bluuebunny/crossref_metadata_2025 huggingface dataset:
Communication in nursing: the theory‐practice relationship
Authors: Brereton Margaret Louise
Published: May 2006

The theory‐practice relationship and the use of communication and interpersonal skills in nursing have been recurrently identified as issues causing concern Four research questions form the basis of this small‐scale exploratory study investigating the views of nurse teachers, mentors and students into the theory‐practice relationship with regard to the communication and interpersonal skills theme of the Project 2000 common foundation programme (CFP) for British nursing students Hierarchical focusing, involving individual interviews with teachers and mentors and small‐group interviews with students, was undertaken Volunteer sampling was used Qualitative data analysis was undertaken using content analysis Results are summarized with regard to each main research question There was little consensus of opinion amongst participants, and the nature of the theory‐practice relationship with regard to the communication and interpersonal skills theme for the CFP remains unclear However, there was agreement that communication is fundamental to nursing and that the socialization process strongly influences the development of communication and interpersonal skills There appears to be a reliance on mentors to assess student progress and determine whether they have knowledge underpinning practice Classroom teaching was recognized as idealistic but the divisions in participants' opinions led to difficulty in determining whether a theory‐practice gap actually exists The main influences on the theory‐practice relationship were the mentor's knowledge of the curriculum and mentoring system, the short amount of time spent in each placement and relationships between teachers, mentors and students Recommendations include the need to ensure the reliability and validity of progressive assessment
Assessing the quality of the working life of nurse educators in Finland: perceptions of nurse educators and their spouses
Authors: Harri Marja
Published: May 2006

As part of a broader descriptive study of nurse educators' well‐being at work in Finland, the quality of working life was assessed by the nurse educators themselves and by their spouses (or another adult living with them) Data were analysed from 477 (68% of 706) educators from 25 institutes throughout Finland and from 409 (58% of 706) spouses Nurse educators evaluated their working life as being good Background factors that improved one or several features of working life were young age, being married, permanent employment in a small institute in the countryside, and highschool education Lack of freedom to choose the teaching field and tasks at work reduced the quality of working life Nurse educators estimated that they did an average of 9 6 hours overtime a week, according to their spouses the figure was 12 7 hours More than moderate amounts of negative stress, derived mainly from work, were reported Interactions with people at work and the support obtained for their work were generally judged to be good Participants reported that they were not very satisfied with relationships with college directors, while they were, generally, satisfied with relationships with students The spouses estimated nurse educators' working life more negatively than did the educators themselves, with the exception of the balance between work and leisure time, which both groups estimated similarly
Nurse teacher's clinical work: a survey report
Authors: Clifford Collette
Published: May 2006

This paper reports on the results of a survey of nurse teachers in four colleges of nursing in England (n = 126) Data were collected using a questionnaire survey In this survey a five‐point Likert scale was developed from an earlier study, to explore nurse teachers' perception of their clinical role The findings indicate that a number of factors may be influential in the way in which nurse teachers approach their clinical activity This includes personal factors such as age, educational grade and the length of time spent working in nurse education Organizational factors also appear to make a difference in the teacher who worked in an organizational model which ensured a smaller number of link ward areas were more likely to exhibit a positive orientation towards clinical work Factor analysis of the clinical scale resulted in loading of items relating to confidence in clinical role, preparation for the role, influence in clinical area and supervision of students in clinical areas The implications of these findings are discussed
A history of nursing: a history of caring?
Authors: Maggs Christopher
Published: May 2006

The history of nursing is, itself, a fit subject for research It is unclear what would constitute history in this case, its time frame or its methodology It is also the case that the purpose of history needs exploration, since it can meet many goals, including the goal of professionalization This paper explores these issues in some detail, using examples from the literature in the history of nursing It explores historical inquiry and purpose and the problems of sources The paper also addresses the relationship between the history of nursing and nursing theory and questions whether existing historical scholarship is integrated with or is outwith mainstream nursing theory The paper questions the relevance of the history of nursing and suggests that the history of caring may offer one way through history to nursing theory
A nursing perspective on the interrelationships between theory, research and practice
Authors: Pryjmachuk Steven
Published: May 2006

This paper is concerned with the interrelationships between the three concepts of theory, research and practice In the course of discussing the interrelationships between these concepts, research is identified as the link between theory and practice on both a formal (explicit) and informal (tacit) level The role of formal and informal research in the development of nursing expertise is also given some consideration
Processes in the creation and diffusion of nursing knowledge: an examination of the developing concept of family‐centred care
Authors: Bradley Susan F
Published: May 2006

The creation of a knowledge base to underpin and direct nursing practice has been the pursuit of nurse academics, educationists and practitioners over recent decades Much of this work has concerned the explication of major theories of nursing, whilst some has sought to elucidate specific areas of knowledge This paper outlines processes of creation and diffusion, considering the influence of factors from both within and without the nursing profession on the epistemology of its knowledge base An examination of the developing concept of family‐centred care is utilized to illustrate the convolutionary process of knowledge creation
Gender differences in career progress in nursing: towards a non‐essentialist structural theory
Authors: Ratcliffe Phillip
Published: May 2006

