bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Evidence of Chemical Components in the Bonding of Helium and Neon with Neutral Molecules
Authors: Cappelletti David , Bartocci Alessio , Grandinetti Felice , Falcinelli Stefano , Belpassi Leonardo , Tarantelli Francesco , Pirani Fernando 
Published: March 2015

AbstractThe complexes of helium and neon with gaseous neutral molecules are generally perceived to be van der Waals adducts held together by physical (non‐covalent) forces, owing to the combination of size (exchange) repulsion with dispersion/induction attraction. Molecular beam experiments confirm that this is the case for He–CF4, Ne–CF4 adducts, but revealed that the interaction of He and Ne with CCl4 features an appreciable contribution of chemical components that arise from the anisotropy of the electron density of CCl4 that enhances a charge transfer from Ng (Ng=He, Ne). These findings furnish a novel assay of the bonding capabilities of helium and neon, and invite to revisit the neutral complexes of these elements as systems of chemical relevance. The CCl4–Ng are also peculiar examples of halogen bonds, a group of interactions of major current concern. Finally, this investigation is a prelude to the development of semi‐empirical models for force fields aimed to the unified description of static and dynamical properties of systems of comparable or higher complexity.
Lewis Acid Behavior of SF4: Synthesis, Characterization, and Computational Study of Adducts of SF4with Pyridine and Pyridine Derivatives
Authors: Chaudhary Praveen , Goettel James T. , Mercier Hélène P. A. , Sowlati‐Hashjin Shahin , Hazendonk Paul , Gerken Michael 
Published: March 2015

AbstractSulfur tetrafluoride was shown to act as a Lewis acid towards organic nitrogen bases, such as pyridine, 2,6‐dimethylpyridine, 4‐methylpyridine, and 4‐dimethylaminopyridine. The SF4⋅NC5H5, SF4⋅2,6‐NC5H3(CH3)2, SF4⋅4‐NC5H4(CH3), and SF4⋅4‐NC5H4N(CH3)2adducts can be isolated as solids that are stable below −45 °C. The Lewis acid–base adducts were characterized by low‐temperature Raman spectroscopy and the vibrational bands were fully assigned with the aid of density functional theory (DFT) calculations. The electronic structures obtained from the DFT calculations were analyzed by the quantum theory of atoms in molecules (QTAIM). The crystal structures of SF4⋅NC5H5, SF4⋅4‐NC5H4(CH3), and SF4⋅4‐NC5H4N(CH3)2revealed weak SN dative bonds with nitrogen coordinating in the equatorial position of SF4. Based on the QTAIM analysis, the non‐bonded valence shell charge concentration on sulfur, which represents the lone pair, is only slightly distorted by the weak dative SN bond. No evidence for adducts between quinoline or isoquinoline with SF4was found by low‐temperature Raman spectroscopy.
Practical Synthesis of [n]Cycloparaphenylenes (n=5, 7–12) by H2SnCl4‐Mediated Aromatization of 1,4‐Dihydroxycyclo‐2,5‐diene Precursors
Authors: Patel Vijay Kumar , Kayahara Eiichi , Yamago Shigeru 
Published: March 2015

AbstractCyclic precursors of cycloparaphenylenes (CPPs) containing 1,4‐dihydroxy‐2,5‐cyclohexadien‐1,4‐diyl units are prepared by modifying a synthetic method developed by Jasti and co‐workers for the synthesis of corresponding 1,4‐dimethoxy derivatives. Reductive aromatization of the diyl moieties by SnCl2/2 HCl takes place under mild conditions and affords the CPPs in good yields, incorporating 5 or 7–12 phenylene units. Highly strained [5]CPP is synthesized in greater than 0.3 g scale. 119Sn NMR spectroscopy clarifies the in situ formation of an ate complex, H2SnCl4, upon mixing a 2:1 ratio of HCl and SnCl2, which serves as a highly active reducing agent under nearly neutral conditions. When more than 2 equivalents of HCl, in relation to SnCl2, are used, acid‐catalyzed decomposition of the CPP precursors takes place. The stoichiometry of HCl and SnCl2 is critical in achieving the desired aromatization reaction of highly strained CPP precursors.
Importance of Outer‐Sphere and Aggregation Phenomena in the Relaxation Properties of Phosphonated Gadolinium Complexes with Potential Applications as MRI Contrast Agents
Authors: Elhabiri Mourad , Abada Sabah , Sy Mohamadou , Nonat Aline , Choquet Philippe , Esteban‐Gómez David , Cassino Claudio , Platas‐Iglesias Carlos , Botta Mauro , Charbonnière Loïc J. 
Published: March 2015

