bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cooperative interaction of n‐butylammonium ion with 1,3‐alternate tetrapropoxycalix [4]arene: NMR and theoretical study
Authors: Kříž Jaroslav , Dybal Jiří , Budka Jan , Makrlík Emanuel 
Published: February 2008

AbstractThe interaction of 1,3‐alternate tetrapropoxycalix[4]arene (1) with n‐butylammonium ion (2) in CD2Cl2 was examined using 1H, 13C and 14N NMR spectroscopy and DFT (density functional theory) calculations. NMR shows that 1 forms with 2 an equimolecular hydrogen‐bonded complex with the equilibrium constant 5.91 × 103 l/mol at 296 K. The structure of the complex can be shown to be asymmetric at 203 K, with 2 interacting by hydrogen bonds with the two ethereal oxygen atoms of one half of 1 and with the π system of the other half, but is rapidly averaged to an apparent C4h symmetry by chemical exchange at higher temperatures. Using two related but independent techniques based on transverse and rotating‐frame proton relaxation, it is shown that only an intermolecular exchange of 2 between the bound and free states takes place, in contrast to previously studied interaction of 1 with H3O+. Its correlation time is 0.169 ms. It is shown by DFT calculations that such swift exchange is not possible without a cooperative interaction of both 2 and 1 with several molecules of water present. Similarities and contrasts between the exchange processes of 2 and H3O+ bound to 1 are discussed, in particular with respect to the apparent quantum tunneling of the latter inside the molecule of the complex. Copyright © 2008 John Wiley & Sons, Ltd.
Three new phenolic glycosides from the caulis of Millettia speciosa
Authors: Yin Ting , Tu Guangzhong , Zhang Qingying , Wang Bin , Zhao Yuying 
Published: February 2008

AbstractThree new phenolic glycosides, millettiaspecosides AC (1–3), were isolated from the caulis of Millettia speciosa along with three known phenolic glycosides, khaephuoside B (4), seguinoside K (5), albibrissinoside B (6). Their structures were established by spectroscopic methods. The spectral analysis permitted correct assignments for 1H and 13C NMR data of compounds 4 and 5. Copyright © 2008 John Wiley & Sons, Ltd.
Ionic liquids as novel and green media for clean synthesis of soluble aromatic‐aliphatic poly(amide‐ester)s containing hydroxynaphthalene urazole moiety
Authors: Mallakpour Shadpour , Rafiee Zahra 
Published: February 2008

AbstractIonic liquids (IL)s are very attractive and environmentally acceptable solvents. They can be used as green media for a number of chemical processes. In this investigation, for the advancement of ecological safety and improvement of technological ability of this process, room temperature ionic liquids (RTIL)s and quaternary ammonium salt, tetrabutylammonium bromide (TBAB) have been used both as an environmentally benign solvent and catalyst for the polycondensation 4‐(3‐hydroxynaphthalene)‐1,2,4‐triazolidine‐3,5‐dione (3HNTD) with aliphatic diacid chlorides, eliminating the need for a volatile organic solvent (VOS) and additional catalyst. The reaction of monomer 3HNTD with acetyl chloride was performed in N,N‐dimethylacetamide solution at different molar ratios, and the resulting mono‐, di‐, and trisubstituted derivatives were obtained in high yields and were finally used as models for polymerization reactions. The effects of various reaction parameters, such as the nature of the ILs, the amount of ILs, the reaction temperature, and the reaction time, on the yields and inherent viscosities of the resulting poly(amide‐ester)s (PAE)s were studied. Polycondensation reactions successfully proceeded in IL without any additional extra components, such as triethylamine or pyridine, which are used in similar reactions in organic solvents. Therefore, ILs can act both as solvent and catalyst. In addition to the solubility test, inherent viscosity as a measure of molecular weight was determined. PAEs were obtained in high yields with inherent viscosities ranging from 0.18 to 0.34 dl g−1. This method was also compared with conventional method for the synthesis of PAEs. Fluorimetric studies of the model compound as well as polymers were performed. Copyright © 2008 John Wiley & Sons, Ltd.
Practice development in substance misuse services: changing the patient experience of services
Authors: Sims John , Kristian Marc R , Pritchard Karen , Jones Linda 
Published: February 2008