This paper briefly reviews the literature on gender differences in career progress in nursing It argues that current explanations for these differences are essentialist in nature Aspects of the literature on the labour market and neo‐Weberian closure theories are critically reviewed and a synthesis of these two domains is proposed The paper argues that this synthesis can provide a non‐essentialist explanatory framework for gender differences in career progress and provides a foundation for ongoing empirical work The exercise points to the importance of geographical mobility and its use as an exclusionary criterion in career progress In the context of the nursing labour market this process may serve to maintain structural gender bias in professional nursing
The role of nursing journals in the advancement of professional nursing*
Authors: Smith James P
Published: May 2006

From modest developments of‘popular’nursing journals many years ago, there has been a prolific growth in the numbers of nursing journals published each year This growth is particularly noteworthy in the increase in the numbers of specialist interest and scholarly nursing journals The different types of journals have also tended to influence each other's contents, as well as the contents of nursing textbooks Over the years, nurses themselves have emerged as the main contributors to the journals Increasingly the focus of all the journals has been on nursing practice — and the factors associated with professional practice and the professional education and development of nurses Whilst it is conceded that it is difficult to demonstrate that nursing journals have made a direct impact on care, some indirect impact can be claimed This claim is based, among other things, on the contribution of nursing journals to the development of nursing as a profession, their contribution to the individual development of professional nurses, and their contribution to the documentation of the body of nursing knowledge
Making sense of action research through the use of a typology
Authors: Hart Elizabeth , Bond Meg
Published: May 2006

Commenting on earlier work in the Journal of Advanced Nursing on action research, this paper takes up the theme of definition and approach and presents an original action research typology Three key criteria of action research ‐‘reeducation’,‘problem focus’, and‘improvement and involvement’— are related to four broad types of action research‘experimental’,‘organizational’,‘professionalizing’and‘empowering’The typology is of general relevance not only to action researchers but to any project concerned to resolve problems and bring about improvements in practice, including evaluation research Following discussion of the typology, it is used to analyse three different action research projects, including one conducted by the authors in collaboration with a project team It is shown that each of these projects, which are all concerned in some way to improve standards of nursing care in hospitals, contains elements of different types which may at times be in conflict The ability to recognize this and to be explicit about the different types may assist action researchers in selecting an appropriate approach and in anticipating problems which may arise during the course of a project's life
A protein Ser/Thr kinase cascade negatively regulates the DNA‐binding activity of MrpC, a smaller form of which may be necessary for the Myxococcus xanthus development
Authors: Nariya Hirofumi , Inouye Sumiko
Published: May 2006

The developmental process of Myxococcus xanthus is achieved by the expression of a specific set of genes under the influence of developmental signals. MrpC is a member of the CRP family of transcription regulators, essential for fruA expression during development. The Pkn8‐Pkn14 protein kinase cascade negatively regulates mrpC expression (H. Nariya and S. Inouye, 2005. Mol Microbiol 58: 367–379). Elevated levels of mrpC in pkn8 and pkn14 deletion strains (Δpkn8 and Δpkn14) induce untimely FruA production during vegetative growth resulting in significantly faster fruiting body development. mrpC expression is presumably activated by MrpA and MrpB which belong to a two‐component His‐Asp phosphorelay system and is proposed to require MrpC on the basis of the genetic analysis. In the present study, we demonstrate that MrpC binds to at least eight sites in the upstream region of its promoter. Based on analysis of MrpC binding sites in the mrpC and fruA promoter regions, there are two types of MrpC‐specific binding sequences. Importantly, MrpC‐binding activity was greatly reduced upon its phosphorylation by Pkn14. MrpC2, a transcription activator for fruA expression, lacks the N‐terminal 25 residues of MrpC and exhibited four‐ and eightfold greater binding activity to the mrpC and fruA promoter regions respectively. Pkn14 was not able to phosphorylate MrpC2 and phosphorylates MrpC at Thr residue(s), thus Thr‐21 and/or Thr‐22 is (are) the likely site(s) of MrpC phosphorylation. MrpC2 was not detected in a lonD mutant in which fruA expression is low. Thus, the LonD protease essential for development may play an important role for the activation of MrpC‐binding activity through its proteolytic processing to MrpC2, required for developmental progression. MrpC2, only detectable during development in DZF1, was present at high levels during vegetative growth in Δpkn8 and Δpkn14, thus MrpC phosphorylation may inhibit its proteolytic processing. Based on these results, we propose a mechanism by which two transcription factors essential to development, MrpC and FruA, are regulated during the M. xanthus life cycle.
The use of oral cyclosporin to treat feline dermatoses: a retrospective analysis of 23 cases
Authors: Vercelli A. , Raviri G. , Cornegliani L.
Published: May 2006

