bluuebunny/crossref_metadata_2025 huggingface dataset:
High-field-effect-mobility pentacene thin-film transistors with polymethylmetacrylate buffer layer
Authors: De Angelis F. , Cipolloni S. , Mariucci L. , Fortunato G.
Published: May 2005

A thin film of polymethylmetacrylate (PMMA) acting as a buffer layer has been employed in order to fabricate high-quality pentacene thin-film transistors (TFTs), both in bottom contact and top contact configuration. A PMMA buffer layer allows to reduce the interaction between a π-conjugated system of pentacene and the metal or dielectric substrate. We show that a thin PMMA buffer layer improves crystal quality along the metal contacts’ boundaries, while still allowing good ohmic contact. Pentacene TFTs, including a PMMA buffer layer, show very high field-effect mobility, μFE=0.65 and 1.4cm2∕Vs, for bottom and top contact configuration, respectively, and remarkable steep subthreshold region.
Strong flexural resonant magnetoelectric effect in Terfenol-D∕epoxy-Pb(Zr,Ti)O3 bilayer
Authors: Wan J. G. , Li Z. Y. , Wang Y. , Zeng M. , Wang G. H. , Liu J.-M.
Published: May 2005

We report the bending resonant magnetoelectric effect observed in the bilayer of magnetostrictive Tb0.30Dy0.7Fe2 (Terfenol-D)∕epoxy and piezoelectric Pb(Zr0.52Ti0.48)O3 (PZT). It has been found that the bilayer has both giant magnetoelectric voltage coefficient and high coupling efficiency when it operates at the first bending resonance mode. The maximum bending resonant magnetoelectric voltage coefficient of 14.6V∕cmOe at quite low frequency of 12.5 kHz was observed in the bilayer of small sizes of 17.4×4.0×1.44mm3. This bending-resonance-type magnetoelectric effect shows promising application in transducers for magnetoelectric energy conversion.
Mice lacking multidrug resistance protein 3 show altered morphine pharmacokinetics and morphine-6-glucuronide antinociception
Authors: Zelcer Noam , van de Wetering Koen , Hillebrand Michel , Sarton Elise , Kuil Annemieke , Wielinga Peter R. , Tephly Thomas , Dahan Albert , Beijnen Jos H. , Borst Piet
Published: May 2005

Glucuronidation is a major detoxification pathway for endogenous and exogenous compounds in mammals that results in the intracellular formation of polar metabolites, requiring specialized transporters to cross biological membranes. By using morphine as a model aglycone, we demonstrate that multidrug resistance protein 3 (MRP3/ABCC3), a protein present in the basolateral membrane of polarized cells, transports morphine-3-glucuronide (M3G) and morphine-6-glucuronidein vitro.Mrp3(-/-)mice are unable to excrete M3G from the liver into the bloodstream, the major hepatic elimination route for this drug. This results in increased levels of M3G in liver and bile, a 50-fold reduction in the plasma levels of M3G, and in a major shift in the main disposition route for morphine and M3G, predominantly via the urine in WT mice but via the feces inMrp3(-/-)mice. The pharamacokinetics of injected morphine-glucuronides are altered as well in the absence of Mrp3, and this results in a decreased antinociceptive potency of injected morphine-6-glucuronide.
Studies of yeast oligosaccharyl transferase subunits using the split-ubiquitin system: Topological features and
in vivo
interactions
Authors: Yan Aixin , Wu Elain , Lennarz William J.
Published: May 2005

Oligosaccharyl transferase (OT) catalyzes the cotranslational N-glycosylation of nascent polypeptides in the endoplasmic reticulum in all eukaryotic systems. Due to the inherent difficulty in characterizing this membrane protein complex, the mode of enzymatic action has not been resolved. Here, we used a membrane protein two-hybrid approach, the split-ubiquitin system, to address two aspects of the enzyme complex in yeast: the topological features, as well as the
in vivo
interactions of all of the components. We investigated the N- and C-terminal orientation of these proteins and the presence or the absence of a cleavable signal sequence at their N termini. We found that Ost2p and Stt3p have only their N terminus located in the cytosol, whereas Ost3p and Swp1p have only their C terminus oriented in the cytosol. In the case of Ost5p and Ost6p, both their N and C termini are present in the cytosol. These findings also suggested that Ost2p, Stt3p, Ost5p, and Ost6p do not have a cleavable N-terminal signal sequence. The pairwise analysis of
in vivo
interactions among all of the OT subunits demonstrated that OT subunits display specific interactions with each other in a functional complex. By comparing this interaction pattern with that detected
in vitro
in a nonfunctional complex, we proposed that a distinct conformation rearrangement takes place when the enzyme complex changes from the nonfunctional state to the activated functional state. This finding is consistent with earlier work by others indicating that OT exhibits allosteric properties.
A general proof of the conservation of the curvature perturbation
Authors: Lyth David H , Malik Karim A , Sasaki Misao
Published: May 2005

Without invoking a perturbative expansion, we define the cosmological curvature perturbation, and consider its behaviour assuming that the universe is smooth over a sufficiently large comoving scale. The equations are simple, resembling closely the first-order equations, and they lead to results which generalize those already proven in linear perturbation theory and (in part) in second-order perturbation theory. In particular, the curvature perturbation is conserved provided that the pressure is a unique function of the energy density.
When More Is Less: Integrating Qualitative Information and Boolean Statistics
Authors: Braumoeller Bear F. , Kirpichevsky Yevgeniy
Published: May 2005

