bluuebunny/crossref_metadata_2025_split huggingface dataset:
“The dearest of our possessions”: Applying Floridi's information privacy concept in models of information behavior and information literacy
Authors: Bawden David , Robinson Lyn 
Published: May 2020

AbstractThis conceptual article argues for the value of an approach to privacy in the digital information environment informed by Luciano Floridi's philosophy of information and information ethics. This approach involves achieving informational privacy, through the features of anonymity and obscurity, through an optimal balance of ontological frictions. This approach may be used to modify models for information behavior and for information literacy, giving them a fuller and more effective coverage of privacy issues in the infosphere. For information behavior, the Information Seeking and Communication Model and the Information Grounds conception are most appropriate for this purpose. For information literacy, the metaliteracy model, using a modification a privacy literacy framework, is most suitable.
Sustainable environmental practices and financial performance: Evidence from listed small and medium‐sized enterprise in the United Kingdom
Authors: Boakye Danquah Jeff , TIngbani Ishmael , Ahinful Gabriel , Damoah Isaac , Tauringana Venancio 
Published: May 2020

AbstractIn this article, we investigate the financial implication of sustainable environmental practices on UK small and medium‐sized enterprises (SMEs)–traded firms. Existing literature indicates that there is a direct relationship between sustainable environmental practices and financial performance. However, studies looking at this relationship have focused mainly on large firms with little attention paid to SMEs. Further, those looking at environmental and financial performance relationships have often used a single measure of performance in their studies. This study bridges these research gaps by focusing on listed SMEs in the United Kingdom using multiple measures of sustainable environmental policy indices on a panel of 201 SMEs on the Alternative Investment Market from 2011 to 2016. Evidence from our panel data analysis suggests significant and a nonlinear (concave) relationship between sustainable environmental practices and firms' financial performance. Specifically, energy efficiency practices, greenhouse gases, material, and resource efficiency revealed an inverted U‐shaped relationship with financial performance. The results will offer guidance to management in terms of allocating resources to sustainable environmental practices investment.
Anatomical study of the pial arterial network in human spinal cords
Authors: Rojas Santiago , Ortega Marisa , Rodríguez‐Baeza Alfonso 
Published: May 2020

AbstractIntroductionMultiple collaterals originate from three main longitudinal vessels to perfuse the human spinal cord. Only a few classic studies published in the last century have investigated these collaterals. The current work proposes a possible classification of these vessels and analyzes their relative abundance along spinal cord segments.Materials and MethodsHuman spinal cords (n = 30) from male and female cadavers were injected with colored latex through the vertebral, ascending cervical, costocervical trunk and segmental arteries and then fixed in formaldehyde solution. Afterwards, spinal vessels were dissected and the relative abundances of each type of collateral were quantified and compared between different spinal cord segments.ResultsCollaterals of the anterior longitudinal pathway can be classified as central arteries and arteries for the anterior and lateral columns. Collaterals for the anterior column can be classified into two types: anteromedial and anterolateral. Arteries for the lateral column can be classified, according to their relationship with the dentate ligament, as either preligamentous or post‐ligamentous. The collaterals of posterior longitudinal pathways can be divided between those for the posterior and those for the lateral column. In turn, the arteries for the posterior column can be classified into three types: median posterior, posteromedial and posterolateral. The collaterals for the lateral column were also classified as either pre‐ or post‐ligamentous.ConclusionThe relative abundance of the various types of collateral and anastomoses between longitudinal pathways was inhomogeneous along the spinal cord, with several statistically significant differences observed between spinal segments.
Conformational Selection as the Driving Force of Amyloid β Chiral Inactivation
Authors: Raskatov Jevgenij A. 
Published: May 2020

AbstractWe recently introduced amyloid β chiral inactivation (Aβ‐CI) as a molecular approach that uses mirror‐image peptides to chaperone the natural Aβ stereoisomer into a less toxic state. The oligomer‐to‐fibril conversion mechanism remains the subject of active research. Perhaps the most striking feature of Aβ‐CI is the virtual obliteration of the incubation/induction phase that is so characteristic of Aβ fibril formation kinetics. This qualitative change is indicative of the distinct mechanistic pathway Aβ‐CI operates through. The current working model of Aβ‐CI invokes the formation of “rippled” cross‐β sheets, in which alternating l‐ and d‐peptide strands form periodic networks. However, the assumption of rippled cross‐β sheets does not per se explain the dramatic changes in reaction kinetics upon mixing of Aβ enantiomers. Herein, it is shown by DFT computational methods that the individual peptide strands in rippled cross‐β networks are less conformationally strained than their pleated counterparts. This means that the adoption of fibril‐seeding conformations is more probable for rippled cross‐β. Conformational selection is thus suggested as the mechanistic rationale for the acceleration of fibril formation upon Aβ‐CI.
Thiol‐Disulfide Exchange Reaction Promoted Highly Efficient Cellular Uptake of Pyridyl Disulfide Appended Nonionic Polymers
Authors: Bej Raju , Ghosh Arijit , Sarkar Jayita , Das Benu Brata , Ghosh Suhrit 
Published: May 2020

