bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanistic Investigation of the Ruthenium–N‐Heterocyclic‐Carbene‐Catalyzed Amidation of Amines with Alcohols
Authors: Makarov Ilya S. , Fristrup Peter , Madsen Robert 
Published: October 2012

AbstractThe mechanism of the ruthenium–N‐heterocyclic‐carbene‐catalyzed formation of amides from alcohols and amines was investigated by experimental techniques (Hammett studies, kinetic isotope effects) and by a computational study with dispersion‐corrected density functional theory (DFT/M06). The Hammett study indicated that a small positive charge builds‐up at the benzylic position in the transition state of the turnover‐limiting step. The kinetic isotope effect was determined to be 2.29(±0.15), which suggests that the breakage of the CH bond is not the rate‐limiting step, but that it is one of several slow steps in the catalytic cycle. Rapid scrambling of hydrogen and deuterium at the α position of the alcohol was observed with deuterium‐labeled substrates, which implies that the catalytically active species is a ruthenium dihydride. The experimental results were supported by the characterization of a plausible catalytic cycle by using DFT/M06. Both cis‐dihydride and trans‐dihydride intermediates were considered, but when the theoretical turnover frequencies (TOFs) were derived directly from the calculated DFT/M06 energies, we found that only the trans‐dihydride pathway was in agreement with the experimentally determined TOFs.
Supramolecular Polymerization at Low Monomer Concentrations: Enhancing Intermolecular Interactions and Suppressing Cyclization by Rational Molecular Design
Authors: Liu Yiliu , Fang Ruochen , Tan Xinxin , Wang Zhiqiang , Zhang Xi 
Published: October 2012

AbstractWe present the construction of long‐chain water‐soluble supramolecular polymers at low monomer concentrations. Naphthalene‐based host‐enhanced π–π interactions, which possess high binding constants, were used as the driving force of supramolecular polymerization. A monomer, DNDAB, with a rigid, bulky 1,4‐diazabicyclo[2.2.2]octane‐1,4‐diium linker was designed. The design of the monomer structure strongly influenced the efficiency of the supramolecular polymerization. The rigid, bulky linker in DNDAB effectively eliminates cyclization, promoting the formation of long‐chain supramolecular polymers at low monomer concentrations. In contrast, a reference monomer containing a flexible linker (DNPDN) only forms oligomers owing to cyclization.
Correlation of Electrocardiographic Changes and Myocardial Fibrosis in Patients With Hypertrophic Cardiomyopathy Detected by Cardiac Magnetic Resonance Imaging
Authors: Song Bong Gun , Yang Hyun Suk , Hwang Hweung Kon , Kang Gu Hyun , Park Yong Hwan , Chun Woo Jung , Oh Ju Hyeon 
Published: October 2012

AbstractBackground:Despite several electrophysiologic and pathologic studies, the cause of electrocardiographic (ECG) changes in patients with hypertrophic cardiomyopathy (HCM) remains unclear. Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging can detect myocardial fibrosis. We aimed to assess the relationship between ECG findings and LGE in such patients.Hypothesis:Myocardial LGE may be associated with ECG changes in HCM.Methods:Seventy consecutive patients with HCM (mean age, 55.5 ± 10.7 years; 47 males) underwent CMR and 12‐lead ECG. The subjects were divided into 3 groups according to the type of hypertrophy: the asymmetric septal hypertrophy group (ASH group, n = 31), the apical hypertrophy group (AP group, n = 22), and concentric hypertrophy group (CH group, n = 17). The transmural and segmental extent, pattern, and location of myocardial LGE were assessed and analyzed in relation to ECG changes.Results:All of the subjects showed some degree of LGE on CMR. The AP group showed significantly higher prevalence of negative T‐wave (P = 0.028) and deep negative T‐wave inversion (P = 0.001) than the ASH and CH groups. The total volume of LGE did not show any significant association with ECG changes. LGE detected at the interventricular septum was associated with increased QRS duration (P = 0.009) and was found in 94% of the ASH group, 59% of the AP group, and 77% of the CH group. LGE at the apex of the heart was present in 32% of the ASH group, 73% of the AP group, and 35% of the CH group and was also associated with negative T‐wave (P = 0.006) and deep negative T‐wave inversion (P = 0.018). Multifocal LGE lesions were associated with increased QRS duration (P = 0.039) as opposed to single nodular or patchy pattern of presence.Conclusions:The location of myocardial LGE in HCM shows significant association with various ECG changes. This may be useful information for initially evaluating subjects with HCM and adds pathophysiological insight into understanding ECG changes in myocardial diseases that cannot be explained otherwise. Clin. Cardiol. 2011 DOI: 10.1002/clc.22062The authors have no funding, financial relationships, or conflicts of interest to disclose.
Outcomes Associated With Warfarin Use in Older Patients With Heart Failure and Atrial Fibrillation and a Cardiovascular Implantable Electronic Device: Findings From the ADHERE Registry Linked to Medicare Claims
Authors: Hess Paul L. , Greiner Melissa A. , Fonarow Gregg C. , Klaskala Winslow , Mills Roger M. , Setoguchi Soko , Al‐Khatib Sana M. , Hernandez Adrian F. , Curtis Lesley H. 
Published: October 2012

