bluuebunny/crossref_metadata_2025 huggingface dataset:
Calculations and Expectations: How engineering students describe three-dimensional forces
Authors: Miller-Young Janice E
Published: July 2013

The premise of student-centered teaching is to respond to the ways in which students engage with the context and content of their learning, and therefore the purpose of this study was to find out how students visualize three-dimensional statics problems from two-dimensional diagrams early in a first-year engineering course. Think-alouds were conducted where students were asked to describe magnitudes and directions of various forces acting in three-dimensional spaces. Three key themes emerged: students have more trouble visualizing points behind, or vectors pointing into, the plane of the page; students may not use contextual clues to aid in their visualization; and students rely on equations to answer problems even when not necessary or even possible to do so. These findings are important to instructors in disciplines where spatial visualization is important because as they are already “experts” in this skill, they may underestimate the difficulty students initially face in approaching these problems. The value of using think-alouds to reveal student thinking as they struggle with concepts is also discussed.
La prémisse de l’enseignement centré sur l’apprenant est de réagir à la manière dont les étudiants s’intéressent réellement au contexte et au contenu de leur apprentissage. En conséquence, le but de cette étude était de découvrir comment les étudiants visualisent les problèmes statiques tridimensionnels à partir de diagrammes bi-dimensionnels, dans un cours de génie de première année. Des exercices de réflexion à haute voix ont été effectués, au cours desquels on a demandé aux étudiants de décrire les magnitudes et les directions de diverses forces qui agissaient dans des espaces tridimensionnels. Trois thèmes clés sont apparus : les étudiants ont davantage de difficulté à visualiser les points qui se trouvent derrière le niveau de la page ou les vecteurs tournés dans la direction de la page; les étudiants n’utilisent pas toujours les indices contextuels dans leur visualisation; et enfin, les étudiants s’appuient sur les équations pour répondre aux problèmes, même quand ce n’est pas nécessaire ou quand c’est impossible à faire. Ces conclusions présentent un grand intérêt pour les enseignants de disciplines où la visualisation spatiale est importante car, puisqu’eux-mêmes sont déjà « experts » dans cette compétence, ils risquent de mésestimer la difficulté à laquelle les étudiants sont confrontés, au début, quand ils essaient de résoudre ces problèmes. L’article discute également de la valeur de l’utilisation d’exercices de réflexion à haute voix pour révéler ce que pensent les étudiants quand ils sont aux prises avec un problème.
Enhancing Assessment in Teacher Education Courses
Authors: Roscoe Keith
Published: July 2013

Several faculty members including the author were involved in exploring the implementation and effectiveness of research-based assessment strategies in their undergraduate teacher education courses at a Canadian university. The paper describes the process and the results of their ongoing improvement efforts and implications for teacher education and higher education in general. After attending several assessment workshops lead by the author, 12 faculty members implemented new assessment strategies in their own courses to enhance student learning. As the 12 faculty members reflected on their efforts to enhance assessment, a number of themes emerged. These included assessment as authentic performance, establishing clear learning targets, collaboration and community, and integrated assessment and instruction. Our results support the claim that current ideas about K-12 assessment are applicable to post-secondary education and can improve student learning outcomes. Developing balanced and integrated assessment systems is perhaps the most significant innovation we engaged in and we conclude that it has the potential to fundamentally change what occurs in university classrooms.
Plusieurs professeurs, y compris l’auteur, ont exploré la mise en oeuvre et l’efficacité de stratégies d’évaluation basées sur la recherche dans le cadre de leurs cours de formation pour les enseignants. L’article décrit le processus et les résultats de leurs efforts pour améliorer la formation des enseignants et plus généralement l’enseignement, ainsi que les implications de cette approche.
Après avoir participé à plusieurs ateliers sur l’évaluation dirigés par l’auteur, 12 professeurs ont mis en oeuvre de nouvelles stratégies d’évaluation dans leurs propres cours pour améliorer l’apprentissage des étudiants. Quand les 12 professeurs ont réfléchi sur leurs efforts pour améliorer l’évaluation, un certain nombre de thèmes sont apparus, entre autres : l’évaluation en tant que performance authentique, l’établissement d’objectifs d’apprentissage clairs, la collaboration et la communauté, l’intégration de l’évaluation et de l’instruction. Nos résultats étayent l’affirmation selon laquelle les théories actuelles sur l’évaluation dans les écoles (K-12) sont applicables en enseignement post-secondaire et peuvent améliorer l’apprentissage des étudiants. Le développement de systèmes d’évaluation équilibrés et intégrés est peut-être l’innovation la plus importante dans laquelle nous nous engageons et nous en concluons que cette pratique a le potentiel de changer radicalement ce qui se passe dans les salles de classe des universités.
The Copyright Modernization Act: A Guide for Post-Secondary Instructors
Authors: Soper Devin
Published: July 2013

