive grass (Bromus rubens) with notable loss of fat and muscle mass and increased muscular atrophy. Bromus rubens seeds were found embedded in the oral mucosa and tongue in most individuals eating that diet, which led to mucosal inflammation. Genes indicative of physiological, immune, and metabolic functions were transcribed at lower levels for individuals fed B. rubens, indicating potential greater susceptibility to disease or other health‐related problems. This study highlights the negative indirect effects of invasive grasses, such as red brome, in desert ecosystems, and provides definitive evidence of a larger negative consequence to health, survival, and ultimately population recruitment for Mojave Desert tortoises than previously understood.
Elastic Capacitor Electrode Based on Carbon‐embedded Polymer Matrix
Authors: Thibodeau Jake , Ignaszak Anna
Published: October 2016

AC impedance and voltammetry investigations revealed strong effect of the electrode composition on its machanical and electrical properties and led to its optimization in a CNT‐PVA‐PEG‐SiO2‐KClaqsystem with good elasticity and excellent electrochemical stability. The uniform distribution of SiO2and carbon in the polymer fraction was confirmed by SEM imaging. This morphology facilitates retaining water and flexibility of films. An improvement of mass transport in the capacitor electrode as compared to a pure electrolyte was justified based on analysis of the diffusion resistance. The specific capacitance of the electrode and symmetrical capacitor cell is in the mF range and is suitable power system for microelectronic components.
d‐electron count, ion‐pairing and diagonal twist angles in metallo‐bis(dithiolene) complexes
Authors: Kirkpatrick Charles C. , Truong John N. , Kowert Bruce A.
Published: October 2016

Electronic structure calculations for late transition metals coordinated by two dithiolene ligands are found to be consistent with existing structures and also predict the geometries of Ni(I) species for which no solid state structures have been reported. Of particular interest are the compounds [M(mnt)2]n− (M = Ni, Pd, and Pt with n = 1, 2, 3; M = Cu with n = 2). Calculations have been performed with and without ion‐paring with M(diglyme)+ (M = Li, Na, K) and R4N+ (R = Me, Bu). The diagonal twist angle between two NiS2 planes is found to depend on (i) the metal's d‐electron count, spanning from 0° (planar d7 and d8), to 42° (d9), to 90° (pseudo‐tetrahedral d10), and (ii) the identity of the ion‐paired cations. Calculated ion‐pairing energies are functions of the cation size and charge‐density, being larger for alkali‐metal coordinated diglyme and smaller for tetra‐alkyl ammonium cations. © 2016 Wiley Periodicals, Inc.
Self‐Compassion Online: A Pilot Study of an Internet‐Based Self‐Compassion Cultivation Program for Psychology Trainees
Authors: Finlay‐Jones Amy , Kane Robert , Rees Clare
Published: October 2016

Objective

The current study sought to conduct a preliminary investigation of the effectiveness and feasibility of a novel, self‐guided online self‐compassion training for reducing psychological distress and increasing self‐compassion and happiness among psychology trainees.

Method

A 6‐week online self‐compassion cultivation program was developed and delivered to Australian psychology trainees (n = 37), and a pre‐experimental repeated‐measures design was used to collect change data on self‐compassion, happiness, perceived stress, emotion regulation difficulties as well as symptoms of depression, anxiety, and stress.

Results

Participants reported significant increases in self‐compassion and happiness and significant decreases in depression, stress, and emotion regulation difficulties between pretest and posttest, with the majority of changes maintained at 3‐month follow up.

Conclusion

 This study provides preliminary evidence supporting the effectiveness and acceptability of online self‐compassion training as a positive, integrated, and meaningful way of reducing distress and promoting self‐compassion and happiness among trainee psychologists.
Quantification of breast stiffness using MR elastography at 3 Tesla with a soft sternal driver: A reproducibility study
Authors: Hawley Jeffrey R. , Kalra Prateek , Mo Xiaokui , Raterman Brian , Yee Lisa D. , Kolipaka Arunark
Published: October 2016

Purpose

Previous studies of breast MR elastography (MRE) evaluated the technique at magnetic field strengths of 1.5 Tesla (T) with the breast in contact with the driver. The aim of this study is to evaluate breast stiffness measurements and their reproducibility using a soft sternal driver at 3T and compare the results with qualitative measures of breast density.

Materials and Methods

Twenty‐two healthy volunteers each underwent two separate breast MRE scans in a 3T MRI. MRE vibrations were introduced into the breasts at 60 Hz using a soft sternal driver and axial slices were collected using a gradient echo MRE sequence. Mean stiffness measurements were calculated for each volunteer as well as a measure of reproducibility using concordance correlation between scans. Mean stiffness values for each volunteer were assessed and related to amounts of fibroglandular tissue (i.e., breast lobules, ducts, and fibrous connective tissue).