AbstractThis article is an honest account of the practice development unit (PDU) journey undertaken by a substance misuse service in North‐West Wales. The sustainability of such initiatives is also examined and the positive effect upon the workforce that the PDU journey can achieve is also discussed. Resistance to change within the workforce and from the employing organization is also considered, and the innovative responses to these hurdles. Inviting service users to become actively involved in the development of services can be a powerful force for sustainable changes. The involvement of individuals who have been service users is a way of contributing to the process of developing services in a creative and innovative way that strives to ensure appropriateness and quality. The issues around vulnerability and the responsibilities placed upon service providers to minimize pressure on patients are discussed. The article also identifies ways of harnessing this positive energy and the utilization of valued and varied personal experiences of clients, both of which result in empowerment of clients. The aim of the article was to provide insights into all of these aspects of the PDU journey in order to offer support for others about to embark upon it. Copyright © 2008 John Wiley & Sons, Ltd.
Living cationic polymerization of α‐methyl vinyl ethers using SnCl4
Authors: Yonezumi Motomasa , Takaku Reiko , Kanaoka Shokyoku , Aoshima Sadahito 
Published: February 2008

AbstractCationic polymerization of α‐methyl vinyl ethers was examined using an IBEA‐Et1.5AlCl1.5/SnCl4 initiating system in toluene in the presence of ethyl acetate at 0 ∼ −78 °C. 2‐Ethylhexyl 2‐propenyl ether (EHPE) had a higher reactivity, compared to corresponding vinyl ethers. But the resulting polymers had low molecular weights at 0 or −50 °C. In contrast, the polymerization of EHPE at −78 °C almost quantitatively proceeded, and the number‐average molecular weight (Mn) of the obtained polymers increased in direct proportion to the EHPE conversion with quite narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight ≤ 1.05). In monomer‐addition experiments, the Mn of the polymers shifted higher with low polydispersity as the polymerization proceeded, indicative of living polymerization. In the polymerization of methyl 2‐propenyl ether (MPE), the living‐like propagation also occurred under the reaction conditions similar to those for EHPE, but the elimination of the pendant methoxy groups was observed. The introduction of a more stable terminal group, quenched with sodium diethyl malonate, suppressed this decomposition, and the living polymerization proceeded. The glass transition temperature of the obtained poly(MPE) was 34 °C, which is much higher than that of the corresponding poly(vinyl ether). This poly(MPE) had solubility characteristics that differed from those of poly(vinyl ethers). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2202–2211, 2008
Horseradish peroxidase immobilized in macroporous hydrogel for acrylamide polymerization
Authors: Zhao Qian , Sun Jianzhong , Ren Hua , Zhou Qiyun , Lin Qincai 
Published: February 2008

AbstractThermosensitive hydrogel made up of poly(N‐isopropylacrylamide) (PNIPA)‐chitosan semi‐interpenetrating network (semi‐IPN) with ultrarapid responding rate was synthesized. Horseradish peroxidase (HRP) was then immobilized on this hydrogel that acted as an enzyme‐carrier by glutaraldehyde bridge. Polymerization of acrylamide was initiated by a redox system (hydrogen peroxide/acetylacetone (Acac)) and was catalyzed by the immobilized enzyme at room temperature. The attention was focused on the properties of the carrier‐enzyme systems. The hydrogel was proofed to be macroporous by environmental scanning electron microscope images. Swelling properties of the hydrogel such as swelling ratio and deswelling–reswelling kinetics were measured. The properties of the immobilized enzyme such as enzyme activity, storage stability, and thermostability were also studied. The immobilized enzyme could be used repeatedly. Gel permeation chromatography measurement of the resulted polyacrylamide (PAAm) showed that the molecular weight reduced as the repeated times of the immobilized enzyme catalysis increased. In conclusion, the macroporous hydrogel would be a suitable enzyme carrier for practical applications in future. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2222–2232, 2008
Proteomics in rheumatology: The beginning of a fairy tale?
Authors: Lambrecht Stijn , Tilleman Kelly , Elewaut Dirk , Deforce Dieter 
Published: February 2008