Limited information is available regarding the use of cyclosporin A (CsA) for the treatment of feline dermatoses. The aim of this retrospective study was therefore to describe the efficacy of CsA for the therapy of eosinophilic granuloma (EG), eosinophilic plaque, indolent ulcer, linear granulomas, idiopathic pruritus and stomatitis. A computer search for feline dermatological cases treated with CsA between 1999 and 2004 was performed. Based on history, clinical signs and laboratory diagnostic tests, it was then possible to divide cases into three groups and to select 23 cats. Seven cats had one or more of the following conditions: EG, eosinophilic plaque, indolent ulcer and/or linear granuloma (group A); eight cats had idiopathic pruritus (group B) and eight cats had plasmacytic stomatitis (group C). Doses ranged from 5.8 to 13.3 mg kg−1oral CsA. All cats were monitored, with complete serum blood analysis and physical examination, monthly for a minimum of 6 months. Response to therapy was scored (severity of lesions and pruritus) with a 0–10 visual analogue scale at each visit (day 0, day, 30, day 60, day 90). All cats in groups A and B were cured and were maintained on alternate day therapy. In group C, 4/8 patients went into remission, while remaining cats have a fair to good improvement. Routine haematological and biochemical examination failed to reveal abnormalities related to CsA administration.
MORAL CONSIDERATIONS IN BODY DONATION FOR SCIENTIFIC RESEARCH: A UNIQUE LOOK AT THE UNIVERSITY OF TENNESSEE’S ANTHROPOLOGICAL RESEARCH FACILITY1
Authors: CHRISTENSEN ANGI M.
Published: May 2006

This paper discusses keys to the moral procurement, treatment and disposition of remains used for scientific research, specifically those donated to the University of Tennessee’s Anthropological Research Facility (ARF). The ARF is an outdoor laboratory dedicated to better understanding the fate of human remains in forensic contexts, and focuses its research on decomposition, time since death estimates, body location and recovery techniques, and skeletal analysis. Historically, many donations were unclaimed bodies received from medical examiners (although it will be shown that this trend is changing), and it has been argued that the use of unclaimed bodies for medical or scientific purposes is a violation of autonomy since no consent was given by the individual. It is argued here, however, that the domain of autonomous choice extends to one’s own corpse only insofar as expressed wishes are made known prior to one’s death, and that in the absence of expressed intent toward final disposition, it is acceptable for institutions to receive donations from medical examiners or family members. This paper also discusses other philosophical issues related to donation, consent and autonomy, and the forensic benefits of research conducted at the Anthropological Research Facility.
DO HISTORIANS NEED PHILOSOPHY?
Authors: Martin Raymond
Published: May 2006

The Logic of History: Putting Postmodernism in Perspective. By C. Behan McCullagh
β-Receptor Response to Noradrenaline in Cluster Headache. A Study of Adipose Tissue Lipolysis
Authors: Meyer E Laudon , Waldenlind E , Marcus C
Published: May 2006

We have previously shown decreased lipolysis in both phases of cluster headache (CH), as an indication of a sympathetic dysregulation. Reduced lipolysis could be a result of diminished β-receptor sensitivity in adipose tissue. The aim of this study was to measure the lipolytic response to noradrenaline in 10 CH patients in remission and in 10 healthy subjects, to estimate β-receptor function. Microdialysis technique was used to measure the increase of glycerol, the end-product of lipolysis, during infusion of noradrenaline into the adipose tissue. Noradrenaline infusion resulted in a distinct elevation of glycerol. The average glycerol increase was significantly higher in CH patients (121± ± 48) than in healthy subjects (77± ± 41) ( P < 0.05), which indicates increased β-receptor response to noradrenaline in CH patients in remission. This may be due to up-regulated β-receptor sensitivity, secondary to reduced sympathetic outflow and a primary autonomic disturbance in CH.
Self‐Reported Competency of Public Health Nurses and Faculty in Illinois
Authors: Issel L. Michele , Baldwin Kathleen A. , Lyons Roberta L. , Madamala Kusuma
Published: May 2006

ABSTRACT
Having a public health workforce with a high level of competency is a prerequisite for having an effective public health system. The purpose of these two studies was to assess the competency level of practicing public health nurses (PHNs; n=168) from 50 local health agencies and public health nursing faculty (n=46) from 31 nursing programs in Illinois. The questionnaire consisted of nine reliable scales using self‐reported levels of competence in each PHN competency domain. Overall, PHNs reported only feeling competent in one domain: “linking people to services.” Although PHN faculty felt competent across the nine domains, they did not report feeling competent to teach any of the domains. Thus, PHNs and public health nursing faculty need education and training to meet the professionally established level of competence.
Infantile Spasms: Little Seizures, BIG Consequences
Authors: Shields W. Donald
Published: May 2006

Infantile spasms is one of the “catastrophic childhood epilepsies” because of the difficulty in controlling seizures and the association with mental retardation. However, early recognition, a careful diagnostic evaluation, and proper treatment may allow some children to attain seizure control and to achieve a normal, or at least much improved, level of development. Thus, there is the opportunity to have an important impact in the lives of these unfortunate children and their families.
Beyond Market‐Oriented Readings of Paid Informal Work
Authors: Williams Colin C.
Published: May 2006