AbstractBackground:Warfarin use and associated outcomes in patients with heart failure and atrial fibrillation and a cardiovascular implantable electronic device have not been described previously.Hypothesis:We hypothesized that warfarin is underused and is associated with lower risks of mortality, thromboembolic events, and myocardial infarction.Methods:Using data from a clinical registry linked with Medicare claims, we examined warfarin use at discharge and 30‐day and 1‐year Kaplan‐Meier estimates of all‐cause mortality and cumulative incidence rates of mortality, thromboembolic events, myocardial infarction, and bleeding events in patients 65 years or older, with a history of atrial fibrillation and a cardiovascular implantable electronic device admitted with heart failure between 2001 and 2006, who were naïve to anticoagulation therapy at admission. We compared outcomes between patients who were or were not prescribed warfarin at discharge and tested associations between treatment and outcomes.Results:Of 2586 eligible patients in 252 hospitals, 2049 were discharged without a prescription for warfarin. At 1 year, the group discharged without warfarin had a higher mortality rate after discharge (37.4% vs 28.8%; P < 0.001) but similar rates of thromboembolism, myocardial infarction, and bleeding events. After adjustment, treatment with warfarin was associated with lower risk of all‐cause death 1 year after discharge (hazard ratio: 0.76, 95% confidence interval: 0.63–0.92).Conclusions:Among older patients with heart failure and atrial fibrillation and a cardiovascular implantable electronic device, 4 of 5 were discharged without a prescription for warfarin. Warfarin nonuse was associated with a higher risk of death 1 year after discharge. Clin. Cardiol. 2011 DOI: 10.1002/clc.22064Damon M. Seils, MA, Duke University, assisted with manuscript preparation. Mr. Seils did not receive compensation for his assistance apart from his employment at the institution where the study was conducted.This study was supported by a research agreement between Duke University and Janssen Pharmaceuticals.The authors have no other funding, financial relationships, or conflicts of interest to disclose.
The Speedup‐Test: a statistical methodology for programme speedup analysis and computation
Authors: Touati Sid‐Ahmed‐Ali , Worms Julien , Briais Sébastien 
Published: October 2012

SUMMARYIn the area of high‐performance computing and embedded systems, numerous code optimisation methods exist to accelerate the speed of the computation (or optimise another performance criteria). They are usually experimented by doing multiple observations of the initial and the optimised execution times of a programme in order to declare a speedup. Even with fixed input and execution environment, programme execution times vary in general. Hence, different kinds of speedups may be reported: the speedup of the average execution time, the speedup of the minimal execution time, the speedup of the median and others. Many published speedups in the literature are observations of a set of experiments. To improve the reproducibility of the experimental results, this article presents a rigorous statistical methodology regarding programme performance analysis. We rely on well‐known statistical tests (Shapiro–Wilk's test, Fisher's F‐test, Student's t‐test, Kolmogorov–Smirnov's test and Wilcoxon–Mann–Whitney's test) to study if the observed speedups are statistically significant or not. By fixing 0 < α < 1 a desired risk level, we are able to analyse the statistical significance of the average execution time as well as the median. We can also check if , the probability that an individual execution of the optimised code is faster than the individual execution of the initial code. In addition, we can compute the confidence interval of the probability to obtain a speedup on a randomly selected benchmark that does not belong to the initial set of tested benchmarks. Our methodology defines a consistent improvement compared with the usual performance analysis method in high‐performance computing. We explain in each situation the hypothesis that must be checked to declare a correct risk level for the statistics. The Speedup‐Test protocol certifying the observed speedups with rigorous statistics is implemented and distributed as an open source tool based on R software. Copyright © 2012 John Wiley & Sons, Ltd.
Distribution of random streams for simulation practitioners
Authors: Hill David R. C. , Mazel Claude , Passerat‐Palmbach Jonathan , Traore Mamadou K. 
Published: October 2012