AbstractA series composed of a tetra‐, a tris‐ and a bisphosphonated ligand based on a pyridine scaffold (L4, L3 and L2, respectively) was studied within the frame of lanthanide (Ln) coordination. The stability constants of the complexes formed with lanthanide cations (Ln=La, Nd, Eu, Gd, Tb, Er and Lu) were determined by potentiometry in aqueous solutions (25.0 °C, 0.1 M NaClO4), showing that the tetraphosphonated complexes are among the most stable LnIII complexes reported in the literature. The complexation of L4 was further studied by different titration experiments using mass spectrometry and various spectroscopic techniques including UV/Vis absorption, and steady state and time‐resolved luminescence (Ln=Eu and Tb). Titration experiments confirmed the formation of highly stable [LnL4] complexes. 31P NMR experiments of the LuL4 complex revealed an intramolecular interconversion process which was studied at different temperatures and was rationalized by DFT modelling. The relaxivity properties of the GdIII complexes were studied by recording their 1H NMRD profiles at various temperatures, by temperature dependent 17O NMR experiments (GdL4) and by pH dependent relaxivity measurements at 0.47 T (GdL3 and GdL2). In addition to the high relaxivity values observed for all complexes, the results showed an important second‐sphere contribution to relaxivity and pH dependent variations associated with the formation of aggregates for GdL2 and GdL3. Finally, intravenous injection of GdL4 to a mouse was followed by dynamic MRI imaging at 1.5 T, which showed that the complex can be immediately found in the blood stream and rapidly eliminated through the liver and in large part through the kidneys.
Coordination Chemistry of N‐Heterocyclic Nitrenium‐Based Ligands
Authors: Tulchinsky Yuri , Kozuch Sebastian , Saha Prasenjit , Mauda Assaf , Nisnevich Gennady , Botoshansky Mark , Shimon Linda J. W. , Gandelman Mark 
Published: March 2015

AbstractInvited for the cover of this issue is the group of Mark Gandelman at Technion, The Israel Institute of Technology. The image depicts how a wide variety of transition metals in various oxidation states can be “picked up” by tridentate nitrenium ligands to form complexes with potentially interesting properties (cover design by Igor Armiach). Read the full text of the article at 10.1002/chem.201405526.
Screening Approach for Chiral Separation of β‐Aminoketones by HPLC on Various Polysaccharide‐Based Chiral Stationary Phases
Authors: Addadi Khadidja , Sekkoum Khaled , Belboukhari Nasser , Cheriti Abdelkrim , Aboul‐Enein Hassan Y. 
Published: March 2015

AbstractNine β‐aminoketones were synthesized via Mannich reaction when benzaldehyde was condensed with some primary amines and acetophenone. The purified compounds were identified by using spectroscopic methods. The enantiomeric separation of these derivatives was carried out by high‐performance liquid chromatography (HPLC) using several coated and immobilized polysaccharide stationary phases, namely, Chiralcel® OD‐H, Chiralcel® OD, Chiralcel® OJ, Chiralpak® AD, Chiralpak® IA, and Chiralpak® IB using different mobile phases composed of n‐hexane and alcohol mixed in various ratios or pure ethanol or isopropanol. The retention behavior and selectivity of these chiral stationary phases were examined in isocratic normal phase mode. The results indicate that cellulose derivatives have higher enantioselectivity than amylose derivatives for the separation of racemic β‐amino ketones. Chirality 27:332–338, 2015. © 2015 Wiley Periodicals, Inc.
Midterm Follow‐up After Retrievable Inferior Vena Cava Filter Placement in Venous Thromboembolism Patients With or Without Malignancy
Authors: Myojo Masahiro , Takahashi Masao , Tanaka Tomofumi , Higashikuni Yasutomi , Kiyosue Arihiro , Ando Jiro , Fujita Hideo , Komuro Issei , Hirata Yasunobu 
Published: March 2015