In November 2012, the educational provisions of the Copyright Modernization Act were proclaimed in force, thereby introducing a number of significant changes to the Canadian Copyright Act. These changes include the expansion of fair dealing to include the purpose of education, the addition of new educational exceptions for the online transmission of lessons and the use of work freely available through the internet, and a number of amendments that make existing educational exceptions more technologically accommodating. This paper considers the significance of these changes for post-secondary instructors, first contextualizing the changes in relation to recent fair dealing jurisprudence, and then considering their significance for everyday instructional practice. Drawing on influential court decisions and the commentary of academics and lawyers, the paper not only describes how the changes to the Copyright Act have expanded the rights and exceptions available to instructors, but also identifies a number of unresolved questions about how the changes should be applied in practice. Despite these areas of uncertainty, the paper concludes that the changes bode well for post-secondary instructors, as they relax many long-standing restrictions around the use of copyrighted works for educational purposes.
En novembre 2012, les dispositions éducatives de la Loi sur la modernisation du droit d’auteur ont été proclamées avec force. Elles apportaient un certain nombre de changements significatifs à la Loi du Canada sur le droit d’auteur. Ces changements comprennent l’élargissement de l’utilisation équitable pour y inclure le but de l’éducation, l’addition de nouvelles exceptions éducatives pour la transmission de leçons en ligne et l’utilisation de travaux disponibles à volonté sur internet, ainsi qu’un certain nombre de modifications aux exceptions éducatives existantes qui tiennent davantage compte de la technologie. Cet article examine la signification de ces changements pour les enseignants de niveau post-secondaire, tout d’abord en mettant en contexte les changements par rapport à la jurisprudence récente en matière d’élargissement de l’utilisation, ensuite en examinant leur signification pour la pratique de l’enseignement de tous les jours. L’article, qui met à profit les décisions de la cour et les commentaires d’universitaires et d’avocats, non seulement décrit la manière dont les changements apportés à la Loi du droit d’auteur ont élargi les droits et les exceptions à la disposition des enseignants, il identifie également un certain nombre de questions non résolues sur la manière dont les changements devraient être mis en pratique. Malgré ces zones d’incertitude, l’article en arrive à la conclusion que les changements sont de bon augure pour les enseignants de niveau post-secondaire car ils assouplissent de nombreuses restrictions qui existaient de longue date concernant l’utilisation de travaux protégés par le droit d’auteur pour les besoins éducatifs.
Dysphagia lusoria: A review of the literature and a case report of a young lady presenting with atypical chest pain
Authors: Almarri Mohammed , Mahfouz Ahmed Emad , Al-Adba Hamad Saadon , Al Ani Rafid S. Hamid , Almarri Nood D.
Published: July 2013

The term Dysphagia lusoria refers to an extraordinary disposition of the subclavian artery (lusorian artery) as a cause of oesophageal obstruction. Although most individuals are asymptomatic, they might present with unspecific thoracic pain, dysphagia, dyspnea, arterioesophageal or arteriotracheal fistulae with hematemesis or hemoptysis. This paper presents the first case report in Qatar of a young lady presented with atypical chest pain resulting from dysphagia lusoria caused by a right aortic arch with a diverticulum (of Kommerell) at the origin of an aberrant left subclavian artery and a review of the literature.
Soyasaponin I, III, and Soyasapogenol B Inhibit Proliferation and Modulate PKC Expression in Caco-2 Human Colon Cancer Cells
Authors: Salyer Joseph , Eswaranandam Satchithanandam , LEE Sun-Ok
Published: July 2013

Group B saponins, the predominant form of saponins in heat-treated soy products, have been shown to possess hypocholesterolemic, antimutagenic, and anticarcinogenic properties. Previous studies have evaluated crude mixtures of soyasaponins, but studies evaluating a single purified soyasaponin as an anticarcinogenic agent are limited. The goal of this study is to examine the effects of purified soyasaponins I and III as well as their aglycone form, soyasapogenol B, as anticarcinogenic agents on the human colon adenocarcinoma cell line (Caco-2). Experiments were conducted to examine the effects of purified soyasaponins on cell proliferation, Protein Kinase C (PKC) activity, and cell morphology in Caco-2 cell cultures. Treatment of cells with soyasaponins I and III at concentrations of 0.3-0.9 mg/ml significantly reduced viable cell numbers after 48 and 72 hours of exposure by 8.6-65.3% (p < 0.05). Soyasapogenol B at a concentration of 0.15 mg/ml significantly reduced viable cell numbers after 24 hours by 62.4% (p < 0.05). Cell morphology changes demonstrated that as concentrations and lipophilicity of soyasaponins increased, cell membranes became rougher and more irregular. Treatment of cells for 72 hours significantly reduced the amount of PKC activity by 9-40% (p < 0.05). Results indicate that purified soyasaponins I, III and soyasapogenol B can suppress Caco-2 colon cancer cell proliferation. These findings suggest that purified group B soyasaponins and their final metabolite soyasapogenol B may be a colon-cancer suppressive component of soy that warrants further examination as a potential nutraceutical or functional food.
Community and Ritual Within the Mississippian Center at Town Creek
Authors: Boudreaux Edmond A.
Published: July 2013

This article evaluates aspects of an occupational history that was developed for the Town Creek site, a small Mississippian center in the North Carolina Piedmont that was occupied sometime between A.D. 1150–1400. Town Creek’s occupational history suggests that its Mississippian community consisted of multiple, discrete household groups, and that these groups were important throughout the center’s existence. Analyses of architectural, mortuary, and ceramic data indicate that Town Creek began as a town with a substantial domestic population, but it evolved into more of a vacant center later in time. This decline in domestic population coincided with significant evidence for site-wide ritual activity that included the construetion of a platform mound and the use of cemeteries in former house locations. Parallels between the small center at Town Creek and some of the largest Mississippian centers, especially the persistence of household-group spaces and an emphasis on ritual activities later in time, suggest that interaction among discrete social groups within a ritual context was a salient part of being Mississippian.
A Contextual and Iconographic Reassessment of the Headdress on Burial 11 From Hopewell Mound 25
Authors: Giles Bretton T.
Published: July 2013