Gordon and Smith (2004) do a great service by introducing innovative and creative quantitative methods that incorporate information from qualitative sources. It is nevertheless important to examine the conditions under which the proposed estimators will be useful in practice. These conditions prove to be surprisingly restrictive: with the possible exception of extremely low-information settings, virtually all of the cases of discernible causation must be coded as such, those codings must contain virtually no errors, and the process by which qualitative researchers produce evaluations of discernibility must conform to the authors' model of the qualitative data-generating process (QDGP) if the procedures are to retain any comparative advantage.
Safety in numbers? Shoaling behaviour of the Amazonian red-bellied piranha
Authors: Queiroz Helder , Magurran Anne E
Published: May 2005

Red-bellied piranha (Pygocentrus nattereri) shoals have a fearsome reputation. However, the variety and abundance of piranha predators in the flooded forests of the Amazon in which they live indicate that an important reason for shoal formation may be predator defence. Experiments using wild-caught piranhas supported the hypothesis that individual perception of risk, as revealed by elevated ventilatory frequency (opercular rate), is greater in small shoals. Moreover, exposure to a simulated predator attack by a model cormorant demonstrated that resting opercular rates are regained more quickly by piranhas in shoals of eight than they are in shoals of two. Together, these results show that shoaling has a cover-seeking function in this species.
Impacts of fever on locust life-history traits: costs or benefits?
Authors: Elliot Sam L , Horton Charlotte M , Blanford Simon , Thomas Matthew B
Published: May 2005

Fever, like other mechanisms for defence against pathogens, may have positive and negative consequences for host fitness. In ectotherms, fever can be attained through modified behavioural thermoregulation. Here we examine potential costs of behavioural fever by holding adult, gregarious desert locusts at elevated temperatures simulating a range of fever intensities. We found no effect of fever temperatures on primary fitness correlates of survival and fecundity. However, flight capacity and mate competition were reduced, although there was no relation between time spent at fever temperatures and magnitude of the response. While these effects could indicate a direct cost of fever, they are also consistent with a shift towards thesolitariaphase state that, in a field context, could be considered an adaptive life-history response to limit the impact of disease. These conflicting interpretations highlight the importance of considering complex defence mechanisms and trade-offs in an appropriate ecological context.
Spatial processes can determine the relationship between prey encounter rate and prey density
Authors: Travis J.M.J , Palmer S.C.F
Published: May 2005

Theoretical models frequently assume that the rate at which a searching predator encounters prey increases linearly with prey density. In a recent experiment using great tits searching for winter moth caterpillars, the time to find the first prey item did not decline as quickly with density as the standard theory assumes. Using a spatial simulation model, we show that prey aggregation and/or spatially correlated searching behaviour by the predator can generate a range of relationships, including results that are qualitatively similar to those found in the great tit experiment. We suggest that further experiments are required to determine whether the explanation proposed here is correct, and that theoretical work is needed to determine how this behaviour is likely to influence the ecological and evolutionary dynamics of predator–prey communities.
Parametric study of the effect of phase anisotropy on the micromechanical behaviour of dentin–adhesive interfaces
Authors: Misra Anil , Spencer Paulette , Marangos Orestes , Wang Yong , Katz J. Lawrence
Published: May 2005

A finite element (FE) model has been developed based upon the recently measured micro-scale morphological, chemical and mechanical properties of dentin–adhesive (d–a) interfaces using confocal Raman microspectroscopy and scanning acoustic microscopy (SAM). The results computed from this FE model indicated that the stress distributions and concentrations are affected by the micro-scale elastic properties of various phases composing the d–a interface. However, these computations were performed assuming isotropic material properties for the d–a interface. The d–a interface components, such as the peritubular and intertubular dentin, the partially demineralized dentin and the so-called ‘hybrid layer’ adhesive-collagen composite, are probably anisotropic. In this paper, the FE model is extended to account for the probable anisotropic properties of these d–a interface phases. A parametric study is performed to study the effect of anisotropy on the micromechanical stress distributions in the hybrid layer and the peritubular dentin phases of the d–a interface. It is found that the anisotropy of the phases affects the region and extent of stress concentration as well as the location of the maximum stress concentrations. Thus, the anisotropy of the phases could effect the probable location of failure initiation, whether in the peritubular region or in the hybrid layer.
Molecular imaging perspectives
Authors: Cassidy Paul J , Radda George K
Published: May 2005

Molecular imaging is an emerging technology at the life science/physical science interface which is set to revolutionize our understanding and treatment of disease. The tools of molecular imaging are the imaging modalities and their corresponding contrast agents. These facilitate interaction with a biological target at a molecular level in a number of ways. The diverse nature of molecular imaging requires knowledge from both the life and physical sciences for its successful development and implementation. The aim of this review is to introduce the subject of molecular imaging from both life science and physical science perspectives. However, we will restrict our coverage to the prominentin vivomolecular imaging modalities of magnetic resonance imaging, optical imaging and nuclear imaging. The physical basis of these imaging modalities, the use of contrast agents and the imaging parameters of sensitivity, temporal resolution and spatial resolution are described. Then, the specificity of contrast agents for targeting and sensing molecular events, and some applications of molecular imaging in biology and medicine are given. Finally, the diverse nature of molecular imaging and its reliance on interdisciplinary collaboration is discussed.
Prediction of elastic properties of carbon nanotube reinforced composites
Authors: Hu N , Fukunaga H , Lu C , Kameyama M , Yan B
Published: May 2005