AbstractThe intracellular transport of molecules, macromolecules or materials is a key step in probing cellular structure and function, as well as regulating a plethora of physical and chemical events for treating disease. This communication reveals direct cellular uptake of pyridyl‐disulfide (Py−Ds)‐conjugated nonionic and biocompatible macromolecules with the aid of rapid exchange of the highly reactive Py−Ds groups with exofacial cell‐surface thiols. Confocal microscopy and flow cytometry analysis confirmed highly efficient cellular uptake of Py−Ds‐appended polymers (>50 % in 15 min) by avoiding lysosome as a consequence of thiol‐disulfide exchange in the cell surface. In contrast, a control polymer lacking the Py−Ds group followed caveolae‐mediated endocytosis. Other control polymers containing either the pyridine group (but not disulfide) or the disulfide group (but not pyridine) revealed significantly low cellular uptake, and thus essential role of the highly reactive Py−Ds group was established beyond doubt.
Comparison of acute recoil after valve deployment and after post‐dilation in patients undergoing transfemoral‐transcatheter aortic valve replacement with SAPIEN‐3 valve
Authors: Sammour Yasser , Kadri Amer N. , Gajulapalli Rama Dilip , Kaur Manpreet , Bazarbashi Najdat , Banerjee Kinjal , Karrthik Antonette , Dhaliwal Kamalpreet , Burns Daniel , Yun James , Krishnaswamy Amar , Kapadia Samir R. 
Published: May 2020

AbstractBackgroundTranscatheter aortic valves are prone to acute recoil similar to the metal‐based coronary stents. However, it is not clear if recoil remains a factor only after the initial valve deployment or also after post‐dilation.MethodsWe conducted a retrospective observational study of patients who underwent transfemoral transcatheter aortic valve replacement (TAVR) with SAPIEN‐3 valve. Acute recoil at the upper, central, and lower levels of the valve was calculated in both anteroposterior right anterior oblique (RAO) and lateral left anterior oblique (LAO) views after initial deployment as well as after post‐dilation. The average recoil of the RAO and LAO views was also calculated and described as RAO/LAO.ResultsThe acute recoil in the RAO/LAO views (mean ± SD) was 3.9 ± 1.1% after valve deployment in the whole study population (n = 257). Among the subset of patients who required post‐dilation (n = 133), the mean acute recoil in the RAO/LAO views was found to be greater after initial valve deployment as compared with after post‐dilation (3.8 ± 1.1% vs. 3.0 ± 0.9%; p < .001). Further, acute recoil was significantly greater in the RAO view than the LAO view and at the central level of the prosthesis as compared with the upper and lower levels. Those findings were consistent after initial deployment as well as after post‐dilation. Clinical outcomes were similar between patients who required post‐dilation compared to those who did not. In multivariable logistic regression analysis, only smaller valve cover index was found to be an independent predictor of 30‐day mild or greater aortic regurgitation (OR 0.007; 95% CI 0.0001–0.707; p = .035).ConclusionAcute elastic recoil of the SAPIEN‐3 valve was significantly less after post‐dilation as compared with after deployment. It was also greater when measured in the RAO view as compared with the LAO view. Furthermore, acute recoil was not homogenous across the height of the valve stent frame.
SBA‐15 Supported Chiral Phosphine‐Gold(I) Complex: Highly Efficient and Recyclable Catalyst for Asymmetric Cycloaddition Reactions
Authors: Yan Dong , Wang Nannan , Xue Teng , Wu Haihong , Zhang Junliang , Wu Peng 
Published: May 2020

