bluuebunny/crossref_metadata_2025_split huggingface dataset:
Degenerative mitral regurgitation predicts worse outcomes in patients undergoing transcatheter aortic valve replacement
Authors: Kindya Bryan , Ouzan Elisha , Lerakis Stamatios , Gonen Erhan , Babaliaros Vasilis , Karayel Eren , Thourani Vinod H. , Gotsman Israel , Devireddy Chandan M. , Danenberg Haim D. , Leshnower Bradley G. , Beeri Ronen , Ko Yi‐An , Gilon Dan , Ahmed Hina , Liu Chang , Lotan Chaim , Mavromatis Kreton 
Published: March 2018

AbstractObjectivesTo evaluate the role mitral regurgitation (MR) etiology and severity play in outcomes for patients undergoing transcatheter aortic valve replacement (TAVR).BackgroundMultiple prior studies have investigated the influence of MR severity on outcomes for patients undergoing TAVR. Less has been published regarding the effects of MR etiology on outcomes, including its impact on heart failure hospitalization.MethodsTwo hundred and seventy patients undergoing TAVR at 2 hospitals were enrolled. Each patient had a baseline and follow‐up (within 30 days of TAVR) echocardiogram that was analyzed. MR was graded as none, mild, moderate, or severe, as well as functional or degenerative. We compared patient outcomes, including death and heart failure hospitalization, among none‐mild MR, moderate‐severe functional MR, and moderate‐severe degenerative MR groups.ResultsTwo hundred and seventy patients underwent TAVR, reducing mean aortic valve gradients from 45 ± 15 mm Hg to 9 ± 4 mm Hg. On multivariable analysis, only patients with moderate‐severe degenerative MR had decreased survival free of death or CHF hospitalization compared to those with none‐mild MR (P = .011). Subanalysis showed patients with moderate‐severe degenerative MR were more likely to be hospitalized for heart failure at 2 years compared to those with moderate‐severe functional MR (P = .02). Patients with moderate‐severe degenerative MR were also less likely to have improvement in MR severity at follow up (P = .01).ConclusionsSpecial consideration should be given to patients with moderate‐severe degenerative MR undergoing TAVR. As transcatheter approaches for mitral valve repair and replacement continue to evolve, moderate‐severe degenerative MR patients may benefit from consideration of double valve intervention.
Patent foramen ovale (PFO) closure versus medical therapy for prevention of recurrent stroke in patients with prior cryptogenic stroke: A systematic review and meta‐analysis of randomized controlled trials
Authors: Akobeng Anthony K. , Abdelgadir Ibtihal , Boudjemline Younes , Hijazi Ziyad M. 
Published: March 2018

AbstractObjectivesWe performed a systematic review and meta‐analysis of randomized controlled trials to assess the effect of closure of a patent foramen ovale (PFO) compared with medical therapy for the prevention of stroke in patients with prior cryptogenic stroke.BackgroundThe role of PFO closure in reducing risk of stroke in patients with prior cryptogenic stroke has been controversial.MethodsWe searched PubMed, Embase, CINAHL, and CENTRAL for randomized trials investigating PFO closure versus medical therapy. We assessed trial bias and the quality of evidence for main outcomes was rated using GRADE. The primary outcome of interest was the occurrence of stroke. Estimates of effect were pooled with a random‐effects model. This study is registered with PROSPERO (CRD42017081579).ResultsWe included five trials, comprising data for 3,440 adults randomized to receive PFO closure (n = 1,829) or medical therapy (n = 1,611). Mean follow‐up ranged from 2 years to 5.4 years across the trials. Patients treated with PFO closure had a lower risk of stroke (RR 0.39, 95% CI 0.18–0.88, I2 = 57%, P = 0.02) compared with those treated with medical therapy. Subgroup analyses showed that the beneficial effect of PFO closure on a composite outcome of cerebrovascular events is more pronounced in patients with a large PFO shunt (RR 0.25, 95% CI 0.12–0.54, I2 = 0%, P = 0.0004), male patients (RR 0.34, 95% CI 0.15–0.75, I2 = 36%, P = 0.07), and those aged ≤45 years (RR 0.35, 95% CI 0.15–0.79, I2 = 0%, P = 0.01).ConclusionsPFO closure reduced risk of stroke compared with medical therapy. PFO closure is a therapeutic option that should be offered to adults with cryptogenic stroke.
Reduction of catheter kinks and knots via radial approach
Authors: Ben‐Dor Itsik , Rogers Toby , Satler Lowell F. , Waksman Ron 
Published: March 2018

