bluuebunny/crossref_metadata_2025_split huggingface dataset:
Slow Magnetic Relaxation in a Palladium–Gadolinium Complex Induced by Electron Density Donation from the Palladium Ion
Authors: Izuogu David C. , Yoshida Takefumi , Zhang Haitao , Cosquer Goulven , Katoh Keiichi , Ogata Shuhei , Hasegawa Miki , Nojiri Hiroyuki , Damjanović Marko , Wernsdorfer Wolfgang , Uruga Tomoya , Ina Toshiaki , Breedlove Brian K. , Yamashita Masahiro 
Published: April 2018

AbstractIncorporating palladium in the first coordination sphere of acetato‐bridged lanthanoid complexes, [Pd2Ln2(H2O)2(AcO)10]⋅2 AcOH (Ln=Gd (1), Y (2), Gd0.4Y1.6 (3), Eu (4)), led to significant bonding interactions between the palladium and the lanthanoid ions, which were demonstrated by experimental and theoretical methods. We found that electron density was donated from the d8 Pd2+ ion to Gd3+ ion in 1 and 3, leading to the observed slow magnetic relaxation by using local orbital locator (LOL) and X‐ray absorption near‐edge structure (XANES) analysis. Field‐induced dual slow magnetic relaxation was observed for 1 up to 20 K. Complex 3 and frozen aqueous and acetonitrile solutions of 1 showed only one relaxation peak, which confirms the role of intermolecular dipolar interactions in slowing the magnetic relaxation of 1. The slow magnetic relaxation occurred through a combination of Orbach and Direct processes with the highest pre‐exponential factor (τo=0.06 s) reported so far for a gadolinium complex exhibiting slow magnetic relaxation. The results revealed that transition metal–lanthanoid (TM–Ln) axial interactions indeed could lead to new physical properties by affecting both the electronic and magnetic states of the compounds.
Metal Cluster Electrides: A New Type of Molecular Electride with Delocalised Polyattractor Character
Authors: El Bakouri Ouissam , Postils Verònica , Garcia‐Borràs Marc , Duran Miquel , Luis Josep M. , Calvello Simone , Soncini Alessandro , Matito Eduard , Feixas Ferran , Solà Miquel 
Published: April 2018

AbstractElectrides are ionic substances containing isolated electrons. These confined electrons are topologically characterised by a quasi‐atom, that is, a non‐nuclear attractor (NNA) of the electron density. The electronic structure of the octahedral4A1gLi6+and5A1gBe6species shows that these species have a large number of NNAs. These NNAs have highly delocalised electron densities and, as a result, the chemical bonding pattern of these systems is reminiscent of that in solid metals, in which metal cations are surrounded by a “sea” of delocalised valence electrons. We propose the term metal cluster electrides to refer to this new class of compounds. In this study, we establish a computational protocol to identify, characterize, and design metal cluster electrides and we elucidate the intricate bonding patterns of this particular type of species.
Design and Synthesis of Iminosydnones for Fast Click and Release Reactions with Cycloalkynes
Authors: Riomet Margaux , Decuypere Elodie , Porte Karine , Bernard Sabrina , Plougastel Lucie , Kolodych Sergii , Audisio Davide , Taran Frédéric 
Published: April 2018

AbstractEmerging applications in the field of chemical biology are currently limited by the lack of bioorthogonal reactions allowing both removal and linkage of chemical entities on complex biomolecules. We recently discovered a novel reaction between iminosydnones and strained alkynes leading to two products resulting from ligation and fragmentation of iminosydnones under physiological conditions. We now report the synthesis of a panel of substituted iminosydnones and the structure reactivity relationship between these compounds and strained alkyne partners. This study identified the most relevant substituents, which allow to increase the rate of the transformation and to develop a bifunctional cleavable linker with improved kinetics.
Probing Optical Anisotropy and Polymorph‐Dependent Photoluminescence in [Ln2] Complexes by Hyperspectral Imaging on Single Crystals
Authors: Errulat Dylan , Gabidullin Bulat , Murugesu Muralee , Hemmer Eva 
Published: April 2018

