bluuebunny/crossref_metadata_2025_split huggingface dataset:
Community service or activism as an identity project for youth
Authors: Harré Niki 
Published: June 2007

AbstractThis article reviews the literature on community service and activism, particularly in youth, using the theoretical approach provided by an identity projects framework. This framework allows for an examination of the contextual and experiential factors that contribute to the emergence and maintenance of an identity project of service or activism. The contributors to project emergence may include: favourable social structures, collective crises, biographical availability, parental modelling, experiencing or witnessing injustice or suffering, inspiring stories, altruistic personality, religious values, and organisational affiliations. For many participants, these projects appear associated with intense experiences of belonging, stimulation, efficacy, and integrity. These experiences may be of great importance in reinforcing and expanding service or activism. © 2007 Wiley Periodicals, Inc. J Comm Psychol 35: 711–724, 2007.
Molecular properties of local anesthetics as predictors of affinity for nicotinic acetylcholine receptors
Authors: Pagán Oné R. , Sivaprakasam Kannan , Oswald Robert E. 
Published: June 2007

AbstractIn spinal anesthesia, the effects of local anesthetics (LAs) are not completely explained by sodium channel inhibition. Other targets include neuronal nicotinic acetylcholine receptors (nAChRs). LA affinities for theTorpedo californicanAChR were measured by inhibition of [3H]TCP binding and correlated with molecular volume, surface area, molecular weight, and log of the octanol‐water partition coefficients (P and D). To understand the molecular determinants important for interaction with the nAChR, ester and amide LAs were compared separately. Also, correlations with the aromatic/linker half and the hydrophilic half of the LA molecules were considered individually. The IC50s of the ester LAs correlated better with the molecular volume, surface area, molecular weight, and log P of the aromatic/linker half of the molecules; whereas the IC50s for amide LAs correlated better with the four parameters based on the hydrophilic half. These correlations were used to predict the IC50of various LAs (including several not studied here) and to compare these values with the published values. The predicted values of IC50correlated well with the published results both for neuronal and for electroplaque‐desensitized nAChR, suggesting that the results can be generalized to include neuronal nAChRs. © 2007 Wiley‐Liss, Inc.
VFR tourism: the importance of university students as hosts
Authors: Bischoff Eberhard E. , Koenig‐Lewis Nicole 
Published: June 2007

AbstractThe role of university students in attracting friends and relatives as visitors to their place of study is examined. A questionnaire survey conducted at a UK university is presented in the context of general UK tourism and the visits to friends and relatives (VFR) sector in particular. It is demonstrated that universities represent large, frequently underestimated, generators of VFR tourism and that significant differences exist between the friends and the relatives' components. The paper draws concrete conclusions about the marketing opportunities and argues that the students themselves represent the most effective target for promotion efforts. It also points out possibilities for turning day visits into overnight stays, particularly in the relatives' segment. Copyright © 2007 John Wiley & Sons, Ltd.
Prospective Screening in Liver Transplant Recipients by Panfungal PCR-ELISA for Early Diagnosis of Invasive Fungal Infections
Authors: Badiee Parisa , Kordbacheh Parivash , Alborzi Abdolvahab , Malekhoseini SeyedAli , Zeini Farideh , Mirhendi Hosein , Mahmoodi Mahmood 
Published: June 2007