Abstract. Paid informal work is often conceptualized as a form of economic activity conducted under work relations akin to formal employment, heavily imbued with profit motivations on the part of both the consumer and supplier. The aim of this article, however, is to evaluate critically this market‐oriented reading of paid informal work. Drawing upon face‐to‐face interviews with 350 households in five localities in rural England, the finding is that just 7 percent of paid informal tasks are conducted for businesses and people that suppliers do not define as friends, neighbors, or kin, and only 17 percent for primarily profit‐motivated purposes. This article thus displays the need to move away from a market‐oriented reading of paid informal work and to recognize the heterogeneity of the social relations and motives involved in this sphere.
Prevalence and molecular characterization of the polymerase gene of gibbon lymphocryptovirus
Authors: Phakdeewirot Piraya , Payungporn Sunchai , Chutinimitkul Salin , Theamboonlers Apiradee , Poovorawan Yong
Published: May 2006

Background  Lymphocryptovirus (LCV) is found in various non‐human primates. As a herpesvirus naturally infecting gibbons it is closely related to human Epstein–Barr virus (EBV) with which it shares considerable genetic, biological and epidemiologic features.

Methods  We collected blood samples from 70 gibbons (51 Hylobates lar, 18 Hylobates pileatus and 1 Hylobates agilis) for further separation into serum and peripheral blood mononuclear cells (PBMC).

Results  Only 13 of 70 (18.6%) sera were serologically positive for human EBV IgG but 64 of 70 (91.4%) PBMCs yielded the partial LCV DNA polymerase gene by semi‐nested PCR, which we subjected to direct sequencing. All sequences showed 84% nucleic acid and 91% amino acid identity to human EBV. Phylogenetic tree analysis demonstrated gibbon LCVs clustered separately from other gammaherpesvirinae but closely related to LCV of other species.

Conclusions  Based on LCV DNA detection, we discovered a high prevalence of LCV infection among gibbons. Further characterization of non‐human primate LCV might thus provide new insight into both evolution and pathogenicity of gammaherpesvirinae.
Experimental infection of rhesus macaques with Streptococcus pneumoniae: a possible model for vaccine assessment
Authors: Philipp Mario T. , Purcell Jeanette E. , Martin Dale S. , Buck Wayne R. , Plauché Gail B. , Ribka Erin P. , DeNoel Philippe , Hermand Philippe , Leiva Lily E. , Bagby Gregory J. , Nelson Steve
Published: May 2006

Background  We explored the possibility of using normal adult rhesus macaques for the preclinical assessment of safety, immunogenicity, and efficacy of newly developed vaccines against Streptococcus pneumoniae infection of the lung.

Methods  Our primary objective was to determine whether an intra‐bronchial inoculum of at least 106S. pneumoniae colony‐forming units, or one as high as 108–109 organisms, could detectably survive in rhesus macaques for a period longer than 1–2 weeks. If so, we hypothesized, it would be possible to observe signs of pneumonia commonly observed in humans, and discriminate between vaccinated/protected animals and controls. Infection was detectable in bronchoalveolar lavage fluids 3–5 weeks post‐inoculation.

Results  The clinical course of disease mimicked aspects of that of human pneumococcal pneumonia. Signs of inflammation typical of the disease in humans, such as elevated concentrations of neutrophils and of pro‐inflammatory cytokines in bronchoalveolar lavage fluids were also observed.

Conclusions  These findings underscore the utility of this model to assess the safety, immunogenicity, and efficacy of newly developed S. pneumoniae vaccines.
Effect of calcium, given before or after a fluoride insult, on hamster secretory amelogenesis in vitro
Authors: Bronckers Antonius L. J. J. , Bervoets Theodorus J. M. , Wöltgens Joseph H. M. , Lyaruu Donacian M.
Published: May 2006

We tested the hypothesis that high‐calcium medium given prior to or immediately after exposure to fluoride (F) reduces the negative effects of F on secretory amelogenesis. Hamster molar tooth germs were grown in organ culture in media with different calcium levels. Deposition of enamel matrix and matrix mineralization were monitored by incorporation of [3H]proline and uptake of 45Ca and acid‐soluble 32PO4. Ameloblast structure and the occurrence of a fluorotic enamel matrix were examined by light and electron microscopy. A preculture of explants in high‐calcium medium partially prevented the formation of fluorotic (non‐mineralizing) enamel matrix, increased matrix secretion but could not prevent F‐induced hypermineralization of the pre‐exposure enamel. High‐calcium medium, applied after F insult, accelerated the recovery of fluorotic matrix, improved ameloblast structure, enhanced amelogenin secretion, and increased enamel thickness. The data indicate that it might be the balance between the amount of mineral deposition and that of matrix secretion which is critical for the mineralization of newly secreted enamel. Exposure to F disturbs this balance by enhancing mineralization of the pre‐exposure enamel, probably generating an excess of protons. High calcium may protect against F exposure by enhancing amelogenin secretion into the enamel space, thereby increasing the local buffering capacity at the mineralization front.
The effect of enamel matrix derivative on gene expression in osteoblasts
Authors: Reseland Janne E. , Reppe Sjur , Larsen Aileen M. , Berner Heidi S. , Reinholt Finn P. , Gautvik Kaare M. , Slaby Ivan , Lyngstadaas S. Petter
Published: May 2006