AbstractTwo homodinuclear and one heterodinuclear lanthanide (Ln)‐based complexes of the general formula [Ln2(bpm)(tfaa)6] (Ln=Eu (1), Tb (2), Eu−Tb (3), bpm=2,2′‐bipyrimidine, tfaa−=1,1,1‐trifluoroacetylacetonate) were synthesized and characterized by single‐crystal photoluminescence spectroscopy and hyperspectral imaging. Complexes 1 and 2 crystallize in two polymorphic structures, while three polymorphs were isolated for 3, namely having needle‐, plate‐, and block‐like morphologies. Single‐crystal photoluminescence spectroscopy and imaging on Eu3+‐containing 1 and 3 revealed polymorph‐dependent J‐splitting of the hypersensitive 5D0→7F2 Eu3+ transition as well as electric‐to‐magnetic dipole emission intensity ratios. According to these observations, the lowest symmetry chemical environment was attributed to the Eu3+ ions present in the needle‐like polymorph, also in agreement with single‐crystal X‐ray diffraction analysis. More importantly, hyperspectral imaging on all three single‐crystal polymorphs of 3 exhibits optical anisotropy with photoluminescence enhancement at specific crystallographic faces. This behavior was ascribed to the distinct molecular packing of the Ln−Ln dimers in each polymorphic crystal as well as to face‐specific local symmetry of the Eu3+ centers. Overall, opto‐structural relationships of three Ln−Ln dimers and their single‐crystal polymorphs were established as a particularly promising avenue for control of photoluminescence by chemical crystal engineering.
Reversible Ligand‐Centered Reduction in Low‐Coordinate Iron Formazanate Complexes
Authors: Broere Daniël L. J. , Mercado Brandon Q. , Lukens James T. , Vilbert Avery C. , Banerjee Gourab , Lant Hannah M. C. , Lee Shin Hee , Bill Eckhard , Sproules Stephen , Lancaster Kyle M. , Holland Patrick L. 
Published: April 2018

AbstractCoordination of redox‐active ligands to metals is a compelling strategy for making reduced complexes more accessible. In this work, we explore the use of redox‐active formazanate ligands in low‐coordinate iron chemistry. Reduction of an iron(II) precursor occurs at milder potentials than analogous non‐redox‐active β‐diketiminate complexes, and the reduced three‐coordinate formazanate‐iron compound is characterized in detail. Structural, spectroscopic, and computational analysis show that the formazanate ligand undergoes reversible ligand‐centered reduction to form a formazanate radical dianion in the reduced species. The less negative reduction potential of the reduced low‐coordinate iron formazanate complex leads to distinctive reactivity with formation of a new N−I bond that is not seen with the β‐diketiminate analogue. Thus, the storage of an electron on the supporting ligand changes the redox potential and enhances certain reactivity.
A Balance between van der Waals and Cation–π Interactions Stabilizes Hydrophobic Assemblies
Authors: Zhan Yi‐Yang , Kojima Tatsuo , Koide Takuya , Tachikawa Masanori , Hiraoka Shuichi 
Published: April 2018

AbstractA thermally highly stable molecular self‐assembly (nanocube) in water, the decomposition temperature of which is 415 K, was developed by designing a gear‐shaped amphiphile (GSA) with an indented hydrophobic surface, even though the nanocube is stabilized only by van der Waals (vdW) and cation–π interactions as well as the hydrophobic effect. The introduction of an electron‐donating substituent in one of the benzene rings of the GSA increased the decomposition temperature by 12 K, which is due to the stronger cation–π interactions between the benzene ring and positively charged pyridinium rings and tighter molecular meshing between the GSAs in the nanocube. The position of the substituent introduced in the benzene ring greatly affects the thermal stability of the nanocubes, and this indicates that both vdW (molecular meshing) and cation–π interactions are crucial for improving the thermal stability of the hydrophobic assemblies.
Designing the Backbone of Hexasilabenzene Derivatives with a High Unimolecular Kinetic Stability
Authors: Sumiya Yosuke , Maeda Satoshi 
Published: April 2018

AbstractIt is an important subject to theoretically predict the kinetic stability of transient species. In this study, we have studied the kinetic stability of hexasilabenzene Si6H6 and its derivatives, that is, decasilanaphthalene Si10H8 and Li‐substituted hexasilabenzene Si6Li6, theoretically by the artificial force induced reaction (AFIR) method combined with the rate constant matrix contraction (RCMC) method. Molecular design was further conducted to extend the unimolecular lifetime of hexasilabenzene derivatives. Although both Si10H8 and Si6Li6 were shown to possess shorter lifetimes than Si6H6, we found that the lifetimes of Si6Li6 changed depending on arrangements of Li atoms around the monocyclic Si6 backbone. Based on this knowledge, we found that a compound of an atomic composition Si6H4Li2 with a planar, monocyclic Si6 backbone has a relatively long unimolecular lifetime. Moreover, substitution of the two Li atoms by Na atoms further increased the lifetime.
Fluorescent DNA‐Templated Silver Nanoclusters from Silver(I)‐Mediated Base Pairs
Authors: Léon J. Christian , González‐Abradelo Darío , Strassert Cristian A. , Müller Jens 
Published: April 2018