I explore in this paper the significance of the headdress interred on Burial 11 under Hopewell Mound 25 by reexamining its archaeological context and the history of its interpretation. Following Shetrone’s (1926) initial interpretation, I argue that it was an avian headdress that specifically portrayed a two-headed raptor. I support this reassessment with an iconographie analysis of related representations from the Central Ohio River Valley, especially the imagery engraved on a femur from Hopewell Mound 25. I also delve into what these two-headed raptors might have meant to people in the Eastern Woodlands.
Accelerator Mass Spectrometry14C Dating and the Antiquity of Shell-Tempered Ceramics from the Chesapeake Bay and Middle Atlantic
Authors: Rick Torben C. , Lowery Darrin L.
Published: July 2013

Ceramics typologies have long been used to build artifact, site, and regional chronologies. Direct accelerator mass spectrometry (AMS)14C dating of shell-tempered ceramics offers a promising tool for updating and improving these chronologies. Few studies have14C dated shell fragments from shell-tempered pottery, however, and questions remain about potential biases from “old shell,” the reservoir effect, and other variables. Forty-five direct AMS14C assays on shell-tempered pottery and associated shell, charcoal, and bone from nine archaeological sites in Virginia and Maryland provide a framework to test this method. AMS14C assays from one site may have problems with old shell, but most of the calibrated direct and associated age estimates overlap. One of our samples is the oldest securely dated shell-tempered pottery in North America at ~1000 cal B.C. Our study demonstrates the promise of AMS14C dating shell-tempered pottery for refining ceramic and regional chronologies in coastal and other areas around the world.
Disorders of left ventricular trabeculation/compaction or right ventricular wall formation
Authors: Shieh Joseph T.C. , Jefferies John L. , Chin Alvin J.
Published: July 2013

Cardiomyopathies are remarkably variable in form. Although hearts may be dilated or hypertrophic, the spectrum of cardiomyopathies includes left ventricular noncompaction/hypertrabeculation and right ventricular wall disorders. These conditions have been increasingly recognized in patients given advances in clinical diagnostics. Here we present information on cardiac pathophysiology, from ventricular wall formation and trabeculae in model organisms to pediatric and adult disease. Many genes to affect the ventricular phenotype, and this has implications for deciphering developmental and disease pathways and for applying testing for clinical care. © 2013 Wiley Periodicals, Inc.
Significance of grooming behavior in two polygynous groups of western black crested gibbons: Implications for understanding social relationships among immigrant and resident group members
Authors: Guan Zhen‐Hua , Huang Bei , Ning Wen‐He , Ni Qing‐Yong , Sun Guo‐Zheng , Jiang Xue‐Long
Published: July 2013

In primates, grooming is considered among the most common behaviors for maintaining social bonds; however, to date, few studies have examined grooming behavior in gibbon species in detail. We used both a 5‐min interval scan method and social network analysis to study grooming in two groups of polygynous western black‐crested gibbon (Nomascus concolor) in Wuliang Mountain, Central Yunnan, China. Individuals in both groups spent little time in social grooming (1.45% and 1.97% of active time). We compared the two groups' grooming networks and found that the group that maintained a more stable social unit had a more complex grooming network while the group with new immigrants had a grooming network characterized by fewer grooming pairs. Females in both groups played important roles in the grooming network. A newly immigrant female spent the most time grooming others and chose the resident adult female as her main adult grooming partner. Other females from both groups chose the adult male as their primary grooming partner (except their offspring). A sub‐adult male who had resided in his natal group for 2 years after maturing into an adult also groomed more and was at the center of the network. This male finally replaced the breeding male in his group 3 years after our data collection period ended. We hypothesize that the immigrant female and the resident young adult male engaged in more extensive grooming interactions as a behavioral strategy to gain tolerance from long‐term residents. Our results suggest that female gibbons in polygynous groups actively cooperate in maintaining social relationships rather than co‐exist through tolerance or avoidance. Our observations indicate that grooming networks in crested gibbons reflect individual dynamics and partly support the social cohesion hypothesis for primate grooming. In this regard, we suggest that changes in gibbon grooming networks can be used to predict social change. Am. J. Primatol. 75:1165–1173, 2013. © 2013 Wiley Periodicals, Inc.
The degradation and charring of flame retarded epoxy resin during the combustion
Authors: Zhang Wenchao , Li Xiangmei , Yang Rongjie
Published: July 2013

To study flame retardant mechanism of epoxy resin (EP) by octaphenyl silsesquioxane and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide, an experimental method is set up to investigate the residue of the EPs, which is extinguished during the cone calorimeter testing at different times. The chemical structures of the residues are investigated by the FTIR and XPS. The breakdown of EPs network and formation of new crosslinking structure are supported by the FTIR analysis. The changes of C and O concentrations in the condensed phase during the combustion are investigated by XPS in detail. Moreover, formation of organic carbon is uncovered by the plasmon loss curves based on XPS that could track the carbon crosslinking. These results exhibited a whole degradation and charring process of EP during the combustion: degradation of EP chain, more crosslinking charring, and thermal oxidation of the char. Furthermore, a program of combustion and degradation process of EPs is described in this research. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4119–4128, 2013
Effects of nano‐TiO2 on the properties and structures of starch/poly(ε‐caprolactone) composites
Authors: Fei Peng , Shi Yongjun , Zhou Man , Cai Jie , Tang Shangwen , Xiong Hanguo
Published: July 2013