AbstractCoronary angiography and percutaneous coronary intervention using the radial approach are becoming more frequent. Pronounced guide catheter manipulation in cases with tortuous access routes may lead to severe catheter kinking or knotting. The purpose of this review article is to present several techniques to resolve radial access catheter knots and kinks. First, simple maneuvers such as gentle traction, rotation, and guidewire advancement can often resolve minor kinking; however, complex loops and kinks are often not reversible with these simple maneuvers. Second, fixing the distal catheter tip using external compression, encasing the knot with a larger sheath, or untwisting the knot with hydraulic pressure can be useful. Finally, internal fixation by grasping the kinked catheter with a snare introduced via the femoral artery allows both ends of the catheter to be rotated in opposite directions to untwist the catheter for safe removal.
Stepwise management of hepatocellular carcinoma associated with Abernethy syndrome
Authors: Christou Niki , Dib Nabil , Chuffart Etienne , Taibi Abdelkader , Durand‐Fontanier Sylvaine , Valleix Denis , Mathonnet Muriel 
Published: March 2018

Key Clinical MessagePatients with congenital agenesis of the portal vein may develop hepatocellular tumors due to enhanced arterial blood flow. These tumors may be benign (FNH, adenomas) or malignant (hepatoblastoma, HCC). Liver resection can be proposed, and preoperative arterial embolization may decrease blood loss during surgery. Liver transplantation with PV reconstruction is also an option.
Palladium‐Catalyzed C2−H Arylation of Unprotected (N−H)‐Indoles “On Water” Using Primary Diamantyl Phosphine Oxides as a Class of Primary Phosphine Oxide Ligands
Authors: Moncea Oana , Poinsot Didier , Fokin Andrey A. , Schreiner Peter R. , Hierso Jean‐Cyrille 
Published: March 2018

AbstractWe present the Pd‐catalyzed arylation of (N−H)‐indoles with functionalized haloarenes “on water” using hitherto untested primary diamantyl phosphine oxides (PPO) as ligands. Remarkable C2−H arylation selectivity was achieved by employing functionalized iodoarenes and N‐unprotected indoles. We provide evidence that the in situ generated oxide of (9‐hydroxydiamant‐4‐yl)phosphine L1 is key for the reaction efficiency by comparing a set of diamantane‐based compounds structurally related to L1. Our results demonstrate the power of the new PPO ligands for the C−H functionalization of unprotected (N−H)‐heterocycles.
Oxa‐Michael Addition to α,β‐Unsaturated Nitriles: An Expedient Route to γ‐Amino Alcohols and Derivatives
Authors: Guo Beibei , Zijlstra Douwe S. , de Vries Johannes G. , Otten Edwin 
Published: March 2018

AbstractWater addition to α,β‐unsaturated nitriles would give facile access to the β‐hydroxy‐nitriles, which in turn can be hydrogenated to the γ‐amino alcohols. We have previously shown that alcohols readily add in 1,4‐fashion to these substrates using Milstein's Ru(PNN) pincer complex as catalyst. However, attempted water addition to α,β‐unsaturated nitriles gave the 3‐hydroxynitriles in mediocre yields. On the other hand, addition of benzyl alcohol proceeded in excellent yields for a variety of β‐substituted unsaturated nitriles. Subsequent treatment of the benzyl alcohol addition products with TMSCl/FeCl3 resulted in the formation of 3‐hydroxy‐alkylnitriles. The 3‐benzyloxy‐alkylnitriles obtained from oxa‐Michael addition also could be hydrogenated directly in the presence of acid to give the amino alcohols as their HCl salts in excellent yields. Hydrogenation under neutral conditions gave a mixture of the secondary and tertiary amines. Hydrogenation in the presence of base and Boc‐anhydride gave the orthogonally bis‐protected amino alcohols, in which the benzyl ether can subsequently be cleaved to yield Boc‐protected amino alcohols. Thus, a variety of molecular scaffolds with a 1,3‐relationship between O‐ and N‐functional group is accessible starting from oxa‐Michael addition of benzyl alcohol to α,β‐unsaturated nitriles.
Hierarchical MnO2 Located on Carbon Nanotubes for Enhanced Electrochemical Performance
Authors: Li Shaohui , Gao Lin , Wang Lichuan , Wang Mingkui , Shen Yan 
Published: March 2018