Observations that amelogenins, in the form of enamel matrix derivative (EMD), have a stimulatory effect on mesenchymal cells and tissues, and on the regeneration of alveolar bone, justified investigations into the effect of EMD on bone‐forming cells. The binding and uptake of EMD in primary osteoblastic cells was characterized, and the effect of EMD on osteoblast gene expression, protein secretion, and mineralization was compared with the effect of parathyroid hormone (PTH). Although no specific receptor(s) has yet been identified, EMD appeared to be taken up by osteoblasts through clathrin‐coated pits via the interaction with clathrin adaptor protein complex AP‐2, the major mechanism of cargo sorting into coated pits in mammalian cells. EMD had a positive effect on factors involved in mineralization in vitro, causing an increased alkaline phosphatase (ALP) activity in the medium as well an as increased expression of osteocalcin and collagen type 1. Several hundred genes are regulated by EMD in primary human osteoblasts. There appear to be similarities between the effects of EMD and PTH on human osteoblasts. The expression pattern of several mRNAs and proteins upon EMD stimulation also indicates a secondary osteoclast stimulatory effect, suggesting that the osteogenic effect of EMD in vivo, at least partly, involves stimulation of bone remodelling.
The 17‐kDa sheath protein in enamel proteins induces cementum regeneration in experimental cavities created in a buccal dehiscence model of dogs
Authors: Kanazashi M. , Gomi K. , Nagano T. , Tanabe T. , Arai T. , Fukae M.
Published: May 2006

Background and Objective:  Commercially available enamel proteins, such as Emdogain®, are clinically used for periodontal regeneration. However, the real mechanisms behind the bioactivities of enamel proteins is still unclear, as enamel proteins have multicomponents. The purpose of this in vivo study was to identify the cementum regeneration‐promoting factor in enamel proteins that is clinically used for periodontal regeneration to induce cementum‐promotive and osteopromotive activities.

Material and Methods:  Cementum regeneration, which is an important part of periodontal regeneration, was examined in experimental cavities prepared on a buccal dehiscence model of dogs. The purification of enamel protein with cementum regeneration activity was carried out by gel filtration and ion exchange chromatographies of newly formed secretory enamel.

Results:  Cementum regeneration activity was found in the aggregate comprising 13–17‐kDa sheath proteins along with a small amount of amelogenins, found in the newly formed secretory enamel. In these proteins, cementum regeneration activity was detected upon application of the 17‐kDa sheath protein, but not by other lower molecular‐weight sheath proteins and amelogenins. However, the purified 17‐kDa sheath protein induced cementum regeneration activity only in a small area, although the regenerated cementum was thick. The activity of the 17‐kDa sheath protein was believed not to have been a result of contamination by growth factors such as transforming growth factor‐β1 (TGF‐β1) found in the enamel protein, as the application of TGF‐β1 induced weak cementum regeneration activity.

Conclusion:  It is concluded that the 17‐kDa sheath protein itself exhibits cementum regeneration activity, although other factors may be needed to demonstrate its full ability.
Development and Application of an Anisotropic Two-Equation Model for Flows With Swirl and Curvature
Authors: Wang Xiaohua , Thangam Siva
Published: May 2006

An anisotropic two-equation model is developed through a novel technique that involves the representation of the energy spectrum and invariance based scaling. In this approach the effect of rotation is used to modify the energy spectrum, while the influence of swirl is modeled based on scaling laws. The resulting generalized two-equation turbulence model is validated for several benchmark turbulent flows with swirl and curvature.
Partially Averaged Navier-Stokes Method for Turbulence: Fixed Point Analysis and Comparison With Unsteady Partially Averaged Navier-Stokes
Authors: Girimaji Sharath S. , Jeong Eunhwan , Srinivasan Ravi
Published: May 2006

Hybrid/bridging models that combine the advantages of Reynolds averaged Navier Stokes (RANS) method and large-eddy simulations are being increasingly used for simulating turbulent flows with large-scale unsteadiness. The objective is to obtain accurate estimates of important large-scale fluctuations at a reasonable cost. In order to be effective, these bridging methods must posses the correct “energetics”: that is, the right balance between production (P) and dissipation (ε). If the model production-to-dissipation ratio (P∕ε) is inconsistent with turbulence physics at that cutoff, the computations will be unsuccessful. In this paper, we perform fixed-point analyses of two bridging models—partially-averaged Navier Stokes (PANS) and unsteady RANS (URANS)—to examine the behavior of production-to-dissipation ratio. It is shown that the URANS-(P∕ε) ratio is too high rendering it incapable of resolving much of the fluctuations. On the other hand, the PANS-(P∕ε) ratio allows the model to vary smoothly from RANS to DNS depending upon the values of its resolution control parameters.
Entropy Based Design of Fuel Cells
Authors: Naterer G. F. , Tokarz C. D.
Published: May 2006