Poor physical properties resulting from low interfacial interactions between hydrophilic biopolymers and hydrophobic thermoplastic matrices have been one of the biggest obstacles in preparing quality biomass materials. This study concentrates on the effects of nano‐TiO2 on the properties and structure of starch/poly (ε‐caprolactone) (PCL) composites. The molecular and crystal structures of the composites were characterized by using Fourier transform infrared spectroscopy, differential scanning calorimeter (DSC), X‐ray diffraction (XRD), and field emission scanning electron microscope. The results indicated that an interpenetrating network structure formed by adding nano‐TiO2 into starch/PCL composites. The DSC and XRD analysis indicated that the crystallinity degree and the crystallization rate of the composites reduced, whereas the crystal form and crystal size were unchanged. The results also showed that the mechanical properties and water resistance of the composites were improved significantly with the addition of nano‐TiO2, whereas their transparency decreased. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4129–4136, 2013
Issues of work–life balance among JASIST authors and editors
Authors: Cabanac Guillaume , Hartley James
Published: July 2013

Many dedicated scientists reject the concept of maintaining a “work–life balance.” They argue that work is actually a huge part of life. In the mind‐set of these scientists, weekdays and weekends are equally appropriate for working on their research. Although we all have encountered such people, we may wonder how widespread this condition is with other scientists in our field. This brief communication probes work–life balance issues among JASIST authors and editors. We collected and examined the publication histories for 1,533 of the 2,402 articles published in JASIST between 2001 and 2012. Although there is no rush to submit, revise, or accept papers, we found that 11% of these events happened during weekends and that this trend has been increasing since 2005. Our findings suggest that working during the weekend may be one of the ways that scientists cope with the highly demanding era of “publish or perish.” We hope that our findings will raise an awareness of the steady increases in work among scientists before it affects our work–life balance even more.
One‐Pot Synthesis of Phenylmethanethiolate‐Protected Au20(SR)16 and Au24(SR)20 Nanoclusters and Insight into the Kinetic Control
Authors: Zhu Xiuyi , Jin Shenshen , Wang Shuxin , Meng Xiangming , Zhu Changwei , Zhu Manzhou , Jin Rongchao
Published: July 2013

We report two synthetic routes for concurrent formation of phenylmethanethiolate (‐SCH2Ph)‐protected Au20(SR)16 and Au24(SR)24 nanoclusters in one‐pot by kinetic control. Unlike the previously reported methods for thiolate‐protected gold nanoclusters, which typically involve rapid reduction of the gold precursor by excess NaBH4 and subsequent size focusing into atomically monodisperse clusters of a specific size, the present work reveals some insight into the kinetic control in gold–thiolate cluster synthesis. We demonstrate that the synthesis of ‐SCH2Ph‐protected Au20 and Au24 nanoclusters can be obtained through two different, kinetically controlled methods. Specifically, route 1 employs slow addition of a relatively large amount of NaBH4 under slow stirring of the reaction mixture, while route 2 employs rapid addition of a small amount of NaBH4 under rapid stirring of the reaction mixture. At first glance, these two methods apparently possess quite different reaction kinetics, but interestingly they give rise to exactly the same product (i.e., the coproduction of Au20(SCH2Ph)16 and Au24(SCH2Ph)20 clusters). Our results explicitly demonstrate the complex interplay between the kinetic factors that include the addition speed and amount of NaBH4 solution as well as the stirring speed of the reaction mixture. Such insight is important for devising synthetic routes for different sized nanoclusters. We also compared the photoluminescence and electrochemical properties of PhCH2S‐protected Au20 and Au24 nanoclusters with the PhC2H4S‐protected counterparts. A surprising 2.5 times photoluminescence enhancement was observed for the PhCH2S‐capped nanoclusters when compared to the PhC2H4S‐capped analogues, thereby indicating a drastic effect of the ligand that is merely one carbon shorter.
Adaptive Dynamic Surface Control with Guaranteed L∞ Tracking Performance for a Class of Uncertain Nonlinear Systems with Unknown Time Delays
Authors: Qu Weiran , Lin Yan , Zhao Qichao
Published: July 2013

This paper is aimed at exploring dynamic surface control (DSC) for a class of uncertain nonlinear systems in strict‐feedback form with time delays. Combining the Finite Covering Lemma (Heine‐Borel Theorem) with neural networks, a novel method is proposed to approximate time delay terms, which leads to the abandonment of traditional Lyapunov‐Krasovskii functionals. Then, a surface error modification and an initialization technique are proposed to guarantee the tracking performance. Moreover, by applying a newly‐developed neural network based adaptive control technique, it is shown that the update law for the proposed DSC scheme is needed only at the last design step with only one parameter being estimated online, which significantly reduces the computational burden, compared with current DSC schemes. Simulation results are presented to illustrate the efficiency of the proposed scheme.
Fifty years of DNA “Breathing”: Reflections on old and new approaches
Authors: von Hippel Peter H. , Johnson Neil P. , Marcus Andrew H.
Published: July 2013

