bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ternary Mixed‐Valence Organotin Copper Selenide Clusters
Authors: Rinn Niklas , Guggolz Lukas , Lange Jurek , Chatterjee Sangam , Block Theresa , Pöttgen Rainer , Dehnen Stefanie 
Published: February 2018

AbstractReactions of the organotin selenide chloride clusters [(R1SnIV)3Se4Cl] (A, R1=CMe2CH2C(O)Me) or [(R1SnIV)4Se6] (B) with [Cu(PPh3)3−xClx] yield cluster compounds with different inorganic, mixed‐valence core structures: [Cu4SnIISnIV6Se12], [Cu2SnII2SnIV4Se8Cl2], [Cu2SnIISnIV4Se8], [Cu2SnII2SnIV2Se4Cl4], and [Cu2SnIV2Se4]. Five of the compounds, namely [(CuPPh3)2{(R1SnIV)2Se4}] (1), [(CuPPh3)2SnII{(R2SnIV)2Se4}2] (2), [(CuPPh3)2(SnIICl)2{(RSnIV)2Se4}2] (3) [(CuPPh3)2(SnIICu2){(R1SnIV)2Se4}3] (4), and [Cu(CuPPh3)(SnIICu2){(R1SnIV)2Se4}3] (5) are structurally closely related. They are based on [(CuPPh3)2{(RSnIV)2Se4}n] aggregates comprising [(RSnIV)2Se4] and [CuPPh3] building units, which are linked by further metal atoms. A sixth compound, [(CuPPh3)2(SnIICl)2{(R1SnIVCl)Se2}2] (6), differs from the others by containing [(RSnIVCl)Se2] units instead, which affects the absorption properties. The compounds were analyzed by single‐crystal X‐ray diffraction, NMR and 119Sn Mössbauer spectroscopy, DFT calculations as well as optical absorption experiments.
Ethers as Oxygen Donor and Carbon Source in Non‐hydrolytic Sol–Gel: One‐Pot, Atom‐Economic Synthesis of Mesoporous TiO2–Carbon Nanocomposites
Authors: Escamilla‐Pérez Angel Manuel , Louvain Nicolas , Boury Bruno , Brun Nicolas , Mutin P. Hubert 
Published: February 2018

AbstractMesoporous TiO2–carbon nanocomposites were synthesized using an original non‐hydrolytic sol–gel (NHSG) route, based on the reaction of simple ethers (diisopropyl ether or tetrahydrofuran) with titanium tetrachloride. In this atom‐economic, solvent‐free process, the ether acts not only as an oxygen donor but also as the sole carbon source. Increasing the reaction temperature to 180 °C leads to the decomposition of the alkyl chloride by‐product and to the formation of hydrocarbon polymers, which are converted to carbon by pyrolysis under argon. The carbon–TiO2 nanocomposites and their TiO2 counterparts (obtained by calcination) were characterized by nitrogen physisorption, XRD, solid state 13C NMR and Raman spectroscopies, SEM, and TEM. The nanocomposites are mesoporous with surface areas of up to 75 m2 g−1 and pore sizes around 10 nm. They are composed of aggregated anatase nanocrystals coated by an amorphous carbon film. Playing on the nature of the ether and on the reaction temperature allows control over the carbon content in the nanocomposites. The nature of the ether also influences the size of the TiO2 crystallites and the morphology of the nanocomposite. To further characterize the carbon coating, the behavior of the carbon‐TiO2 nanocomposites and bare TiO2 samples toward lithium insertion–deinsertion was investigated in half‐cells. This simple NHSG approach should provide a general method for the synthesis of a wide range of carbon–metal oxide nanocomposites.
Sensitive and Selective Detection of Phosgene, Diphosgene, and Triphosgene by a 3,4‐Diaminonaphthalimide in Solutions and the Gas Phase
Authors: Wang Shao‐Lin , Zhong Lin , Song Qin‐Hua 
Published: February 2018