AbstractSilver nanoclusters (AgNCs) stabilized by double‐stranded DNA (dsDNA) are of special interest because the duplex structures provide rigidity and chirality that can be transferred to the metal clusters. This work reports fluorescent AgNCs obtained from dsDNA templates containing artificial ligand‐derived nucleobases. They are compared with fluorescent AgNCs obtained from DNA templates containing C:C mismatches (C, cytosine). Towards this end, the new metal‐mediated Im−AgI−C base pair composed of imidazole (Im) and cytosine was introduced into dsDNA and reduced to form AgNCs. The clusters were characterized by UV/Vis, fluorescence and circular dichroism spectroscopy. The AgNCs form chiral aggregates with dsDNA. Their optical properties are highly sequence‐dependent. As a result, a simple method to detect a cytosine insertion into a run of cytosine residues in a duplex is proposed using the human CDH1 gene as an example.
Halogens – light emission and fire
Authors: Weiß Dieter , Täuscher Eric , Brandl† Herbert 
Published: April 2018

AbstractDie Stoffgruppe der Halogene stellen, bedingt durch ihre Eigenschaften, Reaktivität und Ubiquität ein zentrales Thema in jedem Chemieunterricht dar. Nach zahlreichen Debatten in den letzten Jahren über die Sicherheit bei den Experimenten mit Halogenen soll dieser Artikel eindrucksvolle, didaktisch wertvolle, sichere und funktionierende Reaktionen mit den Halogenen aufzeigen. Licht oder Feuer erzeugende Reaktionen, haben sich als besonders einprägsam herausgestellt, so dass eben solche hier ausgewählt wurden. Dabei wird explizit auf den sicheren Umgang mit Halogenen eingegangen.
Improvement in clinical outcomes of patients with heart failure and active cocaine use after β‐blocker therapy
Authors: Lopez Persio D. , Akinlonu Adedoyin , Mene‐Afejuku Tuoyo O. , Dumancas Carissa , Saeed Mohammed , Cativo Eder H. , Visco Ferdinand , Mushiyev Savi , Pekler Gerald 
Published: April 2018

BackgroundCocaine use has a high prevalence in the United States and can be associated with significant cardiovascular disease, even in asymptomatic users. β‐Adrenergic receptor hyperactivation is the underlying pathophysiologic pathway of cocaine cardiotoxicity. β‐Blocker therapy is controversial in patients with active cocaine use.Hypothesisβ‐Blocker therapy is associated with clinical improvement in patients with heart failure despite active cocaine use.MethodsIn a single‐center, retrospective chart analysis, patients with newly diagnosed heart failure and active cocaine use who had been started on β‐blocker therapy were reviewed. The New York Heart Association (NYHA) functional class and the left ventricular ejection fraction (LVEF) were recorded at baseline and after 12 monthsnthsnths of β‐blocker use. Patients were excluded if they had been on prior β‐blocker therapy, had other reasons for volume overload, had chronic kidney disease stages G4 or G5, or had a life expectancy <12 months.ResultsThirty‐eight patients were identified; most were African American males. A statistically significant improvement was found in both NYHA functional class (P < 0.0001) and LVEF (P < 0.0001) after 12 months of β‐blocker therapy. No major adverse cardiovascular events occurred in this population.Conclusionsβ‐Blocker use in cocaine users with heart failure with a reduced ejection fraction is associated with a lower NYHA functional class and a higher LVEF at 12‐month follow‐up. No major adverse cardiovascular events were observed.
Early effects of empagliflozin on exercise tolerance in patients with heart failure: A pilot study
Authors: Núñez Julio , Palau Patricia , Domínguez Eloy , Mollar Anna , Núñez Eduardo , Ramón Jose María , Miñana Gema , Santas Enrique , Fácila Lorenzo , Górriz Jose Luis , Sanchis Juan , Bayés‐Genís Antoni 
Published: April 2018