In this paper, the macroscopic elastic properties of carbon nanotube reinforced composites are evaluated through analysing the elastic deformation of a representative volume element (RVE) under various loading conditions. This RVE contains three components, i.e. a carbon nanotube, a transition layer between the nanotube and polymer matrix and an outer polymer matrix body. First, based on the force field theory of molecular mechanics and computational structural mechanics, an equivalent beam model is constructed to model the carbon nanotube effectively. The explicit relationships between the material properties of the equivalent beam element and the force constants have been set-up. Second, to describe the interaction between the nanotube and the outer polymer matrix at the level of atoms, the molecular mechanics and molecular dynamics computations have been performed to obtain the thickness and material properties of the transition layer. Moreover, an efficient three-dimensional eight-noded brick finite element is employed to model the transition layer and the outer polymer matrix. The macroscopic behaviours of the RVE can then be evaluated through the traditional finite element method. In the numerical simulations, the influences of various important factors, such as the stiffness of transition layer and geometry of RVE, on the final macroscopic material properties of composites have been investigated in detail.
Large-Scale Identification of Expressed Sequence Tags Involved in Rice and Rice Blast Fungus Interaction
Authors: Jantasuriyarat Chatchawan , Gowda Malali , Haller Karl , Hatfield Jamie , Lu Guodong , Stahlberg Eric , Zhou Bo , Li Huameng , Kim HyRan , Yu Yeisoo , Dean Ralph A. , Wing Rod A. , Soderlund Carol , Wang Guo-Liang
Published: May 2005

To better understand the molecular basis of the defense response against the rice blast fungus (Magnaporthe grisea), a large-scale expressed sequence tag (EST) sequencing approach was used to identify genes involved in the early infection stages in rice (Oryza sativa). Six cDNA libraries were constructed using infected leaf tissues harvested from 6 conditions: resistant, partially resistant, and susceptible reactions at both 6 and 24 h after inoculation. Two additional libraries were constructed using uninoculated leaves and leaves from the lesion mimic mutant spl11. A total of 68,920 ESTs were generated from 8 libraries. Clustering and assembly analyses resulted in 13,570 unique sequences from 10,934 contigs and 2,636 singletons. Gene function classification showed that 42% of the ESTs were predicted to have putative gene function. Comparison of the pathogen-challenged libraries with the uninoculated control library revealed an increase in the percentage of genes in the functional categories of defense and signal transduction mechanisms and cell cycle control, cell division, and chromosome partitioning. In addition, hierarchical clustering analysis grouped the eight libraries based on their disease reactions. A total of 7,748 new and unique ESTs were identified from our collection compared with the KOME full-length cDNA collection. Interestingly, we found that rice ESTs are more closely related to sorghum (Sorghum bicolor) ESTs than to barley (Hordeum vulgare), wheat (Triticum aestivum), and maize (Zea mays) ESTs. The large cataloged collection of rice ESTs in this study provides a solid foundation for further characterization of the rice defense response and is a useful public genomic resource for rice functional genomics studies.
FPC Web Tools for Rice, Maize, and Distribution
Authors: Pampanwar Vishal , Engler Friedrich , Hatfield James , Blundy Steve , Gupta Gaurav , Soderlund Carol
Published: May 2005

Many clone-based physical maps have been built with the FingerPrinted Contig (FPC) software, which is written in C and runs locally for fast and flexible analysis. If the maps were viewable only from FPC, they would not be as useful to the whole community since FPC must be installed on the user machine and the database downloaded. Hence, we have created a set of Web tools so users can easily view the FPC data and perform salient queries with standard browsers. This set includes the following four programs: WebFPC, a view of the contigs; WebChrom, the location of the contigs and genetic markers along the chromosome; WebBSS, locating user-supplied sequence on the map; and WebFCmp, comparing fingerprints. For additional FPC support, we have developed an FPC module for BioPerl and an FPC browser using the Generic Model Organism Project (GMOD) genome browser (GBrowse), where the FPC BioPerl module generates the data files for input into GBrowse. This provides an alternative to the WebChrom/WebFPC view. These tools are available to download along with documentation. The tools have been implemented for both the rice (Oryza sativa) and maize (Zea mays) FPC maps, which both contain the locations of clones, markers, genetic markers, and sequenced clone (along with links to sites that contain additional information).
BioMOBY Successfully Integrates Distributed Heterogeneous Bioinformatics Web Services. The PlaNet Exemplar Case
Authors: Wilkinson Mark , Schoof Heiko , Ernst Rebecca , Haase Dirk
Published: May 2005