Abstract
Invasive fungal infections after liver transplantation (LT) have resulted in high mortality and potentially fatal complications. This study was undertaken to determine the accuracy of the panfungal polymerase chain reaction enzyme link immunosorbent assay (PCR-ELISA) method in early diagnosis of invasive fungal infections in liver transplant recipients (LTRs). A total of 48 liver recipients (cadaver donors) were followed for fungal infections for a period of at least 6 months. All clinical samples were cultured and a direct microscopic examination was performed. Blood samples were cultured by bedside inoculation onto BACTEC medium. Whole blood specimens were collected prospectively once per week and were evaluated for any invasive fungal infections by panfungal PCR and PCR-ELISA. Among 48 transplant recipients between September 2004 and January 2006 (22 females, 28 males, mean age = 34.4 yr), 40 recipients (83.3%) had Candida colonization in different sites of their body before LT. In proven and probable recipients for panfungal PCR-ELISA, the sensitivity, specificity, and positive and negative predictive values were 83.3%, 91.7%, 76.9%, and 94.3%, respectively. By PCR assay, fungal infections were diagnosed in 10 recipients (20.8%). The mean interval time from transplantation to development of fungal infection was 61.4 days (range, 20-150 days) and time of infection in blood before any clinical signs was 7-70 days with mean of 21.4 days. The etiologic agents were Candida albicans (9 cases) and Aspergillus fumigatus (1 case). Use of PCR-ELISA in LTRs may not only improve the ability of early diagnosis of invasive fungal infections (IFIs) when positive results are obtained, but also would provide more confidence to exclude a diagnosis of IFIs when negative results are obtained. Liver Transpt 13:1011–1016, 2007. © 2007 AASLD.
Short-Term Induction Therapy with Anti-Thymocyte Globulin and Delayed Use of Calcineurin Inhibitors in Orthotopic Liver Transplantation
Authors: Soliman Thomas , Hetz Hubert , Burghuber Christoph , Györi Georg , Silberhumer Gerd , Steininger Rudolf , Mühlbacher Ferdinand , Berlakovich Gabriela A. 
Published: June 2007

Abstract
The appropriate time point for starting immunosuppressive treatment with calcineurin inhibitors after orthotopic liver transplantation (OLT) has been a subject of debate. The aim of the study was to analyze the effects of anti-thymocyte globulin (ATG) induction therapy on rejection, renal function, infection, tumor rate, and survival. We retrospectively analyzed 391 patients after OLT who had either received calcineurin inhibitors immediately after OLT (n = 129) or after an initial short-term Thymoglobulin induction therapy (n = 262). The 1-year acute rejection rate was 14.5% vs. 31.8% in favor of ATG (P = 0.0008). Rejection grades and the need for treatment also differed significantly (7.3% vs. 23.3%; P = 0.001). Serum creatinine at transplantation was similar in both groups (1.14 mg/dL vs.1.18 mg/dL; P = NS). Postoperative hemofiltration was less frequently seen after induction therapy (P < 0.05). Reduced renal function at 1 year was commonly observed, but serum creatinine (1.26 mg/dL vs. 1.37mg/dL; P = 0.015) and glomerular filtration rate (81 mL/min vs. 75 mL/min; P = 0.02) were far better in the ATG group. Undesired side effects occurred at a similar rate in both groups. Five-year patient survival was also similar in the 2 groups (70.1% and 74.3%; P > 0.05). Short-term ATG induction therapy with delayed administration of calcineurin inhibitors led to a more favorable rejection rate and an improved clinical course in case of a rejection episode. It has beneficial effects on renal function immediately after OLT as well as later, and no additional harmful effects. Liver Transpl 13:1039–1044, 2007. © 2007 AASLD.
Attitude of Hospital Personnel Faced with Living Liver Donation in a Spanish Center with a Living Donor Liver Transplant Program
Authors: Ríos A. , Ramírez P. , Rodríguez M. M. , Martínez L. , Rodríguez J. M. , Galindo P. J. , Parrilla P. 
Published: June 2007