SUMMARYThere is an increasing interest in the distribution of parallel random number streams in the high‐performance computing community particularly, with the manycore shift. Even if we have at our disposal statistically sound random number generators according to the latest and thorough testing libraries, their parallelization can still be a delicate problem. Indeed, a set of recent publications shows it still has to be mastered by the scientific community. With the arrival of multi‐core and manycore processor architectures on the scientist desktop, modelers who are non‐specialists in parallelizing stochastic simulations need help and advice in distributing rigorously their experimental plans and replications according to the state of the art in pseudo‐random numbers parallelization techniques. In this paper, we discuss the different partitioning techniques currently in use to provide independent streams with their corresponding software. In addition to the classical approaches in use to parallelize stochastic simulations on regular processors, this paper also presents recent advances in pseudo‐random number generation for general‐purpose graphical processing units. The state of the art given in this paper is written for simulation practitioners. Copyright © 2012 John Wiley & Sons, Ltd.
GPU‐based acceleration of bio‐inspired motion estimation model
Authors: Ayuso F. , Botella G. , García C. , Prieto M. , Tirado F. 
Published: October 2012

SUMMARYIn this paper, we describe the specific and efficient implementation of a gradient‐based optical flow model. This scheme was particularized using a validated neuromorphic motion estimation system for the robust extraction of image velocity. This model contains many characteristics that enhanced the capability when compared with other optical flow gradient family algorithms. Our implementation was performed using specific graphic processing units designed in an ad hoc framework for this model, which could be reused in several low‐level machine‐vision approaches. Observed performance results indicate that these accelerators be highly recommended. Furthermore, the throughput obtained in comparison with a general CPU was analyzed for the accurateness of a system built with regard to other optical flow systems. Additionally, several visual examples, commonly used for testing motion estimation sequences, were shown to reveal implementation behavior features. Copyright © 2012 John Wiley & Sons, Ltd.
Kinetically Controlled Formation of Formamide Trimer from First Principles
Authors: Szyja Bartłomiej M. , Antoniou Anna , Doltsinis Nikos L. 
Published: October 2012

AbstractThe formation of formamide trimers was simulated using Car–Parrinello molecular dynamics. A variety of different initial setups were compared to study the effects of spatial arrangement, concentration, and temperature on the trimer product distribution. A total of nine different trimer species were obtained by simulation. Although a triangular initial arrangement of the three monomers is found to favour a less energetically stable chain‐like product at high concentration, the more compact global minimum structure is expected to be the most abundant species overall in experiment. This is because there is evidence of a low activation barrier for conversion of the chain‐like trimer to the lowest‐energy structure. For one, this process is observed upon increasing the length of the trajectories. Furthermore, a slight rise in temperature drastically reduces the number of chain‐like trimers. With regard to the intermolecular forces driving the aggregation dynamics, dispersion corrections to the underlying density functional theory description have a strong effect on the product distribution, again favouring the global minimum species. Certain local minimum structures are significantly destabilised relative to the global minimum by dispersion correction while the relative energies of the majority of species are practically unchanged.
Hierarchical Composite of Ag/AgBr Nanoparticles Supported on Bi2MoO6 Hollow Spheres for Enhanced Visible‐Light Photocatalytic Performance
Authors: Tian Guohui , Chen Yajie , Meng Xiangying , Zhou Juan , Zhou Wei , Pan Kai , Tian Chungui , Ren Zhiyu , Fu Honggang 
Published: October 2012