AbstractOne of the major challenges in proteome research is to translate its applications to the setting of human diseases. Proteomics in rheumatology is an area with marked potential including applications ranging from diagnostics, over therapeutic monitoring to discovery of new potential therapeutic targets. Biomarkers will be essential to discriminate between clinical similar rheumatic diseases, to monitor disease‐states or to install the best appropriate therapy. Especially in the field of rheumatology, analysis of specific genes and/or their expression products by pharmacogenetics/‐genomics or pharmacoproteomics could be necessary to enable an effective, patient‐tailored therapy. In rheumatology, direct examination of proteins may be of utmost importance, as it is already known that PTMs, such as citrullination of proteins or peptides, may be involved in certain rheumatic diseases. The discovery and validation of antibodies directed against citrullinated proteins/peptides in rheumatic diseases using proteome analysis approaches has been described. Gel‐free methods, SELDI‐approaches and classic 2‐DE approaches have been deployed on body fluids as well as on target tissues in different rheumatic diseases. Proteomics in rheumatology is on the rise and pilot studies have indicated that the application of proteomics‐based technologies in rheumatic diseases appears to be an exciting example of translational research.
Purely quadratic dispersion of surface plasmon in Ag/Ni(111): the influence of electron confinement
Authors: Politano A. , Agostino R. G. , Colavita E. , Formoso V. , Chiarello G. 
Published: February 2008

AbstractSurface plasmon dispersion in nanoscale thin Ag films deposited onto the Ni(111) surface was investigated by angle‐resolved electron energy loss spectroscopy. We found that the dispersion curve contains only the quadratic term. The vanishing of the linear term was ascribed to the presence in the film of Ag 5sp‐related quantum well states. Screening effects enhanced by electron confinement in Ag quantum well states push the position of the centroid of the induced charge of the surface plasmon less inside the interface compared to other Ag systems, rendering null the linear coefficient of the dispersion curve. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamic response of stream temperatures to boundary and inflow perturbation due to reservoir operations
Authors: Khangaonkar Tarang , Yang Zhaoqing 
Published: February 2008

AbstractDams and reservoir operations modify natural stream behaviour and affect the downstream characteristics such as mean temperatures and diurnal temperature amplitudes. Managing phase effects due to reservoir operation and the associated amplification of daily maximum temperatures in the downstream reaches remains a challenge. An analytical approach derived from a one‐dimensional heat advection and dispersion equation with surface heating in the form of equilibrium temperature was developed to examine the potential for restoration of natural stream temperatures. The analytical model was validated with observed temperature data collected in the Clackamas River, Oregon, and was used to highlight key downstream temperature behaviour characteristics. Mean stream temperatures below the dam are relatively stable and upon deviating from natural stream mean temperatures, return asymptotically to their natural state. In contrast, the amplitudes of daily temperature variation are highly sensitive to the phase differences induced by the dam and could nearly double in natural amplitude within the first 24 h. The analysis showed that restoring average stream temperatures to natural levels through structural and operational modifications at the dam may not be sufficient as phase‐induced temperatures maximums would continue to persist. Copyright © 2008 John Wiley & Sons, Ltd.
Nanoscopic distribution of potential and topography on Si (111) surface having 1 × 1 and 7 × 7 structures with and without scratching
Authors: Nakayama Keiji , Shiota Tadashi 
Published: February 2008

AbstractThe distribution of potential has been investigated for Si (111) surfaces having 1 × 1 and 7 × 7 structures with and without scratching. It was measured using scanning Kelvin probe force microscopy combined with non‐contact atomic force microscopy in an ultrahigh vacuum. Potential images display nanoscopic structures related to surface atomic structures, so we can distinguish 1 × 1 and 7 × 7 structures and scratched surfaces even when the topographical difference is negligible. Oxygen adsorption greatly changes the surface potential and the extent of the difference depends on the surface atomic structure. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation of glutamine films on silicon substrates
Authors: Garcia Irene T. S. , Porto Fabiane G. da S. , do Amaral Queila D. F. , Carreño Neftalí L. V. , Martins Márcio M. , Wallau Martin 
Published: February 2008