The coding sequences for genes, and much other regulatory information involved in genome expression, are located ‘inside’ the DNA duplex. Thus the “macromolecular machines” that read‐out this information from the base sequence of the DNA must somehow access the DNA “interior.” Double‐stranded (ds) DNA is a highly structured and cooperatively stabilized system at physiological temperatures, but is also only marginally stable and undergoes a cooperative “melting phase transition” at temperatures not far above physiological. Furthermore, due to its length and heterogeneous sequence, with AT‐rich segments being less stable than GC‐rich segments, the DNA genome ‘melts’ in a multistate fashion. Therefore the DNA genome must also manifest thermally driven structural (“breathing”) fluctuations at physiological temperatures that should reflect the heterogeneity of the dsDNA stability near the melting temperature. Thus many of the breathing fluctuations of dsDNA are likely also to be sequence dependent, and could well contain information that should be “readable” and useable by regulatory proteins and protein complexes in site‐specific binding reactions involving dsDNA “opening.” Our laboratory has been involved in studying the breathing fluctuations of duplex DNA for about 50 years. In this “Reflections” article we present a relatively chronological overview of these studies, starting with the use of simple chemical probes (such as hydrogen exchange, formaldehyde, and simple DNA “melting” proteins) to examine the local stability of the dsDNA structure, and culminating in sophisticated spectroscopic approaches that can be used to monitor the breathing‐dependent interactions of regulatory complexes with their duplex DNA targets in “real time.” © 2013 Wiley Periodicals, Inc. Biopolymers 99: 923–954, 2013.
NMR‐profiles of protein solutions
Authors: Pedrini Bill , Serrano Pedro , Mohanty Biswaranjan , Geralt Michael , Wüthrich Kurt
Published: July 2013

NMR‐Profiles are quantitative one‐dimensional (1D) presentations of 2D [15N,1H]‐correlation spectra used to monitor the quality of protein solutions prior to and during NMR structure determinations and functional studies. In our current use in structural genomics projects, an NMR‐Profile is recorded at the outset of a structure determination, using a uniformly 15N‐labeled microscale sample of the protein. We thus assess the extent to which polypeptide backbone resonance assignments can be achieved with given NMR techniques, for example, conventional triple resonance experiments or APSY‐NMR. With the availability of sequence‐specific polypeptide backbone resonance assignments in the course of the structure determination, an “Assigned NMR‐Profile” is generated, which visualizes the variation of the 15N–1H correlation cross peak intensities along the sequence and thus maps the sequence locations of polypeptide segments for which the NMR line shapes are affected by conformational exchange or other processes. The Assigned NMR‐Profile provides a guiding reference during later stages of the structure determination, and is of special interest for monitoring the protein during functional studies, where dynamic features may be modulated during physiological processes. © 2013 Wiley Periodicals, Inc. Biopolymers 99: 825–831, 2013.
Randomized clinical trial of angiotensin-converting enzyme inhibitor, ramipril, in patients with intermittent claudication
Authors: Shahin Y , Cockcroft J R , Chetter I C
Published: July 2013

Background

The aim was to investigate the effect of ramipril on clinical parameters in patients with peripheral arterial disease.

Methods

Patients with intermittent claudication were randomized to receive ramipril or placebo for 24 weeks in a double-blind study. Outcome measures were walking distance, arterial stiffness measurement and quality of life (QoL).

Results

A total of 33 patients were included (25 men; mean(s.d.) age 64·6(7.8) years); 14 received ramipril and 19 placebo. After 24 weeks, ramipril improved maximum treadmill walking distance by an adjusted mean (95 per cent confidence interval, c.i.) of 131 (62 to 199) m (P = 0·001), improved treadmill intermittent claudication distance by 122 (56 to 188) m (P = 0·001) and improved patient-reported walking distance by 159 (66 to 313) m (P = 0·043) compared with placebo. Ramipril reduced carotid femoral pulse wave velocity by –1·47 (95 per cent c.i. –2·40 to –0·57) m/s compared with placebo (P = 0·002). Resting ankle : brachial pressure index (ABPI) improved slightly in both ramipril and placebo groups (0·02 (95 per cent c.i. –0·08 to 0·11) versus 0·03 (–0·05 to 0·10); P = 0·830). Ramipril had a slight, non-significant effect on QoL physical domains compared with placebo.

Conclusion

Ramipril improved walking distance in patients with claudication; however, this improvement was not related to improved ABPI but might have been due to ramipril reducing arterial stiffness. Registration number: NCT01037530 (http://www.clinicaltrials.gov).
Economic analysis of a randomized trial of percutaneous angioplasty, supervised exercise or combined treatment for intermittent claudication due to femoropopliteal arterial disease
Authors: Mazari F A K , Khan J A , Carradice D , Samuel N , Gohil R , McCollum P T , Chetter I C
Published: July 2013

Background

The aim was to compare costs and utilities of percutaneous transluminal angioplasty (PTA), a supervised exercise programme (SEP) and combined treatment (PTA + SEP) in patients with intermittent claudication (IC) to establish the most cost-effective treatment.

Methods

Patients with IC due to femoropopliteal disease were randomized to receive PTA, SEP or PTA + SEP. Assessments were performed before, and at 1, 3, 6 and 12 months postintervention. Clinical and quality-of-life indicators were recorded. The SF-6D Health Utilities index was calculated from the Short Form 36, plotted, and quality-adjusted life-years (QALYs) were generated by calculating the area under the curve. Costs were calculated using National Health Service 2009–2010 payment-by-results tariffs and the National Institute for Health Research Clinical Research Network Investigation pricing index, and adjusted for reinterventions. Cost per QALY and incremental costs were calculated, and sensitivity analyses performed.