AbstractPhosgene and its substitutes, diphosgene and triphosgene, are highly toxic and widely used chemicals, so it is necessary to investigate their reactivity and develop facile, sensitive, and specific methods for detecting them. In this work, we have developed a new 1,8‐naphthalimide‐based fluorescent chemosensor, Phos‐2, which exhibits high sensitivity (detection limits: 0.2–0.7 nm), high selectivity to phosgene and its substitutes over nitric oxide (NO), various acyl chlorides, and nerve agent mimics in solutions. Based on investigation of the reaction kinetics of Phos‐2 with phosgene and its substitutes, a two‐step sensing mechanism was clarified. The second‐order rate constants (k2) of Phos‐2 reveal that the relative rate constants of phosgene, diphosgene, and triphosgene are 40:4:1. Moreover, a Phos‐2 test paper has been fabricated as a low‐cost, sensitive (≈5 ppm from observation by the naked eye or 0.1 ppm from a measurement), and efficient method for visual detection of a low concentration of phosgene in the gas phase.
Covalent Immobilization of (−)‐Riboflavin on Polymer Functionalized Silica Particles: Application in the Photocatalytic E→Z Isomerization of Polarized Alkenes
Authors: Metternich Jan B. , Sagebiel Sven , Lückener Anne , Lamping Sebastian , Ravoo Bart Jan , Gilmour Ryan 
Published: February 2018

AbstractThe covalent immobilization of the biomimetic, photo‐organocatalyst (−)‐riboflavin on silica micro‐ and nanoparticles via atom transfer radical polymerization (ATRP) is disclosed. Given the effectiveness of (−)‐riboflavin as a versatile, environmentally benign photocatalyst, an immobilization strategy based on acrylate‐linker modification of the catalyst core and controlled polymerization on initiator pre‐functionalized silica particles has been developed. Validation of this approach is demonstrated in the E→Z isomerization of a benchmark cinnamonitrile (Z/E up to 88:12) with 0.97 mol % catalyst loading. Characterization of the immobilized photocatalyst supports covalent embedding of the catalyst in the polymeric brushes on the silica particle surface.
The Interaction Modes of Haloimidazolium Salts in Solution
Authors: Schulz Nils , Sokkar Pandian , Engelage Elric , Schindler Severin , Erdelyi Mate , Sanchez‐Garcia Elsa , Huber Stefan M. 
Published: February 2018

AbstractInvited for the cover of this issue is the group of Elsa Sanchez‐Garcia at the Universität Duisburg‐Essen and Stefan M. Huber at the Ruhr‐University Bochum. The image depicts the crystal structure of an iodoimidazolium salt showing one of the possible interactions. Read the full text of the article at 10.1002/chem.201705032.
Supramolecular Recognition of Three Way Junction DNA by a Cationic Calix[3]carbazole
Authors: Yang Zhaozheng , Chen Yan , Li Gang , Tian Zhangmin , Zhao Liang , Wu Xi , Ma Qi , Liu Mingzhe , Yang Peng 
Published: February 2018

AbstractInvited for the cover of this issue is the group of Peng Yang at the Shenyang Pharmaceutical University. The image depicts how the calix[3]carbazole interacts with three way junctions DNA. Read the full text of the article at 10.1002/chem.201705564.
Arene‐Ligand‐Free Ruthenium(II/III) Manifold for meta‐C−H Alkylation: Remote Purine Diversification
Authors: Fumagalli Fernando , Warratz Svenja , Zhang Shou‐Kun , Rogge Torben , Zhu Cuiju , Stückl A. Claudia , Ackermann Lutz 
Published: February 2018