AbstractBackgroundA clear indication and strategy for placement of retrievable inferior vena cava filters (IVCFs) have not been established. This study was designed to evaluate the efficacy and disadvantages of the retrievable IVCF use particularly in venous thromboembolism (VTE) patients with malignancy.HypothesisRetrievable IVCFs might be safe and useful in VTE patients with malignancy.MethodsThe study population consisted of 56 consecutive patients undergoing IVCF placement at our institution from January 1, 2008 to December 31, 2011. Prognostic data were retrospectively reviewed in April 2013.ResultsMean follow‐up period was 584.6 (range, 1–1857) days. Twenty‐six of the 56 patients had a malignancy. In 16 of the 30 patients without malignancy, the filter was retrieved, whereas the other 14 patients eventually received permanent implantation. There was no significant difference in the survival rate between the retrieval group and the nonretrieval group in the nonmalignancy patients (1‐year survival rates, 94% vs 85%). In patients with malignancy, the nonretrieval group showed a significantly lower survival rate (P < 0.01). The 1‐year and 2‐year survival rates were 100% vs 46% and 100% vs 18%, respectively. There was no medical record of pulmonary thromboembolism occurrence or recurrence. All deaths in the patients with malignancy were malignancy related. In 4 of 5 malignancy patients who could undergo tumor resection surgery, adequate thrombus regression enabled us to retrieve the IVCF after surgery.ConclusionsPermanent use of a retrievable IVCF is relatively safe in short‐ or midterm follow‐up regardless of malignancy status. Retrievable filter use might be reasonable in malignancy patients.
Linear Alkane CC Bond Chemistry Mediated by Metal Surfaces
Authors: Cai Zeying , Liu Meizhuang , She Limin , Li Xiaoli , Lee Jason , Yao Dao‐Xin , Zhang Haiming , Chi Lifeng , Fuchs Harald , Zhong Dingyong 
Published: March 2015

AbstractLinear alkanes undergo different CC bond chemistry (coupling or dissociation) thermally activated on anisotropic metal surfaces depending on the choice of the substrate material. Owing to the one‐dimensional geometrical constraint, selective dehydrogenation and CC coupling (polymerization) of linear alkanes take place on Au(110) surfaces with missing‐row reconstruction. However, the case is dramatically different on Pt(110) surfaces, which exhibit similar reconstruction as Au(110). Instead of dehydrogenative polymerization, alkanes tend to dehydrogenative pyrolysis, resulting in hydrocarbon fragments. Density functional theory calculations reveal that dehydrogenation of alkanes on Au(110) surfaces is an endothermic process, but further CC coupling between alkyl intermediates is exothermic. On the contrary, due to the much stronger CPt bonds, dehydrogenation on Pt(110) surfaces is energetically favorable, resulting in multiple hydrogen loss followed by CC bond dissociation.
Photocatalytic Direct Conversion of Ethanol to 1,1‐ Diethoxyethane over Noble‐Metal‐Loaded TiO2 Nanotubes and Nanorods
Authors: Zhang Hongxia , Wu Yupeng , Li Li , Zhu Zhenping 
Published: March 2015

AbstractAs one of the most important biomass platform molecules, ethanol needs to have its product chain chemically extended to meet future demands in renewable fuels and chemicals. Additionally, chemical conversion of ethanol under mild and green conditions is still a major challenge. In this work, ethanol is directly converted into 1,1‐diethoxyethane (DEE) and H2 under mild photocatalytic conditions over platinum‐loaded TiO2 nanotubes and nanorods. The reaction follows a tandem dehydrogenation–acetalization mechanism, in which ethanol is first dehydrogenated into acetaldehyde and H+ ion by photogenerated holes, and then acetalization between acetaldehyde and ethanol proceeds through promotion by H+ ions formed in real time. Excess H+ ions are simultaneously reduced into H2 by photogenerated electrons. This photocatalytic process has a very high reaction rate over nanosized tubular and rod‐like TiO2 photocatalysts, reaching 157.7 mmol g−1 h−1 in relatively low photocatalyst feeding. More importantly, the reaction is highly selective, with a nearly stoichiometric conversion of reacted ethanol into DEE. This photocatalytic dehydrogenation CO coupling of ethanol is a new green approach to the direct efficient conversion of ethanol into DEE and provides a promising channel for sustainable bioethanol applications.
Analysis and Prediction of Stacking Sequences in Intercalated Lamellar Vanadium Phosphates
Authors: Gautier Romain , Fourré Yoann , Furet Eric , Gautier Régis , Le Fur Eric 
Published: March 2015