AbstractOrdered mesoporous SBA‐15 supported chiral phosphine gold (I) complexes were successfully developed. The gold(I) complexes were covalently immobilized on mercaptopropyl modified SiO2 surface through radical reaction. In this way, the chiral carbon and chiral sulfur of the homogenous catalyst were perfectly remained in situ. And thus, the prepared catalysts demonstrated highly effective asymmetric cycloaddition activity, which was likely because the chiral induction effect of the Au complex was hardly influenced by this immobilization method. Moreover, they could be easily recovered by simple filtration and directly used for the subsequent catalytic runs. The prepared catalyst was highly stable and efficient without obvious activity loss after eight cycles.
Flow Photochemistry as a Tool in Organic Synthesis
Authors: Rehm Thomas H. 
Published: May 2020

AbstractPhotochemical transformations of molecular building blocks have become an important and widely recognized research field in the past decade. Detailed and deep understanding of novel photochemical catalysts and reaction concepts with visible light as the energy source has enabled a broad application portfolio for synthetic organic chemistry. In parallel, continuous‐flow chemistry and microreaction technology have become the basis for thinking and doing chemistry in a novel fashion with clear focus on improved process control for higher conversion and selectivity. As can be seen by the large number of scientific publications on flow photochemistry in the recent past, both research topics have found each other as exceptionally well‐suited counterparts with high synergy by combining chemistry and technology. This review will give an overview on selected reaction classes, which represent important photochemical transformations in synthetic organic chemistry, and which benefit from mild and defined process conditions by the transfer from batch to continuous‐flow mode.
Molecular Engineering of Metal Alkoxides for Solution Phase Synthesis of High‐Tech Metal Oxide Nanomaterials
Authors: Mishra Shashank , Daniele Stéphane 
Published: May 2020

AbstractThe ‘bottom‐up’ synthesis of inorganic nanomaterials with precision at the atomic/molecular level offers many opportunities for the design and improvement of the nanomaterials for various applications. Molecular engineering during soft chemical processing for the synthesis of functional nanomaterials enables the desired chemical and physical properties of the precursors, such as solubility or volatility, clean decomposition, control of stoichiometry for multimetallic species to name a few, and leads to easy control of uniform particle size distribution, stoichiometry…. This Minireview illustrates some important aspects of the molecular engineering in light of some recent developments from the molecular synthesis of nanomaterials involving non‐silicon metal alkoxide systems for high‐tech applications.
Ferrimagnetic Ordering and Anomalous Stoichiometry Observed for the Cubic, Extended 3D Prussian Blue Analogues (NEt3Me)2MnII5(CN)12 and (NEt2Me2)2MnII5(CN)12: A Cation‐Adaptive Structure
Authors: Graham Adora G. , Lapidus Saul H. , Hawkins Casey G. , Stephens Peter W. , Miller Joel S. 
Published: May 2020

AbstractThe reactions of MnII(O2CCH3)2 with NEt3Me+CN− and NEt2Me2+CN− form (NEt3Me)2MnII5(CN)12 (1) and (NEt2Me2)2MnII5(CN)12 (2), respectively. Structure model‐building and Rietveld refinement of high‐resolution synchrotron powder diffraction data revealed a cubic [a=24.0093 Å (1), 23.8804 Å (2)] 3D extended structural motif with adjacent tetrahedral and octahedral MnII sites in a 3:2 ratio. Each tetrahedral MnII site is surrounded by four low‐spin octahedral MnII sites, and each octahedral MnII site is surrounded by six high‐spin tetrahedral MnII sites; adjacent sites are antiferromagnetically coupled in 3D. Compensation does not occur, and magnetic ordering as a ferrimagnet is observed at Tc=13 K for 2 based on the temperature at which remnant magnetization, Mr(T)→0. The hysteresis has an unusual constricted shape with inflection points around 50 and 1.2 kOe with a 5 K coercivity of 16 Oe and remnant magnetization, Mr, of 2050 emuOe mol−1. The unusual structure and stoichiometry are attributed to the very ionic nature of the high‐spin N‐bonded MnII ion, which enables the maximization of the attractive van der Waals interactions through minimization of void space via a reduced ∠ MnNC. This results in an additional example of the AxMnIIy(CN)x+2y (x=0, y=1; x=1, y=3; x=2, y=1; x=2, y=2; x=2, y=3; x=3, y=5; and x=4, y=1) family of compounds possessing an unprecedented stoichiometry and lattice motif that are cation adaptive structured materials.
An Intramolecular Hydrogen‐Shift in a Peroxy Radical at Cryogenic Temperatures: The Reaction of 2‐Hydroxyphenyl Radical with O2
Authors: Wagner J. Philipp 
Published: May 2020