Abstractmeta‐Selective C−H alkylations of bioactive purine derivatives were accomplished by versatile ruthenium catalysis. Thus, the arene‐ligand‐free complex [Ru(OAc)2(PPh3)2] enabled remote C−H functionalizations with ample scope and excellent levels of chemo‐ and positional selectivities. Detailed experimental and computational mechanistic studies provided strong support for a facile C−H activation within a ruthenium(II/III) manifold.
Mutual inversion of flurbiprofen enantiomers in various rat and mouse strains
Authors: de Bruin Natasja , Ferreirós Nerea , Schmidt Mike , Hofmann Martine , Angioni Carlo , Geisslinger Gerd , Parnham Michael John 
Published: February 2018

AbstractFlurbiprofen (F) is a nonsteroidal anti‐inflammatory drug (NSAID) used therapeutically as the racemate of (R)‐enantiomer and (S)‐enantiomer. The inversion of RF to SF and vice versa was investigated in C57Bl/6 and SJL mice and Dark Agouti and Lewis rats. The enzyme α‐methylacyl‐CoA racemase (AMACR) is involved in the chiral inversion pathway that converts members of the 2‐arylpropionic acid NSAIDs from the R‐enantiomer to the S‐enantiomer. We studied C57Bl/6 mice deficient in AMACR postulating that they should show reduced inversion of RF to SF. In line with the data of others in mice, (R)‐inversion to (S)‐inversion was relatively high in both the C57Bl/6 and SJL mice (fraction inverted, FI = 37.7% and 24.7%, respectively). In contrast, in AMACR deficient mice, there was no measurable peak for SF after administration of RF. The results in both rat strains (Dark Agouti and Lewis rats, FI = 1.4% and 4.1%, respectively) confirm the low chiral inversion of the enantiomers of flurbiprofen in the rat, as observed by other authors in the Sprague‐Dawley strain (<5%). From the present results, we conclude that for the study of flurbiprofen enantiomers, the rat is more suitable than the mouse as a model for the human in which (R)‐inversion to (S)‐inversion is negligible.
A STUDY ON SPECTRAL MOMENTS OF GRAVITY FIELD WITH APPLICATION TO CRUSTAL STRUCTURE IMAGING OF TARIM BASIN
Authors: Wen‐Cai YANG , Yan‐Yun SUN , Zun‐Ze HOU , Chang‐Qing YU 
Published: February 2018

AbstractModern geophysical techniques provide great amount data of geophysical field that contain rich information about crustal structures, which can be extracted for geo‐mapping based on theory of mathematical physics. This paper shows that the high‐order spectral moments of regional gravity data include information of geometrical contour surface, which can be used for selection, positioning and classification of some types of geological structures. By using second‐order spectral moments of Bouguer gravity data, one can calculate their statistical unvaried quantities and the ridge‐like parameter, which characterizes the crustal deformation belts and can be used for mapping regional distribution of the deformation belts. The boundaries between areas of strong or weak ridge‐like parameters represent boundaries of different structural units. We can further compute the second‐order spectral moments of the statistical unvaried quantities to calculate the boundary parameter, which may be used for tracing and positioning the structural boundaries after some enhancement are added. This paper gives all the formula for computing the ridge and the boundary parameters, and testing results on crustal structural analysis in Tarim basin, Northwest China. As the results, deep High‐ and Low‐density belts within the Tarim basin are located precisely, providing important basic images for oil/gas exploration in the basin.
THE ADVANCEMENT OF LUNAR GRAVITY MODEL DUE TO THE DEVELOPMENT OF SPACE TRACKING TECHNIQUES
Authors: Fei LI , Wei‐Feng HAO , Jian‐Guo YAN , Xian‐Yuan SHAO , Mao YE , Chi XIAO 
Published: February 2018