The burden of noninteroperability between on-line genomic resources is increasingly the rate-limiting step in large-scale genomic analysis. BioMOBY is a biological Web Service interoperability initiative that began as a retreat of representatives from the model organism database community in September, 2001. Its long-term goal is to provide a simple, extensible platform through which the myriad of on-line biological databases and analytical tools can offer their information and analytical services in a fully automated and interoperable way. Of the two branches of the larger BioMOBY project, the Web Services branch (MOBY-S) has now been deployed over several dozen data sources worldwide, revealing some significant observations about the nature of the integrative biology problem; in particular, that Web Service interoperability in the domain of bioinformatics is, unexpectedly, largely a syntactic rather than a semantic problem. That is to say, interoperability between bioinformatics Web Services can be largely achieved simply by specifying the data structures being passed between the services (syntax) even without rich specification of what those data structures mean (semantics). Thus, one barrier of the integrative problem has been overcome with a surprisingly simple solution. Here, we present a nontechnical overview of the critical components that give rise to the interoperable behaviors seen in MOBY-S and discuss an exemplar case, the PlaNet consortium, where MOBY-S has been deployed to integrate the on-line plant genome databases and analytical services provided by a European consortium of databases and data service providers.
Databases and Information Integration for the Medicago truncatula Genome and Transcriptome
Authors: Cannon Steven B. , Crow John A. , Heuer Michael L. , Wang Xiaohong , Cannon Ethalinda K.S. , Dwan Christopher , Lamblin Anne-Francoise , Vasdewani Jayprakash , Mudge Joann , Cook Andrew , Gish John , Cheung Foo , Kenton Steve , Kunau Timothy M. , Brown Douglas , May Gregory D. , Kim Dongjin , Cook Douglas R. , Roe Bruce A. , Town Chris D. , Young Nevin D. , Retzel Ernest F.
Published: May 2005

An international consortium is sequencing the euchromatic genespace of Medicago truncatula. Extensive bioinformatic and database resources support the marker-anchored bacterial artificial chromosome (BAC) sequencing strategy. Existing physical and genetic maps and deep BAC-end sequencing help to guide the sequencing effort, while EST databases provide essential resources for genome annotation as well as transcriptome characterization and microarray design. Finished BAC sequences are joined into overlapping sequence assemblies and undergo an automated annotation process that integrates ab initio predictions with EST, protein, and other recognizable features. Because of the sequencing project's international and collaborative nature, data production, storage, and visualization tools are broadly distributed. This paper describes databases and Web resources for the project, which provide support for physical and genetic maps, genome sequence assembly, gene prediction, and integration of EST data. A central project Web site at medicago.org/genome provides access to genome viewers and other resources project-wide, including an Ensembl implementation at medicago.org, physical map and marker resources at mtgenome.ucdavis.edu, and genome viewers at the University of Oklahoma (www.genome.ou.edu), the Institute for Genomic Research (www.tigr.org), and Munich Information for Protein Sequences Center (mips.gsf.de).
Evolutionary Divergence of Monocot and Dicot Methyl-CpG-Binding Domain Proteins
Authors: Springer Nathan M. , Kaeppler Shawn M.
Published: May 2005

The covalent modification of eukaryotic DNA by methylation of the 5′ carbon of cytosine residues is frequently associated with transcriptional silencing. In mammals, a potential mechanism for transducing DNA methylation patterns into altered transcription levels occurs via binding of methyl-CpG-binding domain (MBD) proteins. Mammalian MBD-containing proteins bind specifically to methylated DNA and recruit chromatin-modifying complexes containing histone deacetylase activities. Sequence similarity searches reveal the presence of multiple proteins in plants containing a putative MBD. Outside of the MBD itself, there is no sequence relationship between plant and mammalian MBD proteins. The plant MBD proteins can be divided into eight classes based on sequence similarity and phylogenetic analyses of sequences obtained from two complete genomes (rice [Oryza sativa] and Arabidopsis [Arabidopsis thaliana]) and from maize (Zea mays). Two classes of MBD proteins are only represented in dicot species. The striking divergence of plant and animal MBD-containing proteins is in stark contrast to the amino acid conservation of DNA methyltransferases across plants, animals, and fungi. This observation suggests the possibility that while plants and mammals have retained similar mechanisms for the establishment and maintenance of DNA methylation patterns, they may have evolved distinct mechanisms for the interpretation of these patterns.
Evaluation of simple non‐invasive techniques for assessment of lower extremity arterial disease
Authors: Sahli David , Svensson Maria , Lidgren Joakim , Öjbrandt Kristina , Eriksson Jan W.
Published: May 2005

Objective:  To evaluate the reproducibility and precision of three, simple, non‐invasive methods to measure blood pressure (BP) in the lower extremities by comparing reproducibility and sensitivity in finding abnormally low BP between ankle blood pressure (ABP) and toe blood pressure (TBP), by studying the concordance between TBP in toe 1 and 2 and evaluating the pole‐pox method in patients with diabetes and lower extremity arterial disease (LEAD).

Subjects and methods:  The BP was measured twice, 1 week apart, in arms and legs in 13 controls and 12 patients with diabetes. ABP was assessed by using a Doppler pen for pulse registration. TBP was obtained by using a small cuff and a pulse oximetry sensor at toe 1 and 2. In eleven patients with diabetes and previously known LEAD ABP was obtained through the pole‐pox method.

Results:  No significant difference in reproducibility between absolute BPs and indices (coefficients of variation <9%) was found. A non‐significant improvement with 4–8% in the sensitivity in detecting LEAD was seen when BP indices were used instead of absolute BP. A significant correlation in the variation over time for systemic and TBP (r = 0·34, P = 0·015) and a strong correlation was found between TBP measured at toe 1 and 2, respectively (r = 0·99, P<0·001) was found. TBP measured with pole‐pox method were significantly correlated with measurements made by the ordinary cuff technique (r = 0·75, P<0·001).