BackgroundSodium‐glucose linked transporter 2 inhibition recently emerged as a promising therapy for reducing the risk of heart failure (HF) in patients with type 2 diabetes mellitus (T2DM). However, there is a lack of data endorsing its role in symptomatic HF patients. We sought to evaluate the short‐term effects of empagliflozin on maximal exercise capacity in these patients.HypothesisWe postulate tretament with empagliflozin may improve functional capacity in patients with T2DM and established HF.MethodsNineteen T2DM patients with symptomatic HF were prospectively included and underwent cardiopulmonary exercise testing before and 30 days after initiation of empagliflozin therapy. A mixed‐effects model for repeated measures was used.ResultsMedian patient age was 72 years (interquartile range, 60–79 years); 42.1% were in New York Heart Association class III. Baseline mean (± SD) peak oxygen consumption (peak VO2) was 10.9 ± 4.0 mL/min/kg. Peak VO2 increased significantly at 30 days (∆: +1.21 [0.66 to 1.76] mL/min/kg; P < 0.001). A significant improvement in ventilatory efficiency during exercise, 6‐minute walking distance, and quality of life, and a reduction in antigen carbohydrate 125, were also found. Estimated glomerular filtration rate and natriuretic peptides did not significantly change.ConclusionsIn this pilot study, empagliflozin was associated with 1‐month improvement in exercise capacity in T2DM patients with symptomatic HF. This beneficial effect was also found for other surrogates of severity.
Prognostic value of exercise capacity among patients with treated depression: The Henry Ford Exercise Testing (FIT) Project
Authors: Ahmed Amjad M. , Qureshi Waqas T. , Sakr Sherif , Blaha Michael J. , Brawner Clinton A. , Ehrman Jonathan K. , Keteyian Steven J. , Al‐Mallah Mouaz H. 
Published: April 2018

BackgroundExercise capacity is associated with survival in the general population. Whether this applies to patients with treated depression is not clear.HypothesisHigh exercise capacity remains associated with lower risk of all‐cause mortality (ACM) and nonfatal myocardial infraction (MI) among patients with treated depression.MethodsWe included 5128 patients on antidepressant medications who completed a clinically indicated exercise stress test between 1991 and 2009. Patients were followed for a median duration of 9.4 years for ACM and 4.5 years for MI. Exercise capacity was estimated in metabolic equivalents of tasks (METs). Cox proportional hazards regression models were used.ResultsPatients with treated depression who achieved ≥12 METs (vs those achieving <6 METs) were younger (age 46 ± 9 vs 61 ± 12 years), more often male (60% vs 23%), less often black (10% vs 27%), and less likely to be hypertensive (51% vs 86%), have DM (9% vs 38%), or be obese (11% vs 36%) or dyslipidemic (45% vs 54%). In the fully adjusted Cox proportional hazard regression model, exercise capacity was associated with a lower ACM (HR per 1‐MET increase in exercise capacity: 0.82, 95% CI: 0.79–0.85, P < 0.001) and nonfatal MI (HR: 0.92, 95% CI: 0.87–0.97, P = 0.004).ConclusionsExercise capacity had an inverse association with both ACM and nonfatal MI in patients with treated depression, independent of cardiovascular risk factors. These results highlight the potential impact of assessing exercise capacity to identify risk, as well as promoting an active lifestyle among treated depression patients.
Interactions of β tubulin isotypes with glutathione in differentiated neuroblastoma cells subject to oxidative stress
Authors: Guo Jiayan , Kim Hong Seok , Asmis Reto , Ludueña Richard F. 
Published: April 2018

AbstractMicrotubules are a major component of the neuronal cytoskeleton. Tubulin, the subunit protein of microtubules, is an α/β heterodimer. Both α and β exist as families of isotypes, whose members are encoded by different genes and have different amino acid sequences. The βII and βIII isotypes are very prominent in the nervous system. Our previous work has suggested that βII may play a role in neuronal differentiation, but the role of βIII in neurons is not well understood. In the work reported here, we examined the roles of the different β‐tubulin isotypes in response to glutamate/glycine treatment, and found that both βII and βIII bind to glutathione in the presence of ROS, especially βIII. In contrast, βI did not bind to glutathione. Our results suggest that βII and βIII, but especially βIII, may play an important role in the response of neuronal cells to stress. In view of the high levels of βII and βIII expressed in the nervous system it is conceivable that these tubulin isotypes may use their sulfhydryl groups to scavenge ROS and protect neuronal cells against oxidative stress.
Patient Protection and Affordable Care Act Medicaid expansion and gains in health insurance coverage and access among cancer survivors
Authors: Nikpay Sayeh S. , Tebbs Margaret G. , Castellanos Emily H. 
Published: April 2018