Abstract
In Spain, despite its high rate of cadaveric donation, death while on the liver transplant waiting list is high. For this reason, living liver donation is being encouraged despite of the risk of morbidity for the donor. The objective of this study was to analyze attitudes toward living liver donation among hospital personnel in a hospital with a recently authorized living donor liver transplantation program. A random sample was taken and was stratified by type of service and job category (n = 1,262). Attitude was evaluated by means of a validated psychosocial questionnaire. The questionnaire was completed anonymously and was self-administered. Statistical analysis included the Student t test, the χ2 test, and logistical regression analysis. The questionnaire completion rate was 93% (n = 1,168). Only 15% (n = 170) of respondents were in favor of living liver donation if it were unrelated. An additional 65% (n = 766) were in favor if this donation, but only for relatives. Of the rest, 9% (n = 107) did not agree with living liver donation, and the remaining 11% (n = 125) were undecided. The variables related to this attitude were age (P = 0.044); job category (P = 0.002); type of service (according to whether it is related to organ donation and transplantation) (P = 0.044); participation in prosocial activities (P = 0.026); attitude toward cadaveric organ donation (P <0.001); attitude of a respondent's partner toward organ donation (P = 0.010); a respondent's belief that in the future, he or she may need a transplant (P < 0.001); and a willingness to receive a donated living liver organ if one were needed (P < 0.001). There is also a close relationship between attitude toward living kidney donation and living liver donation (P < 0.001). In the multivariate analysis, the only common independent variable from the bivariate analysis was a willingness to receive a living donor liver transplant if one were needed (odds ratio = 9.3). Attitude toward living liver donation among hospital personnel in a hospital with a solid organ transplant program is favorable and is affected by factors related to cadaveric donation, altruistic activity, and feelings of reciprocity. Physicians and the youngest hospital workers are those who are most in favor, which leads us to think that there is a promising future for living liver transplantation, which is essential given the cadaveric organ deficit and the high mortality rate while on the waiting list. Liver Transpl 13:1049–1056, 2007. © 2007 AASLD.
Synthesis and Properties of Hydrophilic Networks Based on Poly(ethylene glycol) and β‐Cyclodextrin
Authors: Cesteros Luis C. , Ramírez Camilo A. , Peciña Ainhoa , Katime Issa 
Published: June 2007

AbstractNew hydrophilic networks combining poly(ethylene glycol) (PEG) and β‐cyclodextrin (β‐CD) have been prepared. Both components are linked by reacting PEG chains previously end‐capped with isocyanate groups and β‐CD, forming urethane links. Networks of molar compositions (β‐CD/PEG) ranging from 1/4 to 1/14, and with four different molar masses (400, 600, 900, and 1 350 g · mol−1) of the end‐capped PEG precursor have been synthesized. The networks have good thermal stability and low glass transition temperatures. Crystallinity has only been detected for the two higher molar mass PEG precursors. The swelling properties of these hydrogels depend on the chain lengths of the PEG precursor and also on the temperatures.magnified image
Microstructure, Kinetics, and Transport in Oil‐in‐Water Microemulsion Polymerizations
Authors: O'Donnell Jennifer , Kaler Eric W. 
Published: June 2007

AbstractThe kinetics of microemulsion polymerization depend on the structure of the initial microemulsion and the transport of species between the aqueous domain, the micelles, and the polymer particles. The water solubility of the monomer and the proximity of the initial microemulsion composition to a phase boundary are key considerations for studying microemulsion polymerization kinetics and producing the desired products. Complications frequently arise in the synthesis of copolymers or the incorporation of controlled polymerization mechanisms because of the compartmentalized nature of microemulsion polymerizations.magnified image
Optimizing Melt‐Processing Conditions for the Preparation of iPP/Fumed Silica Nanocomposites: Morphology, Mechanical and Gas Permeability Properties
Authors: Vassiliou Alexandros , Bikiaris Dimitrios , Pavlidou Eleni 
Published: June 2007

AbstractA series of iPP/SiO2 nanocomposites, containing 1, 2.5, 5, 7.5, and 10 wt.‐% fumed silica nanoparticles, were prepared by melt mixing in a twin screw co‐rotating extruder. The effect of different extrusion parameters was evaluated. The size of aggregates increased with increase in SiO2 content and repetition of the mixing process improved the filler's dispersion. A similar effect was also exhibited by either increasing the rotor speed or the mixing temperature, with the latter being more pronounced at the ranges studied. The mechanical properties of the prepared nanocomposites were evaluated and various models used to explain the observed enhancements. However, only the three‐phase model could provide some correlation with the experimental results. All nanocomposites displayed lower permeability to gases.magnified image
A scalable multi‐level preconditioner for matrix‐free µ‐finite element analysis of human bone structures
Authors: Arbenz Peter , van Lenthe G. Harry , Mennel Uche , Müller Ralph , Sala Marzio 
Published: June 2007