Results

A total of 178 patients (PTA, 60; SEP, 60; PTA + SEP, 58) were randomized. All treatments resulted in significant improvement in the SF-6D index (P < 0·001). There was no significant difference between treatments in mean QALYs gained (PTA: 0·620, 95 per cent confidence interval 0·588 to 0·652; SEP: 0·629, 0·597 to 0·660; PTA + SEP: 0·649, 0·622 to 0·675). The adjusted mean cost per procedure was significantly higher for PTA (€7301·74) compared with SEP (€3866·49) and PTA + SEP (€6911·68) (P < 0·001). The cost per QALY was significantly higher for PTA (€11 777·00) compared with SEP (€6147·04) and PTA + SEP (€10 649·74). QALYs were lost when PTA alone was used as first-line treatment in comparison with SEP or PTA + SEP. These results were robust and valid in sensitivity analyses.

Conclusion

Supervised exercise is the most cost-effective first-line treatment for IC, and when combined with PTA is more cost-effective than PTA alone.
Kinase in Motion: Insights into the Dynamic Nature of p38α by High‐Pressure NMR Spectroscopic Studies
Authors: Nielsen Gerd , Jonker Hendrik R. A. , Vajpai Navratna , Grzesiek Stephan , Schwalbe Harald
Published: July 2013

Protein kinases are highly dynamic and complex molecules. Here we present high‐pressure and relaxation studies of the activated p38α mitogen‐activated protein kinase (MAPK). p38α plays a central role in inflammatory diseases such as rheumatoid arthritis and is therefore a highly attractive pharmaceutical target. The combination of high pressure and NMR spectroscopy allowed for a detailed per‐residue based assessment of the structural plasticity of p38α and the accessibility of low‐lying excited‐energy conformations throughout the kinase structure. Such information is uniquely accessible through the combination of liquid‐state NMR and high pressure and is of considerable value for the drug discovery process. The interactions of p38α and DFG‐in and DFG‐out ligands were studied under the application of high pressure, and we demonstrate how we can alter kinase dynamics by pressure in a similar way to what has previously only been observed by ligand binding. Pressure is shown to be a mild and efficient tool for manipulation of intermediate‐timescale dynamics.
Dynamics and Control of Coupled Continuous Chromatography and Crystallization Processes for the Production of Pure Enantiomers
Authors: Swernath S. , Kaspereit M. , Kienle A.
Published: July 2013

The combination of continuous chromatographic processes and subsequent crystallization with a recycle of the mother liquor can improve significantly the efficiency of separation processes for the production of enantiomers if compared to the stand‐alone chromatographic process. For the first time, dynamic operability and plantwide control of such a process combination is investigated. In the first step, the effect of disturbances on the open loop dynamics is evaluated. In a second step, a simple plantwide control strategy is proposed in order to ensure a robust process operation. It is demonstrated that the direct control of the simulated moving bed (SMB) unit is not required to stabilize the process combination while maintaining the desired product specifications. Instead, this can be achieved easily by controlling the amount of solvent removed or added to the system.
Electrochemical and Photoelectrochemical Properties of the Copper Hydroxyphosphate Mineral Libethenite
Authors: Li Man , Cheng Qian , Wittman Reed M. , Peng Xihong , Chan Candace K.
Published: July 2013

There has been much interest recently in the discovery of new, non‐oxide materials for photoelectrochemical applications. The copper hydroxyphosphate mineral libethenite, Cu2(OH)PO4 (CHP), which has a Jahn–Teller distorted structure and d9 electron configuration, has recently been reported to display photocatalytic activity. To better understand the properties of this material, a detailed investigation of the relevant fundamental characteristics such as the flatband potential, conduction type, and band diagram was performed using electrochemical and photoelectrochemical methods on CHP thin films deposited onto fluorine‐doped tin oxide (FTO) substrates. Density functional theory was used to calculate the band structure, effective mass of electrons and holes, and vacancy formation energies in CHP. CHP was found to be active for electrochemical water oxidation, as confirmed by quantitative O2 measurements. Possible factors behind the low photocurrents observed in linear scanning voltammetry are discussed. Better understanding of this material may lead to the development of improved catalysts and photocatalysts from natural mineral sources.
Theory of Kinetically Controlled Electrode Reaction Coupled to Ion Transfer across the Liquid/Liquid Interface
Authors: Komorsky‐Lovrić Šebojka , Lovrić Milivoj
Published: July 2013

An electron‐transfer reaction at a graphite electrode covered by a thin film of an organic solvent that is immiscible with water, immersed into an aqueous electrolyte solution, is studied theoretically. The redox couple is confined within the film, and conductivity is achieved by the transfer of an anion of supporting electrolyte across the organic solvent/water interface. In linear scan voltammetry, the peak potential depends on the initial concentration of either the reactant or the anion of supporting electrolyte in the film. A critical value of the dimensionless kinetic parameter κ, which can be used to determine the standard rate constant, is calculated.
Fibrous Networks with Incorporated Macrocycles: A Chiral Stimuli‐Responsive Supramolecular Supergelator and Its Application to Biocatalysis in Organic Media
Authors: Qi Zhenhui , Wu Changzhu , Malo de Molina Paula , Sun Han , Schulz Andrea , Griesinger Christian , Gradzielski Michael , Haag Rainer , Ansorge‐Schumacher Marion B. , Schalley Christoph A.
Published: July 2013