AbstractAbstract: Herein, we assembled an asymmetric supercapacitor (ASC) with high energy and power density based on porous MnO2/nitrogen‐doped carbon nanotubes (MnO2/NCNTs) in the positive electrode and chemical activated of nitrogen‐doped carbon nanotubes (ANCNTs) in the negative electrode. The ANCNTs//MnO2/NCNTs ASC device operates reversibly at a high voltage of 2.0 V in 1.0 M Na2SO4 and exhibits a high energy density of 37.2 Wh kg−1, which can be included in the top category of supercapacitors. More importantly, the supercapacitor exhibits impressive rate capability (high power density of 15100 W kg−1 at an energy density of 12.8 Wh kg−1) and exceptional cycling stability with 95.2 % capacitance retention after 3000 cycles. These attractive results indicate the potential for efficient energy storage devices.
Reversible Delithiation of Disordered Rock Salt LiVO2
Authors: Baur Christian , Chable Johann , Klein Franziska , Chakravadhanula Venkata Sai Kiran , Fichtner Maximilian 
Published: March 2018

AbstractA rigid crystal lattice, in which cations occupy specific positions, is generally regarded as a critical requirement to enable Li+ diffusion in the bulk of conventional cathode materials, whereas disorder is generally considered as detrimental. Herein, we demonstrate that facile and reversible insertion and extraction of Li+ is possible with LiVO2, a new cation‐disordered rock salt compound (space group: Fm
m), which is, to the best of our knowledge, described for the first time. This new polymorph of LiVO2 is synthesized by mechanical alloying. Rietveld refinements of the X‐ray diffractions patterns and SAED (selected‐area electron diffraction) patterns attested the formation of the disordered LiVO2 rock salt phase. Galvanostatic cycling experiments were employed to characterize the electrochemical performance of the material, demonstrating that reversible cycling over 100 cycles with a discharge capacity around 100 mAh g−1 is possible.
Elucidating the Structure–Reactivity Correlations of Phenothiazine‐Based Fluorescent Probes toward ClO−
Authors: Wang Shichao , Zhang Boyu , Wang Wenjing , Feng Gang , Yuan Daqiang , Zhang Xuanjun 
Published: March 2018

AbstractIn this work, with the aim of developing effective molecular probes and investigating the structure–reactivity correlation, a short series of phenothiazine‐based fluorescent probes are designed for the detection of ClO− with differing electron push‐pull groups. Sensing experiment results and single‐crystal X‐ray analysis with the aid of time‐dependent DFT (TD‐DFT) calculations reveal that substituting groups with increasing electron‐withdrawing ability can increase the dihedral angle of the phenothiazine moiety and reduce the gap energy of the probes, leading to enhanced reactivity toward ClO−. Both PT1 and PT2 show two‐color switching upon detection of ClO−. PT1, with the strong electron‐donating group thiophene, shows a fluorescence color switch from salmon to blue. PT2, with a medium electron‐donating/accepting group benzothiazole, shows a fluorescence color switch from red to green. However, both PT1 and PT2 show almost no response to ONOO−. Through the introduction of strong electron‐withdrawing ketone combined with a cyano group, PT3 shows a cyan emission upon detection of ClO− and weak red emission upon detection of ONOO−. HRMS and 1H NMR results confirm that PT1 and PT2 have the same sensing mode, in which the divalent sulfur of phenothiazine can be oxidized to sulfoxide by ClO−. Upon reaction with ClO−, PT3 experiences two‐step reactions. It is first oxidized into the sulfone structure by ClO−, and then transformed into sulfoxide phenothiazine aldehyde. Upon encountering ONOO−, PT3 changes into an aldehyde structure and some nonfluorescent byproducts. Owing to their special selectivity and high sensitivity, PT1 and PT2 are applied to image the endogenous ClO− in macrophage cells and zebrafish larvae. This study is expected to provide useful guidelines for probe design for various applications.
A Systematic Protocol for Benchmarking Guest–Host Interactions by First‐Principles Computations: Capturing CO2 in Clathrate Hydrates
Authors: Arismendi‐Arrieta Daniel J. , Valdés Álvaro , Prosmiti Rita 
Published: March 2018