Conclusions:  The use of TBP and ABP indices instead of absolute BP does not improve the reproducibility but may improve the sensitivity with respect to detection of LEAD, especially in patients with diabetes. The pole‐pox method may be used as an alternative screening method in patients with diabetes and LEAD.
Effects of ventilation on cardiac output determined by inert gas rebreathing
Authors: Damgaard Morten , Norsk Peter
Published: May 2005

One of the most important methodological problems of the foreign gas rebreathing technique is that outcome of the measurements depends on procedural variables such as rebreathing frequency (RF), rebreathing bag volume (Vreb), lung volume at start of rebreathing and intervals between measurements. Therefore, in 10 healthy males we investigated the effects of changes in ventilation pattern on cardiac output (CO) estimated by an N2O‐rebreathing technique. Reducing the rebreathing volume (Vreb) from 1·5 to 1·0 l diminished CO by 0·5 ± 0·2 l min−1, whereas an increase in Vreb from 1·5 to 2·5 l had no effects. CO was 1·0 ± 0·2 l min−1 higher when, rebreathing was performed after a forced expiration than following a normal tidal expiration. Serial determinations of CO required a 3‐min interval between the measurements to avoid effects of recirculation of N2O. Changing RF from 15 to 30 breaths min−1 or adding serial dead space by up to 600 ml did not affect the determination of CO. In conclusion, the rebreathing procedure for determination of CO at rest should be performed following a normal tidal expiration with a rebreathing bag volume of between 1·5 and 2·5 l and with manoeuvres separated by at least 3–5 min. Variations in RF within the physiological range from 15 to 30 breaths min−1 do not affect outcome of the measurements.
Regional blood flow during hyperoxic haemodilution
Authors: Meier Jens , Pape Andreas , Kleen Martin , Hutter Jörg , Kemming Gregor , Habler Oliver
Published: May 2005

Background:  Ventilation with pure oxygen (hyperoxic ventilation, HV) increases arterial oxygen content (CaO2). However HV induces arteriolar constriction and thus potentially affects O2 supply. We therefore investigated the effects of HV on regional blood flow (RBF) and O2 supply of different vital organs during moderate normovolaemic anaemia.

Methods:  Twenty‐two anaesthetized dogs were haemodiluted under normoxia (i.e. FiO2 = 0·21) to a target haemoglobin concentration (Hb) of 7 g dl−1 and were subsequently ventilated with pure O2. RBF was determined by use of the radioactive microspheres method in the myocardium, kidney, skeletal muscle, liver, intestine, stomach, and pancreas at Hb = 7 g dl−1 and after subsequent initiation of HV. RBF in proportion to cardiac output (RBFrelative), the variation coefficient of RBF (VC) and regional O2 supply (rDO2) were calculated.

Results:  Initiation of HV at Hb = 7·0 ± 0·3 g dl−1 reduced cardiac index (−17%) as well as RBF within the myocardium (−21%), pancreas (−25%), and skeletal muscle (−25%), whereas renal, hepatic, and intestinal RBF remained unchanged. Consequently RBFrelative of the latter organs increased. Heterogeneity of RBF was marginally affected by HV.

Conclusion:  The initiation of HV during moderate normovolaemic anaemia (Hb =7 g dl−1) was accompanied by RBF redistribution with preference for renal, hepatic and intestinal O2 supply. Cardiac, pancreatic and muscular O2 supply decreased, however without any critical restriction of organ function.
A short period of apnoea causes a marked increase in coronary flow velocity: a transthoracic pulsed wave Doppler study
Authors: Gan Li‐ming , Hägg Ulrika , Wandt Birger
Published: May 2005

Coronary artery flow velocity during a short period of apnoea was investigated by transthoracic Doppler recording in 10 healthy men, aged 24–52. During breath holding for 29 ± 6 s the oxygen saturation in the finger, measured by pulse oxymetry, decreased from 97·5 ± 0·8 to 90·0 ± 3·2% (P<0·001). The maximal coronary blood flow velocity in the left anterior descending artery increased by 62% from 0·26 ± 0·09 to 0·42 ± 0·10 m s−1 and the mean diastolic flow velocity by 47% from 0·19 ± 0·04 to 0·28 ± 0·08 m s−1 (P<0·001). In most subjects the increase of velocity started already after a few seconds of apnoea. Besides theoretical implications the results show that it is very important to be aware of the higher velocity during apnoea in order to avoid misinterpretation when using breath holding during magnetic resonance imaging or Doppler recording of coronary flow.
Effects of lung volume reduction surgery on distribution of ventilation and perfusion
Authors: Moonen Michaela , Xu Jiahua , Johansson Åke , Thylén Anders , Bake Björn
Published: May 2005

Lung volume reduction surgery (LVRS) results in functional improvements in most patients. The mechanisms behind the improvements are not clear. We hypothesized that reduced inequalities in ventilation to perfusion ratio (V/Q) may be a contributing explanation. Nine patients who underwent LVRS were investigated by ventilation and perfusion scintigrams before and after surgery. In addition, 8 healthy subjects were investigated once. The relative ventilation, perfusion and V/Q were calculated in 1 × 1 cm lung elements. Normal range of the element count‐rate was determined by the corresponding results in the normal subjects. Results of this small study show a significant effect of LVRS on V/Q, with reduction of shunt‐like elements. We conclude that the functional improvement after LVRS to some extent may be explained by decreased V/Q inequality.
Left ventricular involvement in arrhythmogenic right ventricular cardiomyopathy – a scintigraphic and echocardiographic study
Authors: Lindström Lena , Nylander Eva , Larsson Hans , Wranne Bengt
Published: May 2005

Background:  Left ventricular involvement in arrhythmogenic right ventricular cardiomyopathy (ARVC) is a common finding in autopsy studies. In clinical studies using myocardial scintigraphy, MRI and echocardiography, contradictory results have been reported. In this study, we therefore investigated a group of 15 patients with ARVC using thallium‐201 (Tl) single‐photon emission tomography (SPECT) and echocardiography including assessment of mitral annular motion with M‐mode and pulsed tissue Doppler.