This article aims to develop an entropy based method of systematically improving efficiency of fuel cells. Entropy production of both electrochemical and thermofluid irreversibilities is formulated based on the Second Law. Ohmic, concentration, and activation irreversibilities occur within the electrodes, while thermal and friction irreversibilities occur within the fuel channel. These irreversibilities reduce the overall cell efficiency by generating voltage losses. Unlike past studies, this article considers fuel channel irreversibilities within the total entropy production, for both solid oxide fuel cells (SOFCs) and proton exchange membrane fuel cells (PEMFCs). Predicted results of entropy production are shown at varying operating temperatures, surface resistances, and channel configurations. Numerical predictions are compared successfully against past measured data of voltage profiles, thereby providing useful validation of the entropy based formulation. The Second Law stipulates the maximum theoretical capability of energy conversion within the fuel cell. Unlike past methods characterizing voltage losses through overpotential or polarization curves, the entropy based method provides a useful alternative and systematic procedure for reducing voltage losses.
Numerical Simulation of the Particle Motion Characteristics in
Boundary Layer of Gas-Solid Rotary Flow
Authors: Ran Jingyu , Zhang Li , Tang Qiang , Xin Mingdao
Published: May 2006

The boundary-layer feature and the forces on the particle are analyzed in detail, and the motion parameters of the particle in the gas-solid rotary flow are divided into two parts according to the r-z meridian and r-θ cross section. The Lagrange method is then applied, the 3-D mathematical model of particle motion in the gas-solid rotary flow is presented, and the Gear integral method is applied to simulate the motion characteristics of the particles. The results show that the centrifugal force and Saffman lift force play important roles in the process of the particle being separated from the gas-solid rotary flow in the rotary boundary layer. The velocity gradient of radial direction is the biggest, and that of tangent direction is the smallest. For a higher density ratio of gas to solid, the deposition performance of the particle depends not only on the inlet flow velocity but also on the range of the particle diameter. Reasonable velocity gradient matching of the three directions (r,z,θ) in the gas-solid rotary flow is useful to improve the separation efficiency of the rotary separators.
Intercomparison of methods for image quality characterization. I. Modulation transfer functiona)
Authors: Samei Ehsan , Ranger Nicole T. , Dobbins James T. , Chen Ying
Published: May 2006

The modulation transfer function (MTF) and the noise power spectrum (NPS) are widely recognized as the most relevant metrics of resolution and noise performance in radiographic imaging. These quantities have commonly been measured using various techniques, the specifics of which can have a bearing on the accuracy of the results. As a part of a study aimed at comparing the relative performance of different techniques, in this paper we report on a comparison of two established MTF measurement techniques: one using a slit test device [Dobbins et al., Med. Phys. 22, 1581–1593 (1995)] and another using a translucent edge test device [Samei et al., Med. Phys. 25, 102–113 (1998)], with one another and with a third technique using an opaque edge test device recommended by a new international standard (IEC 62220‐1, 2003). The study further aimed to substantiate the influence of various acquisition and processing parameters on the estimated MTF. The slit test device was made of thick Pb slabs with a opening. The translucent edge test device was made of a laminated and polished alloy foil of thickness. The opaque edge test device was made of a thick W slab. All test devices were imaged on a representative indirect flat‐panel digital radiographic system using three published beam qualities: with Cu filtration, with Al filtration, and with Al filtration (IEC‐RQA5). The latter technique was also evaluated in conjunction with two external beam‐limiting apertures (per IEC 62220‐1), and with the tube collimator limiting the beam to the same area achieved with the apertures. The presampled MTFs were deduced from the acquired images by Fourier analysis techniques, and the results analyzed for relative values and the influence of impacting parameters. The findings indicated that the measurement technique has a notable impact on the resulting MTF estimate, with estimates from the overall IEC method lower than that of Dobbins et al. and higher than that of Samei et al. averaged over the zero to cutoff frequency range. Over the same frequency range, keeping beam quality and limitation constant, the average MTF estimate obtained with the edge techniques differed by up to from that of the slit, with the opaque edge providing lower MTF estimates at lower frequencies than those obtained with the translucent edge or slit. The beam quality impacted the average estimated MTF by as much as while the use of beam limiting devices alone increased the average estimated MTF by as much as . While the slit method is inherently very sensitive to misalignment, both edge techniques were found to tolerate misalignments by as much as . The results suggest the use of the opaque edge test device and the tube internal collimator for beam limitation in order to achieve an MTF result most reflective of the overall performance of the imaging system and least susceptible to misalignment and scattered radiation. Careful attention to influencing factors is warranted to achieve accurate results.
Three‐dimensional dose verification for intensity modulated radiation therapy using optical CT based polymer gel dosimetry
Authors: Wuu Cheng‐Shie , Xu Y.
Published: May 2006