AbstractClathrate hydrates of CO2 have been proposed as potential molecular materials in tackling important environmental problems related to greenhouse gases capture and storage. Despite the increasing interest in such hydrates and their technological applications, a molecular‐level understanding of their formation and properties is still far from complete. Modeling interactions is a challenging and computationally demanding task, essential to reliably determine molecular properties. First‐principles calculations for the CO2 guest in all sI, sII, and sH clathrate cages were performed, and the nature of the guest–host interactions, dominated by both hydrogen‐bond and van der Waals forces, was systematically investigated. Different families of density functionals, as well as pairwise CO2@H2O model potentials versus wavefunction‐based quantum approaches were studied for CO2 clathrate‐like systems. Benchmark energies for new distance‐dependent datasets, consisting of potential energy curves sampling representative configurations of the systems at the repulsive, near‐equilibrium, and asymptotic/long‐range regions of the full‐dimensional surface, were generated, and a general protocol was proposed to assess the accuracy of such conventional and modern approaches at minimum and non‐minimum orientations. Our results show that dispersion interactions are important in the guest–host stabilization energies of such clathrate cages, and the encapsulation of the CO2 into guest‐free clathrate cages is always energetically favorable. In addition, the orientation of CO2 inside each cage was explored, and the ability of current promising approaches to accurately describe non‐covalent CO2@H2O guest–host interactions in sI, sII, and sH clathrates was discussed, providing information for their applicability to future multiscale computer simulations.
Structural Analysis of a GalNAc‐T2 Mutant Reveals an Induced‐Fit Catalytic Mechanism for GalNAc‐Ts
Authors: de las Rivas Matilde , Coelho Helena , Diniz Ana , Lira‐Navarrete Erandi , Compañón Ismael , Jiménez‐Barbero Jesús , Schjoldager Katrine T. , Bennett Eric P. , Vakhrushev Sergey Y. , Clausen Henrik , Corzana Francisco , Marcelo Filipa , Hurtado‐Guerrero Ramon 
Published: March 2018

AbstractThe family of polypeptide N‐acetylgalactosamine (GalNAc) transferases (GalNAc‐Ts) orchestrates the initiating step of mucin‐type protein O‐glycosylation by transfer of GalNAc moieties to serine and threonine residues in proteins. Deficiencies and dysregulation of GalNAc‐T isoenzymes are related to different diseases. Recently, it has been demonstrated that an inactive GalNAc‐T2 mutant (F104S), which is not located at the active site, induces low levels of high‐density lipoprotein cholesterol (HDL‐C) in humans. Herein, the molecular basis for F104S mutant inactivation has been deciphered. Saturation transfer difference NMR spectroscopy experiments demonstrate that the mutation induces loss of binding to peptide substrates. Analysis of the crystal structure of the F104S mutant bound to UDP‐GalNAc (UDP=uridine diphosphate), combined with molecular dynamics (MD) simulations, has revealed that the flexible loop is disordered and displays larger conformational changes in the mutant enzyme than that in the wild‐type (WT) enzyme. 19F NMR spectroscopy experiments reveal that the WT enzyme only reaches the active state in the presence of UDP‐GalNAc, which provides compelling evidence that GalNAc‐T2 adopts a UDP‐GalNAc‐dependent induced‐fit mechanism. The F104S mutation precludes the enzyme from achieving the active conformation and concomitantly binding peptide substrates. This study provides new insights into the catalytic mechanism of the large family of GalNAc‐Ts and how these enzymes orchestrate protein O‐glycosylation.
Directional Self‐Sorting with Cucurbit[8]uril Controlled by Allosteric π–π and Metal–Metal Interactions
Authors: Kotturi Kondalarao , Masson Eric 
Published: March 2018

AbstractTo maximize Coulombic interactions, cucurbit[8]uril (CB[8]) typically forms ternary complexes that distribute the positive charges of the pair of guests (if any) over both carbonylated portals of the macrocycle. We present here the first exception to this recognition pattern. Platinum(II) acetylides flanked by 4′‐substituted terpyridyl ligands (tpy) form 2:1 complexes with CB[8] in an exclusively stacked head‐to‐head orientation in a water/acetonitrile mixture. The host encapsulates the pair of tpy substituents, and both positive Pt centers sit on top of each other at the same CB[8] rim, leaving the other rim free of any interaction with the guests. This dramatic charge imbalance between the CB[8] rims would be electrostatically penalizing, were it not for allosteric π–π interactions between the stacked tpy ligands, and possible metal‐metal interactions between both Pt centers. When both tpy and acetylides are substituted with aryl units, the metal‐ligand complexes form 2:2 assemblies with CB[8] in aqueous medium, and the directionality of the assembly (head‐to‐head or head‐to‐tail) can be controlled, both kinetically and thermodynamically.
Synthesis and Bioactivity of Polymer‐Based Synthetic Mimics of Antimicrobial Peptides (SMAMPs) Made from Asymmetrically Disubstituted Itaconates
Authors: Boschert David , Schneider‐Chaabane Alexandra , Himmelsbach Andreas , Eickenscheidt Alice , Lienkamp Karen 
Published: March 2018