A new and versatile, crown ether appended, chiral supergelator has been designed and synthesized based on the bis‐urea motif. The introduction of a stereogenic center improved its gelation ability significantly relative to its achiral analogue. This low‐molecular‐weight gelator forms supramolecular gels in a variety of organic solvents. It is sensitive to multiple chemical stimuli and the sol–gel phase transitions can be reversibly triggered by host–guest interactions. The gel can be used to trap enzymes and release them on demand by chemical stimuli. It stabilizes the microparticles in Pickering emulsions so that enzyme‐catalyzed organic reactions can take place in the polar phase inside the microparticles, the organic reactants diffusing through the biphasic interface from the surrounding organic phase. Because of the higher interface area between the organic and polar phases, enzyme activity is enhanced in comparison with simple biphasic systems.
Phototriggered Release of a Leaving Group in Ketoprofen Derivatives via a Benzylic Carbanion Pathway, But not via a Biradical Pathway
Authors: Li Ming‐De , Su Tao , Ma Jiani , Liu Mingyue , Liu Han , Li Xuechen , Phillips David Lee
Published: July 2013

2‐Acetoxymethyl‐2‐(3‐benzoylphenyl)propionic acid (KP‐OAc) was used as a model to elucidate the solvent‐mediated photochemistry mechanism of Ketoprofen (KP). In solutions with a low concentration of water, KP‐OAc exhibits a benzophenone‐like photochemistry, reacting with water molecules through some reaction to form a ketyl radical intermediate. In neutral solutions with a high concentration of water or acidic solutions, KP‐OAc undergoes a photodecarboxylation reaction with the assistance of water molecules or with the catalysis of perchloric acid to directly generate a biradical intermediate that cannot induce the phototrigger reaction to release the AcO− group. Therefore, the lifetime of the biradical intermediate of KP‐OAc is almost same as that of the biradical intermediate formed from KP in the same kinds of solutions. However, the photodecarboxylation of KP‐OAc in phosphate buffer solution directly produces the benzylic carbanion intermediate, which can induce the phototrigger reaction to release the AcO− group. Therefore, the lifetime of the biradical intermediate of KP‐OAc is significantly shorter than the lifetime of the biradical intermediate of KP in phosphate buffer solution. Interestingly, the investigation of the photochemistry of KP‐OAc not only verifies the solvent‐mediated photochemistry mechanism of KP but also provides some new insight into the potential of using this kind of platform for phototrigger applications. The biradical intermediate is not the key species leading to the phototrigger reaction but the benzylic carbanion species is the key reactive intermediate that can mediate the phototrigger reaction of KP‐OAc. Therefore, a change in the pH of the solutions can be utilized to switch on and switch off the photorelease reactions of KP derivative phototrigger compounds.
Photosynthetic Antenna‐Reaction Center Mimicry with a Covalently Linked Monostyryl Boron‐Dipyrromethene–Aza‐Boron‐Dipyrromethene–C60 Triad
Authors: Shi Wen‐Jing , El‐Khouly Mohamed E. , Ohkubo Kei , Fukuzumi Shunichi , Ng Dennis K. P.
Published: July 2013

An efficient functional mimic of the photosynthetic antenna‐reaction center has been designed and synthesized. The model contains a near‐infrared‐absorbing aza‐boron‐dipyrromethene (ADP) that is connected to a monostyryl boron‐dipyrromethene (BDP) by a click reaction and to a fullerene (C60) using the Prato reaction. The intramolecular photoinduced energy and electron‐transfer processes of this triad as well as the corresponding dyads BDP‐ADP and ADP‐C60 have been studied with steady‐state and time‐resolved absorption and fluorescence spectroscopic methods in benzonitrile. Upon excitation, the BDP moiety of the triad is significantly quenched due to energy transfer to the ADP core, which subsequently transfers an electron to the fullerene unit. Cyclic and differential pulse voltammetric studies have revealed the redox states of the components, which allow estimation of the energies of the charge‐separated states. Such calculations show that electron transfer from the singlet excited ADP (1ADP*) to C60 yielding ADP.+‐C60.− is energetically favorable. By using femtosecond laser flash photolysis, concrete evidence has been obtained for the occurrence of energy transfer from 1BDP* to ADP in the dyad BDP‐ADP and electron transfer from 1ADP* to C60 in the dyad ADP‐C60. Sequential energy and electron transfer have also been clearly observed in the triad BDP‐ADP‐C60. By monitoring the rise of ADP emission, it has been found that the rate of energy transfer is fast (≈1011 s−1). The dynamics of electron transfer through 1ADP* has also been studied by monitoring the formation of C60 radical anion at 1000 nm. A fast charge‐separation process from 1ADP* to C60 has been detected, which gives the relatively long‐lived BDP‐ADP.+C60.− with a lifetime of 1.47 ns. As shown by nanosecond transient absorption measurements, the charge‐separated state decays slowly to populate mainly the triplet state of ADP before returning to the ground state. These findings show that the dyads BDP‐ADP and ADP‐C60, and the triad BDP‐ADP‐C60 are interesting artificial analogues that can mimic the antenna and reaction center of the natural photosynthetic systems.
Ionic Aggregates of Lithium Organocuprates
Authors: Putau Aliaksei , Wilken Mona , Koszinowski Konrad
Published: July 2013