Methods:  Exercise and rest Tl‐201 SPECT were performed in 15 patients with ARVC. The time from diagnosis of the disease varied from less than 1–16 years. All patients fulfilled the established diagnostic criteria for ARVC. An echocardiographic examination, including assessment of left and right ventricular motion and measurements of the mitral annulus motion with M‐mode and pulsed tissue Doppler was performed in the patients and in 25 normal subjects.

Results:  Tl‐201 uptake defects in the left ventricular myocardium were present in all except one patient (93%). The uptake defects were predominantly located to the anteroseptal and basal posterior segments. Wall motion abnormalities were seen in the same segments, and in addition to this, in the septal area. In line with this, the total amplitude and the peak systolic velocity of mitral annular motion at the septal point were significantly decreased in the patients compared with the control group.

Conclusions:  Our data show that left ventricular involvement is common in ARVC. Tl‐201 SPECT and echocardiographic abnormalities were seen not only in patients with long‐lasting symptoms but also in asymptomatic patients and in those with short duration of symptoms.
Comparison between maximal early diastolic velocity in long‐axis direction obtained by M‐mode echocardiography and by tissue Doppler in the assessment of right ventricular diastolic function
Authors: Emilsson K. , Loiske K. , Öhlin B.
Published: May 2005

Recently the maximal early diastolic velocity in long‐axis direction of the right ventricle (RV) obtained by tissue Doppler imaging (MDV TDI) has been introduced in the assessment of RV diastolic function (RVDF). There are reasons to think that also the maximal early diastolic velocity in long‐axis direction of the RV obtained using M‐mode echocardiography (MDV TAM) could be used to assess RVDF. Therefore, 29 patients were examined with echocardiography and MDV TAM and MDV TDI were measured and compared. A good correlation (r = 0·76, P<0·001) was found between MDV TAM and MDV TDI indicating that MDV TAM might be used in the assessment of RVDF. However, the velocities obtained by MDV TDI (126·7 ± 38·9 mm s−1) were significantly (P<0·001) higher than the velocities obtained by MDV TAM (78·3 ± 27·8 mm s−1) and the agreement between MDV TAM and MDV TDI was rather poor probably mainly due to differences in the measuring technique. This means that reference values cannot be used interchangeably between MDV TAM and MDV TDI. If MDV TAM is going to be used in the assessment of RVDF new reference values have to be produced if today's technique and recommendations to measure MDV TAM and MDV TDI are used. However, as most new echocardiographs are equipped with PW‐TDI technology it seems preferable to use this technique and compare obtained values with already established reference values.
APN‐Physician Collaboration in Caring for Women With High‐Risk Pregnancies
Authors: Brooten Dorothy , Youngblut JoAnne , Blais Kathleen , Donahue Deborah , Cruz Ivette , Lightbourne Michelle
Published: May 2005

Purpose

: To examine: (a) frequency and focus of APN‐physician collaborations in a clinical trial in which half of physician prenatal care for women with high‐risk pregnancies was substituted with APN prenatal care delivered in women's homes; and (b) characteristics of women requiring greater numbers of collaborations.

Design and Methods

: Descriptive study with secondary analysis of data from 83 of the original trial's 85 intervention participants followed by APNs prenatally through 8 weeks postpartum. APN practices, recorded in logs, included APN interactions with the women and the physician, and type of APN contact (e.g., home visit, telephone call). Each APN‐physician collaboration was coded for type, timing, and focus.

Findings

: Total number of APN‐physician collaboration contacts was 351, with a mean of 4.5 and a range of 1 to 16 per woman. Focus of collaborations was: status updates (59%), new physical findings (21%), change in treatment (8%), patient concerns (7%) and medication adjustment (5%). No significant differences in numbers of collaborations were found according to age, primary diagnosis, marital status, type of health insurance, race, or income. Women with high school education received more collaborations than did those not completing high school or those with some postsecondary education. Prenatally, women with a first pregnancy required more collaborations than did multipara participants.

Conclusions

: Most APN‐physician collaborative contacts were focused on monitoring women's physical and emotional status and discussing new physical findings. These collaborations were important in the original trial's successful pregnancy and infant outcomes and savings in health care dollars.
A Model of Consequences of Need‐Driven, Dementia‐Compromised Behavior
Authors: Kovach Christine R. , Noonan Patricia E. , Schlidt Andrea Matovina , Wells Thelma
Published: May 2005

Purpose

: To extend the original need‐driven, dementia‐compromised behavior (NDB) model by explaining the consequences of behavioral symptoms for the person with dementia.