AbstractBased on the three modes of lunar spacecraft tracking techniques: Earth‐based tracking mode, high‐low satellite‐to‐satellite tracking mode and low‐low satellite‐to‐satellite tracking mode, the development of lunar gravity models could be divided into 4 stages. First, we introduce the principle, technical characteristics of the different tracking modes, and the representative gravity models, and then make comments on these models’ precision. Further, through the comparison of gravity anomaly precision, characteristics and orbit determination precision from different stages’ lunar gravity field models, we conclude that: the advancement of space tracking techniques has significantly improved the precision of lunar gravity model and effectively promotes the understanding of lunar interior structure and the reliability of lunar satellite orbit determination. Finally, we analyze the deficiency of current lunar gravity models and give a perspective of future space tracking techniques.
Comparative analysis of the transcriptome of injured nerve segments reveals spatiotemporal responses to neural damage in mice
Authors: Shin Jung Eun , Ha Hongseok , Cho Eun Hye , Kim Yoon Ki , Cho Yongcheol 
Published: February 2018

AbstractNerves are particularly vulnerable to damage due to their unique structure with meter‐long axons. In the peripheral nervous system neurons and Schwann cells can activate the injury‐response program that directs axons to either regenerate or degenerate after traumatic nerve injury. However, the differences between the genetic programs driving nerve regeneration and degeneration have not yet been described extensively. To understand these differences, in this study we have compared the injury‐induced transcriptomic changes between the regenerating proximal segment and the degenerating distal segment of a transected nerve, at different post‐injury time points. We analyzed the spatiotemporal dynamics of the mouse transcriptome using a sciatic nerve‐injury model by means of RNA sequencing. The results of the differentially regulated genes (DEGs) analysis show that some DEG groups are similarly regulated in both proximal and distal segments, and primarily display a positive correlation. However, some DEG groups are exclusively regulated in either the proximal or the distal segment, suggesting that these DEG groups constitute a genetic network for distinguishing the regenerative and degenerative responses. In addition, our gene ontology analysis revealed an enrichment of particular biological processes in different phases and locations. Thus, our data provide a spatiotemporal profile of the transcriptomes that are differentially regulated in either regenerating or degenerating nerves, in vivo. The specific biological processes enriched in the DEG groups might delineate the injury‐responsive program that induces contrasting regenerative and degenerative responses in different nerve segments.
Development of ON and OFF cholinergic amacrine cells in the human fetal retina
Authors: Zhang Chi , Yu Wan‐Qing , Hoshino Akina , Huang Jing , Rieke Fred , Reh Thomas A. , Wong Rachel O.L. 
Published: February 2018

AbstractCholine acetyltransferase (ChAT) expressing retinal amacrine cells are present across vertebrates. These interneurons play important roles in the development of retinal projections to the brain and in motion detection, specifically in generating direction‐selective responses to moving stimuli. ChAT amacrine cells typically comprise two spatially segregated populations that form circuits in the ‘ON’ or ‘OFF’ synaptic layers of the inner retina. This stereotypic arrangement is also found across the adult human retina, with the notable exception that ChAT expression is evident in the ON but not OFF layer of the fovea, a region specialized for high‐acuity vision. We thus investigated whether the human fovea exhibits a developmental path for ON and OFF ChAT cells that is retinal location‐specific. Our analysis shows that at each retinal location, human ON and OFF ChAT cells differentiate, form their separate synaptic layers, and establish non‐random mosaics at about the same time. However, unlike in the adult fovea, ChAT immunostaining is initially robust in both ON and OFF populations, up until at least mid‐gestation. ChAT expression in the OFF layer in the fovea is therefore significantly reduced after mid‐gestation. OFF ChAT cells in the human fovea and in the retinal periphery thus follow distinct maturational paths.
Unsupervised Screening of Vibrational Spectra by Principal Component Analysis for Identifying Molecular Clusters
Authors: Kiefer Johannes , Eisen Kristina 
Published: February 2018