AbstractThe fabrication of multicomponent composite systems may provide benefits in terms of charge separation and the retardation of charge pair recombination. For this purpose, a hierarchical Ag/AgBr/Bi2MoO6 composite was fabricated by using prepared hierarchical floriated Bi2MoO6 hollow spheres as a supporting material. The interleaved nanoflakes assembled in the hierarchical floriated Bi2MoO6 hollow spheres contributed to the stable deposition of Ag/AgBr nanoparticles and the formation of effective nanojunctions, which led to the low recombination rates of the photoinduced electron–hole pairs. The presence of double visible‐light‐active components in the Ag/AgBr/Bi2MoO6 nanojunction system further broadened the visible‐light photoresponse range. As a result, the hierarchical Ag/AgBr/Bi2MoO6 composite exhibited a higher photocatalytic activity than both photocatalysts containing single visible‐light‐active components and crushed Ag/AgBr/Bi2MoO6 nanoparticles for the degradation of alizarin red S (ARS) and phenol. X‐ray photoelectron spectroscopy (XPS) analyses indicated that both AgBr and Ag0 components coexist in the system, and the as‐prepared composite is relatively stable. The improved photoinduced charge‐transfer properties of the hierarchical Ag/AgBr/Bi2MoO6 composite were investigated by using the transient photovoltage (TPV) technique.
Recall of Threat and Submissiveness in Childhood and Psychopathology: The Mediator Effect of Self‐Criticism
Authors: Castilho Paula , Pinto‐Gouveia José , Amaral Vânia , Duarte Joana 
Published: October 2012

Research has robustly shown that early negative parenting experiences are associated with psychopathology and self‐criticism in adulthood. This study investigates recall of personal feelings of perceived threat and subordination in childhood and its relation to psychopathology. In addition, we explore the mediator role of self‐criticism in this association. A sample of 193 subjects from the general population completed self‐report questionnaires measuring the study variables. The mediator analyses suggested that the impact of submissiveness experiences in childhood on depression and anxiety is mediated by self‐criticism. Our findings highlight the route through which the recall of personal feelings of perceived involuntary subordination to parents contributes to depression and anxiety in adulthood. Copyright © 2012 John Wiley & Sons, Ltd.Key Practitioner Message

Although the relation between early experiences of abuse and later psychological problems is now well established, there has been less study on subtler forms of threat and subordinate behaviour in childhood. Given ours and previous findings, therapists should be aware of, and prone to explore, these early experiences.
Most studies exploring early negative experiences mainly refer to attachment theory‐related constructs (e.g., attachment style). We also highlight the importance of noting rank structure and rank style in the family.
Self‐criticism seems to be a key process in the relation between early aversive experiences of subordination and psychopathology.
Given the idea that self‐reassuring operates through a different affect system, helping people develop inner warmth and compassion for the self may be important to counteract feelings of self‐hatred and self‐attack.
An MTJ‐based non‐volatile flip‐flop for high‐performance SoC
Authors: Jung Youngdon , Kim Jisu , Ryu Kyungho , Kim Jung Pill , Kang Seung H. , Jung Seong‐Ook 
Published: October 2012

SUMMARYThe conventional magnetic tunneling junction (MTJ)‐based non‐volatile D flip‐flop (NVDFF) has a slow D‐Q delay and a tradeoff between its D‐Q delay and its sensing current. In addition, a sufficient write current cannot be obtained with the core device, since two MTJs exist in the write path and a write current degradation problem occurs due to the precharge transistors. The proposed MTJ‐based non‐volatile semidynamic flip‐flop (NVSDFF) has a semidynamic structure that ensures a fast D‐Q delay and separates the sensing circuit from the D‐Q signal path to reduce the sensing current without affecting the D‐Q delay. The proposed NVSDFF also provides a sufficient write current by merely using the core device, since only one MTJ exists in the write path. In addition, the head switch, which is added to remove the write current degradation problem, further reduces the sensing current. Thus, the proposed NVSDFF has a higher read disturbance margin than the previous NVDFF with an IO device. The HSPICE simulation results with the industry‐compatible 45 nm model parameter show that the D‐Q delay in the proposed NVSDFF is 50.5% of that of the previous NVDFF with an IO device, and the sensing current, 32.3%. In the proposed NVSDFF, the read disturbance margin is 15.9% larger than in the previous NVDFF with an IO device, and the area is 17.8% smaller. Copyright © 2012 John Wiley & Sons, Ltd.
Structure and Magnetic Behavior of CuII MOFs Supported by 1,2,4‐Triazolyl‐Bifunctionalized Adamantane Scaffold
Authors: Senchyk Ganna A. , Lysenko Andrey B. , Rusanov Eduard B. , Chernega Alexander N. , Jezierska Julia , Domasevitch Konstantin V. , Ozarowski Andrew 
Published: October 2012