Dose distributions generated from intensity‐modulated‐radiation‐therapy (IMRT) treatment planning present high dose gradient regions in the boundaries between the target and the surrounding critical organs. Dose accuracy in these areas can be critical, and may affect the treatment. With the increasing use of IMRT in radiotherapy, there is an increased need for a dosimeter that allows for accurate determination of three‐dimensional (3D) dose distributions with high spatial resolution. In this study, polymer gel dosimetry and an optical CT scanner have been employed to implement 3D dose verification for IMRT. A plastic cylinder of diameter and height, filled with BANG®3 polymer gels (MGS Research, Inc., Madison, CT) and modified to optimal dose‐response characteristics, was used for IMRT dose verification. The cylindrical gel phantom was immersed in a water tank for an IMRT irradiation. The irradiated gel sample was then scanned with an optical CT scanner (MGS Research Inc., Madison, CT) utilizing a single laser beam and a single photodiode detector. Similar to the x‐ray CT process, filtered back‐projection was used to reconstruct the 3D dose distribution. The dose distributions measured from the gel were compared with those from the IMRT treatment planning system. For comparative dosimetry, a solid water phantom of , having the same geometry as the water tank for the gel phantom, was used for EDR2 film and ion chamber measurements. Root mean square (rms) deviations for both dose difference and distance‐to‐agreement (DTA) were used in three‐dimensional analysis of the dose distribution comparison between treatment planning calculations and the gel measurement. Comparison of planar dose distributions among gel dosimeter, film, and the treatment planning system showed that the isodose lines were in good agreement on selected planes in axial, coronal, and sagittal orientations. Absolute point‐dose verification was performed with ion chamber measurements at four different points, varying from 48% to 110% of the prescribed dose. The measured and calculated doses were found to agree to within 4.2% at all measurement points. For the comparison between the gel measurement and treatment planning calculations, rms deviations were 2%–6% for dose difference and for DTA, at 60%–110% doses levels. The results from this study show that optical CT based polymer gel dosimetry has the potential to provide a high resolution, accurate, three‐dimensional tool for IMRT dose distribution verification.
Fully adaptive FEM based fluorescence optical tomography from time‐dependent measurements with area illumination and detection
Authors: Joshi Amit , Bangerth Wolfgang , Hwang Kildong , Rasmussen John C. , Sevick‐Muraca Eva M.
Published: May 2006

Using an area‐illumination and area‐detection scheme, we acquire fluorescence frequency domain measurements from a tissue phantom with an embedded fluorescent target and obtain tomographic reconstructions of the interior fluorescence absorption map with an adaptive finite element based scheme. The tissue phantom consisted of a clear acrylic cubic box filled with 1% Liposyn solution, while the fluorescent targets were diameter glass bulbs filled with Indocyanine Green dye solution in 1% Liposyn. Frequency domain area illumination and detection employed a planar excitation source using an expanded intensity modulated diode laser light and a gain modulated image intensified charge coupled device camera, respectively. The excitation pattern was characterized by isolating the singly scattered component with cross polarizers and was input into a dual adaptive finite element‐based scheme for three dimensional reconstructions of fluorescent targets embedded beneath the phantom surface. Adaptive mesh refinement techniques allowed efficient simulation of the incident excitation light and the reconstruction of fluorescent targets buried at the depths of 1 and . The results demonstrate the first clinically relevant noncontact fluorescence tomography with adaptive finite element methods.
Characterization of a new radiochromic three‐dimensional dosimeter
Authors: Guo P. Y. , Adamovics J. A. , Oldham M.
Published: May 2006

The development of intensity‐modulated radiotherapy (IMRT) has created a clear need for a dosimeter that can accurately and conveniently measure dose distributions in three dimensions to assure treatment quality. is a new three dimensional (3D) dosimetry material consisting of an optically clear polyurethane matrix, containing a leuco dye that exhibits a radiochromic response when exposed to ionizing radiation. A number of potential advantages accrue over other gel dosimeters, including insensitivity to oxygen, radiation induced light absorption contrast rather than scattering contrast, and a solid texture amenable to machining to a variety of shapes and sizes without the requirement of an external container. In this paper, we introduce an efficient method to investigate the basic properties of a 3D dosimetry material that exhibits an optical dose response. The method is applied here to study the key aspects of the optical dose response of : linearity, dose rate dependency, reproducibility, stability, spectral changes in absorption, and temperature effects. was prepared in optical cuvettes for convenience and was irradiated by both photon and electron beams to different doses, dose rates, and energies. Longer columns were formed without an external container, for measurements of photon and high energy electron depth‐dose curves. A linear optical scanning technique was used to detect the depth distribution of radiation induced optical density (OD) change along the columns and cuvettes. Measured depth‐OD curves were compared with percent depth dose (PDD). Results indicate that has a linear optical response to radiation dose (with a root mean square error of ), little dependency on dose rate , high intrabatch reproducibility , and can be stable during 2 hours to 2 days post irradiation. Accurate dosimetry requires temperature control within . Variations in the formulation yield corresponding variations in sensitivity, stability, and density. CT numbers in the range 100–470 were observed. In conclusion, the small volume studies presented here indicate to be a promising, versatile, and practical new dosimetry material with applicability for radiation therapy.
Differences in the lesion formation process between focused ultrasound and microwave ablations
Authors: Chen Wen‐Shiang , Wu Chih‐Ching , Fang Hsin‐Yu , Liu Hao‐Li
Published: May 2006