Results

The stiffness values were reproducible with a significant P‐value < 0.0001 between two scans with concordance correlation of 0.87 and 0.91 for center slice and grouping all slices, respectively. Volunteers with dense breasts (i.e., higher grades of fibroglandular tissue) had mean stiffness values of 0.96 kPa (center slice) and 0.92 kPa (all slices) while those without dense breasts had mean stiffness values of 0.85 kPa (center slice) and 0.83 kPa (all slices) (P ≤ 0.05).

Conclusion

Breast MRE is a reproducible technique at 3T using a soft sternal driver. Dense breasts had significantly higher stiffness measurements compared with nondense breasts.

Level of Evidence: 2

J. MAGN. RESON. IMAGING 2017;45:1379–1384
Chronology and processes of late Quaternary hillslope sedimentation in the eastern South Island, New Zealand
Authors: Borella Josh , Quigley Mark , Sohbati Reza , Almond Peter , Gravley Darren M. , Murray Andrew
Published: October 2016

Optical and radiocarbon dating of loessic hillslope sediments in New Zealand's South Island is used to constrain the timing of prehistoric rockfalls and associated seismic events, and quantify spatial and temporal patterns of hillslope sedimentation including responses to seismic and anthropogenic forcing. Trenches adjacent to prehistoric boulders enable stratigraphic analysis of loess and loess‐colluvium pre‐ and post‐dating boulder emplacement, respectively. Luminescence ages from loessic sediments constrain the timing of boulder emplacement to between ∼3.0 and ∼12.5 ka, well before the arrival of Polynesians (ca. AD 1280) and Europeans (ca. AD 1800) in New Zealand, and suggest loess accumulation was continuing at the study site until 12–13 ka. Large (>5 m3) prehistoric rockfall boulders preserve an important record of Holocene hillslope sedimentation by creating local traps (i.e. accommodation space) for sediment aggradation (i.e. colluvial wedges) and upbuilding soil formation. Sediment accumulation rates increased considerably (>∼10 factor increase) following human arrival and associated anthropogenic burning of hillslope vegetation. Our study presents new numerical ages to place the evolution of loess‐mantled hillslopes in New Zealand's South Island into a longer temporal framework and highlights the roles of earthquakes and humans on hillslope surface process.
Brief sea‐level fall event and centennial to millennial sea‐level variations during Marine Isotope Stage 19 in Osaka Bay, Japan
Authors: Maegakiuchi Kenta , Hyodo Masayuki , Kitaba Ikuko , Hirose Kotaro , Katoh Shigehiro , Sato Hiroshi
Published: October 2016

Detailed sea‐level variation was investigated for Marine Isotope Stage (MIS) 19, based on diatom and grain size analyses of a marine sequence in a core of the Osaka Group. Diatom sea‐level proxies represent precession‐related signals correlated with highstands MIS 19.3 and 19.1, and lowstand MIS 19.2. Astronomical tuning shows the marine sequence has a uniform accumulation rate of about 60 cm ka−1. A rapid sea‐level fall event was found in the earliest MIS 19, demonstrated by several independent sea‐level proxies of diatom and grain size. This event began with a rapid sea‐level drop, followed by a gradual recovery, at about 783–782 ka. A maximum abundance of pelagic diatom taxa at a core depth of 402.20 m evidently shows the highest sea‐level peak in MIS 19, supported by many other proxies. Based on the diatom data, sea‐level change across MIS 19.1 is characterized by centennial to millennial fluctuations. The sea‐level fall event began just after the onset of a cooling event previously reported from the same core. Observations of a comparable sea‐level fall signal in many deep‐sea core records suggest the event is global.
Marker‐assisted introgression of broad‐spectrum blast resistance genes into the cultivated MR219 rice variety
Authors: Miah Gous , Rafii Mohd Y , Ismail Mohd R , Puteh Adam B , Rahim Harun A , Latif Mohammad A
Published: October 2016

BACKGROUND

The rice cultivar MR219 is famous for its better yield and long and fine grain quality; however, it is susceptible to blast disease. The main objective of this study was to introgress blast resistance genes into MR219 through marker‐assisted selection (MAS). The rice cultivar MR219 was used as the recurrent parent, and Pongsu Seribu 1 was used as the donor.