AbstractNew triazole‐based CuII metal–organic frameworks, [Cu(tr2ad)(SO4)]·3H2O (1), [Cu3(tr2ad)4(H2O)2(SO4)2]SO4·28H2O (2), [Cu3(tr2ad)4(H2O)4](SiF6)3·16H2O (3), constructed utilizing a rigid adamantane scaffold, tr2ad = 1,3‐bis(1,2,4‐triazol‐4‐yl)adamantane, were prepared hydrothermally, and their crystal structures were determined. The structure of 1 is built up from straight chains of corner‐sharing CuN4O2 octahedra supported by short μ2‐tr (tr = 1,2,4‐triazole) and μ2‐SO42– bridges. The tetradentate character of tr2ad results in the formation of layers. The 2D structures of 2 and 3 consist of discrete secondary building blocks [Cu3(μ2‐N1,N2‐tr)6] with triple [–N–N–] triazole links between the adjacent Cu centers [the Cu‐(tr)‐Cu separations are 3.806 and 3.756 Å for 2 and 3, respectively]. The distorted octahedral N4O2 environment of the peripheral Cu atoms is completed by water molecules and/or terminal sulfate anions. The linear magnetic clusters, which act as nodes, are joined together at average distances of 11.2 and 15.0–15.6 Å into square‐grid‐like networks that exploit the double‐bridging μ3‐ and μ4‐bis(triazole) modules. Uncoordinated counteranions and crystal water molecules fill the interlayer space and channels in the complexes and form extensive H‐bonding patterns. The exchange integrals J1 = 9.8 and J2 ≈ 0 cm–1 for the interaction J1(Ŝ1Ŝ2 + Ŝ2Ŝ3) + J2Ŝ1Ŝ3 were determined for 3 from magnetic susceptibility data and reproduced by a broken‐symmetry DFT calculation. The spin Hamiltonian parameters of 3 were found from high‐field electron paramagnetic resonance (EPR) spectra.
The reciprocal cycle of self‐concealment and trust in romantic relationships
Authors: Uysal Ahmet , Lin Helen Lee , Bush Amber L. 
Published: October 2012

AbstractWe propose that perceived partner concealment, self‐concealment from one's partner (i.e., keeping secrets from one's partner), and trust in one's partner form a reciprocal cycle in romantic relationships. In Study 1, participants in a romantic relationship (N = 94) completed a two‐time point survey within a span of 8 to 10 weeks. Results revealed that perceived partner concealment was associated with a loss of trust in partner, and low trust in partner was associated with an increase in self‐concealment from one's partner. Furthermore, the association between perceived partner concealment and self‐concealment from one's partner was mediated by trust. In Study 2, couples (N = 50) completed daily records for 14 consecutive days. Multilevel analyses indicated that on the days the individuals reported more self‐concealment, their partners reported lower trust in them. Moreover, on the days the partners reported lower trust, the partners also reported higher self‐concealment. These findings suggest that self‐concealment in romantic relationships can create a reciprocal cycle that involves loss of trust and more self‐concealment between partners, which would slowly deteriorate the relationship well‐being. Copyright © 2012 John Wiley & Sons, Ltd.
Leniency for out‐group offenders
Authors: Braun Judith , Gollwitzer Mario 
Published: October 2012

AbstractThe present research investigates leniency for out‐group offenders and differentiates it from the black sheep effect. The authors assume that leniency for out‐group offenders can be used by in‐group members to protect their group's image by displaying that they are not prejudiced. Thus, leniency should disappear when in‐group members have otherwise shown that they are not prejudiced (i.e., moral credentials). In two experiments, offenders' group membership and participants' opportunity to establish moral credentials were manipulated. Results showed that out‐group offenders received the lowest punishment severity ratings (Studies 1 and 2). However, this leniency effect vanished when participants had established moral credentials by either endorsing the participation of out‐group members in lobby groups (Study 1) or writing about a positive experience with an out‐group member (Study 2). These findings suggest that lenient punishments for out‐group offenders may sometimes reflect a relatively easy strategy to display the in‐group as being unprejudiced. Copyright © 2012 John Wiley & Sons, Ltd.