AbstractVibrational spectra are commonly used to study molecular interactions in solutions. However, the data analysis is often demanding and requires significant experience in order to obtain meaningful results. This study demonstrates that principal component analysis (PCA) can serve as an unsupervised tool for initial screening of non‐ideal mixture systems. Taking the aqueous solutions of dimethyl sulfoxide (DMSO) as an example, PCA reveals—easily and fast—the two prominent stoichiometries at 1:2 and 1:1 molar DMSO:water ratio and significantly outperforms elaborate spectral profile analysis or common algorithms as indirect hard modeling (IHM) or multivariate curve resolution (MCR). The corresponding molecular 1:1 and 1:2 clusters are known to be dominating configurations in the solutions.
Nucleation Control and Separation of Stable and Metastable Polymorphs of L‐histidine Through Novel Swift Cooling Crystallization Process
Authors: Supriya Sundareswaran , Sivan Settu , Srinivasan Karuppannan 
Published: February 2018

AbstractNucleation control, separation and crystal growth of polymorphic forms of the well‐known amino acid L‐histidine from pure aqueous solution is investigated by adopting the novel swift cooling crystallization process for the first time. The concomitant nucleation behavior of the stable orthorhombic and metastable monoclinic polymorphs of L‐histidine is investigated under different supersaturation conditions. While lower‐level of supersaturation favours the nucleation of stable polymorph, higher‐level supersaturation favours the nucleation of metastable polymorph of L‐histidine. By this way, the nucleated concomitant polymorphs of L‐histidine are separated successfully and grown as single crystals from pure aqueous solution without using any additives or anti‐solvents. Morphology of the nucleated polymorphs are identified through optical microscopy and confirmed by optical goniometry. Also, the morphological importance of different growth faces is evaluated. The distinction in the crystal system of the two polymorphs is identified by powder X‐ray diffraction (PXRD) and their crystallographic unit cell structure is refined by single crystal X‐ray diffraction (SCXRD) analyses. The thermal stability of the grown polymorphs is judged through differential scanning calorimetry (DSC). Results suggest that the supersaturation plays a key role in the nucleation and growth behaviour of the stable and metastable polymorphs of L‐histidine in aqueous solution.
Simulated eutrophication and browning alters zooplankton nutritional quality and determines juvenile fish growth and survival
Authors: Taipale Sami Johan , Kahilainen Kimmo Kalevi , Holtgrieve Gordon William , Peltomaa Elina Talvikki 
Published: February 2018

AbstractThe first few months of life is the most vulnerable period for fish and their optimal hatching time with zooplankton prey is favored by natural selection. Traditionally, however, prey abundance (i.e., zooplankton density) has been considered important, whereas prey nutritional composition has been largely neglected in natural settings. High‐quality zooplankton, rich in both essential amino acids (EAAs) and fatty acids (FAs), are required as starting prey to initiate development and fast juvenile growth. Prey quality is dependent on environmental conditions, and, for example, eutrophication and browning are two major factors defining primary producer community structures that will directly determine the nutritional quality of the basal food sources (algae, bacteria, terrestrial matter) for zooplankton. We experimentally tested how eutrophication and browning affect the growth and survival of juvenile rainbow trout (Oncorhynchus mykiss) by changing the quality of basal resources. We fed the fish on herbivorous zooplankton (Daphnia) grown with foods of different nutritional quality (algae, bacteria, terrestrial matter), and used GC‐MS, stable isotope labeling as well as bulk and compound‐specific stable isotope analyses for detecting the effects of different diets on the nutritional status of fish. The content of EAAs and omega‐3 (ω‐3) polyunsaturated FAs (PUFAs) in basal foods and zooplankton decreased in both eutrophication and browning treatments. The decrease in ω‐3 PUFA and especially docosahexaenoic acid (DHA) was reflected to fish juveniles, but they were able to compensate for low availability of EAAs in their food. Therefore, the reduced growth and survival of the juvenile fish was linked to the low availability of DHA. Fish showed very low ability to convert alpha‐linolenic acid (ALA) to DHA. We conclude that eutrophication and browning decrease the availability of the originally phytoplankton‐derived DHA for zooplankton and juvenile fish, suggesting bottom‐up regulation of food web quality.
Depressed hydraulic redistribution of roots more by stem refilling than by nocturnal transpiration for Populus euphratica Oliv. in situ measurement
Authors: Yu Tengfei , Feng Qi , Si Jianhua , Mitchell Patrick J. , Forster Michael A. , Zhang Xiaoyou , Zhao Chunyan 
Published: February 2018