The objective is to understand the differences in the lesion formation processes between microwave and high‐intensity focused ultrasound (HIFU) ablation. The lesions formed by microwaves and HIFU were real‐time monitored and compared using transparent tissue‐mimicking phantoms at 60 and of driving electrical power. Microwaves and HIFU produced lesions different in shape, size, and developing processes. For HIFU ablations, the hyperechoic region appeared bigger in ultrasonic images, as compared with the protein denatured region observed optically at the end of ablations. On the contrary, the hyperechoic signal was only limited to a small region along the antenna of a microwave ablator. Careful monitoring and controlling the lesion formation process is essential for successful microwaves and HIFU thermal ablations.
Inactivation of Enterohemorrhagic
Escherichia coli
in Rumen Content- or Feces-Contaminated Drinking Water for Cattle
Authors: Zhao Tong , Zhao Ping , West Joe W. , Bernard John K. , Cross Heath G. , Doyle Michael P.
Published: May 2006

Cattle drinking water is a source of on-farm
Escherichia coli
O157:H7 transmission. The antimicrobial activities of disinfectants to control
E. coli
O157:H7 in on-farm drinking water are frequently neutralized by the presence of rumen content and manure that generally contaminate the drinking water. Different chemical treatments, including lactic acid, acidic calcium sulfate, chlorine, chlorine dioxide, hydrogen peroxide, caprylic acid, ozone, butyric acid, sodium benzoate, and competing
E. coli
, were tested individually or in combination for inactivation of
E. coli
O157:H7 in the presence of rumen content. Chlorine (5 ppm), ozone (22 to 24 ppm at 5°C), and competing
E. coli
treatment of water had minimal effects (<1 log CFU/ml reduction) on killing
E. coli
O157:H7 in the presence of rumen content at water-to-rumen content ratios of 50:1 (vol/wt) and lower. Four chemical-treatment combinations, including (i) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 0.05% caprylic acid (treatment A); (ii) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 0.1% sodium benzoate (treatment B); (iii) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 0.5% butyric acid (treatment C); and (iv) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 100 ppm chlorine dioxide (treatment D); were highly effective (>3 log CFU/ml reduction) at 21°C in killing
E. coli
O157:H7, O26:H11, and O111:NM in water heavily contaminated with rumen content (10:1 water/rumen content ratio [vol/wt]) or feces (20:1 water/feces ratio [vol/wt]). Among them, treatments A, B, and C killed >5 log CFU
E. coli
O157:H7, O26:H11, and O111:NM/ml within 30 min in water containing rumen content or feces, whereas treatment D inactivated approximately 3 to 4 log CFU/ml under the same conditions. Cattle given water containing treatment A or C or untreated water (control) ad libitum for two 7-day periods drank 15.2, 13.8, and 30.3 liters/day, respectively, and cattle given water containing 0.1% lactic acid plus 0.9% acidic calcium sulfate (pH 2.1) drank 18.6 liters/day. The amounts of water consumed for all water treatments were significantly different from that for the control, but there were no significant differences among the water treatments. Such treatments may best be applied periodically to drinking water troughs and then flushed, rather than being added continuously, to avoid reduced water consumption by cattle.
l
-Methionine Degradation Pathway in
Kluyveromyces lactis
: Identification and Functional Analysis of the Genes Encoding
l
-Methionine Aminotransferase
Authors: Kagkli Dafni-Maria , Bonnarme Pascal , Neuvéglise Cécile , Cogan Timothy M. , Casaregola Serge
Published: May 2006

Kluyveromyces lactis
is one of the cheese-ripening yeasts and is believed to contribute to the formation of volatile sulfur compounds (VSCs) through degradation of
l
-methionine.
l
-Methionine aminotransferase is potentially involved in the pathway that results in the production of methanethiol, a common precursor of VSCs. Even though this pathway has been studied previously, the genes involved have never been studied. In this study, on the basis of sequence homology, all the putative aminotransferase-encoding genes from
K. lactis
were cloned in an overproducing vector, pCXJ10, and their effects on the production of VSCs were analyzed. Two genes, Kl
ARO8.1
and Kl
ARO8.2
, were found to be responsible for
l
-methionine aminotransferase activity. Transformants carrying these genes cloned in the pCXJ10 vector produced threefold-larger amounts of VSCs than the transformant containing the plasmid without any insert or other related putative aminotransferases produced.