AbstractAn approach is presented that enables the analysis and prediction of stacking sequences in intercalated lamellar vanadium phosphates. A comparison of previously reported vanadium phosphates reveals two modes of intercalation: (i) 3d transition metal ions intercalated between VOPO4 layers and (ii) alkali/alkaline earth metal ions between VOPO4·H2O layers. Both intercalations were investigated using DFT calculations in order to understand the relative shifts of the vanadium phosphate layers. These calculations in addition to an analysis of the stacking sequences in previously reported materials enable the prediction of the crystal structures of Mx(VOPO4)·yH2O (M = Cs+, Cd2+ and Sn2+). Experimental realization and structural determination of Cd(VOPO4)2·4H2O by single‐crystal X‐ray diffraction confirmed the predicted stacking sequences.
ITO‐ITO Dual‐Plate Microgap Electrodes: E and EC′ Generator‐Collector Processes
Authors: Gross Andrew J. , Marken Frank 
Published: March 2015

AbstractTin‐doped indium oxide electrodes are fabricated and employed in a dual‐plate microtrench geometry with the inter‐electrode gap controlling the mass transport conditions in generator‐collector mode. Electrodes are fabricated with 2–50 µm gap sizes and variable trench depths by controlling assembly parameters. Non‐ideal behaviour is observed for three aqueous redox systems: Ru(bpy)${{{3+/2+\hfill \atop 3\hfill}}}$, 1,1′‐ferrocenedimethanol and Ru(NH3)${{{3+/2+\hfill \atop 6\hfill}}}$. Under fast mass transport conditions, the former two systems exhibit slower oxidation features. For Ru(NH3)${{{3+/2+\hfill \atop 6\hfill}}}$, non‐steady‐state behaviour is observed due to irreversible (ECirrev′) consumption of oxygen in the microtrench. A mechanism leading to hydrogen peroxide formation via superoxide in Ru(NH3)${{{2+\hfill \atop 6\hfill}}}$ solution is proposed. Under optimised conditions all three redox systems provide reliable trench depth calibration information.
Electrochemical Sensor Based on Carbon Nanotubes for the Simultaneous Detection of Phenolic Pollutants
Authors: Govindhan Maduraiveeran , Lafleur Todd , Adhikari Bal‐Ram , Chen Aicheng 
Published: March 2015

AbstractA mediator‐free electrochemical sensing platform was designed by utilizing single‐walled carbon nanotube (SWCNT) modified glassy carbon (GC) electrodes for the electrocatalytic oxidation of phenolic compounds. The proposed sensing platform permits the sensitive simultaneous detection of catechol, p‐cresol and p‐nitrophenol with the lowest detection limits of 2.3, 3.7 and 7.7 nM, and high sensitivities of 135.08, 94.90 and 110.38 µA/µM, respectively. The non‐enzymatic electrochemical sensor designed in this study also exhibited high stablility and reproducible as well as rapid response, providing new opportunities for the development of sensing devices in the detection of multiple phenolic compounds simultaneously for practical environmental applications.
Patient‐Satisfaction Surveys on a Scale of 0 to 10: Improving Health Care, or Leading It Astray?
Authors: Junewicz Alexandra , Youngner Stuart J. 
Published: March 2015

AbstractThe current institutional focus on patient satisfaction and on surveys designed to assess this could eventually compromise the quality of health care while simultaneously raising its cost. We begin this paper with an overview of the concept of patient satisfaction, which remains poorly and variously defined. Next, we trace the evolution of patient‐satisfaction surveys, including both their useful and problematic aspects. We then describe the effects of these surveys, the most troubling of which may be their influence on the behavior of health professionals. The pursuit of high patient‐satisfaction scores may actually lead health professionals and institutions to practice bad medicine by honoring patient requests for unnecessary and even harmful treatments. Patient satisfaction is important, especially when it is a response to being treated with dignity and respect, and patient‐satisfaction surveys have a valuable place in evaluating health care. Nonetheless, some uses and consequences of these surveys may actively mislead health care.Our critique of patient‐satisfaction surveys takes into consideration three different ways patients may be “satisfied.” First is the provision of medically necessary care that actually improves their outcomes. The second concerns interventions that patients or families want but that are medically unnecessary and may negatively affect health outcomes. The third category—comprising factors that are less likely to affect health outcomes but may certainly contribute to a sense of dignity and well‐being—includes “humanistic” aspects of health care, such as good communication and treating patients with respect, as well as peripheral aspects, such as convenient parking and designer hospital gowns. These distinctions are important as we explore patient satisfaction and its implications.
Iminosugars as Immunomodulating Agents: Synthesis and Biological Activities of 1‐Deoxynojirimycin and Related Compounds
Authors: Li Qin , Ye Xin‐Shan 
Published: March 2015