AbstractDuring the night, plant water loss can occur either through the roots, as hydraulic redistribution (HR), or through the leaves via the stoma, as nocturnal transpiration (En), which was methodologically difficult to separate from stem refilling (Re). While HR and En have been reported across a range of species, ecosystem, and climate zone, there is little understanding on the interactions between En and/or Re and HR. As water movement at night occurs via gradients of water potential, it is expected that during periods of high atmospheric vapor pressure deficit (VPD), water loss via En will override water loss via HR. To test this hypothesis, sap flow in stems and roots of Populus euphratica Oliv. trees, growing in a riparian zone in a hyperarid climate, was measured once in a year. Nocturnal stem sap flow was separated into En and Re using the “forecasted refilling” method. Substantial nocturnal sap flow (38% of 24‐hr flux on average) was observed and positively correlated with VPD; however, the strength of the correlation was lower (R2 = .55) than diurnal sap flow (Ed) (R2 = .72), suggesting that nocturnal stem sap flow was attributed to both water loss through the canopy and replenishment of water in stem tissues. Partitioning of nocturnal sap flow shows that Re constituted approximately 80%, and En ~20%, of nocturnal sap flow. The amount of root sap flow attributed to redistribution was negatively related to Ed (R2 = .69) and the amount of acropetally sap flow in stems, Re (R2 = .41) and En (R2 = .14). It was suggested that the magnitude of HR is more strongly depressed by Re that was recharge to the water loss via Ed than by En. It was consistent with whole‐tree water balance theory, that the nighttime upward sap flow to xylem, stem refilling and transpiration, may depress hydraulic redistribution of roots.
Geographic range velocity and its association with phylogeny and life history traits in North American woody plants
Authors: Harnik Paul G. , Maherali Hafiz , Miller Joshua H. , Manos Paul S. 
Published: February 2018

AbstractThe geographic ranges of taxa change in response to environmental conditions. Yet whether rates of range movement (biotic velocities) are phylogenetically conserved is not well known. Phylogenetic conservatism of biotic velocities could reflect similarities among related lineages in climatic tolerances and dispersal‐associated traits. We assess whether late Quaternary biotic velocities were phylogenetically conserved and whether they correlate with climatic tolerances and dispersal‐associated traits. We used phylogenetic regression and nonparametric correlation to evaluate associations between biotic velocities, dispersal‐associated traits, and climatic tolerances for 28 woody plant genera and subgenera in North America. The velocities with which woody plant taxa shifted their core geographic range limits were positively correlated from time step to time step between 16 and 7 ka. The strength of this correlation weakened after 7 ka as the pace of climate change slowed. Dispersal‐associated traits and climatic tolerances were not associated with biotic velocities. Although the biotic velocities of some genera were consistently fast and others consistently slow, biotic velocities were not phylogenetically conserved. The rapid late Quaternary range shifts of plants lacking traits that facilitate frequent long‐distance dispersal has long been noted (i.e., Reid's Paradox). Our results are consistent with this paradox and show that it remains robust when phylogenetic information is taken into account. The lack of association between biotic velocities, dispersal‐associated traits, and climatic tolerances may reflect several, nonmutually exclusive processes, including rare long‐distance dispersal, biotic interactions, and cryptic refugia. Because late Quaternary biotic velocities were decoupled from dispersal‐associated traits, trait data for genera and subgenera cannot be used to predict longer‐term (millennial‐scale) floristic responses to climate change.