AbstractAmino acids and polypeptides thin films, pure or attached to polymers, present large application as sensors and biosensors. The interactions between such films and the supports, their sensorial properties, as well as the development of techniques to produce thin regular films, are still challenges in the area. In this work, we present the preparation of L‐glutamine thin films on silicon substrates, the factors that determine amino acid/silicon substrate interaction, and the morphology of the films. For this purpose, a 24 factorial design is used, taking into account the effects of the solvent system, the glutamine concentration, the temperature, as well as the pretreatment of the substrate surface. The contact angles between a drop of glutamine solution and the silicon substrate were taken for the preliminary evaluation of the affinity between the amino acid and the substrate. The results have shown six promising experimental combinations with oxidized silicon as substrate to improve the solution/substrate interaction. Three of these promising conditions involved aqueous solution of L‐glutamine and three alkalis solution. The obtained films were characterized by scanning electron microscopy (SEM), Rutherford backscattering (RBS), and Fourier transform infrared (FTIR) spectroscopy. The selected experimental conditions permitted to prepare a variety of films with L‐glutamine, like small crystals, lamellas, needles, and smoothed regular films. The systems prepared in presence of alkalis solution yielded regular and smooth films. Copyright © 2008 John Wiley & Sons, Ltd.
Assessing influence for pharmaceutical data in zero‐inflated generalized Poisson mixed models
Authors: Xie Feng‐Chang , Wei Bo‐Cheng , Lin Jin‐Guan 
Published: February 2008

AbstractFor clustered count data with excess zeros where the observations are either over‐dispersed or under‐dispersed, the zero‐inflated generalized Poisson mixed (ZIGPM) regression model may be appropriate, in which the baseline discrete distribution is a generalized Poisson distribution, which is a natural extension of standard Poisson distribution. Motivated by one data set drawn from a pharmaceutical study, influence diagnostics for ZIGPM models based on case‐deletion and local influence analysis are developed in this work. The one‐step approximations of the estimates under case‐deletion model and some case‐deletion measures are given. Meanwhile, local influence measures are obtained under various perturbations of the observed data or model assumptions. Results from a pharmaceutical study illustrate the usefulness of the diagnostic statistics. Copyright © 2008 John Wiley & Sons, Ltd.
Investigation of voltage sag impact on wind turbine tower vibrations
Authors: Fadaeinedjad R. , Moschopoulos G. , Moallem M. 
Published: February 2008

AbstractTo study the effect of voltage sag on the mechanical vibration of a wind turbine structure, a detailed model that considers the combined electrical, mechanical and aerodynamic aspects of the wind turbine must be used. A drawback of many previously published works in the area of wind turbine simulation is that they study either a very simple mechanical model with a detailed electrical model or vice versa. Therefore, the interactions between electrical and mechanical components are not accurately taken into account. In this paper, three simulation programs—TurbSim, FAST and Simulink—are used to model the wind, mechanical and electrical parts of a wind turbine and its controllers in detail. Simulation results obtained from the model are used to observe the interaction of all three factors affecting the operation of a wind turbine system. The focus of the paper is on the effect of the voltage sag on tower vibration, considering different power system characteristics (i.e. short circuit level and X/R ratio), mechanical parameter (i.e. mechanical tower damping) and wind turbine operating conditions. Copyright © 2008 John Wiley & Sons, Ltd.
Advancing global citizens: Afterschool and out‐of‐school time as common ground for civil society
Authors: Schneider‐Muñoz Andrew , Politz Bonnie 
Published: February 2008

AbstractThe key importance of after‐school and out‐of‐school time in a democratic society is the experience of activities and programs providing a common ground that extends the play of childhood into leadership opportunities for youthful learning and exploration of the world. The authors hypothesize that by focusing civic attention on the developmental quality of these out‐of‐school settings and time frames, objectives will also be better understood and reliable.
Summer learning programs and student success in the global economy
Authors: Smink Jeffrey D. 
Published: February 2008