Organizing construct and methods

: Literature is reviewed and the consequences of expressing needs through need‐driven, dementia‐compromised behaviors are posited. The consequences of need‐driven, dementia‐compromised behavior (C‐NDB) theory is proposed as a framework to improve understanding of the person with dementia and the consequences of behavioral symptoms and unmet needs.

Findings

: Instead of normative verbal communication, people with significant dementia commonly communicate need via non‐normative behaviors, making it difficult for caregivers to know that the person has a need and the extent of such need. Not meeting needs of people with dementia affects the person with dementia, care factors, and contextual factors. Cascading effects occur in which not meeting the original need results in new needs and behavioral symptoms.

Conclusions

: This framework indicates the consequences of expressing need behaviorally rather than verbally and shows that caregiver actions might moderate the events that lead to many needs being unresolved. Suggestions are made regarding future research questions deduced from the model.
Processes of Mental Health Service Use by Adolescents with Depression
Authors: Draucker Claire Burke
Published: May 2005

Purpose

: To begin development of a substantive theory of the processes of mental health service use by adolescents who are depressed and by their families.

Design

: Grounded theory.

Methods

: Open‐ended interviews were conducted with 52 young adults who were depressed as adolescents, four of their parents, and eight professionals who work with adolescents who are depressed. The constant comparison method was used to analyze the data.

Findings

: Adolescents who are depressed and their families perceived several “treatment pitfalls” associated with formal mental health services: (a) “They'll (mental health clinicians) think I'm crazy,” (b) “They'll tell my business,” and (c) “They won't have a clue.” The adolescents and their families interacted with the mental health care providers by engaging in the psychosocial process of “venturing through the system,” that is, proceeding despite possible dangers and risks by steering clear, holding back, and letting it take hold.

Conclusions

: Mental health service use by adolescents with depression involved complex and fluid interactional processes among the depressed adolescents, their parents or caretakers, and mental health care providers. Strategies are needed to avoid creating the pitfalls that concern adolescents and their families.
Education as a Determinant of Career Retention and Job Satisfaction Among Registered Nurses
Authors: Rambur Betty , McIntosh Barbara , Palumbo Mary Val , Reinier Kyndaron
Published: May 2005

Purpose

: To compare job satisfaction and career retention in two cohorts of RNs, those whose highest degrees were the associate degree (AD) or the bachelor's degree (BS) in nursing.

Design

: Survey.

Methods

: Instruments included a career satisfaction scale and questions based on the ongoing U.S. Health and Retirement Survey. Three‐thousand nurses in the U.S. state of Vermont were surveyed with a resulting response rate of 56.7%. Of these respondents, 878 RNs fit the study criteria.

Findings

: BS RNs started their nursing careers earlier, were employed longer, had held more positions, and in the largest age cohort (age 40–54), were more likely to have been in their current positions at least 10 years. BS RNs scored significantly higher in job satisfaction related to: (a) opportunity for autonomy and growth, (b) job stress and physical demands, and (c) job and organizational security. AD and BS nurses were not significantly different in their satisfaction with supervision; career, continuing education, and promotion opportunities; or pay and benefits.

Conclusions

: These findings indicate support of bachelor's level education for individual and social return on investment, and they show that AD education might have unintended consequences. Implications for the nursing shortage and educational policy are discussed.
Factors Influencing the Use of Registered Nurse Overtime in Hospitals, 1995–2000
Authors: Berney Barbara , Needleman Jack , Kovner Christine
Published: May 2005

Purpose

: To assess nurse overtime in acute care general hospitals and the factors that influence overtime among various hospitals and in the same hospitals from year to year.

Methods

: Staffing data from 1995 to 2000 from 193 acute general hospitals in New York State were used to examine hospital characteristics (size, location, RN unionization, hospital ownership, and teaching status) to determine whether they were associated with nurse overtime.

Results

: The average weekly overtime RNs worked was 4.5% of total hours, varying from almost none to 16.6%. At mean overtime levels, nurses were working less overtime than the mean for manufacturing workers, but, at the extreme, nurses were working more than 6 hours overtime per week. Significant differences were observed in the use of overtime by hospital ownership and by union status. Nurses in government hospitals worked less overtime than did those in nongovernment hospitals. Nurses in unionized hospitals worked slightly more overtime than did nurses in nonunionized hospitals.

Conclusions

: Hospitals varied dramatically in their overtime use. That some categories of hospitals (e.g., government‐owned) used little overtime indicates that hospital management can find substitutes for overtime to meet fluctuating staffing needs. The finding that hospitals with similar characteristics varied greatly in their number of overtime hours also supported this conclusion.
Simulation and optimisation of an industrial process of sub‐critical spheroidization annealing of a 100Cr6 steel
Authors: Mapelli Carlo , Venturini Roberto , Boniardi Marco
Published: May 2005

The application of the correct industrial thermal pattern for the spheroidization annealing process of steel needs a precise control of the temperature evolution in the furnace environment and in the mass of the treated steel, which was formerly wiredrawn. The aim is to design a thermal evolution that promotes a complete annealed globular structure, the absence of the decarburation and of an excessive grain growth on the surface of the treated material. An experimental procedure that allows building of a reliable simulation model of the heating process, has been based on a precise monitoring of the thermal evolution of the furnace environment and on the microstructural characterisation of the treated steel. The thermal pattern estimated by the simulation model has permitted designing of an optimised industrial thermal cycle to reach a high‐quality standard of the production.
The course of anticoagulation after extracorporeal photochemotherapy
Authors: Ivancic E. , Knobler R. , Quehenberger P. , Hönigsmann H. , Trautinger F.
Published: May 2005