AbstractPeroxy radical hydrogen‐shifts are pivotal elementary reaction steps in the oxidation of small hydrocarbons in autoignition and the lower atmosphere. Although these reactions are typically associated with a substantial barrier, we demonstrate that the [1,5]H‐shift in the peroxy species derived from the 2‐hydroxyphenyl radical1is so facile that it even proceeds rapidly in an argon matrix at 35 K through a proton‐coupled electron transfer mechanism. Hydrogen‐bound complexes ofo‐benzoquinone are identified as the main reaction products by infrared spectroscopy although their formation through O−O bond scission is hampered by a barrier of 11.9 kcal mol−1at the ROCCSD(T)/cc‐pVTZ/UB3LYP/6–311G(d,p) level of theory.
Self‐Assembly Propensity Dictates Lifetimes in Transient Naphthalimide–Dipeptide Nanofibers
Authors: Kumar Mohit , Sementa Deborah , Narang Vishal , Riedo Elisa , Ulijn Rein V. 
Published: May 2020

AbstractTransient self‐assembly of dipeptide nanofibers with lifetimes that are predictably variable through dipeptide sequence design are presented. This was achieved using 1,8‐naphthalimide (NI) amino acid methyl‐esters (Phe, Tyr, Leu) that are biocatalytically coupled to amino acid‐amides (Phe, Tyr, Leu, Val, Ala, Ser) to form self‐assembling NI‐dipeptides. However, competing hydrolysis of the dipeptides results in disassembly. It was demonstrated that the kinetic parameters like lifetimes of these nanofibers can be predictably regulated by the thermodynamic parameter, namely the self‐assembly propensity of the constituent dipeptide sequence. These lifetimes could vary from minutes, to hours, to permanent gels that do not degrade. Moreover, the in‐built NI fluorophore was utilized to image the transient nanostructures in solution with stimulated emission depletion (STED) based super‐resolution fluorescence microscopy.
Second Comes First: Switching Elementary Steps in Palladium‐Catalyzed Cross‐Coupling Reactions
Authors: Kolter Marlene , Koszinowski Konrad 
Published: May 2020

AbstractThe electron‐poor palladium(0) complex L3Pd (L=tris[3,5‐bis(trifluoromethyl)phenyl]phosphine) reacts with Grignard reagents RMgX and organolithium compounds RLi via transmetalation to furnish the anionic organopalladates [L2PdR]−, as shown by negative‐ion mode electrospray‐ionization mass spectrometry. These palladates undergo oxidative additions of organyl halides R′X (or related SN2‐type reactions) followed by further transmetalation. Gas‐phase fragmentation of the resulting heteroleptic palladate(II) complexes results in the reductive elimination of the cross‐coupling products RR′. This reaction sequence corresponds to a catalytic cycle, in which the order of the elementary steps of transmetalation and oxidative addition is switched relative to that of palladium‐catalyzed cross‐coupling reactions proceeding via neutral intermediates. An attractive feature of the palladate‐based catalytic system is its ability to mediate challenging alkyl–alkyl coupling reactions. However, the poor stability of the phosphine ligand L against decomposition reactions has so far prevented its successful use in practical applications.
Density Functional Theory Study of Pd Aggregation on a Pyridine‐Terminated Self‐Assembled Monolayer
Authors: Yao Zhen , Buck Manfred , Bühl Michael 
Published: May 2020

AbstractBy using density functional theory calculations, the initial steps towards Pd metal cluster formation on a pyridine‐terminated self‐assembled monolayer (SAM) consisting of 3‐(4‐(pyridine‐4‐yl)phenyl)propane‐1‐thiol on an Au(1 1 1) surface are investigated. Theoretical modelling allows the investigation of structural details of the SAM surface and the metal/SAM interface at the atomic level, which is essential for elucidating the nature of Pd–SAM and Pd–Pd interactions at the liquid/solid interface and gaining insight into the mechanism of metal nucleation in the initial stage of electrodeposition. The structural flexibility of SAM molecules was studied first and the most stable conformation was identified, planar molecules in a herringbone packing, as the model for Pd adsorption. Two binding sites are found for Pd atoms on the pyridine end group of the SAM. The strong interaction between Pd atoms and pyridines illustrates the importance of SAM functionalisation in the metal nucleation process. Consistent with an energetic driving force of approximately −0.3 eV per Pd atom towards Pd aggregation suggested by static calculations, a spontaneous Pd dimerisation is observed in ab initio molecular dynamic studies of the system. Nudged elastic band calculations suggest a potential route with a low energy barrier of 0.10 eV for the Pd atom diffusion and then dimerisation on top of the SAM layer.
Atomic‐Scale Dispersed Fe‐Based Catalysts Confined on Nitrogen‐Doped Graphene for Li‐S Batteries: Polysulfides with Enhanced Conversion Efficiency
Authors: Cao Guiqiang , Wang Zhikang , Bi Da , Zheng Jing , Lai Qingxue , Liang Yanyu 
Published: May 2020