AbstractThe recent advances in microarchitectural bone imaging disclose the possibility to assess both the apparent density and the trabecular microstructure of intact bones in a single measurement. Coupling these imaging possibilities with microstructural finite element (µFE) analysis offers a powerful tool to improve bone stiffness and strength assessment for individual fracture risk prediction.Many elements are needed to accurately represent the intricate microarchitectural structure of bone; hence, the resulting µFE models possess a very large number of degrees of freedom. In order to be solved quickly and reliably on state‐of‐the‐art parallel computers, the µFE analyses require advanced solution techniques. In this paper, we investigate the solution of the resulting systems of linear equations by the conjugate gradient algorithm, preconditioned by aggregation‐based multigrid methods. We introduce a variant of the preconditioner that does not need assembling the system matrix but uses element‐by‐element techniques to build the multilevel hierarchy. The preconditioner exploits the voxel approach that is common in bone structure analysis, and it has modest memory requirements, at the same time robust and scalable.Using the proposed methods, we have solved in 12min a model of trabecular bone composed of 247 734 272 elements, yielding a matrix with 1 178 736 360 rows, using 1024 CRAY XT3 processors. The ability to solve, for the first time, large biomedical problems with over 1 billion degrees of freedom on a routine basis will help us improve our understanding of the influence of densitometric, morphological, and loading factors in the etiology of osteoporotic fractures such as commonly experienced at the hip, spine, and wrist. Copyright © 2007 John Wiley & Sons, Ltd.
The use of folic acid antagonists and the risk of colorectal cancer
Authors: Coogan Patricia F. , Rosenberg Lynn 
Published: June 2007

AbstractPurposeSince folate is associated with a reduced risk of colorectal cancer, we hypothesized that folic acid antagonists might increase the risk. We used data from a population‐based case control study of medication use and colorectal cancer to evaluate the hypothesis.MethodsCase patients with adenocarcinoma of the colon or rectum were ascertained from participating hospitals in Massachusetts and the Massachusetts cancer registry (MCR) from January 1, 2001, through November 30, 2004. Age‐, sex‐, and precinct‐matched control subjects were chosen from Massachusetts town lists. Information on folic acid antagonist use and other relevant data were obtained from 1809 cases and 1809 matched controls by telephone interview and by a self‐administered dietary questionnaire. We used logistic regression models to estimate odds ratios among 1229 case patients and 1165 control subjects who provided satisfactory dietary information and did not have Crohn's disease or ulcerative colitis.ResultsThe odds ratio for colorectal cancer among regular users of folate‐containing supplements was 0.7 (95%CI 0.6–0.9). The odds ratio for regular use of folic acid antagonists was 1.3 (95%CI 0.9–1.9). Contrary to expectation, the odds ratio was reduced in the highest category of alcohol consumption (OR = 0.5, 95%CI 0.2–1.2). The odds ratio was higher among users of drugs that inhibit dihydrofolate reductase (OR = 1.6, 95%CI 0.9–2.8) than drugs that work through other mechanisms (OR = 1.2, 95%CI 0.7–1.9).ConclusionsOur data provide little support for the hypothesis that regular folic acid antagonist use increases the risk of colorectal cancer. However, there is a suggestion that dihydrofolate reductase inhibitors specifically may increase the risk. Copyright © 2007 John Wiley & Sons, Ltd.
NMR study and molecular dynamics simulations of optimized β‐hairpin fragments of protein G
Authors: Wei Yun , Huyghues‐Despointes Beatrice M. P. , Tsai Jerry , Scholtz J. Martin 
Published: June 2007

AbstractThe stability and structure of several β‐hairpin peptide variants derived from the C‐terminus of the B1 domain of protein G were investigated by a number of experimental and computational techniques. Our analysis shows that the structure and stability of this hairpin can be greatly affected by one or a few simple mutations. For example, removing an unfavorable charge near the N‐terminus of the peptide (Glu42 to Gln or Thr) or optimization of the N‐terminal charge–charge interactions (Gly41 to Lys) both stabilize the peptide, even in water. Furthermore, a simple replacement of a charged residue in the turn (Asp47 to Ala) changes the β‐turn conformation. Finally, we show that the effects of combining these single mutations are additive, suggesting that independent stabilizing interactions can be isolated and evaluated in a simple model system. Our results indicate that the structure and stability of this β‐hairpin peptide can be modulated in numerous ways and thus contributes toward a more complete understanding of this important model β‐hairpin as well as to the folding and stability of larger peptides and proteins. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Biological characterization and modes of action of temporins and bombinins H, multiple forms of short and mildly cationic anti‐microbial peptides from amphibian skin
Authors: Mangoni Maria Luisa , Marcellini H. G. Ludovica , Simmaco Maurizio 
Published: June 2007