AbstractIminosugars are an extremely interesting and versatile class of compounds and have many potential therapeutic applications. However, the use of iminosugar derivatives as immunomodulating agents is an area that is less explored. This review describes recent advances in the field of iminosugars as immunomodulating agents with a particular emphasis on 1‐deoxynojirimycin analogues and related compounds. Both chemical and biological aspects concerning their preparation and/or occurrence in nature, as well as their immunomodulatory properties, are discussed.
Modelling Hospital Admission and Length of Stay by Means of Generalised Count Data Models
Authors: Herwartz Helmut , Klein Nadja , Strumann Christoph 
Published: March 2015

SummaryFor a large heterogeneous group of patients, we analyse probabilities of hospital admission and distributional properties of lengths of hospital stay conditional on individual determinants. Bayesian structured additive regression models for zero‐inflated and overdispersed count data are employed. In addition, the framework is extended towards hurdle specifications, providing an alternative approach to cover particularly large frequencies of zero quotes in count data. As a specific merit, the model class considered embeds linear and nonlinear effects of covariates on all distribution parameters. Linear effects indicate that the quantity and severity of prior illness are positively correlated with the risk of hospital admission, while medical prevention (in the form of general practice visits) and rehabilitation reduce the expected length of future hospital stays. Flexible nonlinear response patterns are diagnosed for age and an indicator of a patients' socioeconomic status. We find that social deprivation exhibits a positive impact on the risk of admission and a negative effect on the expected length of future hospital stays of admitted patients. Copyright © 2015 John Wiley & Sons, Ltd.
T‐helper cell‐mediated factors in drug‐induced liver injury
Authors: Wang Xinzhi , Zhang Luyong , Jiang Zhenzhou 
Published: March 2015

AbstractDrug‐induced liver injury (DILI) leads to a large burden on the healthcare system due to its potential morbidity and mortality. The key for predicting and preventing DILI is to understand the underlying mechanisms. Hepatic inflammation is one of the most common features of DILI. The inflammation can be attributed to the innate immune response. The adaptive immune system is also affected by the innate immune response resulting in liver damage. T‐helper cells are important regulators of acquired immunity. T‐helper cell‐mediated immune responses play pivotal roles in the pathogenesis of a variety of liver disorders. This review summarizes recent advances in the T‐helper cell‐mediated factors in DILI and potential mechanisms, which may lead to a better understanding of DILI. Copyright © 2015 John Wiley & Sons, Ltd.
Comparative toxicity of silicon dioxide, silver and iron oxide nanoparticles after repeated oral administration to rats
Authors: Yun Jun‐Won , Kim Seung‐Hyun , You Ji‐Ran , Kim Woo Ho , Jang Ja‐June , Min Seung‐Kee , Kim Hee Chan , Chung Doo Hyun , Jeong Jayoung , Kang Byeong‐Cheol , Che Jeong‐Hwan 
Published: March 2015

AbstractAlthough silicon dioxide (SiO2), silver (Ag) and iron oxide (Fe2O3) nanoparticles are widely used in diverse applications from food to biomedicine, in vivo toxicities of these nanoparticles exposed via the oral route remain highly controversial. To examine the systemic toxicity of these nanoparticles, well‐dispersed nanoparticles were orally administered to Sprague–Dawley rats daily over a 13‐week period. Based on the results of an acute toxicity and a 14‐day repeated toxicity study, 975.9, 1030.5 and 1000 mg kg–1 were selected as the highest dose of the SiO2, Ag and Fe2O3 nanoparticles, respectively, for the 13‐week repeated oral toxicity study. The SiO2 and Fe2O3 nanoparticles did not induce dose‐related changes in a number of parameters associated with the systemic toxicity up to 975.9 and 1000 mg kg–1, respectively, whereas the Ag nanoparticles resulted in increases in serum alkaline phosphatase and calcium as well as lymphocyte infiltration in liver and kidney, raising the possibility of liver and kidney toxicity induced by the Ag nanoparticles. Compared with the SiO2 and Fe2O3 nanoparticles showing no systemic distribution in all tissues tested, the Ag concentration in sampled blood and organs in the Ag nanoparticle‐treated group significantly increased with a positive and/or dose‐related trend, meaning that the systemic toxicity of the Ag nanoparticles, including liver and kidney toxicity, might be explained by extensive systemic distribution of Ag originating from the Ag nanoparticles. Our current results suggest that further study is required to identify that Ag detected outside the gastrointestinal tract were indeed a nanoparticle form or ionized form. Copyright © 2015 John Wiley & Sons, Ltd.