We have used a combination of electrospray ionization mass spectrometry and electrical conductivity measurements to analyze solutions of the Gilman cuprates LiCuR2⋅LiX, with R=Ph, Bu and X=Cl, Br, I, in tetrahydrofuran and have compared our findings with previous results on cyanocuprates LiCuR2⋅LiCN. Among the various polynuclear organocuprate ions observed, Li2Cu3Ph6−, LiCu4Ph6−, and Cu5Ph6− are of particular interest because aggregates of the same composition are known from X‐ray crystal structures. Control experiments have indicated that the polynuclear organocuprate anions detected in solution are indeed identical to those formed in the solid state. As abundant ions of the type Li2Cu3R6− are found in solutions of Gilman cuprates and cyanocuprates alike, their possible involvement in organocuprate reactions should be considered. For comparison, we have also included solutions of LiCu(R)I, LiCuX2⋅LiX, LiCuX2, and CuCN⋅2 LiX in the present study.
Disila‐Galaxolide and Derivatives: Synthesis and Olfactory Characterization of Silicon‐Containing Derivatives of the Musk Odorant Galaxolide
Authors: Dörrich Steffen , Bauer Jennifer B. , Lorenzen Sabine , Mahler Christoph , Schweeberg Sarah , Burschka Christian , Baus Johannes A. , Tacke Reinhold , Kraft Philip
Published: July 2013

A series of silicon‐containing derivatives of the polycyclic musk odorant galaxolide (4 a) was synthesized, that is, disila‐galaxolide ((4RS,7SR)‐4 b/(4RS,7RS)‐4 b), its methylene derivative rac‐9, and its nor analogue rac‐10. The tricyclic title compounds with their 7,8‐dihydro‐6,8‐disila‐6 H‐cyclopenta[g]isochromane skeleton were prepared in multistep syntheses by using a cobalt‐catalyzed [2+2+2] cycloaddition of the mono‐ yne H2CCHCH2OCH2CCB(pin) (B(pin)=4,4,5,5‐tetramethyl‐1,3,2‐di‐ oxaborolan‐2‐yl) with the diynes H2CC[Si(CH3)2CCH]2 or H2C‐ [Si(CH3)2CCH]2 as the key step. Employing [Cr(CO)3(MeCN)3] as an auxiliary, the disila‐galaxolide diastereomers (4RS,7SR)‐4 b and (4RS,7RS)‐4 b could be chromatographically separated through their tricarbonylchromium(0) complexes, followed by oxidative decomplexation. The identity of the title compounds and their precursors was established by elemental analyses and multinuclear NMR spectroscopic studies and in some cases additionally by crystal structure analyses. Compounds (4RS,7SR)‐4 b, (4RS,7RS)‐4 b, rac‐9, and rac‐10 were characterized for their olfactory properties, including GC‐olfactory studies of the racemic compounds on a chiral stationary phase. As for the parent galaxolide stereoisomers 4 a, only one enantiomer of the silicon compounds (4RS,7SR)‐4 b, (4RS,7RS)‐4 b, rac‐9, and rac‐10, smelt upon enantioselective GC‐olfactometry, which according to the elution sequence is assumed to be also (4S)‐configured as in the case of the galaxolide stereoisomers. The disila‐analogues (4S,7R)‐4 b and (4S,7S)‐4 b were, however, about one order of magnitude less intense in terms of their odor threshold than their parent carbon compounds (4S,7R)‐4 a and (4S,7S)‐4 a. The introduction of a 7‐methylene group in disila‐galaxolide (4 b→rac‐9) improved the odor threshold by a factor of two. With the novel silicon‐containing galaxolide derivatives, the presumed hydrophobic bulk binding pocket of the corresponding musk receptor(s) could be characterized in more detail, which could be useful for the design of novel musk odorants with an improved environmental profile.
Formation and Evolution of Chain‐Propagating Species Upon Ethylene Polymerization with Neutral Salicylaldiminato Nickel(II) Catalysts
Authors: Soshnikov Igor E. , Semikolenova Nina V. , Zakharov Vladimir A. , Möller Heiko M. , Ölscher Franz , Osichow Anna , Göttker‐Schnettmann Inigo , Mecking Stefan , Talsi Evgenii P. , Bryliakov Konstantin P.
Published: July 2013

Formation of Ni–polymeryl propagating species upon the interaction of three salicylaldiminato nickel(II) complexes of the type [(N,O)Ni(CH3)(Py)] (where (N,O)=salicylaldimine ligands, Py=pyridine) with ethylene (C2H4/Ni=10:30) has been studied by 1H and 13C NMR spectroscopy. Typically, the ethylene/catalyst mixtures in [D8]toluene were stored for short periods of time at +60 °C to generate the [(N,O)Ni(polymeryl)] species, then quickly cooled, and the NMR measurements were conducted at −20 °C. At that temperature, the [(N,O)Ni(polymeryl)] species are stable for days; diffusion 1H NMR measurements provide an estimate of the average length of polymeryl chain (polymeryl=(C2H4)nH, n=6–18). At high ethylene consumptions, the [(N,O)Ni(polymeryl)] intermediates decline, releasing free polymer chains and yielding [(N,O)Ni(Et)(Py)] species, which also further decompose to form the ultimate catalyst degradation product, a paramagnetic [(N,O)2Ni(Py)] complex. In [(N,O)2Ni(Py)], the pyridine ligand is labile (with activation energy for its dissociation of (12.3±0.5) kcal mol−1, ΔH≠298=(11.7±0.5) kcal mol−1, ΔS≠298 =(−7±1) cal K−1 mol−1). Upon the addition of nonpolar solvent (pentane), the pyridine ligand is lost completely to yield the crystals of diamagnetic [(N,O)2Ni] complex. NMR spectroscopic analysis of the polyethylenes formed suggests that the evolution of chain‐propagating species ends up with formation of polyethylene with predominately internal and terminal vinylene groups rather than vinyl groups.