AbstractLithium‐sulfur batteries have been considered as potential electrochemical energy‐storage devices owing to their satisfactory theoretical energy density. Nonetheless, the inferior conversion efficiency of polysulfides in essence leads to fast capacity decay during the discharge/charge cycle. In this work, it is successfully demonstrated that the conversion efficiency of lithium polysulfides is remarkably enhanced by employing a well‐distributed atomic‐scale Fe‐based catalyst immobilized on nitrogen‐doped graphene (Fe@NG) as a coating of separator in lithium‐sulfur batteries. The quantitative electrocatalytic efficiency of the conversion of lithium polysulfides is determined through cyclic voltammetry. It is also proven that the Fe‐NX configuration with highly catalytic activity is quite beneficial for the conversion of lithium polysulfides. In addition, the adsorption and permeation experiments distinctly indicate that the strong anchoring effect, originated from the charge redistribution of N doping into the graphene matrix, inhibits the movement of lithium polysulfides. Thanks to these advantages, if the as‐prepared Fe@NG catalyst is combined with polypropylene and applied as a separator (Fe@NG/PP) in Li‐S batteries, a high initial capacity (1616 mA h g−1 at 0.1 C), excellent capacity retention (93 % at 0.2 C, 70 % at 2 C), and superb rate performance (820 mA h g−1 at 2 C) are achieved.
Finely Controlled Platinum Nanoparticles over ZnO Nanorods for Selective Hydrogenation of 3‐Nitrostyrene to 3‐Vinylaniline
Authors: Gao Tongtong , Shi Wen , Zhang Ying , Zhang Liyun , Zhang Bingsen , Liu Zhong‐Wen 
Published: May 2020

AbstractMetallic platinum nanocatalysts play a key role in the liquid‐phase selective hydrogenation of substrates with more than one unsaturated bond. However, the commonly applied explanation for the effects of different electronic and geometric properties of catalysts on reactions remains of a heuristic nature due to the difficulties involved in preparing catalysts with precise structure. In this work, we have directly loaded pre‐synthesized metallic platinum nanoparticles onto well‐structured ZnO nanorods and then subjected them to thermal treatment in a reductive atmosphere for different temperatures. The effects of the different electronic and geometric properties of the catalysts on the selective reduction of 3‐nitrostyrene to 3‐vinylaniline as a model reaction have been rigorously explored through an analysis of the catalyst structures and the activity and selectivity profiles. Both the electron transfer from zinc to platinum and the decreased platinum surface density as a result of the formation of PtZn intermetallic compounds are key factors for improving the selectivity for the desired 3‐vinylaniline. Azobenzene was detected in the reaction with all the Pt/ZnO catalysts after 10–90 min, which indicates that the reaction follows a condensation mechanism.
Highly Oxidized States of Phthalocyaninato Terbium(III) Multiple‐Decker Complexes Showing Structural Deformations, Biradical Properties and Decreases in Magnetic Anisotropy
Authors: Horii Yoji , Damjanović Marko , Ajayakumar M. R. , Katoh Keiichi , Kitagawa Yasutaka , Chibotaru Liviu , Ungur Liviu , Mas‐Torrent Marta , Wernsdorfer Wolfgang , Breedlove Brian K. , Enders Markus , Veciana Jaume , Yamashita Masahiro 
Published: May 2020

AbstractPresented here is a comprehensive study of highly oxidized multiple‐decker complexes composed of TbIII and CdII ions and two to five phthalocyaninato ligands, which are stabilized by electron‐donating n‐butoxy groups. From X‐ray structural analyses, all the complexes become axially compressed upon ligand oxidation, resulting in bowl‐shaped distortions of the ligands. In addition, unusual coexistence of square antiprism and square prism geometries around metal ions was observed in +4e charged species. From paramagnetic 1H NMR studies on the resulting series of triple, quadruple and quintuple‐decker complexes, ligand oxidation leads to a decrease in the magnetic anisotropy, as predicted from theoretical calculations. Unusual paramagnetic shifts were observed in the spectra of the +2e charged quadruple and quintuple‐decker complexes, indicating that those two species are actually unexpected triplet biradicals. Magnetic measurements revealed that the series of complexes show single‐molecule magnet properties, which are controlled by the multi‐step redox induced structural changes.