AbstractGenetically encoded cationic anti‐microbial peptides (AMPs) are essential components of the ancient and non‐specific innate immune system, which is the principal defence mechanism of all species of life, with the primary role to kill infectious microorganisms. Amphibian skin is one of the richest natural sources of such molecules, which are produced by holocrine‐type dermal glands and released upon stimulation. This review highlights the attractive and unique structural/functional properties of temporins and bombinins H, two families of short and mildly cationic peptides, isolated from the skin of frogs belonging to Rana and Bombina genera, respectively. Beside improving our knowledge on the role of AMPs in the regulation of the innate immunity, the biological significance of the existence of multiple forms of a prototypic peptide sequence within the same organism and the implication of short peptides in the endotoxin neutralization, these two classes of AMPs can be also considered as valid candidates for the design of novel anti‐infective and anti‐sepsis drugs. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Electron energy loss spectroscopy of defects in diamond
Authors: Bangert U. , Barnes R. 
Published: June 2007

AbstractLocalised energy loss spectroscopy (EELS) is carried out in order to extract information of the effect of extended defects on the electronic bandstructure in diamond. EELS is performed in a dedicated cold field emission scanning transmission electron microscope (STEM), equipped with a Gatan Enfina spectrometer, at high energy dispersions, allowing energy resolutions (FWHM of the zero loss peak) of around 0.3 eV to be achieved without monochromation, thus enabling low EELS to be carried out in the bandgap regime of diamond at high brightness. Experiments are carried out on single crystal CVD and brown and colourless natural diamonds. Experimental details and evaluation of spectra are discussed, and the effects of diffraction contrast on the EEL intensity in the vicinity of defects are critically examined. A general characteristic of extended defects in CVD diamonds appears to be a relative increase of the loss signal below 6 eV and a distinct feature at 6–7 eV, concomitant with sp2‐bonds. It emerges that these states do not reside at cores of single dislocations, but near dislocation arrangements, in particular at nodes. A stark phenomenon in brown natural diamond is the omni‐present increase in the EEL intensity below 6 eV over that of colourless samples, suggesting the existence of spatially dispersed, non‐dislocation related centres, with energies throughout the bandgap. Recent theoretical and experimental investigations have revealed strong links with vacancy clusters. In order to further support the vacancy cluster hypothesis high resolution electron transmission microscopy (HR TEM) imaging in combination with vacancy clusters simulations at high defocus values is performed. The simulations predict characteristic small‐scale contrast, which can be experimentally observed in brown, but not in colourless diamond. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth, morphology, and structural properties of group‐III‐nitride nanocolumns and nanodisks
Authors: Calleja E. , Ristić J. , Fernández‐Garrido S. , Cerutti L. , Sánchez‐García M. A. , Grandal J. , Trampert A. , Jahn U. , Sánchez G. , Griol A. , Sánchez B. 
Published: June 2007

AbstractThe growth conditions to achieve group‐III‐nitride nanocolumns and nanocolumnar heterostructures by plasma‐assisted molecular beam epitaxy are studied. The evolution of the nanocolumnar morphology with the growth conditions is determined for (Ga,Al)N and (In,Ga)N nanocolumns. The mechanisms behind the nanocolumnar growth under high N‐rich conditions are clarified in the sense that no seeding or catalysts are required, as it is the case in the vapour‐liquid‐solid model that applies to most nanocolumns grown by metal organic chemical vapour deposition, either with group‐III nitrides, II–VI or III–V compounds. Some examples of nanocolumnar heterostructures are given, like quantum disks and cylindrical nanocavities. Preliminary results on the growth of arrays of ordered GaN nanocolumns are reported. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)