RESULTS

Marker‐assisted foreground selection was performed using RM6836 and RM8225 to identify plants possessing blast resistance genes. Seventy microsatellite markers were used to estimate recurrent parent genome (RPG) recovery. Our analysis led to the development of 13 improved blast resistant lines with Piz, Pi2 and Pi9 broad‐spectrum blast resistance genes and an MR219 genetic background. The RPG recovery of the selected improved lines was up to 97.70% with an average value of 95.98%. Selected improved lines showed a resistance response against the most virulent blast pathogen pathotype, P7.2. The selected improved lines did not express any negative effect on agronomic traits in comparison with MR219.

CONCLUSION

The research findings of this study will be a conducive approach for the application of different molecular techniques that may result in accelerating the development of new disease‐resistant rice varieties, which in turn will match rising demand and food security worldwide. © 2016 Society of Chemical Industry
Rapid discovery of absorbed constituents and metabolites in rat plasma after the oral administration of Zi Shen Wan using high‐throughput UHPLC–MS with a multivariate analysis approach
Authors: Li Xian‐Na , Zhang Aihua , Sun Hui , Song Yanhua , Zou Di , Wang Xijun
Published: October 2016

Zi Shen Wan is a typical formula consisting of three herbs, Phellodendri Amurensis Cortex, Rhizoma Anemarrhenae, and Cortex Cinnamomi, and has been widely used for treating prostatitis and infection diseases. However, it lacks in‐depth research of the constituents of Zi Shen Wan in vivo and in vitro. In this work, ultra high performance liquid chromatography coupled with quadrupole‐time‐of‐flight mass spectrometry and MassLynx software was established to characterize the chemical compositions of Zi Shen Wan in vivo and in vitro. In total, 92 peaks were characterized in vitro and 33 peaks were characterized in vivo based on mass spectrometry and tandem mass spectrometry data. Among the 33 compounds characterized in rat plasma, 22 prototype components absorbed in rat serum and 11 metabolites were identified in vivo. This work was fully reports the chemical constituents of traditional Chinese formula of Zi Shen Wan, it demonstrated that ultra high performance liquid chromatography combined with quadrupole time‐of‐flight mass spectrometry coupled to MassLynx software and multivariate data processing approach could be successfully applied for rapid screening and comprehensive analysis of chemical constituents in vitro and prototype components or metabolites in vivo of traditional Chinese medicine.
Public (Q)SAR Services, Integrated Modeling Environments, and Model Repositories on the Web: State of the Art and Perspectives for Future Development
Authors: Tetko Igor V. , Maran Uko , Tropsha Alexander
Published: October 2016

Thousands of (Quantitative) Structure‐Activity Relationships (Q)SAR models have been described in peer‐reviewed publications; however, this way of sharing seldom makes models available for the use by the research community outside of the developer's laboratory. Conversely, on‐line models allow broad dissemination and application representing the most effective way of sharing the scientific knowledge. Approaches for sharing and providing on‐line access to models range from web services created by individual users and laboratories to integrated modeling environments and model repositories. This emerging transition from the descriptive and informative, but “static”, and for the most part, non‐executable print format to interactive, transparent and functional delivery of “living” models is expected to have a transformative effect on modern experimental research in areas of scientific and regulatory use of (Q)SAR models.
The Australian Pelvic Floor Questionnaire is a valid measure of pelvic floor symptoms in patients following surgery for colorectal cancer
Authors: Lin Kuan‐Yin , Frawley Helena C. , Granger Catherine L. , Denehy Linda
Published: October 2016

Aims

This study evaluated the construct validity of the Australian Pelvic Floor Questionnaire against two alternative measures of the severity of bladder and bowel symptoms.

Methods

This was an exploratory analysis of data from two prospective studies. Patients who had undergone surgery for colorectal cancer were analysed. Bladder and bowel symptoms were measured using three validated questionnaires: the Australian Pelvic Floor Questionnaire, the International Consultation on Incontinence Questionnaire Short Form Questionnaire for urinary incontinence and the International Consultation on Incontinence Questionnaire‐Bowel Module post‐cancer treatment.

Results

The study sample consisted of 44 participants, including 25 men and 19 women. The Australian Pelvic Floor Questionnaire bladder and bowel domain scores demonstrated moderate positive correlations with the International Consultation on Incontinence Questionnaire Short Form Questionnaire for urinary incontinence (r = 0.74, P < 0.01) and the International Consultation on Incontinence Questionnaire‐Bowel Module (r = 0.69–0.78, P < 0.01). Similar results were obtained in each gender subgroup.

Conclusions

This study suggested that the Australian Pelvic Floor Questionnaire may be a valid measurement tool for use in colorectal cancer populations in clinical trials and practice. Future research using larger cohorts is warranted.