AbstractIn the United States and around the rest of the world, there is a renewed focus on ensuring that schools are providing students with the skills necessary to compete in the global economy. High‐quality summer learning programs are an ideal vehicle to help students gain content knowledge and develop innovative skills: they provide time for individual exploration and hands‐on, experiential opportunities that can instill a lifelong love of learning that carries into the classroom and the workforce.
Quality out‐of‐school care in Aotearoa/New Zealand
Authors: Walter Christine 
Published: February 2008

AbstractThe out‐of‐school‐care sector, a reasonably unregulated industry, has grown quickly despite minimal government investment in comparison to early childhood care. In 2006, the New Zealand government released a draft five‐year strategic plan committing an extra $17.4 million per year to this area. This article examines the impact on providers, recipients, and quality standards with the influx of resources and attention.
Youth voices thrive in Facilitating Leadership in Youth
Authors: Detzler Mindy Larson , Van Liew Charise , Dorward Lisa Granquist , Jenkins Roneka , Teslicko David 
Published: February 2008

AbstractIn inner‐city Washington, D.C., lives a generation of young people for whom violence, discrimination, and poverty are a daily reality. Out‐of‐school‐time programming by Facilitating Leadership in Youth provides youth with comprehensive support and services, trusting relationships, and gradually increasing leadership opportunities to elicit positive community change.
Invariant based programming: basic approach and teaching experiences
Authors: Back Ralph-Johan 
Published: February 2008

Abstract

Program verification is usually done by adding specifications and invariants to the program and then proving that the verification conditions are all true. This makes program verification an alternative to or a complement to testing. We describe here another approach to program construction, which we refer to as
invariant based programming
, where we start by formulating the specifications and the internal loop invariants for the program, before we write the program code itself. The correctness of the code is then easy to check at the same time as one is constructing it. In this approach, program verification becomes a complement to coding rather than to testing. The purpose is to produce programs and software that are correct by construction. We present a new kind of diagrams,
nested invariant diagrams
, where program specifications and invariants (rather than the control) provide the main organizing structure. Nesting of invariants provide an extension hierarchy that allows us to express the invariants in a very compact manner. We have studied the feasibility of formulating specifications and loop invariants before the code itself has been written in a number of case studies. Our experience is that a systematic use of figures, in combination with a rough idea of the intended behavior of the algorithm, makes it rather straightforward to formulate the invariants needed for the program, to construct the code around these invariants and to check that the resulting program is indeed correct. We describe our experiences from using invariant based programming in practice, both from teaching programmers how to construct programs that they prove correct themselves, and from teaching invariant based programming for CS students in class.
Thoracic Aortic Aneurysm: Reading ttable he Enemy’s Playbook
Authors: Elefteriades John A. 
Published: February 2008

AbstractBackgroundThe purpose of the present study was to use the clinical database at the Yale University Center for Thoracic Aortic Disease to shed light on the pathophysiology of thoracic aortic aneurysm (TAA), the clinical behavior of thoracic aortic aneurysm, and the optimal clinical management.Materials and MethodsThe Yale database contains information on 3,000 patients with thoracic aortic aneurysm, with 9,000 patient‐years of follow‐up and 9,000 imaging studies. Advanced statistical techniques were applied to this information.ResultsAnalysis provided the following observations: (1) TAA is a genetic disease with a predominantly autosomal dominant mode of inheritance, (2) matrix metalloproteinase (MMP) enzymes are activated in the pathogenesis of TAA, (3) wall tension in TAA approaches the tensile limits of aortic tissue at a diameter of 6 cm, (4) by the time a TAA reaches a clinical diameter of 6 cm, 34% of affected patients have suffered dissection or rupture, (5) extreme physical exertion or severe emotion often precipitate acute dissection, and (6) single nucleotide polymorphisms (SNPs) are being identified which predispose a patient to TAA.ConclusionsThe “playbook” of TAA is gradually being read, with the help of scientific investigations, positioning practitioners to combat this lethal disease more effectively than ever before.