BACKGROUNDThe Patient Protection and Affordable Care Act extends Medicaid coverage to millions of low‐income adults, including many survivors of cancer who were unable to purchase affordable health insurance coverage in the individual health insurance market.METHODSUsing data from the 2011 to 2015 Behavioral Risk Factor Surveillance System, the authors compared changes in coverage and health care access measures for low‐income cancer survivors in states that did and did not expand Medicaid.RESULTSThe study population of 17,381 individuals included adults aged 18 to 64 years, and was predominantly female, white, and unmarried. The authors found a relative reduction in the uninsured rate of 11.7 percentage points and a relative increase in the probability of having a personal physician of 5.8 percentage points. Stratifying by whether states expanded Medicaid by 2015, the authors found that relative gains in coverage and access were larger among those individuals residing in states with expanded Medicaid compared with those residing in nonexpansion states.CONCLUSIONSThe results of the current study suggest that the Patient Protection and Affordable Care Act Medicaid expansion has improved coverage and access for cancer survivors. Cancer 2018;124:2645‐52. © 2018 American Cancer Society.
Mesoporous Shell@Macroporous Core Aluminosilicates as Sustainable Nanocatalysts for Direct N‐alkylation of Amines
Authors: Sunil Sekhar Anandakumari C. , Ashokkumar Anumol Erumpukuthickal , Cygnet Choorapoikayil T. , Vidhya Lakshmi Saseendranpillai , Deepak Francis Leonard , Vinod Chathakudath P. 
Published: April 2018

AbstractAluminosilicate spheres with a macroporous core and mesoporous shell (Si/Al ratio of 11) is synthesised by a sol‐gel method utilizing cetyltrimethyl ammonium bromide (CTAB) as a structure directing agent in basic medium. The selective incorporation of aluminium in the silica matrix results in the formation of aluminosilicates with an overall acidity of 0.32 mmol/g with interconnected pores. Direct N‐alkylation reaction is a prototype of C−N bond formation reaction and meso‐ macroporous aluminosilicate is shown to catalyze this reaction with excellent yield. The catalyst is tested and found sustainable for five catalytic cycles even without any high temperature regeneration step.
Blockchain‐based fair three‐party contract signing protocol for fog computing
Authors: Huang Hui , Li Kuan‐Ching , Chen Xiaofeng 
Published: April 2018

SummaryFog computing is a new computing paradigm that can provide flexible resources and services at the edge of network. It is an extension of cloud computing and usually cooperated with cloud computing. Therefore, end users, fog nodes, and cloud servers can form a three‐layer service model in practical application. In this model, they should have an agreement on a service contract, which contains every party's rights and obligations before the beginning of the service. However, due to lack of trust, it will suffer from some fairness problems during signing a service contract. Contract signing protocol allows two or more mutual distrust entities to sign a predefined digital contract in a fair and effective way. In this paper, we propose a fair three‐party contract signing protocol based on the primitive of blockchain, which can be applied to the scenario of fog computing. Our proposed construction allows the participants to sign a contract in a fair way without the involvement of an arbitrator. Moreover, the privacy of the contract content can be preserved on the public chain. Finally, we realize the proposed protocol through the private blockchain and provide the experimental simulation that analyzes the efficiency and effectiveness.
Quantifying the impact of shutdown techniques for energy‐efficient data centers
Authors: Raïs Issam , Orgerie Anne‐Cécile , Quinson Martin , Lefèvre Laurent 
Published: April 2018

SummaryCurrent large‐scale systems, like datacenters and supercomputers, are facing an increasing electricity consumption. These infrastructures are often dimensioned according to the workload peak. However, as their consumption is not power‐proportional when the workload is low, the power consumption is still high. Shutdown techniques have been developed to adapt the number of switched‐on servers to the actual workload. However, datacenter operators are reluctant to adopt such approaches because of their potential impact on reactivity and hardware failures, and their energy gain is often largely misjudged. In this article, we evaluate the potential gain of shutdown techniques by taking into account shutdown and boot up costs in time and energy. This evaluation is made on recent server architectures and future energy‐aware architectures. Our simulations exploit real traces collected on production infrastructures under various machine configurations with several shutdown policies, with and without workload prediction. We study the impact of future's knowledge for saving energy with such policies. Finally, we examine the energy benefits brought by suspend‐to‐disk and suspend‐to‐RAM techniques, and we study the impact of shutdown techniques on the energy consumption of prospective hardware with heterogeneous processors (big‐medium‐little paradigm).