During extracorporeal photochemotherapy (ECP) heparin is added to the extracorporeal circulation to avoid clotting. It has not been investigated whether and to what extend this procedure influences coagulation in patients after ECP. In this study activated partial thrombaplastin time (aPTT) and anti‐factor Xa were monitored for up to 4 h after ECP in 10 patients. We found that anticoagulation followed the typical course of intravenously applied heparin: immediately after reinfusion anti‐Xa was high (>1 IU/ml) and aPTT was prolonged to more than 180 s followed by a rapid decline and reaching normal values within 3–4 h in all patients. We conclude that anticoagulation and increased risk of bleeding after ECP is confined to a short period immediately following treatment. Physicians using ECP should be aware of the course of anticoagulation associated with this treatment.
Exacerbation of presumed chronic actinic dermatitis by cockpit visible light in an airline pilot with atopic eczema
Authors: Yones S. S. , Palmer R. A. , Hextall J. M. , Hawk J. L. M.
Published: May 2005

Chronic actinic dermatitis (CAD) is a persistent ultraviolet radiation‐ or visible light‐induced eczema of predominantly the exposed areas of usually elderly people. We now present the case of a young pilot with atopic eczema who developed CAD, regularly exacerbated by exposure to visible light through his aircraft cockpit window.
Phototherapy and photochemotherapy of sclerosing skin diseases
Authors: Brenner Michaela , Herzinger Thomas , Berking Carola , Plewig Gerd , Degitz Klaus
Published: May 2005

The treatment of sclerosing skin diseases [systemic sclerosis, localized scleroderma, lichen sclerosus et atrophicus, sclerodermoid graft‐vs.‐host disease, scleredema adultorum (Buschke), scleromyxedema and necrobiosis lipoidica] is difficult and remains a great challenge. Numerous treatments, some with potentially hazardous side effects, are currently used with only limited success. The introduction of phototherapy and photochemotherapy for sclerosing skin diseases has considerably enriched the therapeutic panel and proven useful in a number of sclerosing skin diseases especially in localized scleroderma. Two phototherapeutic modalitites are used for the treatment of sclerosing skin diseases, long‐wave ultraviolet A and psoralen plus ultraviolet A (PUVA). This article reviews current knowledge about the application of phototherapy and photochemotherapy to various sclerosing skin disorders.
A study of Q‐switched Nd:YAG laser irradiation and paracrine function in human skin cells
Authors: Burd Andrew , Zhu Ningwen , Poon Vincent K. M.
Published: May 2005

Background and objectives: This preliminary laboratory‐based study looks at the paracrine release from human skin cells subject to sublethal Q‐switched Nd:YAG 532 nm laser irradiation.

Study design/Materials and methods: Human dermal fibroblast and keratinocyte cultures were exposed to sublethal energy using the Nd:YAG 532 nm laser. Altered gene expression was then screened using RT‐PCR for a range of paracrine factors known to affect melanogenesis, basic fibroblast growth factor (b‐FGF), hepatocyte growth factor (HGF), stem cell factor (SCF), melanocyte stimulating hormone (MSH), endothelin‐1 (ET‐1), interleukin‐6 (IL‐6), tumor necrosis factor‐α (TNF‐α) and protease‐activated receptor‐2 (PAR‐2). Enzyme‐linked immunosorbent assay (ELISA) was used to confirm protein production. Conditioned medium was used to assess altered melanogenesis in a melanoma cell line.

Results: Fibroblasts exposed to sublethal radiation showed upregulation of b‐FGF, HGF and SCF. This contrasts with keratinocytes which showed upregulation of IL‐6. Elevated protein levels of b‐FGF and SCF were confirmed by ELISA assay. Conditioned fibroblast medium was shown to stimulate melanogenesis in a melanoma cell line.

Conclusions: This preliminary laboratory study reports, for the first time, specific gene upregulation using the Q‐switched Nd:YAG 532 nm laser.
Evaluation of vaseline oil applied prior to UVB TL01 phototherapy in the treatment of psoriasis
Authors: Penven K. , Leroy D. , Verneuil L. , Faguer K. , Dompmartin A.
Published: May 2005

Background: Use of emollient prior to phototherapy could enhance UV transmission through psoriasis plaques on the condition that the emollient is not photoprotective. Emollient pretreatment with narrow‐band phototherapy (313 nm) has not been studied extensively. We conducted a study to assess if vaseline oil prior to UVB TL01, in chronic psoriasis plaques could accelerate psoriasis clearance.

Methods: Fifteen patients with chronic psoriasis plaques were enrolled in a prospective, single‐blind, controlled study. For each patient, one to three symmetrical pairs of plaque were selected and scored initially and after every six exposures.

Results: On the vaseline oil pretreated side, significantly more plaques were cleared, especially in severe psoriasis. Scaling and infiltration were significantly improved. Application of vaseline oil was more interesting in thick and scaly psoriasis probably because the oil penetrates the intercellular space allowing an optical matching effect which increases the UV transmission.

Conclusion: We strongly recommend vaseline oil pretreatment with UVB TL01 phototherapy in psoriasis, especially in severe psoriasis.