AbstractA series of asymmetrically disubstituted diitaconate monomers is presented. Starting from itaconic anhydride, functional groups could be placed selectively at the two nonequivalent carbonyl groups. By using 2D NMR spectroscopy, it was shown that the first functionalization step occurred at the carbonyl group in the β position to the double bond. These monomers were copolymerized with N,N‐dimethylacrylamide (DMAA) to yield polymer‐based synthetic mimics of antimicrobial peptides (SMAMPs). They were obtained by free radical polymerization, a metal‐free process, and still maintained facial amphiphilicity at the repeat unit level. This eliminates the need for laborious metal removal and is advantageous from a regulatory and product safety perspective. The poly(diitaconate‐co‐DMAA) copolymers obtained were statistical to alternating, and the monomer feed ratio roughly matched that of the repeat unit content of the copolymers. Investigations of varied R group hydrophobicity, repeat unit ratio, and molecular mass on antimicrobial activity against Escherichia coli and on compatibility with human keratinocytes showed that the polymers with the longest R groups and lowest DMAA content were the most antimicrobial and hemolytic. This is in agreement with the biological activity of previously reported SMAMPs. Thus, the design concept of facial amphiphilicity has successfully been transferred, but the selectivity of these polymers for bacteria over mammalian cells still needs to be optimized.
How psychic distance and opportunity perceptions affect entrepreneurial firm internationalization
Authors: Bhowmick Sanjay 
Published: March 2018

AbstractPsychic distance, now established as an individual perceptual construct, is so far a partial explanation of internationalization processes of entrepreneurial firms. Opportunity in foreign markets, although considered important, has hitherto been an assumption rather than explored as an explanatory factor in internationalization theories. Through qualitative data from technology entrepreneurs from New Zealand this study considers opportunity, like psychic distance, as an individual perceptual construct and posits that a combination of opportunity and psychic distance perceptions better explains entrepreneurial internationalization action/intention decisions. The explicit combination proposed is “opportunity‐distance quotient” and signifies a shift from psychic distance obstacles based explanations to an opportunity‐psychic distance interaction based exploration of entrepreneurial internationalization. Limitations of the study and further research are discussed. Copyright © 2018 ASAC. Published by John Wiley & Sons, Ltd.
Quantification of near‐wall hemodynamic risk factors in large‐scale cerebral arterial trees
Authors: Ghaffari Mahsa , Alaraj Ali , Du Xinjian , Zhou Xiaohong Joe , Charbel Fady T. , Linninger Andreas A. 
Published: March 2018

AbstractDetailed hemodynamic analysis of blood flow in pathological segments close to aneurysm and stenosis has provided physicians with invaluable information about the local flow patterns leading to vascular disease. However, these diseases have both local and global effects on the circulation of the blood within the cerebral tree. The aim of this paper is to demonstrate the importance of extending subject‐specific hemodynamic simulations to the entire cerebral arterial tree with hundreds of bifurcations and vessels, as well as evaluate hemodynamic risk factors and waveform shape characteristics throughout the cerebral arterial trees. Angioarchitecture and in vivo blood flow measurement were acquired from healthy subjects and in cases with symptomatic intracranial aneurysm and stenosis. A global map of cerebral arterial blood flow distribution revealed regions of low to high hemodynamic risk that may significantly contribute to the development of intracranial aneurysms or atherosclerosis. Comparison of pre‐intervention and post‐intervention of pathological cases further shows large angular phase shift (~33.8°), and an augmentation of the peak‐diastolic velocity. Hemodynamic indexes of waveform analysis revealed on average a 16.35% reduction in the pulsatility index after treatment from lesion site to downstream distal vessels. The lesion regions not only affect blood flow streamlines of the proximal sites but also generate pulse wave shift and disturbed flow in downstream vessels. This network effect necessitates the use of large‐scale simulation to visualize both local and global effects of pathological lesions.